Grid to wheel energy efficiency analysis of battery‐ and fuel cell–powered vehicles

Sustainable energy consumption is an important part of the renewable energy economy as renewable energy generation and storage. Almost one‐third of the global energy consumption can be credited to the transportation of goods and people around the globe. To move towards a renewable energy–based economy, we must adopt to a more sustainable energy consumption pattern worldwide especially in the transportation sector. In this article, a comparison is being made between the energy efficiency of a fuel cell vehicle and a battery electric vehicle. A very simple yet logical approach has been followed to determine the overall energy required by each vehicle. Other factors that hinder the progress of fuel cell vehicle in market are also discussed. Additionally, the prospects of a hydrogen economy are also discussed in detail. The arguments raised in this article are based on physics, economic analyses, and laws of thermodynamics. It clearly shows that an “electric economy” makes far greater sense than a “hydrogen economy.” The main objective of this analysis is to determine the energy efficacy of battery‐powered vehicles as compared to fuel cell–powered vehicles.     

Mott–Schottky analysis of passive films on Cu containing Fe–20Cr–xCu (x = 0, 4) alloys

Effect of copper on the defect density of Fe–20Cr–xCu (x?=?0, 4) stainless steel alloys was investigated in deaerated pH 8·5 borate buffer solution at room temperature using Mott–Schottky analysis. Mott–Schottky analysis revealed that the addition of copper increased the acceptor density (N_A, V_Cr^?3), i.e. decreased the Cr⁺³ content of the passive film. Also the donor densities, shallow donor (N_D1, V_O⁺²) and deep donor (N_D2, V_Cr⁺⁶), of the passive films formed were increased. XPS analysis confirmed the decrease in Cr content and enrichment of copper in the passive film of Cu containing alloys, which ultimately dictated their lower corrosion resistance, i.e. decreased film protectiveness and stability.     

Ensembling Downscaling Techniques and Multiple GCMs to Improve Climate Change Predictions in Cryosphere Scarcely-Gauged Catchment

Future projections of climate variables are the key for the development of mitigation and adaptation strategy to changing climate. However, such projections are often subjected to large uncertainties which make implementation of climate change strategies on water resources system a challenging job. Major uncertainty sources are General Circulation models (GCMs), post-processing and climate heterogeneity based on catchment characteristics (e.g. scares data and high-altitude). Here we presents the comparisons between different GCMs, statistical downscaling and bias correction approaches and finally climate projections, with the integration of gridded and converted (monthly to daily) data for a high-altitude, scarcely-gauged Jhelum River basin, Pakistan. Current study relies on climate projections obtained from factorial combination of 5-GCMs, 2 statistical downscaling and 2 bias correction methods. In addition, we applied bias corrected APHRODITE, converted daily data using MODAWEC model and observed data. Further, five GCMs (CGCM3, HadCM3, CCSM3, ECHAM5 and CSIRO-MK3.5) were tested to scrutinize two suitable GCMs integrated with Statistical Downscaling Model (SDSM) and Smooth Support Vector Machine (SSVM). Results illustrate that the CGCM3 and HadCM3 were suitable GCMs for selected study basin. Both downscaling techniques are able to simulate precipitation, however, SSVM performed slightly better than SDSM. We found that the integration of CGCM3 with SSVM (SSVM-CGCM3) generates precipitation and temperature better than the CGCM3 (SDSM-CGCM3) and HadCM3 (SDSM-HadCM3) with SDSM. Furthermore, the low elevation stations were influenced by monsoon, significantly prone to rise in precipitation and temperature, while high-altitude stations were influenced by westerlies circulations, less prone to climate change. The projections indicated rise in basin-wide annual precipitation by 25.51, 36.76 and 45.52 mm and temperature by 0.64, 1.47 and 2.79 °C, during 2030s, 2060s and 2090s, respectively. The methods and results of this study can be adopted to evaluate climate change implications in the catchments of characteristics similar to Jhelum River basin.     

Hot corrosion behavior of double ceramic layered CaZrO3/Yttria‐stabilized zirconia coatings

A novel double ceramic layered (DCL) CaZrO₃/Yttria‐stabilized zirconia (YSZ) thermal barrier coatings (TBCs) was designed for improved service life against sulfate vanadate hot corrosion as compared with that of YSZ single layered coating. The hot corrosion behavior of DCL CaZrO₃/YSZ coatings was studied at 950°C after dry spreading 50%Na₂SO₄+50%V₂O₅ mixture onto a coated surface. The CaZrO₃ as the topmost layer in DCL CaZrO₃/YSZ coatings, served as a sacrificial layer during sulfate vanadate hot corrosion protecting the underneath YSZ coating. The corrosion reactions in this case were sluggish due to the initial formation of low melting point meta‐calcium vanadate (CaV₂O₆) that isothermally transformed to higher melting point calcium vanadates having higher calcia (CaO) content. The corrosion reaction products sealed the top surface, impeding the oxygen movement and eventually retarded the thermally grown oxide (TGO) growth. The sulfate vanadate hot corrosion life of the DCL CaZrO₃/YSZ coatings was observed to be more than double as compared with single ceramic layered YSZ coatings.     

Quality Management in Pakistan's Knitwear Industry

Although quality is a critical success factor for all types of business, its salience is to be driven home in Pakistan's business environment in general and its export-oriented business segment in Pakistan in particular. As a first part of this effort, we chose to study quality management in Pakistan's knitwear industry, whose combined share with readymade garments in Pakistan's total exports rose to 16.7% by 1997/1998. We mailed a postal self-completion questionnaire to 59 members of the Pakistan Knitwear and Sweaters Exporters Association. The response rate was 29%. It was found that Pakistan's knitwear industry was in various stages of development in quality management, with greater concentration in the quality inspection mode. Although there are attempts to graduate to quality assurance and beyond, it was found that considerable distance has yet to be traversed before Pakistan's knitwear industry acquires a quality philosophy as a part of its overall business approach industrywide. As part of a statistical test, however, advanced quality management concepts were found applicable in Pakistan, although the application is currently limited. These concepts must gain in popularity.     

New job selection and location policies for load‐distributing algorithms

This paper presents a new distributing algorithm that uses new job selection and location policies. The algorithm is shown to outperform the best‐reported load distributing algorithms. Copyright © 2002 John Wiley & Sons, Ltd.     

Resource Allocation Schemes in D2D Communications: Overview,Classification, and Challenges

Device-to-Device (D2D) communications is predicted to be a major part of 5G wireless communications due to its benefits such as flexible connectivity and unloading of traffic burden off the cellular networks. However, interference scenarios in D2D communications are usually more complicated than conventional wireless communications, e.g., spectrum reuse is commonly involved in D2D communications, especially when it works as an underlay. Therefore, how to coordinate the challenges of significant interference with the demand of higher data rates under the constraints of efficient energy consumption and spectrum utilization has become a haunting problem in our way to the ideal performance of wireless communications system. The solution resides in multiple resource allocation techniques in D2D communications as each of them attempts to solve or optimize one or several essential elements in the system. In this paper, a survey of resource allocation schemes in D2D communications is presented. We discuss the optimization classification including objectives, constraints, problem types and solutions. This paper also highlights system characteristics. Finally, future research challenges are outlined.     

Joint design of QC-LDPC codes for coded cooperation system with joint iterative decoding

In this paper, we investigate joint design of quasi-cyclic low-density-parity-check (QC-LDPC) codes for coded cooperation system with joint iterative decoding in the destination. First, QC-LDPC codes based on the base matrix and exponent matrix are introduced, and then we describe two types of girth-4 cycles in QC-LDPC codes employed by the source and relay. In the equivalent parity-check matrix corresponding to the jointly designed QC-LDPC codes employed by the source and relay, all girth-4 cycles including both type I and type II are cancelled. Theoretical analysis and numerical simulations show that the jointly designed QC-LDPC coded cooperation well combines cooperation gain and channel coding gain, and outperforms the coded non-cooperation under the same conditions. Furthermore, the bit error rate performance of the coded cooperation employing jointly designed QC-LDPC codes is better than those of random LDPC codes and separately designed QC-LDPC codes over AWGN channels.