562 research outputs found
A multiscale constitutive model for intergranular stress corrosion cracking in type 304 austenitic stainless steel
Intergranular stress corrosion cracking (IGSCC) is a fracture mechanism in sensitised austenitic stainless steels exposed to critical environments where the intergranular cracks extends along the network of connected susceptible grain boundaries. A constitutive model is presented to estimate the maximum intergranular crack growth by taking into consideration the materials mechanical properties and microstructure characters distribution. This constitutive model is constructed based on the assumption that each grain is a two phase material comprising of grain interior and grain boundary zone. The inherent micro-mechanisms active in the grain interior during IGSCC is based on crystal plasticity theory, while the grain boundary zone has been modelled by proposing a phenomenological constitutive model motivated from cohesive zone modelling approach. Overall, response of the representative volume is calculated by volume averaging of individual grain behaviour. Model is assessed by performing rigorous parametric studies, followed by validation and verification of the proposed constitutive model using representative volume element based FE simulations reported in the literature. In the last section, model application is demonstrated using intergranular stress corrosion cracking experiments which shows a good agreement
A multiscale constitutive model for intergranular stress corrosion cracking in type 304 austenitic stainless steel
Intergranular stress corrosion cracking (IGSCC) is a fracture mechanism in sensitised austenitic stainless steels exposed to critical environments where the intergranular cracks extends along the network of connected susceptible grain boundaries. A constitutive model is presented to estimate the maximum intergranular crack growth by taking into consideration the materials mechanical properties and microstructure characters distribution. This constitutive model is constructed based on the assumption that each grain is a two phase material comprising of grain interior and grain boundary zone. The inherent micro-mechanisms active in the grain interior during IGSCC is based on crystal plasticity theory, while the grain boundary zone has been modelled by proposing a phenomenological constitutive model motivated from cohesive zone modelling approach. Overall, response of the representative volume is calculated by volume averaging of individual grain behaviour. Model is assessed by performing rigorous parametric studies, followed by validation and verification of the proposed constitutive model using representative volume element based FE simulations reported in the literature. In the last section, model application is demonstrated using intergranular stress corrosion cracking experiments which shows a good agreement
Acute-on-chronic Liver Failure: MELD Score 30-day Mortality Predictability and Etiology in a Pakistani Population
Background: Cirrhosis is a pathological condition that ultimately leads to liver failure. Acute on chronic liver failure (ACLF) has a high short term mortality rate. Viral hepatitis is the most common cause of liver failure in our local population. We carried out this study to identity the 30-day mortality and etiology of patients presenting with ACLF using Model for End-Stage Liver Disease (MELD) score predictability.
Methodology: This was a descriptive case series, conducted at Sheikh Zayed Hospital, Lahore, Pakistan from January 31, 2018 to July 30, 2018. One hundred and eighty five patients who met the inclusion criteria were enrolled using 95% confidence level and 4% margin of error. Data was entered and analyzed with SPSS version 23.0. Numerical variables including age was presented by Mean Β± S.D. Categorical variables i.e. gender, etiology of acute-on-chronic liver failure and 30-day mortality were presented by frequency and percentage. Data was stratified for age, gender, duration of chronic liver disease and MELD grade to address the effect modifiers. Post-stratification chi-square test was calculated using 95% significance (pβ€0.05).
Results: Majority of the enrolled patients were male (74.6%) while only 25.4% of the patients were female. One hundred and thirty patients (70.3%) had underlying viral hepatitis while twelve patients (6.5%) and forty three patients (23.2%) presented with alcoholic liver disease and drug-induced ACLF, respectively. Eighty patients (43.2%) died within 30 days of admission.The 30-day mortality with respect to MELD grade was statistically significant (p<0.001) with the highest mortality noted in grade-IV and thirty five patients (43.8%) dying within 30 days of admission (p<0.001). Grade-II and III MELD scores also contributed to the 30-day mortality with twenty three patients (28.8%) and nineteen patients (23.8%) dying within 30 days of admission (p<0.001).
Conclusion: MELD scores are able to accurately predict the short-term mortality in patients with ACLF and viral hepatitis was the most common etiology in our population. Early detection and use of appropriate prognostic models may alleviate mortality and morbidity in paitents with ACLF
On non commutative sinh-Gordon Equation
We give a noncommutative extension of sinh-Gordon equation. We generalize a
linear system and Lax representation of the sinh-Gordon equation in
noncommutative space. This generalization gives a noncommutative version of the
sinh-Gordon equation with extra constraints, which can be expressed as global
conserved currents.Comment: 7 Page
Conserved Quantities in Noncommutative Principal Chiral Model with Wess-Zumino Term
We construct noncommutative extension of U(N) principal chiral model with
Wess-Zumino term and obtain an infinite set of local and non-local conserved
quantities for the model using iterative procedure of Brezin {\it et.al}
\cite{BIZZ}. We also present the equivalent description as Lax formalism of the
model. We expand the fields perturbatively and derive zeroth- and first-order
equations of motion, zero-curvature condition, iteration method, Lax formalism,
local and non-local conserved quantities.Comment: 14 Page
Dose dependent hepatotoxic effects of dry seed phaseolus vulgaris linn. (red kidney beans) on rabbits
Growing research on beans suggest that they are good for health, as they reduce the risk and/or help in the management of chronic diseases. Beans are valuable parts of several dietary recommendations. Saponins, Ξ±-galactosides, phytates, and lectins are currently drawing attention because of their diverse properties, both adverse and beneficial. The aim was to determine the hepatotoxic effect of dry red kidney beans, i.e. Phaseolus vulgaris, on rabbits at 4 g kgβ1, 6 g kgβ1, and 8 g kgβ1 dosing for the period of 30 days. The histopathological examination revealed inflammation of hepatocyte at all three doses along with congestion. The biochemical testing of liver enzymes revealed elevated alanine transaminase (ALT), aspartate transaminase (AST) and gamma-glutamyl transferase (Ξ³-GT). The dose-dependent increase in liver enzymes indicates the hepatotoxic effect of dry red kidney beans, and various studies have demonstrated that lectins are the toxic components responsible for inflammation of body organs
Kajian Pengaruh Adat Istiadat, Religi, dan Alam pada Bangunan Adat, Lembah Kuta Ciamis
Impact ofdevelopment period, building and material grown sophisticated that is in use for building Vernacular Architecture in Indonesian, particulary at theKampung Kuta Ciamis. Furthermore, there is certain factors that affect the building such as custom, religion and nature. That factors have effected form, space and structure. Whichthis Factors have been tradition for generation were maintained. Therefore, in this study has been observe for building to find out the factors dominant. Used esplorative,qualitative descriptive methodwith motode scoring.With this metode, the result is costume factor has effected for form, space and structure. In this study, the conclution is costume factor is the major factor at house of Kampung Adat Kuta. Seen from the result obtained from research traditional building of Kampung Kuta, still have Vernacular Architectural value
Invariant solutions of the supersymmetric sine-Gordon equation
A comprehensive symmetry analysis of the N=1 supersymmetric sine-Gordon
equation is performed. Two different forms of the supersymmetric system are
considered. We begin by studying a system of partial differential equations
corresponding to the coefficients of the various powers of the anticommuting
independent variables. Next, we consider the super-sine-Gordon equation
expressed in terms of a bosonic superfield involving anticommuting independent
variables.
In each case, a Lie (super)algebra of symmetries is determined and a
classification of all subgroups having generic orbits of codimension 1 in the
space of independent variables is performed. The method of symmetry reduction
is systematically applied in order to derive invariant solutions of the
supersymmetric model. Several types of algebraic, hyperbolic and doubly
periodic solutions are obtained in explicit form.Comment: 27 pages, major revision, the published versio
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