Reduction in surface recombination through hydrogen and 1-heptene passivated silicon nanocrystals film on silicon solar cells

We demonstrate reduction in surface recombination by integrating silicon (Si) nanocrystal layer on single crystalline Si solar cell. Si nanocrystals (NCs) are grown by electrochemical etching of (1 0 0) oriented p-type Si wafer. The substructures on the substrate are extracted and passivated it with hydrogen and 1-heptene molecules. Colloidal dispersion of Si NCs was spin casted on solar cell at room temperature. Apart from the I–V curve depicting the efficiency of solar cell, diffuse reflectance, measurement of short circuit current as a function of wavelength and current–voltage characteristics of solar cell were recorded with and without NCs layer. The analysis showed 9.4% increase in Si solar cell efficiency due to the surface passivation effect offered by Si NCs. Measurements of surface recombination time confirms the improved passivation by NCs.     

Experimentation-oriented platform for development and evaluation of MANET cross-layer protocols

We introduce a platform that simplifies the development, performance evaluation, and comparison (DEC) of cross-layer protocols for multi-hop ad hoc networks (MANET). To the best of our knowledge, this is the first platform that provides an integrated API for controlling and assessing, on a per-packet basis, the physical layer and MAC/LLC parameters (e.g. frequency channel, power, rate, coding/modulation, fragmentation, number of retransmissions) for IEEE802.11 network interfaces.Today, performance evaluation of wireless mobile ad hoc networks heavily relies on simulation, which is limited in reflecting real environment scenarios due to the channel modeling approximations. Experimental comparisons of protocols in real-world propagation environment are difficult because of limited reproducibility of the channel propagation, environment, and mobility scenarios. We introduce a DEC platform that provides a network virtualization above the physical/link layers. It runs multiple protocols in TDMA-like timeslots guaranteeing an equitable share of the medium, seamless switching between protocols and synchronization between the nodes, all in a transparent fashion to developers. An extensive experimental evaluation demonstrates the usefulness of the platform.     

An empirical investigation into the effects of web search characteristics on decisions associated with impression formation

It is now common knowledge that information on the World Wide Web is used by people to acquire facts before making decisions—a key activity being forming impressions about other people. Given this, an interesting question arises as to whether and how such impressions may be biased by the characteristics of the information source itself. For instance, in the case of search results about a person, do the quantity and order of results affect the impression formed about the person in question? The question takes on significance considering that these factors may affect decisions of considerable importance and tangible consequence such as those regarding employment, for example, and at the same time, such factors are largely outside the control of the individuals affected. In this paper we refer to searchable digital information about a person on the Web as ePersona, and the impression formed about the person based on the perception as ePerception. Using Web search results, we studied the impacts of order and quantity of results on ePerception using an experiment. Our findings suggest that the order or ranking of results about a search target impacts the impression formed about that target. We also found that the quantity of search results alone does not seem to impact the impression formed.     

A novel augmented reality for hidden organs visualisation in surgery: enhanced super-pixel with sub sampling and variance adaptive algorithm

In recent years, Augmented Reality (AR) has gained more attention as an effective tool in medical surgeries. The potentials of using AR in the medical field can change conventional medical procedures. However, the technology still facing fundamental challenges, especially hidden organs, for example, the organs behind the bowel and liver. The surgeries in these areas lack accuracy in the visualization of the soft tissues behind the bowel and liver like the uterus and gall bladder. This research aims to improve the accuracy of visualisation and the processing time of the augmented video. The proposed system consists of an enhanced super-pixel algorithm with variance weight adaptation and subsampling method. The simulation studies show significant improvements in visualization accuracy and a reduction in processing time. The results show reduced visualisation error by 0.23 mm. It provides better accuracy of the video in terms of visualization error from 1.58?~?1.83 mm to 1.35?~?1.60 mm, and the processing time decreases from 50?~?58 ms/frames to 40?~?48 ms/frames. The proposed system \ focused on the pixel refinement for the 3d reconstruction of the soft tissue, which helps solve the issue of visualising the bowel and liver in an augmented video.

     

Production and characterization of cellobiose dehydrogenase from <Emphasis Type="Italic">Phanerochaete chrysosporium</Emphasis> KCCM 60256 and its application for an enzymatic fuel cell

The enzyme cellobiose dehydrogenase (CDH), with high ability of electron transport, has been widely used in enzymatic fuel cells or biosensors. In this study, the cellobiose dehydrogenase gene from Phanerochaete chrysosporium KCCM 60256 was amplified and expressed in the methylotrophic yeast Pichia pastoris X-33. The recombinant enzyme (PcCDH) was purified using a metal affinity chromatography under non-denaturing conditions. The purified enzyme was analyzed by SDS-PAGE, confirming a corresponding band about 100 kDa. The enzyme activity of this purified PcCDH was determined as 1,845U/L (65mg/L protein). The enzyme showed the maximum activity at pH 4.5 and high activity in broad ranges of temperature from 30°C to 60°C. Moreover, the application of PcCDH to enzymatic fuel cell (EFC) was demonstrated. Lactose was used as the substrate in the EFC system; anode and cathode were immobilized with PcCDH and laccase, respectively. The cell’s open circuit voltage and maximum power density of the EFC system were, respectively, determined as 0.435 V and 314 μW/cm² (at 0.247 V) with 10 mM lactose.     

Sparse multilinear Laplacian discriminant analysis for gait recognition

Pattern Analysis and Applications - Distinct and unique ways of walking have attracted the attention of researchers for identification of different individuals. The Gait; the walking video sequence...     

Synthesis and Characterization of Luminescent Yttrium Oxide Doped with Tm and Yb

Combustion synthesis was used to obtain nanocrystalline Y_{(2− x − y )}Tm _x Yb _y O₃ blue-emitting phosphors. From X-ray diffraction (XRD) it was determined that the powders in the as-synthesized state were in a state of high strain. Upon thermal treatment, the strain in the lattice decreased, which resulted in an improvement in the photoluminescence emission intensity of these phosphors. Fourier-transform infrared spectrometry analysis showed that there is a negligible difference in the absorbed impurities with heat-treatment temperature and time. Hence, it was concluded that the surface impurities do not play a role in the increase in luminescence intensity of these phosphors. The optimum activator concentrations were determined to be approximately x =0.02 and y =0.01.     

Study of thermal comfort in the residents of different climatic regions of India—Effect of the COVID-19 lockdown

Thermal comfort standards are essential to ensure comfortable and enjoyable indoor conditions, and they also help in optimizing energy use. Thermal comfort studies, either climate chamber-based or field investigation, are conducted across the globe in order to ascertain the comfort limits as per the climatic and other adaptive features. However, very few studies are conducted when the occupants are subjected to a stressed condition, like the COVID-19 lockdown, which may not only have the health impacts but also have psychological impacts on the adaptation. In this paper, we present the results of the online study conducted regarding the status of thermal comfort during the COVID-19 lockdown in India. A total of 406 complete responses were collected from subjects located across 3 different climatic regions of India, that is, cold climate, composite climate, and hot and humid climate. Variations in clothing insulation, thermal sensation, and preference were noted across the different climatic regions. We also present the variation in opening of windows and running of fans with the variation in outdoor mean air temperature. The self-judged productivity, comfort, desire to go outdoors, and effectiveness of working from home were seen to vary with the increase in the days of lockdown.     

Direct adaptive torque control for maximizing the power captured by wind turbine in partial loading condition

In this paper, a direct adaptive control approach is used to track the tip speed ratio (TSR) of wind turbine to maximize the power captured during the below rated wind speed operation. Assuming a known optimum value of TSR, the deviation of actual TSR from the optimum one is mathematically expressed as TSR tracking error. Since the actual TSR is not a measurable quantity, this expression for TSR tracking error is linearized and simplified to express it in terms of wind speed and rotor speed, where rotor speed can easily be measured. Although it is possible to measure the wind speed with high accuracy using LiDAR, using it raises the overall cost of wind turbine installation; hence, a method to estimate the wind speed is also proposed. The adaptive controller operates on this simplified TSR tracking error to drive it to zero and to keep the TSR constant at desired optimum value. The performance of the proposed control scheme is illustrated by implementing and simulating it in the National Renewable Energy Laboratory 5MW wind turbine model and comparing the results with the existing baseline fixed gain controller. Copyright © 2015 John Wiley & Sons, Ltd.