Inherent safer design for chemical process of 1,4-dioldiacetate-2-butene oxidized by ozone

Abstract

Oxidation reaction is the typical thermal runaway reaction, and the reaction of 1, 4-dioldiacetate-2-Butene oxidized by ozone was investigated in this study. Firstly, the thermal hazards of the oxidative exothermic reactions were identified and evaluated combined process risk assessment method. The Qualitative Assessment for Inherently Safer Design (QAISD) was used to identify the risk of the reaction process. Meanwhile, the Reaction Calorimeter (RC1^e) was used to obtain the thermal properties of the oxidation reaction. Then the inherent safer designs (ISD) were proposed according to the risk assessment results to increase the level of safety of chemical industry technique. 1) ISD I: reaction temperature was improved to –5?°C, and ventilation rate was improved to 200?L?h^?1. 2) ISDII: using a tubular reactor as reaction vessel. The results indicated that the severity of the reaction hazard was reduced by 43%, and safety was improved significantly via two ISDs. Moreover, the inherent safety level of the reaction was increased by 63% and 43.4% via ISD Iand II, respectively. The reaction process get closer to inherent safety theories of “minimize,” “substitute,” and “moderate”.     

低温烘焙下城市生活垃圾与烟煤的混燃特性

为了探讨垃圾与煤的混燃特性,选取城市生活垃圾(MSW)和烟煤(BC)为研究对象,通过热重分析法研究烘焙温度、掺混比例、升温速率对样品燃烧特性的影响,并采用Kissinger-Akahira-Sunose(KAS)法计算样品的活化能.结果表明:MSW经220℃,260℃和300℃低温烘焙后,热值都有所提升,随着烘焙温度上...     

Supercritical CO2 oil extraction from Chinese star anise seed and simultaneous compositional analysis using HPLC by fluorescence detection and online atmospheric CI‐MS identification

BACKGROUND: Supercritical CO₂ was utilised to extract Chinese star anise seed oil (CSASO), and a three‐level Box–Behnken factorial design from response surface methodology was applied to optimise the extraction conditions, including pressure, temperature and amount of modifier (ethanol). The compositional analysis of fatty acids in CSASO was performed by HPLC with fluorescence detection using 2‐(11H‐benzo[a]carbazol‐11‐yl)‐ethyl‐4‐methylbenzenesulfonate (BCETS) as labelling reagent. Identification was carried out by online atmospheric chemical ionisation–mass spectrometry. RESULTS: The optimum extraction conditions were as follows: extraction pressure, 27.72 MPa, extraction temperature, 46.22 °C, and amount of modifier, 8.58 vol.%. The experimental result showed that the maximum extraction yield was 25.31 ± 0.22% (w/w) under the conditions proposed. The compositional analysis indicated that CSASO mainly contained C18:2, C18:1, C18:3, C20:4, C16, C18 and C20 fatty acids. CONCLUSION: In this study, a fast, simple and high‐efficiency supercritical technique for extracting oil from Chinese star anise seed was developed. Simultaneous determination of fatty acids in CSASO using BCETS as the labelling reagent with HPLC fluorescence detection and online mass spectroscopy identification has been successfully achieved. Copyright © 2010 Society of Chemical Industry     

硼酸-柠檬酸比色法测银杏枝叶中黄酮苷含量

用硼酸-柠檬酸比色法测定了银杏枝叶不同季节黄酮苷的含量,结果表明:硼酸-柠檬酸比色法测定银杏枝叶中的黄酮苷含量稳定性好,精度高,标准差为0.06,黄酮苷测定回收率为98.3%～101.1%,测定结果不受脂溶性杂质的干扰;银杏枝叶中的黄酮苷含量随季节的变化而变化,8月黄酮苷含量最高。     

基于机器视觉的人体尺寸识别系统

提出了一种基于机器视觉的人体尺寸识别系统的技术思路,系统将机器终端获取的人体图像信息,利用图像处理技术和人体关键尺寸的生理位置特征,实现人体关键尺寸的识别。该系统中需要获取人体正面的手臂水平图像以及人体侧面图像,2张图像必须在同一相对位置下获取,以保证参考点的一致,在参考被测用户的实际身高下,系统通过计算可实时给出被测用户的颈部、胸部、腰部、臀部等的正侧面宽度,同时给出各对应部分的所在位置。这种模式可以给出用户的基本尺寸信息,从而可以为用户实现模拟试衣等仪器提供软件支持。     

茎瘤芥瘤茎质构分析

质构是榨菜重要的品质特征,与榨菜原料（茎瘤芥瘤茎）的质构和加工工艺密切相关。 采用质构分析（TPA）仪对茎瘤芥瘤茎及 榨菜进行质构分析,结果表明,茎瘤芥瘤茎头部与中部的弹性、咀嚼性和粘结性,头部与尾部的硬度和脆度无显著性差异（P＞0.05）, 其他质构指标均有不同程度的显著性差异（P＜0.05）;各个部位质构指标分析数据离散程度小;茎瘤芥瘤茎各个部位的咀嚼性-粘结 性、咀嚼性-弹性相关性较高;茎瘤芥瘤茎质构各个指标的相关性的规律性与取样方式有关,芯部硬度与脆度的相关性较高,而皮层 硬度与脆度的相关性较低。 榨菜的脆度值较茎瘤芥瘤茎减小,而榨菜的硬度值、弹性值、内聚性值、咀嚼性值和粘结性值较茎瘤芥瘤 茎增大。     

Ultrasensitive Determination of Cadmium in Rice by Flow Injection Chemiluminescence Analysis

Based on the enhancing effect of Cd²⁺ on luminol–Co²⁺ chemiluminescence (CL) system, a sensitive method for determining picogram Cd²⁺ in rice by flow injection (FI)–CL was proposed. It was found that the CL intensity increments were proportional to the concentrations of Cd²⁺, giving a calibration graph linear over the Cd²⁺ concentrations ranging from 7.0 to 5,000.0 pmol L^?1, with a detection limit of 2.0 pmol L^?1 (3σ) and relative standard deviations (RSDs) of 3.2, 2.8, and 2.5 % for 30.0, 300.0, and 1,000.0 pmol L^?1 Cd²⁺ (n?=?5), respectively. At a flow rate of 2.0 mL min^?1, a complete determination of Cd²⁺ including sampling and washing could be accomplished within 36 s, giving a sample throughput of 100 h^?1. The contents of Cd²⁺ in rice were found to be 0.07–0.10 mg kg^?1. The proposed method was also applied to the determination of Cd²⁺ in spiked human serum samples with recoveries from 95.9 to 106.3 % and RSDs less than 4.0 %.     

Phase behaviors of polymer solution confined between two concentric cylinders

A theoretical study on the phase behaviors of a polymer solution confined between two coaxial cylindrical walls is presented. For the case of a neutral inner cylinder, the spinodal point derived by the Gaussian fluctuation theory is confinement-independent because of the existence of a free dimension in the system. The kinetic analysis indicates that the fluctuation modes always have a component of a plane wave along the axial direction, which can lead to the formation of a periodic-like concentration pattern. On the other hand, the equilibrium structure of the system is obtained by the self-consistent mean-field theory (SCMFT) and the interplay between the “wetting” phenomenon and the phase separation is observed by modifying the property of the inner cylindrical wall. In particular, our results can be regarded as a hint to interpret the mechanism of the formation of the shish-kebab structure observed in the field of polymer crystallization.     

转谷氨酰胺酶催化花生浓缩蛋白对凝胶硬度和弹性的影响

以花生浓缩蛋白为原料,采用响应面分析方法研究转谷氨酰胺酶用量、底物质量浓度和作用pH对花生浓缩蛋白凝胶硬度和弹性的影响,并对作用条件进行优化.结果表明:底物质量浓度和作用pH对凝胶硬度、弹性均具有极显著影响;酶用量对硬度有显著影响,且它与底物质量浓度之间的交互作用对弹性有显著性影响.随底物质量浓度和pH的增加,蛋白的凝胶硬度逐渐增大,随着酶用量和底物质量浓度增大凝胶弹性增加.凝胶硬度和弹性的优化条件为:酶用量11.32～13.08 U/g,底物质量浓度0.152 3～0.153 3 g/mL,作用pH 7.03～7.46.