Electrocatalysis In Li-S Batteries

Stabilizing polysulfide-shuttle process while ensuring high sulfur loading holds the key to realize high theoretical energy density (2500 Wh/kg) of lithium-sulfur (Li-S) batteries. Though several carbon based porous materials have been used as host structures for sulfur and its intermediate polysulfides, the week adsorption of polysulfides on carbon surface and its poor reaction kinetics limits them from practical application. Here, we preset a novel ‘electcatalysis’ approach to stabilize polysulfide shuttle process and also enhance its red-ox kinetics. As a proof of concept, we have studied in-detail using conventional electrocatalyst i.e Pt/graphene composite, further the same extended to cost-effective electrocatalysts such as WS2 nanosheets and Metal carbides for viable practical applications. Nature of electrocatalyst, concentration of polysulfides, temperature of the cell etc., on electrochemical properties will be discussed. We reveal substantial improvement in electrochemical properties such as specific capacity, rate capability, coulombic efficiency etc. and corroborate our findings with systematic experimental studies. Interaction between electrocatalyst and polysulfides has been evaluated by conducting X-ray photoelectron spectroscopy and electron microscopy studies at various electrochemical conditions. Thus, introducing a catalyst in the Li−S system will open a new avenue for improving electrochemical performance

The Gut Microbiota and Inflammation in Rheumatoid Arthritis

“Mutualism” is a well-defined relationship that describes a form of cooperation between two living organisms of different species that ends up with a beneficial outcome for each one. Any disruption to such a relationship by an external trigger or a potential intruder puts at risk the well-being of both. In humans, oral and gut microbiota provide a noteworthy model of beneficial mutualism. Multiple recent evidences point to the possible pathologic consequences of a disruption to this ecosystem (altered microbiota profile or dysbiosis) on human well-being. The gut-joint axis found its clear way “Proof of Principle” in the pathogenesis of autoimmune rheumatic diseases including rheumatoid arthritis (RA), seronegative spondyloarthropathies, and Behcet’s disease in a number of studies. Current therapeutic trends are directed towards the diverse biologic and immune-pathogenic factors involved in the disease process. Addressing dysbiosis in RA features an attractive future therapeutic target. In this chapter, authors aim to explore the recent evidences regarding the pathogenic role of “gut dysbiosis” in rheumatoid arthritis (RA), highlighting the spectrum of immune-pathogenic events that might contribute to disease evolution and inspecting future directives of research

Fatigue loading characteristic for the composite steel-concrete beams

During the past few decades, composite beams (steel I beam and concrete slab) have had a wide range of uses, particularly in bridge construction. This is due to its relatively low economic cost compared to individual steel structures or reinforced concrete structures. This type of bridges in particular and many similar industrial structures in general are repeatedly subjected to fatigue loads, and that is frequently, as a result of the vehicles passing on these bridges or the vibrations caused by the machines in the industrial facilities. It has been observed during the successive studies that they have been interested in studying this problem that it is concerned with the external structural behavior of these beams  such as a load –deflection relation, observing the cracks appearing during the failure stage and the strain in the steel and concrete flanges. Hence, in this study we have focused on several factors affecting mode of failure of these beams under the fatigue loads, and the common element in all stages of failure was the shear stud, specifically the welding collar at the base of this stud as it is a structurally weak region

Modeling bike counts in a bike-sharing system considering the effect of weather conditions

The paper develops a method that quantifies the effect of weather conditions on the prediction of bike station counts in the San Francisco Bay Area Bike Share System. The Random Forest technique was used to rank the predictors that were then used to develop a regression model using a guided forward step-wise regression approach. The Bayesian Information Criterion was used in the development and comparison of the various prediction models. We demonstrated that the proposed approach is promising to quantify the effect of various features on a large BSS and on each station in cases of large networks with big data. The results show that the time-of-the-day, temperature, and humidity level (which has not been studied before) are significant count predictors. It also shows that as weather variables are geographic location dependent and thus should be quantified before using them in modeling. Further, findings show that the number of available bikes at station i at time t-1 and time-of-the-day were the most significant variables in estimating the bike counts at station i.Comment: Published in Case Studies on Transport Policy (Volume 7, Issue 2, June 2019, Pages 261-268

An Investigation of the Weak Form of the Efficient Markets Hypothesis for the Kuwait Stock Exchange

This article investigates the weak form of the efficient market hypothesis (EMH) for the Kuwait Stock Exchange (KSE). In particular, it tests whether share returns on the KSE exhibit patterns which may be used to predict future share price changes. Ten filter rules are tested on weekly data for 42 firms over the period 1998–2011. The results suggest that the KSE was not weak-form efficient because patterns and trends were present in security prices. In addition, the results are consistent with the substantive literature which has argued that emerging stock markets are informationally inefficient, such as Fifield, Power and Sinclair (2005, 2008) and Xu (2010) and particularly those early studies of Al-Shamali (1989) and Al-Loughani and Moosa (1999) that looked at trading rules for the KSE. </jats:p

Rapidly IPv6 multimedia management schemes based LTE-A wireless networks

Ensuring the best quality of smart multimedia services becomes an essential goal for modern enterprises so there is always a need for effective IP mobility smart management schemes in order to fulfill the following two main functions: (I) interconnecting the moving terminals around the extended indoor smart services. In addition, (II) providing session continuity for instant data transfer in real-time and multimedia applications with negligible latency, efficient bandwidth utilization, and improved reliability. In this context, it found out that the Generalized Multi-Protocol Label Switching (GMPLS) over LTE-A network that offers many advanced services for large numbers of users with higher bandwidths, better spectrum efficiency, and lower latency. In GMPLS, there is an elimination of the routing searches and choice of routing protocols on every core LTE-A router also it provides the architecture simplicity and increases the scalability. A comparative assessment of three types of IPv6 mobility management schemes over the LTE-A provided by using various types of multimedia. By using OPNET Simulator 17.5, In accordance with these schemes, it was proven that the IPv6-GMPLS scheme is the best choice for the system's operation, in comparison to the IPv6-MPLS and Mobile IPv6 for all multimedia offerings and on the overall network performance