http://nopr.niscpr.res.in/handle/123456789/19297 2026-10-09T07:06:16Z http://nopr.niscpr.res.in/handle/123456789/25682 Title: Theoretical modeling of a dielectric-loaded box-horn applicator for hyperthermia treatment of tumors in thorax region Authors: Gupta, Ramesh Chandra; Singh, S P Abstract: This paper presents theoretical analysis of the specific absorption rate (SAR) distribution in three-layered tissue (fat, muscle and lung layers as in thorax region) in direct contact with a box-horn applicator for hyperthermia treatment of cancerous tumor. The box-horn is assumed to be filled with dielectric (ceramic NPOT-96) to provide a better impedance match to bio-media. The present analysis is based on plane wave spectral technique. The spatial distribution of SAR in fat, muscle and lung layers are computed and reported at 433 and 2450 MHz. Wider SAR-distribution in each of the bio-layers in cross-sectional area and higher penetration depth in lung are observed at 433 MHz in comparison to those at 2450 MHz for dielectric-loaded box-horn. The normalized SAR distributions are also reported for various tissues (fat/muscle/lung layers) at the same depth in order to make a comparative study in these tissues. A modified box-horn, in which the horn is flared in both E- and H-planes is also considered. The effect of substituting pyramidal horn in place of H-plane sectoral horn in the design of box-horn on the SAR distribution is also examined. The results have been validated against available published results in the literature. Page(s): 438-445 2005-12-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/25681 Title: Influence of nationwide truck strike on black carbon aerosols over urban environment of Hyderabad, India Authors: Latha, K Madhavi; Badarinath, K V S Abstract: Black carbon (BC) aerosols have a major impact on human health besides global and regional climate. Measurements on spatial distribution of BC remains poor and severely hampers attempts to assess its radiative effects and the situation can be improved by more measurements of BC aerosols across the globe. A study has been carried out in the urban area, Hyderabad to assess the impact of nation-wide truck strike in August 2004 on ambient BC concentrations. The results indicate significant reduction in the BC loading associated with the withdrawal of the trucks. The decrease in BC concentrations has been observed to be gradual while the recovery was almost immediate after the strike was called off. The study provides information on influence of anthropogenic activities such as absence of diesel trucks on BC aerosols in urban areas. Page(s): 435-437 2005-12-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/25680 Title: Effect of environmental changes on the performance of ILS located at Hyderabad airport Authors: Ramalingam, K; Rao, G Sasibhushana; Ramakrishna, K; Sarma, A D Abstract: In civil aviation, the existing precision approach (PA) landing system equipment has certain limitations due to ground environment, which affects the performance of the equipment. The effect of changes in the environment conditions surrounding the airport on Instrumental Landing System (ILS) course structure has been presented by comparing the calibrated and measured data at Hyderabad airport (India). The field strength data are acquired using the NORMAC ILS signal field test receiver and compared with the calibration aircraft (AVRO HS-748) data. Performance of the existing ILS is analyzed and the results confirm the effect of environmental changes on the ILS course structure. Page(s): 431-434 2005-12-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/25679 Title: Analysis of slot-loaded rectangular microstrip patch antenna Authors: Shivnarayan; Sharma, Shashank; Vishvakarma, Babau R Abstract: In the present paper, the analysis of a slot-loaded rectangular microstrip patch antenna using equivalent circuit concept is presented. The slot is taken as a capacitive reactance on the patch. It is found that the resonance frequency decreases with increasing slot width for a given slot length. The decrease in the resonance frequency is in the higher side for longer slot length, whereas it is on the minimum side for the lower slot length. It is found that VSWR remains almost invariant with slot width and slot length. The impedance increases almost linearly with the slot width, but inversely with the slot length. Page(s): 424-430 2005-12-01T00:00:00Z