bluuebunny/crossref_metadata_2025 huggingface dataset:
Sources of Cretaceous Bimodal Volcanic Rocks in the Coastal Region of Southeastern China: — Constraints of the Sr content and its isotopes
Authors: Guangfu XING , Zhuliang YANG , Kuiyuan TAO
Published: October 2010

Abstract Cretaceous volcanism in the coastal region of southeastern China was characteristized by occurrence of bimodal volcanics consisting of basalts and rhyolites, the geneses of which are still controversial. Based on the fact that their isotopic compositions are similar but the Sr content of the former is much higher than that of the latter, this paper discusses the respective sources of the two end‐member rocks, and concludes that basalts were derived from the subduction‐related enriched upper mantle wedge and their isotopic compositions had not been affected by crustal assimilation, whereas rhyolites were formed by remelting of the old metamorphic basement, but they were mixed up with the underplating basaltic magmas to various degrees so that their Sr isotopic compositions varied significantly from the sources and tended to be homogeneous to the latter.
Multistage Extension and Age Dating of the Xiaoqinling Metamorphic Core Complex, Central China
Authors: Jinjiang ZHANG , Yadong ZHENG
Published: October 2010

Abstract There are two extensional systems in the Xiaoqinling metamorphic core complex (XMCC). One is the detachment fault system developed along the peripheries of the XMCC, which extended in an ESE‐WNW direction and whose upper plate moved towards the WNW. The other extensional system includes the retrograde shear zones and normal faults developed within the XMCC, which represent the collapse of the XMCC. Ar‐Ar and K‐Ar dating shows that the extension of the detachment fault system continued from 135 to 123 Ma, i.e. in the late stage of its evolution at about 127 Ma. The collapse represented by the extensional system within the XMCC was operative during 120–106 Ma, and its main activity occurred about 116 Ma ago. These suggest that the XMCC experienced two extensional stages in its evolution, i.e., the syn‐orogenic regional extension and post‐orogenic collapse extension.
A Large‐Scale Palaeozoic Dextral Ductile Strike‐Slip Zone: the Aqqikkudug‐Weiya Zone along the Northern Margin of the Central Tianshan Belt, Xinjiang, NW China
Authors: Liangshu SHU , Jacques CHARVET , Lingzhi GUO , Huafu LU , Sebastien LAURENT‐CHARVET
Published: October 2010

Abstract The nearly E‐W‐trending Aqqikkudug‐Weiya zone, more than 1000 km long and about 30 km wide, is an important segment in the Central Asian tectonic framework. It is distributed along the northern margin of the Central Tianshan belt in Xinjiang, NW China and is composed of mylonitized Early Palaeozoic greywacke, volcanic rocks, ophiolitic blocks as a mélange complex, HP/LT‐type bleuschist blocks and mylonitized Neoproterozoic schist, gneiss and orthogneiss. Nearly vertical mylonitic foliation and sub‐horizontal stretching lineation define its strike‐slip feature; various kinematic indicators, such as asymmetric folds, non‐coaxial asymmetric macro‐ to micro‐structures and C‐axis fabrics of quartz grains of mylonites, suggest that it is a dextral strike‐slip ductile shear zone oriented in a nearly E‐W direction characterized by “flower” strusture with thrusting or extruding across the zone toward the two sides and upright folds with gently plunging hinges. The Aqqikkudug‐Weiya zone experienced at least two stages of ductile shear tectonic evolution: Early Palaeozoic north vergent thrusting ductile shear and Late Carboniferous‐Early Permian strike‐slip deformation. The strike‐slip ductile shear likely took place during Late Palaeozoic time, dated at 269±5 Ma by the40Ar/39Ar analysis on neo‐muscovites. The strike‐slip deformation was followed by the Hercynian violent S‐type granitic magmatism. Geodynamical analysis suggests that the large‐scale dextral strike‐slip ductile shearing is likely the result of intracontinental adjustment deformation after the collision of the Siberian continental plate towards the northern margin of the Tarim continental plate during the Late Carboniferous. The Himalayan tectonism locally deformed the zone, marked by final uplift, brittle layer‐slip and step‐type thrust faults, transcurrent faults and E‐W‐elongated Mesozoic‐Cenozoic basins.
Dynamic Analysis of Deformational Structures of the Xiannüshan Fault Zone in the Three Gorges of the Yangtze River
Authors: Shuren WU , Ganguo WU
Published: October 2010

Abstract Field investigation and laboratory work reveal that inhomogeneity of the deformation of the Xiannüshan fault is mainly characterized by lateral zonation, longitudinal segmentation and downward stratification. Based on these results, a 3‐D deformational structure model of the fault was established and its geometrical and kinematic characteristics in two main deformational stages i.e. the main Yanshanian and Himalayan were discussed. The directions of principal and the differential stresses in these two stages were determined by using conjugate joints, striations of fault planes and microstructures of the fault zone. The direction of s̀1 is N‐S in direction with differential stresses of 150–250 MPa in the Yanshanian, and N70E with a differential stress ranging from 80–120 MPa in the Himalayan.
Deep Tectonic Processes and Superaccumulation of Metals Related to Granitoids in the Nanling Metallogenic Province, China
Authors: Rongfu PEI , Ping'an WANG , Cong PENG
Published: October 2010

Abstract The Nanling region is an important nonferrous and rare metal metallogenic province in South China, in which most of the deposits are related to granitoids in genesis. It covers southern Hunan, southern Jiangxi, Guangxi, Guangdong and Fujian provinces, with a total area of about 550,000 km2. This metallogenic province is well known in the world for its rich tungsten and tin resources. In the past 40‐odd years, a vast amount of mineral exploration activities and studies of the geology of mineral deposits have been carried out and great achievements obtained in the province. This paper is focused on a discussion about the deep tectonic processes in the orogenic belt during the Mesozoic and their contribution to the superaccumulation of metals. Tectonically, this metallogenic province is composed of three units: (1) the marginal continental orogenic belt in the Southeastern Coast fold system in the Yanshanian; (2) the intercontinental orogenic belt in the collision suture belt between the Yangtze and Cathaysian plates mainly in the Caledonian; and (3) the intracontinental orogenic belt induced by subduction of the ocean crust and delimination of the mantle lithosphere in the Yanshanian. It is suggested that superaccumulation of metals in this metallogenic province was caused by the existence of mantle rooted tectonics at the depth based on comprehensive studies of geophysical information of seismic, geothermal and magnetotelluric surveys in Nanling and its adjacent areas. The Xihuashan wolframite quartz vein deposit, the Shizhuyuan W, Sn, Mo, Bi greisen‐skarn deposit and the Dachang tin‐polymetallic deposit are three typical examples of the deep tectonic processes. However, this kind of deep tectonic processes only act as the “engine” of the superaccumulation of metals, which means that they should have to correspond with the super‐crust ore‐controlling pattern of “lines‐rows‐clusters” (L‐R‐C). This recognization is expected to play an important role in assessment of mineral resources in this province.
40Ar/39Ar Thermochronological Constraints on the Timing of Collisional Orogeny in the Mian‐Lüe Collision Belt, Southern Qinling Mountains
Authors: Jinyi LI , Zongqi WANG , Min ZHAO
Published: October 2010

Abstract Silurian, Devonian and Carboniferous geological bodies in the Mianxian‐Lüeyang (Mian‐Lüe) collisional belt (MLB) and its neighbouring areas, southern Qinling Mountains, China, show similar characteristics of having undergone deformation of two stages. The earlier one, which is inferred to be related to collisional orogeny between the Yangtze and Sino‐Korean palaeocontinents based on previous geological data, is responsible for large‐scale, north‐verging recumbent folds and overthrusts, and associated with low greenschist facies metamorphism. 40Ar/39Ar dating of three muscovite samples taken from different localities yields plateau ages of 226.9±0.9 and 219.5±1.4 Ma and an apparent age of 194.5±3.0 Ma. Thus, the late Triassic collision between the Yangtze and Sino‐Korean palaeocontinents has been constrained.
Sedimentary Features and Sea‐Level Changes Reflected in Drill Holes in the Zhuhai Area
Authors: Junren CHEN , Ling WAN
Published: October 2010

Abstract Experimental examinations and analyses have been made of the sediments from drill holes in the Zhuhai area, Guangdong Province. The studies show that there occurred four transgressions in this area over the historical times. The first transgression occurred at 7500 a B.P., with the maxium sea level up to about 1 m above the present level. The second transgression occurred at 5750 a B.P., with the sea level possibly 4 m higher than the present. The third and fourth transgressions took place at 4650 a B.P. and 2600 a B.P. respectively, which lasted for a long time with multiple fluctuations. The fifth transgression is in process. It could be predicted that the sea level at Zhuhai would rise by 15–20 cm in the coming 50 years.
Geochemical Characteristics of Gases from the Wudalianchi Volcanic Area, Northeastern China
Authors: Jianguo DU , Shengqiang LI , Yi ZHAO , Jinzhang REN , Rubo SUN , Heshun DUANMU
Published: October 2010

Abstract The origins of gases in springs, pools and wells from the Wudalianchi (WDLC) volcanic area are discussed based upon molecular and isotope compositions of the gases. Nine gas and water samples were collected from bubbles and water of the springs and pools in the WDLC volcanic area, Northeastern China, in August 1997. The molecular components were measured with a MAT‐271 mass spectrometer (MS), helium isotope ratios with a VG‐5400 MS, and δ13C with a MAT‐251 MS in the Lanzhou Institute of Geology. The gases are enriched in CO2, and most of the CO2 concentrations are over 80% (V). The helium and methane concentrations have relatively wide ranges of 0.7 to 380×10−6 and 4 to 180×10−6, respectively. The 3He/4He ratios are between 1.05 Ra and 3.1 Ra (Ra = 1.4×10−6); the 4He/20Ne values are between 0.45 and 1011, larger than the atmospheric value (0.32). The δ13C (PDB) values of carbon dioxide range from −9.6 to −4.2%%. These geochemical data demonstrate that the spring water is from aquifers at different depths, and that helium and carbon dioxide are derived from the mantle, and are contaminated by crust gases during deep fluid migration. Also, there are larger fluxes of deep‐earth matter and energy in the WDLC volcanic area.
Temporo‐Spatial Distribution and Evolution of Ore Deposits in the West Sector of the Northern Qilian Mountains
Authors: Jingwen MAO , Xiaoyu ZHANG , Zhaochong ZHANG , Fengshou REN , Guochao ZUO , Zuoheng ZHANG , Jianmin YANG , Zhiliang WANG , Dejin YE
Published: October 2010

Abstract The west sector of the northern Qilian Mountains is well‐known for the Jingtieshan‐type iron deposits. A new breakthrough has been made in prospecting for gold and copper in recent years. In this paper, the distribution characteristics of ore deposits in the study area are discussed from the viewpoint of tectonic evolution. It is suggested that there are 9 stages of mineralization from the Palaeoproterozoic to Indosinian. Four minerogenetic series and two minerogenetic subseries of ore deposits are recognized. Iron mineralization occurred in several stages, while most of the metals were accumulated in large amounts in the Caledonian. The enrichment and mineralization of gold is related to large‐scale shear‐strike‐slip faults and the ascent and unloading of deep‐seated fluids.
Late Quaternary Calcareous Nannofossils from the Offshore Sediments in southern Hongkong
Authors: Yongyang HUANG , Fang CHEN
Published: October 2010

Abstract Based upon the features of nannofossil composition, distribution, abundance and diversity, the fossil‐bearing sediments exposed by five drill holes in the offshore area of southern Hongkong can be divided into the upper Middle Pleistocene, the Upper Pleistocene and Holocene. There were two palaeoclimatic stages in the Holocene in this area according to fossil palaeoecologic and sedimentation analyses: the temperature‐rising stage and the warm stage. The latter involves two temperature‐falling periods, which could be the major factor causing sea‐level fall during that time.
Massive Sulphide Deposits Related to the Volcano‐Passive Continental Margin in the Altay Region
Authors: Jingbin WANG , Jiniu DENG , Jinhong ZHANG , Kezhang QIN
Published: October 2010

The Devonian volcano‐passive continental margin in southern Altay is a significant volcanogenic massive sulphide metallogenic belt. Acidic volcanism has been dominant on the inner side of the volcano‐passive continental margin, i.e., near the old land, resulting in a Pb‐Zn metallogenic sub‐belt, in which the ore deposits are hosted by sedimentary rocks in volcanic series, as represented by the large Koktal Pb‐Zn deposits. In the central part of the margin far away from the old land, bimodal volcanic formations are well developed, forming volcanics‐hosted Cu‐Zn metallogenic sub‐belts, e.g., the large‐scale Ashele Cu‐Zn deposit. The Qiaoxiahala sub‐belt on the outer side of the margin near the ocean ridge is located at the spreading central trough, where ophiolite suites are developed. This type of deposits is rich in gold and copper, similar to the Cyprus‐type Fe‐Cu‐Au metallogenic sub‐belt in metallogenic environment (represented by the Qiaoxiahala medium‐scale Fe‐Cu‐Au deposit). From the old land to the ocean, the mineralizing age becomes younger, i.e., from Early Devonian→Early and Middle Devonian→Middle Devonian, forming a complete metallogenic zoning series on the volcano‐passive continental margin. Comparative studies show that the massive sulphide deposits distributed on the volcano‐passive continental margin are different from those formed under a plate subduction regime and oceanic ridge environment; the former have their unique features and wide distributions, representing a new type of volcanogenic massive sulphide deposits—the Altay type.
Process of Rifting and Collision along Plate Margins of the Qinling Orogenic Belt and Its Geodynamics
Authors: Shaofeng LIU , Guowei ZHANG
Published: October 2010

The Qinling orogenic belt underwent complicated processes of rifting and collision, as shown by the coexistence of 1 ocean extension and plate margin rifting and 2 subduction of the frontal oceanic crust and extension of the rear plate margin. These resulted in a basin‐mountain framework characterized by the coexistence of plates separated by the ocean basin and continental blocks demarcated by the rifting sea trough in the marginal region and the coexistence of subduction orogeny and ocean extension. Generally speaking, the plate marginal area between the North China plate and Yangtze plate continually rifted from north to south and the rifted micro‐plates continually accreted northwards. This especial orogenic process was probably controlled by two events of deep mantle geodynamic adjustment and mantle plume activities, which occurred in the Shangdan suture belt and Mianlüe suture belt from north to south respectively.
Pre‐collision Granites and Post‐collision Intrusive Assemblage of the Kelameili‐Harlik Orogenic Belt
Authors: Lianxing GU , Shouxi HU , Qiang CHU , Chunshui YU , Xinjian XIAO
Published: October 2010

The main types of intrusive rocks in the Kelameili‐Harlik Hercynian orogenic belt include calc‐alkaline granites, diabase dykes, kaligranites and alkaline granites. Investigation in field geology, petrology, mineralogy and geochemistry shows that the calc‐alkaline granites belong to the syntexis‐type (or I‐type) and were formed in a pre‐collisional magmatic arc environment. In consideration of the fact that kaligranites have many features of alkaline granites with higher consolidation temperatures than the calc‐alkaline granites and show a discontinuity of minor element and REE evolution in respect to the calc‐alkaline granites, they could not have been derived by differentiation of magmas for the calc‐alkaline granites, but are likely to have been generated in an environment analogous to that for alkaline granites. The triplet of basic dyke swarms, kaligranites and alkaline granites could be regarded as a prominent indication of the initial stage of post‐collisional delamination and extension. These rocks might have originated from underplating and intraplating of mantle‐derived magmas at varying levels with varying degrees of partial melting, mixing, and interchange of crustal and mantle materials
Carboniferous Mixed Terrigenous Clastic, Carbonate and Sulphate Sediments in the Bachu Area, Xinjiang
Authors: Chuantao XIAO , Yuntang PAN
Published: October 2010

The Carboniferous system in the Xiaohaizi area, Bachu County, Xinjiang Uygur Autonomous Region, composed of typical mixed terrigenous clastic, carbonate and sulphate sediments, was mainly deposited in the tidal flat and lagoon environments. The mixed sediments occur as the following eleven types: 1. limestone intercalated with siltstone; 2. interbeds of shale and limestone; 3. gypsolyte interbedded with limestone; 4. gypsolyte intercalated with siltstone; 5. gypsolyte interbedded with shale; 6. gypsolyte intercalated with siltstone, limestone and dolomite; 7. siltstone interbedded with gypsolyte and limestone; 8. terrigenous detritus scattered in carbonate matrix; 9. carbonate as cement in clastic rocks; 10. mixed sediments of carbonate and terrigenous mud; 11. mixed sediments of carbonate grains with terrigenous sand. Based on the analysis of the dynamic mechanism of mixed sediments, it is believed that these types of mixed sediments in the study area were controlled by climate, sea level change and sources of sediments.
Features of the Early Palaeozoic Mantle beneath Langao County and Its Formation Mechanism
Authors: Xueyi XU , Yuehua HUANG , Linqi XIA , Zuchun XIA
Published: October 2010

Phlogopite‐amphibole pyroxenite xenoliths contained in an Early Palaeozoic alkali subvolcanic lamprophyre complex in Langao County, Shaanxi Province, are metasomatized mantle xenoliths, composed mainly of clinopyroxene, amphibole, phlogopite, apatite, pervoskite, ilmenite and sphene with well‐developed subsolidus metamorphism‐deformation textures, such as “triple points” and “cataclastic boundaries”. Minerological studies indicate that clinopyroxene is rich in SiO2 and MgO and poor in TiO2 and Al2O3, which is notably different from magmatogenic deep‐seated megacrysts and phenocrysts formed in the range of mantle pressure. Amphibole and phlogopite have the compositional feature of mantle‐derived amphibole and phlogopite. Sm‐Nd isotope studies suggest that the metasomatized mantle beneath Langao County is the product of metasomatism of primitive mantle by melt (fluid) derived from the mantle plume, and the mantle metasomatism occurred 650 Ma ago. The process of mantle metasomatism changed from mantle metasomatism induced by CO2‐, H2O‐ and CH4‐rich fluid in the early stage to that induced by melt and P‐, Ti‐, Ca‐ and Fe‐rich fluid in the late stage.
Low Pathogenic Avian Influenza (H7N1) Transmission Between Wild Ducks and Domestic Ducks
Authors: Therkildsen O. R. , Jensen T. H. , Handberg K. J. , Bragstad K. , Jørgensen P. H.
Published: October 2010

This article describes a virological investigation in a mixed flock of ducks and geese following detection of avian influenza virus antibodies in domestic geese. Low pathogenic H7N1 was found in both domestic and wild birds, indicating that transmission of virus was likely to have taken place between these. The importance of implementing and maintaining appropriate biosecurity measures is re‐emphasized.
Taxation and State Building: Towards a Governance Focused Tax Reform Agenda
Authors: Prichard Wilson
Published: October 2010

Taxation is fundamental to sustainable development, as it supports the basic functions of an effective state and sets the context for economic growth. More often overlooked is the role of taxation as a catalyst for the development of responsive and accountable government, and for the expansion of state capacity. Recent research has begun to focus on this broader relationship between taxation and state building, but the analysis has frequently remained relatively theoretical and abstract. This paper seeks to chart new territory by translating the findings of existing research into a practical agenda for action, focusing on the specific measures that governments, with the support of development partners, could be taking to strengthen the state building role of taxation. In short, this paper seeks to outline the core elements of a governance focused tax reform agenda.
The Effect of the Marangoni Flow on the Film Condensation
Authors: Peng Baohong , Yang Li , Wen Juan
Published: October 2010

The objective of this paper is to quantify the effect of Marangoni flow on the vapor film condensation and analyzed the effect of the gravity, the shearing force at the gas-liquid interface and the Marangoni strength caused by the surface tension on the Nusselt number. The results show that the effect of the gravity is very clear to the thickness of the film. Marangoni effect can not be ignored at zero gravity condition. The effect of the vapor Reynolds number (Rev0) at the zero-gravity conditions on the film is bigger than that at the gravity conditions. The average ratio of the film thickness (δ¯) is 6.5% at the gravity conditions and 21.5% at zero-gravity conditions when the Rev0 changes from 8000 to 15000.
Bubble Dynamics During Boiling in Polydimethylsiloxane (PDMS) Microchannels With Wire Heater
Authors: Lu Yanyan , Wang Hao , Li Yuhui
Published: October 2010

Boiling is an important phase-change mode with efficient heat transfer and complex bubble dynamics. A microchannel fabricated using Polydimethylsiloxane (PDMS), which is a porous polymer, performed different boiling behavior and heat transfer compared to traditional glass or silica microchannels. A very fine platinum wire embedded in the PDMS microchannel served as a heater. Bubble dynamics was visualized and recorded through a high speed CCD camera equipped in a microscope. Boiling curves were concluded, and different boiling regimes were classified. The featured phenomena of droplets cycle in big bubbles were observed and analyzed.
Influence of Water Distribution and Evolution on Measurement Accuracy of Unconsolidated Porous Media Thermal Conductivity
Authors: Yu Mingzhi , Liu Yuwang , Sui Xiaofeng , Fang Zhaohong
Published: October 2010

This paper has experimentally studied thermal conductivity measurement accuracy of unconsolidated porous media with a Hot Disk thermal constant analyzer and water distribution and evolution at pore scale by a Charge Coupled Device (CCD) combined with a microscope. It found that thermal conductivities of samples with low moisture content (<25%) can not be accurately measured. For samples with low moisture content, analysis showed that the water in the analyser sensor adjacent region, which mainly existed as isolated liquid bridges between/among sand particles, will evaporate and diffuse to relatively far regions for being heated by the sensor during measuring. Water evaporation and diffusion causes the sample construction of the sensor adjacent region varies throughout the whole measuring process, and accordingly the obtained thermal conductivities have low accuracy. In relatively high moistures content samples, water in different pores has high water connectivity and mainly exists as water mass, thus water evaporation and diffusion rates are relatively slow compared with that in low moisture content ones during measuring, meanwhile, water in the relatively far region flows back to the sensor adjacent region by capillary force. Therefore, sample construction of sensor adjacent region maintains constant and thermal conductivities of unconsolidated porous media with relatively high moisture content can be measured with high accuracy.
Turbulent Thermal Fluid Flow Transport Phenomena of Aqueous Suspensions of Nano-Particles
Authors: Torii Shuichi
Published: October 2010

The aim of the present study is to investigate the thermal fluid flow transport phenomenon of nanofluids in the heated horizontal circular tube. Consideration is given to the effects of volume fraction of the nanoparticle and Reynolds number on the turbulent heat transfer and pressure loss. Diamond, alumina (Al2O3) and oxide copper (CuO) are employed here as nanoparticles. It is found that (i) the viscosity of nanofluids increases with an increase in the volume fraction of nanoparticles dispersed in the working fluid, (ii) the pressure loss of nanofluids increases slightly in comparison with that of pure fluid and (iii) enhancement heat transfer performance is caused by suspending nanoparticles except for the case of large particle aggregation.
Thermal Image Analysis on the Axial Temperature Distribution of an AGHP (Axial Grooved Heat Pipe)
Authors: Cheng Ling , Tao Hanzhong
Published: October 2010

The wall temperature field on the condenser section of an AGHP (Axial Grooved Heat Pipe) is measured by infrared thermal imaging technology, and the temperature field information on condenser wall is obtained in the horizontal and vertical working conditions and different temperature conditions. In accordance with the temperature field, Combination of the interaction characteristics between vapor-liquid two-phase annular flow, and by calculating, the accuracy to predict the outcome on non-condensable gas region is verified. Based on the distance to evaporator outlet, the condenser of the AGHP is divided into four regions for analysis. The zone I is closest to evaporator outlet and zone IV is located at the end of condenser. There are different characteristics in 4 zones for the AGHP with different vacuum degree and working conditions. On the conditions of horizontal working status, for the high vacuum AGHP, steadily working region, small fluctuations region, large fluctuations region and temperature recovery region will appear in turn. However for the low vacuum one, the single temperature fluctuation region and a linear decline region come forth followed by the abnormal increase region and steadily working region. Recurring to the analysis of wall temperature information, the characteristics of two-phase vapor-liquid phase change heat transfer and capillary driven flow inner the AGHPs can be discerned qualitatively or semi-quantitatively and some of the laws, Such as vacuum degree, two-phase flow instability are conjectured. The research content in this paper will redound to understanding inner working mechanism for an AGHP or a small heat pipe, and at the same time, provide theory evidences for heat pipe testing in the service of mass production.
Real-Time Measurement of Chemotherapeutic Drug Transport in an Individual Cancer Cell Selected in a Microfluidic Biochip
Authors: Chen Yuchun , Li Paul C. H.
Published: October 2010

Multidrug resistance (MDR) is a significant obstacle to effective chemotherapy to many patients. Because of the overexpression of one membrane protein, P-glycoprotein (P-gp), there is an increased efflux of chemotherapeutic drug in the resistant cancer cells. The main research goal of MDR study is to get improved intracellular drug retention inside the cancer cells. So it is important to study the chemotherapeutic drug transport in the cancer cells. In this work, single leukemia CEM MDR cell has been isolated and captured by a microfluidic single-cell biochip for drug transport and retention study.
Kinetic Simulation of Heat Transfer in Microflow
Authors: Graur Irina A. , Polikarpov Alexey Ph.
Published: October 2010

The steady-state heat transfer problem between two parallel plates is investigated using kinetic models of the Boltzmann equation: BGK, S-model and ES-model. The discrete velocity method is used to determine the values of physical parameters: density, bulk velocity, temperature and heat flux. The obtained results are compared with the analytical expressions and some experimental data.
Unsteady Heat Transfer and Phase Changing Process Within Small Icing Water Droplets
Authors: Hu Hui , Jin Zheyan
Published: October 2010

We report progress made in our recent effort to develop and implement a novel, lifetime-based molecular tagging thermometry (MTT) technique to quantify unsteady heat transfer and phase changing process inside small icing water droplets pertinent to wind turbine icing phenomena. The lifetime-based MTT technique was used to achieve temporally-and-spatially resolved temperature distribution measurements within small, convectively-cooled water droplets to quantify unsteady heat transfer within the small water droplets in the course of convective cooling process. The transient behavior of phase changing process within small icing water droplets was also revealed clearly by using the lifetime-based MTT technique. Such measurements are highly desirable to elucidate underlying physics to improve our understanding about important micro-physical phenomena pertinent to ice formation and accreting process as water droplets impinging onto wind turbine in cold atmospheric environment.
Acoustically Induced Bubbles in a Microfluidic Channel for Mixing Enhancement
Authors: Wang S. S. , Huang X. Y. , Yang C.
Published: October 2010

We demonstrate acoustically bubble generation in a microfluidic channel through both experimental observation and numerical simulations. The microfluidic channel contains a nozzle-shaped actuation chamber with an acoustic resonator profile triggered by a piezoelectric disk. It has been observed that for a steady deionized (DI) water flow is driven through the channel, bubbles generation occurs in the channel when the piezoelectric disk is actuated in frequencies between 1 kHz and 5 kHz. Outside this actuation frequency range, no bubbles are generated in the channel. The experiment shows that the presence of bubbles in this frequency range can significantly enhance the fluid mixing in the microfluidic channel, which otherwise would not happen at all without the bubbles. To explain the bubble generation, a two-dimensional model is used to describe the acoustic actuated unsteady flow field. The model is solved numerically using the FLUENT software, and the numerical results shows that a low pressure regions, where water pressure is below the corresponding vapor pressure under the same temperature exists inside the actuation chamber, indicating that bubble generation can occur in this low pressure region. The bubble generation was also experimentally observed in such low pressure region by using a high speed camera. The low pressure region and bubble generation are attributed to the acoustically featured channel configuration and depend on the actuation frequency.
Effect of Nanoparticles on Forming Process of Bubbles in a Nanofluid
Authors: Su Fengmin , Ma Xuehu , Chen Jiabin
Published: October 2010

An experimental investigation was conducted to determine the effect of nanoparticles on the forming process of bubbles in the gas-liquid-nanoparticle three-phase fluidization. In the experiment, a SiO2-water nanofluid was prepared without any surfactants, and the forming process of bubbles in the nanofluid was observed by the high-speed CCD camera. The experimental results show that the diameter of the formed bubble in the nanofluid is smaller 5% than that in water, and the frequency forming bubbles in the nanofluid is higher than that in water. The investigation can provide an insight into the functionary mechanism of the bubble forming process in the gas-liquid-nanoparticles nanofluids.
The Effect of Anode Porosity on the Performance of Planar Electrode Supported Solid Oxide Fuel Cell
Authors: Yu Jianguo , Wang Yuzhang , Weng Shilie , Hui Yu
Published: October 2010

Based on CFD commercial software and the developed program which involved multi-component flow and diffusion, mass/heat transfer, electrochemical reaction and current field calculation, the performance of planar-electrode-support solid oxide fuel cell with different porosity anodes was investigated. The distributions of species concentration, temperature, electric potential, current and current density were obtained. The results show that this SOFC cell has good performance on species diffusion, current transfer and power output when anode porosity varies between 0.3 and 0.4. This work may be of significance to further research on the anode material.
Measuring the Temperature-Dependent Thermal Conductivity and Viscosity of Silver-Water Nanofluids
Authors: Godson Lazarus , Lal D. Mohan
Published: October 2010

This paper presents the measurement of the temperature dependent property such as the thermal conductivity and viscosity of silver nanoparticles suspended in water as nanofluids. The experiments were carried out over the temperatures ranging from 50°C to 90°C with 0.4%, 0.8%, and 1.2% volume concentrations. A transient hot-wire apparatus is used for measuring the thermal conductivity of nanofluids whereas the Cannon-Fenske viscometer is used to measure the viscosity of nanofluids. The results showed that the measured viscosity and thermal conductivity of nanofluids increased as the particle concentrations increased and are higher than the values of the base liquids. The minimum enhancement of 35% for 0.4 vol% and a maximum enhancement of 115% for 1.2 vol% concentration are observed at an average temperature of 70°C when compared with pure water for the same temperature. Furthermore, thermal conductivity of nanofluids increased with increasing nanofluid temperatures and, conversely, the viscosity of nanofluids decreased with increasing temperature of nanofluids. It was also observed that there exists a strong temperature effect on the thermal conductivity enhancement of nanofluids and the non-applicability of the Hamilton-Crosser model at elevated temperature with low volume fraction of pure metal nanoparticles.
Near-Field Radiative Heat Transfer Between Spherical Surfaces
Authors: Narayanaswamy Arvind , Shen Sheng , Chen Gang
Published: October 2010

Nearfield radiative transfer is known to be significantly different from that of far-field radiative transfer based on Plancks theory of blackbody radiation. Theoretical predictions point to a significant enhancement of radiative transfer between closely spaced objects due to the tunneling of surface phonon polaritons. Despite extensive theoretical predictions of enhancement between parallel surfaces, experimental evidence of near-field radiative transfer in excess of Plancks limit has been elusive due to experimental difficulties. In this talk, we will present results of our theoretical and experimental investigations into near-field radiative transfer between spherical surfaces. We have developed a sensitive technique of measuring nearfield radiative transfer between a microsphere and a substrate using a bimaterial atomic force microscope (AFM) cantilever, resulting in heat transfer-distance curves. Measurements of radiative transfer between a sphere and a flat substrate show the presence of strong nearfield effects resulting in enhancement of heat transfer over the predictions of the Planck blackbody radiation theory.
Application of Thermoelectric Waste Heat Recovery From Automobiles
Authors: Hsu C. T. , Yao D. J. , Yu B.
Published: October 2010

This article introduces a waste heat recovery system with eight thermoelectric generators (TEGs) to transfer heat to electrical energy from exhaust pipe of an automobile. Simulations and experiments for the TE module used in this system are investigated to perform the feasibility of these applications. A thermal resistor network which is used to estimate temperature difference between TE elements has been conceived. The results would establish the fundamental development of materials which enhance TEG efficiency for vehicles. In addition, the performance of a TEG module is influenced by thermal contact effect. So we clamp the TE module in our experimental apparatus by applying different pressure load to present the relationship between power output and pressure load. Through the simulation, effects upon different configurations of heat sink are also compared. Besides simulations, the system is also designed and assembled. The results would establish the fundamental development of materials which enhance TEG efficiency for vehicles.
Polymeric Labs on a Chip for Sustainable Development
Authors: Nguyen Nam-Trung , Kwok Yien-Chian , Tan Hsih Yin , Loke Weng Kong
Published: October 2010

Sustainable development is a process involving the society, the environment and the economy to meet human needs while preserving the environment. Sustainable development not only addresses the present needs but also the future needs of humanity. Lab on a chip technologies play an important role in this process. This paper reports examples of low-cost polymeric lab-on-a-chip (LOC) devices for sustainable development in food supply, namely the detection of genetically modified organisms (GMOs) and the detection of insecticides in agriculture. As the first example, the paper presents a close-loop ferrofluid-driven LOC for rapid amplification and detection of GMOs. Polymerase chain reaction (PCR) sample was contained in a circular closed microchannel and driven by magnetic force generated by an external magnet through a small oil-based ferrofluid plug. Successful amplification of genetically modified soya and maize were achieved in less than 13 minutes. The LOC provides a cost saving and less time-consuming way to conduct preliminary screening of GMOs. As the second example, the paper reports a LOC for detection of organophosphorus insecticides for occupational hygiene in agriculture. Nerve agent sarin diluted in water was used to test the device concept. The sample was tested for trace levels of regenerated sarin using immobilised cholinesterase on the chip. Activity of immobilised cholinesterase was monitored by enzyme-assisted reaction of a substrate and reaction of the end-product with a chromophore. Resultant changes in chromophore-induced absorbance were recorded on the. Loss of enzyme activity obtained prior and after passage of the treated blood sample, as shown by a decrease in recorded absorbance values, indicates the presence of either free or regenerated nerve agent in the sample.
Fabrication and Experimental Characterization of Nanochannels
Authors: Phan Vinh-Nguyen , Nguyen Nam-Trung , Yang Chun
Published: October 2010

Nanofluidics is the science and technology involving a fluid flowing in or around structures with a least one dimension in the nanoscale, which is defined as the range from 1 nm to 100 nm. In this paper, we present the fabrication and characterization of nanochannels in silicon and glass. Since the lateral dimension of the channels is limited by the wavelength of UV light used in photolithography, the channel width can only be fabricated in the micrometer scale. However, the depth of the channel can be controlled precisely by etch rate of reactive ion etching (RIE). Microchannels and access holes were etched with deep reactive ion etching (DRIE). Both nanonochannel and microchannel were sealed by a Pyrex glass wafer using anodic bonding. The fabricated nanochannels were characterized by capillary filling and evaporation experiments. Due to the small channel height and weak fluorescent signal, fluorescent techniques are not suitable for the characterization of the nanochannels. A long exposure time due to the limited amount of fluorescent molecules inhibit the measurement of transient and dynamic processes. However, as the channel height shorter than all visible wavelengths, the contrast in refractive indices of air and liquid allow clear visualization of nanochannels filled with liquids. Automatic image processing with MATLAB allows the evaluation of capillary filling in nanochannels. Interesting phenomena and discrepancies with conventional theories are presented.
Investigation of Transient Signals in Nonuniform Media Based on Diffusion Approximation
Authors: Wang Sheng-gang , Ruan Li-ming , Qi Hong , Wang Xi-ying , Li Bing-xi
Published: October 2010

With the development of the ultra-short laser technology, a new optical detection field based on the transient laser pulse signals will emerge in the future. Ultra-short laser pulses have been used in biological fields to obtain the optical properties of vivo tissues. There are many numerical models to simulate the propagation of short laser pulses in tissue medium. However, since most biological tissues show a high scattering and low absorption characteristics for near-infrared light, the most popular model is diffusion approximation method. Although with many limitations, its greatest advantage is higher computational efficiency. The propagation of short pulse laser in two dimension nonuniform medium is simulated based on the diffusion approximation model in present paper. The numerical method is validated by comparing the numerical results with the theoretical analysis results in semi-infinite uniform slab medium. Then diffusion approximation is used to simulate the transfer process of ultra-short pulses in two dimensional inhomogeneous medium. Finally, The influences of inclusions with different sizes and optical properties on time-resolved reflected signals are presented. This can help to choose suitable detection parameters in diffuse optical tomography.
Controllable Synthesis of Nanofluids With Wet Chemical Method
Authors: Zhang Can-ying , Zhu Hai-tao , Wu Da-xiong
Published: October 2010

Preparation of stable nanofluids is the first step and key issue of nanofluid research and application. A wet chemical route for controllable synthesizing of nanofluids was developed and three kinds of nanofluids were prepared using this method. Aqueous nanofluids containing CuO nanoparticle clusters with different aggregating degree were controllably synthesized by changing the reflux reaction time. Nanofluids consisting of CuS hollow spheres with different size and shell thickness were produced. Ag nanofluids with different cluster size were manipulated as well. The synthesis mechanism for the wet chemical route was proposed.
Generation and Detection of Coherent Acoustic Pulses by Femtosecond Laser Pulses
Authors: Guo Chunlei
Published: October 2010

In this paper, we systematically study the generation and propagation of coherent acoustic pulses in a metal-dielectric system using a two-color femtosecond pump-probe technique at different probe angles. A long-lived acoustic oscillation is observed in a borosilicate glass coated with gold and shows different attenuation and amplitude at different probe wavelength. Our study suggests that the two-color optical pump-probe technique can be utilized as a noninvasive tool to study acoustic properties of dielectric materials.
MD Simulation of Whisker Growth Induced by GLAD
Authors: Okumura Toshiaki , Matsumoto Mitsuhiro
Published: October 2010

We carried out MD simulations of glancing angle deposition on a high temperature substrate (HT-GLAD) to elucidate the mechanism of whisker growth, assuming Lennard-Jones model potential. The deposit shape depends on the vapor velocity, the vapor density, and the deposition angle. Through analyses of the crystalline structure and the temperature distribution inside the deposit during the whisker growth, it is found that heat transfer from the deposit to the substrate strongly affects the growth dynamics.
Sample Flow Switching Technique Based on Combined Effect of Hydrodynamic and Electroosmosis
Authors: Li Haiwang , Wong Teck Neng , Nguyen Nam-Trung
Published: October 2010

This paper presents theoretical and experimental investigations on valveless microfluidic switch using the coupled effect of hydrodynamics and electroosmosis. In the experiment, two sheath streams (aqueous NaCl and glycerol) and the sample stream (silicon oil) are introduced by syringe pumps to flow side by side in a straight rectangular microchannel. External electric fields are applied on the two sheath streams. Under the constant inlet volumetric flowrates, the sample stream is delivered to the desired outlet ports using electroosmotic effect. The liquid fractions of sheath streams are measured using fluorescence imaging technique. The results indicate that under suitable cooperation of electric fields, the sample stream can be delivered to the desired outlet ports.
Hydrodynamic Study of Nanofluids in Microchannel
Authors: Singh Pawan K. , Sundararajan T. , Das Sarit K.
Published: October 2010

Present study tries to put light on hydrodynamics of nanofluids in microchannels. For the present hydrodynamic study, the microchannels of hydraulic diameters of 212 and 301 μm are used. Present study also uses nanofluids in microchannel. To observe the hydrodynamic effect of nanofluids in microchannel, the alumina nanoparticles with sizes 45 nm are chosen with the water as base fluid. The nanofluids with the dilute concentrations 0.25 vol% are used to observe the effect of volume fraction. From the study of base fluid flow in microchannel, it is found that the axial pressure drop is linear thus showing the incompressible behaviour of fluid. For all microchannels, early transition to turbulence was observed. Also for the same Re the pressure drop was higher for smaller channel. However, the usage of nanofluids in these microchannels shows different behavior from normal fluids. The axial pressure drop was again linear thus proving that even though these fluids are different from normal fluids; they follow the behaviour of incompressible Newtonian fluids. Surprisingly, the friction factor was similar for these fluids as compared to base fluids. This can be attributed to dilute concentration of nanofluids, which make them a homogeneous fluid. It suggests that the use of dilute nanofluids in microchannel results in no or little penalty in pressure drop. It also suggests that if nanofluids have to be used as a better coolant, the hydrodynamics and heat transfer characteristics has to be studied as higher concentrations.
Development of Electrohydrodynamic Micropumps With Micropillar Electrodes
Authors: Kazemi P. Zangeneh , Selvaganapathy P. Ravi , Ching Chan Y.
Published: October 2010

Electrohydrodynamic (EHD) micropumps with three-dimensional 50μm × 50μm micropillar electrodes were fabricated and tested in this study. Two basic electrode configurations were investigated: (i) micropillar emitter and collector electrodes (symmetric) and (ii) micropillar emitter and planar collector electrodes (asymmetric). The micropumps were fabricated using chromium/gold planar electrodes with 3-D Nickel micro-pillars on a glass substrate that was integrated within a 100 μm high PDMS microchannel. The effect of the spanwise micropillar spacing spacing on the pump performance was determined. The pumps were tested using HFE-7100 as the working fluid for the maximum pressure generation under a no flow condition. The micropumps with the asymmetric electrode design generated a significantly higher pressure head and flow rate than the corresponding micropumps with symmetric electrode configuration for the same applied voltage, with lower power consumption. A decrease in the spanwise spacing of the micropillar electrodes increased the pump performance for the symmetric configuration, while the performance decreased for the asymmetric configuration.