Review on nano-and microfiller-based polyamide 6 hybrid composite: Effect on mechanical properties and morphology

Polyamide 6 (PA6)-based composites are of evolving interest due to its high strength, wear resistance, and barrier properties. The use of binary composites mostly with nanomaterial and glass fibers has been reviewed and presented in literature. However to obtain a balance of properties like stiffness, toughness, and strength along with cost reduction, ternary composites of PA6 have been designed. To achieve the balance, PA6 blend-based composites, with combination of microfiller/nanofiller or PA6 with combination micro-microfiller, PA6 with microfiller/nanofiller and fiber have been designed. The properties of PA6-based ternary hybrid composites depend on type of dispersed phase used, presence of compatibilizer, type of filler used (nanofiller or microfiller or fiber or hybrid) and combination of fillers used. However, a review in this direction is not available in literature. Here, in this study, an overall understanding of various fillers, dispersed phase, and their combinations can be understood along with the discussion on effect of these on tensile properties and morphology of hybrid composite. In this study, an attempt has been made to review the various fillers and dispersed phase and their combinations which have been used in designing the PA6 hybrid composite with good balance of stiffness, toughness, and strength.     

HEALTH Growth with Active Transformation of Mind and Body Through Abundant Natural Methods

Wireless Personal Communications - The ongoing technological developments have totally transformed the lives of human beings. With the emergence of the smart era and the smart city concept, a few...     

Exploring relationships between satiation,perceived satiety and plant-based snack food features

We aimed to identify relations between satiation and subsequent satiety for six plant-based foods (apple, avocado, banana, carrot, chick pea and macadamia) using a panel of ten healthy participants and a complete crossover randomised design. Food was served as a mid-morning snack ad libitum over 20 min until participants were comfortably full, and subsequent satiety was monitored for up to 180 min. Carrot and macadamia had significantly higher perceived fullness during eating, but also significantly lower perceived satiety per gram than other foods. Food energy factors had no strong relationship with perceived fullness, but were significantly positively correlated with satiety. Mastication number had significant effects on both perceived fullness (negative) and satiety (positive). This pilot study showed that plant food factors affecting perceived fullness during eating and subsequent satiety are different, and suggests how portion control through satiation for different plant-based snacks may influence both energy intake and subsequent satiety.     

Recovery of copper from a surface altered chalcopyrite contained ball mill spillage through bio-hydrometallurgical route

Bioleaching studies for chalcopyrite contained ball mill spillages are very scarce in the literature. We developed a process flow sheet for the recovery of copper metal from surface activated (600 °C, 15 min) ball mill spillage through bio-hydrometallurgical processing route. Bioleaching of the activated sample using a mixed meso-acidophilic bacterial consortium predominantly A. ferrooxidans strains was found to be effective at a lixiviant flow rate of 1.5 L/h, enabling a maximum 72.36% copper recovery in 20 days. Mineralogical as well as morphological changes over the sample surface were seen to trigger the bioleaching efficiency of meso-acidophiles, thereby contributing towards an enhanced copper recovery from the ball mill spillage. The bio-leach liquor containing 1.84 g/L Cu was purified through solvent extraction using LIX 84I in kerosene prior to the recovery of copper metal by electrowinning. Purity of the copper produced through this process was 99.99%.     

激光焊接热输入对26Cr-3.5Mo铁素体不锈钢组织性能的影响

采用连续激光焊接工艺对26Cr-3.5Mo铁素体不锈钢进行焊接,研究了激光焊接热输入(HI)对焊接接头显微组织和力学性能的影响。采用光学显微镜(OM)、扫描电子显微镜(SEM)、透射电镜(TEM)和能谱分析仪(EDS)研究焊缝显微组织和析出相的析出规律,采用维氏显微硬度仪和拉伸试验机对焊接接头的机械性能进行测试。结果表明,焊缝中心产生细小的等轴晶,随着激光焊接热输入的增加,焊缝中心等轴晶区的宽度增加,其占整个焊缝截面的比例先增加再减小。热影响区(HAZ)宽度较窄,为0.1~0.2 mm,且没有发生明显的晶粒粗化现象。焊接接头HAZ发生软化,其显微硬度值低于焊缝和母材。焊接接头抗拉强度与母材相当,但断后伸长率小于母材,且随激光焊接热输入的增加而减小。     

Distributed Dynamic Backhauling in Aerial Heterogeneous Networks

Wireless Personal Communications - A Wireless Mesh Network (WMN) is a multi-hop network that gains the benefits of low deployment cost, fast access speed, expanded service coverage and large...     

Kinetic analysis of bile salt passage across a dialysis membrane in the presence of cereal soluble dietary fibre polymers

The kinetics of passage of a model bile salt and complete porcine bile across a dialysis membrane, in the presence and absence of two cereal-derived soluble dietary fibre polysaccharides, were studied as a model for passage across the unstirred water layer that lines the small intestine. A first-order kinetic analysis allowed rate coefficients to be derived which quantified the effectiveness of barley mixed linkage β-glucan and wheat arabinoxylan in retarding the transport of bile. For both, a model bile salt and complete porcine bile, rate coefficients decreased with both concentration and viscosity. A combination of viscosity and molecular interaction effects is suggested to control the effect of the two polysaccharides on the transport of bile.     

喀什高台民居:高崖土陶已千年

高台民居位于喀什噶尔老城东北端的悬崖上,两千年前就已存在,一千多年前有维吾尔先民在此建房安家。相传东汉名将班超、耿恭曾在此留下足迹。公元九世纪中期喀什拉汗王朝时,就把王宫建在这个高崖的北面。经过千年历史的发展,高崖上形成了奇特的民居建筑。有意思的是,这里并未     

Structural and microstructural characterizations of nanocrystalline hydroxyapatite synthesized by mechanical alloying

Single phase nanocrystalline hydroxyapatite (HAp) powder has been synthesized by mechanical alloying the stoichiometric mixture of CaCO₃ and CaHPO₄ powders in open air at room temperature, for the first time, within 2 h of milling. Nanocrystalline hexagonal single crystals are obtained by sintering of 2 h milled sample at 500 °C. Structural and microstructural properties of as-milled and sintered powders are revealed from both the X-ray line profile analysis and transmission electron microscopy. Shape and lattice strain of nanocrystalline HAp particles are found to be anisotropic in nature. Particle size of HAp powder remains almost invariant up to 10 h of milling and there is no significant growth of nanocrystalline HAp particles after sintering at 500 °C for 3 h. Changes in lattice volume and some primary bond lengths of as-milled and sintered are critically measured, which indicate that lattice imperfections introduced into the HAp lattice during ball milling have been reduced partially after sintering the powder at elevated temperatures. We could achieve ~ 96.7% of theoretical density of HAp within 3 h by sintering the pellet of nanocrystalline powder at a lower temperature of 1000 °C. Vickers microhardness (VHN) of the uni-axially pressed (6.86 MPa) pellet of nanocrystalline HAp is 4.5 GPa at 100 gm load which is close to the VHN of bulk HAp sintered at higher temperature. The strain-hardening index (n) of the sintered pellet is found to be > 2, indicating a further increase in microhardness value at higher load.