Simple and Cost Effective Polymer Modified Gold Nanoparticles Based on Colorimetric Determination of L-Cysteine in Food Samples

The purpose of the present research was to design a method for the colorimetric determination of L-cysteine. We have employed PVA capped gold nanoparticles (GNPs) as a probe. The as-synthesized GNPs were further characterized by UV-vis absorption spectroscopy, transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS) and Zeta potential analyser. The results show that the presence of L-cysteine caused the quenching of the surface plasmon resonance band of the GNPs at 524 nm. It was accompanied by the appearance of a new absorbance of a new absorbance band at 670 nm. The color of the colloidal GNPs changed from wine red to blue. The change in color of the GNPs was due to their aggregation induced by the presence of L-cysteine. Based on these observations, the as-synthesized GNPs were utilized to develop a novel colorimetric sensor for L-cysteine detection in food samples. Significantly, other biomolecules such as alanine, proline, phenylalanine, tryptophane, valine, arginine, glutamic acid, lysine and histidine did not cause any change in the color of the GNPs solutions. This colorimetric probe showed excellent selectivity and high sensitivity for L-cysteine with a detection limit of 2.0 μg mL-1.

Modeling of Abnormal Hysteresis in CsPbBr3 based Perovskite Solar Cells

Perovskite solar cells are emerging photovoltaic devices with PCE of above 25%. Perovskite are suitable light absorber materials in solar cells with excellent properties like appropriate band gap energy, long carrier lifetime and diffusion length, and high extinction coefficient. Simulation study is an important technique to understand working mechanisms of perovskites solar cells. The study would help develop efficient, stable PSCs experimentally. In this study, modeling of perovskite solar cell was carried out through Setfos software. The optimization of different parameters of layer structure of solar cell would help to achieve maximum light absorption in the perovskite layer of solar cell. Simulation study is based drift-diffusion model to study the different parameters of perovskite solar cell. Hysteresis is one of the factors in the perovskite solar cell which may influence the device performance. The measurement of abnormal hysteresis can be done by current-voltage curve during backward scan during simulation study. In backward scan, the measurement starts from biasing voltage higher than open circuit voltage and sweep to voltage below zero. The numerical simulation used to study the various parameters like open circuit voltage, short circuit current, fill factor, power conversion efficiency and hysteresis. The simulation results would help to understand the photophysics of solar cell physics which would help to fabricate highly efficient and stable perovskite solar cells experimentally.

Impact of Melatonin on Growth and Antioxidant Activity of Cicer arietinum L. Grown under Arsenic Stress

The ability of melatonin to regulate number of physiological and biochemical processes under different environmental stresses has been widely studied in plants. So, this investigation was done to study the protective roles of melatonin on Cicer arietinum L. grown under arsenic stress. Subjecting Cicer arietinum L. seeds to arsenic stress caused significant decreases in germination percentage, radicle growth, biomass accumulation, protein content and activities of antioxidant enzymes. On the other hand, melatonin treatment significantly increased growth parameters and protein quantity via improving antioxidant enzyme systems as compared with their corresponding untreated controls.

Investigation on Design and Device Modeling of High Performance CH3NH3PbI3-xClx Perovskite Solar Cells

Perovskite solar cells fabricated with inexpensive and simple technology exhibits high efficiency has witnessed worldwide boom in research. The optimization of solar cell can be done through modeling and simulation. The optical and electrical modeling are the ways to optimize different parameter such as thickness, defect density, doping density and material selection for fabricating stable and highly efficient perovskite solar cells. In this research work, electrical modeling of solar cell is done throughSolar Cell Capacitance Simulator(SCAPS-1D).The architecture of the solar cell is n-i-p device structure. CH3NH3PbI3-xClx acts as light absorber active layer, TiO2 as electron transport layer and Spiro-OMeTADas hole transport layer with device structure FTO/ TiO2/ CH3NH3PbI3-xClx/ Spiro-OMeTAD/Au. The open circuit voltage Voc, short circuit current density Isc, fill factor and power conversion efficiency are 1.28 V, 21.63 mA/cm2, 0.78 and 21.53% respectively. The result showed that the optimize parameter can be applied for fabrication of the solar cell experimentally. Various metal contact materials of the anodeare also studied and analyzed.

Remotely Sensed Image Based on Robust Segmentation and GIS System

The continuous rising abstraction resolution of distant police work sensors sets new interest for applications victimization this information. For mining valuable information from far flung police work data, various classifiers hooked in to the supernatural examination of individual pixels are projected and big advancement has been accomplished. Even so, these methodologies have their restrictions, for the foremost half they manufacture "salt and pepper" boisterous outcomes. to beat such problems, object-arranged image examination strategy hooked in to multi-resolution division methodology was advanced and it's been used for various application functions effectively. During this examination, a productive remotely detected image smart understanding technique hooked in to image division and geographical information framework (GIS) was projected, within the 1st place, division hooked in to mean shift was utilized to amass the underlying parts from distant police work footage. At that time, apply vectorization (Raster to Vector Convertor) strategy to supply polygons from the divided image and highlight attributions, as an example, ghostly, shape, surface then on square measure removed by zonal investigation hooked in to distinctive formation and polygons. At last, creating getting ready take a look at and administered characterization square measure dispensed. just about all means that square measure accomplished in geo-data framework with the exception of image division. supported the investigation, we have a tendency to engineered up a product arrangement of remotely detected image examination. Contrasted and also the understanding methodology of a business programming eCognition, the projected one was gettable and practiced once applied to the Quick bird remotely detected footage.

Determination of Pentachlorophenol in Environmental Samples by Spectrophotometry

Pentachlorophenol (PCP) (2,3,4,5,6- pentachlorophenol) is an organochlorine compound used as a pesticide and a disinfectant. PCP is used as a herbicide, insecticide, fungicide and disinfectant. Some applications include agricultural seeds (for nonfood uses), leather, masonry, wood preservation, cooling tower water, rope, and paper mills. Determination of Pentachlorophenol was based on the reaction of PCP with concentrated nitric acid followed by potassium iodide for the liberation of iodine. Liberated iodine reacted with leuco malachite green for the formation of green colour dye which was measured at 610 nm against a reagent blank. Parameters affecting the reaction were studied. The interfering effect of various species was also investigated and the methods were applied on some vegetables and fruit samples.

Various Techniques of MPPT Based Charge Controller and Comparison of A/C with D/C Home Appliances - A Review

Controlling the PV array to generate the maximum power at certain environment conditions, the efficiency of the PV generation system could be improved. Using control algorithms, the PV array can operate at the maximum power point. This self-optimization process is referred as Maximum power point tracking (MPPT). A maximum power point tracker (MPPT) is a power electronic DC-DC converter inserted between the PV array and its load to achieve optimum matching. Researchers have studied and developed numerous methods and used many algorithms to track the Maximum power point of PV Module and extract maximum power using MPPT technique. This review article accumulates various algorithms through which MPPT could be attained and assists the researchers to understand the principle of their working. The paper also gives an idea to about less explored DC appliances and their viabilities in existing and proposed DC system.

Covid-19 related School Closure Impact on School going Children and Adolescents of Raipur, Chhattisgarh

The Covid-19 induced strict measures like strict lockdown caused schools to be shut down. The classes turned into non-contact and online. This caused children and adolescents to stay at home and take classes from the comfort of their rooms. The lockdown had a positive impact on sleep pattern of children and adolescents as they are not under pressure to wake up early nor they have serious deadlines to submit homework. The data of children and adolescents were collected by the means of questionnaire which was distributed to them. The questionnaire was taken back and analysed. The lack of pressure on students has helped them get positive sleep patterns. Of 44 respondents who took part in the study 68% reported change in sleep time. Out of these 88% were from urban area. Similarly, 57% respondents reported sleeping better during the lockdown and subsequent unlock periods. 68% students experienced that they do not require help in waking up which was around 41% before Covid-19 induced lockdown. This happened because students wake up late as there was no pressure to wake up early. This study again provided evidence in support of late start of school. The policy makers and school administrators should consider the increasing amount of evidence and change the school timings in such a way that student is not forced to wake up too early.

Higher Order Statistics Based Blind Steg analysis using Deep Learning

Universal isteganalysis of grey level JPEG images is addressed by modelling the neighbourhood relationship of the image coefficients using the higher order statistical method developed by two-step Markov Transition Probability Matrix (TPM). The implementation of TPM together with the neighbouring pixel relationship provides a better and comparable detection results. The detection accuracy is evaluated on the stego image database using eXtreme Gradient Boosting (XGBoost) with Principal Component Analysis (PCA) on nsF5 and JUNIWARD hiding techniques. Execution time is also compared for all the classifiers. The images are taken from Green spun library and Google website- eXtreme Gradient Boosting.

Need of Gallium Recovery from Waste Samples: A Review

Gallium is an vital rare metal mainly because of its growing demand in different domain of life. It has wide applications. Gallium is considered as the backbone of the electronics industry. The supply and demand of gallium-bearing products has gradually increased during the past decade. Therefore, from the environmental stand point the need for sensitive and reliable methods for determining trace concentrations of gallium has become apparent in various fields. Gallium has become increasingly popular as a substrate material for electronic devices. Aside from ore, gallium can be obtained from such industrial sources as the Bayer process caustic liquor that is a byproduct of bauxite processing, flue dust removed from the fume-collection system in plants that produce aluminum by the electrolytic process, zinc refinery residues, gallium scrap materials, and coal fly ash. The purification process for gallium can start with solvent-extraction processes where the concentrations of impurities, especially metals, are reduced to the ppm range. The main aim of this paper is to simply put up the salient facts regarding gallium and identify applicable sources of information thereby one may create a suitable environment for the development of methods for the production of gallium via leaching through various waste samples.