•Overall performance of RC is upgraded by using mineral admixtures and steel fiber.•Studied mineral admixtures include silica fume, fly ash, rice husk ash and GGBS.•Studied mechanical parameters ...include compressive strength, splitting tensile strength, modulus of elasticity.•Studied durability parameters include, water absorption, chloride ion penetration and acid attack.
Recycled aggregate concrete (RAC) is now getting much more attention than ever as a likely substitute for natural aggregate concrete, credited to the growing interest of many countries towards the sustainable environment and economy. To increase the goodwill of RAC its performance in terms of strength and durability needs to be optimized. This research article presents the effects of combined incorporation of supplementary cementitious materials (SCMs) and hook-ended steel fibers (HSF) on compressive behavior and durability of RAC. In this study, four different SCMs (i.e. silica fume (SF), ground granulated blast furnace slag (GGBS), fly ash (FA), and rice husk ash (RHA)) were used in RAC with 0% and 1% HSF, respectively. SF, GGBS, FA, and RHA were respectively used as 10%, 30%, 20%, and 15% by mass replacement of ordinary Portland cement (OPC). Studied properties included compressive strength, elastic modulus, splitting tensile strength, water absorption (WA), chloride penetration (CP), and acid attack resistance (AAR). The results of testing indicate that mechanical strength and durability of RAC can be improved substantially by the combined incorporation of SCMs and HSF reinforcement. SCMs show more contribution towards the development of durability properties of RAC, whereas, HSF shows more contribution towards the development of mechanical properties and AAR. 10%SF + 1% HSF and 15%RHA + 1% HSF helped in the production of RAC having superior mechanical and durability properties compared to that of the plain RAC. Moreover, the benefits of combined addition of HSF and SCMs are notably higher than the sum of the benefits achieved through individual incorporation of HSF and SCMs.
Sustainable production of hydrogen is a hopeful requirement of a strategic future economy and development. Water splitting driven by electricity is a favorable pathway for renewable hydrogen ...production. This critical review highlighted recent efforts toward the development of the nanoscale synthesis of nonprecious metal's graphene‐supported electrocatalysts and their electrocatalytic features for remarkable hydrogen evolution reaction (HER). Different essential nonprecious metal's graphene‐supported electrocatalysts, including metal carbides, sulfides, phosphides, selenides, oxides, and nitrides are reviewed. In the exploration, attention is given to the strategies of activity enhancement, the synthetic approach, and the composition/structure electrocatalytic‐performance relationship of these HER electrocatalysts. We are hopeful that this review confers a new momentum to the rational design of remarkable performance nonprecious metal's graphene‐supported electrocatalysts and comprehensive guide for researchers to utilize the subject catalysts in regular water splitting.
Sustainable production of hydrogen is a hopeful requirement of a strategic future economy and development. Water splitting driven by electricity is a favorable pathway for renewable hydrogen production. This critical review highlighted recent efforts toward the development of the nanoscale synthesis of nonprecious metal's graphene‐supported electrocatalysts and their electrocatalytic features for remarkable hydrogen evolution reaction (HER). Different essential nonprecious metal's graphene‐supported electrocatalysts, including metal carbides, sulfides, phosphides, selenides, oxides, and nitrides are reviewed. In the exploration, attention is given to the strategies of activity enhancement, the synthetic approach, and the composition/structure electrocatalytic‐performance relationship of these HER electrocatalysts. We are hopeful that this review confers a new momentum to the rational design of remarkable performance nonprecious metal's graphene‐supported electrocatalysts and comprehensive guide for researchers to utilize the subject catalysts in regular water splitting.
Homozygosity mapping is a powerful method for identifying mutations in patients with recessive conditions, especially in consanguineous families or isolated populations. Historically, it has been ...used in conjunction with genotypes from highly polymorphic markers, such as DNA microsatellites or common SNPs. Traditional software performs rather poorly with data from Whole Exome Sequencing (WES) and Whole Genome Sequencing (WGS), which are now extensively used in medical genetics. We develop AutoMap, a tool that is both web-based or downloadable, to allow performing homozygosity mapping directly on VCF (Variant Call Format) calls from WES or WGS projects. Following a training step on WES data from 26 consanguineous families and a validation procedure on a matched cohort, our method shows higher overall performances when compared with eight existing tools. Most importantly, when tested on real cases with negative molecular diagnosis from an internal set, AutoMap detects three gene-disease and multiple variant-disease associations that were previously unrecognized, projecting clear benefits for both molecular diagnosis and research activities in medical genetics.
Multi-hop relay networks are deployed to restore communication environment in the catastrophe stricken area. Deployment of these networks are fast and easy but performance is low due to the relay ...nature of the networks. Given the surge of bandwidth hungry application, performance such as high data rates, high throughput and ultra-low latency is a concern in traditional one-hop Wireless Local Area Networks (WLANs) as well. Simultaneous transmission over multiple bands is a compendious solution that has the potential to significantly boost data rates and flexibility. It will enhance the network utilization and performance of high-bandwidth applications effectively and efficiently. However, there are certain challenges that need to be addressed before taking full advantage of simultaneous transmission over multiple bands. In this work, we outline the factors affecting the performance such as throughput and end-to-end delay in multiband multi-hop WLANs. Considering these factors, we design an end-to-end traffic scheduling technique that minimizes end-to-end delay and maximizes throughput. We design a mixed integer linear program (MILP) that optimizes end-to-end delay and maximizes throughput. Illustrative numerical results show that proposed technique effectively minimizes end-to-end delay and maximizes throughput.
This note presents an analysis of the state parameterizations used in output feedback reinforcement learning (RL) control. Output feedback algorithms based on state parameterization involve ...additional conditions on the state parameterization beyond the standard conditions on the system matrices for their convergence to the optimal solution. It is shown that the state parameterization matrix needs to be of full row rank to guarantee the convergence of the output feedback RL algorithms. We present conditions in terms of the system matrices and the user-defined observer dynamics that ensure full row rank of the state parameterization matrix.
Approximate dynamic programming (ADP) and reinforcement learning (RL) have emerged as important tools in the design of optimal and adaptive control systems. Most of the existing RL and ADP methods ...make use of full-state feedback, a requirement that is often difficult to satisfy in practical applications. As a result, output feedback methods are more desirable as they relax this requirement. In this paper, we present a new output feedback-based Q-learning approach to solving the linear quadratic regulation (LQR) control problem for discrete-time systems. The proposed scheme is completely online in nature and works without requiring the system dynamics information. More specifically, a new representation of the LQR Q-function is developed in terms of the input-output data. Based on this new Q-function representation, output feedback LQR controllers are designed. We present two output feedback iterative Q-learning algorithms based on the policy iteration and the value iteration methods. This scheme has the advantage that it does not incur any excitation noise bias, and therefore, the need of using discounted cost functions is circumvented, which in turn ensures closed-loop stability. It is shown that the proposed algorithms converge to the solution of the LQR Riccati equation. A comprehensive simulation study is carried out, which illustrates the proposed scheme.
This paper deals with discrete-time models and current control methods for synchronous motors with a magnetically salient rotor structure, such as interior permanent-magnet synchronous motors and ...synchronous reluctance motors (SyRMs). The dynamic performance of current controllers based on the continuous-time motor model is limited, particularly if the ratio of the sampling frequency to the fundamental frequency is low. An exact closed-form hold-equivalent discrete motor model is derived. The zero-order hold of the stator-voltage input is modeled in stationary coordinates, where it physically is. An analytical discrete-time pole-placement design method for two-degrees-of-freedom proportional-integral current control is proposed. The proposed method is easy to apply: only the desired closed-loop bandwidth and the three motor parameters (Rs, Ld, Lq) are required. The robustness of the proposed current control design against parameter errors is analyzed. The controller is experimentally verified using a 6.7-kW SyRM drive.
The main aim of this paper is to introduce and study the generalized Laguerre polynomials and prove that these polynomials are characterized by the generalized hypergeometric function. Also we ...investigate some properties and formulas for these polynomials such as explicit representations, generating functions, recurrence relations, differential equation, Rodrigues formula, and orthogonality. KCI Citation Count: 0
In high-performance control of ac machines through variable frequency drives, the knowledge of machine parameters plays a decisive role. The accuracy with which machine parameters can be known is ...directly related to the time and effort put during the testing and commissioning process. In the ever-demanding industrial environments, the time spent on parameter identification translates into loss of production. To reduce commissioning times, research in this direction has focused on automatizing the identification procedure without loss of accuracy. This paper reviews different lines of research adopted over the past few decades for machine parameter identification. Parameter estimation of ac machines is considered because of their widespread applications from servomechanisms to traction to aviation. The surveyed works include self-commissioning schemes that have become an integral part and a salient feature of modern electric drives. This feature enables the drives to automatically identify machine parameters and tune the control loops.
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•MoP-Mo2C quantum dot heterostructures uniformly distribute on carbon sheet network.•MoP-Mo2C/NPC possesses abundant heterogeneous interfaces and pore structure.•MoP-Mo2C/NPC exhibits ...low overpotentials and ultrahigh stability for HER and OER.
In this work, we constructed MoP-Mo2C quantum dot heterostructures uniformly hosted on a three-dimensional (3D) hierarchically porous thin N,P-doped carbon sheet network (MoP-Mo2C/NPC) by a novel one-pot simultaneous phosphating-carbonization-activation of molybdenum-chelated resin and KOH. Chelate confinement not only prevents the aggregation of MoP/Mo2C quantum dots, but also synchronously produces a carbon sheet network doped with N and P without the requirement for post-atom doping. The prepared MoP-Mo2C/NPC exhibited a large specific surface area, a high electron conductivity, and abundant active sites for the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). As a result, MoP-Mo2C/NPC with a low calculated Gibbs free energy for H adsorption exhibited an excellent electrocatalytic activity and an ultrahigh stability for both the HER and OER processes in an alkaline medium. In addition, the assembled MoP-Mo2C/NPC || MoP-Mo2C/NPC alkaline electrolyzer delivered a current density of 10 mA cm−2 at an overpotential of only 1.55 V, and maintained > 95% of the initial current density after 168 h (1 week) of activity, which is superior to that of the state-of-the-art Pt/C || RuO2/C system in the overall water splitting process.
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