82 research outputs found

    Energy optimization of 6T SRAM cell using low-voltage and high-performance inverter structures

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    The performance of the cell deteriorates, when static random access memory (SRAM) cell is operated below 1V supply voltage with continuous scale down of the complementary metal oxide semiconductor (CMOS) technology. The conventional 6T, 8T-SRAM cells suffer writeability and read static noise margins (SNM) at low-voltages leads to degradation of cell stability. To improve the cell stability and reduce the dynamic power dissipation at low- voltages of the SRAM cell, we proposed four SRAM cells based on inverter structures with less energy consumption using voltage divider bias current sink/source inverter and NOR/NAND gate using a pseudo-nMOS inverter. The design and implementation of SRAM cell using proposed inverter structures are compared with standard 6T, 8T and ST-11T SRAM cells for different supply voltages at 22-nm CMOS technology exhibit better performance of the cell. The read/write static noise margin of the cell significantly increases due to voltage divider bias network built with larger cell-ratio during read path. The load capacitance of the cell is reduced with minimized switching transitions of the devices during high-to-low and low- to-high of the pull-up and pull-down networks from VDD to ground leads to on an average 54% of dynamic power consumption. When compared with the existing ones, the read/write power of the proposed cells is reduced to 30%. The static power gets reduced by 24% due to stacking of transistors takes place in the proposed SRAM cells as compare to existing ones. The layout of the proposed cells is drawn at a 45-nm technology, and occupies an area of 1.5 times greater and 1.8 times greater as compared with 6T-SRAM cell

    Coculture fermentation of banana agro-waste to ethanol by cellulolytic thermophilic Clostridium thermocellum CT2

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    Banana is a major cash crop of many regions generating good amount of waste after harvest. This agro waste which is left for natural degradation is used as substrate for single step ethanol fermentation by thermophilic, cellulolytic, ethanologenic Clostridium thermocellum CT2, a new culture isolated from elephant droppings. Scanning electron microscopic pictures clearly indicate cellulolysis and close interaction of selected isolate CT2 with cellulose. The optimum conditions for cellulose fermentation were 60°C, pH 7.5, inoculums size 5% and incubation time 5 days. Ethanol produced and reducing sugars were estimated by gas chromatography. Clostridium thermosaccharolyticum HG8 and Thermoanaerobacter ethanolicus ATCC 31937 were used in coculture fermentation with CT2. Coculture fermentation of CT2 with HG8 was more efficient in terms of ethanol production, cellulose degradation and reducing sugars utilization. A maximum ethanol yield of 0.41g/g substrate used was obtained oncoculturing CT2 with HG8 on alkali treated banana waste. Coculture was active even at substrate concentrations up to 100 g/l, a maximum ethanol of 22 g/l was obtained at 100 g/l substrate concentration on coculturing CT2 with HG8. This is the first report on anaerobic single step conversionof banana waste to ethanol by C. thermocellum

    Characterization and bioactivity of oosporein produced by endophytic fungus Cochliobolus kusanoi isolated from Nerium oleander L

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    Bioactive compds. comprising secondary metabolites produced by endophytic fungi have wide applications in pharmacol. and agriculture. Isolation, characterization and evaluation of biol. activities of secondary metabolites were carried out from Cochliobolus kusanoi, an endophytic fungus of Nerium oleander L. The fungus was identified based on 18S rDNA sequence anal. There are no reports available on the compds. of C. kusanoi; hence, antimicrobial metabolites produced by this fungus were extd. and purified by fractionation using hexane, di-​Et ether, dichloromethane, Et acetate and methanol. Out of all the solvent fractions, the methanol fraction exhibited better antimicrobial activity which was further purified and characterized as oosporein. Oosporein from C. kusanoi exhibited broad spectrum in vitro antimicrobial, antioxidant and cytotoxic activities

    A Novel Single-Reference Six-Pulse-Modulation (SRSPM) Technique-Based Interleaved High-Frequency Three-Phase Inverter for Fuel Cell Vehicles

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    Abstract: This paper presents a hybrid modulation technique consisting of singe-reference six-pulse-modulation (SRSPM) for front-end dc/dc converter and 33% modulation for three-phase inverter. Employing proposed novel SRSPM to control front-end dc/dc converter, high frequency (HF) pulsating dc voltage waveform is produced, which is equivalent to six-pulse output at 6× line frequency (rectified 6-pulse output of balanced three-phase ac waveforms) once averaged. It reduces the control complexity owing to single-reference three-phase modulation as compared to conventional three-reference three-phase SPWM. In addition, it relives the need of dclink capacitor reducing the cost and volume. Eliminating dc link capacitor helps in retaining the modulated information at the input of the three-phase inverter. It needs only 33% (one third) modulation of the inverter devices to generate balanced three-phase voltage waveforms resulting in significant saving in (at least 66%) switching losses of inverter semiconductor devices. At any instant of line cycle, only two switches are required to switch at HF and remaining switches retain their unique state of either ON or OFF. Besides, inverter devices are not commutated when the current through them is at its peak value. Drop in switching loss accounts to be around 86.6% in comparison with a standard voltage source inverter (VSI) employing standard three-phase sine pulse width modulation. This paper explains operation and analysis of the HF two-stage inverter modulated by the proposed novel modulation scheme. Analysis has been verified by simulation results using PSIM9.0.4. Experimental results demonstrate effectiveness of the proposed modulation

    Family-led rehabilitation after stroke in India (ATTEND): a randomised controlled trial

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    Background Most people with stroke in India have no access to organised rehabilitation services. The effectiveness of training family members to provide stroke rehabilitation is uncertain. Our primary objective was to determine whether family-led stroke rehabilitation, initiated in hospital and continued at home, would be superior to usual care in a low-resource setting. Methods The Family-led Rehabilitation after Stroke in India (ATTEND) trial was a prospectively randomised open trial with blinded endpoint done across 14 hospitals in India. Patients aged 18 years or older who had had a stroke within the past month, had residual disability and reasonable expectation of survival, and who had an informal family-nominated caregiver were randomly assigned to intervention or usual care by site coordinators using a secure web-based system with minimisation by site and stroke severity. The family members of participants in the intervention group received additional structured rehabilitation training—including information provision, joint goal setting, carer training, and task-specific training—that was started in hospital and continued at home for up to 2 months. The primary outcome was death or dependency at 6 months, defined by scores 3–6 on the modified Rankin scale (range, 0 [no symptoms] to 6 [death]) as assessed by masked observers. Analyses were by intention to treat. This trial is registered with Clinical Trials Registry-India (CTRI/2013/04/003557), Australian New Zealand Clinical Trials Registry (ACTRN12613000078752), and Universal Trial Number (U1111-1138-6707). Findings Between Jan 13, 2014, and Feb 12, 2016, 1250 patients were randomly assigned to intervention (n=623) or control (n=627) groups. 33 patients were lost to follow-up (14 intervention, 19 control) and five patients withdrew (two intervention, three control). At 6 months, 285 (47%) of 607 patients in the intervention group and 287 (47%) of 605 controls were dead or dependent (odds ratio 0·98, 95% CI 0·78–1·23, p=0·87). 72 (12%) patients in the intervention group and 86 (14%) in the control group died (p=0·27), and we observed no difference in rehospitalisation (89 [14%]patients in the intervention group vs 82 [13%] in the control group; p=0·56). We also found no difference in total non-fatal events (112 events in 82 [13%] intervention patients vs 110 events in 79 [13%] control patients; p=0·80). Interpretation Although task shifting is an attractive solution for health-care sustainability, our results do not support investment in new stroke rehabilitation services that shift tasks to family caregivers, unless new evidence emerges. A future avenue of research should be to investigate the effects of task shifting to health-care assistants or team-based community care

    Distributed deadlock detection in computer networks

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    Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to [email protected], referencing the URI of the item.Includes bibliographical references.Not availabl
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