Processing of Mullite–Aluminum Composites

Interconnected-phase mullite–aluminum metal–ceramic composites were processed using the indirect fused-deposition process. In this process, controlled-porosity ceramic preforms were fabricated via the lost-mold process. The molds were designed with computer aided design (CAD) software and fabricated using a fused-deposition modeling (FDM) technique. Porous ceramic preforms were infiltrated with aluminum metal, via pressureless reactive metal infiltration, to form the mullite–aluminum composites. Both the macrostructures and the microstructures of the composites were controlled via CAD and FDM. During metal infiltration, the mullite phase transformed to α-alumina, and an alumina–aluminum composite formed. This paper describes the mullite-to-alumina phase transformation during reactive metal infiltration of the porous preforms, as a function of processing variables.     

Modelling moisture sorption isotherms for maize flour

The sorption isotherm of food material is pertinent in the processing and storage of food products. Adsorption and desorption isotherms for maize flour were investigated using the static gravimetric method over the range of temperature (27–40 °C) and water activity (a_w) (0.10–0.80) commonly experienced in the tropical environment. The experimental data were compared with five widely recommended models in the literature for food sorption isotherms (GAB, modified GAB (MGAB), modified Oswin (MOE), modified Henderson (MHDE), and modified Chung–Pfost (MCE)). The GAB, MGAB, and MOE models were found to be acceptable in predicting the moisture sorption isotherms for maize flour. Overall, the MGAB appears to be most suitable for fitting the adsorption and desorption moisture isotherms data for the maize flour.     

Synthesis and properties of polytriazoleimide containing anthracene,pyridine and 1, 2, 3‐triazole groups and their nanocomposites with titanium dioxide

A novel anthracene, pyridine and 1, 2, 3‐triazole containing diamine was synthesized by copper catalyst 1, 3‐dipolar cycloaddition of azides and alkynes groups (Click reaction). A series of polytriazoleimide (PTAI) nanocomposites were successfully prepared by condensation polymerization between the synthesized diamine monomer and commercially available pyromellitic dianhydride with different weight percentage of titanium dioxide (TiO₂). The structure of the monomer and polymer were confirmed by the fourier transform infrared and nuclear magnetic resonance spectroscopy. The synthesized PTAI is readily soluble in common polar solvents. The PTAIs naocomposites exhibited high thermal stability, the temperature corresponding to a 5% weight loss in the range of 495°C–555°C, excellent flame retardancy (char yield were found to be in the range of 48.1–66.4) and high glass transition temperature (T_g) at (267°C–294°C). Furthermore incorporation of TiO₂ into the PTAI matrix significantly improve the dielectric constant (2.70–4.75 at 1MHz) and dielectric loss (0.06–0.46 at 1 MHz). POLYM. ENG. SCI., 59:129–138, 2019. © 2018 Society of Plastics Engineers     

Double-strand break repair and homologous recombination in Schizosaccharomyces pombe

The study of double-strand break repair and homologous recombination in Saccharomyces cerevisiae meiosis has provided important information about the mechanisms involved. However, it has become clear that the resulting recombination models are only partially applicable to repair in mitotic cells, where crossover formation is suppressed. In recent years our understanding of double-strand break repair and homologous recombination in Schizosaccharomyces pombe has increased significantly, and the identification of novel pathways and genes with homologues in higher eukaryotes has increased its value as a model organism for double-strand break repair. In this review we will focus on the involvement of homologous recombination and repair in different aspects of genome stability in Sz. pombe meiosis, replication and telomere maintenance. We will also discuss anti-recombination pathways (that suppress crossover formation), non-homologous end-joining, single-strand annealing and factors that influence the choice and prevalence of the different repair pathways in Sz. pombe.     

HVD: horizontal-vertical-diagonal error detecting and correcting code to protect against with soft errors

This paper presents a high level error detection and correction method called HVD code to tolerate multiple bit upsets (MBUs) occurred in memory cells. The proposed method uses parity codes in four directions in a data part to assure the reliability of memories. The proposed method is very powerful in error detection while its error correction coverage is also acceptable considering its low computing latency. HVD code is useful for applications whose high error detection coverage is very important such as memory systems. Of course, this code can be used in combination with other protection codes which have high correction coverage and low detection coverage. The proposed method is evaluated using more than one billion multiple fault injection experiments. Multiple bit flips were randomly injected in different segments of a memory system and the fault detection and correction coverages are calculated. Results show that 100% of the injected faults can be detected. We proved that, this method can correct up to three bit upsets. Some hardware implementation issues are investigated to show tradeoffs between different implementation parameters of HVD method.     

Iron Oxide Nanoparticle and Graphene Nanoribbon Composite as an Anode Material for High‐Performance Li‐Ion Batteries

A composite material made of graphene nanoribbons and iron oxide nanoparticles provides a remarkable route to lithium‐ion battery anode with high specific capacity and cycle stability. At a rate of 100 mA/g, the material exhibits a high discharge capacity of ~910 mAh/g after 134 cycles, which is >90% of the theoretical li‐ion storage capacity of iron oxide. Carbon black, carbon nanotubes, and graphene flakes have been employed by researchers to achieve conductivity and stability in lithium‐ion electrode materials. Herein, the use of graphene nanoribbons as a conductive platform on which iron oxide nanoparticles are formed combines the advantages of long carbon nanotubes and flat graphene surfaces. The high capacity over prolonged cycling achieved is due to the synergy between an electrically percolating networks of conductive graphene nanoribbons and the high lithium‐ion storage capability of iron oxide nanoparticles.     

Application of Grid partitioning based Fuzzy inference system method as a novel approach for prediction of interfacial tension of hydrocarbon and carbon dioxide

Nowadays the importance of enhanced oil recovery (EOR) processes increases because of increasing demand of energy and declination of oil reservoirs. Due to this fact the researchers attracted to study performance of EOR methods. one of the high efficient methods is carbon dioxide injection which is favorable because of low cost and environmental friendly viewpoints. One of important parameters which have straight effect on recovery of injection is interfacial tension between carbon dioxide and hydrocarbons. In the present investigation the main objective is proposing the Grid partitioning based Fuzzy inference system method as novel approach to predict interfacial tension of carbon dioxide and hydrocarbon in terms of temperature, pressure, liquid and gas densities and molecular weight of alkane. The coefficients of determination for different datasets of training and testing of estimating algorithm are determined as 0.9919 and 0.9899. This results express the algorithm has potential of estimating interfacial tension of hydrocarbons and carbon dioxide.     

Early web application attack detection using network traffic analysis

International Journal of Information Security - The number of deployed web applications and the number of web-based attacks in the last decade are constantly increasing. One group of tools that...