Fungal xylanases‐mediated synthesis of silver nanoparticles for catalytic and biomedical applications

Green synthesis of nanoparticles has fuelled the use of biomaterials to synthesise a variety of metallic nanoparticles. The current study investigates the use of xylanases of Aspergillus niger L3 (NEA) and Trichoderma longibrachiatum L2 (TEA) to synthesise silver nanoparticles (AgNPs). Characterisation of AgNPs was carried out using UV–Vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), and transmission electron microscopy, while their effectiveness as antimicrobial, antioxidant, catalytic, anticoagulant, and thrombolytic agents were determined. The colloidal AgNPs was brownish with surface plasmon resonance at 402.5 and 410 nm for NEA‐AgNPs and TEA‐AgNPs, respectively; while FTIR indicated that protein molecules were responsible for the capping and stabilisation of the nanoparticles. The spherical nanoparticles had size of 15.21–77.49 nm. The nanoparticles significantly inhibited the growth of tested bacteria (63.20–88.10%) and fungi (82.20–86.10%), and also scavenged DPPH (37.48–79.42%) and hydrogen peroxide (20.50–96.50%). In addition, the AgNPs degraded malachite green (78.97%) and methylene blue (25.30%). Furthermore, the AgNPs displayed excellent anticoagulant and thrombolytic activities using human blood. This study has demonstrated the potential of xylanases to synthesise AgNPs which is to the best of our knowledge the first record of such. The present study underscores the relevance of xylanases in nanobiotechnology.Inspec keywords: visible spectra, catalysis, ultraviolet spectra, silver, microorganisms, antibacterial activity, transmission electron microscopy, surface plasmon resonance, nanoparticles, nanofabrication, colloids, blood, Fourier transform infrared spectra, particle sizeOther keywords: Ag, fungal xylanases‐mediated synthesis, silver nanoparticles, catalytic applications, biomedical applications, green synthesis, metallic nanoparticles, Trichoderma longibrachiatum L2, transmission electron microscopy, antimicrobial agents, antioxidant agents, catalytic agents, thrombolytic agents, surface plasmon resonance, spherical nanoparticles, FTIR spectra, anticoagulant agents, colloidal nanoparticles, biomaterials, Aspergillus niger L3, UV‐vis spectroscopy, Fourier transform infrared spectroscopy, protein molecules, DPPH, hydrogen peroxide, malachite green, methylene blue, human blood, nanobiotechnology     

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.     

基于DMOS管的电荷灵敏前置放大器设计

提出了一种由DMOS场效应管构成的电荷灵敏前置放大器,可用于硅,Si(Li),CdZnTe及CsI探测器。该前置放大器采用不同于传统的阻容反馈式的电路结构,完全使用MOS管搭建,该前放的设计完成为设计实现ASIC电路准备了技术基础。由Multisi m仿真结果看出该电荷灵敏前置放大器输出信号上升时间小于15ns,并且具有很好的稳定性。     

High-temperature mechanical characterisation of an alumina refractory concrete for Blast Furnace main trough: PART II. Material behaviour

This paper deals with the experimental mechanical characterisation of a high alumina carbon containing refractory concrete at temperatures ranging from room to high temperature (1500 °C). Uniaxial compression, indirect tensile, creep and cyclic loading–unloading tests have been performed. Scale factor effect, influence of interfaces lubrication, material initial heat treatment as well as oxidising or reducing atmosphere test conditions have been investigated. Some of the material mechanical properties have been found to depend not only on the level of applied temperature but also on its duration revealing then the sensible influence of chemical transformation kinetics within the material. An analysis of the global macroscopic mechanical behaviour of the material through the range of temperature is lastly exposed. The data collected are aimed at identifying damage behaviour constitutive equations for numerical simulation of structures built within this material.     

Design and simulation of Gaussian shaping amplifier made only with CMOS FET for FEE of particle detector

The objective of this paper is to design and simulate a shaping amplifier circuit for silicon strip,Si(Li),CdZnTe and CsI detectors,etc.,which can be further integrated the whole system and adopted to develop CMOS-based application,specific integrated circuit for Front End Electronics(FEE) of read-out system of nuclear physics,particle physics and astrophysics research,etc.It's why we used only CMOS transistor to develop the entire system.A Pseudo-Gaussian shaping amplifier made by fourth-order integration stage and a differentiation stage give a result same as a true CR-RC4 filter,we perform shaping time in the range,465 ns to 2.76μs with a low output resistance and the linearity almost good.     

Advanced multicast class-based bandwidth over-provisioning

Dynamic bandwidth aggregate over-provisioning has been proposed to provide differentiated services with scalable Quality of Service (QoS) control. Previous research showed that efficient over-reservation control allows minimizing QoS control overhead with reduced waste of bandwidth and blocking probability. However, existing over-reservation centric solutions are still inefficient in the face of network dynamics, as they are not able to accommodate the dynamic service demands, thus failing to optimize the bandwidth usage. This paper proposes a new Advanced Class-based resource Over-Reservation (ACOR) solution for multicast sessions, which seeks increased network resources utilization while minimizing QoS control overhead. More specifically, ACOR is able to dynamically update the share of bandwidth between different classes of service, providing improved results with less complexity than current solutions. Our analytical and simulation results prove the cost-effective and scalable QoS control capabilities of ACOR in decentralized networks with multiple distributed ingress routers coordinating the QoS control.     

High temperature mechanical characterisation of an alumina refractory concrete for Blast Furnace main trough: Part I. General context

Blast Furnace main trough is an industrial structure submitted to severe high temperature cyclic loading applied on its inner lining made of refractory concrete. The attempt to increase the lifetime of such a structure by numerical simulation requires a proper experimental characterisation of all materials involved and particularly of the refractory concrete. The present paper exposes an analysis of the conditions required for an experimental setup in accountancy with the material working conditions. Then, the development of a performing high temperature mechanical testing device aimed at characterising the castable behaviour in its service conditions is introduced. In particular an original extensometer allowing high temperature direct measurement of the specimen height variation has been developed. Lastly, results of an uniaxiale compression test carried out at intermediate temperature are presented and discussed.     

A low noise charge sensitive preamplifier with switch control feedback resistance

In this paper, the design and analysis of a new low noise charge sensitive preamplifier for silicon strip, Si（Li）, CdZnTe and CsI detectors etc. with switch control feedback resistance were described, the entire system to be built using the CMOS transistors. The circuit configuration of the CSP proposed in this paper can be adopted to develop CMOS-based Application Specific Integrated Circuit further for Front End Electronics of read-out system of nuclear physics, particle physics and astrophysics research, etc. This work is an implemented design that we succeed after a simulation to obtain a rise time less than 3ns, the output resistance less than 94Ω and the linearity almost good.     

Reactivity in [4+2] cycloadditions of new 4-trifluoromethyl-1,3-oxazin-6-ones: Access to functionalized 2-trifluoromethyl pyridines

Recently discovered 4-trifluoromethyl-1,3-oxazin-6-ones react with electron-poor dienophiles as 2-aza-1,3-dienes in Diels-Alder cycloadditions to give new 2-trifluoromethyl pyridines ( 3a – d , 4a – c ). Regioselectivity is excellent in the case of unsymmetrical dienophiles. These new pyridines permit further useful transformations.