Stress Intensity Factor using Finite Element Analysis in Rectangular Orthotropic Composite Annular Disk

The quadratic isoparametric elements which embody the inverse squareroot singularity were used to determine the stress intensity factor in an annular disk made of Boron-Epoxy composite material. The displacements and stresses were determined in a rectangular orthotropic composite annular disk using isoparametric finite elements. The singularity in the strain field was provided by means of 8-noded isoparametric elements (4-nodes at the four corners and four mid-side nodes each at l/4th distance from the edge). The results were obtained for various material properties and fibre orientation. The geometry of the annular disk was reported when subjected to a boundary radial and tangential. The r singularity was provided at the boundary of the circular hole and the rest of the annular disk was modelled with ordinary isoparametric elements. The apparent stress intensity factor (K/sub I/=) was computed from the stress data near the circular hole, when it was subjected to uniform tension. A curve was drawn for apparent stress intensity factor versus the distance from the crack edge and was extrapolated to r = 0, the actual stress intensity factor was found on the y-axis

Analysis of Orthogonal Cutting of Aluminium-based Composites

A turning test on aluminium-based metal-matrix composites (MMCs) (aluminium-30% silicon carbide) was performed with K-20 carbide tool material and wear patterns and the wear land growth rates were analysed to evaluate the wear characteristics and to classify the relationship between the physical (mechanical) properties and the flank wear of cutting tools. The study was also extended to the machining aspects and the width of cuts on MMCs and the influence of various cutting parameters. The experiments were conducted to measure the temperature along the cutting tool edge using thermocouple at various cutting speeds, and depth of cuts, keeping the feed rate constant while turning with K-20 carbide cutting tool. The finite-element method was used to simulate the orthogonal cutting of aluminium-based MMCs. The heat generation at the chip-tool interface, frictional heat generation at the tool flank, and the heat generation at the work tool interface were calculated analytically and imposed as boundary conditions. The analysis of the steady-state heat transfer was carried out and the temperature distribution at cutting edge, shear zone, and interface regions have been reported

A rare case of a gigantic myxoid liposarcoma of vulva: case report

Vulval malignancies per se are very rare and a liposarcoma in this location is rarer still. The literature consists only of case reports of patients, often with a very limited follow up. We present a rare case of a young 30 year old unmarried nulliparous woman presenting with a giant vulval mass of 30×20 cm and weighing nearly 6 kilograms. Ultrasonography, Computed Tomography, Magnetic Resonance Imaging and biopsy were done. Local resection with adjuvant radiotherapy was given. Histopathology was suggestive of myxoid liposarcoma and the patient is presently recurrence free with over 8 years of follow up. Though rare, myxoid liposarcoma should be kept in differential diagnosis of vulval soft tissue mass. Management includes a combination of surgery and radiation. Excision of lymph nodes is not recommended. Strict prolonged follow up for recurrence or metastasis is mandatory, and any new complaints should be addressed promptly. This is particularly true in the setting of liposarcoma, which may exhibit unusual patterns of spread and recurrence

Trions in a periodic potential

The group-theoretical classification of trion states is presented. It is based on considerations of products of irreducible representations of the 2D translation group. For a given BvK period N degeneracy of obtained states is N^2. Trions consist of two identical particles so the symmetrization of states with respect to particles transposition is considered. Completely antisymmetric states can be constructed by introducing antisymmetric spin functions. Two symmetry adapted bases are considered. The third possibility is postponed for the further investigations.Comment: revtex, 5 p., sub. to Physica

Genetically Encoded Photo-cross-linkers Map the Binding Site of an Allosteric Drug on a G Protein-Coupled Receptor

G protein-coupled receptors (GPCRs) are dynamic membrane proteins that bind extracellular molecules to transduce signals. Although GPCRs represent the largest class of therapeutic targets, only a small percentage of their ligand-binding sites are precisely defined. Here we describe the novel application of targeted photo-cross-linking using unnatural amino acids to obtain structural information about the allosteric binding site of a small molecule drug, the CCR5-targeted HIV-1 co-receptor blocker maraviroc

Cost analysis of a coal-fired power plant using the NPV method

The present study investigates the impact of various factors affecting coal-fired power plant economics of 210 MW subcritical unit situated in north India for electricity generation. In this paper, the cost data of various units of thermal power plant in terms of power output capacity have been fitted using power law with the help of the data collected from a literature search. To have a realistic estimate of primary components or equipment, it is necessary to include the latest cost of these components. The cost analysis of the plant was carried out on the basis of total capital investment, operating cost and revenue. The total capital investment includes the total direct plant cost and total indirect plant cost. Total direct plant cost involves the cost of equipment (i.e. boiler, steam turbine, condenser, generator and auxiliary equipment including condensate extraction pump, feed water pump, etc.) and other costs associated with piping, electrical, civil works, direct installation cost, auxiliary services, instrumentation and controls, and site preparation. The total indirect plant cost includes the cost of engineering and set-up. The net present value method was adopted for the present study. The work presented in this paper is an endeavour to study the influence of some of the important parameters on the lifetime costs of a coal-fired power plant. For this purpose, parametric study with and without escalation rates for a period of 35 years plant life was evaluated. The results predicted that plant life, interest rate and the escalation rate were observed to be very sensitive on plant economics in comparison to other factors under study

ALLELOPATHIC IMPACT OF ESSENTIAL OIL OF TAGETES MINUTA ON COMMON AGRICULTURAL AND WASTELAND WEEDS

ABSTRACTObjective: Tagetes minuta (Family Asteraceae) is an aromatic plant possessing volatile essential oil.  Its oil finds extensive use in flavor and perfume industry. T. minuta oil also possess medicinal and insecticidal properties as antiheminthic, nematicidal, bactericidal, antiviral, fngicidal and insecticidal. The plant has been explored for herbicidal potential in very few reports. The aim of present study is to find out its allelopathic potential against common wasteland and agricultural weeds.Material & Methods: Various agricultural and wasteland weeds were selected for laboratory growth studies. Oil was applied in solution form using an emulsifier.Results: Growth of all test weeds was inhibited by T. minuta oil; however, effect was maximum in Amaranthus tricolor with complete inhibition at 1µl/ml and E. cruss-galli was least affected with complete inhibition at 5µl/ml concentration of T. minuta oil.Conclusion: T. minuta oil offers great potential for effective weed management in agricultural as well as wasteland areas. Keyowrds: Tagetes minuta, essential oil, allelopathy, solution form, wasteland, agricultural, weed

Study of development and utilization of a multipurpose atmospheric corrosion sensor

There has been a critical need for analyzing various aspects of atmospheric corrosion and for the development of atmospheric corrosion microsensors. The project work has involved the following activities: (1) making of multielectrode corrosion monitors on dielectric substrates; (2) testing them in the laboratory for functional characteristics; (3) preparing a report on the state of the art of atmospheric corrosion sensor development around the world; and (4) corrosion testing of electrochemical changes of sensor specimens and related fog testing. The study included work on the subject of development and utilization of a multipurpose atmospheric corrosion sensor and this report is the annual report on work carried out on this research project. This has included studies on the development of sensors of two designs, stage 1 and stage 2, and with glass and alumina substrate, experimentation and development and characterization of the coating uniformity, aspects of corrosion monitoring, literature search on the corrosion sensors and their development. A state of the art report on atmospheric corrosion sensor development was prepared and submitted

Prognostic indicators and patterns of renal recovery in patients requiring hemodialysis for acute kidney injury

Background: The outcome of patients with acute kidney injury (AKI) is highly variable. Patients who receive renal replacement therapy (RRT) for similar diseases may recover differently. The factors that operate in each patient may alter the prognosis and outcome. Aims: Our study aims at identification of prognostic factors influencing recovery in patients who required hemodialysis for AKI. Material and Methods: Patients admitted in different ICUs with AKI who underwent hemodialysis in a tertiary care hospital over a three year period were included in the study. Time from day one of disease to first dialysis, hematological and biochemical parameters were noted. Patients were grouped based on the time taken for recovery of renal function following hemodialysis into group A (<2 weeks) and group B (>2 weeks). Studied parameters have been statistically analyzed to find any significant association with recovery time. Results: Out of 63 patients, 9 progressed to chronic kidney disease. In the remaining 54, Group A comprised 31 and group B 23. Out of all the factors studied, serum creatinine (7.0±1.3 vs 8.4±3.8; P=0.018), S. bicarbonate (21.7±2.8 vs 19.7±3.8; P=0.03), pH at admission (7.25±0.13 vs 7.1±0.19; P=0.048); number of hemodialysis sessions (3.5 ±1.5 vs 5±2.4; P=0.016) and time lag from day one of disease to first hemodialysis (8.6 ± 3.6 vs 11.5±5.9; P=0.007) showed significant association with recovery time. Conclusion: Recovery following AKI is influenced by factors liked delayed presentation, late initiation of hemodialysis, low pH and low bicarbonate which can predict delayed renal recovery following hemodialysis