THz Absorption Spectra of Fe Water Complexes Interacting with O3 Calculated by Density Functional Theory

The need for better monitoring of water quality and levels of water contamination implies a need for determining the dielectric response properties of water contaminants with respect to electromagnetic wave excitation. In addition to monitoring contaminants, there is an associated need for monitoring chemical processes that are for deactivation or assistance in the removal of water contaminants. Iron and manganese are two naturally occurring water contaminants, where iron is in general at much higher concentrations. Correspondingly, a process that is highly effective for assisting filtration of water contaminants, including iron and manganese, is the addition in solution of Ozone, i.e., the preozonation process. The present study uses density functional theory (DFT) for the calculation of ground-state resonance structure associated with Fe water complexes interacting with Ozone in solution. The calculations presented are for excitation by electromagnetic waves at frequencies within the THz range. Dielectric response functions can provide for different types of analyses concerning water contaminants. In particular, dielectric response functions can provide quantitative initial estimates of spectral response features for subsequent adjustment with respect to additional information such as laboratory measurements and other types of theory-based calculations. In addition, with respect to qualitative analysis, DFT-calculated absorption spectra provide for molecular level interpretation of response structure. The DFT software GAUSSIAN was used for the calculations of ground-state resonance structure presented in this article.     

THz Absorption Spectra of Fe and Mg Water Complexes Calculated by Density Functional Theory

Monitoring of water contaminants implies a need for determining their dielectric response properties with respect to electromagnetic wave excitation at various frequencies. Iron is a naturally occurring water contaminant, which is the result of decaying vegetation and is at much higher concentrations than any other metal contaminant. The present study uses density functional theory (DFT) for the calculation of ground state resonance structure and stability analysis of Fe water complexes. The calculations presented are for excitation by electromagnetic waves at frequencies within the THz range. Dielectric response functions calculated by DFT can be used for the analysis of water contaminants. These functions provide quantitative initial estimates of spectral response features for subsequent adjustment with respect to additional information such as laboratory measurements and other types of theory-based calculations. In addition, with respect to qualitative analysis, DFT calculated absorption spectra provide for molecular level interpretation of response structure. The DFT software GAUSSIAN was used for the calculations of ground state resonance structure presented here.     

Enhancement of Service Life of Steam Generating Tubes in Oil-Fired Boiler for Power Generation Employing Plasma Spray Technology

The effects of Ni-50 mass% Cr alloy coating, that is plasma-sprayed onto the fire-side of steam generating tubes in a heavy oil-fired boiler, on the high temperature corrosion resistance were examined. One of the severe environments in the industrial manufacturing facilities, where thermal sprayed coatings are employed, is the high temperature corrosion such as the oxidation, sulfidation, and low melting fuel ash corrosion in the fire-side of boiler tubes. In the fossil fuel-fired steam generating boiler facilities, the degradation or failure of steam generating tubes that were derived from the contaminants in a lower grade fuel have often occurred. The situation of degradation of the water evaporator and superheater tubes and corrosion-preventing effects of plasma sprayed coating are described. The enhanced effects of plasma sprayed Ni-50 mass% Cr alloy coating for the suppression of hot corrosion failure of the steam generating tubes of boiler are summarized.     

Untersuchungen zur Rißkorrosion hochfester Seildrähte durch Schwitzwasser

Investigations into stress corrosion of high strength rope wires in condensating water In stress corrosion tests uncoated, galvanized and aluminized rope wires were submitted to the influence of periodically condensating water. Real concentrations of atmospheric contaminants as chlorides, carbon dioxide and sulfur dioxide were added, too. Fractures only were caused under conditions of crevice corrosion as in covered zones. The added contaminants and contact elements, too, did not especially influence fractures. Under the fixed test conditions the life time of the galvanized wires was reduced in relation to the uncoated and aluminized wires.     

Interface adhesion: effects of plasticity and segregation

The adhesion at interfaces between dissimilar materials is strongly affected by both segregation and the extent of plasticity in the adjoining material, particularly when one of these is a metal (or thermoplastic). It will be shown that these interfaces when clean, are generally strong and tough, such that failure occurs in one of the adjoining materials, rather than at the interface. However, segregrants and contaminants often embrittle and weaken the interface, especially in combination with ambient moisture. The embrittlement is obviated either by alloying with elements that “getter” the contaminants or by using an “adhesion layer” that has essentially the same effect: Cr and Ti are particularly effective gettering elements. Models that relate these effects to fundamental material parameters through non-dimensional indices are described. They comprise linkages between atomistic and continuum, enabled by implementation of a plasticity length scale, within the context of a crack growth simulation routine. Comparison with the experimental results is conducted, leading to suggestions for development of a predictive scheme.     

Application of electrodialysis technique to recover contaminated rinsing water from gold electroplating processes

Abstract

The aim of the present work was to evaluate the possibility of using an electrodialysis technique to recover rinsing water contaminated with the electrolyte during the process of gold electrodeposition. During the rinsing process the electrolyte, containing gold, silver, cyanide and contaminants, is dragged from the bath with the plated components. The more the rinsing water is used the more it becomes concentrated and therefore water replacement is necessary. In these studies three different types of electrodialysis cell containing two, three and five separate compartments were used. Two kinds of ion selective membranes, a cationic Nafion 450 and an anionic Selemion AMV, were used in the construction of the cells. The total cell potential, membrane potential and polarisation potential as a function of applied current were evaluated. The results show that it is possible to extract an average of 56% of all metal and cyanide from the rinse water working at 30 mA cm^?2 for 190 h. However, a more efficient extraction of 75% of all the metals and cyanide was obtained within 270 min of electrodialysis at a current density of 20 mA cm^?2. The results of this study showed that electrodialysis is suitable for removing contaminants from rinsing water to be returned to the process.     

Corrosion and Corrosion Prevention in Airframes

Abstract

The materials and construction of airframes, and the environmental conditions in which they operate, are described, and resulting corrosion problems are discussed in terms of the contaminants which produce them. It is concluded that, owing to the limited maintenance times available during the operating life of an aircraft, corrosion prevention must be undertaken during the design and production stages.     

SEM/EDX和FTIR在手机电触点失效分析方面的应用

总结了SEM/EDX和FTIR在手机电触点失效分析中的几个典型案例,发现大量失效产品中的镀金触点因表面污染和氧化引起的接触电阻升高是造成电接触故障的主要原因。污染物形貌和成分复杂,通过与手机生产和使用中常见污染源的红外图谱和EDX图谱进行对比,SEM/EDX和FTIR能鉴别出大多数污染物,比如印刷线路板在切板过程中引起的碎屑、手指接触污染、灰尘聚集污染以及工艺带入的粘胶污染等,促进了工艺的改进和生产效率的提高。     

Solar energy conversion through seaweed photosynthesis and zero emissions power generation

The present paper is aimed at describing a “closed cycle” power plant scheme (Solar Oxygen Fuel Turbine (SOFT)) with macroalgae (seaweed) cultivation in a pond, combustion of its organic matter in a fluidized bed boiler using the Rankine cycle, and return of the combustion products to the pond to feed the algae. The oxygen used for combustion is released to the atmosphere during photosynthesis. It is further elaborated in a paper presented at ECOS2005 in Trondheim. As a renewable fuel, the seaweed Ulva lactuca is selected. Its growth rate in many experiments (in the literature) is 0.1–0.2 per day, the heating value of its dry weight is 19 MJ/kg, and its optimal concentration in salt water is 1:1000. The energy efficiency is less than in photovoltaics, but the energy expenditures to construct the pond as a solar energy receiver are much less, so it gives some economic benefits. For a power unit of 100 kW, the pond surface is about 4 hectare. The cultivation of seaweed in sea-water ponds is well developed in Italy and Israel for water cleaning and chemical production. Construction in the future of a SOFT system near the Dead Sea in the Israeli desert would provide the country with needed power, chemicals, and fresh water using solar energy. The system is protected by United States Patten no. 6 477 841 B1 dated 12.11.2002 with priority in Israel dated 22.03.1999. Many more benefits to the customer than are in the patent text are highlighted in the paper, including fresh water by desalination. In view of the active work in Italy on water cleaning using Ulva and contaminants in the water as nutrients for an increase of the biomass productivity, an additional target of the SOFT cycle might be incineration. Some suppositions of the use of a desert surface for massive scale use of ponds are given.     

Influence of solid contaminants in oil on wear characteristics of nano-Al2O3／Ni composite coating

Solid conlaminants in Iubrication system will cause severe wear of sliding components. In order 1o improve the wear resistance of the material in oil containing solid contaminants, the brush plated nano-Al2O3/Ni composite coating was prepared and the influence of the sand content and sand size on the tribological property of the coating in oil containing solid contaminants was tested with ball-on-disc tester. The results show that the wear volume increases with increasing the sand content and sand size, and the wear resistance of the composite coating is 20% higher than that of the high-speed plain nickel coating. The main wear mechanisms of the coatings are abrasive wear and adhesive wear. And due to the nano-particle strengthening effect, the wear resistance of the composite coating is improved.     

基于双极膜水解离的超纯水电解加工研究

研究了双极膜在超纯水中的工作特性,提出了应用双极膜水解离进行超纯水电解加工的方法,并进行了加工实验.结果表明:在强电场作用下,双极膜促使了水的解离,电流密度可达到2.8 A/cm2,实现了小孔的超纯水电解加工.     

XPS STUDIES OF OXIDATION BEHAVIOR OF NICKEL AND THERMAL STABILITY OF SURFACE OXIDES

Surface oxidation of polycrystalline nickel foil in air and pure water at different temperaturesand the thermal stability of the surface oxides have been investigated by means of XPS.In ad-dition to NiO,Ni_2O_3 is formed especially after long periods of air exposure.Nickel surfacesare much less reactive to pure water than to air.The thermal stability of the surface oxides isrelated to oxidative temperature.The surface species of oxides formed by air exposure attemperatures below 120℃ can be reduced into nickel metal after heating the sample in vacuumat 300℃ for only 10 minutes (in the case of room temperature) to 1 h (in the case of 120℃).This reduction is caused by reaction with surface carbon contaminants.However,the surfacespecies of nickel oxides formed by air exposure with heating at temperatures above 200℃ cannot be reduced into metal after heating the sample in vacuum at 300℃ for 1h.     

Preventing Environmental Contamination by Nonionic Surfactants and Nickel

Protecting the environment from contamination by heavy metals and nonionic surfactants, the sorption of oxyethylated alcohols OS-20, alkylmonoethers ALM-10 and nickel has been investigated, on the hydrogen form of Purolite C 106 cation exchanger. The problem is that nonionic surfactant is not removed by conventional ion exchange. Sorption isotherms were measured, coefficients for intraparticle diffusion were calculated. The sorption of nonionic surfactant from the solution, containing 10 mmol/l, amounts to 400 mg/g for OS-20 and 500 mg/g for ALM-10. The presence of nickel has no appreciable effect on the rate of intraparticle diffusion and the equilibrium sorption of surfactant. The sorption of nickel takes place in the form of both free cations and cations bonded with surfactant.

The sorption of nonionic surfactant and nickel in Purolite C 106 cation exchanger was found to be suitable for the simultaneous removal of both contaminants in order to reuse the water, recovered from nickel plating rinsewater, preventing the contamination of environment.     

影响TiO2催化降解有机物废水效率的主要因素

介绍了近年来国内外有机物废水光催化降解的研究现状，及不同催化剂体系对各种有机物的降解效果。通过对以TiO2为主的光催化剂在不同催化剂结构和不同反应因素等条件下降解效果的比较，论述了TiO2光催化剂的优越性、不足和影响机制。并指出了光催化降解有机物废水技术需要进一步解决的问题。     

UHV arc for high quality film deposition

The vacuum arc is a well-known technique for producing coatings with enhanced adhesion and film density. Many cathodic arc deposition systems are actually in use in industry and research. They all work under (high) vacuum conditions in which water vapor pressure is an important source of film contamination, especially in the pulsed arc mode of operation. Here we present a cathodic arc system working under ultra-high vacuum conditions (UHVCA). We have used for arc ignition a Nd-YAG pulsed laser focused on the cathode surface, which provides a reliable system and allows eliminating all possible sources of contaminants. We have proven that the arc technique produces bulk-like films suitable for superconducting applications. UHVCA has been used to produce ultra-pure niobium films with excellent structural and electrical properties at a deposition temperature lower than 100 °C. The UHVCA technique therefore opens up new perspectives for all applications requiring pure films and low deposition temperatures.     

Organic Protective and Decorative Coatings for Metal Containers

The adhesion of paint to metal is affected by the nature and condition of the metal surface at least as much as by the nature of the paint. Paints of all types appear to adhere well to most very clean metals but the adhesion of some paints is sensitive to extremely low levels of contamination—for example, by stearic acid. Non-polar hydrocarbon contaminants do not reduce adhesion seriously unless they are present in amounts sufficient to weaken the cohesion of an interfacial layer. The surfaces of almost all commercial metal sheets are contaminated and require pretreatment before painting. The nature of the contaminants present are discussed and laboratory techniques for obtaining cleaning surfaces are reviewed.     

Analysis of failed nuclear plant components

Argonne National Laboratory has conducted analyses of failed components from nuclear power- gener-ating stations since 1974. The considerations involved in working with and analyzing radioactive compo-nents are reviewed here, and the decontamination of these components is discussed. Analyses of four failed components from nuclear plants are then described to illustrate the kinds of failures seen in serv-ice. The failures discussed are (1) intergranular stress- corrosion cracking of core spray injection piping in a boiling water reactor, (2) failure of canopy seal welds in adapter tube assemblies in the control rod drive head of a pressurized water reactor, (3) thermal fatigue of a recirculation pump shaft in a boiling water reactor, and (4) failure of pump seal wear rings by nickel leaching in a boiling water reactor. Work supported by Commonwealth Edison Company under ACK 85026.     

Transistor bonding wire corrosion in type TO cans

Wire- to- post bonds of silicon transistors in hermetic TO type packages are reliably corrosion resistant. A field failure rate of 0.21 ppm is attributed to random, uncontrolled contaminants acting in conjunction with excessive moisture. An exhaustive effort to replicate such failures employing high temperature and humidity in the absence of deliberately introduced contaminants was unsuccessful.     

脱除重油中有害金属杂质新技术

用化学药剂在一定条件下进行反应后用水萃取，并用 电脱水的方法脱除金属.研究了注药剂量、反应温度和反应时间等因素对脱除率的影响.     

Life extension of trivalent chromium passivation baths and enhanced product performance

Abstract

Although Cr (III) based passivation processes are mature, there is always pressure from end users to improve the performance of passivation films. The effect of incorporating ceramic nanoparticles into the film on the corrosion protection of steel components is reported for zinc coatings, with particular emphasis on cobalt-free processes. A novel technology based on selective ion-exchange to remove contaminants such as iron and copper as well as dissolved zinc from trivalent chromium baths is also described. Removal of these metals simultaneously without any appreciable reduction in chromium concentration rejuvenates the system and increases bath life significantly. This reduces not only the cost of frequent make-ups but also the load on the effluent treatment system, and imparts greater consistency to the life and appearance of the components processed. The concept can be extended to baths for chromating of aluminium and its alloys. Technical data generated from actual industrial installations are presented and discussed.