225 research outputs found

    Anisotropic Compact Star Model on Finch-Skea Spacetime

    Full text link
    In this study, we demonstrate a new anisotropic solution to the Einstein field equations in Finch-Skea spacetime. The physical features of stellar configuration are studied in previous investigations. We create a model that meets all physical plausibility conditions for a variety of stars and plot graphs for \textbf{4U 1820-30}.Comment: 9 figures, 1 table and 7 page

    Superconductivity with high upper critical field in Ta-Hf Alloys

    Full text link
    High upper-critical field superconducting alloys are required for superconducting device applications. In this study, we extensively characterized the structure and superconducting properties of alloys Tax_{x} Hf1x_{1-x} (x = 0.2, 0.4, 0.5, 0.6 and 0.8). The substitution of Hf (TC_{C} = 0.12 K, type-I superconductor) with Ta (TC_{C} = 4.4 K, type-I superconductor) shows an anomalous enhancement of TC_{C} with variation of composition. Interestingly, all compositions exhibited strongly coupled bulk type-II superconductivity with a high upper critical field. In particular, for compositions x = 0.2, and 0.4, the upper critical field (HC2_{C2}) approached the Pauli limiting field.Comment: 8 pages, 6 figure

    Study of various reasons for interruption of anti-tubercular treatment in patients of tuberculosis reporting to tertiary care center of west Rajasthan

    Get PDF
    Background: Tuberculosis is a major cause of death in India. Premature cessation of treatment in tuberculosis patient is a leading cause for developing MDR (multidrug resistant tuberculosis) as well as a major threat to control programs. Despite the easy approach and free of cost, availability to antitubercular medicines the interruptions of the treatment are still on a high. So, we analyzed  such various reasons  leading to interrupt the antitubercular treatment.Methods: Total 150 patients who interrupted the antitubercular treatment, were interviewed with a predesigned questionnaire and the result was analyzed.Results: Out of total 150 patients 115 (76.7%)  male and 35 (23.3%)  female were interviewed, who were  having  history of antitubercular treatment interruption. Out of 150 patients, 79 (52.7%) patients stopped their treatment because of improvement. Total 25 (16.7%) patients had stopped their treatment because of high cost, 16 (10.7%) due to personal/family reason, 17 (11.4%) patients had stopped their treatment due to nausea/vomiting/anorexia, 5 (3.3%) due to alcoholism/drug or other addiction, 2 (1.3%) patients  had stopped their treatment because they were advised to stop it  by health personnel and long distance travelled to take drugs.Conclusions: Improvement of symptoms was  the most common reason  in patients who received DOTS treatment and high cost of treatment in patients who received non DOTS treatment. Poor education and socioeconomic status of society are the other reasons for possible treatment interruptions because as soon as the patient improves, they move out to earn their wages to run the family with the unavoidable default from the treatment

    Emulating Thin Clients and Voice-over-IP with Wane

    Full text link
    Volume 2 Issue 8 (August 2014

    Circular Patch Antenna with Defected Ground for UWB Communication with WLAN Band Rejection

    Get PDF
    The design and performance of coplanar waveguide fed modified circular patch antenna for possible application in ultra wideband communication systems with band rejection for upper wireless local area network band (5.15 GHz - 5.85 GHz) is reported. This antenna is designed on glass epoxy FR4 substrate having size 30 mm × 20 mm × 1.59 mm. The coplanar waveguide fed circular patch antenna is modified by introducing L shaped slits in ground plane and U shaped slot in patch and performance analysis of antenna is simulated by applying CST microwave studio simulation software. Different designed antennas were tested with available experimental facilities. The developed end product shows a nice matching with feed network at frequencies 2.62 GHz, 3.94 GHz and 8.50 GHz and provides 10.38 GHz (3.33 GHz - 13.71 GHz) impedance bandwidth with wireless local area network 5.5 GHz (4.74 GHz - 6.15 GHz) band rejection. The co and cross polar patterns in elevation and azimuth planes at two frequencies namely 2.62 GHz and 3.94 GHz are obtained which dictate that co-polar patterns are significantly better than cross polar patterns. The simulated peak gain of antenna is close to 3.86 dBi and gain variation with frequency shows a sharp gain decrease in the frequency range 4.74 GHz to 6.15 GHz.

    Uncertainties in dynamic response of buildings with non-linear base-isolators

    Get PDF
    Dynamic response of base-isolated buildings under uni-directional sinusoidal base excitation is numerically investigated considering uncertainties in the isolation and excitation parameters. The buildings are idealized as single degree of freedom (SDOF) system and multi-degrees of freedom (MDOF) system with one lateral degree of freedom at each floor level. The isolation system is modeled using two different mathematical models such as: (i) code-recommended equivalent linear elastic-viscous damping model and (ii) bi-linear hysteretic model. The uncertain parameters of the isolator considered are time period, damping ratio, and yield displacement. Moreover, the amplitude and frequency of the sinusoidal base excitation function are considered uncertain. The uncertainty propagation is investigated using generalized polynomial chaos (gPC) expansion technique. The unknown gPC expansion coefficients are obtained by non-intrusive sparse grid collocation scheme. Efficiency of the technique is compared with the sampling method of Monte Carlo (MC) simulation. The stochastic response quantities of interest considered are bearing displacement and top floor acceleration of the building. Effects of individual uncertain parameters on the building response are quantified using sensitivity analyses. Effect of various uncertainty levels of the input parameters on the dynamic response of the building is also investigated. The peak bearing displacement and top floor acceleration are more influenced by the amplitude and frequency of the sinusoidal base excitation function. The effective time period of the isolation system also produces a considerable influence. However, in the presence of similar uncertainty level in the time period, amplitude and frequency of the sinusoidal forcing function, the effect of uncertainties in the other parameters of the isolator (e.g., damping ratio and yield displacement) is comparatively less. Interestingly, the mean values of the response quantities are found to be higher than the deterministic values in several instances, indicating the need of conducting stochastic analysis. The gPC expansion technique presented here is found to be a computationally efficient yet accurate alternative to the MC simulation for numerically modeling the uncertainty propagation in the dynamic response analyses of the base-isolated buildings

    Identification and authentication of Agnimantha plant species used in Ayurveda on the basis of anatomical and molecular phylogenetic analysis

    Get PDF
    Agnimantha plant species have been used in the Ayurvedic system of medicine for many years and is widely used as an ingredient in many ayurvedic formulations. However, the source for Agnimantha remained controversial as it is difficult to authenticate from various reports. Hence, the present study aims to identify and authenticate its original and substitute sources. As per the literature sources Clerodendrum phlomidis L.f., C. inerme (L.) Gaertn. and Premna serratifolia L. are considered Agnimantha species. The anatomy of the above mentioned species confirmed the presence of patches of up to 20 cells in the sclerenchyma of the root cortex, while in the absence of sclerenchyma of the stem cortex, abundant chambered crystals were also present in the bark of the stem and root in C. phlomidis as compared to C. inerme and P. serratifolia. Phylogenetic analysis using chloroplast (matK, trnH-psbA) and nuclear markers (ITS, rbcl) also indicates the close relation between C. inerme and P. serratifolia and hence places them both in the same clade, though C. phlomidis is closely related to the other species but placed in the adjacent clade. Hence, the study concludes that anatomical as well as molecular phylogenetic analysis reflect close relation between C. inerme and P. serratifolia. while a distant relation with C. phlomidis

    RF Controlled Robotic Vehicle with Metal Detection Project

    Full text link
    The project is intended to cultivate a robotic vehicle that can sense metals ahead of it on its path similar to detecting land mines. The robot is controlled by a remote using RF technology. It consists of a metal detector circuit interfaced to the control unit that alarms the user behind it about a doubted land mine ahead. An 8051 series of microcontroller is used for the preferred operation. For controlling the movement of robot either to forward, backward & right or left commands are sent to the receiver by using push buttons of the transmitter. At the receiving end two motors are interfaced to the microcontroller where they are used for the movement of the vehicle. The RF transmitter acts as a RF remote control that has the advantage of sufficient range (up to 200 meters) with proper antenna, while the receiver decodes before serving it to another microcontroller to drive DC motors via motor driver IC for necessary work. A metal detector circuit is attached on the robot body and its operation is carried out automatically on sensing any metal underneath. The instant the robot senses this metal it produces an alarm sound through buzzer. This is to aware the operator of a probable metal (eg: land mine) ahead on its path. Further the project can be enhanced by mounting a wireless camera on the robot so that the operator can govern the movement of the robot remotely by observing it on a screen

    Ring Slotted Circularly Polarized U-Shaped Printed Monopole Antenna for Various Wireless Applications

    Get PDF
    In this communication, the design and performance of strip line feed U-shaped printed monopole antenna for Bluetooth/WI-Max/WLAN communications systems is reported. Proposed monopole antenna has an eight shaped slot on the patch and an eight shaped ring structure in the ground plane with metallic reflector just beneath the radiating element. The CST Microwave Studio 2014 is used for the simulation analysis of antennas while measurements are performed by applying Vector Network Analyzer. This radiating structure provides triple broad impedance bandwidths i.e. 265MHz (in 2.280 GHz to 2.545 GHz frequency range), 116 MHz (in 2.660 GHz to 2.776 GHz frequency range) and 2.12 GHz (in 3.83 GHz to 5.956 GHz frequency range), wider 3dB axial ratio bandwidth 1.33 GHz (in 4.69GHz to 6.02GHz range), flat gain (with maximum gain close to 5.56 (dBi) and good radiation patterns in the desired frequency range. This antenna may be a useful structure for 2.45GHz Bluetooth communication band as well as in WLAN and Wi-Max communications bands
    corecore