Assessing solar energy potential using diurnal remote-sensing observations from Kalpana-1 VHRR and validation over the Indian landmass

A spectrally integrated clear-sky and three-layer cloudy-sky models were developed to determine atmospheric transmittances and instantaneous surface insolation. Half-hourly observations at 8 km spatial resolution in optical and thermal infrared bands from an Indian geostationary satellite (Kalpana-1) Very High Resolution Radiometer (VHRR) sensor were used to provide inputs to these models in addition to global 8 day aerosol optical depth and columnar ozone. Sensitivity analysis of the clear-sky model showed a higher influence of aerosol on global insolation, diffuse insolation, and its fraction as compared with water vapour and ozone. The root mean square error (RMSE) of insolation estimates of the daily integral was found to be 2.05 MJ m^?2 (～11.2% of measured mean) with a high correlation coefficient (r?=?0.93) when compared with in situ measurements during 1 August 2008 to 31 March 2010 over six locations in India. The errors were found to reduce to 7.5% over 3 to 5 day averages. The comparison of annual estimates and equivalent reanalysis fields showed a mean difference of the order of ±1.7 MJ m^?2 over the majority of the Indian landmass.     

Gate and drain SEU sensitivity of sub-20-nm FinFET- and Junctionless FinFET-based 6T-SRAM circuits by 3D TCAD simulation

Scaling of metal–oxide–semiconductor field-effect transistors (MOSFETs) to below a few tens of nanometer has failed to make significant improvements. FinFETs were introduced to replace MOS devices in circuits, offering good performance improvement in the nanoscale regime. Memories occupy a major portion of chip area. Their reliability is a primary concern in harsh environments such as cosmic radiation. Also, in the nanoscale regime, reliability proves to be challenging. We present herein FinFET- and junctionless FinFET-based 6T-static random-access memories (SRAMs) for the 16-nm technology node. In the literature so far, either drain or gate strike has been considered. In this work, we studied irradiation in both the drain and the gate region. The FinFET-based 6T-SRAM showed higher hardness to single-event upset (SEU) radiation in both regions compared to junctionless FinFET-based 6T-SRAM.     

Studies on carbon fibre reinforced aluminium composite processed using pre-treated carbon fibres

Carbon fibre reinforced Al-12% Si alloy composite has been fabricated by pre-treating the fibres with K₂ZrF₆ followed by molten alloy infiltration and subsequent hot pressing of the preforms. The infiltration conditions were arrived at based on the measurement of tensile strength of the fibres extracted from the preforms. The fibre volume per cent of 20 was found to result in composite tensile strength of about 240 MPa as compared to tensile strength of 100 MPa for the unreinforced matrix. Characterization of the interface revealed the formation of ZrSi₂ and diffusion of potassium and aluminium into the fibre. The interfacial bonding was strong as is evinced by the absence of fibre pull-out on to the fracture surface.     

Zinc Titanate Nanofibers for the Detoxification of Chemical Warfare Simulants

Fabrication of a novel ceramic nanofiber system viz. zinc titanate using the well-known electrospinning technology with polyvinylpyrrolidone as a binder is reported. Use of zinc titanates as reactive sorbents to detoxify chemical warfare agents is hypothesized and proved. The zinc titanate nanofibers are tested against simulants of nerve and mustard agents and show satisfactory destructive activity. The extent of detoxification is measured using GC-MS analysis. The products of reaction of zinc titanate against the simulants are identified and are found to be relatively harmless. The possibility of replacement of conventional-activated carbon by electrospun ceramic nanofibers for face masks and protective clothing is proposed.     

Iterated fast local search algorithm for solving quadratic assignment problems

This paper concentrates on multi-row machine layout problems that can be accurately formulated as quadratic assignment problems (QAPs). A genetic algorithm-based local search approach is proposed for solving QAPs. In the proposed algorithm, three different mutation operators namely adjacent, pair-wise and insertion or sliding operators are separately combined with a local search method to form a mutation cycle. Effectiveness of introducing the mutation cycle in place of mutation is studied. Performance of the proposed iterated approach is analyzed and the solution qualities obtained are reported.     

Odd-even oscillations of SHG efficiencies in twin NLO chromophores

Twin NLO chromophores having two azobenzene units linked by a flexible polymethylene spacer of varying lengths are shown to exhibit odd-even oscillations in their second harmonic generation (SHG) efficiencies, when measured in the powder form. These twin systems were designed to also exhibit liquid crystallinity, and indeed most of them do exhibit a nematic mesophase. The anticipated odd-even oscillations, in both their isotropization transition temperatures (Ti) and isotropization entropies (ΔSi), were also observed. The odd-even oscillation of the SHG efficiencies has been ascribed to a more effective cancellation of mesogenic dipoles in the even twins as compared to their odd counterparts, due to a preferred centrosymmetric packing in the former case. Based on the behaviour of these twin chromophoric molecules, it may be anticipated that such odd-even oscillations will also be observed in the analogous main chain NLO polymers. Received: 20 June 1997/Accepted: 22 August 1997     

Role of microorganisms in improving nutritional status of the poor

The intestinal microflora as well as bacteria involved in fermentation of foods ordinarily consumed in India may contribute substantially for the improvement of nutritional status of poor Indians.     

Diffusion bonding of SU 263

Using a specially constructed apparatus, diffusion bonding of SU 263 alloy was studied in the temperature range of 1123–1323 K and compressive stress of 90% of its yield strength at the corresponding temperatures to determine the relative importance of the process parameters, the mechanism(s) responsible for bonding and the joint characteristics. Bond quality was assessed by optical metallography and lap shear testing. The mechanism of bonding was evaluated by grain growth equation. The experimental results were compared with a model developed by Pilling [Pilling, J., 1988. The kinetics of isostatic diffusion bonding in superplastic materials. Mater. Sci. Eng. 100, 137–144] in which the void closure by creep flow and diffusion are considered. Quantified EPMA line scan analysis was carried out to confirm the bonding mechanism and to determine the composition at the interface.     

Microfibres

Microfibres denote synthetic fibres that are finer than any fibre in nature. Microfibres are usually made of polyester, polyamide, acrylic, modal, lyocell and viscose in the range of 0.5-1.2 dtex. The progress starts with direct spinning and post-spinning developments for manufacturing microfibres. Researches on conjugate spinning techniques are reported along with the development in bicomponent spinning. Interesting developments in manufacturing techniques like the change of cross section without altering the spinneret, radial quenching system, etc., have been discussed. Recent developments like electrospinning have also been taken up. The mechanical processing section commences with the properties of microfibres affecting the downstream process and then discusses the processing of microfibres in blow room, carding, draw frame, speed frame and ring frame. Alternative spinning technologies like open-end, air-jet and compact spinning are dealt with. In the fabric forming systems, weaving and knitting with microfibres are discussed in depth highlighting research on such fabrics. High-speed weaving of microfibres is discussed with reference to three major technologies of projectile, rapier and air-jet weaving. The reactions of microfibres to different hydrolysis environments like alkaline, acidic and enzymatic are taken up. Dyeing of microfibres and the specific problems in dyeing of microfibres are discussed. The study of fibre structure by critical dissolution time is addressed. Different uses of microfibres in terms of industrial, medical, apparel and miscellaneous applications are presented. The economics of production along with the limitations and precautions of the fibre are subsequently discussed followed by suggestions for future work.