Non-repeatered 50 km transmission experiment using low-loss optical fibres

An optical transmission experiment with an extremely long repeater spacing is conducted using graded-index multimode fibres, an InGaAsP/InP laser diode and a germanium avalanche photodiode A 53 3 km repeater spacing is realised by this experimental 1 27 ?m wavelength     

Adapting automation to man, culture and society

Anxiety about the effects of automation on workers and society is at least 150 years old. The recent explosion of microelectronics and robotic applications has sharpened our understanding of both the gains and the risks: mismatch to human physiological, psychological and cultural characteristics; alienation from fulfillment and dignity in work; widening of the gap between skilled and unskilled workers and between technologically developed and underdeveloped communities; decrement in individual security. Attention to these problems can ensure that automation results in a better society. The control engineer, who is responsible for enlarging the scale of automation, should also play a role in adapting it to people. For the time being, technology should be individually designed to each culture.     

Covalent organic frameworks (COFs) quantum dots as supramolecular cages modified with biochar as nanobio photocatalyst for degradation of organic dyes

In this study, we used co-precipitation assisted solvothermal route to produce self-assembled covalent organic frameworks (COFs) quantum dots modified with biochar structures. In addition, photocatalytic degradation of organic dyes such as methyl red, methyl orange and methyl blue were measured without the need to artificial UV visible light in vitro condition, and degradation rate was estimated at alternate times. The biochar as precursor agent with hydrothermal method as an eco-friendly synthesis route used to provides COFs quantum dot nanostructures with appropriate diameter and size about 3.68 nm. This research presents a new and novel nanocomposite structures with the contribution of biochar as biological material for decolorization of methylene red, orange and blue were calculated using UV–vis spectroscopy. Novel covalent organic frameworks quantum dot membranes with high purity were synthesized and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transition electron microscopy (TEM), Atomic force microscopy (AFM), Fourier transformed infrared spectrum (FT-IR), thermo-gravimetric analysis (TGA), differential scanning calorimetry (DSC) and Brunauer–Emmett–Teller (BET) surface area analysis. Results clearly indicate which self-assembled COFs quantum dots as supramolecular cages modified with biochar synthesized with the cost-effective method act as a high performance photocatalyst for degradation of methylene red, orange and blue organic dyes.

     

Effects of EPDM‐g‐MAH compatibilizer and internal mixer processing parameters on the properties of NR/EPDM blends: An analysis using response surface methodology

This study evaluates the effects of ethylene‐propylene‐diene‐monomer grafted maleic anhydride (EPDM‐g‐MAH) and internal mixer melt compounding processing parameters on the properties of natural rubber/ethylene‐propylene‐diene rubber (NR/EPDM) blends. Using Response Surface Methodology (RSM) of 2⁵ two‐level fractional factorial, we studied the effects of NR/EPDM ratio, mixing temperature, Banbury rotor speed, mixing period, and EPDM‐g‐MAH contents in NR/EPDM blends. The study found that the presence of EPDM‐g‐MAH in NR/EPDM blends had a predominant role as a compatibilizing agent, which affected the processability and properties of the final material. We also determined the model fitting with constant determination, R² of 99.60% for tensile strength (TS) response with a suggested combination of mixing process input parameters. The reproducibility of the proposed mixing strategy was then confirmed through model validation with a minor deviation at +2.303% and higher desirability of 0.960. This study is essential in providing a process design reference for NR/EPDM blends preparation by melt‐blending and the role of a compatibilizer from the systematic Design of Experiment (DOE) approach. The experimental findings were further supported with swelling and cross‐link density measurements, differential scanning calorimetry analysis, and observation of fracture morphology using a scanning electron microscope. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42199.     

A conceptual framework for the collection of food products in a Total Diet Study

A total diet study (TDS) provides representative and realistic data for assessing the dietary intake of chemicals, such as contaminants and residues, and nutrients, at a population level. Reproducing the diet through collection of customarily consumed foods and their preparation as habitually eaten is crucial to ensure representativeness, i.e., all relevant foods are included and all potential dietary sources of the substances investigated are captured. Having this in mind, a conceptual framework for building a relevant food-shopping list was developed as a research task in the European Union’s 7th Framework Program project, ‘Total Diet Study Exposure’ (TDS-Exposure), aimed at standardising methods for food sampling, analyses, exposure assessment calculations and modelling, priority foods, and selection of chemical contaminants. A stepwise approach following the knowledge translation (KT) model for concept analysis is proposed to set up a general protocol for the collection of food products in a TDS in terms of steps (characterisation of the food list, development of the food-shopping list, food products collection) and pillars (background documentation, procedures, and tools). A simple model for structuring the information in a way to support the implementation of the process, by presenting relevant datasets, forms to store inherent information, and folders to record the results is also proposed. Reproducibility of the process and possibility to exploit the gathered information are two main features of such a system for future applications.     

基于FPGA和SHT21传感器的温湿度测量系统的设计

设计了一种以XC2S50型现场可编程门阵列(FPGA)和SHT21温湿度传感器为核心的数字温湿度测量系统;利用FPGA为核心实现对数字式温湿度传感器SHT21的通信控制,测量的数据通过上位机软件进行显示;系统设计使用VHDL语言设计,实现了性能和成本的最大平衡;测试结果表明,本系统不仅能够准确的测量出实时温湿度数据,还能快速反应周围温度环境的实时变化,并且达到了系统温度精确度要求的0.001℃。     

Influence of precursor source on sol–gel deposited ZnO thin films properties

Zinc oxide thin films were deposited by sol gel technique on glass substrates using different precursors (zinc acetate, zinc nitrate and zinc chloride). In the present work we investigate the precursor nature influence on structural, morphological, optical, electrical properties and photocatalytic activity of ZnO thin films. For this purpose we have used X-rays diffraction (XRD), atomic force microscopy (AFM), UV–visible spectroscopy and Hall effect measurements for films characterization. The obtained results indicated that ZnO films properties are strongly influenced by the nature of the used precursor as reactant. Films photocatalytic activity was evaluated by the photo-degradation of methylene blue (MB) dissolved in aqueous solution under UV-A light. The obtained results indicated that ZnO thin films prepared from zinc acetate are more efficient than those prepared from zinc nitrate and zinc chloride.     

共振隧穿二极管的压阻特性测试与研究

设计并搭建了检测共振隧穿二极管(RTD)压阻特性的实验系统,测试了RTD结构在不同应力状态下I-V特性曲线的漂移.实验结果表明RTD结构压阻特性的灵敏度大于1×10-8Pa-1.为了更精确地定量表达其压阻特性,研究了同一RTD结构I-V特性的一致性,得到相同环境条件下RTD电阻的最大相对漂移量小于3%,其中1%由测试仪器造成.     

Performance of limestone-based sorbent for sorption-enhanced gasification in dual interconnected fluidized bed reactors

A possibility to carry out sorption-enhanced gasification (SEG) is represented by its integration with the calcium looping concept in dual interconnected fluidized beds (DIFB). This article is focused on the sorbent CO₂ uptake performance and attrition/fragmentation tendency when operating conditions simulating those of a DIFB-SEG process are adopted. Experiments were carried out on a commercial Italian limestone in a laboratory-scale DIFB reactor. Carbonation was carried out in a range of test conditions, including variable temperature (600–700°C) and absence/presence of steam (10% by volume); CO₂ concentration was set at 10% by volume. The characterization is extended by investigating the behavior of preprocessed DIFB-SEG samples on impact fragmentation tests, conducted in an ex situ apparatus. Tests were carried out for impact velocities in the range 17–45 m/s. Results were discussed considering both the impact velocity value and the operating conditions under which the sample was preprocessed in the fluidized bed.