Predicting and controlling flammability of multiple fuel and multiple inert mixtures

Le Chatelier's Rule is in wide use for predicting the flammability of mixtures with multiple fuels present. The rule does not conveniently handle multiple inerts or elevated temperatures and pressures. This paper describes an alternate method, developed at Air Products, called FLAMCHEK^TM, which conveniently handles these variables. This method for predicting flammability is based upon the commonality of the adiabatic flame temperature of a wide variety of fuels at their upper and lower flammable limits. The method, if PC based, can be extended to automatically control the addition of inerts, fuels, or oxidizers in order to avoid flammable conditions. The concept may be extended to more involved applications, such as within an oil well with fuel gas mixtures containing oxygen. In this case, the location from which a gas sample is obtained for analysis (wellhead) may have a different fuel analysis and flammability condition than the location where an explosion is likely to initiate (bottom of well). Hence a correction of the fuels analysis is required.     

An index for sequential project selection

Abstract.In the chemical and pharmaceutical industries, a series of screening experiments is often run on a class of compounds or mixtures of several classes of compounds. The data obtained from the screens can be utilized to assess the project progress and/or the best routes to take for further research. This problem is similar in many ways to that of project selection. In this paper a sequential method of calibrating individual projects is developed which is relevant both to project selection and assessing how best to deploy further effort in projects of the type described. This paper was delivered at the European Conference of Management of Research and Development and Technological Forecasting. Paris. October, 1970.     

用神经网络对开式冷挤压极限变形程度的预测

给出了基于 BP网络的极限变形程度预测的分析方法 ,得到了开式冷挤压εmax神经网络计算结果 ,与实验结果比较 ,其精度较高 ,证明了神经网络模型在开式冷挤压工艺中应用的可行性。     

Structured packings for use in oxygen service: Flammability considerations

Metallic structured packings have found increasing use in the cryogenic distillation of air. An experimental program was performed to test the flammability of selected metal packings under simulated high oxygen concentration operating conditions. Aluminum flammability in gaseous oxygen has been shown to be very dependent upon argon dilution, and in the presence of liquid oxygen, strong energy releases have been observed. Brass packing exhibited an unexpectedly high relative flammability whereas copper has been found to be non-flammable in all tested oxygen purities. These findings suggest the use of copper structured packing in higher purity GOX/LOX regions of an air separation distillation column and aluminum structured packing in the remainder of the column.     

Case history of a deflagration involving an organic solvent/oxygen system below its flash point

A deflagration occurred in a pilot scale vessel containing an oxygen atmosphere and an organic solvent well below the flash point. This was unexpected since the experiment had been carried out on a smaller scale over 50 times. Further investigation of the incident showed that the loading of the vessel and agitation system produced a flammable mist which was capable of explosion at temperatures below the flash point. Simulation studies of the mist conditions in a controlled flammability system were also conducted. Ignition sources were also investigated and at least two were shown to be feasible.     

Vent heights for emergency releases of heavy gases

A method to estimate vent heights for emergency releases of heavy gases to prevent flammability at exposed locations has been developed.     

Combustion hazards of silane and its chlorides

This paper addresses the unusual combustion hazards of silane and its chlorides, comprising the homologous chlorosilane series SiH_nCl_4-n. The literature on silane is briefly reviewed and new experimental data presented showing the effects of sudden releases into free air. New data are presented for ignition sensitivities and deflagration rates of chlorosilane mixtures with air. Specific hazardous reactions of this group of materials are described and contrasted with those of the analogous alkanes. Mechanisms for flame acceleration and transition to detonation are discussed.     

Batch runaway reaction relief: Re-evaluation of “Credible” scenario

Many chemical reactions in the fine chemical and related industries are performed in a semi-batch manner under isothermal conditions. Relief system design evaluation for runaway reactions, using DIERS methodology for example, is frequently studied adiabatically using data derived from batch mode testing. In many cases, however, evaluation of the process isothermally under the realistic semi-batch mode can be extremely useful, often helping to greatly reduce the vent size as a result of a better understanding of the process. In some cases, it is even possible to eliminate runaway reaction as a viable case for relief sizing. Such evaluations of venting are fully consistent with DIERS methodology. This paper presents the arguments for sizing vents for scenarios other than the very worst case, by objective evaluation of trips and interlocks, so that the level of risk is reduced to an acceptable level without the need for extremely large vents.     

三次采油用聚合物黏弹性评价新方法

黏弹性是影响聚合物驱油效率的重要因素。在聚合物常规理化性能检测标准中,没有关于聚合物黏弹性的检测指标。采用CaBER毛细管拉伸断裂流变仪测试聚合物溶液流体丝直径随时间变化曲线,用Exponential模型对曲线进行拟合,拟合的松弛时间可以作为评价聚合物溶液黏弹性大小的技术指标。对水解聚丙烯酰胺、疏水缔合聚合物和高分子表面活性剂的实验研究证明,该评价方法具有样品用量少、操作简便、检测数据重复性高的优点。此外,对采用该方法所适用的聚合物溶液体系及实验条件进行了研究。结果表明:采用聚合物溶液浓度为500mg/L比较合适,在测试前需要对其进行过滤;实验温度应控制在45℃。     

主成分分析方法及其在各仪器分析中的应用

主成分分析是在尽可能保留原有信息的基础上将高维空间中的样本映射到较低维的主成分空间中,使数据矩阵简化,降低维数,寻找少数几个由原始变量线性组合的主成分,以揭示数据结构特征,提取化学信息。随着计算机技术及其应用的发展,作为化学计量学基础的主成分分析方法在仪器分析中的应用越来越广泛,综述了自20世纪90年代至今主成分分析方法在各仪器分析中的应用。     

User-oriented design for the optimal combination on product design

This paper presents a new approach of user-oriented design for transforming users’ perception into product elements design. An experimental study on mobile phones is conducted to examine how product form and product color affect product image individually and as a whole. The concept of Kansei Engineering is used to extract the experimental samples as a data base for Quantitative Theory Type I and neural networks (NNs). The result of numerical analysis suggests that mobile phone makers need to provide various product colors to attract users, in addition to product forms. This paper demonstrates the advantage of using NNs for determining the optimal combination of product form and product color, particularly if the product into design elements. Based on the analysis of NNs, we can use 72 representative product colors of each mobile phone to develop a product color data base consisting of 16777216 (=256×256×256, True-Color model) colors with the associated product image. The design data base provides useful insights to save any amount of money and time for the new product development. The product designers can input a product image to work out an adequate color on a mobile phone. Furthermore, the design data base can be used, in conjunction with computer-aided design system or virtual reality technology, to build a 3D model for facilitating the design process of mobile phones. Although, the mobile phones are chosen as the object of the experimental study, this approach can be applied to other products with various design elements.     

关于配合物稳定常数的测定

介绍了利用光学密度法测定配合物的组成及其稳定常数的原理,并以Cu2+-磺基水扬酸-水体系为例,详细介绍了使用光学密度法测定配合物组成及其稳定常数的实验过程以及数据处理过程。     

超声波在化学工业中的应用

介绍了近年来超声波在化学工业中的应用与进展,以及超声波的特征和超声波促进化学反应的基本原理,较为全面地总结了超声波在有机合成、聚合反应、结晶过程、萃取分离、超细粉体制备等方面的国内外应用情况,总结了超声外场付诸于化学工业所遇到的主要困难是对于超声化学理论知识的研究还不够成熟以及缺乏适用于工业化生产的超声化学反应器,提出解决问题的关键是需要大量学者对超声化学的反应机理方面进行更加深入的研究与探索。指出超声外场是一种新型的催化体系,超声化学具有广阔的应用前景。     

符号学在报刊亭设计中的应用

在对报刊亭初始功能符号系统分析的基础上,探索符号学在报刊亭设计中的应用方法。提出了将报刊亭作为符号系统进行设计的思想,分别给出了符号"分节"理论,符号"组合/聚类"理论及符号语法、语义规则在报刊亭设计中的应用方法,总结出了基于符号学理论的报刊亭设计新方法的优势。该方法从局部到整体,以全新的视角研究了报刊亭设计的方法。     

Forecasting derived product demand in commercial construction

This article presents a practical scheme for forecasting derived demand for an industrial product used in the nonresidential construction industry. The method proposed includes a basic product requirement model to be used in conjunction with lagged construction award data. Twelve-month moving averages are used to smooth the basic construction contract award data which is analyzed by construction type and by geographic region.The methodology described enables accurate product sales potential estimation, and when compared with smoothed historical sales data, provides a means of evaluating market penetration. Although the method presented is concerned primarily with forecasting in the relatively short term, the scheme may be extended to a medium term corresponding roughly to the construction cycle. The article deals with application to a specific industry segment. However, the forecasting and evaluation procedure is adaptable to other industrial products.     

Emergency pressure relief discharge control by passive quenching—update

A recent runaway reaction emergency relief system design includes a passive quench tank to collect and contain the two-phase emergency relief discharge. This avoids the release of a large vapor cloud to the atmosphere and the attendant flammability and toxicity hazards. The feasibility of quenching is demonstrated with small scale experiments. A pressure relief simulation model is shown to accurately reproduce the observed temperature and pressure profiles in both the reactor and quench tank during relief. The model is then applied to the design of a full scale system. Quench system design considerations are discussed.     

章动齿轮传动中直齿内锥齿轮加工及在线检测研究

针对内锥齿轮副加工困难,提出1种内锥齿轮副中内锥齿轮的加工方法。同时,基于锥齿轮啮合模型进行误差分析,利用Matlab软件建模并求出在线检测所需参数,通过对机床参数的调整,提高了内锥齿轮齿形加工精度。通过生产实践表明,该加工和检测方法是行之有效的。     

Real Estate Investment Funds: Performance and Portfolio Considerations

This paper presents the results of a study dealing with a number of issues regarding real estate investment. Utilizing a data set consisting of returns from two of the oldest, continuously operating commingled real estate funds (CREFs), questions relative to investment performance, inflation hedging attributes and diversification benefits are addressed. The methodology used in exploring these issues are variants of the traditional capital asset pricing model (CAPM), extended to consider uncertain inflation (CAPMUI) and an arbitrage pricing model in which real estate performance is judged relative to a more inclusive market index representing larger numbers of substitute investments. Finally, issues relative to portfolio performance are considered by constructing portfolios containing all possible combinations of real estate, stocks and bonds to assess the potential for diversification benefits and portfolio performance.     

基于数据融合的分布式入侵检测系统研究

针对分布式入侵检测在当今网络安全中发挥着越来越重要的角色,将数据融合技术引入到入侵检测系统中,提出了基于数据融合的分布式入侵检测系统设计方案,描述了分布式检测和决策融合的结构设计,讨论了数据融合决策问题的数学模型,运用理论推理论证了融合决策处理的可靠性。分析比对实验表明,该系统降低了入侵检测系统的虚警率,提高了检测率。     

Space-Varying Regression Coefficients: A Semi-parametric Approach Applied to Real Estate Markets

This paper presents a method for estimating home values by non-parametrically incorporating the physical location of the properties. Specifically, I allow the parameters of the observed covariates to vary in space. This approach mitigates one of the biggest deficiencies inherent in hedonic pricing models–omitted variables. I demonstrate the advantages of the proposed method using real estate transaction data from Los Angeles County. The estimation finds a substantial spatial variation of the marginal values of the hedonic characteristics and provides an insight into the segmentation of the market. The proposed method is an extension of semi-parametric multi-dimensional k-nearest-neighbor smoothing. It alleviates a fundamental problem known as the curse of dimensionality by incorporating parametric components into a non-parametric estimation.