Search

Cs2AgBiBr6 is a promising lead‐free double perovskite solar cells (PSCs) material. Its full potential has yet to be realized due to issues with its large band gap and the optimization of the alignment of the electron transport layer (ETL) and hole transport layer (HTL). The photovoltaic performance of Cs2AgBiBr6‐based devices has been optimized using ZnO, IGZO, TiO2, WS2, PCBM, and C60 ETLs and Cu2O, CuScN, CuSbS2, NiO, P3HT, PEDOT: PSS, Spiro MeOTAD, CuI, CuO, V2O5, CBTS, and CFTS HTLs. It has been observed by simulation study that Cs2AgBiBr6‐based devices exhibit remarkably high photoconversion efficiency when combined with certain ETLs. To better understand the performance, we examine how the best device structures are affected by the absorber and ETL thickness, ETL carrier density, series and shunt resistance, generation, and recombination rate. The findings suggest that TiO2 and ZnO ETLs, in conjunction with CBTS HTL, exhibit good potential for producing high‐efficiency (η > 13%) Cs2AgBiBr6‐based heterojunction solar cells with an ITO/ETL/Cs2AgBiBr6/CBTS/Au device structure. Optimization of the valence band offset (VBO) at the CBTS/Cs2AgBiBr6 interface reveals that reduced VBO value has a beneficial impact on the performance of the solar cell. This modeling work gives a prospective route for manufacturing lead‐free Cs2AgBiBr6 PSCs. [ABSTRACT FROM AUTHOR]

Miniaturization is governed by the precise and accurate micro-machining operations of various applications. Micro-EDM has emerged as a feasible method for attaining microscale high-precision drilling. The present paper aims to conduct an experimental investigation for drilling micro-holes on copper using the Alumina (Al2O3) powder mixed Micro-EDM technique. Process parameters, including voltage, feed rate, and powder concentration, are varied in experimentation to evaluate their impact on response measures like MRR, TWR, taper angle, and aspect ratio. ANOVA determines the individual contribution of process parameters on each response measure. Voltage is the primary factor influencing MRR (93.5%), TWR (58.24%), and aspect ratio (67.3%), whereas the interaction effect of voltage with powder concentration primarily affects the taper angle (32.36%). Furthermore, the GRA method has optimized the multiple parameters for different responses. The optimum combination of parameters was obtained at a voltage of 125 V, powder concentration of 0.8 g/L, and tool travel speed of 9 µm/s at which better responses are received. The results obtained from FESEM analyses indicate that utilizing alumina (Al2O3) Nano-powder in the dielectric fluid leads to improved effectiveness and reduces the formation of micro-cracks, and micro-voids. Furthermore, the formation of recast layer is reduced by 36.49% as compared to without powder mixed EDM oil during micro-drilling operations. [ABSTRACT FROM AUTHOR]

Genetically encoded optical indicators and actuators of neural activity allow for all-optical investigations of signaling in the nervous system. But commonly used indicators, actuators, and expression strategies are poorly suited for systematic measurements of signal propagation at brain scale and cellular resolution. Large-scale measurements of the brain require indicators and actuators with compatible excitation spectra to avoid optical crosstalk. They must be highly expressed in every neuron but at the same time avoid lethality and permit the animal to reach adulthood. Their expression must also be compatible with additional fluorescent labels to locate and identify neurons, such as those in the NeuroPAL cell identification system. We present TWISP, a transgenic worm for interrogating signal propagation, that addresses these needs and enables optical measurements of evoked calcium activity at brain scale and cellular resolution in the nervous system of the nematode Caenorhabditis elegans. In every neuron we express a nonconventional optical actuator, the gustatory receptor homolog GUR-3 + PRDX-2 , under the control of a drug-inducible system QF + hGR, and a calcium indicator GCAMP6s, in a background with additional fluorophores from the NeuroPAL cell ID system. We show that this combination, but not others tested, avoids optical crosstalk, creates strong expression in the adult, and generates stable transgenic lines for systematic measurements of signal propagation in the worm brain. [ABSTRACT FROM AUTHOR]

Heat is a major stress that severely affects wheat productivity. The objective of the current study was estimating the effect of heat stress during the grain-filling stage for screening heat tolerant wheat genotypes by measuring six stress tolerance indices for grain yield and also measured the % of decline on other important traits. A set of 190 wheat genotypes along with four local checks were evaluated in two separate experiments, one under normal condition (timely sown) and the other under heat stress condition (late sown) in augmented block design at the research farm of Department of Genetics and Plant Breeding, C.C.S. University, Meerut (U.P) during rabi season of 2014-2015. The calculation of % declines revealed that there was a significant decline in the performance of traits under heat stress environment (late sown) in comparison to a normal environment (timely sown). Three traits, namely grain yield/plant, biological yield/plant and grain weight/ spike showed 57.15 %, 53.66 % and 47.73 % decline, respectively under heat stress environment indicating that above mentioned three traits are highly affected by heat stress. To evaluate the susceptible and tolerant genotypes for grain yield under heat stress environment, six stress tolerance indices viz. heat susceptibility index (HSI), mean productivity (MP), tolerance (TOL), stress tolerance index (STI), trait stability index (TSI) and trait index (TI) were calculated based on the grain yield under normal (timely sown) and stress (late sown) environments. The results of correlation between stress tolerance indices and grain yield in normal environment showed a significant positive relationship with MP (0.822**), STI (0.568**), TSI (0.316**), HSI (0.314**), TI (0.188*) and TOL (0.084). However, in stress environment, grain yield showed a significant positive correlation with TI (1.000**), STI (0.907**), MP (0.713**) and TOL (0.129) and negative correlation with HSI (-0.860**) and TSI (-0.808**). Based on the correlation analysis, we have selected four stress indices viz. HSI (heat susceptibility index), MP (mean productivity), STI (stress tolerance index) and TI (trait index) for their use in the selection of heat tolerant wheat genotypes. The results indicated that 9 genotypes (G51, G64, G71, G114, G119, G134, G139, G148 and G150) were heat tolerant and 12 genotypes (G1, G3, G7, G27, G38, G40, G77, G107, G136, G160, G171 and G187) were highly heat susceptible. The genotype G77 was the most heat sensitive genotype while genotype G119 and G139 showed a high yield under heat stress environment. Therefore, genotypes G119 and G139 were identified as a suitable genotype under late sowing environment and can be recommended for heat stress environment. Further, these two genotypes may be also employed in breeding programs aimed for developing heat tolerant varieties of wheat.

Shape memory alloys (SMAs) have become the most common choice for the development of mini- and micro-type soft bio-inspired robots due to their high power-to-weight ratio, ability to be installed and operated in limited space, silent and vibration-free operation, biocompatibility, and corrosion resistance properties. Moreover, SMA spring-type actuators are used for developing different continuum robots, exhibiting high degrees of freedom and flexibility. Spring- or any elastic-material-based antagonistic or biasing force is mostly preferred among all other biasing techniques to generate periodic oscillation of SMA actuator-based robotic body parts. In this model-based study, SMA-based spring-type actuators were used to develop a carangiform-type robotic fishtail. Fin size optimization for the maximization of forward thrust was performed for the developed system by varying different parameters, such as caudal fin size, current through actuators, pulse-width modulation signal (PWM), and operating depth. A caudal fin with a mixed fin pattern between the Lunate and Fork "Lunafork" and a fin area of approximately 5000 mm2 was found to be the most effective for the developed system. The maximum forward thrust developed by this fin was recorded as 40 gmf at an operation depth of 12.5 cm in a body of still water. [ABSTRACT FROM AUTHOR]

The La-Zr/CeO2 (LaxZr0.05Ce1-(x+0.05)O2) materials were synthesized by the green synthesis process using orange peel extract. The identification of the sample's phase, morphology, and functional groups was done by XRD, FE-SEM, and FTIR, respectively. EDX (energy dispersive X-ray spectroscopy) confirmed the elemental identification of materials. The synthesized samples were tested for soot oxidation under loose contact conditions. Thermogravimetric-differential scanning calorimetry (TGA-DSC) characterization was used to test the soot oxidation activity of samples by identifying the loss of weight percent of materials with soot in the temperature range of 100 to 800°C. The materials showed soot oxidation in the temperature range of 362 to 590 °C. The crystallite size of materials was found in the range of 7.5 to 8.3 nm, calculated from Scherrer's equation. The 1% co-doping of La into Zr/CeO2 was found better for soot oxidation than the other synthesized materials. [ABSTRACT FROM AUTHOR]

The chronic exposure of humans to the toxic metal cadmium (Cd), either occupational or from food and air, causes various diseases, including neurodegenerative conditions, dysfunction of vital organs, and cancer. While the toxicology of Cd and its effect on the homeostasis of biologically relevant elements is increasingly recognized, the spatial distribution of Cd and other elements in Cd toxicity-caused diseases is still poorly understood. Here, we use Caenorhabditis elegans as a non-mammalian multicellular model system to determine the distribution of Cd at the tissue and cellular resolution and its effect on the internal levels and the distribution of biologically relevant elements. Using inductively coupled plasma-mass spectrophotometry (ICP-MS), we show that exposure of worms to Cd not only led to its internal accumulation but also significantly altered the C. elegans ionome. Specifically, Cd treatment was associated with increased levels of toxic elements such as arsenic (As) and rubidium (Rb) and a decreased accumulation of essential elements such as zinc (Zn), copper (Cu), manganese (Mn), calcium (Ca), cobalt (Co) and, depending on the Cd-concentration used in the assay, iron (Fe). We regarded these changes as an ionomic signature of Cd toxicity in C. elegans. We also show that supplementing nematode growth medium with Zn but not Cu, rescues Cd toxicity and that mutant worms lacking Zn transporters CDF-1 or SUR-7, or both are more sensitive to Cd toxicity. Finally, using synchrotron X-Ray fluorescence Microscopy (XRF), we showed that Cd significantly alters the spatial distribution of mineral elements. The effect of Cd on the distribution of Fe was particularly striking: while Fe was evenly distributed in intestinal cells of worms grown without Cd, in the presence of Cd, Fe, and Cd co-localized in punctum-like structures in the intestinal cells. Together, this study advances our understanding of the effect of Cd on the accumulation and distribution of biologically relevant elements. Considering that C. elegans possesses the principal tissues and cell types as humans, our data may have important implications for future therapeutic developments aiming to alleviate Cd-related pathologies in humans. [ABSTRACT FROM AUTHOR]

Modern astronomical and advanced wireless communication systems necessitate the utilization of array antennas that provide programmable multibeam capabilities, broadband coverage, high-end coverage range, high gain, reduced side-lobe levels with broader side-lobe level angles, enhanced signal-to-noise ratio, and compact dimensions. This has led to many array antenna theories, including fractal array antennas. In order to enhance comprehension of the operational mechanisms of fractal antennas, an introductory exposition on the underlying theoretical principles is provided. This paper provides an in-depth analysis of current developments in fractal array antenna design. To better understand how fractal antenna function, a primer on the theory behind them is presented. In addition, comparative research of the present state-of-the-art in antenna miniaturisation, gain, and Bandwidth augmentation with fractal array are performed. [ABSTRACT FROM AUTHOR]