A detailed study on the antioxidant activity of the stem bark of Dalbergia sissoo Roxb., an Indian medicinal plant

A detailed study was performed on the antioxidant activity of the aqueous and methanol extracts (AED and MED respectively) of the stem bark of the plant, Dalbergia sissoo Roxb. (Fam. Fabaceae), also known as Indian Rosewood. The antioxidant activity of the extracts was measured by in vitro chemical analyses involving the assays of (1) 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity (2) ferric ion reducing power (3) ferrous ion chelating activity and (4) Au nanoparticle formation potential. A simplified method was developed based on Au nanoparticles formation to assess the antioxidant activity of any plant extract, and was used for the first time to assay the antioxidant activity of AED and MED. In all the assays, AED showed significantly greater activity over MED. This work provides a scientific support for the high antioxidant activity of this plant and thus it may find potential applications in the treatment of the diseases caused by ROS.     

Modeling and validation of heat transfer in packed bed with internal heat generation

Several researchers have modeled the heat transfer in a packed bed, heated externally, and determined its effective thermal conductivity ( $k_{\mathit{eff}}$). But till date, very few researchers have studied the heat transfer of the pebble bed, where the heat is generated inside the bed; and the effective thermal conductivity of the packed bed with internal heat generation has not yet been reported. In the present work, heat generation inside the bed has been imitated by inductively heating randomly placed steel balls with lithium titanate ( ${\text{Li}}_2{\text{TiO}}_3$) pebbles. The system has been modeled and validated with experimental results. The $k_{\mathit{eff}}$ of the ${\text{Li}}_2{\text{TiO}}_3$ pebble bed is determined for various process conditions. A correlation has been developed to calculate the $k_{\mathit{eff}}$ based on various process parameters such as pebble diameter, air flow rate, and induction temperature. The result presented in this study will be used for the design and scale‐up studies of future fusion reactors.     

Drive current boosting of n-type tunnel FET with strained SiGe layer at source

Though silicon tunnel field effect transistor (TFET) has attracted attention for sub-60 mV/decade subthreshold swing and very small OFF current (I_OFF), its practical application is questionable due to low ON current (I_ON) and complicated fabrication process steps. In this paper, a new n-type classical-MOSFET-alike tunnel FET architecture is proposed, which offers sub-60 mV/decade subthreshold swing along with a significant improvement in I_ON. The enhancement in I_ON is achieved by introducing a thin strained SiGe layer on top of the silicon source. Through 2D simulations it is observed that the device is nearly free from short channel effect (SCE) and its immunity towards drain induced barrier lowering (DIBL) increases with increasing germanium mole fraction. It is also found that the body bias does not change the drive current but after body current gets affected. An I_ON of and a minimum average subthreshold swing of 13 mV/decade is achieved for 100 nm channel length device with 1.2 V supply voltage and 0.7 Ge mole fraction, while maintaining the I_OFF in fA range.     

Microstructure and Mechanical Properties of Cryorolled Aluminum Alloy AA2219 in Different Thermomechanical Processing Conditions

Metallurgical and Materials Transactions A - In the present study, aluminum alloy AA2219-T87 bars were cryorolled to various amounts of deformation in two pre-deformation conditions: (1) without...     

润肤剂皮肤感觉性能的评估(英)

研究了不同物理化学结构（分子有无极性、不饱和度、分子链中有无分支及其分支位置和分子的大小等）的性质在皮肤表层的相互作用机理,即润肤剂的皮肤感觉性能。以矿油为参照物,采用原始评价、对比评价和总结评价的评价方法对不同化学结构物质的轻柔感和油亮感进行了详细评估。研究结果表明,物理化学特性明显影响润肤剂的轻柔感和油亮感,例如类似碳氢化合物的非极性物质相对于极性物质要粘稠些;异构烷是轻柔和光滑;带分支链的不     

Reduced graphene oxide-multiwalled carbon nanotubes hybrid film with low Pt loading as counter electrode for improved photovoltaic performance of dye-sensitised solar cells

In this work, the role of reduced graphene oxide (rGO) with hyperbranched surfactant and its hybridisation with multiwalled carbon nanotubes (MWCNTs) and platinum (Pt) nanoparticles (NPs) as counter electrode (CE) were investigated to determine the photovoltaic performance of dye-sensitised solar cells (DSSCs). Sodium 1,4-bis(neopentyloxy)-3-(neopentyloxycarbonyl)-1,4-dioxobutane-2-sulphonate (TC14) surfactant was utilised as dispersing and stabilising agent in electrochemical exfoliation to synthesise graphene oxide (GO) as initial solution for rGO production prior to its further hybridisation and fabrication as thin film. A chemical reduction process utilising hydrazine hydrate was conducted to produce rGO due to the low temperature process and water-based GO solution. Subsequently, hybrid solution was prepared by mixing 1 wt% MWCNTs into the produced rGO solution. TC14-rGO and TC14-rGO_MWCNTs hybrid solution were transferred into fluorine-doped tin oxide substrate to fabricate thin film by spraying deposition method. Finally, the CE films were prepared by coating with thin Pt NPs. Photoanode film was prepared by a two-step process: hydrothermal growth method to synthesise titanium dioxide nanowires (TiO₂ NWs) and subsequent squeegee method to apply TiO₂ NPs. According to solar simulator measurement, the highest energy conversion efficiency (η) was achieved by using CE-based TC14-rGO_MWCNTs/Pt (1.553%), with the highest short current density of 4.424 mA/cm². The highest η was due to the high conductivity of CE hybrid film and the morphology of fabricated TiO₂ NWs/TiO₂ NPs. Consequently, the dye adsorption was high, and the photovoltaic performance of DSSCs was increased. This result also showed that rGO and rGO_MWCNTs hybrid can be used as considerable potential candidate materials to replace Pt gradually.     

Enhanced classification loss functions and regularization loss function (ECLFaRLF) algorithm for bowel cancer feature classification

Multimedia Tools and Applications - Bowel cancer is one of the most common cancers as stated in the bowel cancer cases statistics. The proposed technique is to recognize the pattern of tissue...