SHS extrusion: An overview

Overviewed is the state-of-art in the science and technology for extrusion of still hot SHS products (also termed SHS extrusion). Addressed are the experimental and theoretical studies on rheological behavior of materials with a limited duration of their ductility. The structures/properties of extruded materials and items are also presented and discussed. Presented are the examples of practical implementation of the process to production of rod-like electrodes for electrospark alloying from new multifunctional materials, such as nanograined cermets, MAX compounds, and intermetallics.     

SHS in Italy: An overview

In this work, the evolution of SHS research and development taking place in Italy during the last twenty years are addressed. The activity performed by the Italian research groups involved in this field that belong to the Universities of Cagliari, Genoa, Pavia, and Sassari, Polytechnic of Turin, and National Research Council IENI-Milan, respectively, are presented. The major results obtained from both the modeling and experimental points of view are reviewed while highlighting the international collaborations of each research group. Presented at the International Conference on Historical Aspects of SHS in Different Countries, October 22–27, 2007, Chernogolovka, Moscow, Russia.     

Effect of batch pelletizing on a course of SHS reactions: An overview

Such a simple technological trick as pelletizing (granulating) green powder mixtures (popular in conventional powder technology) has seldom been used in SHS technology. We have demonstrated that pelletizing green powder mixtures can markedly affect the parameters of various SHS reactions (SHS in a mode of infiltration-mediated combustion, SHS with a reduction stage, combustion of thermit mixtures, SHS in aluminum melt) and properties of their products.     

Coupled SHS Reactions as a useful tool for synthesis of materials: An overview

Considered were the thermodynamic and kinetic aspects for different kinds of coupled SHS reactions: thermally coupled, chemically coupled, and thermochemically coupled ones. Thermodynamic calculations confirmed the applicability of coupling as a useful route to materials synthesis in a one-step combustion process.     

SHS of ultrafine and nanosized refractory powders: An autoreview

Overviewed are some results of our recent works aimed at the synthesis of ultrafine and nanosized refractory powders by SHS combined with chemical dispersing of combustion products. The microstructure of synthesized powders was found to depend on the type and amount of added modifying agents. Successive chemical dispersing of raw products with solutions of different acids, alkalis, and salts leads to an increase in the specific surface and a decrease in the particle size caused by dissolution and wash-out of the impurities and intermediate products present in raw products. Our experience in preparation, separation, and purification of SHS-produced nanopowders can be used as a basis for elaboration of general methodology for pilot-scale production of nanostructured compounds and composites.     

Mathematical modeling of SHS compaction/extrusion: An autoreview

Overviewed are general approaches to mathematical modeling of SHS compaction/extrusion. Presented are some examples of successful implementation of modeling predictions in technological practice.      

Green composites: An overview

The use of natural fibers to reinforce polymers is a well‐established practice, and biocomposites are increasingly used in sectors such as automotive and construction. Green composites are a specific class of biocomposites, where a bio‐based polymer matrix is reinforced by natural fibers, and they represent an emerging area in polymer science. This work discusses the environmental benefits deriving from the use of natural fibers in polymer composites and from substitution of oil‐derived polymers by bio‐based polymers as matrix material. New trends in the selection of natural fibers, that is, from waste rather than from valuable crops are described. Recently developed thermoplastic and thermosetting bio‐based polymers are reviewed, and commercially available green composites obtained thereof are discussed. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers     

Animal cell technology: An overview

The review focuses attention on the different kinds of equipment which are used to grow large quantities of the two types of animal cells; the monolayer or surface-dependent cell and the suspension or surface-independent cell. The methodologies used to obtain reliable performance are described as are some examples of the application of microprocessors to monitor and control operational parameters. The kinds of products which are currently obtained from animal cells are listed and the future potential of genetically engineered animal and prokaryotic cells is discussed.     

Metallurgical SHS Processes as a Route to Industrial-Scale Implementation: An Autoreview

The paper addresses to the practical development of a novel process technology for large-tonnage SHS-production of alloying agents and master alloys–metallurgical SHS process technology. The suggested and tested technique is based on use of various metallurgically produced allows, including dusty wastes of ferroalloy plants. The replacement of high-purity starting powders by less expensive and accessible ferroalloys afforded for transition from existing laboratory-scale fabrication of SHS materials to large-tonnage SHS manufacture.     

Flame synthesis of carbon nanomaterials: An overview

The synthesis of fullerenes, carbon nanotubes, and superhydrophobic soot in hydrocarbon flames was briefly overviewed.     

Chemical ecology of marine organisms: An overview

An overview of marine chemical ecology is presented. Emphasis is placed on antipredation, invertebrate-toxic host relationships, antifouling, competition for space, species dominance, and the chemistry of ecological interactions.     

Soybean protein in human nutrition: An overview

The nutritional value of processed soy protein in human protein nutrition is reviewed on the basis of growth, nitrogen balance and metabolic studies in infants, children, adolescents and adults. When well processed soy products serve as the major or sole source of the protein intake, their protein value approaches or equals that of foods of animal origin, and they are fully capable of meeting the long term essential amino acid and protein needs of children and adults. The significance of the sulfur amino acid content of soy protein for practical human nutrition is also examined. For young children and adults, under conditions of normal usage of soy protein, it is concluded that methionine supplementation of good quality products is unnecessary and possibly undesirable. For feeding of the newborn, the limited data available suggest that supplementation of soy-based formulas with methionine may be beneficial. However, the appropriate level of supplementation is considerably less than that suggested from results obtained in rat feeding studies. At total protein intakes that approximate current dietary protein allowances, well processed soy protein products can replace meat and fish proteins without reducing the utilization of dietary nitrogen in adults, and they can serve as nutritionally valuable protein sources in cereal-based diets for child feeding. The value of long term studies concerned with tolerance to and acceptability of new soy protein products in adults is emphasized, and favorable results with two isolated soy protein products are described. The data indicate that properly processed soy protein foods are well tolerated and of good protein value for humans of all ages.     

Bioceramic coatings on metallic implants: An overview

Metallic implants sometimes fail in orthopedic surgeries due to insufficient bio-functionality, implant-associated infections, poor osteointegration due to high inertness (Ti, Co–Cr, stainless steel alloys), and a too fast degradation rate (Mg-based alloys). Bioceramic coatings are among the most appropriate solutions for overcoming these drawbacks. After providing a picture of the history as well as the pros and cons of the different types of metallic implants, this review focuses on bioceramic coatings that can be applied on them, including metal oxides, calcium phosphates, silicates, glasses, glass-ceramics, carbon, etc. Various coating strategies and applications are described and discussed, with emphasis on a selected number of highly promising researches. The major trends and future directions in the development of bioceramic coatings are finally suggested.     

Process control: An overview and personal perspective

This paper presents an overview and personnal perspective on recent developments and current practice in computer process model. The basic concepts behind conventional process control are reviewed to provide a starting point for the non-control specialist and process engineer. The ensuing sections on Internal Model Control (IMC), Model Predictive Control (MPC) and adaptive control illustrate the evolution of control technology from the traditional multiloop strategies to the modern, multivariable, model-based, computer control systems now being used in industry. The paper does not provide a complete, critical review of process control. However, the discussion and the recommended references should provide a good starting point for anyone wanting to become familiar with current practice and some of the new directions of process control.     

An overview of caprolactam synthesis

Caprolactam is the precursor of many industrial chemical productions as in nylon industry, plastic industry, paint industry, lysine synthesis and cross-linking for polyurethanes. The production of caprolactam has been focus much from last three decades among the scientific community to fulfill the industrial need under environment precautions. Herein a sequential and explanatory review broadly covering the transformation of a different substrate as cyclohexanone oxime, cyclohexanone, cyclohexanol, cyclohexane, and biorenewable sources into caprolactam is presented. For every substrate, a wide range of catalyst including homogeneous as well as the heterogeneous system has been deeply considered. This study will be helpful for developing alternative industrial route for production of caprolactam.     

An overview of subspace identification

This paper provides an overview of the state of the art of subspace identification methods for both open-loop and closed-loop systems. Practical considerations and future directions are given at the end of the paper.     

Carbon aerogels for catalysis applications: An overview

Carbon aerogels are nanostructured carbons obtained from the carbonization of organic aerogels, which are prepared from the sol-gel polycondensation of certain organic monomers. These materials have a great versatility both at the nanoscopic level in terms of their pore texture and at the macroscopic level in terms of their form. Thus, the surface area, pore volume, and pore size distribution are tuneable surface properties related to the synthesis and processing conditions, which can produce a wide spectrum of materials with unique properties. In addition, carbon aerogels can be obtained in the form of monoliths, beads, powders or thin films. All these properties make them promising materials for application in adsorption and catalysis. Metal-doped monolithic organic aerogels can be easily prepared by following three main strategies: by addition of the metal precursor to the initial mixture, by ion-exchange or by deposition of the metal precursor on the organic or the carbon aerogel by one of various methods. These metal-doped carbon aerogels have been used as catalysts and as electrodes for electrical double-layer capacitors. This article shows the preparation of metal-doped carbon aerogels, their physico-chemical surface properties and their applications as catalysts in various reactions.