Approximating the multi-level bottleneck assignment problem.

We consider the multi-level bottleneck assignment problem (MBA). This problem is described in the recent book 'Assignment Problems' by Burkard et al. (2009) on pages 188-189. One of the applications described there concerns bus driver scheduling.We view the problem as a special case of a bottleneck m-dimensional multi-index assignment problem. We give approximation algorithms and inapproximability results, depending upon the completeness of the underlying graph. Keywords: bottleneck problem; multidimensional assignment; approximation; computational complexity; efficient algorithm.Bottleneck problem; Multidimensional assignment; Approximation; Computational complexity; Efficient algorithm;

Advanced flamelet modelling of turbulent non-premixed and partially premixed combustion

Current work focuses on the development and performance evaluation of advanced flamelet models for turbulent non-premixed and partially premixed combustion in RANS and large eddy simulation (LES) based modelling. A RANS-based combustion modelling strategy which has the ability to capture the detailed structure of turbulent non-premixed flames, including the pollutant NO, and account for the effects of radiation heat loss and transient evolution of NO, has been developed and incorporated into the in-house RANS code. The strategy employs an 'enthalpy defect'-based non-adiabatic flamelet model in conjunction with steady or unsteady nonadiabatic flamelets based NO submodels. [Continues.

Adaptive Mean Value Function Based Quality Assessment of Software Reliable Growth Models

Software growth models aims for reliability of the application over a period of time. Assessment of such models is of great interest since many faults arises with the models during the operation over a span of time. In this paper a adaptive mean value function based testing and estimation of the parameters were discussed. The proposed approach is also compared against the conventional testing approaches and found that the proposed method able to detect the fault under different scenario and proves to give better performance under a constrained environment. Keywords: Software reliability, Growth models, testing analysis, Fault detection and correction

Quality Assessment of Software Reliability Growth Models

The two main important properties of software components are reliability and robustness. Reliability can be defined as the probability of failure free operation and on the other hand the robustness can be defined as how far the software can be able to with stand for intrusion attacks. In both the cases there should be some metric to evaluate the performance of these properties. In this paper metrics are been described which can be used to assess the quality of performance for these properties within a software reliability growth model. Keywords: Software growth model, reliability, robustness, Quality metrics

Performance of PIXE Technique through a Geochemical Analysis of High Grade Rocks

It has been an argument that some of the elements present in geological material by using PIXE analysis are purely determined or could not be determined at all, due to various reasons including the matrix. It is felt that a systematic investigation needs to be designed and implemented to understand the limitation of PIXE in certain elements. The high-grade rocks selected are analyzed both by PIXE as well as AAS and the results are authenticated by using a USGS reference material, Basalt, studies of literature. It is believed that the accuracy of problematic elements, especially from high grade rock can be improved and the conditions of PIXE can be standardized for various elements under different combinations. The reasons behind the poor performance of Proton Induced X- ray Emission in case of certain elements have been established

Laminar flamelet model prediction of NOx formation in a turbulent bluff-body combustor

A bluff-body combustor, with recirculation zone and simple boundary conditions, is ideal as a compromise for an industrial combustor for validating combustion models. This combustor, however, has proved to be very challenging to the combustion modellers in a number of previous studies. In the present study, an improved prediction has been reported through better representation of turbulence effect by Reynolds stress transport model and extended upstream computational domain. Thermo-chemical properties of the flame have been represented by a laminar flamelet model. A comparison among reduced chemical kinetic mechanism of Peters and detailed mechanisms of GRI 2.11, GRI 3.0, and San Diego has been studied under the laminar flamelet modelling framework. Computed results have been compared against the well-known experimental data of Sydney University bluff-body CH4/H2 flame. Results show that the laminar flamelet model yields very good agreement with measurements for temperature and major species with all the reaction mechanisms. The GRI 2.11 performs better than the other reaction mechanisms in predicting minor species such as OH and pollutant NO. The agreement achieved for NO is particularly encouraging considering the simplified modelling formulation utilized for the kinetically controlled NO formatio

Application of Stability Indicating HPLC Method with UV Detector to the Analysis of Rivaroxaban in Bulk and Tablet Dosage Form

Abstract: A simple and sensitive stability indicating HPLC method is developed for the quantification of rivaroxaban in bulk and tablet dosage form. Chromatographic separation was achieved on an ACE-Ciano column (250 mm x 4.6 mm, 5 μm particle size). The mobile phase consists of 0.1M sodium acetate and methanol (60:40 v/v) and was delivered at a flow rate of 1 mL/min. A UV detector was used for the detection. The rivaroxaban was subjected to stress conditions for the assessment of the stability-indicating nature of the method. The method was validated as per ICH guidelines. The linearity is obtained in the range of 1-120 μg/mL. The limit of detection and quantification values is 0.194 μg/mL and 0.648 μg/mL respectively. The intra and inter-day %RSD values were below 1%. Intra and inter-day accuracies were within 100.10% and 100.40%, respectively. Degradation products resulting from the stress studies have no interfere with the detection of rivaroxaban. The average recovery of rivaroxaban in tablet dosage form was 99.74% with %RSD of 0.421%. The developed method was proved adequate for quantitative determination of rivaroxiban in presence of its degradation products

Effect of prenatal exposure to maternal cortisol and psychological distress on infant development in Bengaluru, southern India: a prospective cohort study.

BACKGROUND: The mental health status of a pregnant woman and its consequent impact on foetal well being is not given much importance compared to the risk imposed by obstetric complications and medical conditions. Maternal psychological distress is a major public health problem and needs timely detection and intervention to prevent any adverse pregnancy outcome. There is ample evidence from literature that justifies the association of prenatal maternal mental stress and elevated cortisol with delayed infant motor and cognitive development; evidence from India being rather limited. The study aim is to prospectively assess the association of maternal psychological distress and cortisol level with motor and cognitive development of the infant. METHODS: A sample of 2612 eligible pregnant women who have been registered for antenatal care at selected public sector hospitals in Bengaluru will be recruited after obtaining written informed consent. They will be assessed for the presence of maternal psychological distress in the form of depression and anxiety using appropriate scales and saliva samples will be collected for cortisol estimation during early, mid and late pregnancy. Follow up visits after delivery will be done on day 10, 3 months, 8 months and 12 months. The Bayley Scales of Infant and Toddler Development [BSID] (Third edition) will be used to measure both motor and mental milestones in terms of Psychomotor Development Index (PDI) and Mental Development Index (MDI). Logistic regression model will be used to determine the association between the exposure variables and outcomes which will be reported as Odd's Ratio (OR) and 95% confidence intervals (CI). DISCUSSION: Our study findings could add to the growing evidence that maternal psychological distress during pregnancy adversely influences growth and development in the offspring and subsequent development of the child. While maternal anxiety and depression can be measured by using self reporting instruments, estimation of maternal endogenous cortisol levels could serve as a biomarker of prenatal psychological stress. Findings from this study could be used to focus upon the burden of mental health problems during pregnancy and to consider steps to scale up prenatal mental health services in health care settings