WorldWideScience

Sample records for graded absorber structures

  1. Shock absorbing structure

    International Nuclear Information System (INIS)

    Kojima, Naoki; Matsushita, Kazuo.

    1992-01-01

    Small pieces of shock absorbers are filled in a space of a shock absorbing vessel which is divided into a plurality of sections by partitioning members. These sections function to prevent excess deformation or replacement of the fillers upon occurrence of falling accident. Since the shock absorbing small pieces in the shock absorbing vessel are filled irregularly, shock absorbing characteristics such as compression strength is not varied depending on the direction, but they exhibit excellent shock absorbing performance. They surely absorb shocks exerted on a transportation vessel upon falling or the like. If existing artificial fillers such as pole rings made of metal or ceramic and cut pieces such as alumium extrusion molding products are used as the shock absorbing pieces, they have excellent fire-proofness and cold resistance since the small pieces are inflammable and do not contain water. (T.M.)

  2. Optimization of Perfect Absorbers with Multilayer Structures

    Science.gov (United States)

    Li Voti, Roberto

    2018-02-01

    We study wide-angle and broadband perfect absorbers with compact multilayer structures made of a sequence of ITO and TiN layers deposited onto a silver thick layer. An optimization procedure is introduced for searching the optimal thicknesses of the layers so as to design a perfect broadband absorber from 400 nm to 750 nm, for a wide range of angles of incidence from 0{°} to 50{°}, for both polarizations and with a low emissivity in the mid-infrared. We eventually compare the performances of several optimal structures that can be very promising for solar thermal energy harvesting and collectors.

  3. Thermal expansion absorbing structure for pipeline

    International Nuclear Information System (INIS)

    Nagata, Takashi; Yamashita, Takuya.

    1995-01-01

    A thermal expansion absorbing structure for a pipeline is disposed to the end of pipelines to form a U-shaped cross section connecting a semi-circular torus shell and a short double-walled cylindrical tube. The U-shaped longitudinal cross-section is deformed in accordance with the shrinking deformation of the pipeline and absorbs thermal expansion. Namely, since the central lines of the outer and inner tubes of the double-walled cylindrical tube deform so as to incline, when the pipeline is deformed by thermal expansion, thermal expansion can be absorbed by a simple configuration thereby enabling to contribute to ensure the safety. Then, the entire length of the pipeline can greatly be shortened by applying it to the pipeline disposed in a high temperature state compared with a method of laying around a pipeline using only elbows, which has been conducted so far. Especially, when it is applied to a pipeline for an FBR-type reactor, the cost for the construction of a facility of a primary systems can greater be reduced. In addition, it can be applied to a pipeline for usual chemical plants and any other structures requiring absorption of deformation. (N.H.)

  4. Optimisation of energy absorbing liner for equestrian helmets. Part II: Functionally graded foam liner

    International Nuclear Information System (INIS)

    Cui, L.; Forero Rueda, M.A.; Gilchrist, M.D.

    2009-01-01

    The energy absorbing liner of safety helmets was optimised using finite element modelling. In this present paper, a functionally graded foam (FGF) liner was modelled, while keeping the average liner density the same as in a corresponding reference single uniform density liner model. Use of a functionally graded foam liner would eliminate issues regarding delamination and crack propagation between interfaces of different density layers which could arise in liners with discrete density variations. As in our companion Part I paper [Forero Rueda MA, Cui L, Gilchrist MD. Optimisation of energy absorbing liner for equestrian helmets. Part I: Layered foam liner. Mater Des [submitted for publication

  5. A shock absorber model for structure-borne noise analyses

    Science.gov (United States)

    Benaziz, Marouane; Nacivet, Samuel; Thouverez, Fabrice

    2015-08-01

    Shock absorbers are often responsible for undesirable structure-borne noise in cars. The early numerical prediction of this noise in the automobile development process can save time and money and yet remains a challenge for industry. In this paper, a new approach to predicting shock absorber structure-borne noise is proposed; it consists in modelling the shock absorber and including the main nonlinear phenomena responsible for discontinuities in the response. The model set forth herein features: compressible fluid behaviour, nonlinear flow rate-pressure relations, valve mechanical equations and rubber mounts. The piston, base valve and complete shock absorber model are compared with experimental results. Sensitivity of the shock absorber response is evaluated and the most important parameters are classified. The response envelope is also computed. This shock absorber model is able to accurately reproduce local nonlinear phenomena and improves our state of knowledge on potential noise sources within the shock absorber.

  6. Shock absorbing structure for nuclear fuel assemblies

    International Nuclear Information System (INIS)

    Jabsen, F.S.

    1981-01-01

    A hydraulic apparatus is described that absorbs shocks that may be applied to fuel assemblies. Spring pads mounted on the upper end fittings of the fuel assemblies have plungers that move within hollow guide posts attached to the upper grids of the fuel assemblies. (L.L.)

  7. Compositionally Graded Absorber for Efficient and Stable Near-Infrared-Transparent Perovskite Solar Cells.

    Science.gov (United States)

    Fu, Fan; Pisoni, Stefano; Weiss, Thomas P; Feurer, Thomas; Wäckerlin, Aneliia; Fuchs, Peter; Nishiwaki, Shiro; Zortea, Lukas; Tiwari, Ayodhya N; Buecheler, Stephan

    2018-03-01

    Compositional grading has been widely exploited in highly efficient Cu(In,Ga)Se 2 , CdTe, GaAs, quantum dot solar cells, and this strategy has the potential to improve the performance of emerging perovskite solar cells. However, realizing and maintaining compositionally graded perovskite absorber from solution processing is challenging. Moreover, the operational stability of graded perovskite solar cells under long-term heat/light soaking has not been demonstrated. In this study, a facile partial ion-exchange approach is reported to achieve compositionally graded perovskite absorber layers. Incorporating compositional grading improves charge collection and suppresses interface recombination, enabling to fabricate near-infrared-transparent perovskite solar cells with power conversion efficiency of 16.8% in substrate configuration, and demonstrate 22.7% tandem efficiency with 3.3% absolute gain when mechanically stacked on a Cu(In,Ga)Se 2 bottom cell. Non-encapsulated graded perovskite device retains over 93% of its initial efficiency after 1000 h operation at maximum power point at 60 °C under equivalent 1 sun illumination. The results open an avenue in exploring partial ion-exchange to design graded perovskite solar cells with improved efficiency and stability.

  8. Compositionally Graded Absorber for Efficient and Stable Near‐Infrared‐Transparent Perovskite Solar Cells

    Science.gov (United States)

    Pisoni, Stefano; Weiss, Thomas P.; Feurer, Thomas; Wäckerlin, Aneliia; Fuchs, Peter; Nishiwaki, Shiro; Zortea, Lukas; Tiwari, Ayodhya N.

    2018-01-01

    Abstract Compositional grading has been widely exploited in highly efficient Cu(In,Ga)Se2, CdTe, GaAs, quantum dot solar cells, and this strategy has the potential to improve the performance of emerging perovskite solar cells. However, realizing and maintaining compositionally graded perovskite absorber from solution processing is challenging. Moreover, the operational stability of graded perovskite solar cells under long‐term heat/light soaking has not been demonstrated. In this study, a facile partial ion‐exchange approach is reported to achieve compositionally graded perovskite absorber layers. Incorporating compositional grading improves charge collection and suppresses interface recombination, enabling to fabricate near‐infrared‐transparent perovskite solar cells with power conversion efficiency of 16.8% in substrate configuration, and demonstrate 22.7% tandem efficiency with 3.3% absolute gain when mechanically stacked on a Cu(In,Ga)Se2 bottom cell. Non‐encapsulated graded perovskite device retains over 93% of its initial efficiency after 1000 h operation at maximum power point at 60 °C under equivalent 1 sun illumination. The results open an avenue in exploring partial ion‐exchange to design graded perovskite solar cells with improved efficiency and stability. PMID:29593970

  9. Shock absorber in combination with a nuclear reactor core structure

    International Nuclear Information System (INIS)

    Housman, J.J.

    1976-01-01

    This invention relates to the provision of shock absorbers for use in blind control rod passages of a nuclear reactor core structure which are not subject to degradation. The shock absorber elements are made of a porous brittle carbonaceous material, a porous brittle ceramic material, or a porous brittle refractory oxide and have a void volume of between 30% and 70% of the total volume of the element for energy absorption by fracturing due to impact loading by a control rod. (UK)

  10. Burnable absorber rod releasable latching structure

    International Nuclear Information System (INIS)

    Gjertsen, R.K.; Wilson, J.F.

    1987-01-01

    An elongated nuclear reactivity control member, a releasable latching structure useful for releasably attaching the control member at an end to a top nozzle adapter plate of a nuclear fuel assembly is described comprising: (a) a mounting body including an inner plug portion attached to the end of the control member and an outer end portion disposed axially outward from the inner plug portion and the end of the member; and (b) a spring latch disposed about the mounting body and being attached to the outer end portion. The spring latch has at least one latch finger extending toward the inner plug portion of the body and is movable toward and away from the body between an outer latching position in which the finger is adapted to engage a fuel assembly top nozzle adapter plate and retain the elongated member in a stationary relationship with respect to the adapter plate and an inner unlatching position in which the finger is adapted to disengage from the adapter plate and allow removal of the member from the adapter plate

  11. Tuned mass absorbers on damped structures under random load

    DEFF Research Database (Denmark)

    Krenk, Steen; Høgsberg, Jan Becker

    2008-01-01

    the mass ratio alone, and the damping can be determined subsequently. Only approximate results are available for the influence of damping in the original structure, typically in the form of series expansions. In the present paper it is demonstrated that for typical mass ratios in the order of a few percent......A substantial literature exists on the optimal choice of parameters of a tuned mass absorber on a structure excited by a force or by ground acceleration with random characteristics in the form of white noise. In the absence of structural damping the optimal frequency tuning is determined from...... for the response variance of a structure with initial damping in terms of the mass ratio and both damping ratios. Within this format the optimal tuning of the absorber turns out to be independent of the structural damping, and a simple explicit expression is obtained for the equivalent total damping....

  12. Organic solar cells with graded absorber layers processed from nanoparticle dispersions.

    Science.gov (United States)

    Gärtner, Stefan; Reich, Stefan; Bruns, Michael; Czolk, Jens; Colsmann, Alexander

    2016-03-28

    The fabrication of organic solar cells with advanced multi-layer architectures from solution is often limited by the choice of solvents since most organic semiconductors dissolve in the same aromatic agents. In this work, we investigate multi-pass deposition of organic semiconductors from eco-friendly ethanol dispersion. Once applied, the nanoparticles are insoluble in the deposition agent, allowing for the application of further nanoparticulate layers and hence for building poly(3-hexylthiophene-2,5-diyl):indene-C60 bisadduct absorber layers with vertically graded polymer and conversely graded fullerene concentration. Upon thermal annealing, we observe some degrees of polymer/fullerene interdiffusion by means of X-ray photoelectron spectroscopy and Kelvin probe force microscopy. Replacing the common bulk-heterojunction by such a graded photo-active layer yields an enhanced fill factor of the solar cell due to an improved charge carrier extraction, and consequently an overall power conversion efficiency beyond 4%. Wet processing of such advanced device architectures paves the way for a versatile, eco-friendly and industrially feasible future fabrication of organic solar cells with advanced multi-layer architectures.

  13. Synthesis and microwave absorbing characteristics of functionally graded carbonyl iron/polyurethane composites

    Directory of Open Access Journals (Sweden)

    R. B. Yang

    2016-05-01

    Full Text Available Radar absorbing materials (RAMs also known as microwave absorbers, which can absorb and dissipate incident electromagnetic wave, are widely used in the fields of radar-cross section reduction, electromagnetic interference (EMI reduction and human health protection. In this study, the synthesis of functionally graded material (FGM (CI/Polyurethane composites, which is fabricated with semi-sequentially varied composition along the thickness, is implemented with a genetic algorithm (GA to optimize the microwave absorption efficiency and bandwidth of FGM. For impedance matching and broad-band design, the original 8-layered FGM was obtained by the GA method to calculate the thickness of each layer for a sequential stacking of FGM from 20, 30, 40, 50, 60, 65, 70 and 75 wt% of CI fillers. The reflection loss of the original 8-layered FGM below –10 dB can be obtained in the frequency range of 5.12∼18 GHz with a total thickness of 9.66 mm. Further optimization reduces the number of the layers and the stacking sequence of the optimized 4-layered FGM is 20, 30, 65, 75 wt% with thickness of 0.8, 1.6, 0.6 and 1.0 mm, respectively. The synthesis and measurement of the optimized 4-layered FGM with a thickness of 4 mm reveal a minimum reflection loss of –25.2 dB at 6.64 GHz and its bandwidth below – 10 dB is larger than 12.8 GHz.

  14. Metal–insulator–metal light absorber: a continuous structure

    International Nuclear Information System (INIS)

    Yan, M

    2013-01-01

    A type of light absorber made of continuous layers of metal and dielectric films is studied. The metal films can have thicknesses close to their skin depths in the wavelength range concerned, which allows for both light transmission and reflection. Resonances induced by multiple reflections in the structure, when combined with the inherent lossy nature of metals, result in strong absorption spectral features. An eigen-mode analysis is carried out for the plasmonic multilayer nanostructures which provides a generic understanding of the absorption features. Experimentally, the calculation is verified by a reflection measurement with a representative structure. Such an absorber is simple to fabricate. The highly efficient absorption characteristics can be potentially deployed for optical filter designs, sensors, accurate photothermal temperature control in a micro-environment and even for backscattering reduction of small particles, etc. (paper)

  15. Pharmaceutical/food grade titanium dioxide particles are absorbed into the bloodstream of human volunteers.

    Science.gov (United States)

    Pele, Laetitia C; Thoree, Vinay; Bruggraber, Sylvaine F A; Koller, Dagmar; Thompson, Richard P H; Lomer, Miranda C; Powell, Jonathan J

    2015-09-02

    Exposure to persistent engineered nano and micro particles via the oral route is well established. Animal studies have demonstrated that, once ingested, a small proportion of such particles translocate from the gastrointestinal tract to other tissues. Exposure to titanium dioxide is widespread via the oral route, but only one study has provided indirect evidence (total titanium analyses) of absorption into the blood stream in humans. We sought to replicate these observations and to provide additional evidence for particulate uptake. Human volunteers with normal intestinal permeability were orally administered 100 mg pharmaceutical/food grade titanium dioxide. Blood samples were collected from 0.5 to 10 h post ingestion and analysed for the presence of reflectant bodies (particles) by dark field microscopy, and for total titanium by inductively coupled plasma mass spectrometry (ICP-MS). Blood film analyses implied early absorption of particles (2 h) with a peak maximum at 6 h following ingestion. The presence of these reflectant particles in blood roughly mirrored the levels of total titanium by ICP-MS, providing good evidence for the latter being a measure of whole particle (titanium dioxide) absorption. This study shows that a fraction of pharmaceutical/food grade titanium dioxide is absorbed systemically by humans following ingestion. It confirms that at least two routes of particle uptake may exist in the human gut- one proximal and one distal. Further work should quantify human exposure and uptake of such persistent particles.

  16. An absorbing phase transition from a structured active particle phase

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, Cristobal [Instituto Mediterraneo de Estudios Avanzados IMEDEA (CSIC-UIB), Campus de la Universidad de las Islas Baleares, E-07122 Palma de Mallorca (Spain); Ramos, Francisco [Departamento de Electromagnetismo y Fisica de la Materia and Instituto de Fisica Teorica y Computacional Carlos I, Facultad de Ciencias, Universidad de Granada, 18071 Granada (Spain); Hernandez-GarcIa, Emilio [Instituto Mediterraneo de Estudios Avanzados IMEDEA (CSIC-UIB), Campus de la Universidad de las Islas Baleares, E-07122 Palma de Mallorca (Spain)

    2007-02-14

    In this work we study the absorbing state phase transition of a recently introduced model for interacting particles with neighbourhood-dependent reproduction rates. The novelty of the transition is that as soon as the active phase is reached by increasing a control parameter a periodically arranged structure of particle clusters appears. A numerical study in one and two dimensions shows that the system falls into the directed percolation universality class.

  17. Shock Absorbers Save Structures and Lives during Earthquakes

    Science.gov (United States)

    2015-01-01

    With NASA funding, North Tonawanda, New York-based Taylor Devices Inc. developed fluidic shock absorbers to safely remove the fuel and electrical connectors from the space shuttles during launch. The company is now employing the technology as seismic dampers to protect structures from earthquakes. To date, 550 buildings and bridges have the dampers, and not a single one has suffered damage in the wake of an earthquake.

  18. Regeneration performance of CO2-rich solvents by using membrane vacuum regeneration technology: Relationships between absorbent structure and regeneration efficiency

    International Nuclear Information System (INIS)

    Yan, Shuiping; Fang, Mengxiang; Wang, Zhen; Luo, Zhongyang

    2012-01-01

    Highlights: ► MVR may be viable to successfully use less valuable heat to replace high grade steam. ► Increasing OH and amine groups will increase the regeneration efficiency. ► Absorbents with a four carbon chain length will be more attractive to MVR. ► Amino acid salts will be more appropriate for MVR. ► HRM conducted at ambient pressure and low temperature is inferior to MVR. -- Abstract: In order to give a better understanding for the selection of suitable absorbents for the novel membrane vacuum regeneration technology (MVR) which has the potential to reduce CO 2 energy requirement by utilizing the waste heat or low-grade energy, an experimental study to determine the relationships between chemical structure and vacuum regeneration behavior of CO 2 absorbents at 70 °C and 10 kPa was performed. Eleven typical absorbents with different functional groups in their chemical structures were investigated in terms of vacuum regeneration efficiencies. Results showed that the regeneration efficiency decreased with an increase of number of activated hydrogen atom in amine group and decreased with the number of hydroxyl group. Especially, more attention should be paid to these alkanolamines with one hydrogen atom in amine group and two or more hydroxyl groups in the structures due to their better comprehensive performance in regeneration, absorbent loss and CO 2 absorption aspects. Increasing the carbon chain length and amine groups in the absorbent structure contributed to the improvement of regeneration performance and reduction of absorbent volatile loss. These absorbents with a four carbon chain length bonded at amine group might be more attractive to MVR. Furthermore, polyamines were superior to monoamines in terms of higher regeneration efficiencies and lower absorbent losses. Additionally, the individual effects of the potassium carboxylate group and hydroxymethylene group were also compared in this study. Results showed that amino acid salts were more

  19. Wave-Structure Interactions on Point Absorbers - an experimental study

    DEFF Research Database (Denmark)

    Jakobsen, Morten Møller

    used in the case studies is a pitching point absorber (Wavestar). The central part of the thesis deals with the challenges, choices, and experi- ences gained during the Ph.D. The more in-depth technical details and results are presented in peer-reviewed publications and technical reports. The chal...... that combines waves and current in a meaningful way. The method needs to be inexpensive, easy to implement and reduce the turbulence without distorting the incident waves in a detrimental way....

  20. Polarization insensitive metamaterial absorber based on E-shaped all-dielectric structure

    Directory of Open Access Journals (Sweden)

    Liyang Li

    2015-03-01

    Full Text Available In this paper, we designed a metamaterial absorber performed in microwave frequency band. This absorber is composed of E-shaped dielectrics which are arranged along different directions. The E-shaped all-dielectric structure is made of microwave ceramics with high permittivity and low loss. Within about 1 GHz frequency band, more than 86% absorption efficiency was observed for this metamaterial absorber. This absorber is polarization insensitive and is stable for incident angles. It is figured out that the polarization insensitive absorption is caused by the nearly located varied resonant modes which are excited by the E-shaped all-dielectric resonators with the same size but in the different direction. The E-shaped dielectric absorber contains intensive resonant points. Our research work paves a way for designing all-dielectric absorber.

  1. The design of impact absorbing structures for additive manufacture

    International Nuclear Information System (INIS)

    Brennan-Craddock, J; Brackett, D; Wildman, R; Hague, R

    2012-01-01

    Additive manufacturing (AM) is increasingly becoming a viable manufacturing process due to dramatic advantages that it facilitates in the area of design complexity. This paper investigates the potential of additively manufactured lattice structures for the application of tailored impact absorption specifically for conformal body protection. It explores lattice cell types based on foam microstructures and assesses their suitability for impact absorption. The effect of varying the cell strut edge design is also investigated. The implications of scaling these cells up for AM are discussed as well as the design issues regarding the handling of geometric complexity and the requirement for body conformity. The suitability of AM materials for this application is also discussed.

  2. The Time Structure of Hadronic Showers in Highly Granular Calorimeters with Tungsten and Steel Absorbers

    CERN Document Server

    Adloff, C.; Chefdeville, M.; Drancourt, C.; Gaglione, R.; Geffroy, N.; Karyotakis, Y.; Koletsou, I.; Prast, J.; Vouters, G.; Repond, J.; Schlereth, J.; Xia, L.; Baldolemar, E.; Li, J.; Park, S.T.; Sosebee, M.; White, A.P.; Yu, J.; Eigen, G.; Thomson, M.A.; Ward, D.R.; Benchekroun, D.; Hoummada, A.; Khoulaki, Y.; Apostolakis, J.; Arfaoui, A.; Benoit, M.; Dannheim, D.; Elsener, K.; Folger, G.; Grefe, C.; Ivantchenko, V.; Killenberg, M.; Klempt, W.; van der Kraaij, E.; Linssen, L.; Lucaci-Timoce, A.-I.; Münnich, A.; Poss, S.; Ribon, A.; Roloff, P.; Sailer, A.; Schlatter, D.; Sicking, E.; Strube, J.; Uzhinskiy, V.; Carloganu, C.; Gay, P.; Manen, S.; Royer, L.; Cornett, U.; David, D.; Ebrahimi, A.; Falley, G.; Feege, N.; Gadow, K.; Göttlicher, P.; Günter, C.; Hartbrich, O.; Hermberg, B.; Karstensen, S.; Krivan, F.; Krüger, K.; Lu, S.; Lutz, B.; Morozov, S.; Morgunov, V.; Neubüser, C.; Reinecke, M.; Sefkow, F.; Smirnov, P.; Terwort, M.; Fagot, A.; Tytgat, M.; Zaganidis, N.; Hostachy, J.-Y.; Morin, L.; Garutti, E.; Laurien, S.; Marchesini, I.; Matysek, M.; Ramilli, M.; Briggl, K.; Eckert, P.; Harion, T.; Schultz-Coulon, H.-Ch.; Shen, W.; Stamen, R.; Chang, S.; Khan, A.; Kim, D.H.; Kong, D.J.; Oh, Y.D.; Bilki, B.; Norbeck, E.; Northacker, D.; Onel, Y.; Wilson, G.W.; Kawagoe, K.; Miyazaki, Y.; Sudo, Y.; Ueno, H.; Yoshioka, T.; Dauncey, P.D.; Cortina Gil, E.; Mannai, S.; Baulieu, G.; Calabria, P.; Caponetto, L.; Combaret, C.; Della Negra, R.; Ete, R.; Grenier, G.; Han, R.; Ianigro, J-C.; Kieffer, R.; Laktineh, I.; Lumb, N.; Mathez, H.; Mirabito, L.; Petrukhin, A.; Steen, A.; Tromeur, W.; Vander Donckt, M.; Zoccarato, Y.; Berenguer Antequera, J.; Calvo Alamillo, E.; Fouz, M.-C.; Puerta-Pelayo, J.; Corriveau, F.; Bobchenko, B.; Chadeeva, M.; Danilov, M.; Epifantsev, A.; Markin, O.; Mizuk, R.; Novikov, E.; Rusinov, V.; Tarkovsky, E.; Kozlov, V.; Soloviev, Y.; Besson, D.; Buzhan, P.; Ilyin, A.; Kantserov, V.; Kaplin, V.; Popova, E.; Tikhomirov, V.; Gabriel, M.; Kiesling, C.; Seidel, K.; Simon, F.; Soldner, C.; Szalay, M.; Tesar, M.; Weuste, L.; Amjad, M.S.; Bonis, J.; Conforti di Lorenzo, S.; Cornebise, P.; Fleury, J.; Frisson, T.; van der Kolk, N.; Richard, F.; Pöschl, R.; Rouene, J.; Anduze, M.; Balagura, V.; Becheva, E.; Boudry, V.; Brient, J-C.; Cornat, R.; Frotin, M.; Gastaldi, F.; Guliyev, E.; Haddad, Y.; Magniette, F.; Ruan, M.; Tran, T.H.; Videau, H.; Callier, S.; Dulucq, F.; Martin-Chassard, G.; de la Taille, Ch.; Raux, L.; Seguin-Moreau, N.; Zacek, J.; Cvach, J.; Gallus, P.; Havranek, M.; Janata, M.; Kvasnicka, J.; Lednicky, D.; Marcisovsky, M.; Polak, I.; Popule, J.; Tomasek, L.; Tomasek, M.; Ruzicka, P.; Sicho, P.; Smolik, J.; Vrba, V.; Zalesak, J.; Belhorma, B.; Ghazlane, H.; Kotera, K.; Ono, H.; Takeshita, T.; Uozumi, S.; Chai, J.S.; Song, H.S.; Lee, S.H.; Götze, M.; Sauer, J.; Weber, S.; Zeitnitz, C.

    2014-01-01

    The intrinsic time structure of hadronic showers influences the timing capability and the required integration time of hadronic calorimeters in particle physics experiments, and depends on the active medium and on the absorber of the calorimeter. With the CALICE T3B experiment, a setup of 15 small plastic scintillator tiles read out with Silicon Photomultipliers, the time structure of showers is measured on a statistical basis with high spatial and temporal resolution in sampling calorimeters with tungsten and steel absorbers. The results are compared to GEANT4 (version 9.4 patch 03) simulations with different hadronic physics models. These comparisons demonstrate the importance of using high precision treatment of low-energy neutrons for tungsten absorbers, while an overall good agreement between data and simulations for all considered models is observed for steel.

  3. Bicrossproduct structure and graded contractions of deformed algebras

    International Nuclear Information System (INIS)

    Perez Bueno, J.C.

    1997-01-01

    It is shown that all members in the family of deformed Hopf algebras corresponding to the graded contractions of the inhomogeneous algebras iso(p,q), p + q = N, have a bicrossproduct structure. (author)

  4. Chapter 4:Grading and properties of hardwood structural lumber

    Science.gov (United States)

    David W. Green

    2005-01-01

    Structural lumber markets have traditionally been dominated by softwood species. Historically, however, hardwood species have been extensively used for certain structural products such as timbers for railway and highway bridges, railway ties, mine timbers, and for pallets and containers. In the 1920s, when uniform procedures were first developed for structural grading...

  5. Band structures in fractal grading porous phononic crystals

    Science.gov (United States)

    Wang, Kai; Liu, Ying; Liang, Tianshu; Wang, Bin

    2018-05-01

    In this paper, a new grading porous structure is introduced based on a Sierpinski triangle routine, and wave propagation in this fractal grading porous phononic crystal is investigated. The influences of fractal hierarchy and porosity on the band structures in fractal graidng porous phononic crystals are clarified. Vibration modes of unit cell at absolute band gap edges are given to manifest formation mechanism of absolute band gaps. The results show that absolute band gaps are easy to form in fractal structures comparatively to the normal ones with the same porosity. Structures with higher fractal hierarchies benefit multiple wider absolute band gaps. This work provides useful guidance in design of fractal porous phononic crystals.

  6. A broadband frequency-tunable dynamic absorber for the vibration control of structures

    International Nuclear Information System (INIS)

    Komatsuzaki, T; Inoue, T; Terashima, O

    2016-01-01

    A passive-type dynamic vibration absorber (DVA) is basically a mass-spring system that suppresses the vibration of a structure at a particular frequency. Since the natural frequency of the DVA is usually tuned to a frequency of particular excitation, the DVA is especially effective when the excitation frequency is close to the natural frequency of the structure. Fixing the physical properties of the DVA limits the application to a narrowband, harmonically excited vibration problem. A frequency-tunable DVA that can modulate its stiffness provides adaptability to the vibration control device against non-stationary disturbances. In this paper, we suggest a broadband frequency-tunable DVA whose natural frequency can be extended by 300% to the nominal value using the magnetorheological elastomers (MREs). The frequency adjustability of the proposed absorber is first shown. The real-time vibration control performance of the frequency-tunable absorber for an acoustically excited plate having multiple resonant peaks is then evaluated. Investigations show that the vibration of the structure can be effectively reduced with an improved performance by the DVA in comparison to the conventional passive- type absorber. (paper)

  7. Multistep Cylindrical Structure Analysis at Normal Incidence Based on Water-Substrate Broadband Metamaterial Absorbers

    Science.gov (United States)

    Fang, Chonghua

    2018-01-01

    A new multistep cylindrical structure based on water-substrate broadband metamaterial absorbers is designed to reduce the traditional radar cross-section (RCS) of a rod-shaped object. The proposed configuration consists of two distinct parts. One of these components is formed by a four-step cylindrical metal structure, whereas the other one is formed by a new water-substrate broadband metamaterial absorber. The designed structure can significantly reduce the radar cross section more than 10 dB from 4.58 to 18.42 GHz which is the 86.5 % bandwidth of from C-band to 20 GHz. The results of measurement show reasonably good accordance with the simulated ones, which verifies the ability and effect of the proposed design.

  8. Imperfectly geometric shapes of nanograting structures as solar absorbers with superior performance for solar cells.

    Science.gov (United States)

    Nguyen-Huu, Nghia; Cada, Michael; Pištora, Jaromír

    2014-03-10

    The expectation of perfectly geometric shapes of subwavelength grating (SWG) structures such as smoothness of sidewalls and sharp corners and nonexistence of grating defects is not realistic due to micro/nanofabrication processes. This work numerically investigates optical properties of an optimal solar absorber comprising a single-layered silicon (Si) SWG deposited on a finite Si substrate, with a careful consideration given to effects of various types of its imperfect geometry. The absorptance spectra of the solar absorber with different geometric shapes, namely, the grating with attached nanometer-sized features at the top and bottom of sidewalls and periodic defects within four and ten grating periods are investigated comprehensively. It is found that the grating with attached features at the bottom absorbs more energy than both the one at the top and the perfect grating. In addition, it is shown that the grating with defects in each fourth period exhibits the highest average absorptance (91%) compared with that of the grating having defects in each tenth period (89%), the grating with attached features (89%), and the perfect one (86%). Moreover, the results indicate that the absorptance spectrum of the imperfect structures is insensitive to angles of incidence. Furthermore, the absorptance enhancement is clearly demonstrated by computing magnetic field, energy density, and Poynting vector distributions. The results presented in this study prove that imperfect geometries of the nanograting structure display a higher absorptance than the perfect one, and provide such a practical guideline for nanofabrication capabilities necessary to be considered by structure designers.

  9. Test of the electronic structure of Fe(100) by absorbed current spectroscopy

    International Nuclear Information System (INIS)

    Kisker, E.; Kirby, R.E.; Garwin, E.L.; King, F.K.

    1984-10-01

    The absorbed electron current for a clean Fe(100) surface as a function of energy rises step-like at the vacuum-energy cutoff with an absorption close to 1. The smooth decrease of absorbed current at higher electron energy due to secondary electron emission is superimposed by a considerable amount of fine structure, the amplitude of which decreases with increasing energy. These features are found in good agreement with the results of a calculation of the elastic part of the electron reflection coefficient. Further, they are compared with the ferromagnetic electronic bulk bandstructure calculated above the vacuum energy. From the comparison with the experimental data, the energy dependence of the real and imaginary parts of the inner potential is determined

  10. Moving localized structures and spatial patterns in quadratic media with a saturable absorber

    International Nuclear Information System (INIS)

    Tlidi, M; Taki, M; Berre, M Le; Reyssayre, E; Tallet, A; Di Menza, L

    2004-01-01

    For near the first lasing threshold, we give a detailed derivation of a real order parameter equation for the degenerate optical parametric oscillator with a saturable absorber. For this regime, we study analytically the role of the quasi-homogeneous neutral mode in the pattern formation process. We show that this effect stabilized the hexagonal patterns below the lasing threshold. More importantly, we find numerically that when Turing and Hopf bifurcations interact, a stable moving asymmetric localized structure with a constant transverse velocity is generated. The formation of the moving localized structures is analysed for both the propagation and the mean field models. A quantitative confrontation of the two models is discussed

  11. Active vibration absorber for the CSI evolutionary model - Design and experimental results. [Controls Structures Interaction

    Science.gov (United States)

    Bruner, Anne M.; Belvin, W. Keith; Horta, Lucas G.; Juang, Jer-Nan

    1991-01-01

    The development of control of large flexible structures technology must include practical demonstrations to aid in the understanding and characterization of controlled structures in space. To support this effort, a testbed facility has been developed to study practical implementation of new control technologies under realistic conditions. The paper discusses the design of a second order, acceleration feedback controller which acts as an active vibration absorber. This controller provides guaranteed stability margins for collocated sensor/actuator pairs in the absence of sensor/actuator dynamics and computational time delay. Experimental results in the presence of these factors are presented and discussed. The robustness of this design under model uncertainty is demonstrated.

  12. The structural grading of young South African grown Pinus patula ...

    African Journals Online (AJOL)

    The young P. patula timber tested in this study had good bending strength (MOR) properties with higher characteristic grade values than required. The timber, however, had low stiffness and did not comply with the SANS 10163-1 requirements for mean modulus of elasticity on edge (MOEedge) for any of the structural ...

  13. Plasmonic Structure Enhanced Exciton Generation at the Interface between the Perovskite Absorber and Copper Nanoparticles

    Science.gov (United States)

    Lin, Kuen-Feng; Chiang, Chien-Hung; Wu, Chun-Guey

    2014-01-01

    The refractive index and extinction coefficient of a triiodide perovskite absorber (TPA) were obtained by fitting the transmittance spectra of TPA/PEDOT:PSS/ITO/glass using the transfer matrix method. Cu nanoplasmonic structures were designed to enhance the exciton generation in the TPA and to simultaneously reduce the film thickness of the TPA. Excitons were effectively generated at the interface between TPA and Cu nanoparticles, as observed through the 3D finite-difference time-domain method. The exciton distribution is advantageous for the exciton dissociation and carrier transport. PMID:25295290

  14. Transition metal atoms absorbed on MoS2/h-BN heterostructure: stable geometries, band structures and magnetic properties.

    Science.gov (United States)

    Wu, Yanbing; Huang, Zongyu; Liu, Huating; He, Chaoyu; Xue, Lin; Qi, Xiang; Zhong, Jianxin

    2018-06-15

    We have studied the stable geometries, band structures and magnetic properties of transition-metal (V, Cr, Mn, Fe, Co and Ni) atoms absorbed on MoS2/h-BN heterostructure systems by first-principles calculations. By comparing the adsorption energies, we find that the adsorbed transition metal (TM) atoms prefer to stay on the top of Mo atoms. The results of the band structure without spin-orbit coupling (SOC) interaction indicate that the Cr-absorbed systems behave in a similar manner to metals, and the Co-absorbed system exhibits a half-metallic state. We also deduce that the V-, Mn-, Fe-absorbed systems are semiconductors with 100% spin polarization at the HOMO level. The Ni-absorbed system is a nonmagnetic semiconductor. In contrast, the Co-absorbed system exhibits metallic state, and the bandgap of V-absorbed system decreases slightly according to the SOC calculations. In addition, the magnetic moments of all the six TM atoms absorbed on the MoS2/h-BN heterostructure systems decrease when compared with those of their free-standing states.

  15. An FFT-accelerated fdtd scheme with exact absorbing conditions for characterizing axially symmetric resonant structures

    KAUST Repository

    Sirenko, Kostyantyn

    2011-01-01

    An accurate and efficient finite-difference time-domain (FDTD) method for characterizing transient waves interactions on axially symmetric structures is presented. The method achieves its accuracy and efficiency by employing localized and/or fast Fourier transform (FFT) accelerated exact absorbing conditions (EACs). The paper details the derivation of the EACs, discusses their implementation and discretization in an FDTD method, and proposes utilization of a blocked-FFT based algorithm for accelerating the computation of temporal convolutions present in nonlocal EACs. The proposed method allows transient analyses to be carried for long time intervals without any loss of accuracy and provides reliable numerical data pertinent to physical processes under resonant conditions. This renders the method highly useful in characterization of high-Q microwave radiators and energy compressors. Numerical results that demonstrate the accuracy and efficiency of the method are presented.

  16. On functionally-graded crashworthy shape of conical structures for multiple load cases

    International Nuclear Information System (INIS)

    Pang, Tong; Li, Yinfeng; Kang, Hehe; Sun, Guangyong; Li, Qing; Fang, Jianguang

    2017-01-01

    Many studies on energy absorbers have been focused on tapered tubes because they have significant advantages in crashworthiness and provide a desired constant load-deflection response. However, few studies have been reported on tapered tubes with nonlinearly- variable diameters along the longitudinal direction. This paper presents thin-walled Functionally graded tapered tube (FGTT) with a diameter varying nonlinearly subject to axial (0°) and oblique (10°, 20°, 30°) impacts. To explore the advantages of FGTT, conventional Straight/Conical circular tube (SCT/CCT) with the same mass are compared; and FGTTs with a gradient exponent n > 1 are found to be preferable to others in terms of energy absorption capacity under small impact angles. Then, crashworthiness analyses of different crushing distances are conducted and it is found that under a large impact angle (e.g. 20°, 30°), FGTT with a short crushing distance (e.g. 40mm) have a higher mean crashing force than long crushing distance (e.g. 120 mm), especially for n > 1. In addition, the effect of geometric parameters, such as the gradient exponent n and diameter range ΔD between top (incident) and bottom (distal) diameters of FGTTs, are also studied and it is found that the FGTT with ΔD = 40 mm and n > 1 exhibits better crashworthiness than the others under small impact angles (0°, 10°). This paper demonstrates that such FGTT structures have a certain potential to be an energy absorber.

  17. On functionally-graded crashworthy shape of conical structures for multiple load cases

    Energy Technology Data Exchange (ETDEWEB)

    Pang, Tong; Li, Yinfeng [Hunan University, Changsha (China); Kang, Hehe [Chongqing Changan Automobile Co. Ltd., Chongqing (China); Sun, Guangyong; Li, Qing [The University of Sydney, Sydney (Australia); Fang, Jianguang [University of Technology Sydney, Sydney (Australia)

    2017-06-15

    Many studies on energy absorbers have been focused on tapered tubes because they have significant advantages in crashworthiness and provide a desired constant load-deflection response. However, few studies have been reported on tapered tubes with nonlinearly- variable diameters along the longitudinal direction. This paper presents thin-walled Functionally graded tapered tube (FGTT) with a diameter varying nonlinearly subject to axial (0°) and oblique (10°, 20°, 30°) impacts. To explore the advantages of FGTT, conventional Straight/Conical circular tube (SCT/CCT) with the same mass are compared; and FGTTs with a gradient exponent n > 1 are found to be preferable to others in terms of energy absorption capacity under small impact angles. Then, crashworthiness analyses of different crushing distances are conducted and it is found that under a large impact angle (e.g. 20°, 30°), FGTT with a short crushing distance (e.g. 40mm) have a higher mean crashing force than long crushing distance (e.g. 120 mm), especially for n > 1. In addition, the effect of geometric parameters, such as the gradient exponent n and diameter range ΔD between top (incident) and bottom (distal) diameters of FGTTs, are also studied and it is found that the FGTT with ΔD = 40 mm and n > 1 exhibits better crashworthiness than the others under small impact angles (0°, 10°). This paper demonstrates that such FGTT structures have a certain potential to be an energy absorber.

  18. High-volume use of self-cementing spray dry absorber material for structural applications

    Science.gov (United States)

    Riley, Charles E.

    Spray dry absorber (SDA) material, or spray dryer ash, is a byproduct of energy generation by coal combustion and sulfur emissions controls. Like any resource, it ought to be used to its fullest potential offsetting as many of the negative environmental impacts of coal combustion as possible throughout its lifecycle. Its cementitious and pozzolanic properties suggest it be used to augment or replace another energy and emissions intensive product: Portland cement. There is excellent potential for spray dryer ash to be used beneficially in structural applications, which will offset CO2 emissions due to Portland cement production, divert landfill waste by further utilizing a plentiful coal combustion by-product, and create more durable and sustainable structures. The research into beneficial use applications for SDA material is relatively undeveloped and the material is highly underutilized. This dissertation explored a specific self-cementing spray dryer ash for use as a binder in structural materials. Strength and stiffness properties of hydrated spray dryer ash mortars were improved by chemical activation with Portland cement and reinforcement with polymer fibers from automobile tire recycling. Portland cement at additions of five percent of the cementitious material was found to function effectively as an activating agent for spray dryer ash and had a significant impact on the hardened properties. The recycled polymer fibers improved the ductility and toughness of the material in all cases and increased the compressive strength of weak matrix materials like the pure hydrated ash. The resulting hardened materials exhibited useful properties that were sufficient to suggest that they be used in structural applications such as concrete, masonry block, or as a hydraulic cement binder. While the long-term performance characteristics remain to be investigated, from an embodied-energy and carbon emissions standpoint the material investigated here is far superior to

  19. Absorbed dose evaluation based on a computational voxel model incorporating distinct cerebral structures

    Energy Technology Data Exchange (ETDEWEB)

    Brandao, Samia de Freitas; Trindade, Bruno; Campos, Tarcisio P.R. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil)]. E-mail: samiabrandao@gmail.com; bmtrindade@yahoo.com; campos@nuclear.ufmg.br

    2007-07-01

    Brain tumors are quite difficult to treat due to the collateral radiation damages produced on the patients. Despite of the improvements in the therapeutics protocols for this kind of tumor, involving surgery and radiotherapy, the failure rate is still extremely high. This fact occurs because tumors can not often be totally removed by surgery since it may produce some type of deficit in the cerebral functions. Radiotherapy is applied after the surgery, and both are palliative treatments. During radiotherapy the brain does not absorb the radiation dose in homogeneous way, because the various density and chemical composition of tissues involved. With the intention of evaluating better the harmful effects caused by radiotherapy it was developed an elaborated cerebral voxel model to be used in computational simulation of the irradiation protocols of brain tumors. This paper presents some structures function of the central nervous system and a detailed cerebral voxel model, created in the SISCODES program, considering meninges, cortex, gray matter, white matter, corpus callosum, limbic system, ventricles, hypophysis, cerebellum, brain stem and spinal cord. The irradiation protocol simulation was running in the MCNP5 code. The model was irradiated with photons beam whose spectrum simulates a linear accelerator of 6 MV. The dosimetric results were exported to SISCODES, which generated the isodose curves for the protocol. The percentage isodose curves in the brain are present in this paper. (author)

  20. Fraction of a dose absorbed estimation for structurally diverse low solubility compounds.

    Science.gov (United States)

    Sugano, Kiyohiko

    2011-02-28

    The purpose of the present study was to investigate the prediction accuracy of the fully mechanistic gastrointestinal unified theoretical (GUT) framework for in vivo oral absorption of low solubility drugs. Solubility in biorelevant media, molecular weight, logP(oct), pK(a), Caco-2 permeability, dose and particle size were used as the input parameters. To neglect the effect of the low stomach pH on dissolution of a drug, the fraction of a dose absorbed (Fa%) of undissociable and free acids were used. In addition, Fa% of free base drugs with the high pH stomach was also included to increase the number of model drugs. In total twenty nine structurally diverse compounds were used as the model drugs. Fa% data at several doses and particle sizes in humans and dogs were collated from the literature (total 110 Fa% data). In approximately 80% cases, the prediction error was within 2 fold, suggesting that the GUT framework has practical predictability for drug discovery, but not for drug development. The GUT framework appropriately captured the dose and particle size dependency of Fa% as the particle drifting effect was taken into account. It should be noted that the present validation results cannot be applied for salt form cases and other special formulations such as solid dispersions and emulsion formulations. Copyright © 2010 Elsevier B.V. All rights reserved.

  1. Potential of Reinforced Indonesian Glulam Beams Using Grade I (Bengkirai, Grade II (Kamper, Grade III (Nyatoh Woods for Use in Structural Wood Design

    Directory of Open Access Journals (Sweden)

    Saptahari Sugiri

    2016-05-01

    Full Text Available Wood is a natural resource that is renewable and available in various species in tropical countries. Its abundancy in nature makes it easy to obtain, thus making it a nature friendly material for use in construction. Indonesia is the most important source of tropical wood in the world after Brazil, making the use of wood for structural elements very desirable. It is estimated that 4000 different varieties of wood exist in Indonesia. This estimate is based on the herbarium species collected by the Forestry Research Institute, currently counting nearly 4000 types of trees with a diameter of more than 40 cm. In the Indonesian wood structure code, the strength of woods is divided into 3 grades (grade I, II and III. This paper presents an evaluation of the mechanical properties of glulam wood sourced from native Indonesian timber: Bengkirai wood (grade I, Kamper wood (grade II, and Nyatoh wood (grade III, thus proving the potential for Indonesian wood as industrial structural elements in wooden constructions.

  2. Absorbed dose estimates to structures of the brain and head using a high-resolution voxel-based head phantom

    International Nuclear Information System (INIS)

    Evans, Jeffrey F.; Blue, Thomas E.; Gupta, Nilendu

    2001-01-01

    The purpose of this article is to demonstrate the viability of using a high-resolution 3-D head phantom in Monte Carlo N-Particle (MCNP) for boron neutron capture therapy (BNCT) structure dosimetry. This work describes a high-resolution voxel-based model of a human head and its use for calculating absorbed doses to the structures of the brain. The Zubal head phantom is a 3-D model of a human head that can be displayed and manipulated on a computer. Several changes were made to the original head phantom which now contains over 29 critical structures of the brain and head. The modified phantom is a 85x109x120 lattice of voxels, where each voxel is 2.2x2.2x1.4 mm 3 . This model was translated into MCNP lattice format. As a proof of principle study, two MCNP absorbed dose calculations were made (left and right lateral irradiations) using a uniformly distributed neutron disk source with an 1/E energy spectrum. Additionally, the results of these two calculations were combined to estimate the absorbed doses from a bilateral irradiation. Radiobiologically equivalent (RBE) doses were calculated for all structures and were normalized to 12.8 Gy-Eq. For a left lateral irradiation, the left motor cortex receives the limiting RBE dose. For a bilateral irradiation, the insula cortices receive the limiting dose. Among the nonencephalic structures, the parotid glands receive RBE doses that were within 15% of the limiting dose

  3. Shock absorber

    International Nuclear Information System (INIS)

    Housman, J.J.

    1978-01-01

    A shock absorber is described for use in a hostile environment at the end of a blind passage for absorbing impact loads. The shock absorber includes at least one element which occupies the passage and which is comprised of a porous brittle material which is substantially non-degradable in the hostile environment. A void volume is provided in the element to enable the element to absorb a predetermined level of energy upon being crushed due to impact loading

  4. Comparison of iron and tungsten absorber structures for an analog hadron calorimeter

    International Nuclear Information System (INIS)

    Guenter, Clemens

    2015-05-01

    Future electron-positron-collider experiments will require unprecedented jet-energy resolution to complete their physics programs. This can only be achieved with novel approaches to calorimetry. One of these novel approaches is the Particle Flow Algorithm, which uses the best suited sub-detector to measure the energy of the particles produced by the electronpositron collision. The CALICE Collaboration evaluates different read-out technologies for Particle Flow Calorimeters. This thesis describes the comparison of two different absorber materials, iron and tungsten, for the CALICE Analog Hadron Calorimeter. It is described how test-beam data, that have been recorded in the range from 2 GeV to 10 GeV with the Analog Hadron Calorimeter are calibrated, and how samples are selected containing showers from just one particle type. The data are then compared to simulations, and the remaining disagreement between data and simulation is discussed. The validated simulations are then used to decompose the showers into different fractions. These fractions are compared for the two absorber materials to understand the impact of the absorber material choice on the calorimeter performance.

  5. Boundary values as Hamiltonian variables. II. Graded structures

    International Nuclear Information System (INIS)

    Soloviev, Vladimir O.

    2002-01-01

    It is shown that the new formula for the field theory Poisson brackets arises naturally in the proposed extension of the formal variational calculus incorporating divergences. The linear spaces of local functionals, evolutionary vector fields, functional forms, multi-vectors and differential operators become graded with respect to divergences. The bilinear operations, such as the action of vector fields onto functionals, the commutator of vector fields, the interior product of forms and vectors and the Schouten-Nijenhuis bracket are compatible with the grading. A definition of the adjoint graded operator is proposed and antisymmetric operators are constructed with the help of boundary terms. The fulfilment of the Jacobi identity for the new Poisson brackets is shown to be equivalent to vanishing of the Schouten-Nijenhuis bracket of the Poisson bivector with itself

  6. Absorbed impact energy and mode of fracture: A statistical description of the micro-structural dispersion

    Energy Technology Data Exchange (ETDEWEB)

    Pontikis, V., E-mail: Vassilis.Pontikis@cea.f [Commissariat a l' Energie Atomique, IRAMIS, Laboratoire des Solides Irradies, CNRS UMR 7642, Ecole Polytechnique, 91191 Gif sur Yvette Cedex (France); Gorse, D. [Commissariat a l' Energie Atomique, IRAMIS, Laboratoire des Solides Irradies, CNRS UMR 7642, Ecole Polytechnique, 91191 Gif sur Yvette Cedex (France)

    2009-10-01

    A statistical model is proposed to account for the influence of the dispersion of the microstructure on the ductile-to-brittle transition in body centered cubic (bcc) metals and their alloys. In this model, the dispersion of the microstructure is expressed via a normal distribution of transition temperatures whereas a simple relation exists between the values of absorbed, lower and upper shelf energies, the ductile area fraction and the distribution parameters. It is shown that via an appropriate renormalization of energies and temperatures, experimental data for different materials and ageing conditions align all together on a master curve, guaranteeing thereby the effectiveness of the proposed statistical description.

  7. Absorbed impact energy and mode of fracture: A statistical description of the micro-structural dispersion

    International Nuclear Information System (INIS)

    Pontikis, V.; Gorse, D.

    2009-01-01

    A statistical model is proposed to account for the influence of the dispersion of the microstructure on the ductile-to-brittle transition in body centered cubic (bcc) metals and their alloys. In this model, the dispersion of the microstructure is expressed via a normal distribution of transition temperatures whereas a simple relation exists between the values of absorbed, lower and upper shelf energies, the ductile area fraction and the distribution parameters. It is shown that via an appropriate renormalization of energies and temperatures, experimental data for different materials and ageing conditions align all together on a master curve, guaranteeing thereby the effectiveness of the proposed statistical description.

  8. Structure with improved self-imaging in its graded-index multimode interference region

    International Nuclear Information System (INIS)

    Yin Rui; Jiang Xiaoqing; Yang Jianyi; Wang Minghua

    2002-01-01

    Propagation constant errors (PCEs) of guided modes in regions of multimode interference in optical networks were analyzed. Results show that a graded-index waveguide can effectively decrease the PCEs. An example based on an exponential function is presented. Numerical results show that addition of a graded-index waveguide greatly improves device performance in this structure

  9. Active pipe-embedded structures in buildings for utilizing low-grade energy sources: A review

    International Nuclear Information System (INIS)

    Xu, Xinhua; Wang, Jinbo; Wang, Shengwei; Xiao, Fu

    2010-01-01

    Low-grade energy sources such as geothermal energy, favorable ambient air and industrial waste heat etc. exist widely. Sufficient utilization of these low-grade energy sources may reduce our daily dependence on high-grade energy sources such as electricity resulting in reduced emission of green house gas for environmental conservation. Active pipe-embedded structure as floor/ceiling usually with water as the medium to carry heat or coolth may utilize these low-grade energy sources for providing space air-conditioning. Compact arrangement of pipes in the structure may significantly enlarge heat transfer surface between the slab mass and water in the pipe allowing substantial heat flows even for relatively small temperature differences. Application of the heat or coolth storage capacity of this structure for preheating or pre-cooling is also one among the advantages of this structure for shifting load and exploiting the nighttime cheap electricity tariff in some regions. This paper presents the technology of the active pipe-embedded structure for utilizing widely existing low-grade energy sources following by a comprehensive review on the heat transfer calculation models of this structure and its practical applications in real building systems for space air-conditioning. This review shows that more works on the active structure, especially simple and transient models for dynamic and accurate performance prediction and easy integration with existing building energy simulation packages, are worthwhile for further promoting the practical application wherever the low-grade energy sources are favorable. (author)

  10. Absorbant materials

    International Nuclear Information System (INIS)

    Quetier, Monique.

    1978-11-01

    Absorbants play a very important part in the nuclear industry. They serve for the control, shut-down and neutron shielding of reactors and increase the capacity of spent fuel storage pools and of special transport containers. This paper surveys the usual absorbant materials, means of obtainment, their essential characteristics relating to their use and their behaviour under neutron irradiation [fr

  11. Graded territories: Towards the design, specification and simulation of materially graded bending active structures

    DEFF Research Database (Denmark)

    Nicholas, Paul; Tamke, Martin; Ramsgaard Thomsen, Mette

    2012-01-01

    these structures, the property of bending is activated and varied through bespoke material means so as to match a desired form. Within the architectural design process, formal control depends upon design approaches for material specification and simulation that consider behavior at the level of the material...... element as well as the structure. We describe an evolving approach to material specification and simulation, and highlight the digital and material considerations that frame the process.......The ability to make materials with bespoke behavior affords new perspectives on incorporating material properties within the design process not available through natural materials. This paper reports the design and assembly of two bending-active, fibre-reinforced composite structures. Within...

  12. Acoustic contributions of a sound absorbing blanket placed in a double panel structure: Absorption Versus Transmission

    OpenAIRE

    Doutres , Olivier; Atalla , Noureddine

    2010-01-01

    International audience; The objective of this paper is to propose a simple tool to estimate the absorption vs. transmission loss contributions of a multilayered blanket unbounded in a double panel structure and thus guide its optimization. The normal incidence airborne sound transmission loss of the double panel structure, without structure-borne connections, is written in terms of three main contributions; (i) sound transmission loss of the panels, (ii) sound transmission loss of the blanket...

  13. Functionally Graded Materials using Plasma Spray with Nano Structured Ceramic

    International Nuclear Information System (INIS)

    Sioh, E L; Tok, A I Y

    2013-01-01

    In this paper, nano structured FGM was fabricated using DC plasma spray technique. Nano structured and micro structured powder were used as the feeding powder with steel substrate. The spray parameters was optimized and characterisation of nano-ceramic FGM and micro-ceramic FGM were done using bending test and micro-hardness test. Experimental results have shown that the nano-structured FGM exhibit 20% improvement flexure strength and 10% in hardness. A comparison was made between sintered micro ceramic tile and nano ceramic FGM using simple drop test method.

  14. Cohesion strength and atomic structure of W-Cu graded interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Liang, C.P.; Fan, J.L.; Gong, H.R., E-mail: gonghr@csu.edu.cn

    2017-04-15

    W-Cu graded interface is a solution to big differences of properties between W and Cu, while the number and composition of graded layers in the literature are quite different. The present first principles calculation reveals that W-rich graded interfaces possess higher strength and lower interface energy than Cu-rich counterparts. It shows that the differences of thermal expansion and Young’s modulus between overlayer and substrate are decisive factors in the design of Cu-rich and W-rich graded interfaces, respectively. A graded structure of W{sub 8}Cu{sub 1}/W{sub 7}Cu{sub 2}/W{sub 6}Cu{sub 3}/Cu{sub 6}W{sub 3}/Cu{sub 8}W{sub 1} is therefore suggested theoretically.

  15. Predicting the biological effects of mobile phone radiation absorbed energy linked to the MRI-obtained structure.

    Science.gov (United States)

    Krstić, Dejan; Zigar, Darko; Petković, Dejan; Sokolović, Dušan; Dinđić, Boris; Cvetković, Nenad; Jovanović, Jovica; Dinđić, Nataša

    2013-01-01

    The nature of an electromagnetic field is not the same outside and inside a biological subject. Numerical bioelectromagnetic simulation methods for penetrating electromagnetic fields facilitate the calculation of field components in biological entities. Calculating energy absorbed from known sources, such as mobile phones when placed near the head, is a prerequisite for studying the biological influence of an electromagnetic field. Such research requires approximate anatomical models which are used to calculate the field components and absorbed energy. In order to explore the biological effects in organs and tissues, it is necessary to establish a relationship between an analogous anatomical model and the real structure. We propose a new approach in exploring biological effects through combining two different techniques: 1) numerical electromagnetic simulation, which is used to calculate the field components in a similar anatomical model and 2) Magnetic Resonance Imaging (MRI), which is used to accurately locate sites with increased absorption. By overlapping images obtained by both methods, we can precisely locate the spots with maximum absorption effects. This way, we can detect the site where the most pronounced biological effects are to be expected. This novel approach successfully overcomes the standard limitations of working with analogous anatomical models.

  16. Performance assessment for an above grade disposal structure

    International Nuclear Information System (INIS)

    Blickwedehl, R.R.

    1987-01-01

    The low-level waste generated in conjunction with solidification of high-level waste at the West Valley Demonstration Project will be disposed of in an above grade earthen mound. This method of disposal was selected in consideration of the site geology and waste characteristics. The earth mound is designed to permanently isolate the waste from the environment by means of redundant clay caps over the waste cell. However, it is possible that engineered barriers might fail under contingency conditions. A pathway analysis was performed to analyze the dose to man which might result under these conditions. A finite element code was used to model seepage through the clay caps and the waste cell. The water flux and velocity in the waste cell were used to estimate the leaching by diffusion theory. Leachate from this source discharges to the environment and flow overland to surface waters which drain the disposal site. Some of the radionuclides in the leachate are sorbed onto the surface soils during the overland flow. The most significant exposure was to a hypothetical individual who illegally resided on the site and planted a vegetable garden. Most of this potential dose was from inhalation of contaminated surface soil which was resuspended when the soil was tilled. The maximum dose received by the on-site resident was estimated to be 3 mrem/year, a fraction of background. The predicted dose to an off-site resident was two orders of magnitude less. 12 references, 7 figures, 1 table

  17. Acoustic contributions of a sound absorbing blanket placed in a double panel structure: absorption versus transmission.

    Science.gov (United States)

    Doutres, Olivier; Atalla, Noureddine

    2010-08-01

    The objective of this paper is to propose a simple tool to estimate the absorption vs. transmission loss contributions of a multilayered blanket unbounded in a double panel structure and thus guide its optimization. The normal incidence airborne sound transmission loss of the double panel structure, without structure-borne connections, is written in terms of three main contributions; (i) sound transmission loss of the panels, (ii) sound transmission loss of the blanket and (iii) sound absorption due to multiple reflections inside the cavity. The method is applied to four different blankets frequently used in automotive and aeronautic applications: a non-symmetric multilayer made of a screen in sandwich between two porous layers and three symmetric porous layers having different pore geometries. It is shown that the absorption behavior of the blanket controls the acoustic behavior of the treatment at low and medium frequencies and its transmission loss at high frequencies. Acoustic treatment having poor sound absorption behavior can affect the performance of the double panel structure.

  18. Structure and electronic properties of grain boundaries in earth-abundant photovoltaic absorber Cu2ZnSnSe4.

    Science.gov (United States)

    Li, Junwen; Mitzi, David B; Shenoy, Vivek B

    2011-11-22

    We have studied the atomic and electronic structure of Cu(2)ZnSnSe(4) and CuInSe(2) grain boundaries using first-principles calculations. We find that the constituent atoms at the grain boundary in Cu(2)ZnSnSe(4) create localized defect states that promote the recombination of photon-excited electron and hole carriers. In distinct contrast, significantly lower density of defect states is found at the grain boundaries in CuInSe(2), which is consistent with the experimental observation that CuInSe(2) solar cells exhibit high conversion efficiency without the need for deliberate passivation. Our investigations suggest that it is essential to effectively remove these defect states in order to improve the conversion efficiency of solar cells with Cu(2)ZnSnSe(4) as photovoltaic absorber materials. © 2011 American Chemical Society

  19. Absorbability, Mechanism and Structure-Property Relationship of Three Phenolic Acids from the Flowers of Trollius chinensis

    Directory of Open Access Journals (Sweden)

    Xiu-Wen Wu

    2014-11-01

    Full Text Available The absorption properties, mechanism of action, and structure-property relationship of three phenolic acids isolated from the flowers of Trollius chinensis Bunge, namely, proglobeflowery acid (PA, globeflowery acid (GA and trolloside (TS, were investigated using the human Caco-2 cell monolayer model. The results showed that these three phenolic acids were transported across the Caco-2 cell monolayer in a time and concentration dependent manner at the Papp level of 10−5 cm/s, and their extent of absorption correlated with their polarity and molecular weight. In conclusion, all three of these compounds were easily absorbed through passive diffusion, which implied their high bioavailability and significant contribution to the effectiveness of T. chinensis.

  20. Structure Building Predicts Grades in College Psychology and Biology

    Science.gov (United States)

    Arnold, Kathleen M.; Daniel, David B.; Jensen, Jamie L.; McDaniel, Mark A.; Marsh, Elizabeth J.

    2016-01-01

    Knowing what skills underlie college success can allow students, teachers, and universities to identify and to help at-risk students. One skill that may underlie success across a variety of subject areas is structure building, the ability to create mental representations of narratives (Gernsbacher, Varner, & Faust, 1990). We tested if…

  1. Reconstructing the energy band electronic structure of pulsed laser deposited CZTS thin films intended for solar cell absorber applications

    Science.gov (United States)

    Pandiyan, Rajesh; Oulad Elhmaidi, Zakaria; Sekkat, Zouheir; Abd-lefdil, Mohammed; El Khakani, My Ali

    2017-02-01

    We report here on the use of pulsed KrF-laser deposition (PLD) technique for the growth of high-quality Cu2ZnSnS4 (CZTS) thin films onto Si, and glass substrates without resorting to any post sulfurization process. The PLD-CZTS films were deposited at room temperature (RT) and then subjected to post annealing at different temperatures ranging from 200 to 500 °C in Argon atmosphere. The X-ray diffraction and Raman spectroscopy confirmed that the PLD films crystallize in the characteristic kesterite CZTS structure regardless of their annealing temperature (Ta), but their crystallinity is much improved for Ta ≥ 400 °C. The PLD-CZTS films were found to exhibit a relatively dense morphology with a surface roughness (RMS) that increases with Ta (from ∼14 nm at RT to 70 nm at Ta = 500 °C with a value around 40 nm for Ta = 300-400 °C). The optical bandgap of the PLD-CZTS films, was derived from UV-vis transmission spectra analysis, and found to decrease from 1.73 eV for non-annealed films to ∼1.58 eV for those annealed at Ta = 300 °C. These band gap values are very close to the optimum value needed for an ideal solar cell absorber. In order to achieve a complete reconstruction of the one-dimensional energy band structure of these PLD-CZTS absorbers, we have combined both XPS and UPS spectroscopies to determine their chemical bondings, the position of their valence band maximum (relative to Fermi level), and their work function values. This enabled us to sketch out, as accurately as possible, the band alignment of the heterojunction interface formed between CZTS and both CdS and ZnS buffer layer materials.

  2. Classroom Organizational Structure in Fifth Grade Math Classrooms and the Effect on Standardized Test Scores

    Science.gov (United States)

    Lane, Dallas Marie

    2017-01-01

    The purpose of this study was to determine if there is a relationship between the classroom organizational structure and MCT2 test scores of fifth-grade math students. The researcher gained insight regarding which structure teachers believe is most beneficial to them and students, and whether or not their belief of classroom organizational…

  3. Surface extended x-ray absorption fine structure of low-Z absorbates using fluorescence detection

    International Nuclear Information System (INIS)

    Stoehr, J.; Kollin, E.B.; Fischer, D.A.; Hastings, J.B.; Zaera, F.; Sette, F.

    1985-05-01

    Comparison of x-ray fluorescence yield (FY) and electron yield surface extended x-ray absorption fine structure spectra above the S K-edge for c(2 x 2) S on Ni(100) reveals an order of magnitude higher sensitivity of the FY technique. Using FY detection, thiophene (C 4 H 4 S) chemisorption on Ni(100) is studied with S coverages down to 0.08 monolayer. The molecule dissociates at temperatures as low as 100K by interaction with fourfold hollow Ni sites. Blocking of these sites by oxygen leaves the molecule intact

  4. A statistical method for predicting sound absorbing property of porous metal materials by using quartet structure generation set

    International Nuclear Information System (INIS)

    Guan, Dong; Wu, Jiu Hui; Jing, Li

    2015-01-01

    Highlights: • A random internal morphology and structure generation-growth method, termed as the quartet structure generation set (QSGS), has been utilized based on the stochastic cluster growth theory for numerical generating the various microstructures of porous metal materials. • Effects of different parameters such as thickness and porosity on sound absorption performance of the generated structures are studied by the present method, and the obtained results are validated by an empirical model as well. • This method could be utilized to guide the design and fabrication of the sound-absorption porous metal materials. - Abstract: In this paper, a statistical method for predicting sound absorption properties of porous metal materials is presented. To reflect the stochastic distribution characteristics of the porous metal materials, a random internal morphology and structure generation-growth method, termed as the quartet structure generation set (QSGS), has been utilized based on the stochastic cluster growth theory for numerical generating the various microstructures of porous metal materials. Then by using the transfer-function approach along with the QSGS tool, we investigate the sound absorbing performance of porous metal materials with complex stochastic geometries. The statistical method has been validated by the good agreement among the numerical results for metal rubber from this method and a previous empirical model and the corresponding experimental data. Furthermore, the effects of different parameters such as thickness and porosity on sound absorption performance of the generated structures are studied by the present method, and the obtained results are validated by an empirical model as well. Therefore, the present method is a reliable and robust method for predicting the sound absorption performance of porous metal materials, and could be utilized to guide the design and fabrication of the sound-absorption porous metal materials

  5. Sound Absorbers

    Science.gov (United States)

    Fuchs, H. V.; Möser, M.

    Sound absorption indicates the transformation of sound energy into heat. It is, for instance, employed to design the acoustics in rooms. The noise emitted by machinery and plants shall be reduced before arriving at a workplace; auditoria such as lecture rooms or concert halls require a certain reverberation time. Such design goals are realised by installing absorbing components at the walls with well-defined absorption characteristics, which are adjusted for corresponding demands. Sound absorbers also play an important role in acoustic capsules, ducts and screens to avoid sound immission from noise intensive environments into the neighbourhood.

  6. Reconstructing the energy band electronic structure of pulsed laser deposited CZTS thin films intended for solar cell absorber applications

    Energy Technology Data Exchange (ETDEWEB)

    Pandiyan, Rajesh [Institut National de la Recherche Scientifique, Centre-Énergie, Matériaux et Télécommunications, 1650 Blvd. Lionel–Boulet, C.P. 1020, Varennes, QC J3X-1S2 (Canada); Oulad Elhmaidi, Zakaria [Institut National de la Recherche Scientifique, Centre-Énergie, Matériaux et Télécommunications, 1650 Blvd. Lionel–Boulet, C.P. 1020, Varennes, QC J3X-1S2 (Canada); University of Mohammed V, Faculty of Sciences, Materials Physics Laboratory, B.P. 1014 Rabat (Morocco); Sekkat, Zouheir [Optics & Photonics Center, Moroccan Foundation for Advanced Science, Innovation and Research, Rabat (Morocco); Abd-lefdil, Mohammed [University of Mohammed V, Faculty of Sciences, Materials Physics Laboratory, B.P. 1014 Rabat (Morocco); El Khakani, My Ali, E-mail: elkhakani@emt.inrs.ca [Institut National de la Recherche Scientifique, Centre-Énergie, Matériaux et Télécommunications, 1650 Blvd. Lionel–Boulet, C.P. 1020, Varennes, QC J3X-1S2 (Canada)

    2017-02-28

    Highlights: • High quality CZTS thin films grown by means of PLD technique without resorting to any post sulfurization process. • Effect of thermal annealing treatments (in the 200–500 °C range) on the structural, morphological and optoelectronic properties of PLD-CZTS films. • Experimental determination of key optoelectronic parameters (i.e.; E{sub g}, VBM, ϕ, I{sub p}, and χ) enabling the reconstruction of energy band electronic structure of the PLD-CZTS films. • Investigation on the energy band alignments of the heterojunction interface formed between CZTS and both CdS and ZnS buffer layer materials. - Abstract: We report here on the use of pulsed KrF-laser deposition (PLD) technique for the growth of high-quality Cu{sub 2}ZnSnS{sub 4} (CZTS) thin films onto Si, and glass substrates without resorting to any post sulfurization process. The PLD-CZTS films were deposited at room temperature (RT) and then subjected to post annealing at different temperatures ranging from 200 to 500 °C in Argon atmosphere. The X-ray diffraction and Raman spectroscopy confirmed that the PLD films crystallize in the characteristic kesterite CZTS structure regardless of their annealing temperature (T{sub a}), but their crystallinity is much improved for T{sub a} ≥ 400 °C. The PLD-CZTS films were found to exhibit a relatively dense morphology with a surface roughness (RMS) that increases with T{sub a} (from ∼14 nm at RT to 70 nm at T{sub a} = 500 °C with a value around 40 nm for T{sub a} = 300–400 °C). The optical bandgap of the PLD-CZTS films, was derived from UV–vis transmission spectra analysis, and found to decrease from 1.73 eV for non-annealed films to ∼1.58 eV for those annealed at T{sub a} = 300 °C. These band gap values are very close to the optimum value needed for an ideal solar cell absorber. In order to achieve a complete reconstruction of the one-dimensional energy band structure of these PLD-CZTS absorbers, we have combined both XPS and UPS

  7. Shock absorber

    International Nuclear Information System (INIS)

    Nemeth, J.D.

    1981-01-01

    A shock absorber for the support of piping and components in a nuclear power plant is described. It combines a high degree of stiffness under sudden shocks, e.g. seismic disturbances, with the ability to allow for thermal expansion without resistance when so required. (JIW)

  8. Cellular Energy Absorbing TRIP-Steel/Mg-PSZ Composite: Honeycomb Structures Fabricated by a New Extrusion Powder Technology

    Directory of Open Access Journals (Sweden)

    Ulrich Martin

    2010-01-01

    Full Text Available Lightweight linear cellular composite materials on basis of austenite stainless TRIP- (TRansformation Induced Plasticity- steel as matrix with reinforcements of MgO partially stabilized zirconia (Mg-PSZ are described. Two-dimensional cellular materials for structural applications are conventionally produced by sheet expansion or corrugation processes. The presented composites are fabricated by a modified ceramic extrusion powder technology. Characterization of the microstructure in as-received and deformed conditions was carried out by optical and scanning electron microscopy. Magnetic balance measurements and electron backscatter diffraction (EBSD were used to identify the deformation-induced martensite evolution in the cell wall material. The honeycomb composite samples exhibit an increased strain hardening up to a certain engineering compressive strain and an extraordinary high specific energy absorption per unit mass and unit volume, respectively. Based on improved property-to-weight ratio such linear cellular structures will be of interest as crash absorbers or stiffened core materials for aerospace, railway, or automotive applications.

  9. Thermo-Electro-Mechanical Analysis of a Curved Functionally Graded Piezoelectric Actuator with Sandwich Structure

    Directory of Open Access Journals (Sweden)

    Liying Jiang

    2011-12-01

    Full Text Available In this work, the problem of a curved functionally graded piezoelectric (FGP actuator with sandwich structure under electrical and thermal loads is investigated. The middle layer in the sandwich structure is functionally graded with the piezoelectric coefficient g31 varying continuously along the radial direction of the curved actuator. Based on the theory of linear piezoelectricity, analytical solutions are obtained by using Airy stress function to examine the effects of material gradient and heat conduction on the performance of the curved actuator. It is found that the material gradient and thermal load have significant influence on the electroelastic fields and the mechanical response of the curved FGP actuator. Without the sacrifice of actuation deflection, smaller internal stresses are generated by using the sandwich actuator with functionally graded piezoelectric layer instead of the conventional bimorph actuator. This work is very helpful for the design and application of curved piezoelectric actuators under thermal environment.

  10. Thermo-Electro-Mechanical Analysis of a Curved Functionally Graded Piezoelectric Actuator with Sandwich Structure.

    Science.gov (United States)

    Yan, Zhi; Zaman, Mostafa; Jiang, Liying

    2011-12-12

    In this work, the problem of a curved functionally graded piezoelectric (FGP) actuator with sandwich structure under electrical and thermal loads is investigated. The middle layer in the sandwich structure is functionally graded with the piezoelectric coefficient g 31 varying continuously along the radial direction of the curved actuator. Based on the theory of linear piezoelectricity, analytical solutions are obtained by using Airy stress function to examine the effects of material gradient and heat conduction on the performance of the curved actuator. It is found that the material gradient and thermal load have significant influence on the electroelastic fields and the mechanical response of the curved FGP actuator. Without the sacrifice of actuation deflection, smaller internal stresses are generated by using the sandwich actuator with functionally graded piezoelectric layer instead of the conventional bimorph actuator. This work is very helpful for the design and application of curved piezoelectric actuators under thermal environment.

  11. Analysis, manufacture and characterization of Ni/Cu functionally graded structures

    International Nuclear Information System (INIS)

    Rubio, Wilfredo Montealegre; Paulino, Glaucio H.; Silva, Emilio Carlos Nelli

    2012-01-01

    Highlights: ► Functionally graded structures (FGSs) of nickel and copper can be manufactured. ► The hardness curve of FGS can be used for approximating the gradation function of elastic properties. ► The graded finite element approaches with great accuracy the FGS resonance frequencies obtained experimentally. -- Abstract: In this work, an experimental and numerical analysis and characterization of functionally graded structures (FGSs) is developed. Nickel (Ni) and copper (Cu) materials are used as basic materials in the numerical modeling and experimental characterization. For modeling, a MATLAB finite element code is developed, which allows simulation of harmonic and modal analysis considering the graded finite element formulation. For experimental characterization, Ni–Cu FGSs are manufactured by using spark plasma sintering technique. Hardness and Young’s modulus are found by using microindentation and ultrasonic measurements, respectively. The effective gradation of Ni/Cu FGS is addressed by means of optical microscopy, energy dispersive spectrometry, scanning electron microscopy and hardness testing. For the purpose of comparing modeling and experimental results, the hardness curve, along the gradation direction, is used for identifying the gradation profile; accordingly, the experimental hardness curve is used for approximating the Young’s modulus variation and the graded finite element modeling is used for verification. For the first two resonance frequency values, a difference smaller than 1% between simulated and experimental results is obtained.

  12. The Factor Structure of Coordination Abilities Development in 5th-7th Grade Boys

    Directory of Open Access Journals (Sweden)

    В. В. Приходько

    2017-12-01

    Full Text Available The objective is to determine the structure of coordination abilities development in 5th-7th grade boys. Materials and methods. The participants in the study were boys of the 5th grade (n=21, 6th grade (n=20, and 7th grade (n=19. The paper used analysis and generalization of the scientific and methodological literature data, general scientific methods of theoretical level, namely: analogy, analysis, synthesis, abstracting, induction, as well as general scientific methods of empirical level: observation, testing, experiment. To evaluate of the motor preparedness, the results of motor tests, height and body weight were recorded. The materials of the study were processed in the statistical analysis program IBM SPSS 20. Factor analysis was carried out using a model of the principal components with the rotation method: Variamax with Kaiser normalization. Results. Analysis of the similarities shows that the most informative in the structure of the 5th grade boys’ motor preparedness are Test 9 “Static Equilibrium Evaluation by E. Ya. Bondarevsky’s Method” (,999, Test 2 “Standing Long Jump (cm” (,998, Test 10 “Dynamic Equilibrium Evaluation by Bess Method” (,916; for the 6th grade boys such are Test 9 “Static Equilibrium Evaluation by E. Ya. Bondarevsky’s Method” (1.0, Test 2 “Standing Long Jump (cm” (,999, Test 5 “Sit-Up for 30 sec.” (,968, Test 10 “Dynamic Equilibrium Evaluation by Bess Method” (,918; for the 7th grade boys such are Test 2 “Standing Long Jump (cm” (,994, Test 9 “Static Equilibrium Evaluation by E. Ya. Bondarevsky’s Method” (,987, Test 10 “Dynamic Equilibrium Evaluation by Bess Method” (,945. Conclusions. The most informative in the structure of 5th-7th grade boys’ coordination abilities is vestibular tolerance. For pedagogical control of 5th-7th grade boys’ motor preparedness the following can be recommended: Test 2 “Standing Long Jump (cm”, Test 9 “Static Equilibrium

  13. Ten-Structure as Strategy of Addition 1-20 by Involving Spatial Structuring Ability for First Grade Students

    Science.gov (United States)

    Salmah, Ummy; Putri, Ratu Ilma Indra; Somakim

    2015-01-01

    The aim of this study is to design learning activities that can support students to develop strategies for the addition of number 1 to 20 in the first grade by involving students' spatial structuring ability. This study was conducted in Indonesia by involving 27 students. In this paper, one of three activities is discussed namely ten-box activity.…

  14. Vibration mitigation for in-wheel switched reluctance motor driven electric vehicle with dynamic vibration absorbing structures

    Science.gov (United States)

    Qin, Yechen; He, Chenchen; Shao, Xinxin; Du, Haiping; Xiang, Changle; Dong, Mingming

    2018-04-01

    This paper presents a new approach for vibration mitigation based on a dynamic vibration absorbing structure (DVAS) for electric vehicles (EVs) that use in-wheel switched reluctance motors (SRMs). The proposed approach aims to alleviate the negative effects of vibration caused by the unbalanced electromagnetic force (UMEF) that arises from road excitations. The analytical model of SRMs is first formulated using Fourier series, and then a model of the coupled longitudinal-vertical dynamics is developed taking into consideration the external excitations consisting of the aerodynamic drag force and road unevenness. In addition, numerical simulations for a conventional SRM-suspension system and two novel DVASs are carried out for varying road levels specified by ISO standards and vehicle velocities. The results of the comparison reveal that a 35% improvement in ride comfort, 30% improvement of road handling, and 68% improvement in air gap between rotor and stator can be achieved by adopting the novel DVAS compared to the conventional SRM-suspension system. Finally, multi-body simulation (MBS) is performed using LMS Motion to validate the feasibility of the proposed DVAS. Analysis of the results shows that the proposed method can augment the effective application of SRMs in EVs.

  15. Fine structure of the absorbed dose rate monitored in Zagreb, Croatia, in the period 1985-2011.

    Science.gov (United States)

    Babić, D; Senčar, J; Petrinec, B; Marović, G; Bituh, T; Skoko, B

    2013-04-01

    We report on the fine structure of the absorbed dose rate D which was measured and recorded on a daily basis at the Institute for Medical Research and Occupational Health in Zagreb, Croatia, throughout the period 1985-2011. After the Chernobyl accident, D increased steeply by a factor of 3.5, but this is the only prominent feature in the D versus time (t) curve. In the absence of accidental conditions, the D(t) is flat and amounts to 30-35 pGy/s. Despite the apparent plainness of D(t), its Fourier transform reveals several periodic modulations hidden in the noise. Some of the corresponding periods (6 and 12 months) can be related to seasonal atmospheric changes but this is not the case with the other periods identified (9.3, 13.7, 15.7, 20, 31, and 39 months). These are found to agree well with literature data on periodicities in solar activity, which implies that they are most probably linked to variations in the atmospheric production of (7)Be by cosmic rays. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. Tuning Structure and Properties of Graded Triblock Terpolymer-Based Mesoporous and Hybrid Films

    KAUST Repository

    Phillip, William A.

    2011-07-13

    Despite considerable efforts toward fabricating ordered, water-permeable, mesoporous films from block copolymers, fine control over pore dimensions, structural characteristics, and mechanical behavior of graded structures remains a major challenge. To this end, we describe the fabrication and performance characteristics of graded mesoporous and hybrid films derived from the newly synthesized triblock terpolymer, poly(isoprene-b-styrene-b-4-vinylpyridine). A unique morphology, unachievable in diblock copolymer systems, with enhanced mechanical integrity is evidenced. The film structure comprises a thin selective layer containing vertically aligned and nearly monodisperse mesopores at a density of more than 1014 per m2 above a graded macroporous layer. Hybridization via homopolymer blending enables tuning of pore size within the range of 16 to 30 nm. Solvent flow and solute separation experiments demonstrate that the terpolymer films have permeabilities comparable to commercial membranes, are stimuli-responsive, and contain pores with a nearly monodisperse diameter. These results suggest that moving to multiblock polymers and their hybrids may open new paths to produce high-performance graded membranes for filtration, separations, nanofluidics, catalysis, and drug delivery. © 2011 American Chemical Society.

  17. Structural and optical properties of Cu2ZnSnS4 thin film absorbers from ZnS and Cu3SnS4 nanoparticle precursors

    International Nuclear Information System (INIS)

    Lin, Xianzhong; Kavalakkatt, Jaison; Kornhuber, Kai; Levcenko, Sergiu; Lux-Steiner, Martha Ch.; Ennaoui, Ahmed

    2013-01-01

    Cu 2 ZnSnS 4 (CZTS) has been considered as an alternative absorber layer to Cu(In,Ga)Se 2 due to its earth abundant and environmentally friendly constituents, optimal direct band gap of 1.4–1.6 eV and high absorption coefficient in the visible range. In this work, we propose a solution-based chemical route for the preparation of CZTS thin film absorbers by spin coating of the precursor inks composed of Cu 3 SnS 4 and ZnS NPs and annealing in Ar/H 2 S atmosphere. X-ray diffraction and Raman spectroscopy were used to characterize the structural properties. The chemical composition was determined by energy dispersive X-ray spectroscopy. Optical properties of the CZTS thin film absorbers were studied by transmission, reflection and photoluminescence spectroscopy

  18. Drop Weight Device Fabrication and Tests for a Dynamic Material Property of Shock-Absorbing Material and Structure in Transportation Package

    International Nuclear Information System (INIS)

    Choi, Woo Seok; Jeon, Jea Eon; Han, Sang Hyeok; Lee, Sang Hoon; Seo, Ki Seok

    2009-01-01

    A radioactive material transportation package consists of canister and impact limiters. IAEA Safety Standard Series No. TS-R-1 recommends a drop test to evaluate the structural integrity of a transportation package under a hypothetical accident condition. The free drop test of a transportation package from 9 m height simulates one of accident conditions. The transportation package has a potential energy corresponding to 9 m drop height, and this energy changes to a kinetic energy when it impacts on the target. The energy is absorbed by a deformation of shock-absorbing material so that the minimum energy is transferred to canister. Accordingly, the shock-absorbing material is a very important part in transportation package design. Since the data for shock-absorbing material characteristics is acquired by a static test in general, it is quite different to that of dynamic characteristics. And the dynamic characteristics data is hardly found in literature. In this study, a drop weight facility was designed and fabricated which produces an impact speed like that of free drop of 9 m height. Several materials considered for an impact limiter and impact limiter structures were tested by a drop weight facility to acquire a dynamic material characteristics data

  19. Drop Weight Device Fabrication and Tests for a Dynamic Material Property of Shock-Absorbing Material and Structure in Transportation Package

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Woo Seok; Jeon, Jea Eon; Han, Sang Hyeok; Lee, Sang Hoon; Seo, Ki Seok [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2009-05-15

    A radioactive material transportation package consists of canister and impact limiters. IAEA Safety Standard Series No. TS-R-1 recommends a drop test to evaluate the structural integrity of a transportation package under a hypothetical accident condition. The free drop test of a transportation package from 9 m height simulates one of accident conditions. The transportation package has a potential energy corresponding to 9 m drop height, and this energy changes to a kinetic energy when it impacts on the target. The energy is absorbed by a deformation of shock-absorbing material so that the minimum energy is transferred to canister. Accordingly, the shock-absorbing material is a very important part in transportation package design. Since the data for shock-absorbing material characteristics is acquired by a static test in general, it is quite different to that of dynamic characteristics. And the dynamic characteristics data is hardly found in literature. In this study, a drop weight facility was designed and fabricated which produces an impact speed like that of free drop of 9 m height. Several materials considered for an impact limiter and impact limiter structures were tested by a drop weight facility to acquire a dynamic material characteristics data.

  20. Exploring the determinants of the graded structure of vocal emotion expressions.

    Science.gov (United States)

    Laukka, Petri; Audibert, Nicolas; Aubergé, Véronique

    2012-01-01

    We examined what determines the typicality, or graded structure, of vocal emotion expressions. Separate groups of judges rated acted and spontaneous expressions of anger, fear, and joy with regard to their typicality and three main determinants of the graded structure of categories: category members' similarity to the central tendency of their category (CT); category members' frequency of instantiation, i.e., how often they are encountered as category members (FI); and category members' similarity to ideals associated with the goals served by its category, i.e., suitability to express particular emotions. Partial correlations and multiple regression analysis revealed that similarity to ideals, rather than CT or FI, explained most variance in judged typicality. Results thus suggest that vocal emotion expressions constitute ideal-based goal-derived categories, rather than taxonomic categories based on CT and FI. This could explain how prototypical expressions can be acoustically distinct and highly recognisable but occur relatively rarely in everyday speech.

  1. The Grading Entropy-based Criteria for Structural Stability of Granular Materials and Filters

    Directory of Open Access Journals (Sweden)

    Janos Lőrincz

    2015-05-01

    Full Text Available This paper deals with three grading entropy-based rules that describe different soil structure stability phenomena: an internal stability rule, a filtering rule and a segregation rule. These rules are elaborated on the basis of a large amount of laboratory testing and from existing knowledge in the field. Use is made of the theory of grading entropy to derive parameters which incorporate all of the information of the grading curve into a pair of entropy-based parameters that allow soils with common behaviours to be grouped into domains on an entropy diagram. Applications of the derived entropy-based rules are presented by examining the reason of a dam failure, by testing against the existing filter rules from the literature, and by giving some examples for the design of non-segregating grading curves (discrete particle size distributions by dry weight. A physical basis for the internal stability rule is established, wherein the higher values of base entropy required for granular stability are shown to reflect the closeness between the mean and maximum grain diameters, which explains how there are sufficient coarser grains to achieve a stable grain skeleton.

  2. Incentive structure in team-based learning: graded versus ungraded Group Application exercises.

    Science.gov (United States)

    Deardorff, Adam S; Moore, Jeremy A; McCormick, Colleen; Koles, Paul G; Borges, Nicole J

    2014-04-21

    Previous studies on team-based learning (TBL) in medical education demonstrated improved learner engagement, learner satisfaction, and academic performance; however, a paucity of information exists on modifications of the incentive structure of "traditional" TBL practices. The current study investigates the impact of modification to conventional Group Application exercises by examining student preference and student perceptions of TBL outcomes when Group Application exercises are excluded from TBL grades. During the 2009-2010 and 2010-2011 academic years, 175 students (95.6% response rate) completed a 22-item multiple choice survey followed by 3 open response questions at the end of their second year of medical school. These students had participated in a TBL supplemented preclinical curriculum with graded Group Application exercises during year one and ungraded Group Application exercises during year two of medical school. Chi-square analyses showed significant differences between grading categories for general assessment of TBL, participation and communication, intra-team discussion, inter-team discussion, student perceptions of their own effort and development of teamwork skills. Furthermore, 83.8% of students polled prefer ungraded Group Application exercises with only 7.2% preferring graded and 9.0% indicating no preference. The use of ungraded Group Application exercises appears to be a successful modification of TBL, making it more "student-friendly" while maintaining the goals of active learning and development of teamwork skills.

  3. Influence of solar radiation absorbed by phytoplankton on the thermal structure and circulation of the tropical Atlantic Ocean

    Science.gov (United States)

    Frouin, Robert; Ueyoshi, Kyozo; Kampel, Milton

    2007-09-01

    Numerical experiments conducted with an ocean general ocean circulation model reveal the potential influence of solar radiation absorbed by phytoplankton on the thermal structure and currents of the Tropical Atlantic Ocean. In the model, solar radiation penetration is parameterized explicitly as a function of chlorophyll-a concentration, the major variable affecting water turbidity in the open ocean. Two types of runs are performed, a clear water (control) run with a constant minimum chlorophyll-a concentration of 0.02 mgm -3, and a turbid water (chlorophyll) run with space- and time-varying chlorophyll-a concentration from satellite data. The difference between results from the two runs yields the biological effects. In the chlorophyll run, nutrients and biology production are implicitly taken into account, even though biogeochemical processes are not explicitly included, since phytoplankton distribution, prescribed from observations, is the result of those processes. Due to phytoplankton-radiation forcing, the surface temperature is higher by 1-2 K on average annually in the region of the North Equatorial current, the Northern part of the South Equatorial current, and the Caribbean system, and by 3-4 K in the region of the Guinea current. In this region, upwelling is reduced, and heat trapped in the surface layers by phytoplankton is not easily removed. The surface temperature is lower by 1 K in the Northern region of the Benguela current, due to increased upwelling. At depth, the equatorial Atlantic is generally cooler, as well as the eastern part of the tropical basin (excluding the region of the sub-tropical gyres). The North and South equatorial currents, as well as the Equatorial undercurrent, are enhanced by as much as 3-4 cms -1, and the circulation of the subtropical gyres is increased. Pole-ward heat transport is slightly reduced North of 35°N, suggesting that phytoplankton, by increasing the horizontal return flow in the subtropical region, may exert a

  4. Movement Coordination: Factor Structure of Development in 5th-7th Grade Girls

    Directory of Open Access Journals (Sweden)

    O. Ivashchenko

    2018-03-01

    Full Text Available The study objective is to determine the structure of coordination abilities development in 5th-7th grade girls. Materials and methods. The participants in the study were 5th grade girls (n = 20, 6th grade girls (n = 23, 7th grade girls (n = 19. The study used the following methods: analysis and collation of scientific and methodological literature, general scientific methods of theoretical level, such as analogy, analysis, synthesis, abstraction, induction, as well as general scientific methods of empirical level: observation, testing, experiment. To evaluate motor preparedness, the study recorded the results of motor tests, body height and weight. The IBM SPSS 20 statistical analysis software was used to process the study materials. A factor analysis was performed, for which the study used principal component analysis with the rotation method: Variamax with Kaiser Normalization. Results. The analysis of similarities shows that the most informative tests in the structure of motor preparedness of the 5th grade girls are the following: test 11 “Evaluation of the ability for vestibular (statokinetic stability. Running with turns” (.884, test 9 “Static equilibrium evaluation by E. Ya. Bondarevsky’s method” (.826, test 6 “Evaluation of the sense of movement speed in sprinting” (.824; of the 6th grade girls — test 11 “Evaluation of the ability for vestibular (statokinetic stability. Running with turns” (0.884, test 9 “Static equilibrium evaluation by E. Ya. Bondarevsky’s method” (.826, test 6 “Evaluation of the sense of movement speed in sprinting” (.824; of the 7th grade girls — test 8 “Evaluation of the ability to differentiate movement speed (reproduction accuracy of running speed at 90% intensity of maximum” (.902, test 11 “Evaluation of the ability for vestibular (statokinetic stability. Running with turns” (.900, test 1 “30 m running (s” (.869. Conclusions. In the structure of

  5. Constitutive Model Of Graded Micro-Structure Obtained Via Strain Induced Phase Transformation

    CERN Document Server

    Ortwein, Rafał

    The literature review has been divided into three main sub-chapters. The first one is concentrated on the general information about stainless steels and their applications. It is important to perform a general overview and get an idea where the results of the present thesis could be applied. Description of all the brands of stainless steels, their microstructures and properties are important, as similar characteristics can be found in the newly created functionally graded structures. The second sub-chapter is an overview of the most important constitutive models and the experimental results for materials that undergo plastic strain induced phase transformation. Finally, the last one is devoted to functionally graded microstructures obtained via strain induced martensitic transformation – the subject of particular importance for the present thesis. As a general note, the literature review is organized mainly in a chronological order. In some cases similar publications or publications of the same Authors were...

  6. Feasibility Study for Using a Linear Transverse Flux Machine as part of the Structure of Point Absorber Wave Energy Converter

    Directory of Open Access Journals (Sweden)

    Ilana Pereira da Costa Cunha

    2017-10-01

    Full Text Available This is a feasibility study for the generation of wave energy by means of a transverse flux machine connected to a device for converting wave energy known as Point Absorber. The article contains literature review on the topic and analysis of data obtained by means of a prototype built in the laboratory. Based on the results, the study concludes that this use is feasible.

  7. Visible light broadband perfect absorbers

    Energy Technology Data Exchange (ETDEWEB)

    Jia, X. L.; Meng, Q. X.; Yuan, C. X.; Zhou, Z. X.; Wang, X. O., E-mail: wxo@hit.edu.cn [School of Science, Harbin Institute of Technology, Harbin 150001 (China)

    2016-03-15

    The visible light broadband perfect absorbers based on the silver (Ag) nano elliptical disks and holes array are studied using finite difference time domain simulations. The semiconducting indium silicon dioxide thin film is introduced as the space layer in this sandwiched structure. Utilizing the asymmetrical geometry of the structures, polarization sensitivity for transverse electric wave (TE)/transverse magnetic wave (TM) and left circular polarization wave (LCP)/right circular polarization wave (RCP) of the broadband absorption are gained. The absorbers with Ag nano disks and holes array show several peaks absorbance of 100% by numerical simulation. These simple and flexible perfect absorbers are particularly desirable for various potential applications including the solar energy absorber.

  8. Efficiency enhancement of perovskite solar cells using structural and morphological improvement of CH3NH3PbI3 absorber layers

    Science.gov (United States)

    Alidaei, Maryam; Izadifard, Morteza; Ghazi, Mohammad E.; Ahmadi, Vahid

    2018-01-01

    Perovskite solar cells have been heavily investigated due to their unique properties such as high power conversion efficiency (PCE), low-cost fabrication by solution processes, high diffusion length, large absorption coefficient, and direct and tunable band gap. PCE of perovskite devices is strongly dependent on the absorber layer properties such as morphology, crystallinity, and compactness, which are required to be optimized. In this work, the CH3NH3PbI3 (170-480 nm) absorber layers with various methylammonium iodine (MAI) concentrations (7, 10, 20 and 40 mg ml-1) and perovskite solar cells with the fluorine-doped tin oxide (400 nm)/C-TiO2 (30 nm)/Meso-TiO2 (400 nm)/CH3NH3PbI3 (170-480 nm)/P3HT (30 nm)/Au (100 nm) structure were fabricated. A two-step solution process was used for deposition of the CH3NH3PbI3 absorber layers. The morphology, crystal structure, and optical properties of the perovskite layer grown on glass and also the photovoltaic properties of the fabricated solar cells were studied. The results obtained showed that by controlling the deposition conditions, due to the reduction in charge recombination, PCE enhancement of the perovskite solar cell (up to 11.6%) was accessible.

  9. Visual Grading and Structural Properties Assessment of Large Cross-Section Pinus radiata D. Don Timber

    Directory of Open Access Journals (Sweden)

    Eva Hermoso Prieto

    2016-04-01

    Full Text Available The use of large cross-section timber for structural purposes has increased in Spain, and knowledge of its properties is strategically necessary. The Spanish visual strength-grading standard UNE 56544 (2011 efficiency applied to large cross-section structural timber was analyzed using a sample of 363 specimens of radiata pine (Pinus radiata D. Don. from the Basque Country and Catalonia, Spain. Different sizes were tested (80 × 120 × 2400 mm3, 150 × 250 × 5600 mm3, 150 × 250 × 4300 mm3, and 200 × 250 × 5000 mm3. Bending strength, modulus of elasticity, and density were obtained, and characteristic values were determined in order to assign strength class according to European standard EN 338 (2010. Knots and twists were the most relevant singularities for visual strength grading. It was concluded that large cross-section Spanish radiata pine timber was suitable for structures, and it was assigned to the C20 strength class.

  10. On the interfacial fracture of porcelain/zirconia and graded zirconia dental structures.

    Science.gov (United States)

    Chai, Herzl; Lee, James J-W; Mieleszko, Adam J; Chu, Stephen J; Zhang, Yu

    2014-08-01

    Porcelain fused to zirconia (PFZ) restorations are widely used in prosthetic dentistry. However, their susceptibility to fracture remains a practical problem. The failure of PFZ prostheses often involves crack initiation and growth in the porcelain, which may be followed by fracture along the porcelain/zirconia (P/Z) interface. In this work, we characterized the process of fracture in two PFZ systems, as well as a newly developed graded glass-zirconia structure with emphases placed on resistance to interfacial cracking. Thin porcelain layers were fused onto Y-TZP plates with or without the presence of a glass binder. The specimens were loaded in a four-point-bending fixture with the thin porcelain veneer in tension, simulating the lower portion of the connectors and marginal areas of a fixed dental prosthesis (FDP) during occlusal loading. The evolution of damage was observed by a video camera. The fracture was characterized by unstable growth of cracks perpendicular to the P/Z interface (channel cracks) in the porcelain layer, which was followed by stable cracking along the P/Z interface. The interfacial fracture energy GC was determined by a finite-element analysis taking into account stress-shielding effects due to the presence of adjacent channel cracks. The resulting GC was considerably less than commonly reported values for similar systems. Fracture in the graded Y-TZP samples occurred via a single channel crack at a much greater stress than for PFZ. No delamination between the residual glass layer and graded zirconia occurred in any of the tests. Combined with its enhanced resistance to edge chipping and good esthetic quality, graded Y-TZP emerges as a viable material concept for dental restorations. Copyright © 2014 Acta Materialia Inc. All rights reserved.

  11. A versatile digitally-graded buffer structure for metamorphic device applications

    Science.gov (United States)

    Ma, Yingjie; Zhang, Yonggang; Chen, Xingyou; Gu, Yi; Shi, Yanhui; Ji, Wanyan; Du, Ben

    2018-04-01

    Exploring more effective buffer schemes for mitigating dislocation deficiencies is the key technology towards higher performance metamorphic devices. Here we demonstrate a versatile metamorphic grading structure consisting of 38-period alternated multilayers of In0.52Al0.48As and In0.82Al0.18As on InP substrate, thicknesses of which in each period were gradually varied in opposite directions from 48.7 and 1.3 nm to 1.3 and 48.7 nm, respectively, akin to a digital alloy. Both preferentially dislocation nucleation and blocking of threading dislocation transmission are observed near the In0.82Al0.18As/In0.52Al0.48As interfaces, which help relax the strain and lower the residual defect density. A 2.6 μm In0.83Ga0.17As pin photodetector is fabricated on this pseudo-substrate, attaining a low dark current density of 2.9  ×  10‑6 A cm‑2 and a high detectivity of 1.8  ×  1010 cmHz1/2W‑1 at room temperature, comparable with the states of the art that on linearly-graded buffer layers. These results indicate such digitally-graded buffer structures are promising for enhancing performances of metamorphic devices, and can be easily generalized to other lattice-mismatched material systems.

  12. The cancer precision medicine knowledge base for structured clinical-grade mutations and interpretations

    Science.gov (United States)

    Huang, Linda; Fernandes, Helen; Zia, Hamid; Tavassoli, Peyman; Rennert, Hanna; Pisapia, David; Imielinski, Marcin; Sboner, Andrea; Rubin, Mark A; Kluk, Michael

    2017-01-01

    Objective: This paper describes the Precision Medicine Knowledge Base (PMKB; https://pmkb.weill.cornell.edu), an interactive online application for collaborative editing, maintenance, and sharing of structured clinical-grade cancer mutation interpretations. Materials and Methods: PMKB was built using the Ruby on Rails Web application framework. Leveraging existing standards such as the Human Genome Variation Society variant description format, we implemented a data model that links variants to tumor-specific and tissue-specific interpretations. Key features of PMKB include support for all major variant types, standardized authentication, distinct user roles including high-level approvers, and detailed activity history. A REpresentational State Transfer (REST) application-programming interface (API) was implemented to query the PMKB programmatically. Results: At the time of writing, PMKB contains 457 variant descriptions with 281 clinical-grade interpretations. The EGFR, BRAF, KRAS, and KIT genes are associated with the largest numbers of interpretable variants. PMKB’s interpretations have been used in over 1500 AmpliSeq tests and 750 whole-exome sequencing tests. The interpretations are accessed either directly via the Web interface or programmatically via the existing API. Discussion: An accurate and up-to-date knowledge base of genomic alterations of clinical significance is critical to the success of precision medicine programs. The open-access, programmatically accessible PMKB represents an important attempt at creating such a resource in the field of oncology. Conclusion: The PMKB was designed to help collect and maintain clinical-grade mutation interpretations and facilitate reporting for clinical cancer genomic testing. The PMKB was also designed to enable the creation of clinical cancer genomics automated reporting pipelines via an API. PMID:27789569

  13. Using glass-graded zirconia to increase delamination growth resistance in porcelain/zirconia dental structures.

    Science.gov (United States)

    Chai, Herzl; Mieleszko, Adam J; Chu, Stephen J; Zhang, Yu

    2018-01-01

    Porcelain fused to zirconia (PFZ) restorations are widely used in prosthetic dentistry. However, their tendency to delaminate along the P/Z interface remains a practical problem so that assessing and improving the interfacial strength are important design aspects. This work examines the effect of modifying the zirconia veneering surface with an in-house felspathic glass on the interfacial fracture resistance of fused P/Z. Three material systems are studied: porcelain fused to zirconia (control) and porcelain fused to glass-graded zirconia with and without the presence of a glass interlayer. The specimens were loaded in a four-point-bend fixture with the porcelain veneer in tension. The evolution of damage is followed with the aid of a video camera. The interfacial fracture energy G C was determined with the aid of a FEA, taking into account the stress shielding effects due to the presence of adjacent channel cracks. Similarly to a previous study on PFZ specimens, the fracture sequence consisted of unstable growth of channel cracks in the veneer followed by stable cracking along the P/Z interface. However, the value of GC for the graded zirconia was approximately 3 times that of the control zirconia, which is due to the good adhesion between porcelain and the glass network structure on the zirconia surface. Combined with its improved bonding to resin-based cements, increased resistance to surface damage and good esthetic quality, graded zirconia emerges as a viable material concept for dental restorations. Copyright © 2017 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  14. Flood Control Structures Research Program. Annotated Bibliography on Grade Control Structures

    Science.gov (United States)

    1991-09-01

    evaluating the effects of geology, geomorphology, soils, land use, and climate on runoff and sediment production from major source areas; (4...Otto, and ,t:iji, Ahmed. 1987. "Theoret- ical Flow Model for Drop Structures," -’. aulic ’ngineering, Proceed- ings of the 1987 National Confere’,ce on...Facilities for Unique Flood Problems," Journal of the-Waterways and Harbors Division, ASCE, Vol 97, No. WWI, pp 185-203. The unusual climatic

  15. Proposal for the completion of outstanding work on the mechanical absorber structure of SDC barrel electromagnetic calorimeter

    International Nuclear Information System (INIS)

    Guarino, V.; Hill, N.; Kicmal, T.; Nasiatka, J.; Petereit, E.; Price, L.; Proudfoot, J.; Stanek, R.; Scherbarth, D.

    1993-01-01

    The High Energy Physics Division at Argonne National Laboratory and Westinghouse Science and Technology Center, Pittsburgh Pennsylvania have worked jointly on a scintillating tile/fiber calorimeter with the SDC collaboration since it's inception in 1989. During the design and prototyping phase of the last three years, we have particularly worked on the development of an innovative cast lead approach to the absorber and the associated design of tile/fiber packaging for the barrel electromagnetic calorimeter (EMC). A full scale prototype program was initiated in 1992 to construct four EMC castings to be mated to respective steel hadronic wedges fabricated in China and presently at Fermilab. This proposal we outline in detail both the tasks that we have completed and those that we propose to complete in order to make the extensive investment in this technology useful to others in the field

  16. Heat resistance and local structure of FeCl2-absorbed crosslinked poly(γ-glutamic acid)

    International Nuclear Information System (INIS)

    Nishida, T.; Kamezawa, H.; Hara, T.; Matsumoto, Y.

    2001-01-01

    Fiber of Japanese food natto (Bacillus subtilis) is known to be superabsorbent poly(γ-glutamic acid) (PGA). NaCl particles precipitate in FeCl 2 -absorbed crosslinked PGA when heated at crystallization temperature of 320 deg C for 10 to 60 min. After heat treatment the Moessbauer spectrum of FeCl 2 -crosslinked PGA consists of a quadrupole doublet due to FeCl 2 x 2H 2 O. The Moessbauer spectrum of anhydrous FeCl 2 reagent heated under the same condition shows an intense sextet due to α-Fe 2 O 3 . These results prove that the superabsorbent polymer, crosslinked PGA, has higher heat resistance. (author)

  17. AN APPROACH TO CHARACTERIZING and EVALUATING ALTERNATIVES FOR THE DECOMMISSIONING OF SUB-GRADE STRUCTURES AT THE PLUTONIUM FINISHING PLANT

    International Nuclear Information System (INIS)

    HOPKINS, A.M.; KLOS, D.B.

    2007-01-01

    In 2002, the Richland Operations Office (RL) of the US Department of Energy (DOE), the US Environmental Protection Agency (EPA), and the Washington State Department of Ecology (Ecology) developed milestones for transitioning the Plutonium Finishing Plant (PFP) facility to a clean slab-on-grade configuration. These milestones required developing an engineering evaluation/cost analysis (EF/CA) for the facility's sub-grade structures and installations as part of a series of evaluations intended to provide for the transition of the facility to a clean slab-on-grade configuration. In addition to supporting decisions for interim actions, the analyses of sub-grade structures and installations performed through this EE/CA will contribute to the remedial investigation feasibility study(ies) and subsequently to the final records of decision for the relevant operable units responsible for site closure in the 200 West Area of the Hanford Site

  18. Mapping coral reefs using consumer-grade drones and structure from motion photogrammetry techniques

    Science.gov (United States)

    Casella, Elisa; Collin, Antoine; Harris, Daniel; Ferse, Sebastian; Bejarano, Sonia; Parravicini, Valeriano; Hench, James L.; Rovere, Alessio

    2017-03-01

    We propose a novel technique to measure the small-scale three-dimensional features of a shallow-water coral reef using a small drone equipped with a consumer-grade camera, a handheld GPS and structure from motion (SfM) algorithms. We used a GoPro HERO4 with a modified lens mounted on a DJI Phantom 2 drone (maximum total take-off weight <2 kg) to perform a 10 min flight and collect 306 aerial images with an overlap equal or greater than 90%. We mapped an area of 8380 m2, obtaining as output an ortho-rectified aerial photomosaic and a bathymetric digital elevation model (DEM) with a resolution of 0.78 and 1.56 cm pixel-1, respectively. Through comparison with airborne LiDAR data for the same area, we verified that the location of the ortho-rectified aerial photomosaic is accurate within 1.4 m. The bathymetric difference between our DEM and the LiDAR dataset is -0.016 ± 0.45 m (1σ). Our results show that it is possible, in conditions of calm waters, low winds and minimal sun glint, to deploy consumer-grade drones as a relatively low-cost and rapid survey technique to produce multispectral and bathymetric data on shallow-water coral reefs. We discuss the utility of such data to monitor temporal changes in topographic complexity of reefs and associated biological processes.

  19. Additive manufacturing of RF absorbers

    Science.gov (United States)

    Mills, Matthew S.

    The ability of additive manufacturing techniques to fabricate integrated electromagnetic absorbers tuned for specific radio frequency bands within structural composites allows for unique combinations of mechanical and electromagnetic properties. These composites and films can be used for RF shielding of sensitive electromagnetic components through in-plane and out-of-plane RF absorption. Structural composites are a common building block of many commercial platforms. These platforms may be placed in situations in which there is a need for embedded RF absorbing properties along with structural properties. Instead of adding radar absorbing treatments to the external surface of existing structures, which adds increased size, weight and cost; it could prove to be advantageous to integrate the microwave absorbing properties directly into the composite during the fabrication process. In this thesis, a method based on additive manufacturing techniques of composites structures with prescribed electromagnetic loss, within the frequency range 1 to 26GHz, is presented. This method utilizes screen printing and nScrypt micro dispensing to pattern a carbon based ink onto low loss substrates. The materials chosen for this study will be presented, and the fabrication technique that these materials went through to create RF absorbing structures will be described. The calibration methods used, the modeling of the RF structures, and the applications in which this technology can be utilized will also be presented.

  20. STRUCTURAL OPTIMIZATION OF FUNCTIONALLY GRADED MATERIALS WITH SMALL CONCENTRATION OF INCLUSIONS

    Directory of Open Access Journals (Sweden)

    DISKOVSKY A. A.

    2017-01-01

    Full Text Available Raising of problem.With an optimal design of inner structure of functionally graded material (FGM based on the classical method of homogenization procedure, in cases of low concentration of inclusions, when the size of inclusions is essentially less than the distance between them, leads to computational difficulties. Purpose – the research to develop a homogenization procedure, allowing solving effectively the problem of optimizing the internal structure of FGM at low concentrations of inclusions and illustration with specific examples. Conclusion. The proposed method allows solving tasks of calculation and optimal design of the internal structure of FGM structures with variable inclusions and with a variable step between them using the same methodology. The optimization is performed using two mechanisms. The first allocation is fixed at the edges of the border areas in which inclusions are absent. The second optimization mechanism is the distribution of inclusions sizes under the law, coinciding with the distribution law of an external load. Alternate step for the step should be reduced in areas with greater intensity of the external load.

  1. Sampling and Analysis Plan for Release of the 105-C Below-Grade Structures and Underlying Soils

    International Nuclear Information System (INIS)

    Bauer, R.G.

    1998-02-01

    This sampling and analysis plan (SAP) presents the rationale and strategies for the sampling, field measurements, and analyses of the below-grade concrete structures from the Hanford 105-C Reactor Building and the underlying soils consistent with the land-use assumptions in the Record of Decision for the U.S. Department of Energy 100-BC-1, 100-DR-1, and 100-HR-1 Operable Units (ROD) (EPA 1995). This structure is one of nine surplus production reactors in the 100 Area of the Hanford Site. This SAP is based on the data quality objectives developed for the 105-C below-grade structures and underlying soils (BHI 1997)

  2. Ultra-Thin Multi-Band Polarization-Insensitive Microwave Metamaterial Absorber Based on Multiple-Order Responses Using a Single Resonator Structure

    Directory of Open Access Journals (Sweden)

    Yong Zhi Cheng

    2017-10-01

    Full Text Available We design an ultra-thin multi-band polarization-insensitive metamaterial absorber (MMA using a single circular sector resonator (CSR structure in the microwave region. Simulated results show that the proposed MMA has three distinctive absorption peaks at 3.35 GHz, 8.65 GHz, and 12.44 GHz, with absorbance of 98.8%, 99.7%, and 98.3%, respectively, which agree well with an experiment. Simulated surface current distributions of the unit-cell structure reveal that the triple-band absorption mainly originates from multiple-harmonic magnetic resonance. The proposed triple-band MMA can remain at a high absorption level for all polarization of both transverse-electric (TE and transverse-magnetic (TM modes under normal incidence. Moreover, by further optimizing the geometric parameters of the CSRs, four-band and five-band MMAs can also be obtained. Thus, our design will have potential application in detection, sensing, and stealth technology.

  3. Dynamic crushing of uniform and density graded cellular structures based on the circle arc model

    Directory of Open Access Journals (Sweden)

    Jianjun Zhang

    Full Text Available AbstractA new circle-arc model was established to present the cellular structure. Dynamic response of models with density gradients under constant velocities is investigated by employing Ls-dyna 971. Compared with the uniform models, the quasi-static plateau stress of different layers seems a significant parameter correlated with the deformation mode except for inertia effect when the density gradient is introduced. The impact velocity becomes much more vital on the deformation of the unit cell than the density gradient. The stress at both the impact and stationary sides is investigated in details. Furthermore, the stress-strain curve is compared with the modified shock wave theory. The density gradient does have some remarkable influence on the energy absorption capability, and a certain density gradient is not always beneficial to the energy absorption. Irrespective of the impact velocity, there seems always a critical strain where the energy absorbed by all these specimens could approximate to nearly the same value. So the critical strain-velocity curve is plotted and gives the beneficial area for energy absorption pertinent to density gradients and impact velocity.

  4. Annealing effect on the structural and optical properties of Cr/α-Cr2O3 monodispersed particles based solar absorbers

    International Nuclear Information System (INIS)

    Khamlich, S.; McCrindle, R.; Nuru, Z.Y.; Cingo, N.; Maaza, M.

    2013-01-01

    Graphical abstract: A cost-effective and environmentally friendly green chemical method, the so-called aqueous chemical growth (ACG) method, was used to deposit chromium/alpha-chromium(III) oxide, Cr/α-Cr 2 O 3 , monodispersed particles, for solar absorbers applications. Highlights: ► Cr/α-Cr 2 O 3 have been deposited by the aqueous chemical growth (ACG) method. ► High temperature annealing affects the optical selectivity of the deposited particles. ► Oxygen diffusion to the interface at high temperature results in the oxidization of the substrate. - Abstract: A cost-effective and environmentally friendly green chemical method, the so-called aqueous chemical growth (ACG) method, was used to deposit chromium/alpha-chromium(III) oxide, Cr/α-Cr 2 O 3 , monodispersed particles, for solar absorbers applications. The deposited particles were annealed at various temperatures in a hydrogen atmosphere for 2 h to study the annealing temperature dependence of the structural, chemical and optical properties of the particles grown on tantalum substrates. The deposited Cr/α-Cr 2 O 3 was characterized by X-ray diffraction (XRD), attenuated total reflection (ATR), scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), and diffuse reflectance UV–vis–NIR spectroscopy. The XRD and ATR analysis indicated that by increasing annealing temperature, the particles crystallinity was improved and Ta 2 O 5 was formed around 600 °C, due to the fast oxygen diffusion from the deposited α-Cr 2 O 3 toward the tantalum substrate. The optical measurements show that samples annealed at 400 and 500 °C exhibit the targeted high absorbing optical characteristics of “Black chrome”, while those annealed below 400 °C and above 500 °C show a significant low absorptivity and high emissivity.

  5. Structural changes caused by radiation-induced reduction and radiolysis: the effect of X-ray absorbed dose in a fungal multicopper oxidase

    International Nuclear Information System (INIS)

    De la Mora, Eugenio; Lovett, Janet E.; Blanford, Christopher F.; Garman, Elspeth F.; Valderrama, Brenda; Rudino-Pinera, Enrique

    2012-01-01

    Radiation-induced reduction, radiolysis of copper sites and the effect of pH value together with the concomitant geometrical distortions of the active centres were analysed in several fungal (C. gallica) laccase structures collected at cryotemperature. This study emphasizes the importance of careful interpretation when the crystallographic structure of a metalloprotein is described. X-ray radiation induces two main effects at metal centres contained in protein crystals: radiation-induced reduction and radiolysis and a resulting decrease in metal occupancy. In blue multicopper oxidases (BMCOs), the geometry of the active centres and the metal-to-ligand distances change depending on the oxidation states of the Cu atoms, suggesting that these alterations are catalytically relevant to the binding, activation and reduction of O 2 . In this work, the X-ray-determined three-dimensional structure of laccase from the basidiomycete Coriolopsis gallica (Cg L), a high catalytic potential BMCO, is described. By combining spectroscopic techniques (UV–Vis, EPR and XAS) and X-ray crystallography, structural changes at and around the active copper centres were related to pH and absorbed X-ray dose (energy deposited per unit mass). Depletion of two of the four active Cu atoms as well as low occupancies of the remaining Cu atoms, together with different conformations of the metal centres, were observed at both acidic pH and high absorbed dose, correlating with more reduced states of the active coppers. These observations provide additional evidence to support the role of flexibility of copper sites during O 2 reduction. This study supports previous observations indicating that interpretations regarding redox state and metal coordination need to take radiation effects explicitly into account

  6. Symptom and structure modification in osteoarthritis with pharmaceutical-grade chondroitin sulfate: what's the evidence?

    Science.gov (United States)

    Hochberg, M; Chevalier, X; Henrotin, Y; Hunter, D J; Uebelhart, D

    2013-03-01

    Osteoarthritis is a chronic disease characterized by irreversible damage to joint structures, including loss of articular cartilage, osteophyte formation, alterations in the subchondral bone and synovial inflammation. It has been shown that chondroitin sulfate interferes with the progression of structural changes in joint tissues and is used in the management of patients with osteoarthritis. This review summarizes data from relevant reports describing the mechanisms of action of chondroitin sulfate that may explain the beneficial effects of the drug and examines the evidence for clinical efficacy of oral chondroitin sulfate in osteoarthritis. Data included in the review were derived from a literature search in PubMed. Literature searches were performed in PubMed using the search terms 'chondroitin sulfate', 'pharmaceutical-grade', 'osteoarthritis', 'randomized clinical trials', 'humans'. The MEDLINE database was searched from January 1996 through August 2012 for all randomized controlled trials, meta-analyses, systematic reviews, and review articles of chondroitin sulfate in osteoarthritis. Chondroitin sulfate exerts in vitro a beneficial effect on the metabolism of different cell lines: chondrocytes, synoviocytes and cells from subchondral bone, all involved in osteoarthritis. It increases type II collagen and proteoglycan synthesis in human articular chondrocytes and is able to reduce the production of some pro-inflammatory factors and proteases, to reduce the cellular death process, and improve the anabolic/catabolic balance of the extracellular cartilage matrix (ECM). Clinical trials have reported a beneficial effect of chondroitin sulfate on pain and function. The structure-modifying effects of chondroitin sulfate have been reported and analyzed in recent meta-analyses. The results in knee osteoarthritis demonstrate a small but significant reduction in the rate of decline in joint space width. Because chondroitin sulfate quality of several nutraceuticals has

  7. Effect of structural characteristics of corncob hemicelluloses fractionated by graded ethanol precipitation on furfural production.

    Science.gov (United States)

    Li, Huiling; Dai, Qingqing; Ren, Junli; Jian, Longfei; Peng, Feng; Sun, Runcang; Liu, Guoliang

    2016-01-20

    In the present study, a graded ethanol precipitation technique was employed to obtain hemicelluloses from the alkali-extracted corncob liquid. The relationship between the structural characteristics of alkali-soluble corncob hemicelluloses and the production of furfural was investigated by a heterogeneous process in a biphasic system. Results showed that alkali-soluble corncob hemicelluloses mainly consisted of glucuronoarabinoxylans and L-arabino-(4-O-methylglucurono)-D-xylans, and the drying way had less influence on the sugar composition, molecular weights and the functional groups of hemicelluloses obtained by the different ethanol concentration precipitation except for the thermal property, the amorphous structure and the ability for the furfural production. Furthermore, alkali-soluble corncob hemicelluloses with higher xylose content, lower branch degree, higher polydispersity and crystallinity contributed to the furfural production. A highest furfural yield of 45.41% with the xylose conversion efficiency of 99.06% and the furfural selectivity of 45.84% was obtained from the oven-dried hemicelluloses precipitated at the 30% (v/v) ethanol concentration. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Structural dynamics of phenylisothiocyanate in the light-absorbing excited states: Resonance Raman and complete active space self-consistent field calculation study

    International Nuclear Information System (INIS)

    Ouyang, Bing; Xue, Jia-Dan; Zheng, Xuming; Fang, Wei-Hai

    2014-01-01

    The excited state structural dynamics of phenyl isothiocyanate (PITC) after excitation to the light absorbing S 2 (A′), S 6 (A′), and S 7 (A′) excited states were studied by using the resonance Raman spectroscopy and complete active space self-consistent field method calculations. The UV absorption bands of PITC were assigned. The vibrational assignments were done on the basis of the Fourier transform (FT)-Raman and FT-infrared measurements, the density-functional theory computations, and the normal mode analysis. The A-, B-, and C-bands resonance Raman spectra in cyclohexane, acetonitrile, and methanol solvents were, respectively, obtained at 299.1, 282.4, 266.0, 252.7, 228.7, 217.8, and 208.8 nm excitation wavelengths to probe the corresponding structural dynamics of PITC. The results indicated that the structural dynamics in the S 2 (A′), S 6 (A′), and S 7 (A′) excited states were very different. The conical intersection point CI(S 2 /S 1 ) were predicted to play important role in the low-lying excited state decay dynamics. Two major decay channels were predicted for PITC upon excitation to the S 2 (A′) state: the radiative S 2,min → S 0 transition and the nonradiative S 2 → S 1 internal conversion via CI(S 2 /S 1 ). The differences in the decay dynamics between methyl isothiocyanate and PITC in the first light absorbing excited state were discussed. The role of the intersystem crossing point ISC(S 1 /T 1 ) in the excited state decay dynamics of PITC is evaluated

  9. Multi-channel coherent perfect absorbers

    KAUST Repository

    Bai, Ping

    2016-05-18

    The absorption efficiency of a coherent perfect absorber usually depends on the phase coherence of the incident waves on the surfaces. Here, we present a scheme to create a multi-channel coherent perfect absorber in which the constraint of phase coherence is loosened. The scheme has a multi-layer structure such that incident waves in different channels with different angular momenta can be simultaneously and perfectly absorbed. This absorber is robust in achieving high absorption efficiency even if the incident waves become "incoherent" and possess "random" wave fronts. Our work demonstrates a unique approach to designing highly efficient metamaterial absorbers. © CopyrightEPLA, 2016.

  10. Multi-channel coherent perfect absorbers

    KAUST Repository

    Bai, Ping; Wu, Ying; Lai, Yun

    2016-01-01

    The absorption efficiency of a coherent perfect absorber usually depends on the phase coherence of the incident waves on the surfaces. Here, we present a scheme to create a multi-channel coherent perfect absorber in which the constraint of phase coherence is loosened. The scheme has a multi-layer structure such that incident waves in different channels with different angular momenta can be simultaneously and perfectly absorbed. This absorber is robust in achieving high absorption efficiency even if the incident waves become "incoherent" and possess "random" wave fronts. Our work demonstrates a unique approach to designing highly efficient metamaterial absorbers. © CopyrightEPLA, 2016.

  11. Potassium doped methylammonium lead iodide (MAPbI3) thin films as a potential absorber for perovskite solar cells; structural, morphological, electronic and optoelectric properties

    Science.gov (United States)

    Muzammal uz Zaman, Muhammad; Imran, Muhammad; Saleem, Abida; Kamboh, Afzal Hussain; Arshad, Muhammad; Khan, Nawazish Ali; Akhter, Parvez

    2017-10-01

    In this article, we have demonstrated the doping of K in the light absorbing CH3NH3PbI3 perovskite i.e. (M = CH3, A = NH3; x = 0-1). One of the major merits of methylammonium lead iodide (CH3NH3PbI3) perovskites is that they act as efficient absorbing material of light in photovoltaic cell imparting long carrier lifetime and optimum band gap. The structural, morphological, electronic and optoelectric properties of potassium (K) doped light absorber methylammonium lead iodide (CH3NH3PbI3) perovskites are reported here i.e. Kx(MA)1-xPbI3 (M = CH3, A =NH3; x = 0-1). The thin films of perovskites (x = 0-1) were deposited by spin coating on cleaned FTO substrates and characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), current-voltage (IV), X-ray photoelectron spectroscopy (XPS) and Diffused reflectance spectroscopy (DRS) analysis. The organic constituents i.e. MA = CH3NH3, in perovskites solar cells induce instability even at the room temperature. To overcome such instabilities we have replaced the organic constituents by K because both of them have electropositive nature. Potassium successfully replaces the CH3NH3. Initially, this compound grows in a tetragonal crystal structure, however, beyond 30% doping of potassium orthorhombic distortions are induced in the parent tetragonal unit cell. Such phase transformation is microscopically visible in the electron micrographs of doped samples; cubic grains for MAPbI3 begin to transform into strip like structures in K-doped samples. The resistance of the samples is decreased for partial K-doping, which we suggested to be arising due to the electropositive nature of K. It is observed that the binding energy difference between Pb4f and I3d core levels are very similar in all the investigated systems and show formal oxidation states. Also, the partially doped samples showed increased absorption and bandgaps around 1.5 eV which is an optimum value for solar absorption.

  12. The Perfectly Matched Layer absorbing boundary for fluid-structure interactions using the Immersed Finite Element Method.

    Science.gov (United States)

    Yang, Jubiao; Yu, Feimi; Krane, Michael; Zhang, Lucy T

    2018-01-01

    In this work, a non-reflective boundary condition, the Perfectly Matched Layer (PML) technique, is adapted and implemented in a fluid-structure interaction numerical framework to demonstrate that proper boundary conditions are not only necessary to capture correct wave propagations in a flow field, but also its interacted solid behavior and responses. While most research on the topics of the non-reflective boundary conditions are focused on fluids, little effort has been done in a fluid-structure interaction setting. In this study, the effectiveness of the PML is closely examined in both pure fluid and fluid-structure interaction settings upon incorporating the PML algorithm in a fully-coupled fluid-structure interaction framework, the Immersed Finite Element Method. The performance of the PML boundary condition is evaluated and compared to reference solutions with a variety of benchmark test cases including known and expected solutions of aeroacoustic wave propagation as well as vortex shedding and advection. The application of the PML in numerical simulations of fluid-structure interaction is then investigated to demonstrate the efficacy and necessity of such boundary treatment in order to capture the correct solid deformation and flow field without the requirement of a significantly large computational domain.

  13. Investigating the effects of stress on the pore structures of nuclear grade graphites

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, Joshua E.L., E-mail: joshua.taylor@postgrad.manchester.ac.uk; Hall, Graham N., E-mail: graham.n.hall@manchester.ac.uk; Mummery, Paul M., E-mail: paul.m.mummery@manchester.ac.uk

    2016-03-15

    Graphite is used as a moderating material and as a structural component in a number of current generation nuclear reactors. During reactor operation stresses develop in the graphite components, causing them to deform. It is important to understand how the microstructure of graphite affects the material's response to these stresses. A series of experiments were performed to investigate how the pore structures of Pile Grade A and Gilsocarbon graphites respond to loading stresses. A compression rig was used to simulate the build-up of operational stresses in graphite components, and a confocal laser microscope was used to study variation of a number of important pore properties. Values of elastic modulus and Poisson's ratio were calculated and compared to existing literature to confirm the validity of the experimental techniques. Mean pore areas were observed to decrease linearly with increasing applied load, mean pore eccentricity increased linearly, and a small amount of clockwise pore rotation was observed. The response to build-up of stresses was dependent on the orientation of the pores and basal planes and the shapes of the pores with respect to the loading axis. It was proposed that pore closure and pore reorientation were competing processes. Pore separation was quantified using ‘nearest neighbour’ and Voronoi techniques, and non-pore regions were found to shrink linearly with increasing applied load. - Highlights: • Effects of stress on pore structures of Gilsocarbon and PGA graphites were studied. • Application of a compressive load was used to generate stresses in graphite. • Inverse linear relationship between stress and pore area was observed. • Mean pore eccentricity increased, clockwise pore rotation observed. • Separation of pores quantified using Voronoi and ‘nearest-neighbour’ methods.

  14. Graded Structure in Sexual Definitions: Categorizations of Having "Had Sex" and Virginity Loss Among Homosexual and Heterosexual Men and Women.

    Science.gov (United States)

    Horowitz, Ava D; Bedford, Edward

    2017-08-01

    Definitions of sexual behavior display a robust hierarchy of agreement regarding whether or not acts should be classed as, for example, sex or virginity loss. The current research offers a theoretical explanation for this hierarchy, proposing that sexual definitions display graded categorical structure, arising from goodness of membership judgments. Moderation of this graded structure is also predicted, with the focus here on how sexual orientation identity affects sexual definitions. A total of 300 18- to 30-year-old participants completed an online survey, rating 18 behaviors for how far each constitutes having "had sex" and virginity loss. Participants fell into one of four groups: heterosexual male or female, gay male or lesbian. The predicted ratings hierarchy emerged, in which bidirectional genital acts were rated significantly higher than unidirectional or nonpenetrative contact, which was in turn rated significantly higher than acts involving no genital contact. Moderation of graded structure was also in line with predictions. Compared to the other groups, the lesbian group significantly upgraded ratings of genital contact that was either unidirectional or nonpenetrative. There was also evidence of upgrading by the gay male sample of anal intercourse ratings. These effects are theorized to reflect group-level variation in experience, contextual perspective, and identity-management. The implications of the findings in relation to previous research are discussed. It is suggested that a graded structure approach can greatly benefit future research into sexual definitions, by permitting variable definitions to be predicted and explained, rather than merely identified.

  15. Properties of MIS structures based on graded-gap HgCdTe grown by molecular beam epitaxy

    International Nuclear Information System (INIS)

    Voitsekhovskii, A. V.; Nesmelov, S. N.; Dzyadookh, S. M.; Varavin, V. S.; Dvoretskii, S. A.; Mikhailov, N. N.; Sidorov, Yu. G.; Vasiliev, V. V.

    2008-01-01

    The effect of near-surface graded-gap layers on the electrical characteristics of MIS structures fabricated based on heteroepitaxial Hg 1-x Cd x Te films grown by molecular beam epitaxy with a two-layer SiO 2 /Si 3 N 4 insulator and anodic oxide film is studied experimentally. It is shown that a larger modulation of capacitance (depth and width of the valley) is observed compared with the structures without the graded-gap layer. The field dependences of photovoltage of MIS structures with the graded-gap layers had a classical form and were characterized by a drop only in the enrichment region. For the structures without the graded-gap layer with x = 0.22, a drop in the voltage dependence of the photocurrent is observed in the region of pronounced inversion. This drop is governed by limitation of the space charge region by processes of tunneling generation via deep levels. The properties of the HgCdTe-insulator interfaces are studied.

  16. Factor structure of internet addiction test for students in senior grades of elementary school

    Directory of Open Access Journals (Sweden)

    Popović-Ćitić Branislava

    2013-01-01

    Full Text Available One of the actual issues in the field of Internet use disorders is related to the validity and reliability of measurement instruments. The aim of this study was to examine, on non-clinical population of younger adolescents, the factor structure of the Internet Addiction Test - IAT, as one of the oldest and most widely used instruments in this field. The sample consisted of 814 Belgrade elementary school students, from fifth to eighth grade, with the average age of 12.9 years. Using exploratory factor analysis, two factors were extracted, together accounting for 46.32% of the total variance. The first factor, which accounted for 38.47% of the total variance, appeared to measure inability to control Internet use and consequences that arise as a result of excessive Internet use, while the second factor accounted for 7.85% of the variance and appeared to measure preoccupation to the Internet, responses to deprivation and replacement of real to virtual social relationships. The reliability of the whole scale, expressed by Cronbach alpha coefficient of internal consistency, was 0.91. High reliability coefficients are retained on the subscale that represent the factor, so coefficient of reliability for the first scale was 0.87, and 0.85 for the second. These findings were discussed in the context of possible modifications of the instrument and compared with the results of international research studies testing the validity and reliability of the IAT in specific national samples.

  17. Growth, structure, and performance of depth-graded W/Si multilayers for hard x-ray optics

    DEFF Research Database (Denmark)

    Windt, D.L.; Christensen, Finn Erland; Craig, W.W.

    2000-01-01

    that the dominant interface imperfection in these films is interfacial diffuseness; interfacial roughness is minimal (sigma(r)similar to 0.175 nm) in structures prepared under optimal conditions, but can increase under conditions in which the beneficial effects of energetic bombardment during growth are compromised......-graded W/Si multilayer structures, and high-resolution transmission electron microscopy (TEM) and selected area electron diffraction (SAED) to characterize the interface structure and layer morphology as a function of depth in an optimized depth-graded multilayer. From x-ray analysis we find interface......), and somewhat larger interface widths (i.e., sigma=0.35-0.4 nm) for structures grown at higher Ar pressures, higher background pressures, or with larger target-to-substrate distances. We find no variation in interface widths with magnetron power. Nonspecular x-ray reflectance analysis and TEM suggest...

  18. Fabrication of Graded Porous and Skin-Core Structure RDX-Based Propellants via Supercritical CO2 Concentration Profile

    Science.gov (United States)

    Yang, Weitao; Li, Yuxiang; Ying, Sanjiu

    2015-04-01

    A fabrication process to produce graded porous and skin-core structure propellants via supercritical CO2 concentration profile is reported in this article. It utilizes a partial gas saturation technique to obtain nonequilibrium gas concentration profiles in propellants. Once foamed, the propellant obtains a graded porous or skin-pore structure. This fabrication method was studied with RDX(Hexogen)-based propellant under an SC-CO2 saturation condition. The principle was analyzed and the one-dimensional diffusion model was employed to estimate the gas diffusion coefficient and to predict the gas concentration profiles inside the propellant. Scanning electron microscopy images were used to analyze the effects of partial saturation on the inner structure. The results also suggested that the sorption time and desorption time played an important role in gas profile generation and controlled the inner structure of propellants.

  19. Fast plasma sintering delivers functional graded materials components with macroporous structures and osseointegration properties.

    Science.gov (United States)

    Godoy, R F; Coathup, M J; Blunn, G W; Alves, A L; Robotti, P; Goodship, A E

    2016-04-13

    We explored the osseointegration potential of two macroporous titanium surfaces obtained using fast plasma sintering (FPS): Ti macroporous structures with 400-600 µmØ pores (TiMac400) and 850-1000 µmØ pores (TiMac850). They were compared against two surfaces currently in clinical use: Ti-Growth® and air plasma spray (Ti-Y367). Each surface was tested, once placed over a Ti-alloy and once onto a CoCr bulk substrate. Implants were placed in medial femoral condyles in 24 sheep. Samples were explanted at four and eight weeks after surgery. Push-out loads were measured using a material-testing system. Bone contact and ingrowth were assessed by histomorphometry and SEM and EDX analyses. Histology showed early osseointegration for all the surfaces tested. At 8 weeks, TiMac400, TiMac850 and Ti-Growth® showed deep bone ingrowth and extended colonisation with newly formed bone. The mechanical push-out force was equal in all tested surfaces. Plasma spray surfaces showed greater bone-implant contact and higher level of pores colonisation with new bone than FPS produced surfaces. However, the void pore area in FPS specimens was significantly higher, yet the FPS porous surfaces allowed a deeper osseointegration of bone to implant. FPS manufactured specimens showed similar osseointegration potential to the plasma spray surfaces for orthopaedic implants. FPS is a useful technology for manufacturing macroporous titanium surfaces. Furthermore, its capability to combine two implantable materials, using bulk CoCr with macroporous titanium surfaces, could be of interest as it enables designers to conceive and manufacture innovative components. FPS delivers functional graded materials components with macroporous structures optimised for osseointegration.

  20. Data Quality Objectives Summary Report for the Release of the 105-C Below-Grade Structures and Underlying Soils

    International Nuclear Information System (INIS)

    Bauer, R.G.

    1999-01-01

    The C Reactor is associated with the 100-BC-2 Operable Unit. The below-ground structures of the C Reactor are scheduled for decontamination and decommissioning (D and D). These structures include the fuel storage basin, lift station, and other below-grade rooms and tunnels. The goal of the data quality objectives process is to establish the sampling and analysis design strategy to support decontamination and closeout decisions

  1. Data Quality Objectives Summary Report for the Release of the 105-C Below-Grade Structures and Underlying Soils

    International Nuclear Information System (INIS)

    Bauer, R.G.

    1998-01-01

    The C Reactor is associated with the 100-BC-2 Operable Unit. The below-ground structures of the C Reactor are scheduled for decontamination and decommissioning (D and D). These structures include the fuel storage basin, lift station, and other below-grade rooms and tunnels. The goal of the data quality objectives process is to establish the sampling and analysis design strategy to support decontamination and closeout decisions

  2. An at-grade stabilization structure impact on runoff and suspended sediment

    Science.gov (United States)

    Minks, Kyle R.; Lowery, Birl; Madison, Fred W.; Ruark, Matthew; Frame, Dennis R.; Stuntebeck, Todd D.; Komiskey, Matthew J.

    2012-01-01

    In recent years, agricultural runoff has received more attention as a major contributor to surface water pollution. This is especially true for the unglaciated area of Wisconsin, given this area's steep topography, which makes it highly susceptible to runoff and soil loss. We evaluated the ability of an at-grade stabilization structure (AGSS), designed as a conservation practice to reduce the amount of overland runoff and suspended sediment transported to the surface waters of an agricultural watershed. Eight years of storm and baseflow data collected by the US Geological Survey–Wisconsin Water Science Center on a farm in west central Wisconsin were analyzed for changes in precipitation, storm runoff volume, and suspended sediment concentration before and after installation of an AGSS. The agricultural research site was designed as a paired watershed study in which monitoring stations were installed on the perennial streams draining both control and treatment watersheds. Linear mixed effects model analyses were conducted to determine if any statistically significant changes occurred in the water quality parameters before and after the AGSS was installed. Results indicated no significant changes (p = 0.51) in average event precipitation and runoff volumes before and after installation of the AGSS in either the treatment (NW) or control (SW) watersheds. However, the AGSS did significantly reduce the average suspended sediment concentration in the event runoff water (p = 0.02) in the NW from 972 to 263 mg L–1. In addition, particle size analyses, using light diffraction techniques, were conducted on soil samples taken from within the AGSS and adjacent valley and ridge top to determine if suspended sediments were being retained within the structure. Statistical analysis revealed a significantly (p clay inside the AGSS (37%) than outside (30%). These results indicate that the AGSS was successful in reducing the amount of suspended sediment transported to nearby

  3. Functionally Graded Polyimide Nanocomposite Foams for Ablative and Inflatable/Flexible/Deplorable Structures, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of the proposed research is to develop functionally graded polyimide foams as light-weight, high performance thermal protection systems (TPS) for...

  4. Tuning Structure and Properties of Graded Triblock Terpolymer-Based Mesoporous and Hybrid Films

    KAUST Repository

    Phillip, William A.; Mika Dorin, Rachel; Werner, Jörg; Hoek, Eric M. V.; Wiesner, Ulrich; Elimelech, Menachem

    2011-01-01

    -responsive, and contain pores with a nearly monodisperse diameter. These results suggest that moving to multiblock polymers and their hybrids may open new paths to produce high-performance graded membranes for filtration, separations, nanofluidics, catalysis, and drug

  5. The changes in the electronic structure of B2 FeAl alloy with a Fe antisite and absorbed hydrogen

    International Nuclear Information System (INIS)

    Gonzalez, E.A.; Jasen, P.V.; Luna, R.; Bechthold, P.; Juan, A.; Brizuela, G.

    2009-01-01

    The electronic structure and bonding in a B2 FeAl alloy with and without hydrogen interaction with a Fe antisite were computed using a density functional theoretical method. The hydrogen absorption turns out to be a favorable process. The hydrogen was found close to an octahedral site where one of its Al capped is replaced by a Fe antisite. The Fe-H distance is of 1.45 A same as the Al-H distance. The density of states (DOS) curves show several peaks below the d metal band which is made up mostly of hydrogen based states (>50% H 1s ) while the metal contribution in this region includes mainly s and p orbitals. An electron transfer of nearby 0.21e - comes from the metal to the H. The overlap population values reveal metal-metal bond breaking, the intermetallic bond being the most affected. The H bond mainly with the Al atom and the reported Fe-H overlap population is much lower than that corresponding to FePd alloys and BCC Fe. The changes in the overlap population show the Fe-Al bond is weakened nearly 41.5% after H absorption, while the Fe-Fe bond is only weakened 34.5%. H also develops a stronger bond with the Al atoms. The main bond is developed with Al being twice stronger than Fe-H.

  6. Eddy current testing on structures of nuclear-grade IG-110 graphite for acceptance test in HTTR

    International Nuclear Information System (INIS)

    Ishihara, Masahiro; Saikusa, Akio; Iyoku, Tatsuo

    1993-09-01

    Core and core support graphite structures in the HTTR are mainly made of IG-110 graphite which is fine-grained isotropic and nuclear-grade. Nondestructive inspection with eddy current testing is planned to be applied to these graphite structures. Eddy current testing is widely applied to metallic structures and its testing method has been already established. On the other hand, the characteristics of graphite are quite different in micro-structure from these of metals. Therefore, the eddy current testing method provided for metallic structures can not be applied directly to graphite structures. Thus the eddy current testing method and condition were established for the graphite structures made of IG-110 graphite. (author)

  7. Radiation sterilization of absorbent cotton and of absorbent gauze

    International Nuclear Information System (INIS)

    Hosobuchi, Kazunari; Oka, Mitsuru; Kaneko, Akira; Ishiwata, Hiroshi.

    1986-01-01

    The bioburden of absorbent cotton and of absorbent gauze and their physical and chemical characteristics after irradiation are investigated. The survey conducted on contaminants of 1890 cotton samples from 53 lots and 805 gauze samples from 56 lots showed maximum numbers of microbes per g of the cotton and gauze were 859 (an average of 21.4) and 777 (an average of 42.2), respectively. Isolation and microbiological and biochemical tests of representative microbes indicated that all of them, except one, were bacilli. The sterilization dose at 10 -6 of sterlity assurance level was found to be 2.0 Mrad when irradiated the spores loaded on paper strips and examined populations having graded D values from 0.10 to 0.28 Mrad. The sterilization dose would be about 1.5 Mrad if subjected the average numbers of contaminants observed in this study to irradiation. No significant differences were found between the irradiated samples and control up to 2 Mrad in tensile strength, change of color, absorbency, sedimentation rate, soluble substances, and pH of solutions used for immersion and other tests conventionally used. These results indicate that these products can be sterilized by irradiation. (author)

  8. Structural and magnetic properties of La{sup 3+} substituted barium−natural nanoferrites as microwave absorber in X-band

    Energy Technology Data Exchange (ETDEWEB)

    Widanarto, W., E-mail: wahyu.widanarto@unsoed.ac.id [Department of Physics, FMIPA, Universitas Jenderal Soedirman, Jl. dr. Soeparno 61 Purwokerto 53123 (Indonesia); Amirudin, F. [Department of Physics, FMIPA, Universitas Jenderal Soedirman, Jl. dr. Soeparno 61 Purwokerto 53123 (Indonesia); Ghoshal, S.K. [Department of Physics, AMORG, Faculty of Science, Universiti Teknologi Malaysia, Johor Bahru, Skudai 81310 (Malaysia); Effendi, M.; Cahyanto, W.T. [Department of Physics, FMIPA, Universitas Jenderal Soedirman, Jl. dr. Soeparno 61 Purwokerto 53123 (Indonesia)

    2017-03-15

    Selection of proper microwave absorbers in the X-band is vital to prevent the interference issues that often damage devices and cause signal degradation. In this spirit, we prepared three La{sup 3+} substituted barium-natural nanoferrites (BNFs) samples with chemical composition of BaO:(x)La{sub 2}O{sub 3}:(6-x)Fe{sub 2}O{sub 3} (x=0, 0.1, 0.2 in mol) via solid-state reaction route. Synthesized samples were characterized via SEM, XRD, VSM, and VNA measurements to determine the La{sup 3+} ions concentration dependent variation in the structural, magnetic and microwave absorption properties. Transmission/reflection line (TRL) method was used to evaluate the samples reflection loss. La{sup 3+} free samples sintered at 1100 °C revealed hexagonal BaFe{sub 12}O{sub 19} and rhombohedral Fe{sub 2}O{sub 3} phases. SEM images displayed the growth of new particle with the average size of 0.2 – 0.8 µm as filler in BNFs. Furthermore, an incorporation of La{sup 3+} into the BNF system manifested the emergence of new BaLa{sub 2}Fe{sub 2}O{sub 7} tetragonal crystal phase. The average crystallite size of BNF was found to decrease with increasing La{sup 3+} ion concentrations. Conversely, substitution of La{sup 3+} in the BNF caused insignificant changes in the magnetic properties, the real part of the relative permittivity and the natural resonance frequency. Meanwhile, a reasonable shift in the microwave frequency absorption and enhancement in the reflection loss was evidenced due to the inclusion of La{sup 3+}. BNF sample containing 0.2 mol La{sub 2}O{sub 3} exhibited a saturation magnetization and magnetic field anisotropy of 19.02 and 0.36 T, respectively, where the maximum reflection loss is discerned to be −26.61 dB at 10.87 GHz with 1.25 GHz bandwidth. This new class of ferrites may be prospective for microwave absorber in the X-band. - Highlights: • La{sup 3+} ions substitution into barium–natural nanoferrite via the solid-state reaction. • Influence of La{sup 3

  9. Methods for absorbing neutrons

    Science.gov (United States)

    Guillen, Donna P [Idaho Falls, ID; Longhurst, Glen R [Idaho Falls, ID; Porter, Douglas L [Idaho Falls, ID; Parry, James R [Idaho Falls, ID

    2012-07-24

    A conduction cooled neutron absorber may include a metal matrix composite that comprises a metal having a thermal neutron cross-section of at least about 50 barns and a metal having a thermal conductivity of at least about 1 W/cmK. Apparatus for providing a neutron flux having a high fast-to-thermal neutron ratio may include a source of neutrons that produces fast neutrons and thermal neutrons. A neutron absorber positioned adjacent the neutron source absorbs at least some of the thermal neutrons so that a region adjacent the neutron absorber has a fast-to-thermal neutron ratio of at least about 15. A coolant in thermal contact with the neutron absorber removes heat from the neutron absorber.

  10. The influence of electron-beam irradiation on the chemical and the structural properties of medical-grade polyurethane

    Science.gov (United States)

    Shin, Sukyoung; Lee, Soonhyouk

    2015-07-01

    Thermo plastic polyurethane (TPU) provides excellent bio-compatibility, flexibility and good irradiation resistance; however, extremely high irradiation doses can alter the structure and the function of macromolecules, resulting in oxidation, chain scission and cross-linking. In this study, the effects of e-beam irradiation on the medical-grade thermo plastic polyurethane were studied. Changes in the chain length and their distribution, as well as changes in the molecular structure were studied. The GPC (gel permeation chromatography) results show that the oxidative decomposition is followed by a decrease in the molecular mass and an increase in polydispersity. This indicates a very inhomogeneous degradation, which is a consequence of the specific course and of the intensity of oxidative degradation. This was confirmed by means of mechanical property measurements. Overall, this study demonstrated that medical-grade TPU was affected by radiation exposure, particularly at high irradiation doses.

  11. Preparation of super absorbent by irradiation polymerization

    International Nuclear Information System (INIS)

    Hua Fengjun; Tan Chunhong; Qian Mengping

    1995-01-01

    A kind of absorbent is prepared by gamma-rays irradiated by reversed-phase suspension polymerization. Drying particles have 1400 (g/g) absorbency in de-ionic water. Effects of reactive conditions, e.g.: dose-rate, dose, monomer concentration, degree of monomer neutralization and crosslinking agents on absorbency in de-ionic water are discussed. The cause of absorbing de-ionic water by polymer is related to its network structure and ionic equilibrium in particle. Accordingly, a suit reactive condition is chosen for preparation of hydro gel spheres

  12. Effects of ordered mesoporous structure and La-doping on the microwave absorbing properties of CoFe2O4

    Science.gov (United States)

    Shang, Tao; Lu, Qingshan; Chao, Luomeng; Qin, Yanli; Yun, Yuehou; Yun, Guohong

    2018-03-01

    Low-density ordered mesoporous CoFe2O4 (Osbnd CFO) and CoLa0.12Fe1.88O4 (Osbnd CLFO) are prepared by nanocasting method using mesoporous silica SBA-15 as a hard-template. The crystal structure, surface chemical state, magnetic properties and electromagnetic parameters are characterized by X-ray diffraction, transmission electron microscopy, N2 adsorption-desorption measurement, X-ray photoelectron spectroscopy, physical property measurement system and vector network analyzer. The results show that all the samples formed a single phase with cubic spinel structure. Meanwhile Osbnd CFO and Osbnd CLFO possess a highly ordered mesostructure. Comparing with particle CoFe2O4 (P-CFO), Osbnd CFO with high specific surface area exhibits lower magnetic saturation (Ms), higher imaginary part of complex permittivity (ε‧‧) and imaginary part of the complex permeability (μ‧‧). The minimum reflection loss (RL) of Osbnd CFO reaches -27.36 dB with a matching thickness of 3.0 mm. The enhancement of the microwave absorbing performances of Osbnd CFO can be mainly attributed to the good impedance matching, high electromagnetic wave attenuation and multiple reflections of electromagnetic wave originated from the ordered mesoporous structure. The Ms of Osbnd CLFO decreases after La3+ doping, while the specific surface area, coercivity value, ε‧‧ and μ‧‧ of Osbnd CLFO increase. The minimum RL of Osbnd CLFO reaches -46.47 dB with a thickness of 3.0 mm, and the effective absorption frequency bandwidth reaches 4.9 GHz.

  13. Development of Bi-Sb-Te ternary alloy with compositionally graded structure

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, A; Ohta, T

    1997-07-01

    Compositionally graded p-type Bi-Sb-Te thermoelectric material was synthesized by PIES (Pulverized and Intermixed Elements Sintering) method. The materials consisted of three segmented regions of different alloy composition, i.e., y = 0.8/0.825/0.9 in (Bi{sub 2}Te{sub 3}){sub 1{minus}y} (Sb{sub 2}Te{sub 3}){sub y} system. It was found that the electrical power output of the compositionally graded material was larger than that of the best single composition material when the temperature difference was the designed value.

  14. An omnidirectional electromagnetic absorber made of metamaterials

    International Nuclear Information System (INIS)

    Cheng Qiang; Cui Tiejun; Jiang Weixiang; Cai Bengeng

    2010-01-01

    In a recent theoretical work by Narimanov and Kildishev (2009 Appl. Phys. Lett. 95 041106) an optical omnidirectional light absorber based on metamaterials was proposed, in which theoretical analysis and numerical simulations showed that all optical waves hitting the absorber are trapped and absorbed. Here we report the first experimental demonstration of an omnidirectional electromagnetic absorber in the microwave frequency. The proposed device is composed of non-resonant and resonant metamaterial structures, which can trap and absorb electromagnetic waves coming from all directions spirally inwards without any reflections due to the local control of electromagnetic fields. It is shown that the absorption rate can reach 99 per cent in the microwave frequency. The all-directional full absorption property makes the device behave like an 'electromagnetic black body', and the wave trapping and absorbing properties simulate, to some extent, an 'electromagnetic black hole.' We expect that such a device could be used as a thermal emitting source and to harvest electromagnetic waves.

  15. A Structural Equation Model of the Writing Process in Typically-Developing Sixth Grade Children

    Science.gov (United States)

    Koutsoftas, Anthony D.; Gray, Shelley

    2013-01-01

    The purpose of this study was to evaluate how sixth grade children planned, translated, and revised written narrative stories using a task reflecting current instructional and assessment practices. A modified version of the Hayes and Flower (1980) writing process model was used as the theoretical framework for the study. Two hundred one…

  16. Hydraulic shock absorbers

    International Nuclear Information System (INIS)

    Thatcher, G.; Davidson, D. F.

    1984-01-01

    A hydraulic shock absorber of the dash pot kind for use with electrically conducting liquid such as sodium, has magnet means for electro magnetically braking a stream of liquid discharged from the cylinder. The shock absorber finds use in a liquid metal cooled nuclear reactor for arresting control rods

  17. Impact of interfacial imperfection on transverse wave in a functionally graded piezoelectric material structure with corrugated boundaries

    Science.gov (United States)

    Kumar Singh, Abhishek; Kumar, Santan; Kumari, Richa

    2018-03-01

    The propagation behavior of Love-type wave in a corrugated functionally graded piezoelectric material layered structure has been taken into account. Concretely, the layered structure incorporates a corrugated functionally graded piezoelectric material layer imperfectly bonded to a functionally graded piezoelectric material half-space. An analytical treatment has been employed to determine the dispersion relation for both cases of electrically open condition and electrically short condition. The phase velocity of the Love-type wave has been computed numerically and its dependence on the wave number has been depicted graphically for a specific type of corrugated boundary surfaces for both said conditions. The crux of the study lies in the fact that the imperfect bonding of the interface, the corrugated boundaries present in the layer, and the material properties of the layer and the half-space strongly influence the phase velocity of the Love-type wave. It can be remarkably noted that the imperfect bonding of the interface reduces the phase velocity of the Love-type wave significantly. As a special case of the problem, it is noticed that the procured dispersion relation for both cases of electrically open and electrically short conditions is in accordance with the classical Love wave equation.

  18. Structural and optical properties of Cu{sub 2}ZnSnS{sub 4} thin film absorbers from ZnS and Cu{sub 3}SnS{sub 4} nanoparticle precursors

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Xianzhong, E-mail: lin.xianzhong@helmholtz-berlin.de [Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, D-14109 Berlin (Germany); Kavalakkatt, Jaison [Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, D-14109 Berlin (Germany); Freie Universität Berlin, Berlin (Germany); Kornhuber, Kai; Levcenko, Sergiu [Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, D-14109 Berlin (Germany); Lux-Steiner, Martha Ch. [Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, D-14109 Berlin (Germany); Freie Universität Berlin, Berlin (Germany); Ennaoui, Ahmed, E-mail: ennaoui@helmholtz-berlin.de [Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, D-14109 Berlin (Germany)

    2013-05-01

    Cu{sub 2}ZnSnS{sub 4} (CZTS) has been considered as an alternative absorber layer to Cu(In,Ga)Se{sub 2} due to its earth abundant and environmentally friendly constituents, optimal direct band gap of 1.4–1.6 eV and high absorption coefficient in the visible range. In this work, we propose a solution-based chemical route for the preparation of CZTS thin film absorbers by spin coating of the precursor inks composed of Cu{sub 3}SnS{sub 4} and ZnS NPs and annealing in Ar/H{sub 2}S atmosphere. X-ray diffraction and Raman spectroscopy were used to characterize the structural properties. The chemical composition was determined by energy dispersive X-ray spectroscopy. Optical properties of the CZTS thin film absorbers were studied by transmission, reflection and photoluminescence spectroscopy.

  19. On the structure of the commutative Z2 graded algebra valued integrable equations

    International Nuclear Information System (INIS)

    Konopelchenko, B.G.

    1980-01-01

    Partial differential equations integrable by the linear matrix spectral problem of arbitrary order are considered for the case that the 'potentials' take their values in the commutative infinte-dimensional Z 2 graded algebra (superalgebra). The general form of the integrable equations and their Baecklund transformations are found. The infinite sets of the integrals of the motion are constructed. The hamiltonian character of the integrable equations is proved. (orig.)

  20. Fe-Substitution for Ni in Misch Metal-Based Superlattice Hydrogen Absorbing Alloys—Part 1. Structural, Hydrogen Storage, and Electrochemical Properties

    Directory of Open Access Journals (Sweden)

    Kwo-Hsiung Young

    2016-11-01

    Full Text Available The effects of Fe partially replacing Ni in a misch metal-based superlattice hydrogen absorbing alloy (HAA were studied. Addition of Fe increases the lattice constants and abundance of the main Ce2Ni7 phase, decreases the NdNi3 phase abundance, and increases the CaCu5 phase when the Fe content is above 2.3 at%. For the gaseous phase hydrogen storage (H-storage, Fe incorporation does not change the storage capacity or equilibrium pressure, but it does decrease the change in both entropy and enthalpy. With regard to electrochemistry, >2.3 at% Fe decreases both the full and high-rate discharge capacities due to the deterioration in both bulk transport (caused by decreased secondary phase abundance and consequent lower synergetic effect and surface electrochemical reaction (caused by the lower volume of the surface metallic Ni inclusions. In a low-temperature environment (−40 °C, although Fe increases the reactive surface area, it also severely hinders the ability of the surface catalytic, leading to a net increase in surface charge-transfer resistance. Even though Fe increases the abundance of the beneficial Ce2Ni7 phase with a trade-off for the relatively unfavorable NdNi3 phase, it also deteriorates the electrochemical performance due to a less active surface. Therefore, further surface treatment methods that are able to increase the surface catalytic ability in Fe-containing superlattice alloys and potentially reveal the positive contributions that Fe provides structurally are worth investigating in the future.

  1. Effect of selenization time on the structural and morphological properties of Cu(In,Ga)Se2 thin films absorber layers using two step growth process

    Science.gov (United States)

    Korir, Peter C.; Dejene, Francis B.

    2018-04-01

    In this work two step growth process was used to prepare Cu(In, Ga)Se2 thin film for solar cell applications. The first step involves deposition of Cu-In-Ga precursor films followed by the selenization process under vacuum using elemental selenium vapor to form Cu(In,Ga)Se2 film. The growth process was done at a fixed temperature of 515 °C for 45, 60 and 90 min to control film thickness and gallium incorporation into the absorber layer film. The X-ray diffraction (XRD) pattern confirms single-phase Cu(In,Ga)Se2 film for all the three samples and no secondary phases were observed. A shift in the diffraction peaks to higher 2θ (2 theta) values is observed for the thin films compared to that of pure CuInSe2. The surface morphology of the resulting film grown for 60 min was characterized by the presence of uniform large grain size particles, which are typical for device quality material. Photoluminescence spectra show the shifting of emission peaks to higher energies for longer duration of selenization attributed to the incorporation of more gallium into the CuInSe2 crystal structure. Electron probe microanalysis (EPMA) revealed a uniform distribution of the elements through the surface of the film. The elemental ratio of Cu/(In + Ga) and Se/Cu + In + Ga strongly depends on the selenization time. The Cu/In + Ga ratio for the 60 min film is 0.88 which is in the range of the values (0.75-0.98) for best solar cell device performances.

  2. PWR burnable absorber evaluation

    International Nuclear Information System (INIS)

    Cacciapouti, R.J.; Weader, R.J.; Malone, J.P.

    1995-01-01

    The purpose of the study was to evaluate the relative neurotic efficiency and fuel cycle cost benefits of PWR burnable absorbers. Establishment of reference low-leakage equilibrium in-core fuel management plans for 12-, 18- and 24-month cycles. Review of the fuel management impact of the integral fuel burnable absorber (IFBA), erbium and gadolinium. Calculation of the U 3 O 8 , UF 6 , SWU, fuel fabrication, and burnable absorber requirements for the defined fuel management plans. Estimation of fuel cycle costs of each fuel management plan at spot market and long-term market fuel prices. Estimation of the comparative savings of the different burnable absorbers in dollar equivalent per kgU of fabricated fuel. (author)

  3. TOMS Absorbing Aerosol Index

    Data.gov (United States)

    Washington University St Louis — TOMS_AI_G is an aerosol related dataset derived from the Total Ozone Monitoring Satellite (TOMS) Sensor. The TOMS aerosol index arises from absorbing aerosols such...

  4. Performance Evaluation of Waterproofing Membrane Systems Subject to the Concrete Joint Load Behavior of Below-Grade Concrete Structures

    Directory of Open Access Journals (Sweden)

    Jaeyoung Song

    2017-11-01

    Full Text Available Below-grade structures such as parking lots, underground subway tunnels, and basements are growing in scale and reaching deeper below-ground levels. In this type of environment, they become subject to higher water pressure. The concrete material of the structures is exposed to wet conditions for longer periods of time, which makes the proper adhesion of waterproofing membranes difficult. Joint movements from increased structural settlement, thermal expansion/shrinkage, and physical loads from external sources (e.g., vehicles make securing durable waterproofing challenging. While ASTM Guides, Korean Codes, and BS Practice Codes on below-grade waterproofing stress the importance of manufacturer specification for quality control, ensuring high quality waterproofing for the ever-changing scale of construction remains a challenge. This study proposes a new evaluation method and criteria which allow for the selection of waterproofing membranes based on specific performance attributes and workmanship. It subjects six different waterproofing membrane systems (installed on dry and wet surface conditioned mortar slab specimens with an artificial joint to different cyclic movement widths to 300 cycles in water to demonstrate that inadequate material properties and workmanship are key causes for leakages.

  5. Jupyter Notebooks as tools for interactive learning of Concepts in Structural Geology and efficient grading of exercises.

    Science.gov (United States)

    Niederau, Jan; Wellmann, Florian; Maersch, Jannik; Urai, Janos

    2017-04-01

    Programming is increasingly recognised an important skill for geoscientists - however, the hurdle to jump into programming for students with little or no experience can be high. We present here teaching concepts on the basis of Jupyter notebooks that combine, in an intuitive way, formatted instruction text with code cells in a single environment. This integration allows for an exposure to programming on several levels: from a complete interactive presentation of content, where students require no or very limited programming experience, to highly complex geoscientific computations. We consider these notebooks therefore as an ideal medium to present computational content to students in the field of geosciences. We show here how we use these notebooks to develop digital documents in Python for undergrad-students, who can then learn about basic concepts in structural geology via self-assessment. Such notebooks comprise concepts such as: stress tensor, strain ellipse, or the mohr circle. Students can interactively change parameters, e.g. by using sliders and immediately see the results. They can further experiment and extend the notebook by writing their own code within the notebook. Jupyter Notebooks for teaching purposes can be provided ready-to-use via online services. That is, students do not need to install additional software on their devices in order to work with the notebooks. We also use Jupyter Notebooks for automatic grading of programming assignments in multiple lectures. An implemented workflow facilitates the generation, distribution of assignments, as well as the final grading. Compared to previous grading methods with a high percentage of repetitive manual grading, the implemented workflow proves to be much more time efficient.

  6. Nano-structure and optical properties (plasmonic) of graded helical square tower-like (terraced) Mn sculptured thin films

    Energy Technology Data Exchange (ETDEWEB)

    Savaloni, Hadi, E-mail: savaloni@khayam.ut.ac.ir [Department of Physics, University of Tehran, North-Kargar Street, Tehran (Iran, Islamic Republic of); Fakharpour, Mahsa [Department of Physics, Islamic Azad University, Science and Research Branch, Tehran (Iran, Islamic Republic of); Siabi-Garjan, Araz [Department of Advanced Technologies, University of Mohaghegh Ardabili, Namin, Ardabil (Iran, Islamic Republic of); Department of Materials Engineering and Nanotechnology, Sabalan University of Advanced Technologies (SUAT), Namin (Iran, Islamic Republic of); Placido, Frank [SUPA and Institute of Thin Films, Sensors and Imaging, University of The West of Scotland, High Street, Paisley (United Kingdom); Babaei, Ferydon [Department of Physics, University of Qom, Qom (Iran, Islamic Republic of)

    2017-01-30

    Highlights: • Graded helical square tower-like terraced sculptured Mn thin films are produced with different number of arms. • XRD, AFM, FESEM and optical analyses as well as theoretical calculations are carried out. • Intensity of Plasmon peaks depend on the polarization, the incident angle, and the distance from the shadowing block. • The presence of defects in these sculptured structures can be predicted by theoretical investigation. • Experimental and theoretical investigations show consistent results. - Abstract: Graded helical square tower-like terraced sculptured Mn thin films (GHSTTS) are produced in three stages with different number of arms using oblique angle deposition together with rotation of substrate holder about its surface normal, plus a shadowing block fixed at the centre of the substrate holder. The structural characterization of the produced samples was obtained using field emission scanning electron microscope (FESEM) and atomic force microscope (AFM). Results showed a structural gradient with distance from the edge of the shadowing block, which in turn is responsible for the decrease in the volume of void fraction and increase of grain size. Plasmon absorption peaks observed in the optical analysis of these nano-structures showed that their wavelength region and intensity depend on the polarization and the incident angle of light, as well as the distance from the edge of the shadowing block. According to our model and discrete dipole approximation (DDA) calculations, when the number of parallel nano-rods of different lengths and radii are increased the peak in the spectrum shifts to shorter wavelengths (blue shift). Also when the diameters of the nano-rods increases (a situation that occurs with increasing film thickness) the results is again a blue shift in the spectrum. The presence of defects in these sculptured structures caused by the shadowing effect is predicted by the theoretical DDA investigation of their optical spectra

  7. Planning and Revising Written Arguments: The Effects of Two Text Structure-Based Interventions on Persuasiveness of 8th-Grade Students' Essays

    Science.gov (United States)

    Midgette, Ekaterina; Haria, Priti

    2016-01-01

    The purpose of the study was to investigate the effects of two comprehensive argumentative writing interventions--Text Structure Instruction (TSI) and Text Structure Revision Instruction (TSRI)--on the eighth-grade students' ability to compose convincing essays that include structural elements of argumentative discourse. Both treatment groups…

  8. Laser grade CaF2 with controllable properties: growing conditions and structural imperfection

    International Nuclear Information System (INIS)

    Mouchovski, J T; Temelkov, K A; Vuchkov, N K; Sabotinov, N V

    2007-01-01

    Optical properties of CaF 2 , grown by a controlled Bridgman-Stockbarger technique, are studied by CuBr and SrBr 2 vapour lasers. Absorption losses are determined as a function of the grown crystal volume, the crystallization front (CF), and the real crystallization rate. It is found that the absorption losses are relatively independent of the transmitted wavelengths in a wide spectral range from the deep ultraviolet (DUV) to the middle infrared (MIR) spectral region and their minimum corresponds to CF positions within the upper half of the adiabatic furnace zone, where the CR reaches a constant value slightly higher than the speed of crucible movement. The crystal quality conforms to laser grade CaF 2 for the DUV, visible and MIR spectral regions and may be controlled efficiently by introducing an appropriate systematic correction in the furnace temperature field, which shifts the CF position

  9. Neuro-fuzzy GMDH based particle swarm optimization for prediction of scour depth at downstream of grade control structures

    Directory of Open Access Journals (Sweden)

    Mohammad Najafzadeh

    2015-03-01

    Full Text Available In the present study, neuro-fuzzy based-group method of data handling (NF-GMDH as an adaptive learning network was utilized to predict the maximum scour depth at the downstream of grade-control structures. The NF-GMDH network was developed using particle swarm optimization (PSO. Effective parameters on the scour depth include sediment size, geometry of weir, and flow characteristics in the upstream and downstream of structure. Training and testing of performances were carried out using non-dimensional variables. Datasets were divided into three series of dataset (DS. The testing results of performances were compared with the gene-expression programming (GEP, evolutionary polynomial regression (EPR model, and conventional techniques. The NF-GMDH-PSO network produced lower error of the scour depth prediction than those obtained using the other models. Also, the effective input parameter on the maximum scour depth was determined through a sensitivity analysis.

  10. GEOMETRICAL OPTIMIZATION OF VEHICLE SHOCK ABSORBERS WITH MR FLUID

    OpenAIRE

    ENGIN, Tahsin; PARLAK, Zekeriya; ŞAHIN, Ismail; ÇALLI, Ismail

    2016-01-01

    Magnetorheological (MR) shock absorber have received remarkable attention in the last decade due to being a potential technology to conduct semi-active control in structures and mechanical systems in order to effectively suppress vibration. To develop performance of MR shock absorbers, optimal design of the dampers should be considered. The present study deals with optimal geometrical modeling of a MR shock absorber. Optimal design of the present shock absorber was carried out by using Taguch...

  11. Energy Absorbing Effectiveness – Different Approaches

    Directory of Open Access Journals (Sweden)

    Kotełko Maria

    2018-03-01

    Full Text Available In the paper the study of different crashworthiness indicators used to evaluate energy absorbing effectiveness of thin-walled energy absorbers is presented. Several different indicators are used to assess an effectiveness of two types of absorbing structures, namely thin-walled prismatic column with flaws and thin-walled prismatic frustum (hollow or foam filled in both cases subjected to axial compressive impact load. The indicators are calculated for different materials and different geometrical parameters. The problem of selection of the most appropriate and general indicators is discussed.

  12. Graphene and Graphene Metamaterials for Terahertz Absorbers

    DEFF Research Database (Denmark)

    Andryieuski, Andrei; Pizzocchero, Filippo; Booth, Tim

    2013-01-01

    Graphene, due to the possibility to tune its conductivity, is the promising material for a range of the terahertz (THz) applications, such as tunable reflectors, absorbers, modulators, filters and polarization converters. Subwavelength structuring of graphene in order to form metamaterials allows...... for even more control over the THz waves. In this poster presentation I will show an elegant way to describe the graphene metamaterials and the design of graphene based absorbers. I will also present our recent experimental results on the graphene absorbers characterization....

  13. Neutron absorbing article

    International Nuclear Information System (INIS)

    Naum, R.G.; Owens, D.P.; Dooher, G.I.

    1979-01-01

    A neutron absorbing article, in flat plate form and suitable for use in a storage rack for spent fuel, includes boron carbide particles, diluent particles and a solid, irreversibly cured phenolic polymer cured to a continuous matrix binding the boron carbide and diluent particles. The total conent of boron carbide and diluent particles is a major proportion of the article and the content of cured phenolic polymer present is a minor proportion. By regulation of the ratio of boron carbide particles to diluent particles, normally within the range of 1:9 and 9:1 and preferably within the range of 1:5 to 5:1, the neutron absorbing activity of the product may be controlled, which facilitates the manufacture of articles of particular absorbing activities best suitable for specific applications

  14. Burnable neutron absorbers

    International Nuclear Information System (INIS)

    Radford, K.C.; Carlson, W.G.

    1983-01-01

    A neutron-absorber body for use in burnable poison rods in a nuclear reactor. The body is composed of a matrix of Al 2 O 3 containing B 4 C, the neutron absorber. Areas of high density polycrystalline Al 2 O 3 particles are predominantly encircled by pores in some of which there are B 4 C particles. This body is produced by initially spray drying a slurry of A1 2 O 3 powder to which a binder has been added. The powder of agglomerated spheres of the A1 2 O 3 with the binder are dry mixed with B 4 C powder. The mixed powder is formed into a green body by isostatic pressure and the green body is sintered. The sintered body is processed to form the neutron-absorber body. In this case the B 4 C particles are separate from the spheres resulting from the spray drying instead of being embedded in the sphere

  15. Frequency Tuning of Vibration Absorber Using Topology Optimization

    Science.gov (United States)

    Harel, Swapnil Subhash

    A tuned mass absorber is a system for reducing the amplitude in one oscillator by coupling it to a second oscillator. If tuned correctly, the maximum amplitude of the first oscillator in response to a periodic driver will be lowered, and much of the vibration will be 'transferred' to the second oscillator. The tuned vibration absorber (TVA) has been utilized for vibration control purposes in many sectors of Civil/Automotive/Aerospace Engineering for many decades since its inception. Time and again we come across a situation in which a vibratory system is required to run near resonance. In the past, approaches have been made to design such auxiliary spring mass tuned absorbers for the safety of the structures. This research focuses on the development and optimization of continuously tuned mass absorbers as a substitute to the discretely tuned mass absorbers (spring- mass system). After conducting the study of structural behavior, the boundary condition and frequency to which the absorber is to be tuned are determined. The Modal analysis approach is used to determine mode shapes and frequencies. The absorber is designed and optimized using the topology optimization tool, which simultaneously designs, optimizes and tunes the absorber to the desired frequency. The tuned, optimized absorber, after post processing, is attached to the target structure. The number of the absorbers are increased to amplify bandwidth and thereby upgrade the safety of structure for a wide range of frequency. The frequency response analysis is carried out using various combinations of structure and number of absorber cell.

  16. Novel, Functionally Graded PIP Coating System for Hot Structures, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposal addresses some of the most challenging materials issues with respect to Hot Structures, very high temperature, up to 4000 degrees F, applications. The...

  17. Relationship of pass/fail grading and curriculum structure with well-being among preclinical medical students: a multi-institutional study.

    Science.gov (United States)

    Reed, Darcy A; Shanafelt, Tait D; Satele, Daniel W; Power, David V; Eacker, Anne; Harper, William; Moutier, Christine; Durning, Steven; Massie, F Stanford; Thomas, Matthew R; Sloan, Jeff A; Dyrbye, Liselotte N

    2011-11-01

    Psychological distress is common among medical students. Curriculum structure and grading scales are modifiable learning environment factors that may influence student well-being. The authors sought to examine relationships among curriculum structures, grading scales, and student well-being. The authors surveyed 2,056 first- and second-year medical students at seven U.S. medical schools in 2007. They used the Perceived Stress Scale, Maslach Burnout Inventory, and Medical Outcomes Study Short Form (SF-8) to measure stress, burnout, and quality of life, respectively. They measured curriculum structure using hours spent in didactic, clinical, and testing experiences. Grading scales were categorized as two categories (pass/fail) versus three or more categories (e.g., honors/pass/fail). Of the 2,056 students, 1,192 (58%) responded. In multivariate analyses, students in schools using grading scales with three or more categories had higher levels of stress (beta 2.65; 95% CI 1.54-3.76, Pstudents in schools using pass/fail grading. There were no relationships between time spent in didactic and clinical experiences and well-being. How students are evaluated has a greater impact than other aspects of curriculum structure on their well-being. Curricular reform intended to enhance student well-being should incorporate pass/fail grading.

  18. Mechanical shock absorber

    International Nuclear Information System (INIS)

    Vrillon, Bernard.

    1973-01-01

    The mechanical shock absorber described is made of a constant thickness plate pierced with circular holes regularly distributed in such a manner that for all the directions along which the strain is applied during the shock, the same section of the substance forming the plate is achieved. The shock absorber is made in a metal standing up to extensive deformation before breaking, selected from a group comprising mild steels and austenitic stainless steels. This apparatus is used for handling pots of fast neutron reactor fuel elements [fr

  19. Neutron absorbing article

    International Nuclear Information System (INIS)

    Naum, R.G.; Owens, D.P.; Dooker, G.I.

    1981-01-01

    A neutron-absorbing article suitable for use in spent fuel racks is described. It comprises boron carbide particles, diluent particles, and a phenolic polymer cured to a continuous matrix. The diluent may be silicon carbide, graphite, amorphous carbon, alumina, or silica. The combined boron carbide-diluent phase contains no more than 2 percent B 2 O 3 , and the neutron-absorbing article contains from 20 to 40 percent phenol resin. The ratio of boron carbide to diluent particles is in the range 1:9 to 9:1

  20. Intrinsic hierarchical structural imperfections in a natural ceramic of bivalve shell with distinctly graded properties.

    Science.gov (United States)

    Jiao, Da; Liu, Zengqian; Zhang, Zhenjun; Zhang, Zhefeng

    2015-07-22

    Despite the extensive investigation on the structure of natural biological materials, insufficient attention has been paid to the structural imperfections by which the mechanical properties of synthetic materials are dominated. In this study, the structure of bivalve Saxidomus purpuratus shell has been systematically characterized quantitatively on multiple length scales from millimeter to sub-nanometer. It is revealed that hierarchical imperfections are intrinsically involved in the crossed-lamellar structure of the shell despite its periodically packed platelets. In particular, various favorable characters which are always pursued in synthetic materials, e.g. nanotwins and low-angle misorientations, have been incorporated herein. The possible contributions of these imperfections to mechanical properties are further discussed. It is suggested that the imperfections may serve as structural adaptations, rather than detrimental defects in the real sense, to help improve the mechanical properties of natural biological materials. This study may aid in understanding the optimizing strategies of structure and properties designed by nature, and accordingly, provide inspiration for the design of synthetic materials.

  1. Low Absorbance Measurements

    Science.gov (United States)

    Harris, T. D.; Williams, A. M.

    1983-10-01

    The application of low absorption measurements to dilute solute determination requires specific instrumental characteristics. The use of laser intracavity absorption and thermal lens calorimetry to measure concentration is shown. The specific operating parameters that determine sensitivity are delineated along with the limits different measurement strategies impose. Finally areas of improvement in components that would result in improve sensitivity, accuracy, and reliability are discussed. During the past decade, a large number of methods have been developed for measuring the light absorbed by transparent materials. These include measurements on gases, liquids, and solids. The activity has been prompted by a variety of applications and a similar variety of disciplines. In Table 1 some representative examples of these methods is shown along with their published detection limits.1 It is clear that extraordinarily small absorbances can be measured. Most of the methods can be conveniently divided into two groups. These groups are those that measure the transmission of the sample and those that measure the light absorbed by the sample. The light absorbed methods are calorimetric in character. The advantages and disadvantages of each method varies depending on the principal application for which they were developed. The most prevalent motivation has been to characterize the bulk optical properties of transparent materials. Two examples are the development of extremely transparent glasses for use as fiber optic materials and the development of substrates for high power laser operation.

  2. Packaging & Other Structures. Stuff That Works! A Technology Curriculum for the Elementary Grades.

    Science.gov (United States)

    Benenson, Gary

    This book explores all kinds of packaging materials including bags, boxes, etc. and how they are used to protect and display products. Contents are divided into six chapters: (1) "Appetizers" includes activities that can be done individually to become familiar with the topic of packaging and structures; (2) "Concepts" provides…

  3. Ultrasound assessment for grading structural tendon changes in supraspinatus tendinopathy: an inter-rater reliability study

    DEFF Research Database (Denmark)

    Ingwersen, Kim Gordon; Hjarbæk, John; Eshøj, Henrik

    2016-01-01

    Aim To evaluate the inter-rater reliability of measuring structural changes in the tendon of patients, clinically diagnosed with supraspinatus tendinopathy (cases) and healthy participants (controls), on ultrasound (US) images captured by standardised procedures. Methods A total of 40 participant...

  4. Adaptive Piezoelectric Absorber for Active Vibration Control

    Directory of Open Access Journals (Sweden)

    Sven Herold

    2016-02-01

    Full Text Available Passive vibration control solutions are often limited to working reliably at one design point. Especially applied to lightweight structures, which tend to have unwanted vibration, active vibration control approaches can outperform passive solutions. To generate dynamic forces in a narrow frequency band, passive single-degree-of-freedom oscillators are frequently used as vibration absorbers and neutralizers. In order to respond to changes in system properties and/or the frequency of excitation forces, in this work, adaptive vibration compensation by a tunable piezoelectric vibration absorber is investigated. A special design containing piezoelectric stack actuators is used to cover a large tuning range for the natural frequency of the adaptive vibration absorber, while also the utilization as an active dynamic inertial mass actuator for active control concepts is possible, which can help to implement a broadband vibration control system. An analytical model is set up to derive general design rules for the system. An absorber prototype is set up and validated experimentally for both use cases of an adaptive vibration absorber and inertial mass actuator. Finally, the adaptive vibration control system is installed and tested with a basic truss structure in the laboratory, using both the possibility to adjust the properties of the absorber and active control.

  5. Relationships between grade determining properties of Spanish scots and laricio pine structural timber

    Directory of Open Access Journals (Sweden)

    Fernández-Golfín, J. I.

    2003-06-01

    Full Text Available In a. sample made up of 3312 boards of scots pine (pinus sylvestris and 3318 boards of laricio pine pinus nigra Van Saltzmannii, both of Spanish provenance, and ranging in size from 100x40x2500 mm to 200x70x4500 mm, previously tested in accordance with the procedure set forth in UNE EN 408 standard, the relationships between the grade determining properties considered in the UNE EN 338 standard (bending strength, global and local modulus of elasticity in bending, density are studied. In addition to these variables, the modulus of elasticity was also considered, calculated by means of the measuring of the transmission speed of an ultrasonic pulse generated by a Sylvatest device. The global modulus of elasticity calculated by measuring the deformation at the neutral axis seems to be the best predictor of the ultimate bending strength, while the local modulus of elasticity proves to be difficult to obtain, and has a lower predictive quality, and so its elimination is suggested. The need to consider one single testing procedure to determine the global modulus of elasticity is also analyzed, along with the convenience of carrying out further studies regarding the use of ultrasonic techniques in order to predict the modulus of elasticity, due to the fact that the systems available are not sufficiently precise.

    En una muestra compuesta por 3.312 piezas de madera aserrada de pino laricio (pimis nigra y 3.318 piezas de pino silvestre (pinus sylvestris de procedencia española y con dimensiones que varían entre 100x40x2.500 mm y 200x70x4.500 mm, previamente ensayada a flexión de acuerdo con el procedimiento descrito en la norma UNE EN 408, se analizan las relaciones existentes entre las propiedades indicadoras establecidas en la norma UNE EN 338 (resistencia última a flexión, módulos de elasticidad global y local en flexión, densidad. Adicionalmente a estas variables se determinó también el módulo de elasticidad obtenido mediante la medici

  6. The effects of temperature and diet on age grading and population age structure determination in Drosophila.

    Science.gov (United States)

    Aw, Wen C; Ballard, J William O

    2013-10-01

    The age structure of natural population is of interest in physiological, life history and ecological studies but it is often difficult to determine. One methodological problem is that samples may need to be invasively sampled preventing subsequent taxonomic curation. A second problem is that it can be very expensive to accurately determine the age structure of given population because large sample sizes are often necessary. In this study, we test the effects of temperature (17 °C, 23 °C and 26 °C) and diet (standard cornmeal and low calorie diet) on the accuracy of the non-invasive, inexpensive and high throughput near-infrared spectroscopy (NIRS) technique to determine the age of Drosophila flies. Composite and simplified calibration models were developed for each sex. Independent sets for each temperature and diet treatments with flies not involved in calibration model were then used to validate the accuracy of the calibration models. The composite NIRS calibration model was generated by including flies reared under all temperatures and diets. This approach permits rapid age measurement and age structure determination in large population of flies as less than or equal to 9 days, or more than 9 days old with 85-97% and 64-99% accuracy, respectively. The simplified calibration models were generated by including flies reared at 23 °C on standard diet. Low accuracy rates were observed when simplified calibration models were used to identify (a) Drosophila reared at 17 °C and 26 °C and (b) 23 °C with low calorie diet. These results strongly suggest that appropriate calibration models need to be developed in the laboratory before this technique can be reliably used in field. These calibration models should include the major environmental variables that change across space and time in the particular natural population to be studied. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. GaSe:Cd semiconductor - own oxide nanolamellar structures as a selective gas absorber; Structuri nanolamelare semiconductor GaSe:Cd - oxid propriu ca adsorbant selectiv de gaze

    Energy Technology Data Exchange (ETDEWEB)

    Dmitroglo, Liliana; Evtodiev, Igor; Lazar, Gheorghe [Univ. de Stat din Moldova, Chisinau (Moldova, Republic of); Caraman, Iuliana [Univ. ' Vasile Alecsandri' din Bacau, Bacau (Romania); Dafinei, Adrian [Universitatea din Bucuresti, Bucuresti (Romania)

    2012-07-15

    A lamella with the thickness of 10-300 {mu}m and C6 axis oriented perpendicular to (001) surface were obtained from {epsilon}-GaSe single crystals grown by Bridgman method. By a heat treatment at the temperature of 450-580 degrees Celsius the lamella surfaces were coated with the own nanostructured (Ga{sub 2}O{sub 3}) oxide. The absorption of polar molecules from the (H{sub 2}O, CO, CON) atmosphere was studied by using absorptional IR spectroscopy. These molecules absorption bands and optical transparency dependence on the absorbed molecules concentration were determined. (authors)

  8. Mechanical characterization of sawn timber for structural use, graded visually in accordance with Spanish standard UNE 56544

    Directory of Open Access Journals (Sweden)

    Fernández-Golfín, J. I.

    1998-12-01

    Full Text Available The employment of timber in structures in Spain was hurting of the nonexistence of accepted calculation procedures. The recent adoption and publication of the Eurocode 5 compels to the employment of the characteristic values of the material in the structural calculation by the method of the finite elements. This report sets forth the results of the experiments carried out at INIA's Forest Research Centre (CIFOR-INIA regarding the mechanical characterization of sawn timber of size 150x50x3.000 mm and the structural uses of "Pinus sylvestris, P. radiata and P. pinaster" from different Spanish provenances. The characteristic values and strength classes corresponding with the grades stated in the Spanish standard UNE 56544 are also provided. The report compares and analyses the results of these experiments, and presents the conclusions drawn from the different behaviour shown by the four species. An analysis of the Spanish standard for the visual grading of structural timber is carried out on the three species.

    El empleo de la madera en la construcción en España adolecía de la inexistencia de procedimientos de cálculo normalizados. La reciente adopción y publicación del Eurocódigo 5 obliga al empleo de los valores característicos del material en el cálculo estructural de la madera por el método de los elementos finitos. Se presentan los resultados de la caracterización mecánica de la madera aserrada de tamaño (150x50x3.000 mm y usos estructurales de "Pinus sylvestris, P. radiata y P. pinaster" de diferentes procedencias, llevada a cabo en el Centro de Investigación Forestal (CIFOR del INIA. Se aportan los valores característicos y clases de resistencia que corresponden a las clases de calidad definidas en la norma UNE 56544. Se efectúa una comparación y análisis de los resultados obtenidos, extrayendo conclusiones respecto del diferente comportamiento observado para las cuatro especies. Se analiza la adecuación de la

  9. Adjustable Shock Absorbers

    OpenAIRE

    Adamiec, Radek

    2012-01-01

    Bakalářská práce obsahuje přehled používaných tlumičů osobních automobilů, závodních automobilů a motocyklů. Jsou zde popsány systémy t lumením, konstrukce tlumičů a vidlic používaných u motocyklů. Dále je zde přehled prvků používaných u podvozků automobilů. This bachelor´s thesis contains the survey of the shock absorbers of passenger cars, racing cars and motorcycles. Are described damping systems, the design used shock absorbers and forks for motorcycles. Then there is the list of the e...

  10. To curve or not to curve? The effect of college science grading policies on implicit theories of intelligence, perceived classroom goal structures, and self-efficacy

    Science.gov (United States)

    Haley, James M.

    There is currently a shortage of students graduating with STEM (science, technology, engineering, or mathematics) degrees, particularly women and students of color. Approximately half of students who begin a STEM major eventually switch out. Many switchers cite the competitiveness, grading curves, and weed-out culture of introductory STEM classes as reasons for the switch. Variables known to influence resilience include a student's implicit theory of intelligence and achievement goal orientation. Incremental theory (belief that intelligence is malleable) and mastery goals (pursuit of increased competence) are more adaptive in challenging classroom contexts. This dissertation investigates the role that college science grading policies and messages about the importance of effort play in shaping both implicit theories and achievement goal orientation. College students (N = 425) were randomly assigned to read one of three grading scenarios: (1) a "mastery" scenario, which used criterion-referenced grading, permitted tests to be retaken, and included a strong effort message; (2) a "norm" scenario, which used norm-referenced grading (grading on the curve); or (3) an "effort" scenario, which combined a strong effort message with the norm-referenced policies. The dependent variables included implicit theories of intelligence, perceived classroom goal structure, and self-efficacy. A different sample of students (N = 15) were randomly assigned a scenario to read, asked to verbalize their thoughts, and responded to questions in a semi-structured interview. Results showed that students reading the mastery scenario were more likely to endorse an incremental theory of intelligence, perceived greater mastery goal structure, and had higher self-efficacy. The effort message had no effect on self-efficacy, implicit theory, and most of the goal structure measures. The interviews revealed that it was the retake policy in the mastery scenario and the competitive atmosphere in the norm

  11. Aluminum alloy excellent in neutron absorbing performance

    International Nuclear Information System (INIS)

    Iida, Tetsuya; Tamamura, Tadao; Morimoto, Hiroyuki; Ouchi, Ken-ichiro.

    1987-01-01

    Purpose: To obtain structural materials made of aluminum alloys having favorable neutron absorbing performance and excellent in the performance as structural materials such as processability and strength. Constitution: Powder of Gd 2 O 3 as a gadolinium compound or metal gadolinium is uniformly mixed with the powder of aluminum or aluminum alloy. The amount of the gadolinium compound added is set to 0.1 - 30 % by weight. No sufficient neutron absorbing performance can be obtained if it is less than 0.1 % by weight, whereas the processability and mechanical property of the alloy are degraded if it exceeds 30 % by weight. Further, the grain size is set to less about 50 μm. Further, since the neutron absorbing performance varies greatly if the aluminum powder size exceeds 100 μm, the diameter is set to less than about 100 μm. These mixtures are molded in a hot press. This enables to obtain aimed structural materials. (Takahashi, M.)

  12. Kinetic energy absorbing pad

    International Nuclear Information System (INIS)

    Bricmont, R.J.; Hamilton, P.A.; Ming Long Ting, R.

    1981-01-01

    Reactors, fuel processing plants etc incorporate pipes and conduits for fluids under high pressure. Fractures, particularly adjacent to conduit elbows, produce a jet of liquid which whips the broken conduit at an extremely high velocity. An enormous impact load would be applied to any stationary object in the conduit's path. The design of cellular, corrugated metal impact pads to absorb the kinetic energy of the high velocity conduits is given. (U.K.)

  13. Absorbable and biodegradable polymers

    CERN Document Server

    Shalaby, Shalaby W

    2003-01-01

    INTRODUCTION NOTES: Absorbable/Biodegradable Polymers: Technology Evolution. DEVELOPMENT AND APPLICATIONOF NEW SYSTEMS: Segmented Copolyesters with Prolonged Strength Retention Profiles. Polyaxial Crystalline Fiber-Forming Copolyester. Polyethylene Glycol-Based Copolyesters. Cyanoacrylate-Based Systems as Tissue Adhesives. Chitosan-Based Systems. Hyaluronic Acid-Based Systems. DEVELOPMENTS IN PREPARATIVE, PROCESSING, AND EVALUATION METHODS: New Approaches to the Synthesis of Crystalline. Fiber-Forming Aliphatic Copolyesters. Advances in Morphological Development to Tailor the Performance of Me

  14. Resistive foil edge grading for accelerator and other high voltage structures

    Science.gov (United States)

    Caporaso, George J.; Sampayan, Stephen F.; Sanders, David M.

    2014-06-10

    In a structure or device having a pair of electrical conductors separated by an insulator across which a voltage is placed, resistive layers are formed around the conductors to force the electric potential within the insulator to distribute more uniformly so as to decrease or eliminate electric field enhancement at the conductor edges. This is done by utilizing the properties of resistive layers to allow the voltage on the electrode to diffuse outwards, reducing the field stress at the conductor edge. Preferably, the resistive layer has a tapered resistivity, with a lower resistivity adjacent to the conductor and a higher resistivity away from the conductor. Generally, a resistive path across the insulator is provided, preferably by providing a resistive region in the bulk of the insulator, with the resistive layer extending over the resistive region.

  15. Burnable neutron absorbers

    International Nuclear Information System (INIS)

    Radford, K.C.; Carlson, W.G.

    1985-01-01

    This patent deals with the fabrication of pellets for neutron absorber rods. Such a pellet includes a matrix of a refractory material which may be aluminum or zirconium oxide, and a burnable poison distributed throughout the matrix. The neutron absorber material may consist of one or more elements or compounds of the metals boron, gadolinium, samarium, cadmium, europium, hafnium, dysprosium and indium. The method of fabricating pellets of these materials outlined in this patent is designed to produce pores or voids in the pellets that can be used to take up the expansion of the burnable poison and to absorb the helium gas generated. In the practice of this invention a slurry of Al 2 O 3 is produced. A hard binder is added and the slurry and binder are spray dried. This powder is mixed with dry B 4 C powder, forming a homogeneous mixture. This mixture is pressed into green tubes which are then sintered. During sintering the binder volatilizes leaving a ceramic with nearly spherical high-density regions of

  16. Structure Optimization of 21,23-Core-Modified Porphyrins Absorbing Long-Wavelength Light as Potential Photosensitizers Against Breast Cancer Cells

    National Research Council Canada - National Science Library

    Detty, Michael R

    2007-01-01

    .... The structures of two derivatives were determined unambiguously be x-ray crystallography including the structure of a cis-ABCC meso-substituted derivative and the structure of a cis-AB disubstituted derivative...

  17. Explosive welding method for manufacturing ITER-grade 316L(N)/CuCrZr hollow structural member

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Rui, E-mail: mr9980@163.com [PLA University of Science and Technology, Nanjing 210007 (China); Wang, Yaohua [PLA University of Science and Technology, Nanjing 210007 (China); Wu, Jihong [Southwestern Institute of Physics, Chengdu 610041 (China); Duan, Mianjun [PLA University of Science and Technology, Nanjing 210007 (China)

    2014-12-15

    Highlights: • Develop a new explosive welding method to fabricate the cooling channel of FW. • Utilize effective energy model to accurately calculate optimal welding parameters. • Provide an efficient way for manufacturing high-ductility hollow structural member. - Abstract: In this study, a new explosive welding method provided an effective way for manufacturing ITER-grade 316L(N)/CuCrZr hollow structural member. The welding parameters (stand-off distance and explosion rate) were calculated respectively using equivalent frontal collision wave model and effective energy model. The welded samples were subject to two step heat treatment cycles (solution annealing and aging). Optical microscopy (OM) and scanning electron microscopy (SEM) were utilized to analyze the microstructure of bonding interface. The mechanical properties of the welded samples were evaluated through microhardness test and tensile test. Moreover, the sealing property of the welded specimens was measured through helium leak test. Microstructural analysis showed that the welded sample using effective energy model had an ideal wavy interface. The results of microhardness test revealed an increase in hardness for both sides near to the bonding interface. And the hardening phenomenon of interface region disappeared after the solution annealing. SEM observation indicated that the samples with the post heat treatments exhibited a ductile fracture with dimple features after tensile test. After the specimens undergo aging strengthening, there was an obvious increase in the strength for all specimens. The helium leak test results have proven that the welded specimens are soundness.

  18. Structuring and calorie control of bakery products by templating batter with ultra melt-resistant food-grade hydrogel beads.

    Science.gov (United States)

    Thompson, Benjamin R; Horozov, Tommy S; Stoyanov, Simeon D; Paunov, Vesselin N

    2017-08-01

    We report the use of a temperature insensitive, food-grade hydrogel to reduce the caloric density of pancakes that were prepared at temperatures much higher than the boiling point of water. This cheap, facile method utilises a mixed agar-methylcellulose hydrogel, which was blended to produce a slurry of hydrogel microbeads. The pancake batter was mixed with a controlled volume percentage of slurry of hydrogel beads and cooked. From bomb calorimetry experiments, the composites were found to have a reduced caloric density that reflects the volume percentage of hydrogel beads mixed with the batter. Using this procedure, we were able to reduce the caloric density of pancakes by up to 23 ± 3% when the volume percentage of hydrogel beads initially used was 25%. The method is not limited to pancakes and could potentially be applied to various other food products. The structure and morphology of the freeze-dried pancakes and pancake-hydrogel composites were investigated and pores of a similar size to the hydrogel beads were found, confirming that the gel beads maintained their structure during the cooking process. There is scope for further development of this method by the encapsulation of nutritionally beneficial or flavour enhancing ingredients within the hydrogel beads.

  19. Absorbed Energy in Ship Collisions and Grounding

    DEFF Research Database (Denmark)

    Pedersen, Preben Terndrup; Zhang, Shengming

    1998-01-01

    is that the absorbed energy does not depend on the arrangement of the structure, the material properties, and the damage mode.The purpose of the present paper is to establish a new simple relation between the absorbed energy and the destroyed material volume, which can be used as a design tool for analysis of ship...... collisions and grounding. The developed expressions reflect the structural arrangement, the material properties and different damage patterns.The present method is validated against a large number of existing experimental results and detailed numerical simulation results. Applications to full-sale ship...

  20. Pharmaceutical grade phyllosilicate dispersions: the influence of shear history on floc structure.

    Science.gov (United States)

    Viseras, C; Meeten, G H; Lopez-Galindo, A

    1999-05-10

    The effect of mixing conditions on the flow curves of some clay-water dispersions was studied. Two Spanish fibrous phyllosilicates (sepiolite from Vicálvaro and palygorskite from Turón) and a commercial bentonite (Bentopharm Copyright, UK) were selected as model clays. The disperse systems were made up using a rotor-stator mixer working at two different mixing rates (1000 and 8000 rpm), for periods of 1 and 10 min. Rheological measurements were taken and the corresponding flow curves obtained immediately after interposition and then after a period of 24 h under low shear caused by a roller apparatus. Aqueous sepiolite dispersions showed the highest viscosity and were easily interposed, whereas palygorskite dispersions were more difficult to obtain, resulting in low to medium viscosity gels. Bentonite dispersions provided medium viscosity systems, which greatly increased their viscosity after the low shear treatment (as a result of swelling), whereas the viscosity of the fibrous clays stayed at approximately the same values or even decreased. A linear relation was found between mixing energy and apparent viscosity in the bentonite systems, while apparent viscosity in the sepiolite samples was related to mixing power, with minor influence of mixing times. All the systems studied had thixotropic behaviour, changing from clearly positive to even negative thixotropy in some palygorskite systems. Finally, we studied the effect of drastic pH changes on the system structure. Results showed that rheological properties were highly sensitive to pH in the fibrous dispersions, but less sensitive behaviour was found in the laminar clay systems. Copyright.

  1. Emolabeling increases healthy food choices among grade school children in a structured grocery aisle setting.

    Science.gov (United States)

    Privitera, Gregory J; Phillips, Taylor E; Zuraikat, Faris M; Paque, Robert

    2015-09-01

    Health literacy, the ability to acquire health-related knowledge and make appropriate health-related decisions, is regarded as a key barrier to meaningfully convey health information to children and can impact food choice. Emolabeling is an image-based labeling strategy aimed at addressing this problem by conveying health information using emotional correlates of health using emoticons (happy = healthy; sad = not healthy). To test the utility of such a method to promote healthy food choices among children, 64 children (59% girls, foods in each of 2 aisles structured to mimic a grocery aisle - there were 12 identical foods placed in the same location in each aisle with half being low calorie and half high calorie snacks. Foods were emolabeled in one aisle; no emolabels were used in the other aisle; the order that children were brought in each aisle was counterbalanced. Results showed that adding emolabels increased the number (M ± SD) of healthy foods chosen (3.6 ± 0.7 with vs. 2.3 ± 1.1 without emolabels present [95% CI 1.0, 1.5], R(2) = .67) and reduced the total calories (M ± SD) of foods chosen (193.5 ± 88.5 Cal with vs. 374.3 ± 152.6 Cal without emolabels present [95% CI -212.6, -149.0], R(2) = .70). Hence, adding emolabels was associated with healthier food choices among children, thereby demonstrating one possible strategy to effectively overcome health literacy barriers at these ages. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Shock absorber in Ignalina NPP

    International Nuclear Information System (INIS)

    Bulavas, A.; Muralis, J.

    1996-09-01

    Theoretical calculation and experimental analysis of models of shock absorber in Ignalina NPP is presented. The results obtained from the investigation with model of shock absorber coincide with the theoretical calculation. (author). 2 figs., 3 refs

  3. Absorber for terahertz radiation management

    Science.gov (United States)

    Biallas, George Herman; Apeldoorn, Cornelis; Williams, Gwyn P.; Benson, Stephen V.; Shinn, Michelle D.; Heckman, John D.

    2015-12-08

    A method and apparatus for minimizing the degradation of power in a free electron laser (FEL) generating terahertz (THz) radiation. The method includes inserting an absorber ring in the FEL beam path for absorbing any irregular THz radiation and thus minimizes the degradation of downstream optics and the resulting degradation of the FEL output power. The absorber ring includes an upstream side, a downstream side, and a plurality of wedges spaced radially around the absorber ring. The wedges form a scallop-like feature on the innermost edges of the absorber ring that acts as an apodizer, stopping diffractive focusing of the THz radiation that is not intercepted by the absorber. Spacing between the scallop-like features and the shape of the features approximates the Bartlett apodization function. The absorber ring provides a smooth intensity distribution, rather than one that is peaked on-center, thereby eliminating minor distortion downstream of the absorber.

  4. Corrosion resistant neutron absorbing coatings

    Science.gov (United States)

    Choi, Jor-Shan [El Cerrito, CA; Farmer, Joseph C [Tracy, CA; Lee, Chuck K [Hayward, CA; Walker, Jeffrey [Gaithersburg, MD; Russell, Paige [Las Vegas, NV; Kirkwood, Jon [Saint Leonard, MD; Yang, Nancy [Lafayette, CA; Champagne, Victor [Oxford, PA

    2012-05-29

    A method of forming a corrosion resistant neutron absorbing coating comprising the steps of spray or deposition or sputtering or welding processing to form a composite material made of a spray or deposition or sputtering or welding material, and a neutron absorbing material. Also a corrosion resistant neutron absorbing coating comprising a composite material made of a spray or deposition or sputtering or welding material, and a neutron absorbing material.

  5. Feynman Integrals with Absorbing Boundaries

    OpenAIRE

    Marchewka, A.; Schuss, Z.

    1997-01-01

    We propose a formulation of an absorbing boundary for a quantum particle. The formulation is based on a Feynman-type integral over trajectories that are confined to the non-absorbing region. Trajectories that reach the absorbing wall are discounted from the population of the surviving trajectories with a certain weighting factor. Under the assumption that absorbed trajectories do not interfere with the surviving trajectories, we obtain a time dependent absorption law. Two examples are worked ...

  6. Solar radiation absorbing material

    Science.gov (United States)

    Googin, John M.; Schmitt, Charles R.; Schreyer, James M.; Whitehead, Harlan D.

    1977-01-01

    Solar energy absorbing means in solar collectors are provided by a solar selective carbon surface. A solar selective carbon surface is a microporous carbon surface having pores within the range of 0.2 to 2 micrometers. Such a surface is provided in a microporous carbon article by controlling the pore size. A thermally conductive substrate is provided with a solar selective surface by adhering an array of carbon particles in a suitable binder to the substrate, a majority of said particles having diameters within the range of about 0.2-10 microns.

  7. Identifying the perfect absorption of metamaterial absorbers

    Science.gov (United States)

    Duan, G.; Schalch, J.; Zhao, X.; Zhang, J.; Averitt, R. D.; Zhang, X.

    2018-01-01

    We present a detailed analysis of the conditions that result in unity absorption in metamaterial absorbers to guide the design and optimization of this important class of functional electromagnetic composites. Multilayer absorbers consisting of a metamaterial layer, dielectric spacer, and ground plane are specifically considered. Using interference theory, the dielectric spacer thickness and resonant frequency for unity absorption can be numerically determined from the functional dependence of the relative phase shift of the total reflection. Further, using transmission line theory in combination with interference theory we obtain analytical expressions for the unity absorption resonance frequency and corresponding spacer layer thickness in terms of the bare resonant frequency of the metamaterial layer and metallic and dielectric losses within the absorber structure. These simple expressions reveal a redshift of the unity absorption frequency with increasing loss that, in turn, necessitates an increase in the thickness of the dielectric spacer. The results of our analysis are experimentally confirmed by performing reflection-based terahertz time-domain spectroscopy on fabricated absorber structures covering a range of dielectric spacer thicknesses with careful control of the loss accomplished through water absorption in a semiporous polyimide dielectric spacer. Our findings can be widely applied to guide the design and optimization of the metamaterial absorbers and sensors.

  8. Analysis of Problems Posed by Sixth-Grade Middle School Students for the Addition of Fractions in Terms of Semantic Structures

    Science.gov (United States)

    Kar, Tugrul

    2015-01-01

    This study aimed to investigate how the semantic structures of problems posed by sixth-grade middle school students for the addition of fractions affect their problem-posing performance. The students were presented with symbolic operations involving the addition of fractions and asked to pose two different problems related to daily-life situations…

  9. Factor Structure of the Reactive-Proactive Aggression Questionnaire in Turkish Children and Gender, Grade-Level, and Socioeconomic Status Differences in Reactive and Proactive Aggression

    Science.gov (United States)

    Uz Bas, Asli; Yurdabakan, Irfan

    2012-01-01

    The present study aimed to evaluate the factor structure of the Reactive-Proactive Aggression Questionnaire (RPQ) with Turkish children, and to investigate gender, grade-level, and socioeconomic status (SES) differences in reactive and proactive aggression. Participants consisted of 1,081 Turkish children (544 boys and 537 girls) aged 9 to 14…

  10. Neutron Absorbing Ability Variation in Neutron Absorbing Material Caused by the Neutron Irradiation in Spent Fuel Storage Facility

    Energy Technology Data Exchange (ETDEWEB)

    Sohn, Hee Dong; Han, Seul Gi; Lee, Sang Dong; Kim, Ki Hong; Ryu, Eag Hyang; Park, Hwa Gyu [Doosan Heavy Industries and Construction, Changwon (Korea, Republic of)

    2014-10-15

    In spent fuel storage facility like high density spent fuel storage racks and dry storage casks, spent fuels are stored with neutron absorbing materials installed as a part of those facilities, and they are used for absorbing neutrons emitted from spent fuels. Usually structural material with neutron absorbing material of racks and casks are located around spent fuels, so it is irradiated by neutrons for long time. Neutron absorbing ability could be changed by the variation of nuclide composition in neutron absorbing material caused by the irradiation of neutrons. So, neutron absorbing materials are continuously faced with spent fuels with boric acid solution or inert gas environment. Major nuclides in neutron absorbing material are Al{sup 27}, C{sup 12}, B{sup 11}, B{sup 10} and they are changed to numerous other ones as radioactive decay or neutron absorption reaction. The B{sup 10} content in neutron absorbing material dominates the neutron absorbing ability, so, the variation of nuclide composition including the decrease of B{sup 10} content is the critical factor on neutron absorbing ability. In this study, neutron flux in spent fuel, the activation of neutron absorbing material and the variation of nuclide composition are calculated. And, the minimum neutron flux causing the decrease of B{sup 10} content is calculated in spent fuel storage facility. Finally, the variation of neutron multiplication factor is identified according to the one of B{sup 10} content in neutron absorbing material. The minimum neutron flux to impact the neutron absorbing ability is 10{sup 10} order, however, usual neutron flux from spent fuel is 10{sup 8} order. Therefore, even though neutron absorbing material is irradiated for over 40 years, B{sup 10} content is little decreased, so, initial neutron absorbing ability could be kept continuously.

  11. Effects of grade control structures on fish passage, biological assemblages, and hydraulic environments in western Iowa streams: a multidisciplinary review

    Science.gov (United States)

    Thomas, J.T.; Culler, M.E.; Dermisis, D.C.; Pierce, Clay; Papanicolaou, A.N.; Stewart, T.W.; Larson, C.J.

    2011-01-01

    Land use changes and channelization of streams in the deep loess region of western Iowa have led to stream channel incision, altered flow regimes, increased sediment inputs, decreased habitat diversity and reduced lateral connectivity of streams and floodplains. Grade control structures (GCSs) are built in streams to prevent further erosion, protect infrastructure and reduce sediment loads. However, GCS can have a detrimental impact on fisheries and biological communities. We review three complementary biological and hydraulic studies on the effects of GCS in these streams. GCS with steep (≥1:4 rise : run) downstream slopes severely limited fish passage, but GCS with gentle slopes (≤1:15) allowed greater passage. Fish assemblages were dominated by species tolerant of degradation, and Index of Biotic Integrity (IBI) scores were indicative of fair or poor biotic integrity. More than 50% of fish species had truncated distributions. After modification of GCS to reduce slopes and permit increased passage, IBI scores increased and several species were detected further upstream than before modification. Total macroinvertebrate density, biomass and taxonomic diversity and abundance of ecologically sensitive taxa were greater at GCS than in reaches immediately upstream, downstream or ≥1 km from GCS. A hydraulic study confirmed results from fish passage studies; minimum depths and maximum current velocities at GCS with gentle slopes (≤1:15) were more likely to meet minimum criteria for catfish passage than GCS with steeper slopes. Multidisciplinary approaches such as ours will increase understanding of GCS-associated factors influencing fish passage, biological assemblage structure and other ecological relationships in streams.

  12. Can polar bear hairs absorb environmental energy?

    Directory of Open Access Journals (Sweden)

    He Ji-Huan

    2011-01-01

    Full Text Available A polar bear (Ursus maritimus has superior ability to survive in harsh Arctic regions, why does the animal have such an excellent thermal protection? The present paper finds that the unique labyrinth cavity structure of the polar bear hair plays an important role. The hair can not only prevent body temperature loss but can also absorb energy from the environment.

  13. Device for absorbing seismic effects on buildings

    International Nuclear Information System (INIS)

    Xercavins, Pierre; Pompei, Michel.

    1979-01-01

    Device for absorbing seismic effects. The construction or structure to be protected rests on its foundations through at least one footing formed of a stack of metal plates interlinked by layers of adhesive material, over at least a part of their extent, this material being an elastomer that can distort, characterized in that at least part of the area of some metal plates works in association with components which are able to absorb at least some of the energy resulting from friction during the relative movements of the metal plates against the distortion of the elastomer [fr

  14. Metamaterial electromagnetic wave absorbers.

    Science.gov (United States)

    Watts, Claire M; Liu, Xianliang; Padilla, Willie J

    2012-06-19

    The advent of negative index materials has spawned extensive research into metamaterials over the past decade. Metamaterials are attractive not only for their exotic electromagnetic properties, but also their promise for applications. A particular branch-the metamaterial perfect absorber (MPA)-has garnered interest due to the fact that it can achieve unity absorptivity of electromagnetic waves. Since its first experimental demonstration in 2008, the MPA has progressed significantly with designs shown across the electromagnetic spectrum, from microwave to optical. In this Progress Report we give an overview of the field and discuss a selection of examples and related applications. The ability of the MPA to exhibit extreme performance flexibility will be discussed and the theory underlying their operation and limitations will be established. Insight is given into what we can expect from this rapidly expanding field and future challenges will be addressed. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Heterogeneous neutron absorbers development

    International Nuclear Information System (INIS)

    Boccaccini, Aldo; Agueda, Horacio; Russo, Diego; Perez, Edmundo

    1987-01-01

    The use of solid burnable absorber materials in power light water reactors has increased in the last years, specially due to improvements attained in costs of generated electricity. The present work summarizes the basic studies made on an alumina-gadolinia system, where alumina is the inert matrix and gadolinia acts as burnable poison, and describes the fabrication method of pellets with that material. High density compacts were obtained in the range of concentrations used by cold pressing and sintering at 1600 deg C in inert (Ar) atmosphere. Finally, the results of the irradiation experiences made at RA-6 reactor, located at the Bariloche Atomic Center, are given where variations on negative reactivity caused by introduction of burnable poison rods were measured. The results obtained from these experiences are in good agreement with those coming from calculation codes. (Author)

  16. Optimization of sound absorbing performance for gradient multi-layer-assembled sintered fibrous absorbers

    Science.gov (United States)

    Zhang, Bo; Zhang, Weiyong; Zhu, Jian

    2012-04-01

    The transfer matrix method, based on plane wave theory, of multi-layer equivalent fluid is employed to evaluate the sound absorbing properties of two-layer-assembled and three-layer-assembled sintered fibrous sheets (generally regarded as a kind of compound absorber or structures). Two objective functions which are more suitable for the optimization of sound absorption properties of multi-layer absorbers within the wider frequency ranges are developed and the optimized results of using two objective functions are also compared with each other. It is found that using the two objective functions, especially the second one, may be more helpful to exert the sound absorbing properties of absorbers at lower frequencies to the best of their abilities. Then the calculation and optimization of sound absorption properties of multi-layer-assembled structures are performed by developing a simulated annealing genetic arithmetic program and using above-mentioned objective functions. Finally, based on the optimization in this work the thoughts of the gradient design over the acoustic parameters- the porosity, the tortuosity, the viscous and thermal characteristic lengths and the thickness of each samples- of porous metals are put forth and thereby some useful design criteria upon the acoustic parameters of each layer of porous fibrous metals are given while applying the multi-layer-assembled compound absorbers in noise control engineering.

  17. Ferrite HOM Absorber for the RHIC ERL

    Energy Technology Data Exchange (ETDEWEB)

    Hahn,H.; Choi, E.M.; Hammons, L.

    2008-10-01

    A superconducting Energy Recovery Linac is under construction at Brookhaven National Laboratory to serve as test bed for RHIC upgrades. The damping of higher-order modes in the superconducting five-cell cavity for the Energy-Recovery linac at RHIC is performed exclusively by two ferrite absorbers. The ferrite properties have been measured in ferrite-loaded pill box cavities resulting in the permeability values given by a first-order Debye model for the tiled absorber structure and an equivalent permeability value for computer simulations with solid ring dampers. Measured and simulated results for the higher-order modes in the prototype copper cavity are discussed. First room-temperature measurements of the finished niobium cavity are presented which confirm the effective damping of higher-order modes in the ERL. by the ferrite absorbers.

  18. Evaluation of low-grade glioma structural changes after chemotherapy using DTI-based histogram analysis and functional diffusion maps

    Energy Technology Data Exchange (ETDEWEB)

    Castellano, Antonella; Iadanza, Antonella; Falini, Andrea [San Raffaele Scientific Institute and Vita-Salute San Raffaele University, Neuroradiology Unit and CERMAC, Milano (Italy); Donativi, Marina [University of Salento, Department of Mathematics and Physics ' ' Ennio De Giorgi' ' and A.D.A.M. (Advanced Data Analysis in Medicine), Lecce (Italy); Ruda, Roberta; Bertero, Luca; Soffietti, Riccardo [University of Torino, Department of Neuro-oncology, Turin (Italy); De Nunzio, Giorgio [University of Salento, Department of Mathematics and Physics ' ' Ennio De Giorgi' ' and A.D.A.M. (Advanced Data Analysis in Medicine), Lecce (Italy); INFN (National Institute of Nuclear Physics), Lecce (Italy); Riva, Marco; Bello, Lorenzo [Universita degli Studi di Milano, Milan, and Humanitas Research Hospital, Department of Medical Biotechnology and Translational Medicine, Rozzano, MI (Italy); Rucco, Matteo [University of Camerino, School of Science and Technology, Computer Science Division, Camerino, MC (Italy)

    2016-05-15

    To explore the role of diffusion tensor imaging (DTI)-based histogram analysis and functional diffusion maps (fDMs) in evaluating structural changes of low-grade gliomas (LGGs) receiving temozolomide (TMZ) chemotherapy. Twenty-one LGG patients underwent 3T-MR examinations before and after three and six cycles of dose-dense TMZ, including 3D-fluid-attenuated inversion recovery (FLAIR) sequences and DTI (b = 1000 s/mm{sup 2}, 32 directions). Mean diffusivity (MD), fractional anisotropy (FA), and tensor-decomposition DTI maps (p and q) were obtained. Histogram and fDM analyses were performed on co-registered baseline and post-chemotherapy maps. DTI changes were compared with modifications of tumour area and volume [according to Response Assessment in Neuro-Oncology (RANO) criteria], and seizure response. After three cycles of TMZ, 20/21 patients were stable according to RANO criteria, but DTI changes were observed in all patients (Wilcoxon test, P ≤ 0.03). After six cycles, DTI changes were more pronounced (P ≤ 0.005). Seventy-five percent of patients had early seizure response with significant improvement of DTI values, maintaining stability on FLAIR. Early changes of the 25th percentiles of p and MD predicted final volume change (R{sup 2} = 0.614 and 0.561, P < 0.0005, respectively). TMZ-related changes were located mainly at tumour borders on p and MD fDMs. DTI-based histogram and fDM analyses are useful techniques to evaluate the early effects of TMZ chemotherapy in LGG patients. (orig.)

  19. Reflection measurements of microwave absorbers

    Science.gov (United States)

    Baker, Dirk E.; van der Neut, Cornelis A.

    1988-12-01

    A swept-frequency interferometer is described for making rapid, real-time assessments of localized inhomogeneities in planar microwave absorber panels. An aperture-matched exponential horn is used to reduce residual reflections in the system to about -37 dB. This residual reflection is adequate for making comparative measurements on planar absorber panels whose reflectivities usually fall in the -15 to -25 dB range. Reflectivity measurements on a variety of planar absorber panels show that multilayer Jaumann absorbers have the greatest inhomogeneity, while honeycomb absorbers generally have excellent homogeneity within a sheet and from sheet to sheet. The test setup is also used to measure the center frequencies of resonant absorbers. With directional couplers and aperture-matched exponential horns, the technique can be easily applied in the standard 2 to 40 GHz waveguide bands.

  20. Aperiodic-metamaterial-based absorber

    Directory of Open Access Journals (Sweden)

    Quanlong Yang

    2017-09-01

    Full Text Available The periodic-metamaterial-based perfect absorber has been studied broadly. Conversely, if the unit cell in the metamaterial-based absorber is arranged aperiodically (aperiodic-metamaterial-based absorber, how does it perform? Inspired by this, here we present a systematic study of the aperiodic-metamaterial-based absorber. By investigating the response of metamaterial absorbers based on periodic, Fibonacci, Thue-Morse, and quasicrystal lattices, we found that aperiodic-metamaterial-based absorbers could display similar absorption behaviors as the periodic one in one hand. However, their absorption behaviors show different tendency depending on the thicknesses of the spacer. Further studies on the angle and polarization dependence of the absorption behavior are also presented.

  1. Performance evaluation of CFRP-rubber shock absorbers

    Science.gov (United States)

    Lamanna, Giuseppe; Sepe, Raffaele

    2014-05-01

    In the present work a numerical investigation on the energy absorbing capability of dedicated structural components made of a carbon fiber reinforced polymer and an emulsion polymerised styrene butadiene rubber is reported. The shock absorbers are devices designed to absorb large amounts of energy by sacrificing their own structural integrity. Their aim is to cushion the effects of an impact phenomenon with the intent to preserve other structures from global failure or local damaging. Another important role of shock absorbers is reducing the peak of the acceleration showed during an impact phenomenon. This effect is of considerable interest in the case of vehicles to preserve passengers' safety. Static and dynamic numerical results are compared with experimental ones in terms of mean crushing forces, energy and peak crushing. The global performance of the absorbers has been evaluated by referencing to a proposed quality index.

  2. Performance evaluation of CFRP-rubber shock absorbers

    Energy Technology Data Exchange (ETDEWEB)

    Lamanna, Giuseppe, E-mail: giuseppe.lamanna@unina2.it; Sepe, Raffaele, E-mail: giuseppe.lamanna@unina2.it [Department of Industrial and Information Engineering, Second University of Naples, via Roma, 29 - 81031 Aversa (Italy)

    2014-05-15

    In the present work a numerical investigation on the energy absorbing capability of dedicated structural components made of a carbon fiber reinforced polymer and an emulsion polymerised styrene butadiene rubber is reported. The shock absorbers are devices designed to absorb large amounts of energy by sacrificing their own structural integrity. Their aim is to cushion the effects of an impact phenomenon with the intent to preserve other structures from global failure or local damaging. Another important role of shock absorbers is reducing the peak of the acceleration showed during an impact phenomenon. This effect is of considerable interest in the case of vehicles to preserve passengers’ safety. Static and dynamic numerical results are compared with experimental ones in terms of mean crushing forces, energy and peak crushing. The global performance of the absorbers has been evaluated by referencing to a proposed quality index.

  3. Neutron absorbing element

    International Nuclear Information System (INIS)

    Kasai, Shigeo.

    1991-01-01

    The present invention concerns a neutron absorbing element of a neutron shielding member used for an LMFBR type reactor. The inside of a fuel can sealed at both of the upper and the lower ends thereof with plugs is partitioned into an upper and a lower chambers by an intermediate plug. A discharging hole is disposed at the upper end plug, which is in communication with the outside. A communication tube is disposed at the intermediate end plug and it is in communication with the lower chamber containing B 4 C pellets. A cylindrical support member having three porous plugs connected in series is disposed at the lower surface of the discharging hole provided at the upper end plug. Further, the end of the discharging hole is sealed with high temperature solder and He atmosphere is present at the inside of the fuel can. With such a constitution, the supporting differential pressure of the porous plugs can be made greater while discharging He gases generated from B 4 C to the outside. Further, the porous plugs can be surely wetted by coolants. Accordingly, it is possible to increase life time and shorten the size. (I.N.)

  4. Review of Plasmonic Nanocomposite Metamaterial Absorber

    Directory of Open Access Journals (Sweden)

    Mehdi Keshavarz Hedayati

    2014-02-01

    Full Text Available Plasmonic metamaterials are artificial materials typically composed of noble metals in which the features of photonics and electronics are linked by coupling photons to conduction electrons of metal (known as surface plasmon. These rationally designed structures have spurred interest noticeably since they demonstrate some fascinating properties which are unattainable with naturally occurring materials. Complete absorption of light is one of the recent exotic properties of plasmonic metamaterials which has broadened its application area considerably. This is realized by designing a medium whose impedance matches that of free space while being opaque. If such a medium is filled with some lossy medium, the resulting structure can absorb light totally in a sharp or broad frequency range. Although several types of metamaterials perfect absorber have been demonstrated so far, in the current paper we overview (and focus on perfect absorbers based on nanocomposites where the total thickness is a few tens of nanometer and the absorption band is broad, tunable and insensitive to the angle of incidence. The nanocomposites consist of metal nanoparticles embedded in a dielectric matrix with a high filling factor close to the percolation threshold. The filling factor can be tailored by the vapor phase co-deposition of the metallic and dielectric components. In addition, novel wet chemical approaches are discussed which are bio-inspired or involve synthesis within levitating Leidenfrost drops, for instance. Moreover, theoretical considerations, optical properties, and potential application of perfect absorbers will be presented.

  5. Structural and Morphological Difference Between Ti/TiN/TiCN Coatings Grown in Multilayer and Graded Form

    International Nuclear Information System (INIS)

    Restrepo, E.; Baena, A.; Agudelo, C.; Castillo, H.; Devia, A.; Marino, A.

    2006-01-01

    Thin films can be grown in super-lattice, multilayers and graded form, having each one advantages and disadvantages. The difference between multilayer and graded coatings is the interface. In multilayers the interface is abrupt and in graded coatings it is diffuse. The interface influences many chemical and physical properties of the materials, and its choice depends on the application. Graded coatings have the advantage of having gradual properties such as thermal expansion coefficient and lattice parameter, avoiding adherence problems due to good match between their component materials. In this work the comparison between some properties of coatings grown as multilayer and graded is performed. The materials are produced using the sputtering DC technique because of its facility to control the deposition parameters and generate a slow growth. The target is a disc of titanium and the samples are made of stainless steel 304. The working gases are argon, nitrogen and methane, which are mixed according to the material to be produced, i.e. Ti layer is grown with argon, the TiN film is produced with a mixture of argon and nitrogen, and the TiCN material is obtained mixing argon, nitrogen and methane. These materials are characterized with AFM in order to determine grain size and with XPS studying the chemical composition and performing depth profiles

  6. Structure, electrochemistry and spectroscopy of a new diacylhydrazido-bridged diruthenium complex with a strongly near-infrared absorbing RuIIIRuII intermediate

    Czech Academy of Sciences Publication Activity Database

    Jana, R.; Sarkar, B.; Bubrin, D.; Fiedler, Jan; Kaim, W.

    2010-01-01

    Roč. 13, č. 10 (2010), s. 1160-1162 ISSN 1387-7003 R&D Projects: GA MŠk OC 140; GA MŠk OC09043 Institutional research plan: CEZ:AV0Z40400503 Keywords : crystal structure * hydrazido ligand * near-infrared ruthenium Subject RIV: CG - Electrochemistry Impact factor: 1.974, year: 2010

  7. Burnable absorber coated nuclear fuel

    International Nuclear Information System (INIS)

    Chubb, W.; Radford, K.C.; Parks, B.H.

    1984-01-01

    A nuclear fuel body which is at least partially covered by a burnable neutron absorber layer is provided with a hydrophobic overcoat generally covering the burnable absorber layer and bonded directly to it. In a method for providing a UO 2 fuel pellet with a zirconium diboride burnable poison layer, the fuel body is provided with an intermediate niobium layer. (author)

  8. Leaf absorbance and photosynthesis

    Science.gov (United States)

    Schurer, Kees

    1994-01-01

    The absorption spectrum of a leaf is often thought to contain some clues to the photosynthetic action spectrum of chlorophyll. Of course, absorption of photons is needed for photosynthesis, but the reverse, photosynthesis when there is absorption, is not necessarily true. As a check on the existence of absorption limits we measured spectra for a few different leaves. Two techniques for measuring absorption have been used, viz. the separate determination of the diffuse reflectance and the diffuse transmittance with the leaf at a port of an integrating sphere and the direct determination of the non-absorbed fraction with the leaf in the sphere. In a cross-check both methods yielded the same results for the absorption spectrum. The spectrum of a Fuchsia leaf, covering the short-wave region from 350 to 2500 nm, shows a high absorption in UV, blue and red, the well known dip in the green and a steep fall-off at 700 nm. Absorption drops to virtually zero in the near infrared, with subsequent absorptions, corresponding to the water absorption bands. In more detailed spectra, taken at 5 nm intervals with a 5 nm bandwidth, differences in chlorophyll content show in the different depths of the dip around 550 nm and in a small shift of the absorption edge at 700 nm. Spectra for Geranium (Pelargonium zonale) and Hibiscus (with a higher chlorophyll content) show that the upper limit for photosynthesis can not be much above 700 nm. No evidence, however, is to be seen of a lower limit for photosynthesis and, in fact, some experiments down to 300 nm still did not show a decrease of the absorption although it is well recognized that no photosynthesis results with 300 nm wavelengths.

  9. Improved irradiation tolerance of reactive gas pulse sputtered TiN coatings with a hybrid architecture of multilayered and compositionally graded structures

    Science.gov (United States)

    Liang, Wei; Yang, Jijun; Zhang, Feifei; Lu, Chenyang; Wang, Lumin; Liao, Jiali; Yang, Yuanyou; Liu, Ning

    2018-04-01

    This study investigates the improved irradiation tolerance of reactive gas pulse (RGP) sputtered TiN coatings which has hybrid architecture of multilayered and compositionally graded structures. The multilayered RGP-TiN coating is composed of hexagonal close-packed Ti phase and face-centred cubic TiN phase sublayers, where the former sublayer has a compositionally graded structure and the latter one maintains constant stoichiometric atomic ratio of Ti:N. After 100 keV He ion irradiation, the RGP-TiN coating exhibits improved irradiation resistance compared with its single layered (SL) counterpart. The size and density of He bubbles are smaller in the RGP-TiN coating than in the SL-TiN coating. The irradiation-induced surface blistering of the coatings shows a similar tendency. Meanwhile, the irradiation hardening and adhesion strength of the RGP-TiN coatings were not greatly affected by He irradiation. Moreover, the irradiation damage tolerance of the coatings can be well tuned by changing the undulation period number of N2 gas flow rate. Detailed analysis suggested that this improved irradiation tolerance could be related to the combined contribution of the multilayered and compositionally graded structures.

  10. Design and Fabrication of Al2O3-(W, TiC-TiN-Mo-Ni Nano-composite Cermet Tool Materials with Graded Structures

    Directory of Open Access Journals (Sweden)

    NI Xiu-ying

    2018-02-01

    Full Text Available Based on the analysis on temperature and stress distributions, as well as fatigue crack propagation in cutting tools, a model for designing compositional distribution and microstructure with graded characteristics was proposed. The addition of ductile phase and the introduction of the graded structure are beneficial to slow down the fatigue crack propagation rate and improve tool life.Al2O3-(W,TiC-TiN-Mo-Ni nano-composite tool material with graded structures was fabricated via two stage hot pressing sintering process, and the microstructure and mechanical properties were studied. The results show that the surface hardness, fracture toughness of inner layer and bending strength of the cermet with sintered gradient structure reach 19.258GPa, 10.015MPa·m1/2 and 1017.475MPa,respectively.The performance requirements to cutting tools were met. The dimple cleavage and torn edge of the binding phase in the fracture surfaces can be beneficial to the improvement of the fracture toughness and bending strength,so the resistance to fatigue crack propagation of tools is improved.

  11. Absorbing rods for nuclear fast neutron reactor absorbing assembly

    International Nuclear Information System (INIS)

    Aji, M.; Ballagny, A.; Haze, R.

    1986-01-01

    The invention proposes a neutron absorber rod for neutron absorber assembly of a fast neutron reactor. The assembly comprises a bundle of vertical rods, each one comprising a stack of pellets made of a neutron absorber material contained in a long metallic casing with a certain radial play with regard to this casing; this casing includes traps for splinters from the pellets which may appear during reactor operation, at the level of contact between adjacent pellets. The present invention prevents the casing from rupture involved by the disintegration of the pellets producing pieces of boron carbide of high hardness [fr

  12. The Generic Structure Potential of Science Nonfiction Selections in Four Basal Reading Series, Grades One and Two

    Science.gov (United States)

    Anthony, Angela Beckman

    2009-01-01

    Basal reading series are used in a majority of classrooms in the United States. The purpose of this study was to examine the frequency of fiction and nonfiction genres included in four recently published first and second grade basal reading series and to compare the frequencies to studies of older basal reading series. Based on the work of…

  13. The Structure of an Early Reading Test in Grade 1: In Search of a Relationship with Reading in Spanish

    Science.gov (United States)

    Lara, Monica

    2010-01-01

    This study examined the "Tejas LEE or El Inventario de Lectura en Espanol de Tejas" (Grade 1) to determine if a relationship existed between reading comprehension in Spanish and the tested skills on the diagnostic assessment. This quantitative research design evaluated the psychometric characteristics of the Tejas LEE and followed customary…

  14. Structuring and calorie control of bakery products by templating batter with ultra melt-resistant food-grade hydrogel beads

    NARCIS (Netherlands)

    Thompson, Benjamin R.; Horozov, Tommy S.; Stoyanov, Simeon D.; Paunov, Vesselin N.

    2017-01-01

    We report the use of a temperature insensitive, food-grade hydrogel to reduce the caloric density of pancakes that were prepared at temperatures much higher than the boiling point of water. This cheap, facile method utilises a mixed agar-methylcellulose hydrogel, which was blended to produce a

  15. Crystal Structure Analysis of Electromagnetic Wave Absorber Material BaFe12-xTix/2Znx/2O19Based

    Science.gov (United States)

    Delina, M.; Nenni, N.; Adi, W. A.

    2018-04-01

    The optimization of BaFe12-xTix/2Znx/2O19 (x=2.2; 2.4; 2.6; 2.8)single phase composition have been performed. The materials were synthesized by solid state reaction method through mechanical milling technique.The materials were made from the mixture of oxide materials, which are BaCO3, Fe2O3, TiO2 and ZnO. The mixture was milled for five hours using a High Energy Milling (HEM), was dried at 100°C in the Oven and then was sintered at 1000°C for five hours in the Furnace. The phase identification of BaFe12-xTix/2Znx/2O19 (x=2.2; 2.4; 2.6; 2.8) were carried out by using a Match Program while the crystal structure analysis were investigated by using a General Structure Analysis System (GSAS) program. The refinement results of x-ray diffraction pattern showed that the sample of x ≤ 2.4 have a BaFe12O19 single phase while the sample of x> 2.4 have two phases, which are BaFe12O19 and ZnFe2O4 phases. The surface morphology of sample and the element of sample were identified through an analysis of Scanning Electron Microscope (SEM) and Energy Dispersive Spectroscopy (EDS) data.

  16. A Comuputerized DRBEM model for generalized magneto-thermo-visco-elastic stress waves in functionally graded anisotropic thin film/substrate structures

    Directory of Open Access Journals (Sweden)

    Mohamed Abdelsabour Fahmy

    Full Text Available A numerical computer model, based on the dual reciprocity boundary element method (DRBEM for studying the generalized magneto-thermo-visco-elastic stress waves in a rotating functionally graded anisotropic thin film/substrate structure under pulsed laser irradiation is established. An implicit-implicit staggered algorithm was proposed and implemented for use with the DRBEM to get the solution for the temperature, displacement components and thermal stress components through the structure thickness. A comparison of the results for different theories is presented in the presence and absence of rotation. Some numerical results that demonstrate the validity of the proposed method are also presented.

  17. Effect of gradient dielectric coefficient in a functionally graded material (FGM) substrate on the propagation behavior of love waves in an FGM-piezoelectric layered structure.

    Science.gov (United States)

    Cao, Xiaoshan; Shi, Junping; Jin, Feng

    2012-06-01

    The propagation behavior of Love waves in a layered structure that includes a functionally graded material (FGM) substrate carrying a piezoelectric thin film is investigated. Analytical solutions are obtained for both constant and gradient dielectric coefficients in the FGM substrate. Numerical results show that the gradient dielectric coefficient decreases phase velocity in any mode, and the electromechanical coupling factor significantly increases in the first- and secondorder modes. In some modes, the difference in Love waves' phase velocity between these two types of structure might be more than 1%, resulting in significant differences in frequency of the surface acoustic wave devices.

  18. Photoelectron antibunching and absorber theory

    International Nuclear Information System (INIS)

    Pegg, D.T.

    1980-01-01

    The recently detected photoelectron antibunching effect is considered to be evidence for the quantised electromagnetic field, i.e. for the existence of photons. Direct-action quantum absorber theory, on the other hand, has been developed on the basis that the quantised field is illusory, with quantisation being required only for atoms. In this paper it is shown that photoelectron antibunching is readily explicable in terms of absorber theory and in fact is directly attributable to the quantum nature of the emitting and detecting atoms alone. The physical nature of the reduction of the wavepacket associated with the detection process is briefly discussed in terms of absorber theory. (author)

  19. Liquid metal reactor absorber technology

    International Nuclear Information System (INIS)

    Pitner, A.L.

    1990-10-01

    The selection of boron carbide as the reference liquid metal reactor absorber material is supported by results presented for irradiation performance, reactivity worth compatibility, and benign failure consequences. Scram response requirements are met easily with current control rod configurations. The trend in absorber design development is toward larger sized pins with fewer pins per bundle, providing economic savings and improved hydraulic characteristics. Very long-life absorber designs appear to be attainable with the application of vented pin and sodium-bonded concepts. 3 refs., 3 figs

  20. Design, Synthesis, Structural and Spectroscopic Studies of Push-Pull Two-Photon Absorbing Chromophores with Acceptor Groups of Varying Strength

    Science.gov (United States)

    Morales, Alma R.; Frazer, Andrew; Woodward, Adam W.; Ahn-White, Hyo-Yang; Fonari, Alexandr; Tongwa, Paul; Timofeeva, Tatiana; Belfield, Kevin D.

    2013-01-01

    A new series of unsymmetrical diphenylaminofluorene-based chromophores with various strong π-electron acceptors were synthesized and fully characterized. The systematic alteration of the structural design facilitated the investigation of effects such as molecular symmetry and strength of electron-donating and/or withdrawing termini have on optical nonlinearity. In order to determine the electronic and geometrical properties of the novel compounds, a thorough investigation was carried out by a combination of linear and nonlinear spectroscopic techniques, single crystal X-ray diffraction, and quantum chemical calculations. Finally, on the basis of two-photon absorption (2PA) cross sections, the general trend for π -electron accepting ability, i.e., ability to accept charge transfer from diphenylamine was: 2-pyran-4-ylidene malononitrile (pyranone) > dicyanovinyl > bis(dicyanomethylidene)indane > 1-(thiophen-2-yl)propenone > dicyanoethylenyl > 3-(thiophen-2-yl)propenone. An analog with the 2-pyran-4-ylidene malononitrile acceptor group exhibited a nearly three-fold enhancement of the 2PA< δ (1650 GM at 840 nm), relative to other members of the series. PMID:23305555

  1. Changes in species, grade, and structure over 48 years in a managed New England northern hardwood stand

    Science.gov (United States)

    William B. Leak; Paul E. Sendak

    2002-01-01

    Three individual-tree selection harvests over a 48 yr period in a northern hardwood stand in New Hampshire resulted in an increase in the percentage of volume in trees with grade 1 and 2 butt logs from 21% (1952) to 30% (2000) in beech and 40% (1952) to 65% (2000) in sugar maple and other hardwoods. By 2000, 90% of the volume was in tolerant species.

  2. Neutron-absorbing alloys

    International Nuclear Information System (INIS)

    Portnoi, K.I.; Arabei, L.B.; Gryaznov, G.M.; Levi, L.I.; Lunin, G.L.; Kozhukhov, V.M.; Markov, J.M.; Fedotov, M.E.

    1975-01-01

    A process is described for the production of an alloy consiting of 1 to 20% In, 0.5 to 15% Sm, and from 3 to 18% Hf, the balance being Ni. Such alloys show a good absorption capacity for thermal and intermediate neutrons, good neutron capture efficiency, and good corrosion resistance, and find application in nuclear reactor automatic control and safety systems. The Hf provides for the maintenance of a reasonably high order of neutron capture efficiency throughout the lifetime of a reactor. The alloys are formed in a vacuum furnace operating with an inert gas atmosphere at 280 to 300 mm.Hg. They have a corrosion resistance from 3 to 3.5 times that of the Ag-based alloys commonly employed, and a neutron capture efficiency about twice that of the Ag alloys. Castability and structural strength are good. (U.K.)

  3. Absorber materials in CANDU PHWR's

    International Nuclear Information System (INIS)

    Price, E.G.; Boss, C.R.; Novak, W.Z.; Fong, R.W.L.

    1995-03-01

    In a CANDU reactor the fuel channels are arranged on a square lattice in a calandria filled with heavy water moderator. This arrangement allows five types of tubular neutron absorber devices to be located in a relatively benign environment of low pressure, low temperature heavy water between neighbouring rows of columns of fuel channels. This paper will describe the roles of the devices and outline the design requirements of the absorber component from a reactor physics viewpoint. Nuclear heating and activation problems associated with the different absorbers will be briefly discussed. The design and manufacture of the devices will be also discussed. The control rod absorbers and shut off materials are cadmium and stainless steel. In the tubular arrangement, the cadmium is sandwiched between stainless steel tubes. This type of device has functioned well, but there is now concern over the availability and expense of cadmium which is used in two types of CANDU control devices. There are also concerns about the toxicity of cadmium during the fabrication of the absorbers. These concerns are prompting AECL to study alternatives. To minimize design changes, pure boron-10 alloyed in stainless steel is a favoured option. Work is underway to confirm the suitability of the boron-loaded steel and identify other encapsulated absorber materials for practical application. Because the reactivity devices or their guide tubes span the calandria vessel, the long slender components must be sufficiently rigid to resist operational vibration and also be seismically stable. Some of these components are made of Zircaloy to minimize neutron absorption. Slow irradiation growth and creep can reduce the spring tension, and periodic adjustments to the springs are required. Experience with the control absorber devices has generally been good. In one instance liquid zone controllers had a problem of vibration induced fretting but a designed back-fit resolved the problem. (author). 3 refs., 1

  4. Optical and non-optical characterization of Nb2O5-SiO2 compositional graded-index layers and rugate structures

    International Nuclear Information System (INIS)

    Leitel, Robert; Stenzel, Olaf; Wilbrandt, Steffen; Gaebler, Dieter; Janicki, Vesna; Kaiser, Norbert

    2006-01-01

    The deposition of graded-index layers and rugate structures was performed by coevaporation of silicon dioxide as the low index material and niobium pentoxide as the high index material. To obtain information about the composition depth profile of the films, we used cross-sectional transmission electron microscopy to supplement deposition rate data recorded by two independent crystal quartz monitors during film preparation. The concentration depth profile was transformed to a refractive index profile using the effective medium approximation. The thus obtained refractive index profiles turned out to represent efficient initial approximations for re-engineering purposes

  5. Functionally graded biomimetic energy absorption concept development for transportation systems.

    Science.gov (United States)

    2014-02-01

    Mechanics of a functionally graded cylinder subject to static or dynamic axial loading is considered, including a potential application as energy absorber. The mass density and stiffness are power functions of the radial coordinate as may be the case...

  6. Crystallographic structures of absorbates and neutron diffraction

    International Nuclear Information System (INIS)

    Marti, C.; Thorel, P.

    1975-01-01

    The advantage of neutron diffraction is that it is possible to work at any pressure and therefore to study an adsorbant-adsorbate couple within a wide pressure and temperature range and at thermodynamic equilibrium. Nitrogen adsorbed on graphite and CF 4 adsorbed on graphite were measured [fr

  7. Preparation of Active Absorbent for Flue Gas Desulfurization From Coal Bottom Ash: Effect of Absorbent Preparation Variables

    Directory of Open Access Journals (Sweden)

    Chang Chin Li, Lee Keat Teong, Subhash Bhatia and Abdul Rahman Mohamed

    2012-08-01

    Full Text Available An active absorbent for flue gas desulfurization was prepared from coal bottom ash, calcium oxide (CaO and calcium sulfate by hydro-thermal process. The absorbent was examined for its micro-structural properties. The experiments conducted were based on Design Of Experiments (DOE according to 23 factorial design. The effect of various absorbent preparation variables such as ratio of CaO to bottom ash (A, hydration temperature (B and hydration period (C towards the BET (Brunauer-Emmett-Teller specific surface area of the absorbent were studied. At a CaO to bottom ash ratio = 2, hydration temperature = 200 ?C and hydration period = 10 hrs, absorbent with a surface area of 90.1 m2/g was obtained. Based on the analysis of the factorial design, it was concluded that factor A and C as well as the interaction of factors ABC and BC are the significant factors that effect the BET surface area of the absorbent. A linear mathematical model that describes the relation between the independent variables and interaction between variables towards the BET specific surface area of the absorbent was also developed. Analysis of variance (ANOVA showed that the model was significant at 1% level.Key Words: Absorbent, Bottom Ash, Design Of Experiments, Desulfurization, Surface Area.

  8. The Effect of Ga2Se3 Doping Ratios on Structure, Composition, and Electrical Properties of CuIn0.5Ga0.5Se2 Absorber Formed by Thermal Sintering

    Directory of Open Access Journals (Sweden)

    Chung Ping Liu

    2013-01-01

    Full Text Available Chalcopyrite compounds of copper indium gallium diselenide (CIGS absorber were fabricated by using binary-particle (Cu2Se, In2Se3, and Ga2Se3 precursors with thermal sintering method. The binary-particle ink was firstly prepared by milling technology and then printed onto a soda lime glass substrate, which was baked at a low temperature to remove solvents and form a dry precursor. Following milling, the average particle size of agglomerated CIGS powder is smaller than 1.1 μm. Crystallographic, stoichiometric, and electrical properties of precursor CIGS films with various doping amounts of Ga2Se3 had been widely investigated by using thermal sintering in a nonvacuum environment without selenization. Analytical results reveal that the CIGS absorption layer prepared with a Ga2Se3 doping ratio of 3 has a chalcopyrite structure and favorable composition. The mole ratio of Cu : In : Ga : Se of this sample was 1.03 : 0.49 : 0.54 : 1.94, and related ratios of Ga/(In + Ga and Cu/(In + Ga were 0.52 and 0.99, respectively. The resistivity and carrier concentration were 3.77 ohm-cm and 1.15 E  +  18 cm-3.

  9. Design and testing of a shock absorber for a type I container

    International Nuclear Information System (INIS)

    Sappok, M.; Beine, B.; Rittscher, D.; Jais, M.

    1994-01-01

    A simple method of designing a shock absorber to protect a type B cast-iron container is developed. The results of deformation tests of the structural material (steel pipes) used for the shock absorber are presented. The accelerations and strains measured during the 9m drop tests of the container with the shock absorber are compared with the theoretical results of the calculations for the shock absorber design. ((orig.))

  10. Graphene Based Terahertz Absorber Designed With Effective Surface Conductivity Approach

    DEFF Research Database (Denmark)

    Andryieuski, Andrei; Pizzocchero, Filippo; Booth, Tim

    Young field of terahertz (THz) science and technology demands new materials and devices, such as filters, modulators, polarization converters and absorbers. Graphene, a recently discovered single-atom-thick material, provides exciting properties for functional terahertz applications. Graphene...... conductivity and how to use it in optical design. We demonstrate a tunable THz perfect absorber, which consists of continuous graphene various structured graphene metamaterials above a metal mirror. Changing the Fermi level from 0 eV to 0.5 eV allows for drastic changes in absorbance from less than 0.1 to 1...

  11. Neutron physics calculation for WWER-1000 absorber element lifetime determination

    International Nuclear Information System (INIS)

    Kurakin, K.Yu.; Kushmanov, S.A.

    2009-01-01

    Absorber element with compound absorber has been operating in WWER-1000 power units since 1995. AE design meets operating organizations requirements for reliability, service life (to 10 years) and safety functions. Extension of AE service life up to 20 - 30 years by the complex of calculation and experimental work is an important problem of WWER new designs development. The paper deals with the issues related to calculation determination of main factors that influence AE service life limitation - neutron flux and fluence onto absorbing and structural materials during extended service life. (Authors)

  12. Simultaneous impact of neutron irradiation and sputtering on the surface structure of self–damaged ITER–grade tungsten

    Energy Technology Data Exchange (ETDEWEB)

    Belyaeva, A. I., E-mail: aibelyaeva@mail.ru; Savchenko, A. A. [National Technical University “Kharkov Politechnical Institute”, Kharkov, 61002 (Ukraine); Galuza, A. A.; Kolenov, I. V. [Institute of Electrophysics and Radiation Technologies, National Academy of Science of Ukraine, Kharkov, 61024 (Ukraine)

    2014-07-15

    Simultaneous effects of neutron irradiation and long–term sputtering on the surface relief of ITER–grade tungsten were studied. The effects of neutron–induced displacement damage have been simulated by irradiation of tungsten target with W{sup 6+} ions of 20 MeV energy. Ar{sup +} ions with energy 600 eV were used as imitation of charge exchange atoms in ITER. The surface relief was studied after each sputtering act. The singularity in the WJ–IG surface relief was ascertained experimentally at the first time, which determines the law of roughness extension under sputtering. As follows from the experimental data, the neutron irradiation has not to make a decisive additional contribution in the processes developing under impact of charge exchange atoms only.

  13. Adaptive inertial shock-absorber

    International Nuclear Information System (INIS)

    Faraj, Rami; Holnicki-Szulc, Jan; Knap, Lech; Seńko, Jarosław

    2016-01-01

    This paper introduces and discusses a new concept of impact absorption by means of impact energy management and storage in dedicated rotating inertial discs. The effectiveness of the concept is demonstrated in a selected case-study involving spinning management, a recently developed novel impact-absorber. A specific control technique performed on this device is demonstrated to be the main source of significant improvement in the overall efficiency of impact damping process. The influence of various parameters on the performance of the shock-absorber is investigated. Design and manufacturing challenges and directions of further research are formulated. (paper)

  14. Examination of the Structure and Grade-Related Differentiation of Multidimensional Self-Concept Instruments for Children Using ESEM

    Science.gov (United States)

    Arens, A. Katrin; Morin, Alexandre J. S.

    2016-01-01

    This study is a substantive-methodological synergy in which exploratory structural equation modeling is applied to investigate the factor structure of multidimensional self-concept instruments. On the basis of a sample of German students (N = 1958) who completed the Self-Description Questionnaire I and the Self-Perception Profile for Children, the…

  15. Microwave absorbing property of a hybrid absorbent with carbonyl irons coating on the graphite

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Yonggang, E-mail: xuyonggang221@163.com [Science and Technology on Electromagnetic Scattering Laboratory, Shanghai, 200438 (China); Yan, Zhenqiang; Zhang, Deyuan [Bionic and Micro/Nano/Bio Manufacturing Technology Research Center, School of Mechanical Engineering and Automation, Beihang University, Beijing 100191 (China)

    2015-11-30

    Graphical abstract: The absorbing property could be enhanced as the CIPs coated on the graphite. - Highlights: • Absorbers filled with CIPs coating on the graphite was fabricated. • The permittivity and permeability increased as CIPs coated. • The CIP materials enhanced the electromagnetic property. • The graphite coated CIPs were effective in 2–18 GHz. - Abstract: The hybrid absorbent filled with carbonyl iron particles (CIPs) coating on the graphite was prepared using a chemical vapor decomposition (CVD) process. X-ray diffraction (XRD) patterns were done to analyze the particle crystal grain structure. The complex permittivity and permeability were measured using a vector network analyzer in the frequency range of 2–18 GHz. The results showed that α-Fe appeared in the super-lattice diffraction peaks in XRD graph. The composites added CIPs coating on the graphite had a higher permittivity and imaginary permeability due to the superior microwave dielectric loss and magnetic loss of the CIPs. The reflection loss (RL) result showed that composites filled with 5 vol% Fe-graphite had an excellent absorbing property in the 2–18 GHz, the minimum RL was −25.14 dB at 6 mm and −26.52 dB at 8 mm, respectively.

  16. Broadband infrared metamaterial absorber based on anodic aluminum oxide template

    Science.gov (United States)

    Yang, Jingfan; Qu, Shaobo; Ma, Hua; Wang, Jiafu; Yang, Shen; Pang, Yongqiang

    2018-05-01

    In this work, a broadband infrared metamaterial absorber is proposed based on trapezoid-shaped anodic aluminum oxide (AAO) template. Unlike traditional metamaterial absorber constructed from metal-dielectric-metal sandwich structure, our proposed absorber is composed of trapezoid-shaped AAO template with metallic nanowires inside. The infrared absorption efficiency is numerically calculated and the mechanism analysis is given in the paper. Owing to the superposition of multiple resonances produced by the nanowires with different heights, the infrared metamatrial absorber can keep high absorption efficiency during broad working wavelength band from 3.4 μm to 6.1 μm. In addition, the resonance wavelength is associated with the height of nanowires, which indicates that the resonance wavelength can be modulated flexibly through changing the heights of nanowires. This kind of design can also be adapted to other wavelength regions.

  17. Tunable enhanced optical absorption of graphene using plasmonic perfect absorbers

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Yijun [Institute of Optoelectronic Technology, Department of Electronic Engineering, Xiamen University, Xiamen 361005 (China); Institute of Electromagnetics and Acoustics, Department of Electronic Science, Xiamen University, Xiamen 361005 (China); Zhu, Jinfeng, E-mail: nanoantenna@hotmail.com [Institute of Electromagnetics and Acoustics, Department of Electronic Science, Xiamen University, Xiamen 361005 (China); Liu, Qing Huo [Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708 (United States)

    2015-01-26

    Enhancement and manipulation of light absorption in graphene is a significant issue for applications of graphene-based optoelectronic devices. In order to achieve this purpose in the visible region, we demonstrate a design of a graphene optical absorber inspired by metal-dielectric-metal metamaterial for perfect absorption of electromagnetic waves. The optical absorbance ratios of single and three atomic layer graphene are enhanced up to 37.5% and 64.8%, respectively. The graphene absorber shows polarization-dependence and tolerates a wide range of incident angles. Furthermore, the peak position and bandwidth of graphene absorption spectra are tunable in a wide wavelength range through a specific structural configuration. These results imply that graphene in combination with plasmonic perfect absorbers have a promising potential for developing advanced nanophotonic devices.

  18. A chiral microwave absorbing absorbent of Fe–CoNiP coated on spirulina

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Yonggang, E-mail: xuyonggang221@163.com [Science and Technology on Electromagnetic Scattering Laboratory, Shanghai, 200438 (China); Yuan, Liming [Science and Technology on Electromagnetic Scattering Laboratory, Shanghai, 200438 (China); Zhang, Deyuan [School of Mechanical Engineering and Automation, Beihang University, Beijing, 100191 (China)

    2015-11-15

    A chiral bio-absorbent of Fe–CoNiP coated on the spirulina was fabricated by the electroless and chemical vapor decomposition. The scanning electron microscopy (SEM) was used to evaluate the spirulina cells particle morphology. X-ray diffraction (XRD) patterns were done to analyze the particle crystal grain structure. The permittivity and permeability was measured by a vector network analyzer in frequency 8–18 GHz, and the reflection loss (RL) was calculated. The results showed the carbonyl iron particles (CIPs) and CoNiP were bonded to the spirulina surface, the permittivity and permeability could be enlarged as Fe films coated on the particles compared with the CoNiP spirulina, it was attributed to the excellent electromagnetic property of CIPs. The chiral Fe–CoNiP composites had a better absorbing property at 8–18 GHz than the CoNiP spirulina composite, the RL was −16.26 dB at 10.48 GHz, the absorbing band was 9.5–11.5 GHz of RL less than −10 dB, which indicated the Fe–CoNiP spirulina could be an effective absorbent used in 8–18 GHz. - Highlights: • Absorbers filled with Fe–CoNiP coating on the spirulina were fabricated. • The permittivity and permeability increased as CIPs coated. • The Fe material enhanced the electromagnetic property. • The spirulina coated Fe–CoNiP was effective in 8–18 GHz.

  19. Structural and optical properties of silicon rich oxide films in graded-stoichiometric multilayers for optoelectronic devices

    Energy Technology Data Exchange (ETDEWEB)

    Palacios-Huerta, L.; Aceves-Mijares, M. [Electronics Department, INAOE, Apdo. 51, Puebla, Pue. 72000, México (Mexico); Cabañas-Tay, S. A.; Cardona-Castro, M. A.; Morales-Sánchez, A., E-mail: alfredo.morales@cimav.edu.mx [Centro de Investigación en Materiales Avanzados S.C., Unidad Monterrey-PIIT, Apodaca, NL 66628, México (Mexico); Domínguez-Horna, C. [Instituto de Microelectrónica de Barcelona, IMB-CNM (CSIC), Bellaterra 08193, Barcelona (Spain)

    2016-07-18

    Silicon nanocrystals (Si-ncs) are excellent candidates for the development of optoelectronic devices. Nevertheless, different strategies are still necessary to enhance their photo and electroluminescent properties by controlling their structural and compositional properties. In this work, the effect of the stoichiometry and structure on the optical properties of silicon rich oxide (SRO) films in a multilayered (ML) structure is studied. SRO MLs with silicon excess gradually increased towards the top and bottom and towards the center of the ML produced through the variation of the stoichiometry in each SRO layer were fabricated and confirmed by X-ray photoelectron spectroscopy. Si-ncs with three main sizes were observed by a transmission electron microscope, in agreement with the stoichiometric profile of each SRO layer. The presence of the three sized Si-ncs and some oxygen related defects enhances intense violet/blue and red photoluminescence (PL) bands. The SRO MLs were super-enriched with additional excess silicon by Si{sup +} implantation, which enhanced the PL intensity. Oxygen-related defects and small Si-ncs (<2 nm) are mostly generated during ion implantation enhancing the violet/blue band to become comparable to the red band. The structural, compositional, and luminescent characteristics of the multilayers are the result of the contribution of the individual characteristics of each layer.

  20. Digital Alloy Absorber for Photodetectors

    Science.gov (United States)

    Hill, Cory J. (Inventor); Ting, David Z. (Inventor); Gunapala, Sarath D. (Inventor)

    2016-01-01

    In order to increase the spectral response range and improve the mobility of the photo-generated carriers (e.g. in an nBn photodetector), a digital alloy absorber may be employed by embedding one (or fraction thereof) to several monolayers of a semiconductor material (insert layers) periodically into a different host semiconductor material of the absorber layer. The semiconductor material of the insert layer and the host semiconductor materials may have lattice constants that are substantially mismatched. For example, this may performed by periodically embedding monolayers of InSb into an InAsSb host as the absorption region to extend the cutoff wavelength of InAsSb photodetectors, such as InAsSb based nBn devices. The described technique allows for simultaneous control of alloy composition and net strain, which are both key parameters for the photodetector operation.

  1. Insight into magnetorheological shock absorbers

    CERN Document Server

    Gołdasz, Janusz

    2015-01-01

    This book deals with magnetorheological fluid theory, modeling and applications of automotive magnetorheological dampers. On the theoretical side a review of MR fluid compositions and key factors affecting the characteristics of these fluids is followed by a description of existing applications in the area of vibration isolation and flow-mode shock absorbers in particular. As a majority of existing magnetorheological devices operates in a so-called flow mode a critical review is carried out in that regard. Specifically, the authors highlight common configurations of flow-mode magnetorheological shock absorbers, or so-called MR dampers that have been considered by the automotive industry for controlled chassis applications. The authors focus on single-tube dampers utilizing a piston assembly with one coil or multiple coils and at least one annular flow channel in the piston.

  2. Enhancement of acoustical performance of hollow tube sound absorber

    International Nuclear Information System (INIS)

    Putra, Azma; Khair, Fazlin Abd; Nor, Mohd Jailani Mohd

    2016-01-01

    This paper presents acoustical performance of hollow structures utilizing the recycled lollipop sticks as acoustic absorbers. The hollow cross section of the structures is arranged facing the sound incidence. The effects of different length of the sticks and air gap on the acoustical performance are studied. The absorption coefficient was measured using impedance tube method. Here it is found that improvement on the sound absorption performance is achieved by introducing natural kapok fiber inserted into the void between the hollow structures. Results reveal that by inserting the kapok fibers, both the absorption bandwidth and the absorption coefficient increase. For test sample backed by a rigid surface, best performance of sound absorption is obtained for fibers inserted at the front and back sides of the absorber. And for the case of test sample with air gap, this is achieved for fibers introduced only at the back side of the absorber.

  3. Enhancement of acoustical performance of hollow tube sound absorber

    Energy Technology Data Exchange (ETDEWEB)

    Putra, Azma, E-mail: azma.putra@utem.edu.my; Khair, Fazlin Abd, E-mail: fazlinabdkhair@student.utem.edu.my; Nor, Mohd Jailani Mohd, E-mail: jai@utem.edu.my [Centre for Advanced Research on Energy, Universiti Teknikal Malaysia Melaka, Hang Tuah Jaya, Durian Tunggal Melaka 76100 Malaysia (Malaysia)

    2016-03-29

    This paper presents acoustical performance of hollow structures utilizing the recycled lollipop sticks as acoustic absorbers. The hollow cross section of the structures is arranged facing the sound incidence. The effects of different length of the sticks and air gap on the acoustical performance are studied. The absorption coefficient was measured using impedance tube method. Here it is found that improvement on the sound absorption performance is achieved by introducing natural kapok fiber inserted into the void between the hollow structures. Results reveal that by inserting the kapok fibers, both the absorption bandwidth and the absorption coefficient increase. For test sample backed by a rigid surface, best performance of sound absorption is obtained for fibers inserted at the front and back sides of the absorber. And for the case of test sample with air gap, this is achieved for fibers introduced only at the back side of the absorber.

  4. Acoustic Properties of Absorbent Asphalts

    Science.gov (United States)

    Trematerra, Amelia; Lombardi, Ilaria

    2017-08-01

    Road traffic is one of the greater cause of noise pollution in urban centers; a prolonged exposure to this source of noise disturbs populations subjected to it. In this paper is reported a study on the absorbent coefficients of asphalt. The acoustic measurements are carried out with a impedance tube (tube of Kundt). The sample are measured in three conditions: with dry material (traditional), “wet” asphalt and “dirty” asphalt.

  5. Effects of WC Particle Size and Co Content on the Graded Structure in Functionally Gradient WC-Co Composites

    Directory of Open Access Journals (Sweden)

    Yuan Yigao

    2016-01-01

    Full Text Available Functionally gradient WC-Co composites having a Co depleted surface zone and not comprising the h phase can be manufactured via carburizing process. During carburizing, besides carburizing process parameters, the microstructural parameters of WC-Co materials, such as WC grain size and Co content, also have significant influences on the formation of Co gradient structure. In this study, the effects of WC particle size and Co content on the gradient structure within gradient hardmetals have been studied, based on a series of carburizing experiments of WC-Co materials with different WC particle sizes and cobalt contents. The results show that both the thickness and the amplitude of the gradients within gradient WC-Co materials increase with increasing initial WC particle size and Co content of WC-Co alloys. The reason for this finding is discussed.

  6. Cermet based solar selective absorbers : further selectivity improvement and developing new fabrication technique

    OpenAIRE

    Nejati, Mohammadreza

    2008-01-01

    Spectral selectivity of cermet based selective absorbers were increased by inducing surface roughness on the surface of the cermet layer using a roughening technique (deposition on hot substrates) or by micro-structuring the metallic substrates before deposition of the absorber coating using laser and imprint structuring techniques. Cu-Al2O3 cermet absorbers with very rough surfaces and excellent selectivity were obtained by employing a roughness template layer under the infrared reflective l...

  7. Electrochemical Corrosion Testing of Neutron Absorber Materials

    International Nuclear Information System (INIS)

    Tedd Lister; Ron Mizia; Sandra Birk; Brent Matteson; Hongbo Tian

    2006-01-01

    The Yucca Mountain Project (YMP) has been directed by DOE-RW to develop a new repository waste package design based on the transport, aging, and disposal canister (TAD) system concept. A neutron poison material for fabrication of the internal spent nuclear fuel (SNF) baskets for these canisters needs to be identified. A material that has been used for criticality control in wet and dry storage of spent nuclear fuel is borated stainless steel. These stainless products are available as an ingot metallurgy plate product with a molybdenum addition and a powder metallurgy product that meets the requirements of ASTM A887, Grade A. A new Ni-Cr-Mo-Gd alloy has been developed by the Idaho National Laboratory (INL) with its research partners (Sandia National Laboratory and Lehigh University) with DOE-EM funding provided by the National Spent Nuclear Fuel Program (NSNFP). This neutron absorbing alloy will be used to fabricate the SNF baskets in the DOE standardized canister. The INL has designed the DOE Standardized Spent Nuclear Fuel Canister for the handling, interim storage, transportation, and disposal in the national repository of DOE owned spent nuclear fuel (SNF). A corrosion testing program is required to compare these materials in environmental conditions representative of a breached waste canister. This report will summarize the results of crevice corrosion tests for three alloys in solutions representative of ionic compositions inside the waste package should a breech occur. The three alloys in these tests are Neutronit A978 (ingot metallurgy, hot rolled), Neutrosorb 304B4 Grade A (powder metallurgy, hot rolled), and Ni-Cr-Mo-Gd alloy (ingot metallurgy, hot rolled)

  8. Corundum-based transparent infrared absorbers

    KAUST Repository

    Schwingenschlögl, Udo

    2009-10-01

    Hypothetical corundum-based compounds are studied by electronic structure calculations. One quarter of the Al atoms in Al2O3 is replaced by a 3d transition metal from the M = Ti, ..., Zn (d1, ..., d9) series. Structure optimisations are performed for all the M-Al2O3 compounds and the electronic states are evaluated. Due to the M substitutes, narrow partially filled bands are formed at the Fermi energy. Beyond, for M = Ni and M = Cu the optical properties of Al2O3 in the visible range are conserved, while for M = Ti, ..., Co the systems form high accuracy optical filters. Since the compounds absorb the infrared radiation, the M = Ni and M = Cu systems are good candidates for heat-protective coatings. © 2009 Elsevier B.V. All rights reserved.

  9. Ultrathin microwave metamaterial absorber utilizing embedded resistors

    Science.gov (United States)

    Kim, Young Ju; Hwang, Ji Sub; Yoo, Young Joon; Khuyen, Bui Xuan; Rhee, Joo Yull; Chen, Xianfeng; Lee, YoungPak

    2017-10-01

    We numerically and experimentally studied an ultrathin and broadband perfect absorber by enhancing the bandwidth with embedded resistors into the metamaterial structure, which is easy to fabricate in order to lower the Q-factor and by using multiple resonances with the patches of different sizes. We analyze the absorption mechanism in terms of the impedance matching with the free space and through the distribution of surface current at each resonance frequency. The magnetic field, induced by the antiparallel surface currents, is formed strongly in the direction opposite to the incident electromagnetic wave, to cancel the incident wave, leading to the perfect absorption. The corresponding experimental absorption was found to be higher than 97% in 0.88-3.15 GHz. The agreement between measurement and simulation was good. The aspects of our proposed structure can be applied to future electronic devices, for example, advanced noise-suppression sheets in the microwave regime.

  10. Superficial characterization and nano structural of nano multilayers Cr/Cr N obtained by UBM with different unbalance grades

    International Nuclear Information System (INIS)

    Piratoba, U.; Arenas A, J.; Olaya, J. J.

    2013-01-01

    Coatings of 25 bilayers of Cr/Cr N, with total thickness between 1.32 and 1.67 microns, were deposited by reactive sputtering on silicon and H13 steel, in argon and argon with nitrogen atmospheres. A power of 160 watts, flows of argon and nitrogen of 9 and 3 sc cm respectively, and an axial unbalanced magnetron, whose coefficient of geometrical unbalance K G was varied between 0.85 and 1.37. Of these coatings, micrographs of surface and cross section scanning electron microscopy were obtained, was make a micro structural characterization with X-ray diffraction, a nano structural characterization by transmission electron microscopy, and surface characterization by atomic force microscopy in tapping mode: analysis showed uniform surface coating with globular and pyramidal formations, which contain some granular inclusions and microscopic craters. With the increase in the unbalance of the magnetic field, the grain size, the roughness and the speed of the coatings growth were increased. (Author)

  11. An ultra-broadband multilayered graphene absorber

    KAUST Repository

    Amin, Muhammad; Farhat, Mohamed; Bagci, Hakan

    2013-01-01

    An ultra-broadband multilayered graphene absorber operating at terahertz (THz) frequencies is proposed. The absorber design makes use of three mechanisms: (i) The graphene layers are asymmetrically patterned to support higher order surface plasmon

  12. Study the Characterization of Spectral Absorbance on Irradiated Milk Protein

    Science.gov (United States)

    Fohely, F.; Suardi, N.

    2018-04-01

    The milk has been adopted as a structural nature food for a long era since it is containing most of the growth factors, protective agents, and enzymes needed for the body. a few attempts have been conducted to treat the dairy products especially raw milk by the means of ionizing radiation. as its production has been an expanding industry for many years due to the high demands from the consumers worldwide, there is still some doubt about preserving these products by irradiation. In this work, a preliminary effort to describe the influences of ionizing radiation on raw milk’s protein will be devoted to measuring the spectral absorbance of the total protein (after subjected to varied radiation doses) by UV-VIS-NIR spectroscopy analysis. The absorbance spectrum then analyzed based on absorbance spectra of organic compounds. A comparison is made between the effects of different radiation doses to estimate the influence in milk’s structure.

  13. Piezooptic effect of absorbing environment

    Directory of Open Access Journals (Sweden)

    Ю. А. Рудяк

    2013-07-01

    Full Text Available Application of piezooptic effect of absorbing environment for the definition of the parameter of stress deformation state was examined. The analysis of dielectric permeability tensor of imaginary parts was done. It is shown that changes in the real part dielectric permeability tensor mainly the indicator of fracture was fixed by means of mechanics interference methods and the changes in the imaginary part (α – real rate of absorption can be measured by means of analysis of light absorption and thus stress deformation state can be determined

  14. Energy absorbers as pipe supports

    International Nuclear Information System (INIS)

    Khlafallah, M.Z.; Lee, H.M.

    1985-01-01

    With the exception of springs, pipe supports currently in use are designed with the intent of maintaining their rigidity under load. Energy dissipation mechanisms in these pipe supports result in system damping on the order presented by Code Case N-411 of ASME Section III code. Examples of these energy dissipation mechanisms are fluids and gaps in snubbers, gaps in frame supports, and friction in springs and frame supports. If energy absorbing supports designed in accordance with Code Case N-420 are used, higher additional damping will result

  15. Development of Mole Concept Module Based on Structured Inquiry with Interconection of Macro, Submicro, and Symbolic Representation for Grade X of Senior High School

    Science.gov (United States)

    Sagita, R.; Azra, F.; Azhar, M.

    2018-04-01

    The research has created the module of mole concept based on structured inquiry with interconection of macro, submicro, and symbolic representation and determined the validity and practicality of the module. The research type was Research and Development (R&D). The development model was 4-D models that consist of four steps: define, design, develop, and disseminate. The research was limited on develop step. The instrument of the research was questionnaire form that consist of validity and practicality sheets. The module was validated by 5 validators. Practicality module was tested by 2 chemistry teachers and 28 students of grade XI MIA 5 at SMAN 4 of Padang. Validity and practicality data were analysed by using the kappa Cohen formula. The moment kappa average of 5 validators was 0,95 with highest validity category. The moment kappa average of teachers and students were 0,89 and 0,91 praticality with high category. The result of the research showed that the module of mole concept based on structured inquiry with interconection of macro, submicro, and symbolic representation was valid and practice to be used on the learning chemistry.

  16. Improving the prediction of strength and rigidity of structural timber by combining ultrasound techniques with visual grading parameters

    Directory of Open Access Journals (Sweden)

    Hermoso Prieto, E.

    2007-12-01

    Full Text Available The present study explores the possibility of using longitudinal ultrasound transmission to evaluate the bending strength and modulus of elasticity in structural timber made from the two species most commonly found in Spanish construction and rehabilitation works: Scots pine (Pinus sylvestris L. and Laricio pine (Pinus nigra Arn.. An analysis of 1305 Scots pine and 852 Laricio pine beams shows that ultrasound transmission velocity alone can predict neither the bending strength nor the modulus of elasticity and that other predictive variables are required.A series of models are proposed based on ultrasound transmission velocity measurements, the relative size of the largest face and edge knots, length and density. After running models for each species individually and for the two jointly, a single model is found to be suitable for both. The models proposed explain from 63 to 73 per cent of bending strength and modulus of elasticity variability.Se analiza la posibilidad de aplicar la técnica de transmisión longitudinal de ultrasonidos para la evaluación de la resistencia y módulo de elasticidad a flexión de la madera estructural de las dos especies de mayor interés constructivo y más amplia presencia en obras de rehabilitación: el pino silvestre (Pinus sylvestris L. y el pino laricio (Pinus nigra Arn.. Trabajando sobre un total de 1.305 vigas de pino silvestre y 852 de pino laricio se concluye que por sí sola la velocidad de transmisión de ultrasonidos no es un buen predictor ni de la resistencia ni del módulo de elasticidad en flexión, necesitando el complemento de otras variables predictoras. Se proponen diversos modelos basados en la medición de la velocidad de transmisión de ultrasonidos, de los diámetros relativos del nudo máximo de cara y de canto, de la longitud y de la densidad. Los modelos se proponen tanto a nivel especie como global, comprobándose que es posible emplear un modelo único para ambas especies. Los modelos

  17. Research on temperature characteristics of laser energy meter absorber irradiated by ms magnitude long pulse laser

    Science.gov (United States)

    Li, Nan; Qiao, Chunhong; Fan, Chengyu; Zhang, Jinghui; Yang, Gaochao

    2017-10-01

    The research on temperature characteristics for large-energy laser energy meter absorber is about continuous wave (CW) laser before. For the measuring requirements of millisecond magnitude long pulse laser energy, the temperature characteristics for absorber are numerically calculated and analyzed. In calculation, the temperature field distributions are described by heat conduction equations, and the metal cylinder cavity is used for absorber model. The results show that, the temperature of absorber inwall appears periodic oscillation with pulse structure, the oscillation period and amplitude respectively relate to the pulse repetition frequency and single pulse energy. With the wall deep increasing, the oscillation amplitude decreases rapidly. The temperature of absorber outerwall is without periodism, and rises gradually with time. The factors to affect the temperature rise of absorber are single pulse energy, pulse width and repetition frequency. When the laser irradiation stops, the temperature between absorber inwall and outerwall will reach agreement rapidly. After special technology processing to enhance the capacity of resisting laser damage for absorber inwall, the ms magnitude long pulse laser energy can be obtained with the method of measuring the temperature of absorber outerwall. Meanwhile, by optimization design of absorber structure, when the repetition frequency of ms magnitude pulse laser is less than 10Hz, the energy of every pulse for low repetition frequency pulse sequence can be measured. The work offers valuable references for the design of ms magnitude large-energy pulse laser energy meter.

  18. Selective solar absorber coating research at the CSIR (South Africa)

    CSIR Research Space (South Africa)

    Roro, Kittessa T

    2011-05-01

    Full Text Available A sol-gel technique has been established at a laboratory scale for low cost production of high efficient selective solar absorbers comprising a composite material of nano-structured carbon in a nickel oxide matrix. In order for these materials...

  19. Specification of absorbed dose for reporting a therapeutic irradiation

    International Nuclear Information System (INIS)

    Wambersie, A.; Chassagne, D.

    1981-01-01

    The problem of dose specification in external beam therapy with photons and electrons has been dealt with in ICRU Report 29 (1978). This problem arises from the fact that the absorbed dose distribution is usually not uniform in the target volume and that for the purpose of treatment reporting a nominal absorbed dose - which will be called target absorbed dose - has to be selected. When comparing the clinical results obtained between radiotherapy centres, the differences in the reported target absorbed doses which can be introduced by differences in the methods of dose specification often are much larger than the differences related to the dosimetric procedures themselves. This shows the importance of the problem. In this paper, some definitions of terms and concepts currently used in radiotherapy are first recalled: tumour volume, target volume, treatment volume, etc. These definitions have been proposed in ICRU Report 29 for photon and electron beams; they can be extended to any kind of irradiation. For external beam therapy with photons and electrons, the target absorbed dose is defined as the absorbed dose at selected point(s) (specification point(s)) having a meaningful relation to the target volume and/or the irradiation beams. Examples are discussed for typical cases. As far as interstitial and intracavitary therapy is concerned, the problem is more complex and no recommendations have so far been made by the ICRU Commission. A major difficulty arises from the sharp dose gradient as a function of the distance to the sources. The particular case of the treatment of cervix carcinoma is considered and some possible methods of specification are discussed: (1) the indication of the sources (in adequate units) and the duration of the application, (2) the absorbed doses at selected reference points (bladder, rectum, bony structures) and (3) the description of the tissue volume (height, width, thickness) encompassed by a given isodose surface (60Gy). (author)

  20. Calculation of absorbed dose in water by chemical Fricke dosimetry

    International Nuclear Information System (INIS)

    Rodrigues, Adenilson Paiva; Meireles, Ramiro Conceicao

    2016-01-01

    This work is the result of a laboratory activity performed in Radiological Sciences Laboratory (CRL), linked to the State University of Rio de Janeiro (UERJ). This practice aimed to determine the absorbed dose to water, through the primary calibration method called dosimetry Fricke, which consists of ferrous ions (Fe + 2) to ferric (Fe + 3), generated by water radiolysis products which is the structural change of water molecule caused by ionizing radiation. A spectrophotometer was used to extract data for analysis at a wavelength (λ) 304 and 224 nm with function of measuring the absorbance using bottles with irradiated and nonirradiated Fricke solution. (author)

  1. Dual band metamaterial perfect absorber based on Mie resonances

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xiaoming; Lan, Chuwen; Li, Bo; Zhou, Ji, E-mail: zhouji@tsinghua.edu.cn [State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Bi, Ke [School of Science, Beijing University of Posts and Telecommunications, Beijing 100876 (China); Zhao, Qian [State Key Lab of Tribology, Department of Precision Instruments and Mechanology, Tsinghua University, Beijing 100084 (China)

    2016-08-08

    We numerically and experimentally demonstrated a polarization insensitive dual-band metamaterial perfect absorber working in wide incident angles based on the two magnetic Mie resonances of a single dielectric “atom” with simple structure. Two absorption bands with simulated absorptivity of 99% and 96%, experimental absorptivity of 97% and 94% at 8.45 and 11.97 GHz were achieved due to the simultaneous magnetic and electric resonances in dielectric “atom” and copper plate. Mie resonances of dielectric “atom” provide a simple way to design metamaterial perfect absorbers with high symmetry.

  2. Integrated polymer waveguides for absorbance detection in chemical analysis systems

    DEFF Research Database (Denmark)

    Mogensen, Klaus Bo; El-Ali, Jamil; Wolff, Anders

    2003-01-01

    A chemical analysis system for absorbance detection with integrated polymer waveguides is reported for the first time. The fabrication procedure relies on structuring of a single layer of the photoresist SU-8, so both the microfluidic channel network and the optical components, which include planar....... The emphasis of this paper is on the signal-to-noise ratio of the detection and its relation to the sensitivity. Two absorbance cells with an optical path length of 100 μm and 1000 μm were characterized and compared in terms of sensitivity, limit of detection and effective path length for measurements...

  3. Oxalate: Effect on calcium absorbability

    International Nuclear Information System (INIS)

    Heaney, R.P.; Weaver, C.M.

    1989-01-01

    Absorption of calcium from intrinsically labeled Ca oxalate was measured in 18 normal women and compared with absorption of Ca from milk in these same subjects, both when the test substances were ingested in separate meals and when ingested together. Fractional Ca absorption from oxalate averaged 0.100 +/- 0.043 when ingested alone and 0.140 +/- 0.063 when ingested together with milk. Absorption was, as expected, substantially lower than absorption from milk (0.358 +/- 0.113). Nevertheless Ca oxalate absorbability in these women was higher than we had previously found for spinach Ca. When milk and Ca oxalate were ingested together, there was no interference of oxalate in milk Ca absorption and no evidence of tracer exchange between the two labeled Ca species

  4. Effect of water pressure on absorbency of hydroentangled greige cotton nonwoven fabrics

    Science.gov (United States)

    A studied has been conducted to determine the effect of water pressure in a commercial-grade Fleissner MiniJet hydroentanglement system on the absorbency of greige (non-bleached) cotton lint-based nonwoven fabric. The study has shown that a water pressure of 125 Bar or higher on only two high-pressu...

  5. The dynamics analysis of a ferrofluid shock absorber

    International Nuclear Information System (INIS)

    Yao, Jie; Chang, Jianjun; Li, Decai; Yang, Xiaolong

    2016-01-01

    The paper presents a shock absorber using three magnets as the inertial mass. Movement of the inertial mass inside a cylindrical body filled with ferrofluid will lead to a viscous dissipation of the oscillating system energy. The influence of a dumbbell-like ferrofluid structure on the energy dissipation is considered and the magnetic restoring force is investigated by experiment and theoretical calculation. A theoretical model of the hydrodynamics and energy dissipation processes is developed, which includes the geometrical characteristics of the body, the fluid viscosity, and the external magnetic field. The theory predicts the experimental results well under some condition. The shock absorber can be used in spacecraft technology. - Highlights: • We study a ferrofluid shock absorber. • The mechanical model of the flow of the ferrofluid has been built. • The theoretical model of the energy dissipation processes is developed. • The magnetic restoring force between the body and the magnets has been measured.

  6. The dynamics analysis of a ferrofluid shock absorber

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Jie; Chang, Jianjun [School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, Beijing 100044 (China); Li, Decai, E-mail: dcli@bjtu.edu.cn [School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, Beijing 100044 (China); Yang, Xiaolong [School of Mechanical Engineering, Guangxi University of Science and Technology, Liuzhou, Guangxi 545006 (China)

    2016-03-15

    The paper presents a shock absorber using three magnets as the inertial mass. Movement of the inertial mass inside a cylindrical body filled with ferrofluid will lead to a viscous dissipation of the oscillating system energy. The influence of a dumbbell-like ferrofluid structure on the energy dissipation is considered and the magnetic restoring force is investigated by experiment and theoretical calculation. A theoretical model of the hydrodynamics and energy dissipation processes is developed, which includes the geometrical characteristics of the body, the fluid viscosity, and the external magnetic field. The theory predicts the experimental results well under some condition. The shock absorber can be used in spacecraft technology. - Highlights: • We study a ferrofluid shock absorber. • The mechanical model of the flow of the ferrofluid has been built. • The theoretical model of the energy dissipation processes is developed. • The magnetic restoring force between the body and the magnets has been measured.

  7. The precipitation synthesis of broad-spectrum UV absorber nanoceria

    International Nuclear Information System (INIS)

    Nurhasanah, Iis; Sutanto, Heri; Puspaningrum, Nurul Wahyu

    2013-01-01

    In this paper the possibility of nanoceria as broad-spectrum UV absorber was evaluated. Nanoceria were synthesized by precipitation process from cerium nitrate solution and ammonium hydroxide as precipitant agent. Isopropanol was mixed with water as solvent to prevent hard agglomeration. The structure of resulting nanoceria was characterized by x-ray diffractometer (XRD). The transparency in the visible light and efficiency of protection in UV A region were studied using ultraviolet-visible (UV - Vis) spectrophotometer. The results show that nanoceria possess good tranparency in visible light and high UV light absorption. The critical absorption wavelenght of 368 nm was obtained which is desirable for excellent broad-spectrum protection absorbers. Moreover, analysis of photodegradation nanoceria to methylene blue solution shows poor photocatalytic activity. It indicates that nanoceria suitable for used as UV absorber in personal care products

  8. Laser Beam Melting of Alumina: Effect of Absorber Additions

    Science.gov (United States)

    Moniz, Liliana; Colin, Christophe; Bartout, Jean-Dominique; Terki, Karim; Berger, Marie-Hélène

    2018-03-01

    Ceramic laser beam melting offers new manufacturing possibilities for complex refractory structures. Poor absorptivity in near infra-red wavelengths of oxide ceramics is overcome with absorber addition to ceramic powders. Absorbers affect powder bed densities and geometrical stability of melted tracks. Optimum absorber content is defined for Al2O3 by minimizing powder bed porosity, maximizing melting pool geometrical stability and limiting shrinkage. Widest stability fields are obtained with addition of 0.1 wt.% C and 0.5 wt.% β-SiC. Absorption coefficient values of Beer-Lambert law follow stability trends: they increase with C additions, whereas with β-SiC, a maximum is reached for 0.5 wt.%. Powder particle ejections are also identified. Compared to metallic materials, this ejection phenomenon can no longer be neglected when establishing a three-dimensional manufacturing strategy.

  9. Robust optimization of a tandem grating solar thermal absorber

    Science.gov (United States)

    Choi, Jongin; Kim, Mingeon; Kang, Kyeonghwan; Lee, Ikjin; Lee, Bong Jae

    2018-04-01

    Ideal solar thermal absorbers need to have a high value of the spectral absorptance in the broad solar spectrum to utilize the solar radiation effectively. Majority of recent studies about solar thermal absorbers focus on achieving nearly perfect absorption using nanostructures, whose characteristic dimension is smaller than the wavelength of sunlight. However, precise fabrication of such nanostructures is not easy in reality; that is, unavoidable errors always occur to some extent in the dimension of fabricated nanostructures, causing an undesirable deviation of the absorption performance between the designed structure and the actually fabricated one. In order to minimize the variation in the solar absorptance due to the fabrication error, the robust optimization can be performed during the design process. However, the optimization of solar thermal absorber considering all design variables often requires tremendous computational costs to find an optimum combination of design variables with the robustness as well as the high performance. To achieve this goal, we apply the robust optimization using the Kriging method and the genetic algorithm for designing a tandem grating solar absorber. By constructing a surrogate model through the Kriging method, computational cost can be substantially reduced because exact calculation of the performance for every combination of variables is not necessary. Using the surrogate model and the genetic algorithm, we successfully design an effective solar thermal absorber exhibiting a low-level of performance degradation due to the fabrication uncertainty of design variables.

  10. An investigation of the relationships between junior high school students' (8th and 9th grades) background variables and structure of knowledge recall of biological content

    Science.gov (United States)

    Demetrius, Olive Joyce

    The purpose of this study was to examine the relationships between Junior High School students' (8th and 9th grades) background variables (e.g. cognitive factors, prior knowledge, preference for science versus non-science activities, formal and informal activities) and structure of information recall of biological content. In addition, this study will illustrate how flow maps, a graphic display, designed to represent the sequential flow and cross linkage of ideas in information recalled by the learner can be used as a tool for analyzing science learning data. The participants (46 junior high school students) were taught a lesson on the human digestive system during which they were shown a model of the human torso. Their pattern of information recall was determined by using an interview technique to elicit their understanding of the functional anatomy of the human digestive system. The taped responses were later transcribed for construction of the flow map. The interview was also used to assess knowledge recall of biological content. The flow map, science interest questionnaire and the cognitive operations (based on content analysis of student's narrative) were used to analyze data from each respondent. This is a case study using individual subjects and interview techniques. The findings of this study are: (1) Based on flow map data higher academic ability students have more networking of ideas than low ability students. (2) A large percentage of 9th grade low ability students intend to pursue science/applied science course work after leaving school but they lack well organized ways of representing science knowledge in memory. (3) Content analysis of the narratives shows that students with more complex ideational networks use higher order cognitive thought processes compared to those with less networking of ideas. If students are to make a successful transition from low academic performance to high academic performance it seems that more emphasis should be placed on

  11. Teachers' Grading Decision Making

    Science.gov (United States)

    Isnawati, Ida; Saukah, Ali

    2017-01-01

    This study investigated teachers' grading decision making, focusing on their beliefs underlying their grading decision making, their grading practices and assessment types, and factors they considered in grading decision making. Two teachers from two junior high schools applying different curriculum policies in grade reporting in Indonesian…

  12. Linear accelerator with x-ray absorbing insulators

    International Nuclear Information System (INIS)

    Rose, P.H.

    1975-01-01

    Annular insulators for supporting successive annular electrodes in a linear accelerator have embedded x-ray absorbing shield structures extending around the accelerating path. The shield members are disposed to intercept x-ray radiation without disrupting the insulative effect of the insulator members. In preferred forms, the structure comprises a plurality of annular members of heavy metal disposed in an x-ray blocking array, spaced from each other by the insulating substance of the insulator member. (auth)

  13. Structural investigation and microwave characteristics of (Ba{sub 0.2}La{sub 0.8})Fe{sub 0.2}Mn{sub 0.4}Ti{sub 0.4}O{sub 3} absorbing materials

    Energy Technology Data Exchange (ETDEWEB)

    Manaf, Azwar [Dept. of Physics, Faculty of Mathematics and Natural Sciences, Indonesia of University (Indonesia); Adi, Wisnu Ari, E-mail: dwisnuaa@batan.go.id [Center for Technology of Nuclear Industry Material, National Nuclear Energy Agency (Indonesia)

    2014-03-24

    Synthesis and characterization of (Ba{sub 0.2}La{sub 0.8})Fe{sub 0.2}Mn{sub 0.4}Ti{sub 0.4}O{sub 3} absorbing material by mechanical alloying process has been performed. The absorbing material was prepared by oxide materials, namely BaCO{sub 3}, La{sub 2}O{sub 3}, TiO{sub 2}, Fe{sub 2}O{sub 3}, and MnCO{sub 3}. The mixture was milled for 10 h and then sintered at a temperature of 1000 ° C for 10 h. The refinement results of x-ray diffraction pattern of lanthanum manganite substituted with barium showed that the sample consisted of two phases, namely, La{sub 0.9125}MnO{sub 3} phase which has a structure monoclinic (I12/a1) with lattice parameters a = 5.527(1) Å, b = 5.572(1) Å and c = 7.810(1) Å, α = γ = 90° and β = 89.88(5)°, the unit cell volume of V = 240.57(8) Å{sup 3}, and the atomic density of ρ = 6.238 gr.cm{sup −3}. The microstructure analyses showed that the particle shapes was polygonal with the varied particle sizes of 1 ∼ 3 μm distributed homogeneously on the surface of the samples. The results of the electromagnetic wave absorption curve analysis by using a vector network analyzer (VNA) showed that the sample can absorb microwaves in the frequency range of 8-15 GHz with a very wide absorption bandwidth. It indicates that the as prepared absorber presents potential absorbing property in X and Ku-band. We concluded that the (Ba{sub 0.2}La{sub 0.8})Fe{sub 0.2}Mn{sub 0.4}Ti{sub 0.4}O{sub 3} material can be applied as a candidate absorber material of microwaves or electromagnetic wave.

  14. Implementation and Evaluation of Web-Based Learning Activities on Bonding and the Structure of Matter for 10-th Grade Chemistry

    Science.gov (United States)

    Frailich, Marcel

    This study deals with the development, implementation, and evaluation of web-based activities associated with the topic of chemical bonding , as taught in 10th grade chemistry. A website was developed entitled: "Chemistry and the Chemical Industry in the Service of Mankind", its URL is: http://stwww.weizmann.ac.il/g-chem/learnchem (Kesner, Frailich, & Hofstein, 2003). The main goal of this study was to assess the educational effectiveness of website activities dealing with the chemical bonding concept. These activities include visualization tools, as well as topics relevant to daily life and industrial applications. The study investigated the effectiveness of a web-based learning environment regarding the understanding of chemical bonding concepts, students' perceptions of the classroom learning environment, their attitudes regarding the relevance of learning chemistry to everyday life, and their interest in chemistry studies. As mentioned before, in the present study we focused on activities (from the website), all of which deal with chemical bonding concept. The following are the reasons for the decision to focus on this topic: (1) Chemical bonding is a key concept that is taught in 10th grade chemistry in high school. It provides the basis for many other chemistry topics that are taught later, and (2) Chemical bonding is a difficult for students using existing tools (e. g., static models in books, ball-and- stick models), which are insufficient to demonstrate the abstract nature phenomena associated with this topic. The four activities developed for this study are (1) models of the atomic structure, (2) metals -- structure and properties, (3) ionic substances in everyday life and in industry, and (4) molecular substances -- structure, properties, and uses. The study analyzed both quantitative and qualitative research. The quantitative tools of the study included: A Semantic Differential questionnaire and a Chemistry Classroom Web-Based Learning Environment

  15. Student Attitudes Toward Grades and Grading Practices.

    Science.gov (United States)

    Stallings, William M.; Leslie, Elwood K.

    The result of a study designed to assess student attitudes toward grading practices are discussed. Questionnaire responses of 3439 students in three institutions were tabulated. Responses were generally negative toward conventional grading systems. (MS)

  16. Comments on liquid hydrogen absorbers for MICE

    International Nuclear Information System (INIS)

    Green, Michael A.

    2003-01-01

    This report describes the heat transfer problems associated with a liquid hydrogen absorber for the MICE experiment. This report describes a technique for modeling heat transfer from the outside world, to the absorber case and in its vacuum vessel, to the hydrogen and then into helium gas at 14 K. Also presented are the equation for free convection cooling of the liquid hydrogen in the absorber

  17. Absorbed dose by a CMOS in radiotherapy

    International Nuclear Information System (INIS)

    Borja H, C. G.; Valero L, C. Y.; Guzman G, K. A.; Banuelos F, A.; Hernandez D, V. M.; Vega C, H. R.; Paredes G, L. C.

    2011-10-01

    Absorbed dose by a complementary metal oxide semiconductor (CMOS) circuit as part of a pacemaker, has been estimated using Monte Carlo calculations. For a cancer patient who is a pacemaker carrier, scattered radiation could damage pacemaker CMOS circuits affecting patient's health. Absorbed dose in CMOS circuit due to scattered photons is too small and therefore is not the cause of failures in pacemakers, but neutron calculations shown an absorbed dose that could cause damage in CMOS due to neutron-hydrogen interactions. (Author)

  18. Multiband Negative Permittivity Metamaterials and Absorbers

    Directory of Open Access Journals (Sweden)

    Yiran Tian

    2013-01-01

    Full Text Available Design and characteristics of multiband negative permittivity metamaterial and its absorber configuration are presented in this paper. The proposed multiband metamaterial is composed of a novel multibranch resonator which can possess four electric resonance frequencies. It is shown that, by controlling the length of the main branches of such resonator, the resonant frequencies and corresponding absorbing bands of metamaterial absorber can be shifted in a large frequency band.

  19. Determination of absorbed dose in reactors

    International Nuclear Information System (INIS)

    1971-01-01

    There are many areas in the use and operation of research reactors where the absorbed dose and the neutron fluence are required. These include work on the determination of the radiolytic stability of the coolant and moderator and on the determination of radiation damage in structural materials, and reactor experiments involving radiation chemistry and radiation biology. The requirements range from rough estimates of the total heating due to radiation to precise values specifying the contributions of gamma rays, thermal neutrons and fast neutrons. To meet all these requirements a variety of experimental measurements and calculations as well as a knowledge of reactor radiations and their interactions is necessary. Realizing the complexity and importance of this field, its development at widely separated laboratories and the need to bring the experts in this work together, the IAEA has convened three panel meetings. These were: 'In-pile dosimetry', held in July 1964 (published by the Agency as Technical Reports Series No. 46); 'Neutron fluence measurements', in October 1965; and 'In-pile dosimetry', in November 1966. The recommendations of these three panels led the Agency to form a Working Group on Reactor Radiation Measurements and to commission the writing of this book and a book on Neutron Fluence Measurements. The latter was published in May 1970 (Technical Reports Series No. 107). The material on neutron fluence and absorbed dose measurements is widely scattered in reports and reviews. It was considered that it was time for all relevant information to be evaluated and put together in the form of a practical guide that would be valuable both to experienced workers and beginners in the field

  20. Absorber rod drive for nuclear reactors

    International Nuclear Information System (INIS)

    Acher, H.

    1985-01-01

    The invention concerns a further addition to the invention of DE 33 42 830 A1. The free contact of the hollow piston with the nut due to hydraulic pressure is replaced by a hydraulic or spring attachment. The pressure system required to produce the hydraulic pressure is therefore omitted, and the electrical power required for driving the pump or the mass flow is also omitted. The absorber rod slotted along its longitudinal axis is replaced by an absorber rod, in the longitudinal axis of which a hollow piston is connected together with the absorber rod. This makes the absorber rod more stable, and assembly is simplified. (orig./HP) [de

  1. TPX/TFTR Neutral Beam energy absorbers

    International Nuclear Information System (INIS)

    Dahlgren, F.; Wright, K.; Kamperschroer, J.; Grisham, L.; Lontai, L.; Peters, C.; VonHalle, A.

    1993-01-01

    The present beam energy absorbing surfaces on the TFTR Neutral Beams such as Ion Dumps, Calorimeters, beam defining apertures, and scrapers, are simple water cooled copper plates which wee designed to absorb (via their thermal inertia) the incident beam power for two seconds with a five minute coal down interval between pulses. These components are not capable of absorbing the anticipated beam power loading for 1000 second TPX pulses and will have to be replaced with an actively cooled design. While several actively cooled energy absorbing designs were considered,, the hypervapotron elements currently being used on the JET beamlines were chosen due to their lower cooling water demands and reliable performance on JET

  2. Self-assembly of highly efficient, broadband plasmonic absorbers for solar steam generation.

    Science.gov (United States)

    Zhou, Lin; Tan, Yingling; Ji, Dengxin; Zhu, Bin; Zhang, Pei; Xu, Jun; Gan, Qiaoqiang; Yu, Zongfu; Zhu, Jia

    2016-04-01

    The study of ideal absorbers, which can efficiently absorb light over a broad range of wavelengths, is of fundamental importance, as well as critical for many applications from solar steam generation and thermophotovoltaics to light/thermal detectors. As a result of recent advances in plasmonics, plasmonic absorbers have attracted a lot of attention. However, the performance and scalability of these absorbers, predominantly fabricated by the top-down approach, need to be further improved to enable widespread applications. We report a plasmonic absorber which can enable an average measured absorbance of ~99% across the wavelengths from 400 nm to 10 μm, the most efficient and broadband plasmonic absorber reported to date. The absorber is fabricated through self-assembly of metallic nanoparticles onto a nanoporous template by a one-step deposition process. Because of its efficient light absorption, strong field enhancement, and porous structures, which together enable not only efficient solar absorption but also significant local heating and continuous stream flow, plasmonic absorber-based solar steam generation has over 90% efficiency under solar irradiation of only 4-sun intensity (4 kW m(-2)). The pronounced light absorption effect coupled with the high-throughput self-assembly process could lead toward large-scale manufacturing of other nanophotonic structures and devices.

  3. Gaseous carbon dioxide absorbing column

    International Nuclear Information System (INIS)

    Harashina, Heihachi.

    1994-01-01

    The absorbing column of the present invention comprises a cyclone to which CO 2 gas and Ca(OH) 2 are blown to form CaCO 3 , a water supply means connected to an upper portion of the cyclone for forming a thin water membrane on the inner wall thereof, and a water processing means connected to a lower portion of the cyclone for draining water incorporating CaCO 3 . If a mixed fluid of CO 2 gas and Ca(OH) 2 is blown in a state where a flowing water membrane is formed on the inner wall of the cyclone, formation of CaCO 3 is promoted also in the inside of the cyclone in addition to the formation of CaCO 3 in the course of blowing. Then, formed CaCO 3 is discharged from the lower portion of the cyclone together with downwardly flowing water. With such procedures, solid contents such as CaCO 3 separated at the inner circumferential wall are sent into the thin water membrane, adsorbed and captured, and the solid contents are successively washed out, so that a phenomenon that the solid contents deposit and grow on the inner wall of the cyclone can be prevented effectively. (T.M.)

  4. Radiation absorbed doses in cephalography

    International Nuclear Information System (INIS)

    Eliasson, S.; Julin, P.; Richter, S.; Stenstroem, B.

    1984-01-01

    Radiation absorbed doses to different organs in the head and neck region in lateral (LAT) and postero-anterior (PA) cephalography were investigated. The doses were measured by thermoluminescence dosimeters (TLD) on a tissue equivalent phantom head. Lanthanide screens in speed group 4 were used at 90 and 85 k Vp. A near-focus aluminium dodger was used and the radiation beam was collimated strictly to the face. The maximum entrance dose from LAT was 0.25 mGy and 0.42 mGy from a PA exposure. The doses to the salivary glands ranged between 0.2 and 0.02 mGy at LAT and between 0.15 and 0.04 mGy at PA exposures. The average thyroid gland dose without any shielding was 0.11 mGy (LAT) and 0.06 mGy (PA). When a dodger was used the dose was reduced to 0.07 mGy (LAT). If the thyroid gland was sheilded off, the dose was further reduced to 0.01 mGy and if the thyroid region was collimated out of the primary radiation field the dose was reduced to only 0.005 mGy. (authors)

  5. Perpetual pavement – absorbing stress and functional maintenance

    Directory of Open Access Journals (Sweden)

    Rong Gao

    2017-03-01

    Full Text Available Perpetual Pavement combines the well documented smoothness and safety advantages of asphalt with an advanced, multi-layer paving design process, that with routine maintenance, extends the useful life of a roadway. Perpetual provides long lasting road and smoothness for the construction purposes. This study has the design key points of perpetual pavement based on the idea of life cycle, which has a new direction for the new highway construction, reconstruction and expansion. First, the structure of long life pavement design is studied to analyze the effect of stress absorbing layer. Second, researches on stress absorbing layer from the aspects of raw materials, mix proportion are implemented. Third, the design index of stress absorbing layer is determined by the shear strength test. The results show that the design idea of composite perpetual pavement can be realized by reasonable design of the stress absorbing layer and carrying out the surface functional maintenance can ensure the pavement to avoid structural damage in the operation stage.

  6. Effect of the ionizing radiation in polyurethane of medical grade

    International Nuclear Information System (INIS)

    Ceron, P.; Rivera, T.; Calderon, J. A.; Paredes, L.

    2011-10-01

    The polyurethane is a material broadly used in implant medical devices, such as the connection blocks of the pacemakers and the insulator of the electrodes. Some patients that are users of these devices possibly have the necessity to receive external radiotherapy. For that reason is necessary to know the effects induced by the ionizing radiation in this polymer. In this study samples of Pellethane 2363 80a (thermoplastic polyurethane of medical grade) were irradiated. It was used the same energy and absorbed dose of a treatment of external radiotherapy in pelvis, by means of a linear accelerator of X-rays of 6 MeV and absorbed dose of 60 Gy to isocenter. The irradiation corresponding to the gamma sterilization of the material was reproduced (1, 5, 7.5, 10 and 25 kGy for the Co 60) the effects induced by the radiotherapy and for the sterilization in the material were studied by means of an analysis of the chemical connection, the molecular structure and identification of the functional groups of the polymer, by means of the infrared spectroscopy by Fourier transform in the infrared half region. (Author)

  7. Absorbing Property of Multi-layered Short Carbon Fiber Absorbing Coating

    OpenAIRE

    Liu, Zhaohui; Tao, Rui; Ban, Guodong; Luo, Ping

    2018-01-01

    The radar absorbing coating was prepared with short carbon fiber asabsorbent and waterborne polyurethane (WPU) as matrix resin. The coating’s absorbing property was tested with vectornetwork analyzer, using aramid honeycomb as air layer which was matched withcarbon fiber coating. The results demonstrate that the single-layered carbonfiber absorbing coating presented relatively poor absorbing property when thelayer was thin, and the performance was slightly improved after the matched airlayer ...

  8. Absorber element for fast breeder reactor

    International Nuclear Information System (INIS)

    Verset, L.

    1987-01-01

    This absorber element is characterized by a new head which avoids an accident disconnection of the mobil absorber. This head is made by a superior piece which can take shore up an adjusting ring on an adjusting bearing on the inferior piece. The intermediate piece is catched at the superior piece by a link of chain [fr

  9. Analysis of absorbing times of quantum walks

    International Nuclear Information System (INIS)

    Yamasaki, Tomohiro; Kobayashi, Hirotada; Imai, Hiroshi

    2003-01-01

    Quantum walks are expected to provide useful algorithmic tools for quantum computation. This paper introduces absorbing probability and time of quantum walks and gives both numerical simulation results and theoretical analyses on Hadamard walks on the line and symmetric walks on the hypercube from the viewpoint of absorbing probability and time

  10. Absorber transmissivities in 57Fe Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Ballet, O.

    1985-01-01

    Some useful relations are derived for the polarization dependent optical index of 57 Fe Moessbauer absorbers. Real rotation matrices are extensively used and, besides wave-direction dependence, their properties simplify also the treatment of texture and f-anisotropy. The derivation of absorber transmissivities from the optical index is discussed with a special emphasis on line overlapping. (Auth.)

  11. Liquid absorber experiments in ZED-2

    International Nuclear Information System (INIS)

    McDonnell, F.N.

    1975-07-01

    A set of liquid absorber experiments was performed in ZED-2 to provide data with which to test the adequacy of calculational methods for zone controller and refuelling studies associated with advanced reactor concepts. The absorber consisted of a full length aluminum tube, containing either i)H 2 O, ii)H 2 O + boron (2.5 mg/ml) or iii)H 2 O + boron (8.0 mg/ml). The tube was suspended vertically at interstitial or in-channel locations. A U-tube absorber was also simulated using two absorber tubes with appropriate spacers. Experiments were carried out at two different square lattice pitches, 22.86 and 27.94 cm. Measurements were made of the reactivity effects of the absorbers and, in some cases, of the detailed flux distribution near the perturbation. The results from one calculational method, the source-sink approach, were compared with the data from selected experiments. (author)

  12. Design of a five-band terahertz perfect metamaterial absorber using two resonators

    Science.gov (United States)

    Meng, Tianhua; Hu, Dan; Zhu, Qiaofen

    2018-05-01

    We present a polarization-insensitive five-band terahertz perfect metamaterial absorber composed of two metallic circular rings and a metallic ground film separated by a dielectric layer. The calculated results show that the absorber has five distinctive absorption bands whose peaks are greater than 99% on average. The physical origin of the absorber originates from the combination of dipolar, hexapolar, and surface plasmon resonance of the patterned metallic structure, which is different from the work mechanism of previously reported absorbers. In addition, the influence of the structural parameters on the absorption spectra is analyzed to further confirm the origin of the five-band absorption peaks. The proposed absorber has potential applications in terahertz imaging, refractive index sensing, and material detecting.

  13. NASA's Bio-Inspired Acoustic Absorber Concept

    Science.gov (United States)

    Koch, L. Danielle

    2017-01-01

    Transportation noise pollutes our worlds cities, suburbs, parks, and wilderness areas. NASAs fundamental research in aviation acoustics is helping to find innovative solutions to this multifaceted problem. NASA is learning from nature to develop the next generation of quiet aircraft.The number of road vehicles and airplanes has roughly tripled since the 1960s. Transportation noise is audible in nearly all the counties across the US. Noise can damage your hearing, raise your heart rate and blood pressure, disrupt your sleep, and make communication difficult. Noise pollution threatens wildlife when it prevents animals from hearing prey, predators, and mates. Noise regulations help drive industry to develop quieter aircraft. Noise standards for aircraft have been developed by the International Civil Aviation Organization and adopted by the US Federal Aviation Administration. The US National Park Service is working with the Federal Aviation Administration to try to balance the demand for access to the parks and wilderness areas with preservation of the natural soundscape. NASA is helping by conceptualizing quieter, more efficient aircraft of the future and performing the fundamental research to make these concepts a reality someday. Recently, NASA has developed synthetic structures that can absorb sound well over a wide frequency range, and particularly below 1000 Hz, and which mimic the acoustic performance of bundles of natural reeds. We are adapting these structures to control noise on aircraft, and spacecraft. This technology might be used in many other industrial or architectural applications where acoustic absorbers have tight constraints on weight and thickness, and may be exposed to high temperatures or liquids. Information about this technology is being made available through reports and presentations available through the NASA Technical Report Server, http:ntrs.nasa.gov. Organizations who would like to collaborate with NASA or commercialize NASAs technology

  14. Energy scavenging strain absorber: application to kinetic dielectric elastomer generator

    Science.gov (United States)

    Jean-Mistral, C.; Beaune, M.; Vu-Cong, T.; Sylvestre, A.

    2014-03-01

    Dielectric elastomer generators (DEGs) are light, compliant, silent energy scavengers. They can easily be incorporated into clothing where they could scavenge energy from the human kinetic movements for biomedical applications. Nevertheless, scavengers based on dielectric elastomers are soft electrostatic generators requiring a high voltage source to polarize them and high external strain, which constitutes the two major disadvantages of these transducers. We propose here a complete structure made up of a strain absorber, a DEG and a simple electronic power circuit. This new structure looks like a patch, can be attached on human's wear and located on the chest, knee, elbow… Our original strain absorber, inspired from a sailing boat winch, is able to heighten the external available strain with a minimal factor of 2. The DEG is made of silicone Danfoss Polypower and it has a total area of 6cm per 2.5cm sustaining a maximal strain of 50% at 1Hz. A complete electromechanical analytical model was developed for the DEG associated to this strain absorber. With a poling voltage of 800V, a scavenged energy of 0.57mJ per cycle is achieved with our complete structure. The performance of the DEG can further be improved by enhancing the imposed strain, by designing a stack structure, by using a dielectric elastomer with high dielectric permittivity.

  15. Effects of absorbed hydrogen on crack-tip ductility in the welded A516 steel

    International Nuclear Information System (INIS)

    Khattak, M.A.; Haslan, M.H.; Tamin, M.N.

    2007-01-01

    Effects of absorbed hydrogen on structure and properties of welded A516 Grade-70 steel are investigated. Emphasis is placed on ductility measure of the crack-tip plastic zone under Mode I loading. Specimens are cathodically charged in a cell with dilute sulphuric acid and corrosion inhibitor with uniform charging current density of 20 mA/ cm 2 and at different exposure time. Results indicate a change from coarse- to fine-grained microstructures in the weld region and heat affected zone (HAZ) of hydrogen-charged specimen. Well-defined ferrite-pearlite bands in the base metal are transformed into coarse-grain structure. Hardness variation along radial distance indicates higher values towards the center of the bar, possibly due to faster diffusion rate but limited solubility of hydrogen. Load-COD responses indicate that slow, stable crack propagation occurred in both base metal and HAZ. The measured provisional fracture toughness, K Q is higher for HAZ than that for the base metal. The toughness values decreases significantly for the initial three hours of hydrogen charging. The tensile fracture region in the immediate fatigue pre-crack tip forms a triangular (rough) zone due to limited constraint to free surface deformation in the thin specimen. Fracture surface of HAZ is dominated by intergranular fracture with localized cleavage facets. (author)

  16. Transmission line model and fields analysis of metamaterial absorber in the terahertz band.

    Science.gov (United States)

    Wen, Qi-Ye; Xie, Yun-Song; Zhang, Huai-Wu; Yang, Qing-Hui; Li, Yuan-Xun; Liu, Ying-Li

    2009-10-26

    Metamaterial (MM) absorber is a novel device to provide near-unity absorption to electromagnetic wave, which is especially important in the terahertz (THz) band. However, the principal physics of MM absorber is still far from being understood. In this work, a transmission line (TL) model for MM absorber was proposed, and with this model the S-parameters, energy consumption, and the power loss density of the absorber were calculated. By this TL model, the asymmetric phenomenon of THz absorption in MM absorber is unambiguously demonstrated, and it clarifies that strong absorption of this absorber under studied is mainly related to the LC resonance of the split-ring-resonator structure. The distribution of power loss density in the absorber indicates that the electromagnetic wave is firstly concentrated into some specific locations of the absorber and then be strongly consumed. This feature as electromagnetic wave trapper renders MM absorber a potential energy converter. Based on TL model, some design strategies to widen the absorption band were also proposed for the purposes to extend its application areas.

  17. A biomimetic absorbent for removal of trace level persistent organic pollutants from water

    International Nuclear Information System (INIS)

    Liu Huijuan; Qu Jiuhui; Dai Ruihua; Ru Jia; Wang Zijian

    2007-01-01

    A novel biomimetic absorbent containing the lipid triolein was developed for removing persistent organic pollutants (POPs) from water. The structural characteristics of the absorbent were obtained by SEM and a photoluminescence method. Under optimum preparation conditions, triolein was perfectly embedded in the cellulose acetate (CA) spheres, the absorbent was stable and no triolein leaked into the water. Dieldrin, endrin, aldrin and heptachlor epoxide were effectively removed by the CA-triolein absorbent in laboratory batch experiments. This suggests that CA-triolein absorbent may serve as a good absorbent for those selected POPs. Triolein in the absorbent significantly increased the absorption capacity, and lower residual concentrations of POPs were achieved when compared to the use of cellulose acetate absorbent. The absorption rate for lipophilic pollutants was very fast and exhibited some relationship with the octanol-water partition coefficient of the analyte. The absorption mechanism is discussed in detail. - Triolein-embedded absorbent was developed and it could remove lipophilic pollutants from water effectively

  18. An innovative MRE absorber with double natural frequencies for wide frequency bandwidth vibration absorption

    International Nuclear Information System (INIS)

    Sun, Shuaishuai; Yang, Jian; Li, Weihua; Alici, Gursel; Deng, Huaxia; Du, Haiping; Yan, Tianhong

    2016-01-01

    A new design of adaptive tuned vibration absorber was proposed in this study for vibration reduction. The innovation of the new absorber is the adoption of the eccentric mass on the top of the multilayered magnetorheological elastomer (MRE) structure so that this proposed absorber has two vibration modes: one in the torsional direction and the other in translational direction. This property enables the absorber to expand its effective bandwidth and to be more capable of reducing the vibrations especially dealing with those vibrations with multi-frequencies. The innovative MRE absorber was designed and tested on a horizontal vibration table. The test results illustrate that the MRE absorber realized double natural frequencies, both of which are controllable. Inertia’s influence on the dynamic behavior of the absorber is also investigated in order to guide the design of the innovative MRE absorber. Additionally, the experimentally obtained natural frequencies coincide with the theoretical data, which sufficiently verifies the feasibility of this new design. The last part in terms of the vibration absorption ability also proves that both of these two natural frequencies play a great role in absorbing vibration energy. (paper)

  19. Development of Zinc Tin Nitride for Application as an Earth Abundant Photovoltaic Absorber

    Science.gov (United States)

    Fioretti, Angela N.

    In recent years, many new potential absorber materials based on earth-abundant and non-toxic elements have been predicted. These materials, often made in thin film form and known to absorb light 10-1000 times more e ciently than crystalline silicon, could lower module cost and enable broader solar deployment. One such material is zinc tin nitride (ZnSnN 2), a II-IV-nitride analog of the III-nitride materials, which was identified as a suitable solar absorber due to its direct bandgap, large absorption coefficient, and disorder-driven bandgap tunability. Despite these desirable properties, initial attempts at synthesis resulted in degenerate n-type carrier density. Computational work on the point defect formation energies for this material revealed three donor defects were likely the cause; specifically SnZn antisites, VN sites, and ON substitutions. Given this framework, a defect-driven hypothesis was proposed as a starting point for the present work: if each donor defect could be addressed by tuning deposition parameters, n-type degeneracy may be defeated. By using combinatorial co- sputtering to grow compositionally-graded thin film samples, n-type carrier density was reduced by two orders of magnitude compared to state-of-the-art. This reduction in carrier density was observed for zinc-rich samples, which supported the defect-driven hypothesis initially proposed. These results and their implications are the topic of Chapter 2. Further carrier density control in zinc-rich ZTN was achieved via hydrogen incorporation and post-growth annealing. This strategy was hypothesized to operate by passivating acceptor defects to avoid self-compensation, which were then activated by hydrogen drive- out upon annealing. Carrier density was reduced another order of magnitude using this technique, which is presented in Chapter 3. After defeating n-type degeneracy, a deeper understanding of the electronic structure was pursued. Photoluminescence (PL) was used to study electronic

  20. Design of a nonlinear torsional vibration absorber

    Science.gov (United States)

    Tahir, Ammaar Bin

    Tuned mass dampers (TMD) utilizing linear spring mechanisms to mitigate destructive vibrations are commonly used in practice. A TMD is usually tuned for a specific resonant frequency or an operating frequency of a system. Recently, nonlinear vibration absorbers attracted attention of researchers due to some potential advantages they possess over the TMDs. The nonlinear vibration absorber, or the nonlinear energy sink (NES), has an advantage of being effective over a broad range of excitation frequencies, which makes it more suitable for systems with several resonant frequencies, or for a system with varying excitation frequency. Vibration dissipation mechanism in an NES is passive and ensures that there is no energy backflow to the primary system. In this study, an experimental setup of a rotational system has been designed for validation of the concept of nonlinear torsional vibration absorber with geometrically induced cubic stiffness nonlinearity. Dimensions of the primary system have been optimized so as to get the first natural frequency of the system to be fairly low. This was done in order to excite the dynamic system for torsional vibration response by the available motor. Experiments have been performed to obtain the modal parameters of the system. Based on the obtained modal parameters, the design optimization of the nonlinear torsional vibration absorber was carried out using an equivalent 2-DOF modal model. The optimality criterion was chosen to be maximization of energy dissipation in the nonlinear absorber attached to the equivalent 2-DOF system. The optimized design parameters of the nonlinear absorber were tested on the original 5-DOF system numerically. A comparison was made between the performance of linear and nonlinear absorbers using the numerical models. The comparison showed the superiority of the nonlinear absorber over its linear counterpart for the given set of primary system parameters as the vibration energy dissipation in the former is

  1. Method of absorbing UF6 from gaseous mixtures in alkamine absorbents

    International Nuclear Information System (INIS)

    Lafferty, R.H.; Smiley, S.H.; Radimer, K.J.

    1976-01-01

    A method is described for recovering UF 6 from gaseous mixtures by absorption in a liquid. The liquid absorbent must have a relatively low viscosity and at least one component of the absorbent is an alkamine having less than 3 carbon atoms bonded to the amino nitrogen, less than 2 of the carbon atoms other than those bonded to the amino nitrogen are free of the hydroxy radical and precipitate the absorbed uranium from the absorbent. At least one component of the absorbent is chosen from the group consisting of ethanolamine, diethanolamine, and 3-methyl-3-amino-propane-diol-1,2

  2. Why muscle is an efficient shock absorber.

    Directory of Open Access Journals (Sweden)

    Michael A Ferenczi

    Full Text Available Skeletal muscles power body movement by converting free energy of ATP hydrolysis into mechanical work. During the landing phase of running or jumping some activated skeletal muscles are subjected to stretch. Upon stretch they absorb body energy quickly and effectively thus protecting joints and bones from impact damage. This is achieved because during lengthening, skeletal muscle bears higher force and has higher instantaneous stiffness than during isometric contraction, and yet consumes very little ATP. We wish to understand how the actomyosin molecules change their structure and interaction to implement these physiologically useful mechanical and thermodynamical properties. We monitored changes in the low angle x-ray diffraction pattern of rabbit skeletal muscle fibers during ramp stretch compared to those during isometric contraction at physiological temperature using synchrotron radiation. The intensities of the off-meridional layer lines and fine interference structure of the meridional M3 myosin x-ray reflection were resolved. Mechanical and structural data show that upon stretch the fraction of actin-bound myosin heads is higher than during isometric contraction. On the other hand, the intensities of the actin layer lines are lower than during isometric contraction. Taken together, these results suggest that during stretch, a significant fraction of actin-bound heads is bound non-stereo-specifically, i.e. they are disordered azimuthally although stiff axially. As the strong or stereo-specific myosin binding to actin is necessary for actin activation of the myosin ATPase, this finding explains the low metabolic cost of energy absorption by muscle during the landing phase of locomotion.

  3. Selective wave-transmitting electromagnetic absorber through composite metasurface

    Science.gov (United States)

    Sun, Zhiwei; Zhao, Junming; Zhu, Bo; Jiang, Tian; Feng, Yijun

    2017-11-01

    Selective wave-transmitting absorbers which have one or more narrow transmission bands inside a wide absorption band are often demanded in wireless communication and radome applications for reducing the coupling between different systems, improving anti-jamming capability, and reducing antennas' radar cross section. Here we propose a feasible method that utilizing composite of two metasurfaces with different polarization dependent characteristics, one works as electromagnetic polarization rotator and the other as a wideband polarization dependent electromagnetic wave absorber. The polarization rotator produces a cross polarization output in the wave-transmitting band, while preserves the polarization of the incidence outside the band. The metasurface absorber works for certain linear polarization with a much wider absorption band covering the wave-transmitting frequency. When combining these two metasurfaces properly, the whole structure behaves as a wideband absorber with a certain frequency transmission window. The proposal may be applied in radome designs to reduce the radar cross section of antenna or improving the electromagnetic compatibility in communication devices.

  4. Performance of a Multifunctional Space Evaporator-Absorber-Radiator (SEAR)

    Science.gov (United States)

    Izenson, Michael G.; Chen, Weibo; Phillips, Scott; Chepko, Ariane; Bue, Grant; Quinn, Gregory

    2014-01-01

    The Space Evaporator-Absorber-Radiator (SEAR) is a nonventing thermal control subsystem that combines a Space Water Membrane Evaporator (SWME) with a Lithium Chloride Absorber Radiator (LCAR). The LCAR is a heat pump radiator that absorbs water vapor produced in the SWME. Because of the very low water vapor pressure at equilibrium with lithium chloride solution, the LCAR can absorb water vapor at a temperature considerably higher than the SWME, enabling heat rejection sufficient for most EVA activities by thermal radiation from a relatively small area radiator. Prior SEAR prototypes used a flexible LCAR that was designed to be installed on the outer surface of a portable life support system (PLSS) backpack. This paper describes a SEAR subsystem that incorporates a very compact LCAR. The compact, multifunctional LCAR is built in the form of thin panels that can also serve as the PLSS structural shell. We designed and assembled a 2 ft² prototype LCAR based on this design and measured its performance in thermal vacuum tests when supplied with water vapor by a SWME. These tests validated our models for SEAR performance and showed that there is enough area available on the PLSS backpack shell to enable rejection of metabolic heat from the LCAR. We used results of these tests to assess future performance potential and suggest approaches for integrating the SEAR system with future space suits.

  5. Research of Control System and Fault Diagnosis of the Sound-absorbing Board Production Line

    Directory of Open Access Journals (Sweden)

    Yanjun Xiao

    2014-08-01

    Full Text Available Programmable Logic Controller is the core of the control system of the sound- absorbing board production line and the design of fault diagnosis is an essential modules in the sound- absorbing board production line. The article discourses the application of PLC in the control system of the production line, and designs the methods of grading treatment and prevention of troubles, which makes use of PLC’S logic functions. The method has good expansibility, and has good guidance to the fault diagnosis in other automation equipments.

  6. On the definition of absorbed dose

    International Nuclear Information System (INIS)

    Grusell, Erik

    2015-01-01

    Purpose: The quantity absorbed dose is used extensively in all areas concerning the interaction of ionizing radiation with biological organisms, as well as with matter in general. The most recent and authoritative definition of absorbed dose is given by the International Commission on Radiation Units and Measurements (ICRU) in ICRU Report 85. However, that definition is incomplete. The purpose of the present work is to give a rigorous definition of absorbed dose. Methods: Absorbed dose is defined in terms of the random variable specific energy imparted. A random variable is a mathematical function, and it cannot be defined without specifying its domain of definition which is a probability space. This is not done in report 85 by the ICRU, mentioned above. Results: In the present work a definition of a suitable probability space is given, so that a rigorous definition of absorbed dose is possible. This necessarily includes the specification of the experiment which the probability space describes. In this case this is an irradiation, which is specified by the initial particles released and by the material objects which can interact with the radiation. Some consequences are discussed. Specific energy imparted is defined for a volume, and the definition of absorbed dose as a point function involves the specific energy imparted for a small mass contained in a volume surrounding the point. A possible more precise definition of this volume is suggested and discussed. Conclusions: The importance of absorbed dose motivates a proper definition, and one is given in the present work. No rigorous definition has been presented before. - Highlights: • A stringent definition of absorbed dose is given. • This requires the definition of an irradiation and a suitable probability space. • A stringent definition is important for an understanding of the concept absorbed dose

  7. Radioactive iodine absorbing properties of tetrathiafulvalene

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Tomiyasu; Nakamura, Asao (Ajinomoto Co. Inc., Kawasaki, Kanagawa (Japan). Central Research Labs.); Nogawa, Norio; Oohashi, Kunio; Morikawa, Naotake

    1989-05-01

    For the purpose of searching some effective absorbents of gaseous radioactive iodine, 16 substances considered as having an affinity for iodine were investigated with regular iodine and /sup 125/I. In a preliminary survey, only tetrathiafulvalene (TTF) was found to have satisfactory absorbing properties comparable to activated charcoal. A further detailed comparison of the properties between TTF and activated charcoal led us to the conclusion that the former has more preferable properties as absorbent of radioactive iodine than the latter in all points studied. The results are summarized as follows: (1) The absorption of iodine on TTF in atmosphere was about twice as much as that on activated charcoal. Desorption of iodine from saturatedly absorbed iodine on TTF was practically negligible except trace amount of initial desorption, while that on activated charcoal was considerable (3%/50h) even in the air at room temperature. (2) Absorbed amount of iodine on activated charcoal decreased with increasing gaseous iodine concentration, air flow rate, on humidity of flowing-air. On the other hand, those factors scarcely affected that on TTF. Under an air flow rate of 1m/s, activated charcoal absorbs only 80% of iodine, while TTF absorbs more than 99%. (3) In flowing-air saturated with water vapor, iodine absorbed on activated charcoal was gradually liberated although by small amount (0.08%/100h), while that on TTF was much more stable for a long period (0.004%/100h). As a conclusion, TTF is considered to be useful as a quite effective radioactive iodine absorbent, especially in the case where protection from radioactive iodine should be serious, though it is expensive now. (author).

  8. Estimation of Absorbed Dose in Occlusal Radiography

    International Nuclear Information System (INIS)

    Yoo, Young Ah; Choi, Karp Shick; Lee, Sang Han

    1990-01-01

    The purpose of this study was to estimate absorbed dose of each important anatomic site of phantom (RT-210 Head and Neck Section R, Humanoid Systems Co., U.S.A.) head in occlusal radiography. X-radiation dosimetry at 12 anatomic sites in maxillary anterior topography, maxillary posterior topography, mandibular anterior cross-section, mandibular posterior cross-section, mandibular anterior topographic, mandibular posterior topographic occlusal projection was performed with calcium sulfate thermoluminescent dosimeters under 70 Kvp and 15 mA, 1/4 second (8 inch cone ) and 1 second (16 inch cone) exposure time. The results obtained were as follows: Skin surface produced highest absorbed dose ranged between 3264 mrad and 4073 mrad but there was little difference between projections. In maxillary anterior topographic occlusal radiography, eyeballs, maxillary sinuses, and pituitary gland sites produced higher absorbed doses than those of other sites. In maxillary posterior topographic occlusal radiography, exposed eyeball site and exposed maxillary sinus site produced high absorbed doses. In mandibular anterior cross-sectional occlusal radiography, all sites were produced relatively low absorbed dose except eyeball sites. In Mandibular posterior cross-sectional occlusal radiography, exposed eyeball site and exposed maxillary sinus site were produced relatively higher absorbed doses than other sites. In mandibular anterior topographic occlusal radiography, maxillary sinuses, submandibular glands, and thyroid gland sites produced high absorbed doses than other sites. In mandibular posterior topographic occlusal radiography, submandibular gland site of the exposed side produced high absorbed dose than other sites and eyeball site of the opposite side produced relatively high absorbed dose.

  9. Radioactive iodine absorbing properties of tetrathiafulvalene

    International Nuclear Information System (INIS)

    Ito, Tomiyasu; Nakamura, Asao; Nogawa, Norio; Oohashi, Kunio; Morikawa, Naotake.

    1989-01-01

    For the purpose of searching some effective absorbents of gaseous radioactive iodine, 16 substances considered as having an affinity for iodine were investigated with regular iodine and 125 I. In a preliminary survey, only tetrathiafulvalene (TTF) was found to have satisfactory absorbing properties comparable to activated charcoal. A further detailed comparison of the properties between TTF and activated charcoal led us to the conclusion that the former has more preferable properties as absorbent of radioactive iodine than the latter in all points studied. The results are summarized as follows: (1) The absorption of iodine on TTF in atmosphere was about twice as much as that on activated charcoal. Desorption of iodine from saturatedly absorbed iodine on TTF was practically negligible except trace amount of initial desorption, while that on activated charcoal was considerable (3%/50h) even in the air at room temperature. (2) Absorbed amount of iodine on activated charcoal decreased with increasing gaseous iodine concentration, air flow rate, on humidity of flowing-air. On the other hand, those factors scarcely affected that on TTF. Under an air flow rate of 1m/s, activated charcoal absorbs only 80% of iodine, while TTF absorbs more than 99%. (3) In flowing-air saturated with water vapor, iodine absorbed on activated charcoal was gradually liberated although by small amount (0.08%/100h), while that on TTF was much more stable for a long period (0.004%/100h). As a conclusion, TTF is considered to be useful as a quite effective radioactive iodine absorbent, especially in the case where protection from radioactive iodine should be serious, though it is expensive now. (author)

  10. Tailored Buckling Microlattices as Reusable Light-Weight Shock Absorbers.

    Science.gov (United States)

    Frenzel, Tobias; Findeisen, Claudio; Kadic, Muamer; Gumbsch, Peter; Wegener, Martin

    2016-07-01

    Structures and materials absorbing mechanical (shock) energy commonly exploit either viscoelasticity or destructive modifications. Based on a class of uniaxial light-weight geometrically nonlinear mechanical microlattices and using buckling of inner elements, either a sequence of snap-ins followed by irreversible hysteretic - yet repeatable - self-recovery or multistability is achieved, enabling programmable behavior. Proof-of-principle experiments on three-dimensional polymer microstructures are presented. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. DETERMINATION OF ENERGY LOSSES BY SHOCK ABSORBER IN A FREIGHT CAR AT CRASH MODE

    Directory of Open Access Journals (Sweden)

    Ya. V. Bolzhelarskyi

    2016-08-01

    Full Text Available Purpose. The purpose of this work is to determine the energy losses in the shock absorber of the freight car whose wheel-set moves in the derailed state on the track panel depending on the axle load and structural parameters of spring suspension. Methodology. On the basis of spring suspension construction analysis and operating principle of the friction shock absorber of the freight car bogie the authors provide the method for determining the energy absorbed by it. The calculations take the maximum values of the absorber elements displacement and the regulatory values of spring suspension parameters. Findings. The authors obtained the calculated formula for determining the energy absorbed by shock absorber for regulation-set mounting schemes of elastic bogie elements depending on the axial load. The mentioned curves are parabolic. Originality. The work examines the crash mode of the wheel-set movement on the track panels after its derailment. It is shown that the energy dissipation in the shock absorbers is the reason for increase in resistance to rolling stock movement. The formulas for calculating the amount of energy dissipated in the shock absorber with a maximum displacement of its elements are derived. This energy depends on the axle load and structural parameters of spring suspension. Practical value. The proposed method allows setting the value of the additional resistance to motion that occurs in crash mode which makes it possible to increase the accuracy of traction calculations.

  12. Space Evaporator-Absorber-Radiator (SEAR)

    Science.gov (United States)

    Bue, Grant C.; Stephan, Ryan; Hodgson, Ed; Izenson, Mike; Chen, Weibo

    2012-01-01

    A system for non-venting thermal control for spacesuits was built by integrating two previously developed technologies, namely NASA s Spacesuit Water Membrane Evaporator (SWME), and Creare s flexible version of the Lithium Chloride Absorber Radiator (LCAR). This SEAR system was tested in relevant thermal vacuum conditions. These tests show that a 1 m2 radiator having about three times as much absorption media as in the test article would be required to support a 7 hour spacewalk. The serial flow arrangement of the LCAR of the flexible version proved to be inefficient for venting non-condensable gas (NCG). A different LCAR packaging arrangement was conceived wherein the Portable Life Support System (PLSS) housing would be made with a high-strength carbon fiber composite honeycomb, the cells of which would be filled with the chemical absorption media. This new packaging reduces the mass and volume impact of the SEAR on the Portable Life Support System (PLSS) compared to the flexible design. A 0.2 sq m panel with flight-like honeycomb geometry is being constructed and will be tested in thermal and thermal vacuum conditions. Design analyses forecast improved system performance and improved NCG control. A flight-like regeneration system also is also being built and tested. Design analyses for the structurally integrated prototype as well as the earlier test data show that SEAR is not only practical for spacesuits but also has useful applications in spacecraft thermal control.

  13. Multifunctional Space Evaporator-Absorber-Radiator (SEAR)

    Science.gov (United States)

    Bue, Grant C.; Hodgson, Ed; Izenson, Mike; Chen, Weibo

    2013-01-01

    A system for non-venting thermal control for spacesuits was built by integrating two previously developed technologies, namely NASA's Spacesuit Water Membrane Evaporator (SWME), and Creare's flexible version of the Lithium Chloride Absorber Radiator (LCAR). This SEAR system was tested in relevant thermal vacuum conditions. These tests show that a 1 sq m radiator having about three times as much absorption media as in the test article would be required to support a 7 hour spacewalk. The serial flow arrangement of the LCAR of the flexible version proved to be inefficient for venting non-condensable gas (NCG). A different LCAR packaging arrangement was conceived wherein the Portable Life Support System (PLSS) housing would be made with a high-strength carbon fiber composite honeycomb, the cells of which would be filled with the chemical absorption media. This new packaging reduce the mass and volume impact of the SEAR on the Portable Life Support System (PLSS) compared to the flexible design. A 0.2 sq m panel with flight-like honeycomb geometry is being constructed and will be tested in thermal and thermal vacuum conditions. Design analyses forecast improved system performance and improved NCG control. A flight-like regeneration system also is also being built and tested. Design analyses for the structurally integrated prototype as well as the earlier test data show that SEAR is not only practical for spacesuits but also has useful applications in spacecraft thermal control.

  14. Semiconductor saturable absorbers for ultrafast terahertz signals

    DEFF Research Database (Denmark)

    Hoffmann, Matthias C.; Turchinovich, Dmitry

    2010-01-01

    states, due to conduction band onparabolicity and scattering into satellite valleys in strong THz fields. Saturable absorber parameters, such as linear and nonsaturable transmission, and saturation fluence, are extracted by fits to a classic saturable absorber model. Further, we observe THz pulse......We demonstrate saturable absorber behavior of n-type semiconductors GaAs, GaP, and Ge in the terahertz THz frequency range at room temperature using nonlinear THz spectroscopy. The saturation mechanism is based on a decrease in electron conductivity of semiconductors at high electron momentum...

  15. Absorbed dose by a CMOS in radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Borja H, C. G.; Valero L, C. Y.; Guzman G, K. A.; Banuelos F, A.; Hernandez D, V. M.; Vega C, H. R. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Calle Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico); Paredes G, L. C., E-mail: candy_borja@hotmail.com [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2011-10-15

    Absorbed dose by a complementary metal oxide semiconductor (CMOS) circuit as part of a pacemaker, has been estimated using Monte Carlo calculations. For a cancer patient who is a pacemaker carrier, scattered radiation could damage pacemaker CMOS circuits affecting patient's health. Absorbed dose in CMOS circuit due to scattered photons is too small and therefore is not the cause of failures in pacemakers, but neutron calculations shown an absorbed dose that could cause damage in CMOS due to neutron-hydrogen interactions. (Author)

  16. A highly efficient graphene oxide absorber for Q-switched Nd:GdVO4 lasers

    International Nuclear Information System (INIS)

    Wang Yonggang; Wen Xiaoming; Tang Jau; Chen, Hou Ren; Hsieh, Wen Feng

    2011-01-01

    We demonstrated that graphene oxide material could be used as a highly efficient saturable absorber for the Q-switched Nd:GdVO 4 laser. A novel and low-cost graphene oxide (GO) absorber was fabricated by a vertical evaporation technique and high viscosity of polyvinyl alcohol (PVA) aqueous solution. A piece of GO/PVA absorber, a piece of round quartz, and an output coupler mirror were combined to be a sandwich structure passive component. Using such a structure, 104 ns pulses and 1.22 W average output power were obtained with the maximum pulse energy at 2 µJ and a slope efficiency of 17%.

  17. Geodynamic evolution of the Pan-African lower crust in Sri Lanka : structural and petrological investigations into a high-grade gneiss terrain

    NARCIS (Netherlands)

    Kriegsman, L.

    1993-01-01

    Some main objectives of present-day geological research are to assess the role of the lower crust in collision and extensional tectonics and to unravel the mechanism and timing of crustal growth. Both objectives require input from the study of high-grade gneiss terrains, notably data concerning

  18. Spacesuit Evaporator-Absorber-Radiator (SEAR)

    Data.gov (United States)

    National Aeronautics and Space Administration — The primary goal is to build and test a rigid Lithium Chloride Absorber Radiator (LCAR) coupon based on honeycomb geometry that would be applicable for EVA and...

  19. Full-flow absorbers. Every centimetre counts

    Energy Technology Data Exchange (ETDEWEB)

    Berner, Joachim

    2012-07-01

    New absorbers with a maximised area for heat exchange with the thermal medium are significantly more efficient than the presently typical designs. Both the industry and researchers are working to revive an old idea. (orig.)

  20. Quantitative neutron radiography using neutron absorbing honeycomb

    International Nuclear Information System (INIS)

    Tamaki, Masayoshi; Oda, Masahiro; Takahashi, Kenji; Ohkubo, Kohei; Tasaka, Kanji; Tsuruno, Akira; Matsubayashi, Masahito.

    1993-01-01

    This investigation concerns quantitative neutron radiography and computed tomography by using a neutron absorbing honeycomb collimator. By setting the neutron absorbing honeycomb collimator between object and imaging system, neutrons scattered in the object were absorbed by the honeycomb material and eliminated before coming to the imaging system, but the neutrons which were transmitted the object without interaction could reach the imaging system. The image by purely transmitted neutrons gives the quantitative information. Two honeycombs were prepared with coating of boron nitride and gadolinium oxide and evaluated for the quantitative application. The relation between the neutron total cross section and the attenuation coefficient confirmed that they were in a fairly good agreement. Application to quantitative computed tomography was also successfully conducted. The new neutron radiography method using the neutron-absorbing honeycomb collimator for the elimination of the scattered neutrons improved remarkably the quantitativeness of the neutron radiography and computed tomography. (author)

  1. An ultra-broadband multilayered graphene absorber

    KAUST Repository

    Amin, Muhammad

    2013-01-01

    An ultra-broadband multilayered graphene absorber operating at terahertz (THz) frequencies is proposed. The absorber design makes use of three mechanisms: (i) The graphene layers are asymmetrically patterned to support higher order surface plasmon modes that destructively interfere with the dipolar mode and generate electromagnetically induced absorption. (ii) The patterned graphene layers biased at different gate voltages backedup with dielectric substrates are stacked on top of each other. The resulting absorber is polarization dependent but has an ultra-broadband of operation. (iii) Graphene\\'s damping factor is increased by lowering its electron mobility to 1000cm 2=Vs. Indeed, numerical experiments demonstrate that with only three layers, bandwidth of 90% absorption can be extended upto 7THz, which is drastically larger than only few THz of bandwidth that can be achieved with existing metallic/graphene absorbers. © 2013 Optical Society of America.

  2. Phase Space Exchange in Thick Wedge Absorbers

    Energy Technology Data Exchange (ETDEWEB)

    Neuffer, David [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2017-01-01

    The problem of phase space exchange in wedge absorbers with ionization cooling is discussed. The wedge absorber exchanges transverse and longitudinal phase space by introducing a position-dependent energy loss. In this paper we note that the wedges used with ionization cooling are relatively thick, so that single wedges cause relatively large changes in beam phase space. Calculation methods adapted to such “thick wedge” cases are presented, and beam phase-space transformations through such wedges are discussed.

  3. Semiconductor saturable absorbers for ultrafast THz signals

    DEFF Research Database (Denmark)

    Hoffmann, Matthias C.; Turchinovich, Dmitry

    We demonstrate saturable absorber behavior of n-type semiconductors in the THz frequency range using nonlinear THz spectroscopy. Further, we observe THz pulse shortening and increase of the group refractive index at high field strengths.......We demonstrate saturable absorber behavior of n-type semiconductors in the THz frequency range using nonlinear THz spectroscopy. Further, we observe THz pulse shortening and increase of the group refractive index at high field strengths....

  4. Actual behaviour of a ball vibration absorber

    Czech Academy of Sciences Publication Activity Database

    Pirner, Miroš

    2002-01-01

    Roč. 90, č. 8 (2002), s. 987-1005 ISSN 0167-6105 R&D Projects: GA ČR(CZ) GV103/96/K034 Institutional support: RVO:68378297 Keywords : TV towers * wind-excited vibrations * vibration absorbers * pendulum absorber Subject RIV: JM - Building Engineering Impact factor: 0.513, year: 2002 http://www.sciencedirect.com/science/article/pii/S0167610502002155#

  5. A Wedge Absorber Experiment at MICE

    Energy Technology Data Exchange (ETDEWEB)

    Neuffer, David [Fermilab; Mohayai, Tanaz [IIT, Chicago; Rogers, Chris [Rutherford; Snopok, Pavel [IIT, Chicago; Summers, Don [Mississippi U.

    2017-05-01

    Emittance exchange mediated by wedge absorbers is required for longitudinal ionization cooling and for final transverse emittance minimization for a muon collider. A wedge absorber within the MICE beam line could serve as a demonstration of the type of emittance exchange needed for 6-D cooling, including the configurations needed for muon colliders, as well as configurations for low-energy muon sources. Parameters for this test are explored in simulation and possible experimental configurations with simulated results are presented.

  6. Grading options for western hemlock "pulpwood" logs from southeastern Alaska.

    Science.gov (United States)

    David W. Green; Kent A. McDonald; John Dramm; Kenneth Kilborn

    Properties and grade yield are estimated for structural lumber produced from No. 3, No. 4, and low-end No. 2 grade western hemlock logs of the type previously used primarily for the production of pulp chips. Estimates are given for production in the Structural Framing, Machine Stress Rating, and Laminating Stock grading systems. The information shows that significant...

  7. Performance of an absorbing concentrating solar collectors

    International Nuclear Information System (INIS)

    Imadojemu, H.

    1990-01-01

    This paper reports on a comparison of the efficiency of an absorbing fluid parabolic trough concentrating solar collector and a traditional concentrating collector that was made. In the absorbing fluid collector, black liquid flows through a glass tube absorber while the same black liquid flows through a selective black coated copper tube absorber while the same black fluid flows through a selective black coated copper tube absorber in the traditional collector. After a careful study of the properties of available black liquids, a mixture of water and black ink was chosen as the black absorbing medium or transfer fluid. In the black liquid glass collector there is a slightly improved efficiency based on beam radiation as a result of the direct absorption process and an increase in the effective transmittance absorptance. At worst the efficiency of this collector equals that of the traditional concentrating collector when the efficiency is based on total radiation. The collector's reflecting surfaces were made of aluminum sheet, parabolic line focus and with cylindrical receivers. The ease of manufacture and reduced cost per unit energy collected, in addition to the clean and pollution free mode of energy conversion, makes it very attractive

  8. Asymmetric acoustic transmission in graded beam

    Energy Technology Data Exchange (ETDEWEB)

    Jing, Li, E-mail: lj94172350@hotmail.com [School of Mechanical Engineering and State Key laboratory for Strength and Vibration of Mechanical Structures, Xi’an Jiaotong University, Xi’an, Shaanxi 710049 (China); Wu, Jiu Hui, E-mail: ejhwu@mail.xjtu.edu.cn [School of Mechanical Engineering and State Key laboratory for Strength and Vibration of Mechanical Structures, Xi’an Jiaotong University, Xi’an, Shaanxi 710049 (China); Guan, Dong; Lu, Kuan [School of Mechanical Engineering and State Key laboratory for Strength and Vibration of Mechanical Structures, Xi’an Jiaotong University, Xi’an, Shaanxi 710049 (China); Gao, Nansha [School of Marine Science and Technology, Northwestern Polytechnical University, Xi’an, Shaanxi 710072 (China); Songhua, Cao [School of Mechanical Engineering and State Key laboratory for Strength and Vibration of Mechanical Structures, Xi’an Jiaotong University, Xi’an, Shaanxi 710049 (China)

    2016-12-01

    We demonstrate the dynamic effective material parameters and vibration performance of a graded beam. The structure of the beam was composed of several unit cells with different fill factors. The dispersion relations and energy band structures of each unit cell were calculated using the finite element method (FEM). The dynamic effective material parameters in each unit cell of the graded beam were determined by the dispersion relations and energy band structures. Longitudinal wave propagation was investigated using a numerical method and FEM. The results show that the graded beam allows asymmetric acoustic transmission over a wide range of frequencies.

  9. Fifth Grade Elementary Students' Conceptions of Earthquakes

    Science.gov (United States)

    Savasci, Funda; Uluduz, Hatice

    2013-01-01

    This study intends to investigate the fifth grade students' conceptions of earthquakes. Twenty two grade 5 students (11-12 years old) from five different elementary schools in Istanbul voluntarily participated in the study. Data were collected from semi-structured interviews with each participant. Six interview questions were designed by…

  10. Contraction of graded su(2) algebra

    International Nuclear Information System (INIS)

    Patra, M.K.; Tripathy, K.C.

    1989-01-01

    The Inoenu-Wigner contraction scheme is extended to Lie superalgebras. The structure and representations of extended BRS algebra are obtained from contraction of the graded su(2) algebra. From cohomological consideration, we demonstrate that the graded su(2) algebra is the only superalgebra which, on contraction, yields the full BRS algebra. (orig.)

  11. Wireless device for activation of an underground shock wave absorber

    Science.gov (United States)

    Chikhradze, M.; Akhvlediani, I.; Bochorishvili, N.; Mataradze, E.

    2011-10-01

    The paper describes the mechanism and design of the wireless device for activation of energy absorber for localization of blast energy in underground openings. The statistics shows that the greatest share of accidents with fatal results associate with explosions in coal mines due to aero-methane and/or air-coal media explosion. The other significant problem is terrorist or accidental explosions in underground structures. At present there are different protective systems to reduce the blast energy. One of the main parts of protective Systems is blast Identification and Registration Module. The works conducted at G. Tsulukidze Mining Institute of Georgia enabled to construct the wireless system of explosion detection and mitigation of shock waves. The system is based on the constant control on overpressure. The experimental research continues to fulfill the system based on both threats, on the constant control on overpressure and flame parameters, especially in underground structures and coal mines. Reaching the threshold value of any of those parameters, the system immediately starts the activation. The absorber contains a pyrotechnic device ensuring the discharge of dispersed water. The operational parameters of wireless device and activation mechanisms of pyrotechnic element of shock wave absorber are discussed in the paper.

  12. On arbitrarily graded rings

    Indian Academy of Sciences (India)

    58

    paper is devoted to the study of arbitrary rings graded through arbitrary sets. .... which recover certain multiplicative relations among the homogeneous components ... instance the case in which the grading set A is an Abelian group, where the ...

  13. Graded manifolds and supermanifolds

    International Nuclear Information System (INIS)

    Batchelor, M.

    1984-01-01

    In this paper, a review is presented on graded manifolds and supermanifolds. Many theorems, propositions, corrollaries, etc. are given with proofs or sketch proofs. Graded manifolds, supereuclidian space, Lie supergroups, etc. are dealt with

  14. ZED-2 experiments on the effect of a Co absorber rod on an NRU loop

    International Nuclear Information System (INIS)

    Arbique, G.M.; French, P.M.

    1983-02-01

    A series of experiments has been performed in ZED-2 to measure the perturbing effects of an NRU cobalt absorber rod on a simulated NRU loop site containing graded enrichment U0 2 fuel. The objective of the measurements was to provide data useful in validating NRU reactor physics codes. Using a simulated NRU lattice containing a simulated NRU loop site and an asymmetrically placed Co absorber rod, measurements were made of: (a) reactivity effects, as measured by critical height changes, associated with voiding the loop and stepped insertion of the Co absorber rod, (b) flux perturbations at the simulated loop site and throughout the lattice induced by the Co rod, (c) Westcott r√T/Tsub(o) values throughout the lattice

  15. Design principles for morphologies of antireflection patterns for solar absorbing applications.

    Science.gov (United States)

    Moon, Yoon-Jong; Na, Jin-Young; Kim, Sun-Kyung

    2015-07-01

    Two-dimensional surface texturing is a widespread technology for imparting broadband antireflection, yet its design rules are not completely understood. The dependence of the reflectance spectrum of a periodically patterned glass film on various structural parameters (e.g., pitch, height, shape, and fill factor) has been investigated by means of full-vectorial numerical simulations. An average weighted reflectivity accounting for the AM1.5G solar spectrum (λ=300-1000  nm) was sinusoidally modulated by a rod pattern's height, and was minimized for pitches of 400-600 nm. When a rationally optimized cone pattern was used, the average weighted reflectivity was less than 0.5%, for incident angles of up to 40° off normal. The broadband antireflection of a cone pattern was reproduced well by a graded refractive index film model corresponding to its geometry, with the addition of a diffraction effect resulting from its periodicity. The broadband antireflection ability of optimized cone patterns is not limited to the glass material, but rather is generically applicable to other semiconductor materials, including Si and GaAs. The design rules developed herein represent a key step in the development of light-absorbing devices, such as solar cells.

  16. GRADE Equity Guidelines 3

    DEFF Research Database (Denmark)

    Welch, Vivian A; Akl, Elie A; Pottie, Kevin

    2017-01-01

    OBJECTIVE: The aim of this paper is to describe a conceptual framework for how to consider health equity in the GRADE (Grading Recommendations Assessment and Development Evidence) guideline development process. STUDY DESIGN AND SETTING: Consensus-based guidance developed by the GRADE working grou...

  17. Method of absorbance correction in a spectroscopic heating value sensor

    Science.gov (United States)

    Saveliev, Alexei; Jangale, Vilas Vyankatrao; Zelepouga, Sergeui; Pratapas, John

    2013-09-17

    A method and apparatus for absorbance correction in a spectroscopic heating value sensor in which a reference light intensity measurement is made on a non-absorbing reference fluid, a light intensity measurement is made on a sample fluid, and a measured light absorbance of the sample fluid is determined. A corrective light intensity measurement at a non-absorbing wavelength of the sample fluid is made on the sample fluid from which an absorbance correction factor is determined. The absorbance correction factor is then applied to the measured light absorbance of the sample fluid to arrive at a true or accurate absorbance for the sample fluid.

  18. A new laboratory-scale experimental facility for detailed aerothermal characterizations of volumetric absorbers

    Science.gov (United States)

    Gomez-Garcia, Fabrisio; Santiago, Sergio; Luque, Salvador; Romero, Manuel; Gonzalez-Aguilar, Jose

    2016-05-01

    This paper describes a new modular laboratory-scale experimental facility that was designed to conduct detailed aerothermal characterizations of volumetric absorbers for use in concentrating solar power plants. Absorbers are generally considered to be the element with the highest potential for efficiency gains in solar thermal energy systems. The configu-ration of volumetric absorbers enables concentrated solar radiation to penetrate deep into their solid structure, where it is progressively absorbed, prior to being transferred by convection to a working fluid flowing through the structure. Current design trends towards higher absorber outlet temperatures have led to the use of complex intricate geometries in novel ceramic and metallic elements to maximize the temperature deep inside the structure (thus reducing thermal emission losses at the front surface and increasing efficiency). Although numerical models simulate the conjugate heat transfer mechanisms along volumetric absorbers, they lack, in many cases, the accuracy that is required for precise aerothermal validations. The present work aims to aid this objective by the design, development, commissioning and operation of a new experimental facility which consists of a 7 kWe (1.2 kWth) high flux solar simulator, a radiation homogenizer, inlet and outlet collector modules and a working section that can accommodate volumetric absorbers up to 80 mm × 80 mm in cross-sectional area. Experimental measurements conducted in the facility include absorber solid temperature distributions along its depth, inlet and outlet air temperatures, air mass flow rate and pressure drop, incident radiative heat flux, and overall thermal efficiency. In addition, two windows allow for the direct visualization of the front and rear absorber surfaces, thus enabling full-coverage surface temperature measurements by thermal imaging cameras. This paper presents the results from the aerothermal characterization of a siliconized silicon

  19. Warm Absorber Diagnostics of AGN Dynamics

    Science.gov (United States)

    Kallman, Timothy

    Warm absorbers and related phenomena are observable manifestations of outflows or winds from active galactic nuclei (AGN) that have great potential value. Understanding AGN outflows is important for explaining the mass budgets of the central accreting black hole, and also for understanding feedback and the apparent co-evolution of black holes and their host galaxies. In the X-ray band warm absorbers are observed as photoelectric absorption and resonance line scattering features in the 0.5-10 keV energy band; the UV band also shows resonance line absorption. Warm absorbers are common in low luminosity AGN and they have been extensively studied observationally. They may play an important role in AGN feedback, regulating the net accretion onto the black hole and providing mechanical energy to the surroundings. However, fundamental properties of the warm absorbers are not known: What is the mechanism which drives the outflow?; what is the gas density in the flow and the geometrical distribution of the outflow?; what is the explanation for the apparent relation between warm absorbers and the surprising quasi-relativistic 'ultrafast outflows' (UFOs)? We propose a focused set of model calculations that are aimed at synthesizing observable properties of warm absorber flows and associated quantities. These will be used to explore various scenarios for warm absorber dynamics in order to answer the questions in the previous paragraph. The guiding principle will be to examine as wide a range as possible of warm absorber driving mechanisms, geometry and other properties, but with as careful consideration as possible to physical consistency. We will build on our previous work, which was a systematic campaign for testing important class of scenarios for driving the outflows. We have developed a set of tools that are unique and well suited for dynamical calculations including radiation in this context. We also have state-of-the-art tools for generating synthetic spectra, which are

  20. Preparation of Ag/SiO{sub 2} near-infrared absorbers using the combination of sputtering and spin-coating depositions

    Energy Technology Data Exchange (ETDEWEB)

    Liau, Leo Chau-Kuang, E-mail: lckliau@saturn.yzu.edu.tw [Department of Chemical Engineering and Materials Science, Yuan Ze University, Chung-Li 320, Taiwan (China); Lai, Guo-Bin [Department of Chemical Engineering and Materials Science, Yuan Ze University, Chung-Li 320, Taiwan (China); Juang, Rei-Cheng; Chang, Bing-Hung [Green Energy and Environmental Laboratories, Industrial Technology Research Institute, Hsinchu 300, Taiwan (China); Yang, Thomas Chun-Kuang [Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, Taipei 106, Taiwan (China)

    2015-03-02

    This study presents the design and fabrication of near-infrared (NIR) absorbers constructed in multilayer structures using Ag and SiO{sub 2} materials. The absorbers, consisting of Ag and SiO{sub 2} films, were fabricated using sputtering and spin-coating approaches, respectively. The fabricated absorbing devices were evaluated using ultraviolet–visible-NIR spectra. Results revealed that the structure of the Ag/SiO{sub 2}/Ag films exhibited an NIR absorbing effect. The absorbing properties were substantially influenced by the fabrication parameters and the thickness of the multilayer films. Furthermore, the NIR absorbing performance improved significantly when the SiO{sub 2} layer was annealed at 300 °C before the deposition of the top Ag film. Additionally, the absorptance of the absorbers was affected by the thickness of the top Ag layer. The long-term stability of the multilayer absorber was tested and verified based on absorptance data analysis. The NIR absorbing performance can be further improved using the optimal device design of the film thickness and by fabricating additional Ag/SiO{sub 2} layers. - Highlights: • Ag/SiO{sub 2} near-infrared absorbers were designed and fabricated. • The absorbing performance was greatly influenced by the fabrication schemes. • The optimal fabrication process of the absorber was obtained. • The long-term stability of the absorber was verified.

  1. Microwave absorptions of ultrathin conductive films and designs of frequency-independent ultrathin absorbers

    International Nuclear Information System (INIS)

    Li, Sucheng; Anwar, Shahzad; Lu, Weixin; Hang, Zhi Hong; Hou, Bo; Shen, Mingrong; Wang, Chin-Hua

    2014-01-01

    We study the absorption properties of ultrathin conductive films in the microwave regime, and find a moderate absorption effect which gives rise to maximal absorbance 50% if the sheet (square) resistance of the film meets an impedance matching condition. The maximal absorption exhibits a frequency-independent feature and takes place on an extremely subwavelength scale, the film thickness. As a realistic instance, ∼5 nm thick Au film is predicted to achieve the optimal absorption. In addition, a methodology based on metallic mesh structure is proposed to design the frequency-independent ultrathin absorbers. We perform a design of such absorbers with 50% absorption, which is verified by numerical simulations

  2. Absorbed power distribution in the whole-body system of a tractor operator

    Directory of Open Access Journals (Sweden)

    Jacek Kromulski

    2016-06-01

    The concept of absorbed power as a measurement for evaluation of WBV exposure opens a new area for research. The important character of absorbed power is that it has physical significance and therefore can be measured as well as computed analytically. The absorbed power relates to dissipation of energy attributed to relative motions of the visco-elastic tissues, muscles and skeletal system, which under prolonged exposures could lead to physical damage in the musculoskeletal system. A structural model of the human operator allows determination of the dynamic characteristics of the model, and study of the energy flow between the elements of the model.

  3. Graded gauge theory

    International Nuclear Information System (INIS)

    Kerner, R.

    1983-01-01

    The mathematical background for a graded extension of gauge theories is investigated. After discussing the general properties of graded Lie algebras and what may serve as a model for a graded Lie group, the graded fiber bundle is constructed. Its basis manifold is supposed to be the so-called superspace, i.e. the product of the Minkowskian space-time with the Grassmann algebra spanned by the anticommuting Lorentz spinors; the vertical subspaces tangent to the fibers are isomorphic with the graded extension of the SU(N) Lie algebra. The connection and curvature are defined then on this bundle; the two different gradings are either independent of each other, or may be unified in one common grading, which is equivalent to the choice of the spin-statistics dependence. The Yang-Mills lagrangian is investigated in the simplified case. The conformal symmetry breaking is discussed, as well as some other physical consequences of the model. (orig.)

  4. In As{sub 1–x}Sb{sub x} heteroepitaxial structures on compositionally graded GaInSb and AlGaInSb buffer layers

    Energy Technology Data Exchange (ETDEWEB)

    Guseynov, R. R.; Tanriverdiyev, V. A. [National Academy of Sciences of Azerbaijan, Institute of Physics (Azerbaijan); Kipshidze, G., E-mail: gela.kishidze@stonybrook.ede [Stony Brook, Stony Brook University (United States); Aliyeva, Ye. N.; Aliguliyeva, Kh. V.; Abdullayev, N. A., E-mail: abnadir@mail.ru; Mamedov, N. T. [National Academy of Sciences of Azerbaijan, Institute of Physics (Azerbaijan)

    2017-04-15

    Unrelaxed InAs{sub 1–x}Sb{sub x} (x = 0.43 and 0.38) alloy layers are produced by molecular-beam epitaxy on compositionally graded GaInSb and AlGaInSb buffer layers. The high quality of the thin films produced is confirmed by the results of high-resolution X-ray diffraction analysis and micro-Raman studies. The twomode type of transformation of the phonon spectra of InAs{sub 1–x}Sb{sub x} alloys is established.

  5. Neutron absorbed dose in a pacemaker CMOS

    International Nuclear Information System (INIS)

    Borja H, C. G.; Guzman G, K. A.; Valero L, C.; Banuelos F, A.; Hernandez D, V. M.; Vega C, H. R.; Paredes G, L.

    2012-01-01

    The neutron spectrum and the absorbed dose in a Complementary Metal Oxide Semiconductor (CMOS), has been estimated using Monte Carlo methods. Eventually a person with a pacemaker becomes an oncology patient that must be treated in a linear accelerator. Pacemaker has integrated circuits as CMOS that are sensitive to intense and pulsed radiation fields. Above 7 MV therapeutic beam is contaminated with photoneutrons that could damage the CMOS. Here, the neutron spectrum and the absorbed dose in a CMOS cell was calculated, also the spectra were calculated in two point-like detectors in the room. Neutron spectrum in the CMOS cell shows a small peak between 0.1 to 1 MeV and a larger peak in the thermal region, joined by epithermal neutrons, same features were observed in the point-like detectors. The absorbed dose in the CMOS was 1.522 x 10 -17 Gy per neutron emitted by the source. (Author)

  6. Neutron absorbed dose in a pacemaker CMOS

    Energy Technology Data Exchange (ETDEWEB)

    Borja H, C. G.; Guzman G, K. A.; Valero L, C.; Banuelos F, A.; Hernandez D, V. M.; Vega C, H. R. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico); Paredes G, L., E-mail: fermineutron@yahoo.com [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2012-06-15

    The neutron spectrum and the absorbed dose in a Complementary Metal Oxide Semiconductor (CMOS), has been estimated using Monte Carlo methods. Eventually a person with a pacemaker becomes an oncology patient that must be treated in a linear accelerator. Pacemaker has integrated circuits as CMOS that are sensitive to intense and pulsed radiation fields. Above 7 MV therapeutic beam is contaminated with photoneutrons that could damage the CMOS. Here, the neutron spectrum and the absorbed dose in a CMOS cell was calculated, also the spectra were calculated in two point-like detectors in the room. Neutron spectrum in the CMOS cell shows a small peak between 0.1 to 1 MeV and a larger peak in the thermal region, joined by epithermal neutrons, same features were observed in the point-like detectors. The absorbed dose in the CMOS was 1.522 x 10{sup -17} Gy per neutron emitted by the source. (Author)

  7. Tribology Aspect of Rubber Shock Absorbers Development

    Directory of Open Access Journals (Sweden)

    M. Banić

    2013-09-01

    Full Text Available Rubber is a very flexible material with many desirable properties Which enable its broad use in engineering practice. Rubber or rubber-metal springs are widely used as anti-vibration or anti-shock components in technical systems. Rubber-metal springs are usually realized as a bonded assembly, however especially in shock absorbers, it is possible to realize free contacts between rubber and metal parts. In previous research it authors was observed that friction between rubber and metal in such case have a significant influence on the damping characteristics of shock absorber. This paper analyzes the development process of rubber or rubber-metal shock absorbers realized free contacts between the constitutive parts, starting from the design, construction, testing and operation, with special emphasis on the development of rubber-metal springs for the buffing and draw gear of railway vehicles.

  8. Quantum walk with one variable absorbing boundary

    International Nuclear Information System (INIS)

    Wang, Feiran; Zhang, Pei; Wang, Yunlong; Liu, Ruifeng; Gao, Hong; Li, Fuli

    2017-01-01

    Quantum walks constitute a promising ingredient in the research on quantum algorithms; consequently, exploring different types of quantum walks is of great significance for quantum information and quantum computation. In this study, we investigate the progress of quantum walks with a variable absorbing boundary and provide an analytical solution for the escape probability (the probability of a walker that is not absorbed by the boundary). We simulate the behavior of escape probability under different conditions, including the reflection coefficient, boundary location, and initial state. Moreover, it is also meaningful to extend our research to the situation of continuous-time and high-dimensional quantum walks. - Highlights: • A novel scheme about quantum walk with variable boundary is proposed. • The analytical results of the survival probability from the absorbing boundary. • The behavior of survival probability under different boundary conditions. • The influence of different initial coin states on the survival probability.

  9. A wideband absorber for television studios

    Science.gov (United States)

    Baird, M. D. M.

    The acoustic treatment in BBC television has taken various forms to date, all of which have been relatively expensive, some of which provide inadequate absorption. An investigation has been conducted into the possibilities of producing a new type of wideband absorber which would be more economic, also taking installation time into account, than earlier designs. This Report describes the absorption coefficient measurements made on various combinations of materials, from which a wideband sound absorber has been developed. The absorber works efficiently between 50 Hz and 10 kHz, is simple and easy to construct using readily available materials, and is fire resistant. The design lends itself, if necessary, to on-site fine tuning, and savings in the region of 50 percent can be achieved in terms of cost and space with respect to previous designs.

  10. Pneumatic Adaptive Absorber: Mathematical Modelling with Experimental Verification

    Directory of Open Access Journals (Sweden)

    Grzegorz Mikułowski

    2016-01-01

    Full Text Available Many of mechanical energy absorbers utilized in engineering structures are hydraulic dampers, since they are simple and highly efficient and have favourable volume to load capacity ratio. However, there exist fields of applications where a threat of toxic contamination with the hydraulic fluid contents must be avoided, for example, food or pharmacy industries. A solution here can be a Pneumatic Adaptive Absorber (PAA, which is characterized by a high dissipation efficiency and an inactive medium. In order to properly analyse the characteristics of a PAA, an adequate mathematical model is required. This paper proposes a concept for mathematical modelling of a PAA with experimental verification. The PAA is considered as a piston-cylinder device with a controllable valve incorporated inside the piston. The objective of this paper is to describe a thermodynamic model of a double chamber cylinder with gas migration between the inner volumes of the device. The specific situation considered here is that the process cannot be defined as polytropic, characterized by constant in time thermodynamic coefficients. Instead, the coefficients of the proposed model are updated during the analysis. The results of the experimental research reveal that the proposed mathematical model is able to accurately reflect the physical behaviour of the fabricated demonstrator of the shock absorber.

  11. Low back pain: conservative treatment with artificial shock absorbers.

    Science.gov (United States)

    Wosk, J; Voloshin, A S

    1985-03-01

    A new method of conservative treatment for low back pain (LBP) was studied by follow-up investigation of 382 patients during the last five years. The attempt to reduce repetitive impulsive intervertebral impact in the troublesome S1-L5-4 area by significant improvement of the foot's attenuational capacity through artificial viscoelastic shock absorbing was prompted by the authors' work on decreased capability of LBP spines to attenuate axially propagated walking stresses. Viscoelastic shoe inserts were used in addition to light flexible shoes as artificial shock absorbing devices. Maximal amplitudes of bone oscillation during walking were reduced by about 40% by the viscoelastic inserts. Rapid and surprisingly significant improvement of pain syndrome and patient mobility occurred in about 80% of the patients. The accelerographic patterns recorded on a sacrum of patient with LBP were unusual for a healthy subject; they usually disappeared after treatment in LBP cases. Results suggested that poor walking impact attenuation was a true cause for prolonging intervertebral structures overstrain and consequent degeneration. It seemed logical that as spine damage could be explained primarily by prolonged impulsive overstrain, treatment must include viscoelastic inserts which increase foot shock absorbing capacity and help cushion the spine.

  12. Absorbed dose in fibrotic microenvironment models employing Monte Carlo simulation

    International Nuclear Information System (INIS)

    Zambrano Ramírez, O.D.; Rojas Calderón, E.L.; Azorín Vega, E.P.; Ferro Flores, G.; Martínez Caballero, E.

    2015-01-01

    The presence or absence of fibrosis and yet more, the multimeric and multivalent nature of the radiopharmaceutical have recently been reported to have an effect on the radiation absorbed dose in tumor microenvironment models. Fibroblast and myofibroblast cells produce the extracellular matrix by the secretion of proteins which provide structural and biochemical support to cells. The reactive and reparative mechanisms triggered during the inflammatory process causes the production and deposition of extracellular matrix proteins, the abnormal excessive growth of the connective tissue leads to fibrosis. In this work, microenvironment (either not fibrotic or fibrotic) models composed of seven spheres representing cancer cells of 10 μm in diameter each with a 5 μm diameter inner sphere (cell nucleus) were created in two distinct radiation transport codes (PENELOPE and MCNP). The purpose of creating these models was to determine the radiation absorbed dose in the nucleus of cancer cells, based on previously reported radiopharmaceutical retain (by HeLa cells) percentages of the 177 Lu-Tyr 3 -octreotate (monomeric) and 177 Lu-Tyr 3 -octreotate-AuNP (multimeric) radiopharmaceuticals. A comparison in the results between the PENELOPE and MCNP was done. We found a good agreement in the results of the codes. The percent difference between the increase percentages of the absorbed dose in the not fibrotic model with respect to the fibrotic model of the codes PENELOPE and MCNP was found to be under 1% for both radiopharmaceuticals. (authors)

  13. The MIRD method of estimating absorbed dose

    International Nuclear Information System (INIS)

    Weber, D.A.

    1991-01-01

    The estimate of absorbed radiation dose from internal emitters provides the information required to assess the radiation risk associated with the administration of radiopharmaceuticals for medical applications. The MIRD (Medical Internal Radiation Dose) system of dose calculation provides a systematic approach to combining the biologic distribution data and clearance data of radiopharmaceuticals and the physical properties of radionuclides to obtain dose estimates. This tutorial presents a review of the MIRD schema, the derivation of the equations used to calculate absorbed dose, and shows how the MIRD schema can be applied to estimate dose from radiopharmaceuticals used in nuclear medicine

  14. Method for manufacture of neutron absorbing articles

    International Nuclear Information System (INIS)

    Owens, D.

    1980-01-01

    A one-step curing method for the manufacture of a neutron absorbing article which comprises irreversibly curing, in desired article form, a form-retaining mixture of boron carbide particles, curable phenolic resin in solid state and in particula te form and a minor proportion of a liquid medium, which boils at a temperature below 200*c., at an elevated temperature so as to obtain bonding of the irreversibly cured phenolic polymer resulting to the boron carbide particles and production of the neutron absorbing article in desired form

  15. LINEAR MODEL FOR NON ISOSCELES ABSORBERS.

    Energy Technology Data Exchange (ETDEWEB)

    BERG,J.S.

    2003-05-12

    Previous analyses have assumed that wedge absorbers are triangularly shaped with equal angles for the two faces. In this case, to linear order, the energy loss depends only on the position in the direction of the face tilt, and is independent of the incoming angle. One can instead construct an absorber with entrance and exit faces facing rather general directions. In this case, the energy loss can depend on both the position and the angle of the particle in question. This paper demonstrates that and computes the effect to linear order.

  16. Optically Modulated Multiband Terahertz Perfect Absorber

    DEFF Research Database (Denmark)

    Seren, Huseyin R.; Keiser, George R.; Cao, Lingyue

    2014-01-01

    response of resonant metamaterials continues to be a challengingendeavor. Resonant perfect absorbers have flourished as one of the mostpromising metamaterial devices with applications ranging from power har-vesting to terahertz imaging. Here, an optically modulated resonant perfectabsorber is presented....... Utilizing photo-excited free carriers in silicon padsplaced in the capacitive gaps of split ring resonators, a dynamically modu-lated perfect absorber is designed and fabricated to operate in reflection.Large modulation depth (38% and 91%) in two absorption bands (with 97%and 92% peak absorption...

  17. Microstructured extremely thin absorber solar cells

    DEFF Research Database (Denmark)

    Biancardo, Matteo; Krebs, Frederik C

    2007-01-01

    In this paper we present the realization of extremely thin absorber (ETA) solar cells employing conductive glass substrates functionalized with TiO2 microstructures produced by embossing. Nanocrystalline or compact TiO2 films on Indium doped tin oxide (ITO) glass substrates were embossed by press......In this paper we present the realization of extremely thin absorber (ETA) solar cells employing conductive glass substrates functionalized with TiO2 microstructures produced by embossing. Nanocrystalline or compact TiO2 films on Indium doped tin oxide (ITO) glass substrates were embossed...

  18. Multilayer detector for skin absorbed dose measuring

    International Nuclear Information System (INIS)

    Osanov, D.P.; Panova, V.P.; Shaks, A.I.

    1985-01-01

    A method for skin dosimetry based on utilization of multilayer detectors and permitting to estimate distribution of absorbed dose by skin depth is described. The detector represents a set of thin sensitive elements separated by tissue-equivalent absorbers. Quantitative evaluation and forecasting the degree of radiation injury of skin are determined by the formula based on determination of the probability of the fact that cells are not destroyed and they can divide further on. The given method ensures a possibility of quantitative evaluation of radiobiological effect and forecasting clinical consequences of skin irradiation by results of corresponding measurements of dose by means of the miultilayer detector

  19. Structural analysis of co-evaporated In{sub 2}S{sub 3} and In{sub 2}S{sub 3}:V for solar cell absorber applications

    Energy Technology Data Exchange (ETDEWEB)

    Waegele, Leonard A.; Rata, Diana; Scheer, Roland [Institute of Physics, Martin Luther University Halle-Wittenberg, Von-Danckelmann-Platz 3, 06120 Halle (Saale) (Germany); Gurieva, Galina [Department Structure and Dynamics of Energy Materials, Helmholtz-Zentrum Berlin, Hahn-Meitner-Platz 1, 14109 Berlin (Germany)

    2017-06-15

    In this study we use co-evaporation to grow In{sub 2}S{sub 3} thin films on glass substrates and X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) to analyse the structural properties of annealed In{sub 2}S{sub 3} and V-doped In{sub 2}S{sub 3} for intermediate band solar cell application. We find co-evaporated In{sub 2}S{sub 3} to be polycrystalline on float glass and with improved crystallinity after annealing in S-atmosphere. We confirm that excessive incorporation of vanadium into the host structure is possible without formation of secondary crystalline phases. The analysis indicates a reduced crystalline quality after V doping. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. Optimization of X-ray Absorbers for TES Microcalorimeters

    Science.gov (United States)

    Iyomoto, Naoko; Sadleir, John E.; Figueroa-Feliciano, Enectali; Saab, Tarek; Bandler, Simon; Kilbourne, Caroline; Chervenak, James; Talley, Dorothy; Finkbeiner, Fred; Brekosky, Regis

    2004-01-01

    We have investigated the thermal, electrical, and structural properties of Bi and BiCu films that are being developed as X-ray absorbers for transition-edge sensor (TES) microcalorimeter arrays for imaging X-ray spectroscopy. Bi could be an ideal material for an X-ray absorber due to its high X-ray stopping power and low heat capacity, but it has a low thermal conductivity, which can result in position dependence of the pulses in the absorber. In order to improve the thermal conductivity, we added Cu layers in between the Bi layers. We measured electrical and thermal conductivities of the films around 0.1 K(sub 1) the operating temperature of the TES calorimeter, to examine the films and to determine the optimal thickness of the Cu layer. From the electrical conductivity measurements, we found that the Cu is more resistive on the Bi than on a Si substrate. Together with an SEM picture of the Bi surface, we concluded that the rough surface of the Bi film makes the Cu layer resistive when the Cu layer is not thick enough t o fill in the roughness. From the thermal conductivity measurements, we determined the thermal diffusion constant to be 2 x l0(exp 3) micrometers squared per microsecond in a film that consists of 2.25 micrometers of Bi and 0.1 micrometers of Cu. We measured the position dependence in the film and found that its thermal diffusion constant is too low to get good energy resolution, because of the resistive Cu layer and/or possibly a very high heat capacity of our Bi films. We show plans to improve the thermal diffusion constant in our BiCu absorbers.

  1. The Cooling of a Liquid Absorber using a Small Cooler

    International Nuclear Information System (INIS)

    Baynham, D.E.; Bradshaw, T.W.; Green, M.A.; Ishimoto, S.; Liggins, N.

    2005-01-01

    This report discusses the use of small cryogenic coolers for cooling the Muon Ionization Cooling Experiment (MICE) liquid cryogen absorbers. Since the absorber must be able contain liquid helium as well liquid hydrogen, the characteristics of the available 4.2 K coolers are used here. The issues associated with connecting two-stage coolers to liquid absorbers are discussed. The projected heat flows into an absorber and the cool-down of the absorbers using the cooler are presented. The warm-up of the absorber is discussed. Special hydrogen safety issues that may result from the use of a cooler on the absorbers are also discussed

  2. An Overview on Impact Behaviour and Energy Absorption of Collapsible Metallic and Non-Metallic Energy Absorbers used in Automotive Applications

    Science.gov (United States)

    Shinde, R. B.; Mali, K. D.

    2018-04-01

    Collapsible impact energy absorbers play an important role of protecting automotive components from damage during collision. Collision of the two objects results into the damage to one or both of them. Damage may be in the form of crack, fracture and scratch. Designers must know about how the material and object behave under impact event. Owing to above reasons different types of collapsible impact energy absorbers are developed. In the past different studies were undertaken to improve such collapsible impact energy absorbers. This article highlights such studies on common shapes of collapsible impact energy absorber and their impact behaviour under the axial compression. The literature based on studies and analyses of effects of different geometrical parameters on the crushing behaviour of impact energy absorbers is presented in detail. The energy absorber can be of different shape such as circular tube, square tube, and frustums of cone and pyramids. The crushing behaviour of energy absorbers includes studies on crushing mechanics, modes of deformation, energy absorbing capacity, effect on peak and mean crushing load. In this work efforts are made to cover major outcomes from past studies on such behavioural parameters. Even though the major literature reviewed is related to metallic energy absorbers, emphasis is also laid on covering literature on use of composite tube, fiber metal lamination (FML) member, honeycomb plate and functionally graded thickness (FGT) tube as a collapsible impact energy absorber.

  3. Electrochemical Corrosion Testing of Neutron Absorber Materials

    International Nuclear Information System (INIS)

    Tedd Lister; Ron Mizia; Arnold Erickson; Tammy Trowbridge

    2007-01-01

    This report summarizes the results of crevice-corrosion tests for six alloys in solutions representative of ionic compositions inside the Yucca Mountain waste package should a breech occur. The alloys in these tests are Neutronit A978a (ingot metallurgy, hot rolled), Neutrosorb Plus 304B4 Grade Ab (powder metallurgy, hot rolled), Neutrosorb Plus 304B5 Grade Ab (powder metallurgy, hot rolled), Neutrosorb Plus 304B6 Grade Ab (powder metallurgy, hot rolled), Ni-Cr-Mo-Gd alloy2 (ingot metallurgy, hot rolled), and Alloy 22 (ingot metallurgy, hot rolled)

  4. Rapid prototyping tool for tuning of vibration absorbers; Rapid-Prototyping-Tool zur Abstimmung von Schwingungstilgern

    Energy Technology Data Exchange (ETDEWEB)

    Marienfeld, P.M.; Karkosch, H.J. [ContiTech Vibration Control GmbH, Hannover (Germany); Bohn, C. [Technische Univ. Clausthal (Germany); Svaricek, F. [Univ. der Bundeswehr Muenchen (Germany); Knake-Langhorst, S. [Deutsches Zentrum fuer Luft- und Raumfahrt, Braunschweig (Germany)

    2008-07-01

    In the automotive industry passive vibration absorbers are a well established method to reduce structural vibrations in automotive vehicles. Designing a vibration absorber consists of selecting its mechanical properties. Usually extensive tests are necessary with different absorbers in the vehicle and subjective as well as objective evaluation of the results. This requires hardware modifications between different tests. In this paper, an approach is proposed that can assist in the development of vibration absorbers. It is based on tuning an active vibration control system such that it reproduces the behavior of a specified vibration absorber. This behavior can then be changed electronically without modifying the hardware. Two different control approaches are compared. In the first approach, the apparent physical properties of a vibration absorber are directly modified through acceleration, velocity or displacement feedback. In the second approach, a desired dynamic mass transfer function for the vibration absorber is prescribed and an H2-norm optimal model matching problem is solved. Experimental results obtained with this approach are presented. (orig.)

  5. Moving core beam energy absorber and converter

    Science.gov (United States)

    Degtiarenko, Pavel V.

    2012-12-18

    A method and apparatus for the prevention of overheating of laser or particle beam impact zones through the use of a moving-in-the-coolant-flow arrangement for the energy absorbing core of the device. Moving of the core spreads the energy deposition in it in 1, 2, or 3 dimensions, thus increasing the effective cooling area of the device.

  6. Absorbance and fluorescence studies on porphyrin Nanostructures ...

    African Journals Online (AJOL)

    The aim of this work was to study some photophysical properties of PNR for application as light harvester in dye sensitized solar cells. These properties included absorbance, fluorescence, and fluorescence quantum yield and lifetime. The results of Transmission Electron Microscope (TEM) images showed the formation of ...

  7. Proposal concerning the absorbed dose conversion factor

    Energy Technology Data Exchange (ETDEWEB)

    Shiragai, A [National Inst. of Radiological Sciences, Chiba (Japan)

    1978-03-01

    New definitions of the absorbed dose conversion factors Csub(lambda) and Csub(E) are proposed. The absorbed dose in water is given by the product of absorbed dose conversion factor, exposure calibration factor, ionisation chamber reading, cap displacement correction factor and perturbation correction factor. At exposure calibration the material of the build-up cap must be the same as that of the chamber wall. An ionisation chamber of which the wall material is water-equivalent or air-equivalent may be used. In the latter case the wall must be thin. For these two cases absorbed dose conversion factors are introduced and it is recommended that either of the two sets should be adopted. Furthermore, if the chamber wall is neither water- nor air-equivalent, the factor by which these currently defined values should be multiplied is also given: again the wall must be thin. The ICRU definitions of Csub(lambda) and Csub(E) are inconsistent, as recently pointed out, while the definitions presented here are consistent.

  8. Fabrication of high efficacy selective solar absorbers

    CSIR Research Space (South Africa)

    Tile, N

    2012-03-01

    Full Text Available High efficiency tandem selective solar absorber materials of carbon in nickel oxide (C-NiO) composite were fabricated on an aluminium substrate using a simple and cost effective sol-gel process. The process involved preparation of carbon and nickel...

  9. Strain absorbent modules for cavity filling

    Energy Technology Data Exchange (ETDEWEB)

    1981-04-01

    Strain absorbent modules made from weldmesh panels and helical steel binders can be used, together with timber packing, to support the roof and sides of cavities instead of softwood and hardwood nogs. A description of these modules and a series of load tests and underground trials carried out on the modules is given.

  10. Measuring the absorbed radioactivity during a flight

    International Nuclear Information System (INIS)

    2002-01-01

    This paper presents the new system SIEVERT developed by the General Direction of the Civil Aviation (DGAC) to measure the radiations doses absorbed from cosmic radiation. The system is available on the Internet site: www.sievert-system.org. (A.L.B.)

  11. Electromagnetic and microwave absorbing properties of hollow ...

    Indian Academy of Sciences (India)

    bandwidth below −10 dB and minimum RL decrease with increasing thickness of HCNSs/paraffin composites. Keywords. Nanomaterials; nanospheres; CVD; electric; magnetic; microwave absorption properties. 1. Introduction. In recent years, microwave absorbing materials have attracted considerable attention because it ...

  12. Coupler for nuclear reactor absorber rods

    International Nuclear Information System (INIS)

    Kerz, K.

    1984-01-01

    A coupler is described for absorber rods being suspended during operation of nuclear reactors which includes plurality of actuating elements being movable for individually and jointly releasing the coupler, the movement of each of the actuating elements for releasing the coupler being independently controllable

  13. Flexible metamaterial absorbers for stealth applications at terahertz frequencies

    DEFF Research Database (Denmark)

    Iwaszczuk, Krzysztof; Strikwerda, Andrew; Fan, K.

    2012-01-01

    We have wrapped metallic cylinders with strongly absorbing metamaterials. These resonant structures, which are patterned on flexible substrates, smoothly coat the cylinder and give it an electromagnetic response designed to minimize its radar cross section. We compare the normal-incidence, small......-beam reflection coefficient with the measurement of the far-field bistatic radar cross section of the sample, using a quasi-planar THz wave with a beam diameter significantly larger than the sample dimensions. In this geometry we demonstrate a near-400-fold reduction of the radar cross section at the design...

  14. An Electrochromatography Chip with Integrated Waveguides for UV Absorbance Detection

    DEFF Research Database (Denmark)

    Gustafsson, Omar; Mogensen, Klaus Bo; Ohlsson, Pelle Daniel

    2008-01-01

    A silicon-based microchip for electrochromatographic separations is presented. Apart from a microfluidic network, the microchip has integrated UV-transparent waveguides for detection and integrated couplers for optical fibers on the chip, yielding the most complete chromatography microchip to date...... to the waveguides. The entire oxidized silicon microchip structure is sealed with a glass lid. Reversed phase electrochromatographic separation of three neutral compounds is demonstrated using UV absorbance detection at 254 nm. Baseline separation of the analytes is achieved in less than two minutes....

  15. Graded tensor calculus

    International Nuclear Information System (INIS)

    Scheunert, M.

    1982-10-01

    We develop a graded tensor calculus corresponding to arbitrary Abelian groups of degrees and arbitrary commutation factors. The standard basic constructions and definitions like tensor products, spaces of multilinear mappings, contractions, symmetrization, symmetric algebra, as well as the transpose, adjoint, and trace of a linear mapping, are generalized to the graded case and a multitude of canonical isomorphisms is presented. Moreover, the graded versions of the classical Lie algebras are introduced and some of their basic properties are described. (orig.)

  16. Geodynamic condition of formation of favorable structural positions for ore-grade gold placement in auminzatau-beltau ore area (the central kyzyl kum, western uzbekistan)

    Science.gov (United States)

    Janibekov, Bobir Omonovich; Turapov, M. K.

    2017-09-01

    Work is directed on studying of a geodynamic condition under which the structural positions controlling process of endogenous ore formation were formed. It is shown that explosive region tectonics under the influence of regional tectonic efforts formed structural elements (positions) which controlled formation of gold deposits. It is recognized that structural positions are defined by variety of systems of disjunctive dislocation and their relationship among themselves. Formation of favorable positions depends as well on morphology of ore controlling structures, on degree of their tectonic activity and spatial situation in relation to the direction of tectonic (geodynamic) efforts.

  17. Optimal design of a beam-based dynamic vibration absorber using fixed-points theory

    Science.gov (United States)

    Hua, Yingyu; Wong, Waion; Cheng, Li

    2018-05-01

    The addition of a dynamic vibration absorber (DVA) to a vibrating structure could provide an economic solution for vibration suppressions if the absorber is properly designed and located onto the structure. A common design of the DVA is a sprung mass because of its simple structure and low cost. However, the vibration suppression performance of this kind of DVA is limited by the ratio between the absorber mass and the mass of the primary structure. In this paper, a beam-based DVA (beam DVA) is proposed and optimized for minimizing the resonant vibration of a general structure. The vibration suppression performance of the proposed beam DVA depends on the mass ratio, the flexural rigidity and length of the beam. In comparison with the traditional sprung mass DVA, the proposed beam DVA shows more flexibility in vibration control design because it has more design parameters. With proper design, the beam DVA's vibration suppression capability can outperform that of the traditional DVA under the same mass constraint. The general approach is illustrated using a benchmark cantilever beam as an example. The receptance theory is introduced to model the compound system consisting of the host beam and the attached beam-based DVA. The model is validated through comparisons with the results from Abaqus as well as the Transfer Matrix method (TMM) method. Fixed-points theory is then employed to derive the analytical expressions for the optimum tuning ratio and damping ratio of the proposed beam absorber. A design guideline is then presented to choose the parameters of the beam absorber. Comparisons are finally presented between the beam absorber and the traditional DVA in terms of the vibration suppression effect. It is shown that the proposed beam absorber can outperform the traditional DVA by following this proposed guideline.

  18. Neutron absorbers and methods of forming at least a portion of a neutron absorber

    Energy Technology Data Exchange (ETDEWEB)

    Guillen, Donna P; Porter, Douglas L; Swank, W David; Erickson, Arnold W

    2014-12-02

    Methods of forming at least a portion of a neutron absorber include combining a first material and a second material to form a compound, reducing the compound into a plurality of particles, mixing the plurality of particles with a third material, and pressing the mixture of the plurality of particles and the third material. One or more components of neutron absorbers may be formed by such methods. Neutron absorbers may include a composite material including an intermetallic compound comprising hafnium aluminide and a matrix material comprising pure aluminum.

  19. Band Gap Grading of Stacked Cu(In,Ga)S{sub 2} Thin Films

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Seonghyun; Sohn, So Hyeong; Shim, Hyeong Seop; Park, Seung Min; Song, Jae Kyu [Kyung Hee University, Seoul (Korea, Republic of); Min, Byoung Koun [Korea Institute of Science and Technology, Seoul (Korea, Republic of)

    2016-01-15

    The band gap energy of CIGS, which depends on the composition variation and strain effect, can influence the collection and recombination of photocarriers. The solar cell efficiency is improved by the graded band gap in the absorber layer due to the enhanced carrier collection and the reduced carrier recombination. In our previous study, the photovoltaic performance of solar cells was affected by the stacking combination of layers, where the solar cell with dense-bottom and porous-top layers showed better performance than that with a reversely stacked structure. We studied the stacking effect of CIGS thin films. The stacking did not change E {sub g} of each layer, which led to the double grading of E {sub g} along the depth of the stacked films, mainly due to the difference in E {sub g} between the dense and porous layers. The higher degree of the grading in A+B+A improved J {sub sc}. However, the higher density of the defect states in A+B+A reduced V {sub oc}, which was inferred by the short lifetime of the carriers and the broad bandwidth of photoluminescence. Overall, the efficiency of A+B+A was only slightly improved compared to that of B+A.

  20. Radiative cooling of solar absorbers using a visibly transparent photonic crystal thermal blackbody

    Science.gov (United States)

    Zhu, Linxiao; Raman, Aaswath P.; Fan, Shanhui

    2015-01-01

    A solar absorber, under the sun, is heated up by sunlight. In many applications, including solar cells and outdoor structures, the absorption of sunlight is intrinsic for either operational or aesthetic considerations, but the resulting heating is undesirable. Because a solar absorber by necessity faces the sky, it also naturally has radiative access to the coldness of the universe. Therefore, in these applications it would be very attractive to directly use the sky as a heat sink while preserving solar absorption properties. Here we experimentally demonstrate a visibly transparent thermal blackbody, based on a silica photonic crystal. When placed on a silicon absorber under sunlight, such a blackbody preserves or even slightly enhances sunlight absorption, but reduces the temperature of the underlying silicon absorber by as much as 13 °C due to radiative cooling. Our work shows that the concept of radiative cooling can be used in combination with the utilization of sunlight, enabling new technological capabilities. PMID:26392542

  1. Chitin biological absorbable catheters bridging sural nerve grafts transplanted into sciatic nerve defects promote nerve regeneration.

    Science.gov (United States)

    Wang, Zhi-Yong; Wang, Jian-Wei; Qin, Li-Hua; Zhang, Wei-Guang; Zhang, Pei-Xun; Jiang, Bao-Guo

    2018-06-01

    To investigate the efficacy of chitin biological absorbable catheters in a rat model of autologous nerve transplantation. A segment of sciatic nerve was removed to produce a sciatic nerve defect, and the sural nerve was cut from the ipsilateral leg and used as a graft to bridge the defect, with or without use of a chitin biological absorbable catheter surrounding the graft. The number and morphology of regenerating myelinated fibers, nerve conduction velocity, nerve function index, triceps surae muscle morphology, and sensory function were evaluated at 9 and 12 months after surgery. All of the above parameters were improved in rats in which the nerve graft was bridged with chitin biological absorbable catheters compared with rats without catheters. The results of this study indicate that use of chitin biological absorbable catheters to surround sural nerve grafts bridging sciatic nerve defects promotes recovery of structural, motor, and sensory function and improves muscle fiber morphology. © 2018 John Wiley & Sons Ltd.

  2. Effect of ultraviolet light absorbers on photostabilization of azadirachtin-A in solution (part: II).

    Science.gov (United States)

    Deota, P T; Upadhyay, P R; Valodkar, V B

    2003-01-01

    The effect of photostabilization of azadirachtin-A (Aza-A) was examined in solutions when exposed to UV radiation, in the presence of four structurally different UV absorbers namely, p-aminobenzoic acid, 2,4-dihydroxybenzophenone, 4,4'-dihydroxybenzophenone and phenyl salicylate. The percentages of Aza-A recovered from the solutions after 6 h exposed to UV radiation in the presence and absence of UV absorbers indicated that the order of stabilization of Aza-A by these absorbers was similar to that obtained in the solid phase experiments in accordance with our previous observations. It is observed that the addition of phenyl salicylate in Aza-A (in 1:1 mole ratio) provides the excellent photostabilization of Aza-A molecule in solid phase as well as in solution among the four absorbers studied.

  3. OrbusNeich fully absorbable coronary stent platform incorporating dual partitioned coatings.

    Science.gov (United States)

    Cottone, Robert J; Thatcher, G Lawrence; Parker, Sherry P; Hanks, Laurence; Kujawa, David A; Rowland, Stephen M; Costa, Marco; Schwartz, Robert S; Onuma, Yoshinobu

    2009-12-15

    The field of stent based tissue engineering continues to revolutionise modern medicine by designing novel materials to restore vascular tissue function. Accordingly, the following discussion examines a novel, absorbable, polymeric scaffold engineered in combination with dual therapeutic coating, enabling locally administered temporary scaffolding in the coronary arteries for long term vascular patency and repair. This coronary stent platform consists of an absorbable polymeric material stent structure that incorporates a dual partitioned coating, by means of pro-healing EPC (endothelial progenitor cell) capture technology allowing for rapid endothelial coverage, and an absorbable polymer matrix with sustained elution of sirolimus, a drug controlling neointimal proliferation. This paper provides a brief overview of the various innovations developed by OrbusNeich to create this fully absorbable coronary device platform.

  4. Emitter and absorber assembly for multiple self-dual operation and directional transparency

    Science.gov (United States)

    Kalozoumis, P. A.; Morfonios, C. V.; Kodaxis, G.; Diakonos, F. K.; Schmelcher, P.

    2017-03-01

    We demonstrate how to systematically design wave scattering systems with simultaneous coherent perfect absorbing and lasing operation at multiple and prescribed frequencies. The approach is based on the recursive assembly of non-Hermitian emitter and absorber units into self-dual emitter-absorber trimers at different composition levels, exploiting the simple structure of the corresponding transfer matrices. In particular, lifting the restriction to parity-time-symmetric setups enables the realization of emitter and absorber action at distinct frequencies and provides flexibility with respect to the choice of realistic parameters. We further show how the same assembled scatterers can be rearranged to produce unidirectional and bidirectional transparency at the selected frequencies. With the design procedure being generically applicable to wave scattering in single-channel settings, we demonstrate it with concrete examples of photonic multilayer setups.

  5. Microstructure Analysis of Bismuth Absorbers for Transition-Edge Sensor X-ray Microcalorimeters

    Science.gov (United States)

    Yan, Daikang; Divan, Ralu; Gades, Lisa M.; Kenesei, Peter; Madden, Timothy J.; Miceli, Antonino; Park, Jun-Sang; Patel, Umeshkumar M.; Quaranta, Orlando; Sharma, Hemant; Bennett, Douglas A.; Doriese, William B.; Fowler, Joseph W.; Gard, Johnathon D.; Hays-Wehle, James P.; Morgan, Kelsey M.; Schmidt, Daniel R.; Swetz, Daniel S.; Ullom, Joel N.

    2018-03-01

    Given its large X-ray stopping power and low specific heat capacity, bismuth (Bi) is a promising absorber material for X-ray microcalorimeters and has been used with transition-edge sensors (TESs) in the past. However, distinct X-ray spectral features have been observed in TESs with Bi absorbers deposited with different techniques. Evaporated Bi absorbers are widely reported to have non-Gaussian low-energy tails, while electroplated ones do not show this feature. In this study, we fabricated Bi absorbers with these two methods and performed microstructure analysis using scanning electron microscopy and X-ray diffraction microscopy. The two types of material showed the same crystallographic structure, but the grain size of the electroplated Bi was about 40 times larger than that of the evaporated Bi. This distinction in grain size is likely to be the cause of their different spectral responses.

  6. Synthesis of hemicellulose-acrylic acid graft copolymer super water absorbent resin by ultrasonic irradiation technology

    Directory of Open Access Journals (Sweden)

    Fangfang LIU

    2015-12-01

    Full Text Available The hemicellulose super water absorbent resin is prepared by using ultrasonic irradiation technology, with the waste liquid produced during the preparation of viscose fiber which contains a large amount of hemicellulose as raw material, acrylic acid as graft monomer, N,N’-methylene bis acrylamide (NMBA as cross linking agent, and (NH42S2O8-NaHSO3 as the redox initiation system. The synthesis conditions, structure and water absorption ability of resin are discussed. The results indicate that water absorbency of the resin is 311 g/g, the tap water absorbency is 102 g/g, the normal saline absorbency is 55 g/g, and the artificial urine absorbency is 31 g/g under the optimal synthesis conditions, so the resin has great water absorption rate and water retaining capacity. The FT-IR and SEM analysis shows that the resin with honeycomb network structure is prepared. The successfully synthesized of the resin means that the hemicellulose waste liquid can be highly effectively recycled, and it provides a kind of new raw material for the synthesis of super water absorbent resin.

  7. Absorbing materials of thin film for photovoltaic structures prepared by the process of pyrolytic spraying; Materiales absorbedores en pelicula delgada para estructuras fotovoltaicas preparados por el proceso de rocio pirolitico

    Energy Technology Data Exchange (ETDEWEB)

    Calixto Rodriguez, Manuela

    2006-11-15

    In this thesis work thin semiconducting films were grown with the following compounds: In{sub 2}S{sub 3}, Ag{sub 2}S, AgInS{sub 2}, SnS{sub 2} and SnS with the pyrolytic spray technique. The structural, optical and electrical proposals of these films were analyzed to determine the set of deposit parameters in which are obtained the physical properties for the applications of the same in photovoltaic structures. It was found that the molar relation in solution of the departing compounds and the deposit temperature are the same dominant parameters in the process of growing the films. For the deposit of thin films of Indio acetate were used and N, N-dimetil tiourea as precursory compounds of In and S, respectively. Polycrystalline films were obtained from the compound In{sub 2}S{sub 3} using underlying temperatures, Ts, between 400 and 450 degrees Celsius, and Indio acetate solutions and N, N-dimetil tiourea with molar relations (In:S) of 1:8 and 1:1. The energy breach, Eg, of these films varies from 2.04 to 2.67 eV, and the value of the conductivity in the darkness, D varies from 10-7 to 1(cm)-1 in function of the molar relation in solution. It was found that the deposited films using a molar relation of In:S=1:8 are of intrinsic nature independently of Ts, while the ones deposited using a molar relations of In:S=1:1 and Ts 400 degrees Celsius posses type-n conductivity. Using the molar relation of I:S=1:1 and Ts=500 degrees Celsius the compound polycrystalline of In{sub 2}O{sub 3} is obtained whose optical and electrical properties are Eg {approx} 3 eV and D=11 (cm)-1, with electrical conductivity type-n. The deposited films using a molar relation of In:S=1:1 and Ts=450 degrees Celsius are the ones that keep the appropriate characteristics for their use as type-n material in photovoltaic structures (Eg=2eV and D=1?-1 com-1). [Spanish] En este trabajo de tesis se crecieron peliculas delgadas semiconductoras de los compuestos: In{sub 2}S{sub 3}, Ag{sub 2}S, Ag

  8. Absorbed dose thresholds and absorbed dose rate limitations for studies of electron radiation effects on polyetherimides

    Science.gov (United States)

    Long, Edward R., Jr.; Long, Sheila Ann T.; Gray, Stephanie L.; Collins, William D.

    1989-01-01

    The threshold values of total absorbed dose for causing changes in tensile properties of a polyetherimide film and the limitations of the absorbed dose rate for accelerated-exposure evaluation of the effects of electron radiation in geosynchronous orbit were studied. Total absorbed doses from 1 kGy to 100 MGy and absorbed dose rates from 0.01 MGy/hr to 100 MGy/hr were investigated, where 1 Gy equals 100 rads. Total doses less than 2.5 MGy did not significantly change the tensile properties of the film whereas doses higher than 2.5 MGy significantly reduced elongation-to-failure. There was no measurable effect of the dose rate on the tensile properties for accelerated electron exposures.

  9. Classroom: Efficient Grading

    Science.gov (United States)

    Shaw, David D.; Pease, Leonard F., III.

    2014-01-01

    Grading can be accelerated to make time for more effective instruction. This article presents specific time management strategies selected to decrease administrative time required of faculty and teaching assistants, including a multiple answer multiple choice interface for exams, a three-tier grading system for open ended problem solving, and a…

  10. Grain Grading and Handling.

    Science.gov (United States)

    Rendleman, Matt; Legacy, James

    This publication provides an introduction to grain grading and handling for adult students in vocational and technical education programs. Organized in five chapters, the booklet provides a brief overview of the jobs performed at a grain elevator and of the techniques used to grade grain. The first chapter introduces the grain industry and…

  11. Design and development of radiation absorber for sighting beam line

    International Nuclear Information System (INIS)

    Sridhar, R.; Shukla, S.K.

    2005-01-01

    During the commissioning of Indus-2 , it is necessary to view the synchrotron radiation that will be emanating from the dipole exit ports. The 10 0 beam line from dipole 11 was earmarked for sighting beam line. The synchrotron radiation power density would be around 340 watts on the photon absorber inside the radiation absorber module, at the specified beam power of Indus-2. The beam striking on this photon absorber produces x-rays and Bremsstrahlung radiation. These are to be stopped and absorbed by radiation absorber. The photon absorber and the radiation absorber are integrated in a single vacuum chamber and actuated by a pneumatic cylinder connected using a bellow. Radiation absorber was needed to isolate the diagnostic components and to protect them from radiation a well as heat when they were not in use. The paper describes the design, calculation and development of the dynamic photon cum radiation absorber. The ultimate vacuum performance is also described. (author)

  12. Vascular grading of angiogenesis

    DEFF Research Database (Denmark)

    Hansen, S; Grabau, D A; Sørensen, Flemming Brandt

    2000-01-01

    The study aimed to evaluate the prognostic value of angiogenesis by vascular grading of primary breast tumours, and to evaluate the prognostic impact of adding the vascular grade to the Nottingham Prognostic Index (NPI). The investigation included 836 patients. The median follow-up time was 11...... years and 4 months. The microvessels were immunohistochemically stained by antibodies against CD34. Angiogenesis was graded semiquantitatively by subjective scoring into three groups according to the expected number of microvessels in the most vascular tumour area. The vascular grading between observers...... for 24% of the patients, who had a shift in prognostic group, as compared to NPI, and implied a better prognostic dissemination. We concluded that the angiogenesis determined by vascular grading has independent prognostic value of clinical relevance for patients with breast cancer....

  13. Vascular grading of angiogenesis

    DEFF Research Database (Denmark)

    Hansen, S; Grabau, D A; Sørensen, Flemming Brandt

    2000-01-01

    The study aimed to evaluate the prognostic value of angiogenesis by vascular grading of primary breast tumours, and to evaluate the prognostic impact of adding the vascular grade to the Nottingham Prognostic Index (NPI). The investigation included 836 patients. The median follow-up time was 11...... years and 4 months. The microvessels were immunohistochemically stained by antibodies against CD34. Angiogenesis was graded semiquantitatively by subjective scoring into three groups according to the expected number of microvessels in the most vascular tumour area. The vascular grading between observers...... impact for 24% of the patients, who had a shift in prognostic group, as compared to NPI, and implied a better prognostic dissemination. We concluded that the angiogenesis determined by vascular grading has independent prognostic value of clinical relevance for patients with breast cancer....

  14. Fault Detection for Automotive Shock Absorber

    Science.gov (United States)

    Hernandez-Alcantara, Diana; Morales-Menendez, Ruben; Amezquita-Brooks, Luis

    2015-11-01

    Fault detection for automotive semi-active shock absorbers is a challenge due to the non-linear dynamics and the strong influence of the disturbances such as the road profile. First obstacle for this task, is the modeling of the fault, which has been shown to be of multiplicative nature. Many of the most widespread fault detection schemes consider additive faults. Two model-based fault algorithms for semiactive shock absorber are compared: an observer-based approach and a parameter identification approach. The performance of these schemes is validated and compared using a commercial vehicle model that was experimentally validated. Early results shows that a parameter identification approach is more accurate, whereas an observer-based approach is less sensible to parametric uncertainty.

  15. Carbon Nanomaterials for Optical Absorber Applications

    Directory of Open Access Journals (Sweden)

    Anupama KAUL

    2011-12-01

    Full Text Available Optical absorbers based on vertically aligned multi-walled carbon nanotubes (MWCNTs, synthesized using electric-field assisted growth, are described here that show an ultra-low reflectance, 100X lower compared to the benchmark, a diffuse metal black - Au-black - from wavelength l ~ 350 nm – 2500 nm. The reflectance of the MWCNT arrays was measured to be as low as 0.02 % at 2 mm in the infra-red (IR. Growth conditions were optimized for the realization of high-areal density arrays of MWCNTs using a plasma-based chemical vapor deposition (CVD process. Such high efficiency absorbers are particularly attractive for radiometry, as well as energy harnessing applications. Optical modeling calculations were conducted that enabled a determination of the extinction coefficient in the films.

  16. Use of Wedge Absorbers in MICE

    Energy Technology Data Exchange (ETDEWEB)

    Neuffer, D. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Summers, D. [Univ. of Mississippi, Oxford, MS (United States); Mohayai, T. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); IIT, Chicago, IL (United States); Snopok, P. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); IIT, Chicago, IL (United States); Rogers, C. [Science and Technology Facilities Council (STFC), Oxford (United Kingdom). Rutherford Appleton Lab. (RAL)

    2017-03-01

    Wedge absorbers are needed to obtain longitudinal cooling in ionization cooling. They also can be used to obtain emittance exchanges between longitudinal and transverse phase space. There can be large exchanges in emittance, even with single wedges. In the present note we explore the use of wedge absorbers in the MICE experiment to obtain transverse–longitudinal emittance exchanges within present and future operational conditions. The same wedge can be used to explore “direct” and “reverse” emittance exchange dynamics, where direct indicates a configuration that reduces momentum spread and reverse is a configuration that increases momentum spread. Analytical estimated and ICOOL and G4BeamLine simulations of the exchanges at MICE parameters are presented. Large exchanges can be obtained in both reverse and direct configurations.

  17. Development of an innovative solar absorber

    Science.gov (United States)

    Goodchild, Gavin

    Solar thermal systems have great potential to replace or reduce the dependence of conventional fossil fuel based heating technologies required for space and water heating. Specifically solar domestic hot water systems can contribute 50-75% of the annual thermal load. To date residential users have been slow to purchase and install systems, primarily due to the large monetary investment required to purchase and install a system. Recent innovations in materials design and manufacturing techniques, offer opportunities for the development of absorber plate designs that have the potential to reduce cost, increase efficiency and reduce payback periods. Consequently, this design study was conducted in conjunction with industrial partners to develop an improved absorber based on roll bond manufacturing that can be produced at reduced cost with comparable or greater thermal efficiency.

  18. Effect of the bio-absorbent on the microwave absorption property of the flaky CIPs/rubber absorbers

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Yang; Xu, Yonggang, E-mail: xuyonggang221@163.com; Cai, Jun; Yuan, Liming; Zhang, Deyuan

    2015-09-01

    Microwave absorbing composites filled with flaky carbonyl iron particles (CIPs) and the bio-absorbent were prepared by using a two-roll mixer and a vulcanizing machine. The electromagnetic (EM) parameters were measured by a vector network analyzer and the reflection loss (RL) was measured by the arch method in the frequency range of 1–4 GHz. The uniform dispersion of the absorbents was verified by comparing the calculated RL with the measured one. The results confirm that as the bio-absorbent was added, the permittivity was increased due to the volume content of absorbents, and the permeability was enlarged owing to the volume content of CIPs and interactions between the two absorbents. The composite filled with bio-absorbents achieved an excellent absorption property at a thickness of 1 mm (minimum RL reaches −7.8 dB), and as the RL was less than −10 dB the absorption band was widest (2.1–3.8 GHz) at a thickness of 2 mm. Therefore, the bio-absorbent is a promising additive candidate on fabricating microwave absorbing composites with a thinner thickness and wider absorption band. - Graphical abstract: Morphology of composites filled with flaky CIPs and the bio-absorbent. The enhancement of bio-absorbent on the electromagnetic absorption property of composites filled with flaky carbonyl iron particles (CIPs) is attributed to the interaction of the two absorbents. The volume content of the FCMPs with the larger shape CIPs play an important role in this effects, the composites filled with irons and bio-absorbents can achieve wider-band and thinner-thickness absorbing materials. - Highlights: • Absorbers filled with bio-absorbents and CIPs was fabricated. • Bio-absorbents enhanced the permittivity and permeability of the composites. • The absorbent interactions play a key role in the enhancement mechanism. • Bio-absorbents enhanced the composite RL in 1–4 GHz.

  19. Mechanical Characteristics of Submerged Arc Weldment in API Gas Pipeline Steel of Grade X65

    International Nuclear Information System (INIS)

    Hashemi, S. H.; Mohammadyani, D.

    2011-01-01

    The mechanical properties of submerged arc weldment (SAW) in gas transportation pipeline steel of grade API X65 (65 ksi yield strength) were investigated. This steel is produced by thermo mechanical control rolled (TMC), and is largely used in Iran gas piping systems and networks. The results from laboratory study on three different regions; i.e. base metal (BM), fusion zone (FZ) and heat affected zone (HAZ) were used to compare weldment mechanical characteristics with those specified by API 5L (revision 2004) standard code. Different laboratory experiments were conducted on test specimens taken from 48 inch outside diameter and 14.3 mm wall thickness gas pipeline. The test results showed a gradient of microstructure and Vickers hardness data from the centerline of FZ towards the unaffected MB. Similarly, lower Charpy absorbed energy (compared to BM) was observed in the FZ impact specimens. Despite this, the API specifications were fulfilled in three tested zones, ensuring pipeline structural integrity under working conditions.

  20. Removing fuelling transient using neutron absorbers

    Energy Technology Data Exchange (ETDEWEB)

    Paquette, S.; Chan, P.K.; Bonin, H.W., E-mail: Stephane.Paquette@rmc.ca [Royal Military College of Canada, Chemistry and Chemical Engineering Dept., Kingston, Ontario (Canada); Pant, A. [Cameco Fuel Manufacturing, Port Hope, Ontario (Canada)

    2012-07-01

    Preliminary criticality and burnup calculation results indicate that by employing a small amount of neutron absorber the fuelling transient, currently occurring in a CANDU 37-element fuel bundle, can be significantly reduced. A parametric study using the Los Alamos National Laboratories' MCNP 5 code and Atomic Energy of Canada Limited's WIMS-AECL 3.1 is presented in this paper. (author)

  1. Radiation and shielding around beam absorbers

    International Nuclear Information System (INIS)

    Hurkmans, A.; Maas, R.

    1978-12-01

    During operational conditions it is anticipated that a fair amount of the total available beam power is dumped in either the slit system on one of the beam dumps. Thses beam absorbers therefore become strong radioactive sources. The radiation level due to the absorption of a 100 kW electron beam is estimated and the problem of residual activity is treated. Proposed shielding materials are discussed. (C.F.)

  2. Visual indicator of absorbed radiation doses

    Energy Technology Data Exchange (ETDEWEB)

    Generalova, V V; Krasovitskii, B M; Vainshtok, B A; Gurskii, M N

    1968-10-15

    A visual indicator of the absorbed doses of ionizing radiation is proposed. The indicator has a polymer base with the addition of a dye. A distinctive feature of the indicator consists of the use of polystyrene as its polymer base with the addition of halogen-containing hydrocarbon and the light-proof dye. Such combination of the radiation-resistant polymer of polystyrene and the light-proof dyestuff makes the proposed indicator highly stable.

  3. Heaving buoys, point absorbers and arrays.

    Science.gov (United States)

    Falnes, Johannes; Hals, Jørgen

    2012-01-28

    Absorption of wave energy may be considered as a phenomenon of interference between incident and radiated waves generated by an oscillating object; a wave-energy converter (WEC) that displaces water. If a WEC is very small in comparison with one wavelength, it is classified as a point absorber (PA); otherwise, as a 'quasi-point absorber'. The latter may be a dipole-mode radiator, for instance an immersed body oscillating in the surge mode or pitch mode, while a PA is so small that it should preferably be a source-mode radiator, for instance a heaving semi-submerged buoy. The power take-off capacity, the WEC's maximum swept volume and preferably also its full physical volume should be reasonably matched to the wave climate. To discuss this matter, two different upper bounds for absorbed power are applied in a 'Budal diagram'. It appears that, for a single WEC unit, a power capacity of only about 0.3 MW matches well to a typical offshore wave climate, and the full physical volume has, unfortunately, to be significantly larger than the swept volume, unless phase control is used. An example of a phase-controlled PA is presented. For a sizeable wave-power plant, an array consisting of hundreds, or even thousands, of mass-produced WEC units is required.

  4. An absorbed dose calorimeter for IMRT dosimetry

    International Nuclear Information System (INIS)

    Duane, S.; Aldehaybes, M.; Bailey, M.; Lee, N.D.; Thomas, C.G.; Palmans, H.

    2012-01-01

    A new calorimeter for dosimetry in small and complex fields has been built. The device is intended for the direct determination of absorbed dose to water in moderately small fields and in composite fields such as IMRT treatments, and as a transfer instrument calibrated against existing absorbed dose standards in conventional reference conditions. The geometry, materials and mode of operation have been chosen to minimize detector perturbations when used in a water phantom, to give a reasonably isotropic response and to minimize the effects of heat transfer when the calorimeter is used in non-reference conditions in a water phantom. The size of the core is meant to meet the needs of measurement in IMRT treatments and is comparable to the size of the air cavity in a type NE2611 ionization chamber. The calorimeter may also be used for small field dosimetry. Initial measurements in reference conditions and in an IMRT head and neck plan, collapsed to gantry angle zero, have been made to estimate the thermal characteristics of the device, and to assess its performance in use. The standard deviation (estimated repeatability) of the reference absorbed dose measurements was 0.02 Gy (0.6%). (authors)

  5. Neutron absorbers, and the production method

    International Nuclear Information System (INIS)

    Kayano, Hideo; Yajima, Seishi; Oono, Hironori.

    1979-01-01

    Purpose: To integrally sinter a metal powder and a metal network material thereby to obtain a material having a high neutron absorbing function, an excellent corrosion resistance and an excellent oxidation resistance. Method: An element having a high neutron absorbing function, such as Gd, or a compound thereof and a powder of a metal having excellent corrosion resistance, oxidation resistance and ductility, such as Fe, Cr or the like are uniformly mixed with each other. In a case where a substance having a neutron absorbing function is a hydroxide an organic complex or the like, it is formed into a gel-like substance and mixed uniformly with the metal powder, the gel-like substance being pasted, and covered on the surface of the metal powder and dried. Then, the mixture or the dry coated material is extended and the metal network material having excellent corrosion resistance, oxidation resistance and ductility is covered or interposed or between at least one layer of upper, intermediate or lower layers of said laminated material, and thereafter is subjected to cold or hot rolling, and then sintered and furthermore rolled, if necessary, the thus treated material being burned in vacuum or a non-oxidizing atmosphere. (Kamimura, M.)

  6. Optimizing analysis of W-AlN cermet solar absorbing coatings

    International Nuclear Information System (INIS)

    Zhang Qichu

    2001-01-01

    The layer thickness and tungsten metal volume fraction of W-AlN cermet solar selective absorbing coatings on a W, Cu or Al infrared reflector with a surface aluminium oxynitride (AlON) or Al 2 O 3 ceramic anti-reflector layer were optimized using physical modelling calculations. Due to limited published data for the refractive index of AlN, and likely oxygen contamination during reactive sputtering of AlN ceramic materials, AlON was used as the ceramic component and the published value of its refractive index was employed. The dielectric function and then the complex refractive index of W-AlON cermet materials were calculated using the Ping Sheng approximation. The downhill simplex method in multi-dimensions was used in the numerical calculation to achieve maximum photo-thermal conversion efficiency at 350 0 C under a concentration factor of 30 for a solar collector tube. Optimization calculation results show that the initial graded (ten-step layers) cermet films all converge to something close to a three-layer film structure, which consists of a low metal volume fraction cermet layer on a high metal volume fraction cermet layer on a metallic infrared reflector with a surface ceramic anti-reflection layer. The optimized three-layer solar coatings have a high solar absorptance of 0.95 for AlON and 0.96 for the Al 2 O 3 anti-reflection layer, and a low hemispherical emittance of 0.073 at 350 deg. C. For the optimized three-layer films the solar radiation is efficiently absorbed internally and by phase interference. Thermal loss is very low for optimized three-layer films due to high reflectance values in the thermal infrared wavelength range and a very sharp edge between low solar reflectance and high thermal infrared reflectance. The high metal volume fraction cermet layer has a metal-like optical behaviour in the thermal infrared wavelength range and makes the largest contribution to the increase of emittance compared with that of the metal infrared reflector

  7. Optimizing analysis of W-AlN cermet solar absorbing coatings

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Qichu [School of Physics, University of Sydney, NSW (Australia)

    2001-11-07

    The layer thickness and tungsten metal volume fraction of W-AlN cermet solar selective absorbing coatings on a W, Cu or Al infrared reflector with a surface aluminium oxynitride (AlON) or Al{sub 2}O{sub 3} ceramic anti-reflector layer were optimized using physical modelling calculations. Due to limited published data for the refractive index of AlN, and likely oxygen contamination during reactive sputtering of AlN ceramic materials, AlON was used as the ceramic component and the published value of its refractive index was employed. The dielectric function and then the complex refractive index of W-AlON cermet materials were calculated using the Ping Sheng approximation. The downhill simplex method in multi-dimensions was used in the numerical calculation to achieve maximum photo-thermal conversion efficiency at 350{sup 0}C under a concentration factor of 30 for a solar collector tube. Optimization calculation results show that the initial graded (ten-step layers) cermet films all converge to something close to a three-layer film structure, which consists of a low metal volume fraction cermet layer on a high metal volume fraction cermet layer on a metallic infrared reflector with a surface ceramic anti-reflection layer. The optimized three-layer solar coatings have a high solar absorptance of 0.95 for AlON and 0.96 for the Al{sub 2}O{sub 3} anti-reflection layer, and a low hemispherical emittance of 0.073 at 350 deg. C. For the optimized three-layer films the solar radiation is efficiently absorbed internally and by phase interference. Thermal loss is very low for optimized three-layer films due to high reflectance values in the thermal infrared wavelength range and a very sharp edge between low solar reflectance and high thermal infrared reflectance. The high metal volume fraction cermet layer has a metal-like optical behaviour in the thermal infrared wavelength range and makes the largest contribution to the increase of emittance compared with that of the metal

  8. Optimizing analysis of W-AlN cermet solar absorbing coatings

    Energy Technology Data Exchange (ETDEWEB)

    Qi-Chu Zhang [University of Sydney, NSW (Australia). School of Physics

    2001-11-07

    The layer thickness and tungsten metal volume fraction of W-AlN cermet solar selective absorbing coatings on a W, Cu or Al infrared reflector with a surface aluminium oxynitride (AlON) or Al{sub 2}O{sub 3} ceramic anti-reflector layer were optimized using physical modelling calculations. Due to limited published data for the refractive index of AlN, and likely oxygen contamination during reactive sputtering of AlN ceramic materials, AlON was used as the ceramic component and the published value of its refractive index was employed. The dielectric function and then the complex refractive index of W-AlON cermet materials were calculated using the Ping Sheng approximation. The downhill simplex method in multi-dimensions was used in the numerical calculation to achieve maximum photo-thermal conversion efficiency at 350{sup o}C under a concentration factor of 30 for a solar collector tube. Optimization calculation results show that the initial graded (ten-step layers) cermet films all converge to something close to a three-layer film structure, which consists of a low metal volume fraction cermet layer on a high metal volume fraction cermet layer on a metallic infrared reflector with a surface ceramic anti-reflection layer. The optimized three-layer solar coatings have a high solar absorptance of 0.95 for AlON and 0.96 for the Al{sub 2}O{sub 3} anti-reflection layer, and a low hemispherical emittance of 0.073 at 350{sup o}C. For the optimized three-layer films the solar radiation is efficiently absorbed internally and by phase interference. Thermal loss is very low for optimized three-layer films due to high reflectance values in the thermal infrared wavelength range and a very sharp edge between low solar reflectance and high thermal infrared reflectance. The high metal volume fraction cermet layer has a metal-like optical behaviour in the thermal infrared wavelength range and makes the largest contribution to the increase of emittance compared with that of the metal

  9. The effects of social structure and social capital on changes in smoking status from 8th to 9th grade: results of the Child and Adolescent Behaviors in Long-term Evolution (CABLE) study.

    Science.gov (United States)

    Chen, Chun-Yuan; Wu, Chi-Chen; Chang, Hsing-Yi; Yen, Lee-Lan

    2014-05-01

    Social structure and social capital are important variables for public health strategies seeking to prevent smoking among adolescents. The purpose of this study was to examine the relationships between social structure, social capital and changes in smoking status from the 8th to 9th grade in Taiwan. Data were obtained from the Child and Adolescent Behaviors in Long-term Evolution (CABLE) project. The study analyzed a final sample of 1937 students (50.7% female). Each layer of social structure was associated with a particular form of social capital. Students whose parents were married and living together had higher family social capital. After controlling for background variables, the social structure variable of friends who smoke was significantly associated with changes in smoking status. Students reporting more school attachment were less likely to start smoking. Students with higher parental supervision was associated with less chance of being a consistent smoker, whereas participation of social organization outside of school was associated with continued smoking. Attending school club was associated with higher probability of smoking cessation. Smoking prevention and intervention strategies aimed at junior high school students should be tailored to the particular form of social capital important for each type of smoking status. Copyright © 2013 Elsevier Inc. All rights reserved.

  10. Development of a toroidal shell-type shock absorber for an irradiated fuel shipping cask

    International Nuclear Information System (INIS)

    Sugita, Y.; Mochizuki, S.

    1983-01-01

    This study described the design method of a toroidal shell-type shock absorber and the dynamic responses of the cask body, the internal structure and water when this shock absorber was used. Conclusions are: the calculated results on the basis of the master curves of non-dimensionalized force-deflection relations by static compression tests show a close agreement with the experimental results; the internal structure moves together with the cask body in every position; and the maximum water pressure is larger by a factor of 1.2 than the static pressure multiplied by the maximum deceleration in every direction due to the low-frequency wave propagation

  11. Design considerations for application of metallic honeycomb as an energy absorber

    International Nuclear Information System (INIS)

    Lee, W.H.; Roemer, R.E.

    1980-01-01

    Design for postulated accidents in nuclear power plants often requires mitigation of impact to safety-related structures. Plastically designed, energy absorbing mechanisms are often used in the design of such mitigating structures. Metallic honeycomb is the most efficient, practical, energy-absorbing material currently in use. Recent tests indicate that its use in this application, however, presents some unique design and fabrication problems. The paper presents the results of static and dynamic crush tests concerned with the effect of impact velocity, material properties, cell density, loading configuration, and overall pad geometry. Specific design recommendations are made in each area, and suggestions are provided to improve fabrication techniques and minimize subsequent problems

  12. Two-dimensional simulation of broad-band ferrite electromagnetic wave absorbers by using the FDTD method

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Hyun Jin; Kim, Dong Il [Korea Maritime University, Busan (Korea, Republic of)

    2004-10-15

    The purpose of this simulation study is to design and fabricate an electromagnetic (EM) wave absorber in order to develop a wide-band absorber. We have proposed and modeled a bird-eye-type and cutting-cone-type EM wave absorber by using the equivalent material constants method (EMCM), and we simulated them by using a finite-difference time-domain (FDTD) method. A two or a three-dimensional simulation would be desirable to analyze the EM wave absorber characteristics and to develop new structures. The two-dimensional FDTD simulation requires less computer resources than a three-dimensional simulation to consider the structural effects of the EM wave absorbers. The numerical simulation by using the FDTD method shows propagating EM waves in various types of periodic structure EM wave absorbers. Simultaneously, a Fourier analysis is used to characterize the input pulse and the reflected EM waves for ferrite absorbers with various structures. The results have a wide-band reflection-reducing characteristic. The validity of the proposed model was confirmed by comparing the two-dimensional simulation with the experimental results. The simulations were carried out in the frequency band from 30 MHz to 10 GHz.

  13. Two-dimensional simulation of broad-band ferrite electromagnetic wave absorbers by using the FDTD method

    International Nuclear Information System (INIS)

    Yoon, Hyun Jin; Kim, Dong Il

    2004-01-01

    The purpose of this simulation study is to design and fabricate an electromagnetic (EM) wave absorber in order to develop a wide-band absorber. We have proposed and modeled a bird-eye-type and cutting-cone-type EM wave absorber by using the equivalent material constants method (EMCM), and we simulated them by using a finite-difference time-domain (FDTD) method. A two or a three-dimensional simulation would be desirable to analyze the EM wave absorber characteristics and to develop new structures. The two-dimensional FDTD simulation requires less computer resources than a three-dimensional simulation to consider the structural effects of the EM wave absorbers. The numerical simulation by using the FDTD method shows propagating EM waves in various types of periodic structure EM wave absorbers. Simultaneously, a Fourier analysis is used to characterize the input pulse and the reflected EM waves for ferrite absorbers with various structures. The results have a wide-band reflection-reducing characteristic. The validity of the proposed model was confirmed by comparing the two-dimensional simulation with the experimental results. The simulations were carried out in the frequency band from 30 MHz to 10 GHz.

  14. Broadband transmission noise reduction of smart panels featuring piezoelectric shunt circuits and sound-absorbing material.

    Science.gov (United States)

    Kim, Jaehwan; Lee, Joong-Kuen

    2002-09-01

    The possibility of a broadband noise reduction of piezoelectric smart panels is experimentally studied. A piezoelectric smart panel is basically a plate structure on which piezoelectric patches with electrical shunt circuits are mounted and sound-absorbing material is bonded on the surface of the structure. Sound-absorbing material can absorb the sound transmitted at the midfrequency region effectively while the use of piezoelectric shunt damping can reduce the transmission at resonance frequencies of the panel structure. To be able to reduce the sound transmission at low panel resonance frequencies, piezoelectric damping using the measured electrical impedance model is adopted. A resonant shunt circuit for piezoelectric shunt damping is composed of resistor and inductor in series, and they are determined by maximizing the dissipated energy through the circuit. The transmitted noise-reduction performance of smart panels is tested in an acoustic tunnel. The tunnel is a square cross-sectional tube and a loudspeaker is mounted at one side of the tube as a sound source. Panels are mounted in the middle of the tunnel and the transmitted sound pressure across panels is measured. When an absorbing material is bonded on a single plate, a remarkable transmitted noise reduction in the midfrequency region is observed except for the fundamental resonance frequency of the plate. By enabling the piezoelectric shunt damping, noise reduction is achieved at the resonance frequency as well. Piezoelectric smart panels incorporating passive absorbing material and piezoelectric shunt damping is a promising technology for noise reduction over a broadband of frequencies.

  15. The strong non-reciprocity of metamaterial absorber: characteristic, interpretation and modelling

    Energy Technology Data Exchange (ETDEWEB)

    Li Yuanxun; Xie Yunsong; Zhang Huaiwu; Liu Yingli; Wen Qiye; Ling Weiwei, E-mail: liyuanxun@uestc.edu.c [State Key Laboratory of Electronic Thin Film and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, 610054 (China)

    2009-05-07

    We simulated the metamaterial absorbers in two propagation conditions and observed the universal phenomenon of strong non-reciprocity. It is found that this non-reciprocity cannot be well interpreted using the effective medium theory, which indicates that the designing and understanding for the metamaterial absorber based on the proposed effective medium theory could not be applicable. The reason is pointed out that the metamaterial absorber does not satisfy the homogeneous-effective limit. So we put forward a three-parameter modified effective medium theory to fully describe the metamaterial absorbers. We have also investigated the relationships of S-parameters and absorptance among the metamaterial absorbers and the two components inside. Then the power absorption distributions in these three structures are discussed in detail. It can be concluded that the absorption is derived from the ERR structure and is enhanced largely by the coupling mechanism, and the strong non-reciprocity results from the different roles which wire structure plays in both propagation conditions.

  16. The strong non-reciprocity of metamaterial absorber: characteristic, interpretation and modelling

    International Nuclear Information System (INIS)

    Li Yuanxun; Xie Yunsong; Zhang Huaiwu; Liu Yingli; Wen Qiye; Ling Weiwei

    2009-01-01

    We simulated the metamaterial absorbers in two propagation conditions and observed the universal phenomenon of strong non-reciprocity. It is found that this non-reciprocity cannot be well interpreted using the effective medium theory, which indicates that the designing and understanding for the metamaterial absorber based on the proposed effective medium theory could not be applicable. The reason is pointed out that the metamaterial absorber does not satisfy the homogeneous-effective limit. So we put forward a three-parameter modified effective medium theory to fully describe the metamaterial absorbers. We have also investigated the relationships of S-parameters and absorptance among the metamaterial absorbers and the two components inside. Then the power absorption distributions in these three structures are discussed in detail. It can be concluded that the absorption is derived from the ERR structure and is enhanced largely by the coupling mechanism, and the strong non-reciprocity results from the different roles which wire structure plays in both propagation conditions.

  17. Preparation and characterization of functional poly(vinylidene fluoride) (PVDF) membranes with ultraviolet-absorbing property

    Science.gov (United States)

    Dong, Li; Liu, Xiangdong; Xiong, Zhengrong; Sheng, Dekun; Lin, Changhong; Zhou, Yan; Yang, Yuming

    2018-06-01

    We first reported a strategy to prepare functional poly(vinylidene fluoride) (PVDF) membranes with excellent ultraviolet-absorbing property through chemically induced grafting. Herein, the polymerizable ultraviolet (UV) absorber 2-hydroxy-4-(3-methacryloxy-2-hydroxylpropoxy) benzophenone (BPMA) made by ourselves was grafted onto the PVDF chains that have been pretreated with tetraethylammonium hydroxide (TEAH) alkaline solution. Moreover, the effect of experiment conditions such as the alkali and monomer concentrations, alkali treatment time on the UV-absorbing property of the obtained PVDF-g-PBPMA membranes were studied in detail. The chemical structure of the modified membranes was confirmed by 1H NMR, FT-IR and XPS measurements. Meanwhile, the thermal and UV-absorbing properties were characterized by TGA, DSC and UV-Vis spectrophotometer, respectively. The results indicated that BPMA side chains were successfully introduced onto PVDF backbones. Most importantly, the obtained PVDF-g-PBPMA membranes exhibited excellent UV-absorbing property. The transmittance of UV light at 300 nm decreased to as low as 0.02% and the UV light below 388 nm could be completely absorbed by the PVDF-g-PBPMA membrane made under optimal condition.

  18. Origami-inspired metamaterial absorbers for improving the larger-incident angle absorption

    International Nuclear Information System (INIS)

    Shen, Yang; Pang, Yongqiang; Wang, Jiafu; Ma, Hua; Pei, Zhibin; Qu, Shaobo

    2015-01-01

    When a folded resistive patch array stands up on a metallic plane, it can exhibit more outstanding absorption performance. Our theoretical investigations and simulations demonstrated that the folded resistive patch arrays can enhance the absorption bandwidth progressively with the increase of the incident angle for the oblique transverse magnetic incidence, which is contrary to the conventional resistive frequency selective surface absorber. On illumination, we achieved a 3D structure metamaterial absorber with the folded resistive patches. The proposed absorber is obtained from the inspiration of the origami, and it has broadband and lager-incident angle absorption. Both the simulations and the measurements indicate that the proposed absorber achieves the larger-incident angle absorption until 75° in the frequency band of 3.6–11.4 GHz. In addition, the absorber is extremely lightweight. The areal density of the fabricated sample is about 0.023 g cm −2 . Due to the broadband and lager-incident angle absorption, it is expected that the absorbers may find potential applications such as stealth technologies and electromagnetic interference. (paper)

  19. Structural and electrical properties of high-quality 0.41 μm-thick InSb films grown on GaAs (1 0 0) substrate with InxAl1−xSb continuously graded buffer

    International Nuclear Information System (INIS)

    Shin, Sang Hoon; Song, Jin Dong; Lim, Ju Young; Koo, Hyun Cheol; Kim, Tae Geun

    2012-01-01

    High-quality InSb was grown on a GaAs (1 0 0) substrate with an InAlSb continuously graded buffer (CGB). The temperatures of In, Al K-cells and substrate were modified during the growth of InAlSb CGB. The cross-section TEM image reveals that the defects due to lattice-mismatch disappear near lateral structures in CGB. The measured electron mobility of 0.41 μm-thick InSb was 46,300 cm 2 /Vs at 300 K. These data surpass the electron mobility of state-of-the-art InSb grown by other methods with similar thickness of InSb.

  20. Design and testing of a shock absorber for a type 1 container

    International Nuclear Information System (INIS)

    Sappok, M.; Beine, B.; Rittscher, D.

    1993-01-01

    A shock-absorber will be required for a rad. waste 'Konrad' type 1 container made of ductile cast iron whenever it will be used as a type B container according to the IAEA-Regulations for the Safe Transport of Radioactive materials. The shock-absorber has to protect the type B container during shipping such as to withstand the accident scenarios that are covered by the IAEA-Regulation tests without substantial loss of its shielding and tightness functions. The designation as type 1 container originates from German regulations for the intermediate storage site Gorleben and the final depository Konrad-mine. These regulations call for the limits on outside dimensions of 1700 mm in length, 1600 mm in width and 1450 mm in height as well as for a limit of 20 Mg on total weight without shock-absorber. The relatively simple design method for the shock-absorber has been validated by the test results. It can be extended to other materials and designs for shock-absorbers if reliable force-displacement-diagrams are available for the structural elements from which the absorbed energy and the displacements can be calculated by integration. In order to account for the dynamic effects, the better approximation of the true duration of the impact would be helpful. The present limit of 0.5 R p0,2 on the nominal stresses should be discussed because the large number of tests on containers made of ductile cast iron that have been performed up to now have shown a substantial level of conservatism on this respect. The sharply tapered pipes on edge Kl of the shock-absorbers should be replaced by pipe bends. This will result in smaller accelerations and in an even higher level of protection of the container than effected by the tested shock-absorber

  1. Radar absorbing properties of carbon nanotubes/polymer ...

    Indian Academy of Sciences (India)

    This research is devoted to the study of radar absorbing properties of the composites, based on the epoxy binder and ... Radar absorbing materials; carbon nanotubes; nanocomposites; reflection loss. 1. ..... So, for example, the papers of [3–5 ...

  2. Simulated mixed absorbers and effective atomic numbers for γ ...

    Indian Academy of Sciences (India)

    Keywords. γ-rays; γ attenuation; simulated mixed absorbers; effective atomic ... We have tried to simulate composite (mixed) absorbers ... Experimental method .... puter, Program manual, Centre for Radiation Research, National Bureau of ...

  3. Determination of chlorine in nuclear-grade uranium compounds

    International Nuclear Information System (INIS)

    Yang Chunqing; Liu Fuyun; Huang Dianfan

    1988-01-01

    The determination of chlorine in nuclear-grade uranium compounds is discribed. Chlorine is separated from uranium oxide pyrohydrolytically with stream of wet oxygen in a furnace at 800 ∼ 900 deg C. Chlorine is volatilized as hydrochloric acid, absorbed in a dilute alkaline solution and measured with chlorine-selective electrode. This method covers the concentration range of 10 ∼ 500 pm chlorine in uranium oxide. Precision of at least ± 10% and recovery of 85 ∼ 108% have been reported

  4. Development of hybrid composite radar wave absorbing structure for ...

    Indian Academy of Sciences (India)

    vehicles led to the invention of stealth technology. Rao and. Mahulikar [1] argue that 'Stealth technology ... vehicle increases the weight and also needs to be periodically repaired'. Chin and Lee [7] argue that the 'RAS .... EM wave electric field intensity) to Ei (incident EM wave electric field intensity) expressed by as follows':.

  5. Structure and properties of visible-light absorbing homodisperse nanoparticle

    Energy Technology Data Exchange (ETDEWEB)

    Benedict, Jason

    2018-04-05

    Broadly, the scientific progress from this award focused in two main areas: developing time-resolved X-ray diffraction methods and the synthesis and characterization of molecular systems relevant to solar energy harvesting. The knowledge of photo‐induced non‐equilibrium states is central to our understanding of processes involved in solar‐energy capture. More specifically, knowledge of the geometry changes on excitation and their relation to lifetimes and variation with adsorption of chromophores on the substrates is of importance for the design of molecular devices used in light capture.

  6. Development of hybrid composite radar wave absorbing structure for ...

    Indian Academy of Sciences (India)

    epoxy composite and balsa wood instead of PVC foam as the two have low dielectric properties and the latter has greater mechanical strength. 2. Specification of the materials used. The plain weave E-glass fibre and epoxy resin is purchased.

  7. Effect of inclusions' distribution on microwave absorbing properties of composites

    International Nuclear Information System (INIS)

    Qin, Siliang; Wang, Qingguo; Qu, Zhaoming

    2013-01-01

    Effect of inclusions' spatial distributions on the permeability and permittivity of composites is studied using the generalized Maxwell-Garnett equations. The result indicates that inclusions' orientation distribution can increase the longitudinal electromagnetic parameters. For inclusions' random and orientation distribution, single and three-layer absorbers are designed and optimized using genetic algorithm. The result shows that under a given absorbing requirement, absorber with inclusions' orientation distribution is lighter and thinner than absorber with inclusions' random distribution.

  8. Dynamic testing of airplane shock-absorbing struts

    Science.gov (United States)

    Langer, P; Thome, W

    1932-01-01

    Measurement of perpendicular impacts of a landing gear with different shock-absorbing struts against the drum testing stand. Tests were made with pneumatic shock absorbers having various degrees of damping, liquid shock absorbers, steel-spring shock absorbers and rigid struts. Falling tests and rolling tests. Maximum impact and gradual reduction of the impacts in number and time in the falling tests. Maximum impact and number of weaker impacts in rolling tests.

  9. On (m, n)-absorbing ideals of commutative rings

    Indian Academy of Sciences (India)

    with respect to various ring theoretic constructions and study (m, n)-absorbing ideals in several commutative rings. For example, in a Bézout ring or a Boolean ring, an ideal is an (m, n)-absorbing ideal if and only if it is an n-absorbing ideal, and in an almost. Dedekind domain every (m, n)-absorbing ideal is a product of at ...

  10. Absorbent material for type a radioactive materials packaging containing liquids

    International Nuclear Information System (INIS)

    Saunders, G.A.

    1989-11-01

    The application of absorbent materials to the packaging and transport of liquid radioactive materials in Type A packages has not been reported in the literature. However, a significant body of research exists on absorbent materials for personal hygiene products such as diapers. Absorption capacity is dependent on both the absorbent material and the liquid being absorbed. Theoretical principles for capillary absorption in both the horizontal and the vertical plane indicate that small contact angle between the absorbent fibre and the liquid, and a small inter-fibre pore size are important. Some fluid parameters such as viscosity affect the rate of absorption but not the final absorption capacity. There appears to be little comparability between results obtained for the same absorbent and fluid using different test procedures. Test samples of materials from several classes of potential absorbents have been evaluated in this study, and shown to have a wide range of absorbent capacities. Foams, natural fibres, artificial fibres and granular materials are all potentially useful absorbents, with capacities ranging from as little as 0.86 to as much as 40.6 grams of distilled water per gram of absorbent. Two experimental procedures for evaluating the absorbent capacity of these materials have been detailed in this report, and found suitable for evaluating granular, fibrous or foam materials. Compression of the absorbent material reduces its capacity, but parameters such as relative humidity, pH, temperature, and viscosity appear to have little significant influence on capacity. When the materials were loaded to 50% of their one-minute absorbency, subsequent loss of the absorbed liquid was generally minimal. All of the absorbent materials rapidly lost their absorbed water through evaporation within twenty-four hours in still air at 21 degrees C and 50% relative humidity

  11. Slow and Fast Light in an Electro-Absorber

    DEFF Research Database (Denmark)

    Öhman, Filip; Bermejo Ramirez, Andres; Sales, Salvador

    2006-01-01

    We demonstrate controllable and large time delay in cascaded semiconductor saturable absorbers and amplifiers. The possibility of further increasing the tuneable phase shift by utilizing field screening effects in the quantum well absorber is demonstrated.......We demonstrate controllable and large time delay in cascaded semiconductor saturable absorbers and amplifiers. The possibility of further increasing the tuneable phase shift by utilizing field screening effects in the quantum well absorber is demonstrated....

  12. Airborne and total gamma absorbed dose rates at Patiala - India

    International Nuclear Information System (INIS)

    Tesfaye, Tilahun; Sahota, H.S.; Singh, K.

    1999-01-01

    The external gamma absorbed dose rate due to gamma rays originating from gamma emitting aerosols in air, is compared with the total external gamma absorbed dose rate at the Physics Department of Punjabi University, Patiala. It has been found out that the contribution, to the total external gamma absorbed dose rate, of radionuclides on particulate matter suspended in air is about 20% of the overall gamma absorbed dose rate. (author)

  13. CRA Grade Inflation

    OpenAIRE

    Kenneth H. Thomas

    2000-01-01

    Community Reinvestment Act of 1977 (CRA) ratings and performance evaluations are the only bank and thrift exam findings disclosed by financial institution regulators. Inflation of CRA ratings has been alleged by community activists for two decades, but there has been no quantification or empirical investigation of grade inflation. Using a unique grade inflation methodology on actual ratings and evaluation data for 1,407 small banks and thrifts under the revised CRA regulations, this paper con...

  14. Functionally graded materials

    CERN Document Server

    Mahamood, Rasheedat Modupe

    2017-01-01

    This book presents the concept of functionally graded materials as well as their use and different fabrication processes. The authors describe the use of additive manufacturing technology for the production of very complex parts directly from the three dimension computer aided design of the part by adding material layer after layer. A case study is also presented in the book on the experimental analysis of functionally graded material using laser metal deposition process.

  15. [Absorbable coronary stents. New promising technology].

    Science.gov (United States)

    Erbel, Raimund; Böse, Dirk; Haude, Michael; Kordish, Igor; Churzidze, Sofia; Malyar, Nasser; Konorza, Thomas; Sack, Stefan

    2007-06-01

    Coronary stent implantation started in Germany 20 years ago. In the beginning, the progress was very slow and accelerated 10 years later. Meanwhile, coronary stent implantation is a standard procedure in interventional cardiology. From the beginning of permanent stent implantation, research started to provide temporary stenting of coronary arteries, first with catheter-based systems, later with stent-alone technology. Stents were produced from polymers or metal. The first polymer stent implantation failed except the Igaki-Tamai stent in Japan. Newly developed absorbable polymer stents seem to be very promising, as intravascular ultrasound (IVUS) and optical coherence tomography have demonstrated. Temporary metal stents were developed based on iron and magnesium. Currently, the iron stent is tested in peripheral arteries. The absorbable magnesium stent (Biotronik, Berlin, Germany) was tested in peripheral arteries below the knee and meanwhile in the multicenter international PROGRESS-AMS (Clinical Performance and Angiographic Results of Coronary Stenting with Absorbable Metal Stents) study. The first magnesium stent implantation was performed on July 30, 2004 after extended experimental testing in Essen. The magnesium stent behaved like a bare-metal stent with low recoil of 5-7%. The stent struts were absorbed when tested with IVUS. Stent struts were not visible by fluoroscopy or computed tomography (CT) as well as magnetic resonance imaging (MRI). That means, that the magnesium stent is invisible and therefore CT and MRI can be used for imaging of interventions. Only using micro-CT the stent struts were visible. The absorption process could be demonstrated in a patient 18 days after implantation due to suspected acute coronary syndrome, which was excluded. IVUS showed a nice open lumen. Stent struts were no longer visible, but replaced by tissue indicating the previous stent location. Coronary angiography after 4 months showed an ischemia-driven target lesion

  16. 21 CFR 880.5300 - Medical absorbent fiber.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Medical absorbent fiber. 880.5300 Section 880.5300 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Devices § 880.5300 Medical absorbent fiber. (a) Identification. A medical absorbent fiber is a device...

  17. Interface properties of MIS structures based on hetero-epitaxial graded-gap Hg1-xCdxTe with CdTe interlayer created in situ during MBE growth

    Science.gov (United States)

    Voitsekhovskii, Alexander V.; Nesmelov, Sergey N.; Dzyadukh, Stanislav M.; Varavin, Vasily S.; Dvoretsky, Sergey A.; Mikhailov, Nikolay N.; Yakushev, Maksim V.; Sidorov, Georgy Yu.

    2017-11-01

    Heterostructures based on n-Hg1-xCdxTe (x = 0.23-0.40) with near-surface graded-gap layers were grown by molecular beam epitaxy on Si (013) substrates. At 77 K, the admittance of the In/Al2O3/Hg1-xCdxTe metal-insulator-semiconductor (MIS) structures with grown in situ CdTe intermediate layer and without such a layer was investigated. It has been established that MIS structures of In/Al2O3/Hg1-xCdxTe with an interlayer of in situ grown CdTe are characterized by the electrical strength of the dielectric and the qualitative interface. The hysteresis of the capacitive characteristics is practically absent within a small range of variation in the bias voltage. The density of fast surface states at the minimum does not exceed 2.2 × 1010 eV-1 cm-2. MIS structures of In/Al2O3/Hg1-xCdxTe without an intermediate layer of CdTe have significantly higher densities of fast and slow surface states, as well as lower values of the differential resistance of the space-charge region in the regime of strong inversion.

  18. Piston-rotaxanes as molecular shock absorbers.

    Science.gov (United States)

    Sevick, E M; Williams, D R M

    2010-04-20

    We describe the thermomechanical response of a new molecular system that behaves as a shock absorber. The system consists of a rodlike rotaxane connected to a piston and tethered to a surface. The response of this system is dominated by the translational entropy of the rotaxane rings and can be calculated exactly. The force laws are contrasted with those for a rigid rod and a polymer. In some cases, the rotaxanes undergo a sudden transition to a tilted state when compressed. These piston-rotaxanes provide a potential motif for the design of a new class of materials with a novel thermomechanical response.

  19. DHCAL with Minimal Absorber: Measurements with Positrons

    CERN Document Server

    Freund, B; Repond, J.; Schlereth, J.; Xia, L.; Dotti, A.; Grefe, C.; Ivantchenko, V.; Antequera, J.Berenguer; Calvo Alamillo, E.; Fouz, M.C.; Marin, J.; Puerta-Pelayo, J.; Verdugo, A.; Brianne, E.; Ebrahimi, A.; Gadow, K.; Göttlicher, P.; Günter, C.; Hartbrich, O.; Hermberg, B.; Irles, A.; Krivan, F.; Krüger, K.; Kvasnicka, J.; Lu, S.; Lutz, B.; Morgunov, V.; Provenza, A.; Reinecke, M.; Sefkow, F.; Schuwalow, S.; Tran, H.L.; Garutti, E.; Laurien, S.; Matysek, M.; Ramilli, M.; Schroeder, S.; Bilki, B.; Norbeck, E.; Northacker, D.; Onel, Y.; Cvach, J.; Gallus, P.; Havranek, M.; Janata, M.; Kovalcuk, M.; Kvasnicka, J.; Lednicky, D.; Marcisovsky, M.; Polak, I.; Popule, J.; Tomasek, L.; Tomasek, M.; Sicho, P.; Smolik, J.; Vrba, V.; Zalesak, J.; van Doren, B.; Wilson, G.W.; Kawagoe, K.; Hirai, H.; Sudo, Y.; Suehara, T.; Sumida, H.; Takada, S.; Tomita, T.; Yoshioka, T.; Bilokin, S.; Bonis, J.; Cornebise, P.; Pöschl, R.; Richard, F.; Thiebault, A.; Zerwas, D.; Hostachy, J.Y.; Morin, L.; Besson, D.; Chadeeva, M.; Danilov, M.; Markin, O.; Popova, E.; Gabriel, M.; Goecke, P.; Kiesling, C.; Kolk, N.van der; Simon, F.; Szalay, M.; Corriveau, F.; Blazey, G.C.; Dyshkant, A.; Francis, K.; Zutshi, V.; Kotera, K.; Ono, H.; Takeshita, T.; Ieki, S.; Kamiya, Y.; Ootani, W.; Shibata, N.; Jeans, D.; Komamiya, S.; Nakanishi, H.

    2016-01-01

    In special tests, the active layers of the CALICE Digital Hadron Calorimeter prototype, the DHCAL, were exposed to low energy particle beams, without being interleaved by absorber plates. The thickness of each layer corresponded approximately to 0.29 radiation lengths or 0.034 nuclear interaction lengths, defined mostly by the copper and steel skins of the detector cassettes. This paper reports on measurements performed with this device in the Fermilab test beam with positrons in the energy range of 1 to 10 GeV. The measurements are compared to simulations based on GEANT4 and a standalone program to emulate the detailed response of the active elements.

  20. Performansi Purifikasi Biogas Dengan KOH Based Absorbent

    Directory of Open Access Journals (Sweden)

    Dadang Hermawan

    2016-10-01

    Full Text Available The absorpstion of CO2 is aimed to increase the methane gas fraction in biogas. Enhancing methane fraction hopefully will increase the total energy of the biogas it self. The purification process of biogas minimizing another elements maintains combustion, especially minimizing H2O, CO2, and H2S. The purification using KOH as the absorbent to decrease the CO2. The result shown that the content of CO2 decreased into 27% from 35.5%, the average content of CH4 increased from 18% to 48.5%. Increasing KOH composition decreases bubble generator diameter and mass flow.

  1. Performansi Purifikasi Biogas Dengan KOH Based Absorbent

    OpenAIRE

    Hermawan, Dadang; Hamidi, Nurkholis; Sasongko, Mega Nur

    2016-01-01

    The absorpstion of CO2 is aimed to increase the methane gas fraction in biogas. Enhancing methane fraction hopefully will increase the total energy of the biogas it self. The purification process of biogas minimizing another elements maintains combustion, especially minimizing H2O, CO2, and H2S. The purification using KOH as the absorbent to decrease the CO2. The result shown that the content of CO2 decreased into 27% from 35.5%, the average content of CH4 increased from 18% to 48.5%. Increas...

  2. Liquid holdup in turbulent contact absorber

    International Nuclear Information System (INIS)

    Haq, A.; Zaman, M.; Inayat, M.H.; Chughtai, I.R.

    2009-01-01

    Dynamic liquid holdup in a turbulent contact absorber was obtained through quick shut off valves technique. Experiments were carried out in a Perspex column. Effects of liquid velocity, gas velocity, packing diameter packing density and packing height on dynamic liquid holdup were studied. Hollow spherical high density polyethylene (HDPE) balls were used as inert fluidized packing. Experiments were performed at practical range of liquid and gas velocities. Holdup was calculated on the basis of static bed height. Liquid holdup increases with increasing both liquid and gas velocities both for type 1 and type 2 modes of fluidization. Liquid holdup increases with packing density. No effect of dia was observed on liquid holdup. (author)

  3. Optical Pulsing in an Absorbing Liquid

    Science.gov (United States)

    Barnes, Jacob; Evans, Dean; Guha, Shekhar

    2003-03-01

    A continuous-wave laser can be converted into a series of repetitive pulses by focusing the laser beam into an absorbing liquid (e.g. nigrosine dissolved in a solvent), where the mechanism responsible for the pulses is the scattering of light off of photo-generated bubbles. The dependence of the pulsation frequency on the solvent, power, and cell thickness will be shown. The authors would like to acknowledge the contributions made by Prof. Daniel Lathrop (University of Maryland, Department of Physics) at the APS March 2002 meeting.

  4. Impedance matched thin metamaterials make metals absorbing.

    Science.gov (United States)

    Mattiucci, N; Bloemer, M J; Aközbek, N; D'Aguanno, G

    2013-11-13

    Metals are generally considered good reflectors over the entire electromagnetic spectrum up to their plasma frequency. Here we demonstrate an approach to tailor their absorbing characteristics based on the effective metamaterial properties of thin, periodic metallo-dielectric multilayers by exploiting a broadband, inherently non-resonant, surface impedance matching mechanism. Based on this mechanism, we design, fabricate and test omnidirectional, thin ( 99%) over a frequency range spanning from the UV to the IR. Our approach opens new venues to design cost effective materials for many applications such as thermo-photovoltaic energy conversion devices, light harvesting for solar cells, flat panel display, infrared detectors, stray light reduction, stealth and others.

  5. High energy model for irregular absorbing particles

    International Nuclear Information System (INIS)

    Chiappetta, Pierre.

    1979-05-01

    In the framework of a high energy formulation of relativistic quantum scattering a model is presented which describes the scattering functions and polarization of irregular absorbing particles, whose dimensions are greater than the incident wavelength. More precisely in the forward direction an amplitude parametrization of eikonal type is defined which generalizes the usual diffraction theory, and in the backward direction a reflective model is used including a shadow function. The model predictions are in good agreement with the scattering measurements off irregular compact and fluffy particles performed by Zerull, Giese and Weiss (1977)

  6. Absorbency of Superabsorbent Polymers in Cementitious Environments

    DEFF Research Database (Denmark)

    Esteves, Luis Pedro; Jensen, Ole Mejlhede

    2012-01-01

    Optimal use of superabsorbent polymers (SAP) in cement-based materials relies on knowledge on how SAP absorbency is influenced by different physical and chemical parameters. These parameters include salt concentration in the pore fluid, temperature of the system and SAP particle size. The present...... work shows experimental results on this and presents a new technique to measure the swelling of SAP particles. This new technique is compared with existing techniques that have been recently proposed for the measurement of pore fluid absorption by superabsorbent polymers. It is seen...

  7. Porphyrin Based Near Infrared-Absorbing Materials for Organic Photovoltaics

    Science.gov (United States)

    Zhong, Qiwen

    photosynthesis. Photosynthesis uses light from the sun to drive a series of chemical reactions. Most natural photosynthetic systems utilize chlorophylls to absorb light energy and carry out photochemical charge separation that stores energy in the form of chemical bonds. The sun produces a broad spectrum of light output that ranges from gamma rays to radio waves. The entire visible range of light (400-700 nm) and some wavelengths in the NIR (700-1000 nm), are highly active in driving photosynthesis. Although the most familiar chlorophyll-containing organisms, such as plants, algae and cyanobacteria, cannot use light longer than 700 nm, anoxygenic bacterium containing bacteriochlorophylls can use the NIR part of the solar spectrum. No organism is known to utilize light of wavelength longer than about 1000 nm for photosynthesis. NIR light has a very low-energy content in each photon, so that large numbers of these low-energy photons would have to be used to drive the chemical reactions of photosynthesis. This is thermodynamically possible but would require a fundamentally different molecular mechanism that is more akin to a heat engine than to photochemistry. Early work on developing light absorbing materials for OPVs was inspired by photosynthesis in which light is absorbed by chlorophyll. Structurally related to chlorophyll is the porphyrin family, which has accordingly drawn much interest as the potential light absorbing component in OPV applications. In this dissertation, the design and detail studies of several porphyrin-based NIR absorbing materials, including pi--extended perylenyl porphryins and pyrazole-containing carbaporphyrins, as well as porphyrin modified single-walled carbon nanotube hybrids, will be presented, dedicating efforts to develop novel and application-oriented materials for efficient utilization of sustainable solar energy.

  8. Thermal Evaluation of Storage Rack with an Advanced Neutron Absorber during Normal Operation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hee-Jae; Kim, Mi-Jin; Sohn, Dong-Seong [UNIST, Ulsan (Korea, Republic of)

    2016-10-15

    The storage capacity of the domestic wet storage site is expected to reach saturation from Hanbit in 2024 to Sin-wolseong in 2038 and accordingly management alternatives are urgently taken. Since installation of the dense rack is considered in the short term, it is necessary to urgently develop an advanced neutron absorber which can be applied to a spent nuclear fuel storage facility. Neutron absorber is the material for controlling the reactivity. A material which has excellent thermal neutron absorption ability, high strength and corrosion resistance must be selected as the neutron absorber. Existing neutron absorbers are made of boron which has a good thermal absorption ability such as BORAL and METAMIC. However, possible problems have been reported in using the boron-based neutron absorber for wet storage facility. Gadolinium is known to have higher neutron absorption cross-section than that of boron. And the strength of duplex stainless steel is about 1.5 times higher than stainless steel 304 which has been frequently used as a structural material. Therefore, duplex stainless steel which contains gadolinium is in consideration as an advanced neutron absorber. Temperature distribution is shown in figure 4. In pool bottom region near the inlet shows a relatively low tendency and heat generated from the fuel assemblies is transmitted to the pool upper region by the vertical flow. Also, temperature gradient appear in rack structures for the axial direction and temperature is uniformly distributed in the pool upper region. Table 1 presents the calculated results. The maximum temperature is 306.63K and does not exceed the 333.15K (60℃). The maximum temperature of the neutron absorber is 306.48K.

  9. Computational design for a wide-angle cermet-based solar selective absorber for high temperature applications

    International Nuclear Information System (INIS)

    Sakurai, Atsushi; Tanikawa, Hiroya; Yamada, Makoto

    2014-01-01

    The purpose of this study is to computationally design a wide-angle cermet-based solar selective absorber for high temperature applications by using a characteristic matrix method and a genetic algorithm. The present study investigates a solar selective absorber with tungsten–silica (W–SiO 2 ) cermet. Multilayer structures of 1, 2, 3, and 4 layers and a wide range of metal volume fractions are optimized. The predicted radiative properties show good solar performance, i.e., thermal emittances, especially beyond 2 μm, are quite low, in contrast, solar absorptance levels are successfully high with wide angular range, so that solar photons are effectively absorbed and infrared radiative heat loss can be decreased. -- Highlights: • Electromagnetic simulation of radiative properties by characteristic matrix method. • Optimization for multilayered W–SiO 2 cermet-based absorber by a Genetic Algorithm. • We propose a successfully high solar performance of solar selective absorber

  10. An ultrathin wide-band planar metamaterial absorber based on a fractal frequency selective surface and resistive film

    International Nuclear Information System (INIS)

    Fan Yue-Nong; Cheng Yong-Zhi; Nie Yan; Wang Xian; Gong Rong-Zhou

    2013-01-01

    We propose an ultrathin wide-band metamaterial absorber (MA) based on a Minkowski (MIK) fractal frequency selective surface and resistive film. This absorber consists of a periodic arrangement of dielectric substrates sandwiched with an MIK fractal loop structure electric resonator and a resistive film. The finite element method is used to simulate and analyze the absorption of the MA. Compared with the MA-backed copper film, the designed MA-backed resistive film exhibits an absorption of 90% at a frequency region of 2 GHz–20 GHz. The power loss density distribution of the MA is further illustrated to explain the mechanism of the proposed MA. Simulated absorptions at different incidence cases indicate that this absorber is polarization-insensitive and wide-angled. Finally, further simulated results indicate that the surface resistance of the resistive film and the dielectric constant of the substrate can affect the absorbing property of the MA. This absorber may be used in many military fields

  11. Synthesis and characterization of electrolyte-grade 10%Gd-doped ceria thin film/ceramic substrate structures for solid oxide fuel cells

    DEFF Research Database (Denmark)

    Chourashiya, M. G.; Bharadwaj, S. R.; Jadhav, L. D.

    2010-01-01

    In the present research, spray pyrolysis technique is employed to synthesize 10%Gd-doped ceria (GDC) thin films on ceramic substrates with an intention to use the "film/substrate" structure in solid oxide fuel cells. GDC films deposited on GDC substrate showed enhanced crystallite formation....... In case of NiO-GDC composite substrate, the thickness of film was higher (∼ 13 μm) as compared to the film thickness on GDC substrate (∼ 2 μm). The relative density of the films deposited on both the substrates was of the order of 95%. The impedance measurements revealed that ionic conductivity of GDC...

  12. Report on Understanding and Predicting Effects of Thermal Aging on Microstructure and Tensile Properties of Grade 91 Steel for Structural Components

    Energy Technology Data Exchange (ETDEWEB)

    Li, Meimei [Argonne National Lab. (ANL), Argonne, IL (United States); Natesan, K. [Argonne National Lab. (ANL), Argonne, IL (United States); Chen, Weiying [Argonne National Lab. (ANL), Argonne, IL (United States)

    2017-08-01

    This report provides an update on understanding and predicting the effects of long-term thermal aging on microstructure and tensile properties of G91 to corroborate the ASME Code rules in strength reduction due to elevated temperature service. The research is to support the design and long-term operation of G91 structural components in sodium-cooled fast reactors (SFRs). The report is a Level 2 deliverable in FY17 (M2AT-17AN1602017), under the Work Package AT-17AN160201, “SFR Materials Testing” performed by the Argonne National Laboratory (ANL), as part of the Advanced Reactor Technologies Program.

  13. Computed a multiple band metamaterial absorber and its application based on the figure of merit value

    Science.gov (United States)

    Chen, Chao; Sheng, Yuping; Jun, Wang

    2018-01-01

    A high performed multiple band metamaterial absorber is designed and computed through the software Ansofts HFSS 10.0, which is constituted with two kinds of separated metal particles sub-structures. The multiple band absorption property of the metamaterial absorber is based on the resonance of localized surface plasmon (LSP) modes excited near edges of metal particles. The damping constant of gold layer is optimized to obtain a near-perfect absorption rate. Four kinds of dielectric layers is computed to achieve the perfect absorption perform. The perfect absorption perform of the metamaterial absorber is enhanced through optimizing the structural parameters (R = 75 nm, w = 80 nm). Moreover, a perfect absorption band is achieved because of the plasmonic hybridization phenomenon between LSP modes. The designed metamaterial absorber shows high sensitive in the changed of the refractive index of the liquid. A liquid refractive index sensor strategy is proposed based on the computed figure of merit (FOM) value of the metamaterial absorber. High FOM values (116, 111, and 108) are achieved with three liquid (Methanol, Carbon tetrachloride, and Carbon disulfide).

  14. Kindergarten Predictors of Third Grade Writing

    Science.gov (United States)

    Kim, Young-Suk; Al Otaiba, Stephanie; Wanzek, Jeanne

    2015-01-01

    The primary goal of the present study was to examine the relations of kindergarten transcription, oral language, word reading, and attention skills to writing skills in third grade. Children (N = 157) were assessed on their letter writing automaticity, spelling, oral language, word reading, and attention in kindergarten. Then, they were assessed on writing in third grade using three writing tasks – one narrative and two expository prompts. Children’s written compositions were evaluated in terms of writing quality (the extent to which ideas were developed and presented in an organized manner). Structural equation modeling showed that kindergarten oral language and lexical literacy skills (i.e., word reading and spelling) were independently predicted third grade narrative writing quality, and kindergarten literacy skill uniquely predicted third grade expository writing quality. In contrast, attention and letter writing automaticity were not directly related to writing quality in either narrative or expository genre. These results are discussed in light of theoretical and practical implications. PMID:25642118

  15. Wave energy extraction by coupled resonant absorbers.

    Science.gov (United States)

    Evans, D V; Porter, R

    2012-01-28

    In this article, a range of problems and theories will be introduced that will build towards a new wave energy converter (WEC) concept, with the acronym 'ROTA' standing for resonant over-topping absorber. First, classical results for wave power absorption for WECs constrained to operate in a single degree of freedom will be reviewed and the role of resonance in their operation highlighted. Emphasis will then be placed on how the introduction of further resonances can improve power take-off characteristics by extending the range of frequencies over which the efficiency is close to a theoretical maximum. Methods for doing this in different types of WECs will be demonstrated. Coupled resonant absorbers achieve this by connecting a WEC device equipped with its own resonance (determined from a hydrodynamic analysis) to a new system having separate mass/spring/damper characteristics. It is shown that a coupled resonant effect can be realized by inserting a water tank into a WEC, and this idea forms the basis of the ROTA device. In essence, the idea is to exploit the coupling between the natural sloshing frequencies of the water in the internal tank and the natural resonance of a submerged buoyant circular cylinder device that is tethered to the sea floor, allowing a rotary motion about its axis of attachment.

  16. Erbium concentration dependent absorbance in tellurite glass

    Energy Technology Data Exchange (ETDEWEB)

    Sazali, E. S., E-mail: mdsupar@utm; Rohani, M. S., E-mail: mdsupar@utm; Sahar, M. R., E-mail: mdsupar@utm; Arifin, R., E-mail: mdsupar@utm; Ghoshal, S. K., E-mail: mdsupar@utm; Hamzah, K., E-mail: mdsupar@utm [Advanced Optical Material Research Group, Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, 81310, Skudai, Johor Bahru, Johor (Malaysia)

    2014-09-25

    Enhancing the optical absorption cross-section in topically important rare earth doped tellurite glasses is challenging for photonic devices. Controlled synthesis and detailed characterizations of the optical properties of these glasses are important for the optimization. The influence of varying concentration of Er{sup 3+} ions on the absorbance characteristics of lead tellurite glasses synthesized via melt-quenching technique are investigated. The UV-Vis absorption spectra exhibits six prominent peaks centered at 490, 526, 652, 800, 982 and 1520 nm ascribed to the transitions in erbium ion from the ground state to the excited states {sup 4}F{sub 7/2}, {sup 2}H{sub 11/2}, {sup 4}F{sub 9/2}, {sup 4}I{sub 9/2}, {sup 2}H{sub 11/2} and {sup 4}I{sub 13/2}, respectively. The results are analyzed by means of optical band gap E{sub g} and Urbach energy E{sub u}. The values of the energy band gap are found decreased from 2.82 to 2.51 eV and the Urbach energy increased from 0.15 to 0.24 eV with the increase of the Er{sub 2}O{sub 3} concentration from 0 to 1.5 mol%. The excellent absorbance of the prepared tellurite glasses makes them suitable for fabricating solid state lasers.

  17. Possible Quantum Absorber Effects in Cortical Synchronization

    Science.gov (United States)

    Kämpf, Uwe

    The Wheeler-Feynman transactional "absorber" approach was proposed originally to account for anomalous resonance coupling between spatio-temporally distant measurement partners in entangled quantum states of so-called Einstein-Podolsky-Rosen paradoxes, e.g. of spatio-temporal non-locality, quantum teleportation, etc. Applied to quantum brain dynamics, however, this view provides an anticipative resonance coupling model for aspects of cortical synchronization and recurrent visual action control. It is proposed to consider the registered activation patterns of neuronal loops in so-called synfire chains not as a result of retarded brain communication processes, but rather as surface effects of a system of standing waves generated in the depth of visual processing. According to this view, they arise from a counterbalance between the actual input's delayed bottom-up data streams and top-down recurrent information-processing of advanced anticipative signals in a Wheeler-Feynman-type absorber mode. In the framework of a "time-loop" model, findings about mirror neurons in the brain cortex are suggested to be at least partially associated with temporal rather than spatial mirror functions of visual processing, similar to phase conjugate adaptive resonance-coupling in nonlinear optics.

  18. Spacesuit Evaporator-Absorber-Radiator (SEAR)

    Science.gov (United States)

    Hodgson, Ed; Izenson, Mike; Chan, Weibo; Bue, Grant C.

    2012-01-01

    For decades advanced spacesuit developers have pursued a regenerable, robust nonventing system for heat rejection. Toward this end, this paper investigates linking together two previously developed technologies, namely NASA s Spacesuit Water Membrane Evaporator (SWME), and Creare s Lithium Chloride Absorber Radiator (LCAR). Heat from a liquid cooled garment is transported to SWME that provides cooling through evaporation. This water vapor is then captured by solid LiCl in the LCAR with a high enthalpy of absorption, resulting in sufficient temperature lift to reject heat to space by radiation. After the sortie, the LCAR would be heated up and dried in a regenerator to drive off and recover the absorbed evaporant. A engineering development prototype was built and tested in vacuum conditions at a sink temperature of 250 K. The LCAR was able to stably reject 75 W over a 7-hour period. A conceptual design of a full-scale radiator is proposed. Excess heat rejection above 240 W would be accomplished through venting of the evaporant. Loop closure rates were predicted for various exploration environment scenarios.

  19. Pregnant woman mode for absorbed fraction calculations

    International Nuclear Information System (INIS)

    Cloutier, R.J.; Snyder, W.S.; Watson, E.E.

    1977-01-01

    The most radiation-sensitive segment of our population is the developing fetus. Until recently, methods available for calculating the dose to the fetus were inadequate because a model for the pregnant woman was not available. Instead, the Snyder and Fisher model of Reference Man, which includes a uterus, was frequently used to calculate absorbed fractions when the source was in various organs of the body and the nongravid uterus was the target. These values would be representative of the dose to the embryo during the early stages of pregnancy. Unfortunately, Reference Man is considerable larger than Reference Woman. The authors recently reported on the design of a Reference Woman phantom that has dimensions quite similar to the ICRP Reference Woman. This phantom was suitable for calculating the dose to the embryo during early stages of pregnancy (0 to 3 mo.), but was not suitable for the later stages of pregnancy because of the changing shape of the mother and the displacement of several abdominal organs brought about by the growth of the uterus and fetus. The models of Reference Woman that were subsequently developed for each month of pregnancy are described. The models take into account the growth of the uterus and fetus and the repositioning of the various abdominal organs. These models have been used to calculate absorbed fractions for the fetus as a target and the gastrointestinal tract as a source of radiation for twelve photon energies ranging from 10 keV to 4 MeV

  20. Evaluation of Grade 120 Granulated Ground blast Furnace Slag.

    Science.gov (United States)

    1999-06-01

    This study evaluates Grade 120 Granulated Ground Blast Furnace Slag (GGBFS) and its effect on the properties of hydraulic cement concretes used in structural and pavement construction. Several mix designs, structural and pavement, were used for this ...

  1. High-efficiency ventilated metamaterial absorber at low frequency

    Science.gov (United States)

    Wu, Xiaoxiao; Au-Yeung, Ka Yan; Li, Xin; Roberts, Robert Christopher; Tian, Jingxuan; Hu, Chuandeng; Huang, Yingzhou; Wang, Shuxia; Yang, Zhiyu; Wen, Weijia

    2018-03-01

    We demonstrate a ventilated metamaterial absorber operating at low frequency (90%) has been achieved in both simulations and experiments. This high-efficiency absorption under the ventilation condition originates from the weak coupling of two identical split tube resonators constituting the absorber, which leads to the hybridization of the degenerate eigenmodes and breaks the absorption upper limit of 50% for conventional transmissive symmetric acoustic absorbers. The absorber can also be extended to an array and work in free space. The absorber should have potential applications in acoustic engineering where both noise reduction and ventilation are required.

  2. Absorber Alignment Measurement Tool for Solar Parabolic Trough Collectors: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Stynes, J. K.; Ihas, B.

    2012-04-01

    As we pursue efforts to lower the capital and installation costs of parabolic trough solar collectors, it is essential to maintain high optical performance. While there are many optical tools available to measure the reflector slope errors of parabolic trough solar collectors, there are few tools to measure the absorber alignment. A new method is presented here to measure the absorber alignment in two dimensions to within 0.5 cm. The absorber alignment is measured using a digital camera and four photogrammetric targets. Physical contact with the receiver absorber or glass is not necessary. The alignment of the absorber is measured along its full length so that sagging of the absorber can be quantified with this technique. The resulting absorber alignment measurement provides critical information required to accurately determine the intercept factor of a collector.

  3. Thermal Shielding Effects of a Damaged Shock Absorber and an Intact Shock Absorber

    Energy Technology Data Exchange (ETDEWEB)

    Bang, K. S.; Lee, J. C.; Kim, K. Y.; Seo, C. S.; Seo, K. S. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2011-05-15

    In order to safely transport the radioactive waste arising from the hot test of an ACP(Advanced Spent Fuel Conditioning Process) a shipping package is required. Therefore, KAERI is developing a shipping package to transport the radioactive waste arising from the ACPF during a hot test. The regulatory requirements for a Type B package are specified in the Korea Most Act 2009-37, IAEA Safety Standard Series No. TS-R-1, and US 10 CFR Part. These regulatory guidelines classify the hot cell cask as a Type B package, and state that the Type B package for transporting radioactive materials should be able to withstand a test sequence consisting of a 9 m drop onto an unyielding surface, a 1 m drop onto a puncture bar, and a 30 minute fully engulfing fire. Greiner et al. investigated the thermal protection provided by shock absorbers by using the CAFE computer code. To evaluate the thermal shielding effect of the shock absorber, the thermal test was performed by using a 1/2 scale model with a shock absorber which was damaged by both a 9 m drop test and a 1 m puncture test. For the purpose of comparison, the thermal test was also carried out by using a 1/2 scale model with the intact shock absorber

  4. Tunable THz perfect absorber with two absorption peaks based on graphene microribbons

    DEFF Research Database (Denmark)

    Gu, Mingyue; Xiao, Binggang; Xiao, Sanshui

    2018-01-01

    Perfect absorption is characterised by the complete suppression of incident and reflected electromagnetic wave, and complete dissipation of the incident energy. A tunable perfect terahertz (THz) absorber with two absorption peaks based on graphene is presented. The proposed structure consists of ...

  5. Water-cooled Pb-17Li test blanket module for ITER: impact of the structural material grade on the neutronic responses

    Energy Technology Data Exchange (ETDEWEB)

    Vella, G.; Aiello, G.; Oliveri, E. [Palermo Univ. (Italy). Dipt. di Ingegneria Nucl.; Fuetterer, M.A.; Giancarli, L. [CEA - Saclay, DRN/DMT/SERMA, Gif-sur-Yvette (France); Tavassoli, F. [CEA - Saclay, CEREM, Gif-sur-Yvette (France)

    1998-10-01

    The water-cooled lithium lead (WCLL) DEMO blanket is one of the two EU lines to be further developed with the aim of manufacturing by 2010 a test blanket module for ITER (TBM). In this paper results of a 3D-Monte Carlo neutronic analysis of the TBM design are reported. A fully 3D heterogeneous model of the WCLL-TBM has been inserted into an existing ITER model accounting for a proper D-T neutron source. The structural material assumed for the calculations was martensitic 9% Cr steel code named Z 10 CDV Nb 9-1. Results have been compared with those obtained using MANET. The main nuclear responses of the TBM have been determined, such as detailed power deposition density, material damage through DPA and He and H gas production rate, radial distribution of tritium production rate and total tritium production in the module. The impact of using natural lithium on the TBM system operation has also been evaluated. (orig.) 13 refs.

  6. Principle of a 'retro reflecting' or 'backfire' LH antenna. A robust efficiently cooled launching structure for LH waves in reactor grade plasmas

    International Nuclear Information System (INIS)

    Bibet, Ph.; Litaudon, X.; Moreau, D.

    1994-01-01

    Up to now, lower hybrid current drive launchers have been made of waveguide arrays. To extrapolate present techniques despite the thermal power load and the mechanical stress, it is necessary to develop an advanced launcher concept which is simpler and more robust. To simplify the antennas between RF vacuum windows and plasma, studies have been carried, for example, the hyperguide for JET, the toroidal oversized waveguide for JT-60U and the poloidal mode converter for Tore Supra. For plasma-facing components, it has been proposed to use diffraction through rod arrays although this suffers from bad coupling per pass. Here a new concept is given which seems to be robust, and should leave enough space for efficient water cooling. The front part near plasma can be easily replaced by remote handling. Its principle is explained, and the description is made. The coupling properties of the proposed structure have been studied by using the SWAN code, and good agreement between the SWAN calculation and the coupling measurement performed at Tore Supra has been reported previously. (K.I.)

  7. Shock absorbing properties of toroidal shells under compression, 3

    International Nuclear Information System (INIS)

    Sugita, Yuji

    1985-01-01

    The author has previously presented the static load-deflection relations of a toroidal shell subjected to axisymmetric compression between rigid plates and those of its outer half when subjected to lateral compression. In both these cases, the analytical method was based on the incremental Rayleigh-Ritz method. In this paper, the effects of compression angle and strain rate on the load-deflection relations of the toroidal shell are investigated for its use as a shock absorber for the radioactive material shipping cask which must keep its structural integrity even after accidental falls at any angle. Static compression tests have been carried out at four angles of compression, 10 0 , 20 0 , 50 0 , 90 0 and the applications of the preceding analytical method have been discussed. Dynamic compression tests have also been performed using the free-falling drop hammer. The results are compared with those in the static compression tests. (author)

  8. Flexible metamaterial absorbers for stealth applications at terahertz frequencies.

    Science.gov (United States)

    Iwaszczuk, Krzysztof; Strikwerda, Andrew C; Fan, Kebin; Zhang, Xin; Averitt, Richard D; Jepsen, Peter Uhd

    2012-01-02

    We have wrapped metallic cylinders with strongly absorbing metamaterials. These resonant structures, which are patterned on flexible substrates, smoothly coat the cylinder and give it an electromagnetic response designed to minimize its radar cross section. We compare the normal-incidence, small-beam reflection coefficient with the measurement of the far-field bistatic radar cross section of the sample, using a quasi-planar THz wave with a beam diameter significantly larger than the sample dimensions. In this geometry we demonstrate a near-400-fold reduction of the radar cross section at the design frequency of 0.87 THz. In addition we discuss the effect of finite sample dimensions and the spatial dependence of the reflection spectrum of the metamaterial.

  9. EM wave propagation analysis in plasma covered radar absorbing material

    CERN Document Server

    Singh, Hema; Rawat, Harish Singh

    2017-01-01

    This book focuses on EM propagation characteristics within multilayered plasma-dielectric-metallic media. The method used for analysis is impedance transformation method. Plasma covered radar absorbing material is approximated as a multi-layered dielectric medium. The plasma is considered to be bounded homogeneous/inhomogeneous medium. The reflection coefficient and hence return loss is analytically derived. The role of plasma parameters, such as electron density, collision frequency, plasma thickness, and plasma density profile in the absorption behavior of multi-layered plasma-RAM structure is described. This book provides a clearer picture of EM propagation within plasma. The reader will get an insight of plasma parameters that play significant role in deciding the absorption characteristics of plasma covered surfaces.

  10. ADAPTIVE OPTICS IMAGING OF A MASSIVE GALAXY ASSOCIATED WITH A METAL-RICH ABSORBER

    International Nuclear Information System (INIS)

    Chun, Mark R.; Kulkarni, Varsha P.; Gharanfoli, Soheila; Takamiya, Marianne

    2010-01-01

    The damped and sub-damped Lyα absorption (DLA and sub-DLA) line systems in quasar spectra are believed to be produced by intervening galaxies. However, the connection of quasar absorbers to galaxies is not well-understood, since attempts to image the absorbing galaxies have often failed. While most DLAs appear to be metal poor, a population of metal-rich absorbers, mostly sub-DLAs, has been discovered in recent studies. Here we report high-resolution K-band imaging with the Keck laser guide star adaptive optics (LGSAO) system of the field of quasar SDSSJ1323-0021 in search of the galaxy producing the z = 0.72 sub-DLA absorber. With a metallicity of 2-4 times the solar level, this absorber is one of the most metal-rich systems found to date. Our data show a large bright galaxy with an angular separation of only 1.''25 from the quasar, well-resolved from the quasar at the high resolution of our data. The galaxy has a magnitude of K = 17.6-17.9, which corresponds to a luminosity of ∼3-6 L*. Morphologically, the galaxy is fitted with a model with an effective radius, enclosing half of the total light, of R e = 4 kpc and a bulge-to-total ratio of 0.4-1.0, indicating a substantial bulge stellar population. Based on the mass-metallicity relation of nearby galaxies, the absorber galaxy appears to have a stellar mass of ∼>10 11 M sun . Given the small impact parameter (9.0 kpc at the absorber redshift), this massive galaxy appears to be responsible for the metal-rich sub-DLA. The absorber galaxy is consistent with the metallicity-luminosity relation observed for nearby galaxies, but is near the upper end of metallicity. Our study marks the first application of LGSAO for the study of the structure of galaxies producing distant quasar absorbers. Finally, this study offers the first example of a massive galaxy with a substantial bulge producing a metal-rich absorber.

  11. Disposition of weapons-grade plutonium in Westinghouse reactors

    International Nuclear Information System (INIS)

    Alsaed, A.A.; Adams, M.

    1998-03-01

    The authors have studied the feasibility of using weapons-grade plutonium in the form of mixed-oxide (MOX) fuel in existing Westinghouse reactors. They have designed three transition Cycles from an all LEU core to a partial MOX core. They found that four-loop Westinghouse reactors such as the Vogtle power plant are capable of handling up to 45 percent weapons-grade MOX loading without any modifications. The authors have also designed two kinds of weapons-grade MOX assemblies with three enrichments per assembly and four total enrichments. Wet annular burnable absorber (WABA) rods were used in all the MOX feed assemblies, some burned MOX assemblies, and some LEU feed assemblies. Integral fuel burnable absorber (IFBA) was used in the rest of the LEU feed assemblies. The average discharge burnup of MOX assemblies was over 47,000 MWD/MTM, which is more than enough to meet the open-quotes spent fuel standard.close quotes One unit is capable of consuming 0.462 MT of weapons-grade plutonium per year. Preliminary analyses showed that important reactor physics parameters for the three transitions cycles are comparable to those of LEU cores including boron levels, reactivity coefficients, peaking factors, and shutdown margins. Further transient analyses will need to be performed

  12. Contractions from grading

    Science.gov (United States)

    Krishnan, Chethan; Raju, Avinash

    2018-04-01

    We note that large classes of contractions of algebras that arise in physics can be understood purely algebraically via identifying appropriate Zm-gradings (and their generalizations) on the parent algebra. This includes various types of flat space/Carroll limits of finite and infinite dimensional (A)dS algebras, as well as Galilean and Galilean conformal algebras. Our observations can be regarded as providing a natural context for the Grassmann approach of Krishnan et al. [J. High Energy Phys. 2014(3), 36]. We also introduce a related notion, which we call partial grading, that arises naturally in this context.

  13. Shock absorbing evaluation of the rigid polyurethane foam and styrofoam applied to a small transportation package

    International Nuclear Information System (INIS)

    Seo, K.S.; Lee, J.C.; Bang, K.S.; Han, H.S.; Chung, S.H.; Choi, B.I.; Ha, J.H.

    2004-01-01

    The package design objectives for the drop condition are to maintain the integrity of the structural material by reducing the impact force. There are two kinds of the shock absorbing materials such as rigid polyurethane foam (PU) and Styrofoam (EPS: Expanded Poly Styrene). These materials are generally used in small transportation packages. The stress-strain curves were obtained by the compression tests until the PU and EPS reached their lock-up strain. This paper describes that, in the case of a small transportation package of a cylindrical shape, the shock absorbing effects were evaluated by utilizing the compression properties of the PU and EPS foam

  14. Covering that selectively absorbs visible and infrared radiation, and method for the production thereof

    OpenAIRE

    Céspedes, Eva; Prieto, C.; Escobar Galindo, R.; Sánchez-García, J. A.

    2011-01-01

    [EN] The present invention relates to a covering that selectively absorbs visible and infrared radiation, which comprises: (a) a first anti-diffusion barrier layer (2); (b) an IR-reflecting metallic layer (3) made from at least one metallic element selected from a group comprising Au, Ag, Al, Cu, Ti and Pt; (c) at least a second anti-diffusion barrier layer (4) formed by oxidation of the layer (3); (d) a structure that absorbs in the UV-VIS range, which comprises at least a first film (5) and...

  15. Electromagnetic radiation absorbers and modulators comprising polyaniline

    Science.gov (United States)

    Epstein, Arthur J.; Ginder, John M.; Roe, Mitchell G.; Hajiseyedjavadi, Hamid

    1992-01-01

    A composition for absorbing electromagnetic radiation, wherein said electromagnetic radiation possesses a wavelength generally in the range of from about 1000 Angstroms to about 50 meters, wherein said composition comprises a polyaniline composition of the formula ##STR1## where y can be equal to or greater than zero, and R.sup.1 and R.sup.2 are independently selected from the group containing of H, --OCH.sub.3, --CH.sub.3, --F, --Cl, --Br, --I, NR.sup.3 .sub.2, --NHCOR.sup.3, --OH, --O.sup.-, SR.sup.3, --OCOR.sup.3, --NO.sub.2, --COOH, --COOR.sup.3, --COR.sup.3, --CHO, and --CN, where R.sup.3 is a C.sub.1 to C.sub.8 alkyl, aryl or aralkyl group.

  16. Modelling and validation of electromechanical shock absorbers

    Science.gov (United States)

    Tonoli, Andrea; Amati, Nicola; Girardello Detoni, Joaquim; Galluzzi, Renato; Gasparin, Enrico

    2013-08-01

    Electromechanical vehicle suspension systems represent a promising substitute to conventional hydraulic solutions. However, the design of electromechanical devices that are able to supply high damping forces without exceeding geometric dimension and mass constraints is a difficult task. All these challenges meet in off-road vehicle suspension systems, where the power density of the dampers is a crucial parameter. In this context, the present paper outlines a particular shock absorber configuration where a suitable electric machine and a transmission mechanism are utilised to meet off-road vehicle requirements. A dynamic model is used to represent the device. Subsequently, experimental tests are performed on an actual prototype to verify the functionality of the damper and validate the proposed model.

  17. Novel active vibration absorber with magnetorheological fluid

    Energy Technology Data Exchange (ETDEWEB)

    Gerlach, T; Ehrlich, J; Boese, H [Fraunhofer-Institut fuer Silicatforschung ISC, Neunerplatz 2, D-97082 Wuerzburg (Germany)], E-mail: thomas.gerlach@isc.fraunhofer.de

    2009-02-01

    Disturbing vibrations diminish the performance of technical high precision devices significantly. In search of a suitable solution for reducing these vibrations, a novel concept of active vibration reduction was developed which exploits the special properties of magnetorheological fluids. In order to evaluate the concept of such an active vibration absorber (AVA) a demonstrator was designed and manufactured. This demonstrator generates a force which counteracts the motion of the vibrating body. Since the counterforce is generated by a centrifugal exciter, the AVA provides the capability to compensate vibrations even in two dimensions. To control the strength of the force transmitted to the vibrating body, the exciter is based on a tunable MR coupling. The AVA was integrated in an appropriate testing device to investigate its performance. The recorded results show a significant reduction of the vibration amplitudes by an order of magnitude.

  18. Moisture buffering capacity of highly absorbing materials

    Energy Technology Data Exchange (ETDEWEB)

    Cerolini, S.; D' Orazio, M.; Stazi, A. [Department of Architecture, Construction and Structures (DACS), Faculty of Engineering, Polytechnic University of Marche, Via Brecce Bianche, 60100 Ancona (Italy); Di Perna, C. [Department of Energetics, Faculty of Engineering, Polytechnic University of Marche, Via Brecce Bianche, 60100 Ancona (Italy)

    2009-02-15

    This research investigates the possibility to use highly absorbing materials to dampen indoor RH% variations. The practical MBV of sodium polyacrylate, cellulose-based material, perlite and gypsum is evaluated for a daily cyclic exposure that alternates high (75%) and low (33%) RH% levels for 8 h and 16 h, respectively. The adjustment velocity to RH% variations and the presence of hysteretic phenomena are also presented. The cellulose-based material proves to be the most suitable for moisture buffering applications. Starting from this material's properties, the effect of thickness, vapour resistance factor ({mu}) and mass surface exchange coefficient (Z{sub v}) on sorption capacity is evaluated by the use of a numerical model. (author)

  19. Transport in coherently absorbing or amplifying media

    International Nuclear Information System (INIS)

    Sen, A.K.

    1995-11-01

    We study electronic transport in a one-dimensional ordered chain in the presence of either absorption or amplification at each site (the site-potential having an imaginary positive or negative part) within a single-band tightbinding Hamiltonian. The spectrum in either case for the isolated (closed) quantum system is found to become broader compared to the regular Bloch case where there is no absorption or amplification at any site. Interestingly for the transport through an infinitely long ordered chain (open quantum system), the reflectance saturates to a value greater (lesser) than unity in the amplifying (absorbing) case and the transmittance decays to zero in either case. This fact implies that the transmittance does not grow indefinitely even for an ordered, amplifying (active or lasing) medium and that it is not necessary to have any disorder or interaction induced confining mechanism on the transmitted wave, so as to achieve an amplification in the backscattered wave. (author). 8 refs, 2 figs

  20. Neutron absorbed dose in a pacemaker CMOS

    Energy Technology Data Exchange (ETDEWEB)

    Borja H, C. G.; Guzman G, K. A.; Valero L, C. Y.; Banuelos F, A.; Hernandez D, V. M.; Vega C, H. R. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Calle Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico); Paredes G, L., E-mail: candy_borja@hotmail.com [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2011-11-15

    The absorbed dose due to neutrons by a Complementary Metal Oxide Semiconductor (CMOS) has been estimated using Monte Carlo methods. Eventually a person with a pacemaker becomes a patient that must be treated by radiotherapy with a linear accelerator; the pacemaker has integrated circuits as CMOS that are sensitive to intense and pulsed radiation fields. When the Linac is working in Bremsstrahlung mode an undesirable neutron field is produced due to photoneutron reactions; these neutrons could damage the CMOS putting the patient at risk during the radiotherapy treatment. In order to estimate the neutron dose in the CMOS a Monte Carlo calculation was carried out where a full radiotherapy vault room was modeled with a W-made spherical shell in whose center was located the source term of photoneutrons produced by a Linac head operating in Bremsstrahlung mode at 18 MV. In the calculations a phantom made of tissue equivalent was modeled while a beam of photoneutrons was applied on the phantom prostatic region using a field of 10 x 10 cm{sup 2}. During simulation neutrons were isotropically transported from the Linac head to the phantom chest, here a 1 {theta} x 1 cm{sup 2} cylinder made of polystyrene was modeled as the CMOS, where the neutron spectrum and the absorbed dose were estimated. Main damages to CMOS are by protons produced during neutron collisions protective cover made of H-rich materials, here the neutron spectrum that reach the CMOS was calculated showing a small peak around 0.1 MeV and a larger peak in the thermal region, both connected through epithermal neutrons. (Author)

  1. Radiation absorbed dose from medically administered radiopharmaceuticals

    International Nuclear Information System (INIS)

    Roedler, H.D.; Kaul, A.

    1975-01-01

    The use of radiopharmaceuticals for medical examinations is increasing. Surveys carried out in West Berlin show a 20% average yearly increase in such examinations. This implies an increased genetic and somatic radiation exposure of the population in general. Determination of radiation exposure of the population as well as of individual patients examined requires a knowledge of the radiation dose absorbed by each organ affected by each examination. An extensive survey of the literature revealed that different authors reported widely different dose values for the same defined examination methods and radiopharmaceuticals. The reason for this can be found in the uncertainty of the available biokinetic data for dose calculations and in the application of various mathematical models to describe the kinetics and calculation of organ doses. Therefore, the authors recalculated some of the dose values published for radiopharmaceuticals used in patients by applying biokinetic data obtained from exponential models of usable metabolism data reported in the literature. The calculation of organ dose values was done according to the concept of absorbed fractions in its extended form. For all radiopharmaceuticals used in nuclear medicine the energy dose values for the most important organs (ovaries, testicles, liver, lungs, spleen, kidneys, skeleton, total body or residual body) were recalculated and tabulated for the gonads, skeleton and critical or examined organs respectively. These dose values are compared with those reported in the literature and the reasons for the observed deviations are discussed. On the basis of recalculated dose values for the gonads and bone-marrow as well as on the basis of results of statistical surveys in West Berlin, the genetically significant dose and the somatically (leukemia) significant dose were calculated for 1970 and estimated for 1975. For 1970 the GSD was 0.2 mrad and the LSD was 0.7 mrad. For 1975 the GSD is estimated at < 0.5 mrad and the

  2. Burnable absorber for the PIK reactor

    International Nuclear Information System (INIS)

    Gostev, V.V.; Smolskii, S.L.; Tchmshkyan, D.V.; Zakharov, A.S.; Zvezdkin, V.S.; Konoplev, K.A.

    1998-01-01

    In the reactor PIK design a burnable absorber is not used and the cycle duration is limited by the rods weight. Designed cycle time is two weeks and seams to be not enough for the 100 MW power research reactor equipped by many neutron beams and experimental facilities. Relatively frequent reloading reduces the reactor time on full power and in this way increases the maintenance expenses. In the reactor core fuel elements well mastered by practice are used and its modification was not approved. We try to find the possibilities of installation in the core separate burnable elements to avoid poison of the fuel. It is possible to replace a part of the fuel elements by absorbers, since the fuel elements are relatively small (diameter 5.15mm, uranium 235 content 7.14g) and there are more then 3800 elements in the core. Nevertheless, replacing decreases the fuel burnup and its consumption. In the PIK fuel assembles a little part of the volume is occupied by the dumb elements to create a complete package of the assembles shroud, that is necessary in the hydraulic reasons. In the presented report the assessment of such a replacement is done. As a burnable material Gadolinium was selected. The measurements or the beginning of cycle were performed on the critical facility PIK. The burning calculation was confirmed by measurements on the 18MW reactor WWR-M. The results give the opportunity to twice the cycle duration. The proposed modification of the fuel assembles does not lead to alteration in the other reactor systems, but it touch the burned fuel reprocessing technology. (author)

  3. 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.

  4. Microwave Absorbent Packaging Material from Composites Chitosan-Polyvinyl Alcohol Polymer

    Directory of Open Access Journals (Sweden)

    Bambang - Riyanto

    2014-11-01

    Full Text Available Microwave absorbent packaging materials currently tend to biomaterial. Chitosan is a dielectric biomaterial with polycationic properties. The aim of this study was to analyze characteristics of microwave absorbing packaging material made from composite chitosan-polyvinyl alcohol (PVA polymer. The ability of the packaging material to absorb microwave was determined by reflection loss measurement. Formed packaging prototype resembles as a thin transparent yellowish plastic with thickness (0.11-0.22 mm and the tensile strength (106.33±2.82-143.00±2.59 kPa. SEM analysis showed homogenous structure characterized by interaction between chitosan and PVA. Optimum absorption value was obtained from chitosan concentration of 1%, with average value of reflection loss was (-31.9289±4.0094 dB.Keywords: chitosan, material packaging, microwave, reflection loss

  5. Microwave Absorbent Packaging Material from Composites Chitosan-Polyvinyl Alcohol Polymer

    Directory of Open Access Journals (Sweden)

    Bambang - Riyanto

    2015-07-01

    Full Text Available Microwave absorbent packaging materials currently tend to biomaterial. Chitosan is a dielectric biomaterial with polycationic properties. The aim of this study was to analyze characteristics of microwave absorbing packaging material made from composite chitosan-polyvinyl alcohol (PVA polymer. The ability of the packaging material to absorb microwave was determined by reflection loss measurement. Formed packaging prototype resembles as a thin transparent yellowish plastic with thickness (0.11-0.22 mm and the tensile strength (106.33±2.82-143.00±2.59 kPa. SEM analysis showed homogenous structure characterized by interaction between chitosan and PVA. Optimum absorption value was obtained from chitosan concentration of 1%, with average value of reflection loss was (-31.9289±4.0094 dB.Keywords: chitosan, material packaging, microwave, reflection loss

  6. A black body absorber from vertically aligned single-walled carbon nanotubes

    Science.gov (United States)

    Mizuno, Kohei; Ishii, Juntaro; Kishida, Hideo; Hayamizu, Yuhei; Yasuda, Satoshi; Futaba, Don N.; Yumura, Motoo; Hata, Kenji

    2009-01-01

    Among all known materials, we found that a forest of vertically aligned single-walled carbon nanotubes behaves most similarly to a black body, a theoretical material that absorbs all incident light. A requirement for an object to behave as a black body is to perfectly absorb light of all wavelengths. This important feature has not been observed for real materials because materials intrinsically have specific absorption bands because of their structure and composition. We found a material that can absorb light almost perfectly across a very wide spectral range (0.2–200 μm). We attribute this black body behavior to stem from the sparseness and imperfect alignment of the vertical single-walled carbon nanotubes. PMID:19339498

  7. Endangered Animals. Second Grade.

    Science.gov (United States)

    Popp, Marcia

    This second grade teaching unit centers on endangered animal species around the world. Questions addressed are: What is an endangered species? Why do animals become extinct? How do I feel about the problem? and What can I do? Students study the definition of endangered species and investigate whether it is a natural process. They explore topics…

  8. Calculating Student Grades.

    Science.gov (United States)

    Allswang, John M.

    1986-01-01

    This article provides two short microcomputer gradebook programs. The programs, written in BASIC for the IBM-PC and Apple II, provide statistical information about class performance and calculate grades either on a normal distribution or based on teacher-defined break points. (JDH)

  9. Grades as Information

    Science.gov (United States)

    Grant, Darren

    2007-01-01

    We determine how much observed student performance in microeconomics principles can be attributed, inferentially, to three kinds of student academic "productivity," the instructor, demographics, and unmeasurables. The empirical approach utilizes an ordered probit model that relates student performance in micro to grades in prior…

  10. First Grade Baseline Evaluation

    Science.gov (United States)

    Center for Innovation in Assessment (NJ1), 2013

    2013-01-01

    The First Grade Baseline Evaluation is an optional tool that can be used at the beginning of the school year to help teachers get to know the reading and language skills of each student. The evaluation is composed of seven screenings. Teachers may use the entire evaluation or choose to use those individual screenings that they find most beneficial…

  11. The Fifth Grade Classroom.

    Science.gov (United States)

    Hartman, Michael; And Others

    An interdisciplinary design project report investigates the relationship of the fifth grade educational facility to the student and teacher needs in light of human and environmental factors. The classroom, activity and teaching spaces are analyzed with regard to the educational curriculum. Specifications and design criteria concerning equipment…

  12. Cutting Class Harms Grades

    Science.gov (United States)

    Taylor, Lewis A., III

    2012-01-01

    An accessible business school population of undergraduate students was investigated in three independent, but related studies to determine effects on grades due to cutting class and failing to take advantage of optional reviews and study quizzes. It was hypothesized that cutting classes harms exam scores, attending preexam reviews helps exam…

  13. Crush Can Behaviour as an Energy Absorber in a Frontal Impact

    International Nuclear Information System (INIS)

    Bhuyan, Atanu; Ganilova, Olga

    2012-01-01

    The work presented is devoted to the investigation of a state-of-the-art technological solution for the design of a crush-can characterized by optimal energy absorbing properties. The work is focused on the theoretical background of the square tubes, circular tubes and inverbucktube performance under impact with the purpose of design of a novel optimized structure. The main system under consideration is based on the patent US 2008/0185851 A1 and includes a base flange with elongated crush boxes and back straps for stabilization of the crush boxes with the purpose of improvement of the energy-absorbing functionality. The modelling of this system is carried out applying both a theoretical approach and finite element analysis concentrating on the energy absorbing abilities of the crumple zones. The optimization process is validated under dynamic and quasi-static loading conditions whilst considering various modes of deformation and stress distribution along the tubular components. Energy absorbing behaviour of the crush-cans is studied concentrating on their geometrical properties and their diamond or concertina modes of deformation. Moreover, structures made of different materials, steel, aluminium and polymer composites are considered for the material effect analysis and optimization through their combination. Optimization of the crush-can behaviour is done within the limits of the frontal impact scenario with the purpose of improvement of the structural performance in the Euro NCAP tests.

  14. Crush Can Behaviour as an Energy Absorber in a Frontal Impact

    Science.gov (United States)

    Bhuyan, Atanu; Ganilova, Olga

    2012-08-01

    The work presented is devoted to the investigation of a state-of-the-art technological solution for the design of a crush-can characterized by optimal energy absorbing properties. The work is focused on the theoretical background of the square tubes, circular tubes and inverbucktube performance under impact with the purpose of design of a novel optimized structure. The main system under consideration is based on the patent US 2008/0185851 A1 and includes a base flange with elongated crush boxes and back straps for stabilization of the crush boxes with the purpose of improvement of the energy-absorbing functionality. The modelling of this system is carried out applying both a theoretical approach and finite element analysis concentrating on the energy absorbing abilities of the crumple zones. The optimization process is validated under dynamic and quasi-static loading conditions whilst considering various modes of deformation and stress distribution along the tubular components. Energy absorbing behaviour of the crush-cans is studied concentrating on their geometrical properties and their diamond or concertina modes of deformation. Moreover, structures made of different materials, steel, aluminium and polymer composites are considered for the material effect analysis and optimization through their combination. Optimization of the crush-can behaviour is done within the limits of the frontal impact scenario with the purpose of improvement of the structural performance in the Euro NCAP tests.

  15. Independent polarization and multi-band THz absorber base on Jerusalem cross

    Science.gov (United States)

    Arezoomand, Afsaneh Saee; Zarrabi, Ferdows B.; Heydari, Samaneh; Gandji, Navid P.

    2015-10-01

    In this paper, we present the design and simulation of a single and multi-band perfect metamaterial absorber (MA) in the THz region base on Jerusalem cross (JC) and metamaterial load in unit cells. The structures consist of dual metallic layers for allowing near-perfect absorption with absorption peak of more than 99%. In this novel design, four-different shape of Jerusalem cross is presented and by adding L, U and W shape loaded to first structure, we tried to achieve a dual-band absorber. In addition, by good implementation of these loaded, we are able to control the absorption resonance at second resonance at 0.9, 0.7 and 0.85 THz respectively. In the other hand, we achieved a semi stable designing at first resonance between 0.53 and 0.58 THz. The proposed absorber has broadband polarization angle. The surface current modeled and proved the broadband polarization angle at prototype MA. The LC resonance of the metamaterial for Jerusalem cross and modified structures are extracting from equivalent circuit. As a result, proposed MA is useful for THz medical imaging and communication systems and the dual-band absorber has applications in many scientific and technological areas.

  16. A mechanical analysis of woodpecker drumming and its application to shock-absorbing systems

    International Nuclear Information System (INIS)

    Yoon, Sang-Hee; Park, Sungmin

    2011-01-01

    A woodpecker is known to drum the hard woody surface of a tree at a rate of 18 to 22 times per second with a deceleration of 1200 g, yet with no sign of blackout or brain damage. As a model in nature, a woodpecker is studied to find clues to develop a shock-absorbing system for micromachined devices. Its advanced shock-absorbing mechanism, which cannot be explained merely by allometric scaling, is analyzed in terms of endoskeletal structures. In this analysis, the head structures (beak, hyoid, spongy bone, and skull bone with cerebrospinal fluid) of the golden-fronted woodpecker, Melanerpes aurifrons, are explored with x-ray computed tomography images, and their shock-absorbing mechanism is analyzed with a mechanical vibration model and an empirical method. Based on these analyses, a new shock-absorbing system is designed to protect commercial micromachined devices from unwanted high-g and high-frequency mechanical excitations. The new shock-absorbing system consists of close-packed microglasses within two metal enclosures and a viscoelastic layer fastened by steel bolts, which are biologically inspired from a spongy bone contained within a skull bone encompassed with the hyoid of a woodpecker. In the experimental characterizations using a 60 mm smoothbore air-gun, this bio-inspired shock-absorbing system shows a failure rate of 0.7% for the commercial micromachined devices at 60 000 g, whereas a conventional hard-resin method yields a failure rate of 26.4%, thus verifying remarkable improvement in the g-force tolerance of the commercial micromachined devices.

  17. Inkjet Printing and Ebeam Sintering Approach to Fabrication of GHz Meta material Absorber

    International Nuclear Information System (INIS)

    Park, J. W.; Kim, Y. J.; Lee, Y. P.; Park, I. S.; Kang, J. H.; Lim, Jongwoo; Kim, Jonghee; Kim, Hyotae

    2013-01-01

    Metamaterial absorber structure of GHz range is fabricated by inkjet printing and e-beam sintering. The inkjet printing is of interest, which give the easier and quicker way to fabricate large scale metamaterials than the approaches by the lithographic process, Furthermore it is more suitable to make flexible electronics, which has yet been great technologic trend. Usual post process of inkjet printing is the sintering to ensure solvent-free from the printed pattern and to its better conductivity comparable to the ordinary vacuum deposition process. E-beam irradiation sintering of the pattern is promising because it is inherently local and low temperature process. The main procedure of metamaterials fabrication is printing a resonator structure with lossy metal such as Ag or Au. We designed two types of Ag based multiband absorber which are double and quadruple bands. Those adsorber patterns are printed on polyimide substrate with commercially available Ag ink (DGP 40LT-15C, 25C). The absorbance performance of fabricated metamaterials is characterized by Hewlett-Packard E836B network analyzer in microwave anechoic chamber. The conductivity enhancement after e-beam or other sintering process is checked by measuring sheet resistance. The absorbance of the fabricated metamaterial is measured around 60% for the types designed. The absorbance is not high enough to practical use, which is attributed to low conductivity of the printed pattern. The spectrum shows, however, quite interesting large broadness, which come in the interval between each pack absorbance, witch needs further study. Though the extent of its effectiveness of inkjet printing in metamaterials needs more experimental studies, the demonstrated capability of quick and large area fabrication to flexible substrate is excellent

  18. Extinction by a Homogeneous Spherical Particle in an Absorbing Medium

    Science.gov (United States)

    Mishchenko, Michael I.; Videen, Gorden; Yang, Ping

    2017-01-01

    We use a recent computer implementation of the first principles theory of electromagnetic scattering to compute far-field extinction by a spherical particle embedded in an absorbing unbounded host. Our results show that the suppressing effect of increasing absorption inside the host medium on the ripple structure of the extinction efficiency factor as a function of the size parameter is similar to the well-known effect of increasing absorption inside a particle embedded in a nonabsorbing host. However, the accompanying effects on the interference structure of the extinction efficiency curves are diametrically opposite. As a result, sufficiently large absorption inside the host medium can cause negative particulate extinction. We offer a simple physical explanation of the phenomenon of negative extinction consistent with the interpretation of the interference structure as being the result of interference of the field transmitted by the particle and the diffracted field due to an incomplete wave front resulting from the blockage of the incident plane wave by the particle's geometrical projection.

  19. Thermoelectric System Absorbing Waste Heat from a Steel Ladle

    Science.gov (United States)

    Lu, Baiyi; Meng, Xiangning; Zhu, Miaoyong; Suzuki, Ryosuke O.

    2018-06-01

    China's iron and steel industry has made great progress in energy savings and emission reductions with the application of many waste heat recovery technologies. However, most of the medium and low temperature waste heat and radiant waste heat has not been effectively utilized. This paper proposes a thermoelectric system that generates electricity by absorbing the radiant heat from the surface of steel ladles in a steel plant. The thermoelectric behavior of modules in this system is analyzed by a numerical simulation method. The effects of external resistance and module structure on thermoelectric performance are also discussed in the temperature range of the wall surface of a steel ladle. The results show that the wall temperature has a significant influence on the thermoelectric behavior of the module, so its uniformity and stability should be considered in practical application. The ratio of the optimum external resistance to the internal resistance of the thermoelectric module is in the range of 1.6-2.0, which indicates the importance of external load optimization for a given thermoelectric system. In addition, the output power and the conversion efficiency of the module can be significantly improved by increasing the length of the thermoelectric legs and adopting a double-layer structure. Finally, through the optimization of external resistance and structure, the power output can reach 83-304 W/m2. This system is shown to be a promising approach for energy recovery.

  20. Preparation and characterization of super absorbent polymer from sugarcane bagasse

    International Nuclear Information System (INIS)

    Wiwien Andriyanti; Suyanti; Ngasifudin

    2012-01-01

    Sugarcane bagasse is a source of biomass which large enough numbers and has not been fully exploited. At this time has developed a super absorbent polymer material of sugarcane bagasse that can absorb water up to several times of its own weight and keep this water. Super absorbent polymers can be used as a soil conditioner that can be used as an absorber and storage of ground water, the giver of nutrients for plants, and can improve soil properties. The purpose of this study is to make and characterization of super absorbent polymer (PCS) from sugarcane bagasse. Preparation of super absorbent polymers (PCS) has been done by grafting method using ionizing radiation from Electron Beam Engineering (MBE) 350 mA keV/10. Irradiation process carried out with a dose variation of 20, 35, and 50 kGy. Increasing doses of radiation will increase the percentage fraction of transplantation (grafting) and the fraction of water absorption ability (swelling ratio). (author)