Probing surface plasmons in individual Ag nanoparticles in the ultra-violet spectral regime

International Nuclear Information System (INIS)

Chu, M-W; Chang, C-P; Liou, S C; Wang, J-K; Chen, C H; Sharma, Pradeep; Tsai, K-T; Wang, Y-L

2009-01-01

Previous investigations of surface plasmons in Ag largely focused on their excitations in the visible spectral regime. Using scanning transmission electron microscopy with an electron beam of 0.2 nm in conjunction with electron energy-loss spectroscopy, we spectrally and spatially probe the surface plasmons in individual Ag nanoparticles (∼30 nm), grown on Si, in the ultra-violet spectral regime. The nanomaterials show respective sharp and broad surface-plasmon resonances at ∼3.5 eV (∼355 nm) and ∼7.0 eV (∼177 nm), and the correlated spectral calculations established their multipolar characteristics. The near-field distributions of the surface plasmons on the nanoparticles were also mapped out, revealing the predominant dipolar nature of the 3.5 eV excitation with obvious near-field enhancements at one end of the nano-object. The unveiled near-field enhancements have potential applications in plasmonics and molecular sensing.

Flow and heat transfer regimes during quenching of hot surfaces

International Nuclear Information System (INIS)

Barnea, Y.; Elias, E.

1993-05-01

Reflooding experiments have been performed to study flow and heat transfer regimes in a heated annular vertical channel under supercooled inlet conditions. A gamma densitometer was employed to determine the void fraction as a function of the distance from the quench front. Surface heat fluxes were determined by fast measurements of the temperature spatial distribution. Two quench front is shown to lie in the transition boiling region which spreads into the dry and wet segments of the heated surface. (authors) 5 refs, 3 figs

Efficacy of a rubber outsole with a hybrid surface pattern for preventing slips on icy surfaces.

Science.gov (United States)

Yamaguchi, Takeshi; Hsu, Jennifer; Li, Yue; Maki, Brian E

2015-11-01

Conventional winter-safety footwear devices, such as crampons, can be effective in preventing slips on icy surfaces but the protruding studs can lead to other problems such as trips. A new hybrid (rough and smooth) rubber outsole was designed to provide high slip resistance without use of protruding studs or asperities. In the present study, we examined the slip resistance of the hybrid rubber outsole on both dry (-10 °C) and wet (0 °C) icy surfaces, in comparison to three conventional strap-on winter anti-slip devices: 1) metal coils ("Yaktrax Walker"), 2) gritted (sandpaper-like) straps ("Rough Grip"), and 3) crampons ("Altagrips-Lite"). Drag tests were performed to measure static (SCOF) and dynamic (DCOF) coefficients of friction, and gait trials were conducted on both level and sloped ice surfaces (16 participants). The drag-test results showed relatively high SCOF (≧0.37) and DCOF (≧0.31) values for the hybrid rubber sole, at both temperatures. The other three footwear types exhibited lower DCOF values (0.06-0.20) when compared with the hybrid rubber sole at 0 °C (p footwear types, when descending a slope at -10 °C (6% of trials vs 0%; p footwear-related differences in slip frequency, distance or velocity. These results indicate that the slip-resistance of the hybrid rubber sole on icy surfaces was comparable to conventional anti-slip footwear devices. Given the likely advantages of the hybrid rubber sole (less susceptibility to tripping, better slip resistance on non-icy surfaces), this type of sole should contribute to a decrease in fall accidents; however, further research is needed to confirm its effectiveness under a wider range of test conditions. Copyright © 2015 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Surface-enhanced Raman effect in hybrid metal–semiconductor nanoparticle assemblies

International Nuclear Information System (INIS)

Lughi, Vanni; Bonifacio, Alois; Barbone, Matteo; Marsich, Lucia; Sergo, Valter

2013-01-01

Hybrid metal–semiconductor nanoparticles consisting of silver nanoparticle cores (AgNPs) coated with a layer of CdSe quantum dots (QDs) have been studied by Raman spectroscopy. The hybrid nanoparticles were prepared via electrostatic interaction by mixing aqueous suspensions of QDs and AgNPs, where opposite charges on the AgNPs and QDs surfaces were induced by opportunely selected capping agents. Assemblies of such hybrid nanoparticles show an increased intensity of the Raman spectrum of up to 500 times, when compared to that of the sole QDs. This enhancement is attributed to the SERS effect (Surface-enhanced Raman scattering). Such enhancement of the Raman modes suggests several opportunities for further research, both in imaging and sensing applications.

Automated Hybrid Microwave Heating for Lunar Surface Solidification, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — This SBIR project addresses the need for a system that will provide automated lunar surface stabilization via hybrid microwave heating. Surface stabilization is...

Bloch-Surface-Polariton-Based Hybrid Nanowire Structure for Subwavelength, Low-Loss Waveguiding

Directory of Open Access Journals (Sweden)

Weijing Kong

2018-03-01

Full Text Available Surface plasmon polaritons (SPPs have been thoroughly studied in the past decades for not only sensing but also waveguiding applications. Various plasmonic device structures have been explored due to their ability to confine their optical mode to the subwavelength level. However, with the existence of metal, the large ohmic loss limits the propagation distance of the SPP and thus the scalability of such devices. Therefore, different hybrid waveguides have been proposed to overcome this shortcoming. Through fine tuning of the coupling between the SPP and a conventional waveguide mode, a hybrid mode could be excited with decent mode confinement and extended propagation distance. As an effective alternative of SPP, Bloch surface waves have been re-investigated more recently for their unique advantages. As is supported in all-dielectric structures, the optical loss for the Bloch surface wave is much lower, which stands for a much longer propagating distance. Yet, the confinement of the Bloch surface wave due to the reflections and refractions in the multilayer structure is not as tight as that of the SPP. In this work, by integrating a periodic multilayer structure that supports the Bloch surface wave with a metallic nanowire structure, a hybrid Bloch surface wave polariton could be excited. With the proposed hybrid nanowire structure, a hybrid mode is demonstrated with the deep subwavelength mode confinement and a propagation distance of tens of microns.

Political control on the Internet in the context of a hybrid regime. Venezuela 2007-2015

Directory of Open Access Journals (Sweden)

Iria Puyosa

2015-12-01

Full Text Available This article presents a case study on control policies on the field of the internet and the social web, developed by the Venezuelan government, between 2007 and 2015. The case study includes examination of key documents of public policy for internet by Venezuelan State, industry statistics and data provided by previous research, as well as systematization of empirical events that reflect the characteristics of the practices of political control on the web that were implemented by the Venezuelan State. The study examines whether the data substantiate the hypotheses of the "dictator's dilemma" (Kerr, 2014 in a hybrid political regime as Venezuela.

Ideal and non-ideal MHD regimes of wire array implosion obtained in 3D hybrid simulations and observed during experiments at NTF (Nevada Terawatt Facility)

International Nuclear Information System (INIS)

Sotnikov, Vladimir Isaakovich; Fiala, V.; Oliver, Bryan Velten; Ivanov, Vladimir V.; LePell, Paul David; Fedin, Dmitry; Mehlhorn, Thomas Alan; Kantsyrev, Victor Leonidovich; Coverdale, Christine Anne; Travnicek, P.; Hellinger, P.; Deeney, Christopher; Jones, Brent Manley; Safronova, Alla S.; Leboeuf, J.N.; Cowan, Thomas E.

2004-01-01

Recent 3D hybrid simulation of a plasma current-carrying column revealed two regimes of sausage and kink instability development. In the first regime, with small Hall parameter, development of instabilities leads to appearance of large-scale axial perturbations and eventually to the bending of the plasma column. In the second regime, with five times larger Hall parameter, small-scale perturbations dominated and no bending of the plasma column was observed. Simulation results are compared to recent experimental data, including laser probing, x-ray spectroscopy and time-gated x-ray imaging during wire array implosions at NTF

Effect of surface modification and hybridization on dynamic ...

Indian Academy of Sciences (India)

Epoxy; Roystonea regia; glass; surface modification; hybridization; dynamic mechanical ... other advantages such as light weight, low cost, high specific ... ful technique to study the mechanical behaviour of mate- ... The test reveals response.

Pool-Boiling Heat-Transfer Enhancement on Cylindrical Surfaces with Hybrid Wettable Patterns.

Science.gov (United States)

Kumar C S, Sujith; Chang, Yao Wen; Chen, Ping-Hei

2017-04-10

In this study, pool-boiling heat-transfer experiments were performed to investigate the effect of the number of interlines and the orientation of the hybrid wettable pattern. Hybrid wettable patterns were produced by coating superhydrophilic SiO2 on a masked, hydrophobic, cylindrical copper surface. Using de-ionized (DI) water as the working fluid, pool-boiling heat-transfer studies were conducted on the different surface-treated copper cylinders of a 25-mm diameter and a 40-mm length. The experimental results showed that the number of interlines and the orientation of the hybrid wettable pattern influenced the wall superheat and the HTC. By increasing the number of interlines, the HTC was enhanced when compared to the plain surface. Images obtained from the charge-coupled device (CCD) camera indicated that more bubbles formed on the interlines as compared to other parts. The hybrid wettable pattern with the lowermost section being hydrophobic gave the best heat-transfer coefficient (HTC). The experimental results indicated that the bubble dynamics of the surface is an important factor that determines the nucleate boiling.

TiO2 micro-nano-hybrid surface to alleviate biological aging of UV-photofunctionalized titanium.

Science.gov (United States)

Iwasa, Fuminori; Tsukimura, Naoki; Sugita, Yoshihiko; Kanuru, Rajita Kodali; Kubo, Katsutoshi; Hasnain, Hafiz; Att, Wael; Ogawa, Takahiro

2011-01-01

Bioactivity and osteoconductivity of titanium degrade over time after surface processing. This time-dependent degradation is substantial and defined as the biological aging of titanium. UV treatment has shown to reactivate the aged surfaces, a process known as photofunctionalization. This study determined whether there is a difference in the behavior of biological aging for titanium with micro-nano-hybrid topography and titanium with microtopography alone, following functionalization. Titanium disks were acid etched to create micropits on the surface. Micro-nano-hybrid surfaces were created by depositioning 300-nm diameter TiO(2) nodules onto the micropits using a previously established self-assembly protocol. These disks were stored for 8 weeks in the dark to allow sufficient aging, then treated with UV light for 48 hours. Rat bone marrow-derived osteoblasts were cultured on fresh disks (immediately after UV treatment), 3-day-old disks (disks stored for 3 days after UV treatment), and 7-day- old disks. The rates of cell attachment, spread, proliferation, and levels of alkaline phosphatase activity, and calcium deposition were reduced by 30%-50% on micropit surfaces, depending on the age of the titanium. In contrast, 7-day-old hybrid surfaces maintained equivalent levels of bioactivity compared with the fresh surfaces. Both micropit and micro-nano-hybrid surfaces were superhydrophilic immediately after UV treatment. However, after 7 days, the micro-nano- hybrid surfaces became hydrorepellent, while the micropit surfaces remained hydrophilic. The sustained bioactivity levels of the micro-nano-hybrid surfaces were nullified by treating these surfaces with Cl(-)anions. A thin TiO(2) coating on the micropit surface without the formation of nanonodules did not result in the prevention or alleviation of the time-dependent decrease in biological activity. In conclusion, the micro-nano-hybrid titanium surfaces may slow the rate of time-dependent degradation of titanium

Polyaniline hybridized surface defective ZnO nanorods with long-term stable photoelectrochemical activity

International Nuclear Information System (INIS)

Bera, Susanta; Khan, Hasmat; Biswas, Indranil; Jana, Sunirmal

2016-01-01

Highlights: • Polyaniline (PANI) hybridized ZnO nanorods was synthesized by solution method. • Surface defects were found in the nanorods. • The hybrid material exhibited an enhancement in visible light absorption. • A long-term stable photoelectrochemical activity of the material was found. • Advancement in the properties would be PANI hybridization and surface defects. - Abstract: We report surfactant/template free precursor solution based synthesis of polyaniline (PANI) hybridized surface defective ZnO nanorods by a two-step process. Initially, ZnO nanorods have been prepared at 95 °C, followed by hybridization (coating) of PANI onto the ZnO via in situ polymerization of aniline monomer, forming ZnO-PANI nanohybrid (ZP). The structural properties of ZP have been analyzed by X-ray diffraction (XRD) and transmission electron microscopic (TEM) studies. The presence of surface defects especially the oxygen vacancies in ZnO has been characterized by photoluminescence emission, high resolution TEM, X-ray photoelectron spectroscopy (XPS) and micro-Raman spectral measurements. The chemical interaction of PANI with ZnO has been examined by Fourier transform infrared (FTIR) and XPS analyses. A significant enhancement in visible absorption of ZP sample is found as evidenced from UV–vis diffused reflectance spectral study. BET nitrogen adsorption-desorption isotherm shows an improved textural property (pore size, pore volume) of ZP. Moreover, a long-term stable photoelectrochemical activity (PEC) of ZP is found compare to pristine ZnO. The synergic effect of PANI hybridization and the presence of surface defects in ZnO NRs can enhance the PEC by prolonging the recombination rate of photogenerated charge carriers. The effect can also provide large number of active sites to make electrolyte diffusion and mass transportation easier in the nanohybrid. This simple synthesis strategy can be adopted for PANI hybridization with different metal oxide semiconductors

Polyaniline hybridized surface defective ZnO nanorods with long-term stable photoelectrochemical activity

Energy Technology Data Exchange (ETDEWEB)

Bera, Susanta; Khan, Hasmat [Sol-Gel Division, CSIR-Central Glass and Ceramic Research Institute (CSIR-CGCRI), 196 Raja S.C. Mullick Road, P.O. Jadavpur University, Kolkata 700 032, West Bengal (India); Biswas, Indranil [Materials Characterization and Instrumentation Division, CSIR-Central Glass and Ceramic Research Institute (CSIR-CGCRI), 196 Raja S.C. Mullick Road, P.O. Jadavpur University, Kolkata 700 032, West Bengal (India); Jana, Sunirmal, E-mail: sjana@cgcri.res.in [Sol-Gel Division, CSIR-Central Glass and Ceramic Research Institute (CSIR-CGCRI), 196 Raja S.C. Mullick Road, P.O. Jadavpur University, Kolkata 700 032, West Bengal (India)

2016-10-15

Highlights: • Polyaniline (PANI) hybridized ZnO nanorods was synthesized by solution method. • Surface defects were found in the nanorods. • The hybrid material exhibited an enhancement in visible light absorption. • A long-term stable photoelectrochemical activity of the material was found. • Advancement in the properties would be PANI hybridization and surface defects. - Abstract: We report surfactant/template free precursor solution based synthesis of polyaniline (PANI) hybridized surface defective ZnO nanorods by a two-step process. Initially, ZnO nanorods have been prepared at 95 °C, followed by hybridization (coating) of PANI onto the ZnO via in situ polymerization of aniline monomer, forming ZnO-PANI nanohybrid (ZP). The structural properties of ZP have been analyzed by X-ray diffraction (XRD) and transmission electron microscopic (TEM) studies. The presence of surface defects especially the oxygen vacancies in ZnO has been characterized by photoluminescence emission, high resolution TEM, X-ray photoelectron spectroscopy (XPS) and micro-Raman spectral measurements. The chemical interaction of PANI with ZnO has been examined by Fourier transform infrared (FTIR) and XPS analyses. A significant enhancement in visible absorption of ZP sample is found as evidenced from UV–vis diffused reflectance spectral study. BET nitrogen adsorption-desorption isotherm shows an improved textural property (pore size, pore volume) of ZP. Moreover, a long-term stable photoelectrochemical activity (PEC) of ZP is found compare to pristine ZnO. The synergic effect of PANI hybridization and the presence of surface defects in ZnO NRs can enhance the PEC by prolonging the recombination rate of photogenerated charge carriers. The effect can also provide large number of active sites to make electrolyte diffusion and mass transportation easier in the nanohybrid. This simple synthesis strategy can be adopted for PANI hybridization with different metal oxide semiconductors

Delayed frost formation on hybrid nanostructured surfaces with patterned high wetting contrast

Science.gov (United States)

Hou, Youmin; Zhou, Peng; Yao, Shuhuai

2014-11-01

Engineering icephobic surfaces that can retard the frost formation and accumulation are important to vehicles, wind turbines, power lines, and HVAC systems. For condensation frosting, superhydrophobic surfaces promote self-removal of condensed droplets before freezing and consequently delay the frost growth. However, a small thermal fluctuation may lead to a Cassie-to-Wenzel transition, and thus dramatically enhance the frost formation and adhesion. In this work, we investigated the heterogeneous ice nucleation on hybrid nanostructured surfaces with patterned high wetting contrast. By judiciously introducing hydrophilic micro-patches into superhydrophobic nanostructured surface, we demonstrated that such a novel hybrid structure can efficiently defer the ice nucleation as compared to a superhydrophobic surface with nanostructures only. We observed efficient droplet jumping and higher coverage of droplets with diameter smaller than 10 μm, both of which suppress frost formation. The hybrid surface avoids the formation of liquid-bridges for Cassie-to-Wenzel transition, therefore eliminating the `bottom-up' droplet freezing from the cold substrate. These findings provide new insights to improve anti-frosting and anti-icing by using heterogeneous wettability in multiscale structures.

Hybrid Back Surface Reflector GaInAsSb Thermophotovoltaic Devices

International Nuclear Information System (INIS)

RK Huang; CA Wang; MK Connors; GW Turner; M Dashiell

2004-01-01

Back surface reflectors have the potential to improve thermophotovoltaic (TPV) device performance though the recirculation of infrared photons. The ''hybrid'' back-surface reflector (BSR) TPV cell approach allows one to construct BSRs for TPV devices using conventional, high efficiency, GaInAsSb-based TPV material. The design, fabrication, and measurements of hybrid BSR-TPV cells are described. The BSR was shown to provide a 4 mV improvement in open-circuit voltage under a constant shortcircuit current, which is comparable to the 5 mV improvement theoretically predicted. Larger improvements in open-circuit voltage are expected in the future with materials improvements

On the capillary restriction in start-up regimes of liquid metal evaporation from capillary-porous surfaces

International Nuclear Information System (INIS)

Prosvetov, V.V.

1979-01-01

Evaporation of liquid metals from capillary-porous structures is one of the most effective methods of surface cooling, to which essential heat quantity is delivered at high temperatures. The paper deals with heat flux limitation, caused by incapability of core capillary forces to overcome pressure differential in heat carrier circulation shape in such evaporation regimes, when average length of free path of vapour molecule exceeds core cell size. Suggested are theoretical correlations for determination of critical heat flux density and temperature of liquid surface in starting regimes of liquid metal evaporation from rectangular slots and compound cores with screens made of foil with round perforations. The catculative and experimental values of critical heat flux density in starting regimes of sodium evaporation from rectangular slots satisfactorily agree with each other

Development of a High Slip-resistant Footwear Outsole Using a Hybrid Rubber Surface Pattern

Science.gov (United States)

YAMAGUCHI, Takeshi; HOKKIRIGAWA, Kazuo

2014-01-01

Abstract: The present study examined whether a new footwear outsole with tread blocks and a hybrid rubber surface pattern, composed of rough and smooth surfaces, could increase slip resistance and reduce the risk of fall while walking on a wet floor surface. A drag test was performed to measure static and dynamic coefficient of friction (SCOF and DCOF, respectively) values for the footwear with the hybrid rubber surface pattern outsole and two types of commercially available boots that are conventionally used in food factories and restaurant kitchens with respect to a stainless steel floor covered with glycerol solution. Gait trials were conducted with 14 participants who wore the footwear on the wet stainless steel floor. The drag test results indicated that the hybrid rubber surface pattern sole exhibited higher SCOF (≥0.44) and DCOF (≥0.39) values than the soles of the comparative footwear (pfootwear with the hybrid rubber surface pattern outsole were significantly lower than those for the comparative footwear, which resulted in no falls during trials. PMID:25055846

Thermoluminescence study of the trapped charge at an alumina surface electrode in different dielectric barrier discharge regimes

Energy Technology Data Exchange (ETDEWEB)

Ambrico, P F; Ambrico, M; Dilecce, G; De Benedictis, S [Consiglio Nazionale delle Ricerche, Istituto di Metodologie Inorganiche e dei Plasmi UOS Bari-c/o Dipartimento di Chimica, Universita degli Studi di Bari ' Aldo Moro' , via Orabona, 4, 70126 Bari (Italy); Colaianni, A [Dipartimento di Geologia e Geofisica, Universita degli Studi di Bari ' Aldo Moro' , via Orabona, 4, 70126 Bari (Italy); Schiavulli, L, E-mail: paolofrancesco.ambrico@cnr.i [Dipartimento Interateneo di Fisica, Universita degli Studi di Bari ' Aldo Moro' , via Orabona, 4, 70126 Bari (Italy)

2010-08-18

In this study, the charge trapping effect in alumina dielectric surfaces has been deeply investigated by means of a dedicated dielectric barrier discharge apparatus in different discharge regimes and gas mixtures. This work further validates our previous findings in the case of air discharges in a filamentary regime. Long lasting charge trapping has been evidenced by ex situ thermoluminescence characterizations of alumina dielectric barrier plates exposed to a plasma. The density of trapped surface charges was found to be higher in the glow discharge with respect to pseudo-glow and filamentary regimes, and for all regimes the minimum trap activation temperature was 390 K and the trap energy was less than or around 1 eV. This implies that in the case of glow discharges a higher reservoir of electrons is present. Also, the effect was found to persist for several days after running the discharge.

Thermoluminescence study of the trapped charge at an alumina surface electrode in different dielectric barrier discharge regimes

International Nuclear Information System (INIS)

Ambrico, P F; Ambrico, M; Dilecce, G; De Benedictis, S; Colaianni, A; Schiavulli, L

2010-01-01

In this study, the charge trapping effect in alumina dielectric surfaces has been deeply investigated by means of a dedicated dielectric barrier discharge apparatus in different discharge regimes and gas mixtures. This work further validates our previous findings in the case of air discharges in a filamentary regime. Long lasting charge trapping has been evidenced by ex situ thermoluminescence characterizations of alumina dielectric barrier plates exposed to a plasma. The density of trapped surface charges was found to be higher in the glow discharge with respect to pseudo-glow and filamentary regimes, and for all regimes the minimum trap activation temperature was 390 K and the trap energy was less than or around 1 eV. This implies that in the case of glow discharges a higher reservoir of electrons is present. Also, the effect was found to persist for several days after running the discharge.

Surface Restructuring of Hybrid Perovskite Crystals

KAUST Repository

Banavoth, Murali

2016-11-07

Hybrid perovskite crystals have emerged as an important class of semiconductors because of their remarkable performance in optoelectronics devices. The interface structure and chemistry of these crystals are key determinants of the device\\'s performance. Unfortunately, little is known about the intrinsic properties of the surfaces of perovskite materials because extrinsic effects, such as complex microstructures, processing conditions, and hydration under ambient conditions, are thought to cause resistive losses and high leakage current in solar cells. We reveal the intrinsic structural and optoelectronic properties of both pristinely cleaved and aged surfaces of single crystals. We identify surface restructuring on the aged surfaces (visualized on the atomic-scale by scanning tunneling microscopy) that lead to compositional and optical bandgap changes as well as degradation of carrier dynamics, photocurrent, and solar cell device performance. The insights reported herein clarify the key variables involved in the performance of perovskite-based solar cells and fabrication of high-quality surface single crystals, thus paving the way toward their future exploitation in highly efficient solar cells.

Friction Regimes of Water-Lubricated Diamond (111): Role of Interfacial Ether Groups and Tribo-Induced Aromatic Surface Reconstructions

Science.gov (United States)

Kuwahara, Takuya; Moras, Gianpietro; Moseler, Michael

2017-09-01

Large-scale quantum molecular dynamics of water-lubricated diamond (111) surfaces in sliding contact reveals multiple friction regimes. While water starvation causes amorphization of the tribological interface, small H2O traces are sufficient to preserve crystallinity. This can result in high friction due to cold welding via ether groups or in ultralow friction due to aromatic surface passivation triggered by tribo-induced Pandey reconstruction. At higher water coverage, Grotthuss-type diffusion and H2O dissociation yield dense H /OH surface passivation leading to another ultralow friction regime.

Oxygen exchange at gas/oxide interfaces: how the apparent activation energy of the surface exchange coefficient depends on the kinetic regime.

Science.gov (United States)

Fielitz, Peter; Borchardt, Günter

2016-08-10

In the dedicated literature the oxygen surface exchange coefficient KO and the equilibrium oxygen exchange rate [Fraktur R] are considered to be directly proportional to each other regardless of the experimental circumstances. Recent experimental observations, however, contradict the consequences of this assumption. Most surprising is the finding that the apparent activation energy of KO depends dramatically on the kinetic regime in which it has been determined, i.e. surface exchange controlled vs. mixed or diffusion controlled. This work demonstrates how the diffusion boundary condition at the gas/solid interface inevitably entails a correlation between the oxygen surface exchange coefficient KO and the oxygen self-diffusion coefficient DO in the bulk ("on top" of the correlation between KO and [Fraktur R] for the pure surface exchange regime). The model can thus quantitatively explain the range of apparent activation energies measured in the different regimes: in the surface exchange regime the apparent activation energy only contains the contribution of the equilibrium exchange rate, whereas in the mixed or in the diffusion controlled regime the contribution of the oxygen self-diffusivity has also to be taken into account, which may yield significantly higher apparent activation energies and simultaneously quantifies the correlation KO ∝ DO(1/2) observed for a large number of oxides in the mixed or diffusion controlled regime, respectively.

Shear-bond-strength of orthodontic brackets to aged nano-hybrid composite-resin surfaces using different surface preparation.

Science.gov (United States)

Demirtas, Hatice Kubra; Akin, Mehmet; Ileri, Zehra; Basciftci, Faruk Ayhan

2015-01-01

The aim of this study was to evaluate the effects of different surface preparation methods on the shear bond strength (SBS) of orthodontic metal brackets to aged nano-hybrid resin composite surfaces in vitro. A total of 100 restorative composite resin discs, 6 mm in diameter and 3 mm thick, were obtained and treated with an ageing procedure. After ageing, the samples were randomly divided as follows according to surface preparation methods: (1)Control, (2)37% phosphoric acid gel, (3)Sandblasting, (4)Diamond bur, (5)Air-flow and 20 central incisor teeth were used for the control etched group. SBS test were applied on bonded metal brackets to all samples. SBS values and residual adhesives were evaluated. Analysis of variance showed a significant difference (porthodontic metal brackets to nano-hybrid composite resin surfaces.

Development of a High Slip-resistant Footwear Outsole Using a Hybrid Rubber Surface Pattern

OpenAIRE

YAMAGUCHI, Takeshi; HOKKIRIGAWA, Kazuo

2014-01-01

Abstract: The present study examined whether a new footwear outsole with tread blocks and a hybrid rubber surface pattern, composed of rough and smooth surfaces, could increase slip resistance and reduce the risk of fall while walking on a wet floor surface. A drag test was performed to measure static and dynamic coefficient of friction (SCOF and DCOF, respectively) values for the footwear with the hybrid rubber surface pattern outsole and two types of commercially available boots that are co...

TiO2 micro-nano-hybrid surface to alleviate biological aging of UV-photofunctionalized titanium

Directory of Open Access Journals (Sweden)

Iwasa F

2011-06-01

Full Text Available Fuminori Iwasa1, Naoki Tsukimura1, Yoshihiko Sugita1, Rajita Kodali Kanuru1, Katsutoshi Kubo1, Hafiz Hasnain1, Wael Att1,2, Takahiro Ogawa11Laboratory of Bone and Implant Sciences (LBIS, The Weintraub Center for Reconstructive Biotechnology, Division of Advanced Prosthodontics, Biomaterials and Hospital Dentistry, UCLA School of Dentistry, Los Angeles, CA, USA; 2Department of Prosthodontics, Dental School, Albert-Ludwigs University, Freiburg, GermanyAbstract: Bioactivity and osteoconductivity of titanium degrade over time after surface processing. This time-dependent degradation is substantial and defined as the biological aging of titanium. UV treatment has shown to reactivate the aged surfaces, a process known as photofunctionalization. This study determined whether there is a difference in the behavior of biological aging for titanium with micro-nano-hybrid topography and titanium with microtopography alone, following functionalization. Titanium disks were acid etched to create micropits on the surface. Micro-nano-hybrid surfaces were created by depositioning 300-nm diameter TiO2 nodules onto the micropits using a previously established self-assembly protocol. These disks were stored for 8 weeks in the dark to allow sufficient aging, then treated with UV light for 48 hours. Rat bone marrow–derived osteoblasts were cultured on fresh disks (immediately after UV treatment, 3-day-old disks (disks stored for 3 days after UV treatment, and 7-day-old disks. The rates of cell attachment, spread, proliferation, and levels of alkaline phosphatase activity, and calcium deposition were reduced by 30%–50% on micropit surfaces, depending on the age of the titanium. In contrast, 7-day-old hybrid surfaces maintained equivalent levels of bioactivity compared with the fresh surfaces. Both micropit and micro-nano-hybrid surfaces were superhydrophilic immediately after UV treatment. However, after 7 days, the micro-nano-hybrid surfaces became hydrorepellent

Transition from weak wave turbulence regime to solitonic regime

Science.gov (United States)

Hassani, Roumaissa; Mordant, Nicolas

2017-11-01

The Weak Turbulence Theory (WTT) is a statistical theory describing the interaction of a large ensemble of random waves characterized by very different length scales. For both weak non-linearity and weak dispersion a different regime is predicted where solitons propagate while keeping their shape unchanged. The question under investigation here is which regime between weak turbulence or soliton gas does the system choose ? We report an experimental investigation of wave turbulence at the surface of finite depth water in the gravity-capillary range. We tune the wave dispersion and the level of nonlinearity by modifying the depth of water and the forcing respectively. We use space-time resolved profilometry to reconstruct the deformed surface of water. When decreasing the water depth, we observe a drastic transition between weak turbulence at the weakest forcing and a solitonic regime at stronger forcing. We characterize the transition between both states by studying their Fourier Spectra. We also study the efficiency of energy transfer in the weak turbulence regime. We report a loss of efficiency of angular transfer as the dispersion of the wave is reduced until the system bifurcates into the solitonic regime. This project has recieved funding from the European Research Council (ERC, Grant Agreement No. 647018-WATU).

Electronic transport in bismuth selenide in the topological insulator regime

Science.gov (United States)

Kim, Dohun

The 3D topological insulators (TIs) have an insulating bulk but spin-momentum coupled metallic surface states stemming from band inversion due to strong spin-orbit interaction, whose existence is guaranteed by the topology of the band structure of the insulator. While the STI surface state has been studied spectroscopically by e.g. photoemission and scanned probes, transport experiments have failed to demonstrate clear signature of the STI due to high level of bulk conduction. In this thesis, I present experimental results on the transport properties of TI material Bi2Se3 in the absence of bulk conduction (TI regime), achieved by applying novel p-type doping methods. Field effect transistors consisting of thin (thickness: 5-17 nm) Bi2Se3 are fabricated by mechanical exfoliation of single crystals, and a combination of conventional dielectric (300 nm thick SiO2) and electrochemical or chemical gating methods are used to move the Fermi energy through the surface Dirac point inside bulk band gap, revealing the ambipolar gapless nature of transport in the Bi2Se3 surface states. The minimum conductivity of the topological surface state is understood within the self-consistent theory of Dirac electrons in the presence of charged impurities. The intrinsic finite-temperature resistivity of the topological surface state due to electron-acoustic phonon scattering is measured to be 60 times larger than that of graphene largely due to the smaller Fermi and sound velocities in Bi2Se 3, which will have implications for topological electronic devices operating at room temperature. Along with semi-classical Boltzmann transport, I also discuss 2D weak anti-localization (WAL) behavior of the topological surface states. By investigating gate-tuned WAL behavior in thin (5-17 nm) TI films, I show that WAL in the TI regime is extraordinarily sensitive to the hybridization induced quantum mechanical tunneling between top and bottom topological surfaces, and interplay of phase coherence

Genotype dependant callogenic and morphogenic response of lycopersicon esculentum hybrids

International Nuclear Information System (INIS)

Jatoi, S.A.; Sajid, G.M.; Ahmad, S.; Anwar, R.; Munir, M.

2002-01-01

Leaf explants from field grown F1 hybrids of Lycopersicon esculentum, namely Bornia and Royesta were cultured on MS media containing 5 x 5 diallelic combinations of IAA and Kin at 0, 4, 8, 12 and 16 micro M/l each. Callogenesis, root and shoot regeneration potential of these hybrids were compared on these hormonal regimes. Royesta exhibited better callogenesis response (85%) than Bornia (72%). However, callogenesis on a given hormonal regime was genotype dependant. Root and shoot regeneration was better in case of Bornia than in Royesta. Hybrid Bornia produced shoots much more frequently (6-14%) on many diverse hormonal regimes than Royesta which produced shoots only rarely (5%) on a single hormonal regime. (author)

Hybrid fuzzy logic control of laser surface heat treatments

International Nuclear Information System (INIS)

Perez, Jose Antonio; Ocana, Jose Luis; Molpeceres, Carlos

2007-01-01

This paper presents an advanced hybrid fuzzy logic control system for laser surface heat treatments, which allows to increase significantly the uniformity and final quality of the obtained product, reducing the rejection rate and increasing the productivity and efficiency of the treatment. Basically, the proposed hybrid control structure combines a fuzzy logic controller, with a pure integral action, both fully decoupled, improving the performances of the process with a reasonable design cost, since the system nonlinearities are fully compensated by the fuzzy component of the controller, while the integral action contributes to eliminate the steady-state error

Surface plasmon enhanced quantum transport in a hybrid metal nanoparticle array

International Nuclear Information System (INIS)

Sun, Lin; Nan, Yali; Xu, Shang; Zhang, Sishi; Han, Min

2014-01-01

Hybrid Pd–Ag nanoparticle arrays composed of randomly distributed Pd nanoparticles in dense packing and a small number of dispersed Ag nanoparticles were fabricated with controlled coverage. Photo-enhanced conductance was observed in the nanoparticle arrays. Largest enhancement, which can be higher than 20 folds, was obtained with 450 nm light illumination. This wavelength was found to correlate with the surface plasmon resonance of the Ag nanoparticles. Electron transport measurements showed there were significant Coulomb blockade in the nanoparticle arrays and the blockade could be overcome with the surface plasmon enhanced local field of Ag nanoparticles induced by light illumination. - Highlights: • We study photo-enhanced electron conductance of a hybrid Pd–Ag nanoparticle array. • The light-induced conductance enhancement is as high as 20 folds at 10 K. • The enhancement is correlate with the surface plasmon resonance of Ag nanoparticles. • Coulomb blockades is overcome with the surface plasmon enhanced local field

Fast Ion Redistribution and Implications for the Hybrid Regime

International Nuclear Information System (INIS)

Nazikian, R.; Austin, M.E.; Budny, R.V.; Chu, M.S.; Heidbrink, W.W.; Makowski, M.A.; Petty, C.C.; Politzer, P.A.; Solomon, W.M.; Van Zeeland, M.A.

2007-01-01

Time dependent TRANSP analysis indicates that radial redistribution of fast ions is unlikely to affect the central current density in hybrid plasmas sufficient to raise q(0) above unity. The results suggest that some other mechanism other than fast ion transport must be involved in raising q(0) and preventing sawteeth in hybrid plasmas.

The illusion of specific capture: surface and solution studies of suboptimal oligonucleotide hybridization

Science.gov (United States)

2013-01-01

Background Hybridization based assays and capture systems depend on the specificity of hybridization between a probe and its intended target. A common guideline in the construction of DNA microarrays, for instance, is that avoiding complementary stretches of more than 15 nucleic acids in a 50 or 60-mer probe will eliminate sequence specific cross-hybridization reactions. Here we present a study of the behavior of partially matched oligonucleotide pairs with complementary stretches starting well below this threshold complementarity length – in silico, in solution, and at the microarray surface. The modeled behavior of pairs of oligonucleotide probes and their targets suggests that even a complementary stretch of sequence 12 nt in length would give rise to specific cross-hybridization. We designed a set of binding partners to a 50-mer oligonucleotide containing complementary stretches from 6 nt to 21 nt in length. Results Solution melting experiments demonstrate that stable partial duplexes can form when only 12 bp of complementary sequence are present; surface hybridization experiments confirm that a signal close in magnitude to full-strength signal can be obtained from hybridization of a 12 bp duplex within a 50mer oligonucleotide. Conclusions Microarray and other molecular capture strategies that rely on a 15 nt lower complementarity bound for eliminating specific cross-hybridization may not be sufficiently conservative. PMID:23445545

Evaluation of Surface Characteristics of Denture Base Using Organic-Inorganic Hybrid Coating: An SEM Study.

Science.gov (United States)

Aa, Jafari; Mh, Lotfi-Kamran; M, Ghafoorzadeh; Sm, Shaddel

2017-06-01

Despite the numerous positive features of acrylic denture base, there are a number of undeniable associated disadvantages. The properties of denture base have been improved through various interventions including application of different types of filler and coatings. This study aimed to evaluate the surface roughness, thickness and coating quality of organic-inorganic coating on the denture base through scanning electron microscopy. Moreover, the colour change was evaluated visually. The organic-inorganic hybrid coatings were prepared. Acrylic discs of 10×10 mm were fabricated. The test discs were dipped in the hybrid coating and cured. In order to evaluate the surface roughness and coating thickness, the surface and cross-section of the samples in both coated and control groups were subjected to scanning electron microscopy. The colour change and transparency were visually evaluated with naked eyes. The data were statistically analyzed by student's t test. The hybrid materials perfectly covered all the surfaces of acrylic resin and established proper thickness. The coated group seemed smoother and flatter than the control group; however, the difference was not statistically significant ( for all parameters p > 0.05). It was quite a thin coating and no perceptible colour change was observed. The hybrid coating maintained good binding, caused no noticeable discoloration, and thoroughly covered the acrylic resin surface with uniform delicate thickness. It also slightly improved the acrylic resin surface roughness.

Cage and linear structured polysiloxane/epoxy hybrids for coatings: Surface property and film permeability.

Science.gov (United States)

Ma, Yanli; He, Ling; Jia, Mengjun; Zhao, Lingru; Zuo, Yanyan; Hu, Pingan

2017-08-15

Three polysiloxane/epoxy hybrids obtained by evolving cage- or linear-structured polysiloxane into poly glycidyl methacrylate (PGMA) matrix are compared used as coatings. One is the cage-structured hybrid of P(GMA/MA-POSS) copolymer obtained by GMA and methacrylisobutyl polyhedral oligomeric silsesquioxane (MA-POSS) via free radical polymerization, the other two are PGMA/NH 2 -POSS and PGMA/NH 2 -PDMS hybrids by cage-structured aminopropyllsobutyl POSS (NH 2 -POSS) or linear-structured diamino terminated poly(dimethylsiloxane) (NH 2 -PDMS) to cure PGMA. The effect of MA-POSS, NH 2 -POSS and NH 2 -PDMS on polysiloxane/epoxy hybrid films is characterized according to their surface morphology, transparency, permeability, adhesive strength and thermo-mechanical properties. Due to caged POSS tending to agglomerate onto the film surface, P(GMA/MA-POSS) and PGMA/NH 2 -POSS films exhibit much more heterogeneous surfaces than PGMA/NH 2 -PDMS film, but the well-compatibility between epoxy matrix and MA-POSS has provided P(GMA/MA-POSS) film with much higher transmittance (98%) than PGMA/NH 2 -POSS film (24%), PGMA/NH 2 -PDMS film (27%) and traditional epoxy resin film (5%). The introduction of polysiloxane into epoxy matrix is confirmed to create hybrids with strong adhesive strength (526-1113N) and high thermos-stability (T g =262-282°C), especially the cage-structured P(GMA/MA-POSS) hybrid (1113N and 282°C), but the flexible PDMS improves PGMA/NH 2 -PDMS hybrid with much higher storage modulus (519MPa) than PGMA/NH 2 -POSS (271MPa), which suggests that PDMS is advantage in improving the film stiffness than POSS cages. However, cage-structured P(GMA/MA-POSS) and PGMA/NH 2 -POSS indicate higher permeability than PGMA/NH 2 -PDMS and traditional epoxy resin. Comparatively, the cage-structured P(GMA/MA-POSS) hybrid is the best coating in transparency, permeability, adhesive strength and thermostability, but linear-structured PGMA/NH 2 -PDMS hybrid behaviors the best coating in

Development of a surface plasmon resonance and nanomechanical biosensing hybrid platform for multiparametric reading.

Science.gov (United States)

Alvarez, Mar; Fariña, David; Escuela, Alfonso M; Sendra, Jose Ramón; Lechuga, Laura M

2013-01-01

We have developed a hybrid platform that combines two well-known biosensing technologies based on quite different transducer principles: surface plasmon resonance and nanomechanical sensing. The new system allows the simultaneous and real-time detection of two independent parameters, refractive index change (Δn), and surface stress change (Δσ) when a biomolecular interaction takes place. Both parameters have a direct relation with the mass coverage of the sensor surface. The core of the platform is a common fluid cell, where the solution arrives to both sensor areas at the same time and under the same conditions (temperature, velocity, diffusion, etc.).The main objective of this integration is to achieve a better understanding of the physical behaviour of the transducers during sensing, increasing the information obtained in real time in one single experiment. The potential of the hybrid platform is demonstrated by the detection of DNA hybridization.

A Transcriptomic Analysis of Cave, Surface, and Hybrid Isopod Crustaceans of the Species Asellus aquaticus.

Directory of Open Access Journals (Sweden)

Bethany A Stahl

Full Text Available Cave animals, compared to surface-dwelling relatives, tend to have reduced eyes and pigment, longer appendages, and enhanced mechanosensory structures. Pressing questions include how certain cave-related traits are gained and lost, and if they originate through the same or different genetic programs in independent lineages. An excellent system for exploring these questions is the isopod, Asellus aquaticus. This species includes multiple cave and surface populations that have numerous morphological differences between them. A key feature is that hybrids between cave and surface individuals are viable, which enables genetic crosses and linkage analyses. Here, we advance this system by analyzing single animal transcriptomes of Asellus aquaticus. We use high throughput sequencing of non-normalized cDNA derived from the head of a surface-dwelling male, the head of a cave-dwelling male, the head of a hybrid male (produced by crossing a surface individual with a cave individual, and a pooled sample of surface embryos and hatchlings. Assembling reads from surface and cave head RNA pools yielded an integrated transcriptome comprised of 23,984 contigs. Using this integrated assembly as a reference transcriptome, we aligned reads from surface-, cave- and hybrid- head tissue and pooled surface embryos and hatchlings. Our approach identified 742 SNPs and placed four new candidate genes to an existing linkage map for A. aquaticus. In addition, we examined SNPs for allele-specific expression differences in the hybrid individual. All of these resources will facilitate identification of genes and associated changes responsible for cave adaptation in A. aquaticus and, in concert with analyses of other species, will inform our understanding of the evolutionary processes accompanying adaptation to the subterranean environment.

Efficient and Anisotropic Fog Harvesting on a Hybrid and Directional Surface

KAUST Repository

Wu, Jinbo

2016-12-05

A straight throughout superhydrophilic track that contains high contrast and directional wettability on a superhydrophobic surface is designed. Despite droplets that tend to slide more easily along a direction parallel to the track, it is found that such hybrid strip-pattern surfaces have higher fog harvesting efficiency along a direction perpendicular to the tracks due to the larger accumulation area for droplet removal.

Design and Fabrication of a Hybrid Superhydrophobic-Hydrophilic Surface That Exhibits Stable Dropwise Condensation.

Science.gov (United States)

Mondal, Bikash; Mac Giolla Eain, Marc; Xu, QianFeng; Egan, Vanessa M; Punch, Jeff; Lyons, Alan M

2015-10-28

Condensation of water vapor is an essential process in power generation, water collection, and thermal management. Dropwise condensation, where condensed droplets are removed from the surface before coalescing into a film, has been shown to increase the heat transfer efficiency and water collection ability of many surfaces. Numerous efforts have been made to create surfaces which can promote dropwise condensation, including superhydrophobic surfaces on which water droplets are highly mobile. However, the challenge with using such surfaces in condensing environments is that hydrophobic coatings can degrade and/or water droplets on superhydrophobic surfaces transition from the mobile Cassie to the wetted Wenzel state over time and condensation shifts to a less-effective filmwise mechanism. To meet the need for a heat-transfer surface that can maintain stable dropwise condensation, we designed and fabricated a hybrid superhydrophobic-hydrophilic surface. An array of hydrophilic needles, thermally connected to a heat sink, was forced through a robust superhydrophobic polymer film. Condensation occurs preferentially on the needle surface due to differences in wettability and temperature. As the droplet grows, the liquid drop on the needle remains in the Cassie state and does not wet the underlying superhydrophobic surface. The water collection rate on this surface was studied using different surface tilt angles, needle array pitch values, and needle heights. Water condensation rates on the hybrid surface were shown to be 4 times greater than for a planar copper surface and twice as large for silanized silicon or superhydrophobic surfaces without hydrophilic features. A convection-conduction heat transfer model was developed; predicted water condensation rates were in good agreement with experimental observations. This type of hybrid superhydrophobic-hydrophilic surface with a larger array of needles is low-cost, robust, and scalable and so could be used for heat

Surface-Induced Hybridization between Graphene and Titanium

Energy Technology Data Exchange (ETDEWEB)

Hsu, Allen L. [MIT (Massachusetts Inst. of Technology), Cambridge, MA (United States).; Koch, Roland J. [Technische Universitat, Chemnitz (Germany); Ong, Mitchell T. [Stanford Univ., CA (United States); Fang, Wenjing [MIT (Massachusetts Inst. of Technology), Cambridge, MA (United States); Hofmann, Mario [MIT (Massachusetts Inst. of Technology), Cambridge, MA (United States); Kim, Ki Kang [MIT (Massachusetts Inst. of Technology), Cambridge, MA (United States).; Seyller, Thomas [Technische Universitat, Chemnitz (Germany); Dresselhaus, Mildred S. [MIT (Massachusetts Inst. of Technology), Cambridge, MA (United States); Reed, Evan J. [Stanford Univ., CA (United States); Kong, Jing [MIT (Massachusetts Inst. of Technology), Cambridge, MA (United States); Palacios, Tomás [MIT (Massachusetts Inst. of Technology), Cambridge, MA (United States)

2014-08-26

Carbon-based materials such as graphene sheets and carbon nanotubes have inspired a broad range of applications ranging from high-speed flexible electronics all the way to ultrastrong membranes. However, many of these applications are limited by the complex interactions between carbon-based materials and metals. In this work, we experimentally investigate the structural interactions between graphene and transition metals such as palladium (Pd) and titanium (Ti), which have been confirmed by density functional simulations. We find that the adsorption of titanium on graphene is more energetically favorable than in the case of most metals, and density functional theory shows that a surface induced p-d hybridization occurs between atomic carbon and titanium orbitals. This strong affinity between the two materials results in a short-range ordered crystalline deposition on top of graphene as well as chemical modifications to graphene as seen by Raman and X-ray photoemission spectroscopy (XPS). This induced hybridization is interface-specific and has major consequences for contacting graphene nanoelectronic devices as well as applications toward metal-induced chemical functionalization of graphene.

A hybrid instrument combining electronic and photonic tunnelling for surface analysis

International Nuclear Information System (INIS)

Pechou, R.; Ajustron, F.; Seine, G.; Coratger, R.; Maurel, C.; Beauvillain, J.

2004-01-01

A PSTM working in the collection mode and based on an STM probe-sample regulation scheme has been developed. This original hybrid instrument for surface analysis uses apertureless metal-coated chemically etched optical fibres. The use of an electronic tunnelling-based feedback loop significantly reduces tip-sample distance and leads to the collection of a high level near-field optical (NFO) signal. A simple amplified photodiode is thus used to perform optical signal acquisition and to draw electromagnetic field maps of sample surfaces. Experimental results on nanostructured gold surfaces are presented

Fabrication of Nano-Micro Hybrid Structures by Replication and Surface Treatment of Nanowires

Directory of Open Access Journals (Sweden)

Yeonho Jeong

2017-07-01

Full Text Available Nanowire structures have attracted attention in various fields, since new characteristics could be acquired in minute regions. Especially, Anodic Aluminum Oxide (AAO is widely used in the fabrication of nanostructures, which has many nanosized pores and well-organized nano pattern. Using AAO as a template for replication, nanowires with a very high aspect ratio can be fabricated. Herein, we propose a facile method to fabricate a nano-micro hybrid structure using nanowires replicated from AAO, and surface treatment. A polymer resin was coated between Polyethylene terephthalate (PET and the AAO filter, roller pressed, and UV-cured. After the removal of aluminum by using NaOH solution, the nanowires aggregated to form a micropattern. The resulting structure was subjected to various surface treatments to investigate the surface behavior and wettability. As opposed to reported data, UV-ozone treatment can enhance surface hydrophobicity because the UV energy affects the nanowire surface, thus altering the shape of the aggregated nanowires. The hydrophobicity of the surface could be further improved by octadecyltrichlorosilane (OTS coating immediately after UV-ozone treatment. We thus demonstrated that the nano-micro hybrid structure could be formed in the middle of nanowire replication, and then, the shape and surface characteristics could be controlled by surface treatment.

Deep electroproduction of exotic hybrid mesons

International Nuclear Information System (INIS)

Anikin, I.V.; Pire, B.; Szymanowski, L.; Teryaev, O.V.; Wallon, S.

2004-01-01

We evaluate the leading order amplitude for the deep exclusive electroproduction of an exotic hybrid meson in the Bjorken regime. We show that, contrarily to naive expectation, this amplitude factorizes at the twist 2 level and thus scales like usual meson electroproduction when the virtual photon and the hybrid meson are longitudinally polarized. Exotic hybrid mesons may thus be studied in electroproduction experiments at JLAB, HERA (HERMES) or CERN (Compass)

The Surface of Hybrid Perovskite Crystals: A Boon or Bane

KAUST Repository

Banavoth, Murali

2017-03-03

Hybrid perovskite single crystals have garnered tremendous research attention and are expected to be next-generation materials for high-efficiency photoactive devices. Therefore, it is fundamentally important to understand the 8 relationship between the optoelectronic properties of these materials and the marginally exploited surface chemistry in ambient air. For instance, a strong surface disorder, including hydration and ion migration, can possibly lead to extremely different optical and electronic properties at the surface compared to the bulk of the single crystal (SC). From this perspective, we evaluate the key variables that underlie the perovskite SC surface restructuring in ambient air and discuss their merits and limitations. In addition, a comprehensive picture of surface disordering, the remarkable change in the charge carrier dynamics and carrier mobility, surface hydration, and the effect of ion migration on the surface behavior will be discussed. Finally, surface passivation methods are highlighted to resolve or overcome the challenges for device integration.

Temperature Dependent Surface Structures and Electronic Properties of Organic-Inorganic Hybrid Perovskite Single Crystals

Science.gov (United States)

Jao, M.-H.; Teague, M. L.; Huang, J.-S.; Tseng, W.-S.; Yeh, N.-C.

Organic-inorganic hybrid perovskites, arising from research of low-cost high performance photovoltaics, have become promising materials not only for solar cells but also for various optoelectronic and spintronic applications. An interesting aspect of the hybrid perovskites is that their material properties, such as the band gap, can be easily tuned by varying the composition, temperature, and the crystalline phases. Additionally, the surface structure is critically important for their optoelectronic applications. It is speculated that different crystalline facets could show different trap densities, thus resulting in microscopically inhomogeneous performance. Here we report direct studies of the surface structures and electronic properties of hybrid perovskite CH3NH3PbI3 single crystals by scanning tunneling microscopy and spectroscopy (STM/STS). We found long-range spatially homogeneous tunneling conductance spectra with a well-defined energy gap of (1.55 +/- 0.1) eV at 300 K in the tetragonal phase, suggesting high quality of the single crystals. The energy gap increased to (1.81 +/- 0.1) eV in the orthorhombic phase, below the tetragonal-to-orthorhombic phase transition temperature at 150 K. Detailed studies of the temperature evolution in the spatially resolved surface structures and local density of states will be discussed to elucidate how these properties may influence the optoelectronic performance of the hybrid perovskites. We thank the support from NTU in Taiwan and from NSF in the US.

Analysis of the Two-Regime Method on Square Meshes

KAUST Repository

Flegg, Mark B.; Chapman, S. Jonathan; Zheng, Likun; Erban, Radek

2014-01-01

The two-regime method (TRM) has been recently developed for optimizing stochastic reaction-diffusion simulations [M. Flegg, J. Chapman, and R. Erban, J. Roy. Soc. Interface, 9 (2012), pp. 859-868]. It is a multiscale (hybrid) algorithm which uses

Spreading of oil on water in the surface-tension regime

Energy Technology Data Exchange (ETDEWEB)

Camp, D.W.; Berg, J.C.

1987-11-01

Data which describe the unidirectional spreading of several pure oils and oil-surfactant mixtures on water in the surface-tension regime are reported. Leading-edge position and profiles of velocity, thickness and film tension are given as functions of time. The data are consistent with the numerical similarity solution of Foda and Cox (1980), although the measured dependence of the film tension on the film thickness often differs from the equilibrium relationship. The configuration of the oil film near the spreading origin may be either a coherent multimolecular layer or a multitude of thinning, outward-moving lenses surrounded by monolayer. The pure oils show an acceleration zone connecting the slow-moving inner region to a fast-moving outer region, while the oil-surfactant mixtures show a much more gradual increase in film velocity.

Hybrid Heat Pipes for Lunar and Martian Surface and High Heat Flux Space Applications

Science.gov (United States)

Ababneh, Mohammed T.; Tarau, Calin; Anderson, William G.; Farmer, Jeffery T.; Alvarez-Hernandez, Angel R.

2016-01-01

Novel hybrid wick heat pipes are developed to operate against gravity on planetary surfaces, operate in space carrying power over long distances and act as thermosyphons on the planetary surface for Lunar and Martian landers and rovers. These hybrid heat pipes will be capable of operating at the higher heat flux requirements expected in NASA's future spacecraft and on the next generation of polar rovers and equatorial landers. In addition, the sintered evaporator wicks mitigate the start-up problems in vertical gravity aided heat pipes because of large number of nucleation sites in wicks which will allow easy boiling initiation. ACT, NASA Marshall Space Flight Center, and NASA Johnson Space Center, are working together on the Advanced Passive Thermal experiment (APTx) to test and validate the operation of a hybrid wick VCHP with warm reservoir and HiK"TM" plates in microgravity environment on the ISS.

Metabolic responses of Eucalyptus species to different temperature regimes

NARCIS (Netherlands)

Mokochinski, Joao Benhur; Mazzafera, Paulo; Sawaya, Alexandra Christine Helena Frankland; Mumm, Roland; Vos, de Ric Cornelis Hendricus; Hall, Robert David

2018-01-01

Species and hybrids of Eucalyptus are the world's most widely planted hardwood trees. They are cultivated across a wide range of latitudes and therefore environmental conditions. In this context, comprehensive metabolomics approaches have been used to assess how different temperature regimes may

As-grown graphene/copper nanoparticles hybrid nanostructures for enhanced intensity and stability of surface plasmon resonance

Science.gov (United States)

Li, Yun-Fei; Dong, Feng-Xi; Chen, Yang; Zhang, Xu-Lin; Wang, Lei; Bi, Yan-Gang; Tian, Zhen-Nan; Liu, Yue-Feng; Feng, Jing; Sun, Hong-Bo

2016-11-01

The transfer-free fabrication of the high quality graphene on the metallic nanostructures, which is highly desirable for device applications, remains a challenge. Here, we develop the transfer-free method by direct chemical vapor deposition of the graphene layers on copper (Cu) nanoparticles (NPs) to realize the hybrid nanostructures. The graphene as-grown on the Cu NPs permits full electric contact and strong interactions, which results in a strong localization of the field at the graphene/copper interface. An enhanced intensity of the localized surface plasmon resonances (LSPRs) supported by the hybrid nanostructures can be obtained, which induces a much enhanced fluorescent intensity from the dye coated hybrid nanostructures. Moreover, the graphene sheets covering completely and uniformly on the Cu NPs act as a passivation layer to protect the underlying metal surface from air oxidation. As a result, the stability of the LSPRs for the hybrid nanostructures is much enhanced compared to that of the bare Cu NPs. The transfer-free hybrid nanostructures with enhanced intensity and stability of the LSPRs will enable their much broader applications in photonics and optoelectronics.

Novel Graphene-Gold Hybrid Nanostructures Constructed via Sulfur Modified Graphene: Preparation and Characterization by Surface and Electrochemical Techniques

International Nuclear Information System (INIS)

Shervedani, Reza Karimi; Amini, Akbar

2014-01-01

Graphical abstract: Graphene nanosheet-gold nanoparticles (GNs-AuNPs) hybrid has been fabricated from sulfur-modified graphene nanosheets (S-GNs) impregnated with HAuCl4 as Au precursor. Application of the GNs-AuNPs hybrid in electrochemical biosensing was demonstrated by immobilization of glucose oxidase as a model on the surface of GCE-ATP-GNs-AuNPs, and then, using it for sensing of glucose. - Highlights: • A new hybrid of GNs-AuNPs is synthesized by using sulfur-modified graphene. • Stability of the hybrid is exceptionally improved in comparison with previous works. • Aminothiophenol mediated fabrication and stabilization of GNs-AuNPs on GCE electrode. • High electrocatalytic activity was observed for O 2 reduction by hybrid. • Activity of the hybrid was originated from synergistic effect and surface roughness. - Abstract: A novel and uniform graphene nanosheet-gold nanoparticles (GNs-AuNPs) hybrid has been fabricated from sulfur-modified graphene nanosheets (S-GNs) impregnated with HAuCl 4 as Au precursor. Physicochemical and morphological characteristics of the GNs-AuNPs hybrids were investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), surface Raman spectroscopy (SRS), and high resolution transmission electron microscopy (HRTEM). The results of the XRD and HRTEM demonstrated well dispersed Au nanoparticles on GNs with an average particle size of less than 10 nm and a narrow size distribution of 6 to 8 nm. A film of GNs-AuNPs hybrid was constructed on a glassy carbon electrode (GCE) through layer-by-layer (LBL) assembly of 4-aminothiphenol (ATP) on GCE, and then, transferring the hybrid to the sulfur function of ATP to form GCE-ATP-GNs-AuNPs modified surface. Application of the GNs-AuNPs hybrid in electrochemical biosensing was demonstrated by immobilization of glucose oxidase (GOx) as a model on the surface of GCE-ATP-GNs-AuNPs, and then, using it for sensing of glucose. The biosensor exhibited a wide linear response

A simple way to achieve bioinspired hybrid wettability surface with micro/nanopatterns for efficient fog collection.

Science.gov (United States)

Yin, Kai; Du, Haifeng; Dong, Xinran; Wang, Cong; Duan, Ji-An; He, Jun

2017-10-05

Fog collection is receiving increasing attention for providing water in semi-arid deserts and inland areas. Inspired by the fog harvesting ability of the hydrophobic-hydrophilic surface of Namib desert beetles, we present a simple, low-cost method to prepare a hybrid superhydrophobic-hydrophilic surface. The surface contains micro/nanopatterns, and is prepared by incorporating femtosecond-laser fabricated polytetrafluoroethylene nanoparticles deposited on superhydrophobic copper mesh with a pristine hydrophilic copper sheet. The as-prepared surface exhibits enhanced fog collection efficiency compared with uniform (super)hydrophobic or (super)hydrophilic surfaces. This enhancement can be tuned by controlling the mesh number, inclination angle, and fabrication structure. Moreover, the surface shows excellent anti-corrosion ability after immersing in 1 M HCl, 1 M NaOH, and 10 wt% NaCl solutions for 2 hours. This work may provide insight into fabricating hybrid superhydrophobic-hydrophilic surfaces for efficient atmospheric water collection.

Fuel cell/electrochemical capacitor hybrid for intermittent high power applications

Energy Technology Data Exchange (ETDEWEB)

Jarvis, L P; Atwater, T B; Cygan, P J [Army Communications-Electronics Command (CECOM), Fort Monmouth, NJ (United States). Research and Development Center

1999-05-01

A hybrid power source was demonstrated to successfully power a simulated power load encountered in portable military electronics and communications equipment. The hybrid system consisted of a 25 W proton exchange membrane fuel cell (PEMFC) stack connected in parallel with a 70 F capacitor bank. The cyclic regime of 18.0 W for 2 min followed by 2.5 W for 18 min was chosen as the baseline for the simulation of power load. The operating potential cut-off voltage for pass/failure was set to 3.0 V. At room temperature (23-25 C), the PEMFC alone could not handle the described baseline regime with the PEMFC operating potential dropping below the cut-off voltage within 10 s. The hybrid, however, continuously powered the same regime for 25 h. Its operating potential never reached the voltage cut-off point, not even during the high load of 18.0 W. The tests with hybrid configuration were aborted after 25 h of operation with no signs of output degradation, suggesting that further extended operation was possible. (orig.)

Dimerization of eosin on nanostructured gold surfaces: Size regime dependence of the small metallic particles

Science.gov (United States)

Ghosh, Sujit Kumar; Pal, Anjali; Nath, Sudip; Kundu, Subrata; Panigrahi, Sudipa; Pal, Tarasankar

2005-08-01

Gold nanoparticles of variable sizes have been exploited to study their influence on the absorption and emission spectral characteristics of eosin, a fluorescent dye. It has been found that smaller particles of gold stimulate J-aggregation of eosin on the surface of metal particles whereas larger particles cannot induce any kind of aggregation amongst the dye molecules. The size regime dependence of the gold nanoparticles has been attributed to the intercluster interactions induced by the dye molecules for smaller gold nanoparticles and consequently, close packing of the dye molecules around the gold surface engenders intermolecular interactions amongst the dye molecules leading to dimerization.

Stability Analysis of an Industrial Gas Compressor Supported by Tilting-Pad Bearings Under Different Lubrication Regimes

DEFF Research Database (Denmark)

Cerda, Alejandro; Santos, Ilmar

2012-01-01

This work is aimed at a theoretical study of the dynamic behavior of a rotor-tilting pad journal bearing (TPJB) system under different lubrication regimes, namely, thermohydrodynamic (THD), elastohydrodynamic (EHD), and hybrid lubrication regime. The rotor modeled corresponds to an industrial com...

Simple surface modification of poly(dimethylsiloxane) for DNA hybridization

Science.gov (United States)

Zhou, Jinwen; Voelcker, Nicolas H.; Ellis, Amanda V.

2010-01-01

Here, we present a simple chemical modification of poly(dimethylsiloxane) (PDMS) by curing a mixture of 2 wt% undecylenic acid (UDA) in PDMS prepolymer on a gold-coated glass slide. This gold slide had been previously pretreated with a self-assembled hydrophilic monolayer of 3-mercaptopropionic acid (MPA). During curing of the UDA∕PDMS prepolymer, the hydrophilic UDA carboxyl moieties diffuses toward the hydrophilic MPA carboxyl moieties on the gold surface. This diffusion of the UDA within the PDMS prepolymer to the surface is a direct result of surface energy minimization. Once completely cured, the PDMS is peeled off the gold substrate, thereby exposing the interfacial carboxyl groups. These groups are then available for subsequent attachment of 5′-amino terminated DNA oligonucleotides via amide linkages. Our results show that the covalently tethered oligonucleotides can successfully capture fluorescein-labeled complementary oligonucleotides via hybridization, which are visualized using fluorescence microscopy. PMID:21264061

Effects of different management regimes on soil erosion and surface runoff in semi-arid to sub-humid rangelands

NARCIS (Netherlands)

Oudenhoven, van A.P.E.; Veerkamp, C.J.; Alkemade, Rob; Leemans, Rik

2015-01-01

Over one billion people's livelihoods depend on dry rangelands through livestock grazing and agriculture. Livestock grazing and other management activities can cause soil erosion, increase surface runoff and reduce water availability. We studied the effects of different management regimes on soil

Role of hybrid ratio in microstructural, mechanical and sliding wear properties of the Al5083/Graphitep/Al2O3p a surface hybrid nanocomposite fabricated via friction stir processing method

International Nuclear Information System (INIS)

Mostafapour Asl, A.; Khandani, S.T.

2013-01-01

Hybrid ratio of each reinforcement phase in hybrid composite can be defined as proportion of its volume to total reinforcement volume of the composite. The hybrid ratio is an important factor which controls the participation extent of each reinforcement phase in overall properties of hybrid composites. Hence, in the present work, surface hybrid nanocomposites of Al5083/Graphite p /Al 2 O 3p with different hybrid ratios were fabricated by friction stir processing method. Subsequently, effect of hybrid ratio on microstructural, mechanical and tribological properties of the nanocomposite was investigated. Optical microscopy and scanning electron microscopy were utilized to perform microstructural observation on the samples. Hardness value measurements, tensile and pin on disk dry sliding wear tests were carried out to investigate effect of hybrid ratio on mechanical and tribological properties of the nanocomposites. Microstructural investigations displayed better distribution with less agglomeration of reinforcement for lower volume fraction of reinforcement for both alumina and graphite particles. Hardness value, yield strength, ultimate tensile strength and wear rate of the nanocomposites revealed a two stage form along with hybrid ratio variation. The results are discussed based on microstructural observations of the nanocomposites and worn surface analyses.

Speed-up of ab initio hybrid Monte Carlo and ab initio path integral hybrid Monte Carlo simulations by using an auxiliary potential energy surface

International Nuclear Information System (INIS)

Nakayama, Akira; Taketsugu, Tetsuya; Shiga, Motoyuki

2009-01-01

Efficiency of the ab initio hybrid Monte Carlo and ab initio path integral hybrid Monte Carlo methods is enhanced by employing an auxiliary potential energy surface that is used to update the system configuration via molecular dynamics scheme. As a simple illustration of this method, a dual-level approach is introduced where potential energy gradients are evaluated by computationally less expensive ab initio electronic structure methods. (author)

Rainfall variability and its influence on surface flow regimes. Examples from the central highlands of Ethiopia

Energy Technology Data Exchange (ETDEWEB)

Osman, M. [Debre Zeit (Ethiopia); Sauerborn, P. [Seminar fuer Geographie und ihre Didaktik, Univ. zu Koeln, Koeln (Germany)

2002-07-01

The article shows results of an international and interdisciplinary project with the title 'Rainfall and its Erosivity in Ethiopia'. Rainfall variability affects the water resource management of Ethiopia. The influence of rainfall variability on flow regimes was investigated using five gauging stations with data availability from 1982-1997. It was confirmed that the variability in rainfall has a direct implication for surface runoff. Surface runoff declined at most of the gauging stations investigated. Therefore, effective water resource management is recommended for the study area. Future research should focus on watershed management which includes land-use and land cover. The question posed here is whether the variability in rainfall significantly affected surface flow in the study area. (orig.)

Regimes of the magnetized Rayleigh endash Taylor instability

International Nuclear Information System (INIS)

Winske, D.

1996-01-01

Hybrid simulations with kinetic ions and massless fluid electrons are used to investigate the linear and nonlinear behavior of the magnetized Rayleigh endash Taylor instability in slab geometry with the plasma subject to a constant gravity. Three regimes are found, which are determined by the magnitude of the complex frequency ω=ω r +iγ. For |ω| i (Ω i = ion gyrofrequency), one finds the typical behavior of the usual fluid regime, namely the development of open-quote open-quote mushroom-head close-quote close-quote spikes and bubbles in the density and a strongly convoluted boundary between the plasma and magnetic field, where the initial gradient is not relaxed much. A second regime, where |ω|∼0.1Ω i , is characterized by the importance of the Hall term. Linearly, the developing flute modes are more finger-like and tilted along the interface; nonlinearly, clump-like structures form, leading to a significant broadening of the interface. The third regime is characterized by unmagnetized ion behavior, with |ω|∼Ω i . Density clumps, rather than flutes, form in the linear stage, while nonlinearly, longer-wavelength modes that resemble those in fluid regime dominate. Finite Larmor radius stabilization of short-wavelength modes is observed in each regime. copyright 1996 American Institute of Physics

Hybrid radiator cooling system

Science.gov (United States)

France, David M.; Smith, David S.; Yu, Wenhua; Routbort, Jules L.

2016-03-15

A method and hybrid radiator-cooling apparatus for implementing enhanced radiator-cooling are provided. The hybrid radiator-cooling apparatus includes an air-side finned surface for air cooling; an elongated vertically extending surface extending outwardly from the air-side finned surface on a downstream air-side of the hybrid radiator; and a water supply for selectively providing evaporative cooling with water flow by gravity on the elongated vertically extending surface.

Effect of surface treatment on mechanical properties of glass fiber/stainless steel wire mesh reinforced epoxy hybrid composites

Energy Technology Data Exchange (ETDEWEB)

N, Karunagaran [S.K.P Engineering College, Tiruvannamalai (India); A, Rajadurai [Anna University, Chennai (India)

2016-06-15

This paper investigates the effect of surface treatment for glass fiber, stainless steel wire mesh on tensile, flexural, inter-laminar shear and impact properties of glass fiber/stainless steel wire mesh reinforced epoxy hybrid composites. The glass fiber fabric is surface treated either by 1 N solution of sulfuric acid or 1 N solution of sodium hydroxide. The stainless steel wire mesh is also surface treated by either electro dissolution or sand blasting. The hybrid composites are fabricated using epoxy resin reinforced with glass fiber and fine stainless steel wire mesh by hand lay-up technique at room temperature. The hybrid composite consisting of acid treated glass fiber and sand blasted stainless steel wire mesh exhibits a good combination of tensile, flexural, inter-laminar shear and impact behavior in comparison with the composites made without any surface treatment. The fine morphological modifications made on the surface of the glass fiber and stainless steel wire mesh enhances the bonding between the resin and reinforcement which inturn improved the tensile, flexural, inter-laminar shear and impact properties.

Enhanced the performance of graphene oxide/polyimide hybrid membrane for CO2 separation by surface modification of graphene oxide using polyethylene glycol

Science.gov (United States)

Wu, Li-guang; Yang, Cai-hong; Wang, Ting; Zhang, Xue-yang

2018-05-01

Polyethylene glycol (PEG) with different molecular weights was first used to modify graphene oxide (GO) samples. Subsequently, polyimide (PI) hybrid membranes containing modified-GO were fabricated via in situ polymerization. The separation performance of these hybrid membranes was evaluated using permeation experiments for CO2 and N2 gases. The morphology characterization showed that PEG with suitable molecular weight could be successfully grafted on the GO surface. PEG modification altered the surface properties of GO and introduced defective structures onto GO surface. This caused strong surface polarity and high free volume of membranes containing PEG-modified GO, thereby improving the separation performance of membranes. The addition of PEG-GO with low molecular weight effectively increased gas diffusion through hybrid membranes. The hybrid membranes containing PEG-GO with large molecular weight had high solubility performance for CO2 gas due to the introduction of numerous polar groups into polymeric membranes. With the loading content of modified GO, the CO2 gas permeability of hybrid membranes initially increased but eventually decreased. The optimal content of modified GO in membranes reached 3.0 wt%. When too much PEG added (exceeding 30 g), some impurities formed on GO surface and some aggregates appeared in the resulting hybrid membrane, which depressed the membrane performance.

Numerical simulation of transitions between back discharge regimes

International Nuclear Information System (INIS)

Jansky, Jaroslav; Lemont, Florent; Bessieres, Delphine; Paillol, Jean

2014-01-01

This paper presents numerical simulations of transitions between back discharge regimes. Back discharge refers to any discharge initiated at or near a dielectric layer covering a passive electrode. In this work, a pinhole in a dielectric layer on a plane anode serves as a model for back discharge activity. We have studied transitions between back discharge regimes by varying the surface charge density on the dielectric layer and the electric field in front of the pinhole. From the variation of these two independent parameters, the back discharge regimes have been depicted as a mode diagram inspired by the experimental study of Masuda and Mizuno. The resulting diagram includes the different discharge regimes that are commonly observed in experiments. The propagation of a positive ionizing wave inside the pinhole toward its edge, and the resulting formation of a plasma zone at its exit constitute the onset stage of back discharge. From this stage, the transitions to volume discharge or surface discharge can occur. The volume discharge regime consists of the propagation of a discharge in space toward the cathode which can be superimposed with the propagation of a discharge above the dielectric layer surface. The diagram reveals the conditions for transitions between back discharge regimes. (authors)

An intelligent hybrid system for surface coal mine safety analysis

Energy Technology Data Exchange (ETDEWEB)

Lilic, N.; Obradovic, I.; Cvjetic, A. [University of Belgrade, Belgrade (Serbia)

2010-06-15

Analysis of safety in surface coal mines represents a very complex process. Published studies on mine safety analysis are usually based on research related to accidents statistics and hazard identification with risk assessment within the mining industry. Discussion in this paper is focused on the application of AI methods in the analysis of safety in mining environment. Complexity of the subject matter requires a high level of expert knowledge and great experience. The solution was found in the creation of a hybrid system PROTECTOR, whose knowledge base represents a formalization of the expert knowledge in the mine safety field. The main goal of the system is the estimation of mining environment as one of the significant components of general safety state in a mine. This global goal is subdivided into a hierarchical structure of subgoals where each subgoal can be viewed as the estimation of a set of parameters (gas, dust, climate, noise, vibration, illumination, geotechnical hazard) which determine the general mine safety state and category of hazard in mining environment. Both the hybrid nature of the system and the possibilities it offers are illustrated through a case study using field data related to an existing Serbian surface coal mine.

Effect of different polishing systems on the surface roughness of nano-hybrid composites.

Science.gov (United States)

Patel, Brijesh; Chhabra, Naveen; Jain, Disha

2016-01-01

The study aimed to investigate the influence of different polishing systems on the surface roughness of nano-hybrid composite resins. Different shapes of polishing systems are available according to the site of work. To minimize variability, a new system with single shape is developed that can be utilized in both anterior as well as posterior teeth. Seventy composite discs were fabricated using Teflon well (10 mm × 3 mm). Two main group of nano-hybrid composite Group I - Filtek Z350 and Group II - Tetric N-Ceram were used (n = 35 for each group). Both groups were further divided into four subgroups. Subgroup a - OneGloss (n = 10), Subgroup b - PoGo (n = 10), Subgroup c - Sof-Lex spiral (n = 10), Subgroup d - Mylar strip (control, n = 5). Samples were polished according to the manufacturer's recommendations. Surface roughness test was performed using contact profilometer. The obtained data were analyzed using the one-way analysis of variance test. Tetric N-Ceram produced smoother surfaces than Filtek Z350 (P OneGloss" (P OneGloss" and "Sof-Lex Spiral."

Comparative Analysis of the Surface Ozone Regime Over Russia and Europe

Science.gov (United States)

Kuznetsov, G. I.; Tarasova, O. A.; Elansky, N. F.; Beloglazov, M. I.

2004-05-01

The data of the measurements of the surface ozone concentration (SOC) at several Russian cites, in TROICA expeditions, data of EMEP network as well as the results of LOTOS model application were used to compare the main characteristics of ozone spatial and temporal variability over Russia and Europe. To carry out this investigation the number of new methods of data analysis were developed and applied. Their complex application gave us possibility to separate clearly the contribution of photochemical processes having mainly periodical component (daily and seasonal). Hence more attention could be paid to the dynamical mechanism impacting SOC regime, their spatial and temporal variability including trends estimation. Spectral windowing application to the filtered database of EMEP network showed that among the different processes providing annual and shorter variability the main part (about 40% of dispersion) is governed by local and synoptical scale processes in the range of 2-7 days. At the same time the spatial distribution of these percentage contribution is non-uniform over Europe. One of the important mechanisms providing this type of variability as well as the longer ones is air transport. To study the impact of air transport the correlation fields were calculated for the transport indices using 2D NILU trajectories and SOC at EMEP network. They showed that at the Eastern border of Europe the growth of the westerlies provides not the decrease but the growth of observed SOC. This approach was use to study the features of the zonal and meridianal transport, its seasonal characteristics and annual variability. Moreover at Kislovodsk High Mountain Station the changes of the transport patters can partly explain even observed trend of SOC. Comparison of the regime at the different locations using TROICA data shows that in the most of Russian cities ozone destruction is observed. The generation of the surface ozone is only possible in the cases of combination of

Diffusion-controlled regime of surface-wave-produced plasmas in helium gas

International Nuclear Information System (INIS)

Berndt, J; Makasheva, K; Schlueter, H; Shivarova, A

2002-01-01

The study presents a numerical fluid-plasma model of diffusion-controlled surface-wave-sustained discharges in helium gas. The self-consistent behaviour of the discharge based on the interrelation between plasma density and Θ, the power absorbed on average by one electron, is described. The nonlinear process of step ionization in the charged particle balance equation is the main factor, which ensures the self-consistency. However, it is shown that in helium discharges, the ionization frequencies enter the dependence of Θ on the plasma density also through the ambipolar-diffusion coefficient. Results at two different values of the gas pressure and of the wave frequency are discussed. The lower value of the gas pressure is chosen according to the condition to have a pure diffusion-controlled regime without interference with a transition to the free-fall regime. The boundary condition for the ion flux at the wall sheath is used for determination of the value of μ, the quantity denoting the degree of the radial plasma-density inhomogeneity which, together with the electron-neutral elastic collision frequency, influences the wave propagation characteristics. The two values of the wave frequency chosen provide descriptions of high-frequency and microwave discharges. The model results in the self-consistent structure of the discharge: interrelated variations along the discharge length of wavenumber, space damping rate, Θ, plasma density and electron temperature. The power necessary for sustaining discharges of a given length is also calculated. Comparisons with argon discharges are shown

Detection of DNA hybridization using graphene-coated black phosphorus surface plasmon resonance sensor

Science.gov (United States)

Pal, Sarika; Verma, Alka; Raikwar, S.; Prajapati, Y. K.; Saini, J. P.

2018-05-01

In this paper, graphene-coated black phosphorus at the metal surface for the detection of DNA hybridization event is numerically demonstrated. The strategy consists of placing the sensing medium on top of black phosphorus-graphene-coated SPR which interfaces with phosphate-buffered saline solution carrying single-stranded DNA. Upon hybridization with its complementary DNA, desorption of the nanostructures takes place and thus enables the sensitive detection of the DNA hybridization event. The proposed sensor exhibits a sensitivity (125 ο/RIU), detection accuracy (0.95) and quality factor (13.62 RIU-1) for complementary DNA. In comparison with other reported papers, our suggested sensor provides much better performance. Thus, this label-free DNA detection platform should spur off new interest towards the use of black phosphorus-graphene-coated SPR interfaces.

Multi-machine transport analysis of hybrid discharges from the ITPA Profile Database

International Nuclear Information System (INIS)

Imbreaux, F.; Fujita, T.; Isayama, A.; Joffrin, E.; Kinsey, J.; Litaudon, X.; Luce, T.; Murakami, M.; Na, Y. S.; Sakamoto, Y.; Slips, A. C. C. C.; Wade, M.; Artaud, J. F.; Basiuk, V.

2005-01-01

The so-called Hybrid regime is a promising candidate scenario for ITER with a potential for longer inductive pulse at high fusion gain. Hybrid discharges are operated at higher q95 than the conventional H modes, which increases the non-inductive current fraction and the duration of the discharge. Another important characteristics of this regime is the absence of large sawteeth owing toa q-profile generally just above one in the plasma core. This property allows to reach high values of the normalised kinetic to magnetic pressure ratio β N =βaB T /I p of the order of 3, without triggering deleterious Neoclassical Tearing Modes. This work presents results of transport modelling of hybrid discharges from various tokamaks (Asdes Upgrade, DIII-D, JET, JT-60U) which have been submitted recently to the ITPA database. The objective is to assess the commonality of the transport physics in the hybrid regimes obtained by the various machines. The study focuses on the dependence of the transport properties as a function of important parameters like the density and the normalised Larmor radios ρ. Induced, those parameters play a critical role in the extrapolation of the transport characteristics of present day experiments to ITER. Various transport models are used in order to test their capability to reproduce the experimental parametric dependences on density and ρ. The extrapolability of the hybrid regime to ITER is checked using integrated modeling. (Author)

Hydrological regime shift in a constructed catchment: Effect of vegetation encroachment on surface runoff

Science.gov (United States)

Hinz, C.; Caviedes-Voullieme, D.; Andezhath Mohanan, A.; Brueck, Y.; Zaplata, M.

2017-12-01

The Hühnerwasser catchment (Chicken Creek) was constructed to provide discharge for a small stream in the post-mining landscape of Lusatia, Germany. It has an area of 6 ha and quaternary sands with a thickness of 2-4 m were dumped on to a clay liner to prevent deep drainage. After completion of the construction the catchment was left to develop on its own without intervention and has been monitored since 2005. The upper part of the catchment discharges water and sediment into the lower part forming an alluvial fan. Below the alluvial fan is a pond receiving all surface and subsurface water from the upper catchment. After the formation of the drainage network vegetation started growing and surface runoff decreased until the water balance was dominated by evapotranspiration. This regime shift and the rate at which it happened depends on the vegetation encroachment into the rills and the interrill areas. Based on the hypothesis that vegetation will increase surface roughness and infiltration behavior, aerial photos were used to map rills and vegetation within and outside the rills for the last 10 years to obtain a time series of change. Observational evidence clearly shows that vegetation encroaches from the bottom, from the interrill areas as well as from the top. The rills themselves did not change their topology, however, the width of the erosion rills and gully increased at the bottom. For a subcatchment area a high resolution a physical based numerical model of overland flow was developed to explicitly assess the importance of increasing roughness and infiltration capacity for surface runoff. For the purpose of analyzing the effect of rainfall variability a rainfall generator was developed to carry out large sets of simulations. The simulations provide a means to assess how the roughness/infiltration feedback affects the rate of regime shift for a set of parameters that are consistent with the observed hydrological behavior of the drainage network.

[Hybrid 3-D rendering of the thorax and surface-based virtual bronchoscopy in surgical and interventional therapy control].

Science.gov (United States)

Seemann, M D; Gebicke, K; Luboldt, W; Albes, J M; Vollmar, J; Schäfer, J F; Beinert, T; Englmeier, K H; Bitzer, M; Claussen, C D

2001-07-01

The aim of this study was to demonstrate the possibilities of a hybrid rendering method, the combination of a color-coded surface and volume rendering method, with the feasibility of performing surface-based virtual endoscopy with different representation models in the operative and interventional therapy control of the chest. In 6 consecutive patients with partial lung resection (n = 2) and lung transplantation (n = 4) a thin-section spiral computed tomography of the chest was performed. The tracheobronchial system and the introduced metallic stents were visualized using a color-coded surface rendering method. The remaining thoracic structures were visualized using a volume rendering method. For virtual bronchoscopy, the tracheobronchial system was visualized using a triangle surface model, a shaded-surface model and a transparent shaded-surface model. The hybrid 3D visualization uses the advantages of both the color-coded surface and volume rendering methods and facilitates a clear representation of the tracheobronchial system and the complex topographical relationship of morphological and pathological changes without loss of diagnostic information. Performing virtual bronchoscopy with the transparent shaded-surface model facilitates a reasonable to optimal, simultaneous visualization and assessment of the surface structure of the tracheobronchial system and the surrounding mediastinal structures and lesions. Hybrid rendering relieve the morphological assessment of anatomical and pathological changes without the need for time-consuming detailed analysis and presentation of source images. Performing virtual bronchoscopy with a transparent shaded-surface model offers a promising alternative to flexible fiberoptic bronchoscopy.

A Novel Hybrid Model for Drawing Trace Reconstruction from Multichannel Surface Electromyographic Activity.

Science.gov (United States)

Chen, Yumiao; Yang, Zhongliang

2017-01-01

Recently, several researchers have considered the problem of reconstruction of handwriting and other meaningful arm and hand movements from surface electromyography (sEMG). Although much progress has been made, several practical limitations may still affect the clinical applicability of sEMG-based techniques. In this paper, a novel three-step hybrid model of coordinate state transition, sEMG feature extraction and gene expression programming (GEP) prediction is proposed for reconstructing drawing traces of 12 basic one-stroke shapes from multichannel surface electromyography. Using a specially designed coordinate data acquisition system, we recorded the coordinate data of drawing traces collected in accordance with the time series while 7-channel EMG signals were recorded. As a widely-used time domain feature, Root Mean Square (RMS) was extracted with the analysis window. The preliminary reconstruction models can be established by GEP. Then, the original drawing traces can be approximated by a constructed prediction model. Applying the three-step hybrid model, we were able to convert seven channels of EMG activity recorded from the arm muscles into smooth reconstructions of drawing traces. The hybrid model can yield a mean accuracy of 74% in within-group design (one set of prediction models for all shapes) and 86% in between-group design (one separate set of prediction models for each shape), averaged for the reconstructed x and y coordinates. It can be concluded that it is feasible for the proposed three-step hybrid model to improve the reconstruction ability of drawing traces from sEMG.

The shortcomings of semi-local and hybrid functionals: what we can learn from surface science studies

International Nuclear Information System (INIS)

Stroppa, A; Kresse, G

2008-01-01

A study of the adsorption of CO on late 4d and 5d transition metal (111) surfaces (Ru, Rh, Pd, Ag, Os, Ir and Pt) considering atop and hollow site adsorption is presented. The applied functionals include the gradient-corrected Perdew-Burke-Ernzerhof (PBE) and Becke-Lee-Yang-Parr (BLYP) functionals, and the corresponding hybrid Hartree-Fock density functionals HSE and B3LYP. We find that PBE-based hybrid functionals (specifically HSE) yield, with the exception of Pt, the correct site order on all considered metals, but they also considerably overestimate the adsorption energies compared to experiment. On the other hand, the semi-local BLYP functional and the corresponding hybrid functional B3LYP yield very satisfactory adsorption energies and the correct adsorption site for all surfaces. We are thus faced with a Procrustean problem: the B3LYP and BLYP functionals seem to be the overall best choice for describing adsorption on metal surfaces, but they simultaneously fail to account well for the properties of the metal, vastly overestimating the equilibrium volume and underestimating the atomization energies. Setting out from these observations, general conclusions are drawn on the relative merits and drawbacks of various semi-local and hybrid functionals. The discussion includes a revised version of the PBE functional specifically optimized for bulk properties and surface energies (PBEsol), a revised version of the PBE functional specifically optimized to predict accurate adsorption energies (rPBE), as well as the aforementioned BLYP functional. We conclude that no semi-local functional is capable of describing all aspects properly, and including non-local exchange also only improves some but worsens other properties

Synthesis and characterization of hybrid micro/nano-structured NiTi surfaces by a combination of etching and anodizing

Science.gov (United States)

Huan, Z.; Fratila-Apachitei, L. E.; Apachitei, I.; Duszczyk, J.

2014-02-01

The purpose of this study was to generate hybrid micro/nano-structures on biomedical nickel-titanium alloy (NiTi). To achieve this, NiTi surfaces were firstly electrochemically etched and then anodized in fluoride-containing electrolyte. With the etching process, the NiTi surface was micro-roughened through the formation of micropits uniformly distributed over the entire surface. Following the subsequent anodizing process, self-organized nanotube structures enriched in TiO2 could be superimposed on the etched surface under specific conditions. Furthermore, the anodizing treatment significantly reduced water contact angles and increased the surface free energy compared to the surfaces prior to anodizing. The results of this study show for the first time that it is possible to create hybrid micro/nano-structures on biomedical NiTi alloys by combining electrochemical etching and anodizing under controlled conditions. These novel structures are expected to significantly enhance the surface biofunctionality of the material when compared to conventional implant devices with either micro- or nano-structured surfaces.

Synthesis and characterization of hybrid micro/nano-structured NiTi surfaces by a combination of etching and anodizing

International Nuclear Information System (INIS)

Huan, Z; Fratila-Apachitei, L E; Apachitei, I; Duszczyk, J

2014-01-01

The purpose of this study was to generate hybrid micro/nano-structures on biomedical nickel–titanium alloy (NiTi). To achieve this, NiTi surfaces were firstly electrochemically etched and then anodized in fluoride-containing electrolyte. With the etching process, the NiTi surface was micro-roughened through the formation of micropits uniformly distributed over the entire surface. Following the subsequent anodizing process, self-organized nanotube structures enriched in TiO 2 could be superimposed on the etched surface under specific conditions. Furthermore, the anodizing treatment significantly reduced water contact angles and increased the surface free energy compared to the surfaces prior to anodizing. The results of this study show for the first time that it is possible to create hybrid micro/nano-structures on biomedical NiTi alloys by combining electrochemical etching and anodizing under controlled conditions. These novel structures are expected to significantly enhance the surface biofunctionality of the material when compared to conventional implant devices with either micro- or nano-structured surfaces. (paper)

Synthesis and characterization of hybrid micro/nano-structured NiTi surfaces by a combination of etching and anodizing.

Science.gov (United States)

Huan, Z; Fratila-Apachitei, L E; Apachitei, I; Duszczyk, J

2014-02-07

The purpose of this study was to generate hybrid micro/nano-structures on biomedical nickel-titanium alloy (NiTi). To achieve this, NiTi surfaces were firstly electrochemically etched and then anodized in fluoride-containing electrolyte. With the etching process, the NiTi surface was micro-roughened through the formation of micropits uniformly distributed over the entire surface. Following the subsequent anodizing process, self-organized nanotube structures enriched in TiO2 could be superimposed on the etched surface under specific conditions. Furthermore, the anodizing treatment significantly reduced water contact angles and increased the surface free energy compared to the surfaces prior to anodizing. The results of this study show for the first time that it is possible to create hybrid micro/nano-structures on biomedical NiTi alloys by combining electrochemical etching and anodizing under controlled conditions. These novel structures are expected to significantly enhance the surface biofunctionality of the material when compared to conventional implant devices with either micro- or nano-structured surfaces.

Applying of the array transducers' technology for surface acoustic waves materials characterization in the transient regime; Application de la technologie multi-elements a la caracterisation des materiaux par ondes acoustiques de surface en regime impulsionnel

Energy Technology Data Exchange (ETDEWEB)

Frenet, D

2000-07-01

In this document we present a theoretical and experimental study which has been led to design a surface acoustic wave device for local characterisation (relatively to the wavelength) of isotropic or anisotropic materials. The device is based on a phased-array transducer of conical shape we have specifically designed for this purpose. It operates in the impulsive mode, in the frequency range of 1-5 MHz. In order to deduce mechanical properties of the material, it is possible to measure the surface wave characteristics (velocity, attenuation,...). Different methods for measuring the wave velocity have been developed taking advantage of from the phased-array technology. The originality of theses methods relies on the fact that the measures are performed without moving the transducer. Consequently, the device requires no additional mechanical system and it is quite compact. In addition, this shortens the characterisation process duration comparatively to the usually available methods (e. g. the V(z) technique). In the theoretical section of this study, a versatile model allowing to simulate in the time harmonic regime as well as in the transient regime, the transmitted field, the field reflected on isotropic or anisotropic planar samples and the output voltage for transducers of arbitrary shapes has been developed. The model has been applied to the phased-array conical transducer as well as to more classical transducers such as planar (rectangular) or focusing (spherically or cylindrically shaped) transducers. It predicts not only the geometrical contributions of the reflected field and signal but also the leaky contributions related to the surface acoustic waves. (author)

Hybrid quantum systems of ions and atoms

OpenAIRE

Sias, Carlo; Köhl, Michael

2014-01-01

In this chapter we review the progress in experiments with hybrid systems of trapped ions and ultracold neutral atoms. We give a theoretical overview over the atom-ion interactions in the cold regime and give a summary of the most important experimental results. We conclude with an overview of remaining open challenges and possible applications in hybrid quantum systems of ions and neutral atoms.

Regime switching model for financial data: Empirical risk analysis

Science.gov (United States)

Salhi, Khaled; Deaconu, Madalina; Lejay, Antoine; Champagnat, Nicolas; Navet, Nicolas

2016-11-01

This paper constructs a regime switching model for the univariate Value-at-Risk estimation. Extreme value theory (EVT) and hidden Markov models (HMM) are combined to estimate a hybrid model that takes volatility clustering into account. In the first stage, HMM is used to classify data in crisis and steady periods, while in the second stage, EVT is applied to the previously classified data to rub out the delay between regime switching and their detection. This new model is applied to prices of numerous stocks exchanged on NYSE Euronext Paris over the period 2001-2011. We focus on daily returns for which calibration has to be done on a small dataset. The relative performance of the regime switching model is benchmarked against other well-known modeling techniques, such as stable, power laws and GARCH models. The empirical results show that the regime switching model increases predictive performance of financial forecasting according to the number of violations and tail-loss tests. This suggests that the regime switching model is a robust forecasting variant of power laws model while remaining practical to implement the VaR measurement.

Towards the development of a hybrid-integrated chip interferometer for online surface profile measurements

International Nuclear Information System (INIS)

Kumar, P.; Martin, H.; Jiang, X.

2016-01-01

Non-destructive testing and online measurement of surface features are pressing demands in manufacturing. Thus optical techniques are gaining importance for characterization of complex engineering surfaces. Harnessing integrated optics for miniaturization of interferometry systems onto a silicon wafer and incorporating a compact optical probe would enable the development of a handheld sensor for embedded metrology applications. In this work, we present the progress in the development of a hybrid photonics based metrology sensor device for online surface profile measurements. The measurement principle along with test and measurement results of individual components has been presented. For non-contact measurement, a spectrally encoded lateral scanning probe based on the laser scanning microscopy has been developed to provide fast measurement with lateral resolution limited to the diffraction limit. The probe demonstrates a lateral resolution of ∼3.6 μm while high axial resolution (sub-nanometre) is inherently achieved by interferometry. Further the performance of the hybrid tuneable laser and the scanning probe was evaluated by measuring a standard step height sample of 100 nm.

Towards the development of a hybrid-integrated chip interferometer for online surface profile measurements

Energy Technology Data Exchange (ETDEWEB)

Kumar, P.; Martin, H.; Jiang, X. [EPSRC Centre for Innovative Manufacturing in Advanced Metrology, University of Huddersfield, Huddersfield HD1 3DH (United Kingdom)

2016-06-15

Non-destructive testing and online measurement of surface features are pressing demands in manufacturing. Thus optical techniques are gaining importance for characterization of complex engineering surfaces. Harnessing integrated optics for miniaturization of interferometry systems onto a silicon wafer and incorporating a compact optical probe would enable the development of a handheld sensor for embedded metrology applications. In this work, we present the progress in the development of a hybrid photonics based metrology sensor device for online surface profile measurements. The measurement principle along with test and measurement results of individual components has been presented. For non-contact measurement, a spectrally encoded lateral scanning probe based on the laser scanning microscopy has been developed to provide fast measurement with lateral resolution limited to the diffraction limit. The probe demonstrates a lateral resolution of ∼3.6 μm while high axial resolution (sub-nanometre) is inherently achieved by interferometry. Further the performance of the hybrid tuneable laser and the scanning probe was evaluated by measuring a standard step height sample of 100 nm.

Study on lower hybrid current drive efficiency at high density towards long-pulse regimes in Experimental Advanced Superconducting Tokamak

International Nuclear Information System (INIS)

Li, M. H.; Ding, B. J.; Zhang, J. Z.; Gan, K. F.; Wang, H. Q.; Zhang, L.; Wei, W.; Li, Y. C.; Wu, Z. G.; Ma, W. D.; Jia, H.; Chen, M.; Yang, Y.; Feng, J. Q.; Wang, M.; Xu, H. D.; Shan, J. F.; Liu, F. K.; Peysson, Y.

2014-01-01

Significant progress on both L- and H-mode long-pulse discharges has been made recently in Experimental Advanced Superconducting Tokamak (EAST) with lower hybrid current drive (LHCD) [J. Li et al., Nature Phys. 9, 817 (2013) And B. N. Wan et al., Nucl. Fusion 53, 104006 (2013).]. In this paper, LHCD experiments at high density in L-mode plasmas have been investigated in order to explore possible methods of improving current drive (CD) efficiency, thus to extend the operational space in long-pulse and high performance plasma regime. It is observed that the normalized bremsstrahlung emission falls much more steeply than 1/n e-av (line-averaged density) above n e-av  = 2.2 × 10 19  m −3 indicating anomalous loss of CD efficiency. A large broadening of the operating line frequency (f = 2.45 GHz), measured by a radio frequency (RF) probe located outside the EAST vacuum vessel, is generally observed during high density cases, which is found to be one of the physical mechanisms resulting in the unfavorable CD efficiency. Collisional absorption of lower hybrid wave in the scrape off layer (SOL) may be another cause, but this assertion needs more experimental evidence and numerical analysis. It is found that plasmas with strong lithiation can improve CD efficiency largely, which should be benefited from the changes of edge parameters. In addition, several possible methods are proposed to recover good efficiency in future experiments for EAST

Effect of stacking sequence and surface treatment on the thermal conductivity of multilayered hybrid nano-composites

Science.gov (United States)

Papanicolaou, G. C.; Pappa, E. J.; Portan, D. V.; Kotrotsos, A.; Kollia, E.

2018-02-01

The aim of the present investigation was to study the effect of both the stacking sequence and surface treatment on the thermal conductivity of multilayered hybrid nano-composites. Four types of multilayered hybrid nanocomposites were manufactured and tested: Nitinol- CNTs (carbon nanotubes)- Acrylic resin; Nitinol- Acrylic resin- CNTs; Surface treated Nitinol- CNTs- Acrylic resin and Surface treated Nitinol- Acrylic resin- CNTs. Surface treatment of Nitinol plies was realized by means of the electrochemical anodization. Surface topography of the anodized nitinol sheets was investigated through Scanning Electron Microscopy (SEM). It was found that the overall thermal response of the manufactured multilayered nano-composites was greatly influenced by both the anodization and the stacking sequence. A theoretical model for the prediction of the overall thermal conductivity has been developed considering the nature of the different layers, their stacking sequence as well as the interfacial thermal resistance. Thermal conductivity and Differential Scanning Calorimetry (DSC) measurements were conducted, to verify the predicted by the model overall thermal conductivities. In all cases, a good agreement between theoretical predictions and experimental results was found.

Layer-dependent surface potential of phosphorene and anisotropic/layer-dependent charge transfer in phosphorene-gold hybrid systems.

Science.gov (United States)

Xu, Renjing; Yang, Jiong; Zhu, Yi; Yan, Han; Pei, Jiajie; Myint, Ye Win; Zhang, Shuang; Lu, Yuerui

2016-01-07

The surface potential and the efficiency of interfacial charge transfer are extremely important for designing future semiconductor devices based on the emerging two-dimensional (2D) phosphorene. Here, we directly measured the strong layer-dependent surface potential of mono- and few-layered phosphorene on gold, which is consistent with the reported theoretical prediction. At the same time, we used an optical way photoluminescence (PL) spectroscopy to probe charge transfer in the phosphorene-gold hybrid system. We firstly observed highly anisotropic and layer-dependent PL quenching in the phosphorene-gold hybrid system, which is attributed to the highly anisotropic/layer-dependent interfacial charge transfer.

Aluminium vacuum vessel/first surface conceptual design for a commercial tokamak hybrid reactor

International Nuclear Information System (INIS)

Culbert, M.

1981-01-01

The purpose of this investigation was to develop a design concept for a commercial tokamak hybrid reactor (CTHR) vacuum vessel/first surface system which satisfies the engineering requirements for a commercial environment. An important distinction between the design constraints associated with 'pure' fusion and fusion-fission hybrid power reactors is that energy extraction from the first wall is not critical from the point of view of hybrid system economics. This allows the consideration of low temperature structural material for first wall application. The mechanical arrangement consists of a series of internally finned aluminium tube banks running poloidally around the torus. The coolant manifolds are at the top and bottom of the torus. The vessel is divided into sectors, the length of which depends on the spacing between TF coils. The tubes in each sector are welded to tube sheets which are in turn welded to semi-cylindrical manifolds which distribute the coolant uniformly to the tubes. The tubes, which are approx. equal to 2.5 cm in diameter at the manifold location, traverse the torus poloidal periphery and change from a circular cross section to a 2:1 elliptical cross section at the horizontal midplane. The arched tube is designed to be self-supporting between the manifold locations. The vacuum vessel's first surface will be plasma flamed sprayed aluminum applied to the tubular wall. (orig./GG)

Integration of Multiplexed Microfluidic Electrokinetic Concentrators with a Morpholino Microarray via Reversible Surface Bonding for Enhanced DNA Hybridization.

Science.gov (United States)

Martins, Diogo; Wei, Xi; Levicky, Rastislav; Song, Yong-Ak

2016-04-05

We describe a microfluidic concentration device to accelerate the surface hybridization reaction between DNA and morpholinos (MOs) for enhanced detection. The microfluidic concentrator comprises a single polydimethylsiloxane (PDMS) microchannel onto which an ion-selective layer of conductive polymer poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) ( PSS) was directly printed and then reversibly surface bonded onto a morpholino microarray for hybridization. Using this electrokinetic trapping concentrator, we could achieve a maximum concentration factor of ∼800 for DNA and a limit of detection of 10 nM within 15 min. In terms of the detection speed, it enabled faster hybridization by around 10-fold when compared to conventional diffusion-based hybridization. A significant advantage of our approach is that the fabrication of the microfluidic concentrator is completely decoupled from the microarray; by eliminating the need to deposit an ion-selective layer on the microarray surface prior to device integration, interfacing between both modules, the PDMS chip for electrokinetic concentration and the substrate for DNA sensing are easier and applicable to any microarray platform. Furthermore, this fabrication strategy facilitates a multiplexing of concentrators. We have demonstrated the proof-of-concept for multiplexing by building a device with 5 parallel concentrators connected to a single inlet/outlet and applying it to parallel concentration and hybridization. Such device yielded similar concentration and hybridization efficiency compared to that of a single-channel device without adding any complexity to the fabrication and setup. These results demonstrate that our concentrator concept can be applied to the development of a highly multiplexed concentrator-enhanced microarray detection system for either genetic analysis or other diagnostic assays.

Interactions of aqueous NOM with nanoscale TiO2: implications for ceramic membrane filtration-ozonation hybrid process.

Science.gov (United States)

Kim, Jeonghwan; Shan, Wenqian; Davies, Simon H R; Baumann, Melissa J; Masten, Susan J; Tarabara, Volodymyr V

2009-07-15

The combined effect of pH and calcium on the interactions of nonozonated and ozonated natural organic matter (NOM) with nanoscale TiO2 was investigated. The approach included characterization of TiO2 nanoparticles and NOM, extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) modeling of NOM-TiO2 and NOM-NOM interactions, batch study on the NOM adsorption onto TiO2 surface, and bench-scale study on the treatment of NOM-containing feed waters using a hybrid process that combines ozonation and ultrafiltration with a 5 kDa ceramic (TiO2 surface) membrane. It was demonstrated that depending on pH and TiO2 loading, the adsorption of NOM species is controlled by either the availability of divalent cations or by preozonation of NOM. XDLVO surface energy analysis predicts NOM adsorption onto TiO2 in the ozone-controlled regime but not in the calcium-controlled regime. In both regimes, short-range NOM-NOM and NOM-TiO2 interactions were governed by acid-base and van der Waals forces, whereas the role of electrostatic forces was relatively insignificant. Ozonation increased the surface energy of NOM, contributing to the hydrophilic repulsion component of the NOM-NOM and NOM-TiO2 interactions. In the calcium-controlled regime, neither NOM-TiO2 nor NOM-NOM interaction controlled adsorption. Non-XDLVO interactions such as intermolecular bridging by calcium were hypothesized to be responsible for the observed adsorption behavior. Adsorption data proved to be highly predictive of the permeate flux performance.

Light-matter interaction in the strong coupling regime: configurations, conditions, and applications.

Science.gov (United States)

Dovzhenko, D S; Ryabchuk, S V; Rakovich, Yu P; Nabiev, I R

2018-02-22

Resonance interaction between a molecular transition and a confined electromagnetic field can reach the coupling regime where coherent exchange of energy between light and matter becomes reversible. In this case, two new hybrid states separated in energy are formed instead of independent eigenstates, which is known as Rabi splitting. This modification of the energy spectra of the system offers new possibilities for controlled impact on various fundamental properties of coupled matter (such as the rate of chemical reactions and the conductivity of organic semiconductors). To date, the strong coupling regime has been demonstrated in many configurations under different ambient conditions. However, there is still no comprehensive approach to determining parameters for achieving the strong coupling regime for a wide range of practical applications. In this review, a detailed analysis of various systems and corresponding conditions for reaching strong coupling is carried out and their advantages and disadvantages, as well as the prospects for application, are considered. The review also summarizes recent experiments in which the strong coupling regime has led to new interesting results, such as the possibility of collective strong coupling between X-rays and matter excitation in a periodic array of Fe isotopes, which extends the applications of quantum optics; a strong amplification of the Raman scattering signal from a coupled system, which can be used in surface-enhanced and tip-enhanced Raman spectroscopy; and more efficient second-harmonic generation from the low polaritonic state, which is promising for nonlinear optics. The results reviewed demonstrate great potential for further practical applications of strong coupling in the fields of photonics (low-threshold lasers), quantum communications (switches), and biophysics (molecular fingerprinting).

Applying of the array transducers' technology for surface acoustic waves materials characterization in the transient regime

International Nuclear Information System (INIS)

Frenet, D.

2000-01-01

In this document we present a theoretical and experimental study which has been led to design a surface acoustic wave device for local characterisation (relatively to the wavelength) of isotropic or anisotropic materials. The device is based on a phased-array transducer of conical shape we have specifically designed for this purpose. It operates in the impulsive mode, in the frequency range of 1-5 MHz. In order to deduce mechanical properties of the material, it is possible to measure the surface wave characteristics (velocity, attenuation,...). Different methods for measuring the wave velocity have been developed taking advantage of from the phased-array technology. The originality of theses methods relies on the fact that the measures are performed without moving the transducer. Consequently, the device requires no additional mechanical system and it is quite compact. In addition, this shortens the characterisation process duration comparatively to the usually available methods (e. g. the V(z) technique). In the theoretical section of this study, a versatile model allowing to simulate in the time harmonic regime as well as in the transient regime, the transmitted field, the field reflected on isotropic or anisotropic planar samples and the output voltage for transducers of arbitrary shapes has been developed. The model has been applied to the phased-array conical transducer as well as to more classical transducers such as planar (rectangular) or focusing (spherically or cylindrically shaped) transducers. It predicts not only the geometrical contributions of the reflected field and signal but also the leaky contributions related to the surface acoustic waves. (author)

The effects of surface roughness on the scattering properties of hexagonal columns with sizes from the Rayleigh to the geometric optics regimes

International Nuclear Information System (INIS)

Liu, Chao; Lee Panetta, R.; Yang, Ping

2013-01-01

Effects of surface roughness on the optical scattering properties of ice crystals are investigated using a random wave superposition model of roughness that is a simplification of models used in studies of scattering by surface water waves. Unlike previous work with models of rough surfaces applicable only in limited size ranges, such as surface perturbation methods in the small particle regime or the tilted-facet (TF) method in the large particle regime, ours uses a single roughness model to cover a range in sizes extending from the Rayleigh to the geometric optics regimes. The basic crystal shape we examine is the hexagonal column but our roughening model can be used for a wide variety of particle geometries. To compute scattering properties over the range of sizes we use the pseudo-spectral time domain method (PSTD) for small to moderate sized particles and the improved geometric optics method (IGOM) for large ones. Use of the PSTD with our roughness model is straightforward. By discretizing the roughened surface with triangular sub-elements, we adapt the IGOM to give full consideration of shadow effects, multiple reflections/refractions at the surface, and possible reentrance of the scattered beams. We measure the degree of roughness of a surface by the variance (σ 2 ) of surface slopes occurring on the surfaces. For moderately roughened surfaces (σ 2 ≤0.1) in the large particle regime, the scattering properties given by the TF and IGOM agree well, but differences in results obtained with the two methods become noticeable as the surface becomes increasingly roughened. Having a definite, albeit idealized, roughness model we are able to use the combination of the PSTD and IGOM to examine how a fixed degree of surface roughness affects the scattering properties of a particle as the size parameter of the particle changes. We find that for moderately rough surfaces in our model, as particle size parameter increases beyond about 20 the influence of surface

Extending the collisional fluid equations into the long mean-free-path regime in toroidal plasmas. IV. Banana regime

International Nuclear Information System (INIS)

Shaing, K. C.

2007-01-01

In Part I [Phys. Fluids B 2, 1190 (1990)] and Part II [Phys. Plasmas 12, 082508 (2005)], it was emphasized that the equilibrium plasma viscous forces when applied for the magnetohydrodynamic (MHD) modes are only rigorously valid at the mode rational surface where m-nq=0. Here, m is the poloidal mode number, n is the toroidal mode number, and q is the safety factor. This important fact has been demonstrated explicitly by calculating the viscous forces in the plateau regime in Parts I and II. Here, the effective viscous forces in the banana regime are calculated for MHD modes by solving the linear drift kinetic equation that is driven by the plasma flows first derived in Part I. At the mode rational surface, the equilibrium plasma viscous forces are reproduced. However, it is found that away from the mode rational surface, the viscous forces for MHD modes decrease, a behavior similar to that observed in the viscous forces for the plateau regime. The proper form of the momentum equation that is appropriate for the modeling of the MHD modes is also discussed

The effect of the shape of single, sub-ms voltage pulses on the rates of surface immobilization and hybridization of DNA

International Nuclear Information System (INIS)

Cabeca, R; Rodrigues, M; Chu, V; Conde, J P; Prazeres, D M F

2009-01-01

Electric fields generated by single square and sinusoidal voltage pulses with amplitudes below 2 V were used to assist the covalent immobilization of single-stranded, thiolated DNA probes, onto a chemically functionalized SiO 2 surface and to assist the specific hybridization of single-stranded DNA targets with immobilized complementary probes. The single-stranded immobilized DNA probes were either covalently immobilized (chemisorption) or electrostatically adsorbed (physisorption) to a chemically functionalized surface. Comparing the speed of electric field assisted immobilization and hybridization with the corresponding control reactions (without electric field), an increase of several orders of magnitude is observed, with the reaction timescaled down from 1 to 2 h to a range between 100 ns and 1 ms. The influence of the shape of the voltage pulse (square versus sinusoidal) and its duration were studied for both immobilization and hybridization reactions. The results show that pulsed electric fields are a useful tool to achieve temporal and spatial control of surface immobilization and hybridization reactions of DNA.

Diversiform hybrid-polarization surface plasmon polaritons in a dielectric–metal metamaterial

Directory of Open Access Journals (Sweden)

Q. Zhang

2017-04-01

Full Text Available Hybrid-polarization surface plasmon polaritons (HSPPs at the interface between an isotropic medium and a one-dimensional metal–dielectric metamaterial (MM were discussed, where the metal-layer permittivity was described with the improved Drude model. From the obtained dispersion equations, we predicated five types of HSPPs. One type is the Dyakonov-like surface polariton and another type is the tradition-like surface polarton. The others are new types of HSPPs. We establish a numerical simulation method of the attenuated total reflection (ATR measurement to examine these HSPPs. The results from the ATR spectra are consistent with those from the dispersion equations and indicate the different polarization features of these HSPPs. The numerical results also demonstrate that the observation of each type of HSPPs requires different conditions dictated by the material parameters and the polarization direction of incident light used in the ATR spectra. These results may further widen the space of potential applications of surface plasmon polaritons.

General concept of a gas engine for a hybrid vehicle, operating on methanol dissociation products

International Nuclear Information System (INIS)

Tartakovsky, L.; Aleinikov, Y.; Fainberg, V.; Garbar, A.; Gutman, M.; Hetsroni, G.; Schindler, Y.; Zvirin, Y.

1998-01-01

The paper presents a general concept of a hybrid propulsion system, based on an SI internal combustion engine fueled by methanol dissociation products (MDP). The proposed hybrid propulsion scheme is a series hybrid, which allows the engine to be operated in an on-off mode at constant optimal regime. The engine is fed by gaseous products of methanol dissociation (mainly hydrogen and carbon monoxide) emerging from an on-board catalytic reformer. The general scheme and base operation features of the propulsion system are described. The benefits that may be achieved by combining the well-known idea of on-board methanol dissociation with the hybrid vehicle concept are discussed. The proposed scheme is compared with those of systems operating on gasoline, liquid methanol, hydrogen and also with the multi-regime (not hybrid) engine fed by MDP

Surface-enhanced localized surface plasmon resonance biosensing of avian influenza DNA hybridization using subwavelength metallic nanoarrays

Energy Technology Data Exchange (ETDEWEB)

Kim, Shin Ae; Jang, Sung Min; Kim, Sung June [School of Electrical Engineering and Computer Science, Seoul National University, Seoul 151-742 (Korea, Republic of); Byun, Kyung Min [Department of Biomedical Engineering, Kyung Hee University, Yongin 446-701 (Korea, Republic of); Kim, Kyujung; Kim, Donghyun [Program of Nanomedical Science and Technology, Yonsei University, Seoul 120-749 (Korea, Republic of); Ma, Kyungjae; Oh, Youngjin [School of Electrical and Electronic Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of); Kim, Sung Guk [College of Veterinary Medicine, Cornell University, Ithaca, New York 14853 (United States); Shuler, Michael L, E-mail: kmbyun@khu.ac.kr [Department of Biomedical Engineering, Cornell University, Ithaca, New York 14853 (United States)

2010-09-03

We demonstrated enhanced localized surface plasmon resonance (SPR) biosensing based on subwavelength gold nanoarrays built on a thin gold film. Arrays of nanogratings (1D) and nanoholes (2D) with a period of 200 nm were fabricated by electron-beam lithography and used for the detection of avian influenza DNA hybridization. Experimental results showed that both nanoarrays provided significant sensitivity improvement and, especially, 1D nanogratings exhibited higher SPR signal amplification compared with 2D nanohole arrays. The sensitivity enhancement is associated with changes in surface-limited reaction area and strong interactions between bound molecules and localized plasmon fields. Our approach is expected to improve both the sensitivity and sensing resolution and can be applicable to label-free detection of DNA without amplification by polymerase chain reaction.

Diagnosis of Lower Hybrid on MST

International Nuclear Information System (INIS)

Burke, D. R.; Goetz, J. A.; Kaufman, M. C.; Almagri, A. F.; Anderson, J. K.; Forest, C. B.; Prager, S. C.

2007-01-01

RF driven current has never been demonstrated in a Reversed Field Pinch. Recently the lower hybrid system on the Madison Symmetric Torus reached a new operating regime. This upgrade allows RF powers of up to 5% of the Ohmic input power to be injected. It is therefore anticipated that the lower hybrid system is on the threshold of producing meaningful changes to the RFP equilibrium. A diagnostic set is under development to facilitate the study of such changes and lay the foundation for near megawatt operations. Many measurements are being studied for viability. These include electron cyclotron emission, examinations of bulk ion and electron heating, surface perturbation pickup coils, magnetic probe measurements, and Langmuir probe measurements. In addition, several x-ray diagnostics are in operation: pulse height analysis is performed on detector arrays to determine the 5-200 keV spectrum. An insertable target probe is available to create x-rays from fast electrons. Tomographic inversion of 2-D Soft x-ray detectors yields equilibrium information through island structure. Results from experiments with source power up to 225 kW will be presented. Preliminary results from CQL3D Fokker-Planck simulations will also be presented

Silver nanoparticles containing hybrid polymer microgels with tunable surface plasmon resonance and catalytic activity

Energy Technology Data Exchange (ETDEWEB)

Ajmal, Muhammad; Siddiq, Mohammad [Quaid-I-Azam University, Islamabad (Pakistan); Farooqi, Zahoor Hussain [University of the Punjab, Lahore (Pakistan)

2013-11-15

Multi-responsive poly(N-isopropylacrylamide-methacrylic acid-acrylamide) [P(NIPAM-MAA-AAm)] copolymer microgel was prepared by free radical emulsion polymerization. Silver nanoparticles were fabricated inside the microgel network by in-situ reduction of silver nitrate. Swelling and deswelling behavior of the pure microgels was studied under various conditions of pH and temperature using dynamic light scattering. A red shift was observed in surface plasmon resonance wavelength of Ag nanoparticles with pH induced swelling of hybrid microgel. The catalytic activity of the hybrid system was investigated by monitoring the reduction of p-nitrophenol under different conditions of temperature and amount of catalysts. For this catalytic reaction a time delay of 8 to 10min was observed at room temperature, which was reduced to 2 min at high temperature due to swelling of microgels, which facilitated diffusion of reactants to catalyst surface and increased rate of reaction.

Surface decoration with MnO{sub 2} nanoplatelets on graphene/TiO{sub 2} (B) hybrids for rechargeable lithium-ion batteries

Energy Technology Data Exchange (ETDEWEB)

Li, Xinlu, E-mail: lixinlu@cqu.edu.cn; Zhang, Yonglai; Zhong, Qineng; Li, Tongtao; Li, Hongyi; Huang, Jiamu

2014-09-15

Graphical abstract: - Highlights: • The surface of graphene/TiO{sub 2} (B) hybrids is decorated by ultrathin MnO{sub 2} nanoplatelets. • MnO{sub 2}@graphene/TiO{sub 2} (B) composites exhibit high specific surface area of 283.9 m{sup 2} g{sup −1}. • The reversible capacity of graphene/TiO{sub 2} (B) hybrids is greatly improved by surface decoration with low content of MnO{sub 2}. - Abstract: Hierarchically ultrathin MnO{sub 2} nanoplatelets are decorated on the surface of graphene-based TiO{sub 2} (B) hybrids by a facile water-bath reaction to fabricate MnO{sub 2}@graphene/TiO{sub 2} (B) composites. The multi-component composites show high specific surface area of 283.9 m{sup 2} g{sup −1}, facilitating the electrochemical reactions with solvented lithium ions in the enlarged interface area. The reversible capacity of the composites remains 243 mA h g{sup −1} after 150 cycles, with capacity retention of 83.5%. In comparison with graphene/TiO{sub 2} (B) hybrids, the MnO{sub 2}@graphene/TiO{sub 2} (B) composites perform better rate capability, suggesting that surface decoration with MnO{sub 2} nanoplatelets can be a promising strategy to enhance the electrochemical performance of anode materials for lithium ion batteries.

Spin-orbit torque in 3D topological insulator-ferromagnet heterostructure: crossover between bulk and surface transport

KAUST Repository

Ghosh, Sumit; Manchon, Aurelien

2017-01-01

Current-driven spin-orbit torques are investigated in a heterostructure composed of a ferromagnet deposited on top of a three dimensional topological insulator using the linear response formalism. We develop a tight-binding model of the heterostructure adopting a minimal interfacial hybridization scheme that promotes induced magnetic exchange on the topological surface states, as well as induced Rashba-like spin-orbit coupling in the ferromagnet. Therefore, our model accounts for spin Hall effect from bulk states together with inverse spin galvanic and magnetoelectric effects at the interface on equal footing. By varying the transport energy across the band structure, we uncover a crossover from surface-dominated to bulk-dominated transport regimes. We show that the spin density profile and the nature of the spin-orbit torques differ substantially in both regimes. Our results, which compare favorably with experimental observations, demonstrate that the large damping torque reported recently is more likely attributed to interfacial magnetoelectric effect, while spin Hall torque remains small even in the bulk-dominated regime.

Spin-orbit torque in 3D topological insulator-ferromagnet heterostructure: crossover between bulk and surface transport

KAUST Repository

Ghosh, Sumit

2017-11-29

Current-driven spin-orbit torques are investigated in a heterostructure composed of a ferromagnet deposited on top of a three dimensional topological insulator using the linear response formalism. We develop a tight-binding model of the heterostructure adopting a minimal interfacial hybridization scheme that promotes induced magnetic exchange on the topological surface states, as well as induced Rashba-like spin-orbit coupling in the ferromagnet. Therefore, our model accounts for spin Hall effect from bulk states together with inverse spin galvanic and magnetoelectric effects at the interface on equal footing. By varying the transport energy across the band structure, we uncover a crossover from surface-dominated to bulk-dominated transport regimes. We show that the spin density profile and the nature of the spin-orbit torques differ substantially in both regimes. Our results, which compare favorably with experimental observations, demonstrate that the large damping torque reported recently is more likely attributed to interfacial magnetoelectric effect, while spin Hall torque remains small even in the bulk-dominated regime.

Heavy quarkonium hybrids: Spectrum, decay, and mixing

Science.gov (United States)

Oncala, Ruben; Soto, Joan

2017-07-01

We present a largely model-independent analysis of the lighter heavy quarkonium hybrids based on the strong coupling regime of potential nonrelativistic QCD. We calculate the spectrum at leading order, including the mixing of static hybrid states. We use potentials that fulfill the required short and long distance theoretical constraints and fit well the available lattice data. We argue that the decay width to the lower lying heavy quarkonia can be reliably estimated in some cases and provide results for a selected set of decays. We also consider the mixing with heavy quarkonium states. We establish the form of the mixing potential at O (1 /mQ) , mQ being the mass of the heavy quarks, and work out its short and long distance constraints. The weak coupling regime of potential nonrelativistic QCD and the effective string theory of QCD are used for that goal. We show that the mixing effects may indeed be important and produce large spin symmetry violations. Most of the isospin zero XYZ states fit well in our spectrum, either as a hybrid or standard quarkonium candidate.

Spin-Polarized Hybridization at the interface between different 8-hydroxyquinolates and the Cr(001) surface

Science.gov (United States)

Wang, Jingying; Deloach, Andrew; Dougherty, Daniel B.; Dougherty Lab Team

Organic materials attract a lot of attention due to their promising applications in spintronic devices. It is realized that spin-polarized metal/organic interfacial hybridization plays an important role to improve efficiency of organic spintronic devices. Hybridized interfacial states help to increase spin injection at the interface. Here we report spin-resolved STM measurements of single tris(8-hydroxyquinolinato) aluminum molecules adsorbed on the antiferromagnetic Cr(001). Our observations show a spin-polarized interface state between Alq3 and Cr(001). Tris(8-hydroxyquinolinato) chromium has also been studied and compared with Alq3, which exhibits different spin-polarized hybridization with the Cr(001) surface state than Alq3. We attribute the differences to different character of molecular orbitals in the two different quinolates.

Realizing high-performance metamaterial absorber based on the localized surface plasmon resonance in the terahertz regime

Science.gov (United States)

Yunfeng, Lin; Xiaoqi, Hu; Lin, Hu

2018-04-01

A composite structure design metamaterial absorber is designed and simulated. The proposed composite structure consists of a double-hole sub-structure and a double-metallic particle sub-structure. The damping constant of bulk gold layer is optimized to eliminate the adverse effects of the grain boundary and the surface scattering of thin films on the absorption property. Two absorption peaks (A1 = 58%, A2 = 23%) are achieved based on the localized surface plasmon (LSP) modes resonance. Moreover, the plasmonic hybridization phenomenon between LSP modes is found, which leads to the absorption enhancement between two absorption peaks. The proposed metamaterial absorber holds the property of wide-angle incidence.

Evaluation of Calendar Year 1996 groundwater and surface water quality data for the Bear Creek Hydrogeologic Regime at the US Department of Energy Y-12 Plant, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

1997-08-01

This report presents an evaluation of the groundwater monitoring data obtained in the Bear Creek Hydrogeologic Regime (Bear Creek Regime) during calendar year (CY) 1996. The monitoring data were collected for the multiple programmatic purposes of the Y-12 Plant Groundwater Protection Program (GWPP) and have been reported in Calendar Year 1996 Annual Groundwater Monitoring Report for the Bear Creek Hydrogeologic Regime at the US Department of Energy Y-12 Plant, Oak Ridge, Tennessee. The Annual Monitoring report presents only the results of the monitoring data evaluations required for waste management sites addressed under the Resource Conservation and Recovery Act (RCRA) post-closure permit for the Bear Creek Regime. The Annual Monitoring Report also serves as a consolidated reference for the groundwater and surface water monitoring data obtained throughout the Bear Creek Regime under the auspices of the Y-12 GWPP. This report provides an evaluation of the CY 1996 monitoring data with an emphasis on regime-wide groundwater and surface water quality and long-term concentration trends of regulated and non-regulated monitoring parameters

Evaluation of Calendar Year 1996 groundwater and surface water quality data for the Bear Creek Hydrogeologic Regime at the US Department of Energy Y-12 Plant, Oak Ridge, Tennessee

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-08-01

This report presents an evaluation of the groundwater monitoring data obtained in the Bear Creek Hydrogeologic Regime (Bear Creek Regime) during calendar year (CY) 1996. The monitoring data were collected for the multiple programmatic purposes of the Y-12 Plant Groundwater Protection Program (GWPP) and have been reported in Calendar Year 1996 Annual Groundwater Monitoring Report for the Bear Creek Hydrogeologic Regime at the US Department of Energy Y-12 Plant, Oak Ridge, Tennessee. The Annual Monitoring report presents only the results of the monitoring data evaluations required for waste management sites addressed under the Resource Conservation and Recovery Act (RCRA) post-closure permit for the Bear Creek Regime. The Annual Monitoring Report also serves as a consolidated reference for the groundwater and surface water monitoring data obtained throughout the Bear Creek Regime under the auspices of the Y-12 GWPP. This report provides an evaluation of the CY 1996 monitoring data with an emphasis on regime-wide groundwater and surface water quality and long-term concentration trends of regulated and non-regulated monitoring parameters.

Simulation and Analysis of the Hybrid Operating Mode in ITER

International Nuclear Information System (INIS)

Kessel, C.E.; Budny, R.V.; Indireshkumar, K.

2005-01-01

The hybrid operating mode in ITER is examined with 0D systems analysis, 1.5D discharge scenario simulations using TSC and TRANSP, and the ideal MHD stability is discussed. The hybrid mode has the potential to provide very long pulses and significant neutron fluence if the physics regime can be produced in ITER. This paper reports progress in establishing the physics basis and engineering limitation for the hybrid mode in ITER

Near-wall effects in improved plasma confinement regimes in tokamak FT-2

International Nuclear Information System (INIS)

Budnikov, V.N.; D'yachenko, V.V.; Esipov, L.A.

1997-01-01

Transition to the regime of improved plasma confinement (H-mode) revealed in experiments on low hybrid heating in tokamak ft-2 is analyzed. Main attention is paid to processes, taking place in near-wall region. The data are correlated with results of experiments in large tokamaks

A Case Study of a Hybrid Parallel 3D Surface Rendering Graphics Architecture

DEFF Research Database (Denmark)

Holten-Lund, Hans Erik; Madsen, Jan; Pedersen, Steen

1997-01-01

This paper presents a case study in the design strategy used inbuilding a graphics computer, for drawing very complex 3Dgeometric surfaces. The goal is to build a PC based computer systemcapable of handling surfaces built from about 2 million triangles, andto be able to render a perspective view...... of these on a computer displayat interactive frame rates, i.e. processing around 50 milliontriangles per second. The paper presents a hardware/softwarearchitecture called HPGA (Hybrid Parallel Graphics Architecture) whichis likely to be able to carry out this task. The case study focuses ontechniques to increase...

How to optimize ultrashort pulse laser interaction with glass surfaces in cutting regimes?

Energy Technology Data Exchange (ETDEWEB)

Bulgakova, Nadezhda M., E-mail: bulgakova@fzu.cz [HiLASE Centre, Institute of Physics ASCR, Za Radnicí 828, 25241 Dolní Břežany (Czech Republic); Institute of Thermophysics SB RAS, 1 Lavrentyev Ave., Novosibirsk 630090 (Russian Federation); Zhukov, Vladimir P. [Institute of Computational Technologies SB RAS, 6 Lavrentyev Ave., 630090 Novosibirsk (Russian Federation); Novosibirsk State Technical University, 20 Karl Marx Ave., 630073 Novosibirsk (Russian Federation); Collins, Adam R. [NCLA, NUI Galway, Galway (Ireland); Rostohar, Danijela; Derrien, Thibault J.-Y.; Mocek, Tomáš [HiLASE Centre, Institute of Physics ASCR, Za Radnicí 828, 25241 Dolní Břežany (Czech Republic)

2015-05-01

Highlights: • The factors influencing laser micromachining of transparent materials are analyzed. • Important role of ambient gas in laser processing is shown by numerical simulations. • The large potential of bi-wavelength laser processing is demonstrated. - Abstract: The interaction of short and ultrashort pulse laser radiation with glass materials is addressed. Particular attention is paid to regimes which are important in industrial applications such as laser cutting, drilling, functionalization of material surfaces, etc. Different factors influencing the ablation efficiency and quality are summarized and their importance is illustrated experimentally. The effects of ambient gas ionization in front of the irradiated target are also analyzed. A possibility to enhance laser coupling with transparent solids by bi-wavelength irradiation is discussed.

A statistical-dynamical scheme for reconstructing ocean forcing in the Atlantic. Part I: weather regimes as predictors for ocean surface variables

Energy Technology Data Exchange (ETDEWEB)

Cassou, Christophe; Minvielle, Marie; Terray, Laurent [CERFACS/CNRS, Climate Modelling and Global Change Team, Toulouse (France); Perigaud, Claire [JPL-NASA, Ocean Science Element, Pasadena, CA (United States)

2011-01-15

The links between the observed variability of the surface ocean variables estimated from reanalysis and the overlying atmosphere decomposed in classes of large-scale atmospheric circulation via clustering are investigated over the Atlantic from 1958 to 2002. Daily 500 hPa geopotential height and 1,000 hPa wind anomaly maps are classified following a weather-typing approach to describe the North Atlantic and tropical Atlantic atmospheric dynamics, respectively. The algorithm yields patterns that correspond in the extratropics to the well-known North Atlantic-Europe weather regimes (NAE-WR) accounting for the barotropic dynamics, and in the tropics to wind classes (T-WC) representing the alteration of the trades. 10-m wind and 2-m temperature (T2) anomaly composites derived from regime/wind class occurrence are indicative of strong relationships between daily large-scale atmospheric circulation and ocean surface over the entire Atlantic basin. High temporal correlation values are obtained basin-wide at low frequency between the observed fields and their reconstruction by multiple linear regressions with the frequencies of occurrence of both NAE-WR and T-WC used as sole predictors. Additional multiple linear regressions also emphasize the importance of accounting for the strength of the daily anomalous atmospheric circulation estimated by the combined distances to all regimes centroids in order to reproduce the daily to interannual variability of the Atlantic ocean. We show that for most of the North Atlantic basin the occurrence of NAE-WR generally sets the sign of the ocean surface anomaly for a given day, and that the inter-regime distances are valuable predictors for the magnitude of that anomaly. Finally, we provide evidence that a large fraction of the low-frequency trends in the Atlantic observed at the surface over the last 50 years can be traced back, except for T2, to changes in occurrence of tropical and extratropical weather classes. All together, our

Modern fire regime resembles historical fire regime in a ponderosa pine forest on Native American land

Science.gov (United States)

Amanda B. Stan; Peter Z. Fule; Kathryn B. Ireland; Jamie S. Sanderlin

2014-01-01

Forests on tribal lands in the western United States have seen the return of low-intensity surface fires for several decades longer than forests on non-tribal lands. We examined the surface fire regime in a ponderosa pinedominated (Pinus ponderosa) forest on the Hualapai tribal lands in the south-western United States. Using fire-scarred trees, we inferred temporal (...

TYPES OF POLITICAL REGIMES IN THE IRKUTSK REGION

Directory of Open Access Journals (Sweden)

И В Орлова

2017-12-01

Full Text Available The authors consider contemporary western and Russian classifications of regional political regimes and their applicability for Russia. Based on the analysis of political theories, the authors chose the traditional typology of regional political regimes focusing on the minimalist interpretation of democracy (electoral competition and methods for identifying regional scenarios introduced by V.Ya. Gelman. The authors study the case of the Irkutsk Region as a region with conflicting elites, in which in a short period several regional heads were replaced. Based on the contemporary political history, the authors analyze the regional political regime using the following criteria: democracy/autocracy, consolidation/oligo-poly, compromise/conflict relations within the ruling elite. The results of the analysis prove the existence of checks and balances in the political system of the Irkutsk Region. Such a system restrains strong politicians attempts to monopolize the political power in the region. When any political player gains too much influence, other centers of power unite against him and together return the situation to the status quo. The political regime of the Irkutsk Region ensures a relatively high level of political competition, at the same time it is a part of the uncompetitive political regime of the Russian Federation, therefore it is a ‘hybrid democracy’. The authors’ analysis of intra-elite relations in the region revealed a high predisposition to conflicts with the dominant scenario of ‘war of all against all’.

The modification of nanocomposite hybrid polymer surfaces by exposure to oxygen containing plasmas

Science.gov (United States)

Figueiredo, Ashley; Zimmermann, Katherine; Augustine, Brian; Hughes, Chris; Chusuei, Charles

2006-11-01

The wetting properties of the surfaces of the nanocomposite hybrid polymer poly[(propylmethacryl-heptaisobutyl- polyhedral oligomeric silsequioxane)-co-(methylmethacrylate)] (POSS-PMMA)has been studied before and after exposure to plasmas containing oxygen. The contact angle of water droplets on the surface showed a substantial decrease after plasma exposure indicating an increase in the hydrophilicity of the surface. A model was developed in which the plasma preferentially removed organic material including both the PMMA backbone and isobutyl groups from the corners of the POSS cages leaving behind a surface characterized by the silicon oxide-like POSS material. Measurements of surface concentrations of oxygen, silicon, and carbon by x-ray photoelectron spectroscopy (XPS) showed an increase in the amount of oxygen and silicon compared to carbon and the appropriate chemical shifts were observed in the XPS data to support the model of Si-O enrichment on the surface. Variable angle spectroscopic ellipsometry (VASE) and atomic force microscopy (AFM) measurements also supported the model and these results will be presented.

Hard electroproduction of hybrid mesons

International Nuclear Information System (INIS)

Anikin, I.V.; LPT Universite Paris-Sud, Orsay; Szymanowski, L.; Teryaev, O.V.; ); Wallon, S.

2005-01-01

We estimate the sizeable cross section for deep exclusive electroproduction of an exotic J PC = 1 -+ hybrid meson in the Bjorken regime. The production amplitude scales like the one for usual meson electroproduction, i.e. as 1/Q 2 . This is due to the non-vanishing leading twist distribution amplitude for the hybrid meson, which may be normalized thanks to its relation to the energy momentum tensor and to the QCD sum rules technique. The hard amplitude is considered up to next-to-leading order in as and we explore the consequences of fixing the renormalization scale ambiguity through the BLM procedure. (author)

Exotic hybrid mesons in hard electroproduction

CERN Document Server

Anikin, I V; Szymanowski, L; Teryaev, O V; Wallon, S

2005-01-01

We estimate the sizeable cross section for deep exclusive electroproduction of an exotic $J^{PC}=1^{-+}$ hybrid meson in the Bjorken regime. The production amplitude scales like the one for usual meson electroproduction, i.e. as $1/Q^2$. This is due to the non-vanishing leading twist distribution amplitude for the hybrid meson, which may be normalized thanks to its relation to the energy momentum tensor and to the QCD sum rules technique. The hard amplitude is considered up to next-to-leading order in $\\alpha_{S}$ and we explore the consequences of fixing the renormalization scale ambiguity through the BLM procedure. We study the particular case where the hybrid meson decays through a $\\pi\\eta $ meson pair. We discuss the $\\pi\\eta$ generalized distribution amplitude and then calculate the production amplitude for this process. We propose a forward-backward asymmetry in the production of $\\pi$ and $\\eta$ mesons as a signal for the hybrid meson production. We briefly comment on hybrid electroproduction at very ...

Evaluation of Calendar Year 1996 groundwater and surface water quality data for the Upper East Fork Poplar Creek Hydrogeologic Regime at the US Department of Energy Y-12 Plant, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

1997-09-01

This report presents an evaluation of the groundwater monitoring data obtained in the Upper East Fork Poplar Creek Hydrogeologic Regime (East Fork Regime) during calendar year (CY) 1996. The East Fork Regime encompasses several confirmed and suspected sources of groundwater contamination within industrialized areas of the US Department of Energy (DOE) Y-12 Plant in Bear Creek Valley (BCV) southeast of Oak Ridge, Tennessee. The CY 1996 groundwater and surface water monitoring data are presented in Calendar Year 1996 Annual Groundwater Monitoring Report for the Upper East Fork Poplar Creek Hydrogeologic Regime at the US Department of Energy Y-12 Plant, Oak Ridge, Tennessee, along with the required data evaluations specified in the Resource Conservation and Recovery Act (RCRA) post-closure permit for the East Fork Regime. This report provides additional evaluation of the CY 1996 groundwater and surface water monitoring data with an emphasis on regime-wide groundwater contamination and long-term concentration trends for regulated and non-regulated monitoring parameters

Design of water-repellant coating using dual scale size of hybrid silica nanoparticles on polymer surface

Science.gov (United States)

Conti, J.; De Coninck, J.; Ghazzal, M. N.

2018-04-01

The dual-scale size of the silica nanoparticles is commonly aimed at producing dual-scale roughness, also called hierarchical roughness (Lotus effect). In this study, we describe a method to build a stable water-repellant coating with controlled roughness. Hybrid silica nanoparticles are self-assembled over a polymeric surface by alternating consecutive layers. Each one uses homogenously distributed silica nanoparticles of a particular size. The effect of the nanoparticle size of the first layer on the final roughness of the coating is studied. The first layer enables to adjust the distance between the silica nanoparticles of the upper layer, leading to a tuneable and controlled final roughness. An optimal size nanoparticle has been found for higher water-repellency. Furthermore, the stability of the coating on polymeric surface (Polycarbonate substrate) is ensured by photopolymerization of hybridized silica nanoparticles using Vinyl functional groups.

Effect of surface Fe-S hybrid structure on the activity of the perfect and reduced α-Fe2O3(001) for chemical looping combustion

Science.gov (United States)

Xiao, Xianbin; Qin, Wu; Wang, Jianye; Li, Junhao; Dong, Changqing

2018-05-01

Sulfurization of the gradually reduced Fe2O3 surfaces is inevitable while Fe2O3 is used as an oxygen carrier (OC) for coal chemical looping combustion (CLC), which will result in formation of Fe-S hybrid structure on the surfaces. The Fe-S hybrid structure will directly alter the reactivity of the surfaces. Therefore, detailed properties of Fe-S hybrid structure over the perfect and reduced Fe2O3(001) surfaces, and its effect on the interfacial interactions, including CO oxidization and decomposition on the surfaces, were investigated by using density functional theory (DFT) calculations. The S atom prefers to chemically bind to Fe site with electron transfer from the surfaces to the S atom, and a deeper reduction of Fe2O3(001) leads to an increasing interaction between S and Fe. The formation of Fe-S hybrid structure alters the electronic properties of the gradually reduced Fe2O3(001) surfaces, promoting CO oxidation on the surfaces ranging from Fe2O3 to FeO, but depressing carbon deposition on the surfaces ranging from FeO to Fe. The sulfurized FeO acts as a watershed to realize relatively high CO oxidation rate and low carbon deposition. Results provided a fundamental understanding for controlling and optimizing the CLC processes.

Effect of machining parameters on surface integrity of silicon carbide ceramic using end electric discharge milling and mechanical grinding hybrid machining

International Nuclear Information System (INIS)

Ji, Renjie; Liu, Yonghong; Zhang, Yanzhen; Cai, Baoping; Li, Xiaopeng; Zheng, Chao

2013-01-01

A novel hybrid process that integrates end electric discharge (ED) milling and mechanical grinding is proposed. The process is able to effectively machine a large surface area on SiC ceramic with good surface quality and fine working environmental practice. The polarity, pulse on-time, and peak current are varied to explore their effects on the surface integrity, such as surface morphology, surface roughness, micro-cracks, and composition on the machined surface. The results show that positive tool polarity, short pulse on-time, and low peak current cause a fine surface finish. During the hybrid machining of SiC ceramic, the material is mainly removed by end ED milling at rough machining mode, whereas it is mainly removed by mechanical grinding at finish machining mode. Moreover, the material from the tool can transfer to the workpiece, and a combination reaction takes place during machining.

Characterization of self-affinity in the global regime

Science.gov (United States)

Neimark, Alexander V.

1994-11-01

Methods for characterization of self-affine surfaces and measurements of their roughness exponents H are developed. It is shown that for smoothed surfaces, which underwent particular coarse graining or averaging of the small-scale fluctuations, the excess surface area Sex and the mean square root radius of curvature ac are related by two distinct asymptotic power laws if ac is well below or well above a certain crossover scale acr. In the local regime of self-affinity, when acSex~(ac/acr)-(1-H). In the global regime of self-affinity, when ac>>acr, Sex~(ac/acr)-2(1-H)/(2-H). The former scaling relationship is consistent with the well known definition of local fractal dimensions dloc=dtop+1-H. The latter scaling relationship offers alternatives for characterization of self-affinity over large scales by means of excess dimensions defined as dex=dtop+2(1-H)/(2-H) and can be used for determination of roughness exponents from the measurements provided in the global regime. The thermodynamic method of fractal analysis, proposed earlier for self-similar surfaces (A.V. Neimark, Pis'ma Zh. Eksp. Teor. Fiz. 51, 535 (1990) [JETP Lett. 51, 607 (1990)]; Physica A 191, 258 (1992)), is extended for self-affine surfaces for determination of fractal dimensions and roughness exponents from adsorption and capillary experimental data.

Advanced Nano hybrid Materials: Surface Modification and Applications

International Nuclear Information System (INIS)

Liu, L.H.; Metivier, R.; Wang, Sh.; Wang, Sh.; Hui Wang

2012-01-01

The field of functional nano scale hybrid materials is one of the most promising and rapidly emerging research areas in materials chemistry. Nano scale hybrid materials can be broadly defined as synthetic materials with organic and inorganic components that are linked together by noncovalent bonds (Class I, linked by hydrogen bond, electrostatic force, or van der Waals force) or covalent bonds (Class II) at nanometer scale. The unlimited possible combinations of the distinct properties of inorganic, organic, or even bioactive components in a single material, either in molecular or nano scale dimensions, have attracted considerable attention. This approach provides an opportunity to create a vast number of novel advanced materials with well-controlled structures and multiple functions. The unique properties of advanced hybrid nano materials can be advantageous to many fields, such as optical and electronic materials, biomaterials, catalysis, sensing, coating, and energy storage. In this special issue, the breadth of papers shows that the hybrid materials is attracting attention, because of both growing fundamental interest, and a route to new materials. Two review articles and seven research papers that report new results of hybrid materials should gather widespread interest.

Contact angle hysteresis on doubly periodic smooth rough surfaces in Wenzel's regime: The role of the contact line depinning mechanism.

Science.gov (United States)

Iliev, Stanimir; Pesheva, Nina; Iliev, Pavel

2018-04-01

We report here on the contact angle hysteresis, appearing when a liquid meniscus is in contact with doubly sinusoidal wavelike patterned surfaces in Wenzel's wetting regime. Using the full capillary model we obtain numerically the contact angle hysteresis as a function of the surface roughness factor and the equilibrium contact angle for a block case and a kink case contact line depinning mechanism. We find that the dependencies of the contact angle hysteresis on the surface roughness factor are different for the different contact line depinning mechanisms. These dependencies are different also for the two types of rough surfaces we studied. The relations between advancing, receding, and equilibrium contact angles are investigated. A comparison with the existing asymptotical, numerical, and experimental results is carried out.

Decamber Morphing Concepts by Using a Hybrid Trailing Edge Control Surface

Directory of Open Access Journals (Sweden)

Yavuz Yaman

2015-07-01

Full Text Available The idea of morphing is drawing extensive attention in aerospace technologies. Several different approaches like span, camber, twist, and sweep are finding applications. In this work, the concept of a trailing edge control surface which is capable of performing decamber morphing is explained. The upper and lower parts of the control surface undergo different chordwise elongations and the difference between these displacements gives rise to either camber or decamber morphing. The necessary force is achieved by the help of servo actuators. During the design, the structural analyses were done to determine the best viable options for the number of servo actuators, the location of the servo actuators, and the material properties used in the control surface. The control surface was designed of aluminum, composite and compliant materials hence was called a hybrid one. The structural analyses were conducted by using ANSYS® Workbench v14.0 package program. After finding the best viable design, which was made for in vacuo condition, the proposed design was also verified under the simulated aerodynamic loading. The aerodynamic loads were obtained from CFD analyses which were done with SU2 V3.2.3 open-source flow solver.

Analysis of the Two-Regime Method on Square Meshes

KAUST Repository

Flegg, Mark B.

2014-01-01

The two-regime method (TRM) has been recently developed for optimizing stochastic reaction-diffusion simulations [M. Flegg, J. Chapman, and R. Erban, J. Roy. Soc. Interface, 9 (2012), pp. 859-868]. It is a multiscale (hybrid) algorithm which uses stochastic reaction-diffusion models with different levels of detail in different parts of the computational domain. The coupling condition on the interface between different modeling regimes of the TRM was previously derived for onedimensional models. In this paper, the TRM is generalized to higher dimensional reaction-diffusion systems. Coupling Brownian dynamics models with compartment-based models on regular (square) two-dimensional lattices is studied in detail. In this case, the interface between different modeling regimes contains either flat parts or right-angle corners. Both cases are studied in the paper. For flat interfaces, it is shown that the one-dimensional theory can be used along the line perpendicular to the TRM interface. In the direction tangential to the interface, two choices of the TRM parameters are presented. Their applicability depends on the compartment size and the time step used in the molecular-based regime. The two-dimensional generalization of the TRM is also discussed in the case of corners. © 2014 Society for Industrial and Applied Mathematics.

Hybrid Multiphase CFD Solver for Coupled Dispersed/Segregated Flows in Liquid-Liquid Extraction

Directory of Open Access Journals (Sweden)

Kent E. Wardle

2013-01-01

Full Text Available The flows in stage-wise liquid-liquid extraction devices include both phase segregated and dispersed flow regimes. As a additional layer of complexity, for extraction equipment such as the annular centrifugal contactor, free-surface flows also play a critical role in both the mixing and separation regions of the device and cannot be neglected. Traditionally, computional fluid dynamics (CFD of multiphase systems is regime dependent—different methods are used for segregated and dispersed flows. A hybrid multiphase method based on the combination of an Eulerian multifluid solution framework (per-phase momentum equations and sharp interface capturing using Volume of Fluid (VOF on selected phase pairs has been developed using the open-source CFD toolkit OpenFOAM. Demonstration of the solver capability is presented through various examples relevant to liquid-liquid extraction device flows including three-phase, liquid-liquid-air simulations in which a sharp interface is maintained between each liquid and air, but dispersed phase modeling is used for the liquid-liquid interactions.

Spin-orbit torque in a three-dimensional topological insulator–ferromagnet heterostructure: Crossover between bulk and surface transport

KAUST Repository

Ghosh, Sumit; Manchon, Aurelien

2018-01-01

Current-driven spin-orbit torques are investigated in a heterostructure composed of a ferromagnet deposited on top of a three-dimensional topological insulator using the linear response formalism. We develop a tight-binding model of the heterostructure adopting a minimal interfacial hybridization scheme that promotes induced magnetic exchange on the topological surface states, as well as induced Rashba-like spin-orbit coupling in the ferromagnet. Therefore our model accounts for the spin Hall effect from bulk states together with inverse spin galvanic and magnetoelectric effects at the interface on equal footing. By varying the transport energy across the band structure, we uncover a crossover from surface-dominated to bulk-dominated transport regimes. We show that the spin density profile and the nature of the spin-orbit torques differ substantially in both regimes. Our results, which compare favorably with experimental observations, demonstrate that the large dampinglike torque reported recently is more likely attributed to the Berry curvature of interfacial states, while spin Hall torque remains small even in the bulk-dominated regime.

Spin-orbit torque in a three-dimensional topological insulator–ferromagnet heterostructure: Crossover between bulk and surface transport

KAUST Repository

Ghosh, Sumit

2018-04-02

Current-driven spin-orbit torques are investigated in a heterostructure composed of a ferromagnet deposited on top of a three-dimensional topological insulator using the linear response formalism. We develop a tight-binding model of the heterostructure adopting a minimal interfacial hybridization scheme that promotes induced magnetic exchange on the topological surface states, as well as induced Rashba-like spin-orbit coupling in the ferromagnet. Therefore our model accounts for the spin Hall effect from bulk states together with inverse spin galvanic and magnetoelectric effects at the interface on equal footing. By varying the transport energy across the band structure, we uncover a crossover from surface-dominated to bulk-dominated transport regimes. We show that the spin density profile and the nature of the spin-orbit torques differ substantially in both regimes. Our results, which compare favorably with experimental observations, demonstrate that the large dampinglike torque reported recently is more likely attributed to the Berry curvature of interfacial states, while spin Hall torque remains small even in the bulk-dominated regime.

Ternary hybrid polymeric nanocomposites through grafting of polystyrene on graphene oxide-TiO_2 by surface initiated atom transfer radical polymerization (SI-ATRP)

International Nuclear Information System (INIS)

Kumar, Arvind; Bansal, Ankushi; Behera, Babita; Jain, Suman L.; Ray, Siddharth S.

2016-01-01

A ternary hybrid of graphene oxide-titania-polystyrene (GO-TiO_2-PS) nanocomposite is developed where polystyrene composition is regulated by controlling growth of polymer chains and nanoarchitectonics is discussed. Graphene Oxide-TiO_2 (GO-TiO_2) nanocomposite is prepared by in-situ hydrothermal method and the surface is anchored with α-bromoisobutyryl bromide to activate GO-TiO_2 as initiator for polymerization. In-situ grafting of polystyrene through surface initiated atom transfer radical polymerization (SI- ATRP) on this Br-functionalized nano-composite initiator yields GO-TiO_2-PS ternary hybrid. Varying the monomer amount and keeping the concentration of initiator constant, polystyrene chain growth is regulated with narrow poly-dispersivity to achieve desired composition. This composite is well characterized by various analytical techniques like FTIR, XRD, DSC, SEM, TEM, and TGA. - Highlights: • Nanocomposite of ternary hybrid of GO-TiO_2 with polystyrene. • PS is surface grafted on GO-TiO_2. • Polymer chain lengths are well regulated by SI-ATRP living polymerization. • Thermal stability of this hybrid is relatively high.

What determines transitions between energy- and moisture-limited evaporative regimes?

Science.gov (United States)

Haghighi, E.; Gianotti, D.; Akbar, R.; Salvucci, G.; Entekhabi, D.

2017-12-01

The relationship between evaporative fraction (EF) and soil moisture (SM) has traditionally been used in atmospheric and land-surface modeling communities to determine the strength of land-atmosphere coupling in the context of the dominant evaporative regime (energy- or moisture-limited). However, recent field observations reveal that EF-SM relationship is not unique and could vary substantially with surface and/or meteorological conditions. This implies that conventional EF-SM relationships (exclusive of surface and meteorological conditions) are embedded in more complex dependencies and that in fact it is a multi-dimensional function. To fill the fundamental knowledge gaps on the important role of varying surface and meteorological conditions not accounted for by the traditional evaporative regime conceptualization, we propose a generalized EF framework using a mechanistic pore-scale model for evaporation and energy partitioning over drying soil surfaces. Nonlinear interactions among the components of the surface energy balance are reflected in a critical SM that marks the onset of transition between energy- and moisture-limited evaporative regimes. The new generalized EF framework enables physically based estimates of the critical SM, and provides new insights into the origin of land surface EF partitioning linked to meteorological input data and the evolution of land surface temperature during surface drying that affect the relative efficiency of surface energy balance components. Our results offer new opportunities to advance predictive capabilities quantifying land-atmosphere coupling for a wide range of present and projected meteorological input data.

Localized surface plasmon resonance (LSPR) study of DNA hybridization at single nanoparticle transducers

International Nuclear Information System (INIS)

Schneider, T.; Jahr, N.; Jatschka, J.; Csaki, A.; Stranik, O.; Fritzsche, W.

2013-01-01

The effect of DNA–DNA interaction on the localized surface plasmon resonance of single 80 nm gold nanoparticles is studied. Therefore, both the attachment of the capture DNA strands at the particle surface and the sequence-specific DNA binding (hybridization) of analyte DNA to the immobilized capture DNA is subject of investigations. The influence of substrate attachment chemistry, the packing density of DNA as controlled by an assisting layer of smaller molecules, and the distance as increased by a linker on the LSPR efficiency is investigated. The resulting changes in signal can be related to a higher hybridization efficiency of the analyte DNA to the immobilized capture DNA. The subsequent attachment of additional DNA strands to this system is studied, which allows for a multiple step detection of binding and an elucidation of the resulting resonance shifts. The detection limit was determined for the utilized DNA system by incubation with various concentration of analyte DNA. Although the method allows for a marker-free detection, we show that additional markers such as 20 nm gold particle labels increase the signal and thereby the sensitivity significantly. The study of resonance shift for various DNA lengths revealed that the resonance shift per base is stronger for shorter DNA molecules (20 bases) as compared to longer ones (46 bases).

Tamm-plasmon and surface-plasmon hybrid-mode based refractometry in photonic bandgap structures.

Science.gov (United States)

Das, Ritwick; Srivastava, Triranjita; Jha, Rajan

2014-02-15

The transverse magnetic (TM) polarized hybrid modes formed as a consequence of coupling between Tamm plasmon polariton (TM-TPP) mode and surface plasmon polariton (SPP) mode exhibit interesting dispersive features for realizing a highly sensitive and accurate surface plasmon resonance (SPR) sensor. We found that the TM-TPP modes, formed at the interface of distributed Bragg reflector and metal, are strongly dispersive as compared to SPP modes at optical frequencies. This causes an appreciably narrow interaction bandwidth between TM-TPP and SPP modes, which leads to highly accurate sensing. In addition, appropriate tailoring of dispersion characteristics of TM-TPP as well as SPP modes could ensure high sensitivity of a novel SPR platform. By suitably designing the Au/TiO₂/SiO₂-based geometry, we propose a TM-TPP/SPP hybrid-mode sensor and achieve a sensitivity ≥900  nm/RIU with high detection accuracy (≥30  μm⁻¹) for analyte refractive indices varying between 1.330 and 1.345 in 600-700 nm wavelength range. The possibility to achieve desired dispersive behavior in any spectral band makes the sensing configuration an extremely attractive candidate to design sensors depending on the availability of optical sources.

Growth Mechanism of Cluster-Assembled Surfaces: From Submonolayer to Thin-Film Regime

Science.gov (United States)

Borghi, Francesca; Podestà, Alessandro; Piazzoni, Claudio; Milani, Paolo

2018-04-01

Nanostructured films obtained by assembling preformed atomic clusters are of strategic importance for a wide variety of applications. The deposition of clusters produced in the gas phase onto a substrate offers the possibility to control and engineer the structural and functional properties of the cluster-assembled films. To date, the microscopic mechanisms underlying the growth and structuring of cluster-assembled films are poorly understood, and, in particular, the transition from the submonolayer to the thin-film regime is experimentally unexplored. Here we report the systematic characterization by atomic force microscopy of the evolution of the structural properties of cluster-assembled films deposited by supersonic cluster beam deposition. As a paradigm of nanostructured systems, we focus our attention on cluster-assembled zirconia films, investigating the influence of the building block dimensions on the growth mechanisms and roughening of the thin films, following the growth process from the early stages of the submonolayer to the thin-film regime. Our results demonstrate that the growth dynamics in the submonolayer regime determines different morphological properties of the cluster-assembled thin film. The evolution of the roughness with the number of deposited clusters reproduces the growth exponent of the ballistic deposition in the 2 +1 model from the submonolayer to the thin-film regime.

Influence of repetitive pulsed laser irradiation on the surface characteristics of an aluminum alloy in the melting regime

International Nuclear Information System (INIS)

Choi, Sung Ho; Jhang, Kyung Young

2015-01-01

We have investigated the influence of repetitive near-infrared (NIR) pulsed laser shots in the melting regime on the surface characteristics of an aluminum 6061-T6 alloy. Characteristics of interest include surface morphology, surface roughness, and surface hardness in the melted zone as well as the size of the melted zone. For this study, the proper pulse energy for inducing surface melting at one shot is selected using numerical simulations that calculate the variation in temperature at the laser beam spot for various input pulse energies in order to find the proper pulse energy for raising the temperature to the melting point. In this study, 130 mJ was selected as the input energy for a Nd:YAG laser pulse with a duration of 5 ns. The size of the melted zone measured using optical microscopy (OM) increased logarithmically with an increasing shot number. The surface morphology observed by scanning electron microscopy (SEM) clearly showed a re-solidified microstructure evolution after surface melting. The surface roughness and hardness were measured by atomic force microscopy (AFM) and nano-indentation, respectively. The surface roughness showed almost no variation due to the surface texturing after laser shots over 10. The hardness inside the melted zone was lower than that outside the zone because the β'' phase was transformed to a β phase or dissolved into a matrix.

Hybrid Doping of Few-Layer Graphene via a Combination of Intercalation and Surface Doping

KAUST Repository

Mansour, Ahmed

2017-05-23

Surface molecular doping of graphene has been shown to modify its work function and increase its conductivity. However, the associated shifts in work function and increases in carrier concentration are highly coupled and limited by the surface coverage of dopant molecules on graphene. Here we show that few-layer graphene (FLG) can be doped using a hybrid approach, effectively combining surface doping by larger (metal-)organic molecules, while smaller molecules, such as Br2 and FeCl3, intercalate into the bulk. Intercalation tunes the carrier concentration more effectively, whereas surface doping of intercalated FLG can be used to tune its work function without reducing the carrier mobility. This multi-modal doping approach yields a very high carrier density and tunable work function for FLG, demonstrating a new versatile platform for fabricating graphene-based contacts for electronic, optoelectronic and photovoltaic applications.

Hybrid Doping of Few-Layer Graphene via a Combination of Intercalation and Surface Doping

KAUST Repository

Mansour, Ahmed; Kirmani, Ahmad R.; Barlow, Stephen; Marder, Seth R.; Amassian, Aram

2017-01-01

Surface molecular doping of graphene has been shown to modify its work function and increase its conductivity. However, the associated shifts in work function and increases in carrier concentration are highly coupled and limited by the surface coverage of dopant molecules on graphene. Here we show that few-layer graphene (FLG) can be doped using a hybrid approach, effectively combining surface doping by larger (metal-)organic molecules, while smaller molecules, such as Br2 and FeCl3, intercalate into the bulk. Intercalation tunes the carrier concentration more effectively, whereas surface doping of intercalated FLG can be used to tune its work function without reducing the carrier mobility. This multi-modal doping approach yields a very high carrier density and tunable work function for FLG, demonstrating a new versatile platform for fabricating graphene-based contacts for electronic, optoelectronic and photovoltaic applications.

A Hybrid Circuit for Spoof Surface Plasmons and Spatial Waveguide Modes to Reach Controllable Band-Pass Filters.

Science.gov (United States)

Zhang, Qian; Zhang, Hao Chi; Wu, Han; Cui, Tie Jun

2015-11-10

We propose a hybrid circuit for spoof surface plasmon polaritons (SPPs) and spatial waveguide modes to develop new microwave devices. The hybrid circuit includes a spoof SPP waveguide made of two anti-symmetric corrugated metallic strips and a traditional substrate integrated waveguide (SIW). From dispersion relations, we show that the electromagnetic waves only can propagate through the hybrid circuit when the operating frequency is less than the cut-off frequency of the SPP waveguide and greater than the cut-off frequency of SIW, generating efficient band-pass filters. We demonstrate that the pass band is controllable in a large range by designing the geometrical parameters of SPP waveguide and SIW. Full-wave simulations are provided to show the large adjustability of filters, including ultra wideband and narrowband filters. We fabricate a sample of the new hybrid device in the microwave frequencies, and measurement results have excellent agreements to numerical simulations, demonstrating excellent filtering characteristics such as low loss, high efficiency, and good square ratio. The proposed hybrid circuit gives important potential to accelerate the development of plasmonic integrated functional devices and circuits in both microwave and terahertz frequencies.

Hybrid micro/nanostructural surface offering improved stress distribution and enhanced osseointegration properties of the biomedical titanium implant.

Science.gov (United States)

Hou, Ping-Jen; Ou, Keng-Liang; Wang, Chin-Chieh; Huang, Chiung-Fang; Ruslin, Muhammad; Sugiatno, Erwan; Yang, Tzu-Sen; Chou, Hsin-Hua

2018-03-01

The aim of the present study was to investigate the surface characteristic, biomechanical behavior, hemocompatibility, bone tissue response and osseointegration of the optimal micro-arc oxidation surface-treated titanium (MST-Ti) dental implant. The surface characteristic, biomechanical behavior and hemocompatibility of the MST-Ti dental implant were performed using scanning electron microscope, finite element method, blood dripping and immersion tests. The mini-pig model was utilized to evaluate the bone tissue response and osseointegration of the MST-Ti dental implant in vivo. Data were analyzed by analysis of variance using the Student's t-test (P ≤ 0.05). The hybrid volcano-like micro/nanoporous structure was formed on the surface of the MST-Ti dental implant. The hybrid volcano-like micro/nanoporous surface played an important role to improve the stress transfer between fixture, cortical bone and cancellous bone for the MST-Ti dental implant. Moreover, the MST-Ti implant was considered to have the outstanding hemocompatibility. In vivo testing results showed that the bone-to-implant contact (BIC) ratio significantly altered as the implant with micro/nanoporous surface. After 12 weeks of implantation, the MST-Ti dental implant group exhibited significantly higher BIC ratio than the untreated dental implant group. In addition, the MST-Ti dental implant group also presented an enhancing osseointegration, particularly in the early stages of bone healing. It can be concluded that the micro-arc oxidation approach induced the formation of micro/nanoporous surface is a promising and reliable alternative surface modification for Ti dental implant applications. Copyright © 2017 Elsevier Ltd. All rights reserved.

Hybrid inflation exit through tunneling

International Nuclear Information System (INIS)

Garbrecht, Bjoern; Konstandin, Thomas

2007-01-01

For hybrid inflationary potentials, we derive the tunneling rate from field configurations along the flat direction towards the waterfall regime. This process competes with the classically rolling evolution of the scalar fields and needs to be strongly subdominant for phenomenologically viable models. Tunneling may exclude models with a mass scale below 10 12 GeV, but can be suppressed by small values of the coupling constants. We find that tunneling is negligible for those models, which do not require fine tuning in order to cancel radiative corrections, in particular for GUT-scale SUSY inflation. In contrast, electroweak scale hybrid inflation is not viable, unless the inflaton-waterfall field coupling is smaller than approximately 10 -11

Stochastic effects in hybrid inflation

Science.gov (United States)

Martin, Jérôme; Vennin, Vincent

2012-02-01

Hybrid inflation is a two-field model where inflation ends due to an instability. In the neighborhood of the instability point, the potential is very flat and the quantum fluctuations dominate over the classical motion of the inflaton and waterfall fields. In this article, we study this regime in the framework of stochastic inflation. We numerically solve the two coupled Langevin equations controlling the evolution of the fields and compute the probability distributions of the total number of e-folds and of the inflation exit point. Then, we discuss the physical consequences of our results, in particular, the question of how the quantum diffusion can affect the observable predictions of hybrid inflation.

A hybrid 3D SEM reconstruction method optimized for complex geologic material surfaces.

Science.gov (United States)

Yan, Shang; Adegbule, Aderonke; Kibbey, Tohren C G

2017-08-01

Reconstruction methods are widely used to extract three-dimensional information from scanning electron microscope (SEM) images. This paper presents a new hybrid reconstruction method that combines stereoscopic reconstruction with shape-from-shading calculations to generate highly-detailed elevation maps from SEM image pairs. The method makes use of an imaged glass sphere to determine the quantitative relationship between observed intensity and angles between the beam and surface normal, and the detector and surface normal. Two specific equations are derived to make use of image intensity information in creating the final elevation map. The equations are used together, one making use of intensities in the two images, the other making use of intensities within a single image. The method is specifically designed for SEM images captured with a single secondary electron detector, and is optimized to capture maximum detail from complex natural surfaces. The method is illustrated with a complex structured abrasive material, and a rough natural sand grain. Results show that the method is capable of capturing details such as angular surface features, varying surface roughness, and surface striations. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of different polishing systems on the surface roughness of nano-hybrid composites

OpenAIRE

Brijesh Patel; Naveen Chhabra; Disha Jain

2016-01-01

Objective: The study aimed to investigate the influence of different polishing systems on the surface roughness of nano-hybrid composite resins. Background: Different shapes of polishing systems are available according to the site of work. To minimize variability, a new system with single shape is developed that can be utilized in both anterior as well as posterior teeth. Materials and Methods: Seventy composite discs were fabricated using Teflon well (10 mm × 3 mm). Two main group of...

High surface enhanced Raman scattering activity of BN nanosheets–Ag nanoparticles hybrids

International Nuclear Information System (INIS)

Yang, Shanshan; Zhang, Zhaochun; Zhao, Jun; Zheng, Houli

2014-01-01

Highlights: • Boron nitride–silver nanohybrid was acquired through a liquid-phase reducing route. • The composite shown a high-quality SERS activity. • 2-Mercaptobenzimidazole was chemisorbed on silver surface in vertical orientation. -- Abstract: A facile liquid-phase reducing route was developed to modify boron nitride (BN) nanosheets with silver nanoparticles (AgNPs) in order to fabricate BN–AgNPs hybrids with high surface enhanced Raman scattering (SERS) activity. The layered structure and morphology of BN–AgNPs nanohybrids were characterized by transmission electron microscopy and atomic force microscopy, meanwhile, Fourier transform infrared spectroscopy and ultraviolet–visible were used for studying optical properties and surface plasmon resonance applied to the optical sensor. The SERS of adsorbed 2-mercaptobenzimidazole (MBI) molecule was investigated which shown that the BN–AgNPs substrate exhibited a very strong SERS activity, offering a great potential application in molecular probe sensor. On the basis of the analysis of SERS and the Raman surface selection rules, we could draw a conclusion that the MBI molecule was adsorbed upright on the AgNPs surface through the sulphur and nitrogen atoms. What is more, the cyclic voltammetry experiment indicated the electrochemically irreversible behavior of BN–AgNPs nanohybrids in KCl solution

A hybrid approach to the surface biofunctionalization of nanostructured porous alumina

Energy Technology Data Exchange (ETDEWEB)

Silvan, Miguel Manso; Ruiz, Josefa Predestinacion Garcia [Departamento de Fisica Aplicada y Departamento de Biologia Molecular, Facultad de Ciencias, Universidad Autonoma de Madrid, Unidad Asociada GMNF (ICMM-CSIC), 28049 Madrid (Spain); Centro de Investigaciones Biomedicas en Red, Bioingenieria Biomateriales y Nanomedicina (CIBERbbn) (Spain); Gonzalez, Ruy Sanz [Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Cientificas, 28049 Madrid (Spain); Velez, Manuel Hernandez [Departamento de Fisica Aplicada y Departamento de Biologia Molecular, Facultad de Ciencias, Universidad Autonoma de Madrid, Unidad Asociada GMNF (ICMM-CSIC), 28049 Madrid (Spain)

2010-02-15

The application of nanostructured porous alumina templates as a solid support in biomedical assays requires a surface biofunctionalization process that has been addressed in this work by an hybrid aminopropyl-triethoxysilane/tetraisopropyl-orthotitanate (APTS/ TIPT) self assembled film. The nanostructured porous alumina templates are activated in a peroxide solution before immersion in the biofunctionalizing APTS/TIPT solution. The biofunctionalization process was followed up by UV-vis spectroscopy, which confirmed the modification of the dielectric structure of the alumina surface. The influence of the biofunctionalization step in an immunological assay was carried out by fluorescence microscopy. Results confirm the gain in activity after the immobilization of an FITC labelled mouse Igg. Specific biological recognition in a bovine serum albumin (BSA)-antiBSA assay is proved afterwards by shifts observed in the reflectance interferograms thus providing a fast biosensing transducer platform. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

The screening effects of the screened exchange hybrid functional in surface systems: A case study on the CO/Pt(111) problem

Energy Technology Data Exchange (ETDEWEB)

Li, H., E-mail: li-huanglong@mail.tsinghua.edu.cn [Department of Precision Instrument, Tsinghua University, Beijing, 100084 (China); Gillen, R. [Institut für Festkörperphysik. Technische Universität Berlin. Hardenbergstr. 36, 10623 Berlin (Germany); Robertson, J., E-mail: jr214@cam.ac.uk [Engineering Department, University of Cambridge, Cambridge CB2 1PZ (United Kingdom)

2016-06-15

The screened exchange (sX) hybrid functional has been widely used in computational material science. Although it has widely been studied in bulk systems, less is known about its functional behavior in surface systems which are crucial to many technologies such as materials synthesis and nano-electronic devices. Assessing the screening dependent functional behaviors in the surface systems is therefore important for its application in such systems. In this work, we investigate the screening effects of the sX in CO adsorption on Pt(111) surface. The differences between the sX and Heyd-Scuseria-Ernzerhof (HSE06) hybrid functionals, and the effects of screening parameters are studied. The screening has two effects: first, the HOMO-LUMO gap is screening dependent. This affects the site preference most significantly. In this work, atop adsorption of CO/Pt(111) is predicted by the hybrid functionals with screened exchange potential. The sX(1.44) gives the largest HOMO-LUMO gap for the isolated CO molecule. The adsorption energy difference between the atop and fcc site is also the largest by the sX(1.44) which is explained by the reduced metal d states to the CO 2π* state back-donation, with stronger effect for the fcc adsorption than for the atop adsorption; second, the adsorption energy is screening dependent. This can be seen by comparing the sX(2.38) and HSE06 which have different screening strengths. They show similar surface band structures for the CO adsorption but different adsorption energies, which is explained by the stronger CO 5σ state to the metal d states donation or the effectively screened Pauli repulsion. This work underlines the screening strength as a main difference between sX and HSE06, as well as an important hybrid functional parameter for surface calculation.

Diaphite, a new type of surface with mixed sp{sup 2}-sp{sup 3} hybridization for adsorption and functionalization

Energy Technology Data Exchange (ETDEWEB)

Radosinski, Lukasz, E-mail: lukasz.radosinski@pwr.edu.pl [Wroclaw University of Science and Technology, Chemistry Department, Group of Bioprocess and Biomedical Engineering, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw (Poland); Formalik, Filip [Wroclaw University of Science and Technology, Chemistry Department, Group of Bioprocess and Biomedical Engineering, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw (Poland); Olejniczak, Adam [Department of Spectroscopy of Excited States, Institute of Low Temperature and Structure Research, Polish Academy of Sciences, Okolna 2, 50-422 Wroclaw (Poland); Radosz, Andrzej [Wroclaw University of Science and Technology, Faculty of Fundamental Problems of Technology, Department of Quantum Technologies, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw (Poland)

2017-05-15

Highlights: • Recent discoveries show a possibility of photoinduced formation of a structure of mixed sp{sub 2}-sp{sub 3} hybridization out of graphite and graphene–diaphite. • Ab initio and molecular mechanics calculations indicate that the surface exhibits large enhancement of binding energy due to favorable sp{sub 3} like hybridization. • The binding energy varies upon configuration of occupied adsorption sites and the adsorption sites form a regular bed-like matrix. - Abstract: We theoretically study a new carbon phase with mixed sp{sup 2}-sp{sup 3} bond hybridization called diaphite. Using ab initio calculations and the adaptive intermolecular reactive bond order (AIREBO) potential approach, we show that the surface of this structure exhibits enhanced adsorption capabilities. Specifically, using hydrogen as a test adsorbate, we calculate that the chemical binding energy, depending on the configuration of hydrogen atoms, varies from 2.08 to 2.9 eV. Furthermore, the adsorption sites form a regular matrix; thus, we postulate that this new stable carbon phase may be a universal matrix for functionalization.

Experimental study of surface insulated-standard hybrid tungsten planar wire array Z-pinches at “QiangGuang-I” facility

Energy Technology Data Exchange (ETDEWEB)

Sheng, Liang; Peng, Bodong; Yuan, Yuan; Zhang, Mei; Zhao, Chen; Zhao, Jizhen; Wang, Liangping [State Key Laboratory of Intense Pulsed Radiation Simulation and Effect (Northwest Institute of Nuclear Technology), Xi' an 710024 (China); Li, Yang, E-mail: liyang@nint.ac.cn; Li, Mo [State Key Laboratory of Intense Pulsed Radiation Simulation and Effect (Northwest Institute of Nuclear Technology), Xi' an 710024 (China); Xi' an Jiaotong University, Xi' an 710049 (China)

2016-01-15

The experimental results of the insulated-standard hybrid wire array Z pinches carried out on “QiangGuang-I” facility at Northwest Institute of Nuclear Technology were presented and discussed. The surface insulating can impose a significant influence on the dynamics and radiation characteristics of the hybrid wire array Z pinches, especially on the early stage (t/t{sub imp} < 0.6). The expansion of insulated wires at the ablation stage is suppressed, while the streams stripped from the insulated wires move faster than that from the standard wires. The foot radiation of X-ray is enhanced by increment of the number of insulated wires, 19.6 GW, 33.6 GW, and 68.6 GW for shots 14037S, 14028H, and 14039I, respectively. The surface insulation also introduces nonhomogeneity along the single wire—the streams move much faster near the electrodes. The colliding boundary of the hybrid wire array Z pinches is bias to the insulated side approximately 0.6 mm.

Sensitive electrochemiluminescence biosensor based on Au-ITO hybrid bipolar electrode amplification system for cell surface protein detection.

Science.gov (United States)

Wu, Mei-Sheng; Yuan, Da-Jing; Xu, Jing-Juan; Chen, Hong-Yuan

2013-12-17

Here we developed a novel hybrid bipolar electrode (BPE)-electrochemiluminescence (ECL) biosensor based on hybrid bipolar electrode (BPE) for the measurement of cancer cell surface protein using ferrocence (Fc) labeled aptamer as signal recognition and amplification probe. According to the electric neutrality of BPE, the cathode of U-shaped ITO BPE was electrochemically deposited by Au nanoparticles (NPs) to enhance its conductivity and surface area, decrease the overpotential of O2 reduction, which would correspondingly increase the oxidation current of Ru(bpy)3(2+)/tripropylamine (TPA) on the anode of BPE and resulting a ∼4-fold enhancement of ECL intensity. Then a signal amplification strategy was designed by introducing Fc modified aptamer on the anode surface of BPE through hybridization for detecting the amount of mucin-1 on MCF-7 cells. The presence of Fc could not only inhibit the oxidation of Ru(bpy)3(2+) because of its lower oxidation potential, its oxidation product Fc(+) could also quench the ECL of Ru(bpy)3(2+)/TPA by efficient energy-transfer from the excited-state Ru(bpy)3(2+)* to Fc(+), making the ECL intensity greatly quenched. On the basis of the cathodic Au NPs induced ECL enhancing coupled with anodic Fc induced signal quenching amplification, the approach allowed detection of mucin-1 aptamer at a concentration down to 0.5 fM and was capable of detecting a minimum of 20 MCF-7 cells. Besides, the amount of mucin-1 on MCF-7 cells was calculated to be 9041 ± 388 molecules/cell. This approach therefore shows great promise in bioanalysis.

In situ hybridization of superparamagnetic iron-biomolecule nanoparticles.

Science.gov (United States)

Moghimi, Nafiseh; Donkor, Apraku David; Mohapatra, Mamata; Thomas, Joseph Palathinkal; Su, Zhengding; Tang, Xiaowu Shirley; Leung, Kam Tong

2014-07-23

The increase in interest in the integration of organic-inorganic nanostructures in recent years has promoted the use of hybrid nanoparticles (HNPs) in medicine, energy conversion, and other applications. Conventional hybridization methods are, however, often long, complicated, and multistepped, and they involve biomolecules and discrete nanostructures as separate entities, all of which hinder the practical use of the resulting HNPs. Here, we present a novel, in situ approach to synthesizing size-specific HNPs using Fe-biomolecule complexes as the building blocks. We choose an anticancer peptide (p53p, MW 1.8 kDa) and an enzyme (GOx, MW 160 kDa) as model molecules to demonstrate the versatility of the method toward different types of molecules over a large size range. We show that electrostatic interaction for complex formation of metal hydroxide ion with the partially charged side of biomolecule in the solution is the key to hybridization of metal-biomolecule materials. Electrochemical deposition is then used to produce hybrid NPs from these complexes. These HNPs with controllable sizes ranging from 30 nm to 3.5 μm are found to exhibit superparamagnetic behavior, which is a big challenge for particles in this size regime. As an example of greatly improved properties and functionality of the new hybrid material, in vitro toxicity assessment of Fe-GOx HNPs shows no adverse effect, and the Fe-p53p HNPs are found to selectively bind to cancer cells. The superparamagnetic nature of these HNPs (superparamagnetic even above the size regime of 15-20 nm!), their biocompatibility, and the direct integration approach are fundamentally important to biomineralization and general synthesis strategy for bioinspired functional materials.

Channeling regimes in ion surface scattering

NARCIS (Netherlands)

Robin, A; Heiland, W

We report on surface channeling experiments of singly charged ions on single crystal surfaces of Pt(1 1 0) and Pd(1 1 0). Using a time-of-flight system installed in forward direction we analyze the energy distribution of the scattered projectiles. By variation of the primary energy and the angle of

Exotic hybrid mesons in hard electroproduction

International Nuclear Information System (INIS)

Anikin, I.V.; Pire, B.; Szymanowski, L.; Teryaev, O.V.; Wallon, S.

2005-01-01

We estimate the sizeable cross section for deep exclusive electroproduction of an exotic J PC =1 -+ hybrid meson in the Bjorken regime. The production amplitude scales like the one for usual meson electroproduction, i.e., as 1/Q 2 . This is due to the nonvanishing leading twist distribution amplitude for the hybrid meson, which may be normalized thanks to its relation to the energy-momentum tensor and to the QCD sum rules technique. The hard amplitude is considered up to next-to-leading order in α S and we explore the consequences of fixing the renormalization scale ambiguity through the Brodsky-Lepage-Mackenzie (BLM) procedure. We study the particular case where the hybrid meson decays through a πη meson pair. We discuss the πη generalized distribution amplitude and then calculate the production amplitude for this process. We propose a forward-backward asymmetry in the production of π and η mesons as a signal for the hybrid meson production. We briefly comment on hybrid electroproduction at very high energy, in the diffractive limit where a QCD Odderon exchange mechanism should dominate. The conclusion of our study is that hard electroproduction is a promising way to study exotic hybrid mesons, in particular, at JLAB, HERA (HERMES), or CERN (Compass)

Hybrid spin-nanomechanics with single spins in diamond mechanical oscillators

OpenAIRE

Barfuss, Arne

2017-01-01

Hybrid spin-oscillator systems, formed by single spins coupled to mechanical oscillators, have attracted ever-increasing attention over the past few years, triggered largely by the prospect of employing such devices as high-performance nanoscale sensors or transducers in multi-qubit networks. Provided the spin-oscillator coupling is strong and robust, such systems can even serve as test-beds for studying macroscopic objects in the quantum regime. In this thesis we present a novel hybrid sp...

Surface Modifier-Free Organic-Inorganic Hybridization To Produce Optically Transparent and Highly Refractive Bulk Materials Composed of Epoxy Resins and ZrO2 Nanoparticles.

Science.gov (United States)

Enomoto, Kazushi; Kikuchi, Moriya; Narumi, Atsushi; Kawaguchi, Seigou

2018-04-25

Surface modifier-free hybridization of ZrO 2 nanoparticles (NPs) with epoxy-based polymers is demonstrated for the first time to afford highly transparent and refractive bulk materials. This is achieved by a unique and versatile hybridization via the one-pot direct phase transfer of ZrO 2 NPs from water to epoxy monomers without any aggregation followed by curing with anhydride. Three types of representative epoxy monomers, bisphenol A diglycidyl ether (BADGE), 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexane carboxylate (CEL), and 1,3,5-tris(3-(oxiran-2-yl)propyl)-1,3,5-triazinane-2,4,6-trione (TEPIC), are used to produce transparent viscous dispersions. The resulting ZrO 2 NPs are thoroughly characterized using dynamic light scattering (DLS), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR), and solid-state 13 C CP/MAS NMR measurements. The results from DLS and TEM analyses indicate nanodispersion of ZrO 2 into epoxy monomers as a continuous medium. A surface modification mechanism and the binding fashion during phase transfer are proposed based on the FT-IR and solid-state 13 C CP/MAS NMR measurements. Epoxy-based hybrid materials with high transparency and refractive index are successfully fabricated by heat curing or polymerizing a mixture of monomers containing epoxy-functionalized ZrO 2 NPs and methylhexahydrophthalic anhydride in the presence of a phosphoric catalyst. The TEM and small-angle X-ray scattering measurements of the hybrids show a nanodispersion of ZrO 2 in the epoxy networks. The refractive index at 594 nm ( n 594 ) increases up to 1.765 for BADGE-based hybrids, 1.667 for CEL-based hybrids, and 1.693 for TEPIC-based hybrids. Their refractive indices and Abbe's numbers are quantitatively described by the Lorentz-Lorenz effective medium expansion theory. Their transmissivity is also reasonably explained using Fresnel refraction, Rayleigh scattering, and the Lambert-Beer theories. This surface modifier-free hybridization

Building regulatory enforcement regimes : Comparative analysis of private sector involvement in the enforcement of public building regulations

NARCIS (Netherlands)

Van der Heijden, J.J.

2009-01-01

It is often assumed that traditional regulatory regimes centered on governmental action will benefit from greater private sector involvement. And, under the catchy phrase "from government to governance" globally a wide variety of hybrid forms of governance has emerged. However, little empirical

Hierarchically porous carbon/polyaniline hybrid for use in supercapacitors.

Science.gov (United States)

Joo, Min Jae; Yun, Young Soo; Jin, Hyoung-Joon

2014-12-01

A hierarchically porous carbon (HPC)/polyaniline (PANI) hybrid electrode was prepared by the polymerization of PANI on the surface of the HPC via rapid-mixing polymerization. The surface morphologies and chemical composition of the HPC/PANI hybrid electrode were characterized using transmission electron microscopy and X-ray photoelectron spectroscopy (XPS), respectively. The surface morphologies and XPS results for the HPC, PANI and HPC/PANI hybrids indicate that PANI is coated on the surface of HPC in the HPC/PANI hybrids which have two different nitrogen groups as a benzenoid amine (-NH-) peak and positively charged nitrogen (N+) peak. The electrochemical performances of the HPC/PANI hybrids were analyzed by performing cyclic voltammetry and galvanostatic charge-discharge tests. The HPC/PANI hybrids showed a better specific capacitance (222 F/g) than HPC (111 F/g) because of effect of pseudocapacitor behavior. In addition, good cycle stabilities were maintained over 1000 cycles.

Electrically driven hybrid Si/III-V Fabry-Pérot lasers based on adiabatic mode transformers.

Science.gov (United States)

Ben Bakir, B; Descos, A; Olivier, N; Bordel, D; Grosse, P; Augendre, E; Fulbert, L; Fedeli, J M

2011-05-23

We report the first demonstration of an electrically driven hybrid silicon/III-V laser based on adiabatic mode transformers. The hybrid structure is formed by two vertically superimposed waveguides separated by a 100-nm-thick SiO2 layer. The top waveguide, fabricated in an InP/InGaAsP-based heterostructure, serves to provide optical gain. The bottom Si-waveguides system, which supports all optical functions, is constituted by two tapered rib-waveguides (mode transformers), two distributed Bragg reflectors (DBRs) and a surface-grating coupler. The supermodes of this hybrid structure are controlled by an appropriate design of the tapers located at the edges of the gain region. In the middle part of the device almost all the field resides in the III-V waveguide so that the optical mode experiences maximal gain, while in regions near the III-V facets, mode transformers ensure an efficient transfer of the power flow towards Si-waveguides. The investigated device operates under quasi-continuous wave regime. The room temperature threshold current is 100 mA, the side-mode suppression ratio is as high as 20 dB, and the fiber-coupled output power is ~7 mW.

Tuning up an oldtimer: hybrid Monte Carlo with Wilson fermions

International Nuclear Information System (INIS)

Schilling, K.; Hannemann, V.; Lippert, T.; Noeckel, B.

1995-01-01

We show that BiCGStab inversion algorithm helps to speed up by 50% the computation of the fermionic force inside the Hybrid Monte Carlo (HMC) simulation of full QCD with Wilson fermions, in the chiral regime of small quark masses. ((orig.))

Preparation of Mg(OH)_2 hybrid pigment by direct precipitation and graft onto cellulose fiber via surface-initiated atom transfer radical polymerization

International Nuclear Information System (INIS)

Wang, Xiao; Zhang, Yue; Lv, Lihua; Cui, Yongzhu; Wei, Chunyan; Pang, Guibing

2016-01-01

Graphical abstract: - Highlights: • Adsorbed anionic dye molecules are conducive to preferential growth of (0 0 1) plane of Mg(OH)_2 crystal for Mg(OH)_2 pigments. • Uniform coverage of nanosized Mg(OH)_2 pigments on fiber surface is achieved via surface-initiated ATRP. • About 4 wt% of Mg(OH)_2 pigment on fiber surface shortens nearly half of burning time of cellulose. - Abstract: Mg(OH)_2 flame retardant hybrid pigment is synthesized through simultaneous solution precipitation and adsorption of anionic dyes (C.I. Acid Red 6). The Mg(OH)_2 hybrid pigment bearing vinyl groups after surface silane modification is immobilized onto the surface of bromo end-functional cellulose fiber by atom transfer radical polymerization (ATRP). The morphology and structure of Mg(OH)_2 pigments and cellulose fibers grafted with modified pigments are characterized. The thermal properties, flammability and color fastness of cellulose fibers grafted with modified pigments are measured. The results reveal that anionic dye molecules are adsorbed onto Mg(OH)_2 crystals and affect the formation of lamella-like Mg(OH)_2 crystals. The cellulose fiber grafted with modified Mg(OH)_2 hybrid pigment absorbs about four times heat more than original cellulose fiber with about 4% immobilization ratio of pigment, which shortens nearly half of afterflame time and afterglow time.

Design of hybrid electron linac with standing wave buncher and traveling wave structure

International Nuclear Information System (INIS)

Kutsaev, S.V.; Sobenin, N.P.; Smirnov, A.Yu.; Kamenschikov, D.S.; Gusarova, M.A.; Nikolskiy, K.I.; Zavadtsev, A.A.; Lalayan, M.V.

2011-01-01

A disk-loaded waveguide (DLW) is the most common structure for compact linear accelerators working in a traveling wave (TW) regime. Among its advantages are high shunt impedance and manufacturing simplicity. The other popular structure is an on-axis coupled bi-periodical accelerating structure (BAS) that works in standing wave (SW) regime. Both the standing and the traveling wave regimes have their own advantages and disadvantages. The design of the hybrid accelerator with SW buncher and TW accelerating section presented in this paper unites the advantages of both regimes. For example, the buncher in the hybrid accelerator is shorter than in a pure TW accelerator, and it requires no solenoid; this structure is more technologically convenient as it does not require a circulator. The other way to combine the advantages of DLW and BAS is to design a magnetic coupled disk-loaded waveguide (DLW-M). This paper also presents the results of a survey study that analyzed the electrodynamical parameters of such a structure and compared them with those of DLW. The experimental data is also presented. Higher order modes, multipacting discharge and thermal simulations show that DLW-M structure is more preferable to classical DLW.

A novel hybrid surface micromachined segmented mirror for large aperture laser applications

Science.gov (United States)

Li, Jie; Chen, Haiqing; Yu, Hongbin

2006-07-01

A novel hybrid surface micromachined segmented mirror array is described. This device is capable of scaling to large apertures for correcting time-varying aberrations in laser applications. Each mirror is composed of bottom electrode, support part, and mirror plate, in which a T-shaped beam structure is used to support the mirror plate. It can provide mirror with vertical movement and rotation around two horizontal axes. The test results show that the maximum deflection along the vertical direction of the mirror plate is 2 microns, while the rotation angles around x and y axes are +-2.3 deg. and +-1.45 deg., respectively.

Ternary hybrid polymeric nanocomposites through grafting of polystyrene on graphene oxide-TiO{sub 2} by surface initiated atom transfer radical polymerization (SI-ATRP)

Energy Technology Data Exchange (ETDEWEB)

Kumar, Arvind; Bansal, Ankushi; Behera, Babita; Jain, Suman L.; Ray, Siddharth S., E-mail: ssray@iip.res.in

2016-04-01

A ternary hybrid of graphene oxide-titania-polystyrene (GO-TiO{sub 2}-PS) nanocomposite is developed where polystyrene composition is regulated by controlling growth of polymer chains and nanoarchitectonics is discussed. Graphene Oxide-TiO{sub 2} (GO-TiO{sub 2}) nanocomposite is prepared by in-situ hydrothermal method and the surface is anchored with α-bromoisobutyryl bromide to activate GO-TiO{sub 2} as initiator for polymerization. In-situ grafting of polystyrene through surface initiated atom transfer radical polymerization (SI- ATRP) on this Br-functionalized nano-composite initiator yields GO-TiO{sub 2}-PS ternary hybrid. Varying the monomer amount and keeping the concentration of initiator constant, polystyrene chain growth is regulated with narrow poly-dispersivity to achieve desired composition. This composite is well characterized by various analytical techniques like FTIR, XRD, DSC, SEM, TEM, and TGA. - Highlights: • Nanocomposite of ternary hybrid of GO-TiO{sub 2} with polystyrene. • PS is surface grafted on GO-TiO{sub 2}. • Polymer chain lengths are well regulated by SI-ATRP living polymerization. • Thermal stability of this hybrid is relatively high.

Composite Layers “MgAl Intermetalic Layer / PVD Coating” Obtained On The AZ91D Magnesium Alloy By Different Hybrid Surface Treatment Methods

Directory of Open Access Journals (Sweden)

Smolik J.

2015-06-01

Full Text Available Magnesium alloys have very interesting physical properties which make them ‘materials of the future’ for tools and machine components in many industry areas. However, very low corrosion and tribological resistance of magnesium alloys hampers the implementation of this material in the industry. One of the methods to improve the properties of magnesium alloys is the application of the solutions of surface engineering like hybrid technologies. In this paper, the authors compare the tribological and corrosion properties of two types of “MgAlitermetalic / PVD coating” composite layers obtained by two different hybrid surface treatment technologies. In the first configuration, the “MgAlitermetalic / PVD coating” composite layer was obtained by multisource hybrid surface treatment technology combining magnetron sputtering (MS, arc evaporation (AE and vacuum heating methods. The second type of a composite layer was prepared using a hybrid technology combined with a diffusion treatment process in Al-powder and the electron beam evaporation (EB method. The authors conclude, that even though the application of „MgAlitermetalic / PVD coating” composite layers can be an effective solution to increase the abrasive wear resistance of magnesium alloys, it is not a good solution to increase its corrosion resistance.

Hybrid Electric Vehicle Experimental Model with CAN Network Real Time Control

Directory of Open Access Journals (Sweden)

RATOI, M.

2010-05-01

Full Text Available In this paper an experimental model with a distributed control system of a hybrid electrical vehicle is presented. A communication CAN network of high speed (1 Mbps assures a distributed control of the all components. The modeling and the control of different operating regimes are realized on an experimental test-bench of a hybrid electrical vehicle. The experimental results concerning the variations of the mains variables (currents, torques, speeds are presented.

Preliminary Study on Hybrid Computational Phantom for Radiation Dosimetry Based on Subdivision Surface

International Nuclear Information System (INIS)

Jeong, Jong Hwi; Choi, Sang Hyoun; Cho, Sung Koo; Kim, Chan Hyeong

2007-01-01

The anthropomorphic computational phantoms are classified into two groups. One group is the stylized phantoms, or MIRD phantoms, which are based on mathematical representations of the anatomical structures. The shapes and positions of the organs and tissues in these phantoms can be adjusted by changing the coefficients of the equations in use. The other group is the voxel phantoms, which are based on tomographic images of a real person such as CT, MR and serially sectioned color slice images from a cadaver. Obviously, the voxel phantoms represent the anatomical structures of a human body much more realistically than the stylized phantoms. A realistic representation of anatomical structure is very important for an accurate calculation of radiation dose in the human body. Consequently, the ICRP recently has decided to use the voxel phantoms for the forthcoming update of the dose conversion coefficients. However, the voxel phantoms also have some limitations: (1) The topology and dimensions of the organs and tissues in a voxel model are extremely difficult to change, and (2) The thin organs, such as oral mucosa and skin, cannot be realistically modeled unless the voxel resolution is prohibitively high. Recently, a new approach has been implemented by several investigators. The investigators converted their voxel phantoms to hybrid computational phantoms based on NURBS (Non-Uniform Rational B-Splines) surface, which is smooth and deformable. It is claimed that these new phantoms have the flexibility of the stylized phantom along with the realistic representations of the anatomical structures. The topology and dimensions of the anatomical structures can be easily changed as necessary. Thin organs can be modeled without affecting computational speed or memory requirement. The hybrid phantoms can be also used for 4-D Monte Carlo simulations. In this preliminary study, the external shape of a voxel phantom (i.e., skin), HDRK-Man, was converted to a hybrid computational

Dynamics of levitated nanospheres: towards the strong coupling regime

International Nuclear Information System (INIS)

Monteiro, T S; Millen, J; Pender, G A T; Barker, P F; Marquardt, Florian; Chang, D

2013-01-01

The use of levitated nanospheres represents a new paradigm for the optomechanical cooling of a small mechanical oscillator, with the prospect of realizing quantum oscillators with unprecedentedly high quality factors. We investigate the dynamics of this system, especially in the so-called self-trapping regime, where one or more optical fields simultaneously trap and cool the mechanical oscillator. The determining characteristic of this regime is that both the mechanical frequency ω M and single-photon optomechanical coupling strength parameters g are a function of the optical field intensities, in contrast to usual set-ups where ω M and g are constant for the given system. We also measure the characteristic transverse and axial trapping frequencies of different sized silica nanospheres in a simple optical standing wave potential, for spheres of radii r = 20–500 nm, illustrating a protocol for loading single nanospheres into a standing wave optical trap that would be formed by an optical cavity. We use these data to confirm the dependence of the effective optomechanical coupling strength on sphere radius for levitated nanospheres in an optical cavity and discuss the prospects for reaching regimes of strong light–matter coupling. Theoretical semiclassical and quantum displacement noise spectra show that for larger nanospheres with r ∼> 100 nm a range of interesting and novel dynamical regimes can be accessed. These include simultaneous hybridization of the two optical modes with the mechanical modes and parameter regimes where the system is bistable. We show that here, in contrast to typical single-optical mode optomechanical systems, bistabilities are independent of intracavity intensity and can occur for very weak laser driving amplitudes. (paper)

Effects of different hierarchical hybrid micro/nanostructure surfaces on implant osseointegration.

Science.gov (United States)

Cheng, Bingkun; Niu, Qiang; Cui, Yajun; Jiang, Wei; Zhao, Yunzhuan; Kong, Liang

2017-06-01

Hierarchical hybrid micro/nanostructure implant surfaces are considered to better mimic the hierarchical structure of bone and the nanostructures substantively influence osseointegration through managing cell behaviors. To enhance implant osseointegration for further clinical application, we evaluated the material properties and osseointegration effects of hierarchical surfaces with different nano-morphologies, using a rat model. Two representative surface fabrication methods, hydrofluoric (HF) acid etching combined with anodization (HF + AN) or magnetron sputtering (HF + MS), were selected. Sample material properties were evaluated by scanning electron microscopy, atomic force microscopy, X-ray diffraction, X-ray photoemission spectroscopy, and epoxy resin docking tensile test. Implants with different surfaces were inserted into the distal femurs of rats. After 12 weeks, osseointegration was examined by microcomputed tomography (micro-CT), histological, and biomechanical tests. Tensile testing demonstrated high bonding strength at coating/implant in the HF + MS group. Micro-CT revealed increased bone volume/total volume and significantly reduced trabecular separation in HF + MS versus other groups. Histological analysis showed significantly higher HF + MS bone-to-implant contact (74.78 ± 4.40%) versus HF + AN (65.11 ± 5.10%) and machined samples (56.03 ± 3.23%). The maximal HF + MS pull-out force increased by 33.7% versus HF + AN. These results indicated that HF + MS surfaces exhibited superior material property in terms of bonding strength and favorable implant osseointegration compared to other groups. © 2017 Wiley Periodicals, Inc.

Effects of Oriented Surface Dipole on Photoconversion Efficiency in an Alkane/Lipid-Hybrid-Bilayer-Based Photovoltaic Model System

KAUST Repository

Liu, Lixia

2013-06-21

When a phospholipid monolayer containing a zinc-coordinated porphyrin species formed atop a self-assembled monolayer of heptadecafluoro-1-decanethiol (CF3(CF2)7(CH2)2SH) is subjected to photoelectrochemical current generation, a significant modulation effect is observed. Compared with devices that contain similar photoactive lipid monolayers but formed on 1-dodecanethiol SAMs, these fluorinated hybrid bilayers produce a >60 % increase in cathodic currents and a similar decrease in anodic currents. Photovoltages recorded from these hybrid bilayers are found to vary in the same fashion. The modulation of photovoltaic responses in these hybrid-bilayer-based devices is explained by the opposite surface dipoles associated with the thiols employed in this study, which in one case (fluorothiol) increase and in another (alkanethiol) decrease the work function of the underlying gold substrates. A similar trend of photovoltage/photocurrent modulation is also observed if fullerene is used as the photoagent in these devices. Our results reveal the intricacy of orientated surface dipole in influencing the photovoltaic processes, and its subtle interplay with other factors related to the photoagents, such as their location and orientation within the organic matrix. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effects of Oriented Surface Dipole on Photoconversion Efficiency in an Alkane/Lipid-Hybrid-Bilayer-Based Photovoltaic Model System

KAUST Repository

Liu, Lixia; Xie, Hong; Bostic, Heidi E.; Jin, Limei; Best, Michael D.; Zhang, X. Peter; Zhan, Wei

2013-01-01

When a phospholipid monolayer containing a zinc-coordinated porphyrin species formed atop a self-assembled monolayer of heptadecafluoro-1-decanethiol (CF3(CF2)7(CH2)2SH) is subjected to photoelectrochemical current generation, a significant modulation effect is observed. Compared with devices that contain similar photoactive lipid monolayers but formed on 1-dodecanethiol SAMs, these fluorinated hybrid bilayers produce a >60 % increase in cathodic currents and a similar decrease in anodic currents. Photovoltages recorded from these hybrid bilayers are found to vary in the same fashion. The modulation of photovoltaic responses in these hybrid-bilayer-based devices is explained by the opposite surface dipoles associated with the thiols employed in this study, which in one case (fluorothiol) increase and in another (alkanethiol) decrease the work function of the underlying gold substrates. A similar trend of photovoltage/photocurrent modulation is also observed if fullerene is used as the photoagent in these devices. Our results reveal the intricacy of orientated surface dipole in influencing the photovoltaic processes, and its subtle interplay with other factors related to the photoagents, such as their location and orientation within the organic matrix. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Investigation of Steel Surfaces Treated by a Hybrid Ion Implantation Technique

International Nuclear Information System (INIS)

Reuther, H.; Richter, E.; Prokert, F.; Ueda, M.; Beloto, A. F.; Gomes, G. F.

2004-01-01

Implantation of nitrogen ions into stainless steel in combination with oxidation often results in a decrease or even complete removal of the chromium in the nitrogen containing outermost surface layer. While iron nitrides can be formed easily by this method, due to the absence of chromium, the formation of chromium nitrides is impossible and the beneficial influence of chromium in the steel for corrosion resistance cannot be used. To overcome this problem we use the following hybrid technique. A thin chromium layer is deposited on steel and subsequently implanted with nitrogen ions. Chromium can be implanted by recoil into the steel surface and thus the formation of iron/chromium nitrides should be possible. Both beam line ion implantation and plasma immersion ion implantation are used. Due to the variation of the process parameters, different implantation profiles and different compounds are produced. The produced layers are characterized by Auger electron spectroscopy, conversion electron Moessbauer spectroscopy and X-ray diffraction. The obtained results show that due to the variation of the implantation parameters, the formation of iron/chromium nitrides can be achieved and that plasma immersion ion implantation is the most suitable technique for the enrichment of chromium in the outermost surface layer of the steel when compared to the beam line implantation.

On the waterfall behavior in hybrid inflation

OpenAIRE

Kodama, Hideo; Kohri, Kazunori; Nakayama, Kazunori

2011-01-01

We revisit the hybrid inflation model focusing on the dynamics of the waterfall field in an analytical way. It is shown that inflation may last long enough during the waterfall regime for some parameter regions, confirming the claim of Clesse. In this case the scalar spectral index becomes red, and can fall into the best fit range of the WMAP observation.

Sputtering of Ge(001): transition between dynamic scaling regimes

DEFF Research Database (Denmark)

Smilgies, D.-M.; Eng, P.J.; Landemark, E.

1997-01-01

We have studied the dynamic behavior of the Ge(001) surface during sputtering in situ and in real time using synchrotron X-ray diffraction. We find two dynamic regimes as a function of surface temperature and sputter current which are separated by a sharp transition. The boundary between these two...

Mixed oxidizer hybrid propulsion system optimization under uncertainty using applied response surface methodology and Monte Carlo simulation

Science.gov (United States)

Whitehead, James Joshua

The analysis documented herein provides an integrated approach for the conduct of optimization under uncertainty (OUU) using Monte Carlo Simulation (MCS) techniques coupled with response surface-based methods for characterization of mixture-dependent variables. This novel methodology provides an innovative means of conducting optimization studies under uncertainty in propulsion system design. Analytic inputs are based upon empirical regression rate information obtained from design of experiments (DOE) mixture studies utilizing a mixed oxidizer hybrid rocket concept. Hybrid fuel regression rate was selected as the target response variable for optimization under uncertainty, with maximization of regression rate chosen as the driving objective. Characteristic operational conditions and propellant mixture compositions from experimental efforts conducted during previous foundational work were combined with elemental uncertainty estimates as input variables. Response surfaces for mixture-dependent variables and their associated uncertainty levels were developed using quadratic response equations incorporating single and two-factor interactions. These analysis inputs, response surface equations and associated uncertainty contributions were applied to a probabilistic MCS to develop dispersed regression rates as a function of operational and mixture input conditions within design space. Illustrative case scenarios were developed and assessed using this analytic approach including fully and partially constrained operational condition sets over all of design mixture space. In addition, optimization sets were performed across an operationally representative region in operational space and across all investigated mixture combinations. These scenarios were selected as representative examples relevant to propulsion system optimization, particularly for hybrid and solid rocket platforms. Ternary diagrams, including contour and surface plots, were developed and utilized to aid in

Multi-Fluid Modeling of Low-Recycling Divertor Regimes

International Nuclear Information System (INIS)

Smirnov, R.D.; Pigarov, A.Y.; Krasheninnikov, S.I.; Rognlien, T.D.; Soukhanovskii, V.A.; Rensink, M.E.; Maingi, R.; Skinner, C.H.; Stotler, D.P.; Bell, R.E.; Kugel, H.W.

2010-01-01

The low-recycling regimes of divertor operation in a single-null NSTX magnetic configuration are studied using computer simulations with the edge plasma transport code UEDGE. The edge plasma transport properties pertinent to the low-recycling regimes are demonstrated. These include the flux-limited character of the parallel heat transport and the high plasma temperatures with the flattened profiles in the scrape-off-layer. It is shown that to maintain the balance of particle fluxes at the core interface the deuterium gas puffing rate should increase as the divertor recycling coefficient decreases. The radial profiles of the heat load to the outer divertor plate, the upstream radial plasma profiles, and the effects of the cross-field plasma transport in the low-recycling regimes are discussed. It is also shown that recycling of lithium impurities evaporating from the divertor plate at high surface temperatures can reverse the low-recycling divertor operational regime to the high-recycling one and may cause thermal instability of the divertor plate.

Extraordinary Magnetic Field Enhancement with Metallic Nanowire: Role of Surface Impedance in Babinet's Principle for Sub-Skin-Depth Regime

Science.gov (United States)

Koo, Sukmo; Kumar, M. Sathish; Shin, Jonghwa; Kim, Daisik; Park, Namkyoo

2009-12-01

We propose and analyze the “complementary” structure of a metallic nanogap, namely, the metallic nanowire for magnetic field enhancement. A huge enhancement of the field up to a factor of 300 was achieved. Introducing the surface impedance concept, we also develop and numerically confirm a new analytic theory which successfully predicts the field enhancement factors for metal nanostructures. Compared to the predictions of the classical Babinet principle applied to a nanogap, an order of magnitude difference in the field enhancement factor was observed for the sub-skin-depth regime nanowire.

MHD stability analysis of axisymmetric surface current model tokamaks close to the spheromak regime

International Nuclear Information System (INIS)

Honma, Toshihisa; Kaji, Ikuo; Fukai, Ichiro; Kito, Masafumi.

1984-01-01

In the toroidal coordinates, a stability analysis is presented for very low-aspect-ratio tokamaks with circular cross section which is described by a surface current model (SCM) of axisymmetric equilibria. The energy principle determining the stability of plasma is treated without any expansion of aspect ratio. Numerical results show that, owing to the occurrence of the non-axisymmetric (n=1) unstable modes, there exists no MHD-stable ideal SCM spheromak characterized by zero external toroidal vacuum field. Instead, a stable spheromak-type plasma which comes to the ideal SCM spheromak is provided by the configuration with a very weak external toroidal field. Close to the spheromak regime (1.0 1 aspect ratio< = 1.1), the minimum safety factor and the critical β-values increase mo notonically with aspect ratio decreasing from a large value, and curves of βsub(p) versus β in the marginal stability approach to an ideal SCM spheromak line βsub(p)=β. (author)

Electrokinetic acceleration of DNA hybridization in microsystems.

Science.gov (United States)

Lei, Kin Fong; Wang, Yun-Hsiang; Chen, Huai-Yi; Sun, Jia-Hong; Cheng, Ji-Yen

2015-06-01

In this work, electrokinetic acceleration of DNA hybridization was investigated by different combinations of frequencies and amplitudes of actuating electric signals. Because the frequencies from low to high can induce different kinds of electrokinetic forces, i.e., electroosmotic to electrothermal forces, this work provides an in-depth investigation of electrokinetic enhanced hybridization. Concentric circular Cr/Au microelectrodes of 350 µm in diameter were fabricated on a glass substrate and probe DNA was immobilized on the electrode surface. Target DNA labeled with fluorescent dyes suspending in solution was then applied to the electrode. Different electrokinetic forces were induced by the application of different electric signals to the circular microelectrodes. Local microfluidic vortexes were generated to increase the collision efficiency between the target DNA suspending in solution and probe DNA immobilized on the electrode surface. DNA hybridization on the electrode surface could be accelerated by the electrokinetic forces. The level of hybridization was represented by the fluorescent signal intensity ratio. Results revealed that such 5-min dynamic hybridization increased 4.5 fold of signal intensity ratio as compared to a 1-h static hybridization. Moreover, dynamic hybridization was found to have better differentiation ability between specific and non-specific target DNA. This study provides a strategy to accelerate DNA hybridization in microsystems. Copyright © 2015 Elsevier B.V. All rights reserved.

Using a hybrid model to predict solute transfer from initially saturated soil into surface runoff with controlled drainage water.

Science.gov (United States)

Tong, Juxiu; Hu, Bill X; Yang, Jinzhong; Zhu, Yan

2016-06-01

The mixing layer theory is not suitable for predicting solute transfer from initially saturated soil to surface runoff water under controlled drainage conditions. By coupling the mixing layer theory model with the numerical model Hydrus-1D, a hybrid solute transfer model has been proposed to predict soil solute transfer from an initially saturated soil into surface water, under controlled drainage water conditions. The model can also consider the increasing ponding water conditions on soil surface before surface runoff. The data of solute concentration in surface runoff and drainage water from a sand experiment is used as the reference experiment. The parameters for the water flow and solute transfer model and mixing layer depth under controlled drainage water condition are identified. Based on these identified parameters, the model is applied to another initially saturated sand experiment with constant and time-increasing mixing layer depth after surface runoff, under the controlled drainage water condition with lower drainage height at the bottom. The simulation results agree well with the observed data. Study results suggest that the hybrid model can accurately simulate the solute transfer from initially saturated soil into surface runoff under controlled drainage water condition. And it has been found that the prediction with increasing mixing layer depth is better than that with the constant one in the experiment with lower drainage condition. Since lower drainage condition and deeper ponded water depth result in later runoff start time, more solute sources in the mixing layer are needed for the surface water, and larger change rate results in the increasing mixing layer depth.

Flow regimes

International Nuclear Information System (INIS)

Kh'yuitt, G.

1980-01-01

An introduction into the problem of two-phase flows is presented. Flow regimes arizing in two-phase flows are described, and classification of these regimes is given. Structures of vertical and horizontal two-phase flows and a method of their identification using regime maps are considered. The limits of this method application are discussed. The flooding phenomena and phenomena of direction change (flow reversal) of the flow and interrelation of these phenomena as well as transitions from slug regime to churn one and from churn one to annular one in vertical flows are described. Problems of phase transitions and equilibrium are discussed. Flow regimes in tubes where evaporating liquid is running, are described [ru

Conceptual design study for a laser fusion hybrid

International Nuclear Information System (INIS)

Maniscalco, J.A.

1976-09-01

Lawrence Livermore Laboratory and Bechtel Corporation have been involved in a joint effort to conceptually design a laser fusion hybrid reactor. The design which has evolved is a depleted-uranium fueled fast-fission blanket which produces fissile plutonium and electricity. A major objective of the design study was to evaluate the feasibility of producing fissile fuel with laser fusion. This feasibility evaluation was carried out by analyzing the integrated engineering performance of the complete conceptual design and by identifying the required laser/pellet performance. The performance of the laser fusion hybrid has also been compared to a typical fast breeder reactor. The results show that the laser fusion hybrid produces enough fissile material to fuel more than six light water reactors (LWR's) of equivalent thermal power while operating in a regime which requires an order of magnitude less laser and pellet performance than pure laser fusion. In comparison to a fast breeder reactor the hybrid produces 10 times more fissile fuel. An economic analysis of the design shows that the cost of electricity in a combined hybrid-LWR scenario is insensitive to the capital cost of the hybrid, increasing by only 20 to 40 percent when the capital cost of the hybrid ranges from 2 to 3 times more than an LWR

Cloud regimes as phase transitions

Science.gov (United States)

Stechmann, Samuel; Hottovy, Scott

2017-11-01

Clouds are repeatedly identified as a leading source of uncertainty in future climate predictions. Of particular importance are stratocumulus clouds, which can appear as either (i) closed cells that reflect solar radiation back to space or (ii) open cells that allow solar radiation to reach the Earth's surface. Here we show that these clouds regimes - open versus closed cells - fit the paradigm of a phase transition. In addition, this paradigm characterizes pockets of open cells (POCs) as the interface between the open- and closed-cell regimes, and it identifies shallow cumulus clouds as a regime of higher variability. This behavior can be understood using an idealized model for the dynamics of atmospheric water as a stochastic diffusion process. Similar viewpoints of deep convection and self-organized criticality will also be discussed. With these new conceptual viewpoints, ideas from statistical mechanics could potentially be used for understanding uncertainties related to clouds in the climate system and climate predictions. The research of S.N.S. is partially supported by a Sloan Research Fellowship, ONR Young Investigator Award N00014-12-1-0744, and ONR MURI Grant N00014-12-1-0912.

Surface geometry of three packable and one hybrid composite after polishing.

Science.gov (United States)

Jung, Martin; Bruegger, Hilka; Klimek, Joachim

2003-01-01

This study evaluated the surface quality of four composite materials after polishing with six different polishing techniques. Eighty specimens were made using three packable composites (Definite/Degussa, SureFil/ Dentsply and Solitaire/Heraeus-Kulzer) and one hybrid composite (Herculite XRV/Kerr). Five specimens of each material were polished using flexible Sof-Lex discs. The remaining 75 specimens of each composite were prepared using three finishing protocols: a single 30 microm diamond (n = 25), two finishing diamonds (30/20 microm; n = 25) and a 30 microm diamond followed by a tungsten carbide finishing bur (n = 25). Final polishing of each of the three finishing groups was accomplished with SuperBuff, Diafix-oral, OneGloss, Astropol and HaWe Composite Polishers (n = 5, each). Surface roughness was evaluated quantitatively by laser-stylus profilometry. Average roughness (R(a)) was calculated; statistical analysis of the data was performed with two-way ANOVA and Scheffé post-hoc tests. The polished surfaces were examined qualitatively by SEM. The results showed significant effects on surface roughness from the different composites (p = 0.011) and polishing systems (p < 0.001). After polishing, the Solitaire surfaces (R(a) = 0.72 microm) were smoother than Definite (R(a) = 0.87 microm) and SureFil (R(a) = 0.89 microm) and significantly smoother than Herculite (R(a) = 0.92 microm; p = 0.011). Three of the polishing methods (SuperBuff, Diafix-oral and Astropol) achieved lower R(a)-values than Sof-Lex discs. The polishing quality of the one-step systems SuperBuff and Diafix-oral was strongly affected by the initial finishing protocol.

Fast pulsing dynamics of a vertical-cavity surface-emitting laser operating in the low-frequency fluctuation regime

International Nuclear Information System (INIS)

Sciamanna, M.; Rogister, F.; Megret, P.; Blondel, M.; Masoller, C.; Abraham, N. B.

2003-01-01

We analyze the dynamics of a vertical-cavity surface-emitting laser with optical feedback operating in the low-frequency fluctuation regime. By focusing on the fast pulsing dynamics, we show that the two linearly polarized modes of the laser exhibit two qualitatively different behaviors: they emit pulses in phase just after a power dropout and they emit pulses out of phase after the recovery process of the output power. As a consequence, two distinct statistical distributions of the fast pulsating total intensity are observed, either monotonically decaying from the noise level or peaked around the mean intensity value. We further show that gain self-saturation of the lasing transition strongly modifies the shape of the intensity distribution

Temperature oscillating regimes in Tore Supra diagnosed by MHD activity

International Nuclear Information System (INIS)

Maget, P.; Imbeaux, F.; Giruzzi, G.; Udintsev, V.S.; Huysmans, G.T.A.; Segui, J.-L.; Goniche, M.; Moreau, Ph.; Sabot, R.; Garbet, X.

2006-01-01

This paper describes what we can learn on the regimes of spontaneous electron temperature oscillations discovered in Tore Supra from the analysis of MHD activity. Since the first observations of this oscillating behaviour of plasma equilibrium, and its interpretation as a predator-prey system involving lower hybrid waves power deposition and electron confinement, analysis of MHD modes has confirmed the reality of safety factor profile oscillations. This points towards the importance of rational values of the safety factor in the transition to transport barriers in reversed magnetic shear plasmas

Hybrid Methods in Designing Sierpinski Gasket Antennas

Directory of Open Access Journals (Sweden)

Mudrik Alaydrus

2010-12-01

Full Text Available Sierpinki gasket antennas as example of fractal antennas show multiband characteristics. The computer simulation of Sierpinksi gasket monopole with finite ground needs prohibitively large computer memory and more computational time. Hybrid methods consist of surface integral equation method and physical optics or uniform geometrical theory of diffraction should alleviate this computational burdens. The so-called full hybridization of the different methods with modifying the incoming electromagnetic waves in case of hybrid method surface integral equation method and physical optics and modification of the Greens function for hybrid method surface integral equation method and uniform geometrical theory of diffraction plays the central role in the observation. Comparison between results of different methods are given and also measurements of three Sierpinksi gasket antennas. The multiband characteristics of the antennas still can be seen with some reduction and enhancement of resonances.

Hybrid strategies in nanolithography

Energy Technology Data Exchange (ETDEWEB)

Saavedra, Hector M; Mullen, Thomas J; Zhang Pengpeng; Dewey, Daniel C; Claridge, Shelley A; Weiss, Paul S [Department of Chemistry, The Pennsylvania State University, University Park, PA 16802 (United States)], E-mail: psw@cnsi.ucla.edu

2010-03-15

Hybrid nanoscale patterning strategies combine the registration and addressability of conventional lithographic techniques with the chemical and physical functionality enabled by intermolecular, electrostatic and/or biological interactions. This review aims to highlight and to provide a comprehensive description of recent developments in hybrid nanoscale patterning strategies that enhance existing lithographic techniques or can be used to fabricate functional chemical patterns that interact with their environment. These functional structures create new capabilities, such as the fabrication of physicochemical surfaces that can recognize and capture analytes from complex liquid or gaseous mixtures. The nanolithographic techniques we describe can be classified into three general areas: traditional lithography, soft lithography and scanning-probe lithography. The strengths and limitations of each hybrid patterning technique will be discussed, along with the current and potential applications of the resulting patterned, functional surfaces.

Hybrid SN/Monte Carlo research and results

International Nuclear Information System (INIS)

Baker, R.S.

1993-01-01

The neutral particle transport equation is solved by a hybrid method that iteratively couples regions where deterministic (S N ) and stochastic (Monte Carlo) methods are applied. The Monte Carlo and S N regions are fully coupled in the sense that no assumption is made about geometrical separation or decoupling. The hybrid Monte Carlo/S N method provides a new means of solving problems involving both optically thick and optically thin regions that neither Monte Carlo nor S N is well suited for by themselves. The hybrid method has been successfully applied to realistic shielding problems. The vectorized Monte Carlo algorithm in the hybrid method has been ported to the massively parallel architecture of the Connection Machine. Comparisons of performance on a vector machine (Cray Y-MP) and the Connection Machine (CM-2) show that significant speedups are obtainable for vectorized Monte Carlo algorithms on massively parallel machines, even when realistic problems requiring variance reduction are considered. However, the architecture of the Connection Machine does place some limitations on the regime in which the Monte Carlo algorithm may be expected to perform well

Theory of the Quantum Dot Hybrid Qubit

Science.gov (United States)

Friesen, Mark

2015-03-01

The quantum dot hybrid qubit, formed from three electrons in two quantum dots, combines the desirable features of charge qubits (fast manipulation) and spin qubits (long coherence times). The hybridized spin and charge states yield a unique energy spectrum with several useful properties, including two different operating regimes that are relatively immune to charge noise due to the presence of optimal working points or ``sweet spots.'' In this talk, I will describe dc and ac-driven gate operations of the quantum dot hybrid qubit. I will analyze improvements in the dephasing that are enabled by the sweet spots, and I will discuss the outlook for quantum hybrid qubits in terms of scalability. This work was supported in part by ARO (W911NF-12-0607), NSF (PHY-1104660), the USDOD, and the Intelligence Community Postdoctoral Research Fellowship Program. The views and conclusions contained in this presentation are those of the authors and should not be interpreted as representing the official policies or endorsements, either expressed or implied, of the US government.

Performance of two-lobe hole-entry hybrid journal bearing system under the combined influence of textured surface and couple stress lubricant

Science.gov (United States)

Khatri, Chandra B.; Sharma, Satish C.

2018-02-01

Textured surface in journal bearings is becoming an important area of investigation during the last few years. Surface textures have the shapes of micro-dimple with a small diameter and depth having order of magnitude of bearing clearance. This paper presents the influence of couple stress lubricant on the circular and non-circular hole-entry hybrid journal bearing system and reports the comparative study between the textured and non-textured circular/non-circular hybrid journal bearing system. The governing Reynolds equation has been modified for the couple stress lubricant flow in the clearance of bearing and journal. The FEM technique has been applied to solve the modified Reynolds equation together with restrictor flow equation. The numerically simulated results indicate that the influence of couple stress lubricant is significantly more in textured journal bearing than that of non-textured journal bearing. Further, it has been observed that the textured two-lobe (δ = 1.1) hybrid journal bearing lubricated with couple stress lubricant provides larger values of fluid film stiffness coefficients and stability threshold speed against other bearings studied in the present paper.

Structural properties and surface wettability of Cu-containing diamond-like carbon films prepared by a hybrid linear ion beam deposition technique

Energy Technology Data Exchange (ETDEWEB)

Guo, Peng; Sun, Lili; Li, Xiaowei [Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Xu, Sheng [Gao Hong Coating Technology Co., Ltd, Huzhou 313000 (China); Ke, Peiling [Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Wang, Aiying, E-mail: aywang@nimte.ac.cn [Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China)

2015-06-01

Cu-containing diamond-like carbon (Cu-DLC) films were deposited on Si/glass substrate by a hybrid ion beam deposition system. The Cu concentration (0.1–39.7 at.%) in the film was controlled by varying the sputtering current. The microstructure and composition of Cu-DLC films were investigated systematically. The surface topography, roughness and surface wettability of the films were also studied. Results indicated that with increasing the Cu concentration, the water contact angle of the films changed from 66.8° for pure carbon film to more than 104.4° for Cu-DLC films with Cu concentration larger than 24.4 at.%. In the hydrophilic region, the polar surface energy decreased from 30.54 mJ/m{sup 2} for pure carbon film to 2.48 mJ/m{sup 2} for the film with Cu 7.0 at.%. - Highlights: • Cu-containing diamond-like carbon (DLC) films were deposited by a hybrid ion beam system. • Cu-containing DLC films exhibited a wide range of water contact angle. • The water contact angles vary with the surface energies and surface roughness.

Storm event-scale nutrient attenuation in constructed wetlands experiencing a Mediterranean climate: A comparison of a surface flow and hybrid surface-subsurface flow system.

Science.gov (United States)

Adyel, Tanveer M; Oldham, Carolyn E; Hipsey, Matthew R

2017-11-15

Among different Water Sensitive Urban Design options, constructed wetlands (CWs) are used to protect and restore downstream water quality by attenuating nutrients generated by stormwater runoff. This research compared the nutrient attenuation ability during a diverse population of storm events of two CWs: (a) a hybrid CW with multiple alternating surface flow (SF) and laterite-based subsurface flow (SSF) compartments, and (b) a single stage SF CW. Within-storm variability, nutrient concentrations were assessed at 2 to 3-h intervals at both the main inlet and outlet of each CW. Dissolved oxygen concentrations of the surface waters were also monitored at 10-min intervals using high frequency in situ sensors. Nutrient loads into the CWs were observed to be higher when a high rainfall event occurred, particularly after longer antecedent dry conditions. Longer hydraulic retention times promoted higher attenuation at both sites. However, the relative extent of nutrient attenuation differed between the CW types; the mean total nitrogen (TN) attenuation in the hybrid and SF CW was 45 and 48%, respectively. The hybrid CW attenuated 67% total phosphorus (TP) loads on average, while the SF CW acted as a net TP source. Periodic storm events transitioned the lentic CW into a lotic CW and caused riparian zone saturation; it was therefore hypothesized that such saturation of organic matter rich-riparian zones led to release of TP in the system. The hybrid CW attenuated the released TP in the downstream laterite-based SSF compartments. Diel oxygen metabolism calculated before and after the storm events was found to be strongly correlated with water temperature, solar exposure and antecedent dry condition during the pre-storm conditions. Furthermore, the SF CW showed a significant relationship between overall nutrient load attenuation and the change in oxygen metabolism during the storm perturbation, suggesting oxygen variation could be a useful proxy indicator of CW function

Lower hybrid waves instability in a velocity–sheared inhomogenous ...

African Journals Online (AJOL)

An electrostatic linear kinetic analysis of velocity-sheared inhomogeneous charged dust streaming parallel to a magnetic field in plasma is presented. Excited mode and the growth rates are derived in the lower hybrid-like mode regime, with collisional effects included. In the case where the drift velocity u is very small the ...

Nanoscale Organic−Inorganic Hybrid Lubricants

KAUST Repository

Kim, Daniel

2011-03-15

Silica (SiO2) nanoparticles densely grafted with amphiphilic organic chains are used to create a family of organic-inorganic hybrid lubricants. Short sulfonate-functionalized alkylaryl chains covalently tethered to the particles form a dense corona brush that stabilizes them against aggregation. When these hybrid particles are dispersed in poly-α-olefin (PAO) oligomers, they form homogeneous nanocomposite fluids at both low and high particle loadings. By varying the volume fraction of the SiO2 nanostructures in the PAO nanocomposites, we show that exceptionally stable hybrid lubricants can be created and that their mechanical properties can be tuned to span the spectrum from simple liquids to complex gels. We further show that these hybrid lubricants simultaneously exhibit lower interfacial friction coefficients, enhanced wear and mechanical properties, and superior thermal stability in comparison with either PAO or its nanocomposites created at low nanoparticle loadings. Profilometry and energy dispersive X-ray spectroscopic analysis of the wear track show that the enhanced wear characteristics in PAO-SiO2 composite lubricants originate from two sources: localization of the SiO2 particles into the wear track and extension of the elastohydrodynamic lubrication regime to Sommerfeld numbers more than an order of magnitude larger than for PAO. © 2011 American Chemical Society.

Tribological Properties of Aluminum Alloy treated by Fine Particle Peening/DLC Hybrid Surface Modification

Directory of Open Access Journals (Sweden)

Nanbu H.

2010-06-01

Full Text Available In order to improve the adhesiveness of the DLC coating, Fine Particle Peening (FPP treatment was employed as pre-treatment of the DLC coating process. FPP treatment was performed using SiC shot particles, and then AA6061-T6 aluminum alloy was DLC-coated. A SiC-rich layer was formed around the surface of the aluminum alloy by the FPP treatment because small chips of shot particles were embedded into the substrate surface. Reciprocating sliding tests were conducted to measure the friction coefficients. While the DLC coated specimen without FPP treatment showed a sudden increase in friction coefficient at the early stage of the wear cycles, the FPP/DLC hybrid treated specimen maintained a low friction coefficient value during the test period. Further investigation revealed that the tribological properties of the substrate after the DLC coating were improved with an increase in the amount of Si at the surface.

An Examination of the Nature of Global MODIS Cloud Regimes

Science.gov (United States)

Oreopoulos, Lazaros; Cho, Nayeong; Lee, Dongmin; Kato, Seiji; Huffman, George J.

2014-01-01

We introduce global cloud regimes (previously also referred to as "weather states") derived from cloud retrievals that use measurements by the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument aboard the Aqua and Terra satellites. The regimes are obtained by applying clustering analysis on joint histograms of retrieved cloud top pressure and cloud optical thickness. By employing a compositing approach on data sets from satellites and other sources, we examine regime structural and thermodynamical characteristics. We establish that the MODIS cloud regimes tend to form in distinct dynamical and thermodynamical environments and have diverse profiles of cloud fraction and water content. When compositing radiative fluxes from the Clouds and the Earth's Radiant Energy System instrument and surface precipitation from the Global Precipitation Climatology Project, we find that regimes with a radiative warming effect on the atmosphere also produce the largest implied latent heat. Taken as a whole, the results of the study corroborate the usefulness of the cloud regime concept, reaffirm the fundamental nature of the regimes as appropriate building blocks for cloud system classification, clarify their association with standard cloud types, and underscore their distinct radiative and hydrological signatures.

Groundwater quality assessment for the Bear Creek Hydrogeologic Regime at the Y-12 Plant

International Nuclear Information System (INIS)

1992-08-01

This report contains an evaluation of the groundwater and surface-water quality data obtained during the 1991 calendar year at several management facilities associated with the US Department of Energy Y-12 Plant. These sites are southwest of the Y-12 plant complex within the Bear Creek Hydrogeologic Regime (BCHR) which is one of three regimes defined for the purposes of groundwater and surface-water quality monitoring. Section 2.0 of this report contains background information regarding groundwater monitoring at the waste-management sites located in the BCHR. An overview of the hydrogeologic system in the BCHR is provided in Section 3.0. A discussion of the interpretive assumptions used in evaluating the 1991 assessment data and detailed descriptions of groundwater and surface-water quality in the regime are presented in Section 4.0. Findings of the 1991 monitoring program are summarized in Section 5.0. Proposed modifications to the groundwater and surface-water quality monitoring program in the BCHR are presented

Hybrid viscous damper with filtered integral force feedback control

DEFF Research Database (Denmark)

Høgsberg, Jan; Brodersen, Mark L.

2016-01-01

In hybrid damper systems active control devices are usually introduced to enhance the performance of otherwise passive dampers. In the present paper a hybrid damper concept is comprised of a passive viscous damper placed in series with an active actuator and a force sensor. The actuator motion...... is controlled by a filtered integral force feedback strategy, where the main feature is the filter, which is designed to render a damper force that in a phase-plane representation operates in front of the corresponding damper velocity. It is demonstrated that in the specific parameter regime where the damper...

Solubility studies of inorganic–organic hybrid nanoparticle photoresists with different surface functional groups

KAUST Repository

Li, Li

2016-01-01

© 2016 The Royal Society of Chemistry. The solubility behavior of Hf and Zr based hybrid nanoparticles with different surface ligands in different concentrations of photoacid generator as potential EUV photoresists was investigated in detail. The nanoparticles regardless of core or ligand chemistry have a hydrodynamic diameter of 2-3 nm and a very narrow size distribution in organic solvents. The Hansen solubility parameters for nanoparticles functionalized with IBA and 2MBA have the highest contribution from the dispersion interaction than those with tDMA and MAA, which show more polar character. The nanoparticles functionalized with unsaturated surface ligands showed more apparent solubility changes after exposure to DUV than those with saturated ones. The solubility differences after exposure are more pronounced for films containing a higher amount of photoacid generator. The work reported here provides material selection criteria and processing strategies for the design of high performance EUV photoresists.

Superhydrophobic hybrid inorganic-organic thiol-ene surfaces fabricated via spray-deposition and photopolymerization.

Science.gov (United States)

Sparks, Bradley J; Hoff, Ethan F T; Xiong, Li; Goetz, James T; Patton, Derek L

2013-03-13

We report a simple and versatile method for the fabrication of superhydrophobic inorganic-organic thiol-ene coatings via sequential spray-deposition and photopolymerization under ambient conditions. The coatings are obtained by spray-deposition of UV-curable hybrid inorganic-organic thiol-ene resins consisting of pentaerythritol tetra(3-mercaptopropionate) (PETMP), triallyl isocyanurate (TTT), 2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane (TMTVSi), and hydrophobic fumed silica nanoparticles. The spray-deposition process and nanoparticle agglomeration/dispersion provide surfaces with hierarchical morphologies exhibiting both micro- and nanoscale roughness. The wetting behavior, dependent on the concentration of TMTVSi and hydrophobic silica nanoparticles, can be varied over a broad range to ultimately provide coatings with high static water contact angles (>150°), low contact angle hysteresis, and low roll off angles (spray-deposition and UV-cure process on a variety of substrate surfaces including glass, paper, stone, and cotton fabric.

Dynamics of baroclinic wave pattern in transition zones between different flow regimes

International Nuclear Information System (INIS)

Larcher, Thomas von; Egbers, Christoph

2005-01-01

Baroclinic waves, both steady and time-dependent, are studied experimentally in a differentially heated rotating cylindrical gap with a free surface, cooled from within. Water is used as working fluid. We focus especially on transition zones between different flow regimes, where complex flow pattern like mixed-mode states are found. The transition from steady wave regime to irregular flow is also of particular interest. The surface flow is observed with visualisation techniques. Velocity time series are measured with the optical laser-Doppler-velocimetry technique. Thermographic measurements are applied for temperature field visualisations

Effect of exchange correlation potential on dispersion properties of lower hybrid wave in degenerate plasma

Science.gov (United States)

Rimza, Tripti; Sharma, Prerana

2017-05-01

The dispersion properties of lower hybrid wave are studied in electron-iondegenerate plasma with exchange effect in non-relativistic regime. It is found that the combined effect of Bohm potential and exchange correlation potential significantly modifies the dispersion properties of lower hybrid wave. The graphical results explicitly show the influence of degeneracy pressure, Bohm force and exchange correlation potential on the frequency of the lower hybrid mode. Present work should be of relevance for the dense astrophysical environments like white dwarfs and for laboratory experiments.

Lower hybrid heating experiments in tokamaks: an overview

International Nuclear Information System (INIS)

Porkolab, M.

1985-10-01

Lower hybrid wave propagation theory relevant to heating fusion grade plasmas (tokamaks) is reviewed. A brief discussion of accessibility, absorption, and toroidal ray propagation is given. The main part of the paper reviews recent results in heating experiments on tokamaks. Both electron and ion heating regimes will be discussed. The prospects of heating to high temperatures in reactor grade plasmas will be evaluated

Hybrid composites

CSIR Research Space (South Africa)

Jacob John, Maya

2009-04-01

Full Text Available mixed short sisal/glass hybrid fibre reinforced low density polyethylene composites was investigated by Kalaprasad et al [25].Chemical surface modifications such as alkali, acetic anhydride, stearic acid, permanganate, maleic anhydride, silane...

The Thermal Regime Around Buried Submarine High-Voltage Cables

Science.gov (United States)

Emeana, C. J.; Dix, J.; Henstock, T.; Gernon, T.; Thompson, C.; Pilgrim, J.

2015-12-01

The expansion of offshore renewable energy infrastructure and the desire for "trans-continental shelf" power transmission, all require the use of submarine High Voltage (HV) cables. These cables have maximum operating surface temperatures of up to 70oC and are typically buried at depths of 1-2 m beneath the seabed, within the wide range of substrates found on the continental shelf. However, the thermal properties of near surface shelf sediments are poorly understood and this increases the uncertainty in determining the required cable current ratings, cable reliability and the potential effects on the sedimentary environments. We present temperature measurements from a 2D laboratory experiment, designed to represent a buried, submarine HV cable. We used a large (2.5 m-high) tank, filled with water-saturated ballotini and instrumented with 120 thermocouples, which measured the time-dependent 2D temperature distributions around the heat source. The experiments use a buried heat source to represent a series of realistic cable surface temperatures with the aim for identifying the thermal regimes generated within typical non-cohesive shelf sediments: coarse silt, fine sand and very coarse sand. The steady state heat flow regimes, and normalised and radial temperature distributions were assessed. Our results show that at temperatures up to 60°C above ambient, the thermal regimes are conductive for the coarse silt sediments and convective for the very coarse sand sediments even at 7°C above ambient. However, the heat flow pattern through the fine sand sediment shows a transition from conductive to convective heat flow at a temperature of approximately 20°C above ambient. These findings offer an important new understanding of the thermal regimes associated with submarine HV cables buried in different substrates and has huge impacts on cable ratings as the IEC 60287 standard only considers conductive heat flow as well as other potential near surface impacts.

Role of organic cations on hybrid halide perovskite CH3NH3PbI3 surfaces

Science.gov (United States)

Teng, Qiang; Shi, Ting-Ting; Tian, Ren-Yu; Yang, Xiao-Bao; Zhao, Yu-Jun

2018-02-01

Organic-inorganic hybrid halide perovskite CH3NH3PbI3 (MAPbI3) has received rapid progress in power conversion efficiency as promising photovoltaic materials, yet the surface structures and the role of MA cations are not well understood. In this work, we investigated the structural stability and electronic properties of (001) surface of cubic, (001) and (110) surfaces of tetragonal and orthorhombic phases of MAPbI3 with considering the orientation of MA cations, by density functional theory calculations. We demonstrate that the orientation of MA cations has profound consequences on the structural stability and the electronic properties of the surfaces, in contrast to the bulk phases. Compared with the MA-I terminated surfaces, the Pb-I2 terminated ones generally have smaller band gaps and the advantage to enable the photo-excited holes to transfer to the hole-transport materials in both tetragonal and orthorhombic phases. Overall, we suggest that the films with Pb-I2 terminated surfaces would prevail in high performance solar energy absorbers.

Synthesis and surface immobilization of antibacterial hybrid silver-poly(l-lactide) nanoparticles

Science.gov (United States)

Taheri, Shima; Baier, Grit; Majewski, Peter; Barton, Mary; Förch, Renate; Landfester, Katharina; Vasilev, Krasimir

2014-08-01

Infections associated with medical devices are a substantial healthcare problem. Consequently, there has been increasing research and technological efforts directed toward the development of coatings that are capable of preventing bacterial colonization of the device surface. Herein, we report on novel hybrid silver loaded poly(L-lactic acid) nanoparticles (PLLA-AgNPs) with narrowly distributed sizes (17 ± 3 nm) prepared using a combination of solvent evaporation and mini-emulsion technology. These particles were then immobilized onto solid surfaces premodified with a thin layer of allylamine plasma polymer (AApp). The antibacterial efficacy of the PLLA-AgNPs nanoparticles was studied in vitro against both gram-positive (Staphylococcus epidermidis) and gram-negative (Escherichia coli) bacteria. The minimal inhibitory concentration values against Staphylococcus epidermidis and Escherichia coli were 0.610 and 1.156 μg · mL-1, respectively. The capacity of the prepared coatings to prevent bacterial surface colonization was assessed in the presence of Staphylococcus epidermidis, which is a strong biofilm former that causes substantial problems with medical device associated infections. The level of inhibition of bacterial growth was 98%. The substrate independent nature and the high antibacterial efficacy of coatings presented in this study may offer new alternatives for antibacterial coatings for medical devices.

Synthesis and surface immobilization of antibacterial hybrid silver-poly(l-lactide) nanoparticles

International Nuclear Information System (INIS)

Taheri, Shima; Majewski, Peter; Vasilev, Krasimir; Baier, Grit; Landfester, Katharina; Barton, Mary; Förch, Renate

2014-01-01

Infections associated with medical devices are a substantial healthcare problem. Consequently, there has been increasing research and technological efforts directed toward the development of coatings that are capable of preventing bacterial colonization of the device surface. Herein, we report on novel hybrid silver loaded poly(L-lactic acid) nanoparticles (PLLA-AgNPs) with narrowly distributed sizes (17 ± 3 nm) prepared using a combination of solvent evaporation and mini-emulsion technology. These particles were then immobilized onto solid surfaces premodified with a thin layer of allylamine plasma polymer (AApp). The antibacterial efficacy of the PLLA-AgNPs nanoparticles was studied in vitro against both gram-positive (Staphylococcus epidermidis) and gram-negative (Escherichia coli) bacteria. The minimal inhibitory concentration values against Staphylococcus epidermidis and Escherichia coli were 0.610 and 1.156 μg · mL −1 , respectively. The capacity of the prepared coatings to prevent bacterial surface colonization was assessed in the presence of Staphylococcus epidermidis, which is a strong biofilm former that causes substantial problems with medical device associated infections. The level of inhibition of bacterial growth was 98%. The substrate independent nature and the high antibacterial efficacy of coatings presented in this study may offer new alternatives for antibacterial coatings for medical devices. (paper)

Conceptual design study for a laser fusion hybrid

International Nuclear Information System (INIS)

Maniscalco, J.A.

1976-01-01

Lawrence Livermore Laboratory and Bechtel Corporation have been involved in a joint effort to conceptually design a laser fusion hybrid reactor. The design which has evolved is a depleted-uranium fueled fast-fission blanket which produces fissile plutonium and electricity. A major objective of the design study was to evaluate the feasibility of producing fissile fuel with laser fusion. This feasibility evaluation was carried out by analyzing the integrated engineering performance of the complete conceptual design and by identifying the required laser/pellet performance. The performance of the laser fusion hybrid has also been compared to a typical fast breeder reactor. The results show that the laser fusion hybrid produces enough fissile material to fuel more than six light water reactors (LWRs) of equivalent thermal power while operating in a regime which requires an order of magnitude less laser and pellet performance than pure laser fusion. In comparison to a fast breeder reactor the hybrid produces 10 times more fissile fuel. An economic analysis of the design shows that the cost of electricity in a combined hybrid-LWR scenario increases by only 20 to 40 percent when the capital cost of the hybrid ranges from 2 to 3 times more than an LWR

Multi-fluid modeling of low-recycling divertor regimes

International Nuclear Information System (INIS)

Smirnov, R.D.; Pigarov, A.Yu.; Krasheninnikov, S.I.; Rognlien, T.D.; Soukhanovskii, V.A.; Rensink, M.E.; Maingi, R.; Skinner, C.H.; Stotler, D.P.; Bell, R.E.; Kugel, H.W.

2010-01-01

The low-recycling regimes of divertor operation in a single-null NSTX magnetic configuration are studied using computer simulations with the edge plasma transport code UEDGE. The edge plasma transport properties pertinent to the low-recycling regimes are demonstrated. These include the flux-limited character of the parallel heat transport and the high plasma temperatures with the flattened profiles in the scrape-off-layer. It is shown that to maintain the balance of particle fluxes at the core interface the deuterium gas puffing rate should increase as the divertor recycling coefficient decreases. The radial profiles of the heat load to the outer divertor plate, the upstream radial plasma profiles, and the effects of the cross-field plasma transport in the low-recycling regimes are discussed. It is also shown that recycling of lithium impurities evaporating from the divertor plate at high surface temperatures can reverse the low-recycling divertor operational regime to the high-recycling one and may cause thermal instability of the divertor plate (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Trickle/pulse flow regime transition in downflow packed tower involving foaming liquids

Directory of Open Access Journals (Sweden)

Sodhi Vijay

2012-01-01

Full Text Available The most of past studies in foaming trickle bed reactors aimed at the improvement of efficiency and operational parameters leads to high economic advantages. Conventionally most of the industries rely on frequently used gas continuous flow (GCF where operational output is satisfactory but not yields efficiently as in pulsing flow (PF and foaming pulsing flow (FPF. Hydrodynamic characteristics like regime transitions are significantly influenced by foaming nature of liquid as well as gas and liquid flow rates. This study’s aim was to demonstrate experimentally the effects of liquid flow rate, gas flow rates and liquid surface tension on regime transition. These parameters were analyzed for the air-aqueous Sodium Lauryl Sulphate and air-water systems. More than 240 experiments were done to obtain the transition boundary for trickle flow (GCF to foaming pulsing flow (PF/FPF by use excessive foaming 15-60 ppm surfactant compositions. The trickle to pulse flow transition appeared at lower gas and liquid flow rates with decrease in liquid surface tension. All experimental data had been collected and drawn in the form of four different transitional plots which are compared and drawn by using flow coordinates proposed by different researchers. A prominent decrease in dynamic liquid saturation was observed especially during regime transitional change. The reactor two phase pressure evident a sharp rise to verify the regime transition shift from GCF to PF/FPF. Present study reveals, the regime transition boundary significantly influenced by any change in hydrodynamic as well as physiochemical properties including surface tension.

Sb(III)-Imprinted Organic-Inorganic Hybrid Sorbent Prepared by Hydrothermal-Assisted Surface Imprinting Technique for Selective Adsorption of Sb(III)

Science.gov (United States)

Zhang, Dan; Zhao, Yue; Xu, Hong-Bo

2018-03-01

Sb(III)-imprinted organic-inorganic hybrid sorbent was prepared by hydrothermal-assisted surface imprinting technique and was characterized by Fourier transform infrared spectroscopy, scanning electron microscopy coupled to an energy dispersive spectrometer and N2 adsorption/desorption isotherms. Hydrothermal-assisted process can improve the selectivity of the Sb(III)-imprinted hybrid sorbent for Sb(III) due to stable control of temperature and pressure. The Sb(III)-imprinted hybrid sorbent IIS indicated higher selectivity for Sb(III), had high static adsorption capacity of 37.3 mg g-1 for Sb(III), displayed stable adsorption capacity in pH range from 4 to 8, reached an rapid adsorption equilibrium within 30 min. According to the correlation coefficient ( r 2 > 0.99), the experimental data fitted better the pseudo-second-order kinetic model and Langmuir equilibrium isotherm.

Hybrid simulations of Z-Pinches in support of wire array implosion experiments at NTF

International Nuclear Information System (INIS)

Sotnikov, Vladimir Isaakovich; Oliver, Bryan Velten; Ivanov, Vladimir V.; LePell, Paul David; Fedin, Dmitry; Kantsyrev, Victor Leonidovich; Coverdale, Christine Anne; Travnicek, P.; Deeney, Christopher; Hellinger, P.; Jones, B.; Leboeuf, J.N.; Cowan, Thomas E.; Safronova, Alla S.

2005-01-01

Three-dimensional hybrid simulation of a plasma current-carrying column reveal two different regimes of sausage and kink instability development. In the first regime, with small Hall parameter, development of instabilities leads to the appearance of large-scale axial perturbations and eventually to bending of the plasma column. In the second regime, with a four-times-larger Hall parameter, small-scale perturbations dominate and no bending of the plasma column is observed. Simulation results are compared with laser probing experimental data obtained during wire array implosions on the Zebra pulse power generator at the Nevada Terawatt Facility.

Antibacterial inorganic-organic hybrid coatings on stainless steel via consecutive surface-initiated atom transfer radical polymerization for biocorrosion prevention.

Science.gov (United States)

Yuan, S J; Pehkonen, S O; Ting, Y P; Neoh, K G; Kang, E T

2010-05-04

To enhance the corrosion resistance of stainless steel (SS) and to impart its surface with antibacterial functionality for inhibiting biofilm formation and biocorrosion, well-defined inorganic-organic hybrid coatings, consisting of a polysilsesquioxane inner layer and quaternized poly(2-(dimethyamino)ethyl methacrylate) (P(DMAEMA)) outer blocks, were prepared via successive surface-initiated atom transfer radical polymerization (ATRP) of 3-(trimethoxysilyl)propyl methacrylate (TMSPMA) and 2-(dimethylamino)ethyl methacrylate (DMAEMA). The cross-linked P(TMASPMA), or polysilsesquioxane, inner layer provided a durable and resistant coating to electrolytes. The pendant tertiary amino groups of the P(DMAEMA) outer block were quaternized with alkyl halide to produce a high concentration of quaternary ammonium groups with biocidal functionality. The so-synthesized inorganic-organic hybrid coatings on the SS substrates exhibited good anticorrosion and antibacterial effects and inhibited biocorrosion induced by sulfate-reducing bacteria (SRB) in seawater media, as revealed by antibacterial assay and electrochemical analyses, and they are potentially useful to steel-based equipment under harsh industrial and marine environments.

Human hybrid hybridoma

Energy Technology Data Exchange (ETDEWEB)

Tiebout, R.F.; van Boxtel-Oosterhof, F.; Stricker, E.A.M.; Zeijlemaker, W.P.

1987-11-15

Hybrid hybridomas are obtained by fusion of two cells, each producing its own antibody. Several authors have reported the construction of murine hybrid hybridomas with the aim to obtain bispecific monoclonal antibodies. The authors have investigated, in a model system, the feasibility of constructing a human hybrid hybridoma. They fused two monoclonal cell lines: an ouabain-sensitive and azaserine/hypoxanthine-resistant Epstein-Barr virus-transformed human cell line that produces an IgG1kappa antibody directed against tetanus toxiod and an azaserine/hypoxanthine-sensitive and ouabain-resistant human-mouse xenohybrid cell line that produces a human IgG1lambda antibody directed against hepatitis-B surface antigen. Hybrid hybridoma cells were selected in culture medium containing azaserine/hypoxanthine and ouabain. The hybrid nature of the secreted antibodies was analyzed by means of two antigen-specific immunoassay. The results show that it is possible, with the combined use of transformation and xenohybridization techniques, to construct human hybrid hybridomas that produce bispecific antibodies. Bispecific antibodies activity was measured by means of two radioimmunoassays.

Enhancing Optically Pumped Organic-Inorganic Hybrid Perovskite Amplified Spontaneous Emission via Compound Surface Plasmon Resonance

Directory of Open Access Journals (Sweden)

Xiaoyan Wu

2018-03-01

Full Text Available Organic-inorganic hybrid perovskite has attracted intensive attention from researchers as the gain medium in lasing devices. However, achieving electrically driven lasing remains a significant challenge. Modifying the devices’ structure to enhance the optically pumped amplified spontaneous emission (ASE is the key issue. In this work, gold nanoparticles (Au NPs are first doped into PEDOT: PSS buffer layer in a slab waveguide device structure: Quartz/PEDOT: PSS (with or w/o Au NPs/CH3NH3PbBr3. As a result, the facile device shows a significantly enhanced ASE intensity and a narrowed full width at half maximum. Based on experiments and theoretical simulation data, the improvement is mainly a result of the compound surface plasmon resonance, including simultaneous near- and far-field effects, both of which could increase the density of excitons excited state and accelerate the radiative decay process. This method is highly significant for the design and development and fabrication of high-performance organic-inorganic hybrid perovskite lasing diodes.

Water-chemical regime of a fast reactor ower complex

International Nuclear Information System (INIS)

Musikhin, R.N.; Piskunov, E.M.; Samarkin, A.A.; Yurchenko, D.S.

1983-01-01

Some peculiarities of water-chemical regime of a power compleX in Shevchenko are considered. The complex comprises a desalination unit, a gas-masout heating-and-power plant and the BN-350 reactor. The compleX is used for the production of electric and thermal energy and fresh water. The power complex peculiarity is the utilization of disalinated seawater in a technological cycle along with highly mineralized seawater with a total salt content of 13.5 g/l (for cooling) in heat exchanges. A regime of ammoniacal correction of feed water was used as a basic water-chemical regime in the initial period of the BN-350 steam generator operation. Deposits composed mainly of iron oxide slime were observed on steam generator surfaces during the operation under these conditions. A conclusion is made that the regime with chelating agent providing steam generator safe operation without chemical cleaning is the most expedient one

An Efficient Hybrid DSMC/MD Algorithm for Accurate Modeling of Micro Gas Flows

KAUST Repository

Liang, Tengfei

2013-01-01

Aiming at simulating micro gas flows with accurate boundary conditions, an efficient hybrid algorithmis developed by combining themolecular dynamics (MD) method with the direct simulationMonte Carlo (DSMC)method. The efficiency comes from the fact that theMD method is applied only within the gas-wall interaction layer, characterized by the cut-off distance of the gas-solid interaction potential, to resolve accurately the gas-wall interaction process, while the DSMC method is employed in the remaining portion of the flow field to efficiently simulate rarefied gas transport outside the gas-wall interaction layer. A unique feature about the present scheme is that the coupling between the two methods is realized by matching the molecular velocity distribution function at the DSMC/MD interface, hence there is no need for one-toone mapping between a MD gas molecule and a DSMC simulation particle. Further improvement in efficiency is achieved by taking advantage of gas rarefaction inside the gas-wall interaction layer and by employing the "smart-wall model" proposed by Barisik et al. The developed hybrid algorithm is validated on two classical benchmarks namely 1-D Fourier thermal problem and Couette shear flow problem. Both the accuracy and efficiency of the hybrid algorithm are discussed. As an application, the hybrid algorithm is employed to simulate thermal transpiration coefficient in the free-molecule regime for a system with atomically smooth surface. Result is utilized to validate the coefficients calculated from the pure DSMC simulation with Maxwell and Cercignani-Lampis gas-wall interaction models. ©c 2014 Global-Science Press.

Evading the Lyth bound in hybrid natural inflation

International Nuclear Information System (INIS)

Hebecker, A.; Kraus, S.C.; Westphal, Alexander

2013-05-01

Generically, the gravitational-wave or tensor-mode contribution to the primordial curvature spectrum of inflation is tiny if the field-range of the inflaton is much smaller than the Planck scale. We show that this pessimistic conclusion is naturally avoided in a rather broad class of small-field models. More specifically, we consider models where an axion-like shift symmetry keeps the inflaton potential flat (up to non-perturbative cosine-shaped modulations), but inflation nevertheless ends in a waterfall-regime, as is typical for hybrid inflation. In such hybrid natural inflation scenarios (examples are provided by Wilson line inflation and fluxbrane inflation), the slow-roll parameter ε can be sizable during an early period (relevant for the CMB spectrum). Subsequently, ε quickly becomes very small before the tachyonic instability eventually terminates the slow-roll regime. In this scenario, one naturally generates a considerable tensor-mode contribution in the curvature spectrum, collecting nevertheless the required amount of e-foldings during the final period of inflation. While non-observation of tensors by Planck is certainly not a problem, a discovery in the medium to long term future is realistic.

Evading the Lyth bound in hybrid natural inflation

Science.gov (United States)

Hebecker, A.; Kraus, S. C.; Westphal, A.

2013-12-01

Generically, the gravitational-wave or tensor-mode contribution to the primordial curvature spectrum of inflation is tiny if the field range of the inflaton is much smaller than the Planck scale. We show that this pessimistic conclusion is naturally avoided in a rather broad class of small-field models. More specifically, we consider models where an axionlike shift symmetry keeps the inflaton potential flat (up to nonperturbative cosine-shaped modulations), but inflation nevertheless ends in a waterfall regime, as is typical for hybrid inflation. In such hybrid natural inflation scenarios (examples are provided by Wilson line inflation and fluxbrane inflation), the slow-roll parameter ɛ can be sizable during an early period (relevant for the cosmic microwave background spectrum). Subsequently, ɛ quickly becomes very small before the tachyonic instability eventually terminates the slow-roll regime. In this scenario, one naturally generates a considerable tensor-mode contribution in the curvature spectrum, collecting nevertheless the required amount of e-foldings during the final period of inflation. While nonobservation of tensors by Planck is certainly not a problem, a discovery in the medium- to long-term future is realistic.

Evading the Lyth bound in hybrid natural inflation

Energy Technology Data Exchange (ETDEWEB)

Hebecker, A.; Kraus, S.C. [Heidelberg Univ. (Germany). Inst. fuer Theoretische Physik; Westphal, Alexander [Deutsches Elektronen-Synchrotron DESY, Hamburg (Germany). Theory Group

2013-05-15

Generically, the gravitational-wave or tensor-mode contribution to the primordial curvature spectrum of inflation is tiny if the field-range of the inflaton is much smaller than the Planck scale. We show that this pessimistic conclusion is naturally avoided in a rather broad class of small-field models. More specifically, we consider models where an axion-like shift symmetry keeps the inflaton potential flat (up to non-perturbative cosine-shaped modulations), but inflation nevertheless ends in a waterfall-regime, as is typical for hybrid inflation. In such hybrid natural inflation scenarios (examples are provided by Wilson line inflation and fluxbrane inflation), the slow-roll parameter {epsilon} can be sizable during an early period (relevant for the CMB spectrum). Subsequently, {epsilon} quickly becomes very small before the tachyonic instability eventually terminates the slow-roll regime. In this scenario, one naturally generates a considerable tensor-mode contribution in the curvature spectrum, collecting nevertheless the required amount of e-foldings during the final period of inflation. While non-observation of tensors by Planck is certainly not a problem, a discovery in the medium to long term future is realistic.

Stream flow regime of springs in the Mantiqueira Mountain Range region, Minas Gerais State

Directory of Open Access Journals (Sweden)

Alisson Souza de Oliveira

2014-09-01

Full Text Available The stream flow regime of four springs located in the Mantiqueira Mountain Range region (MG was evaluated and correlated to the respective recharge area, relief characteristics, land cover and physical and hydrologic soil characteristics. The streamflow regime was characterized by monitoring of discharges, calculating the surface runoff and specific discharge and by modeling the discharge over the recession period using the Maillet method. As all recharge areas have similar relief the effect of it on the streamflow was not possible to identify. Analysis included determining the effect of drainage area size, soil characteristics and land cover on the indicators of the streamflow regime. Size of the recharge area had a positive influence on the indicators mean discharge and surface runoff volume and on the regulation of the streamflow regime (springs L4 and L1. The spring under the smallest area of influence provided the worst results for the above mentioned indicators (spring L3. The effect of forest cover (natural and planted, associated with soil characteristics, was evidenced by the indicators surface runoff (in depth and specific yield, both independent of the recharge area size (springs L4 and L2. The interaction of area size, soil characteristics and forest cover (natural and planted provided the best results for all indicators of streamflow regime in the springs studied in the Mantiqueira Mountain Range (spring L4.

Hybrid localized waves supported by resonant anisotropic metasurfaces

DEFF Research Database (Denmark)

Bogdanov, A. A.; Yermakov, O. Y.; Ovcharenko, A. I.

2016-01-01

We study both theoretically and experimentally a new class of surface electromagnetic waves supported by resonant anisotropic metasurface. At certain frequency this type of metasurface demonstrates the topological transition from elliptical to hyperbolic regime.......We study both theoretically and experimentally a new class of surface electromagnetic waves supported by resonant anisotropic metasurface. At certain frequency this type of metasurface demonstrates the topological transition from elliptical to hyperbolic regime....

Flow over an obstruction with the generation of nonlinear waves on the free surface: Limiting regimes

International Nuclear Information System (INIS)

Maklakov, D.V.

1995-01-01

A numerical-analytic method of calculating a subcritical flow over an obstruction is proposed. This method is based on the identification of the asymptotics of the behavior of a wave train in unknown functions. The method makes it possible to calculate both steep and long waves. The effectiveness of the method is demonstrated for the problem of flow over a vortex. The concept of the limiting flow regime as a regime with the maximum value of the perturbation parameter for which steady flow still persists is introduced. Various types of the limiting regimes obtained in the calculations are analyzed

Hybridization effect on generation capability of an embedded CPA

Directory of Open Access Journals (Sweden)

M. Klach

2016-03-01

Full Text Available The purpose of this paper is to compare performances of two configurations of an embedded Claw Pole Alternator (CPA where the excitation winding is transferred to the stator side. These configurations are: the Simple Excited Automotive Alternator (SE2A and the Hybrid Excited Automotive Alternator (HE2A. Performed study is based on test at no-load and under load operation regimes, using Magnetic Equivalent Circuit (MEC models validated experimentally. It has been found that the hybrid Excited claw pole alternator provides higher performances, due to the increase of leakage flux through the integration of permanent magnets between adjacent rotor claws.

Hybrid Type II fuzzy system & data mining approach for surface finish

Directory of Open Access Journals (Sweden)

Tzu-Liang (Bill Tseng

2015-07-01

Full Text Available In this study, a new methodology in predicting a system output has been investigated by applying a data mining technique and a hybrid type II fuzzy system in CNC turning operations. The purpose was to generate a supplemental control function under the dynamic machining environment, where unforeseeable changes may occur frequently. Two different types of membership functions were developed for the fuzzy logic systems and also by combining the two types, a hybrid system was generated. Genetic algorithm was used for fuzzy adaptation in the control system. Fuzzy rules are automatically modified in the process of genetic algorithm training. The computational results showed that the hybrid system with a genetic adaptation generated a far better accuracy. The hybrid fuzzy system with genetic algorithm training demonstrated more effective prediction capability and a strong potential for the implementation into existing control functions.

Understanding the Effect of Surface Chemistry on Charge Generation and Transport in Poly (3-hexylthiophene)/CdSe Hybrid Solar Cells

DEFF Research Database (Denmark)

Lek, Jun Yan; Xi, Lifei; Kardynal, Beata

2011-01-01

For hybrid solar cells, interfacial chemistry is one of the most critical factors for good device performance. We have demonstrated that the size of the surface ligands and the dispersion of nanoparticles in the solvent and in the polymer are important criteria in obtaining optimized device...

Influence of electroformation regime on the specific properties of cobalt oxide‒platinum composite films deposited on conductive diamond

Energy Technology Data Exchange (ETDEWEB)

Spătaru, Tanţa; Osiceanu, Petre; Preda, Loredana; Munteanu, Cornel [Institute of Physical Chemistry “Ilie Murgulescu”, 202 Spl. Independenţei 060021, Bucharest (Romania); Spătaru, Nicolae, E-mail: nspataru@icf.ro [Institute of Physical Chemistry “Ilie Murgulescu”, 202 Spl. Independenţei 060021, Bucharest (Romania); Fujishima, Akira [Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku Tokyo 162-8601 (Japan)

2014-04-01

Two straightforward electrochemical methods were used in the present work for depositing cobalt oxide-platinum composite films on boron-doped diamond substrates in order to put into evidence the effect of the electroformation regime on the morphological and electrochemical features of these hybrid systems. The shift from potentiostatic to potentiodynamic deposition enabled not only a significant improvement of the Pt particles dispersion but also a much higher surface concentration of oxygenated species of platinum. For similar Co{sub 3}O{sub 4} and Pt loadings, the specific capacitance of the composite films deposited by cyclic voltammetry was with ca. 8% higher than that of the potentiostatically obtained ones. Additional advantage of potentiodynamic deposition is the improved resistance to fouling during methanol anodic oxidation of Pt particles, tentatively ascribed to the higher surface concentration of oxygenated species of platinum. - Highlights: • Cobalt oxide-platinum composite films were electrodeposited on conductive diamond. • Composite films formed by cyclic voltammetry exhibit enhanced specific capacitance. • Potentiodynamic deposition enables higher concentration of oxygenated Pt species. • Co{sub 3}O{sub 4}–Pt films prepared by cyclic voltammetry are less susceptible to CO poisoning.

Flow regimes

International Nuclear Information System (INIS)

Liles, D.R.

1982-01-01

Internal boundaries in multiphase flow greatly complicate fluid-dynamic and heat-transfer descriptions. Different flow regimes or topological configurations can have radically dissimilar interfacial and wall mass, momentum, and energy exchanges. To model the flow dynamics properly requires estimates of these rates. In this paper the common flow regimes for gas-liquid systems are defined and the techniques used to estimate the extent of a particular regime are described. Also, the current computer-code procedures are delineated and introduce a potentially better method is introduced

Delaying the waterfall transition in warm hybrid inflation

OpenAIRE

Bastero-Gil, Mar; Berera, Arjun; Metcalf, Thomas P.; Rosa, João G.

2014-01-01

We analyze the dynamics and observational predictions of supersymmetric hybrid inflation in the warm regime, where dissipative effects are mediated by the waterfall fields and their subsequent decay into light degrees of freedom. This produces a quasi-thermal radiation bath with a slowly-varying temperature during inflation and further damps the inflaton's motion, thus prolonging inflation. As in the standard supercooled scenario, inflation ends when the waterfall fields become tachyonic and ...

Cattaneo-Christov based study of {TiO}_2 -CuO/EG Casson hybrid nanofluid flow over a stretching surface with entropy generation

Science.gov (United States)

Jamshed, Wasim; Aziz, Asim

2018-06-01

In the present research, a simplified mathematical model is presented to study the heat transfer and entropy generation analysis of thermal system containing hybrid nanofluid. Nanofluid occupies the space over an infinite horizontal surface and the flow is induced by the non-linear stretching of surface. A uniform transverse magnetic field, Cattaneo-Christov heat flux model and thermal radiation effects are also included in the present study. The similarity technique is employed to reduce the governing non-linear partial differential equations to a set of ordinary differential equation. Keller Box numerical scheme is then used to approximate the solutions for the thermal analysis. Results are presented for conventional copper oxide-ethylene glycol (CuO-EG) and hybrid titanium-copper oxide/ethylene glycol ({TiO}_2 -CuO/EG) nanofluids. The spherical, hexahedron, tetrahedron, cylindrical, and lamina-shaped nanoparticles are considered in the present analysis. The significant findings of the study is the enhanced heat transfer capability of hybrid nanofluids over the conventional nanofluids, greatest heat transfer rate for the smallest value of the shape factor parameter and the increase in Reynolds number and Brinkman number increases the overall entropy of the system.

Silicon based quantum dot hybrid qubits

Science.gov (United States)

Kim, Dohun

2015-03-01

The charge and spin degrees of freedom of an electron constitute natural bases for constructing quantum two level systems, or qubits, in semiconductor quantum dots. The quantum dot charge qubit offers a simple architecture and high-speed operation, but generally suffers from fast dephasing due to strong coupling of the environment to the electron's charge. On the other hand, quantum dot spin qubits have demonstrated long coherence times, but their manipulation is often slower than desired for important future applications. This talk will present experimental progress of a `hybrid' qubit, formed by three electrons in a Si/SiGe double quantum dot, which combines desirable characteristics (speed and coherence) in the past found separately in qubits based on either charge or spin degrees of freedom. Using resonant microwaves, we first discuss qubit operations near the `sweet spot' for charge qubit operation. Along with fast (>GHz) manipulation rates for any rotation axis on the Bloch sphere, we implement two independent tomographic characterization schemes in the charge qubit regime: traditional quantum process tomography (QPT) and gate set tomography (GST). We also present resonant qubit operations of the hybrid qubit performed on the same device, DC pulsed gate operations of which were recently demonstrated. We demonstrate three-axis control and the implementation of dynamic decoupling pulse sequences. Performing QPT on the hybrid qubit, we show that AC gating yields π rotation process fidelities higher than 93% for X-axis and 96% for Z-axis rotations, which demonstrates efficient quantum control of semiconductor qubits using resonant microwaves. We discuss a path forward for achieving fidelities better than the threshold for quantum error correction using surface codes. This work was supported in part by ARO (W911NF-12-0607), NSF (PHY-1104660), DOE (DE-FG02-03ER46028), and by the Laboratory Directed Research and Development program at Sandia National Laboratories

Inorganic-organic hybrid coatings on stainless steel by layer-by-layer deposition and surface-initiated atom-transfer-radical polymerization for combating biocorrosion.

Science.gov (United States)

Yuan, S J; Pehkonen, S O; Ting, Y P; Neoh, K G; Kang, E T

2009-03-01

To improve the biocorrosion resistance of stainless steel (SS) and to confer the bactericidal function on its surface for inhibiting bacterial adhesion and biofilm formation, well-defined inorganic-organic hybrid coatings, consisting of the inner compact titanium oxide multilayers and outer dense poly(vinyl-N-hexylpyridinium) brushes, were successfully developed. Nanostructured titanium oxide multilayer coatings were first built up on the SS substrates via the layer-by-layer sol-gel deposition process. The trichlorosilane coupling agent, containing the alkyl halide atom-transfer-radical polymerization (ATRP) initiator, was subsequently immobilized on the titanium oxide coatings for surface-initiated ATRP of 4-vinylpyridine (4VP). The pyridium nitrogen moieties of the covalently immobilized 4VP polymer, or P(4VP), brushes were quaternized with hexyl bromide to produce a high concentration of quaternary ammonium salt on the SS surfaces. The excellent antibacterial efficiency of the grafted polycations, poly(vinyl-N-pyridinium bromide), was revealed by viable cell counts and atomic force microscopy images of the surface. The effectiveness of the hybrid coatings in corrosion protection was verified by the Tafel plot and electrochemical impedance spectroscopy measurements.

Multi-step surface functionalization of polyimide based evanescent wave photonic biosensors and application for DNA hybridization by Mach-Zehnder interferometer

Energy Technology Data Exchange (ETDEWEB)

Melnik, Eva [Health and Environment Department, Nano Systems, AIT Austrian Institute of Technology GmbH, Donau-City-Strasse 1, 1220 Vienna (Austria); Department of Analytical Chemistry, University of Vienna, Waehringer Strasse 38, 1090 Vienna (Austria); Bruck, Roman [Health and Environment Department, Nano Systems, AIT Austrian Institute of Technology GmbH, Donau-City-Strasse 1, 1220 Vienna (Austria); Hainberger, Rainer, E-mail: rainer.hainberger@ait.ac.at [Health and Environment Department, Nano Systems, AIT Austrian Institute of Technology GmbH, Donau-City-Strasse 1, 1220 Vienna (Austria); Laemmerhofer, Michael, E-mail: michael.laemmerhofer@univie.ac.at [Department of Analytical Chemistry, University of Vienna, Waehringer Strasse 38, 1090 Vienna (Austria)

2011-08-12

Highlights: {yields} We realize a biosensing platform for polyimide evanescent photonic wave sensors. {yields} We show that the surface functionalization via silanisation and biotinylation followed by streptavidin immobilization do not destroy or damage the thin polyimide film. {yields} A highly dense streptavidin layer enables the immobilisation of biotinylated ligands such as biotinylated ssDNA for the selective measurement of DNA hybridization. - Abstract: The process of surface functionalization involving silanization, biotinylation and streptavidin bonding as platform for biospecific ligand immobilization was optimized for thin film polyimide spin-coated silicon wafers, of which the polyimide film serves as a wave guiding layer in evanescent wave photonic biosensors. This type of optical sensors make great demands on the materials involved as well as on the layer properties, such as the optical quality, the layer thickness and the surface roughness. In this work we realized the binding of a 3-mercaptopropyl trimethoxysilane on an oxygen plasma activated polyimide surface followed by subsequent derivatization of the reactive thiol groups with maleimide-PEG{sub 2}-biotin and immobilization of streptavidin. The progress of the functionalization was monitored by using different fluorescence labels for optimization of the chemical derivatization steps. Further, X-ray photoelectron spectroscopy and atomic force microscopy were utilized for the characterization of the modified surface. These established analytical methods allowed to derive information like chemical composition of the surface, surface coverage with immobilized streptavidin, as well as parameters of the surface roughness. The proposed functionalization protocol furnished a surface density of 144 fmol mm{sup -2} streptavidin with good reproducibility (13.9% RSD, n = 10) and without inflicted damage to the surface. This surface modification was applied to polyimide based Mach-Zehnder interferometer

Flow regime classification in air-magnetic fluid two-phase flow.

Science.gov (United States)

Kuwahara, T; De Vuyst, F; Yamaguchi, H

2008-05-21

A new experimental/numerical technique of classification of flow regimes (flow patterns) in air-magnetic fluid two-phase flow is proposed in the present paper. The proposed technique utilizes the electromagnetic induction to obtain time-series signals of the electromotive force, allowing us to make a non-contact measurement. Firstly, an experiment is carried out to obtain the time-series signals in a vertical upward air-magnetic fluid two-phase flow. The signals obtained are first treated using two kinds of wavelet transforms. The data sets treated are then used as input vectors for an artificial neural network (ANN) with supervised training. In the present study, flow regimes are classified into bubbly, slug, churn and annular flows, which are generally the main flow regimes. To validate the flow regimes, a visualization experiment is also performed with a glycerin solution that has roughly the same physical properties, i.e., kinetic viscosity and surface tension, as a magnetic fluid used in the present study. The flow regimes from the visualization are used as targets in an ANN and also used in the estimation of the accuracy of the present method. As a result, ANNs using radial basis functions are shown to be the most appropriate for the present classification of flow regimes, leading to small classification errors.

Design of a hybrid emissivity domestic electric oven

Science.gov (United States)

Isik, Ozgur; Onbasioglu, Seyhan Uygur

2017-10-01

In this study, the radiative properties of the surfaces of an electric oven were investigated. Using experimental data related to an oven-like enclosure, a novel combination of surface properties was developed. Three different surface emissivity combinations were analysed experimentally: low-emissivity, high emissivity (black-coated), and hybrid emissivity. The term "hybrid emissivity design" here corresponds to an enclosure with some high emissive and some low-emissive surfaces. The experiments were carried out according to the EN 50304 standard. When a brick (load) was placed in the enclosure, the view factors between its surfaces were calculated with the Monte Carlo method. These and the measured surface temperatures were then used to calculate the radiative heat fluxes on the surfaces of the load. The three different models were compared with respect to energy consumption and baking time. The hybrid model performed best, with the highest radiative heat transfer between the surfaces of the enclosure and the load and minimum heat loss from the cavity. Thus, it was the most efficient model with the lowest energy consumption and the shortest baking time. The recent European Union regulation regarding the energy labelling of domestic ovens was used.

Enhanced non-radiative energy transfer in hybrid III-nitride structures

International Nuclear Information System (INIS)

Smith, R. M.; Athanasiou, M.; Bai, J.; Liu, B.; Wang, T.

2015-01-01

The effect of surface states has been investigated in hybrid organic/inorganic white light emitting structures that employ high efficiency, nearfield non-radiative energy transfer (NRET) coupling. The structures utilize blue emitting InGaN/GaN multiple quantum well (MQW) nanorod arrays to minimize the separation with a yellow emitting F8BT coating. Surface states due to the exposed III-nitride surfaces of the nanostructures are found to reduce the NRET coupling rate. The surface states are passivated by deposition of a silicon nitride layer on the III-nitride nanorod surface leading to reduced surface recombination. A low thickness surface passivation is shown to increase the NRET coupling rate by 4 times compared to an un-passivated hybrid structure. A model is proposed to explain the increased NRET rate for the passivated hybrid structures based on the reduction in surface electron depletion of the passivated InGaN/GaN MQW nanorods surfaces

Vegetation management with fire modifies peatland soil thermal regime.

Science.gov (United States)

Brown, Lee E; Palmer, Sheila M; Johnston, Kerrylyn; Holden, Joseph

2015-05-01

Vegetation removal with fire can alter the thermal regime of the land surface, leading to significant changes in biogeochemistry (e.g. carbon cycling) and soil hydrology. In the UK, large expanses of carbon-rich upland environments are managed to encourage increased abundance of red grouse (Lagopus lagopus scotica) by rotational burning of shrub vegetation. To date, though, there has not been any consideration of whether prescribed vegetation burning on peatlands modifies the thermal regime of the soil mass in the years after fire. In this study thermal regime was monitored across 12 burned peatland soil plots over an 18-month period, with the aim of (i) quantifying thermal dynamics between burned plots of different ages (from post burning), and (ii) developing statistical models to determine the magnitude of thermal change caused by vegetation management. Compared to plots burned 15 + years previously, plots recently burned (management effects. Temperatures measured in soil plots burned vegetation regrows. Our findings that prescribed peatland vegetation burning alters soil thermal regime should provide an impetus for further research to understand the consequences of thermal regime change for carbon processing and release, and hydrological processes, in these peatlands. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Surface modification of polyamide reverse osmosis membrane with organic-inorganic hybrid material for antifouling

Science.gov (United States)

Zhang, Yang; Wan, Ying; Pan, Guoyuan; Yan, Hao; Yao, Xuerong; Shi, Hongwei; Tang, Yujing; Wei, Xiangrong; Liu, Yiqun

2018-03-01

A series of thin-film composite reverse osmosis membranes based on polyamide have been modified by coating the polyvinyl alcohol and 3-mercaptopropyltriethoxysilane aqueous solution prepared by a sol-gel process on the membrane surface, followed by thermal crosslinking treatment. In order to improve the hydrophilicity of the modified TFC membranes, the membranes were then immersed into H2O2 aqueous solution to convert -SH into -SO3H. The resulting TFC membranes were characterized by SEM, AFM, ATR-FTIR, streaming potential, XPS as well as static contact angle. After surface modification with the organic-inorganic hybrid material, the TFC membranes show increased NaCl rejection and decreased water flux with increasing 3-mercaptopropyltrimethoxysilane content in coating solution. The optimal modification membrane (PA-SMPTES-0.8) exhibits a NaCl rejection of 99.29%, higher than that (97.20%) of the virgin PA membrane, and a comparable water flux to virgin PA membrane (41.7 L/m2 h vs 47.9 L/m2 h). More importantly, PA-SMPTES-0.8 membrane shows much more improved fouling resistance to BSA than virgin PA and PVA modified PA (PA-PVA-1.0) membranes. PA-SMPTES-0.8 membrane loses about 13% of the initial flux after BSA fouling for 12 h, which is lower than that of virgin PA and PA-PVA-1.0 membranes (42% and 18%). Furthermore, the flux recovery of PA-SMPTES-0.8 membrane reaches 94% after cleaning. Thus the TFC membranes modified by this organic-inorganic hybrid technology show potential applications as antifouling RO membrane for desalination and purification.

Flow regime and deposition pattern of evaporating binary mixture droplet suspended with particles.

Science.gov (United States)

Zhong, Xin; Duan, Fei

2016-02-01

The flow regimes and the deposition pattern have been investigated by changing the ethanol concentration in a water-based binary mixture droplet suspended with alumina nanoparticles. To visualize the flow patterns, Particle Image Velocimetry (PIV) has been applied in the binary liquid droplet containing the fluorescent microspheres. Three distinct flow regimes have been revealed in the evaporation. In Regime I, the vortices and chaotic flows are found to carry the particles to the liquid-vapor interface and to promote the formation of particle aggregation. The aggregates move inwards in Regime II as induced by the Marangoni flow along the droplet free surface. Regime III is dominated by the drying of the left water and the capillary flow driving particles radially outward is observed. The relative weightings of Regimes I and II, which are enhanced with an increasing load of ethanol, determine the motion of the nanoparticles and the formation of the final drying pattern.

Influence of field and geometric configurations on the mode conversion characteristics of hybrid waves in a magnetoplasma slab

Energy Technology Data Exchange (ETDEWEB)

Lee, Myoung-Jae [Department of Physics, Hanyang University, Seoul 04763 (Korea, Republic of); Research Institute for Natural Sciences, Hanyang University, Seoul 04763 (Korea, Republic of); Jung, Young-Dae, E-mail: ydjung@hanyang.ac.kr [Department of Applied Physics and Department of Bionanotechnology, Hanyang University, Ansan, Kyunggi-Do 15588 (Korea, Republic of); Department of Electrical and Computer Engineering, MC 0407, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0407 (United States)

2016-12-01

Highlights: • The mode conversion characteristics of hybrid surface waves are investigated in a magneto dusty plasma slab. • Upper- and lower-hybrid waves are found for the symmetric mode when the magnetic field is parallel to the slab surfaces. • The hybrid property of the surface waves disappears for the anti-symmetric mode. • The variations of the surface hybrid waves with the change of field and geometric configurations are also discussed. - Abstract: We explore the mode conversion characteristics of electrostatic hybrid surface waves due to the magnetic field orientation in a magnetoplasma slab. We obtain the dispersion relations for the symmetric and anti-symmetric modes of hybrid surface waves for two different magnetic field configurations: parallel and perpendicular. For the parallel magnetic field configuration, we have found that the symmetric mode propagates as upper- and lower-hybrid waves. However, the hybrid characteristics disappear and two non-hybrid waves are produced for the anti-symmetric mode. For the perpendicular magnetic field configuration, however, the anti-symmetric mode propagates as the upper- and lower-hybrid waves and the symmetric mode produces two non-hybrid branches of waves.

Influence of field and geometric configurations on the mode conversion characteristics of hybrid waves in a magnetoplasma slab

International Nuclear Information System (INIS)

Lee, Myoung-Jae; Jung, Young-Dae

2016-01-01

Highlights: • The mode conversion characteristics of hybrid surface waves are investigated in a magneto dusty plasma slab. • Upper- and lower-hybrid waves are found for the symmetric mode when the magnetic field is parallel to the slab surfaces. • The hybrid property of the surface waves disappears for the anti-symmetric mode. • The variations of the surface hybrid waves with the change of field and geometric configurations are also discussed. - Abstract: We explore the mode conversion characteristics of electrostatic hybrid surface waves due to the magnetic field orientation in a magnetoplasma slab. We obtain the dispersion relations for the symmetric and anti-symmetric modes of hybrid surface waves for two different magnetic field configurations: parallel and perpendicular. For the parallel magnetic field configuration, we have found that the symmetric mode propagates as upper- and lower-hybrid waves. However, the hybrid characteristics disappear and two non-hybrid waves are produced for the anti-symmetric mode. For the perpendicular magnetic field configuration, however, the anti-symmetric mode propagates as the upper- and lower-hybrid waves and the symmetric mode produces two non-hybrid branches of waves.

Two Regimes of Bandgap Red Shift and Partial Ambient Retention in Pressure-Treated Two-Dimensional Perovskites

Energy Technology Data Exchange (ETDEWEB)

Liu, Gang [Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, China; Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC 20015, United States; Kong, Lingping [Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, China; Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC 20015, United States; Guo, Peijun [Center; Stoumpos, Constantinos C. [Department; Hu, Qingyang [Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, China; Liu, Zhenxian [Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC 20015, United States; Cai, Zhonghou [Advanced; Gosztola, David J. [Center; Mao, Ho-kwang [Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, China; Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC 20015, United States; Kanatzidis, Mercouri G. [Department; Schaller, Richard D. [Center; Department

2017-10-09

The discovery of elevated environmental stability in two-dimensional (2D) Ruddlesden–Popper hybrid perovskites represents a significant advance in low-cost, high-efficiency light absorbers. In comparison to 3D counterparts, 2D perovskites of organo-lead-halides exhibit wider, quantum-confined optical bandgaps that reduce the wavelength range of light absorption. Here, we characterize the structural and optical properties of 2D hybrid perovskites as a function of hydrostatic pressure. We observe bandgap narrowing with pressure of 633 meV that is partially retained following pressure release due to an atomic reconfiguration mechanism. We identify two distinct regimes of compression dominated by the softer organic and less compressible inorganic sublattices. Our findings, which also include PL enhancement, correlate well with density functional theory calculations and establish structure–property relationships at the atomic scale. These concepts can be expanded into other hybrid perovskites and suggest that pressure/strain processing could offer a new route to improved materials-by-design in applications.

Effect of surface modification and hybridization on dynamic ...

Indian Academy of Sciences (India)

Storage and loss modulus values increased after treatments with simultaneous decrease in tan values. Roystonea regia and glass fibres were used together with varying proportions as reinforcement in epoxy matrix to study the hybridization effect on dynamic mechanical properties. Storage and loss modulus values ...

Surface Spectroscopy Center Of Excellence Project

Science.gov (United States)

Wooden, Diane

2014-01-01

We propose to develop a national center of excellence in Regolith Radiative Transfer (RRT), i.e., in modeling spectral reflectivity and emissivity of grainy or structured surfaces. The focus is the regime where the structural elements of grainy surfaces have grain sizes and separations of tens of microns, comparable to the wavelengths carrying diagnostic compositional information. This regime is of fundamental interest to remote sensing of planetary and terrestrial surfaces.

Field-emitting Townsend regime of surface dielectric barrier discharges emerging at high pressure up to supercritical conditions

International Nuclear Information System (INIS)

Pai, David Z; Stauss, Sven; Terashima, Kazuo

2015-01-01

Surface dielectric barrier discharges (DBDs) in CO 2 from atmospheric pressure up to supercritical conditions generated using 10 kHz ac excitation are investigated experimentally. Using current–voltage and charge–voltage measurements, imaging, optical emission spectroscopy, and spontaneous Raman spectroscopy, we identify and characterize a field-emitting Townsend discharge regime that emerges above 0.7 MPa. An electrical model enables the calculation of the discharge-induced capacitances of the plasma and the dielectric, as well as the space-averaged values of the surface potential and the potential drop across the discharge. The space-averaged Laplacian field is accounted for in the circuit model by including the capacitance due to the fringe electric field from the electrode edge. The electrical characteristics are demonstrated to fit the description of atmospheric-pressure Townsend DBDs (Naudé et al 2005 J. Phys. D: Appl. Phys. 38 530–8), i.e. self-sustained DBDs with minimal space-charge effects. The purely continuum emission spectrum is due to electron–neutral bremsstrahlung corresponding to an average electron temperature of 2600 K. Raman spectra of CO 2 near the critical point demonstrate that the average gas temperature increases by less than 1 K. (paper)

Pulse regime in formation of fractal fibers

Energy Technology Data Exchange (ETDEWEB)

Smirnov, B. M., E-mail: bmsmirnov@gmail.com [Joint Institute for High Temperatures (Russian Federation)

2016-11-15

The pulse regime of vaporization of a bulk metal located in a buffer gas is analyzed as a method of generation of metal atoms under the action of a plasma torch or a laser beam. Subsequently these atoms are transformed into solid nanoclusters, fractal aggregates and then into fractal fibers if the growth process proceeds in an external electric field. We are guided by metals in which transitions between s and d-electrons of their atoms are possible, since these metals are used as catalysts and filters in interaction with gas flows. The resistance of metal fractal structures to a gas flow is evaluated that allows one to find optimal parameters of a fractal structure for gas flow propagation through it. The thermal regime of interaction between a plasma pulse or a laser beam and a metal surface is analyzed. It is shown that the basic energy from an external source is consumed on a bulk metal heating, and the efficiency of atom evaporation from the metal surface, that is the ratio of energy fluxes for vaporization and heating, is 10{sup –3}–10{sup –4} for transient metals under consideration. A typical energy flux (~10{sup 6} W/cm{sup 2}), a typical surface temperature (~3000 K), and a typical pulse duration (~1 μs) provide a sufficient amount of evaporated atoms to generate fractal fibers such that each molecule of a gas flow collides with the skeleton of fractal fibers many times.

Virtual cathode regime in nonstationary electric high-current discharge in hydrogen

International Nuclear Information System (INIS)

Baksht, F.G.; Borodin, V.S.; Zhuravlev, V.N.

1988-01-01

Virtual cathode (VC) regime in a non-stationary high-current hydrogen arch is constructed. Basic calculational characteristics of the near-the-cathode layer are presented. The calculation was conducted for a 1 cm long cathode under 2x10 4 A/cm 2 current density in pulse and 10 atm. pressure. A rectangular current pulse was considered. It is shown that VC formation is caused by electron temperature reduction in the near-the-cathode area. This results in the reduction of ion flux from plasma to the cathode surface and finally in the change of a sign of space charge and field intensity near the surface. Under the transition to VC regime only the cathode temperature and its effective work function are practically changed, while the rest of parameters remain approximately constant

Surface characterization and biological evaluation of silver-incorporated DLC coatings fabricated by hybrid RF PACVD/MS method.

Science.gov (United States)

Bociąga, Dorota; Jakubowski, Witold; Komorowski, Piotr; Sobczyk-Guzenda, Anna; Jędrzejczak, Anna; Batory, Damian; Olejnik, Anna

2016-06-01

Since the biological response of the body towards an implanted material is mainly governed by its surface properties, biomaterials are improved by various kinds of coatings. Their role is to provide good mechanical and biological characteristics, and exclude some disadvantages like post-implantation infections. This phenomenon may be reduced by introduction of silver as an antibacterial agent. This study evaluates the Ag-DLC films synthesized by the hybrid RF PACVD/MS method according to the patent number PL401955-A1 worked out inter alia by the authors. Such tests as XPS, SEM, EDS, AFM, FTIR, Raman and ICP-TOF-MS were used to determine surface properties of the coatings. The obtained results were correlated with the biological response estimated on the basis of cells viability assay (osteoblast cells line Saos-2) and bacterial colonization test (Escherichia coli strain DH5α). Results showed that the hybrid RF PACVD/MS method allows one to get tight coating preventing the diffusion of harmful elements from the metallic substrate. Ag concentration increases with the growing power density, it occurs in metallic state, does not create chemical bonds and is evenly dispersed within the DLC matrix in the form of nanoscale silver clusters. Increasing silver content above 2at.% improves bactericidal properties, but decreases cell viability. Copyright © 2016 Elsevier B.V. All rights reserved.

Global gyrokinetic and fluid hybrid simulations of tokamaks and stellarators

Energy Technology Data Exchange (ETDEWEB)

Cole, Michael David John

2016-07-15

Achieving commercial production of electricity by magnetic confinement fusion requires improvements in energy and particle confinement. In order to better understand and optimise confinement, numerical simulations of plasma phenomena are useful. One particularly challenging regime is that in which long wavelength MHD phenomena interact with kinetic phenomena. In such a regime, global electromagnetic gyrokinetic simulations are necessary. In this regime, computational requirements have been excessive for Eulerian methods, while Particle-in-Cell (PIC) methods have been particularly badly affected by the 'cancellation problem', a numerical problem resulting from the structure of the electromagnetic gyrokinetic equations. A number of researchers have been working on mitigating this problem with some significant successes. Another alternative to mitigating the problem is to move to a hybrid system of fluid and gyrokinetic equations. At the expense of reducing the physical content of the numerical model, particularly electron kinetic physics, it is possible in this way to perform global electromagnetic PIC simulations retaining ion gyrokinetic effects but eliminating the cancellation problem. The focus of this work has been the implementation of two such hybrid models into the gyrokinetic code EUTERPE. The two models treat electrons and the entire bulk plasma respectively as a fluid. Both models are additionally capable of considering the self-consistent interaction of an energetic ion species, described gyrokinetically, with the perturbed fields. These two models have been successfully benchmarked in linear growth rate and frequency against other codes for a Toroidal Alfven Eigenmode (TAE) case in both the linear and non-linear regimes. The m=1 internal kink mode, which is particularly challenging in terms of the fully gyrokinetic cancellation problem, has also been successfully benchmarked using the hybrid models with the MHD eigenvalue code CKA. Non

Global gyrokinetic and fluid hybrid simulations of tokamaks and stellarators

International Nuclear Information System (INIS)

Cole, Michael David John

2016-01-01

Achieving commercial production of electricity by magnetic confinement fusion requires improvements in energy and particle confinement. In order to better understand and optimise confinement, numerical simulations of plasma phenomena are useful. One particularly challenging regime is that in which long wavelength MHD phenomena interact with kinetic phenomena. In such a regime, global electromagnetic gyrokinetic simulations are necessary. In this regime, computational requirements have been excessive for Eulerian methods, while Particle-in-Cell (PIC) methods have been particularly badly affected by the 'cancellation problem', a numerical problem resulting from the structure of the electromagnetic gyrokinetic equations. A number of researchers have been working on mitigating this problem with some significant successes. Another alternative to mitigating the problem is to move to a hybrid system of fluid and gyrokinetic equations. At the expense of reducing the physical content of the numerical model, particularly electron kinetic physics, it is possible in this way to perform global electromagnetic PIC simulations retaining ion gyrokinetic effects but eliminating the cancellation problem. The focus of this work has been the implementation of two such hybrid models into the gyrokinetic code EUTERPE. The two models treat electrons and the entire bulk plasma respectively as a fluid. Both models are additionally capable of considering the self-consistent interaction of an energetic ion species, described gyrokinetically, with the perturbed fields. These two models have been successfully benchmarked in linear growth rate and frequency against other codes for a Toroidal Alfven Eigenmode (TAE) case in both the linear and non-linear regimes. The m=1 internal kink mode, which is particularly challenging in terms of the fully gyrokinetic cancellation problem, has also been successfully benchmarked using the hybrid models with the MHD eigenvalue code CKA. Non-linear simulations

Simulations of enhanced reversed shear TFTR discharges with lower hybrid current drive

International Nuclear Information System (INIS)

Kesner, J.; Bateman, G.

1996-01-01

The BALDUR based BBK code permits predictive simulations of time-dependent tokamak discharges and has the capability to include neutral beam heating, pellet injection, bootstrap currents and lower hybrid current drive. BALDUR contains a theory based multi-regime transport model and previous work has shown excellent agreement with both L-mode and supershot TFTR discharges. These simulations reveal that core transport is dominated by η i and trapped electron modes and the outer region by resistive ballooning. We simulate enhanced reverse shear discharges by beginning with a supershot simulation with a reversed shear profile. Similarly to the TFTR experiments the reversed shear profile is obtained through the programming of the current during startup and the freezing in of these profiles by subsequent heating. At the time of transition into the enhanced confinement regime we turn off the η i and trapped-electron mode transport. We examine the further modification of the plasma current profile that can be obtained with the application of lower hybrid current drive. The results of these simulations will be discussed

Flutter analysis of hybrid metal-composite low aspect ratio trapezoidal wings in supersonic flow

Directory of Open Access Journals (Sweden)

Shokrollahi Saeed

2017-02-01

Full Text Available An effective 3D supersonic Mach box approach in combination with non-classical hybrid metal-composite plate theory has been used to investigate flutter boundaries of trapezoidal low aspect ratio wings. The wing structure is composed of two main components including aluminum material (in-board section and laminated composite material (out-board section. A global Ritz method is used with simple polynomials being employed as the trial functions. The most important objective of the present research is to study the effect of composite to metal proportion of hybrid wing structure on flutter boundaries in low supersonic regime. In addition, the effect of some important geometrical parameters such as sweep angle, taper ratio and aspect ratio on flutter boundaries were studied. The results obtained by present approach for special cases like pure metallic wings and results for high supersonic regime based on piston theory show a good agreement with those obtained by other investigators.

Multiple climate regimes in an idealized lake-ice-atmosphere model

Science.gov (United States)

Sugiyama, Noriyuki; Kravtsov, Sergey; Roebber, Paul

2018-01-01

In recent decades, the Laurentian Great Lakes have undergone rapid surface warming with the summertime trends substantially exceeding the warming rates of surrounding land. Warming of the deepest (Lake Superior) was the strongest, and that of the shallowest (Lake Erie)—the weakest of all lakes. To investigate the dynamics of accelerated lake warming, we considered single-column and multi-column thermodynamic lake-ice models coupled to an idealized two-layer atmosphere. The variable temperature of the upper atmospheric layer—a proxy for the large-scale atmospheric forcing—consisted, in the most general case, of a linear trend mimicking the global warming and atmospheric interannual variability, both on top of the prescribed seasonal cycle of the upper-air temperature. The atmospheric boundary layer of the coupled model exchanged heat with the lake and exhibited lateral diffusive heat transports between the adjacent atmospheric columns. In simpler single-column models, we find that, for a certain range of periodic atmospheric forcing, each lake possesses two stable equilibrium seasonal cycles, which we call "regimes"—with and without lake-ice occurrence in winter and with corresponding cold and warm temperatures in the following summer, respectively, all under an identical seasonally varying external forcing. Deeper lakes exhibit larger differences in their summertime surface water temperature between the warm and cold regimes, due to their larger thermal and dynamical inertia. The regime behavior of multi-column coupled models is similar but more complex, and in some cases, they admit more than two stable equilibrium seasonal cycles, with varying degrees of wintertime ice-cover. The simulated lake response to climate change in the presence of the atmospheric noise rationalizes the observed accelerated warming of the lakes, the correlation between wintertime ice cover and next summer's lake-surface temperature, as well as higher warming trends of the

Multi-response optimization of surface integrity characteristics of EDM process using grey-fuzzy logic-based hybrid approach

Directory of Open Access Journals (Sweden)

Shailesh Dewangan

2015-09-01

Full Text Available Surface integrity remains one of the major areas of concern in electric discharge machining (EDM. During the current study, grey-fuzzy logic-based hybrid optimization technique is utilized to determine the optimal settings of EDM process parameters with an aim to improve surface integrity aspects after EDM of AISI P20 tool steel. The experiment is designed using response surface methodology (RSM considering discharge current (Ip, pulse-on time (Ton, tool-work time (Tw and tool-lift time (Tup as process parameters. Various surface integrity characteristics such as white layer thickness (WLT, surface crack density (SCD and surface roughness (SR are considered during the current research work. Grey relational analysis (GRA combined with fuzzy-logic is used to determine grey fuzzy reasoning grade (GFRG. The optimal solution based on this analysis is found to be Ip = 1 A, Ton = 10 μs, Tw = 0.2 s, and Tup = 0.0 s. Analysis of variance (ANOVA results clearly indicate that Ton is the most contributing parameter followed by Ip, for multiple performance characteristics of surface integrity.

Spray characteristics and spray cooling heat transfer in the non-boiling regime

International Nuclear Information System (INIS)

Cheng, Wen-Long; Han, Feng-Yun; Liu, Qi-Nie; Fan, Han-Lin

2011-01-01

Spray cooling is an effective method for dissipating high heat fluxes in the field of electronics thermal control. In this study, experiments were performed with distilled water as a test liquid to study the spray cooling heat transfer in non-boiling regime. A Phase Doppler Anemometry (PDA) was used to study the spray characteristics. The effects of spray flow rate, spray height, and inlet temperature on spray cooling heat transfer were investigated. It was found that the parameters affect heat transfer of spray cooling in non-boiling regime by the spray characteristics and working fluid thermophysical properties. Then the corresponding droplet axial velocity and Sauter mean diameter (SMD) were successfully correlated with mean absolute error of 15%, which were based upon the orifice diameter, the Weber and Reynolds numbers of the orifice flow prior to liquid breakup, dimensionless spray height and spray cross-section radius. The heat transfer in non-boiling regime was correlated with a mean absolute error of 7%, which was mainly associated with the working fluid thermophysical properties, the Weber and Reynolds numbers hitting the heating surface, dimensionless heating surface temperature and diameter. -- Highlights: → The spray flow rate, spray height, and inlet temperature affect heat transfer of spray cooling in non-boiling regime by the spray characteristics and the working fluid thermophysical properties. → Then the corresponding droplet axial velocity and Sauer mean diameter (SMD) were successfully correlated with mean absolute error of 15%. → The heat transfer in non-boiling regime was correlated with a mean absolute error of 7%.

Groundwater Protection Program Calendar Year 1998 Evaluation of Groundwater and Surface Water Quality Data for the Bear Creek Hydrogeologic Regime at the U.S. Department of Energy Y-12 Plant, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

None

1999-01-01

This report presents an evaluation of the water quality monitoring data obtained by the Y-12 Plant Groundwater Protection Program (GWPP) in the Bear Creek Hydrogeologic Regime (Bear Creek Regime) during calendar year (CY) 1998. The Bear Creek Regime contains many confirmed and potential sources of groundwater and surface water contamination associated with the U.S. Department of Energy (DOE) Oak Ridge Y-12 Plant. Applicable provisions of DOE Order 5400.1A - General Environmental Protection Program - require evaluation of groundwater and surface water quality near the Y-12 Plant to: (1) gauge groundwater quality in areas that are, or could be, affected by plant operations, (2) determine the quality of surface water and groundwater where contaminants are most likely to migrate beyond the DOE Oak Ridge Reservation (ORR) property line, and (3) identify and characterize long-term trends in groundwater quality. The following sections of this report contain relevant background information (Section 2.0); describe the results of the respective data evaluations required under DOE Order 5400.1A (Section 3.0); summarize significant findings of each evaluation (Section 4.0); and list the technical reports and regulatory documents cited for more detailed information (Section 5.0). All of the figures (maps and trend graphs) and data tables referenced in each section are presented in Appendix A and Appendix B, respectively

Groundwater Protection Program Calendar Year 1998 Evaluation of Groundwater and Surface Water Quality Data for the Bear Creek Hydrogeologic Regime at the U.S. Department of Energy Y-12 Plant, Oak Ridge, Tennessee

Energy Technology Data Exchange (ETDEWEB)

None

1999-09-01

This report presents an evaluation of the water quality monitoring data obtained by the Y-12 Plant Groundwater Protection Program (GWPP) in the Bear Creek Hydrogeologic Regime (Bear Creek Regime) during calendar year (CY) 1998. The Bear Creek Regime contains many confirmed and potential sources of groundwater and surface water contamination associated with the U.S. Department of Energy (DOE) Oak Ridge Y-12 Plant. Applicable provisions of DOE Order 5400.1A - General Environmental Protection Program - require evaluation of groundwater and surface water quality near the Y-12 Plant to: (1) gauge groundwater quality in areas that are, or could be, affected by plant operations, (2) determine the quality of surface water and groundwater where contaminants are most likely to migrate beyond the DOE Oak Ridge Reservation (ORR) property line, and (3) identify and characterize long-term trends in groundwater quality. The following sections of this report contain relevant background information (Section 2.0); describe the results of the respective data evaluations required under DOE Order 5400.1A (Section 3.0); summarize significant findings of each evaluation (Section 4.0); and list the technical reports and regulatory documents cited for more detailed information (Section 5.0). All of the figures (maps and trend graphs) and data tables referenced in each section are presented in Appendix A and Appendix B, respectively.

Effect of Surface Morphology and Dispersion Media on the Properties of PEDOT:PSS/n-Si Hybrid Solar Cell Containing Functionalized Graphene

Directory of Open Access Journals (Sweden)

Pham Van Trinh

2017-01-01

Full Text Available We present the results on the effect of surface morphology and dispersion media on the properties of PEDOT:PSS/n-Si hybrid solar cell containing functionalized graphene (Gr. The hybrid solar cells based on SiNWs showed higher power conversion efficiency (PCE compared to the planar based cells due to suppressing the carrier recombination and improving carrier transport efficiency. The PCE of hybrid solar cells could be improved by adding Gr into PEDOT:PSS. Different solvents including deionized (DI water, ethylene glycol (EG, and isopropyl alcohol (IPA were used as media for Gr dispersion. The best performance was obtained for the cell containing Gr dispersed in EG with a measured PCE of 7.33% and nearly 13% and 16% enhancement in comparison with the cells using Gr dispersed in IPA and DI water, respectively. The increase in PCE is attributed to improving the carrier-mobility, electrical conductivity, PEDOT crystallinity, and ordering.

A universal order underlying the pseudogap regime of the underdoped high Tc cuprates

Science.gov (United States)

Harrison, Neil

2014-03-01

A major achievement in condensed matter physics in the last quarter century has been a step towards the understanding of the unconventional d-wave superconducting state in the copper-oxide materials. Surprisingly, the normal state out of which the superconducting state emerges remains a mystery at low charge carrier densities, i.e., in the underdoped regime. This regime is of particular interest because it is characterised by an unusual momentum dependent energy pseudogap in the excitation spectrum that has defied explanation and is key to a full understanding of the unconventional d-wave superconducting state. I will present new quantum oscillation experimental results within the pseudogap regime of the high Tc superconductors YBa2Cu3O6+x and YBa2Cu4O8 which now extend up to the optimally-doped regime. These data reveal the evolution of the Fermi surface approaching the putative quantum critical point under the superconducting dome. A comprehensive angle-resolved study of the Fermi surface enables us to unambiguously identify a specific form of order that accounts for the observed quantum oscillations as well as other spectroscopic, transport and thermodynamic probes within the pseudogap regime. The author would like to thank B. Ramshaw, S. Sebastian, F. Balakirev, C. Mielke, M. Altarawneh, P. Goddard, S. Sabok, B. Babrowski, D. Bonn, W. Hardy, R. Liang and G. Lonzarich. This work was supported by the DOE BES ``Science of 100 tesla'' project and by the NSF and Florida State.

Biomolecular hybrid material and process for preparing same and uses for same

Science.gov (United States)

Kim, Jungbae [Richland, WA

2010-11-23

Disclosed is a composition and method for fabricating novel hybrid materials comprised of, e.g., carbon nanotubes (CNTs) and crosslinked enzyme clusters (CECs). In one method, enzyme-CNT hybrids are prepared by precipitation of enzymes which are subsequently crosslinked, yielding crosslinked enzyme clusters (CECs) on the surface of the CNTs. The CEC-enzyme-CNT hybrids exhibit high activity per unit area or mass as well as improved enzyme stability and longevity over hybrid materials known in the art. The CECs in the disclosed materials permit multilayer biocatalytic coatings to be applied to surfaces providing hybrid materials suitable for use in, e.g., biocatalytic applications and devices as described herein.

Competing fiscal regimes and incentives in the developing world

International Nuclear Information System (INIS)

Meurs, P. van

1991-01-01

The new order in the former Communist countries, the growth of deregulation and trade liberalization, and the opening up of formerly closed countries to outside investment have worked to increase the available exploratory acreage for the oil and gas industry. It is estimated that the total amount of this acreage available in the 1990s is about twice what it was in the 1970s. This is accompanied by an apparent trend toward lower government takes and better terms as governments are forced to compete with one another to attract investment. A particular trend is noted among governments to improve terms and conditions for what are internationally called small fields (those in the 10-30 million bbl class) and in deep water or other marginal conditions. Factors to be taken into account in evaluating the potential profitability of an investment in a developing country are discussed. Various types of fiscal systems are considered, including regressive regimes involving royalties and rentals, progressive features such as sliding royalties and taxes which increase as the field becomes more profitable, hybrid systems, and specialty incentives. Examples are presented to illustrate analyses of different fiscal regimes and the economic risk involved in an oil production investment. 6 tabs

Importance of surface structure on dissolution of fluorite

DEFF Research Database (Denmark)

Godinho, Jose; Piazolo, Sandra; Balic Zunic, Tonci

2014-01-01

forming the initial surface and its inclination to the closest stable planes, which are specific for each surface orientation. During an initial dissolution regime dissolution rates decrease significantly, even though the total surface area increases. During a second dissolution regime, some surfaces...... by the relative stability of the planes and type of edges that constitute a surface needs to be considered. Significant differences between dissolution rates calculated based on surface area alone, and based on surface reactivity are expected for materials with the fluorite structure....

Mixed DNA/Oligo(ethylene glycol) Functionalized Gold Surface Improve DNA Hybridization in Complex Media

International Nuclear Information System (INIS)

Lee, C.; Gamble, L.; Grainger, D.; Castner, D.

2006-01-01

Reliable, direct 'sample-to-answer' capture of nucleic acid targets from complex media would greatly improve existing capabilities of DNA microarrays and biosensors. This goal has proven elusive for many current nucleic acid detection technologies attempting to produce assay results directly from complex real-world samples, including food, tissue, and environmental materials. In this study, we have investigated mixed self-assembled thiolated single-strand DNA (ssDNA) monolayers containing a short thiolated oligo(ethylene glycol) (OEG) surface diluent on gold surfaces to improve the specific capture of DNA targets from complex media. Both surface composition and orientation of these mixed DNA monolayers were characterized with x-ray photoelectron spectroscopy (XPS) and near-edge x-ray absorption fine structure (NEXAFS). XPS results from sequentially adsorbed ssDNA/OEG monolayers on gold indicate that thiolated OEG diluent molecules first incorporate into the thiolated ssDNA monolayer and, upon longer OEG exposures, competitively displace adsorbed ssDNA molecules from the gold surface. NEXAFS polarization dependence results (followed by monitoring the N 1s→π* transition) indicate that adsorbed thiolated ssDNA nucleotide base-ring structures in the mixed ssDNA monolayers are oriented more parallel to the gold surface compared to DNA bases in pure ssDNA monolayers. This supports ssDNA oligomer reorientation towards a more upright position upon OEG mixed adlayer incorporation. DNA target hybridization on mixed ssDNA probe/OEG monolayers was monitored by surface plasmon resonance (SPR). Improvements in specific target capture for these ssDNA probe surfaces due to incorporation of the OEG diluent were demonstrated using two model biosensing assays, DNA target capture from complete bovine serum and from salmon genomic DNA mixtures. SPR results demonstrate that OEG incorporation into the ssDNA adlayer improves surface resistance to both nonspecific DNA and protein

Tailoring the vortex pinning strength of YBCO thin films by systematic incorporation of hybrid artificial pinning centers

International Nuclear Information System (INIS)

Jha, Alok K; Matsumoto, Kaname; Horide, Tomoya; Saini, Shrikant; Mele, Paolo; Ichinose, Ataru; Yoshida, Yutaka; Awaji, Satoshi

2015-01-01

The effect of hybrid (columnar and spherical together) artificial pinning centers (APCs) on the vortex pinning properties of YBa 2 Cu 3 O 7−δ (YBCO) thin films is investigated in detail on the basis of variation of critical current density (J C ) with applied magnetic field and also with the orientation of the applied magnetic field at 65 K and 77 K. Premixed YBCO + BaSnO 3 composite targets are used for the deposition of the YBCO films which consist of self-assembled BaSnO 3 nanocolumns (1D APCs); on the other hand, for the deposition of the YBCO films with hybrid APCs (BaSnO 3 nanocolumns together with Y 2 O 3 nanoparticles), the surface of the premixed YBCO + BaSnO 3 composite targets are modified by putting a thin Y 2 O 3 sectored piece on the premixed YBCO + BaSnO 3 composite targets by means of silver paste. F pmax value increases systematically with incorporation of 1D and 1D and 3D APCs and it also shifts towards higher applied magnetic fields. Films with 1D APCs exhibit a strong J C peak at Θ = 0° (H//c-axis) whereas films consisting of hybrid APCs exhibit enhanced J C at all the investigated angular regimes. A possible mechanism of vortex pinning in samples with hybrid APCs is also discussed suggesting the role of 1D and 3D APCs. (paper)

Deep-subwavelength light routing in nanowire-loaded surface plasmon polariton waveguides: an alternative to the hybrid guiding scheme

International Nuclear Information System (INIS)

Bian, Yusheng; Gong, Qihuang

2013-01-01

Nanowire-loaded surface plasmon polariton waveguide is an extremely simple structure that can be naturally formed by directly dropping a dielectric cylinder onto a metallic substrate. However, despite the substantial emphasis devoted to its hybrid plasmonic counterparts, this waveguiding structure has been paid little attention to so far. Here in this paper, through comprehensive numerical analysis, we reveal that such a configuration can be leveraged to achieve deep-subwavelength field confinement with mode area more than one order of magnitude smaller than that of the conventional hybrid waveguide, while maintaining a moderate attenuation with propagation distance over tens of microns. Two-dimensional parameter mapping concerning physical dimension, shape and material of the nanowire as well as the refractive index of the cladding has disclosed the wide-range existence nature of this plasmonic mode and the feasibility to further balance its confinement and loss. (paper)

System for cooling hybrid vehicle electronics, method for cooling hybrid vehicle electronics

Science.gov (United States)

France, David M.; Yu, Wenhua; Singh, Dileep; Zhao, Weihuan

2017-11-21

The invention provides a single radiator cooling system for use in hybrid electric vehicles, the system comprising a surface in thermal communication with electronics, and subcooled boiling fluid contacting the surface. The invention also provides a single radiator method for simultaneously cooling electronics and an internal combustion engine in a hybrid electric vehicle, the method comprising separating a coolant fluid into a first portion and a second portion; directing the first portion to the electronics and the second portion to the internal combustion engine for a time sufficient to maintain the temperature of the electronics at or below 175.degree. C.; combining the first and second portion to reestablish the coolant fluid; and treating the reestablished coolant fluid to the single radiator for a time sufficient to decrease the temperature of the reestablished coolant fluid to the temperature it had before separation.

Non-Gaussianities and curvature perturbations from hybrid inflation

Science.gov (United States)

Clesse, Sébastien; Garbrecht, Björn; Zhu, Yi

2014-03-01

For the original hybrid inflation as well as the supersymmetric F-term and D-term hybrid models, we calculate the level of non-Gaussianities and the power spectrum of curvature perturbations generated during the waterfall, taking into account the contribution of entropic modes. We focus on the regime of mild waterfall, in which inflation continues for more than about 60 e-folds N during the waterfall. We find that the associated fNL parameter goes typically from fNL≃-1/Nexit in the regime with N ≫60, where Nexit is the number of e-folds between the time of Hubble exit of a pivot scale and the end of inflation, down to fNL˜-0.3 when N ≳60, i.e., much smaller in magnitude than the current bound from Planck. Considering only the adiabatic perturbations, the power spectrum is red, with a spectral index ns=1-4/Nexit in the case N ≫60, whereas in the case N≳60, it increases up to unity. Including the contribution of entropic modes does not change observable predictions in the first case, and the spectral index is too low for this regime to be viable. In the second case, entropic modes are a relevant source for the power spectrum of curvature perturbations, of which the amplitude increases by several orders of magnitude. When spectral index values are consistent with observational constraints, the primordial spectrum amplitude is much larger than the observed value and can even lead to black hole formation. We conclude that, due to the important contribution of entropic modes, the parameter space leading to a mild waterfall phase is excluded by cosmic microwave background observations for all the considered models.

Regime change?

International Nuclear Information System (INIS)

Pilat, Joseph F.; Budlong-Sylvester, K.W.

2004-01-01

Following the 1998 nuclear tests in South Asia and later reinforced by revelations about North Korean and Iraqi nuclear activities, there has been growing concern about increasing proliferation dangers. At the same time, the prospects of radiological/nuclear terrorism are seen to be rising - since 9/11, concern over a proliferation/terrorism nexus has never been higher. In the face of this growing danger, there are urgent calls for stronger measures to strengthen the current international nuclear nonproliferation regime, including recommendations to place civilian processing of weapon-useable material under multinational control. As well, there are calls for entirely new tools, including military options. As proliferation and terrorism concerns grow, the regime is under pressure and there is a temptation to consider fundamental changes to the regime. In this context, this paper will address the following: Do we need to change the regime centered on the Treaty on the Nonproliferation of Nuclear Weapons (NPT) and the International Atomic Energy Agency (IAEA)? What improvements could ensure it will be the foundation for the proliferation resistance and physical protection needed if nuclear power grows? What will make it a viable centerpiece of future nonproliferation and counterterrorism approaches?

Calculation of the thermal regime of a stepped combustion chamber

Energy Technology Data Exchange (ETDEWEB)

Baskarev, B.N.; Gilevich, D.D.; Ostras, V.N.; Shvarts, IU.G.

1985-01-01

The effective-length method is used to calculate the heat-transfer characteristics and thermal regime of the walls of a stepped scramjet combustor. Based on this method, a formula is proposed for calculating heat transfer between the transition boundary layer and a nonporous surface. 13 references.

Chemical/Light-Powered Hybrid Micromotors with "On-the-Fly" Optical Brakes.

Science.gov (United States)

Chen, Chuanrui; Tang, Songsong; Teymourian, Hazhir; Karshalev, Emil; Zhang, Fangyu; Li, Jinxing; Mou, Fangzhi; Liang, Yuyan; Guan, Jianguo; Wang, Joseph

2018-07-02

Hybrid micromotors capable of both chemically powered propulsion and fuel-free light-driven actuation and offering built-in optical brakes for chemical propulsion are described. The new hybrid micromotors are designed by combining photocatalytic TiO 2 and catalytic Pt surfaces into a Janus microparticle. The chemical reactions on the different surfaces of the Janus particle hybrid micromotor can be tailored by using chemical or light stimuli that generate counteracting propulsion forces on the catalytic Pt and photocatalytic TiO 2 sides. Such modulation of the surface chemistry on a single micromotor leads to switchable propulsion modes and reversal of the direction of motion that reflect the tuning of the local ion concentration and hence the dominant propulsion force. An intermediate Au layer (under the Pt surface) plays an important role in determining the propulsion mechanism and operation of the hybrid motor. The built-in optical braking system allows "on-the-fly" control of the chemical propulsion through a photocatalytic reaction on the TiO 2 side to counterbalance the chemical propulsion force generated on the Pt side. The adaptive dual operation of these chemical/light hybrid micromotors, associated with such control of the surface chemistry, holds considerable promise for designing smart nanomachines that autonomously reconfigure their propulsion mode for various on-demand operations. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Comparison of H-mode pedestals in different confinement regimes in DIII-D

Energy Technology Data Exchange (ETDEWEB)

Groebner, R J [General Atomics, PO Box 85608, San Diego, California, 92186-5608 (United States); Leonard, A W [General Atomics, PO Box 85608, San Diego, California, 92186-5608 (United States); Luce, T C [General Atomics, PO Box 85608, San Diego, California, 92186-5608 (United States); Fenstermacher, M E [Lawrence Livermore National Laboratory, Livermore, California (United States); Jackson, G L [General Atomics, PO Box 85608, San Diego, California, 92186-5608 (United States); Osborne, T H [General Atomics, PO Box 85608, San Diego, California, 92186-5608 (United States); Thomas, D M [General Atomics, PO Box 85608, San Diego, California, 92186-5608 (United States); Wade, M R [General Atomics, PO Box 85608, San Diego, California, 92186-5608 (United States)

2006-05-15

A survey of global performance parameters and their correlation with pedestal parameters is performed for standard H-mode, QH-mode and the enhanced confinement regimes of VH-mode, hybrid and advanced tokamak in the DIII-D tokamak. This study shows that there is a trend for global confinement quality or global beta to increase as the pedestal electron pressure or beta increases. However, there are also improvements in core confinement and beta, observed at fixed pedestal pressure or beta, which indicate that factors other than pedestal parameters also contribute to the best core performance. Several other pedestal structure parameters are found to be similar among these regimes. The scale lengths for electron pressure in the pedestal are in the range 0.8-1.6 cm at the outer midplane, most {eta}{sub e} values are in the range 1-3 in the middle of the T{sub e} pedestal and the T{sub e} and n{sub e} pedestals tend to penetrate the same distance into the plasma.

A hybrid scanning force and light microscope for surface imaging and three-dimensional optical sectioning in differential interference contrast.

Science.gov (United States)

Stemmer, A

1995-04-01

The design of a scanned-cantilever-type force microscope is presented which is fully integrated into an inverted high-resolution video-enhanced light microscope. This set-up allows us to acquire thin optical sections in differential interference contrast (DIC) or polarization while the force microscope is in place. Such a hybrid microscope provides a unique platform to study how cell surface properties determine, or are affected by, the three-dimensional dynamic organization inside the living cell. The hybrid microscope presented in this paper has proven reliable and versatile for biological applications. It is the only instrument that can image a specimen by force microscopy and high-power DIC without having either to translate the specimen or to remove the force microscope. Adaptation of the design features could greatly enhance the suitability of other force microscopes for biological work.

Arctic circulation regimes.

Science.gov (United States)

Proshutinsky, Andrey; Dukhovskoy, Dmitry; Timmermans, Mary-Louise; Krishfield, Richard; Bamber, Jonathan L

2015-10-13

Between 1948 and 1996, mean annual environmental parameters in the Arctic experienced a well-pronounced decadal variability with two basic circulation patterns: cyclonic and anticyclonic alternating at 5 to 7 year intervals. During cyclonic regimes, low sea-level atmospheric pressure (SLP) dominated over the Arctic Ocean driving sea ice and the upper ocean counterclockwise; the Arctic atmosphere was relatively warm and humid, and freshwater flux from the Arctic Ocean towards the subarctic seas was intensified. By contrast, during anticylonic circulation regimes, high SLP dominated driving sea ice and the upper ocean clockwise. Meanwhile, the atmosphere was cold and dry and the freshwater flux from the Arctic to the subarctic seas was reduced. Since 1997, however, the Arctic system has been under the influence of an anticyclonic circulation regime (17 years) with a set of environmental parameters that are atypical for this regime. We discuss a hypothesis explaining the causes and mechanisms regulating the intensity and duration of Arctic circulation regimes, and speculate how changes in freshwater fluxes from the Arctic Ocean and Greenland impact environmental conditions and interrupt their decadal variability. © 2015 The Authors.

Causas estruturais e consequências dos regimes internacionais: regimes como variáveis intervenientes

Directory of Open Access Journals (Sweden)

Stephen D. Krasner

2012-06-01

Full Text Available Os regimes internacionais são definidos como princípios, normas, regras e procedimentos de tomada de decisões ao redor dos quais as expectativas dos atores convergem em uma dada área-tema. Como ponto de partida, os regimes são conceituados como variáveis intervenientes, estando entre fatores causais básicos e os resultados e comportamentos relacionados. Há três visões a respeito da importância dos regimes: as orientações estruturais convencionais desvalorizam os regimes como sendo, na melhor das hipóteses, ineficazes; as orientações grocianas vêem os regimes como componentes íntimos do sistema internacional; as perspectivas estruturalistas modificadas vêem os regimes como significativos somente em certas condições restritas. Para os argumentos grociano e estruturalista modificado - que concordam com a visão de que os regimes podem influenciar resultados e comportamentos - , o desenvolvimento de regimes é visto como uma função de cinco variáveis causais básicas: auto-interesse egoísta; poder político; normas e princípios difusos; usos e costumes; conhecimento.

Non-covalently functionalized carbon nanostructures for synthesizing carbon-based hybrid nanomaterials.

Science.gov (United States)

Li, Haiqing; Song, Sing I; Song, Ga Young; Kim, Il

2014-02-01

Carbon nanostructures (CNSs) such as carbon nanotubes, graphene sheets, and nanodiamonds provide an important type of substrate for constructing a variety of hybrid nanomaterials. However, their intrinsic chemistry-inert surfaces make it indispensable to pre-functionalize them prior to immobilizing additional components onto their surfaces. Currently developed strategies for functionalizing CNSs include covalent and non-covalent approaches. Conventional covalent treatments often damage the structure integrity of carbon surfaces and adversely affect their physical properties. In contrast, the non-covalent approach offers a non-destructive way to modify CNSs with desired functional surfaces, while reserving their intrinsic properties. Thus far, a number of surface modifiers including aromatic compounds, small-molecular surfactants, amphiphilic polymers, and biomacromolecules have been developed to non-covalently functionalize CNS surfaces. Mediated by these surface modifiers, various functional components such as organic species and inorganic nanoparticles were further decorated onto their surfaces, resulting in versatile carbon-based hybrid nanomaterials with broad applications in chemical engineering and biomedical areas. In this review, the recent advances in the generation of such hybrid nanostructures based on non-covalently functionalized CNSs will be reviewed.

Hybrid Surface Plasmon Polariton Modes of Subwavelength Nanowire Resonators

DEFF Research Database (Denmark)

Filonenko, Konstantin; Duggen, Lars; Willatzen, Morten

2015-01-01

-localized gap plasmon mode are studied depending on the vacuum wavelength. In order to directly compare resonators, where metal and semiconductor nanowires are employed, we consider the two resonators, both including silver slab and magnesium fluoride gap region, as is shown in figure. The two compared......We perform Comsol simulations of two types of hybrid plasmonic resonator configurations, similar to those proposed for nanowire plasmonic laser in [1] and [2]. In both references the nanowire - based plasmonic resonators are studied, which overall sizes are larger than the wavelength in vacuum....... However, it is advantageous for the nanolaser to have subwavelength sizes at least in two dimensions. Therefore, we study the two configurations and the hybrid mode behavior in the case, where resonator sizes are smaller than the half of the wavelength in vacuum. First, we assume finite dimensions...

Winter-regime surface heat loss from heated streams

International Nuclear Information System (INIS)

Paily, P.P.; Macagno, E.O.; Kennedy, J.F.

1974-01-01

Evaluation of the rate of surface heat exchange between the water and air is a significant factor in any study of the thermal response of heated streams to heat inputs. Existing methods to determine the amount of heat transfer across the water surface are surveyed, and the different formulas developed for determining the heat exchange components are compiled. Heat-transfer models that have been proposed in the literature are reviewed, and a new linearized model for determining the rate of surface heat exchange is proposed. Generalized relations between the major climatological factors and the coefficients of the linearized heat-loss rate are established by multiple-regression analysis. The analysis is limited to cold-period conditions, in the sense that air temperatures below the freezing point of water only are considered in developing the regression equations. A computer program, using FORTRAN, is presented which enables the computation of the coefficients appearing in the linearized heat-loss rate for all combinations of the various climatological factors

A polyvalent hybrid protein elicits antibodies against the diverse allelic types of block 2 in Plasmodium falciparum merozoite surface protein 1.

Science.gov (United States)

Tetteh, Kevin K A; Conway, David J

2011-10-13

Merozoite surface protein 1 (MSP1) of Plasmodium falciparum has been implicated as an important target of acquired immunity, and candidate components for a vaccine include polymorphic epitopes in the N-terminal polymorphic block 2 region. We designed a polyvalent hybrid recombinant protein incorporating sequences of the three major allelic types of block 2 together with a composite repeat sequence of one of the types and N-terminal flanking T cell epitopes, and compared this with a series of recombinant proteins containing modular sub-components and similarly expressed in Escherichia coli. Immunogenicity of the full polyvalent hybrid protein was tested in both mice and rabbits, and comparative immunogenicity studies of the sub-component modules were performed in mice. The full hybrid protein induced high titre antibodies against each of the major block 2 allelic types expressed as separate recombinant proteins and against a wide range of allelic types naturally expressed by a panel of diverse P. falciparum isolates, while the sub-component modules had partial antigenic coverage as expected. This encourages further development and evaluation of the full MSP1 block 2 polyvalent hybrid protein as a candidate blood-stage component of a malaria vaccine. Copyright © 2011 Elsevier Ltd. All rights reserved.

Hybrid nanostructures: synthesis, morphology and functional properties

International Nuclear Information System (INIS)

Povolotskaya, A V; Povolotskiy, A V; Manshina, A A

2015-01-01

Hybrid nanostructures representing combinations of different materials and possessing properties that are absent in separate components forming the hybrid are discussed. Particular attention is given to hybrid structures containing plasmonic and magnetic nanoparticles, methods of their synthesis and the relationship between the composition, structure and properties. The functional features of the hybrid nanomaterials of various morphology (with core–shell structures, with encapsulated metal nanoparticles and with metal nanoparticles on the surface) are considered. The unique properties of these hybrid materials are demonstrated, which are of interest for solving problems of catalysis and photocatalysis, detecting impurities in various media, in vivo visualization, bioanalysis, as well as for the design of optical labels and multifunctional diagnostic nanoplatforms. The bibliography includes 182 references

Thermal regime of an ice-wedge polygon landscape near Barrow, Alaska

Science.gov (United States)

Daanen, R. P.; Liljedahl, A. K.

2017-12-01

Tundra landscapes are changing all over the circumpolar Arctic due to permafrost degradation. Soil cracking and infilling of meltwater repeated over thousands of years form ice wedges, which produce the characteristic surface pattern of ice-wedge polygon tundra. Rapid top-down thawing of massive ice leads to differential ground subsidence and sets in motion a series of short- and long-term hydrological and ecological changes. Subsequent responses in the soil thermal regime drive further permafrost degradation and/or stabilization. Here we explore the soil thermal regime of an ice-wedge polygon terrain near Utqiagvik (formerly Barrow) with the Water balance Simulation Model (WaSiM). WaSiM is a hydro-thermal model developed to simulate the water balance at the watershed scale and was recently refined to represent the hydrological processes unique to cold climates. WaSiM includes modules that represent surface runoff, evapotranspiration, groundwater, and soil moisture, while active layer freezing and thawing is based on a direct coupling of hydrological and thermal processes. A new snow module expands the vadose zone calculations into the snow pack, allowing the model to simulate the snow as a porous medium similar to soil. Together with a snow redistribution algorithm based on local topography, this latest addition to WaSiM makes simulation of the ground thermal regime much more accurate during winter months. Effective representation of ground temperatures during winter is crucial in the simulation of the permafrost thermal regime and allows for refined predictions of future ice-wedge degradation or stabilization.

Hybrid selective surface hydrophilization and froth flotation separation of hazardous chlorinated plastics from E-waste with novel nanoscale metallic calcium composite

Energy Technology Data Exchange (ETDEWEB)

Mallampati, Srinivasa Reddy, E-mail: srireddys@ulsan.ac.kr; Heo, Je Haeng; Park, Min Hee

2016-04-05

Highlights: • Nanometallic Ca/CaO treatment significantly enhanced PVC surface hydrophilicity. • The contact angle of PVC significantly decreased compared to other E-waste plastics. • 100% of PVC was selectively separated with 96.4% purity from E-waste plastics. • SEM/XPS results indicated an oxidative degradation of chlorides on the PVC surface. • Hybrid treatment with nanometallic Ca/CaO and froth flotation is effective. - Abstract: Treatment by a nanometallic Ca/CaO composite has been found to selectively hydrophilize the surface of polyvinyl chloride (PVC), enhancing its wettability and thereby promoting its separation from E-waste plastics by means of froth flotation. The treatment considerably decreased the water contact angle of PVC, by about 18°. The SEM images of the PVC plastic after treatment displayed significant changes in their surface morphology compared to other plastics. The SEM-EDS results reveal that a markedly decrease of [Cl] concentration simultaneously with dramatic increase of [O] on the surface of the PCV samples. XPS results further confirmed an increase of hydrophilic functional groups on the PVC surface. Froth flotation at 100 rpm mixing speed was found to be optimal, separating 100% of the PVC into a settled fraction of 96.4% purity even when the plastics fed into the reactor were of nonuniform size and shape. The total recovery of PVC-free plastics in E-waste reached nearly 100% in the floated fraction, significantly improved from the 20.5 wt% of light plastics that can be recovered by means of conventional wet gravity separation. The hybrid method of nanometallic Ca/CaO treatment and froth flotation is effective in the separation of hazardous chlorinated plastics from E-waste plastics.

Hybrid selective surface hydrophilization and froth flotation separation of hazardous chlorinated plastics from E-waste with novel nanoscale metallic calcium composite

International Nuclear Information System (INIS)

Mallampati, Srinivasa Reddy; Heo, Je Haeng; Park, Min Hee

2016-01-01

Highlights: • Nanometallic Ca/CaO treatment significantly enhanced PVC surface hydrophilicity. • The contact angle of PVC significantly decreased compared to other E-waste plastics. • 100% of PVC was selectively separated with 96.4% purity from E-waste plastics. • SEM/XPS results indicated an oxidative degradation of chlorides on the PVC surface. • Hybrid treatment with nanometallic Ca/CaO and froth flotation is effective. - Abstract: Treatment by a nanometallic Ca/CaO composite has been found to selectively hydrophilize the surface of polyvinyl chloride (PVC), enhancing its wettability and thereby promoting its separation from E-waste plastics by means of froth flotation. The treatment considerably decreased the water contact angle of PVC, by about 18°. The SEM images of the PVC plastic after treatment displayed significant changes in their surface morphology compared to other plastics. The SEM-EDS results reveal that a markedly decrease of [Cl] concentration simultaneously with dramatic increase of [O] on the surface of the PCV samples. XPS results further confirmed an increase of hydrophilic functional groups on the PVC surface. Froth flotation at 100 rpm mixing speed was found to be optimal, separating 100% of the PVC into a settled fraction of 96.4% purity even when the plastics fed into the reactor were of nonuniform size and shape. The total recovery of PVC-free plastics in E-waste reached nearly 100% in the floated fraction, significantly improved from the 20.5 wt% of light plastics that can be recovered by means of conventional wet gravity separation. The hybrid method of nanometallic Ca/CaO treatment and froth flotation is effective in the separation of hazardous chlorinated plastics from E-waste plastics.

Characterization of potential fire regimes: applying landscape ecology to fire management in Mexico

Science.gov (United States)

Jardel, E.; Alvarado, E.; Perez-Salicrup, D.; Morfín-Rios, J.

2013-05-01

Knowledge and understanding of fire regimes is fundamental to design sound fire management practices. The high ecosystem diversity of Mexico offers a great challenge to characterize the fire regime variation at the landscape level. A conceptual model was developed considering the main factors controlling fire regimes: climate and vegetation cover. We classified landscape units combining bioclimatic zones from the Holdridge life-zone system and actual vegetation cover. Since bioclimatic conditions control primary productivity and biomass accumulation (potential fuel), each landscape unit was considered as a fuel bed with a particular fire intensity and behavior potential. Climate is also a determinant factor of post-fire recovery rates of fuel beds, and climate seasonality (length of the dry and wet seasons) influences fire probability (available fuel and ignition efficiency). These two factors influence potential fire frequency. Potential fire severity can be inferred from fire frequency, fire intensity and behavior, and vegetation composition and structure. Based in the conceptual model, an exhaustive literature review and expert opinion, we developed rules to assign a potential fire regime (PFR) defined by frequency, intensity and severity (i.e. fire regime) to each bioclimatic-vegetation landscape unit. Three groups and eight types of potential fire regimes were identified. In Group A are fire-prone ecosystems with frequent low severity surface fires in grasslands (PFR type I) or forests with long dry season (II) and infrequent high-severity fires in chaparral (III), wet temperate forests (IV, fire restricted by humidity), and dry temperate forests (V, fire restricted by fuel recovery rate). Group B includes fire-reluctant ecosystems with very infrequent or occasional mixed severity surface fires limited by moisture in tropical rain forests (VI) or fuel availability in seasonally dry tropical forests (VII). Group C and PFR VIII include fire-free environments

Gravity waves from tachyonic preheating after hybrid inflation

Energy Technology Data Exchange (ETDEWEB)

Dufaux, Jean-Francois [Instituto de Fisica Teorica UAM/CSIC, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain); Felder, Gary [Department of Physics, Clark Science Center, Smith College, Northampton, MA 01063 (United States); Kofman, Lev [CITA, University of Toronto, 60 St. George Street, Toronto, ON M5S 3H8 (Canada); Navros, Olga, E-mail: jeff.dufaux@uam.es, E-mail: gfelder@email.smith.edu, E-mail: kofman@cita.utoronto.ca, E-mail: navros@email.unc.edu [Department of Mathematics, University of North Carolina Chapel Hill, CB3250 Philips Hall, Chapel Hill, NC 27599 (United States)

2009-03-15

We study the stochastic background of gravitational waves produced from preheating in hybrid inflation models. We investigate different dynamical regimes of preheating in these models and we compute the resulting gravity wave spectra using analytical estimates and numerical simulations. We discuss the dependence of the gravity wave frequencies and amplitudes on the various potential parameters. We find that large regions of the parameter space leads to gravity waves that may be observable in upcoming interferometric experiments, including Advanced LIGO, but this generally requires very small coupling constants.

Graphene-based hybrid plasmonic modulator

International Nuclear Information System (INIS)

Shin, Jin-Soo; Kim, Jin-Soo; Tae Kim, Jin

2015-01-01

A graphene-based hybrid plasmonic modulator is designed based on an asymmetric double-electrode plasmonic waveguide structure. The photonic device consists of a monolayer graphene, a thin metal strip, and a thin dielectric layer that is inserted between the grapheme and the metal strip. By electrically tuning the graphene’s refractive index, the propagation loss of the hybrid long-range surface plasmon polariton strip mode in the proposed graphene-based hybrid plasmonic waveguide is switchable, and hence the intensity of the guided modes is modulated. The highest modulation depth is observed at the graphene’s epsilon-near-zero region. The device characteristics are characterized over the entire C-band (1.530–1.565 μm). (paper)

Hybrid HF-DFT comparative study of SrZrO{sub 3} and SrTiO{sub 3}(001) surface properties

Energy Technology Data Exchange (ETDEWEB)

Evarestov, R.A.; Bandura, A.V.; Alexandrov, V.E. [Department of Quantum Chemistry, St. Petersburg State University, 26 Universitetskii Prospekt, Stary Petergof, 198504 St. Petersburg (Russian Federation)

2006-10-15

Hybrid HF-DFT LCAO simulations of SrZrO{sub 3} and SrTiO{sub 3}(001) surface properties are performed in a single-slab model framework. The SrZrO{sub 3}(001) surface was studied by an ab initio method for the first time. Three slab models with different surface terminations including up to 8 atomic planes were used for calculation of the various surface characteristics (surface energies, atomic charges, density of electronic states). The dependence of the results on the chosen model and on the kind of d-element is analyzed. The dissimilarity in the surface oxygen atom contributions to the total density of states of two crystals is attributed to the more ionic nature of Zr-O bonds compared to Ti-O bonds. It is found that in the case of SrZrO{sub 3} the electronic density is biased towards the SrO-terminated surface and this surface should be more basic in nature than the SrO surface of SrTiO{sub 3} crystal. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Effect of toroidicity during lower hybrid mode conversion

International Nuclear Information System (INIS)

Riyopoulos, S.; Mahajan, S.

1985-11-01

The effect of toroidicity during lower hybrid mode conversion is examined by treating the wave propagation in an inhomogeneous medium as an eigenvalue problem for ω 2 (m,n),m,n poloidal and toroidal wave numbers. Since the frequency regime near ω 2 = ω/sub LH/ 2 is an accumulation point for the eigenvalue spectrum, the degenerate perturbation technique must be applied. The toroidal eigenmodes are constructed by a zeroth order superposition of monochromatic solutions with different poloidal dependence m, thus they generically exhibit a wide spectrum in k/sub parallel/ for given fixed ω 2 even for small inverse aspect ratio epsilon. In case that the average is in the neighborhood of k/sub min/, the minimum wave number for accessibility of the mode conversion regime, it is expected that excitation of toroidal modes rather than geometric optics will determine the wave coupling to the plasma

Fabrication and characterization of stable superhydrophobic fluorinated-polyacrylate/silica hybrid coating

Science.gov (United States)

Li, Kunquan; Zeng, Xingrong; Li, Hongqiang; Lai, Xuejun

2014-04-01

The core-shell fluorinated-polyacrylate (PFA) emulsion was synthesized through emulsion polymerization method and the superhydrophobic PFA/SiO2 hybrid coating was successfully fabricated on the slide glass by spraying the mixture of PFA emulsion and hydrophobic SiO2 particles using ethanol as cosolvent. The PFA emulsion was characterized by Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), water contact angle (WCA), transmission electron microscopy (TEM), and the effects of SiO2 content on the wetting behavior and surface morphology of PFA/SiO2 hybrid coating were investigated. To evaluate the stability of the hybrid coating, the acid and base resistance, weatherability and thermal stability were also studied. Results showed that the obtained PFA latex exhibited a core-shell structure with a particle size of 134.1 nm and a narrow polydispersity of 0.03. With the increase of dodecafluoroheptyl methacrylate (DFMA) content in the latex shell from 0 wt% to 31.8 wt%, the WCA of the PFA film enlarged from 85° to 104°, indicating that the introduction of fluorinated monomer was effective in reducing the surface energy. By adding different amount of SiO2 particles, the surface morphology and wetting behavior of the PFA/SiO2 hybrid coatings could be controlled. When the mass ratio of SiO2 to PFA emulsion was 0.2, the surface roughness (Rq) increased to 173.6 nm and the wetting behavior of the surface became superhydrophobic with a WCA of 153°, resulted from the corporation of low surface energy and the binary nano/microstructure on the surface. The as-prepared PFA/SiO2 hybrid coating showed good acid and base corrosion resistance, and it could keep superhydrophobicity after being heated at 250 °C for 2 h or exposed to ambient atmosphere for more than 3 months. Additionally, the superhydrophobic PFA/SiO2 hybrid coating could be applied to various substrates through spraying. This was a green and eco-friendly method in fabricating stable

Plasma-surface interactions with ICRF antennas and lower hybrid grills in Tore Supra

Energy Technology Data Exchange (ETDEWEB)

Harris, J.H. [Oak Ridge National Lab., TN (United States); Hutter, T. [Association Euratom-CEA, Centre d`Etudes de Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee; Hogan, J.T. [Oak Ridge National Lab., TN (United States)] [and others

1996-10-01

The edge plasma interactions of the actively cooled radio-frequency heating launchers in Tore Supra- ion-cyclotron range-of-frequencies (ICRF) antennas and lower-hybrid (LH) grills-are studied using infrared video imaging. On the two-strap ICRF antennas, operated in fast-wave electron heating or current drive mode, hot spots with temperatures of 500-900{degrees} C are observed by the end of 2-s power pulses of 2 MW per antenna. The distribution and maximum values of temperature are determined principally by the relative phase of the two antenna straps: dipole (heating) phasing results in significantly less antenna heating than does 90` (current drive) phasing. Transient heat fluxes of 1-20 MW/m{sup 2} are measured on the lateral protection bumpers at ICRF turn-on; these fluxes are primarily a function of plasma and radio frequency (rf) control, and are not simply correlated with the strap phasing or the final surface temperature distributions. The remarkable feature of the lower hybrid edge interaction is the production of beams of heat flux in front of the grills; these beams propagate along the helical magnetic field lines and can deliver fluxes of 5-10 MW/m{sup 2} over areas of several cm{sup 2} to plasma-facing components such as the grill or antenna lateral bumpers. Both the ICRF and LH phenomena appear to result from the acceleration of particles by the near fields of the launchers. Modeling of the heat flux deposition on components and its relation to sputtering processes is presented, and possibilities for controlling these interactions are discussed.

Study of the mobility, surface area, and sintering behavior of agglomerates in the transition regime by tandem differential mobility analysis

International Nuclear Information System (INIS)

Cho, Kuk; Hogan, Christopher J.; Biswas, Pratim

2007-01-01

The surface area of nanosized agglomerates is of great importance as the reactivity and health effects of such particles are highly dependent on surface area. Changes in surface area through sintering during nanoparticle synthesis processes are also of interest for precision control of synthesised particles. Unfortunately, information on particle surface area and surface area dynamics is not readily obtainable through traditional particle mobility sizing techniques. In this study, we have experimentally determined the mobility diameter of transition regime agglomerates with 3, 4, and 5 primary particles. Agglomerates were produced by spray drying well-characterised polystyrene latex particles with diameters of 55, 67, 76, and 99 nm. Tandem differential mobility analysis was used to determine agglomerate mobility diameter by selecting monodisperse agglomerates with the same number of primary particles in the first DMA, and subsequently completely sintering the agglomerates in a furnace aerosol reactor. The size distribution of the completely sintered particles was measured by an SMPS system, which allowed for the determination of the number of primary particles in the agglomerates. A simple power law regression was used to express mobility diameter as a function of primary particle size and the number of primary particles, and had an excellent correlation (R 2 = 0.9971) with the experimental data. A scaling exponent was determined from the experimental data to relate measured mobility diameter to surface area for agglomerates. Using this relationship, the sintering characteristics of agglomerates were also examined for varying furnace temperatures and residence times. The sintering data agreed well with the geometric sintering model (GSM) model proposed by Cho and Biswas (2006a) as well as with the model proposed Koch and Friedlander (1990) for sintering by viscous flow

Wetting properties of hybrid structure with hydrophilic ridges and hydrophobic channels

Science.gov (United States)

Lee, Dong-Ki; Choi, Su Young; Park, Min Soo; Cho, Young Hak

2018-02-01

In the present study, we fabricated a hybrid structure where the upper surface of the ridge is hydrophilic and the inner surface of the channel is hydrophobic. Laser-induced backside wet etching (LIBWE) process was performed to machine the hybrid structure on a Pyrex glass substrate. Wetting properties were evaluated from static contact angles (CAs) measurement in parallel and orthogonal directions. The water droplet on the hybrid structure was in the Cassie-Baxter state and showed anisotropic wetting property along groove lines. Moisture condensation studies under humid condition indicated that water droplets grew and coalesced on the ridge with hydrophilicity. Furthermore, water-oil separation was tested using a microfluidic chip with the developed hybrid structure. In case of hybrid microfluidic chip, the water could not flow into channel but the hexadecane could flow due to the capillary pressure difference.

Harmonics radiation of graphene surface plasmon polaritons in terahertz regime

Energy Technology Data Exchange (ETDEWEB)

Li, D., E-mail: dazhi_li@hotmail.com [Institute for Laser Technology, Suita, Osaka 565-0871 (Japan); Wang, Y. [School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054 (China); Nakajima, M. [Institute of Laser Engineering, Osaka University, Suita, Osaka 565-0871 (Japan); Hashida, M. [Advanced Research Center for Beam Science, ICR, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); Wei, Y. [School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054 (China); Miyamoto, S. [Laboratory of Advanced Science and Technology for Industry, University of Hyogo, Ako, Hyogo 678-1205 (Japan)

2016-06-03

This letter presents an approach to extract terahertz radiation from surface plasmon polaritons excited in the surface of a uniform graphene structure by an electron beam. A sidewall configuration is proposed to lift the surface plasmon mode to be close to the light line, so that some of its harmonics have chances to go above the light line and become radiative. The harmonics are considered to be excited by a train of periodic electron bunches. The physical mechanism in this scheme is analyzed with three-dimensional theory, and the harmonics excitation and radiation are demonstrated through numerical calculations. The results show that this technique could be an alternative to transform the surface plasmon polaritons into radiation. - Highlights: • An approach to extract terahertz radiation from graphene surface plasmon polaritons is presented. • A sidewall configuration is proposed to lift the surface plasmon mode. • Harmonics of surface plasmon polaritons are possible to radiate.

Asymmetric Hybrid Nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Chumanov, George [Clemson Univ., SC (United States)

2015-11-05

Hybrid Nanoparticles (AHNs) are rationally-designed multifunctional nanostructures and novel building blocks for the next generation of advanced materials and devices. Nanoscale materials attract considerable interest because of their unusual properties and potential for practical applications. Most of the activity in this field is focused on the synthesis of homogeneous nanoparticles from metals, metal oxides, semiconductors, and polymers. It is well recognized that properties of nanoparticles can be further enhanced if they are made as hybrid structures. This program is concerned with the synthesis, characterization, and application of such hybrid structures termed AHNs. AHNs are composed of a homogeneous core and several caps of different materials deposited on its surface (Fig. 1). Combined properties of the core and the caps as well as new properties that arise from core-cap and cap-cap interactions render AHNs multifunctional. In addition, specific chemical reactivity of the caps enables directional self-assembly of AHNs into complex architectures that are not possible with only spherical nanoparticles.

Adaptive two-regime method: Application to front propagation

Energy Technology Data Exchange (ETDEWEB)

Robinson, Martin, E-mail: martin.robinson@maths.ox.ac.uk; Erban, Radek, E-mail: erban@maths.ox.ac.uk [Mathematical Institute, University of Oxford, Andrew Wiles Building, Radcliffe Observatory Quarter, Woodstock Road, Oxford OX2 6GG (United Kingdom); Flegg, Mark, E-mail: mark.flegg@monash.edu [School of Mathematical Sciences, Faculty of Science, Monash University Wellington Road, Clayton, Victoria 3800 (Australia)

2014-03-28

The Adaptive Two-Regime Method (ATRM) is developed for hybrid (multiscale) stochastic simulation of reaction-diffusion problems. It efficiently couples detailed Brownian dynamics simulations with coarser lattice-based models. The ATRM is a generalization of the previously developed Two-Regime Method [Flegg et al., J. R. Soc., Interface 9, 859 (2012)] to multiscale problems which require a dynamic selection of regions where detailed Brownian dynamics simulation is used. Typical applications include a front propagation or spatio-temporal oscillations. In this paper, the ATRM is used for an in-depth study of front propagation in a stochastic reaction-diffusion system which has its mean-field model given in terms of the Fisher equation [R. Fisher, Ann. Eugen. 7, 355 (1937)]. It exhibits a travelling reaction front which is sensitive to stochastic fluctuations at the leading edge of the wavefront. Previous studies into stochastic effects on the Fisher wave propagation speed have focused on lattice-based models, but there has been limited progress using off-lattice (Brownian dynamics) models, which suffer due to their high computational cost, particularly at the high molecular numbers that are necessary to approach the Fisher mean-field model. By modelling only the wavefront itself with the off-lattice model, it is shown that the ATRM leads to the same Fisher wave results as purely off-lattice models, but at a fraction of the computational cost. The error analysis of the ATRM is also presented for a morphogen gradient model.

Organophosphonate functionalized silicon nanowires for DNA hybridization studies

Energy Technology Data Exchange (ETDEWEB)

Pedone, Daniel; Cattani Scholz, Anna; Birner, Stefan; Abstreiter, Gerhard [WSI, TU Muenchen (Germany); Dubey, Manish; Schwartz, Jeffrey [Princeton University, NJ (United States); Tornow, Marc [IHT, TU Braunschweig (Germany)

2007-07-01

Semiconductor nanowire field effect devices have great appeal for label-free sensing applications due to their sensitivity to surface potential changes that may originate from charged adsorbates. In addition to requiring high sensitivity, suitable passivation and functionalization of the semiconductor surface is obligatory. We have fabricated both freely suspended and oxide-supported silicon nanowires from Silicon-on-Insulator substrates using standard nanopatterning methods (EBL, RIE) and sacrificial oxide layer etching. Subsequent to nanofabrication, the devices were first coated with an hydroxyalkylphosphonate monolayer and then bound via bifunctional linker groups to single stranded DNA or PNA oligonucleotides, respectively. We investigated DNA hybridization on such functionalized nanowires using a difference resistance setup, where subtracting the reference signal from a second wire could be used to exclude most non-specific effects. A net change in surface potential on the order of a few mV could be detected upon addition of the complementary DNA strand. This surface potential change corresponds to the hybridization of about 10{sup 10}cm{sup -2} probe strands according to our model calculations that takes into account the entire hybrid system in electrolyte solution.

N-S/DSMC hybrid simulation of hypersonic flow over blunt body including wakes

Science.gov (United States)

Li, Zhonghua; Li, Zhihui; Li, Haiyan; Yang, Yanguang; Jiang, Xinyu

2014-12-01

A hybrid N-S/DSMC method is presented and applied to solve the three-dimensional hypersonic transitional flows by employing the MPC (modular Particle-Continuum) technique based on the N-S and the DSMC method. A sub-relax technique is adopted to deal with information transfer between the N-S and the DSMC. The hypersonic flows over a 70-deg spherically blunted cone under different Kn numbers are simulated using the CFD, DSMC and hybrid N-S/DSMC method. The present computations are found in good agreement with DSMC and experimental results. The present method provides an efficient way to predict the hypersonic aerodynamics in near-continuum transitional flow regime.

Generation of Localized Surface Plasmon Resonance Using Hybrid Au–Ag Nanoparticle Arrays as a Sensor of Polychlorinated Biphenyls Detection

Directory of Open Access Journals (Sweden)

Jing Liu

2016-08-01

Full Text Available In this study, the hybrid Au–Ag hexagonal lattice of triangular and square lattice of quadrate periodic nanoparticle arrays (PNAs were designed to investigate their extinction spectra of the localized surface plasmon resonances (LSPRs. First, their simulating extinction spectra were calculated by discrete dipole approximation (DDA numerical method by changing the media refractive index. Simulation results showed that as the media refractive index was changed from 1.0 to 1.2, the maximum peak intensity of LSPRs spectra had no apparent change and the wavelength to reveal the maximum peak intensity of LSPRs spectra was shifted lower value. Polystyrene (PS nanospheres with two differently arranged structures were used as the templates to deposit the hybrid Au–Ag hexagonal lattice of triangular and square lattice of quadrate periodic PNAs by evaporation method. The hybrid Au–Ag hexagonal lattice of triangular and square lattice of quadrate PNAs were grown on single crystal silicon (c-Si substrates, and their measured extinction spectra were compared with the calculated results. Finally, the fabricated hexagonal lattices of triangular PNAs were investigated as a sensor of polychlorinated biphenyl solution (PCB-77 by observing the wavelength to reveal the maximum extinction efficiency (λmax. We show that the adhesion of β-cyclodextrins (SH-β-CD on the hybrid Au–Ag hexagonal lattice of triangular PNAs could be used to increase the variation of λmax. We also demonstrate that the adhesion of SH-β-CD increases the sensitivity and detection effect of PCB-77 in hexagonal lattice of triangular PNAs.

Extreme Temperature Regimes during the Cool Season and their Associated Large-Scale Circulations

Science.gov (United States)

Xie, Z.

2015-12-01

In the cool season (November-March), extreme temperature events (ETEs) always hit the continental United States (US) and provide significant societal impacts. According to the anomalous amplitudes of the surface air temperature (SAT), there are two typical types of ETEs, e.g. cold waves (CWs) and warm waves (WWs). This study used cluster analysis to categorize both CWs and WWs into four distinct regimes respectively and investigated their associated large-scale circulations on intra-seasonal time scale. Most of the CW regimes have large areal impact over the continental US. However, the distribution of cold SAT anomalies varies apparently in four regimes. In the sea level, the four CW regimes are characterized by anomalous high pressure over North America (near and to west of cold anomaly) with different extension and orientation. As a result, anomalous northerlies along east flank of anomalous high pressure convey cold air into the continental US. To the middle troposphere, the leading two groups feature large-scale and zonally-elongated circulation anomaly pattern, while the other two regimes exhibit synoptic wavetrain pattern with meridionally elongated features. As for the WW regimes, there are some patterns symmetry and anti-symmetry with respect to CW regimes. The WW regimes are characterized by anomalous low pressure and southerlies wind over North America. The first and fourth groups are affected by remote forcing emanating from North Pacific, while the others appear mainly locally forced.

Exchange rate regimes and monetary arrangements

Directory of Open Access Journals (Sweden)

Ivan Ribnikar

2005-06-01

Full Text Available There is a close relationship between a country’s exchange rate regime and monetary arrangement and if we are to examine monetary arrangements then exchange rate regimes must first be analysed. Within the conventional and most widely used classification of exchange rate regimes into rigid and flexible or into polar regimes (hard peg and float on one side, and intermediate regimes on the other there, is a much greater variety among intermediate regimes. A more precise and, as will be seen, more useful classification of exchange rate regimes is the first topic of the paper. The second topic is how exchange rate regimes influence or determine monetary arrangements and monetary policy or monetary policy regimes: monetary autonomy versus monetary nonautonomy and discretion in monetary policy versus commitment in monetary policy. Both topics are important for countries on their path to the EU and the euro area

Hybrid inflation along waterfall trajectories

International Nuclear Information System (INIS)

Clesse, Sebastien

2011-01-01

We identify a new inflationary regime for which more than 60 e-folds are generated classically during the waterfall phase occurring after the usual hybrid inflation. By performing a Bayesian Monte-Carlo-Markov-Chain analysis, this scenario is shown to take place in a large part of the parameter space of the model. When this occurs, the observable perturbation modes leave the Hubble radius during waterfall inflation. The power spectrum of adiabatic perturbations is red, possibly in agreement with CMB constraints. Particular attention has been given to study only the regions for which quantum backreactions do not affect the classical dynamics. Implications concerning the preheating and the absence of topological defects in our Universe are discussed.

Rheological behavior of clay-nanoparticle hybrid-added bentonite suspensions: specific role of hybrid additives on the gelation of clay-based fluids.

Science.gov (United States)

Jung, Youngsoo; Son, You-Hwan; Lee, Jung-Kun; Phuoc, Tran X; Soong, Yee; Chyu, Minking K

2011-09-01

Two different types of clay nanoparticle hybrid, iron oxide nanoparticle clay hybrid (ICH) and Al(2)O(3)-SiO(2) nanoparticle clay hybrid (ASCH), were synthesized and their effects on the rheological properties of aqueous bentonite fluids in steady state and dynamic state were explored. When ICH particles were added, bentonite particles in the fluid cross-link to form relatively well-oriented porous structure. This is attributed to the development of positively charged edge surfaces in ICH that leads to strengthening of the gel structure of the bentonite susensions. The role of ASCH particles on the interparticle association of the bentonite fluids is different from that of ICH and sensitive to pH. As pH of ASCH-added bentonite suspensions increased, the viscosity, yield stress, storage modulus, and flow stress decreased. In contrast, at low pH, the clay suspensions containing ASCH additives were coagulated and their rheological properties become close to those of ICH added bentonite fluids. A correlation between the net surface charge of the hybrid additives and the rheological properties of the fluids indicates that the embedded nanoparticles within the interlayer space control the variable charge of the edge surfaces of the platelets and determine the particles association behavior of the clay fluids.

Improving polymer/nanocrystal hybrid solar cell performance via tuning ligand orientation at CdSe quantum dot surface.

Science.gov (United States)

Fu, Weifei; Wang, Ling; Zhang, Yanfang; Ma, Ruisong; Zuo, Lijian; Mai, Jiangquan; Lau, Tsz-Ki; Du, Shixuan; Lu, Xinhui; Shi, Minmin; Li, Hanying; Chen, Hongzheng

2014-11-12

Achieving superior solar cell performance based on the colloidal nanocrystals remains challenging due to their complex surface composition. Much attention has been devoted to the development of effective surface modification strategies to enhance electronic coupling between the nanocrystals to promote charge carrier transport. Herein, we aim to attach benzenedithiol ligands onto the surface of CdSe nanocrystals in the "face-on" geometry to minimize the nanocrystal-nanocrystal or polymer-nanocrystal distance. Furthermore, the "electroactive" π-orbitals of the benzenedithiol are expected to further enhance the electronic coupling, which facilitates charge carrier dissociation and transport. The electron mobility of CdSe QD films was improved 20 times by tuning the ligand orientation, and high performance poly[2,6-(4,4-bis(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b']-dithiophene)-alt-4,7-(2,1,3-benzothiadiazole)] (PCPDTBT):CdSe nanocrystal hybrid solar cells were also achieved, showing a highest power conversion efficiency of 4.18%. This research could open up a new pathway to improve further the performance of colloidal nanocrystal based solar cells.

A Third Generation Lower Hybrid Coupler

International Nuclear Information System (INIS)

Bernabei, S.; Hosea, J.; Kung, C.; Loesser, D.; Rushinski, J.; Wilson, J.R.; Parker, R.

2001-01-01

The Princeton Plasma Physics Laboratory (PPPL) and the Massachusetts Institute of Technology (MIT) are preparing an experiment of current profile control using lower-hybrid waves in order to produce and sustain advanced tokamak regimes in steady-state conditions in Alcator C-Mod. Unlike JET's, ToreSupra's and JT60's couplers, the C-Mod lower-hybrid coupler does not employ the now conventional multijunction design, but will have similar characteristics, compactness, and internal power division while retaining full control of the antenna element phasing. This is achieved by using 3 dB vertical power splitters and a stack of laminated plates with the waveguides milled in them. Construction is simplified and allows easy control and maintenance of all parts. Many precautions are taken to avoid arcing. Special care is also taken to avoid the recycling of reflected power which could affect the coupling and the launched n(subscript ||) spectrum. The results from C-Mod should allow further simplification in the designs of the coupler planned for KSTAR (Korea Superconducting Tokamak Advanced Research) and ITER (International Thermonuclear Experimental Reactor)

Hybrid nanocomposites based on electroactive hydrogels and cellulose nanocrystals for high-sensitivity electro-mechanical underwater actuation

Science.gov (United States)

Santaniello, Tommaso; Migliorini, Lorenzo; Locatelli, Erica; Monaco, Ilaria; Yan, Yunsong; Lenardi, Cristina; Comes Franchini, Mauro; Milani, Paolo

2017-08-01

We report the synthesis, fabrication and characterization of a hybrid hydrogel/cellulose nanocomposite, which exhibits high-performance electro-mechanical underwater actuation and high sensitivity in response to electrical stimuli below the standard potential of water electrolysis. The macromolecular structure of the material is constituted by an electroactive hydrogel, obtained through a photo-polymerization reaction with the use of three vinylic co-monomers: Na-4-vinylbenzenesulfonate, 2-hydroxyethylmethacrylate, and acrylonitrile. Different amounts (from 0.1% to 1.4% w/w) of biodegradable cellulose nanocrystals (CNCs) with sulfonate surface groups, obtained through the acidic hydrolysis of sulphite pulp lapsheets, are physically incorporated into the gel matrix during the synthesis step. Freestanding thin films of the nanocomposites are molded, and their swelling, mechanical and responsive properties are fully characterized. We observed that the embedding of the CNCs enhanced both the material Young’s modulus and its sensitivity to the applied electric field in the sub-volt regime (down to 5 mV cm-1). A demonstrator integrating multiple actuators that cooperatively bend together, mimicking the motion of an electro-valve, is also prototyped and tested. The presented nanocomposite is suitable for the development of soft smart components for bio-robotic applications and cells-based and bio-hybrid fluidic devices fabrication.

Causas estruturais e consequências dos regimes internacionais: regimes como variáveis intervenientes

OpenAIRE

Krasner, Stephen D.

2012-01-01

Os regimes internacionais são definidos como princípios, normas, regras e procedimentos de tomada de decisões ao redor dos quais as expectativas dos atores convergem em uma dada área-tema. Como ponto de partida, os regimes são conceituados como variáveis intervenientes, estando entre fatores causais básicos e os resultados e comportamentos relacionados. Há três visões a respeito da importância dos regimes: as orientações estruturais convencionais desvalorizam os regimes como sendo, na melhor ...

Quasi-Laminar Flow Characteristics in Hybrid-Stabilized Argon–Water Arc Discharge for Subsonic-Supersonic Regimes

Czech Academy of Sciences Publication Activity Database

Jeništa, Jiří; Takana, H.; Nishiyama, H.; Křenek, Petr; Bartlová, M.; Aubrecht, V.

2014-01-01

Roč. 42, č. 10 (2014), s. 2632-2633 ISSN 0093-3813 R&D Projects: GA ČR GAP205/11/2070 Institutional support: RVO:61389021 Keywords : Hybrid-stabilized electric arc * large-eddy simulation * partial characteristics * the Smagorinsky subgrid scale model Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.101, year: 2014 http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=6876210

Investigation of Υ Dor - δ Sct hybrid stars based on high precission space photometry and complementary ground based spectroscopy

International Nuclear Information System (INIS)

Hareter, M.

2013-01-01

Stellar pulsation carries information on the physical condition within the star. While pressure modes (p modes) probe the outer layers of a star, gravity modes (g modes) penetrate deep into the radiative zone and thus carry valuable information on the physical conditions there. gamma Dor stars are stars that pulsate in such modes, apart from white dwarfs and slowly pulsating B (SPB) stars. Therefore, these stars are important test benches for stellar evolution and pulsation theory. delta Sct - gamma Dor hybrids are stars that pulsate like gamma Dor stars with g modes but also with p modes as the delta Sct stars do. This makes them even more suited for asteroseismology. The CoRoT long runs offer a great opportunity to analyse a large sample of stars observed homogeneously, uninterrupted and long time base of about 150 days, which is practically unachievable with ground based observation. Since space missions avoid the scintillation caused by the Earth's atmosphere, they allow to detect stellar oscillations on a sub-millimagnitude level even for stars as faint as 15th magnitude. The photometric data is supplemented by AAOmega classification spectroscopy, allowing to determine effective tem- peratures and surface gravity. With these data a statistical approach was adopted to describe the pulsation behaviour gamma Dor and delta Sct - gamma Dor hybrid stars. A temperature - period relation was found for gamma Dor and delta Sct stars, but none for delta Sct - gamma Dor hybrid stars, when considering their strongest g mode or p mode, respectively. The instability domain of hybrid stars is equal to that of delta Sct stars and is not con- fined to the overlapping region of the delta Sct and gamma Dor IS in the Hertzsprung- Russell diagram. Hybrid stars behave differently in the g mode regime than gamma Dor stars, which poses a serious question on how to define properly a delta Sct - gamma Dor hybrid. The convective flux blocking mechanism is supposed to work for stars

Hybrid rail gun electromagnetic accelerators

International Nuclear Information System (INIS)

Chen, K.W.; Hachen, H.; Lee, A.; Legh, G.; Lin, T.; Mattay, S.; Wipf, S.

1983-01-01

Theoretical and experimental investigations on hybrid rail accelerators are presented. It is shown that the side surface areas and in some cases sabots of the projectile can be used to provide substantial amount of additional thrust. Moreover, it is shown that in most cases examined, external magnetic fields can be conveniently incorporated in the accelerator designs to supplement the rail-induced fields. Total thrusts in excess of 10 MN for kilogram-sized projectiles can in principle be established with driving currents of the order of 1 MA. No obvious stress limitations are foreseen. The percentages of thrust from external magnetic fields are sufficiently high that the use of which should be encouraged. The increased flexibility in the projectile shapes available permits the use of the proposed hybrid electromagnetic launcher technology in a variety of new areas, such as thrust boosts in conventional chemical rockets and other similar applications. Furthermore, the additional thrust obtained from the use of side surface areas greatly increases the maximum permissable thrust otherwise limited by material strength considerations. Thrust analyses for projectiles in several hybrid rail accelerator designs are discussed. Some laboratory experimental observations are presented

Study of laser-induced damage on the exit surface of silica components in the nanosecond regime in a multiple wavelengths configuration

International Nuclear Information System (INIS)

Chambonneau, Maxime

2014-01-01

In this thesis, laser-induced damage phenomenon on the surface of fused silica components is investigated in the nanosecond regime. This phenomenon consists in an irreversible modification of the material. In the nanosecond regime, laser damage is tightly correlated to the presence of non-detectable precursor defects which are a consequence of the synthesis and the polishing of the components. In this thesis, we investigate laser damage in a multiple wavelengths configuration. In order to better understand this phenomenon in these conditions of irradiation, three studies are conducted. The first one focuses on damage initiation. The results obtained in the single wavelength configurations highlight a coupling in the multiple wavelengths one. A comparison between the experiments and a model developed during this thesis enables us to improve the knowledge of the fundamental processes involved during this damage phase. Then, we show that post mortem characterizations of damage morphology coupled to an accurate metrology allow us to understand both the nature and also the chronology of the physical mechanisms involved during damage formation. The proposed theoretical scenario is confirmed through various experiments. Finally, we study damage growth in both the single and the multiple wavelengths cases. Once again, this last configuration highlights a coupling between the wavelengths. We show the necessity to account for the spatial characteristics of the laser beams during a growth session. (author) [fr

A Novel Method for Rapid Hybridization of DNA to a Solid Support

Science.gov (United States)

Pettersson, Erik; Ahmadian, Afshin; Ståhl, Patrik L.

2013-01-01

Here we present a novel approach entitled Magnetic Forced Hybridization (MFH) that provides the means for efficient and direct hybridization of target nucleic acids to complementary probes immobilized on a glass surface in less than 15 seconds at ambient temperature. In addition, detection is carried out instantly since the beads become visible on the surface. The concept of MFH was tested for quality control of array manufacturing, and was combined with a multiplex competitive hybridization (MUCH) approach for typing of Human Papilloma Virus (HPV). Magnetic Forced Hybridization of bead-DNA constructs to a surface achieves a significant reduction in diagnostic testing time. In addition, readout of results by visual inspection of the unassisted eye eliminates the need for additional expensive instrumentation. The method uses the same set of beads throughout the whole process of manipulating and washing DNA constructs prior to detection, as in the actual detection step itself. PMID:23950946

The Role of Structural Enthalpy in Spherical Nucleic Acid Hybridization.

Science.gov (United States)

Fong, Lam-Kiu; Wang, Ziwei; Schatz, George C; Luijten, Erik; Mirkin, Chad A

2018-05-23

DNA hybridization onto DNA-functionalized nanoparticle surfaces (e.g., in the form of a spherical nucleic acid (SNA)) is known to be enhanced relative to hybridization free in solution. Surprisingly, via isothermal titration calorimetry, we reveal that this enhancement is enthalpically, as opposed to entropically, dominated by ∼20 kcal/mol. Coarse-grained molecular dynamics simulations suggest that the observed enthalpic enhancement results from structurally confining the DNA on the nanoparticle surface and preventing it from adopting enthalpically unfavorable conformations like those observed in the solution case. The idea that structural confinement leads to the formation of energetically more stable duplexes is evaluated by decreasing the degree of confinement a duplex experiences on the nanoparticle surface. Both experiment and simulation confirm that when the surface-bound duplex is less confined, i.e., at lower DNA surface density or at greater distance from the nanoparticle surface, its enthalpy of formation approaches the less favorable enthalpy of duplex formation for the linear strand in solution. This work provides insight into one of the most important and enabling properties of SNAs and will inform the design of materials that rely on the thermodynamics of hybridization onto DNA-functionalized surfaces, including diagnostic probes and therapeutic agents.

Polyacrylamide-based inorganic hybrid flocculants with self-degradable property

Energy Technology Data Exchange (ETDEWEB)

Wei, Xinfang [Materials and Metallurgical College, Northeastern University, Shenyang 110819 (China); Hebei Provincial Laboratory for Dielectric and Electrolyte Materials, Northeastern University at Qinhuangdao, Qinhuangdao 066004 (China); Tao, Junshi; Li, Mingzhi; Zhu, Bishan; Li, Xuan; Ma, Zhiyu; Zhao, Tingjie; Wang, Bingzhu; Suo, Biao [Hebei Provincial Laboratory for Dielectric and Electrolyte Materials, Northeastern University at Qinhuangdao, Qinhuangdao 066004 (China); Wang, Haiwang, E-mail: whwdbdx@126.com [Materials and Metallurgical College, Northeastern University, Shenyang 110819 (China); State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China); Hebei Provincial Laboratory for Dielectric and Electrolyte Materials, Northeastern University at Qinhuangdao, Qinhuangdao 066004 (China); Yang, Jun, E-mail: jyang@ipe.ac.cn [State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Ye, Li, E-mail: yeli@iccas.ac.cn [Beijing National Laboratory for Molecular Sciences, Institute of Chemistry Chinese Academy of Sciences, Beijing 100190 (China); Qi, Xiwei, E-mail: qxw@mail.neuq.edu.cn [Materials and Metallurgical College, Northeastern University, Shenyang 110819 (China); Hebei Provincial Laboratory for Dielectric and Electrolyte Materials, Northeastern University at Qinhuangdao, Qinhuangdao 066004 (China)

2017-05-01

Polyacrylamide (PAM)-based inorganic hybrid materials are of great potential as flocculants in soil-liquid separation. Herein, we reported the design of inorganic soil-TiO{sub 2}-PAM hybrid materials using a unique process, which involved coating of titanium dioxide (TiO{sub 2}) nanoparticles on the surface of inorganic soils and subsequent polymerization of acrylamide (AM) on these nanoparticles under visible light. Inorganic soils including kaolin, bentonite, montmorillonite and diatomaceous earth were used to control the volume and to reduce the cost, and the TiO{sub 2} nanoparticles accelerated PAM degradation. The nanoparticles initiated AM polymerization directly under visible light, thus providing a facile strategy for the synthesis of new organic-inorganic hybrid flocculants. The obtained hybrid materials were characterized using Fourier transform infrared spectroscopy and transmission electron microscopy. The degradation of PAM initiated by UV irradiation exceeded 24% in 2 h, depending on its initial concentration. - Highlights: • A new polyacrylamide (PAM)-based inorganic hybrid flocculants with self-degradable property was developed. • TiO{sub 2} nanoparticles show a unique surface-initiated property under the condition of visible light. • We designed a facile strategy for the synthesis of inorganic soil@TiO{sub 2}@PAM hybrid materials.

Sensitivity to spatial and temporal scale and fire regime inputs in deriving fire regime condition class

Science.gov (United States)

Linda Tedrow; Wendel J. Hann

2015-01-01

The Fire Regime Condition Class (FRCC) is a composite departure measure that compares current vegetation structure and fire regime to historical reference conditions. FRCC is computed as the average of: 1) Vegetation departure (VDEP) and 2) Regime (frequency and severity) departure (RDEP). In addition to the FRCC rating, the Vegetation Condition Class (VCC) and Regime...

Exploration of extremely low q_e_d_g_e regime in KSTAR

International Nuclear Information System (INIS)

Kim, Jayhyun; In, Y.; Park, B.H.; Aydemir, A.

2015-01-01

The q_e_d_g_e < 2 regime had long been regarded as an experimentally forbidden regime due to magneto-hydrodynamic instabilities. However, RFX-MOD experiment demonstrated that the control of error field could enable the entrance and sustainment of the discharge even in the forbidden regime. We explored q_e_d_g_e < 2 regime in Korea superconducting tokamak advanced research (KSTAR) without any feedback or feedforward control of error field since the intrinsic level of error field in KSTAR is inherently comparable to the controlled level of other device. The discharge sustained at q_9_5 ∼ 1.9 for 800 ms that is at least one order of magnitude longer than the resistive wall time of the device. Furthermore, simulated error field applied by field error correction coils prevented the passage of q_e_d_g_e = 3 integer rational surface before reaching q_e_d_g_e = 2. The detailed analysis is on-going for revealing the role of error field in the excitation of limiting instability. (author)

Surface tailoring of newly developed amorphous Znsbnd Sisbnd O thin films as electron injection/transport layer by plasma treatment: Application to inverted OLEDs and hybrid solar cells

Science.gov (United States)

Yang, Hongsheng; Kim, Junghwan; Yamamoto, Koji; Xing, Xing; Hosono, Hideo

2018-03-01

We report a unique amorphous oxide semiconductor Znsbnd Sisbnd O (a-ZSO) which has a small work function of 3.4 eV for as-deposited films. The surface modification of a-ZSO thin films by plasma treatments is examined to apply it to the electron injection/transport layer of organic devices. It turns out that the energy alignment and exciton dissociation efficiency at a-ZSO/organic semiconductor interface significantly changes by choosing different gas (oxygen or argon) for plasma treatments (after a-ZSO was exposed to atmospheric environment for 5 days). In situ ultraviolet photoelectron spectroscopy (UPS) measurement reveals that the work function of a-ZSO is increased to 4.0 eV after an O2-plasma treatment, while the work function of 3.5 eV is recovered after an Ar-plasma treatment which indicates this treatment is effective for surface cleaning. To study the effects of surface treatments to device performance, OLEDs and hybrid polymer solar cells with O2-plasma or Ar-plasma treated a-ZSO are compared. Effects of these surface treatments on performance of inverted OLEDs and hybrid polymer solar cells are examined. Ar-plasma treated a-ZSO works well as the electron injection layer in inverted OLEDs (Alq3/a-ZSO) because the injection barrier is small (∼ 0.1 eV). On the other hands, O2-plasma treated a-ZSO is more suitable for application to hybrid solar cells which is benefiting from higher exciton dissociation efficiency at polymer (P3HT)/ZSO interface.

The Surface of Hybrid Perovskite Crystals: A Boon or Bane

KAUST Repository

Banavoth, Murali; Yengel, Emre; Yang, Chen; Peng, Wei; Alarousu, Erkki; Bakr, Osman; Mohammed, Omar F.

2017-01-01

Hybrid perovskite single crystals have garnered tremendous research attention and are expected to be next-generation materials for high-efficiency photoactive devices. Therefore, it is fundamentally important to understand the 8 relationship between

Hybridization thermodynamics of DNA bound to gold nanoparticles

International Nuclear Information System (INIS)

Lang, Brian

2010-01-01

Isothermal Titration Calorimetry (ITC) was used to study the thermodynamics of hybridization on DNA-functionalized colloidal gold nanoparticles. When compared to the thermodynamics of hybridization of DNA that is free in solution, the differences in the values of the Gibbs free energy of reaction, Δ r G o , the enthalpy, Δ r H o , and entropy, Δ r S o , were small. The change in Δ r G o between the free and bound states was always positive but with statistical significance outside the 95% confidence interval, implying the free DNA is slightly more stable than when in the bound state. Additionally, ITC was also able to reveal information about the binding stoichiometry of the hybridization reactions on the DNA-functionalized gold nanoparticles, and indicates that there is a significant fraction of the DNA on gold nanoparticle surface that is unavailable for DNA hybridization. Furthermore, the fraction of available DNA is dependent on the spacer group on the DNA that is used to span the gold surface from that to the probe DNA.

Majority ion heating near the ion-ion hybrid layer in tokamaks

International Nuclear Information System (INIS)

Phillips, C.K.; Hosea, J.C.; Ignat, D.; Majeski, R.; Rogers, J.H.; Schilling, G.; Wilson, J.R.

1995-08-01

Efficient direct majority ion heating in a deuterium-tritium (D-T) reactor-grade plasma via absorption of fast magnetosonic waves in the ion cyclotron range of frequencies (ICRF) is discussed. Majority ion heating results from resonance overlap between the cyclotron layers and the D-T ion-ion hybrid layer in hot, dense plasmas for fast waves launched with high parallel wavenumbers. Analytic and numerical models are used to explore the regime in ITER plasmas

Hybrid electrokinetics for separation, mixing, and concentration of colloidal particles

International Nuclear Information System (INIS)

Sin, Mandy L Y; Shimabukuro, Yusuke; Wong, Pak Kin

2009-01-01

The advent of nanotechnology has facilitated the preparation of colloidal particles with adjustable sizes and the control of their size-dependent properties. Physical manipulation, such as separation, mixing, and concentration, of these colloidal particles represents an essential step for fully utilizing their potential in a wide spectrum of nanotechnology applications. In this study, we investigate hybrid electrokinetics, the combination of dielectrophoresis and electrohydrodynamics, for active manipulation of colloidal particles ranging from nanometers to micrometers in size. A concentric electrode configuration, which is optimized for generating electrohydrodynamic flow, has been designed to elucidate the effectiveness of hybrid electrokinetics and define the operating regimes for different microfluidic operations. The results indicate that the relative importance of electrohydrodynamics increases with decreasing particle size as predicted by a scaling analysis and that electrohydrodynamics is pivotal for manipulating nanoscale particles. Using the concentric electrodes, we demonstrate separation, mixing, and concentration of colloidal particles by adjusting the relative strengths of different electrokinetic phenomena. The effectiveness of hybrid electrokinetics indicates its potential to serve as a generic technique for active manipulation of colloidal particles in various nanotechnology applications.

Small-scale hybrid plant integrated with municipal energy supply system

International Nuclear Information System (INIS)

Bakken, B.H.; Fossum, M.; Belsnes, M.M.

2001-01-01

This paper describes a research program started in 2001 to optimize environmental impact and cost of a small-scale hybrid plant based on candidate resources, transportation technologies and conversion efficiency, including integration with existing energy distribution systems. Special attention is given to a novel hybrid energy concept fuelled by municipal solid waste. The commercial interest for the model is expected to be more pronounced in remote communities and villages, including communities subject to growing prosperity. To enable optimization of complex energy distribution systems with multiple energy sources and carriers a flexible and robust methodology must be developed. This will enable energy companies and consultants to carry out comprehensive feasibility studies prior to investment, including technological, economic and environmental aspects. Governmental and municipal bodies will be able to pursue scenario studies involving energy systems and their impact on the environment, and measure the consequences of possible regulation regimes on environmental questions. This paper describes the hybrid concept for conversion of municipal solid waste in terms of energy supply, as well as the methodology for optimizing such integrated energy systems. (author)

Sympathetic cooling of ions in a hybrid atom ion trap

Energy Technology Data Exchange (ETDEWEB)

Hoeltkemeier, Bastian

2016-10-27

In this thesis the dynamics of a trapped ion immersed in a spatially localized buffer gas is investigated. For a homogeneous buffer gas, the ion's energy distribution reaches a stable equilibrium only if the mass of the buffer gas atoms is below a critical value. This limitation can be overcome by using multipole traps in combination and/or a spatially confined buffer gas. Using a generalized model for elastic collisions of the ion with the buffer gas atoms, the ion's energy distribution is numerically determined for arbitrary buffer gas distributions and trap parameters. Three regimes characterized by the respective analytic form of the ion's equilibrium energy distribution are found. One of these is a novel regime at large atom-to-ion mass ratios where the final ion temperature can tuned by adiabatically decreasing the spatial extension of the buffer gas and the effective ion trap depth (forced sympathetic cooling). The second part of the thesis presents a hybrid atom ion trap designed for sympathetic cooling of hydroxide anions. In this hybrid trap the anions are immersed in a cloud of laser cooled rubidium atoms. The translational and rovibrational temperatures of the anions is probed by photodetachment tomography and spectroscopy which shows the first ever indication of sympathetic cooling of anions by laser cooled atoms.

The Comparative Study on Vapor-Polymerization and Pressure-dependent Conductance Behavior in Polypyrrole-hybridized Membranes

Energy Technology Data Exchange (ETDEWEB)

Hanif, Zahid; Lee, Seyeong; Arsalani, Nasir; Geckeler, Kurt E.; Hong, Sukwon; Yoon, Myung-Han [Gwangju Institute of Science and Technology, Gwangju (Korea, Republic of)

2016-02-15

In this study, commercially available cellulose membranes were hybridized with conjugated polymer via vapor-phase polymerization using pyrrole and iron chloride as a monomer and oxidant, respectively. The iron (III) chloride layer dip-coated on the hydrophilic cell ulose surface oxidized the vaporized pyrrole monomer leading to the polypyrrole-cellulose hybrid membrane. The conductivity of hybrid membrane was optimized by varying the oxidant concentration and the monomer vapor exposure time. The various surface characterizations of polypyrrole-cellulose hybrid membrane show that the conductive polypyrrole layer was uniformly deposited onto the surface of cellulose fibrous networks unlike the polypyrrole-nylonhybrid membrane prepared in the similar way. The polypyrrole-incorporated cellulose networks exhibits steeper electrical conductance increase over the vertical pressure than its nylon counterpart. Our result suggests that the polypyrrole-cellulose hybrid membrane can be applicable for a disposable high-load pressure sensor.

The Comparative Study on Vapor-Polymerization and Pressure-dependent Conductance Behavior in Polypyrrole-hybridized Membranes

International Nuclear Information System (INIS)

Hanif, Zahid; Lee, Seyeong; Arsalani, Nasir; Geckeler, Kurt E.; Hong, Sukwon; Yoon, Myung-Han

2016-01-01

In this study, commercially available cellulose membranes were hybridized with conjugated polymer via vapor-phase polymerization using pyrrole and iron chloride as a monomer and oxidant, respectively. The iron (III) chloride layer dip-coated on the hydrophilic cell ulose surface oxidized the vaporized pyrrole monomer leading to the polypyrrole-cellulose hybrid membrane. The conductivity of hybrid membrane was optimized by varying the oxidant concentration and the monomer vapor exposure time. The various surface characterizations of polypyrrole-cellulose hybrid membrane show that the conductive polypyrrole layer was uniformly deposited onto the surface of cellulose fibrous networks unlike the polypyrrole-nylonhybrid membrane prepared in the similar way. The polypyrrole-incorporated cellulose networks exhibits steeper electrical conductance increase over the vertical pressure than its nylon counterpart. Our result suggests that the polypyrrole-cellulose hybrid membrane can be applicable for a disposable high-load pressure sensor.

Surface engineering of macrophages with nanoparticles to generate a cell-nanoparticle hybrid vehicle for hypoxia-targeted drug delivery.

Science.gov (United States)

Holden, Christopher A; Yuan, Quan; Yeudall, W Andrew; Lebman, Deborah A; Yang, Hu

2010-02-02

Tumors frequently contain hypoxic regions that result from a shortage of oxygen due to poorly organized tumor vasculature. Cancer cells in these areas are resistant to radiation- and chemotherapy, limiting the treatment efficacy. Macrophages have inherent hypoxia-targeting ability and hold great advantages for targeted delivery of anticancer therapeutics to cancer cells in hypoxic areas. However, most anticancer drugs cannot be directly loaded into macrophages because of their toxicity. In this work, we designed a novel drug delivery vehicle by hybridizing macrophages with nanoparticles through cell surface modification. Nanoparticles immobilized on the cell surface provide numerous new sites for anticancer drug loading, hence potentially minimizing the toxic effect of anticancer drugs on the viability and hypoxia-targeting ability of the macrophage vehicles. In particular, quantum dots and 5-(aminoacetamido) fluorescein-labeled polyamidoamine dendrimer G4.5, both of which were coated with amine-derivatized polyethylene glycol, were immobilized to the sodium periodate-treated surface of RAW264.7 macrophages through a transient Schiff base linkage. Further, a reducing agent, sodium cyanoborohydride, was applied to reduce Schiff bases to stable secondary amine linkages. The distribution of nanoparticles on the cell surface was confirmed by fluorescence imaging, and it was found to be dependent on the stability of the linkages coupling nanoparticles to the cell surface.

Spectroscopic characterizations of individual single-crystalline GaN nanowires in visible/ultra-violet regime.

Science.gov (United States)

Wu, Chien-Ting; Chu, Ming-Wen; Chen, Li-Chyong; Chen, Kuei-Hsien; Chen, Chun-Wei; Chen, Cheng Hsuan

2010-10-01

Spectroscopic investigations of individual single-crystalline GaN nanowires with a lateral dimensions of approximately 30-90nm were performed using the spatially resolved technique of electron energy-loss spectroscopy in conjunction with scanning transmission electron microscope showing a 2-A electron probe. Positioning the electron probe upon transmission impact and at aloof setup with respect to the nanomaterials, we explored two types of surface modes intrinsic to GaN, surface exciton polaritons at approximately 8.3eV (approximately 150nm) and surface guided modes at 3.88eV (approximately 320nm), which are in visible/ultra-violet spectral regime above GaN bandgap of approximately 3.3eV (approximately 375nm) and difficult to access by conventional optical spectroscopies. The explorations of these electromagnetic resonances might expand the current technical interests in GaN nanomaterials from the visible/UV range below approximately 3.5eV to the spectral regime further beyond.

Multi-scale friction modeling for sheet metal forming: the boundary lubrication regime

NARCIS (Netherlands)

Hol, J.D.; Meinders, Vincent T.; de Rooij, Matthias B.; van den Boogaard, Antonius H.

2015-01-01

A physical based friction model is presented to describe friction in full-scale forming simulations. The advanced friction model accounts for the change in surface topography and the evolution of friction in the boundary lubrication regime. The implementation of the friction model in FE software

Hybrid anode for semiconductor radiation detectors

Science.gov (United States)

Yang, Ge; Bolotnikov, Aleksey E; Camarda, Guiseppe; Cui, Yonggang; Hossain, Anwar; Kim, Ki Hyun; James, Ralph B

2013-11-19

The present invention relates to a novel hybrid anode configuration for a radiation detector that effectively reduces the edge effect of surface defects on the internal electric field in compound semiconductor detectors by focusing the internal electric field of the detector and redirecting drifting carriers away from the side surfaces of the semiconductor toward the collection electrode(s).

Ternary Surface Monolayers for Ultrasensitive (Zeptomole) Amperometric Detection of Nucleic-Acid Hybridization without Signal Amplification

Science.gov (United States)

Wu, Jie; Campuzano, Susana; Halford, Colin; Haake, David A.; Wang, Joseph

2010-01-01

A ternary surface monolayer, consisting of co-assembled thiolated capture probe (SHCP) mercaptohexanol (MCH) and dithiothreitol (DTT), is shown to offer dramatic improvements in the signal-to-noise characteristics of electrochemical DNA hybridization biosensors based on common self-assembled monolayers (SAMs). Remarkably low detection limits down to 40 zmole (in 4 μL samples) as well as only 1 CFU E. coli per sensor are thus obtained without any additional amplification step in connection to the commonly used horseradish peroxidase/3,3′,5,5′-tetramethylbenzidine (HRP/TMB) system. Such dramatic improvements in the detection limits (compared to common binary alkanethiol interfaces and to most electrochemical DNA sensing strategies without target or signal amplification) are attributed primarily to the remarkably higher resistance to non-specific adsorption. This reflects the highly compact layer (with lower pinhole density) produced by the coupling of the cyclic- and linear-configuration ‘backfillers’ that leads to a remarkably low background noise even in the presence of complex sample matrices. A wide range of surface compositions have been investigated and the ternary mixed monolayer has been systematically optimized. Detailed impedance spectroscopy and cyclic voltammetric studies shed useful insights into the surface coverage. The impressive sensitivity and high specificity of the simple developed methodology indicate great promise for a wide range of nucleic acid testing, including clinical diagnostics, biothreat detection, food safety and forensic analysis. PMID:20883023

Ternary surface monolayers for ultrasensitive (zeptomole) amperometric detection of nucleic acid hybridization without signal amplification.

Science.gov (United States)

Wu, Jie; Campuzano, Susana; Halford, Colin; Haake, David A; Wang, Joseph

2010-11-01

A ternary surface monolayer, consisting of coassembled thiolated capture probe, mercaptohexanol and dithiothreitol, is shown to offer dramatic improvements in the signal-to-noise characteristics of electrochemical DNA hybridization biosensors based on common self-assembled monolayers. Remarkably low detection limits down to 40 zmol (in 4 μL samples) as well as only 1 CFU Escherichia coli per sensor are thus obtained without any additional amplification step in connection to the commonly used horseradish peroxidase/3,3',5,5'-tetramethylbenzidine system. Such dramatic improvements in the detection limits (compared to those of common binary alkanethiol interfaces and to those of most electrochemical DNA sensing strategies without target or signal amplification) are attributed primarily to the remarkably higher resistance to nonspecific adsorption. This reflects the highly compact layer (with lower pinhole density) produced by the coupling of the cyclic- and linear-configuration "backfillers" that leads to a remarkably low background noise even in the presence of complex sample matrixes. A wide range of surface compositions have been investigated, and the ternary mixed monolayer has been systematically optimized. Detailed impedance spectroscopy and cyclic voltammetric studies shed useful insights into the surface coverage. The impressive sensitivity and high specificity of the simple developed methodology indicate great promise for a wide range of nucleic acid testing, including clinical diagnostics, biothreat detection, food safety, and forensic analysis.

Ultrafast all-optical switching and error-free 10 Gbit/s wavelength conversion in hybrid InP-silicon on insulator nanocavities using surface quantum wells

Energy Technology Data Exchange (ETDEWEB)

Bazin, Alexandre; Monnier, Paul; Beaudoin, Grégoire; Sagnes, Isabelle; Raj, Rama [Laboratoire de Photonique et de Nanostructures (CNRS UPR20), Route de Nozay, Marcoussis 91460 (France); Lenglé, Kevin; Gay, Mathilde; Bramerie, Laurent [Université Européenne de Bretagne (UEB), 5 Boulevard Laënnec, 35000 Rennes (France); CNRS-Foton Laboratory (UMR 6082), Enssat, BP 80518, 22305 Lannion Cedex (France); Braive, Rémy; Raineri, Fabrice, E-mail: fabrice.raineri@lpn.cnrs.fr [Laboratoire de Photonique et de Nanostructures (CNRS UPR20), Route de Nozay, Marcoussis 91460 (France); Université Paris Diderot, Sorbonne Paris Cité, 75207 Paris Cedex 13 (France)

2014-01-06

Ultrafast switching with low energies is demonstrated using InP photonic crystal nanocavities embedding InGaAs surface quantum wells heterogeneously integrated to a silicon on insulator waveguide circuitry. Thanks to the engineered enhancement of surface non radiative recombination of carriers, switching time is obtained to be as fast as 10 ps. These hybrid nanostructures are shown to be capable of achieving systems level performance by demonstrating error free wavelength conversion at 10 Gbit/s with 6 mW switching powers.

Carboxylated nitrile butadiene rubber/hybrid filler composites

Directory of Open Access Journals (Sweden)

Ahmad Mousa

2012-08-01

Full Text Available The surface properties of the OSW and NLS are measured with the dynamic contact-angle technique. The x-ray photoelectron spectroscopy (XPS of the OSW reveals that the OSW possesses various reactive functional groups namely hydroxyl groups (OH. Hybrid filler from NLS and OSW were incorporated into carboxylated nitrile rubber (XNBR to produce XNBR hybrid composites. The reaction of OH groups from the OSW with COOH of the XNBR is checked by attenuated total reflectance spectra (ATR-IR of the composites. The degree of curing ΔM (maximum torque-minimum torque as a function of hybrid filler as derived from moving die rheometer (MDR is reported. The stress-strain behavior of the hybrid composites as well as the dynamic mechanical thermal analysis (DMTA is studied. Bonding quality and dispersion of the hybrid filler with and in XNBR are examined using scanning-transmission electron microscopy (STEM in SEM.

Chromate-free Hybrid Coating for Corrosion Protection of Electrogalvanized Steel Sheets

International Nuclear Information System (INIS)

Jo, Duhwan; Kwon, Moonjae; Kim, Jongsang

2012-01-01

Both electrogalvanized and hot-dip galvanized steel sheets have been finally produced via organic-inorganic surface coating process on the zinc surface to enhance corrosion resistance and afford additional functional properties. Recently, POSCO has been developed a variety of chromate-free coated steels that are widely used in household, construction and automotive applications. New organic-inorganic hybrid coating solutions as chromate alternatives are comprised of surface modified silicate with silane coupling agent and inorganic corrosion inhibitors as an aqueous formulation. In this paper we have prepared new type of hybrid coatings and evaluated quality performances such as corrosion resistance, spot weldability, thermal tolerance, and paint adhesion property etc. The electrogalvanized steels with these coating solutions exhibit good anti-corrosion property compared to those of chromate coated steels. Detailed components composition of coating solutions and experimental results suggest that strong binding between organic-inorganic hybrid coating layer and zinc surface plays a key role in the advanced quality performances

An Investigation of a Hybrid Mixing Timescale Model for PDF Simulations of Turbulent Premixed Flames

Science.gov (United States)

Zhou, Hua; Kuron, Mike; Ren, Zhuyin; Lu, Tianfeng; Chen, Jacqueline H.

2016-11-01

Transported probability density function (TPDF) method features the generality for all combustion regimes, which is attractive for turbulent combustion simulations. However, the modeling of micromixing due to molecular diffusion is still considered to be a primary challenge for TPDF method, especially in turbulent premixed flames. Recently, a hybrid mixing rate model for TPDF simulations of turbulent premixed flames has been proposed, which recovers the correct mixing rates in the limits of flamelet regime and broken reaction zone regime while at the same time aims to properly account for the transition in between. In this work, this model is employed in TPDF simulations of turbulent premixed methane-air slot burner flames. The model performance is assessed by comparing the results from both direct numerical simulation (DNS) and conventional constant mechanical-to-scalar mixing rate model. This work is Granted by NSFC 51476087 and 91441202.

Heavy metals adsorption by novel EDTA-modified chitosan-silica hybrid materials.

Science.gov (United States)

Repo, Eveliina; Warchoł, Jolanta K; Bhatnagar, Amit; Sillanpää, Mika

2011-06-01

Novel adsorbents were synthesized by functionalizing chitosan-silica hybrid materials with (ethylenediaminetetraacetic acid) EDTA ligands. The synthesized adsorbents were found to combine the advantages of both silica gel (high surface area, porosity, rigid structure) and chitosan (surface functionality). The Adsorption potential of hybrid materials was investigated using Co(II), Ni(II), Cd(II), and Pb(II) as target metals by varying experimental conditions such as pH, contact time, and initial metal concentration. The kinetic results revealed that the pore diffusion process played a key role in adsorption kinetics, which might be attributed to the porous structure of synthesized adsorbents. The obtained maximum adsorption capacities of the hybrid materials for the metal ions ranged from 0.25 to 0.63 mmol/g under the studied experimental conditions. The adsorbent with the highest chitosan content showed the best adsorption efficiency. Bi-Langmuir and Sips isotherm model fitting to experimental data suggested the surface heterogeneity of the prepared adsorbents. In multimetal solutions, the hybrid adsorbents showed the highest affinity toward Pb(II). Copyright © 2011 Elsevier Inc. All rights reserved.

Numerical Study on Bubble Dynamics and Two-Phase Frictional Pressure Drop of Slug Flow Regime in Adiabatic T-junction Square Microchannel

Directory of Open Access Journals (Sweden)

K. Kishor

2017-10-01

Full Text Available In this study, bubble dynamics and frictional pressure drop associated with gas liquid two-phase slug flow regime in adiabatic T-junction square microchannel has been investigated using CFD. A comprehensive study on the mechanism of bubble formation via squeezing and shearing regime is performed. The randomness and recirculation profiles observed in the squeezing regime are significantly higher as compared to the shearing regime during formation of the slug. Further, effects of increasing gas velocity on bubble length are obtained at fixed liquid velocities and simulated data displayed good agreement with available correlations in literature. The frictional pressure drop for slug flow regime from simulations are also obtained and evaluated against existing separated flow models. A regression correlation has also been developed by modifying C-parameter using separated flow model, which improves the prediction of two-phase frictional pressure drop data within slug flow region, with mean absolute error of 10 %. The influences of fluid properties such as liquid viscosity and surface tension on the two-phase frictional pressure drop are also investigated and compared with developed correlation. The higher liquid viscosity and lower surface tension value resulted in bubble formation via shearing regime.

Strengthening the nuclear non-proliferation regime

International Nuclear Information System (INIS)

Carlson, J.

2003-01-01

Although the nuclear non-proliferation regime has enjoyed considerable success, today the regime has never been under greater threat. Three states have challenged the objectives of the NPT, and there is a technology challenge - the spread of centrifuge enrichment technology and know-how. A major issue confronting the international community is, how to deal with a determined proliferator? Despite this gloomy scenario, however, the non-proliferation regime has considerable strengths - many of which can be developed further. The regime comprises complex interacting and mutually reinforcing elements. At its centre is the NPT - with IAEA safeguards as the Treaty's verification mechanism. Important complementary elements include: restraint in the supply and the acquisition of sensitive technologies; multilateral regimes such as the CTBT and proposed FMCT; various regional and bilateral regimes; the range of security and arms control arrangements outside the nuclear area (including other WMD regimes); and the development of proliferation-resistant technologies. Especially important are political incentives and sanctions in support of non-proliferation objectives. This paper outlines some of the key issues facing the non-proliferation regime

Autonomia e relevância dos regimes The autonomy and relevance of regimes

Directory of Open Access Journals (Sweden)

Gustavo Seignemartin de Carvalho

2005-12-01

Full Text Available Teorias institucionalistas na disciplina de relações internacionais usualmente definem regimes como um conjunto de normas e regras formais ou informais que permitem a convergência de expectativas ou a padronização do comportamento de seus participantes em uma determinada área de interesses com o objetivo de resolver problemas de coordenação que tenderiam a resultados não pareto-eficientes. Como estas definições baseadas meramente na "eficiência" dos regimes não parecem suficientes para explicar sua efetividade, o presente artigo propõe uma definição diferente para regimes: a de arranjos políticos que permitem a redistribuição dos ganhos da cooperação pelos participantes em uma determinada área de interesses em um contexto de interdependência. Regimes possuiriam efetividade pela sua autonomia e relevância, ou seja, por possuírem existência objetiva autônoma da de seus participantes e por influenciarem seu comportamento e expectativas de maneiras que não podem ser reduzidas à ação individual de nenhum deles. O artigo inicia-se com uma breve discussão sobre as dificuldades terminológicas associadas ao estudo de regimes e a definição dos conceitos de autonomia e relevância. Em seguida, classifica os diversos autores participantes do debate em duas perspectivas distintas, uma que nega (não-autonomistas e outra que atribui (autonomistas aos regimes autonomia e relevância, e faz uma breve análise dos autores e tradições mais significativos para o debate, aprofundando-se nos autonomistas e nos argumentos que reforçam a hipótese aqui apresentada. Ao final, o artigo propõe uma decomposição analítica dos regimes nos quatro elementos principais que lhes propiciam autonomia e relevância: normatividade, atores, especificidade da área de interesses e interdependência complexa com o contexto.Regimes are defined by institutionalist theories in the discipline of International Relations as formal or informal sets

An Investigation of a Hybrid Mixing Model for PDF Simulations of Turbulent Premixed Flames

Science.gov (United States)

Zhou, Hua; Li, Shan; Wang, Hu; Ren, Zhuyin

2015-11-01

Predictive simulations of turbulent premixed flames over a wide range of Damköhler numbers in the framework of Probability Density Function (PDF) method still remain challenging due to the deficiency in current micro-mixing models. In this work, a hybrid micro-mixing model, valid in both the flamelet regime and broken reaction zone regime, is proposed. A priori testing of this model is first performed by examining the conditional scalar dissipation rate and conditional scalar diffusion in a 3-D direct numerical simulation dataset of a temporally evolving turbulent slot jet flame of lean premixed H2-air in the thin reaction zone regime. Then, this new model is applied to PDF simulations of the Piloted Premixed Jet Burner (PPJB) flames, which are a set of highly shear turbulent premixed flames and feature strong turbulence-chemistry interaction at high Reynolds and Karlovitz numbers. Supported by NSFC 51476087 and NSFC 91441202.

Analysis of the Hybrid Power System for High-Altitude Unmanned Aircraft

Directory of Open Access Journals (Sweden)

Kangwen Sun

2015-01-01

Full Text Available The application of single solar array on high-altitude unmanned aircraft will waste energy because of its low conversion efficiency. Furthermore, since its energy utilization is limited, the surface temperature of solar array will rise to 70°C due to the waste solar energy, thus reducing the electrical performance of the solar array. In order to reuse the energy converted into heat by solar array, a hybrid power system is presented in this paper. In the hybrid power system, a new electricity-generating method is adopted to spread the photovoltaic cell on the wing surface and arrange photothermal power in the wing box section. Because the temperature on the back of photovoltaic cell is high, it can be used as the high-temperature heat source. The lower wing surface can be a low-temperature cold source. A high-altitude unmanned aircraft was used to analyze the performances of pure solar-powered aircraft and hybrid powered aircraft. The analysis result showed that the hybrid system could reduce the area of wing by 19% and that high-altitude unmanned aircraft with a 35 m or less wingspan could raise the utilization rate of solar energy per unit area after adopting the hybrid power system.

Hybrid rendering of the chest and virtual bronchoscopy [corrected].

Science.gov (United States)

Seemann, M D; Seemann, O; Luboldt, W; Gebicke, K; Prime, G; Claussen, C D

2000-10-30

Thin-section spiral computed tomography was used to acquire the volume data sets of the thorax. The tracheobronchial system and pathological changes of the chest were visualized using a color-coded surface rendering method. The structures of interest were then superimposed on a volume rendering of the other thoracic structures, thus producing a hybrid rendering. The hybrid rendering technique exploit the advantages of both rendering methods and enable virtual bronchoscopic examinations using different representation models. Virtual bronchoscopic examinations with a transparent color-coded shaded-surface model enables the simultaneous visualization of both the airways and the adjacent structures behind of the tracheobronchial wall and therefore, offers a practical alternative to fiberoptic bronchoscopy. Hybrid rendering and virtual endoscopy obviate the need for time consuming detailed analysis and presentation of axial source images.

Mars Hybrid Propulsion System Trajectory Analysis. Part II; Cargo Missions

Science.gov (United States)

Chai, Patrick R.; Merrill, Raymond G.; Qu, Min

2015-01-01

NASA's Human Spaceflight Architecture Team is developing a reusable hybrid transportation architecture in which both chemical and electric propulsion systems are used to send crew and cargo to Mars destinations such as Phobos, Deimos, the surface of Mars, and other orbits around Mars. By combining chemical and electrical propulsion into a single spaceship and applying each where it is more effective, the hybrid architecture enables a series of Mars trajectories that are more fuel-efficient than an all chemical architecture without significant increases in flight times. This paper shows the feasibility of the hybrid transportation architecture to pre-deploy cargo to Mars and Phobos in support of the Evolvable Mars Campaign crew missions. The analysis shows that the hybrid propulsion stage is able to deliver all of the current manifested payload to Phobos and Mars through the first three crew missions. The conjunction class trajectory also allows the hybrid propulsion stage to return to Earth in a timely fashion so it can be reused for additional cargo deployment. The 1,100 days total trip time allows the hybrid propulsion stage to deliver cargo to Mars every other Earth-Mars transit opportunity. For the first two Mars surface mission in the Evolvable Mars Campaign, the short trip time allows the hybrid propulsion stage to be reused for three round-trip journeys to Mars, which matches the hybrid propulsion stage's designed lifetime for three round-trip crew missions to the Martian sphere of influence.

Dephasing of LO-phonon-plasmon hybrid modes in n-type GaAs

Science.gov (United States)

Vallée, F.; Ganikhanov, F.; Bogani, F.

1997-11-01

The relaxation dynamics of coherent phononlike LO-phonon-plasmon hybrid modes is investigated in n-doped GaAs using an infrared time-resolved coherent anti-Stokes Raman scattering technique. Measurements performed for different crystal temperatures in the range 10-300 K as a function of the electron density injected by doping show a large reduction of the hybrid mode dephasing time compared to the bare LO-phonon one for densities larger than 1016 cm-3. The results are interpreted in terms of coherent decay of the LO-phonon-plasmon mixed mode in the weak-coupling regime and yield information on the plasmon and electron relaxation. The estimated average electron momentum relaxation times are smaller than those deduced from Hall mobility measurements, as expected from our theoretical model.

Chitosan-nanosilica hybrid materials: Preparation and properties

International Nuclear Information System (INIS)

Podust, T.V.; Kulik, T.V.; Palyanytsya, B.B.; Gun’ko, V.M.; Tóth, A.; Mikhalovska, L.; Menyhárd, A.; László, K.

2014-01-01

Highlights: • Hybrid chitosan-nanosilica materials were synthesized using an adsorption modification method. • The chitosan adsorption capacity is higher on the silica/titania and silica/alumina than on the fumed silica. • Nanosilicas undergo structural and textural alterations due to modification by chitosan. • The more severe chitosan thermodestruction occurs on the silica/titania and silica/alumina surfaces than on the plain silica surface. - Abstract: The research focuses on the synthesis of novel organic–inorganic hybrid materials based on polysaccharide chitosan and nanosilicas (SiO 2 , TiO 2 /SiO 2 and Al 2 O 3 /SiO 2 ). The chitosan modified nanooxides were obtained by the equilibrium adsorption method. The chitosan adsorption capacities of silica/titania and silica/alumina are higher than of the plain silica due to the additional active sites present on the surfaces of the mixed oxides. The hybrid materials were characterized by low-temperature nitrogen adsorption/desorption, photon correlation spectroscopy (PCS), scanning electron microscopy (SEM), thermogravimetry (TG/DTG) and temperature-programmed desorption with mass spectrometry control (TPD MS) methods. The chitosan treatment only modestly influences the surface area S BET of the nanooxides but the rearrangement of the secondary and tertiary structures (aggregates and agglomerates) results in an enhancement of the mesoporosity and affects the size of the aggregates. The more severe thermodestruction of the polysaccharide desorbing from the modified mixed silicas indicates a stronger interaction between the chitosan and the mixed oxides compared to the silanol groups of the plain silica surface

Chitosan-nanosilica hybrid materials: Preparation and properties

Energy Technology Data Exchange (ETDEWEB)

Podust, T.V., E-mail: tania_list@yahoo.com [Chuiko Institute of Surface Chemistry, 17 General Naumov Street, Kyiv 03164 (Ukraine); Kulik, T.V., E-mail: tanyakulyk@i.ua [Chuiko Institute of Surface Chemistry, 17 General Naumov Street, Kyiv 03164 (Ukraine); Palyanytsya, B.B.; Gun’ko, V.M. [Chuiko Institute of Surface Chemistry, 17 General Naumov Street, Kyiv 03164 (Ukraine); Tóth, A. [Department of Physical Chemistry and Material Science, Budapest University of Technology and Economics, H-1521 Budapest (Hungary); Mikhalovska, L. [School of Pharmacy and Biomolecular Sciences, University of Brighton, Lewes Road, Brighton BN2 4GJ (United Kingdom); Menyhárd, A. [Department of Physical Chemistry and Material Science, Budapest University of Technology and Economics, H-1521 Budapest (Hungary); Institute of Materials Science and Environmental Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences (Hungary); László, K. [Department of Physical Chemistry and Material Science, Budapest University of Technology and Economics, H-1521 Budapest (Hungary)

2014-11-30

Highlights: • Hybrid chitosan-nanosilica materials were synthesized using an adsorption modification method. • The chitosan adsorption capacity is higher on the silica/titania and silica/alumina than on the fumed silica. • Nanosilicas undergo structural and textural alterations due to modification by chitosan. • The more severe chitosan thermodestruction occurs on the silica/titania and silica/alumina surfaces than on the plain silica surface. - Abstract: The research focuses on the synthesis of novel organic–inorganic hybrid materials based on polysaccharide chitosan and nanosilicas (SiO{sub 2}, TiO{sub 2}/SiO{sub 2} and Al{sub 2}O{sub 3}/SiO{sub 2}). The chitosan modified nanooxides were obtained by the equilibrium adsorption method. The chitosan adsorption capacities of silica/titania and silica/alumina are higher than of the plain silica due to the additional active sites present on the surfaces of the mixed oxides. The hybrid materials were characterized by low-temperature nitrogen adsorption/desorption, photon correlation spectroscopy (PCS), scanning electron microscopy (SEM), thermogravimetry (TG/DTG) and temperature-programmed desorption with mass spectrometry control (TPD MS) methods. The chitosan treatment only modestly influences the surface area S{sub BET} of the nanooxides but the rearrangement of the secondary and tertiary structures (aggregates and agglomerates) results in an enhancement of the mesoporosity and affects the size of the aggregates. The more severe thermodestruction of the polysaccharide desorbing from the modified mixed silicas indicates a stronger interaction between the chitosan and the mixed oxides compared to the silanol groups of the plain silica surface.

Nanostructured polymer- and metal surfaces

DEFF Research Database (Denmark)

Christiansen, Alexander Bruun

, on wafer scale. The BSi structures were replicated into the UV curable organicinorganic hybrid polymer Ormocomp, in order to further assess the optical properties of the structures. BSi structures with lateral dimensions of around 1 μm would selectively scatter specific bands of wavelengths, resulting...... in a structural colour filter for specularly transmitted light. By reducing the height and lateral size, the structures enter a regime where scattering of visible light becomes insignificant. In this regime, the BSi structures were shown to be antireflective. An empirical relation between the characteristic...... moulding in polypropylene. A Ni shim was electroplated from a BSi master, and inserted in an injection moulding tool. The reflectance of the injection moulded parts was reduced from 4.5 % to 2.5% in the visible spectrum. The reflectance was calculated from the gradient in the refractive index from AFM data...

Effect of Cut Quality on Hybrid Laser Arc Welding of Thick Section Steels

Science.gov (United States)

Farrokhi, F.; Nielsen, S. E.; Schmidt, R. H.; Pedersen, S. S.; Kristiansen, M.

From an industrial point of view, in a laser cutting-welding production chain, it is of great importance to know the influence of the attainable laser cut quality on the subsequent hybrid laser arc welding process. Many studies have been carried out in the literature to obtain lower surface roughness values on the laser cut edge. However, in practice, the cost and reliability of the cutting process is crucial and it does not always comply with obtaining the highest surface quality. In this study, a number of experiments on 25 mm steel plates were carried out to evaluate the influence of cut surface quality on the final quality of the subsequent hybrid laser welded joints. The different cut surfaces were obtained by different industrial cutting methods including laser cutting, abrasive water cutting, plasma cutting, and milling. It was found that the mentioned cutting methods could be used as preparation processes for the subsequent hybrid laser arc welding. However, cut quality could determine the choice of process parameters of the following hybrid laser arc welding.

Hybrid methods for witnessing entanglement in a microscopic-macroscopic system

International Nuclear Information System (INIS)

Spagnolo, Nicolo; Vitelli, Chiara; Paternostro, Mauro; De Martini, Francesco; Sciarrino, Fabio

2011-01-01

We propose a hybrid approach to the experimental assessment of the genuine quantum features of a general system consisting of microscopic and macroscopic parts. We infer entanglement by combining dichotomic measurements on a bidimensional system and phase-space inference through the Wigner distribution associated with the macroscopic component of the state. As a benchmark, we investigate the feasibility of our proposal in a bipartite-entangled state composed of a single-photon and a multiphoton field. Our analysis shows that, under ideal conditions, maximal violation of a Clauser-Horne-Shimony-Holt-based inequality is achievable regardless of the number of photons in the macroscopic part of the state. The difficulty in observing entanglement when losses and detection inefficiency are included can be overcome by using a hybrid entanglement witness that allows efficient correction for losses in the few-photon regime.

Hybrid methods for witnessing entanglement in a microscopic-macroscopic system

Energy Technology Data Exchange (ETDEWEB)

Spagnolo, Nicolo [Dipartimento di Fisica, Sapienza Universita di Roma, Piazzale Aldo Moro 5, I-00185 Roma (Italy); Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia, Piazzale Aldo Moro 5, I-00185 Roma (Italy); Vitelli, Chiara [Dipartimento di Fisica, Sapienza Universita di Roma, Piazzale Aldo Moro 5, I-00185 Roma (Italy); Paternostro, Mauro [School of Mathematics and Physics, Queen' s University, BT 7 1NN Belfast (United Kingdom); De Martini, Francesco [Dipartimento di Fisica, Sapienza Universita di Roma, Piazzale Aldo Moro 5, I-00185 Roma (Italy); Accademia Nazionale dei Lincei, via della Lungara 10, I-00165 Roma (Italy); Sciarrino, Fabio [Dipartimento di Fisica, Sapienza Universita di Roma, Piazzale Aldo Moro 5, I-00185 Roma (Italy); Istituto Nazionale di Ottica, Consiglio Nazionale delle Ricerche (INO-CNR), largo E. Fermi 6, I-50125 Firenze (Italy)

2011-09-15

We propose a hybrid approach to the experimental assessment of the genuine quantum features of a general system consisting of microscopic and macroscopic parts. We infer entanglement by combining dichotomic measurements on a bidimensional system and phase-space inference through the Wigner distribution associated with the macroscopic component of the state. As a benchmark, we investigate the feasibility of our proposal in a bipartite-entangled state composed of a single-photon and a multiphoton field. Our analysis shows that, under ideal conditions, maximal violation of a Clauser-Horne-Shimony-Holt-based inequality is achievable regardless of the number of photons in the macroscopic part of the state. The difficulty in observing entanglement when losses and detection inefficiency are included can be overcome by using a hybrid entanglement witness that allows efficient correction for losses in the few-photon regime.

DYNAMIC HYBRIDS UNDER SOLVENCY II: RISK ANALYSIS AND MODIFICATION POSSIBILITIES

Directory of Open Access Journals (Sweden)

Christian Maier

2017-06-01

Full Text Available In this study, we investigate the new and standardized European system of supervisory called Solvency II. In essence, asymmetric distribution of information between policyholder and insurer triggered this new regulation which aims at better protecting policyholders. Its three-pillar model is about to challenge both, insurers as well as policyholders. The first pillar includes quantitative aspects, the second pillar contains qualitative aspects and the third pillar comprises market transparency and reporting obligations. Underwriting risks, the default risk of a bank and market risks can be identified for the dynamic hybrid. Solvency II covers all these risks in the first pillar and insurers shall deposit sufficient risk-bearing capital. In our analysis, we first identify the dynamic hybrid specific risks under the Solvency II regime und then develop product modifications to reduce this risk.

Investigation of bubble flow regimes in nucleate boiling of highly-wetting liquids

International Nuclear Information System (INIS)

Tong, W.; Bar-Cohen, A.; Simon, T.W.

1991-01-01

This paper describes an investigation of the bubble flow regimes in nucleate boiling of FC-72, a highly-wetting liquid. Theoretically analysis of vapor bubble generation and departure from the heated surface reveals that the heat fluxes required for the merging of consecutive bubbles, for highly-wetting liquids, lie in the upper range of the nucleate boiling heat flux. A visual and photographic study of nucleate boiling from sputtered platinum surfaces has supported the theoretical results and shown that the isolated bubble behavior extends to at least 50-80% of the critical heat flux, considerably higher than observed by others with water. Lateral coalescence of adjacent bubbles has been found to be a more likely cause of the termination of the isolated bubble regime. These findings suggest that thermal transport models which are based on isolated bubble behavior may be applicable to nearly the entire range of nucleate boiling of electronic cooling fluids

Stationary magnetic shear reversal during Lower Hybrid experiments in Tore Supra

International Nuclear Information System (INIS)

Litaudon, X.; Arslanbekov, R.; Hoang, G.T.; Joffrin, E.; Kazarian-Vibert, F.; Moreau, D.; Peysson, Y.; Bibet, P.

1996-01-01

Stable and stationary states with hollow current density profiles have been achieved with Lower Hybrid Current Drive (LHCD) during Lower Hybrid (LH) wave accessibility experiments. By analysing the bounded propagation domain in phase space which naturally limits the central penetration and absorption of the waves, off-axis LH power deposition has been realized in a reproducible manner. The resulting current density profile modifications have led to a global confinement enhancement attributed to the formation of an internal 'transport barrier' in the central reversed shear region where the electron thermal diffusivity is reduced to its neoclassical collisional level. The multiple-pass LH wave propagation in the weak Landau damping and reversed magnetic shear regime is also investigated in the framework of a statistical theory and the experimental validation of this theory is discussed. (author)

Synthesis and Effect of Hierarchically Structured Ag-ZnO Hybrid on the Surface Antibacterial Activity of a Propylene-Based Elastomer Blends

Directory of Open Access Journals (Sweden)

Pavel Bazant

2018-03-01

Full Text Available In this study, a hybrid Ag-ZnO nanostructured micro-filler was synthesized by the drop technique for used in plastic and medical industry. Furthermore, new antibacterial polymer nanocomposites comprising particles of Ag-ZnO up to 5 wt % and a blend of a thermoplastic polyolefin elastomer (TPO with polypropylene were prepared using twin screw micro-compounder. The morphology and crystalline-phase structure of the hybrid Ag-ZnO nanostructured microparticles obtained was characterized by scanning electron microscopy and powder X-ray diffractometry. The specific surface area of this filler was investigated by means of nitrogen sorption via the Brunauer-Emmet-Teller method. A scanning electron microscope was used to conduct a morphological study of the polymer nanocomposites. Mechanical and electrical testing showed no adverse effects on the function of the polymer nanocomposites either due to the filler utilized or the given processing conditions, in comparison with the neat polymer matrix. The surface antibacterial activity of the compounded polymer nanocomposites was assessed against Escherichia coli ATCC 8739 and Staphylococcus aureus ATCC 6538P, according to ISO 22196:2007 (E. All the materials at virtually every filler-loading level were seen to be efficient against both species of bacteria.

Static converters power supply: transient regimes; Alimentation par convertisseurs statiques: regimes transitoires

Energy Technology Data Exchange (ETDEWEB)

Pasqualini, G. [Ecole Superieure d`Electricite (France)

1997-08-01

Direct current motors, asynchronous and variable speed synchronous motors are generally supplied with static converters. Speed variation is obtained by voltage variation in DC motors and by frequency variation in AC motors. In these conditions, these motors are running continuously in transient regimes: the DC motors current is not direct and the AC motors current is not sinusoidal. This situation leads to pulsing couples in the shaft line and to an increase of Joule effect losses. The aim of this paper is to present the methods of study of the electric motors functioning using the shape of the power voltages given by converters and mathematical models of these machines. The synchronous machines are rapidly described while the asynchronous machines are studied using Ku`s transformation instead of Park`s transformation for simplification. For each type of machine, calculation methods allow to determine their current, additional losses and couple characteristics. The transient regimes considered are those remaining when the motor is running at a constant speed and defined regime (supply voltages are periodical functions of time). These transient regimes are identically reproducing with a frequency which is a multiple of the converters supply frequency. Transient regimes due to functioning changes of the motor, such as resisting couple or power supply frequency variations, are not considered in this study. (J.S.) 9 refs.

Heating tokamaks via the ion-cyclotron and ion-ion hybrid resonances

International Nuclear Information System (INIS)

Perkins, F.W.

1977-04-01

For the ion-ion hybrid resonance it is shown that: (1) the energy absorption occurs via a sequence of mode conversions; (2) a poloidal field component normal to the ion-ion hybrid mode conversion surface strongly influences the mode conversion process so that roughly equal electron and ion heating occurs in the present proton-deuterium experiments, while solely electron heating is predicted to prevail in deuterium-tritium reactors; (3) the ion-ion hybrid resonance suppresses toroidal eigenmodes; and (4) wave absorption in minority fundamental ion-cyclotron heating experiments will be dominated by ion-ion hybrid mode conversion absorption for minority concentrations exceeding roughly 1 percent. For the ion-cyclotron resonance, it is shown that: (1) ion-cyclotron mode conversion leads to surface electron heating; and (2) ion-cyclotron mode conversion absorption dominates fundamental ion-cyclotron absorption thereby preventing efficient ion heating

Pure white-light emitting ultrasmall organic-inorganic hybrid perovskite nanoclusters.

Science.gov (United States)

Teunis, Meghan B; Lawrence, Katie N; Dutta, Poulami; Siegel, Amanda P; Sardar, Rajesh

2016-10-14

Organic-inorganic hybrid perovskites, direct band-gap semiconductors, have shown tremendous promise for optoelectronic device fabrication. We report the first colloidal synthetic approach to prepare ultrasmall (∼1.5 nm diameter), white-light emitting, organic-inorganic hybrid perovskite nanoclusters. The nearly pure white-light emitting ultrasmall nanoclusters were obtained by selectively manipulating the surface chemistry (passivating ligands and surface trap-states) and controlled substitution of halide ions. The nanoclusters displayed a combination of band-edge and broadband photoluminescence properties, covering a major part of the visible region of the solar spectrum with unprecedentedly large quantum yields of ∼12% and photoluminescence lifetime of ∼20 ns. The intrinsic white-light emission of perovskite nanoclusters makes them ideal and low cost hybrid nanomaterials for solid-state lighting applications.

Hybrid inorganic/organic photonic crystal biochips for cancer biomarkers detection

Science.gov (United States)

Sinibaldi, Alberto; Danz, Norbert; Munzert, Peter; Michelotti, Francesco

2018-06-01

We report on hybrid inorganic/organic one-dimensional photonic crystal biochips sustaining Bloch surface waves. The biochips were used, together with an optical platform operating in a label-free and fluorescence configuration simultaneously, to detect the cancer biomarker Angiopoietin 2 in a protein base buffer. The hybrid photonic crystals embed in their geometry a thin functionalization poly-acrylic acid layer deposited by plasma polymerization, which is used to immobilize a monoclonal antibody for highly specific biological recognition. The fluorescence operation mode is described in detail, putting into evidence the role of field enhancement and localization at the photonic crystal surface in the shaping and intensification of the angular fluorescence pattern. In the fluorescence operation mode, the hybrid biochips can attain the limit of detection 6 ng/ml.

Synthesis of biocompatible hydrophobic silica-gelatin nano-hybrid by sol-gel process.

Science.gov (United States)

Smitha, S; Shajesh, P; Mukundan, P; Nair, T D R; Warrier, K G K

2007-03-15

Silica-biopolymer hybrid has been synthesised using colloidal silica as the precursor for silica and gelatin as the biopolymer counterpart. The surface modification of the hybrid material has been done with methyltrimethoxysilane leading to the formation of biocompatible hydrophobic silica-gelatin hybrid. Here we are reporting hydrophobic silica-gelatin hybrid and coating precursor for the first time. The hybrid gel has been evaluated for chemical modification, thermal degradation, hydrophobicity, particle size, transparency under the UV-visible region and morphology. FTIR spectroscopy has been used to verify the presence of CH(3) groups which introduce hydrophobicity to the SiO2-MTMS-gelatin hybrids. The hydrophobic property has also been tailored by varying the concentration of methyltrimethoxysilane. Contact angle by Wilhelmy plate method of transparent hydrophobic silica-gelatin coatings has been found to be as high as approximately 95 degrees . Oxidation of the organic group which induces the hydrophobic character occurs at 530 degrees C which indicates that the surface hydrophobicity is retained up to that temperature. Optical transmittance of SiO2-MTMS-gelatin hybrid coatings on glass substrates has been found to be close to 100% which will enable the hybrid for possible optical applications and also for preparation of transparent biocompatible hydrophobic coatings on biological substrates such as leather.

Solution of the radiative enclosure with a hybrid inverse method

Energy Technology Data Exchange (ETDEWEB)

Silva, Rogerio Brittes da; Franca, Francis Henrique Ramos [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Dept. de Engenharia Mecanica], E-mail: frfranca@mecanica.ufrgs.br

2010-07-01

This work applies the inverse analysis to solve a three-dimensional radiative enclosure - which the surfaces are diffuse-grays - filled with transparent medium. The aim is determine the powers and locations of the heaters to attain both uniform heat flux and temperature on the design surface. A hybrid solution that couples two methods, the generalized extremal optimization (GEO) and the truncated singular value decomposition (TSVD) is proposed. The determination of the heat sources distribution is treated as an optimization problem, by GEO algorithm , whereas the solution of the system of equation, that embodies the Fredholm equation of first kind and therefore is expected to be ill conditioned, is build up through TSVD regularization method. The results show that the hybrid method can lead to a heat flux on the design surface that satisfies the imposed conditions with maximum error of less than 1,10%. The results illustrated the relevance of a hybrid method as a prediction tool. (author)

Retention and distribution of Cu, Pb, Cr, and Zn in a full-scale hybrid constructed wetland receiving municipal sewage

NARCIS (Netherlands)

Xiao, H.W.; Zhang, S.L.; Zhai, J.; He, Q.; Mels, A.R.; Ning, K.J.; Liu, J.

2013-01-01

This study was conducted to investigate the retention and distribution of Cu, Pb, Cr, and Zn in a hybrid constructed wetland (CW) that consists of both vertical baffled flow wetlands (VBFWs) and horizontal subsurface flow wetlands (HSSFs) with unique flow regimes and oxygen distribution. The heavy

Finite element modelling to assess the effect of surface mounted piezoelectric patch size on vibration response of a hybrid beam

Science.gov (United States)

Rahman, N.; Alam, M. N.

2018-02-01

Vibration response analysis of a hybrid beam with surface mounted patch piezoelectric layer is presented in this work. A one dimensional finite element (1D-FE) model based on efficient layerwise (zigzag) theory is used for the analysis. The beam element has eight mechanical and a variable number of electrical degrees of freedom. The beams are also modelled in 2D-FE (ABAQUS) using a plane stress piezoelectric quadrilateral element for piezo layers and a plane stress quadrilateral element for the elastic layers of hybrid beams. Results are presented to assess the effect of size of piezoelectric patch layer on the free and forced vibration responses of thin and moderately thick beams under clamped-free and clamped-clamped configurations. The beams are subjected to unit step loading and harmonic loading to obtain the forced vibration responses. The vibration control using in phase actuation potential on piezoelectric patches is also studied. The 1D-FE results are compared with the 2D-FE results.

Ag Nanorods-Oxide Hybrid Array Substrates: Synthesis, Characterization, and Applications in Surface-Enhanced Raman Scattering

Directory of Open Access Journals (Sweden)

Lingwei Ma

2017-08-01

Full Text Available Over the last few decades, benefitting from the sufficient sensitivity, high specificity, nondestructive, and rapid detection capability of the surface-enhanced Raman scattering (SERS technique, numerous nanostructures have been elaborately designed and successfully synthesized as high-performance SERS substrates, which have been extensively exploited for the identification of chemical and biological analytes. Among these, Ag nanorods coated with thin metal oxide layers (AgNRs-oxide hybrid array substrates featuring many outstanding advantages have been proposed as fascinating SERS substrates, and are of particular research interest. The present review provides a systematic overview towards the representative achievements of AgNRs-oxide hybrid array substrates for SERS applications from diverse perspectives, so as to promote the realization of real-world SERS sensors. First, various fabrication approaches of AgNRs-oxide nanostructures are introduced, which are followed by a discussion on the novel merits of AgNRs-oxide arrays, such as superior SERS sensitivity and reproducibility, high thermal stability, long-term activity in air, corrosion resistivity, and intense chemisorption of target molecules. Next, we present recent advances of AgNRs-oxide substrates in terms of practical applications. Intriguingly, the recyclability, qualitative and quantitative analyses, as well as vapor-phase molecule sensing have been achieved on these nanocomposites. We further discuss the major challenges and prospects of AgNRs-oxide substrates for future SERS developments, aiming to expand the versatility of SERS technique.

Atmospheric plasma surface modifications of electrospun PCL/chitosan/PCL hybrid scaffolds by nozzle type plasma jets for usage of cell cultivation

Energy Technology Data Exchange (ETDEWEB)

Surucu, Seda [Department of Metallurgical and Materials Engineering, Atilim University, Incek, Golbasi, 06836, Ankara (Turkey); Masur, Kai [Leibniz Institute for Plasma Science and Technology (Germany); Turkoglu Sasmazel, Hilal, E-mail: hilal.sasmazel@atilim.edu.tr [Department of Metallurgical and Materials Engineering, Atilim University, Incek, Golbasi, 06836, Ankara (Turkey); Von Woedtke, Thomas; Weltmann, Klaus Dieter [Leibniz Institute for Plasma Science and Technology (Germany)

2016-11-01

Highlights: • Electrospun PCL/chitosan/PCL scaffolds introduced to the literature by us were modified with atmospheric pressure plasma jets. • Plasma was fed into the system with different gas flow rates, time and distances. • Topographical and functional changes were examined by various characterization methods. • Optimum plasma treatment parameters for enhanced topography and functionality were determined. • Electrospun hybrid plasma surface modified samples showed the increased biocompatibility performance of L929 fibroblast cells. - Abstract: This paper reports Ar gas, Ar + O{sub 2}, Ar + O{sub 2} + N{sub 2} gas mixtures and dry air plasma modifications by atmospheric pressure argon driven kINPen and air driven Diener (PlasmaBeam) plasma jets to alter surface properties of three dimensional (3D), electrospun PCL/Chitosan/PCL layer by layer hybrid scaffolds to improve human fibroblast (MRC5) cell attachment and growth. The characterizations of the samples were done by contact angle (CA) measurements, scanning electron microscopy (SEM), X-Ray Photoelectron spectroscopy (XPS) analysis. The results showed that the plasma modification carried out under dry air and Ar + O{sub 2} + N{sub 2} gas mixtures were altered effectively the nanotopography and the functionality of the material surfaces. It was found that the samples treated with Ar + O{sub 2} + N{sub 2} gas mixtures for 1 min and dry air for 9 min have better hydrophilicity 78.9° ± 1.0 and 75.6° ± 0.1, respectively compared to the untreated samples (126.5°). Biocompatibility performance of the scaffolds was determined with alamarBlue (aB) assay and MTT assay methods, Giemsa staining, fluorescence microscope, confocal laser scanning microscope (CLSM) and scanning electron microscope (SEM) analyses. The results showed that plasma treated samples increased the hydrophilicity and oxygen functionality and topography of the surfaces significantly, thus affecting the cell viability and proliferation on

Atmospheric plasma surface modifications of electrospun PCL/chitosan/PCL hybrid scaffolds by nozzle type plasma jets for usage of cell cultivation

International Nuclear Information System (INIS)

Surucu, Seda; Masur, Kai; Turkoglu Sasmazel, Hilal; Von Woedtke, Thomas; Weltmann, Klaus Dieter

2016-01-01

Highlights: • Electrospun PCL/chitosan/PCL scaffolds introduced to the literature by us were modified with atmospheric pressure plasma jets. • Plasma was fed into the system with different gas flow rates, time and distances. • Topographical and functional changes were examined by various characterization methods. • Optimum plasma treatment parameters for enhanced topography and functionality were determined. • Electrospun hybrid plasma surface modified samples showed the increased biocompatibility performance of L929 fibroblast cells. - Abstract: This paper reports Ar gas, Ar + O_2, Ar + O_2 + N_2 gas mixtures and dry air plasma modifications by atmospheric pressure argon driven kINPen and air driven Diener (PlasmaBeam) plasma jets to alter surface properties of three dimensional (3D), electrospun PCL/Chitosan/PCL layer by layer hybrid scaffolds to improve human fibroblast (MRC5) cell attachment and growth. The characterizations of the samples were done by contact angle (CA) measurements, scanning electron microscopy (SEM), X-Ray Photoelectron spectroscopy (XPS) analysis. The results showed that the plasma modification carried out under dry air and Ar + O_2 + N_2 gas mixtures were altered effectively the nanotopography and the functionality of the material surfaces. It was found that the samples treated with Ar + O_2 + N_2 gas mixtures for 1 min and dry air for 9 min have better hydrophilicity 78.9° ± 1.0 and 75.6° ± 0.1, respectively compared to the untreated samples (126.5°). Biocompatibility performance of the scaffolds was determined with alamarBlue (aB) assay and MTT assay methods, Giemsa staining, fluorescence microscope, confocal laser scanning microscope (CLSM) and scanning electron microscope (SEM) analyses. The results showed that plasma treated samples increased the hydrophilicity and oxygen functionality and topography of the surfaces significantly, thus affecting the cell viability and proliferation on/within scaffolds.

Targeted delivery of 10-hydroxycamptothecin to human breast cancers by cyclic RGD-modified lipid-polymer hybrid nanoparticles.

Science.gov (United States)

Yang, Zhe; Luo, Xingen; Zhang, Xiaofang; Liu, Jie; Jiang, Qing

2013-04-01

Lipid-polymer hybrid nanoparticles (NPs) combining the positive attributes of both liposomes and polymeric NPs are increasingly being considered as promising candidates to carry therapeutic agents safely and efficiently into targeted sites. Herein, a modified emulsification technique was developed and optimized for the targeting lipid-polymer hybrid NPs fabrication; the surface properties and stability of the hybrid NPs were systematically investigated, which confirmed that the hybrid NPs consisted of a poly (lactide-co-glycolide) core with ∼90% surface coverage of the lipid monolayer and a ∼4.4 nm hydrated polyethylene glycol (PEG) shell. Optimization results showed that the lipid:polymer mass ratio and the lipid-PEG:lipid molar ratio could affect the size, lipid association efficiency and stability of hybrid NPs. Furthermore, a model chemotherapy drug, 10-hydroxycamptothecin, was encapsulated into hybrid NPs with a higher drug loading compared to PLGA NPs. Surface modification of the lipid layer and the PEG conjugated targeting ligand did not affect their drug release kinetics. Finally, the cytotoxicity and cellular uptake studies indicated that the lipid coverage and the c(RGDyk) conjugation of the hybrid NPs gained a significantly enhanced ability of cell killing and endocytosis. Our results suggested that lipid-polymer hybrid NPs prepared by the modified emulsion technique have great potential to be utilized as an engineered drug delivery system with precise control ability of surface targeting modification.

Targeted delivery of 10-hydroxycamptothecin to human breast cancers by cyclic RGD-modified lipid–polymer hybrid nanoparticles

International Nuclear Information System (INIS)

Yang, Zhe; Luo, Xingen; Zhang, Xiaofang; Liu, Jie; Jiang, Qing

2013-01-01

Lipid–polymer hybrid nanoparticles (NPs) combining the positive attributes of both liposomes and polymeric NPs are increasingly being considered as promising candidates to carry therapeutic agents safely and efficiently into targeted sites. Herein, a modified emulsification technique was developed and optimized for the targeting lipid–polymer hybrid NPs fabrication; the surface properties and stability of the hybrid NPs were systematically investigated, which confirmed that the hybrid NPs consisted of a poly (lactide-co-glycolide) core with ∼90% surface coverage of the lipid monolayer and a ∼4.4 nm hydrated polyethylene glycol (PEG) shell. Optimization results showed that the lipid:polymer mass ratio and the lipid-PEG:lipid molar ratio could affect the size, lipid association efficiency and stability of hybrid NPs. Furthermore, a model chemotherapy drug, 10-hydroxycamptothecin, was encapsulated into hybrid NPs with a higher drug loading compared to PLGA NPs. Surface modification of the lipid layer and the PEG conjugated targeting ligand did not affect their drug release kinetics. Finally, the cytotoxicity and cellular uptake studies indicated that the lipid coverage and the c(RGDyk) conjugation of the hybrid NPs gained a significantly enhanced ability of cell killing and endocytosis. Our results suggested that lipid–polymer hybrid NPs prepared by the modified emulsion technique have great potential to be utilized as an engineered drug delivery system with precise control ability of surface targeting modification. (paper)

Surface density dependence of PCR amplicon hybridization on PNA/DNA probe layers

DEFF Research Database (Denmark)

Yao, Danfeng; Kim, Junyoung; Yu, Fang

2005-01-01

at an intermediate sodium concentration (approximately 100 mM). These effects were mainly ascribed to the electrostatic cross talk among the hybridized DNA molecules and the secondary structure of PCR amplicons. For the negatively charged DNA probes, the hybridization reaction was subjected additionally to the DNA....../DNA electrostatic barrier, particularly in lower ionic strength range (e.g., 10 approximately 150 mM Na(+)). The electrostatic cross talk was shown to be largely reduced if the PNA probe layer was sufficiently diluted by following a strategic templated immobilization method. As a consequence, a pseudo...

Fabrication and characterization of stable superhydrophobic fluorinated-polyacrylate/silica hybrid coating

International Nuclear Information System (INIS)

Li, Kunquan; Zeng, Xingrong; Li, Hongqiang; Lai, Xuejun

2014-01-01

Graphical abstract: - Highlights: • The superhydrophobic PFA/SiO 2 coating was successfully fabricated by spraying. • The synthesized PFA latex showed core–shell structure and good dispersion. • The PFA/SiO 2 coating showed good resistance to acid and base, weather and heat. • The superhydrophobic coating could be fabricated on various substrates. - Abstract: The core–shell fluorinated-polyacrylate (PFA) emulsion was synthesized through emulsion polymerization method and the superhydrophobic PFA/SiO 2 hybrid coating was successfully fabricated on the slide glass by spraying the mixture of PFA emulsion and hydrophobic SiO 2 particles using ethanol as cosolvent. The PFA emulsion was characterized by Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), water contact angle (WCA), transmission electron microscopy (TEM), and the effects of SiO 2 content on the wetting behavior and surface morphology of PFA/SiO 2 hybrid coating were investigated. To evaluate the stability of the hybrid coating, the acid and base resistance, weatherability and thermal stability were also studied. Results showed that the obtained PFA latex exhibited a core–shell structure with a particle size of 134.1 nm and a narrow polydispersity of 0.03. With the increase of dodecafluoroheptyl methacrylate (DFMA) content in the latex shell from 0 wt% to 31.8 wt%, the WCA of the PFA film enlarged from 85° to 104°, indicating that the introduction of fluorinated monomer was effective in reducing the surface energy. By adding different amount of SiO 2 particles, the surface morphology and wetting behavior of the PFA/SiO 2 hybrid coatings could be controlled. When the mass ratio of SiO 2 to PFA emulsion was 0.2, the surface roughness (Rq) increased to 173.6 nm and the wetting behavior of the surface became superhydrophobic with a WCA of 153°, resulted from the corporation of low surface energy and the binary nano/microstructure on the surface. The as-prepared PFA

Sustainable urban regime adjustments

DEFF Research Database (Denmark)

Quitzau, Maj-Britt; Jensen, Jens Stissing; Elle, Morten

2013-01-01

The endogenous agency that urban governments increasingly portray by making conscious and planned efforts to adjust the regimes they operate within is currently not well captured in transition studies. There is a need to acknowledge the ambiguity of regime enactment at the urban scale. This direc...

Regimes of seasonal air-sea interaction and implications for performance of forced simulations

Energy Technology Data Exchange (ETDEWEB)

Wu, Renguang [Center for Ocean-Land-Atmosphere Studies, Calverton, MD (United States); Kirtman, Ben P. [Center for Ocean-Land-Atmosphere Studies, Calverton, MD (United States); George Mason University, School of Computational Sciences, Fairfax, VA (United States)

2007-09-15

Sea surface temperature (SST) anomalies can induce anomalous convection through surface evaporation and low-level moisture convergence. This SST forcing of the atmosphere is indicated in a positive local rainfall-SST correlation. Anomalous convection can feedback on SST through cloud-radiation and wind-evaporation effects and wind-induced oceanic mixing and upwelling. These atmospheric feedbacks are reflected in a negative local rainfall-SST tendency correlation. As such, the simultaneous rainfall-SST and rainfall-SST tendency correlations can indicate the nature of local air-sea interactions. Based on the magnitude of simultaneous rainfall-SST and rainfall-SST tendency correlations, the present study identifies three distinct regimes of local air-sea interactions. The relative importance of SST forcing and atmospheric forcing differs in these regimes. In the equatorial central-eastern Pacific and, to a smaller degree, in the western equatorial Indian Ocean, SST forcing dominates throughout the year and the surface heat flux acts mainly as a damping term. In the tropical Indo-western Pacific Ocean regions, SST forcing and atmospheric forcing dominate alternatively in different seasons. Atmospheric forcing dominates in the local warm/rainy season. SST forcing dominates with a positive wind-evaporation feedback during the transition to the cold/dry season. SST forcing also dominates during the transition to the warm/rainy season but with a negative cloud-radiation feedback. The performance of atmospheric general circulation model simulations forced by observed SST is closely linked to the regime of air-sea interaction. The forced simulations have good performance when SST forcing dominates. The performance is low or poor when atmospheric forcing dominates. (orig.)

Hybrid Fluid/Kinetic Modeling Of Magnetized High Energy Density Plasmas

Science.gov (United States)

Hansen, David; Held, Eric; King, Jacob; Stoltz, Peter; Masti, Robert; Srinivasan, Bhuvana

2017-10-01

MHD modeling with an equation of state (EOS) of the Rayleigh-Taylor (RT) instabily in Z indicates that it is seeded by the electro-thermal instability. Large thermodynamic drives associated with gradients at the interface between the liner and the coronal regions distort distribution functions and likely lead to non-local transport effects in a plasma which varies from weakly to strongly coupled. In this work, we discuss using effective potential theory along with a Chapman-Ensksog-like (CEL) formalism to develop hybrid fluid/kinetic modeling capabilities for these plasmas. Effective potential theory addresses the role of Coulomb collisions on transport across coupling regimes and the CEL approach bridges the gap between full-blow kinetic simulations and the EOS tables, which only depend locally on density and temperature. Quantitative results on the Spitzer problem across coupling coupling regimes will be presented as a first step. DOE Grant No. DE-SC0016525.

Alterations in the extracellular matrix organization associated with the reexpression of tumorigenicity in human cell hybrids.

Science.gov (United States)

Der, C J; Stanbridge, E J

1980-10-15

The expression of fibronectin on the cell surface was evaluated on a series of intraspecific human cell hybrids formed between HeLa and normal fibroblast strains. Although these hybrids continued to express many of the in vitro transformation properties of their corresponding tumorigenic HeLa parent, they were now unable to form tumors when inoculated into athymic nude mice. From these suppressed hybrid populations, rare tumorigenic segregant subpopulations arose which had regained their tumorigenic capacity. A comparison of the expression of fibronectin on the cell surface was made between these tumorigenic segregant cell lines and their corresponding non-tumorigenic HeLa/fibroblast hybrid. Following specific immunofluorescent staining for fibronectin, a striking alteration in the cell surface organization was observed to correspond with the reexpression of tumorigenicity in these hybrids. Tumorigenic HeLa/fibroblast hybrids were also significantly altered in both their cellular and colonial morphology. Double immunofluorescent staining to simultaneously visualize both surface fibronectin and collagen revealed that these two extracellular matrix proteins displayed an extensive degree of codistribution and expressed a coordinate shift in organization which correlated with the appearance of tumorigenic segregant hybrid populations. These observations are in agreement with the apparently close structural association between fibronectin and collagen and suggest that the organization of these two components in the extracellular matrix may be an important determinant for in vivo growth potential.

Groundwater quality assessment for the Chestnut Ridge Hydrogeologic Regime at the Y-12 Plant

International Nuclear Information System (INIS)

1992-08-01

This report contains an evaluation of groundwater quality data obtained during the 1991 calendar year at several hazardous and non-hazardous waste-management facilities associated with the US Department of Energy Y- 12 Plant. These sites are located south of the Y- 12 Plant in the Chestnut Ridge Hydrogeologic Regime (CRHR), which is one of three regimes defined for the purposes of groundwater and surface-water quality monitoring. Section 2.0 of this report contains background information regarding groundwater monitoring at the waste-management sites located in the CRHR. An overview of the hydrogeologic system in the CRHR is provided in Section 3.0. A discussion of the interpretive assumptions used in evaluating the 1991 assessment data and detailed descriptions of groundwater quality in the regime are presented

International Food Regime

Directory of Open Access Journals (Sweden)

A. V. Malov

2018-01-01

Full Text Available The review article reveals the content of the concept of Food Regime, which is little-known in the Russian academic reference. The author monitored and codified the semantic dynamic of the terminological unit from its original interpretations to modern formulations based on the retrospective analysis. The rehabilitation of the academic merits of D. Puchala and R. Hopkins — authors who used the concept Food Regime for a few years before its universally recognized origin and official scientific debut, was accomplished with help of historical and comparative methods. The author implemented the method of ascension from the abstract to the concrete to demonstrating the classification of Food Regimes compiled on the basis of geopolitical interests in the sphere of international production, consumption, and distribution of foodstuffs. The characteristic features of historically formed Food Regime were described in the chronological order, as well as modern tendencies possessing reformist potential were identified. In particular, it has been established that the idea of Food Sovereignty (which is an alternative to the modern Corporate Food Regime is the subject for acute academic disputes. The discussion between P. McMichael P. and H. Bernstein devoted to the “peasant question” — mobilization frame of the Food Sovereignty strategy was analyzed using the secondary data processing method. Due to the critical analysis, the author comes to the conclusion that it is necessary to follow the principles of the Food Sovereignty strategy to prevent the catastrophic prospects associated with ecosystem degradation, accelerated erosion of soils, the complete disappearance of biodiversity and corporate autoc racy successfully. The author is convinced that the idea of Food Sovereignty can ward off energetic liberalization of nature, intensive privatization of life and rapid monetization of unconditioned human reflexes.

Microcantilver-based DNA hybridization sensors for Salmonella identification

Directory of Open Access Journals (Sweden)

Carlo Ricciardi

2012-02-01

Full Text Available The detection of pathogenic microorganisms in foods remains a challenging since the safety of foodstuffs has to be ensured by the food producing companies. Conventional methods for the detection and identification of bacteria mainly rely on specific microbiological and biochemical identification. Biomolecular methods, are commonly used as a support for traditional techniques, thanks to their high sensitivity, specificity and not excessive costs. However, new methods like biosensors for example, can be an exciting alternative to the more traditional tecniques for the detection of pathogens in food. In this study we report Salmonella enterica serotype Enteritidis DNA detection through a novel class of label-free biosensors: microcantilevers (MCs. In general, MCs can operate as a microbalance and is used to detect the mass of the entities anchored to the cantilever surface using the decrease in the resonant frequency. We use DNA hybridization as model reaction system and for this reason, specific single stranded probe DNA of the pathogen and three different DNA targets (single-stranded complementary DNA, PCR product and serial dilutions of DNA extracted from S. Enteritidis strains were applied. Two protocols were reported in order to allow the probe immobilization on cantilever surface: i MC surface was functionalized with 3-aminopropyltriethoxysilane and glutaraldehyde and an amino-modified DNA probe was used; ii gold-coated sensors and thiolated DNA probes were used in order to generate a covalent bonding (Th-Au. For the first one, measures after hybridization with the PCR product showed related frequency shift 10 times higher than hybridization with complementary probe and detectable signals were obtained at the concentrations of 103 and 106 cfu/mL after hybridization with bacterial DNA. There are currently optimizations of the second protocol, where preliminary results have shown to be more uniform and therefore more precise within each of the

Antecedents of Teachers Fostering Effort within Two Different Management Regimes: An Assessment-Based Accountability Regime and Regime without External Pressure on Results

Science.gov (United States)

Christophersen, Knut-Andreas; Elstad, Eyvind; Turmo, Are

2012-01-01

This article focuses on the comparison of organizational antecedents of teachers' fostering of students' effort in two quite different accountability regimes: one management regime with an external-accountability system and one with no external accountability devices. The methodology involves cross-sectional surveys from two different management…

Visões de um objeto incômodo: o regime militar brasileiro An undesirable subject: the Brazilian military regime

Directory of Open Access Journals (Sweden)

Angelo Del Vecchio

2007-05-01

Full Text Available O presente artigo visa a qualificação do regime político vigente no Brasil entre 1964-1985. Para tanto, desenvolvo o resgate do conceito de ditadura, especialmente a partir da obra de Carl Schimitt, e busco aferir a sua adequação à análise do período militar. Palavras-chave: Estado. Regime político. Ditadura. Regime militar. The present article tries to qualify the political regime in Brazil from 1964 to 1985, using the concept of dictatorship mainly developed by Carl Schimitt in his writings and tries to adequate this concept to the Brazilian military regime. Keywords: State. Political regime. Dictatorship. Military regime.

THE INFLUENCED FLOW REGIMES

Directory of Open Access Journals (Sweden)

Gavril PANDI

2011-03-01

Full Text Available The influenced flow regimes. The presence and activities ofhumanity influences the uniform environmental system, and in this context, therivers water resources. In concordance with this, the natural runoff regime suffersbigger and deeper changes. The nature of these changes depending on the type anddegree of water uses. The multitude of the use cause different types of influence,whit different quantitative aspects. In the same time, the influences havequalitative connotations, too, regarding to the modifications of the yearly watervolume runoff. So the natural runoff regime is modified. After analyzing thedistribution laws of the monthly runoff, there have been differenced four types ofinfluenced runoff regimes. In the excess type the influenced runoff is bigger thanthe natural, continuously in the whole year. The deficient type is characterized byinverse rapports like the first type, in the whole year. In the sinusoidal type, theinfluenced runoff is smaller than the natural in the period when the water isretained in the lake reservoirs, and in the depletion period the situation inverts. Atthe irregular type the ratio between influenced and natural runoff is changeable ina random meaner monthly. The recognition of the influenced regime and the gradeof influence are necessary in the evaluation and analysis of the usable hydrologicalriver resources, in the flood defence activities, in the complex scheme of thehydrographic basins, in the environment design and so on.

On the Dynamical Regimes of Pattern-Accelerated Electroconvection.

Science.gov (United States)

Davidson, Scott M; Wessling, Matthias; Mani, Ali

2016-03-03

Recent research has established that electroconvection can enhance ion transport at polarized surfaces such as membranes and electrodes where it would otherwise be limited by diffusion. The onset of such overlimiting transport can be influenced by the surface topology of the ion selective membranes as well as inhomogeneities in their electrochemical properties. However, there is little knowledge regarding the mechanisms through which these surface variations promote transport. We use high-resolution direct numerical simulations to develop a comprehensive analysis of electroconvective flows generated by geometric patterns of impermeable stripes and investigate their potential to regularize electrokinetic instabilities. Counterintuitively, we find that reducing the permeable area of an ion exchange membrane, with appropriate patterning, increases the overall ion transport rate by up to 80%. In addition, we present analysis of nonpatterned membranes, and find a novel regime of electroconvection where a multivalued current is possible due to the coexistence of multiple convective states.

Some aspects of correction additions optimisation of water chemistry regime of Kozloduy NPP power units 3 and 4

International Nuclear Information System (INIS)

Topalova, I.

2005-01-01

Optimization of the water-chemistry regime is a major corrective measure for minimization of the corrosion processes of the nuclear power unit equipment. Research done in NPP Kozloduy III - IV power units concerning the migration of the corrosion products in the water of secondary circuit as well as the connection between corrosion processes and fluctuation in parameters of the applied water-chemistry regime are reported. Analysis of the dependences obtained lead to conclusions for optimization of the water chemistry regime of secondary circuit and minimization of the corrosion processes and improvement of corrosion condition of metal surfaces. The research is done for the circuit of each of the 8 turbines of the two power units for a period of 10 days. Data received is quantitatively representative /40-50 points/ for performing of analysis and reaching certain conclusions for the water chemistry regime and development of corrosion processes. Dependence of iron and copper concentration in the work medium on the pH, ammonia and hydrazine concentration as well as the dependence of pH on ammonia concentration in case of different quantity and composition of corrosion products on the different power units' equipment metal surfaces are shown. (author)

Reconstruction of surface morphology from coherent scattering of ''white'' synchrotron radiation in hard X-ray regime

Energy Technology Data Exchange (ETDEWEB)

Sant, Tushar

2009-07-01

Energy Dispersive Reflectometry (EDR) beamline at BESSY II provides ''white'' X-rays in the useful energy range of 5surfaces. Technologically smooth wafers of semiconducting materials of Si and GaAs are used as ''trivial'' samples to determine the so called apparatus function. In addition I measured coherent reflectivity maps from thin film of highly scattering material of Pt with high atom number, Z=78 and patterned semiconducting surface like a GaAs surface grating which provides a certain periodicity in the measured scattering intensity. Finally I measured the surface speckles from a spatially confined Si wafer under the constraint that the size of the sample is smaller than the footprint of the incoming beam at the sample position. To reconstruct surface morphology from coherent reflectivity data is a typical inverse problem. Conventional phase retrieval algorithms like Gerchberg-Saxton (GS) algorithm, error reduction (ER) algorithm, hybrid input-output (HIO) algorithm are used in earlier work by other authors. I modified the conventional GS algorithm and ER algorithm which takes into account the additional Fresnel propagator term and also the illumination function at the sample position. I tested the modified algorithm successfully for a model surface in the form of a surface grating. I used the modified algorithm to reconstruct surface morphology from various static speckle measurements I performed at EDR beamline. The surface profiles reconstructed for different samples from the data at different energies (below the critical energy for the material at a particular incident angle) show almost the same roughness behavior for surface height with mean roughness of {proportional_to}1 nm. With the static speckle data I measured I could retrieve a one-dimensional picture of the sample surface with spatial

Preparation of Transparent Bulk TiO2/PMMA Hybrids with Improved Refractive Indices via an in Situ Polymerization Process Using TiO2 Nanoparticles Bearing PMMA Chains Grown by Surface-Initiated Atom Transfer Radical Polymerization.

Science.gov (United States)

Maeda, Satoshi; Fujita, Masato; Idota, Naokazu; Matsukawa, Kimihiro; Sugahara, Yoshiyuki

2016-12-21

Transparent TiO 2 /PMMA hybrids with a thickness of 5 mm and improved refractive indices were prepared by in situ polymerization of methyl methacrylate (MMA) in the presence of TiO 2 nanoparticles bearing poly(methyl methacrylate) (PMMA) chains grown using surface-initiated atom transfer radical polymerization (SI-ATRP), and the effect of the chain length of modified PMMA on the dispersibility of modified TiO 2 nanoparticles in the bulk hybrids was investigated. The surfaces of TiO 2 nanoparticles were modified with both m-(chloromethyl)phenylmethanoyloxymethylphosphonic acid bearing a terminal ATRP initiator and isodecyl phosphate with a high affinity for common organic solvents, leading to sufficient dispersibility of the surface-modified particles in toluene. Subsequently, SI-ATRP of MMA was achieved from the modified surfaces of the TiO 2 nanoparticles without aggregation of the nanoparticles in toluene. The molecular weights of the PMMA chains cleaved from the modified TiO 2 nanoparticles increased with increases in the prolonging of the polymerization period, and these exhibited a narrow distribution, indicating chain growth controlled by SI-ATRP. The nanoparticles bearing PMMA chains were well-dispersed in MMA regardless of the polymerization period. Bulk PMMA hybrids containing modified TiO 2 nanoparticles with a thickness of 5 mm were prepared by in situ polymerization of the MMA dispersion. The transparency of the hybrids depended significantly on the chain length of the modified PMMA on the nanoparticles, because the modified PMMA of low molecular weight induced aggregation of the TiO 2 nanoparticles during the in situ polymerization process. The refractive indices of the bulk hybrids could be controlled by adjusting the TiO 2 content and could be increased up to 1.566 for 6.3 vol % TiO 2 content (1.492 for pristine PMMA).

The difficult challenge of a two-phase CFD modelling for all flow regimes

International Nuclear Information System (INIS)

Bestion, D.

2014-01-01

Highlights: • The theoretical difficulties for modelling all flow regimes at CFD scale are identified. • The choice of the number of fields and of the time and space averaging or filtering are discussed and clarified. • Closure issues related to an all flow regime CFD model are listed and the main difficulties are identified. - Abstract: System thermalhydraulic codes model all two-phase flow regimes but they are limited to a macroscopic description. Two-phase CFD tools predict two-phase flow with a much finer space resolution but the current modelling capabilities are limited to dispersed bubbly or droplet flow and separate-phase flow. Much less experience exists on more complex flow regimes which combine the existence of dispersed fields with the presence of large interfaces such as a free surface or a film surface. A list of possible reactor issues which might benefit from an “all flow regime CFD model” is given. The first difficulty is to identify the various types of local flow configuration. It is shown that a 4-field model has much better capabilities than a two-fluid approach to identify most complex regimes. Then the choice between time averaging, space averaging, or even ensemble averaging is discussed. It is shown that only the RANS-2-fluid and a space-filtered 4-field model may be reasonably envisaged. The latter has the capabilities to identify all types of interfaces and should be privileged if a good accuracy is expected or if time fluctuations in intermittent flow have to be predicted while the former may be used when a high accuracy is not necessary and if time fluctuations in intermittent flow are not of interest. Finally the closure issue is presented including wall transfers, interfacial transfers, mass transfers between dispersed and continuous fields, and turbulent transfers. An important effort is required to model all interactions between sub-filter phenomena and the transfers from the sub-filter domain to the simulated domain. The

Hybrid approaches to nanometer-scale patterning: Exploiting tailored intermolecular interactions

International Nuclear Information System (INIS)

Mullen, Thomas J.; Srinivasan, Charan; Shuster, Mitchell J.; Horn, Mark W.; Andrews, Anne M.; Weiss, Paul S.

2008-01-01

In this perspective, we explore hybrid approaches to nanometer-scale patterning, where the precision of molecular self-assembly is combined with the sophistication and fidelity of lithography. Two areas - improving existing lithographic techniques through self-assembly and fabricating chemically patterned surfaces - will be discussed in terms of their advantages, limitations, applications, and future outlook. The creation of such chemical patterns enables new capabilities, including the assembly of biospecific surfaces to be recognized by, and to capture analytes from, complex mixtures. Finally, we speculate on the potential impact and upcoming challenges of these hybrid strategies.

Flux scaling: Ultimate regime

Indian Academy of Sciences (India)

First page Back Continue Last page Overview Graphics. Flux scaling: Ultimate regime. With the Nusselt number and the mixing length scales, we get the Nusselt number and Reynolds number (w'd/ν) scalings: and or. and. scaling expected to occur at extremely high Ra Rayleigh-Benard convection. Get the ultimate regime ...

Primordial anisotropies in gauged hybrid inflation

Science.gov (United States)

Akbar Abolhasani, Ali; Emami, Razieh; Firouzjahi, Hassan

2014-05-01

We study primordial anisotropies generated in the model of gauged hybrid inflation in which the complex waterfall field is charged under a U(1)gauge field. Primordial anisotropies are generated either actively during inflation or from inhomogeneities modulating the surface of end of inflation during waterfall transition. We present a consistent δN mechanism to calculate the anisotropic power spectrum and bispectrum. We show that the primordial anisotropies generated at the surface of end of inflation do not depend on the number of e-folds and therefore do not produce dangerously large anisotropies associated with the IR modes. Furthermore, one can find the parameter space that the anisotropies generated from the surface of end of inflation cancel the anisotropies generated during inflation, therefore relaxing the constrains on model parameters imposed from IR anisotropies. We also show that the gauge field fluctuations induce a red-tilted power spectrum so the averaged power spectrum from the gauge field can change the total power spectrum from blue to red. Therefore, hybrid inflation, once gauged under a U(1) field, can be consistent with the cosmological observations.

Primordial anisotropies in gauged hybrid inflation

International Nuclear Information System (INIS)

Abolhasani, Ali Akbar; Emami, Razieh; Firouzjahi, Hassan

2014-01-01

We study primordial anisotropies generated in the model of gauged hybrid inflation in which the complex waterfall field is charged under a U(1)gauge field. Primordial anisotropies are generated either actively during inflation or from inhomogeneities modulating the surface of end of inflation during waterfall transition. We present a consistent δN mechanism to calculate the anisotropic power spectrum and bispectrum. We show that the primordial anisotropies generated at the surface of end of inflation do not depend on the number of e-folds and therefore do not produce dangerously large anisotropies associated with the IR modes. Furthermore, one can find the parameter space that the anisotropies generated from the surface of end of inflation cancel the anisotropies generated during inflation, therefore relaxing the constrains on model parameters imposed from IR anisotropies. We also show that the gauge field fluctuations induce a red-tilted power spectrum so the averaged power spectrum from the gauge field can change the total power spectrum from blue to red. Therefore, hybrid inflation, once gauged under a U(1) field, can be consistent with the cosmological observations

A hybrid of cells and pancreatic islets toward a new bioartificial pancreas

Directory of Open Access Journals (Sweden)

Yuji Teramura

2016-03-01

Full Text Available Cell surface engineering using single-stranded DNA–poly(ethylene glycol-conjugated phospholipid (ssDNA–PEG-lipid is useful for inducing cell–cell attachment two and three dimensionally. In this review, we summarize our recent techniques for cell surface engineering and their applications to islet transplantation. Because any DNA sequence can be immobilized onto the cell surface by hydrophobic interactions between ssDNA–PEG-lipid and the cellular membrane without impairing cell function, a cell–cell hybrid can be formed through the DNA hybridization. With this technique, it would be possible to create three-dimensional hybrid structures of pancreatic islets coated with various accessory cells, such as patients’ own cells, mesenchymal and adipose-derived stem cells, endothelial progenitor cells, neural crest stem cells or regulatory T cells, which might significantly improve the outcome of islet transplantation in diabetic patients.

Effects of Hybrid Coat on shear bond strength of five cements: an in vitro study.

Science.gov (United States)

Guo, Yue; Zhou, Hou-De; Feng, Yun-Zhi

2017-12-01

To evaluate the sealing performance of Hybrid Coat and its influence on the shear bond strength of five dentin surface cements. Six premolars were pretreated to expose the dentin surface prior to the application of Hybrid Coat. The microscopic characteristics of the dentinal surfaces were examined with scanning electron microscopy (SEM). Then, 40 premolars were sectioned longitudinally, and 80 semi-sections were divided into a control group (untreated) and a study group (treated by Hybrid Coat). Alloy restoration was bonded to the teeth specimen using five different cements. Shear bond strength was measured by the universal testing machine. The fracture patterns and the adhesive interface were observed using astereomicroscope. SEM revealed that the lumens of dentinal tubules were completely occluded by Hybrid Coat. The Hybrid Coat significantly improved the shear bond strength of resin-modified glass ionomer cement (RMGIC) and resin cement (RC) but weakened the performance of zinc phosphate cement (ZPC), zinc polycarboxylate cement (ZPCC) and glass ionomer cement (GIC). Hybrid Coat is an effective dentinal tubule sealant, and therefore its combined use with resin or resin-modified glass ionomer cements can be applied for the prostheses attachment purpose.

Headcut erosive regimes influenced by groundwater on disturbed agricultural soils.

Science.gov (United States)

Rockwell, D L

2011-02-01

A series of simulated rainfall experiments, testing several soils and slope gradients in a 10 m x 0.8m laboratory flume, displayed close correlations between initial development of a water table at a 10 cm depth and highly erosive headcut formation. On some soils and gradients, highly erosive headcuts formed consistently and predictably within minutes or seconds of initial water table rise. However, headcuts alone were not good indicators of increased erosion. In most experiments some headcuts formed early, often when surface hydraulic parameter values reached established rill initiation thresholds, but resulted in little or no erosion increase. Later, at initial water table rise, other headcuts formed coincident with major erosion increase, often with surface hydraulic values then less than rill initiation thresholds. On the four soils tested, highly erosive headcuts never formed without groundwater development, except on steep 9 ° slopes. Common visual indicators such as headcut morphology and headcut advance rates were not effective means of determining either erosion or the existence of groundwater. Only local monitoring of subsurface moisture conditions with micro-standpipes and TDR aided in determining headcut processes and erosive regimes. Groundwater-influenced headcut formation was likely caused by increased soil pore-water pressures and decreased soil shear strengths in surface rainflow, not by sapping or seepage from the soil matrix. Highly erosive headcuts can thus form under common agricultural conditions where reductions in permeability, such as plow pans, exist near the surface--without the need for saturated soils. Headcut erosive regimes were also significantly influenced by soil type and slope gradient, with the greatest effects of groundwater on moderate slopes and fairly permeable soils. Copyright © 2010. Published by Elsevier Ltd.

Application of a hybrid method for downscaling of the global climate model fields for evaluation of future surface mass balance of mountain glaciers

Science.gov (United States)

Morozova, Polina; Rybak, Oleg; Kaminskaia, Mariia

2017-04-01

Mountain glaciers in the Caucasus have been degrading during the last century. During this time period they lost approximately one-third in area and half of their volume. Prediction of their evolution in changing climate is crucial for the local economy because hydrological regime in the territory north to the Main Caucasus Chain is mainly driven by glacier run-off. For future projections of glaciers' surface mass balance (SMB) we apply a hybrid method of downscaling of GCM-generated meteorological fields from the global scale to the characteristic spatial resolution normally used for modeling of a single mountain glacier SMB. A method consists of two stages. On the first, dynamical stage, we use the results of calculations of regional climate model (RCM) HadRM3P for the Black Sea-Caspian region with a spatial resolution of approximately 25 km. Initial and boundary conditions for HadRM3P are provided by an AO GCM INMCM developed in the Institute of Numerical Mathematics (Moscow, Russia). Calculations were carried out for two time slices: the present (reference) climate (1971-2000 years) and climate in the late 21st century (2071-2100 years) according to scenario of greenhouse gas emissions RCP 8.5. On the second stage of downscaling, further regionalization is achieved by projecting of RCM-generated data to the high-resolution (25 m) digital elevation models in a domain enclosing target glaciers (Marukh in the Western Caucasus and Djankuat in the Central Caucasus, both being typical valley glaciers). Elevation gradient of surface air temperature and precipitation were derived from the model data. Further, results were corrected using data of observations. The incoming shortwave radiation is calculated separately, taking into account slopes, aspects and shade effect. In the end of the current century expected air temperature growth in the Central and Western Caucasus is about 5-6 °C (summer), and 2-3 °C (winter). Reduction in annual precipitation is not

Abrupt climate-independent fire regime changes

Science.gov (United States)

Pausas, Juli G.; Keeley, Jon E.

2014-01-01

Wildfires have played a determining role in distribution, composition and structure of many ecosystems worldwide and climatic changes are widely considered to be a major driver of future fire regime changes. However, forecasting future climatic change induced impacts on fire regimes will require a clearer understanding of other drivers of abrupt fire regime changes. Here, we focus on evidence from different environmental and temporal settings of fire regimes changes that are not directly attributed to climatic changes. We review key cases of these abrupt fire regime changes at different spatial and temporal scales, including those directly driven (i) by fauna, (ii) by invasive plant species, and (iii) by socio-economic and policy changes. All these drivers might generate non-linear effects of landscape changes in fuel structure; that is, they generate fuel changes that can cross thresholds of landscape continuity, and thus drastically change fire activity. Although climatic changes might contribute to some of these changes, there are also many instances that are not primarily linked to climatic shifts. Understanding the mechanism driving fire regime changes should contribute to our ability to better assess future fire regimes.

Optimisation of hybrid high-modulus/high-strength carbon fiber reinforced plastic composite drive

OpenAIRE

Montagnier, Olivier; Hochard, Christian

2011-01-01

International audience; This study deals with the optimisation of hybrid composite drive shafts operating at subcritical or supercritical speeds, using a genetic algorithm. A formulation for the flexural vibrations of a composite drive shaft mounted on viscoelastic supports including shear effects is developed. In particular, an analytic stability criterion is developed to ensure the integrity of the system in the supercritical regime. Then it is shown that the torsional strength can be compu...

Observation of Lorentzian lineshapes in the room temperature optical spectra of strongly coupled Jaggregate/metal hybrid nanostructures by linear two-dimensional optical spectroscopy

International Nuclear Information System (INIS)

Wang, Wei; Sommer, Ephraim; De Sio, Antonietta; Gross, Petra; Vogelgesang, Ralf; Lienau, Christoph; Vasa, Parinda

2014-01-01

We analyze the linear optical reflectivity spectra of a prototypical, strongly coupled metal/molecular hybrid nanostructure by means of a new experimental approach, linear two-dimensional optical spectroscopy. White-light, broadband spectral interferometry is used to measure amplitude and spectral phase of the sample reflectivity or transmission with high precision and to reconstruct the time structure of the electric field emitted by the sample upon impulsive excitation. A numerical analysis of this time-domain signal provides a two-dimensional representation of the coherent optical response of the sample as a function of excitation and detection frequency. The approach is used to study a nanostructure formed by depositing a thin J-aggregated dye layer on a gold grating. In this structure, strong coupling between excitons and surface plasmon polaritons results in the formation of hybrid polariton modes. In the strong coupling regime, Lorentzian lineshape profiles of different polariton modes are observed at room temperature. This is taken as an indication that the investigated strongly coupled polariton excitations are predominantly homogeneously broadened at room temperature. This new approach presents a versatile, simple and highly precise addition to nonlinear optical spectroscopic techniques for the analysis of line broadening phenomena. (paper)

An Integrated Hybrid Transportation Architecture for Human Mars Expeditions

Science.gov (United States)

Merrill, Raymond G.; Chai, Patrick R.; Qu, Min

2015-01-01

NASA's Human Spaceflight Architecture Team is developing a reusable hybrid transportation architecture that uses both chemical and electric propulsion systems on the same vehicle to send crew and cargo to Mars destinations such as Phobos, Deimos, the surface of Mars, and other orbits around Mars. By applying chemical and electrical propulsion where each is most effective, the hybrid architecture enables a series of Mars trajectories that are more fuel-efficient than an all chemical architecture without significant increases in flight times. This paper presents an integrated Hybrid in-space transportation architecture for piloted missions and delivery of cargo. A concept for a Mars campaign including orbital and Mars surface missions is described in detail including a system concept of operations and conceptual design. Specific constraints, margin, and pinch points are identified for the architecture and opportunities for critical path commercial and international collaboration are discussed.

Photovoltaic characterization of hybrid solar cells using surface modified TiO2 nanoparticles and poly(3-hexyl)thiophene

International Nuclear Information System (INIS)

Guenes, Serap; Marjanovic, Nenad; Nedeljkovic, Jovan M; Sariciftci, Niyazi Serdar

2008-01-01

We report on the photovoltaic performance of bulk heterojunction solar cells using novel nanoparticles of 6-palmitate ascorbic acid surface modified TiO 2 as an electron acceptor embedded into the donor poly(3-hexyl)thiophene (P3HT) matrix. Devices were fabricated by using P3HT with varying amounts of red TiO 2 nanoparticles (1:1, 1:2, 1:3 w-w ratio). The devices were characterized by measuring current-voltage characteristics under simulated AM 1.5 conditions. Incident photon to current efficiency (IPCE) was spectrally resolved. The nanoscale morphology of such organic/inorganic hybrid blends was also investigated using atomic force microscopy (AFM).

What controls the hybridization thermodynamics of spherical nucleic acids?

Science.gov (United States)

Randeria, Pratik S; Jones, Matthew R; Kohlstedt, Kevin L; Banga, Resham J; Olvera de la Cruz, Monica; Schatz, George C; Mirkin, Chad A

2015-03-18

The hybridization of free oligonucleotides to densely packed, oriented arrays of DNA modifying the surfaces of spherical nucleic acid (SNA)-gold nanoparticle conjugates occurs with negative cooperativity; i.e., each binding event destabilizes subsequent binding events. DNA hybridization is thus an ever-changing function of the number of strands already hybridized to the particle. Thermodynamic quantification of this behavior reveals a 3 orders of magnitude decrease in the binding constant for the capture of a free oligonucleotide by an SNA conjugate as the fraction of pre-hybridized strands increases from 0 to ∼30%. Increasing the number of pre-hybridized strands imparts an increasing enthalpic penalty to hybridization that makes binding more difficult, while simultaneously decreasing the entropic penalty to hybridization, which makes binding more favorable. Hybridization of free DNA to an SNA is thus governed by both an electrostatic barrier as the SNA accumulates charge with additional binding events and an effect consistent with allostery, where hybridization at certain sites on an SNA modify the binding affinity at a distal site through conformational changes to the remaining single strands. Leveraging these insights allows for the design of conjugates that hybridize free strands with significantly higher efficiencies, some of which approach 100%.

Studies on corrosion protection of laser hybrid welded AISI 316 by laser remelting

DEFF Research Database (Denmark)

Olsen, Flemming Ove; Ambat, Rajan; Rasmussen, A.J.

2005-01-01

laser surface melting on microstructure and corrosion behaviour of AISI 316L welds. Welding and laser treatment parameters were varied. General corrosion behaviour of the weld and laser treated surface was characterised using a gel visualization test. The local electrochemistry of the weld and laser......Unlike in autogenous laser welding, hybrid laser welding of stainless steel could introduce grain boundary carbides due to low cooling rates. Formation of grain boundary carbides leads to reduced corrosion properties. Studies have initially been carried out on hybrid laser welding and subsequent...... treated surface was investigated using a novel micro electrochemical technique with a tip resolution of ~1 mm. Results show that hybrid laser welding of 316L has increased corrosion susceptibility probably as a result of grain boundary carbide formation. However a suitable post laser treatment could...

Electron spectroscopy of nanodiamond surface states

Energy Technology Data Exchange (ETDEWEB)

Belobrov, P.I.; Bursill, L.A.; Maslakov, K.I.; Dementjev, A.P

2003-06-15

Electronic states of nanodiamond (ND) were investigated by PEELS, XPS and CKVV Auger spectra. Parallel electron energy loss spectra (PEELS) show that the electrons inside of ND particles are sp{sup 3} hybridized but there is a surface layer containing distinct hybridized states. The CKVV Auger spectra imply that the HOMO of the ND surface has a shift of 2.5 eV from natural diamond levels of {sigma}{sub p} up to the Fermi level. Hydrogen (H) treatment of natural diamond surface produces a chemical state indistinguishable from that of ND surfaces using CKVV. The ND electronic structure forms {sigma}{sub s}{sup 1}{sigma}{sub p}{sup 2}{pi}{sup 1} surface states without overlapping of {pi}-levels. Surface electronic states, including surface plasmons, as well as phonon-related electronic states of the ND surface are also interesting and may also be important for field emission mechanisms from the nanostructured diamond surface.

Metal hydride and pyrophoric fuel additives for dicyclopentadiene based hybrid propellants

Science.gov (United States)

Shark, Steven C.

The purpose of this study is to investigate the use of reactive energetic fuel additives that have the potential to increase the combustion performance of hybrid rocket propellants in terms of solid fuel regression rate and combustion efficiency. Additives that can augment the combustion flame zone in a hybrid rocket motor by means of increased energy feedback to the fuel grain surface are of great interest. Metal hydrides have large volumetric hydrogen densities, which gives these materials high performance potential as fuel additives in terms of specifc impulse. The excess hydrogen and corresponding base metal may also cause an increase in the hybrid rocket solid fuel regression rate. Pyrophoric additives also have potential to increase the solid fuel regression rate by reacting more readily near the burning fuel surface providing rapid energy feedback. An experimental performance evaluation of metal hydride fuel additives for hybrid rocket motor propulsion systems is examined in this study. Hypergolic ignition droplet tests and an accelerated aging study revealed the protection capabilities of Dicyclopentadiene (DCPD) as a fuel binder, and the ability for unaided ignition. Static hybrid rocket motor experiments were conducted using DCPD as the fuel. Sodium borohydride (NabH4) and aluminum hydride (AlH3) were examined as fuel additives. Ninety percent rocket grade hydrogen peroxide (RGHP) was used as the oxidizer. In this study, the sensitivity of solid fuel regression rate and characteristic velocity (C*) efficiency to total fuel grain port mass flux and particle loading is examined. These results were compared to HTPB combustion performance as a baseline. Chamber pressure histories revealed steady motor operation in most tests, with reduced ignition delays when using NabH4 as a fuel additive. The addition of NabH4 and AlH3 produced up to a 47% and 85% increase in regression rate over neat DCPD, respectively. For all test conditions examined C* efficiency ranges

The trade regime and the climate regime. Institutional evolution and adaptation

International Nuclear Information System (INIS)

Brewer, Thomas L.

2003-01-01

This article addresses concerns that the multilateral trade regime centered in the WTO and the emerging climate regime may conflict in ways that could be damaging to either or both. The article discusses the institutional and diplomatic context of these concerns, and it identifies the kinds of issues that are in question. The analysis suggests that there are opportunities for win-win outcomes in the interactions of the two regimes, for instance in the possibility of reducing fossil fuel subsidies. However, there are also problematic areas where they intersect. A core issue-and as yet an unresolved one-is whether and how emission credit trading and other activities envisioned by the Kyoto Protocol would be subject to WTO rules. The resolution of this issue will affect many other issues as well. Additional specific issues about the interactions of particular provisions in WTO agreements and the Kyoto Protocol are analyzed in a subsequent companion article in Climate Policy

Hybrid quantum-classical modeling of quantum dot devices

Science.gov (United States)

Kantner, Markus; Mittnenzweig, Markus; Koprucki, Thomas

2017-11-01

The design of electrically driven quantum dot devices for quantum optical applications asks for modeling approaches combining classical device physics with quantum mechanics. We connect the well-established fields of semiclassical semiconductor transport theory and the theory of open quantum systems to meet this requirement. By coupling the van Roosbroeck system with a quantum master equation in Lindblad form, we introduce a new hybrid quantum-classical modeling approach, which provides a comprehensive description of quantum dot devices on multiple scales: it enables the calculation of quantum optical figures of merit and the spatially resolved simulation of the current flow in realistic semiconductor device geometries in a unified way. We construct the interface between both theories in such a way, that the resulting hybrid system obeys the fundamental axioms of (non)equilibrium thermodynamics. We show that our approach guarantees the conservation of charge, consistency with the thermodynamic equilibrium and the second law of thermodynamics. The feasibility of the approach is demonstrated by numerical simulations of an electrically driven single-photon source based on a single quantum dot in the stationary and transient operation regime.

An extended fractal growth regime in the diffusion limited aggregation including edge diffusion

Directory of Open Access Journals (Sweden)

Aritra Ghosh

2016-01-01

Full Text Available We have investigated on-lattice diffusion limited aggregation (DLA involving edge diffusion and compared the results with the standard DLA model. For both cases, we observe the existence of a crossover from the fractal to the compact regime as a function of sticking coefficient. However, our modified DLA model including edge diffusion shows an extended fractal growth regime like an earlier theoretical result using realistic growth models and physical parameters [Zhang et al., Phys. Rev. Lett. 73 (1994 1829]. While the results of Zhang et al. showed the existence of the extended fractal growth regime only on triangular but not on square lattices, we find its existence on the square lattice. There is experimental evidence of this growth regime on a square lattice. The standard DLA model cannot characterize fractal morphology as the fractal dimension (Hausdorff dimension, DH is insensitive to morphology. It also predicts DH = DP (the perimeter dimension. For the usual fractal structures, observed in growth experiments on surfaces, the perimeter dimension can differ significantly (DH ≠ DP depending on the morphology. Our modified DLA model shows minor sensitivity to this difference.

Does the hybrid light source (LED/laser) influence temperature variation on the enamel surface during 35% hydrogen peroxide bleaching? A randomized clinical trial.

Science.gov (United States)

de Freitas, Patricia Moreira; Menezes, Andressa Nery; da Mota, Ana Carolina Costa; Simões, Alyne; Mendes, Fausto Medeiros; Lago, Andrea Dias Neves; Ferreira, Leila Soares; Ramos-Oliveira, Thayanne Monteiro

2016-01-01

The present study investigated how a hybrid light source (LED/laser) influences temperature variation on the enamel surfaces during 35% hydrogen peroxide (HP) bleaching. Effects on the whitening effectiveness and tooth sensitivity were analyzed. Twenty-two volunteers were randomly assigned to two different treatments in a split-mouth experimental model: group 1 (control), 35% HP; group 2 (experimental), 35% HP + LED/laser. Color evaluation was performed before treatment, and 7 and 14 days after completion of bleaching, using a color shade scale. Tooth sensitivity was assessed using a visual analog scale (VAS; before, immediately, and 24 hours after bleaching). During the bleaching treatment, thermocouple channels positioned on the tooth surfaces recorded the temperature. Data on color and temperature changes were subjected to statistical analysis (α = 5%). Tooth sensitivity data were evaluated descriptively. Groups 1 and 2 showed mean temperatures (± standard deviation) of 30.7 ± 1.2 °C and 34.1 ± 1.3 °C, respectively. It was found that there were statistically significant differences between the groups, with group 2 showing higher mean variation (P enamel surface. The color change results showed no differences in bleaching between the two treatment groups (P = .177). The variation of the average temperature during the treatments was not statistically associated with color variation (P = .079). Immediately after bleaching, it was found that 36.4% of the subjects in group 2 had mild to moderate sensitivity. In group 1, 45.5% showed moderate sensitivity. In both groups, the sensitivity ceased within 24 hours. Hybrid light source (LED/ laser) influences temperature variation on the enamel surface during 35% HP bleaching and is not related to greater tooth sensitivity.

Groundwater quality assessment for the Bear Creek Hydrogeologic Regime at the Y-12 Plant: 1991 groundwater quality data and calculated rate of contaminant migration

Energy Technology Data Exchange (ETDEWEB)

1992-02-01

The report contains groundwater and surface water quality data obtained during the 1991 calendar year at several hazardous and non- hazardous waste management facilities associated with the US Department of Energy (DOE) Y-12 Plant (Figure 1). These sites are southwest of the Y-12 Plant complex within the Bear Creek Hydrogeologic Regime (BCHR), which is one of three regimes defined for the purposes of groundwater and surface-water quality monitoring and remediation (Figure 2). The Environmental Management Department of the Y-12 Plant Health, Safety, Environment, and Accountability (HSEA) Division manages the monitoring activities in each regime as part of the Y-12 Plant Groundwater Protection Program (GWPP).

Groundwater quality assessment for the Bear Creek Hydrogeologic Regime at the Y-12 Plant: 1991 groundwater quality data and calculated rate of contaminant migration

International Nuclear Information System (INIS)

1992-02-01

The report contains groundwater and surface water quality data obtained during the 1991 calendar year at several hazardous and non- hazardous waste management facilities associated with the US Department of Energy (DOE) Y-12 Plant (Figure 1). These sites are southwest of the Y-12 Plant complex within the Bear Creek Hydrogeologic Regime (BCHR), which is one of three regimes defined for the purposes of groundwater and surface-water quality monitoring and remediation (Figure 2). The Environmental Management Department of the Y-12 Plant Health, Safety, Environment, and Accountability (HSEA) Division manages the monitoring activities in each regime as part of the Y-12 Plant Groundwater Protection Program (GWPP)

Viscoelastic and fractal characteristics of a supramolecular hydrogel hybridized with clay nanoparticles.

Science.gov (United States)

Song, Fei; Zhang, Li-Ming; Shi, Jun-Feng; Li, Nan-Nan

2010-12-01

The supramolecular hydrogels derived from low-molecular-mass gelators represent a unique class of soft matters and have important potential applications in biomedical fields, separation technology and cosmetic science. However, they suffer usually from weak mechanical and viscoelastic properties. In this work, we carry out the in situ hybridization of clay nanoparticles (Laponite RD) into the supramolecular hydrogel formed from a low-molecular-mass hydrogelator, 2,6-di[N-(carboxyethyl carbonyl)amino]pyridine (DAP), and investigate the viscoelastic and structural characteristics of resultant hybrid hydrogel. It was found that a small concentration of Laponite RD could lead to a significant increase in the storage modulus, loss modulus or complex viscosity. Compared with neat DAP hydrogel, the hybrid hydrogel has a greater hydrogel strength and a lower relaxation exponent. In particular, the enhancement of the clay nanoparticles to the viscoelastic properties of the DAP hydrogel is more effective in the case of higher DAP concentration. By relating its macroscopic elastic properties to a scaling fractal model, such a hybrid hydrogel was confirmed to be in the strong-link regime and to have a more complex network structure with a higher fractal dimension when compared with neat DAP hydrogel. Copyright © 2010 Elsevier B.V. All rights reserved.

Synergies between nonproliferation regimes: A pragmatic approach

International Nuclear Information System (INIS)

Findlay, Trevor; Meier, Oliver

2001-01-01

Full text: With the recent progress in establishing international nonproliferation regimes, the question of synergies between different verification and monitoring regimes is becoming more acute. Three multilateral and universal nonproliferation organisations covering safeguards on civil nuclear materials, nuclear testing, and chemical weapons are up and running. A regime on biological weapons is under negotiation. Several regional organisations concerned with monitoring nonproliferation commitments in the nuclear field are in place; others are being established. Past discussions on synergies between these regimes have suffered from being too far-reaching. These discussions often have not reflected adequately the political difficulties of cooperation between regimes with different membership, scope and institutional set-up. This paper takes a pragmatic look at exploiting synergies and identifies some potential and real overlaps in the work between different verification regimes. It argues for a bottom-up approach and identifies building blocks for collaboration between verification regimes. By realising such, more limited potential for cooperation, the ground could be prepared for exploiting other synergies between these regimes. (author)

De Facto Regimes in International Law

Directory of Open Access Journals (Sweden)

Jonte van Essen

2012-02-01

Full Text Available The ambiguous position of de facto regimes in international law has long been the subject of scholarly debate and a source of political conflict. An assessment of the current standing of these regimes in international law and the consequences of actions by international actors on this status has, however, been long overdue. The manner in which de facto regimes are regarded internationally has serious consequences for the individuals under the influence of this legal grey area. Therefore, the study into this problem and possible solutions is of great significance. The 2011 developments in Northern Africa underline the need of contemporary research into this area. This essay aims to clarify the position of de facto regimes in international law and the influence on their status by actions of international actors. The author first argues that de facto regimes have rights and obligations under international law, which provide them with (some form of international legal personality. He then pleads for a reconsideration of the contemporary legal treatment of these regimes. The author argues against the current system of government recognition and proposes a system that better addresses the needs of both de facto regimes and the international community. 

Mediated Electron Transfer at Vertically Aligned Single-Walled Carbon Nanotube Electrodes During Detection of DNA Hybridization

Science.gov (United States)

Wallen, Rachel; Gokarn, Nirmal; Bercea, Priscila; Grzincic, Elissa; Bandyopadhyay, Krisanu

2015-06-01

Vertically aligned single-walled carbon nanotube (VASWCNT) assemblies are generated on cysteamine and 2-mercaptoethanol (2-ME)-functionalized gold surfaces through amide bond formation between carboxylic groups generated at the end of acid-shortened single-walled carbon nanotubes (SWCNTs) and amine groups present on the gold surfaces. Atomic force microscopy (AFM) imaging confirms the vertical alignment mode of SWCNT attachment through significant changes in surface roughness compared to bare gold surfaces and the lack of any horizontally aligned SWCNTs present. These SWCNT assemblies are further modified with an amine-terminated single-stranded probe-DNA. Subsequent hybridization of the surface-bound probe-DNA in the presence of complementary strands in solution is followed using impedance measurements in the presence of Fe(CN)6 3-/4- as the redox probe in solution, which show changes in the interfacial electrochemical properties, specifically the charge-transfer resistance, due to hybridization. In addition, hybridization of the probe-DNA is also compared when it is attached directly to the gold surfaces without any intermediary SWCNTs. Contrary to our expectations, impedance measurements show a decrease in charge-transfer resistance with time due to hybridization with 300 nM complementary DNA in solution with the probe-DNA attached to SWCNTs. In contrast, an increase in charge-transfer resistance is observed with time during hybridization when the probe-DNA is attached directly to the gold surfaces. The decrease in charge-transfer resistance during hybridization in the presence of VASWCNTs indicates an enhancement in the electron transfer process of the redox probe at the VASWCNT-modified electrode. The results suggest that VASWCNTs are acting as mediators of electron transfer, which facilitate the charge transfer of the redox probe at the electrode-solution interface.

Quantum Key Distribution Based on a Weak-Coupling Cavity QED Regime

International Nuclear Information System (INIS)

Li Chun-Yan; Li Yan-Song

2011-01-01

We present a quantum key distribution scheme using a weak-coupling cavity QED regime based on quantum dense coding. Hybrid entanglement states of photons and electrons are used to distribute information. We just need to transmit photons without storing them in the scheme. The electron confined in a quantum dot, which is embedded in a microcavity, is held by one of the legitimate users throughout the whole communication process. Only the polarization of a single photon and spin of electron measurements are applied in this protocol, which are easier to perform than collective-Bell state measurements. Linear optical apparatus, such as a special polarizing beam splitter in a circular basis and single photon operations, make it more flexible to realize under current technology. Its efficiency will approach 100% in the ideal case. The security of the scheme is also discussed. (general)

Hierarchical porous carbon/MnO2 hybrids as supercapacitor electrodes.

Science.gov (United States)

Lee, Min Eui; Yun, Young Soo; Jin, Hyoung-Joon

2014-12-01

Hybrid electrodes of hierarchical porous carbon (HPC) and manganese oxide (MnO2) were synthesized using a fast surface redox reaction of potassium permanganate under facile immersion methods. The HPC/MnO2 hybrids had a number of micropores and macropores and the MnO2 nanoparticles acted as a pseudocapacitive material. The synergistic effects of electric double-layer capacitor (EDLC)-induced capacitance and pseudocapacitance brought about a better electrochemical performance of the HPC/MnO2 hybrid electrodes compared to that obtained with a single component. The hybrids showed a specific capacitance of 228 F g(-1) and good cycle stability over 1000 cycles.

Enhanced charge carrier transport properties in colloidal quantum dot solar cells via organic and inorganic hybrid surface passivation† †Electronic supplementary information (ESI) available. See DOI: 10.1039/c6ta06835a Click here for additional data file.

Science.gov (United States)

Hong, John; Hou, Bo; Lim, Jongchul; Pak, Sangyeon; Kim, Byung-Sung; Cho, Yuljae; Lee, Juwon; Lee, Young-Woo; Giraud, Paul; Lee, Sanghyo; Park, Jong Bae; Morris, Stephen M.; Snaith, Henry J.; Kim, Jong Min

2016-01-01

Colloidal quantum dots (CQDs) are extremely promising as photovoltaic materials. In particular, the tunability of their electronic band gap and cost effective synthetic procedures allow for the versatile fabrication of solar energy harvesting cells, resulting in optimal device performance. However, one of the main challenges in developing high performance quantum dot solar cells (QDSCs) is the improvement of the photo-generated charge transport and collection, which is mainly hindered by imperfect surface functionalization, such as the presence of surface electronic trap sites and the initial bulky surface ligands. Therefore, for these reasons, finding effective methods to efficiently decorate the surface of the as-prepared CQDs with new short molecular length chemical structures so as to enhance the performance of QDSCs is highly desirable. Here, we suggest employing hybrid halide ions along with the shortest heterocyclic molecule as a robust passivation structure to eliminate surface trap sites while decreasing the charge trapping dynamics and increasing the charge extraction efficiency in CQD active layers. This hybrid ligand treatment shows a better coordination with Pb atoms within the crystal, resulting in low trap sites and a near perfect removal of the pristine initial bulky ligands, thereby achieving better conductivity and film structure. Compared to halide ion-only treated cells, solar cells fabricated through this hybrid passivation method show an increase in the power conversion efficiency from 5.3% for the halide ion-treated cells to 6.8% for the hybrid-treated solar cells. PMID:29308200

Investigation of Supercurrent in the Quantum Hall Regime in Graphene Josephson Junctions

Science.gov (United States)

Draelos, Anne W.; Wei, Ming Tso; Seredinski, Andrew; Ke, Chung Ting; Mehta, Yash; Chamberlain, Russell; Watanabe, Kenji; Taniguchi, Takashi; Yamamoto, Michihisa; Tarucha, Seigo; Borzenets, Ivan V.; Amet, François; Finkelstein, Gleb

2018-06-01

In this study, we examine multiple encapsulated graphene Josephson junctions to determine which mechanisms may be responsible for the supercurrent observed in the quantum Hall (QH) regime. Rectangular junctions with various widths and lengths were studied to identify which parameters affect the occurrence of QH supercurrent. We also studied additional samples where the graphene region is extended beyond the contacts on one side, making that edge of the mesa significantly longer than the opposite edge. This is done in order to distinguish two potential mechanisms: (a) supercurrents independently flowing along both non-contacted edges of graphene mesa, and (b) opposite sides of the mesa being coupled by hybrid electron-hole modes flowing along the superconductor/graphene boundary. The supercurrent appears suppressed in extended junctions, suggesting the latter mechanism.

Colloidal Au-enhanced surface plasmon resonance imaging: application in a DNA hybridization process

International Nuclear Information System (INIS)

Manera, M G; Spadavecchia, J; Taurino, A; Rella, R

2010-01-01

The detection of the DNA hybridization mechanism using monodispersed gold nanoparticles as labels is an interesting alternative to increase the sensitivity of the SPR imaging technique. DNA-modified Au nanoparticles (DNA-Au NPs) containing single-stranded (ss) portions of DNA were prepared by monitoring their monolayer formation by UV–vis spectroscopy. The hybridization process between specific thio-oligonucleotides immobilized on the DNA–Au NPs and the corresponding complementary strands is reported and compared with the traditional hybridization process on properly self-assembled thin gold films deposited on glass substrates. A remarkable signal amplification is observed, following the incorporation of colloidal Au into a SPR biosensing experiment, resulting in an increased SPR response to DNA–DNA interactions. In particular Fusarium thiolated DNA (5'HS poly(T) 15 ATC CCT CAA AAA CTG CCG CT-3) and trichothecenes complementary DNA (5'-AGC GGC AGT TTT TGA GGG AT-3') sequences have been explored due to their possible application to agro-industry for the control of food quality

Graphene hybridization for energy storage applications.

Science.gov (United States)

Li, Xianglong; Zhi, Linjie

2018-05-08

Graphene has attracted considerable attention due to its unique two-dimensional structure, high electronic mobility, exceptional thermal conductivity, excellent optical transmittance, good mechanical strength, and ultrahigh surface area. To meet the ever increasing demand for portable electronic products, electric vehicles, smart grids, and renewable energy integrations, hybridizing graphene with various functions and components has been demonstrated to be a versatile and powerful strategy to significantly enhance the performance of various energy storage systems such as lithium-ion batteries, supercapacitors and beyond, because such hybridization can result in synergistic effects that combine the best merits of involved components and confer new functions and properties, thereby improving the charge/discharge efficiencies and capabilities, energy/power densities, and cycle life of these energy storage systems. This review will focus on diverse graphene hybridization principles and strategies for energy storage applications, and the proposed outline is as follows. First, graphene and its fundamental properties, followed by graphene hybrids and related hybridization motivation, are introduced. Second, the developed hybridization formulas of using graphene for lithium-ion batteries are systematically categorized from the viewpoint of material structure design, bulk electrode construction, and material/electrode collaborative engineering; the latest representative progress on anodes and cathodes of lithium-ion batteries will be reviewed following such classifications. Third, similar hybridization formulas for graphene-based supercapacitor electrodes will be summarized and discussed as well. Fourth, the recently emerging hybridization formulas for other graphene-based energy storage devices will be briefed in combination with typical examples. Finally, future prospects and directions on the exploration of graphene hybridization toward the design and construction of

In situ hybridization at the electron microscope level: hybrid detection by autoradiography and colloidal gold.

Science.gov (United States)

Hutchison, N J; Langer-Safer, P R; Ward, D C; Hamkalo, B A

1982-11-01

In situ hybridization has become a standard method for localizing DNA or RNA sequences in cytological preparations. We developed two methods to extend this technique to the transmission electron microscope level using mouse satellite DNA hybridization to whole mount metaphase chromosomes as the test system. The first method devised is a direct extension of standard light microscope level using mouse satellite DNA hybridization to whole mount metaphase chromosomes as the test system. The first method devised is a direct extension of standard light microscope in situ hybridization. Radioactively labeled complementary RNA (cRNA) is hybridized to metaphase chromosomes deposited on electron microscope grids and fixed in 70 percent ethanol vapor; hybridixation site are detected by autoradiography. Specific and intense labeling of chromosomal centromeric regions is observed even after relatively short exposure times. Inerphase nuclei present in some of the metaphase chromosome preparations also show defined paatterms of satellite DNA labeling which suggests that satellite-containing regions are associate with each other during interphase. The sensitivity of this method is estimated to at least as good as that at the light microscope level while the resolution is improved at least threefold. The second method, which circumvents the use of autoradiogrphic detection, uses biotin-labeled polynucleotide probes. After hybridization of these probes, either DNA or RNA, to fixed chromosomes on grids, hybrids are detected via reaction is improved at least threefold. The second method, which circumvents the use of autoradiographic detection, uses biotin-labeled polynucleotide probes. After hybridization of these probes, either DNA or RNA, to fixed chromosomes on grids, hybrids are detected via reaction with an antibody against biotin and secondary antibody adsorbed to the surface of over centromeric heterochromatin and along the associated peripheral fibers. Labeling is on average

THE SYNERGISTIC EFFECT OF HYBRID FLAME RETARDANTS ON PYROLYSIS BEHAVIOUR OF HYBRID COMPOSITE MATERIALS