The digital simulation of a turbo-charged diesel engine

A mathematical simulation of a six cylinder four stroke water cooled diesel engine is described and then used to study the changes in performance caused by variations of engine paramters and operating conditions. The results are discussed with reference to the mathematical model employed and the physical system. A limited study, to demonstrate the applicability of the simulation, considers the optimisation of a variable geometry system to achieve a performance target

Guest Editorial: Nonlinear Optimization of Communication Systems

Linear programming and other classical optimization techniques have found important applications in communication systems for many decades. Recently, there has been a surge in research activities that utilize the latest developments in nonlinear optimization to tackle a much wider scope of work in the analysis and design of communication systems. These activities involve every “layer” of the protocol stack and the principles of layered network architecture itself, and have made intellectual and practical impacts significantly beyond the established frameworks of optimization of communication systems in the early 1990s. These recent results are driven by new demands in the areas of communications and networking, as well as new tools emerging from optimization theory. Such tools include the powerful theories and highly efficient computational algorithms for nonlinear convex optimization, together with global solution methods and relaxation techniques for nonconvex optimization

The public utility contract exception in Indian law: awarding damages without proof of actual loss

This post analyses a new trend emerging from case laws in the Supreme Court of India allowing parties to claim damages without proof of actual loss in public utility Contracts on the basis that any delay in implementing them affects the public at large, a loss that can neither be computed nor proven. Jeet H. Shroff and Ifrah Shaikh argue that such decisions add an element of public interest to the law of damages in India, which falls firmly within the realm of private law. In doing so, the decisions re-draw the boundaries between public and private law, and are likely to affect larger issues of public policy in India

Likelihood of rising stroke in populace of western India: a case control study

Background: Cerebrovascular accident (Stroke) is a non-communicable disease of increasing importance. According to the World Health Organization, 15 million people suffer from stroke worldwide each year. The National Commission on Macroeconomics and Health, India, has estimated 1.67 million stroke cases in India. Due to the increasing prevalence of hypertension, diabetes, dyslipidemia, fast changing lifestyle and re-structuring of population, stroke will be an epidemic in India in the days to come. Few studies have been carried out in developing countries like India. So, this study intended to know the presentation in addition to risk factors, patterns of warning signs and symptoms of stroke in patients admitted to state tertiary care Hospital. Methods: Assuming the power ratio of the number of controls same as numbers of cases specifying values for two sided confidence level 95% and odd ratio 2.15 which was the minimum risk factor in previous study was taken to calculate sample size. Results: After studying of 148 cases of stroke and same controls, we conclude that most common type of stroke is ischemic stroke followed by haemorrhagic stroke. After multivariate analysis we found, modifiable risk factors were mainly mental stress, active and passive smoking, hypertension and obesity. Conclusions: Due to the sheer magnitude, devastating consequences and residual sequelae of the stroke, early intervention in the form of patient education, modification of the lifestyle, non-pharmacological and pharmacological interventions for modifiable risk factors should be an integral aspect of patient care

Assessing Individual-level Factors Supporting Student Intrinsic Motivation in Online Discussions: A Qualitative Study

Research has established that intrinsic motivation has a positive effect on learning and academic achievement. However, little is known about the impact of different technology-supported learning activities on student intrinsic motivation or whether such learning activities significantly enhance student intrinsic motivation compared to traditional classroom environments without technological support. In order to investigate the phenomenon of intrinsic motivation in technology-supported learning environments, this paper examines factors that support individual student intrinsic motivation in online discussions. A research model is presented based on research into motivation, and the specific areas of self-determination and curiosity provide a framework for the model. A qualitative research methodology is used to validate the model. Results from the study indicate that five factors; perceived competence, perceived challenge, feedback, perceived interest and perceived curiosity, were strongly supported, with partial support for the construct of perceived choice

Effects of kink and flexible hinge defects on mechanical responses of short double stranded DNA molecules

We predict various detectable mechanical responses to the presence of local DNA defects which are defined as short DNA segments exhibiting mechanical properties obviously different from the 50 nm persistence length based semiflexible polymer model. The defects discussed are kinks and flexible hinges either permanently fixed on DNA or thermally excited. Their effects on extension shift, the effective persistence length, the end-to-end distance distribution, and the cyclization probability are computed using a transfer-matrix method. Our predictions will be useful in future experimental designs to study DNA nicks or mismatch base pairs, mechanics of specific DNA sequences, and specific DNA-protein interaction using magnetic tweezer, fluorescence resonance energy transfer or plasmon resonance technique, and the traditional biochemistry cyclization probability measurements.Comment: 9 pages with 9 figures. Theoretical calculation based on transfer matrix. Minor updates, a new figure and more discussions are adde

MR imaging for diagnostic evaluation of encephalopathy in the newborn.

Magnetic resonance (MR) imaging is used with increasing frequency to evaluate the neonatal brain because it can provide important diagnostic and prognostic information that is needed for optimal treatment and appropriate counseling. Special care must be taken in preparing encephalopathic neonates for an MR study, transporting them from the intensive care unit, monitoring their vital signs, and optimizing MR sequences and protocols. Moreover, to accurately interpret the findings, specific knowledge is needed about the normal MR imaging appearances of the physiologic processes of myelination, cell migration, and sulcation, as well as patterns of injury, in the neonatal brain at various stages of gestational development. Hypoxic-ischemic injury, the most common cause of neonatal encephalopathy, has characteristic appearances that depend on the severity and duration of the insult as well as the stage of brain development. Diffusion-weighted MR imaging and MR spectroscopy depict abnormalities earlier than do conventional MR imaging sequences. However, diffusion-weighted imaging, if performed in the first 24 hours after the insult, might lead to underestimation of the extent of injury. When the MR findings are atypical, the differential diagnosis of neonatal encephalopathy also should include congenital and metabolic disorders and infectious diseases. Despite recent advances in the MR imaging-based characterization of these conditions, the clinical history must be borne in mind to achieve an accurate diagnosis

Management Forecast Quality and Capital Investment Decisions

Corporate investment decisions require managers to forecast expected future cash flows from potential investments. Although these forecasts are a critical component of successful investing, they are not directly observable by external stakeholders. In this study, we investigate whether the quality of managers' externally reported earnings forecasts can be used to infer the quality of their corporate investment decisions. Relying on the intuition that managers draw on similar skills when generating external earnings forecasts and internal payoff forecasts for their investment decisions, we predict that managers with higher quality external earnings forecasts make better investment decisions. Consistent with our prediction, we find that forecasting quality is positively associated with the quality of both acquisition and capital expenditure decisions. Our evidence suggests that externally observed forecasting quality can be used to infer the quality of capital budgeting decisions within firms

Infant Mortality Trends Among Georgia Residents, 1995-2003: Targeting Healthy People’s 2010 Goals

Population-based trends in infant mortality among Georgia Residents between 1995 and 2003 were assessed on characteristics such as race, birth weight, neonatal and post-neonatal periods, and cause of death. A statistical analysis was conducted to show that the Georgia infant mortality rate (IMR) remained constant throughout the study period and averaged 8.67 per 1,000 live births. The analysis revealed racial disparities, with an IMR ranging from 6.03 in white infants to 13.76 in black infants, with less than one percent (0.86%) change, on average, among the differences between black and white mortality rates across the nine-year period. The disparities were also evident in infants with low birth weight (LBW) and very low birth weight (VLBW). Black infants born with LBW (12.9%) and VLBW (9.98%) have more than twice the rate of infant mortality compared to white infants born with LBW (6.64%) and VLBW (1.12%). Mortality in the neonatal period accounted for more than half (67.96%) of all infant deaths and exhibited considerable ethnic differences. Among all groups, black male neonates (10.7) have the highest mortality rates. The average neonatal mortality rate across the entire study period is 5.89 (SD=0.20); the average postneonatal mortality rate across the entire study period is 2.78 (SD=0.22). The five leading causes of death among Georgian infants in descending order were: birth defects, prematurity and low birth weight, Sudden Unexplained Infant Deaths (SUID), other perinatal conditions and respiratory conditions with racial differences in the ordering