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EXPERIMENTAL STUDY AND MODELING OF PRESSURE LOSS FOR FOAM-CUTTINGS MIXTURE FLOW IN HORIZONTAL PIPE

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Journal of Hydrodynamics 2011年第4期23卷 431-438页

作者： AMNA Gumati HIROSHI Takahshi Graduate school of environmental studies Tohoku University

In this study, we first sought to elucidate foam rheology to describe foam flow behavior, and then to experimentally investigate the pressure losses for both foam and foam-cuttings flow in a horizontal pipe by considering both varied foam qualities of 80%, 85% and 90% and foam velocities. Also, a two-layer numerical model to predict pressure loss was developed based on experimental observations of cuttings behavior. Results show that the foam behaves like a power-law fluid. Furthermore, and the pressure loss significantly increases as foam velocity increases, while the delivered cuttings concentration dramatically decreases. Moreover, results indicate that both the pressure loss and the delivered cuttings concentration increase with foam quality. Comparisons between the experimental results and numerical model predictions show satisfactory agreement.

关键词： foam rheology pressure loss horizontal pipe cuttings concentration two-layer model

Interactions between Soil Characteristics, environmental Factors, and Plant Species Abundance: A Case Study in the Karst Mountains of Longhushan Nature Reserve, Southwest China

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Journal of Mountain Science 2015年第4期12卷 943-960页

作者： Dado TOURE GE ji-wen ZHOU Jian-wei Institute of Ecology and environmental Sciences School of Environmental Studies China University of Geosciences Faculty of environmental Geology School of Environmental Studies China University of Geosciences

The ability to manage and restore plant communities in the face of human-induced landscape change may rely on our ability to predict how species respond to environmental *** this response requires examining factors or their interactions that have influence on plant and resource *** objective was to analyze the relationships between changes in plant abundance and the interaction among environmental habitat factors including soil, geological(rock type), and other environmental variables in the Longhushan karst mountains *** density and dominance were examined using ANOVA, ANCOVA,and Generalized Linear Models to establish the single or combined effects of these groups of *** results showed that trends in abundance were mainly affected by rock type(related to the percentage content of dolomite and calcite), soil characteristics in association with *** plant indices were higher in dolomite dominated areas and varied positively with moisture, and elevation, but negatively with organic matter, while density also increased with slope *** results demonstrate that significant variations in species abundance was produced with the combination of variables from soil, geological, andenvironmental factors, suggesting their interaction influence on *** postulate that spatial variations in plant abundance in karst ecosystem depends on the carbonate rock type in addition to water and nutrient availability which are mainly controlled by topography and other factors such as soil texture and *** study suggests that in karst areas carbonate rock type, in addition to local environmental variables, should be taken into account when analyzing the factors that have impact on plant communities.

关键词： Interrelationship Karst soil Plant abundance Rock type Longhushan Nature Reserve

The Impact of Climate Change on Agriculture in Asia

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Journal of Integrative Agriculture 2014年第4期13卷 660-665页

作者： Robert Mendelsohn school of Forestry and environmental studies Yale University

Asian agriculture is responsible for two thirds of global agricultural GDP. There have been numerous studies exploring the impact of climate change on crops in specific locations in Asia but no study has yet analyzed crops across the entire continent. This study relies on a Ricardian study of China that estimated climate coefficients for Chinese crops. These coefficients are then used to interpolate potential climate damages across the continent. With carbon fertilization, the model predicts small aggregate effects with a 1.5℃ warming but damages of about USS84 billion with 3℃ warming. India is predicted to be especially vulnerable.

关键词： agriculture climate change Asia Rieardian

Hydrogeochemical and Isotopic Evidence for Flow Paths of Karst Waters Collected in the Heshang Cave,Central China

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Journal of Earth Science 2015年第1期26卷 149-156页

作者： Xiang Long Ziyong Sun Aiguo Zhou Deliang Liu school of environmental studies China University of Geosciences

Understanding of hydrological processes in caves is important to help us interpret paleoclimate records from speleothems. In this study, we integrated hydrogeological and hydrogeochemical properties to characterize the hydraulic behavior of karst waters in the Heshang Cave, Central China. Using geological and topographical analyses, we identified regional watershed boundaries and hydrogeological connections that were controlled by anticlinal geometry and faults. Water samples were collected from the Heshang Cave and potential recharge sites. Geochemical data of c（Sr^2＋）/c（Ca^2＋） and c（Mg^2＋）/c（Ca^2＋） ratios suggest that the drainage system in Heshang Cave consists of two flow paths. For vadose waters, including drip water and rimstone pool water, c（Sr^2＋）/c（Ca^2＋） ratio ranges from 0.000 6 to 0.001 1, and c（Mg^2＋）/c（Ca^2＋） ratio ranges from 0.97 to 1.1, indicating that recharge was mainly from rainfall infiltration through the overlying Cambrian dolomite stratum. In contrast, slope current and underground river waters have higher c（Sr^2＋）/c（Ca^2＋） ratios （values from 0.002 2 to 0.002 8）, and lower c（Mg2＋）/c（Ca^2＋） ratios （values from 0.50 to 0.64）. These waters show homogeneous isotopic composition （δ^18O： -7.15‰- -6.95‰; δD： -52.73‰- -51.31‰）, implying recharge of allogeneic water from the Xiaocr River via karst conduits that pass through Ordovician limestone and Cambrian dolomite stratum.

关键词： karst water hydrogeochemistry stable isotope flow path Heshang Cave.

Determination of Carbonate Minerals Responsible for Alkaline Mine Drainage at Xikuangshan Antimony Mine, China: Using Thermodynamic Chemical Equilibrium Model

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Journal of Earth Science 2015年第5期26卷 755-762页

作者： Tananga Mathews Nyirenda Jianwei Zhou Lina Xie Xizhe Pan Yi Li school of environmental studies China University of Geosciences

Minerals responsible for mine water quality at the Xikuangshan antimony mine were identified and characterized by a computer-assisted thermodynamic chemical equilibrium model. A total of 30 samples were collected and analyzed for major cations and anions. The Eh-pH diagrams identified Fe2O3 as the dominant iron species, while SO4^2- was the dominant sulfide species, which indicates acid production. The major acid producing minerals undergoing oxidation were identified to be pyrite, pyrrhotite, arsenopyrite and siderite. Other secondary sulfide minerals that contributed to SO4^2- concentration in the groundwater were gypsum and epsomite. Calcite and dolomite were the main buffering carbonate minerals. Identification of the specific acid producing and consuming minerals occurred in the mine area is critical to determine an effective water management plan.

关键词： hydrogeochemistry groundwater water-rock interactions acid buffering carbonates

Evaluation of nitrate source in groundwater of southern part of North China Plain based on multi-isotope

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Journal of Central South University 2015年第2期22卷 610-618页

作者：方晶晶周爱国马传明刘存富蔡鹤生甘义群刘运德 school of environmental studies & State Key Laboratory of Biogeology and environmental Geology China University of Geosciences

Nitrate pollution in groundwater is a serious water quality problem that increases the risk of developing various *** is the most important water resource and supports a population of 5 million in Anyang area of the southern part of the North China Plain. Determining the source of nitrate pollution is the challenge in hydrology area due to the complex processes of migration and transformation. A new method is presented to determine the source of nitrogen pollution by combining the composition characteristics of stable carbon isotope in dissolved organic carbon in groundwater. The source of groundwater nitrate is dominated by agricultural fertilizers, as well as manure and wastewater. Mineralization, nitrification and mixing processes occur in the groundwater recharge area, whereas the confined groundwater area is dominated by denitrification processes.

关键词： δ^12NNO3 δ^18ONO3 δ^13CDOC esophageal cancer groundwater

Statistical Verification of Hydraulic Units in a Heterogeneous Reservoir of the Liaohe Oilfield

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Journal of Earth Science 2014年第6期25卷 991-1002页

作者： Wei Zhou Shuxian Liang Desheng Ma Zhonghua Tang State Key Laboratory of Enhanced Oil Recovery Research Institute of Petroleum Exploration and Development school of environmental studies China University of Geosciences

The Liaohe Oil Field has passed peak production and correct discrimination of hydraulic units（HU） has vital significance for forecasting remaining oil distribution in a petroleum reservoir, enhancing the recovery ratio and adjusting development plans. A unified multi-parameter cluster analysis and fuzzy quality synthetic evaluations have been used for the identification of reservoir hydraulic units. This paper analyzes three predictions within Block Shen-95： intersection of multiple well-logs, independent mulitple well-logs and mutually exclusive multiple well-logs. HU has been delineated to conveniently compute permeability and serve as the basis of a structural model for enhanced simulation study. HU has been defined by the flow zone indicator concept using a modified Kozeny-Carmen equation. The Bayesian method was used to predict HU at uncored wells by constructing a probability database and then integrating established HU and well-log responses at cored wells. HU has then been inferred from the database using well-log responses. Estimated permeability from predicted HU gave an overall improved permeability match when compared with traditional statistical methods. The method proved most favourable when using mutually exclusive multiple well-logs, most significant by integrating reservoir performance with HU distribution and indicating that reasonable prediction had been obtained at uncored wells using this mutually exclusive approach. The distribution pattern was revealed by interwell HU correlation using modified depositional cycles as a framework, an integration step that qualitatively examines prediction accuracy. Detailed analysis has been carried out to determine and verify the characteristics of each kind of flow unit, providing a detailed geological basis for control of the oil field.

关键词： hydraulic unit Bayesian permeability reservoir performance Shen-95

Empirical Research on Carrying Capacity of Human Settlement System in Dalian City, Liaoning Province, China

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Chinese Geographical Science 2015年第2期25卷 237-249页

作者： ZHENG Defeng ZHANG Yu ZANG Zheng SUN Caizhi school of Urban Planning and environmental Science Liaoning Normal University Center for studies of Marine Economy and Sustainable development Liaoning Normal University

Using the theories of population carrying capacity and ecological elasticity in other fields for reference, the connotation of regional human settlement system was defined from the viewpoint of the complex relationship among the factors such as regional population, resources, environment and economic and social development in the context of China′s rapid urbanization. Then the concept and characterization methods of the regional human settlement carrying capacity were proposed by means of population scale. Furthermore, a model of carrying capacity-pressure-state-response(CPSR) on regional human settlement system was established by referencing pressure-state-response(PSR) model, and the Catastrophe Theory was introduced to determine the corresponding standards of multi-criteria programming and evaluation. Taking Dalian City, Liaoning Province, China as an example, an empirical analysis on evaluation of human settlement system from 2000 to 2012 was carried out. The results showed that the carrying capacity of human settlement system in Dalian was fluctuating between 9.6 × 106 to 10 × 106 persons with a quantitative stage of the dynamic regulation. During the research period the load index of human settlement system in Dalian dropped from 0.96 to 0.84 with a lower pressure of human settlement system than the national average level. And the emergency response grades of human settlement system in Dalian were kept in grade Ⅱ(orange warning) or grade Ⅲ(yellow warning). Human settlement system of Dalian was in slight security state as a whole, but the load had a tendency of increase in recent years. The related departments should pay close attention to regional human settlement system and take active measures to improve human settlement by both intensity control and total quantity control. By comparison, analysis and discussion, it was considered that the results were basically accordded with the current situations of human settlement in Dalian, and the evaluation results w

关键词： human settlement capacity-pressure-state-response(CPSR) model carrying capacity multi-objective decision making Dalian City China

Loess magnetic properties in the Ili Basin and their correlation with the Chinese Loess Plateau

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Science China Earth Sciences 2010年第3期53卷 419-431页

作者： NAOTO Ishikawa Graduate school of Human and environmental studies Kyoto University

Over the past two decades, magnetoclimatological studies of loess-paleosol sequences in the Chinese Loess Plateau (CLP) have made outstanding achievements, which greatly promote the understanding of East Asian paleomonsoon evolution, inland aridification of Asia, and past global climate changes. Loess magnetic properties of the CLP have been well studied. In contrast, loess magnetic properties from outside the CLP in China have not been fully understood. We have little knowledge about the magnetic properties of loess in the Ili Basin, an intermontane depression of the Tianshan (or Tien Shan) Mountains. Here, we present the results of rock magnetic measurements of the Ili loess including mass magnetic susceptibility (χ) and anhysteretic remanent magnetization (ARM), high/low temperature dependence of susceptibility (TDS) and hysteresis, as well as X-ray diffraction (XRD) for mineral analysis. Based on the comparison with loess-paleosol sequences in the CLP (hereafter referred to as the Chinese loess), we discuss the possible magnetic susceptibility enhancement mechanism of the Ili loess. The results show that 1) the total magnetic mineral concentration of the Ili loess is far lower than that of the Chinese loess, though they have similar magnetic mineral compositions. The ferrimagnetic minerals in the Ili loess are magnetite and maghemite, and the antiferromagnetic mineral is hematite; XRD analysis also identifies the presence of ilmenite. The ratio of maghemite is lower in the Ili loess than in the Chinese loess, but the ratios of magnetite and hematite are higher in the Ili loess than in the Chinese loess. 2) The granularity of magnetic minerals in the Ili loess, dominated by pseudo-single domain (PSD) and multi-domain (MD) grains, is generally much coarser than that of the Chinese loess. Ultrafine pedogenically-produced magnetic grains have a very limited contribution to the susceptibility enhancement. Rather, PSD and MD particles of magnetite and maghemite are th

关键词： loess magnetic property magnetic susceptibility the Ili Basin the Chinese Loess Plateau