RESUMO
A modular electromagnetic railgun accelerator facility named "RAFTAR" (i.e., Railgun Accelerator Facility for Technology and Research) has been commissioned and its performance has been characterized for high velocity impact testing on materials in a single-shot mode. In the first tests, RAFTAR demonstrated an acceleration of more than 1000 m/s for an 8 g solid aluminum-7075 armature projectile. The current fed was 220 kA, having a muzzle time of about 1.75 ms. It is a single pulse breech-fed rectangular bore (14 × 13 mm2) railgun, and its 1.15 m long barrel assembly consists of two parallel copper bars with an inter-gap of 13 mm that are encased within 50 mm thick high strength reinforced fiberglass sheets (Garolite G10-FR4) and bolted from both the sides. RAFTAR is powered by two capacitor bank modules that have a maximum stored energy of 160 kJ each (containing eight 178 µF/15 kV capacitors), two high power ignitron switches, and a pulse shaping inductor. To obtain consistent acceleration of the armature inside the barrel, reversal of driving current is prevented, and its pulse duration is stretched by tactical integration of the crowbar switch and bitter coil inductor in the circuit. Armature projectile velocity measurement in-bore and outside in free space was performed by the time-of-flight technique using indigenously made miniature B-dot sensors and a novel shorting-foil arrangement, respectively. The time resolved measurement of the in-bore armature evidenced a velocity-skin-effect in the high acceleration phase. There is good agreement between the experimentally measured and theoretically predicted efficiency, confirming the optimal choice of operating parameters. The conclusion summarizes important experimental findings and analyzes the underlying causes that limit the performance of railguns.
RESUMO
This work was designed to assess the efficacy of Nasya in reducing the signs and symptoms of cervical spondylosis. The patients attending the O. P. D of Department of Kaya Chikitsa and Panchakarma, Government Ayurveda College Hospital, Thiruvananthapuram were enrolled and subjected to the treatment schedule. Total duration of treatment was 21days. The schedule for the first 14 days was similar in both the groups. It included Rooksha Sveda for 7days followed by Patra Pottali Sveda for 7days. During this period, 90 ml Gandharvahastadi Kashaya twice and Guggulu Tiktaka Kashaya once were given internally. After this, in the Nasya group Nasya was done for 7days with Dhanwantaram Tailam (21times Aavartita), MriduPaka in Madhyama Matra (8Bindu). Along with this Guggulu Tiktaka Kashaya was given thrice. In the control group, Guggulu Tiktaka kashaya alone was given thrice daily. Assessments were done with regard to pain, tenderness, radiation of pain, numbness, range of movements and hand grip strength. These were done before treatment, before nasya, after treatment and after 1month follow-up. The statistical hypothesis was tested using paired 't' test and 'Z' test for proportion. The trial proved that conventional management along with Nasya was more efficacious than conventional management alone in reducing the signs and symptoms of cervical spondylosis.
RESUMO
CONTEXT: Nephrotoxicity induced by several synthetic drugs is a major problem of modern age. Medicinal plants and phytomedicine are the prime choice of research as they possess better activity and lesser side effects. OBJECTIVE: To investigate the protective effect of Cardiospermum halicacabum Linn. (Sapindaceae), methanol and petroleum ether extracts against acetaminophen-induced nephrotoxicity in rats. MATERIALS AND METHODS: Nephrotoxicity was induced by the administration of acetaminophen suspension (750 mg/kg, p.o.) after the pretreatment with methanol extract (MECF) and petroleum ether extract (PEECF) of Cardiospermum halicacabum for 7 days. Forty-eight h after the acetaminophen administration estimations of serum alkaline phosphate, creatinine, blood urea nitrogen, uric acid, total proteins, cholesterol, albumin level and histological analysis of kidney injuries were determined. RESULTS: In nephrotoxic animals, a significant (P < 0.01) elevation of serum alkaline phosphate, creatinine, blood urea nitrogen, uric acid, cholesterol and depletion of total proteins and albumin were observed. Pretreatment with MECF and PEECF (400 mg/kg) significantly (P < 0.01, P < 0.05) decreased serum alkaline phosphate, creatinine, blood urea nitrogen, uric acid, cholesterol level and causes elevation of total protein and albumin level, though MECF produces better effect than PEECF in rats. Histopathological studies also confirm the protective effect of extracts. The protective effect of Cardiospermum halicacabum was associated with restoration of serum alkaline phosphate, creatinine, blood urea nitrogen, uric acid, cholesterol, total protein and albumin level. DISCUSSION AND CONCLUSIONS: Methanol and petroleum ether extracts of Cardiospermum halicacabum had a significant nephroprotective activity against acetaminophen-induced nephrotoxicity in rats.
