Hierarchical NiMoS and NiFeS Nanosheets with Ultrahigh Energy Density for Flexible All Solid‐State Supercapacitors

Highly flexible supercapacitors (SCs) have great potential in modern electronics such as wearable and portable devices. However, ultralow specific capacity and low operating potential window limit their practical applications. Herein, a new strategy for the fabrication of free‐standing Ni?Mo?S and Ni?Fe?S nanosheets (NSs) for high‐performance flexible asymmetric SC (ASC) through hydrothermal and subsequent sulfurization technique is reported. The effect of Ni²⁺ is optimized to attain hierarchical Ni?Mo?S and Ni?Fe?S NS architectures with high electrical conductivity, large surface area, and exclusive porous networks. Electrochemical properties of Ni?Mo?S and Ni?Fe?S NS electrodes exhibit that both have ultrahigh specific capacities (≈312 and 246 mAh g^?1 at 1 mA cm^?2), exceptional rate capabilities (78.85% and 78.46% capacity retention even at 50 mA cm^?2, respectively), and superior cycling stabilities. Most importantly, a flexible Ni?Mo?S NS//Ni?Fe?S NS ASC delivers a high volumetric capacity of ≈1.9 mAh cm^?3, excellent energy density of ≈82.13 Wh kg^?1 at 0.561 kW kg^?1, exceptional power density (≈13.103 kW kg^?1 at 61.51 Wh kg^?1) and an outstanding cycling stability, retaining ≈95.86% of initial capacity after 10 000 cycles. This study emphasizes the potential importance of compositional tunability of the NS architecture as a novel strategy for enhancing the charge storage properties of active electrodes.     

Experimental investigations on solar chimney for room ventilation

Experimental investigations on a small size solar chimney show that the rate of ventilation increases with increase of the ratio between height of absorber and gap between glass and absorber. This finding is in agreement with results of the steady-state mathematical model developed for analysis of such systems. Nine different combination of absorber height and air gap have been investigated on the experimental set-up. Highest rate of ventilation induced with the help of solar energy was found to be 5.6 air change per hour in a room of 27 m³, at solar radiation 700 W/m² on vertical surface with the stack height-air gap ratio of 2.83 for a 1 m high chimney.     

High-power 1320-nm wafer-bonded VCSELs with tunnel junctions

A new long-wavelength vertical-cavity surface-emitting laser structure is described that utilizes AlGaAs-GaAs mirrors bonded to AlInGaAs-InP quantum wells with an intracavity buried tunnel junction. This structure offers complete wavelength flexibility in the 1250-1650 nm fiber communication bands and reduces the high free-carrier losses and bonded junction voltage drops in previous devices. The intracavity contacts electrically bypass the bonded junctions to reduce threshold voltage. N-type current spreading layers and undoped AlGaAs mirrors minimize optical losses. This has enabled 134/spl deg/C maximum continuous-wave lasing temperature, 2-mW room-temperature continuous-wave single-mode power, and 1-mW single-mode power at 80/spl deg/C, in various devices in the 1310-1340 nm wavelength range.     

A Lightweight Cryptography Technique with Random Pattern Generation

Wireless Personal Communications - The lightweight cryptography (LWC) is an interesting research area in the field of information security. So, different lightweight mechanisms have been developed...     

Establishing relationship between the base metal properties and friction stir welding process parameters of cast aluminium alloys

In friction stir welding (FSW), the material under the rotating action of non-consumable tool has to be stirred properly to get defect free welds in turn it will improve the strength of the welded joints. The welding conditions and parameters are differing based on the mechanical properties of base materials such as tensile strength, ductility and hardness which control the plastic deformation during friction stir welding. The FSW process parameters such as tool rotation speed, welding speed and axial force, etc. play a major role in deciding the weld quality. FSW Joints of cast aluminium alloys A319, A356, and A413 were made by varying the FSW process parameters and the optimum values were obtained. In this investigation, empirical relationships are established and they can be effectively used to predict the optimum FSW process parameters to fabricate defect free joints with high tensile strength from the known base metal properties of cast aluminium alloys.     

Improvement of tea leaves fermentation with Aspergillus spp. pectinase

The pectinase enzymes isolated from Aspergillus spp., A. indicus, A. flavus and A. niveus were used for fermentation of tea leaves. The enzymes were purified and characterized. The effect of both crude enzyme preparation and purified pectinase enzymes on the improvement of tea leaf fermentation were determined in terms of theaflavin, thearubigin, high polymerized substances, total liquor colour, dry matter content and total soluble solids of the tea produced. The crude enzyme preparations obtained from ethanol precipitation were found to be more effective in improving tea leaf fermentation than the purified pectinase enzymes.     

VOID FRACTION PROFILES IN PLANE-POISEUILLE FLOW OF VISCOELASTIC FOAMS

This investigation focuses on slow, isothermal, two-phase flow of gas bubble suspensions in Separan solutions, prepared with the help of a sodium borohydride blowing agent at room temperature. The total residence time in these experiments is much smaller than characteristic times for growth or rise of bubbles. The variation of bubble volume fraction across a narrow gap between two planes, is recorded at two locations along the flow direction. This is done with a Cesium gamma-radiation source focused on a region of area.012 cm² in the flow plane, and a Sodium iodide detector across the channel yielding a resolution of.01 over the range of void fractions investigated from.02 to.08. This measurement allows us to identify conditions under which the two-phase flow may be described by a two fluid model with a uniform bubbly core and a bubble free wall layer. With this two phase flow structure, a relative viscosity equation for the suspension is used to compute an apparent viscosity. Such calculations indicate that the observed reduction in apparent viscosity for the two phase flow may be attributed to a bubbly core which is more shear thinning than the medium. The additional shear thinning factor for the suspension is related to the elasticity of the medium.     

Processing effects in production of composite prepreg by hot melt impregnation

The hot melt impregnation process for producing composite prepreg has been studied. The role of the exit die is highlighted by operating without impregnation bars. Experimental results show that when a fiber two is pulled through a resin bath and then through a wedge shaped die, the total resin mass fraction and the extent of resin impregnation in the two increase with the processing viscosity. The penetration of resin into a fiber bundle is greater when the resin viscosity is higher. This trend is unchanged over a range of two speeds up to the breaking point. A theoretical model is developed to describe the effect of processing conditions and die geometry on the degree of impregnation. Calculations with this model indicate that for a given die geometry, the degree of impregnation increases from 58% to 90% as the ratio of the clearance between the two and the die wall, to the total die gap is decreased from 0.15 to 0.05. Physical arguments elated to the effective viscosity of the prepreg show that the clearance ratio is independent of the two speed, but decreases as the ratio of the effective shear viscosity of the prepareg to the resin viscosity increases. This provides a connection between the experimental results obtained with varying resin viscosity and the computational results obtained with varying clearance values at the die inlet.     

Novel Role of Ghrelin Receptor in Gut Dysbiosis and Experimental Colitis in Aging

Chronic low-grade inflammation is a hallmark of aging, which is now coined as inflamm-aging. Inflamm-aging contributes to many age-associated diseases such as obesity, type 2 diabetes, cardiovascular disease, and inflammatory bowel disease (IBD). We have shown that gut hormone ghrelin, via its receptor growth hormone secretagogue receptor (GHS-R), regulates energy metabolism and inflammation in aging. Emerging evidence suggests that gut microbiome has a critical role in intestinal immunity of the host. To determine whether microbiome is an integral driving force of GHS-R mediated immune-metabolic homeostasis in aging, we assessed the gut microbiome profiles of young and old GHS-R global knockout (KO) mice. While young GHS-R KO mice showed marginal changes in Bacteroidetes and Firmicutes, aged GHS-R KO mice exhibited reduced Bacteroidetes and increased Firmicutes, featuring a disease-susceptible microbiome profile. To further study the role of GHS-R in intestinal inflammation in aging, we induced acute colitis in young and aged GHS-R KO mice using dextran sulfate sodium (DSS). The GHS-R KO mice showed more severe disease activity scores, higher proinflammatory cytokine expression, and decreased expression of tight junction markers. These results suggest that GHS-R plays an important role in microbiome homeostasis and gut inflammation during aging; GHS-R suppression exacerbates intestinal inflammation in aging and increases vulnerability to colitis. Collectively, our finding reveals for the first time that GHS-R is an important regulator of intestinal health in aging; targeting GHS-R may present a novel therapeutic strategy for prevention/treatment of aging leaky gut and inflammatory bowel disease.