258 results on '"Tao W"'
Search Results
2. Relating Vertical Velocity and Cloud/Precipitation Properties: A Numerical Cloud Ensemble Modeling Study of Tropical Convection.
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Tao, W.‐K., Iguchi, T., Lang, S., Li, X., Mohr, K., Matsui, T., van den Heever, S. C., and Braun, S.
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CLOUD dynamics , *ICE clouds , *VERTICAL motion , *MADDEN-Julian oscillation , *CONVECTIVE clouds , *MOTION , *VERTICAL drafts (Meteorology) , *CUMULUS clouds - Abstract
Fundamental relationships exist between cloud and precipitation development and their dynamic processes. Latent heat released by cloud/precipitation formation affects cloud vertical motions, which in turn affect convective cloud development. Here, a cloud‐resolving model is used to relate cloud properties and latent heating with cloud drafts using 15‐day simulations for an oceanic and continental environment. The results show condensation, deposition, and freezing occur mainly in moderate (3–5 m s−1) to strong (>10 m s−1) updrafts, evaporation and sublimation mainly in weak (1–2 m s−1) to moderate downdrafts, and melting in moderate updrafts and downdrafts. Active updrafts cover only a small percentage of the model domain but contribute significantly to the latent heat release and are associated with large proportions of the hydrometeors. Active updrafts with vertical velocities exceeding 1 and 2 m s−1 account for more than 75% and 50%, respectively, of the condensation, deposition, and freezing in both the oceanic and continental cases. However, active downdrafts with vertical velocity magnitudes exceeding |1 m s−1| account for less than 40% and 25%, respectively, of the evaporation and sublimation. More evaporation and sublimation than condensation and deposition occur in the inactive cloud regions. Sensitivity tests are also conducted to assess the impact of model grid spacing (1,000 m vs. 250 m) and microphysical schemes (3 ice classes vs. 4 ice classes) on latent heat release and hydrometeor amount. The results show that model resolution had more impact than the microphysics on the simulated cloud properties in both cases. Plain Language Summary: Long‐term, 2D Goddard Cumulus Ensemble model simulations for one tropical oceanic (Dynamics of the Madden‐Julian Oscillation) and one tropical continental (Green Ocean Amazon Experiment) case were conducted to examine the relationship between latent heating (LH) processes and cloud properties (hydrometeors) with respect to the vertical velocity. The model simulated a population of different types of clouds and convective systems over their respective life cycles in both cases. The simulated LH processes and cloud properties were then separated into convective and stratiform regions, as well as active and inactive cloud regimes. The results show that almost all condensation, deposition, and freezing occur in the upward motion region while evaporation and sublimation mainly are in the downward motion region. Melting can occur in both updraft and downdraft regions. The results also indicate that active updrafts cover only a small area (a few percent) of the model domain where the most condensation and freezing occur. But more evaporation and sublimation occur in the inactive downdraft regions. Sensitivity tests show that the model resolution (250 and 1,000 m) had more impact than the microphysical scheme (3 classes of ice vs. 4 classes ice) on the simulated cloud properties in both cases. Key Points: Two‐dimensional cloud‐resolving model simulations show that storm dynamics and cloud microphysics are strongly coupledCondensation, deposition, and freezing concentrate mainly in moderate to strong updrafts, which occupy a small area of the model domainEvaporation and sublimation process occur in weak to moderate downdrafts over a more extensive area [ABSTRACT FROM AUTHOR]
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- 2022
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3. IMPACT OF CATHODE SLOT ON CURRENT DISTRIBUTION IN CATHODE CARBON OF AN ALUMINUM ELECTROLYTICl CELL.
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HE, J. G., TAO, W. J., LI, Y., DONG, G. Z., and CUI, X. X.
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CURRENT distribution , *ELECTROLYTIC cells , *CATHODES , *ALUMINUM , *FINITE element method , *ALUMINUM foam - Abstract
The current distribution in a fresh aluminum electrolytic cell with slotted carbons is investigated by the Finite Element Method (FEM). The effects of the length of slots, la and lc on current distribution were also determined. The maximum local current density and its position do not change with an increase in lc (0 ≤ lc ≤ 200 mm) for a 400 mm slot located 150 mm from the upper surface of the cathode carbon. However, the maximum current density shifts towards the cell center with increasing slot lengths. Current distribution control thus plays a role in optimizing the cathode slot length. [ABSTRACT FROM AUTHOR]
- Published
- 2022
4. On representations of the centrally extended Heisenberg double of SL2.
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Tao, W.-Q.
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FACTORS (Algebra) , *LINEAR codes - Abstract
For the centrally extended Heisenberg double of SL2, its center is determined, the central factor algebras are described, and classifications of simple Harish-Chandra modules, simple Whittaker modules, and simple quasi-Whittaker modules are obtained. Two classes of simple weight modules with infinite-dimensional weight spaces are given. We also give a classification of simple modules that decompose into a direct sum of simple finite-dimensional s l 2 -modules with finite multiplicities. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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5. Spatial Distribution and Variation Characteristics of Saturated Hydrologic Conductivity on the Chinese Loess Plateau.
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Yang, Y., Yan, H. K., Tao, W. H., and Su, L. J.
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SPATIAL variation , *HYDRAULIC conductivity , *FORESTS & forestry , *SOIL depth , *SOIL physics , *LAND cover - Abstract
The Chinese Loess Plateau (CLP) plays a vital role as an ecological barrier in maintaining the hydrological and climatic conditions of the Yellow River Basin, preventing desertification, and preserving biodiversity. Conducting a systematic analysis and assessment of the saturated hydrological conductivity (Ksat) on the Loess Plateau is crucial for modeling and simulating processes like surface runoff and solute migration. However, due to the uncertainty in detecting the saturated hydraulic conductivity, there are very few regional spatial analyses of the saturated hydraulic conductivity of the CLP. The research results show that the Campbell model is more suitable for the CLP than others. Spatially, Ksat gradually decreases from northwest to southeast. The Ksat in the surface layer (0 cm) was significantly larger than that at the lower soil depths, and the Ksat variability of each soil layer was moderate. Moran;s I decreased as the lag distance increased; this indicated a positive spatial correlation between Ksat and the correlation gradually decreasing with distance. The scattered points are mainly located in the first quadrant, so the local spatial auto-correlation characteristics of the Ksat in this area are clustered with high values. The Ksat for different land cover on the CLP increases in the order grassland > forest land > agricultural land and increases with elevation. This study improves our understanding of land resources and ecological environment management in the CLP. [ABSTRACT FROM AUTHOR]
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- 2024
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6. Three-dimensional lattice Boltzmann model for gaseous flow in rectangular microducts and microscale porous media.
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Tang, G. H., Tao, W. Q., and He, Y. L.
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Microscale fluid dynamics has received intensive interest due to the rapid advances in microelectromechanical systems. In this work, the lattice Boltzmann method is applied to simulate isothermal gaseous slip flow in three-dimensional (3D) rectangular microducts and microscale porous structures. The flow characteristics in 3D microducts--including velocity profile, nonlinear pressure distribution, friction factor, and mass flow rate--are compared with analytical solutions, and the agreement is good. The flow-rate results show that due to the slip-velocity emergence at the walls, the lateral wall influence on the flow rate in 3D rectangular microducts is decreased. The predicted transport characteristics in 3D microscale porous media show that the rarefaction influence increases the gas permeability. The Klinkenberg effect is confirmed and the predicted gas permeability is qualitatively consistent with the experimental results. Furthermore, the nonlinear behavior of the porous flow at relatively higher Reynolds number is also observed. This study demonstrates that the lattice Boltzmann method can be employed to efficiently predict transport characteristics in microducts and microscale porous media. [ABSTRACT FROM AUTHOR]
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- 2005
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7. First results of upgraded beam emission spectrometer on EAST.
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Tao, W., Li, Y.Y., Zhou, Y.X., Jiang, D., Fu, J., Mao, S.F., Yu, Y., Lyu, B., Shi, Y.J., Wan, B.N., and Ye, M.Y.
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CHARGE exchange , *EMISSION spectroscopy , *NEUTRAL beams , *SPECTRAL lines , *SPECTROMETERS - Abstract
• The beam emission spectroscopy (BES) system has recently been upgraded and operated successfully in the 2018 experimental campaign on EAST. • A curved mask strip manufactured by photolithography technology suppresses the intense edge Dα line. • Efficiency of curved strip and performances of BES spectrometer are calibrated using the integrating sphere and spectral lamps respectively. • The beam emission spectral lines and active charge exchange line emitted by main ions are measured simultaneously. The beam emission spectroscopy (BES) system that shares the collection optics with the core charge exchange recombination spectroscopy (cCXRS) has recently been upgraded on EAST. The enhanced system aims at the simultaneous measurements of the neutral beam emission from the co-current and counter-current neutral beam injection (NBI) as well as the active charge exchange line (Dα, n = 3→2, 656.1 nm) from the interaction of the main ions and the injected neutral beam. The operating spectral band of the system is 656.1 ± 6 nm, with respect to the maximum Doppler shift and stark splitting induced by the highest energy of 80 keV for deuterium beam. Strong edge Dα line is effectively suppressed by one curved chromate strip (˜3% transmission and ˜83 μm width) on the fused silica. Main ion Dα emission and beam emission spectra are acquired simultaneously without any saturation of the signal on the detector. In this paper, an overview of the upgraded spectrometer will be shown and the first experimental results are presented. [ABSTRACT FROM AUTHOR]
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- 2019
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8. Expanding the Goddard CSH Algorithm for GPM: New Extratropical Retrievals.
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Tao, W.-K., Iguchi, T., and Lang, S.
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WEATHER forecasting , *HYDROLOGIC cycle , *EVAPORATION (Chemistry) , *CYCLONES , *METEOROLOGICAL precipitation - Abstract
The Goddard convective–stratiform heating (CSH) algorithm has been used to retrieve latent heating (LH) associated with clouds and cloud systems in support of the Tropical Rainfall Measuring Mission and Global Precipitation Measurement (GPM) mission. The CSH algorithm requires the use of a cloud-resolving model to simulate LH profiles to build lookup tables (LUTs). However, the current LUTs in the CSH algorithm are not suitable for retrieving LH profiles at high latitudes or winter conditions that are needed for GPM. The NASA Unified-Weather Research and Forecasting (NU-WRF) Model is used to simulate three eastern continental U.S. (CONUS) synoptic winter and three western coastal/offshore events. The relationship between LH structures (or profiles) and other precipitation properties (radar reflectivity, freezing-level height, echo-top height, maximum dBZ height, vertical dBZ gradient, and surface precipitation rate) is examined, and a new classification system is adopted with varying ranges for each of these precipitation properties to create LUTs representing high latitude/winter conditions. The performance of the new LUTs is examined using a self-consistency check for one CONUS and one West Coast offshore event by comparing LH profiles retrieved from the LUTs using model-simulated precipitation properties with those originally simulated by the model. The results of the self-consistency check validate the new classification and LUTs. The new LUTs provide the foundation for high-latitude retrievals that can then be merged with those from the tropical CSH algorithm to retrieve LH profiles over the entire GPM domain using precipitation properties retrieved from the GPM combined algorithm. [ABSTRACT FROM AUTHOR]
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- 2019
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9. A low-temperature scanning tunneling microscope capable of microscopy and spectroscopy in a Bitter magnet at up to 34 T.
- Author
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Tao, W., Singh, S., Rossi, L., Gerritsen, J. W., Hendriksen, B. L. M., Khajetoorians, A. A., Christianen, P. C. M., Maan, J. C., Zeitler, U., and Bryant, B.
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SCANNING tunneling microscopy , *DAMPING (Mechanics) , *VIBRATION (Mechanics) , *PYROLYTIC graphite , *GRAPHITE - Abstract
We present the design and performance of a cryogenic scanning tunneling microscope (STM) which operates inside a water-cooled Bitter magnet, which can attain a magnetic field of up to 38 T. Due to the high vibration environment generated by the magnet cooling water, a uniquely designed STM and a vibration damping system are required. The STM scan head is designed to be as compact and rigid as possible, to minimize the effect of vibrational noise as well as fit the size constraints of the Bitter magnet. The STM uses a differential screw mechanism for coarse tip—sample approach, and operates in helium exchange gas at cryogenic temperatures. The reliability and performance of the STM are demonstrated through topographic imaging and scanning tunneling spectroscopy on highly oriented pyrolytic graphite at T = 4.2 K and in magnetic fields up to 34 T. [ABSTRACT FROM AUTHOR]
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- 2017
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10. Copolymerisation of ethylene with polar monomers by using palladium catalysts bearing an N-heterocyclic carbene–phosphine oxide bidentate ligand.
- Author
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Tao, W., Akita, S., Nakano, R., Ito, S., Nozaki, K., Hoshimoto, Y., and Ogoshi, S.
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COPOLYMERIZATION , *ETHYLENE , *MONOMERS - Abstract
We report the synthesis and characterisation of palladium complexes bearing an N-heterocyclic carbene–phosphine oxide bidentate ligand and their use as catalysts for ethylene polymerisation and ethylene/polar monomer copolymerisation. [ABSTRACT FROM AUTHOR]
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- 2017
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11. Neuraxial analgesia effects on labour progression: facts, fallacies, uncertainties and the future.
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Grant, EN, Tao, W, Craig, M, McIntire, D, and Leveno, K
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ANALGESIA , *DRUG side effects , *LABOR pain (Obstetrics) , *PAIN management - Abstract
Approximately 60% of women who labour in the USA receive some form of neuraxial analgesia, but concerns have been raised regarding whether it negatively impacts the labour and delivery process. In this review, we attempt to clarify what has been established as truths, falsities and uncertainties regarding the effects of this form of pain relief on labour progression, negative and/or positive. Additionally, although the term 'epidural' has become synonymous with neuraxial analgesia, we discuss two other techniques, combined spinal-epidural and continuous spinal analgesia, that are gaining popularity, as well as their effects on labour progression. [ABSTRACT FROM AUTHOR]
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- 2015
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12. NUMERICAL SIMULATION ELECTRIC DISTRIBUTION IN ALUMINUM REDUCTION CELL WITH VERTICAL COLLECTOR BARS.
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TAO, W. J., WANG, Z. W., GAO, B. L., SHI, Z. N., HU, X. W., and CUI, J. Z.
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ALUMINUM , *CHEMICAL reduction , *THERMOELECTRICITY , *ELECTRIC currents , *TURBULENCE , *COMPUTER simulation - Abstract
The electric current distributions in cathode were calculated using a 3D thermal-electric model. The results show that the cell with vertical collector bars has a uniform voltage (electric current density) in the cathode carbon across the entire cell width than that of a conventional cell. Furthermore, the horizontal density in the metal pad with vertical collector bars is far less than that in the conventional cell, which indicates that the cell with vertical collectors will generate the minor metal turbulence and the polar distance can be control in a minor and uniform value. [ABSTRACT FROM AUTHOR]
- Published
- 2014
13. On simple modules of the n-th Schrödinger algebra.
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Tao, W.-Q.
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UNIVERSAL algebra , *ALGEBRA , *INDECOMPOSABLE modules - Abstract
The n -th Schrödinger algebra sch n : = sl 2 ⋉ h n is the semi-direct product of the Lie algebra sl 2 with the n -th Heisenberg Lie algebra h n. We give a classification of simple Harish-Chandra modules and simple Whittaker modules over the n -th Schrödinger algebra. We determine the centres of some algebras that are related to the universal enveloping algebra of the n -th Schrödinger algebra. [ABSTRACT FROM AUTHOR]
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- 2022
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14. Synthesis, crystal structure, and porosity calculation of novel lanthanide coordination polymers involving naphthalene-1,4,5,8-tetra-carboxylate as ligand.
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Tao, W., Liu, J., Zheng, Y., and Sun, C.
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POROUS materials , *CRYSTALLOGRAPHY , *POROSITY , *CRYSTAL structure research , *CARBOXYLIC acids - Abstract
Two isostructural microporous coordination polymers of 1,4,5,8-naphthalenetetracarboxylic acid (HNtc) with rare earth metals were obtained in gel diffusion method, with chemical formulae [Y(Ntc)(HO)] · 6HO) ( I) and [Er(Ntc)(HO)] · 6HO ( II). They crystallized in the monoclinic system, space group P2/ c. The crystal structure study revealed two crystallographically independent La ions, and two crystallographically independent ligands were in the structure of the compounds I and II. Their crystal structure were 3D and exhibited some large channels with rectangular sections spreading along the x axis. The porosity has been calculated using Connolly's algorithm after the crystallization water molecules were formally removed. [ABSTRACT FROM AUTHOR]
- Published
- 2013
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15. A Laser Scanning System for the Inspection of Fasteners in Railways.
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ZHANG, H., TAO, W., LIU, M., and ZHAO, H.
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LASERS , *SCANNING systems , *FASTENERS , *HIGH speed trains , *RAILROADS , *ENGINEERING inspection , *COMPARATIVE studies - Abstract
With the rapid growth of high-speed railways, the demand for automatic railway inspection, including fastener inspection, has increased. Most studies related to fastener inspection have focused on image processing and recognition technologies, which entail high computational costs and make real-time implementation difficult in high-speed applications. This paper proposes a laser scanning system based on motion images to improve time efficiency in fastener inspection. Compared with conventional methods, the captured image using the proposed method is of high contrast, easy to process and provides much depth information, which is useful for detection. We also introduced mathematical descriptions of the proposed method. Finally, we built an experimental system to simulate the practical system in high-speed railways at a speed of 300 km/h. Image processing achieved a recognition accuracy of 98.25%, implying the proposed method can inspect a high-speed moving object with high accuracy. [ABSTRACT FROM AUTHOR]
- Published
- 2013
16. Is phosphoproteomics ready for clinical research?
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Iliuk, Anton B. and Tao, W. Andy
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PROTEOMICS , *CANCER treatment , *PHOSPHORYLATION , *CELLULAR signal transduction , *GENOMICS , *SYSTEMS biology , *DISEASE progression - Abstract
Abstract: Background: For many diseases such as cancer where phosphorylation-dependent signaling is the foundation of disease onset and progression, single-gene testing and genomic profiling alone are not sufficient in providing most critical information. The reason for this is that in these activated pathways the signaling changes and drug resistance are often not directly correlated with changes in protein expression levels. In order to obtain the essential information needed to evaluate pathway activation or the effects of certain drugs and therapies on the molecular level, the analysis of changes in protein phosphorylation is critical. Methods: Existing approaches do not differentiate clinical disease subtypes on the protein and signaling pathway level, and therefore hamper the predictive management of the disease and the selection of therapeutic targets. Conclusions: The mini-review examines the impact of emerging systems biology tools and the possibility of applying phosphoproteomics to clinical research. [Copyright &y& Elsevier]
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- 2013
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17. Simultaneous Saccharification and Fermentation of Rice Straw Pretreated by a Sequence of Dilute Acid and Dilute Alkali at High Dry Matter Content.
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Sun, W.-L. and Tao, W.-Y.
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LIGNINS , *CELLULOSE , *HYDROLYSIS , *RICE straw , *BIOCHEMICAL engineering , *HEMICELLULOSE - Abstract
In lignocellulosic materials, the presence of lignin and hemicellulose makes the access of enzymes to cellulose difficult, thus reducing the efficiency of the hydrolysis. To improve the substrate hydrolysis for ethanol production, and to decrease the ethanol cost, rice straw was pretreated by a sequence of dilute acid and dilute alkali to remove lignin and hemicellulose, and then the production of bio-ethanol from the pretreated rice straw using simultaneous saccharification and fermentation at high dry content was investigated. After the complex pretreatment, the cellulose content in rice straw increased from 41.5 to 88.5%. Complex method and dilute acid pretreatment of rice straw result in glucose concentrations of 101.7 and 50.2 g/L, respectively. As a result, ethanol concentration of 58.7 g/L was obtained by simultaneous saccharification and fermentation of rice straw pretreated using a sequence of dilute acid and dilute alkali at a substrate concentration of 160 g/L; the ethanol yield was 73.4% based on the glucose content in the raw material. A biorefinery combining a sequence of dilute acid and dilute alkali pretreatment with commercial ethanol instant active dry yeast (S. cerevisiae) in SSF could achieve 175 g EtOH/kg untreated rice straw. [ABSTRACT FROM PUBLISHER]
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- 2013
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18. Double-sided laser beam welded T-joints for aluminum aircraft fuselage panels: Process, microstructure, and mechanical properties
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Yang, Z.B., Tao, W., Li, L.Q., Chen, Y.B., Li, F.Z., and Zhang, Y.L.
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FUSELAGE (Airplanes) , *WELDED joints , *LASER beams , *ALUMINUM , *STRUCTURAL plates , *METAL microstructure , *MECHANICAL properties of metals - Abstract
Abstract: T-joints consisting of 1.8mm thick AA6156-T6/AA6056-T4 aluminum alloys have been fabricated by double-sided laser beam welding using eutectic alloy AA4047 filler wire. The effects of the incident beam position, the incident beam angle, and the beam separation distance on the weld properties were investigated. The microstructure and mechanical properties were identified using optical microscopy, scanning electron microscopy, and tensile testing. The optimal incident beam position was determined to be 0.2mm yielding a 40–50° seam angle. It was found that the weld penetration was increased significantly as the incident beam angle increased. The doubled-sided welds were not fused in a common molten pool and no longer symmetry when the beam separation distance exceeded to 1.5mm. Five distinct zones were identified between the fusion zone center and the base material which consisted of: the cellular dendrite zone, parallel dendrite zone, partially melted zone, over-aged zone, and base material. The tensile strength depended on the weld penetration, and the failure originated at the weld toe on the skin side. The fracture mechanism of the head tensile test and hoop tensile test was found to be brittle fracture and ductile fracture, respectively. [Copyright &y& Elsevier]
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- 2012
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19. CAC2634-disrupted mutant of Clostridium acetobutylicum can be electrotransformed in air.
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Dong, H., Tao, W., Zhu, L., Zhang, Y., and Li, Y.
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CLOSTRIDIUM acetobutylicum , *GENETIC code , *PEROXIDES , *DNA , *NUCLEIC acids , *GENETIC mutation , *MICROBIOLOGY - Abstract
Aims: To simplify the electrotransformation process of Clostridium acetobutylicum, which currently needs to be performed in an anaerobic chamber, thus laborious and time-consuming. Methods and Results: The CAC2634 gene encoding PerR is a known peroxide regulon repressor in Cl. acetobutylicum. CAC2634 in a previously constructed Restriction-Modification system deficient Cl. acetobutylicum mutant SMB009 was disrupted using ClosTron method. The resulted mutant SMB012 can be electrotransformed in air with an efficiency of 1·2-3·1 × 103 transformants μg−1 DNA. Conclusions: We demonstrated that the disruption of CAC2634 in Cl. acetobutylicum enables its electrotransformation in air. Significance and Impact of the Study: The electrotransformation process of Cl. acetobutylicum could be significantly simplified, especially when operating multiple electrotransformations. [ABSTRACT FROM AUTHOR]
- Published
- 2011
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20. Crystal growth and characterization of Haldane chain compound Ni(C3H10N2)2NO2ClO4
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Tao, W., Chen, L.M., Wang, X.M., Fan, C., Ke, W.P., Liu, X.G., Zhao, Z.Y., Li, Q.J., and Sun, X.F.
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CRYSTAL growth , *TEMPERATURE effect , *NICKEL compounds , *THERMAL conductivity , *SOLVENTS , *MAGNETIC materials , *X-ray diffraction , *MAGNETIC susceptibility - Abstract
Abstract: The bulk single crystals of S=1 chain compound Ni(C3H10N2)2NO2ClO4 are grown by using a slow evaporation method at a constant temperature and a slow cooling method. It is found that the optimum condition of growing large crystals is via slow evaporation at 25°C using 0.015mol , 0.015mol NaNO2, and 0.03mol 1,3-propanediamine liquid dissolved into 30ml aqueous solvent. High-quality crystals with size up to mm3 are obtained. The single crystals are characterized by measurements of X-ray diffraction, magnetic susceptibility, specific heat and thermal conductivity. The susceptibilities along three crystallographic axes are found to exhibit broad peaks at , and then decrease abruptly to zero at lower temperatures, which is a characteristic of a Haldane chain system. The specific heat and the thermal conductivity along the c-axis can be attributed to the simple phononic contribution and are analyzed using the Debye approximation. [Copyright &y& Elsevier]
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- 2011
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21. Facile Determination of Double Bond Position in Unsaturated Fatty Acids and Esters by Low Temperature Plasma Ionization Mass Spectrometry.
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Zhang, J. Isabella, Tao, W. Andy, and Cooks, R. Graham
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UNSATURATED fatty acids , *MASS spectrometry , *IONIZATION (Atomic physics) , *ALKENES , *ESTERS - Abstract
Unsaturated fatty acids and esters can be oxidized in situ during ionization using a low temperature plasma (LTP) probe. The discharge generates ozone from air that reacts with and cleaves olefins. The molecular ions of the resulting acid/ester oxidation products are present in the full scan mass spectra and are confirmed by exact mass measurements. The fragmentation information can be used to assign double bond positions. We have successfully applied this strategy to a range of mono-/polyunsaturated fatty acids and fatty acid methyl/ethyl esters to assign their double bond locations. The procedure allows rapid and direct identification of double bond positions in situ at atmospheric pressure without sample preparation prior to mass spectrometric analysis. Microbial fatty acid ethyl ester (FAEE) mixtures from complex bacterial samples were directly analyzed by this method. Structural confirmation of their diagnostic ions by using exact mass measurements and tandem mass spectrometry confirms double bond positions in unsaturated bacterial FAEEs. [ABSTRACT FROM AUTHOR]
- Published
- 2011
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22. WRF Simulations of the 20-22 January 2007 Snow Events over Eastern Canada: Comparison with In Situ and Satellite Observations.
- Author
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Shi, J. J., Tao, W-K., Matsui, T., Cifelli, R., Hou, A., Lang, S., Tokay, A., Wang, N-Y., Peters-Lidard, C., Skofronick-Jackson, G., Rutledge, S., and Petersen, W.
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METEOROLOGICAL precipitation measurement , *SNOW , *METEOROLOGICAL research , *WEATHER forecasting , *SATELLITE meteorology , *SYNOPTIC climatology , *RADIATION measurements , *SIMULATION methods & models - Abstract
One of the grand challenges of the Global Precipitation Measurement (GPM) mission is to improve cold-season precipitation measurements in mid- and high latitudes through the use of high-frequency passive microwave radiometry. For this purpose, the Weather Research and Forecasting model (WRF) with the Goddard microphysics scheme is coupled with a Satellite Data Simulation Unit (WRF-SDSU) to facilitate snowfall retrieval algorithms over land by providing a virtual cloud library and corresponding microwave brightness temperature measurements consistent with the GPM Microwave Imager (GMI). When this study was initiated, there were no prior published results using WRF at cloud-resolving resolution (1 km or finer) for high-latitude snow events. This study tested the Goddard cloud microphysics scheme in WRF for two different snowstorm events (a lake-effect event and a synoptic event between 20 and 22 January 2007) that took place over the Canadian CloudSat/Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) Validation Project (C3VP) site in Ontario, Canada. The 24-h-accumulated snowfall predicted by WRF with the Goddard microphysics was comparable to that observed by the ground-based radar for both events. The model correctly predicted the onset and termination of both snow events at the Centre for Atmospheric Research Experiments site. The WRF simulations captured the basic cloud patterns as seen by the ground-based radar and satellite [i.e., CloudSat and Advanced Microwave Sounding Unit B (AMSU-B)] observations, including the snowband featured in the lake event. The results reveal that WRF was able to capture the cloud macrostructure reasonably well. Sensitivity tests utilizing both the '2ICE' (ice and snow) and '3ICE' (ice, snow, and graupel) options in the Goddard microphysical scheme were also conducted. The domain- and time-averaged cloud species profiles from the WRF simulations with both microphysical options show identical results (due to weak vertical velocities and therefore the absence of large precipitating liquid or high-density ice particles like graupel). Both microphysics options produced an appreciable amount of liquid water, and the model cloud liquid water profiles compared well to the in situ C3VP aircraft measurements when only grid points in the vicinity of the flight paths were considered. However, statistical comparisons between observed and simulated radar echoes show that the model tended to have a high bias of several reflectivity decibels (dB Z), which shows that additional research is needed to improve the current cloud microphysics scheme for the extremely cold environment in high latitudes, despite the fact that the simulated ice/liquid water contents may have been reasonable for both events. Future aircraft observations are also needed to verify the existence of graupel in high-latitude continental snow events. [ABSTRACT FROM AUTHOR]
- Published
- 2010
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23. Growth of (CH3)2NH2CuCl3 single crystals using evaporation method with different temperatures and solvents
- Author
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Chen, L.M., Tao, W., Zhao, Z.Y., Li, Q.J., Ke, W.P., Wang, X.M., Liu, X.G., Fan, C., and Sun, X.F.
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CRYSTAL growth , *COPPER compounds , *EVAPORATION (Chemistry) , *X-ray diffraction , *TEMPERATURE effect , *MAGNETS , *SOLUTION (Chemistry) , *RECRYSTALLIZATION (Metallurgy) - Abstract
Abstract: The bulk single crystals of low-dimensional magnet (CH3)2NH2CuCl3 (DMACuCl3 or MCCL) are grown by a slow evaporation method with different kinds of solvents, different degrees of super-saturation of solution and different temperatures of solution, respectively. Among three kinds of solvent, methanol, alcohol and water, alcohol is found to be the best one for growing MCCL crystals because of its structural similarity to the raw materials and suitable evaporation rate. The best growth temperature is in the vicinity of 35°C. The problem of the crystals deliquescing in air has been solved through recrystallization process. The crystals are characterized by means of X-ray diffraction, specific heat and magnetic susceptibility. [ABSTRACT FROM AUTHOR]
- Published
- 2010
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24. Two new isopimarane diterpenes from the feces of Trogopterus xanthipes.
- Author
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Yang N, Tao W, Zhu M, Duan J, and Jiang J
- Abstract
Chemical investigation of Trogopterus Feces has led to the isolation of two new isopimarane diterpenes, wulingzhic acid A (1) and wulingzhic acid B (2). Their structures were elucidated by chemical and extensive spectral analysis. Compounds 1 and 2 exhibited weak activity of antithrombin and moderate activity of antiplatelet aggregation in vitro. [ABSTRACT FROM AUTHOR]
- Published
- 2010
- Full Text
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25. Regulation effects on abnormal glucose and lipid metabolism of TZQ-F, a new kind of traditional Chinese medicine.
- Author
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Tao W, Deqin Z, Yuhong L, Hong L, Zhanbiao L, Chunfeng Z, Limin H, and Xiumei G
- Abstract
AIM OF THE STUDY: Based on the recipe of the traditional anti-diabetic formula TZQ, we developed TZQ-F, a new formula including 8 fractions isolated from Red Paeony root, Mulberry leaf, Lotus leaf, Danshen root and Hawthorn leaf with a good quality assurance. The study was aimed at fraction preparation and effects of the fractions on abnormal glucose and lipid metabolism. MATERIALS AND METHODS: The active fractions were obtained by macroporous resin, ion-exchange resin and polyamide resin column chromatographies. HPLC analyses were used for quality control. In vitro mechanism study included DPPH radical scavenging, AGEs formation inhibition, alpha-glucosidase inhibition and lipase inhibition, and rats on high-fat diet were used for in vivo study. RESULTS: In vitro mechanism study showed that among the 8 fractions, three of them had inhibition effects on intestinal disaccharase, three with inhibition effects on lipase, and five with effects of free radical scavenging. In vivo study showed that after 4 weeks of treatment, TZQ-F significantly decreased the levels of serum total cholesterol, TG, glucose, LDL-C and HDL-C in rats on high-fat diet. Consistent with the in vitro and in vivo results, histology study demonstrated that TZQ-F alleviated hepatic steatosis induced by high-fat diet. CONCLUSIONS: TZQ-F possesses the potential regulation effects on abnormal glucose and lipid metabolism. [ABSTRACT FROM AUTHOR]
- Published
- 2010
- Full Text
- View/download PDF
26. Two new cerebrosides from the pollen of Typha angustifolia.
- Author
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Tao W, Yang N, Liu L, Duan J, Wu D, Qian D, and Tang Y
- Abstract
Two new cerebrosides, 1-O-(beta-d-glucopyranosyloxy)-(2S,3S,4R,8Z)-2-[(2'R)-2'-hydroxytricosanoylamino]-8-nonadecene-3,4-diol (1) and 1-O-(beta-D-glucopyranosyloxy)-(2S,3R,4E,8Z)-2-[(2'R)-2'-hydroxynonadecanoylamino]-4,13-nonadecene-3-diol (2), were isolated from the pollen of Typha angustifolia. Their structures were elucidated by chemical and spectral means. This is the first report on the occurrence of cerebroside in Typha (Typhaceae). Compounds 1 and 2 exhibited effect on the proliferation of cultured vascular smooth muscle cell (VSMCs) induced by fatal bovine serum (FBS). Copyright (c) 2009 Elsevier B.V. All rights reserved. [ABSTRACT FROM AUTHOR]
- Published
- 2010
- Full Text
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27. Determination of biflavones from trogopterus feces by HPLC.
- Author
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Yang N, Tao W, and Duan J
- Published
- 2009
28. Joint strength and failure mechanism of laser spot weld of mild steel sheets under lap shear loading.
- Author
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Tao, W., Li, L. Q., Chen, Y. B., and Wu, L.
- Subjects
- *
ELECTRIC welding , *INDUSTRIAL lasers , *ELECTRIC equipment , *AUTOMOBILE industry , *LASER welding , *INDUSTRIAL engineering - Abstract
Ultimate strength and failure mechanism of laser spot welds under lap shear loading were investigated. Optical micrographs of cross-section of spot welds before and after failure were examined to understand the failure behaviour. The experimental results indicate that laser spot welds can fail in two distinct modes, namely interfacial and pullout failure. A failure mechanism which was confirmed by SEM investigations was proposed to describe these two failure modes. According to the experimental observations, a simple stress solution related to the far field load was conducted and the critical weld nugget diameter to ensure pullout failure mode was estimated. The results were compared with the experimental data and also with the test data of resistance spot welds. It was observed that the critical nugget diameter of laser spot welding was larger than that of resistance spot welding due to the different failure location in pullout mode. Furthermore, the effect of welding parameters on joint strength and failure mode was studied. [ABSTRACT FROM AUTHOR]
- Published
- 2008
- Full Text
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29. Chemiluminescence determination of gossypol at trace levels using flow injection as sample introduction techniques.
- Author
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Bingchun, X., Tao, W., and Erbao, L.
- Subjects
- *
CHEMILUMINESCENCE , *GOSSYPOL , *SODIUM hydroxide , *LUMINESCENCE , *PLANT pigments - Abstract
A simple and sensitive flow injection method with chemiluminescence ( CL) detection is developed for the determination of gossypol at trace levels. The method is based on the reaction of luminol with ferricyanid in a sodium hydroxide medium sensitized by gossypol. Under the optimum conditions, the CL intensity is proportional to the concentration of gossypol over the range of 1.11 × 10−17 − 2.78 × 10−16 M in an acidic solution and 8.00 × 10−11 − 7.39 × 10−8 M in a neutral solution with correlation coefficients of 0.9983 and 0.9905, respectively. The detection limit is 1.48 × 10−18 M (3σ). The proposed method has been applied to the determination of gossypol in cottonseeds and pharmaceutical preparations with satisfactory results. The CL mechanism is discussed by examining the CL emission spectrum and the effect of various free radical scavengers on the CL emission intensity. [ABSTRACT FROM AUTHOR]
- Published
- 2008
- Full Text
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30. BCR-ABL oncogenic transformation of NIH 3T3 fibroblasts requires the IL-3 receptor.
- Author
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Tao, W. J., Lin, H., Sun, T., Samanta, A. K., and Arlinghaus, R.
- Subjects
- *
HEMATOPOIETIC growth factors , *PROTEIN-tyrosine kinases , *INTERLEUKIN-3 , *CARCINOGENESIS , *METHANESULFONATES - Abstract
Oncogenic transformation of hematopoietic cells by the Bcr-Abl oncoprotein directly involves the activation Jak2 tyrosine kinase and the Stat5 transcription factor. Both proteins are normally linked to the interleukin (IL)-3/granulocyte-macrophage colony-stimulating factor receptors for growth and survival. Since fibroblastic cells are not targets of BCR-ABL-induced oncogenesis, we determined whether forced expression of the IL-3 receptor would allow oncogenic transformation of NIH 3T3 fibroblasts known to be resistant to transformation by BCR-ABL. NIH 3T3 cells transduced with the human IL-3 receptor α and β chains were highly susceptible to oncogenic transformation by expression of BCR-ABL. Forced expression of both receptor chains but not either one alone allowed efficient foci formation of NIH 3T3 cells expressing BCR-ABL (triple positive cells), and these cells formed colonies in soft agar, whereas BCR-ABL+ NIH 3T3 cells lacking IL-3 receptor expression did not. Signaling studies indicate that the BCR-ABL/IL-3 receptor+ NIH 3T3 cells utilize the Gab2/PI-3 kinase pathway activated by Jak2, and the Stat5 pathway activated separately by Bcr-Abl, whereas BCR-ABL+ NIH 3T3 cells lacking the IL-3 receptor do not utilize the Jak2 pathway, but still maintain activation of Stat5. The Bcr-Abl kinase inhibitor imatinib mesylate (1 μM) and two Jak2 kinase inhibitors strongly inhibited agar colony formation and the activation of Gab2 caused by Jak2. All of these findings indicate that Bcr-Abl oncoprotein requires the IL-3 receptor/Jak2/Stat5 pathways for oncogenic transformation of NIH 3T3 fibroblasts.Oncogene (2008) 27, 3194–3200; doi:10.1038/sj.onc.1210979; published online 10 December 2007 [ABSTRACT FROM AUTHOR]
- Published
- 2008
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31. Analysis of Inconsistency of SIMPLE-like Algorithms and an Entirely Consistent Update Technique - The CUT Algorithm.
- Author
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Jin, W. W., Tao, W. Q., He, Y. L., and Li, Z. Y.
- Subjects
- *
ALGORITHMS , *SPEED , *PRESSURE , *MOMENTUM (Mechanics) , *HEAT transfer - Abstract
The inconsistency of the second hypothesis of the SIMPLE-like algorithms is analyzed and a remedy - the Consistent Update Technique (CUT algorithm) - for velocity and pressure is proposed. In the CUT algorithm, at each iterative level the mass conservation condition is satisfied implicitly while the momentum equation is satisfied explicitly. In CUT algorithm, a modified equation for the explicit-velocity is suggested, and an adjustable coefficient is introduced. Four 2-D fluid flow and heat transfer problems are solved numerically by both the CUT and SIMPLER algorithms under the same other conditions. Comparisons of CPU time are made and it is found that for the four examples studied, the CUT can at least reduce CPU time by 15-63% with much better robustness. [ABSTRACT FROM AUTHOR]
- Published
- 2008
- Full Text
- View/download PDF
32. Use of High-Resolution Satellite Observations to Evaluate Cloud and Precipitation Statistics from Cloud-Resolving Model Simulations. Part I: South China Sea Monsoon Experiment.
- Author
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Zhou, Y. P., Tao, W.-K., Hou, A. Y., Olson, W. S., Shie, C.-L., Lau, K.-M., Chou, M.-D., Lin, X., and Grecu, M.
- Subjects
- *
CLOUD dynamics , *PRECIPITATION anomalies , *RAINFALL simulators , *ATMOSPHERIC circulation , *BAROCLINICITY , *METEOROLOGICAL satellites , *SNOW measurement , *PHYSICAL sciences research - Abstract
Cloud and precipitation simulated using the three-dimensional (3D) Goddard Cumulus Ensemble (GCE) model are compared to Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) and Precipitation Radar (PR) rainfall measurements and Clouds and the Earth’s Radiant Energy System (CERES) single scanner footprint (SSF) radiation and cloud retrievals. Both the model simulation and retrieved parameters are based upon observations made during the South China Sea Monsoon Experiment (SCSMEX) field campaign. The model-simulated cloud and rain systems are evaluated by systematically examining important parameters such as the surface rain rate, convective/stratiform percentage, rain profiles, cloud properties, and precipitation efficiency. It is demonstrated that the GCE model is capable of simulating major convective system development and reproduces the total surface rainfall amount as compared to rainfall estimated from the SCSMEX sounding network. The model yields a slightly higher total convective rain/stratiform rain ratio than the TMI and PR observations. The GCE rainfall spectrum exhibits a greater contribution from heavy rains than those estimated from PR or TMI observations. In addition, the GCE simulation produces much greater amounts of snow and graupel than the TRMM retrievals. The model’s precipitation efficiency of convective rain is close to the observations, but the precipitation efficiency of stratiform rain is much lower than the observations because of large amounts of slowly falling simulated snow and graupel. Compared to observations, the GCE produces more compact areas of intense convection and less anvil cloud, which are consistent with a smaller total cloud fraction and larger domain-averaged outgoing longwave radiation. [ABSTRACT FROM AUTHOR]
- Published
- 2007
- Full Text
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33. Blending activity and participation sub-domains of the ICF.
- Author
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Jette AM, Tao W, and Haley SM
- Abstract
Objective. The objective of the study was to test the supposition that distinct Activity and Participation sub-domains of the International Classification of Functioning, Disability, and Health (ICF) could be identified using physical function questionnaire items drawn from the Activity and Participation Measures for Post Acute Care. Design. A cross-sectional survey design was employed. Subjects. The sample consisted of 272 patients who had received post acute care across inpatient and community care settings during the previous year. Methods. Exploratory factor analysis with oblique rotation was used to identify interpretable dimensions underlying 83 physical functioning questionnaire items. Results. Factor analysis findings revealed five distinct ICF conceptual sub-domains that explained 61% of the total variance of the data, with root mean square residual equal to 0.089. These domains were labeled: (i) Daily activity, (ii) Applied cognitive, (iii) Role participation, (iv) Mobility, and (v) Social participation. These five factors were correlated to varying degrees and achieved acceptable levels of internal consistency with coefficient alphas from 0.59 - 0.93. Conclusion. These analyses suggest that clear distinctions between Activity and Participation sub-domains of the ICF could not be identified in a sample of adults who had recently received post acute care. We believe this is important evidence of the ability to measure blended Activity and Participation sub-domains that cut across distinct and interpretable areas of life functioning. [ABSTRACT FROM AUTHOR]
- Published
- 2007
- Full Text
- View/download PDF
34. The Influence of Strip Location on the Pressure Drop and Heat Transfer Performance of a Slotted Fin.
- Author
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Tao, W. Q., Cheng, Y. P., and Lee, T. S.
- Subjects
- *
HEAT transfer , *PRESSURE , *HEAT resistant materials , *ENERGY transfer , *QUALITATIVE research - Abstract
In this article, a numerical study is conducted to predict the air-side heat transfer and pressure drop characteristics of slit fin-and-tube heat transfer surfaces. A three-dimensional steady laminar model is applied, and the heat conduction in the fins is also considered. Five types of slit fins, named slit 1, slit 2, slit 3, slit 4, and slit 5, are investigated, which have the same global geometry dimensions and the same numbers of strips on the fin surfaces. The only difference among the five slit fins lies in the strip arrangement. Slit 1 has all the strips located in the front part of the fin surface, then, following the order from slit 1 to slit 5, the strip number in the front part decreases and, correspondingly, the strip number in the rear part increases, so that all the strips of slit 5 are located in the rear part. Furthermore, slit 1 and slit 5, slit 2 and slit 4, have a symmetrical strip arrangement along the flow direction. The numerical results show that, following the order from slit 1 and slit 5, the heat transfer rate increases at first, reaching a maximum value at slit 3, which has the strip arrangement of "front coarse and rear dense"; after that, it begins to decrease, as does the fin efficiency. Although they have the symmetrical strip arrangement along the flow direction, slit 5 has 7% more Nusselt number than slit 1, and slit 4 also has 7% more Nusselt number than slit 2, which shows that strip arrangement in the rear part is more effective than that in the front part. Then the difference of heat transfer performance among five slit fins is analyzed from the viewpoint of thermal resistance, which shows that when the thermal resistances in the front and rear parts are nearly identical, the optimum enhanced heat transfer fin can be obtained. This quantitative rule, in conjunction with the previously published qualitative principle of "front sparse and rear dense," can give both quantitative and qualitative guides to the design of efficient slotted fin surfaces. Finally, the influence of fin material on the performance of enhanced-heat-transfer fins is discussed. [ABSTRACT FROM AUTHOR]
- Published
- 2007
- Full Text
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35. Design of High-Order Difference Scheme and Analysis of Solution Characteristics - Part I: General Formulation of High-Order Difference Schemes and Analysis of Convective Stability.
- Author
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Jin, W. W. and Tao, W. Q.
- Subjects
- *
POWER (Mechanics) , *NUMERICAL analysis , *HEAT transfer , *MULTIPHASE flow , *NUMERICAL calculations , *MATHEMATICAL models - Abstract
In this article, a general design method of second-order difference schemes is presented. By this method, we can easily design any second-order or higher-order difference scheme instead of using complex Lagrange interpolation methods or spline functions. Moreover, it is proved that all existing second-order difference schemes in numerical heat transfer fit this general design style. In addition, based on this general style of second-order scheme, the general style of a second-order absolutely stable scheme is deduced, and the stability definitions are shown in a normalized variable diagram. Finally, through studying the solution characteristics of 14 second-order difference schemes, it is found that, to second order precise, absolutely stable schemes obtained from the general method can achieve good convergence even when the grid Pelect number reaches 100,000. However, at the same time, the false diffusion of the scheme tends to increase along with the increasing value of ai (coefficient in the interface variable definition). [ABSTRACT FROM AUTHOR]
- Published
- 2007
- Full Text
- View/download PDF
36. Design of High-Order Difference Scheme and Analysis of Solution Characteristics - Part II: A Kind of Third-Order Difference Scheme and New Scheme Design Theory.
- Author
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Jin, W. W. and Tao, W. Q.
- Subjects
- *
POWER (Mechanics) , *NUMERICAL analysis , *HEAT transfer , *MULTIPHASE flow , *NUMERICAL calculations - Abstract
In this Part II, on the basis of the general style design of second-order difference scheme and the analysis of the absolutely stable scheme proposed in Part I, the companion article, the general design method of any high-order difference scheme is proposed. Based on this method, a new kind of third-order difference scheme including 17 different variants is constructed, which uses the same grid points as existing second-order difference schemes but is different from them in that the grids are chosen symmetrically from two sides of the interface. Because they have the same matrix style created by the same grid plots of the discretization equation, these third-order schemes require the same CPU time and memory as the second-order schemes; however, this kind of symmetrical third-order difference scheme will keep the consistency between the false diffusion and the stability, and the stability of the scheme is better than that of the existing biased second-order scheme. Further research shows that under the conditions of matrix style and computer memory, the scheme constituted by symmetrically numbered grids from two sides of the interface with odd order of accuracy can maintain consistency between numerical accuracy and stability better than any kind of scheme designed according to the "upwind" idea. Based on this understanding, a new scheme design theory called symmetric and odd-order accuracy scheme design theory is proposed. [ABSTRACT FROM AUTHOR]
- Published
- 2007
- Full Text
- View/download PDF
37. SIMULATING TWO- AND THREE-DIMENSIONAL MICROFLOWS BY THE LATTICE BOLTZMANN METHOD WITH KINETIC BOUNDARY CONDITIONS.
- Author
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TANG, G. H., TAO, W. Q., and HE, Y. L.
- Subjects
- *
TRANSPORT theory , *GAS flow , *GAS dynamics , *DIFFERENTIAL equations , *NUMERICAL analysis , *SIMULATION methods & models - Abstract
An entropic lattice Boltzmann model for gaseous slip flow in microchannels is presented. We relate the Knudsen number with the relaxation time in the lattice Boltzmann evolution equation from the gas kinetic theory. The slip velocity taking the momentum accommodation coefficient into account at the solid boundaries is obtained with kinetic boundary conditions. The two-dimensional micro-Poiseuille flow, microflow over a backward-facing step, micro-lid-driven cavity flow, and three-dimensional microflow are simulated using the present model. Numerical tests show that the results of the present lattice Boltzmann method together with the boundary scheme are in good agreement with the analytical solutions and numerical simulations by the finite volume method. [ABSTRACT FROM AUTHOR]
- Published
- 2007
- Full Text
- View/download PDF
38. Improving Simulations of Convective Systems from TRMM LBA: Easterly and Westerly Regimes.
- Author
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Lang, S., Tao, W.-K., Cifelli, R., Olson, W., Halverson, J., Rutledge, S., and Simpson, J.
- Subjects
- *
RAINFALL , *CONVECTION (Meteorology) , *MICROPHYSICS , *ATMOSPHERIC circulation , *HEAT convection , *METEOROLOGICAL precipitation , *HYDROMETEOROLOGY , *METEOROLOGY - Abstract
The 3D Goddard Cumulus Ensemble model is used to simulate two convective events observed during the Tropical Rainfall Measuring Mission Large-Scale Biosphere–Atmosphere (TRMM LBA) experiment in Brazil. These two events epitomized the type of convective systems that formed in two distinctly different environments observed during TRMM LBA. The 26 January 1999 squall line formed within a sheared low-level easterly wind flow. On 23 February 1999, convection developed in weak low-level westerly flow, resulting in weakly organized, less intense convection. Initial simulations captured the basic organization and intensity of each event. However, improvements to the model resolution and microphysics produced better simulations as compared to observations. More realistic diurnal convective growth was achieved by lowering the horizontal grid spacing from 1000 to 250 m. This produced a gradual transition from shallow to deep convection that occurred over a span of hours as opposed to an abrupt appearance of deep convection. Eliminating the dry growth of graupel in the bulk microphysics scheme effectively removed the unrealistic presence of high-density ice in the simulated anvil. However, comparisons with radar reflectivity data using contoured-frequency-with-altitude diagrams (CFADs) revealed that the resulting snow contents were too large. The excessive snow was reduced primarily by lowering the collection efficiency of cloud water by snow and resulted in further agreement with the radar observations. The transfer of cloud-sized particles to precipitation-sized ice appears to be too efficient in the original scheme. Overall, these changes to the microphysics lead to more realistic precipitation ice contents in the model. However, artifacts due to the inability of the one-moment scheme to allow for size sorting, such as excessive low-level rain evaporation, were also found but could not be resolved without moving to a two-moment or bin scheme. As a result, model rainfall histograms underestimated the occurrence of high rain rates compared to radar-based histograms. Nevertheless, the improved precipitation-sized ice signature in the model simulations should lead to better latent heating retrievals as a result of both better convective–stratiform separation within the model as well as more physically realistic hydrometeor structures for radiance calculations. [ABSTRACT FROM AUTHOR]
- Published
- 2007
- Full Text
- View/download PDF
39. A Study of the Response of Deep Tropical Clouds to Large-Scale Thermodynamic Forcings. Part II: Sensitivities to Microphysics, Radiation, and Surface Fluxes.
- Author
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Johnson, D. E., Tao, W.-K., and Simpson, J.
- Subjects
- *
CLOUDS , *METEOROLOGY , *THERMODYNAMICS , *ATMOSPHERIC boundary layer , *METEOROLOGICAL precipitation , *TROPOSPHERE , *ATMOSPHERIC physics , *CLOUD physics , *MOISTURE - Abstract
The Goddard Cumulus Ensemble (GCE) model is used to examine the sensitivities of multiday 2D simulations of deep tropical convection to surface fluxes, interactive radiation, and ice microphysical processes. The simulations incorporate large-scale temperature, moisture, and momentum forcings, from the Tropical Ocean Global Atmosphere Coupled Ocean–Atmosphere Response Experiment (TOGA COARE) for the period 19–27 December 1992. This study shows that, when surface fluxes are eliminated, the mean simulated atmosphere is much cooler and drier, convection and CAPE are much weaker, precipitation is less, and low-level to midlevel cloudiness is much greater. Surface fluxes using the TOGA COARE flux algorithm are weaker than with the aerodynamic formulation, but closer to the observed fluxes. In addition, trends similar to those noted above for the case without surface fluxes are produced for the TOGA COARE flux case, albeit to a much lesser extent. The elimination of shortwave and longwave radiation is found to have only minimal effects on the mean thermodynamics, convection, and precipitation. However, exclusion of radiation in the model does have a significant impact on cloud temperatures and structure above 200 mb. The removal of ice microphysical processes produces major changes in the structure of the clouds. Much of the liquid water is transported to the upper levels of the troposphere and evaporates, resulting in less mean total surface precipitation. The precipitation primarily occurs in regions of narrow, but intense, convective rainfall bands. The elimination of melting processes (diabatic cooling and conversions to rain) leads to greater (ice) hydrometeor mass below the 0°C level and reduced latent cooling. This, along with weaker vertical cloud mass fluxes, produces a much warmer and moister boundary layer, and a greater mean CAPE. Finally, the elimination of the graupel species has only a small impact on mean total precipitation, thermodynamics, and dynamics of the simulation, but does produce much greater snow mass just above the melting layer. [ABSTRACT FROM AUTHOR]
- Published
- 2007
- Full Text
- View/download PDF
40. Protective effects of mycelia of Antrodia camphorata and Armillariella tabescens in submerged culture against ethanol-induced hepatic toxicity in rats.
- Author
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Lu Z, Tao W, Zou X, Fu H, and Ao Z
- Abstract
The hepatoprotective effects of the mycelia of Antrodia camphorata and Armillariella tabescens were evaluated in vivo using acute ethanol-intoxicated rats as an experimental model. Animals were orally treated with Antrodia camphorata (0.5 or 1.0g/kgb.w.) or Armillariella tabescens (0.5 or 1.0g/kgb.w.) for 10 days whereas controls received vehicle only. At the end of the experimental 10-day period, the animals were administered by gavage with an acute ethanol dose of 5.0g/kgb.w. diluted in deionized water (6:4, v/v) and sacrificed at 18h after ethanol administration. The degree of protection was measured by using biochemical parameters like serum transaminases (AST and ALT), alkaline phosphatase (ALP), bilirubin. Meanwhile, the histopathological studies were carried out to support the above parameters. Administration of Antrodia camphorata or Armillariella tabescens markedly prevented ethanol-induced elevation of levels of serum AST, ALT, ALP, and bilirubin comparable with standard drug silymarin. [ABSTRACT FROM AUTHOR]
- Published
- 2007
41. An Improved Numerical Scheme for the SIMPLER Method on NonOrthogonal Curvilinear Coordinates: SIMPLERM.
- Author
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Qu, Z. G., Tao, W. Q., and He, Y. L.
- Subjects
- *
CURVILINEAR coordinates , *GRIDS (Cartography) , *FLUID dynamics , *SPEED , *PRESSURE , *HEAT transfer - Abstract
In this article, an improved numerical algorithm named SIMPLERM is proposed for incompressible fluid flow computations on the nonstaggered and nonorthogonal curvilinear grid system. In the proposed algorithm, the contravariant velocities are chosen as the cell face velocities and the Cartesian components as the primary variables. The velocity under-relaxation factor is incorporated into the momentum interpolation, and special treatment is adopted to avoid the underrelaxation factor dependence of the velocity solution. In addition, a 1 - δ pressure difference is introduced into the interfacial contravariant velocity determination. Compared with the existing implementation methods of the SIMPLE family on non-staggered and nonorthogonal grids, the SIMPLERM algorithm can guarantee the coupling between velocity and pressure, underrelaxation independence of the solution, and satisfaction of the conservation law, while still possessing sufficient robustness. [ABSTRACT FROM AUTHOR]
- Published
- 2007
- Full Text
- View/download PDF
42. RETRIEVAL OF LATENT HEATING FROM TRMM MEASUREMENTS.
- Author
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TAO, W.-K., SMITH, E. A ., ADLER, R. F., HADDAD, Z. S., Hou, A. Y., IGUCHI, T., KAKAR, R., KRISHNAMURTI, T. N., KUMMEROW, C. D., LANG, S., MENEGHINI, R., NAKAMURA, K., NAKAZAWA, T., OKAMOTO, K., OLSON, W. S., SATOH, S., SHIGE, S., SIMPSON, J., TAKAYABU, Y., and TRIPOLI, G. J.
- Subjects
- *
LATENT heat release in the atmosphere , *SATELLITE meteorology , *ATMOSPHERIC thermodynamics , *DYNAMIC meteorology , *METEOROLOGICAL precipitation , *RAINFALL , *ARTIFICIAL satellites , *METEOROLOGICAL satellites - Abstract
The article describes how latent heating (LH) profiles are derived from satellite precipitation rate retrievals made with the Tropical Rainfall Measuring Mission (TRMM) satellite measurements. Latent heating is the principal source of energy in the propagation, vertical structure, creation, and growth of tropical waves. The TRMM satellite is an international cooperation effort in rainfall research involving the U.S. National Aeronautics and Space Administration (NASA) and Japan's Aerospace Exploration Agency (JAXA).
- Published
- 2006
- Full Text
- View/download PDF
43. OPTIMUM DESIGN OF TWO-ROW SLOTTED FIN SURFACE WITH X-SHAPE STRIP ARRANGEMENT POSITIONED BY "FRONT COARSE AND REAR DENSE" PRINCIPLE, PART I: RESULTS AND DISCUSSION.
- Author
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Tao, W. Q., Jin, W. W., He, Y. L., Qu, Z. G., and Zhang, C. C.
- Subjects
- *
FLUID dynamics , *HEAT transfer , *AIR flow , *STRUCTURAL optimization , *TUBES , *LAMINAR flow , *MATHEMATICAL models , *NUMERICAL analysis - Abstract
In this article, a comprehensive numerical investigation of the air-side fluid flow and heat transfer characteristics in a two-row finned-tube heat exchanger is conducted with a three-dimensional laminar conjugate model. Three groups including 15 types of slotted fin surface are studied. In the first group the strips are arranged in X shape with the principle of “front coarse and rear dense,” and the number of strips varies from three to six. The first series of the second group is formed by changing the strip length of slit fin 3 in the first group, and the second series of this group is formed by changing the strip lengths of slit 1 and slit 2 in the first group. The third group is formed by splitting one strip of slit fin 2 into two. The three groups are designed in order to enhance the values of j/f at the same Reynolds number and enhance the heat transfer at identical pumping power. The physical model/mathematical formulation and numerical methods are described. The authors' numerical experiences show that for the convergence criteria, apart from the relative variation of the key parameters, their variation trends versus some independent variables should also be taken into account. Reliable numerical solutions for the problem studied should possess consistency and smoothness in their variation trends. In Part II of this article, the specific flow and heat transfer characteristics of the 15 slotted fin surfaces and comparisons with a plain plate surface will be presented in detail. [ABSTRACT FROM AUTHOR]
- Published
- 2006
- Full Text
- View/download PDF
44. Quantitative phosphoproteome analysis using a dendrimer conjugation chemistry and tandem mass spectrometry.
- Author
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Tao, W. Andy, Wollscheid, Bernd, O'Brien, Robert, Eng, Jimmy K., Xiao-jun Li, Bodenmiller, Bernd, Watts, Julian D., Hood, Leroy, and Aebersold, Ruedi
- Subjects
- *
PROTEINS , *PHOSPHORYLATION , *PHOSPHOPROTEINS , *T cell receptors , *DENDRIMERS , *MASS spectrometry - Abstract
We present a robust and general method for the identification and relative quantification of phosphorylation sites in complex protein mixtures. It is based on a new chemical derivatization strategy using a dendrimer as a soluble polymer support and tandem mass spectrometry (MS/MS). In a single step, phosphorylated peptides are covalently conjugated to a dendrimer in a reaction catalyzed by carbodiimide and imidazole. Modified phosphopeptides are released from the dendrimer via acid hydrolysis and analyzed by MS/MS. When coupled with an initial antiphosphotyrosine protein immunoprecipitation step and stable-isotope labeling, in a single experiment, we identified all known tyrosine phosphorylation sites within the immunoreceptor tyrosine-based activation motifs (ITAM) of the T-cell receptor (TCR) CD3 chains, and previously unknown phosphorylation sites on total 97 tyrosine phosphoproteins and their interacting partners in human T cells. The dynamic changes in phosphorylation were quantified in these proteins. [ABSTRACT FROM AUTHOR]
- Published
- 2005
- Full Text
- View/download PDF
45. Lattice Boltzmann method for gaseous microflows using kinetic theory boundary conditions.
- Author
-
Tang, G. H., Tao, W. Q., and He, Y. L.
- Subjects
- *
KINETIC theory of gases , *BOUNDARY value problems , *DIFFERENTIAL equations , *NUMERICAL analysis , *MATHEMATICAL models , *MOLECULAR theory - Abstract
The lattice Boltzmann method is developed to study gaseous slip flow in microchannels. An approach relating the Knudsen number with the relaxation time in the lattice Boltzmann evolution equation is proposed by using gas kinetic equation resulting from the Bhatnagar–Gross–Krook collision model. The slip velocity at the solid boundaries is obtained with kinetic theory boundary conditions. The two-dimensional micro-Couette flow, micro-Poiseuille flow, and micro-lid-driven cavity flow are simulated using the present model. It is found that the numerical results agree well with available analytical and benchmark solutions. [ABSTRACT FROM AUTHOR]
- Published
- 2005
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46. The Atmospheric Energy Budget and Large-Scale Precipitation Efficiency of Convective Systems during TOGA COARE, GATE, SCSMEX, and ARM: Cloud-Resolving Model Simulations.
- Author
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Tao, W.-K., Johnson, D., Shie, C.-L., and Simpson, J.
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- *
METEOROLOGICAL precipitation , *CLOUDS , *SIMULATION methods & models , *MODELS & modelmaking , *ATMOSPHERIC physics , *CLIMATOLOGY - Abstract
A two-dimensional version of the Goddard Cumulus Ensemble (GCE) model is used to simulate convective systems that developed in various geographic locations (east Atlantic, west Pacific, South China Sea, and Great Plains in the United States). Observed large-scale advective tendencies for potential temperature, water vapor mixing ratio, and horizontal momentum derived from field campaigns are used as the main forcing. The atmospheric temperature and water vapor budgets from the model results show that the two largest terms are net condensation (heating/drying) and imposed large-scale forcing (cooling/moistening) for tropical oceanic cases though not for midlatitude continental cases. These two terms are opposite in sign, however, and are not the dominant terms in the moist static energy budget. The balance between net radiation, surface latent heat flux, and net condensational heating vary in these tropical cases, however. For cloud systems that developed over the South China Sea and eastern Atlantic, net radiation (cooling) is not negligible in the temperature budget; it is as large as 20% of the net condensation. However, shortwave heating and longwave cooling are in balance with each other for cloud systems over the west Pacific region such that the net radiation is very small. This is due to the thick anvil clouds simulated in the cloud systems over the Pacific region. The large-scale advection of moist static energy is negative, as a result of a larger absolute value of large-scale advection of sensible heat (cooling) compared to large-scale latent heat (moistening) advection in the Pacific and Atlantic cases. For three cloud systems that developed over a midlatitude continent, the net radiation and sensible and latent heat fluxes play a much more important role. This means that the accurate measurement of surface fluxes and radiation is crucial for simulating these midlatitude cases. The results showed that large-scale mean (multiday) precipitation efficiency (PE) varies from 24% to 31% (or 32% to 45% using a different definition of PE) between cloud systems from different geographic locations. The model results showed that there is no clear relationship between the PE and rainfall, the positive cloud condensation (condensation plus deposition), or the large-scale forcing. But, the model results suggest that cases with large, positive net condensation terms in the moist static energy budget tend to have a large PE. The PE and its relationship with relative humidity and the vertical shear of the horizontal wind are also examined using 6-hourly model data. The model results suggest that there is no clear relationship between the individual PE and total mass-weighted relative humidity or the middle- and upper-tropospheric moisture for each case. The model results suggest that for the west Pacific and east Atlantic cases, PE slightly decreases with increasing middle-tropospheric wind shear in low to moderate shear regimes. The correlation (based on the best polynomial fit) is quite weak however. No strong relationship between PE and wind shear was found for the South China Sea and cases over the United States. [ABSTRACT FROM AUTHOR]
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- 2004
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47. Three-Dimensional Numerical Simulation on Laminar Heat Transfer and Fluid Flow Characteristics of Strip Fin Surface With X-Arrangement of Strips.
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Qu, Z. G., Tao, W. Q., and He, Y. L.
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HEAT convection , *FINITE differences , *GEOMETRIC surfaces , *HEAT exchangers , *HEAT transfer , *NUMERICAL calculations , *ENERGY consumption , *SPEED , *TEMPERATURE inversions - Abstract
In this paper, a numerical investigation of air side performance of strip fin surface is presented. Three-dimensional numerical computation was made for a model of a two-row finned tube heat exchanger. The tube configuration is simulated with step-wise approximation, and the fin efficiency is also calculated with conjugated computation. Four types of fin surfaces were studied: A-the whole plain plate fin; B-the strip fin with strips located in the upstream part of the fin; C-the strip fin with strips located in the downstream part of the fin; and D-the strip fin with strips covering the whole fin surface. It is found that the strip fin with strips located in the downstream part of the fin surface (fin C) has higher heat transfer rate than that with strips in the upstream part (fin B) at the same conditions, while the pressure drop of fin C is a bit lower than that of fin B. A comprehensive performance comparison was conducted by using the goodness factor and the pumping power consumption per unit surface area. It is revealed that between the two strip fins the performance of fin C is better than fin B with same strip number. Detailed discussion is provided from the view point of synergy between velocity and temperature gradient. It is shown that the synergy between velocity and temperature field becomes worse in the downstream part of the fin surface, and it is this place that enhancement technique is highly needed. The strip location of fin C just fits this situation. The present numerical work provides useful information on where the enhancement element should be positioned. [ABSTRACT FROM AUTHOR]
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- 2004
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48. Reply.
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Lang, S., Tao, W.-K., Simpson, J., and Ferrier, B.
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LETTERS to the editor , *METEOROLOGICAL precipitation - Abstract
Presents a response by authors to a letter to the editor on their article "Modeling of Convective-Stratiform Precipitation Processes: Sensitivity to Partitioning Methods," that was published in the "Journal of Applied Meteorology."
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- 2004
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49. SDF-1a/CXCL12 enhances retroviral-mediated gene transfer into immature subsets of human and murine hematopoietic progenitor cells.
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Tao, W., Hangoc, G., Cooper, S., and Broxmeyer, H.E.
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GENETIC transduction , *GENETIC transformation , *HEMATOPOIETIC stem cells , *HEMATOPOIESIS , *RETROVIRUSES , *GENETICS - Abstract
Genetic modification of hematopoietic stem and progenitor cells has the potential to treat diseases affecting blood cells. Oncoretroviral vectors have been used for gene therapy; however, clinical success has been limited in part by low gene transfer efficiencies. We found that the presence of stromal-derived factor 1 (SDF-1a)/CXCL12 during retroviral transduction significantly enhanced, in a dose-dependent fashion, gene transfer into immature subsets of high proliferative human and murine hematopoietic progenitor cells. Murine mononuclear bone marrow cells and purified c-Kit+Lin- bone marrow cells were prestimulated and transduced with the bicistronic retroviral vector MIEG3 on Retronectin-coated surfaces in the presence and absence of SDF-1. SDF-1 enhanced gene transduction of murine bone marrow and c-Kit+Lin- cells by 35 and 29%, respectively. Moreover, SDF-1 enhanced transduction of progenitors in these populations by 121 and 107%, respectively. SDF-1 also enhanced transduction of human immature subsets of high proliferative progenitors present in either nonadherent mononuclear or CD34+ umbilical cord blood cells. Transduction of hematopoietic progenitors was further increased by preloading Retronectin-coated plates with retrovirus using low-speed centrifugation followed by increasing cell-virus interactions through brief centrifugation during the transduction procedure. These results may be of clinical relevance.Gene Therapy (2004) 11, 61-69. doi:10.1038/sj.gt.3302127 [ABSTRACT FROM AUTHOR]
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- 2004
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50. A NOVEL SEGREGATED ALGORITHM FOR INCOMPRESSIBLE FLUID FLOW AND HEAT TRANSFER PROBLEMS--CLEAR (COUPLED AND LINKED EQUATIONS ALGORITHM REVISED) PART II: APPLICATION EXAMPLES.
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Tao, W. Q., Qu, Z. G., and He, V. L.
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- *
ALGORITHMS , *FLUIDS , *HEAT transfer , *ENERGY transfer , *ITERATIVE methods (Mathematics) , *STOCHASTIC convergence - Abstract
In Part I of this article a novel algorithm, CLEAR, was introduced. In this article the relative performance of the CLEAR algorithm and the SIMPLER algorithm is evaluated for six incompressible fluid flow and heat transfer problems with constant property. The six examples cover three two-dimensional orthogonal coordinates. Comprehensive comparisons are made between the two algorithms on the subject of iteration number for obtaining a converged solution, and the consumed CPU time. It is found that CLEAR can appreciably enhance the convergence rate. For the six problems tested, the ratio of iteration numbers of CLEAR over that of SIMPLER ranges from 0.15 to 0.84, and the ratio of the CPU time from 0.19 to 0.92. [ABSTRACT FROM AUTHOR]
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- 2004
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