A novel foam glass obtained from solid waste: A sustainable strategy for application in the degradation of an environmental pollutant

Foams glass were obtained from solid waste of flat glass and exhausted alkaline batteries. The physical, chemical, crystalline and morphological properties of the samples were obtained using the Archimedes principle, X-ray diffractometry (XRD), scanning electron microscopy (SEM). The results revealed glass foams with apparent porosities in the range of 55–64% and apparent densities in the range of 0.40–0.79 g cm^?3. The manganese oxide and graphite contained within the cathode of alkaline batteries acted as both oxidizing agents and as foaming agents. The zinc contained in the anode acted as a pore stabilizing agent and the zinc oxide as a semiconductor material. The foam glass that was composed of flat glass with an anode of Zn and ZnO, and a cathode of Mn₂O₃ and Mn₃O₄ (named An8), showed the greatest potential for heterogeneous photocatalysis, with a maximum efficiency of 95.9% after 3 h of treatment of solution containing dye. These results suggest the feasibility of producing foam glass from waste, as well as its potential application in photocatalytic systems, such as in the low-cost treatment of water.     

Influences of gallium substitution on the phase stability,mechanical strength and cellular response of β-tricalcium phosphate bioceramics

β-tricalcium phosphate (β-TCP), a well-accepted synthetic bone grafting biomaterial, is confronted with limitations of poor phase stability and lacking the capacity to mediate the biological functions. In the current study, gallium (Ga) was substituted for calcium in the β-TCP, and the influences of Ga substitution on the phase stability, compressive strength and cellular response of β-TCP bioceramics were investigated. The results indicated that substitution of at least 2.5 mol% Ga for calcium prevented the β-TCP from transforming into α-TCP at 1250 °C. The β-TCP bioceramics substituted with 2.5 mol% Ga attained the highest compressive strength. The β-TCP bioceramics substituted with 2.5 and 5 mol% Ga showed good cytocompatibility, and suppressed in vitro osteoclastic activity as well as osteoblastic differentiation. Considering the favorable mechanical strength and the inhibitory effect on the osteoclastic activity, the β-TCP bioceramics substituted with 2.5 mol% Ga are promising for treating the bone defect in the pathological state of excessively rapid bone resorption.     

Secure and reliable data communication in developing regions and rural areas

Nowadays, despite the ever increasing need of people for staying “connected” at any time and everywhere, in many areas of the world data connection is extremely expensive or even absent. The Global System for Mobile Communication (GSM) network virtually covers all the populated areas of the world and on average, the entire world population have a handheld device capable of accessing at least the GSM services. Therefore, it makes sense to consider the Short Message Service (SMS) as the most popular wireless data service for such devices. In this work, we exploit the SMS as mechanism for data transfer, especially in scenarios where there is no other network coverage than GSM, such as in rural areas and developing regions. In particular, we propose a framework, based on the SMS as transport facility, which enables secure end-to-end data communication in a ubiquitous and pervasive manner. Moreover, we investigated how, by using compression techniques, the overall processing and transmission efforts needed for secure data communication can be effectively reduced, with the obvious consequences also in terms of energy consumption on the involved devices. Finally, we successfully tested the effectiveness of the proposed framework within the context of a proof of concept implementation.     

Energy-optimal base station density in cellular access networks with sleep modes

Sleep modes are widely accepted as an effective technique for energy-efficient networking: by adequately putting to sleep and waking up network resources according to traffic demands, a proportionality between energy consumption and network utilization can be approached, with important reductions in energy consumption. Previous studies have investigated and evaluated sleep modes for wireless access networks, computing variable percentages of energy savings. In this paper we characterize the maximum energy saving that can be achieved in a cellular wireless access network under a given performance constraint. In particular, our approach allows the derivation of realistic estimates of the energy-optimal density of base stations corresponding to a given user density, under a fixed performance constraint. Our results allow different sleep mode proposals to be measured against the maximum theoretically achievable improvement. We show, through numerical evaluation, the possible energy savings in today’s networks, and we further demonstrate that even with the development of highly energy-efficient hardware, a holistic approach incorporating system level techniques is essential to achieving maximum energy efficiency.     

Updated thoughts on SARS-CoV-2 and coronavirus therapies,fighting and surviving

From late December 2019 a new human-adapted coronavirus, SARS-CoV-2, was observed and isolated in clustered patients in Wuhan, China. It has been proved to be able to transmit human-to-human and cause pneumonia, leading to about 2% fatality. Its genome characteristics, immune responses and related potential treatments, such as chemical drugs, serum transfusion and vaccines including DNA vaccines, are discussed in this review for a brief summary.     

回转角对AZ31镁合金管材冷轧成形过程的影响

回转角是三辊式冷轧无缝管材过程中的关键工艺参数,本文以冷轧AZ31镁合金管材为研究对象,通过对不同回转角下的冷轧过程进行了完整的仿真,对比分析了不同回转角在各特征变形段对等效应力、等效塑性应变及节点温度的影响规律,结果表明随着回转角的增大,等效应力、等效塑性应变以及节点温度均增大。借助元胞自动机模型以及实验等手段,通过实验与数值仿真结果对比分析,探明了晶粒在轧制过程中产生连续再结晶并细化的初步组织演变规律,获得了50°的回转角可以更好的满足工艺要求,为镁合金管材冷轧成形回转角的选择提供依据。     

轧制速度对AZ31镁合金管材冷轧成形的影响

轧制速度是三辊式冷轧成形过程中关键的工艺参数，决定其力学特征及温升情况。基于此，本文以冷轧AZ31镁合金管材为研究对象，通过全流程数值仿真计算，对比分析不同轧制速度在各特征变形段对等效应力、等效塑性应变及节点温度的影响规律。结果表明，等效应力、等效塑性应变及节点温度均随轧制速度的增大而增大。通过元胞自动机模型及实验等手段，探明了晶粒在轧制过程中产生连续再结晶并细化的初步组织演变规律；对比分析实验与模拟结果并结合多方面因素，得到800mm/s的轧制速度可以更好的满足工艺要求的结果，为冷轧镁合金管材轧制速度的选择提供依据。     

Numerical simulation of detonation wave propagation through a rigid permeable barrier

The results of calculation of the detonation propagation in a porous medium for hydrogen-air mixture are presented. The porous medium was specified explicitly and consisted of sets of individual obstacles in the form of solid walls or the sets of finite-size plates. Various modes of detonation propagation depending on obstacle parameters are obtained: propagation in a cellular mode, stationary propagation with destruction of the cellular structure of the detonation front, propagation of a monotonically attenuating detonation wave with destruction of the cellular structure of the front. The possibility of reducing the detonation propagation velocity by replacing solid plates with finite-size ones was shown. The effect of the geometrical parameters of the plates and the step of it installation on the degree of detonation attenuation was estimated. It was determined that an increase in the number of plates leads to a stronger attenuation of the detonation.     

岩石断裂演化过程元胞自动机模型的研究

提出了一种研究岩石断裂演化过程的元胞自动机模型。通过大量模拟发现，岩石断裂演化过程是岩石内部微裂隙萌生、扩展、聚集和贯通的的过程，大量微裂隙的集体行为具有特定的规律。在岩石断裂演化过程中，微裂隙的空间分布是一个分级维形态的生长过程，岩石内完整岩石微元的空间分布是一个降维过程。岩石断裂隙化过程是一个确定性和随机性统一的过程，其中的分形物理机制是研究的关键。