Creep Tension Tests on Hastelloy Alloy X Bar, Predicting its Behavior and Applying the Data in a Design Problem

Creep is a continuing deformation at elevated temperatures under constant stress. Creep data are important in the design of many machine members subjected to high temperatures. Examples of these would be steam and gas turbine components, thermal cracking equipment in oil refineries, jet air-craft, missiles, rockets and mobile reactors. The second law of thermodynamics shows us that the efficiency of an ideal heat engine can be increased by increasing the temperature of the working fluid. The optimum strength-to-weight ratio is an essential requirement in aircraft structural design. But all these facts bring us the problem of higher creep rates for the same stresses. In some applications, the permissible creep deformations are critical, e.g. Allowance for creep is important in turbine blades for proper operation to maintain small clearances between the moving and stationary parts and in others no significance. The creep phenomenon has been known for the last 80 years, but knowledge of the phenomenon has advanced rapidly since World War II, due to more demand for high temperature materials, resulting in today’s successful new alloys. Creep deformation can be determined in the laboratory with a testing machine but conducting such tests for the entire life of the machine element is impracticable. As we know, the operating characteristics of an original model can be obtained from a small scale model by means of dimensional analysis. The idea was to have lead creep curves similar to those of the original material in order to obtain direct extrapolation from low temperature lead tests to operating conditions. Cases occur where parts are subjected to combine bending and direct load. For example, turbine blades are subjected to a b3ending action due to the transverse loading applied by the steam, and to a direct load due to centrifugal force. Under creep conditions, parts subjected to this combined straining action when the predominant action is bending are much more favorably stressed than would be the case if the material were elastic and when the predominant action is direct load the stress conditions will approach those for elastic condition. So analyzing the forces acting on a machine element is an important step in a design problem

Isolation, phenotype, and allostimulatory activity of mouse liver dendritic cells

Donor liver-derived dendritic cells (DC) have recently been identified within various lymphoid and nonlymphoid tissues of organ allograft recipients, including nonimmunosuppressed mice transplanted with and permanently accepting major histocompatibility complex (MHC)-disparate hepatic allografts. These findings have raised questions about the basis of the tolerogenicity of the liver—and, in particular, about the properties of liver-derived DC. To study further the structure, immunophenotype and allostimu-latory activity of leukocytes resident in normal mouse (B10.BR; H-2k, I-Ek) liver, a procedure was developed to maximize the yield of viable, nonparenchymal cells (NPC) obtained following collagenase digestion of perfused liver fragments and density centrifugation (Per-coll). These cells comprised populations expressing lymphoid and myeloid cell surface antigens. As compared with spleen cells, they proved good allostimula-tors of naive (BIO; H-2b, I-E") splenic T cells when tested in primary mixed leukocyte reactions (MLR). After overnight (18-hr) incubation of the NPC, enrichment for transiently adherent, low-density (LD) cells on metrizamide gradients permitted the recovery of low numbers of cells (approx. 2-5 × 105 per liver), many of which displayed distinct DC morphology. Flow cytometric analysis revealed that these cells were CD3-, CD4-, CD8-, and B220-, but strongly expressed CD45 (leukocyte-common antigen), and mild-to-moderate levels of CD lib, heat-stable antigen, and CD44. The cells also expressed moderate intensity of NLDC 145 but not 33D1, DC restricted markers which have been shown to be differentially expressed on mouse DC isolated from various organs. This DC-enriched population was more strongly MHC class II(I-Ek)+ than NPC, as determined by immunocytochemistry and flow cytometry and exhibited much more potent allo-stimulatory activity for naive T cells. These findings demonstrate that freshly isolated murine liver NPC, and perhaps their counterparts in situ, exhibit allo-stimulatory activity that is enhanced in the nonadherent, low-density (DC-enriched) fraction after overnight culture. They further suggest that the © 1994 by Williams and Wilkins

Acreage response and produdion supply functions for soybeans

This study deals with response and supply functions for soybean acreage and production. The analysis relates to the nation, to major producing regions and to states important in soybean production. Supply relationships are estimated for the original values of observations and for logarithmic transformations. The time series data used cover the period 1929-1963. Several regression models are used in estimation

Antihepatotoxic effect of Elephantopus scaber L. on carbon tetrachloride-induced hepatotoxicity in rats

Elephantopus scaber was used in folk medicine in several countries to treat different diseases. Liver diseases are major World wise health Problems. The Present aim of the study was evaluate The Antihepatotoxic effects of different fractions of Elephantopus scaber against Carbon tetrachloride (CCl4) induced hepatic damage in Rats. All the fractions were given orally in different doses (125mg/kg, 250mg/kg, 500mg/kg). The Antihepatotoxic effect was assessed by measuring serum parameters like  aspertate transaminase (AST), alanine transaminase (ALT), Alkaline Phospatase (ALP) and total bilurubin.  All the fractions of Elephantopus scaber showed Antihepatotoxic effect.The ethanol fraction was shows significant percentage protection than compared to other fractions. Therefore, our study supports the isolation and use of active constituents from Ethanol fraction of Elephantopus scaber in treating of liver disease

Fisherwomen’s Knowledge, Aptitude and Practice (KAP) of alternate income generating activities: A case study in AP

Fisheries sector in India contributes to over Rs.6.000 crores of foreign exchange. It employs about three million people living In 3638 fishing villages in marine capture fisheries and related activities. Thus the sector serves as an important source of employment income generation and a comparatively cheaper source of protein

Electronic phase separation in the rare earth manganates, (La1-xLnx)0.7Ca0.3MnO3 (Ln = Nd, Gd and Y)

All the three series of manganates showsaturation magnetization characteristic of ferromagnetism, with the ferromagnetic Tc decreasing with increasing in x up to a critical value of x, xc (xc = 0.6, 0.3, 0.2 respectively for Nd, Gd, Y). For x > xc, the magnetic moments are considerably smaller showing a small increase around TM, the value of TM decreasing slightly with increase in x or decrease in . The ferromagnetic compositions (x xc) show insulator-metal (IM) transitions, while the compositions with x > xc are insulating. The magnetic and electrical resistivity behavior of these manganates is consistent with the occurrence of phase separation in the compositions around xc, corresponding to a critical average radius of the A-site cation, , of 1.18 A. Both Tc and TIM increase linearly when < rA > > or x xc as expected of a homogenous ferromagnetic phase. Both Tc and TM decrease linearly with the A-site cation size disorder at the A-site as measured by the variance s2. Thus, an increase in s2 favors the insulating AFM state. Percolative conduction is observed in the compositions with > < rAc >. Electron transport properties in the insulating regime for x > xc conforms to the variable range hopping mechanism. More interestingly, when x > xc, the real part of dielectric constant (e') reaches a high value (104-106) at ordinary temperatures dropping to a very small (~500) value below a certain temperature, the value of which decreases with decreasing frequency.Comment: 27 pages; 11 figures, Submitted to J.Phys:Condens Matte

FORMULATION AND EVALUATION OF ORODISPERSIBLE TABLETS OF DONEPEZIL HYDROCHLORIDE

Objective: The present study was aimed to develop the formulation and in vitro evaluation of Orodispersible tablets by wet granulation method using Donepezil HCl as a model drug to enhance patient compliance. Methods: In the wet granulation method, a mixture of microcrystalline cellulose and hydroxypropyl methylcellulose were used along with superdisintegrants, i.e., croscarmellose sodium and crospovidone. The prepared granules were subjected to both pre and post-compression evaluation parameters including; FTIR spectroscopy, micromeritics properties, tablet weight variation, hardness, friability, drug content, disintegration time and in vitro drug release. Results: FTIR studies indicated that there was nointeraction between the drug and the excipients used. The formulation containing high concentration of crospovidone and mixture as the best formulation F2 based on in vitro drug release characteristics of tablet formulation. Conclusion: The results of this work suggested that orodispersible tablets of Donepezil hydrochloride with rapid disintegration time, fast drug release and good hardness can be efficiently and successfully formulated by wet granulation method

Representations of Double Affine Lie algebras

We study representations of the double affine Lie algebra associated to a simple Lie algebra. We construct a family of indecomposable integrable representations and identify their irreducible quotients. We also give a condition for the indecomposable modules to be irreducible, this is analogous to a result in the representation theory of quantum affine algebras. Finally, in the last section of the paper, we show, by using the notion of fusion product, that our modules are generically reducible