The Rusting Process Essay Example | Topics and Well Written Essays - 2000 words

The Rusting Process - Essay Example A closer look at the website of the company would suggest that its business is divided into three different segments. Its consumer segment provides services such as Broadband, digital TV, home phones etc. consumers are also offered some bundled packages like Broadband and TV together. Its Small and Medium Business segment provide broadband facilities to the businesses along with offering other services such as web hosting & ecommerce as well as management of email and internet facilities at its clients. Its large business and public sector segment offer services such as networked IT services, Industry expertise, in-house facilities and other high end services. The following section of the report will present an analysis of the forecasted financial performance of the company as on 31.03.2009. For detailed working of the facts and figures, please see the attached appendix. 1) Sales growth will be taken from the historical trends of the sales growth in last five years. Though the GDP growth Of UK can be considered as an alternative but since company works in more than one country therefore its historical sales growth will be taken while projecting the sales growth as on 31.03.2009. 2) All the cost items will be forecasted by taking their relationship with the sales i.e. as % of sales. 3) No dividends will be paid 4) No fresh injection of equity except increase in it through retained earnings. 5) Taxation is not being computed as per the laws enforced but as a % of the total revenue of the company. Forecasted Financial Performance Core Ratios In order to assess the core ratios of the firm, we have taken four most important ratios into account. First ratio is return on sales or net profit margin suggesting that the historical performance of the company is somewhat mixed and consistent and the predicted results have also suggested that the company has been able to maintain its profitability with upward trends. This also can be attributed to the decreased interest expenses. Asset turnover is the second key ratio which suggests how the assets of the company are managed in generating the value for the firm. The assets turn over of the firm consistently remained under 1. It may indicate that the firm has assets which are relatively new and are recorded at high cost. Since the company deals with providing services which require high investment into technology which is changing therefore high asset values of the firm may be justified. Asset leverage suggests the use of equity and debt in acquiring the assets of the company. The predicted figure suggests that the asset leverage has continuously declined due to the injection of fresh equity into the business as well as increased profitability. Asset leverage also indicates towards the fact that the management may have more inclination towards the use of the debt into acquiring the assets. The use of debt also suggests that the firm may utilize

Any student caught cheating on an examination should be automatically Essay - 1

Any student caught cheating on an examination should be automatically dismissed from college - Essay Example Students should be made to understand why cheating is wrong instead of just telling them it is wrong. This is done to prepare students for life challenges and make them understand the steps needed to succeed in life the honest way. This involves dealing with cheating cases in an intelligent way which supports and promotes honesty in the student. Letting students get away with cheating or imposing severe and destructive punishments does not favor them. Instead, Gardner et al., (2008) proposes that different punishments such as failing the students and calling their parents to talk to them may offer the best solution. The punishment issued should not affect the student’s future and thus requires the lecturers to be vigilant so that fairness can be achieved. Lecturers need to take a holistic view of exam cheating specifically in the current times where the students are brought up in a decadent society. Colleges need to devise better ways of solving students’ problems that prompt them to result in cheating during examinations. Automatic dismissal is too harsh and painful both for the students who are caught cheating and for the overall community. Cases of examination cheating have tremendously increased in colleges today which renders automatic dismissal inadequate solution. Students who cheat are prompted by the desire for higher grades and the fear of failure. Students cheat for various reasons some of which are psychological. As such, the foundation of the solution lies in understanding the core reason of cheating. Cheating has many forms ranging from copying from a friend’s works, using phones, the internet, plagiarism, sneaking books and other written materials and passing off as another person into the exam room. The severity of the punishment deserving of students cheating in an examination should be moderated depending on the gravity of their actions as opposed to dismissing all examination cheaters alike. College life requires hard work and

Crystalline Modifications and Solubility of Prepared Crystal

Crystalline Modifications and Solubility of Prepared Crystal LITERATURE REVIEW Tejal Prajapati et.al., (2010) Investigated different crystal forms of carbamazepine was prepared from various solvents. Crystalline modifications and the solubility of prepared crystals and immediate release tablet dissolution rate profile of carbamazepine studied by using in vitro dissolution studies. These obtained crystal forms of carbamazepine and pure drug was characterized by SEM, FTIR, PXRD and DSC. Highest solubility profile shown by Crystals obtained from ethanol at room temperature and it gave better in vitro dissolution drug release profile than all other forms. Nokhodchi et.al., (2010) Developed ibuprofen crystal forms by using solvent change crystallization technique. Ibuprofen was dissolved in ethanol, and then that solution was crystallized with water in the presence or absence of different types of hydrophilic additives or polymers (like PEG 6000, 8000, Brij 98P and PVA 22000) and using with different concentration ratios. Physico-mechanical properties of Ibuprofen crystals were studied by density, flow property, tensile strength and dissolution behaviour and characterized by SEM, DSC and FT-IR. Ibuprofen crystals crystallized with presence of PEG 6000, 8000 and PVA shown reliable increase in the tensile strengths results of the directly compressed tablets. Talluri chandrashekar et.al., (2010) Developed four different types of Chlorzoxazone polymorphs (Form I, Form II, Form III and Form IV) by using different types of solvents. The obtained polymorphs were characterized by using Optical Microscopy, DSC, XRD and IR spectroscopic methods. From the studies it was revealed that the Form I, Form II shown higher solubility rate profile than Form III, Form IV and pure drug. Rajesh A. Keraliya et.al., (2010) Investigated 14 pure good solvents were selected for the crystallization of tolbutamide. Crystals were obtained in only 10 solvents out of the all 14 solvents. These developed Crystal forms were characterized by using differential scanning calorimetry, optical microscopy, and in vitro dissolution study. Differential scanning calorimetry study shown all types of crystals were determined as isomorphic. Crystal forms of tolbutamide gave different dissolution rates. Cheng-Hung Hsu et.al., (2010) Studied transformation of different gabapentin polymorphs forms. Four types of gabapentin polymorphs were developed and these are characterized by using DSC, TGA, FTIR Microspectroscopy and X-ray powder diffractometry. A one-step novel hot-stage FTIR microspectroscopy was successfully applied to progressive processes of polymorphic forms transformation of prepared crystals. Gen Hasegawa et.al., (2009) Prepared different types of tolbutamide polymorphs and thermodynamic stability was characterized by using calorimetry and spectroscopic analysis. Forms I-III The heat of solutions (à ¢Ã‹â€ Ã¢â‚¬  H) measurements were observed in solvent of dimethylsulfoxide between 298.2K and 319.2 K. Solubility data also observed and then confirmed the change in à ¢Ã‹â€ Ã¢â‚¬  H of Form I around 308.2 K. XRD, DSC measurements of Form I characterized as a polymorphic transformation was observed at 311K. The crystal forms structure of the Form I was determined by using PXRD pattern, and solid-state NMR spectrum confirmed the transformations occurred in the prepared crystal form structure of tolbutamide Form I. Roya Talari et.al., (2009) Investigated Gliclazide was recrystallized and developed polymorphs with 12 different types stabilizers and each stabilizer gives effect on micromeritic behaviors, microcrystals morphology, dissolution rate profile and recrystallized gliclazide solid state were studied. Recrystallized samples showed faster dissolution rate than gliclazide pure drug and the fastest dissolution rate profile was observed the samples recrystallized with PEG 1500 stabilizer. XRPD and DSC results confirmed that crystallization of gliclazide forms with stabilizers reduced the crystallinity of the samples. Renu Chadha et.al., (2009) Prepared five different crystal forms of methotrexate and Characterized by using XRPD and DSC. Desolvation endotherm was determined by the DSC. In I, II, IV and V crystal forms mass losses were observed in TGA and shown these forms are acetonitrile solvate hydrate, dimethylformamide solvate and trihydrate (I, V, II and IV) respectively. Desolvation peak was not observed in Prepared from methanol crystal form (form III) and that indicates the absence of solvent of crystallization. This form III was shown partially crystalline pattern by its XRPD. All prepared forms the dissolution and solubility rate profiles were correlated with enthalpy of solution and subsequently to the crystallinity of all four forms of methotrexate; and crystal form III shown highest dissolution rate than other prepared forms. Mange Ram Yadav et.al., (2008) Developed five different types of crystal forms of Pefloxacin by using with different solvents of varying polarities, and the dissolution kinetics of five polymorphs was observed. That reveled these polymorphs differed in their dissolution rate profiles and all polymorphs shown unusual behavior in highest dissolution rate profile at the end of 15 min after that some what similar dissolution rate. Finally got constant dissolution release values after 4 hrs. Shan-Yang Lin et.al., (2007) Investigated two polymorphic forms A B of famotidine. It describes famotidine polymorphic transition may produce by the grinding or compression process in ground mixtures or compressed compacts in tabletting process time. The synergistic effect of temperature on the grinding or compression process was also investigated. In the ground mixtures, famotidine polymorphic transition was characterized by confocal Raman Microspectroscopy, DSC. Mechanical forces, which are grinding and compression, are having effect on polymorphic transformation of Famotidine. Ilma Nugrahani et.al., (2007) Evaluated amoxicillin trihydrate and potassium solid state interaction. The solid state interaction was characterized by using DSC, XRPD, FTIR and SEM. Different compositions of amoxicillin trihydrate and potassium clavulanate were developed in ten different molar ratios and characterized by DSC to get the thermal profile and a phase diagram of composition. Binary systems thermo profile obtained by DSC analysis that endothermic curves of molar ratios of 1:9-5:5 overlapped at 201 °C. the molar fraction ratio of 5:5 shown the loss of hydrate spectra in amoxicillin trihydrate characterized by FTIR spectrum of binary system. We conclude co-crystal system produced by the strong hydrogen bonding interaction between hydrates of amoxicillin and potassium clavulanate. Cristina Puigjaner et.al., (2007) Investigated new polymorphic forms A, B C of Norfloxacin. These polymorphs forms were characterized by different methods like powder X-ray diffraction, Vibrational spectroscopy (IR and Raman), thermal analysis (DSC and TG), SEM and solid-state NMR spectroscopy. The data show an enantiotropic relationship between A C forms, as well as a monotropic relationship between B C. C.G. Kontoyannis et.al., (2007) Reported Risperidone polymorphic forms of film coated commercial tablets and characterized by using IR spectroscopy, Raman spectroscopy and X-ray powder diffraction. This Risperidone polymorph stability was examined through time and during the manufacturing process. The inability of IR and Raman techniques to identify the presence of polymorph A in the tablets. Form A was proved to be stable during the manufacturing process time and after the storage period of 2 years. Wang Jingkang et.al., (2007) Reported crystal habit of 11ÃŽÂ ±-hydroxy-16ÃŽÂ ±, 17ÃŽÂ ±-epoxyprogesterone (HEP) grown from solution by the effects of solvent and impurity were characterized by using SEM. Long prismatic crystals were formed from crystallization of HEP in pure acetone and N, N-dimethylformamide. Blocky crystals were resulted with pure chloroform by using cooling crystallization method. These HEP crystals were greatly modified from prismatic to octahedral shape. That the change of crystal habit was brought from the modification of crystal structure by DSC and X-ray powder diffraction. Piera Di Martino et.al., (2007) Reported crystal forms of nimesulide prepared by crystallizing from an ethanol solution and dioxane, different from the pure drug nimesulide reference sample, it was characterized by using XRPD, DSC and solid cross polarization-magic angle spinning NMR. Dioxane nimesulide forms are solvate. The polymorphic form prepared by desolvation of dioxane solvate gave positive effect on nimesulide forms tableting properties increasing the both compressibility and tabletability. Joao Canotilho et.al., (2007) Prepared crystalline forms of atenolol from evaporation of an ethanol/water solution. (R, S)-Atenolol crystallizes in the centrosymmetric and S-atenolol crystallizes in a noncentrosymmetric space group C2/c and space group C2 respectively. One symmetry and two symmetry independent molecule in (R, S)-atenolol crystals and molecules in S-atenolol respectively. (R, S)-atenolol shown two different molecular conformations and three different conformations were isolated in S-atenolol.. The molecular conformations characterized by X-ray diffraction method were fully relaxed at the HF/6-31G* level of theory. Reddy et.al., (2005) Investigated a novel crystalline form of cetirizine monohydrochloride was prepared. These prepared crystalline forms of cetirizine monohydrochloride were characterized by using x-ray diffraction pattern, differential scanning calorimetry. Kati Pollanen et.al., (2005) Prepared polymorphic forms of sulfathiazole. These polymorphic forms composition of bulk product samples characterized by diffuse reflectance Fourier transform infrared spectroscopy together with multivariate statistical process control analysis, soft independent modeling of class analogy, orthogonal signal correction preprocessing and partial least squares regression methods. Ali Arslantas et.al., (2005) Investigated L-ascorbic acid polymorphs considered as eight space groups and assuming one molecule in the asymmetric unit. Including with the experimental structure and number of possible crystal structures were found. By removing space-group symmetry constraints, the number of hypothetical crystal structures was reduced. Schmidt et.al., (2005) Reported Benzocaine (BZC), butambene (BTN) and isobutambene (BTI) are ester type basic local anaesthetic agents. These are exist in two polymorphic crystal forms and characterized by thermomicroscopy, DSC, FTIR, FT-Raman-spectroscopy and XRPD. The endothermic transformation of mod. I0 at ambient conditions thermodynamically stable (heat of transition rule). Whereas mod. II and mod.I0 enantiotropic in nature and mod.II is metastable at temperatures. At room temperature the metastable forms show different kinetic stabilities. Vijayavitthal T Mathad et.al., (2005) Prepared six polymorphs of donepezil hydro bromide from different types of solvents, and these polymorphs physical properties are characterized by PXRD, DSC, TGA, IR spectroscopy and Karl Fischer techniques. It reveled one is crystalline hydrate , four are anhydrous polymorphs and one is amorphous form. Arvind k. Bansal et.al., (2004) Studied clopidogrel bisulphate polymorphic form I and form II. Obtained polymorphs were characterized by Thermal (DSC, TGA, HSM), crystallographic (XRD) and spectroscopic (FTIR) methods. Differences in their spectral patterns were successfully utilized for the quantification of forms I and II in powder mixtures. The forms undergo no transformations and exhibit no crystal defect generation when exposed to pressure during the KBr pellet formation. FTIR method was successfully characterized and validated for the quantification of prepared clopidogrel bisulphate polymorph form I in polymorph mixtures. David J. W. Grant et.al., (2004) Reported two polymorphic forms of s Piroxicam. The difference in energy of the two polymorphs, I and II, of Piroxicam arises predominantly from the difference between their lattice energies, rather than between their conformational energies. A loss of polymorphic memory was observed upon cryogrinding, the two polymorphs are leading to differences in their recrystallization behavior between Piroxicam amorphous prepared in polymorphs I and II.di Young-Taek Sohn and Hyun Ok Seo et.al., (2004) Developed four types of crystal forms of ketorolac by recrystallization from various organic solvents under variable conditions. Different types of ketorolac polymorphs and pseudopolymorphs were characterized by XRPD, DSC, and thermogravimetric analysis. All four crystal forms showed different types of dissolution studies in water at 37 ±0.5oC. Form I shown the highest solubility. Polymorphic forms of Form I and Form III shown good physical stability at room temperature for 60 days. After 60 days storage Form IV is converted to Form I and Form II is converted to Form III. Sari Airaksinen et.al., (2004) Investigated two polymorphic forms of theophylline monohydrate. Theophylline monohydrate transforms either stable (form I), or metastable (form Ià ¢Ã‹â€ -) form of anhydrous theophylline during the drying phase of wet granulation method. Amounts of the different theophylline crystalline forms remaining in the form of dried granules were characterized by using XRPD and near-infrared spectroscopy. It conclude the Metastable anhydrous theophylline was the major form that was produced at drying temperatures of 40-50 à ¢- ¦C with both MMFD and VT-XRPD drying techniques. Mahua Sarkar et.al., (2008) Developed nevirapine polymorphic forms from different types solvents under various conditions by crystallization. These forms solid-state behavior was characterized by using variety of complementary techniques such as microscopy (optical, polarized, hot stage microscopy), DSC, TGA, FT-IR and powder X-ray diffractometry. Nevirapine forms crystallized from varying polarities and yielded different crystal habits. The recrystallized sample intrinsic dissolution rate of was lower than the commercial sample. Nevirapine Amorphous form shown slightly higher aqueous solubility than commercial sample. Makoto Otsuka Fumie kato et.al., (2003) Investigated indomethacin polymorphic content in mixed pharmaceutical powder and tablets by using rapid chemometrical near-infrared spectroscopy. Polymorphic contents of forms ÃŽÂ ± and ÃŽÂ ³ were obtained from physical mixing of IMC standard polymorphic sample 50% and excipient mixed powder sample consisting of lactose, corn starch, and hydroxypropyl-cellulose 50% in Mixed powder samples. 6 kinds of standard materials with various polymorphic contents were characterized by using X-ray powder diffraction profiles and NIR spectra. more accurate quantitative analysis of polymorphic content provided by NIR spectroscopy in pharmaceutical mixed powder and tablets. Sabiruddin Mirza et.al., (2003) Developed crystal forms erythromycin with various organic solvents, (acetone, methylethylketone, ethanol, and isopropanol) both in the presence and in the absence of water on the crystallization. It was observed that pure organic solvent or water-organic 1:9 or 1:1 solvent mixtures are solvate. However, the recrystallization of erythromycin from 2:1 water-organic solvent mixture gives crystal hydrate form. that the loss of volatiles by all the solvated crystals is nonstoichiometric showed by Thermo-gravimetric analysis. The solvates with the organic solvents desolvation behavior of characterized by variable-temperature x-ray powder diffraction. R. Fausto et.al., (2003) an amorphous state produced by Fast cooling rates that, on more heating, that crystallizes into metastable polymorph. At higher temperatures, this metastable crystalline form converts into the stable crystal form. Cooling rates is intermediate produce 3AP crystallizes as the metastable polymorph, the solid l solid transition occurring on heating and this form into the stable polymorph. cooling rate is Slower enable formation of the stable crystal on cooling. The two crystalline polymorphs were characterized by using powder X-ray diffraction and Raman spectroscopy. It concluded that different types of conformations are assumed by the individual molecules of 3AP in two crystalline forms. Amy J. Harshaw et.al.,(2003) Examined four polymorphic crystalline forms sulfathiazole exist in solvents used n-propanol, acetone/chloroform, water. These forms were characterized by using differential thermal calorimetry and solubility studies and these are recrystallizing under the various conditions as a function of temperature. The best polymorph formation was found in the hot water sample. Adam J. Matzger et.al., (2002) Developed new polymorph crystal structure of nabumetone. Energy differences gives weak forces, these weak forces play such an important role in the kinetic and thermodynamic stabilization of nabumetone polymorphs Judith Maria Rollinger et.al., (2002) Prepared three crystal forms of torasemide from various types of organic solvents. These forms Physicochemical properties were characterized by using thermoanalysis (hot-stage microscopy, differential scanning calorimetry, thermogravimetry), Fourier transform infra-red and Raman spectroscopy, and X-ray powder diffractometry. The hygroscopicity, relative stability, true density, and heat of solutions were determined. The dissolution behaviour of mod. I and II was investigated as a function of pH, temperature, and in addition to surfactants. S. Agatonovic-Kustrin et.al., (2001) Developed two polymorphic forms 1 and 2 of ranitidine HCl. This polymorphic purity of crystalline ranitidine HCl characterized by using solid-state techniques, diffuse reflectance FT-IR and XRPD were combined. The ranitidine HCl polymorphs and quantify the composition of binary mixtures of the two polymorphs clearly distinguished by DRIFTS combined with XRPD Successfully. A.R. Rajabi-Siahboomi et.al., (2001) Investigated crystal form of Ibuprofen was obtained from various solvents like methanol, ethanol, isopropanol, and hexane. The crystal forms of ibuprofen were crystallized from methanol and ethanol gave polyhedral crystal habit, while hexane was given needlelike, isopropanol was shown elongated crystals. XPD and DSC studies results are these samples were structurally similar; the results shown that crystal habit modification of prepared crystals have a great influence on the mechanical properties (compressibility, flow rate, and bulk density) of obtained ibuprofen crystals. John Bauer et.al., (2001) Prepared Ritonavir polymorphs from various solvents characterized by using solid state spectroscopy and microscopy techniques, solid state NMR, NIR, PXRD and Single crystal X-ray. A strong hydrogen bonding network gives an unusual conformation for form II. Ritonavir was found to be exhibit two unique crystal lattices conformational polymorphism. Which are having different solubility properties. Although the polymorph (form II) belongs to the cis confirmations it is a more stable packing arrangement, nucleation. Changquan Sun and David J. W. Grant et.al., (2001) Reported bulk powders of sulfamerazine polymorph I and two different particle size of polymorph II , II(A) and II(B) were crystallized. The powders were compressed to form tablets whose porosity and tensile strength were measured and then analysed. The tabletability, follows this order, I >> II(A) > II(B) and the compressibility, follows the order, I Malamataris et.al., (2000) Prepared crystalline form of glibenclamide, with higher melting point (218 °C) and having lower solubility in simulated gastric and intestinal fluids, these are changed by transitional phases by melting, cooling and reheating. The new form of glibenclamide was obtained from the glassy state, by applying sublimation temperature at 130-160 °C. New form of glibenclamide was characterized by DSC, FT-IR, SEM, hot-stage microscopy, PXRD and solubility studies. Yumiko Kobayashi et.al., (2000) Developed polymorphs of carbamazepine and studied pseudopolymorphs (form I, form III and dihydrate) dissolution behaviors and bioavailability. The solubilities of both anhydrates (form I and form III), evaluated from the initial dissolution rate profile of each anhydrates were 1.5-1.6 times dihydrate. Gamberini et.al., (2000) Prepared three different carbamazepine polymorphic forms. Polymorphism and pseudopolymorphism can give affect on bioavailability and effective clinical use. These prepared polymorphs characterized by FT-IR spectroscopy, XRPD, DSC, Hot Stage FT-IR thermomicroscopy. The obtained three different polymorphic forms are anhydrous carbamazepine: Form III, the commercial one, Form I. Young-Taek Sohn et.al., (2000) Recognized physicochemical properties of drugs affected by the type of crystalline form of the drugs. Clarithromycin gave three polymorphic crystalline forms. New method involved to simple recrystallization of clarithromycin in different solvents like hexane, heptane or ethers, isopropyl ether. These polymorphs are compared by using DSC, XRPD with form II crystal prepared by conventional method. It indicated that improvement in the purity of the Clarithromycin polymorph form II crystal. Robert E. Dinnebier et.al., (2000) Detected three crystalline modifications (A, B, and C) and these crystal structures were characterized by using single-crystal X-ray diffraction (pseudopolymorph C) and the method of simulated annealing from high-resolution X-ray powder diffraction data and IR. Obtained crystal packing and the molecular conformation of telmisartan Demonstrating the medium-sized (MW  » 500) pharmaceutical compounds can now be solved quickly and routinely by using high-resolution X-ray powder diffraction data. MartÄ ±nez-Oharriz et.al., (1999) Investigated the physico-chemical characteristics of diflunisal-PEG 4000 solid dispersions prepared by melting, solvent and melting-solvent methods. Solvents are chloroform, methanol and ethanol-water. The drug present in different polymorphic forms. The characterization of solid dispersions was performed by X-ray powder diffraction. In solid systems obtained by the solvent and melting solvent methods and the drug solidifies in form III in ethanol / water and methanol, while polymorph IV crystallized in chloroform. In conclusion it reveled that changes in diflunisal polymorphic forms occurred during the formation of solid dispersion. Polymorphic form of drug determined by drug polymer ratio and method of preparation. Shivakumar et.al., (1999) Prepared different types of crystal and paracetmol crystals and the effect of solvents on the crystallization were characterized by using FT-IR, DSC and Powder XRD patterns. The results indicate that crystals prepared from different types of solvents exhibited different physicochemical properties. Desired physicochemical properties of crystals may be obtained by selecting the different types solvents by depending on the solubility profile of drug. Y.E. Hammouda et.al., (1999) Reported sulphadiazine (SD) a suspension of the drug in a preselected solvent (5% aqueous ammonia solution) was stirred under controlled conditions. The solvent was subsequently removed and the material dried. The effect of experimental variables such as stirring speed and time, powder/ solvent ratio and inclusion of additives (Tween 80, sodium chloride and PVP) on the properties of solvent treated SD was assessed. Data obtained were compared with those for SD recrystallized under identical conditions. Solvent treatment of SD in the absence of additives resulted in a limited change in crystal morphology as indicated by SEM. This was associated with improved flowability and a limited reduction in dissolution rate relative to untreated SD. On the other hand, recrystallized SD exhibited superior flowability but a considerably low dissolution rate. Solvent treatment of SD in the presence of 2% PVP produced a microgranular directly compressible material. Monica Bartolomei et.al., (1999) Prepared two forms of propranolol HCl and investigated the crystallization conditions and the physicochemical properties of the two polymorphs I and I. these are characterized by using FTIR spectroscopy, PXRD, thermal analysis, solubility and dissolution studies. Their stability test was followed at room temperature over a period of 1 year time and using under different conditions of temperature, grinding and compression to verify the capacity to solid-solid transition and to study the existence range of the two forms. These obtained results shown that form I was having less thermodynamically stable and more soluble and dissolved faster than crystalline form II. Ranendra N. Saha, K.Venugopal, New, et. al., (2005) Developed for the estimation of Gatifloxacin in bulk and pharmaceutical formulations UV-spectrophotometric methods were used. Gatifloxacin was estimated at 286 nm in 100 mM phosphate buffer (pH 7.4) and 292 nm in 100 mM hydrochloric acid (pH 1.2). Linearity range was found to be 1-18 ÃŽÂ ¼g ml-1, in the phosphate buffer (pH 7.4) and 1-14 ÃŽÂ ¼g ml-1 in hydrochloric acid medium (pH 1.2). These methods were tested and validated for various parameters according to ICH guidelines and USP. These methods were successfully estimated for the determination of Gatifloxacin in pharmaceutical formulations. Carolina B. Romanuk et.al., Reported two different types of polymorphic forms of new ciprofloxacin saccharinate. These two poymorphs were characterized and determine both polymorphic forms we used solid state techniques: powder X-ray diffraction, single crystal X-ray diffraction, Infrared and Solid State NMR. V. Agafonov et.al., (1991) Developed single crystals of two polymorphic and four solvated crystalline forms of spironolactone from different types solvents. All crystal forms except for the one obtained from methanol, morphology, symmetry, and crystallographic parameters were determined. The stability of crystals and transformation of each type of crystal were characterized by using DSC, TGA, and X-ray diffraction analysis. It conclude molecules of spironolactone in the three different types of lattices. Masato OHTA et.al., (1999) Investigated, heat of crystallization and heat of solution cefditoren pivoxil of different crystallinity were characterized by DSC and isothermal microcalorimetry, respectively. Cefditoren pivoxil heat of crystallization and heat of solution shown good linear correlation with the degree of crystallinity determined by Rulands method by using powder X-ray diffractogram. The crystallinity changes of amorphous cefditoren pivoxil by adsorption of alcohol vapor could be evaluated for small quantity of sample by using of heat of crystallization. microcalorimetry was used to found prediction of dissolution behavior. El-Sayed et.al., (1983) Developed four polymorphic forms of spironolactone. These crystal forms characterized by using melting point and aqueous solubility, IR, DTA, PXRD and powder dissolution. Prepared Crystals with ethyl acetate showed the lowest melting range and having highest dissolution, while prepared crystal from acetonitrile shown the highest melting range and shown low dissolution rate. Infrared spectra were not useful in clearly distinguishing between the different forms. DTA curves indicated that were different from the original form of the drug. X-ray patterns were different in intensities of radiation absorption and finally it confirming the presence of four different types of crystalline forms of spironolactone. Robert E. Dinnebier et.al., (2000) Investigated Three crystalline forms A, B, and C of telmisartan and their polymorphs crystal structures characterized by single-crystal X-ray diffraction. Explanation of the crystal packing and the molecular conformation of medium-sized (MW à ¢Ã¢â‚¬ °Ã‹â€  500) pharmaceutical ingredients can now determined by high-resolution X-ray powder diffraction data. J.M. Delgado et.al., (2007) Prepared several polymorphs of oxytetracycline hydrochloride under different conditions by crystallization: different conditions are slow evaporation, rapid crystallization, and vapour diffusion in different types of solvents. The solvents are used included like water, ethanol, methanol, ether, ethyl acetate, toluene, dichloromethane and dioxane. The obtained different polymorphs products were characterized by X-Ray Powder Diffraction, NMR, FT-IR, and Thermal Analysis (TGA and DSC). Biserka Cetina-Cizmek et.al., (2003) Developed piroxicam benzoate Solid-state properties and Investigated. piroxicam benzoate Samples were prepared by recrystallization from different types organic solvents (toluene, ethanol, methanol, ethyl acetate and acetone). Prepared samples were characterized by using FTIR, DSC, TGA, SEM and XRPD. DSC, TGA and XRPD. These are confirmed that piroxicam benzoate crystallized in two types of pseudopolymorphic forms A and B. Pseudopolymorphic form A was obtained by recrystallization in ethanol and methanol by slow cooling at ambient temperature and by rapid cooling in an ice-cold bath. Pseudopolymorphic form B was obtained by recrystallization from toluene by slow cooling at room temperature and also from toluene by rapid cooling in an ice cold bath. Arvind K. Bansal et.al., (2003) Studied generation and characterization of various solid-state forms of celecoxib, The Celecoxib drug was subjected to polymorphic screen using various types of organic solvents to exhausts the possibility of existence of different solid forms. 1:1 stoichiometric ratio of N,N-Dimethyl acetamide (DMA) and N,N-dimethyl formamide (DMF) gave solvates. Quench cooling of the melt resulted in amorphous form of the drug. All these solid-state forms were analszed by thermoanalytical (DSC, TGA, HSM), crystallographic (XRD), microscopic (polarized, SEM), spectroscopic (FTIR), and elemental analysis techniques. Morphology Influences on flow behavior of different solid-state forms was also investigated. Marcelo Antonio Oliveira et.al., (2010) Reported that the TGA and DSC are very useful for characterizing the drug and excipients stability. Verapamil hydrochloride shown thermal stability up to 180  °C and melts at 146  °C. Evaluated the Verapamil hydrochloride drug is compatible with all other excipients. The drug shown degradation when exposed to oxidizing conditions, that the degradation product resulting is 3,4-dimethoxybenzoic acid derived from the alkyl side chain oxidation. Alok Tripathi et.al., (2010) Developed ten crystalline polymorphic forms along with an amorphous form of Rabeprazole sodium. Polymorphism is gives solid physical properties they are influence on biological activity of drug, physiochemical properties of drug or substance industrial manufacturing method. Researchers attracted towards new polymorphic form of Rabeprazole sodium. Some polymorphic correlation parameters such as type of the solvent, , sequence of addition, temperature, volume of the solvent, rate of the agitation, pH of reaction mixture etc. showing effect on the polymorphism. Kalinkova et.al., (1996) Investigated polymorphism of azlocillin sodium. Results of infrared spectroscopy, thermal analysis (combined thermogravimetry and differential analysis) and scanning electron microscopy confirmed recrystallization of lyophilized azlocillin sodium from simple solvent acetonitrile causes polymorphic transformation. New polymorph obtained by crystalline form. C. Rodriguez-espinosa et.al., (1994) Investigated polymorphism crystal forms of I, II, and III forms and new crystal form (form IV ) of diflunisal and these forms characterized by using powder X-ray diffractometry, DSC, hot-stage microscopy, IR spectroscopy, and dissolution studies. The mutual transition behavior of the prepared polymorphs was determined and the melting points and melting enthalpies were charac

Johan Sebastian Bach Essay -- Biography Biographies essays research pa

  Ã‚  Ã‚  Ã‚  Ã‚  On March 21, 1685, Johan Sebastian Bach was born in Eisenach, Germany. His parents’ names were Johan Ambrosias Bach and Elizabeth Lammerhirt Bach. His Family earned its living as musicians. His mom died when Bach was 9 then his dad died the next year so he moved to live with his oldest brother in Ohrdruf. In Ohrdruf Bach Learned Latin and sung as a soprano in the school choir. His brother didn’t have enough money so Bach moved to Luneburg in March of 1700. Bach could go to school for free because he sang in the choir. (Geringer 433, www.let.rug.nl ) Bach left Luneburg in March of 1702 when he was 18, to go to Arnstadt to get his first real job. His job was to be the organist of the Neue Kirche Church. Bach got a four-week vacation from playing at the church to go to Lubeck and listen to the music of Dietrich Buxtehude. He walked 200 miles to get there, and then instead of staying for the four weeks the church had planed, he stayed for four months. (www.let.rug.nl) Bach got a different job as an organist in Muhlhausen at St. Blasius Church in 1707. That year his uncle died and Bach inherited some money. That gave Bach enough money to marry Maria Barbara, his second cousin. They got married in April of 1707. One year later in 1708 Wilhelm Ernst hired Bach as an organist and as a member of the orchestra so Bach and Maria moved to Weimar. Bach’s salary was double what he got paid at his last job. (Geringer 433, Lloyd 30 www.let.rug.nl) Bach and Maria were financially st...

Disability Discrimination Law

In the recent news about Disability Discrimination Law, a particular employee named Kevin Tobin achieved justice after almost a decade of his case (Mulvany, n. p. ). Tobin was employed at Liberty Mutual and had been good in carrying out his tasks (Mulvany, n. p. ). However, he was suffering from bipolar disorder. On Tonbin’s part, he exerted effort to compensate his lost hours of work. But then, his employer still perceived him as high maintenance (Mulvany, n. p. ). Eventually, he was fired. Just recently, the CA affirmed the reinstatement of $1. 3 million to Tobin. The article proves that discrimination in workplace still exists.This is brought by conflicting interest between the state, employee, and employer. As to the state, it enacts laws to protect the general welfare, especially the disabled persons. On one hand, the disable person exerts effort to disregard his disabilities by showing that he can be normal. On the other hand, the employer protects its interest from prof iting and having disable employees only adds them loses. In this scenario, the law tries to equalize the conflicting interests. On the part of employers, they should not forget their moral responsibility to the society.Helping the disabled person can be part of fulfilling such duty. Besides, among many disabled people, there are always special are where they are capable of doing and even surpassing the expectations of employers. Instead of discriminating, the employers should help in eradicating the gaps that continued to detach people living in one country. Giving chance to disabled people is one. The case of Tobin also proves that the Disability Discrimination Law is being upheld in the country. Furthermore, Tobin’s case brings hope to other disabled people who are still suffering discrimination due to their special qualities.

Art Is Long Life Is Short Essay

Art is a one of the most wonderful things in our life. It is an expression of inner thoughts and beauty in our life. It helps people to understand and feel deeply the all beauty and splendor of our culture. Without the greatest masterpieces of past times we even couldn’t find out the development of our history. For example, the most wonderful treasures are Wonders of the World. Thanks to them we know about the potentials of human creativity, thoughts, and, of course, about our past. Basically, the phrase means that great art, whether it is music, painting or poetry will far outlive their creators. For example, William Shakespeare. He passed away many centuries ago but his magnificent tragedies, comedies and sonnets are still alive. They will always be the greatest literature masterpieces of the world. And many artists, composers and poets were not famous inter vivos, their works were not popular or were fundamentally different with the demands of the government, and they live on the breadline. But after their deaths their works became appreciated at their true value. For example, one of the greatest Russian composer Modest Musorgsky did not manage to show his compositions to people openly, in all of their beauty because they were too sharp and truthful and, of course, his works were banned to perform. He was distraught and began drinking alcohol and died in destitution. But after his death, the time has changed and his masterpieces were appreciated and they are still one of the most wonderful music compositions of the world. The works of artists, composers, sculptures can go on for many generations. Life seems so incomparably short to great art. And we do not even notice how life goes. Life can end, but art is immortal. And all of the creators are also alive in their masterpieces and in our souls.

The Odessy essays

The Odessy essays An epic hero is a larger than life figure who embodies the ideals of a nation or race. Epic heros take part in long dangerous adventures and accoplish great deeds, requireing great courage and super human strength. In my opinion I don't think that Odysseus is an epic hero. He isn't an epic hero because the only quality he has is great courage and that isn't much. He didn't save anybody, he cheated on his wife and almost got imself killed. In book 9 Odysseus and his men land on the island of the Cyclopes. They spot a cave and they decide to go and explore it. They find cheeses and pens crowded with lambs. His crew suggests that they take the things and run, but Odysseus was stubborn and styaed in the cave. Odysseus loses two men to the cyclopes. When he eventually outsmarts the cyclopes and gets out of the cave. He yells from his ship and makes fun of the cyclops. The cyclopes then picks up a boulder and throws it at the ship misses and a huge wave sends them almost all the way back to the shore. In the next book, book 10, Odysseus lands on the island of the goddess Circe. He sends half of his men to go and explore the island. The men found a house with wolves and mountain lions that acted like house pets. They entered the great hall , and were fed and seated in lounging chairs. She gave them wine that made them turn into animals. When this happened Eurylochus went back and told Odysseus what happened and said that they should leave and not to go back for the others. Odysseus should have listened to Eurylochus because she made them forget of home and that was another year they spent fooling around. Then in book 12 Odysseus is faced with a challenge. He has to make a choice between Scylla the sea monster that look s like a dragon with 6 heads, or Charybdis the toliet bowl monster. If he chose Scylla the he would lose 6 of his men for sure, if he chose Charybdis then he would either lose all or none of his men inckuding h ...

Cousin Kate and The Choosing poetry comparison Essays

Cousin Kate and The Choosing poetry comparison Essays Cousin Kate and The Choosing poetry comparison Paper Cousin Kate and The Choosing poetry comparison Paper Essay Topic: Christina Rossetti Poems Literature The poem Cousin Kate is written by Christina Rossetti in the 19th century. The Choosing was written in the 20th century by Liz Lochhead. Both poems are about two girls who are equal, and how with the interference of a man and a decision they go in different directions of life. In Cousin Kate betrayal is the theme, whereas, in The Choosing there is more a sense of envy between the characters. Both poems are similar. They consist of men, marriage, love and women. Cousin Kate is a traditional narrative poem. It has been written in first person, narrated by I using the personal pronoun. I is the victim. The poem is set out in quatrains so it has a regular structure. Each stanza has four lines and the poem also rhymes. The Choosing has an irregular structure and it doesnt rhyme on every stanza. Rhythm is only used to emphasise the important parts of the poem. The structure of both poems can tell us when the poem was written. Both poems also differ from each other. One difference would be the title. The title The Choosing tells us that a decision was made. The is a definite article and Choosing is a verb, which is a doing word. The purpose of a title is to give the reader an idea to what the poem could be about. It has been used to mislead the reader, it gives you false expectations until you meet the point that the title is relating to in the poem. And wonder when the choices got made we dont remember making. This tells us that a choice was made, but I or Mary didnt decide. The choice was made by Marys father, they moved to a different home. This distanced I and Marys friendship so they took different paths of life. The writer has used caesuras to once again emphasise important parts of the poem. The title Cousin Kate is a proper noun because it is a name. In this poem the writer has used oxymoron to contrast both parts of Is life. To lead a shameless shameful life. This oxymoron tells us that Is life is shameless and shameful, she is trying to express the difference of her present life with her past life. Her past life was shameless because she was an ordinary cottage maiden living an ordinary life, until the Lord found her out and filled her heart with care. Her present life is shameful because she has lost her virginity before marriage. In the 19th century this was considered serious. Women were humiliated and thrown out of their homes, it was a shameful life. In Cousin Kate I was a cottage maiden along with her cousin Kate. Contented with my cottage mates. This phrase tells us that I was better off in her past life before the Lord interfered. She wasnt mindful, but she was fair. The Lord took advantage of Is beauty. He lured her to his palace home and used her as his plaything. I however, was unable to see the Lords true colours; she may have truly loved the Lord until she found out about his affair with her cousin Kate. He changed me like a glove. This simile has been used to emphasise how easy it was for the Lord to change Is way of thinking. He tricked her into loving him and he used her to make himself look good to the public. When he was satisfied with her, he became bored and then he noticed Kate. I was cast by. This also tells us that the 19th century had a patriarchal society. Men had to be the boss; only men were permitted to have a job. Women were expected to stay home and take care of their children. Only men were allowed to divorce their wives. The neighbours call you good and pure, call me an outcast thing. I is disgraced; she is pointed at and humiliated. Nevertheless, she has something the Lord would give lands for; she has the Lords fair-haired son. Her shame, but her pride and a gift that Kate can never give the Lord. In The Choosing I and Mary are equal and young. With the same coloured ribbons in mouse coloured hair. This tells us that they are young because they wear ribbons on their mouse coloured hair. The word mouse is a synonym to a light brown colour. Synonyms are used to include other words with the same meaning. It also tells us that they are equal and normal average girls. Both girls were first equal and equally proud. We curtseyed to the Lady Councillor for copies of Collins Childrens Classics. This tells us that both girls were equally clever. The writer has used an alliteration to slow down the rhythm and make it stand out to show how important education was then. However, I had always felt a bit jealous of Mary. And my terrible fear of her superiority at sums. This tells us that Mary was a little better at Maths than I. This frightened I a little because Mary would become better than her so they would no longer be equal anymore. I felt jealous. The writer has also used and, a conjunction to show Is agony and feelings of envy for Mary. Ten years later on a Saturday- I am coming home from the library. This tells us that there is a change in time, it is the present tense. It also tells us that she wants to learn and get a good job. She has just come back from the library, she may have been studying there, and she is determined not to go back to the old same life. She wants to see the difference and change in an educated life from an ordinary life. In Cousin Kate Kate is described as good and pure. They are positive adjectives because they describe a person in a good way. Kate is described this way because she is still a virgin. I on the other hand is pregnant with the Lords baby. Kate grew fairer than I. The Lord chose Kate while I was cast by. He bound you with his ring. This tells us that the Lord proposed to Kate. The word bound is a verb; the writer has used this verb because she wants to express to the reader that Kate is restricted from her freedom, she is trapped in his clutches, and theres no escape. This tells us that in the 19th century women were controlled by men, and they were only to do as they were told. Your love was writ in sand. This is a metaphor used to explain to the reader that Kates love for the Lord is false. Kate is interested in the Lords money. Her love can wash away like sand. Kate may be good and pure, but under her pretty face lays greed and selfishness. In The Choosing Mary is a quiet character. I dont know exactly why they moved, but anyway they went. Something about a three-apartment and cheaper rent. Rhythm is used in these two phrases because this is where the choice gets made. It has to stand out to enable the reader to notice. This tells us that Marys father may have had financial difficulties or lost his job so they had to move homes. This also tells us that Mary may have had to live her life uneducated because her father couldnt afford it. It is Marys father who makes the decision of their lives. Mary is a simple and ordinary schoolgirl, but she may have been beautiful to find a handsome husband. Sitting near me on the bus, Mary with a husband who is tall, curly haired, has eyes for no one else but Mary. This sentence has a hurenthasis caesura. It plainly states that Marys husband is devoted to her. The adjectives used in this sentence to describe Marys husband tell us that he is a handsome and good-looking man. This makes I feel jealous of Mary when she sees her on the bus. One other thing that makes I feel envious is when she realises that Mary is pregnant. Her arms are round the full-shaped vase that is her body. This is a metaphor that has been used to tell the reader that Mary is pregnant so she is happy and settled in her marriage. This tells us that in the 20th century women were less controlled by men. Men were beginning to take relationships seriously. The Lord in Cousin Kate praised Is flaxen hair to ensure her that he could be trusted. She fell for the Lords words, but her trust was betrayed after the Lord left her for another women. He wore me like a silken knot. This simile tells us that the Lord found it easy to gain Is trust. However, the Lord cannot completely remove I from his life because she has his son. The Lord needs an heir so he would give lands for one. Marys father in The Choosing is in a working class situation. He has been described in a way to make him sound strict. Marys father, mufflered, contrasting strangely with the elegant greyhounds by his side. This tells us that he isnt a very friendly father. He doesnt believe in high-school education especially for girls so he is sexually double standard and very stereotypical about girls. It was because of his decisions Mary and I took different paths of life. In conclusion, both poems are similar because they consist of women and womens role. Both poems have been written by women. In the 19th century women were expected to get married before they become pregnant. I disobeyed this traditional rule and so she got punished for it. In The Choosing I became jealous of her childhood friend. In the 20th century women were free, they were permitted to work and learn. There was no rush in marriage. The difference is the fact that in both poems the society is different, it is better in the 20th century. Women are included as useful.

USS Coral Sea (CV-43) - Aircraft Carrier

USS Coral Sea (CV-43) - Aircraft Carrier USS Coral Sea (CV-43) - Overview: Nation:  United States Type:  Aircraft Carrier Shipyard: Newport News Shipbuilding Laid Down: July 10, 1944 Launched:  April 2, 1946 Commissioned:  October 1, 1947 Fate:  Scrapped, 2000 USS Coral Sea (CV-43) - Specifications (at commissioning): Displacement:  45,000 tons Length:  968 ft. Beam:  113 ft. Draft:  35 ft. Propulsion:  12 Ãâ€" boilers, 4 Ãâ€" Westinghouse geared steam turbines, 4 Ãâ€" shafts Speed:  33 knots Complement:  4,104 men USS Coral Sea (CV-43)- Armament (at commissioning): 18 Ãâ€" 5 guns84 Ãâ€" Bofors 40 mm guns68 Ãâ€"  Oerlikon 20 mm cannons Aircraft 100-137 aircraft USS Coral Sea (CV-43)  - Design: In 1940, with the design of the Essex-class carriers nearly finished, the US Navy commenced an examination of the design to ascertain whether the new ships could be changed to incorporate an armored flight deck.   This alteration came under consideration due to the performance of the Royal Navys armored carriers during the opening years of World War II.   The US Navys review found that though armoring the flight deck and partitioning the hanger deck into several sections reduced damage in battle, adding these changes to the Essex-class ships would greatly reduce the size of their air groups.   Unwilling to limit the Essex-class offensive power, the US Navy decided to create a new type of carrier that would retain a large air group while adding the wanted protection.   Significantly larger than the Essex-class, the new type that became the Midway-class would be able to carry over 130 aircraft while including an armored flight deck.   As the new design evolved, naval architects were forced to reduce much of the carriers heavy armament, including a battery of 8 guns, in order to reduce weight.   Also, they were compelled to spread the class 5 anti-aircraft guns around the ship rather than in the planned dual mounts.   When finished, the Midway-class would be the first type of carrier to be too wide to use the Panama Canal. USS Coral Sea (CV-43) - Construction: Work on the third ship of the class, USS Coral Sea (CVB-43), commenced on July 10, 1944, at Newport News Shipbuilding.   Named for the critical 1942 Battle of the Coral Sea which stopped the Japanese advance toward Port Moresby, New Guinea, the new ship slid down the ways on April 2, 1946, with Helen S. Kinkaid, wife of Admiral Thomas C. Kinkaid, serving as sponsor.   Construction moved forward and the carrier was commissioned on October 1, 1947, with Captain A.P. Storrs III in command.   The last carrier completed for the US Navy with a straight flight deck, Coral Sea completed its shakedown maneuvers and began operations on the East Coast. USS Coral Sea (CV-43) - Early Service: After completing a midshipmen training cruise to the Mediterranean and Caribbean in the summer of 1948, Coral Sea resumed steaming off the Virginia Capes and took part in long-range bomber testing involving P2V-3C Neptunes.   On May 3, the carrier departed for its first overseas deployment with the US Sixth Fleet in the Mediterranean.   Returning in September, Coral Sea aided in the activation of the North American AJ Savage bomber in early 1949 before making another cruise with the Sixth Fleet.   Over the next three years, the carrier moved through a cycle of deployments to the Mediterranean and home waters as well as was re-designated an attack aircraft carrier (CVA-43) in October 1952.   Like its two sister ships, Midway (CV-41) and Franklin D. Roosevelt (CV-42), Coral Sea did not participate in the Korean War.    In early 1953, Coral Sea trained pilots off the East Coast before again departing for the Mediterranean.   Over the next three years, the carrier continued a routine cycle of deployments to the region which saw it host a variety of foreign leaders such as Francisco Franco of Spain and King Paul of Greece.   With the beginning of the Suez Crisis in the fall of 1956, Coral Sea moved to the eastern Mediterranean and evacuated American citizens from the region.   Remaining until November, it returned to Norfolk in February 1957 before departing for Puget Sound Naval Shipyard to receive a SCB-110 modernization.   This upgrade saw Coral Sea receive an angled flight deck, enclosed hurricane bow, steam catapults, new electronics, removal of several anti-aircraft guns, and relocation of its elevators to deck edge. USS Coral Sea (CV-43) - Pacific: Rejoining the fleet in January 1960, Coral Sea debuted the Pilot Landing Aid Television system the following year.   Allowing pilots to review landings for safety, the system quickly became standard on all American carriers.   In December 1964, following the Gulf of Tonkin Incident that summer, Coral Sea sailed for Southeast Asia to serve with the US Seventh Fleet.   Joining USS Ranger (CV-61) and USS Hancock (CV-19) for strikes against Dong Hoi on February 7, 1965, the carrier remained in the region as Operation Rolling Thunder began the following month.   With the United States increasing its involvement in the Vietnam War, Coral Sea continued combat operations until departing on November 1. USS Coral Sea (CV-43) - Vietnam War: Returning to the waters of Vietnam from July 1966 to February 1967, Coral Sea then crossed the Pacific to its home port of San Francisco.   Though the carrier had officially been adopted as San Franciscos Own, the relationship proved icy due to the residents anti-war feelings.   Coral Sea continued to make annual combat deployments in July 1967-April 1968, September 1968-April 1969, and September 1969-July 1970.   In late 1970, the carrier underwent an overhaul and began refreshed training early the next year.   En route from San Diego to Alameda, a severe fire erupted in the communications rooms and began to spread before the heroic efforts of the crew extinguished the blaze.    With anti-war sentiment increasing, Coral Seas departure for Southeast Asia in November 1971 was marked by crew members taking part in a peace demonstration as well as protesters encouraging sailors to miss the ships departure.   Though an on-board peace organization existed, few sailors actually missed Coral Seas sailing.   While on Yankee Station in the spring of 1972, the carriers planes provided support as troops ashore battled the North Vietnamese Easter Offensive.   That May, Coral Seas aircraft took part in the mining of Haiphong harbor.   With the signing of the Paris Peace Accords in January 1973, the carriers combat role in the conflict ended.   After a deployment to the region that year, Coral Sea returned to Southeast Asia in 1974-1975 to aid in monitoring the settlement.   During this cruise, it aided Operation Frequent Wind prior to the fall of Saigon as well as provided air cover as American forces resolved the Mayaguez incident. USS Coral Sea (CV-43) - Final Years: Reclassified as a multi-purpose carrier (CV-43) in June 1975, Coral Sea resumed peacetime operations.   On February 5, 1980, the carrier arrived in the northern Arabian Sea as part of the American response to the Iran Hostage Crisis.   In April, Coral Seas aircraft played a supporting role in the failed Operation Eagle Claw rescue mission.   After a final Western Pacific deployment in 1981, the carrier was transferred to Norfolk where it arrived in March 1983 after an around-the-world cruise.   Sailing south in early 1985, Coral Sea sustained damage on April 11 when it collided with the tanker Napo.   Repaired, the carrier departed for the Mediterranean in October.   Serving with the Sixth Fleet for the first time since 1957, Coral Sea took part in Operation El Dorado Canyon on April 15.   This saw American aircraft attack targets in Libya in response to various provocations by that nation as well as its role in terrorist attacks.    The next three years saw Coral Sea operate in both the Mediterranean and the Caribbean.   While steaming the latter on April 19, 1989, the carrier rendered aid to USS Iowa (BB-61) following an explosion in one of the battleships turrets.   An aging ship, Coral Sea completed its final cruise when it returned to Norfolk on September 30.   Decommissioned on April 26, 1990, the carrier was sold for scrap three years later.   The scrapping process was delayed several times due to legal and environmental issues but was finally completed in 2000.   Selected Sources DANFS: USS Coral Sea  (CV-43)NavSource: USS Coral Sea  (CV-43) USS Coral Sea  (CV-43) Association

France Nationalism Essay Example | Topics and Well Written Essays - 2500 words

France Nationalism - Essay Example n the late 18th century, tracing back to events like the French revolution (Smith 3-7) Nationalism in France relates to among other things, the nation’s growth process, feeling of belonging among the citizens, political and social movements on its behalf and the general and particular doctrine of France being nation (Stovall & Van 33-191). Nationalism emerges in two categories with that of France being civic in nature besides demonstrating some unique and special features. Nationalism in the nation emerges in different phases with the present and past trends sharing some similarities while also exhibiting differences. Moreover, the negative and positive impacts of the concept which hinges extensively on the French revolution are widespread. Among the impacts institute economic changes in France. Further, there exist future prediction of the economy and other facets of French nationalism being among the frequently discussed subjects in the nation’s history. Nationalism in France is a factor that incessantly grows. The process is social and political in nature just as the chase is in other parts of the globe. This manifests in the involvement of political entities in the espousal of the standpoints of the Political Party National Front. This is in line with the party’s growing popularity. According to the article, ‘France: The Growing Popularity of Nationalism’ (n.p), this movement reflects on the ideals of the party which point to the failure of multiculturalism. Moreover, the incursion of immigrants also continues to put at risk the traditional secularism nature of the nation. According to Fraioli (pp. 55-71), French nationalism is a factor of the struggles of Joan of Arc whose reference to her supporters as Frenchmen attained a lot of popularity. Besides the period after the French revolution saw French nationalism rise as a movement. The ideals of equality, fraternity and liberty which defined the French revoluti ons became part of the phenomenon

Coursework Essay Example | Topics and Well Written Essays - 2000 words

Coursework - Essay Example This paper presents results from a research project aiming at developing an architecture supporting local mobility within hospital. The architecture is based on fieldwork and mostly on the knowledge derived from a large number of reliable sources. The fieldwork has emphasized the differences between remote mobility, where users travel over long distances, and local mobility, where users walk around within a fixed set of building. Based on an in depth study, I conclude that local mobility puts up three requirements for computer support;(i) it should integrate into the existing infrastructure (ii) it should support the use of various heterogeneous devices, and (iii) it should enable seamless application roaming between these devices. The paper describes how these requirements were realized in an architecture for local mobility, and how the architecture can be implemented in the health care domain and the costs involved in it and the various benefits gained from it.

Components of a research article Essay Example | Topics and Well Written Essays - 1000 words

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Design internship report Essay Example | Topics and Well Written Essays - 1500 words

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Visiting the museums Research Proposal Example | Topics and Well Written Essays - 1000 words

Visiting the museums - Research Proposal Example Paintings and sculptures are some of the fascinating views found in the museum. All these together with creative drawings and paintings add up to more than 20, 000 collections of creative works. There are six exhibitions that are permanent in the National Portrait Gallery. It also contains sculptures and drawings of past American presidents. America’s history about the origin of Americans is presented by informed workers in the gallery. The available exhibitions normally feature the prominent people who excelled in entertainment and sports in the 20th century. The Smithsonian American Art Museum holds a large variety of American art. It is most likely the largest collection of American art globally. So many artworks dated from the seventeenth century are present in this museum. The largely inclusive visual arts in the museum present a variety of exhibits of the American history. Visitors are presented with gifts, reading materials and graphics in the stores of the museum. Most of the catalogues and books are on American art. There are millions of artistic objects associated with America’s history. It is hard for a visitor to go through all of these in one day. There are staffs who guide visitors through the museum as well as activities in which they participate in order to facilitate their learning. The museum is situated in the National Mall. This is found between the Capitol Building and the Smithsonian’s National Air and Space Museum. It is usually open from September to June. In the museum visitors learn much about American Indian culture. The museum staffs are experienced people who took me and other visitors all over the exhibitions explaining in detail and answering questions from their audience. They offer guided tours depending on the interests of the visitors. The staffs are American Indian professionals whose experience is evident from the

Consideration and Intention to Create Legal Relation Essay

Consideration and Intention to Create Legal Relation - Essay Example This is a case of acceptance by conduct. Acceptance need not necessarily be in writing. In the case of Carlill v Carbolic Smoke Ball1, Miss Carlill demonstrated her acceptance of the offer by purchasing the smoke ball Another issue for determination is whether there was the intention by the parties to create a legally binding relationship. We will access the issue of promissory estoppels to access the existence of legal relationship between the parties. In England and Wales, Lord Denning interpreted promissory estoppels to be a promise that had been made by one party to another with the intention of creating legal relations2. The promise should be made with knowledge that it is going to be relied on by the other party. In the instance case, the bank approached Bubba with a promise to change the terms in the contract on how the loan was to be repaid following Bubba’s financial crisis. This promise was relied on by Bubba. The bank will therefore not be allowed to go back from it s promise. This is primarily owing to the fact that it had been acted upon by the recipient. After realizing that Bubba’s fortune had turned, the proposal to Bubba to revert to the old system of payment constituted an offer to Bubba which he was entitled to accept or reject. The bank now demands that Bubba should pay the lump sum for eight months as well as repay the loan within a period of three years as per the earlier agreement. The earlier agreement had been revoked upon the establishment of new terms by the bank that was accepted by Bubba. The facts in the high trees case, involved a situation at the beginning of Second World War where High Trees House had leased some flat in London from Central property. As a result of the war, occupancy rates drastically went down. The parties therefore made an agreement to cut down the rent that was payable by half. When the situation turned around after the war, Central London property sued for the full rent. The court held that they were entitled to full payment of rent. However, they could not recover the amount that they had agreed to cut down the rent by during the period of war Lord Denning based his decision in the previous case3 which held that if a party to a contract leads another person to believe that they will not enforce their legal rights, they cannot go back from this promise, especially if the other party had accepted the promise and altered his position in reliance on the promise. In the case of Smith v. Hughes4, the court held that for there to be a valid contract, there must be a meeting of the minds of two parties who intend to be legally bound. For there to be meeting of the minds, offeree must communicate his acceptance of the offer to the offeror. It is not necessary that acceptance should be communicated verbally. It can in some situations be inferred from the conduct of the parties. The court in the case of Brodgen v. Metropolitan Railway Company5 held that acceptance can be inferred fr om the conduct. In this case the plaintiff had been supplying the company with coals for some of years. The plaintiff thereafter came up with a suggestion that they needed to enter into a formal contract. Their respective agents met and engaged in some negotiations on the best agreement that they wanted to enter into. The company’s agent then drew up the contract which he sent to the plaintiff for approval. The court held that the company’s acceptance could be inferred from its conduct. By

Visiting the museums Research Proposal Example | Topics and Well Written Essays - 1000 words

Visiting the museums - Research Proposal Example Paintings and sculptures are some of the fascinating views found in the museum. All these together with creative drawings and paintings add up to more than 20, 000 collections of creative works. There are six exhibitions that are permanent in the National Portrait Gallery. It also contains sculptures and drawings of past American presidents. America’s history about the origin of Americans is presented by informed workers in the gallery. The available exhibitions normally feature the prominent people who excelled in entertainment and sports in the 20th century. The Smithsonian American Art Museum holds a large variety of American art. It is most likely the largest collection of American art globally. So many artworks dated from the seventeenth century are present in this museum. The largely inclusive visual arts in the museum present a variety of exhibits of the American history. Visitors are presented with gifts, reading materials and graphics in the stores of the museum. Most of the catalogues and books are on American art. There are millions of artistic objects associated with America’s history. It is hard for a visitor to go through all of these in one day. There are staffs who guide visitors through the museum as well as activities in which they participate in order to facilitate their learning. The museum is situated in the National Mall. This is found between the Capitol Building and the Smithsonian’s National Air and Space Museum. It is usually open from September to June. In the museum visitors learn much about American Indian culture. The museum staffs are experienced people who took me and other visitors all over the exhibitions explaining in detail and answering questions from their audience. They offer guided tours depending on the interests of the visitors. The staffs are American Indian professionals whose experience is evident from the

School Discipline Essay Example for Free

School Discipline Essay Recently, in elementary and lower secondary schools, much effort has been made in Japan to accomplish the aims of moral education, by requiring separate scheduled hours for moral education. The purposes of moral education are shown in the following summary of general principles established in the Course of Study issued by the Ministry of Education. Moral education aims to develop a Japanese citizen who will never lose the consistent spirit of respect for his fellow man; who will realize this spirit at home, at school and in other actural life situations in the society of which he is a member; who strives for the creation of a culture rich in individuality and for the development of a democratic nation and society; and who is able to make a voluntary contribution to the peaceful international society. In order to attain this aim, the following contents is sought in moral instruction in elementary schools. 1) Contents mainly related to the fundamental patterns of behavior in daily life: to maintain safety and secure good health; to develop self-reliance; to observe good manners; to keep oneself neat; to improve the environment; to use things and money effectively; to recognize the value of time. 2) Contents mainly related to moral sentiment and moral judgement: to respect others personality; to control oneself and act according to ones beliefs; to act freely according to ones own judgement or wishes and on ones own responsibility; to be honest and sincere; to love justice and be courageous; to over come difficulties in order to accomplish right aims; to reflect on oneself, listen to the advice of others, and to act with deeper consideration; to act moderately, without selfishness; to behave always with alertness, courtesy and alacrity; to take good care of animals and plants; to have a pure mind. 3) Contents mainly concerned with the development of personality and a creative attitude toward life: to recognize ones own special ability, and try to strengthen it; to strive for the achievement of worthy purposes, and to set for oneself a high goal; to act rationally; to tr3r to improve life with original ideas; always to maintain a studious attitude, and try to pursue truth; to apply positively new ideas. 4) Contents mainly related to the concept that good manners and practical will are indispensable for the member of a nation or a society: to be kind to everybody and to care for the weak or unfortunate; to respect those who devote themselves to the service of others and to appreciate their work; to trust each other and to be friendly; to be fair and impartial to everybody; to be generous; to observe rules and promises; to differentiate between rights and duties; to appreciate labor; to protect public property and public morality; to love ones family; to love ones school; to love the nation with a pride as a Japanese; to understand correctly the people of all the world and cooperate in a friendly manner with them. The contents of moral education for lower secondary schools are almost the same as those for the elementary schools. However, in considering the stages of pupils development, the following objectives are added: To build an attitude of constructive criticism; to develop mutual under-standing and respect between the sexes; to promote open and pure friendship between the sexes; to promote love of truth; to lead pupils to consider what true happiness is and to seek it; to help pupils to enrich their own sentiments; to aid in understanding the inherited culture and to contribute to cultural improvement; to teach pupils to hold humanity in mind always; to train pupils to challenge evil with courage; and not have a narrow fellow-mindedness, but to act with consciousness of being a member of the large community. In upper secondary schools, ethics-civics created as a new subject in the social studies, is intended to develop students who know the human relations in the present society, understands humanity and pursues the ideal in the life of the world. Moral education is to be conducted from the broad point of view through all the activities of the school. Consequently, moral instruction is provided by combining properly various teaching methods, such as discussion, stories to1d by teachers, reading Of b00ks, audio-visual aids, dramatizing and non-classroom activities. In 1963, in order to aid in effectuating the new program of moral instruction, the Ministry of Education published Teachers Manual for Moral instruction and distributed it through the country to guide classroom teachers at each level in the preparation of their moral education hour. CHAPTER IMPROVEMENT OF CONTENT OF- EDUCATION AND DEVELOPMENTOF ABILITY (2) Moral Education in Other Countries In most foreign countries, religion makes a valuable contribution to the moral spirit. In those countries studied, moral education is generally given to pupils through religious instruction in assigned religion classes. In several countries including the U. S. A. and France, religious instruction in public schools is prohibited. Whether the religious instruction in public school is conducted or not, moral and ethical education is given in many cases as a part of other subject, usually civics. In communist countries including the U. S. S. R., it is regarded as a purpose of education to build a citizen who can contribute to the maintenance of a socialist state. For this purpose, moral and ethical trainings given through all educational activities in the schools. Table 30 shows the extent of ofFerings in religious education in ele-mentary and secondary schools in the U. S. A. , the U. K. , and an extensivegroup of European countries. In 13 of the 17 countries listed in Table 30, religion is offered as a separate subject in almost all grades in public elementary and secondary schools. In 11 of the 17 countries, civics is taught in elementary school or secondary school or both. In France, civics at primary level is included in the subject known as education civique et morale. In the U. S. A. civics is usually taught in the 8th grade and upper grades of secondary schools. There is no instruction in separate moral education classes. It is taught through all subjects. Also, in the U. S. S. R. , moral education is not treated separately, but moral training of pupils is given through the whole curriculum. It is a characteristic feature of school education in the U. S. S. R. to provide child labor training at all levels. This labor training aims to give pupils moral training. Moreover, Rules for Pupils, which pupils elementary and secondary schools must obey, are specified by the Department of Education of the R. S. F. S. R. In Rules for Pupils, objectives of moral education are prescribed along with the school principles which pupils must observe. Civics teaching in each country aims to elevate moral sentiments, and to give pupils knowledge and understanding of government, economics and social problems necessary for citizenship. Moral education and civics in the Federal Republic of Germany, Italy, France and Belgium are as follows: Federal Republic of Germany Basic principles of civic education in schools and universities were decided by the Conference of Lander Ministers of Education of 15 June 1950as follows: Civic education should awaken in pupils both a moral response and a determination to act as a responsible member of society. Italy The primary school syllabus published by the Ministry of Education in 1955 states that civics teaching is designed to give the child a general moral, religious and social training. It also emphasizes that religious instruction must enable the child to acquire basic habits of morality, civic and social behavior and hygiene at home, at school and in society; and to give the child a sense of personal responsibility and membership of a group. Regarding civic education courses in upper classes it is stated: love of ones country must be a natural extension of love of ones family, and the awareness of national values should be related to the ideal of international understanding. France. The syllabus in primary education published by the Ministry of Education in 1923 states that moral education must enable the child to grow up as a man with a balanced development of sentiment, intelligence, and conscience. It is also stated that moral instruction is to be designed not only to give the child moral spirit, but also to lead him to realize this spirit in daily life. In primary schools in France, the subject known as education civique et morale is taught as outlined below: 1st grade: Listening to stories (Fontaines fables, Hans Christian Andersons tales, etc. ) and to biographies of great men told by teachers. 2nd and 3rd grades: To accustom the child to acquire good habits through reading of book-lets followed by discussion, and discussion on school events. At third grade the same themes as those of second grade are dealt with more intensively 4th and 5th grades: To listen to narratives or discuss deeds of the individuta1 and social morality concerned with moderation, sincerity, simplicity, kindness, courage, and generosity. To give the child an understanding of the value of labor, a spirit of cooperation with others, observance of promises, understanding of other persons and appreciation of duties to ones family and ones nation. At fifth grade, the same themes as those of forth grade are dealt with more intensively. 6th8th grades: To provide the child consciousness and respect for man, character formation, main duties in life of the individual, at home and in society, and inculcate patriotism, justice and mutual assistance, respect for labor, organization of government and its activities, elementary knowledge of contracts and labor laws in daily life, elementary knowledge of the legislative, administrative and judicial systems, citizens rights and duties and international understanding. Belgium In the middle school of Belgium (3rd and 4th secondary years, age 14 to15), citizenship and patriotism are taught under the following themes: l) Citizens rights: advantages of the democratic and parliamentary system. The chief freedoms guaranteed by the Belgian Constitution. 2) The citizens duties: the ballot; obedience to the Law, military service; paying taxes; giving evidence in court. 3) Patriotism: the countrys prestige and its heritage; the dangers of misguided patriotism. 4) International understanding and a sense of the brotherhood of man. Aids for Civics Teaching in European Countries In a number of countries, separate textbooks are used. Audio-visual aids such as slides, films, radio broadcasts, television, etc. are also used. Table 30. Comparative Table Showing Extent of Offering Of Separate Classes in Religion and Civics Table 31. Teaching Aids for Civics Education in European Countries.

Measuring Concentration of Natural Gas in Air

Measuring Concentration of Natural Gas in Air Valentin Haemmerli Measuring concentration of natural gas in air using a catalytic bead sensor and a Wheatstone bridge circuit Abstract. A vacuum system and a catalytic bead combustible gas sensor were used to calibrate and test an apparatus for measuring the concentration of natural gas in air. Total concentrations ranged between 0%-5% and total pressure from 0.5 bar to 1.5 bar. A Wheatstone bridge circuit was used to measure the output voltage of the sensors and relate this to concentration over the range of pressures. The linear relationship between reaction rate (given by initial rate of change of output voltage) and concentration was most strongly observed at pressures of 1 bar and above. The constant of proportionality for the equation (1) was found to be 8.7  ±0.4 10-4 Vs-1 per % methane for a total system pressure of 1 bar. The relationship broke down for pressures significantly below 1 bar, indicating that the sensors are not reliable in this range. Introduction Catalytic bead sensors, also known as pellistors [1], are used in a wide range of applications in industry to monitor levels of combustible gases. One such combustible gas is the mixture consisting mainly of methane referred to as natural gas. The catalytic bead sensors can be used to monitor the concentration of natural gas in production facilities, coal mines and industrial processes. This is important because if the concentration of natural gas in air exceeds 5% it becomes explosive [2]. It is especially important to monitor methane concentration because it is usually colourless and odourless [3], making it very difficult to detect without sensors. An apparatus to measure concentration of natural gas in air can be used to trigger an alarm when there is a concentration greater than the Lower Explosive Limit (LEL), given as a percentage. At this concentration the mixture of gas and air becomes explosive. The apparatus may need to be applied for different pressure environments, not only atmospheric pressure, for example in applications with chemical processes requiring lower or higher pressures. The apparatus has therefore been tested for a range of pressures from 0.5 -1.5 bar. Theory Sensors The sensors used are catalytic bead sensors. One sensor is made up of two elements, one sensitive and one non-sensitive. The sensors work by catalysing the oxidation reaction of combustible hydrocarbons in the sensitive element which consists of a platinum wire coated in a compound which facilitates the oxidation reaction and also contains the catalyst for this reaction. The non-sensitive element is identical in most regards, but crucially is missing the oxidizing chemical or has had it poisoned, depending on the specific sensor design used. Poisoning means that the catalyst has been reacted with another chemical to make it inert. The non-sensitive element does not react with combustible gases. The elements are supplied with 3V, and heated up to 400-500ËÅ ¡C to speed up the reaction. When the oxidation reaction of combustible gases occurs on the sensitive element, the heat of reaction increases the temperature of the element, which changes the resistance in the platinum wire. Th e non-sensitive element acts as a control for ambient temperature, meaning that in the absence of any combustible gas, the two elements will output exactly the same voltage. This is very useful as it means that change in temperature due to external factors is controlled and the difference in output between the sensitive and non-sensitive elements can be measured using a Wheatstone bridge circuit as described below. This design means that these sensors detect a multitude of different combustible gases and are therefore not useful for distinguishing between them, meaning they are nonspecific [4]. However, they are very useful for situations where monitoring combustibility is of importance, and they can be applied readily to the task of measuring concentration as they are accurate and have a fast response time. The sensors used are sensitive, with a measurement range of 0-100% of the LEL. This corresponds to 0-5% concentration of methane. One downside of these sensors is that they cannot operate in a vacuum as they rely on combustion, which usually requires at least 15% oxygen [4]. They are also at risk of poisoning since they rely on a coat of catalyst and the presence of certain chemicals can result in a reaction with this catalyst, meaning the sensitive element would no longer facilitate the oxidation reaction and the difference in output between the elements would always be zero. Wheatstone Bridge Circuit Jeong-Yeol Yoon states that â€Å"A Wheatstone bridge is an electrical circuit used to measure a very small change in resistance† [5]. A circuit as shown in Figure 1 can be used to measure the output from the sensors, where a small resistance change is expected as a result of the sensitive element heating up due to the presence and reaction of combustible gases. A voltage is supplied at the top and bottom of the diamond of resistors, and the voltage across the middle, between V1 and V2 is measured. The right leg of the bridge should have a large resistance compared to the other leg so that a small change can be detected. The variable resistor allows one to slightly vary the resistance on one leg and so balance the bridge before measurements, zeroing the output. Experimental Method The first step was to test how sensor output related to concentration for a total pressure of 1bar (atmospheric). Care was taken to ensure that all joints and seals of the vacuum system were tight and that all valves were firmly closed. The vacuum system used to prepare test mixtures is shown in Figure 2. P1 and P2, the pressure sensors shown in the figure, were used to measure concentration of natural gas and air. P1 had a range of 3 bar, with the zero set to atmospheric pressure (1bar), and vacuum (0bar) set to -1. This was not very precise, with an uncertainty of  ±0.1bar and was used to fill up the system with compressed air and the pressure shown by this corresponded to total pressure. P2 was a more precise pressure sensor, ranging from 0 to 50 mbar with uncertainty  ±0.5mbar. It was used to carefully add the correct proportion of natural gas to the vacuum, before topping up with compressed air. Using this vacuum system, concentrations ranging from 0-5% natural gas were prepared. Figure 2 also shows the position of the pellistor sensor’s two elements and the connection to the Wheatstone bridge circuit. The output of this circuit was connected to a ÃŽ ¼V meter which was connected to a computer for dat a logging. This had a range of -30.00 to 30.00mV with uncertainty  ±0.01mV. Data logging was carried out for 5 minutes and 30s for concentrations of 1%, 2%, 3%, 4% and 5% at a total pressure of 1 bar. Errors were reduced by zeroing the Wheatstone bridge output using the variable resistor between measurements. This was done to reduce the effect of a natural drift in the output due to very slightly varying conditions in the lab such as temperature and the resistance in the circuit, as well as mechanical vibrations. The bridge circuit supply voltage was kept at a constant 3.00V. Care was taken to leave little time between sealing the system under vacuum and filling with natural gas and air as the seals were not perfect and pressure rose slowly, but noticeably if the system was left at vacuum for an extended period. This procedure was then repeated for a suitable range of concentrations at total pressures of 0.5, 0.75, 1.25, and 1.5 bar. The same considerations were made for reducing error as above. One thing to note is that at total pressures of less than atmospheric there was always a slight influx of outside air, due to the imperfect seals, however the effect of this was negligible. Experimental Results To find a correlation between the concentration of methane and the bridge output voltage we took the gradient of the initial increasing linear section of the raw data. Figure 3 below shows this for the case with concentration 5% of methane with a total pressure of 1 bar. As can be seen, the measured data falls away as reactant, the natural gas, is used up in the reaction. Figure 3 also shows that there is a very sharp spike as the output voltage varied greatly when the sensor was first switched on. This illustrates that care was needed when selecting which section of the curve to use to calculate the gradient. This is the right method to use to find concentration because, according to Hammett, â€Å"the rate of any chemical reaction is proportional to the product of the concentrations of the substances actually involved in the reaction.† [7] and the gradient of Figure 3 is a rate of reaction. The next step was to establish the gradients, or initial reaction rates, of 1%, 2%, 3%, and 4% methane mixtures. These are shown in Figure 4, along with 5%, for a total pressure of 1 bar. Figure 5 shows these gradients again, but all in order and passing through the origin to better show the steady increase in gradient. Figure 6 shows processed data for 1 bar total pressure. The gradients of the lines from Figures 4 and 5 are plotted against their concentration. This allows us to find a constant linking the raw data to the concentration for this pressure. Table 1 goes on to show the values of this constant for the other pressures analysed. The raw data for these is not shown here, but the process and data is similar to that for 1 bar. Figure 7 shows the relation between the pressure and the concentration. Also included are a second order polynomial and a linear trend line (fitted by least squares). Vertical error bars are from standard error in Table 1 and horizontal error bars from  ±0.1bar uncertainty in total pressure. Discussion Figure 6 shows the gradients of the lines in Figures 4 and 5, meaning the rates of reactions at different concentrations, plotted against the concentration of methane. This gives us a relationship between concentration and the initial rate of reaction, the quantity derived from the raw data, for a specific total pressure. For 1 bar this was 8.7 ±0.4 10-4 Vs-1 per % methane. The error in this comes from a combination of the uncertainty in the pressure measurement leading to uncertainty in concentration corresponding to  ±0.1% in the worst case and a small random error in the output voltage of the bridge circuit corresponding to  ±2Ãâ€"10-4V. Figure 7 includes both a polynomial fit and a linear fit. It is unclear if the relationship remains linear or takes some other form at low pressure. The polynomial is almost linear for the three higher pressures, which indicates a strong relationship between pressure and reaction rate for higher pressures. The values and their associated errors in Table 1 come from each plot of initial reaction rate (rate of change of voltage) against concentration for the different pressures. The error is the standard error for these plots. There was a breakdown of the relationship at low pressures. Data for 0.5 bar total pressure was not included in the results because no clear relationship between output and concentration was found. This indicates that the sensors are not suitable for low pressures, especially when coupled with low concentrations. This resulted in very little output from the sensors, making it difficult to reliably determine an initial reaction rate, which is vital for obtaining a relationship between the raw data and the concentration. The reason for this lack of output was that not enough natural gas particles were interacting with the sensitive element to cause it to heat up and also due to a lower oxygen concentration also slowing down the reaction. This is not a problem in the commercial applications of these types of sensors as they are typically used to detect high concentrations of combustible gases at atmospheric pressure. This does highlight a weakness in the apparatus when used for finding unknown concentrations, however. Another weakness was the inability to measure large pressures precisely, leading to large errors in the total pressure measurements. This has an increased effect on low pressures, which is a further reason for the less reliable data. Empirical Relationship If we give the initial rate of reaction a constant,, and a function of pressure, , then (2) where is the concentration of methane, is determined experimentally from the sensor data and is the polynomial relationship from Figure 7, (3) with the appropriate total pressure, found experimentally from the pressure sensors on the vacuum system, substituted. Using this equation it is possible to use the sensors to determine the concentration of an unknown mixture. Conclusions The aim was to build an apparatus capable of determining the concentration of natural gas in air up to 5%. In order to do this it was necessary to first establish the relationship between sensor output and concentration. This was then repeated at different pressures to understand the effect of a different pressure on the relationship between sensor output and concentration. Finally it was possible to use these relationships to determine the concentration of an unknown mixture of gas and air. The constant of proportionality for 1 bar pressure was found to be 8.7 ±0.4 10-4 Vs-1 per % methane. For 0.75 bar it was found to be 6.5 ±1.6 10-4 Vs-1 per % methane, 1.25 bar was 16.2 ±0.8 10-4 Vs-1 per % methane, and 1.5 bar was 25.3 ±1.9 10-4 Vs-1 per % methane. No correlation was found between sensor output and concentration for 0.5 bar. Appendix Division of labour among group members: Giuseppe Guarino –main tasks were constructing bridge circuit on protoboard and constructing and soldering strip board circuit which was finally used in data collection David Griggs –main tasks were configuring CassyLab software and importing raw data into Microsoft Excel Valentin Haemmerli –main tasks were preparing mixtures of natural gas and compressed air in vacuum system and researching sensor operation guidelines Shared responsibilities –everyone shared the tasks of checking the circuit, building the vacuum system apparatus and preliminary data analysis. References [1]Operating Combustible Gas Sensors, ed: Sixth Sense (sensor manufacturer). [2]Material Safety Data Sheet: Methane, ed: Air Products, 1999. [3]J. G. Speight, CHAPTER 1: History and Uses, in Natural Gas: A Basic Handbook, ed: Euromoney Institutional Investor PLC / Gulf Publishing Company, 2007, pp. 1-33. [4]L. T. White, 4 Hazardous Gas Monitoring Sensors, in Hazardous Gas Monitoring (Fifth Edition), L. T. White, Ed., ed Norwich, NY: William Andrew Publishing, 2001, pp. 81-116. [5]J.-Y. Yoon, Wheatstone Bridge, in Introduction to Biosensors, ed: Springer New York, 2013, pp. 75-86. [6]Catalytic Elements CAT16, ed: Sixth Sense (sensor manufacturer). [7]L. P. Hammett, Physical organic chemistry reaction rates, equilibria, and mechanisms. New York; St. Louis; San Francisco [etc.]: McGraw-Hill, 1970.