92 research outputs found
Examining mechanical properties of single acetaminophen crystal using nanoindentation methods
No full textThe pharmaceutical industry incurs substantial loss in revenue and consumer confidence with inefficient manufacturing practices. Large scale processing of organic compounds is challenging due to its sensitivity to environmental conditions and the unpredictable breakage behavior of tablets under applied stress. Tablet compaction and particle size reduction through milling induces variability in the end product. Variability in powder flow, stress induced transformation in polymorphic compounds, re-crystallization after compaction, and lack of content uniformity are some factors that translate into poor product quality. These challenges can be partially resolved by a better understanding of mechanical properties of crystalline pharmaceutical materials at single particle level. The endeavor of this study was to understand the breakage behavior of various planes of a single Acetaminophen crystal using nanoindentation instrumentation. The results of the study indicated that the Acetaminophen crystal is anisotropic with respect to hardness and Young’s modulus values. Analysis of the load-depth curve, discontinuities on the loading and unloading cycle were observed, as well as pop-in events during constant load intervals. Furthermore, the frequency of pop-in events on the loading depth curve was found to correlate with the elasticity of the planes in question. It was also apparent that the organic compound was sensitive to environmental conditions. Varying strain rates effects different planes of the same crystal and also in adhesion reflected sensitivity to environmental conditions. The exact mechanism by which the crystal deforms is still unknown. However it is theorized that it could be through partial dislocations and crack propagations.M.S.Includes bibliographical referencesby Hiral Parik
TetrUSS Capabilities for S and C Applications
No full textTetrUSS is a suite of loosely coupled computational fluid dynamics software that is packaged into a complete flow analysis system. The system components consist of tools for geometry setup, grid generation, flow solution, visualization, and various utilities tools. Development began in 1990 and it has evolved into a proven and stable system for Euler and Navier-Stokes analysis and design of unconventional configurations. It is 1) well developed and validated, 2) has a broad base of support, and 3) is presently is a workhorse code because of the level of confidence that has been established through wide use. The entire system can now run on linux or mac architectures. In the following slides, I will highlight more of the features of the VGRID and USM3D codes
Comparison of microwave and conventional frying on quality attributes and fat uptake in potatoes
No full textOil content is an important quality attribute in fried products. Oil uptake is influenced by several interdependent factors that define the final oil content in a fried product. In this study microwave frying was investigated for its potential in reducing fat content of fried foods. A comparative analysis of moisture, fat, color and texture was done for conventional and microwave fried French fries. Experiments were performed in triplicate for both frying operations at temperatures of 177°C, 185°C and 193°C for time duration's of 60, 90 and 120 seconds. Decrease in moisture content was observed with frying time, but moisture did not significantly differ between the two frying operations. Fat reduced by 0.08 g/g solids at 185°C and by 0.07 g/g/ solids at 193°C for 120 sec microwave frying compared to conventional frying. The lightness parameter (L*) decreased to a lesser extent in microwave frying than conventional frying. The real-time pressure and temperature profiles indicated that during microwave frying, gage pressure had greater magnitudes and the temperature increased to boiling point at a faster rate for microwave frying compared to conventional frying. Negative gage pressures had higher magnitudes and lasted longer during conventional frying than microwave frying. Higher magnitude of positive gage pressure for longer frying duration and lower magnitude of negative pressure in microwave frying than conventional frying is expected to have caused lower fat uptake with the former frying method than the latter. For conventional frying, there were no significant differences in the elastic modulus for all frying temperatures and frying times. Whereas for microwave frying, significantly lower magnitudes of G(t) were observed at 177°C for 90 secs frying time compared to 60 secs and 120 secs at the same temperature. Significantly lower magintudes of G(t) values for MF were also observed at 185°C for 120 secs frying time compared to 60 and 90 secs at the same temperature. Consumer test confirmed that reduced fat uptake during microwave frying did not compromise with desirable attributes of French fries.Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2018-05-01The student, Archana Parikh, accepted the attached license on 2016-04-22 at 14:18.The student, Archana Parikh, submitted this Thesis for approval on 2016-04-24 at 15:06.This Thesis was approved for publication on 2016-04-28 at 08:02.DSpace SAF Submission Ingestion Package generated from Vireo submission #9442 on 2016-07-07 at 14:17:55Made available in DSpace on 2016-07-07T21:18:01Z (GMT). No. of bitstreams: 2
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Synthesis, Spectral Studies and Therapeutic Activity of some Heterocyclic Compounds
No full textNot availabl
A ONE POT SYNTHESIS OF PYRANO(C)CHROMENES AS ANTIMICROBIAL AGENTS
No full textABSTRACT The 4H-pyran nucleus is a fertile source of biologically important molecule possessing a wide spectrum of pharmacological activities. The advantage of one pot multicomponent reactions are synthetic efficiency, high atom-economy, structural diversity, operational simplicity and to avoid waste product formed in multi-step reaction. The synthesis ofdihydropyrano[c]chromene derivatives have been undertaken by the condensation of 4-hydroxycoumarin and 4-hydroxy-8-isopropyl-5-methylcoumarin with malononitrile and aromaticaldehyde using diammoniumhydrogen phosphate as a catalyst and alcohol as a solvent. The products obtained are to be characterized using spectral techniques like IR, NMR and mass spectrometry. The synthesised products are to be tested for antimicrobial activity against Gram-positive and Gramnegative bacterial strains, antifungal activity
Effect of diuretics on sodium, potassium and chloride levels- a cross sectional study
No full textBackground: Diuretics are one of the widely used class of drugs used in various cardiovascular and other disorders. However, they can cause various metabolic adverse effects, electrolyte imbalance being among important changes.Methods: A cross sectional study was conducted in which patients diagnosed with hypertension for at least one month were included. Over a period of 6 months patients were enrolled irrespective of whether they were taking diuretics or not. Demographic details, drug therapy and electrolyte levels were recorded in a proforma. Data was analyzed for difference in serum electrolyte levels between diuretic and nondiuretic groups as well as between different diuretic groups.Results: Out of total 177 participants, 71 were on diuretic therapy. There was significant difference in mean serum sodium (S. Na), potassium (S. K) and chlorine (S. Cl) levels between diuretic and nondiuretic groups (P<0.05). Hyponatremia, hypokalemia and hyperkalemia were observed. Thiazide diuretic group showed significantly greater hyponatremia compared to other diuretics (P=0.028). Hyperkalemia was observed in participants receiving K sparing diuretic or combination of loop and K sparing diuretics. Old age and number of comorbidities showed negative association with S. Na. Females had significantly more hyponatremia than male participants.Conclusions: The study confirms that diuretics cause various abnormalities in electrolytes namely Na and K levels. Old age, comorbidities and female sex are risk factors for hyponatremia
Completeness for game logic
No full textGame logic was introduced by Rohit Parikh in the 1980s as a generalisation of propositional dynamic logic (PDL) for reasoning about outcomes that players can force in determined 2-player games. Semantically, the generalisation from programs to games is mirrored by moving from Kripke models to monotone neighbourhood models. Parikh proposed a natural PDL-style Hilbert system which was easily proved to be sound, but its completeness has thus far remained an open problem. In this paper, we introduce a cut-free sequent calculus for game logic, and two cut-free sequent calculi that manipulate annotated formulas, one for game logic and one for the monotone mu-calculus, the variant of the polymodal mu-calculus where the semantics is given by monotone neighbourhood models instead of Kripke structures. We show these systems are sound and complete, and that completeness of Parikh's axiomatization follows. Our approach builds on recent ideas and results by Afshari & Leigh (LICS 2017) in that we obtain completeness via a sequence of proof transformations between the systems. A crucial ingredient is a validity-preserving translation from game logic to the monotone mu-calculus
An econometric model of the monetary sector of the Bangladesh economy
No full textAn econometric model of the monetary sector of Bangladesh is formulated and estimated using annual data for the period 1974-87. The model is evaluated using a range of diagnostic tests and the results from dynamic simulations. The simulations indicate that, historically, inflation, real output growth and monetary growth are all consistent with a structuralist framework in which exogenous shocks such as harvest failures play a leading role in monetary expansions via their effects on food prices. Accommodationist monetary polices may generate further inflationary pressures, though there may be short periods during which monetary expansions increase real output. Excess supplies of real money balances do not appear to have any significant impact on real expenditures. -Author
Poverty, growth and policy options
No full textExamines and tests the hypotheses whether the relationship between poverty and development is U-shaped or rectangular hyperbolic. While testing these hypotheses, other variables such as life expectancy, adult literacy rate, and special country characteristics are taken into consideration. The use of international cross-section data of 34 countries on an essentially dynamic issue was made in the absence of time-series data. The authors find that poverty, measured by the proportion of people below US $35.00 per capita (in constant 1975 prices), starts declining at a decreasing rate and reaches an asymptotic level of 5 to 8% of the population below the poverty line.-Author
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