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Characterization of particle size and settling velocity of cohesive sediments affected by a neutral exopolymer

International Journal of Sediment Research 2012年第4期27卷 473-485页

作者： Xiao-ling TAN Guo-ping ZHANG Hang YIN Allen H.REED yoko furukawa Graduate Research Assistant Department of Civil ＆ Environmental EngineeringLouisiana State University Department of Civil & Environmental Engineering Louisiana State University Graduate Research Assistant Department of Civil & Environmental EngineeringLouisiana State University Research Scientist Seafloor Sciences BranchNaval Research LaboratoryStennis Space Center

In natural waters,exopolymers or extracellular polymeric substances(EPS) exuded by microorganisms interact with clay particles,resulting in the flocculation of clays and hence alteration to the properties of suspended cohesive *** investigate and further understand how neutral EPS affect cohesive sediment transport and the final sediment yield,an experimental study was conducted on laboratory-prepared clay and guar gum(used as an analog for neutral EPS) suspensions to characterize EPS-induced flocculation and the settling velocity of resultant *** different clays consisting of kaolinite,illite,Ca-montmorillonite,and Na-montmorillonite were studied to examine the influence of different layer charges on clay flocculation induced by neutral *** size was determined by a laser particle size analyzer,and settling velocity estimated by analyzing the time-series floc settling images captured by an optical *** indicate that neutral EPS promote clay-EPS flocculation for all four clays with the particle/floc size significantly increased from～0.1-60μm to as large as～600μ***' layer charge has a profound influence on the clay-EPS *** the same floc size,the settling velocity of clay-EPS flocs is typically smaller than that of pure clay flocs,which is attributed to the reduced density of flocs caused by the EPS. However,for flocs of the same composition(*** clay or hybrid clay-EPS mixture),the settling velocity increases with *** fractal dimension of these clay-EPS flocs estimated from settling velocity ranges from 1.39 to 1.47,which are smaller than that of pure clay flocs,indicating that these flocs are less compacted than the pure clay flocs.

关键词： Clay Exopolymer Flocculation Fractal dimension Particle size Settling velocity

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Dynamic properties of a flexible metal-organic framework exhibiting a unique"picture frame"-like crystal morphology

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Nano Research 2021年第2期14卷 432-437页

作者： Kenji Sumida Nao Horike Shuhei furukawa Institute for Integrated Cell-Material Sciences(WPI-iCeMS) Kyoto UniversityYoshidaSakyo-kuKyoto 606-8501Japan Centre for Advanced Nanomaterials School of Physical SciencesUniversity of AdelaideSA 5005Australia

The precise control of the crystal morphology of metal-organic frameworks(MOFs)enables optimization of its adsorptive properties,as well as enables better integration within functional ***,the influence of such modifications on the dynamic properties of flexible MOFs is poorly understood Here,we report the synthesis of a series of Cu_(2)(bdc)_(2)(bpy)(bdc^(2-)=1,4-benzenedicarboxylate;bpy=4,4,-bipyridine)crystals having an unusual picture frame-like morphology that results from a restriction in the quantity of bpy pillars added to the reaction mixture during the intercalation of the Cu_(2)(bdc)_(2)(MeOH)_(2)*** width of the frames is found to correlate with the quantity of bpy,and importantly,causes the dynamic properties of the resulting Cu_(2)(bdc)_(2)(bpy)material to vary between rigid,elastic,and shape memory *** all,the results demonstrate the potential for the properties of MOFs to be optimized via subtle manipulations in the crystal morphology rather than changes in the overall material composition.

关键词： metal-organic frameworks morphology control framework flexibility shape-memory effect gas sorption

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Performance Test and Flow Measurement of Contra-Rotating Axial Flow Pump

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Journal of Thermal Science 2007年第1期16卷 7-13页

作者： Akinori furukawa Toru Shigemitsu Satoshi Watanabe Division of Mechanical Engineering Science Kyushu University744 MotookaNishi-kuFukuoka 819-0395JAPAN

An application of contra-rotating rotors has been proposed against a demand for developing higher specific speed axial flow pump. In the present paper, the advantage and disadvantage of using contra-rotating rotors are described in comparison with conventional type of rotor-stator, based on theoretical and experimental investigations. The advantages are as follows：（1） The pump is inherently designed as smaller sized and at lower rotational speed. （2） A stable head-characteristic curve for flow rate with negative slope appears. （3） As the rear rotor rotational speed is varied as independent control of front rotor, the wider range of high performance operation is obtained by rear rotor speed control in addition to front rotor speed control. The disadvantages are as follows：（1） The structure of double shaft system becomes complex. （2） The pump performance is inferior at over flow rate as the rear rotor loading is weakened. （3） The blade rows interaction from rear rotor to front rotor more strongly appears. Then the rear rotor design is a key to achieve higher pump performance. Some methods to overcome these disadvantages will be discussed in more details toward wider usage of contra-rotating axial flow pump in various industrial fields.

关键词： axial flow pump contra-rotating rotors multiphase flow rotational speed control blade rows interaction

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CONTRIBUTION OF MACROSCOPIC DIMENSION EFFECT TO PIEZOELFCTRICITY IN POLYVINYLIDENE FLUORIDE

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Chinese Journal of Polymer Science 1987年第4期5卷 292-297页

作者：闻建勋,TAKEO furukawa Shanghai Institute of Organic Chemistry Academia Sinica Shanghai The Institute of Physical and Chemical Research Japan

In this paper, we have studied the piezoelectricity in the poled uniaxially drawn polyvinylidene fluoride. The piezoelectric constants d31, d32, d33αand Young's moduli 1/s11 and 1/s22have been determined as a function of the remanent polarization Pr. The piezoelectric constants of the samples show a strong in-plane anisotropy. Such an anisotropy is mostly attributable to different Poisson's ratio. It is found that the piezoelectric activity mainly arises from macroscopic dimensional change.

关键词： Piezoelectricity Pyroelectricity Polyvinylidene fluoride.

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A case of congenital aneurysm of the ulnar artery of the palm

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Plastic and Aesthetic Research 2020年第1期7卷 17-23页

作者： yoko Kishi Department of Pediatric Surgery Dokkyo Medical University Saitama Medical CenterSaitama 343-8555Japan.

Congenital aneurysms of the palm are uncommon in the pediatric population compared to aneurysms in adults.A seven-month-old boy presented with a true aneurysm of the ulnar artery with reconstruction with surgical excision and end-to-end microvasculer anastomosis using a superficial vein of the dorsal *** our knowledge,there have been only 15 reports of congenital aneurysms of the palm.

关键词： Congenital aneurysm of the palm ulnar artery microvascular reconstruction

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Improvement of aerodynamic stability of suspension bridges with H-shaped simplified stiffening girder

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Frontiers of Structural and Civil Engineering 2016年第1期10卷 93-102页

作者： Hiroshi KATSUCHI Hitoshi YAMADA Mayuko NISHIO yoko OKAZAKI Department of Civil Engineering Yokohama National University Yokohama 240-8501 Japan

Wind-tunnel study on the improvement of aerodynamic stability of simplified suspension-bridge girder structures was conducted with using a 1/40-scaled section model. Objective of the study is the development of an economically superior suspension bridge with 500-1,000 m center span length. The wind-tunnel test showed that an edge-girder type cross section exhibited large amplitude torsional vortex-induced vibration as well as torsional flutter at a low wind speed. Accordingly, aerodynamic countermeasures of open grating deck and triangular fating, and structural countermeasures of center stay, diagonal bracing and mass increase were tried to improve the aerodynamic stability. Finally, feasibility of the best combination to a full-scale bridge was examined by structural analysis.

关键词： suspension bridge aerodynamics simplified girder wind-tunnel test

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Carbonation of low heat portland cement paste precured in water for different time

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Journal of University of Science and Technology Beijing 2007年第2期14卷 178-184页

作者： Deping Chen Etsuo Sakai Masaki Daimon yoko Ohba Civil and Environmental Engineering School University of Science and Technology Beijing Beijing 100083 China Graduate School of Science and Engineering Tokyo Institute of Technology Tokyo 152-8552 Japan

The carbonation technique was applied to accelerate the hydration of low heat portland cement （LHC）. Before carbonation, the demoulded pastes were precured in water for 0, 2, 7, and 21 d, respectively. The results show that precuring time in water strongly influences the carbonation process. The phenolphthalein test indicates that the paste precured in water for a shorter time is more quickly carbonated than that for a longer time. The content of calcium hydroxide increases with increasing the precuring time in water, whereas, the amount of absorbed carbon dioxide changes contrarily. Scanning electron microscope （SEM） observation shows that portlandite always fills up big air bubbles in the paste during precuring in water, and the mercury intrusion porosimetry （MIP） results show that there are less large capillary pores in the paste precured in water for a longer time. It is found that the paste without precuring in water has more carbon dioxide absorption during curing in carbon dioxide atmosphere, and its total pore volume decreases remarkably with an increase in the carbonation time than that precured in water. X-ray diffraction （XRD） and Brunauer-Emmett-Teller （BET） surface area analyses indicate that the carbonate products are vaterite and calcite; CxSHy formed from carbonation has low BET surface area in comparison with that of C-S-H formed from curing in water.

关键词： carbonation carbon dioxide absorption vaterite BET surface area pore size distribution

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STUDIES ON THE CHAIN STRUCTURAL EFFECT OF PVDF AND VDF (52)/TrFE(48) COPOLYMER BY MEANS OF THE METHOD OF DIELECTRIC RELAXATION

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Chinese Journal of Polymer Science 1994年第1期12卷 12-21页

作者：张兴元 furukawa Takeo Department of Materials Science and Engineering University of Science and Technology of China Hefei 230026 Department of Chemistry Science University of Tokyo Japan

Through improvements on a fully commercial and automatic system measuring frequency andtemperature spectra of the complex elastic, dielectric, and piezoelectric constants of polymerfilms, the precision for measuring complex dielectric constants achieved 2‰ from original 1%.The complex dielectric constants of PVDF, VDF （95 ）/VF （5）, VDF （52）/TrFE （48） and VDF（47. 5）/TrFE（47. 5）/HeFP （5） over a range of-120-140℃, 10-2-10;Hz were measured bythe described system. The diminution of chain regularity due to 5mol% vinyl fluoride in the chainof PVDF led to disappearing of α-relaxation and increase in T;（3℃） of VDF （95）/VF （5）.Because of the spatial impediment of 5mol% HeFP in copolymer chain, the Curie point of VDF（52）/TrFE（48） decreased by 30℃ and T;by 3℃. The behavior of dielectric relaxation indicatedthat 5mol% vinyl fluoride and HeFP made the relaxation strength of noncrystalline regionreduced, the activation energy of local relaxation increased and the relaxation time prolonged respectively.

关键词： Polyvinylidene fluoride VDF(52)/TrFE(48) Chain structure effect Dielectric relaxation

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Dielectric Relaxations in Ferroelectric Copolymer VDF(73)/TrFE(27)

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Journal of Materials Science & Technology 1995年第1期11卷 31-37页

作者： ZHANG, XY furukawa, TK SCI UNIV TOKYO DEPT CHEMTOKYO 162JAPAN

The characteristics of molecular motion of ferroelectric copolymer VDF(73)/TrFE(27) have been investigated by means of dielectric relaxation. With the rise in crystallinity, the Curie point decreases and the dielectric constant increases in the region of ferroelectric-to-paraelectric phase transition. The frequency spectra of the copolymer below room temperature consist of low-frequency component ascribed to the micro-Brownian motions of molecular segments in the noncrystalline regions and high-frequency component associated with the local motions of small-scale segments. By using the fitting results with one or two Cole-Cole functions, and calculating with WLF equation acid Arrhenius formula,the glass transition temperature and the activation energy of local relaxation are obtained. the distribution of relaxation time in the molten and ferroelectric phases is located at a Same line, acid complies with Arrhenius rule, which suggests that the elementary motions are of same type for molecular motions provided by the high-temperature process and the low-temperature local mode process.

关键词： Dielectric Relaxations in Ferroelectric Copolymer VDF Figure TrFE

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WORK/LIFE COMMUNITY BY TELEWORK—POSSIBILITIES AND ISSUES IN THE CASE OF LOMA LINDA

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Journal of Green Building 2008年第2期3卷 128-139页

作者： yoko Kawai Penguin Environmental Design L.L.C.in HamdenConnecticut

This paper suggests telework, and work/life community created by it, as potential design tools for the sustainability oflocal communities, and investigates their possibility and issues through a case study of Loma Linda Connected CommunityProgram (LLCCP).A new work/life style enabled by information communication technology (ICT), often called telework, is expandingin the U.S. The environmental impact which this gives on community scale has been neglected. Yet, since teleworkcan give the area economic advancement without huge development, make mixed-use zoning plausible, and grantssense of community, it could bring physical, economic and social sustainability to local ***, as an example of emerging municipal ICT deployment programs, was examined on two levels;i.e. levelof urban policy and of urban design. It was revealed that LLCCP, as an urban policy, has a good potential to createICT-served work/life community, thus to contribute to the smart growth of the city. It does so by promoting new businessesyet small/home ones only, and developing new neighborhoods yet ICT-served work/life communities only. Itslink to regional plans and to the building code which ensures the connectivity in entire city elevate its *** paper also pointed out that city’s urban design strategies are not yet supporting LLCCP toward its goal. Itlacks coordination with teleworkers’ life style, and with spatial system for the entire city. A current design proposaloverlooks teleworkers’ driving habits and their specifi c needs to the types of retails/business-services, for example. Theresult implies that the use of telework in creating sustainable community may have started to be recognized on urbanpolicy level, but that urban/architectural design for it is still behind to be developed.

关键词： sustainability telework information communication technology urban policy urban design

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