Pollution error in the h-version of the finite-element method and the local quality of a-posteriori error estimators

Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to [email protected], referencing the URI of the item.Includes bibliographical references.In this work we study the pollution-error in the h-version of the finite element method and its effect on the local quality of a-posteriori error estimators. We show that the pollution-effect in an interior subdomain depends on the relationship between the mesh inside and outside the subdomain and the smoothness of the exact solution. We also demonstrate that it is possible to guarantee the quality of local error-estimators in the interior of a finite-element mesh-subdomain of interest by employing meshes which are sufficiently refined outside the subdomain

Transient effect of soil thermal diffusivity on performance of EATHE system

This paper presents effect of thermo-physical properties of soil on performance of an Earth Air Tunnel Heat Exchanger (EATHE). The analysis has been carried out using a validated three-dimensional, transient numerical model for three different types of soil. The governing equations, based on the k–ε model and energy equation were used to describe the turbulence and heat transfer phenomena, are solved by using finite volume method. Comparisons were made in terms of temperature drop, heat transfer rate and COP of the EATHE system by operating it continuously for 12 h duration. The study reveals that each soil exhibits different rate of heat dissipation and thermal saturation over a period of continuous operation, which adversely affects the performance of EATHE. Dissipation of heat from the EATHE pipes to its surrounding soil and subsequently to the outer subsoil region is mainly found to be depending upon the thermal conductivity of soil; even of their thermal diffusivity is of different order

Prevalence of HIV/AIDS and prediction of future trends in north-west region of India: A six-year ICTC-based study

<b>Background:</b> The study was conducted to analyze previous six-year prevalence data of HIV infection in the Northwest region of India and predict future trends for a couple of years. <b> Objectives:</b> The study was conducted to aid SACS and NACO to plan and arrange resources for the future scenario. <b> Materials and Methods:</b> All the attendees of ICTC, Jaipur, from January 2002 to December 2007 were included and variables like age, sex, marital status, occupation, place of residence, pattern of risk behavior and HIV serostatus were studied. As per the strategy and policy prescribed by NACO, tests (E/R/S) were performed on the serum samples. Data was collected; compiled and analyzed using standard statistical methods. Future trends of HIV-prevalence in north-west India were anticipated. <b> Results:</b> The overall positivity rates among attendees of ICTC, were found to be 12.2&#x0025; (386/3161), 11.8&#x0025; (519/4381), 11.1&#x0025; (649/5867), 13&#x0025; (908/6983), 14&#x0025; (1385/9911) and 17.34&#x0025; (1756/10133) in the years 2002, 2003, 2004, 2005, 2006 and 2007 respectively. Future trends for the next couple of years depict further increase in prevalence without any plateau. <b> Conclusion:</b> Epidemiological studies should be carried out in various settings to understand the role and complex relations of innumerable behavioral, social and demographic factors, which will help, interrupt and control the transmission of HIV/ AIDS