Mathematical modeling of fluid flow and level profile during twin-roll strip casting process

In twin-roll strip casting process,transport phenomena of fluid in the molten pool directly affect the process stability and the quality of products.In order to elucidate the fundamental transport phenomena in twin-roll casting,a commercial software called ProCAST was employed to simulate the transient fluid flow and level profile behaviors during the early stage of the process in this study.The coupled set of governing differential equations for mass,momentum and energy balance were solved with the finite element method and the transient free surface problem was treated with a volume of fluids(VOF) approach.The effect of different delivery systems configuration on flow pattern,level profile in the pool was studied and analyzed in this paper. The new wedge metal delivery systems have been optimized for the twin-roll strip caster.It was shown that new type metal delivery systems had a preferable effect on the uniform distribution of fluid and level fluctuation in the pool.The simulation results also provide a valuable basis for the optimization of delivery system and process parameters during the initial pouring stage.

Effect of the Type of Vitis vinifera Cultivation in the Cenophenoresistome and Metabolic Profiling （CLPP） of Edaphic Bacterial Communities

In the present work, bacterial soil communities of different grapevine exploitation samples are studied in order to elucidate the possible influence of different agrarian management techniques （use of fertilizers, irrigation with river water） may have on the rhizospheric microbiome of Vitis vinifera plants. Therefore, it is postulated the Cenophenoresistome as a novel methodology to evaluate complex communities＇ global resistance against different antibiotics, by using and adjusting a serial of techniques traditionally applied to evaluate a monospecific population＇s resistance against antibiotics （Vitek, ATB and disk diffusion methods）. Likewise, the metabolic profile （CLPP： comunity level physiological profile） of bacterial communities is studied by Biolog ECO. In relation to the functional structure of the bacterial communities, it is observed that the metabolic profile （diversity, kinetics and CLPP） of unexploited soils differs from soils under anthropic influence. It is discussed the causes of resistance in the human clinic antibiotic treatment based on the agrarian management, especially with the contamination transmitted by irrigation water, which could be associated with changes in edaphic communities. The results obtained in the present study through two different approaches （Cenophenoresistome and metabolic profiles） are consistent with each other, suggesting that both methods can be good bioindicators of the state of humankind-altered soils that host natural ecosystems. Likewise, the concept of Cenophenoresistome is proposed as a bioindicator of soil response to alteration processes, as well as a possible predictor of its evolution in edaphic remediation processes.

THEORY AND PRACTICE ON DETERMINATION OF DEEP LEVEL PROFILES IN MULTIHIGH-DENSITY-LEVEL CASE

This work is an improvement of the theory proposed by Qin Guogang and C. T. Sah for determination of deep level profiles in the multi-level ease. The previous theory cannot be applied to the ease when a level whose density is comparable to the carrier density exists between the Fermi level and the deep level under study or when the deep level under study locates near the middle of the forbidden gap. The present work has overcome those restrictions so that it is applicable to more general cases. For the proton-implanted CZ-Si sample, the density profile of E(0.22), second acceptor level of divacancies, has been calculated in the presence of highly concentrated oxygen-vacancy level E(0.15) and has been compared with the profile of the same level E(0.22) calculated without considering the existence of E(0.15).

An Optimal Resource Provision Policy in Cloud Computing Based on Customer Profiles

Conventional resource provision algorithms focus on how to maximize resource utilization and meet a fixed constraint of response time which be written in service level agreement（SLA）.Unfortunately,the expected response time is highly variable and it is usually longer than the value of SLA.So,it leads to a poor resource utilization and unnecessary servers migration.We develop a framework for customer-driven dynamic resource allocation in cloud computing.Termed CDSMS（customer-driven service manage system）,and the framework’s contributions are twofold.First,it can reduce the total migration times by adjusting the value of parameters of response time dynamically according to customers’profiles.Second,it can choose a best resource provision algorithm automatically in different scenarios to improve resource utilization.Finally,we perform a serious experiment in a real cloud computing platform.Experimental results show that CDSMS provides a satisfactory solution for the prediction of expected response time and the interval period between two tasks and reduce the total resource usage cost.

Relationship Between Vegetation Restoration and Soil Microbial Characteristics in Degraded Karst Regions: A Case Study

The mechanism of vegetation restoration on degraded karst regions has been a research focus of soil science and ecology for the last decade.In an attempt to preferably interpret the soil microbiological characteristic variation associated with vegetation restoration and further to explore the role of soil microbiology in vegetation restoration mechanism of degraded karst regions,we measured microbial biomass C and basal respiration in soils during vegetation restoration in Zhenfeng County of southwestern Guizhou Province,China.The community level physiological profiles(CLPP) of the soil microbial community to were estimated determine if vegetation changes were accompanied by changes in functioning of soil microbial communities.The results showed that soil microbial biomass C and microbial quotient(microbial biomass C/organic C) tended to increase with vegetation restoration,being in the order arboreal community stage > shrubby community stage > herbaceous community stage > bare land stage.Similar trend was found in the change of basal respiration(BR).The metabolic quotient(the ratio of basal respiration to microbial biomass,qCO 2) decreased with vegetation restoration,and remained at a constantly low level in the arboreal community stage.Analyses of the CLPP data indicated that vegetation restoration tended to result in higher average well color development,substrate richness,and functional diversity.Average utilization of specific substrate guilds was highest in the arboreal community stage.Principle component analysis of the CLPP data further indicated that the arboreal community stage was distinctly different from the other three stages.In conclusion,vegetation restoration improved soil microbial biomass C,respiration,and utilization of carbon sources,and decreased qCO 2,thus creating better soil conditions,which in turn could promote the restoration of vegetation on degraded karst regions.