WorldWideScience

Sample records for unit cell thickness

  1. Exfoliation of natural van der Waals heterostructures to a single unit cell thickness

    Science.gov (United States)

    Velický, Matěj; Toth, Peter S.; Rakowski, Alexander M.; Rooney, Aidan P.; Kozikov, Aleksey; Woods, Colin R.; Mishchenko, Artem; Fumagalli, Laura; Yin, Jun; Zólyomi, Viktor; Georgiou, Thanasis; Haigh, Sarah J.; Novoselov, Kostya S.; Dryfe, Robert A. W.

    2017-02-01

    Weak interlayer interactions in van der Waals crystals facilitate their mechanical exfoliation to monolayer and few-layer two-dimensional materials, which often exhibit striking physical phenomena absent in their bulk form. Here we utilize mechanical exfoliation to produce a two-dimensional form of a mineral franckeite and show that the phase segregation of chemical species into discrete layers at the sub-nanometre scale facilitates franckeite's layered structure and basal cleavage down to a single unit cell thickness. This behaviour is likely to be common in a wider family of complex minerals and could be exploited for a single-step synthesis of van der Waals heterostructures, as an alternative to artificial stacking of individual two-dimensional crystals. We demonstrate p-type electrical conductivity and remarkable electrochemical properties of the exfoliated crystals, showing promise for a range of applications, and use the density functional theory calculations of franckeite's electronic band structure to rationalize the experimental results.

  2. Surface and Interface Properties of 10–12 Unit Cells Thick Sputter Deposited Epitaxial CeO2 Films

    Directory of Open Access Journals (Sweden)

    L. V. Saraf

    2008-01-01

    Full Text Available Ultrathin and continuous epitaxial films with relaxed lattice strain can potentially maintain more of its bulk physical and chemical properties and are useful as buffer layers. We study surface, interface, and microstructural properties of ultrathin (∼10–12 unit cells thick epitaxial ceria films grown on single crystal YSZ substrates. The out-of -plane and in-plane lattice parameters indicate relaxation in the continuous film due to misfit dislocations seen by high-resolution transmission electron microscopy (HRTEM and substrate roughness of ∼1-2 unit cells, confirmed by atomic force microscopy and HRTEM. A combination of secondary sputtering, lattice mismatch, substrate roughness, and surface reduction creating secondary phase was likely the cause of surface roughness which should be reduced to a minimum level for effective use of it as buffer layers.

  3. High-Tc superconductivity in ultrathin Bi2Sr2CaCu2O(8+x) down to half-unit-cell thickness by protection with graphene.

    Science.gov (United States)

    Jiang, Da; Hu, Tao; You, Lixing; Li, Qiao; Li, Ang; Wang, Haomin; Mu, Gang; Chen, Zhiying; Zhang, Haoran; Yu, Guanghui; Zhu, Jie; Sun, Qiujuan; Lin, Chengtian; Xiao, Hong; Xie, Xiaoming; Jiang, Mianheng

    2014-12-08

    High-Tc superconductors confined to two dimension exhibit novel physical phenomena, such as superconductor-insulator transition. In the Bi2Sr2CaCu2O(8+x) (Bi2212) model system, despite extensive studies, the intrinsic superconducting properties at the thinness limit have been difficult to determine. Here, we report a method to fabricate high quality single-crystal Bi2212 films down to half-unit-cell thickness in the form of graphene/Bi2212 van der Waals heterostructure, in which sharp superconducting transitions are observed. The heterostructure also exhibits a nonlinear current-voltage characteristic due to the Dirac nature of the graphene band structure. More interestingly, although the critical temperature remains essentially the same with reduced thickness of Bi2212, the slope of the normal state T-linear resistivity varies by a factor of 4-5, and the sheet resistance increases by three orders of magnitude, indicating a surprising decoupling of the normal state resistance and superconductivity. The developed technique is versatile, applicable to investigate other two-dimensional (2D) superconducting materials.

  4. Modeled Thickness of the Overburden Geomodel Unit (obthk_f)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The obthk_f grid represents the modeled thickness of the Overburden geomodel unit at a 500 foot resolution. It is one grid of a geomodel that consists of eleven...

  5. Bi-Cell Unit for Fuel Cell.

    Science.gov (United States)

    The patent concerns a bi-cell unit for a fuel cell . The bi-cell unit is comprised of two electrode packs. Each of the electrode packs includes an...invention relates in general to a bi-cell unit for a fuel cell and in particular, to a bi-cell unit for a hydrazine-air fuel cell .

  6. Sickle Cell Unit.

    Science.gov (United States)

    Canipe, Stephen L.

    Included in this high school biology unit on sickle cell anemia are the following materials: a synopsis of the history of the discovery and the genetic qualities of the disease; electrophoresis diagrams comparing normal, homozygous and heterozygous conditions of the disease; and biochemical characteristics and population genetics of the disease. A…

  7. Elastic thickness compressibilty of the red cell membrane.

    OpenAIRE

    Heinrich, V; Ritchie, K; Mohandas, N; Evans, E.

    2001-01-01

    We have used an ultrasensitive force probe and optical interferometry to examine the thickness compressibility of the red cell membrane in situ. Pushed into the centers of washed-white red cell ghosts lying on a coverglass, the height of the microsphere-probe tip relative to its closest approach on the adjacent glass surface revealed the apparent material thickness, which began at approximately 90 nm per membrane upon detection of contact (force approximately 1-2 pN). With further impingement...

  8. Combined Thickness of the Modeled Saddle Mountains Basalt and Mabton Interbed Geomodel Units (smthk_f)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The smthk_f grid represents the modeled combined thickness of the Saddle Mountains Basalt and Mabton interbed geomodel units at a 500 foot resolution. It is one grid...

  9. Thickness of the Upper Hell Creek hydrogeologic unit in the Powder River structural basin

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — These data represent the thickness, in feet, of the Upper Hell Creek hydrogeologic unit in the Powder River basin. The data are presented as ASCII text files that...

  10. Thickness of the middle Fort Union hydrogeologic unit in the Williston structural basin

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — These data represent the thickness, in feet, of the middle Fort Union hydrogeologic unit in the Williston structural basin. The data are presented as ASCII text...

  11. Thickness of the Upper Hell Creek hydrogeologic unit in the Williston structural basin

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — These data represent the thickness, in feet, of the Upper Hell Creek hydrogeologic unit in the Williston structural basin. The data are presented as ASCII text...

  12. Thickness of the middle Fort Union hydrogeologic unit in the Powder River structural basin

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — These data represent the thickness, in feet, of the middle Fort Union hydrogeologic unit in the Powder River basin. The data are presented as ASCII text files that...

  13. Distribution and Aggregate Thickness of Salt Deposits of the United States

    Data.gov (United States)

    U.S. Environmental Protection Agency — The map shows the distribution and aggregate thickness of salt deposits of the United States. This information is from contour map sheets, scanned and processed for...

  14. Thick-film materials for silicon photovoltaic cell manufacture

    Science.gov (United States)

    Field, M. B.

    1977-01-01

    Thick film technology is applicable to three areas of silicon solar cell fabrication; metallization, junction formation, and coating for protection of screened ohmic contacts, particularly wrap around contacts, interconnection and environmental protection. Both material and process parameters were investigated. Printed ohmic contacts on n- and p-type silicon are very sensitive to the processing parameters of firing time, temperature, and atmosphere. Wrap around contacts are easily achieved by first printing and firing a dielectric over the edge and subsequently applying a low firing temperature conductor. Interconnection of cells into arrays can be achieved by printing and cofiring thick film metal pastes, soldering, or with heat curing conductive epoxies on low cost substrates. Printed (thick) film vitreous protection coatings do not yet offer sufficient optical uniformity and transparency for use on silicon. A sprayed, heat curable SiO2 based resin shows promise of providing both optical matching and environmental protection.

  15. Dielectrophoretic capture of low abundance cell population using thick electrodes

    Science.gov (United States)

    Marchalot, Julien; Chateaux, Jean-François; Faivre, Magalie; Mertani, Hichem C.; Ferrigno, Rosaria; Deman, Anne-Laure

    2015-01-01

    Enrichment of rare cell populations such as Circulating Tumor Cells (CTCs) is a critical step before performing analysis. This paper presents a polymeric microfluidic device with integrated thick Carbon-PolyDimethylSiloxane composite (C-PDMS) electrodes designed to carry out dielectrophoretic (DEP) trapping of low abundance biological cells. Such conductive composite material presents advantages over metallic structures. Indeed, as it combines properties of both the matrix and doping particles, C-PDMS allows the easy and fast integration of conductive microstructures using a soft-lithography approach while preserving O2 plasma bonding properties of PDMS substrate and avoiding a cumbersome alignment procedure. Here, we first performed numerical simulations to demonstrate the advantage of such thick C-PDMS electrodes over a coplanar electrode configuration. It is well established that dielectrophoretic force (FDEP) decreases quickly as the distance from the electrode surface increases resulting in coplanar configuration to a low trapping efficiency at high flow rate. Here, we showed quantitatively that by using electrodes as thick as a microchannel height, it is possible to extend the DEP force influence in the whole volume of the channel compared to coplanar electrode configuration and maintaining high trapping efficiency while increasing the throughput. This model was then used to numerically optimize a thick C-PDMS electrode configuration in terms of trapping efficiency. Then, optimized microfluidic configurations were fabricated and tested at various flow rates for the trapping of MDA-MB-231 breast cancer cell line. We reached trapping efficiencies of 97% at 20 μl/h and 78.7% at 80 μl/h, for 100 μm thick electrodes. Finally, we applied our device to the separation and localized trapping of CTCs (MDA-MB-231) from a red blood cells sample (concentration ratio of 1:10). PMID:26392836

  16. Modeled Thickness of the Grande Ronde Basalt Geomodel Unit (grthk_f)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The grthk_f grid represents the modeled thickness of the Gronde Ronde Basalt geomodel unit at a 500 foot resolution. It is one grid of a geomodel that consists of...

  17. Study of buffer layer thickness on bulk heterojunction solar cell.

    Science.gov (United States)

    Noh, Seunguk; Suman, C K; Lee, Donggu; Kim, Seohee; Lee, Changhee

    2010-10-01

    We studied the effect of the buffer layer (molybdenum-oxide (MoO3)) thickness on the performance of organic solar cell based on blends of poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C61 butyric acid methyl ester fullerene derivative (PCBM). The thickness of MoO3 was varied from 1 nm to 30 nm for optimization of device performance. The photocurrent-voltage and impedance spectroscopy were measured under dark and AM1.5G solar simulated illumination of 100 mW/cm2 for exploring the role of the buffer layer thickness on carrier collection at an anode. The MoO3 thickness of the optimized device (efficiency approximately 3.7%) was found to be in the range of 5 approximately 10 nm. The short-circuit current and the shunt resistance decrease gradually for thicker MoO3 layer over 5 nm. The device can be modeled as the combination of three RC parallel circuits (each one for the active layer, buffer layer and interface between the buffer layer and the active layer) in series with contact resistance (Rs approximately 60 ohm).

  18. Nanometer thickness laser ablation for spatial control of cell attachment

    Science.gov (United States)

    Thissen, H.; Hayes, J. P.; Kingshott, P.; Johnson, G.; Harvey, E. C.; Griesser, H. J.

    2002-10-01

    We demonstrate here a new method to control the location of cells on surfaces in two dimensions, which can be applied to a number of biomedical applications including diagnostic tests and tissue engineered medical devices. Two-dimensional control over cell attachment is achieved by generation of a spatially controlled surface chemistry that allows control over protein adsorption, a process which mediates cell attachment. Here, we describe the deposition of thin allylamine plasma polymer coatings on silicon wafer and perfluorinated poly(ethylene-co-propylene) substrates, followed by grafting of a protein resistant layer of poly(ethylene oxide). Spatially controlled patterning of the surface chemistry was achieved in a fast, one-step procedure by nanometer thickness controlled laser ablation using a 248 nm excimer laser. X-ray photoelectron spectroscopy and atomic force microscopy were used to confirm the production of surface chemistry patterns with a resolution of approximately 1 µm, which is significantly below the dimensions of a single mammalian cell. Subsequent adsorption of the extracellular matrix proteins collagen I and fibronectin followed by cell culture experiments using bovine corneal epithelial cells confirmed that cell attachment is controlled by the surface chemistry pattern. The method is an effective tool for use in a number of in vitro and in vivo applications.

  19. Study of the effect of membrane thickness on microcapsule strength, permeability, and cell proliferation.

    Science.gov (United States)

    Ma, Ying; Zhang, Ying; Wang, Yu; Wang, Qiuyan; Tan, Mingqian; Liu, Yang; Chen, Li; Li, Na; Yu, Weiting; Ma, Xiaojun

    2013-04-01

    Cell microencapsulation is one of the promising strategies for in vitro production of proteins or in vivo delivery of therapeutic products. Membrane thickness controls microcapsule strength and permeability, which may in return affect cell growth and metabolism. In this study, the strength, permeability, and encapsulated Chinese hamster ovary cell proliferation and metabolism of four groups of microcapsules with different membrane thicknesses were investigated. It was found that increasing membrane thickness increases microcapsule strength, whereas decreases membrane permeability. During the first 6 days, cells within microcapsules with 10 μm thickness membrane proliferated fast and could reach a cell density of 1.9 × 10(7) cells/mL microcapsule with 92% cell density. A cell density of 5.5 × 10(7) cells/mL microcapsule with >85% cell density was achieved within microcapsules with 15 μm membrane thickness and these microcapsules kept over 88% integrity ratio after 11 days, which was much higher than that of microcapsules with 10 μm membrane thickness. Membrane with more than 20 μm thickness was not suited for encapsulated cell culture owing to low-protein diffusion rate. These results indicated that cells survived shortly within the thinnest membrane thickness. There was a specific membrane thickness more suitable for cell growth for a long-time culture. These findings will be useful for preparing microcapsules with the desired membrane thickness for microencapsulated cell culture dependent on various purposes.

  20. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Raster surface depicting the thickness of the middle confining unit

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  1. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Points for the thickness of the regional middle confining unit

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  2. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Points depicting the thickness of the upper confining unit or limestone residuum

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  3. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Points for the thickness of the Bucatunna clay confining unit

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  4. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Raster surface depicting the thickness of the Bucatunna clay confining unit

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  5. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Polygons representing thickness of the upper confining unit of the Floridan aquifer system

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  6. Synthesis of dye-sensitized solar cells. Efficiency cells as a thickness of titanium dioxide

    Science.gov (United States)

    Szura, Dominika

    2016-12-01

    Defying the influence of the thickness of TiO2 efficiency of dye-sensitized solar cell. It was confirmed that the compatibility of printed layers with the parameters closely related with the DSSC. It was found that the increase in thickness of the titanium dioxide layer, increases the distance between the electrodes, determined by the thickness of the Surlyn foil. With the rise of thickness of dyed layer of TiO2 established decrease in the value of its transmittance. Greatest transparency and aesthetic value obtained for photovoltaic modules with a single layer of titanium dioxide. The improved performance efficiency and preferred yields maximum power were noticed and exhibited by the cells covered with three layers of TiO2. It was established that the behaviour of economic efficiency in the production process, provides a range of cells with two layers of oxide, showing a similar performance and greater transparency.

  7. Synthesis of dye-sensitized solar cells. Efficiency cells as a thickness of titanium dioxide

    Directory of Open Access Journals (Sweden)

    Szura Dominika

    2017-01-01

    Full Text Available Defying the influence of the thickness of TiO2 efficiency of dye-sensitized solar cell. It was confirmed that the compatibility of printed layers with the parameters closely related with the DSSC. It was found that the increase in thickness of the titanium dioxide layer, increases the distance between the electrodes, determined by the thickness of the Surlyn foil. With the rise of thickness of dyed layer of TiO2 established decrease in the value of its transmittance. Greatest transparency and aesthetic value obtained for photovoltaic modules with a single layer of titanium dioxide. The improved performance efficiency and preferred yields maximum power were noticed and exhibited by the cells covered with three layers of TiO2. It was established that the behaviour of economic efficiency in the production process, provides a range of cells with two layers of oxide, showing a similar performance and greater transparency.

  8. Origin, Extent, and Thickness of Quaternary Geologic Units in the Willamette Valley, Oregon

    Science.gov (United States)

    O'Connor, Jim E.; Sarna-Wojcicki, Andrei M.; Wozniak, Karl C.; Polette, Danial J.; Fleck, Robert J.

    2001-01-01

    Stratigraphic and chronologic information collected for Quaternary deposits in the Willamette Valley, Oregon, provides a revised stratigraphic framework that serves as a basis for a 1:250,000-scale map, as well as for thickness estimates of widespread Quaternary geologic units. We have mapped 11 separate Quaternary units that are differentiated on the basis of stratigraphic, topographic, pedogenic, and hydrogeologic properties. In summation, these units reflect four distinct episodes in the Quaternary geologic development of the Willamette Valley: 1) Fluvial sands and gravels that underlie terraces flanking lowland margins and tributary valleys were probably deposited between 2.5 and 0.5 million years ago. They are the oldest widespread surficial Quaternary deposits in the valley. Their present positions and preservation are undoubtedly due to postdepositional tectonic deformation - either by direct tectonic uplift of valley margins, or by regional tectonic controls on local base level. 2) Tertiary and Quaternary excavation or tectonic lowering of the Willamette Valley accommodated as much as 500 m (meters) of lacustrine and fluvial fill. Beneath the lowland floor, much of the upper 10 to 50 m of fill is Quaternary sand and gravel deposited by braided channel systems in subhorizontal sheets 2 to 10 m thick. These deposits grade to gravel fans 40 to 100 m thick where major Cascade Range rivers enter the valley and are traced farther upstream as much thinner valley trains of coarse gravel. The sand and gravel deposits have ages that range from greater than 420,000 to about 12,000 years old. A widely distributed layer of sand and gravel deposited at about 12 ka (kiloannum, thousands of years before the present) is looser and probably more permeable than older sand and gravel. Stratigraphic exposures and drillers' logs indicate that this late Pleistocene unit is mostly between 5 and 20 m thick where it has not been subsequently eroded by the Willamette River and its

  9. Combined Thickness of the Modeled Wanapum Basalt and Vantage-Latah Interbed Geomodel Units (wnthk_f)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The wnthk_f grid represents the modeled combined thickness of the Wanapum Basalt and the Vantage/Latah interbed geomodel units at a 500 foot resolution. It is one...

  10. Spacer Thickness-Dependent Electron Transport Performance of Titanium Dioxide Thick Film for Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Reda E. El-Shater

    2015-01-01

    Full Text Available A titanium dioxide (P25 film was deposited by cast coating as conductive photoelectrode and subsequently immersed in dye solution (N719 to fabricate the photoanode of dye-sensitized solar cells (DSSCs. A plastic spacer was used as a separation and sealant layer between the photoanode and the counter electrode. The effect of the thickness of this spacer on the transfer of electrons in the liquid electrolyte of the DSSCs was studied by means of both IV curves and electrochemical impedance. Using a spacer thickness range of 20 μm to 50 μm, efficiency ranges from 3.73% to 7.22%. The highest efficiency of 7.22% was obtained with an optimal spacer thickness of 40 μm.

  11. on THICKNESS OF COPPER (|) OXIDE (Cu2"O) SOLAR CELL

    African Journals Online (AJOL)

    thickness of copper oxides solar ce[[s prepared 63/ thermaf oxidation method The sampfes were oxidized at di_';§'erent oxidation temperatures and time. The diflerent oxidation ... observed that the later was relatively high. Adrianus (1978).

  12. Study of the effect of membrane thickness on microcapsule strength, permeability, and cell proliferation

    DEFF Research Database (Denmark)

    Ma, Ying; Zhang, Ying; Wang, Yu;

    2013-01-01

    Cell microencapsulation is one of the promising strategies for in vitro production of proteins or in vivo delivery of therapeutic products. Membrane thickness controls microcapsule strength and permeability, which may in return affect cell growth and metabolism. In this study, the strength......, permeability, and encapsulated Chinese hamster ovary cell proliferation and metabolism of four groups of microcapsules with different membrane thicknesses were investigated. It was found that increasing membrane thickness increases microcapsule strength, whereas decreases membrane permeability. During...... the first 6 days, cells within microcapsules with 10 μm thickness membrane proliferated fast and could reach a cell density of 1.9 × 10(7) cells/mL microcapsule with 92% cell density. A cell density of 5.5 × 10(7) cells/mL microcapsule with >85% cell density was achieved within microcapsules with 15 μm...

  13. Dendritic thickness: a morphometric parameter to classify mouse retinal ganglion cells

    Directory of Open Access Journals (Sweden)

    L.D. Loopuijt

    2007-10-01

    Full Text Available To study the dendritic morphology of retinal ganglion cells in wild-type mice we intracellularly injected these cells with Lucifer yellow in an in vitro preparation of the retina. Subsequently, quantified values of dendritic thickness, number of branching points and level of stratification of 73 Lucifer yellow-filled ganglion cells were analyzed by statistical methods, resulting in a classification into 9 groups. The variables dendritic thickness, number of branching points per cell and level of stratification were independent of each other. Number of branching points and level of stratification were independent of eccentricity, whereas dendritic thickness was positively dependent (r = 0.37 on it. The frequency distribution of dendritic thickness tended to be multimodal, indicating the presence of at least two cell populations composed of neurons with dendritic diameters either smaller or larger than 1.8 µm ("thin" or "thick" dendrites, respectively. Three cells (4.5% were bistratified, having thick dendrites, and the others (95.5% were monostratified. Using k-means cluster analysis, monostratified cells with either thin or thick dendrites were further subdivided according to level of stratification and number of branching points: cells with thin dendrites were divided into 2 groups with outer stratification (0-40% and 2 groups with inner (50-100% stratification, whereas cells with thick dendrites were divided into one group with outer and 3 groups with inner stratification. We postulate, that one group of cells with thin dendrites resembles cat ß-cells, whereas one group of cells with thick dendrites includes cells that resemble cat a-cells.

  14. Unit: Cells, Inspection Set, National Trial Print.

    Science.gov (United States)

    Australian Science Education Project, Toorak, Victoria.

    This trial version of a unit is the series being produced by the Australian Science Education Project provides instructions for students to prepare a variety of cell types and examine them with microscopes. It also gives some information about the variety and function of cells. The core of the unit, which all students are expected to complete,…

  15. Quantification of cell-free layer thickness and cell distribution of blood by optical coherence tomography

    Science.gov (United States)

    Lauri, Janne; Bykov, Alexander; Fabritius, Tapio

    2016-04-01

    A high-speed optical coherence tomography (OCT) with 1-μm axial resolution was applied to assess the thickness of a cell-free layer (CFL) and a spatial distribution of red blood cells (RBC) next to the microchannel wall. The experiments were performed in vitro in a plain glass microchannel with a width of 2 mm and height of 0.2 mm. RBCs were suspended in phosphate buffered saline solution at the hematocrit level of 45%. Flow rates of 0.1 to 0.5 ml/h were used to compensate gravity induced CFL. The results indicate that OCT can be efficiently used for the quantification of CFL thickness and spatial distribution of RBCs in microcirculatory blood flow.

  16. Influence of thickness on physical properties of vacuum evaporated polycrystalline CdTe thin films for solar cell applications

    Science.gov (United States)

    Chander, Subhash; Dhaka, M. S.

    2016-02-01

    This paper presents the influence of thickness on physical properties of polycrystalline CdTe thin films. The thin films of thickness 450 nm, 650 nm and 850 nm were deposited employing thermal vacuum evaporation technique on glass and indium tin oxide (ITO) coated glass substrates. The physical properties of these as-grown thin films were investigated employing the X-ray diffraction (XRD), source meter, UV-Vis spectrophotometer, scanning electron microscopy (SEM) coupled with energy dispersive spectroscopy (EDS). The structural analysis reveals that the films have zinc-blende cubic structure and polycrystalline in nature with preferred orientation (111). The structural parameters like lattice constant, interplanar spacing, grain size, strain, dislocation density and number of crystallites per unit area are calculated. The average grain size and optical band gap are found in the range 15.16-21.22 nm and 1.44-1.63 eV respectively and observed to decrease with thickness. The current-voltage characteristics show that the electrical conductivity is observed to decrease with thickness. The surface morphology shows that films are free from crystal defects like pin holes and voids as well as homogeneous and uniform. The EDS patterns show the presence of cadmium and tellurium elements in the as grown films. The experimental results reveal that the film thickness plays significant role on the physical properties of as-grown CdTe thin films and higher thickness may be used as absorber layer to solar cells applications.

  17. Some investigations on thickness-dependent electrical behaviour of CdS:As/electrolyte solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Deshmukh, L.P. (Dept. of Applied Electronics, Shivaji Univ., Solapur (India)); Hankare, P.P. (Dept. of Polymer Chemistry, Shivaji Univ., Solapur (India)); Sawant, V.S. (Dept. of Electronics, Y.C. Inst. of Science, Satara (India))

    1991-12-01

    An investigation has been made into the effect of photoelectrode thickness of the photovoltaic properties of cadmium sulphide/electrolyte solar cells. CdS photoelectrodes of various thicknesses doped with 0.25wt.% arsenic were prepared by a chemical deposition process on plane mirror smooth stainless steel substrates. An electrode/electrolyte junction cell was designed for use in a glass cuvette and has been analysed in terms of its electrical parameters. The thickness of the photoelectrode was found to cause significant changes in cell parameters such as short-circuit current, open-circuit voltage, series and shunt resistances, fill factor, junction quality factors and flat band potential. (orig.).

  18. Patterns of cell thickness oscillations during directional migration of Physarum polycephalum.

    Science.gov (United States)

    Rodiek, Beatrice; Takagi, Seiji; Ueda, Tetsuo; Hauser, Marcus J B

    2015-07-01

    The functional relationship between the velocity of cell locomotion and intracellular spatial patterns of thickness oscillations in the acellular slime mould Physarum polycephalum was studied. The freely migrating plasmodial cells of 300-800 µm length were tadpole-shaped and displayed thickness oscillations along their longitudinal (body) axis. Two distinct patterns of intracellular thickness oscillations were observed in dependence on the locomotive velocity. The first mode consisted of a single travelling wave that propagated from the rear to the front of the cell. This pattern occurred when the plasmodium migrated slowly. The second mode was a multinodal standing wave that was found during events of fast propagation. Transitions between these two types of cell thickness oscillation patterns took place in narrow propagation velocity intervals. We discuss the possible mechanism leading to these patterns, which are conjectured to modulate both the intracellular pressure and the velocity of free locomotion of the cell.

  19. Contractile Stresses in Cohesive Cell Layers on Finite-Thickness Substrates

    Science.gov (United States)

    Banerjee, Shiladitya; Marchetti, M. Cristina

    2012-09-01

    Using a minimal model of cells or cohesive cell layers as continuum active elastic media, we examine the effect of substrate thickness and stiffness on traction forces exerted by strongly adhering cells. We obtain a simple expression for the length scale controlling the spatial variation of stresses in terms of cell and substrate parameters that describes the crossover between the thin and thick substrate limits. Our model is an important step towards a unified theoretical description of the dependence of traction forces on cell or colony size, acto-myosin contractility, substrate depth and stiffness, and strength of focal adhesions and makes experimentally testable predictions.

  20. Optimization of substrate thickness for interdigitated back contact silicon solar cells

    Science.gov (United States)

    Verlinden, P.; van de Wiele, F.

    1983-08-01

    A computer model for the computation of the optimum substrate thickness of interdigitated-back-contact (IBC) Si solar cells is developed and demonstrated. The one-dimensional model assumes that solar-cell quantum efficiency is fully determined by minority-carrier diffusion length, surface recombination velocity, and substrate thickness, and hence unaffected by back-diffused layers. The maximum thickness allowable for a 10-percent reduction in short-circuit current density can also be determined. Optimum and maximum-allowable thicknesses are plotted as functions of diffusion length for different recombination velocities, using input parameters typical of lightly doped n-type and p-type backlit IBC cells under AM 1.5 illumination at 300 K. Good agreement is found with empirical parameter values determined by curve fitting.

  1. Oxide-Based Solar Cell: Impact of Layer Thicknesses on the Device Performance.

    Science.gov (United States)

    Panigrahi, Shrabani; Nunes, Daniela; Calmeiro, Tomás; Kardarian, Kasra; Martins, Rodrigo; Fortunato, Elvira

    2017-02-13

    A ZnO/Cu2O-based combinatorial heterojunction device library was successfully fabricated by a simple spray pyrolysis technique using ITO-coated glass as the substrate. The combinatorial approach was introduced to analyze the impact of the ZnO and Cu2O layer thicknesses on the performance of the solar cells. The thickness of the ZnO layer was varied from ∼50 to 320 nm, and the Cu2O layer was deposited orthogonal to the ZnO thickness gradient. In the case of Cu2O, the thickness varied from ∼200 to 800 nm. The photovoltaic performance of the cells is strongly dependent on the absorber layer thickness for a particular window layer thickness and reaches a maximum short-circuit current density of 3.9 mA/cm(2) when the absorber layer thickness just crosses ∼700 nm. Reducing the thicknesses of the active layers leads to a sharp decrease in the device performance. It is shown that the entire built-in bias of the heterojunction is created in the absorber layer due to low carrier density. The poor performance of the devices having lower thicknesses is attributed to different interfacial phenomena such as optical losses due to the thin Cu2O layer, back-contact recombination of the carriers due to the low layer thickness because a minimum heterojunction thickness is required for the formation of the full built-in bias that slows down the recombination of the carriers, and other factors.

  2. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Raster surface generated for the "freshwater" thickness of the Floridan aquifer system

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  3. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Raster surface depicting the thickness of the MAPCU

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  4. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Points for the thickness of the MAPCU

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  5. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Raster surface depicting the thickness of the Floridan aquifer system

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  6. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Thickness raster surface for surficial deposits, clipped

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  7. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Raster surface depicting the thickness of residuum in southwestern Georgia and southeastern Alabama

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  8. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Points for the thickness of the OCAPLPZ

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  9. Thickness optimization of Mo films for Cu(InGa)Se2 solar cell applications

    Institute of Scientific and Technical Information of China (English)

    Li Wei; Zhao Yan-Min; Liu Xing-Jiang; Ao Jian-Ping; Sun Yun

    2011-01-01

    Mo thin films are deposited on soda lime glass (SLG) substrates using DC magnetron sputtering. The Mo film thicknesses are varied from 0.08 μm to 1.5 μm to gain a better understanding of the growth process of the film. The residual stresses and the structural properties of these films are investigated, with attention paid particularly to the film thickness dependence of these properties. Residual stress decreases and yields a typical tensile-to-compressive stress transition with the increase of film thickness at the first stages of film growth. The stress tends to be stable with the further increase of film thickness. Using the Mo film with an optimum thickness of 1 μm as the back contact, the Cu(InGa)Se2 solar cell can reach a conversion efficiency of 13.15%.

  10. STATISTICAL ANALYSIS OF THE LOCAL STRUT THICKNESS OF OPEN CELL FOAMS

    Directory of Open Access Journals (Sweden)

    André Liebscher

    2013-03-01

    Full Text Available Open cell foams are formed by an interconnected network of struts whose thickness varies locally. These variations were shown to have an impact on the elastic and thermal properties of the foam. In this paper we quantify the local strut thickness by means of micro computed tomography (µCT imaging. We introduce a skeletonization based topological decomposition of the foam structure into its vertices and struts. This allows to estimate the thickness of individual strut segments by the Euclidean distance transform, where an appropriate correction for struts with nonspherical cross-sectional shape is applied. Conflating these estimates based on the strut lengths results in a strut thickness profile for the entire foam. Polynomial models for the strut thickness profile are investigated by means of a regression analysis.

  11. Thickness optimization of the ZnO based TCO layer in a CZTSSe solar cell. Evolution of its performance with thickness when external temperature changes.

    Science.gov (United States)

    Chadel, Meriem; Moustafa Bouzaki, Mohammed; Chadel, Asma; Aillerie, Michel; Benyoucef, Boumediene

    2017-07-01

    The influence of the thickness of a Zinc Oxide (ZnO) transparent conductive oxide (TCO) layer on the performance of the CZTSSe solar cell is shown in detail. In a photovoltaic cell, the thickness of each layer largely influence the performance of the solar cell and optimization of each layer constitutes a complete work. Here, using the Solar Cell Capacitance Simulation (SCAPS) software, we present simulation results obtained in the analyze of the influence of the TCO layer thickness on the performance of a CZTSSe solar cell, starting from performance of a CZTSSe solar cell commercialized in 2014 with an initial efficiency equal to 12.6%. In simulation, the temperature was considered as a functioning parameter and the evolution of tthe performance of the cell for various thickness of the TCO layer when the external temperature changes is simulated and discussed. The best efficiency of the solar cell based in CZTSSe is obtained with a ZnO thickness equal to 50 nm and low temperature. Based on the considered marketed cell, we show a technological possible increase of the global efficiency achieving 13% by optimization of ZnO based TCO layer.

  12. Dependence of interparticle force on temperature and cell thickness in nematic colloids.

    Science.gov (United States)

    Kondo, Noboru; Iwashita, Yasutaka; Kimura, Yasuyuki

    2010-08-01

    We have experimentally studied the interparticle force between two particles accompanied by hyperbolic hedgehog defects in a nematic liquid crystal. The force F was measured with dual-beam optical tweezers at various temperatures and in cells with various thicknesses. In a thick cell, the dependence of F on the interparticle distance R obtained at different temperatures can be scaled to a universal curve of F∝R^(-4) for R>3a , where a is the radius of a particle. The effective elastic constant evaluated from F is found to be in good agreement with splay constant of the nematic liquid crystal. In a thin cell, the magnitude of F decreases and the dependence of F on R becomes short-ranged as the thickness of a cell, L , decreases. The reduced force curves, FL(4) against R/L , at different L are found to be scaled to a single theoretical curve which has been proposed recently.

  13. Altitudes and thicknesses of hydrogeologic units of the Ozark Plateaus aquifer system in Arkansas, Kansas, Missouri, and Oklahoma

    Science.gov (United States)

    Westerman, Drew A.; Gillip, Jonathan A.; Richards, Joseph M.; Hays, Phillip D.; Clark, Brian R.

    2016-09-29

    A hydrogeologic framework was constructed to represent the altitudes and thicknesses of hydrogeologic units within the Ozark Plateaus aquifer system as part of a regional groundwater-flow model supported by the U.S. Geological Survey Water Availability and Use Science Program. The Ozark Plateaus aquifer system study area is nearly 70,000 square miles and includes parts of Arkansas, Kansas, Missouri, and Oklahoma. Nine hydrogeologic units were selected for delineation within the aquifer system and include the Western Interior Plains confining system, the Springfield Plateau aquifer, the Ozark confining unit, the Ozark aquifer, which was divided into the upper, middle, and lower Ozark aquifers to better capture the spatial variation in the hydrologic properties, the St. Francois confining unit, the St. Francois aquifer, and the basement confining unit. Geophysical and well-cutting logs, along with lithologic descriptions by well drillers, were compiled and interpreted to create hydrologic altitudes for each unit. The final compiled dataset included more than 23,000 individual altitude points (excluding synthetic points) representing the nine hydrogeologic units within the Ozark Plateaus aquifer system.

  14. Shadow Radiation Shield Required Thickness Estimation for Space Nuclear Power Units

    Science.gov (United States)

    Voevodina, E. V.; Martishin, V. M.; Ivanovsky, V. A.; Prasolova, N. O.

    The paper concerns theoretical possibility of visiting orbital transport vehicles based on nuclear power unit and electric propulsion system on the Earth's orbit by astronauts to maintain work with payload from the perspective of radiation safety. There has been done estimation of possible time of the crew's staying in the area of payload of orbital transport vehicles for different reactor powers, which is a consistent part of nuclear power unit.

  15. Film thickness effect on the performance of small molecular solar cell

    Institute of Scientific and Technical Information of China (English)

    LIN Hui; YU Jun-sheng; HUANG Jiang; JIANG Ya-dong

    2008-01-01

    An efficient organic photovoltaic (OPV) cell with an indium-tin-oxide/CuPc/C60/Ag structure has been investigated by changing the film thickness of organic layers. A high open-circuit voltage (Voc) of 0.5 V, a short-circuit current density (JSC) of 5.81 mA/cm2, and a high power conversion efficiency (ηp) of 1.2% were achieved at an optimum film thickness. The results demonstrate that material thickness is an important factor to cell optimization, especially for maximizing the absorption rate as well as reducing the cell resistance. Experimental results also indicate that the power conversion efficiency increases from 1.2% to 1.54% as a BCP exciton blocking layer of 10 nm is introduced.

  16. Enhanced photocurrent density in graphene/Si based solar cell (GSSC) by optimizing active layer thickness

    Energy Technology Data Exchange (ETDEWEB)

    Rosikhin, Ahmad, E-mail: a.rosikhin86@yahoo.co.id; Hidayat, Aulia Fikri; Syuhada, Ibnu; Winata, Toto, E-mail: toto@fi.itb.ac.id [Department of physics, physics of electronic materials research division Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung Jl. Ganesha 10, Bandung 40132, Jawa Barat – Indonesia (Indonesia)

    2015-12-29

    Thickness dependent photocurrent density in active layer of graphene/Si based solar cell has been investigated via analytical – simulation study. This report is a preliminary comparison of experimental and analytical investigation of graphene/Si based solar cell. Graphene sheet was interfaced with Si thin film forming heterojunction solar cell that was treated as a device model for photocurrent generator. Such current can be enhanced by optimizing active layer thickness and involving metal oxide as supporting layer to shift photons absorption. In this case there are two type of devices model with and without TiO{sub 2} in which the silicon thickness varied at 20 – 100 nm. All of them have examined and also compared with each other to obtain an optimum value. From this calculation it found that generated currents almost linear with thickness but there are saturated conditions that no more enhancements will be achieved. Furthermore TiO{sub 2} layer is effectively increases photon absorption but reducing device stability, maximum current is fluctuates enough. This may caused by the disturbance of excitons diffusion and resistivity inside each layer. Finally by controlling active layer thickness, it is quite useful to estimate optimization in order to develop the next solar cell devices.

  17. Effects of diabetic keratopathy on corneal optical density, central corneal thickness, and corneal endothelial cell counts.

    Science.gov (United States)

    Gao, Feng; Lin, Tao; Pan, Yingzhe

    2016-09-01

    Diabetic keratopathy is an ocular complication that occurs with diabetes. In the present study, the effect of diabetic keratopathy on corneal optical density, central corneal thickness, and corneal endothelial cell count was investigated. One hundred and eighty diabetic patients (360 eyes) were enrolled in the study during the period from March, 2012 to March, 2013. The patients were divided into three age groups: 10 years, with 60 patients per group (120 eyes). During the same period, 60 healthy cases (120 eyes) were selected and labeled as the normal control group. The Pentacam was used to measure the corneal optical density, and central corneal thickness. Specular microscopy was used to examine the corneal endothelial cell density. The coefficient of partial correlation was used to control age and correlate the analysis between the corneal optical density, corneal endothelial cell density, and central corneal thickness. The stage of the disease, the medial and intimal corneal optical density and central corneal thickness was analyzed in the diabetes group. The corneal optical density in the diabetes group increased compared with that of the normal control group. The medial and intimal corneal optical density and central corneal thickness were positively correlated with the course of the disease. However, the corneal endothelial cell density was not associated with the course of diabetes. There was a positive association between the medial and intimal corneal optical density and central corneal thickness of the diabetic patients. In conclusion, the results of the present study show that medial and intimal corneal optical density and central corneal thickness were sensitive indicators for early diabetic keratopathy.

  18. Single crystals of fullerene (C60 makes organic thick film solar cells and self supporting organic solar cells possible.

    Directory of Open Access Journals (Sweden)

    M. Umeno

    2008-06-01

    Full Text Available Single crystals of Fullerene (SC-C60 were synthesized by simple liquid/liquid interface precipitation method. Organic thick film solar cell (with an active layer thickness of approximately 20 microns thick is demonstrated by combining SC-C60 with poly(3-octylthiophene. Our preliminary results indicate that organic thick film solar cells are possible; which were considered to be impossible due to low mobility and small exciton diffusion lengths in most of the organic materials including small organic molecules and conjugated conducting polymers. Further, SC-C60 seems to be promising materials for organic photovoltaics. Self supporting organic solar cell is also demonstrated using SC-C60.

  19. Overview of thick-film technology as applied to solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Firor, K.; Hogan, S.

    1980-01-01

    Thick-film technology was developed by the electronics industry as a means of fabricating components and miniature circuitry. Today, the solar cell industry is looking at screen printing as an alternate to more expensive, high-vacuum techniques in several of the production steps during the manufacture of silicon solar cells. Screen printing is already fairly well established as a means of providing electrical contact to a cell and for the formation of a back surface field. Now under investigation are the possibilities of non-noble metal contacts and protective and antireflective coatings applied to solar cells by the use of screen printing. Most exciting is the work being done in the non-silicon area on the fabrication of the active layers of a solar cell, using thick-film inks made up of II-VI semiconductors.

  20. Reversible (unitized) PEM fuel cell devices

    Energy Technology Data Exchange (ETDEWEB)

    Mitlitsky, F; Myers, B; Smith, W F; Weisberg, Molter, T M

    1999-06-01

    Regenerative fuel cells (RFCs) are enabling for many weight-critical portable applications, since the packaged specific energy (>400 Wh/kg) of properly designed lightweight RFC systems is several-fold higher than that of the lightest weight rechargeable batteries. RFC systems can be rapidly refueled (like primary fuel cells), or can be electrically recharged (like secondary batteries) if a refueling infrastructure is not conveniently available. Higher energy capacity systems with higher performance, reduced weight, and freedom from fueling infrastructure are the features that RFCs promise for portable applications. Reversible proton exchange membrane (PEM) fuel cells, also known as unitized regenerative fuel cells (URFCs), or reversible regenerative fuel cells, are RFC systems which use reversible PEM cells, where each cell is capable of operating both as a fuel cell and as an electrolyzer. URFCs further economize portable device weight, volume, and complexity by combining the functions of fuel cells and electrolyzers in the same hardware, generally without any system performance or efficiency reduction. URFCs are being made in many forms, some of which are already small enough to be portable. Lawrence Livermore National Laboratory (LLNL) has worked with industrial partners to design, develop, and demonstrate high performance and high cycle life URFC systems. LLNL is also working with industrial partners to develop breakthroughs in lightweight pressure vessels that are necessary for URFC systems to achieve the specific energy advantages over rechargeable batteries. Proton Energy Systems, Inc. (Proton) is concurrently developing and commercializing URFC systems (UNIGEN' product line), in addition to PEM electrolyzer systems (HOGEN' product line), and primary PEM fuel cell systems. LLNL is constructing demonstration URFC units in order to persuade potential sponsors, often in their own conference rooms, that advanced applications based on URFC s are

  1. Sub-natural width resonances in Cs vapor confined in micrometric thickness optical cell

    Science.gov (United States)

    Cartaleva, S.; Krasteva, A.; Sargsyan, A.; Sarkisyan, D.; Slavov, D.; Vartanyan, T.

    2013-03-01

    We present here the behavior of Electromagnetically Induced Transparency (EIT), Velocity Selective Optical Pumping (VSOP) resonances and Velocity Selective Excitation (VSE) resonances observed in Cs vapor confined in а micrometric optical cell (MC) with thickness L = 6λ, λ = 852nm. For comparison of behavior of VSE resonance another conventional optical cell with thickness L=2.5 cm is used. Cells are irradiated in orthogonal to their windows directions by probe beam scanned on the Fg = 4 → Fe= 3, 4, 5 set of transitions and pump beam fixed at the Fg = 3 → Fe = 4 transition, on the D2 line of Cs. The enhanced absorption (fluorescence) narrow VSOP resonance at the closed transition transforms into reduced absorption (fluorescence) one with small increase of atomic concentration or light intensity. A striking difference appears between the VSE resonance broadening in L = 6λ and conventional L = 2.5cm cells.

  2. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Key well sites

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  3. Effect of Nanotube Film Thickness on the Performance of Nanotube-Silicon Hybrid Solar Cells

    Science.gov (United States)

    Tune, Daniel D.; Shapter, Joseph G.

    2013-01-01

    The results of measurements on solar cells made from randomly aligned thin films of single walled carbon nanotubes (SWCNTs) on n-type monocrystalline silicon are presented. The films are made by vacuum filtration from aqueous TritonX-100 suspensions of large diameter arc-discharge SWCNTs. The dependence of the solar cell performance on the thickness of the SWCNT film is shown in detail, as is the variation in performance due to doping of the SWCNT film with SOCl2.

  4. Estimated red blood cell thickness in microcytic anemia due to iron deficiency anemia and thalassemia

    Directory of Open Access Journals (Sweden)

    Viroj Wiwanitkit

    2009-05-01

    Full Text Available "nAnemia is one of the most common hematological disorders that are still the present in all countries around the world. Microcytic anemia is a specific kind of anemia presenting with small red blood cell. In this paper, the author discusses on the estimated red blood cell thickness, a new proposed parameter, comparing between that of iron deficiency anemia and thalassemia and further extrapolate on the clinical implication.

  5. Effect of photoanode thickness on electrochemical performance of dye sensitized solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Khatani, Mehboob, E-mail: mkhatani@hotmail.com; Hamid, Nor Hisham, E-mail: hishmid@petronas.com.my; Sahmer, Ahmed Zahrin, E-mail: azclement@yahoo.com [Electrical Engineering Department, UTP (Malaysia); Mohamed, Norani Muti, E-mail: noranimuti-mohamed@petronas.com.my; Muhsan, Ali Samer, E-mail: ali.samer@petronas.com.my [Centre of Innovative Nanostructures and Nanodevices (COINN), UTP (Malaysia)

    2015-07-22

    The thickness of photoanode is crucial as it adsorbed a large amount of dye molecules that provide electrons for generation of electricity in dye sensitized solar cell (DSC). Thus, in order to realize the practical application of DSC, study on various thickness of photoanode need to be carried out to analyze its effect on the electrochemical behavior of dye sensitized solar cell. To enhance the conversion efficiency, an additional layer of TiO{sub 2} using TiCl{sub 4} treatment was deposited prior to the deposition of the photoanode (active area of 1cm{sup 2}) with the thickness of 6, 12, 18, 24, and 30 µm on fluorine doped tin oxide (FTO) glass substrate. The resulting photoanode after the soak in N719 dye for more than 12hrs were used to be assembled in a test cell in combination with liquid electrolyte and counter electrode. The fabricated cells were characterized by solar simulator, ultraviolet-visible spectroscopy (UV-VIS), and electrochemical impedance spectroscopy (EIS). Scanning electron microscopy (SEM) was used to approximate the thickness of photoanode. An optimum power conversion efficiency of 4.54% was obtained for the cell fabricated with 18 µm photoanode thickness. This is attributed to the reduced resistance related to electron transport in the TiO{sub 2}/dye/electrolyte interface as proven by the EIS result. This led to the reduction of internal resistance, the increase in the electron life time and the improvement in the conversion efficiency.

  6. Influence of window layer thickness on double layer antirefiection coating for triple junction solar cells*

    Institute of Scientific and Technical Information of China (English)

    Wang Lijuan; Zhan Feng; Yu Ying; Zhu Yan; Liu Shaoqing; Huang Shesong; Ni Haiqiao; Niu Zhichuan

    2011-01-01

    The optimization of a SiO2/TiO2, SiO2/ZnS double layer antireflection coating (ARC) on Ga0.5ln0.5P/ln0.02Ga0.98As/Ge solar cells for terrestrial application is discussed. The Al0.5In0.5P window layer thickness is also taken into consideration. It is shown that the optimal parameters of double layer ARC vary with the thickness of the window layer.

  7. Experimental broadband absorption enhancement in silicon nanohole structures with optimized complex unit cells.

    Science.gov (United States)

    Lin, Chenxi; Martínez, Luis Javier; Povinelli, Michelle L

    2013-09-09

    We design silicon membranes with nanohole structures with optimized complex unit cells that maximize broadband absorption. We fabricate the optimized design and measure the optical absorption. We demonstrate an experimental broadband absorption about 3.5 times higher than an equally-thick thin film.

  8. Aqueous Solution Processed Photoconductive Cathode Interlayer for High Performance Polymer Solar Cells with Thick Interlayer and Thick Active Layer.

    Science.gov (United States)

    Nian, Li; Chen, Zhenhui; Herbst, Stefanie; Li, Qingyuan; Yu, Chengzhuo; Jiang, Xiaofang; Dong, Huanli; Li, Fenghong; Liu, Linlin; Würthner, Frank; Chen, Junwu; Xie, Zengqi; Ma, Yuguang

    2016-09-01

    An aqueous-solution-processed photoconductive cathode interlayer is developed, in which the photoinduced charge transfer brings multiple advantages such as increased conductivity and electron mobility, as well as reduced work function. Average power conversion efficiency over 10% is achieved even when the thickness of the cathode interlayer and active layer is up to 100 and 300 nm, respectively.

  9. Uninduced adipose-derived stem cells repair the defect of full-thickness hyaline cartilage.

    Science.gov (United States)

    Zhang, Hai-Ning; Li, Lei; Leng, Ping; Wang, Ying-Zhen; Lv, Cheng-Yu

    2009-04-01

    To testify the effect of the stem cells derived from the widely distributed fat tissue on repairing full-thickness hyaline cartilage defects. Adipose-derived stem cells (ADSCs) were derived from adipose tissue and cultured in vitro. Twenty-seven New Zealand white rabbits were divided into three groups randomly. The cultured ADSCs mixed with calcium alginate gel were used to fill the full-thickness hyaline cartilage defects created at the patellafemoral joint, and the defects repaired with gel or without treatment served as control groups. After 4, 8 and 12 weeks, the reconstructed tissue was evaluated macroscopically and microscopically. Histological analysis and qualitative scoring were also performed to detect the outcome. Full thickness hyaline cartilage defects were repaired completely with ADSCs-derived tissue. The result was better in ADSCs group than the control ones. The microstructure of reconstructed tissue with ADSCs was similar to that of hyaline cartilage and contained more cells and regular matrix fibers, being better than other groups. Plenty of collagen fibers around cells could be seen under transmission electron microscopy. Statistical analysis revealed a significant difference in comparison with other groups at each time point (t equal to 4.360, P less than 0.01). These results indicate that stem cells derived from mature adipose without induction possess the ability to repair cartilage defects.

  10. Uninduced adipose-derived stem cells repair the defect of full-thickness hyaline cartilage

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hai-ning; LI Lei; LENG Ping; WANG Ying-zhen; Lü Cheng-yu

    2009-01-01

    Objective: To testify the effect of the stem cells derived from the widely distributed fat tissue on repairing full-thickness hyaline cartilage defects.Methods: Adipose-derived stem cells (ADSCs) were derived from adipose tissue and cultured in vitro.Twentyseven New Zealand white rabbits were divided into three groups randomly.The cultured ADSCs mixed with calcium alginate gel were used to fill the full-thickness hyaline cartilage defects created at the patellafemoral joint,and the defects repaired with gel or without treatment served as control groups.After 4,8 and 12 weeks,the reconstructed tissue was evaluated macroscopically and microscopically.Histological analysis and qualitative scoring were also performed to detect the outcome.Results: Full thickness hyaline cartilage defects were repaired completely with ADSCs-derived dssue.The result was better in ADSCs group than the control ones.The microstructure of reconstructed tissue with ADSCs was similar to that of hvaline cartilage and contained more cells and regular matrix fibers,being better than other groups.Plenty of collagen fibers around cells could be seen under transmission electron microscopy.Statistical analysis revealed a significant difference in comparison with other groups at each time point(t=4.360,P<0.01).Conclusion: Thcse results indicate that stem cells derived from mature adipose without induction possess the ability to repair cartilage defects

  11. Effect of PbS Film Thickness on the Performance of Colloidal Quantum Dot Solar Cells

    Directory of Open Access Journals (Sweden)

    M. Mazloum-Ardakani

    2013-03-01

    Full Text Available Colloidal quantum dots offer broad tuning of semiconductor band structure via the quantum size effect. In this paper, we present a detailed investigation on the influence of the thickness of colloidal lead sulfide (PbS nanocrystals (active layer to the photovoltaic performance of colloidal quantum dot solar cells. The PbS nanocrystals (QDs were synthesized in a non-coordinating solvent, 1-octadecene, using oleic acid (OA as the ligand. It was found that the device with 50 nm of thickness of active layer showed a high Efficiency (η of 0.667 under simulated Air Mass 1.5 Global (AM 1.5G irradiation (100 mW/cm2 compared  to the device with low thickness of active layer.

  12. A low-cost photovoltaic cell process based on thick film techniques

    Science.gov (United States)

    Mardesich, N.; Pepe, A.; Bunyan, S.; Edwards, B.; Olson, C.

    1980-01-01

    The low-cost, easily automated processing for solar cell fabrication being developed at Spectrolab for the DOE LSA program is described. These processes include plasma-etching, spray-on diffusion sources and antireflective coating, thick film metallization, aluminum back contacts, laser scribing and ultrasonic soldering. The process sequence has been shown to produce solar cells having 15% conversion efficiency at AM1 which meet the cell fabrication budget required for the DOE 1986 cost goal of $0.70 per peak watt in 1980.

  13. Effect of the quantum well thickness on the performance of InGaN photovoltaic cells

    Energy Technology Data Exchange (ETDEWEB)

    Redaelli, L.; Mukhtarova, A.; Valdueza-Felip, S.; Ajay, A.; Durand, C.; Eymery, J.; Monroy, E. [Université Grenoble Alpes, 38000 Grenoble (France); CEA-CNRS Group «Nanophysique et semiconducteurs», CEA-Grenoble, INAC/SP2M, 17 avenue des Martyrs, 38054 Grenoble cedex 9 (France); Bougerol, C.; Himwas, C. [Université Grenoble Alpes, 38000 Grenoble (France); CEA-CNRS Group «Nanophysique et semiconducteurs», Institut Néel-CNRS, 25 avenue des Martyrs, 38042 Grenoble cedex 9 (France); Faure-Vincent, J. [Université Grenoble Alpes, 38000 Grenoble (France); CNRS, INAC-SPRAM, F-38000 Grenoble (France); CEA, INAC-SPRAM, F-38000 Grenoble (France)

    2014-09-29

    We report on the influence of the quantum well thickness on the effective band gap and conversion efficiency of In{sub 0.12}Ga{sub 0.88}N/GaN multiple quantum well solar cells. The band-to-band transition can be redshifted from 395 to 474 nm by increasing the well thickness from 1.3 to 5.4 nm, as demonstrated by cathodoluminescence measurements. However, the redshift of the absorption edge is much less pronounced in absorption: in thicker wells, transitions to higher energy levels dominate. Besides, partial strain relaxation in thicker wells leads to the formation of defects, hence degrading the overall solar cell performance.

  14. Membrane cell grafts, fresh and frozen to cover full thickness wounds in athymic nude mice

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    objective: To find a new way to cover full-thickness wounds. Methods: Biobrane(r), an adherent, flexible temporary wound dressing was incubated with cultured human keratinocytes. The cells adhered quickly forming "membrane-celgrafts" (MCG). Some of the grafts were frozen and after thawing viability was verified with a XTT colorimetric assay.MCGs, fresh and cryopreserved, were transplanted on full thickness wounds created on athymic nude mice. Conventional cultured epidermal grafts (CEG) and wounds without cell grafts served as control. Results: MCGs resulted in a differentiated epithelium of human phenotype and immunohistochemistry, immunofluorescence and electronmicroscopy were performed.Compared with CEG-grafted sites a reduced wound contraction was noticed and complete remodelling of the basement membrane zone was found. Conclusion: The efficiency of the easy, uncomplicated production, cryopreservation and use as well as the short culture period could lead to a new approach in the treatment of burn and chronic wounds.

  15. Compositional variation within thick (>10 m) flow units of Mauna Kea Volcano cored by the Hawaii Scientific Drilling Project

    Science.gov (United States)

    Huang, Shichun; Vollinger, Michael J.; Frey, Frederick A.; Rhodes, J. Michael; Zhang, Qun

    2016-07-01

    Geochemical analyses of stratigraphic sequences of lava flows are necessary to understand how a volcano works. Typically one sample from each lava flow is collected and studied with the assumption that this sample is representative of the flow composition. This assumption may not be valid. The thickness of flows ranges from 100 m. Geochemical heterogeneity in thin flows may be created by interaction with the surficial environment whereas magmatic processes occurring during emplacement may create geochemical heterogeneities in thick flows. The Hawaii Scientific Drilling Project (HSDP) cored ∼3.3 km of basalt erupted at Mauna Kea Volcano. In order to determine geochemical heterogeneities in a flow, multiple samples from four thick (9.3-98.4 m) HSDP flow units were analyzed for major and trace elements. We found that major element abundances in three submarine flow units are controlled by the varying proportion of olivine, the primary phenocryst phase in these samples. Post-magmatic alteration of a subaerial flow led to loss of SiO2, CaO, Na2O, K2O and P2O5, and as a consequence, contents of immobile elements, such as Fe2O3 and Al2O3, increase. The mobility of SiO2 is important because Mauma Kea shield lavas divide into two groups that differ in SiO2 content. Post-magmatic mobility of SiO2 adds complexity to determining if these groups reflect differences in source or process. The most mobile elements during post-magmatic subaerial and submarine alteration are K and Rb, and Ba, Sr and U were also mobile, but their abundances are not highly correlated with K and Rb. The Ba/Th ratio has been used to document an important role for a plagioclase-rich source component for basalt from the Galapagos, Iceland and Hawaii. Although Ba/Th is anomalously high in Hawaiian basalt, variation in Ba abundance within a single flow shows that it is not a reliable indicator of a deep source component. In contrast, ratios involving elements that are typically immobile, such as La/Nb, La

  16. Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina

    Science.gov (United States)

    Williams, Lester J.; Dixon, Joann F.

    2015-01-01

    Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part of the U.S. Geological Survey Groundwater Resources Program. The dataset contains structural surfaces depicting the top and base of the aquifer system, its major and minor hydrogeologic units and zones, geophysical marker horizons, and the altitude of the 10,000-milligram-per-liter total dissolved solids boundary that defines the approximate fresh and saline parts of the aquifer system. The thicknesses of selected major and minor units or zones were determined by interpolating points of known thickness or from raster surface subtraction of the structural surfaces. Additional data contained include clipping polygons; regional polygon features that represent geologic or hydrogeologic aspects of the aquifers and the minor units or zones; data points used in the interpolation; and polygon and line features that represent faults, boundaries, and other features in the aquifer system.

  17. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Polygon regions of the upper confining unit of the Floridan aquifer system

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  18. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Geologic units forming the base of the Floridan aquifer system

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  19. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Geologic units forming the top of the Floridan aquifer system

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  20. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Polygon regions depicting the low-permeability units that overlie the Lower Floridan aquifer

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  1. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Contours for top of the middle confining unit of the Floridan aquifer system

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  2. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Area where upper confining unit is thin or absent beneath the surficial aquifer

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  3. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Polygon regions of low-permeability units forming the MAPCU

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  4. Effect of Nanotube Film Thickness on the Performance of Nanotube-Silicon Hybrid Solar Cells

    Directory of Open Access Journals (Sweden)

    Daniel D. Tune

    2013-12-01

    Full Text Available The results of measurements on solar cells made from randomly aligned thin films of single walled carbon nanotubes (SWCNTs on n-type monocrystalline silicon are presented. The films are made by vacuum filtration from aqueous TritonX-100 suspensions of large diameter arc-discharge SWCNTs. The dependence of the solar cell performance on the thickness of the SWCNT film is shown in detail, as is the variation in performance due to doping of the SWCNT film with SOCl2.

  5. Effect of Substrate Thickness on Oxide Scale Spallation for Solid Oxide Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Wenning N.; Sun, Xin; Stephens, Elizabeth V.; Khaleel, Mohammad A.

    2011-07-01

    In this paper, the effect of the ferritic substrate's thickness on the delamination/spallation of the oxide scale was investigated experimentally and numerically. At the high-temperature oxidation environment of solid oxide fuel cells (SOFCs), a combination of growth stress with thermal stresses may lead to scale delamination/buckling and eventual spallation during SOFC stack cooling, even leading to serious degradation of cell performance. The growth stress is induced by the growth of the oxide scale on the scale/substrate interface, and thermal stress is induced by a mismatch of the coefficient of thermal expansion between the oxide scale and the substrate. The numerical results show that the interfacial shear stresses, which are the driving force of scale delamination between the oxide scale and the ferritic substrate, increase with the growth of the oxide scale and also with the thickness of the ferritic substrate; i.e., the thick ferritic substrate can easily lead to scale delamination and spallation. Experimental observation confirmed the predicted results of the delamination and spallation of the oxide scale on the ferritic substrate.

  6. High resolution spectroscopy of Cs vapor confined in optical cells of few-micron thicknesses

    Science.gov (United States)

    Cartaleva, S.; Krasteva, A.; Sargsyan, A.; Sarkisyan, D.; Slavov, D.; Vartanyan, T.

    2012-12-01

    We present here the new behavior of Electromagnetically Induced Transparency (EIT), Velocity Selective Optical Pumping (VSOP) and Velocity Selective Excitation (VSE) resonances observed in Cs vapor confined in unique cells with thicknesses L = 1.5λ and L = 6λ. It is shown experimentally that in both cells, the EIT resonance is significantly narrower than would be expected from the ground state dephasing rate due to atomic collisions with the cell windows. The enhanced absorption (fluorescence) narrow VSOP resonance at the closed transition transforms into reduced absorption (fluorescence) one with small increase of atomic concentration or light intensity. A striking difference appears between the VSE resonance broadening due to excited atom thermalization, in L = 6λ and conventional L = 2.5 cm cells.

  7. Microsystems enabled photovoltaics: 14.9% efficient 14 {mu}m thick crystalline silicon solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Cruz-Campa, Jose L. [Sandia National Laboratories, M.S. 1080, 1515 Eubank Blvd. SE, Albuquerque, NM 87123 (United States); University of Texas at El Paso, Department of Electrical and Computer Engineering, 500 West University Avenue, El Paso, TX 79968 (United States); Okandan, Murat; Resnick, Paul J.; Clews, Peggy; Pluym, Tammy; Grubbs, Robert K.; Gupta, Vipin P.; Nielson, Gregory N. [Sandia National Laboratories, M.S. 1080, 1515 Eubank Blvd. SE, Albuquerque, NM 87123 (United States); Zubia, David [University of Texas at El Paso, Department of Electrical and Computer Engineering, 500 West University Avenue, El Paso, TX 79968 (United States)

    2011-02-15

    Crystalline silicon solar cells 10-15 times thinner than traditional commercial c-Si cells with 14.9% efficiency are presented with modeling, fabrication, and testing details. These cells are 14 {mu}m thick, 250 {mu}m wide, and have achieved 14.9% solar conversion efficiency under AM 1.5 spectrum. First, modeling results illustrate the importance of high-quality passivation to achieve high efficiency in thin silicon, back contacted solar cells. Then, the methodology used to fabricate these ultra thin devices by means of established microsystems processing technologies is presented. Finally, the optimization procedure to achieve high efficiency as well as the results of the experiments carried out with alumina and nitride layers as passivation coatings are discussed. (author)

  8. A new clinical unit for digital radiography based on a thick amorphous Selenium plate: Physical and psychophysical characterization

    Energy Technology Data Exchange (ETDEWEB)

    Rivetti, Stefano; Lanconelli, Nico; Bertolini, Marco; Acchiappati, Domenico [Alma Mater Studiorum, Physics Department, University of Bologna, 40127 Bologna, Italy and S.C. di Fisica Sanitaria ' ' Azienda USL di Modena' ' 41100 Modena (Italy); Alma Mater Studiorum, Physics Department, University of Bologna, 40127 Bologna (Italy); Arcispedale Santa Maria Nuova, 42123 Reggio Emilia (Italy); S.C. di Fisica Sanitaria ' ' Azienda USL di Modena' ' 41100 Modena (Italy)

    2011-08-15

    Purpose: Here, we present a physical and psychophysical characterization of a new clinical unit (named AcSelerate) for digital radiography based on a thick a-Se layer. We also compared images acquired with and without a software filter (named CRF) developed for reducing sharpness and noise of the images and making them similar to images coming from traditional computed radiography systems. Methods: The characterization was achieved in terms of physical figures of merit [modulation transfer function (MTF), noise power spectra (NPS), detective quantum efficiency (DQE)], and psychophysical parameters (contrast-detail analysis with an automatic reading of CDRAD images). We accomplished measurements with four standard beam conditions: RAQ3, RQA5, RQA7, and RQA9. Results: The system shows an excellent MTF (about 50% at the Nyquist frequency). The DQE is about 55% at 0.5 lp/mm and above 20% at the Nyquist frequency and is almost independent from exposure. The contrast-detail curves are comparable to some of the best published data for other systems devoted to imaging in general radiography. The CRF filter influences both the MTF and NPS, but it does lead to very small changes on DQE. Also the visibility of CDRAD details is basically unaltered, when the filter is activated. Conclusions: As normally happens with detector based on direct conversion, the system presents an excellent MTF. The improved efficiency caused by the thick layer allows getting good noise characteristics and DQE results better (about 10% on average) than many of the computed radiography (CR) systems and comparable to those obtained by the best systems for digital radiography available on the market.

  9. Heme oxygenase attenuates angiotensin II-mediated superoxide production in cultured mouse thick ascending loop of Henle cells.

    Science.gov (United States)

    Kelsen, Silvia; Patel, Bijal J; Parker, Lawson B; Vera, Trinity; Rimoldi, John M; Gadepalli, Rama S V; Drummond, Heather A; Stec, David E

    2008-10-01

    Heme oxygenase (HO)-1 induction can attenuate the development of angiotensin II (ANG II)-dependent hypertension. However, the mechanism by which HO-1 lowers blood pressure is not clear. The goal of this study was to test the hypothesis that induction of HO-1 can reduce the ANG II-mediated increase in superoxide production in cultured thick ascending loop of Henle (TALH) cells. Studies were performed on an immortalized cell line of mouse TALH (mTALH) cells. HO-1 was induced in cultured mTALH cells by treatment with cobalt protoporphyrin (CoPP, 10 microM) or hemin (50 microM) or by transfection with a plasmid containing the human HO-1 isoform. Treatment of mTALH cells with 10(-9) M ANG II increased dihydroethidium (DHE) fluorescence (an index of superoxide levels) from 35.5+/-5 to 136+/-18 relative fluorescence units (RFU)/microm2. Induction of HO-1 via CoPP, hemin, or overexpression of the human HO-1 isoform significantly reduced ANG II-induced DHE fluorescence to 64+/-5, 64+/-8, and 41+/-4 RFU/microm2, respectively. To determine which metabolite of HO-1 is responsible for reducing ANG II-mediated increases in superoxide production in mTALH cells, cells were preincubated with bilirubin or carbon monoxide (CO)-releasing molecule (CORM)-A1 (each at 100 microM) before exposure to ANG II. DHE fluorescence averaged 80+/-7 RFU/microm2 after incubation with ANG II and was significantly decreased to 55+/-7 and 53+/-4 RFU/microm2 after pretreatment with bilirubin and CORM-A1. These results demonstrate that induction of HO-1 in mTALH cells reduces the levels of ANG II-mediated superoxide production through the production of both bilirubin and CO.

  10. Alignment of muscle precursor cells on the vertical edges of thick carbon nanotube films.

    Science.gov (United States)

    Holt, Ian; Gestmann, Ingo; Wright, Andrew C

    2013-10-01

    The development of scaffolds and templates is an essential aspect of tissue engineering. We show that thick (>0.5 mm) vertically aligned carbon nanotube films, made by chemical vapour deposition, can be used as biocompatible substrates for the directional alignment of mouse muscle cells where the cells grow on the exposed sides of the films. Ultra high resolution scanning electron microscopy reveals that the films themselves consist mostly of small diameter (10 nm) multi-wall carbon nanotubes of wavy morphology with some single wall carbon nanotubes. Our findings show that for this alignment to occur the nanotubes must be in pristine condition. Mechanical wiping of the films to create directional alignment is detrimental to directional bioactivity. Larger areas for study have been formed from a composite of multiply stacked narrow strips of nanotubes wipe-transferred onto elastomer supports. These composite substrates appear to show a useful degree of alignment of the cells.

  11. Light Trapping Textures Designed by Electromagnetic Optimization for Sub-Wavelength Thick Solar Cells

    CERN Document Server

    Ganapati, Vidya; Yablonovitch, Eli

    2013-01-01

    Light trapping in solar cells allows for increased current and voltage, as well as reduced materials cost. It is known that in geometrical optics, a maximum 4n^2 absorption enhancement factor can be achieved by randomly texturing the surface of the solar cell, where n is the material refractive index. This ray-optics absorption enhancement limit only holds when the thickness of the solar cell is much greater than the optical wavelength. In sub-wavelength thin films, the fundamental questions remain unanswered: (1) what is the sub-wavelength absorption enhancement limit and (2) what surface texture realizes this optimal absorption enhancement? We turn to computational electromagnetic optimization in order to design nanoscale textures for light trapping in sub-wavelength thin films. For high-index thin films, in the weakly absorbing limit, our optimized surface textures yield an angle- and frequency-averaged enhancement factor ~39. They perform roughly 30% better than randomly textured structures, but they fall...

  12. Microfabricated rubidium vapour cell with a thick glass core for small-scale atomic clock applications

    Science.gov (United States)

    Pétremand, Y.; Affolderbach, C.; Straessle, R.; Pellaton, M.; Briand, D.; Mileti, G.; de Rooij, N. F.

    2012-02-01

    This paper presents a new fabrication method to manufacture alkali reference cells having dimensions larger than standard micromachined cells and smaller than glass-blown ones, for use in compact atomic devices such as vapour-cell atomic clocks or magnetometers. The technology is based on anodic bonding of silicon and relatively thick glass wafers and fills a gap in cell sizes and technologies available up to now: on one side, microfabrication technologies with typical dimensions ≤ 2 mm and on the other side, classical glass-blowing technologies for typical dimensions of about 6-10 mm or larger. The fabrication process is described for cells containing atomic Rb and spectroscopic measurements (optical absorption spectrum and double resonance) are reported. The analysis of the bonding strength of our cells was performed and shows that the first anodic bonding steps exhibit higher bonding strengths than the later ones. The spectroscopic results show a good quality of the cells. From the double-resonance signals, we predict a clock stability of ≈3 × 10-11 at 1 s of integration time, which compares well to the performance of compact commercial Rb atomic clocks.

  13. Frequency Selective Surfaces with Nanoparticles Unit Cell

    Directory of Open Access Journals (Sweden)

    Nga Hung Poon

    2015-09-01

    Full Text Available The frequency selective surface (FSS is a periodic structure with filtering performance for optical and microwave signals. The general periodic arrays made with patterned metallic elements can act as an aperture or patch on a substrate. In this work, two kinds of materials were used to produce unit cells with various patterns. Gold nanoparticles of 25 nm diameter were used to form periodic monolayer arrays by a confined photocatalytic oxidation-based surface modification method. As the other material, silver gel was used to create multiple layers of silver. Due to the ultra-thin nature of the self-assembled gold nanoparticle monolayer, it is very easy to penetrate the FSS with terahertz radiation. However, the isolated silver islands made from silver gel form thicker multiple layers and contribute to much higher reflectance. This work demonstrated that multiple silver layers are more suitable than gold nanoparticles for use in the fabrication of FSS structures.

  14. Altering Anode Thickness To Improve Power Production in Microbial Fuel Cells with Different Electrode Distances

    KAUST Repository

    Ahn, Yongtae

    2013-01-17

    A better understanding of how anode and separator physical properties affect power production is needed to improve energy and power production by microbial fuel cells (MFCs). Oxygen crossover from the cathode can limit power production by bacteria on the anode when using closely spaced electrodes [separator electrode assembly (SEA)]. Thick graphite fiber brush anodes, as opposed to thin carbon cloth, and separators have previously been examined as methods to reduce the impact of oxygen crossover on power generation. We examined here whether the thickness of the anode could be an important factor in reducing the effect of oxygen crossover on power production, because bacteria deep in the electrode could better maintain anaerobic conditions. Carbon felt anodes with three different thicknesses were examined to see the effects of thicker anodes in two configurations: widely spaced electrodes and SEA. Power increased with anode thickness, with maximum power densities (604 mW/m 2, 0.32 cm; 764 mW/m2, 0.64 cm; and 1048 mW/m2, 1.27 cm), when widely spaced electrodes (4 cm) were used, where oxygen crossover does not affect power generation. Performance improved slightly using thicker anodes in the SEA configuration, but power was lower (maximum of 689 mW/m2) than with widely spaced electrodes, despite a reduction in ohmic resistance to 10 Ω (SEA) from 51-62 Ω (widely spaced electrodes). These results show that thicker anodes can work better than thinner anodes but only when the anodes are not adversely affected by proximity to the cathode. This suggests that reducing oxygen crossover and improving SEA MFC performance will require better separators. © 2012 American Chemical Society.

  15. Lithium-Ion Cell Charge-Control Unit Developed

    Science.gov (United States)

    Reid, Concha M.; Manzo, Michelle A.; Buton, Robert M.; Gemeiner, Russel

    2005-01-01

    A lithium-ion (Li-ion) cell charge-control unit was developed as part of a Li-ion cell verification program. This unit manages the complex charging scheme that is required when Li-ion cells are charged in series. It enables researchers to test cells together as a pack, while allowing each cell to charge individually. This allows the inherent cell-to-cell variations to be addressed on a series string of cells and reduces test costs substantially in comparison to individual cell testing.

  16. Novel negative mass density resonant metamaterial unit cell

    Energy Technology Data Exchange (ETDEWEB)

    Cselyuszka, Norbert, E-mail: cselyu@yahoo.com; Sečujski, Milan, E-mail: secujski@uns.ac.rs; Crnojević-Bengin, Vesna, E-mail: bengin@uns.ac.rs

    2015-01-02

    In this paper a novel resonant unit cell of one-dimensional acoustic metamaterials is presented, which exhibits negative effective mass density. We theoretically analyze the unit cell and develop a closed analytical formula for its effective mass density. Then we proceed to demonstrate left-handed propagation of acoustic waves using the proposed unit cell. Finally, we present its dual-band version, capable of operating at two independent frequencies. - Highlights: • A novel acoustic metamaterial unit cell provides Lorentz-type resonant effective mass density. • Analytical formula for effective mass density is derived. • Acoustic bandstop medium and left-handed metamaterial based on the novel unit cell are presented. • Modified version of the unit cell, operating at two independent frequencies, is proposed.

  17. Efficiency enhancement in solid state dye sensitized solar cells by including inverse opals with controlled layer thicknesses

    Science.gov (United States)

    Zheng, Hanbin; Shah, Said Karim; Abbas, Mamatimin; Ly, Isabelle; Rivera, Thomas; Almeida, Rui M.; Hirsch, Lionel; Toupance, Thierry; Ravaine, Serge

    2016-09-01

    The photoconversion efficiency of dye sensitized solar cells can be enhanced by the incorporation of light management nanostructures such as photonic crystals. Here, we present a facile route to incorporate titania inverse opals into solid state dye sensitized solar cells and report photoconversion efficiency enhancements of up to 56% compared with a model system without the inverse opal. Our approach is based on the precise design of titania inverse opals with a predetermined thickness that can be controlled at the individual layer level. By choosing an inverse opal exhibiting a photonic bandgap which overlaps the absorption bands of the dye, our results show that there is an optimal thickness of the inverse opal structure for maximum efficiency enhancement of the cell. This is the first experimental proof that the thickness of a titania inverse opal plays a pivotal role in cell efficiency enhancement in solid state dye sensitized solar cells.

  18. Simulation Study of Effects, Operating Temperature and Layer Thickness on Thin Film CIGS Solar Cell Performance

    Directory of Open Access Journals (Sweden)

    A.D. Pogrebnjak

    2011-01-01

    Full Text Available SCAPS- program is designed basically for the simulation and studying the properties of photonic devices. We explored the important controllable design parameters affecting the performance of the hetero junction solar cells, as operating temperature that we noticed increasing in J-V characteristics by increasing T, the effect of thickness of each layer on the performance of the cell was studied, an increasing of J-V characteristics with increasing p-layer , In the numerical example, 3 μm absorber layer and CdS layer 0.05 μm, ZnO layer 0.1 μm, works the best for given doping density, if we change the optimum value , the efficiency can reach to 17.72 % with FF 83.88 %, Voc = 0.725 Volt, Jsc = 29.07 mA/cm2 at 300 K, in this case, we have come out the optimum parameters to achieve the best performance of this type of cell, and then to made comparison with practical CIGS cell.

  19. Stomatal crypts may facilitate diffusion of CO(2) to adaxial mesophyll cells in thick sclerophylls.

    Science.gov (United States)

    Hassiotou, Foteini; Evans, John R; Ludwig, Martha; Veneklaas, Erik J

    2009-11-01

    In some plants, stomata are exclusively located in epidermal depressions called crypts. It has been argued that crypts function to reduce transpiration; however, the occurrence of crypts in species from both arid and wet environments suggests that crypts may play another role. The genus Banksia was chosen to examine quantitative relationships between crypt morphology and leaf structural and physiological traits to gain insight into the functional significance of crypts. Crypt resistance to water vapour and CO(2) diffusion was calculated by treating crypts as an additional boundary layer partially covering one leaf surface. Gas exchange measurements of polypropylene meshes confirmed the validity of this approach. Stomatal resistance was calculated as leaf resistance minus calculated crypt resistance. Stomata contributed significantly more than crypts to leaf resistance. Crypt depth increased and accounted for an increasing proportion of leaf resistance in species with greater leaf thickness and leaf dry mass per area. All Banksia species examined with leaves thicker than 0.6 mm had their stomata in deep crypts. We propose that crypts function to facilitate CO(2) diffusion from the abaxial surface to adaxial palisade cells in thick leaves. This and other possible functions of stomatal crypts, including a role in water use, are discussed.

  20. Retinal nerve fiber layer and ganglion cell complex thickness in patients with type 2 diabetes mellitus

    Directory of Open Access Journals (Sweden)

    Mehmet Demir

    2014-01-01

    Full Text Available Aim: The aim of the following study is to evaluate the retinal nerve fiber layer (RNFL and ganglion cell complex (GCC thickness in patients with type 2 diabetes mellitus (DM. Materials and Methods: Average, inferior, and superior values of RNFL and GCC thickness were measured in 123 patients using spectral domain optical coherence tomography. The values of participants with DM were compared to controls. Diabetic patients were collected in Groups 1, 2 and 3. Group 1 = 33 participants who had no diabetic retinopathy (DR; Group 2 = 30 participants who had mild nonproliferative DR and Group 3 = 30 participants who had moderate non-proliferative DR. The 30 healthy participants collected in Group 4. Analysis of variance test and a multiple linear regression analysis were used for statistical analysis. Results: The values of RNFL and GCC in the type 2 diabetes were thinner than controls, but this difference was not statistically significant. Conclusions: This study showed that there is a nonsignificant loss of RNFL and GCC in patients with type 2 diabetes.

  1. Electrochemically active thickness of solid oxide fuel cell electrodes: Effectiveness model prediction

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Jin Hyun [School of Mechanical Engineering, Daegu University, Gyungsan (Korea, Republic of)

    2017-04-15

    The three-phase boundaries (TPBs) in the electrodes of solid oxide fuel cells (SOFCs) have different activity because of the distributed nature of the electrochemical reactions. The electrochemically active thickness (EAT) is a good measure to evaluate the extension of the active reaction zone into the electrode and the effective utilization of TPBs. In this study, an electrochemical reaction/charge conduction problem is formulated based on the Butler–Volmer reaction kinetics and then numerically solved to determine the EATs for the active electrode layers of SOFCs with various microstructural, dimensional, and property parameters. Thus, the EAT data and correlations presented in this study are expected to provide useful information for designing efficient electrodes of SOFCs.

  2. A living thick nanofibrous implant bifunctionalized with active growth factor and stem cells for bone regeneration

    Directory of Open Access Journals (Sweden)

    Eap S

    2015-02-01

    Full Text Available Sandy Eap,1,2,* Laetitia Keller,1–3,* Jessica Schiavi,1,2 Olivier Huck,1,2 Leandro Jacomine,4 Florence Fioretti,1,2 Christian Gauthier,4 Victor Sebastian,1,3,5 Pascale Schwinté,1,2 Nadia Benkirane-Jessel1,21INSERM, UMR 1109, Osteoarticular and Dental Regenerative Nanomedicine Laboratory, FMTS, Faculté de Médecine, Strasbourg, France; 2Faculté de Chirurgie Dentaire, Université de Strasbourg, Strasbourg, France; 3Department of Chemical Engineering, Aragon Nanoscience Institute, University of Zaragoza, Zaragoza, Spain; 4CNRS (National Center for Scientific Research, ICS (Charles Sadron Institute, Strasbourg, France; 5Networking Research Center of Bioengineering, Biomaterials and Nanomedicine, Zaragoza, Spain*These authors contributed equally to this workAbstract: New-generation implants focus on robust, durable, and rapid tissue regeneration to shorten recovery times and decrease risks of postoperative complications for patients. Herein, we describe a new-generation thick nanofibrous implant functionalized with active containers of growth factors and stem cells for regenerative nanomedicine. A thick electrospun poly(ε-caprolactone nanofibrous implant (from 700 µm to 1 cm thick was functionalized with chitosan and bone morphogenetic protein BMP-7 as growth factor using layer-by-layer technology, producing fish scale-like chitosan/BMP-7 nanoreservoirs. This extracellular matrix-mimicking scaffold enabled in vitro colonization and bone regeneration by human primary osteoblasts, as shown by expression of osteocalcin, osteopontin, and bone sialoprotein (BSPII, 21 days after seeding. In vivo implantation in mouse calvaria defects showed significantly more newly mineralized extracellular matrix in the functionalized implant compared to a bare scaffold after 30 days’ implantation, as shown by histological scanning electron microscopy/energy dispersive X-ray microscopy study and calcein injection. We have as well bifunctionalized our BMP-7

  3. Corneal endothelial cell density and morphology and central corneal thickness in Guangxi Maonan and Han adolescent students of China

    Institute of Scientific and Technical Information of China (English)

    Hao; Liang; Hui-Yi; Zuo; Jin-Mao; Chen; Jie; Cai; Yu-Zhua; Qin; Yu-Ping; Huang; Ying-Ying; Chen; Dong-Yong; Tang; Shao-Jian; Tan

    2015-01-01

    AIM: To investigate the corneal endothelial cell density and morphology and central corneal thickness in the Guangxi Maonan and Han adolescent students of China.METHODS: Noncontact specular microscope(Topcon SP3000 P, Tokyo, Japan) was performed in 133 adolescent students of Maonan nationality(M:F 54:79)and 105 adolescent students of Han nationality(M:F 50:55),5 to 20 y of age, who were randomly selected from 3schools in Huanjiang Maonan Autonomous County of Guangxi Zhuang Autonomous Region of China.Parameters studied included endothelial cell density,mean cell area, coefficient of variation in cell size,percentage hexagonality and central corneal thickness. RESULTS: Endothelial cell density, mean cell area,coefficient of variation in cell size, percentage hexagonality and central corneal thickness in the study population were(2969.50 ±253.93) cells/mm2,(339.23 ±29.44) μm2,(29.96 ±4.07) %,(64.58 ±9.41) % and(523.71 ±32.82) μm in Maonan and(2998.26 ±262.65) cells/mm2,(336.11±30.07) μm2,(29.89±5.03) %,(64.91±11.64) % and(524.39 ±33.15) μm in Han, respectively. No significant differences were observed in endothelial cell density,mean cell area, coefficient of variation in cell size,percentage hexagonality and central corneal thickness between Maonan and Han(P =0.615, 0.659, 0.528, 0.551,0.999). In Maonan and Han, we found age was negatively correlated with endothelial cell density and percentagehexagonality and positively correlated with mean cell area and coefficient of variation in cell size. Negative correlation was also found between central corneal thickness and age in Han, whereas no correlation was found in Maonan. CONCLUSION: There were no differences between Maonan and Han in corneal endothelial cell density and morphology and central corneal thickness. In these two nationalities, there were statistically significant decrease in endothelial cell density and percentage hexagonality with increasing age and statistically significant increase in

  4. Velocity anisotropy effect in pump-probe spectra of cesium in a micrometric thickness optical cell

    Science.gov (United States)

    Ghosh, P. N.; Mitra, S.; Ray, B.; Krasteva, A.; Slavov, D.; Todorov, P.; Cartaleva, S.

    2015-01-01

    The pump-probe spectra in a cell of micrometric thickness containing cesium vapor are reported. The line shape and nonlinear features observed in the case of fluorescence in the direction parallel to the cell windows and the transmission spectra observed along the propagation direction of the probe beam show considerable differences in the spectral profiles. We observed Electromagnetically Induced Transparency (EIT) and enhanced Velocity Selective Optical Pumping (VSOP) signals. Atoms moving nearly parallel to the windows and perpendicular to the collinear pump and probe beams will see much lower Doppler shift of incident frequencies and hence will lead to considerable narrowing of the Doppler background in the fluorescence spectra. The coherence decay rate is also low for such atoms as they do not meet with the cell walls. A theoretical model based on five level optical Bloch equations is used to simulate the spectra. The Doppler convolution includes all possible orientation of atomic velocities with respect to the laser beam direction. The simulated curves reproduce the observed sharp EIT peaks and enhanced broad VSOP signals for the closed probe transition in the fluorescence and absorption spectra. The observed effect of the light intensity and temperature change on the non-linear features is reproduced by the simulation.

  5. Effects of processing temperature on the thickness of CdS and the performance of CdTe solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Ferekides, C.S.; Tetali, B.; Marinskiy, D.; Marinskaya, S.; Morel, D. [Department of Electrical Engineering, Center for Clean Energy and Vehicles, University of South Florida, Tampa, Florida 33620 (United States)

    1997-02-01

    CdTe cells have been fabricated on soda lime glass substrates. The effect of the CdS thickness and CdTe deposition temperature on the spectral response (SR) and solar cell parameters has been studied. The CdTe deposition temperature has been found to be a key processing parameter in determining the extent of interdiffusion at the CdTe and CdS interface. When the deposition of CdTe is carried out at high temperatures a significant portion of the CdS films is {open_quotes}lost{close_quotes} due to interdiffusion which leads to enhancement of the blue response of the solar cells. Devices with identical blue response (400{endash}500 nm) have been fabricated even though the starting CdS thicknesses were different; the cells for which the starting CdS thickness was greater exhibited higher open-circuit voltages and fill factors. {copyright} {ital 1997 American Institute of Physics.}

  6. Thin film CdTe solar cells with an absorber layer thickness in micro- and sub-micrometer scale

    Science.gov (United States)

    Bai, Zhizhong; Yang, Jun; Wang, Deliang

    2011-10-01

    CdTe thin film solar cell with an absorber layer as thin as 0.5 μm was fabricated. An efficiency of 7.9% was obtained for a 1-μm-thick CdTe solar cell. An increased intensity of deep recombination states in the band gap, which was responsible for the reduced open-circuit voltage and fill factor for ultra-thin solar cells, was induced due to the not-well-developed polycrystalline CdTe microstructure and the CdS/CdTe heterojunction and the presence of Cu in the back contact. The experimental results presented in this study demonstrated that 1-μm-thick absorber layer is thick enough to fabricate CdTe solar cell with a decent efficiency.

  7. Analysis the macular ganglion cell complex thickness in monocular strabismic amblyopia patients by Fourier-domain OCT

    Directory of Open Access Journals (Sweden)

    Hong-Wei Deng

    2014-11-01

    Full Text Available AIM: To detect the macular ganglion cell complex thickness in monocular strabismus amblyopia patients, in order to explore the relationship between the degree of amblyopia and retinal ganglion cell complex thickness, and found out whether there is abnormal macular ganglion cell structure in strabismic amblyopia. METHODS: Using a fourier-domain optical coherence tomography(FD-OCTinstrument iVue®(Optovue Inc, Fremont, CA, Macular ganglion cell complex(mGCCthickness was measured and statistical the relation rate with the best vision acuity correction was compared Gman among 26 patients(52 eyesincluded in this study. RESULTS: The mean thickness of the mGCC in macular was investigated into three parts: centrial, inner circle(3mmand outer circle(6mm. The mean thicknesses of mGCC in central, inner and outer circle was 50.74±21.51μm, 101.4±8.51μm, 114.2±9.455μm in the strabismic amblyopia eyes(SAE, and 43.79±11.92μm,92.47±25.01μm, 113.3±12.88μm in the contralateral sound eyes(CSErespectively. There was no statistically significant difference among the eyes(P>0.05. But the best corrected vision acuity had a good correlation rate between mGcc thicknesses, which was better relative for the lower part than the upper part.CONCLUSION:There is a relationship between the amblyopia vision acuity and the mGCC thickness. Although there has not statistically significant difference of the mGCC thickness compared with the SAE and CSE. To measure the macular center mGCC thickness in clinic may understand the degree of amblyopia.

  8. Interplay of solvent additive concentration and active layer thickness on the performance of small molecule solar cells.

    Science.gov (United States)

    Love, John A; Collins, Samuel D; Nagao, Ikuhiro; Mukherjee, Subhrangsu; Ade, Harald; Bazan, Guillermo C; Nguyen, Thuc-Quyen

    2014-11-19

    A relationship between solvent additive concentration and active layer thickness in small-molecule solar cells is investigated. Specifically, the additive concentration must scale with the amount of semiconductor material and not as absolute concentration in solution. Devices with a wide range of active layers with thickness up to 200 nm can readily achieve efficiencies close to 6% when the right concentration of additive is used.

  9. A Unit Cell Laboratory Experiment: Marbles, Magnets, and Stacking Arrangements

    Science.gov (United States)

    Collins, David C.

    2011-01-01

    An undergraduate first-semester general chemistry laboratory experiment introducing face-centered, body-centered, and simple cubic unit cells is presented. Emphasis is placed on the stacking arrangement of solid spheres used to produce a particular unit cell. Marbles and spherical magnets are employed to prepare each stacking arrangement. Packing…

  10. Balechina and the new genus Cucumeridinium gen. nov. (Dinophyceae), unarmored dinoflagellates with thick cell coverings.

    Science.gov (United States)

    Gómez, Fernando; López-García, Purificación; Takayama, Haruyoshi; Moreira, David

    2015-12-01

    The genus Balechina (=subgenus Pachydinium) was established for heterotrophic gymnodinioid dinoflagellates with a thick cell covering. The type species, B. pachydermata (=Gymnodinium pachyderm-atum), showed numerous fine longitudinal striae, whereas B. coerulea (=G. coeruleum) showed ~24 prominent longitudinal surface ridges or furrows and a distinctive blue pigmentation. We have investigated the morphology and molecular phylogeny of these taxa and the species Gymnodinium cucumis, G. lira and G. amphora from the western Mediterranean, Brazil and Japan. Sudden contractions at the cingulum level were seen in B. pachydermata, which also showed a high morphological variability which included morphotypes that have been described as Amphidinium vasculum, G. amphora, G. dogielii and G. gracile sensu Kofoid and Swezy. Molecular phylogeny based on small subunit rRNA gene sequences revealed that Balechina coerulea, G. cucumis and G. lira formed a clade distantly related to the clade of the type species, B. pachydermata, and G. amphora. We propose the new genus Cucumeridinium for the species with longitudinal ridges and a circular apical groove (Cucumeridinium coeruleum comb. nov., C. lira comb. nov. and C. cucumis comb. nov.), and Gymnodinium canus and G. costatum are considered synonyms of C. coeruleum. The genus Balechina remains for the species with a double-layer cell covering, bossed surface with fine striae, and an elongated elliptical apical groove. At present, the genus is monotypic containing only B. pachydermata. © 2015 Phycological Society of America.

  11. Balechina and the New Genus Cucumeridinium Gen. Nov. (Dinophyceae), Unarmored Dinoflagellates with Thick Cell Coverings

    Science.gov (United States)

    Gómez, Fernando; López-García, Purificación; Takayama, Haruyoshi; Moreira, David

    2016-01-01

    The genus Balechina (=subgenus Pachydinium) was established for heterotrophic gymnodinioid dinoflagellates with a thick cell covering. The type species, B. pachydermata (=Gymnodinium pachydermatum), showed numerous fine longitudinal striae, whereas B. coerulea (=G. coeruleum) showed ~24 prominent longitudinal surface ridges or furrows and a distinctive blue pigmentation. We have investigated the morphology and molecular phylogeny of these taxa and the species Gymnodinium cucumis, G. lira and G. amphora from the western Mediterranean, Brazil and Japan. Sudden contractions at the cingulum level were seen in B. pachydermata, which also showed a high morphological variability which included morphotypes that have been described as Amphidinium vasculum, G. amphora, G. dogielii and G. gracile sensu Kofoid and Swezy. Molecular phylogeny based on small subunit rRNA gene sequences revealed that Balechina coerulea, G. cucumis and G. lira formed a clade distantly related to the clade of the type species, B. pachydermata, and G. amphora. We propose the new genus Cucumeridinium for the species with longitudinal ridges and a circular apical groove (Cucumeridinium coeruleum comb. nov., C. lira comb. nov. and C. cucumis comb. nov.), and Gymnodinium canus and G. costatum are considered synonyms of C. coeruleum. The genus Balechina remains for the species with a double-layer cell covering, bossed surface with fine striae, and an elongated elliptical apical groove. At present, the genus is monotypic containing only B. pachydermata. PMID:26987004

  12. Advantages of InGaN/GaN multiple quantum well solar cells with stepped-thickness quantum wells

    Institute of Scientific and Technical Information of China (English)

    Chen Xin; Zhao Bi-Jun; Ren Zhi-Wei; Tong Jin-Hui; Wang Xing-Fu; Zhuo Xiang-Jing; Zhang Jun

    2013-01-01

    InGaN/GaN multiple quantum well (MQW) solar cells with stepped-thickness quantum wells (SQW) are designed and grown by metal-organic chemical vapor deposition.The stepped-thickness quantum wells structure,in which the well thickness becomes smaller and smaller along the growth direction,reveals better crystalline quality and better spectral overlap with the solar spectrum.Consequently,the short-circuit current density (Jsc) and conversion efficiency of the solar cell are enhanced by 27.12% and 56.41% compared with the conventional structure under illumination of AM1.5G (100 mW/cm2).In addition,approaches to further promote the performance of InGaN/GaN multiple quantum well solar cells are discussed and presented.

  13. Approximately 800-nm-Thick Pinhole-Free Perovskite Films via Facile Solvent Retarding Process for Efficient Planar Solar Cells.

    Science.gov (United States)

    Yuan, Zhongcheng; Yang, Yingguo; Wu, Zhongwei; Bai, Sai; Xu, Weidong; Song, Tao; Gao, Xingyu; Gao, Feng; Sun, Baoquan

    2016-12-21

    Device performance of organometal halide perovskite solar cells significantly depends on the quality and thickness of perovskite absorber films. However, conventional deposition methods often generate pinholes within ∼300 nm-thick perovskite films, which are detrimental to the large area device manufacture. Here we demonstrated a simple solvent retarding process to deposit uniform pinhole free perovskite films with thicknesses up to ∼800 nm. Solvent evaporation during the retarding process facilitated the components separation in the mixed halide perovskite precursors, and hence the final films exhibited pinhole free morphology and large grain sizes. In addition, the increased precursor concentration after solvent-retarding process led to thick perovskite films. Based on the uniform and thick perovskite films prepared by this convenient process, a champion device efficiency up to 16.8% was achieved. We believe that this simple deposition procedure for high quality perovskite films around micrometer thickness has a great potential in the application of large area perovskite solar cells and other optoelectronic devices.

  14. Influence of CdTe thickness on structural and electrical properties of CdTe/CdS solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Salavei, A.; Rimmaudo, I. [Laboratory for Applied Physics, Department of Computer Science, University of Verona, Strada Le Grazie 15, 37134 Verona (Italy); Piccinelli, F. [Laboratorio di Chimica dello Stato Solido, DB, Univ. Verona, and INSTM, UdR Verona, Strada Le Grazie 15, 37134 Verona (Italy); Romeo, A., E-mail: alessandro.romeo@univr.it [Laboratory for Applied Physics, Department of Computer Science, University of Verona, Strada Le Grazie 15, 37134 Verona (Italy)

    2013-05-01

    Due to its high scalability and low production cost, CdTe solar cells have shown a very strong potential for large scale energy production. Although the number of modules produced could be limited by tellurium scarcity, it has been reported that reducing CdTe thickness down to 1.5 μm would solve this issue. There are, however, issues to be considered when reducing thickness, such as formation of pinholes, lower crystallization, and different possible effects on material diffusion within the interfaces. In this work, we present the study of CdTe solar cells fabricated by vacuum evaporation with different CdTe thicknesses. Several cells with a CdTe thickness ranging from 0.7 to 6 μm have been fabricated. The deposition process has been optimized accordingly and their physical and electrical properties have been studied. Thin cells show a different electrical behavior in terms of open circuit voltage and fill factor. Efficiencies range from 7% for thin CdTe cells to 13.5% for the standard thickness. - Highlights: ► Ultra thin CdTe absorbers have been prepared and studied. ► Grain size is depending on the CdTe thickness but spread in the grains increases. ► Lattice parameter is reduced only for ultra thin CdTe. ► The band gap reveals an intermixed CdTe absorber. ► The reason for lower efficiency of ultra thin CdTe is explained.

  15. Cellular mechanoadaptation to substrate mechanical properties: contributions of substrate stiffness and thickness to cell stiffness measurements using AFM.

    Science.gov (United States)

    Vichare, Shirish; Sen, Shamik; Inamdar, Mandar M

    2014-02-28

    Mechanosensing by adherent cells is usually studied by quantifying cell responses on hydrogels that are covalently linked to a rigid substrate. Atomic force microscopy (AFM) represents a convenient way of characterizing the mechanoadaptation response of adherent cells on hydrogels of varying stiffness and thickness. Since AFM measurements reflect the effective cell stiffness, therefore, in addition to measuring real cytoskeletal alterations across different conditions, these measurements might also be influenced by the geometry and physical properties of the substrate itself. To better understand how the physical attributes of the gel influence AFM stiffness measurements of cells, we have used finite element analysis to simulate the indentation of cells of various spreads resting on hydrogels of varying stiffness and thickness. Consistent with experimental results, our simulation results indicate that for well spread cells, stiffness values are significantly over-estimated when experiments are performed on cells cultured on soft and thin gels. Using parametric studies, we have developed scaling relationships between the effective stiffness probed by AFM and the bulk cell stiffness, taking cell and tip geometry, hydrogel properties, nuclear stiffness and cell contractility into account. Finally, using simulated mechanoadaptation responses, we have demonstrated that a cell stiffening response may arise purely due to the substrate properties. Collectively, our results demonstrate the need to take hydrogel properties into account while estimating cell stiffness using AFM indentation.

  16. Analysis of the interdigitated back contact solar cells:The n-type substrate lifetime and wafer thickness

    Institute of Scientific and Technical Information of China (English)

    张巍; 陈晨; 贾锐; 孙昀; 邢钊; 金智; 刘新宇; 刘晓文

    2015-01-01

    The n-type silicon integrated-back contact (IBC) solar cell has attracted much attention due to its high efficiency, whereas its performance is very sensitive to the wafer of low quality or the contamination during high temperature fab-rication processing, which leads to low bulk lifetimeτbulk. In order to clarify the influence of bulk lifetime on cell char-acteristics, two-dimensional (2D) TCAD simulation, combined with our experimental data, is used to simulate the cell performances, with the wafer thickness scaled down under variousτbulk conditions. The modeling results show that for the IBC solar cell with highτbulk, (such as 1 ms–2 ms), its open-circuit voltage Voc almost remains unchanged, and the short-circuit current density Jsc monotonically decreases as the wafer thickness scales down. In comparison, for the solar cell with lowτbulk (for instance,<500 µs) wafer or the wafer contaminated during device processing, the Voc increases monotonically but the Jsc first increases to a maximum value and then drops off as the wafer’s thickness decreases. A model combing the light absorption and the minority carrier diffusion is used to explain this phenomenon. The research results show that for the wafer with thinner thickness and high bulk lifetime, the good light trapping technology must be developed to offset the decrease in Jsc.

  17. From flat to nanostructured photovoltaics: balance between thickness of the absorber and charge screening in sensitized solar cells.

    Science.gov (United States)

    Boix, Pablo P; Lee, Yong Hui; Fabregat-Santiago, Francisco; Im, Sang Hyuk; Mora-Sero, Ivan; Bisquert, Juan; Seok, Sang Il

    2012-01-24

    Nanoporous metal oxide electrodes provide a high internal area for dye anchoring in dye-sensitized solar cells, but the thickness required to extinguish the solar photons also enhances recombination at the TiO(2)/electrolyte interface. The high extinction coefficient of inorganic semiconductor absorber should allow the reduction of the film thickness, improving the photovoltage. Here we study all-solid semiconductor sensitized solar cells, in the promising TiO(2)/Sb(2)S(3)/P3HT configuration. Flat and nanostructured cells have been prepared and analyzed, developing a cell performance model, based on impedance spectroscopy results, that allows us to determine the impact of the reduction of metal oxide film thickness on the operation of the solar cell. Decreasing the effective surface area toward the limit of flat samples produces a reduction in the recombination rate, increasing the open circuit potential, V(oc), while providing a significant photocurrent. However, charge compensation problems as a consequence of inefficient charge screening in flat cells increase the hole transport resistance, lowering severely the cell fill factor. The use of novel structures balancing recombination and hole transport will enhance solid sensitized cell performance.

  18. Nano-thick calcium oxide armed titanium: boosts bone cells against methicillin-resistant Staphylococcus aureus

    Science.gov (United States)

    Cao, Huiliang; Qin, Hui; Zhao, Yaochao; Jin, Guodong; Lu, Tao; Meng, Fanhao; Zhang, Xianlong; Liu, Xuanyong

    2016-02-01

    Since the use of systemic antibiotics for preventing acute biomaterial-associated infections (BAIs) may build up bacterial resistance and result in huge medical costs and unpredictable mortality, new precaution strategies are required. Here, it demonstrated that titanium armed with a nano-thick calcium oxide layer was effective on averting methicillin-resistant Staphylococcus aureus (MRSA) infections in rabbits. The calcium oxide layer was constructed by, firstly, injecting of metallic calcium into titanium via a plasma immersion ion implantation process, and then transforming the outer most surface into oxide by exposing to the atmosphere. Although the calcium oxide armed titanium had a relative low reduction rate (~74%) in growth of MRSA in vitro, it could markedly promote the osteogenic differentiation of bone marrow stem cells (BMSCs), restore local bone integration against the challenge of MRSA, and decrease the incidence of MRSA infection with a rate of 100% (compared to the titanium control). This study demonstrated for the first time that calcium, as one of the major elements in a human body, could be engineered to avert MRSA infections, which is promising as a safe precaution of disinfection for implantable biomedical devices.

  19. Theory of margination and cell-free layer thickness in blood flow

    Science.gov (United States)

    Graham, Michael

    2016-11-01

    A mechanistic model is developed to describe segregation in confined multicomponent suspensions such as blood during Couette or plane Poiseuille flow. We focus attention on the case of a binary suspension with a deformable primary component (e.g. red blood cells) that completely dominates the collision dynamics in the system. The model captures the phenomena of depletion layer formation and margination observed in confined multicomponent suspensions of deformable particles. The depletion layer thickness of the primary component is predicted to follow a master curve relating it in a specific way to confinement ratio and volume fraction. Results from experiments and detailed simulations with different parameters (flexibility, viscosity ratio, confinement) collapse onto this curve with only one adjustable parameter. In a binary suspension, several regimes of segregation arise, depending on the value of a "margination parameter" M. Most importantly, in both Couette and Poiseuille flows there is a critical value of M below which a sharp "drainage transition" occurs: one component is completely depleted from the bulk flow to the vicinity of the walls. Direct simulations also exhibit this transition as the size or flexibility ratio of the components changes.

  20. Non-Toxic Buffer Layers in Flexible Cu(In,GaSe2 Photovoltaic Cell Applications with Optimized Absorber Thickness

    Directory of Open Access Journals (Sweden)

    Md. Asaduzzaman

    2017-01-01

    Full Text Available Absorber layer thickness gradient in Cu(In1−xGaxSe2 (CIGS based solar cells and several substitutes for typical cadmium sulfide (CdS buffer layers, such as ZnS, ZnO, ZnS(O,OH, Zn1−xSnxOy (ZTO, ZnSe, and In2S3, have been analyzed by a device emulation program and tool (ADEPT 2.1 to determine optimum efficiency. As a reference type, the CIGS cell with CdS buffer provides a theoretical efficiency of 23.23% when the optimum absorber layer thickness was determined as 1.6 μm. It is also observed that this highly efficient CIGS cell would have an absorber layer thickness between 1 μm and 2 μm whereas the optimum buffer layer thickness would be within the range of 0.04–0.06 μm. Among all the cells with various buffer layers, the best energy conversion efficiency of 24.62% has been achieved for the ZnO buffer layer based cell. The simulation results with ZnS and ZnO based buffer layer materials instead of using CdS indicate that the cell performance would be better than that of the CdS buffer layer based cell. Although the cells with ZnS(O,OH, ZTO, ZnSe, and In2S3 buffer layers provide slightly lower efficiencies than that of the CdS buffer based cell, the use of these materials would not be deleterious for the environment because of their non-carcinogenic and non-toxic nature.

  1. Relationship between white matter hyperintensities and retinal nerve fiber layer, choroid, and ganglion cell layer thickness in migraine patients.

    Science.gov (United States)

    Iyigundogdu, Ilkin; Derle, Eda; Asena, Leyla; Kural, Feride; Kibaroglu, Seda; Ocal, Ruhsen; Akkoyun, Imren; Can, Ufuk

    2017-01-01

    Aim To compare the relationship between white matter hyperintensities (WMH) on brain magnetic resonance imaging and retinal nerve fiber layer (RNFL), choroid, and ganglion cell layer (GCL) thicknesses in migraine patients and healthy subjects. We also assessed the role of cerebral hypoperfusion in the formation of these WMH lesions. Methods We enrolled 35 migraine patients without WMH, 37 migraine patients with WMH, and 37 healthy control subjects examined in the Neurology outpatient clinic of our tertiary center from May to December 2015. RFNL, choroid, and GCL thicknesses were measured by optic coherence tomography. Results There were no differences in the RFNL, choroid, or GCL thicknesses between migraine patients with and without WMH ( p > 0.05). Choroid layer thicknesses were significantly lower in migraine patients compared to control subjects ( p thicknesses ( p > 0.05). Conclusions The 'only cerebral hypoperfusion' theory was insufficient to explain the pathophysiology of WMH lesions in migraine patients. In addition, the thinning of the choroid thicknesses in migraine patients suggests a potential causative role for cerebral hypoperfusion and decreased perfusion pressure of the choroid layer.

  2. Beta-cell function is associated with carotid intima-media thickness independently of insulin resistance in healthy individuals

    DEFF Research Database (Denmark)

    Roussel, Ronan; Natali, Andrea; Balkau, Beverley

    2016-01-01

    ultrasound. Results: Intima-media thickness (IMT) in the common carotid artery was negatively associated with insulin secretion indexes, with Spearman partial correlation coefficients: -0.09, -0.08, -0.06 for respectively, the disposition index, the early insulin response and the beta cell glucose...

  3. Non-destructive lateral mapping of the thickness of the photoactive layer in polymer-based solar cells

    DEFF Research Database (Denmark)

    Sylvester-Hvid, Kristian O.; Tromholt, Thomas; Jørgensen, Mikkel

    2013-01-01

    Non-destructive lateral mapping of the thickness of the photoactive layer in poly(3-hexyl-thiophene) : 1-(3-methoxy-carbonyl)propyl-1-phenyl-(6,6)C61 (P3HT : PCBM) solar cells is demonstrated. The method employs a spatially resolved (XY) recording of ultraviolet-visible spectra in reflection...

  4. Copper iodide as inorganic hole conductor for perovskite solar cells with different thickness of mesoporous layer and hole transport layer

    Science.gov (United States)

    Huangfu, Minzan; Shen, Yue; Zhu, Gongbo; Xu, Kai; Cao, Meng; Gu, Feng; Wang, Linjun

    2015-12-01

    This study is the first to report the preparation of Copper iodide (CuI) thick films by means of convenient airbrush process and their application as inorganic hole transport layers (HTL) in organo-lead halide perovskite-based solar cells. CuI thick films exhibit high conductivity, wide-band-gap and solution-processable. Organo-lead halide perovskite solar cells with different thickness of mesoporous layers and CuI hole transport layers were fabricated. Performance of the cells were mainly controlled by the thickness of TiO2 mesoporous layers. Under optimized conditions, a power conversion efficiency of 5.8% has been achieved with short-circuit current density JSC of 22.3 mA/cm2, open-circuit voltage VOC of 614 mV and fill factor of 42%. However, the VOC remains low in comparison with the state of the art perovskite-based solar cells, which is attributed to the high recombination in CuI devices as determined by impedance spectroscopy.

  5. Influence of the thickness of the capacitive layer on the performance of bioanodes in Microbial Fuel Cells

    NARCIS (Netherlands)

    Deeke, A.; Sleutels, T.H.J.A.; Heijne, ter A.; Hamelers, H.V.M.; Buisman, C.J.N.

    2013-01-01

    Earlier it was shown, that it is possible to operate a Microbial Fuel Cell with an integrated capacitive bio-anode with a thickness of 0.5 mm and thereby to increase the power output. The integrated capacitive bioanode enabled storage of electricity produced by microorganisms directly inside an MFC.

  6. The cytosolic chloride concentration in macula densa and cortical thick ascending limb cells.

    Science.gov (United States)

    Salomonsson, M; Gonzalez, E; Kornfeld, M; Persson, A E

    1993-03-01

    It is believed that chloride transport through the macula densa (MD) cells is a factor involved in the tubuloglomerular feedback (TGF) mechanism and in MD-mediated renin release. In this study isolated and perfused rabbit kidney cortical thick ascending limb (cTAL) segments containing MD plaques and attached glomeruli were loaded with chloride (CL-sensitive) 6 methoxy-1-fluorophore (sulphanate-propyl) quinolinium (SPQ). MD and cTAL intracellular chloride concentration ([Cl-]i) was determined by using image-intensified video microscopy and digital image-processing for measuring the intensity of the emitted SPQ fluorescence. With 150 mM NaCl in lumen and bath the [Cl-]i in MD and cTAL cells was 58.8 +/- 7.2 mM (n = 20) and 68.7 +/- 9.8 mM (n = 14), respectively. When the presumed luminal Na(+)-2Cl(-)-K+ co-transporter was blocked by adding 10(-4)M furosemide, the [Cl-]i was reduced in both, MD and cTAL cells from 55.5 +/- 11.9 to 28.6 +/- 10.0 mM (n = 10) and from 43.8 +/- 2.6 to 13.1 +/- 4.5 mM (n = 5), respectively. A reduction in luminal NaCl from 150 to 30 mM also decreased both, MD and cTAL [Cl-]i from 69.4 +/- 9.1 to 36.5 +/- 5.1 mM (n = 9) and from 82.9 +/- 14.5 to 49.4 +/- 8.0 mM (n = 8), respectively. Basolateral addition of the Cl(-)-channel blocker NPPB increased MD [Cl-]i from 31.1 +/- 2.0 to 100.7 +/- 17.0 mM (n = 5) and cTAL [Cl-]i from 44.4 +/- 12.9 to 89.7 +/- 11.7 mM (n = 5).(ABSTRACT TRUNCATED AT 250 WORDS)

  7. Effect of the thickness of sputtered gadolinia-doped ceria as a cathodic interlayer in solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Park, Taehyun; Lee, Yoon Ho; Cho, Gu Young [School of Mechanical and Aerospace Engineering, Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul 151-744 (Korea, Republic of); Ji, Sanghoon [Graduate School of Convergence Science and Technology, Seoul National University, 864-1 Iui-dong, Yeongtong-gu, Suwon 443-270 (Korea, Republic of); Park, Joonho [School of Mechanical and Aerospace Engineering, Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul 151-744 (Korea, Republic of); Chang, Ikwhang [Graduate School of Convergence Science and Technology, Seoul National University, 864-1 Iui-dong, Yeongtong-gu, Suwon 443-270 (Korea, Republic of); Cha, Suk Won, E-mail: swcha@snu.ac.kr [School of Mechanical and Aerospace Engineering, Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul 151-744 (Korea, Republic of); Graduate School of Convergence Science and Technology, Seoul National University, 864-1 Iui-dong, Yeongtong-gu, Suwon 443-270 (Korea, Republic of)

    2015-06-01

    Sputtered gadolinia-doped ceria (GDC) film was introduced as the cathodic interlayer between an yttria-stabilized zirconia (YSZ) pellet and a Pt cathode in solid oxide fuel cells (SOFCs). The fuel cells with none, 50, 100 and 150 nm thick GDC interlayers were fabricated to investigate the effect of the thickness of the GDC interlayer. The performances of the SOFCs with the 100 and 150 nm thick GDC interlayers operated at 450 °C showed the highest performance. Through electrochemical impedance analysis, it was visualized that the GDC interlayer significantly reduced the faradaic resistance of the SOFC. The degradation of the performance from the increased ohmic resistance by adding the GDC interlayer was negligible. From the topographical images scanned by atomic force microscope, it was observed that the 50 nm thick GDC interlayer did not perfectly cover the surface of the YSZ pellet, resulting in incomplete performance enhancement by the sputtered GDC. - Highlights: • Gadolinia-doped ceria was used as a cathodic interlayer in solid oxide fuel cells. • Sputter was used to deposit gadolinia-doped ceria. • Gadolinia-doped ceria interlayer improved the electrochemical performance. • 100 nm or thicker gadolinia-doped ceria showed a full functionality as interlayer.

  8. A case report of spindle cell myoepithelioma with extensive lipomatous metaplasia and thick collagen bundles in the submandibular gland.

    Science.gov (United States)

    Kwon, Mi Jung; Kim, Hye Jeong; Park, Bumjung; Cho, Seong Jin; Shin, Hyung Sik; Park, Hye-Rim; Min, Soo Kee; Seo, Jinwon; Min, Kyueng-Whan; Nam, Eun Sook

    2016-09-01

    Spindle cell myoepithelioma with extensive lipomatous metaplasia and thick collagen bundles has not yet been described, and there are no published reports on its cytological appearance in fine-needle aspiration (FNA). A 49-year-old man presented with a painless mass in the right submandibular area that had been gradually enlarging for a period of 5 years. The cytologic smears showed fascicles of cohesive spindle cells as well as individual bland cells with bipolar naked nuclei in a fibrillary background. Brightly eosinophilic bundles were intermingled with spindle cells and fat-like vacuoles. The FNA results were suggestive of neurogenic tumor. Patient underwent submandibular gland resection. Grossly, the cut surface showed a well-encapsulated, yellowish-white, soft, elastic mass, measuring 2.8 × 1.9 × 1.5 cm. The tumor consisted of uniform bland spindle cells arranged in short fascicles admixed with adipocyte-like cells and transversing thick collagen bundles, which demonstrated immunoreactivity for myoepithelial markers and ultrastructural features characteristic of myoepithelial cells, suggesting the presence of lipomatous metaplasia. The FNA cytology of spindle cell myoepithelioma with extensive lipometaplasia mimicked that of neurogenic tumor or lipomatous mesenchymal tumor. This case represents the first description of submandibular gland myoepithelioma with lipometaplasia, which is characterized by the coexistence of spindle cells, collagen bundles, and fat-like vacuoles in a fibrillary background. Diagn. Cytopathol. 2016;44:764-769. © 2016 Wiley Periodicals, Inc.

  9. Numerical study of the influence of ZnTe thickness on CdS/ZnTe solar cell performance

    Science.gov (United States)

    Skhouni, Othmane; El Manouni, Ahmed; Mari, Bernabe; Ullah, Hanif

    2016-05-01

    At present most of II-VI semiconductor based solar cells use the CdTe material as an absorber film. The simulation of its performance is realized by means of various numerical modelling programs. We have modelled a solar cell based on zinc telluride (ZnTe) thin film as absorber in substitution to the CdTe material, which contains the cadmium element known by its toxicity. The performance of such photovoltaic device has been numerically simulated and the thickness of the absorber layer has been optimized to give the optimal conversion efficiency. A photovoltaic device consisting of a ZnTe layer as absorber, CdS as the buffer layer and ZnO as a window layer was modelled through Solar Cell Capacitance Simulator Software. Dark and illuminated I-V characteristics and the results for different output parameters of ZnO/CdS/ZnTe solar cell were analyzed. The effect of ZnTe absorber thickness on different main working parameters such as: open-circuit voltage Voc, short-circuit current density Jsc, fill factor FF, photovoltaic conversion efficiency η was intensely studied in order to optimize ZnTe film thickness. This study reveals that increasing the thickness of ZnTe absorber layer results in higher efficiency until a maximum value and then decreases slightly. This maximum was found to be 10% at ZnTe optimum thickness close to 2 µm. Contribution to the topical issue "Materials for Energy Harvesting, Conversion and Storage (ICOME 2015) - Elected submissions", edited by Jean-Michel Nunzi, Rachid Bennacer and Mohammed El Ganaoui

  10. Choroidal and Ganglion Cell Complex Thicknesses in Subjects with Type A Behavior Pattern: An Optical Coherence Tomography Study

    Directory of Open Access Journals (Sweden)

    Gulizar Demirok

    2014-11-01

    Full Text Available Aim: To evaluate choroidal thickness (CT and ganglion cell complex (GCC thickness with spectral domain optical coherence tomography (SD-OCT in subjects with type A behavior pattern (TABP. Material and Method: Thirty-eight eyes of 38 healthy controls and 38 eyes of 38 patients with TABP were enrolled. Each subject underwent a complete ophthalmic examination before SD-OCT images were obtained. Choroidal thicknesses were measured manually at the central of fovea (subfoveal and 500 µm intervals up to 1500 µm temporal (T1, T2, T3 and nasal (N1, N2, N3 to the fovea with Enhanced Depth Imaging (EDI mode. GCC thickness was evaluated automatically as the minimum and the average thicknesses. Parameters were compared between the groups. Results: The mean ages were 38.7±13.8 years in TABP group, and 40.3±11.5 years in control group. There were no significant differences in mean age, gender distribution, intraocular pressure and spherical equivalent between the groups (p>0.05. The mean (±SD CT for each of the 7 points (subfoveal, N1, N2, N3, T1, T2, T3 in TABP group were 325.4±45.1, 301.3±39.4, 284.6±35.2, 269.5±41.9, 293.2±40.7, 274.5±43.8, 260.5±44.3 µm, respectively. CT values in control group were 322.9±27.9, 301.8±33.2, 288.5±35.0, 278.1±33.4, 297.2±31.5, 285.1±33.0, 271.4±39.5 µm, respectively. There was no significant differences in CT for all 7 points between the groups (p>0,05. The mean and minimum GCC thicknesses in TABP group were 82.2±5.3 µm and 79.0±6.4 µm, respectively. Corresponding values in control group were 86.3±7.2 µm and 83.5±6.0 µm, respectively. There were significant differences in mean and minimum GCC thicknesses between the groups (p>0,05. Discussion: Although no detectable difference between the groups in terms of CT, the mean and minimum GCC thickness values of TABP patients were statistically lower than control group. TABP may be accompanied with a decrease of ganglion cell thickness.\

  11. Effects of ITO precursor thickness on transparent conductive Al doped ZnO film for solar cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Dong-Won; Kuk, Seung-Hee; Han, Min-Koo [School of Electrical Engineering, Seoul National University, Gwanak-gu, Seoul 151-742 (Korea, Republic of); Ji, Kwang-Sun; Lee, Heon-Min [LG Electronics, 16 Woomyeon-Dong Seocho-Gu, Seoul (Korea, Republic of)

    2011-01-15

    Al doped ZnO (AZO) film was continuously deposited on ITO precursor on glass substrate by d.c. magnetron sputtering. The thickness of ITO was varied from 30 to 120 nm in order to investigate the effect of ITO thickness on crystallinity of AZO film. X-ray diffraction measurement shows that AZO film grown on ITO has an enhanced (0 0 2) preferred orientation as the ITO thickness was increased. The crystalline structure improvement of AZO film with an increase of ITO precursor thickness is due to the near-epitaxial growth of AZO on ITO precursor. As the ITO thickness was increased, mobility of AZO film by the Hall measurement was significantly increased from 5.4 cm{sup 2}/V s (no ITO) to 23.6 cm{sup 2}/V s (ITO 120 nm), and resistivity was about 81.7% improved from 1.99 x 10{sup -3} to 3.63 x 10{sup -4} {omega} cm. The AZO films with ITO revealed excellent average transmission of visible (90.0%) and NIR (89.6%) regions, whereas those of AZO film without ITO were 82.1% and 88.1%, respectively. The haze values of AZO film with ITO of 90 and 120 nm are similar or higher than those of AZO film without ITO. The surface textured AZO film with ITO precursor is promising for optoelectronic applications such as the front TCO of thin film solar cells. (author)

  12. Fabrication and characteristics of unit cell for SOFC

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Gwi-Yeol; Eom, Seung-Wook; Moon, Seong-In [Korea Electrotechnology Research Institute, Kyongnam (Korea, Republic of)] [and others

    1996-12-31

    Research and development on solid oxide fuel cells in Korea have been mainly focused on unit cell and small stack. Fuel cell system is called clean generation system which not cause NOx or SOx. It is generation efficiency come to 50-60% in contrast to 40% of combustion generation system. Among the fuel cell system, solid oxide fuel cell is constructed of ceramics, so stack construction is simple, power density is very high, and there are no corrosion problems. The object of this study is to develop various composing material for SOFC generation system, and to test unit cell performance manufactured. So we try to present a guidance for developing mass power generation system. We concentrated on development of manufacturing process for cathode, anode and electrolyte.

  13. Wound healing from dermal grafts containing CD34+ cells is comparable to split-thickness skin micrografts

    DEFF Research Database (Denmark)

    Nuutila, Kristo; Singh, Mansher; Kruse, Carla

    2017-01-01

    BACKGROUND:: Epidermal stem cells present in the skin appendages of the dermis might be crucial in wound healing. In this study we located these cells in the dermis and evaluated their contribution to full-thickness wound healing in a porcine model. METHODS:: Four sequentially deeper 0.35mm thick...... skin grafts were harvested from the same donor site going down to 1.4 mm in depth (Layers 1-4). The layers were minced to 0.8 x 0.8 x 0.35 mm micrografts and transplanted (1:2) onto full-thickness porcine wounds. Healing was monitored up to 28 days and biopsies were collected on days 6 and 10. Multiple...... wound healing parameters were used to assess the quality of healing. RESULTS:: Our results showed that wounds transplanted with Layer 2 (0.35-0.7 mm) and 3 (0.7-1.05 mm) micrografts demonstrated comparable re-epithelialization rate as split-thickness skin graft (Layer 1- 0.00-0.35 mm; STSG) at day 10...

  14. Retina ganglion cell/inner plexiform layer and peripapillary nerve fiber layer thickness in patients with acromegaly.

    Science.gov (United States)

    Şahin, Muhammed; Şahin, Alparslan; Kılınç, Faruk; Yüksel, Harun; Özkurt, Zeynep Gürsel; Türkcü, Fatih Mehmet; Pekkolay, Zafer; Soylu, Hikmet; Çaça, İhsan

    2017-06-01

    Increased secretion of growth hormone and insulin-like growth factor-1 in acromegaly has various effects on multiple organs. However, the ocular effects of acromegaly have yet to be investigated in detail. The aim of the present study was to compare retina ganglion cell/inner plexiform layer (GCIPL) and peripapillary nerve fiber layer thickness (pRNFL) between patients with acromegaly and healthy control subjects using spectral domain optical coherence tomography (SD-OCT). This cross-sectional, comparative study included 18 patients with acromegaly and 20 control subjects. All participants underwent SD-OCT to measure pRNFL (in the seven peripapillary areas), GCIPL (in the nine ETDRS areas), and central macular thickness (CMT). Visual field (VF) examinations were performed using a Humphrey field analyzer in acromegalic patients. Measurements were compared between patients with acromegaly and control subjects. A total of 33 eyes of 18 patients with acromegaly and 40 eyes of 20 control subjects met the inclusion criteria of the present study. The overall calculated average pRNFL thickness was significantly lower in patients with acromegaly than in control subjects (P = 0.01), with pRNFL thickness significantly lower in the temporal superior and temporal inferior quadrants. Contrary to our expectations, pRNFL thickness in the nasal quadrant was similar between acromegalic and control subjects. The mean overall pRNFL thickness and superonasal, nasal, inferonasal, and inferotemporal quadrant pRNFL thicknesses were found to correlate with the mean deviation (MD) according to Spearman's correlation. However, other quadrants were not correlated with VF sensitivity. No significant difference in CMT values was observed (P = 0.6). GCIPL thickness was significantly lower in all quadrants of the inner and outer macula, except for central and inferior outer quadrants, in the acromegaly group than that in the control group (P acromegaly compared with that in control subjects

  15. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Raster surface for transmissivity of the Upper Floridan aquifer

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  16. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Polygon regions depicting saline areas within the Floridan aquifer system

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  17. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Extent of the sand-and-gravel aquifer of the surficial aquifer system

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  18. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina, Extent of the Woodville Karst Plain

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  19. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina, Frequency of closed depressions in relation to major springs in study area

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  20. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina - Positive structural features within the study area

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  1. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Extent lines for permeable zones of the intermediate aquifer system and Brunswick aquifer system

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  2. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Points for the top of the Floridan aquifer system

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  3. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Raster surface depicting the base of the Floridan aquifer system

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  4. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Point features used for the base of the Floridan aquifer system

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  5. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Polygon regions depicting saline areas for the APPZ

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  6. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Raster surface depicting the top of the APPZ

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  7. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Contours for the top of the APPZ

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  8. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Limestone boundary for the APPZ (Reese and Richardson, 2008)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  9. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Clipping boundary extent of the APPZ

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  10. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Contours for the top of the MAPCU

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  11. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Points where head differences were calculated across the MAPCU

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  12. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Raster surface depicting the top of the MAPCU

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  13. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Polygon extent of the BZ region of the Oldsmar permeable zone

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  14. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Points for the top of the MAPCU

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  15. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Polygon region depicting the weathered limestone residuum of the Floridan aquifer system

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  16. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Contours for the top of the LISAPCU

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  17. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Points for the top of the Lower Floridan aquifer below the LISAPCU, constrained

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  18. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- County boundaries for states represented in the study area

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  19. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Polygon regions depicting saline areas within the first permeable zone below the LISAPCU

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  20. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Contours for the top of the Lower Floridan aquifer

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  1. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Clipping boundary extent for the Oldsmar permeable zone

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  2. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Contours for the top of the Oldsmar permeable zone

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  3. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Raster surface depicting top of the Lower Floridan aquifer

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  4. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Points for the top of the glauconite marker horizon

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  5. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Extent of the Floridan aquifer system

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  6. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Polygon regions for the 10,000 mg/l total dissolved solids boundary feature

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  7. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Clipping boundary extent for the first permeable zone below the LISAPCU

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  8. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Points for the top of the Lower Floridan aquifer below the LISAPCU

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  9. Effect of growth mechanisms on the deformation of a unit cell and polarization reversal in barium-strontium titanate heterostructures on magnesium oxide

    Science.gov (United States)

    Mukhortov, V. M.; Golovko, Yu. I.; Biryukov, S. V.; Anokhin, A.; Yuzyuk, Yu. I.

    2016-01-01

    The effect of a growth mechanism on the unit cell strain and the related change in the properties of single-crystal Ba0.8Sr0.2TiO3 films grown on MgO substrates according to the Frank-van der Merwe and Volmer-Weber growth mechanisms is studied. The unit cell strain is shown to depend substantially on the film thickness and the growth mechanism. It is found that the same film-substrate pair can be used to vary stresses in the film from two-dimensional tensile to compressive stresses due to a change in the growth mechanism and the film thickness.

  10. Decreased retinal ganglion cell layer thickness in patients with type 1 diabetes

    NARCIS (Netherlands)

    Dijk, Hille W. van; Verbraak, Frank D.; Kok, Pauline H. B.; Garvin, Mona K.; Sonka, Milan; Lee, Kyungmoo; DeVries, J. Hans; Michels, Robert P. J.; Velthoven, Mirjam E. J. van; Schlingemann, Reinier O.; Abramoff, M.D.

    2010-01-01

    Purpose. To determine which retinal layers are most affected by diabetes and contribute to thinning of the inner retina and to investigate the relationship between retinal layer thickness (LT) and diabetes duration, diabetic retinopathy (DR) status, age, glycosylated hemoglobin (HbA1c), and the sex

  11. Performance Enhancement of Dye-Sensitized Solar Cells Based on TiO₂ Thick Mesoporous Photoanodes by Morphological Manipulation.

    Science.gov (United States)

    Keshavarzi, Reza; Mirkhani, Valiollah; Moghadam, Majid; Tangestaninejad, Shahram; Mohammadpoor-Baltork, Iraj

    2015-10-27

    This study is an attempt to give an account of the preparation of mesoporous TiO2 thick templated films of nonsimilar pore architecture and their use in dye-sensitized solar cells (DSSCs). Highly crystallized mesoporous titania thick templated films with four different morphologies including hexagonal, wormlike, cubic, and gridlike mesostructure, have been successfully synthesized through an evaporation-induced self-assembly (EISA) route followed by layer-by-layer deposition. Stabilization, followed by each coating, and calcinations, carried out after every five layers, were used to produce crack-free thick films. These mesoporous templated titanium dioxide samples were characterized by TEM, XRD, SEM, BET, and UV-vis measurements and used as a photoelectrode material in DSSCs. The mesostructured films with a thickness of about 7 μm demonstrated better performance in comparison to nanocrystalline TiO2 films (NC-TiO2) at a film thickness of 13 μm as the most typical films utilized in DSSCs. The findings reveal that a surfactant/Ti ratio change undergone for developing cubic mesostructures can enhance the crystallinity and roughness factor and therefore increase the energy conversion efficiency of DSSC. The cell performances derived from these mesofilms were enhanced compared to the efficiencies reported thus far. The best photovoltaic performance of 8.73% came from DSSC using the cubic mesoporous TiO2 photoelectrode with the following properties: open circuit voltage of 743 mV, short circuit photocurrent density of 16.35 mA/cm(2), and fill factor of 0.72.

  12. MoO3 Thickness, Thermal Annealing and Solvent Annealing Effects on Inverted and Direct Polymer Photovoltaic Solar Cells

    Directory of Open Access Journals (Sweden)

    Guillaume Wantz

    2012-11-01

    Full Text Available Several parameters of the fabrication process of inverted polymer bulk heterojunction solar cells based on titanium oxide as an electron selective layer and molybdenum oxide as a hole selective layer were tested in order to achieve efficient organic photovoltaic solar cells. Thermal annealing treatment is a common process to achieve optimum morphology, but it proved to be damageable for the performance of this kind of inverted solar cells. We demonstrate using Auger analysis combined with argon etching that diffusion of species occurs from the MoO3/Ag top layers into the active layer upon thermal annealing. In order to achieve efficient devices, the morphology of the bulk heterojunction was then manipulated using the solvent annealing technique as an alternative to thermal annealing. The influence of the MoO3 thickness was studied on inverted, as well as direct, structure. It appeared that only 1 nm-thick MoO3 is enough to exhibit highly efficient devices (PCE = 3.8% and that increasing the thickness up to 15 nm does not change the device performance. 

  13. Optoelectric Properties of GaInP p-i-n Solar Cells with Different i-Layer Thicknesses

    Directory of Open Access Journals (Sweden)

    Tsung-Shine Ko

    2015-01-01

    Full Text Available The optoelectric properties of GaInP p-i-n solar cells with different intrinsic layer (i-layer thicknesses from 0.25 to 1 μm were studied. Both emission intensity and full width at half maximum features of the photoluminescence spectrum indicate that the optimum i-layer thickness would be between 0.5 and 0.75 μm. The integrated current results of photocurrent experiment also point out that the samples with 0.5 to 0.75 μm i-layer thicknesses have optimum value around 156 nA. Electroreflectance measurements reveal that the built-in electric field strength of the sample gradually deviates from the theoretical value larger when i-layer thickness of the sample is thicker than 0.75 μm. I-V measurements also confirm crystal quality for whole samples by obtaining the information about short currents of photovoltaic performances. A series of experiments reflect that thicker i-layer structure would induce more defects generation lowering crystal quality.

  14. Effect of compressed TiO2 nanoparticle thin film thickness on the performance of dye-sensitized solar cells.

    Science.gov (United States)

    Tsai, Jenn Kai; Hsu, Wen Dung; Wu, Tian Chiuan; Meen, Teen Hang; Chong, Wen Jie

    2013-11-05

    In this study, dye-sensitized solar cells (DSSCs) were fabricated using nanocrystalline titanium dioxide (TiO2) nanoparticles as photoanode. Photoanode thin films were prepared by doctor blading method with 420 kg/cm2 of mechanical compression process and heat treatment in the air at 500°C for 30 min. The optimal thickness of the TiO2 NP photoanode is 26.6 μm with an efficiency of 9.01% under AM 1.5G illumination at 100 mW/cm2. The efficiency is around two times higher than that of conventional DSSCs with an uncompressed photoanode. The open-circuit voltage of DSSCs decreases as the thickness increases. One DSSC (sample D) has the highest conversion efficiency while it has the maximum short-circuit current density. The results indicate that the short-circuit current density is a compromise between two conflict factors: enlargement of the surface area by increasing photoanode thickness and extension of the electron diffusion length to the electrode as the thickness increases.

  15. Retinal vessel diameters decrease with macular ganglion cell layer thickness in autosomal dominant optic atrophy and in healthy subjects

    DEFF Research Database (Denmark)

    Rönnbäck, Cecilia; Grønskov, Karen; Larsen, Michael

    2014-01-01

    PURPOSE: To investigate retinal trunk vessel diameters in subjects with autosomal dominant optic atrophy (ADOA) and mutation-free healthy relatives. METHODS: This cross-sectional study included 52 ADOA patients with the optic atrophy 1 (OPA1) exon 28 (c.2826_2836delinsGGATGCTCCA) mutation (age 8...... ganglion cell-inner plexiform layer (GC-IPL) thickness (p = 0.0017 and p = 0.0057, respectively). CONCLUSION: Narrow retinal arteries and veins were associated not only with the severity of ADOA but with ganglion cell volume in patients with ADOA and in healthy subjects. This suggests that narrow vessels...

  16. Effect of well layer thickness on quantum and energy conversion efficiencies for InGaN/GaN multiple quantum well solar cells

    Science.gov (United States)

    Miyoshi, Makoto; Tsutsumi, Tatsuya; Kabata, Tomoki; Mori, Takuma; Egawa, Takashi

    2017-03-01

    We investigated the effect of well layer thicknesses on the external quantum efficiency (EQE) and energy conversion efficiency (ECE) for InGaN/GaN multiple quantum well (MQW) solar cells grown on sapphire substrates by metalorganic chemical vapor deposition. The results indicated that EQE and ECE have maximum values at a specific well thickness. When the well thickness is sufficiently thin, EQE and ECE increase with an increase in the well thickness owing to an increase in light absorption. Then, once the well thickness surpasses a critical thickness, EQE and ECE begin to decrease owing to the influence of nonradiative recombination processes, which was indicated by the static and dynamic photoluminescence analyses. The critical well thickness probably depends not only on the MQW design but also on growth conditions. Further, we confirmed that the increased total thickness of the stacked well layers leads to increased light absorption and thereby contributes to the improvement of solar cell performance. A high short circuit current density of 1.34 mA/cm2 and a high ECE of 1.31% were achieved for a InGaN/GaN MQW solar cell with a 3.2-nm-thick InGaN well with total well thickness of 115 nm.

  17. Tuning the Thickness of Ba-Containing "Functional" Layer toward High-Performance Ceria-Based Solid Oxide Fuel Cells.

    Science.gov (United States)

    Gong, Zheng; Sun, Wenping; Shan, Duo; Wu, Yusen; Liu, Wei

    2016-05-04

    Developing highly efficient ceria-based solid oxide fuel cells with high power density is still a big concern for commercial applications. In this work, a novel structured Ce0.8Sm0.2O2-δ (SDC)-based fuel cell with a bilayered anode consisting of Ni-SDC and Ni-BaZr0.1Ce0.7Y0.2O3-δ (Ni-BZCY) was designed. In addition to the catalysis function, the Ni-BZCY anode "functional" layer also provides Ba source for generating an electron-blocking layer in situ at the anode/electrolyte interface during sintering. The Ni-BZCY thickness significantly influences the quality of the electron-blocking layer and electrochemical performances of the cell. The cell with a 50 μm thick Ni-BZCY layer exhibits the best performance in terms of open circuit voltage (OCV) and peak power density (1068 mW cm(-2) at 650 °C). The results demonstrate that this cell with an optimal structure has a distinct advantage of delivering high power performance with a high efficiency at reduced temperatures.

  18. Analysis of the interdigitated back contact solar cells: The n-type substrate lifetime and wafer thickness

    Science.gov (United States)

    Zhang, Wei; Chen, Chen; Jia, Rui; Sun, Yun; Xing, Zhao; Jin, Zhi; Liu, Xin-Yu; Liu, Xiao-Wen

    2015-10-01

    The n-type silicon integrated-back contact (IBC) solar cell has attracted much attention due to its high efficiency, whereas its performance is very sensitive to the wafer of low quality or the contamination during high temperature fabrication processing, which leads to low bulk lifetime τbulk. In order to clarify the influence of bulk lifetime on cell characteristics, two-dimensional (2D) TCAD simulation, combined with our experimental data, is used to simulate the cell performances, with the wafer thickness scaled down under various τbulk conditions. The modeling results show that for the IBC solar cell with high τbulk, (such as 1 ms-2 ms), its open-circuit voltage Voc almost remains unchanged, and the short-circuit current density Jsc monotonically decreases as the wafer thickness scales down. In comparison, for the solar cell with low τbulk (for instance, Solar Energy Action Plan from the Chinese Academy of Sciences (Grant Nos. Y3ZR044001 and Y2YF014001).

  19. Learning about the Unit Cell and Crystal Lattice with Computerized Simulations and Games: A Pilot Study

    Science.gov (United States)

    Luealamai, Sutha; Panijpan, Bhinyo

    2012-01-01

    The authors have developed a computer-based learning module on the unit cell of various types of crystal. The module has two components: the virtual unit cell (VUC) part and the subsequent unit cell hunter part. The VUC is a virtual reality simulation for students to actively arrive at the unit cell from exploring, from a broad view, the crystal…

  20. Learning about the Unit Cell and Crystal Lattice with Computerized Simulations and Games: A Pilot Study

    Science.gov (United States)

    Luealamai, Sutha; Panijpan, Bhinyo

    2012-01-01

    The authors have developed a computer-based learning module on the unit cell of various types of crystal. The module has two components: the virtual unit cell (VUC) part and the subsequent unit cell hunter part. The VUC is a virtual reality simulation for students to actively arrive at the unit cell from exploring, from a broad view, the crystal…

  1. Magnetron sputtered zinc oxide nanorods as thickness-insensitive cathode interlayer for perovskite planar-heterojunction solar cells.

    Science.gov (United States)

    Liang, Lusheng; Huang, Zhifeng; Cai, Longhua; Chen, Weizhong; Wang, Baozeng; Chen, Kaiwu; Bai, Hua; Tian, Qingyong; Fan, Bin

    2014-12-10

    Suitable electrode interfacial layers are essential to the high performance of perovskite planar heterojunction solar cells. In this letter, we report magnetron sputtered zinc oxide (ZnO) film as the cathode interlayer for methylammonium lead iodide (CH3NH3PbI3) perovskite solar cell. Scanning electron microscopy and X-ray diffraction analysis demonstrate that the sputtered ZnO films consist of c-axis aligned nanorods. The solar cells based on this ZnO cathode interlayer showed high short circuit current and power conversion efficiency. Besides, the performance of the device is insensitive to the thickness of ZnO cathode interlayer. Considering the high reliability and maturity of sputtering technique both in lab and industry, we believe that the sputtered ZnO films are promising cathode interlayers for perovskite solar cells, especially in large-scale production.

  2. Efficient long-term survival of cell grafts after myocardial infarction with thick viable cardiac tissue entirely from pluripotent stem cells.

    Science.gov (United States)

    Matsuo, Takehiko; Masumoto, Hidetoshi; Tajima, Shuhei; Ikuno, Takeshi; Katayama, Shiori; Minakata, Kenji; Ikeda, Tadashi; Yamamizu, Kohei; Tabata, Yasuhiko; Sakata, Ryuzo; Yamashita, Jun K

    2015-11-20

    Poor engraftment of cells after transplantation to the heart is a common and unresolved problem in the cardiac cell therapies. We previously generated cardiovascular cell sheets entirely from pluripotent stem cells with cardiomyocytes, endothelial cells and vascular mural cells. Though sheet transplantation showed a better engraftment and improved cardiac function after myocardial infarction, stacking limitation (up to 3 sheets) by hypoxia hampered larger structure formation and long-term survival of the grafts. Here we report an efficient method to overcome the stacking limitation. Insertion of gelatin hydrogel microspheres (GHMs) between each cardiovascular cell sheet broke the viable limitation via appropriate spacing and fluid impregnation with GHMs. Fifteen sheets with GHMs (15-GHM construct; >1 mm thickness) were stacked within several hours and viable after 1 week in vitro. Transplantation of 5-GHM constructs (≈2 × 10(6) of total cells) to a rat myocardial infarction model showed rapid and sustained functional improvements. The grafts were efficiently engrafted as multiple layered cardiovascular cells accompanied by functional capillary networks. Large engrafted cardiac tissues (0.8 mm thickness with 40 cell layers) successfully survived 3 months after TX. We developed an efficient method to generate thicker viable tissue structures and achieve long-term survival of the cell graft to the heart.

  3. Biology 23. Unit One -- The Cell: Structure and Physiology.

    Science.gov (United States)

    Nederland Independent School District, TX.

    GRADES OR AGES: Not given. SUBJECT MATTER: Biology, the structure and physiology of the cell. ORGANIZATION AND PHYSICAL APPEARANCE: There are four sections: a) objectives for the unit, b) bibliography, c) activities, and d) evaluation. The guide is directed to the student rather than the teacher. The guide is mimeographed and stapled, with no…

  4. Recombinant human collagen III gel for transplantation of autologous skin cells in porcine full-thickness wounds.

    Science.gov (United States)

    Nuutila, Kristo; Peura, Matti; Suomela, Sari; Hukkanen, Mika; Siltanen, Antti; Harjula, Ari; Vuola, Jyrki; Kankuri, Esko

    2015-12-01

    Complex skin wounds, such as chronic ulcers and deep burns, require lengthy treatments and cause extensive burdens on healthcare and the economy. Use of biomaterials and cell transplantation may improve traditional treatments and promote the healing of difficult-to-treat wounds. In this study, we investigated the use of recombinant human collagen III (rhCol-III) gel as a delivery vehicle for cultured autologous skin cells (keratinocytes only or keratinocyte-fibroblast mixtures). We examined its effect on the healing of full-thickness wounds in a porcine wound-healing model. Two Landrace pigs were used for the study. Fourteen deep dermal wounds were created on the back of each pig with an 8 mm biopsy punch. Syringes containing acellular rhCol-III gel (n = 8) or rhCol-III gel with autologous keratinocytes (n = 8) or rhCol-III gel with autologous keratinocytes and fibroblasts (n = 8) were applied into wounds. Untreated wounds were used as controls for the treatment groups (n = 4). We used rhCol-III gel to manufacture a cell-delivery syringe containing autologous skin cells. In a full-thickness wound-healing model, we observed that rhCol-III gel enhances early granulation tissue formation. Interestingly, we found cell type-dependent differences in the stability of rhCol-III in vivo. Fibroblast-containing gel was effectively removed from the wound, whereas gels without cells or with keratinocytes only remained intact. Our results demonstrate that the properties of rhCol-III gel for skin cell transplantation can be significantly altered in a cell type-dependent manner.

  5. Organochlorine residues and shell thickness in eggs of the clapper rail, common gallinule, purple gallinule, and limpkin (Class Aves), eastern and southern United States, 1972-74

    Science.gov (United States)

    Klaas, E.E.; Ohlendorf, H.M.; Cromartie, E.

    1980-01-01

    Organochlorine residues and shell thicknesses were surveyed in eggs of the clapper rail (Rallus longirostris), purple gallinule (Porphyrula martinica), common gallinule (Gallinula chloropas), and limpkin (Aramus guarauna) from the eastern and southern United States. Clapper rail eggs were collected during 1972-73 in New Jersey, Virginia, and South Carolina. During 1973-74, gallinule eggs were collected in Florida, South Carolina, and Louisiana, and limpkin eggs were collected in Florida. Egg contents were analyzed for residues of organochlorine pesticides, including DDT, TDE, DDE, dieldrin, mirex, heptachlor epoxide, oxychlordane, cis-chlordane (and/or trans-nonachlor), cis-nonachlor, hexachlorobenzene (HCB), toxaphene, and endrin, and for polychlorinated biphenyls (PCBs). Shell thicknesses of recent eggs of these species were compared with archival eggs that had been collected before 1947. With the exception of the limpkin, the majority of eggs analyzed contained residues of p,p'-DDE and PCBs. Geometric means ranged from 0.10 ppm to 1.3 ppm. Small amounts (less than 1.0 ppm) of mirex, dieldrin, cis-chlordane (and/or trans-nonachlor), TDE, and DDT were detected in a few eggs. No evidence of eggshell thinning was found for any of the species studied. DDE residues in clapper rail eggs were higher in New Jersey and Virginia than in South Carolina.

  6. Reduced Cu(InGa)Se2 Thickness in Solar Cells Using a Superstrate Configuration

    Energy Technology Data Exchange (ETDEWEB)

    Shafarman, William N. [Univ. of Delaware, Newark, DE (United States)

    2015-03-30

    This project by the Institute of Energy Conversion (IEC) and the Department of Electrical and Computer Engineering at the University of Delaware sought to develop the technology and underlying science to enable reduced cost of Cu(InGa)Se2 manufacturing by reducing the thickness of the Cu(InGa)Se2 absorber layer by half compared to typical production. The approach to achieve this was to use the superstrate cell configuration in which light is incident on the cell through the glass. This structure facilitates optical enhancement approaches needed to achieve high efficiency with Cu(InGa)Se2 thicknesses less than 1 µm. The primary objective was to demonstrate a Cu(InGa)Se2 cell with absorber thickness 0.5 - 0.7 µm and 17% efficiency, along with a quantitative loss analysis to define a pathway to 20% efficiency. Additional objectives were the development of stable TCO and buffer layers or contact layers to withstand the Cu(InGa)Se2 deposition temperature and of advanced optical enhancement methods. The underlying fundamental science needed to effectively transition these outcomes to large scale was addressed by extensive materials and device characterization and by development of comprehensive optical models. Two different superstrate configurations have been investigated. A frontwall cell is illuminated through the glass to the primary front junction of the device. This configuration has been used for previous efforts on superstrate Cu(InGa)Se2 but performance has been limited by interdiffusion or reaction with CdS or other buffer layers. In this project, several approaches to overcome these limitations were explored using CdS, ZnO and ZnSe buffer layers. In each case, mechanisms that limit device performance were identified using detailed characterization of the materials and junctions. Due to the junction formation difficulties, efforts were concentrated on a new backwall configuration in which light

  7. Polymer electrolyte fuel cell mini power unit for portable application

    Science.gov (United States)

    Urbani, F.; Squadrito, G.; Barbera, O.; Giacoppo, G.; Passalacqua, E.; Zerbinati, O.

    This paper describes the design, realisation and test of a power unit based on a polymer electrolyte fuel cell, operating at room temperature, for portable application. The device is composed of an home made air breathing fuel cell stack, a metal hydride tank for H 2 supply, a dc-dc converter for power output control and a fan for stack cooling. The stack is composed by 10 cells with an active surface of 25 cm 2 and produces a rated power of 15 W at 6 V and 2 A. The stack successfully runs with end-off fed hydrogen without appreciable performance degradation during the time. The final assembled system is able to generate 12 W at 9.5 V, and power a portable DVD player for 3 h in continuous. The power unit has collected about 100 h of operation without maintenance.

  8. Polymer electrolyte fuel cell mini power unit for portable application

    Energy Technology Data Exchange (ETDEWEB)

    Urbani, F.; Squadrito, G.; Barbera, O.; Giacoppo, G.; Passalacqua, E. [CNR-ITAE, via Salita S. Lucia sopra Contesse n. 5, 98126 S. Lucia, Messina (Italy); Zerbinati, O. [Universita del Piemonte Orientale, Dip. di Scienze dell' Ambiente e della Vita, via Bellini 25/g, 15100 Alessandria (Italy)

    2007-06-20

    This paper describes the design, realisation and test of a power unit based on a polymer electrolyte fuel cell, operating at room temperature, for portable application. The device is composed of an home made air breathing fuel cell stack, a metal hydride tank for H{sub 2} supply, a dc-dc converter for power output control and a fan for stack cooling. The stack is composed by 10 cells with an active surface of 25 cm{sup 2} and produces a rated power of 15 W at 6 V and 2 A. The stack successfully runs with end-off fed hydrogen without appreciable performance degradation during the time. The final assembled system is able to generate 12 W at 9.5 V, and power a portable DVD player for 3 h in continuous. The power unit has collected about 100 h of operation without maintenance. (author)

  9. PITUITARY ADENOMA- VISUAL FIELDS, RETINAL NERVE FIBRE LAYER AND GANGLION CELL-INNER PLEXIFORM LAYER THICKNESS ANALYSIS- A CORRELATIONAL STUDY

    Directory of Open Access Journals (Sweden)

    Jyoti Shetty

    2017-07-01

    Full Text Available BACKGROUND Pituitary adenoma is a benign and most common tumour of the pituitary gland. It is also the most common parachiasmal tumour and accounts for approximately 10-15% of primary intracranial neoplasms. It has an annual incidence rate of 0.8–8 per 1,00,000 population. Pituitary adenomas are classified as functional and non-functional based on their hormonal activity. Functional adenomas are usually detected earlier due to clinical manifestations produced by excess of hormones. The aim of the study is to analyse visual acuity, visual fields, RNFL thickness and GCIPL thickness on optical coherence tomography (OCT and to find a correlation between these parameters and tumour volume in patients diagnosed with pituitary adenoma. MATERIALS AND METHODS 48 patients diagnosed with pituitary adenoma confirmed by MRI scan underwent complete ophthalmic evaluation (visual acuity, slit-lamp examination, fundus evaluation, perimetry using 30-2 SITA FAST strategy, (Humphrey Field Analyzer; Carl-Zeiss Meditec, Dublin, CA, and OCT of disc (for retinal nerve fibre layer- RNFL thickness and macula (for ganglion cell-inner plexiform layer (GCIPL thickness using Cirrus HD-OCT (Carl Zeiss Meditec, Dublin, CA at Bangalore West Lions Super Speciality Eye Hospital, between June 2014 to June 2016. Various parameters like Mean Deviation (MD, Pattern Standard Deviation (PSD and RNFL and GCIPL thickness on OCT were analysed and correlated with each other. RESULTS Mean tumour volume in patients was 12.26 ± 15.8 cm3 . Most of the patients had visual acuity 6/18 or better. Bitemporal hemianopia was seen in only 5 (12.2% patients. Superotemporal quadrantanopia, arcuate defects, tubular fields and homonymous hemianopia were the other field defects seen. Total and pattern deviation plot of visual fields correlated well with tumour volume and visual acuity. On visual field analysis, the MD (-8.18 ± 8.65 dB was depressed compared to the control group (-2.0 ± 1.8 dB, and

  10. The application of human umbilical cord blood mononuclear cells in the management of deep partial thickness burn

    Directory of Open Access Journals (Sweden)

    Yefta Moenadjat

    2013-05-01

    Full Text Available Background: Wound healing in burn is a complex process and early complete wound closure still enfaces many problems. Application of stem cells is found to be the future method of wound healing. Among the available sources of allogenic stem cells, umbilical cord blood is quite easy to be obtained, has less ethical issue, and contain multipotent stem cells, which are characterized by low immunogenicity. The study aims to evaluate the potential of human umbilical cord blood mononuclear cells (hUCBMNCs treatment in the management of deep partial thickness burns. Methods: Twenty patients with deep partial thickness burns were treated with topical application of 2 x 107 hUCBMNCs and silver sulfadiazine (SSD cream on the comparable wound size in the other sites. The treatments were applied for six times in every two consecutive days. Wound surface area was measured with Visitrak® on day 0, 7, and 11. Pain intensity was evaluated using Wong Baker’s faces scale on each wound dressing change. Histology examination was performed in some samples of collected skin biopsy of the newly re-epithelialized area of hUCBMNCs and SSD-treated wound at the end of treatment. HLA typing is used to evaluate the issue of safety. Wilcoxon signed rank test was used to compare the rate of wound healing. Results: Sixteen patients of hUCBMNCs-treated showed a significant wound closure in faster than SSD-treated; measured on day 7 (p = 0.041 and day 11 (p = 0.021. Number of patients with reduced pain intensity, from approximately scale 3 to 1/0 on day 7 and 11, were higher in hUCBMNCs-treated compared to SSD-treated wound. In spite of the HLA-mismatch, no allergic reaction, rejection, and infection found on hUCBMNCs-treated wound suggested the safety of this therapy. Histology examination found the formation of dermal-epidermal junction and rete ridges equal to the normal skin on hUCBMNCs-treated wounds. Conclusion: hUCBMNCs are effective and safe to promote re

  11. Full-thickness tissue engineered skin constructed with autogenic bone marrow mesenchymal stem cells

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    To explore the feasibility of repairing clinical cutaneous deficiency, autogenic bone marrow mesen-chymal stem cells (BMSCs) were isolated and differentiated into epidermal cells and fibroblasts in vitro supplemented with different inducing factors and biomaterials to construct functional tissue- engineered skin. The results showed that after 72 h induction, BMSCs displayed morphologic changes such as typical epidermal cell arrangement, from spindle shape to round or oval; tonofibrils, melano-somes and keratohyaline granules were observed under a transmission electronic microscope. The differentiated cells expressed epidermal stem cell surface marker CK19 (59.66% ± 4.2%) and epidermal cells differentiation marker CK10. In addition, the induced epidermal cells acquired the anti-radiation capacity featured by lowered apoptosis following exposure to UVB. On the other hand, the collagen microfibrils deposition was noticed under a transmission electronic microscope after differentiating into dermis fibroblasts; RT-PCR identified collagen type I mRNA expression in differentiated cells; radioimmunoassay detected the secretion of interleukin-6 (IL-6) and interleukin-8 (IL-8) (up to 115.06 pg/mL and 0.84 ng/mL, respectively). Further in vivo implanting BMSCs with scaffold material short-ened skin wound repair significantly. In one word, autogenic BMSCs have the potential to differentiate into epidermal cells and fibroblasts in vitro, and show clinical feasibility acting as epidermis-like and dermis-like seed cells in skin engineering.

  12. Full-thickness tissue engineered skin constructed with autogenic bone marrow mesenchymal stem cells

    Institute of Scientific and Technical Information of China (English)

    HE LiJuan; PEI XueTao; NAN Xue; WANG YunFang; GUAN LiDong; BAI CiXian; SHI ShuangShuang; YUAN HongFeng; CHEN Lin; LIU DaQing

    2007-01-01

    To explore the feasibility of repairing clinical cutaneous deficiency, autogenic bone marrow mesenchymal stem cells (BMSCs) were isolated and differentiated into epidermal cells and fibroblasts in vitro supplemented with different inducing factors and biomaterials to construct functional tissueengineered skin. The results showed that after 72 h induction, BMSCs displayed morphologic changes such as typical epidermal cell arrangement, from spindle shape to round or oval; tonofibrils, melanosomes and keratohyaline granules were observed under a transmission electronic microscope. The differentiated cells expressed epidermal stem cell surface marker CK19 (59.66%±4.2%) and epidermal cells differentiation marker CK10. In addition, the induced epidermal cells acquired the anti-radiation capacity featured by lowered apoptosis following exposure to UVB. On the other hand, the collagen microfibrils deposition was noticed under a transmission electronic microscope after differentiating into dermis fibroblasts; RT-PCR identified collagen type Ⅰ mRNA expression in differentiated cells;radioimmunoassay detected the secretion of interleukin-6 (IL-6) and interleukin-8 (IL-8) (up to 115.06pg/mL and 0.84 ng/mL, respectively). Further in vivo implanting BMSCs with scaffold material shortened skin wound repair significantly. In one word, autogenic BMSCs have the potential to differentiate into epidermal cells and fibroblasts in vitro, and show clinical feasibility acting as epidermis-like and dermis-like seed cells in skin engineering.

  13. Microbial fuel cells as pollutant treatment units: Research updates.

    Science.gov (United States)

    Zhang, Quanguo; Hu, Jianjun; Lee, Duu-Jong

    2016-10-01

    Microbial fuel cells (MFC) are a device that can convert chemical energy in influent substances to electricity via biological pathways. Based on the consent that MFC technology should be applied as a waste/wastewater treatment unit rather than a renewable energy source, this mini-review discussed recent R&D efforts on MFC technologies for pollutant treatments and highlighted the challenges and research and development needs. Owing to the low power density levels achievable by larger-scale MFC, the MFC should be used as a device other than energy source such as being a pollutant treatment unit.

  14. Influence of nanostructured TiO2 film thickness on photoelectrode structure and performance of flexible Dye- Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    M. Malekshahi Byranvand

    2012-09-01

    Full Text Available A  commercial  Ti-Nanoxide  was  deposited  on  In-doped  SnO2 (ITO polymer  substrates by  tape casting  technique with different thicknesses  (7,  14  and  36μm  to  be  used  as  photoelectrode  in flexible  dye-sensitized  solar  cells  (DSSCs.  Ruthenium  dye  was adsorbed on each TiO2 film for 24 h. The resulting photoelectrodes were used to form flexible DSSCs in combination with electrolyte and  counter  electrode.  The  prepared  films  were  characterized  by scanning electron microscopy (SEM and atomic force microscopy (AFM.    Photovoltaic  parameters  like  short  circuit  current  (Isc, open  circuit  voltage  (Voc,  fill  factor  (FF  and power  conversion efficiency (η were evaluated for fabricated cells. The cell formed with a TiO2 film of 14μm thickness reached the best performance. 2012 JNS All rights reserved

  15. Optimum Thickness Conditions of TiO2 Nanotubes Layer for Efficient Electrochemical Luminescence Cells Application.

    Science.gov (United States)

    Choi, Min-Ki; Sung, Youl-Moon; Park, Min-Woo

    2015-02-01

    We report a TiO2 nanotubes (NTs)-based Electrochemical luminescence (ECL) cell. The ECL cell was fabricated using the electrode of TiO2 NTs and Ru(II) complex (Ru(bpy)2+(3)) as a luminescence materials. The fabricated ECL cell is composed of F-doped SnO2 (FTO) glass/Ru(II)/TiO2 NTs/Ti plate. At a bias voltage of 3 V, the measured ECL efficiencies were 0 Im/W for cell without NTs, 0.03 Im/W for NTs-6.5 µm, 0.07 Im/W for NTs-8 µm and 0.1 Im/W for NTs-10 µm, respectively. The use of Ti02 NTs increases ECL intensities by about 2 times compared to the typical ECL cell without the use of TiO2 NTs.

  16. Optimization of Band Gap and Thickness for the Development of Efficient n-i-p+ Solar Cell

    Directory of Open Access Journals (Sweden)

    A. Belfar

    2015-06-01

    Full Text Available By using an electrical-optical AMPS-1D program (One Dimensional Analysis of Microelectronic and Photonic structures, a n-i-p type solar cell, based on hydrogenated amorphous silicon (a-Si : H and hydrogenated nanocrystalline silicon oxide (nc-SiOx : H has been investigated and simulated. The numerical analysis describes the modeling of the external cell performances, like, the short-circuit current (JSC, the open circuit voltage (VOC, the fill factor (FF and efficiency (Eff with the oxygen content in the p-nc-SiOx : H window layer by varying its mobility band gap (Eg associated simultaneously to the effect of the absorber layer (i-a-Si : H thickness. Also, the i-a-Si : H absorber layer band gap was optimized. The simulation result shows that the VOC depend strongly on the band offset (ΔEV in valence band of p-side. But, VOC does not depend on the thickness of the intrinsic layer. However, VOC increases when the energy band gap of the intrinsic layer is higher. It is demonstrated that the highest efficiency of 10.44 % (JSC = 11.67 mA/cm2; FF = 0.829; VOC = 1070 mV has been obtained when values of p-nc-SiOx : H window layer band gap, i-a-Si : H absorber layer band gap and i-a-Si : H absorber layer thickness are 2.10 eV, 1.86 eV, and 550 nm, respectively.

  17. Zero loss magnetic metamaterials using powered active unit cells.

    Science.gov (United States)

    Yuan, Yu; Popa, Bogdan-Ioan; Cummer, Steven A

    2009-08-31

    We report the design and experimental measurement of a powered active magnetic metamaterial with tunable permeability. The unit cell is based on the combination of an embedded radiofrequency amplifier and a tunable phase shifter, which together control the response of the medium. The measurements show that a negative permeability metamaterial with zero loss or even gain can be achieved through an array of such metamaterial cells. This kind of active metamaterial can find use in applications that are performance limited due to material losses.

  18. A heated vapor cell unit for DAVLL in atomic rubidium

    OpenAIRE

    McCarron, Daniel J.; Hughes, Ifan G.; Tierney, Patrick; Cornish, Simon L

    2007-01-01

    The design and performance of a compact heated vapor cell unit for realizing a dichroic atomic vapor laser lock (DAVLL) for the D2 transitions in atomic rubidium is described. A 5 cm-long vapor cell is placed in a double-solenoid arrangement to produce the required magnetic field; the heat from the solenoid is used to increase the vapor pressure and correspondingly the DAVLL signal. We have characterized experimentally the dependence of important features of the DAVLL signal on magnetic field...

  19. Composite Bipolar Plate for Unitized Fuel Cell/Electrolyzer Systems

    Science.gov (United States)

    Mittelsteadt, Cortney K.; Braff, William

    2009-01-01

    In a substantial improvement over present alkaline systems, an advanced hybrid bipolar plate for a unitized fuel cell/electrolyzer has been developed. This design, which operates on pure feed streams (H2/O2 and water, respectively) consists of a porous metallic foil filled with a polymer that has very high water transport properties. Combined with a second metallic plate, the pore-filled metallic plates form a bipolar plate with an empty cavity in the center.

  20. Solid Oxide Fuel Cells coupled with a biomass gasification unit

    Directory of Open Access Journals (Sweden)

    Skrzypkiewicz Marek

    2016-01-01

    Full Text Available A possibility of fuelling a solid oxide fuel cell stack (SOFC with biomass fuels can be realized by coupling a SOFC system with a self-standing gasification unit. Such a solution enables multi-fuel operation, elasticity of the system as well as the increase of the efficiency of small-scale biomass-to-electricity conversion units. A system of this type, consisting of biomass gasification unit, gas purification unit, SOFC stack, anode off-gas afterburner and peripherals was constructed and operated successfully. During the process, biomass fuel (wood chips was gasified with air as gasification agent. The gasifier was capable of converting up to 30 kW of fuel to syngas with efficiencies up to 75%. Syngas leaving the gasification unit is delivered to a medium temperature adsorber for sulphur compounds removal. Steam is added to the purified fuel to maintain steam to carbon ratio higher than 2. The syngas then is passed to a SOFC stack through a fuel preheater. In such a configuration it was possible to operate a commercial 1.3 kW stack within its working regime. Conducted tests confirmed successful operation of a SOFC stack fuelled by biomass-sourced syngas.

  1. CCL5 and CCL20 mediate immigration of Langerhans cells into the epidermis of full thickness human skin equivalents.

    Science.gov (United States)

    Ouwehand, Krista; Spiekstra, Sander W; Waaijman, Taco; Breetveld, Melanie; Scheper, Rik J; de Gruijl, Tanja D; Gibbs, Susan

    2012-10-01

    Epidermal Langerhans cells (LC) play a key role in initiation and regulation of immune responses. Whereas LC migration out of the epidermis upon environmental assault is extensively studied, the mechanisms involved in the (re)population of the epidermis with LC are poorly understood. Here, we investigated the immigration of LC derived from the human MUTZ-3 cell line (MUTZ-LC) into the epidermis of a full thickness skin equivalent, comprising a fully differentiated epidermis on a fibroblast-populated dermis. MUTZ-LC were used to determine which epidermis-derived chemokines play a role in mediating LC trans-dermal migration into the epidermis. We found evidence for a role of keratinocyte-derived CCL5 and CCL20 in the chemo-attraction of MUTZ-LC. Neutralizing antibodies against CCL5 and CCL20 blocked LC migration towards keratinocytes. Secretion of these two chemokines was associated with incorporation of MUTZ-LC into the epidermis of full thickness skin equivalents. In conclusion, our findings suggest that epidermis derived CCL5 and CCL20 are pivotal mediators in recruitment of LC into the epidermis.

  2. Microprocessor-based data acquisition system incorporating a floating-point arithmetic unit for complex mathematical computations. [To determine thickness of conductors on printed wiring boards from measured resistance by use of curve-fitting equations

    Energy Technology Data Exchange (ETDEWEB)

    Hopwood, J.

    1978-02-01

    A microprocessor-based, stored-program controller which incorporates a floating-point arithmetic unit to perform complex mathematical computations was developed to determine the thickness of conductors on printed wiring boards. Conductor thickness is calculated from measured resistance by means of curve-fitting equations in the stored program. Called a film thickness calculator, the instrument demonstrates a method which may serve as a basis for other designs involving microprocessor-based data acquisition systems requiring low-speed calculations. 19 figures.

  3. Thermodynamics of Condensed Phases: Formula Unit Volume, "V[subscript m]", and the Determination of the Number of Formula Units, "Z", in a Crystallographic Unit Cell

    Science.gov (United States)

    Glasser, Leslie

    2011-01-01

    Formula unit (or molecular) volume, "V[subscript m]", is related to many thermodynamic and physical properties of materials, so that knowledge of "V[subscript m]" is useful in prediction of such properties for known and even hypothetical materials. The symbol "Z" represents the number of formula units in a crystallographic unit cell; "Z" thus…

  4. Fluid dilution and efficiency of Na(+) transport in a mathematical model of a thick ascending limb cell.

    Science.gov (United States)

    Nieves-González, Aniel; Clausen, Chris; Marcano, Mariano; Layton, Anita T; Layton, Harold E; Moore, Leon C

    2013-03-15

    Thick ascending limb (TAL) cells are capable of reducing tubular fluid Na(+) concentration to as low as ~25 mM, and yet they are thought to transport Na(+) efficiently owing to passive paracellular Na(+) absorption. Transport efficiency in the TAL is of particular importance in the outer medulla where O(2) availability is limited by low blood flow. We used a mathematical model of a TAL cell to estimate the efficiency of Na(+) transport and to examine how tubular dilution and cell volume regulation influence transport efficiency. The TAL cell model represents 13 major solutes and the associated transporters and channels; model equations are based on mass conservation and electroneutrality constraints. We analyzed TAL transport in cells with conditions relevant to the inner stripe of the outer medulla, the cortico-medullary junction, and the distal cortical TAL. At each location Na(+) transport efficiency was computed as functions of changes in luminal NaCl concentration ([NaCl]), [K(+)], [NH(4)(+)], junctional Na(+) permeability, and apical K(+) permeability. Na(+) transport efficiency was calculated as the ratio of total net Na(+) transport to transcellular Na(+) transport. Transport efficiency is predicted to be highest at the cortico-medullary boundary where the transepithelial Na(+) gradient is the smallest. Transport efficiency is lowest in the cortex where luminal [NaCl] approaches static head.

  5. Improvement of aerodynamic characteristics of a thick airfoil with a vortex cell in sub- and transonic flow

    Science.gov (United States)

    Isaev, Sergey; Baranov, Paul; Popov, Igor; Sudakov, Alexander; Usachov, Alexander

    2017-03-01

    The modified SST model (2005) is verified using Rodi- Leschziner-Isaev's approach and the multiblock computational technologies are validated in the VP2/3 code on different-structure overlapping grids by comparing the numerical predictions with the experimental data on transonic flow around an NACA0012 airfoil at an angle of attack of 4o for M=0.7 and Re=4×106. It is proved that the aerodynamic characteristics of a thick (20% of the chord) MQ airfoil mounted at an angle of attack of 2o for Re=107 and over the Mach number range 0.3-0.55 are significantly improved because an almost circular small-size (0.12) vortex cell with a defined volumetric flow rate coefficient of 0.007 during slot suction has been located on the upper airfoil section and an intense trapped vortex has been formed in it. A detailed analysis of buffeting within the self-oscillatory regime of flow around the MQ airfoil with a vortex cell has demonstrated the periodic changes in local and integral characteristics; the lift and the aerodynamic efficiency remain quite high, but inferior to the similar characteristics at M=0.55. It is found that the vortex cell at M=0.7 is inactive, and the aerodynamic characteristics of the MQ airfoil with a vortex cell are close to those of a smooth airfoil without a cell.

  6. An explicit algorithm for fully flexible unit cell simulation with recursive thermostat chains.

    Science.gov (United States)

    Jung, Kwangsub; Cho, Maenghyo

    2008-10-28

    Through the combination of the recursive multiple thermostat (RMT) Nose-Poincare and Parrinello-Rahman methods, the recursive multiple thermostat chained fully flexible unit cell (RMT-NsigmaT) molecular dynamics method is proposed for isothermal-isobaric simulation. The RMT method is known to have the advantage of achieving the ergodicity that is required for canonical sampling of the harmonic oscillator. Thus, an explicit time integration algorithm is developed for RMT-NsigmaT. We examine the ergodicity for various parameters of RMT-NsigmaT using bulk and thin film structures with different numbers of copper atoms and thicknesses in various environments. Through the numerical simulations, we conclude that the RMT-NsigmaT method is advantageous in the cases of lower temperatures.

  7. Zeroing in on red blood cell unit expiry.

    Science.gov (United States)

    Ayyalil, Fathima; Irwin, Greg; Ross, Bryony; Manolis, Michael; Enjeti, Anoop K

    2017-09-20

    Expiry of red blood cell (RBC) units is a significant contributor to wastage of precious voluntary donations. Effective strategies aimed at optimal resource utilization are required to minimize wastage. This retrospective study analyzed the strategic measures implemented to reduce expiry of RBC units in an Australian tertiary regional hospital. The measures, which included inventory rearrangement, effective stock rotation, and the number of emergency courier services required during a 24-month period, were evaluated. There was no wastage of RBC units due to expiry over the 12 months after policy changes. Before these changes, approximately half of RBC wastage (261/511) was due to expiry. The total number of transfusions remained constant in this period and there was no increase in the use of emergency couriers. Policy changes implemented were decreasing the RBC inventory level by one-third and effective stock rotation and using a computerized system to link the transfusion services across the area. Effective stock rotation resulted in a reduction in older blood (>28 days) received in the main laboratory rotated from peripheral hospitals, down from 6%-41% to 0%-2.5%. Age-related expiry of blood products is preventable and can be significantly reduced by improving practices in the pathology service. This study provides proof of principle for "zero tolerance for RBC unit expiry" across a large networked blood banking service. © 2017 The Authors Transfusion published by Wiley Periodicals, Inc. on behalf of AABB.

  8. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Point features used for the top of the regional middle confining unit (base of Upper Floridan aquifer)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  9. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Point features used for the top of the regional middle confining unit (base of Upper Floridan aquifer), constrained

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  10. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Raster surface depicting the top of the regional middle confining unit (base of Upper Floridan aquifer)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  11. Evaluation of the Endothelial Cell Density and the Central Corneal Thickness in Pseudoexfoliation Syndrome and Pseudoexfoliation Glaucoma

    Directory of Open Access Journals (Sweden)

    Bożydar T. Tomaszewski

    2014-01-01

    Full Text Available Purpose. Evaluation of central corneal thickness (CCT and endothelial cell density (ECD in patients with senile cataract and coexisting pseudoexfoliation (PEX syndrome with glaucoma (PEXG and without glaucoma using specular microscopy. Participants and Methods. The study included 122 patients (217 eyes. In this group of patients we identified 133 eyes with PEX syndrome (65 with glaucoma, 68 without glaucoma and 84 eyes without PEX syndrome. ECD and CCT were measured in each eye by specular microscopy. Results. ECD in eyes with PEX syndrome without glaucoma (2297 ± 359 cell/mm2 and in eyes with PEXG (2241 ± 363 cell/mm2 was lower than in the control group (2503 ± 262 cell/mm2 (P<0.001. CCT in eyes with PEXG (508.2 ± 32.6 μm was thinner than in eyes with PEX syndrome without glaucoma (529.7 ± 30.3 μm and control group (527.7 ± 29.4 μm (P<0.001. Conclusions. This research shows that in eyes with PEX syndrome, both with and without glaucoma, ECD was statistically significantly lower than in the control group. In patients with PEXG, CCT was statistically significantly thinner than in the PEX syndrome and control group.

  12. Quantitative assessment of rat corneal thickness and morphology during stem cell therapy by high-speed optical coherence tomography

    Science.gov (United States)

    Lal, Cerine; McGrath, James; Subhash, Hrebesh; Rani, Sweta; Ritter, Thomas; Leahy, Martin

    2016-03-01

    Optical Coherence Tomography (OCT) is a non-invasive 3 dimensional optical imaging modality that enables high resolution cross sectional imaging in biological tissues and materials. Its high axial and lateral resolution combined with high sensitivity, imaging depth and wide field of view makes it suitable for wide variety of high resolution medical imaging applications at clinically relevant speed. With the advent of swept source lasers, the imaging speed of OCT has increased considerably in recent years. OCT has been used in ophthalmology to study dynamic changes occurring in the cornea and iris, thereby providing physiological and pathological changes that occur within the anterior segment structures such as in glaucoma, during refractive surgery, lamellar keratoplasty and corneal diseases. In this study, we assess the changes in corneal thickness in the anterior segment of the eye during wound healing process in a rat corneal burn model following stem cell therapy using high speed swept source OCT.

  13. Anosmin-1 over-expression regulates oligodendrocyte precursor cell proliferation, migration and myelin sheath thickness.

    Science.gov (United States)

    Murcia-Belmonte, Verónica; Esteban, Pedro F; Martínez-Hernández, José; Gruart, Agnès; Luján, Rafael; Delgado-García, José María; de Castro, Fernando

    2016-04-01

    During development of the central nervous system, anosmin-1 (A1) works as a chemotropic cue contributing to axonal outgrowth and collateralization, as well as modulating the migration of different cell types, fibroblast growth factor receptor 1 (FGFR1) being the main receptor involved in all these events. To further understand the role of A1 during development, we have analysed the over-expression of human A1 in a transgenic mouse line. Compared with control mice during development and in early adulthood, A1 over-expressing transgenic mice showed an enhanced oligodendrocyte precursor cell (OPC) proliferation and a higher number of OPCs in the subventricular zone and in the corpus callosum (CC). The migratory capacity of OPCs from the transgenic mice is increased in vitro due to a higher basal activation of ERK1/2 mediated through FGFR1 and they also produced more myelin basic protein (MBP). In vivo, the over-expression of A1 resulted in an elevated number of mature oligodendrocytes with higher levels of MBP mRNA and protein, as well as increased levels of activation of the ERK1/2 proteins, while electron microscopy revealed thicker myelin sheaths around the axons of the CC in adulthood. Also in the mature CC, the nodes of Ranvier were significantly longer and the conduction velocity of the nerve impulse in vivo was significantly increased in the CC of A1 over-expressing transgenic mice. Altogether, these data confirmed the involvement of A1 in oligodendrogliogenesis and its relevance for myelination.

  14. Temperature field, H{sub 2} and H{sub 2}O mass transfer in SOFC single cell: Electrode and electrolyte thickness effects

    Energy Technology Data Exchange (ETDEWEB)

    Zitouni, Bariza; Moussa, Hocine Ben; Saighi, Slimane [Laboratoire d' etude des systemes energetiques industriels (LESEI), Universite de Batna, Batna (Algeria); Oulmi, Kafia [Laboratoire de chimie et de chimie de l' environnement, Universite de Batna, Batna (Algeria); Chetehouna, Khaled [Laboratoire Energetique Explosions Structures (LEES). ENSI, Bourges (France)

    2009-06-15

    The temperature increment in electrodes and electrolyte of a fuel cell is mainly attributed to the chemical reaction and the irreversibilities. The aim of this work is to study the increasing temperature of a SOFC single cell under the influence of the electrode and electrolyte thicknesses for its type of heat source. The hydrogen and water field are also discussed according to anode thickness. The results of a self-developed mathematical model show the increasing temperature in the solid side of SOFC; anode, electrolyte and cathode by heat source types ''Joule effect'' at the several geometric configurations of SOFC. The maximum temperature value is also discussed for several cathode thicknesses under the activation polarization effect. Moreover, mass transfer for both hydrogen and water is studied according to anode thickness. (author)

  15. A randomized trial comparing ReCell system of epidermal cells delivery versus classic skin grafts for the treatment of deep partial thickness burns.

    Science.gov (United States)

    Gravante, G; Di Fede, M C; Araco, A; Grimaldi, M; De Angelis, B; Arpino, A; Cervelli, V; Montone, A

    2007-12-01

    Our purpose was to directly compare results obtained with the ReCell system and the classic skin grafting for epidermal replacement in deep partial thickness burns. We recruited all patients with deep partial thickness burns admitted at the Burn Centre of S. Eugenio Hospital in Rome over 2 years. Enrollment was conducted with a controlled strategy--sampling chart--that allowed homogeneous groups (ReCell and skin grafting) for age, gender, type of burns and total burn surface area (TBSA). We evaluated as primary endpoints of the study the (i) time for complete epithelization (both treated area and biopsy site) and (ii) aesthetic and functional quality of the epithelization (color, joint contractures). Secondary endpoints were the assessment of infections, inflammations or any adverse effects of the ReCell procedure, particular medications assumed, postoperative pain. Eighty-two patients were analyzed in two homogeneous groups. All of them received adequate epidermal replacement, but skin grafting was faster than ReCell (pskin grafting but, harvesting minor areas, can open possible future applications in the management of large-burns patients.

  16. Effects of a trapped vortex cell on a thick wing airfoil

    Energy Technology Data Exchange (ETDEWEB)

    Lasagna, Davide; Iuso, Gaetano [Politecnico di Torino, Dipartimento di Ingegneria Aeronautica e Spaziale, Torino (Italy); Donelli, Raffaele; De Gregorio, Fabrizio [Centro Italiano di Ricerca Aerospaziale (C.I.R.A), Capua (Italy)

    2011-11-15

    The effects of a trapped vortex cell (TVC) on the aerodynamic performance of a NACA0024 wing model were investigated experimentally at Re = 10{sup 6} and 6.67 x 10{sup 5}. The static pressure distributions around the model and the wake velocity profiles were measured to obtain lift and drag coefficients, for both the clean airfoil and the controlled configurations. Suction was applied in the cavity region to stabilize the trapped vortex. For comparison, a classical boundary layer suction configuration was also tested. The drag coefficient curve of the TVC-controlled airfoil showed sharp discontinuities and bifurcative behavior, generating two drag modes. A strong influence of the angle of attack, the suction rate and the Reynolds number on the drag coefficient was observed. With respect to the clean airfoil, the control led to a drag reduction only if the suction was high enough. Compared to the classical boundary layer suction configuration, the drag reduction was higher for the same amount of suction only in a specific range of incidence, i.e., {alpha} = -2 to {alpha} = 6 and only for the higher Reynolds number. For all the other conditions, the classical boundary layer suction configuration gave better drag performances. Moderate increments of lift were observed for the TVC-controlled airfoil at low incidence, while a 20% lift enhancement was observed in the stall region with respect to the baseline. However, the same lift increments were also observed for the classical boundary layer suction configuration. Pressure fluctuation measurements in the cavity region suggested a very complex interaction of several flow features. The two drag modes were characterized by typical unsteady phenomena observed in rectangular cavity flows, namely the shear layer mode and the wake mode. (orig.)

  17. Flow field measurements in the cell culture unit

    Science.gov (United States)

    Walker, Stephen; Wilder, Mike; Dimanlig, Arsenio; Jagger, Justin; Searby, Nancy

    2002-01-01

    The cell culture unit (CCU) is being designed to support cell growth for long-duration life science experiments on the International Space Station (ISS). The CCU is a perfused loop system that provides a fluid environment for controlled cell growth experiments within cell specimen chambers (CSCs), and is intended to accommodate diverse cell specimen types. Many of the functional requirements depend on the fluid flow field within the CSC (e.g., feeding and gas management). A design goal of the CCU is to match, within experimental limits, all environmental conditions, other than the effects of gravity on the cells, whether the hardware is in microgravity ( micro g), normal Earth gravity, or up to 2g on the ISS centrifuge. In order to achieve this goal, two steps are being taken. The first step is to characterize the environmental conditions of current 1g cell biology experiments being performed in laboratories using ground-based hardware. The second step is to ensure that the design of the CCU allows the fluid flow conditions found in 1g to be replicated from microgravity up to 2g. The techniques that are being used to take these steps include flow visualization, particle image velocimetry (PIV), and computational fluid dynamics (CFD). Flow visualization using the injection of dye has been used to gain a global perspective of the characteristics of the CSC flow field. To characterize laboratory cell culture conditions, PIV is being used to determine the flow field parameters of cell suspension cultures grown in Erlenmeyer flasks on orbital shakers. These measured parameters will be compared to PIV measurements in the CSCs to ensure that the flow field that cells encounter in CSCs is within the bounds determined for typical laboratory experiments. Using CFD, a detailed simulation is being developed to predict the flow field within the CSC for a wide variety of flow conditions, including microgravity environments. Results from all these measurements and analyses of the

  18. Effect of laser energy, substrate film thickness and bioink viscosity on viability of endothelial cells printed by Laser-Assisted Bioprinting

    Science.gov (United States)

    Catros, Sylvain; Guillotin, Bertrand; Bačáková, Markéta; Fricain, Jean-Christophe; Guillemot, Fabien

    2011-04-01

    Biofabrication of three dimensional tissues by Laser-Assisted Bioprinting (LAB) implies to develop specific strategies for assembling the extracellular matrix (ECM) and cells. Possible strategies consist in (i) printing cells onto or in the depth of ECM layer and/or (ii) printing bioinks containing both cells and ECM-like printable biomaterial. The aim of this article was to evaluate combinatorial effects of laser pulse energy, ECM thickness and viscosity of the bioink on cell viability. A LAB workstation was used to print Ea.hy926 endothelial cells onto a quartz substrate covered with a film of ECM mimicking Matrigel™. Hence, effect of laser energy, Matrigel™ film thickness and bioink viscosity was addressed for different experimental conditions (8-24 μJ, 20-100 μm and 40-110 mPa s, respectively). Cell viability was assessed by live/dead assay performed 24 h post-printing. Results show that increasing the laser energy tends to augment the cell mortality while increasing the thickness of the Matrigel™ film and the viscosity of the bioink support cell viability. Hence, critical printing parameters influencing high cell viability have been related to the cell landing conditions and more specifically to the intensity of the cell impacts occurring at the air-ECM interface and at the ECM-glass interface.

  19. An investigation of two-dimensional ultrasound carotid plaque presence and intima media thickness in middle-aged South Asian and European men living in the United kingdom.

    Directory of Open Access Journals (Sweden)

    Nazim Ghouri

    Full Text Available Ultrasound studies of carotid intima media thickness (cIMT and plaques are limited in South Asians, a group at elevated cardiovascular disease (CVD risk. We determined whether South Asians have a difference in these ultrasound markers compared to Europeans living in the United Kingdom and whether measured risk factor(s could account for any such differences.One hundred South Asian men, aged 40 to 70 years and 100 European men of similar age and BMI, without diagnosed CVD or diabetes, underwent carotid ultrasound for measurement of cIMT and carotid plaque presence. Physical activity, cardiorespiratory fitness, anthropometry and blood pressure were assessed, fasted blood taken for measurement of cardiometabolic risk factors and demographic and lifestyle factors recorded.Age-adjusted mean (SD cIMT was similar in South Asians and Europeans (0.64 (0.16 mm v 0.65 (0.12 mm, p = 0.64. Plaque was present in 48 South Asians and 37 Europeans and overall, there was no age-adjusted difference between South Asian and Europeans for plaque score(odds ratio 1.49, 95% CI, 0.86-2.80, p = 0.16, however, South Asians appeared to have more plaques at a younger age than Europeans; at age 40-50 years the odds of South Asians having plaques was 2.63 (95% CI, 1.16-5.93 times that for Europeans.cIMT is similar between healthy South Asian and European men. Whilst there was no overall difference in plaque presence in South Asians, there is an indication of greater plaque prevalence at younger ages--an observation requiring further investigation. Prospective studies linking plaques to CVD outcomes in South Asians are needed to investigate whether these measures help improve CVD risk prediction.

  20. Optimization of dye adsorption time and film thickness for efficient ZnO dye-sensitized solar cells with high at-rest stability.

    Science.gov (United States)

    Chang, Wei-Chen; Lee, Chia-Hua; Yu, Wan-Chin; Lin, Chun-Min

    2012-12-28

    Photoelectrodes for dye-sensitized solar cells were fabricated using commercially available zinc oxide (ZnO) nanoparticles and sensitized with the dye N719. This study systematically investigates the effects of two fabrication factors: the ZnO film thickness and the dye adsorption time. Results show that these two fabrication factors must be optimized simultaneously to obtain efficient ZnO/N719-based cells. Different film thicknesses require different dye adsorption times for optimal cell performance. This is because a prolonged dye adsorption time leads to a significant deterioration in cell performance. This is contrary to what is normally observed for titanium dioxide-based cells. The highest overall power conversion efficiency obtained in this study was 5.61%, which was achieved by 26-μm-thick photoelectrodes sensitized in a dye solution for 2 h. In addition, the best-performing cell demonstrated remarkable at-rest stability despite the use of a liquid electrolyte. Approximately 70% of the initial efficiency remained after more than 1 year of room-temperature storage in the dark. To better understand how dye adsorption time affects electron transport properties, this study also investigated cells based on 26-μm-thick films using electrochemical impedance spectroscopy (EIS). The EIS results show good agreement with the measured device performance parameters.

  1. Mechanical behavior of regular open-cell porous biomaterials made of diamond lattice unit cells.

    Science.gov (United States)

    Ahmadi, S M; Campoli, G; Amin Yavari, S; Sajadi, B; Wauthle, R; Schrooten, J; Weinans, H; Zadpoor, A A

    2014-06-01

    Cellular structures with highly controlled micro-architectures are promising materials for orthopedic applications that require bone-substituting biomaterials or implants. The availability of additive manufacturing techniques has enabled manufacturing of biomaterials made of one or multiple types of unit cells. The diamond lattice unit cell is one of the relatively new types of unit cells that are used in manufacturing of regular porous biomaterials. As opposed to many other types of unit cells, there is currently no analytical solution that could be used for prediction of the mechanical properties of cellular structures made of the diamond lattice unit cells. In this paper, we present new analytical solutions and closed-form relationships for predicting the elastic modulus, Poisson׳s ratio, critical buckling load, and yield (plateau) stress of cellular structures made of the diamond lattice unit cell. The mechanical properties predicted using the analytical solutions are compared with those obtained using finite element models. A number of solid and porous titanium (Ti6Al4V) specimens were manufactured using selective laser melting. A series of experiments were then performed to determine the mechanical properties of the matrix material and cellular structures. The experimentally measured mechanical properties were compared with those obtained using analytical solutions and finite element (FE) models. It has been shown that, for small apparent density values, the mechanical properties obtained using analytical and numerical solutions are in agreement with each other and with experimental observations. The properties estimated using an analytical solution based on the Euler-Bernoulli theory markedly deviated from experimental results for large apparent density values. The mechanical properties estimated using FE models and another analytical solution based on the Timoshenko beam theory better matched the experimental observations. Copyright © 2014 Elsevier Ltd

  2. Evaluation of the retinal nerve fibre layer and ganglion cell complex thickness in pituitary macroadenomas without optic chiasmal compression

    Science.gov (United States)

    Cennamo, G; Auriemma, R S; Cardone, D; Grasso, L F S; Velotti, N; Simeoli, C; Di Somma, C; Pivonello, R; Colao, A; de Crecchio, G

    2015-01-01

    Purpose The aim of this prospective study was to measure the thickness of the circumpapillary retinal nerve fibre layer (cpRNFL) and the ganglion cell complex (GCC) using spectral domain optical coherence tomography (SD-OCT) in a cohort of consecutive de novo patients with pituitary macroadenomas without chiasmal compression. Patients and methods Twenty-two consecutive patients with pituitary macroadenoma without chiasmal compression (16 men, 6 women, aged 45.2±14.6 years, 43 eyes) entered the study between September 2011 and June 2013. Among them, 31.8% harboured a growth hormone-secreting pituitary adenoma, 27.3% a prolactin-secreting pituitary adenoma, 27.3% a corticotrophin-secreting pituitary adenoma, and 13.6% a non-secreting pituitary tumour. Eighteen subjects (nine females, nine males, mean age 36.47±6.37 years; 33 eyes) without pituitary adenoma, with normal ophthalmic examination, served as controls. In both patients and controls, cpRNFL and GCC thicknesses were measured by SD-OCT. Results Patients were significantly older (P=0.02) than controls. Best corrected visual acuity, intraocular pressure, colour fundus photography, and automatic perimetry test were within the normal range in patients and controls. Conversely, cpRNFL (P=0.009) and GCC (P<0.0001) were significantly thinner in patients than in controls. The average GCC (r=0.306, P=0.046) significantly correlated with the presence of arterial hypertension. OCT parameters did not differ significantly between patients with a tumour volume above the median and those with a tumour volume below the median. Conclusion Pituitary macroadenomas, even in the absence of chiasmal compression, may induce GCC and retinal nerve fibre layer thinning. SD-OCT may have a role in the early diagnosis and management of patients with pituitary tumours. PMID:25853400

  3. Extracting Information about the Electronic Quality of Organic Solar-Cell Absorbers from Fill Factor and Thickness

    Science.gov (United States)

    Kaienburg, Pascal; Rau, Uwe; Kirchartz, Thomas

    2016-08-01

    Understanding the fill factor in organic solar cells remains challenging due to its complex dependence on a multitude of parameters. By means of drift-diffusion simulations, we thoroughly analyze the fill factor of such low-mobility systems and demonstrate its dependence on a collection coefficient defined in this work. We systematically discuss the effect of different recombination mechanisms, space-charge regions, and contact properties. Based on these findings, we are able to interpret the thickness dependence of the fill factor for different experimental studies from the literature. The presented model provides a facile method to extract the photoactive layer's electronic quality which is of particular importance for the fill factor. We illustrate that over the past 15 years, the electronic quality has not been continuously improved, although organic solar-cell efficiencies increased steadily over the same period of time. Only recent reports show the synthesis of polymers for semiconducting films of high electronic quality that are able to produce new efficiency records.

  4. Association between Optic Nerve Head Microcirculation and Macular Ganglion Cell Complex Thickness in Eyes with Untreated Normal Tension Glaucoma and a Hemifield Defect

    Directory of Open Access Journals (Sweden)

    Ayako Anraku

    2017-01-01

    Full Text Available Purpose. We evaluated the association between optic nerve head (ONH microcirculation and macular ganglion cell complex (mGCC thickness in patients with untreated normal tension glaucoma (NTG and a hemifield defect. Methods. The medical records of 47 patients with untreated NTG were retrospectively reviewed. Laser speckle flowgraphy was used to obtain mean blur rate (MBR, a relative measure of blood flow. Average total deviation (TD, mGCC, and the circumpapillary retinal nerve fiber layer (cpRNFL thickness were also analyzed. Results. All parameters corresponding to the defective hemifield were significantly lower than those corresponding to the normal hemifield. In the defective hemifield, MBR was correlated with TD, mGCC, and cpRNFL thickness. In the normal hemifield, MBR was only correlated with mGCC thickness, and multiple regression analysis showed that mGCC thickness was a significant contributing factor of the MBR. Conclusion. MBR was well correlated with mGCC thickness in eyes with untreated NTG and a hemifield defect. In the normal hemifield, mGCC thickness was a contributing factor of the MBR indicating that ONH circulatory dysfunction may be associated with retinal structural changes in the early stages of glaucoma. A reduction in ONH microcirculation may be an early indicator of the presence and progression of glaucoma.

  5. Effect of thickness on physical properties of electron beam vacuum evaporated CdZnTe thin films for tandem solar cells

    Science.gov (United States)

    Chander, Subhash; Dhaka, M. S.

    2016-10-01

    The thickness and physical properties of electron beam vacuum evaporated CdZnTe thin films have been optimized in the present work. The films of thickness 300 nm and 400 nm were deposited on ITO coated glass substrates and subjected to different characterization tools like X-ray diffraction (XRD), UV-Vis spectrophotometer, source meter and scanning electron microscopy (SEM) to investigate the structural, optical, electrical and surface morphological properties respectively. The XRD results show that the as-deposited CdZnTe thin films have zinc blende cubic structure and polycrystalline in nature with preferred orientation (111). Different structural parameters are also evaluated and discussed. The optical study reveals that the optical transition is found to be direct and energy band gap is decreased for higher thickness. The transmittance is found to increase with thickness and red shift observed which is suitable for CdZnTe films as an absorber layer in tandem solar cells. The current-voltage characteristics of deposited films show linear behavior in both forward and reverse directions as well as the conductivity is increased for higher film thickness. The SEM studies show that the as-deposited CdZnTe thin films are found to be homogeneous, uniform, small circle-shaped grains and free from crystal defects. The experimental results confirm that the film thickness plays an important role to optimize the physical properties of CdZnTe thin films for tandem solar cell applications as an absorber layer.

  6. Porous silicon for micro-sized fuel cell reformer units

    Energy Technology Data Exchange (ETDEWEB)

    Presting, H.; Konle, J.; Starkov, V.; Vyatkin, A.; Koenig, U

    2004-04-25

    Randomly, self-organized and ordered anodically etched porous silicon with pore sizes down to hundred nanometers have been fabricated for a variety of automotive applications which range from carrier structures in fuel cell technology up to shower heads for fuel injection in combustion engines. The porous wafers are produced by deep anodic etching which is a very effective and cheap fabrication method compatible to standard Si CMOS fabrication technology. The density of nano- (and micro-) pores can be varied in a wide range by choice of substrate doping level and appropriate electrolyte solution. Surface enlargement up to a factor of 1000 can be achieved [J. Electrochem. Soc. 149 (1) (2002) G70]. After deposition of a catalyst on the inner surface of the pores these structures can be used as an effective catalytic reaction area for the injected hydrocarbons in a micro-steam reformer unit with a small reaction volume. In addition deep anodic etching (DAE) of a pinhole array with very high aspect ratios is demonstrated using a pre-patterned inverted pyramidal array which is produced by lithography and subsequent wet chemical potassium hydroxide (KOH) etch. The structures can also be used as carrier structures for the hydrogen separation membrane of the reforming gas in a reformer unit when a thin layer of palladium is evaporated prior to the anodic etching of the pores. The noble metal foil serves as anode contact during the etch as well as hydrogen separating membrane of the device.

  7. Hydrogeologic framework bottom elevations and thicknesses of Permian, Upper Pennsylvanian, Lower Pennsylvanian, and Mississippian units in the Appalachian Plateaus Physiographic Province

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — As part of the U.S. Geological Survey Water Availability and Use Science Program study of Appalachian Plateaus aquifers, bottom elevations and thicknesses were...

  8. The Effect of LASIK Procedure on Peripapillary Retinal Nerve Fiber Layer and Macular Ganglion Cell-Inner Plexiform Layer Thickness in Myopic Eyes

    Directory of Open Access Journals (Sweden)

    Maja Zivkovic

    2017-01-01

    Full Text Available Purpose. To evaluate the effect of applied suction during microkeratome-assisted laser in situ keratomileusis (LASIK procedure on peripapillary retinal nerve fiber layer (RNFL thickness as well as macular ganglion cell-inner plexiform layer (GC-IPL thickness. Methods. 89 patients (124 eyes with established myopia range from −3.0 to −8.0 diopters and no associated ocular diseases were included in this study. RNFL and GC-IPL thickness measurements were performed by spectral domain optical coherence tomography (SD OCT one day before LASIK and at 1 and 6 months postoperatively. Results. Mean RNFL thickness prior to LASIK was 93.86±12.17 μm while the first month and the sixth month postoperatively were 94.01±12.04 μm and 94.46±12.27 μm, respectively. Comparing results, there is no significant difference between baseline, one month, and six months postoperatively for mean RNFL (p>0.05. Mean GC-IPL thickness was 81.70±7.47 μm preoperatively with no significant difference during the follow-up period (82.03±7.69 μm versus 81.84±7.64 μm; p>0.05. Conclusion. RNFL and GC-IPL complex thickness remained unaffected following LASIK intervention.

  9. Investigating electro-optical properties of a nematic liquid crystal cell with planar anchoring boundary condition for various thicknesses: A Monte Carlo study

    Science.gov (United States)

    Emül, Yakup; Polat, Ömer; San, Sait Eren; Kayacan, Özhan; Özbek, Haluk

    2014-06-01

    Monte Carlo (MC) simulations and the Mueller matrix formalism were applied to investigate electro optical properties of a LC cell with planar boundary conditions for various thicknesses. Field dependent global order parameter and the optical transmissions were analyzed in common. Three characteristic regions of the periodicity of optical transmissions as a function of polarizer angle and the external field were identified.

  10. Macular Retinal Ganglion Cell Complex Thickness and Its Relationship to the Optic Nerve Head Topography in Glaucomatous Eyes with Hemifield Defects

    Directory of Open Access Journals (Sweden)

    Seiji T. Takagi

    2011-01-01

    Full Text Available Purpose. To evaluate the relationship between the macular ganglion cell complex (mGCC thickness, which is the sum of the retinal nerve fiber, ganglion cell, and inner plexiform layers, measured with a spectral-domain optical coherence tomograph and the optic nerve head topography measured with a confocal scanning laser ophthalmoscope in glaucomatous eyes with visual field defects localized predominantly to either hemifield. Materials and Methods. The correlation between the mGCC thickness in hemispheres corresponding to hemifields with and without defects (damaged and intact hemispheres, respectively and the optic nerve head topography corresponding to the respective hemispheres was evaluated in 18 glaucomatous eyes. Results. The mGCC thickness was significantly correlated with the rim volume, mean retinal nerve fiber layer thickness, and cross-sectional area of the retinal nerve fiber layer in both the intact and the damaged hemispheres (P<.05. Discussion. For detecting very early glaucomatous damage of the optic nerve, changes in the thicknesses of the inner retina in the macular area and peripapillary RNFL as well as rim volume changes in the optic nerve head are target parameters that should be carefully monitored.

  11. Technical advance: Langerhans cells derived from a human cell line in a full-thickness skin equivalent undergo allergen-induced maturation and migration.

    Science.gov (United States)

    Ouwehand, Krista; Spiekstra, Sander W; Waaijman, Taco; Scheper, Rik J; de Gruijl, Tanja D; Gibbs, Susan

    2011-11-01

    In this report, the construction of a functional, immunocompetent, full-thickness skin equivalent (SE) is described, consisting of an epidermal compartment containing keratinocytes, melanocytes, and human LCs derived from the MUTZ-3 cell line (MUTZ-LC) and a fibroblast-populated dermal compartment. The CD1a(+)Langerin(+)HLA-DR(+) MUTZ-LCs populate the entire epidermis at a similar density to that found in native skin. Exposure of the SE to subtoxic concentrations of the allergens NiSO(4) and resorcinol resulted in LC migration out of the epidermis toward the fibroblast-populated dermal compartment. A significant dose-dependent up-regulation of the DC maturation-related CCR7 and IL-1β transcripts and of CD83 at the protein level upon epidermal exposure to both allergens was observed, indicative of maturation and migration of the epidermally incorporated LC. We have thus successfully developed a reproducible and functional full-thickness SE model containing epidermal MUTZ-LC. This model offers an alternative to animal testing for identifying potential chemical sensitizers and for skin-based vaccination strategies and provides a unique research tool to study human LC biology in situ under controlled in vitro conditions.

  12. Optimization of High-Efficiency CdS/CdTe Thin Film Solar Cell Using Step Doping Grading and Thickness of the Absorption Layer

    OpenAIRE

    Masoud Sabaghi; Abbas Majdabadi; Saeid Marjani; Saeed Khosroabadi

    2015-01-01

    In this paper, the influence of stepped doping of the absorber layer on performance of Cadmium Sulfide/Cadmium Telluride (CdS/CdTe) solar cell has been investigated. At first, the electrical characteristics of conventional CdS/CdTe solar cell is validated with fabricated CdS/CdTe solar cell. To improve the maximum efficiency of CdS/CdTe solar cell, the doping and thickness of the absorption layer are optimized. By step doping concentration within the absorber layer using buffer layer back con...

  13. Hydrodynamic film thickness measurements and CFD analysis identify the root causes of repetitive thrust bearing failures on a 45 MW hydro generating unit at Hydro-Québec

    Science.gov (United States)

    Gauvin, P.; Huard, P.

    2016-11-01

    High temperature level recorded on the thrust bearing of a 45 MW hydro generating unit was resulting in frequent production stoppage. In spite of improvements brought to the oil cooling system since the rehabilitation in 2008, the operator had to activate the bearing oil lift system to keep the temperature below acceptable limits. Primary root cause analysis first pointed to the design of the shoe that was centrally pivoted, not allowing the formation of a thick hydrodynamic film. The removal of a strip of the soft metal layer near the trailing edge of the shoe resulted in a significant surface temperature reduction (about 15 deg. C), as predicted by a CFD model of the oil film. The goal of this machining was to increase the pivoting angle by moving the centre of hydrodynamic pressure. Proximity sensors were installed at each corner of the redesigned shoe to measure the film thickness and the bearing attitude. Signal analysis revealed a step of a magnitude close to the oil film thickness between the two halves of the rotating thrust block. This was the cause of another failure few hours since restarting the unit. The lessons learnt through these measurements and analyses were carefully applied to the ultimate build. The unit now runs with a robust thrust bearing and even survived a significant cooling flow reduction event. This paper presents the CFD analysis results and the measurements acquired during these events.

  14. Device and performance parameters of Cu(In,Ga)(Se,S){sub 2}-based solar cells with varying i-ZnO layer thickness

    Energy Technology Data Exchange (ETDEWEB)

    Macabebe, E.Q.B. [Department of Physics, Nelson Mandela Metropolitan University, P.O. Box 77000, Port Elizabeth 6031 (South Africa); Sheppard, C.J. [Department of Physics, University of Johannesburg, P.O. Box 524, Auckland Park 2006 (South Africa); Dyk, E.E. van, E-mail: ernest.vandyk@nmmu.ac.z [Department of Physics, Nelson Mandela Metropolitan University, P.O. Box 77000, Port Elizabeth 6031 (South Africa)

    2009-12-01

    In pursuit of low-cost and highly efficient thin film solar cells, Cu(In,Ga)(Se,S){sub 2}/CdS/i-ZnO/ZnO:Al (CIGSS) solar cells were fabricated using a two-step process. The thickness of i-ZnO layer was varied from 0 to 454 nm. The current density-voltage (J-V) characteristics of the devices were measured, and the device and performance parameters of the solar cells were obtained from the J-V curves to analyze the effect of varying i-ZnO layer thickness. The device parameters were determined using a parameter extraction method that utilized particle swarm optimization. The method is a curve-fitting routine that employed the two-diode model. The J-V curves of the solar cells were fitted with the model and the parameters were determined. Results show that as the thickness of i-ZnO was increased, the average efficiency and the fill factor (FF) of the solar cells increase. Device parameters reveal that although the series resistance increased with thicker i-ZnO layer, the solar cells absorbed more photons resulting in higher short-circuit current density (J{sub sc}) and, consequently, higher photo-generated current density (J{sub L}). For solar cells with 303-454 nm-thick i-ZnO layer, the best devices achieved efficiency between 15.24% and 15.73% and the fill factor varied between 0.65 and 0.67.

  15. Regeneration of full-thickness skin defects by differentiated adipose-derived stem cells into fibroblast-like cells by fibroblast-conditioned medium.

    Science.gov (United States)

    Hur, Woojune; Lee, Hoon Young; Min, Hye Sook; Wufuer, Maierdanjiang; Lee, Chang-Won; Hur, Ji An; Kim, Sang Hyon; Kim, Byeung Kyu; Choi, Tae Hyun

    2017-04-20

    Fibroblasts are ubiquitous cells in the human body and are absolutely necessary for wound healing such as for injured skin. This role of fibroblasts was the reason why we aimed to differentiate human adipose-derived stem cells (hADSCs) into fibroblasts and to test their wound healing potency. Recent reports on hADSC-derived conditioned medium have indicated stimulation of collagen synthesis as well as migration of dermal fibroblasts in wound sites with these cells. Similarly, human fibroblast-derived conditioned medium (F-CM) was reported to contain a variety of factors known to be important for growth of skin. However, it remains unknown whether and how F-CM can stimulate hADSCs to secrete type I collagen. In this study, we obtained F-CM from the culture of human skin fibroblast HS27 cells in DMEM media. For an in-vivo wound healing assay using cell transplantation, balb/c nude mice with full-thickness skin wound were used. Our data showed that levels of type I pro-collagen secreted by hADSCs cultured in F-CM increased significantly compared with hADSCs kept in normal medium for 72 h. In addition, from a Sircol collagen assay, the amount of collagen in F-CM-treated hADSC conditioned media (72 h) was markedly higher than both the normal medium-treated hADSC conditioned media (72 h) and the F-CM (24 h). We aimed to confirm that hADSCs in F-CM would differentiate into fibroblast cells in order to stimulate wound healing in a skin defect model. To investigate whether F-CM induced hADSCs into fibroblast-like cells, we performed FACS analysis and verified that both F-CM-treated hADSCs and HS27 cells contained similar expression patterns for CD13, CD54, and CD105, whereas normal medium-treated hADSCs were significantly different. mRNA level  analysis for Nanog, Oct4A, and Sox2 as undifferentiation markers and vimentin, HSP47, and desmin as matured fibroblast markers supported the characterization that hADSCs in F-CM were highly differentiated into fibroblast

  16. Dependence of Photovoltaic Property of ZnO/Si Heterojunction Solar Cell on Thickness of ZnO Films

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wei-Ying; ZHONG Sheng; SUN Li-Jie; FU Zhu-Xi

    2008-01-01

    N-ZnO/p-Si heterojunctions are prepared by sputtering deposition of intrinsic ZnO films on p-Si substrates.Thicknesses of ZnO films are altered by varying the deposition time from I h to 3 h.The electrical properties of these structures are analysed from capacitance-voltage ( C- V) and current-voltage (I- V) characteristics performed in a dark room.The results demonstrated that all the samples show strong rectifying behaviour.Photovoltalc property for the samples with different thicknesses of ZnO films are investigated by measuring open circuit voltage and short circuit current.It is found that photovoltages are kept to be almost constant of 32OmV along with the thickness while photocurrents changing a lot.The variation mechanism of the photovoltalc effect as a function of thickness of ZnO films is investigated.

  17. Super Unit Cells in Aperture-Based Metamaterials

    Directory of Open Access Journals (Sweden)

    Dragan Tanasković

    2015-01-01

    Full Text Available An important class of electromagnetic metamaterials are aperture-based metasurfaces. Examples include extraordinary optical transmission arrays and double fishnets with negative refractive index. We analyze a generalization of such metamaterials where a simple aperture is now replaced by a compound object formed by superposition of two or more primitive objects (e.g., rectangles, circles, and ellipses. Thus obtained “super unit cell” shows far richer behavior than the subobjects that comprise it. We show that nonlocalities introduced by overlapping simple subobjects can be used to produce large deviations of spectral dispersion even for small additive modifications of the basic geometry. Technologically, some super cells may be fabricated by simple spatial shifting of the existing photolithographic masks. In our investigation we applied analytical calculations and ab initio finite element modeling to prove the possibility to tailor the dispersion including resonances for plasmonic nanocomposites by adjusting the local geometry and exploiting localized interactions at a subwavelength level. Any desired form could be defined using simple primitive objects, making the situation a geometrical analog of the case of series expansion of a function. Thus an additional degree of tunability of metamaterials is obtained. The obtained designer structures can be applied in different fields like waveguiding and sensing.

  18. Effect of Yttria Content on the Zirconia Unit Cell Parameters

    Energy Technology Data Exchange (ETDEWEB)

    Krogstad, Jessica A.; Lepple, Maren; Gao, Yan; Lipkin, Don M.; Levi, Carlos G. (UCSB); (GE Global)

    2012-02-06

    The relationship between yttria concentration and the unit cell parameters in partially and fully stabilized zirconia has been reassessed, motivated by the need to improve the accuracy of phase analysis upon decomposition of t{prime}-based thermal barrier coatings. Compositions ranging from 6 to 18 mol% YO{sub 1.5} were synthesized and examined by means of high-resolution X-ray diffraction. Lattice parameters were determined using the Rietveld refinement method, a whole-pattern fitting procedure. The revised empirical relationships fall within the range of those published previously. However, efforts to achieve superior homogeneity of the materials, as well as accuracy of the composition and lattice parameters, provide increased confidence in the reliability of these correlations for use in future studies. Additional insight into the potential sources for scatter previously reported for the transition region ({approx}12-14 mol% YO{sub 1.5}), where tetragonal and cubic phases have been observed to coexist, is also provided. Implications on the current understanding of stabilization mechanisms in zirconia are discussed.

  19. The effects of InGaN layer thickness on the performance of InGaN/GaN p-i-n solar cells

    Institute of Scientific and Technical Information of China (English)

    Li Liang; Zhao De-Gang; Jiang De-Sheng; Liu Zong-Shun; Chen Ping; Wu Liang-Liang; Le Ling-Cong

    2013-01-01

    InGaN/GaN p-i-n solar cells,each with an undoped Ino.12Gao.88N absorption layer,are grown on c-plane sapphire substrates by metal-organic chemical vapor deposition.The effects of the thickness and dislocation density of the absorption layer on the collection efficiency of InGaN-based solar cells are analyzed,and the experimental results demonstrate that the thickness of the InGaN layer and the dislocation density significantly affect the performance.An optimized InGaN-based solar cell with a peak external quantum efficiency of 57% at a wavelength of 371 nm is reported.The full width at half maximum of the rocking curve of the (0002) InGaN layer is 180 arcsec.

  20. High vancomycin MICs within the susceptible range in Staphylococcus aureus bacteraemia isolates are associated with increased cell wall thickness and reduced intracellular killing by human phagocytes.

    Science.gov (United States)

    Falcón, Rocío; Martínez, Alba; Albert, Eliseo; Madrid, Silvia; Oltra, Rosa; Giménez, Estela; Soriano, Mario; Vinuesa, Víctor; Gozalbo, Daniel; Gil, María Luisa; Navarro, David

    2016-05-01

    Vancomycin minimum inhibitory concentrations (MICs) at the upper end of the susceptible range for Staphylococcus aureus have been associated with poor clinical outcomes of bloodstream infections. We tested the hypothesis that high vancomycin MICs in S. aureus bacteraemia isolates are associated with increased cell wall thickness and suboptimal bacterial internalisation or lysis by human phagocytes. In total, 95 isolates were evaluated. Original vancomycin MICs were determined by Etest. The susceptibility of S. aureus isolates to killing by phagocytes was assessed in a human whole blood assay. Internalisation of bacterial cells by phagocytes was investigated by flow cytometry. Cell wall thickness was evaluated by transmission electron microscopy. Genotypic analysis of S. aureus isolates was performed using a DNA microarray system. Vancomycin MICs were significantly higher (P=0.006) in isolates that were killed suboptimally (killing index 70%) and tended to correlate inversely (P=0.08) with the killing indices. Isolates in both killing groups were internalised by human neutrophils and monocytes with comparable efficiency. The cell wall was significantly thicker (P=0.03) in isolates in the low killing group. No genotypic differences were found between the isolates in both killing groups. In summary, high vancomycin MICs in S. aureus bacteraemia isolates were associated with increased cell wall thickness and reduced intracellular killing by phagocytes.

  1. Thickness Effect of Al-Doped ZnO Window Layer on Damp-Heat Stability of CuInGaSe2 Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Pern, F. J.; Mansfield, L.; DeHart, C.; Glick, S. H.; Yan, F.; Noufi, R.

    2011-01-01

    We investigated the damp heat (DH) stability of CuInGaSe{sub 2} (CIGS) solar cells as a function of thickness of the Al-doped ZnO (AZO) window layer from the 'standard' 0.12 {micro}m to a modest 0.50 {micro}m over an underlying 0.10-{micro}m intrinsic ZnO buffer layer. The CIGS cells were prepared with external electrical contact using fine Au wire to the tiny 'standard' Ni/Al (0.05 {micro}m/3 {micro}m) metal grid contact pads. Bare cell coupons and sample sets encapsulated in a specially designed, Al-frame test structure with an opening for moisture ingress control using a TPT backsheet were exposed to DH at 85 C and 85% relative humidity, and characterized by current-voltage (I-V), quantum efficiency (QE), and (electrochemical) impedance spectroscopy (ECIS). The results show that bare cells exhibited rapid degradation within 50-100 h, accompanied by film wrinkling and delamination and corrosion of Mo and AlNi grid, regardless of AZO thickness. In contrast, the encapsulated cells did not show film wrinkling, delamination, and Mo corrosion after 168 h DH exposure; but the trend of efficiency degradation rate showed a weak correlation to the AZO thickness.

  2. Thickness Effect of Al-Doped ZnO Window Layer on Damp Heat Stability of CuInGaSe2 Solar Cells: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Pern, F. J.; Mansfield, L.; DeHart, C.; Glick, S. H.; Yan, F.; Noufi, R.

    2011-07-01

    We investigated the damp heat (DH) stability of CuInGaSe2 (CIGS) solar cells as a function of thickness of the Al-doped ZnO (AZO) window layer from the 'standard' 0.12 μm to a modest 0.50 μm over an underlying 0.10-μm intrinsic ZnO buffer layer. The CIGS cells were prepared with external electrical contact using fine Au wire to the tiny 'standard' Ni/Al (0.05 μm/3 μm) metal grid contact pads. Bare cell coupons and sample sets encapsulated in a specially designed, Al-frame test structure with an opening for moisture ingress control using a TPT backsheet were exposed to DH at 85oC and 85% relative humidity, and characterized by current-voltage (I-V), quantum efficiency (QE), and (electrochemical) impedance spectroscopy (ECIS). The results show that bare cells exhibited rapid degradation within 50-100 h, accompanied by film wrinkling and delamination and corrosion of Mo and AlNi grid, regardless of AZO thickness. In contrast, the encapsulated cells did not show film wrinkling, delamination, and Mo corrosion after 168 h DH exposure; but the trend of efficiency degradation rate showed a weak correlation to the AZO thickness.

  3. Evaluating the Critical Thickness of TiO 2 Layer on Insulating Mesoporous Templates for Efficient Current Collection in Dye-Sensitized Solar Cells

    KAUST Repository

    Chandiran, Aravind Kumar

    2013-01-15

    In this paper, a way of utilizing thin and conformal overlayer of titanium dioxide on an insulating mesoporous template as a photoanode for dye-sensitized solar cells is presented. Different thicknesses of TiO2 ranging from 1 to 15 nm are deposited on the surface of the template by atomic layer deposition. This systematic study helps unraveling the minimum critical thickness of the TiO2 overlayer required to transport the photogenerated electrons efficiently. A merely 6-nm-thick TiO2 film on a 3-μm mesoporous insulating substrate is shown to transport 8 mA/cm 2 of photocurrent density along with ≈900 mV of open-circuit potential when using our standard donor-π-acceptor sensitizer and Co(bipyridine) redox mediator. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Cell Churches and Stem Cell Marketing in South Korea and the United States.

    Science.gov (United States)

    Sipp, Douglas

    2016-05-23

    The commercial provision of putative stem cell-based medical interventions in the absence of conclusive evidence of safety and efficacy has formed the basis of an unregulated industry for more than a decade. Many clinics offering such supposed stem cell treatments include statements about the 'ethical' nature of somatic (often colloquially referred to as 'adult' stem cells) stem cells, in specific contrast to human embryonic stem cells (hESCs), which have been the subject of intensive political, legal, and religious controversy since their first derivation in 1998. Christian groups-both Roman Catholic and evangelical Protestant-in many countries have explicitly promoted the medical potential and current-day successes in the clinical application of somatic stem cells, lending indirect support to the activities of businesses marketing stem cells ahead of evidence. In this article, I make a preliminary examination of how the structures and belief systems of certain churches in South Korea and the United States, both of which are home to significant stem cell marketing industries, has complemented other factors, including national biomedical funding initiatives, international economic rivalries, permissive legal structures, which have lent impetus to a problematic and often exploitative sector of biomedical commerce.

  5. Single fibre and multifibre unit cell analysis of strength and cracking of unidirectional composites

    DEFF Research Database (Denmark)

    Wang, H.W.; Zhou, H.W.; Mishnaevsky, Leon

    2009-01-01

    Numerical simulations of damage evolution in composites reinforced with single and multifibre are presented. Several types of unit cell models are considered: single fibre unit cell, multiple fibre unit cell with one and several damageable sections per fibres, unit cells with homogeneous...... damageable parts in composites (matrix cracks, fibre/matrix interface damage and fibre fracture) was observed in the simulations. The strength of interface begins to influence the deformation behaviour of the cell only after the fibre is broken. In this case, the higher interface layer strength leads...... and inhomogeneous interfaces, etc. Two numerical damage models, cohesive elements, and damageable layers are employed for the simulation of the damage evolution in single fibre and multifibre unit cells. The two modelling approaches were compared and lead to the very close results. Competition among the different...

  6. Evaluation of Macular Retinal Ganglion Cell-Inner Plexiform Layer Thickness after Vitrectomy with Internal Limiting Membrane Peeling for Idiopathic Macular Holes

    Directory of Open Access Journals (Sweden)

    Alfonso L. Sabater

    2014-01-01

    Full Text Available Purpose. To evaluate macular retinal ganglion cell-inner plexiform layer (GCIPL thickness changes after Brilliant Blue G-assisted internal limiting membrane peeling for idiopathic macular hole repair using a high-resolution spectral-domain optical coherence tomography (SD-OCT. Methods. 32 eyes from 32 patients with idiopathic macular holes who underwent vitrectomy with internal limiting membrane peeling between January 2011 and July 2012 were retrospectively analyzed. GCIPL thickness was measured before surgery, and at one month and at six months after surgery. Values obtained from automated and semimanual SD-OCT segmentation analysis were compared (Cirrus HD-OCT, Carl Zeiss Meditec, Dublin, CA. Results. No significant differences were found between average GCIPL thickness values between preoperative and postoperative analysis. However, statistical significant differences were found in GCIPL thickness at the temporal macular quadrants at six months after surgery. Quality measurement analysis performed by automated segmentation revealed a significant number of segmentation errors. Semimanual segmentation slightly improved the quality of the results. Conclusion. SD-OCT analysis of GCIPL thickness found a significant reduction at the temporal macular quadrants at 6 months after Brilliant Blue G-assisted internal limiting membrane peeling for idiopathic macular hole.

  7. Evaluation of Macular Retinal Ganglion Cell-Inner Plexiform Layer Thickness after Vitrectomy with Internal Limiting Membrane Peeling for Idiopathic Macular Holes

    Science.gov (United States)

    Velázquez-Villoria, Álvaro; Zapata, Miguel A.; Figueroa, Marta S.; Suárez-Leoz, Marta; Arrevola, Luis; Teijeiro, María-Ángeles; García-Layana, Alfredo

    2014-01-01

    Purpose. To evaluate macular retinal ganglion cell-inner plexiform layer (GCIPL) thickness changes after Brilliant Blue G-assisted internal limiting membrane peeling for idiopathic macular hole repair using a high-resolution spectral-domain optical coherence tomography (SD-OCT). Methods. 32 eyes from 32 patients with idiopathic macular holes who underwent vitrectomy with internal limiting membrane peeling between January 2011 and July 2012 were retrospectively analyzed. GCIPL thickness was measured before surgery, and at one month and at six months after surgery. Values obtained from automated and semimanual SD-OCT segmentation analysis were compared (Cirrus HD-OCT, Carl Zeiss Meditec, Dublin, CA). Results. No significant differences were found between average GCIPL thickness values between preoperative and postoperative analysis. However, statistical significant differences were found in GCIPL thickness at the temporal macular quadrants at six months after surgery. Quality measurement analysis performed by automated segmentation revealed a significant number of segmentation errors. Semimanual segmentation slightly improved the quality of the results. Conclusion. SD-OCT analysis of GCIPL thickness found a significant reduction at the temporal macular quadrants at 6 months after Brilliant Blue G-assisted internal limiting membrane peeling for idiopathic macular hole. PMID:25110679

  8. Highly efficient and thickness-tolerable bulk heterojunction polymer solar cells based on P3HT donor and a low-bandgap non-fullerene acceptor

    Science.gov (United States)

    Liu, Xiaodong; Li, Yongxi; Huang, Peng; Zhou, Yi; Jiang, Zuo-Quan; Song, Bo; Li, Yongfang; Liao, Liang-Sheng; Zheng, Yonghao

    2017-10-01

    In order to fabricate highly efficient polymer solar cells (PSCs) in industrial scale, one of the key issues is to use thick active layer (>200 nm) in the device module without sacrificing the power conversion efficiency (PCE). In this article, we have studied the blend of the medium-bandgap polymeric donor P3HT and the low-bandgap acceptor IDTIDT-IC as the active layer in non-fullerene PSCs, and successfully maintained the device performance with the thickness of the active layer close to 250 nm. The P3HT:IDTIDT-IC based PSCs with simple thermal annealing exhibits a PCE of 3.49% at a thin active layer, 74 nm. More importantly, the PCE remains almost constant with increasing the thickness of the active layer, and reaches a peak value of 3.64% at 236 nm. This thickness-insensitive photovoltaic performance of the P3HT:IDTIDT-IC system makes them compatible with large-scale roll-to-roll processing. Furthermore, the P3HT:IDTIDT-IC devices show a very high tolerance to temperature, and the PCE keeps nearly unchanged after annealing the active layer at 150 °C for 75 min. All in all, our results show that thickness-tolerable and thermal-stable P3HT:IDTIDT-IC system is more suitable for large-scale industrial manufacturing than the classic P3HT:PCBM formula.

  9. Automated assembling of single fuel cell units for use in a fuel cell stack

    Science.gov (United States)

    Jalba, C. K.; Muminovic, A.; Barz, C.; Nasui, V.

    2017-05-01

    The manufacturing of PEMFC stacks (POLYMER ELEKTROLYT MEMBRAN Fuel Cell) is nowadays still done by hand. Over hundreds of identical single components have to be placed accurate together for the construction of a fuel cell stack. Beside logistic problems, higher total costs and disadvantages in weight the high number of components produce a higher statistic interference because of faulty erection or material defects and summation of manufacturing tolerances. The saving of costs is about 20 - 25 %. Furthermore, the total weight of the fuel cells will be reduced because of a new sealing technology. Overall a one minute cycle time has to be aimed per cell at the manufacturing of these single components. The change of the existing sealing concept to a bonded sealing is one of the important requisites to get an automated manufacturing of single cell units. One of the important steps for an automated gluing process is the checking of the glue application by using of an image processing system. After bonding the single fuel cell the sealing and electrical function can be checked, so that only functional and high qualitative cells can get into further manufacturing processes.

  10. Effect of TiO2 thickness on nanocomposited aligned ZnO nanorod/TiO2 for dye-sensitized solar cells

    Science.gov (United States)

    Saurdi, I.; Shafura, A. K.; Azhar, N. E. A.; Ishak, A.; Malek, M. F.; Alrokayan, A. H. Salman; Khan, Haseeb A.; Mamat, M. H.; Rusop, M.

    2016-07-01

    The TiO2 films were deposited on glass substrate at different thicknesses with different deposition frequencies (1, 2, 3 and 4 times) using spin coating technique and their structural properties were investigated. Subsequently, the nanocomposited aligned ZnO nanorods and TiO2 were formed by deposited the TiO2 on top of aligned ZnO Nanorod on ITO-coated glass at different thicknesses using the same method of TiO2 deposited on glass substrate. The nanocomposited aligned ZnO nanorod/TiO2 were coated with different thicknesses of 900µm, 1815µm, 2710µm, 3620µm and ZnO without TiO2. The dye-sensitized solar cells were fabricated from the nanocomposited aligned ZnO nanorod/TiO2 with thickness of 900µm, 1815µm, 2710µm and 3620µm and ZnO without TiO2 and their photovoltaic properties of the DSSCs were investigated. From the solar simulator measurement the solar energy conversion efficiency (η) of 2.543% under AM 1.5 was obtained for the ZnO nanorod/TiO2 photoanode-2710µm Dye-Sensitized solar cell.

  11. Unit cell geometry of multiaxial preforms for structural composites

    Science.gov (United States)

    Ko, Frank; Lei, Charles; Rahman, Anisur; Du, G. W.; Cai, Yun-Jia

    1993-01-01

    The objective of this study is to investigate the yarn geometry of multiaxial preforms. The importance of multiaxial preforms for structural composites is well recognized by the industry but, to exploit their full potential, engineering design rules must be established. This study is a step in that direction. In this work the preform geometry for knitted and braided preforms was studied by making a range of well designed samples and studying them by photo microscopy. The structural geometry of the preforms is related to the processing parameters. Based on solid modeling and B-spline methodology a software package is developed. This computer code enables real time structural representations of complex fiber architecture based on the rule of preform manufacturing. The code has the capability of zooming and section plotting. These capabilities provide a powerful means to study the effect of processing variables on the preform geometry. the code also can be extended to an auto mesh generator for downstream structural analysis using finite element method. This report is organized into six sections. In the first section the scope and background of this work is elaborated. In section two the unit cell geometries of braided and multi-axial warp knitted preforms is discussed. The theoretical frame work of yarn path modeling and solid modeling is presented in section three. The thin section microscopy carried out to observe the structural geometry of the preforms is the subject in section four. The structural geometry is related to the processing parameters in section five. Section six documents the implementation of the modeling techniques into the computer code MP-CAD. A user manual for the software is also presented here. The source codes and published papers are listed in the Appendices.

  12. Obtention of polymeric membrane fuel cells by low pressure plasma technique: Evaluation of total cell efficiency by function on the amount of platinum and the thickness of the deposited carbon support

    Science.gov (United States)

    Moreira, A. J.; Ordonez, N.; Mansano, R. D.

    2015-03-01

    This work aimed to obtain catalytic support over polymeric membrane building a fuel cell using low pressure plasma technique. For this, polymeric membranes were coated with carbon layer and platinum nanoparticles. The procedures were performed in separate steps in order to obtain firstly carbon layer and catalytic platinum nanoparticles. In the first step, the plasma processes were carried methane in order to obtain carbon layer over the polymeric membrane. At this stage, in order to obtain different thicknesses, were made several processes, reaching a thickness of 0.36μm to 1.4μm. The second step was to get the platinum nanoparticles on the carbon layer. For this, was used a platinum solid source and argon plasma. The study relied primarily on assessing the influence of the carbon layer on the performance of fuel cell. Compared with the commercial processes, it was observed that the results for fuel cells obtained by plasma have a better electric contact on three cell layers (catalyst - electrolyte - reagent). By electrochemical activity test was possible observe increase of reverse voltage of 0.8 volts to 1.24 volts according to increase the thickness of the carbon layer. The same behavior was also observed in the analysis of total efficiency, which was limited to 50% of maximum efficiency of commercial cell due the thickness of the carbon layer deposited during the preparation of this study, indicating a greater thickness with carbon it is possible to achieve the same efficiency of cells better than commercial.

  13. X-ray powder diffraction data and unit cells of ammonium paratungstate tetrahydrate

    NARCIS (Netherlands)

    Put, J.W. van; Verkroost, T.W.; Sonneveld, E.J.

    1990-01-01

    X-Ray powder diffraction data and unit cell parameters of industrially produced, as well as bench scale prepared, ammonium paratungstate tetrahydrate are reported and compared with current Powder Data file (PDF) (1989) patterns. A least-squares refinement resulted in two slightly different unit cell

  14. Thickness and concentration effect of P3HT in P3HT:graphene nanocomposites based bulk-heterojunction organic solar cells

    Science.gov (United States)

    Shariff, Nur Shakina Mohd; Saad, Puteri Sarah Mohamad; Affendi, Irma Hidayanti Halim; Mahmood, Mohamad Rusop; Shariffudin, Shafinaz Sobihana

    2016-07-01

    There has been an increasing interest towards organic solar cells after the discovery of conjugated polymer and bulk-heterojunction concept. Eventhough organic solar cells are less expensive than inorganic solar cells but the power conversion energy is still considered low. The main objective of this research is to investigate the effect of the P3HT's thickness and concentration towards the efficiency of the P3HT:Graphene solar cells. A simulation software that is specialize for photovoltaic called SCAPS is used in this research to simulate the effect on the solar cells. The solar cell's structure will be drawn inside the simulation and the parameters for each layers is inserted. The result such as the open circuit voltage (Voc), short circuit current density (Jsc), fill factor (FF) and efficiency (η) will be calculated by the software and all the results will be put into one graph. P3HT's thickness of 100 nm and concentration of 1×1016 cm-3 has the best overall results with an open circuit voltage (Voc) of 4.55 V, short circuit current density (Jsc) of 16.76 mA/cm2, fill factor (FF) of 19.70 % and efficiency (η) about 15.03 %. The conclusions from the results is that the thicker the active layer and the more higher the concentration, the higher the efficiency of the solar cells.

  15. Effect of ZnTe and CdZnTe Alloys at the Back Contact of 1-μm-Thick CdTe Thin Film Solar Cells

    Science.gov (United States)

    Amin, Nowshad; Yamada, Akira; Konagai, Makoto

    2002-05-01

    N2-doped ZnTe was introduced onto 1-μm-thick CdTe absorbers in order to reduce the carrier recombination at the back contact of CdS/CdTe/C/Ag configuration solar cells. ZnTe films were grown by molecular beam epitaxy (MBE) on GaAs and Corning glass substrates to investigate the characteristics of the films. Epitaxial growth of ZnTe was realized on GaAs substrates and a hole concentration of 8 × 1018 cm-3 with a resistivity of 0.045 Ω \\cdotcm was achieved as a result of nitrogen doping. In contrast, polycrystalline ZnTe films were grown on Corning glass and CdTe thin films. Dark and photoconductivity of ZnTe films increased to 1.43 × 10-5 S/cm and 1.41 × 10-4 S/cm, respectively, while the Zn to Te ratio was decreased to 0.25 during MBE growth. These ZnTe films with different thicknesses were inserted into close-spaced sublimation (CSS)-grown 1-μm-thick CdTe solar cells. A conversion efficiency of 8.31% (Voc: 0.74 V, Jsc: 22.98 mA/cm2, FF: 0.49, area: 0.5 cm2) was achieved for a 0.2-μm-thick ZnTe layer with a cell configuration of CdS/CdTe/ZnTe/Cu-doped-C/Ag. Furthermore, to overcome the problem of possible recombination loss in the interface layer of CdTe and ZnTe, the intermediate ternary CdZnTe is investigated. The compositional factor in Cd1-xZnxTe:N alloy is varied and the dependence of the conductivity is evaluated. For instance, Cd0.5Zn0.5Te:N, with dark and photoconductivity of 2.13 × 10-6 and 2.9 × 10-5 S/cm, respectively, is inserted at the back contact of a 1-μm-thick CdTe solar cell. A conversion efficiency of 7.46% (Voc: 0.68 V, Jsc: 22.60 mA/cm2, FF: 0.49, area: 0.086 cm2) was achieved as the primary result for a 0.2-μm-thick Cd0.5Zn0.5Te:N layer with the cell configuration of CdS/CdTe/Cd0.5Zn0.5Te:N/Au.

  16. In vivo thickness measurement of basal cell carcinoma and actinic keratosis with optical coherence tomography and 20-MHz ultrasound

    DEFF Research Database (Denmark)

    Mogensen, Mette; Nürnberg, B.M.; Forman, J.L.

    2009-01-01

    was measured with a colorimeter. Results OCT presented narrower limits of agreement than HFUS. Both methods overestimated thickness but OCT was significantly less biased (0Æ392 mm vs. 0Æ713 mm). No relation between OCT penetration depth and skin colour was found. Conclusions OCT appears more precise and less......Background Accurate assessment of tumour size is important when planning treatment of nonmelanoma skin cancer (NMSC). Imaging with optical coherence tomography (OCT) has the potential to diagnose and measure depth of NMSC. Objectives To compare accuracy of mean tumour thickness measurement in NMSC...... tumours penetration depth in OCT images was estimated. Methods In total, 93 patients were scanned...

  17. Illumination angle and layer thickness influence on the photo current generation in organic solar cells: A combined simulative and experimental study

    Directory of Open Access Journals (Sweden)

    Jan Mescher

    2015-07-01

    Full Text Available In most future organic photovoltaic applications, such as fixed roof installations, facade or clothing integration, the solar cells will face the sun under varying angles. By a combined simulative and experimental study, we investigate the mutual interdependencies of the angle of light incidence, the absorber layer thickness and the photon harvesting efficiency within a typical organic photovoltaic device. For thin absorber layers, we find a steady decrease of the effective photocurrent towards increasing angles. For 90-140 nm thick absorber layers, however, we observe an effective photocurrent enhancement, exhibiting a maximum yield at angles of incidence of about 50°. Both effects mainly originate from the angle-dependent spatial broadening of the optical interference pattern inside the solar cell and a shift of the absorption maximum away from the metal electrode.

  18. Modeling the increase in aerodynamic efficiency for a thick (37.5% chord) airfoil with slot suction in vortex cells with allowance for the compressibility effect

    Science.gov (United States)

    Isaev, S. A.; Baranov, P. A.; Sudakov, A. G.; Ermakov, A. M.

    2015-01-01

    The Reynolds equations closed using the Menter shear-stress-transfer model modified with allowance for the curvature of flow lines have been numerically solved using multiblock computational technologies. The obtained solution has been used to analyze subsonic flow past a thick (37.5% chord) airfoil with slot suction in circular vortex cells intended for the Ecology and Progress (Ekologiya i Progress, EKIP) aircraft project in comparison to a distributed (from the central body surface) suction at fixed values of the total volume flow rate (0.02121) and Reynolds number (105) in a range of Mach numbers from 0 to 0.4. This analysis revealed a significant (up to tenfold) decrease in the bow drag (determined with allowance for the energy losses) and a large (by an order of magnitude) increase in the aerodynamic efficiency of the thick airfoil containing vortex cells with slot suction, which reached up to 160.

  19. The effects of excessive mineral salts and vitamins on fiber cell thickness in flax (Linum usitatissimum L. cultivar Sarı 85)

    OpenAIRE

    DEMİRAY, Hatice; DEREBOYLU, Aylin EŞİZ

    2010-01-01

    The effects of mineral salts on fiber cell thickness in flax (Linum usitatissimum L. cultivar Sarı 85) were investigated in plants grown in medium both rich and poor in mineral salts and vitamins. Three media were investigated: control (MS medium), mineral salt and vitamin deficient MS medium, and mineral salt and vitamin rich MS medium. While chlorophyll a, chlorophyll b, total chlorophyll, and carotenoid pigment content significantly increased in the medium rich in mineral salts and vitamin...

  20. Dependence of lattice strain relaxation, absorbance, and sheet resistance on thickness in textured ZnO@B transparent conductive oxide for thin-film solar cell applications

    OpenAIRE

    2016-01-01

    The interplay of surface texture, strain relaxation, absorbance, grain size, and sheet resistance in textured, boron-doped ZnO (ZnO@B), transparent conductive oxide (TCO) materials of different thicknesses used for thin film, solar cell applications is investigated. The residual strain induced by the lattice mismatch and the difference in the thermal expansion coefficient for thicker ZnO@B is relaxed, leading to an increased surface texture, stronger absorbance, larger grain size, and lower s...

  1. Retinal nerve fiber layer and ganglion cell complex thickness assessment in patients with Alzheimer disease and mild cognitive impairment. Preliminary results

    Directory of Open Access Journals (Sweden)

    A. S. Tiganov

    2014-07-01

    Full Text Available Purpose: to investigate the retinal nerve fiber layer (RNFL and the macular ganglion cell complex (GCC in patients with Alzheimer`s disease and mild cognitive impairment.Methods: this study included 10 patients (20 eyes with Alzheimer`s disease, 10 patients with mild cognitive impairment and 10 age- and sex-matched healthy controls that had no history of dementia. All the subjects underwent psychiatric examination, including the Mini-Mental State Examination (MMSE, and complete ophthalmological examination, comprising optical coherence tomography and scanning laser polarimetry.Results: there was a significant decrease in GCC thickness in patients with Alzheimer`s disease compared to the control group, global loss volume of ganglion cells was higher than in control group. there was no significant difference among the groups in terms of RNFL thickness. Weak positive correlation of GCC thickness and MMSE results was observed.Conclusion: Our data confirm the retinal involvement in Alzheimer`s disease, as reflected by loss of ganglion cells. Further studies will clear up the role and contribution of dementia in pathogenesis of optic neuropathy.

  2. Map service: United States Decadal Production History Cells

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map service displays present and past oil and gas production in the United States, as well as the location and intensity of exploratory drilling outside...

  3. Absorption enhancement through Fabry-Pérot resonant modes in a 430 nm thick InGaAs/GaAsP multiple quantum wells solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Behaghel, B. [Laboratory for Photonics and Nanostructures (LPN–CNRS), Marcoussis 91460 (France); Institute of Research and Development on Photovoltaic Energy (IRDEP–CNRS), Chatou 78401 (France); NextPV, RCAST and CNRS, The University of Tokyo, Meguro-ku, Tokyo 153-8904 (Japan); Tamaki, R.; Watanabe, K.; Sodabanlu, H. [Research Center for Advanced Science and Technology (RCAST), The University of Tokyo, Meguro-ku, Tokyo 153-8904 (Japan); Vandamme, N.; Dupuis, C.; Bardou, N.; Cattoni, A. [Laboratory for Photonics and Nanostructures (LPN–CNRS), Marcoussis 91460 (France); Okada, Y. [NextPV, RCAST and CNRS, The University of Tokyo, Meguro-ku, Tokyo 153-8904 (Japan); Research Center for Advanced Science and Technology (RCAST), The University of Tokyo, Meguro-ku, Tokyo 153-8904 (Japan); Sugiyama, M. [NextPV, RCAST and CNRS, The University of Tokyo, Meguro-ku, Tokyo 153-8904 (Japan); School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656 (Japan); Collin, S. [Laboratory for Photonics and Nanostructures (LPN–CNRS), Marcoussis 91460 (France); NextPV, RCAST and CNRS, The University of Tokyo, Meguro-ku, Tokyo 153-8904 (Japan); Guillemoles, J.-F., E-mail: jf-guillemoles@chimie-paristech.fr [Institute of Research and Development on Photovoltaic Energy (IRDEP–CNRS), Chatou 78401 (France); NextPV, RCAST and CNRS, The University of Tokyo, Meguro-ku, Tokyo 153-8904 (Japan)

    2015-02-23

    We study light management in a 430 nm-thick GaAs p-i-n single junction solar cell with 10 pairs of InGaAs/GaAsP multiple quantum wells (MQWs). The epitaxial layer transfer on a gold mirror improves light absorption and increases the external quantum efficiency below GaAs bandgap by a factor of four through the excitation of Fabry-Perot resonances. We show a good agreement with optical simulation and achieve around 10% conversion efficiency. We demonstrate numerically that this promising result can be further improved by anti-reflection layers. This study paves the way to very thin MQWs solar cells.

  4. Dependence of lattice strain relaxation, absorbance, and sheet resistance on thickness in textured ZnO@B transparent conductive oxide for thin-film solar cell applications.

    Science.gov (United States)

    Kou, Kuang-Yang; Huang, Yu-En; Chen, Chien-Hsun; Feng, Shih-Wei

    2016-01-01

    The interplay of surface texture, strain relaxation, absorbance, grain size, and sheet resistance in textured, boron-doped ZnO (ZnO@B), transparent conductive oxide (TCO) materials of different thicknesses used for thin film, solar cell applications is investigated. The residual strain induced by the lattice mismatch and the difference in the thermal expansion coefficient for thicker ZnO@B is relaxed, leading to an increased surface texture, stronger absorbance, larger grain size, and lower sheet resistance. These experimental results reveal the optical and material characteristics of the TCO layer, which could be useful for enhancing the performance of solar cells through an optimized TCO layer.

  5. Numerical modeling of CdS/CdTe and CdS/CdTe/ZnTe solar cells as a function of CdTe thickness

    Energy Technology Data Exchange (ETDEWEB)

    Amin, Nowshad [Department of Electrical, Electronic and System Engineering, Faculty of Engineering, National University of Malaysia (UKM), Bangi 43600, Selangor D.E (Malaysia); Sopian, Kamaruzzaman [Solar Energy Research Institute, National University of Malaysia (UKM), Bangi 43600, Selangor D.E (Malaysia); Konagai, Makoto [Department of Electrical and Electronic Engineering, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo 152-8552 (Japan)

    2007-08-15

    CdTe-based solar cells have long been of interest for terrestrial usage because of their high potential conversion efficiency (in the range of 18-24%) with low-cost manufacturability and concern over environmental effects. In order to conserve material and address environmental pollution concerns as well as to reduce carrier recombination loss throughout the absorber layer, efforts have been carried out to decrease the thickness of the CdTe absorption layer to 1 {mu}m. As a result, to date, the experimental part of this study has realized cell efficiencies of 15.3% and 11.5% with 7 and 1.2-{mu}m-thick CdTe layers, grown by close-spaced sublimation (CSS) [N. Amin, T. Isaka, T. Okamoto, A. Yamada, M. Konagai, Jpn. J. Appl. Phys. 38 (8) (1999) 4666; N. Amin, T. Isaka, A. Yamada, M. Konagai, Sol. Energy Matter. Sol. Cells 67 (2001) 195]. Since some problems remain with such thin 1 {mu}m CdTe layers, possible methods to realize higher efficiency have been investigated using novel solar cell structures, with the help of numerical analyses tools. In the theory part of this study, numerical analysis with a 1-D simulation program named NSSP (Numerical Solar Cell Simulation Program) has been used to simulate these structures. We investigated the viability of CdTe thickness reduction to 1 {mu}m together with the insertion of higher band-gap materials (i.e., ZnTe) at the back contacts to reduce carrier recombination loss there. The study shows potential results of the thickness reduction of CdTe absorption layer for a conventional CdS/CdTe/Cu-doped C structure with around 16% efficiency for cells below 3 {mu}m CdTe. Decreases were found in spectral response that suggest from minority carrier recombination loss at the back contact interface. A higher band-gap material like ZnTe has been inserted to produce a back surface field (BSF) to inhibit the minority carrier loss at the back contact. An increase in the efficiency to about 20% has been found for a 1 {mu}m-thin CdTe cell

  6. Dependence of lattice strain relaxation, absorbance, and sheet resistance on thickness in textured ZnO@B transparent conductive oxide for thin-film solar cell applications

    Directory of Open Access Journals (Sweden)

    Kuang-Yang Kou

    2016-01-01

    Full Text Available The interplay of surface texture, strain relaxation, absorbance, grain size, and sheet resistance in textured, boron-doped ZnO (ZnO@B, transparent conductive oxide (TCO materials of different thicknesses used for thin film, solar cell applications is investigated. The residual strain induced by the lattice mismatch and the difference in the thermal expansion coefficient for thicker ZnO@B is relaxed, leading to an increased surface texture, stronger absorbance, larger grain size, and lower sheet resistance. These experimental results reveal the optical and material characteristics of the TCO layer, which could be useful for enhancing the performance of solar cells through an optimized TCO layer.

  7. Critical thickness for ferromagnetism in insulating LaMnO3 films

    Science.gov (United States)

    Renshaw Wang, X.; Poccia, N.; Leusink, D. P.; Paudel, Tura R.; Tsymbal, E. Y.; Li, C. J.; Lv, W. M.; Venkatesan, T.; Ariando, Ariando; Hilgenkamp, H.

    2014-03-01

    The interplay between exchange interactions, interfacial charges, and confinement effects controls the electronic, magnetic, and transport properties of complex oxide thin films. Here we report the emergence of ferromagnetism in insulating LaMnO3 thin films grown on SrTiO3 substrates beyond a critical thickness. LaMnO3 (001) films are deposited by a pulsed laser deposition technique with thicknesses varying from 1 unit cell to 24 unit cells. The position dependent local magnetization is then mapped with micrometer resolution using scanning superconducting quantum interference device microscopy. We find that the magnetic ground state switches from non-ferromagnetic to ferromagnetic within a change of one unit cell above the critical thickness of 5 unit cells with characteristic domain size of about 20 μm. Further increase of film thickness up to 24 unit cells leads to reduction of the domain size to about 10 μm. The critical thickness is qualitatively explained in terms of the charge transfer in polar LaMnO3 (001) thin films based on results of additional experimental data, density-functional calculations, and the electrostatic modeling.

  8. Size of the Optic Nerve Head and Its Relationship with the Thickness of the Macular Ganglion Cell Complex and Peripapillary Retinal Nerve Fiber Layer in Patients with Primary Open Angle Glaucoma

    Directory of Open Access Journals (Sweden)

    Nobuko Enomoto

    2015-01-01

    Full Text Available Purpose. To evaluate the relationships among the optic nerve head (ONH area, macular ganglion cell complex (mGCC thickness, circumpapillary retinal nerve fiber layer (cpRNFL thickness, and visual field defects in patients with primary open angle glaucoma (POAG. Methods. This retrospective study included 90 eyes of 90 patients with POAG. The ONH area, rim area, mGCC thickness, and cpRNFL thickness were measured using optical coherence tomography. Mean deviation (MD was measured using standard automated perimetry. The relationships among clinical factors including age, refraction, the ONH area, the rim area, the mGCC thickness, the cpRNFL thickness, and MD were evaluated using correlation coefficients and multiple regression analyses. Results. The significant correlation of the ONH area with refraction (r=0.362, P<0.001, the mGCC thickness (r=0.225, P=0.033, and the cpRNFL thickness (r=0.253, P=0.016 was found. Multiple regression analysis showed that the ONH area, rim area, and MD were selected as significant contributing factors to explain the mGCC thickness and cpRNFL thickness. No factor was selected to explain MD. Conclusions. The ONH area, in other words, the disc size itself may affect the mGCC thickness and cpRNFL thickness in POAG patients.

  9. Critical thickness and orbital ordering in ultrathin La0.7Sr0.3MnO3 films

    NARCIS (Netherlands)

    Huijben, M.; Martin, L.W.; Chu, Y.-H.; Holcomb, M.B.; Yu, P.; Rijnders, G.; Blank, D.H.A.; Ramesh, R.

    2008-01-01

    Detailed analysis of transport, magnetism, and x-ray absorption spectroscopy measurements on ultrathin La0.7Sr0.3MnO3 films with thicknesses from 3 to 70 unit cells resulted in the identification of a lower critical thickness for a nonmetallic nonferromagnetic layer at the interface with the SrTiO3

  10. Hydrogen Fuel Cell Performance as Telecommunications Backup Power in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Kurtz, Jennifer [National Renewable Energy Lab. (NREL), Golden, CO (United States); Saur, Genevieve [National Renewable Energy Lab. (NREL), Golden, CO (United States); Sprik, Sam [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2015-03-01

    Working in collaboration with the U.S. Department of Energy (DOE) and industry project partners, the National Renewable Energy Laboratory (NREL) acts as the central data repository for the data collected from real-world operation of fuel cell backup power systems. With American Recovery and Reinvestment Act of 2009 (ARRA) co-funding awarded through DOE's Fuel Cell Technologies Office, more than 1,300 fuel cell units were deployed over a three-plus-year period in stationary, material handling equipment, auxiliary power, and backup power applications. This surpassed a Fuel Cell Technologies Office ARRA objective to spur commercialization of an early market technology by installing 1,000 fuel cell units across several different applications, including backup power. By December 2013, 852 backup power units out of 1,330 fuel cell units deployed were providing backup service, mainly for telecommunications towers. For 136 of the fuel cell backup units, project participants provided detailed operational data to the National Fuel Cell Technology Evaluation Center for analysis by NREL's technology validation team. NREL analyzed operational data collected from these government co-funded demonstration projects to characterize key fuel cell backup power performance metrics, including reliability and operation trends, and to highlight the business case for using fuel cells in these early market applications. NREL's analyses include these critical metrics, along with deployment, U.S. grid outage statistics, and infrastructure operation.

  11. Influence of chemically p-type doped active organic semiconductor on the film thickness versus performance trend in cyanine/C60 bilayer solar cells

    Science.gov (United States)

    Jenatsch, Sandra; Geiger, Thomas; Heier, Jakob; Kirsch, Christoph; Nüesch, Frank; Paracchino, Adriana; Rentsch, Daniel; Ruhstaller, Beat; C Véron, Anna; Hany, Roland

    2015-01-01

    Simple bilayer organic solar cells rely on very thin coated films that allow for effective light absorption and charge carrier transport away from the heterojunction at the same time. However, thin films are difficult to coat on rough substrates or over large areas, resulting in adverse shorting and low device fabrication yield. Chemical p-type doping of organic semiconductors can reduce Ohmic losses in thicker transport layers through increased conductivity. By using a Co(III) complex as chemical dopant, we studied doped cyanine dye/C60 bilayer solar cell performance for increasing dye film thickness. For films thicker than 50 nm, doping increased the power conversion efficiency by more than 30%. At the same time, the yield of working cells increased to 80%. We addressed the fate of the doped cyanine dye, and found no influence of doping on solar cell long term stability. PMID:27877804

  12. Influence of chemically p-type doped active organic semiconductor on the film thickness versus performance trend in cyanine/C60 bilayer solar cells.

    Science.gov (United States)

    Jenatsch, Sandra; Geiger, Thomas; Heier, Jakob; Kirsch, Christoph; Nüesch, Frank; Paracchino, Adriana; Rentsch, Daniel; Ruhstaller, Beat; C Véron, Anna; Hany, Roland

    2015-06-01

    Simple bilayer organic solar cells rely on very thin coated films that allow for effective light absorption and charge carrier transport away from the heterojunction at the same time. However, thin films are difficult to coat on rough substrates or over large areas, resulting in adverse shorting and low device fabrication yield. Chemical p-type doping of organic semiconductors can reduce Ohmic losses in thicker transport layers through increased conductivity. By using a Co(III) complex as chemical dopant, we studied doped cyanine dye/C60 bilayer solar cell performance for increasing dye film thickness. For films thicker than 50 nm, doping increased the power conversion efficiency by more than 30%. At the same time, the yield of working cells increased to 80%. We addressed the fate of the doped cyanine dye, and found no influence of doping on solar cell long term stability.

  13. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Points and control points for the top of the 10,000 mg/L total dissolved solids boundary

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  14. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Extent of the low-permeable areas of the Floridan aquifer system in the Gulf Trough

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  15. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Well locations used in the development of the potentiometric surface map for the Upper Floridan aquifer in May 2010

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  16. A Micromechanical Unit Cell Model of 2 × 2 Twill Woven Fabric Textile Composite for Multi Scale Analysis

    Science.gov (United States)

    Dixit, A.; Mali, H. S.; Misra, R. K.

    2014-04-01

    Woven fabric based composite materials are being considered for potential structural applications in automotive and aircraft industries due to their better out of plane strength, stiffness and toughness properties than ordinary composite laminates. This paper presents the micromechanical unit cell model of 2 × 2 twill woven fabric textile composite for the estimation of in-plane elastic properties. Modelling of unit cell and its analysis for this new model is developed by using open source coded tool TexGen and finite element software, ABAQUS® respectively. The predicted values are in good agreement with the experimental results reported in literature. To ascertain the effectiveness of the developed model parametric studies have also been conducted on the predicted elastic properties in order to investigate the effects of various geometric parameters such as yarn spacing, fabric thickness, yarn width and fibre volume fraction. The scope of altering weave pattern and yarn characteristics is facilitated in this developed model. Further this model can be implemented for the multi-scale micro/macro-mechanical analysis for the calculation of strength and stiffness of laminates structure made of 2 × 2 twill composite.

  17. Advanced Composite Bipolar Plate for Unitized Regenerative Fuel Cell/Electrolyzer Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Development of an advanced composite bipolar plate is proposed for a unitized regenerative fuel cell and electrolyzer system that operates on pure feed streams...

  18. Super Unit Cells in Aperture-Based Metamaterials

    OpenAIRE

    Dragan Tanasković; Zoran Jakšić; Marko Obradov; Olga Jakšić

    2015-01-01

    An important class of electromagnetic metamaterials are aperture-based metasurfaces. Examples include extraordinary optical transmission arrays and double fishnets with negative refractive index. We analyze a generalization of such metamaterials where a simple aperture is now replaced by a compound object formed by superposition of two or more primitive objects (e.g., rectangles, circles, and ellipses). Thus obtained “super unit cell” shows far richer behavior than the subobjects that compris...

  19. Overview of commercialization of stationary fuel cell power plants in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Hooie, D.T.; Williams, M.C.

    1995-07-01

    In this paper, DOE`s efforts to assist private sector organizations to develop and commercialize stationary fuel cell power plants in the United States are discussed. The paper also provides a snapshot of the status of stationary power fuel cell development occurring in the US, addressing all fuel cell types. This paper discusses general characteristics, system configurations, and status of test units and demonstration projects. The US DOE, Morgantown Energy Technology Center is the lead center for implementing DOE`s program for fuel cells for stationary power.

  20. Dielectric Behavior of Low Microwave Loss Unit Cell for All Dielectric Metamaterial

    OpenAIRE

    Tianhuan Luo; Bo Li; Qian Zhao; Ji Zhou

    2015-01-01

    With a deep study of the metamaterial, its unit cells have been widely extended from metals to dielectrics. The dielectric based unit cells attract much attention because of the advantage of easy preparation, tunability, and higher frequency response, and so forth. Using the conventional solid state method, we prepared a kind of incipient ferroelectrics (calcium titanate, CaTiO3) with higher microwave permittivity and lower loss, which can be successfully used to construct metamaterials. The ...

  1. Recent insights into the cell biology of thyroid angiofollicular units.

    OpenAIRE

    Colin, Ides M.; Denef, Jean-François; Lengelé, Benoît; Many, Marie-Christine; Gérard, Anne-Catherine

    2013-01-01

    In thyrocytes, cell polarity is of crucial importance for proper thyroid function. Many intrinsic mechanisms of self-regulation control how the key players involved in thyroid hormone (TH) biosynthesis interact in apical microvilli, so that hazardous biochemical processes may occur without detriment to the cell. In some pathological conditions, this enzymatic complex is disrupted, with some components abnormally activated into the cytoplasm, which can lead to further morphological and functio...

  2. Optical investigation of shell thickness in light scattering SiO2 particle with TiO2 nanoshells and its application in dye sensitized solar cells

    Science.gov (United States)

    Falahatdoost, Samira; Ara, Mohammad Hossein Majles; Shaban, Zeinab; Ghazyani, Nahid

    2015-09-01

    Monodisperse SiO2@TiO2 core/shell submicron particles with specific core size and different shell thicknesses have been successfully synthesized by facile, controllable and reproducible method. The structure and morphology of samples were investigated by EDX, FESEM, FTIR and XRD. Analysis showed monodisperse SiO2 cores and SiO2@TiO2 particles, which are about 350 nm, 370 nm, 390 nm, 405 nm and 420 nm, respectively. DRS graphs of SiO2@TiO2 particles showed effective diffuse reflectance, which had been examined in dye sensitized solar cells as a back-scatterer. So they made 18% increases in cell efficiency compare to cell without back-scatterer.

  3. Prospects of Thickness Reduction of the CdTe Layer in Highly Efficient CdTe Solar Cells Towards 1 µm

    Science.gov (United States)

    Amin, Nowshad; Isaka, Takayuki; Okamoto, Tamotsu; Yamada, Akira; Konagai, Makoto

    1999-08-01

    This study focuses on the technique for the stable growth of CdTe (1.44 eV) with thickness near its absorption length, 1 µm, by close spaced sublimation (hereafter CSS) process, in order to achieve high conversion efficiency. X-ray diffraction (XRD) spectroscopy was carried out to examine the microstructure of the films. Current-voltage (I V) characteristics, spectral response and other features of the solar cells using these CdTe films were investigated to elucidate the optimum conditions for achieving the best performance in such thin (1 µm) CdTe solar cells. Thickness was found to be reduced by controlling the temperature profile used during CSS growth. The temperature profile was found to be an important factor in growing high-quality thin films. By controlling the growth parameters and optimizing the annealing temperature at different fabrication steps, we have succeeded, to date, in achieving cell efficiencies of 14.3% (open-circuit voltage (Voc): 0.82 V, short-circuit current (Jsc): 25.2 mA/cm2, fill factor (F.F.): 0.695, area: 1 cm2) with 5 µm, 11.4% (Voc: 0.77 V, Jsc: 23.7 mA/cm2, F.F.: 0.63, area: 1 cm2) with 1.5 µm and 11.2% (Voc: 0.77 V, Jsc: 23.1 mA/cm2, F.F.: 0.63, area: 1 cm2) with only 1 µm of CdTe layer thickness at an air mass of 1.5 without antireflection coatings. This is important for establishing a strong foundation before developing a new structure (e.g., glass/ITO/CdS/CdTe/ZnTe/Ag configuration) with a back surface field of wide-bandgap material (e.g., ZnTe).

  4. Refractive index extraction and thickness optimization of Cu2ZnSnSe4 thin film solar cells

    OpenAIRE

    ElAnzeery, Hossam; El Daif, Ounsi; Buffiere, Marie; Oueslati, Souhaib; Ben Messaoud, Khaled; Agten, Dries; Brammertz, Guy; Guindi, Rafik; Kniknie, Bas; Meuris, Marc; Poortmans, Jef

    2015-01-01

    Cu2ZnSnSe4 (CZTSe) thin film solar cells are promising emergent photovoltaic technologies based on low-bandgap absorber layer with high absorption coefficient. To reduce optical losses in such devices and thus improve their efficiency, numerical simulations of CZTSe solar cells optical characteristics can be performed based on individual optical properties of each layer present in the cell structure. In this contribution, we have first determined the optical coefficients of individual t...

  5. Dominant unit CD34+ cell dose predicts engraftment after double-unit cord blood transplantation and is influenced by bank practice.

    Science.gov (United States)

    Purtill, Duncan; Smith, Katherine; Devlin, Sean; Meagher, Richard; Tonon, Joann; Lubin, Marissa; Ponce, Doris M; Giralt, Sergio; Kernan, Nancy A; Scaradavou, Andromachi; Stevens, Cladd E; Barker, Juliet N

    2014-11-06

    We investigated the unit characteristics associated with engraftment after double-unit cord blood (CB) transplantation (dCBT) and whether these could be reliably identified during unit selection. Cumulative incidence of neutrophil engraftment in 129 myeloablative dCBT recipients was 95% (95% confidence interval: 90-98%). When precryopreservation characteristics were analyzed, the dominant unit CD34(+) cell dose was the only characteristic independently associated with engraftment (hazard ratio, 1.43; P = .002). When postthaw characteristics were also included, only dominant unit infused viable CD34(+) cell dose independently predicted engraftment (hazard ratio, 1.95; P banks were more likely to have low recovery (P banks and units with cryovolumes other than 24.5 to 26.0 mL were more likely to have poor postthaw viability. Precryopreservation CD34(+) cell dose and banking practices should be incorporated into CB unit selection.

  6. Fuel cell repeater unit including frame and separator plate

    Energy Technology Data Exchange (ETDEWEB)

    Yamanis, Jean; Hawkes, Justin R; Chiapetta, Jr., Louis; Bird, Connie E; Sun, Ellen Y; Croteau, Paul F

    2013-11-05

    An example fuel cell repeater includes a separator plate and a frame establishing at least a portion of a flow path that is operative to communicate fuel to or from at least one fuel cell held by the frame relative to the separator plate. The flow path has a perimeter and any fuel within the perimeter flow across the at least one fuel cell in a first direction. The separator plate, the frame, or both establish at least one conduit positioned outside the flow path perimeter. The conduit is outside of the flow path perimeter and is configured to direct flow in a second, different direction. The conduit is fluidly coupled with the flow path.

  7. Refractive index extraction and thickness optimization of Cu2ZnSnSe4 thin film solar cells

    NARCIS (Netherlands)

    ElAnzeery, H.; El Daif, O.; Buffière, M.; Oueslati, S.; Ben Messaoud, K.; Agten, D.; Brammertz, G.; Guindi, R.; Kniknie, B.; Meuris, M.; Poortmans, J.

    2015-01-01

    Cu2nSnSe4 (CZTSe) thin film solar cells are promising emergent photovoltaic technologies based on low-bandgap absorber layer with high absorption coefficient. To reduce optical losses in such devices and thus improve their efficiency, numerical simulations of CZTSe solar cells optical characteristic

  8. Evaluation of the pneumatic tube system for transportation of packed red cell units

    Directory of Open Access Journals (Sweden)

    Supriya Dhar

    2015-01-01

    Full Text Available Background: Pneumatic tube system (PTS is commonly used in hospital settings to transport blood samples to diagnostic laboratories. At our blood center, we receive blood requisitions via the PTS, but units are carried to the ward by human courier. Recently we considered using the PTS for transporting blood units. Since, there are reports of hemolysis in blood samples sent through the PTS, we evaluated this system for transporting red cell units. Aims: The aim was to assess the effect of PTS transport on the quality of packed red cell units. Materials and Methods: A total of 50 red blood cells units (RBC, (25 non-irradiated and 25 irradiated were subjected to transportation through the PTS. The control arm in the study was age-matched RBC units not subjected to PTS transport. Each RBC unit was evaluated for hemoglobin (Hb, lactate dehydrogenase, potassium and plasma hemoglobin (Hb. The paired t-test was used to compare these parameters, and the P value was calculated. Results and Conclusion: The percentage of hemolysis after transportation through PTS was below the recommended guidelines. Delivery of the blood unit to the wrong station, bags lying unattended at the destination were few of the problems that had to be addressed. To conclude, though the PTS is a safe means of transporting blood products with reduction in the turn-around-time, it must be validated before use.

  9. Control of an afterburner in a diesel fuel cell power unit under variable load

    Science.gov (United States)

    Dolanc, Gregor; Pregelj, Boštjan; Petrovčič, Janko; Samsun, Remzi Can

    2017-01-01

    In this paper, the control system for a catalytic afterburner in a diesel fuel cell auxiliary power unit is presented. The catalytic afterburner is used to burn the non-utilised hydrogen and other possible combustible components of the fuel cell anode off-gas. To increase the energy efficiency of the auxiliary power unit, the thermal energy released in the catalytic afterburner is utilised to generate the steam for the fuel processor. For optimal operation of the power unit in all modes of operation including load change, stable steam generation is required and overall energy balance must be kept within design range. To achieve this, the reaction temperature of the catalytic afterburner must be stable in all modes of operation. Therefore, we propose the afterburner temperature control based on mass and thermal balances. Finally, we demonstrate the control system using the existing prototype of the diesel fuel cell auxiliary power unit.

  10. Efficiency of the unit cell in rectangular finned tube arrangements

    Energy Technology Data Exchange (ETDEWEB)

    Buzzoni, Luca; Dall' Olio, Roberto; Spiga, Marco [Bologna Univ., DIENCA, Bologna (Italy)

    1999-11-01

    This paper is aimed at presenting an investigation concerning the efficiency of the single unit in finned air-cooled heat exchangers with staggered and in-line bundles of rectangular ducts, where a hot process fluid flows inside extended-surface tubes and atmospheric air is circulated outside, over the extended surface. The differential energy equation is numerically solved by a finite difference technique, in order to determine the spatial temperature profiles, then the fin efficiency and the augmentation factor are calculated by a simple numerical integration. The results show that the temperature distribution and the fin performance depend on four dimensionless parameters (m,{beta},p{sub x},p{sub y}), the first accounting for the heat transfer condition, the other ones accounting for the geometry of the extended surface (tube aspect ratio and pitches). Several tables are presented, allowing the efficiency of the extended surface to be deduced as a function of the thermal and geometric parameters. (Author)

  11. Thickness Effects in the Resonance of Metasurfaces made of SRRs ans C-SRRs

    CERN Document Server

    Pulido-Mancera, L M; Araque, J L

    2013-01-01

    Different periodical Frequency Selective Surfaces(FSS) whose unit cell are the Split Ring Resonators (SRR) or related geometries and their corresponding complementary screens were studied. This kind of FSS, sometimes called metasurfaces, have the advantage of avoiding secondary grating lobes because of the small electrical size of the unit cell. The main aim of this paper is to investigate the effects of the metal thickness for these FSSs. It was found that the quality factor decrease for unconnected elements (strips) and increase for connected elements (slots). Besides, as the thickness increases, the resonance frequency decrease for the case of unconnected elements while increases for connected elements.

  12. Quantification of Cell-Free DNA in Red Blood Cell Units in Different Whole Blood Processing Methods

    Directory of Open Access Journals (Sweden)

    Andrew W. Shih

    2016-01-01

    Full Text Available Background. Whole blood donations in Canada are processed by either the red cell filtration (RCF or whole blood filtration (WBF methods, where leukoreduction is potentially delayed in WBF. Fresh WBF red blood cells (RBCs have been associated with increased in-hospital mortality after transfusion. Cell-free DNA (cfDNA is released by neutrophils prior to leukoreduction, degraded during RBC storage, and is associated with adverse patient outcomes. We explored cfDNA levels in RBCs prepared by RCF and WBF and different storage durations. Methods. Equal numbers of fresh (stored ≤14 days and older RBCs were sampled. cfDNA was quantified by spectrophotometry and PicoGreen. Separate regression models determined the association with processing method and storage duration and their interaction on cfDNA. Results. cfDNA in 120 RBC units (73 RCF, 47 WBF were measured. Using PicoGreen, WBF units overall had higher cfDNA than RCF units (p=0.0010; fresh WBF units had higher cfDNA than fresh RCF units (p=0.0093. Using spectrophotometry, fresh RBC units overall had higher cfDNA than older units (p=0.0031; fresh WBF RBCs had higher cfDNA than older RCF RBCs (p=0.024. Conclusion. Higher cfDNA in fresh WBF was observed compared to older RCF blood. Further study is required for association with patient outcomes.

  13. In vivo thickness measurement of basal cell carcinoma and actinic keratosis with optical coherence tomography and 20-MHz ultrasound

    DEFF Research Database (Denmark)

    Mogensen, Mette; Nürnberg, B.M.; Forman, J.L.

    2009-01-01

    and 34 lesions [23 basal cell carcinoma (BCC) and 11 actinic keratosis (AK) lesions] biopsies. The influence of skin pigmentation and infiltration analgesia on OCT image quality was studied. Skin colour...

  14. Dynamic culture induces a cell type-dependent response impacting on the thickness of engineered connective tissues.

    Science.gov (United States)

    Fortier, Guillaume Marceau; Gauvin, Robert; Proulx, Maryse; Vallée, Maud; Fradette, Julie

    2013-04-01

    Mesenchymal cells are central to connective tissue homeostasis and are widely used for tissue-engineering applications. Dermal fibroblasts and adipose-derived stromal cells (ASCs) allow successful tissue reconstruction by the self-assembly approach of tissue engineering. This method leads to the production of multilayered tissues, devoid of exogenous biomaterials, that can be used as stromal compartments for skin or vesical reconstruction. These tissues are formed by combining cell sheets, generated through cell stimulation with ascorbic acid, which favours the cell-derived production/organization of matrix components. Since media motion can impact on cell behaviour, we investigated the effect of dynamic culture on mesenchymal cells during tissue reconstruction, using the self-assembly method. Tissues produced using ASCs in the presence of a wave-like movement were nearly twice thicker than under standard conditions, while no difference was observed for tissues produced from dermal fibroblasts. The increased matrix deposition was not correlated with an increased proliferation of ASCs, or by higher transcript levels of fibronectin or collagens I and III. A 30% increase of type V collagen mRNA was observed. Interestingly, tissues engineered from dermal fibroblasts featured a four-fold higher level of MMP-1 transcripts under dynamic conditions. Mechanical properties were similar for tissues reconstructed using dynamic or static conditions. Finally, cell sheets produced using ASCs under dynamic conditions could readily be manipulated, resulting in a 2 week reduction of the production time (from 5 to 3 weeks). Our results describe a distinctive property of ASCs' response to media motion, indicating that their culture under dynamic conditions leads to optimized tissue engineering.

  15. High performance internal reforming unit for high temperature fuel cells

    Science.gov (United States)

    Ma, Zhiwen; Venkataraman, Ramakrishnan; Novacco, Lawrence J.

    2008-10-07

    A fuel reformer having an enclosure with first and second opposing surfaces, a sidewall connecting the first and second opposing surfaces and an inlet port and an outlet port in the sidewall. A plate assembly supporting a catalyst and baffles are also disposed in the enclosure. A main baffle extends into the enclosure from a point of the sidewall between the inlet and outlet ports. The main baffle cooperates with the enclosure and the plate assembly to establish a path for the flow of fuel gas through the reformer from the inlet port to the outlet port. At least a first directing baffle extends in the enclosure from one of the sidewall and the main baffle and cooperates with the plate assembly and the enclosure to alter the gas flow path. Desired graded catalyst loading pattern has been defined for optimized thermal management for the internal reforming high temperature fuel cells so as to achieve high cell performance.

  16. The photovoltaic efficiency of the fabrication of copolymer P3HT:PCBM on different thickness nano-anatase titania as solar cell

    Science.gov (United States)

    Lazim, Haidar Gazy; Ajeel, Khalid I.; Badran, Hussain A.

    2015-06-01

    Organic solar cells based on (3-hexylthiophene):[6,6]-phenyl C61-butyric acid methylester (P3HT:PCBM) bulk heterojunction (BHJ) with an inverted structure have been fabricated using nano-anatase crystalline titanium dioxide (TiO2) as their electron transport layer, which was prepared on the indium tin oxide coated glass (ITO-glass), silicon wafer and glass substrates by sol-gel method at different spin speed by using spin-coating (1000, 2000 and 3000 rpm) for nano-thin film 58, 75 and 90 nm respectively. The effect of thickness on the surface morphology and optical properties of TiO2 layer were investigated by atomic force microscopy (AFM), X-ray diffraction and UV-visible spectrophotometer. The optical band gap of the films has been found to be in the range 3.63-3.96 eV for allowed direct transition and to be in the range 3.23-3.69 eV for forbidden direct transition to the different TiO2 thickness. The samples were examined to feature current and voltages darkness and light extraction efficiency of the solar cell where they were getting the highest open-circuit voltage, Voc, and power conversion efficiency were 0.66% and 0.39% fabricated with 90 nm respectively.

  17. Applying Infrared Thermography as a Quality-Control Tool for the Rapid Detection of Proton-Electrolyte-Membrane-Fuel-Cell Catalyst-Layer-Thickness Variations

    Energy Technology Data Exchange (ETDEWEB)

    Aieta, N. V.; Das, P. K.; Perdue, A.; Bender, G.; Herring, A. M.; Weber, A. Z.; Ulsh, M. J.

    2012-08-01

    As fuel cells become more prominent, new manufacturing and production methods are needed to enable increased volumes with high quality. One necessary component of this industrial growth will be the accurate measurement of the variability of a wide range of material properties during the manufacturing process. In this study, a method to detect defects in fuel cell catalyst layers is investigated through experiment and mathematical simulation. The method uses infrared thermography and direct-current electronic-excitation methods to detect variations in platinum-containing catalyst-layer thickness with high spatial and temporal resolution. Data analysis, operating-condition impacts, and detection limits are explored, showing the measurement of defects on the millimeter length scale. Overall, the experimental and modeling results demonstrate great potential of this technique as a nondestructive method to measure defects that is amenable to use on roll-to-roll manufacturing lines.

  18. The Daniell cell, Ohm's law, and the emergence of the International System of Units

    Science.gov (United States)

    Jayson, Joel S.

    2014-01-01

    Telegraphy originated in the 1830s and 40 s and flourished in the following decades but with a patchwork of electrical standards. Electromotive force was for the most part measured in units of the predominant Daniell cell, but each telegraphy company had their own resistance standard. In 1862, the British Association for the Advancement of Science formed a committee to address this situation. By 1873, they had given definition to the electromagnetic system of units (emu) and defined the practical units of the ohm as 109 emu units of resistance and the volt as 108 emu units of electromotive force. These recommendations were ratified and expanded upon in a series of international congresses held between 1881 and 1904. A proposal by Giovanni Giorgi in 1901 took advantage of a coincidence between the conversion of the units of energy in the emu system (the erg) and in the practical system (the Joule). As it was, the same conversion factor existed between the cgs based emu system and a theretofore undefined MKS system. By introducing another unit X (where X could be any of the practical electrical units), Giorgi demonstrated that a self-consistent MKSX system was tenable without the need for multiplying factors. Ultimately, the ampere was selected as the fourth unit. It took nearly 60 years, but in 1960, Giorgi's proposal was incorporated as the core of the newly inaugurated International System of Units (SI). This article surveys the physics, physicists, and events that contributed to those developments.

  19. 4D super-resolution microscopy with conventional fluorophores and single wavelength excitation in optically thick cells and tissues.

    Directory of Open Access Journals (Sweden)

    David Baddeley

    Full Text Available BACKGROUND: Optical super-resolution imaging of fluorescently stained biological samples is rapidly becoming an important tool to investigate protein distribution at the molecular scale. It is therefore important to develop practical super-resolution methods that allow capturing the full three-dimensional nature of biological systems and also can visualize multiple protein species in the same sample. METHODOLOGY/PRINCIPAL FINDINGS: We show that the use of a combination of conventional near-infrared dyes, such as Alexa 647, Alexa 680 and Alexa 750, all excited with a 671 nm diode laser, enables 3D multi-colour super-resolution imaging of complex biological samples. Optically thick samples, including human tissue sections, cardiac rat myocytes and densely grown neuronal cultures were imaged with lateral resolutions of ∼15 nm (std. dev. while reducing marker cross-talk to <1%. Using astigmatism an axial resolution of ∼65 nm (std. dev. was routinely achieved. The number of marker species that can be distinguished depends on the mean photon number of single molecule events. With the typical photon yields from Alexa 680 of ∼2000 up to 5 markers may in principle be resolved with <2% crosstalk. CONCLUSIONS/SIGNIFICANCE: Our approach is based entirely on the use of conventional, commercially available markers and requires only a single laser. It provides a very straightforward way to investigate biological samples at the nanometre scale and should help establish practical 4D super-resolution microscopy as a routine research tool in many laboratories.

  20. Nano-crystalline thin and nano-particulate thick TiO{sub 2} layer: Cost effective sequential deposition and study on dye sensitized solar cell characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Das, P.; Sengupta, D. [Centre for Advanced Materials Processing, CSIR-Central Mechanical Engineering Research Institute, Durgapur, 713209 West Bengal (India); CSIR-Central Mechanical Engineering Research Institute, Academy of Scientific and Innovative Research (AcSIR), Durgapur, 713209 West Bengal (India); Kasinadhuni, U. [Department of Engineering Physics, Bengal College of Engineering and Technology, Durgapur, West Bengal (India); Mondal, B. [Centre for Advanced Materials Processing, CSIR-Central Mechanical Engineering Research Institute, Durgapur, 713209 West Bengal (India); Mukherjee, K., E-mail: kalisadhanm@yahoo.com [Centre for Advanced Materials Processing, CSIR-Central Mechanical Engineering Research Institute, Durgapur, 713209 West Bengal (India)

    2015-06-15

    Highlights: • Thin TiO{sub 2} layer is deposited on conducting substrate using sol–gel based dip coating. • TiO{sub 2} nano-particles are synthesized using hydrothermal route. • Thick TiO{sub 2} particulate layer is deposited on prepared thin layer. • Dye sensitized solar cells are made using thin and thick layer based photo-anode. • Introduction of thin layer in particulate photo-anode improves the cell efficiency. - Abstract: A compact thin TiO{sub 2} passivation layer is introduced between the mesoporous TiO{sub 2} nano-particulate layer and the conducting glass substrate to prepare photo-anode for dye-sensitized solar cell (DSSC). In order to understand the effect of passivation layer, other two DSSCs are also developed separately using TiO{sub 2} nano-particulate and compact thin film based photo-anodes. Nano-particles are prepared using hydrothermal synthesis route and the compact passivation layer is prepared by simply dip coating the precursor sol prepared through wet chemical route. The TiO{sub 2} compact layer and the nano-particles are characterised in terms of their micro-structural features and phase formation behavior. It is found that introduction of a compact TiO{sub 2} layer in between the mesoporous TiO{sub 2} nano-particulate layer and the conducting substrate improves the solar to electric conversion efficiency of the fabricated cell. The dense thin passivation layer is supposed to enhance the photo-excited electron transfer and prevent the recombination of photo-excited electrons.

  1. Inheritance of the number and thickness of cell layers in barley aleurone tissue (Hordeum vulgare L.): an approach using F2-F3 progeny.

    Science.gov (United States)

    Jestin, Louis; Ravel, Catherine; Auroy, Sylvie; Laubin, Bastien; Perretant, Marie-Reine; Pont, Caroline; Charmet, Gilles

    2008-05-01

    The aleurone tissue of cereal grains, nutritionally rich in minerals and vitamins, is an important target for the improvement of cereals. Inheritance of the thickness and the number of cell layers in barley aleurone was studied on the F2-F3 progeny of an Erhard Frederichen x Criolla Negra cross in which the parental lines have three or two aleurone layers, respectively. F3 grain was sampled from each F2 plant and 96.8% of the entire F3 grain population was classified as being either the 2- or 3-layer type. Using microsatellite, single nucleotide polymorphism (SNP) and morphological markers on 190 F2 plants, a linkage map was built. Three quantitative trait loci (QTLs) affecting aleurone traits were revealed on chromosome 5H (max. LOD = 5.83) and chromosome 7H (max. LOD = 4.45) by interval mapping, and on chromosome 2H by marker analysis with an unmapped marker. These QTLs were consistent with genetic sub-models involving either 2-cell type dominance for 7H and 2H, or putative partial dominance for 5H where 2-cell-layer dominance and additivity gave similar LODs. The number of aleurone cell layers and aleurone thickness were strongly correlated and QTL results for these traits were alike. An SNP marker of sal1, an orthologue of the maize multilayer aleurone gene was mapped to the 7HL chromosome arm. However, the 7H QTL did not co-locate with the barley sal1 SNP, suggesting that an additional gene is involved in determining aleurone traits. These new mapping data allow comparisons to be made with related studies.

  2. Numerical Analysis of In2S3 Layer Thickness, Band Gap and Doping Density for Effective Performance of a CIGS Solar Cell Using SCAPS

    Science.gov (United States)

    Khoshsirat, Nima; Md Yunus, Nurul Amziah

    2016-11-01

    The effect of indium sulfide buffer layer's geometrical and electro-optical properties on the Copper-Indium-Gallium-diSelenide solar cell performance using numerical simulation is investigated. The numerical simulation software used is a solar cell capacitance simulator in (SCAPS). The innermost impacts of buffer layer thickness, band gap, and doping density on the cells output parameters such as open circuit voltage, short circuit current density, fill factor, and the efficiency were extensively simulated. The results show that the cell efficiency, which was innovatively illustrated as a two-dimensional contour plot function, depends on the buffer layer electron affinity and doping density by keeping all the other parameters at a steady state. The analysis, which was made from this numerical simulation, has revealed that the optimum electron affinity is to be 4.25 ± 0.2 eV and donor density of the buffer layer is over 1× 10 ^{17} cm^{-3}. It is also shown that the cell with an optimum thin buffer layer has higher performance and efficiency due to the lower optical absorption of the buffer layer.

  3. Optimization of High-Efficiency CdS/CdTe Thin Film Solar Cell Using Step Doping Grading and Thickness of the Absorption Layer

    Directory of Open Access Journals (Sweden)

    Masoud Sabaghi

    2015-06-01

    Full Text Available In this paper, the influence of stepped doping of the absorber layer on performance of Cadmium Sulfide/Cadmium Telluride (CdS/CdTe solar cell has been investigated. At first, the electrical characteristics of conventional CdS/CdTe solar cell is validated with fabricated CdS/CdTe solar cell. To improve the maximum efficiency of CdS/CdTe solar cell, the doping and thickness of the absorption layer are optimized. By step doping concentration within the absorber layer using buffer layer back contact and the increase in stepping gradient of the doping of CdTe layer, improved the conversion efficiency about 2.4% were obtained. The open-circuit voltage, short-circuit current density, fill factor and total area conversion efficiency of optimized solar cell structure are 952 mV, 25.97 mA/cm2, 78.5% and 18.7% under global AM 1.5 conditions, respectively.

  4. Realization of 13.6% Efficiency on 20 μm Thick Si/Organic Hybrid Heterojunction Solar Cells via Advanced Nanotexturing and Surface Recombination Suppression.

    Science.gov (United States)

    He, Jian; Gao, Pingqi; Liao, Mingdun; Yang, Xi; Ying, Zhiqin; Zhou, Suqiong; Ye, Jichun; Cui, Yi

    2015-06-23

    Hybrid silicon/polymer solar cells promise to be an economically feasible alternative energy solution for various applications if ultrathin flexible crystalline silicon (c-Si) substrates are used. However, utilization of ultrathin c-Si encounters problems in light harvesting and electronic losses at surfaces, which severely degrade the performance of solar cells. Here, we developed a metal-assisted chemical etching method to deliver front-side surface texturing of hierarchically bowl-like nanopores on 20 μm c-Si, enabling an omnidirectional light harvesting over the entire solar spectrum as well as an enlarged contact area with the polymer. In addition, a back surface field was introduced on the back side of the thin c-Si to minimize the series resistance losses as well as to suppress the surface recombination by the built high-low junction. Through these improvements, a power conversion efficiency (PCE) up to 13.6% was achieved under an air mass 1.5 G irradiation for silicon/organic hybrid solar cells with the c-Si thickness of only about 20 μm. This PCE is as high as the record currently reported in hybrid solar cells constructed from bulk c-Si, suggesting a design rule for efficient silicon/organic solar cells with thinner absorbers.

  5. [THE MODEL OF NEUROVASCULAR UNIT IN VITRO CONSISTING OF THREE CELLS TYPES].

    Science.gov (United States)

    Khilazheva, E D; Boytsova, E B; Pozhilenkova, E A; Solonchuk, Yu R; Salmina, A B

    2015-01-01

    There are many ways to model blood brain barrier and neurovascular unit in vitro. All existing models have their disadvantages, advantages and some peculiarities of preparation and usage. We obtained the three-cells neurovascular unit model in vitro using progenitor cells isolated from the rat embryos brain (Wistar, 14-16 d). After withdrawal of the progenitor cells the neurospheres were cultured with subsequent differentiation into astrocytes and neurons. Endothelial cells were isolated from embryonic brain too. During the differentiation of progenitor cells the astrocytes monolayer formation occurs after 7-9 d, neurons monolayer--after 10-14 d, endothelial cells monolayer--after 7 d. Our protocol for simultaneous isolation and cultivation of neurons, astrocytes and endothelial cells reduces the time needed to obtain neurovascular unit model in vitro, consisting of three cells types and reduce the number of animals used. It is also important to note the cerebral origin of all cell types, which is also an advantage of our model in vitro.

  6. Importance of unit cells in accurate evaluation of the characteristics of graphene

    Energy Technology Data Exchange (ETDEWEB)

    Sabzyan, Hassan; Sadeghpour, Narges [Isfahan Univ. (Iran, Islamic Republic of). Dept. of Chemistry

    2016-08-01

    Effects of the size of the unit cell on energy, atomic charges, and phonon frequencies of graphene at the Γ point of the Brillouin zone are studied in the absence and presence of an electric field using density functional theory (DFT) methods (LDA and DFT-PBE functionals with Goedecker-Teter-Hutter (GTH) and Troullier-Martins (TM) norm-conserving pseudopotentials). Two types of unit cells containing n{sub c}=4-28 carbon atoms are considered. Results show that stability of graphene increases with increasing size of the unit cell. Energy, atomic charges, and phonon frequencies all converge above n{sub c}=24 for all functional-pseudopotentials used. Except for the LDA-GTH calculations, application of an electric field of 0.4 and 0.9 V/nm strengths does not change the trends with the size of the unit cell but instead slightly decreases the binding energy of graphene. Results of this study show that the choice of unit cell size and type is critical for calculation of reliable characteristics of graphene.

  7. Comparative Diagnostic Accuracy of Ganglion Cell-Inner Plexiform and Retinal Nerve Fiber Layer Thickness Measures by Cirrus and Spectralis Optical Coherence Tomography in Relapsing-Remitting Multiple Sclerosis

    Directory of Open Access Journals (Sweden)

    Julio J. González-López

    2014-01-01

    Full Text Available Objective. To estimate sensitivity and specificity of several optical coherence tomography (OCT measurements for detecting retinal thickness changes in patients with relapsing-remitting multiple sclerosis (RRMS, such as macular ganglion cell-inner plexiform layer (GCIPL thickness measured with Cirrus (OCT and peripapillary retinal nerve fiber layer (pRNFL thickness measured with Cirrus and Spectralis OCT. Methods. Seventy patients (140 eyes with RRMS and seventy matched healthy subjects underwent pRNFL and GCIPL thickness analysis using Cirrus OCT and pRNFL using Spectralis OCT. A prospective, cross-sectional evaluation of sensitivities and specificities was performed using latent class analysis due to the absence of a gold standard. Results. GCIPL measures had higher sensitivity and specificity than temporal pRNFL measures obtained with both OCT devices. Average GCIPL thickness was significantly more sensitive than temporal pRNFL by Cirrus (96.34% versus 58.41% and minimum GCIPL thickness was significantly more sensitive than temporal pRNFL by Spectralis (96.41% versus 69.69%. Generalised estimating equation analysis revealed that age (P=0.030, optic neuritis antecedent (P=0.001, and disease duration (P=0.002 were significantly associated with abnormal results in average GCIPL thickness. Conclusion. Average and minimum GCIPL measurements had significantly better sensitivity to detect retinal thickness changes in RRMS than temporal pRNFL thickness measured by Cirrus and Spectralis OCT, respectively.

  8. New photosensitizer with phenylenebisthiophene central unit and cyanovinylene 4-nitrophenyl terminal units for dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Mikroyannidis, J.A., E-mail: mikroyan@chemistry.upatras.gr [Chemical Technology Laboratory, Department of Chemistry, University of Patras, GR-26500 Patras (Greece); Suresh, P. [Physics Department, Molecular Electronic and Optoelectronic Device Laboratory, JNV University, Jodhpur (Raj.) 342005 (India); Roy, M.S. [Defence Laboratory, Jodhpur (Raj.) 342011 (India); Sharma, G.D., E-mail: sharmagd_in@yahoo.com [Physics Department, Molecular Electronic and Optoelectronic Device Laboratory, JNV University, Jodhpur (Raj.) 342005 (India); R and D Centre for Engineering and Science, Jaipur Engineering College, Kukas, Jaipur (Raj.) (India)

    2011-06-30

    Graphical abstract: A novel dye D was synthesized and used as photosensitizer for quasi solid state dye-sensitized solar cells. A power conversion efficiency of 4.4% was obtained which was improved to 5.52% when diphenylphosphinic acid (DPPA) was added as coadsorbent. Display Omitted Highlights: > A new low band gap photosensitizer with cyanovinylene 4-nitrophenyl terminal units was synthesized. > A power conversion efficiency of 4.4% was obtained for the dye-sensitized solar cell based on this photosensitizer. > The power conversion efficiency of the dye-sensitized solar cell was further improved to 5.52% when diphenylphosphinic acid was added as coadsorbent. - Abstract: A new low band gap photosensitizer, D, which contains 2,2'-(1,4-phenylene) bisthiophene central unit and cyanovinylene 4-nitrophenyl terminal units at both sides was synthesized. The two carboxyls attached to the 2,5-positions of the phenylene ring act as anchoring groups. Dye D was soluble in common organic solvents, showed long-wavelength absorption maximum at 620-636 nm and optical band gap of 1.72 eV. The electrochemical parameters, i.e. the highest occupied molecular orbital (HOMO) (-5.1 eV) and the lowest unoccupied molecular orbital (LUMO) (-3.3 eV) energy levels of D show that this dye is suitable as molecular sensitizer. The quasi solid state dye-sensitized solar cell (DSSC) based on D shows a short circuit current (J{sub sc}) of 9.95 mA/cm{sup 2}, an open circuit voltage (V{sub oc}) of 0.70 V, and a fill factor (FF) of 0.64 corresponding to an overall power conversion efficiency (PCE) of 4.40% under 100 mW/cm{sup 2} irradiation. The overall PCE has been further improved to 5.52% when diphenylphosphinic acid (DPPA) coadsorbent is incorporated into the D solution. This increased PCE has been attributed to the enhancement in the electron lifetime and reduced recombination of injected electrons with the iodide ions present in the electrolyte with the use of DPPA as coadsorbant. The

  9. In vivo evaluation of chitosan-glycerol gel scaffolds seeded with stem cells for full-thickness mandibular bone regeneration.

    Science.gov (United States)

    Maglione, Michele; Spano, Serena; Ruaro, Maria E; Salvador, Enrico; Zanconati, Fabrizio; Tromba, Giuliana; Turco, Gianluca

    2017-01-01

    The aim of this study was to evaluate in vivo bone regeneration, mediated by adipose-derived stem cells (ADSCs), induced to differentiate into osteoblasts and carried by a scaffold gel. In the test group, bone regeneration was mediated by ADSCs, induced to differentiate into osteoblasts, and carried by a scaffold gel. In the control group a scaffold without cells was used. The scaffold, consisting of chitosan and glycerol phosphate, was maintained in situ by a cross-linked resorbable membrane. The osteogenic potential of ADSCs was confirmed by osteocalcin assay and Von Kossa staining performed before implantation. Histological assays detected an initial increase in bone formation in the test group compared with the control group. Microcomputed tomography analysis did not show significant differences between the two groups. Both histological and microcomputed tomography analysis were performed on the ex vivo specimens after a follow-up period of 8 weeks. We observed that differentiated ADSCs could increase bone regeneration and that the scaffold used here can be a suitable carrier to entrap and maintain the cells in situ. On the contrary, the membrane used was not functional in isolating the site of the defect from surrounding soft tissues and caused a significant inflammatory reaction.

  10. Optical approaches to improve the photocurrent generation in Cu(In,Ga)Se2 solar cells with absorber thicknesses down to 0.5 μm

    Science.gov (United States)

    Dahan, N.; Jehl, Z.; Hildebrandt, T.; Greffet, J.-J.; Guillemoles, J.-F.; Lincot, D.; Naghavi, N.

    2012-11-01

    Improving the optical management is a key issue for ultrathin based solar cells performance. It can be accomplished either by trapping the light in the active layer or by decreasing the parasitic absorptions in the cell. We calculate the absorption of the different layers of Cu(In,Ga)Se2 (CIGSe) based solar cell and propose to increase the absorption in the CIGSe layer by optimizing three parameters. First, by increasing the transmitted light to the cell using a textured surface of ZnO:Al front contact which functions as a broadband antireflection layer. Second, by replacing the CdS/i-ZnO buffer layers with ZnS/ZnMgO buffer layers which have higher energy bandgaps. Third, by replacing the Mo back contact with a higher reflective metal, such as silver or gold. Calculations show that modifying these layers improves the total absorption by 32% in a 0.5 μm thick CIGSe absorber. These predicted improvements of the short circuit current are confirmed experimentally.

  11. Prediction of stress-strain behavior of ceramic matrix composites using unit cell model

    Directory of Open Access Journals (Sweden)

    Suzuki Takuya

    2015-01-01

    Full Text Available In this study, the elastic modulus and the stress-strain curve of ceramic matrix composites (CMCs were predicted by using the unit cell model that consists of fiber bundles and matrix. The unit cell model was developed based on the observation of cross sections of CMCs. The elastic modulus of CMCs was calculated from the results of finite element analysis using the developed model. The non-linear behavior of stress-strain curve of CMCs was also predicted by taking the degradation of the elastic modulus into consideration, where the degradation was related to the experimentally measured crack density in CMCs. The approach using the unit cell model was applied to two kinds of CMCs, and good agreement was obtained between the experimental and the calculated results.

  12. Reduction in potassium concentration of stored red blood cell units using a resin filter.

    Science.gov (United States)

    Yamada, Chisa; Heitmiller, Eugenie S; Ness, Paul M; King, Karen E

    2010-09-01

    Hyperkalemia is a serious complication of rapid and massive blood transfusion due to high plasma potassium (K) in stored red blood cell (RBC) units. A potassium adsorption filter (PAF) was developed in Japan to remove K by exchanging with sodium (Na). We performed an in vitro evaluation of its efficacy and feasibility of use. Three AS-3 RBC units were filtered by each PAF using gravity; 10 PAFs were tested. Blood group, age, flow rate, and irradiation status were recorded. Total volume, K, Na, Cl, Mg, total Ca (tCa), RBC count, hemoglobin (Hb), hematocrit (Hct), and plasma Hb were measured before and after filtering each unit. Ionized Ca (iCa), pH, and glucose were measured for some units. After filtration, the mean decrease in K was 97.5% in the first RBC unit, 91.2% in the second unit, and 64.4% in the third unit. The mean increases in Na, Mg, and tCa were 33.0, 151.4, and 116.1%, respectively. iCa and pH remained low; glucose was unchanged. RBC count, Hb, and Hct decreased slightly after filtration of first units; plasma Hb was unchanged. After filtration, there was no visual evidence of increased hemolysis or clot formation. The PAF decreased K concentration in stored AS-3 RBC units to minimal levels in the first and second RBC units. Optimally, one filter could be used for 2 RBC units. Although Na increased, the level may not be clinically significant. PAF may be useful for at-risk patients receiving older units or blood that has been stored after gamma irradiation. © 2010 American Association of Blood Banks.

  13. Hair Follicle Morphogenesis in the Treatment of Mouse Full-Thickness Skin Defects Using Composite Human Acellular Amniotic Membrane and Adipose Derived Mesenchymal Stem Cells

    Directory of Open Access Journals (Sweden)

    Wu Minjuan

    2016-01-01

    Full Text Available Early repair of skin injury and maximal restoration of the function and appearance have become important targets of clinical treatment. In the present study, we observed the healing process of skin defects in nude mice and structural characteristics of the new skin after transplantation of isolated and cultured adipose derived mesenchymal stem cells (ADMSCs onto the human acellular amniotic membrane (AAM. The result showed that ADMSCs were closely attached to the surface of AAM and grew well 24 h after seeding. Comparison of the wound healing rate at days 7, 14, and 28 after transplantation showed that ADMSCs seeded on AAM facilitated the healing of full-thickness skin wounds more effectively as compared with either hAM or AAM alone, indicating that ADMSCs participated in skin regeneration. More importantly, we noticed a phenomenon of hair follicle development during the process of skin repair. Composite ADMSCs and AAM not only promoted the healing of the mouse full-thickness defects but also facilitated generation of the appendages of the affected skin, thus promoting restoration of the skin function. Our results provide a new possible therapy idea for the treatment of skin wounds with respect to both anatomical regeneration and functional restoration.

  14. Hair Follicle Morphogenesis in the Treatment of Mouse Full-Thickness Skin Defects Using Composite Human Acellular Amniotic Membrane and Adipose Derived Mesenchymal Stem Cells

    Science.gov (United States)

    Minjuan, Wu; Jun, Xiong; Shiyun, Shao; Sha, Xu; Haitao, Ni

    2016-01-01

    Early repair of skin injury and maximal restoration of the function and appearance have become important targets of clinical treatment. In the present study, we observed the healing process of skin defects in nude mice and structural characteristics of the new skin after transplantation of isolated and cultured adipose derived mesenchymal stem cells (ADMSCs) onto the human acellular amniotic membrane (AAM). The result showed that ADMSCs were closely attached to the surface of AAM and grew well 24 h after seeding. Comparison of the wound healing rate at days 7, 14, and 28 after transplantation showed that ADMSCs seeded on AAM facilitated the healing of full-thickness skin wounds more effectively as compared with either hAM or AAM alone, indicating that ADMSCs participated in skin regeneration. More importantly, we noticed a phenomenon of hair follicle development during the process of skin repair. Composite ADMSCs and AAM not only promoted the healing of the mouse full-thickness defects but also facilitated generation of the appendages of the affected skin, thus promoting restoration of the skin function. Our results provide a new possible therapy idea for the treatment of skin wounds with respect to both anatomical regeneration and functional restoration. PMID:27597871

  15. High light-extraction-efficiency OLED based on photonic crystal slab structures with taper unit cells

    Institute of Scientific and Technical Information of China (English)

    YAN Rong-jin; WANG Qing-kang

    2006-01-01

    To improve the light-extraction-efficiency of OLED,we introduced PCS (Photonic Crystal Slab) structures into the interface of ITO layer and glass substrate.PCS structures with Taper unit cells are proved to be effective in reducing the energy of guided wave trapped in high refractive index material,and an increase of light-extraction-efficiency to 95.26% is gained.This enhancement is much greater than the traditional PCS with cylinder unit cells (60%-70%).Physical mechanisms of light-extraction-efficiency enhancement in these structures are further discussed.

  16. Specific cell-derived microvesicles: Linking endothelial function to carotid artery intima-media thickness in low cardiovascular risk menopausal women.

    Science.gov (United States)

    Miller, Virginia M; Lahr, Brian D; Bailey, Kent R; Hodis, Howard N; Mulvagh, Sharon L; Jayachandran, Muthuvel

    2016-03-01

    Decreases in endothelial function measured by reactive hyperemic index (RHI) correlated with increases in carotid intima-media thickness (CIMT) in recently menopausal women with a low risk cardiovascular profile. Factors linking this association are unknown. Assess, longitudinally, markers of platelet activation and cell-derived, blood-borne microvesicles (MV) in relationship to RHI and CIMT in asymptomatic, low risk menopausal women. RHI by digital pulse tonometry (n = 93), CIMT by ultrasound (n = 113), measures of platelet activation and specific cell-derived, blood-borne MV were evaluated in women throughout the Kronos Early Estrogen Prevention Study (KEEPS) at Mayo Clinic. CIMT, but not RHI, increased significantly over 4 years. The average change in CIMT correlated significantly with the average follow-up values of MV positive for common leukocyte antigen [CD45; ρ = 0.285 (P = 0.002)] and VCAM-1 [ρ = 0.270 (P = 0.0040)]. Using principal components analysis (PC) on the aggregate set of average follow-up measures, the first derived PC representing numbers of MV positive for markers of vascular endothelium, inflammatory cells (leukocyte and monocytes), pro-coagulant (tissue factor), and cell adhesion molecules (ICAM-1 and VCAM-1) associated with changes in RHI and CIMT. Changes in RHI associated with another PC defined by measures of platelet activation (dense granular ATP secretion, surface expression of P-selectin and fibrinogen receptors). MV derived from activated endothelial and inflammatory cells, and those expressing cell adhesion and pro-coagulant molecules may reflect early vascular dysfunction in low risk menopausal women. Assays of MV as non-conventional measures to assess cardiovascular risk in asymptomatic women remain to be developed. Copyright © 2015 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

  17. Investigation of IrO2/Pt Electrocatalysts in Unitized Regenerative Fuel Cells

    Directory of Open Access Journals (Sweden)

    V. Baglio

    2011-01-01

    Full Text Available IrO2/Pt catalysts (at different concentrations were synthesized by incipient wetness technique and characterized by XRD, XRF, and SEM. Water electrolysis/fuel cell performances were evaluated in a 5 cm2 single cell under Unitized Regenerative Fuel Cell (URFC configuration. The IrO2/Pt composition of 14/86 showed the highest performance for water electrolysis and the lowest one as fuel cell. It is derived that for fuel cell operation an excess of Pt favours the oxygen reduction process whereas IrO2 promotes oxygen evolution. From the present results, it appears that the diffusion characteristics and the reaction rate in fuel cell mode are significantly lower than in the electrolyser mode. This requires the enhancement of the gas diffusion properties of the electrodes and the catalytic properties for cathode operation in fuel cells.

  18. Local Circuits of V1 Layer 4B Neurons Projecting to V2 Thick Stripes Define Distinct Cell Classes and Avoid Cytochrome Oxidase Blobs.

    Science.gov (United States)

    Yarch, Jeff; Federer, Frederick; Angelucci, Alessandra

    2017-01-11

    Decades of anatomical studies on the primate primary visual cortex (V1) have led to a detailed diagram of V1 intrinsic circuitry, but this diagram lacks information about the output targets of V1 cells. Understanding how V1 local processing relates to downstream processing requires identification of neuronal populations defined by their output targets. In primates, V1 layers (L)2/3 and 4B send segregated projections to distinct cytochrome oxidase (CO) stripes in area V2: neurons in CO blob columns project to thin stripes while neurons outside blob columns project to thick and pale stripes, suggesting functional specialization of V1-to-V2 CO streams. However, the conventional diagram of V1 shows all L4B neurons, regardless of their soma location in blob or interblob columns, as projecting selectively to CO blobs in L2/3, suggesting convergence of blob/interblob information in L2/3 blobs and, possibly, some V2 stripes. However, it is unclear whether all L4B projection neurons show similar local circuitries. Using viral-mediated circuit tracing, we have identified the local circuits of L4B neurons projecting to V2 thick stripes in macaque. Consistent with previous studies, we found the somata of this L4B subpopulation to reside predominantly outside blob columns; however, unlike previous descriptions of local L4B circuits, these cells consistently projected outside CO blob columns in all layers. Thus, the local circuits of these L4B output neurons, just like their extrinsic projections to V2, preserve CO streams. Moreover, the intra-V1 laminar patterns of axonal projections identify two distinct neuron classes within this L4B subpopulation, including a rare novel neuron type, suggestive of two functionally specialized output channels.

  19. Saturated thickness, High Plains aquifer, 2009

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This raster data set represents the saturated thickness of the High Plains aquifer of the United States, 2009, in feet. The High Plains aquifer underlies...

  20. Water proton configurations in structures I, II, and H clathrate hydrate unit cells.

    Science.gov (United States)

    Takeuchi, Fumihito; Hiratsuka, Masaki; Ohmura, Ryo; Alavi, Saman; Sum, Amadeu K; Yasuoka, Kenji

    2013-03-28

    Position and orientation of water protons need to be specified when the molecular simulation studies are performed for clathrate hydrates. Positions of oxygen atoms in water are experimentally determined by X-ray diffraction analysis of clathrate hydrate structures, but positions of water hydrogen atoms in the lattice are disordered. This study reports a determination of the water proton coordinates in unit cell of structure I (sI), II (sII), and H (sH) clathrate hydrates that satisfy the ice rules, have the lowest potential energy configuration for the protons, and give a net zero dipole moment. Possible proton coordinates in the unit cell were chosen by analyzing the symmetry of protons on the hexagonal or pentagonal faces in the hydrate cages and generating all possible proton distributions which satisfy the ice rules. We found that in the sI and sII unit cells, proton distributions with small net dipole moments have fairly narrow potential energy spreads of about 1 kJ∕mol. The total Coulomb potential on a test unit charge placed in the cage center for the minimum energy∕minimum dipole unit cell configurations was calculated. In the sI small cages, the Coulomb potential energy spread in each class of cage is less than 0.1 kJ∕mol, while the potential energy spread increases to values up to 6 kJ∕mol in sH and 15 kJ∕mol in the sII cages. The guest environments inside the cages can therefore be substantially different in the sII case. Cartesian coordinates for oxygen and hydrogen atoms in the sI, sII, and sH unit cells are reported for reference.

  1. Development of a combined radiation and full thickness burn injury minipig model to study the effects of uncultured adipose-derived regenerative cell therapy in wound healing.

    Science.gov (United States)

    Foubert, Philippe; Doyle-Eisele, Melanie; Gonzalez, Andreina; Berard, Felipe; Weber, Waylon; Zafra, Diana; Alfonso, Zeni; Zhao, Sherry; Tenenhaus, Mayer; Fraser, John K

    2017-03-01

    To develop an approach that models the cutaneous healing that occurs in a patient with full thickness thermal burn injury complicated by total body radiation exposure sufficient to induce sub-lethal prodromal symptoms. An assessment of the effects of an autologous cell therapy on wound healing on thermal burn injury with concomitant radiation exposure was used to validate the utility of the model. Göttingen minipigs were subjected to a 1.2 Gy total body irradiation by exposure to a 6 MV X-ray linear accelerator followed by ∼10 cm(2) full thickness burns (pre-heated brass block with calibrated spring). Three days after injury, wounds were excised to the underlying fascia and each animal was randomized to receive treatment with autologous adipose-derived regenerative cells (ADRC) delivered by local or intravenous injection, or vehicle control. Blood counts were used to assess radiation-induced marrow suppression. All animals were followed using digital imaging to assess wound healing. Full-thickness biopsies were obtained at 7, 14, 21 and 30 days' post-treatment. Compared to animals receiving burn injury alone, significant transient neutropenia and thrombocytopenia were observed in irradiated subjects with average neutrophil nadir of 0.79 × 10(3)/μl (day 15) and platelet nadir of 60 × 10(3)/μl (day 12). Wound closure through a combination of contraction and epithelialization from the wound edges occurred over a period of approximately 28 days' post excision and treatment. Re-epithelialization was accelerated in wounds treated with ADRC (mean 3.5-fold increase at 2 weeks post-treatment relative to control). This acceleration was accompanied by an average 67% increase in blood vessel density and 30% increase in matrix (collagen) deposition. Similar results were observed when ADRC were injected either directly into the wound or by intravenous administration. Although preliminary, this study provides a reproducible minipig model of thermal burn

  2. Hybrid pn-junction solar cells based on layers of inorganic nanocrystals and organic semiconductors: optimization of layer thickness by considering the width of the depletion region.

    Science.gov (United States)

    Saha, Sudip K; Guchhait, Asim; Pal, Amlan J

    2014-03-07

    We report the formation and characterization of hybrid pn-junction solar cells based on a layer of copper diffused silver indium disulfide (AgInS2@Cu) nanoparticles and another layer of copper phthalocyanine (CuPc) molecules. With copper diffusion in the nanocrystals, their optical absorption and hence the activity of the hybrid pn-junction solar cells was extended towards the near-IR region. To decrease the particle-to-particle separation for improved carrier transport through the inorganic layer, we replaced the long-chain ligands of copper-diffused nanocrystals in each monolayer with short-ones. Under illumination, the hybrid pn-junctions yielded a higher short-circuit current as compared to the combined contribution of the Schottky junctions based on the components. A wider depletion region at the interface between the two active layers in the pn-junction device as compared to that of the Schottky junctions has been considered to analyze the results. Capacitance-voltage characteristics under a dark condition supported such a hypothesis. We also determined the width of the depletion region in the two layers separately so that a pn-junction could be formed with a tailored thickness of the two materials. Such a "fully-depleted" device resulted in an improved photovoltaic performance, primarily due to lessening of the internal resistance of the hybrid pn-junction solar cells.

  3. Culture of human cells in experimental units for spaceflight impacts on their behavior.

    Science.gov (United States)

    Cazzaniga, Alessandra; Moscheni, Claudia; Maier, Jeanette Am; Castiglioni, Sara

    2017-05-01

    Because space missions produce pathophysiological alterations such as cardiovascular disorders and bone demineralization which are very common on Earth, biomedical research in space is a frontier that holds important promises not only to counterbalance space-associated disorders in astronauts but also to ameliorate the health of Earth-bound population. Experiments in space are complex to design. Cells must be cultured in closed cell culture systems (from now defined experimental units (EUs)), which are biocompatible, functional, safe to minimize any potential hazard to the crew, and with a high degree of automation. Therefore, to perform experiments in orbit, it is relevant to know how closely culture in the EUs reflects cellular behavior under normal growth conditions. We compared the performances in these units of three different human cell types, which were recently space flown, i.e. bone mesenchymal stem cells, micro- and macrovascular endothelial cells. Endothelial cells are only slightly and transiently affected by culture in the EUs, whereas these devices accelerate mesenchymal stem cell reprogramming toward osteogenic differentiation, in part by increasing the amounts of reactive oxygen species. We conclude that cell culture conditions in the EUs do not exactly mimic what happens in a culture dish and that more efforts are necessary to optimize these devices for biomedical experiments in space. Impact statement Cell cultures represent valuable preclinical models to decipher pathogenic circuitries. This is true also for biomedical research in space. A lot has been learnt about cell adaptation and reaction from the experiments performed on many different cell types flown to space. Obviously, cell culture in space has to meet specific requirements for the safety of the crew and to comply with the unique environmental challenges. For these reasons, specific devices for cell culture in space have been developed. It is important to clarify whether these

  4. The thick aleurone1 mutant defines a negative regulation of maize aleurone cell fate that functions downstream of defective kernel1.

    Science.gov (United States)

    Yi, Gibum; Lauter, Adrienne M; Scott, M Paul; Becraft, Philip W

    2011-08-01

    The maize (Zea mays) aleurone layer occupies the single outermost layer of the endosperm. The defective kernel1 (dek1) gene is a central regulator required for aleurone cell fate specification. dek1 mutants have pleiotropic phenotypes including lack of aleurone cells, aborted embryos, carotenoid deficiency, and a soft, floury endosperm deficient in zeins. Here we describe the thick aleurone1 (thk1) mutant that defines a novel negative function in the regulation of aleurone differentiation. Mutants possess multiple layers of aleurone cells as well as aborted embryos. Clonal sectors of thk1 mutant tissue in otherwise normal endosperm showed localized expression of the phenotype with sharp boundaries, indicating a localized cellular function for the gene. Sectors in leaves showed expanded epidermal cell morphology but the mutant epidermis generally remained in a single cell layer. Double mutant analysis indicated that the thk1 mutant is epistatic to dek1 for several aspects of the pleiotropic dek1 phenotype. dek1 mutant endosperm that was mosaic for thk1 mutant sectors showed localized patches of multilayered aleurone. Localized sectors were surrounded by halos of carotenoid pigments and double mutant kernels had restored zein profiles. In sum, loss of thk1 function restored the ability of dek1 mutant endosperm to accumulate carotenoids and zeins and to differentiate aleurone. Therefore the thk1 mutation defines a negative regulator that functions downstream of dek1 in the signaling system that controls aleurone specification and other aspects of endosperm development. The thk1 mutation was found to be caused by a deletion of approximately 2 megabases.

  5. Changes in the thickness of the macular ganglion cell complex and retinal nerve fiber layer over time after surgery in a case of juvenile glaucoma

    Directory of Open Access Journals (Sweden)

    Seiji Takagi

    2016-07-01

    Conclusions and importance: In juvenile onset glaucoma, changes in c-RNFL thickness and m-GCC thickness after operation were not consistent with changes in optic disc cupping. Changes in the thicknesses of the c-RNFL or m-GCC, rather than changes in the optic disc changes, may be good surrogate measures to confirm the effectiveness of glaucoma surgery.

  6. A simple expression for the normal spectral emittance of open-cell foams composed of optically thick and smooth struts

    Science.gov (United States)

    Guévelou, Simon; Rousseau, Benoit; Domingues, Gilberto; Vicente, Jérôme

    2017-03-01

    A set of 96 open-cell foams with growing porosities (0.35-0.95) and growing pore nominal diameters (0.4-2.6 mm) was artificially generated to firmly connect their normal spectral emittances to their textural features. This work is strictly focused on foams that are composed of opaque struts with optically smooth surfaces. To compute the normal spectral emittances, a Monte Carlo Ray Tracing code was carefully used through an indirect method based on Kirchhoff's laws. The Monte Carlo Ray Tracing code considers the complex refractive index of the solid phase constituting the struts foams. Particular attention is therefore paid to performing the calculation with absorption indices (0.5-8) that preserve the opacity of each strut. From a thorough analysis of the ray transport within all the foams, where the Representative Elementary Volumes used for computing the homogenized radiative properties were known beforehand, a general and simple law is established that connects the normal spectral emittance, on the one hand, and the open porosity and the complex index of refraction, on the other hand. In the field of the thermal conversion of solar energy, for example, the new law gives relevant insight on the radiative performance of highly porous foams that are virtually coated with materials that are known for possessing an undeniable spectral selectivity when they are shaped as dense samples.

  7. A Negative Index Metamaterial-Inspired UWB Antenna with an Integration of Complementary SRR and CLS Unit Cells for Microwave Imaging Sensor Applications

    Directory of Open Access Journals (Sweden)

    Mohammad Tariqul Islam

    2015-05-01

    Full Text Available This paper presents a negative index metamaterial incorporated UWB antenna with an integration of complementary SRR (split-ring resonator and CLS (capacitive loaded strip unit cells for microwave imaging sensor applications. This metamaterial UWB antenna sensor consists of four unit cells along one axis, where each unit cell incorporates a complementary SRR and CLS pair. This integration enables a design layout that allows both a negative value of permittivity and a negative value of permeability simultaneous, resulting in a durable negative index to enhance the antenna sensor performance for microwave imaging sensor applications. The proposed MTM antenna sensor was designed and fabricated on an FR4 substrate having a thickness of 1.6 mm and a dielectric constant of 4.6. The electrical dimensions of this antenna sensor are 0.20 λ × 0.29 λ at a lower frequency of 3.1 GHz. This antenna sensor achieves a 131.5% bandwidth (VSWR < 2 covering the frequency bands from 3.1 GHz to more than 15 GHz with a maximum gain of 6.57 dBi. High fidelity factor and gain, smooth surface-current distribution and nearly omni-directional radiation patterns with low cross-polarization confirm that the proposed negative index UWB antenna is a promising entrant in the field of microwave imaging sensors.

  8. Teaching Basic Science Environmentally, The Concept: The cell is basic unit of structure of most organisms.

    Science.gov (United States)

    Busch, Phyllis S.

    1985-01-01

    Suggests simple ways to introduce students to the concept that the cell is the basic unit of structure of most organisms. Mentions materials for microscope study that are readily available and easy to handle, e.g., membranes from between the scales of the onion bulb, thin-leaved plants, pond water, and pollen. (JHZ)

  9. 3D-Printing Crystallographic Unit Cells for Learning Materials Science and Engineering

    Science.gov (United States)

    Rodenbough, Philip P.; Vanti, William B.; Chan, Siu-Wai

    2015-01-01

    Introductory materials science and engineering courses universally include the study of crystal structure and unit cells, which are by their nature highly visual 3D concepts. Traditionally, such topics are explored with 2D drawings or perhaps a limited set of difficult-to-construct 3D models. The rise of 3D printing, coupled with the wealth of…

  10. Predication of Plastic Flow Characteristics in Ferrite/Pearlite Steel Using a Fern Unit Cell Method

    Institute of Scientific and Technical Information of China (English)

    Hong Li; Jingtao Han; Jing Liu; Lv Zhang

    2004-01-01

    The flow stress of ferrite/pearlite steel under uni-axial tension was simulated with finite element method (FEM) by applying commercial software MARC/MENTAT. Flow stress curves of ferrite/pearlite steels were calculated based on unit cell model. The effects of volume fraction, distribution and the aspect ratio of pearlite on tensile properties have been investigated.

  11. 3D-Printing Crystallographic Unit Cells for Learning Materials Science and Engineering

    Science.gov (United States)

    Rodenbough, Philip P.; Vanti, William B.; Chan, Siu-Wai

    2015-01-01

    Introductory materials science and engineering courses universally include the study of crystal structure and unit cells, which are by their nature highly visual 3D concepts. Traditionally, such topics are explored with 2D drawings or perhaps a limited set of difficult-to-construct 3D models. The rise of 3D printing, coupled with the wealth of…

  12. Mitigation of Unwanted Forward Narrow-band Radiation from PCBs with a Metamaterial Unit Cell

    DEFF Research Database (Denmark)

    Ruaro, Andrea; Thaysen, Jesper; Jakobsen, Kaj Bjarne

    2013-01-01

    Mitigation of EMI from a PCB is obtained through the use of a metamaterial unit cell. The focus is on the reduction of narrow-band radiation in the forward hemisphere when the resonant element is etched on a layer located between the source of radiation and the ground plane. As opposed to previou...

  13. Recovery Act. Solid Oxide Fuel Cell Diesel Auxilliary Power Unit Demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Geiger, Gail E. [Delphi Automotive Systems, LLC., Gillingham (United Kingdom)

    2013-09-30

    Solid Oxide Fuel Cell Diesel Auxilliary Power Unit Demonstration Project. Summarizing development of Delphi’s next generation SOFC system as the core power plant to prove the viability of the market opportunity for a 3-5 kW diesel SOFC system. Report includes test and demonstration results from testing the diesel APU in a high visibility fleet customer vehicle application.

  14. Inulin isoforms differ by repeated additions of one crystal unit cell.

    Science.gov (United States)

    Cooper, Peter D; Barclay, Thomas G; Ginic-Markovic, Milena; Gerson, Andrea R; Petrovsky, Nikolai

    2014-03-15

    Inulin isoforms, especially delta inulin, are important biologically as immune activators and clinically as vaccine adjuvants. In exploring action mechanisms, we previously found regular increments in thermal properties of the seven-member inulin isoform series that suggested regular additions of some energetic structural unit. Because the previous isolates carried additional longer chains that masked defining ranges, these were contrasted with new isoform isolates comprising only inulin chain lengths defining that isoform. The new series began with 19 fructose units per chain (alpha-1 inulin), increasing regularly by 6 fructose units per isoform. Thus the 'energetic unit' equates to 6 fructose residues per chain. All isoforms showed indistinguishable X-ray diffraction patterns that were also identical with known inulin crystals. We conclude that an 'energetic unit' equates to one helix turn of 6 fructose units per chain as found in one unit cell of the inulin crystal. Each isoform chain comprised progressively more helix turns plus one additional fructose and glucose residues per chain.

  15. Question 7: the first units of life were not simple cells.

    Science.gov (United States)

    Norris, Vic; Hunding, Axel; Kepes, Francois; Lancet, Doron; Minsky, Abraham; Raine, Derek; Root-Bernstein, Robert; Sriram, K

    2007-10-01

    Five common assumptions about the first cells are challenged by the pre-biotic ecology model and are replaced by the following propositions: firstly, early cells were more complex, more varied and had a greater diversity of constituents than modern cells; secondly, the complexity of a cell is not related to the number of genes it contains, indeed, modern bacteria are as complex as eukaryotes; thirdly, the unit of early life was an 'ecosystem' rather than a 'cell'; fourthly, the early cell needed no genes at all; fifthly, early life depended on non-covalent associations and on catalysts that were not confined to specific reactions. We present here the outlines of a theory that connects findings about modern bacteria with speculations about their origins.

  16. Evaluation of bone marrow derived mesenchymal stem cells for full-thickness wound healing in comparison to tissue engineered chitosan scaffold in rabbit.

    Science.gov (United States)

    Rajabian, Mohammad Hossein; Ghorabi, Gholam Hossein; Geramizadeh, Bita; Sameni, Safoura; Ayatollahi, Maryam

    2017-02-01

    Chronic wounds present a major challenge in modern medicine. Even under optimal conditions, the healing process may lead to scarring and fibrosis. The ability of mesenchymal stem cells (MSCs) to differentiate into other cell types makes these cells an attractive therapeutic tool for cell transplantation. Both tissue-engineered construct and MSC therapy are among the current wound healing procedures and potential care. Chitosan has been widely applied in tissue engineering because of its biocompatibility and biodegradability. The aim of the current work was to compare the efficiency of MSCs and chitosan dressing, alone or in combination treatment on wound healing. This study was conducted on 15 rabbits, which were randomly divided in 3 groups based on the type of treatment with MSCs, chitosan dressing and combination of both. A full-thickness skin defect was excised from the right and left side of the back of each animals. Defects on right sides were filled with treatments and left side defects were left as control. Evaluation of the therapeutic effectiveness was performed through a variety of clinical and microscopical evaluations and measurements of the process of wound healing on days 7, 14, 21, and 28. Histological evaluation of wound healing was classified by different scoring systems. The data indicated that wounds treated with bone marrow derived MSC had enhanced cellularity and better epidermal regeneration. During the early stages of wound healing, the closure rate of bone marrow derived MSC-treated wounds were significantly higher than other treatments (Pchitosan treatment was slower than the control group. This study revealed advanced granulation tissue formation and epithelialization in wounds treated with MSCs, and may suggests this treatment as an effective applicant in wound healing process. Chitosan scaffold dressings, whether alone or in combination with MSCs, have worsened the wound healing as compared to the control group. Copyright © 2016

  17. A heated vapor cell unit for dichroic atomic vapor laser lock in atomic rubidium.

    Science.gov (United States)

    McCarron, Daniel J; Hughes, Ifan G; Tierney, Patrick; Cornish, Simon L

    2007-09-01

    The design and performance of a compact heated vapor cell unit for realizing a dichroic atomic vapor laser lock (DAVLL) for the D(2) transitions in atomic rubidium is described. A 5 cm long vapor cell is placed in a double-solenoid arrangement to produce the required magnetic field; the heat from the solenoid is used to increase the vapor pressure and correspondingly the DAVLL signal. We have characterized experimentally the dependence of important features of the DAVLL signal on magnetic field and cell temperature. For the weaker transitions both the amplitude and gradient of the signal are increased by an order of magnitude.

  18. Repair of full-thickness articular cartilage defects by cultured mesenchymal stem cells transfected with the transforming growth factor {beta}{sub 1} gene

    Energy Technology Data Exchange (ETDEWEB)

    Guo Xiaodong [Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022 (China); Zheng Qixin [Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022 (China); Yang Shuhua [Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022 (China); Shao Zengwu [Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022 (China); Yuan Quan [Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022 (China); Pan Zhengqi [Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022 (China); Tang Shuo [Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022 (China); Liu Kai [Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022 (China); Quan Daping [Institute of Polymer Science, School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275 (China)

    2006-12-15

    Articular cartilage repair remains a clinical and scientific challenge with increasing interest focused on the combined techniques of gene transfer and tissue engineering. Transforming growth factor beta 1 (TGF-{beta}{sub 1}) is a multifunctional molecule that plays a central role in promotion of cartilage repair, and inhibition of inflammatory and alloreactive immune response. Cell mediated gene therapy can allow a sustained expression of TGF-{beta}{sub 1} that may circumvent difficulties associated with growth factor delivery. The objective of this study was to investigate whether TGF-{beta}{sub 1} gene modified mesenchymal stem cells (MSCs) could enhance the repair of full-thickness articular cartilage defects in allogeneic rabbits. The pcDNA{sub 3}-TGF-{beta}{sub 1} gene transfected MSCs were seeded onto biodegradable poly-L-lysine coated polylactide (PLA) biomimetic scaffolds in vitro and allografted into full-thickness articular cartilage defects in 18 New Zealand rabbits. The pcDNA{sub 3} gene transfected MSCs/biomimetic scaffold composites and the cell-free scaffolds were taken as control groups I and II, respectively. The follow-up times were 2, 4, 12 and 24 weeks. Macroscopical, histological and ultrastructural studies were performed. In vitro SEM studies found that abundant cartilaginous matrices were generated and completely covered the interconnected pores of the scaffolds two weeks post-seeding in the experimental groups. In vivo, the quality of regenerated tissue improved over time with hyaline cartilage filling the chondral region and a mixture of trabecular and compact bone filling the subchondral region at 24 weeks post-implantation. Joint repair in the experimental groups was better than that of either control group I or II, with respect to: (1) synthesis of hyaline cartilage specific extracellular matrix at the upper portion of the defect; (2) reconstitution of the subchondral bone at the lower portion of the defect and (3) inhibition of

  19. The thickness of glaciers

    Science.gov (United States)

    Faraoni, Valerio; Vokey, Marshall W.

    2015-09-01

    Basic formulae and results of glacier physics appearing in glaciology textbooks can be derived from first principles introduced in algebra-based first year physics courses. We discuss the maximum thickness of alpine glaciers and ice sheets and the relation between maximum thickness and length of an ice sheet. Knowledge of ordinary differential equations allows one to derive also the local ice thickness.

  20. A switchable pH-differential unitized regenerative fuel cell with high performance

    Science.gov (United States)

    Lu, Xu; Xuan, Jin; Leung, Dennis Y. C.; Zou, Haiyang; Li, Jiantao; Wang, Hailiang; Wang, Huizhi

    2016-05-01

    Regenerative fuel cells are a potential candidate for future energy storage, but their applications are limited by the high cost and poor round-trip efficiency. Here we present a switchable pH-differential unitized regenerative fuel cell capable of addressing both the obstacles. Relying on a membraneless laminar flow-based design, pH environments in the cell are optimized independently for different electrode reactions and are switchable together with the cell process to ensure always favorable thermodynamics for each electrode reaction. Benefiting from the thermodynamic advantages of the switchable pH-differential arrangement, the cell allows water electrolysis at a voltage of 0.57 V, and a fuel cell open circuit voltage of 1.89 V, rendering round-trip efficiencies up to 74%. Under room conditions, operating the cell in fuel cell mode yields a power density of 1.3 W cm-2, which is the highest performance to date for laminar flow-based cells and is comparable to state-of-the-art polymer electrolyte membrane fuel cells.

  1. A fuel cell energy storage system concept for the Space Station Freedom Extravehicular Mobility Unit

    Science.gov (United States)

    Adlhart, Otto J.; Rosso, Matthew J., Jr.; Marmolejo, Jose

    1989-01-01

    An update is given on work to design and build a Fuel Cell Energy Storage System (FCESS) bench-tested unit for the Space Station Freedom Extravehicular Mobility Unit (EMU). Fueled by oxygen and hydride-stored hydrogen, the FCESS is being considered as an alternative to the EMU zinc-silver oxide battery. Superior cycle life and quick recharge are the main attributes of FCESS. The design and performance of a nonventing, 28 V, 34 Ahr system with 7 amp rating are discussed.

  2. Single-unit transfusions and hemoglobin trigger: relative impact on red cell utilization.

    Science.gov (United States)

    Yang, William W; Thakkar, Rajiv N; Gehrie, Eric A; Chen, Weiyun; Frank, Steven M

    2017-05-01

    Patient blood management (PBM) programs can reduce unnecessary transfusions, but the optimal methods used to achieve this effect are unclear. We tested the hypothesis that encouraging single-unit red blood cell (RBC) transfusions in stable patients would have a greater impact on blood use than compliance with a specific hemoglobin (Hb) transfusion trigger alone. We analyzed blood utilization data at three community hospitals without previous PBM efforts before and after implementing a PBM program. Data were analyzed at monthly intervals to determine the relative impact of a "Why give 2 when 1 will do?" campaign promoting single-unit RBC transfusions and simultaneous efforts to promote evidence-based Hb triggers of 7 or 8 g/dL. Univariate and multivariate analyses were used to identify independent effects of these two interventions on overall RBC utilization. Univariate analysis revealed that both the increase in single-unit transfusions (from 38.0% to 70.9%; p utilization. Multivariate analysis showed that the increase in single-unit transfusions was an independent predictor of decreased RBC utilization, but the Hb triggers of both 7 and 8 g/dL were not. Overall, our PBM efforts decreased RBC utilization from 0.254 to 0.185 units/patient (27.2%) across all three hospitals (p = 0.0009). A campaign promoting single-unit RBC transfusions had a greater impact on RBC utilization than did encouraging a restrictive transfusion trigger. © 2016 AABB.

  3. The Daniell Cell, Ohm's Law and the Emergence of the International System of Units

    CERN Document Server

    Jayson, Joel S

    2015-01-01

    Telegraphy originated in the 1830s and 40s and flourished in the following decades, but with a patchwork of electrical standards. Electromotive force was for the most part measured in units of the predominant Daniell cell. Each company had their own resistance standard. In 1862 the British Association for the Advancement of Science formed a committee to address this situation. By 1873 they had given definition to the electromagnetic system of units (emu) and defined the practical units of the ohm as ${10}^9$ emu units of resistance and the volt as ${10}^8$ emu units of electromotive force. These recommendations were ratified and expanded upon in a series of international congresses held between 1881 and 1904. A proposal by Giovanni Giorgi in 1901 took advantage of a coincidence between the conversion of the units of energy in the emu system (the erg) and in the practical system (the joule) in that the same conversion factor existed between the cgs based emu system and a theretofore undefined MKS system. By in...

  4. A plasma-based biomatrix mixed with endothelial progenitor cells and keratinocytes promotes matrix formation, angiogenesis, and reepithelialization in full-thickness wounds.

    Science.gov (United States)

    Vermeulen, Pieter; Dickens, Stijn; Degezelle, Karlien; Van den Berge, Stefaan; Hendrickx, Benoit; Vranckx, Jan Jeroen

    2009-07-01

    In search of an autologous vascularized skin substitute, we treated full-thickness wounds (FTWs) with autologous platelet-rich plasma gel (APG) in which we embedded endothelial progenitor cells (EPCs) and basal cell keratinocytes (KCs). We cultivated autologous KCs in low-serum conditions and expanded autologous EPCs from venous blood. FTWs (n = 55) were created on the backs of four pigs, covered with wound chambers, and randomly assigned to the following treatments: (1) APG, (2) APG + KCs, (3) APG + EPCs, (4) APG + KCs + EPCs, and (5) saline. All wounds were biopsied to measure neovascularization (lectin Bandeiraea Simplicifolia-1 (BS-1), alpha smooth muscle actin [alphaSMA], and membrane type 1 matrix metalloproteinase (MT1-MMP)), matrix deposition (fibronectin, collagen type I/III, and alphavbeta3), and reepithelialization. Wound fluids were analyzed for protein expression. All APG-treated wounds showed more vascular structures (p < 0.001), and the addition of EPCs further improved neovascularization, as confirmed by higher lectin, alphaSMA, and MT1-MMP. APG groups had higher collagen I/III (p < 0.05), alphavbeta3, and fibronectin content (p < 0.001), and they exhibited higher concentrations of platelet-derived growth factor subunit bb, basic fibroblast growth factor, hepatocyte growth factor, insulin growth factor-1, transforming growth factor-beta1 and -beta3, matrix metalloproteinase-1 and -z9, and tissue-inhibiting matrix metalloproteinase-1 and -2. Applying APG + KCs resulted in the highest reepithelialization rates (p < 0.001). No differences were found for wound contraction by planimetry. In this porcine FTW model, APG acts as a supportive biomatrix that, along with the embedded cells, improves extracellular matrix organization, promotes angiogenesis, and accelerates reepithelialization.

  5. Regulations in the United States for cell transplantation clinical trials in neurological diseases

    Institute of Scientific and Technical Information of China (English)

    He Zhu; Yuanqing Tan; Qi Gu; Weifang Han; Zhongwen Li; Jason S Meyer; Baoyang Hu

    2015-01-01

    Objective: This study aimed to use a systematic approach to evaluate the current utilization, safety, and effectiveness of cell therapies for neurological diseases in human. And review the present regulations, considering United States (US) as a representative country, for cell transplantation in neurological disease and discuss the challenges facing the field of neurology in the coming decades. Methods:A detailed search was performed in systematic literature reviews of cellular‐based therapies in neurological diseases, using PubMed, web of science, and clinical trials. Regulations of cell therapy products used for clinical trials were searched from the Food and Drug Administration (FDA) and the National Institutes of Health (NIH). Results: Seven most common types of cell therapies for neurological diseases have been reported to be relatively safe with varying degrees of neurological recovery. And a series of regulations in US for cellular therapy was summarized including preclinical evaluations, sourcing material, stem cell manufacturing and characterization, cell therapy product, and clinical trials. Conclusions:Stem cell‐based therapy holds great promise for a cure of such diseases and will value a growing population of patients. However, regulatory permitting activity of the US in the sphere of stem cells, technologies of regenerative medicine and substitutive cell therapy are selective, theoretical and does not fit the existing norm and rules. Compiled well‐defined regulations to guide the application of stem cell products for clinical trials should be formulated.

  6. Fuel cell collaboration in the United States. Follow up report to the Danish Partnership for Hydrogen and Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-01-15

    Fuel cell technology continues to grow in the United States, with strong sales in stationary applications and early markets such as data centers, materials handling equipment, and telecommunications sites. New fuel cell customers include Fortune 500 companies Apple, eBay, Coca-Cola, and Walmart, who will use fuel cells to provide reliable power to data centers, stores, and facilities. Some are purchasing multi-megawatt (MW) systems, including three of the largest non-utility purchases of stationary fuel cells in the world by AT and T, Apple and eBay - 17 MW, 10 MW and 6 MW respectively. Others are replacing fleets of battery forklifts with fuel cells. Sysco, the food distributor, has more than 700 fuel cell-powered forklifts operating at seven facilities, with more on order. Mega-retailer Walmart now operates more than 500 fuel cell forklifts at three warehouses, including a freezer facility. Although federal government budget reduction efforts are impacting a wide range of departments and programs, fuel cell and hydrogen technology continues to be funded, albeit at a lower level than in past years. The Department of Energy (DOE) is currently funding fuel cell and hydrogen R and D and has nearly 300 ongoing projects at companies, national labs, and universities/institutes universities. The American Recovery and Reinvestment Act (ARRA) of 2009 and DOE's Market Transformation efforts have acted as a government ''catalyst'' for market success of emerging technologies. Early market deployments of about 1,400 fuel cells under the ARRA have led to more than 5,000 additional fuel cell purchases by industry with no DOE funding. In addition, interest in Congress remains high. Senators Richard Blumenthal (D-CT), Chris Coons (D-DE), Lindsey Graham (R-SC) and John Hoeven (R-ND) re-launched the bipartisan Senate Fuel Cell and Hydrogen Caucus in August 2012 to promote the continued development and commercialization of hydrogen and fuel cell technologies

  7. Study on Unit Cell Models and the Effective Thermal Conductivities of Silica Aerogel.

    Science.gov (United States)

    Liu, He; Li, Zeng-Yao; Zhao, Xin-Peng; Tao, Wen-Quan

    2015-04-01

    In this paper, two modified unit cell models, truncated octahedron and cubic array of intersecting square rods with 45-degree rotation, are developed in consideration of the tortuous path of heat conduction in solid skeleton of silica aerogel. The heat conduction is analyzed for each model and the expressions of effective thermal conductivity of the modified unit cell models are derived. Considering the random microstructure of silica aerogel, the probability model is presented. We also discuss the effect of the thermal conductivity of aerogel backbone. The effective thermal conductivities calculated by the proposed probability model are in good agreement with available experimental data when the density of the aerogel is 110 kg/m3.

  8. Effects of TiO{sub 2} film thickness on photovoltaic properties of dye-sensitized solar cell and its enhanced performance by graphene combination

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Haiyan, E-mail: hyzhang@gdut.edu.cn [School of Materials and Energy, Guangdong University of Technology, Guangzhou Higher Education Mega Center 100#, Guangzhou 510006 (China); Wang, Wenguang; Liu, Hui; Wang, Rong; Chen, Yiming [School of Materials and Energy, Guangdong University of Technology, Guangzhou Higher Education Mega Center 100#, Guangzhou 510006 (China); Wang, Zhiwei [Anhui Key Laboratory of Nanomaterials and Nanostructures Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China)

    2014-01-01

    Graphical abstract: - Highlights: • DSSC based on TiO{sub 2} film with 8 printing layers showed the highest efficiency. • The photoelectric conversion efficiency of the DSSC increased from 5.52% to 6.49% by graphene combination. • A mechanism for the enhanced performance of the DSSC was proposed. - Abstract: Dye-sensitized solar cells based on TiO{sub 2} films with different printing layers (6-10) were fabricated by screen printing method. The prepared samples were characterized by scanning electron microscopy, X-ray diffraction and UV–vis absorption spectroscopy. The effects of thickness on the photoelectric conversion performance of the as-fabricated DSSCs were investigated. An optimum photoelectric conversion efficiency of 5.52% was obtained in a DSSC with 8 printing layers. Furthermore, after a moderate amount of graphene was combined with TiO{sub 2}, the photoelectric conversion efficiency of the DSSC based on graphene/TiO{sub 2} composite film rose from 5.52% to 6.49%, with an increase of η by 17.6%. The results indicated that graphene not only enhances the transport of electrons from the film to the fluorine doped tin oxide substrates and reduces the charge recombination rate, but also reduces the electrolyte–electrode interfacial resistance, clearly increasing the photoelectric conversion efficiency.

  9. TSG-6 released from intradermally injected mesenchymal stem cells accelerates wound healing and reduces tissue fibrosis in murine full-thickness skin wounds.

    Science.gov (United States)

    Qi, Yu; Jiang, Dongsheng; Sindrilaru, Anca; Stegemann, Agatha; Schatz, Susanne; Treiber, Nicolai; Rojewski, Markus; Schrezenmeier, Hubert; Vander Beken, Seppe; Wlaschek, Meinhard; Böhm, Markus; Seitz, Andreas; Scholz, Natalie; Dürselen, Lutz; Brinckmann, Jürgen; Ignatius, Anita; Scharffetter-Kochanek, Karin

    2014-02-01

    Proper activation of macrophages (Mφ) in the inflammatory phase of acute wound healing is essential for physiological tissue repair. However, there is a strong indication that robust Mφ inflammatory responses may be causal for the fibrotic response always accompanying adult wound healing. Using a complementary approach of in vitro and in vivo studies, we here addressed the question of whether mesenchymal stem cells (MSCs)-due to their anti-inflammatory properties-would control Mφ activation and tissue fibrosis in a murine model of full-thickness skin wounds. We have shown that the tumor necrosis factor-α (TNF-α)-stimulated protein 6 (TSG-6) released from MSCs in co-culture with activated Mφ or following injection into wound margins suppressed the release of TNF-α from activated Mφ and concomitantly induced a switch from a high to an anti-fibrotic low transforming growth factor-β1 (TGF-β1)/TGF-β3 ratio. This study provides insight into what we believe to be a previously undescribed multifaceted role of MSC-released TSG-6 in wound healing. MSC-released TSG-6 was identified to improve wound healing by limiting Mφ activation, inflammation, and fibrosis. TSG-6 and MSC-based therapies may thus qualify as promising strategies to enhance tissue repair and to prevent excessive tissue fibrosis.

  10. Clinical significance of three-dimensional measurement of tumour thickness on magnetic resonance imaging in patients with oral tongue squamous cell carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Minsu [Gyeongsang National University Hospital, School of Medicine, Department of Otorhinolaryngology, Jinju (Korea, Republic of); Moon, Hyun; Nam, Soon Yuhl; Kim, Ji Won; Lee, Yoon-Se; Roh, Jong-Lyel; Choi, Seung-Ho [University of Ulsan College of Medicine, Department of Otolaryngology, Asan Medical Centre, Seoul (Korea, Republic of); Lee, Jeong Hyun [University of Ulsan College of Medicine, Department of Radiology, Asan Medical Centre, Seoul (Korea, Republic of); Kim, Sang-Yoon [University of Ulsan College of Medicine, Department of Otolaryngology, Asan Medical Centre, Seoul (Korea, Republic of); Korea Institute of Science and Technology, Biomedical Research Institute, Seoul (Korea, Republic of)

    2016-03-15

    To identify the clinical significance of primary tumour thickness (TT) and its direction in patients with oral tongue squamous cell carcinoma (OTSCC), we measured TT in all axial/coronal/sagittal views on magnetic resonance imaging (MRI) and evaluated their meaning. A total of 53 OTSCC patients were analysed who had undergone preoperative three-dimensional MRI and had been surgically treated. TT measured on axial (mediolateral direction), coronal (superoinferior direction), and sagittal (anteroposterior direction) views was compared to that in pathologic specimens. The association between TT on MRI and other pathologic parameters was also evaluated. TT on MRI in each plane showed relatively high concordance rates with the histological measurements. TT in all three planes was significantly correlated with lymph node (LN) metastasis. Occult LN metastasis was found in 15 of 39 (38.5 %) patients, and the cutoff value of TT in axial/coronal/sagittal MRI predicting occult LN metastasis was 6.7 mm, 7.2 mm, and 12.3 mm, respectively. TT on MRI did not show any significant association with recurrence and survival. TT on MRI in all three planes showed relatively high coincidence with TT on histopathology and presented a potential cut-off value as a predictive indicator for occult LN metastasis. (orig.)

  11. Study of Dye-Sensitized Solar Cells by Scanning Electron Micrograph Observation and Thickness Optimization of Porous TiO2 Electrodes

    Directory of Open Access Journals (Sweden)

    Seigo Ito

    2009-01-01

    Full Text Available In order to improve the photoenergy conversion efficiency of dye-sensitized solar cells (DSCs, it is important to optimize their porous TiO2 electrodes. This paper examines the surface and cross-sectional views of the electrodes using scanning electron micrography. Two types of samples for cross-sectional viewing were prepared by mechanically breaking the substrate and by using an Ar-ion etching beam. The former displays the surface of the TiO2 particles and the latter shows the cross-section of the TiO2 particles. We found interesting surface and cross-sectional structures in the scattering layer containing the 400 nm diameter particles, which have an angular and horned shape. The influence of TiO2 particle size and the thickness of the nanocrystalline-TiO2 electrode in DSCs using four kinds of sensitizing dyes (D149, K19, N719 and Z907 and two kinds of electrolytes (acetonitrile-based and ionic-liquid electrolytes are discussed in regards to conversion efficiency, which this paper aims to optimize.

  12. On the Performance of Hybrid PV/Unitized Regenerative Fuel Cell System in the Tropics

    Directory of Open Access Journals (Sweden)

    Salwan Dihrab

    2012-01-01

    Full Text Available Solar hydrogen system is a unique power system that can meet the power requirements for future energy demands. Such a system uses the hydrogen as the energy carrier, which produces energy through the electrolyzer with assistance of the power from the PV during the sunny hours, and then uses stored hydrogen to produce energy through the fuel cell after sunset or on cloudy days. The current study has used premanufactured unitized regenerative fuel cells in which the electrolyzer and the fuel cell function within one cell at different modes. The system components were modeled and the one-day real operational and simulated data has been presented and compared. The measured results showed the ability of the system to meet the proposed load, and the total efficiency was about 4.5%.

  13. BioDiff - a neutron diffractometer optimized for crystals with large unit cell dimensions

    OpenAIRE

    Schrader, Tobias Erich; Ostermann, Andreas; Monkenbusch, Michael; Laatsch, Bernhard; Jüttner, Philipp; Petry, Winfried; Richter, Dieter

    2014-01-01

    The research reactor Heinz Maier-Leibnitz (FRM II) is a modern high flux neutron source which feeds some 30 state of the art neutron beam instruments. Currently 24 are operational, others in commissioning or under construction. The newly built neutron single crystal diffractometer BIODIFF is especially designed to collect data from crystals with large unit cells. The main field of application is the structural analysis of proteins, especially the determination of hydrogen atom positions. BIOD...

  14. Dielectric Behavior of Low Microwave Loss Unit Cell for All Dielectric Metamaterial

    Directory of Open Access Journals (Sweden)

    Tianhuan Luo

    2015-01-01

    Full Text Available With a deep study of the metamaterial, its unit cells have been widely extended from metals to dielectrics. The dielectric based unit cells attract much attention because of the advantage of easy preparation, tunability, and higher frequency response, and so forth. Using the conventional solid state method, we prepared a kind of incipient ferroelectrics (calcium titanate, CaTiO3 with higher microwave permittivity and lower loss, which can be successfully used to construct metamaterials. The temperature and frequency dependence of dielectric constant are also measured under different sintering temperatures. The dielectric spectra showed a slight permittivity decrease with the increase of temperature and exhibited a loss of 0.0005, combined with a higher microwave dielectric constant of ~167 and quality factor Q of 2049. Therefore, CaTiO3 is a kind of versatile and potential metamaterial unit cell. The permittivity of CaTiO3 at higher microwave frequency was also examined in the rectangular waveguide and we got the permittivity of 165, creating a new method to test permittivity at higher microwave frequency.

  15. Preparation of ultra-thin and high-quality WO3 compact layers and comparision of WO3 and TiO2 compact layer thickness in planar perovskite solar cells

    Science.gov (United States)

    Zhang, Jincheng; Shi, Chengwu; Chen, Junjun; Wang, Yanqing; Li, Mingqian

    2016-06-01

    In this paper, the ultra-thin and high-quality WO3 compact layers were successfully prepared by spin-coating-pyrolysis method using the tungsten isopropoxide solution in isopropanol. The influence of WO3 and TiO2 compact layer thickness on the photovoltaic performance of planar perovskite solar cells was systematically compared, and the interface charge transfer and recombination in planar perovskite solar cells with TiO2 compact layer was analyzed by electrochemical impedance spectroscopy. The results revealed that the optimum thickness of WO3 and TiO2 compact layer was 15 nm and 60 nm. The planar perovskite solar cell with 15 nm WO3 compact layer gave a 9.69% average and 10.14% maximum photoelectric conversion efficiency, whereas the planar perovskite solar cell with 60 nm TiO2 compact layer achieved a 11.79% average and 12.64% maximum photoelectric conversion efficiency.

  16. Investigation on the Effect of the CdCl2 Treatment on CdTe Thin-film Solar Cells of Variable Thickness Fabricated Using Combinatorial Pulsed Laser Deposition

    Science.gov (United States)

    Kadhim, Ali Saber

    Cadmium Chloride (CdCl2) post annealing process has significant impacts on the performance of the CdS/CdTe solar cells since it affects the microstructure, crystallinity and charge carrier doping in CdTe films and also the CdS/CdTe p-n junction formed through S and Te interdiffusion at the junction interface. Therefore, this process has been investigated extensively during the past two decades, and has been optimized for polycrystalline CdS/CdTe thick film solar cells, in which the CdTe thickness is typically in the range of 3-8 microm. Nevertheless, the recent effort to develop cost-performance balanced thin film CdS/CdTe solar cells (with CdTe thickness on the order of 1 microm or less) has encountered difficulties through direct applications of the thick-film CdCl2 post annealing process. These difficulties stem from the large CdTe grain sizes typically in the range of microns in the thick film case. Grain boundaries between such large grains result in through-thickness shorts when the CdTe film thickness is comparable to or smaller than the grain size. Overcoming these difficulties to achieve precise controls of grain morphology, crystallinity and CdS/CdTe interface is important to high-performance CdS/CdTe thin film solar cells and will be the main objective of this thesis. In order to accelerate the study, a combinatorial Pulsed Laser Deposition technique (cPLD) was developed for deposition of CdTe films with different thicknesses on each sample to elucidate important physical properties of Cl diffusion through the selected thickness range at a given CdCl 2 annealing condition. Two sets of samples A and B of CdTe solar cells of multiple thicknesses of 1.5, 1.25, 1.0, and 0.75 microm have been fabricated by using cPLD. Sample A was completed without CdCl2 treatment as a reference, and sample B was treated with CdCl2 in different durations (10, 12, 15, and 17 min) at 360°C in mixed vapor of O2 and Argon (25 sccm:100 sccm). The sample that was treated at 15

  17. Preparation of ultra-thin and high-quality WO{sub 3} compact layers and comparision of WO{sub 3} and TiO{sub 2} compact layer thickness in planar perovskite solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jincheng; Shi, Chengwu, E-mail: shicw506@foxmail.com; Chen, Junjun; Wang, Yanqing; Li, Mingqian

    2016-06-15

    In this paper, the ultra-thin and high-quality WO{sub 3} compact layers were successfully prepared by spin-coating-pyrolysis method using the tungsten isopropoxide solution in isopropanol. The influence of WO{sub 3} and TiO{sub 2} compact layer thickness on the photovoltaic performance of planar perovskite solar cells was systematically compared, and the interface charge transfer and recombination in planar perovskite solar cells with TiO{sub 2} compact layer was analyzed by electrochemical impedance spectroscopy. The results revealed that the optimum thickness of WO{sub 3} and TiO{sub 2} compact layer was 15 nm and 60 nm. The planar perovskite solar cell with 15 nm WO{sub 3} compact layer gave a 9.69% average and 10.14% maximum photoelectric conversion efficiency, whereas the planar perovskite solar cell with 60 nm TiO{sub 2} compact layer achieved a 11.79% average and 12.64% maximum photoelectric conversion efficiency. - Graphical abstract: The planar perovskite solar cell with 15 nm WO{sub 3} compact layer gave a 9.69% average and 10.14% maximum photoelectric conversion efficiency, whereas the planar perovskite solar cell with 60 nm TiO{sub 2} compact layer achieved a 11.79% average and 12.64% maximum photoelectric conversion efficiency. Display Omitted - Highlights: • Preparation of ultra-thin and high-quality WO{sub 3} compact layers. • Perovskite solar cell with 15 nm-thick WO{sub 3} compact layer achieved PCE of 10.14%. • Perovskite solar cell with 60 nm-thick TiO{sub 2} compact layer achieved PCE of 12.64%.

  18. A Dermal Equivalent Engineered with TGF-β3 Expressing Bone Marrow Stromal Cells and Amniotic Membrane: Cosmetic Healing of Full-Thickness Skin Wounds in Rats.

    Science.gov (United States)

    Samadikuchaksaraei, Ali; Mehdipour, Ahmad; Habibi Roudkenar, Mehryar; Verdi, Javad; Joghataei, Mohammad Taghi; As'adi, Kamran; Amiri, Fatemeh; Dehghan Harati, Mozhgan; Gholipourmalekabadi, Mazaher; Karkuki Osguei, Nushin

    2016-12-01

    Transforming growth factor beta-3 (TGF-β3) has been shown to decrease scar formation after scheduled topical applications to the cutaneous wounds. This study aimed to continuously deliver TGF-β3, during the early phase of wound healing, by engineering a dermal equivalent (DE) using TGF-β3 expressing bone marrow stromal cells (BM-SCs) and human dehydrated amniotic membrane (hDAM). To engineer a DE, rat BM-SCs were seeded on the hDAM and TGF-β3 was transiently transfected into the BM-SCs using a plasmid vector. Pieces of the dermal equivalent were transplanted onto the full-thickness excisional skin wounds in rats. The process of wound healing was assessed by image analysis, Manchester Scar Scale (MSS), and histopathological studies 7, 14, 21, and 85 days after the excision. The results confirmed accurate construction of recombinant pcDNA3.1-TGF-β3 expression system and showed that the transfected BM-SCs seeded on hDAM expressed TGF-β3 mRNA and protein from day 3 through day 7 after transfection. After implantation of the DE, contraction of the wounds was measured from day 7 through 21 and analyzed by linear regression, which revealed that the rate of wound contraction in all experimental groups was similar. Histologic evaluation demonstrated that transfected BM-SCs decreased retention and recruitment of the cells during the early stage of wound healing, decreased the formation of vascular structures and led to formation of uniformly parallel collagen bundles. MSS scores showed that TGF-β3 secreting cells significantly improved the cosmetic appearance of the healed skin and decreased the scar formation. From these results, it could be concluded that transient secretion of TGF-β3, during the early phase of healing, by BM-SCs seeded on hDAM can improve the cosmetic appearance of the scar in cutaneous wounds without negatively affecting the process of wound repair. Copyright © 2016 International Center for Artificial Organs and Transplantation and Wiley

  19. Education and "Thick" Epistemology

    Science.gov (United States)

    Kotzee, Ben

    2011-01-01

    In this essay Ben Kotzee addresses the implications of Bernard Williams's distinction between "thick" and "thin" concepts in ethics for epistemology and for education. Kotzee holds that, as in the case of ethics, one may distinguish between "thick" and "thin" concepts of epistemology and, further, that this distinction points to the importance of…

  20. Thick film hydrogen sensor

    Science.gov (United States)

    Hoffheins, Barbara S.; Lauf, Robert J.

    1995-01-01

    A thick film hydrogen sensor element includes an essentially inert, electrically-insulating substrate having deposited thereon a thick film metallization forming at least two resistors. The metallization is a sintered composition of Pd and a sinterable binder such as glass frit. An essentially inert, electrically insulating, hydrogen impermeable passivation layer covers at least one of the resistors.

  1. Study on Relationship between the Thickness of Tongue Fur and the Expressions of Apoptosis-related Genes of the Tongue Epithelial Cells in Patients with Diseases of the Digestive System

    Institute of Scientific and Technical Information of China (English)

    Wu Zhengzhi; Li Ming; Zhang Yongfeng; Chen Manyin

    2007-01-01

    To investigate the relationship between the thickness of tongue fur, apoptosis of the tongue fur epithelial cells and expressions of apoptosis-related genes in diseases of the digestive system,apoptosis-related genes TGF-β3, fas mRNA and protein products were detected with terminal deoxynucleotidyl transferase-mediated deoxyurine triphosphate (d-UTP) nick-end labeling(TUNEL)technique, in situ hybridization, immunohistochemical methods, and image analysis technique,respectively. Results indicated that compared with the normal tongue fur, over-expression of fas gene was found in the peeling fur with an increase in cell apoptosis, while a low-expression of TGF-β3 in the thick fur with a decrease in cell apoptosis. The changes in expression levels of fas and TGF-β3 genes,apoptosis-promoting genes in the tongue fur epithelial cells, had a similar tendency of cell apoptosis level.It is concluded that the changes in expression levels of fas and TGF-β3 are possibly important reasons influencing apoptosis of epithelial cells of tongue fur and leading to changes in thickness of the tongue fur.

  2. Interface-Induced High-Temperature Superconductivity in Single Unit-Cell FeSe Films on SrTiO3

    Institute of Scientific and Technical Information of China (English)

    WANG Qing-Yan; CHANG Kai; WEN Jing; SONG Can-Li; HE Ke; JIA Jin-Feng; JI Shuai-Hua; WANG Ya-Yu; WANG Li-Li; CHEN Xi; MA Xu-Cun; LI Zhi; XUE Qi-Kun; ZHANG Wen-Hao; ZHANG Zuo-Cheng; ZHANG Jin-Song; LI Wei; DING Hao; OU Yun-Bo; DENG Peng

    2012-01-01

    We report high transition temperature superconductivity in one unit-cell (UC) thick FeSe films grown on a Seetched SrTiO3 (001) substrate by molecular beam epitaxy (MBE).A superconducting gap as large as 20 meV and the magnetic field induced vortex state revealed by in situ scanning tunneling microscopy (STM) suggest that the superconductivity of the 1 UC FeSe films could occur around 77K.The control transport measurement shows that the onset superconductivity temperature is well above 50K.Our work not only demonstrates a powerful way for finding new superconductors and for raising Tc,but also provides a well-defined platform for systematic studies of the mechanism of unconventional superconductivity by using different superconducting materials and substrates.

  3. Major design issues of molten carbonate fuel cell power generation unit

    Energy Technology Data Exchange (ETDEWEB)

    Chen, T.P.

    1996-04-01

    In addition to the stack, a fuel cell power generation unit requires fuel desulfurization and reforming, fuel and oxidant preheating, process heat removal, waste heat recovery, steam generation, oxidant supply, power conditioning, water supply and treatment, purge gas supply, instrument air supply, and system control. These support facilities add considerable cost and system complexity. Bechtel, as a system integrator of M-C Power`s molten carbonate fuel cell development team, has spent substantial effort to simplify and minimize these supporting facilities to meet cost and reliability goals for commercialization. Similiar to other fuels cells, MCFC faces design challenge of how to comply with codes and standards, achieve high efficiency and part load performance, and meanwhile minimize utility requirements, weight, plot area, and cost. However, MCFC has several unique design issues due to its high operating temperature, use of molten electrolyte, and the requirement of CO2 recycle.

  4. Definitions of radioisotope thick target yields

    Energy Technology Data Exchange (ETDEWEB)

    Otuka, Naohiko [International Atomic Energy Agency, Wien (Austria). Nuclear Data Section; Takacs, Sandor [Hungarian Academy of Science, Debrecen (Hungary). Inst. of Nuclear Research

    2015-05-01

    Definitions of thick target yields are reviewed in relation to their documentation for the experimental nuclear reaction data library (database). Researchers reporting experimental thick target yields are urged to define their yields clearly with an appropriate unit in order to compile them in the experimental data library (EXFOR) in a consistent manner, and also to properly utilise them for comparison with other experimental and evaluated yields.

  5. Cell phone recycling experiences in the United States and potential recycling options in Brazil.

    Science.gov (United States)

    Silveira, Geraldo T R; Chang, Shoou-Yuh

    2010-11-01

    This paper presents an overview of cell phone recycling programs currently available in the United States. At the same time, it also provides analyses of the current recycling situation and possible recycling alternatives for Brazil. Although there are several recycling options in the United States, collection rates are still only 10% of all potential devices because customers are not aware of these possibilities. The whole system is financially based on reselling refurbished cell phones and recycled materials to developing countries which represent an effective and strong market. Several recyclers offer funds to collection partners who are either charities or who work with charities while obtaining the materials that they need in order to run their operations. A mobile phone recycling system for Brazil considering the United States experience and the Extended Producer Responsibility (EPR) principle is suggested. A deposit/refund/advance-recycling fee is proposed which might be implemented as a voluntary industrial initiative managed by PRO Brazil, a producer responsibility organization. One widespread public-private agreement will integrate all mobile phone stakeholders, and environmental education actions and promotional events will promote citizen's participation.

  6. Effect of a Mediterranean diet on endothelial progenitor cells and carotid intima-media thickness in type 2 diabetes: Follow-up of a randomized trial.

    Science.gov (United States)

    Maiorino, Maria Ida; Bellastella, Giuseppe; Petrizzo, Michela; Gicchino, Maurizio; Caputo, Mariangela; Giugliano, Dario; Esposito, Katherine

    2017-03-01

    Background We assessed the long-term effects of a Mediterranean diet on circulating levels of endothelial progenitor cells (EPCs) and the carotid intima-media thickness (CIMT) in patients with type 2 diabetes. Design This was a parallel, two-arm, single-centre trial. Methods Two hundred and fifteen men and women with newly diagnosed type 2 diabetes were randomized to a Mediterranean diet ( n = 108) or a low-fat diet ( n = 107). The primary outcome measures were changes in the EPC count and the CIMT of the common carotid artery after the treatment period defined as the end of trial (EOT). Results At the EOT, both the CD34(+)KDR(+) and CD34(+)KDR(+)CD133(+) counts had increased with the Mediterranean diet compared with the low-fat diet ( p Mediterranean diet. Compared with the low-fat diet, the rate of regression in the CIMT was higher in the Mediterranean diet group (51 vs. 26%), whereas the rate of progression was lower (25 vs. 50%) ( p = 0.032 for both). Changes in the CIMT were inversely correlated with the changes in EPC levels (CD34(+)KDR(+), r = -0.24, p = 0.020; CD34(+)KDR(+)CD133(+), r = -0.28, p = 0.014). At the EOT, changes in levels of HbA1c, HOMA, total cholesterol, high-density lipoprotein cholesterol and systolic blood pressure were significantly greater with the Mediterranean diet than with the low-fat diet. Conclusion Compared with a low-fat diet, a long-term trial with Mediterranean diet was associated with an increase in circulating EPCs levels and prevention of the progression of subclinical atherosclerosis in patients with newly diagnosed type 2 diabetes.

  7. Planar conjugated polymers containing 9,10-disubstituted phenanthrene units for efficient polymer solar cells.

    Science.gov (United States)

    Li, Guangwu; Kang, Chong; Li, Cuihong; Lu, Zhen; Zhang, Jicheng; Gong, Xue; Zhao, Guangyao; Dong, Huanli; Hu, Wenping; Bo, Zhishan

    2014-06-01

    Four novel conjugated polymers (P1-4) with 9,10-disubstituted phenanthrene (PhA) as the donor unit and 5,6-bis(octyloxy)benzothiadiazole as the acceptor unit are synthesized and characterized. These polymers are of medium bandgaps (2.0 eV), low-lying HOMO energy levels (below -5.3 eV), and high hole mobilities (in the range of 3.6 × 10(-3) to 0.02 cm(2) V(-1) s(-1) ). Bulk heterojunction (BHJ) polymer solar cells (PSCs) with P1-4:PC71 BM blends as the active layer and an alcohol-soluble fullerene derivative (FN-C60) as the interfacial layer between the active layer and cathode give the best power conversion efficiency (PCE) of 4.24%, indicating that 9,10-disubstituted PhA are potential donor materials for high-efficiency BHJ PSCs.

  8. High-capacity thick cathode with a porous aluminum current collector for lithium secondary batteries

    Science.gov (United States)

    Abe, Hidetoshi; Kubota, Masaaki; Nemoto, Miyu; Masuda, Yosuke; Tanaka, Yuichi; Munakata, Hirokazu; Kanamura, Kiyoshi

    2016-12-01

    A high-capacity thick cathode has been studied as one of ways to improve the energy density of lithium secondary batteries. In this study, the LiFePO4 cathode with a capacity per unit area of 8.4 m Ah cm-2 corresponding to four times the capacity of conventional cathodes has been developed using a three-dimensional porous aluminum current collector called "FUSPOROUS". This unique current collector enables the smooth transfer of electrons and Li+-ions through the thick cathode, resulting in a good rate capability (discharge capacity ratio of 1.0 C/0.2 C = 0.980) and a high charge-discharge cycle performance (80% of the initial capacity at 2000th cycle) even though the electrode thickness is 400 μm. To take practical advantage of the developed thick cathode, conceptual designs for a 10-Ah class cell were also carried out using graphite and lithium-metal anodes.

  9. Mechanical properties of regular porous biomaterials made from truncated cube repeating unit cells: Analytical solutions and computational models.

    Science.gov (United States)

    Hedayati, R; Sadighi, M; Mohammadi-Aghdam, M; Zadpoor, A A

    2016-03-01

    Additive manufacturing (AM) has enabled fabrication of open-cell porous biomaterials based on repeating unit cells. The micro-architecture of the porous biomaterials and, thus, their physical properties could then be precisely controlled. Due to their many favorable properties, porous biomaterials manufactured using AM are considered as promising candidates for bone substitution as well as for several other applications in orthopedic surgery. The mechanical properties of such porous structures including static and fatigue properties are shown to be strongly dependent on the type of the repeating unit cell based on which the porous biomaterial is built. In this paper, we study the mechanical properties of porous biomaterials made from a relatively new unit cell, namely truncated cube. We present analytical solutions that relate the dimensions of the repeating unit cell to the elastic modulus, Poisson's ratio, yield stress, and buckling load of those porous structures. We also performed finite element modeling to predict the mechanical properties of the porous structures. The analytical solution and computational results were found to be in agreement with each other. The mechanical properties estimated using both the analytical and computational techniques were somewhat higher than the experimental data reported in one of our recent studies on selective laser melted Ti-6Al-4V porous biomaterials. In addition to porosity, the elastic modulus and Poisson's ratio of the porous structures were found to be strongly dependent on the ratio of the length of the inclined struts to that of the uninclined (i.e. vertical or horizontal) struts, α, in the truncated cube unit cell. The geometry of the truncated cube unit cell approaches the octahedral and cube unit cells when α respectively approaches zero and infinity. Consistent with those geometrical observations, the analytical solutions presented in this study approached those of the octahedral and cube unit cells when

  10. The Application of Load-cell Technique in the Study of Armour Unit Responses to Impact Loads Tests

    DEFF Research Database (Denmark)

    Burcharth, H. F.; Liu, Z.

    1995-01-01

    The slender, complex types of armour units, such as Tetrapods and Dolosse are widely used for rubble mound breakwaters. Many of the recent failures of such structures were caused by unforeseen early breakage of the units, thus revealing an in balance between the strength (structural integrity....... slender armour units can be studied. by load-cell technique. Moreover, the paper presents DoJos design diagrams for the prediction of both breakage and hydraulic stability...

  11. The Application of Load-cell Technique in the Study of Armour Unit Responses to Impact Loads

    DEFF Research Database (Denmark)

    Burcharth, H. F.; Liu, Zhou

    1994-01-01

    The slender, complex types of armour units, such as Tetrapods and Dolosse are widely used for rubble mound breakwaters. Many of the recent failures of such structures were caused by unforeseen early breakage of the units, thus revealing an inbalance between the strength (structural integrity...... on slender armour units can be studied by load-cell technique. Moreover, the paper presents Dolos design diagrams for the prediction of both breakage and hydraulic stability....

  12. National Assessment of Oil and Gas Project - Wind River Basin Province (035) Assessment Units Quarter-Mile Cells

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Cell maps for each oil and gas assessment unit were created by the USGS to illustrate the degree of exploration, type of production, and distribution of production...

  13. Failure mechanisms of additively manufactured porous biomaterials: Effects of porosity and type of unit cell.

    Science.gov (United States)

    Kadkhodapour, J; Montazerian, H; Darabi, A Ch; Anaraki, A P; Ahmadi, S M; Zadpoor, A A; Schmauder, S

    2015-10-01

    Since the advent of additive manufacturing techniques, regular porous biomaterials have emerged as promising candidates for tissue engineering scaffolds owing to their controllable pore architecture and feasibility in producing scaffolds from a variety of biomaterials. The architecture of scaffolds could be designed to achieve similar mechanical properties as in the host bone tissue, thereby avoiding issues such as stress shielding in bone replacement procedure. In this paper, the deformation and failure mechanisms of porous titanium (Ti6Al4V) biomaterials manufactured by selective laser melting from two different types of repeating unit cells, namely cubic and diamond lattice structures, with four different porosities are studied. The mechanical behavior of the above-mentioned porous biomaterials was studied using finite element models. The computational results were compared with the experimental findings from a previous study of ours. The Johnson-Cook plasticity and damage model was implemented in the finite element models to simulate the failure of the additively manufactured scaffolds under compression. The computationally predicted stress-strain curves were compared with the experimental ones. The computational models incorporating the Johnson-Cook damage model could predict the plateau stress and maximum stress at the first peak with less than 18% error. Moreover, the computationally predicted deformation modes were in good agreement with the results of scaling law analysis. A layer-by-layer failure mechanism was found for the stretch-dominated structures, i.e. structures made from the cubic unit cell, while the failure of the bending-dominated structures, i.e. structures made from the diamond unit cells, was accompanied by the shearing bands of 45°.

  14. Identified metabolic signature for assessing red blood cell unit quality is associated with endothelial damage markers and clinical outcomes

    DEFF Research Database (Denmark)

    Bordbar, Aarash; Johansson, Pär I.; Paglia, Giuseppe;

    2016-01-01

    BACKGROUND: There has been interest in determining whether older red blood cell (RBC) units have negative clinical effects. Numerous observational studies have shown that older RBC units are an independent factor for patient mortality. However, recently published randomized clinical trials have...

  15. High quality-factor fano metasurface comprising a single resonator unit cell

    Energy Technology Data Exchange (ETDEWEB)

    Sinclair, Michael B.; Warne, Larry K.; Basilio, Lorena I.; Langston, William L.; Campione, Salvatore; Brener, Igal; Liu, Sheng

    2017-06-20

    A new monolithic resonator metasurface design achieves ultra-high Q-factors while using only one resonator per unit cell. The metasurface relies on breaking the symmetry of otherwise highly symmetric resonators to induce intra-resonator mixing of bright and dark modes (rather than inter-resonator couplings), and is scalable from the near-infrared to radio frequencies and can be easily implemented in dielectric materials. The resulting high-quality-factor Fano metasurface can be used in many sensing, spectral filtering, and modulation applications.

  16. Unit Cell Structure of Crystal Polytypes in InAs and InSb Nanowires

    DEFF Research Database (Denmark)

    Kriegner, Dominik; Panse, Christian; Mandl, Bernhard

    2011-01-01

    , wurtzite, and 4H polytypes for InAs and InSb nanowires, using X-ray diffraction and transmission electron microscopy. The results are compared to density functional theory calculations. Experiment and theory show that the occurrence of hexagonal bilayers tends to stretch the distances of atomic layers...... parallel to the c axis and to reduce the in-plane distances compared to those in zinc blende. The change of the lattice parameters scales linearly with the hexagonality of the polytype, defined as the fraction of bilayers with hexagonal character within one unit cell....

  17. Unit cell modeling in support of interim performance assessment for low level tank waste disposal

    Energy Technology Data Exchange (ETDEWEB)

    Kline, N.W., Westinghouse Hanford

    1996-08-01

    A unit cell model is used to simulate the base analysis case and related sensitivity cases for the interim performance assessment of low level tank waste disposal. Simulation case results are summarized in terms of fractional contaminant release rates to the vadose zone and to the water table at the unconfined aquifer. Results suggest that the crushed glass water conditioning layer at the top of the facility and the chemical retardation pad at the bottom of the facility can be important components of the facility. Results also suggest that the release rates to the water table are dominated by the release rate from the waste form.

  18. Ocean Sediment Thickness Contours

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Ocean sediment thickness contours in 200 meter intervals for water depths ranging from 0 - 18,000 meters. These contours were derived from a global sediment...

  19. Origami of thick panels

    Science.gov (United States)

    Chen, Yan; Peng, Rui; You, Zhong

    2015-07-01

    Origami patterns, including the rigid origami patterns in which flat inflexible sheets are joined by creases, are primarily created for zero-thickness sheets. In order to apply them to fold structures such as roofs, solar panels, and space mirrors, for which thickness cannot be disregarded, various methods have been suggested. However, they generally involve adding materials to or offsetting panels away from the idealized sheet without altering the kinematic model used to simulate folding. We develop a comprehensive kinematic synthesis for rigid origami of thick panels that differs from the existing kinematic model but is capable of reproducing motions identical to that of zero-thickness origami. The approach, proven to be effective for typical origami, can be readily applied to fold real engineering structures.

  20. Auxiliary power unit based on a solid oxide fuel cell and fuelled with diesel

    Science.gov (United States)

    Lawrence, Jeremy; Boltze, Matthias

    An auxiliary power unit (APU) is presented that is fuelled with diesel, thermally self-sustaining, and based on a solid oxide fuel cell (SOFC). The APU is rated at 1 kW electrical, and can generate electrical power after a 3 h warm-up phase. System features include a "dry" catalytic partial oxidation (CPOX) diesel reformer, a 30 cell SOFC stack with an open cathode, and a porous-media afterburner. The APU does not require a supply of external water. The SOFC stack is an outcome of a development partnership with H.C. Starck GmbH and Fraunhofer IKTS, and is discussed in detail in an accompanying paper.

  1. Root cause analysis of the degradation in a unitized regenerative fuel cell

    Science.gov (United States)

    Bhosale, Amit C.; Meenakshi, S.; Ghosh, Prakash C.

    2017-03-01

    The present study emphasizes the possible modes of failure of a unitized regenerative fuel cell (URFC) when operated in fuel cell as well as in electrolysis mode at different temperatures viz. 30 °C and 60 °C. The carbon based catalyst (Pt/C) and diffusion layers are used to characterize the degradation of the URFCs. The electrolysis mode of operation is found to dominate the root cause of failure with increase in temperature. Agglomeration and loss of catalyst along with delamination of electrode from membrane are observed. Membrane degradation owing to it's structural as well as chemical damage is seen to be prominent at higher temperature. Characterization techniques such as SEM, TEM and ICP-AES confirm the study showcasing the effect.

  2. Optimizing energy management of decentralized photovoltaic. Fuel cell - direct storage - power supply units

    Energy Technology Data Exchange (ETDEWEB)

    Bocklisch, Thilo; Schufft, Wolfgang; Bocklisch, Steffen [Chemnitz Univ. of Technology (TUC) (Germany)

    2010-07-01

    This paper presents a new optimizing energy management concept for decentralized power supply units. Main goal is the coordinated utilization of dynamically controllable combined-heat-and-power-plants (e.g. fuel cell cogeneration plants) and electrochemical direct storages (e.g. future electric car batteries) for the active balancing of fluctuating renewable energy generation (e.g. building integrated photovoltaics) and fluctuation electricity consumption. The self-utilization and partial storage of renewable energy helps to stabilize the grid in a ''bottom-up'' approach. The new energy mangement concept features a three-layer control structure, which aims for the optimization of the power flows, minimizing the fuel consumption and the dynamic stress imposed onto the fuel cell. (orig.)

  3. Spherical TiO2 aggregates with different building units for dye-sensitized solar cells.

    Science.gov (United States)

    Liu, Zhaohui; Su, Xunjia; Hou, Genliang; Bi, Song; Xiao, Zhou; Jia, Haipeng

    2013-09-07

    Tailoring the architectures of spherical TiO2 aggregates is crucial to obtain superior photovoltaic properties and promote their application in dye-sensitized solar cells (DSSCs). Herein, we synthesized spherical TiO2 aggregates using different building units, including nanocrystallites, nanorods, nanosheets, and nanotubes, via a hydrothermal method, and studied the effect of the building units on the performances of DSSCs. The aggregates assembled by uniform nanosheet and nanotube building units were synthesized with the use of spherical TiO2 nanorod aggregates as titanium sources in an alkaline hydrothermal reaction. Compared with TiO2 nanoparticles, the spherical TiO2 aggregates possess higher surface area, more efficient light scattering ability, and better electron transport properties. Among the four types of spherical TiO2 aggregates; the nanorod, nanotube, and nanosheet aggregates demonstrate better electron transport properties than the nanocrystallite aggregates; the nanotube and nanosheet aggregates exhibit more efficient light scattering than the nanocrystallite and nanorod aggregates; and the nanotube aggregates show the highest surface area. Thus the DSSC based on nanotube aggregates exhibited the highest energy conversion efficiency of 7.48%, which is 16.0%, 9.7%, and 19.5% higher than those of the DSSCs based on the nanosheet, nanorod, and nanocrystallite aggregates, respectively.

  4. Unit cell-based computer-aided manufacturing system for tissue engineering.

    Science.gov (United States)

    Kang, Hyun-Wook; Park, Jeong Hun; Kang, Tae-Yun; Seol, Young-Joon; Cho, Dong-Woo

    2012-03-01

    Scaffolds play an important role in the regeneration of artificial tissues or organs. A scaffold is a porous structure with a micro-scale inner architecture in the range of several to several hundreds of micrometers. Therefore, computer-aided construction of scaffolds should provide sophisticated functionality for porous structure design and a tool path generation strategy that can achieve micro-scale architecture. In this study, a new unit cell-based computer-aided manufacturing (CAM) system was developed for the automated design and fabrication of a porous structure with micro-scale inner architecture that can be applied to composite tissue regeneration. The CAM system was developed by first defining a data structure for the computing process of a unit cell representing a single pore structure. Next, an algorithm and software were developed and applied to construct porous structures with a single or multiple pore design using solid freeform fabrication technology and a 3D tooth/spine computer-aided design model. We showed that this system is quite feasible for the design and fabrication of a scaffold for tissue engineering.

  5. Imaging the impact on cuprate superconductivity of varying the interatomic distances within individual crystal unit cells.

    Science.gov (United States)

    Slezak, J A; Lee, Jinho; Wang, M; McElroy, K; Fujita, K; Andersen, B M; Hirschfeld, P J; Eisaki, H; Uchida, S; Davis, J C

    2008-03-04

    Many theoretical models of high-temperature superconductivity focus only on the doping dependence of the CuO(2)-plane electronic structure. However, such models are manifestly insufficient to explain the strong variations in superconducting critical temperature, T(c), among cuprates that have identical hole density but are crystallographically different outside of the CuO(2) plane. A key challenge, therefore, has been to identify a predominant out-of-plane influence controlling the superconductivity, with much attention focusing on the distance d(A) between the apical oxygen and the planar copper atom. Here we report direct determination of how variations in interatomic distances within individual crystalline unit cells affect the superconducting energy-gap maximum Delta of Bi(2)Sr(2)CaCu(2)O(8+delta). In this material, quasiperiodic variations of unit cell geometry occur in the form of a bulk crystalline "supermodulation." Within each supermodulation period, we find approximately 9 +/- 1% cosinusoidal variation in local Delta that is anticorrelated with the associated d(A) variations. Furthermore, we show that phenomenological consistency would exist between these effects and the random Delta variations found near dopant atoms if the primary effect of the interstitial dopant atom is to displace the apical oxygen so as to diminish d(A) or tilt the CuO(5) pyramid. Thus, we reveal a strong, nonrandom out-of-plane effect on cuprate superconductivity at atomic scale.

  6. Intra-unit-cell nematic charge order in the titanium-oxypnictide family of superconductors

    Science.gov (United States)

    Frandsen, Benjamin A.; Bozin, Emil S.; Hu, Hefei; Zhu, Yimei; Nozaki, Yasumasa; Kageyama, Hiroshi; Uemura, Yasutomo J.; Yin, Wei-Guo; Billinge, Simon J. L.

    2014-12-01

    Understanding the role played by broken-symmetry states such as charge, spin and orbital orders in the mechanism of emergent properties, such as high-temperature superconductivity, is a major current topic in materials research. That the order may be within one unit cell, such as nematic, was only recently considered theoretically, but its observation in the iron-pnictide and doped cuprate superconductors places it at the forefront of current research. Here, we show that the recently discovered BaTi2Sb2O superconductor and its parent compound BaTi2As2O form a symmetry-breaking nematic ground state that can be naturally explained as an intra-unit-cell nematic charge order with d-wave symmetry, pointing to the ubiquity of the phenomenon. These findings, together with the key structural features in these materials being intermediate between the cuprate and iron-pnictide high-temperature superconducting materials, render the titanium oxypnictides an important new material system to understand the nature of nematic order and its relationship to superconductivity.

  7. Fuel cell collaboration in the United States. A report to the Danish Partnership for Hydrogen and Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    2011-08-15

    The purpose of this report is to provide members of the Danish Partnership for Hydrogen and Fuel Cells with information regarding collaborative opportunities in the United States. The report is designed to provide an overview of key issues and activities and to provide guidance on strategies for finding U.S. research and commercial partners and gaining access to the U.S. market. Section 1 of this report provides an overview of the key drivers of policy at the federal and state government levels regarding hydrogen and fuel cell technologies and provides a perspective of the U.S. industry and key players. It also suggests three general pathways for accessing U.S. opportunities: enhancing visibility; developing vendor relationships; and establishing a formal presence in the U.S. The next sections summarize focus areas for commercial and research activity that currently are of the greatest interest in the U.S. Section 2 describes major programs within the federal government and national laboratories, and discusses various methods for identifying R and D funding opportunities, with an overview of federal acquisition regulations. Section 3 reviews the efforts of several state governments engaging the fuel cell industry as an economic driver and presents an overview of acquisition at the state level. Section 4 discusses university research and development (R and D) and university-industry partnerships. There are 12 appendices attached to the report. These appendices provide more detailed information regarding the key federal government agencies involved in fuel cells and hydrogen, state-specific policies and activities, national laboratories and universities, and other information regarding the fuel cell and hydrogen industry in the U.S. (Author)

  8. Micro-droplets lubrication film thickness dynamics

    Science.gov (United States)

    Huerre, Axel; Theodoly, Olivier; Cantat, Isabelle; Leshansky, Alexander; Valignat, Marie-Pierre; Jullien, Marie-Caroline; MMN Team; LAI Team; IPR Team; Department of Chemical Engineering Team

    2014-11-01

    The motion of droplets or bubbles in confined geometries has been extensively studied; showing an intrinsic relationship between the lubrication film thickness and the droplet velocity. When capillary forces dominate, the lubrication film thickness evolves non linearly with the capillary number due to viscous dissipation between meniscus and wall. However, this film may become thin enough that intermolecular forces come into play and affect classical scalings. We report here the first experimental evidence of the disjoining pressure effect on confined droplets by measuring droplet lubrication film thicknesses in a microfluidic Hele-Shaw cell. We find and characterize two distinct dynamical regimes, dominated respectively by capillary and intermolecular forces. In the former case rolling boundary conditions at the interface are evidenced through film thickness dynamics, interface velocity measurement and film thickness profile.

  9. STREAMLINED APPROACH FOR ENVIRONMENTAL RESTORATION PLAN FOR CORRECTIVE ACTION UNIT 116: AREA 25 TEST CELL C FACILITYNEVADA TEST SITE, NEVADA

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    This Streamlined Approach for Environmental Restoration Plan identifies the activities required for the closure of Corrective Action Unit 116, Area 25 Test Cell C Facility. The Test Cell C Facility is located in Area 25 of the Nevada Test Site approximately 25 miles northwest of Mercury, Nevada.

  10. Impact of the irregular microgeometry of polyurethane foam on the macroscopic acoustic behavior predicted by a unit-cell model.

    Science.gov (United States)

    Doutres, O; Ouisse, M; Atalla, N; Ichchou, M

    2014-10-01

    This paper deals with the prediction of the macroscopic sound absorption behavior of highly porous polyurethane foams using two unit-cell microstructure-based models recently developed by Doutres, Atalla, and Dong [J. Appl. Phys. 110, 064901 (2011); J. Appl. Phys. 113, 054901 (2013)]. In these models, the porous material is idealized as a packing of a tetrakaidecahedra unit-cell representative of the disordered network that constitutes the porous frame. The non-acoustic parameters involved in the classical Johnson-Champoux-Allard model (i.e., porosity, airflow resistivity, tortuosity, etc.) are derived from characteristic properties of the unit-cell and semi-empirical relationships. A global sensitivity analysis is performed on these two models in order to investigate how the variability associated with the measured unit-cell characteristics affects the models outputs. This allows identification of the possible limitations of a unit-cell micro-macro approach due to microstructure irregularity. The sensitivity analysis mainly shows that for moderately and highly reticulated polyurethane foams, the strut length parameter is the key parameter since it greatly impacts three important non-acoustic parameters and causes large uncertainty on the sound absorption coefficient even if its measurement variability is moderate. For foams with a slight inhomogeneity and anisotropy, a micro-macro model associated to cell size measurements should be preferred.

  11. Techno-economic analysis of fuel cell auxiliary power units as alternative to idling

    Science.gov (United States)

    Jain, Semant; Chen, Hsieh-Yeh; Schwank, Johannes

    This paper presents a techno-economic analysis of fuel-cell-based auxiliary power units (APUs), with emphasis on applications in the trucking industry and the military. The APU system is intended to reduce the need for discretionary idling of diesel engines or gas turbines. The analysis considers the options for on-board fuel processing of diesel and compares the two leading fuel cell contenders for automotive APU applications: proton exchange membrane fuel cell and solid oxide fuel cell. As options for on-board diesel reforming, partial oxidation and auto-thermal reforming are considered. Finally, using estimated and projected efficiency data, fuel consumption patterns, capital investment, and operating costs of fuel-cell APUs, an economic evaluation of diesel-based APUs is presented, with emphasis on break-even periods as a function of fuel cost, investment cost, idling time, and idling efficiency. The analysis shows that within the range of parameters studied, there are many conditions where deployment of an SOFC-based APU is economically viable. Our analysis indicates that at an APU system cost of 100 kW -1, the economic break-even period is within 1 year for almost the entire range of conditions. At 500 kW -1 investment cost, a 2-year break-even period is possible except for the lowest end of the fuel consumption range considered. However, if the APU investment cost is 3000 kW -1, break-even would only be possible at the highest fuel consumption scenarios. For Abram tanks, even at typical land delivered fuel costs, a 2-year break-even period is possible for APU investment costs as high as 1100 kW -1.

  12. Algorithm and program for precise determination of unit-cell parameters of single crystal taking into account the sample eccentricity

    Science.gov (United States)

    Dudka, A. P.; Smirnova, E. S.; Verin, I. A.; Bolotina, N. B.

    2017-07-01

    A technique has been developed to refine the unit-cell parameters of single crystals with minimization of the influence of instrumental errors on the result. The corresponding computational procedure HuberUB is added to the software package of Huber-5042 diffractometer with a point detector and closedcycle helium cryostat Displex DE-202. The parameters of unit cell, its orientation, the goniometer zero angles, the sample eccentricity, the distances in the goniometer, and the radiation wavelength were refined by the nonlinear least-squares method, which allows imposition of constraints on the unit-cell parameters, depending on the crystal symmetry. The technique is approved on a LuB12 single crystal. The unit-cell parameters are determined in a temperature range of 20-295 K, with an absolute error not larger than 0.0004 Å (the relative error is of 5 × 10-5). The estimates of the unit-cell parameters obtained by the proposed method are evidenced to be unbiased. Some specific features of the behavior of parameters in the ranges of 120-140 and 20-50 K are revealed, which correlate with the anomalies of the physical properties of the crystal.

  13. Prognosis of Allogeneic Haematopoietic Stem Cell Recipients Admitted to the Intensive Care Unit

    DEFF Research Database (Denmark)

    Lindgaard, Sidsel Christy; Nielsen, Jonas; Lindmark, Anders

    2016-01-01

    BACKGROUND: Allogeneic haematopoietic stem cell transplantation (HSCT) is a procedure with inherent complications and intensive care may be necessary. We evaluated the short- and long-term outcomes of the HSCT recipients requiring admission to the intensive care unit (ICU). METHODS: We...... ventilation had a statistically significant effect on in-ICU (p = 0.02), 6-month (p = 0.049) and 1-year (p = 0.014) mortality. Renal replacement therapy also had a statistically significant effect on in-hospital (p = 0.038) and 6-month (p = 0.026) mortality. Short ICU admissions, i.e. ... to the ICU was confirmed in our study. Mechanical ventilation, renal replacement therapy and an ICU admission of ≥10 days were each risk factors for mortality in the first year after ICU admission....

  14. A diesel fuel processor for fuel-cell-based auxiliary power unit applications

    Science.gov (United States)

    Samsun, Remzi Can; Krekel, Daniel; Pasel, Joachim; Prawitz, Matthias; Peters, Ralf; Stolten, Detlef

    2017-07-01

    Producing a hydrogen-rich gas from diesel fuel enables the efficient generation of electricity in a fuel-cell-based auxiliary power unit. In recent years, significant progress has been achieved in diesel reforming. One issue encountered is the stable operation of water-gas shift reactors with real reformates. A new fuel processor is developed using a commercial shift catalyst. The system is operated using optimized start-up and shut-down strategies. Experiments with diesel and kerosene fuels show slight performance drops in the shift reactor during continuous operation for 100 h. CO concentrations much lower than the target value are achieved during system operation in auxiliary power unit mode at partial loads of up to 60%. The regeneration leads to full recovery of the shift activity. Finally, a new operation strategy is developed whereby the gas hourly space velocity of the shift stages is re-designed. This strategy is validated using different diesel and kerosene fuels, showing a maximum CO concentration of 1.5% at the fuel processor outlet under extreme conditions, which can be tolerated by a high-temperature PEFC. The proposed operation strategy solves the issue of strong performance drop in the shift reactor and makes this technology available for reducing emissions in the transportation sector.

  15. The Ag shell thickness effect of Au@Ag@SiO2 core-shell nanoparticles on the optoelectronic performance of dye sensitized solar cells.

    Science.gov (United States)

    Wang, Yang; Zhai, Jin; Song, Yanlin; He, Ling

    2016-02-07

    To tailor the Au@Ag@SiO2 LSPR effect by varying the Ag shell thickness, the Au@Ag@SiO2 core-ultra-thin shell nanoparticles are fabricated and introduced into DSSC for improving light harvesting and decreasing the recombination of photo-carriers. The Au@Ag@SiO2 electrode exhibits a photo-conversion efficiency of 23.42% (486.7 nm, 10 mW cm(-2)).

  16. STEM tomography for thick biological specimens

    Energy Technology Data Exchange (ETDEWEB)

    Aoyama, Kazuhiro [FEI Company Japan Ltd., Application Laboratory, NSS-II Building, 2-13-34 Kohnan, Minato-ku, Tokyo 108-0075 (Japan)], E-mail: kazuhiro.aoyama@fei.com; Takagi, Tomoko [FEI Company Japan Ltd., Application Laboratory, NSS-II Building, 2-13-34 Kohnan, Minato-ku, Tokyo 108-0075 (Japan); Laboratory of Electron Microscopy, Japan Women' s University, 2-8-1 Mejirodai, Bunkyo-ku, Tokyo 112-8681 (Japan); Hirase, Ai; Miyazawa, Atsuo [Bio-multisome Research Team, RIKEN SPring-8 Center, Harima Institute, 1-1-1 Kouto, Sayo, Hyogo 679-5148 (Japan); CREST, JST (Japan)

    2008-12-15

    Scanning transmission electron microscopy (STEM) tomography was applied to biological specimens such as yeast cells, HEK293 cells and primary culture neurons. These cells, which were embedded in a resin, were cut into 1-{mu}m-thick sections. STEM tomography offers several important advantages including: (1) it is effective even for thick specimens, (2) 'dynamic focusing', (3) ease of using an annular dark field (ADF) mode and (4) linear contrasts. It has become evident that STEM tomography offers significant advantages for the observation of thick specimens. By employing STEM tomography, even a 1-{mu}m-thick specimen (which is difficult to observe by conventional transmission electron microscopy (TEM)) was successfully analyzed in three dimensions. The specimen was tilted up to 73 deg. during data acquisition. At a large tilt angle, the specimen thicknesses increase dramatically. In order to observe such thick specimens, we introduced a special small condenser aperture that reduces the collection angle of the STEM probe. The specimen damage caused by the convergent electron beam was expected to be the most serious problem; however, the damage in STEM was actually smaller than that in TEM. In this study, the irradiation damage caused by TEM- and STEM-tomography in biological specimens was quantitatively compared.

  17. Fuel cell system including a unit for electrical isolation of a fuel cell stack from a manifold assembly and method therefor

    Science.gov (United States)

    Kelley; Dana A. , Farooque; Mohammad , Davis; Keith

    2007-10-02

    A fuel cell system with improved electrical isolation having a fuel cell stack with a positive potential end and a negative potential, a manifold for use in coupling gases to and from a face of the fuel cell stack, an electrical isolating assembly for electrically isolating the manifold from the stack, and a unit for adjusting an electrical potential of the manifold such as to impede the flow of electrolyte from the stack across the isolating assembly.

  18. Bidirectional relationship of mast cells-neurovascular unit communication in neuroinflammation and its involvement in POCD.

    Science.gov (United States)

    Li, Nana; Zhang, Xiang; Dong, Hongquan; Hu, Youli; Qian, Yanning

    2017-03-30

    Postoperative cognitive dysfunction (POCD) has been hypothesized to be mediated by surgery-induced neuroinflammation, which is also a key element in the pathobiology of neurodegenerative diseases, stroke, and neuropsychiatric disorders. There is extensive communication between the immune system and the central nervous system (CNS). Inflammation resulting from activation of the innate immune system cells in the periphery can impact central nervous system behaviors, such as cognitive performance. Mast cells (MCs), as the"first responders" in the CNS, can initiate, amplify, and prolong other immune and nervous responses upon activation. In addition, MCs and their secreted mediators modulate inflammatory processes in multiple CNS pathologies and can thereby either contribute to neurological damage or confer neuroprotection. Neuroinflammation has been considered to be linked to neurovascular dysfunction in several neurological disorders. This review will provide a brief overview of the bidirectional relationship of MCs-neurovascular unit communication in neuroinflammation and its involvement in POCD, providing a new and unique therapeutic target for the adjuvant treatment of POCD.

  19. Two-Dimensional Simulation of Mass Transfer in Unitized Regenerative Fuel Cells under Operation Mode Switching

    Directory of Open Access Journals (Sweden)

    Lulu Wang

    2016-01-01

    Full Text Available A two-dimensional, single-phase, isothermal, multicomponent, transient model is built to investigate the transport phenomena in unitized regenerative fuel cells (URFCs under the condition of switching from the fuel cell (FC mode to the water electrolysis (WE mode. The model is coupled with an electrochemical reaction. The proton exchange membrane (PEM is selected as the solid electrolyte of the URFC. The work is motivated by the need to elucidate the complex mass transfer and electrochemical process under operation mode switching in order to improve the performance of PEM URFC. A set of governing equations, including conservation of mass, momentum, species, and charge, are considered. These equations are solved by the finite element method. The simulation results indicate the distributions of hydrogen, oxygen, water mass fraction, and electrolyte potential response to the transient phenomena via saltation under operation mode switching. The hydrogen mass fraction gradients are smaller than the oxygen mass fraction gradients. The average mass fractions of the reactants (oxygen and hydrogen and product (water exhibit evident differences between each layer in the steady state of the FC mode. By contrast, the average mass fractions of the reactant (water and products (oxygen and hydrogen exhibit only slight differences between each layer in the steady state of the WE mode. Under either the FC mode or the WE mode, the duration of the transient state is only approximately 0.2 s.

  20. Additively Manufactured Open-Cell Porous Biomaterials Made from Six Different Space-Filling Unit Cells: The Mechanical and Morphological Properties

    Directory of Open Access Journals (Sweden)

    Seyed Mohammad Ahmadi

    2015-04-01

    Full Text Available It is known that the mechanical properties of bone-mimicking porous biomaterials are a function of the morphological properties of the porous structure, including the configuration and size of the repeating unit cell from which they are made. However, the literature on this topic is limited, primarily because of the challenge in fabricating porous biomaterials with arbitrarily complex morphological designs. In the present work, we studied the relationship between relative density (RD of porous Ti6Al4V EFI alloy and five compressive properties of the material, namely elastic gradient or modulus (Es20–70, first maximum stress, plateau stress, yield stress, and energy absorption. Porous structures with different RD and six different unit cell configurations (cubic (C, diamond (D, truncated cube (TC, truncated cuboctahedron (TCO, rhombic dodecahedron (RD, and rhombicuboctahedron (RCO were fabricated using selective laser melting. Each of the compressive properties increased with increase in RD, the relationship being of a power law type. Clear trends were seen in the influence of unit cell configuration and porosity on each of the compressive properties. For example, in terms of Es20–70, the structures may be divided into two groups: those that are stiff (comprising those made using C, TC, TCO, and RCO unit cell and those that are compliant (comprising those made using D and RD unit cell.

  1. Thicknesses of hydrogeologic units used in the hydrogeologic framework and transient ground-water flow model of the Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A digital three-dimensional hydrogeologic framework model (HFM) represents the geometry and extent of hydrogeologic units (HGUs) and major structures in the Death...

  2. Thicknesses of hydrogeologic units used in the hydrogeologic framework and transient ground-water flow model of the Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A digital three-dimensional hydrogeologic framework model (HFM) represents the geometry and extent of hydrogeologic units (HGUs) and major structures in the Death...

  3. Inhibition of Autophagy Enhances Curcumin United light irradiation-induced Oxidative Stress and Tumor Growth Suppression in Human Melanoma Cells

    Science.gov (United States)

    Niu, Tianhui; Tian, Yan; Mei, Zhusong; Guo, Guangjin

    2016-01-01

    Malignant melanoma is the most aggressive form of skin carcinoma, which possesses fast propagating and highly invasive characteristics. Curcumin is a natural phenol compound that has various biological activities, such as anti-proliferative and apoptosis-accelerating impacts on tumor cells. Unfortunately, the therapeutical activities of Cur are severely hindered due to its extremely low bioavailability. In this study, a cooperative therapy of low concentration Cur combined with red united blue light irradiation was performed to inspect the synergistic effects on the apoptosis, proliferation and autophagy in human melanoma A375 cell. The results showed that red united blue light irradiation efficaciously synergized with Cur to trigger oxidative stress-mediated cell death, induce apoptosis and inhibit cell proliferation. Meanwhile, Western blotting revealed that combined disposure induced the formation of autophagosomes. Conversely, inhibition of the autophagy enhanced apoptosis, obstructed cell cycle arrest and induced reversible proliferation arrest to senescence. These findings suggest that Cur combined with red united blue light irradiation could generate photochemo-preventive effects via enhancing apoptosis and triggering autophagy, and pharmacological inhibition of autophagy convert reversible arrested cells to senescence, therefore reducing the possibility that damaged cells might escape programmed death. PMID:27502897

  4. Thickness-dependent coherent phonon frequency in ultrathin FeSe/SrTiO3 films

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Shuolong [SLAC National Accelerator Lab., Menlo Park, CA (United States); Stanford Univ., Stanford, CA (United States); Sobota, Jonathan A. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Leuenberger, Dominik [SLAC National Accelerator Lab., Menlo Park, CA (United States); Stanford Univ., Stanford, CA (United States); Kemper, Alexander F. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Lee, James J. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Stanford Univ., Stanford, CA (United States); Schmitt, Felix T. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Stanford Univ., Stanford, CA (United States); Li, Wei [SLAC National Accelerator Lab., Menlo Park, CA (United States); Stanford Univ., Stanford, CA (United States); Moore, Rob G. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Stanford Univ., Stanford, CA (United States); Kirchmann, Patrick S. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Shen, Zhi -Xun [SLAC National Accelerator Lab., Menlo Park, CA (United States); Stanford Univ., Stanford, CA (United States)

    2015-06-01

    Ultrathin FeSe films grown on SrTiO3 substrates are a recent milestone in atomic material engineering due to their important role in understanding unconventional superconductivity in Fe-based materials. By using femtosecond time- and angle-resolved photoelectron spectroscopy, we study phonon frequencies in ultrathin FeSe/SrTiO3 films grown by molecular beam epitaxy. After optical excitation, we observe periodic modulations of the photoelectron spectrum as a function of pump–probe delay for 1-unit-cell, 3-unit-cell, and 60-unit-cell thick FeSe films. The frequencies of the coherent intensity oscillations increase from 5.00 ± 0.02 to 5.25 ± 0.02 THz with increasing film thickness. By comparing with previous works, we attribute this mode to the Se A1g phonon. The dominant mechanism for the phonon softening in 1-unit-cell thick FeSe films is a substrate-induced lattice strain. Results demonstrate an abrupt phonon renormalization due to a lattice mismatch between the ultrathin film and the substrate.

  5. Growth Factor Independence-1 (Gfi1) Is Required for Pancreatic Acinar Unit Formation and Centroacinar Cell Differentiation

    DEFF Research Database (Denmark)

    Qu, Xiaoling; Nyeng, Pia; Xiao, Fan

    2015-01-01

    BACKGROUND & AIMS: The genetic specification of the compartmentalized pancreatic acinar/centroacinar unit is poorly understood. Growth factor independence-1 (Gfi1) is a zinc finger transcriptional repressor that regulates hematopoietic stem cell maintenance, pre-T-cell differentiation, formation...... of pancreatic acinar cells as well as the centroacinar cells (CACs) in Gfi1(-/-) mice when compared with wild-type littermates. Pancreatic endocrine differentiation, islet architecture, and function were unaffected. Organ domain patterning and the formation of ductal cells occurred normally during the murine...... of granulocytes, inner ear hair cells, and the development of secretory cell types in the intestine. As GFI1/Gfi1 is expressed in human and rodent pancreas, we characterized the potential function of Gfi1 in mouse pancreatic development. METHODS: Gfi1 knockout mice were analyzed at histological and molecular...

  6. Fabrication of interdigitated back-contact silicon heterojunction solar cells on a 53-µm-thick crystalline silicon substrate by using the optimized inkjet printing method for etching mask formation

    Science.gov (United States)

    Takagishi, Hideyuki; Noge, Hiroshi; Saito, Kimihiko; Kondo, Michio

    2017-04-01

    Inkjet-printing-based fabrication process of the interdigitated back-contact silicon heterojunction solar cells has the potential to reduce the manufacturing costs because of its low machine and material costs and its applicability to thinner fragile silicon substrates than 100 µm. In this study, ink and printing parameters were investigated to obtain the desirable fine patterns and the resultant accuracy of the linewidths was less than ±0.05 mm on a flat surface. The completed cells using inkjet-printing showed almost the same performance of that fabricated by photolithography. In addition, flexible and free-standing cell on a 53-µm-thick Si substrate has been successfully fabricated.

  7. A novel asymptotic expansion homogenization analysis for 3-D composite with relieved periodicity in the thickness direction

    KAUST Repository

    Nasution, Muhammad Ridlo Erdata

    2014-06-01

    A new asymptotic expansion homogenization analysis is proposed to analyze 3-D composite in which thermomechanical and finite thickness effects are considered. Finite thickness effect is captured by relieving periodic boundary condition at the top and bottom of unit-cell surfaces. The mathematical treatment yields that only 2-D periodicity (i.e. in in-plane directions) is taken into account. A unit-cell representing the whole thickness of 3-D composite is built to facilitate the present method. The equivalent in-plane thermomechanical properties of 3-D orthogonal interlock composites are calculated by present method, and the results are compared with those obtained by standard homogenization method (with 3-D periodicity). Young\\'s modulus and Poisson\\'s ratio obtained by present method are also compared with experiments whereby a good agreement is particularly found for the Young\\'s modulus. Localization analysis is carried out to evaluate the stress responses within the unit-cell of 3-D composites for two cases: thermal and biaxial tensile loading. Standard finite element (FE) analysis is also performed to validate the stress responses obtained by localization analysis. It is found that present method results are in a good agreement with standard FE analysis. This fact emphasizes that relieving periodicity in the thickness direction is necessary to accurately simulate the real free-traction condition in 3-D composite. © 2014 Elsevier Ltd.

  8. Effects of Dexamethasone on Satellite Cells and Tissue Engineered Skeletal Muscle Units.

    Science.gov (United States)

    Syverud, Brian C; VanDusen, Keith W; Larkin, Lisa M

    2016-03-01

    Tissue engineered skeletal muscle has potential for application as a graft source for repairing soft tissue injuries, a model for testing pharmaceuticals, and a biomechanical actuator system for soft robots. However, engineered muscle to date has not produced forces comparable to native muscle, limiting its potential for repair and for use as an in vitro model for pharmaceutical testing. In this study, we examined the trophic effects of dexamethasone (DEX), a glucocorticoid that stimulates myoblast differentiation and fusion into myotubes, on our tissue engineered three-dimensional skeletal muscle units (SMUs). Using our established SMU fabrication protocol, muscle isolates were cultured with three experimental DEX concentrations (5, 10, and 25 nM) and compared to untreated controls. Following seeding onto a laminin-coated Sylgard substrate, the administration of DEX was initiated on day 0 or day 6 in growth medium or on day 9 after the switch to differentiation medium and was sustained until the completion of SMU fabrication. During this process, total cell proliferation was measured with a BrdU assay, and myogenesis and structural advancement of muscle cells were observed through immunostaining for MyoD, myogenin, desmin, and α-actinin. After SMU formation, isometric tetanic force production was measured to quantify function. The histological and functional assessment of the SMU showed that the administration of 10 nM DEX beginning on either day 0 or day 6 yielded optimal SMUs. These optimized SMUs exhibited formation of advanced sarcomeric structure and significant increases in myotube diameter and myotube fusion index, compared with untreated controls. Additionally, the optimized SMUs matured functionally, as indicated by a fivefold rise in force production. In conclusion, we have demonstrated that the addition of DEX to our process of engineering skeletal muscle tissue improves myogenesis, advances muscle structure, and increases force production in the

  9. Progress in human embryonic stem cell research in the United States between 2001 and 2010.

    Directory of Open Access Journals (Sweden)

    Keyvan Vakili

    Full Text Available On August 9th, 2001, the federal government of the United States announced a policy restricting federal funds available for research on human embryonic stem cell (hESCs out of concern for the "vast ethical mine fields" associated with the creation of embryos for research purposes. Until the policy was repealed on March 9th, 2009, no U.S. federal funds were available for research on hESCs extracted after August 9, 2001, and only limited federal funds were available for research on a subset of hESC lines that had previously been extracted. This paper analyzes how the 2001 U.S. federal funding restrictions influenced the quantity and geography of peer-reviewed journal publications on hESC. The primary finding is that the 2001 policy did not have a significant aggregate effect on hESC research in the U.S. After a brief lag in early 2000s, U.S. hESC research maintained pace with other areas of stem cell and genetic research. The policy had several other consequences. First, it was tied to increased hESC research funding within the U.S. at the state level, leading to concentration of related activities in a relatively small number of states. Second, it stimulated increased collaborative research between US-based scientists and those in countries with flexible policies toward hESC research (including Canada, the U.K., Israel, China, Spain, and South Korea. Third, it encouraged independent hESC research in countries without restrictions.

  10. Profundidad tumoral y variables histopatológicas en el carcinoma epidermoide lingual: Estudio retrospectivo sobre 60 pacientes Tumoral thickness and histopathological parameters in the squamous cell carcinoma of tongue: A retrospective evaluation over 60 patients

    Directory of Open Access Journals (Sweden)

    JD Sánchez López

    2005-10-01

    Full Text Available I.- Introducción: La profundidad tumoral representa uno de los principales factores pronósticos del carcinoma epidermoide lingual. II.-Objetivos: Verificar si el espesor máximo tumoral se correlaciona con parámetros histopatológicos agresivos. III.-Material y Métodos: -Diseño: Estudio retrospectivo de base hospitalaria (Enero-1990 a Julio-1997 constituido por 60 pacientes afectos de carcinoma escamoso lingual. -Variables: Filiación del paciente, parámetros histopatológicos y profundidad tumoral. -Procedimientos de laboratorio. -Métodos estadísticos: Estadística descriptiva e inferencial (Método Bonferroni, C- Dunnet, Chi-cuadrado y test de Anova. IV.-Resultados: Asociación estadísticamente significativa entre Indice mitótico y profundidad tumoral (14,84;pI.-Introduction: The tumoral thickness represents one of the most ominous prognostic factors of the squamous cell carcinoma of tongue. II.-Objectives: To verify if the tumoral thickness is relationated with others aggressive histopathologic parameters. III.-Material and Methods: -Design: A hospital population retrospective study (January-1990 to July-1997 of 60 patients affected of carcinoma of tongue. -Variables: Data patients, histopathological parameters and tumoral thickness. -Laboratory procedures. -Stadistic methods: Descriptive and Inferential stadistical: Bonferroni method, C-Dunnet, Chi-square, Anova test… IV.-Results: There is a statistic association between mitotic Index and tumoral thickness (14,84; p<0,001. V.-Conclusions: Depth of invasion and mitotic Index are actually associated prognostic factors in the carcinoma epidermoid of tongue.

  11. Highly Efficient and Exceptionally Durable CO2 Photoreduction to Methanol over Freestanding Defective Single-Unit-Cell Bismuth Vanadate Layers.

    Science.gov (United States)

    Gao, Shan; Gu, Bingchuan; Jiao, Xingchen; Sun, Yongfu; Zu, Xiaolong; Yang, Fan; Zhu, Wenguang; Wang, Chengming; Feng, Zimou; Ye, Bangjiao; Xie, Yi

    2017-03-08

    Unearthing an ideal model for disclosing the role of defect sites in solar CO2 reduction remains a great challenge. Here, freestanding gram-scale single-unit-cell o-BiVO4 layers are successfully synthesized for the first time. Positron annihilation spectrometry and X-ray fluorescence unveil their distinct vanadium vacancy concentrations. Density functional calculations reveal that the introduction of vanadium vacancies brings a new defect level and higher hole concentration near Fermi level, resulting in increased photoabsorption and superior electronic conductivity. The higher surface photovoltage intensity of single-unit-cell o-BiVO4 layers with rich vanadium vacancies ensures their higher carriers separation efficiency, further confirmed by the increased carriers lifetime from 74.5 to 143.6 ns revealed by time-resolved fluorescence emission decay spectra. As a result, single-unit-cell o-BiVO4 layers with rich vanadium vacancies exhibit a high methanol formation rate up to 398.3 μmol g(-1) h(-1) and an apparent quantum efficiency of 5.96% at 350 nm, much larger than that of single-unit-cell o-BiVO4 layers with poor vanadium vacancies, and also the former's catalytic activity proceeds without deactivation even after 96 h. This highly efficient and spectrally stable CO2 photoconversion performances hold great promise for practical implementation of solar fuel production.

  12. Investigation of potential fluctuating intra-unit cell magnetic order in cuprates by μ SR

    Science.gov (United States)

    Pal, A.; Akintola, K.; Potma, M.; Ishikado, M.; Eisaki, H.; Hardy, W. N.; Bonn, D. A.; Liang, R.; Sonier, J. E.

    2016-10-01

    We report low temperature muon spin relaxation (μ SR ) measurements of the high-transition-temperature (Tc) cuprate superconductors Bi2 +xSr2 -xCaCu2O8 +δ and YBa2Cu3O6.57 , aimed at detecting the mysterious intra-unit cell (IUC) magnetic order that has been observed by spin-polarized neutron scattering in the pseudogap phase of four different cuprate families. A lack of confirmation by local magnetic probe methods has raised the possibility that the magnetic order fluctuates slowly enough to appear static on the time scale of neutron scattering, but too fast to affect μ SR or nuclear magnetic resonance signals. The IUC magnetic order has been linked to a theoretical model for the cuprates, which predicts a long-range ordered phase of electron-current loop order that terminates at a quantum crictical point (QCP). Our study suggests that lowering the temperature to T ˜25 mK and moving far below the purported QCP does not cause enough of a slowing down of fluctuations for the IUC magnetic order to become detectable on the time scale of μ SR . Our measurements place narrow limits on the fluctuation rate of this unidentified magnetic order.

  13. Results and analysis of saltstone cores taken from saltstone disposal unit cell 2A

    Energy Technology Data Exchange (ETDEWEB)

    Reigel, M. M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Hill, K. A. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-03-01

    As part of an ongoing Performance Assessment (PA) Maintenance Plan, Savannah River Remediation (SRR) has developed a sampling and analyses strategy to facilitate the comparison of field-emplaced samples (i.e., saltstone placed and cured in a Saltstone Disposal Unit (SDU)) with samples prepared and cured in the laboratory. The primary objectives of the Sampling and Analyses Plan (SAP) are; (1) to demonstrate a correlation between the measured properties of laboratory-prepared, simulant samples (termed Sample Set 3), and the field-emplaced saltstone samples (termed Sample Set 9), and (2) to validate property values assumed for the Saltstone Disposal Facility (SDF) PA modeling. The analysis and property data for Sample Set 9 (i.e. six core samples extracted from SDU Cell 2A (SDU2A)) are documented in this report, and where applicable, the results are compared to the results for Sample Set 3. Relevant properties to demonstrate the aforementioned objectives include bulk density, porosity, saturated hydraulic conductivity (SHC), and radionuclide leaching behavior.

  14. The modeling of a standalone solid-oxide fuel cell auxiliary power unit

    Science.gov (United States)

    Lu, N.; Li, Q.; Sun, X.; Khaleel, M. A.

    In this research, a Simulink model of a standalone vehicular solid-oxide fuel cell (SOFC) auxiliary power unit (APU) is developed. The SOFC APU model consists of three major components: a controller model; a power electronics system model; and an SOFC plant model, including an SOFC stack module, two heat exchanger modules, and a combustor module. This paper discusses the development of the nonlinear dynamic models for the SOFC stacks, the heat exchangers and the combustors. When coupling with a controller model and a power electronic circuit model, the developed SOFC plant model is able to model the thermal dynamics and the electrochemical dynamics inside the SOFC APU components, as well as the transient responses to the electric loading changes. It has been shown that having such a model for the SOFC APU will help design engineers to adjust design parameters to optimize the performance. The modeling results of the SOFC APU heat-up stage and the output voltage response to a sudden load change are presented in this paper. The fuel flow regulation based on fuel utilization is also briefly discussed.

  15. Fungal spore concentrations in two haematopoietic stem cell transplantation (HSCT) units containing distinct air control systems.

    Science.gov (United States)

    Brun, C P; Miron, D; Silla, L M R; Pasqualotto, A C

    2013-04-01

    Invasive fungal diseases have emerged as important causes of morbidity and mortality in haematological patients. In this study air samples were collected in two haematopoietic stem cell transplantation (HSCT) units, in which distinct air-control systems were in place. In hospital 1 no high-efficiency particulate air (HEPA) filter was available whereas in hospital 2 HSCT rooms were equipped with HEPA filters, with positive air pressure in relation to the corridor. A total of 117 samples from rooms, toilets and corridors were obtained during December 2009 to January 2011, using a six-stage Andersen sampler. In both hospitals, the concentration of potentially pathogenic fungi in the air was reduced in patients' rooms compared to corridors (P < 0·0001). Despite the presence of a HEPA filter in hospital 2, rooms in both hospitals showed similar concentrations of potentially pathogenic fungi (P = 0·714). These findings may be explained by the implementation of additional protective measures in hospital 1, emphasizing the importance of such measures in protected environments.

  16. High-temperature superconductivity in one-unit-cell FeSe films

    Science.gov (United States)

    Wang, Ziqiao; Liu, Chaofei; Liu, Yi; Wang, Jian

    2017-04-01

    Since the dramatic enhancement of the superconducting transition temperature (T c) was reported in a one-unit-cell FeSe film grown on a SrTiO3 substrate (1-UC FeSe/STO) by molecular beam epitaxy (MBE), related research on this system has become a new frontier in condensed matter physics. In this paper, we present a brief review on this rapidly developing field, mainly focusing on the superconducting properties of 1-UC FeSe/STO. Experimental evidence for high-temperature superconductivity in 1-UC FeSe/STO, including direct evidence revealed by transport and diamagnetic measurements, as well as other evidence from scanning tunneling microscopy (STM) and angle-resolved photoemission spectroscopy (ARPES), are overviewed. The potential mechanisms of the enhanced superconductivity are also discussed. There are accumulating arguments to suggest that the strengthened Cooper pairing in 1-UC FeSe/STO originates from the interface effects, specifically the charge transfer and coupling to phonon modes in the TiO2 plane. The study of superconductivity in 1-UC FeSe/STO not only sheds new light on the mechanism of high-temperature superconductors with layered structures, but also provides an insight into the exploration of new superconductors by interface engineering.

  17. Giant repeater F-wave in patients with anterior horn cell disorders. Role of motor unit size.

    Science.gov (United States)

    Ibrahim, I K; el-Abd, M A

    1997-01-01

    Conventional F-wave responses as well as single motor unit F-wave responses together with the volitionally recruited motor unit action potentials (MUAP) were studied in hand and feet muscles of 10 healthy subjects and 32 patients with anterior horn cell disorders. The amplitude of the largest F-wave (Fl) was significantly greater in the affected patients compared with healthy subjects. Giant repeater F-wave responses "up to 4 mV" were recorded in muscles having volitionally recruited giant MUAPs. Although, the group mean percentage of motor unit F-wave responses per stimulation in all tested orthodromic MUAPs was significantly decreased in amyotrophic lateral sclerosis patients, the group mean percentage of motor unit F-wave responses per stimulation in all tested orthodromic MUAPs that gave motor unit F-wave response was significantly increased compared with healthy subjects. The responding orthodromic MUAP gave identical motor unit F-wave response, even for complex polyphasic units. Enhanced monosynaptic (H-) reflex, proximal axon reflex (A-wave), and repetitive muscle response as possible explanations for the giant F-wave responses could be discounted. The electrophysiologic behavior of the giant late responses described here fits well with the criteria of F-waves modulated by newly formed distal (and or proximal) axonal branching.

  18. How thick is the lithosphere?

    Science.gov (United States)

    Kanamori, H; Press, F

    1970-04-25

    A rapid decrease in shear velocity in the suboceanic mantle is used to infer the thickness of the lithosphere. It is proposed that new and highly precise group velocity data constrain the solutions and imply a thickness near 70 km.

  19. Repair of full-thickness tendon injury using connective tissue progenitors efficiently derived from human embryonic stem cells and fetal tissues.

    Science.gov (United States)

    Cohen, Shahar; Leshansky, Lucy; Zussman, Eyal; Burman, Michael; Srouji, Samer; Livne, Erella; Abramov, Natalie; Itskovitz-Eldor, Joseph

    2010-10-01

    The use of stem cells for tissue engineering (TE) encourages scientists to design new platforms in the field of regenerative and reconstructive medicine. Human embryonic stem cells (hESC) have been proposed to be an important cell source for cell-based TE applications as well as an exciting tool for investigating the fundamentals of human development. Here, we describe the efficient derivation of connective tissue progenitors (CTPs) from hESC lines and fetal tissues. The CTPs were significantly expanded and induced to generate tendon tissues in vitro, with ultrastructural characteristics and biomechanical properties typical of mature tendons. We describe a simple method for engineering tendon grafts that can successfully repair injured Achilles tendons and restore the ankle joint extension movement in mice. We also show the CTP's ability to differentiate into bone, cartilage, and fat both in vitro and in vivo. This study offers evidence for the possibility of using stem cell-derived engineered grafts to replace missing tissues, and sets a basic platform for future cell-based TE applications in the fields of orthopedics and reconstructive surgery.

  20. Alterations in adhesion molecules, pro-inflammatory cytokines and cell-derived microparticles contribute to intima-media thickness and symptoms in postmenopausal women.

    Science.gov (United States)

    Figueroa-Vega, Nicté; Moreno-Frías, Carmen; Malacara, Juan Manuel

    2015-01-01

    Menopause, the cessation of menses, occurs with estrogens decline, low-grade inflammation, and impaired endothelial function, contributing to atherosclerotic risk. Intima-media thickness (IMT) is an early subclinical biomarker of atherosclerosis. Inflammation may have a role on symptoms: hot flashes, anxiety, and depressive mood, which also are related to endothelial dysfunction, increased IMT and cardiovascular risk. In this study we compared several inflammatory markers in early vs. late postmenopausal women and studied the association of IMT and symptoms with these markers in the full sample. In a cross-sectional design including 60 women (53.1 ± 4.4 years old) at early and late postmenopause, we evaluated the expression of CD62L, ICAM-1, PSGL-1, CD11b, CD11c, and IL-8R on PBMC by flow cytometry. Serum soluble ICAM-1, sVCAM-1, sCD62E, sCD62P, CXCL8, IL-1β, IL-6, and TNF-α levels were quantified by ELISA. Plasma levels of microparticles (MPs) were determined by FACS. Finally, carotid intima-media thickness (IMT) was measured by ultrasound. We observed that ICAM-1 expression by lymphocytes and serum sVCAM-1 levels were augmented at late postmenopause. Late postmenopause women with severe hot flashes had increased expression of CD62L and IL-8R on neutrophils. By multivariate analysis, the carotid IMT was strongly associated with membrane-bound TNF-α, CD11b expression, Annexin V(+) CD3(+) MPs, LPS-induced NO production, HDL-cholesterol and age. Depressive mood was associated negatively with PSGL-1 and positively with LPS-induced NO. Finally, Log(AMH) levels were associated with carotid IMT, IL-8R expression and time since menopause. IMT and depressive mood were the main clinical features related to vascular inflammation. Aging, hormonal changes and obesity were also related to endothelial dysfunction. These findings provide further evidence for a link between estrogen deficiency and low-grade inflammation in endothelial impairment in mature women.

  1. Alterations in adhesion molecules, pro-inflammatory cytokines and cell-derived microparticles contribute to intima-media thickness and symptoms in postmenopausal women.

    Directory of Open Access Journals (Sweden)

    Nicté Figueroa-Vega

    Full Text Available Menopause, the cessation of menses, occurs with estrogens decline, low-grade inflammation, and impaired endothelial function, contributing to atherosclerotic risk. Intima-media thickness (IMT is an early subclinical biomarker of atherosclerosis. Inflammation may have a role on symptoms: hot flashes, anxiety, and depressive mood, which also are related to endothelial dysfunction, increased IMT and cardiovascular risk. In this study we compared several inflammatory markers in early vs. late postmenopausal women and studied the association of IMT and symptoms with these markers in the full sample. In a cross-sectional design including 60 women (53.1 ± 4.4 years old at early and late postmenopause, we evaluated the expression of CD62L, ICAM-1, PSGL-1, CD11b, CD11c, and IL-8R on PBMC by flow cytometry. Serum soluble ICAM-1, sVCAM-1, sCD62E, sCD62P, CXCL8, IL-1β, IL-6, and TNF-α levels were quantified by ELISA. Plasma levels of microparticles (MPs were determined by FACS. Finally, carotid intima-media thickness (IMT was measured by ultrasound. We observed that ICAM-1 expression by lymphocytes and serum sVCAM-1 levels were augmented at late postmenopause. Late postmenopause women with severe hot flashes had increased expression of CD62L and IL-8R on neutrophils. By multivariate analysis, the carotid IMT was strongly associated with membrane-bound TNF-α, CD11b expression, Annexin V(+ CD3(+ MPs, LPS-induced NO production, HDL-cholesterol and age. Depressive mood was associated negatively with PSGL-1 and positively with LPS-induced NO. Finally, Log(AMH levels were associated with carotid IMT, IL-8R expression and time since menopause. IMT and depressive mood were the main clinical features related to vascular inflammation. Aging, hormonal changes and obesity were also related to endothelial dysfunction. These findings provide further evidence for a link between estrogen deficiency and low-grade inflammation in endothelial impairment in mature women.

  2. Additively Manufactured Open-Cell Porous Biomaterials Made from Six Different Space-Filling Unit Cells: The Mechanical and Morphological Properties

    NARCIS (Netherlands)

    Ahmadi, S.M.; Yavari, S.A.; Wauthle, R.; Pouran, B.; Schrooten, J.; Weinans, H.; Zadpoor, A.A.

    2015-01-01

    It is known that the mechanical properties of bone-mimicking porous biomaterials are a function of the morphological properties of the porous structure, including the configuration and size of the repeating unit cell from which they are made. However, the literature on this topic is limited, primari

  3. Thick-Big Descriptions

    DEFF Research Database (Denmark)

    Lai, Signe Sophus

    The paper discusses the rewards and challenges of employing commercial audience measurements data – gathered by media industries for profitmaking purposes – in ethnographic research on the Internet in everyday life. It questions claims to the objectivity of big data (Anderson 2008), the assumption...... communication systems, language and behavior appear as texts, outputs, and discourses (data to be ‘found’) – big data then documents things that in earlier research required interviews and observations (data to be ‘made’) (Jensen 2014). However, web-measurement enterprises build audiences according...... to a commercial logic (boyd & Crawford 2011) and is as such directed by motives that call for specific types of sellable user data and specific segmentation strategies. In combining big data and ‘thick descriptions’ (Geertz 1973) scholars need to question how ethnographic fieldwork might map the ‘data not seen...

  4. Disentangling The Thick Concept Argument

    DEFF Research Database (Denmark)

    Blomberg, Olle

    2007-01-01

    Critics argue that non-cognitivism cannot adequately account for the existence and nature of some thick moral concepts. They use the existence of thick concepts as a lever in an argument against non-cognitivism, here called the Thick Concept Argument (TCA). While TCA is frequently invoked...

  5. Disentangling The Thick Concept Argument

    DEFF Research Database (Denmark)

    Blomberg, Olle

    2007-01-01

    Critics argue that non-cognitivism cannot adequately account for the existence and nature of some thick moral concepts. They use the existence of thick concepts as a lever in an argument against non-cognitivism, here called the Thick Concept Argument (TCA). While TCA is frequently invoked...

  6. Influence of SiO2 shell thickness on power conversion efficiency in plasmonic polymer solar cells with Au nanorod@SiO2 core-shell structures

    Science.gov (United States)

    Zhang, Ran; Zhou, Yongfang; Peng, Ling; Li, Xue; Chen, Shufen; Feng, Xiaomiao; Guan, Yuqiao; Huang, Wei

    2016-04-01

    Locating core-shell metal nanoparticles into a photoactive layer or at the interface of photoactive layer/hole extraction layer is beneficial for fully employing surface plasmon energy, thus enhancing power conversion efficiency (PCE) in plasmonic organic photovoltaic devices (OPVs). Herein, we first investigated the influence of silica shell thickness in Au nanorods (NRs)@SiO2 core-shell structures on OPV performances by inserting them into poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) and thieno[3,4-b]thiophene/benzodithiophene (PTB7) interface, and amazedly found that a 2–3 nm silica shell onto Au NRs induces a highest short-circuit current density of 21.2 mA cm‑2 and PCE of 9.55%. This is primarily due to an extremely strong local field and a much slower attenuation of localized surface plasmon resonance around ultrathin silica-coated Au NRs, with which the field intensity remains a high value in the active layer, thus sufficiently improves the absorption of PTB7. Our work provides a clear design concept on precise control of the shell of metal nanoparticles to realize high performances in plasmonic OPVs.

  7. Theoretical characterization and design of small molecule donor material containing naphthodithiophene central unit for efficient organic solar cells.

    Science.gov (United States)

    Duan, Yu-Ai; Geng, Yun; Li, Hai-Bin; Jin, Jun-Ling; Wu, Yong; Su, Zhong-Min

    2013-07-15

    To seek for high-performance small molecule donor materials used in heterojunction solar cell, six acceptor-donor-acceptor small molecules based on naphtho[2,3-b:6,7-b']dithiophene (NDT) units with different acceptor units were designed and characterized using density functional theory and time-dependent density functional theory. Their geometries, electronic structures, photophysical, and charge transport properties have been scrutinized comparing with the reported donor material NDT(TDPP)2 (TDPP  =  thiophene-capped diketopyrrolopyrrole). The open circuit voltage (V(oc)), energetic driving force(ΔE(L-L)), and exciton binding energy (E(b)) were also provided to give an elementary understanding on their cell performance. The results reveal that the frontier molecular orbitals of 3-7 match well with the acceptor material PC61 BM, and compounds 3-5 were found to exhibit the comparable performances to 1 and show promising potential in organic solar cells. In particular, comparing with 1, system 7 with naphthobisthiadiazole acceptor unit displays broader absorption spectrum, higher V(oc), lower E(b), and similar carrier mobility. An in-depth insight into the nature of the involved excited states based on transition density matrix and charge density difference indicates that all S1 states are mainly intramolecular charge transfer states with the charge transfer from central NDT unit to bilateral acceptor units, and also imply that the exciton of 7 can be dissociated easily due to its large extent of the charge transfer. In a word, 7 maybe superior to 1 and may act as a promising donor candidate for organic solar cell. Copyright © 2013 Wiley Periodicals, Inc.

  8. Research and analysis on corneal endothelial cell morphology and corneal thickness in patients with diabetics%糖尿病患者角膜内皮细胞形态学和角膜厚度研究分析

    Institute of Scientific and Technical Information of China (English)

    徐武平; 魏春惠; 顾榴丽

    2014-01-01

    AIM: To assess the impact of diabetes on corneal endothelial cells through the quantitative analysis of corneal endothelial cell morphology for patients with diabetics. METHODS: The corneal thickness and endothelial cell morphology of 360 eyes of 299 cases were detected using full automatic corneal endothelial cell analyzer. The normal control group included 175 eyes of 148 cases, and there were 185 eyes of 151 cases for the patients with diabetes, 110 eyes of 92 cases for the non-proliferating phase group and 75 eyes of 59 cases for the proliferating phase group. The average density of central corneal endothelial cells, proportion of hexagonal cells, coefficient of variation and corneal thickness were compared among groups, and then the statistical analysis was conducted. RESULTS: Compared with the cornea of the normal group, in the diabetes group, the coefficient of variation of corneal endothelial cells and central corneal thickness increased, while the average density of central corneal endothelial cells and proportion of hexagonal cells decreased, showing a significant difference (P0. 05). CONCLUSION: Compared with the cornea of normal control group, in the diabetes group, the corneal endothelial cells show abnormal morphology, which aggravates with the severity of lesions, especially for the significant changes in the coefficient of variation and the proportion of hexagonal cells. As a result, the corneal resistance to damage in patients with diabetes will decrease.%目的:通过对糖尿病患者进行角膜内皮细胞形态学定量分析,评估糖尿病对角膜内皮细胞的影响。  方法:应用全自动角膜内皮细胞分析仪对299例360眼进行角膜厚度及内皮细胞形态检测。正常对照组148例175眼,糖尿病患者151例185眼,其中非增殖期组患者92例110眼,增殖期组59例75眼。比较各组患者的中央角膜内皮细胞平均密度、六边形细胞比例、变异系数及角膜厚度,并进行统

  9. Strain in epitaxial MnSi films on Si(111) in the thick film limit studied by polarization-dependent extended x-ray absorption fine structure

    Science.gov (United States)

    Figueroa, A. I.; Zhang, S. L.; Baker, A. A.; Chalasani, R.; Kohn, A.; Speller, S. C.; Gianolio, D.; Pfleiderer, C.; van der Laan, G.; Hesjedal, T.

    2016-11-01

    We report a study of the strain state of epitaxial MnSi films on Si(111) substrates in the thick film limit (100-500 Å) as a function of film thickness using polarization-dependent extended x-ray absorption fine structure (EXAFS). All films investigated are phase-pure and of high quality with a sharp interface between MnSi and Si. The investigated MnSi films are in a thickness regime where the magnetic transition temperature Tc assumes a thickness-independent enhanced value of ≥43 K as compared with that of bulk MnSi, where Tc≈29 K . A detailed refinement of the EXAFS data reveals that the Mn positions are unchanged, whereas the Si positions vary along the out-of-plane [111] direction, alternating in orientation from unit cell to unit cell. Thus, for thick MnSi films, the unit cell volume is essentially that of bulk MnSi—except in the vicinity of the interface with the Si substrate (thin film limit). In view of the enhanced magnetic transition temperature we conclude that the mere presence of the interface, and its specific characteristics, strongly affects the magnetic properties of the entire MnSi film, even far from the interface. Our analysis provides invaluable information about the local strain at the MnSi/Si(111) interface. The presented methodology of polarization dependent EXAFS can also be employed to investigate the local structure of other interesting interfaces.

  10. Absorption enhancement of GaInP nanowires by tailoring transparent shell thicknesses and its application in III-V nanowire/Si film two-junction solar cells.

    Science.gov (United States)

    Li, Xinhua; Shi, Tongfei; Liu, Guangqiang; Wen, Long; Zhou, BuKang; Wang, Yuqi

    2015-09-21

    A non-absorbing transparent shell is proposed to be coated on the outer surface of the core photoactive GaInP nanowire array (NWA) of the III-V nanowire (NW)/Si film two-junction solar cell. Interestingly, the diluted (at the filling ratio of 0.25) GaInP NWA with core / transparent shell structure can absorb more light than that in bare denser (at the filling ratio of 0.5) NWA. This allows for less source material consumption during the fabrication of III-V NWA/Si film two-junction cell. Meanwhile, the condition of current matching between the top III-V NWA and Si film sub cell can be easily fulfilled by tailoring the coating thickness of the transparent coating. Beyond the advantages on light absorption, the surface passivation effects introduced by the addition of some transparent dielectric coatings can reduce the surface recombination rate at the top NWA sub cell surface. This facilitates the effective extraction of photo-generated carriers and enhances output stability of the top NWA sub cell. From electrical simulation, a power conversion efficiency of 29.9% can be obtained at the optimized coating geometry.

  11. Fermi surface properties of paramagnetic NpCd{sub 11} with a large unit cell

    Energy Technology Data Exchange (ETDEWEB)

    Homma, Yoshiya; Aoki, Dai; Shiokawa, Yoshinobu [Institute for Materials Research, Tohoku University, Oarai, Ibaraki 311-1313 (Japan); Haga, Yoshinori; Sakai, Hironori; Ikeda, Shugo; Yamamoto, Etsuji; Nakamura, Akio; Onuki, Yoshichika [Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 (Japan); Settai, Rikio [Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Takeuchi, Tetsuya [Cryogenic Center, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Yamagami, Hiroshi, E-mail: yhomma@imr.tohoku.ac.jp [Department of Physics, Faculty of Science, Kyoto Sangyo University, Kyoto 603-8555 (Japan)

    2010-03-15

    We succeeded in growing a high-quality single crystal of NpCd{sub 11} with the cubic BaHg{sub 11}-type structure by the Cd-self flux method. The lattice parameter of a = 9.2968(2) A and crystallographic positions of the atoms were determined by x-ray single-crystal structure analysis. From the results of the magnetic susceptibility and specific heat experiments, this compound is found to be a 5f-localized paramagnet with the singlet ground state in the crystalline electric field (CEF) scheme. Fermi surface properties were measured using the de Haas-van Alphen (dHvA) technique. Long-period oscillations were observed in the dHvA frequency range of 9.1 x 10{sup 5} to 1.9 x 10{sup 7} Oe, indicating small cross-sectional areas of Fermi surfaces, which is consistent with a small Brillouin zone based on a large unit cell. From the results of dHvA and magnetoresistance experiments, the Fermi surface of NpCd{sub 11} is found to consist of many kinds of closed Fermi surfaces and a multiply-connected-like Fermi surface, although the result of energy band calculations based on the 5f-localized Np{sup 3+}(5f{sup 4}) configuration reveals the existence of only closed Fermi surfaces. The corresponding cyclotron effective mass is small, ranging from 0.1 to 0.7 m{sub 0}, which is consistent with a small electronic specific heat coefficient {gamma} {approx_equal} 10mJ/K{sup 2{center_dot}}mol, revealing no hybridization between the 5f electrons and conduction electrons.

  12. Mesenchymal stem cells seeded on cross-linked and noncross-linked acellular porcine dermal scaffolds for long-term full-thickness hernia repair in a small animal model.

    Science.gov (United States)

    Mestak, Ondrej; Matouskova, Eva; Spurkova, Zuzana; Benkova, Kamila; Vesely, Pavel; Mestak, Jan; Molitor, Martin; Pombinho, Antonio; Sukop, Andrej

    2014-07-01

    Biological meshes are biomaterials consisting of extracellular matrix that are used in surgery particularly for hernia treatment, thoracic wall reconstruction, or silicone implant-based breast reconstruction. We hypothesized that combination of extracellular matrices with autologous mesenchymal stem cells used for hernia repair would result in increased vascularization and increased strength of incorporation. We cultured autologous adipose-derived stem cells harvested from the inguinal region of Wistar rats on cross-linked and noncross-linked porcine extracellular matrices. In 24 Wistar rats, a standardized 2×4 cm fascial defect was created and repaired with either cross-linked or noncross-linked grafts enriched with stem cells. Non-MSC-enriched grafts were used as controls. The rats were sacrificed at 3 months of age. The specimens were examined for the strength of incorporation, vascularization, cell invasion, foreign body reaction, and capsule formation. Both materials showed cellular ingrowth and neovascularization. Comparison of both tested groups with the controls showed no significant differences in the capsule thickness, foreign body reaction, cellularization, or vascularization. The strength of incorporation of the stem cell-enriched cross-linked extracellular matrix specimens was higher than in acellular specimens, but this result was statistically nonsignificant. In the noncross-linked extracellular matrix, the strength of incorporation was significantly higher in the stem cell group than in the acellular group. Seeding of biological meshes with stem cells does not significantly contribute to their increased vascularization. In cross-linked materials, it does not ensure increased strength of incorporation, in contrast to noncross-linked materials. Owing to the fact that isolation and seeding of stem cells is a very complex procedure, we do not see sufficient benefits for its use in the clinical setting.

  13. In vitro fertilization and stem cell harvesting from human embryos: the law and practice in the United States.

    Science.gov (United States)

    Hook, C Christopher

    2010-07-01

    The challenges before science and medicine are these: science must explore the natural world as thoroughly as possible, while still honoring, protecting, serving and preserving the subject of its investigations, and the human beings for whom it is a tool; medicine must confront disease and disability as effectively as possible, while also honoring, protecting, and preserving those beings for whom it serves - all of those beings, not just some, or even most, at the potential expense of others. These goals are challenged by embryo-destructive human embryonic stem cell research. The human embryo is a human being as clearly defined by embryology, and as such should be protected by the codes governing human subject research. However, because of the "potential" benefits offered by pluripotent stem cells, coupled with abortion politics and a very poorly regulated infertility industry, United States governmental advisory commissions and the scientific, medical, and political communities have attempted to define away the humanity of the human embryo, with a few notable exceptions. Because infertility treatments in the United States are poorly regulated, there are large numbers of supernumerary embryos in cryopreservation. However, only a tiny portion of these will ever be potentially available for research, and thus are not a realistic source of the cells necessary to provide treatments to the millions who might benefit from proposed stem cell based therapies. Cloning will not be the answer either, given the millions of women who must be exploited to provide sufficient numbers of eggs to generate the cloned cell lines. Moreover, the disposition decisions parents must make for their extra embryos are often agonizing, and not uncommonly change. The use of supernumerary embryos as a source for human embryonic stem cells is unethical, will never be a sufficient source for the medical treatments expected from stem cell research, and is often a source of great distress for the

  14. In vitro fertilization and stem cell harvesting from human embryos: the law and practice in the United States

    Directory of Open Access Journals (Sweden)

    C. Christopher Hook

    2010-07-01

    Full Text Available The challenges before science and medicine are these: science must explore the natural world as thoroughly as possible, while still honoring, protecting, serving and preserving the subject of its investigations, and the human beings for whom it is a tool; medicine must confront disease and disability as effectively as possible, while also honoring, protecting, and preserving those beings for whom it serves – all of those beings, not just some, or even most, at the potential expense of others. These goals are challenged by embryo-destructive human embryonic stem cell research. The human embryo is a human being as clearly defined by embryology, and as such should be protected by the codes governing human subject research. However, because of the “potential” benefits offered by pluripotent stem cells, coupled with abortion politics and a very poorly regulated infertility industry, United States governmental advisory commissions and the scientific, medical, and political communities have attempted to define away the humanity of the human embryo, witha few notable exceptions. Because infertility treatments in the United States are poorly regulated, there are large numbersof supernumerary embryos in cryopreservation. However, only a tiny portion of these will ever be potentially available for research, and thus are not a realistic source of the cells necessary to provide treatments to the millions who might benefit from proposed stem cell based therapies. Cloning willnot be the answer either, given the millions of women who must be exploited to provide sufficient numbers of eggs to generate the cloned cell lines. Moreover, the disposition decisions parents must make for their extra embryos are often agonizing, and not uncommonly change.The use of supernumerary embryos as a source for human embryonic stem cells is unethical, will never be a sufficient source for the medical treatments expected from stem cell research, and is often a source of

  15. Frequency and Risk Factors Associated with Cord Graft Failure after Transplant with Single-Unit Umbilical Cord Cells Supplemented by Haploidentical Cells with Reduced-Intensity Conditioning.

    Science.gov (United States)

    Tsai, Stephanie B; Liu, Hongtao; Shore, Tsiporah; Fan, Yun; Bishop, Michael; Cushing, Melissa M; Gergis, Usama; Godley, Lucy; Kline, Justin; Larson, Richard A; Martinez, Guadalupe; Mayer, Sebastian; Odenike, Olatoyosi; Stock, Wendy; Wickrema, Amittha; van Besien, Koen; Artz, Andrew S

    2016-06-01

    Delayed engraftment and cord graft failure (CGF) are serious complications after unrelated cord blood (UCB) hematopoietic stem cell transplantation (HSCT), particularly when using low-cell-dose UCB units. The haplo-cord HSCT approach allows the use of a lower dose single UCB unit by co-infusion of a CD34(+) selected haploidentical graft, which provides early transient engraftment while awaiting durable UCB engraftment. We describe the frequency, complications, and risk factors of CGF after reduced-intensity conditioning haplo-cord HSCT. Among 107 patients who underwent haplo-cord HSCT, 94 were assessable for CGF, defined as risk of CGF. We conclude that assessing chimerism at day 30 may foretell impending CGF, and avoidance of high haploidentical cell doses may reduce risk of CGF after haplo-cord HSCT. However, long-term survival is possible after CGF because of predominant haploidentical or mixed chimerism and hematopoietic function.

  16. Development of integrated DMFC and PEM fuel cell units. Final report; Udvikling af integrerede DMFC og PEM braendselscelle enheder. Slutrapport

    Energy Technology Data Exchange (ETDEWEB)

    Odgaard, M. (IRD Fuel Cell Technology, Svendborg (DK))

    2007-06-15

    The 36-month long project 'Development of integrated DMFC and PEM fuel cell units' has been completed. The project goal was to develop a completely new MEA concept for integrated PEM and DMFC unit cells with enhanced power density and in this way obtain a price reduction. The integrated unit cell consists of a MEA, a gas diffusion layer with flow fields completed with bipolar plates and seals. The main focus of the present project was to: 1) Develop new catalyst materials fabricated by the use of FSD (flame spray deposition method). 2) Optimisation of the state-of-the-art MEA materials and electrode structure. 3) Implementation of a model to account for the CO poisoning of PEM fuel cells. Results and progress obtained in the project established that the individual unit cell components were able to meet and follow the road map of LT-PEM FC regarding electrode catalyst loading and fulfilled the targets for Year 2006. The project has resulted in some important successes. The highlights are as follows: The project has resulted in some important successes. The highlights are as follows: 1) MEA structure knowledge acquired in the project provide a sound basis for further progress. 2) A novel method for the synthesis of electrode by using flame spray synthesis was explored. 3) Electrochemical and catalytic behaviours of catalysts activity for CH{sub 3}OH explored. 4) Implementation of a sub model to account for the CO poisoning of PEM FC has been developed. 5) Numerical study of the flow distribution in FC manifolds was developed and completed with experimental data. 6) The electrode catalyst loading targets for year 2006 achieved. 7) The DMFC MEA performance has been improved by 35%. 8) Optimisation of the MEAs fabrication process has been successfully developed. 9) A new simple flow field design has been designed. 10) A procedure for integrated seals has been developed (au)

  17. Photochemical stability of conjugated polymers, electron acceptors and blends for polymer solar cells resolved in terms of film thickness and absorbance

    DEFF Research Database (Denmark)

    Tromholt, Thomas; Vesterager Madsen, Morten; Carlé, Jon Eggert

    2012-01-01

    acceptors poses a challenge to solar cell encapsulation if these materials are to be of commercial interest. The presented method is generally applicable to all types of organic materials to assess photochemical stabilities. The presented results of conjugated polymers demonstrate that this is a powerful...

  18. THE FEATURES OF CONNEXINS EXPRESSION IN THE CELLS OF NEUROVASCLAR UNIT IN NORMAL CONDITIONS AND HYPOXIA IN VITRO

    Directory of Open Access Journals (Sweden)

    A. V. Morgun

    2014-01-01

    Full Text Available The aim of this research was to assess a role of connexin 43 (Cx43 and associated molecule CD38 in the regulation of cell-cell interactions in the neurovascular unit (NVU in vitro in physiological conditions and in hypoxia.Materials and methods. The study was done using the original neurovascular unit model in vitro. The NVU consisted of three cell types: neurons, astrocytes, and cerebral endothelial cells derived from rats. Hypoxia was induced by incubating cells with sodium iodoacetate for 30 min at37 °C in standard culture conditions.Results. We investigated the role of connexin 43 in the regulation of cell interactions within the NVU in normal and hypoxic injury in vitro. We found that astrocytes were characterized by high levels of expression of Cx43 and low level of CD38 expression, neurons demonstrated high levels of CD38 and low levels of Cx43. In hypoxic conditions, the expression of Cx43 and CD38 in astrocytes markedly increased while CD38 expression in neurons decreased, however no changes were found in endothelial cells. Suppression of Cx43 activity resulted in down-regulation of CD38 in NVU cells, both in physiological conditions and at chemical hypoxia.Conclusion. Thus, the Cx-regulated intercellular NAD+-dependent communication and secretory phenotype of astroglial cells that are the part of the blood-brain barrier is markedly changed in hypoxia.

  19. Tool for Generation of MAC/GMC Representative Unit Cell for CMC/PMC Analysis

    Science.gov (United States)

    Murthy, Pappu L. N.; Pineda, Evan J.

    2016-01-01

    This document describes a recently developed analysis tool that enhances the resident capabilities of the Micromechanics Analysis Code with the Generalized Method of Cells (MAC/GMC) 4.0. This tool is especially useful in analyzing ceramic matrix composites (CMCs), where higher fidelity with improved accuracy of local response is needed. The tool, however, can be used for analyzing polymer matrix composites (PMCs) as well. MAC/GMC 4.0 is a composite material and laminate analysis software developed at NASA Glenn Research Center. The software package has been built around the concept of the generalized method of cells (GMC). The computer code is developed with a user friendly framework, along with a library of local inelastic, damage, and failure models. Further, application of simulated thermomechanical loading, generation of output results, and selection of architectures to represent the composite material have been automated to increase the user friendliness, as well as to make it more robust in terms of input preparation and code execution. Finally, classical lamination theory has been implemented within the software, wherein GMC is used to model the composite material response of each ply. Thus, the full range of GMC composite material capabilities is available for analysis of arbitrary laminate configurations as well. The primary focus of the current effort is to provide a graphical user interface (GUI) capability that generates a number of different user-defined repeating unit cells (RUCs). In addition, the code has provisions for generation of a MAC/GMC-compatible input text file that can be merged with any MAC/GMC input file tailored to analyze composite materials. Although the primary intention was to address the three different constituents and phases that are usually present in CMCs-namely, fibers, matrix, and interphase-it can be easily modified to address two-phase polymer matrix composite (PMC) materials where an interphase is absent. Currently, the

  20. Effects of Platelet-Rich Plasma & Platelet-Rich Fibrin with and without Stromal Cell-Derived Factor-1 on Repairing Full-Thickness Cartilage Defects in Knees of Rabbits

    Science.gov (United States)

    Bahmanpour, Soghra; Ghasemi, Maryam; Sadeghi-Naini, Mohsen; Kashani, Iraj Ragerdi

    2016-01-01

    Background: The purpose of this study was to create biomaterial scaffolds like platelet-rich plasma (PRP) and platelet-rich fibrin (PRF) containing stromal cell-derived factor-1 (SDF1) as a chemokine to induce hyaline cartilage regeneration of rabbit knee in a full thickness defect. Methods: We created a full thickness defect in the trochlear groove of thirty-six bilateral knees of eighteen mature male rabbits. The knees were randomly divided into six groups (group I: untreated control, group II: PRP, group III: PRF, group IV: Gelatin+SDF1, group V: PRP+SDF1, and group VI: PRF+SDF1). After four weeks, the tissue specimens were evaluated by macroscopic examination and histological grading, immunofluorescent staining for collagen type II, and analyzed for cartilage marker genes by real-time PCR. The data were compared using statistical methods (SPSS 20, Kruskal-Wallis test, Bonferroni post hoc test and P<0.05). Results: Macroscopic evaluations revealed that international cartilage repair society (ICRS) scores of the PRF+SDF1 group were higher than other groups. Microscopic analysis showed that the ICRS score of the PRP group was significantly lower than other groups. Immunofluorescent staining for collagen II demonstrated a remarkable distribution of type II collagen in the Gel+SDF1, PRP+SDF1 and PRF+SDF1 groups compared with other groups. Real-time PCR analysis revealed that mRNA expression of SOX9 and aggrecan were significantly greater in the PRF+SDF1, PRP+SDF1, Gel+SDF1 and PRF groups than the control group (P<0.05). Conclusion: Our results indicate that implantation of PRF scaffold containing SDF1 led to the greatest evaluation scores of full-thickness lesions in rabbits. PMID:27853331

  1. Indium phosphide solar cell research in the United States: Comparison with non-photovoltaic sources

    Science.gov (United States)

    Weinberg, I.; Swartz, C. K.; Hart, R. E., Jr.

    1989-01-01

    Highlights of the InP solar cell research program are presented. Homojunction cells with efficiencies approaching 19 percent are demonstrated, while 17 percent is achieved for ITO/InP cells. The superior radiation resistance of the two latter cell configurations over both Si and GaAs cells has been shown. InP cells aboard the LIPS3 satellite show no degradation after more than a year in orbit. Computed array specific powers are used to compare the performance of an InP solar cell array to solar dynamic and nuclear systems.

  2. Lower muscle regenerative potential in full-thickness supraspinatus tears compared to partial-thickness tears.

    Science.gov (United States)

    Lundgreen, Kirsten; Lian, Oystein Bjerkestrand; Engebretsen, Lars; Scott, Alex

    2013-12-01

    Rotator cuff tears are associated with secondary rotator cuff muscle pathology, which is definitive for the prognosis of rotator cuff repair. There is little information regarding the early histological and immunohistochemical nature of these muscle changes in humans. We analyzed muscle biopsies from patients with supraspinatus tendon tears. Supraspinatus muscle biopsies were obtained from 24 patients undergoing arthroscopic repair of partial- or full-thickness supraspinatus tendon tears. Tissue was formalin-fixed and processed for histology (for assessment of fatty infiltration and other degenerative changes) or immunohistochemistry (to identify satellite cells (CD56+), proliferating cells (Ki67+), and myofibers containing predominantly type 1 or 2 myosin heavy chain (MHC)). Myofiber diameters and the relative content of MHC1 and MHC2 were determined morphometrically. Degenerative changes were present in both patient groups (partial and full-thickness tears). Patients with full-thickness tears had a reduced density of satellite cells, fewer proliferating cells, atrophy of MHC1+ and MHC2+ myofibers, and reduced MHC1 content. Full-thickness tears show significantly reduced muscle proliferative capacity, myofiber atrophy, and loss of MHC1 content compared to partial-thickness supraspinatus tendon tears.

  3. Effect of composition, microstructure and component thickness on the oxidation behaviour of laves phase strengthened interconnect steel for solid oxide fuel cells (SOFC)

    OpenAIRE

    2013-01-01

    The high-Cr, Laves phase strengthened ferritic steel, Crofer 22 H, has recently been proposed as construction material for interconnects in solid oxide fuel cells (SOFC). Aim of the present investigation was to get more insight in the details of SOFC relevant properties, mostly oxidation behaviour and oxide electronic conductivity, in simulated SOFC service environments as a function of temperature, with main emphasis on the most commonly used operating temperature 800°C. The present studies ...

  4. Observation and theoretical simulation of electromagnetically induced transparency and enhanced velocity selective optical pumping in cesium vapour in a micrometric thickness optical cell

    Science.gov (United States)

    Krasteva, A.; Ray, B.; Slavov, D.; Todorov, P.; Ghosh, P. N.; Mitra, S.; Cartaleva, S.

    2014-09-01

    Observation of electromagnetically induced transparency (EIT) and enhanced velocity selective optical pumping (VSOP) signals in a micrometric cell with cesium is reported. The line shape and non-linear features observed in the case of fluorescence in the direction parallel to the cell windows and the transmission spectra observed along the propagation direction of the probe beam show considerable differences in the spectral profile. A theoretical model based on five level optical Bloch equations is used to simulate the spectra. The Doppler convolution includes all possible orientations of atomic velocities with respect to the laser beam direction. Atoms moving nearly parallel to the windows and perpendicular to the collinear pump and probe beams have much lower Doppler shift and hence produce considerable narrowing of the Doppler background in the fluorescence spectra. The coherence decay rate is also low for such atoms as they do not meet with the cell walls. The simulated curves reproduce the observed sharp EIT peaks and enhanced broad VSOP signals for the closed probe transition in the fluorescence and absorption spectra. The observed effect of detuning of the pump frequency on the non-linear features is also reproduced by the simulation.

  5. Tunable Multifunctional Thermal Metamaterials: Manipulation of Local Heat Flux via Assembly of Unit-Cell Thermal Shifters.

    Science.gov (United States)

    Park, Gwanwoo; Kang, Sunggu; Lee, Howon; Choi, Wonjoon

    2017-01-20

    Thermal metamaterials, designed by transformation thermodynamics are artificial structures that can actively control heat flux at a continuum scale. However, fabrication of them is very challenging because it requires a continuous change of thermal properties in materials, for one specific function. Herein, we introduce tunable thermal metamaterials that use the assembly of unit-cell thermal shifters for a remarkable enhancement in multifunctionality as well as manufacturability. Similar to the digitization of a two-dimensional image, designed thermal metamaterials by transformation thermodynamics are disassembled as unit-cells thermal shifters in tiny areas, representing discretized heat flux lines in local spots. The programmed-reassembly of thermal shifters inspired by LEGO enable the four significant functions of thermal metamaterials-shield, concentrator, diffuser, and rotator-in both simulation and experimental verification using finite element method and fabricated structures made from copper and PDMS. This work paves the way for overcoming the structural and functional limitations of thermal metamaterials.

  6. Tunable Multifunctional Thermal Metamaterials: Manipulation of Local Heat Flux via Assembly of Unit-Cell Thermal Shifters

    Science.gov (United States)

    Park, Gwanwoo; Kang, Sunggu; Lee, Howon; Choi, Wonjoon

    2017-01-01

    Thermal metamaterials, designed by transformation thermodynamics are artificial structures that can actively control heat flux at a continuum scale. However, fabrication of them is very challenging because it requires a continuous change of thermal properties in materials, for one specific function. Herein, we introduce tunable thermal metamaterials that use the assembly of unit-cell thermal shifters for a remarkable enhancement in multifunctionality as well as manufacturability. Similar to the digitization of a two-dimensional image, designed thermal metamaterials by transformation thermodynamics are disassembled as unit-cells thermal shifters in tiny areas, representing discretized heat flux lines in local spots. The programmed-reassembly of thermal shifters inspired by LEGO enable the four significant functions of thermal metamaterials—shield, concentrator, diffuser, and rotator—in both simulation and experimental verification using finite element method and fabricated structures made from copper and PDMS. This work paves the way for overcoming the structural and functional limitations of thermal metamaterials. PMID:28106156

  7. Compact Circularly Polarized Patch Antenna Using a Composite Right/Left-Handed Transmission Line Unit-Cell

    Directory of Open Access Journals (Sweden)

    L. Geng

    2013-04-01

    Full Text Available A compact circularly polarized (CP patch antenna using a composite right/left-handed (CRLH transmission line (TL unit-cell is proposed. The CRLH TL unit-cell includes a complementary split ring resonator (CSRR for shunt inductance and a gap loaded with a circular-shaped slot for series capacitance. The CSRR can decrease the TM10 mode resonance frequency, thus reducing the electrical size of the proposed antenna. In addition, the asymmetry of the CSRR brings about the TM01 mode, which can be combined with the TM10 mode by changing the slot radius. The combination of these two orthogonal modes with 90° phase shift makes the proposed antenna provide a CP property. The experimental results show that the proposed antenna has a wider axial ratio bandwidth and a smaller electrical size than the reported CP antennas. Moreover, the proposed antenna is designed without impedance transformer, 90° phase shift, dual feed and ground via.

  8. 非晶硅/多晶硅太阳电池吸收层厚度的设计优化%Designing and optimizing thickness of absorption layer of α-Si/poly -silicon solar cell

    Institute of Scientific and Technical Information of China (English)

    张研研; 陈祺; 刘晟楠; 田辉; 史力斌

    2013-01-01

    It is discoverd by simulation using the program of AMPS that photovoltaicperformance of the solar cell is improved after increasing a layer of heavily doped amorphous silicon as the back surface field for α-Si /poly-Si solar cell .It is also showed that the conversion efficiency of the solar cell arrives peaks at the absorp-tion layer thickness of 5μm and 15 μm respectively with and without the back surface field .Therefore , the solar cell with back surface field is more benificial to saving material and reducing cost .%为非晶硅/多晶硅太阳电池设计增加了一层重掺杂的非晶硅薄膜作为背场,利用AMPS程序模拟发现电池的光伏性能明显改善。模拟中还发现,有无背场时,电池的转换效率分别在吸收层厚度为5μm和15μm时达到峰值,故有背场的太阳电池更有利于节约材料,降低成本。

  9. Interfacing of science, medicine and law: The stem cell patent controversy in the United States and the European Union

    Directory of Open Access Journals (Sweden)

    Sonya eDavey

    2015-11-01

    Full Text Available The patent eligibility of stem cells – particularly those derived from human embryos – has long been under debate in both the scientific and legal communities. On the basis of moral grounds, the European Patent Office (EPO has refrained from granting patents for stem cells obtained through the destruction of human embryos. On the contrary, the United States Patent and Trademark Office (USPTO has historically granted patents regarding the isolation and use of human embryonic and other stem cells. To date, these US patents remain valid despite an increasing onslaught of challenges in court. However, recent precedents established in US courts significantly narrow the scope of patent eligibility within biotechnology. This article compares the implications of recent legal changes on stem cell patent eligibility between the EU and US.

  10. Red cell storage age policy for patients with sickle cell disease: A survey of transfusion service directors in the United States.

    Science.gov (United States)

    Karafin, Matthew S; Singavi, Arun K; Irani, Mehraboon S; Puca, Kathleen E; Baumann Kreuziger, Lisa; Simpson, Pippa; Field, Joshua J

    2016-02-01

    In patients with sickle cell disease (SCD), the effects of the red cell storage lesion are not well defined. The objective of this study was to determine the prevalence of transfusion services that limit red cell units by storage age for patients with SCD. We developed a 22 question survey of transfusion service director opinions and their corresponding blood bank policies. Target subjects were systematically identified on the AABB website. Responses were recorded in SurveyMonkey and summarized using standard statistical techniques. Ninety transfusion service directors responded to the survey. Response rate was 22%. Only 23% of respondents had storage age policies in place for patients with SCD, even though 36% of respondents consider older units to be potentially harmful in this patient population. Of those with a policy, a less-than 15 day storage age requirement was most often used (75%), but practices varied, and most respondents (65%) agreed that evidence-based guidelines regarding storage age are needed for patients with SCD. Policies, practices and opinions about the risks of older units for patients with SCD vary. As patients with SCD may have unique susceptibilities to features of the red cell storage lesion, prospective studies in this population are needed to determine best practice.

  11. A Miniaturized Antenna with Negative Index Metamaterial Based on Modified SRR and CLS Unit Cell for UWB Microwave Imaging Applications

    Directory of Open Access Journals (Sweden)

    Md. Moinul Islam

    2015-01-01

    Full Text Available A miniaturized antenna employing a negative index metamaterial with modified split-ring resonator (SRR and capacitance-loaded strip (CLS unit cells is presented for Ultra wideband (UWB microwave imaging applications. Four left-handed (LH metamaterial (MTM unit cells are located along one axis of the antenna as the radiating element. Each left-handed metamaterial unit cell combines a modified split-ring resonator (SRR with a capacitance-loaded strip (CLS to obtain a design architecture that simultaneously exhibits both negative permittivity and negative permeability, which ensures a stable negative refractive index to improve the antenna performance for microwave imaging. The antenna structure, with dimension of 16 × 21 × 1.6 mm3, is printed on a low dielectric FR4 material with a slotted ground plane and a microstrip feed. The measured reflection coefficient demonstrates that this antenna attains 114.5% bandwidth covering the frequency band of 3.4–12.5 GHz for a voltage standing wave ratio of less than 2 with a maximum gain of 5.16 dBi at 10.15 GHz. There is a stable harmony between the simulated and measured results that indicate improved nearly omni-directional radiation characteristics within the operational frequency band. The stable surface current distribution, negative refractive index characteristic, considerable gain and radiation properties make this proposed negative index metamaterial antenna optimal for UWB microwave imaging applications.

  12. On the Effect of Unit-Cell Parameters in Predicting the Elastic Response of Wood-Plastic Composites

    Directory of Open Access Journals (Sweden)

    Fatemeh Alavi

    2013-01-01

    Full Text Available This paper presents a study on the effect of unit-cell geometrical parameters in predicting elastic properties of a typical wood plastic composite (WPC. The ultimate goal was obtaining the optimal values of representative volume element (RVE parameters to accurately predict the mechanical behavior of the WPC. For each unit cell, defined by a given combination of the above geometrical parameters, finite element simulation in ABAQUS was carried out, and the corresponding stress-strain curve was obtained. A uniaxial test according to ASTM D638-02a type V was performed on the composite specimen. Modulus of elasticity was determined using hyperbolic tangent function, and the results were compared to the sets of finite element analyses. Main effects of RVE parameters and their interactions were demonstrated and discussed, specially regarding the inclusion of two adjacent wood particles within one unit cell of the material. Regression analysis was performed to mathematically model the RVE parameter effects and their interactions over the modulus of elasticity response. The model was finally employed in an optimization analysis to arrive at an optimal set of RVE parameters that minimizes the difference between the predicted and experimental moduli of elasticity.

  13. A Miniaturized Antenna with Negative Index Metamaterial Based on Modified SRR and CLS Unit Cell for UWB Microwave Imaging Applications.

    Science.gov (United States)

    Islam, Md Moinul; Islam, Mohammad Tariqul; Samsuzzaman, Md; Faruque, Mohammad Rashed Iqbal; Misran, Norbahiah; Mansor, Mohd Fais

    2015-01-23

    A miniaturized antenna employing a negative index metamaterial with modified split-ring resonator (SRR) and capacitance-loaded strip (CLS) unit cells is presented for Ultra wideband (UWB) microwave imaging applications. Four left-handed (LH) metamaterial (MTM) unit cells are located along one axis of the antenna as the radiating element. Each left-handed metamaterial unit cell combines a modified split-ring resonator (SRR) with a capacitance-loaded strip (CLS) to obtain a design architecture that simultaneously exhibits both negative permittivity and negative permeability, which ensures a stable negative refractive index to improve the antenna performance for microwave imaging. The antenna structure, with dimension of 16 × 21 × 1.6 mm³, is printed on a low dielectric FR4 material with a slotted ground plane and a microstrip feed. The measured reflection coefficient demonstrates that this antenna attains 114.5% bandwidth covering the frequency band of 3.4-12.5 GHz for a voltage standing wave ratio of less than 2 with a maximum gain of 5.16 dBi at 10.15 GHz. There is a stable harmony between the simulated and measured results that indicate improved nearly omni-directional radiation characteristics within the operational frequency band. The stable surface current distribution, negative refractive index characteristic, considerable gain and radiation properties make this proposed negative index metamaterial antenna optimal for UWB microwave imaging applications.

  14. A Miniaturized Antenna with Negative Index Metamaterial Based on Modified SRR and CLS Unit Cell for UWB Microwave Imaging Applications

    Science.gov (United States)

    Islam, Md. Moinul; Islam, Mohammad Tariqul; Samsuzzaman, Md.; Faruque, Mohammad Rashed Iqbal; Misran, Norbahiah; Mansor, Mohd Fais

    2015-01-01

    A miniaturized antenna employing a negative index metamaterial with modified split-ring resonator (SRR) and capacitance-loaded strip (CLS) unit cells is presented for Ultra wideband (UWB) microwave imaging applications. Four left-handed (LH) metamaterial (MTM) unit cells are located along one axis of the antenna as the radiating element. Each left-handed metamaterial unit cell combines a modified split-ring resonator (SRR) with a capacitance-loaded strip (CLS) to obtain a design architecture that simultaneously exhibits both negative permittivity and negative permeability, which ensures a stable negative refractive index to improve the antenna performance for microwave imaging. The antenna structure, with dimension of 16 × 21 × 1.6 mm3, is printed on a low dielectric FR4 material with a slotted ground plane and a microstrip feed. The measured reflection coefficient demonstrates that this antenna attains 114.5% bandwidth covering the frequency band of 3.4–12.5 GHz for a voltage standing wave ratio of less than 2 with a maximum gain of 5.16 dBi at 10.15 GHz. There is a stable harmony between the simulated and measured results that indicate improved nearly omni-directional radiation characteristics within the operational frequency band. The stable surface current distribution, negative refractive index characteristic, considerable gain and radiation properties make this proposed negative index metamaterial antenna optimal for UWB microwave imaging applications. PMID:28787945

  15. Intra-unit-cell magnetic correlations near optimal doping in YBa2Cu3O6.85.

    Science.gov (United States)

    Mangin-Thro, L; Sidis, Y; Wildes, A; Bourges, P

    2015-07-03

    The pseudo-gap phenomenon in copper oxide superconductors is central to any description of these materials as it prefigures the superconducting state itself. A magnetic intra-unit-cell order was found to occur just at the pseudo-gap temperature in four cuprate high-Tc superconducting families. Here we present polarized neutron-scattering measurements of nearly optimally doped YBa2Cu3O6.85, carried out on two different spectrometers, that reveal several features. The intra-unit-cell order consists of finite-sized planar domains that are very weakly correlated along the c axis. At high temperature, only the out-of-plane magnetic components correlate, indicating a strong Ising anisotropy. An aditional in-plane response develops at low temperature, giving rise to an apparent tilt of the magnetic moment. The discovery of these two regimes puts stringent constraints, which are tightly bound to the pseudo-gap physics, on the intrinsic nature of intra-unit-cell order.

  16. Fuel Cell Backup Power Unit Configuration and Electricity Market Participation: A Feasibility Study

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Zhiwen [National Renewable Energy Lab. (NREL), Golden, CO (United States); Eichman, Josh [National Renewable Energy Lab. (NREL), Golden, CO (United States); Kurtz, Jennifer [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2017-03-13

    This National Renewable Energy Laboratory industry-inspired Laboratory Directed Research and Development project evaluates the feasibility and economics of using fuel cell backup power systems in cell towers to provide grid services (e.g., balancing, ancillary services, demand response). The work is intended to evaluate the integration of thousands of under-utilized, clean, efficient, and reliable fuel cell systems that are already installed in cell towers for potential grid and ancillary services.

  17. Optimum thickness of Mossbauer absorber

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    If recoilless fraction fa is available, the optimum absorber thickness dopt can be calculated by maximizing the signal to noise ratio or Q factor. In this work,an approach presented is to get experimental Qexp as a function of the thickness, and then fitting Qexp by its theoretical expression gives fa value. At last the dopt value is deduced from a maximum on the fitted curve. In such a way, thicknesses of six specimens with quadrupole or magnetic hyperfine splitting were optimized.

  18. Repair of large full-thickness cartilage defect by activating endogenous peripheral blood stem cells and autologous periosteum flap transplantation combined with patellofemoral realignment.

    Science.gov (United States)

    Fu, Wei-Li; Ao, Ying-Fang; Ke, Xiao-Yan; Zheng, Zhuo-Zhao; Gong, Xi; Jiang, Dong; Yu, Jia-Kuo

    2014-03-01

    Minimal-invasive procedure and one-step surgery offer autologous mesenchymal stem cells derived from peripheral blood (PB-MSCs) a promising prospective in the field of cartilage regeneration. We report a case of a 19-year-old male athlete of kickboxing with ICRS grade IV chondral lesions at the 60° region of lateral femoral trochlea, which was repaired by activating endogenous PB-MSCs plus autologous periosteum flap transplantation combined with correcting the patellofemoral malalignment. After a 7.5 year follow-up, the result showed that the patient returned to competitive kickboxing. Second-look under arthroscopy showed a smooth surface at 8 months postoperation. The IKDC 2000 subjective score, Lysholm score and Tegner score were 95, 98 and 9 respectively at the final follow up. CT and MRI evaluations showed a significant improvement compared with those of pre-operation. © 2013.

  19. Development of an all-metal thick film cost effective metallization system for solar cells. Final report, May 1980-January 1983

    Energy Technology Data Exchange (ETDEWEB)

    Ross, B.; Parker, J.

    1983-12-01

    Properties of copper pastes did not reproduce earlier results in rheology and metallurgy. Electrodes made with pastes produced under the previous contract were analyzed and raw material characteristics were compared. A needle-like structure was observed on the earlier electroded solar cells, and was identified as eutectic copper-silicon. Experiments were conducted with variations in paste parameters, firing conditions, including gas ambients, furnace furniture, silicon surface and others to improve performance characteristics. Improved adhesion with copper pastes containing silver fluoride, as well as those containing fluorocarbon powder was obtained. Front contact experiments were done with silver fluoride activated pastes on bare silicon, silicon oxide and silicon nitride coated silicon wafers. Adhesion of pastes with AgF on silicon nitride coated wafers was good, but indications were that all cells were shunted and the conclusion was that these systems were unsuitable for front contacts. Experiments with aluminum back surfaces and screened contacts to that surface were begun. Low temperature firing tended to result in S shaped IV curves. This was attributed to a barrier formed at the silicon-copper interface. A cooperative experiment was initiated on the effect of heat-treatments in various atmospheres on the hydrogen profile of silicon surfaces. Contact theory was explored to determine the role of various parameters on tunneling and contact resistance. Data confirm that the presence of eutectic Al-Si additions are beneficial for low contact resistance and fill factors in back contacts. Copper pastes with different silver fluoride additions were utilized as front contacts at two temperatures. Data shows various degrees of shunting. Finally, an experiment was run with carbon monoxide gas used as the reducing ambient during firing.

  20. Static and dynamic through thickness lamina properties of thick laminates

    NARCIS (Netherlands)

    Lahuerta, F.; Nijssen, R.P.L.; Van der Meer, F.P.; Sluys, L.J.

    2015-01-01

    Thick laminates are increasingly present in large composites structures such as wind turbine blades. Different factors are suspected to be involved in the decreased static and dynamic performance of thick laminates. These include the effect of self-heating, the scaling effect, and the manufacturing

  1. Reaggregation of human, chick, and human embryonic brain cells. Factors influencing the formation of a histiotypic unit.

    Science.gov (United States)

    Lodin, Z; Fleischmannová, V; Hájková, B; Faltin, J; Hartman, J

    1981-01-01

    1. Aggregation of embryo human, mouse, and chick brain cells was studied. The optimum age interval of donors from different species was determined. 2. The significance of different dissociation procedures (mild trypsinisation followed by sieving, trypsinisation + DNA digestion, mechanical dissociation in 1 or 2 steps, and Ca2+ chelation by EGTA) for the rate of aggregation was estimated. A significant reduction of aggregation was observed after one step mechanical dissociation. Nonspecific adhesion of cells on DNA molecules was found only during the first stages of aggregation. 3. The curve of aggregation kinetics follows the curve of floculation kinetics. 90% free cells disappear from the medium after 2 h of aggregation and a large number of microaggregates are formed which condense after 20 to 24 h into compact aggregates. The time course of aggregation was similar for all cells dissociated by different means. Small differences in the rate of aggregation, caused by dissociation procedures, were apparent only during the first stages of aggregation. 4. The histiotypic unit formed by aggregation of human, mouse, and chick embryo brain cells exhibits some common and some specific features. During aggregation a multiple structural reconstruction takes place and a limited number of cells are exchanged or sorted out from aggregates into the medium. 5. The structural organisation of aggregates from differently dissociated cells differs in several aspects. This indicates that membrane surface structures are influenced differently by dissociation and behave differently during distinct stages of aggregation.

  2. 分离培养汗腺导管部细胞的新方法%A new way for isolation and cultivation of sweat gland ductual cells from human split-thickness skin in vitro

    Institute of Scientific and Technical Information of China (English)

    雷永红; 付小兵; 盛志勇; 蔡飒; 孙同柱

    2009-01-01

    目的 探讨建立汗腺导管部细胞分离的新技术.方法 成人仞厚皮片和薄中厚皮片标本(n=10)剪碎后用Ⅱ型胶原酶消化12 h,吸取并转移汗腺导管到培养皿中贴壁培养.应用流式细胞仪、免疫组织化学染色和逆转录-聚合酶链式反应(RT-PCR)以及蛋白印迹(Western Blot)分析检测培养细胞的汗腺特异标志CEA、CK8、CK18、CK19抗原表达,并用膜片钳技术检测培养细胞膜上阿米洛利(amiloride)敏感Na~+离子通道,用t检验比较分析两组间实验数据.结果 汗腺导管贴壁48 h后,围绕汗腺导管出现单层扁平的上皮细胞,生长2~4周融合成片.流式细胞学检查示原代培养汗腺导管细胞与原代培养汗腺细胞在癌胚抗原(CEA)阳性率[(90.26±1.12)%vs.(89.70±1.43)%]和细胞角蛋白8(CK8)阳性率[(94.41±1.84)%vs.(93.65±1.63)%]上,差异无统计学意义(P>0.05).形态学染色汗腺导管细胞抗CEA、CK8、CK18、CK19染色均为阳性.RT-PCR表明原代培养汗腺导管细胞表达CEA、CK8、CK18、CK19基因,Western Blot清晰显示CEA条带,CK8、CK18、CK19蛋白条带.膜片钳检测表明原代培养汗腺导管细胞膜上存在amiloride敏感Na~+离子通道.无血清表皮细胞EpiLife培养基在汗腺导管细胞生长过程中抑制成纤维细胞生长.结论 从仞厚皮片和中厚皮片分离培养汗腺导管部细胞的方法较传统的分离方法具有简便快速的优点,EpiLife培养基可抑制培养过程中成纤维细胞的生长,可以在体外建立最佳汗腺导管细胞模型.%Objective To explore a new method of isolation and culture of eccrine sweat gland ductual cells from human split-thickness skin graft in vitro. Methods Human split-thickness skin graft which was presented by volunteer (n=10) was digested with type Ⅱ collagenase, and then sweat gland duct were isolated from the split-thickness skin graft, primary cultures were incubated at 37 ℃ in humidified atmosphere of 5% CO_2,95% O_2

  3. Dye-sensitized solar cells based on thick highly ordered TiO(2) nanotubes produced by controlled anodic oxidation in non-aqueous electrolytic media.

    Science.gov (United States)

    Stergiopoulos, T; Ghicov, A; Likodimos, V; Tsoukleris, D S; Kunze, J; Schmuki, P; Falaras, P

    2008-06-11

    Dye-sensitized solar cells (DSSCs) were prepared using TiO(2) nanotubes, grown by controlled Ti anodic oxidation in non-aqueous media. Smooth, vertically oriented TiO(2) nanotube arrays, presenting a high degree of self-organization and a length of 20 µm, have been grown using ethylene glycol electrolyte containing HF. As-grown nanotubes exhibit an amorphous structure, which transforms to the anatase TiO(2) crystalline phase upon post-annealing in air at 450 °C. Atomic force microscopy (AFM) revealed the porous morphology together with high roughness and fractality of the surface. The annealed tubes were sensitized by the standard N719 ruthenium dye and the adsorption was characterized using resonance micro-Raman spectroscopy and adsorption-desorption measurements. The sensitized tubes were further used as active photoelectrodes after incorporation in sandwich-type DSSCs using both liquid and solidified electrolytes. The efficiencies obtained under air mass (AM) 1.5 conditions, using a back-side illumination geometry, were very promising: 0.85% using a composite polymer redox electrolyte, while the efficiency was further increased up to 1.65% using a liquid electrolyte.

  4. Compressor-expander units for mobile fuel cell systems; Verdichter und Expander fuer mobile Brennstoffzellensysteme

    Energy Technology Data Exchange (ETDEWEB)

    Lang, O. [FEV Motorentechnik GmbH, Aachen (Germany).; Pischinger, S.; Schoenfelder, C.; Steidten, T. [RWTH Aachen (DE). Lehrstuhl fuer Verbrennungskraftmaschinen (VKA)

    2004-08-01

    The air supply of hydrogen-powered fuel cell systems containing PEM fuel cells has a significant impact on their efficiency and mode of operation. Therefore, several mechanical compressors and expanders were examined at the RWTH Aachen. Simulations were then performed to determine the behaviour of the fuel cell system. This article discusses the findings of a project commissioned by the Forschungsvereinigung Verbrennungskraftmaschinen e.V. (FVV). (orig.)

  5. Q Fever Outbreak Among Travelers to Germany Who Received Live Cell Therapy--United States and Canada, 2014.

    Science.gov (United States)

    Robyn, Misha P; Newman, Alexandra P; Amato, Michael; Walawander, Mary; Kothe, Cynthia; Nerone, James D; Pomerantz, Cynthia; Behravesh, Casey Barton; Biggs, Holly M; Dahlgren, F Scott; Pieracci, Emily G; Whitfield, Yvonne; Sider, Doug; Ozaldin, Omar; Berger, Lisa; Buck, Peter A; Downing, Mark; Blog, Debra

    2015-10-02

    During September–November 2014, the New York State Department of Health (NYSDOH) was notified of five New York state residents who had tested seropositive for Coxiella burnetii, the causative agent of Q fever. All five patients had symptoms compatible with Q fever (e.g., fever, fatigue, chills, and headache) and a history of travel to Germany to receive a medical treatment called "live cell therapy" (sometimes called "fresh cell therapy") in May 2014. Live cell therapy is the practice of injecting processed cells from organs or fetuses of nonhuman animals (e.g., sheep) into human recipients. It is advertised to treat a variety of health conditions. This practice is unavailable in the United States; however, persons can travel to foreign locations to receive injections. Local health departments interviewed the patients, and NYSDOH notified CDC and posted a report on CDC’s Epidemic Information Exchange to solicit additional cases. Clinical and exposure information for each patient was reported to the Robert Koch Institute in Germany, which forwarded the information to local health authorities. A Canada resident who also received live cell therapy in May 2014 was diagnosed with Q fever in July 2014. Clinicians should be aware of health risks, such as Q fever and other zoonotic diseases, among patients with a history of receiving treatment with live cell therapy products.

  6. Quasi bound states in the continuum with few unit cells of photonic crystal slab

    DEFF Research Database (Denmark)

    Taghizadeh, Alireza; Chung, Il-Sug

    2017-01-01

    Bound states in the continuum (BICs) in photonic crystal slabs represent the resonances with an infinite quality (Q)-factor, occurring above the light line for an infinitely periodic structure. We show that a set of BICs can turn into quasi-BICs with a very high Q-factor even for two or three unit...

  7. Development of a unit suitable for corrosion monitoring in district heating systems. Experiences with the LOCOR-cell test method

    DEFF Research Database (Denmark)

    Andersen, Asbjørn; Hilbert, Lisbeth Rischel

    2004-01-01

    the purpose, background and gained results of one of the used monitoring techniques, the crevice corrosion measurements obtained by the LOCOR-Cell„§. The crevice corrosion cell was developed by FORCE Technology in a previous district heating project financed by Nordic Industrial Fund (1)(2). Results from...... in 6 pressurised circulating heating systems and in one cooling system. 7 different corrosion monitoring methods have been used to study corrosion rates and types in dependency of water chemistry. This paper describes the design of the by-pass unit including water analysis methods. It also describes...... other used corrosion monitoring methods in the project are described elsewhere (3) and (4). For future district heating corrosion monitoring the by-pass unit can be recommended for permanent installation and the two methods high sensitive ER-technique (Metricorr) and the LOCOR-Cell„§ (FORCE Technology...

  8. Development of a unit suitable for corrosion monitoring in district heating systems. Experiences with the LOCOR-cell test method

    DEFF Research Database (Denmark)

    Andersen, Asbjørn; Hilbert, Lisbeth Rischel

    2004-01-01

    the purpose, background and gained results of one of the used monitoring techniques, the crevice corrosion measurements obtained by the LOCOR-Cell„§. The crevice corrosion cell was developed by FORCE Technology in a previous district heating project financed by Nordic Industrial Fund (1)(2). Results from...... in 6 pressurised circulating heating systems and in one cooling system. 7 different corrosion monitoring methods have been used to study corrosion rates and types in dependency of water chemistry. This paper describes the design of the by-pass unit including water analysis methods. It also describes...... other used corrosion monitoring methods in the project are described elsewhere (3) and (4). For future district heating corrosion monitoring the by-pass unit can be recommended for permanent installation and the two methods high sensitive ER-technique (Metricorr) and the LOCOR-Cell„§ (FORCE Technology...

  9. Heterodimeric barnase-barstar vaccine molecules: influence of one versus two targeting units specific for antigen presenting cells.

    Directory of Open Access Journals (Sweden)

    Heidi Cecilie Larsen Spång

    Full Text Available It is known that targeting of antigen to antigen presenting cells (APC increases immune responses. However, it is unclear if more than one APC-specific targeting unit in the antigenic molecule will increase responses. To address this issue, we have here made heterodimeric vaccine molecules that each express four different fusion subunits. The bacterial ribonuclease barnase and its inhibitor barstar interact with high affinity, and the barnase-barstar complex was therefore used as a dimerization unit. Barnase and barstar were fused N-terminally with single chain fragment variable (scFvs targeting units specific for either MHC class II molecules on APC or the hapten 5-iodo-4-hydroxy-3-nitrophenylacetyl (NIP. C-terminal antigenic fusions were either the fluorescent protein mCherry or scFv(315 derived from myeloma protein M315. The heterodimeric vaccine molecules were formed both in vitro and in vivo. Moreover, the four different fused moieties appeared to fold correctly since they retained their specificity and function. DNA vaccination with MHC class II-targeted vaccine induced higher mCherry-specific IgG1 responses compared to non-targeted control. Since mCherry and MHC class II are in trans in this heterodimer, this suggests that heterodimeric proteins are formed in vivo without prior protein purification. Surprisingly, one targeting moiety was sufficient for the increased IgG1 response, and addition of a second targeting moiety did not increase responses. Similar results were found in in vitro T cell assays; vaccine molecules with one targeting unit were as potent as those with two. In combination with the easy cloning strategy, the heterodimeric barnase-barstar vaccine molecule could provide a flexible platform for development of novel DNA vaccines with increased potency.

  10. A tale of two neglected systems - structure and function of the thin- and thick-walled sieve tubes in monocotyledonous leaves.

    Directory of Open Access Journals (Sweden)

    Ted eBotha

    2013-08-01

    Full Text Available There is a large body of information relating to the ontogeny, development and the vasculature of eudicotyledonous leaves. However there is less information available concerning the vascular anatomy of monocotyledonous leaves. This is surprising, given that there are two uniquely different phloem systems present in large groups such as grasses and sedges. Monocotyledonous leaves contain marginal, large, intermediate and small longitudinal veins that are interconnected by numerous transverse veins. The longitudinal veins contain two metaphloem sieve tube types, which, based upon their ontogeny and position within the phloem, are termed early (thin-walled and late (thick-walled sieve tubes. Early metaphloem comprises sieve tubes, companion cells and vascular parenchyma cells, whilst the late metaphloem, contains thick-walled sieve tubes that lack companion cells. Thick-walled sieve tubes are generally adjacent to, or no more than one cell removed from the metaxylem. Unlike thin-walled sieve tube-companion cell complexes, thick-walled sieve tubes are connected to parenchyma by pore-plasmodesma units and are generally symplasmically isolated from the thin walled sieve tubes. This paper addresses key structural and functional differences between thin- and thick-walled sieve tubes and explores the unique advantages of alternate transport strategies that this 5 to 7 million year old dual system may offer. It would seem that these two systems may enhance, add to, or play a significant role in increasing the efficiency of solute retrieval as well as of assimilate transfer.

  11. Inter-relationships between single carbon units' metabolism and resting energy expenditure in weight-losing patients with small cell lung cancer. Effects of methionine supply and chemotherapy

    DEFF Research Database (Denmark)

    Sengeløv, H; Hansen, O P; Simonsen, L;

    1994-01-01

    The one-carbon unit metabolism was investigated in 8 weight-losing patients with small cell carcinoma of the lung (SCLC). At diagnosis, 6 of the 8 patients had elevated formiminoglutamic acid (FIGLU) excretion after a histidine load, suggesting a lack of one-carbon units. In accordance, a signifi...

  12. Light transmittance of zirconia as a function of thickness and microhardness of resin cements under different thicknesses of zirconia

    OpenAIRE

    Cekic Nagas, Isil; Egilmez,Ferhan; Ergün, Gülfem; Kaya, Bekir-Murat

    2013-01-01

    Objective: The objective of this study was to compare microhardness of resin cements under different thicknesses of zirconia and the light transmittance of zirconia as a function of thickness. Study design: A total of 126 disc-shaped specimens (2 mm in height and 5 mm in diameter) were prepared from dual-cured resin cements (RelyX Unicem, Panavia F and Clearfil SA cement). Photoactivation was performed by using quartz tungsten halogen and light emitting diode light curing units under differen...

  13. Quantification of in situ temperature measurements on a PBI-based high temperature PEMFC unit cell

    DEFF Research Database (Denmark)

    Lebæk, Jesper; Ali, Syed Talat; Møller, Per

    2010-01-01

    The temperature is a very important operating parameter for all types of fuel cells. In the present work distributed in situ temperature measurements are presented on a polybenzimidazole based high temperature PEM fuel cell (HT-PEM). A total of 16 T-type thermocouples were embedded on both...... sensors showed minimal influence on cell performance, this difference seen in performance is believed to be caused by different bipolar plate materials. The measurement method is suitable for obtaining detailed data for validation of computational models, moreover the results indicate that the method can...

  14. Logistics and Capability Implications of a Bradley Fighting Vehicle with a Fuel Cell Auxiliary Power Unit

    Science.gov (United States)

    2003-10-13

    Husted, John MacBain Delphi Corporation Heather McKee US Army TACOM Copyright © 2003 SAE International ABSTRACT Modern military ground vehicles are...WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Delphi Corporation,5725 Delphi Drive,Troy,Mi,48098 8. PERFORMING ORGANIZATION... injector hardware change. A single, 28V, 400A permanent-magnet direct current (DC) generator is driven by a power take off (PTO) directly connected to

  15. Evaluation of eicosanoid concentrations in stored units of canine packed red blood cells.

    Science.gov (United States)

    Blake, Rachel R; Lee, Jung Hwa; Ross, Matt K; Archer, Todd M; Wills, Robert W; Mackin, Andrew J; Thomason, John M

    2017-01-15

    OBJECTIVE To evaluate eicosanoid concentrations in freshly prepared canine packed RBCs (PRBCs) and to assess changes in eicosanoid concentrations in PRBC units over time during storage and under transfusion conditions. DESIGN Prospective study. SAMPLE 25 plasma samples from 14 healthy Greyhounds. PROCEDURES Plasma samples were obtained during PRBC preparation (donation samples), and the PRBC units were then stored at 4°C until used for transfusion (≤ 21 days later; n = 17) or mock transfusion if expired (22 to 24 days later; 8). Immediately prior to use, 100 mL of saline (0.9% NaCl) solution was added to each unit and a pretransfusion sample was collected. A posttransfusion sample was collected after transfusion or mock transfusion. Concentrations of arachidonic acid, prostaglandin (PG) F2α, PGE2, PGD2, thromboxane B2, 6-keto-PGF1α, and leukotriene B4 were measured by liquid chromatography-mass spectrometry and analyzed statistically. RESULTS Median arachidonic acid concentration was significantly decreased in posttransfusion samples, compared with the concentration in donation samples. Median PGF2α, 6-keto-PGF1α, and leukotriene B4 concentrations were significantly increased in pretransfusion samples, compared with those in donation samples. Median PGF2α, thromboxane B2, and 6-keto-PGF1α concentrations were significantly increased in posttransfusion samples, compared with those in pretransfusion samples. Duration of PRBC storage had significant associations with pretransfusion and posttransfusion arachidonic acid and thromboxane B2 concentrations. CONCLUSIONS AND CLINICAL RELEVANCE Concentrations of several proinflammatory eicosanoids increased in PRBC units during storage, transfusion, or both. Accumulation of these products could potentially contribute to adverse transfusion reactions, and investigation of the potential association between eicosanoid concentrations in PRBCs and the incidence of transfusion reactions in dogs is warranted.

  16. Trapped-Mode Resonance Regime of Thin Microwave Electromagnetic Arrays with Two Concentric Rings in Unit Cell

    Directory of Open Access Journals (Sweden)

    M. N. Kawakatsu

    2011-01-01

    Full Text Available We present a theoretical study of reflection and transmission characteristics of a microwave planar array on a thin dielectric substrate with unit cell made of two concentric rings. This array possesses high quality factor transmission resonance with polarization insensitivity for normally incident plane wave. This resonance is defined by the trapped-mode regime. We show that for oblique incidence, there are some differences in characteristics of the array and a small change in quality factor of the trapped-mode resonance.

  17. Comparison of fuel-cell and diesel integrated energy systems and a conventional system for a 500-unit apartment

    Science.gov (United States)

    Simons, S. N.; Maag, W. L.

    1978-01-01

    The electrical and thermal energy utilization efficiencies of a 500 unit apartment complex are analyzed and compared for each of three energy supply systems. Two on-site integrated energy systems, one powered by diesel engines and the other by phosphoric-acid fuel cells were compared with a conventional system which uses purchased electricity and on-site boilers for heating. All fuels consumed on-site are clean, synthetic fuels (distillate fuel oil or pipeline quality gas) derived from coal. Purchased electricity was generated from coal at a central station utility. The relative energy consumption and economics of the three systems are analyzed and compared.

  18. Huge thick conglomerate movement induced by full thick longwall mining huge thick coal seam

    Institute of Scientific and Technical Information of China (English)

    Ma Liqiang; Qiu Xiaoxiang; Dong Tao; Zhang Jixiong; Huang Yanli

    2012-01-01

    A discrete elemental method was used to study the thickness of conglomerate layer in a full thick seam mining activities under the influence of the law,pointing out the thickness of the conglomerate at different seam mining,and during the destruction and instability of existing state of laws.At 21141 thick seam mining,the face toward the direction of separation between the thick layer of conglomerate rock and the next bit after reaching its maximum capacity due to pull from the bottom of the plastic zone,formed a stratified and hierarchical down collapse.The shape of caving area is a "triangular block",the length of the plastic zone and face advancement from the linear fit between the height of the plastic zone and the advancing face is a quadratic function of distance,while the top layer of thick gravel layer is the overall bending subsidence trend.Tilting the direction of the face,a thick gob of collapsed conglomerate layer is formed in the coal gob entity on both sides of the thick conglomerate at the top of the overall fracture morphology performance,thus forming a mutual extrusion of articulated block structure.The instability,separation and balance of the thick conglomerate layer in the hinged block stope stress leads to abnormal occurrence of rock burst induced by face as the major factor in the accident.This research reveals the form of stress distribution in the destroyed layer of the thick conglomerate rock,analyzes the stope law of coupling for the pressure burst behavior law for the mining work face,and the choice of preventive measures to provide a theoretical basis and implementation.

  19. Oil and Gas Exploration and Production in the United States Shown as Quarter-Mile Cells

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A cells polygon feature class was created by the U.S. Geological Survey (USGS) to illustrate the degree of exploration, type of production, and distribution of...

  20. Fuel cell programs in the United States for stationary power applications

    Energy Technology Data Exchange (ETDEWEB)

    Singer, M.

    1996-04-01

    The Department of Energy (DOE), Office of Fossil Energy, is participating with the private sector in sponsoring the development of molten carbonate fuel cell (MCFC) and solid oxide fuel cell (SOFC) technologies for application in the utility, commercial and industrial sectors. Phosphoric acid fuel cell (PAFC) development was sponsored by the Office of Fossil Energy in previous years and is now being commercialized by the private sector. Private sector participants with the Department of Energy include the Electric Power Research Institute (EPRI), the Gas Research institute (GRI), electric and gas utilities, universities, manufacturing companies and their suppliers. through continued government and private sector support, fuel cell systems are emerging power generation technologies which are expected to have significant worldwide impacts. An industry with annual sales of over a billion dollars is envisioned early in the 21st century. PAFC power plants have begun to enter the marketplace and MCFC and SOFC power plants are expected to be ready to enter the marketplace in the late 1990s. In support of the efficient and effective use of our natural resources, the fuel cell program seeks to increase energy efficiency and economic effectiveness of power generation. This is to be accomplished through effectiveness of power generation. This is accomplished through the development and commercialization of cost-effective, efficient and environmentally desirable fuel cell systems which will operate on fossil fuels in multiple and end use sectors.

  1. Temperature-dependent haemolytic propensity of CPDA-1 stored red blood cells vs whole blood - Red cell fragility as donor signature on blood units.

    Science.gov (United States)

    Tzounakas, Vassilis L; Anastasiadi, Alkmini T; Karadimas, Dimitrios G; Zeqo, Redisa A; Georgatzakou, Hara T; Pappa, Olga D; Papatzitze, Olga A; Stamoulis, Konstantinos E; Papassideri, Issidora S; Antonelou, Marianna H; Kriebardis, Anastasios G

    2017-09-01

    To preserve cellular integrity and avoid bacterial growth, storage and transfer of blood and blood products follow strict guidelines in terms of temperature control. We evaluated the impact of ineligible warming of whole blood donations on the quality of blood components. One-hundred and twenty units of whole blood (WB) from eligible blood donors were collected in CPDA-1 and stored at 4±2 °C. During shipment to the blood processing centre, a gradual warming up to 17 °C was recorded within a period of less than eight hours. The warmed units were processed to packed red blood cells (PRBCs) or stored as WB units at 4±2 °C. In-bag haemolysis, osmotic fragility (mean corpuscular fragility, MCF) and bacterial growth were assessed in blood and blood components throughout the storage period. Normal basal and early storage levels of haemolysis were recorded in both PRBC and WB units. Thereafter, PRBCs exhibited higher average in-bag haemolysis and MCF index compared to the WB units throughout the storage. Moreover, 14.3 and 52.4% of the PRBC units exceeded the upper permissible limit of 0.8% haemolysis at the middle (1.220±0.269%) or late (1.754±0.866%) storage period, respectively. MCF index was similar in all PRBCs at the middle of storage but significantly lower in the non-haemolysed compared to the haemolysed units of PRBCs on the last days. The fragility of stored RBCs was proportional to the donor-related values of day 2 samples (r=0.861, punits of PRBCs. Transient, gradient warming of whole blood from 4 to 17 °C led to increased incidence of in-bag haemolysis in PRBC but not in WB units. Haemolysis is a multi-parametric phenotype of stored blood, and MCF is a donor-related and highly dynamic measure that can, in part, predict the storage lesion.

  2. The changing pattern of stem cell markers of sweat gland in deep partial-thickness burn wound%深Ⅱ度烧伤创面汗腺干细胞标志物的变化规律

    Institute of Scientific and Technical Information of China (English)

    姜笃银; 宗宪磊; 付小兵; 王魏; 单菲

    2009-01-01

    目的 了解深Ⅱ度烧伤创面愈合过程中汗腺上皮细胞增殖并向表皮细胞转化的规律,探讨其机制.方法 选择2004年1月-2007年12月,江苏省泰州市第四人民医院和山东大学第二医院收治的四肢与躯干烧伤患者28例.收集患者深Ⅱ度烧伤创面组织标本37块、浅Ⅱ度烧伤创面组织标本21块、正常皮肤标本10块.采用免疫组织化学双染色法,观察细胞角蛋白10(CK10)、CK14、CK19、bel-2和P63在深、浅Ⅱ度烧伤创面及正常皮肤汗腺分泌部上皮细胞中的表达情况.结果 正常皮肤汗腺分泌部上皮细胞中等强度表达CK19、CK14和CK10,基底层肌上皮细胞微弱表达P63和CK14,CK10表达阳性的终末分化细胞不表达bcl-2和P63.浅Ⅱ度烧伤创面修复过程中,其汗腺分泌部结构及上述蛋白表达未见异常.深Ⅱ度烧伤后7 d创面汗腺分泌部上皮细胞P63和bcl-2表达增强;伤后8~10 d创面基底细胞增殖、迁移和鳞状上皮化,形成bcl-2、P63、CK19和CK14表达强阳性的实心岛状上皮结构,并随肉芽组织向创面浅层迁移,经鳞状上皮增殖完成创面再上皮化.深Ⅱ度烧伤创面愈合后13~30 d,超常增殖的表皮基底层和基底上层细胞仍强烈表达bcl-2、CK14、CK19和P63. 结论干细胞和短暂扩充细胞逆分化过程导致上皮生长滞后和肉芽组织过度增殖,这种失衡现象可能是导致深Ⅱ度烧伤创面修复失控的重要机制之一.%Objective To investigate the rules of proliferation of epithelial cells of sweat glands in deep partial-thickness burn wound and its transdifferentiation towards epidermal cells during healing process to explore its mechanisms. Methods Twenty-eight patients with limbs and trunk burn hospitalized in the Fourth People's Hospital of Taizhou City of Jiangsu Province and the Second itospital of Shandong University from January 2004 to December 2007 were enrolled in the study. Tissue samples of deep partial-thickness

  3. Engineering aspects and hardware verification of a volume producable solid oxide fuel cell stack design for diesel auxiliary power units

    Science.gov (United States)

    Stelter, Michael; Reinert, Andreas; Mai, Björn Erik; Kuznecov, Mihail

    A solid oxide fuel cell (SOFC) stack module is presented that is designed for operation on diesel reformate in an auxiliary power unit (APU). The stack was designed using a top-down approach, based on a specification of an APU system that is installed on board of vehicles. The stack design is planar, modular and scalable with stamped sheet metal interconnectors. It features thin membrane electrode assemblies (MEAs), such as electrolyte supported cells (ESC) and operates at elevated temperatures around 800 °C. The stack has a low pressure drop in both the anode and the cathode to facilitate a simple system layout. An overview of the technical targets met so far is given. A stack power density of 0.2 kW l -1 has been demonstrated in a fully integrated, thermally self-sustaining APU prototype running with diesel and without an external water supply.

  4. Characterization of immune cells and cytokine localization in the rat utero-placental unit mid- to late gestation.

    Science.gov (United States)

    Tessier, Daniel R; Raha, Sandeep; Holloway, Alison C; Yockell-Lelièvre, Julien; Tayade, Chandrakant; Gruslin, Andrée

    2015-08-01

    The success of pregnancy is dependent on the precise regulation of the immune response within the utero-placental environment. Rats are beginning to be widely used as a model for human immune-related pregnancy complications. However, our knowledge of immune cells and cytokine localization in the rat utero-placental tissue is limited. The current study aimed to localize the immune cell populations, including uterine natural killer (uNK) cells, neutrophils, and macrophages within the rat utero-placental unit at two crucial gestational ages, gestational days 15.5 and 18.5. In addition, we characterized the distribution of the cytokines TNFα, IFNγ, and IL-10 in the utero-placental regions at both the above-mentioned gestational ages. Our study has demonstrated co-localization TNFα and IFNγ with uNK cells in perivascular regions of the rat mesometrial triangle at both gestational ages. Neutrophils and IL-10-positive cells were localized at the maternal-fetal interface and in the spiral artery lumen of the rat mesometrial triangle at both gestational ages. TNFα and IL-10 demonstrated a temporal change in the localization from GD15.5 to GD18.5, which coincides with the leading edge of trophoblast invasion into the mesometrial triangle. The current study furthers our knowledge of the localization of uterine immune cells and relevant cytokines, and provides a base from which to research the function of these immune cells and cytokines during rat pregnancy as a model to study human immune-related pregnancy complications.

  5. Peripapillary choroidal thickness in childhood.

    Science.gov (United States)

    Read, Scott A; Alonso-Caneiro, David; Vincent, Stephen J; Collins, Michael J

    2015-06-01

    Changes in the thickness of the invivo peripapillary choroid have been documented in a range of ocular conditions in adults; however, choroidal thickness in the peripapillary region of children has not been examined in detail. This study therefore aimed to investigate the thickness of the peripapillary choroid and the overlying retinal nerve fibre layer (RNFL) in a population of normal children with a range of refractive errors. Ninety-three children (37 myopes and 56 non-myopes) aged between 11 and 16 years, had measurements of peripapillary choroidal and RNFL thickness derived from enhanced depth imaging optical coherence tomography images (EDI-OCT, Heidelberg Spectralis). The average thickness was determined in a series of five 0.25 mm width concentric annuli (each divided into 8 equal sized 45° sectors) centred on the optic nerve head boundary, accounting for individual ocular magnification factors and the disc-fovea angle. Significant variations in peripapillary choroidal thickness were found to occur with both annulus location (p choroid (mean 77 ± 16 μm) and the outermost annulus, the thickest choroid (191 ± 52 μm). The choroid was thinnest inferior to the optic nerve head (139 ± 38 μm) and was thickest in the superior temporal sector (157 ± 40 μm). Significant differences in the distribution of choroidal thickness were also associated with myopia, with myopic children having significantly thinner choroids in the inner and outer annuli of the nasal and temporal sectors respectively (p thickness also varied significantly with annulus location and sector (p thickness distribution associated with refractive error. This study establishes the normal variations in the thickness of the peripapillary choroid with radial distance and azimuthal angle from the optic nerve head boundary. A significant thinning of the peripapillary choroid associated with myopia in childhood was also observed in both nasal and temporal regions. The changes in peripapillary RNFL

  6. Global reorganisation of cis-regulatory units upon lineage commitment of human embryonic stem cells.

    Science.gov (United States)

    Freire-Pritchett, Paula; Schoenfelder, Stefan; Várnai, Csilla; Wingett, Steven W; Cairns, Jonathan; Collier, Amanda J; García-Vílchez, Raquel; Furlan-Magaril, Mayra; Osborne, Cameron S; Fraser, Peter; Rugg-Gunn, Peter J; Spivakov, Mikhail

    2017-03-23

    Long-range cis-regulatory elements such as enhancers coordinate cell-specific transcriptional programmes by engaging in DNA looping interactions with target promoters. Deciphering the interplay between the promoter connectivity and activity of cis-regulatory elements during lineage commitment is crucial for understanding developmental transcriptional control. Here, we use Promoter Capture Hi-C to generate a high-resolution atlas of chromosomal interactions involving ~22,000 gene promoters in human pluripotent and lineage-committed cells, identifying putative target genes for known and predicted enhancer elements. We reveal extensive dynamics of cis-regulatory contacts upon lineage commitment, including the acquisition and loss of promoter interactions. This spatial rewiring occurs preferentially with predicted changes in the activity of cis-regulatory elements and is associated with changes in target gene expression. Our results provide a global and integrated view of promoter interactome dynamics during lineage commitment of human pluripotent cells.

  7. Altered spatial arrangement of layer V pyramidal cells in the mouse brain following prenatal low-dose X-irradiation. A stereological study using a novel three-dimensional analysis method to estimate the nearest neighbor distance distributions of cells in thick sections.

    Science.gov (United States)

    Schmitz, Christoph; Grolms, Norman; Hof, Patrick R; Boehringer, Robert; Glaser, Jacob; Korr, Hubert

    2002-09-01

    Prenatal X-irradiation, even at doses <1 Gy, can induce spatial disarray of neurons in the brains of offspring, possibly due to disturbed neuronal migration. Here we analyze the effects of prenatal low-dose X-irradiation using a novel stereological method designed to investigate the three-dimensional (3D) spatial arrangement of neurons in thick sections. Pregnant mice were X-irradiated with 50 cGy on embryonic day 13 or were sham-irradiated. The right brain halves of their 180-day-old offspring were dissected into entire series of 150 microm thick frontal cryostat sections and stained with gallocyanin. Approximately 700 layer V pyramidal cells per animal were sampled in a systematic-random manner in the middle of the section's thickness. The x-y-z coordinates of these 'parent neurons' were recorded, as well as of all neighboring (up to 10) 'offspring neurons' close to each 'parent neuron'. From these data, the nearest neighbor distance (NND) distributions for layer V pyramidal cells were calculated. Using this novel 3D analysis method, we found that, in comparison to controls, prenatal X-irradiation had no effect on the total neuron number, but did cause a reduction in the mean volume of layer V by 26.5% and a more dispersed spatial arrangement of these neurons. Considering the recent literature, it seems reasonable to consider abnormal neuronal migration as the potential basic cause of this finding.

  8. Hydrogeologic unit flow characterization using transition probability geostatistics.

    Science.gov (United States)

    Jones, Norman L; Walker, Justin R; Carle, Steven F

    2005-01-01

    This paper describes a technique for applying the transition probability geostatistics method for stochastic simulation to a MODFLOW model. Transition probability geostatistics has some advantages over traditional indicator kriging methods including a simpler and more intuitive framework for interpreting geologic relationships and the ability to simulate juxtapositional tendencies such as fining upward sequences. The indicator arrays generated by the transition probability simulation are converted to layer elevation and thickness arrays for use with the new Hydrogeologic Unit Flow package in MODFLOW 2000. This makes it possible to preserve complex heterogeneity while using reasonably sized grids and/or grids with nonuniform cell thicknesses.

  9. The heterogeneous ice shell thickness of Enceladus

    Science.gov (United States)

    Lucchetti, Alice; Pozzobon, Riccardo; Mazzarini, Francesco; Cremonese, Gabriele; Massironi, Matteo

    2016-10-01

    Saturn's moon Enceladus is the smallest Solar System body that presents an intense geologic activity on its surface. Plumes erupting from Enceladus' South Polar terrain (SPT) provide direct evidence of a reservoir of liquid below the surface. Previous analysis of gravity data determined that the ice shell above the liquid ocean must be 30-40 km thick from the South Pole up to 50° S latitude (Iess et al., 2014), however, understand the global or regional nature of the ocean beneath the ice crust is still challenging. To infer the thickness of the outer ice shell and prove the global extent of the ocean, we used the self-similar clustering method (Bonnet et al., 2001; Bour et al., 2002) to analyze the widespread fractures of the Enceladus's surface. The spatial distribution of fractures has been analyzed in terms of their self-similar clustering and a two-point correlation method was used to measure the fractal dimension of the fractures population (Mazzarini, 2004, 2010). A self-similar clustering of fractures is characterized by a correlation coefficient with a size range defined by a lower and upper cut-off, that represent a mechanical discontinuity and the thickness of the fractured icy crust, thus connected to the liquid reservoir. Hence, this method allowed us to estimate the icy shell thickness values in different regions of Enceladus from SPT up to northern regions.We mapped fractures in ESRI ArcGis environment in different regions of the satellite improving the recently published geological map (Crow-Willard and Pappalardo, 2015). On these regions we have taken into account the fractures, such as wide troughs and narrow troughs, located in well-defined geological units. Firstly, we analyzed the distribution of South Polar Region fracture patterns finding an ice shell thickness of ~ 31 km, in agreement with gravity measurements (Iess et al., 2014). Then, we applied the same approach to other four regions of the satellite inferring an increasing of the ice

  10. A review of high-temperature polymer electrolyte membrane fuel-cell (HT-PEMFC)-based auxiliary power units for diesel-powered road vehicles

    Science.gov (United States)

    Liu, Yongfeng; Lehnert, Werner; Janßen, Holger; Samsun, Remzi Can; Stolten, Detlef

    2016-04-01

    This paper presents an extensive review of research on the development of auxiliary power units with enhanced reformate tolerance for high temperature polymer electrolyte membrane fuel cells (HT-PEMFCs). Developments in diesel reforming for fuel cells as auxiliary power units (APUs), single fuel cells and stacks and systems are outlined in detail and key findings are presented. Summaries of HT-PEMFC APU applications and start-up times for HT-PEMFC systems are then given. A summary of cooling HT-PEMFC stacks using a classic schematic diagram of a 24-cell HT-PEMFC stack, with a cooling plate for every third cell, is also presented as part of a stack analysis. Finally, a summary of CO tolerances for fuel cells is given, along with the effects of different CO volume fractions on polarization curves, the fraction of CO coverage, hydrogen coverage, anode overpotential and cell potential.

  11. Electrochemical characterization of a polybenzimidazole-based high temperature proton exchange membrane unit cell

    DEFF Research Database (Denmark)

    Jespersen, Jesper Lebæk; Schaltz, Erik; Kær, Søren Knudsen

    2009-01-01

    Equivalent Circuit (EC) modeling key parameters, such as the membrane resistance, charge transfer resistance and gas transfer resistance are identified, however the physical interpretation of the parameters derived from EC's are doubtful as discussed in this paper. The EC model proposed, which is a modified...... Randles circuit, provides a reasonably good fit at all the conditions tested. The measurements reveal that the cell temperature is an important parameter, which influences the cell performance significantly, especially the charge transfer resistance proved to be very temperature dependent. The transport...... of oxygen to the Oxygen Reduction Reaction (ORR) likewise has a substantial effect on the impedance spectra, results showed that the gas transfer resistance has an exponential-like dependency on the air stoichiometry. Based on the present results and results found in recent publications it is still...

  12. Application of multivariate analysis toward biotech processes: case study of a cell-culture unit operation.

    Science.gov (United States)

    Kirdar, Alime Ozlem; Conner, Jeremy S; Baclaski, Jeffrey; Rathore, Anurag S

    2007-01-01

    This paper examines the feasibility of using multivariate data analysis (MVDA) for supporting some of the key activities that are required for successful manufacturing of biopharmaceutical products. These activities include scale-up, process comparability, process characterization, and fault diagnosis. Multivariate data analysis and modeling were performed using representative data from small-scale (2 L) and large-scale (2000 L) batches of a cell-culture process. Several input parameters (pCO2, pO2, glucose, pH, lactate, ammonium ions) and output parameters (purity, viable cell density, viability, osmolality) were evaluated in this analysis. Score plots, loadings plots, and VIP plots were utilized for assessing scale-up and comparability of the cell-culture process. Batch control charts were found to be useful for fault diagnosis during routine manufacturing. Finally, observations made from reviewing VIP plots were found to be in agreement with conclusions from process characterization studies demonstrating the effectiveness of MVDA as a tool for extracting process knowledge.

  13. Space Station Biological Research Project (SSBRP) Cell Culture Unit (CCU) and incubator for International Space Station (ISS) cell culture experiments.

    Science.gov (United States)

    Vandendriesche, Donald; Parrish, Joseph; Kirven-Brooks, Melissa; Fahlen, Thomas; Larenas, Patricia; Havens, Cindy; Nakamura, Gail; Sun, Liping; Krebs, Chris; de Luis, Javier; Vunjak-Novakovic, Gordana; Searby, Nancy D

    2004-03-01

    The CCU and Incubator are habitats under development by SSBRP for gravitational biology research on ISS. They will accommodate multiple specimen types and reside in either Habitat Holding Racks, or the Centrifuge Rotor, which provides selectable gravity levels of up to 2 g. The CCU can support multiple Cell Specimen Chambers, CSCs (18, 9 or 6 CSCs; 3, 10 or 30 mL in volume, respectively). CSCs are temperature controlled from 4-39 degrees C, with heat shock to 45 degrees C. CCU provides automated nutrient supply, magnetic stirring, pH/O2 monitoring, gas supply, specimen lighting, and video microscopy. Sixty sample containers holding up to 2 mL each, stored at 4-39 degrees C, are available for automated cell sampling, subculture, and injection of additives and fixatives. CSCs, sample containers, and fresh/spent media bags are crew-replaceable for long-term experiments. The Incubator provides a 4-45 degrees C controlled environment for life science experiments or storage of experimental reagents. Specimen containers and experiment unique equipment are experimenter-provided. The Specimen Chamber exchanges air with ISS cabin and has 18.8 liters of usable volume that can accommodate six trays and the following instrumentation: five relocatable thermometers, two 60 W power outlets, four analog ports, and one each relative humidity sensor, video port, ethernet port and digital input/output port.

  14. Tube wall thickness measurement apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Lagasse, P.R.

    1985-06-21

    An apparatus for measuring the thickness of a tube's wall for the tube's entire length and radius by determining the deviation of the tube wall thickness from the known thickness of a selected standard item. The apparatus comprises a base and a first support member having first and second ends. The first end is connected to the base and the second end is connected to a spherical element. A second support member is connected to the base and spaced apart from the first support member. A positioning element is connected to and movable relative to the second support member. An indicator is connected to the positioning element and is movable to a location proximate the spherical element. The indicator includes a contact ball for first contacting the selected standard item and holding it against the spherical element. The contact ball then contacts the tube when the tube is disposed about the spherical element. The indicator includes a dial having a rotatable needle for indicating the deviation of the tube wall thickness from the thickness of the selected standard item.

  15. Tube wall thickness measurement apparatus

    Science.gov (United States)

    Lagasse, P.R.

    1985-06-21

    An apparatus for measuring the thickness of a tube's wall for the tube's entire length and radius by determining the deviation of the tube wall thickness from the known thickness of a selected standard item. The apparatus comprises a base and a first support member having first and second ends. The first end is connected to the base and the second end is connected to a spherical element. A second support member is connected to the base and spaced apart from the first support member. A positioning element is connected to and movable relative to the second support member. An indicator is connected to the positioning element and is movable to a location proximate the spherical element. The indicator includes a contact ball for first contacting the selected standard item and holding it against the spherical element. The contact ball then contacts the tube when the tube is disposed about the spherical element. The indicator includes a dial having a rotatable needle for indicating the deviation of the tube wall thickness from the thickness of the selected standard item.

  16. Tube wall thickness measurement apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Lagasse, Paul R. (Santa Fe, NM)

    1987-01-01

    An apparatus for measuring the thickness of a tube's wall for the tube's entire length and circumference by determining the deviation of the tube wall thickness from the known thickness of a selected standard item. The apparatus comprises a base and a first support member having first and second ends. The first end is connected to the base and the second end is connected to a spherical element. A second support member is connected to the base and spaced apart from the first support member. A positioning element is connected to and movable relative to the second support member. An indicator is connected to the positioning element and is movable to a location proximate the spherical element. The indicator includes a contact ball for first contacting the selected standard item and holding it against the spherical element. The contact ball then contacts the tube when the tube is disposed about the spherical element. The indicator includes a dial having a rotatable needle for indicating the deviation of the tube wall thickness from the thickness of the selected standard item.

  17. Engineering thick tissues - the vascularisation problem

    Directory of Open Access Journals (Sweden)

    H C H Ko

    2007-07-01

    Full Text Available The ability to create thick tissues is a major tissue engineering challenge, requiring the development of a suitable vascular supply. Current trends are seeing the utilization of cells seeded into hybrid matrix/scaffold systems to create in vitro vascular analogues. Approaches that aim to create vasculature in vitro include the use of biological extracellular matrices such as collagen hydrogels, porous biodegradable polymeric scaffolds with macro- and micro-lumens and micro-channels, co-culture of cells, incorporation of growth factors, culture in dynamic bioreactor environments, and combinations of these. Of particular interest are those approaches that aim to create bioengineered tissues in vitro that can be readily connected to the host's vasculature following implantation in order to maintain cell viability.

  18. Increasing the repeating units of ethylene glycol-based dimethacrylates directed toward reduced oxidative stress and co-stimulatory factors expression in human monocytic cells.

    Science.gov (United States)

    Tamura, Atsushi; Fukumoto, Izumi; Yui, Nobuhiko; Matsumura, Mitsuaki; Miura, Hiroyuki

    2015-03-01

    The ethylene glycol-based dimethacrylates are commonly used in biomaterials and dental restorative materials as a cross-linking agent. In this study, toxic effect of triethylene glycol dimethacrylate (TEGDMA) and poly(ethylene glycol) dimethacrylates (PEG-DMAs) with various ethylene glycol repeating units was investigated in terms of cytotoxicity, oxidative stress, and the expression of co-stimulatory factors in human leukemia cell line (THP-1 cells) to verify the effect of ethylene glycol repeating units. Note that the 1-octanol/water partition coefficient of PEG-based dimethacrylates decreased with increasing the ethylene glycol repeating units, indicating that the hydrophilicity of PEG-DMAs increased with ethylene glycol repeating units. The toxic effect of PEG-DMAs such as cytotoxicity, oxidative stress, and the expression of CD86 in treated THP-1 cells are reduced with increasing the ethylene glycol repeating units in PEG-DMAs. However, the expression of CD54 in treated THP-1 cells was not influenced with the ethylene glycol repeating units and the maximal expression level of CD54 was observed at the concentration range of 2-4 mM for all samples. Accordingly, hydrophilic character of PEG-DMAs with long ethylene glycol chains definitely alleviates the some toxic aspect of PEG-based DMAs. This finding would provide important insight into the design of new biomaterials and dental materials with superior biocompatibility. © 2014 Wiley Periodicals, Inc.

  19. Synthesis of a new conjugated polymer composed of pyrene and bithiophene units for organic solar cells.

    Science.gov (United States)

    Lee, Sun-Young; Jung, Choong-Hwa; Kang, Jun; Kim, Hee-Joon; Shin, Won Suk; Yoon, Sung Cheol; Moon, Sang-Jin; Lee, Changjin; Hwang, Do-Hoon

    2011-05-01

    An alternating conjugated copolymer composed of pyrene and bithiophene units, poly(DHBT-alt-PYR) has been synthesized. The synthesized polymer was found to exhibit good solution processibility and thermal stability, losing less than 5% of their weight on heating to approximately 370 degrees C. The synthesized polymer showed its maximum absorption and peak PL emission at 401 and 548 nm, respectively. The optical band gap energy of the polymer was determined by absorption onset to be 2.64 eV. Highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels of the polymer was determined to be -5.48 and -2.84 eV by cyclic voltametry (CV) and the optical band gap. The polymer photovoltaic devices were fabricated with a typical sandwich structure of ITO/PEDOT:PSS/active layer/LiF/Al using poly(DHBT-alt-PYR) as an electron donor and C60-PCBM or C70-PCBM as electron acceptors. The open circuit voltage, short circuit current and fill factor of the device using C70-PCBM as an acceptor were 0.75 V, 3.80 mA/cm2 and 0.28, respectively, and the maximum power conversion efficiency of the device was 0.80%.

  20. Thickness dependent structural, magnetic, and electronic properties of the epitaxial films of transparent conducting oxide NiCo2O4

    Science.gov (United States)

    Silwal, Punam; Miao, Ludi; Hu, Jin; Spinu, Leonard; Ho Kim, Dae; Talbayev, Diyar

    2013-09-01

    We present the thickness dependent structural, magnetic, and transport properties of transparent conducting spinel NiCo2O4 thin films on MgAl2O4 (001) substrates. The structural examination of the films reveals that the epitaxial stain is independent of the films' thickness. Electric and magnetic measurements show that the films are metallic with p-type conduction and ferrimagnetic down to 2 unit cells with an enhanced coercive field in the films thinner than 30 unit cells. The low-temperature resistivity data indicate that the observed resistivity minimum results from the disorder-induced quantum interference effects. Our results demonstrate that NiCo2O4 may provide an alternative magnetic conducting medium for spintronics devices.