Design and Optimization of Full Comparator Based on Quantum‐Dot Cellular Automata

Quantum‐dot cellular automata (QCA) is one of the few alternative computing platforms that has the potential to be a promising technology because of higher speed, smaller size, and lower power consumption in comparison with CMOS technology. This letter proposes an optimized full comparator for implementation in QCA. The proposed design is compared with previous works in terms of complexity, area, and delay. In comparison with the best previous full comparator, our design has 64% and 85% improvement in cell count and area, respectively. Also, it is implemented with only one clock cycle. The obtained results show that our full comparator is more efficient in terms of cell count, complexity, area, and delay compared to the previous designs. Therefore, this structure can be simply used in designing QCA‐based circuits.     

CuIns2/Cus Nanocomposite: Synthesis via Simple Microwave Approach and Investigation Its Behavior in Solar Cell

CuInS₂/CuS nanocomposite were synthesized by a copper complex, [bis(ethylenediamine)copper(ΙΙ)] sulfate. Eight sulfur sources were used for this experiment. The products were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray analysis spectroscopy, and room temperature photoluminescence spectroscopy. Thin film of nanocomposite powder was fabricated and its feature (V_oc, J_sc and FF) was calculated by current–voltage (I–V) curve.     

Pomegranate seed oil as a functional ingredient in beverages

Pomegranate seeds are by‐products of pomegranate juice industry. Since the seeds contain valuable oil that has nutritional and medicinal properties, they can be useful for food applications (especially in juice and beverage industries) as a functional agent. In this study, the possibility of producing a stable pomegranate‐seed‐oil‐in‐water emulsion to be used as a base formula for a new functional beverage was investigated. The influence of gum Arabic (GA) concentration (10.0, 12.5, and 15.0%, w/w) with a constant oil phase content (6.0% w/w) on the turbidity loss rate, emulsion stability index, and droplet size distribution was investigated. Turbidity loss rate was inversely proportional to the GA concentration for all the formulations studied here. Compared to other emulsions, emulsion with 15.0% w/w GA did not show a discernible cream layer during 42 days of storage. Emulsion with 15.0% w/w GA indicated the smallest polydispersity index during this period. The results of this study showed that it was possible to produce a relatively stable pomegranate‐seed‐oil‐in‐water emulsion for use as a functional agent in beverages.     

Improving the quality of surface in polishing process with the magnetic abrasive powder polishing (MAPP) by use of ultrasonic oscillation of work-piece on a CNC table

In this research work, polishing inside, outside and over the cylindrical parts has been done by using a completely new and innovative method. The work-pieces have been placed on a two-axis Cartesian CNC Table for polishing operations. The Magnetic Rotary Head continuously changes its rotation direction from CW to CCW and CCW to CW and meanwhile the part begin to oscillate up-and-down under a High Frequency (20 kHz) conditions. The Frequency of changing direction From CW to CCW and CCW to CW is one of the important parameters in this method. This method is a kind of Ultrasonic Assisted Polishing (UAP) and novelty of this research work is combining this method with motion of work piece under CNC trajectory with continuously changing direction of Magnetic Rotary Head. Gap between Rotary Magnetic Polishing Head and the Work piece Surface can be controlled by a power transmission screw which operates in the direction of the vertical axis. Several experiments have proved high performance of this new proposed method in the process of polishing in short times.     

不同螺栓布置下螺栓连接的滞回性能

从1994年北岭地震中可看到,栓焊节点的抗震性能较差。因此,常用于工业建筑和高层建筑中的抗弯框架多采用端板连接和T型螺栓连接。采用有限元方法,通过改变螺栓的纵横布置对比了14个试件的滞回性能。结果表明:假定两者总的耗能能力相同,则T型螺栓连接的抗弯能力和初始转动刚度均比基于AISC规范设计的端板螺栓连接高。在往复荷载作用下,螺栓布置的改变对T型螺栓连接破坏模式的影响要大于端板连接,端板连接更适用于具有初始几何缺陷的结构。     

Refractory concretes uniaxial compression behaviour under high temperature testing conditions

Two refractory concretes with the same matrix composition, one based on andalusite aggregate and the other on bauxite aggregate, have been studied at temperatures ranging from room temperature to 1200 °C maximal temperature. Samples dried at 110 °C during 24 h to create dried standard specimens and others, fired at different temperatures, were subjected to several uniaxial compression test conditions conducted at various temperatures. The evolution of the materials’ global behaviour from quasi-brittle to viscous was evidenced and correlated to their microstructure evolution. Loading/unloading, creep, and strain rate jump tests helped define the damageable and viscoplastic nature of the behaviour. The influence of the firing temperature and duration on the materials’ behaviour is also reported and discussed. In conclusion, potential constitutive equations that are able to fit the material recorded behaviour are suggested.     

Effect of Immersion Time on Corrosion Behavior of Single-Phase Alloy and Nanocomposite Bismuth Telluride-Based Thermoelectrics in NaCl Solution

The corrosiveness of bismuth telluride-based thermoelectric materials (n-type single-phase alloy and a nanocomposite with MoS₂ nanoinclusions), in 0.1 molar solution of sodium chloride (NaCl), was investigated. The electrochemical impedance spectroscopy curves obtained after 1, 24, 48 and 72 h immersion time revealed the enhancement of the corrosion resistance of the nanocomposite specimen in a 0.1 molar NaCl solution in comparison with the single-phase bismuth telluride-based alloys, and the passivity increased by immersion time up to 72 h. The nanocomposite sample with submicron grains provided suitable nucleation sites for passive film nucleation that led to higher protective behavior.     

Dual-Rotation Speed Friction Stir Welding: Experimentation and Modeling

Implementing differential rotation speeds of pin and shoulder in the friction stir welding process is considered. Experimental investigations were carried out using a newly designed and fabricated apparatus for dual-rotation speed friction stir welding. Metallographic studies demonstrated that appropriate selection of separate pin and the shoulder rotation speeds not only results in defect-free joints, but also affects the weld zone by controlling the heat input delivered. An energy model for predicting maximum temperature was extended to the dual-rotation speed friction stir process. The model was verified using the previous experimental results reported in the literature.     

Opportunistic interference management: a new approach for multiantenna downlink cellular networks

A new approach for multiantenna broadcast channels in cellular networks based on multiuser diversity concept is introduced. The technique called opportunistic interference management achieves dirty paper coding capacity asymptotically with minimum feedback required. When there are K antennas at the base station with M mobile users in the cell, the proposed technique only requires K integer numbers related to channel state information between mobile users and base station. The encoding and decoding complexity of this scheme is the same as that of point‐to‐point communications, which makes the implementation of this technique easy. An antenna selection scheme is proposed at the base station to reduce the minimum required mobile users significantly at the expense of reasonable increase in feedback. In order to guarantee fairness, a new algorithm is presented that incorporates opportunistic interference management into existing Global System for Mobile communications (GSM) standard. Copyright © 2014 John Wiley & Sons, Ltd.