Indoor Air Quality: Exploring Policy Options to Reduce Human Exposures

Deciding between the different policy approaches available for reducing human exposures to indoor pollutants is an exceptionally complex task. These options can range from waiting until more definitive information is available to enacting regulatory standards, with many variations in between. This paper presents some of the factors policy-makers must consider in establishing indoor air quality policies, and the role researchers should play in ensuring that indoor air policies are based on the best available scientific information.     

The segmented bidirectional single-loop topology for material flow systems

This paper introduces the segmented bidirectional single-loop (SBSL) flow topology for carrier-based material handling systems. This configuration is based on a single-loop flow-path structure that is divided into non-overlapping segments, each containing a single carrier operating in a bidirectional mode. The design procedure comprises a 0 - 1 mixed-integer formulation to determine the single-loop including the pickup and delivery station location. The second stage is a segmentation procedure to determine the non-overlapping segments in the loop. Finally the performance of the SBSL is evaluated by means of simulation.     

Design of self-regulating production control systems by Tradeoffs Programming

Self-regulating Production Control Systems (SPCSs) include production control systems such as kanban, buffered lines, base-stock, and their variations and combinations. In this work we develop and implement, for SPCS design, a new simulation-based optimization method called Tradeoffs Programming (TOP). TOP is a technique closely related to multi-objective dynamic programming that attempts to optimize inseparable problems. TOP is based on the idea that given correctly defined performance measures, many systems are nearly separable, and we can decompose the overall system using efficiency frontiers of simulated performance measures of the subsystems. We apply this technique to SPCS design and perform a number of experiments to validate and analyze our algorithm. We find TOP to be very accurate, extremely robust, and widely applicable.     

常压蒸馏塔的严格在线模型与仿真研究

基于虚拟组分的概念，通过列写带有汽提塔的改进的MESH方程，并使用BP－SR结合算法，建立了一个实际的工业常压蒸馏塔的严格机理模型。同时，以原油物性实时估算、现场数据协调及塔板温度校正为基础，实现了该模型的在线运行，以适应各种不同的原油混炼和加工方案。该模型已成功地应用于某炼油厂常压蒸馏塔，井针对实际生产工况，给出了模型仿真计算的结果。     

汽车用粉末冶金铝基自润滑材料

简要地介绍了粉末冶金铝基材料的制造工艺特点与材料特性,说明了铝基自润滑材料的性能及其在汽车上的应用情况。     

Melanin-Like Nanomedicine in Photothermal Therapy Applications

Photothermal therapy (PTT) mediated by nanomaterial has become an attractive tumor treatment method due to its obvious advantages. Among various nanomaterials, melanin-like nanoparticles with nature biocompatibility and photothermal conversion properties have attracted more and more attention. Melanin is a natural biological macromolecule widely distributed in the body and displays many fascinating physicochemical properties such as excellent biocompatibility and prominent photothermal conversion ability. Due to the similar properties, Melanin-like nanoparticles have been extensively studied and become promising candidates for clinical application. In this review, we give a comprehensive introduction to the recent advancements of melanin-like nanoparticles in the field of photothermal therapy in the past decade. In this review, the synthesis pathway, internal mechanism and basic physical and chemical properties of melanin-like nanomaterials are systematically classified and evaluated. It also summarizes the application of melanin-like nanoparticles in bioimaging and tumor photothermal therapy (PTT)in detail and discussed the challenges they faced in clinical translation rationally. Overall, melanin-like nanoparticles still have significant room for development in the field of biomedicine and are expected to applied in clinical PTT in the future.     

Canadian dietitians' use and perceptions of glycemic index in diabetes management.

PURPOSE: Several health organizations, including the Canadian Diabetes Association, advocate use of the glycemic index (GI) in the nutritional management of diabetes. However, the clinical utility and applications of the GI remain controversial. Our goal was to determine, via a postal survey, whether dietitians were using the GI and barriers to its use if they were not. METHODS: This cross-sectional study was conducted in 2003. Members of Dietitians of Canada and the Ordre professionnel des diététistes du Québec (n=6,060) were first contacted by mail to identify those working with individuals with diabetes. Among respondents (n=2,857), 1,805 worked with individuals with diabetes and were sent a questionnaire. Using Chi-square analyses, users and nonusers were compared for their professional characteristics, perceived benefits, barriers, general knowledge about the concept, and confidence in teaching the GI. RESULTS: Among questionnaire respondents (n=1,057), 39% (n=415) used the GI and 61% (n=642) did not. Overall, users were more likely to have a greater diabetes patient caseload, perceived greater benefits and had greater confidence in teaching the concept. Nonusers cited lack of teaching tools and lack of knowledge on how to teach the concept as major barriers. CONCLUSIONS: Further research is required to identify the clinical reasoning that triggers dietitians to apply the concept in their practice.     

Real-time optimization under parametric uncertainty: a probability constrained approach

Uncertainty is an inherent characteristic in most industrial processes, and a variety of approaches including sensitivity analysis, robust optimization and stochastic programming have been proposed to deal with such uncertainty. Uncertainty in a steady state nonlinear real-time optimization (RTO) system and particularly making robust decisions under uncertainty in real-time has received little attention. This paper discusses various sources of uncertainty within such closed loop RTO systems and a method, based on stochastic programming, that explicitly incorporates uncertainty into the RTO problem is presented. The proposed method is limited to situations where uncertain parameters enter the constraints nonlinearly and uncertain economics enter the objective function linearly. Our approach is shown to significantly improve the probability of a feasible solution in comparison to more conventional RTO techniques. A gasoline blending example is used to demonstrate the proposed robust RTO approach.     

弦支穹顶节点位移风振系数分析

弦支穹顶结构由于其本身的结构特点,风荷载常常起主要甚至决定性作用.通过时程分析的方法,得到弦支穹顶结构的节点位移风振系数,为弦支穹顶结构实用抗风设计提供参考.     

Experiences in applying data‐driven modelling technology to steelmaking processes

Experience has shown that data‐driven modelling methods are useful for improving steelmaking processes. In particular, principal components analysis and partial least squares are well‐suited for industrial implementation because they address practical issues such as colinearity and missing data. In the course of applying these multivariate methods on‐line, a need for a flexible computer infrastructure to better support data handling and model implementation was identified and met with an internally developed software calculation platform. Multivariate methods have been found useful for monitoring and for prediction and can also be applied as a foundation for other methods such as optimization.