Analytical approximation of a distorted reflector surface defined by a discrete set of points

Reflector antennas on Earth orbiting spacecrafts generally cannot be described analytically. The reflector surface is subjected to a large temperature fluctuation and gradients, and is thus warped from its true geometrical shape. Aside from distortion by thermal stresses, reflector surfaces are often purposely shaped to minimize phase aberrations and scanning losses. To analyze distorted reflector antennas defined by discrete surface points, a numerical technique must be applied to compute an interpolatory surface passing through a grid of discrete points. In this paper, the distorted reflector surface points are approximated by two analytical components: an undistorted surface component and a surface error component. The undistorted surface component is a best fit paraboloid polynomial for the given set of points and the surface error component is a Fourier series expansion of the deviation of the actual surface points, from the best fit paraboloid. By applying the numerical technique to approximate the surface normals of the distorted reflector surface, the induced surface current can be obtained using physical optics technique. These surface currents are integrated to find the far field radiation pattern

Adverse effects of anti-epileptic, anti-hypertensive, anti-diabetic and anti-arrhythmic drugs on hematological and hepatic parameters

Multiple drug administration increases chances of drug interaction, altering the responses of drugs either increasing or decreasing pharmacological effects, or generating a new pharmacological response. Generally drug interactions should be avoided, due to the possibility of poor or unexpected outcomes. The present study was designed to explore relatively safe combination that can be used in individuals with multiple disorders such as epilepsy, hypertension, arrhythmia and diabetes. The study was conducted in normal rabbits of either sex following administration of drugs for a period of 60 days; various biochemical tests were performed to assess their hepatic and hematological profile. Results of this study suggest that animals of group receiving amiodarone-glibenclamide-captopril-oxcarbazepine combination revealed comparatively more toxic effects than two other combinations.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Hilbert-Curve Fractal Antenna With Radiation- Pattern Diversity

A printed, folded, Hilbert-curve fractal microwave antenna has been designed and built to offer advantages of compactness and low mass, relative to other antennas designed for the same operating frequencies. The primary feature of the antenna is that it offers the advantage of radiation-pattern diversity without need for electrical or mechanical switching: it can radiate simultaneously in an end-fire pattern at a frequency of 2.3 GHz (which is in the S-band) and in a broadside pattern at a frequency of 16.8 GHz (which is in the Ku-band). This radiation-pattern diversity could be utilized, for example, in applications in which there were requirements for both S-band ground-to-ground communications and Ku-band ground-to-aircraft or ground-to-spacecraft communications. The lack of switching mechanisms or circuitry makes this antenna more reliable, easier, and less expensive to fabricate than it otherwise would be

“PREVALENCE OF SHOULDER PAIN IN PETROL PUMP WORKERS”

Shoulder pain (SP) is the most common problem in workers exposed to repetitive shoulder activity in their occupation. The petrol pump workers, who have repetitive activities of shoulder joint by picking and keeping the nozzle at petrol pump station.  This repetitive activity increases the demand on the muscles, ligaments, soft tissues of musculoskeletal system. This activity is carried out in standing posture. So the purpose of the present study is to know the prevalence of shoulder pain in petrol pump workers. So, the aim of the present study the prevalence of shoulder pain in petrol pump workers. A Observational –Cross sectional study done on 100 Petrol Pump Workers selected randomly with the job profile of filling the fuel with nozzle in vehicles 20 – 40 years of age  working since > 6months, without any shoulder injury, trauma and  neurological musculoskeletal problem. Questionnaire was prepared and validated. Non Parametric Test Were Applied. In this study only 49% Petrol Pump Workers people had shoulder pain where as 51% did not shoulder pain had. The study shows that Petrol Pump workers ageing from 31 – 40 years who have experience of profession more than 5 years often suffer from shoulder pain which may be associated with repetitive activity of shoulder and faulty posture while working

Pharmacological investigation of selected medicinal plants of Bangladesh

Purpose: To pharmacologically investigate the methanol and petroleum ether extracts of the plant leaves of Manilkara zapota (MZME and MZPE, respectively), Abroma augusta (AAME and AAPE, respectively) and Vitex negundo (VNME and VNPE, respectively).Methods: Analgesic and anti-diarrheal activities were assessed by acetic acid-induced writhing and castor oil-induced diarrhea in mice, respectively, while CNS depressant activity was evaluated using hole-cross and open-field method by observing the decrease in exploratory behavior and spontaneous motor activity in mice, respectively.Results: All the extracts exhibited good analgesic activity at a dose of 200 mg/kg with the following rank order of activity: MZME > MZPE > VNME > VNPE > AAME > AAPE. Analgesic activity was insignificant at 100 mg/kg dose except for VNPE (67.81 % inhibition). The extracts produced significant reduction in diarrheal episodes in mice at a dose of 400 mg/kg MZPE (highest protection: 80.3 %, p < 0.05) and VNME (lowest protection: 38.6 %, p < 0.001). The extracts demonstrated CNS depressant activity in a dose-dependent manner (p < 0.05 compared to the standard except for AAME and AAPE which showed insignificant activity).Conclusion: The results indicate that the traditional use of the investigated plants appears to be justified; however, further studies are required to unravel the underlying mechanisms of action.Keywords: Manilkara zapota, Abroma augusta, Vitex negundo, Analgesic, Central nervous system depressant, Anti-diarrhoea

Determinants of male participation in reproductive healthcare services: a cross-sectional study

Background The role of male’s participation in reproductive healthcare is now well-recognized. The present study investigated the role of men in some selected reproductive health issues, characterizing their involvement, including factors influencing their participation in reproductive healthcare services. Methods This study was conducted in the working areas of urban and rural implemented by NGOs. The sample-size was determined scientifically. The systematic sampling procedure was used for selecting the sample. The study included 615 men aged 25-45 years. Bivariate analysis was performed between male’s involvement as the dependent variable with several independent variables. Logistic regression analysis was applied to assess the effects of risk factors on the participation of men in reproductive health care services. Results The mean age of the respondents was little over 34 years while their mean years of schooling was 3.7, and their mean monthly income was about Tk 3,400 (US$ 1 = Tk 70) at the time of the study. Rickshaw-pulling and driving was the main occupation of the respondents from the urban while farming were main occupation in the rural area respectively. About two-thirds of the respondents discussed reproductive health issues with their wives and accompanied them to healthcare facilities. The current contraceptive-use rate was 63% among the men who attended the evening clinics. Results of bivariate analysis showed a significant association with education, occupation, income, access to media, and number of living children. Results of logistic regression analysis showed that secondary to higher education level, number of living children, paid employment status, long marital duration, and access to media were important correlates of males’ involvement in reproductive healthcare services. Conclusions The results imply that a greater integration of reproductive healthcare matters with the Millennium Development Goals and increasing perception of men through enrollment in various components of reproductive activities will produce synergistic effects

Enhanced regeneration in explants of tomato (Lycopersicon esculentum L.) with the treatment of coconut water

A standardized protocol was developed to enhance the in vitro regeneration efficiency of five varieties of tomato from hypocotyls and leaf disc with the involvement of coconut water. Different concentrations of IAA and kinetin were used alone and in combination with 12% of coconut water.Significant differences for regeneration, time taken to regenerate and number of leaf primordial were observed for different treatments, type of explant, use of coconut water and also among varieties. Higher regeneration was obtained in Avinash followed by Roma and Rio Grande. Maximum regeneration 95.75% was obtained with 0.5 mgL-1 of IAA, 1.5 mgL-1 Kinetin along with 12% coconut water in Avinash and hypocotyl was proved to be better for regeneration than leaf discs. The inclusionof coconut water in the media significantly reduced the number of days taken for callus induction leading to regeneration, as compared to media without coconut water. Significant increase in number of shoot primordial was observed in hypocotyls as well as in leaf disc derived calli with the addition of coconut water. Plants obtained were transferred to the glass house in small pots of compost and higher frequency of survival was observed from plantlets obtained with the addition of coconut water

Baseline antenna design for space exploration initiative

A key element of the future NASA Space Exploration Initiative (SEI) mission is the lunar and Mars telecommunication system. This system will provide voice, image, and data transmission to monitor unmanned missions to conduct experiments, and to provide radiometric data for navigation. In the later half of 1991, a study was conducted on antennas for the Mars Exploration Communication. Six antenna configurations were examined: three reflector and three phased array. The conclusion was that due to wide-angle scan requirement, and multiple simultaneous tracking beams, phased arrays are more suitable. For most part, this report studies phased array antenna designs for two different applications for Space Exploration Initiative. It also studies one design for a tri-reflector type antenna. These antennas will be based on a Mars orbiting satellite