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991.
Remember when the management gurus told you your job was to build teamwork? Now the in-word is collaboration, because innovation of all kinds requires high levels of interactivity, not only within teams but also across traditional boundaries. That includes integrating technology with business solutions, developing convergent product offerings, slashing transaction costs, and responding to disasters. 相似文献
992.
E. Kh. Shakhpazov I. G. Rodionova O. N. Baklanova A. I. Zaitsev D. A. Burko A. D. Gorin S. D. Zinchenko 《Metallurgist》2006,50(1-2):65-70
It is shown that the corrosion resistance of automobile sheet can be improved by ensuring that steels of this type have a
low content of corrosion-active nonmetallic inclusions (CANI). The main mechanisms responsible for the formation of CANI in
automobile sheet have been established, and recommendations have been developed to reduce their concentration in this product
• optimize the deoxidation processes that are used by ensuring that the proportions of the additions made to the steel are
consistent with the composition of the ladle slag and that certain key temperature-time parameters of these processes are
maintained
• control the composition of the ladle slag to prevent the formation of solid phases in the slag and their transfer to the
metal; certain conditions must also be observed in the argon blow and the introduction of the addtions.
Use of the above recommendations to make automobile sheet and tube steels cleaner with respect to their content of CANI and
thus help optimize out-of-furnace treatments at metallurgical and pipe plants will make it possible to improve the corrosion
resistance of metal products used in automotive manufacturing.
__________
Translated from Metallurg, No. 2, pp. 45–48, February, 2006. 相似文献
993.
A simple one-dimensional model that can evaluate the transport and fate of nitrogen in wetland soil-vegetation systems was developed to calculate the nitrogen-removal efficiencies of reed-bed wetlands. A common wetland plant, Phragmites australis, was the focus of this study. Seasonal variations of temperature, seasonal changes of nitrogen uptake by vegetation, the vertical distribution of root biomasses and oxygen transport into the soil by vegetation were considered in the model. Field observations were conducted to determine some model parameters and to validate the model, although most of the parameters were adopted from data published in Europe and North America. Field observations were carried out at the Minuma-Tanbo wetland (35 degrees 52' N, 139 degrees 43' E) in Japan. The calculated concentrations of NH4-N in the soils were about 10 times larger than those of the observational results. On the other hand, calculated NO3-N concentrations were about half of the observational data. However, the calculated nitrogen-removal efficiencies indicated the same trends as previous studies. It was found that the hydraulic loading rate played a key role in relation to nitrogen removal and nitrogen transformation in reed wetland systems. 相似文献
994.
Fertilisers may contain pollutants that are applied to the field together with the nutrients. Comparing fertilisers is difficult because of their different concentrations of nutrients and pollutants. In this study an already existing model was taken. It was further developed to compare nutrient fluxes (N, P, K, Ca, Mg, S, humus) and pollutants (heavy metals and pharmaceuticals) of pig and cattle slurry as well as human urine. The data used is taken from literature and, in the case of pharmaceuticals in urine, daily excretion rates were calculated. An amount of 19 m3 ha(-1) a(-1) undiluted urine can be applied, limiting factor is sulphur. Without taking over-fertilisation into account, an addition of mineral fertiliser is required to any organic fertiliser application. In general, heavy metal, antibiotic, and hormone fluxes are higher by using animal manure then urine as fertiliser. However, additional loads of other pharmaceuticals consumed by humans have to be considered. Overall, the model is a suitable tool worthwhile to be extended in aspects of hygiene, environmental impacts as for example, degradation processes as well as ecotoxicology. 相似文献
995.
The San Diego County Water Authority of California has initiated planning for coastal desalination facilities to augment their water supplies. Integration of the different water qualities from these facilities into existing pipelines must be achieved. This investigation determined whether, and to what degree, consumers can discriminate between desalinated seawater and imported water supplies and how these investigations can contribute to decision making regarding the need for construction of facilities to blend such supplies prior to delivery. Based upon the results of the flavour profile analysis panel and the consumer evaluation sessions, it was concluded that free chlorine versus chloramine disinfection or different concentrations of disinfectants did not significantly affect consumer perception of the taste and odour of desalinated seawater or blends with Colorado River water and State project water. Consumers were able to discern between desalinated seawater and imported water, preferring imported water when forced to make a choice. However, the investigators did not believe that the difference in consumer perception was significant enough to warrant special blending facilities to mitigate the relatively minor aesthetic quality differences between imported water supplies and desalinated seawater. 相似文献
996.
997.
Poor sanitation and insufficient disposal of sewage and faeces are primarily responsible for water associated health problems in developing countries. Domestic sewage and faeces are prevalently discharged into surface waters which are used by the inhabitants as a source for drinking water. This paper presents a decentralized anaerobic process technique for handling of such domestic organic waste. Such an efficient and compact system for treating faeces and food waste may be of great benefit for developing countries. Besides a stable biogas production for energy generation, the reduction of bacterial pathogens is of particular importance. In our research we investigated the removal capacity of the reactor concerning pathogens, which has been operated under thermophilic conditions. Faecal coliforms and intestinal enterococci have been detected as indicator organisms for bacterial pathogens. By the multiple regression analysis technique an empirical mathematical model has been developed. The model shows a high correlation between removal efficiency and both, hydraulic retention time (HRT) and temperature. By this model an optimized HRT for defined bacterial pathogens effluent standards can be easily calculated. Thus, hygiene potential can be evaluated along with economic aspects. In this paper not only results for describing the hygiene potential of a thermophilic anaerobic bioreactor are presented, but also an exemplary method to draw the right conclusions out of biological tests with the aid of mathematical tools. 相似文献
998.
G. L. Brownell C. A. Burnham C. W. Stearns D. A. Chesler A.-L. Brownell M. R. Palmer 《International journal of imaging systems and technology》1989,1(2):207-217
The development of high resolution PET systems is important for the wider application of this techniques. The resolution of PET is limited by a number of physical factors such as positron range, small angle deviation, and sampling frequency. The design of the detector array and its sensitivity remain critical factors; designs incorporating analog coding have proven to be useful. PCR-I, a single plane PET system, has demonstrated the concept and has produced useful images in animal studies. PCR-II will extend the concept to a two dimensional detector array resulting in a system with high resolution and high sensitivity. 相似文献
999.
Mixed-mode fracture of composites using Iosipescu shear test 总被引:1,自引:0,他引:1
Finite element analysis is used to determine the influence of elastic properties on the stress distribution in the Iosipescu shear test specimen. Two different boundary conditions are used which assume either the application of force couples or specified displacements. The effect of orthotropy ratio is investigated with E
11/E
22ranging from 1 to 14.2. The analysis is extended to partially cracked specimens and used to calculate the basic fracture parameters in aligned composite materials. In particular, the failure of specimens with two axial splits, nucleated at the roots of the notches, and extended in the fibre direction is analysed. It is shown that the stress distribution is strongly dependent on both the elastic properties and boundary conditions. The mixed mode stress intensity factors K
Iand K
IIat the crack tips tend to increase with orthotropy ratio. The analysis is discussed with respect to the limited experimental data available for this test geometry. From the numerical and experimental results the mixed mode toughness is estimated in terms of the critical stress intensity factors and the critical energy release rate.Résumé On recourt à une analyse par éléments finis pour déterminer l'influence des propriétés élastiques du matériau sur la distribution des contraintes dans l'éprouvette de l'essai de cisaillement de Iosipescu. Deux conditions aux limites sont considérées: l'application de couples de forces ou de déplacements imposés. L'effet du rapport d'orthotropie est étudié, pour des valeurs de E
11/E
22comprises entre 1 et 14,2. L'analyse est étendue au cas d'éprouvettes partiellement fissurées, et est utilisée pour le calcul des paramètres fondamentaux de rupture dans des matériaux composites à fibres alignées. On analyse en particulier la rupture d'éprouvette comportant deux séparations axiales, prenant naissance aux racines ds entailles et s'étendant dans la direction de la fibrosité.On montre que la distribution des containtes dépend fortement des propriétés élastiques du matériaux et des conditions aux limites. Les facteurs d'intensité de contrainte correspondant au mode mixte K
Iet K
IIde rupture aux extrémités de la fissure tendant à croître avec le rapport d'orthotropie.Une discussion sur cette analyse tient compte du nombre limité de données expérimentales disponibles pour cette géométrie d'éprouvettes. On peut estimer la ténacité sous mode mixte à partir des résultats numériques et expérimentaux, et l'exprimer par les facteurs critiques d'intensité de contraintes et la vitesse critique de relaxation de l'énergie. 相似文献
1000.
N. F. Kuschevskaya A. E. Kushchevskii A. I. Oleshko 《Powder Metallurgy and Metal Ceramics》2006,45(3-4):202-206
The possibility of utilizing nanopowders of iron and Fe-Co-Ni produced bu a thermochemical method in the fabrication of sealing
composition materials is investigated. It is established that such hermetic sealing composition materials function reliably
under extremal conditions and guarantee elevated strength of adhesion to the surface of the metal and high corrosion and temperature
stability.
__________
Translated from Poroshkaya Metallurgiya, Nos. 3–4(448), pp. 112–117, March–April, 2006. 相似文献