Sodium dithionite and its relatives: past and present

In this paper, the implications of sodium dithionite and of some of its related compounds for the development of chemistry in the twentieth century, as well as their applications in newer fields of chemistry, are described.     

Food colorants: their past,present and future

Whether we are purchasing fresh vegetables from a market stall, ready meals from the supermarket, eating at home or in a five‐star restaurant, we use colour to tell us what to expect in terms of taste, nutrition and safety. This review considers the techniques that have, over the years, been employed to modify the colour of our food, and the interactions of these techniques with issues of safety and nutrition. The demand for brightly coloured food resulted in the incorporation of some questionable inorganic and organic chemistry being used in food products. A limited number of synthetic dyes are still used in food today, but health concerns and the consumer‐driven demand for natural colorants has brought about a change in the way food is coloured. The proliferation of products with labels that state they contain “No artificial colours” on supermarket shelves suggests that the future of azo dyes and their various derivatives is strictly limited. Nature produces an abundance of colours and many of these are extracted and used as natural food colorants; however, they are subject to application limitations and stability problems. Significant research by academia and industry into methods to stabilise and expand the application possibilities for the various approved natural food colorants is ongoing, but most developments that food colour manufacturers proclaim are enhanced vehicles for delivering established natural pigments into food products.     

Model predictive control: past,present and future

More than 15 years after model predictive control (MPC) appeared in industry as an effective means to deal with multivariable constrained control problems, a theoretical basis for this technique has started to emerge. The issues of feasibility of the on-line optimization, stability and performance are largely understood for systems described by linear models. Much progress has been made on these issues for non-linear systems but for practical applications many questions remain, including the reliability and efficiency of the on-line computation scheme. To deal with model uncertainty ‘rigorously’ an involved dynamic programming problem must be solved. The approximation techniques proposed for this purpose are largely at a conceptual stage. Among the broader research needs the following areas are identified: multivariable system identification, performance monitoring and diagnostics, non-linear state estimation, and batch system control. Many practical problems like control objective prioritization and symptom-aided diagnosis can be integrated systematically and effectively into the MPC framework by expanding the problem formulation to include integer variables yielding a mixed-integer quadratic or linear program. Efficient techniques for solving these problems are becoming available.     

荣昌陶传承与发展

荣昌陶四大名陶之一到今为止已有2000多年的历史,曾盛极一时,如今却鲜为人知,悠久的文化历史该如何去传承,新兴一代的发展,该如何去融汇贯通。本文就荣昌陶的传承与发展问题中从他的历史、现状问题、发展建议进行探讨。望作为四大名瓷的荣昌陶艺术文化,能够紧随祖国文化复兴的道路,重焕新生。     

Looking ahead from the past: The heritage of cement chemistry

A review of the proceedings of the successive International Congresses on cement chemistry.     

Prominent frontiers of coal science: past, present and future

More fundamental knowledge of coal in terms of its structure and behaviour during various conversion processes is essential for generating the new technologies that will be required for the efficient and clean uses of coal as an energy source in the future. In this paper, the current state-of-the-science in each of several areas including coal characterization, combustion and liquefaction is discussed, along with suggested research opportunities in each area. These suggestions are coupled with an assessment of the impact such research programmes could have if successful.     

Conductive composites past,present, and future

Conductivity of plastics and polymeric composites is reviewed. The use of various conductivity-enhancing fillers, such as graphite, metallized glass, or stainless steel fibers are discussed. Properties of composites containing rapid-solidified aluminum flakes are of particular interest.     

Panel 1: PVC Resins—past,present and future

PVC Resin behavior vs VCM control; processing differences pre- and early control vs current VCM standards. Differences in fusion, bulk density, output rates—lot to lot variations; differences in plasticizer absorption and response; nature of resin particles surface; drift in K value; static charge; viscosity differences in dispersion resins; S-PVC vs M-PVC; quality control, ASTM D 1755 resin classification.     

PVC Stabilizers of the past,present, and future

When chemical additives were found that could minimize the loss of chemical and physical properties of a thermally-processable but heat-sensitive polymer called poly(vinyl chloride) (PVC), an industry was born. And with it grew the world of plastics additives. Stabilizers for PVC became and industry itself, feeding into and off of this versatile polymer industry, in an almost symbiotic relationship. There have been so many types of stabilizers in use throughout the past fifty years: inorganics, leads, organics, barium/cadmiums, calcium/zincs, organotins, and antimony. And so very many more have been conceived but not commercialized: organoleads, organoantimonys, bismuths, indiums, and a myriad of organic chemicals. What are the merits and deficiencies of these stabilizers? What of yesterday's products are still with us? What are the newer types? What might be tomorrow's products? This paper will attempt to review and discuss the past, present, and future of PVC stabilizers; the factors that are responsible for their variety, for influencing their research, development, and commercialization, and how these factors change with time.     

Coal research in Newcastle—past, present and future

Coal research, particularly in the area of coal utilization, has flourished in the University of Newcastle for last several decades. There have been significant developments in the area of furnace modeling and heat transfer—modeling of radiative heat transfer in pulverized coal fired boilers and aerodynamic modeling of swirl burners, blast furnace raceways, coal combustion—kinetics of devolatilisation, combustion and gasification, mineral and ash reactions—thermal behaviour of different minerals, ash formation and their implications on ash deposition and thermal performance. There have been some investigations into in situ gasification, NO_x formation and cofiring with biomass as well. Coal characterization—for organic and inorganic matter and ash has been a strong activity in the past few years.This paper presents a comprehensive review of these activities summarizing the key achievements in each area. The paper also describes possible directions and drivers for future coal research in the current environment.     

表面活性剂的发展

分析了当前表面活性剂行业所面临的经济形势、法规和环境要求、原材料供应困境、应用技术挑战、市场的变化以及消费者的要求,并从生产技术、品种、价格以及应用等几方面对表面活性剂今后的发展状况做出预测。