Isofrax(R)和Insulfax(R)生物可溶性纤维的研究

综述生物可溶性纤维的研究进展,介绍矿物纤维对人体健康的影响以及国际上对矿物纤维进行健康分类的主要规范.分析了Unifrax公司研制Insulfrax(R)和Isofrax(R)两种可溶性耐火纤维的基本性能和应用情况.Isofrax(R)和Insulfrax(R)均是绿色环保型隔热材料,在欧美已成功地应用于各种热处理工业中.     

PROMATRIX(R)系统软件

PROMATRIX(R) DESIGNER 安装在Windows 95/98/2000/XP/NTTM等系统平台上,可以方便地完成PROMATRIX(R)的配置和存盘.     

ACTICARBON(R) 活性炭

ARKEMA(阿科玛)集团下CECA公司ACTICARBON 活性炭用海边的松木生产,此松木来自Landes(法国南部)的单一松树林,拥有非常好的纯度,优异的均一度,及非常高的吸附能力,性能稳定,在医药和催化剂载体等行业效果尤为突出.     

Development of a lyophilized formulation for (R,R)-formoterol (L)-tartrate

(R,R)-formoterol is a beta-agonist for inhalation. Aqueous instability suggested the need for a reconstitutable lyophilized dosage form. The objective of these studies was to devise a stable, rapid-dissolving, therapeutically compatible dosage form. The effects of diluents and residual moisture on the stability of thermally stressed formoterol formulations were investigated. Drug and various excipients (acetate, lactose, and mannitol) were lyophilized and placed in humidity chambers (0 to 90% relative humidity) at 25 to 50 degrees C. Stability was characterized by time-dependent changes using HPLC, pH, and XRD. Residual moisture were determined by Karl Fisher methods. Regression models were developed to quantify the effects of formulation and environmental variation on drug stability. Solid-state instability was observed as a function of high residual moisture and diluent type. Although the residual moisture in mannitol formulations were typically below 1%, the degradation rate (50 degrees C) varied from 2 to 10 mcg/day, which was 1.3- to 20-fold high than observed for lactose formulations under the same relative humidity conditions. At high relative humidity, the presence of acetate significantly increased the degradation rate (p < 0.04). The critical residual moisture content for lactose formulations was 3%. The amount of lactose was optimized by evaluating the degradation over the temperature range 25 to 50 degrees C. Mannitol and acetate were shown to be unsuitable excipients, and an optimal lactose amount was 50 mg for vials containing 50 mcg of drug.     

Development of a Lyophilized Formulation for (R,R)-Formoterol (L)-Tartrate

(R,R)-formoterol is a β-agonist for inhalation. Aqueous instability suggested the need for a reconstitutable lyophilized dosage form. The objective of these studies was to devise a stable, rapid-dissolving, therapeutically compatible dosage form. The effects of diluents and residual moisture on the stability of thermally stressed formoterol formulations were investigated. Drug and various excipients (acetate, lactose, and mannitol) were lyophilized and placed in humidity chambers (0 to 90% relative humidity) at 25 to 50°C. Stability was characterized by time-dependent changes using HPLC, pH, and XRD. Residual moistures were determined by Karl Fisher methods. Regression models were developed to quantify the effects of formulation and environmental variation on drug stability. Solid-state instability was observed as a function of high residual moisture and diluent type. Although the residual moistures in mannitol formulations were typically below 1%, the degradation rate (50°C) varied from 2 to 10 mcg/day, which was 1.3- to 20-fold high than observed for lactose formulations under the same relative humidity conditions. At high relative humidity, the presence of acetate significantly increased the degradation rate (p < 0.04). The critical residual moisture content for lactose formulations was 3%. The amount of lactose was optimized by evaluating the degradation over the temperature range 25 to 50°C. Mannitol and acetate were shown to be unsuitable excipients, and an optimal lactose amount was 50 mg for vials containing 50 mcg of drug.     

三元混合制冷剂R32+R161+R1234yf气液相平衡实验研究

本文研究了含R1234yf的三元混合制冷剂的气液相平衡性质和模型,利用基于液相单相循环法搭建的气液相平衡实验装置,对温度范围为283.15～323.15 K的三元混合制冷工质R32+R161+R1234yf进行了实验研究,共得到45组实验数据。同时采用Peng-Robinson-Stryjek-Vera(PRSV)状态方程结合Wong-Sandler(WS)混合法则和Non-Random Two-Liquid(NRTL)活度系数模型,在前期工作得到的二元混合工质的模型参数的基础上,对三元混合工质气液相平衡性质进行推算。最后将模型推算结果与实验数据进行对比,结果表明系统压力平均绝对偏差AAD_p为0.34%,系统组分R32和R161的气相摩尔分数平均绝对偏差AAD_y_1和AAD_y_2分别为0.002和0.001。     

The vapor pressure of 1,1,1,2-tetrafluoroethane (R134a) and chlorodifluoromethane (R22)

We measured the vapor pressure of chlorodifluoromethane (commonly known as R22) at temperatures between 217.1 and 248.5 K and of 1,1,1,2-tetrafluoroethane (commonly known as R134a) in the temperature range 214.4 to 264.7 K using a comparative ebulliometer. For 1,1,1,2-tetrafluoroethane at pressures between 220.8 and 1017.7kPa (corresponding to temperatures in the range 265.6 to 313.2K), additional measurements were made with a Burnett apparatus. We have combined our results for 1,1,1,2-tetrafluoroethane with those already published from this laboratory at higher pressures to obtain a smoothing equation for the vapor pressure from 215 K to the critical temperature. For chlorodifluoromethane our results have been combined with certain published results to provide an equation for the vapor pressure at temperatures from 217 K to the critical temperature.     

ISOFLUX(R)膜——微滤膜极品

介绍一种新型的恒通量的微滤膜－ISOFLUX^R膜，该种膜的膜通量衰减比通常的微滤膜要小得多，对ISOFLUX^R膜的原理和数学模型进行了推导，并给出了对牛奶进行冷杀菌过滤的结果。     

Liquid thermal conductivity of binary mixtures of difluoromethane (R32) and pentafluoroethane (R125)

The thermal conductivities of refrigerant mixtures of difluoromethane (R32) and pentafluoroethane (R125) in the liquid phase are presented. The thermal conductivities were measured with the transient hot-wire method with one bare platinum wire. The experiments were conducted in the temperature range of 233–323 K and in the pressure range of 2–20 MPa. An empirical equation to describe the thermal conductivity of a near-azeotropic mixture, R32+R125, is provided based on the measured 168 thermal conductivity data as a function of temperature and pressure. The dependence of thermal conductivity on the composition at different temperatures and pressures is also presented. The uncertainty of our measurements is estimated to be ±2%. Paper dedicated to Professor Edward A. Mason.     

General run-to-run (R2R) control framework using self-tuning control for multiple-input multiple-output (MIMO) processes

During recent years, run-to-run (R2R) control techniques have been developed and used to control various semiconductor manufacturing processes. The R2R control methodology combines response surface modelling, engineering process control, and statistical process control. The main objective of such control is to manipulate the recipe to maintain the process output of each run as close to the nominal target as possible. The primary focus of this research is on the multiple-input multiple-output self-tuning control of R2R processes. A general control scheme is presented that can compensate for a variety of noise disturbances frequently encountered in semiconductor manufacturing. The controller can also compensate for various system dynamics, including autocorrelated responses, deterministic drifts, and varying process gains and offsets. Self-tuning controllers are developed to provide on-line parameter estimation and control. A recursive least squares algorithm is normally used to provide on-line parameter estimation to the controller. This type of control strategy used in the proposed self-tuning controller applies the principle of minimizing total cost (in the form of an expected off-target and controllable factors adjustment) to obtain a recipe for the next run. It is shown through the simulation study that even if the control model is non-linear, the self-tuning controller offers satisfactory control performance for R2R applications as compared with those of the control actions provided by the optimizing adaptive quality controller module. At last, a relevant application to chemical mechanical planarization in semiconductor manufacturing, a critical fabrication step involving two quality characteristics (removal rate and within-wafer non-uniformity), is used to illustrate the proposed controller. In this case study, a multivariate statistical process control technique via the Hotelling T?² statistic is also used as a dead-band for further investigation.     

Equations of state for the thermodynamic properties of R32 (difluoromethane) and R125 (pentafluoroethane)

Thermodynamic properties of difluoromethane (R32) and pentafluoroethane (R125) are expressed in terms of 32-term modified Benedict-Webb-Rubin (MBWR) equations of state. For each refrigerant, coefficients are reported for the MBWR equation and for ancillary equations used to fit the ideal-gas heat capacity and the coexisting densities and pressure along the saturation boundary. The MBWR coefficients were determined with a multiproperty fit that used the following types of experimental data: PVT: isochoric, isobaric, and saturated-liquid heal capacities; second virial coefficients; and properties at coexistence. The respective equations of stale accurately represent experimental data from 160 to 393 K and pressures to 35 MPa for R32 and from 174 to 448 K and pressures to 68 MPa for R125 with the exception of the critical regions. Both equations give reasonable results upon extrapolation to 500 K and 60 MPa. Comparisons between predicted and experimental values are presented.Paper presented at the Twelfth Symposium on Thermophysical Properties, June 19–24, 1994, Boulder, Colorado. U.S.A.     

Experimental study of an R1234ze(E)/R134a mixture (R450A) as R134a replacement

This work presents an experimental analysis of a non-flammable R1234ze(E)/R134a mixture (R450A) as R134a drop-in replacement. While R134a has a high GWP value (1430), the R450A GWP is only 547. The experimental tests are carried out in a vapour compression plant equipped with a variable-speed compressor. The replacement suitability has been studied combining different operating conditions: evaporation temperature, condensation temperature and the use of an internal heat exchanger (IHX). The drop-in cooling capacity of R450A compared with R134a is 6% lower as average. R450A COP is even higher to those resulting with R134a (approximately 1%). The discharge temperature of R450A is lower than that of R134a, 2K as average. The IHX has a similar positive influence on the energy performance of both fluids. In conclusion, R450A can be considered as a good candidate to replace R134a.     

Liquid Thermal Conductivity of Binary Mixtures of Pentafluoroethane (R125) and 1,1,1,2-Tetrafluoroethane (R134a)

Thermal conductivities of zeotropic mixtures of R125 (CF₃CHF₂) and R134a (CF₃CH₂F) in the liquid phase are reported. Thermal conductivities have been measured by a transient hot-wire method with one bare platinum wire. Measurements have been carried out in the temperature range of 233 to 323 K and in the pressure range of 2 to 20 MPa. The dependence of thermal conductivity on temperature, pressure, and composition of the binary mixture is presented. Measured thermal conductivity data are correlated as a function of temperature, pressure, and overall composition of the mixture. The uncertainty of our measurements was estimated to be better than 2%.     

Isochoric Specific Heat Capacity of Difluoromethane (R32) and a Mixture of 51.11 mass% Difluoromethane (R32) + 48.89 mass% Pentafluoroethane (R125)

The isochoric heat capacity (c _v ) of difluoromethane (R32) and a mixture of 51.11 mass% R32 + 48.89 mass% pentafluoroethane (R125) was measured at temperatures from 268 K to 328 K and at pressures up to 30 MPa. The reported density measurements are in the single-phase region and cover a range of ρ > 800 kg · m⁻³. The measured data are compared with results measured by other researchers. Also, the measured data are examined with available equations of state. As a result, it is found that the measured c _v ’s agree well with those of other researchers in the measurement range of the present study.     

Development of Run-To-Run (R2R) controller for the multiple-input multiple-output (MIMO) system using fuzzy control theories

Run-to-Run (R2R) control has been extensively applied in semiconductor manufacturing. In particular, del Castillo, E. and Rajagopal, R., A multivariate double EWMA process adjustment scheme for drifting processes. IIE Trans., 2002, 34, 1055–1068, investigated double multivariate exponentially weighted moving average (MEWMA) controller for the multiple-input multiple-output (MIMO) system in an attempt to adjust and maintain the linear dynamic process outputs on target. Multivariate fuzzy control, inherently different from conventional MEWMA-based control, is another promising alternative that consists of fuzzy logic and set concept. Providing the fuzzy control can structure an appropriate membership function for the R2R MIMO system, thus it can be shown a practically useful control tool in comparison to MEWMA control. In this paper, fuzzy logic is utilized to design the multivariate fuzzy controller for the type of R2R applications based primarily on the min-max-gravity method advocated by Gupta, M.M., Kiszka, J.B. and Trojan, G.M., Multivariable structure of fuzzy control systems. IEEE Trans. Sys., Man Cybern., 1986, 16, 638–656. Under a variety of disturbance models, the proposed multivariate fuzzy controller can produce quite competitive control performance when compared to MEWMA control.     

Low temperature specific heats of H(NbIrO) and R(NbPtO)

The specific heats of the hexagonal structures H(NbIrO) and R(NbPtO) have been measured from1.2 to15 K. The R-phase compound is found to be superconducting withT _c =3.8 K. The reduction inT _c from10.1 to3.8 K between the two phases is qualitatively accounted for by corresponding reductions in the density of states and Debye temperature using the BCS theory.This work was performed under the auspices of the Department of Energy.     

Surface tension of low GWP refrigerants R1243zf,R1234ze(Z), and R1233zd(E)

The surface tension of R1243zf, R1234ze(Z), and R1233zd(E) were measured at temperatures from 270 K to 360 K by an experimental apparatus based on the differential capillary rise method. The deviation between the measured surface tension of R134a and R245fa and the calculated surface tension with REFPROP 9.1 (Lemmon et al., 2013) was ±0.13 mN m⁻¹, which is less than the estimated propagated uncertainty in surface tension of ±0.2 mN m⁻¹. Eleven points, thirteen points, and ten points of surface tension data were provided for R1243zf, R1234ze(Z), and R1233zd(E), respectively, in this paper. The measured data and the estimated surface tension using the methods of Miller, 1963, Miqueu et al., 2000, and Di Nicola et al. (2011) agree within the standard deviation of ±0.43 mN m⁻¹. The empirical correlations that represent the measured data within ±0.14 mN m⁻¹ were proposed for each refrigerant.     

Liquid Thermal Conductivity of Ternary Mixtures of Difluoromethane (R32), Pentafluoroethane (R125), and 1,1,1,2-Tetrafluoroethane (R134a)1

The thermal conductivities of ternary refrigerant mixtures of difluoromethane (R32), pentafluoroethane (R125), and 1,1,1,2-tetrafluoroethane (R134a) in the liquid phase have been measured by the transient hot-wire method with one bare platinum wire. The experiments were performed in the temperature range of 233 to 323 K and in the pressure range of 2 to 20 MPa at various compositions. The measured data are correlated as a function of temperature, pressure, and composition. From the correlation, we can calculate the thermal conductivity of pure refrigerants and their binary or ternary refrigerant mixtures. The uncertainty of the measurements is estimated to be ±2%.