Papers by Keyword: Migration

Abstract: According to the basic principles of electromagnetism, the magnetic flux density on the surface of the metal melt was calculated by numerical simulation method. The relational expression of the electromagnetic body force and the magnetic flux density was deduced. The results show that the electromagnetic body force in the melt is directly proportional to the square of the magnetic induction intensity. Increasing the electric current, the electromagnetic body force in the melt can be increased effectively. Increasing the frequency, the particular electromagnetic body force within the melt can be increased first and then decreased.

Abstract: Along with the widespread use of food wrap paper, it is very important to discuss the migration of lead in paper. The migration of lead from six kinds of food wrap papers under different temperatures (5 °C, 25°C, 35°C, 60°C and 85°C) were investigated by using water as an imitation in this paper. It was found that the initial migration rate was affected by the sizing degree of paper, but the final migration ratio was mainly decided by initial concentration of lead in paper, and the migration rate increased with the increasing of temperature.

Abstract: The organic contaminants which in the printing inks or varnish of paper (board) surface can migrate via paper (board) to the packed food (simulants) in the form of gases and do harm to the health of consumers.To predict the concentration of them in the packed food (simulants) at a given storage time, the migration model of them was established. For a sheet of paper consists of several layers of interlaced fibers, the organic contaminants can be traped by the fibers when they penetrate to the inner layers by the capillaries in the printing process, so the linear coefficient of retardation R_m was introduced to modify the Fick’s Laws, and the diffusion equationwas gotten. It demonstrated that the values of R_m increase with the increasing of molecular weight of surrogates, and decrease with the increasing of migration temperature. And the diffusion coefficients D_p of phenol, 2, 6-Dissopropyl naphthalenes (2,6-DIPNs) and dibuthyl phthalate (DBP) in the kraft paper board were range from 10^-5 to 10^-4 at 75°C and 100°C. Then the migration model was validated by migration experimental tests, and the model described the profile of the experimental values very well.

Abstract: Oil-gas migration is an important process of the reservoir formation. Based on this discussion, a numerical simulation was conducted to study on oil-gas migration and aggregation. With considering the flow behavior of gas-liquid two-phase flow, based on Navier-Stocks equations and the Darcy’s law, the movement characteristics of natural gas within the typical fault passage are predicted by using the finite volume method and pressure-velocity coupled algorithm. The velocity distribution of natural gas is discussed under the primary migration condition, as well as the diffusion concentration at different locations. Moreover, the position of spill points affecting natural gas aggregation is analyzed, which provides a theoretical basis for predicting reservoir formation and transport processes.

Abstract: In cloud computing, we have requested and used many resources from cloud vendors. Even though, hypervisor is a controller between hardware level applications and user application, Hypervisor will not provide the security for running huge user applications on guest platforms. As a customer perspective cloud is the domain which will offer numerous resources. But in cloud, when the users are running various process/applications on guest OS hypervisor will give the controlling notes or components, system configure and adaptation tools only. However, hypervisor will not have a focal point about security and need to be concerned about the possible factors for an applications which are consecutively perform on the guest OS . It doesn’t care about the end users security facts. This paper proposes an efficient security mechanism for hypervisor control to be developed / performed to improve the security aspects while application is running on virtual machine.

Abstract: The article presents the results of the research work on the peculiarities of recultivation of the ash dumps of power station No1 (PS1) in the city of Khabarovsk. The research showed that the climatic conditions of the region promote the dust dispersal of toxic agents from the surface of the ash dump. The pollution of the air basin here can be attributed to the extremely high level of pollution (EHP), the priority pollutant is the dust containing heightened concentrations of heavy metals (Pb, Mn, Cu, Cr, Co, Ni, Cd). As a result it leads to the deterioration of the population’s health, especially to the high level of respiratory organs diseases. The research of the sprouting of the herbaceous plants (mixture of timothy-grass, clover and mustard) on prepared model soils showed their healthy growth. The ash chemical composition was studied. It showed high concentration of toxic chemical elements (Hg, Be, Sr, Cd, V, Th, 40K, Cr, Mb, AS, Sb,Se, Te, Pb, Ni, Co). The migration intensity of heavy metals ions into the plants was analyzed. On the basis of the experimental research the optimum composition of the substrate was revealed and recommended for recultivating the ash dump of PS1, namely: soil+sand+ash. Climatic conditions of the Khabarovsk Krai do not permit to recommend the sand+ash substrate for recultivation because of strong winds.

Abstract: Measure content of fresh tailing sand in a certain skarn type copper mine selection tailing sand warehouse, lead, cadmium, arsenic, nickel and zinc elements, etc in old tailing sand by ICP-AES. Carry out eluviations test of tailing sand and leaching test of tailing sand by horizontal vibration method and Sulphuric-Nitric acid method respectively. Discuss with phase constitution of harmful elements such as arsenic in tailing sand by XRD analysis chromatogram of tailing sand. Compare with content analysis result and mineral constitution of related elements in raw mine on the basis. Research migration and distribution disciplines of associated harmful elements in raw mine to tailing sand by floatation. Test result shows that arsenic, zinc, cadmium and lead elements in raw mine deeply concentrated in tailing sand after mine selection. Percentage is 96.89%, 92.0%, 91.65% and 41.12% respectively. Main existence form of As in tailing sand is FeAsS (arsenopyrite). It intergrowth with pyrite (FeS₂); Zn mainly exists in a ZnS (sphalerite) form. Pb, Cd and As have migration trend from upstream to downstream of tailing sand warehouse and from shallow layer to deep layer. Dissolution rate of Cd, Cu, Zn, Cr and Pb under eluviation and weak acid leaching conditions is lower. However, they have release trend under acid conditions. Arsenic element is special as follows: It is undetected in various points during Sulphuric-Nitric digestion. However, tiny detection of fresh surface layer and deposit layer out of old tailing sand by horizontal vibration method prompts stability of arsenic tailing sand FeAsS and alarm of leaching activity under alkaline conditions. Cause of arsenic tailing sand FeAsS is that it is brought by raw mine without large destruction to FeAsS during mine selection process.

Abstract: Moisture has a detrimental effect on oil-paper insulation life by lowering electrical breakdown strength. How does the space charge behavior of the oil-paper insulation system consisted by oil gap and oil immersed insulation pressboard with different moisture content The space charge characteristics of the mixed insulation consisted of oil gap and pressboard with three moisture content were investigated using the PEA measurement system. The space charge accumulation behaviors at the interface between oil gap and pressboard were analyzed. The distortion of the electrical field in the oil gap and pressboard was also analyzed. Results show that there are many charges injected into the oil and the pressboard. The charges accumulated at the interface between oil gap and pressboard. The charges accumulated in the mixed insulation system become less with the moisture content increased. The difference of the electric field strength in the oil gap and pressboard become smaller with the moisture content increased.

Abstract: The risk of di (2-ethylhexyl) phthalate (DEHP) migration from plasticized poly (vinyl chloride) (PVC) is an important issue for patients.We present a study on the effect of gamma radiation on the migration of DEHP from plasticized PVC into air and PVC as a function of time (0-28day) at 75°C.The samples were irradiated at dose of 25 kGy using a ⁶⁰Co gamma radiation source.The change of weight loss at 75°C was studied as a function of time.Diffusion coefficient of samples was calculated,it was found that the diffusion coefficient significant increased after irradiation,the sample having ESO exhibited an decrease trend of DEHP migration,which shown that ESO can effectively impress the migration of DEHP from plasticized PVC either in control or irradiate samples,the same Phenomenon was found in air and PVC.The diffusion coefficient was between 8.37×10^-11 and 2.68×10^-10 cm²/s in air, 8.87×10^-8 and 9.99×10^-8 cm²/s in PVC.

Abstract: Nitrate salt is important heat transfer and storage medium in solar thermal power system, but nitrate salt leakage and pollution in groundwater is seldom investigated. In this paper, the nitrate salt leakage and migration in the soil after rainfall are simulated and analyzed. During the nitrate leakage process, the liquid nitrate will solidify, and then a thin solidification layer of nitrate forms. According to the simulation result, the radius of the leakage opening mainly affects the radius of nitrate solidification layer, while the leakage velocity will influence the radius and thickness of salt layer. During the nitrate migration process after rainfall, the nitrate will gradually migrate to the groundwater, and the final migration domain of nitrate in the soil will be mainly determined by the radius of nitrate solidification layer.