复配化妆品防腐剂的增效作用

介绍了化妆品防腐剂发展的新趋势,并以JM-百霉杀液体复合防腐防霉剂为例,通过采用几种常用的防腐剂效力的评价方法进行比较测试,说明复配防腐剂的协同增效作用。     

染发化妆品配方设计

详细地论述了染发化妆品配方设计原则和存在问题，比较全面地提供了染发化妆品的各种动态和信息，为染发化妆品新产品的研究和开发了有益的参考。     

祛斑化妆品的配方设计和应用前景

介绍了祛斑化妆品的市场商机和广阔的应用前景。论述了祛斑化妆品的配方设计原理以及中草药在祛斑化妆品中的应用。系统介绍了祛斑化妆品的美容技术工程。     

丝状菌污泥膨胀简化机理模型

针对引发丝状菌污泥膨胀的因素较多且其机理模型难以表达的问题,从丝状菌生长动力学角度提出了一种污泥体积指数（SVI）简化机理模型。首先,通过研究丝状菌污泥膨胀的形成过程,分析引发丝状菌污泥膨胀的影响因素,获得了影响因素与SVI之间的关系;其次,确定影响SVI的主要因素,设计出SVI的简化机理模型,并利用数据分析和统计方法校正了模型中的参数;最后,将该简化模型应用于实际污水处理厂,实验结果显示该模型能够较好地反映丝状菌污泥膨胀发生过程,获得较高的SVI预测精度。     

The formulation of optimal mixtures with generalized disjunctive programming: A solvent design case study

Systematic approaches for the design of mixtures, based on a computer‐aided mixture/blend design (CAM^bD) framework, have the potential to deliver better products and processes. In most existing methodologies the number of mixture ingredients is fixed (usually a binary mixture) and the identity of at least one compound is chosen from a given set of candidate molecules. A novel CAM^bD methodology is presented for formulating the general mixture design problem where the number, identity and composition of mixture constituents are optimized simultaneously. To this end, generalized disjunctive programming is integrated into the CAM^bD framework to formulate the discrete choices. This generic methodology is applied to a case study to find an optimal solvent mixture that maximizes the solubility of ibuprofen. The best performance in this case study is obtained with a solvent mixture, showing the benefit of using mixtures instead of pure solvents to attain enhanced behavior. © 2016 The Authors AIChE Journal published by Wiley Periodicals, Inc. on behalf of American Institute of Chemical Engineers AIChE J, 62: 1616–1633, 2016     

A mechanistic growth model of a methylotroph

Based on the biochemical knowledge of the RMP-cycle methylotrophs and the experimental results of batch and continuous culture growth of a methylotroph, L3, a simple mechanistic growth model of L3 was developed. The growth model consists of a basic structure and a regulatory structure. The basic-model structure was developed by incorporating formaldehyde as a state variable and including a lpump-and-leak' mechanism of formaldehyde transport. The regulatory-model structure was built by acknowledging growth inhibition due to formaldehyde and formaldehyde inhibition of methanol oxidation. The resulting model describes adequately the batch as well as the stable and unstable steady-state continuous culture behavior of L3 on mixtures of methanol and formaldehyde.     

Predicting the effect of soil-water-air dynamics on ammonia volatilization from applied urea with a mechanistic model

To assess the influence of varying soil water and soil air contents on ammonia volatilization from surface applied urea, a mechanistic model is used to simulate the system. The results are discussed in terms of the effects of soil-water-air dynamics on the movement of urea, ammoniacal-nitrogen and soil base, and on the rate of urea hydrolysis, and their influence on ammonia volatilization. Changing the soil moisture between 90% and 125% of field capacity did not have a marked influence on ammonia volatilization. The predicted losses were at their minimum with a moisture content slightly above field capacity, and increased sharply as the soil moisture fell below 90% of the field capacity. Ammonia volatilization losses measured by experiment at differentf values agreed very well with those predicted by the model. The relative contribution of the liquid pathway over the gaseous pathway of movement of NH₃ through soil increased with increase inf, and, at a givenf, decreased with increase in the pH.     

我国化妆品行业发展现状、瓶颈及趋势

对中国整个化妆品市场现状和特征进行了阐述,对2011年的进出口数据进行了深入分析。同时,指出了中国化妆品市场发展过程中遇到的问题、发展瓶颈以及今后几年的发展措施和战略。最后,对今后化妆品行业的发展趋势进行了总结。     

Optimal design and operation of a steel plant integrated with a polygeneration system

A process integration approach has been applied to integrate a traditional steelmaking plant with a polygeneration system to increase energy efficiency and suppress carbon dioxide emissions from the system. Using short‐cut models and empirical equations for different units and available technologies for gas separation, methane gasification, and methanol synthesis, a mixed integer nonlinear model is applied to find the optimal design of the polygeneration plant and operational conditions of the system. Due to the complexity of the blast furnace (BF) operation, a surrogate model technique is chosen based on an existing BF model. The results show that from an economic perspective, the pressure swing adsorption process with gas‐phase methanol unit is preferred. The results demonstrate that integration of conventional steelmaking with a polygeneration system could decrease the specific emissions by more than 20 percent. © 2013 American Institute of Chemical Engineers AIChE J, 59: 3659–3670, 2013     

Water detection framework for industrial electric arc furnaces: Boundary modelling and formulation

This paper describes the development of a boundary model for the off-gas water vapour in an industrial steelmaking electric arc furnace (EAF). The solution addresses the mechanistic components of a complete EAF water detection framework. The boundary model has been implemented on an industrial alternating current (AC) EAF. The model specifies upper and lower limits in real-time of the expected EAF off-gas water vapour leaving the furnace, and it provides a valuable on-line monitoring tool to the operator on what boundary to expect for the off-gas water vapour in different circumstances. An essential data required for the framework is the EAF off-gas composition. So, in this work, an off-gas analyzer with a human machine interface (HMI) and a supervisory control and data acquisition (SCADA) system was installed in the first step. Then, in order to evaluate the developed water leak detection framework and verify the obtained results, industrial trials were designed in which a certain amount of water was intentionally added into the furnace by increasing the electrode spray water flow rate. Moreover, we have shown how the presented framework can be used to appropriately adjust the alarm setting values in control/emergency shutdown systems of industrial EAF to enhance the safety and availability of the plant.     

4D皮肤模型的构建及其在化妆品原料活性物功效检测中的应用研究

使用Mimedisc作为支架,接种正常人真皮成纤维细胞,经过3周培养形成类似真皮结构,然后在其上接种正常人表皮角质细胞,依次经过浸没培养阶段和气-液相培养阶段,最终在体外形成3D皮肤结构模型。通过Masson染色及一系列免疫组化荧光靶标染色显示此3D皮肤模型有近似真实皮肤的结构及关键蛋白表达。以此模型为工具研究了活性物喜马拉雅雪松精粹对皮肤真表皮连接处(DEJ)的作用。结果显示喜马拉雅雪松精粹可以明显提高表皮的厚度,增加皮肤抵抗外界环境的屏障能力,并且可以显著促进真表皮连接处重要蛋白层粘连蛋白6(Lamivery similar structure of normal human skin (NHS). The results of Masson staining, i     

Fast pyrolysis of glucose‐based carbohydrates with added NaCl part 2: Validation and evaluation of the mechanistic model

A mechanistic model considering the significant catalytic effects of Na⁺ on fast pyrolysis of glucose‐based carbohydrates was developed in Part 1 of this study. A computational framework based on continuous distribution kinetics and mass action kinetics was constructed to solve the mechanistic model. Agreement between model yields of various pyrolysis products with experimental data from fast pyrolysis of glucose‐based carbohydrates dosed with NaCl ranging from 0–0.34 mmol/g at 500 °C validated the model and demonstrated the robustness and extendibility of the mechanistic model. The model was able to capture the yields of major and minor products as well as their trends across NaCl concentrations. Modeling results showed that Na⁺ accelerated the rate of decomposition and reduced the time for complete thermoconversion of carbohydrates. The sharp reduction in the yield of levoglucosan (LVG) from fast pyrolysis of cellulose in the presence of NaCl was mainly caused by reduced decomposition of cellulose chains via end‐chain initiation and depropagation due to Na⁺ favoring competing dehydration reactions. Analysis of the contributions of reaction pathways showed that the decomposition of LVG made a minor contribution to its yield reduction and contributed less than 0.5% to the final yield of glycolaldehyde from fast pyrolysis of glucose‐based carbohydrates in the presence of NaCl. © 2015 American Institute of Chemical Engineers AIChE J, 62: 778–791, 2016     

Fast pyrolysis of glucose‐based carbohydrates with added NaCl part 1: Experiments and development of a mechanistic model

Sodium ions, one of the natural inorganic constituents in lignocellulosic biomass, significantly alter pyrolysis behavior and resulting chemical speciation. Here, experiments were conducted using a micropyrolyzer to investigate the catalytic effects of NaCl on fast pyrolysis of glucose‐based carbohydrates (glucose, cellobiose, maltohexaose, and cellulose), and on a major product of cellulose pyrolysis, levoglucosan (LVG). A mechanistic model that addressed the significant catalytic effects of NaCl on the product distribution was developed. The model incorporated interactions of Na⁺ with cellulosic chains and low molecular weight species, reactions mediated by Na⁺ including dehydration, cyclic/Grob fragmentation, ring‐opening/closing, isomerization, and char formation, and a degradation network of LVG in the presence of Na⁺. Rate coefficients of elementary steps were specified based on Arrhenius parameters. The mechanistic model for cellulose included 768 reactions of 222 species, which included 252 reactions of 150 species comprising the mechanistic model of glucose decomposition in the presence of NaCl. © 2015 American Institute of Chemical Engineers AIChE J, 62: 766–777, 2016     

Optimization-based strategies for the operation of low-density polyethylene tubular reactors: nonlinear model predictive control

In this work, we present a general nonlinear model predictive control (NMPC) framework for low-density polyethylene (LDPE) tubular reactors. The framework is based on a first-principles dynamic model able to capture complex phenomena arising in these units. We first demonstrate the potential of using NMPC to simultaneously regulate and optimize the process economics in the presence of persistent disturbances such as fouling. We then couple the NMPC controller with a compatible moving horizon estimator (MHE) to provide output feedback. Finally, we discuss computational limitations arising in this framework and make use of recently proposed advanced-step MHE and NMPC strategies to provide nearly instantaneous feedback.     

Optimal Simultaneous Design and Operational Planning of Vegetable Extraction Processes

A general multiperiod linear optimization model is proposed in this study that targets the simultaneous design and operation planning decisions of a multiproduct batch plant for the production of vegetable extracts. A multiperiod environment is considered because of the market and/or seasonal fluctuations. Thereby, the model considers changes from period to period of demands, costs, prices and raw materials supplies. The objective function maximizes the net present value of the profit considering incomes, investments and resources costs, and both product and raw material inventory costs. In the plant design problem, the sequence of operations is already defined and the pursued goal is to determine both unit sizes and its configuration in the plant. Besides the usual duplication in parallel option, a novel design alternative is included which allows adding units in series to perform a given operation. The optimal design is determined by taking into account available discrete sizes of units which corresponds to the real procurement of equipments. The model is formulated by using the linear generalized disjunctive programming (LGDP). A particular plant that produces oleoresins (solvent extracts of herbs and spices) is used to illustrate the proposed approach. Nevertheless, the developed model is general and can thus be applied to any vegetable extraction process.     

Application of Plackett-Burman design and linear programming to light-duty liquid detergent formulation

Plackett-Burman experimental design is applied to a seven-component light-duty liquid detergent formulation to determine which components affect five different properties of the formulation. Regression analysis and linear programming are then applied to the results of the Plackett-Burman analysis. It is shown that the formulation can be optimized by linear programming, even if some of the properties are nonlinear. The procedure saves much of the experimental effort required to find the quadratic and interaction terms for nonlinear models of the properties and the difficulties of optimization with nonlinear constraints.     

A new mechanistic model to predict gas–liquid interface shape of gas–liquid flow through pipes with low liquid loading

Devising a new mechanistic method to predict gas–liquid interface shape in horizontal pipes is concerned in this article. An experiment was conducted to find the pressure gradients of air–water flow through a 1‐in. pipe diameter. Comparing results of model with some experimental data available in the literature demonstrates that the model provides quite better predictions than existed models do. This model also predicts flow regime transition from stratified to annular flow better than Apparent Rough Surface and Modified Apparent Rough Surface models for both 1‐ and 2‐in. pipe diameters. The model also leads to reliable predictions of wetted wall fraction experimental data. Although one parameter of new model was evaluated based on air–water flow pressure loss experimental data for 1 in. pipe, it was considerably successful to predict pressure drop, liquid holdup, stratified‐annular transition and wetted wall fraction for other gas–liquid systems and pipe diameters. © 2014 American Institute of Chemical Engineers AIChE J, 61: 1043–1053, 2015     

Integration of scheduling and control for batch processes using multi‐parametric model predictive control

Integration of scheduling and control results in Mixed Integer Nonlinear Programming (MINLP) which is computationally expensive. The online implementation of integrated scheduling and control requires repetitively solving the resulting MINLP at each time interval. (Zhuge and Ierapetritou, Ind Eng Chem Res. 2012;51:8550–8565) To address the online computation burden, we incorporare multi‐parametric Model Predictive Control (mp‐MPC) in the integration of scheduling and control. The proposed methodology involves the development of an integrated model using continuous‐time event‐point formulation for the scheduling level and the derived constraints from explicit MPC for the control level. Results of case studies of batch processes prove that the proposed approach guarantees efficient computation and thus facilitates the online implementation. © 2014 American Institute of Chemical Engineers AIChE J, 60: 3169–3183, 2014