Recent development of plasma pollution control technology: a critical review

Gaseous pollution control, solid and liquid waste treatments have been commercialized based on incineration, catalysis, adsorption, disposal with landfill, etc. More recently technology based on plasmas has become significant due to the advantages such as lower costs, higher treatment and energy efficiencies, smaller space volume, etc. In order to commercialize this new technology, the treatment rate, energy efficiency of treatment, pressure drop of reactor, reusable by-products production rate, must be improved, based on the identifications of major fundamental mechanism of processes, optimizations of reactor, and power supply for an integrated system. In this work, recent development of plasma pollution control technology was critically reviewed and the principle of processes and reactor technologies were outlined. Special attention will be focused on material processing generated pollutants.     

Recent development of plasma pollution control technology: a critical review

Gaseous pollution control, solid and liquid waste treatments have been commercialized based on incineration, catalysis,adsorption, disposal with landfill, etc. More recently technology based on plasmas has become significant due to the advantages such as lower costs, higher treatment and energy efficiencies, smaller space volume, etc. In order to commercializethis new technology, the treatment rate, energy efficiency of treatment, pressure drop of reactor, reusable by-products production rate, must be improved, based on the identifications of major fundamental mechanism of processes, optimizations ofreactor, and power supply for an integrated system. In this work, recent development of plasma pollution control technology was critically reviewed and the principle of processes and reactor technologies were outlined. Special attention will befocused on material processing generated pollutants.     

Plated-wire technology: A critical review

Electrodeposited cylindrical magnetic film memory technology is reviewed. Extensive references are made to previous work. New data is given in areas not previously reported. Special emphasis is given to the following items: 1) Applications: Plated-wire applications cover the spectrum from 100 to 1000 ns cycle time NDRO memories of 10⁵to 10⁷bits capacity in commercial and military markets. 2) Processing: Substrate preparation and electrochemical processing, as well as alternative magnetic plating solutions, and the control of pH, temperature, flow rate, Ni-Fe ratio, and other variables necessary for high yield plating are reviewed. 3) Aging: The conditions that stabilize the film and the test methods that predict a 10- to 100-year life are reviewed. 4) Testing: A practical approach to continuous production line testing is reviewed. 5) Bit Packing Density: Calculations on magnetization distribution along the wire are compared to experience. Although memory plane geometry is important, the wire characteristics dominate the achievable bit density. Wire diameter, film thickness Hk, and other factors are included in graphs useful for design purposes. 6) Memory Plane Construction: The relative advantages of several different forms are compared. The need for magnetic keepers and their advantages are reviewed. 7) Interactions: New data is presented on some of the effects of variations in word strap alignment and spacing as well as the sensitivity to variation in plated-wire spacing and bending.     

Thermal plasma processing of materials: A review

The use of thermal plasma in materials processing industries is becoming an increasingly active and attractive field for the development of new technology. The potential applications of thermal plasma processing technology cover a wide range of activities, such as: the extraction of metals, the refining/alloying of metals/alloys, the synthesis of fine ceramic powders, spray coatings, and the consolidation and destruction of hazardous wastes. A review of thermal plasma applications in materials processing is presented.     

Non-thermal plasma for oxidation of gaseous products originating from thermal treatment of wastes

A plasma reactor generating non-equilibrium plasma in a gliding discharge was applied as one of the modules of a new laboratory device for hazardous waste destruction. The degradation process of wastes containing an organic part was carried out in two stages. The first one consisted of thermal decomposition of wastes in an inert atmosphere (pyrolysis process in argon flow—the gaseous products are formed from the organic part of wastes). In the second stage products of pyrolysis were oxidized in a gliding discharge. This work was focused on study of the parameters influencing the oxidation process of gases originating from pyrolysis and flowing into the plasma reactor. Oxygen was introduced into the plasma reactor simultaneously with the gases. We investigated two factors significantly affecting the oxidation process: (a) the oxygen concentration in the initial mixture of argon and oxygen and (b) the total flow of argon and oxygen gases. The best oxidation efficiency of the processing gases in the plasma was reached when the oxygen content did not exceed 20% and when the total flow of argon and oxygen was low enough not to cause disturbances of functioning of the plasma reactor.     

Modelling robustness for manufacturing processes: a critical review

‘Robustness’ is an important concept used in quality engineering for the improvement of quality in a manufacturing process. A process which is insensitive to noise variation is called a robust process. The robustness is modelled by several researchers and practioners for its design and implementation in a manufacturing process. A review of all these approaches is essential in order to assess their strengths, limitations and applicability under different process conditions and constraints. Over the years, many of these approaches have found widespread application in measuring, assessing and modelling of process robustness in manufacturing and other industries. In this paper, an attempt has been made to review critically the existing approaches as proposed and applied for measuring and evaluating robustness of manufacturing processes. Based on the critical appraisal, the key issues are identified and a generic framework for modelling and measuring of process robustness in single- and multi-stage manufacturing processes is presented.     

Architecture of the city reinterpreted: a critical review

When Aldo Rossi first published his monograph L'architettura della città in 1966, he probably did not imagine that in 1982 it would not only have been republished three times in Italian, but also translated and published in Spanish (in 1971, with four subsequent republications), German (in 1973), Portugese (in 1977), French (in 1981) and in English.The Graham Foundation for Advanced Studies in the Fine Arts (Chicago) and the Institute for Architecture and Urban Studies (New York) were jointly responsible for the English edition of Rossi's monograph, published by Massachusetts Institute of Technology Press in 1982¹. While the prolific translation and publication of any book is no guarantee of its academic worth, nor its internal coherence, it is rare for a contemporary architectural monograph to generate such wide appeal. Therefore it is interesting and perhaps instructive to analyse Rossi's contribution to current architectural theory, to highlight the merits and shortcomings of his monograph, and to relate his approach to other contemporary contributions, particularly those which explore the mediations between the spatial and the behavioural features of the built environment. This is the purpose of this review paper.     

Processing metal powders via field assisted sintering technology (FAST): a critical review

The current status of field assisted sintering technology (FAST) of structural metals from powder is critically reviewed. Recently, there have been significant increases in the uptake of FAST for metallic systems, composites and porous materials at the laboratory-scale. It is clear that FAST is tolerant of powder/particulate feedstock, allowing rapid production of materials, some of which would be challenging through conventional sintering techniques. Yet, the underlying mechanisms allowing this are not fully understood. Final specimen sizes tend to be small, which restricts rigorous mechanical assessment. This review demonstrates the clear benefits in transitioning laboratory-scale demonstrators to the industrial scale over the next few years. However, consideration will need to be given to size, throughput, and shape complexities to attract commercial investment.     

Bamboo reinforced concrete: a critical review

The use of small diameter whole-culm (bars) and/or split bamboo (a.k.a. splints or round strips) has often been proposed as an alternative to relatively expensive reinforcing steel in reinforced concrete. The motivation for such replacement is typically cost—bamboo is readily available in many tropical and sub-tropical locations, whereas steel reinforcement is relatively more expensive—and more recently, the drive to find more sustainable alternatives in the construction industry. This review addresses such ‘bamboo-reinforced concrete’ and assesses its structural and environmental performance as an alternative to steel reinforced concrete. A prototype three bay portal frame, that would not be uncommon in regions of the world where bamboo-reinforced concrete may be considered, is used to illustrate bamboo reinforced concrete design and as a basis for a life cycle assessment of the same. The authors conclude that, although bamboo is a material with extraordinary mechanical properties, its use in bamboo-reinforced concrete is an ill-considered concept, having significant durability, strength and stiffness issues, and does not meet the environmentally friendly credentials often attributed to it.     

Testing and calculating a two-chamber plasma furnace for processing of radioactive wastes

A two-chamber plasma furnace has been tested and the advantages of the processing of radioactive wastes with the use of plasma-thermal technologies have been demonstrated. A model of a plasma furnace for processing of low-and medium-activity radioactive wastes formed in the process of operation of atomic-power and nuclear-industry plants has been developed. The thermal parameters of such a furnace have been calculated. __________ Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 81, No. 3, pp. 569–576, May–June, 2008.     

钛表面等离子冶金技术的研究

采用双层辉光放电产生的低温等离子体,在工业纯钛表面制备出表面钛合金,已经研究出了钛表面制备Ti-C合金和Ti-Zr合金等工艺方法.     

Wide-angle camera technology for automotive applications: a review

The development of electronic vision systems for the automotive market is a strongly growing field, driven in particular by customer demand to increase the safety of vehicles both for drivers and for other road users, including vulnerable road users (VRUs), such as pedestrians. Customer demand is matched by legislative developments in a number of key automotive markets; for example Europe, Japan and the US are in the process of introducing legislation to aid in the prevention of fatalities to VRUs, with emphasis on the use of vision systems. The authors discuss some of the factors that motivate the use of wide-angle and fish-eye camera technologies in vehicles. The authors describe the benefits of using wide-angle lens camera systems to display areas of a vehicle?s surroundings that the driver would, otherwise, be unaware of (i.e. a vehicle?s blind-zones). However, although wideangle optics provide greater fields of view, they also introduce undesirable effects, such as radial distortion, tangential distortion and uneven illumination. These distortions have the potential tomake objects difficult for the vehicle driver to recognise and, thus, potentially have a greater risk of accident. The authors describe some of the methods that can be employed to remove these unwanted effects, and digitally convert the distorted image to the ideal and intuitive rectilinear pin-hole model.     

Memories for life: a review of the science and technology.

This paper discusses scientific, social and technological aspects of memory. Recent developments in our understanding of memory processes and mechanisms, and their digital implementation, have placed the encoding, storage, management and retrieval of information at the forefront of several fields of research. At the same time, the divisions between the biological, physical and the digital worlds seem to be dissolving. Hence, opportunities for interdisciplinary research into memory are being created, between the life sciences, social sciences and physical sciences. Such research may benefit from immediate application into information management technology as a testbed. The paper describes one initiative, memories for life, as a potential common problem space for the various interested disciplines.     

Development and trials of a technology for reprocessing of NPP liquid radioactive wastes

Laboratory trials of a process for sorption decontamination of real NPP bottom residues from Cs radionuclides with Termoksid-35 ferrocyanide sorbent and rig and pilot trials of the technology for reprocessing of bottom residues from a number of Russian nuclear power plants were performed. The efficiency of the Cs sorption drastically decreases in the presence of organic complexing agents (EDTA, oxalate ions). Preliminary ozonation of the bottom residue allows the working life of Termoksid-35 sorbent in the decontamination process to be increased by a factor of several tens. Rig and pilot trials showed that ozonation of bottom residues, followed by microfiltration separation of the precipitate formed, ensures efficient decontamination of the solutions from Co, Mn, and Sr radionuclides and from α-emitters. A technology was suggested for decontamination of NPP bottom residues from radionuclides, involving ozonation, microfiltration, and selective sorption of Cs radionuclides on Termoksid-35 ferrocyanide sorbent. Process and technical solutions obtained in the course of trials were implemented in an industrial installation for reprocessing of bottom residues from the Kola NPP.     

Numerical simulation of plasma treatment of charge used in vitrification of radioactive wastes

The process of plasma treatment of charge used in vitrification of radioactive wastes is simulated numerically. Optimum conditions providing heating of particles in the charge to vitrification temperatures are determined for a 200-kW reactor.Academic Scientific Complex A. V. Luikov Heat and Mass Transfer Institute, Academy of Sciences of Belarus, Minsk, Belarus. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 68, No. 3, pp. 461–465, May–June, 1995.     

Architecture and behavioural research: a critical review

This paper presents a critical analysis of diverse interpretations of architecture and human behaviour, which have been published in the USA since 1970. Contributions by authors trained in architecture, social anthropology, geography, sociology and psychology are included. It becomes apparent that despite the proliferation of research there is still no comprehensive methodology for the study of the interaction between people and their physical surroundings. Rather, the approach generally adopted by authors in diverse disciplines has been piecemeal. In conclusion, the redefinition and the diversification of research in this field is proposed.     

Thermal treatment of toxic metals of industrial hazardous wastes with fly ash and clay

Waste generated from galvanizing and metal finishing processes is considered to be a hazardous due to the presence of toxic metals like Pb, Cu, Cr, Zn, etc. Thermal treatment of such types of wastes in the presence of clay and fly ash can immobilizes their toxic metals to a maximum level. After treatment solidified mass can be utilized in construction or disposed off through land fillings without susceptibility of re-mobilization of toxic metals. In the present investigation locally available clay and fly ash of particular thermal power plant were used as additives for thermal treatment of both of the wastes in their different proportions at 850, 900 and 950 degrees C. Observed results indicated that heating temperature to be a key factor in the immobilization of toxic metals of the waste. It was noticed that the leachability of metals of the waste reduces to a negligible level after heating at 950 degrees C. Thermally treated solidified specimen of 10% waste and remaining clay have shown comparatively a higher compressive strength than clay fired bricks used in building construction. Though, thermally heated specimens made of galvanizing waste have shown much better strength than specimen made of metal finishing waste. The lechability of toxic metals like Cr, Cu, Pb and Zn became far below from their regulatory threshold after heating at 950 degrees C. Addition of fly ash did not show any improvement either in engineering property or in leachability of metals from the solidified mass. X-ray diffraction (XRD) analysis of the solidified product confirmed the presence of mixed phases of oxides of metals.     

Biodesulfurization: a mini review about the immediate search for the future technology

A major concern among the environmental agencies includes the emission of sulfurous gas into the environment. Consequently, the oil agencies are in constant search of alternative processes aiming the reduction of sulfur content in fuels. One of the technologies commonly used is the hydrodesulfurization (HDS), but this is a high-cost process that also requires high temperature and pressure. A complementary alternative to HDS is biodesulfurization (BDS) involving the use of specific microorganisms to the removal of sulfur present in the carbon chain, using the oxidation pathway “4S”, in which there is cleavage of carbon–sulfur bond, and maintaining the calorific value of the organic molecule. The BDS is a low-cost technique when compared with HDS. For this process to occur, activation of specific enzymes is needed, which is controlled by dszABC genes. Therefore, strategies to optimize this process have been of great importance to the oil refineries. For decades, attempts to try to implement BDS in the industry have been made, but difficulties in obtaining satisfactory results led the researchers to seek new knowledge about this bioprocess. The need of more studies concerning implementation on an industrial scale of this process is evident, since this biotechnology is a promising alternative to refineries in the near future.     

Thermal characteristics of a plasma atomizer

The thermal characteristics of a nitrogen plasma jet are studied. Their dependence on the working conditions and the nitrogen flow rate and their variation along the axis of the jet are demonstrated.