Authentication systems: A literature review and classification

One of the most important parts of any system is authentication. Appreciated as the first and the last line of defense in the great majority of cases, authentication systems can usually prevent the kleptomaniac from unauthorized accessing to users’ data. However, the traditional text-based password is still used in many websites and applications which are vulnerable to different kinds of attacks. Accordingly, there exist some other alternative ways to boost this traditional method. In this study, we classified and identified different types of authentication systems in a variety of platforms. Their usage, similarity, usability, performance and drawbacks were discussed. The goal of this study is to provide useful, classified information with the aim of understanding of how different authentication systems work and of what their usability and drawbacks are to the readers.     

Modelling of hydrogen production from hydrogen sulfide in geothermal power plants

Geothermal power plants emit high amount of hydrogen sulfide (H₂S). The presence of H₂S in the air, water, soils and vegetation is one of the main environmental concerns for geothermal fields. There is an increasing interest in developing suitable methods and technologies to produce hydrogen from H₂S as promising alternative solution for energy requirements. In the present study, the AMIS technology is the invention of a proprietary technology (AMIS^® - acronym for “Abatement of Mercury and Hydrogen Sulfide” in Italian language) for the abatement of hydrogen sulphide and mercury emission, is primarily employed to produce hydrogen from H₂S. A proton exchange membrane (PEM) electrolyzer operates at 150 °C with gaseous H₂S sulfur dimer in the anode compartment and hydrogen gas in the cathode compartment. Thermodynamic calculations of electrolysis process are made and parametric studies are undertaken by changing several parameters of the process. Also, energy and exergy efficiencies of the process are calculated as % 27.8 and % 57.1 at 150 °C inlet temperature of H₂S, respectively.     

A behavioral change-based approach to energy efficiency in a manufacturing plant

In the realm of industrial energy efficiency studies, very little research has been done to understand the barriers and opportunities to influence behavior of production workers and the corresponding energy-saving potentials. This paper analyzes a case study of Volvo Construction Equipment AB in Braås, Sweden (VCE Braås), that has reduced its relative idle electricity use by more than 10 percentage points during 2013–2016 by implementing a strategy of changing everyday behavior of production workers. The results based on interviews with actors involved in the energy efficiency project showed that a concrete goal, the employment of a fulltime operational leader who earlier worked as a production worker at VCE Braås, and the involvement of both the leadership and employees in project management were key to the success of the project.     

Dependence of Magnetic Hysteresis on Evolving Single-Sample Sintering in Fine-Grained Yttrium Iron Garnet

Mono-dispersed yttrium iron garnet nanoparticles have been synthesized via mechanical alloying technique, and some attendant qualitative relationships between evolving microstructural parameters and magnetic properties have been clearly revealed. A rarely employed single-sample sintering scheme was adopted where only one sample was sintered repeatedly from 600 °C to 1400 °C prior to an analysis of evolution of microstructure-dependent magnetic properties after each sintering. A brief, yet detailed characterization of the sample was carried out using Transmission Electron Microscopy (TEM), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and B–H Hysteresis graph. A scrutiny of the B–H Hysteresis graph results showed a transition from disordered to ordered magnetism which belongs to three different magnetically dominant groups, namely weak ferro-, moderately strong ferro-, and strongly ferromagnetic groups. Three factors were found to strongly influence the ordered magnetism of the sample, namely the crystallinity degree of the crystalline phase, the number of grains with size larger than a critical diameter, and the number of large enough grains for magnetic order accommodation.     

Process simulation and analysis of a five‐step copper–chlorine thermochemical water decomposition cycle for sustainable hydrogen production

A process model of a five‐step copper–chlorine (Cu–Cl) cycle is developed and simulated with the Aspen Plus simulation code. Energy and mass balances, stream flows and properties, heat exchanger duties, and shaft work are determined. The primary reactions of the five‐step Cu–Cl cycle are assessed in terms of varying operating and design parameters. A sensitivity analysis is performed to examine the effect of parameter variations on other variables, in part to assist optimization efforts. For each cycle step, reaction heat variations with such parameters as process temperature are described quantitatively. The energy efficiency of the five‐step Cu–Cl thermochemical cycle is found to be 44% on the basis of the lower heating value of hydrogen, and a parametric study of potential efficiency improvement measures is presented. Copyright © 2014 John Wiley & Sons, Ltd.     

Hybrid online–offline learning to rank using simulated annealing strategy based on dependent click model

Knowledge and Information Systems - Learning to rank (LTR) is the process of constructing a model for ranking documents or objects. It is useful for many applications such as Information retrieval...