Numerical Flow Simulation using Star CCM+

The accuracy of numerical simulation of any physical process depends on the technique adopted for the simulation and the software used. Many software i.e., ANSYS, PHONICS, NUMECA, STAR-CCM+, etc. have been developed to solve the governing equations in discretizing the flow domain. Each software has its own capabilities and limitations. In the present work, STAR-CCM+ has been used for numerical simulation in draft tube of hydraulic turbine and result are presented in graphical and tabular form.   Keyword: Elbow draft tube, numerical flow simulation, efficiency, head loss

Factors Associated With Farmers' Participation in Community Listening to Farm Broadcast in Central Region, Nepal

The primary purpose of this study was to determine the relation of some characteristics, selected factors such as demographic communication behaviours, attitude and organizational effectiveness with the level of members' participation in community listening. A secondary purpose was to identify the problems associated with community listening and to find out the farmers' views on the comprehensibility, relevancy and usefulness of farm broadcast programme of the Agricultural In formation Section of the Department of Agriculture, Nepal. The respondents for this study were 105 members of the community listening centres (cue) from nine villages in three selected districts. Data were collected by interviewing the randomly selected respondents in the sample areas. Members' attitudes and perceptions toward cue were measured using 12 items and 6 items Likert-type scale respectively. A total of 12 hypotheses were tested. Pearson product-moment correlation and chi-square were used to test the hypotheses while frequencies and percentages were used for other descriptive analyses. The study revealed that, in general, the level of participation in community listening programme among members of CLC was low. Participation was analyzed with each of the independent variables separately to ascertain the direction and degree of association. The variables such as extension contact, organizational membership, opinion leadership status, message relevancy, attitudes and perceived organizational effectiveness were found to be related positively with the level of participation. Other variables such as age, level of education, family size, farm size and cosmopoliteness were found not significantly related to the level of participation. The results of this study suggest that extension contact, organizational membership, opinion leadership status, message relevancy, attitudes and perceptions are the good indicators of participation

Study of serum lipid profile in Plasmodium falciparum malaria

Background: Malaria is a major public health problem in India with wide-ranging haematological and biochemical alterations. Plasmodium falciparum (P. falciparum) is one of four distinct species of the malaria parasite that afflict humans and pose a threat to public health. Under normal physiological conditions, liver ensures homeostasis of lipid and lipoprotein metabolism.  Therefore, the aim of this study was to assess malaria infection and its association with lipid parameters changes. Hepatocellular damage often associated with severe and acute P. falciparum infections impairs these processes, leading to alteration in plasma lipid profile and lipoprotein patterns. An observation on the nature of dyslipidaemia in confirmed cases of P. falciparum malaria patients with reference to correlation if any that exists between malaria and lipid profile in these patients was performed.Methods: A case-control study was carried out on clinically and laboratory confirmed P. falciparum malaria positive patients attending the outpatient and inpatient department of RIMS Ranchi for a period of six months i.e. from January 2018 to June 2018, 100 participants were enrolled for the present study. 50 participants were P. falciparum malaria confirmed cases and 50 participants were without any clinical or laboratory evidence of malaria served as the control.Results: It revealed that the total cholesterol, HDL and LDL were significantly decreased -(P ≤0.05) while triglyceride and VLDL were not significantly changed in P. falciparum malaria patients (P ≥0.05).Conclusions: It can be concluded that alteration in lipid profile can be an index of severe malaria infection that may leads to poor prognosis, but specificity of malaria infection with lipid changes is questionable and need further studies

Study of incidence and prevalence of hypokalemic periodic paralysis

Background: Hypokalemic periodic paralysis (HPP) is a rare autosomal dominant channelopathy characterised by muscle weakness or paralysis when there is a fall of potassium level in the blood. In individuals with mutation, attack begins during adolescents and most commonly occurs after sleep on awakening, rest after strenuous exercise, high carbohydrate diet and meal with high sodium content. This study was conducted to analyse the age of incidence and prevalence of HPP with various clinical presentations, diagnosis and its effective treatment.Methods: A retrospective analysis of 50 patients of Hypokalemic periodic paralysis was analysed in tertiary care centre “Rajendra institute of medical science” Ranchi, Jharkhand, India, with reference to its clinical presentation, age of incidence and prevalence with laboratory parameters and treatment outcomes.Results: Incidence of attack is more common in men between 26-35 years of age. Sudden onset of flaccid quadriparesis was the most common presentation with history of high carbohydrate diet on the background of strenuous work during summer season. Around 60% had similar history of attacks in the past and most of the patients had serum potassium levels between 2.1-3.0mEq/L. Electrocardiography (ECG) abnormalities associated with hypokalemia had been observed in 90% of patients, and also significant clinical, biochemical changes have been observed as well.Conclusions: Early diagnosis not only helps in definitive management with potassium replacement, but also prevents patient going for life threatening respiratory failure.  Patients recover completely without any clinical sequelae. Therefore, it is imperative for physicians, particularly those working in acute care settings, to be aware of this condition. Further management depends on the cause, frequency of attacks, severity of symptoms and the duration of the illness

DESIGN OF A PWM BASED BUCK BOOST DC/DC CONVERTER WITH PARASITIC RESISTANCE SUITABLE FOR LED BASED UNDERGROUND COALMINES LIGHTING SYSTEM IJEET © I A E M E

Abstract This paper develops a light emitting diode (LED) driver circuit based on buckboost converter including parasitic resistance. The efficiency and ripple calculation of the buck boost converter and whole system has been obtained by considering parasitic resistance of the component because the resistance of an LED varies with temperature, making the circuit unstable. The forward bias of the LED used was 3.0V~4.5V, and the forward current was 0.6A. An array of five and eight white-light LEDs were driven as per the proposed circuit. In an LED only 15% to 25% of electrical energy is converted into light; the rest is converted into heat, which increases its temperature. In some typical application like designing of lighting system for underground coalmines this change in resistance can cause hazardous effect. Hence, LED must be operated at constant current for constant illumination for at least 10-12 hours without failure. Therefore, a closed-loop control system has been designed in this paper to increase output voltage stability. It has been observed that at 600mA and at 12V LEDs are operated efficiently. The driver circuit is operated in continuous buck-boost mode and the results are then simulated using PSIM software

All-Solid-State UV Transmitter Development for Ozone Sensing Applications

In this paper, recent progress made in the development of an all-solid-state UV transmitter suitable for ozone sensing applications from space based platforms is discussed. A nonlinear optics based UV setup based on Rotated Image Singly Resonant Twisted Rectangle (RISTRA) optical parametric oscillator (OPO) module was effectively coupled to a diode pumped, single longitudinal mode, conductively cooled, short-pulsed, high-energy Nd:YAG laser operating at 1064 nm with 50 Hz PRF. An estimated 10 mJ/pulse with ~10% conversion efficiency at 320 nm has been demonstrated limited only by the pump pulse spatial profile. The current arrangement has the potential for obtaining greater than 200 mJ/pulse. Previously, using a flash-lamp pumped Nd:YAG laser with round, top-hat profile, up to 24% IR-UV conversion efficiency was achieved with the same UV module. Efforts are underway to increase the IR-UV conversion efficiency of the all solid-state setup by modifying the pump laser spatial profile along with incorporating improved OPO crystals

Recent Progress Made in the Development of High-Energy UV Transmitter

In this paper, the status of an all-solid-state UV converter development for ozone sensing applications is discussed. A high energy Nd:YAG laser for pumping the UV converter arrangement was recently reported. The pump is an all-solid-state, single longitudinal mode, and conductively cooled Nd:YAG laser operating at 1064 nm wavelength. Currently, this pump laser provides an output pulse energy of greater than 1J/pulse at 50 Hz PRF and a pulsewidth of 22 ns with an electrical-to-optical system efficiency of greater than 7% and a M(sup 2) value of approx. 2. The spatial profile of the output beam is a rectangular super Gaussian. This Nd:YAG pump laser has been developed to pump the nonlinear optics based UV converter arrangement to generate 320 nm and 308 nm wavelengths by means of 532 nm wavelength. Previously, this UV converter arrangement has demonstrated IR-to-UV conversion efficiency of 24% using a flash lamp pumped laser providing a round, flat top spatial profile. Recently, the UV converter was assembled and tested at NASA LaRC for pumping with the diode pumped Nd:YAG laser. With current spatial profile, the UV converter was made operational. Current efforts to maximize the nonlinear conversion efficiency by refining its spatial profile to match RISTRA OPO requirements are progressing

Single-mode, All-Solid-State Nd:YAG Laser Pumped UV Converter

In this paper, the status of a high-energy, all solid-state Nd:YAG laser pumped nonlinear optics based UV converter development is discussed. The high-energy UV transmitter technology is being developed for ozone sensing applications from space based platforms using differential lidar technique. The goal is to generate greater than 200 mJ/pulse with 10-50 Hz PRF at wavelengths of 308 nm and 320 nm. A diode-pumped, all-solid-state and single longitudinal mode Nd:YAG laser designed to provide conductively cooled operation at 1064 nm has been built and tested. Currently, this pump laser provides an output pulse energy of >1 J/pulse at 50 Hz PRF and a pulsewidth of 22 ns with an electrical-to-optical system efficiency of greater than 7% and a M(sup 2) value of <2. The single frequency UV converter arrangement basically consists of an IR Optical Parametric Oscillator (OPO) and a Sum Frequency Generator (SFG) setups that are pumped by 532 nm wavelength obtained via Second Harmonic Generation (SHG). In this paper, the operation of an inter cavity SFG with CW laser seeding scheme generating 320 nm wavelength is presented. Efforts are underway to improve conversion efficiency of this mJ class UV converter by modifying the spatial beam profile of the pump laser

High Energy, Single-Mode, All-Solid-State and Tunable UV Laser Transmitter

A high energy, single mode, all solid-state Nd:YAG laser primarily for pumping an UV converter is developed. Greater than 1 J/pulse at 50 HZ PRF and pulse widths around 22 ns have been demonstrated. Higher energy, greater efficiency may be possible. Refinements are known and practical to implement. Technology Demonstration of a highly efficient, high-pulse-energy, single mode UV wavelength generation using flash lamp pumped laser has been achieved. Greater than 90% pump depletion is observed. 190 mJ extra-cavity SFG; IR to UV efficiency > 21% (> 27% for 1 mJ seed). 160 mJ intra-cavity SFG; IR to UV efficiency up to 24% Fluence < 1 J/sq cm for most beams. The pump beam quality of the Nd:YAG pump laser is being refined to match or exceed the above UV converter results. Currently the Nd:YAG pump laser development is a technology demonstration. System can be engineered for compact packaging