Design and adaptation of a novel supercritical extraction facility for operation in a glove box for recovery of radioactive elements

The design and development of a novel supercritical extraction experimental facility adapted for safe operation in a glove box for the recovery of radioactive elements from waste is described. The apparatus incorporates a high pressure extraction vessel, reciprocating pumps for delivering supercritical fluid and reagent, a back pressure regulator, and a collection chamber. All these components of the system have been specially designed for glove box adaptation and made modular to facilitate their replacement. Confinement of these materials must be ensured in a glove box to protect the operator and prevent contamination to the work area. Since handling of radioactive materials under high pressure (30 MPa) and temperature (up to 333 K) is involved in this process, the apparatus needs elaborate safety features in the design of the equipment, as well as modification of a standard glove box to accommodate the system. As a special safety feature to contain accidental leakage of carbon dioxide from the extraction vessel, a safety vessel has been specially designed and placed inside the glove box. The extraction vessel was enclosed in the safety vessel. The safety vessel was also incorporated with pressure sensing and controlling device.     

A simple and sensitive apparatus for measuring the magnetization of small ferrite samples

This paper describes an apparatus which allows the routine measurement of the magnetization of small ferrite samples using the well-known extraction method. In contrast to the classical extraction method, however, this device makes use of a high-permeability magnetic circuit that serves both to apply the bias field and to collect the sample flux. This design, together with a signal sampling technique, allows an unusually high sensitivity for this type of method (magnetic moment resolution is 5 x 10(-5) microem). The apparatus is described in detail and a brief theory of its function is given. Finally, the device usefulness is illustrated by some measurement results referring to Ga YIG spheres that are used in ferrimagnetic resonators.     

High-pressure apparatus for dielectric measurements in high frequency

The present article describes an experimental apparatus for the measurement of low-loss dielectric material under conditions of high pressures (maximum pressure 1500 bars) and high frequencies (1-15 MHz.) The measurements of these losses are based on the classical method of the Q-meter with a general Radio type 1690-A sample holder, located in a high-pressure bomb. All the manual operations made on the holder during the measurements are controlled by dc motors. The first results have shown that the dielectric losses of polyethylene (PE) vary with the pressure. This apparatus will later be used in the measurement of the dielectric losses of the insulating materials used for submarine telecommunication cables.     

Highly precise experimental device for determining the heat capacity of liquids under pressure

An experimental device for making isobaric heat capacity measurements of liquids under pressure is presented. The device is an adaptation of the Setaram micro-DSC II atmospheric-pressure microcalorimeter, including modifications of vessels and a pressure line allowing the pressure in the measurement system to be set, controlled, and stabilized. The high sensitivity of the apparatus combined with a suitable calibration procedure allows very accurate heat capacity measurements under pressure to be made. The relative uncertainty in the isobaric molar heat capacity measurements provided by the new device is estimated to be 0.08% at atmospheric pressure and 0.2% at higher levels. The device was validated from isobaric molar heat capacity measurements for hexane, nonane, decane, undecane, dodecane, and tridecane, all of which were highly consistent with reported data. It also possesses a high sensitivity as reflected in its response to changes in excess isobaric molar heat capacity with pressure, which were examined in this work for the first time by making heat capacity measurements throughout the composition range of the 1-hexanol+n-hexane system. Finally, preliminary measurements at several pressures near the critical conditions for the nitromethane+2-butanol binary system were made that testify to the usefulness of the proposed device for studying critical phenomena in liquids under pressure.     

New large volume hydrothermal reaction cell for studying chemical processes under supercritical hydrothermal conditions using time-resolved in situ neutron diffraction

The design and testing of a new large volume Inconel pressure cell for the in situ study of supercritical hydrothermal syntheses using time-resolved neutron diffraction is introduced for the first time. The commissioning of this new cell is demonstrated by the measurement of the time-of-flight neutron diffraction pattern for TiO(2) (Anatase) in supercritical D(2)O on the POLARIS diffractometer at the United Kingdom's pulsed spallation neutron source, ISIS, Rutherford Appleton Laboratory. The sample can be studied over a wide range of temperatures (25-450 °C) and pressures (1-355 bar). This novel apparatus will now enable us to study the kinetics and mechanisms of chemical syntheses under extreme environments such as supercritical water, and in particular to study the crystallization of a variety of technologically important inorganic materials.     

Radial gas-permeability measurement in cement-based materials under steady-state flow

An innovative apparatus guided by a proposed theoretical-model was developed for evaluating the radial gas-permeability of cement-based materials under steady-state flow. The testing condition is of higher inlet-gas pressure in an annular concrete cavity to monitor the pressure decrease over time. The gas-tightness for the cavity was effectively enhanced and quantitatively characterized by an ingenious silicone-rubber washer with embedded flexible sensors. The radial gas-permeabilities of the annular concrete with different water-to-cement (w/c) ratios of 0.35–0.55 were measured using various inlet-gas pressures (1.0 bar–30.0 bars) and compared to those obtained by the traditional axial-direction method. The results show that the concrete gas permeability in radial-direction reaches stable permeability zone (SPZ) with inlet-gas pressure exceeding 6.0 bars, which is faster than the SPZ with inlet-gas pressure exceeding 15.0 bars of the axial-direction gas permeability obtained by the traditional method. Under the same inlet-gas pressures of 6.0 bars–10.0 bars, the intrinsic permeability values in the radial and axial directions are near to each other with the standard deviations of 2.83%~9.90% while the apparent permeability values in the radial direction are lower than those in the axial direction by reductions of 3.69%~21.89%. The evolution of apparent gas permeability in radial-direction obeys well the typical model with the low coefficients of variation from 1.01% to 12.55%, indicating that the as-obtained apparatus combined with the proposed theoretical-model can quantitatively and accurately evaluate the radial-direction gas permeability of cement-based materials.     

去除钢轨肥边的新型作业系统的设计

分析了钢轨肥边的产生原因及危害,阐述了用铣削方式去除肥边的可行性及优势,并着重讨论了夹轨系统的特点及设计要点,以及作业车走行驱动机构的布局,为设计精确和高效的钢轨肥边去除作业车提供了一种新的设计思路。     

Thermal and squeezing effects in non-newtonian fluid film lubrication of rollers

Rigid cylindrical rollers, with rolling and squeezing motions, lubricated by a non-newtonian power law fluid are analysed under cavitation boundary conditions. The lubricant consistency is assumed to vary exponentially with pressure and temperature. These pressures and temperatures are found by solving simultaneously the modified Reynolds and energy equations. Various bearing characteristics are presented and discussed. Also presented are the results obtained when the temperature effect on the lubricant consistency is neglected. The effect of temperature on the consistency is to shift the position of the pressure peak slightly towards the centre line of contact. The viscometric exponent n of the power law fluid and the squeezing velocity q are shown to have pronounced effects on the lubrication behaviour of the system under consideration. The consistency variation, especially in the pressure peak region, for dilatant and newtonian fluids, is quite significant.     

Design and simulation of dust extraction for composite drilling

Due to its high strength-to-weight ratio, composite materials have been widely applied in aerospace manufacturing. However, some challenges are facing in fabrication and assembly of the parts with composite materials. One of them is how to collect the dwarf and dust generated from the drilling operation, especially in an open environment when the composite parts are assembled, since a large number of holes need generating to rivet the parts together when the parts with composite materials are assembled in an aircraft structure. The efficiency of dust extraction is crucial to the healthy operating environment and the quality of the assembled component. In this paper, three conceptual designs of automatic dust extraction are proposed and compared, and the best design with the hood fastened on the drilling spindle has been selected and analyzed. Its design parameters have been identified; a systematic procedure has been proposed for the design optimization; the process of the dust extraction has been modeled and simulated using the COSMOSFloWorks. Taguchi method is applied to optimize the design. The process of the dust extraction has been validated through animation.     

基于单片机的多功能静电衰减测试仪

静电衰减时间常数是定量描述材料静电性能的重要物理量，可以通过测量静电电荷衰减时间达到测量静电的目的。在对现有静电测试方法以及各类静电衰减测试仪研究的基础上，基于单片机原理设计出多功能电荷衰减测试仪，它集充电法、电晕喷电法、摩擦法测试功能为一体，弥补了现有静电衰减测试仪功能单一的不足，利用单片机本身的定时计数功能得到精确的静电电荷衰减时间。     

胎压无源监测系统的电能发生装置研究

针对目前汽车行业中常用的直接式轮胎压力监测系统的供电问题,以超磁致伸缩材料作为核心元件,利用其磁致伸缩逆效应,设计一种可产生电能的发电装置。利用该装置为汽车轮胎压力监测系统的检测发射模块供电,可改变纽扣电池的供电方式。研究成果为解决汽车轮胎压力监测系统的供电问题提供一种有效方法,对实现压力监测系统的无源化具有一定的推动作用,为超磁致伸缩材料的应用提供一种新途径。     

自动旋盖组装机气动系统的设计

为了满足吸嘴袋大批量自动化生产需求,提供一种自动旋盖组装机设计方案。介绍了自动旋合组装机的上料机构、自动旋盖装置、检测单元和下料机构的工作原理,重点阐述了机械手和自动旋盖装置气动控制系统的设计内容。新设计的设备投入生产后既能保证旋盖组装质量,又显著提高生产效率。     

Gas loading apparatus for the Paris-Edinburgh press

We describe the design and operation of an apparatus for loading gases into the sample volume of the Paris-Edinburgh press at room temperature and high pressure. The system can be used for studies of samples loaded as pure or mixed gases as well as for loading gases as pressure-transmitting media in neutron-scattering experiments. The apparatus consists of a high-pressure vessel and an anvil holder with a clamp mechanism. The vessel, designed to operate at gas pressures of up to 150 MPa, is used for applying the load onto the anvils located inside the clamp. This initial load is sufficient for sealing the pressurized gas inside the sample containing gasket. The clamp containing the anvils and the sample is then transferred into the Paris-Edinburgh press by which further load can be applied to the sample. The clamp has apertures for scattered neutron beams and remains in the press for the duration of the experiment. The performance of the gas loading system is illustrated with the results of neutron-diffraction experiments on compressed nitrogen.     

一种新型面向制造工艺的测控实验装置的研究

介绍一种新型教学仪器,测控实验装置的设计思路及其组成,包括系统总体流程、系统组成、测量原理和误差分析。为了满足机械制造专业数控车削形位公差测量实验教学的需求,设计并制造了一套新型的测控工艺系统。测控系统包括测量和控制两大部分,实现对被测工件直径、圆度和圆柱度的在线测量,该装置具有结构简单、集成度高的特点,克服了传统教学设备的局限性。     

Large volume high-pressure cell for inelastic neutron scattering

Inelastic neutron scattering measurements typically require two orders of magnitude longer data collection times and larger sample sizes than neutron diffraction studies. Inelastic neutron scattering measurements on pressurised samples are particularly challenging since standard high-pressure apparatus restricts sample volume, attenuates the incident and scattered beams, and contributes background scattering. Here, we present the design of a large volume two-layered piston-cylinder pressure cell with optimised transmission for inelastic neutron scattering experiments. The design and the materials selected for the construction of the cell enable its safe use to a pressure of 1.8 GPa with a sample volume in excess of 400 mm(3). The design of the piston seal eliminates the need for a sample container, thus providing a larger sample volume and reduced absorption. The integrated electrical plug with a manganin pressure gauge offers an accurate measurement of pressure over the whole range of operational temperatures. The performance of the cell is demonstrated by an inelastic neutron scattering study of UGe(2).     

The extended surface forces apparatus. IV. Precision static pressure control

We report on design and performance of an extended surface forces apparatus (eSFA) built into a pressurized system. The aim of this instrument is to provide control over static pressure and temperature to facilitate direct surface force experiments in equilibrium with fluids at different loci of their phase diagram. We built an autoclave that can bear a miniature eSFA. To avoid mechanical or electrical feedtroughs the miniature apparatus uses an external surface coarse approach stage under ambient conditions. The surface separation is thus pre-adjusted to approximately ~3 μm before sliding the apparatus into the autoclave. Inside the autoclave, the surface separation can be further controlled with a magnetic drive at sub-?ngstrom precision over a 14 μm range. The autoclave pressure can then be set and maintained between 20 mbar and 170 bars with few mbar precision. The autoclave is connected to a specially designed pressurization system to precondition the fluids. The temperature can be controlled between -20 and 60 °C with few mK precision. We demonstrate the operation of the instrument in the case of gaseous or liquid carbon dioxide. Thanks to a consequent decoupling of the eSFA mechanical loop from the autoclave structure, the obtained measurement stability and reproducibility, at elevated pressures, is comparable to the one established for the conventional eSFA, operated under ambient conditions.     

Simple sensitive capacitance manometer for corrosive gas laser systems

The design and performance of a capacitance manometer for use in corrosive gas laser environments is presented. This simple and inexpensive isolating device can be quickly fabricated in any machine shop, and permits the utilization of ordinary non-passivated pressure measurement apparatus or gauges in any gas system, irrespective of the corrosiveness.     

松质骨流-固-热多场耦合微流速渗流实验研究及数值分析

在达西定律基础上自主研制了松质骨流固热多场耦合微流速渗透率测量装置,利用该装置对猪股骨结节新鲜松质骨进行了渗透试验,得到了该材料在不同的压力和温度下的渗透率,并且和理论数据进行了对比.建立了松质骨在流-固-热多场耦合下孔隙度和渗透率随温度和压力变化的动态数学模型.分析了实验过程中温度和流体压力等因素对实验结果的影响,讨论了该试验装置的相关应用范围和发展前景.     

一种压力控制式断电保护装置的设计及应用

介绍了一种压力控制式断电保护装置的设计及应用，该装置可用来控制对液压，气压等压力有一定要求的电器装置，当压力在安全值之外时，将自动切断供电电源，对用电器进行保护。该装置结构简单，成本低廉，安装及操作方便，通过一年多对蒸馏水器的控制，该装置表现了优良的性能，工作可靠，控制灵敏。     

High pressure hermetic compression seals for embedding elastomeric membrane microvalves in polymer microfluidic devices

The application of elastomeric membrane microvalves with polymeric microfluidic devices is currently impeded by bonding methods which limit operating pressures. A novel compression sealing approach is presented for embedding elastomeric membranes between polymeric microchannel laminae through the use of sealing bosses. Sealing bosses are used effectively to concentrate clamping forces producing compression seals with higher operating pressures. The technique is capable of integrating elastomeric membrane microvalves within a wider variety of materials. Further, compression seals allow devices to be disassembled allowing for cleaning and analysis. Finite element methods are used to investigate the effects of sealing boss size and location on valve deformation as a function of clamping pressure. Experimental results are in good agreement with the model and show that the device can be configured to withstand operating pressure beyond 689 kPa.