Screen Printing Machines for Carpets

A critical comparison is made between the squeegee systems currently used in rotary screen carpet printing. The advantages of each system are discussed. For the majority of carpets all the squeegee systems are capable of producing satisfactory prints.     

Applications of set theoretic methods to color systems

A vector-space approach to color systems has been shown to be useful in describing metameric effects and producing metamers under different illuminations. The vector-space approach has also been used to describe color scanning and reproduction systems. This article extends the applications presented in previous work by introducing set theoretic concepts which allow the addition of realistic constraints. The set theoretic methods allow the full range of solutions of color problems to be explored by allowing a set of solutions to a particular problem formulation. The applications discussed here include producing realizable metamers and the design of scanning filters.     

超高分子量聚烯烃聚合催化剂及聚合工艺

讨论了在超高分子量聚烯烃生产中 ,新催化剂系统、新聚合工艺方法的使用 ,提供了人们在催化剂中选择的改性组分。叙述了在预聚条件下和无预聚条件下 ,得到的超高分子量聚烯烃的物理性能 ,特别是高碳烯烃参与预聚 ,得到了含微量共聚单体的超高分子量聚烯烃。     

A simple illustration of structure-properties relationships for short fiber-reinforced thermoplastics

In this paper, a simple theoretical model for elastic properties of short fiber-reinforced thermoplastic (SFRTP) composite systems is described, which considers the effect of two important structural parameters, viz., fiber aspect ratio distribution and fiber orientation distribution. An experimental technique for producing SFRTP samples featuring a fairly uniform fiber orientation is described, and a broad set of experimental results on the mechanical properties of SFRTP systems based on polystyrene (PS) and polyethylene (PE) resins with several fiber loadings is presented. The use of the simple theoretical model to analyze the experimentally-determined elastic properties is discussed.     

Mathematical modelling of structure formation during combustion synthesis of advanced materials

The synthesis of advanced materials by a wave of heterogeneous combustion propagating through a charge mixture, or the so-called self-propagating high-temperature synthesis (SHS) has many potential advantages over conventional techniques of synthesis. Because of high heating rates, steep temperature and concentration gradients, and fast accomplishment of reactions, the mechanisms of physical, chemical and structural transformations in the SHS wave are intricate and often not known. Further understanding of interaction mechanisms in SHS waves, relating the process parameters to structure and properties of the target material, and the application of SHS to producing final articles necessitates developing mathematical models for SHS-related phenomena.Various aspects of mathematical modelling of SHS are discussed in this paper. They include the analysis of novel factors influencing the structure formation, viz. the heating-to-reaction and mass transfer-to-reaction time ratios, autocatalysis and intrinsic stochasticity, which are unnoticed in traditional synthesis methods. The application of chemical thermodynamics and combustion theory to modelling SHS processes is outlined. Novel mathematical models are developed for SHS on condensed systems, which involve stochastic effects and autocatalysis. New models for solid-gas systems are worked out, which include the reaction kinetics and mass transfer of a gaseous reactant and permit predicting the structure formation pattern in the SHS wave. Application of mathematical modelling to producing porous final articles by means of SHS is discussed.     

燃煤高洁净度干燥介质直接发生系统研究

针对我国的燃料资源特点以及改善干燥工艺经济性的需求，开发了一种以原煤为燃料的直接式干燥介质发生系统。该系统通过机械化给煤、区域控温、多次进风等技术手段实现原煤的脱硫和稳定、高效、高温燃烧，通过多级旋涡凝聚式高温烟气除尘装置实现烟气的净化，通过控温、混风、配风最终得到温度和风量大幅度精确可调的高洁净度干燥介质。与其他干燥介质发生系统相比，该系统可以使生产成本下降20％～50％，可以有效地控制干燥介质中烟尘和硫化物含量，可以用于对纯净度没有过高要求的各种干燥工艺过程。介绍了这种干燥介质发生系统的工艺原理、应用效果、适用领域和发展前景。     

System Study on Hydrothermal Gasification Combined With a Hybrid Solid Oxide Fuel Cell Gas Turbine

The application of wet biomass in energy conversion systems is challenging, since in most conventional systems the biomass has to be dried. Drying can be very energy intensive especially when the biomass has a moisture content above 50 wt.% on a wet basis. The combination of hydrothermal biomass gasification and a solid oxide fuel cell (SOFC) gas turbine (GT) hybrid system could be an efficient way to convert very wet biomass into electricity. Therefore, thermodynamic evaluation of combined systems with hydrothermal gasification units and SOFC–GT hybrid units has been performed. Three hydrothermal gasification cases have been evaluated; one producing mainly methane, a second one producing a mixture of hydrogen and methane and the last one producing mainly hydrogen. These three gasification systems have been coupled to the same SOFC–GT hybrid system. All the integrated systems have electrical exergy efficiencies around 50%, therefore, the combination of supercritical water gasification and SOFC–GT hybrid systems seems promising. The overall system performance depends for a large part on the liquid gas separation. Further research is required for finding out the optimal separation conditions.     

Fuel cells for civil aircraft application: On-board production of power, water and inert gas

Fuel cell systems are regarded as a promising solution for future electrical energy generation on board of commercial aircraft. In addition to an improved efficiency such systems offer the opportunity of producing water usable for on-board purposes and provide additional functions such as inerting (providing a non-inflammable atmosphere) of the jet fuel tank. This paper presents an evaluation and assessment of different system architectures as well as experimental results demonstrating the feasibility of the multiple functions in a laboratory set-up. First, the conventional system requirements and the results reported by the Federal Aviation Administration (FAA) are discussed. A system design evaluation based on simulating cruise and ground operation of aircraft is performed demonstrating the benefits of systems with pressurized hydrogen tank storage and cabin air use. The requirements for a fuel cell system regarding aircraft inerting function are calculated based on the FAA analysis. Experimental results based on laboratory systems confirm the feasibility of the implementation of various functions with a single fuel cell system. Test platforms for further investigation of the systems are shortly described.     

Advances and Challenges on Algae Harvesting and Drying

Biodiesel production from algae offers a promising prospect for practical applications among the still developing biofuel technologies. The fact that algae are capable of producing much more yield provides an edge over other types of biofuel. Though algal biofuel research is still developing and its practical application is yet to be ascertained, promising work on laboratory- and pilot-scale algae harvesting systems has been extensively reported. Because algae harvesting and drying are vital elements in biofuel production, recent advances on various algae harvesting, dewatering, and drying technologies are reviewed and discussed. Challenges and prospects of algae harvesting and drying are also outlined.     

Experience in commissioning large desalination plants in the Middle East

Aspects of the design and construction of three major seawater MSF installations, with some 14 evaporators each producing about 5 mgd (22,000 m³/day) are briefly reviewed.Initial problems were encountered with brine weir design at high brine rates, and painting. Remedial action was successfully incorporated in later plants in spite of the short timescale available.Recirculating brine pump sizing criteria and the performance of the on-load tube cleaning systems, and an external deaerator, are discussed.After-condenser corrosion on air ejector systems is also reviewed.Some modifications to plant specifications are suggested in the light of experience gained with these units.     

A Review of Membrane Materials for Ethanol Recovery by Pervaporation

Due to an emerging scarcity of oil resources and an associated increase of oil prices, biofuels (e.g., ethanol) play an important role in the energy crisis. Fermentation is a common process for producing ethanol from renewable biomass. Pervaporation is an attractive technique for the recovery of ethanol from the fermentation systems. Separation membrane is the key element in the pervaporation separation equipments. In this article, the pervaporation performances of ethanol-permselective membranes presented in the recovery of ethanol from dilute ethanol aqueous solution are reviewed. An analytical overview on the challenges and opportunities, and the prospect of ethanol-permselective membranes by pervaporation is also discussed.     

Effects of Magnetic Fields on Polymer Liquid Crystals

Abstract

The effects of magnetic fields on polymer liquid crystals (PLCs) are analyzed, dealing in turn with isotropic solutions, lyotropic LCs (including polypeptides, polyribonucleotides and DNA) and thermotropic PLCs (including polyesters and polypeptides). Looking for a common denominator in LC behavior, living systems are also analyzed, including viruses, biological membranes, sperm nuclei, rhodopsin and fibrinogen. Magnetropism is discussed, as are applications of PLC oriented in magnetic fields for the purpose of producing ultra-high modulus materials.     

Jet printing

Ink jet printers, some capable of producing a full colour gamut, are now widely used as output devices for computer-generated design work. Some advances have been made in the application of these ink jet paper printing technologies to textile printing, mainly for carpets. This review describes the principal jet systems that have been developed commercially for both textile and reprographic uses, and indicates areas in which the ink jet principle appears to have future potential. The physical and chemical requirements of the inks used in the different systems, as well as the possible pretreatment of the substrate to improve ink receptivity and the durability of the print, are also discussed.     

硝酸钾的生产方法及发展前景

介绍了硝酸钾主要性质、用途和作为无氯钾肥的优点 ,概述了国内外硝酸钾主要生产工艺 ,并对各种工艺技术进行了比较 ,分析了国内外硝酸钾生产市场及需求情况 ,提出我国硝酸钾的发展前景和国内硝酸钾企业的发展方向     

Scoping biology-inspired chemical engineering

Biology is a rich source of great ideas that can inspire us to find successful ways to solve the challenging problems in engineering practices including those in the chemical industry. Bio-inspired chemical engineering(Bio Ch E)may be recognized as a significant branch of chemical engineering. It may consist of, but not limited to, the following three aspects: 1) Chemical engineering principles and unit operations in biological systems; 2) Process engineering principles for producing existing or developing new chemical products through living ‘devices';and 3) Chemical engineering processes and equipment that are designed and constructed through mimicking(does not have to reproduce one hundred percent) the biological systems including their physical–chemical and mechanical structures to deliver uniquely beneficial performances. This may also include the bio-inspired sensors for process monitoring. In this paper, the above aspects are defined and discussed which establishes the scope of BioChE.     

Powder mixing: theory and practice in pharmacy

Power mixing in pharmacy is still largely empirical. There are few controls on individual doses, the notable exception being in the United States, where tablets containing 50 mg or less of drug must be assayed individually. Less stringent controls are likely to be introduced elsewhere.Where powder mixing theory is used, it is largely based on the experiences of academic chemical engineers using non-cohesive binary particulate systems. Thus the theoretical comoletely randomised system is taken as the limiting value for assessment of degree of mixing or evaluation of mixer performance. In contrast to the non-cohesive binary systems which the industry uses as a basis, the problems dealt with in practice involve cohesive multicomponent systems.The use of homogeneity assessment for mixer performance and for degree of mixing in pharmaceutical practice is described. With cohesive materials, ordered mixing may be as important as randomisation for producing pharmaceutical mixtures. The use of these concepts in overcoming some of the real problems met with in pharmacy is discussed, together with ways of avoiding some of the problems.     

Solvent extraction of soybeans

The removal of edible oils from oilseeds was practiced by the Egyptians many centuries ago. Some of the developments leading to today’s worldwide extraction industry are discussed, and a brief history of the industry in the United States from 1940 to the present is included. The theory of solvent extraction is outlined in practical terms. Several types of solvent extraction and desolventizing systems are explained. Also, typical preparation and extraction processes for presscake, soybeans, and some high oil content seeds are illustrated. Some reasons for taking extra precautions in the preparation process and the desolventizing process when producing human edible soy protein products are explained. Energy conservation suggestions are included.     

Oxidative dehydrogenation of ethane and propane: How far from commercial implementation?

This review examines the recent literature on the oxidative dehydrogenation (ODH) of ethane and propane, which aims for the synthesis of the corresponding alkenes. The following aspects are discussed: (a) the main features affecting the catalytic properties of systems based on supported vanadium oxide and molybdenum oxide; (b) the characteristics of catalysts producing outstanding olefin yields; (c) advantages in selectivity gained by means of either special reactor configurations or non-conventional conduction of the reaction; (d) the contribution of homogeneous reactions to the formation of olefins during the oxidation of alkanes.     

A review of Znln2S4-based photocatalysts for producing hydrogen by water splitting under visible light: Fundamentals and recent advancements

Hydrogen (H₂) is a clean energy carrier widely used in oil refineries, fertilizers, chemicals, and steel manufacturing. Presently, the majority of H₂ is produced from either steam methane reforming of natural gas or coal gasification; however, these technologies result in a massive amount of CO₂ emission. Alternatively, the use of photocatalysts for producing H₂ via water splitting is an eco-friendly and sustainable approach, among which the selection of highly efficient, stable, and cheap photocatalysts is the key. In this review, Znln₂S₄-based photocatalysts are thoroughly described in terms of the fundamentals and thermodynamics of water splitting, fabrication methods, and different heterostructure photocatalytic systems. After this, recent developments in the large-scale implementation of photocatalytic reactors are discussed. Finally, a summary of future research directions and major conclusions is provided. With proper modification, such as heterojunction systems and the selection of proper fabrication methods, Znln₂S₄-based photocatalysts could be superior materials for water splitting. In short, this review article could offer meaningful and useful insights and guidance for the development of Znln₂S₄-based photocatalysts in water splitting for producing H₂ under visible light.     

Microfluidic reactor with immobilized enzyme-from construction to applications: A review

Microfluidic, as the systems for using microchannel (micron-or sub-micron scale) to process or manipulate microflow, is being widely applied in enzyme biotechnology and biocatalysis. Microfluidic immobilized enzyme reactor (MIER) is a tool with great value for the study of catalytic property and optimal reaction parameter in a flourishing and highly producing manner. In view of its advantages in efficiency, economy, and addressable recognition especially, MIER occupies an important position in the investigation of life science, including molecular biology, bioanalysis and biosensing, biocatalysis etc. Immobilization of enzymes can generally improve their stability, and upon most occasions, the immobilized enzyme is endowed with recyclability. In this review, the enzyme immobilization techniques applied in MIER will be discussed, followed by summarizing the novel developments in the field of MIER for biocatalysis, bioconversion and bioanalysis. The preponderances and deficiencies of the current state-of-the-art preparation ways of MIER are peculiarly discussed. In addition, the prospects of its future study are outlined.