Minimal genera of open 4-manifolds

OpenAIRE

Gompf, Robert E.

2013-01-01

We study exotic smoothings of open 4-manifolds using the minimal genus function and its analog for end homology. While traditional techniques in open 4-manifold smoothing theory give no control of minimal genera, we make progress by using the adjunction inequality for Stein surfaces. Smoothings can be constructed with much more control of these genus functions than the compact setting seems to allow. As an application, we expand the range of 4-manifolds known to have exotic smoothings (up to ...

Radiological performance of hot water layer system in open pool type reactor

Directory of Open Access Journals (Sweden)

Amr Abdelhady

2013-06-01

Full Text Available The paper presents the calculated dose rate carried out by using MicroShield code to show the importance of hot water layer system (HWL in 22 MW open pool type reactor from the radiation protection safety point of view. The paper presents the dose rate profiles over the pool surface in normal and abnormal operations of HWL system. The results show that, in case of losing the hot water layer effect, the radiation dose rate profiles over the pool surface will increase from values lower than the worker permissible dose limits to values very higher than the permissible dose limits.

Gap opening and tuning in single-layer graphene with combined electric and magnetic field modulation

Institute of Scientific and Technical Information of China (English)

Lin Xin; Wang Hai-Long; Pan Hui; Xu Huai-Zhe

2011-01-01

The energy band structure of single-layer graphene under one-dimensional electric and magnetic field modulation is theoretically investigated. The criterion for bandgap opening at the Dirac point is analytically derived with a two-fold degeneracy second-order perturbation method. It is shown that a direct or an indirect bandgap semiconductor could be realized in a single-layer graphene under some specific configurations of the electric and magnetic field arrangement. Due to the bandgap generated in the single-layer graphene, the Klein tunneling observed in pristine graphene is completely suppressed.

Magnetic trapping of energetic particles on open dayside boundary layer flux tubes

International Nuclear Information System (INIS)

Cowley, S.W.H.; Lewis, Z.V.

1990-01-01

Both simple as well as detailed empirical magnetic models of the Earth's dayside magnetosphere suggest that field lines near the magnetopause boundary in the noon quadrant (∼ 09:00 to ∼ 15:00 M.L.T.) possess an unusual property due to the compressive effect of the impinging solar wind flow, namely that the equatorial region represents a local maximum in the magnetic field strength, and not a minimum as elsewhere in the magnetosphere. In this region the field lines can therefore support two distinct particle populations, those which bounce across the equator between mirror points on either side, and those which are trapped about the off-equatorial field strength minima and are confined to one side of the equator. When these field lines become magnetically open due to the occurrence of magnetic reconnection at the equatorial magnetopause, the former particles will rapidly escape into the magnetosheath by field-aligned flow, while the latter population may be sustained within the boundary layer over many bounce periods, as the flux tubes contract and move tailward. Consequently, trapped distributions of energetic particles may commonly occur on open field lines in the dayside boundary layer in the noon quadrant, particularly at high latitudes. The existence of such particles is thus not an infallible indicator of the presence of closed magnetic field lines in this region. At earlier and later local times, however, the boundary layer field lines revert to possessing a minimum in the field strength at the equator. (author)

36 CFR 4.14 - Open container of alcoholic beverage.

Science.gov (United States)

2010-07-01

... beverage. 4.14 Section 4.14 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR VEHICLES AND TRAFFIC SAFETY § 4.14 Open container of alcoholic beverage. (a) Each person within a..., can or other receptacle containing an alcoholic beverage that is open, or has been opened, or whose...

A high-order doubly asymptotic open boundary for scalar waves in semi-infinite layered systems

International Nuclear Information System (INIS)

Prempramote, S; Song, Ch; Birk, C

2010-01-01

Wave propagation in semi-infinite layered systems is of interest in earthquake engineering, acoustics, electromagnetism, etc. The numerical modelling of this problem is particularly challenging as evanescent waves exist below the cut-off frequency. Most of the high-order transmitting boundaries are unable to model the evanescent waves. As a result, spurious reflection occurs at late time. In this paper, a high-order doubly asymptotic open boundary is developed for scalar waves propagating in semi-infinite layered systems. It is derived from the equation of dynamic stiffness matrix obtained in the scaled boundary finite-element method in the frequency domain. A continued-fraction solution of the dynamic stiffness matrix is determined recursively by satisfying the scaled boundary finite-element equation at both high- and low-frequency limits. In the time domain, the continued-fraction solution permits the force-displacement relationship to be formulated as a system of first-order ordinary differential equations. Standard time-step schemes in structural dynamics can be directly applied to evaluate the response history. Examples of a semi-infinite homogeneous layer and a semi-infinite two-layered system are investigated herein. The displacement results obtained from the open boundary converge rapidly as the order of continued fractions increases. Accurate results are obtained at early time and late time.

Effect of a surface oxide-dispersion-strengthened layer on mechanical strength of zircaloy-4 tubes

Directory of Open Access Journals (Sweden)

Yang-Il Jung

2018-03-01

Full Text Available An oxide-dispersion-strengthened (ODS layer was formed on Zircaloy-4 tubes by a laser beam scanning process to increase mechanical strength. Laser beam was used to scan the yttrium oxide (Y2O3–coated Zircaloy-4 tube to induce the penetration of Y2O3 particles into Zircaloy-4. Laser surface treatment resulted in the formation of an ODS layer as well as microstructural phase transformation at the surface of the tube. The mechanical strength of Zircaloy-4 increased with the formation of the ODS layer. The ring-tensile strength of Zircaloy-4 increased from 790 to 870 MPa at room temperature, from 500 to 575 MPa at 380°C, and from 385 to 470 MPa at 500°C. Strengthening became more effective as the test temperature increased. It was noted that brittle fracture occurred at room temperature, which was not observed at elevated temperatures. Resistance to dynamic high-temperature bursting improved. The burst temperature increased from 760 to 830°C at a heating rate of 5°C/s and internal pressure of 8.3 MPa. The burst opening was also smaller than those in fresh Zircaloy-4 tubes. This method is expected to enhance the safety of Zr fuel cladding tubes owing to the improvement of their mechanical properties. Keywords: Laser Surface Treatment, Microstructure, Oxide Dispersion Strengthened Alloy, Tensile Strength, Zirconium Alloy

Neutron Diffraction from the Second Layer of 4He on Graphite

DEFF Research Database (Denmark)

da Costa Carneiro, Kim; Passell, L.; Thomlinson, W.

1981-01-01

Neutron diffraction has been used to study the second atomic layer of **4He adsorbed on graphite. As the **4He-coverage exceeds the first layer, the second initially forms a fluid phase. But when there is enough **4He in the third layer to compress the second, this layer solidifies. The structure...

Use of graphite layer open tubular (GLOT) in environmental analysis

International Nuclear Information System (INIS)

Bruner, F.; Lattanzi, L.; Borghesi, P.

1996-01-01

Recently it has been developed a series of new capillary columns characterised by the use of graphitized carbon black modified from different amount of liquid phase. The characteristics of these columns, called graphite layer open tubular (GLOT), are described together with their application to the environmental analysis. A specific application of GLOT columns is for the direct analysis of aqueous solutions avoiding solvent extraction procedure. A comparison between a GLOT column and a traditional capillary column, estimating their behaviour after repeated direct injections of aqueous solution sample is written. Some applications regarding the analysis of the atmosphere pollutants, as aliphatic and aromatic hydrocarbons, and their compounds are written too

OpenMP 4.5 Validation and Verification Suite

Energy Technology Data Exchange (ETDEWEB)

2017-12-15

OpenMP, a directive-based programming API, introduce directives for accelerator devices that programmers are starting to use more frequently in production codes. To make sure OpenMP directives work correctly across architectures, it is critical to have a mechanism that tests for an implementation's conformance to the OpenMP standard. This testing process can uncover ambiguities in the OpenMP specification, which helps compiler developers and users make a better use of the standard. We fill this gap through our validation and verification test suite that focuses on the offload directives available in OpenMP 4.5.

Dimensions of open research: critical reflections on openness in the ROER4D project

Directory of Open Access Journals (Sweden)

Thomas William King

2016-05-01

Full Text Available Open Research has the potential to advance the scientific process by improving the transparency, rigour, scope and reach of research, but choosing to experiment with Open Research carries with it a set of ideological, legal, technical and operational considerations. Researchers, especially those in resource-constrained situations, may not be aware of the complex interrelations between these different domains of open practice, the additional resources required, or how Open Research can support traditional research practices. Using the Research on Open Educational Resources for Development (ROER4D project as an example, this paper attempts to demonstrate the interrelation between ideological, legal, technical and operational openness; the resources that conducting Open Research requires; and the benefits of an iterative, strategic approach to one’s own Open Research practice. In this paper we discuss the value of a critical approach towards Open Research to ensure better coherence between ‘open’ ideology (embodied in strategic intention and ‘open’ practice (the everyday operationalisation of open principles.

Adjustment of Conduction Band Edge of Compact TiO2 Layer in Perovskite Solar Cells Through TiCl4 Treatment.

Science.gov (United States)

Murakami, Takurou N; Miyadera, Tetsuhiko; Funaki, Takashi; Cojocaru, Ludmila; Kazaoui, Said; Chikamatsu, Masayuki; Segawa, Hiroshi

2017-10-25

Perovskite solar cells (PSCs) without a mesoporous TiO 2 layer, that is, planar-type PSCs exhibit poorer cell performance as compared to PSCs with a porous TiO 2 layer, owing to inefficient electron transfer from the perovskite layer to the compact TiO 2 layer in the former case. The matching of the conduction band levels of perovskite and the compact TiO 2 layer is thus essential for enhancing PSC performance. In this study, we demonstrate the shifting of the conduction band edge (CBE) of the compact TiO 2 layer through a TiCl 4 treatment, with the aim of improving PSC performance. The CBE of the compact TiO 2 layer was shifted to a higher level through the TiCl 4 treatment and then shifted in the opposite direction, that is, to a lower level, through a subsequent heat treatment. These shifts in the CBE were reflected in the PSC performance. The TiCl 4 -treated PSC showed an increase in the open-circuit voltage of more than 150 mV, as well as a decrease of 100 mV after being heated at 450 °C. On the other hand, the short-circuit current decreased after the treatment but increased after heating at temperatures higher than 300 °C. The treated PSC subjected to subsequent heating at 300 °C exhibited the best performance, with the power conversion efficiency of the PSC being 17% under optimized conditions.

Interplay between dewetting and layer inversion in poly(4-vinylpyridine)/polystyrene bilayers.

Science.gov (United States)

Thickett, Stuart C; Harris, Andrew; Neto, Chiara

2010-10-19

We investigated the morphology and dynamics of the dewetting of metastable poly(4-vinylpyridine) (P4VP) thin films situated on top of polystyrene (PS) thin films as a function of the molecular weight and thickness of both films. We focused on the competition between the dewetting process, occurring as a result of unfavorable intermolecular interactions at the P4VP/PS interface, and layer inversion due to the lower surface energy of PS. By means of optical and atomic force microscopy (AFM), we observed how both the dynamics of the instability and the morphology of the emerging patterns depend on the ratio of the molecular weights of the polymer films. When the bottom PS layer was less viscous than the top P4VP layer (liquid-liquid dewetting), nucleated holes in the P4VP film typically stopped growing at long annealing times because of a combination of viscous dissipation in the bottom layer and partial layer inversion. Full layer inversion was achieved when the viscosity of the top P4VP layer was significantly greater (>10⁴) than the viscosity of the PS layer underneath, which is attributed to strongly different mobilities of the two layers. The density of holes produced by nucleation dewetting was observed for the first time to depend on the thickness of the top film as well as the polymer molecular weight. The final (completely dewetted) morphology of isolated droplets could be achieved only if the time frame of layer inversion was significantly slower than that of dewetting, which was characteristic of high-viscosity PS underlayers that allowed dewetting to fall into a liquid-solid regime. Assuming a simple reptation model for layer inversion occurring at the dewetting front, the observed surface morphologies could be predicted on the basis of the relative rates of dewetting and layer inversion.

Improve the open-circuit voltage of ZnO solar cells with inserting ZnS layers by two ways

International Nuclear Information System (INIS)

Sun, Yunfei; Yang, Jinghai; Yang, Lili; Cao, Jian; Gao, Ming; Zhang, Zhiqiang; Wang, Zhe; Song, Hang

2013-01-01

ZnS NPs layers were deposited on ZnO NRs by two different ways. One is spin coating; the other is successive ionic layer adsorption and reaction (SILAR) method. The ZnO NRs/ZnS NPs composites were verified by X-ray diffraction, X-ray photoelectron spectroscopy, and UV–visible spectrophotometer; their morphologies and thicknesses were examined by scanning electron microscopic and transmission electron microscopic images. The CdS quantum dot sensitized solar cells (QDSSCs) were constructed using ZnO NRs/ZnS NPs composites as photoanode and their photovoltaic characteristic was studied by J–V curves. The results indicated that the way of SILAR is more beneficial for retarding the back transfer of electrons to CdS and electrolyte than spin coating method. The open-circuit voltage increased to 0.59 V by introducing a ZnS layer through SILAR method. When ZnS NPs layer was deposited for 10 times on ZnO NRs, the conversion efficiency of QDSSC shows ∼3.3 folds increments of as-synthesized ZnO solar cell. - Graphical abstract: When ZnO nanorods were deposited by ZnS for 10 times, the conversion efficiency of QDSSC shows ∼3.3 folds increments of as-synthesized ZnO solar cell. Highlights: ► ZnS layers were deposited with two different ways. ► The way of SILAR is more beneficial for retarding the back transfer of electrons. ► The open-circuit voltage increased to 0.59 V by introducing a ZnS layer through SILAR method

Improve the open-circuit voltage of ZnO solar cells with inserting ZnS layers by two ways

Energy Technology Data Exchange (ETDEWEB)

Sun, Yunfei [State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100049 (China); Yang, Jinghai, E-mail: jhyang1@jlnu.edu.cn [Institute of Condensed State Physics, Jilin Normal University, Siping 136000 (China); Yang, Lili; Cao, Jian [Institute of Condensed State Physics, Jilin Normal University, Siping 136000 (China); Gao, Ming [State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100049 (China); Institute of Condensed State Physics, Jilin Normal University, Siping 136000 (China); Zhang, Zhiqiang; Wang, Zhe [Institute of Condensed State Physics, Jilin Normal University, Siping 136000 (China); Song, Hang [State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China)

2013-04-15

ZnS NPs layers were deposited on ZnO NRs by two different ways. One is spin coating; the other is successive ionic layer adsorption and reaction (SILAR) method. The ZnO NRs/ZnS NPs composites were verified by X-ray diffraction, X-ray photoelectron spectroscopy, and UV–visible spectrophotometer; their morphologies and thicknesses were examined by scanning electron microscopic and transmission electron microscopic images. The CdS quantum dot sensitized solar cells (QDSSCs) were constructed using ZnO NRs/ZnS NPs composites as photoanode and their photovoltaic characteristic was studied by J–V curves. The results indicated that the way of SILAR is more beneficial for retarding the back transfer of electrons to CdS and electrolyte than spin coating method. The open-circuit voltage increased to 0.59 V by introducing a ZnS layer through SILAR method. When ZnS NPs layer was deposited for 10 times on ZnO NRs, the conversion efficiency of QDSSC shows ∼3.3 folds increments of as-synthesized ZnO solar cell. - Graphical abstract: When ZnO nanorods were deposited by ZnS for 10 times, the conversion efficiency of QDSSC shows ∼3.3 folds increments of as-synthesized ZnO solar cell. Highlights: ► ZnS layers were deposited with two different ways. ► The way of SILAR is more beneficial for retarding the back transfer of electrons. ► The open-circuit voltage increased to 0.59 V by introducing a ZnS layer through SILAR method.

Photoluminescence and photostability of YVO{sub 4}:Eu{sup 3+} nanoparticle/layered double hydroxide multilayer films prepared via layer-by-layer assembly

Energy Technology Data Exchange (ETDEWEB)

Onishi, Wataru; Takeshita, Satoru, E-mail: takeshita@applc.keio.ac.jp; Iso, Yoshiki; Isobe, Tetsuhiko, E-mail: isobe@applc.keio.ac.jp

2016-07-15

Layered double hydroxides (LDHs) consist of positively charged brucite-like layers with interlayer anions for charge compensation. Delaminated cationic LDH nanosheets can be used as building blocks to fabricate functional nanocomposites. In this study, we fabricated photoluminescent multilayer films containing positively charged LDH nanosheets and negatively charged YVO{sub 4}:Eu{sup 3+} nanoparticles on quartz glass substrates through a layer-by-layer assembly technique. The absorbance and photoluminescence (PL) intensity of the YVO{sub 4}:Eu{sup 3+} nanoparticles in the multilayer films were proportional to the number of deposition cycles. These linear relationships indicate that constant amounts of LDH nanosheets and YVO{sub 4}:Eu{sup 3+} nanoparticles were alternately deposited on the substrate. The change in intensity of the 620 nm emission of the YVO{sub 4}:Eu{sup 3+} nanoparticle powder and the multilayer film (LDH/YVO{sub 4}:Eu{sup 3+}){sub 10} under continuous 270 nm excitation was measured to compare both photostabilities. The PL intensity of the YVO{sub 4}:Eu{sup 3+} nanoparticle powder decreased to 7% of the initial intensity and then gradually recovered to 19%. In contrast, the PL intensity of the multilayer film (LDH/YVO{sub 4}:Eu{sup 3+}){sub 10} decreased to 36% of the initial intensity and then recovered to 139%. The photo-degradation and recovery are discussed.

Synthesis, structure and photoluminescence properties of amine-templated open-framework bismuth sulfates

International Nuclear Information System (INIS)

Marri, Subba R.; Behera, J.N.

2014-01-01

Two organically-templated bismuth sulfates of the compositions, [C 6 N 2 H 14 ] [Bi(SO 4 ) 2 (NO 3 )], (1) and [C 4 N 2 H 12 ] 4 [Bi 4 (SO 4 ) 10 (H 2 O) 4 ], (2), with open architecture have been synthesized and their structures determined by single crystal X-ray diffraction. 1 has a corrugated layered structure with 8-membered aperture wherein the SO 4 tetrahedra and the BiO 8 polyhedra join together to form (4, 4) net sheets of the metal centers while 2 has a three-dimensional structure possessing 8- and 12-membered channels. Both the compounds show good fluorescence properties exhibiting blue luminescence. Time-resolved fluorescence behavior of 1 and 2 shows mean fluorescence life time of 0.9 and 1.0 ns, respectively. - Graphical abstract: Two open-framework bismuth sulfates with the layered and three-dimensional structures have been synthesized and characterized. Both the compounds show good fluorescence properties exhibiting blue luminescence. Display Omitted - Highlights: • Two organically-templated bismuth sulfates with open architecture have been synthesized and characterized. • One has a corrugated layered structure while the other one has a three-dimensional structure possessing channels. • They are novel in that open-framework three-dimensional main group metal sulfates are first to be reported. • They show good fluorescence properties exhibiting blue luminescence

Formation of Lamellar Structured Oxide Dispersion Strengthening Layers in Zircaloy-4

Energy Technology Data Exchange (ETDEWEB)

Jung, Yang-Il; Park, Jung-Hwan; Park, Dong-Jun; Kim, Hyun-Gil; Yang, Jae-Ho; Koo, Yang-Hyun [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Lim, Yoon-Soo [Hanbat National University, Daejeon (Korea, Republic of)

2016-10-15

Korea Atomic Energy Research Institute (KAERI) is one of the leading organizations for developing ATF claddings. One concept is to form an oxidation-resistant layer on Zr cladding surface. The other is to increase high-temperature mechanical strength of Zr tube. The oxide dispersion strengthened (ODS) zirconium was proposed to increase the strength of the Zr-based alloy up to high temperatures. According to our previous investigations, the tensile strength of Zircaloy-4 was increased by up to 20% with the formation of a thin dispersed oxide layer with a thickness less than 10% of that of the Zircaloy-4 substrate. However, the tensile elongation of the samples decreased drastically. The brittle fracture was a major concern in development of the ODS Zircaloy-4. In this study, a lamellar structure of ODS layer was formed to increase ductility of the ODS Zircaloy-4. The mechanical properties were varied depending on the structure of ODS layer. For example, the partial formation of ODS layer with the thickness of 10% to the substrate thickness induced the increase in tensile strength up to about 20% than fresh Zircaloy-4.

Numerical simulation of viscoelastic layer rearrangement in polymer melts using OpenFOAM®

Energy Technology Data Exchange (ETDEWEB)

Köpplmayr, Thomas, E-mail: tkoepplmayr@gmail.com; Mayrhofer, Elias [Institute of Polymer Extrusion and Compounding, Johannes Kepler University Linz, Altenberger Str. 69, 4040 Linz (Austria)

2015-05-22

In addition to their shear-thinning behavior, polymer melts are characterized by first and second normal stress differences, which cause secondary motions. Polymer coextrusion processes involve viscoelastic two-phase flows that influence layer formation. Using polymer melts with different pigmentation makes visible the layers deformed by second normal stress differences. We used a new solver for the OpenFOAM CFD toolbox which handles viscoelastic two-phase flows. A derivative of the volume-of-fluid (VoF) methodology was employed to describe the interface. Different types of polymer melt, such as polyethylene (PE), polypropylene (PP) and polyethylene terephthalate (PET) were investigated. In a coextrusion process, the less viscous phase usually tends to encapsulate the more viscous one. However, the different viscoelastic properties of the melts also influence interface deformation. The materials were characterized by small-amplitude oscillatory-shear rheometry, and a multimode Giesekus model was used to fit shear viscosity, storage and loss modulus. Our simulations also took interfacial tension into account. Experimental observations and corresponding numerical simulations were found to be in good accordance.

Numerical simulation of viscoelastic layer rearrangement in polymer melts using OpenFOAM®

International Nuclear Information System (INIS)

Köpplmayr, Thomas; Mayrhofer, Elias

2015-01-01

In addition to their shear-thinning behavior, polymer melts are characterized by first and second normal stress differences, which cause secondary motions. Polymer coextrusion processes involve viscoelastic two-phase flows that influence layer formation. Using polymer melts with different pigmentation makes visible the layers deformed by second normal stress differences. We used a new solver for the OpenFOAM CFD toolbox which handles viscoelastic two-phase flows. A derivative of the volume-of-fluid (VoF) methodology was employed to describe the interface. Different types of polymer melt, such as polyethylene (PE), polypropylene (PP) and polyethylene terephthalate (PET) were investigated. In a coextrusion process, the less viscous phase usually tends to encapsulate the more viscous one. However, the different viscoelastic properties of the melts also influence interface deformation. The materials were characterized by small-amplitude oscillatory-shear rheometry, and a multimode Giesekus model was used to fit shear viscosity, storage and loss modulus. Our simulations also took interfacial tension into account. Experimental observations and corresponding numerical simulations were found to be in good accordance

Synthesis and characterization of [4-(2,4-dichlorophenoxybutyrate)-zinc layered hydroxide] nanohybrid

Science.gov (United States)

Hussein, Mohd Zobir; Hashim, Norhayati; Yahaya, Asmah Hj.; Zainal, Zulkarnain

2010-05-01

A new layered organic-inorganic nanohybrid material in which an agrochemical, 4-(2,4-dichlorophenoxy)butyrate (DPBA) is intercalated into inorganic interlayers of zinc layered hydroxide (ZLH) was synthesized by direct reaction of aqueous DPBA solution with zinc oxide. The resulting nanohybrid is composed of the organic moieties, DPBA sandwiched between ZLH inorganic interlayers. The nanohybrid afforded well ordered crystalline layered structure, a basal spacing of 29.6 Å, 23.5% carbon (w/w) and 47.9% (w/w) loading of DPBA. FTIR study shows that the absorption bands of the resulting nanohybrid composed the FTIR characteristics of both the DPBA and ZLH which further confirmed the intercalation episode. The intercalated organic moiety in the form of nanohybrid is thermally more stable than its sodium salt. Scanning electron micrograph shows the ZnO precursor has very fine granular structure and transformed into a flake-like when the nanohybrid is formed. This work shows that the nanohybrid of DPBA-ZLH can be synthesized using simple, direct reaction of ZnO and DPBA under aqueous environment for the formation of a new generation of agrochemical.

Synthesis, structure and photoluminescence properties of amine-templated open-framework bismuth sulfates

Energy Technology Data Exchange (ETDEWEB)

Marri, Subba R.; Behera, J.N., E-mail: jnbehera@niser.ac.in

2014-02-15

Two organically-templated bismuth sulfates of the compositions, [C{sub 6}N{sub 2}H{sub 14}] [Bi(SO{sub 4}){sub 2}(NO{sub 3})], (1) and [C{sub 4}N{sub 2}H{sub 12}]{sub 4}[Bi{sub 4}(SO{sub 4}){sub 10}(H{sub 2}O){sub 4}], (2), with open architecture have been synthesized and their structures determined by single crystal X-ray diffraction. 1 has a corrugated layered structure with 8-membered aperture wherein the SO{sub 4} tetrahedra and the BiO{sub 8} polyhedra join together to form (4, 4) net sheets of the metal centers while 2 has a three-dimensional structure possessing 8- and 12-membered channels. Both the compounds show good fluorescence properties exhibiting blue luminescence. Time-resolved fluorescence behavior of 1 and 2 shows mean fluorescence life time of 0.9 and 1.0 ns, respectively. - Graphical abstract: Two open-framework bismuth sulfates with the layered and three-dimensional structures have been synthesized and characterized. Both the compounds show good fluorescence properties exhibiting blue luminescence. Display Omitted - Highlights: • Two organically-templated bismuth sulfates with open architecture have been synthesized and characterized. • One has a corrugated layered structure while the other one has a three-dimensional structure possessing channels. • They are novel in that open-framework three-dimensional main group metal sulfates are first to be reported. • They show good fluorescence properties exhibiting blue luminescence.

The Effect of Single Pyramidal Neuron Firing Within Layer 2/3 and Layer 4 in Mouse V1.

Science.gov (United States)

Meyer, Jochen F; Golshani, Peyman; Smirnakis, Stelios M

2018-01-01

The influence of cortical cell spiking activity on nearby cells has been studied extensively in vitro . Less is known, however, about the impact of single cell firing on local cortical networks in vivo . In a pioneering study, Kwan and Dan (Kwan and Dan, 2012) reported that in mouse layer 2/3 (L2/3), under anesthesia , stimulating a single pyramidal cell recruits ~2.1% of neighboring units. Here we employ two-photon calcium imaging in layer 2/3 of mouse V1, in conjunction with single-cell patch clamp stimulation in layer 2/3 or layer 4, to probe, in both the awake and lightly anesthetized states , how (i) activating single L2/3 pyramidal neurons recruits neighboring units within L2/3 and from layer 4 (L4) to L2/3, and whether (ii) activating single pyramidal neurons changes population activity in local circuit. To do this, it was essential to develop an algorithm capable of quantifying how sensitive the calcium signal is at detecting effectively recruited units ("followers"). This algorithm allowed us to estimate the chance of detecting a follower as a function of the probability that an epoch of stimulation elicits one extra action potential (AP) in the follower cell. Using this approach, we found only a small fraction (layer-2/3 or layer-4 pyramidal neurons produces few (<1% of local units) reliable single-cell followers in L2/3 of mouse area V1, either under light anesthesia or in quiet wakefulness: instead, single cell stimulation was found to elevate aggregate population activity in a weak but highly distributed fashion.

Availability improvement of layer 2 seamless networks using OpenFlow.

Science.gov (United States)

Molina, Elias; Jacob, Eduardo; Matias, Jon; Moreira, Naiara; Astarloa, Armando

2015-01-01

The network robustness and reliability are strongly influenced by the implementation of redundancy and its ability of reacting to changes. In situations where packet loss or maximum latency requirements are critical, replication of resources and information may become the optimal technique. To this end, the IEC 62439-3 Parallel Redundancy Protocol (PRP) provides seamless recovery in layer 2 networks by delegating the redundancy management to the end-nodes. In this paper, we present a combination of the Software-Defined Networking (SDN) approach and PRP topologies to establish a higher level of redundancy and thereby, through several active paths provisioned via the OpenFlow protocol, the global reliability is increased, as well as data flows are managed efficiently. Hence, the experiments with multiple failure scenarios, which have been run over the Mininet network emulator, show the improvement in the availability and responsiveness over other traditional technologies based on a single active path.

Diverse assemblies of the (4,4) grid layers exemplified in Zn(II)/Co(II) coordination polymers with dual linear ligands

International Nuclear Information System (INIS)

Liu, Guang-Zhen; Li, Xiao-Dong; Xin, Ling-Yun; Li, Xiao-Ling; Wang, Li-Ya

2013-01-01

Diverse (4,4) grid layers are exemplified in five two-dimensional coordination polymers with dual µ 2 -bridged ligands, namely, ([Zn(cbaa)(bpp)]·H 2 O) n (1), [Zn 2 (cbaa) 2 (bpy)] n (2), [Co 2 (cbaa) 2 (bpp) 2 ] n (3), [Co(cbaa)(bpp)] n (4), and [Co(bdaa)(bpp)(H 2 O) 2 ] n (5) (H 2 cbaa=4-carboxybenzeneacetic acid, bpp=1,3-di(4-pyridyl)propane, bpy=4,4′-bipyridyl, and H 2 bdaa=1,4-benzenediacrylic acid). For 1, two (4,4) grid layers with [ZnN 2 O 2 ] tetrahedron as the node are held together by lattice water forming a H-bonding bilayer. Individual (4,4) grid layer in 2 is based on (Zn 2 (OCO) 4 ) paddlewheel unit as the node. Two (4,4) grid layers with (Co 2 O(OCO) 2 ) dimer as the node are covalently interconnected by organic ligands affording a thick bilayer of 3 with new framework topology. The different entanglements between two coincident (4,4) grid layers with [CoN 2 O 4 ] octahedron as the node leads to two 2D→2D interpenetrated structures for 4 and 5. Furthermore, fluorescent properties of 1 and 2 as well as magnetic properties of 3 are investigated. - Graphical abstract: Diverse assemblies of the (4,4) grid layers with different network nodes forms five coordination polymers that are well characterized by IR, TGA, element analysis, fluorescent and magnetic measurement. - Highlights: • Diverse assemblies of the (4,4) grid layers with different structural units as the nodes. • A new topology type with the uninodal 6-connected net of (4 12 .5 2 .6) is found. • Intense fluorescence emissions with a rare blue-shift of 55 nm compared to free carboxylate ligand

Subnanometer Ga2O3 tunnelling layer by atomic layer deposition to achieve 1.1 V open-circuit potential in dye-sensitized solar cells.

Science.gov (United States)

Chandiran, Aravind Kumar; Tetreault, Nicolas; Humphry-Baker, Robin; Kessler, Florian; Baranoff, Etienne; Yi, Chenyi; Nazeeruddin, Mohammad Khaja; Grätzel, Michael

2012-08-08

Herein, we present the first use of a gallium oxide tunnelling layer to significantly reduce electron recombination in dye-sensitized solar cells (DSC). The subnanometer coating is achieved using atomic layer deposition (ALD) and leading to a new DSC record open-circuit potential of 1.1 V with state-of-the-art organic D-π-A sensitizer and cobalt redox mediator. After ALD of only a few angstroms of Ga(2)O(3), the electron back reaction is reduced by more than an order of magnitude, while charge collection efficiency and fill factor are increased by 30% and 15%, respectively. The photogenerated exciton separation processes of electron injection into the TiO(2) conduction band and the hole injection into the electrolyte are characterized in detail.

Efficient white organic light-emitting devices using a thin 4,4'-bis(2,2'-diphenylvinyl)-1,1'-diphenyl layer

International Nuclear Information System (INIS)

Wang Jun; Yu Junsheng; Li Lu; Tang Xiaoqing; Jiang Yadong

2008-01-01

White organic light-emitting devices (OLEDs) were fabricated using phosphorescent material bis[2-(4-tert-butylphenyl)benzothiazolato-N,C 2' ]iridium (acetylacetonate) [(t-bt) 2 Ir(acac)] doped in 4,4'-bis(carbazol-9-yl) biphenyl (CBP) matrix as a yellow light-emitting layer and a thin layer 4,4'-bis(2,2'-diphenylvinyl)-1,1'-diphenyl (DPVBi) as the blue light-emitting layer. The light colour of the OLEDs can be adjusted by changing doped concentration and the thickness of the DPVBi thin layer. The maximum luminance and power efficiency of 5% doped device reached 15 460 cd m -2 and 8.1 lm W -1 , respectively. The 3% doped device showed the CIE coordinates of (0.344, 0.322) at 8 V and a maximum power efficiency of 5.7 lm W -1 at 4.5 V

OpenLayers izmantošana Android ĢIS lietotnē

OpenAIRE

Krūmiņš, Kristaps

2015-01-01

“OpenLayers izmantošana Android ĢIS lietotnē” ir kvalifikācijas darbs, kurā tika izstrādāta hibrīd Android lietotne. Lietotne domāta cilvēkiem, kas vēlas iemūžināt bildes un vēlāk tās apskatīt kartē, lai redzētu kurā vietā bildes tika uzņemtas, kā arī redzēt pārējās bildes, kas tika uzņemtas šajā vietā vai tās tuvumā. Papildus tam, lietotni var izmantot, lai orientētos apkārtnē un, lai apskatītu savu veikto ceļu. Projekts realizēts pēc spējās izstrādes metodoloģijas. Izstrādes procesā tika iz...

2D water layer enclathrated between Mn(II)-Ni(CN)4 coordination frameworks

International Nuclear Information System (INIS)

Ray, Ambarish; Bhowmick, Indrani; Sheldrick, William S.; Jana, Atish Dipankar; Ali, Mahammed

2009-01-01

A [Ni(CN) 4 ] 2- based two-dimensional Mn(II) coordination polymer {Mn(H 2 O) 2 [NiCN] 4 .4H 2 O}, in which the coordination layers are stacked on top of each other sandwiching 2D water layer of boat-shaped hexagonal water clusters has been synthesized. The complex exhibits high thermal decomposition temperature and reversible water absorption, which were clearly demonstrated by thermal and PXRD studies on the parent and rehydrated complex after dehydration. - Abstract: A coordination polymer, {Mn(H 2 O) 2 [NiCN] 4 .4H 2 O} n , showed that the coordination layers are stacked on top of each other sandwiching 2D ice layer of boat-shaped hexagonal water clusters . Display Omitted

Diverse assemblies of the (4,4) grid layers exemplified in Zn(II)/Co(II) coordination polymers with dual linear ligands

Energy Technology Data Exchange (ETDEWEB)

Liu, Guang-Zhen; Li, Xiao-Dong; Xin, Ling-Yun; Li, Xiao-Ling [College of Chemistry and Chemical Engineering, Luoyang Normal University, Luoyang, Henan 471022 (China); Wang, Li-Ya, E-mail: wlya@lynu.edu.cn [College of Chemistry and Chemical Engineering, Luoyang Normal University, Luoyang, Henan 471022 (China); College of Chemistry and Pharmacy Engineering, Nanyang Normal University, Nanyang, Henan 473061 (China)

2013-07-15

Diverse (4,4) grid layers are exemplified in five two-dimensional coordination polymers with dual µ{sub 2}-bridged ligands, namely, ([Zn(cbaa)(bpp)]·H{sub 2}O){sub n} (1), [Zn{sub 2}(cbaa){sub 2}(bpy)]{sub n} (2), [Co{sub 2}(cbaa){sub 2}(bpp){sub 2}]{sub n} (3), [Co(cbaa)(bpp)]{sub n} (4), and [Co(bdaa)(bpp)(H{sub 2}O){sub 2}]{sub n} (5) (H{sub 2}cbaa=4-carboxybenzeneacetic acid, bpp=1,3-di(4-pyridyl)propane, bpy=4,4′-bipyridyl, and H{sub 2}bdaa=1,4-benzenediacrylic acid). For 1, two (4,4) grid layers with [ZnN{sub 2}O{sub 2}] tetrahedron as the node are held together by lattice water forming a H-bonding bilayer. Individual (4,4) grid layer in 2 is based on (Zn{sub 2}(OCO){sub 4}) paddlewheel unit as the node. Two (4,4) grid layers with (Co{sub 2}O(OCO){sub 2}) dimer as the node are covalently interconnected by organic ligands affording a thick bilayer of 3 with new framework topology. The different entanglements between two coincident (4,4) grid layers with [CoN{sub 2}O{sub 4}] octahedron as the node leads to two 2D→2D interpenetrated structures for 4 and 5. Furthermore, fluorescent properties of 1 and 2 as well as magnetic properties of 3 are investigated. - Graphical abstract: Diverse assemblies of the (4,4) grid layers with different network nodes forms five coordination polymers that are well characterized by IR, TGA, element analysis, fluorescent and magnetic measurement. - Highlights: • Diverse assemblies of the (4,4) grid layers with different structural units as the nodes. • A new topology type with the uninodal 6-connected net of (4{sup 12}.5{sup 2}.6) is found. • Intense fluorescence emissions with a rare blue-shift of 55 nm compared to free carboxylate ligand.

Wall modified photonic crystal fibre capillaries as porous layer open tubular columns for in-capillary micro-extraction and capillary chromatography

International Nuclear Information System (INIS)

Kazarian, Artaches A.; Sanz Rodriguez, Estrella; Deverell, Jeremy A.; McCord, James; Muddiman, David C.; Paull, Brett

2016-01-01

Wall modified photonic crystal fibre capillary columns for in-capillary micro-extraction and liquid chromatographic separations is presented. Columns contained 126 internal parallel 4 μm channels, each containing a wall bonded porous monolithic type polystyrene-divinylbenzene layer in open tubular column format (PLOT). Modification longitudinal homogeneity was monitored using scanning contactless conductivity detection and scanning electron microscopy. The multichannel open tubular capillary column showed channel diameter and polymer layer consistency of 4.2 ± 0.1 μm and 0.26 ± 0.02 μm respectively, and modification of 100% of the parallel channels with the monolithic polymer. The modified multi-channel capillaries were applied to the in-capillary micro-extraction of water samples. 500 μL of water samples containing single μg L"−"1 levels of polyaromatic hydrocarbons were extracted at a flow rate of 10 μL min"−"1, and eluted in 50 μL of acetonitrile for analysis using HPLC with fluorescence detection. HPLC LODs were 0.08, 0.02 and 0.05 μg L"−"1 for acenaphthene, anthracene and pyrene, respectively, with extraction recoveries of between 77 and 103%. The modified capillaries were also investigated briefly for direct application to liquid chromatographic separations, with the retention and elution of a standard protein (cytochrome c) under isocratic conditions demonstrated, proving chromatographic potential of the new column format, with run-to-run retention time reproducibility of below 1%. - Highlights: • Novel PS-DVB modified photonic crystal fibres for in-capillary micro-extraction. • New method for micro-extraction of PAHs and HPLC-FL detection at sub-ppb levels. • Demonstration of PS-DVB modified photonic crystal fibres for capillary bioseparations.

Wall modified photonic crystal fibre capillaries as porous layer open tubular columns for in-capillary micro-extraction and capillary chromatography

Energy Technology Data Exchange (ETDEWEB)

Kazarian, Artaches A. [Australian Centre for Research on Separation Science, School of Physical Sciences, University of Tasmania, Private Bag 75, Hobart, Tasmania 7001 (Australia); W.M. Keck FT-ICR-MS Laboratory, Department of Chemistry, North Carolina State University, Raleigh, NC (United States); Sanz Rodriguez, Estrella; Deverell, Jeremy A. [Australian Centre for Research on Separation Science, School of Physical Sciences, University of Tasmania, Private Bag 75, Hobart, Tasmania 7001 (Australia); McCord, James; Muddiman, David C. [W.M. Keck FT-ICR-MS Laboratory, Department of Chemistry, North Carolina State University, Raleigh, NC (United States); Paull, Brett, E-mail: Brett.Paull@utas.edu.au [Australian Centre for Research on Separation Science, School of Physical Sciences, University of Tasmania, Private Bag 75, Hobart, Tasmania 7001 (Australia); ARC Centre of Excellence for Electromaterials Science, School of Physical Sciences, University of Tasmania, Private Bag 75, Hobart, Tasmania 7001 (Australia)

2016-01-28

Wall modified photonic crystal fibre capillary columns for in-capillary micro-extraction and liquid chromatographic separations is presented. Columns contained 126 internal parallel 4 μm channels, each containing a wall bonded porous monolithic type polystyrene-divinylbenzene layer in open tubular column format (PLOT). Modification longitudinal homogeneity was monitored using scanning contactless conductivity detection and scanning electron microscopy. The multichannel open tubular capillary column showed channel diameter and polymer layer consistency of 4.2 ± 0.1 μm and 0.26 ± 0.02 μm respectively, and modification of 100% of the parallel channels with the monolithic polymer. The modified multi-channel capillaries were applied to the in-capillary micro-extraction of water samples. 500 μL of water samples containing single μg L{sup −1} levels of polyaromatic hydrocarbons were extracted at a flow rate of 10 μL min{sup −1}, and eluted in 50 μL of acetonitrile for analysis using HPLC with fluorescence detection. HPLC LODs were 0.08, 0.02 and 0.05 μg L{sup −1} for acenaphthene, anthracene and pyrene, respectively, with extraction recoveries of between 77 and 103%. The modified capillaries were also investigated briefly for direct application to liquid chromatographic separations, with the retention and elution of a standard protein (cytochrome c) under isocratic conditions demonstrated, proving chromatographic potential of the new column format, with run-to-run retention time reproducibility of below 1%. - Highlights: • Novel PS-DVB modified photonic crystal fibres for in-capillary micro-extraction. • New method for micro-extraction of PAHs and HPLC-FL detection at sub-ppb levels. • Demonstration of PS-DVB modified photonic crystal fibres for capillary bioseparations.

29 CFR 1612.4 - Exemptions to open meeting policy.

Science.gov (United States)

2010-07-01

... 29 Labor 4 2010-07-01 2010-07-01 false Exemptions to open meeting policy. 1612.4 Section 1612.4 Labor Regulations Relating to Labor (Continued) EQUAL EMPLOYMENT OPPORTUNITY COMMISSION GOVERNMENT IN...) disclose investigative techniques and procedures, or (6) endanger the life of physical safety of law...

Single-layer and double-layer microwave absorbers based on Co{sub 67}Ni{sub 33} microspheres and Ni{sub 0.6}Zn{sub 0.4}Fe{sub 2}O{sub 4} nanocrystals

Energy Technology Data Exchange (ETDEWEB)

Wang, Min [Engineering Technology Research Center of Magnetic Materials of Anhui Province, School of Physics & Materials Science, Anhui University, Hefei 230601 (China); Wang, Zhongzhu, E-mail: wangzz@ahu.edu.cn [Engineering Technology Research Center of Magnetic Materials of Anhui Province, School of Physics & Materials Science, Anhui University, Hefei 230601 (China); Wang, Peihong; Liao, Yanlin [Engineering Technology Research Center of Magnetic Materials of Anhui Province, School of Physics & Materials Science, Anhui University, Hefei 230601 (China); Bi, Hong [School of Chemistry and Chemical Engineering, Anhui University, Hefei 230601 (China)

2017-03-01

Co{sub 67}Ni{sub 33} microspheres and Ni{sub 0.6}Zn{sub 0.4}Fe{sub 2}O{sub 4} nanocrystals were synthesized by hydrothermal method. The complex permeability and complex permittivity of the as-prepared powders dispersing in wax (60 wt% powder) were measured using a vector network analyzer in 2–18 GHz frequency range. The calculated microwave absorption of single-layer and double-layer absorbers based on Co{sub 67}Ni{sub 33} microspheres and Ni{sub 0.6}Zn{sub 0.4}Fe{sub 2}O{sub 4} nanocrystals were analyzed in 2–18 GHz frequency range. The results show that the Ni{sub 0.6}Zn{sub 0.4}Fe{sub 2}O{sub 4}nanocrystals with the relatively low permittivity and Co{sub 67}Ni{sub 33} microspheres with the relatively high dielectric loss and magnetic loss can be used as proper matching layer and excellent absorption layer, respectively. The double-layer absorber with a coating thickness of 2.1 mm exhibits a maximum reflection loss of −43.8 dB as well as a bandwidth (reflection loss less than −10 dB) of 5 GHz. Moreover, their absorption peak and the absorption intensity can be adjusted easily through changing the stacking order and each layer thickness. - Highlights: • Ni-Zn ferrite nanocrystals can use as matching layer in double-layer absorbers. • Co{sub 67}Ni{sub 33} microspheres with high dielectric loss can use as absorption layer. • Double-layer absorbers exhibits an excellent microwave absorption in 2–18 GHz.

Subnanometer Ga 2 O 3 Tunnelling Layer by Atomic Layer Deposition to Achieve 1.1 V Open-Circuit Potential in Dye-Sensitized Solar Cells

KAUST Repository

Chandiran, Aravind Kumar

2012-08-08

Herein, we present the first use of a gallium oxide tunnelling layer to significantly reduce electron recombination in dye-sensitized solar cells (DSC). The subnanometer coating is achieved using atomic layer deposition (ALD) and leading to a new DSC record open-circuit potential of 1.1 V with state-of-the-art organic D-π-A sensitizer and cobalt redox mediator. After ALD of only a few angstroms of Ga 2O 3, the electron back reaction is reduced by more than an order of magnitude, while charge collection efficiency and fill factor are increased by 30% and 15%, respectively. The photogenerated exciton separation processes of electron injection into the TiO 2 conduction band and the hole injection into the electrolyte are characterized in detail. © 2012 American Chemical Society.

A system of innovation to activate practices on open data: The Open4Citizens project

DEFF Research Database (Denmark)

Morelli, Nicola; Götzen, Amalia De; Simeone, Luca

2018-01-01

The increasing production of data is encouraging government institutions to consider the potential of open data as a public resource and to publish a large number of public datasets. This is configuring a new scenario in which open data are likely to play an important role for democracy...... and transparen-cy and for new innovation possibilities, in relation to the creation of a new generation of public services based on open data. In this context, though, it is possible to observe an asymmetry between the supply side of open data and the demand side. While more and more insti-tutions are producing...... and publishing data, there is no public awareness of the way in which such data can be used, nor is there a diffuse practice to work with those data. The definition of a practice for a large use of data is the aim of the Open4Citizens project, which promoted initiatives at different levels: at the level...

Improvement of photoluminescence from Ge layer with patterned Si3N4 stressors

International Nuclear Information System (INIS)

Oda, Katsuya; Okumura, Tadashi; Tani, Kazuki; Saito, Shin-ichi; Ido, Tatemi

2014-01-01

Lattice strain applied by patterned Si 3 N 4 stressors in order to improve the optical properties of Ge layers directly grown on a Si substrate was investigated. Patterned Si 3 N 4 stressors were fabricated by various methods and their effects on the strain and photoluminescence were studied. Although we found that when the stressor was fabricated by thermal chemical vapor deposition (CVD), the Ge waveguide was tensilely and compressively strained in the edge and center positions, respectively, and photoluminescence (PL) could be improved by decreasing the width of the waveguide, the crystallinity of the Ge waveguide was degraded by the thermal impact of the deposition process. Low-temperature methods were therefore used to make the patterned stressors. The tensile strain of the Ge layer increased from 0.14% to 0.2% when the stressor was grown by plasma enhanced CVD at 350 °C, but the effects of the increased tensile strain could not be confirmed because the Si 3 N 4 layer was unstable when irradiated with the excitation light used in photoluminescence measurements. Si 3 N 4 stressors grown by inductively coupled plasma CVD at room temperature increased the tensile strain of the Ge layer up to 0.4%, thus red-shifting the PL peak and obviously increasing the PL intensity. These results indicate that the Si 3 N 4 stressors fabricated by the room-temperature process efficiently improve the performance of Ge light-emitting devices. - Highlights: • Ge layers were directly grown on a Si substrate by low-temperature epitaxial growth. • Si 3 N 4 stressors were fabricated on the Ge layers by various methods. • Tensile strain of the Ge layers was improved by the Si 3 N 4 stressors. • Photoluminescence (PL) intensity was increased with the Si 3 N 4 stressors. • Red-shift of the PL spectra was observed from the tensile strained Ge layers

Data-driven simulation methodology using DES 4-layer architecture

Directory of Open Access Journals (Sweden)

Aida Saez

2016-05-01

Full Text Available In this study, we present a methodology to build data-driven simulation models of manufacturing plants. We go further than other research proposals and we suggest focusing simulation model development under a 4-layer architecture (network, logic, database and visual reality. The Network layer includes system infrastructure. The Logic layer covers operations planning and control system, and material handling equipment system. The Database holds all the information needed to perform the simulation, the results used to analyze and the values that the Logic layer is using to manage the Plant. Finally, the Visual Reality displays an augmented reality system including not only the machinery and the movement but also blackboards and other Andon elements. This architecture provides numerous advantages as helps to build a simulation model that consistently considers the internal logistics, in a very flexible way.

Ultrathin Co3O4 Layers Realizing Optimized CO2 Electroreduction to Formate.

Science.gov (United States)

Gao, Shan; Jiao, Xingchen; Sun, Zhongti; Zhang, Wenhua; Sun, Yongfu; Wang, Chengming; Hu, Qitao; Zu, Xiaolong; Yang, Fan; Yang, Shuyang; Liang, Liang; Wu, Ju; Xie, Yi

2016-01-11

Electroreduction of CO2 into hydrocarbons could contribute to alleviating energy crisis and global warming. However, conventional electrocatalysts usually suffer from low energetic efficiency and poor durability. Herein, atomic layers for transition-metal oxides are proposed to address these problems through offering an ultralarge fraction of active sites, high electronic conductivity, and superior structural stability. As a prototype, 1.72 and 3.51 nm thick Co3O4 layers were synthesized through a fast-heating strategy. The atomic thickness endowed Co3O4 with abundant active sites, ensuring a large CO2 adsorption amount. The increased and more dispersed charge density near Fermi level allowed for enhanced electronic conductivity. The 1.72 nm thick Co3O4 layers showed over 1.5 and 20 times higher electrocatalytic activity than 3.51 nm thick Co3O4 layers and bulk counterpart, respectively. Also, 1.72 nm thick Co3O4 layers showed formate Faradaic efficiency of over 60% in 20 h. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Electrodeposition of Fe_3O_4 layer from solution of Fe_2(SO_4)_3 with addition ethylene glycol

International Nuclear Information System (INIS)

Dahlan, Dahyunir; Asrar, Allan

2016-01-01

The electrodeposition of Fe_3O_4 layer from the solution Fe_2(SO_4)_3 with the addition of ethylene glycol on Indium Tin Oxide (ITO) substrate has been performed. The electrodeposition was carried out using a voltage of 5 volts for 120 seconds, with and without the addition of 2% wt ethylene glycol. Significant effects of temperature on the resulting the samples is observed when they are heated at 400 °C. Structural characterization using X-ray diffraction (XRD) shows that all samples produce a layer of Fe_3O_4 with particle size less than 50 nanometers. The addition of ethylene glycol and the heating of the sample causes a shrinkage in particle size. The scanning electron microscopy (SEM) characterization shows that Fe_3O_4 layer resulting from the process of electrodeposition of Fe_2(SO_4)_3 without ethylene glycol, independent of whether the sample is heated or not, is uneven and buildup. Layer produced by the addition of ethylene glycol without heating produces spherical particles. On contrary, when the layer is heated the spherical particles transform to irregularly-shaped particles with smaller size.

Preparation and characterization of self-assembled layer by layer NiCo2O4–reduced graphene oxide nanocomposite with improved electrocatalytic properties

International Nuclear Information System (INIS)

Srivastava, Manish; Elias Uddin, Md.; Singh, Jay; Kim, Nam Hoon; Lee, Joong Hee

2014-01-01

Graphical abstract: NiCo 2 O 4 were grown on RGO by in situ synthesis process. FE-SEM investigation revealed self assembled layer by layer growth of NiCo 2 O 4 –RGO nanocomposite. NiCo 2 O 4 –RGO nanocomposite exhibited synergetic effect of NiCo 2 O 4 nanoparticles and RGO on its electrochemical performance. -- Highlights: • NiCo 2 O 4 were grown on RGO by in-situ synthesis process. • FE-SEM image revealed self-assembled layer by layer growth of NiCo 2 O 4 -RGO nanocomposite. • NiCo 2 O 4 -RGO nanocomposite exhibited synergetic effects on its electrochemical performance. -- Abstract: NiCo 2 O 4 nanoparticles dispersed on reduced graphene oxide (RGO) are prepared by simultaneously reducing graphene oxide (GO), nickel and cobalt nitrate via a hydrothermal method assisted by post annealing at low temperature. The method involves formation of hydroxides on GO using ammonia under hydrothermal conditions. Subsequent thermal treatment at 300 °C led to the conversion of hydroxides into single-phase NiCo 2 O 4 atop the RGO. The synthesized products are characterized through several techniques including X-ray diffraction (XRD), ultraviolet–visible spectroscopy (UV–Vis), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy (RS), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The FE-SEM investigations reveal the growth of a layer by layer assembly of NiCo 2 O 4 –RGO (2:1) nanocomposite, where the NiCo 2 O 4 nanoparticles are tightly packed between the layers of RGO. Further, the catalytic properties of the NiCo 2 O 4 –RGO nanocomposite are investigated for the oxygen evolution reaction (OER) through cyclic voltammetry (CV) measurements. It is observed that the special structural features of the NiCo 2 O 4 –RGO (2:1) nanocomposite, including layer by layer assembly, integrity and excellent dispersion of the NiCo 2 O 4 nanoparticles atop the RGO, produced

Efficient removal of arsenic by strategically designed and layer-by-layer assembled PS@+rGO@GO@Fe3O4 composites.

Science.gov (United States)

Kang, Bong Kyun; Lim, Byeong Seok; Yoon, Yeojoon; Kwag, Sung Hoon; Park, Won Kyu; Song, Young Hyun; Yang, Woo Seok; Ahn, Yong-Tae; Kang, Joon-Wun; Yoon, Dae Ho

2017-10-01

The PS@+rGO@GO@Fe 3 O 4 (PG-Fe 3 O 4 ) hybrid composites for Arsenic removal were successfully fabricated and well dispersed using layer-by-layer assembly and a hydrothermal method. The PG-Fe 3 O 4 hybrid composites were composed of uniformly coated Fe 3 O 4 nanoparticles on graphene oxide layers with water flow space between 3D structures providing many contact area and adsorption sites for Arsenic adsorption. The PG-Fe 3 O 4 hybrid composite has large surface adsorption sites and exhibits high adsorption capacities of 104 mg/g for As (III) and 68 mg/g for As (V) at 25 °C and pH 7 comparison with pure Fe 3 O 4 and P-Fe 3 O 4 samples. Copyright © 2017 Elsevier Ltd. All rights reserved.

[H3N(CH2)4NH3]2[Al4(C2O4)(H2PO4)2(PO4)4].4[H2O]: A new layered aluminum phosphate-oxalate

International Nuclear Information System (INIS)

Peng Li; Li Jiyang; Yu Jihong; Li Guanghua; Fang Qianrong; Xu Ruren

2005-01-01

A new layered inorganic-organic hybrid aluminum phosphate-oxalate [H 3 N(CH 2 ) 4 NH 3 ] 2 [Al 4 (C 2 O 4 )(H 2 PO 4 ) 2 (PO 4 ) 4 ].4[H 2 O](AlPO-CJ25) has been synthesized hydrothermally, by using 1,4-diaminobutane (DAB) as structure-directing agent. The structure has been solved by single-crystal X-ray diffraction analysis and further characterized by IR, 31 P MAS NMR, TG-DTA as well as compositional analyses. Crystal data: the triclinic space group P-1, a=8.0484(7) A, b=8.8608(8) A, c=13.2224(11) A, α=80.830(6) deg. , β=74.965(5) deg. , γ=78.782(6) deg. , Z=2, R 1[ I >2 σ ( I )] =0.0511 and wR 2(alldata) =0.1423. The alternation of AlO 4 tetrahedra and PO 4 tetrahedra gives rise to the four-membered corner-sharing chains, which are interconnected through AlO 6 octahedra to form the layered structure with 4,6-net sheet. Interestingly, oxalate ions are bis-bidentately bonded by participating in the coordination of AlO 6 , and bridging the adjacent AlO 6 octahedra. The layers are held with each other through strong H-bondings between the terminal oxygens. The organic ammonium cations and water molecules are located in the large cavities between the interlayer regions. -- Graphical abstract: The alternation of AlO 4 tetrahedra and PO 4 tetrahedra gives rise to the four-membered corner-sharing chains, which are interconnected through AlO 6 octahedra to form the layered structure with 4,6-net sheet. Oxalate ions are bis-bidentately boned by participating in the coordination of AlO 6 , and bridging the adjacent AlO 6 octahedra

Early Experiences Writing Performance Portable OpenMP 4 Codes

Energy Technology Data Exchange (ETDEWEB)

Joubert, Wayne [ORNL; Hernandez, Oscar R [ORNL

2016-01-01

In this paper, we evaluate the recently available directives in OpenMP 4 to parallelize a computational kernel using both the traditional shared memory approach and the newer accelerator targeting capabilities. In addition, we explore various transformations that attempt to increase application performance portability, and examine the expressiveness and performance implications of using these approaches. For example, we want to understand if the target map directives in OpenMP 4 improve data locality when mapped to a shared memory system, as opposed to the traditional first touch policy approach in traditional OpenMP. To that end, we use recent Cray and Intel compilers to measure the performance variations of a simple application kernel when executed on the OLCF s Titan supercomputer with NVIDIA GPUs and the Beacon system with Intel Xeon Phi accelerators attached. To better understand these trade-offs, we compare our results from traditional OpenMP shared memory implementations to the newer accelerator programming model when it is used to target both the CPU and an attached heterogeneous device. We believe the results and lessons learned as presented in this paper will be useful to the larger user community by providing guidelines that can assist programmers in the development of performance portable code.

Oxide thickness measurement technique for duplex-layer Zircaloy-4 cladding

International Nuclear Information System (INIS)

McClelland, R.G.; O'Leary, P.M.

1992-01-01

Siemens Nuclear Power Corporation (SNP) is investigating the use of duplex-layer Zircaloy-4 tubing to improve the waterside corrosion resistance of cladding for high-burnup pressurized water reactor (PWR) fuel designs. Standard SNP PWR cladding is typically 0.762-mm (0.030-in.)-thick Zircaloy-4. The SNP duplex cladding is nominally 0.660-mm (0.026-in.)-thick Zircalloy-4 with an ∼0.102-mm (0.004-in.) outer layer of another, more corrosion-resistant, zirconium-based alloy. It is common industry practice to monitor the in-reactor corrosion behavior of Zircaloy cladding by using an eddy-current 'lift-off' technique to measure the oxide thickness on the outer surface of the fuel cladding. The test program evaluated three different cladding samples, all with the same outer diameter and wall thickness: Zircaloy-4 and duplex clad types D2 and D4

Modified end-to-side double-layer open pancreaticogastrostomy after Whipple procedure: surgical tips for a safe anastomosis.

Science.gov (United States)

Dalla Valle, Raffaele; Rossini, Matteo; Lamecchi, Laura; Iaria, Maurizio

2018-03-01

Pancreatic fistula (PF) remains the Achilles' heel of pancreaticoduodenectomy (PD). Pancreaticogastrostomy (PG) appears to be associated with a lower risk of postoperative leak according to recent evidence. We started to fashion PG, especially in soft pancreas, modifying the original technique described by Bassi. At our institution, 105 PD procedures were carried out from January 2011 to December 2016; pancreatic-enteric continuity was restored by PG in 35 cases. Superior mesenteric/portal vein resection/reconstruction was necessary in three patients. A total of 34/35 patients underwent PG with an open anterior gastrostomy approach. Briefly, our double-layer PG anastomosis (illustrated by a video) starts with a posterior row of interrupted absorbable 4/0 monofilament sutures including the gastric serosa and the pancreatic capsule. It is essential to mobilize the left pancreas for 4-5 cm and to shape the posterior gastrostomy shorter than the pancreatic stump. After a wide anterior auxiliary gastrostomy the pancreas is invaginated into the stomach and an interrupted row of sutures between the posterior gastric wall (full-thickness) and the body of the pancreatic stump is fashioned. The anterior gastrostomy is closed with an absorbable running suture. Finally, a further layer of sutures is applied over the posterior suture line between the gastric serosa and the pancreatic capsule. The 90-day postoperative mortality was nihil. No biliary leakage was detected and the overall PF rate was 11.4% (4/35) according to the ISGPF study group. Only one patient suffered a grade B PF (in this case, PG was carried out only through a posterior gastrostomy), whereas three patients had a minor (grade A) PF. Our modified PG proved to be safe and easy to perform, while it carried excellent outcomes even in the setting of soft pancreas. Despite the limited number of cases, such modified PG appears promising, particularly for pancreatic remnants at higher risk of PF.

Characterization of Zircaloy-4 oxide layers by impedance spectroscopy

International Nuclear Information System (INIS)

Barberis, P.

1999-01-01

Two Zircaloy-4 type alloys with different tin contents (0.5 and 1.2 wt%) have been oxidized in autoclave (400 C in steam) for several durations (1-140 days). The film has been characterized by electrochemical impedance spectroscopy (EIS). Several soaking times have been investigated (up to 40 days). The Cole-Cole representation has been used to display and study the data. A simple electrical model has been derived from the observed spectra: the electrical circuit includes two RC loops in series, whose capacitances are frequency dispersed. It is thoroughly related to the layer structure. It has been shown that even before the kinetic transition, the film is constituted of three parts: an inner layer which is compact, an outer layer subdivided in an external region immediately soaked by the electrolyte, and an internal one in which electrolyte diffusion processes can take place. The kinetic transition is interpreted in terms of an abrupt 'compacity' change, both layers degrading at this point. The alloy with high tin content exhibits higher dispersive properties of the oxide layer formed on it, in correlation with its faster oxidation kinetics. (orig.)

Impact of annealing treatment before buffer layer deposition on Cu2ZnSn(S,Se)4 solar cells

International Nuclear Information System (INIS)

Hironiwa, Daisuke; Sakai, Noriyuki; Kato, Takuya; Sugimoto, Hiroki; Tang, Zeguo; Chantana, Jakapan; Minemoto, Takashi

2015-01-01

Cu 2 ZnSn(S,Se) 4 (CZTSSe) solar cells were fabricated with an annealing treatment before the deposition of buffer layers to improve their photovoltaic performance. The CZTSSe absorbers were produced by sulfurization and selenization of metallic precursors. The efficiency of the solar cells increased from 5.5% without the annealing treatment to 8.8% with the annealing treatment at a temperature of 200 °C before buffer layer fabrication. Photoluminescence (PL) measurements revealed that the density of defects in the CZTSSe absorber that acted as non-radiative recombination centers decreased with the annealing treatment. The PL peak intensity exhibited a linear relationship with the open circuit voltage and the fill factor. In addition, the carrier density and hole mobility of the CZTSSe absorbers, which were respectively investigated by capacitance-voltage and Hall effect measurements, increased with the annealing treatment, thus improving cell performance. - Highlights: • Cu 2 ZnSn(S,Se) 4 is fabricated by sulfurization and selenization. • The annealing treatment can effectively improve the cell performance. • The defect acting as recombination is decreased by annealing treatment. • Carrier density and hole mobility is increased by annealing treatment

Atomic Layer Deposition of Stable LiAlF4 Lithium Ion Conductive Interfacial Layer for Stable Cathode Cycling.

Science.gov (United States)

Xie, Jin; Sendek, Austin D; Cubuk, Ekin D; Zhang, Xiaokun; Lu, Zhiyi; Gong, Yongji; Wu, Tong; Shi, Feifei; Liu, Wei; Reed, Evan J; Cui, Yi

2017-07-25

Modern lithium ion batteries are often desired to operate at a wide electrochemical window to maximize energy densities. While pushing the limit of cutoff potentials allows batteries to provide greater energy densities with enhanced specific capacities and higher voltage outputs, it raises key challenges with thermodynamic and kinetic stability in the battery. This is especially true for layered lithium transition-metal oxides, where capacities can improve but stabilities are compromised as wider electrochemical windows are applied. To overcome the above-mentioned challenges, we used atomic layer deposition to develop a LiAlF 4 solid thin film with robust stability and satisfactory ion conductivity, which is superior to commonly used LiF and AlF 3 . With a predicted stable electrochemical window of approximately 2.0 ± 0.9 to 5.7 ± 0.7 V vs Li + /Li for LiAlF 4 , excellent stability was achieved for high Ni content LiNi 0.8 Mn 0.1 Co 0.1 O 2 electrodes with LiAlF 4 interfacial layer at a wide electrochemical window of 2.75-4.50 V vs Li + /Li.

HTS microstrip disk resonator with an upper dielectric layer for 4GHz

International Nuclear Information System (INIS)

Yamanaka, Kazunori; Kai, Manabu; Akasegawa, Akihiko; Nakanishi, Teru

2006-01-01

We propose HTS microstrip disk resonator with an upper dielectric layer as a candidate resonator structure of HTS compact power filter for 4GHz band. The electromagnetic simulations on the upper dielectric layer examined the current distributions of the HTS resonators that had TM 11 mode resonance of about 4 GHz. By the simulations, it is evaluated that of the maximum current density near the end portion of the disk-shape pattern of the resonator with the thick upper-layered structure decreases by roughly 30-50 percent, as compared with that of the resonator without it. Then, we designed and fabricated the resonator samples with and without the upper dielectrics. The RF power measurement results indicated that the upper dielectric layer leads to an increase in handling power

The effect of a defective BSF layer on solar cell open circuit voltage. [Back Surface Field

Science.gov (United States)

Weizer, V. G.

1985-01-01

A straightforward analysis of special limiting cases has permitted the determination of the range of possible open circuit voltage losses due to a defective BSF (back surface field) layer. An important result of the analysis is the finding that it is possible to have a fully effective BSF region, regardless of the spatial distribution of the defective areas, as long as the total defective area is reduced below certain limits. Distributed defects were found to be much more harmful than lumped defects.

An expression for the water-sediment moving layer in unsteady flows valid for open channels and embankments

Directory of Open Access Journals (Sweden)

A. M. Berta

2010-05-01

Full Text Available During the floods, the effects of sediment transport in river beds are particulary significant and can be studied through the evolution of the water-sediment layer which moves in the lower part of a flow, named "moving layer". Moving layer variations along rivers lead to depositions and erosions and are typically unsteady, but are often tackled with expressions developed for steady (equilibrium conditions. In this paper, we develop an expression for the moving layer in unsteady conditions and calibrate it with experimental data. During laboratory tests, we have in fact reproduced a rapidly changing unsteady flow by the erosion of a granular steep slope. Results have shown a clear tendency of the moving layer, for fixed discharges, toward equilibrium conditions. Knowing the equilibrium achievement has presented many difficulties, being influenced by the choice of the equilibrium expression and moreover by the estimation of the parameters involved (for example friction angle. Since we used only data relevant to hyper-concentrated mono-dimensional flows for the calibration – occurring for slope gradients in the range 0.03–0.20 – our model can be applied both on open channels and on embankments/dams, providing that the flows can be modelled as mono-dimensional, and that slopes and applied shear stress levels fall within the considered ranges.

Excited states of open strings from N=4 SYM

International Nuclear Information System (INIS)

Dzienkowski, Eric

2015-01-01

We continue the analysis of building open strings stretched between giant gravitons from N=4 SYM by going to second order in perturbation theory using the three-loop dilatation generator from the field theory. In the process we build a Fock-like space of states using Cuntz oscillators which can be used to access the excited open string states. We find a remarkable cancellation among the excited states that shows the ground state energy is consistent with a fully relativistic dispersion relation.

Characteristics of Ni-Cr-Fe laser clad layers on EA4T steel

Science.gov (United States)

Chen, Wenjing; Chen, Hui; Wang, Yongjing; Li, Congchen; Wang, Xiaoli

2017-07-01

The Ni-Cr-Fe metal powder was deposited on EA4T steel by laser cladding technology. The microstructure and chemical composition of the cladding layer were analyzed by optical microscopy (OM), scanning electron microscopy (SEM) and X-ray diffraction (XRD). The bonding ability between the cladding layer and the matrix was measured. The results showed that the bonding between the cladding layer and the EA4T steel was metallurgical bonding. The microstructure of cladding layer was composed of planar crystals, columnar crystals and dendrite, which consisted of Cr2Ni3, γ phase, M23C6 and Ni3B phases. When the powder feeding speed reached 4 g/min, the upper bainite occurred in the heat affected zone (HAZ). Moreover, the tensile strength of the joint increased, while the yield strength and the ductility decreased.

Ionothermal synthesis of open-framework metal phosphates with a Kagomé lattice network exhibiting canted anti-ferromagnetism† †Electronic supplementary information (ESI) available: Cif files, atomic parameters, X-ray diffraction patterns, IR spectra, TG curves, and thermal ellipsoid plot and atomic label schemes of compound 1–4. See DOI: 10.1039/c4tc00290c Click here for additional data file.

Science.gov (United States)

Wang, Guangmei; Valldor, Martin; Mallick, Bert

2014-01-01

Four open-framework transition-metal phosphates; (NH4)2Co3(HPO4)2F4 (1), (NH4)Co3(HPO4)2(H2PO4)F2 (2), KCo3(HPO4)2(H2PO4)F2 (3), and KFe3(HPO4)2(H2PO4)F2 (4); are prepared by ionothermal synthesis using pyridinium hexafluorophosphate as the ionic liquid. Single-crystal X-ray diffraction analyses reveal that the four compounds contain cobalt/iron–oxygen/fluoride layers with Kagomé topology composed of interlinked face-sharing MO3F3/MO4F2 octahedra. PO3OH pseudo-tetrahedral groups augment the [M3O6F4] (1)/[M3O8F2] layers on both sides to give M3(HPO4)2F4 (1) and M3(HPO4)2F2 (2–4) layers. These layers are stacked along the a axis in a sequence AA…, resulting in the formation of a layer structure for (NH4)2Co3(HPO4)2F4(1). In NH4Co3(HPO4)2(H2PO4)F2 and KM3(HPO4)2(H2PO4)F2, the M3(HPO4)2F2 layers are stacked along the a axis in a sequence AAi… and are connected by [PO3(OH)] tetrahedra, giving rise to a 3-D open framework structure with 10-ring channels along the [001] direction. The negative charges of the inorganic framework are balanced by K+/NH4 + ions located within the channels. The magnetic transition metal cations themselves form layers with stair-case Kagomé topology. Magnetic susceptibility and magnetization measurements reveal that all four compounds exhibit a canted anti-ferromagnetic ground state (T c = 10 or 13 K for Co and T c = 27 K for Fe) with different canting angles. The full orbital moment is observed for both Co2+ and Fe2+. PMID:25580250

Reliably counting atomic planes of few-layer graphene (n > 4).

Science.gov (United States)

Koh, Yee Kan; Bae, Myung-Ho; Cahill, David G; Pop, Eric

2011-01-25

We demonstrate a reliable technique for counting atomic planes (n) of few-layer graphene (FLG) on SiO(2)/Si substrates by Raman spectroscopy. Our approach is based on measuring the ratio of the integrated intensity of the G graphene peak and the optical phonon peak of Si, I(G)/I(Si), and is particularly useful in the range n > 4 where few methods exist. We compare our results with atomic force microscopy (AFM) measurements and Fresnel equation calculations. Then, we apply our method to unambiguously identify n of FLG devices on SiO(2) and find that the mobility (μ ≈ 2000 cm(2) V(-1) s(-1)) is independent of layer thickness for n > 4. Our findings suggest that electrical transport in gated FLG devices is dominated by carriers near the FLG/SiO(2) interface and is thus limited by the environment, even for n > 4.

A double B1-mode 4-layer laminated piezoelectric linear motor.

Science.gov (United States)

Li, Xiaotian; Chen, Zhijiang; Dong, Shuxiang

2012-12-01

We report a miniature piezoelectric ultrasonic linear motor that is made of four Pb(Zr,Ti)O(3) (PZT) piezoelectric ceramic layers for low-voltage work. The 4-layer piezoelectric laminate works in two orthogonal first-bending modes for producing elliptical oscillations, which are then used to drive a contacting slider into continuous linear motion. Experimental results show that the miniature linear motor (size: 4 × 4 × 12 mm, weight: 1.7 g) can generate a large driving force of 0.48 N and a linear motion speed of up to 160 mm/s, using a 40 V(pp)/mm voltage drive at its resonance frequency of 64.5 kHz. The maximum efficiency of the linear motor is 30%.

Improvement of photoluminescence from Ge layer with patterned Si{sub 3}N{sub 4} stressors

Energy Technology Data Exchange (ETDEWEB)

Oda, Katsuya, E-mail: Katsuya.Oda.cb@hitachi.com; Okumura, Tadashi; Tani, Kazuki; Saito, Shin-ichi; Ido, Tatemi

2014-04-30

Lattice strain applied by patterned Si{sub 3}N{sub 4} stressors in order to improve the optical properties of Ge layers directly grown on a Si substrate was investigated. Patterned Si{sub 3}N{sub 4} stressors were fabricated by various methods and their effects on the strain and photoluminescence were studied. Although we found that when the stressor was fabricated by thermal chemical vapor deposition (CVD), the Ge waveguide was tensilely and compressively strained in the edge and center positions, respectively, and photoluminescence (PL) could be improved by decreasing the width of the waveguide, the crystallinity of the Ge waveguide was degraded by the thermal impact of the deposition process. Low-temperature methods were therefore used to make the patterned stressors. The tensile strain of the Ge layer increased from 0.14% to 0.2% when the stressor was grown by plasma enhanced CVD at 350 °C, but the effects of the increased tensile strain could not be confirmed because the Si{sub 3}N{sub 4} layer was unstable when irradiated with the excitation light used in photoluminescence measurements. Si{sub 3}N{sub 4} stressors grown by inductively coupled plasma CVD at room temperature increased the tensile strain of the Ge layer up to 0.4%, thus red-shifting the PL peak and obviously increasing the PL intensity. These results indicate that the Si{sub 3}N{sub 4} stressors fabricated by the room-temperature process efficiently improve the performance of Ge light-emitting devices. - Highlights: • Ge layers were directly grown on a Si substrate by low-temperature epitaxial growth. • Si{sub 3}N{sub 4} stressors were fabricated on the Ge layers by various methods. • Tensile strain of the Ge layers was improved by the Si{sub 3}N{sub 4} stressors. • Photoluminescence (PL) intensity was increased with the Si{sub 3}N{sub 4} stressors. • Red-shift of the PL spectra was observed from the tensile strained Ge layers.

Preparation and characterization of self-assembled layer by layer NiCo{sub 2}O{sub 4}–reduced graphene oxide nanocomposite with improved electrocatalytic properties

Energy Technology Data Exchange (ETDEWEB)

Srivastava, Manish; Elias Uddin, Md. [Advanced Materials Research Institute for BIN Fusion Technology (BK Plus Global Program), Department of BIN Fusion Technology, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of); Singh, Jay [Department of Applied Chemistry, Delhi Technological University, Shahbad Daulatpur, Main Bawana Road, Delhi 110042 (India); Kim, Nam Hoon [Advanced Materials Research Institute for BIN Fusion Technology (BK Plus Global Program), Department of BIN Fusion Technology, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of); Lee, Joong Hee, E-mail: jhl@chonbuk.ac.kr [Advanced Materials Research Institute for BIN Fusion Technology (BK Plus Global Program), Department of BIN Fusion Technology, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of); Advanced Wind Power System Research Center, Department of Polymer and Nano Engineering, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of)

2014-03-25

Graphical abstract: NiCo{sub 2}O{sub 4} were grown on RGO by in situ synthesis process. FE-SEM investigation revealed self assembled layer by layer growth of NiCo{sub 2}O{sub 4}–RGO nanocomposite. NiCo{sub 2}O{sub 4}–RGO nanocomposite exhibited synergetic effect of NiCo{sub 2}O{sub 4} nanoparticles and RGO on its electrochemical performance. -- Highlights: • NiCo{sub 2}O{sub 4} were grown on RGO by in-situ synthesis process. • FE-SEM image revealed self-assembled layer by layer growth of NiCo{sub 2}O{sub 4}-RGO nanocomposite. • NiCo{sub 2}O{sub 4}-RGO nanocomposite exhibited synergetic effects on its electrochemical performance. -- Abstract: NiCo{sub 2}O{sub 4} nanoparticles dispersed on reduced graphene oxide (RGO) are prepared by simultaneously reducing graphene oxide (GO), nickel and cobalt nitrate via a hydrothermal method assisted by post annealing at low temperature. The method involves formation of hydroxides on GO using ammonia under hydrothermal conditions. Subsequent thermal treatment at 300 °C led to the conversion of hydroxides into single-phase NiCo{sub 2}O{sub 4} atop the RGO. The synthesized products are characterized through several techniques including X-ray diffraction (XRD), ultraviolet–visible spectroscopy (UV–Vis), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy (RS), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The FE-SEM investigations reveal the growth of a layer by layer assembly of NiCo{sub 2}O{sub 4}–RGO (2:1) nanocomposite, where the NiCo{sub 2}O{sub 4} nanoparticles are tightly packed between the layers of RGO. Further, the catalytic properties of the NiCo{sub 2}O{sub 4}–RGO nanocomposite are investigated for the oxygen evolution reaction (OER) through cyclic voltammetry (CV) measurements. It is observed that the special structural features of the NiCo{sub 2}O{sub 4}–RGO (2:1) nanocomposite, including

Low-latitude boundary layer near noon: An open field line model

Science.gov (United States)

Lyons, L. R.; Schulz, M.; Pridmore-Brown, D. C.; Roeder, J. L.

1994-01-01

We propose that many features of the cusp and low-latitude boundary layer (LLBL) observed near noon MLT can be explained by interpreting the LLBL as being on open lines with an inner boundary at the separatrix between open and closed magnetic field lines. This interpretation places the poleward boundary of the LLBL and equatorward boundary of the cusp along the field line that bifurcates at the cusp neutral point. The interpretation accounts for the abrupt boundary of magnetosheath particles at the inner edge of the LLBL, a feature that is inconsistent with LLBL formation by diffusion onto closed field lines, and for the distribution of magnetosheath particles appearing more as one continuous region than as two distinct regions across the noon cusp/LLBL boundary. Furthermore, we can explain the existence of energetic radiation belt electrons and protons with differing pitch angle distributions within the LLBL and their abrupt cutoff at the poleward boundary of the LLBL. By modeling the LLBL and cusp region quantitatively, we can account for a hemispherical difference in the location of the equatorial boundary of the cusp that is observed to be dependent on the dipole tilt angle but not on the interplanetary magnetic field (IMF) x component. We also find important variations and hemispherical differences in that the size of the LLBL that should depend strongly upon the x component of the IMF. This prediction is observationally testable. Finally, we find that when the IMF is strongly northward, the LLBL may include a narrow region adjacent to the magnetopause where field lines are detached (i.e., have both ends connected to the IMF).

Low Homologous Temperature (0.2) Sputtering of Indium Films on Silicon (POSTPRINT)

Science.gov (United States)

2012-09-24

to the difficulty in recycling lead-containing products.3 Hard solders such as AuSn perform well in lifetime tests,4 but their thermal conductivity...ROIC) to form focal plane arrays (FPAs)7 as well as some high power devi- ces such as power amplifiers or large area lasers with heat spreaders .8 In

Numerical Study on Open-Circuit Voltage of Single Layer Organic Solar Cells with Schottky Contacts: Effects of Molecular Energy Levels, Temperature and Thickness

International Nuclear Information System (INIS)

Rong-Hua, Li; Ying-Quan, Peng; Chao-Zhu, Ma; Run-Sheng, Wang; Hong-Wei, Xie; Ying, Wang; Wei-Min, Meng

2010-01-01

We numerically investigate the effects of the exciton generation rate G, temperature T, the active layer thickness d and the position of LUMO level E L related to the cathode work function W c at a given energy gap on the open-circuit voltage V oc of single layer organic solar cells with Schottky contact. It is demonstrated that open-circuit voltage increases concomitantly with the decreasing cathode work function W c for given anode work functions and exciton generation rates. In the case of given cathode and anode work functions, the open-circuit voltage first increases with the exciton generation rate and then reaches a saturation value, which equals to the built-in voltage. Additionally, it is worth noting that a significant improvement to V oc could be made by selecting an organic material which has a relative high LUMO level (low |E L | value). However, V oc decreases as the temperature increases, and the decreasing rate reduces with the enhancement of exciton generation rate. Our study also shows that it is of no benefit to improve the open-circuit voltage by increasing the device thickness because of an enhanced charge recombination in thicker devices. (cross-disciplinary physics and related areas of science and technology)

Quadruple-layered perovskite (CuCl)Ca2NaNb4O13

International Nuclear Information System (INIS)

Kitada, A.; Tsujimoto, Y.; Yamamoto, T.; Kobayashi, Y.; Narumi, Y.; Kindo, K.; Aczel, A.A.; Luke, G.M.; Uemura, Y.J.; Kiuchi, Y.; Ueda, Y.; Yoshimura, K.; Ajiro, Y.; Kageyama, H.

2012-01-01

We will present the synthesis, structure and magnetic properties of a new quadruple-layered perovskite (CuCl)Ca 2 NaNb 4 O 13 . Through a topotactic ion-exchange reaction with CuCl 2 , the precursor RbCa 2 NaNb 4 O 13 presumably having an incoherent octahederal tliting changes into (CuCl)Ca 2 NaNb 4 O 13 with a 2a p ×2a p ×2c p superstructure (tetragonal; a=7.73232(5) Å, c=39.2156(4) Å). The well-defined superstructure for the ion-exchanged product should be stabilized by the inserted CuCl 4 O 2 octahedral layers that firmly connect with neighboring perovskite layers. Magnetic studies show the absence of long-range magnetic ordering down to 2 K despite strong in-plane interactions. Aleksandrov′s group theory and Rietveld refinement of synchrotron X-ray diffraction data suggest the structure to be of I4/mmm space group with in-phase tilting along the a and b axes, a two-tilt system (++0). - Graphical Abstract: We present a quadruple-layered copper oxyhalide (CuCl)Ca 2 NaNb 4 O 13 synthesized through a topotactic ion-exchange reaction of RbCa 2 NaNb 4 O 13 with CuCl 2 . The compound has a well-defined superstructure. Magnetic studies suggest the absence of magnetic order even at 2 K. Highlights: ► (CuCl)Ca 2 NaNb 4 O 13 was prepared by ion-exchange reaction of RbCa 2 NaNb 4 O 13 with CuCl 2 . ► Compound has a 2a p ×2a p ×2c p superstructure (tetragonal; a=7.73 Å, c=39.21 Å). ► Such a well-defined superstructure was not observed in the precursor compound. ► Aleksandrov′s theory and Rietveld study suggest a (++0) octahedral tilting (I4/mmm). ► Magnetic studies revealed the absence of magnetic order down to 2 K.

Comparative study of the retinal nerve fibre layer thickness performed with optical coherence tomography and GDx scanning laser polarimetry in patients with primary open-angle glaucoma.

Science.gov (United States)

Wasyluk, Jaromir T; Jankowska-Lech, Irmina; Terelak-Borys, Barbara; Grabska-Liberek, Iwona

2012-03-01

We compared the parameters of retinal nerve fibre layer in patients with advanced glaucoma with the use of different OCT (Optical Coherence Tomograph) devices in relation to analogical measurements performed with GDx VCC (Nerve Fiber Analyzer with Variable Corneal Compensation) scanning laser polarimetry. Study subjects had advanced primary open-angle glaucoma, previously treated conservatively, diagnosed and confirmed by additional examinations (visual field, ophthalmoscopy of optic nerve, gonioscopy), A total of 10 patients were enrolled (9 women and 1 man), aged 18-70 years of age. Nineteen eyes with advanced glaucomatous neuropathy were examined. 1) Performing a threshold perimetry Octopus, G2 strategy and ophthalmoscopy of optic nerve to confirm the presence of advanced primary open-angle glaucoma; 2) performing a GDx VCC scanning laser polarimetry of retinal nerve fibre layer; 3) measuring the retinal nerve fibre layer thickness with 3 different optical coherence tomographs. The parameters of the retinal nerve fibre layer thickness are highly correlated between the GDx and OCT Stratus and 3D OCT-1000 devices in mean retinal nerve fibre layer thickness, retinal nerve fibre layer thickness in the upper sector, and correlation of NFI (GDx) with mean retinal nerve fibre layer thickness in OCT examinations. Absolute values of the retinal nerve fibre layer thickness (measured in µm) differ significantly between GDx and all OCT devices. Examination with OCT devices is a sensitive diagnostic method of glaucoma, with good correlation with the results of GDx scanning laser polarimetry of the patients.

Thinning and functionalization of few-layer graphene sheets by CF4 plasma treatment

KAUST Repository

Shen, Chao

2012-05-24

Structural changes of few-layer graphene sheets induced by CF4 plasma treatment are studied by optical microscopy and Raman spectroscopy, together with theoretical simulation. Experimental results suggest a thickness reduction of few-layer graphene sheets subjected to prolonged CF4 plasma treatment while plasma treatment with short time only leads to fluorine functionalization on the surface layer by formation of covalent bonds. Raman spectra reveal an increase in disorder by physical disruption of the graphene lattice as well as functionalization during the plasma treatment. The F/CF3 adsorption and the lattice distortion produced are proved by theoretical simulation using density functional theory, which also predicts p-type doping and Dirac cone splitting in CF4 plasma-treated graphene sheets that may have potential in future graphene-based micro/nanodevices.

Macular Choroidal Small-Vessel Layer, Sattler's Layer and Haller's Layer Thicknesses: The Beijing Eye Study.

Science.gov (United States)

Zhao, Jing; Wang, Ya Xing; Zhang, Qi; Wei, Wen Bin; Xu, Liang; Jonas, Jost B

2018-03-13

To study macular choroidal layer thickness, 3187 study participants from the population-based Beijing Eye Study underwent spectral-domain optical coherence tomography with enhanced depth imaging for thickness measurements of the macular small-vessel layer, including the choriocapillaris, medium-sized choroidal vessel layer (Sattler's layer) and large choroidal vessel layer (Haller's layer). In multivariate analysis, greater thickness of all three choroidal layers was associated (all P  0.05) associated with the prevalence of open-angle glaucoma or diabetic retinopathy. There was a tendency (0.07 > P > 0.02) toward thinner choroidal layers in chronic angle-closure glaucoma. The ratio of small-vessel layer thickness to total choroidal thickness increased (P layer and Haller's layer thickness to total choroidal thickness decreased. A higher ratio of small-vessel layer thickness to total choroidal thickness was significantly associated with a lower prevalence of AMD (early type, intermediate type, late geographic type). Axial elongation-associated and aging-associated choroidal thinning affected Haller's and Sattler's layers more markedly than the small-vessel layer. Non-exudative and exudative AMD, except for geographic atrophy, was associated with slightly increased choroidal thickness.

Design Of A Bi-Functional α-Fe2O3/Zn2SiO4:Mn2+ By Layer-By-Layer Assembly Method

Directory of Open Access Journals (Sweden)

Yu Ri

2015-06-01

Full Text Available This work describes the design of bi-functional α-Fe2O3/Zn2SiO4:Mn2+ using a two-step coating process. We propose a combination of pigments (α-Fe2O3 and phosphor (Zn2SiO4:Mn2+ glaze which is assembled using a layer-by-layer method. A silica-coated α-Fe2O3 pigment was obtained by a sol-gel method and a Zn2+ precursor was then added to the silica-coated α-Fe2O3 to create a ZnO layer. Finally, the Zn2SiO4:Mn2+ layer was prepared with the addition of Mn2+ ions to serve as a phosphor precursor in the multi-coated α-Fe2O3, followed by annealing at a temperature above 1000°C. Details of the phase structure, color and optical properties of the multi-functional α-Fe2O3/Zn2SiO4:Mn2+ were characterized by transmission electron microscopy and X-ray diffraction analyses.

Comparison of 4-Layer Bandages and an Adaptive Compression Therapy Device on Intended Pressure Delivery.

Science.gov (United States)

Mayrovitz, Harvey N; Partsch, Hugo; Vanscheidt, Wolfgang

2015-01-01

To characterize and compare interface pressure profiles of an adaptive compression therapy (ACT) device and a traditional 4-layer bandage (4LB) system. A prospective, randomized, open-label, 1-arm, active controlled study. The sample comprised 12 healthy volunteers. Subjects wore both devices for 8 hours on 3 consecutive days. Treatments were randomized to left and right legs. One clinician performed all applications and was experienced in the clinical use of both devices. Pressures were measured in seated and standing positions at the lower, mid, and upper calf immediately post application and after 1, 4, and 8 hours. Pressures achieved with the ACT were closer to targeted 40/30/20 mmHg graduated pressure values and were significantly less than the 4LB for corresponding sites/postures (P pressures (mean ± SD) for the ACT were 36.9 ± 4.9, 30.5 ± 4.5, and 21.0 ± 3.6 mmHg. Corresponding interface pressures for the 4LB were 52.5 ± 8.4, 57.5 ± 10.3, and 53.5 ± 12.9 mmHg. In the standing position, initial interface pressures for the ACT were 40.7 ± 4.8, 35.6 ± 4.5, and 21.1 ± 4.6 compared to 54.6 ± 12.5, 64.4 ± 10.9, and 53.7 ± 14.3 for the 4LB. At 1, 4, and 8 hours after application, the 4LB showed a significant progressive decline in interface pressure in both seated and standing positions (P pressures than the 4LB and the pressures achieved were consistent with contemporary venous ulcer therapy standards.

4-Amino-1,2,4-triazole: Playing a key role in the chemical deposition of Cu-In-Ga metal layers for photovoltaic applications

Energy Technology Data Exchange (ETDEWEB)

Berner, Ulrich, E-mail: ulrich.berner@de.bosch.com [Robert Bosch GmbH, Corporate Sector Research and Advance Engineering, Applied Research Chemistry (CR/ARC), Robert Bosch Platz 1, 70839 Gerlingen-Schillerhöhe (Germany); Physics and Materials Science Research Unit, Université du Luxembourg, 41, rue du Brill, L-4422 Belvaux (Luxembourg); Widenmeyer, Markus; Engler, Patrick [Robert Bosch GmbH, Corporate Sector Research and Advance Engineering, Applied Research Chemistry (CR/ARC), Robert Bosch Platz 1, 70839 Gerlingen-Schillerhöhe (Germany); Dale, Phillip J. [Physics and Materials Science Research Unit, Université du Luxembourg, 41, rue du Brill, L-4422 Belvaux (Luxembourg)

2015-05-01

Liquid film processing of Cu(In,Ga)Se{sub 2} absorber layers has the potential to lower the cell production costs significantly namely because of the absence of vacuum steps and high material utilization. In this work an ink system based on metal carboxylates in a mixture of a nitrogen-containing base and an alcohol is investigated. After the coating step on a suitable substrate followed by the drying of the alcohol, the metal ions are reduced to the respective metals with a simple heat treatment. However, depending on the conditions, the resulting metal layers are either highly porous or dewetting above 160 °C due to the high surface tension of the intermediate liquid indium. Adding 4-amino-1,2,4-triazole to the ink leads to a homogeneous metal layer, which is crucial for the formation of dense chalcopyrite layers. We propose a stabilization mechanism based on a temporary polymeric complex of Cu{sup 2+} and the additive 4-amino-1,2,4-triazole which is decomposing completely at selenization conditions. - Highlights: • Influence of 4-amino-1,2,4-triazole on the film formation has been investigated. • Two polymers identified forming an organic matrix during the layer processing • This matrix allows processing of dense and crack free metallic layers. • The polymers decompose completely under selenization conditions.

Zn(3)(4-OOCC(6)H(4)PO(3))(2): A polar metal phosphonate with pillared layered structure showing SHG-activity and large dielectric anisotropy.

Science.gov (United States)

Li, Jin-Tang; Cao, Deng-Ke; Akutagawa, Tomoyuki; Zheng, Li-Min

2010-10-07

A new metal phosphonate Zn(3)(4-OOCC(6)H(4)PO(3))(2) (1) is reported which crystallizes in orthorhombic space group Pca2(1). It shows a pillared layered structure in which the {ZnO(4)}, {ZnO(5)} and {PO(3)C} polyhedra are connected through corner- or edge-sharing to form an inorganic layer in the ab plane which contains 4- and 5-member rings. These layers are pillared by the uni-oriented 4-carboxylatephenylphosphonate ligands, thus leading to a polar 3D architecture. The dielectric anisotropy measurements of a single crystal of 1 reveal that dielectric constant along the inter-layer is larger than that along the intra-layer with a ratio of about 2.3. Second harmonic generation (SHG) activity is observed.

Full Multilayer Laue Lens for Focusing Hard X-rays

International Nuclear Information System (INIS)

Liu Chian; Shi, B.; Qian, J.; Conley, R.; Yan, H.; Wieczorek, M.; Macrander, A. T.; Maser, J.; Stephenson, G. B.

2010-01-01

Multilayer Laue Lenses (MLLs) were developed by us using dynamic diffraction effects to efficiently focus hard x-rays to very small spots. Using a partial MLL we were able to focus 19.5-keV hard x-rays to a line focus of 16 nm with an efficiency of 31%. A full MLL is a complete linear MLL structure. It can be fabricated by bonding two partial MLL wafers, or by growing the full structure using magnetron sputtering without bonding. A 40-μm full MLL, with a total of 5166 layers of WSi 2 and Si, has been successfully grown by sputter deposition. The layer thicknesses gradually vary from 4 nm to ∼400 nm and then back to 4 nm. Two coating runs were used to grow the full structure, one for each half. It took over 56 h for each run. A 100-μm nearly-full MLL was constructed by bonding. Each 50-μm half-structure has 1788 WSi 2 and Si layers with 12-nm to ∼32-nm thicknesses and ∼32-μm total thickness, followed by a thick WSi 2 layer of ∼17 μm, and an AuSn layer of ∼1 μm. Both full MLL structures survived dicing and polishing. The primary results demonstrate the feasibility and potential of a full MLL with a doubled numerical aperture and large beam acceptance for hard x-rays.

Finding the lost open-circuit voltage in polymer solar cells by UV-ozone treatment of the nickel acetate anode buffer layer.

Science.gov (United States)

Wang, Fuzhi; Sun, Gang; Li, Cong; Liu, Jiyan; Hu, Siqian; Zheng, Hua; Tan, Zhan'ao; Li, Yongfang

2014-06-25

Efficient polymer solar cells (PSCs) with enhanced open-circuit voltage (Voc) are fabricated by introducing solution-processed and UV-ozone (UVO)-treated nickel acetate (O-NiAc) as an anode buffer layer. According to X-ray photoelectron spectroscopy data, NiAc partially decomposed to NiOOH during the UVO treatment. NiOOH is a dipole species, which leads to an increase in the work function (as confirmed by ultraviolet photoemission spectroscopy), thus benefitting the formation of ohmic contact between the anode and photoactive layer and leading to increased Voc. In addition, the UVO treatment improves the wettability between the substrate and solvent of the active layer, which facilitates the formation of an upper photoactive layer with better morphology. Further, the O-NiAc layer can decrease the series resistance (Rs) and increase the parallel resistance (Rp) of the devices, inducing enhanced Voc in comparison with the as-prepared NiAc-buffered control devices without UVO treatment. For PSCs based on the P3HT:PCBM system, Voc increases from 0.50 to 0.60 V after the NiAc buffer layer undergoes UVO treatment. Similarly, in the P3HT:ICBA system, the Voc value of the device with a UVO-treated NiAc buffer layer increases from 0.78 to 0.88 V, showing an enhanced power conversion efficiency of 6.64%.

Integrating pipeline data management application and Google maps dataset on web based GIS application unsing open source technology Sharp Map and Open Layers

Energy Technology Data Exchange (ETDEWEB)

Wisianto, Arie; Sania, Hidayatus [PT PERTAMINA GAS, Bontang (Indonesia); Gumilar, Oki [PT PERTAMINA GAS, Jakarta (Indonesia)

2010-07-01

PT Pertamina Gas operates 3 pipe segments carrying natural gas from producers to PT Pupuk Kaltim in the Kalimantan area. The company wants to build a pipeline data management system consisting of pipeline facilities, inspections and risk assessments which would run on Geographic Information Systems (GIS) platforms. The aim of this paper is to present the integration of the pipeline data management system with GIS. A web based GIS application is developed using the combination of Google maps datasets with local spatial datasets. In addition, Open Layers is used to integrate pipeline data model and Google Map dataset into a single map display on Sharp Map. The GIS based pipeline data management system developed herein constitutes a low cost, powerful and efficient web based GIS solution.

Effect of the CO2/SiH4 Ratio in the p-μc-SiO:H Emitter Layer on the Performance of Crystalline Silicon Heterojunction Solar Cells

Directory of Open Access Journals (Sweden)

Jaran Sritharathikhun

2014-01-01

Full Text Available This paper reports the preparation of wide gap p-type hydrogenated microcrystalline silicon oxide (p-μc-SiO:H films using a 40 MHz very high frequency plasma enhanced chemical vapor deposition technique. The reported work focused on the effects of the CO2/SiH4 ratio on the properties of p-μc-SiO:H films and the effectiveness of the films as an emitter layer of crystalline silicon heterojunction (c-Si-HJ solar cells. A p-μc-SiO:H film with a wide optical band gap (E04, 2.1 eV, can be obtained by increasing the CO2/SiH4 ratio; however, the tradeoff between E04 and dark conductivity must be considered. The CO2/SiH4 ratio of the p-μc-SiO:H emitter layer also significantly affects the performance of the solar cells. Compared to the cell using p-μc-Si:H (CO2/SiH4 = 0, the cell with the p-μc-SiO:H emitter layer performs more efficiently. We have achieved the highest efficiency of 18.3% with an open-circuit voltage (Voc of 692 mV from the cell using the p-μc-SiO:H layer. The enhancement in the Voc and the efficiency of the solar cells verified the potential of the p-μc-SiO:H films for use as the emitter layer in c-Si-HJ solar cells.

Detector normalization and scatter correction for the jPET-D4: A 4-layer depth-of-interaction PET scanner

Energy Technology Data Exchange (ETDEWEB)

Kitamura, Keishi [Shimadzu Corporation, 1 Nishinokyo-Kuwabaracho, Nakagyo-ku, Kyoto-shi, Kyoto 604-8511 (Japan)]. E-mail: kitam@shimadzu.co.jp; Ishikawa, Akihiro [Shimadzu Corporation, 1 Nishinokyo-Kuwabaracho, Nakagyo-ku, Kyoto-shi, Kyoto 604-8511 (Japan); Mizuta, Tetsuro [Shimadzu Corporation, 1 Nishinokyo-Kuwabaracho, Nakagyo-ku, Kyoto-shi, Kyoto 604-8511 (Japan); Yamaya, Taiga [National Institute of Radiological Sciences, 9-1 Anagawa-4, Inage-ku, Chiba-shi, Chiba 263-8555 (Japan); Yoshida, Eiji [National Institute of Radiological Sciences, 9-1 Anagawa-4, Inage-ku, Chiba-shi, Chiba 263-8555 (Japan); Murayama, Hideo [National Institute of Radiological Sciences, 9-1 Anagawa-4, Inage-ku, Chiba-shi, Chiba 263-8555 (Japan)

2007-02-01

The jPET-D4 is a brain positron emission tomography (PET) scanner composed of 4-layer depth-of-interaction (DOI) detectors with a large number of GSO crystals, which achieves both high spatial resolution and high scanner sensitivity. Since the sensitivity of each crystal element is highly dependent on DOI layer depth and incidental {gamma} ray energy, it is difficult to estimate normalization factors and scatter components with high statistical accuracy. In this work, we implemented a hybrid scatter correction method combined with component-based normalization, which estimates scatter components with a dual energy acquisition using a convolution subtraction-method for an estimation of trues from an upper energy window. In order to reduce statistical noise in sinograms, the implemented scheme uses the DOI compression (DOIC) method, that combines deep pairs of DOI layers into the nearest shallow pairs of DOI layers with natural detector samplings. Since the compressed data preserve the block detector configuration, as if the data are acquired using 'virtual' detectors with high {gamma}-ray stopping power, these correction methods can be applied directly to DOIC sinograms. The proposed method provides high-quality corrected images with low statistical noise, even for a multi-layer DOI-PET.

Humus layer is the main locus of secondary SO4 production in boreal forests

Science.gov (United States)

Houle, Daniel; Marty, Charles; Duchesne, Louis; Gagnon, Christian

2014-02-01

Identifying the sources of S exported from catchments and the reactivity of the large soil organic S pool is crucial to understand the mid- or long-term response of forested catchments to decreasing atmospheric S deposition and global warming. Sulfur fluxes as well as S and O isotopes of SO4 were measured in precipitation, throughfall, soil solutions and streams at two boreal forest catchments respectively dominated by black spruce (BS) and balsam fir (BF) in Quebec, Canada. Overall, δ34S-SO4 signature showed relatively small variations among various solution types. However, at both sites, δ18O-SO4 in precipitation (averages of 10.5-11.1‰) was decreased by 3.5-3.6‰ in throughfall because of the production of secondary SO4 through oxidation of SO2 deposited on the canopy. Throughfall δ18O-SO4 was decreased by a further 5.4-6.6‰ in the solution leaving the humus layer which was attributed to the production of secondary SO4 under the action of soil microorganisms through the oxidation of organic S during which the S atom acquired O from water and gaseous O2 present in the soil. A mixing equation based on known isotopic signature of each source suggested that ˜67-81% of the S-SO4 leaving the catchments had interacted with the canopy and the humus layer. The stability of δ18O-SO4 in the mineral soil solution and in the stream of both sites, suggests that SO4 does not undergo reduction-oxidation cycles after its passage through the humus layer. Despite its huge size, the organic S reservoir within the mineral soil would be largely inert. Given the chemical nature of SO4 transformation in the canopy, the humus layer would be responsible for nearly 100% of the biological production of secondary SO4 in the whole watershed at both sites. Taking into account the substantial production of dissolved organic S in the humus layer further emphasizes the crucial importance of the latter in the S cycling of boreal forests.

Open Praxis vol. 8 issue 4

Directory of Open Access Journals (Sweden)

Inés Gil-Jaurena (ed., Various authors

2016-12-01

Full Text Available This last Open Praxis issue in 2016 is an open issue that includes four research papers, two innovative practice papers and two book reviews. It also includes the list of reviewers that have collaborated in volume 8.

Transmission electron microscopy characterization of Zircaloy-4 and ZIRLO™ oxide layers

International Nuclear Information System (INIS)

Gabory, Benoit de; Motta, Arthur T.; Wang, Ke

2015-01-01

Waterside corrosion of zirconium alloy nuclear fuel cladding varies markedly from one alloy to another. In addition, for a given alloy, the corrosion rate evolves during the corrosion process, most notably when the oxide loses its stability at the oxide transition. In an effort to understand the mechanism resulting in the variations of corrosion rate observed at the oxide transition, oxide layers formed on Zircaloy-4 and ZIRLO™ in high temperature water autoclave environments, and archived before and after the transition, are characterized using transmission electron microscopy. The study characterizes and compares the oxide morphology in both alloys at different times during the corrosion process, in an effort to understand the oxide growth mechanism for these alloys. Results show that the oxide is mainly composed of monoclinic ZrO 2 , with a preponderance of columnar oxide grains which extend to the oxide/metal interface. The oxide formed right after the transition has occurred, exhibits a 150 nm-wide layer of small equiaxed grains with high tetragonal oxide fraction. This layer has a similar morphology and structure as the first oxide layer formed (observed near the oxide/water interface). A study of the oxygen-rich region near the oxide/metal interface reveals a complex structure of different phases at different stages of corrosion. The interface exhibits an intermediate layer, identified as ZrO, a discontinuous layer of “blocky” Zr 3 O grains embedded in the ZrO layer, and a suboxide layer corresponding to an oxygen saturated solid solution in the metal matrix side. The thickness of this interfacial layer decreased markedly at the transition. Hydrides are also observed in that region, with a definite orientation relationship with the matrix. The observations of the oxide/metal interface are qualitatively similar for the two alloys but quantitatively different. The incorporation of intermetallic precipitates into the oxide layer is also studied, and

Visual deprivation alters dendritic bundle architecture in layer 4 of rat visual cortex.

Science.gov (United States)

Gabbott, P L; Stewart, M G

2012-04-05

The effect of visual deprivation followed by light exposure on the tangential organisation of dendritic bundles passing through layer 4 of the rat visual cortex was studied quantitatively in the light microscope. Four groups of animals were investigated: (I) rats reared in an environment illuminated normally--group 52 dL; (II) rats reared in the dark until 21 days postnatum (DPN) and subsequently light exposed for 31 days-group 21/31; (III) rats dark reared until 52 DPN and then subsequently light exposed for 3 days--group 3 dL; and (IV) rats totally dark reared until 52 DPN--group 52 DPN. Each group contained five animals. Semithin 0.5-1-μm thick resin-embedded sections were collected from tangential sampling levels through the middle of layer 4 in area 17 and stained with Toluidine Blue. These sections were used to quantitatively analyse the composition and distribution of dendritic clusters in the tangential plane. The key result of this study indicates a significant reduction in the mean number of medium- and small-sized dendritic profiles (diameter less than 2 μm) contributing to clusters in layer 4 of groups 3 dL and 52 dD compared with group 21/31. No differences were detected in the mean number of large-sized dendritic profiles composing a bundle in these experimental groups. Moreover, the mean number of clusters and their tangential distribution in layer 4 did not vary significantly between all four groups. Finally, the clustering parameters were not significantly different between groups 21/31 and the normally reared group 52 dL. This study demonstrates, for the first time, that extended periods of dark rearing followed by light exposure can alter the morphological composition of dendritic bundles in thalamorecipient layer 4 of rat visual cortex. Because these changes occur in the primary region of thalamocortical input, they may underlie specific alterations in the processing of visual information both cortically and subcortically during periods of

Improving Efficiency of Evaporated Cu2ZnSnS4 Thin Film Solar Cells by a Thin Ag Intermediate Layer between Absorber and Back Contact

Directory of Open Access Journals (Sweden)

Hongtao Cui

2015-01-01

Full Text Available A 20 nm Ag coating on Mo back contact was adopted to improve the back contact of evaporated Cu2ZnSnS4 (CZTS solar cells. The Ag layer helped reduce the thickness of MoS2 which improves fill factor (FF significantly; additionally, it reduced secondary phases ZnS and SnS2−x, which may help carrier transport; it was also involved in the doping of the absorber layer, which compensated the intrinsic p-type doping and therefore drags down the doping level. The doping involvement may enlarge the depletion region and improve lifetime of the absorber, which led to enhancing open circuit voltage (VOC, short circuit current density (JSC, and efficiency significantly. However, it degrades the crystallinity of the material slightly.

Decoupling of Solid 4He Layers under the Superfluid Overlayer

Science.gov (United States)

Ishibashi, Kenji; Hiraide, Jo; Taniguchi, Junko; Suzuki, Masaru

2018-03-01

It has been reported that in a large oscillation amplitude, the mass decoupling of multilayer 4He films adsorbed on graphite results from the depinning of the second solid atomic layer. This decoupling suddenly vanishes below a certain low temperature TD due to the cancellation of mass decoupling by the superfluid counterflow of the the overylayer. We studied the relaxation of the depinned state at various temperatures, after reduction of oscillation amplitude below TD . It was found that above the superfluid transition temperature the mass decoupling revives with a relaxation time of several 100 s. It strongly supports that the depinned state of the second solid atomic layer remains underneath the superfluid overlayer.

Electron spectroscopy of the interface carbon layer formation on the cleavage surfaces of the layered semiconductor In4Se3 crystals

International Nuclear Information System (INIS)

Galiy, P.V.; Musyanovych, A.V.; Nenchuk, T.M.

2005-01-01

The results of the quantitative X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES) of the interface carbon layer formation on the cleavage surfaces of the layered semiconductor In 4 Se 3 crystals are presented. The carbon coating formation occurs as the result of interaction of the air and residual gases atmosphere in ultra high vacuum (UHV) Auger spectrometer chamber with atomic clean interlayer cleavage surfaces of the crystals. The kinetics and peculiarities of interfacial carbon layer formation on the cleavage surfaces of the crystals, elemental and phase composition of the interface have been studied by quantitative XPS, AES and mass-spectroscopy

Analytical determination of low velocity layer in 4-D hydrocarbon ...

African Journals Online (AJOL)

Generally, Seismic reflection surveys are done in the oil sectors to determine commercially viable hydrocarbon reservoirs but in most cases reflection records are obscured by wave behaviours in weathering layer. Hence, Up-hole refraction surveys are carried out in 3-D and 4-D prospects with a view to delineating the ...

Thickness and nanomechanical properties of protective layer formed by TiF4 varnish on enamel after erosion

Directory of Open Access Journals (Sweden)

Maria Isabel Dantas de MEDEIROS

2016-01-01

Full Text Available Abstract The layer formed by fluoride compounds on tooth surface is important to protect the underlying enamel from erosion. However, there is no investigation into the properties of protective layer formed by NaF and TiF4 varnishes on eroded enamel. This study aimed to evaluate the thickness, topography, nanohardness, and elastic modulus of the protective layer formed by NaF and TiF4 varnishes on enamel after erosion using nanoindentation and atomic force microscopy (AFM. Human enamel specimens were sorted into control, NaF, and TiF4 varnish groups (n = 10. The initial nanohardness and elastic modulus values were obtained and varnishes were applied to the enamel and submitted to erosive challenge (10 cycles: 5 s cola drink/5 s artificial saliva. Thereafter, nanohardness and elastic modulus were measured. Both topography and thickness were evaluated by AFM. The data were subjected to ANOVA, Tukey’s test and Student’s t test (α = 0.05. After erosion, TiF4 showed a thicker protective layer compared to the NaF group and nanohardness and elastic modulus values were significantly lower than those of the control group. It was not possible to measure nanohardness and elastic modulus in the NaF group due to the thin protective layer formed. AFM showed globular deposits, which completely covered the eroded surface in the TiF4 group. After erosive challenge, the protective layer formed by TiF4 varnish showed significant properties and it was thicker than the layer formed by NaF varnish.

Outdoor open thin-layer microalgal photobioreactor: potential productivity

Czech Academy of Sciences Publication Activity Database

Doucha, Jiří; Lívanský, Karel

2009-01-01

Roč. 21, č. 1 (2009), s. 111-117 ISSN 0921-8971 Institutional research plan: CEZ:AV0Z50200510 Keywords : productivity * photobioreactor * thin layer Subject RIV: EE - Microbiology, Virology Impact factor: 1.018, year: 2009

Loss and Inductance Investigations in a 4-layer Superconducting Prototype Cable Conductor

DEFF Research Database (Denmark)

Tønnesen, Ole; Olsen, Søren Krüger; Kühle (fratrådt), Anders Van Der Aa

1999-01-01

One important issue in the design and optimization of a superconducting cable conductor is the control of the current distribution between single tapes and layers. This presentation is based on a number of experiments performed on a 4-layer three meter long prototype superconducting cable conductor......-losses are measured as a function of transport current and a given current distribution and compared with the monoblock model. Recommendations for design of future cable conductor prototypes are given....

4P-NPD ultra-thin films as efficient exciton blocking layers in DBP/C70 based organic solar cells

Science.gov (United States)

Patil, Bhushan R.; Liu, Yiming; Qamar, Talha; Rubahn, Horst-Günter; Madsen, Morten

2017-09-01

Exciton blocking effects from ultra-thin layers of N,N‧-di-1-naphthalenyl-N,N‧-diphenyl [1,1‧:4‧,1″:4″,1‴-quaterphenyl]-4,4‴-diamine (4P-NPD) were investigated in small molecule-based inverted organic solar cells (OSCs) using tetraphenyldibenzoperiflanthene as the electron donor material and fullerene (C70) as the electron acceptor material. The short-circuit current density (J SC) and power conversion efficiency (PCE) of the optimized OSCs with 0.7 nm thick 4P-NPD were approximately 16% and 24% higher, respectively, compared to reference devices without exciton blocking layers (EBLs). Drift diffusion-based device modeling was conducted to model the full current density-voltage (JV) characteristics and external quantum efficiency spectrum of the OSCs, and photoluminescence measurements were conducted to investigate the exciton blocking effects with increasing thicknesses of the 4P-NPD layer. Importantly, coupled optical and electrical modeling studies of the device behaviors and exciton generation rates and densities in the active layer for different 4P-NPD layer thicknesses were conducted, in order to gain a complete understanding of the observed increase in PCE for 4P-NPD layer thicknesses up to 1 nm, and the observed decrease in PCE for layer thicknesses beyond 1 nm. This work demonstrates a route for guiding the integration of EBLs in OSC devices.

Electrodeposition of Fe{sub 3}O{sub 4} layer from solution of Fe{sub 2}(SO{sub 4}){sub 3} with addition ethylene glycol

Energy Technology Data Exchange (ETDEWEB)

Dahlan, Dahyunir, E-mail: dahyunir@yahoo.com; Asrar, Allan [Department of Physics, Andalas University, Limau Manih Padang 25163, West Sumatera (Indonesia)

2016-03-11

The electrodeposition of Fe{sub 3}O{sub 4} layer from the solution Fe{sub 2}(SO{sub 4}){sub 3} with the addition of ethylene glycol on Indium Tin Oxide (ITO) substrate has been performed. The electrodeposition was carried out using a voltage of 5 volts for 120 seconds, with and without the addition of 2% wt ethylene glycol. Significant effects of temperature on the resulting the samples is observed when they are heated at 400 °C. Structural characterization using X-ray diffraction (XRD) shows that all samples produce a layer of Fe{sub 3}O{sub 4} with particle size less than 50 nanometers. The addition of ethylene glycol and the heating of the sample causes a shrinkage in particle size. The scanning electron microscopy (SEM) characterization shows that Fe{sub 3}O{sub 4} layer resulting from the process of electrodeposition of Fe{sub 2}(SO{sub 4}){sub 3} without ethylene glycol, independent of whether the sample is heated or not, is uneven and buildup. Layer produced by the addition of ethylene glycol without heating produces spherical particles. On contrary, when the layer is heated the spherical particles transform to irregularly-shaped particles with smaller size.

Low-temperature atomic layer epitaxy of AlN ultrathin films by layer-by-layer, in-situ atomic layer annealing.

Science.gov (United States)

Shih, Huan-Yu; Lee, Wei-Hao; Kao, Wei-Chung; Chuang, Yung-Chuan; Lin, Ray-Ming; Lin, Hsin-Chih; Shiojiri, Makoto; Chen, Miin-Jang

2017-01-03

Low-temperature epitaxial growth of AlN ultrathin films was realized by atomic layer deposition (ALD) together with the layer-by-layer, in-situ atomic layer annealing (ALA), instead of a high growth temperature which is needed in conventional epitaxial growth techniques. By applying the ALA with the Ar plasma treatment in each ALD cycle, the AlN thin film was converted dramatically from the amorphous phase to a single-crystalline epitaxial layer, at a low deposition temperature of 300 °C. The energy transferred from plasma not only provides the crystallization energy but also enhances the migration of adatoms and the removal of ligands, which significantly improve the crystallinity of the epitaxial layer. The X-ray diffraction reveals that the full width at half-maximum of the AlN (0002) rocking curve is only 144 arcsec in the AlN ultrathin epilayer with a thickness of only a few tens of nm. The high-resolution transmission electron microscopy also indicates the high-quality single-crystal hexagonal phase of the AlN epitaxial layer on the sapphire substrate. The result opens a window for further extension of the ALD applications from amorphous thin films to the high-quality low-temperature atomic layer epitaxy, which can be exploited in a variety of fields and applications in the near future.

Surface layers in the 4A group metals with implanted silicon ions

International Nuclear Information System (INIS)

Kovneristyj, Yu.K.; Vavilova, V.V.; Krasnopevtsev, V.V.; Galkin, L.N.; Kudyshev, A.N.; Klechkovskaya, V.V.

1987-01-01

A study was made on the change of structure and phase composition of fine near the surface layers of 4A group metals (Hf, Zr, Ti) during ion Si implantation and successive thermal annealing at elevated temperatures. Implantation of Si + ions with 30 or 16 keV energy in Ti, Zr and Hf at room temperature results to amorphization of metal surface layer. The surface hafnium and titanium layer with implanted Si atoms due to interaction with residual atmosphere of oxygen turns during annealing at 870 K to amorphous solid solution of HfO 2m or TiO 2 with Si, preventing further metal oxidation; layers of amorphous alloy are characterized by thermal stability up to 1270 K. Oxidation of the surface amorphous layer in residual oxygen atmosphere and its crystallization in ZrO 2 take place in result of Zr annealing with implanted Si ions at temperature not exceeding 870 K. Similar phenomena are observed in the case of hafnium with implanted oxygen ions or small dose of silicon ions. Thermal stability of amorphous layers produced during ion implantation of Si in Ti, Zr and Hf corresponds to scale resistance of monolithic alloys in Ti-Si, Zr-Si and Hf-Si systems

Layered lithium manganese(0.4) nickel(0.4) cobalt(0.2) oxide(2) as cathode for lithium batteries

Science.gov (United States)

Ma, Miaomiao

The lithium ion battery occupies a dominant position in the portable battery market today. Intensive research has been carried out on every part of the battery to reduce cost, avoid environmental hazards, and improve battery performance. The commercial cathode material LiCoO2 has been partially replaced by LiNiyCo1- yO2 in the last two years, and mixed metal oxides have been introduced in the last quarter. From a resources point of view, only about 10 million tons of cobalt deposits are available from the world's minerals. However, there is about 500 times more manganese available than cobalt. Moreover, cobalt itself is not environmentally friendly. The purpose of this work is to find a promising alternative cathode material that can maintain good cycling performance, while at the same time reducing the cost and toxicity. When the cost is lowered, it is then possible to consider the larger scale use of lithium ion batteries in application such as hybrid electric vehicles (HEV). The research work presented in this thesis has focused on a specific composition of a layered lithium transition metal oxide, LiMn0.4Ni 0.4Co0.2O2 with the R3¯m structure. The presence of cobalt plays a critical role in minimizing transition metal migration to the lithium layer, and perhaps also in enhancing the electronic conductivity; however, cobalt is in limited supply and it is therefore more costly than nickel or manganese. The performance of LiMn0.4Ni0.4Co 0.2O2 was investigated and characterized utilizing various techniques an its performance compared with cobalt free LiMn0.5N i0.5O2, as well as with LiMn1/3Ni1/3Co 1/3O2, which is the most extensively studied replacement candidate for LiNiyCo1- yO2, and may be in SONY'S new hybrid cells. First, the structure and cation distribution in LiMn0.4Ni 0.4Co0.2O2 was studied by a combination of X-ray and neutron diffraction experiments. This combination study shows that about 3--5% nickel is present in the lithium layer, while manganese and

WKB solution 4×4 for electromagnetic waves in a planar magnetically anisotropic inhomogeneous layer

Science.gov (United States)

Moiseeva, Natalya Michailovna; Moiseev, Anton Vladimirovich

2018-04-01

In the paper, an oblique incidence of a plane electromagnetic wave on a planar magnetically anisotropic inhomogeneous layer is considered. We consider the case when all the components of the magnetic permeability tensor are non zero and vary with distance from the interface of media. The WKB method gives a matrix 4 × 4 solution for the projections of the electromagnetic wave fields during its propagation. The dependence of the cross-polarized components on the orientation of the anisotropic medium relative to the plane of incidence of the medium is analyzed.

Field Portable Low Temperature Porous Layer Open Tubular Cryoadsorption Headspace Sampling and Analysis Part II: Applications*

Science.gov (United States)

Harries, Megan; Bukovsky-Reyes, Santiago; Bruno, Thomas J.

2016-01-01

This paper details the sampling methods used with the field portable porous layer open tubular cryoadsorption (PLOT-cryo) approach, described in Part I of this two-part series, applied to several analytes of interest. We conducted tests with coumarin and 2,4,6-trinitrotoluene (two solutes that were used in initial development of PLOT-cryo technology), naphthalene, aviation turbine kerosene, and diesel fuel, on a variety of matrices and test beds. We demonstrated that these analytes can be easily detected and reliably identified using the portable unit for analyte collection. By leveraging efficiency-boosting temperature control and the high flow rate multiple capillary wafer, very short collection times (as low as 3 s) yielded accurate detection. For diesel fuel spiked on glass beads, we determined a method detection limit below 1 ppm. We observed greater variability among separate samples analyzed with the portable unit than previously documented in work using the laboratory-based PLOT-cryo technology. We identify three likely sources that may help explain the additional variation: the use of a compressed air source to generate suction, matrix geometry, and variability in the local vapor concentration around the sampling probe as solute depletion occurs both locally around the probe and in the test bed as a whole. This field-portable adaptation of the PLOT-cryo approach has numerous and diverse potential applications. PMID:26726934

Field portable low temperature porous layer open tubular cryoadsorption headspace sampling and analysis part II: Applications.

Science.gov (United States)

Harries, Megan; Bukovsky-Reyes, Santiago; Bruno, Thomas J

2016-01-15

This paper details the sampling methods used with the field portable porous layer open tubular cryoadsorption (PLOT-cryo) approach, described in Part I of this two-part series, applied to several analytes of interest. We conducted tests with coumarin and 2,4,6-trinitrotoluene (two solutes that were used in initial development of PLOT-cryo technology), naphthalene, aviation turbine kerosene, and diesel fuel, on a variety of matrices and test beds. We demonstrated that these analytes can be easily detected and reliably identified using the portable unit for analyte collection. By leveraging efficiency-boosting temperature control and the high flow rate multiple capillary wafer, very short collection times (as low as 3s) yielded accurate detection. For diesel fuel spiked on glass beads, we determined a method detection limit below 1 ppm. We observed greater variability among separate samples analyzed with the portable unit than previously documented in work using the laboratory-based PLOT-cryo technology. We identify three likely sources that may help explain the additional variation: the use of a compressed air source to generate suction, matrix geometry, and variability in the local vapor concentration around the sampling probe as solute depletion occurs both locally around the probe and in the test bed as a whole. This field-portable adaptation of the PLOT-cryo approach has numerous and diverse potential applications. Published by Elsevier B.V.

4onse: four times open & non-conventional technology for sensing the environment

Science.gov (United States)

Cannata, Massimiliano; Ratnayake, Rangageewa; Antonovic, Milan; Strigaro, Daniele; Cardoso, Mirko; Hoffmann, Marcus

2017-04-01

The availability of complete, quality and dense monitoring hydro-meteorological data is essential to address a number of practical issues including, but not limited to, flood-water and urban drainage management, climate change impact assessment, early warning and risk management, now-casting and weather predictions. Thanks to the recent technological advances such as Internet Of Things, Big Data and Ubiquitous Internet, non-conventional monitoring systems based on open technologies and low cost sensors may represent a great opportunity either as a complement of authoritative monitoring network or as a vital source of information wherever existing monitoring networks are in decline or completely missing. Nevertheless, scientific literature on such a kind of open and non-conventional monitoring systems is still limited and often relates to prototype engineering and testing in rather limited case studies. For this reason the 4onse project aims at integrating existing open technologies in the field of Free & Open Source Software, Open Hardware, Open Data, and Open Standards and evaluate this kind of system in a real case (about 30 stations) for a medium period of 2 years to better scientifically understand strengths, criticalities and applicabilities in terms of data quality; system durability; management costs; performances; sustainability. The ultimate objective is to contribute in non-conventional monitoring systems adoption based on four open technologies.

Synthesis, vibrational and optical properties of a new three-layered organic-inorganic perovskite (C4H9NH3)4Pb3I4Br6

International Nuclear Information System (INIS)

Dammak, T.; Elleuch, S.; Bougzhala, H.; Mlayah, A.; Chtourou, R.; Abid, Y.

2009-01-01

An organic-inorganic hybrid perovskite (C 4 H 9 NH 3 ) 4 Pb 3 I 4 Br 6 was synthesized and studied by X-ray diffraction, Raman and infrared spectroscopies, optical transmission and photoluminescence. The title compound, abbreviated (C 4 ) 4 Pb 3 I 4 Br 6 , crystallises in a periodic two-dimensional multilayer structure with P2 1 /a space group. The structure is built up from alternating inorganic and organic layers. Each inorganic layer consists of three sheets of PbX 6 (X=I, Br) octahedra. Raman and infrared spectra of the title compound were recorded in the 100-3500 and 400-4000 cm -1 frequency ranges, respectively. An assignment of the observed vibration modes is reported. Optical transmission measurements, performed on thin films of (C 4 ) 4 Pb 3 I 4 Br 6 , revealed two absorption bands at 474 and 508 nm. Photoluminescence measurements have shown a green emission peak at 519 nm.

Microsecond plasma opening switch experiments on GIT-4

Energy Technology Data Exchange (ETDEWEB)

Bystritskij, V M; Lisitsyn, I V; Sinebryukhov, A A; Sinebryukhov, V A [Russian Academy of Sciences, Tomsk (Russian Federation). Inst. of Electrophysics; Kim, A A; Kokshenev, V A; Koval` chuk, B M [Russian Academy of Sciences, Tomsk (Russian Federation). High Current Electronics Inst.

1997-12-31

The plasma opening switch (POS) operation at the current level up to 2 MA was studied at the terawatt power GIT-4 generator. The experiments are described in which the electrode diameter and the strength of the applied magnetic field were varied, and different plasma sources were used. It is shown that the high voltage / low impedance switch operation can be achieved if the linear current density at the POS cathode does not exceed 20 kA/cm. This value limits the maximum cathode diameter of the magnetically insulated transmission line. The anode diameter is limited by the requirement of no gap closure with a dense electrode plasma. The application of external magnetic field decreases the plasma density necessary for achieving a long POS conduction time operation regime. (J.U.). 1 tab., 4 refs.

Microsecond plasma opening switch experiments on GIT-4

International Nuclear Information System (INIS)

Bystritskij, V.M.; Lisitsyn, I.V.; Sinebryukhov, A.A.; Sinebryukhov, V.A.; Kim, A.A.; Kokshenev, V.A.; Koval'chuk, B.M.

1996-01-01

The plasma opening switch (POS) operation at the current level up to 2 MA was studied at the terawatt power GIT-4 generator. The experiments are described in which the electrode diameter and the strength of the applied magnetic field were varied, and different plasma sources were used. It is shown that the high voltage / low impedance switch operation can be achieved if the linear current density at the POS cathode does not exceed 20 kA/cm. This value limits the maximum cathode diameter of the magnetically insulated transmission line. The anode diameter is limited by the requirement of no gap closure with a dense electrode plasma. The application of external magnetic field decreases the plasma density necessary for achieving a long POS conduction time operation regime. (J.U.). 1 tab., 4 refs

A pillar-layered metal-organic framework as luminescent sensor for selective and reversible response of chloroform

Energy Technology Data Exchange (ETDEWEB)

Wang, Kun; Li, Shuni; Jiang, Yucheng; Hu, Mancheng; Zhai, Quan-Guo, E-mail: zhaiqg@snnu.edu.cn

2017-03-15

A new 3D metal-organic framework, namely, (Zn{sub 4}(H{sub 2}BPTC){sub 2}(HCOO){sub 4}){sub n} (SNNU-1, H{sub 4}BPTC=biphenyl-3,3',5,5'-tetracarboxylic acid, SNNU=Shaanxi Normal University) has been solvothermal synthesized. Four independent tetrahedral Zn atoms are connected by organic ligands to form a 2D Zn-H{sub 2}BPTC layer, which is further bridged by in-situ generated HCOO{sup -} to give the 3D pillar-layered framework of SNNU-1. Unique Zn and H{sub 2}BPTC all act as 4-connected nodes leading to a new 4,4,4-connected topological net with point symbol of (4·5·6{sup 2}·8{sup 2})(4·5{sup 2}·6{sup 2}·8)(5{sup 2}·6{sup 3}·7). Notably, intense blue emission band is observed for SNNU-1, which exhibits solvent-dependent effect. Compared to other common organic solvents, chloroform can specially improve the photoluminescent intensity of SNNU-1. Further repeated response and release experiments clearly showed that SNNU-1 can act as luminescent sensor for selective and reversible detection of chloroform. - Graphical abstract: Zn{sup 2+} ions are bridged by aromatic tetracarboxylate ligands and inorganic formate anions to give a microporous pillar layered open-framework, which exhibits not only strong photoluminescence but also selective and reversible luminescent sensing for chloroform. - Highlights: • Novel Zn-tetracarboxylate-formate microporous pillar layered open-framework. • New 4,4,4-connected topology and rod-packing net. • Solvent-dependent photoluminescent intensity. • Selective and reversible response for chloroform.

Improved Efficiency of Polymer Solar Cells by means of Coating Hole Transporting Layer as Double Layer Deposition

Science.gov (United States)

Chonsut, T.; Kayunkid, N.; Rahong, S.; Rangkasikorn, A.; Wirunchit, S.; Kaewprajak, A.; Kumnorkaew, P.; Nukeaw, J.

2017-09-01

Polymer solar cells is one of the promising technologies that gain tremendous attentions in the field of renewable energy. Optimization of thickness for each layer is an important factor determining the efficiency of the solar cells. In this work, the optimum thickness of Poly(3,4-ethylenedioxythione): poly(styrenesulfonate) (PEDOT:PSS), a famous polymer widely used as hole transporting layer in polymer solar cells, is determined through the analyzing of device’s photovoltaic parameters, e.g. short circuit current density (Jsc), open circuit voltage (Voc), fill factor (FF) as well as power conversion efficiency (PCE). The solar cells were prepared with multilayer of ITO/PEDOT:PSS/PCDTBT:PC70BM/TiOx/Al by rapid convective deposition. In such preparation technique, the thickness of the thin film is controlled by the deposition speed. The faster deposition speed is used, the thicker film is obtained. Furthermore, double layer deposition of PEDOT:PSS was introduced as an approach to improve solar cell efficiency. The results obviously reveal that, with the increase of PEDOT:PSS thickness, the increments of Jsc and FF play the important role to improve PCE from 3.21% to 4.03%. Interestingly, using double layer deposition of PEDOT:PSS shows the ability to enhance the performance of the solar cells to 6.12% under simulated AM 1.5G illumination of 100 mW/cm2.

The structure of carbon nanotubes formed of graphene layers L4-8, L5-7, L3-12, L4-6-12

Science.gov (United States)

Shapovalova, K. E.; Belenkov, E. A.

2017-11-01

We geometrically calculate the optimized structure of nanotubes based on the graphene layers, using the method of molecular mechanics MM+. It was found that only the nanotubes, based on the graphene layers L4-8, L5-7, L3-12, L4-6-12, have a cylindrical form. Calculations of the sublimation energy, carried out using the semi-empirical quantum-mechanic method PM3, show that energy increases with the increase of nanotube diameters.

OpenSHMEM-UCX : Evaluation of UCX for implementing OpenSHMEM Programming Model

Energy Technology Data Exchange (ETDEWEB)

Baker, Matthew B [ORNL; Gorentla Venkata, Manjunath [ORNL; Aderholdt, William Ferrol [ORNL; Shamis, Pavel [ARM Research

2016-01-01

The OpenSHMEM reference implementation was developed towards the goal of developing an open source and high-performing Open- SHMEM implementation. To achieve portability and performance across various networks, the OpenSHMEM reference implementation uses GAS- Net and UCCS for network operations. Recently, new network layers have emerged with the promise of providing high-performance, scalabil- ity, and portability for HPC applications. In this paper, we implement the OpenSHMEM reference implementation to use the UCX framework for network operations. Then, we evaluate its performance and scalabil- ity on Cray XK systems to understand UCX s suitability for developing the OpenSHMEM programming model. Further, we develop a bench- mark called SHOMS for evaluating the OpenSHMEM implementation. Our experimental results show that OpenSHMEM-UCX outperforms the vendor supplied OpenSHMEM implementation in most cases on the Cray XK system by up to 40% with respect to message rate and up to 70% for the execution of application kernels.

Preparation, Characterization, and Structure of Two Layered Molybdenum(VI) Phosphates: KMo(H 2O)O 2PO 4 and NH 4Mo(H 2O)O 2PO 4

Science.gov (United States)

Millini, Roberto; Carati, Angela

1995-08-01

New layered Mo(VI) compounds, KMo(H 2O)O 2PO 4 (I) and NH 4Mo(H 2O)O 2PO 4 (II), were synthesized hydrothermally and their structures were determined from single-crystal X-ray analysis. Compounds (I) and (II) are isostructural and crystallize in the monoclinic P2 1/ n space group with a = 12.353(3), b = 8.623(2), c = 5.841(1) Å, β = 102.78(1)°, V = 606.8(2) Å 3, Z = 4, and R = 0.027 ( Rw = 0.030) for compound (I) and a = 12.435(3), b = 8.761(2), c = 6.015(1), β = 103.45(1)°, V = 637.3(2) Å 3, Z = 4, and R = 0.040 ( Rw = 0.041) for compound (II). The structure consists of layers built up of eight- and four-membered rings resulting from the alternation of corner-sharing [MoO 6] octahedra and [PO 4] tetrahedra. The layers stack along the (1¯01) direction by intercalating K and NH 4 ions.

The thermal neutron detection using 4H-SiC detectors with 6LiF conversion layer

International Nuclear Information System (INIS)

Zatko, B.; Bohacek, P.; Sekacova, M.; Arbet, J.; Sagatova, A.; Necas, V.

2016-01-01

In this paper we have examined 4H-SiC detector using a thermal neutron source and studied its detection properties. The detector was exposed to neutrons generated by 238 Pu-Be radiation source. The detection properties of 4H-SiC detectors were evaluated considering the use of the 6 LiF conversion. We prepared 4H-SiC Schottky contact detectors based on high-quality of epitaxial layer. The current-voltage characteristic show operating region between 100 V and 400 V. The detector was connected to the spectrometric set-up and used for detection of alpha particles from 241 Am. Following the 6 LiF conversion layer was applied on the Schottky contact of detector and the detection of thermal neutrons was performed. We are able to resolve alpha particles and tritons which are products of nuclear reaction between thermal neutrons and conversion layer. Also bare detector was used for neutron detection to clearly show significant influence of the used conversion layer.(authors)

Open software architecture for east articulated maintenance arm

International Nuclear Information System (INIS)

Wu, Jing; Wu, Huapeng; Song, Yuntao; Li, Ming; Yang, Yang; Alcina, Daniel A.M.

2016-01-01

Highlights: • A software requirement of serial-articulated robot for EAST assembly and maintains is presented. • A open software architecture of the robot is developed. • A component-based model distribution system with real-time communication of the robot is constructed. - Abstract: For the inside inspection and the maintenance of vacuum vessel in the EAST, an articulated maintenance arm is developed. In this article, an open software architecture developed for the EAST articulated maintenance arm (EAMA) is described, which offers a robust and proper performance and easy-going experience based on standard open robotic platform OROCOS. The paper presents a component-based model software architecture using multi-layer structure: end layer, up layer, middle, and down layer. In the end layer the components are defined off-line in the task planner manner. The components in up layer complete the function of trajectory plan. The CORBA, as a communication framework, is adopted to exchange the data between the distributed components. The contributors use Real-Time Workshop from the MATLAB/Simulink to generate the components in the middle layer. Real-time Toolkit guarantees control applications running in the hard real-time mode. Ethernets and the CAN bus are used for data transfer in the down layer, where the components implement the hardware functions. The distributed architecture of control system associates each processing node with each joint, which is mapped to a component with all functioning features of the framework.

Open software architecture for east articulated maintenance arm

Energy Technology Data Exchange (ETDEWEB)

Wu, Jing, E-mail: wujing@ipp.ac.cn [Institute of Plasma Physics Chinese Academy of Sciences, 350 Shushanhu Rd Hefei Anhui (China); Lappeenranta University of Technology, Skinnarilankatu 34 Lappeenranta (Finland); Wu, Huapeng [Lappeenranta University of Technology, Skinnarilankatu 34 Lappeenranta (Finland); Song, Yuntao [Institute of Plasma Physics Chinese Academy of Sciences, 350 Shushanhu Rd Hefei Anhui (China); Li, Ming [Lappeenranta University of Technology, Skinnarilankatu 34 Lappeenranta (Finland); Yang, Yang [Institute of Plasma Physics Chinese Academy of Sciences, 350 Shushanhu Rd Hefei Anhui (China); Alcina, Daniel A.M. [Lappeenranta University of Technology, Skinnarilankatu 34 Lappeenranta (Finland)

2016-11-01

Highlights: • A software requirement of serial-articulated robot for EAST assembly and maintains is presented. • A open software architecture of the robot is developed. • A component-based model distribution system with real-time communication of the robot is constructed. - Abstract: For the inside inspection and the maintenance of vacuum vessel in the EAST, an articulated maintenance arm is developed. In this article, an open software architecture developed for the EAST articulated maintenance arm (EAMA) is described, which offers a robust and proper performance and easy-going experience based on standard open robotic platform OROCOS. The paper presents a component-based model software architecture using multi-layer structure: end layer, up layer, middle, and down layer. In the end layer the components are defined off-line in the task planner manner. The components in up layer complete the function of trajectory plan. The CORBA, as a communication framework, is adopted to exchange the data between the distributed components. The contributors use Real-Time Workshop from the MATLAB/Simulink to generate the components in the middle layer. Real-time Toolkit guarantees control applications running in the hard real-time mode. Ethernets and the CAN bus are used for data transfer in the down layer, where the components implement the hardware functions. The distributed architecture of control system associates each processing node with each joint, which is mapped to a component with all functioning features of the framework.

A comparison of two IPv4/IPv6 transition mechanisms - OpenVPN and IVI

Science.gov (United States)

Vu, Cong Tuan; Tran, Quang Anh; Jiang, Frank

2012-09-01

This document presents a comparison of two IPv4/IPv6 transition mechanisms. They are OpenVPN and IVI. Meanwhile OpenVPN is based on tunneling technology, IVI is a stateless IPv4/IPv6 translation technique which is developed by China Education and Research Network (CERNET). This research focus on the quantitative and qualitative comparison of these two main mechanisms; how they are applied in practical situation by the Internet Service Providers, as well as their advantages and drawbacks.

Development of a Buried Layer Platform at the OMEGA Laser to Study Open L-Shell Spectra from Coronal (non-LTE) Plasmas

Science.gov (United States)

Marley, Edward; Jarrot, Charlie; Schneider, Marilyn; Kemp, Elijah; Foord, Mark; Heeter, Robert; Liedahl, Duane; Widmann, Klause; Mauche, Christopher; Brown, Greg; Emig, James

2017-10-01

A buried layer platform is being developed at the OMEGA laser to study the open L-shell spectra of coronal (non LTE) plasmas (ne few 1021/cm3, Te 0.8-1.2 keV) of mid Z materials. Studies have been done using a 250 μm diameter dot composed of a layer of 1200 Å thick Zn between two 600 Å thick layers of Ti, in the center of a 1000 μm diameter, 13 μm thick beryllium tamper. Lasers heat the target from both sides for up to 3 ns. The size of the microdot vs time was measured with x-ray imaging (face-on and side-on). The radiant x-ray power was measured with a low-resolution absolutely calibrated x-ray spectrometer (DANTE). The temperature was measured from the Ti helium-beta complex. The use of this platform for the verification of atomic models is discussed. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

Lamina cribrosa position and Bruch's membrane opening differences between anterior ischemic optic neuropathy and open-angle glaucoma.

Science.gov (United States)

Rebolleda, Gema; Pérez-Sarriegui, Ane; Díez-Álvarez, Laura; De Juan, Victoria; Muñoz-Negrete, Francisco J

2018-06-01

To compare the optic nerve head morphology among primary open-angle glaucoma, non-arteritic anterior ischemic optic neuropathy eyes, their fellow healthy eyes and control eyes, using spectral-domain optical coherence tomography with enhanced depth imaging. Observational cross-sectional study including 88 eyes of 68 patients. In this study, 23 non-arteritic anterior ischemic optic neuropathy eyes, 17 fellow unaffected eyes, 25 primary open-angle glaucoma eyes, and 23 age-matched control eyes were included. Peripapillary retinal nerve fiber layer thickness and optic disk area were evaluated. Bruch's membrane opening diameter, optic cup depth, anterior lamina cribrosa depth, and prelaminar tissue thickness were assessed. Non-arteritic anterior ischemic optic neuropathy and primary open-angle glaucoma eyes had similar visual field mean deviation and peripapillary retinal nerve fiber layer thickness (P = 0.6 and P = 0.56, respectively). Bruch's membrane opening diameter was significantly larger in primary open-angle glaucoma eyes than in control eyes (P = 0.02). Lamina cribrosa and disk cup were deeper in eyes with primary open-angle glaucoma than both control and non-arteritic anterior ischemic optic neuropathy eyes (P open-angle glaucoma eyes than in non-arteritic anterior ischemic optic neuropathy eyes (P opening diameter was found in primary open-angle glaucoma eyes compared with control eyes. This issue has clinical implications because Bruch's membrane opening has been considered a stable reference for disk-related measures.

Influence of the heat treatment condition of alloy AlCu4Mg1 on the microstructure and properties of anodic oxide layers

Science.gov (United States)

Morgenstern, R.; Dietrich, D.; Sieber, M.; Lampke, T.

2017-03-01

Due to their outstanding specific mechanical properties, high-strength, age-hardenable aluminum alloys offer a high potential for lightweight security-related applications. However, the use of copper-alloyed aluminum is limited because of their susceptibility to selective corrosion and their low wear resistance. These restrictions can be overcome and new applications can be opened up by the generation of protective anodic aluminum oxide layers. In contrast to the anodic oxidation of unalloyed aluminum, oxide layers produced on copper-rich alloys exhibit a significantly more complex pore structure. It is the aim of the investigation to identify the influence of microstructural parameters such as size and distribution of the strengthening precipitations on the coating microstructure. The aluminum alloy EN AW-2024 (AlCu4Mg1) in different heat treatment conditions serves as substrate material. The influence of the strengthening precipitations’ size and distribution on the development of the pore structure is investigated by the use of high-resolution scanning electron microscopy. Integral coating properties are characterized by non-destructive and light-microscopic thickness measurements and instrumented indentation tests.

Stimulated transformation in nano-layered composites with Se0.6Te0.4

International Nuclear Information System (INIS)

Malyovanik, M.; Shipljak, M.; Cheresnya, V.; Ivan, I.; Csik, A.; Kokenyesi, S.; Debrecen Univ.

2005-01-01

Complete text of publication follows. The main types of the photo-induced structural transformations (PST) in chalcogenide glasses and amorphous layers can be systematized as i) structural transformations within amorphous phase, ii) photo-induced crystallization or amorphyzation, iii) photo-induced mass transport. These main known types of PST can be further detailed, for example concerning photo-induced anisotropy, photo- bleaching, etc., and are widely investigated. But the fundamentals of these effects even in the most known compositions like AsSe, As 2 S 3 are not clear, especially for the nanostructures, where the possible cluster formation, size restrictions and interface conditions may essentially influence the parameters of the material. Furthermore, the basic applied problem related to the PST consists of the possibility of digital or analog optical information storage, phase change memory, fabrication of elements for optics and photonics. These applications require determined spectral and temperature range of functioning, increased sensitivity, transformation rates and stability of the memory at the same time. The realization of such requirements can be expected in nanosized objects made of chalcogenides due to the suitable change of thermodynamical parameters, conductivity, optical and other characteristics. The establishment of correlations between the compositional modulation at nanoscale-dimensions (3-10 nm) in Se 0.6 Te 0.4 and the changes of the optical and electrical parameters as well as the possible improvement of optical recording process in comparison with homogeneous Se 0.6 Te 0.4 films were the aims of the present work. Two types of nano-multilayers, namely Se 0.6 Te 0.4 /SiO x and Se 0.6 Te 0.4 /As 2 S 3 were investigated with respect to the thermo- or light-stimulated structural transformations, since they strongly di r by the possibility of intermixing or crystallization in a steady-state process of heating or laser illumination. Photo

MoO3 trapping layers with CF4 plasma treatment in flash memory applications

International Nuclear Information System (INIS)

Kao, Chuyan Haur; Chen, Hsiang; Chen, Su-Zhien; Chen, Chian Yu; Lo, Kuang-Yu; Lin, Chun Han

2014-01-01

Highlights: • MoO 3 -based flash memories have been fabricated. • CF4 plasma treatment could enhance good memory performance. • Material analyses confirm that plasma treatment eliminated defects. • Fluorine atoms might fix the dangling bonds. - Abstract: In this research, we used MoO 3 with CF 4 plasma treatment as charge trapping layer in metal-oxide-high-k -oxide-Si-type memory. We analyzed material properties and electrical characteristics with multiple analyses. The plasma treatment could increase the trapping density, reduce the leakage current, expand band gap, and passivate the defect to enhance the memory performance. The MoO 3 charge trapping layer memory with suitable CF 4 plasma treatment is promising for future nonvolatile memory applications

The comparison of phosphate-titanate-silicate layers on the titanium and Ti6Al4V alloy base

Science.gov (United States)

Rokita, M.

2011-08-01

The studied layers were composed of two parts: titanate-silicate underlayer for better adhesion and titanate-phosphate-silicate layers for potential bioparameters. The layers with different amounts of hydroxyapatite were deposited on titanium and Ti6Al4V alloy substrates using dipping sol-gel method and electrophoresis. The selection of sol/suspension composition, deposition time and heat treatment conditions have the decisive influence on the layers parameters. The obtained layers should be very thin and almost amorphous. The specific nature of ceramic layers on the metal substrates excludes the use of some measurements methods or makes it difficult to interpret the measurement results. All the obtained samples were compared using XRD analysis data (GID technique), SEM with EDX measurements and FTIR spectroscopy (transmission and reflection techniques) before and after soaking in simulated body fluid. FTIR spectroscopy with mathematical treatment of the spectra (BIO-RAD Win-IR program, Arithmetic-subtract function) was used to detect the increase or decrease of any phosphate phases during SBF soaking. Based on the FTIR results the processes of hydroxyapatite (HAp) growth or layer dissolution were estimated. The layers deposited on titanium substrate are more crystalline then the ones deposited on Ti6Al4V. During SBF soaking process the growth of small amount of microcrystalline carbonate hydroxyapatite was observed on titanium substrate. The layer on Ti6Al4V base contained amorphous carbonate apatite. During heating treatment above about 870-920 K this apatite transforms into carbonate hydroxyapatite. The Ti6Al4V substrate seems to be more advantageous in context of potentially bioactive materials obtaining.

Barrier layer arrangement for conductive layers on silicon substrates

International Nuclear Information System (INIS)

Hung, L.S.; Agostinelli, J.A.

1990-01-01

This patent describes a circuit element comprised of a silicon substrate and a conductive layer located on the substrate. It is characterized in that the conductive layer consists essentially of a rare earth alkaline earth copper oxide and a barrier layer triad is interposed between the silicon substrate and the conductive layer comprised of a first triad layer located adjacent the silicon substrate consisting essentially of silica, a third triad layer remote from the silicon substrate consisting essentially of a least one Group 4 heavy metal oxide, and a second triad layer interposed between the first and third triad layers consisting essentially of a mixture of silica and at lease one Group 4 heavy metal oxide

OSS4EVA: Using Open-Source Tools to Fulfill Digital Preservation Requirements

Directory of Open Access Journals (Sweden)

Heidi Dowding

2016-10-01

Full Text Available This paper builds on the findings of a workshop held at the 2015 International Conference on Digital Preservation (iPRES, entitled, “Using Open-Source Tools to Fulfill Digital Preservation Requirements” (OSS4PRES hereafter. This day-long workshop brought together participants from across the library and archives community, including practitioners, proprietary vendors, and representatives from open-source projects. The resulting conversations were surprisingly revealing: while OSS’ significance within the preservation landscape was made clear, participants noted that there are a number of roadblocks that discourage or altogether prevent its use in many organizations. Overcoming these challenges will be necessary to further widespread, sustainable OSS adoption within the digital preservation community. This article will mine the rich discussions that took place at OSS4PRES to (1 summarize the workshop’s key themes and major points of debate, (2 provide a comprehensive analysis of the opportunities, gaps, and challenges that using OSS entails at a philosophical, institutional, and individual level, and (3 offer a tangible set of recommendations for future work designed to broaden community engagement and enhance the sustainability of open source initiatives, drawing on both participants’ experience as well as additional research.

Incorporating an Electrode Modification Layer with a Vertical Phase Separated Photoactive Layer for Efficient and Stable Inverted Nonfullerene Polymer Solar Cells.

Science.gov (United States)

Shi, Zhenzhen; Liu, Hao; Wang, Yaping; Li, Jinyan; Bai, Yiming; Wang, Fuzhi; Bian, Xingming; Hayat, Tasawar; Alsaedi, Ahmed; Tan, Zhan'ao

2017-12-20

For bulk heterojunction polymer solar cells (PSCs), the donors and acceptors featuring specific phase separation and concentration distribution within the electron donor/acceptor blends crucially affect the exciton dissociation and charge transportation. Herein, efficient and stable nonfullerene inverted PSCs incorporating a phase separated photoactive layer and a titanium chelate electrode modification layer are demonstrated. Water contact angle (WCA), scanning kelvin probe microscopy (SKPM), and atomic force microscopy (AFM) techniques are implemented to characterize the morphology of photoactive layers. Compared with the control conventional device, the short-circuit current density (J sc ) is enhanced from 14.74 to 17.45 mAcm -2 . The power conversion efficiency (PCE) for the inverted PSCs with a titanium (diisopropoxide)-bis-(2,4-pentanedionate) (TIPD) layer increases from 9.67% to 11.69% benefiting from the declined exciton recombination and fairly enhanced charge transportation. Furthermore, the nonencapsulated inverted device with a TIPD layer demonstrates the best long-term stability, 85% of initial PCE remaining and an almost undecayed open-circuit voltage (V oc ) after 1440 h. Our results reveal that the titanium chelate is an excellent electrode modification layer to incorporate with a vertical phase separated photoactive layer for producing high-efficiency and high-stability inverted nonfullerene PSCs.

MAC-Layer Active Dropping for Real-Time Video Streaming in 4G Access Networks

KAUST Repository

She, James

2010-12-01

This paper introduces a MAC-layer active dropping scheme to achieve effective resource utilization, which can satisfy the application-layer delay for real-time video streaming in time division multiple access based 4G broadband wireless access networks. When a video frame is not likely to be reconstructed within the application-layer delay bound at a receiver for the minimum decoding requirement, the MAC-layer protocol data units of such video frame will be proactively dropped before the transmission. An analytical model is developed to evaluate how confident a video frame can be delivered within its application-layer delay bound by jointly considering the effects of time-varying wireless channel, minimum decoding requirement of each video frame, data retransmission, and playback buffer. Extensive simulations with video traces are conducted to prove the effectiveness of the proposed scheme. When compared to conventional cross-layer schemes using prioritized-transmission/retransmission, the proposed scheme is practically implementable for more effective resource utilization, avoiding delay propagation, and achieving better video qualities under certain conditions.

Significantly improved efficiency of organic solar cells incorporating Co3O4 NPs in the active layer

Science.gov (United States)

Yousaf, S. Amber; Ikram, M.; Ali, S.

2018-03-01

Effect of various concentrations of fabricated cobalt oxide (Co3O4) nanoparticles (NPs) in the active layer of different donors and acceptors based hybrid organic bulk heterojunction-BHJ devices were investigated using inverted architecture. The organic active layer comprising different donors P3HT (poly(3-hexylthiophene-2,5-diyl) and PTB7 (Poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b] thiophenediyl

Fluorocarbon based atomic layer etching of Si_3N_4 and etching selectivity of SiO_2 over Si_3N_4

International Nuclear Information System (INIS)

Li, Chen; Metzler, Dominik; Oehrlein, Gottlieb S.; Lai, Chiukin Steven; Hudson, Eric A.

2016-01-01

Angstrom-level plasma etching precision is required for semiconductor manufacturing of sub-10 nm critical dimension features. Atomic layer etching (ALE), achieved by a series of self-limited cycles, can precisely control etching depths by limiting the amount of chemical reactant available at the surface. Recently, SiO_2 ALE has been achieved by deposition of a thin (several Angstroms) reactive fluorocarbon (FC) layer on the material surface using controlled FC precursor flow and subsequent low energy Ar"+ ion bombardment in a cyclic fashion. Low energy ion bombardment is used to remove the FC layer along with a limited amount of SiO_2 from the surface. In the present article, the authors describe controlled etching of Si_3N_4 and SiO_2 layers of one to several Angstroms using this cyclic ALE approach. Si_3N_4 etching and etching selectivity of SiO_2 over Si_3N_4 were studied and evaluated with regard to the dependence on maximum ion energy, etching step length (ESL), FC surface coverage, and precursor selection. Surface chemistries of Si_3N_4 were investigated by x-ray photoelectron spectroscopy (XPS) after vacuum transfer at each stage of the ALE process. Since Si_3N_4 has a lower physical sputtering energy threshold than SiO_2, Si_3N_4 physical sputtering can take place after removal of chemical etchant at the end of each cycle for relatively high ion energies. Si_3N_4 to SiO_2 ALE etching selectivity was observed for these FC depleted conditions. By optimization of the ALE process parameters, e.g., low ion energies, short ESLs, and/or high FC film deposition per cycle, highly selective SiO_2 to Si_3N_4 etching can be achieved for FC accumulation conditions, where FC can be selectively accumulated on Si_3N_4 surfaces. This highly selective etching is explained by a lower carbon consumption of Si_3N_4 as compared to SiO_2. The comparison of C_4F_8 and CHF_3 only showed a difference in etching selectivity for FC depleted conditions. For FC accumulation conditions

Hydrothermal synthesis and characteristics of 3-D hydrated bismuth oxalate coordination polymers with open-channel structure

International Nuclear Information System (INIS)

Chen Xinxiang; Cao Yanning; Zhang Hanhui; Chen Yiping; Chen Xuehuan; Chai Xiaochuan

2008-01-01

Two new 3-D porous bismuth coordination polymers, (C 5 NH 6 ) 2 [Bi 2 (H 2 O) 2 (C 2 O 4 ) 4 ].2H 2 O 1 and (NH 4 )[Bi(C 2 O 4 ) 2 ].3H 2 O 2, have been hydrothermally synthesized and characterized by single-crystal X-ray diffraction. Compound 1 crystallizes in the monoclinic symmetry, P2 1 /c space group with a=10.378(2) A, b=17.285(3) A, c=16.563(5) A, α=90 deg., β=119.66(2) deg., γ=90 deg., V=2581.8(10) A 3 , Z=4, R 1 =0.0355 and wR 2 =0.0658 for unique 4713 reflections I >2σ(I). Compound 2 crystallizes in the tetragonal symmetry, I4 1 /amd space group with a=11.7026(17) A, b=11.7026(17) A, c=9.2233(18) A, α=90 deg., β=90 deg., γ=90 deg., V=1263.1(4) A 3 , Z=32, R 1 =0.0208 and wR 2 =0.0518 for unique 359 reflections I> 2σ(I). Compounds 1 and 2 are 3-D open-framework structures with a 6 6 uniform net, which consist of honeycomb-like layers connected to each other by oxalate units. While different guest molecules fill in their cavities of honeycomb-like layers, study of ultrasonic treatment on 2 indicates the replacement of NH 4 + by K + on potassium ion exchange. Thermogravimetric analysis indicates that the open-channel frameworks are thermally stable up to 200 deg. C, and other characterizations are also described by elemental analysis, IR and ultraviolet-visible diffuse reflectionintegral spectrum (UV-Vis DRIS). - Graphical abstract: Two novel 3-D extended porous coordination polymers have been synthesized by hydrothermal method. Both compounds are 3-D open-framework structures with a 6 6 uniform net, which consist of honeycomb-like layers connected to each other by oxalate units. While different guest molecules fill in their cavities of honeycomb-like layers. Study of ultrasonic treatment on 2 indicates the replacement of NH 4 + by K + on potassium ion exchange

Open-source tool for automatic import of coded surveying data to multiple vector layers in GIS environment

Directory of Open Access Journals (Sweden)

Eva Stopková

2016-12-01

Full Text Available This paper deals with a tool that enables import of the coded data in a singletext file to more than one vector layers (including attribute tables, together withautomatic drawing of line and polygon objects and with optional conversion toCAD. Python script v.in.survey is available as an add-on for open-source softwareGRASS GIS (GRASS Development Team. The paper describes a case study basedon surveying at the archaeological mission at Tell-el Retaba (Egypt. Advantagesof the tool (e.g. significant optimization of surveying work and its limits (demandson keeping conventions for the points’ names coding are discussed here as well.Possibilities of future development are suggested (e.g. generalization of points’names coding or more complex attribute table creation.

Superfluid Boundary Layer.

Science.gov (United States)

Stagg, G W; Parker, N G; Barenghi, C F

2017-03-31

We model the superfluid flow of liquid helium over the rough surface of a wire (used to experimentally generate turbulence) profiled by atomic force microscopy. Numerical simulations of the Gross-Pitaevskii equation reveal that the sharpest features in the surface induce vortex nucleation both intrinsically (due to the raised local fluid velocity) and extrinsically (providing pinning sites to vortex lines aligned with the flow). Vortex interactions and reconnections contribute to form a dense turbulent layer of vortices with a nonclassical average velocity profile which continually sheds small vortex rings into the bulk. We characterize this layer for various imposed flows. As boundary layers conventionally arise from viscous forces, this result opens up new insight into the nature of superflows.

Open system LANs and their global interconnection electronics and communications reference series

CERN Document Server

Houldsworth, Jack; Caves, Keith; Mazda, FF

2014-01-01

Open System LANs and Their Global Interconnection focuses on the OSI layer 1 to 4 standards (the OSI bearer service) and also introduces TCP/IP and some of the proprietary PC Local Area Network (LAN) standards.The publication first provides an introduction to Local Area Networks (LANs) and Wide Area Networks (WANs), Open Systems Interconnection (OSI), and LAN standards. Discussions focus on MAC bridging, token bus, slotted ring, MAC constraints and design considerations, OSI functional standards, OSI model, value of the transport model, benefits and origins of OSI, and significance of the tran

Magnetic properties of layered superconductors

International Nuclear Information System (INIS)

Mansky, P.A.

1993-01-01

The organic superconductors (BEDT-TTF) 2 Cu(SNC) 2 and (TMTSF) 2 ClO 4 , with T c = 10K and 1.2K, have layered and highly anisotropic crystal structures. This thesis describes AC magnetic susceptibility measurements on these materials which illustrate the consequences of the discrete layered structure for the magnetic properties of the superconducting state. A DC magnetic field applied parallel to the layers of either material causes the rapid suppression of the AC screening response, and this indicates that the pinning restoring force for vortex motion parallel to the layers is anomalously weak in this orientation. This is believed to be due to the small size of the interlayer coherence length relative to the layer spacing. A simple estimate based on the energy and length scales relevant to Josephson coupled layers gives the correct order of magnitude for the pinning force. Pinning for vortices oriented perpendicular to the layers is larger by a factor of 500 for BEDT and 25 for TMTSF. When the DC field is applied at an angle to the layers, the initial suppression of the susceptibility is identical to that for a field parallel to the layers; when the field component normal to the layers exceeds a threshold, a sharp recovery of screening occurs. These observations indicate that the field initially enters the sample only in the direction parallel to the layers. The recovery of screening signals field penetration in the perpendicular direction at higher field strength, and is due to the onset of pinning by in-plane vortex cores. This magnetic open-quotes lock-inclose quotes effect is a qualitatively new behavior and is a direct consequence of weak interlayer coupling. The London penetration depth associated with interlayer currents is found to be on the order of hundreds of microns, comparable to that of a Josephson junction, and two to three orders of magnitude larger than for conventional superconductors

The Impact of Lens Opacity on SD-OCT Retinal Nerve Fiber Layer and Bruch's Membrane Opening Measurements Using the Anatomical Positioning System (APS).

Science.gov (United States)

Mauschitz, Matthias M; Roth, Felix; Holz, Frank G; Breteler, Monique M B; Finger, Robert P

2017-05-01

To evaluate the impact of lens opacity on retinal nerve fiber layer thickness (RNFLT) and Bruch's membrane opening (BMO) measurements. Fifty-nine randomly selected patients without any other relevant ocular pathology undergoing elective routine cataract surgery in two specialized eye clinics were enrolled. RNFLT, BMO area, and BMO minimum rim width (BMO-MRW) were assessed with the Heidelberg Engineering Spectralis OCT using the anatomical positioning system (APS) prior to and 1 day after cataract surgery using a ring scan at different eccentricities of the disc (3.5, 4.1 and 4.7 mm). Lens opacity was quantified using densitometry based on Scheimpflug images (Oculus Pentacam AXL). RNFLT, BMO area, and BMO-MRW were virtually identical before and following removal of the cataractous lens. This held when assessed overall, within the six sectors for the 3.5-mm scan, or at any other eccentricity. Baseline RNFLT was not associated with lens opacity. Using the APS, RNFLT remained unchanged following cataract surgery, contrary to results reported by previous studies. Our results imply that the APS may have contributed to more precise spectral-domain optical coherence measurements, minimizing the influence of cataract on RNFLT and BMO assessments in our cohort.

Synthesis and controlled release properties of 2,4-dichlorophenoxy acetate–zinc layered hydroxide nanohybrid

International Nuclear Information System (INIS)

Bashi, Abbas M.; Hussein, Mohd Zobir; Zainal, Zulkarnain; Tichit, Didier

2013-01-01

Direct reaction of ZnO with 2,4-dichlorophenoxyacetic acid (24D) solutions of different concentrations allows obtaining new organic–inorganic nanohybrid materials formed by intercalation of 24D into interlayers of zinc layered hydroxide (ZLH). XRD patterns show a progressive evolution of the structure as 24D concentration increases. The nanohybrid obtained at higher 24D concentration (24D–ZLH(0.4)) reveals a well ordered layered structure with two different basal spacings at 25.2 Å and 24 Å. The FTIR spectrum showing the vibrations bands of the functional groups of 24D and of the ZLH confirms the intercalation. SEM images are in agreement with the structural evolution observed by XRD and reveal the ribbon morphology of the nanohybrids. The release studies of 24D showed a rapid release of 94% for the first 100 min governed by the pseudo-second order kinetic model. - Graphical abstract: The phenomenon indicates that the optical energy gap is enlarged with the increase of molar concentrations in 2,4-dichlorophenoxy acetate anion content into ZnO to create a ZLH–24D nanohybrid. - Highlights: • Nanohybrid was synthesized from 2,4-dichlorophenoxy acetate with-Zinc LHD, using wet chemistry. • Characterized using SEM, TEM, EDX, FTIR, XRD and TGA. • Ribbon-shaped 24D–Zn-layered hydroxide nanoparticles with (003) diffractions of 2.5 nm phase were synthesized

Si-Imidazole-HSO4 Functionalized Magnetic Fe3O4 Nanoparticles as an Efficient and Reusable Catalyst for the Regioselective Ring Opening of Epoxides in Water

Directory of Open Access Journals (Sweden)

Eshagh Rezaee Nezhad

2016-01-01

Full Text Available An efficient and simple method for the preparation of Si-Imidazole-HSO4 functionalized magnetic Fe3O4 nanoparticles (Si-Im-HSO4 MNPs and used as an efficient and reusable magnetic catalysts for the regioselective ring opening of epoxides under green conditions in water. This catalyst was used for the ring opening of epoxide corresponding to the thiocyanohydrins and azidohydrines. Compared to the classical ring opening of epoxides, this new method consistently has the advantage of excellent yields, short reaction times, and methodological simplicity.

Information Security of PHY Layer in Wireless Networks

Directory of Open Access Journals (Sweden)

Weidong Fang

2016-01-01

Full Text Available Since the characteristics of wireless channel are open and broadcasting, wireless networks are very vulnerable to be attacked via eavesdropping, jamming, and interference. As traditional secure technologies are not suitable for PHY layer of wireless networks, physical-layer security issues become a focus of attention. In this paper, we firstly identify and summarize the threats and vulnerabilities in PHY layer of wireless networks. Then, we give a holistic overview of PHY layer secure schemes, which are divided into three categories: spatial domain-based, time domain-based, and frequency domain-based. Along the way, we analyze the pros and cons of current secure technologies in each category. In addition, we also conclude the techniques and methods used in these categories and point out the open research issues and directions in this area.

Randomized trial of four-layer and two-layer bandage systems in the management of chronic venous ulceration.

Science.gov (United States)

Moffatt, Christine J; McCullagh, Lynn; O'Connor, Theresa; Doherty, Debra C; Hourican, Catherine; Stevens, Julie; Mole, Trevor; Franks, Peter J

2003-01-01

To compare a four-layer bandage system with a two-layer system in the management of chronic venous leg ulceration, a prospective randomized open parallel groups trial was undertaken. In total, 112 patients newly presenting to leg ulcer services with chronic leg ulceration, screened to exclude the presence of arterial disease (ankle brachial pressure index ulceration other than venous disease, were entered into the trial. Patients were randomized to receive either four-layer (Profore) or two-layer (Surepress) high-compression elastic bandage systems. In all, 109 out of 112 patients had at least one follow-up. After 24 weeks, 50 out of 57 (88%) patients randomized to the four-layer bandage system with follow-up had ulcer closure (full epithelialization) compared with 40 out of 52 (77%) on the two-layer bandage, hazard ratio = 1.18 (95% confidence interval 0.69-2.02), p = 0.55. After 12 weeks, 40 out of 57 (70%) patients randomized to the four-layer bandage system with follow-up had ulcer closure compared with 30 out of 52 (58%) on the two-layer bandage, odds ratio = 4.23 (95% confidence interval 1.29-13.86), p = 0.02. Withdrawal rates were significantly greater on the two-layer bandage (30 out of 54; 56%) compared with the four-layer bandage system (8 out of 58; 14%), p bandaging system (15 out of 54; 28%) compared with four-layer bandaging (5 out of 54; 9%), p = 0.01. The higher mean cost of treatment in the two-layer bandaging system arm over 24 weeks ($1374 [ pound 916] vs. $1314 [ pound 876]) was explained by the increased mean number of bandage changes (1.5 vs. 1.1 per week) with the two-layer system. In conclusion, the four-layer bandage offers advantages over the two-layer bandage in terms of reduced withdrawal from treatment, fewer adverse incidents, and lower treatment cost.

Developments in the Aerosol Layer Height Retrieval Algorithm for the Copernicus Sentinel-4/UVN Instrument

Science.gov (United States)

Nanda, Swadhin; Sanders, Abram; Veefkind, Pepijn

2016-04-01

The Sentinel-4 mission is a part of the European Commission's Copernicus programme, the goal of which is to provide geo-information to manage environmental assets, and to observe, understand and mitigate the effects of the changing climate. The Sentinel-4/UVN instrument design is motivated by the need to monitor trace gas concentrations and aerosols in the atmosphere from a geostationary orbit. The on-board instrument is a high resolution UV-VIS-NIR (UVN) spectrometer system that provides hourly radiance measurements over Europe and northern Africa with a spatial sampling of 8 km. The main application area of Sentinel-4/UVN is air quality. One of the data products that is being developed for Sentinel-4/UVN is the Aerosol Layer Height (ALH). The goal is to determine the height of aerosol plumes with a resolution of better than 0.5 - 1 km. The ALH product thus targets aerosol layers in the free troposphere, such as desert dust, volcanic ash and biomass during plumes. KNMI is assigned with the development of the Aerosol Layer Height (ALH) algorithm. Its heritage is the ALH algorithm developed by Sanders and De Haan (ATBD, 2016) for the TROPOMI instrument on board the Sentinel-5 Precursor mission that is to be launched in June or July 2016 (tentative date). The retrieval algorithm designed so far for the aerosol height product is based on the absorption characteristics of the oxygen-A band (759-770 nm). The algorithm has heritage to the ALH algorithm developed for TROPOMI on the Sentinel 5 precursor satellite. New aspects for Sentinel-4/UVN include the higher resolution (0.116 nm compared to 0.4 for TROPOMI) and hourly observation from the geostationary orbit. The algorithm uses optimal estimation to obtain a spectral fit of the reflectance across absorption band, while assuming a single uniform layer with fixed width to represent the aerosol vertical distribution. The state vector includes amongst other elements the height of this layer and its aerosol optical

Open Praxis, volumen 4 issue 1

Directory of Open Access Journals (Sweden)

Editor Open Praxis

2010-03-01

Full Text Available - Correlation between Performance and Quality of Academic Staff in National Open University of Nigeria (NOUN Olubiyi Adeniyi Adewale, Timothy Olugbenga Ajadi & Juliet O.Inegbedion (1-7 - Benchmarking E-Learning in UK Universities: Lessons from and for the International Context Paul Bacsich (9-17 - Structural equation modelling of factors affecting success in student’s performance in ODL-Programs: Extending Quality Management concepts Per Bergamin, Simone Ziska & Rudolf Groner (18-25 - Quality Assurance in Open and Distance Learning in India S.K. Gandhe (26-32 - Leading innovative approaches to the financial crisis Sarah Guri-Rosenblit (33-38 - TOWARDS KNOWLEDGE BASED ECONOMIES - the contribution of open distance learning strategies in addressing equity and inclusiveness issues in small states like Mauritius Jheengut (39-63 - New Approaches to Quality Assurance in the Changing World of Higher Education Maria Jose Lemaitre (64-75 - Entrepreneurship: New Challenges for Higher Education Institutions Josep Lladós (76-87 - A Psychometric Study in the Performance of Distance learners Ravi K Mahajan (88-94 - Managing Quality Assurance for Distance Learning Programs in Malaysia Mohd Ismail Ramli (95-101 - Employability and lifelong learning Hazel Simmons-McDonald (102-113

Open access and scholarly communication, part 4

CERN Document Server

Eden, Brad

2009-01-01

This fourth e-book on the subject of open access in the academic field includes a Latin American case study on open access penetration, a paper from Germany on the promotion of OA illustrated by a project at the University of Konstanz, and a case study on OA at Bioline International, a non-profit scholarly publications aggregator, distributor, publisher and publishing assistance service.

Structural response of nuclear containment shield buildings with unanticipated construction openings

Science.gov (United States)

Mac Namara, Sinead Caitriona

As Nuclear Power Plants age many require steam generator replacement. There is a nickel alloy in the steam generator tubes that is susceptible to stress cracking and although these cracks can be sealed the generator becomes uneconomical without 10%-15% of the tubes. The steam generator in a typical nuclear power plant is housed in the containment structure next to the reactor. The equipment hatch is not big enough to facilitate steam generator replacement, thus construction openings in the dome of the containment structure are required. To date the structural consequences of construction openings in the dome have not been examined. This thesis examines the effects of such openings. The prototype concrete dome is made up of a 2 ft thick dome atop 3 ft thick and 170 ft high cylindrical walls (radius 65.5 ft) with a tension ring 15 ft high and 8 ft thick in between. The dome of the building is cast in two layers; a lower 9 inch layer that serves as the formwork for an upper 15 inch layer. The weight of the dome is carried in axial compression along the hoops and meridians of the dome. The first finite element model uses shell elements and considers two limiting load cases; where the two layers act as one, and where the lower layer carries the weight of both. The openings interrupt the hoops and meridians and the weight of the dome must be redistributed around the openings. Without openings, the stresses due to dead load in the structure are very low when compared to the material strength. The impact of the openings is increased compression stresses near the opening. The maximum stresses are approximately four times larger than in the original structure. These results are confirmed by the second model which is made from layers of solid elements. This model shows a significant difference between the compression on the top surface of the dome, in the affected areas, and that on the bottom surface, leading to shear stresses. These shear stresses are largest around the

A Layered Solution Crystal Growth Technique and the Crystal Structure of (C 6H 5C 2H 4NH 3) 2PbCl 4

Science.gov (United States)

Mitzi, D. B.

1999-07-01

Single crystals of the organic-inorganic perovskite (C6H5C2H4NH3)2PbCl4 have been grown at room temperature using a layered solution approach. The bottom solution layer, contained within a long straight tube, consists of PbCl2 dissolved in concentrated aqueous HCl. A less dense layer of methanol is carefully placed on top of the HCl/PbCl2 solution using a syringe. Finally, a stoichiometric quantity of C6H5C2H4NH2 (relative to the PbCl2) is added to the top of the column. As the layers slowly diffuse together, well-formed crystals of (C6H5C2H4NH3)2PbCl4 appear near the interface between the HCl/PbCl2 and C6H5C2H4NH2 solutions. The thick, plate-like crystals are well suited for X-ray crystallography studies. Room temperature intensity data were refined using a triclinic (Poverline1) cell (a=11.1463(3) Å, b=11.2181(3) Å, c=17.6966(5) Å, α= 99.173(1)°, β=104.634(1)°, γ=89.999(1)°, V=2111.8(1) Å3, Z=4, Rf/Rw=0.031/0.044). The organic-inorganic layered perovskite structure features well-ordered sheets of corner-sharing distorted PbCl6 octahedra separated by bilayers of phenethylammonium cations. Tilting and rotation of the PbCl6 octahedra within the perovskite sheets, coupled with organic cation ordering, leads to the unusual in-sheet 2ap×2ap superstructure, where ap is the lattice constant for the ideal cubic perovskite.

OpenStreetMap over WMS

Directory of Open Access Journals (Sweden)

Přemysl Vohnout

2010-02-01

Full Text Available This paper discuss the issues which we faced, while preparing WMS server with OpenStreetMap data of whole Europe. This article is divided into three sections. First is about mandatory applications which are required for working WMS service with OpenStreetMap data. Second is focused on tuning up PostgreSQL. Third is focused on rendering time improvement of layers.

Monolithic PDMS Laminates for Dielectric Elastomer Transducers through Open-Air PlasmATreatment

DEFF Research Database (Denmark)

Hassouneh, Suzan Sager; Oubæk, Jakob; Daugaard, Anders Egede

2016-01-01

The present study investigates the use of an open-air plasma-treatment system for the surface modification of polydimethylsiloxane (PDMS), in order to improve layer-to-layer adhesion. The procedure presented herein is more cost efficient compared to conventional vacuum-based plasma-treatment, and......The present study investigates the use of an open-air plasma-treatment system for the surface modification of polydimethylsiloxane (PDMS), in order to improve layer-to-layer adhesion. The procedure presented herein is more cost efficient compared to conventional vacuum-based plasma...

Effects of stress on the oxide layer thickness and post-oxidation creep strain of zircaloy-4

International Nuclear Information System (INIS)

Lim, Sang Ho; Yoon, Young Ku

1986-01-01

Effects of compressive stress generated in the oxide layer and its subsequent relief on oxidation rate and post-oxidation creep characteristics of zircaloy-4 were investigated by oxidation studies in steam with and without applied tensile stress and by creep testing at 700 deg C in high purity argon. The thickness of oxide layer increased with the magnitude of tensile stress applied during oxidation at 650 deg C in steam whereas similar phenomenon was not observed during oxidation at 800 deg C. Zircaloy-4 specimens oxidized at 600 deg C in steam without applied stress exhibited higher creep strain than that shown by unoxidized specimens when creep-tested in argon. Zircaloy-4 specimens oxidized at 600 deg C steam under the applied stress of 8.53MPa and oxidized at 800 deg C under the applied stress of 0 and 8.53MPa exhibited lower strain than that shown by unoxidized specimen. The above experimental results were accounted for on the basis of interactions among applied stress during oxidation, compressive stress generated in the oxide layer and elasticity of zircaloy-4 matrix. (Author)

DNA Open states and DNA hydratation

International Nuclear Information System (INIS)

Lema-Larre, B. de; Martin-Landrove, M

1995-01-01

It is a very well-known fact that an protonic exchange exists among natural DNA filaments and synthetic polynucleotides with the solvent (1--2). The existence of DNA open states, that is to say states for which the interior of the DNA molecule is exposed to the external environment, it has been demonstrated by means of proton-deuterium exchange (3). This work has carried out experiments measuring the dispersion of the traverse relaxation rate (4), as a pulsation rate function in a Carr-Purcell-Meiboom-Gill (CPMG) pulses sequence rate, to determine changes in the moist layer of the DNA molecule. The experiments were carried out under different experimental conditions in order to vary the probability that open states occurs, such as temperature or the exposure to electromagnetic fields. Some theoretical models were supposed to adjust the experimental results including those related to DNA non linear dynamic [es

Hyperpolarization moves S4 sensors inward to open MVP, a methanococcal voltage-gated potassium channel.

Science.gov (United States)

Sesti, Federico; Rajan, Sindhu; Gonzalez-Colaso, Rosana; Nikolaeva, Natalia; Goldstein, Steve A N

2003-04-01

MVP, a Methanococcus jannaschii voltage-gated potassium channel, was cloned and shown to operate in eukaryotic and prokaryotic cells. Like pacemaker channels, MVP opens on hyperpolarization using S4 voltage sensors like those in classical channels activated by depolarization. The MVP S4 span resembles classical sensors in sequence, charge, topology and movement, traveling inward on hyperpolarization and outward on depolarization (via canaliculi in the protein that bring the extracellular and internal solutions into proximity across a short barrier). Thus, MVP opens with sensors inward indicating a reversal of S4 position and pore state compared to classical channels. Homologous channels in mammals and plants are expected to function similarly.

Issues Identified During September 2016 IBM OpenMP 4.5 Hackathon

Energy Technology Data Exchange (ETDEWEB)

Richards, David F. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2017-03-15

In September, 2016 IBM hosted an OpenMP 4.5 Hackathon at the TJ Watson Research Center. Teams from LLNL, ORNL, SNL, LANL, and LBNL attended the event. As with the 2015 hackathon, IBM produced an extremely useful and successful event with unmatched support from compiler team, applications staff, and facilities. Approximately 24 IBM staff supported 4-day hackathon and spent significant time 4-6 weeks out to prepare environment and become familiar with apps. This hackathon was also the first event to feature LLVM & XL C/C++ and Fortran compilers. This report records many of the issues encountered by the LLNL teams during the hackathon.

Quality Evaluation for Microcrystalline Silicon Thin-Film Solar Cells by Single-Layer Absorption

Directory of Open Access Journals (Sweden)

Sheng-Hui Chen

2012-01-01

Full Text Available The absorption coefficient at 1.4 eV is divided by the value at 0.9 eV to obtain the factor used to judge the quality of μc-Si:H. PV device performance can be predicted by multiplying Voc with Isc when using this layer as an intrinsic layer. The results show a good relationship between the quality factor and the product of open-circuit voltage and short-circuit current. However, the final efficiency is influenced by the identities of the interface in the multilayer structure.

Performance improvement of charge-trap memory by using a stacked Zr_0_._4_6Si_0_._5_4O_2/Al_2O_3 charge-trapping layer

International Nuclear Information System (INIS)

Tang, Zhenjie; Hu, Dan; Zhang, Xiwei; Zhao, Yage; Li, Rong

2016-01-01

The postdeposition annealing (PDA)-treated charge-trap flash memory capacitor with stacked Zr_0_._4_6Si_0_._5_4O_2/Al_2O_3 charge-trapping layer flanked by a SiO_2 tunneling oxide and an Al_2O_3 blocking oxide was fabricated and investigated. It is observed that the memory capacitor exhibits prominent memory characteristics with large memory windows 12.8 V in a ±10 V gate sweeping voltage range, faster program/erase speed, and good data-retention characteristics even at 125 C compared to a single charge-trapping layer (Zr_0_._4_6Si_0_._5_4O_2, Zr_0_._7_9Si_0_._2_1O_2, and Zr_0_._4_6Al_1_._0_8O_2_._5_4). The quantum wells and introduced interfacial traps of the stacked trapping layer regulate the storage and loss behavior of charges, and jointly contribute to the improved memory characteristics. Hence, the memory capacitor with a stacked trapping layer is a promising candidate in future nonvolatile charge-trap memory device design and application. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Modification of back electrode with WO3 layer and its effect on Cu2ZnSn(S,Se)4-based solar cells

Science.gov (United States)

Shi, Kun; Yao, Bin; Li, Yongfeng; Ding, Zhanhui; Deng, Rui; Sui, Yingrui; Zhang, Zhenzhong; Zhao, Haifeng; Zhang, Ligong

2018-01-01

In the present work, we designed and prepared Cu2ZnSn(S,Se)4 (CZTSSe)-based solar cells with a new structure of Al/ITO/ZnO/CdS/CZTSSe/WO3/Mo/SLG (S1-5) by depositing about 5-nm-thick WO3 layer with monoclinic structure on the back electrode Mo/SLG of solar cells with the convention structure of Al/ITO/ZnO/CdS/CZTSSe/Mo/SLG (S2), with the aim of improving the power conversion efficiency (PCE) of CZTSSe-based solar cells. It is found that the average open circuit voltage (Voc) increases from 346.7 mV of the S2 cells to 400.9 mV of the S1-5 cells, the average short circuit current density (Jsc) from 26.4 mA/cm2 to 32.1 mA/cm2 and the filling factor (FF) from 33.8 to 40.0 by addition of the WO3 layer, which results in that the average PCE increases from 3.10% of the S2 cells to 5.14% of the S1-5 cells. The average increasing percent of the PCE is 65.8%. The increase in Voc, Jsc and FF of the S1-5 cells compared to the S2 cells is attributed to that the WO3 layer prevent the Se coming from Se ambient and CZTSSe to react with the Mo to form MoSe2 and other second phases, which makes the shunt resistance (Rsh) of the S1-5 increase and the series resistance (Rs) and reverse saturation current density (J0) decrease compared to the S2 cells. The decreased J0 is main factor of improvement of the PCE. A mechanism of influence of the Rsh, Rs and J0 on the PCE is also revealed. Our result demonstrates that addition of the WO3 layer with a reasonable thickness can be a promising technical route of improving the PCE of the CZTSSe-based solar cell.

Multi-layer micro/nanofluid devices with bio-nanovalves

Science.gov (United States)

Li, Hao; Ocola, Leonidas E.; Auciello, Orlando H.; Firestone, Millicent A.

2013-01-01

A user-friendly multi-layer micro/nanofluidic flow device and micro/nano fabrication process are provided for numerous uses. The multi-layer micro/nanofluidic flow device can comprise: a substrate, such as indium tin oxide coated glass (ITO glass); a conductive layer of ferroelectric material, preferably comprising a PZT layer of lead zirconate titanate (PZT) positioned on the substrate; electrodes connected to the conductive layer; a nanofluidics layer positioned on the conductive layer and defining nanochannels; a microfluidics layer positioned upon the nanofluidics layer and defining microchannels; and biomolecular nanovalves providing bio-nanovalves which are moveable from a closed position to an open position to control fluid flow at a nanoscale.

Chemical interaction of B4C, B, and C with Mo/Si layered structures

International Nuclear Information System (INIS)

Rooij-Lohmann, V. I. T. A. de; Veldhuizen, L. W.; Zoethout, E.; Yakshin, A. E.; Kruijs, R. W. E. van de; Thijsse, B. J.; Gorgoi, M.; Schaefers, F.; Bijkerk, F.

2010-01-01

To enhance the thermal stability, B 4 C diffusion barrier layers are often added to Mo/Si multilayer structures for extreme ultraviolet optics. Knowledge about the chemical interaction between B 4 C and Mo or Si, however is largely lacking. Therefore, the chemical processes during annealing up to 600 deg. C of a Mo/B 4 C/Si layered structure have been investigated in situ with hard x-ray photoelectron spectroscopy and ex situ with depth profiling x-ray photoelectron spectroscopy. Mo/B/Si and Mo/C/Si structures have also been analyzed as reference systems. The chemical processes in these systems have been identified, with two stages being distinguished. In the first stage, B and C diffuse and react predominantly with Mo. MoSi x forms in the second stage. If the diffusion barrier consists of C or B 4 C, a compound forms that is stable up to the maximum probed temperature and annealing time. We suggest that the diffusion barrier function of B 4 C interlayers as reported in literature can be caused by the stability of the formed compound, rather than by the stability of B 4 C itself.

Solid-state synthesis, structure and properties of a novel open-framework cadmium selenite bromide: [Cd10(SeO3)8Br4]·HBr·H2O

International Nuclear Information System (INIS)

Chen, Wen-Tong; Wang, Ming-Sheng; Wang, Guan-E; Chen, Hui-Fen; Guo, Guo-Cong

2013-01-01

A novel open-framework cadmium selenite bromide, [Cd 10 (SeO 3 ) 8 Br 4 ]·HBr·H 2 O (1), has been obtained by a solid-state reaction at 450 °C, and the structure has been determined by single-crystal X-ray diffraction analysis. Compound 1 crystallizes in Pbcm of the orthorhombic system: a=10.882(3), b=16.275(5), c=18.728(6) Å, V=3317(2) Å 3 , R1/wR2=0.0411/0.0659. Compound 1 is characteristic of a novel 3-D open-framework structure, composing ∞ 2 [CdSeO 3 ] layers and the pillars of edge-shared CdO 3 Br 2 square pyramids. The lattice water molecules and the HBr molecules locate in the voids of the framework. Optical absorption spectrum of 1 reveals the presence of an optical gap of 1.65 eV. Solid-state photoluminescent study indicates that compound 1 exhibits strong violet emission. TG–DSC measurement shows that compound 1 is thermally stable up to 200 °C. - Graphical abstract: A metal selenite halide has been synthesized and features a 3-D open-framework structure, composing edge-shared CdO 8 decahedra and pillars of edge-sharing pentahedra. UV–vis, TG–DSC and luminescent measurements are also reported. Highlights: • This paper reports a novel cadmium selenite bromide obtained by an intermediate-temperature solid-state reaction. • The title compound is characteristic of a novel 3-D open-framework structure, composing ∞ 2 [CdSeO 3 ] layers and the pillars of edge-shared CdO 3 Br 2 square pyramids. • The title compound is thermally stable up to 200 °C. • The title compound has an optical gap of 1.65 eV and exhibits strong violet emission

Effect of a gate buffer layer on the performance of a 4H-SiC Schottky barrier field-effect transistor

International Nuclear Information System (INIS)

Zhang Xianjun; Yang Yintang; Chai Changchun; Duan Baoxing; Song Kun; Chen Bin

2012-01-01

A lower doped layer is inserted between the gate and channel layer and its effect on the performance of a 4H-SiC Schottky barrier field-effect transistor (MESFET) is investigated. The dependences of the drain current and small signal parameters on this inserted gate-buffer layer are obtained by solving one-dimensional (1-D) and two-dimensional (2-D) Poisson's equations. The drain current and small signal parameters of the 4H-SiC MESFET with a gate-buffer layer thickness of 0.15 μm are calculated and the breakdown characteristics are simulated. The results show that the current is increased by increasing the thickness of the gate-buffer layer; the breakdown voltage is 160 V, compared with 125 V for the conventional 4H-SiC MESFET; the cutoff frequency is 27 GHz, which is higher than 20 GHz of the conventional structure due to the lower doped gate-buffer layer. (semiconductor devices)

Cu2+ in layered compounds: origin of the compressed geometry in the model system K2ZnF4:Cu2+.

Science.gov (United States)

Aramburu, J A; García-Lastra, J M; García-Fernández, P; Barriuso, M T; Moreno, M

2013-06-17

results underline the key role played by ab initio calculations for unveiling all the complexity behind the properties of the model system K2ZnF4:Cu(2+), opening at the same time a window for improving our knowledge on d(9), d(7), or d(4) ions in other layered compounds.

Predictors of death and production performance of layer chickens in opened and sealed pens in a tropical savannah environment.

Science.gov (United States)

Shittu, Aminu; Raji, Abdullahi Abdullahi; Madugu, Shuaibu A; Hassan, Akinola Waheed; Fasina, Folorunso Oludayo

2014-09-12

Layer chickens are exposed to high risks of production losses and mortality with impact on farm profitability. The harsh tropical climate and severe disease outbreaks, poor biosecurity, sub-minimal vaccination and treatment protocols, poor management practices, poor chick quality, feed-associated causes, and unintended accidents oftentimes aggravate mortality and negatively affect egg production. The objectives of this study were to estimate the probability of survival and evaluate risk factors for death under different intensive housing conditions in a tropical climate, and to assess the production performance in the housing systems. Daily mean mortality percentages and egg production figures were significantly lower and higher in the sealed pens and open houses (P ratio for mortality of layers raised in sealed pens was 0.568 (56.8%). Reasons for spiked mortality in layer chickens may not always be associated with disease. Hot-dry climatic environment is associated with heat stress, waning immunity and inefficient feed usage and increase probability of death with reduced egg production; usage of environmentally controlled building in conditions where environmental temperature may rise significantly above 25°C will reduce this impact. Since younger birds (19-38 weeks) are at higher risk of death due to stress of coming into production, management changes and diseases, critical implementation of protocols that will reduce death at this precarious period becomes mandatory. Whether older chickens' better protection from death is associated with many prophylactic and metaphylactic regimen of medications/vaccination will need further investigation.

Relaxation of photodielectric effect in Pb3O4 layers

International Nuclear Information System (INIS)

Avanesyan, V. T.; Baranova, E. P.

2007-01-01

Experimental data on the kinetics of the photodielectric effect in layers of red lead (Pb 3 O 4 ) are reported. The photocapacitive properties and dielectric loss under photoexcitation have been studied with the spectral composition of light varied at low frequencies of the measuring field. The dielectric parameters attain steady values long after light is switched on (off). The relationship of the photodielectric phenomena with structural features of the semiconductor and, in particular, with the presence of lone pair electrons of Pb 2+ cations is discussed

The evolution of an unsteady translating nonlinear rossby-wave critical layer

Science.gov (United States)

Haynes, Peter H.; Cowley, Stephen J.

When a monochromatic Rossby wave is forced on a flow which is slowly varying in time, the location of the critical line, where the phase speed of the wave is equal to that of the flow, also slowly changes. It is shown that this translation can play an important role in the vorticity balance near the critical line. The behavior of the translating critical layer is analyzed for various values of y, a parameter which measures the relative importance of nonlinear advection and translation. First, the vorticity equation in the critical layer is solved numerically in an important special case, where the velocity field in the critical layer is independent of the vorticity distribution and constant in time. The solutions reveal a number of new aspects of the behavior which are introduced by the translation, including the formation of a wake behind the critical layer, and the possibility of "trapping" of fluid particles in the critical layer if y exceeds a threshold value. Viewed in a frame of reference moving with the critical line the vorticity distribution may tend to a steady state, except in a "vorticity front" far downstream in the wake. If streamlines in the critical layer are open this steady state may be a predominantly inviscid one; if they are closed a steady state is possible only with non-zero dissipation. For both the unsteady and steady flows the translation allows the "logarithmic phase jump" across the critical layer, 4, to be non-zero and negative. Hence, even when the viscosity is vanishingly small, the critical layer can act as a strong "absorber" of Eliassen-Palm wave activity. Second, steady-state solutions are obtained numerically for a case when the velocity field in the critical layer is not independent of the vorticity distribution there. The interaction restricts the formation of closed streamlines, and an asymptotic open-streamline solution for large y can be found. The critical layer again acts an absorber of wave activity, but with decreasing e

Low-noise encoding of active touch by layer 4 in the somatosensory cortex.

Science.gov (United States)

Hires, Samuel Andrew; Gutnisky, Diego A; Yu, Jianing; O'Connor, Daniel H; Svoboda, Karel

2015-08-06

Cortical spike trains often appear noisy, with the timing and number of spikes varying across repetitions of stimuli. Spiking variability can arise from internal (behavioral state, unreliable neurons, or chaotic dynamics in neural circuits) and external (uncontrolled behavior or sensory stimuli) sources. The amount of irreducible internal noise in spike trains, an important constraint on models of cortical networks, has been difficult to estimate, since behavior and brain state must be precisely controlled or tracked. We recorded from excitatory barrel cortex neurons in layer 4 during active behavior, where mice control tactile input through learned whisker movements. Touch was the dominant sensorimotor feature, with >70% spikes occurring in millisecond timescale epochs after touch onset. The variance of touch responses was smaller than expected from Poisson processes, often reaching the theoretical minimum. Layer 4 spike trains thus reflect the millisecond-timescale structure of tactile input with little noise.

Solid oxide fuel cells with bi-layered electrolyte structure

Energy Technology Data Exchange (ETDEWEB)

Zhang, Xinge; Robertson, Mark; Deces-Petit, Cyrille; Xie, Yongsong; Hui, Rob; Qu, Wei; Kesler, Olivera; Maric, Radenka; Ghosh, Dave [Institute for Fuel Cell Innovation, National Research Council Canada, 4250 Wesbrook Mall, Vancouver, B.C. V6T 1W5 (Canada)

2008-01-10

In this work, we have developed solid oxide fuel cells with a bi-layered electrolyte of 2 {mu}m SSZ and 4 {mu}m SDC using tape casting, screen printing, and co-firing processes. The cell reached power densities of 0.54 W cm{sup -2} at 650 C and 0.85 W cm{sup -2} at 700 C, with open circuit voltage (OCV) values larger than 1.02 V. The electrical leaking between anode and cathode through an SDC electrolyte has been blocked in the bi-layered electrolyte structure. However, both the electrolyte resistance (R{sub el}) and electrode polarization resistance (R{sub p,a+c}) increased in comparison to cells with single-layered SDC electrolytes. The formation of a solid solution of (Ce, Zr)O{sub 2-x} during sintering process and the flaws in the bi-layered electrolyte structure seem to be the main causes for the increase in the R{sub el} value (0.32 {omega} cm{sup 2}) at 650 C, which is almost one order of magnitude higher than the calculated value. (author)

Efficient Planar Structured Perovskite Solar Cells with Enhanced Open-Circuit Voltage and Suppressed Charge Recombination Based on a Slow Grown Perovskite Layer from Lead Acetate Precursor.

Science.gov (United States)

Li, Cong; Guo, Qiang; Wang, Zhibin; Bai, Yiming; Liu, Lin; Wang, Fuzhi; Zhou, Erjun; Hayat, Tasawar; Alsaedi, Ahmed; Tan, Zhan'ao

2017-12-06

For planar structured organic-inorganic hybrid perovskite solar cells (PerSCs) with the poly(3,4-ethylenedioxythiophene:polystyrene sulfonate) (PEDOT:PSS) hole transport layer, the open-circuit voltage (V oc ) of the device is limited to be about 1.0 V, resulting in inferior performance in comparison with TiO 2 -based planar counterparts. Therefore, increasing V oc of the PEDOT:PSS-based planar device is an important way to enhance the efficiency of the PerSCs. Herein, we demonstrate a novel approach for perovskite film formation and the film is formed by slow growth from lead acetate precursor via a one-step spin-coating process without the thermal annealing (TA) process. Because the perovskite layer grows slowly and naturally, high-quality perovskite film can be achieved with larger crystalline particles, less defects, and smoother surface morphology. Ultraviolet absorption, X-ray diffraction, scanning electron microscopy, steady-state fluorescence spectroscopy (photoluminescence), and time-resolved fluorescence spectroscopy are used to clarify the crystallinity, morphology, and internal defects of perovskite thin films. The power conversion efficiency of p-i-n PerSCs based on slow-grown film (16.33%) shows greatly enhanced performance compared to that of the control device based on traditional thermally annealed perovskite film (14.33%). Furthermore, the V oc of the slow-growing device reaches 1.12 V, which is 0.1 V higher than that of the TA device. These findings indicate that slow growth of the perovskite layer from lead acetate precursor is a promising approach to achieve high-quality perovskite film for high-performance PerSCs.

Numerical simulations of the stratified oceanic bottom boundary layer

Science.gov (United States)

Taylor, John R.

Numerical simulations are used to consider several problems relevant to the turbulent oceanic bottom boundary layer. In the first study, stratified open channel flow is considered with thermal boundary conditions chosen to approximate a shallow sea. Specifically, a constant heat flux is applied at the free surface and the lower wall is assumed to be adiabatic. When the surface heat flux is strong, turbulent upwellings of low speed fluid from near the lower wall are inhibited by the stable stratification. Subsequent studies consider a stratified bottom Ekman layer over a non-sloping lower wall. The influence of the free surface is removed by using an open boundary condition at the top of the computational domain. Particular attention is paid to the influence of the outer layer stratification on the boundary layer structure. When the density field is initialized with a linear profile, a turbulent mixed layer forms near the wall, which is separated from the outer layer by a strongly stable pycnocline. It is found that the bottom stress is not strongly affected by the outer layer stratification. However, stratification reduces turbulent transport to the outer layer and strongly limits the boundary layer height. The mean shear at the top of the boundary layer is enhanced when the outer layer is stratified, and this shear is strong enough to cause intermittent instabilities above the pycnocline. Turbulence-generated internal gravity waves are observed in the outer layer with a relatively narrow frequency range. An explanation for frequency content of these waves is proposed, starting with an observed broad-banded turbulent spectrum and invoking linear viscous decay to explain the preferential damping of low and high frequency waves. During the course of this work, an open-source computational fluid dynamics code has been developed with a number of advanced features including scalar advection, subgrid-scale models for large-eddy simulation, and distributed memory

Interface modification of organic photovoltaics by combining molybdenum oxide (MoO{sub x}) and molecular template layer

Energy Technology Data Exchange (ETDEWEB)

Duan, Haichao [Institute of Super-microstructure and Ultrafast Process in Advanced Materials, School of Physics and Electronics, Central South University, Changsha, Hunan 410083 (China); Hunan Key Laboratory for Super-microstructure and Ultrafast Process, School of Physics and Electronics, Central South University, Changsha, Hunan 410083 (China); Yang, Junliang, E-mail: junliang.yang@csu.edu.cn [Institute of Super-microstructure and Ultrafast Process in Advanced Materials, School of Physics and Electronics, Central South University, Changsha, Hunan 410083 (China); Hunan Key Laboratory for Super-microstructure and Ultrafast Process, School of Physics and Electronics, Central South University, Changsha, Hunan 410083 (China); Fu, Lin; Xiong, Jian; Yang, Bingchu; Ouyang, Jun; Zhou, Conghua; Huang, Han [Institute of Super-microstructure and Ultrafast Process in Advanced Materials, School of Physics and Electronics, Central South University, Changsha, Hunan 410083 (China); Hunan Key Laboratory for Super-microstructure and Ultrafast Process, School of Physics and Electronics, Central South University, Changsha, Hunan 410083 (China); Gao, Yongli [Institute of Super-microstructure and Ultrafast Process in Advanced Materials, School of Physics and Electronics, Central South University, Changsha, Hunan 410083 (China); Hunan Key Laboratory for Super-microstructure and Ultrafast Process, School of Physics and Electronics, Central South University, Changsha, Hunan 410083 (China); Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627 (United States)

2015-01-01

We report discrete heterojunction small molecular organic photovoltaics (OPVs) with enhanced performance by modifying the interface using molybdenum oxide (MoO{sub x}) and molecular template layer perylene-3,4,9,10-tetracarboxylic-3,4,9,10-dianhydride (PTCDA). A large increase in open-circuit voltage was obtained in copper phthalocyanine/fullerene, i.e., CuPc/C{sub 60} and CuPc/PCBM, discrete planar heterojunction photovoltaics with an insertion of 5 nm MoO{sub x} hole transport layer at the interface between the anode electrode and the CuPc donor layer. It results from the band bending at the interface and the pinning of the highest occupied molecular orbital level of CuPc to the Fermi level of MoO{sub x} due to the defect states (oxygen vacancies) in MoO{sub x} thin films. Moreover, the short-circuit current showed an efficient improvement by inserting a 1 nm PTCDA layer at the interface between the MoO{sub x} layer and the CuPc layer. The PTCDA layer induces the growth of CuPc thin film with lying-down molecular arrangement, supporting the charge transports along the vertical direction. The power conversion efficiencies of CuPc/C{sub 60} and CuPc/PCBM discrete planar heterojunction photovoltaic devices were improved from about 0.80% to 1.50% with inserting both MoO{sub x} and PTCDA layers. The results suggest that the performance of organic discrete planar heterojunction photovoltaics could be optimized by interface modification with combining hole transport layer and molecular template layer, which are potentially suitable for other highly efficient OPVs, such as small molecular tandem OPVs. - Highlights: • Organic small molecule photovoltaics were fabricated by interface modification. • An inserted molybdenum oxide layer largely enhances open-circuit voltage. • An inserted molecular template layer dramatically improves short-circuit current. • The power conversion efficiencies are almost doubled with interface modification.

Spectrally-resolved UV photodesorption of CH4 in pure and layered ices

Science.gov (United States)

Dupuy, R.; Bertin, M.; Féraud, G.; Michaut, X.; Jeseck, P.; Doronin, M.; Philippe, L.; Romanzin, C.; Fillion, J.-H.

2017-07-01

Context. Methane is among the main components of the ice mantles of interstellar dust grains, where it is at the start of a rich solid-phase chemical network. Quantification of the photon-induced desorption yield of these frozen molecules and understanding of the underlying processes is necessary to accurately model the observations and the chemical evolution of various regions of the interstellar medium. Aims: This study aims at experimentally determining absolute photodesorption yields for the CH4 molecule as a function of photon energy. The influence of the ice composition is also investigated. By studying the methane desorption from layered CH4:CO ice, indirect desorption processes triggered by the excitation of the CO molecules are monitored and quantified. Methods: Tunable monochromatic vacuum ultraviolet light (VUV) light from the DESIRS beamline of the SOLEIL synchrotron is used in the 7-13.6 eV (177-91 nm) range to irradiate pure CH4 or layers of CH4 deposited on top of CO ice samples. The release of species in the gas phase is monitored by quadrupole mass spectrometry, and absolute photodesorption yields of intact CH4 are deduced. Results: CH4 photodesorbs for photon energies higher than 9.1 eV ( 136 nm). The photodesorption spectrum follows the absorption spectrum of CH4, which confirms a desorption mechanism mediated by electronic transitions in the ice. When it is deposited on top of CO, CH4 desorbs between 8 and 9 eV with a pattern characteristic of CO absorption, indicating desorption induced by energy transfer from CO molecules. Conclusions: The photodesorption of CH4 from pure ice in various interstellar environments is around 2.0 ± 1.0 × 10-3 molecules per incident photon. Results on CO-induced indirect desorption of CH4 provide useful insights for the generalization of this process to other molecules co-existing with CO in ice mantles.

Assembly of 1D nanofibers into a 2D bi-layered composite nanofibrous film with different functionalities at the two layers via layer-by-layer electrospinning.

Science.gov (United States)

Wang, Zijiao; Ma, Qianli; Dong, Xiangting; Li, Dan; Xi, Xue; Yu, Wensheng; Wang, Jinxian; Liu, Guixia

2016-12-21

A two-dimensional (2D) bi-layered composite nanofibrous film assembled by one-dimensional (1D) nanofibers with trifunctionality of electrical conduction, magnetism and photoluminescence has been successfully fabricated by layer-by-layer electrospinning. The composite film consists of a polyaniline (PANI)/Fe 3 O 4 nanoparticle (NP)/polyacrylonitrile (PAN) tuned electrical-magnetic bifunctional layer on one side and a Tb(TTA) 3 (TPPO) 2 /polyvinylpyrrolidone (PVP) photoluminescent layer on the other side, and the two layers are tightly combined face-to-face together into the novel bi-layered composite film of trifunctionality. The brand-new film has totally different characteristics at the double layers. The electrical conductivity and magnetism of the electrical-magnetic bifunctional layer can be, respectively, tunable via modulating the PANI and Fe 3 O 4 NP contents, and the highest electrical conductivity can reach up to the order of 10 -2 S cm -1 , and predominant intense green emission at 545 nm is obviously observed in the photoluminescent layer under the excitation of 357 nm single-wavelength ultraviolet light. More importantly, the luminescence intensity of the photoluminescent layer remains almost unaffected by the electrical-magnetic bifunctional layer because the photoluminescent materials have been successfully isolated from dark-colored PANI and Fe 3 O 4 NPs. By comparing with the counterpart single-layered composite nanofibrous film, it is found that the bi-layered composite nanofibrous film has better performance. The novel bi-layered composite nanofibrous film with trifunctionality has potential in the fields of nanodevices, molecular electronics and biomedicine. Furthermore, the design conception and fabrication technique for the bi-layered multifunctional film provide a new and facile strategy towards other films of multifunctionality.

A novel layered bimetallic phosphite intercalating with organic amines: Synthesis and characterization of Co(H2O)4Zn4(HPO3)6.C2N2H1

International Nuclear Information System (INIS)

Lin Zhien; Fan Wei; Gao Feifei; Chino, Naotaka; Yokoi, Toshiyuki; Okubo, Tatsuya

2006-01-01

A new layered cobalt-zinc phosphite, Co(H 2 O) 4 Zn 4 (HPO 3 ) 6 .C 2 N 2 H 1 has been synthesized in the presence of ethylenediamine as the structure-directing agent. The compound crystallizes in the monoclinic system, space group Cc (No. 9), a=18.2090(8), b=9.9264(7), c=15.4080(7) A, β=114.098(4) o , V=2542.3(2) A 3 , Z=4, R=0.0323, wR=0.0846. The structure consists of ZnO 4 tetrahedra, CoO 6 octahedra and HPO 3 pseudopyramids through their vertices forming bimetallic phosphite layers parallel to the ab plane. Organic cations, which reside between the inorganic layers, are mobile and can be exchanged by NH 4 + cations without the collapse of the framework

[Effects of Acupuncture Stimulation of Different Layers of "Tianshu" (ST 25) Region on Changes of Intra-colonic Pressure in Normal Rats].

Science.gov (United States)

Sun, Xue-Yi; Yu, Zhi; Chen, Zhi-Yu; Xu, Bin

2018-02-25

To observe the effect of manual acupuncture stimulation of different layers (skin, muscle, peritoneum, sub-peritoneum) of "Tianshu" (ST 25) region on proximal colonic pressure in normal rats. Forty-eight male SD rats were divided into 6 groups: all layer-needling, brushing, cutaneous needling, muscular needling, peritoneum-needling and sub-peritoneum-needling groups ( n ＝8 in each group). Manual needling or brushing was applied to "Tianshu" (ST 25) region. The colonic internal pressure was measured by using an amplifier and a pressure transducer-connected balloon which was implanted into the colonic cavity about 6 cm from the ileocecal valve. For rats of the all-layer needling group, an acupuncture needle was inserted into ST 25 about 1 cm deep and rotated for a while, for rats of the brushing group, a Chinese calligraphy brush pen was used to brush the skin hair for 1 min. For rats of the rest 4 groups, an acupuncture needle was inserted into the skin, muscle layer after cutting open the skin (about 0.1 cm), the peritoneum layer after cutting open the skin and muscle layers, and the sub-peritoneum layer after cutting open the skin, muscle and peritoneum layers, respectively, and rotated using the uniform reinforcing-reducing technique for about 1 min at a frequency of 120 twirlings per minute every time. During manual needling stimulation of the full layers, cutaneous layer, muscle layer, peritoneum layer and the sub-peritoneum layer of bilateral "Tianshu" (ST 25), the internal pressure of proximal colon was significantly decreased relevant to pre-stimulation in each group ( P 0.05). During hair brushing of ST 25 region, the colonic pressure was observably increased relevant to pre-needling stimulation ( P ST 25 on both sides may lower internal pressure of proximal colon in normal rats, suggesting their involvement of acupuncture effect in relaxing proximal colonic contraction.

Dimensions of Open Research: Critical Reflections on Openness in the ROER4D Project

Science.gov (United States)

King, Thomas; Hodgkinson-Williams, Cheryl; Willmers, Michelle; Walji, Sukaina

2016-01-01

Open Research has the potential to advance the scientific process by improving the transparency, rigour, scope and reach of research, but choosing to experiment with Open Research carries with it a set of ideological, legal, technical and operational considerations. Researchers, especially those in resource-constrained situations, may not be aware…

Segmented inner plexiform layer thickness as a potential biomarker to evaluate open-angle glaucoma: Dendritic degeneration of retinal ganglion cell.

Directory of Open Access Journals (Sweden)

Eun Kyoung Kim

Full Text Available To evaluate the changes of retinal nerve fiber layer (RNFL, ganglion cell layer (GCL, inner plexiform layer (IPL, and ganglion cell-inner plexiform layer (GCIPL thicknesses and compare structure-function relationships of 4 retinal layers using spectral-domain optical coherence tomography (SD-OCT in macular region of glaucoma patients.In cross-sectional study, a total of 85 eyes with pre-perimetric to advanced glaucoma and 26 normal controls were enrolled. The glaucomatous eyes were subdivided into three groups according to the severity of visual field defect: a preperimetric glaucoma group, an early glaucoma group, and a moderate to advanced glaucoma group. RNFL, GCL, IPL, and GCIPL thicknesses were measured at the level of the macula by the Spectralis (Heidelberg Engineering, Heidelberg, Germany SD-OCT with automated segmentation software. For functional evaluation, corresponding mean sensitivity (MS values were measured using 24-2 standard automated perimetry (SAP.RNFL, GCL, IPL, and GCIPL thicknesses were significantly different among 4 groups (P < .001. Macular structure losses were positively correlated with the MS values of the 24-2 SAP for RNFL, GCL, IPL, and GCIPL (R = 0.553, 0.636, 0.648 and 0.646, respectively, P < .001. In regression analysis, IPL and GCIPL thicknesses showed stronger association with the corresponding MS values of 24-2 SAP compared with RNFL and GCL thicknesses (R2 = 0.420, P < .001 for IPL; R2 = 0.417, P< .001 for GCIPL thickness.Segmented IPL thickness was significantly associated with the degree of glaucoma. Segmental analysis of the inner retinal layer including the IPL in macular region may provide valuable information for evaluating glaucoma.

Segmented inner plexiform layer thickness as a potential biomarker to evaluate open-angle glaucoma: Dendritic degeneration of retinal ganglion cell.

Science.gov (United States)

Kim, Eun Kyoung; Park, Hae-Young Lopilly; Park, Chan Kee

2017-01-01

To evaluate the changes of retinal nerve fiber layer (RNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), and ganglion cell-inner plexiform layer (GCIPL) thicknesses and compare structure-function relationships of 4 retinal layers using spectral-domain optical coherence tomography (SD-OCT) in macular region of glaucoma patients. In cross-sectional study, a total of 85 eyes with pre-perimetric to advanced glaucoma and 26 normal controls were enrolled. The glaucomatous eyes were subdivided into three groups according to the severity of visual field defect: a preperimetric glaucoma group, an early glaucoma group, and a moderate to advanced glaucoma group. RNFL, GCL, IPL, and GCIPL thicknesses were measured at the level of the macula by the Spectralis (Heidelberg Engineering, Heidelberg, Germany) SD-OCT with automated segmentation software. For functional evaluation, corresponding mean sensitivity (MS) values were measured using 24-2 standard automated perimetry (SAP). RNFL, GCL, IPL, and GCIPL thicknesses were significantly different among 4 groups (P < .001). Macular structure losses were positively correlated with the MS values of the 24-2 SAP for RNFL, GCL, IPL, and GCIPL (R = 0.553, 0.636, 0.648 and 0.646, respectively, P < .001). In regression analysis, IPL and GCIPL thicknesses showed stronger association with the corresponding MS values of 24-2 SAP compared with RNFL and GCL thicknesses (R2 = 0.420, P < .001 for IPL; R2 = 0.417, P< .001 for GCIPL thickness). Segmented IPL thickness was significantly associated with the degree of glaucoma. Segmental analysis of the inner retinal layer including the IPL in macular region may provide valuable information for evaluating glaucoma.

Variations in depth-dose data between open and wedge fields for 4-MV x-rays

International Nuclear Information System (INIS)

Sewchand, W.; Khan, F.M.; Williamson, J.

1978-01-01

Central-axis depth-dose data for 4-MV x rays, including tissue-maximum ratios, were measured for wedge fields. Comparison with corresponding open-field data revealed differences in magnitude which increased with depth, field size, and wedge thickness. However, phantom scatter correction factors for the wedge fields differed less than 1% from corresponding open-field factors. The differences in central-axis percent depth doses between the two types of fields indicate beam hardening by the wedge filter. This study also implies that the derivation of tissue-maximum ratios from central-axis percent depth is as valid for wedge as for open fields

Turbulence Scaling Comparisons in the Ocean Surface Boundary Layer

Science.gov (United States)

Esters, L.; Breivik, Ø.; Landwehr, S.; ten Doeschate, A.; Sutherland, G.; Christensen, K. H.; Bidlot, J.-R.; Ward, B.

2018-03-01

Direct observations of the dissipation rate of turbulent kinetic energy, ɛ, under open ocean conditions are limited. Consequently, our understanding of what chiefly controls dissipation in the open ocean, and its functional form with depth, is poorly constrained. In this study, we report direct open ocean measurements of ɛ from the Air-Sea Interaction Profiler (ASIP) collected during five different cruises in the Atlantic Ocean. We then combine these data with ocean-atmosphere flux measurements and wave information in order to evaluate existing turbulence scaling theories under a diverse set of open ocean conditions. Our results do not support the presence of a "breaking" or a "transition layer," which has been previously suggested. Instead, ɛ decays as |z|-1.29 over the depth interval, which was previously defined as "transition layer," and as |z|-1.15 over the mixing layer. This depth dependency does not significantly vary between nonbreaking or breaking wave conditions. A scaling relationship based on the friction velocity, the wave age, and the significant wave height describes the observations best for daytime conditions. For conditions during which convection is important, it is necessary to take buoyancy forcing into account.

Radiative edge layers in limiter tokamaks

International Nuclear Information System (INIS)

Monier-Garbet, P.

1997-01-01

The characteristics of the highly radiative edge layers produced in the limiter configuration and with an open ergodic divertor are reviewed, with emphasis on the results obtained in TEXTOR and Tore Supra. In these two experiments an impurity injection technique is used to obtain highly radiating homogeneous peripheral layers. This requires that the peripheral radiation capability be maximized, while at the same time avoiding plasma core contamination; it is also necessary to insure the stability of the radiating layer. These physics issues, governing the success of the highly radiative edge scenario, are discussed. (orig.)

Layer-by-layer assembly for biomedical applications in the last decade

Science.gov (United States)

Gentile, P.; Carmagnola, I.; Nardo, T.; Chiono, V.

2015-10-01

In the past two decades, the design and manufacture of nanostructured materials has been of tremendous interest to the scientific community for their application in the biomedical field. Among the available techniques, layer-by-layer (LBL) assembly has attracted considerable attention as a convenient method to fabricate functional coatings. Nowadays, more than 1000 scientific papers are published every year, tens of patents have been deposited and some commercial products based on LBL technology have become commercially available. LBL presents several advantages, such as (1): a precise control of the coating properties; (2) environmentally friendly, mild conditions and low-cost manufacturing; (3) versatility for coating all available surfaces; (4) obtainment of homogeneous film with controlled thickness; and (5) incorporation and controlled release of biomolecules/drugs. This paper critically reviews the scientific challenge of the last 10 years—functionalizing biomaterials by LBL to obtain appropriate properties for biomedical applications, in particular in tissue engineering (TE). The analysis of the state-of-the-art highlights the current techniques and the innovative materials for scaffold and medical device preparation that are opening the way for the preparation of LBL-functionalized substrates capable of modifying their surface properties for modulating cell interaction to improve substitution, repair or enhancement of tissue function.

Layer-by-layer assembly for biomedical applications in the last decade

International Nuclear Information System (INIS)

Gentile, P; Carmagnola, I; Nardo, T; Chiono, V

2015-01-01

In the past two decades, the design and manufacture of nanostructured materials has been of tremendous interest to the scientific community for their application in the biomedical field. Among the available techniques, layer-by-layer (LBL) assembly has attracted considerable attention as a convenient method to fabricate functional coatings. Nowadays, more than 1000 scientific papers are published every year, tens of patents have been deposited and some commercial products based on LBL technology have become commercially available. LBL presents several advantages, such as (1): a precise control of the coating properties; (2) environmentally friendly, mild conditions and low-cost manufacturing; (3) versatility for coating all available surfaces; (4) obtainment of homogeneous film with controlled thickness; and (5) incorporation and controlled release of biomolecules/drugs. This paper critically reviews the scientific challenge of the last 10 years—functionalizing biomaterials by LBL to obtain appropriate properties for biomedical applications, in particular in tissue engineering (TE). The analysis of the state-of-the-art highlights the current techniques and the innovative materials for scaffold and medical device preparation that are opening the way for the preparation of LBL-functionalized substrates capable of modifying their surface properties for modulating cell interaction to improve substitution, repair or enhancement of tissue function. (topical review)

Layer-by-layer assembly for biomedical applications in the last decade.

Science.gov (United States)

Gentile, P; Carmagnola, I; Nardo, T; Chiono, V

2015-10-23

In the past two decades, the design and manufacture of nanostructured materials has been of tremendous interest to the scientific community for their application in the biomedical field. Among the available techniques, layer-by-layer (LBL) assembly has attracted considerable attention as a convenient method to fabricate functional coatings. Nowadays, more than 1000 scientific papers are published every year, tens of patents have been deposited and some commercial products based on LBL technology have become commercially available. LBL presents several advantages, such as (1): a precise control of the coating properties; (2) environmentally friendly, mild conditions and low-cost manufacturing; (3) versatility for coating all available surfaces; (4) obtainment of homogeneous film with controlled thickness; and (5) incorporation and controlled release of biomolecules/drugs. This paper critically reviews the scientific challenge of the last 10 years--functionalizing biomaterials by LBL to obtain appropriate properties for biomedical applications, in particular in tissue engineering (TE). The analysis of the state-of-the-art highlights the current techniques and the innovative materials for scaffold and medical device preparation that are opening the way for the preparation of LBL-functionalized substrates capable of modifying their surface properties for modulating cell interaction to improve substitution, repair or enhancement of tissue function.

Structural Alterations of Segmented Macular Inner Layers in Aquaporin4-Antibody-Positive Optic Neuritis Patients in a Chinese Population.

Directory of Open Access Journals (Sweden)

Chunxia Peng

Full Text Available This study aimed to analyse the structural injury of the peripapillary retinal nerve fibre layer (pRNFL and segmented macular layers in optic neuritis (ON in aquaporin4-antibody (AQP4-Ab seropositivity(AQP4-Ab-positiveON patients and in AQP4-Ab seronegativity (AQP4-Ab-negative ON patients in order to evaluate their correlations with the best-corrected visual acuity (BCVA and the value of the early diagnosis of neuromyelitis optica (NMO.This is a retrospective, cross-sectional and control observational study.In total, 213 ON patients (291 eyes and 50 healthy controls (HC (100 eyes were recruited in this study. According to a serum AQP4-Ab assay, 98 ON patients (132 eyes were grouped as AQP4-Ab-positive ON and 115 ON patients (159 eyes were grouped as AQP4-Ab-negative ON cohorts. All subjects underwent scanning with spectralis optical coherence tomography (OCT and BCVA tests. pRNFL and segmented macular layer measurements were analysed.The pRNFL thickness in AQP4-Ab-positive ON eyes showed a more serious loss during 0-2 months (-27.61μm versus -14.47 μm and ≥6 months (-57.91μm versus -47.19μm when compared with AQP4-Ab-negative ON eyes. AQP4-Ab-positive ON preferentially damaged the nasal lateral pRNFL. The alterations in the macular ganglion cell layer plus the inner plexiform layer (GCIP in AQP4-Ab-positive ON eyes were similar to those in AQP4-Ab-negative ON eyes. AQP4-Ab-positive ON eyes had entirely different injury patterns in the inner nuclear layer (INL compared with AQP4-Ab-negative ON eyes during the first 6 months after the initial ON attack. These differences were as follows: the INL volume of AQP4-Ab-positive ON eyes had a gradual growing trend compared with AQP4-Ab-negative ON eyes, and it increased rapidly during 0-2 months, reached its peak during 2-4 months, and then decreased gradually. The pRNFL and GCIP in AQP4-Ab-positive ON eyes had positive correlations with BCVA. When the pRNFL thickness decreased to 95%CI (50.77�

Synthesis, structure and characterization of two new open-framework gallium phosphite-oxalates of varying dimensionality

International Nuclear Information System (INIS)

Li, Caixia; Huang, Liangliang; Zhou, Mingdong; Xia, Jing; Ma, Hongwei; Zang, Shuliang; Wang, Li

2013-01-01

Using N, N-dimethyl-piperazine as structure directing agent, two new gallium phosphite-oxalates [Ga 2 (HPO 3 ) 2 (H 2 PO 3 ) 2 (C 2 O 4 )](C 6 N 2 H 16 ) (I) and [Ga 2 (HPO 3 ) 2 (H 2 PO 3 )(C 2 O 4 )](C 6 N 2 H 16 ) 0.5 (II) have been synthesized under solvothermal and hydrothermal conditions, respectively and further characterized by powder X-ray diffraction, IR spectroscopy, TGA, ICP-AES and elemental analyses. Single crystal X-ray diffraction reveals that the striking feature of I and II is that they possess the same second building unit (SBU) Ga 2 P 2 constructed from two GaO 6 octahedra and two [HPO 3 2− ] pseudo-pyramids sharing oxygen atoms. However, due to the different connecting fashions of SBUs, [C 2 O 4 2− ] groups and [H 2 PO 3 − ] pseudo-pyramids, the final frameworks of them are distinctly different. Compound I shows 2D layered structures with 8-membered ring (8-MR) windows in the ab plane while compound II presents a 3D open-framework with 8-MR channels along the b axis. - Graphical abstract: Using N, N-dimethyl-piperazine as structure directing agent, two new gallium phosphite-oxalates I showing 2D layered structure and II presenting 3D open-framework have been synthesized under solvothermal and hydrothermal conditions, respectively. - Highlights: • Using N, N-dimethyl-piperazine as structure directing agent, two new gallium phosphite-oxalates have been synthesized under solvothermal and hydrothermal conditions, respectively. • The same second building unit (SBU) is displayed in both compounds. • Compound I shows 2D layered structure with 8-MR windows while compound II presents 3D open-framework with 8-MR channels. • The solvent plays an important role on the formation of microporous compounds

Contact-free sheet resistance determination of large area graphene layers by an open dielectric loaded microwave cavity

International Nuclear Information System (INIS)

Shaforost, O.; Wang, K.; Adabi, M.; Guo, Z.; Hanham, S.; Klein, N.; Goniszewski, S.; Gallop, J.; Hao, L.

2015-01-01

A method for contact-free determination of the sheet resistance of large-area and arbitrary shaped wafers or sheets coated with graphene and other (semi) conducting ultrathin layers is described, which is based on an open dielectric loaded microwave cavity. The sample under test is exposed to the evanescent resonant field outside the cavity. A comparison with a closed cavity configuration revealed that radiation losses have no significant influence of the experimental results. Moreover, the microwave sheet resistance results show good agreement with the dc conductivity determined by four-probe van der Pauw measurements on a set of CVD samples transferred on quartz. As an example of a practical application, correlations between the sheet resistance and deposition conditions for CVD graphene transferred on quartz wafers are described. Our method has a high potential as measurement standard for contact-free sheet resistance measurement and mapping of large area graphene samples

Effects of Anodic Buffer Layer in Top-Illuminated Organic Solar Cell with Silver Electrodes

Directory of Open Access Journals (Sweden)

Tien-Lung Chiu

2013-01-01

Full Text Available An efficient ITO-free top-illuminated organic photovoltaic (TOPV based on small molecular planar heterojunction was achieved by spinning a buffer layer of poly(3,4-ethylenedioxythiophene:poly(styrenesulfonate (PEDOT:PSS, on the Ag-AgOx anode. The PEDOT:PSS thin film separates the active layer far from the Ag anode to prevent metal quenching and redistributes the strong internal optical field toward dissociated interface. The thickness and morphology of this anodic buffer layer are the key factors in determining device performances. The uniform buffer layer contributes a large short-circuit current and open-circuit voltage, benefiting the final power conversion efficiency (PCE. The TOPV device with an optimal PEDOT:PSS thickness of about 30 nm on Ag-AgOx anode exhibits the maximum PCE of 1.49%. It appreciates a 1.37-fold enhancement in PCE over that of TOPV device without buffer layer.

Residual stresses and mechanical properties of Si3N4/SiC multilayered composites with different SiC layers

International Nuclear Information System (INIS)

Liua, S.; Lia, Y.; Chena, P.; Lia, W.; Gaoa, S.; Zhang, B.; Yeb, F.

2017-01-01

The effect of residual stresses on the strength, toughness and work of fracture of Si3N4/SiC multilayered composites with different SiC layers has been investigated. It may be an effective way to design and optimize the mechanical properties of Si3N4/SiC multilayered composites by controlling the properties of SiC layers. Si3N4/SiC multilayered composites with different SiC layers were fabricated by aqueous tape casting and pressureless sintering. Residual stresses were calculated by using ANSYS simulation, the maximum values of tensile and compressive stresses were 553.2MPa and −552.1MPa, respectively. Step-like fracture was observed from the fracture surfaces. Fraction of delamination layers increased with the residual stress, which can improve the reliability of the materials. Tensile residual stress was benefit to improving toughness and work of fracture, but the strength of the composites decreased. [es

Soil heat flux measurements in an open forest

NARCIS (Netherlands)

vanderMeulen, MJW; Klaassen, W; Kiely, G

1996-01-01

The soil surface heat flux in an open oak forest was determined at four locations to account for the heterogeneity of the forest. Soil temperatures and soil water content were measured at several depths and an integration method with three layers was used. The thickness of the bottom layer was

Soil Heat Flux Measurements in an Open Forest

NARCIS (Netherlands)

Meulen, M.W.J. van der; Klaassen, W.

1996-01-01

The soil surface heat flux in an open oak forest was determined at four locations to account for the heterogeneity of the forest. Soil temperatures and soil water content were measured at several depths and an integration method with three layers was used. The thickness of the bottom layer was

Towards a super-strainable paper using the Layer-by-Layer technique.

Science.gov (United States)

Marais, Andrew; Utsel, Simon; Gustafsson, Emil; Wågberg, Lars

2014-01-16

The Layer-by-Layer technique was used to build a polyelectrolyte multilayer on the surface of pulp fibres. The treated fibres were then used to prepare paper sheets and the mechanical properties of these sheets were evaluated as a function of the number of bi-layers on the fibres. Two different systems were studied: polyethyleneimine (PEI)/nanofibrillated cellulose (NFC), and polyallylamine hydrochloride (PAH)/hyaluronic acid (HA). Model experiments using dual polarization interferometry and SiO₂ surfaces showed that the two systems gave different thicknesses for a given number of layers. The outer layer was found to be a key parameter in the PEI/NFC system, whereas it was less important in the PAH/HA system. The mechanical properties of the sheets made from the PAH/HA treated fibres were significantly greater than those made from untreated fibres, reaching 70 Nm/g in tensile index and 6.5% in strain at break. Such a modification could be very useful for 3D forming of paper, opening new perspectives in for example the packaging industry, with a renewable and biodegradable product as a potential substitute for some of the traditional oil-based plastics. Copyright © 2013 Elsevier Ltd. All rights reserved.

Luminescence mechanisms of organic/inorganic hybrid organic light-emitting devices fabricated utilizing a Zn2SiO4:Mn color-conversion layer

International Nuclear Information System (INIS)

Choo, D.C.; Ahn, S.D.; Jung, H.S.; Kim, T.W.; Lee, J.Y.; Park, J.H.; Kwon, M.S.

2010-01-01

Zn 2 SiO 4 :Mn phosphor layers used in this study were synthesized by using the sol-gel method and printed on the glass substrates by using a vehicle solution and a heating process. Organic/inorganic hybrid organic light-emitting devices (OLEDs) utilizing a Zn 2 SiO 4 :Mn color-conversion layer were fabricated. X-ray diffraction data for the synthesized Zn 2 SiO 4 :Mn phosphor films showed that the Zn ions in the phosphor were substituted into Mn ions. The electroluminescence (EL) spectrum of the deep blue OLEDs showed that a dominant peak at 461 nm appeared. The photoluminescence spectrum for the Zn 2 SiO 4 :Mn phosphor layer by using a 470 nm excitation source showed that a dominant peak at 527 nm appeared, which originated from the 4 T 1 - 6 A 1 transitions of Mn ions. The appearance of the peak around 527 nm of the EL spectra for the OLEDs fabricated utilizing a Zn 2 SiO 4 :Mn phosphor layer demonstrated that the emitted blue color from the deep blue OLEDs was converted into a green color due to the existence of the color-conversion layer. The luminescence mechanisms of organic/inorganic hybrid OLEDs fabricated utilizing a Zn 2 SiO 4 :Mn color-conversion layer are described on the basis of the EL and PL spectra.

Young Investigator Proposal, Research Area 7.4 Reactive Chemical Systems: Multifunctional, Bimetallic Nanomaterials Prepared by Atomic Layer Electroless Deposition

Science.gov (United States)

2017-09-30

Report: Young Investigator Proposal, Research Area 7.4 Reactive Chemical Systems: Multifunctional, Bimetallic Nanomaterials Prepared by Atomic Layer ...Chemical Systems: Multifunctional, Bimetallic Nanomaterials Prepared by Atomic Layer Electroless Deposition Report Term: 0-Other Email: pcappillino... Layer Electroless Deposition (ALED, Figure 1) is the ability to tune growth mechanism, hence growth morphology, by altering conditions. In this

Synthesis of Poly(3,4-Ethylenedioxy thiophene)-Poly(Styrene-4-Sulfonate) Composites for Support Fuel Cell Catalyst Layer

International Nuclear Information System (INIS)

Eko Sulistiyono; Murni Handayani

2009-01-01

Synthesis of poly(3,4-ethylenedioxy thiophene)-poly(styrene-4-sulfonate) composites for support fuel cell catalyst layer are synthesis composites which become fuel cell catalyst support so that catalyst has optimal performance. Main function of composites is support platinum particle for application in fuel cell. This article explains the result of composites production process from ( 3,4 Ethylenedioxy thiophene) and Sodium poly( styrene - 4-sulfonate) using two methods Jingning Shan method (method 1) and Zhigang Qi and Peter G.Pickup method (method 2). Analysis of the synthesis results used Scanning Electron Microscopic –Electron Dispersive X – Ray Spectrophotometer (SEM-EDS ). The analysis result show that both methods produce polymer agglomerate into a sponge-like morphology. Composite from method 1 has morphology, pores and proton transport better than composite produced by method 2. (author)

The hydrodynamic dust retention modeling process with a foam layer for open linear dynamic technological systems at construction industry enterprises

Directory of Open Access Journals (Sweden)

Bespalov Vadim

2017-01-01

Full Text Available The physical essence of the reducing air pollution hydrodynamic method by means of the foamy method as the most effective dust retention technology for open long sources at construction industry enterprises is presented in the article. The mathematical description of this technology has been performed, taking into account the physical and chemical properties of the dust and foam bubble, as well as the parameters of the return of dust particles to technological raw material due to various physical mechanisms for their capture. The obtained parametric dependence of dust retention efficiency provides the possibility of its predicted calculation as a resultant parameter for the considering technology, taking into account the interaction of dust with a foam layer.

Inorganic layered double hydroxides as a 4-hexyl resorcinol delivery system for topical applications

CSIR Research Space (South Africa)

Mosangi, Damodar

2016-08-01

Full Text Available In this study, the hydrophobic even skin tone active, 4-hexylresorcinol (HR), was intercalated into a zinc aluminium layered double hydroxide (ZnAl-LDH) by a co-precipitation method and used as a controlled release ingredient in skin care...

Chemically milled alpha-case layer from Ti-6Al-4V alloy investment cast

CSIR Research Space (South Africa)

Mutombo, K

2011-06-01

Full Text Available The as cast Ti6Al4V, obtained after investment casting with yttria stabilized zirconia face-coat, was chemically milled using a mixture of hydrofluoric acid and nitric acid. This process removed completely the alpha-case layer. Lower hardness...

Effect of CuPc layer insertion on the memory performance of CdS nanocomposite diodes

Energy Technology Data Exchange (ETDEWEB)

Tripathi, S.K., E-mail: surya@pu.ac.in; Kaur, Ramneek; Jyoti

2016-09-15

Highlights: • CdS nanocomposite as an active layer investigated for memory device application. • Effect of copper phthalocyanine layer insertion on the memory performance studied. • Bipolar switching behaviour with high ON/OFF ratio ∼1.4 × 10{sup 4}. • Series resistance and interface states dominate the electrical properties of the device. - Abstract: In the present work, semiconductor diodes with CdS nanocomposite as an active layer have been fabricated and investigated for memory device applications. The effect of copper phthalocyanine (CuPc) layer insertion between the bottom electrode and CdS nanocomposite has been studied. I–V characteristics show electrical hysteresis behaviour vital for memory storage application. The as-fabricated devices exhibit bipolar switching behaviour with OFF to ON state transition at positive bias and vice versa. Device with CuPc layer exhibits I{sub ON}/I{sub OFF} ratio ∼ 1.4 × 10{sup 4}. Possible conduction mechanism has been described on the basis of theoretical current conduction models. The frequency dispersion capacitance, series resistance and conductance of the devices have been studied and discussed. At low frequency, the series resistance and the interface states dominate the electrical properties of the device. The results indicate that the multilayered devices open up the possibility of new generation non-volatile memory devices with low cost, high density and stability.

S-Layer Based Bio-Imprinting - Synthetic S-Layer Polymers

Science.gov (United States)

2015-07-09

AFRL-OSR-VA-TR-2015-0161 S-Layer Based Bio- Imprinting - Synthetic S-Layer Polymers Dietmar Pum ZENTRUM FUER NANOBIOTECHNOLOGIE Final Report 07/09...COVERED (From - To)      01-06-2012 to 31-05-2015 4.  TITLE AND SUBTITLE S-Layer Based Bio- Imprinting - Synthetic S-Layer Polymers 5a.  CONTRACT...technology for the fabrication of nano patterned thin film imprints by using functional S-layer protein arrays as templates. The unique feature of

Reduction in spontaneous firing of mouse excitatory layer 4 cortical neurons following visual classical conditioning

Science.gov (United States)

Bekisz, Marek; Shendye, Ninad; Raciborska, Ida; Wróbel, Andrzej; Waleszczyk, Wioletta J.

2017-08-01

The process of learning induces plastic changes in neuronal network of the brain. Our earlier studies on mice showed that classical conditioning in which monocular visual stimulation was paired with an electric shock to the tail enhanced GABA immunoreactivity within layer 4 of the monocular part of the primary visual cortex (V1), contralaterally to the stimulated eye. In the present experiment we investigated whether the same classical conditioning paradigm induces changes of neuronal excitability in this cortical area. Two experimental groups were used: mice that underwent 7-day visual classical conditioning and controls. Patch-clamp whole-cell recordings were performed from ex vivo slices of mouse V1. The slices were perfused with the modified artificial cerebrospinal fluid, the composition of which better mimics the brain interstitial fluid in situ and induces spontaneous activity. The neuronal excitability was characterized by measuring the frequency of spontaneous action potentials. We found that layer 4 star pyramidal cells located in the monocular representation of the "trained" eye in V1 had lower frequency of spontaneous activity in comparison with neurons from the same cortical region of control animals. Weaker spontaneous firing indicates decreased general excitability of star pyramidal neurons within layer 4 of the monocular representation of the "trained" eye in V1. Such effect could result from enhanced inhibitory processes accompanying learning in this cortical area.

Characterization of Tifton 85 bermudagrass haylage with different layers of polyethylene film and storage time.

Science.gov (United States)

Nath, Caroline Daiane; Neres, Marcela Abbado; Scheidt, Kácia Carine; Bersot, Luciano Dos Santos; Sunahara, Samantha Mariana Monteiro; Sarto, Jaqueline Rocha Wobeto; Stangarlin, José Renato; Gomes, Simone Damasceno; Sereno, Mallu Jagnow; Perin, Ana Paula

2018-03-02

The objective was to characterize the fermentative and microbiological profile of Tifton 85 bermudagrass haylage with different layers of polyethylene film and storage time. The experimental design consisted of a randomized block design with four and six wrapping layers (100 and 150 microns in total. respectively) allocated in the main plots, through repeated measures analysis (30, 60, and 90 days of storage) with four replicates. The storage time and number of wrapping layers did not show changes in the population of Clostridium and lactic acid bacteria. A decrease was observed in the enterobacteria population with an increase in the storage period in the two wrapping layers studied. Upon opening of the haylage at 30 days, the population of Bacillus was lower in haylages made with six layers of wrapping (3.63 log colony forming units (CFU) g-1). No growth of Listeria sp. or Salmonella sp. was observed during the experimental period. The fungal genera with greater occurrence were Penicillium sp. and Fusarium sp. The following mycotoxins were not detected: ochratoxin A, fumonisins, and zearalenone. Relative to the organic butyric, propionic, and acetic acids, the haylages presented a low concentration of lactic acid; this may have prevented a drop in the pH, which was high when the silos were opened (5.4). The levels of ammoniacal nitrogen and soluble carbohydrates presented no variation among the number of wrapping layers, with an overall average of 35.55 and 38.04 g kg-1. Tifton 85 bermudagrass haylage wrapped with four and six layers presented adequate fermentation and microbiological characteristics in the evaluated periods.

A new set of K3Fe3(PO4)4·yH2O (0 ≤ y ≤ 1) layered phases obtained by topotactic reactions

Science.gov (United States)

Trad, Khiem; Wattiaux, Alain; Ben Amara, Mongi; Delmas, Claude; Carlier, Dany

2018-06-01

K3Fe3(PO4)4·H2O powder was synthesized by Na+/K+ exchange reaction from Na3Fe3(PO4)4 in aqueous medium. The replacement of the sodium cations by the potassium larger ones and water molecules causes a structural distortion leading to P2/n monoclinic K3Fe3(PO4)4·H2O. This new layered phase was characterized by XRD, Mössbauer spectroscopy and magnetic measurements. The study of its thermal stability reveals that other new layered K3Fe3(PO4)4·yH2O with (0 ≤ y ≤ 1) phases can be stabilized up to 600 °C and finally at higher temperature a new K3Fe3(PO4)4 polymorph with a different structural type is irreversibility formed.

4P-NPD ultra thin-films as efficient exciton blocking layers in DBP/C₇₀ based organic solar cells

DEFF Research Database (Denmark)

Patil, Bhushan Ramesh; Liu, Yiming; Qamar, Talha

2017-01-01

Exciton blocking effects from ultra thin layers of N,N'-di-1-naphthalenyl-N,N'-diphenyl [1,1':4',1'':4'',1'''-quaterphenyl]-4,4'''-diamine (4P-NPD) was investigated in small molecule based inverted Organic Solar Cells (OSCs) using Tetraphenyldibenzoperiflanthene (DBP) as the electron donor material...... and fullerene (C70) as the electron acceptor material. The short-circuit current density (Jsc) and PCE of the optimized OSCs with 0.7 nm thick 4P-NPD were approx. 16 % and 24 % higher, respectively, compared to reference devices without exciton blocking layers. Drift diffusion based device modeling...... was conducted to model the full Current density – Voltage (JV) characteristics and EQE spectrum of the OSCs, and photoluminescence measurements was conducted to investigate the exciton blocking effects with increasing thicknesses of the 4P-NPD layer. Importantly, coupled optical and electrical modeling studies...

Synthesis of Polysiloxanes In Microemulsion Via ring opening of D4

Directory of Open Access Journals (Sweden)

Liu Jiesheng

2016-07-01

Full Text Available Polydimethylsiloxane (PDMS has been synthesized by ring-opening polymerization of octamethylcyclotetrasiloxane (D4 in microemulsion with acidic catalyst. The structure and properties of microemulsion were characterized by Transmission Electron Microscopy (TEM, Fourier Transform Infrared Spectroscopy (FT-IR, Photo Correlation Spectroscopy (PCS. The effect of the variation in pH value, amount of catalyst, emulsifier and monomer dropping rate on the properties of microemulsion were investigated and discussed. The results showed that the particle size of the latex becomes smaller, and the distribution size becomes wider with increasing the content of catalyst and emulsifier. When pH value changed, the reaction rate of ring-opening of D4 was faster with strong acid than that under the weak acid condition. The emulsification of 2 % OP-10 (Alkylphenol polyoxyethylene ether and 3.0% DBSA (Dodecyl benzenesulfonic acid reached to equilibrium in microemulsion. As the amount of OP-10 increases, the size of particles lowered and their corresponding  distribution widened. It is observed that emulsifier (OP-10 does not affect the transparency of the microemulsion in the case of the application of DBSA. As the monomer dropping time increased, the grain size diminished and the size distribution widened. PCS results showed that the smallest particle size was around 20nm. Taking into account of the stability of the microemulsions, the dropping time of the monomer was around 30 min.

Hybrid inorganic–organic superlattice structures with atomic layer deposition/molecular layer deposition

Energy Technology Data Exchange (ETDEWEB)

Tynell, Tommi; Yamauchi, Hisao; Karppinen, Maarit, E-mail: maarit.karppinen@aalto.fi [Department of Chemistry, Aalto University, FI-00076 Aalto (Finland)

2014-01-15

A combination of the atomic layer deposition (ALD) and molecular layer deposition (MLD) techniques is successfully employed to fabricate thin films incorporating superlattice structures that consist of single layers of organic molecules between thicker layers of ZnO. Diethyl zinc and water are used as precursors for the deposition of ZnO by ALD, while three different organic precursors are investigated for the MLD part: hydroquinone, 4-aminophenol and 4,4′-oxydianiline. The successful superlattice formation with all the organic precursors is verified through x-ray reflectivity studies. The effects of the interspersed organic layers/superlattice structure on the electrical and thermoelectric properties of ZnO are investigated through resistivity and Seebeck coefficient measurements at room temperature. The results suggest an increase in carrier concentration for small concentrations of organic layers, while higher concentrations seem to lead to rather large reductions in carrier concentration.

Patchwork-Type Spontaneous Activity in Neonatal Barrel Cortex Layer 4 Transmitted via Thalamocortical Projections

Directory of Open Access Journals (Sweden)

Hidenobu Mizuno

2018-01-01

Full Text Available Summary: Establishment of precise neuronal connectivity in the neocortex relies on activity-dependent circuit reorganization during postnatal development; however, the nature of cortical activity during this period remains largely unknown. Using two-photon calcium imaging of the barrel cortex in vivo during the first postnatal week, we reveal that layer 4 (L4 neurons within the same barrel fire synchronously in the absence of peripheral stimulation, creating a “patchwork” pattern of spontaneous activity corresponding to the barrel map. By generating transgenic mice expressing GCaMP6s in thalamocortical axons, we show that thalamocortical axons also demonstrate the spontaneous patchwork activity pattern. Patchwork activity is diminished by peripheral anesthesia but is mostly independent of self-generated whisker movements. The patchwork activity pattern largely disappeared during postnatal week 2, as even L4 neurons within the same barrel tended to fire asynchronously. This spontaneous L4 activity pattern has features suitable for thalamocortical (TC circuit refinement in the neonatal barrel cortex. : By two-photon calcium imaging of layer 4 neurons and thalamocortical axon terminals in neonatal mouse barrel cortex, Mizuno et al. find a patchwork-like spontaneous activity pattern corresponding to the barrel map, which may be important for thalamocortical circuit maturation. Keywords: activity-dependent development, spontaneous activity, synchronized activity, barrel cortex, thalamocortical axons, neonates, in vivo calcium imaging, awake, single-cell labeling, whisker monitoring

Novel Electrospun Dual-Layered Composite Nanofibrous Membrane Endowed with Electricity-Magnetism Bifunctionality at One Layer and Photoluminescence at the Other Layer.

Science.gov (United States)

Wang, Zijiao; Ma, Qianli; Dong, Xiangting; Li, Dan; Xi, Xue; Yu, Wensheng; Wang, Jinxian; Liu, Guixia

2016-10-05

Dual-layered composite nanofibrous membrane equipped with electrical conduction, magnetism and photoluminescence trifunctionality is constructed via electrospinning. The composite membrane consists of a polyaniline (PANI)/Fe 3 O 4 nanoparticles (NPs)/polyacrylonitrile (PAN) tuned electrical-magnetic bifunctional nanofibrous layer at one side and a Eu(TTA) 3 (TPPO) 2 /polyvinylpyrrolidone (PVP) photoluminescent nanofibrous layer at the other side, and the two layers are tightly combined face-to-face together into the novel dual-layered composite membrane with trifunctionality. The electric conductivity and magnetism of electrical-magnetic bifunctionality can be respectively tunable via modulating the respective PANI and Fe 3 O 4 NPs contents, and the highest electric conductivity approaches the order of 1 × 10 -2 S cm -1 . Predominant red emission at 615 nm can be obviously observed in the photoluminescent layer under 366 nm excitation. Moreover, the luminescent intensity of photoluminescent layer is almost unaffected by the electrical-magnetic bifunctional layer because of the fact that the photoluminescent materials have been successfully isolated from dark-colored PANI and Fe 3 O 4 NPs. The novel dual-layered composite nanofibrous membrane with trifunctionality has potentials in many fields. Furthermore, the design philosophy and fabrication method for the dual-layered multifunctional membrane provide a new and facile strategy toward other membranes with multifunctionality.

Three new d10 transition metal selenites containing PO4 tetrahedron: Cd7(HPO4)2(PO4)2(SeO3)2, Cd6(PO4)1.34(SeO3)4.66 and Zn3(HPO4)(SeO3)2(H2O)

Science.gov (United States)

Ma, Yun-Xiang; Gong, Ya-Ping; Hu, Chun-li; Mao, Jiang-Gao; Kong, Fang

2018-06-01

Three new d10 transition metal selenites containing PO4 tetrahedron, namely, Cd7(HPO4)2(PO4)2(SeO3)2 (1), Cd6(PO4)1.34(SeO3)4.66 (2) and Zn3(HPO4)(SeO3)2(H2O) (3), have been synthesized by hydrothermal reaction. They feature three different structural types. Compound 1 exhibits a novel 3D network composed of 3D cadmium selenite open framework with phosphate groups filled in the 1D helical tunnels. The structure of compound 2 displays a new 3D framework consisted of 2D cadmium oxide layers bridged by SeO3 and PO4 groups. Compound 3 is isostructural with the reported solids of Co3(SeO3)3-x(PO3OH)x(H2O) when x is equal to 1.0. Its structure could be viewed as a 3D zinc oxide open skeleton with SeO3 and HPO4 polyhedra attached on the wall of the tunnels. They represent the only examples in metal selenite phosphates in addition to the above cobalt compounds. Optical diffuse reflectance spectra revealed that these solids are insulators, which are consistent with the results of band structure computations based on DFT algorithm.

Magnetic studies on Layered solid solution Lix(Ni0.4Mn0.6)2-xO2

Science.gov (United States)

Nakao, K.; Nakamura, T.; Yamada, Y.; Koshiba, N.

2011-05-01

Lix(Ni0.4Mn0.6)2-xO2 (1.09hydroxide as raw materials. All the compounds have a layered rock-salt structure, and the cation mixing degree (Ni2+ occupancy in the Li-layer) decreases with an increase in x. From the low-temperature magnetic measurement, they all have negative Weiss temperature and spontaneous magnetization, that is, they are ferromagnetic materials. Both the Curie temperature and the spontaneous magnetization at 4.2K decrease with an increase in x. These magnetic variations are attributed to the lowering of the cation mixing degree: the magnetic interaction network turns to two-dimensional one with the loss of the inert-layer coupling. These situations may be considered semi-quantitatively using the ferromagnetic cluster model. Additionally, the cation mixing degree has an influence on their electrochemical properties such as cycle fading and rate capability.

Exoelectron emission from surface layer of Li2B4O7 glass ceramics

International Nuclear Information System (INIS)

Kawamoto, Takamichi; Katsube, Shizuko; Yanagisawa, Hideo; Kikuchi, Riichi; Kawanishi, Masaharu.

1984-01-01

The thermally stimulated exoelectron emission (TESS) of Li 2 B 4 O 7 glass ceramics was investigated for its application to the dosimetric use. It has been found the TSEE glow patterns of Li 2 B 4 O 7 glass ceramics and of the thin layer of LiF evaporated on Li 2 B 4 O 7 glass ceramics depend on the kind of radiations irradiated. The TSEE glow pattern of the duplicated structure sample indicated a possibility of determining the dose of each kind of radiation separately in the mixed radiation field. (author)

The open-ocean sensible heat flux and its significance for Arctic boundary layer mixing during early fall

Science.gov (United States)

Ganeshan, Manisha; Wu, Dong L.

2016-10-01

The increasing ice-free area during late summer has transformed the Arctic to a climate system with more dynamic boundary layer (BL) clouds and seasonal sea ice growth. The open-ocean sensible heat flux, a crucial mechanism of excessive ocean heat loss to the atmosphere during the fall freeze season, is speculated to play an important role in the recently observed cloud cover increase and BL instability. However, lack of observations and understanding of the resilience of the proposed mechanisms, especially in relation to meteorological and interannual variability, has left a poorly constrained BL parameterization scheme in Arctic climate models. In this study, we use multi-year Japanese cruise-ship observations from R/V Mirai over the open Arctic Ocean to characterize the surface sensible heat flux (SSHF) during early fall and investigate its contribution to BL turbulence. It is found that mixing by SSHF is favored during episodes of high surface wind speed and is also influenced by the prevailing cloud regime. The deepest BLs and maximum ocean-atmosphere temperature difference are observed during cold air advection (associated with the stratocumulus regime), yet, contrary to previous speculation, the efficiency of sensible heat exchange is low. On the other hand, the SSHF contributes significantly to BL mixing during the uplift (low pressure) followed by the highly stable (stratus) regime. Overall, it can explain ˜ 10 % of the open-ocean BL height variability, whereas cloud-driven (moisture and radiative) mechanisms appear to be the other dominant source of convective turbulence. Nevertheless, there is strong interannual variability in the relationship between the SSHF and the BL height which can be intensified by the changing occurrence of Arctic climate patterns, such as positive surface wind speed anomalies and more frequent conditions of uplift. This study highlights the need for comprehensive BL observations like the R/V Mirai for better understanding and

The open-ocean sensible heat flux and its significance for Arctic boundary layer mixing during early fall

Directory of Open Access Journals (Sweden)

M. Ganeshan

2016-10-01

Full Text Available The increasing ice-free area during late summer has transformed the Arctic to a climate system with more dynamic boundary layer (BL clouds and seasonal sea ice growth. The open-ocean sensible heat flux, a crucial mechanism of excessive ocean heat loss to the atmosphere during the fall freeze season, is speculated to play an important role in the recently observed cloud cover increase and BL instability. However, lack of observations and understanding of the resilience of the proposed mechanisms, especially in relation to meteorological and interannual variability, has left a poorly constrained BL parameterization scheme in Arctic climate models. In this study, we use multi-year Japanese cruise-ship observations from R/V Mirai over the open Arctic Ocean to characterize the surface sensible heat flux (SSHF during early fall and investigate its contribution to BL turbulence. It is found that mixing by SSHF is favored during episodes of high surface wind speed and is also influenced by the prevailing cloud regime. The deepest BLs and maximum ocean–atmosphere temperature difference are observed during cold air advection (associated with the stratocumulus regime, yet, contrary to previous speculation, the efficiency of sensible heat exchange is low. On the other hand, the SSHF contributes significantly to BL mixing during the uplift (low pressure followed by the highly stable (stratus regime. Overall, it can explain  ∼  10 % of the open-ocean BL height variability, whereas cloud-driven (moisture and radiative mechanisms appear to be the other dominant source of convective turbulence. Nevertheless, there is strong interannual variability in the relationship between the SSHF and the BL height which can be intensified by the changing occurrence of Arctic climate patterns, such as positive surface wind speed anomalies and more frequent conditions of uplift. This study highlights the need for comprehensive BL observations like the R/V Mirai for

The Open-Ocean Sensible Heat Flux and Its Significance for Arctic Boundary Layer Mixing During Early Fall

Science.gov (United States)

Ganeshan, Manisha; Wu, Dongliang

2016-01-01

The increasing ice-free area during late summer has transformed the Arctic to a climate system with more dynamic boundary layer (BL) clouds and seasonal sea ice growth. The open-ocean sensible heat flux, a crucial mechanism of excessive ocean heat loss to the atmosphere during the fall freeze season, is speculated to play an important role in the recently observed cloud cover increase and BL instability. However, lack of observations and understanding of the resilience of the proposed mechanisms, especially in relation to meteorological and interannual variability, has left a poorly constrained BL parameterization scheme in Arctic climate models. In this study, we use multiyear Japanese cruise-ship observations from RV Mirai over the open Arctic Ocean to characterize the surface sensible heat flux (SSHF) during early fall and investigate its contribution to BL turbulence. It is found that mixing by SSHF is favored during episodes of high surface wind speed and is also influenced by the prevailing cloud regime. The deepest BLs and maximum ocean-atmosphere temperature difference are observed during cold air advection (associated with the stratocumulus regime), yet, contrary to previous speculation, the efficiency of sensible heat exchange is low. On the other hand, the SSHF contributes significantly to BL mixing during the uplift (low pressure) followed by the highly stable (stratus) regime. Overall, it can explain 10 of the open ocean BL height variability, whereas cloud-driven (moisture and radiative) mechanisms appear to be the other dominant source of convective turbulence. Nevertheless, there is strong interannual variability in the relationship between the SSHF and the BL height which can be intensified by the changing occurrence of Arctic climate patterns, such as positive surface wind speed anomalies and more frequent conditions of uplift. This study highlights the need for comprehensive BL observations like the RV Mirai for better understanding and

Linked Data: Forming Partnerships at the Data Layer

Science.gov (United States)

Shepherd, A.; Chandler, C. L.; Arko, R. A.; Jones, M. B.; Hitzler, P.; Janowicz, K.; Krisnadhi, A.; Schildhauer, M.; Fils, D.; Narock, T.; Groman, R. C.; O'Brien, M.; Patton, E. W.; Kinkade, D.; Rauch, S.

2015-12-01

The challenges presented by big data are straining data management software architectures of the past. For smaller existing data facilities, the technical refactoring of software layers become costly to scale across the big data landscape. In response to these challenges, data facilities will need partnerships with external entities for improved solutions to perform tasks such as data cataloging, discovery and reuse, and data integration and processing with provenance. At its surface, the concept of linked open data suggests an uncalculated altruism. Yet, in his concept of five star open data, Tim Berners-Lee explains the strategic costs and benefits of deploying linked open data from the perspective of its consumer and producer - a data partnership. The Biological and Chemical Oceanography Data Management Office (BCO-DMO) addresses some of the emerging needs of its research community by partnering with groups doing complementary work and linking their respective data layers using linked open data principles. Examples will show how these links, explicit manifestations of partnerships, reduce technical debt and provide a swift flexibility for future considerations.

GRASS GIS: The first Open Source Temporal GIS

Science.gov (United States)

Gebbert, Sören; Leppelt, Thomas

2015-04-01

GRASS GIS is a full featured, general purpose Open Source geographic information system (GIS) with raster, 3D raster and vector processing support[1]. Recently, time was introduced as a new dimension that transformed GRASS GIS into the first Open Source temporal GIS with comprehensive spatio-temporal analysis, processing and visualization capabilities[2]. New spatio-temporal data types were introduced in GRASS GIS version 7, to manage raster, 3D raster and vector time series. These new data types are called space time datasets. They are designed to efficiently handle hundreds of thousands of time stamped raster, 3D raster and vector map layers of any size. Time stamps can be defined as time intervals or time instances in Gregorian calendar time or relative time. Space time datasets are simplifying the processing and analysis of large time series in GRASS GIS, since these new data types are used as input and output parameter in temporal modules. The handling of space time datasets is therefore equal to the handling of raster, 3D raster and vector map layers in GRASS GIS. A new dedicated Python library, the GRASS GIS Temporal Framework, was designed to implement the spatio-temporal data types and their management. The framework provides the functionality to efficiently handle hundreds of thousands of time stamped map layers and their spatio-temporal topological relations. The framework supports reasoning based on the temporal granularity of space time datasets as well as their temporal topology. It was designed in conjunction with the PyGRASS [3] library to support parallel processing of large datasets, that has a long tradition in GRASS GIS [4,5]. We will present a subset of more than 40 temporal modules that were implemented based on the GRASS GIS Temporal Framework, PyGRASS and the GRASS GIS Python scripting library. These modules provide a comprehensive temporal GIS tool set. The functionality range from space time dataset and time stamped map layer management

Topotactic insertion of lithium in the layered structure Li4VO(PO4)2: The tunnel structure Li5VO(PO4)2

International Nuclear Information System (INIS)

Satya Kishore, M.; Pralong, V.; Caignaert, V.; Malo, S.; Hebert, S.; Varadaraju, U.V.; Raveau, B.

2008-01-01

A new V(III) lithium phosphate Li 5 VO(PO 4 ) 2 has been synthesized by electrochemical insertion of lithium into Li 4 VO(PO 4 ) 2 . This phase, which crystallizes in the space group I4/mcm, exhibits a tunnel structure closely related to the layered structure of Li 4 VO(PO 4 ) 2 and to the tunnel structure of VO(H 2 PO 4 ) 2 . The topotactic reactions that take place during lithium exchange and intercalation, starting from VO(H 2 PO 4 ) 2 and going to the final phase Li 5 VO(PO 4 ) 2 are explained on the basis of the flexible coordinations of V 4+ and V 3+ species. The electrochemical and magnetic properties of this new phase are also presented and explained on the basis of the structure dimensionality. - Graphical abstract: Electrochemical synthesis of a new 3D V(III) lithium phosphate, Li 5 VO(PO 4 ) 2 . Starting from the 2D Li 4 VO(PO 4 ) 2 , the topotactic reaction that take place during lithium intercalation is explained on the basis of the flexible coordinations of V 4+ and V 3+ species

Parallel inhomogeneity and the Alfven resonance. 1: Open field lines

Science.gov (United States)

Hansen, P. J.; Harrold, B. G.

1994-01-01

In light of a recent demonstration of the general nonexistence of a singularity at the Alfven resonance in cold, ideal, linearized magnetohydrodynamics, we examine the effect of a small density gradient parallel to uniform, open ambient magnetic field lines. To lowest order, energy deposition is quantitatively unaffected but occurs continuously over a thickened layer. This effect is illustrated in a numerical analysis of a plasma sheet boundary layer model with perfectly absorbing boundary conditions. Consequences of the results are discussed, both for the open field line approximation and for the ensuing closed field line analysis.

Increasing Flight Software Reuse with OpenSatKit

Science.gov (United States)

McComas, David C.

2018-01-01

In January 2015 the NASA Goddard Space Flight Center (GSFC) released the Core Flight System (cFS) as open source under the NASA Open Source Agreement (NOSA) license. The cFS is based on flight software (FSW) developed for 12 spacecraft spanning nearly two decades of effort and it can provide about a third of the FSW functionality for a low-earth orbiting scientific spacecraft. The cFS is a FSW framework that is portable, configurable, and extendable using a product line deployment model. However, the components are maintained separately so the user must configure, integrate, and deploy them as a cohesive functional system. This can be very challenging especially for organizations such as universities building cubesats that have minimal experience developing FSW. Supporting universities was one of the primary motivators for releasing the cFS under NOSA. This paper describes the OpenSatKit that was developed to address the cFS deployment challenges and to serve as a cFS training platform for new users. It provides a fully functional out-of-the box software system that includes NASA's cFS, Ball Aerospace's command and control system COSMOS, and a NASA dynamic simulator called 42. The kit is freely available since all of the components have been released as open source. The kit runs on a Linux platform, includes 8 cFS applications, several kit-specific applications, and built in demos illustrating how to use key application features. It also includes the software necessary to port the cFS to a Raspberry Pi and instructions for configuring COSMOS to communicate with the target. All of the demos and test scripts can be rerun unchanged with the cFS running on the Raspberry Pi. The cFS uses a 3-tiered layered architecture including a platform abstraction layer, a Core Flight Executive (cFE) middle layer, and an application layer. Similar to smart phones, the cFS application layer is the key architectural feature for users to extend the FSW functionality to meet their

RANS Modeling of Stably Stratified Turbulent Boundary Layer Flows in OpenFOAM®

Directory of Open Access Journals (Sweden)

Wilson Jordan M.

2015-01-01

Full Text Available Quantifying mixing processes relating to the transport of heat, momentum, and scalar quantities of stably stratified turbulent geophysical flows remains a substantial task. In a stably stratified flow, such as the stable atmospheric boundary layer (SABL, buoyancy forces have a significant impact on the flow characteristics. This study investigates constant and stability-dependent turbulent Prandtl number (Prt formulations linking the turbulent viscosity (νt and diffusivity (κt for modeling applications of boundary layer flows. Numerical simulations of plane Couette flow and pressure-driven channel flow are performed using the Reynolds-averaged Navier-Stokes (RANS framework with the standard k-ε turbulence model. Results are compared with DNS data to evaluate model efficacy for predicting mean velocity and density fields. In channel flow simulations, a Prandtl number formulation for wall-bounded flows is introduced to alleviate overmixing of the mean density field. This research reveals that appropriate specification of Prt can improve predictions of stably stratified turbulent boundary layer flows.

Voc enhancement of a solar cell with doped Li+-PbS as the active layer

Science.gov (United States)

Chávez Portillo, M.; Alvarado Pulido, J.; Gallardo Hernández, S.; Soto Cruz, B. S.; Alcántara Iniesta, S.; Gutiérrez Pérez, R.; Portillo Moreno, O.

2018-06-01

In this report, we investigate the fabrication of solar cells obtained by chemical bath technique, based on CdS as window layer and PbS and PbS-Li+-doped as the active layer. We report open-circuit-voltage Voc values of ∼392 meV for PbS and ∼630 meV for PbSLi+-doped, a remarkable enhanced in the open circuit voltage is shown for solar cells with doped active layer. Li+ ion passivate the dangling bonds in PbS-metal layer interface in consequence reducing the recombination centers.

The Surface Layer Homology Domain-Containing Proteins of Alkaliphilic Bacillus pseudofirmus OF4 Play an Important Role in Alkaline Adaptation via Peptidoglycan Synthesis.

Science.gov (United States)

Fujinami, Shun; Ito, Masahiro

2018-01-01

It is well known that the Na + cycle and the cell wall are essential for alkaline adaptation of Na + -dependent alkaliphilic Bacillus species. In Bacillus pseudofirmus OF4, surface layer protein A (SlpA), the most abundant protein in the surface layer (S-layer) of the cell wall, is involved in alkaline adaptation, especially under low Na + concentrations. The presence of a large number of genes that encode S-layer homology (SLH) domain-containing proteins has been suggested from the genome sequence of B. pseudofirmus OF4. However, other than SlpA, the functions of SLH domain-containing proteins are not well known. Therefore, a deletion mutant of the csaB gene, required for the retention of SLH domain-containing proteins on the cell wall, was constructed to investigate its physiological properties. The csaB mutant strain of B. pseudofirmus OF4 had a chained morphology and alkaline sensitivity even under a 230 mM Na + concentration at which there is no growth difference between the parental strain and the slpA mutant strain. Ultra-thin section transmission electron microscopy showed that a csaB mutant strain lacked an S-layer part, and its peptidoglycan (PG) layer was disturbed. The slpA mutant strain also lacked an S-layer part, although its PG layer was not disturbed. These results suggested that the surface layer homology domain-containing proteins of B. pseudofirmus OF4 play an important role in alkaline adaptation via peptidoglycan synthesis.

(C6H16N2)Zn3(HPO3)4H2O: a new layered zinc phosphite templated by diprotonated trans-1,4-diaminocyclohexane

International Nuclear Information System (INIS)

Wang Yu; Yu Jihong; Li Yi; Du Yu; Xu Ruren; Ye Ling

2003-01-01

Employing trans-1,4-diaminocyclohexane (trans-1,4-DACH) as a template, a new two-dimensional layered zinc phosphite (C 6 H 16 N 2 )Zn 3 (HPO 3 ) 4 H 2 O (1) has been prepared hydrothermally. Single-crystal X-ray diffraction analysis shows that it crystallizes in the monoclinic space group P2 1 /n with a=10.458(2) A, b=14.720(3) A, c=13.079(3) A, β=97.93(3) deg. , V=1994.1(7) A 3 , Z=4, R 1 =0.0349 (I>2σ(I)) and wR 2 =0.0605 (all data). The inorganic layer is built up by alternation of ZnO 4 tetrahedra and HPO 3 pseudo pyramids forming a 4.6.8-net. The sheet is featured by a series of capped six-membered rings. The diprotonated trans-1,4-DACH molecules reside in the interlayer region and interact with the inorganic network through H-bonds

Two-Dimensional Layered Oxide Structures Tailored by Self-Assembled Layer Stacking via Interfacial Strain.

Science.gov (United States)

Zhang, Wenrui; Li, Mingtao; Chen, Aiping; Li, Leigang; Zhu, Yuanyuan; Xia, Zhenhai; Lu, Ping; Boullay, Philippe; Wu, Lijun; Zhu, Yimei; MacManus-Driscoll, Judith L; Jia, Quanxi; Zhou, Honghui; Narayan, Jagdish; Zhang, Xinghang; Wang, Haiyan

2016-07-06

Study of layered complex oxides emerge as one of leading topics in fundamental materials science because of the strong interplay among intrinsic charge, spin, orbital, and lattice. As a fundamental basis of heteroepitaxial thin film growth, interfacial strain can be used to design materials that exhibit new phenomena beyond their conventional forms. Here, we report a strain-driven self-assembly of bismuth-based supercell (SC) with a two-dimensional (2D) layered structure. With combined experimental analysis and first-principles calculations, we investigated the full SC structure and elucidated the fundamental growth mechanism achieved by the strain-enabled self-assembled atomic layer stacking. The unique SC structure exhibits room-temperature ferroelectricity, enhanced magnetic responses, and a distinct optical bandgap from the conventional double perovskite structure. This study reveals the important role of interfacial strain modulation and atomic rearrangement in self-assembling a layered singe-phase multiferroic thin film, which opens up a promising avenue in the search for and design of novel 2D layered complex oxides with enormous promise.

Synthesis, structure and photoluminescence properties of amine-templated open-framework bismuth sulfates

Science.gov (United States)

Marri, Subba R.; Behera, J. N.

2014-02-01

Two organically-templated bismuth sulfates of the compositions, [C6N2H14] [Bi(SO4)2(NO3)], (1) and [C4N2H12]4[Bi4(SO4)10(H2O)4], (2), with open architecture have been synthesized and their structures determined by single crystal X-ray diffraction. 1 has a corrugated layered structure with 8-membered aperture wherein the SO4 tetrahedra and the BiO8 polyhedra join together to form (4, 4) net sheets of the metal centers while 2 has a three-dimensional structure possessing 8- and 12-membered channels. Both the compounds show good fluorescence properties exhibiting blue luminescence. Time-resolved fluorescence behavior of 1 and 2 shows mean fluorescence life time of 0.9 and 1.0 ns, respectively.

Structural and electronic properties of the transition layer at the SiO2/4H-SiC interface

Directory of Open Access Journals (Sweden)

Wenbo Li

2015-01-01

Full Text Available Using first-principles methods, we generate an amorphous SiO2/4H-SiC interface with a transition layer. Based this interface model, we investigate the structural and electronic properties of the interfacial transition layer. The calculated Si 2p core-level shifts for this interface are comparable to the experimental data, indicating that various SiCxOy species should be present in this interface transition layer. The analysis of the electronic structures reveals that the tetrahedral SiCxOy structures cannot introduce any of the defect states at the interface. Interestingly, our transition layer also includes a C-C=C trimer and SiO5 configurations, which lead to the generation of interface states. The accurate positions of Kohn-Sham energy levels associated with these defects are further calculated within the hybrid functional scheme. The Kohn-Sham energy levels of the carbon trimer and SiO5 configurations are located near the conduction and valence band of bulk 4H-SiC, respectively. The result indicates that the carbon trimer occurred in the transition layer may be a possible origin of near interface traps. These findings provide novel insight into the structural and electronic properties of the realistic SiO2/SiC interface.

0.4-1.2 GHz hybrid Al-CFRP open-boundary quad-ridge horn

DEFF Research Database (Denmark)

Kim, Oleksiy S.; Pivnenko, Sergey; Breinbjerg, Olav

2011-01-01

We present a 0.4-1.2 GHz open-boundary quad-ridge horn to be used as a wide-band probe at the DTU-ESA Spherical Near-Field Antenna Test Facility at the Technical University of Denmark (DTU). Due to adopted hybrid Al-CFRP fabrication technology, the weight of the probe is reduced by a factor of 2...

Correlation between peripapillary retinal nerve fiber layer thickness and fundus autofluorescence in primary open-angle glaucoma

Directory of Open Access Journals (Sweden)

Reznicek L

2013-09-01

Full Text Available Lukas Reznicek,* Florian Seidensticker,* Thomas Mann, Irene Hübert, Alexandra Buerger, Christos Haritoglou, Aljoscha S Neubauer, Anselm Kampik, Christoph Hirneiss, Marcus Kernt Department of Ophthalmology, Ludwig-Maximilians-University, Munich, Germany *These authors contributed equally to this work Purpose: To investigate the relationship between retinal nerve fiber layer (RNFL thickness and retinal pigment epithelium alterations in patients with advanced glaucomatous visual field defects. Methods: A consecutive, prospective series of 82 study eyes with primary open-angle glaucoma and advanced glaucomatous visual field defects were included in this study. All study participants underwent a full ophthalmic examination followed by visual field testing with standard automated perimetry as well as spectral-domain optical coherence tomography (SD-OCT for peripapillary RNFL thickness and Optos wide-field fundus autofluorescence (FAF images. A pattern grid with corresponding locations between functional visual field sectors and structural peripapillary RNFL thickness was aligned to the FAF images at corresponding location. Mean FAF intensity (range: 0 = black and 255 = white of each evaluated sector (superotemporal, temporal, inferotemporal, inferonasal, nasal, superonasal was correlated with the corresponding peripapillary RNFL thickness obtained with SD-OCT. Results: Correlation analyses between sectoral RNFL thickness and standardized FAF intensity in the corresponding topographic retina segments revealed partly significant correlations with correlation coefficients ranging between 0.004 and 0.376 and were statistically significant in the temporal inferior central field (r = 0.324, P = 0.036 and the nasal field (r = 0.376, P = 0.014. Conclusion: Retinal pigment epithelium abnormalities correlate with corresponding peripapillary RNFL damage, especially in the temporal inferior sector of patients with advanced glaucomatous visual field defects. A

Magnetic studies on Layered solid solution Lix(Ni0.4Mn0.6)2-xO2

International Nuclear Information System (INIS)

Nakao, K; Nakamura, T; Yamada, Y; Koshiba, N

2011-01-01

Li x (Ni 0.4 Mn 0.6 ) 2-x O 2 (1.09≤x≤1.23) were prepared by the solid-state reaction using LiOH and coprecipitated mixed hydroxide as raw materials. All the compounds have a layered rock-salt structure, and the cation mixing degree (Ni 2+ occupancy in the Li-layer) decreases with an increase in x. From the low-temperature magnetic measurement, they all have negative Weiss temperature and spontaneous magnetization, that is, they are ferromagnetic materials. Both the Curie temperature and the spontaneous magnetization at 4.2K decrease with an increase in x. These magnetic variations are attributed to the lowering of the cation mixing degree: the magnetic interaction network turns to two-dimensional one with the loss of the inert-layer coupling. These situations may be considered semi-quantitatively using the ferromagnetic cluster model. Additionally, the cation mixing degree has an influence on their electrochemical properties such as cycle fading and rate capability.

High-stability Ti{sup 4+} precursor for the TiO{sub 2} compact layer of dye-sensitized solar cells

Energy Technology Data Exchange (ETDEWEB)

Yi, Qinghua; Cong, Shan; Wang, Hao; Wang, Yun; Dai, Xiao; Zhao, Jie; Sun, Yinghui; Lou, Yanhui; Zou, Guifu, E-mail: zouguifu@suda.edu.cn

2015-11-30

Graphical abstract: - Highlights: • We developed an aqueous polymer-assisted deposition method to improve the chemical stability of the TiCl{sub 4} aqueous solution. • The Ti{sup 4+} is encapsulated by the polymer can maintain their initial performances for several months. • The film is dense, smooth and uniform, preparing by this method. • The power conversion efficiency of the DSSC based on P-TiO{sub 2} compact film is about 12.5% higher than that based on H-TiO{sub 2}. - Abstract: A compact layer (blocking layer) can effectively block the direct contact between the fluorine-doped tin oxide (FTO) glass substrate and electrolyte in dye-sensitized solar cells (DSSCs). The TiCl{sub 4} hydrolysis has been widely adopted for preparing the TiO{sub 2} compact layer (H-TiO{sub 2}). However, the TiCl{sub 4} aqueous solution is unstable for its high reactivity. To improve the chemical stability of TiCl{sub 4} aqueous solution, the Ti{sup 4+} is encapsulated by the polymer, polyethyleneimine (PEI). Experimentals show that the Ti-PEI precursor solution can maintain their initial performances for several months. The resulting TiO{sub 2} film (P-TiO{sub 2}) grown by the Ti-PEI precursor is dense, smooth and uniform without any visible and detectable cracks or voids. The P-TiO{sub 2} compact layer is even denser than the H-TiO{sub 2} compact layer, suggesting reducing the electron recombination and prolonging the electron lifetime in dye-sensitized solar cells. Indeed, the electron lifetime of the DSSC based on the P-TiO{sub 2} is 13.15 ms, which is longer than the 10.83 ms based on H-TiO{sub 2}. Meanwhile, the power conversion efficiency of the DSSC based on P-TiO{sub 2} compact film is about 12.5% higher than that based on H-TiO{sub 2}. Therefore, this encapsulation technology can not only improve the stability of the metal ions solution but also meet a large-scale fabrication demand of the TiO{sub 2} compact layer in future DSSCs.

Experimental observation of the layering and wetting of multilayer liquid helium-4 films on graphite

International Nuclear Information System (INIS)

Kumar, S.

1987-01-01

The multilayer adsorption of liquid 4 He on graphite was studied by using third sound, a substrate-induced surface wave in a superfluid film, to probe the 4 He film-vapor interface. The third-sound velocity decreases with increasing film thickness and can be used to monitor the film growth. Graphite, forms of which have large areas of atomic uniformity, is an ideal substrate for the study of film growth and layering. An annular resonator made out of graphite fibers was used for the experiments. Such a resonator avoids problems such as capillary condensation present in earlier resonance experiments with graphite foam and vapor sound interference present in time-of-flight experiments with highly oriented pyrolitic graphite (HOPG). Measurements of film growth were made between temperatures of 0.35 and 1.25 K. The third-sound resonance frequency, which is proportional to the third-sound velocity, was used to follow the film growth. Simultaneous measurements of the third-sound velocity on glass provide an independent measure of the film thickness. Results obtained show continuous film growth up to at least 25 to 30 layers on graphite. Oscillations of the third-sound velocity for low film coverages shown evidence of layering of the film

Optical diagnostics of lead and PbGa2S4 layered crystal laser plasmas

International Nuclear Information System (INIS)

Shuaibov, A.K.; Dashchenko, A.I.; Shevera, I.V.

2001-01-01

Laser plasmas produced at the surfaces of lead and a PbGa 2 S 4 layered crystal irradiated by a neodymium laser with λ = 1.06 μm, pulse duration τ = 20 ns, and intensity W = (1-2) x 10 9 W/cm 2 are studied using optical diagnostics. It is shown that, in a lead plasma, the most intense (characteristic) lines are the PbI 405.7-nm, PbI 368.3-nm, PbI 364-nm, and PbII 220.4-nm lines. In a layered crystal plasma, the emission spectrum is an aggregation of the most intense PbI and GaI lines, whereas sulfur lines are absent. The bottlenecks of the recombination of the ionic and atomic components of the lead and PbGa 2 S 4 crystal plasmas are determined. The average propagation velocity of the lead laser plume is 18-20 km/s. A comparative analysis of the emission dynamics of PbI and GaI lines in the laser plasmas of these metals and in the plasma of a PbGa 2 S 4 crystal is carried out. The results obtained are important for the optical diagnostics of the plasmas of lead- and gallium-containing crystals and for the optimization of laser deposition of the thin films of these substances

Preparation and characterization of highly water-soluble magnetic Fe3O4 nanoparticles via surface double-layered self-assembly method of sodium alpha-olefin sulfonate

International Nuclear Information System (INIS)

Li, Honghong; Qin, Li; Feng, Ying; Hu, Lihua; Zhou, Chunhua

2015-01-01

A kind of double-layered self-assembly sodium alpha-olefin sulfonate (AOS) capped Fe 3 O 4 magnetic nanoparticles (Fe 3 O 4 -AOS-MN) with highly water-solubility was prepared by a wet co-precipitation method with a pH of 4.8. The resulting Fe 3 O 4 -AOS-MN could be dispersed into water to form stable magnetic fluid without other treatments. The result of X-ray diffraction (XRD) indicated that the Fe 3 O 4 -AOS-MN maintained original crystalline structure and exhibited a diameter of about 7.5 nm. The iron oxide phase of nanoparticles determined by Raman spectroscopy is Fe 3 O 4 . Transmission electron microscopy (TEM) analysis confirmed that the Fe 3 O 4 -AOS-MN with spherical morphology were uniformly dispersed in water. FT-IR spectroscopy (FT-IR) and thermo-gravimetric analysis (TGA) verified the successful preparation of Fe 3 O 4 -AOS-MN capped with double-layered self-assembled AOS. The corresponding capacities of monolayer chemical absorption and the second-layer self-assembly absorption were respectively 4.07 and 14.71 wt% of Fe 3 O 4 -MN, which were much lower than those of other surfactants. Vibrating sample magnetometer (VSM) test result showed Fe 3 O 4 -AOS-MN possessed superparamagnetic behavior with the saturation magnetization value of about 44.45 emu/g. The blocking temperature T B of Fe 3 O 4 -AOS-MN capped with double-layered AOS is 170 K. - Highlights: • Double-layered self-assembly sodium alpha-olefin sulfonate (AOS) capped Fe 3 O 4 magnetic nanoparticles are prepared by a wet co-precipitation method. • Double-layered Fe 3 O 4 -AOS-MN exhibits highly water-solubility. • The iron oxide phase is determined by Raman spectroscopy. • Fe 3 O 4 -AOS-MN capped with double-layered AOS possesses super-paramagnetic behavior. • The blocking temperature T B of Fe 3 O 4 -AOS-MN capped with double-layered AOS is 170 K

Enhancement of open-circuit voltage on organic photovoltaic devices by Al-doped TiO2 modifying layer produced by sol–gel method

International Nuclear Information System (INIS)

Valaski, R.; Arantes, C.; Senna, C.A.; Carôzo, Victor; Achete, C.A.; Cremona, M.

2014-01-01

Sol–gel method has shown several advantages for oxide synthesis, such as lower cost production, coating large areas, lower processing temperatures and ease insertion of doping materials. Therefore, it is attractive for production of intermediate and electrode modifying layers in organic optoelectronic devices. Herein, spin-coated aluminum-doped titanium dioxide (AlTiO 2 ) thin films were produced by sol–gel method onto glass and fluorine-doped tin oxide (FTO) substrates, using different Al-dopant concentrations and post-done annealing temperatures. Electrical measurements were performed in order to investigate the improvement of the TiO 2 resistivity. Additionally, structural, compositional, morphological, optical and electrical properties of the optimal AlTiO 2 modifying layers onto FTO substrates were probed by different techniques, and compared with those obtained from the undoped thin films produced under similar conditions. Organic photovoltaic devices (OPVs) with the structure FTO/AlTiO 2 (30 nm)/C 60 (50 nm)/CuPc(50 nm)/Al with an Al concentration of 0.03 M in AlTiO 2 layer were produced. The insertion of AlTiO 2 thin films improved the short-circuit current density (J sc ) as well as the open circuit voltage (V oc ) in comparison with non-modified electrode FTO based devices. This behavior is discussed in terms of induced interface phenomena as dipole formation induced by Al. - Highlights: • Easy and cheap solution-process for AlTiO 2 modification of FTO electrode for OPVs • Electrical, structural and optical characterization of TiO 2 layers with Al-dopant • Improvement of Voc and Jsc of inverted OPVs with AlTiO 2 modified electrode

Role of the wetting layer in the enhanced responsivity of InAs/GaAsSb quantum dot infrared photodetectors

Energy Technology Data Exchange (ETDEWEB)

Guzmán, Álvaro, E-mail: guzman@die.upm.es; Yamamoto, Kenji; Ulloa, J. M.; Hierro, Adrian [Instituto de Sistemas Optoelectrónicos y Microtecnología y Dept. Ingeniería Electrónica, Universidad Politécnica de Madrid, ETSI de Telecomunicación, Avda. Complutense 30, 28040 Madrid (Spain); Llorens, J. M. [IMM-Instituto de Microelectrónica de Madrid (CNM-CSIC), Isaac Newton 8, PTM, E-28760 Tres Cantos, Madrid (Spain)

2015-07-06

InAs/GaAs{sub 1−x}Sb{sub x} Quantum Dot (QD) infrared photodetectors are analyzed by photocurrent spectroscopy. We observe that the integrated responsivity of the devices is improved with the increasing Sb mole fraction in the capping layer, up to 4.2 times for x = 17%. Since the QD layers are not vertically aligned, the vertical transport of the carriers photogenerated within the QDs takes place mainly through the bulk material and the wetting layer of the additional QD regions. The lower thickness of the wetting layer for high Sb contents results in a reduced capture probability of the photocarriers, thus increasing the photoconductive gain and hence, the responsivity of the device. The growth of not vertically aligned consecutive QD layers with a thinner wetting layer opens a possibility to improve the performance of quantum dot infrared photodetectors.

HARVESTING, INTEGRATING AND DISTRIBUTING LARGE OPEN GEOSPATIAL DATASETS USING FREE AND OPEN-SOURCE SOFTWARE

Directory of Open Access Journals (Sweden)

R. Oliveira

2016-06-01

Full Text Available Federal, State and Local government agencies in the USA are investing heavily on the dissemination of Open Data sets produced by each of them. The main driver behind this thrust is to increase agencies’ transparency and accountability, as well as to improve citizens’ awareness. However, not all Open Data sets are easy to access and integrate with other Open Data sets available even from the same agency. The City and County of Denver Open Data Portal distributes several types of geospatial datasets, one of them is the city parcels information containing 224,256 records. Although this data layer contains many pieces of information it is incomplete for some custom purposes. Open-Source Software were used to first collect data from diverse City of Denver Open Data sets, then upload them to a repository in the Cloud where they were processed using a PostgreSQL installation on the Cloud and Python scripts. Our method was able to extract non-spatial information from a ‘not-ready-to-download’ source that could then be combined with the initial data set to enhance its potential use.

Electron-deficient N-alkyloyl derivatives of thieno[3,4-c]pyrrole-4,6-dione yield efficient polymer solar cells with open-circuit voltages > 1 v

KAUST Repository

Warnan, Julien; Cabanetos, Clement; Bude, Romain; El Labban, Abdulrahman; LI, LIANG; Beaujuge, Pierre

2014-01-01

Poly(benzo[1,2-b:4,5-b′]dithiophene-thieno[3,4-c]pyrrole-4,6-dione) (PBDTTPD) polymer donors yield some of the highest open-circuit voltages (V OC, ca. 0.9 V) and fill factors (FF, ca. 70%) in conventional bulk-heterojunction (BHJ) solar cells

Hydrothermal Growth and Application of ZnO Nanowire Films with ZnO and TiO2Buffer Layers in Dye-Sensitized Solar Cells

Directory of Open Access Journals (Sweden)

Jiang Chunhua

2009-01-01

Full Text Available Abstract This paper reports the effects of the seed layers prepared by spin-coating and dip-coating methods on the morphology and density of ZnO nanowire arrays, thus on the performance of ZnO nanowire-based dye-sensitized solar cells (DSSCs. The nanowire films with the thick ZnO buffer layer (~0.8–1 μm thick can improve the open circuit voltage of the DSSCs through suppressing carrier recombination, however, and cause the decrease of dye loading absorbed on ZnO nanowires. In order to further investigate the effect of TiO2buffer layer on the performance of ZnO nanowire-based DSSCs, compared with the ZnO nanowire-based DSSCs without a compact TiO2buffer layer, the photovoltaic conversion efficiency and open circuit voltage of the ZnO DSSCs with the compact TiO2layer (~50 nm thick were improved by 3.9–12.5 and 2.4–41.7%, respectively. This can be attributed to the introduction of the compact TiO2layer prepared by sputtering method, which effectively suppressed carrier recombination occurring across both the film–electrolyte interface and the substrate–electrolyte interface.

Development of Thread-compatible Open Source Stack

Science.gov (United States)

Zimmermann, Lukas; Mars, Nidhal; Schappacher, Manuel; Sikora, Axel

2017-07-01

The Thread protocol is a recent development based on 6LoWPAN (IPv6 over IEEE 802.15.4), but with extensions regarding a more media independent approach, which - additionally - also promises true interoperability. To evaluate and analyse the operation of a Thread network a given open source 6LoWPAN stack for embedded devices (emb::6) has been extended in order to comply with the Thread specification. The implementation covers Mesh Link Establishment (MLE) and network layer functionality as well as 6LoWPAN mesh under routing mechanism based on MAC short addresses. The development has been verified on a virtualization platform and allows dynamical establishment of network topologies based on Thread’s partitioning algorithm.

Layered ordering of vacancies of lead iron phosphate Pb{sub 3}Fe{sub 2}(PO{sub 4}){sub 4}

Energy Technology Data Exchange (ETDEWEB)

Malakho, A.P. [Moscow State Univ., Dept. of Material Science (Russian Federation); Morozov, V.A.; Pokholok, V.; Lazoryak, B.I. [Moscow State Univ., Dept. of Chemisty (Russian Federation); Morozov, V.A.; Van Tendeloo, G. [Antwerp Univ., EMAT (Belgium)

2005-07-01

Lead iron phosphate Pb{sub 3}Fe{sub 2}(PO{sub 4}){sub 4} has been synthesized by solid state method and characterized by X-ray powder and electron diffraction, differential scanning calorimetry, Moessbauer and infrared spectroscopy. A structural model for Pb{sub 3}Fe{sub 2}(PO{sub 4}){sub 4} is proposed and is refined by the Rietveld method. The compound crystallizes in the monoclinic space group P2{sub 1}/c with a=9.0065(6) Angstroms, b=9.0574(6) Angstroms, c=9.3057(6) Angstroms, {beta}=116.880(4) degrees, V=677.10(8) (Angstroms){sup 3}, Z=2, R{sub wp}=3.52%, R{sub p}=2.66%. It exhibits a structure with a three-dimensional open framework. The 3D framework is formed by PO{sub 4} tetrahedra and FeO{sub 6} octahedra connected via common vertices. 3/4 of cavities in the framework are occupied by lead and 1/4 are vacant. (authors)

A method for opening a mine field which is adjacent to a pit

Energy Technology Data Exchange (ETDEWEB)

Onishchenko, V.I.; Grebenyuk, V.K.; Kukharev, V.N.; Martynenko, V.P.; Omelnitskiy, A.G.; Sallin, V.I.; Sidorov, A.S.

1982-01-01

The method for opening a mine field adjacent to a pit includes the construction of the main and auxiliary opening drifts in the pit and the surface complex of the mine through assembling a support with subsequent filling of them by tailings of the covering rock. In order to increase the productive capacity of the mine, to reduce capital expenditures and to increase the safety of underground operations, a base is first formed from the tailing rock along the front of the open mining operations, from the bottom of the pit at the level of the stratum being opened to the surface with simultaneous layer by layer packing of the cited base, after which the opening drifts are built on this base. The mouth of the main opening drifts and the surface complex of the mine are positioned in the region of the pit.

Synthesis, vibrational and optical properties of a new three-layered organic-inorganic perovskite (C{sub 4}H{sub 9}NH{sub 3}){sub 4}Pb{sub 3}I{sub 4}Br{sub 6}

Energy Technology Data Exchange (ETDEWEB)

Dammak, T., E-mail: thameurlpa@yahoo.f [Laboratoire de Physique appliquee (LPA), Faculte des Sciences de Sfax, 3018, BP 802 (Tunisia); Elleuch, S. [Laboratoire de Physique appliquee (LPA), Faculte des Sciences de Sfax, 3018, BP 802 (Tunisia); Bougzhala, H. [Laboratoire de cristallochimie et des materiaux, Faculte des Sciences de Tunis (Tunisia); Mlayah, A. [Centre d' Elaboration de Materiaux et d' Etudes Structurales, CNRS-Universite Paul Sabatier, 29 rue Jeanne Marvig, 31055 Toulouse, Cedex 4 (France); Chtourou, R. [Centre de Recherche et des Technologies de l' Energie CRTEn BP. 95, Hammam-Lif 2050, Laboratoire de Photovoltaique et de Semiconducteur (Tunisia); Abid, Y. [Laboratoire de Physique appliquee (LPA), Faculte des Sciences de Sfax, 3018, BP 802 (Tunisia)

2009-09-15

An organic-inorganic hybrid perovskite (C{sub 4}H{sub 9}NH{sub 3}){sub 4}Pb{sub 3}I{sub 4}Br{sub 6} was synthesized and studied by X-ray diffraction, Raman and infrared spectroscopies, optical transmission and photoluminescence. The title compound, abbreviated (C{sub 4}){sub 4}Pb{sub 3}I{sub 4}Br{sub 6}, crystallises in a periodic two-dimensional multilayer structure with P2{sub 1}/a space group. The structure is built up from alternating inorganic and organic layers. Each inorganic layer consists of three sheets of PbX{sub 6} (X=I, Br) octahedra. Raman and infrared spectra of the title compound were recorded in the 100-3500 and 400-4000 cm{sup -1} frequency ranges, respectively. An assignment of the observed vibration modes is reported. Optical transmission measurements, performed on thin films of (C{sub 4}){sub 4}Pb{sub 3}I{sub 4}Br{sub 6}, revealed two absorption bands at 474 and 508 nm. Photoluminescence measurements have shown a green emission peak at 519 nm.

Characterization Of Oxide Layers Formed On 13CrMo4-5 Steel Operated For A Long Time At An Elevated Temperature

Directory of Open Access Journals (Sweden)

Gwoździk M.

2015-09-01

Full Text Available The paper contains results of studies into the formation of oxide layers on 13CrMo4-5 (15HM steel long-term operated at an elevated temperature. The oxide layer was studied on a surface and a cross-section at the inner and outer surface of the tube wall. The 13CrMo4-5 steel operated at the temperature of 470°C during 190,000 hours was investigated. X-ray structural examinations (XRD were carried out, microscope observation s using an optical, scanning microscope were performed. The native material chemical composition was analysed by means of emission spark spectroscopy, while that of oxide layers on a scanning microscope (EDS. The studies on the topography of the oxide layers comprised studies on the roughness plane, which were carried out using a AFM microscope designed for 2D and 3D studies on the surface. Mechanical properties of the oxide layer – steel (substrate were characterised on the basis of scratch test. The adhesion of oxide layers, friction force, friction coefficient, scratching depth were determined as well as the force at which the layer was delaminated.

Synthesis, crystal structure, and ionic conductivity of a new layered metal phosphate, Li2Sr2Al(PO4)3

International Nuclear Information System (INIS)

Kim, Sung-Chul; Kwak, Hyun-Jung; Yoo, Chung-Yul; Yun, Hoseop; Kim, Seung-Joo

2016-01-01

A new layered metal phosphate, Li 2 Sr 2 Al(PO 4 ) 3 , was synthesized in the form of either a single-crystal or polycrystalline powder using the molten hydroxide flux method or a solid-state reaction, respectively. Li 2 Sr 2 Al(PO 4 ) 3 crystallizes to the P2 1 /n (Z=4) monoclinic space group with lattice parameters a≈4.95 Å, b≈22.06 Å, c≈8.63 Å, and β≈91.5°. The structure is composed of stacked [LiSrAl(PO 4 ) 2 ] layers alternating regularly with [LiSrPO 4 ] layers. In the [LiSrAl(PO 4 ) 2 ] sublattice, the AlO 6 octahedra and PO 4 tetrahedra are tilted cooperatively to form an anionic, corrugated, two-dimensional [Al(PO 4 ) 2 ] 3− framework that can be regarded as a “distorted-glaserite” structure. The [LiSrPO 4 ] sublattice is that of a layered block containing a six-membered ring formed from alternating linkages of LiO 4 and PO 4 tetrahedra. The six-membered rings show a boat-type arrangement with the up(U) or down(D) pointing sequence, UUDUUD. The interspace between the two sublattices generates a two-dimensional pathway for Li + ion conduction. The impedance measurement indicated that Li 2 Sr 2 Al(PO 4 ) 3 had a moderate ion conductivity (σ≈1.30×10 −4 S cm −1 at 667 K), with an activation energy E a ≈1.02 eV. - Graphical abstract: Polyhedral view of Li 2 Sr 2 Al(PO 4 ) 3 . Li + ions are represented by green spheres, Sr atoms by white spheres, AlO 6 groups by octahedra, and PO 4 groups by tetrahedra. - Highlights: • New compound Li 2 Sr 2 Al(PO 4 ) 3 is reported. • The crystal structure is investigated by single-crystal XRD analysis. • The structure is formed by the alternate stacking of two different sublattices. • Correlation between the crystal structure and ionic conductivity is discussed.

Syntheses, structural variants and characterization of AInM′S4 (A=alkali metals, Tl; M′ = Ge, Sn) compounds; facile ion-exchange reactions of layered NaInSnS4 and KInSnS4 compounds

International Nuclear Information System (INIS)

Yohannan, Jinu P.; Vidyasagar, Kanamaluru

2016-01-01

Ten AInM′S 4 (A=alkali metals, Tl; M′= Ge, Sn) compounds with diverse structure types have been synthesized and characterized by single crystal and powder X-ray diffraction and a variety of spectroscopic methods. They are wide band gap semiconductors. KInGeS 4 (1-β), RbInGeS 4 (2), CsInGeS 4 (3-β), TlInGeS 4 (4-β), RbInSnS 4 (8-β) and CsInSnS 4 (9) compounds with three-dimensional BaGa 2 S 4 structure and CsInGeS 4 (3-α) and TlInGeS 4 (4-α) compounds with a layered TlInSiS 4 structure have tetrahedral [InM′S 4 ] − frameworks. On the other hand, LiInSnS 4 (5) with spinel structure and NaInSnS 4 (6), KInSnS 4 (7), RbInSnS 4 (8-α) and TlInSnS 4 (10) compounds with layered structure have octahedral [InM′S 4 ] − frameworks. NaInSnS 4 (6) and KInSnS 4 (7) compounds undergo facile topotactic ion-exchange, at room temperature, with various mono-, di- and tri-valent cations in aqueous medium to give rise to metastable layered phases. - Graphical abstract: NaInSnS 4 and KInSnS 4 compounds undergo, in aqueous medium at room temperature, facile topotactic ion-exchange with mono, di and trivalent cations. Display Omitted - Highlights: • Ten AInM′S 4 compounds with diverse structure types were synthesized. • They are wide band gap semiconductors. • NaInSnS 4 and KInSnS 4 compounds undergo facile topotactic ion-exchange at room temperature.

Drag reduction using wrinkled surfaces in high Reynolds number laminar boundary layer flows

Science.gov (United States)

Raayai-Ardakani, Shabnam; McKinley, Gareth H.

2017-09-01

Inspired by the design of the ribbed structure of shark skin, passive drag reduction methods using stream-wise riblet surfaces have previously been developed and tested over a wide range of flow conditions. Such textures aligned in the flow direction have been shown to be able to reduce skin friction drag by 4%-8%. Here, we explore the effects of periodic sinusoidal riblet surfaces aligned in the flow direction (also known as a "wrinkled" texture) on the evolution of a laminar boundary layer flow. Using numerical analysis with the open source Computational Fluid Dynamics solver OpenFOAM, boundary layer flow over sinusoidal wrinkled plates with a range of wavelength to plate length ratios ( λ / L ), aspect ratios ( 2 A / λ ), and inlet velocities are examined. It is shown that in the laminar boundary layer regime, the riblets are able to retard the viscous flow inside the grooves creating a cushion of stagnant fluid that the high-speed fluid above can partially slide over, thus reducing the shear stress inside the grooves and the total integrated viscous drag force on the plate. Additionally, we explore how the boundary layer thickness, local average shear stress distribution, and total drag force on the wrinkled plate vary with the aspect ratio of the riblets as well as the length of the plate. We show that riblets with an aspect ratio of close to unity lead to the highest reduction in the total drag, and that because of the interplay between the local stress distribution on the plate and stream-wise evolution of the boundary layer the plate has to exceed a critical length to give a net decrease in the total drag force.

Laser transit anemometer and Pitot probe comparative measurements in a sharp cone boundary layer at Mach 4

Science.gov (United States)

Hunter, W. W., Jr.; Ocheltree, S. L.; Russ, C. E., Jr.

1991-01-01

Laser transit anemometer (LTA) measurements of a 7 degree sharp cone boundary layer were conducted in the Air Force/AEDC Supersonic Tunnel A Mach 4 flow field. These measurements are compared with Pitot probe measurements and tricone theory provided by AEDC staff. Measurements were made both in laminar and turbulent boundary layers of the model. Comparison of LTA measurements with theory showed agreement to better than 1 percent for the laminar boundary layer cases. This level of agreement was obtained after small position corrections, 0.01 to 0.6 mm, were applied to the experimental data sets. Pitot probe data when compared with theory also showed small positioning errors. The Pitot data value was also limited due to probe interference with the flow near the model. The LTA turbulent boundary layer data indicated a power law dependence of 6.3 to 6.9. The LTA data was analyzed in the time (Tau) domain in which it was obtained and in the velocity domain. No significant differences were noted between Tau and velocity domain results except in one turbulent boundary layer case.

Identification of novel KCNQ4 openers by a high-throughput fluorescence-based thallium flux assay.

Science.gov (United States)

Li, Qunyi; Rottländer, Mario; Xu, Mingkai; Christoffersen, Claus Tornby; Frederiksen, Kristen; Wang, Ming-Wei; Jensen, Henrik Sindal

2011-11-01

To develop a real-time thallium flux assay for high-throughput screening (HTS) of human KCNQ4 (Kv7.4) potassium channel openers, we used CHO-K1 cells stably expressing human KCNQ4 channel protein and a thallium-sensitive dye based on the permeability of thallium through potassium channels. The electrophysiological and pharmacological properties of the cell line expressing the KCNQ4 protein were found to be in agreement with that reported elsewhere. The EC(50) values of the positive control compound (retigabine) determined by the thallium and (86)rubidium flux assays were comparable to and consistent with those documented in the literature. Signal-to-background (S/B) ratio and Z factor of the thallium influx assay system were assessed to be 8.82 and 0.63, respectively. In a large-scale screening of 98,960 synthetic and natural compounds using the thallium influx assay, 76 compounds displayed consistent KCNQ4 activation, and of these 6 compounds demonstrated EC(50) values of less than 20 μmol/L and 2 demonstrated EC(50) values of less than 1 μmol/L. Taken together, the fluorescence-based thallium flux assay is a highly efficient, automatable, and robust tool to screen potential KCNQ4 openers. This approach may also be expanded to identify and evaluate potential modulators of other potassium channels. Copyright © 2011 Elsevier Inc. All rights reserved.

Custom OpenStreetMap Rendering – OpenTrackMap Experience

Directory of Open Access Journals (Sweden)

Radek Bartoň

2010-02-01

Full Text Available After 5 years of its existence, the OpenSteetMap [1] is becoming to be an important and valuable source of a geographic data for all people on the world. Although initially targeted to provide a map of cities for routing services, it can be exploited to other and often unexpected purposes. Such an utilization is an effort to map a network of hiking tracks of the Czech Tourist Club [2].  To support and apply this endeavour, the OpenTrackMap [3] project was started. Its aim is to primarily provide a customized rendering style for Mapnik renderer which emphasizes map features important to tourists and displays a layer with hiking tracks. This article presents obstacles which such project must face and it can be used as a tutorial for other projects of similar type.

Open-Source Based Testbed for Multioperator 4G/5G Infrastructure Sharing in Virtual Environments

Directory of Open Access Journals (Sweden)

Ricardo Marco Alaez

2017-01-01

Full Text Available Fourth-Generation (4G mobile networks are based on Long-Term Evolution (LTE technologies and are being deployed worldwide, while research on further evolution towards the Fifth Generation (5G has been recently initiated. 5G will be featured with advanced network infrastructure sharing capabilities among different operators. Therefore, an open-source implementation of 4G/5G networks with this capability is crucial to enable early research in this area. The main contribution of this paper is the design and implementation of such a 4G/5G open-source testbed to investigate multioperator infrastructure sharing capabilities executed in virtual architectures. The proposed design and implementation enable the virtualization and sharing of some of the components of the LTE architecture. A testbed has been implemented and validated with intensive empirical experiments conducted to validate the suitability of virtualizing LTE components in virtual infrastructures (i.e., infrastructures with multitenancy sharing capabilities. The impact of the proposed technologies can lead to significant saving of both capital and operational costs for mobile telecommunication operators.

Special Report on the Role of Open Educational Resources in Supporting the Sustainable Development Goal 4: Quality Education Challenges and Opportunities

Science.gov (United States)

McGreal, Rory

2017-01-01

Open Educational Resources (OER) and their offspring, Massive Open Online Courses (MOOCs), are becoming important factors in achieving the "Sustainable Development Goal 4: Quality Education" ("SDG4"). The OER movement is less than 15 years old and is growing rapidly as more and more nations and institutions adopt the view that…

A prospective study of the impact of opening a casino on gambling behaviours: 2- and 4-year follow-ups.

Science.gov (United States)

Jacques, Christian; Ladouceur, Robert

2006-10-01

It is widely believed that the rate of pathological gambling is related to the accessibility and availability of gambling activities. Few empirical studies have yet been conducted to evaluate this hypothesis. Using a longitudinal prospective design, the current study evaluates the impact of a casino in Canada's Hull, Quebec region. A random sample of respondents from Hull (experimental group) and from Quebec City (comparison group) completed the South Oaks Gambling Screen (SOGS) and gambling- related questions before the opening of the Hull Casino (pretest), 1 year after the opening (posttest), and on follow-up at Years 2 and 4. Although, 1 year after the opening of the casino, we did observe an increase in playing casino games and in the maximum amount of money lost in 1 day's gambling, this trend was not maintained over time (2- and 4-year follow-ups). In the Hull cohort, the rate of at-risk and probable pathological gamblers and the number of criteria on the SOGS did not increase at the 2- and 4-year follow-ups. The residents' reluctance to open a local casino was generally stable over time following the casino's opening. The discussion raises different explanatory factors and focuses on the context of the Regional Exposure Model as a potentially more applicable measure of studying the expansion of gambling.

Synthesis of rare-earth selenate and selenite materials under 'sol-gel' hydrothermal conditions: crystal structures and characterizations of La(HSeO3)(SeO4) and KNd(SeO4)2

International Nuclear Information System (INIS)

Liu Wei; Chen Haohong; Yang Xinxin; Li Mangrong; Zhao Jingtai

2004-01-01

Two rare-earth compounds containing selenium atoms, La(HSeO 3 )(SeO 4 ) with a new open framework structure and KNd(SeO 4 ) 2 with a layered structure, have been synthesized under ''sol-gel'' hydrothermal conditions for the first time. Single-crystals of La(HSeO 3 )(SeO 4 ) crystallize in the monoclinic system (P2 1 , a=8.5905(17)A, b=7.2459(14)A, c=9.5691(19)A, β=104.91(3) o , Z=2, RAll=0.032). The structure contains puckered polyhedral layers made of LaO x (x=9,10) and SeO 4 groups, which are connected via SeO 3 -uints to the 3D structure. The crytal structure of KNd(SeO 4 ) 2 (monoclinc, P2 1 /c, a=8.7182(17)A, b=7.3225(15)A, c=11.045(2)A, β=91.38(3) o , Z=4, RAll=0.051) contains honeycomb-like six-ring NdO 9 polyhedra forming layers which are further decorated with SeO 4 tetrahedra. The K + ions occupy the interspaces of these layers and provide the charge balance

Crystal structures of [Ln(NO33(μ2-bpydo2], where Ln = Ce, Pr or Nd, and bpydo = 4,4′-bipyridine N,N′-dioxide: layered coordination networks containing 44 grids

Directory of Open Access Journals (Sweden)

Michael L. Stromyer

2016-01-01

Full Text Available Three isostructural coordination networks of Ce, Pr, and Nd nitrate with 4,4′-bipyridine N,N′-dioxide (bpydo are reported, namely poly[[tris(nitrato-κ2O,O′cerium(III]-bis(μ2-4,4′-bipyridine N,N′-dioxide-κ2N:N′], [Ce(NO33(C10H8N2O22], poly[[tris(nitrato-κ2O,O′praeseodymium(III]-bis(μ2-4,4′-bipyridine N,N′-dioxide-κ2N:N′], [Pr(NO33(C10H8N2O22], and poly[[tris(nitrato-κ2O,O′neodymium(III]-bis(μ2-4,4′-bipyridine N,N′-dioxide-κ2N:N′], [Nd(NO33(C10H8N2O22]. All three compounds are isostructural to the previously reported La analogue. The asymmetric unit of [Ln(NO33(μ2-bpydo2] contains one lanthanide cation, two bpydo ligands, and three nitrate anions. Both bpydo ligands act as end-to-end μ2-bridges and display nearly ideal cis and gauche conformations, respectively. The bpydo ligands link the ten-coordinate LnIII cations, forming interdigitating 44 grid-like layers extending parallel to (-101, where interdigitation of layers is promoted by C—H...O interactions between nitrate anions and bpydo ligands. The interdigitated layers are linked to sets of neighboring layers via further C—H...O and π–π interactions.

Fluorocarbon based atomic layer etching of Si{sub 3}N{sub 4} and etching selectivity of SiO{sub 2} over Si{sub 3}N{sub 4}

Energy Technology Data Exchange (ETDEWEB)

Li, Chen [Department of Physics, and Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, Maryland 20742 (United States); Metzler, Dominik; Oehrlein, Gottlieb S., E-mail: oehrlein@umd.edu [Department of Materials Science and Engineering, and Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, Maryland 20742 (United States); Lai, Chiukin Steven; Hudson, Eric A. [Lam Research Corporation, 4400 Cushing Parkway, Fremont, California 94538 (United States)

2016-07-15

Angstrom-level plasma etching precision is required for semiconductor manufacturing of sub-10 nm critical dimension features. Atomic layer etching (ALE), achieved by a series of self-limited cycles, can precisely control etching depths by limiting the amount of chemical reactant available at the surface. Recently, SiO{sub 2} ALE has been achieved by deposition of a thin (several Angstroms) reactive fluorocarbon (FC) layer on the material surface using controlled FC precursor flow and subsequent low energy Ar{sup +} ion bombardment in a cyclic fashion. Low energy ion bombardment is used to remove the FC layer along with a limited amount of SiO{sub 2} from the surface. In the present article, the authors describe controlled etching of Si{sub 3}N{sub 4} and SiO{sub 2} layers of one to several Angstroms using this cyclic ALE approach. Si{sub 3}N{sub 4} etching and etching selectivity of SiO{sub 2} over Si{sub 3}N{sub 4} were studied and evaluated with regard to the dependence on maximum ion energy, etching step length (ESL), FC surface coverage, and precursor selection. Surface chemistries of Si{sub 3}N{sub 4} were investigated by x-ray photoelectron spectroscopy (XPS) after vacuum transfer at each stage of the ALE process. Since Si{sub 3}N{sub 4} has a lower physical sputtering energy threshold than SiO{sub 2}, Si{sub 3}N{sub 4} physical sputtering can take place after removal of chemical etchant at the end of each cycle for relatively high ion energies. Si{sub 3}N{sub 4} to SiO{sub 2} ALE etching selectivity was observed for these FC depleted conditions. By optimization of the ALE process parameters, e.g., low ion energies, short ESLs, and/or high FC film deposition per cycle, highly selective SiO{sub 2} to Si{sub 3}N{sub 4} etching can be achieved for FC accumulation conditions, where FC can be selectively accumulated on Si{sub 3}N{sub 4} surfaces. This highly selective etching is explained by a lower carbon consumption of Si{sub 3}N{sub 4} as compared to Si

TiO2 nanofiber solid-state dye sensitized solar cells with thin TiO2 hole blocking layer prepared by atomic layer deposition

International Nuclear Information System (INIS)

Li, Jinwei; Chen, Xi; Xu, Weihe; Nam, Chang-Yong; Shi, Yong

2013-01-01

We incorporated a thin but structurally dense TiO 2 layer prepared by atomic layer deposition (ALD) as an efficient hole blocking layer in the TiO 2 nanofiber based solid-state dye sensitized solar cell (ss-DSSC). The nanofiber ss-DSSCs having ALD TiO 2 layers displayed increased open circuit voltage, short circuit current density, and power conversion efficiency compared to control devices with blocking layers prepared by spin-coating liquid TiO 2 precursor. We attribute the improved photovoltaic device performance to the structural integrity of ALD-coated TiO 2 layer and consequently enhanced hole blocking effect that results in reduced dark leakage current and increased charge carrier lifetime. - Highlights: • TiO 2 blocking locking layer prepared by atomic layer deposition (ALD) method. • ALD-coated TiO 2 layer enhanced hole blocking effect. • ALD blocking layer improved the voltage, current and efficiency. • ALD blocking layer reduced dark leakage current and increased electron lifetime

Electrochemically formed passive layers on titanium - preparation and biocompatibility assessment in Hank's balanced salt solution

International Nuclear Information System (INIS)

Zhao, B.; Jerkiewicz, G.

2006-01-01

Uniform and crack-free passive layers on Ti are prepared using AC voltage in 7.5 wt.% aq. NH 4 ·BF 4 at 25 o C. The passive layers possess coloration (wide spectrum of colors) that depends on the experimental conditions. The biocompatibility of such prepared passive layers is evaluated using corrosion science and analytical techniques. Their corrosion behavior, Ti-ion release, surface roughness, and wettability in Hank's Balanced Salt Solution (HBSS) at 37 o C are the main focus of this work. Open-circuit potential and polarization measurements demonstrate that the corrosion potential (E corr ) of the passive layers becomes more positive than that of the untreated Ti. The value of E corr increases as we increase the AC voltage (VAC). Their corrosion rate (CR) is lower than that of the untreated Ti, and they reduced the Ti-ion release level from 230 to 15 ppb. An increase in the AC voltage frequency (f) leads to a slightly higher level of the Ti-ion release (∼50 ppb). Surface profilometry, optical microscopy, and scanning electron microscopy (SEM) analyses show that prolonged exposure of the passive layers to HBSS results in changes to their surface topography. The passive layers prepared by the application of AC voltage are rougher and more hydrophilic than the untreated Ti. Our methodology of preparing biocompatible passive layers on Ti might be applied as a new surface treatment procedure for Ti implants. (author)

Effect of plasma molybdenized buffer layer on adhesive properties of TiN film coated on Ti6Al4V alloy

Energy Technology Data Exchange (ETDEWEB)

Qin, Lin, E-mail: qinlin@tyut.edu.cn; Yi, Hong; Kong, Fanyou; Ma, Hua; Guo, Lili; Tian, Linhai; Tang, Bin

2017-05-01

Highlights: • A molybdenized layer was prepared as a buffer layer under TiN film on Ti6Al4V. • The molybdenized layer can enhance adhesion strength of PVD coatings effectively. • The duplex treated samples increase elastic energy ratio in the impact tests. • The enhancement attributes to the hardness improvement and inverted-S shape elastic modulus profile of the modified layer. - Abstract: Effect of molybdenized buffer layer on adhesion strength of TiN film on Ti6Al4V alloy was investigated. The buffer layer composed of a dense molybdenum deposition layer, a rapid drop zone and a slow fall zone was prepared using double glow plasma surface alloying technique. Scratch tests and low energy repeated impact tests were adopted to comparatively evaluate the duplex treated layers and the single TiN samples. The results show that the critical load was increased from 62 N for the single TiN film to over 100 N for the duplex treated layer. The volume of impact pit, formed in impact tests, of the single TiN samples is 9.15 × 10{sup 6} μm{sup 3}, and about 1.5 times than that of the duplex treated samples. The Leeb hardness values reveal that about 70% impact energy was transferred to the single TiN samples to generate permanent deformation, while that was only about 47% for the duplex treated samples. The mechanism of improving adhesion strength is attributed to synergistic effect due to an inverted-S shape elastic modulus distribution produced by the molybdenized layer.

Slot opening optimization of surface mounted permanent magnet motor for cogging torque reduction

International Nuclear Information System (INIS)

Abbaszadeh, K.; Rezaee Alam, F.; Teshnehlab, M.

2012-01-01

Highlights: ► The slot opening shift method is an efficient method for cogging torque reduction. ► Using slot opening skew method, the trapezoidal waveform of back-emf is maintained. ► Using the conventional slot skewing, the wave shape of back-emf is sinusoidal. ► The novelty of paper is using of air–gap permeance harmonics as objective function. ► Other novelty of this paper is using the different optimization algorithms. - Abstract: In this paper, slot opening skew method is used for cogging torque reduction. A three layer stator model is considered for a six-pole PM-BLDC motor (a PM-BLDC motor with 18-slots, six-poles and length of 5 cm) and then a 2D dual model is extracted for this 3D slot opening skew model. The angular shifts of slot opening position in the first and third layers than middle layer are considered as optimization parameters. Slot opening shape is optimized by using different optimization algorithms, such as, the response surface methodology (RSM), the genetic algorithm (GA) and the particle swarm optimization (PSO). In order to using of GA and PSO, the analytical relationship is derived for the air–gap permeance function. The optimization results of these algorithms are being consistent with each other and are verified with FEA results. The results show the significant reduction of cogging torque about 77%.

Optical spectroscopy of two-dimensional layered (C(6)H(5)C(2)H(4)-NH(3))(2)-PbI(4) perovskite.

Science.gov (United States)

Gauthron, K; Lauret, J-S; Doyennette, L; Lanty, G; Al Choueiry, A; Zhang, S J; Brehier, A; Largeau, L; Mauguin, O; Bloch, J; Deleporte, E

2010-03-15

We report on optical spectroscopy (photoluminescence and photoluminescence excitation) on two-dimensional self-organized layers of (C(6)H(5)C(2)H(4)-NH(3))(2)-PbI(4) perovskite. Temperature and excitation power dependance of the optical spectra gives a new insight into the excitonic and the phononic properties of this hybrid organic/inorganic semiconductor. In particular, exciton-phonon interaction is found to be more than one order of magnitude higher than in GaAs QWs. As a result, photoluminescence emission lines have to be interpreted in the framework of a polaron model.

OpenGL Insights

CERN Document Server

Cozzi, Patrick

2012-01-01

Get Real-World Insight from Experienced Professionals in the OpenGL Community With OpenGL, OpenGL ES, and WebGL, real-time rendering is becoming available everywhere, from AAA games to mobile phones to web pages. Assembling contributions from experienced developers, vendors, researchers, and educators, OpenGL Insights presents real-world techniques for intermediate and advanced OpenGL, OpenGL ES, and WebGL developers. Go Beyond the Basics The book thoroughly covers a range of topics, including OpenGL 4.2 and recent extensions. It explains how to optimize for mobile devices, explores the design

Layer-by-Layer Self-Assembled Ferrite Multilayer Nanofilms for Microwave Absorption

Directory of Open Access Journals (Sweden)

Jiwoong Heo

2015-01-01

Full Text Available We demonstrate a simple method for fabricating multilayer thin films containing ferrite (Co0.5Zn0.5Fe2O4 nanoparticles, using layer-by-layer (LbL self-assembly. These films have microwave absorbing properties for possible radar absorbing and stealth applications. To demonstrate incorporation of inorganic ferrite nanoparticles into an electrostatic-interaction-based LbL self-assembly, we fabricated two types of films: (1 a blended three-component LbL film consisting of a sequential poly(acrylic acid/oleic acid-ferrite blend layer and a poly(allylamine hydrochloride layer and (2 a tetralayer LbL film consisting of sequential poly(diallyldimethylammonium chloride, poly(sodium-4-sulfonate, bPEI-ferrite, and poly(sodium-4-sulfonate layers. We compared surface morphologies, thicknesses, and packing density of the two types of ferrite multilayer film. Ferrite nanoparticles (Co0.5Zn0.5Fe2O4 were prepared via a coprecipitation method from an aqueous precursor solution. The structure and composition of the ferrite nanoparticles were characterized by X-ray diffraction, energy dispersive X-ray spectroscopy, transmission electron microscopy, and scanning electron microscopy. X-ray diffraction patterns of ferrite nanoparticles indicated a cubic spinel structure, and energy dispersive X-ray spectroscopy revealed their composition. Thickness growth and surface morphology were measured using a profilometer, atomic force microscope, and scanning electron microscope.

Durable superhydrophobic surfaces made by intensely connecting a bipolar top layer to the substrate with a middle connecting layer.

Science.gov (United States)

Zhi, Jinghui; Zhang, Li-Zhi

2017-08-30

This study reported a simple fabrication method for a durable superhydrophobic surface. The superhydrophobic top layer of the durable superhydrophobic surface was connected intensely to the substrate through a middle connecting layer. Glycidoxypropyltrimethoxysilane (KH-560) after hydrolysis was used to obtain a hydrophilic middle connecting layer. It could be adhered to the hydrophilic substrate by covalent bonds. Ring-open reaction with octadecylamine let the KH-560 middle layer form a net-like structure. The net-like sturcture would then encompass and station the silica particles that were used to form the coarse micro structures, intensely to increase the durability. The top hydrophobic layer with nano-structures was formed on the KH-560 middle layer. It was obtained by a bipolar nano-silica solution modified by hexamethyldisilazane (HMDS). This layer was connected to the middle layer intensely by the polar Si hydroxy groups, while the non-polar methyl groups on the surface, accompanied by the micro and nano structures, made the surface rather hydrophobic. The covalently interfacial interactions between the substrate and the middle layer, and between the middle layer and the top layer, strengthened the durability of the superhydrophobic surface. The abrasion test results showed that the superhydrophobic surface could bear 180 abrasion cycles on 1200 CW sandpaper under 2 kPa applied pressure.

Nitrite reduction on a multimetallic porphyrin/polyoxotungstate layer-by-layer modified electrodes

International Nuclear Information System (INIS)

García, Macarena; Honores, Jessica; Quezada, Diego; Díaz, Carlos; Dreyse, Paulina; Celis, Freddy; Kubiak, Clifford P.; Canzi, Gabriele; Guzmán, Fernando

2016-01-01

Electro and photoelectrochemical reduction of nitrite in aqueous solution was studied using a multielectrocatalysts modified ITO electrode. ITO modification was carried out using the layer-by-layer (LBL) method, where sequential electrostatic assemblies were formed using a μ-(meso-5,10,15,20-tetra(pirydil)porphyrin)tetrakis{bis(bipyridine)chloride ruthenium (II)} [MTRP] n+ , coordinated in its central cavity with Mn(III), Zn(II) or Ni(II) as a cationic layer, and polyoxotungstate [SiW 12 O 40 ] 4− as the anionic layer. Electrochemical measurements and UV–vis spectroscopy were used to monitor the modification process. Optimal results were obtained when three layers were deposited onto the ITO surface and were stable in aqueous solution. The order of the multilayer formation was explored by comparing a modified electrode where [Zn(II)TRP] 4+ was the outermost layer with an electrode where [SiW 12 O 40 ] 4− was the outer layer. Results show that the best performing electrode is one with [SiW 12 O 40 ] 4− as the outer layer. Nitrite reduction on these electrode surfaces was studied in dark conditions and under light irradiation. Potential controlled electrolysis experiments were also performed, finding hydroxylamine, hydrazine and ammonia as the reduction products in dark conditions. Under light irradiation, only hydrazine and ammonia were found and, we observed an increase in the amount of obtained product. In this case, the electrolysis was carried out 150 mV less and half of time than in dark conditions. These results show that the combination of light and potential give rise to an improvement in the electrocatalytic properties of the modified electrodes. Continuous photolysis and IR spectroelectrochemical experiments were carried out to determinate the nature of this phenomena, evidencing the formation of an intermediary species between nitrite and [Mn(III)TRP] 5+.

Coupling of magnetopause-boundary layer to the polar ionosphere

International Nuclear Information System (INIS)

Wei, C.Q.; Lee, L.C.

1993-01-01

The authors develop a model which seeks to explain ultraviolet auroral images from the Viking satellite which show periodic bright regions which resemble open-quotes beadsclose quotes or open-quotes pearlsclose quotes aligned along the postnoon auroral oval. ULF geomagnetic pulsations observed in the cusp region are also addressed by this model. The model addresses plasma dynamics in the low-latitude boundary layer and interactions with the polar ionosphere by means of field-aligned current. The Kelvin-Helmholtz instability can develop in the presence of driven plasma flow, which can lead to the formation and growth of plasma vortices in the boundary layer. The finite conductivity of the earth ionosphere causes these vortices to decay. However regions of enhanced field-aligned power density in the postnoon auroral oval can be associated with field-aligned current filaments and boundary layer vortices. These structures may explain the observed bright spots. The authors also discuss the frequency spectrum and the polarization state of the pulsations

Numerical modelling of the erosion and deposition of sand inside a filter layer

DEFF Research Database (Denmark)

Jacobsen, Niels Gjøl; van Gent, Marcel R. A.; Fredsøe, Jørgen

2017-01-01

This paper treats the numerical modelling of the behaviour of a sand core covered by rocks and exposed to waves. The associated displacement of the rock is also studied. A design that allows for erosion and deposition of the sand core beneath a rock layer in a coastal structure requires an accurate...... prediction method to assure that the amount of erosion remains within acceptable limits. This work presents a numerical model that is capable of describing the erosion and deposition patterns inside of an open filter of rock on top of sand. The hydraulic loading is that of incident irregular waves...... and the open filters are surface piercing. Due to the few experimental data sets on sediment transport inside of rock layers, a sediment transport formulation has been proposed based on a matching between the numerical model and experimental data on the profile deformation inside an open filter. The rock layer...

Facile synthesis of NaYF4:Yb, Ln/NaYF4:Yb core/shell upconversion nanoparticles via successive ion layer adsorption and one-pot reaction technique

NARCIS (Netherlands)

Zeng, Q.; Xue, B.; Zhang, Y.; Wang, D.; Liu, X.; Tu, L.; Zhao, H.; Kong, X.; Zhang, H.

2013-01-01

The facile one-pot synthesis of NaYF4:Yb, Ln/NaYF4:Yb core/shell (CS) upconversion nanoparticles (UCNPs) was firstly developed through the successive ion layer adsorption and reaction (SILAR) technique, which represents an attractive alternative to conventional synthesis utilizing the chloride of Ln

Critical current density of four-CuO2-layer T1Ba2Ca3Cu4O11-δ

International Nuclear Information System (INIS)

Zhang, L.; Liu, J.Z.; Shelton, R.N.

1998-01-01

Full text: A key requirement for technological application is to have superconductors with high critical current density at practical operating temperatures and magnetic fields. The critical current density is strongly related to underlying properties of high T c superconductors, such as layering, anisotropy and other intrinsic material structures. The thallium-based superconductors attracted much attention at early stage mainly due to their high superconducting transitions. Recent studies show that these materials appear to be a better choice for achieving higher critical current density because of a stronger interlayer coupling between superconducting layers. Single crystals of TlBa 2 Ca 3 Cu 4 O 11-δ were grown by a self-flux method. This material is a strong-layered superconductor with four-CuO 2 -planes in a unit cell and a superconducting transition temperature of 128K. Our experimental results show that TlBa 2 Ca 3 Cu 4 O 11-δ crystals have high irreversibility line, large critical current density and high upper critical field. The impact of layering and the number of Cu-O layers on flux pinning, critical current density and other magnetic properties will also be discussed

Single-Layer Halide Perovskite Light-Emitting Diodes with Sub-Band Gap Turn-On Voltage and High Brightness.

Science.gov (United States)

Li, Junqiang; Shan, Xin; Bade, Sri Ganesh R; Geske, Thomas; Jiang, Qinglong; Yang, Xin; Yu, Zhibin

2016-10-03

Charge-carrier injection into an emissive semiconductor thin film can result in electroluminescence and is generally achieved by using a multilayer device structure, which requires an electron-injection layer (EIL) between the cathode and the emissive layer and a hole-injection layer (HIL) between the anode and the emissive layer. The recent advancement of halide perovskite semiconductors opens up a new path to electroluminescent devices with a greatly simplified device structure. We report cesium lead tribromide light-emitting diodes (LEDs) without the aid of an EIL or HIL. These so-called single-layer LEDs have exhibited a sub-band gap turn-on voltage. The devices obtained a brightness of 591 197 cd m -2 at 4.8 V, with an external quantum efficiency of 5.7% and a power efficiency of 14.1 lm W -1 . Such an advancement demonstrates that very high efficiency of electron and hole injection can be obtained in perovskite LEDs even without using an EIL or HIL.

Capacitance of carbon-based electrical double-layer capacitors.

Science.gov (United States)

Ji, Hengxing; Zhao, Xin; Qiao, Zhenhua; Jung, Jeil; Zhu, Yanwu; Lu, Yalin; Zhang, Li Li; MacDonald, Allan H; Ruoff, Rodney S

2014-01-01

Experimental electrical double-layer capacitances of porous carbon electrodes fall below ideal values, thus limiting the practical energy densities of carbon-based electrical double-layer capacitors. Here we investigate the origin of this behaviour by measuring the electrical double-layer capacitance in one to five-layer graphene. We find that the capacitances are suppressed near neutrality, and are anomalously enhanced for thicknesses below a few layers. We attribute the first effect to quantum capacitance effects near the point of zero charge, and the second to correlations between electrons in the graphene sheet and ions in the electrolyte. The large capacitance values imply gravimetric energy storage densities in the single-layer graphene limit that are comparable to those of batteries. We anticipate that these results shed light on developing new theoretical models in understanding the electrical double-layer capacitance of carbon electrodes, and on opening up new strategies for improving the energy density of carbon-based capacitors.

Growth and microstructure of iron nitride layers and pore formation in {epsilon}-Fe{sub 3}N

Energy Technology Data Exchange (ETDEWEB)

Middendorf, C.; Mader, W. [Univ. Bonn, Inst. fuer Anorganische Chemie, Bonn (Germany)

2003-03-01

Layers of {epsilon}-Fe{sub 3}N and {gamma}'-Fe{sub 4}N on ferrite were produced by nitriding iron single crystals or rolled sheets of iron in flowing ammonia at 520 C. The nitride layers were characterised using X-ray diffraction, light microscopy as well as scanning and transmission electron microscopy. The compound layer consists of {epsilon}-Fe{sub 3}N at the surface and of {gamma}'-Fe{sub 4}N facing the ferrite. After 4 h of nitriding, pores develop in the near surface region of {epsilon}-Fe{sub 3}N showing more or less open porosity. Growth of the entire compound layer as well as of the massive and the porous {epsilon}-Fe{sub 3}N sublayer is diffusion-controlled and follows a parabolic growth rate. The {gamma}'-Fe{sub 4}N layer is formed as a transition phase within a narrow interval of nitrogen activity, and it shows little growth in thickness. The transformation of {gamma}'-Fe{sub 4}N to {epsilon}-Fe{sub 3}N is topotactic, where the orientation of the closed-packed iron layers of the crystal structures is preserved. Determination of lattice plane spacings was possible by X-ray diffraction, and this was correlated to the nitrogen content of {epsilon}-Fe{sub 3}N. While the porous layer exhibits an enhanced nitrogen content corresponding to the chemical composition Fe{sub 3}N{sub 1.1}, the massive e Fe{sub 3}N layer corresponds to Fe{sub 3}N{sub 1.0}. The pore formation in {epsilon}-Fe{sub 3}N{sub 1.1} is concluded to be the result of excess nitrogen atoms on non-structural sites, which have a high mobility. Therefore, recombination of excess nitrogen to molecular N{sub 2} at lattice defects is preferred in {epsilon}-Fe{sub 3}N with high nitrogen content compared to stoichiometric {epsilon}-Fe{sub 3}N{sub 1.0} with nitrogen on only structural sites. (orig.)

Layers And Processes In The Model Of Technological Postal System

Directory of Open Access Journals (Sweden)

Madleňáková Lucia

2015-12-01

Full Text Available The paper include important aspects of layer model of postal technological system such as makes the possibility to define rules for regulating, technical and technological requirements and interfaces to communicate with other postal systems. The current postal reform is mainly attributable to release of network access and ensuring full interoperability between technological systems. Not only to ensure the development and protection of competition but also in respect to the conservation of requirements to provide the universal service, which is the performance of public interest. There is a space here to examine the postal system, not only from a procedural point of view, but to be viewed as an open communication system. It is possible to find there the commonalities with other communication sector branches and to handle the technological postal system in more layers; similarly as the electronic communication systems are handled. Model of layer postal system, based not only on the processes but on layers functionality, will enable to identify communication protocols and interfaces determining interoperability. It also opens the question of appropriate regulation model.

Fabrication, characterization and applications of flexible vertical InGaN micro-light emitting diode arrays.

Science.gov (United States)

Tian, Pengfei; McKendry, Jonathan J D; Gu, Erdan; Chen, Zhizhong; Sun, Yongjian; Zhang, Guoyi; Dawson, Martin D; Liu, Ran

2016-01-11

Flexible vertical InGaN micro-light emitting diode (micro-LED) arrays have been fabricated and characterized for potential applications in flexible micro-displays and visible light communication. The LED epitaxial layers were transferred from initial sapphire substrates to flexible AuSn substrates by metal bonding and laser lift off techniques. The current versus voltage characteristics of flexible micro-LEDs degraded after bending the devices, but the electroluminescence spectra show little shift even under a very small bending radius 3 mm. The high thermal conductivity of flexible metal substrates enables high thermal saturation current density and high light output power of the flexible micro-LEDs, benefiting the potential applications in flexible high-brightness micro-displays and high-speed visible light communication. We have achieved ~40 MHz modulation bandwidth and 120 Mbit/s data transmission speed for a typical flexible micro-LED.

Effect of a thermally evaporated bis (2-methyl-8-quninolinato)-4-phenylphenolate cathode buffer layer on the performance of polymer photovoltaic cells

International Nuclear Information System (INIS)

Kim, Dal-Ho; Park, Jea-Gun

2012-01-01

We investigated the device characteristics of polymer photovoltaic (PV) cells based on a poly(3 hexylthiophene) (P3HT) and [6,6]-phenylC61 butyric acid methyl ester (PCBM) bulk heterojunction with a cathode buffer layer of thermally evaporated bis (2-methyl-8-quninolinato)-4-phenylphenolate (BAlq). A power conversion efficiency (PCE) of 2.46% was obtained with the insertion of a 4-nm-thick BAlq, which was ∼118% increase over that for the cell without a BAlq layer, under Air Mass 1.5 Global (AM 1.5 G) illumination, 100 mW/cm 2 . Moreover, we examined the charge carrier transport property, and found that the hole mobility of the cell was enhancement due to the insertion of a BAlq layer with a thickness of less than 4 nm, which accounted for the improved in the photocurrent and fill factor (FF) due to the better balance of charge carriers. Finally, the BAlq buffer layer was also demonstrated as an optical spacer that improved the optical absorption of the P3HT:PCBM layer, which accounted for the J sc enhancement of the device.

Effective Vectorization with OpenMP 4.5

Energy Technology Data Exchange (ETDEWEB)

Huber, Joseph N. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Hernandez, Oscar R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Lopez, Matthew Graham [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2017-03-01

This paper describes how the Single Instruction Multiple Data (SIMD) model and its extensions in OpenMP work, and how these are implemented in different compilers. Modern processors are highly parallel computational machines which often include multiple processors capable of executing several instructions in parallel. Understanding SIMD and executing instructions in parallel allows the processor to achieve higher performance without increasing the power required to run it. SIMD instructions can significantly reduce the runtime of code by executing a single operation on large groups of data. The SIMD model is so integral to the processor s potential performance that, if SIMD is not utilized, less than half of the processor is ever actually used. Unfortunately, using SIMD instructions is a challenge in higher level languages because most programming languages do not have a way to describe them. Most compilers are capable of vectorizing code by using the SIMD instructions, but there are many code features important for SIMD vectorization that the compiler cannot determine at compile time. OpenMP attempts to solve this by extending the C++/C and Fortran programming languages with compiler directives that express SIMD parallelism. OpenMP is used to pass hints to the compiler about the code to be executed in SIMD. This is a key resource for making optimized code, but it does not change whether or not the code can use SIMD operations. However, in many cases critical functions are limited by a poor understanding of how SIMD instructions are actually implemented, as SIMD can be implemented through vector instructions or simultaneous multi-threading (SMT). We have found that it is often the case that code cannot be vectorized, or is vectorized poorly, because the programmer does not have sufficient knowledge of how SIMD instructions work.

The effect of the phase composition of compound layer on the growth kinetics of the nitrided layer

International Nuclear Information System (INIS)

Ratajski, J.; Olik, R.; Suszko, T.; Tacikowski, J.

2001-01-01

This paper presents a part of research work on the kinetics of formation and growth of nitrided layers on 40HM steel that was conducted within the research project devoted to the control of gaseous nitriding processes. The purpose of the research was to find answers to still opened questions connected with the optimization of the growth kinetics of nitrided layer. It has been demonstrated in particular how important in diffusion layer kinetics of growth on steel is the role-played by compound layer phase composition. Mainly, this refers to designing changes of parameters in processes where accurate formation of layer on precise parts with required tolerance of size changes is demanded. It comes out of the presented research that proper diffusion layer growth kinetics can be achieved when phase ε dominates in the compound layer. This domination of the phase ε influences speed of growth of the compound layer and first of all growth of diffusion layer. The obtained results are also a starting point of for working-out of good functional relations which could create good basis for design of algorithms of potential values changes in the function of the process time which provides the optimal kinetics of the growth of the layers. In this respect it has been achieved very good qualitative relation between the simulated distribution of nitrogen concentration in the layer and experimentally established distribution of hardness. (author)

New Layered Oxide-Fluoride Perovskites: KNaNbOF5 and KNaMO2F4 (M = Mo6+, W6+

Directory of Open Access Journals (Sweden)

Rachelle Ann F. Pinlac

2011-03-01

Full Text Available KNaNbOF5 and KNaMO2F4 (M = Mo6+, W6+, three new layered oxide-fluoride perovskites with the general formula ABB’X6, form from the combination of a second-order Jahn-Teller d0 transition metal and an alkali metal (Na+ on the B-site. Alternating layers of cation vacancies and K+ cations on the A-site complete the structure. The K+ cations are found in the A-site layer where the fluoride ions are located. The A-site is vacant in the adjacent A-site layer where the axial oxides are located. This unusual layered arrangement of unoccupied A-sites and under bonded oxygen has not been observed previously although many perovskite-related structures are known.

Optimization of Rear Local Al-Contacts on High Efficiency Commercial PERC Solar Cells with Dot and Line Openings

Directory of Open Access Journals (Sweden)

Peisheng Liu

2014-01-01

Full Text Available Crystalline silicon PERCs with dot or line openings on rear surface were studied here. By measuring the minor carrier lifetimes of the PERCs with dot and line openings, passivation effects of rear surface with dot and line openings were discussed. The performance affected by dot and line openings was analyzed in detail by testing the open-circuit voltages, short-circuit current densities, fill factors, and conversion efficiencies of the PERCs. The results show that the wider space resulted in better minor carrier lifetimes on the rear surface. And the cells with a line opening space of 0.5 mm had an average of 0.22% improvement of conversion efficiency, compared with the cells with full-area Al-BSF. On the other hand, the dot opening PERCs exhibited only a conversion efficiency of 17.4%, although there had been good rear surface reflectivity. The bad Al-Si alloy layer and large hollow densities in dot Al-contacts resulted in bad performance of the PERCs with dot openings.

Performance of High Layer Thickness in Selective Laser Melting of Ti6Al4V

Directory of Open Access Journals (Sweden)

Xuezhi Shi

2016-12-01

Full Text Available To increase building rate and save cost, the selective laser melting (SLM of Ti6Al4V with a high layer thickness (200 μm and low cost coarse powders (53 μm–106 μm at a laser power of 400 W is investigated in this preliminary study. A relatively large laser beam with a diameter of 200 μm is utilized to produce a stable melt pool at high layer thickness, and the appropriate scanning track, which has a smooth surface with a shallow contact angle, can be obtained at the scanning speeds from 40 mm/s to 80 mm/s. By adjusting the hatch spacings, the density of multi-layer samples can be up to 99.99%, which is much higher than that achieved in previous studies about high layer thickness selective laser melting. Meanwhile, the building rate can be up to 7.2 mm3/s, which is about 2 times–9 times that of the commercial equipment. Besides, two kinds of defects are observed: the large un-melted defects and the small spherical micropores. The formation of the un-melted defects is mainly attributed to the inappropriate overlap rates and the unstable scanning tracks, which can be eliminated by adjusting the processing parameters. Nevertheless, the micropores cannot be completely eliminated. It is worth noting that the high layer thickness plays a key role on surface roughness rather than tensile properties during the SLM process. Although a sample with a relatively coarse surface is generated, the average values of yield strength, ultimate tensile strength, and elongation are 1050 MPa, 1140 MPa, and 7.03%, respectively, which are not obviously different than those with the thin layer thickness used in previous research; this is due to the similar metallurgical bonding and microstructure.

Performance of High Layer Thickness in Selective Laser Melting of Ti6Al4V.

Science.gov (United States)

Shi, Xuezhi; Ma, Shuyuan; Liu, Changmeng; Chen, Cheng; Wu, Qianru; Chen, Xianping; Lu, Jiping

2016-12-01

To increase building rate and save cost, the selective laser melting (SLM) of Ti6Al4V with a high layer thickness (200 μm) and low cost coarse powders (53 μm-106 μm) at a laser power of 400 W is investigated in this preliminary study. A relatively large laser beam with a diameter of 200 μm is utilized to produce a stable melt pool at high layer thickness, and the appropriate scanning track, which has a smooth surface with a shallow contact angle, can be obtained at the scanning speeds from 40 mm/s to 80 mm/s. By adjusting the hatch spacings, the density of multi-layer samples can be up to 99.99%, which is much higher than that achieved in previous studies about high layer thickness selective laser melting. Meanwhile, the building rate can be up to 7.2 mm³/s, which is about 2 times-9 times that of the commercial equipment. Besides, two kinds of defects are observed: the large un-melted defects and the small spherical micropores. The formation of the un-melted defects is mainly attributed to the inappropriate overlap rates and the unstable scanning tracks, which can be eliminated by adjusting the processing parameters. Nevertheless, the micropores cannot be completely eliminated. It is worth noting that the high layer thickness plays a key role on surface roughness rather than tensile properties during the SLM process. Although a sample with a relatively coarse surface is generated, the average values of yield strength, ultimate tensile strength, and elongation are 1050 MPa, 1140 MPa, and 7.03%, respectively, which are not obviously different than those with the thin layer thickness used in previous research; this is due to the similar metallurgical bonding and microstructure.

Characterization and diffusion model for the titanium boride layers formed on the Ti6Al4V alloy by plasma paste boriding

Energy Technology Data Exchange (ETDEWEB)

Keddam, Mourad, E-mail: keddam@yahoo.fr [Laboratoire de Technologie des Matériaux, Faculté de Génie Mécanique et Génie des Procédés, USTHB, B.P. No. 32, 16111 El-Alia, Bab-Ezzouar, Algiers (Algeria); Taktak, Sukru [Metallurgical and Materials Engineering, Faculty of Technology, Afyon Kocatepe University, ANS Campus, 03200, Afyonkarahisar (Turkey)

2017-03-31

Highlights: • Titanium boride layers were produced by plasma paste boriding on Ti6Al4V at 973–1073 K. • Formation rates of the Ti boride layers have parabolic character at all temperatures. • Boron diffusivities were estimated using a diffusion model including incubation times. • Activation energies of boron in TiB{sub 2} and TiB were 136 and 63 kJ/mol respectively. - Abstract: The present study is focused on the estimation of activation energy of boron in the plasma paste borided Ti6Al4V alloy, which is extensively used in technological applications, using an analytical diffusion model. Titanium boride layers were successfully produced by plasma paste boriding method on the Ti6Al4V alloy in the temperature range of 973–1073 K for a treatment time ranging from 3 to 7 h. The presence of both TiB{sub 2} top-layer and TiB whiskers sub-layer was confirmed by the XRD analysis and SEM observations. The surface hardness of the borided alloy was evaluated using Micro-Knoop indenter. The formation rates of the TiB{sub 2} and TiB layers were found to have a parabolic character at all applied process temperatures. A diffusion model was suggested to estimate the boron diffusivities in TiB{sub 2} and TiB layers under certain assumptions, by considering the effect of boride incubation times. Basing on own experimental data on boriding kinetics, the activation energies of boron in TiB{sub 2} and TiB phases were estimated as 136.24 ± 0.5 and 63.76 ± 0.5 kJ mol{sup −1}, respectively. Finally, the obtained values of boron activation energies for Ti6Al4V alloy were compared with the data available in the literature.

Deliverable D.8.4. Social data visualization and navigation services -3rd Year Update-

NARCIS (Netherlands)

Bitter-Rijpkema, Marlies; Brouns, Francis; Drachsler, Hendrik; Fazeli, Soude; Sanchez-Alonso, Salvador; Rajabi, Enayat; Kolovou, Lamprini

2015-01-01

Within the Open Discovery Space our study (T.8.4) focused on ”Enhanced Social Data Visualization & Navigation Services. This deliverable provides the prototype report regarding the deployment of adapted visualization and navigation services to be integrated in the ODS Social Data Management Layer.

Open system architecture for condition based maintenance applied to a hydroelectric power plant

Energy Technology Data Exchange (ETDEWEB)

Amaya, E.J.; Alvares, A.J. [University of Brasilia (UnB), DF (Brazil). Mechanical and Mechatronic Dept.], Emails: eamaya@unb.br, alvares@AlvaresTech.com; Gudwin, R.R. [State University of Campinas (UNICAMP), SP (Brazil). Computer Engineering and Industrial Automation Dept.], E-mail: gudwin@dca.fee.unicamp.br

2009-07-01

The hydroelectric power plant of Balbina is implementing a condition based maintenance system applying an open, modular and scalable integrated architecture to provide comprehensive solutions and support to the end users like operational and maintenance team. The system called SIMPREBAL (Predictive Maintenance System of Balbina) is advocate of open standards, in particular through collaborative research programmers. In the developing is clearly understands the need for both, industry standards and a simple to use software development tool chain, supporting the development of complex condition based maintenance systems with multiple partners. The Open System Architecture for Condition Based Maintenance (OSA-CBM) is a standard that consider seven hierarchic layers that represent a logic transition or performed data flow from the data acquisition layer, through the intermediates layers as signal processing, condition monitor, health assessment, prognostics and decision support, to arrive to the presentation layer. SIMPREBAL is being implementing as an OSA-CBM software framework and tool set that allows the creation of truly integrated, comprehensive maintenance solutions through the internet. This paper identifies specific benefits of the application of the OSA-CBM in comprehensive solutions of condition based maintenance for a hydroelectric power plant. (author)

Tomato golden mosaic virus open reading frame AL4 is genetically distinct from its C4 analogue in monopartite geminiviruses.

Science.gov (United States)

Pooma, W; Petty, I T

1996-08-01

Tomato golden mosaic virus (TGMV) is a bipartite geminivirus with six well-characterized genes. An additional open reading frame (ORF), AL4, lies within the essential AL1 gene. Recent studies of monopartite, dicot-infecting geminiviruses have revealed that mutations in their analogous C4 ORFs have host-specific effects on infectivity, symptomatology, virus movement and/or viral DNA accumulation. We have investigated whether TGMV has a similar host-specific requirement for AL4. The phenotypes of three TGMV al4 mutants were determined in a range of hosts, which included species that revealed c4 mutant phenotypes for monopartite geminiviruses. Each TGMV al4 mutant was indistinguishable from wild-type TGMV in all hosts tested. Additional analyses of double mutants revealed no evidence for functional redundancy between AL4 and the AL3, or AR1 genes. In contrast to the putative C4 proteins of monpartite geminiviruses, TGMV AL4, if it is expressed, is either non-functional, or functionally redundant with an essential TGMV gene product.

Open tubular capillary column for the separation of cytochrome C tryptic digest in capillary electrochromatography.

Science.gov (United States)

Ali, Faiz; Cheong, Won Jo

2015-10-01

A silica capillary of 50 μm internal diameter and 500 mm length (416 mm effective length) was chemically modified with 4-(trifluoromethoxy) phenyl isocyanate in the presence of dibutyl tin dichloride as catalyst. Sodium diethyl dithiocarbamate was reacted with the terminal halogen of the bound ligand to incorporate the initiator moiety, and in situ polymerization was performed using a monomer mixture of styrene, N-phenylacrylamide, and methacrylic acid. The resultant open tubular capillary column immobilized with the copolymer layer was used for the separation of tryptic digest of cytochrome C in capillary electrochromatography. The sample was well eluted and separated into many components. The elution patterns of tryptic digest of cytochrome C were studied with respect to pH and water content in the mobile phase. This preliminary study demonstrates that open tubular capillary electrochromatography columns with a modified copolymer layer composed of proper nonpolar and polar units fabricated by reversible addition-fragmentation transfer polymerization can be useful as separation media for proteomic analysis. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Chromium Renderserver: Scalable and Open Source Remote RenderingInfrastructure

Energy Technology Data Exchange (ETDEWEB)

Paul, Brian; Ahern, Sean; Bethel, E. Wes; Brugger, Eric; Cook,Rich; Daniel, Jamison; Lewis, Ken; Owen, Jens; Southard, Dale

2007-12-01

Chromium Renderserver (CRRS) is software infrastructure thatprovides the ability for one or more users to run and view image outputfrom unmodified, interactive OpenGL and X11 applications on a remote,parallel computational platform equipped with graphics hardwareaccelerators via industry-standard Layer 7 network protocolsand clientviewers. The new contributions of this work include a solution to theproblem of synchronizing X11 and OpenGL command streams, remote deliveryof parallel hardware-accelerated rendering, and a performance analysis ofseveral different optimizations that are generally applicable to avariety of rendering architectures. CRRSis fully operational, Open Sourcesoftware.

Enhancement of open-circuit voltage on organic photovoltaic devices by Al-doped TiO{sub 2} modifying layer produced by sol–gel method

Energy Technology Data Exchange (ETDEWEB)

Valaski, R.; Arantes, C.; Senna, C.A.; Carôzo, Victor; Achete, C.A. [Materials Metrology Division, Instituto Nacional de Metrologia, Qualidade e Tecnologia, Xerém, Duque de Caxias 25250-020, RJ (Brazil); Cremona, M., E-mail: cremona@fis.puc-rio.br [Materials Metrology Division, Instituto Nacional de Metrologia, Qualidade e Tecnologia, Xerém, Duque de Caxias 25250-020, RJ (Brazil); Physics Department, Pontifícia Universidade Católica do Rio de Janeiro, Rio de Janeiro 22453-970, RJ (Brazil)

2014-12-01

Sol–gel method has shown several advantages for oxide synthesis, such as lower cost production, coating large areas, lower processing temperatures and ease insertion of doping materials. Therefore, it is attractive for production of intermediate and electrode modifying layers in organic optoelectronic devices. Herein, spin-coated aluminum-doped titanium dioxide (AlTiO{sub 2}) thin films were produced by sol–gel method onto glass and fluorine-doped tin oxide (FTO) substrates, using different Al-dopant concentrations and post-done annealing temperatures. Electrical measurements were performed in order to investigate the improvement of the TiO{sub 2} resistivity. Additionally, structural, compositional, morphological, optical and electrical properties of the optimal AlTiO{sub 2} modifying layers onto FTO substrates were probed by different techniques, and compared with those obtained from the undoped thin films produced under similar conditions. Organic photovoltaic devices (OPVs) with the structure FTO/AlTiO{sub 2}(30 nm)/C{sub 60}(50 nm)/CuPc(50 nm)/Al with an Al concentration of 0.03 M in AlTiO{sub 2} layer were produced. The insertion of AlTiO{sub 2} thin films improved the short-circuit current density (J{sub sc}) as well as the open circuit voltage (V{sub oc}) in comparison with non-modified electrode FTO based devices. This behavior is discussed in terms of induced interface phenomena as dipole formation induced by Al. - Highlights: • Easy and cheap solution-process for AlTiO{sub 2} modification of FTO electrode for OPVs • Electrical, structural and optical characterization of TiO{sub 2} layers with Al-dopant • Improvement of Voc and Jsc of inverted OPVs with AlTiO{sub 2} modified electrode.

Open Source Tools for Numerical Simulation of Urban Greenhouse Gas Emissions

Science.gov (United States)

Nottrott, A.; Tan, S. M.; He, Y.

2016-12-01

There is a global movement toward urbanization. Approximately 7% of the global population lives in just 28 megacities, occupying less than 0.1% of the total land area used by human activity worldwide. These cities contribute a significant fraction of the global budget of anthropogenic primary pollutants and greenhouse gasses. The 27 largest cities consume 9.9%, 9.3%, 6.7% and 3.0% of global gasoline, electricity, energy and water use, respectively. This impact motivates novel approaches to quantify and mitigate the growing contribution of megacity emissions to global climate change. Cities are characterized by complex topography, inhomogeneous turbulence, and variable pollutant source distributions. These features create a scale separation between local sources and urban scale emissions estimates known as the Grey-Zone. Modern computational fluid dynamics (CFD) techniques provide a quasi-deterministic, physically based toolset to bridge the scale separation gap between source level dynamics, local measurements, and urban scale emissions inventories. CFD has the capability to represent complex building topography and capture detailed 3D turbulence fields in the urban boundary layer. This presentation discusses the application of OpenFOAM to urban CFD simulations of natural gas leaks in cities. OpenFOAM is an open source software for advanced numerical simulation of engineering and environmental fluid flows. When combined with free or low cost computer aided drawing and GIS, OpenFOAM generates a detailed, 3D representation of urban wind fields. OpenFOAM was applied to model methane (CH4) emissions from various components of the natural gas distribution system, to investigate the impact of urban meteorology on mobile CH4 measurements. The numerical experiments demonstrate that CH4 concentration profiles are highly sensitive to the relative location of emission sources and buildings. Sources separated by distances of 5-10 meters showed significant differences in

Light illumination intensity dependence of photovoltaic parameter in polymer solar cells with ammonium heptamolybdate as hole extraction layer.

Science.gov (United States)

Liu, Zhiyong; Niu, Shengli; Wang, Ning

2018-01-01

A low-temperature, solution-processed molybdenum oxide (MoO X ) layer and a facile method for polymer solar cells (PSCs) is developed. The PSCs based on a MoO X layer as the hole extraction layer (HEL) is a significant advance for achieving higher photovoltaic performance, especially under weaker light illumination intensity. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) measurements show that the (NH 4 ) 6 Mo 7 O 24 molecule decomposes and forms the molybdenum oxide (MoO X ) molecule when undergoing thermal annealing treatment. In this study, PSCs with the MoO X layer as the HEL exhibited better photovoltaic performance, especially under weak light illumination intensity (from 100 to 10mWcm -2 ) compared to poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS)-based PSCs. Analysis of the current density-voltage (J-V) characteristics at various light intensities provides information on the different recombination mechanisms in the PSCs with a MoO X and PEDOT:PSS layer as the HEL. That the slopes of the open-circuit voltage (V OC ) versus light illumination intensity plots are close to 1 unity (kT/q) reveals that bimolecular recombination is the dominant and weaker monomolecular recombination mechanism in open-circuit conditions. That the slopes of the short-circuit current density (J SC ) versus light illumination intensity plots are close to 1 reveals that the effective charge carrier transport and collection mechanism of the MoO X /indium tin oxide (ITO) anode is the weaker bimolecular recombination in short-circuit conditions. Our results indicate that MoO X is an alternative candidate for high-performance PSCs, especially under weak light illumination intensity. Copyright © 2017 Elsevier Inc. All rights reserved.

Conceptual Architecture of Building Energy Management Open Source Software (BEMOSS)

Energy Technology Data Exchange (ETDEWEB)

Khamphanchai, Warodom; Saha, Avijit; Rathinavel, Kruthika; Kuzlu, Murat; Pipattanasomporn, Manisa; Rahman, Saifur; Akyol, Bora A.; Haack, Jereme N.

2014-12-01

The objective of this paper is to present a conceptual architecture of a Building Energy Management Open Source Software (BEMOSS) platform. The proposed BEMOSS platform is expected to improve sensing and control of equipment in small- and medium-sized buildings, reduce energy consumption and help implement demand response (DR). It aims to offer: scalability, robustness, plug and play, open protocol, interoperability, cost-effectiveness, as well as local and remote monitoring. In this paper, four essential layers of BEMOSS software architecture -- namely User Interface, Application and Data Management, Operating System and Framework, and Connectivity layers -- are presented. A laboratory test bed to demonstrate the functionality of BEMOSS located at the Advanced Research Institute of Virginia Tech is also briefly described.

Effect of nuclear radiation on the electrical properties of chemical double layer capacitors

International Nuclear Information System (INIS)

Laghari, J.R.; Hammoud, A.N.

1990-01-01

The effects of nuclear radiation on the electrical properties of chemical double layer capacitors are determined. The capacitors were irradiated in a 2-MW nuclear reactor to different fluence levels. The exposure rate was 2.2 x 10 10 n/cm 2 · s of thermal neutrons, 9.52 x 10 8 n/cm 2 · s of fast neutrons (> 2 MeV), and 1.47 x 10 6 rad/h of gamma radiation. The properties measured during and after irradiation included the capacitance, equivalent series resistance, and open-circuit voltage. The post-irradiation effect on the leakage current was also determined. It was found that while the capacitance increased during irradiation, the equivalent series resistance and the open-circuit voltage decreased slightly during irradiation. Changes in these properties were not permanent s was evident from post-irradiation measurements. The leakage current did not show any significant change with radiation. The results indicate that chemical double layer capacitors can be suitably used as backup power source in electronic equipment operating in a radiation environment with total fluences up to 4.05 x 10 14 n/cm 2

Superconductivity in few-layer stanene

Science.gov (United States)

Liao, Menghan; Zang, Yunyi; Guan, Zhaoyong; Li, Haiwei; Gong, Yan; Zhu, Kejing; Hu, Xiao-Peng; Zhang, Ding; Xu, Yong; Wang, Ya-Yu; He, Ke; Ma, Xu-Cun; Zhang, Shou-Cheng; Xue, Qi-Kun

2018-04-01

A single atomic slice of α-tin—stanene—has been predicted to host the quantum spin Hall effect at room temperature, offering an ideal platform to study low-dimensional and topological physics. Although recent research has focused on monolayer stanene, the quantum size effect in few-layer stanene could profoundly change material properties, but remains unexplored. By exploring the layer degree of freedom, we discover superconductivity in few-layer stanene down to a bilayer grown on PbTe, while bulk α-tin is not superconductive. Through substrate engineering, we further realize a transition from a single-band to a two-band superconductor with a doubling of the transition temperature. In situ angle-resolved photoemission spectroscopy (ARPES) together with first-principles calculations elucidate the corresponding band structure. The theory also indicates the existence of a topologically non-trivial band. Our experimental findings open up novel strategies for constructing two-dimensional topological superconductors.

Dynamics of the Energy Transfer to the Load During the Operation of a Plasma Opening Switch

International Nuclear Information System (INIS)

Dolinsky, Yu.; Krasik, Ya.E.; Felsteiner, J.

1999-01-01

The main efforts of the theoretical and experimental studies related to the Plasma Opening Switch (POS) have been devoted to the understanding of an anomalous fast magnetic field penetration through the plasma. At present this phenomenon can be explained based on the electron magnetohydrodynamic theory.l The second important phenomenon is related with POS opening. Existing models explain POS opening as a result of cut-off of the electron current component in the double layer2 by self-magnetic field of the POS current or by the increase of the Hall potential in the current layer due to ion erosion.3 Nevertheless both models consider POS opening in the region which was preliminary occupied by the plasma. In a recent experiment4 it was shown that the POS opening is related with a fast charged particle flow in the downstream region, namely at the load. In this work we present results of theoretical studies of the phase of the POS operation when the self-magnetic field of the POS current appears at the downstream side of the plasma. Our study has been done within the framework of two-fluid magnetohydrodynamic theory. Taking into account the Hall electric field which is responsible for a strong ion acceleration in the axial direction, we found the velocity of the ions. In addition we show, that due to the inductive electric field caused by the motion of the axial current carrying plasma, the velocity of the magnetic field penetration is equal to the Alfven velocity

Layered double hydroxides for preparing CoMn_2O_4 nanoparticles as anodes of lithium ion batteries

International Nuclear Information System (INIS)

Pan, Xu; Ma, Jingjing; Yuan, Ruo; Yang, Xia

2017-01-01

In the field of lithium-ion batteries, CoMn_2O_4 as an anode material has attracted a wide attention because it inherited the splendid electrochemical performances of Mn and Co-based metal oxides. Compared to graphite, Co-based oxides have a higher capacity which is about twice of the graphite. Moreover, Mn-based oxides have lower operating voltages and manganese exists abundantly in nature. Layered double hydroxides (LDHs), similar with brucite structure, were used as precursor for CoMn_2O_4 nanoparticles in this work. Under high temperature process, the LDHs decomposed to CoMn_2O_4 nanoparticles. When evaluated as anode materials for lithium ion batteries, the CoMn_2O_4 nanoparticles behaved good electrochemical performance with the discharge and charge capacity of 733 mAh g"-"1 and 721 mAh g"-"1 at current density of 200 mA g"-"1 after 100 cycles. This method for preparing CoMn_2O_4 nanoparticles is easy, which may provide a way for synthesis of other bimetallic oxides and anodes of lithium ion batteries. - Highlights: • Layered double hydroxides were employed as precursors to synthesize CoMn_2O_4. • The CoMn_2O_4 nanoparticles behaved good electrochemical performance. • This study provides a guideline for preparing bimetallic oxides.

Polygonal Prism Mesh in the Viscous Layers for the Polyhedral Mesh Generator, PolyGen

International Nuclear Information System (INIS)

Lee, Sang Yong; Park, Chan Eok; Kim, Shin Whan

2015-01-01

Polyhedral mesh has been known to have some benefits over the tetrahedral mesh. Efforts have been made to set up a polyhedral mesh generation system with open source programs SALOME and TetGen. The evaluation has shown that the polyhedral mesh generation system is promising. But it is necessary to extend the capability of the system to handle the viscous layers to be a generalized mesh generator. A brief review to the previous works on the mesh generation for the viscous layers will be made in section 2. Several challenging issues for the polygonal prism mesh generation will be discussed as well. The procedure to generate a polygonal prism mesh will be discussed in detail in section 3. Conclusion will be followed in section 4. A procedure to generate meshes in the viscous layers with PolyGen has been successfully designed. But more efforts have to be exercised to find the best way for the generating meshes for viscous layers. Using the extrusion direction of the STL data will the first of the trials in the near future

A systematic determination of diffusion coefficients of trace elements in open and restricted diffusive layers used by the diffusive gradients in a thin film technique

DEFF Research Database (Denmark)

Shiva, Amir Houshang; Teasdale, Peter R.; Bennett, William W.

2015-01-01

A systematic comparison of the diffusion coefficients of cations (Al, Cd, Co, Cu, Mn, Ni, Pb, Zn) and oxyanions (Al, As, Mo, Sb, V, W) in open (ODL) and restricted (RDL) diffusive layers used by the DGT technique was undertaken. Diffusion coefficients were measured using both the diffusion cell...... concentrations required with the Dcell measurements. This is the first time that D values have been reported for several oxyanions using RDL. Except for Al at pH 8.30 with ODL, all DDGT measurements were retarded relative to diffusion coefficients in water (DW) for both diffusive hydrogels. Diffusion in RDL...

Development of a single-ring OpenPET prototype

Energy Technology Data Exchange (ETDEWEB)

Yoshida, Eiji, E-mail: rush@nirs.go.jp; Tashima, Hideaki; Wakizaka, Hidekatsu; Nishikido, Fumihiko; Hirano, Yoshiyuki; Inadama, Naoko; Murayama, Hideo; Ito, Hiroshi; Yamaya, Taiga

2013-11-21

One of the challenging applications of PET is implementing it for in-beam PET, which is an in situ monitoring method for charged particle therapy. For this purpose, we have previously proposed an open-type PET scanner, OpenPET. The original OpenPET had a physically opened field-of-view (FOV) between two detector rings through which irradiation beams pass. This dual-ring OpenPET (DROP) had a wide axial FOV including the gap. This geometry was not necessarily the most efficient for application to in-beam PET in which only a limited FOV around the irradiation field is required. Therefore, we have proposed a new single-ring OpenPET (SROP) geometry which can provide an accessible and observable open space with higher sensitivity and a reduced number of detectors than the DROP. The proposed geometry was a cylinder shape with its ends cut at a slant, in which the shape of each cut end became an ellipse. In this work, we developed and evaluated a small prototype of the SROP geometry for proof-of-concept. The SROP prototype was designed with 2 ellipse-shaped detector rings of 16 depth-of-interaction (DOI) detectors each. The DOI detectors consisted of 1024 GSOZ scintillator crystals which were arranged in 4 layers of 16×16 arrays, coupled to a 64-channel FP-PMT. Each ellipse-shaped detector ring had a major axis of 281.6 mm and a minor axis of 207.5 mm. For the slant mode, the rings were placed at a 45-deg slant from the axial direction and for the non-slant mode (used as a reference) they were at 90 deg from the axial direction with no gap. The system sensitivity measured from a {sup 22}Na point source was 5.0% for the slant mode. The average spatial resolutions of major and minor axis directions were calculated as 3.8 mm FWHM and 4.9 mm FWHM, respectively for the slant mode. This difference resulted from the ellipsoidal ring geometry and the spatial resolution of the minor axis direction degraded by the parallax error. Comparison between the slant mode and the non

Cadmium free high efficiency Cu2ZnSn(S,Se4 solar cell with Zn1−xSnxOy buffer layer

Directory of Open Access Journals (Sweden)

Md. Asaduzzaman

2017-06-01

Full Text Available We have investigated the simulation approach of a one-dimensional online simulator named A Device Emulation Program and Tool (ADEPT2.1 and the device performances of a thin film solar cell based on Cu2ZnSn(S,Se4 (CZTSSe absorber have been measured. Initiating with a thin film photovoltaic device structure consisting of n-ZnO:Al/i-ZnO/Zn1-xSnxOy (ZTO/CZTSSe/Mo/SLG stack, a graded space charge region (SCR and an inverted surface layer (ISL were inserted between the buffer and the absorber. The cadmium (Cd free ZTO buffer, a competitive substitute to the CdS buffer, significantly contributes to improve the open-circuit voltage, Voc without deteriorating the short-circuit current density, Jsc. The optimized solar cell performance parameters including Voc, Jsc, fill factor (FF, and efficiency (η were calculated from the current density-voltage curve, also known as J–V characteristic curve. The FF was determined as 73.17%, which in turns, yields a higher energy conversion efficiency of 14.09%.

Effect of incorporation of silver nanoparticles in PEDOT:PSS layer on performance of organic solar cell

Science.gov (United States)

Singh, Joginder; Nirwal, Varun Singh; Bhatnagar, P. K.; Peta, Koteswara Rao

2018-05-01

Solution processable organic solar cells have attracted significant interest in scientific community due to their easy processability, flexibility and eco friendly fabrication. In these organic solar cells structure, PEDOT:PSS layer has major importance as it used as hole transporting layer. In the present work, we have analyzed the effect of incorporation of silver nanoparticles (AgNPs) in PEDOT:PSS layer for P3HT:PCBM based organic solar cells. The presence of Ag nanoparticles in PEDOT:PSS film is confirmed by atomic force microscopy (AFM) images. It has been observed that PEDOT:PSS layer with AgNPs has ˜5.4% more transmittance than PEDOT:PSS layer in most of the visible region, which helps in reaching more light on active layer. Finally, solar cell with structure ITO/PEDOT:PSS:AgNPs/Al is fabricated and J-V characteristics are plotted under illumination. It is observed that there is a significant (˜10%) enhancement in short circuit current and slight increment in open circuit voltage with addition of AgNPs in PEDOT:PSS layer. The calculated value of power conversion efficiency (PCE) of fabricated device without AgNPs in PEDOT:PSS was 1.67%, which increased to 2.02% after addition of AgNPs in PEDOT:PSS layer.

A Corrosion Investigation of Solder Candidates for High-Temperature Applications

DEFF Research Database (Denmark)

Chidambaram, Vivek; Hald, John; Ambat, Rajan

2009-01-01

The step soldering approach is being employed in the Multi-Chip module (MCM) technology. High lead containing alloys is one of the solders currently being used in this approach. Au-Sn and Au-Ge based candidate alloys have been proposed as alternative solders for this application. In this work...

Structural studies of five layer Aurivillius oxides: A2Bi4Ti5O18 (A=Ca, Sr, Ba and Pb)

International Nuclear Information System (INIS)

Ismunandar; Kamiyama, T.; Hoshikawa, A.; Zhou, Q.; Kennedy, B.J.; Kubota, Y.; Kato, K.

2004-01-01

The room temperature structures of the five layer Aurivillius phases A 2 Bi 4 Ti 5 O 18 , (A=Ca, Sr, Ba and Pb) have been refined from powder neutron diffraction data using the Rietveld method. The structures consist of [Bi 2 O 2 ] 2+ layers interleaved with perovskite-like [A 2 Bi 2 Ti 5 O 16 ] 2- blocks. The structures were refined in the orthorhombic space group B2eb (SG. No. 41), Z=4, and the unit cell parameters of the oxides are a=5.4251(2), b=5.4034(1), c=48.486(1); a=5.4650(2), b=5.4625(3), c=48.852(1); a=5.4988(3), b=5.4980(4), c=50.352(1); a=5.4701(2), b=5.4577(2), c=49.643(1) for A=Ca, Sr, Ba and Pb, respectively. The structural features of the compounds were found similar to n=2-4 layers bismuth oxides. The strain caused by mismatch of cell parameter requirements for the [Bi 2 O 2 ] 2+ layers and perovskite-like [A 2 Bi 2 Ti 5 O 16 ] 2- blocks were relieved by tilting of the TiO 6 octahedra. Variable temperature synchrotron X-ray studies for Ca and Pb compounds showed that the orthorhombic structure persisted up to 675 and 475K, respectively. Raman spectra of the compounds are also presented

Preparation and characterization of highly water-soluble magnetic Fe{sub 3}O{sub 4} nanoparticles via surface double-layered self-assembly method of sodium alpha-olefin sulfonate

Energy Technology Data Exchange (ETDEWEB)

Li, Honghong; Qin, Li [School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022 (China); Feng, Ying [Department of Bridge Engineering, Shanxi Railway Institute, Weinan 714000 (China); Hu, Lihua [School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022 (China); Zhou, Chunhua, E-mail: chm_zhouch@ujn.edu.cn [School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022 (China)

2015-06-15

A kind of double-layered self-assembly sodium alpha-olefin sulfonate (AOS) capped Fe{sub 3}O{sub 4} magnetic nanoparticles (Fe{sub 3}O{sub 4}-AOS-MN) with highly water-solubility was prepared by a wet co-precipitation method with a pH of 4.8. The resulting Fe{sub 3}O{sub 4}-AOS-MN could be dispersed into water to form stable magnetic fluid without other treatments. The result of X-ray diffraction (XRD) indicated that the Fe{sub 3}O{sub 4}-AOS-MN maintained original crystalline structure and exhibited a diameter of about 7.5 nm. The iron oxide phase of nanoparticles determined by Raman spectroscopy is Fe{sub 3}O{sub 4}. Transmission electron microscopy (TEM) analysis confirmed that the Fe{sub 3}O{sub 4}-AOS-MN with spherical morphology were uniformly dispersed in water. FT-IR spectroscopy (FT-IR) and thermo-gravimetric analysis (TGA) verified the successful preparation of Fe{sub 3}O{sub 4}-AOS-MN capped with double-layered self-assembled AOS. The corresponding capacities of monolayer chemical absorption and the second-layer self-assembly absorption were respectively 4.07 and 14.71 wt% of Fe{sub 3}O{sub 4}-MN, which were much lower than those of other surfactants. Vibrating sample magnetometer (VSM) test result showed Fe{sub 3}O{sub 4}-AOS-MN possessed superparamagnetic behavior with the saturation magnetization value of about 44.45 emu/g. The blocking temperature T{sub B} of Fe{sub 3}O{sub 4}-AOS-MN capped with double-layered AOS is 170 K. - Highlights: • Double-layered self-assembly sodium alpha-olefin sulfonate (AOS) capped Fe{sub 3}O{sub 4} magnetic nanoparticles are prepared by a wet co-precipitation method. • Double-layered Fe{sub 3}O{sub 4}-AOS-MN exhibits highly water-solubility. • The iron oxide phase is determined by Raman spectroscopy. • Fe{sub 3}O{sub 4}-AOS-MN capped with double-layered AOS possesses super-paramagnetic behavior. • The blocking temperature T{sub B} of Fe{sub 3}O{sub 4}-AOS-MN capped with double-layered AOS is 170 K.

Ecological niches of open ocean phytoplankton taxa

DEFF Research Database (Denmark)

Brun, Philipp Georg; Vogt, Meike; Payne, Mark

2015-01-01

We characterize the realized ecological niches of 133 phytoplankton taxa in the open ocean based on observations from the MAREDAT initiative and a statistical species distribution model (MaxEnt). The models find that the physical conditions (mixed layer depth, temperature, light) govern large...... conditions in the open ocean. Our estimates of the realized niches roughly match the predictions of Reynolds' C-S-R model for the global ocean, namely that taxa classified as nutrient stress tolerant have niches at lower nutrient and higher irradiance conditions than light stress tolerant taxa. Yet...

[(CH3)3NCH2CH2NH3]SnI4: a layered perovskite with quaternary/primary ammonium dications and short interlayer iodine-iodine contacts.

Science.gov (United States)

Xu, Zhengtao; Mitzi, David B; Medeiros, David R

2003-03-10

The organic-inorganic hybrid [(CH(3))(3)NCH(2)CH(2)NH(3)]SnI(4) presents a layered perovskite structure, templated by an organic dication containing both a primary and a quaternary ammonium group. Due to the high charge density and small size of the organic cation, the separation of the perovskite layers is small and short iodine-iodine contacts of 4.19 A are formed between the layers. Optical thin-film measurements on this compound indicate a significant red shift of the exciton peak (630 nm) associated with the band gap, as compared with other SnI(4)(2)(-)-based layered perovskite structures.

Double-layer Electromagnetic Wave Absorber Based on Carbon Nanotubes Doped with La(NO33 and Fe3O4 Nanoparticles

Directory of Open Access Journals (Sweden)

Cuiling HOU

2017-08-01

Full Text Available Double-layer structure absorbing materials based on the impedance matching principle and transmission line theory can effectively improve the electromagnetic wave absorbing properties. In this paper, the electro-magnetic wave absorbing properties of double-layer absorbers (2 mm thickness, where multiwall carbon nanotube (MWCNT-La(NO33/polyvinyl chloride (PVC and MWCNT-Fe3O4/PVC composites had been taken turns as the absorption layer and matching layer, were investigated in 2 – 18 GHz range. The absorbing properties of single- and double-layer structure and different each-layer thickness with two types of combinations were compared. The results showed that the design of double-layer structure for composites could effectively broaden the absorption frequency area, and increase the absorption intensity. When MWCNT-La(NO33/PVC composite were used as absorption layers with 0.6 mm thickness, the absorption bandwidth (< – 15 dB or > 97 % of double-layer composite was the widest, reaching a maximum of about 3.36 GHz, and the absorption peak value was also the lowest about – 46.02 dB at 16.24 GHz.DOI: http://dx.doi.org/10.5755/j01.ms.23.3.16279

Alumina and Hafnia ALD Layers for a Niobium-Doped Titanium Oxide Photoanode

Directory of Open Access Journals (Sweden)

Naji Al Dahoudi

2012-01-01

Full Text Available Niobium-doped titanium dioxide (TiO2 nanoparticles were used as a photoanode in dye-sensitized solar cells (DSCs. They showed a high photocurrent density due to their higher conductivity; however, a low open-circuit voltage was exhibited due to the back-reaction of photogenerated electrons. Atomic layer deposition is a useful technique to form a conformal ultrathin layer of Al2O3 and HfO, which act as an energy barrier to suppress the back electrons from reaching the redox medium. This resulted in an increase of the open-circuit voltage and therefore led to higher performance. HfO showed an improvement of the light-to-current conversion efficiency by 74%, higher than the 21% enhancement obtained by utilizing Al2O3 layers.

A Ruddlesden-Popper-type layered perovskite, Na2Ca2Nb4O13

International Nuclear Information System (INIS)

Chiba, K.; Ishizawa, N.; Oishi, S.

1999-01-01

Single crystals of disodium dicalcium tetraniobium tridecaoxide, Na 2 Ca 2 Nb 4 O 13 , were grown by the flux method. The structure was determined in space group Bb2 1 m. Perovskite-type layers with the formula [(Ca 2 Na)Nb 4 O 13 ] - are concatenated by Na + cations near the interlayer, forming a Ruddlesden-Popper-type structure. The interlayer structure, composed of Na and O atoms, can be regarded as a rocksalt-type. NbO 6 octahedra are tilted about [010] and [001]. The off-centre displacement of Nb atoms suggests a ferroelectric nature along [010], with a calculated magnitude of polarization of 0.12 C m -2 . (orig.)

A high open-circuit voltage gallium nitride betavoltaic microbattery

International Nuclear Information System (INIS)

Cheng, Zaijun; Chen, Xuyuan; San, Haisheng; Feng, Zhihong; Liu, Bo

2012-01-01

A high open-circuit voltage betavoltaic microbattery based on a gallium nitride (GaN) p–i–n homojunction is demonstrated. As a beta-absorbing layer, the low electron concentration of the n-type GaN layer is achieved by the process of Fe compensation doping. Under the irradiation of a planar solid 63 Ni source with activity of 0.5 mCi, the open-circuit voltage of the fabricated microbattery with 2 × 2 mm 2 area reaches as much as 1.64 V, which is the record value reported for betavoltaic batteries with 63 Ni source, the short-circuit current was measured as 568 pA and the conversion effective of 0.98% was obtained. The experimental results suggest that GaN is a high-potential candidate for developing the betavoltaic microbattery. (paper)

Monitoring layer-by-layer assembly of polyelectrolyte multi-layers using high-order cladding mode in long-period fiber gratings

Czech Academy of Sciences Publication Activity Database

Tian, F.; Kaňka, Jiří; Li, X.; Du, H.

-, č. 196 (2014), s. 475-479 ISSN 0925-4005 R&D Projects: GA MŠk(CZ) LH11038 Institutional support: RVO:67985882 Keywords : Layer-by-layer assembly * Polyelectrolyte * Cladding mode Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 4.097, year: 2014

Bismuth-doped Cu(In,Ga)Se2 absorber prepared by multi-layer precursor method and its solar cell

International Nuclear Information System (INIS)

Chantana, Jakapan; Hironiwa, Daisuke; Minemoto, Takashi; Watanabe, Taichi; Teraji, Seiki; Kawamura, Kazunori

2015-01-01

Bismuth (Bi)-doped Cu(In,Ga)Se 2 (CIGS) films were prepared by the so-called ''multi-layer precursor method'', obtained by depositing them onto Bi layers with various thicknesses on Mo-coated soda-lime glass (SLG) substrates. Material composition (Cu, In, Ga, and Se) profiles of the CIGS films are almost identical, whereas sodium (Na) is reduced, when Bi thickness is increased. Moreover, the incorporation of Bi into the CIGS film is enhanced with thicker Bi layer. With Bi thickness from 0 to 70 nm, the 2.4-μm-thick CIGS absorbers demonstrate the increase in CIGS grain size, carrier lifetime, and carrier concentration, thus improving their cell performances, especially open-circuit voltage (V OC ). With further increase in Bi thickness of above 70 nm, the CIGS films show the deterioration of CIGS film quality owing to the formation of Bi compounds such as Bi, BiSe, and Bi 4 Se 3 . Consequently, Bi-doped CIGS absorber with thickness of 2.4 μm, prepared with the 70-nm-thick Bi layer on Mo-coated SLG substrate, gives rise to the improvement of photovoltaic performances, especially V OC . (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Development of pure Mg open-cell foams as structured CO{sub 2} captor

Energy Technology Data Exchange (ETDEWEB)

Figueroa, I.A., E-mail: iafiguera@unam.mx [Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México (UNAM), Circuito Exterior S/N, Cd. Universitaria, C.P. 04510 México, D.F. (Mexico); Suarez, M.A.; Velasco-Castro, M.; Pfeiffer, H.; Alcántar-Vázquez, B.; González, G. [Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México (UNAM), Circuito Exterior S/N, Cd. Universitaria, C.P. 04510 México, D.F. (Mexico); Alfonso, I. [Instituto de Investigaciones en Materiales, Unidad Morelia, Universidad Nacional Autónoma de México, Campus Morelia UNAM, Antigua Carretera a Pátzcuaro No. 8701, Col. Ex-Hacienda de San José de la Huerta, C.P. 58190 Morelia, Michoacán (Mexico); Lara-Rodríguez, G.A. [Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México (UNAM), Circuito Exterior S/N, Cd. Universitaria, C.P. 04510 México, D.F. (Mexico)

2015-12-10

Highlights: • The CO{sub 2} capture capacity of the open-cell Mg foams was studied at low temperatures. • Open-cell Mg foams with pore size of 350 μm were used for the CO{sub 2} capture study. • The highest amount of CO{sub 2} captured was obtained at 60 °C and 80% of relative humidity. • A CO{sub 2} capture capacity of 0.87 mmol/g was obtained for the open-cell Mg foams. • The oxidized open-cell Mg foams can be used as CO{sub 2} captors. - Abstract: The CO{sub 2} capture capacity of the superficial oxide layer formed in pure open-cell Mg foams was studied at low temperatures (40–60 °C) varying the relative humidity from 40 to 80%. Mg foam samples with pore size of 350 μm and surface area of 5.4 m{sup 2}/g were used for these analyses. Optical microscopy and X-ray diffraction techniques were used to characterize the cell structure and the superficial oxide formed in the cell-foams, respectively. The final products formed after the CO{sub 2}–H{sub 2}O capture experiments were identified by scanning electron microscopy and attenuated total reflexion-Fourier transform infrared spectroscopy (ATR-FTIR). The MgCO{sub 3} and other products, formed after CO{sub 2} + H{sub 2}O capture process, were thermally decomposed, to quantify the amount of CO{sub 2} captured by the superficial MgO layer using standard thermogravimetric analysis. The results showed that the highest amount of CO{sub 2} captured was obtained at 60 °C and 80% of relative humidity, with a CO{sub 2} capture capacity of 0.87 mmol/g, which is comparable with others CO{sub 2} MgO-based captors. The considerable CO{sub 2} capture capacity at low temperatures supports the potential of the pure open-cell Mg foams to be used as structured CO{sub 2} captors.

Layer-by-layer assembly of MXene and carbon nanotubes on electrospun polymer films for flexible energy storage.

Science.gov (United States)

Zhou, Zehang; Panatdasirisuk, Weerapha; Mathis, Tyler S; Anasori, Babak; Lu, Canhui; Zhang, Xinxing; Liao, Zhiwei; Gogotsi, Yury; Yang, Shu

2018-03-29

Free-standing, highly flexible and foldable supercapacitor electrodes were fabricated through the spray-coating assisted layer-by-layer assembly of Ti3C2Tx (MXene) nanoflakes together with multi-walled carbon nanotubes (MWCNTs) on electrospun polycaprolactone (PCL) fiber networks. The open structure of the PCL network and the use of MWCNTs as spacers not only limit the restacking of Ti3C2Tx flakes but also increase the accessible surface of the active materials, facilitating fast diffusion of electrolyte ions within the electrode. Composite electrodes have areal capacitance (30-50 mF cm-2) comparable to other templated electrodes reported in the literature, but showed significantly improved rate performance (14-16% capacitance retention at a scan rate of 100 V s-1). Furthermore, the composite electrodes are flexible and foldable, demonstrating good tolerance against repeated mechanical deformation, including twisting and folding. Therefore, these tens of micron thick fiber electrodes will be attractive for applications in energy storage, electroanalytical chemistry, brain electrodes, electrocatalysis and other fields, where flexible freestanding electrodes with an open and accessible surface are highly desired.

Propagation characteristics of SH wave in an mm2 piezoelectric layer on an elastic substrate

Directory of Open Access Journals (Sweden)

Yanping Kong

2015-09-01

Full Text Available We investigate the propagation characteristics of shear horizontal (SH waves in a structure consisting of an elastic substrate and an mm2 piezoelectric layer with different cut orientations. The dispersion equations are derived for electrically open and shorted conditions on the free surface of the piezoelectric layer. The phase velocity and electromechanical coupling coefficient are calculated for a layered structure with a KNbO3 layer perfectly bonded to a diamond substrate. The dispersion curves for the electrically shorted boundary condition indicate that for a given cut orientation, the phase velocity of the first mode approaches the B-G wave velocity of the KNbO3 layer, while the phase velocities of the higher modes tend towards the limit velocity of the KNbO3 layer. For the electrically open boundary condition, the asymptotic phase velocities of all modes are the limit velocity of the KNbO3 layer. In addition, it is found that the electromechanical coupling coefficient strongly depends on the cut orientation of the KNbO3 crystal. The obtained results are useful in device applications.

Triple-layer appearance of Brodmann area 4 at thin-section double inversion-recovery MR imaging.

Science.gov (United States)

Kim, Eung Yeop; Kim, Dong-Hyun; Chang, Jong-Hee; Yoo, Eunhye; Lee, Jae-Wook; Park, Hae-Jeong

2009-02-01

To investigate whether thin-section axial double inversion-recovery (DIR) brain magnetic resonance (MR) imaging at 3.0 T can help distinguish the primary motor cortex (PMC), or Brodmann area 4, from other selected cortical regions, including the primary sensory cortex (PSC), or Brodmann areas 1-3, on the basis of the presence of a "triple-layer" appearance. This prospective study was approved by the institutional review board; informed consent was obtained from patients. This study included 191 patients (94 female, age range, 5-80 years; 97 male, age range, 5-76 years) with normal findings at 3.0-T MR imaging. The presence or absence of a triple-layer appearance within selected cortical regions on DIR images was graded independently by two neuroradiologists as definitely present (grade 2), probably present (grade 1), or definitely absent (grade 0). Ten additional patients with tumors underwent DIR imaging and intraoperative cortical mapping for further validation of the PMC. A myelin-stained brain specimen image in a patient not imaged with DIR was correlated with a representative set of DIR images. A triple-layer appearance was found in the PMC bilaterally in 184 of 191 patients; grade 0 was assigned in only seven patients, who were all younger than 10 years. Grades were significantly lower in patients younger than 10 years than in others (P .0018). Interobserver agreement was excellent (weighted kappa = 0.843). The PMC determined on DIR images was confirmed with cortical mapping in all 10 patients with tumors. Triple-layer appearance was not present in the other cortical regions examined, including the PSC (P < .01). The triple-layer appearance on DIR images corresponded to the myelin band within the PMC present on the myelin-stained specimen image. A triple-layer appearance was found in the PMC at thin-section 3.0-T DIR imaging but not in other examined brain regions and therefore might be useful as an adjunct sign for identification of motor regions.

Thermal comfort sustained by cold protective clothing in Arctic open-pit mining-a thermal manikin and questionnaire study.

Science.gov (United States)

Jussila, Kirsi; Rissanen, Sirkka; Aminoff, Anna; Wahlström, Jens; Vaktskjold, Arild; Talykova, Ljudmila; Remes, Jouko; Mänttäri, Satu; Rintamäki, Hannu

2017-12-07

Workers in the Arctic open-pit mines are exposed to harsh weather conditions. Employers are required to provide protective clothing for workers. This can be the outer layer, but sometimes also inner or middle layers are provided. This study aimed to determine how Arctic open-pit miners protect themselves against cold and the sufficiency, and the selection criteria of the garments. Workers' cold experiences and the clothing in four Arctic open-pit mines in Finland, Sweden, Norway and Russia were evaluated by a questionnaire (n=1,323). Basic thermal insulation (I cl ) of the reported clothing was estimated (ISO 9920). The I cl of clothing from the mines were also measured by thermal manikin (standing/walking) in 0.3 and 4.0 m/s wind. The questionnaire showed that the I cl of the selected clothing was on average 1.2 and 1.5 clo in mild (-5 to +5°C) and dry cold (-20 to -10°C) conditions, respectively. The I cl of the clothing measured by thermal manikin was 1.9-2.3 clo. The results show that the Arctic open-pit miners' selected their clothing based on occupational (time outdoors), environmental (temperature, wind, moisture) and individual factors (cold sensitivity, general health). However, the selected clothing was not sufficient to prevent cooling completely at ambient temperatures below -10°C.

Miniaturization of Multiple-Layer Folded Patch Antennas

DEFF Research Database (Denmark)

Zhang, Jiaying; Breinbjerg, Olav

2009-01-01

A new folded patch antenna with multiple layers was developed in this paper, by folding the patch in a proper way, and a highly miniaturized antenna can be realized. The multiple layer patch with 4-layer and 6-layer are designed and evaluated at 2.4 GHz, 915 MHz, and 415 MHz respectively. Then a 4...... layer patch is fabricated and measured to validate the design method. The theoretical analysis, design and simulations, fabrications, as well as the measurements are presented in this paper. All the results show that the folded patch antenna is a good candidate in making a highly miniaturized compact...

Subnanometer Ga 2 O 3 Tunnelling Layer by Atomic Layer Deposition to Achieve 1.1 V Open-Circuit Potential in Dye-Sensitized Solar Cells

KAUST Repository

Chandiran, Aravind Kumar; Tetreault, Nicolas; Humphry-Baker, Robin; Kessler, Florian; Baranoff, Etienne; Yi, Chenyi; Nazeeruddin, Mohammad Khaja; Grä tzel, Michael

2012-01-01

Herein, we present the first use of a gallium oxide tunnelling layer to significantly reduce electron recombination in dye-sensitized solar cells (DSC). The subnanometer coating is achieved using atomic layer deposition (ALD) and leading to a new

Plasma opening switch for long-pulse intense ion beam

International Nuclear Information System (INIS)

Davis, H.A.; Mason, R.J.; Bartsch, R.R.; Greenly, J.B.; Rej, D.J.

1992-01-01

A Plasma Opening Switch (POS) is being developed at Los Alamos, as part of an intense ion beam experiment with special application to materials processing. The switch must conduct up to 100 kA for 600 ns, and open quickly to avoid premature gap closure in the ion beam diode load. Power multiplication is not a necessity, but prepulse suppression is. A positive central polarity is desirable, since with it an ion beam can be conveniently launched beyond the switch from the central anode toward a negatively charged target. Thus, otherwise by virtue of traditional scaling rules, a POS was designed with a 1.25 cm radius inner anode, and a 4.75 cm radius outer cathode. This has been constructed, and subjected to circuit, and simulational analysis. The computations are being performed with the 2D ANTHEM implicit code. Preliminary results show a marked difference in switching dynamics, when the central positive polarity is used in place of the more conventional opposite choice. Opening goes by the fast development of a central anode magnetic layer, rather than by the more conventional slow evolution of a cathode gap. With the central anode, higher fill densities are needed to achieve desired conduction times. This has suggested switch design improvements, which are discussed

Transport Asymmetry of Novel Bi-Layer Hybrid Perfluorinated Membranes on the Base of MF-4SC Modified by Halloysite Nanotubes with Platinum

Directory of Open Access Journals (Sweden)

Anatoly Filippov

2018-03-01

Full Text Available Three types of bi-layer hybrid nanocomposites on the base of perfluorinated cation-exchange membrane MF-4SC (Russian analogue of Nafion®-117 were synthesized and characterized. It was found that two membranes possess the noticeable asymmetry of the current–voltage curve (CVC under changing their orientation towards the applied electric field, despite the absence of asymmetry of diffusion permeability. These phenomena were explained in the frame of the “fine-porous model” expanded for bi-layer membranes. A special procedure to calculate the real values of the diffusion layers thickness and the limiting current density was proposed. Due to asymmetry effects of the current voltage curves of bi-layer hybrid membranes on the base of MF-4SC, halloysite nanotubes and platinum nanoparticles, it is prospective to assemble membrane switches (membrane relays or diodes with predictable transport properties, founded upon the theory developed here.

Diagnostic capability of optic nerve head rim width and retinal nerve fiber thickness in open-angle glaucoma.

Science.gov (United States)

Di Staso, Silvio; Agnifili, Luca; Di Staso, Federico; Climastone, Hilary; Ciancaglini, Marco; Scuderi, Gian Luca

2018-03-01

This study was performed to test the diagnostic capability of the minimum rim width compared to peripapillary retinal nerve fiber layer thickness in patients with glaucoma. A case control, observer masked study, was conducted. Minimum rim width and retinal nerve fiber layer thickness were assessed using the patient-specific axis traced between fovea-to-Bruch's membrane opening center axis. For both minimum rim width and retinal nerve fiber layer thickness, the regionalization in six sectors (nasal, superior-nasal, superior-temporal, temporal, inferior-temporal, and inferior-nasal) was analyzed. Eyes with at least one sector with value below the 5% or 1% normative limit of the optical coherence tomography normative database were classified as glaucomatous. The area under the receiver operator characteristic curve, the accuracy, sensitivity, specificity, and predictive positive and negative values were calculated for both minimum rim width and retinal nerve fiber layer thickness. A total of 118 eyes of 118 Caucasian subjects (80 eyes with open-angle glaucoma and 38 control eyes) were enrolled in the study. Accuracy, sensitivity, and specificity were 79.7%, 77.5%, and 84.2%, respectively, for minimum rim width and 84.7%, 82.5%, and 89.5% for retinal nerve fiber layer thickness. The positive predictive values were 0.91% and 0.94% for minimum rim width and retinal nerve fiber layer thickness, respectively, whereas the negative predictive values were 0.64% and 0.70%. The area under the receiver operator characteristic curve was 0.892 for minimum rim width and 0.938 for retinal nerve fiber layer thickness. Our results indicated that the sector analysis based on Bruch's membrane opening and fovea to disk alignment is able to detect glaucomatous defects, and that Bruch's membrane opening minimum rim width and retinal nerve fiber layer thickness showed equivalent diagnostic ability.

Epitaxial integration of CoFe2O4 thin films on Si (001) surfaces using TiN buffer layers

Science.gov (United States)

Prieto, Pilar; Marco, José F.; Prieto, José E.; Ruiz-Gomez, Sandra; Perez, Lucas; del Real, Rafael P.; Vázquez, Manuel; de la Figuera, Juan

2018-04-01

Epitaxial cobalt ferrite thin films with strong in-plane magnetic anisotropy have been grown on Si (001) substrates using a TiN buffer layer. The epitaxial films have been grown by ion beam sputtering using either metallic, CoFe2, or ceramic, CoFe2O4, targets. X-ray diffraction (XRD) and Rutherford spectrometry (RBS) in random and channeling configuration have been used to determine the epitaxial relationship CoFe2O4 [100]/TiN [100]/Si [100]. Mössbauer spectroscopy, in combination with XRD and RBS, has been used to determine the composition and structure of the cobalt ferrite thin films. The TiN buffer layer induces a compressive strain in the cobalt ferrite thin films giving rise to an in-plane magnetic anisotropy. The degree of in-plane anisotropy depends on the lattice mismatch between CoFe2O4 and TiN, which is larger for CoFe2O4 thin films grown on the reactive sputtering process with ceramic targets.

Long-Term, Open-Label Safety and Efficacy of Atomoxetine in Adults with ADHD: Final Report of a 4-Year Study

Science.gov (United States)

Adler, Lenard A.; Spencer, Thomas J.; Williams, David W.; Moore, Rodney J.; Michelson, David

2008-01-01

Objective: Previously, data from 97 weeks of open-label atomoxetine treatment of adults with attention-deficit/hyperactivity disorder (ADHD) were reported. This final report of that study presents results from over 4 years of treatment. Method: Results were derived from the study of 384 patients (125 patients remaining in the open-label trial…

Analysis of reaction between c+a and -c+a dislocations in GaN layer grown on 4-inch Si(111) substrate with AlGaN/AlN strained layer superlattice by transmission electron microscopy

Energy Technology Data Exchange (ETDEWEB)

Sugawara, Yoshihiro; Ishikawa, Yukari, E-mail: yukari@jfcc.or.jp [Japan Fine Ceramics Center, Atsuta, Nagoya, 456-8587 (Japan); Watanabe, Arata [Research Center for Nano Devices and Advanced Materials, Nagoya Institute of Technology, Nagoya, 466-8555 (Japan); Miyoshi, Makoto; Egawa, Takashi [Research Center for Nano Devices and Advanced Materials, Nagoya Institute of Technology, Nagoya, 466-8555 (Japan); Innovation Center for Multi-Business of Nitride Semiconductors, Nagoya Institute of Technoloy, Nagoya, 466-8555 (Japan)

2016-04-15

The behavior of dislocations in a GaN layer grown on a 4-inch Si(111) substrate with an AlGaN/AlN strained layer superlattice using horizontal metal-organic chemical vapor deposition was observed by transmission electron microscopy. Cross-sectional observation indicated that a drastic decrease in the dislocation density occurred in the GaN layer. The reaction of a dislocation (b=1/3[-211-3]) and anothor dislocation (b =1/3[-2113]) to form one dislocation (b =2/3[-2110]) in the GaN layer was clarified by plan-view observation using weak-beam dark-field and large-angle convergent-beam diffraction methods.

Organically pillared layered zinc hydroxides

International Nuclear Information System (INIS)

Kongshaug, K.O.; Fjellvaag, Helmer

2004-01-01

The two organically pillared layered zinc hydroxides [Zn 2 (OH) 2 (ndc)], CPO-6, and [Zn 3 (OH) 4 (bpdc)], CPO-7, were obtained in hydrothermal reactions between 2,6-naphthalenedicarboxylic acid (ndc) and zinc nitrate (CPO-6) and 4,4'biphenyldicarboxylate (bpdc) and zinc nitrate (CPO-7), respectively. In CPO-6, the tetrahedral zinc atoms are connected by two μ 2 -OH groups and two carboxylate oxygen atoms, forming infinite layers extending parallel to the bc-plane. These layers are pillared by ndc to form a three-dimensional structure. In CPO-7, the zinc hydroxide layers are containing four-, five- and six coordinated zinc atoms, and the layers are built like stairways running along the [001] direction. Each step is composed of three infinite chains running in the [010] direction. Both crystal structures were solved from conventional single crystal data. Crystal data for CPO-6: Monoclinic space group P2 1 /c (No. 14), a=11.9703(7), b=7.8154(5), c=6.2428(4) A, β=90.816(2) deg., V=583.97(6) A 3 and Z=4. Crystal data for CPO-7: Monoclinic space group C2/c (No. 15), a=35.220(4), b=6.2658(8), c=14.8888(17) A, β=112.580(4) deg., V=3033.8(6) A 3 and Z=8. The compounds were further characterized by thermogravimetric- and chemical analysis

Dynamic lift on an artificial static armor layer during highly unsteady open channel flow

OpenAIRE

Spiller, Stephan Mark; Ruther, Nils; Friedrich, Heide

2015-01-01

The dynamic lift acting on a 100 mm × 100 mm section of a static armor layer during unsteady flow is directly measured in a series of physical experiments. The static armor layer is represented by an artificial streambed mold, made from an actual gravel bed. Data from a total of 190 experiments are presented, undertaken in identical conditions. Results show that during rapid discharge increases, the dynamic lift on the streambed repeatedly exhibits three clear peaks. The magnitude of the obse...

Multiferroic properties of BiFeO3/Bi4Ti3O12 double-layered thin films fabricated by chemical solution deposition

International Nuclear Information System (INIS)

Yi, Seung Woo; Kim, Sang Su; Kim, Jin Won; Jo, Hyun Kyung; Do, Dalhyun; Kim, Won-Jeong

2009-01-01

Multiferroic BiFeO 3 /Bi 4 Ti 3 O 12 (BFO/BTO) double-layered film was fabricated on a Pt(111)/Ti/SiO 2 /Si(100) substrate by a chemical solution deposition method. The effect of an interfacial BTO layer on electrical and magnetic properties of BFO was investigated by comparing those of pure BFO and BTO films prepared by the same condition. The X-ray diffraction result showed that no additional phase was formed in the double-layered film, except BFO and BTO phases. The remnant polarization (2P r ) of the double-layered film capacitor was 100 μC/cm 2 at 250 kV/cm, which is much larger than that of the pure BFO film capacitor. The magnetization-magnetic field hysteresis loop revealed weak ferromagnetic response with remnant magnetization (2M r ) of 0.4 kA/m. The values of dielectric constant and dielectric loss of the double-layered film capacitor were 240 and 0.03 at 100 kHz, respectively. Leakage current density measured from the double-layered film capacitor was 6.1 x 10 -7 A/cm 2 at 50 kV/cm, which is lower than the pure BFO and BTO film capacitors.

Improvement in IBC-silicon solar cell performance by insertion of highly doped crystalline layer at heterojunction interfaces

International Nuclear Information System (INIS)

Bashiri, Hadi; Azim Karami, Mohammad; Mohammadnejad, Shahramm

2017-01-01

By inserting a thin highly doped crystalline silicon layer between the base region and amorphous silicon layer in an interdigitated back-contact (IBC) silicon solar cell, a new passivation layer is investigated. The passivation layer performance is characterized by numerical simulations. Moreover, the dependence of the output parameters of the solar cell on the additional layer parameters (doping concentration and thickness) is studied. By optimizing the additional passivation layer in terms of doping concentration and thickness, the power conversion efficiency could be improved by a factor of 2.5%, open circuit voltage is increased by 30 mV and the fill factor of the solar cell by 7.4%. The performance enhancement is achieved due to the decrease of recombination rate, a decrease in solar cell resistivity and improvement of field effect passivation at heterojunction interface. The above-mentioned results are compared with reported results of the same conventional interdigitated back-contact silicon solar cell structure. Furthermore, the effect of a-Si:H/c-Si interface defect density on IBC silicon solar cell parameters with a new passivation layer is studied. The additional passivation layer also reduces the sensitivity of output parameter of solar cell to interface defect density. (paper)

Gastroesophageal anastomosis: single-layer versus double-layer technique

International Nuclear Information System (INIS)

Aslam, V.A.; Bilal, A.; Khan, A.; Ahmed, M.

2008-01-01

Considerable controversy exists regarding the optimum technique for gastroesophageal anastomosis. Double layer technique has long been considered important for safe healing but there is evidence that single layer technique is also safe and can be performed in much shorter time. The purpose of this study was to compare the outcome of single layer and double layer techniques for gastroesophageal anastomosis. A prospective randomized study was conducted in cardiothoracic unit, Lady Reading Hospital from Jan 2006 to Jan 2008. Fifty patients with oesophageal carcinoma undergoing subtotal oesophagectomy were randomized to have the anastomosis by single layer continuous or double layer continuous technique (group A (n=24) and B (n=26) respectively). The demographic data, operative and anastomosis time, postoperative complications and hospital mortality were recorded on a proforma and analyzed on SPSS 10. There was no significant difference between group A and B in terms of age, gender, postoperative complications and duration of hospital stay. Anastomotic leak occurred in 4.2% patients in group A and 7.7% in group B (p=NS). Mean anastomosis time was 10.04 minutes in group A and 19.2 minutes in group B (p=0.0001). Mean operative time was 163.83 minutes and 170.96 minutes in group A and B respectively. Overall hospital mortality was 2%; no deaths occurred due to anastomotic leak. Single layer continuous technique is equally safe and can be performed in shorter time and at a lower cost than the double layer technique. (author)

Ln{sup 3+}:KLu(WO{sub 4}){sub 2}/KLu(WO{sub 4}){sub 2} epitaxial layers: Crystal growth and physical characterisation

Energy Technology Data Exchange (ETDEWEB)

Silvestre, O.; Pujol, M.C.; Sole, R.; Bolanos, W.; Carvajal, J.J.; Massons, J.; Aguilo, M. [Fisica i Cristal.lografia de Materials (FiCMA), Universitat Rovira i Virgili, Campus Sescelades c/Marcel.li Domingo, s/n E-43007 Tarragona (Spain); Diaz, F. [Fisica i Cristal.lografia de Materials (FiCMA), Universitat Rovira i Virgili, Campus Sescelades c/Marcel.li Domingo, s/n E-43007 Tarragona (Spain)], E-mail: f.diaz@urv.cat

2008-01-15

Monoclinic epitaxial layers of single doped KLu{sub 1-x}Ln{sub x}(WO{sub 4}){sub 2} (Ln{sup 3+} = Yb{sup 3+} and Tm{sup 3+}) have been grown on optically passive KLuW substrates by liquid phase epitaxy (LPE) technique using K{sub 2}W{sub 2}O{sub 7} as solvent. The ytterbium content in the layer is in the range of 0.05 < x < 0.75 atomic substitution and the studied thulium concentrations are 0.05 < x < 0.10. The grown epitaxies are free of macroscopic defects and only in highly ytterbium-doped epilayers do some cracks or inclusions appear. The refractive indices of the epilayers were determined. The absorption and emission cross sections of ytterbium and thulium in KLuW are characterised and laser generation results are presented and discussed.

TiO{sub 2} nanofiber solid-state dye sensitized solar cells with thin TiO{sub 2} hole blocking layer prepared by atomic layer deposition

Energy Technology Data Exchange (ETDEWEB)

Li, Jinwei; Chen, Xi; Xu, Weihe [Department of Mechanical Engineering, Stevens Institute of Technology, Hoboken, NJ 07030 (United States); Nam, Chang-Yong, E-mail: cynam@bnl.gov [Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY 11973 (United States); Shi, Yong, E-mail: Yong.Shi@stevens.edu [Department of Mechanical Engineering, Stevens Institute of Technology, Hoboken, NJ 07030 (United States)

2013-06-01

We incorporated a thin but structurally dense TiO{sub 2} layer prepared by atomic layer deposition (ALD) as an efficient hole blocking layer in the TiO{sub 2} nanofiber based solid-state dye sensitized solar cell (ss-DSSC). The nanofiber ss-DSSCs having ALD TiO{sub 2} layers displayed increased open circuit voltage, short circuit current density, and power conversion efficiency compared to control devices with blocking layers prepared by spin-coating liquid TiO{sub 2} precursor. We attribute the improved photovoltaic device performance to the structural integrity of ALD-coated TiO{sub 2} layer and consequently enhanced hole blocking effect that results in reduced dark leakage current and increased charge carrier lifetime. - Highlights: • TiO{sub 2} blocking locking layer prepared by atomic layer deposition (ALD) method. • ALD-coated TiO{sub 2} layer enhanced hole blocking effect. • ALD blocking layer improved the voltage, current and efficiency. • ALD blocking layer reduced dark leakage current and increased electron lifetime.

Layer-by-layer assembly of graphene oxide on polypropylene macroporous membranes via click chemistry to improve antibacterial and antifouling performance

Energy Technology Data Exchange (ETDEWEB)

Zhang, Zhen-Bei, E-mail: 1021453457@qq.com [The Key Laboratory of Functional Molecular Solids, Ministry of Education, Anhui Key Laboratory of Molecular-Based Materials, College of Chemistry and Materials Science, Anhui Normal University, East Beijing Rd. 1, Wuhu, Anhui 241000 (China); Wu, Jing-Jing, E-mail: 957522275@qq.com [The Key Laboratory of Functional Molecular Solids, Ministry of Education, Anhui Key Laboratory of Molecular-Based Materials, College of Chemistry and Materials Science, Anhui Normal University, East Beijing Rd. 1, Wuhu, Anhui 241000 (China); Su, Yu, E-mail: 819388710@qq.com [The Key Laboratory of Functional Molecular Solids, Ministry of Education, Anhui Key Laboratory of Molecular-Based Materials, College of Chemistry and Materials Science, Anhui Normal University, East Beijing Rd. 1, Wuhu, Anhui 241000 (China); Zhou, Jin, E-mail: zhoujin_ah@163.com [Department of Materials and Chemical Engineering, Chizhou University, Muzhi Rd. 199, Chizhou, Anhui 247000 (China); Gao, Yong, E-mail: 154682180@qq.com [School of Chemistry and Environmental Engineering, Jiangsu University of Technology, Changzhou 213001 (China); Yu, Hai-Yin, E-mail: yhy456@mail.ahnu.edu.cn [The Key Laboratory of Functional Molecular Solids, Ministry of Education, Anhui Key Laboratory of Molecular-Based Materials, College of Chemistry and Materials Science, Anhui Normal University, East Beijing Rd. 1, Wuhu, Anhui 241000 (China); Gu, Jia-Shan, E-mail: jiashanG@mail.ahnu.edu.cn [The Key Laboratory of Functional Molecular Solids, Ministry of Education, Anhui Key Laboratory of Molecular-Based Materials, College of Chemistry and Materials Science, Anhui Normal University, East Beijing Rd. 1, Wuhu, Anhui 241000 (China)

2015-03-30

Graphical abstract: - Highlights: • Clickable membrane prepared by photo bromination and S{sub N}2 nucleophilic substitution. • Azide graphene oxide prepared by ring-opening reaction. • Alkyne graphene oxide was prepared via esterification reaction. • Layer-by-layer assembly of graphene oxide on membrane by click chemistry. • Antibacterial and antifouling characteristics were enhanced greatly. - Abstract: Polypropylene is an extensively used membrane material; yet, polypropylene membranes exhibit extremely poor resistance to protein fouling. To ameliorate this issue, graphene oxide (GO) nanosheets were used to modify macroporous polypropylene membrane (MPPM) via layer-by-layer assembly technique through click reaction. First, alkyne-terminated GO was prepared through esterification between carboxyl groups in GO and amide groups in propargylamine; azide-terminated GO was synthesized by the ring-opening reaction of epoxy groups in GO with sodium azide. Second, GO was introduced to the membrane by click chemistry. Characterizations of infrared spectra and X-ray photoelectron spectroscopy confirmed the modification. The sharply decreasing of static water contact angle indicated the improvement of the surface hydrophilicity for GO modified membrane. Introducing GO to the membrane results in a dramatic increase of water flux, improvements in the antifouling characteristics and antibacterial property for the membranes. The pure water flux through the 5-layered GO modified membrane is 1.82 times that through the unmodified one. The water flux restores to 43.0% for the unmodified membrane while to 79.8% for the modified membrane. The relative flux reduction decreases by 32.1% due to GO modification. The antibacterial property was also enhanced by two-thirds. These results demonstrate that the antifouling and antibacterial characteristics can be raised by tethering GO to the membrane surface.

Layer-by-layer assembly of graphene oxide on polypropylene macroporous membranes via click chemistry to improve antibacterial and antifouling performance

International Nuclear Information System (INIS)

Zhang, Zhen-Bei; Wu, Jing-Jing; Su, Yu; Zhou, Jin; Gao, Yong; Yu, Hai-Yin; Gu, Jia-Shan

2015-01-01

Graphical abstract: - Highlights: • Clickable membrane prepared by photo bromination and S N 2 nucleophilic substitution. • Azide graphene oxide prepared by ring-opening reaction. • Alkyne graphene oxide was prepared via esterification reaction. • Layer-by-layer assembly of graphene oxide on membrane by click chemistry. • Antibacterial and antifouling characteristics were enhanced greatly. - Abstract: Polypropylene is an extensively used membrane material; yet, polypropylene membranes exhibit extremely poor resistance to protein fouling. To ameliorate this issue, graphene oxide (GO) nanosheets were used to modify macroporous polypropylene membrane (MPPM) via layer-by-layer assembly technique through click reaction. First, alkyne-terminated GO was prepared through esterification between carboxyl groups in GO and amide groups in propargylamine; azide-terminated GO was synthesized by the ring-opening reaction of epoxy groups in GO with sodium azide. Second, GO was introduced to the membrane by click chemistry. Characterizations of infrared spectra and X-ray photoelectron spectroscopy confirmed the modification. The sharply decreasing of static water contact angle indicated the improvement of the surface hydrophilicity for GO modified membrane. Introducing GO to the membrane results in a dramatic increase of water flux, improvements in the antifouling characteristics and antibacterial property for the membranes. The pure water flux through the 5-layered GO modified membrane is 1.82 times that through the unmodified one. The water flux restores to 43.0% for the unmodified membrane while to 79.8% for the modified membrane. The relative flux reduction decreases by 32.1% due to GO modification. The antibacterial property was also enhanced by two-thirds. These results demonstrate that the antifouling and antibacterial characteristics can be raised by tethering GO to the membrane surface

Bismuth-doped Cu(In,Ga)Se{sub 2} absorber prepared by multi-layer precursor method and its solar cell

Energy Technology Data Exchange (ETDEWEB)

Chantana, Jakapan; Hironiwa, Daisuke; Minemoto, Takashi [Department of Electrical and Electronic Engineering, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu, Shiga 525-8577 (Japan); Watanabe, Taichi; Teraji, Seiki; Kawamura, Kazunori [Environment and Energy Research Center, Nitto Denko Corporation, 2-8 Yamadaoka, Suita, Osaka 565-0871 (Japan)

2015-06-15

Bismuth (Bi)-doped Cu(In,Ga)Se{sub 2} (CIGS) films were prepared by the so-called ''multi-layer precursor method'', obtained by depositing them onto Bi layers with various thicknesses on Mo-coated soda-lime glass (SLG) substrates. Material composition (Cu, In, Ga, and Se) profiles of the CIGS films are almost identical, whereas sodium (Na) is reduced, when Bi thickness is increased. Moreover, the incorporation of Bi into the CIGS film is enhanced with thicker Bi layer. With Bi thickness from 0 to 70 nm, the 2.4-μm-thick CIGS absorbers demonstrate the increase in CIGS grain size, carrier lifetime, and carrier concentration, thus improving their cell performances, especially open-circuit voltage (V{sub OC}). With further increase in Bi thickness of above 70 nm, the CIGS films show the deterioration of CIGS film quality owing to the formation of Bi compounds such as Bi, BiSe, and Bi{sub 4}Se{sub 3}. Consequently, Bi-doped CIGS absorber with thickness of 2.4 μm, prepared with the 70-nm-thick Bi layer on Mo-coated SLG substrate, gives rise to the improvement of photovoltaic performances, especially V{sub OC}. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Characterization of Ti-6Al-4V open cellular foams fabricated by additive manufacturing using electron beam melting

International Nuclear Information System (INIS)

Murr, L.E.; Gaytan, S.M.; Medina, F.; Martinez, E.; Martinez, J.L.; Hernandez, D.H.; Machado, B.I.; Ramirez, D.A.; Wicker, R.B.

2010-01-01

Ti-6Al-4V open cellular foams were fabricated by additive manufacturing using electron beam melting (EBM). Foam models were developed from CT-scans of aluminum open cellular foams and embedded in CAD for EBM. These foams were fabricated with solid cell structures as well as hollow cell structures and exhibit tailorable stiffness and strength. The strength in proportion to the measured microindentation hardness is as much as 40% higher for hollow cell (wall) structures in contrast to solid, fully dense EBM fabricated components. Plots of relative stiffness versus relative density were in good agreement with the Gibson-Ashby model for open cellular foam materials. Stiffness or Young's modulus values measured using a resonant frequency-damping analysis technique were found to vary inversely with porosity especially for solid cell wall, open cellular structure foams. These foams exhibit the potential for novel biomedical, aeronautics, and automotive applications.

Open Polar Server (OPS—An Open Source Infrastructure for the Cryosphere Community

Directory of Open Access Journals (Sweden)

Weibo Liu

2016-03-01

Full Text Available The Center for Remote Sensing of Ice Sheets (CReSIS at the University of Kansas has collected approximately 1000 terabytes (TB of radar depth sounding data over the Arctic and Antarctic ice sheets since 1993 in an effort to map the thickness of the ice sheets and ultimately understand the impacts of climate change and sea level rise. In addition to data collection, the storage, management, and public distribution of the dataset are also primary roles of the CReSIS. The Open Polar Server (OPS project developed a free and open source infrastructure to store, manage, analyze, and distribute the data collected by CReSIS in an effort to replace its current data storage and distribution approach. The OPS infrastructure includes a spatial database management system (DBMS, map and web server, JavaScript geoportal, and MATLAB application programming interface (API for the inclusion of data created by the cryosphere community. Open source software including GeoServer, PostgreSQL, PostGIS, OpenLayers, ExtJS, GeoEXT and others are used to build a system that modernizes the CReSIS data distribution for the entire cryosphere community and creates a flexible platform for future development. Usability analysis demonstrates the OPS infrastructure provides an improved end user experience. In addition, interpolating glacier topography is provided as an application example of the system.

Layer-dependent band alignment and work function of few-layer phosphorene.

Science.gov (United States)

Cai, Yongqing; Zhang, Gang; Zhang, Yong-Wei

2014-10-20

Using first-principles calculations, we study the electronic properties of few-layer phosphorene focusing on layer-dependent behavior of band gap, work function band alignment and carrier effective mass. It is found that few-layer phosphorene shows a robust direct band gap character, and its band gap decreases with the number of layers following a power law. The work function decreases rapidly from monolayer (5.16 eV) to trilayer (4.56 eV), and then slowly upon further increasing the layer number. Compared to monolayer phosphorene, there is a drastic decrease of hole effective mass along the ridge (zigzag) direction for bilayer phosphorene, indicating a strong interlayer coupling and screening effect. Our study suggests that 1). Few-layer phosphorene with a layer-dependent band gap and a robust direct band gap character is promising for efficient solar energy harvest. 2). Few-layer phosphorene outperforms monolayer counterpart in terms of a lighter carrier effective mass, a higher carrier density and a weaker scattering due to enhanced screening. 3). The layer-dependent band edges and work functions of few-layer phosphorene allow for modification of Schottky barrier with enhanced carrier injection efficiency. It is expected that few-layer phosphorene will present abundant opportunities for a plethora of new electronic applications.

The importance of dye chemistry and TiCl4 surface treatment in the behavior of Al2O3 recombination barrier layers deposited by atomic layer deposition in solid-state dye-sensitized solar cells

KAUST Repository

Brennan, Thomas P.

2012-01-01

Atomic layer deposition (ALD) was used to fabricate Al 2O 3 recombination barriers in solid-state dye-sensitized solar cells (ss-DSSCs) employing an organic hole transport material (HTM) for the first time. Al 2O 3 recombination barriers of varying thickness were incorporated into efficient ss-DSSCs utilizing the Z907 dye adsorbed onto a 2 μm-thick nanoporous TiO 2 active layer and the HTM spiro-OMeTAD. The impact of Al 2O 3 barriers was also studied in devices employing different dyes, with increased active layer thicknesses, and with substrates that did not undergo the TiCl 4 surface treatment. In all instances, electron lifetimes (as determined by transient photovoltage measurements) increased and dark current was suppressed after Al 2O 3 deposition. However, only when the TiCl 4 treatment was eliminated did device efficiency increase; in all other instances efficiency decreased due to a drop in short-circuit current. These results are attributed in the former case to the similar effects of Al 2O 3 ALD and the TiCl 4 surface treatment whereas the insulating properties of Al 2O 3 hinder charge injection and lead to current loss in TiCl 4-treated devices. The impact of Al 2O 3 barrier layers was unaffected by doubling the active layer thickness or using an alternative ruthenium dye, but a metal-free donor-π-acceptor dye exhibited a much smaller decrease in current due to its higher excited state energy. We develop a model employing prior research on Al 2O 3 growth and dye kinetics that successfully predicts the reduction in device current as a function of ALD cycles and is extendable to different dye-barrier systems. © This journal is the Owner Societies 2012.

Computing OpenSURF on OpenCL and General Purpose GPU

Directory of Open Access Journals (Sweden)

Wanglong Yan

2013-10-01

Full Text Available Speeded-Up Robust Feature (SURF algorithm is widely used for image feature detecting and matching in computer vision area. Open Computing Language (OpenCL is a framework for writing programs that execute across heterogeneous platforms consisting of CPUs, GPUs, and other processors. This paper introduces how to implement an open-sourced SURF program, namely OpenSURF, on general purpose GPU by OpenCL, and discusses the optimizations in terms of the thread architectures and memory models in detail. Our final OpenCL implementation of OpenSURF is on average 37% and 64% faster than the OpenCV SURF v2.4.5 CUDA implementation on NVidia's GTX660 and GTX460SE GPUs, repectively. Our OpenCL program achieved real-time performance (>25 Frames Per Second for almost all the input images with different sizes from 320*240 to 1024*768 on NVidia's GTX660 GPU, NVidia's GTX460SE GPU and AMD's Radeon HD 6850 GPU. Our OpenCL approach on NVidia's GTX660 GPU is more than 22.8 times faster than its original CPU version on Intel's Dual-Core E5400 2.7G on average.

Bonded Multilayer Laue Lens for focusing hard X-rays

International Nuclear Information System (INIS)

Liu Chian; Conley, R.; Qian, J.; Kewish, C.M.; Macrander, A.T.; Maser, J.; Kang, H.C.; Yan, H.; Stephenson, G.B.

2007-01-01

We have fabricated partial Multilayer Laue Lens (MLL) linear zone plate structures with thousands of alternating WSi 2 and Si layers and various outermost zone widths according to the Fresnel zone plate formula. Using partial MLL structures, we were able to focus hard X-rays to line foci with a width of 30 nm and below. Here, we describe challenges and approaches used to bond these multilayers to achieve line and point focusing. Bonding was done by coating two multilayers with AuSn and heating in a vacuum oven at 280-300 o C. X-ray reflectivity measurements confirmed that there was no change in the multilayers after heating to 350 o C. A bonded MLL was polished to a 5-25 μm wedge without cracking. SEM image analyses found well-positioned multilayers after bonding. These results demonstrate the feasibility of a bonded full MLL for focusing hard X-rays

Syntheses, structural variants and characterization of AInM′S{sub 4} (A=alkali metals, Tl; M′ = Ge, Sn) compounds; facile ion-exchange reactions of layered NaInSnS{sub 4} and KInSnS{sub 4} compounds

Energy Technology Data Exchange (ETDEWEB)

Yohannan, Jinu P.; Vidyasagar, Kanamaluru, E-mail: kvsagar@iitm.ac.in

2016-06-15

Ten AInM′S{sub 4} (A=alkali metals, Tl; M′= Ge, Sn) compounds with diverse structure types have been synthesized and characterized by single crystal and powder X-ray diffraction and a variety of spectroscopic methods. They are wide band gap semiconductors. KInGeS{sub 4}(1-β), RbInGeS{sub 4}(2), CsInGeS{sub 4}(3-β), TlInGeS{sub 4}(4-β), RbInSnS{sub 4}(8-β) and CsInSnS{sub 4}(9) compounds with three-dimensional BaGa{sub 2}S{sub 4} structure and CsInGeS{sub 4}(3-α) and TlInGeS{sub 4}(4-α) compounds with a layered TlInSiS{sub 4} structure have tetrahedral [InM′S{sub 4}]{sup −} frameworks. On the other hand, LiInSnS{sub 4}(5) with spinel structure and NaInSnS{sub 4}(6), KInSnS{sub 4}(7), RbInSnS{sub 4}(8-α) and TlInSnS{sub 4}(10) compounds with layered structure have octahedral [InM′S{sub 4}]{sup −} frameworks. NaInSnS{sub 4}(6) and KInSnS{sub 4}(7) compounds undergo facile topotactic ion-exchange, at room temperature, with various mono-, di- and tri-valent cations in aqueous medium to give rise to metastable layered phases. - Graphical abstract: NaInSnS{sub 4} and KInSnS{sub 4} compounds undergo, in aqueous medium at room temperature, facile topotactic ion-exchange with mono, di and trivalent cations. Display Omitted - Highlights: • Ten AInM′S{sub 4} compounds with diverse structure types were synthesized. • They are wide band gap semiconductors. • NaInSnS{sub 4} and KInSnS{sub 4} compounds undergo facile topotactic ion-exchange at room temperature.

Recombination barrier layers in solid-state quantum dot-sensitized solar cells

KAUST Repository

Roelofs, Katherine E.

2012-06-01

By replacing the dye in the dye-sensitized solar cell design with semiconductor quantum dots as the light-absorbing material, solid-state quantum dot-sensitized solar cells (ss-QDSSCs) were fabricated. Cadmium sulfide quantum dots (QDs) were grown in situ by successive ion layer adsorption and reaction (SILAR). Aluminum oxide recombination barrier layers were deposited by atomic layer deposition (ALD) at the TiO2/hole-conductor interface. For low numbers of ALD cycles, the Al2O3 barrier layer increased open circuit voltage, causing an increase in device efficiency. For thicker Al2O3 barrier layers, photocurrent decreased substantially, leading to a decrease in device efficiency. © 2012 IEEE.

SEM and XPS study of layer-by-layer deposited polypyrrole thin films

Science.gov (United States)

Pigois-Landureau, E.; Nicolau, Y. F.; Delamar, M.

1996-01-01

Layer-by-layer deposition of thin films (a few nm) of polypyrrole was carried out on various substrates such as silver, platinum, electrochemically oxidized aluminum and pretreated glass. SEM micrographs showed that the deposited layers nucleate by an island-type mechanism on hydrated alumina and KOH-pretreated (hydrophilic) glass before forming a continuous film. However, continuous thin films are obtained on chromic acid pretreated (hydrophobic) glass and sputtered Ag or Pt on glass after only 3-4 deposition cycles. The mean deposition rate evaluated by XPS for the first deposition cycles on Ag and Pt is 3 and 4 nm/cycle, respectively, in agreement with previous gravimetric determinations on thicker films, proving the constancy of the deposition rate. The XPS study of the very thin films obtained by a few deposition cycles shows that the first polypyrrole layers are dedoped by hydroxydic (basic) substrate surfaces.

Structural and elemental characterization of high efficiency Cu2ZnSnS4 solar cells

Science.gov (United States)

Wang, Kejia; Shin, Byungha; Reuter, Kathleen B.; Todorov, Teodor; Mitzi, David B.; Guha, Supratik

2011-01-01

We have carried out detailed microstructural studies of phase separation and grain boundary composition in Cu2ZnSnS4 based solar cells. The absorber layer was fabricated by thermal evaporation followed by post high temperature annealing on hot plate. We show that inter-reactions between the bottom molybdenum and the Cu2ZnSnS4, besides triggering the formation of interfacial MoSx, results in the out-diffusion of Cu from the Cu2ZnSnS4 layer. Phase separation of Cu2ZnSnS4 into ZnS and a Cu-Sn-S compound is observed at the molybdenum-Cu2ZnSnS4 interface, perhaps as a result of the compositional out-diffusion. Additionally, grain boundaries within the thermally evaporated absorber layer are found to be either Cu-rich or at the expected bulk composition. Such interfacial compound formation and grain boundary chemistry likely contributes to the lower than expected open circuit voltages observed for the Cu2ZnSnS4 devices.

Three-layered radio frequency coil arrangement for sodium MRI of the human brain at 9.4 Tesla.

Science.gov (United States)

Shajan, G; Mirkes, Christian; Buckenmaier, Kai; Hoffmann, Jens; Pohmann, Rolf; Scheffler, Klaus

2016-02-01

A multinuclei imaging setup with the capability to acquire both sodium ((23) Na) and proton ((1) H) signals at 9.4 Tesla is presented. The main objective was to optimize coil performance at the (23) Na frequency while still having the ability to acquire satisfactory (1) H images. The setup consisted of a combination of three radio frequency (RF) coils arranged in three layers: the innermost layer was a 27-channel (23) Na receive helmet which was surrounded by a four-channel (23) Na transceiver array. The outer layer consisted of a four-channel (1) H dipole array for B0 shimming and anatomical localization. Transmit and receive performance of the (23) Na arrays was compared to a single-tuned (23) Na birdcage resonator. While the transmit efficiency of the (23) Na transceiver array was comparable to the birdcage, the (23) Na receive array provided substantial signal-to-noise ratio (SNR) gain near the surface and comparable SNR in the center. The utility of this customized setup was demonstrated by (23) Na images of excellent quality. High SNR, efficient transmit excitation and B0 shimming capability can be achieved for (23) Na MRI at 9.4T using novel coil combination. This RF configuration is easily adaptable to other multinuclei applications at ultra high field (≥ 7T). © 2015 Wiley Periodicals, Inc.

Fabrication of GaN epitaxial thin film on InGaZnO4 single-crystalline buffer layer

International Nuclear Information System (INIS)

Shinozaki, Tomomasa; Nomura, Kenji; Katase, Takayoshi; Kamiya, Toshio; Hirano, Masahiro; Hosono, Hideo

2010-01-01

Epitaxial (0001) films of GaN were grown on (111) YSZ substrates using single-crystalline InGaZnO 4 (sc-IGZO) lattice-matched buffer layers by molecular beam epitaxy with a NH 3 source. The epitaxial relationships are (0001) GaN //(0001) IGZO //(111) YSZ in out-of-plane and [112-bar 0] GaN //[112-bar 0] IGZO //[11-bar 0] YSZ in in-plane. This is different from those reported for GaN on many oxide crystals; the in-plane orientation of GaN crystal lattice is rotated by 30 o with respect to those of oxide substrates except for ZnO. Although these GaN films showed relatively large tilting and twisting angles, which would be due to the reaction between GaN and IGZO, the GaN films grown on the sc-IGZO buffer layers exhibited stronger band-edge photoluminescence than GaN grown on a low-temperature GaN buffer layer.

InP:Fe Photoconducting device

Science.gov (United States)

Hammond, Robert B.; Paulter, Nicholas G.; Wagner, Ronald S.

1984-01-01

A photoconducting device fabricated from Fe-doped, semi-insulating InP crystals exhibits an exponential decay transient with decay time inversely related to Fe concentration. Photoconductive gain as high as 5 is demonstrated in photoconducting devices with AuGe and AuSn contacts. Response times from 150 to 1000 picoseconds can be achieved.

Consecutively spin-assembled layered nanoarchitectures of poly(sodium 4-styrene sulfonate) and poly(allylamine hydrochloride)

International Nuclear Information System (INIS)

An, Minshi; Hong, Jong-Dal

2006-01-01

The recently established spin-coating electrostatic self-assembly (SCESA) technique has been shown to facilitate not only the rapid fabrication of polyelectrolyte multilayer assemblies, but also allow each layer to be easily controlled on a monomolecular scale by minimizing the film thickness across a substrate surface. In this paper, the influence of polyelectrolyte concentration on the amount and thickness of spin-deposited polymer films has been examined for a multilayer system of poly(allyamine hydrochloride) (PAH) and poly(sodium 4-styrenesulfonate) (PSS), when the washing steps employed for removing weakly bound polyelectrolytes on a resultant film on a substrate are excluded from the standard fabrication procedure of the SCESA method. The thickness of the spin-deposited PAH/PSS bilayer increased linearly for the PSS concentrations in the range from 1 to 10 mM with PAH constant at 1 mM, which demonstrates the uniform deposition of each layer material onto the thin film. The thickness of PAH/PSS bilayers increased from 1.43 ± 0.06 to 3.37 ± 0.08 nm as the PSS concentration increased from 1 to 10 mM, while the PAH concentration was kept constant at 1 mM. The multilayer films were found to be stable in a good solvent (H 2 O) for at least 30 h, without any noticeable loss of the adsorbed layer component of the polyelectrolyte. This improvement to the SCESA method (exclusion of washing steps) provides a convenient way to create multilayer heterostructures with the thickness of each layer being easily adjusted

Hybrid solar cells based on CuInS2 and organic buffer-sensitizer layers

International Nuclear Information System (INIS)

Bereznev, S.; Koeppe, R.; Konovalov, I.; Kois, J.; Guenes, S.; Opik, A.; Mellikov, E.; Sariciftci, N.S.

2007-01-01

Hybrid solar cells on the basis of CuInS 2 (CIS) photoabsorber on Cu-tape (CISCuT) in combination with organic buffer layers of Zn-phthalocyanine (ZnPc), ZnPc:fullerene (ZnPc:C 60 ) composite and conductive polymer buffer layers of poly(3,4-ethylenedioxythiophene) (PEDOT) doped with polystyrenesulfonate (PSS) were prepared using vacuum evaporation and spin-casting techniques. To prepare solar cells with an active area of 2 cm 2 , the appropriate deposition parameters and thickness of ZnPc, ZnPc:C 60 and PEDOT-PSS layers were selected experimentally. For preparation of semitransparent contact-window layers, chromium and gold were evaporated on the surface of ZnPc, ZnPc:C 60 and PEDOT-PSS films. It was found that an intermediate chromium layer improves PV properties of the structures with organic buffer layers. The photosensitivity at small illumination intensities of complete structures with ZnPc and ZnPc:C 60 layers increased more than one order of magnitude in comparison with the structures where the PEDOT-PSS buffer layer was deposited. The presence of C 60 in the composite-buffer layer results in increased photoconductivity. The best structure with composite ZnPc:C 60 buffer layer showed an open-circuit voltage of 560 mV, a short-circuit current density of around 10 mA/cm 2 and a photoconversion efficiency of around 3.3% under the light illumination with an intensity of 100 mW/cm 2 from a tungsten-halogen lamp. The low transmission of the semitransparent chromium-gold window layer is the reason for relatively low current density

Fluorescence-tracking of activation gating in human ERG channels reveals rapid S4 movement and slow pore opening.

Directory of Open Access Journals (Sweden)

Zeineb Es-Salah-Lamoureux

2010-05-01

Full Text Available hERG channels are physiologically important ion channels which mediate cardiac repolarization as a result of their unusual gating properties. These are very slow activation compared with other mammalian voltage-gated potassium channels, and extremely rapid inactivation. The mechanism of slow activation is not well understood and is investigated here using fluorescence as a direct measure of S4 movement and pore opening.Tetramethylrhodamine-5-maleimide (TMRM fluorescence at E519 has been used to track S4 voltage sensor movement, and channel opening and closing in hERG channels. Endogenous cysteines (C445 and C449 in the S1-S2 linker bound TMRM, which caused a 10 mV hyperpolarization of the V((1/2 of activation to -27.5+/-2.0 mV, and showed voltage-dependent fluorescence signals. Substitution of S1-S2 linker cysteines with valines allowed unobstructed recording of S3-S4 linker E519C and L520C emission signals. Depolarization of E519C channels caused rapid initial fluorescence quenching, fit with a double Boltzmann relationship, F-V(ON, with V((1/2 (,1 = -37.8+/-1.7 mV, and V((1/2 (,2 = 43.5+/-7.9 mV. The first phase, V((1/2 (,1, was approximately 20 mV negative to the conductance-voltage relationship measured from ionic tail currents (G-V((1/2 = -18.3+/-1.2 mV, and relatively unchanged in a non-inactivating E519C:S620T mutant (V((1/2 = -34.4+/-1.5 mV, suggesting the fast initial fluorescence quenching tracked S4 voltage sensor movement. The second phase of rapid quenching was absent in the S620T mutant. The E519C fluorescence upon repolarization (V((1/2 = -20.6+/-1.2, k = 11.4 mV and L520C quenching during depolarization (V((1/2 = -26.8+/-1.0, k = 13.3 mV matched the respective voltage dependencies of hERG ionic tails, and deactivation time constants from -40 to -110 mV, suggesting they detected pore-S4 rearrangements related to ionic current flow during pore opening and closing.THE DATA INDICATE: 1 that rapid environmental changes occur at the

Cr-substituted LiCoPO4 core with a conductive carbon layer towards high-voltage lithium-ion batteries

Science.gov (United States)

Wang, Yue; Chen, Junhong; Qiu, Jingyi; Yu, Zhongbao; Ming, Hai; Li, Meng; Zhang, Songtong; Yang, Yusheng

2018-02-01

Electrical and ionic conductivity are two major limiting factors for LiCoPO4 cathode material. To overcome these shortcomings, a Cr-substituted LiCoPO4 core with a conductive carbon layer cathode material is synthesized using the sol-gel method. The physical chemistry properties of these materials are systematically investigated by using various characterization methods. For instance, the XRD and Rietveld refinement results reveal that Cr successfully substitutes the Co within the LiCoPO4 core to form LiCo1-1.5xCrxPO4/C (x = 0, 0.02, 0.04, 0.06) without changing the olivine structure but exhibits a decrease in the unit cell volume with increasing Cr substitution. SEM and TEM images indicate that Cr substitution does not lead to changes in the basic morphology of LiCo1-1.5xCrxPO4/C (x = 0, 0.02, 0.04, 0.06) material, which is composed of agglomerated nanoparticles with an 8 nm carbon layer on the surface. The EDS and XPS results confirm that Cr is uniformly distributed on the surface and that the oxidation state of Cr is +3. FTIR spectra indicate that the antisite defect concentration decreases with increasing Cr substitution. Furthermore, Cr substitution significantly improves the electrochemical performances of LiCo1-1.5xCrxPO4/C (x = 0.02, 0.04, 0.06) cathode. Notably, the LiCo0.94Cr0.04PO4/C delivers an initial discharge capacity of 144 mA h g-1 at 0.1 C and shows a capacity retention of 71% after 100 cycles between 3.0 and 5.0 V. The CV and EIS results indicate that the polarization is reduced and that the electronic and ionic conductivities are improved by Cr substitution. The good electrochemical performances for Cr-substituted LiCoPO4/C electrodes are attributed to the lower antisite defect concentration, as the reduction of polarization, the improvement of electronic and ion conductivity and the uniform carbon layer. These features will accelerate the commercial application of LiCoPO4 towards the start-art of the high voltage lithium-ion batteries.

NASA World Wind, Open Source 4D Geospatial Visualization Platform: *.NET & Java*

Science.gov (United States)

Hogan, P.; Coughlan, J.

2006-12-01

NASA World Wind has only one goal, to provide the maximum opportunity for geospatial information to be experienced, be it education, science, research, business, or government. The benefits to understanding for information delivered in the context of its 4D virtual reality are extraordinary. The NASA World Wind visualization platform is open source and therefore lends itself well to being extended to service *any* requirements, be they proprietary and commercial or simply available. Data accessibility is highly optimized using standard formats including internationally certified open standards (W*S). Although proprietary applications can be built based on World Wind, and proprietary data delivered that leverage World Wind, there is nothing proprietary about the visualization platform itself or the multiple planetary data sets readily available, including global animations of live weather. NASA World Wind is being used by NASA research teams as well as being a formal part of high school and university curriculum. The National Guard uses World Wind for emergency response activities and State governments have incorporated high resolution imagery for GIS management as well as for their cross-agency emergency response activities. The U.S. federal government uses NASA World Wind for a myriad of GIS and security-related issues (NSA, NGA, DOE, FAA, etc.).

Topological identification of the first uninodal 8-connected lsz MOF built from 2,2'-difluorobiphenyl-4,4'-dicarboxylate pillars and cadmium(II)-triazolate layers.

Science.gov (United States)

Zhang, Yuchi; Wu, Yuanhua; He, Xin; Ma, Junhan; Shen, Xuan; Zhu, Dunru

2018-03-01

Using polynuclear metal clusters as nodes, many high-symmetry high-connectivity nets, like 8-connnected bcu and 12-connected fcu, have been attained in metal-organic frameworks (MOFs). However, construction of low-symmetry high-connected MOFs with a novel topology still remains a big challenge. For example, a uninodal 8-connected lsz network, observed in inorganic ZrSiO 4 , has not been topologically identified in MOFs. Using 2,2'-difluorobiphenyl-4,4'-dicarboxylic acid (H 2 L) as a new linker and 1,2,4-triazole (Htrz) as a coligand, a novel three-dimensional Cd II -MOF, namely poly[tetrakis(μ 4 -2,2'-difluorobiphenyl-4,4'-dicarboxylato-κ 5 O 1 ,O 1' :O 1' :O 4 :O 4' )tetrakis(N,N-dimethylformamide-κO)tetrakis(μ 3 -1,2,4-triazolato-κ 3 N 1 :N 2 :N 4 )hexacadmium(II)], [Cd 6 (C 14 H 6 F 2 O 4 ) 4 (C 2 H 2 N 3 ) 4 (C 3 H 7 NO) 4 ] n , (I), has been prepared. Single-crystal structure analysis indicates that six different Cd II ions co-exist in (I) and each Cd II ion displays a distorted [CdO 4 N 2 ] octahedral geometry with four equatorial O atoms and two axial N atoms. Three Cd II ions are connected by four carboxylate groups and four trz - ligands to form a linear trinuclear [Cd 3 (COO) 4 (trz) 4 ] cluster, as do the other three Cd II ions. Two Cd 3 clusters are linked by trz - ligands in a μ 1,2,4 -bridging mode to produce a two-dimensional Cd II -triazolate layer with (6,3) topology in the ab plane. These two-dimensional layers are further pillared by the L 2- ligands along the c axis to generate a complicated three-dimensional framework. Topologically, regarding the Cd 3 cluster as an 8-connected node, the whole architecture of (I) is a uninodal 8-connected lsz framework with the Schläfli symbol (4 22 ·6 6 ). Complex (I) was further characterized by elemental analysis, IR spectroscopy, powder X-ray diffraction, thermogravimetric analysis and a photoluminescence study. MOF (I) has a high thermal and water stability.

Simulation of Natural Convection in the Oxide Layer of Three-Layer Corium Pool in an IVR

Energy Technology Data Exchange (ETDEWEB)

Kim, Su-Hyeon; Park, Hae-Kyun; Chung, Bum-Jin [Kyung Hee University, Yongin (Korea, Republic of)

2016-10-15

This paper describes the three-layer phenomena and preliminary plan to simulate the oxide layer experimentally. We will perform the mass transfer experiments using a copper sulfate-sulfuric acid (CuSO{sub 4}-H{sub 2}SO{sub 4}) electroplating system based on the heat and mass transfer analogy concept. By performing the mass transfer experiments, we can achieve the high buoyancy condition with small facilities. The test facility is semicircular whose bottom is chopped, simulating the oxide pool above the heavy metal layer in a three-layer configuration. We will measure the heat flux at the top plate, side wall and bottom plate, and compare these results with those for a two-layer pool. In a three-layer configuration, the upper light metal layer becomes thinner, increasing the focusing effect. Thus, it is important to evaluate the heat flux from the oxide pool to the upper metallic layer. However, there is few heat transfer studies for a three-layer configuration. This paper is to discuss and to make a plan for the heat transfer experiments of oxide pool in a three- layer system. We will perform the mass transfer experiments based on the heat and mass transfer analogy concept. The test results will be analyzed phenomenologically and compared with two-layer results.

Morphology, microstructure, and hardness of titanium (Ti-6Al-4V) blocks deposited by wire-feed additive layer manufacturing (ALM)

International Nuclear Information System (INIS)

Brandl, Erhard; Schoberth, Achim; Leyens, Christoph

2012-01-01

Highlights: ► The microstructure and hardness of deposited Ti-6Al-4V blocks are investigated. ► Hardness is influenced by post heat treatment rather than by process parameters. ► Microstructure within the prior β-grains varies to some extent from grain to grain. ► A 600 °C/4 h treatment significantly increased the average hardness. - Abstract: Additive layer manufacturing offers a potential for time and cost savings, especially for aerospace components made from costly titanium alloys. In this paper, the morphology, microstructure, chemical composition, and hardness of additive manufactured Ti-6Al-4V blocks are investigated and discussed. Blocks (7 beads wide, 7 layers high) were deposited using Ti-6Al-4V wire and a Nd:YAG laser. Two different sets of parameters are used and three different post heat treatment conditions (as-built, 600 °C/4 h, 1200 °C/2 h) are investigated. The experiments reveal elementary properties of additive manufactured Ti-6Al-4V material in correlation to process parameters and heat treatments, which are discussed comprehensively.

Fabrication and evaluation of auto-stripped tri-layer wound dressing for extensive burn injury

International Nuclear Information System (INIS)

Lin, F.-H.; Tsai, J.-C.; Chen, T.-M.; Chen, K.-S.; Yang, J.-M.; Kang, P.-L.; Wu, T-H.

2007-01-01

In the study, we are going to develop a tri-layer membrane as the artificial skin for extensive burn injury. The first layer is a three-dimensional tri-copolymer sponge of gelatin/hyaluronan/chodroitin-6-sulfate with 70% in porosity and 20-100 μm in pore size. The layer is constructed as a dermis analogous layer to stimulate capillaries penetration, to promote dermal fibroblast migration and to induce the secretion of extra-cellular matrix, which provides a better physiological environment for burn patient recovery. The second layer is as so called auto-stripped layer composed by poly-N-isopropyacrylamide (PNIPAAm). The layer will be automatically peeled off from the tri-copolymer layer once the wound site closed and recovered. The third layer is composed by polypropylene (PP) non-woven fabric, which provides an open structure for exudates drainage out that will reduce the risk of second infection. The tri-layer wound dressing has been successfully prepared by subsequently high-energy plasma treatment, γ-ray irradiation, UV light exposure, and lyophilized process. From the results of MTT, IL-8, IL-1α, IL-6, and TNF-α measurement, the developed material will not induce tissue inflammatory or immune response. The dermal fibroblasts showed initial contact with the material surface through the radial extension of filopodia followed by cytoplasmic webbing that could be examined by SEM. Dermal fibroblasts subsequently flattened for further proliferation and extra-cellular matrix secretion. Dermal analog layer provides a three-dimensional architecture for normal dermis regeneration. The layer can be completely biodegraded within 4 weeks post-operation. After served as a scaffold for the ingrowth of self-fibroblasts, a normal dermis like layer will be regenerated. The dressing will fall off automatically without any damage once the wound site healed completely

N-channel thin-film transistors based on 1,4,5,8-naphthalene tetracarboxylic dianhydride with ultrathin polymer gate buffer layer

International Nuclear Information System (INIS)

Tanida, Shinji; Noda, Kei; Kawabata, Hiroshi; Matsushige, Kazumi

2009-01-01

N-channel operation of thin-film transistors based on 1,4,5,8-naphthalene tetracarboxylic dianhydride (NTCDA) with a 9-nm-thick poly(methyl methacrylate) (PMMA) gate buffer layer was examined. The uniform coverage of the ultrathin PMMA layer on an SiO 2 gate insulator, verified by X-ray reflectivity measurement, caused the increase of electron field-effect mobility because of the suppression of electron traps existing on the SiO 2 surface. In addition, air stability for n-channel operation of the NTCDA transistor was also improved by the PMMA layer which possibly prevented the adsorption of ambient water molecules onto the SiO 2 surface.

Sliding charge density wave in the monophosphate tungsten bronze (PO2)4(WO3)2m with alternate stacking of m=4 and m=6 WO3 layers

International Nuclear Information System (INIS)

Foury-Leylekian, P.; Sandre, E.; Ravy, S.; Pouget, J.-P.; Elkaim, E.; Roussel, P.; Groult, D.; Labbe, Ph.

2002-01-01

The monophosphate tungsten bronzes (PO 2 ) 4 (WO 3 ) 2m form family of two-dimensional metals which exhibit charge density wave (CDW) instabilities. These materials are generally built by the regular stacking of (a,b) layers in which chains made of segments of m WO 6 octahedra directed along the a and a±b directions are delimited. Their electronic structure thus originates from quasi-one-dimensional (1D) bands located on these chains. As a consequence their Fermi surface (FS) exhibits large flat portions whose nesting gives rise to successive CDW instabilities. Here we present a structural study of the CDW instability of the (PO 2 ) 4 (WO 3 ) 10 member formed by the alternate stacking of layers built with segments of m=4 and m=6 WO 6 octahedra. Its ab initio electronic structure calculation shows that the FS of this member exhibits large flat portions which can be extremely well nested. Its best nesting wave vector accounts for the modulation wave vector stabilized by the CDW transition which occurs at 156 K. Because of the regular stacking of layers of different m values the FS is slightly split. The unusual thermal dependence of the x-ray satellite intensity provides evidence that the two types of layers become modulated at different temperature. This also leads to a slight thermal sliding of the CDW-nesting modulation wave vector, which can be accounted for within the framework of a Landau-Ginzburg theory. In addition, the observation of a global hysteresis in the thermal cycling of the satellite intensity, as well as the degradation of the interlayer order upon cooling, suggest the formation of a disordered lattice of dilute solitons. Such solitons allow to accommodate the charge transferred between the two types of layer. Finally the relevance of local charge transfers, at intergrowth defects, for example, to create pinned discommensurations that break the CDW coherence is emphasized in this whole family of bronzes

Study of A-site doping of SrBi4Ti4O15 Bi-layered compounds using micro-Raman spectroscopy

International Nuclear Information System (INIS)

Hao, H.; Liu, H.X.; Cao, M.H.; Min, X.M.; Ouyang, S.X.

2006-01-01

The temperature-dependent Raman spectra of Mg- and La-doped SrBi 4 Ti 4 O 15 (SBT) were studied in the range 40-590 C. A quantum chemistry calculation was employed to estimate these two substitution states. It was found that A-site doping in this study not only caused multiplicative substitution states, but also the Raman spectra changed with the substitution amount. In a La-doped perovskite-like layer, La would occupy the Bi site when x>0.10 and the 314 and 550 cm -1 modes related to the rotating and tilting of the TiO 6 octahedron firstly became wide and then became sharp. With the increase of the substitution amount, both substitution states of Mg-doped SBT lead to the widening of 270 and 520 cm -1 peaks. (orig.)

Study of A-site doping of SrBi4Ti4O15 Bi-layered compounds using micro-Raman spectroscopy

Science.gov (United States)

Hao, H.; Liu, H. X.; Cao, M. H.; Min, X. M.; Ouyang, S. X.

2006-10-01

The temperature-dependent Raman spectra of Mg- and La-doped SrBi4Ti4O15 (SBT) were studied in the range 40 590 °C. A quantum chemistry calculation was employed to estimate these two substitution states. It was found that A-site doping in this study not only caused multiplicative substitution states, but also the Raman spectra changed with the substitution amount. In a La-doped perovskite-like layer, La would occupy the Bi site when x>0.10 and the 314 and 550 cm-1 modes related to the rotating and tilting of the TiO6 octahedron firstly became wide and then became sharp. With the increase of the substitution amount, both substitution states of Mg-doped SBT lead to the widening of 270 and 520 cm-1 peaks.

Topotactic condensation of layer silicates with ferrierite-type layers forming porous tectosilicates.

Science.gov (United States)

Marler, B; Wang, Y; Song, J; Gies, H

2014-07-21

Five different hydrous layer silicates (HLSs) containing fer layers (ferrierite-type layers) were obtained by hydrothermal syntheses from mixtures of silicic acid, water and tetraalkylammonium/tetraalkylphosphonium hydroxides. The organic cations had been added as structure directing agents (SDA). A characteristic feature of the structures is the presence of strong to medium strong hydrogen bonds between the terminal silanol/siloxy groups of neighbouring layers. The five-layered silicates differ chemically only with respect to the organic cations. Structurally, they differ with respect to the arrangement of the fer layers relative to each other, which is distinct for every SDA-fer-layer system. RUB-20 (containing tetramethylammonium) and RUB-40 (tetramethylphosphonium) are monoclinic with stacking sequence AAA and shift vectors between successive layers 1a0 + 0b0 + 0.19c0 and 1a0 + 0b0 + 0.24c0, respectively. RUB-36 (diethyldimethylammonium), RUB-38 (methyltriethylammonium) and RUB-48 (trimethylisopropylammonium) are orthorhombic with stacking sequence ABAB and shift vectors 0.5a0 + 0b0± 0.36c0, 0.5a0 + 0b0 + 0.5c0 and 0.5a0 + 0b0± 0.39c0, respectively. Unprecedented among the HLSs, two monoclinic materials are made up of fer layers which possess a significant amount of ordered defects within the layer. The ordered defects involve one particular Si-O-Si bridge which is, to a fraction of ca. 50%, hydrolyzed to form nests of two ≡Si-OH groups. When heated to 500-600 °C in air, the HLSs condense to form framework silicates. Although all layered precursors were moderately to well ordered, the resulting framework structures were of quite different crystallinity. The orthorhombic materials RUB-36, -38 and -48, general formula SDA4Si36O72(OH)4, which possess very strong hydrogen bonds (d[O···O] ≈ 2.4 Å), transform into a fairly or well ordered CDO-type silica zeolite RUB-37. The monoclinic materials RUB-20 and -40, general formula SDA2Si18O36(OH)2OH, possessing

SEM and XPS study of layer-by-layer deposited polypyrrole thin films

International Nuclear Information System (INIS)

Pigois-Landureau, E.; Nicolau, Y.F.; Delamar, M.

1996-01-01

Layer-by-layer deposition of thin films (a few nm) of polypyrrole was carried out on various substrates such as silver, platinum, electrochemically oxidized aluminum and pretreated glass. SEM micrographs showed that the deposited layers nucleate by an island-type mechanism on hydrated alumina and KOH-pretreated (hydrophilic) glass before forming a continuous film. However, continuous thin films are obtained on chromic acid pretreated (hydrophobic) glass and sputtered Ag or Pt on glass after only 3 endash 4 deposition cycles. The mean deposition rate evaluated by XPS for the first deposition cycles on Ag and Pt is 3 and 4 nm/cycle, respectively, in agreement with previous gravimetric determinations on thicker films, proving the constancy of the deposition rate. The XPS study of the very thin films obtained by a few deposition cycles shows that the first polypyrrole layers are dedoped by hydroxydic (basic) substrate surfaces. copyright 1996 American Institute of Physics

Tandem organic light-emitting diodes with KBH4 doped 9,10-bis(3-(pyridin-3-yl)phenyl) anthracene connected to the charge generation layer.

Science.gov (United States)

Duan, Lian; Tsuboi, Taiju; Qiu, Yong; Li, Yanrui; Zhang, Guohui

2012-06-18

Tandem organic light emitting diodes (OLEDs) are ideal for lighting applications due to their low working current density at high brightness. In this work, we have studied an efficient electron transporting layer of KBH(4) doped 9,10-bis(3-(pyridin-3-yl)phenyl)anthracene (DPyPA) which is located adjacent to charge generation layer of MoO(3)/NPB. The excellent transporting property of the DPyPA:KBH(4) layer helps the tandem OLED to achieve a lower voltage than the tandem device with the widely used tris-(8-hydroxyquinoline)aluminum:Li. For the tandem white OLED with a fluorescent blue unit and a phosphorescent yellow unit, we've achieved a high current efficiency of 75 cd/A, which can be further improved to 120 cd/A by attaching a diffuser layer.

High reliable and stable organic field-effect transistor nonvolatile memory with a poly(4-vinyl phenol) charge trapping layer based on a pn-heterojunction active layer

Energy Technology Data Exchange (ETDEWEB)

Xiang, Lanyi; Ying, Jun; Han, Jinhua; Zhang, Letian, E-mail: zlt@jlu.edu.cn, E-mail: wwei99@jlu.edu.cn; Wang, Wei, E-mail: zlt@jlu.edu.cn, E-mail: wwei99@jlu.edu.cn [State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun 130012 (China)

2016-04-25

In this letter, we demonstrate a high reliable and stable organic field-effect transistor (OFET) based nonvolatile memory (NVM) with a polymer poly(4-vinyl phenol) (PVP) as the charge trapping layer. In the unipolar OFETs, the inreversible shifts of the turn-on voltage (V{sub on}) and severe degradation of the memory window (ΔV{sub on}) at programming (P) and erasing (E) voltages, respectively, block their application in NVMs. The obstacle is overcome by using a pn-heterojunction as the active layer in the OFET memory, which supplied a holes and electrons accumulating channel at the supplied P and E voltages, respectively. Both holes and electrons transferring from the channels to PVP layer and overwriting the trapped charges with an opposite polarity result in the reliable bidirectional shifts of V{sub on} at P and E voltages, respectively. The heterojunction OFET exhibits excellent nonvolatile memory characteristics, with a large ΔV{sub on} of 8.5 V, desired reading (R) voltage at 0 V, reliable P/R/E/R dynamic endurance over 100 cycles and a long retention time over 10 years.

Synthesis of PbI(2) single-layered inorganic nanotubes encapsulated within carbon nanotubes.

Science.gov (United States)

Cabana, Laura; Ballesteros, Belén; Batista, Eudar; Magén, César; Arenal, Raúl; Oró-Solé, Judith; Rurali, Riccardo; Tobias, Gerard

2014-04-02

The template assisted growth of single-layered inorganic nanotubes is reported. Single-crystalline lead iodide single-layered nanotubes have been prepared using the inner cavities of carbon nanotubes as hosting templates. The diameter of the resulting inorganic nanotubes is merely dependent on the diameter of the host. This facile method is highly versatile opening up new horizons in the preparation of single-layered nanostructures. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Low-temperature liquid-phase epitaxy and optical waveguiding of rare-earth-ion-doped KY(WO4)2 thin layers

NARCIS (Netherlands)

Romanyuk, Y.E.; Utke, I.; Ehrentraut, D.; Apostolopoulos, V.; Pollnau, Markus; Garcia-Revilla, S.; Valiente, B.

2004-01-01

Crystalline $KY(WO_{4})_{2}$ thin layers doped with different rare-earth ions were grown on b-oriented, undoped $KY(WO_{4})_{2}$ substrates by liquid-phase epitaxy employing a low-temperature flux. The ternary chloride mixture of NaCl, KCl, and CsCl with a melting point of 480°C was used as a

Synthesis and characterization of Mg-Al-layered double hydroxides intercalated with cubane-1,4-dicarboxylate anions.

Science.gov (United States)

Rezvani, Zolfaghar; Arjomandi Rad, Farzad; Khodam, Fatemeh

2015-01-21

In the present work, Mg2Al-layered double hydroxide (LDH) intercalated with cubane-1,4-dicarboxylate anions was prepared from the reaction of solutions of Mg(ii) and Al(iii) nitrate salts with an alkaline solution of cubane-1,4-dicarboxylic acid by using the coprecipitation method. The successful preparation of a nanohybrid of cubane-1,4-dicarboxylate(cubane-dc) anions with LDH was confirmed by powder X-ray diffraction, FTIR spectroscopy and thermal gravimetric analysis (TGA). The increase in the basal spacing of LDHs from 8.67 Å to 13.40 Å shows that cubane-dc anions were successfully incorporated into the interlayer space. Thermogravimetric analyses confirm that the thermal stability of the intercalated cubane-dc anions is greater than that of the pure form before intercalation because of host-guest interactions involving hydrogen bonds. The interlayer structure, hydrogen bonding, and subsequent distension of LDH compounds containing cubane-dc anions were shown by molecular simulation. The RDF (radial distribution function), mean square displacement (MSD), and self-diffusion coefficient were calculated using the trajectory files on the basis of molecular dynamics (MD) simulations, and the results indicated that the cubane-dc anions were more stable when intercalated into the LDH layers. A good agreement was obtained between calculated and measured X-ray diffraction patterns and between experimental and calculated basal spacings.

Summer Restaurant opening times

CERN Document Server

2015-01-01

Restaurant No. 1: Open as usual in July and August. Open from 7 a.m. to 10 p.m. on Thursday, 10 September (Jeûne genevois).   Restaurant No. 2: Open as usual in July and August. Closed on Thursday, 10 September (Jeûne genevois) and Friday, 11 September. The Brasserie (table service) will be closed from Monday, 4 August to Friday, 11 September.   Restaurant No. 3: Open as usual in July and August, but closed on Saturday, 1 August; Saturday, 15 August; Thursday, 10 September (Jeûne genevois); and Friday, 11 September.   Snack bar in Building 54: Closed from Monday, 4 August to Friday, 11 September.   Snack bars in Buildings 13, 30 and 6: Closed on Thursday, 10 September (Jeûne genevois) and Friday, 11 September.

Analytical modelling of a thin liquid metal layer submitted to an ac magnetic field

Energy Technology Data Exchange (ETDEWEB)

Hinaje, M [Groupe de Recherche en Electrotechnique et Electronique de Nancy, 2 avenue de la Foret de Haye, 54516 Vandoeuvre-les-Nancy (France); Vinsard, G [Laboratoire d' Energetique et de Mecanique Theorique et Appliquee, 2 avenue de la Foret de Haye, 54516 Vandoeuvre-les-Nancy (France); Dufour, S [Laboratoire d' Energetique et de Mecanique Theorique et Appliquee, 2 avenue de la Foret de Haye, 54516 Vandoeuvre-les-Nancy (France)

2006-07-07

A cylindrical thin liquid metal layer is submitted to a uniform ac magnetic field. When the intensity of the electromagnetic field exceeds a critical value, an opening in the liquid is shaped from outside to inside. At a given intensity of the electromagnetic field, this opening is in a frozen state, that is, the liquid metal layer reaches a new equilibrium shape. In this paper, we show that this equilibrium corresponds to a minimum of the total energy of the system. This total energy is equal to the sum of the magnetic energy and the mechanical energy. The magnetic energy is computed by assuming that the induced eddy current flowing through the liquid metal layer is concentrated in the cross-section S{sub c} equal to the product of the skin depth and the thickness of the layer. This assumption leads us to study an equivalent electrical circuit. The mechanical energy is composed of the potential energy and the surface energy.

Analytical modelling of a thin liquid metal layer submitted to an ac magnetic field

International Nuclear Information System (INIS)

Hinaje, M; Vinsard, G; Dufour, S

2006-01-01

A cylindrical thin liquid metal layer is submitted to a uniform ac magnetic field. When the intensity of the electromagnetic field exceeds a critical value, an opening in the liquid is shaped from outside to inside. At a given intensity of the electromagnetic field, this opening is in a frozen state, that is, the liquid metal layer reaches a new equilibrium shape. In this paper, we show that this equilibrium corresponds to a minimum of the total energy of the system. This total energy is equal to the sum of the magnetic energy and the mechanical energy. The magnetic energy is computed by assuming that the induced eddy current flowing through the liquid metal layer is concentrated in the cross-section S c equal to the product of the skin depth and the thickness of the layer. This assumption leads us to study an equivalent electrical circuit. The mechanical energy is composed of the potential energy and the surface energy

Wetting behaviour of lead-free Sn-based alloys on Cu and Ni substrates

International Nuclear Information System (INIS)

Amore, S.; Ricci, E.; Borzone, G.; Novakovic, R.

2008-01-01

The present work was carried out in the framework of the study of new lead-free solder alloys for technical applications in electronic devices. In the focus of this characterisation the wetting behaviour of several Sn-rich alloys belonging to the In-Sn, Au-Sn and Cu-Sn systems has been studied by measuring the contact angle variations on Cu and Ni substrates as a function of time and temperature. The interface between the alloy and the substrate has been analysed by the use of optical microscopy and scanning electron microscopy combined with energy-dispersive X-ray spectrometry in order to study the reaction between the alloy and the solid substrate and the possible formation of different compounds at the interface. A remarkable effect of the two different substrates on the behaviour of the contact angle as a function of temperature and on the morphology of the interface between the liquid solder and the solid substrate was observed for the In-Sn and Cu-Sn, while the Au-Sn system shows a very similar wetting behaviour on Cu and Ni

Correlation between central corneal thickness and visual field defects, cup to disc ratio and retinal nerve fiber layer thickness in primary open angle glaucoma patients.

Science.gov (United States)

Sarfraz, Muhammad Haroon; Mehboob, Mohammad Asim; Haq, Rana Intisar Ul

2017-01-01

To evaluate the correlation between Central Corneal Thickness (CCT) and Visual Field (VF) defect parameters like Mean Deviation (MD) and Pattern Standard Deviation (PSD), Cup-to-Disc Ratio (CDR) and Retinal Nerve Fibre Layer Thickness (RNFL-T) in Primary Open-Angle Glaucoma (POAG) patients. This cross sectional study was conducted at Armed Forces Institute of Ophthalmology (AFIO), Rawalpindi from September 2015 to September 2016. Sixty eyes of 30 patients with diagnosed POAG were analysed. Correlation of CCT with other variables was studied. Mean age of study population was 43.13±7.54 years. Out of 30 patients, 19 (63.33%) were males and 11 (36.67%) were females. Mean CCT, MD, PSD, CDR and RNFL-T of study population was 528.57±25.47µm, -9.11±3.07, 6.93±2.73, 0.63±0.13 and 77.79±10.44µm respectively. There was significant correlation of CCT with MD, PSD and CDR (r=-0.52, pfield parameters like mean deviation and pattern standard deviation, as well as with cup-to-disc ratio. However, central corneal thickness had no significant relationship with retinal nerve fibre layer thickness.

Turbulent boundary layer under the control of different schemes.

Science.gov (United States)

Qiao, Z X; Zhou, Y; Wu, Z

2017-06-01

This work explores experimentally the control of a turbulent boundary layer over a flat plate based on wall perturbation generated by piezo-ceramic actuators. Different schemes are investigated, including the feed-forward, the feedback, and the combined feed-forward and feedback strategies, with a view to suppressing the near-wall high-speed events and hence reducing skin friction drag. While the strategies may achieve a local maximum drag reduction slightly less than their counterpart of the open-loop control, the corresponding duty cycles are substantially reduced when compared with that of the open-loop control. The results suggest a good potential to cut down the input energy under these control strategies. The fluctuating velocity, spectra, Taylor microscale and mean energy dissipation are measured across the boundary layer with and without control and, based on the measurements, the flow mechanism behind the control is proposed.

Layered distributed architecture for plant automation

International Nuclear Information System (INIS)

Aravamuthan, G.; Verma, Yachika; Ranjan, Jyoti; Chachondia, Alka S.; Ganesh, G.

2005-01-01

The development of plant automation system and associated software remains one of the greatest challenges to the widespread implementation of highly adaptive re-configurable automation technology. This paper presents a layered distributed architecture for a plant automation system designed to support rapid reconfiguration and redeployment of automation components. The paper first presents evolution of automation architecture and their associated environment in the past few decades and then presents the concept of layered system architecture and the use of automation components to support the construction of a wide variety of automation system. It also highlights the role of standards and technology, which can be used in the development of automation components. We have attempted to adhere to open standards and technology for the development of automation component at a various layers. It also highlights the application of this concept in the development of an Operator Information System (OIS) for Advanced Heavy Water Reactor (AHWR). (author)

Tuning plasmons layer-by-layer for quantitative colloidal sensing with surface-enhanced Raman spectroscopy.

Science.gov (United States)

Anderson, William J; Nowinska, Kamila; Hutter, Tanya; Mahajan, Sumeet; Fischlechner, Martin

2018-04-19

Surface-enhanced Raman spectroscopy (SERS) is well known for its high sensitivity that emerges due to the plasmonic enhancement of electric fields typically on gold and silver nanostructures. However, difficulties associated with the preparation of nanostructured substrates with uniform and reproducible features limit reliability and quantitation using SERS measurements. In this work we use layer-by-layer (LbL) self-assembly to incorporate multiple functional building blocks of collaborative assemblies of nanoparticles on colloidal spheres to fabricate SERS sensors. Gold nanoparticles (AuNPs) are packaged in discrete layers, effectively 'freezing nano-gaps', on spherical colloidal cores to achieve multifunctionality and reproducible sensing. Coupling between layers tunes the plasmon resonance for optimum SERS signal generation to achieve a 10 nM limit of detection. Significantly, using the layer-by-layer construction, SERS-active AuNP layers are spaced out and thus optically isolated. This uniquely allows the creation of an internal standard within each colloidal sensor to enable highly reproducible self-calibrated sensing. By using 4-mercaptobenzoic acid (4-MBA) as the internal standard adenine concentrations are quantified to an accuracy of 92.6-99.5%. Our versatile approach paves the way for rationally designed yet quantitative colloidal SERS sensors and their use in a variety of sensing applications.

Through the Open Door--Today's Revolution in Open Access and Distance Learning.

Science.gov (United States)

Bennett, Roger, Ed.

1986-01-01

Consists of eight articles discussing the topic of open learning. Articles address (1) definitions, (2) corporate training, (3) further education programs, (4) university-based training, (5) distance learning, (6) learning to learn, (7) Britain's Open University, (8) the Business-Technical Education Council. (CH)

Effects of CdS Buffer Layers on Photoluminescence Properties of Cu2ZnSnS4 Solar Cells

Directory of Open Access Journals (Sweden)

A. Le Donne

2015-01-01

Full Text Available Cu2ZnSnS4 (CZTS absorber layers grown by sputtering were investigated by photoluminescence before and after the chemical bath deposition of CdS in order to evaluate the possible passivation of point defects by Cd atoms at the absorber/buffer layer interface. According to the literature, a broad emission around 1.21 eV was observed at low temperature under above bandgap excitation of the as-grown CZTS samples. Broad bands at 1.075 eV and 0.85 eV were detected for the first time under below bandgap excitation of the as-grown CZTS samples at low temperature, which were explained in terms of radiative transitions involving point defect-related levels determined in the literature by first-principles calculations. The emissions observed in the as-grown samples were monitored by both above and below bandgap excitations also in standard CZTS solar cells produced on the same layers. The obtained results suggest that, as in the case of Cu(In, GaSe2, Cd atoms passivate point defects at the absorber/buffer layer interface also in CZTS.

Effects of silicon:carbon P+ layer interfaces on solar cells

International Nuclear Information System (INIS)

Jeffrey, F.R.; Vernstrom, G.D.; Weber, M.F.; Gilbert, J.R.

1987-01-01

Results are presented showing the effects on amorphous silicon (a-Si) photovoltaic performance of the interfaces associated with a silicon carbide (a-Si:C) p+ layer. Carbon grading into the intrinsic layer from the p+ layer increases open circuit voltage (Voc) from 0.7V to 0.88V. This effect is very similar to the boron profile effect reported earlier and supports the contention that Voc is being limited by an electron current at the p-i interface. The interface between the p+ a-Si:C layer and the transparent conductive oxide (TCO) is shown to be a potential source of high series resistance, with an abrupt interface showing the most serious problem. The effect is explained by electron injection from the TCO into the p+ layer being inhibited as a result of band mismatch

Wind Energy-Related Atmospheric Boundary Layer Large-Eddy Simulation Using OpenFOAM: Preprint

Energy Technology Data Exchange (ETDEWEB)

Churchfield, M.J.; Vijayakumar, G.; Brasseur, J.G.; Moriarty, P.J.

2010-08-01

This paper develops and evaluates the performance of a large-eddy simulation (LES) solver in computing the atmospheric boundary layer (ABL) over flat terrain under a variety of stability conditions, ranging from shear driven (neutral stratification) to moderately convective (unstable stratification).

Fluid Annotations in a Open World

DEFF Research Database (Denmark)

Zellweger, Polle Trescott; Bouvin, Niels Olof; Jehøj, Henning

2001-01-01

Fluid Documents use animated typographical changes to provide a novel and appealing user experience for hypertext browsing and for viewing document annotations in context. This paper describes an effort to broaden the utility of Fluid Documents by using the open hypermedia Arakne Environment to l...... to layer fluid annotations and links on top of abitrary HTML pages on the World Wide Web. Changes to both Fluid Documents and Arakne are required....

Electronic, magnetic and optical properties of reduced hybrid layered complex Ni(pyz)V{sub 4}O{sub 10} (pyz=C{sub 4}H{sub 4}N{sub 2}) by first-principles

Energy Technology Data Exchange (ETDEWEB)

Munir, Junaid; Mat Isa, Ahmad Radzi [Physics Department, Faculty of Science, Universiti Teknologi Malaysia, Skudai 81310, Johor (Malaysia); Yousaf, Masood [IBS Center for Multidimensional Carbon Materials, Ulsan National Institute of Science and Technology, Ulsan 689-798 (Korea, Republic of); Aliabad, H.A. Rahnamaye [Department of Physics, Hakim Sabzevari University (Iran, Islamic Republic of); Ain, Qurat-ul [Key Laboratory for Laser Plasamas (MOE) & Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Saeed, M.A., E-mail: saeed@utm.my [Physics Department, Faculty of Science, Universiti Teknologi Malaysia, Skudai 81310, Johor (Malaysia)

2016-10-15

This article reports the electronic, structure, magnetic and optical properties of reduced hybrid layered complex Ni(pyz)V{sub 4}O{sub 10} (pyz=C{sub 4}H{sub 4}N{sub 2}) studied by employing density functional theory with local density approximation (LDA), generalized gradient approximation (GGA) of Perdew–Burke–Ernzerhof-96 (PBE) and modified Becke–Johnson (mBJ) exchange-correlation potential and energy. The band structure and density of states of these compounds are also presented. The total density of states (DOS) for up and down spin states clearly split, which means that the exchange interaction causes the ordered spin arrangement. PBE-mBJ calculation reveals a wider band gap in spin down state, which shows a half-metallic electronic character at the equilibrium state. The spin-polarized calculations indicate metallic nature in orthorhombic crystalline phase. It is also noted that the optical conductivity for PBE-mBJ is larger than that of LDA and PBE-GGA. Furthermore, the results show a half-metallic ferromagnetic ground state for Ni(pyz)V{sub 4}O{sub 10} in PBE-mBJ potential. The present results suggest Ni(pyz)V{sub 4}O{sub 10} compound as a potential candidate for the future optoelectronic and spintronic applications. - Highlights: • First study of the electronic, structure, magnetic and optical properties of reduced hybrid layered complex Ni(pyz)V{sub 4}O{sub 10} (pyz=C{sub 4}H{sub 4}N{sub 2}) by first principles. • PBE-mBJ calculation reveals a wider band gap in spin down state indicating its half-metallic electronic character. • The large spin magnetic moment on Ni and V cations indicates the ferromagnetic interaction which makes this compound suitable candidate for spintronics applications. • An optical band gap reveals that this compound is also useful for the application in optoelectronics.

Observation of hole injection boost via two parallel paths in Pentacene thin-film transistors by employing Pentacene: 4, 4″-tris(3-methylphenylphenylamino triphenylamine: MoO3 buffer layer

Directory of Open Access Journals (Sweden)

Pingrui Yan

2014-11-01

Full Text Available Pentacene organic thin-film transistors (OTFTs were prepared by introducing 4, 4″-tris(3-methylphenylphenylamino triphenylamine (m-MTDATA: MoO3, Pentacene: MoO3, and Pentacene: m-MTDATA: MoO3 as buffer layers. These OTFTs all showed significant performance improvement comparing to the reference device. Significantly, we observe that the device employing Pentacene: m-MTDATA: MoO3 buffer layer can both take advantage of charge transfer complexes formed in the m-MTDATA: MoO3 device and suitable energy level alignment existed in the Pentacene: MoO3 device. These two parallel paths led to a high mobility, low threshold voltage, and contact resistance of 0.72 cm2/V s, −13.4 V, and 0.83 kΩ at Vds = − 100 V. This work enriches the understanding of MoO3 doped organic materials for applications in OTFTs.

The effect of Cr buffer layer thickness on voltage generation of thin-film thermoelectric modules

International Nuclear Information System (INIS)

Mizoshiri, Mizue; Mikami, Masashi; Ozaki, Kimihiro

2013-01-01

The effect of Cr buffer layer thickness on the open-circuit voltage generated by thin-film thermoelectric modules of Bi 0.5 Sb 1.5 Te 3 (p-type) and Bi 2 Te 2.7 Se 0.3 (n-type) materials was investigated. A Cr buffer layer, whose thickness generally needs to be optimized to improve adhesion depending on the substrate surface condition, such as roughness, was deposited between thermoelectric thin films and glass substrates. When the Cr buffer layer was 1 nm thick, the Seebeck coefficients and electrical conductivity of 1 µm thermoelectric thin films with the buffer layers were approximately equal to those of the thermoelectric films without the buffer layers. When the thickness of the Cr buffer layer was 1 µm, the same as the thermoelectric films, the Seebeck coefficients of the bilayer films were reduced by an electrical current flowing inside the Cr buffer layer and the generation of Cr 2 Te 3 . The open-circuit voltage of the thin-film thermoelectric modules decreased with an increase in the thickness of the Cr buffer layer, which was primarily induced by the electrical current flow. The reduction caused by the Cr 2 Te 3 generation was less than 10% of the total voltage generation of the modules without the Cr buffer layers. The voltage generation of thin-film thermoelectric modules could be controlled by the Cr buffer layer thickness. (paper)

Morphology, microstructure, and hardness of titanium (Ti-6Al-4V) blocks deposited by wire-feed additive layer manufacturing (ALM)

Energy Technology Data Exchange (ETDEWEB)

Brandl, Erhard, E-mail: erhard.brandl@eads.net [EADS Innovation Works, Metallic Technologies and Surface Engineering, D-81663 Munich (Germany); Schoberth, Achim, E-mail: achim.schoberth@eads.net [EADS Innovation Works, Metallic Technologies and Surface Engineering, D-81663 Munich (Germany); Leyens, Christoph, E-mail: christoph.leyens@tu-dresden.de [Technical University of Dresden, Institute of Materials Science, Chair of Materials Technology, Berndt-Bau, Helmholtzstr. 7, D-01062 Dresden (Germany)

2012-01-15

Highlights: Black-Right-Pointing-Pointer The microstructure and hardness of deposited Ti-6Al-4V blocks are investigated. Black-Right-Pointing-Pointer Hardness is influenced by post heat treatment rather than by process parameters. Black-Right-Pointing-Pointer Microstructure within the prior {beta}-grains varies to some extent from grain to grain. Black-Right-Pointing-Pointer A 600 Degree-Sign C/4 h treatment significantly increased the average hardness. - Abstract: Additive layer manufacturing offers a potential for time and cost savings, especially for aerospace components made from costly titanium alloys. In this paper, the morphology, microstructure, chemical composition, and hardness of additive manufactured Ti-6Al-4V blocks are investigated and discussed. Blocks (7 beads wide, 7 layers high) were deposited using Ti-6Al-4V wire and a Nd:YAG laser. Two different sets of parameters are used and three different post heat treatment conditions (as-built, 600 Degree-Sign C/4 h, 1200 Degree-Sign C/2 h) are investigated. The experiments reveal elementary properties of additive manufactured Ti-6Al-4V material in correlation to process parameters and heat treatments, which are discussed comprehensively.

On the structural phase transitions of the perovskite-type layer structures (Csub(n)Hsub(2n+1)NH3)2MeCl4

International Nuclear Information System (INIS)

Heger, G.

1978-01-01

The perovskite-type layer compounds (Csub(n)Hsub(2n+1)NH 3 ) 2 MeCl 4 show a variety of different structural modifications. They differ from oneanother by the order and dynamical behaviour of the CH 3 -CH 2 -...-CH 2 -NH 3 chain molecules and the [MeCl 6 ] octahedra layers. These two structural members are coupled together by N-H...Cl hydrogen bonds. According to group theoretical relations the modifications of (Csub(n)Hsub(2n+1)NH 3 ) 2 MeCl 4 were ordered in the scheme of a 'family tree'. Taking (CH 3 NH 3 ) 2 MnCl 4 as an example, various experimental investigations incorporated neutron diffraction are reported. They lead to a sequence of phase transitions. For these phase transitions a model is developed based on the orientations of the CH 3 NH 3 dump-bell molecules and their interactions with the [MnCl 6 ] layers. (orig./HPOE) [de

Physical layer impairments tolerance based lightpath provision in software defined optical network

Institute of Scientific and Technical Information of China (English)

Zhao Xianlong; Xu Xianze; Bai Huifeng

2017-01-01

As all-optical networks grow with ever increasing ultra-high speed, the communication quality suffers seriously from physical layer impairments ( PLIs) .The same problem still exists in software defined optical network ( SDON) controlled by OpenFlow.Aimed to solve this problem, a PLIs tol-erance based lightpath provision scheme is proposed for OpenFlow controlled optical networks.This proposed approach not only takes the OSNR model to represent those linear PLIs factors, but also in-troduces those nonlinear factors into the OSNR model.Thus, the proposed scheme is able to cover most PLIs factors of each optical link and conduct optical lightpath provison with better communica-tion quality.Moreover, PLIs tolerance model is also set up and considered in this work with some necessary extension to OpenFlow protocols to achieve better compatibility between physical layer im-pairments factors and various services connections.Simulation results show that the proposed scheme is able to get better performance in terms of packet loss rate and connection setup time.

uFLIP-OC: Understanding Flash I/O Patterns on Open-Channel Solid State Drives

DEFF Research Database (Denmark)

Picoli, Ivan Luiz; Villegas Pasco, Carla Ysabela; Jónsson, Björn Thór

2017-01-01

on a clean break from the block device abstraction. Open-channel SSDs embed a minimal flash translation layer (FTL) and expose their internals to the host. The Linux open-channel SSD subsystem, LightNVM, lets kernel modules as well as user-space applications control data placement and I/O scheduling...