NUMERICAL INVESTIGATION OF A SCRAM JET USING DNS METHOD

Heat Transfer is the science that predicts the energy transfer across the materials as result of the temperature difference. It is well known that there are three fundamental modes of heat transfer namely Conduction, Convection and Radiation. It has become exceedingly important for an engineer to possess a clear understanding of the principles of heat transfer and its applications to a large number of problems. Engineers are constantly confronted with the need to maximize or minimize the heat transfer rates and to maintain the integrity of materials under conditions of extreme temperatures. In order to determine the temperature distribution across the walls of combustion chambers and nozzles that possess hot gases, heat transfer coefficient is an important parameter to be evaluated in heat transfer analysis as the heat transfer in the engine components takes place mainly by convection from the hot gases to the surrounding walls.  It is necessary to combine equations of motion with those of heat conduction. Therefore the need for fluid flow analysis becomes evident while solving heat transfer problems, especially when the heat source is in the form of high temperature fluids as in the case of Propulsion systems. In recent years there has been a vast increase in interest in supersonic combustion in connection with flight propulsion. In the typical propulsion unit,   propellants enter the combustion chamber, gets ignited and escapes through the nozzle at very high speeds which are supersonic in nature. Because of these gases escaping through the nozzle the rocket receives momentum in the opposite direction according to Newton’s Third Law of Motion. The present work deals with the heat transfer analysis of the uncooled -combustion chamber. The study includes the temperature distributions across the thickness of the combustion chamber and estimation of the maximum time upto which the system can withstand the temperature under given operating conditions. A VB script code is developed to obtain the temperature distributions with respect to the time across the walls of the combustion chamber. Based on the heat transfer analysis, the maximum permissible test durations are estimated for the present uncooled combustion chamber of different materials with various configurations.. In order to increase the test duration, a cooling system is proposed for further studies

Regression based predictor for p53 transactivation

<p>Abstract</p> <p>Background</p> <p>The p53 protein is a master regulator that controls the transcription of many genes in various pathways in response to a variety of stress signals. The extent of this regulation depends in part on the binding affinity of p53 to its response elements (REs). Traditional profile scores for p53 based on position weight matrices (PWM) are only a weak indicator of binding affinity because the level of binding also depends on various other factors such as interaction between the nucleotides and, in case of p53-REs, the extent of the spacer between the dimers.</p> <p>Results</p> <p>In the current study we introduce a novel <it>in-silico </it>predictor for p53-RE transactivation capability based on a combination of multidimensional scaling and multinomial logistic regression. Experimentally validated known p53-REs along with their transactivation capabilities are used for training. Through cross-validation studies we show that our method outperforms other existing methods. To demonstrate the utility of this method we (a) rank putative p53-REs of target genes and target microRNAs based on the predicted transactivation capability and (b) study the implication of polymorphisms overlapping p53-RE on its transactivation capability.</p> <p>Conclusion</p> <p>Taking into account both nucleotide interactions and the spacer length of p53-RE, we have created a novel <it>in-silico </it>regression-based transactivation capability predictor for p53-REs and used it to analyze validated and novel p53-REs and to predict the impact of SNPs overlapping these elements.</p

Richardson extrapolation technique on a modified graded mesh for singularly perturbed parabolic convection-diffusion problems

In this paper, we focus on investigating a post-processing technique de-signed for one-dimensional singularly perturbed parabolic convection-diffusion problems that demonstrate a regular boundary layer. We use a back-ward Euler numerical approach for time derivatives with uniform mesh in the temporal direction, and a simple upwind scheme is used for spa-tial derivatives with modified graded mesh in the spatial direction. In this study, we demonstrate the effectiveness of the Richardson extrapola-tion technique in enhancing the ε-uniform accuracy of simple upwinding within the discrete supremum norm, as evidenced by an improvement from O(N −1 ln(1/ε) + △θ) to O(N −2 ln2(1/ε) + △θ2). Furthermore, to validate the theoretical findings, computational experiments are conducted for two test examples by applying the proposed technique

Morphology dependent electrical property of chitosan film and modeling by fractal theory

The present study proposes a more general fractal approach-iterated function system (IFS) model for explaining the morphology of a biopolymer like chitosan dissolved in various organic acids and forming film and compared with the experimental results through multifractal approach. The bio polymer like chitosan has been dissolved in various organic acids like formic, acetic, adipic and the film of the same also have been formed through solution casting technique. The morphology of the prepared films have been obtained from scanning electron microscope (SEM) and the electrical impedance from LCR HIOKI Hi-Tester. The IFS theory is used to generate the morphology of chitosan film dissolved in various organic acids of various concentrations. In order to draw the similarity between morphological structure of experimentally obtained self-similar property of chitosan dissolved in various acids of different concentration of chitosan and the same has been generated by random iterated algorithm. The generalized fractal dimensions are estimated and compared with the electrical property like impedance which follows the same trend. Further, the growth of bacterial colonies and its self-similar structure has been generated by the same method. Hence it is inferred that our model is a more general model for the generation of self-similar property exhibited by nature

Clinical Study on Dosha-Based Combinations in Essential Hypertension

Hypertension (HT) is one of the most vital modifiable risk factors for coronary heart disease, stroke, congestive heart failure, chronic kidney disease, and peripheral vascular disease. Data from HT trials indicate that most subjects need combination therapy to achieve sufficient BP control and in only 50% of trials, this goal was achieved. Addressing the contributory factors is the need of the hour rather than controlling blood pressure (BP) level only. Here the Ayurvedic drugs are having a definite scope in the management. HT may be considered as tridoshaja vyadhi with Vatha dominance with affection of the rasa and raktha dhatus. Ayurgenomics is having a crucial role in explaining how drugs can be used more effectively by targeting them on individuals of particular Prakriti.. The unique method of administering the drug based on the prakriti and dosha in any clinical condition so as to enhance the effect is termed personalized medicine and based on the judgment that the doshahara drugs when added to vyadhihara drug enhances its efficacy potential. Sarpagandha was added with brihat panchamoola, trina panchamoola and triphala in Vatha, Pitta and Kapha groups respectively. Methodology: In the multicentric study, 50 subjects each of Vatha, Pitta and Kapha prakrithi, satisfying the diagnostic criteria were administered with the drug, 6 gm twice daily after food, as per the dosha status for 45 days with BP assessments on 0th day, 15th, 30th, 45th and 60th day. Repeated Measures ANOVA was done for analysis. Result: The mean score reduced throughout the assessments and was significant at 0.01% level indicating the influence on prakriti in the outcome

Psychological Understanding of Hypertension- Ayurvedic Perspective

Hypertension is the condition where blood pressure is elevated chronically. It has multiple factors such as genetic, environmental and life style. The Stress which is usually having a role in the scenario, usually is left unaddressed and the condition is managed only with the anti-hypertensives. Discussion of hypertension in the perspective of Ayurveda is a debatable area till now. Hṛdaya considered to be the root place of hypertension, has its origin from Rakta and Kapha in the normal state of development. Being abode for consciousness, senses, mind, soul etc. it is to be taken as a conglomeration of somatic, psychic as well as spiritual entities. Śṛama, Mōha, Mūṛchā which is exhibited in the circumstances of alteration of ojus such as Ōjakṣaya/ Ōjōvyāpath, can be observed in elevated blood pressure situations. Tridōṣa also contributes a major role in the development of hypertension through their dysfunctions. While considering the Nidāna paṉcaka of stress associated hypertension, negative emotions such as fear, anxiety, anger and excessive thoughts are always going in parallel to the unhealthy dietary habits and sedentary life style. A multidisciplinary approach may be ideal and quite useful in such situations. Ayurvedic principles along with the practices of yoga can improve positive health in this intricate scenario