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Sample records for very-low-temperature crystallization peak

  1. REFRIGERATION ESPECIALLY FOR VERY LOW TEMPERATURES

    Science.gov (United States)

    Kennedy, P.B.; Smith, H.R. Jr.

    1960-09-13

    A refrigeration system for producing very low temperatures is described. The system of the invention employs a binary mixture refrigerant in a closed constant volume, e.g., Freon and ethylene. Such mixture is compressed in the gaseous state and is then separated in a fractionating column element of the system. Thenceforth, the first liquid to separate is employed stagewise to cool and liq uefy successive portions of the refrigerant at successively lower temperatures by means of heat exchangers coupled between the successive stages. When shut down, all of the volumes of the system are interconnected and a portion of the refrigerant remains liquid at ambient temperatures so that no dangerous overpressures develop. The system is therefore rugged, simple and dependable in operation.

  2. Properties of concrete at very low temperatures : A survey of the literature

    NARCIS (Netherlands)

    Van de Veen, V.

    1987-01-01

    This literature survey is focussed on the behaviour of concrete at very low temperatures down to -196°C. To give the reader some theoretical background, first the mechanisms of freezing and frost damage are discussed. Based on these mechanisms, reasonable explanations can be given for the

  3. RESISTIVITY OF TmSe UNDER PRESSURE AT VERY LOW TEMPERATURE

    OpenAIRE

    Flouquet, J.; Haen, P.; HOLTZBERG, F; Lapierre, F.; Mignot, Jean; Ribault, M.; Tournier, R.

    1980-01-01

    Resistivity measurements of a nearly stoichiometric sample up to 6 kbar and down to 25 mK are reported. For 6 kbar, the resistivity ρ rises up to 120 mΩ.cm at 30 mK whereas just above the ordering temperature TN at 4.2 K its value is 1.65 mΩ.cm. The increase of ρ is exponential with the pressure at very low temperature and linear in the vicinity of TN. Comparisons are made with the pressure dependence of the sublattice magnetization measured by neutron diffraction and with resistivity of othe...

  4. X-ray micro-CT measurement of large parts at very low temperature

    Science.gov (United States)

    Koutecký, T.; Zikmund, T.; Glittová, D.; Paloušek, D.; Živčák, J.; Kaiser, J.

    2017-03-01

    At present, the automotive industry, along with other industries, has increasing demands on accuracy of produced parts and assemblies. Besides the regular dimensional and geometrical inspection, in some cases, also a verification at very low temperatures is required. X-ray computed tomography (CT), as a tool for non-destructive testing, is able to examine samples and then determine dimensions for strictly stable temperature conditions necessary for the stability of the CT system. Until now, no system that allows scanning of samples larger than a few millimeters at temperatures much below 0 °C has been presented. This paper presents a cooling system for CT imaging of parts with length up to 300 mm at the extreme temperature conditions of -40 °C, which are based on automotive industry requests. It describes the equipment and conditions under which it is possible to achieve a temperature stability of samples at low temperatures, while keeping an independent temperature regulation of the CT system. The presented system uses a standard industrial CT device and a newly designed cooling stage with passive cooling based on phase-change material. The system is demonstrated on the measurement of plastic part (car door handle) at temperatures of -40 °C and 20 °C. The paper also presents the method of how to interpret the thermal changes using tools of the commercial software VGStudio MAX (Volume Graphics GmbH, Germany).

  5. Neutron moderation at very low temperatures (1691); Moderation des neutrons aux tres basses temperatures (1961)

    Energy Technology Data Exchange (ETDEWEB)

    Lacaze, A. [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1961-04-15

    Starting from Harwell experiment carried out inside a low-power reactor, we intended to maintain a liquid hydrogen cell in a channel of the EL3 reactor (at Saclay) whose thermal neutrons flux is 10{sup 14} neutrons/cm{sup 2}/s. We tried to work out a device giving off an important beam of cold neutrons and able to operate in a way as automatic as possible during many consecutive day without a stop. Several circuits have already been achieved at very low temperatures but they brought out volumes and fluxes much lower than those we used this time. The difficulties we have met in carrying out such a device arose on the one hand from the very high energy release to which any kind of experiment is inevitably submitted when placed near the core of the reactor, on the other, hand from the very little room which is available in experimental channels of reactors. In such condition, it is necessary to use a moderator as effective as possible. This study is divided into three parts ; in the first part, we try to determine: a) conditions in which moderation takes place, hence the volume of the cell; b) materials likely to be used at low temperature and in pile; c) cooling system; hence we had to study fluid flow conditions at very low temperatures in very long ducts. The second part is devoted to the description of the device. The third part ventilates the results we have obtained. (author) [French] Partant de l'experience de Harwell faite dans une pile de faible puissance, nous nous sommes propose de maintenir une cellule d'hydrogene liquide dans un canal de la pile EL3 de Saclay dont le flux de neutrons thermiques est de 10{sup 14} neutrons par seconde et par cm{sup 2}. Nous avons cherche a realiser une installation donnant un faisceau de neutrons froids important, et pouvant fonctionner d'une maniere aussi automatique que possible, pendant des periodes de plusieurs jours sans arret. Plusieurs circuits aux tres basses temperatures ont deja ete realises, mais

  6. Controlling factors of tunneling reactions in solid hydrogen at very low temperature

    Energy Technology Data Exchange (ETDEWEB)

    Miyazaki, Tetsuo E-mail: miyamiya@apchem.nagoya-u.ac.jp; Kumagai, Jun; Kumada, Takayuki

    2001-07-01

    The recent studies on tunneling reactions of our group are auto-reviewed. The local structure around reactants, the new temperature effect, and the impurity effect are pointed out as important controlling factors of tunneling reactions in the solid phase. The distances between H(D) atoms and H{sub 2}(HD, D{sub 2}) molecules in solid hydrogen and solid argon were estimated by ESR, electron nuclear double resonance (ENDOR), and electron spin echo (ESE). The new temperature effects on tunneling reaction were observed in a reaction D+HD{yields}D{sub 2}+H in solid HD. A mechanism of a vacancy-assisted tunneling reaction has been proposed to account for the temperature effect. The strange temperature dependence of a tunneling electron-transfer-reaction H{sub 2}{sup -}+H{sub 2}{yields}H{sub 2}+H{sub 2}{sup -} was explained in terms of the phonon-scattering effect and the impurity effect on the tunneling reaction. The rate constant for a tunneling reaction H+p-H{sub 2}{yields}p-H{sub 2}+H in solid para-H{sub 2} (p-H{sub 2}) decreases with the increase in the concentration of ortho-H{sub 2} (o-H{sub 2}). The results were explained by the model that the orientational defects by o-H{sub 2} molecules affect the tunneling reaction H+p-H{sub 2}. A tunneling reaction at very low temperature gives a surprising example in control of a reaction that a small amount of energy as such 2 cal mol{sup -1} can affect the rate of a reaction. The tunneling reaction in the solid phase, which can be considered as a multidimensional tunneling phenomenon, is affected significantly by the condition surrounding reactants. (author)

  7. Very low temperature OSL-thermochronometry applied to the Siwalik deposits in Nepal and Bhutan

    Science.gov (United States)

    King, G. E.; Grujic, D.; Coutand, I.; Herman, F.

    2016-12-01

    The Himalayan foreland fold-and-thrust belt is made of Neogene synorogenic sediments of the Siwalik Group and accommodates a large fraction of the India-Eurasia convergence. This region receives high precipitation and experiences seismic events of M8 and larger. Along the strike of the 2500-km-long orogenic arc, the eastward narrowing of the fold-and-thrust belt has been attributed to increasing annual rainfall and specific stream power, rather than to lateral changes in shortening rates. However, exhumation/erosion rates of this unit remain unknown. Precisely constraining the erosion rates of this unit at the scale of the orogen would allow an estimate of the relative contributions of tectonic and climatic processes to the erosion of the youngest and frontal part of the Himalayan orogen. Thermochronometry enables the cooling, and therefore exhumation/erosion histories of rocks to be determined. However the exhumation histories of the Siwalik Group, which have experienced limited burial heating not exceeding 100-50 °C remain very difficult to constrain using traditional thermochronometers. Optically stimulated luminescence (OSL)-thermochronometry is a recently developed very low temperature thermochronometer sensitive to temperatures of 30-90 °C. Consequently, its application to the Siwalik deposits may provide insights into their cooling and exhumation histories. K-feldspar extracts from 18 sandstones samples of the Siwalik Group were investigated using a multi-OSL-thermochronometry approach, whereby four different signals, with different thermal stabilities were measured for each sample. The sandstone samples were collected along two traverses across the Himalayan fold-and-thrust belt in western Nepal, and eastern Bhutan. Using signals with different thermal sensitivities enables high precision Quaternary cooling histories to be derived. These data were inverted using a Bayesian approach resulting in preliminary cooling rates of 100 °C/Myr during the last 0

  8. Laser-induced breakdown spectroscopy on metallic samples at very low temperature in different ambient gas pressures

    Science.gov (United States)

    El-Saeid, R. H.; Abdelhamid, M.; Harith, M. A.

    2016-02-01

    Analysis of metals at very low temperature adopting laser-induced breakdown spectroscopy (LIBS) is greatly beneficial in space exploration expeditions and in some important industrial applications. In the present work, the effect of very low sample temperature on the spectral emission intensity of laser-induced plasma under both atmospheric pressure and vacuum has been studied for different bronze alloy samples. The sample was cooled down to liquid nitrogen (LN) temperature 77 K in a special vacuum chamber. Laser-induced plasma has been produced onto the sample surface using the fundamental wavelength of Nd:YAG laser. The optical emission from the plasma is collected by an optical fiber and analyzed by an echelle spectrometer combined with an intensified CCD camera. The integrated intensities of certain spectral emission lines of Cu, Pb, Sn, and Zn have been estimated from the obtained LIBS spectra and compared with that measured at room temperature. The laser-induced plasma parameters (electron number density Ne and electron temperature Te) were investigated at room and liquid nitrogen temperatures for both atmospheric pressure and vacuum ambient conditions. The results suggest that reducing the sample temperature leads to decrease in the emission line intensities under both environments. Plasma parameters were found to decrease at atmospheric pressure but increased under vacuum conditions.

  9. Ionization measurement at very low temperature for nuclear and electron recoils discrimination by ionization-heat simultaneous measurement for dark matter research

    CERN Document Server

    Navick, X F; Tourbot, R

    2000-01-01

    To achieve a high level of discrimination between nuclear recoils and electron recoils for dark matter research, we realized and studied ionization-heat detectors working at very low temperature (10-20 mK). To understand the mechanisms underlying the ionization measurement at this temperature range, we made systematic studies of detectors performances (time stability, energy resolution, etc.) in X- and gamma-rays detection for Ge and Si detectors. Results are presented and discussed. We found that the time stability is governed by the progressive space charge build-up due to impurities ionization by far-infrared radiation. Moreover if the energy resolution of HPGe-pin detectors is limited by the noise, it appears to be intrinsically limited by carrier trapping on neutral impurities in Si detectors.

  10. ZnS thin films grown by atomic layer deposition on GaAs and HgCdTe substrates at very low temperature

    Science.gov (United States)

    Sun, C. H.; Zhang, P.; Zhang, T. N.; Chen, X.; Chen, Y. Y.; Ye, Z. H.

    2017-09-01

    ZnS films grown on GaAs and HgCdTe substrates by atomic layer deposition (ALD) under very low temperature were investigated in this work. ZnS films were grown under several temperatures lower than 140 °C. The properties of the films were investigated with high-resolution X-ray diffraction (HRXRD), scanning electron microscope (SEM), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). The results showed the ZnS films were polycrystalline. The growth rate monotonically decreased with temperature, as well as the root mean square (r.m.s) roughness measured by AFM. XPS measurement revealed the films were stoichiometric in Zn and S.

  11. Peak/total-ratios for NaI(Tl)-crystals

    NARCIS (Netherlands)

    Leutz, H.; Schulz, G.; Gelderen, L. van

    The fraction of γ-quanta totally absorbed in NaI(Tl)-crytals was determined for eight scintillation assemblies having dimensions from 1″ dia.× 1″ hgt through 8″ dia.× 8″ hgt. The γ-energies varied from 122 keV to 2.62 MeV and the γ-sources were placed at distances of 10 cm and 50 cm from crystal

  12. Structural Evolution of Colloidal Crystal Films in the Process of Melting Revealed by Bragg Peak Analysis

    NARCIS (Netherlands)

    Sulyanova, Elena A.; Shabalin, Anatoly; Zozulya, Alexey V.; Meijer, Janne-Mieke|info:eu-repo/dai/nl/325780277; Dzhigaev, Dmitry; Gorobtsov, Oleg; Kurta, Ruslan P.; Lazarev, Sergey; Lorenz, Ulf; Singer, Andrej; Yefanov, Oleksandr; Zaluzhnyy, Ivan; Besedin, Ilya; Sprung, Michael; Petukhov, A. V.|info:eu-repo/dai/nl/304829196; Vartanyants, Ivan A.

    2015-01-01

    In situ X-ray diffraction studies of structural evolution of colloidal crystal films formed by polystyrene spherical particles upon incremental heating are reported. The Bragg peak parameters, such as peak position, integrated intensity, and radial and azimuthal widths were analyzed as a function of

  13. Dosimetric properties of the 570 K thermoluminescence peak of YAlO{sub 3}:Mn crystals

    Energy Technology Data Exchange (ETDEWEB)

    Zhydachevskii, Ya., E-mail: crystal@polynet.lviv.u [Lviv Polytechnic National University, 12 Bandera, Lviv 79646 (Ukraine); Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, Warsaw 02-668 (Poland); Berkowski, M. [Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, Warsaw 02-668 (Poland); Warchol, S. [Institute of Nuclear Chemistry and Technology, Dorodna 16, Warsaw 03-195 (Poland); Suchocki, A. [Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, Warsaw 02-668 (Poland); Institute of Physics, University of Bydgoszcz, Weyssenhoffa 11, Bydgoszcz 85-072 (Poland)

    2011-05-15

    We report results of the experimental study of thermoluminescent properties of the high-temperature TL peak at 570 K observed in YAlO{sub 3}:Mn,Si crystals at low concentrations of manganese ions. The potential of this TL peak for thermoluminescent dosimetry of ionizing radiation is discussed. Main dosimetric properties of the TL peak including dose dependence, thermal fading and the effect of visible light exposure were studied.

  14. Germanium crystal dimensions and their influences on the observed peak-to-background distributions

    Energy Technology Data Exchange (ETDEWEB)

    Wahl, W. [GSF-Forschungszentrum fuer Umwelt und Gesundheit, Inst. fuer Strahlenschutz, AG-Personendosimetrie, Oberschleissheim (Germany); Koenig, K. [Bundesamt fuer Strahlenschutz, Oberschleissheim (Germany). Inst. fuer Strahlenhygiene

    1997-03-01

    This description applies to the parameters of in vivo and in vitro detection systems as they relate to the type of the detector (or arrangements of detectors) and the performance of the choice. In detail, measurements of a set of pulse-height distributions were done to determine the influence from the detector-crystal dimensions on the peak-to-background variation for point and volume sources as well as ambient radiation. The current capability in suppression of Compton scattered {gamma}-rays using coincidence/anti-coincidence arrangements both for in vivo and in vitro system are presented. Criteria and relations as well as advantages and disadvantages of the applicability are discussed. (orig.)

  15. Peak effect and magnetization minima in Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+y} single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Pradhan, A.K.; Roy, S.B.; Chaddah, P. [Low Temperature Physics Group, Centre for Advanced Technology, Indore 452013 (India); Kanjilal, D. [Nuclear Science Centre, Aruna Asaf Aali Marg, Post Box 10502, New Delhi 110067 (India); Chen, C.; Wanklyn, B.M. [Clarendon Laboratory, Physics Department, Oxford University, Parks Road, Oxford OX1 3PU (United Kingdom)

    1996-09-01

    We report the effects of annealing at 400 deg. C in oxygen and also in argon on the double-peak magnetization anomaly in as-grown BSCCO crystal. The diffusion or injection of oxygen does not change the peak structure. Argon annealing produces an increase in the pinning and the irreversibility field. The double-peak anomaly in BSCCO crystal that disappears after heavy-ion irradiation cannot be reconstructed on oxygen annealing. The effects of annealing on the irradiated crystal have been studied in detail. The origin of the magnetization minimum observed in the field-cooled magnetization is not clear and cannot be explained using the existing models. (author)

  16. A study by internal friction of defects produced in iron and nickel irradiated at very low temperatures; Etude au moyen du frottement interne des defauts crees par irradiation a tres basse temperature dans le fer et le nickel

    Energy Technology Data Exchange (ETDEWEB)

    Keating-Hart, G. de [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1969-07-01

    This work represents a contribution to the study of point defects in metals. After a brief review of the theory of internal friction we will discuss some technical innovations aimed at increasing the flexibility of the apparatus at our disposal. These innovations have allowed us to extend our range of measurements down to 20 deg. K. We will then discuss our experimental results. Firstly, we describe preliminary experiments on electron irradiated iron and the evidence for a laminar structure. Secondly, we present and account of the first measurements on nickel after neutron irradiation at 27 deg. K. We will compare the results with those obtained by other methods in this laboratory. Essentially we have observed transitory peaks at low temperature due to close Frenkel pairs and we have noticed the absence of a peak which would correspond to the magnetic after effect band of stage I{sub E}. An attempt is made to explain the disappearance of the observed peaks upon the application of an internal saturating magnetic field. (author) [French] Ce memoire constitue une contribution a l'etude des defauts ponctuels dans les metaux. Apres un bref apercu theorique sur le frottement interne, nous presenterons quelques realisations techniques destinees a accroitre les possibilites des instruments qui nous ont ete confies. Ces dernieres nous ont permis d'etendre la gamme des mesures jusqu'a 20 deg. K. Nous parlerons ensuite de nos resultats experimentaux. En premier lieu, ceux obtenus au cours de premieres experiences, sur le fer irradie aux electrons mettent en evidence des structures de laminage. En second lieu, nous exposerons les premieres mesures realisees sur du nickel irradie aux neutrons; nous comparerons ces resultats avec ceux obtenus par d'autres moyens experimentaux dans le laboratoire. Nous avons observe essentiellement des pics fugitifs a basse temperature dus aux paires proches de Frenckel et nous avons constate l'absence d'un pic

  17. New insights into the origin of ladder dikes: Implications for punctuated growth and crystal accumulation in the Cathedral Peak granodiorite

    Science.gov (United States)

    Wiebe, R. A.; Jellinek, A. M.; Hodge, K. F.

    2017-04-01

    Ladder dikes are steep tabular bodies, typically a meter or less thick, composed of moderately dipping, concave upward, alternating dark (i.e. schlieren) and light bands oriented roughly perpendicular to the ladder dike margins. These structures occur widely but sparsely in granitic rocks and are found prominently in the Cathedral Peak granodiorite (CPG) of the Tuolumne Intrusive suite. Previous studies have interpreted that ladder dikes form as a result of processes including the downward flow of crystal mush in cracks within strong crystal mush or by upward flow in steep tubes that migrate within a strong crystal mush. Our new observations indicate that ladder dikes formed by downward flow of crystal mush in troughs or valleys, in a manner potentially comparable to trough bands in mafic layered intrusions. Extensions of the schlieren outward and upward away from the ladder dike margins into the host granite demonstrate that the host granite was deposited as mounds on both sides at the same time as the ladder dikes. Ladder dikes, therefore, record lateral flows of crystal mush on a magma chamber floor. Vertical exposures suggest these flows are on the order of ten meters thick. Some steep exposures on granite domes indicate multiple ladder dikes (and flows) over a stratigraphic height of 80-100 m. Later (stratigraphically higher) flows commonly deform and erode the top of an earlier flow, and granitic material rich in K-feldspar megacrysts has locally engulfed large blocks of ladder dikes, demonstrating that the megacrysts were also transported in flows. Flows in the CPG are directed away from the center of the pluton toward the western and eastern margins and apparently spread along a strong crystal mush floor and into a rheologically complex CPG magma. Whereas established dynamical models for spreading (single phase) gravity currents with simple and complex rheologies explain the elongate geometry, spacing and orientation of the tabular bodies, the origin and

  18. Extraction of mean free path of charge carriers in CdZnTe crystals from measured full-energy peaks

    CERN Document Server

    Miyajima, S; Matsumoto, M

    2002-01-01

    The mean free path of electrons (lambda sub e) and holes (lambda sub h) in a CdZnTe crystal were extracted from measured gamma-ray spectra. First, distortion due to Gaussian broadening was unfolded from full-energy peaks in the gamma-ray spectra. As a result, only tailing was left in the unfolded peaks. Second, lambda sub e and lambda sub h were determined by fitting tailing of full-energy peaks in calculated response functions to that in the unfolded gamma-ray spectra. The response functions were calculated using EGS4 with the Hecht equation coded. 2.5x10 sup 2 cm for lambda sub e and 5.0x10 sup - sup 2 cm for lambda sub h were obtained in an electric field of 2500 V/cm: the mu tau products were found to be 1.0x10 sup - sup 1 cm sup 2 /V for electrons and 2.0x10 sup - sup 5 cm sup 2 /V for holes. This method is reasonable to obtain lambda sub e and lambda sub h , which are necessary to correct the distortion caused by tailing in X-ray spectra.

  19. Lithium-ion Energy Storage at Very Low Temperatures Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Li-ion batteries with specific energy >180 Wh/kg, calendar life (>15years), and a wide operating temperature range (-60oC to 60oC) are crucial for the...

  20. Crystal Identification in Dual-Layer-Offset DOI-PET Detectors Using Stratified Peak Tracking Based on SVD and Mean-Shift Algorithm

    Science.gov (United States)

    Wei, Qingyang; Dai, Tiantian; Ma, Tianyu; Liu, Yaqiang; Gu, Yu

    2016-10-01

    An Anger-logic based pixelated PET detector block requires a crystal position map (CPM) to assign the position of each detected event to a most probable crystal index. Accurate assignments are crucial to PET imaging performance. In this paper, we present a novel automatic approach to generate the CPMs for dual-layer offset (DLO) PET detectors using a stratified peak tracking method. In which, the top and bottom layers are distinguished by their intensity difference and the peaks of the top and bottom layers are tracked based on a singular value decomposition (SVD) and mean-shift algorithm in succession. The CPM is created by classifying each pixel to its nearest peak and assigning the pixel with the crystal index of that peak. A Matlab-based graphical user interface program was developed including the automatic algorithm and a manual interaction procedure. The algorithm was tested for three DLO PET detector blocks. Results show that the proposed method exhibits good performance as well as robustness for all the three blocks. Compared to the existing methods, our approach can directly distinguish the layer and crystal indices using the information of intensity and offset grid pattern.

  1. [Study on the axial strain sensor of birefringence photonic crystal fiber loop mirror based on the absolute integral of the monitoring peak].

    Science.gov (United States)

    Jiang, Ying; Zeng, Jie; Liang, Da-Kai; Wang, Xue-Liang; Ni, Xiao-Yu; Zhang, Xiao-Yan; Li, Ji-Feng; Luo, Wen-Yong

    2013-12-01

    In the present paper, the theoretical expression of the wavelength change and the axial strain of birefringence fiber loop mirror is developed. The theoretical result shows that the axial strain sensitivity of birefringence photonic crystal fiber loop mirror is much lower than conventional birefringence fiber loop mirror. It is difficult to measure the axial strain by monitoring the wavelength change of birefringence photonic crystal fiber loop mirror, and it is easy to cause the measurement error because the output spectrum is not perfectly smooth. The different strain spectrum of birefringence photonic crystal fiber loop mirror was measured experimentally by an optical spectrum analyzer. The measured spectrum was analysed. The results show that the absolute integral of the monitoring peak decreases with increasing strain and the absolute integral is linear versus strain. Based on the above results, it is proposed that the axial strain can be measured by monitoring the absolute integral of the monitoring peak in this paper. The absolute integral of the monitoring peak is a comprehensive index which can indicate the light intensity of different wavelength. This method of monitoring the absolute integral of the monitoring peak to measure the axial strain can not only overcome the difficulty of monitoring the wavelength change of birefringence photonic crystal fiber loop mirror, but also reduce the measurement error caused by the unsmooth output spectrum.

  2. Organic materials irradiated at very low temperature and at different stopping powers: examples of polyethylene and of cyclohexane molecules trapped in matrix; Materiaux organiques irradies a tres basse temperature et a differents pouvoirs d'arret: cas du polyethylene et des molecules de cyclohexane isolees en matrice

    Energy Technology Data Exchange (ETDEWEB)

    Melot, M

    2003-10-15

    This thesis concerns the formation mechanisms of defects created in organic materials during irradiation under vacuum, at very low temperature and at different electronic stopping powers. Analysis have been realised by infrared spectroscopy. The first part concerns polyethylene. Irradiating at 8 K allows to dissociate the direct irradiation effects (in cage reactions) and the radical recombination effects. According to the considered chemical groups, the radical mobility leads to very different changes for the formation radiochemical yields. The second part concerns the irradiation of cyclohexane molecules trapped in a solid argon matrix. We evaluate the contribution of intermolecular and intramolecular reactions. The intermolecular reactions have limited consequences when using low ionising radiations but are crucial for heavy ion irradiations. (author)

  3. Anomalous peak in the thermopower of YBa sub 2 Cu sub 3 O sub 7 minus. delta. single crystals: A possible fluctuation effect

    Energy Technology Data Exchange (ETDEWEB)

    Howson, M.A. (Department of Physics, University of Leeds, Leeds LS2 9JT, United Kingdom (GB)); Salamon, M.B. (National Institute of Standards and Technology, Gaithersburg, Maryland 20899 Department of Physics and Materials Research Laboratory, University of Illinois, Urbana-Champaign, Illinois 61801 (USA)); Friedmann, T.A.; Rice, J.P.; Ginsberg, D. (Department of Physics and Materials Research Laboratory, University of Illinois, Urbana-Champaign, Illinois 61801 (USA))

    1990-01-01

    We present results for the thermopower of five crystals of YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} from the transition temperature {ital T}{sub {ital c}} to 250 K and in magnetic fields to 2 T. The thermopower is approximately {minus}4 {mu}V/K at 250 K for all samples, with a broad phonon drag peak around 150 K. Sharp peaks in the thermopower are observed in the vicinity of {ital T}{sub {ital c}}. The thermopower is qualitatively the same for all crystals except one that was annealed at 650 {degree}C in oxygen. That crystal had a positive thermopower and exhibited no peak at {ital T}{sub {ital c}}. After a reanneal in oxygen at 400 {degree}C, the negative thermopower and peak at {ital T}{sub {ital c}} appeared. We discuss the possibility that the anomalous peak at {ital T}{sub {ital c}} is a fluctuation effect and suggest a simple kinetic argument for the presence of a divergent fluctuation contribution.

  4. Peak effect studies in single crystals CeRu2 and 2H-NbS2

    Indian Academy of Sciences (India)

    and the flux pinning produces an anomalous peak in Jc, before it collapses to zero at (or just before) the superconductor–normal phase boundary (Hc2/Tc(H) line). This phenomenon is known as the peak effect and it signals a transition from an ordered state to a disordered state in the flux line lattice (FLL), with proliferation ...

  5. Second and third peaks in the non-resonant microwave absorption spectra of superconducting Bi2212 crystals

    CSIR Research Space (South Africa)

    Srinivasu, V V

    2010-04-01

    Full Text Available -Tc Superconductors (HTS) [1] and followed by others [2–6], NMA has evolved into a powerful spectroscopic tool to probe the superconductiv- ity properties in HTS, such as granularity, critical current density and fluxon viscosity coefficient, etc. [7–14]. NMA... spectra in anisotropic superconductors, such as Bi2212 and Bi 2223 powders, single crystals and films, showed new and V.V. Srinivasu (�) Materials Science and Manufacturing, Council for Scientific and Industrial Research (CSIR), Pretoria 0001, South...

  6. Collective vortex pinning and merging of the irreversibility line and second peak effect in optimally doped Ba1-xKxBiO3 single crystals

    Science.gov (United States)

    Jiao, Yanjing; Cheng, Wang; Deng, Qiang; Yang, Huan; Wen, Hai-Hu

    2018-02-01

    Measurements on magnetization and relaxation have been carried out on an optimally doped Ba1-xKxBiO3+δ single crystal with Tc = 31.3 K. Detailed analysis is undertaken on the data. Both the dynamical relaxation and conventional relaxation have been measured leading to the self-consistent determination of the magnetization relaxation rate. It is found that the data are well described by the collective pinning model leading to the glassy exponent of about μ ≈ 1.64-1.68 with the magnetic fields of 1 and 3 T. The analysis based on Maley's method combining with the conventional relaxation data allows us to determine the current dependent activation energy U which yields a μ value of about 1.23-1.29 for the magnetic fields of 1 and 3 T. The second magnetization peaks appear in wide temperature region from 2 K to 24 K. The separation between the second peak field and the irreversibility field becomes narrow when temperature is increased. When the two fields are close to each other, we find that the second peak evolves into a step-like transition of magnetization. Finally, we present a vortex phase diagram and demonstrate that the vortex dynamics in Ba1-xKxBiO3 can be used as a model system for studying the collective vortex pining.

  7. An analytical model for the determination of crystallite size and crystal lattice microstrain distributions in nanocrystalline materials from the variance of the X-ray diffraction peaks

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez-Bajo, F. [Universidad de Extremadura, Departamento de Fisica Aplicada, Badajoz (Spain); Ortiz, A.L. [Universidad de Extremadura, Departamento de Ingenieria Mecanica, Energetica y de los Materiales, Badajoz (Spain); Cumbrera, F.L. [Universidad de Extremadura, Departamento de Fisica, Badajoz (Spain)

    2009-01-15

    An analytical model for the determination of crystallite size and crystal lattice microstrain distributions in nanocrystalline (nc) materials by X-ray diffractometry (XRD) is presented. It entails generalizing the variance method to establish analytically the connection between the variance coefficients of the physically broadened XRD peaks and the characteristic parameters of explicit distributions of crystallite sizes and crystal lattice microstrains, which results in a more detailed characterization of the nc-materials. The proposed model is generic in nature and has the potential to be used under the assumption of different mathematical functions for the two distributions, which suggests that it may have an important role to play in the characterization of nc-materials. Nevertheless, the specialization to the case of nc-materials with log-normal crystallite size distribution and three typical types of lattice microstrains is used as an illustration and to formulate explicit analytical expressions of interest. Finally, the usefulness of the proposed model is demonstrated on standard XRD profiles. (orig.)

  8. Crack Progression during Sustained-Peak Low-Cycle Fatigue in Single-Crystal Ni-Base Superalloy René N5

    Science.gov (United States)

    Suzuki, A.; Gigliotti, M. F. X.; Hazel, B. T.; Konitzer, D. G.; Pollock, T. M.

    2010-04-01

    Crack progression during compressive sustained-peak low-cycle fatigue (SPLCF) was examined in vapor phase aluminide coated single-crystal Ni-base superalloy René N5. Strain-controlled tests with a 120-second hold at compression were conducted at 1366 K (1093 °C) with A = -1 ( R = -∞) and 0.35 pct total strain range, and were terminated at selected fractions of predicted life. Crack lengths on the surface and crack depth in longitudinal sections were examined for each specimen. All cracks appeared to have initiated at the coating surface. Failed specimens showed that cracks initially grew on (001), perpendicular to the stress axis, and then deflected to other crystallographic planes. Interrupted test specimens showed crevices initiated on the coating surface at less than 10 pct of the predicted life. The depths of crevices into the coating increased with cyclic exposure, but they did not penetrate into the substrate through the interdiffusion zone (IDZ) until about 80 pct of predicted life. Stress relaxation during compressive hold results in residual tension upon unloading. These results suggest that improving creep resistance of the substrate alloy and developing a coating system that can delay crack penetration into the substrate are keys for improved SPLCF life.

  9. Determining Magma Mixing Duration Prior to the 1915 Eruption of Lassen Peak, California by Comparing Experimental Growth of Reaction Rims and Natural Olivine Crystals in Black Dacite

    Science.gov (United States)

    Graham, N. A.; Schwab, B. E.; Castro, J. M.; Clynne, M. A.

    2015-12-01

    Lassen Peak, located in northern California, last erupted in 1915 producing hybrid black dacite containing xenocrystic olivine grains with morphologically complex reaction rims of orthopyroxene. These rims are interpreted to have grown during magma mixing/mingling of admixed basaltic andesite and dacite reservoir magma prior to eruption. Reaction rim growth rates were determined from a series of hydrothermal experiments performed on starting materials consisting of powdered natural dacite pumice from the 1915 eruption and ~5 wt. % of Fo85 olivine separated from a spinel lherzolite xenolith (UM-5) from Kilbourne Hole, NM to constrain the length of time between magma recharge and eruption. Time series experiments were performed with run durations of 50, 100, 200, 400, and 600 hours at 50 and 100 MPa, 825oC and 875oC. The experiments produced a range in reaction rim growth rates where rim thickness generally increased with time. Average rim growth rate for each series is as follows: 0.031 μm²h-1 for 50 MPa at 825oC, 0.010 μm²h-1 for 50 MPa at 875oC, 0.158 μm²h-1 for 100 MPa at 825oC, and 0.088 μm²h-1 for 100 MPa at 875oC. Overall, the 100 MPa experiments resulted in faster growth rates and thicker reaction rims than the 50 MPa experiments. At a given pressure, the higher temperature (875 oC) experiments show slower average growth rates, but thicker reaction rims than the 825oC equivalents. This suggests that growth rate is not constant over time, but likely is more rapid at the early stages of the experiments/heating event, and then slows over time. Reaction rim widths on 100 olivine grains from samples of black dacite were determined by analysis of SEM BSE images and average 26.1 ± 21.7 μm. This average rim width corresponds to a range of mixing durations of 5.8 months (100 MPa, 825oC) to 93 months (50 MPa, 875oC). Average reaction duration of 10.6 months (at 100 MPa, 875oC) is most consistent with our previous experimental work on the 1915 dacite. Reaction

  10. Theoretical and Experimental Determination of the Crack Width in Reinforced Concrete at Very Low Temperatures

    NARCIS (Netherlands)

    V.d. Veen, G.

    1990-01-01

    The compressive strength, the tensile splitting strength, the stress strain relationship and the thermal deformation of concrete are determined experimentally as a function of temperature. Theoretical formulae are derived based on the classical bond stress-slip theory to predict crack width and

  11. Accurate potential energy curve for helium dimer retrieved from viscosity coefficient data at very low temperatures

    Science.gov (United States)

    Costa, Éderson D.'M.; Lemes, Nelson H. T.; Braga, João P.

    2017-12-01

    The long range potential of helium-helium interaction, which requires accurate ab initio calculation, due to the small value of the potential depth, approximately 11 K (9 . 5 × 10-4 eV = 0 . 091 kJ / mol) at 2.96 Å, will be obtained in this study by an alternative technique. This work presents a robust and consistent procedure that provides the long range potential directly from experimental data. However, it is difficult to obtain experimental data containing information regarding such a small potential depth. Thereby, sensitivity analysis will be used to circumvent this difficulty, from which viscosity data at lower temperatures (< 5 K) were chosen as appropriate data to be used to retrieve the potential function between 3 and 4 Å. The linear relationship between the potential energy function and the viscosity coefficient will be established under quantum assumptions and the Bose-Einstein statistics. The use of quantum theory is essential, since the temperatures are below 5 K. The potential obtained in this study describes the viscosity with an average error of 1.7% that is less than the experimental error (5%), with the results being similar to those obtained for recent ab initio potentials.

  12. QUANTIFICATION OF GLACIAL EROSION IN THE ALPS USING VERY LOW-TEMPERATURE THERMOCHRONOLOGY (OSL & AHe)

    Science.gov (United States)

    Champagnac, J.; Herman, F.; Rhodes, E. J.; Fellin, M.; Jaiswal, M.; Schwenninger, J.; Reverman, R. L.

    2009-12-01

    The impact of glaciations on the topography of the Alps is still unclear: Long-term denudation rate determined by low-T thermochronology are in the range of 0.2 to 1 mm/yr, and increased during the Plio-Quaternary by 3 fold (Vernon et al., 2008). Such an increase is also documented by peri-alpine sediment budget (Kuhleman, 2000), with a similar increase in sediment yields since 5-3 Ma. This increase was considered as evidence of a climatically-driven surface process change, attributed to increased precipitation (Cederbom et al., 2004) and erosion by glacial processes (Champagnac et al., 2007). The timing of the onset of intense glacial erosion as well as its rates are still ambiguous. The glacial erosion seems to have accelerated around 0.9 Ma as suggested by the ten fold increase of incision rates of a valley in the Central Alps (Häuselmann et al., 2007), and by information about vegetation and sedimentologic changes (Muttoni et al., 2003). There is however no direct quantification of topographic change during the Plio-Quaternary. We present here how we use OSL-thermochronology, a new thermochronometer of exceptionally low closure temperature (about 30°-40°C) (Herman et al subm.), new {U-Th}/He on apatites data, and a glacial erosion model (Herman and Braun 2008) to estimate topographic changes in the Alps in response to glaciations. Because of their low closure temperature, OSL and AHe thermochronology enables quantification of events of less than 1 Ma at very small wavelength of the topography. We collected two vertical profiles, one in the Zermatt Valley (Valais) and one in Maurienne Valley (Savoy). We infer from these results changes in topography, date and quantify relief creation under glacial-interglacial cycles. Cederbom, C.E, et al., Climate induced rebound and exhumation of the European Alps. Geology 32, 709-712 (2000). Champagnac, J.-D., et al., Quaternary erosion-induced isostatic rebound in the western Alps. Geology 35, 195-198 (2007). Haüselmann P., et al.,et al. Abrupt glacial valley incision at 0.8 Ma dated from cave deposits in Switzerland. Geology 35, 33-42 (2007). Herman F. and Braun J. Evolution of the glacial landscape of the Southern Alps of New Zealand: Insights from a glacial erosion model, J. Geophys. Res., 113, F02009, doi:10.1029/2007JF000807 (2008). Herman F., Rhodes E.J. and Braun J. A new thermochronometer reveals steady state relief and exhumation in a small active orogen during the last glacial cycle, submitted. Kuhlemann J., et al., Quantifying tectonic versus erosive denudation by the sediment budget: the Miocene core complexes of the Alps, Tectonophysics 330, 1-23 (2000). Muttoni G., et al., Onset of major Pleistocene glaciations in the Alps. Geology 31, 989-992 (2003). Vernon, A.J., et al., Increase in late Neogene denudation of the European Alps confirmed by analysis of a fission-track thermochronology database. Earth and Planetary Science Letters, 270 (3-4), pp. 316-329 (2008).

  13. Flux peaking of 7-12 keV deuterons at channeling in TiD2 crystal and enhancement of neutrons yield in d(d,n)3He reaction

    Science.gov (United States)

    Tukhfatullin, T. A.; Pivovarov, Yu. L.; Dudkin, G. N.; Eikhorn, Y. L.; Kuznetsov, S. I.

    2017-07-01

    To study the reactions between light nuclei (dd, pd, d3He, d4He) with an ultralow collision energy, there is a need in the information on the yield of neutrons in the reaction d(d,n)3He versus the angular and spatial distribution of particles during the channeling process in thin crystals. The authors of recent publications suppose that the increase in the yield of neutrons and the occurrence of the orientation effect are connected with the screening and channeling effects. In this paper, the probability of increasing the yield of neutrons is studied depending on the energy, the angular and spatial distribution, as well as on the focusing of the incident deuterons at the locations of embedded deuterons (so-called flux peaking effect) during the dd reaction in TiD2 crystals, using computational modeling. The trajectories of deuterons in the crystal were modeled using a computer code Basic Channeling with Mathematica™ (BCM-1.0). The results of the theoretical study concerning the effect of plane channeling of ultralow energy deuterons on the relative probability of dd-synthesis are in good agreement with the experimental data. To improve the efficiency of the neutrons yield, the direction and recommendations are given for future experimental studies.

  14. Peak flow meter (image)

    Science.gov (United States)

    A peak flow meter is commonly used by a person with asthma to measure the amount of air that can be ... become narrow or blocked due to asthma, peak flow values will drop because the person cannot blow ...

  15. Why is the diffraction peak a peak?

    CERN Document Server

    Cornille, H

    1975-01-01

    It is proved that the high-energy differential cross section for an elastic process has a maximum exactly in the forward direction and that the slope of the diffraction peak is at most (log s)/sup 2/. The widths of the diffraction peaks defined by the absorptive part and the differential cross section are compared. The assumptions are that the amplitude is dominated by the even signature amplitude and that the total cross section, if it decreases, decreases less fast than s/sup -1/2/. Strictly speaking, the results hold only for a sequence of energies approaching infinity. The proofs are given for the spin-O- spin-O case, but it is not unreasonable to hope that they can be generalized to arbitrary spins. (13 refs).

  16. Production of polarized ^3He gas by means of very low temperature and high magnetic field

    OpenAIRE

    田中, 正義; 猪股, 亨; 高橋, 豊; 藤原, 守; 輿曽井, 優; 郡, 英輝; 太田, 岳史; 森崎, 知治; 国松, 貴之

    2009-01-01

    最近、我々は極低温(~ 4mK)と超強磁場(最大17T)を用いた所謂Brute force法による偏極固体^3Heの生成と急速解凍による偏極^3Heプロジェクトをスタートした。このプロジェクトの目的は、偏極^3Heガスをハイパー偏極^3He MR(I 核磁気共鳴イメージング)に用いて医学に応用することである。^3He-^4He希釈冷凍器に取り付けられるポメンランチュークセルが設計され、製作されている。最初のテスト実験では、ポメランチュクセルは低い冷凍能力を有する^3He-^4He希釈冷凍器(IBC; In Beam Cryostat)に取り付けられる。そこでは、1Tの超伝導 ソレノイドコイルが用いられる。一方、本実験では、ポメランチュクセルは高い冷凍能力を有する^3He-^4He希釈冷凍器(DRS 2500)に取り付けられる。そこでは、17Tの超伝導ソレノイドコイルが用いられる。このレポートで、我々は、^3Heを偏極させる原理と実験装置の設計・製作の現状を述べる。|Recently, we started a project on polarized ^3He gas gener...

  17. The technique of autoradiography at very low temperature; Technique d'autoradiographie a tres basse temperature

    Energy Technology Data Exchange (ETDEWEB)

    Pellerin, P. [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1959-07-01

    Biological samples frozen in liquid nitrogen (-195 deg. C) acquire the hardness of light metals, enabling the surface for autoradiography to be cut on a milling machine. The autoradiographic exposure is made in saturated nitrogen vapour. The emulsion, on a plastic base, is laid on the milled surface in a dark room and this assembly is then placed above the liquid nitrogen in a foam-teflon container. Measurements show that, a temperature gradient is established between -190 deg. C at the liquid nitrogen surface and -121 deg. C at the top of the closed container. Developing is done at room temperature, the speed of the emulsion being practically unchanged. This technique enables the specimen to be kept far below the freezing-point, from the moment the animal is killed until the plate is developed. Freezing ensures complete absence of chemical diffusion and that the recorded tracer distribution is precisely that obtaining at the time of death. The distribution at different levels can be investigated by milling off successive layers. Pseudo-radiographic effects are wholly non-existent. The enhancement of natural colours in the anatomical elements, brought about by low temperatures, is such that it becomes possible to dispense with staining when making colour autoradiograms of sections. (author) [French] Les sujets congeles dans l'azote liquide (-190 deg. C) acquierent la durete metal leger, ce qui permet de preparer le plan d'autoradiographie par fraisage sur machine-outil. L'exposition autoradiographique est elle-meme effectuee dans la vapeur de l'azote liquide, en chambre noire, l'emulsion portee par une plaque plastique est appliquee contre la surface fraisee. Cet ensemble est dispose au-dessus de l'azote liquide contenu dans un recipient en mousse de teflon. Les mesures montrent qu'un gradient de temperature s'etablit entre -190 deg. C a la surface de l'azote liquide et -120 deg. C, a la partie superieure du recipient ferme. Le developpement a lieu a temperature ordinaire et la sensibilite de l'emulsion n'est pas appreciabdement modifiee. Cette technique permet de maintenir le bloc tres au-dessous de la temperature de congelation, des la mort de l'animal jusqu'au developpement; toute diffusion chimique est supprimee et la repartition de la substance radioactive saisie sur l'autoradiographie a l'instant exact de la mort par congelation. Des fraisages successifs permettent d'etudier la repartition de la substance radioactive, a toutes les profondeurs. L'absence d'effets pseudo-radiographiques est totale. Enfin, le renforcement des couleurs naturelles des elements anatomiques par cette tres basse temperature est considerable, ce qui permet de realigner l'autoradiographie en couleurs de le coupe processus de coloration. (auteur)

  18. EXAFS study of non-spherical nanoparticles in oxidized iron thin films grown by sputtering at very low temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez-Villacorta, F. [Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Cientificas, Campus de Cantoblanco, 28049 Madrid (Spain)]. E-mail: felixjv@icmm.csic.es; Munoz-Martin, A. [Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Cientificas, Campus de Cantoblanco, 28049 Madrid (Spain); Prieto, C. [Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Cientificas, Campus de Cantoblanco, 28049 Madrid (Spain)

    2005-08-15

    A detailed study of EXAFS data has been used to evaluate the microstructural properties of grains forming the sample. A new model is proposed to determine the average dimensions of nanometric thin film iron grains, considering them as elongated particles, and taking into account polarization of the incident X-ray. Results show a clear decrease of grain size as the preparation temperature diminishes, and they are in very good agreement with previous measurements determined by X-ray diffraction techniques.

  19. Study of nanoconductive and magnetic properties of nanostructured iron films prepared by sputtering at very low temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez-Villacorta, F. [SpLine, Spanish CRG Beamline at the European Synchrotron Radiation Facilities, ESRF (France); Munuera, C.; Ocal, C. [Instituto de Ciencia de Materiales de Barcelona. Consejo Superior de Investigaciones Cientificas (Spain); Prieto, C., E-mail: cprieto@icmm.csic.e [Instituto de Ciencias de Materiales de Madrid, Consejo Superior de Investigaciones Cientificas (Spain)

    2010-05-15

    A combined study of the surface nanostructure and electrical characteristics of iron thin films prepared on naturally passivated silicon wafers is presented. By means of conductive-scanning force microscopy, the influence of the substrate temperature during film preparation on both surface morphology and conductivity response is investigated. In addition, magnetic properties of these films are reported and correlated with the nanostructural properties. Films prepared at 200 K show granular core-shell magnetic behaviour exhibiting exchange bias. Both conductive and magnetic data indicate that samples prepared at low temperature behave as a percolated network of nanometric metallic iron clusters (with typical sizes of 20 nm) interconnected by oxidized chains (of 10 nm in diameter), showing an excellent system for nanotechnological exchange bias applications.

  20. Peak Experience Project

    Science.gov (United States)

    Scott, Daniel G.; Evans, Jessica

    2010-01-01

    This paper emerges from the continued analysis of data collected in a series of international studies concerning Childhood Peak Experiences (CPEs) based on developments in understanding peak experiences in Maslow's hierarchy of needs initiated by Dr Edward Hoffman. Bridging from the series of studies, Canadian researchers explore collected…

  1. Peak-interviewet

    DEFF Research Database (Denmark)

    Raalskov, Jesper; Warming-Rasmussen, Bent

    Peak-interviewet er en særlig effektiv metode til at gøre ubevidste menneskelige ressourcer bevidste. Fokuspersonen (den interviewede) interviewes om en selvvalgt, personlig succesoplevelse. Terapeuten/coachen (intervieweren) spørger ind til processen, som ledte hen til denne succes. Herved afdæk...

  2. Automated asteroseismic peak detections

    Science.gov (United States)

    de Montellano, A. García Saravia Ortiz; Hekker, S.; Themeßl, N.

    2018-01-01

    Space observatories such as Kepler have provided data that can potentially revolutionise our understanding of stars. Through detailed asteroseismic analyses we are capable of determining fundamental stellar parameters and reveal the stellar internal structure with unprecedented accuracy. However, such detailed analyses, known as peak bagging, have so far been obtained for only a small percentage of the observed stars while most of the scientific potential of the available data remains unexplored. One of the major challenges in peak bagging is identifying how many solar-like oscillation modes are visible in a power density spectrum. Identification of oscillation modes is usually done by visual inspection which is time-consuming and has a degree of subjectivity. Here, we present a peak detection algorithm specially suited for the detection of solar-like oscillations. It reliably characterises the solar-like oscillations in a power density spectrum and estimates their parameters without human intervention. Furthermore, we provide a metric to characterise the false positive and false negative rates to provide further information about the reliability of a detected oscillation mode or the significance of a lack of detected oscillation modes. The algorithm presented here opens the possibility for detailed and automated peak bagging of the thousands of solar-like oscillators observed by Kepler.

  3. Equilibrium shape of (4)He crystal under zero gravity below 200 mK.

    Science.gov (United States)

    Takahashi, Takuya; Ohuchi, Haruka; Nomura, Ryuji; Okuda, Yuichi

    2015-10-01

    Equilibrium crystal shape is the lowest energy crystal shape that is hardly realized in ordinary crystals because of their slow relaxation. (4)He quantum crystals in a superfluid have been expected as unique exceptions that grow extremely fast at very low temperatures. However, on the ground, gravity considerably deforms the crystals and conceals the equilibrium crystal shape, and thus, gravity-free environment is needed to observe the equilibrium shape of (4)He. We report the relaxation processes of macroscopic (4)He crystals in a superfluid below 200 mK under zero gravity using a parabolic flight of a jet plane. When gravity was removed from a gravity-flattened (4)He crystal, the crystal rapidly transformed into a shape with flat surfaces. Although the relaxation processes were highly dependent on the initial condition, the crystals relaxed to a nearly homothetic shape in the end, indicating that they were truly in an equilibrium shape minimizing the interfacial free energy. Thanks to the equilibrium shape, we were able to determine the Wulff's origin and the size of the c-facet together with the vicinal surface profile next to the c-facet. The c-facet size was extremely small in the quantum crystals, and the facet-like flat surfaces were found to be the vicinal surfaces. At the same time, the interfacial free energy of the a-facet and s-facet was also obtained.

  4. Kitt Peak speckle camera.

    Science.gov (United States)

    Breckinridge, J B; McAlister, H A; Robinson, W G

    1979-04-01

    The speckle camera in regular use at Kitt Peak National Observatory since 1974 is described in detail. The design of the atmospheric dispersion compensation prisms, the use of film as a recording medium, the accuracy of double star measurements, and the next generation speckle camera are discussed. Photographs of double star speckle patterns with separations from 1.4 sec of arc to 4.7 sec of arc are shown to illustrate the quality of image formation with this camera, the effects of seeing on the patterns, and to illustrate the isoplanatic patch of the atmosphere.

  5. Peak-Finding Algorithms.

    Science.gov (United States)

    Hung, Jui-Hung; Weng, Zhiping

    2017-03-01

    Microarray and next-generation sequencing technologies have greatly expedited the discovery of genomic DNA that can be enriched using various biochemical methods. Chromatin immunoprecipitation (ChIP) is a general method for enriching chromatin fragments that are specifically recognized by an antibody. The resulting DNA fragments can be assayed by microarray (ChIP-chip) or sequencing (ChIP-seq). This introduction focuses on ChIP-seq data analysis. The first step of analyzing ChIP-seq data is identifying regions in the genome that are enriched in a ChIP sample; these regions are called peaks. © 2017 Cold Spring Harbor Laboratory Press.

  6. Phonon interactions with methyl radicals in single crystals

    Directory of Open Access Journals (Sweden)

    James W. Wells

    2017-04-01

    Full Text Available The high temperature ESR spectra’s anomalous appearance at very low temperatures for the methyl radical created in single crystals is explained by magnetic dipole interactions with neighboring protons. These protons acting via phonon vibrations induce resonant oscillations with the methyl group to establish a very temperature sensitive ‘‘relaxation’’ mode that allows the higher energy ‘‘E’’ state electrons with spin 12 to ‘‘decay’’ into ‘‘A’’ spin 12 states. Because of the amplitude amplification with temperature, the ‘‘E’’ state population is depleted and the ‘‘A’’ state population augmented to produce the high temperature ESR spectrum. This phenomenon is found to be valid for all but the very highest barriers to methyl group tunneling. In support, a time dependent spin population study shows this temperature evolution in the state populations under this perturbation.

  7. Secondary Crystallization of Isotactic Polystyrene

    NARCIS (Netherlands)

    LEMSTRA, PJ; SCHOUTEN, AJ; CHALLA, G

    1974-01-01

    When isotactic polystyrene (i-PS) is crystallized from the melt or from the glassy state at rather large supercooling an additional melting peak appears on the curve during scanning in a differential calorimeter. The overall rate of crystallization deduced from the total peak areas as a function of

  8. Peak flow meter use - slideshow

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/presentations/100202.htm Peak flow meter use - Series—Peak flow meter use - part one To use the sharing ... slide 7 out of 7 Overview A peak flow meter helps you check how well your asthma ...

  9. Order causes secondary Bragg peaks in soft materials

    Science.gov (United States)

    Förster, Stephan; Timmann, Andreas; Schellbach, Carsten; Frömsdorf, Andreas; Kornowski, Andreas; Weller, Horst; Roth, Stephan V.; Lindner, Peter

    2007-11-01

    Highly ordered soft materials exhibit Bragg peaks that cannot be indexed assuming homogeneous crystal structures. Their origin has been attributed to changes in the crystal structure that are induced by the ordering process such as by application of external fields. This would restrict the use for the generation of highly ordered nano- and microstructured materials where a homogeneous crystal structure is a key requirement. Here, we demonstrate that these Bragg peaks are an inherent property of homogeneous ordered soft materials related to the finite coherence of their crystalline lattice. Their consideration allows a detailed and quantitative analysis of the diffraction patterns of seemingly unrelated materials such as lyotropic liquid-crystalline phases, mesoporous materials, colloidal dispersions, block copolymers, electrorheological fluids and photonic crystals. It further enables us to develop a concise picture of order, line density, field-induced orientation and epitaxial relations for soft-material lattices.

  10. Control of the wetting properties of 4He crystals in superfluid

    Science.gov (United States)

    Takahashi, T.; Minezaki, H.; Suzuki, A.; Obara, K.; Itaka, K.; Nomura, R.; Okuda, Y.

    2016-05-01

    To investigate whether it is possible to control the wetting of 4He crystals on a wall in superfluid, the contact angles of 4He crystals were measured on rough and smooth walls at very low temperatures. A rough wall was prepared in a simple manner in which a commercially available coating agent for car mirrors, which makes the glass surface superhydrophobic, was used to coat a glass plate. The contact angles of 4He crystals were increased by approximately 10° on the rough wall coated with the agent. Therefore, the increase in the repellency of 4He crystals in superfluid was demonstrated to be possible on a very rough surface. The enhancement of the contact angles and a scanning electron microscopy image of the coated surface both suggest that a Cassie-Baxter state of 4He crystals was realized on the surface; the crystals did not have full contact with the wall, but entrapped superfluid was present beneath the crystals in the hollow parts of the rough wall.

  11. PEAK SHAVING CONSIDERING STREAMFLOW UNCERTAINTIES

    African Journals Online (AJOL)

    user

    The main thrust of this paper is peak shaving with a Stochastic hydro model. In peak sharing, the amount of hydro energy scheduled may be a minimum but it serves to replace less efficient thermal units. The sample system is die Kainji .... ni = average number of times the system load is in state Li in period k. 5. Numerical ...

  12. Ultrasonic Transducer Peak-to-Peak Optical Measurement

    Directory of Open Access Journals (Sweden)

    Pavel Skarvada

    2012-01-01

    Full Text Available Possible optical setups for measurement of the peak-to-peak value of an ultrasonic transducer are described in this work. The Michelson interferometer with the calibrated nanopositioner in reference path and laser Doppler vibrometer were used for the basic measurement of vibration displacement. Langevin type of ultrasonic transducer is used for the purposes of Electro-Ultrasonic Nonlinear Spectroscopy (EUNS. Parameters of produced mechanical vibration have to been well known for EUNS. Moreover, a monitoring of mechanical vibration frequency shift with a mass load and sample-transducer coupling is important for EUNS measurement.

  13. Hubbert's Peak: A Physicist's View

    Science.gov (United States)

    McDonald, Richard

    2011-11-01

    Oil and its by-products, as used in manufacturing, agriculture, and transportation, are the lifeblood of today's 7 billion-person population and our 65T world economy. Despite this importance, estimates of future oil production seem dominated by wishful thinking rather than quantitative analysis. Better studies are needed. In 1956, Dr. M.King Hubbert proposed a theory of resource production and applied it successfully to predict peak U.S. oil production in 1970. Thus, the peak of oil production is referred to as ``Hubbert's Peak.'' Prof. Al Bartlett extended this work in publications and lectures on population and oil. Both Hubbert and Bartlett place peak world oil production at a similar time, essentially now. This paper extends this line of work to include analyses of individual countries, inclusion of multiple Gaussian peaks, and analysis of reserves data. While this is not strictly a predictive theory, we will demonstrate a ``closed'' story connecting production, oil-in-place, and reserves. This gives us the ``most likely'' estimate of future oil availability. Finally, we will comment on synthetic oil and the possibility of carbon-neutral synthetic oil for a sustainable future.

  14. Do two-level systems and boson peak persist or vanish in hyperaged geological glasses of amber?

    Science.gov (United States)

    Pérez-Castañeda, T.; Jiménez-Riobóo, R. J.; Ramos, M. A.

    2016-03-01

    In this work, we extend, review and jointly discuss earlier experiments conducted by us in hyperaged geological glasses, either in Dominican amber (20 million years old) or in Spanish amber from El Soplao (110 million years old). After characterization of their thermodynamic and elastic properties (using Differential Scanning Calorimetry around the glass-transition temperature, and measuring mass density and sound velocity), their specific heat was measured at low and very low temperatures. By directly comparing pristine amber samples (i.e. highly stabilized polymer glasses after ageing for millions of years) to the same samples after being totally or partially rejuvenated, we have found that the two most prominent universal "anomalous" low-temperature properties of glasses, namely the tunnelling two-level systems and the so-called "boson peak", persist essentially unchanged in both types of hyperaged geological glasses. Therefore, non-Debye low-energy excitations of glasses appear to be robust, intrinsic properties of non-crystalline solids which do not vanish by accessing to very deep states in the potential energy landscape.

  15. New explanation of Raman peak redshift in nanoparticles

    Science.gov (United States)

    Meilakhs, A. P.; Koniakhin, S. V.

    2017-10-01

    In this letter, we propose a new model that explains the Raman peak downshift observed in nanoparticles with respect to bulk materials. The proposed model takes into account discreteness of the vibrational spectra of nanoparticles. For crystals with a cubic lattice (Diamond, Silicon, Germanium) we give a relation between the displacement of Raman peak position and the size of nanoparticles. The proposed model does not include any uncertain parameters, unlike the conventionally used phonon confinement model (PCM), and can be employed for unambiguous nanoparticles size estimation.

  16. Infrared absorption peaks in nitrogen doped CZ silicon

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, N. [RIAST, Osaka Prefecture University, Gakuen-cho, Sakai, Osaka 599-8570 (Japan); JEITA Nitrogen Measurement WG, 3-11 Kanda-surugadai, Chiyoda-ku, Tokyo 101-0062 (Japan)]. E-mail: inouen@riast.osakafu-u.ac.jp; Nakatsu, M. [RIAST, Osaka Prefecture University, Gakuen-cho, Sakai, Osaka 599-8570 (Japan); Ono, H. [Japan Fine Ceramics Center, 2-4-3 Nishi-shinbashi, Minato-ku, Tokyo 105-0003 (Japan); JEITA Nitrogen Measurement WG, 3-11 Kanda-surugadai, Chiyoda-ku, Tokyo 101-0062 (Japan); Inoue, Y. [Tokyo University of Education, Bunkyo-ku, Tokyo 117-0002 (Japan)

    2006-10-15

    Dependences on annealing temperature and nitrogen concentration were examined for new local vibration mode infrared absorption peaks at 856, 973, 984 and 1002 cm{sup -1} in nitrogen-doped CZ silicon crystal. The new absorption peaks were so weak that two sets of samples were examined for temperature and concentration dependences, respectively, to get reliable results. The peak at 1002 cm{sup -1} behaved similarly for annealing, though much weaker, to the known peaks at 810 and 1018 cm{sup -1} which are attributed to interstitial N pair accompanied by the two oxygen interstitials (NNO {sub i}O {sub i}). This suggests that the origin contains 2 O {sub i} also. It was strong in low concentration regime, which is similar to the behavior of shallow thermal donors. This suggests that the structure contains one nitrogen rather than two (N-O interstitial pair). The results were compared with the electronic transition absorption by shallow thermal donors (STD). The absorptions at 1002 and 240 cm{sup -1} behaved similarly. These suggest that the peak at 1002 cm{sup -1} is likely due to NOO {sub i}O {sub i} which is the candidate for STD. The temperature dependence of the other new peaks was slightly different from each other. Origin of the other peaks is not clear yet.

  17. Crystal face temperature determination means

    Science.gov (United States)

    Nason, D.O.; Burger, A.

    1994-11-22

    An optically transparent furnace having a detection apparatus with a pedestal enclosed in an evacuated ampule for growing a crystal thereon is disclosed. Temperature differential is provided by a source heater, a base heater and a cold finger such that material migrates from a polycrystalline source material to grow the crystal. A quartz halogen lamp projects a collimated beam onto the crystal and a reflected beam is analyzed by a double monochromator and photomultiplier detection spectrometer and the detected peak position in the reflected energy spectrum of the reflected beam is interpreted to determine surface temperature of the crystal. 3 figs.

  18. Effects of sample size on the second magnetization peak in ...

    Indian Academy of Sciences (India)

    *E-mail: yeshurun@mail.biu.ac.il. Abstract. Effects of sample size on the second magnetization peak (SMP) in. Bi2Sr2CaCuO8+δ crystals are ... a termination of the measured transition line at Tl, typically 17–20 K (see figure 1). The obscuring and eventual disappearance of the SMP with decreasing tempera- tures has been ...

  19. Drivers of peak sales for pharmaceutical brands

    NARCIS (Netherlands)

    Fischer, Marc; Leeflang, Peter S. H.; Verhoef, Peter C.

    2010-01-01

    Peak sales are an important metric in the pharmaceutical industry. Specifically, managers are focused on the height-of-peak-sales and the time required achieving peak sales. We analyze how order of entry and quality affect the level of peak sales and the time-to-peak-sales of pharmaceutical brands.

  20. Axion crystals

    Science.gov (United States)

    Ozaki, Sho; Yamamoto, Naoki

    2017-08-01

    The low-energy effective theories for gapped insulators are classified by three parameters: permittivity ɛ, permeability μ, and theta angle θ. Crystals with periodic ɛ are known as photonic crystals. We here study the band structure of photons in a new type of crystals with periodic θ (modulo 2 π) in space, which we call the axion crystals. We find that the axion crystals have a number of new properties that the usual photonic crystals do not possess, such as the helicity-dependent mass gap and nonrelativistic gapless dispersion relation at small momentum. We briefly discuss possible realizations of axion crystals in condensed matter systems and high-energy physics.

  1. Structure and correlations of the flux line lattice in crystalline Nb through the peak effect

    DEFF Research Database (Denmark)

    Gammel, P.L.; Yaron, U.; Ramirez, Y.P.

    1998-01-01

    We have measured the structure of the field cooled flux line lattice (FLL) in single crystal Nb using small angle neutron scattering. Augmented by transport and thermodynamic data, a scenario for the dramatic disordering of the FLL near the peak effect emerges. A precursor to the peak effect...

  2. Spatial peak-load pricing

    Energy Technology Data Exchange (ETDEWEB)

    Arellano, M. Soledad; Serra, Pablo [Universidad de Chile, Dept. of Industrial Engineering, Santiago (Chile)

    2007-03-15

    This article extends the traditional electricity peak-load pricing model to include transmission costs. In the context of a two-node, two-technology electric power system, where suppliers face inelastic demand, we show that when the marginal plant is located at the energy-importing center, generators located away from that center should pay the marginal capacity transmission cost; otherwise, consumers should bear this cost through capacity payments. Since electric power transmission is a natural monopoly, marginal-cost pricing does not fully cover costs. We propose distributing the revenue deficit among users in proportion to the surplus they derive from the service priced at marginal cost. (Author)

  3. Algorithm for systematic peak extraction from atomic pair distribution functions.

    Science.gov (United States)

    Granlund, L; Billinge, S J L; Duxbury, P M

    2015-07-01

    The study presents an algorithm, ParSCAPE, for model-independent extraction of peak positions and intensities from atomic pair distribution functions (PDFs). It provides a statistically motivated method for determining parsimony of extracted peak models using the information-theoretic Akaike information criterion (AIC) applied to plausible models generated within an iterative framework of clustering and chi-square fitting. All parameters the algorithm uses are in principle known or estimable from experiment, though careful judgment must be applied when estimating the PDF baseline of nanostructured materials. ParSCAPE has been implemented in the Python program SrMise. Algorithm performance is examined on synchrotron X-ray PDFs of 16 bulk crystals and two nanoparticles using AIC-based multimodeling techniques, and particularly the impact of experimental uncertainties on extracted models. It is quite resistant to misidentification of spurious peaks coming from noise and termination effects, even in the absence of a constraining structural model. Structure solution from automatically extracted peaks using the Liga algorithm is demonstrated for 14 crystals and for C60. Special attention is given to the information content of the PDF, theory and practice of the AIC, as well as the algorithm's limitations.

  4. The Peak Pairs algorithm for strain mapping from HRTEM images

    Energy Technology Data Exchange (ETDEWEB)

    Galindo, Pedro L. [Departamento de Lenguajes y Sistemas Informaticos, CASEM, Universidad de Cadiz, Pol. Rio San Pedro s/n. 11510, Puerto Real, Cadiz (Spain)], E-mail: pedro.galindo@uca.es; Kret, Slawomir [Institute of Physics, PAS, AL. Lotnikow 32/46, 02-668 Warsaw (Poland); Sanchez, Ana M. [Departamento de Ciencia de los Materiales e Ing. Metalurgica y Q. Inorganica, Facultad de Ciencias, Universidad de Cadiz, Pol. Rio San Pedro s/n. 11510, Puerto Real, Cadiz (Spain); Laval, Jean-Yves [Laboratoire de Physique du Solide, UPR5 CNRS-ESPCI, Paris (France); Yanez, Andres; Pizarro, Joaquin; Guerrero, Elisa [Departamento de Lenguajes y Sistemas Informaticos, CASEM, Universidad de Cadiz, Pol. Rio San Pedro s/n. 11510, Puerto Real, Cadiz (Spain); Ben, Teresa; Molina, Sergio I. [Departamento de Ciencia de los Materiales e Ing. Metalurgica y Q. Inorganica, Facultad de Ciencias, Universidad de Cadiz, Pol. Rio San Pedro s/n. 11510, Puerto Real, Cadiz (Spain)

    2007-11-15

    Strain mapping is defined as a numerical image-processing technique that measures the local shifts of image details around a crystal defect with respect to the ideal, defect-free, positions in the bulk. Algorithms to map elastic strains from high-resolution transmission electron microscopy (HRTEM) images may be classified into two categories: those based on the detection of peaks of intensity in real space and the Geometric Phase approach, calculated in Fourier space. In this paper, we discuss both categories and propose an alternative real space algorithm (Peak Pairs) based on the detection of pairs of intensity maxima in an affine transformed space dependent on the reference area. In spite of the fact that it is a real space approach, the Peak Pairs algorithm exhibits good behaviour at heavily distorted defect cores, e.g. interfaces and dislocations. Quantitative results are reported from experiments to determine local strain in different types of semiconductor heterostructures.

  5. Neurofeedback training for peak performance.

    Science.gov (United States)

    Graczyk, Marek; Pąchalska, Maria; Ziółkowski, Artur; Mańko, Grzegorz; Łukaszewska, Beata; Kochanowicz, Kazimierz; Mirski, Andrzej; Kropotov, Iurii D

    2014-01-01

    One of the applications of the Neurofeedback methodology is peak performance in sport. The protocols of the neurofeedback are usually based on an assessment of the spectral parameters of spontaneous EEG in resting state conditions. The aim of the paper was to study whether the intensive neurofeedback training of a well-functioning Olympic athlete who has lost his performance confidence after injury in sport, could change the brain functioning reflected in changes in spontaneous EEG and event related potentials (ERPs). The case is presented of an Olympic athlete who has lost his performance confidence after injury in sport. He wanted to resume his activities by means of neurofeedback training. His QEEG/ERP parameters were assessed before and after 4 intensive sessions of neurotherapy. Dramatic and statistically significant changes that could not be explained by error measurement were observed in the patient. Neurofeedback training in the subject under study increased the amplitude of the monitoring component of ERPs generated in the anterior cingulate cortex, accompanied by an increase in beta activity over the medial prefrontal cortex. Taking these changes together, it can be concluded that that even a few sessions of neurofeedback in a high performance brain can significantly activate the prefrontal cortical areas associated with increasing confidence in sport performance.

  6. Neurofeedback training for peak performance

    Directory of Open Access Journals (Sweden)

    Marek Graczyk

    2014-11-01

    Full Text Available [b]aim[/b]. One of the applications of the Neurofeedback methodology is peak performance in sport. The protocols of the neurofeedback are usually based on an assessment of the spectral parameters of spontaneous EEG in resting state conditions. The aim of the paper was to study whether the intensive neurofeedback training of a well-functioning Olympic athlete who has lost his performance confidence after injury in sport, could change the brain functioning reflected in changes in spontaneous EEG and event related potentials (ERPs. [b]case study[/b]. The case is presented of an Olympic athlete who has lost his performance confidence after injury in sport. He wanted to resume his activities by means of neurofeedback training. His QEEG/ERP parameters were assessed before and after 4 intensive sessions of neurotherapy. Dramatic and statistically significant changes that could not be explained by error measurement were observed in the patient. [b]conclusion[/b]. Neurofeedback training in the subject under study increased the amplitude of the monitoring component of ERPs generated in the anterior cingulate cortex, accompanied by an increase in beta activity over the medial prefrontal cortex. Taking these changes together, it can be concluded that that even a few sessions of neurofeedback in a high performance brain can significantly activate the prefrontal cortical areas associated with increasing confidence in sport performance.

  7. Crystal rainbows

    Energy Technology Data Exchange (ETDEWEB)

    Neskovic, N. E-mail: nnesko@vin.bg.ac.yu; Petrovic, S

    2003-06-01

    This review is devoted to ion transmission through axial channels of thin crystals. In this process the rainbows occur. The effect is called the crystal rainbow effect. We shall describe its origin and present the experiments in which it has been observed. We shall explain also how the crystal rainbows can be classified using catastrophe theory. This classification has resulted in a universal, simple and accurate approximation to the continuum potential in the channels. Besides, the periodicity of the angular distributions of transmitted ions with the reduced crystal thickness will be considered. It will be introduced via the effect of zero-degree focusing of channeled ions. In addition, we shall mention the doughnut effect in ion channeling, which has proven to be the rainbow effect with tilted crystals. All these considerations will demonstrate clearly the usefulness of the theory of crystal rainbows, which is the proper theory of ion channeling in thin crystals00.

  8. Facility Location with Double-peaked Preferences

    DEFF Research Database (Denmark)

    Filos-Ratsikas, Aris; Li, Minming; Zhang, Jie

    2015-01-01

    We study the problem of locating a single facility on a real line based on the reports of self-interested agents, when agents have double-peaked preferences, with the peaks being on opposite sides of their locations. We observe that double-peaked preferences capture real-life scenarios and thus...... complement the well-studied notion of single-peaked preferences. We mainly focus on the case where peaks are equidistant from the agents’ locations and discuss how our results extend to more general settings. We show that most of the results for single-peaked preferences do not directly apply to this setting...

  9. Chiral symmetry breaking in unstirred crystallization

    Energy Technology Data Exchange (ETDEWEB)

    Szurgot, M. [Center of Mathematics and Physics, Technical University of Lodz (Poland)

    2012-01-15

    Statistics of nucleation of chiral forms of sodium bromate from unstirred aqueous solutions was studied. It was established that bimodal, trimodal and unimodal distributions of enantiomers are obtained in unstirred crystallization. It was also found out that probabilities of the creation of L or D crystals and racemates R, as well as the presence of D, L, and R peaks in distributions depend on crystallizer size, supersaturation and temperature. Nucleation at low supersaturations in small, closed crystallizers leads to the formation of pure enantiomers, and to bimodal distributions with D and L peaks at any temperature. At high supersaturations in large, open crystallizers the formation of racemates and unimodal distributions with racemate R peaks results. In open crystallizers at the lowest temperatures and at the highest temperatures used in crystallization from aqueous solution racemates of sodium bromate are preferentially formed, but in a wide range of intermediate-temperatures apart from racemates, pure enantiomers are efficiently formed which leads to trimodal distributions. The spontaneous formation of pure enantiomers in crystallization from unstirred, unseeded solutions is caused by the chiral symmetry breaking phenomenon, the same as that discovered in stirred crystallization. The conservation of chiral symmetry is, in unstirred crystallization, one of the two possibilities, and the other one is the breakage of symmetry. Both of them occur in nature. (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  10. Osteoporosis: Peak Bone Mass in Women

    Science.gov (United States)

    ... Home Osteoporosis Osteoporosis: Peak Bone Mass in Women Osteoporosis: Peak Bone Mass in Women Bones are the ... No. 15-7891 Last Reviewed 2015-06 NIH Osteoporosis and Related Bone Diseases ~ National Resource Center 2 ...

  11. A model to forecast peak spreading.

    Science.gov (United States)

    2012-04-01

    As traffic congestion increases, the K-factor, defined as the proportion of the 24-hour traffic volume that occurs during the peak hour, may decrease. This behavioral response is known as peak spreading: as congestion grows during the peak travel tim...

  12. Protein Crystallization

    Science.gov (United States)

    Chernov, Alexander A.

    2005-01-01

    Nucleation, growth and perfection of protein crystals will be overviewed along with crystal mechanical properties. The knowledge is based on experiments using optical and force crystals behave similar to inorganic crystals, though with a difference in orders of magnitude in growing parameters. For example, the low incorporation rate of large biomolecules requires up to 100 times larger supersaturation to grow protein, rather than inorganic crystals. Nucleation is often poorly reproducible, partly because of turbulence accompanying the mixing of precipitant with protein solution. Light scattering reveals fluctuations of molecular cluster size, its growth, surface energies and increased clustering as protein ages. Growth most often occurs layer-by-layer resulting in faceted crystals. New molecular layer on crystal face is terminated by a step where molecular incorporation occurs. Quantitative data on the incorporation rate will be discussed. Rounded crystals with molecularly disordered interfaces will be explained. Defects in crystals compromise the x-ray diffraction resolution crucially needed to find the 3D atomic structure of biomolecules. The defects are immobile so that birth defects stay forever. All lattice defects known for inorganics are revealed in protein crystals. Contribution of molecular conformations to lattice disorder is important, but not studied. This contribution may be enhanced by stress field from other defects. Homologous impurities (e.g., dimers, acetylated molecules) are trapped more willingly by a growing crystal than foreign protein impurities. The trapped impurities induce internal stress eliminated in crystals exceeding a critical size (part of mni for ferritin, lysozyme). Lesser impurities are trapped from stagnant, as compared to the flowing, solution. Freezing may induce much more defects unless quickly amorphysizing intracrystalline water.

  13. Computational crystallization.

    Science.gov (United States)

    Altan, Irem; Charbonneau, Patrick; Snell, Edward H

    2016-07-15

    Crystallization is a key step in macromolecular structure determination by crystallography. While a robust theoretical treatment of the process is available, due to the complexity of the system, the experimental process is still largely one of trial and error. In this article, efforts in the field are discussed together with a theoretical underpinning using a solubility phase diagram. Prior knowledge has been used to develop tools that computationally predict the crystallization outcome and define mutational approaches that enhance the likelihood of crystallization. For the most part these tools are based on binary outcomes (crystal or no crystal), and the full information contained in an assembly of crystallization screening experiments is lost. The potential of this additional information is illustrated by examples where new biological knowledge can be obtained and where a target can be sub-categorized to predict which class of reagents provides the crystallization driving force. Computational analysis of crystallization requires complete and correctly formatted data. While massive crystallization screening efforts are under way, the data available from many of these studies are sparse. The potential for this data and the steps needed to realize this potential are discussed. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. X-ray diffraction peak profiles from threading dislocations in GaN epitaxial films

    OpenAIRE

    Kaganer, V M; Brandt, O.; Trampert, A.; Ploog, K. H.

    2004-01-01

    We analyze the lineshape of x-ray diffraction profiles of GaN epitaxial layers with large densities of randomly distributed threading dislocations. The peaks are Gaussian only in the central, most intense part of the peak, while the tails obey a power law. The $q^{-3}$ decay typical for random dislocations is observed in double-crystal rocking curves. The entire profile is well fitted by a restricted random dislocation distribution. The densities of both edge and screw threading dislocations ...

  15. The geomorphic structure of the runoff peak

    Directory of Open Access Journals (Sweden)

    R. Rigon

    2011-06-01

    Full Text Available This paper develops a theoretical framework to investigate the core dependence of peak flows on the geomorphic properties of river basins. Based on the theory of transport by travel times, and simple hydrodynamic characterization of floods, this new framework invokes the linearity and invariance of the hydrologic response to provide analytical and semi-analytical expressions for peak flow, time to peak, and area contributing to the peak runoff. These results are obtained for the case of constant-intensity hyetograph using the Intensity-Duration-Frequency (IDF curves to estimate extreme flow values as a function of the rainfall return period. Results show that, with constant-intensity hyetographs, the time-to-peak is greater than rainfall duration and usually shorter than the basin concentration time. Moreover, the critical storm duration is shown to be independent of rainfall return period as well as the area contributing to the flow peak. The same results are found when the effects of hydrodynamic dispersion are accounted for. Further, it is shown that, when the effects of hydrodynamic dispersion are negligible, the basin area contributing to the peak discharge does not depend on the channel velocity, but is a geomorphic propriety of the basin. As an example this framework is applied to three watersheds. In particular, the runoff peak, the critical rainfall durations and the time to peak are calculated for all links within a network to assess how they increase with basin area.

  16. [A peak recognition algorithm designed for chromatographic peaks of transformer oil].

    Science.gov (United States)

    Ou, Linjun; Cao, Jian

    2014-09-01

    In the field of the chromatographic peak identification of the transformer oil, the traditional first-order derivative requires slope threshold to achieve peak identification. In terms of its shortcomings of low automation and easy distortion, the first-order derivative method was improved by applying the moving average iterative method and the normalized analysis techniques to identify the peaks. Accurate identification of the chromatographic peaks was realized through using multiple iterations of the moving average of signal curves and square wave curves to determine the optimal value of the normalized peak identification parameters, combined with the absolute peak retention times and peak window. The experimental results show that this algorithm can accurately identify the peaks and is not sensitive to the noise, the chromatographic peak width or the peak shape changes. It has strong adaptability to meet the on-site requirements of online monitoring devices of dissolved gases in transformer oil.

  17. Crystal Dislocations

    Directory of Open Access Journals (Sweden)

    Ronald W. Armstrong

    2016-01-01

    Full Text Available Crystal dislocations were invisible until the mid-20th century although their presence had been inferred; the atomic and molecular scale dimensions had prevented earlier discovery. Now they are normally known to be just about everywhere, for example, in the softest molecularly-bonded crystals as well as within the hardest covalently-bonded diamonds. The advent of advanced techniques of atomic-scale probing has facilitated modern observations of dislocations in every crystal structure-type, particularly by X-ray diffraction topography and transmission electron microscopy. The present Special Issue provides a flavor of their ubiquitous presences, their characterizations and, especially, their influence on mechanical and electrical properties.

  18. Liquid crystal tunable photonic crystal dye laser

    DEFF Research Database (Denmark)

    Buss, Thomas; Christiansen, Mads Brøkner; Smith, Cameron

    2010-01-01

    We present a dye-doped liquid crystal laser using a photonic crystal cavity. An applied electric field to the liquid crystal provides wavelength tunability. The photonic crystal enhances resonant interaction with the gain medium.......We present a dye-doped liquid crystal laser using a photonic crystal cavity. An applied electric field to the liquid crystal provides wavelength tunability. The photonic crystal enhances resonant interaction with the gain medium....

  19. An Empirical Study on Raman Peak Fitting and Its Application to Raman Quantitative Research.

    Science.gov (United States)

    Yuan, Xueyin; Mayanovic, Robert A

    2017-10-01

    Fitting experimentally measured Raman bands with theoretical model profiles is the basic operation for numerical determination of Raman peak parameters. In order to investigate the effects of peak modeling using various algorithms on peak fitting results, the representative Raman bands of mineral crystals, glass, fluids as well as the emission lines from a fluorescent lamp, some of which were measured under ambient light whereas others under elevated pressure and temperature conditions, were fitted using Gaussian, Lorentzian, Gaussian-Lorentzian, Voigtian, Pearson type IV, and beta profiles. From the fitting results of the Raman bands investigated in this study, the fitted peak position, intensity, area and full width at half-maximum (FWHM) values of the measured Raman bands can vary significantly depending upon which peak profile function is used in the fitting, and the most appropriate fitting profile should be selected depending upon the nature of the Raman bands. Specifically, the symmetric Raman bands of mineral crystals and non-aqueous fluids are best fit using Gaussian-Lorentzian or Voigtian profiles, whereas the asymmetric Raman bands are best fit using Pearson type IV profiles. The asymmetric O-H stretching vibrations of H2O and the Raman bands of soda-lime glass are best fit using several Gaussian profiles, whereas the emission lines from a florescent light are best fit using beta profiles. Multiple peaks that are not clearly separated can be fit simultaneously, provided the residuals in the fitting of one peak will not affect the fitting of the remaining peaks to a significant degree. Once the resolution of the Raman spectrometer has been properly accounted for, our findings show that the precision in peak position and intensity can be improved significantly by fitting the measured Raman peaks with appropriate profiles. Nevertheless, significant errors in peak position and intensity were still observed in the results from fitting of weak and wide Raman

  20. Shear ordering in polymer photonic crystals.

    Science.gov (United States)

    Snoswell, D R E; Kontogeorgos, A; Baumberg, J J; Lord, T D; Mackley, M R; Spahn, P; Hellmann, G P

    2010-02-01

    Optical scattering spectra are recorded in situ on flowing colloidal polymeric nanocomposites which are sheared into photonic crystals at 150 degrees C using a high-pressure quartz-cell multipass rheometer. Broadband spectroscopy of the resonant Bragg scattering peak allows the direct observation of crystal formation and melting of monodisperse core-shell particles. A range of flow conditions of this solventless, highly viscous melt reveals four distinct regimes of crystal growth and decay which match a simple rheological model. Extraction of crystal thickness, order and lattice spacing are validated by one-dimensional electromagnetic simulations.

  1. Peak distortion effects in analytical ion chromatography.

    Science.gov (United States)

    Wahab, M Farooq; Anderson, Jordan K; Abdelrady, Mohamed; Lucy, Charles A

    2014-01-07

    The elution profile of chromatographic peaks provides fundamental understanding of the processes that occur in the mobile phase and the stationary phase. Major advances have been made in the column chemistry and suppressor technology in ion chromatography (IC) to handle a variety of sample matrices and ions. However, if the samples contain high concentrations of matrix ions, the overloaded peak elution profile is distorted. Consequently, the trace peaks shift their positions in the chromatogram in a manner that depends on the peak shape of the overloading analyte. In this work, the peak shapes in IC are examined from a fundamental perspective. Three commercial IC columns AS16, AS18, and AS23 were studied with borate, hydroxide and carbonate as suppressible eluents. Monovalent ions (chloride, bromide, and nitrate) are used as model analytes under analytical (0.1 mM) to overload conditions (10-500 mM). Both peak fronting and tailing are observed. On the basis of competitive Langmuir isotherms, if the eluent anion is more strongly retained than the analyte ion on an ion exchanger, the analyte peak is fronting. If the eluent is more weakly retained on the stationary phase, the analyte peak always tails under overload conditions regardless of the stationary phase capacity. If the charge of the analyte and eluent anions are different (e.g., Br(-) vs CO3(2-)), the analyte peak shapes depend on the eluent concentration in a more complex pattern. It was shown that there are interesting similarities with peak distortions due to strongly retained mobile phase components in other modes of liquid chromatography.

  2. PeakRanger: A cloud-enabled peak caller for ChIP-seq data

    Directory of Open Access Journals (Sweden)

    Grossman Robert

    2011-05-01

    Full Text Available Abstract Background Chromatin immunoprecipitation (ChIP, coupled with massively parallel short-read sequencing (seq is used to probe chromatin dynamics. Although there are many algorithms to call peaks from ChIP-seq datasets, most are tuned either to handle punctate sites, such as transcriptional factor binding sites, or broad regions, such as histone modification marks; few can do both. Other algorithms are limited in their configurability, performance on large data sets, and ability to distinguish closely-spaced peaks. Results In this paper, we introduce PeakRanger, a peak caller software package that works equally well on punctate and broad sites, can resolve closely-spaced peaks, has excellent performance, and is easily customized. In addition, PeakRanger can be run in a parallel cloud computing environment to obtain extremely high performance on very large data sets. We present a series of benchmarks to evaluate PeakRanger against 10 other peak callers, and demonstrate the performance of PeakRanger on both real and synthetic data sets. We also present real world usages of PeakRanger, including peak-calling in the modENCODE project. Conclusions Compared to other peak callers tested, PeakRanger offers improved resolution in distinguishing extremely closely-spaced peaks. PeakRanger has above-average spatial accuracy in terms of identifying the precise location of binding events. PeakRanger also has excellent sensitivity and specificity in all benchmarks evaluated. In addition, PeakRanger offers significant improvements in run time when running on a single processor system, and very marked improvements when allowed to take advantage of the MapReduce parallel environment offered by a cloud computing resource. PeakRanger can be downloaded at the official site of modENCODE project: http://www.modencode.org/software/ranger/

  3. Liquid Crystals

    Science.gov (United States)

    1990-01-01

    Thermochromic liquid crystals, or TLCs, are a type of liquid crystals that react to changes in temperature by changing color. The Hallcrest/NASA collaboration involved development of a new way to visualize boundary layer transition in flight and in wind tunnel testing of aircraft wing and body surfaces. TLCs offered a new and potentially better method of visualizing the boundary layer transition in flight. Hallcrest provided a liquid crystal formulation technique that afforded great control over the sensitivity of the liquid crystals to varying conditions. Method is of great use to industry, government and universities for aerodynamic and hydrodynamic testing. Company's principal line is temperature indicating devices for industrial use, such as non-destructive testing and flaw detection in electric/electronic systems, medical application, such as diagnostic systems, for retail sale, such as room, refrigerator, baby bath and aquarium thermometers, and for advertising and promotion specials. Additionally, Hallcrest manufactures TLC mixtures for cosmetic applications, and liquid crystal battery tester for Duracell batteries.

  4. Parity violation and parity conservation in unstirred crystallization: Effect of first crystals

    Energy Technology Data Exchange (ETDEWEB)

    Szurgot, M. [Center of Mathematics and Physics, Technical University of Lodz (Poland)

    2012-02-15

    Statistics of nucleation of chiral forms was studied to establish the effect of the number of first crystals and their handedness on distributions of enantiomers. Various bimodal, trimodal and unimodal distributions are obtained in unstirred crystallization, depending on the number of initial crystals and growth conditions. The binomial distribution satisfactorily describes experimental distributions of enantiomeric excess and may be used to predict distributions and probabilities of nucleation of enantiomers. The first nucleated crystals determine the handedness of secondary crystals, and number of initial crystals governs statistics of chiral nucleation. According to the binomial distribution if single crystals nucleate as the first, the bimodal distributions result with D and L peaks. If LD, LL, and DD pairs are nucleated as first, trimodal distributions with D, R, and L peaks are created, and if groups of crystals of various handedness nucleate as the first the unimodal distributions of enantiomeric excess with racemate R peaks are formed. Chiral nucleation experiments on sodium bromate were the basis for the theoretical considerations and verifications of predictions resulting from binomial distributions on probabilities of the creation of L and D crystals, and racemates, and the presence of D, L, and R peaks in the distributions. Growth conditions affect the number of the first crystals and effectiveness of cloning, and as a result, the distributions of enantiomers. Formation of pure enantiomers and/or racemates proves that the conservation of chiral symmetry, and the breakage of chiral symmetry can occur in unstirred crystallization. (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  5. Bayesian Peak Picking for NMR Spectra

    Directory of Open Access Journals (Sweden)

    Yichen Cheng

    2014-02-01

    Full Text Available Protein structure determination is a very important topic in structural genomics, which helps people to understand varieties of biological functions such as protein-protein interactions, protein–DNA interactions and so on. Nowadays, nuclear magnetic resonance (NMR has often been used to determine the three-dimensional structures of protein in vivo. This study aims to automate the peak picking step, the most important and tricky step in NMR structure determination. We propose to model the NMR spectrum by a mixture of bivariate Gaussian densities and use the stochastic approximation Monte Carlo algorithm as the computational tool to solve the problem. Under the Bayesian framework, the peak picking problem is casted as a variable selection problem. The proposed method can automatically distinguish true peaks from false ones without preprocessing the data. To the best of our knowledge, this is the first effort in the literature that tackles the peak picking problem for NMR spectrum data using Bayesian method.

  6. Tectonics, Climate and Earth's highest peaks

    Science.gov (United States)

    Robl, Jörg; Prasicek, Günther; Hergarten, Stefan

    2016-04-01

    Prominent peaks characterized by high relief and steep slopes are among the most spectacular morphological features on Earth. In collisional orogens they result from the interplay of tectonically driven crustal thickening and climatically induced destruction of overthickened crust by erosional surface processes. The glacial buzz-saw hypothesis proposes a superior status of climate in limiting mountain relief and peak altitude due to glacial erosion. It implies that peak altitude declines with duration of glacial occupation, i.e., towards high latitudes. This is in strong contrast with high peaks existing in high latitude mountain ranges (e.g. Mt. St. Elias range) and the idea of peak uplift due to isostatic compensation of spatially variable erosional unloading an over-thickened orogenic crust. In this study we investigate landscape dissection, crustal thickness and vertical strain rates in tectonically active mountain ranges to evaluate the influence of erosion on (latitudinal) variations in peak altitude. We analyze the spatial distribution of serval thousand prominent peaks on Earth extracted from the global ETOPO1 digital elevation model with a novel numerical tool. We compare this dataset to crustal thickness, thickening rate (vertical strain rate) and mean elevation. We use the ratios of mean elevation to peak elevation (landscape dissection) and peak elevation to crustal thickness (long-term impact of erosion on crustal thickness) as indicators for the influence of erosional surface processes on peak uplift and the vertical strain rate as a proxy for the mechanical state of the orogen. Our analysis reveals that crustal thickness and peak elevation correlate well in orogens that have reached a mechanically limited state (vertical strain rate near zero) where plate convergence is already balanced by lateral extrusion and gravitational collapse and plateaus are formed. On the Tibetan Plateau crustal thickness serves to predict peak elevation up to an altitude

  7. Peak Vegetation Growth 1993 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 1993 peak vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the map...

  8. Peak Vegetation Growth 1995 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 1995 peak vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the map...

  9. Peak Vegetation Growth 2004 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 2004 peak vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the map...

  10. Peak Vegetation Growth 1991 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 1991 peak vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the map...

  11. Peak Vegetation Growth 1998 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 1998 peak vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the map...

  12. Peak Vegetation Growth 1997 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 1997 peak vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the map...

  13. Peak Vegetation Growth 2000 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 2000 peak vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the map...

  14. Peak Vegetation Growth 2003 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 2003 peak vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the map...

  15. Peak Vegetation Growth 2005 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 2005 peak vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the map...

  16. Bayesian Peak Picking for NMR Spectra

    KAUST Repository

    Cheng, Yichen

    2014-02-01

    Protein structure determination is a very important topic in structural genomics, which helps people to understand varieties of biological functions such as protein-protein interactions, protein–DNA interactions and so on. Nowadays, nuclear magnetic resonance (NMR) has often been used to determine the three-dimensional structures of protein in vivo. This study aims to automate the peak picking step, the most important and tricky step in NMR structure determination. We propose to model the NMR spectrum by a mixture of bivariate Gaussian densities and use the stochastic approximation Monte Carlo algorithm as the computational tool to solve the problem. Under the Bayesian framework, the peak picking problem is casted as a variable selection problem. The proposed method can automatically distinguish true peaks from false ones without preprocessing the data. To the best of our knowledge, this is the first effort in the literature that tackles the peak picking problem for NMR spectrum data using Bayesian method.

  17. Amplification of postwildfire peak flow by debris

    Science.gov (United States)

    Kean, Jason W.; McGuire, Luke; Rengers, Francis; Smith, Joel B.; Staley, Dennis M.

    2016-01-01

    In burned steeplands, the peak depth and discharge of postwildfire runoff can substantially increase from the addition of debris. Yet methods to estimate the increase over water flow are lacking. We quantified the potential amplification of peak stage and discharge using video observations of postwildfire runoff, compiled data on postwildfire peak flow (Qp), and a physically based model. Comparison of flood and debris flow data with similar distributions in drainage area (A) and rainfall intensity (I) showed that the median runoff coefficient (C = Qp/AI) of debris flows is 50 times greater than that of floods. The striking increase in Qp can be explained using a fully predictive model that describes the additional flow resistance caused by the emergence of coarse-grained surge fronts. The model provides estimates of the amplification of peak depth, discharge, and shear stress needed for assessing postwildfire hazards and constraining models of bedrock incision.

  18. Global Earthquake Hazard Distribution - Peak Ground Acceleration

    Data.gov (United States)

    National Aeronautics and Space Administration — Global Earthquake Hazard Distribution-peak ground acceleration is a 2.5 minute grid of global earthquake hazards developed using Global Seismic Hazard Program...

  19. Global Earthquake Hazard Distribution - Peak Ground Acceleration

    Data.gov (United States)

    National Aeronautics and Space Administration — Global Earthquake Hazard Distribution-Peak Ground Acceleration is a 2.5 by 2.5 minute grid of global earthquake hazards developed using Global Seismic Hazard Program...

  20. Fewer peak trials per session facilitate acquisition of peak responding despite elimination of response rate differences.

    Science.gov (United States)

    Kaiser, Daren H

    2009-01-01

    It has been shown in previous research [Kaiser, D.H., 2008. The proportion of fixed interval trials to probe trials affects acquisition of the peak procedure fixed interval timing task. Behav. Process., 77 (1), 100-108] that rats acquired peak responding sooner when fewer peak trials were presented during sessions of training with the peak procedure timing task. One potential problem with that research was that there were large differences in response rates among the groups. The present experiment attempted to examine the effect of proportion of peak trials when differences in response rate were controlled. Two groups of rats were each simultaneously tested with two versions of the peak procedure. One group was tested with 10% peak trials per session, and the other group was tested with 50% peak trials per session. For both of the groups, one of the panel lights and levers was associated with the traditional peak procedure. The other panel light and lever was associated with a similar peak procedure; however, reinforcement was provided at the end of each peak trial. This manipulation eliminated differences in response rate among the groups, however, Group 10% acquired peak responding more quickly than Group 50%, effectively replicating previous work in the absence of a response bias.

  1. Improved peak shape fitting in alpha spectra

    OpenAIRE

    POMME Stefaan; CARO MARROYO BELEN

    2014-01-01

    Peak overlap is a recurrent issue ina lpha-particle spectrometry, not only in routine analyses but also in the high-resolution spectra from which reference values for alpha emission probabilities are derived. In this work, improved peak shape formulae are presented for the deconvolution of alpha-particle spectra. They have been implemented as fit functions in a spreadsheet application and optimum fit parameters were searched with built-in optimisation routines. Deconvolution results are shown...

  2. Predicting Peak Flows following Forest Fires

    Science.gov (United States)

    Elliot, William J.; Miller, Mary Ellen; Dobre, Mariana

    2016-04-01

    Following forest fires, peak flows in perennial and ephemeral streams often increase by a factor of 10 or more. This increase in peak flow rate may overwhelm existing downstream structures, such as road culverts, causing serious damage to road fills at stream crossings. In order to predict peak flow rates following wildfires, we have applied two different tools. One is based on the U.S.D.A Natural Resource Conservation Service Curve Number Method (CN), and the other is by applying the Water Erosion Prediction Project (WEPP) to the watershed. In our presentation, we will describe the science behind the two methods, and present the main variables for each model. We will then provide an example of a comparison of the two methods to a fire-prone watershed upstream of the City of Flagstaff, Arizona, USA, where a fire spread model was applied for current fuel loads, and for likely fuel loads following a fuel reduction treatment. When applying the curve number method, determining the time to peak flow can be problematic for low severity fires because the runoff flow paths are both surface and through shallow lateral flow. The WEPP watershed version incorporates shallow lateral flow into stream channels. However, the version of the WEPP model that was used for this study did not have channel routing capabilities, but rather relied on regression relationships to estimate peak flows from individual hillslope polygon peak runoff rates. We found that the two methods gave similar results if applied correctly, with the WEPP predictions somewhat greater than the CN predictions. Later releases of the WEPP model have incorporated alternative methods for routing peak flows that need to be evaluated.

  3. Harmonic generation at high peak power

    Energy Technology Data Exchange (ETDEWEB)

    Summers, M.A.; Williams, J.D.; Johnson, B.C.; Eimerl, D.

    1985-12-13

    This report reviews progress made in recent years in frequency conversion of laser radiation. By using a material such as potassium dihydrogen phosphate (KDP), intense, coherent light is made available at wavelengths unavailable from the source laser medium. Tests were performed on an array of KDP crystals at the Nova Facility. The tests revealed unexpected losses due to various non-linear effects. (JDH)

  4. Thermal conductivity of ferrimagnet GdBaMn2O5.0 single crystals

    Directory of Open Access Journals (Sweden)

    J. C. Wu

    2017-05-01

    Full Text Available GdBaMn2O5.0 is a double-perovskite ferrimagnet consisting of pyramidal manganese layers. In this work, we study the in-plane and the c-axis thermal conductivities of GdBaMn2O5.0 single crystals at low temperatures down to 0.3 K and in high magnetic fields up to 14 T. The κc(T curve shows a broad hump below the Néel temperature (TN = 144 K, which indicates the magnon heat transport along the c axis. Whereas, the κa(T shows a kink at TN, caused by a magnon-phonon scattering effect. This anisotropic behavior is caused by the anisotropy of spin interactions along different directions. At very low temperatures, magnetic-field-induced changes of κa and κc, which is likely due to phonon scattering by free Gd3+ spins, is rather weak. This indicates that the spin coupling between Gd3+ and Mn2+/Mn3+ is rather strong at low temperatures.

  5. How to use your peak flow meter

    Science.gov (United States)

    ... discharge COPD - control drugs COPD - quick-relief drugs COPD - what to ask your doctor Exercise-induced asthma Exercising and asthma at school Make peak flow a habit! Signs of an asthma attack Stay away from asthma triggers Review Date 2/15/2016 Updated by: Neil K. ...

  6. Some Phenomenological Aspects of the Peak Experience

    Science.gov (United States)

    Rosenblatt, Howard S.; Bartlett, Iris

    1976-01-01

    This article relates the psychological dynamics of "peak experiences" to two concepts, intentionality and paradoxical intention, within the philosophical orientation of phenomenology. A review of early philosophical theories of self (Kant and Hume) is presented and compared with the experiential emphasis found in the phenomenology of Husserl.…

  7. Restored thermoluminescence in oxide crystals

    Energy Technology Data Exchange (ETDEWEB)

    Rakov, A.F., E-mail: afrakov@hotmail.co [Institute of Nuclear Physics, Uzbek Academy of Sciences, Tashkent, 700132 (Uzbekistan); Salikhbaev, U.S.; Islamov, A.K. [Institute of Nuclear Physics, Uzbek Academy of Sciences, Tashkent, 700132 (Uzbekistan); Bartram, R.H. [Department of Physics, University of Connecticut, Storrs, CT 06269-3046 (United States); Melcher, C.L. [Scintillation Materials Research Center, University of Tennessee, Knoxville, TN 37996-2000 (United States)

    2010-11-15

    In this paper, we present the results of a thermoluminescence study on several oxide crystals, including Y{sub 3}Al{sub 5}O{sub 12} (YAG), Y{sub 3}Al{sub 5}O{sub 12}:Nd (YAG:Nd), Lu{sub 2}SiO{sub 5}:Ce (LSO:Ce), Y{sub 2}SiO{sub 5}:Ce (YSO:Ce), Gd{sub 2}SiO{sub 5}:Ce (GSO:Ce), PbWO (PWO), and PbWO:La (PWO:La). A phenomenon involving restoration of thermoluminescence (TL) glow peaks is found to occur in some of the crystals investigated; crystals {gamma}-irradiated at room temperature and subsequently stored for some time in the dark at 77 K exhibit TL glow peaks in the range below room temperature. This phenomenon is caused not by a thermally or optically stimulated process, but rather as a by-product of a tunneling process. The intensity of the restored TL glow peaks measured in LSO:Ce crystals is found to be proportional both to the radiation dose and to the storage-time at low temperature. A phenomenological theoretical model is proposed, in which tunneling recombination occurs between deep electron and hole traps accompanied by the simultaneous ejection of an electron to the conduction band; some of these conduction electrons then repopulate shallow traps. An oxygen vacancy with two trapped electrons is assumed to be the deep electron trap in this model. The role of oxygen vacancies is confirmed by heating in air at 1000 {sup o}C. This model is applied specifically to LSO:Ce, and several possible candidates are suggested for shallow traps in that material.

  8. Effect of gear ratio on peak power and time to peak power in BMX cyclists.

    Science.gov (United States)

    Rylands, Lee P; Roberts, Simon J; Hurst, Howard T

    2017-03-01

    The aim of this study was to ascertain if gear ratio selection would have an effect on peak power and time to peak power production in elite Bicycle Motocross (BMX) cyclists. Eight male elite BMX riders volunteered for the study. Each rider performed three, 10-s maximal sprints on an Olympic standard indoor BMX track. The riders' bicycles were fitted with a portable SRM power meter. Each rider performed the three sprints using gear ratios of 41/16, 43/16 and 45/16 tooth. The results from the 41/16 and 45/16 gear ratios were compared to the current standard 43/16 gear ratio. Statistically, significant differences were found between the gear ratios for peak power (F(2,14) = 6.448; p = .010) and peak torque (F(2,14) = 4.777; p = .026), but no significant difference was found for time to peak power (F(2,14) = 0.200; p = .821). When comparing gear ratios, the results showed a 45/16 gear ratio elicited the highest peak power,1658 ± 221 W, compared to 1436 ± 129 W and 1380 ± 56 W, for the 43/16 and 41/16 ratios, respectively. The time to peak power showed a 41/16 tooth gear ratio attained peak power in -0.01 s and a 45/16 in 0.22 s compared to the 43/16. The findings of this study suggest that gear ratio choice has a significant effect on peak power production, though time to peak power output is not significantly affected. Therefore, selecting a higher gear ratio results in riders attaining higher power outputs without reducing their start time.

  9. Improved peak shape fitting in alpha spectra.

    Science.gov (United States)

    Pommé, S; Caro Marroyo, B

    2015-02-01

    Peak overlap is a recurrent issue in alpha-particle spectrometry, not only in routine analyses but also in the high-resolution spectra from which reference values for alpha emission probabilities are derived. In this work, improved peak shape formulae are presented for the deconvolution of alpha-particle spectra. They have been implemented as fit functions in a spreadsheet application and optimum fit parameters were searched with built-in optimisation routines. Deconvolution results are shown for a few challenging spectra with high statistical precision. The algorithm outperforms the best available routines for high-resolution spectrometry, which may facilitate a more reliable determination of alpha emission probabilities in the future. It is also applicable to alpha spectra with inferior energy resolution. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  10. Peak oil, food systems, and public health.

    Science.gov (United States)

    Neff, Roni A; Parker, Cindy L; Kirschenmann, Frederick L; Tinch, Jennifer; Lawrence, Robert S

    2011-09-01

    Peak oil is the phenomenon whereby global oil supplies will peak, then decline, with extraction growing increasingly costly. Today's globalized industrial food system depends on oil for fueling farm machinery, producing pesticides, and transporting goods. Biofuels production links oil prices to food prices. We examined food system vulnerability to rising oil prices and the public health consequences. In the short term, high food prices harm food security and equity. Over time, high prices will force the entire food system to adapt. Strong preparation and advance investment may mitigate the extent of dislocation and hunger. Certain social and policy changes could smooth adaptation; public health has an essential role in promoting a proactive, smart, and equitable transition that increases resilience and enables adequate food for all.

  11. Electrochromic blueshift in polymer-dispersed liquid-crystal cells.

    Science.gov (United States)

    Ramsey, R A; Sharma, S C

    2004-10-01

    Electrochromic blueshift in the absorption band of polymer-dispersed liquid-crystal cells is reported as a function of applied electric field. The changes in the peak absorption wavelength, absorption broadening, and their possible relationships with the nonlinear optical properties of polymer-dispersed liquid-crystal cells are discussed.

  12. Ten Reasons to Take Peak Oil Seriously

    Directory of Open Access Journals (Sweden)

    Robert J. Brecha

    2013-02-01

    Full Text Available Forty years ago, the results of modeling, as presented in The Limits to Growth, reinvigorated a discussion about exponentially growing consumption of natural resources, ranging from metals to fossil fuels to atmospheric capacity, and how such consumption could not continue far into the future. Fifteen years earlier, M. King Hubbert had made the projection that petroleum production in the continental United States would likely reach a maximum around 1970, followed by a world production maximum a few decades later. The debate about “peak oil”, as it has come to be called, is accompanied by some of the same vociferous denials, myths and ideological polemicizing that have surrounded later representations of The Limits to Growth. In this review, we present several lines of evidence as to why arguments for a near-term peak in world conventional oil production should be taken seriously—both in the sense that there is strong evidence for peak oil and in the sense that being societally unprepared for declining oil production will have serious consequences.

  13. Revisiting Twomey's approximation for peak supersaturation

    Directory of Open Access Journals (Sweden)

    B. J. Shipway

    2015-04-01

    Full Text Available Twomey's seminal 1959 paper provided lower and upper bound approximations to the estimation of peak supersaturation within an updraft and thus provides the first closed expression for the number of nucleated cloud droplets. The form of this approximation is simple, but provides a surprisingly good estimate and has subsequently been employed in more sophisticated treatments of nucleation parametrization. In the current paper, we revisit the lower bound approximation of Twomey and make a small adjustment that can be used to obtain a more accurate calculation of peak supersaturation under all potential aerosol loadings and thermodynamic conditions. In order to make full use of this improved approximation, the underlying integro-differential equation for supersaturation evolution and the condition for calculating peak supersaturation are examined. A simple rearrangement of the algebra allows for an expression to be written down that can then be solved with a single lookup table with only one independent variable for an underlying lognormal aerosol population. While multimodal aerosol with N different dispersion characteristics requires 2N+1 inputs to calculate the activation fraction, only N of these one-dimensional lookup tables are needed. No additional information is required in the lookup table to deal with additional chemical, physical or thermodynamic properties. The resulting implementation provides a relatively simple, yet computationally cheap, physically based parametrization of droplet nucleation for use in climate and Numerical Weather Prediction models.

  14. The Hong Kong Peak Tram Illusion

    Directory of Open Access Journals (Sweden)

    Ping-Hui Chiu

    2011-05-01

    Full Text Available Hong Kong Peak Tram Illusion is the perceived slant of buildings towards the peak away from the vertical while observers travel on the Hong Kong peak tram. We measured the perceived tilt of the buildings from true vertical (illusion size using a rotary pitch while an identical pitch read the slope of the hill. The illusion was hypothesized to be jointly determined by at least four factors: (i the reclining position of the observer, (ii the frame of the tram window, (iii the direction of motion, and (iv additional reference cues from outside the window. Our results showed that the illusion: (i was reduced by up to 20% when observers sat with a wedge on their back and up to 40% when they stood up. (ii remained even when observers moved closer to the window to avoid the effect of the frame. (iii was 20% larger when the tram was descending, as opposed to ascending. (iv was less apparent during the day. The illusion appears to be due to integration of the above sensory information as it cannot be accounted for by each factor alone. The illusion provides a unique venue to study cross-modal sensory interaction in the nature setting.

  15. The improved scintillation crystal lead tungstate scintillation for PET

    Science.gov (United States)

    Wan, Youbao; WU, Rurong; Xiao, Linrong; Zhang, Jianxin; Yang, Peizhi; Yan, Hui

    2009-07-01

    As a valuable material for the detecting of γ-ray, PbWO4 and BaF2:PbWO4 crystals were grown by a novel multi-crucible temperature gradient system developed by ourselves. Utilizing a topical partial heating method, this system can form a topical partial high temperature in its hearth. Thus this system could melt raw materials in step by step as requirement. The advantage of this method is that there would be solid obstruct left on the melt in the procedure of the crystal growing up. The left obstruct could prevent the volatilization of the component in the melt. Hence it is helpful for the composition homogenization in the crystal. The system also offers a sustaining device for multi-crucibles and thus it can grow many crystals simultaneity. The optical properties and scintillation properties of the crystals were studied. The results reveal that the ions doping improves the scintillation properties of the crystal. The transmittance spectra show that the transmittance of BaF2:PbWO4 crystals are better than that of PbWO4 crystals. For the PbWO4 crystals, their absorption edge is at 325nm, and their maximum transmittance is 68%. For the BaF2:PbWO4 crystals, their absorption edge is at 325nm and their maximum transmittance is upto76%. The X-ray excited luminescence spectra shows that the luminescence peak is at 420nm for the samples of PbWO4 crystal while the peak is at 430nm for the samples of BaF2:PbWO4 crystal respectively. The luminescence intensity of the samples of BaF2:PbWO4 crystal is about two times than that of PbWO4 crystal. And their peak shape is different for the two kind of crystal. The light yield of BaF2:PbWO4 crystals is about 2.9 times than that of PbWO4 crystal Analyzing these scintillation properties, we find that the VPb 3+ and VO- defects do harm for the optical properties of the crystal. Ions doping method could reduce the defect concentration and improving its illumination performance of the crystal. Specially, the doped F- ions in O2- site can

  16. Improving EEG signal peak detection using feature weight learning ...

    Indian Academy of Sciences (India)

    Asrul Adam

    the combination of eye gaze and EEG for brain–machine interfacing have ... first and second half waves, peak width, ascending peak slope of the ... half wave. Acir et al [1] introduced an additional feature of peak amplitude, defined as the peak-to-peak amplitude of the second half wave, and also two addition features of the.

  17. Antiferromagnetism in chromium alloy single crystals

    DEFF Research Database (Denmark)

    Bjerrum Møller, Hans; Trego, A.L.; Mackintosh, A.R.

    1965-01-01

    The antiferromagnetism of single crystals of dilute alloys of V, Mn and Re in Cr has been studied at 95°K and 300°K by neutron diffraction. The addition of V causes the diffraction peaks to decrease in intensity and move away from (100), while Mn and Re cause them to increase and approach (100) s...

  18. Gamma-Ray Burst Formation Rate Inferred from the Spectral Peak EnergyndashPeak Luminosity Relation

    OpenAIRE

    Yonetoku, D.; Murakami, T.; Nakamura, T.; Yamazaki, Ryo; Inoue, A.K.; Ioka, K.

    2004-01-01

    We estimate a gamma-ray burst (GRB) formation rate based on the new relation between the spectral peak energy (Ep) and the peak luminosity. The new relation is derived by combining the data of Ep and the peak luminosities by BeppoSAX and BATSE, and it looks considerably tighter and more reliable than the relations suggested by the previous works. Using the new Ep-luminosity relation, we estimate redshifts of the 689 GRBs without known distances in the BATSE catalog and derive a GRB formation ...

  19. Angular correlation of annihilation photons in ice single crystals

    DEFF Research Database (Denmark)

    Mogensen, O. E.; Kvajic, G.; Eldrup, Morten Mostgaard

    1971-01-01

    Linear-slit angular-correlation curves were obtained at - 148 °C for the [0001], [10¯10], and [11¯20] directions in single crystals of ice. Besides the narrow central peak, pronounced narrow side peaks were also observed. They occurred at angles θ=2πℏgz/mc, where gz is the projection of reciproca...

  20. Crystallization kinetics of Fe based amorphous alloy

    Science.gov (United States)

    Shanker Rao, T.; Lilly Shanker Rao, T.

    2015-02-01

    Differential Scanning Calorimetry(DSC) experimental data under non-isothermal conditions for Fe based Metglas 2605SA1 (wt% Fe=85-95, Si=5-10, B=1-5) metallic glass ribbons are reported and discussed. The DSC Scans performed at different heating rates showed two step crystallization processes and are interpreted in terms of different models like Kissinger, Ozawa, Boswell, Augis & Bennett and Gao & Wang. From the heating rate dependence of the onset temperature (To) and the crystallization peak temperature (Tp), the kinetic triplet, activation energy of crystallization (E), Avrami exponent (n) and the frequency factor (A) are determined. The determined E for peak I is 354.5 ± 2.5 kJ/mol and for the peak II is 348.2 ± 2.2 kJ/mol, respectively. The frequency factor for peak I is 1.1 × 1023sec-1 and for peak II is 6.1 × 1020sec-1.

  1. Ratio of peak height to peak area as selection criterion for solid standards in soil analysis

    Energy Technology Data Exchange (ETDEWEB)

    Gerwinski, W.

    1985-12-01

    The shapes of extinction curves in atomic absorption spectroscopy with direct analysis of solid samples show remarkable differences between different types of samples. The influence of matrix components on this phenomenon has been investigated. The precision of analytical results performed with the aid of reference materials and preceded by calibration with both liquid and solid standards has been compared. Furthermore, the correlation between the precision of analytical results and the ratio of peak height to peak area has been investigated.

  2. LARAMIE PEAK WILDERNESS STUDY AREA, WYOMING.

    Science.gov (United States)

    Segerstrom, Kenneth; Weisner, R.C.

    1984-01-01

    On the basis of a mineral survey, most of the Laramie Peak Wilderness study area in Wyoming was concluded to have little promise for the occurrence of mineral or energy resources. Only three small areas in the northern part, one extending outside the study area to Esterbrook, were found to have probable mineral-resource potential for copper and lead. The geologic setting precludes the presence of fossil-fuel resources in the study area. There are no surface indications that geothermal energy could be developed within or near the study area.

  3. Particle creation by peak electric field

    Energy Technology Data Exchange (ETDEWEB)

    Adorno, T.C. [Tomsk State University, Department of Physics, Tomsk (Russian Federation); Gavrilov, S.P. [Tomsk State University, Department of Physics, Tomsk (Russian Federation); Herzen State Pedagogical University of Russia, Department of General and Experimental Physics, St. Petersburg (Russian Federation); Gitman, D.M. [Tomsk State University, Department of Physics, Tomsk (Russian Federation); P. N. Lebedev Physical Institute, Moscow (Russian Federation); University of Sao Paulo, Institute of Physics, CP 66318, Sao Paulo, SP (Brazil)

    2016-08-15

    The particle creation by the so-called peak electric field is considered. The latter field is a combination of two exponential parts, one exponentially increasing and another exponentially decreasing. We find exact solutions of the Dirac equation with the field under consideration with appropriate asymptotic conditions and calculate all the characteristics of particle creation effect, in particular, differential mean numbers of created particle, total number of created particles, and the probability for a vacuum to remain a vacuum. Characteristic asymptotic regimes are discussed in detail and a comparison with the pure asymptotically decaying field is considered. (orig.)

  4. Energy peaks: A high energy physics outlook

    Science.gov (United States)

    Franceschini, Roberto

    2017-12-01

    Energy distributions of decay products carry information on the kinematics of the decay in ways that are at the same time straightforward and quite hidden. I will review these properties and discuss their early historical applications, as well as more recent ones in the context of (i) methods for the measurement of masses of new physics particle with semi-invisible decays, (ii) the characterization of Dark Matter particles produced at colliders, (iii) precision mass measurements of Standard Model particles, in particular of the top quark. Finally, I will give an outlook of further developments and applications of energy peak method for high energy physics at colliders and beyond.

  5. Crystallization process

    Science.gov (United States)

    Adler, Robert J.; Brown, William R.; Auyang, Lun; Liu, Yin-Chang; Cook, W. Jeffrey

    1986-01-01

    An improved crystallization process is disclosed for separating a crystallizable material and an excluded material which is at least partially excluded from the solid phase of the crystallizable material obtained upon freezing a liquid phase of the materials. The solid phase is more dense than the liquid phase, and it is separated therefrom by relative movement with the formation of a packed bed of solid phase. The packed bed is continuously formed adjacent its lower end and passed from the liquid phase into a countercurrent flow of backwash liquid. The packed bed extends through the level of the backwash liquid to provide a drained bed of solid phase adjacent its upper end which is melted by a condensing vapor.

  6. Outreach Plans for Storm Peak Laboratory

    Science.gov (United States)

    Hallar, A. G.; McCubbin, I. B.

    2006-12-01

    The Desert Research Institute (DRI) operates a high elevation facility, Storm Peak Laboratory (SPL), located on the west summit of Mt. Werner in the Park Range near Steamboat Springs, Colorado at an elevation 10,500 ft. SPL provides an ideal location for long-term research on the interactions of atmospheric aerosol and gas- phase chemistry with cloud and natural radiation environments. SPL includes an office-type laboratory room for computer and instrumentation setup with outside air ports and cable access to the roof deck, a full kitchen and two bunk rooms with sleeping space for nine persons. We plan to create a unique summer undergraduate education experiences for students of diversity at Storm Peak Laboratory. As stressed by the College Pathways to Science Education Standards [Siebert and McIntosh, 2001], to support changes in K-12 science education transformations must first be made at the college level, including inquiry-oriented opportunities to engage in meaningful research. These workshops will be designed to allow students to experience the excitement of science, increasing their likelihood of pursing careers within the fields of scientific education or research.

  7. NITPICK: peak identification for mass spectrometry data

    Directory of Open Access Journals (Sweden)

    Steen Hanno

    2008-08-01

    Full Text Available Abstract Background The reliable extraction of features from mass spectra is a fundamental step in the automated analysis of proteomic mass spectrometry (MS experiments. Results This contribution proposes a sparse template regression approach to peak picking called NITPICK. NITPICK is a Non-greedy, Iterative Template-based peak PICKer that deconvolves complex overlapping isotope distributions in multicomponent mass spectra. NITPICK is based on fractional averagine, a novel extension to Senko's well-known averagine model, and on a modified version of sparse, non-negative least angle regression, for which a suitable, statistically motivated early stopping criterion has been derived. The strength of NITPICK is the deconvolution of overlapping mixture mass spectra. Conclusion Extensive comparative evaluation has been carried out and results are provided for simulated and real-world data sets. NITPICK outperforms pepex, to date the only alternate, publicly available, non-greedy feature extraction routine. NITPICK is available as software package for the R programming language and can be downloaded from http://hci.iwr.uni-heidelberg.de/mip/proteomics/.

  8. Peak heart rates at extreme altitudes

    DEFF Research Database (Denmark)

    Lundby, C; Van Hall, Gerrit

    2001-01-01

    We have measured maximal heart rate during a graded maximal bicycle exercise test to exhaustion in five healthy climbers before and during an expedition to Mt. Everest. Maximal heart rates at sea level were 186 (177-204) beats/min(-1) at sea level and 170 (169-182) beats/min(-1) with acute hypoxia....... After 1, 4 and 6 weeks of acclimatization to 5400 m, maximal heart rates were 155 (135-182), 158 (144-182), and 155 (140-183) beats/min(-1), respectively. Heart rates of two of the climbers were measured during their attempt to reach the summit of Mt. Everest without the use of supplemental oxygen....... The peak heart rates at 8,750 m for the two climbers were 142 and 144 beats/min(-1), which were similar to their maximal heart rates during exhaustive bicycle exercise at 5,400 m, the values being 144 and 148 beats/min(-1), respectively. The peak heart rates at 8,750 m are in agreement with other field...

  9. , Recorded at Ladron Peak, Central New Mexico

    Science.gov (United States)

    Ricketts, J. W.; Kelley, S.; Read, A. S.; Karlstrom, K. E.

    2010-12-01

    Ladron Peak, situated on the western flank of the Rio Grande rift ~30 miles NW of Socorro, NM, is composed of Precambrian granitic and metamorphic assemblages that have been faulted and uplifted during the late Tertiary formation of the rift. The area is bounded on three sides by normal faults, including the anomalously low-angle (~26°) Jeter fault to the east, which places Precambrian rocks in the footwall against Paleozoic and Mesozoic fault slivers, and mainly Cenozoic Santa Fe Group basin fill in the hanging wall. New apatite fission track (AFT) thermochronological data collected at 22 locations along the NE and SE margins of Ladron Peak give a range of ages from 10.9 ± 1.9 to 20.4 ± 8.6 Ma. Samples within the footwall include granitic and metasedimentary rocks that have mean track lengths of 13.1 to 14.1 μm; one quartzite sample has a mean track length of 12.5 μm, suggesting time in the partial annealing zone. Within the hanging wall block, new AFT ages from the Permian Bursum and Abo Formations give cooling ages of 23.1 ± 3.3 Ma. and 59.9 ± 12.4 Ma., respectively. The Bursum Formation sample, with a track length of 13.7 μm, cooled below the 110°C isotherm during the Miocene, while the Abo Formation sample, with a track length of 11.2 μm, was only partially reset prior to rift-related deformation. Mylonitized granitic and metamorphic rocks in the immediate footwall preserve dip-slip lineations that are parallel to slip on the Jeter fault. This suggests that strain associated with exhumation was recorded by both brittle and ductile deformation. Although this type of deformation is common within metamorphic core complexes in highly extended terranes, ductile normal faulting has not been recognized within the Rio Grande rift in New Mexico, though there is some suggestion of ductile deformation around Blanca Peak in the San Luis Valley in Colorado. These observations imply one or both of the following: (1) Ductile deformation at Ladron Peak was

  10. Peak Wind Tool for General Forecasting

    Science.gov (United States)

    Barrett, Joe H., III

    2010-01-01

    The expected peak wind speed of the day is an important forecast element in the 45th Weather Squadron's (45 WS) daily 24-Hour and Weekly Planning Forecasts. The forecasts are used for ground and space launch operations at the Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS). The 45 WS also issues wind advisories for KSC/CCAFS when they expect wind gusts to meet or exceed 25 kt, 35 kt and 50 kt thresholds at any level from the surface to 300 ft. The 45 WS forecasters have indicated peak wind speeds are challenging to forecast, particularly in the cool season months of October - April. In Phase I of this task, the Applied Meteorology Unit (AMU) developed a tool to help the 45 WS forecast non-convective winds at KSC/CCAFS for the 24-hour period of 0800 to 0800 local time. The tool was delivered as a Microsoft Excel graphical user interface (GUI). The GUI displayed the forecast of peak wind speed, 5-minute average wind speed at the time of the peak wind, timing of the peak wind and probability the peak speed would meet or exceed 25 kt, 35 kt and 50 kt. For the current task (Phase II ), the 45 WS requested additional observations be used for the creation of the forecast equations by expanding the period of record (POR). Additional parameters were evaluated as predictors, including wind speeds between 500 ft and 3000 ft, static stability classification, Bulk Richardson Number, mixing depth, vertical wind shear, temperature inversion strength and depth and wind direction. Using a verification data set, the AMU compared the performance of the Phase I and II prediction methods. Just as in Phase I, the tool was delivered as a Microsoft Excel GUI. The 45 WS requested the tool also be available in the Meteorological Interactive Data Display System (MIDDS). The AMU first expanded the POR by two years by adding tower observations, surface observations and CCAFS (XMR) soundings for the cool season months of March 2007 to April 2009. The POR was expanded

  11. Emissions Scenarios and Fossil-fuel Peaking

    Science.gov (United States)

    Brecha, R.

    2008-12-01

    Intergovernmental Panel on Climate Change (IPCC) emissions scenarios are based on detailed energy system models in which demographics, technology and economics are used to generate projections of future world energy consumption, and therefore, of greenhouse gas emissions. Built into the assumptions for these scenarios are estimates for ultimately recoverable resources of various fossil fuels. There is a growing chorus of critics who believe that the true extent of recoverable fossil resources is much smaller than the amounts taken as a baseline for the IPCC scenarios. In a climate optimist camp are those who contend that "peak oil" will lead to a switch to renewable energy sources, while others point out that high prices for oil caused by supply limitations could very well lead to a transition to liquid fuels that actually increase total carbon emissions. We examine a third scenario in which high energy prices, which are correlated with increasing infrastructure, exploration and development costs, conspire to limit the potential for making a switch to coal or natural gas for liquid fuels. In addition, the same increasing costs limit the potential for expansion of tar sand and shale oil recovery. In our qualitative model of the energy system, backed by data from short- and medium-term trends, we have a useful way to gain a sense of potential carbon emission bounds. A bound for 21st century emissions is investigated based on two assumptions: first, that extractable fossil-fuel resources follow the trends assumed by "peak oil" adherents, and second, that little is done in the way of climate mitigation policies. If resources, and perhaps more importantly, extraction rates, of fossil fuels are limited compared to assumptions in the emissions scenarios, a situation can arise in which emissions are supply-driven. However, we show that even in this "peak fossil-fuel" limit, carbon emissions are high enough to surpass 550 ppm or 2°C climate protection guardrails. Some

  12. Contribution to thermodynamics and kinetics of argon, krypton and xenon at very low temperatures; Contribution a l'etude thermodynamique et cinetique de l'argon, du krypton et du xenon aux tres basses temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Levenson, L.L. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1969-07-01

    A critical analysis of the main theories of condensation, which are due to Zwanzig, Cabrera, Mc Caroll and Ehrlich, Wanlass, Armand, and Yu and Soo, is made. A condensation coefficient equal to unity is expected from these theories, except Armand and Yu and Soo, when the temperature of the gas impinging on its own solid phase is equal or less than 300 K. Using a resonating quartz microbalance the sensitivity of which is 10{sup -9} g. cm{sup 2} the experimental data agree with these theories when the temperature of the solid is less than 20 K. However the agreement must be interpreted for the more sophisticated theories of Armand and Yu and Soo. Regarding the sublimation of the rare gases one is faced with the theories of Salter, Eyring, Goodman and Armand. Within an order of magnitude the experimental data given here agree with the expected values. Moreover Armand theory is able to give the physical meaning of the observed results for argon sublimation from a krypton or a xenon crystalline substrate: localized modes of surface vibration occur. The relaxation time for the thermalization of the argon deposit is found greater than twelve hours at 25 K. (author) [French] Ce travail inclut l'etude critique des principales theories de la condensation dues a Zwanzig, Cabrera, Mc Caroll et Ehrlich, Wanlass, Armand, et Yu et Soo. Ces theories, sauf les deux dernieres, prevoient un coefficient de condensation egal a 1 lorsque le gaz incident sur son propre solide a une temperature inferieure ou egale a 300 K. Les mesures effectuees a l'aide d'une microbalance a quarz resonnant sensible a 10{sup -9} g. cm{sup 2} ont confirme ces theories dans le cas ou la temperature du solide est inferieure a 20 K. Cet accord doit cependant etre interprete pour les theories plus completes d'Armand d'une part, Yu et Soo d'autre part. Pour la sublimation des gaz rares on se trouve en presence des theories de Salter, Eyring, Goodman et Armand. Leurs previsions sont en accord, a un ordre de grandeur pres, avec les valeurs experimentales trouvees dans ce travail. De plus la theorie d'Armand donne une interpretation des resultats obtenus dans le cas de la sublimation de l'argon a partir d'un substrat de krypton ou de xenon: il y a apparition de modes localises de surface. La duree de la thermalisation complete de l'argon condense sur le krypton a 25 K est alors superieure a douze heures. (auteur)

  13. Temperature-insensitivity gas pressure sensor based on inflated long period fiber grating inscribed in photonic crystal fiber.

    Science.gov (United States)

    Zhong, Xiaoyong; Wang, Yiping; Liao, Changrui; Liu, Shen; Tang, Jian; Wang, Qiao

    2015-04-15

    We demonstrated an inflated long period fiber grating (I-LPFG) inscribed in a pure-silica photonic crystal fiber (PCF) for high-sensitivity gas pressure sensing applications. The I-LPFG was inscribed by use of the pressure-assisted CO2 laser beam-scanning technique to inflate periodically air holes of a PCF along the fiber axis. Such an I-LPFG with periodic inflations exhibits a very high gas pressure sensitivity of 1.68 nm/MPa, which is one order of magnitude higher than that, i.e., 0.12 nm/Mpa, of the LPFG without periodic inflations. Moreover, the I-LPFG has a very low temperature sensitivity of 3.1 pm/°C due to the pure silica material in the PCF so that the pressure measurement error, resulting from the cross-sensitivity between temperature and gas pressure, is less than 1.8 Kpa/°C in the case of no temperature compensation. So the I-LPFG could be used to develop a promising gas pressure sensor, and the achieved pressure measurement range is up to 10 MPa.

  14. Tim Peake and Britain's road to space

    CERN Document Server

    Seedhouse, Erik

    2017-01-01

    This book puts the reader in the flight suit of Britain’s first male astronaut, Tim Peake. It chronicles his life, along with the Principia mission and the down-to-the-last-bolt descriptions of life aboard the ISS, by way of the hurdles placed by the British government and the rigors of training at Russia’s Star City military base. In addition, this book discusses the learning curves required in astronaut and mission training and the complexity of the technologies required to launch an astronaut and keep them alive for months on end. This book underscores the fact that technology and training, unlike space, do not exist in a vacuum; complex technical systems, like the ISS, interact with the variables of human personality, and the cultural background of the astronauts. .

  15. Peak Electric Load Relief in Northern Manhattan

    Directory of Open Access Journals (Sweden)

    Hildegaard D. Link

    2014-08-01

    Full Text Available The aphorism “Think globally, act locally,” attributed to René Dubos, reflects the vision that the solution to global environmental problems must begin with efforts within our communities. PlaNYC 2030, the New York City sustainability plan, is the starting point for this study. Results include (a a case study based on the City College of New York (CCNY energy audit, in which we model the impacts of green roofs on campus energy demand and (b a case study of energy use at the neighborhood scale. We find that reducing the urban heat island effect can reduce building cooling requirements, peak electricity loads stress on the local electricity grid and improve urban livability.

  16. Comparison of five portable peak flow meters

    Directory of Open Access Journals (Sweden)

    Glaucia Nency Takara

    2010-01-01

    Full Text Available OBJECTIVE: To compare the measurements of spirometric peak expiratory flow (PEF from five different PEF meters and to determine if their values are in agreement. Inaccurate equipment may result in incorrect diagnoses of asthma and inappropriate treatments. METHODS: Sixty-eight healthy, sedentary and insufficiently active subjects, aged from 19 to 40 years, performed PEF measurements using Air Zone®, Assess®, Galemed®, Personal Best® and Vitalograph® peak flow meters. The highest value recorded for each subject for each device was compared to the corresponding spirometric values using Friedman's test with Dunn's post-hoc (p<0.05, Spearman's correlation test and Bland-Altman's agreement test. RESULTS: The median and interquartile ranges for the spirometric values and the Air Zone®, Assess®, Galemed®, Personal Best® and Vitalograph® meters were 428 (263-688 L/min, 450 (350-800 L/min, 420 (310-720 L/min, 380 (300-735 L/min, 400 (310-685 L/min and 415 (335-610 L/min, respectively. Significant differences were found when the spirometric values were compared to those recorded by the Air Zone® (p<0.001 and Galemed ® (p<0.01 meters. There was no agreement between the spirometric values and the five PEF meters. CONCLUSIONS: The results suggest that the values recorded from Galemed® meters may underestimate the actual value, which could lead to unnecessary interventions, and that Air Zone® meters overestimate spirometric values, which could obfuscate the need for intervention. These findings must be taken into account when interpreting both devices' results in younger people. These differences should also be considered when directly comparing values from different types of PEF meters.

  17. Comparison of five portable peak flow meters.

    Science.gov (United States)

    Takara, Glaucia Nency; Ruas, Gualberto; Pessoa, Bruna Varanda; Jamami, Luciana Kawakami; Di Lorenzo, Valéria Amorim Pires; Jamami, Mauricio

    2010-05-01

    To compare the measurements of spirometric peak expiratory flow (PEF) from five different PEF meters and to determine if their values are in agreement. Inaccurate equipment may result in incorrect diagnoses of asthma and inappropriate treatments. Sixty-eight healthy, sedentary and insufficiently active subjects, aged from 19 to 40 years, performed PEF measurements using Air Zone, Assess, Galemed, Personal Best and Vitalograph peak flow meters. The highest value recorded for each subject for each device was compared to the corresponding spirometric values using Friedman's test with Dunn's post-hoc (p<0.05), Spearman's correlation test and Bland-Altman's agreement test. The median and interquartile ranges for the spirometric values and the Air Zone, Assess, Galemed, Personal Best and Vitalograph meters were 428 (263-688 L/min), 450 (350-800 L/min), 420 (310-720 L/min), 380 (300-735 L/min), 400 (310-685 L/min) and 415 (335-610 L/min), respectively. Significant differences were found when the spirometric values were compared to those recorded by the Air Zone(R) (p<0.001) and Galemed (p<0.01) meters. There was no agreement between the spirometric values and the five PEF meters. The results suggest that the values recorded from Galemed meters may underestimate the actual value, which could lead to unnecessary interventions, and that Air Zone meters overestimate spirometric values, which could obfuscate the need for intervention. These findings must be taken into account when interpreting both devices' results in younger people. These differences should also be considered when directly comparing values from different types of PEF meters.

  18. Sample distribution in peak mode isotachophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Rubin, Shimon [Faculty of Mechanical Engineering, Technion - Israel Institute of Technology, Haifa (Israel); Schwartz, Ortal [Russel Berrie Nanotechnology Institute, Technion - Israel Institute of Technology, Haifa (Israel); Bercovici, Moran, E-mail: mberco@technion.ac.il [Faculty of Mechanical Engineering, Technion - Israel Institute of Technology, Haifa (Israel); Russel Berrie Nanotechnology Institute, Technion - Israel Institute of Technology, Haifa (Israel)

    2014-01-15

    We present an analytical study of peak mode isotachophoresis (ITP), and provide closed form solutions for sample distribution and electric field, as well as for leading-, trailing-, and counter-ion concentration profiles. Importantly, the solution we present is valid not only for the case of fully ionized species, but also for systems of weak electrolytes which better represent real buffer systems and for multivalent analytes such as proteins and DNA. The model reveals two major scales which govern the electric field and buffer distributions, and an additional length scale governing analyte distribution. Using well-controlled experiments, and numerical simulations, we verify and validate the model and highlight its key merits as well as its limitations. We demonstrate the use of the model for determining the peak concentration of focused sample based on known buffer and analyte properties, and show it differs significantly from commonly used approximations based on the interface width alone. We further apply our model for studying reactions between multiple species having different effective mobilities yet co-focused at a single ITP interface. We find a closed form expression for an effective-on rate which depends on reactants distributions, and derive the conditions for optimizing such reactions. Interestingly, the model reveals that maximum reaction rate is not necessarily obtained when the concentration profiles of the reacting species perfectly overlap. In addition to the exact solutions, we derive throughout several closed form engineering approximations which are based on elementary functions and are simple to implement, yet maintain the interplay between the important scales. Both the exact and approximate solutions provide insight into sample focusing and can be used to design and optimize ITP-based assays.

  19. Peak expiratory flow rate and Pulse Pressure values during the ...

    African Journals Online (AJOL)

    This study assessed the peak expiratory flow rate and pulse pressure during the luteal and menstruation phases of the menstrual cycle. The peak expiratory flow rate and pulse pressure were measured using the Wright's Peak Flow Meter and Mercury Sphygmomanometer respectively. The peak expiratory flow rate and ...

  20. Study of the peak effect phenomenon in single crystals of 2H-NbSe2

    Indian Academy of Sciences (India)

    Phase transformations in the flux line lattice (FLL) has been a subject of widespread in- terest for many years in ... Jc. ) , where hac is the amplitude of the ac field and α is a geometry and size dependent factor. This implies that the sudden enhancement of χ response corresponds to an anomalous and rapid increase in Jc.

  1. Peak-valley-peak pattern of histone modifications delineates active regulatory elements and their directionality

    DEFF Research Database (Denmark)

    Pundhir, Sachin; Bagger, Frederik Otzen; Lauridsen, Felicia Kathrine Bratt

    2016-01-01

    Formation of nucleosome free region (NFR) accompanied by specific histone modifications at flanking nucleosomes is an important prerequisite for enhancer and promoter activity. Due to this process, active regulatory elements often exhibit a distinct shape of histone signal in the form of a peak......-valley-peak (PVP) pattern. However, different features of PVP patterns and their robustness in predicting active regulatory elements have never been systematically analyzed. Here, we present PARE, a novel computational method that systematically analyzes the H3K4me1 or H3K4me3 PVP patterns to predict NFRs. We show...

  2. Conversion of broadband thermal radiation in lithium niobate crystals of various compositions

    Science.gov (United States)

    Syuy, A. V.; Litvinova, M. N.; Goncharova, P. S.; Sidorov, N. V.; Palatnikov, M. N.; Krishtop, V. V.; Likhtin, V. V.

    2013-05-01

    The conversion of the broadband thermal radiation in stoichiometric ( R = 1) lithium niobate single crystals that are grown from melt with 58.6 mol % of LiO2, congruent ( R = Li/Nb = 0.946) melt with the K2O flux admixture (4.5 and 6.0 wt %), and congruent melt and in congruent single crystals doped with the Zn2+, Gd3+, and Er3+ cations is studied. It is demonstrated that the conversion efficiency of the stoichiometric crystal that is grown from the melt with 58.6 mol % of LiO2 is less than the conversion efficiency of congruent crystal. In addition, the stoichiometric and almost stoichiometric crystals and the doped congruent crystals exhibit the blue shift of the peak conversion intensity in comparison with a nominally pure congruent crystal. For the congruent crystals, the conversion intensities peak at 520 and 495 nm, respectively.

  3. Can You Hear That Peak? Utilization of Auditory and Visual Feedback at Peak Limb Velocity

    Science.gov (United States)

    Loria, Tristan; de Grosbois, John; Tremblay, Luc

    2016-01-01

    Purpose: At rest, the central nervous system combines and integrates multisensory cues to yield an optimal percept. When engaging in action, the relative weighing of sensory modalities has been shown to be altered. Because the timing of peak velocity is the critical moment in some goal-directed movements (e.g., overarm throwing), the current study…

  4. OccuPeak: ChIP-Seq peak calling based on internal background modelling

    NARCIS (Netherlands)

    de Boer, Bouke A.; van Duijvenboden, Karel; van den Boogaard, Malou; Christoffels, Vincent M.; Barnett, Phil; Ruijter, Jan M.

    2014-01-01

    ChIP-seq has become a major tool for the genome-wide identification of transcription factor binding or histone modification sites. Most peak-calling algorithms require input control datasets to model the occurrence of background reads to account for local sequencing and GC bias. However, the

  5. Mixed crystal organic scintillators

    Energy Technology Data Exchange (ETDEWEB)

    Zaitseva, Natalia P; Carman, M Leslie; Glenn, Andrew M; Hamel, Sebastien; Hatarik, Robert; Payne, Stephen A; Stoeffl, Wolfgang

    2014-09-16

    A mixed organic crystal according to one embodiment includes a single mixed crystal having two compounds with different bandgap energies, the organic crystal having a physical property of exhibiting a signal response signature for neutrons from a radioactive source, wherein the signal response signature does not include a significantly-delayed luminescence characteristic of neutrons interacting with the organic crystal relative to a luminescence characteristic of gamma rays interacting with the organic crystal. According to one embodiment, an organic crystal includes bibenzyl and stilbene or a stilbene derivative, the organic crystal having a physical property of exhibiting a signal response signature for neutrons from a radioactive source.

  6. Development of peak performance in track cycling.

    Science.gov (United States)

    Schumacher, Y O; Mueller, P; Keul, J

    2001-06-01

    Retrospective analysis of peak performances can be a usefull tool for the estimation of future trends in high performance sports. The purpose of this study was to investigate the evolution of performance in track cycling from 1979 to 1999 and to asses age- and gender-related differences. We studied the results of the world track cycling championships for this period in 200 m, 1000 m, individual and team pursuit races for elite and junior athletes. Overall trends, performance differences between rank 1 and 5, gender- and age-related differences were calculated. They show a significant (ptrack cycling endurance disciplines. New technical developments show no statistical significant impact. The performance gap between male and female athletes is constant, independent of discipline or race distance and comparable to observations in other sports. Age-related differences in performance is most visible in disciplines requiring short, high intensity power output. Based on these data, estimation of possible winning times and adaptation of training programs for future track cycling competitions might be facilitated.

  7. Human behavioral complexity peaks at age 25

    Science.gov (United States)

    Brugger, Peter

    2017-01-01

    Random Item Generation tasks (RIG) are commonly used to assess high cognitive abilities such as inhibition or sustained attention. They also draw upon our approximate sense of complexity. A detrimental effect of aging on pseudo-random productions has been demonstrated for some tasks, but little is as yet known about the developmental curve of cognitive complexity over the lifespan. We investigate the complexity trajectory across the lifespan of human responses to five common RIG tasks, using a large sample (n = 3429). Our main finding is that the developmental curve of the estimated algorithmic complexity of responses is similar to what may be expected of a measure of higher cognitive abilities, with a performance peak around 25 and a decline starting around 60, suggesting that RIG tasks yield good estimates of such cognitive abilities. Our study illustrates that very short strings of, i.e., 10 items, are sufficient to have their complexity reliably estimated and to allow the documentation of an age-dependent decline in the approximate sense of complexity. PMID:28406953

  8. Scattering of ultrarelativistic electrons in ultrathin crystals

    Energy Technology Data Exchange (ETDEWEB)

    Shul' ga, N.F., E-mail: shulga@kipt.kharkov.ua [National Science Center “Kharkov Institute of Physics and Technology”, 1, Akademichna str., Kharkiv, 61108 (Ukraine); Karazin Kharkiv National University, 4, Svobody sq., Kharkiv, 61000 (Ukraine); Shulga, S.N. [National Science Center “Kharkov Institute of Physics and Technology”, 1, Akademichna str., Kharkiv, 61108 (Ukraine); Karazin Kharkiv National University, 4, Svobody sq., Kharkiv, 61000 (Ukraine)

    2017-06-10

    Quantum theory is proposed of high energy electrons scattering in ultrathin crystals. This theory is based upon a special representation of the scattering amplitude in the form of an integral over the surface surrounding the crystal, and on the spectral method of determination of the wave function. The comparison is performed of quantum and classical differential scattering cross-sections in the transitional range of crystal thicknesses, from those at which the channeling phenomenon is not developed up to those at which it is established. It is shown that in this thickness range the quantum scattering cross-section, unlike the classical one, contains sharp peaks corresponding to some specific scattering angles, that is connected with the diffraction of the incident plane wave onto the periodically distributed crystal atomic strings. It is shown that the value of the scattering cross-section in the peaks varies periodically with the change of the target thickness. We note that this must lead to a new interference effect in radiation that is connected with the rearrangement of incident wave packet in transitional area of crystal thicknesses.

  9. Scattering of ultrarelativistic electrons in ultrathin crystals

    Directory of Open Access Journals (Sweden)

    N.F. Shul'ga

    2017-06-01

    Full Text Available Quantum theory is proposed of high energy electrons scattering in ultrathin crystals. This theory is based upon a special representation of the scattering amplitude in the form of an integral over the surface surrounding the crystal, and on the spectral method of determination of the wave function. The comparison is performed of quantum and classical differential scattering cross-sections in the transitional range of crystal thicknesses, from those at which the channeling phenomenon is not developed up to those at which it is established. It is shown that in this thickness range the quantum scattering cross-section, unlike the classical one, contains sharp peaks corresponding to some specific scattering angles, that is connected with the diffraction of the incident plane wave onto the periodically distributed crystal atomic strings. It is shown that the value of the scattering cross-section in the peaks varies periodically with the change of the target thickness. We note that this must lead to a new interference effect in radiation that is connected with the rearrangement of incident wave packet in transitional area of crystal thicknesses.

  10. Pressure cryocooling protein crystals

    Science.gov (United States)

    Kim, Chae Un [Ithaca, NY; Gruner, Sol M [Ithaca, NY

    2011-10-04

    Preparation of cryocooled protein crystal is provided by use of helium pressurizing and cryocooling to obtain cryocooled protein crystal allowing collection of high resolution data and by heavier noble gas (krypton or xenon) binding followed by helium pressurizing and cryocooling to obtain cryocooled protein crystal for collection of high resolution data and SAD phasing simultaneously. The helium pressurizing is carried out on crystal coated to prevent dehydration or on crystal grown in aqueous solution in a capillary.

  11. CRYSTALLIZATION IN MULTICOMPONENT GLASSES

    Energy Technology Data Exchange (ETDEWEB)

    KRUGER AA; HRMA PR

    2009-10-08

    In glass processing situations involving glass crystallization, various crystalline forms nucleate, grow, and dissolve, typically in a nonuniform temperature field of molten glass subjected to convection. Nuclear waste glasses are remarkable examples of multicomponent vitrified mixtures involving partial crystallization. In the glass melter, crystals form and dissolve during batch-to-glass conversion, melter processing, and product cooling. Crystals often agglomerate and sink, and they may settle at the melter bottom. Within the body of cooling glass, multiple phases crystallize in a non-uniform time-dependent temperature field. Self-organizing periodic distribution (the Liesegnang effect) is common. Various crystallization phenomena that occur in glass making are reviewed.

  12. SEISMICITY OF THE LASSEN PEAK AREA, CALIFORNIA: 1981-1983.

    Science.gov (United States)

    Walter, Stephen R.; Rojas, Vernonica; Kollmann, Auriel

    1984-01-01

    Over 700 earthquakes occurred in the vicinity of Lassen Peak, California, from February 1981 through December 1983. These earthquakes define a broad, northwest-trending seismic zone that extends from the Sierra Nevada through the Lassen Peak area and either terminates or is offset to the northeast about 20 kilometers northwest of Lassen Peak. Approximately 25% of these earthquakes are associated with the geothermal system south of Lassen Peak. Earthquakes in the geothermal area generally occur at depths shallower than 6 kilometers.

  13. A contribution to peak load pricing theory and application

    OpenAIRE

    N. Vijayamohanan Pillai

    2003-01-01

    The present paper attempts at a contribution to peak load pricing, in both theory and application. The general result from the traditional theory that charges the off-peak consumers marginal operating costs only and the peak users marginal operating plus marginal capacity costs, since it is the on-peakers who press against capacity, has already been called into question in the literature. It has also been shown that the equity norms are violated in the traditional peak load pricing, whereby o...

  14. 7 CFR 457.163 - Nursery peak inventory endorsement.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 6 2010-01-01 2010-01-01 false Nursery peak inventory endorsement. 457.163 Section... CORPORATION, DEPARTMENT OF AGRICULTURE COMMON CROP INSURANCE REGULATIONS § 457.163 Nursery peak inventory endorsement. Nursery Crop Insurance Peak Inventory Endorsement This endorsement is not continuous and must be...

  15. Peak-power-point monitor for solar panel

    Science.gov (United States)

    Schloss, A. I.

    1972-01-01

    Attempt was made to determine solar cell panel peak power capability without disrupting power flow from panel. Separate solar cell strings were switched from panel circuits, and increasingly larger loads were added rapidly until peak power points were transversed. String wattage output was recorded and all stored string measurements summed together indicate peak power point in panel.

  16. Family practitioners perception of, knowledge about and use of peak ...

    African Journals Online (AJOL)

    Peak flow meters were underutilised by family practitioners. The cost of the peak flow meter was an important reported cause of underutilisation. It is recommended that the importance of the peak flow meter in the management of asthma be emphasised at the undergraduate and continuing medical education level.

  17. ASSESSING PEAK AEROBIC CAPACITY IN DUTCH LAW ENFORCEMENT OFFICERS

    NARCIS (Netherlands)

    Wittink, Harriet; Takken, Tim; de Groot, Janke; Reneman, Michiel; Peters, Roelof; Vanhees, Luc

    2015-01-01

    Objectives: To cross-validate the existing peak rate of oxygen consumption (VO2peak) prediction equations in Dutch law enforcement officers and to determine whether these prediction equations can be used to predict VO2peak for groups and in a single individual. A further objective was to report

  18. Peak expiratory flow at increased barometric pressure: comparison of peak flow meters and volumetric spirometer.

    Science.gov (United States)

    Thomas, P S; Ng, C; Bennett, M

    2000-01-01

    Increasing numbers of patients are receiving hyperbaric oxygen therapy as an intensive care treatment, some of whom have pre-existing airway obstruction. Spirometers are the ideal instruments for measuring airway obstruction, but peak flow meters are useful and versatile devices. The behaviour of both types of device was therefore studied in a hyperbaric unit under conditions of increased pressure. It is important to have a non-electrical indicator of airway obstruction, to minimize the fire risk in the hyperoxic environment. The hypothesis was tested that, assuming that dynamic resistance is unchanged, both the Wright's standard and mini-peak flow meters would over-read peak expiratory flow (PEF) under increased pressure when compared with a volumetric spirometer, as the latter is unaffected by air density. It was postulated that a correction factor could be derived so that PEF meters could be used in this setting. Seven normal subjects performed volume-dependent spirometry to derive PEF, and manoeuvres using both standard and mini PEF meters at sea level, under hyperbaric conditions at 303, 253 and 152 kPa (3, 2.5 and 1.5 atmospheres respectively; 1 atmosphere absolute=101.08 kPa), and again at sea level. There was a progressive and significant decline in PEF with increasing pressure as measured by the spirometer (69.46+/-0.8% baseline at 303 kPa compared with 101 kPa), while the PEF meters showed a progressive increase in their readings (an increase of 7.86+/-1.69% at 303 kPa with the mini PEF meter). Using these data points, a correction factor was derived which allows appropriate values to be calculated from the Wright's meter readings under these conditions.

  19. Growth of dopamine crystals

    Energy Technology Data Exchange (ETDEWEB)

    Patil, Vidya, E-mail: vidya.patil@ruparel.edu; Patki, Mugdha, E-mail: mugdha.patki@ruparel.edu [D. G. Ruparel College, Senapati Bapat Marg, Mahim, Mumbai – 400 016 (India)

    2016-05-06

    Many nonlinear optical (NLO) crystals have been identified as potential candidates in optical and electro-optical devices. Use of NLO organic crystals is expected in photonic applications. Hence organic nonlinear optical materials have been intensely investigated due to their potentially high nonlinearities, and rapid response in electro-optic effect compared to inorganic NLO materials. There are many methods to grow organic crystals such as vapor growth method, melt growth method and solution growth method. Out of these methods, solution growth method is useful in providing constraint free crystal. Single crystals of Dopamine have been grown by evaporating the solvents from aqueous solution. Crystals obtained were of the size of orders of mm. The crystal structure of dopamine was determined using XRD technique. Images of crystals were obtained using FEG SEM Quanta Series under high vacuum and low KV.

  20. Crystals in Urine Test

    Science.gov (United States)

    ... crystals or specific types of crystals can become kidney stones . Kidney stones are hard, pebble-like substances that can get ... big as a pea, or even larger. While kidney stones rarely cause serious damage, they can be very ...

  1. Preparation of Three-Dimensional Photonic Crystals of Zirconia by Electrodeposition in a Colloidal Crystals Template

    Directory of Open Access Journals (Sweden)

    Lei Pan

    2016-07-01

    Full Text Available Three-dimensional photonic crystals of zirconia were prepared by electrodeposition in a colloidal crystals template following calcination at 500 °C. Scanning electron microscopy, thermogravimetric analysis, X-ray diffraction, and reflectance spectroscopy were employed to characterize the photonic crystals of zirconia. It was found that hydrated zirconium ions could penetrate the colloidal crystals template and reach the substrate easily by electrodeposition, which resulted in stronger bonding between the substrate and the as-deposited membrane. Moreover, the electrodeposited membrane had low water content, leading to a low amount of shrinkage during calcination. Both these properties could suppress detachment from the substrate upon removal of the colloidal crystals template. Therefore, the three-dimensional photonic crystals of zirconia synthesized in this study exhibited very good preservation of the ordered structures of the colloidal crystals template with a high density. A peak of reflection higher than 70% was formed in the reflectance spectrum because of the strong diffraction of the ordered structures.

  2. Automatic peak selection by a Benjamini-Hochberg-based algorithm.

    Science.gov (United States)

    Abbas, Ahmed; Kong, Xin-Bing; Liu, Zhi; Jing, Bing-Yi; Gao, Xin

    2013-01-01

    A common issue in bioinformatics is that computational methods often generate a large number of predictions sorted according to certain confidence scores. A key problem is then determining how many predictions must be selected to include most of the true predictions while maintaining reasonably high precision. In nuclear magnetic resonance (NMR)-based protein structure determination, for instance, computational peak picking methods are becoming more and more common, although expert-knowledge remains the method of choice to determine how many peaks among thousands of candidate peaks should be taken into consideration to capture the true peaks. Here, we propose a Benjamini-Hochberg (B-H)-based approach that automatically selects the number of peaks. We formulate the peak selection problem as a multiple testing problem. Given a candidate peak list sorted by either volumes or intensities, we first convert the peaks into [Formula: see text]-values and then apply the B-H-based algorithm to automatically select the number of peaks. The proposed approach is tested on the state-of-the-art peak picking methods, including WaVPeak [1] and PICKY [2]. Compared with the traditional fixed number-based approach, our approach returns significantly more true peaks. For instance, by combining WaVPeak or PICKY with the proposed method, the missing peak rates are on average reduced by 20% and 26%, respectively, in a benchmark set of 32 spectra extracted from eight proteins. The consensus of the B-H-selected peaks from both WaVPeak and PICKY achieves 88% recall and 83% precision, which significantly outperforms each individual method and the consensus method without using the B-H algorithm. The proposed method can be used as a standard procedure for any peak picking method and straightforwardly applied to some other prediction selection problems in bioinformatics. The source code, documentation and example data of the proposed method is available at http://sfb.kaust.edu.sa/pages/software.aspx.

  3. Automatic Peak Selection by a Benjamini-Hochberg-Based Algorithm

    KAUST Repository

    Abbas, Ahmed

    2013-01-07

    A common issue in bioinformatics is that computational methods often generate a large number of predictions sorted according to certain confidence scores. A key problem is then determining how many predictions must be selected to include most of the true predictions while maintaining reasonably high precision. In nuclear magnetic resonance (NMR)-based protein structure determination, for instance, computational peak picking methods are becoming more and more common, although expert-knowledge remains the method of choice to determine how many peaks among thousands of candidate peaks should be taken into consideration to capture the true peaks. Here, we propose a Benjamini-Hochberg (B-H)-based approach that automatically selects the number of peaks. We formulate the peak selection problem as a multiple testing problem. Given a candidate peak list sorted by either volumes or intensities, we first convert the peaks into p-values and then apply the B-H-based algorithm to automatically select the number of peaks. The proposed approach is tested on the state-of-the-art peak picking methods, including WaVPeak [1] and PICKY [2]. Compared with the traditional fixed number-based approach, our approach returns significantly more true peaks. For instance, by combining WaVPeak or PICKY with the proposed method, the missing peak rates are on average reduced by 20% and 26%, respectively, in a benchmark set of 32 spectra extracted from eight proteins. The consensus of the B-H-selected peaks from both WaVPeak and PICKY achieves 88% recall and 83% precision, which significantly outperforms each individual method and the consensus method without using the B-H algorithm. The proposed method can be used as a standard procedure for any peak picking method and straightforwardly applied to some other prediction selection problems in bioinformatics. The source code, documentation and example data of the proposed method is available at http://sfb.kaust.edu.sa/pages/software.aspx. © 2013

  4. Crystal growth, structural, low temperature thermoluminescence and mechanical properties of cubic fluoroperovskite single crystal (LiBaF3)

    Science.gov (United States)

    Daniel, D. Joseph; Ramasamy, P.; Ramaseshan, R.; Kim, H. J.; Kim, Sunghwan; Bhagavannarayana, G.; Cheon, Jong-Kyu

    2017-10-01

    Polycrystalline compounds of LiBaF3 were synthesized using conventional solid state reaction route and the phase purity was confirmed using powder X-ray diffraction technique. Using vertical Bridgman technique single crystal was grown from melt. Rocking curve measurements have been carried out to study the structural perfection of the grown crystal. The single peak of diffraction curve clearly reveals that the grown crystal was free from the structural grain boundaries. The low temperature thermoluminescence of the X-ray irradiated sample has been analyzed and found four distinguishable peaks having maximum temperatures at 18, 115, 133 and 216 K. Activation energy (E) and frequency factor (s) for the individual peaks have been studied using Peak shape method and the computerized curve fitting method combining with the Tmax- TStop procedure. Nanoindentation technique was employed to study the mechanical behaviour of the crystal. The indentation modulus and Vickers hardness of the grown crystal have values of 135.15 GPa and 680.81 respectively, under the maximum indentation load of 10 mN.

  5. Direct observation of a pulse peak using a peak-removed Gaussian optical pulse in a superluminal medium.

    Science.gov (United States)

    Tomita, Makoto; Amano, Heisuke; Masegi, Seiji; Talukder, Aminul I

    2014-03-07

    A series of experiments is performed to examine the arrival of a pulse peak, using a Gaussian-shaped temporal wave packet as the input pulse and truncating it at various positions on or before the peak of the packet. When the truncating point is within the negative group delay limit of the fast light medium, a smooth Gaussian peak is observed at the exit port, despite the absence of an input pulse peak. The experimental results explicitly demonstrate that the superluminal propagation of a smooth Gaussian-shaped pulse peak is an analytic continuation over time of the earlier portion of the input pulse envelope. To investigate the physical meaning of the pulse peak further, we also examine the propagation of triangular-shaped pulses, for which the pulse peak can be recognized as a nonanalytical point.

  6. QRS peak detection for heart rate monitoring on Android smartphone

    Science.gov (United States)

    Pambudi Utomo, Trio; Nuryani, Nuryani; Darmanto

    2017-11-01

    In this study, Android smartphone is used for heart rate monitoring and displaying electrocardiogram (ECG) graph. Heart rate determination is based on QRS peak detection. Two methods are studied to detect the QRS complex peak; they are Peak Threshold and Peak Filter. The acquisition of ECG data is utilized by AD8232 module from Analog Devices, three electrodes, and Microcontroller Arduino UNO R3. To record the ECG data from a patient, three electrodes are attached to particular body’s surface of a patient. Patient’s heart activity which is recorded by AD8232 module is decoded by Arduino UNO R3 into analog data. Then, the analog data is converted into a voltage value (mV) and is processed to get the QRS complex peak. Heart rate value is calculated by Microcontroller Arduino UNO R3 uses the QRS complex peak. Voltage, heart rate, and the QRS complex peak are sent to Android smartphone by Bluetooth HC-05. ECG data is displayed as the graph by Android smartphone. To evaluate the performance of QRS complex peak detection method, three parameters are used; they are positive predictive, accuracy and sensitivity. Positive predictive, accuracy, and sensitivity of Peak Threshold method is 92.39%, 70.30%, 74.62% and for Peak Filter method are 98.38%, 82.47%, 83.61%, respectively.

  7. Color image recognition by use of a joint transform correlator of three liquid-crystal televisions.

    Science.gov (United States)

    Hsieh, Mei-Li; Hsu, Ken Y; Zhai, Hongchen

    2002-03-10

    We present a joint transform correlator for color image recognition by using three liquid-crystal spatial light modulators. A method for simultaneously obtaining the correlation peaks of red, green, and blue is proposed and experimentally demonstrated.

  8. Reference Values for Peak Exercise Cardiac Output in Healthy Individuals.

    Science.gov (United States)

    Agostoni, Piergiuseppe; Vignati, Carlo; Gentile, Piero; Boiti, Costanza; Farina, Stefania; Salvioni, Elisabetta; Mapelli, Massimo; Magrì, Damiano; Paolillo, Stefania; Corrieri, Nicoletta; Sinagra, Gianfranco; Cattadori, Gaia

    2017-06-01

    Cardiac output (Q˙) is a key parameter in the assessment of cardiac function, its measurement being crucial for the diagnosis, treatment, and prognostic evaluation of all heart diseases. Until recently, Q˙ determination at peak exercise has been possible through invasive methods, so that normal values were obtained in studies based on small populations. Nowadays, peak Q˙ can be measured noninvasively by means of the inert gas rebreathing (IGR) technique. The present study was undertaken to provide reference values for peak Q˙ in the normal general population and to obtain a formula able to estimate peak exercise Q˙ from measured peak oxygen uptake (V˙o2). We studied 500 normal subjects (age, 44.9 ± 1.5 years; range, 18-77 years; 260 men, 240 women) who underwent a maximal cardiopulmonary exercise test with peak Q˙ measurement by IGR. In the overall study sample, peak Q˙ was 13.2 ± 3.5 L/min (men, 15.3 ± 3.3 L/min; women, 11.0 ± 2.0 L/min; P exercise was (4.4 × peak V˙o2) + 4.3 in the overall study cohort, (4.3 × peak V˙o2) + 4.5 in men, and (4.9 × peak V˙o2) + 3.6 in women. The simultaneous measurement of Q˙ and V˙o2 at peak exercise in a large sample of healthy subjects provided an equation to predict peak Q˙ from peak V˙o2 values. Copyright © 2017 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

  9. Electrically Rotatable Polarizer Using One-Dimensional Photonic Crystal with a Nematic Liquid Crystal Defect Layer

    Directory of Open Access Journals (Sweden)

    Ryotaro Ozaki

    2015-09-01

    Full Text Available Polarization characteristics of defect mode peaks in a one-dimensional (1D photonic crystal (PC with a nematic liquid crystal (NLC defect layer have been investigated. Two different polarized defect modes are observed in a stop band. One group of defect modes is polarized along the long molecular axis of the NLC, whereas another group is polarized along its short axis. Polarizations of the defect modes can be tuned by field-induced in-plane reorientation of the NLC in the defect layer. The polarization properties of the 1D PC with the NLC defect layer is also investigated by the finite difference time domain (FDTD simulation.

  10. Photonic crystal light source

    Science.gov (United States)

    Fleming, James G [Albuquerque, NM; Lin, Shawn-Yu [Albuquerque, NM; Bur, James A [Corrales, NM

    2004-07-27

    A light source is provided by a photonic crystal having an enhanced photonic density-of-states over a band of frequencies and wherein at least one of the dielectric materials of the photonic crystal has a complex dielectric constant, thereby producing enhanced light emission at the band of frequencies when the photonic crystal is heated. The dielectric material can be a metal, such as tungsten. The spectral properties of the light source can be easily tuned by modification of the photonic crystal structure and materials. The photonic crystal light source can be heated electrically or other heating means. The light source can further include additional photonic crystals that exhibit enhanced light emission at a different band of frequencies to provide for color mixing. The photonic crystal light source may have applications in optical telecommunications, information displays, energy conversion, sensors, and other optical applications.

  11. Group Elevator Peak Scheduling Based on Robust Optimization Model

    OpenAIRE

    Zhang, J.; Q. Zong

    2013-01-01

    Scheduling of Elevator Group Control System (EGCS) is a typical combinatorial optimization problem. Uncertain group scheduling under peak traffic flows has become a research focus and difficulty recently. RO (Robust Optimization) method is a novel and effective way to deal with uncertain scheduling problem. In this paper, a peak scheduling method based on RO model for multi-elevator system is proposed. The method is immune to the uncertainty of peak traffic flows, optimal scheduling is re...

  12. Peak experiences of psilocybin users and non-users.

    Science.gov (United States)

    Cummins, Christina; Lyke, Jennifer

    2013-01-01

    Maslow (1970) defined peak experiences as the most wonderful experiences of a person's life, which may include a sense of awe, well-being, or transcendence. Furthermore, recent research has suggested that psilocybin can produce experiences subjectively rated as uniquely meaningful and significant (Griffiths et al. 2006). It is therefore possible that psilocybin may facilitate or change the nature of peak experiences in users compared to non-users. This study was designed to compare the peak experiences of psilocybin users and non-users, to evaluate the frequency of peak experiences while under the influence of psilocybin, and to assess the perceived degree of alteration of consciousness during these experiences. Participants were recruited through convenience and snowball sampling from undergraduate classes and at a musical event. Participants were divided into three groups, those who reported a peak experience while under the influence of psilocybin (psilocybin peak experience: PPE), participants who had used psilocybin but reported their peak experiences did not occur while they were under the influence of psilocybin (non-psilocybin peak experience: NPPE), and participants who had never used psilocybin (non-user: NU). A total of 101 participants were asked to think about their peak experiences and complete a measure evaluating the degree of alteration of consciousness during that experience. Results indicated that 47% of psilocybin users reported their peak experience occurred while using psilocybin. In addition, there were significant differences among the three groups on all dimensions of alteration of consciousness. Future research is necessary to identify factors that influence the peak experiences of psilocybin users in naturalistic settings and contribute to the different characteristics of peak experiences of psilocybin users and non-users.

  13. Living with peak discharge uncertainty: the self-learning dike

    OpenAIRE

    de Kok, Jean-Luc; Hoekstra, Arjen Ysbert; Sànchez-Marrè, Miquel; Béjar, Javier; Comas, Joaquim; Rizzoli, Andrea E.; Guariso, Giorgio

    2008-01-01

    Although river dikes still play a key role for flood protection in the Netherlands there is a growing interest for other measures to deal with larger peak discharges, such as lowering or widening the floodplains. Regardless of the strategy chosen the assessment of its effect on the flood risk depends on the peak discharge statistics. A problem here is that the statistical analysis of peak discharges relies on probability distributions based on the limited time series of extreme discharges. Th...

  14. [Prony analysis method about P-peak detection in ECG].

    Science.gov (United States)

    Li, Ran; Fang, Bin; Shen, Yi; Sun, Chongzheng; Wang, Pu

    2008-12-01

    The technology of ECG (Electrocardiograph) auto-analysis has developed rapidly in recent years. There are lots of related techniques appearing. The majority is about R-peak detection. Although P-peak is important too, there are a few kinds of method about P-peak detection. In this paper is presented a new method for P-peak detection. According to Prony analysis, ECG is separated first, and then detected. The method gets good result. Data in experiment are from MIT Arrhythmia Database. The reliability of this algorithm in accurately detecting the P location is 97.8%.

  15. The Hunt for the explanation of the Double Peak hydrograph

    Science.gov (United States)

    Martínez-Carreras, Núria; Hissler, Christophe; François Iffly, Jean; Klaus, Julian; Gourdol, Laurent; Juilleret, Jérôme; McDonnell, Jeffrey J.; Pfister, Laurent

    2015-04-01

    Double peak hydrographs (also known as bimodal events) are a catchment's delayed response to precipitation. "Double peaks" have been reported in a dozen or so experimental catchments around the world, including the well-studied Slapton Wood catchment in UK and the Ina watersheds in Japan. Catchments showing double peak behaviour have varied in size, morphology, geology and soils. While first peaks are often coincident with the rainfall event, the second peak generally takes the form of a broader peak that reaches its maximum lagged in time from the initial response. Generally the double peaks response occurs only when catchments are wetted-up. In most cases, saturation-excess overland flow in the near-stream areas controls the initial peak in the double-peaked event while the second peak (i.e. the delayed peak) is controlled by subsurface stormflow. However, clear evidence for the mechanisms explaining these complex hydrological dynamics across diverse catchments is still wanting. Here we investigate the cause(s) of the size and magnitude of the second peak and the hydrological settings leading to its activation in the schistous Weierbach headwater catchment (0.45 km2, Luxembourg). We make use of the extensive high-resolution hydrometric time series of rainfall, runoff, soil moisture and depth to groundwater levels to estimate water catchment storage and causal linkages. The catchment was partitioned in three discrete hydrological response units (HRUs) to determine if delayed runoff is controlled by connectivity between discrete landscape units. We found evidence of catchment storage being a dominant control on the second peak activation. A threshold behaviour between catchment storage and the appearance of the second peak was observed. The amount of this storage threshold was temporally consistent over the 3-years period and was observed not only during the wet season, but also in summer when the catchment was exceptionally wet. We did not observe a rainfall

  16. The Effect of Crystallizing and Non-crystallizing Cosolutes on Succinate Buffer Crystallization and the Consequent pH Shift in Frozen Solutions

    Energy Technology Data Exchange (ETDEWEB)

    Sundaramurthi, Prakash; Suryanarayanan, Raj (UMM)

    2011-09-06

    To effectively inhibit succinate buffer crystallization and the consequent pH changes in frozen solutions. Using differential scanning calorimetry (DSC) and X-ray diffractometry (XRD), the crystallization behavior of succinate buffer in the presence of either (i) a crystallizing (glycine, mannitol, trehalose) or (ii) a non-crystallizing cosolute (sucrose) was evaluated. Aqueous succinate buffer solutions, 50 or 200 mM, at pH values 4.0 or 6.0 were cooled from room temperature to -25 C at 0.5 C/min. The pH of the solution was measured as a function of temperature using a probe designed to function at low temperatures. The final lyophiles prepared from these solutions were characterized using synchrotron radiation. When the succinic acid solution buffered to pH 4.0, in the absence of a cosolute, was cooled, there was a pronounced shift in the freeze-concentrate pH. Glycine and mannitol, which have a tendency to crystallize in frozen solutions, remained amorphous when the initial pH was 6.0. Under this condition, they also inhibited buffer crystallization and prevented pH change. At pH 4.0 (50 mM initial concentration), glycine and mannitol crystallized and did not prevent pH change in frozen solutions. While sucrose, a non-crystallizing cosolute, did not completely prevent buffer crystallization, the extent of crystallization was reduced. Sucrose decomposition, based on XRD peaks attributable to {beta}-D-glucose, was observed in frozen buffer solutions with an initial pH of 4.0. Trehalose completely inhibited crystallization of the buffer components when the initial pH was 6.0 but not at pH 4.0. At the lower pH, the crystallization of both trehalose dihydrate and buffer components was evident. When retained amorphous, sucrose and trehalose effectively inhibited succinate buffer component crystallization and the consequent pH shift. However, when trehalose crystallized or sucrose degraded to yield a crystalline decomposition product, crystallization of buffer was

  17. Experimental phasing using zinc and sulfur anomalous signals measured at the zinc absorption peak.

    Science.gov (United States)

    Lee, Sangmin; Kim, Min-Kyu; Ji, Chang-Jun; Lee, Jin-Won; Cha, Sun-Shin

    2013-10-01

    Iron is an essential transition metal required for bacterial growth and survival. Excess free iron can lead to the generation of reactive oxygen species that can cause severe damage to cellular functions. Cells have developed iron-sensing regulators to maintain iron homeostasis at the transcription level. The ferric uptake regulator (Fur) is an iron-responsive regulator that controls the expression of genes involved in iron homeostasis, bacterial virulence, stress resistance, and redox metabolism. Here, we report the expression, purification, crystallization, and phasing of the apo-form of Bacillus subtilis Fur (BsFur) in the absence of regulatory metal ions. Crystals were obtained by microbatch crystallization method at 295 K and diffraction data at a resolution of 2.6 Å was collected at the zinc peak wavelength (λ=1.2823 Å). Experimental phasing identified the positions of one zinc atom and four sulfur atoms of cysteine residues coordinating the zinc atom, indicating that the data contained a meaningful anomalous scattering originating from the ordered zinc-coordinating sulfur atoms, in spite of the small anomalous signals of sulfur atoms at the examined wavelength.

  18. Assessing peak aerobic capacity in Dutch law enforcement officers

    Directory of Open Access Journals (Sweden)

    Harriet Wittink

    2015-06-01

    Full Text Available Objectives: To cross-validate the existing peak rate of oxygen consumption (VO2peak prediction equations in Dutch law enforcement officers and to determine whether these prediction equations can be used to predict VO2peak for groups and in a single individual. A further objective was to report normative absolute and relative VO2peak values of a sample of law enforcement officers in the Netherlands. Material and Methods: The peak rate of oxygen consumption (ml×kg–1×min–1 was measured using a maximal incremental bicycle test in 1530 subjects, including 1068 male and 461 female police officers. Validity of the prediction equations for groups was assessed by comparing predicted VO2peak with measured VO2peak using paired t-tests. For individual differences limits of agreement (LoA were calculated. Equations were considered valid for individuals when the difference between measured and predicted VO2peak did not exceed ±1 metabolic equivalent (MET in 95% of individuals. Results: None of the equations met the validity criterion of 95% of individuals having ±1 MET difference or less than the measured value. Limits of agreement (LoAs were large in all predictions. At the individual level, none of the equations were valid predictors of VO2peak (ml×kg–1×min–1. Normative values for Dutch law enforcement officers were presented. Conclusions: Substantial differences between measured and predicted VO2peak (ml×kg–1×min–1 were found. Most tested equations were invalid predictors of VO2peak at group level and all were invalid at individual levels.

  19. EXAFS investigations on PbMoO4 single crystals grown under ...

    Indian Academy of Sciences (India)

    Some information pertaining to the presence of possible impurity phases in stoichiometry deficient crystals was also reported recently (Sangeeta et al 2006). X-ray photoelectron spectroscopic (XPS) investigations carried out have revealed the presence of a single peak in photoelectron spectrum of Mo3d for LMO crystals ...

  20. Insights into the nucleation role of cellulose crystals during crystallization of poly(β-hydroxybutyrate).

    Science.gov (United States)

    Chen, Jianxiang; Xu, Chunjiang; Wu, Defeng; Pan, Keren; Qian, Aiwen; Sha, Yulu; Wang, Li; Tong, Wei

    2015-12-10

    Cellulose crystals, including microcrystalline cellulose (MCC) and nanocrystalline cellulose (NCC), were used as the fillers to prepare green composites with poly(β-hydroxybutyrate) (PHB) by melt mixing for crystallization study. The results reveal that the spherulite morphology of PHB and its composites depends highly on the crystallization temperature, evolving from bundle shaped to ring-banded and finally to irregular or zigzag textures with increase of temperature. However, the ring-banded structure is strongly affected by the presence of cellulose crystals, and the average band space decreases evidently with the addition of MCC or NCC. Compared with PHB/MCC composite, PHB/NCC composite shows degraded spherulite structure with smaller band space and higher flocculation level of peak-to-valley height because of stronger unbalanced stresses in this system. Besides, cellulose crystals can act as good heterogeneous nucleating agent to accelerate the crystallization of PHB, which is further confirmed by the polarized optical microscopy observations and the kinetic analyses. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Crystallization of Macromolecules

    Science.gov (United States)

    Friedmann, David; Messick, Troy; Marmorstein, Ronen

    2014-01-01

    X-ray crystallography has evolved into a very powerful tool to determine the three-dimensional structure of macromolecules and macromolecular complexes. The major bottleneck in structure determination by X-ray crystallography is the preparation of suitable crystalline samples. This unit outlines steps for the crystallization of a macromolecule, starting with a purified, homogeneous sample. The first protocols describe preparation of the macromolecular sample (i.e., proteins, nucleic acids, and macromolecular complexes). The preparation and assessment of crystallization trials is then described, along with a protocol for confirming whether the crystals obtained are composed of macromolecule as opposed to a crystallization reagent . Next, the optimization of crystallization conditions is presented. Finally, protocols that facilitate the growth of larger crystals through seeding are described. PMID:22045560

  2. Electronic crystal growth

    Science.gov (United States)

    Sato, T.; Miyagawa, K.; Kanoda, K.

    2017-09-01

    Interacting atoms or molecules condense into liquid, and, when cooled further, they form a crystal. The time evolution of the atomic or molecular ordering has been widely studied as a nonequilibrium emergence of order from a supercooled liquid or a glass. Interacting electrons in a variety of correlated electron systems also form crystals, but observing the time evolution of electronic crystallization has been experimentally challenging. Here, working with an organic conductor exhibiting a supercooled charge liquid or charge glass as a metastable state, we observed electronic crystal growth through resistivity and nuclear magnetic resonance measurements. The temperature profile of the crystal growth is similar to those observed in classical systems and reveals two distinct regimes for the mechanism of electronic crystallization.

  3. Active Photonic Crystal Waveguides

    DEFF Research Database (Denmark)

    Ek, Sara

    due to photonic crystal dispersion. The observations are explained by the enhancement of net gain by light slow down. Another application based on active photonic crystal waveguides is micro lasers. Measurements on quantum dot micro laser cavities with different mirror configurations and photonic......This thesis deals with the fabrication and characterization of active photonic crystal waveguides, realized in III-V semiconductor material with embedded active layers. The platform offering active photonic crystal waveguides has many potential applications. One of these is a compact photonic...... crystal semiconductor optical amplier. As a step towards such a component, photonic crystal waveguides with a single quantum well, 10 quantum wells and three layers of quantum dots are fabricated and characterized. An experimental study of the amplied spontaneous emission and a implied transmission...

  4. A rise in peak performance age in female athletes.

    Science.gov (United States)

    Elmenshawy, Ahmed R; Machin, Daniel R; Tanaka, Hirofumi

    2015-06-01

    It was reported in 1980s that ages at which peak performance was observed had remained remarkably stable in the past century, although absolute levels of athletic performance increased dramatically for the same time span. The emergence of older (masters) athletes in the past few decades has changed the demographics and age-spectrum of Olympic athletes. The primary aim of the present study was to determine whether the ages at which peak performance was observed had increased in the recent decades. The data spanning 114 years from the first Olympics (1898) to the most recent Olympics (2014) were collected using the publically available data. In the present study, ages at which Olympic medals (gold, silver, and bronze) were won were used as the indicators of peak performance age. Track and field, swimming, rowing, and ice skating events were analyzed. In men, peak performance age did not change significantly in most of the sporting events (except in 100 m sprint running). In contrast, peak performance ages in women have increased significantly since 1980s and consistently in all the athletic events examined. Interestingly, as women's peak performance age increased, they became similar to men's peak ages in many events. In the last 20-30 years, ages at which peak athletic performance is observed have increased in women but not in men.

  5. Daily Nigerian peak load forecasting using artificial neural network ...

    African Journals Online (AJOL)

    A daily peak load forecasting technique that uses artificial neural network with seasonal indices is presented in this paper. A neural network of relatively smaller size than the main prediction network is used to predict the daily peak load for a period of one year over which the actual daily load data are available using one ...

  6. Flood Peak Estimation Using Rainfall Run off Models | Matondo ...

    African Journals Online (AJOL)

    The design of hydraulic structures such as road culverts, road bridges and dam spillways requires the determination of the design food peak. Two approaches are available in the determination of the design flood peak and these are: flood frequency analysis and rainfall runoff models. Flood frequency analysis requires a ...

  7. Peak effect in surface resistance at microwave frequencies in Dy ...

    Indian Academy of Sciences (India)

    A pronounced peak in the microwave (at frequency 9.55 GHz) surface resistance, Rs vs. T plot (where T is the ... Peak effect; flux line lattice; microwave surface resistance. PACS Nos 74.76.-w; 74.60. .... vortex lines from defect structures, such as twin planes and defect clusters, having differ- ent pinning potentials (or ...

  8. Peak Expiratory Flow Rate In Cigarette Smokers | Ukoli | Highland ...

    African Journals Online (AJOL)

    Objective: To compare lung function between smokers and non-smokers using Peak Expiratory Flow Rate (PEFR). Methods: This study examines the peak expiratory flow rate (PEFR) of three hundred and forty cigarette smokers, age and sex-matched with PEFR of equal number of non-smokers. Results: The mean PEFR of ...

  9. Daily peak electricity load forecasting in South Africa using a ...

    African Journals Online (AJOL)

    Accurate prediction of daily peak load demand is very important for decision makers in the energy sector. This helps in the determination of consistent and reliable supply schedules during peak periods. Accurate short term load forecasts enable eective load shifting between transmission substations, scheduling of startup ...

  10. Psychological Preparation for Peak Performance in Sports Competition

    Science.gov (United States)

    Ohuruogu, Ben; Jonathan, Ugwuanyi I.; Ikechukwu, Ugwu Jude

    2016-01-01

    This paper attempts to make an overview of various techniques, sport psychologist adopt in psychological preparation of athletes for peak performance. To attain peak performance in sports competitions, coaches and athletes should not base their prospect on physical training on sport skills alone rather should integrate both the mental and physical…

  11. Mazama and Glacier Peak Volcanic Ash Layers: Relative Ages.

    Science.gov (United States)

    Fryxell, R

    1965-03-12

    Physiographic and stratigraphic evidence supports the regional correlation of two volcanic ash layers with extinct Mount Mazama at Crater Lake, Oregon, and Glacier Peak in the northern Cascade Range of Washington. A radiocarbon age of 12,000 +/- 310 years confirms geological evidence that ash derived from the Glacier Peak eruption is substantially older than ash from the Mazama eruption of 6600 years ago.

  12. Online junction temperature measurement using peak gate current

    DEFF Research Database (Denmark)

    Baker, Nick; Munk-Nielsen, Stig; Iannuzzo, Francesco

    2015-01-01

    A new method for junction temperature measurement of MOS-gated power semiconductor switches is presented. The measurement method involves detecting the peak voltage over the external gate resistor of an IGBT or MOSFET during turn-on. This voltage is directly proportional to the peak gate current...

  13. Probabilistic Analysis of Peak Daily Rainfall for Prediction purposes ...

    African Journals Online (AJOL)

    The obtained peak daily rainfall values were subjected to Gumbel, Log-Gumbel, Normal, Log-Normal, Pearson and Log-Pearson probability distributions. Mathematical equation for probability distribution functions were established for each town and used to predict peak rainfall. The predicted values were subjected to ...

  14. Single Crystal Faceplate Evaluation

    Science.gov (United States)

    1993-10-25

    7]. Much the research at Allied-Signal, Inc. in garnet layer growth has been involved with the kinetics of crystallization of garnet from LPE melts...acceptable resolution and light output characteristics. Single crystal faceplates being evaluated are composed of yttrium aluminum garnet (YAG) with an...1.1 Single Crystal Faceplate Developments Allied Signal, Inc. has done extensive development work in epitaxial layering of yttrium aluminum garnet (YAG

  15. Analysis of liquid crystal properties for photonic crystal fiber devices

    DEFF Research Database (Denmark)

    Weirich, Johannes; Lægsgaard, Jesper; Wei, Lei

    2009-01-01

    We analyze the bandgap structure of Liquid Crystal infiltrated Photonic Crystal Fibers depending on the parameters of the Liquid Crystals by means of finite element simulations. For a biased Liquid Crystal Photonic Crystal Fiber, we show how the tunability of the bandgap position depends...

  16. Impact of Smart Grid Technologies on Peak Load to 2050

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    The IEA's Smart Grids Technology Roadmap identified five global trends that could be effectively addressed by deploying smart grids. These are: increasing peak load (the maximum power that the grid delivers during peak hours), rising electricity consumption, electrification of transport, deployment of variable generation technologies (e.g. wind and solar PV) and ageing infrastructure. Along with this roadmap, a new working paper -- Impact of Smart Grid Technologies on Peak Load to 2050 -- develops a methodology to estimate the evolution of peak load until 2050. It also analyses the impact of smart grid technologies in reducing peak load for four key regions; OECD North America, OECD Europe, OECD Pacific and China. This working paper is a first IEA effort in an evolving modelling process of smart grids that is considering demand response in residential and commercial sectors as well as the integration of electric vehicles.

  17. Maximizing utilization of sport halls during peak hours

    DEFF Research Database (Denmark)

    Iversen, Evald Bundgård; Forsberg, Peter

    BACKGROUNDDuring peak hours (4.30pm-8pm) demand for timeslots in sport halls in Denmark are high and there are few timeslots available. Further, focus on how public resources are spent most efficient is increasing (Iversen, 2013). This makes it interesting to analyse how utilization could...... be increased during peak hours. DATA AND METHODOLOGYData is collected by observation of activities during two weeks on for example whether halls are used or not; the amount of playing field used; and number of participants (Iversen, 2012). Data on 1.331 activities in 36 sport halls across 4 municipalities have...... been collected. RESULTS The number of participants per activity is higher during peak hours, which is expected when demand is high. However, the usage of sport floor only differs slightly between peak and low hours. Both during peak and low hours on average 80-100 per cent of floor space is used...

  18. Diffraction peak shift in MgO small crystallites

    Science.gov (United States)

    Gielen, P.

    1998-08-01

    A linear relationship is found between peak position and peak width for the X-ray diffraction peaks of MgO very small crystallites. The sign of the peak shift is explained. The peak shape is asymmetrical, the more asymmetrical the broader it is. The second Heisenberg's uncertainty relation is reinterpreted. L'auteur trouve une relation linéaire entre la position des pics et la largeur des pics de diffraction des rayons X pour de très petites cristallites de MgO. Il explique le signe du déplacement des pics. La forme des pics est asymétrique, d'autant plus asymétrique qu'ils sont plus larges. La seconde relation d'incertitude de Heisenberg est réinterprétée.

  19. Crystallization Formulation Lab

    Data.gov (United States)

    Federal Laboratory Consortium — The Crystallization Formulation Lab fills a critical need in the process development and optimization of current and new explosives and energetic formulations. The...

  20. A crystal barrel

    CERN Multimedia

    2007-01-01

    The production of crystals for the barrel of the CMS electromagnetic calorimeter has been completed. This is an important milestone for the experiment, which received the last of its 62,960 crystals on 9 March. The members of the team responsible for the crystal acceptance testing at CERN display the last crystal for the CMS electromagnetic calorimeter barrel. From left to right: Igor Tarasov, Etiennette Auffray and Hervé Cornet.One of the six machines specially developed to measure 67 different parameters on each crystal. Igor Tarasov is seen inserting the last batch of crystals into the machine. The last of the 62,960 CMS barrel crystals arrived at CERN on 9 March. Once removed from its polystyrene protection, this delicate crystal, like thousands of its predecessors, will be inserted into the last of the 36 supermodules of the barrel electromagnetic calorimeter in a few days' time. This marks the end of an important chapter in an almost 15-year-long journey by the CMS crystals team, some of whose member...

  1. Automation in biological crystallization.

    Science.gov (United States)

    Stewart, Patrick Shaw; Mueller-Dieckmann, Jochen

    2014-06-01

    Crystallization remains the bottleneck in the crystallographic process leading from a gene to a three-dimensional model of the encoded protein or RNA. Automation of the individual steps of a crystallization experiment, from the preparation of crystallization cocktails for initial or optimization screens to the imaging of the experiments, has been the response to address this issue. Today, large high-throughput crystallization facilities, many of them open to the general user community, are capable of setting up thousands of crystallization trials per day. It is thus possible to test multiple constructs of each target for their ability to form crystals on a production-line basis. This has improved success rates and made crystallization much more convenient. High-throughput crystallization, however, cannot relieve users of the task of producing samples of high quality. Moreover, the time gained from eliminating manual preparations must now be invested in the careful evaluation of the increased number of experiments. The latter requires a sophisticated data and laboratory information-management system. A review of the current state of automation at the individual steps of crystallization with specific attention to the automation of optimization is given.

  2. Tunable plasmonic crystal

    Science.gov (United States)

    Dyer, Gregory Conrad; Shaner, Eric A.; Reno, John L.; Aizin, Gregory

    2015-08-11

    A tunable plasmonic crystal comprises several periods in a two-dimensional electron or hole gas plasmonic medium that is both extremely subwavelength (.about..lamda./100) and tunable through the application of voltages to metal electrodes. Tuning of the plasmonic crystal band edges can be realized in materials such as semiconductors and graphene to actively control the plasmonic crystal dispersion in the terahertz and infrared spectral regions. The tunable plasmonic crystal provides a useful degree of freedom for applications in slow light devices, voltage-tunable waveguides, filters, ultra-sensitive direct and heterodyne THz detectors, and THz oscillators.

  3. Influence of solvent evaporation rate on crystallization of poly ...

    Indian Academy of Sciences (India)

    by reading the corresponding temperature in the LM35 sen- sor, which was .... show any significant crystallization peaks in the XRD image. The films that are .... Scanning electron microscopy (SEM) images of SH70,. SH120 and SH130 are shown in figure 8. The SEM images reaffirm the formation of spherical grains at 70.

  4. Study of a large NaI(Tl) crystal

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar-Arevalo, A. [TRIUMF, 4004 Wesbrook Mall, Vancouver, B.C., V6T 2A3 (Canada); Aoki, M. [Physics Department, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Blecher, M. [Physics Department, Virginia Tech., Blacksburg, VA 24061 (United States); Bryman, D.A. [Department of Physics and Astronomy, University of British Columbia, Vancouver, B.C., V6T 1Z1 (Canada); Doria, L., E-mail: luca@triumf.c [TRIUMF, 4004 Wesbrook Mall, Vancouver, B.C., V6T 2A3 (Canada); Gumplinger, P. [TRIUMF, 4004 Wesbrook Mall, Vancouver, B.C., V6T 2A3 (Canada); Hussein, A. [University of Northern British Columbia, Prince George, B.C., V2N 4Z9 (Canada); Ito, N. [Physics Department, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Kettell, S. [Brookhaven National Laboratory, Upton, NY 11973-5000 (United States); Kurchaninov, L. [TRIUMF, 4004 Wesbrook Mall, Vancouver, B.C., V6T 2A3 (Canada); Littenberg, L. [Brookhaven National Laboratory, Upton, NY 11973-5000 (United States); Malbrunot, C. [Department of Physics and Astronomy, University of British Columbia, Vancouver, B.C., V6T 1Z1 (Canada); Marshall, G.M. [TRIUMF, 4004 Wesbrook Mall, Vancouver, B.C., V6T 2A3 (Canada); Numao, T., E-mail: toshio@triumf.c [TRIUMF, 4004 Wesbrook Mall, Vancouver, B.C., V6T 2A3 (Canada); Poutissou, R.; Sher, A. [TRIUMF, 4004 Wesbrook Mall, Vancouver, B.C., V6T 2A3 (Canada); Yamada, K. [Physics Department, Osaka University, Toyonaka, Osaka 560-0043 (Japan)

    2010-09-21

    Using a narrow band positron beam, the response of a large high-resolution NaI(Tl) crystal to an incident positron beam was measured. It was found that nuclear interactions cause the appearance of additional peaks in the low energy tail of the deposited energy spectrum.

  5. Study of a large NaI(Tl) crystal

    Science.gov (United States)

    Aguilar-Arevalo, A.; Aoki, M.; Blecher, M.; Bryman, D. A.; Doria, L.; Gumplinger, P.; Hussein, A.; Ito, N.; Kettell, S.; Kurchaninov, L.; Littenberg, L.; Malbrunot, C.; Marshall, G. M.; Numao, T.; Poutissou, R.; Sher, A.; Yamada, K.

    2010-09-01

    Using a narrow band positron beam, the response of a large high-resolution NaI(Tl) crystal to an incident positron beam was measured. It was found that nuclear interactions cause the appearance of additional peaks in the low energy tail of the deposited energy spectrum.

  6. Using PXRD to Investigate the Crystallization of Highly ...

    African Journals Online (AJOL)

    NICO

    emulsion made with 20 % PIPSA. These showed the unusual appearance of the higher temperature AN phase II during the crystallization process, in addition to the room temperature phase IV (Fig. 8). This was observed during the Rietveld refine- ment analysis where there were unmatched peaks present that were not part ...

  7. Far Infrared Photonic Crystals Operating in the Reststrahl Region

    National Research Council Canada - National Science Library

    Soref, Richard A; Qiang, Zexuan; Zhou, Weidong

    2007-01-01

    ...: GaP and Si, or GaAs and Ge, or AlAs and GaAs. The crystals operate in a wavelength range where the real refractive index of one material undergoes a major dispersion associated with the LO and TO phonon absorption peaks...

  8. Tunable Mach-Zehnder interferometer in a two-dimensional photonic crystal with liquid crystal infiltration

    Science.gov (United States)

    Chen, Xiyao; Dong, Xinyong; Hu, Juan Juan; Shum, Ping; Wang, Yufei; Qiu, Yishen; Lin, Guimin; Hong, Hailian

    2007-09-01

    A theoretical model of a tunable Mach-Zehnder interferometer (TMZI) constructed in a 2D photonic crystal is proposed. The 2D PhC consists of a square lattice of cylindric air holes in silicon. The TMZI includes two mirrors and two splitters. Lights propagate between them employing self-collimation effect. The two interferometer branches have different path lengths. Parts of the longer branch are infiltrated with a kind of liquid crystal (LC) whose ordinary and extraordinary refractive indices are 1.522 and 1.706, respectively. The transmission spectra at two MZI output ports are in the shape of sinusoidal curves and have a uniform peak spacing 0.0017c/a in the frequency range from 0.26c/a to 0.27c/a. When the effective refractive index n eff of the liquid crystal is increased from 1.522 to 1.706, the peaks shift to the lower frequencies over 0.0017c/a while the peak spacing is almost kept unchanged. So this TMZI can work as a tunble power splitter or an optical switch. For the central operating wavelength around 1550nm, its dimensions are only about tens of microns. So this device may be applied to photonic integrated circuits.

  9. Peak broadening in paper chromatography and related techniques : III. Peak broadening in thin-layer chromatography on cellulose powder

    NARCIS (Netherlands)

    Ligny, C.L. de; Remijnse, A.G.

    1968-01-01

    The mechanism of peak broadening in thin-layer chromatography on cellulose powder was investigated by comparing the peak widths obtained in chromatography with those caused only by diffusion in the cellulose powder, for a set of amino acids of widely differing RF values and six kinds of cellulose

  10. Evaluation of different time domain peak models using extreme learning machine-based peak detection for EEG signal.

    Science.gov (United States)

    Adam, Asrul; Ibrahim, Zuwairie; Mokhtar, Norrima; Shapiai, Mohd Ibrahim; Cumming, Paul; Mubin, Marizan

    2016-01-01

    Various peak models have been introduced to detect and analyze peaks in the time domain analysis of electroencephalogram (EEG) signals. In general, peak model in the time domain analysis consists of a set of signal parameters, such as amplitude, width, and slope. Models including those proposed by Dumpala, Acir, Liu, and Dingle are routinely used to detect peaks in EEG signals acquired in clinical studies of epilepsy or eye blink. The optimal peak model is the most reliable peak detection performance in a particular application. A fair measure of performance of different models requires a common and unbiased platform. In this study, we evaluate the performance of the four different peak models using the extreme learning machine (ELM)-based peak detection algorithm. We found that the Dingle model gave the best performance, with 72 % accuracy in the analysis of real EEG data. Statistical analysis conferred that the Dingle model afforded significantly better mean testing accuracy than did the Acir and Liu models, which were in the range 37-52 %. Meanwhile, the Dingle model has no significant difference compared to Dumpala model.

  11. Generation of sub-nanosecond pulses using peaking capacitor

    Directory of Open Access Journals (Sweden)

    Madhu Palati

    2017-05-01

    Full Text Available This paper discusses the analysis, simulation and design of a peaking circuit comprising of a peaking capacitor, spark gap and load circuit. The peaking circuit is used along with a 200 kV, 20 J Marx generator for generation of sub-nanosecond pulses. A high pressure chamber to accommodate the peaking circuit was designed and fabricated and tested upto a pressure of 70 kg/cm2. Total estimated values of the capacitance and inductance of the peaking circuit are 10 pF and 72 nH respectively. At full charging voltage, the peaking capacitor gets charged to a peak voltage of 394.6 kV in 15 ns. The output switch is closed at this instant. From Analysis & Simulation, the output current & rise time (with a matched load of 85 Ω are 2.53 kA and 0.62 ns.

  12. Core fueling to produce peaked density profiles in large tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Mikkelsen, D.R.; McGuire, K.M.; Schmidt, G.L.; Zweben, S.J. [Princeton Univ., NJ (United States). Plasma Physics Lab.; Attenberger, S.E.; Houlberg, W.A.; Milora, S.L. [Oak Ridge National Lab., TN (United States)

    1994-06-01

    Peaking the density profile increases the usable bootstrap current and the average fusion power density; this could reduce the current drive power and increase the net output of power producing tokamaks. The use of neutral beams and pellet injection to produce peaked density profiles is assessed. We show that with radially ``hollow`` diffusivity profiles (and no particle pinch) moderately peaked density profiles can be produced by particle source profiles which are peaked off-axis. The fueling penetration requirements can therefore be relaxed and this greatly improves the feasibility of generating peaked density profiles in large tokamaks. In particular, neutral beam fueling does not require MeV particle energy. Even with beam voltages of {approximately}200 keV, however, exceptionally good particle confinement, {tau}{sub p} {much_gt} {tau}{sub E} is required to achieve net electrical power generation. In system with no power production requirement (e.g., neutron sources) neutral beam fueling should be capable of producing peaked density profiles in devices as large as ITER. Fueling systems with low energy cost per particle (such as cryogenic pellet injection) must be used in power producing tokamaks when {tau}{sub p} {approximately} {tau}{sub E}. Simulations with pellet injection speeds of 7 km/sec show the peaking factor, n{sub eo}/{l_angle}n{sub e}{r_angle}, approaching 2.

  13. VO2peak prediction and exercise prescription for pregnant women.

    Science.gov (United States)

    Mottola, Michelle F; Davenport, Margie H; Brun, Chantale R; Inglis, Stuart D; Charlesworth, Sarah; Sopper, Maggie M

    2006-08-01

    The present study was designed to develop and validate a prediction equation for peak oxygen consumption VO2peak) using a progressive treadmill test and to refine the current target HR exercise guidelines for pregnancy (PARmed-X for Pregnancy). One hundred fifty-six women between 16 and 22 wk of gestation performed the test to volitional fatigue (peak exercise test). Data from every fourth subject were used to form the cross-validation group. The women were separated into two age groups; 20-29 (N = 60) and 30-39 (N = 96) yr of age and then further separated into fit (VO2peak at the top 25th percentile), unfit (VO2peak at the bottom 25th percentile), and active (between these two ranges). HR and VO2peak values were used in the regression equation to predict target HR ranges at 60 and 80% VO2peak. The prediction equation (R2 = 0.72, R2adjusted = 0.71 and SEE = 2.7) was compared with cross validation (N = 39; P = 0.78). Fit women had a VO2peak > or = 27.2 mL.kg(-1).min(-1) and > or = 26.1 mL.kg.min for ages 20-29 and 30-39 yr, respectively, representing the top 25th percentile. Unfit women had a VO2peak of pregnant women using a progressive treadmill exercise test. The defined target HR zones based on age and the appropriate fitness levels can be used for exercise prescription in healthy pregnant women.

  14. Understanding Human Motion Skill with Peak Timing Synergy

    Science.gov (United States)

    Ueno, Ken; Furukawa, Koichi

    The careful observation of motion phenomena is important in understanding the skillful human motion. However, this is a difficult task due to the complexities in timing when dealing with the skilful control of anatomical structures. To investigate the dexterity of human motion, we decided to concentrate on timing with respect to motion, and we have proposed a method to extract the peak timing synergy from multivariate motion data. The peak timing synergy is defined as a frequent ordered graph with time stamps, which has nodes consisting of turning points in motion waveforms. A proposed algorithm, PRESTO automatically extracts the peak timing synergy. PRESTO comprises the following 3 processes: (1) detecting peak sequences with polygonal approximation; (2) generating peak-event sequences; and (3) finding frequent peak-event sequences using a sequential pattern mining method, generalized sequential patterns (GSP). Here, we measured right arm motion during the task of cello bowing and prepared a data set of the right shoulder and arm motion. We successfully extracted the peak timing synergy on cello bowing data set using the PRESTO algorithm, which consisted of common skills among cellists and personal skill differences. To evaluate the sequential pattern mining algorithm GSP in PRESTO, we compared the peak timing synergy by using GSP algorithm and the one by using filtering by reciprocal voting (FRV) algorithm as a non time-series method. We found that the support is 95 - 100% in GSP, while 83 - 96% in FRV and that the results by GSP are better than the one by FRV in the reproducibility of human motion. Therefore we show that sequential pattern mining approach is more effective to extract the peak timing synergy than non-time series analysis approach.

  15. Incorporation of topside half peak density anchor point in IRI

    Science.gov (United States)

    Gulyaeva, T. L.

    2004-01-01

    The F2 layer peak density ( N mF2) and height ( h mF2) are used by the International Reference Ionosphere as anchor point fitted by the electron density profile. The shape of the bottomside Ne( h) distribution is formulated with the help of profile sub-peak semithickness taken as a distance between the peak height and the bottom half-peak density height h05 bot. In a similar manner relevant procedure allowing to fit IRI topside electron density profile to additional anchor point — the half-peak density height h05 top at electron density equal to 0.5 × N mF2 above the F2 peak is included in the IRI ionosphere-plasmasphere model. Two types of :input are used with IRI code for 14 intense magnetic storms during 1999-2003: ionosonde derived data ( ƒoF2, h mF2 and hO5 bot) and Global Positioning System (GPS)-based total electron content (TEC) observation. It is shown that topside half-peak height h05 top and topside scale height can be inferred from the GPS-TEC measurements with an iteration procedure applied to IRI profiling algorithm. The proposed technique is validated with incoherent scatter ionospheric electron content, ITEC, provided by EISCAT electron density profiles. Good correlation is obtained between the height h05 top and the equivalent slab thickness τ, representing ratio of TEC to N mF2. This approach allowed us to reveal a highly variable topside scale height for intense space weather storms at mid latitudes with peaks up to 800 km during the peaks of magnetic activity.

  16. Superluminal pulse propagation through one-dimensional photonic crystals with a dispersive defect.

    Science.gov (United States)

    Liu, Nian-Hua; Zhu, Shi-Yao; Chen, Hong; Wu, Xiang

    2002-04-01

    The propagation of a pulse through one-dimensional photonic crystals that contain a dispersive and absorptive defect layer doped with two-level atoms is discussed. The dynamical evolution of the pulse inside the photonic crystal is presented. Superluminal negative group velocity (the peak appears at the exit end before it reaches the input end) is discovered. Although the group velocity is larger than c and even negative, the velocity of energy propagation never exceeds the vacuum light speed. The appearance of the superluminal advance or subluminal delay of the pulse peak inside the photonic crystal or at the exit end is due to the wave interference from Bragg reflections.

  17. National energy peak leveling program (NEPLP). Final report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-12-01

    This three-volume report is responsive to the requirements of Contract E (04-3)-1152 to provide a detailed methodology, to include management, technology, and socio-economic aspects, of a voluntary community program of computer-assisted peak load leveling and energy conservation in commercial community facilities. The demonstration project established proof-of-concept in reducing the kW-demand peak by the unofficial goal of 10%, with concurrent kWh savings. This section of the three volume report is a final report appendix with information on the National Energy Peak Leveling Program (NEPLP).

  18. Determination of kinetic energy release from metastable peak widths

    DEFF Research Database (Denmark)

    Petersen, Allan Christian; Sølling, Theis I.

    2017-01-01

    The kinetic energy that is released upon bond rupture is often represented as T1/2. A value that is derived from the FWHM of a fragment peak by the use of two different conversion formulas. The choice of formula depends on whether the peak is recorded by scanning a magnetic sector...... that are obtained from magnet scans compared to the peaks that are obtained by scanning an electrostatic analyzer. The E scans (MIKE experiments) give rise to the same values for both of the employed mass spectrometers. The results are explained in terms of energy defocusing when the reactions take place too far...

  19. Manipulation of colloidal crystallization

    NARCIS (Netherlands)

    Vermolen, E.C.M.

    2008-01-01

    Colloidal particles (approximately a micrometer in diameter) that are dispersed in a fluid, behave thermodynamically similar to atoms and molecules: at low concentrations they form a fluid, while at high concentrations they can crystallize into a colloidal crystal to gain entropy. The analogy with

  20. Thermotropic Ionic Liquid Crystals

    OpenAIRE

    Sabine Laschat; Axenov, Kirill V

    2011-01-01

    The last five years’ achievements in the synthesis and investigation of thermotropic ionic liquid crystals are reviewed. The present review describes the mesomorphic properties displayed by organic, as well as metal-containing ionic mesogens. In addition, a short overview on the ionic polymer and self-assembled liquid crystals is given. Potential and actual applications of ionic mesogens are also discussed.

  1. Photonic crystal fibers

    DEFF Research Database (Denmark)

    Lægsgaard, Jesper; Hansen, K P; Nielsen, M D

    2003-01-01

    Photonic crystal fibers having a complex microstructure in the transverse plane constitute a new and promising class of optical fibers. Such fibers can either guide light through total internal reflection or the photonic bandgap effect, In this paper, we review the different types and applications...... of photonic crystal fibers with particular emphasis on recent advances in the field....

  2. Crystals in the LHC

    CERN Multimedia

    Antonella Del Rosso

    2012-01-01

    Bent crystals can be used to deflect charged particle beams. Their use in high-energy accelerators has been investigated for almost 40 years. Recently, a bent crystal was irradiated for the first time in the HiRadMat facility with an extreme particle flux, which crystals would have to withstand in the LHC. The results were very encouraging and confirmed that this technology could play a major role in increasing the beam collimation performance in future upgrades of the machine.   UA9 bent crystal tested with a laser. Charged particles interacting with a bent crystal can be trapped in channelling states and deflected by the atomic planes of the crystal lattice (see box). The use of bent crystals for beam manipulation in particle accelerators is a concept that has been well-assessed. Over the last three decades, a large number of experimental findings have contributed to furthering our knowledge and improving our ability to control crystal-particle interactions. In modern hadron colliders, su...

  3. Assessment of microarchitecture and crystal structure of hydroxyapatite in osteoporosis

    Directory of Open Access Journals (Sweden)

    Zairin Noor

    2016-02-01

    Full Text Available Osteoporosis is characterized by lower bone mineral density (BMD and microarchitectural degeneration, which tends to increase bone fragility and fracture risk. Bone microstructure depends on interactions between the mineral atoms, which may perform substitution or incorporation into bone crystals, and may dynamically take over the function of calcium or may become a complementary part. The mineral atoms may also become a composite in the hydroxyapatite crystals. The aim of this study was to find an association between the bone microstructure and hydoxyapatite crystal structure in osteoporosis, in comparison to normal bone. The subjects of this study were surgery patients at the Department of Orthopedics of Ulin General Hospital in Banjarmasin and other centers. Inclusion criteria consisted of the presence of fracture of trabecular bone, normal or osteoporotic BMD values, and no past history of chronic disease. Bone was obtained from fracture patients during surgery. The characteristics of the hydroxyapatite crystals were analyzed by X-ray diffraction (XRD and the microarchitecture by scanning electron microscopy (SEM. SEM showed degeneration of the microarchitecture of osteoporotic bone, in comparison with normal bone. On XRD there was a peak of hydoxyapatite crystals only and no other crystal phases. Diffraction patterns showed a larger crystal size in osteoporotic bone as compared to normal bone, indicating higher porosity. It may be concluded that there is a difference in crystal size and morphologic distribution of hydoxyapatite in osteoporotic bone, determining bone microarchitecture.

  4. Assessment of microarchitecture and crystal structure of hydroxyapatite in osteoporosis

    Directory of Open Access Journals (Sweden)

    Zairin Noor

    2011-04-01

    Full Text Available Osteoporosis is characterized by lower bone mineral density (BMD and microarchitectural degeneration, which tends to increase bone fragility and fracture risk. Bone microstructure depends on interactions between the mineral atoms, which may perform substitution or incorporation into bone crystals, and may dynamically take over the function of calcium or may become a complementary part. The mineral atoms may also become a composite in the hydroxyapatite crystals. The aim of this study was to find an association between the bone microstructure and hydoxyapatite crystal structure in osteoporosis, in comparison to normal bone. The subjects of this study were surgery patients at the Department of Orthopedics of Ulin General Hospital in Banjarmasin and other centers. Inclusion criteria consisted of the presence of fracture of trabecular bone, normal or osteoporotic BMD values, and no past history of chronic disease. Bone was obtained from fracture patients during surgery. The characteristics of the hydroxyapatite crystals were analyzed by X-ray diffraction (XRD and the microarchitecture by scanning electron microscopy (SEM. SEM showed degeneration of the microarchitecture of osteoporotic bone, in comparison with normal bone. On XRD there was a peak of hydoxyapatite crystals only and no other crystal phases. Diffraction patterns showed a larger crystal size in osteoporotic bone as compared to normal bone, indicating higher porosity. It may be concluded that there is a difference in crystal size and morphologic distribution of hydoxyapatite in osteoporotic bone, determining bone microarchitecture.

  5. Optically Anomalous Crystals

    CERN Document Server

    Shtukenberg, Alexander; Kahr, Bart

    2007-01-01

    Optical anomalies in crystals are puzzles that collectively constituted the greatest unsolved problems in crystallography in the 19th Century. The most common anomaly is a discrepancy between a crystal’s symmetry as determined by its shape or by X-ray analysis, and that determined by monitoring the polarization state of traversing light. These discrepancies were perceived as a great impediment to the development of the sciences of crystals on the basis of Curie’s Symmetry Principle, the grand organizing idea in the physical sciences to emerge in the latter half of the 19th Century. Optically Anomalous Crystals begins with an historical introduction covering the contributions of Brewster, Biot, Mallard, Brauns, Tamman, and many other distinguished crystallographers. From this follows a tutorial in crystal optics. Further chapters discuss the two main mechanisms of optical dissymmetry: 1. the piezo-optic effect, and 2. the kinetic ordering of atoms. The text then tackles complex, inhomogeneous crystals, and...

  6. Progress on photonic crystals

    CERN Document Server

    Lecoq, P; Gundacker, S; Hillemanns, H; Jarron, P; Knapitsch, A; Leclercq, J L; Letartre, X; Meyer, T; Pauwels, K; Powolny, F; Seassal, C

    2010-01-01

    The renewal of interest for Time of Flight Positron Emission Tomography (TOF PET) has highlighted the need for increasing the light output of scintillating crystals and in particular for improving the light extraction from materials with a high index of refraction. One possible solution to overcome the problem of total internal reflection and light losses resulting from multiple bouncing within the crystal is to improve the light extraction efficiency at the crystal/photodetector interface by means of photonic crystals, i.e. media with a periodic modulation of the dielectric constant at the wavelength scale. After a short reminder of the underlying principles this contribution proposes to present the very encouraging results we have recently obtained on LYSO pixels and the perspectives on other crystals such as BGO, LuYAP and LuAG. These results confirm the impressive predictions from our previously published Monte Carlo simulations. A detailed description of the sample preparation procedure is given as well ...

  7. Crystallization phenomena of isotactic polystyrene

    NARCIS (Netherlands)

    Lemstra, Peter Jan

    1975-01-01

    In this thesis the crystallization behavior of isotactic polystyrene has been described. The kinetics of the crystallization process and the crystalline structure were studied both for crystallization in the bulk and from dilute solutions. ... Zie Summary

  8. Energy loss minimization through peak shaving using energy storage

    Directory of Open Access Journals (Sweden)

    Vaiju Kalkhambkar

    2016-09-01

    Full Text Available This paper presents an optimal placement methodology of energy storage to improve energy loss minimization through peak shaving in the presence of renewable distributed generation. Storage sizing is modelled by considering the load profile and desired peak shaving. This storage is suitably divided into multiple storage units and optimally allocated at multiple sites with suitable charge discharge strategy. Thus the peak shaving for maximum loss reduction is explored here. Renewable distributed generation (RDG is modelled based on the seasonal variations of renewable resources e.g., solar or wind and these RDGs are placed at suitable locations. A high-performance Grey Wolf Optimization (GWO algorithm is applied to the proposed methodology. The results are compared with the well-known genetic algorithm. The proposed methodology is illustrated by various case studies on a 34-bus test system. Significant loss minimization is obtained by optimal location of multiple energy storage units through peak shaving.

  9. Bedrock Geologic Map of the Jay Peak, VT Quadrangle

    Data.gov (United States)

    Vermont Center for Geographic Information — Digital data from VG99-1 Compilation bedrock geologic map of the Jay Peak quadrangle, Compiled by B. Doolan, 1999: VGS Open-File Report VG99-1, 1 plate, scale...

  10. Sakste vara: Eesti peaks õppima Poola kogemusest / Helle Kalda

    Index Scriptorium Estoniae

    Kalda, Helle, 1950-

    2009-01-01

    Poolas on jõutud seisukohale, et Poola riik ei pea Saksamaale ümberasunutele vara tagastama. Riigikogu liikme arvates peaks Eesti mitte kandma kulutusi, vaid hoopis küsima Saksamaalt kompensatsiooni seoses baltisakslaste varaga kantavate kulutuste katteks

  11. Audible thunder characteristic and the relation between peak ...

    Indian Academy of Sciences (India)

    Audible thunder characteristic and the relation between peak frequency and lightning parameters ... In recent summers, some natural lightning optical spectra and audible thunder signals were observed. ... School of Mathematics, Physics and Software Engineering, Lanzhou Jiaotong University, Lanzhou 730 070, China.

  12. Brian Eno Hollandi Festivali peakülaliseks

    Index Scriptorium Estoniae

    1999-01-01

    Inglise helilooja, videokunstnik ja muusikaprodutsent Brian Eno on 5.-26. juunini Amsterdamis toimuva avangardse Hollandi Festivali peakülaline, kelle videoinstallatsioon seatakse üles Stedelijki Muuseumis. Festivali programmist

  13. variant formula for predicting peak expiratory flow rate in pregnant ...

    African Journals Online (AJOL)

    DR. AMINU

    Accepted: November, 2009. VARIANT FORMULA FOR PREDICTING PEAK EXPIRATORY FLOW RATE IN. PREGNANT WOMEN IN KURA LOCAL GOVERNMENT AREA, KANO STATE,. NIGERIA. A. I. Salisu. Department of Human Physiology, Faculty of Medicine, Bayero University, Kano salisahmedibrahim@yahoo.co.uk;.

  14. Corona discharge ionization of paracetamol molecule: Peak assignment

    Science.gov (United States)

    Bahrami, H.; Farrokhpour, H.

    2015-01-01

    Ionization of paracetamol was investigated using ion mobility spectrometry equipped with a corona discharge ionization source. The measurements were performed in the positive ion mode and three peaks were observed in the ion mobility spectrum. Experimental evidence and theoretical calculations were used to correlate the peaks to related ionic species of paracetamol. Two peaks were attributed to protonated isomers of paracetamol and the other peak was attributed to paracetamol fragment ions formed by dissociation of the N-C bond after protonation of the nitrogen atom. It was observed that three sites of paracetamol compete for protonation and their relative intensities, depending on the sample concentration. The ratio of ion products could be predicted from the internal proton affinity of the protonation sites at each concentration.

  15. Reducing Electricity Demand Peaks by Scheduling Home Appliances Usage

    DEFF Research Database (Denmark)

    Rossello Busquet, Ana; Kardaras, Georgios; Iversen, Villy Bæk

    2011-01-01

    Nowadays there is a tendency to consume electricity during the same period of the day leading to demand peaks. Regular energy consumption habits lead to demand peaks at specific temporal intervals, because users consume power at the same time. In order to avoid demand peaks, users’ appliances...... should consume electricity in a more temporarily distributed way. A new methodology to schedule the usage of home appliances is proposed and analyzed in this paper. The main concept behind this approach is the aggregation of home appliances into priority classes and the definition of a maximum power...... consumption limit, which is not allowed to be exceeded during peak hours. The scenario simulated describes a modern household, where the electrical devices are classified in low and high priority groups. The high priority devices are always granted power in order to operate without temporal restrictions...

  16. Desert Peak East Enhanced Geothermal Systems (EGS) Project

    Energy Technology Data Exchange (ETDEWEB)

    Zemach, Ezra [Ormat Technologies Inc., Reno, NV (United States); Drakos, Peter [Ormat Technologies Inc., Reno, NV (United States); Spielman, Paul [Ormat Technologies Inc., Reno, NV (United States); Akerley, John [Ormat Technologies Inc., Reno, NV (United States)

    2013-09-30

    This manuscript is a draft to replaced with a final version at a later date TBD. A summary of activities pertaining to the Desert Peak EGS project including the planning and resulting stimulation activities.

  17. 1.55 Micron High Peak Power Fiber Amplifier Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this proposal, we propose to demonstrate and build a 1.55 micron single frequency high energy and high peak power fiber amplifier by developing an innovative...

  18. General Merrill A. McPeak: An Effective Change Agent?

    National Research Council Canada - National Science Library

    Hopper, Tim

    1997-01-01

    .... It also looks at the role he played as a change agent. Current models of how organizational change should be implemented are compared to how General McPeak implemented his organizational change...

  19. Effects of equipment and technique on peak flow measurements

    Directory of Open Access Journals (Sweden)

    O'Driscoll B Ronan

    2006-06-01

    Full Text Available Abstract Background Different lung function equipment and different respiratory manoeuvres may produce different Peak Expiratory Flow (PEF results. Although the PEF is the most common lung function test, there have been few studies of these effects and no previous study has evaluated both factors in a single group of patients. Methods We studied 36 subjects (PEF range 80–570 l/min. All patients recorded PEF measurements using a short rapid expiration following maximal inspiration (PEF technique or a forced maximal expiration to residual volume (FVC technique. Measurements were made using a Wright's peak flow meter, a turbine spirometer and a Fleisch pneumotachograph spirometer. Results The mean PEF was 8.7% higher when the PEF technique was used (compared with FVC technique, p Conclusion Peak flow measurements are affected by the instruction given and by the device and Peak Flow scale used. Patient management decisions should not be based on PEF measurement made on different instruments.

  20. Observation of Algebraic Decay of Positional Order in a Smectic Liquid Crystal

    DEFF Research Database (Denmark)

    Als-Nielsen, Jens Aage; Litster, J. D.; Birgeneau, R. J.

    1980-01-01

    A smectic-A liquid crystal in three dimensions has been predicted to exhibit algebraic decay of the layer correlations rather than true long-range order. As a consequence, the smectic Bragg peaks are expected to be power-law singularities of the form q∥-2+η and q⊥-4+2η, where ∥(⊥) is along...... (perpendicular to) the smectic density wave vector direction, rather than δ function peaks. Observation of these phenomena requires very high instrumental resolution together with a resolution function with wings which drop off much more rapidly than q∥-2(q⊥-4). We show that these requirements may be met...... by using a three crystal x-ray spectrometer with multiple-reflection channel cut crystals as monochromator and analyzer. We find that the smectic-A Bragg peaks observed in the liquid-crystal octyloxy-cyanobiphenyl are indeed consistent with the predicted power-law singularity form. Furthermore...

  1. Crystal growth, electronic structure and luminescence properties of Nb/Yb co-doped RbTiOPO4 crystals

    Science.gov (United States)

    Liu, Jian; Li, Ziqing; Zhu, Pengfei; Duan, Xiulan

    2018-01-01

    Nb/Yb co-doped RbTiOPO4 (RTP) crystals were successfully grown by a top-seeded solution growth method from two different kinds of flux systems. 5%Nb/3%Yb: RTP crystal with more transparency was obtained from the mixed solvent containing MoO3. The chemical composition was analyzed by Electron Probe Microanalyzer (EPMA), and the result indicated that co-doping of Nb and Yb into RTP can greatly increase the concentration of Yb in RTP crystal. The addition of MoO3 into self-flux system can improve the quality of as-grown crystals, but it is not helpful to introduce Yb into crystal. The electronic structures of Nb/Yb: RTP crystals were analyzed using X-ray photoelectron spectra (XPS). The results show that the binding energy difference between O 1s and P 2p levels (ΔBE (O-P)) increases firstly with the increase of Yb content, and then decreases with Nb content increasing, which is associated with the covalency change of O-P bonds in crystals. However, the doping has little influence on the chemical bond properties of O-Ti. The FL spectra of Nb/Yb: RbTiOPO4 crystals were also analyzed, and five emission peaks characteristic of Yb3+ ions were observed.

  2. Peak effect at microwave frequencies in swift heavy ion irradiated ...

    Indian Academy of Sciences (India)

    disorder, results in a peak in the critical current density Jc near Tc (Hc2), known as 'peak effect' (PE). The earliest understanding of the PE [4,5] is based on the collective pinning scenario that involves the softening of the elastic moduli (c66 and c44) of the flux line lattice. (FLL) near Tc (Hc2) where the superconducting order ...

  3. Peak Strain in Regressing Finocyl Port Propellant Grainsunder Pressure Loading

    OpenAIRE

    Himanshu Shekhar

    2007-01-01

    Finite element analysis (FEM) has been conducted for case-bonded finocyl port propellantcross section under pressure loading conditions during burning. Peak strain is found todecrease in course of burning, hence, analysis of any intermediate configuration in courseof burning is not required for assessing margin of safety in finocyl port propellant grains.The Power Law proposed1 has also been used to predict peak strain. Variation in strainsobtained by FEM and using the Power Law is found to b...

  4. Converter for Measurement of non-sinusoidal current peak value

    DEFF Research Database (Denmark)

    Butvin, P.; Nielsen, Otto V; Brauer, Peter

    1997-01-01

    A linear-response toroid with core wound of rapidly quenched soft magnetic metallic ribbon and fitted with two windings is used to enable correct measurement of mean peak value of non-sinusoidal and not noise-free alternating current.......A linear-response toroid with core wound of rapidly quenched soft magnetic metallic ribbon and fitted with two windings is used to enable correct measurement of mean peak value of non-sinusoidal and not noise-free alternating current....

  5. Improvements to science operations at Kitt Peak National Observatory

    Science.gov (United States)

    Bohannan, Bruce

    1998-07-01

    In recent years Kitt Peak National Observatory has undertaken a number of innovative projects to optimize science operations with the suite of telescopes we operate on Kitt Peak, Arizona. Changing scientific requirements and expectations of our users, evolving technology and declining budgets have motivated the changes. The operations improvements have included telescope performance enhancements--with the focus on the Mayall 4-m--modes of observing and scheduling, telescope control and observing systems, planning and communication, and data archiving.

  6. Effects of oral contraceptives on peak exercise capacity.

    Science.gov (United States)

    Casazza, Gretchen A; Suh, Sang-Hoon; Miller, Benjamin F; Navazio, Franco M; Brooks, George A

    2002-11-01

    We examined the effects of menstrual cycle phase and oral contraceptive (OC) use on peak oxygen consumption (VO(2 peak)). Six moderately active, eumenorrheic women (25.5 +/- 1.5 yr) were studied before and after 4 mo of OC. Subjects were tested during the follicular and luteal phases before OC and the inactive and high-dose phases after OC. Before OC, there were no significant differences between the follicular and luteal phases in any of the variables studied. There were also no differences between the inactive and high-dose phases. Dietary composition, exercise patterns, and peak heart rate, minute ventilation, and respiratory exchange ratio did not change with OC use. However, OC use significantly (P VO(2 peak) (-11%, 2.53 +/- 0.21 to 2.25 +/- 0.18 l/min). In conclusion, 1) endogenous ovarian steroids have little effect on VO(2 peak), but 2) the exogenous ovarian steroids in OC decrease peak exercise capacity in moderately physically active young women.

  7. Peaking of world oil production: Impacts, mitigation, & risk management

    Energy Technology Data Exchange (ETDEWEB)

    Hirsch, R.L. (SAIC); Bezdek, Roger (MISI); Wendling, Robert (MISI)

    2005-02-01

    The peaking of world oil production presents the U.S. and the world with an unprecedented risk management problem. As peaking is approached, liquid fuel prices and price volatility will increase dramatically, and, without timely mitigation, the economic, social, and political costs will be unprecedented. Viable mitigation options exist on both the supply and demand sides, but to have substantial impact, they must be initiated more than a decade in advance of peaking.... The purpose of this analysis was to identify the critical issues surrounding the occurrence and mitigation of world oil production peaking. We simplified many of the complexities in an effort to provide a transparent analysis. Nevertheless, our study is neither simple nor brief. We recognize that when oil prices escalate dramatically, there will be demand and economic impacts that will alter our simplified assumptions. Consideration of those feedbacks will be a daunting task but one that should be undertaken. Our aim in this study is to-- • Summarize the difficulties of oil production forecasting; • Identify the fundamentals that show why world oil production peaking is such a unique challenge; • Show why mitigation will take a decade or more of intense effort; • Examine the potential economic effects of oil peaking; • Describe what might be accomplished under three example mitigation scenarios. • Stimulate serious discussion of the problem, suggest more definitive studies, and engender interest in timely action to mitigate its impacts.

  8. Non-Gaussian bias: insights from discrete density peaks

    Energy Technology Data Exchange (ETDEWEB)

    Desjacques, Vincent; Riotto, Antonio [Département de Physique Théorique and Center for Astroparticle Physics, Université de Genève, CH-1211 Genève (Switzerland); Gong, Jinn-Ouk, E-mail: Vincent.Desjacques@unige.ch, E-mail: jinn-ouk.gong@apctp.org, E-mail: Antonio.Riotto@unige.ch [Theory Division, CERN, CH-1211 Genève 23 (Switzerland)

    2013-09-01

    Corrections induced by primordial non-Gaussianity to the linear halo bias can be computed from a peak-background split or the widespread local bias model. However, numerical simulations clearly support the prediction of the former, in which the non-Gaussian amplitude is proportional to the linear halo bias. To understand better the reasons behind the failure of standard Lagrangian local bias, in which the halo overdensity is a function of the local mass overdensity only, we explore the effect of a primordial bispectrum on the 2-point correlation of discrete density peaks. We show that the effective local bias expansion to peak clustering vastly simplifies the calculation. We generalize this approach to excursion set peaks and demonstrate that the resulting non-Gaussian amplitude, which is a weighted sum of quadratic bias factors, precisely agrees with the peak-background split expectation, which is a logarithmic derivative of the halo mass function with respect to the normalisation amplitude. We point out that statistics of thresholded regions can be computed using the same formalism. Our results suggest that halo clustering statistics can be modelled consistently (in the sense that the Gaussian and non-Gaussian bias factors agree with peak-background split expectations) from a Lagrangian bias relation only if the latter is specified as a set of constraints imposed on the linear density field. This is clearly not the case of standard Lagrangian local bias. Therefore, one is led to consider additional variables beyond the local mass overdensity.

  9. Peak bone mass and affecting factors in Korean women.

    Science.gov (United States)

    Lim, S K; Lee, N H; Lee, J H; Choi, M S; Chung, Y S; Ahn, K J; Lee, H C; Huh, K B

    1993-03-01

    Maximizing peak bone mass is advocated as a way to prevent osteoporosis. To evaluate the peak bone mass and the affecting factors in Korean women, we analyzed bone stiffness in 116 middle school students, 118 high school students and 115 female college students by using the Achilles densitometer (Lunar Corporation). Peak bone stiffness of Korean women was relatively lower than that of white women (94% of white women) and a rapid rise of bone stiffness was observed in those subjects 3-4 years after menarche. In adolescent females without menstruation, the bone stiffness was lower than that of adolescent girls with menstruation. The factors affecting the peak bone mass was similar to the risk factors of post menopausal osteoporosis: menstruation status, calcium intake and physical activity. The amount of calcium intake in Korean girls at the critical age (3-4 years after menarche) was lower than the RDA (requirement of daily allowance) at this age. To improve any program aimed at maximizing peak bone mass, further intensive study will be required to evaluate some other common factors affecting peak bone mass in Korean.

  10. Quartz crystal growth

    Science.gov (United States)

    Baughman, Richard J.

    1992-01-01

    A process for growing single crystals from an amorphous substance that can undergo phase transformation to the crystalline state in an appropriate solvent. The process is carried out in an autoclave having a lower dissolution zone and an upper crystallization zone between which a temperature differential (.DELTA.T) is maintained at all times. The apparatus loaded with the substance, solvent, and seed crystals is heated slowly maintaining a very low .DELTA.T between the warmer lower zone and cooler upper zone until the amorphous substance is transformed to the crystalline state in the lower zone. The heating rate is then increased to maintain a large .DELTA.T sufficient to increase material transport between the zones and rapid crystallization. .alpha.-Quartz single crystal can thus be made from fused quartz in caustic solvent by heating to 350.degree. C. stepwise with a .DELTA.T of 0.25.degree.-3.degree. C., increasing the .DELTA.T to about 50.degree. C. after the fused quartz has crystallized, and maintaining these conditions until crystal growth in the upper zone is completed.

  11. Crystals in light.

    Science.gov (United States)

    Kahr, Bart; Freudenthal, John; Gunn, Erica

    2010-05-18

    We have made images of crystals illuminated with polarized light for almost two decades. Early on, we abandoned photosensitive chemicals in favor of digital electrophotometry with all of the attendant advantages of quantitative intensity data. Accurate intensities are a boon because they can be used to analytically discriminate small effects in the presence of larger ones. The change in the form of our data followed camera technology that transformed picture taking the world over. Ironically, exposures in early photographs were presumed to correlate simply with light intensity, raising the hope that photography would replace sensorial interpretation with mechanical objectivity and supplant the art of visual photometry. This was only true in part. Quantitative imaging accurate enough to render the separation of crystalloptical quantities had to await the invention of the solid-state camera. Many pioneers in crystal optics were also major figures in the early history of photography. We draw out the union of optical crystallography and photography because the tree that connects the inventors of photography is a structure unmatched for organizing our work during the past 20 years, not to mention that silver halide crystallites used in chemical photography are among the most consequential "crystals in light", underscoring our title. We emphasize crystals that have acquired optical properties such as linear birefringence, linear dichroism, circular birefringence, and circular dichroism, during growth from solution. Other crystalloptical effects were discovered that are unique to curiously dissymmetric crystals containing embedded oscillators. In the aggregate, dyed crystals constitute a generalization of single crystal matrix isolation. Simple crystals provided kinetic stability to include guests such as proteins or molecules in excited states. Molecular lifetimes were extended for the preparation of laser gain media and for the study of the photodynamics of single

  12. Magnetic ions in crystals

    CERN Document Server

    Stevens, K W

    2014-01-01

    There have been many demonstrations, particularly for magnetic impurity ions in crystals, that spin-Hamiltonians are able to account for a wide range of experimental results in terms of much smaller numbers of parameters. Yet they were originally derived from crystal field theory, which contains a logical flaw; electrons on the magnetic ions are distinguished from those on the ligands. Thus there is a challenge: to replace crystal field theory with one of equal or greater predictive power that is based on a surer footing. The theory developed in this book begins with a generic Hamiltonian, on

  13. Raman scattering in crystals

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, D.F.

    1988-09-30

    A tutorial presentation is given of Raman scattering in crystals. The physical concepts are emphasized rather than the detailed mathematical formalism. Starting with an introduction to the concepts of phonons and conservation laws, the effects of photon-phonon interactions are presented. This interaction concept is shown for a simple cubic crystal and is extended to a uniaxial crystal. The correlation table method is used for determining the number and symmetry of the Raman active modes. Finally, examples are given to illustrate the relative ease of using this group theoretical method and the predictions are compared with measured Raman spectra. 37 refs., 17 figs., 6 tabs.

  14. Silumins alloy crystallization

    Directory of Open Access Journals (Sweden)

    S. Pietrowski

    2009-07-01

    Full Text Available This paper presents the results of research, by ATD method, of hypo-, near- and hyperutectic silumins crystallization containing the following alloying additives: Mg, Ni, Cu, Cr, Mo, W, V. It has been shown that, depending on their concentration may crystallize pre-eutectic or eutectic multicomponent phases containing these alloy additives. It has been revealed that any subsequent crystallizable phase nucleate and grows near the liquid/former crystallized phase interface. In multiphases compound also falls the silicon, resulting in a reduction in its quantity and the fragmentation in the eutectic mixture. As a result, it gets a high hardness of silumins in terms of 110-220HB.

  15. Formamidinium iodide: crystal structure and phase transitions

    Directory of Open Access Journals (Sweden)

    Andrey A. Petrov

    2017-04-01

    Full Text Available At a temperature of 100 K, CH5N2+·I− (I, crystallizes in the monoclinic space group P21/c. The formamidinium cation adopts a planar symmetrical structure [the r.m.s. deviation is 0.002 Å, and the C—N bond lengths are 1.301 (7 and 1.309 (8 Å]. The iodide anion does not lie within the cation plane, but deviates from it by 0.643 (10 Å. The cation and anion of I form a tight ionic pair by a strong N—H...I hydrogen bond. In the crystal of I, the tight ionic pairs form hydrogen-bonded zigzag-like chains propagating toward [20-1] via strong N—H...I hydrogen bonds. The hydrogen-bonded chains are further packed in stacks along [100]. The thermal behaviour of I was studied by different physicochemical methods (thermogravimetry, differential scanning calorimetry and powder diffraction. Differential scanning calorimetry revealed three narrow endothermic peaks at 346, 387 and 525 K, and one broad endothermic peak at ∼605 K. The first and second peaks are related to solid–solid phase transitions, while the third and fourth peaks are attributed to the melting and decomposition of I. The enthalpies of the phase transitions at 346 and 387 K are estimated as 2.60 and 2.75 kJ mol−1, respectively. The X-ray powder diffraction data collected at different temperatures indicate the existence of I as the monoclinic (100–346 K, orthorhombic (346–387 K and cubic (387–525 K polymorphic modifications.

  16. Analysis of Peak-to-Peak Current Ripple Amplitude in Seven-Phase PWM Voltage Source Inverters

    Directory of Open Access Journals (Sweden)

    Gabriele Grandi

    2013-08-01

    Full Text Available Multiphase systems are nowadays considered for various industrial applications. Numerous pulse width modulation (PWM schemes for multiphase voltage source inverters with sinusoidal outputs have been developed, but no detailed analysis of the impact of these modulation schemes on the output peak-to-peak current ripple amplitude has been reported. Determination of current ripple in multiphase PWM voltage source inverters is important for both design and control purposes. This paper gives the complete analysis of the peak-to-peak current ripple distribution over a fundamental period for multiphase inverters, with particular reference to seven-phase VSIs. In particular, peak-to-peak current ripple amplitude is analytically determined as a function of the modulation index, and a simplified expression to get its maximum value is carried out. Although reference is made to the centered symmetrical PWM, being the most simple and effective solution to maximize the DC bus utilization, leading to a nearly-optimal modulation to minimize the RMS of the current ripple, the analysis can be readily extended to either discontinuous or asymmetrical modulations, both carrier-based and space vector PWM. A similar approach can be usefully applied to any phase number. The analytical developments for all different sub-cases are verified by numerical simulations.

  17. Automatic program for peak detection and deconvolution of multi-overlapped chromatographic signals part I: peak detection.

    Science.gov (United States)

    Vivó-Truyols, G; Torres-Lapasió, J R; van Nederkassel, A M; Vander Heyden, Y; Massart, D L

    2005-11-25

    A series of two papers describing a procedure for automated peak deconvolution is presented. The goal is to develop a package of routines that can be used by non-experienced users. Part I (this paper) concerns peak detection, whereas Part II is dedicated to the deconvolution itself. In this first part, the most interesting features of the peak detection algorithms, which precede the deconvolution step, are outlined. High-order derivatives provide valuable information to assess the number of underlying compounds under a given peak cluster. A smoothing technique was found essential to compute properly the derivatives, since the noise is amplified when differences are calculated. The Savitsky-Golay smoother was applied in combination with the Durbin-Watson criterion to automate the window size selection. This strategy removed the noise without loosing valuable information. In some cases, it was found preferable to split the chromatogram in different elution regions, and apply the Durbin-Watson test and the Savitsky-Golay smoother to each region, separately. The derivatives allowed obtaining estimates of both peak parameters and the corresponding ranges for each eluting compound to be used in the deconvolution. An algorithm oriented to compare peaks from different chromatograms is also presented to perform deconvolution, using information from several related chromatograms.

  18. Crystal Field Handbook

    Science.gov (United States)

    Newman, D. J.; Ng, Betty

    2007-09-01

    List of contributors; Preface; Introduction; 1. Crystal field splitting mechanisms D. J. Newman and Betty Ng; 2. Empirical crystal fields D. J. Newman and Betty Ng; 3. Fitting crystal field parameters D. J. Newman and Betty Ng; 4. Lanthanide and actinide optical spectra G. K. Liu; 5. Superposition model D. J. Newman and Betty Ng; 6. Effects of electron correlation on crystal field splitting M. F. Reid and D. J. Newman; 7. Ground state splittings in S-state ions D. J. Newman and Betty Ng; 8. Invariants and moments Y. Y. Yeung; 9. Semiclassical model K. S. Chan; 10. Transition intensities M. F. Reid; Appendix 1. Point symmetry D. J. Newman and Betty Ng; Appendix 2. QBASIC programs D. J. Newman and Betty Ng; Appendix 3. Accessible program packages Y. Y. Yeung, M. F. Reid and D. J. Newman; Appendix 4. Computer package CST Cz. Rudowicz; Bibliography; Index.

  19. Hybrid photonic crystal fiber

    National Research Council Canada - National Science Library

    Arismar Cerqueira S. Jr; F. Luan; C. M. B. Cordeiro; A. K. George; J. C. Knight

    2006-01-01

    We present a hybrid photonic crystal fiber in which a guided mode is confined simultaneously by modified total internal reflection from an array of air holes and antiresonant reflection from a line...

  20. Crystal-Clear Technology.

    Science.gov (United States)

    Ondris-Crawford, Renate J.; And Others

    1993-01-01

    Provides diagrams to aid in discussing polymer dispersed liquid crystal (PDLC) technology. Equipped with a knowledge of PDLC, teachers can provide students with insight on how the gap between basic science and technology is bridged. (ZWH)

  1. Group Elevator Peak Scheduling Based on Robust Optimization Model

    Directory of Open Access Journals (Sweden)

    ZHANG, J.

    2013-08-01

    Full Text Available Scheduling of Elevator Group Control System (EGCS is a typical combinatorial optimization problem. Uncertain group scheduling under peak traffic flows has become a research focus and difficulty recently. RO (Robust Optimization method is a novel and effective way to deal with uncertain scheduling problem. In this paper, a peak scheduling method based on RO model for multi-elevator system is proposed. The method is immune to the uncertainty of peak traffic flows, optimal scheduling is realized without getting exact numbers of each calling floor's waiting passengers. Specifically, energy-saving oriented multi-objective scheduling price is proposed, RO uncertain peak scheduling model is built to minimize the price. Because RO uncertain model could not be solved directly, RO uncertain model is transformed to RO certain model by elevator scheduling robust counterparts. Because solution space of elevator scheduling is enormous, to solve RO certain model in short time, ant colony solving algorithm for elevator scheduling is proposed. Based on the algorithm, optimal scheduling solutions are found quickly, and group elevators are scheduled according to the solutions. Simulation results show the method could improve scheduling performances effectively in peak pattern. Group elevators' efficient operation is realized by the RO scheduling method.

  2. What predicts the first peak of the knee adduction moment?

    Science.gov (United States)

    Schmitz, Anne; Noehren, Brian

    2014-01-01

    Introduction The first peak of the knee adduction moment curve during walking has been shown to be a good clinical surrogate measure of medial tibiofemoral joint loading and osteoarthritis. Defining the relative contributions of the variables that dictate the knee adduction moment, such as center of mass, center of pressure, vertical ground reaction force, and knee adduction angle (i.e. lower limb alignment), has not been formally investigated within the same cohort of individuals. Purpose Therefore, the goal of this study was to determine which of these variables is the biggest determinant of the first peak of knee adduction moment curve. Methods Instrumented gait analysis was collected for 30 individuals. Variables significantly correlated with the peak knee adduction moment were input into a stepwise multi-variable linear regression model. Results The knee adduction angle predicted 58% of the variance in the first peak knee adduction moment and the vertical ground reaction force magnitude predicted the second most variance (20%). Conclusions The most effective way to modify the peak knee adduction moment may be to change the knee adduction angle (e.g. offloader brace), followed by changing the vertical magnitude of the ground reaction force (e.g. cane use). PMID:25127390

  3. Rotational and peak torque stiffness of rugby shoes.

    Science.gov (United States)

    Ballal, Moez S; Usuelli, Federico Giuseppe; Montrasio, Umberto Alfieri; Molloy, Andy; La Barbera, Luigi; Villa, Tomaso; Banfi, Giuseppe

    2014-09-01

    Sports people always strive to avoid injury. Sports shoe designs in many sports have been shown to affect traction and injury rates. The aim of this study is to demonstrate the differing stiffness and torque in rugby boots that are designed for the same effect. Five different types of rugby shoes commonly worn by scrum forwards were laboratory tested for rotational stiffness and peak torque on a natural playing surface generating force patterns that would be consistent with a rugby scrum. The overall internal rotation peak torque was 57.75±6.26 Nm while that of external rotation was 56.55±4.36 Nm. The Peak internal and external rotational stiffness were 0.696±0.1 and 0.708±0.06 Nm/deg respectively. Our results, when compared to rotational stiffness and peak torques of football shoes published in the literature, show that shoes worn by rugby players exert higher rotational and peak torque stiffness compared to football shoes when tested on the same natural surfaces. There was significant difference between the tested rugby shoes brands. In our opinion, to maximize potential performance and lower the potential of non-contact injury, care should be taken in choosing boots with stiffness appropriate to the players main playing role. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Energy Saving by Chopping off Peak Demand Using Day Light

    Directory of Open Access Journals (Sweden)

    Ashok Kumar Maitra

    2011-08-01

    Full Text Available An artificial intelligent technique has been implemented in this research using real time datas to calculate how much energy can be chopped from peak load demand. The results are based on real time data that are taken from power delivering centers. These datas do reflect the present condition of power and a solution to those critical conditions during the peak period. These are done in such a way such that helps in judicious scheduling of load. The time based load scheduling has been done so as to understand the basic criteria for solving power crisis during morning peak and early evening peak. The sunray availability and percentage of load that will use day light saving (DLS technique has been taken into account in this work. The results shows that about 0.5% to 1% of load can be shedded off from the peak load period which otherwise is reduction of power. Thus it otherwise also means that an equivalent amount of energy is saved which amounts to a large saving of national money. This result is obtained on monthly and even daily basis. Thus this paper justifies DLS gives a new renewable technique to save energy.

  5. Accuracy of portable devices in measuring peak cough flow.

    Science.gov (United States)

    Kulnik, Stefan Tino; MacBean, Victoria; Birring, Surinder Singh; Moxham, John; Rafferty, Gerrard Francis; Kalra, Lalit

    2015-02-01

    Peak cough flow (PCF) measurements can be used as indicators of cough effectiveness. Portable peak flow meters and spirometers have been used to measure PCF, but little is known about their accuracy compared to pneumotachograph systems. The aim of this study was to compare the accuracy of four portable devices (Mini-Wright and Assess peak flow meters, SpiroUSB and Microlab spirometers) in measuring PCF with a calibrated laboratory based pneumotachograph system. Twenty healthy volunteers (mean (SD) age 45 (16) years) coughed through a pneumotachograph connected in series with each portable device in turn, and the differences in PCF readings were analysed. In addition, mechanically generated flow waves of constant peak flow were delivered through each device both independently and when connected in series with the pneumotachograph. Agreement between PCF readings obtained with the pneumotachograph and the portable devices was poor. Peak flow readings were on average lower by approximately 50 L min(-1) when measured using the portable devices; 95% limits of agreement spanned approximately 150 L min(-1). The findings highlight the potential for inaccuracy when using portable devices for the measurement of PCF. Depending on the measurement instrument used, absolute values of PCF reported in the literature may not be directly comparable.

  6. Pediatric Exercise Testing: Value and Implications of Peak Oxygen Uptake

    Directory of Open Access Journals (Sweden)

    Paolo T. Pianosi

    2017-01-01

    Full Text Available Peak oxygen uptake (peak V ˙ O 2 measured by clinical exercise testing is the benchmark for aerobic fitness. Aerobic fitness, estimated from maximal treadmill exercise, is a predictor of mortality in adults. Peak V ˙ O 2 was shown to predict longevity in patients aged 7–35 years with cystic fibrosis over 25 years ago. A surge of exercise studies in young adults with congenital heart disease over the past decade has revealed significant prognostic information. Three years ago, the first clinical trial in children with pulmonary arterial hypertension used peak V ˙ O 2 as an endpoint that likewise delivered clinically relevant data. Cardiopulmonary exercise testing provides clinicians with biomarkers and clinical outcomes, and researchers with novel insights into fundamental biological mechanisms reflecting an integrated physiological response hidden at rest. Momentum from these pioneering observations in multiple disease states should impel clinicians to employ similar methods in other patient populations; e.g., sickle cell disease. Advances in pediatric exercise science will elucidate new pathways that may identify novel biomarkers. Our initial aim of this essay is to highlight the clinical relevance of exercise testing to determine peak V ˙ O 2 , and thereby convince clinicians of its merit, stimulating future clinical investigators to broaden the application of exercise testing in pediatrics.

  7. Non-Gaussian bias: insights from discrete density peaks

    CERN Document Server

    Desjacques, Vincent; Riotto, Antonio

    2013-01-01

    Corrections induced by primordial non-Gaussianity to the linear halo bias can be computed from a peak-background split or the widespread local bias model. However, numerical simulations clearly support the prediction of the former, in which the non-Gaussian amplitude is proportional to the linear halo bias. To understand better the reasons behind the failure of standard Lagrangian local bias, in which the halo overdensity is a function of the local mass overdensity only, we explore the effect of a primordial bispectrum on the 2-point correlation of discrete density peaks. We show that the effective local bias expansion to peak clustering vastly simplifies the calculation. We generalize this approach to excursion set peaks and demonstrate that the resulting non-Gaussian amplitude, which is a weighted sum of quadratic bias factors, precisely agrees with the peak-background split expectation, which is a logarithmic derivative of the halo mass function with respect to the normalisation amplitude. We point out tha...

  8. An online peak extraction algorithm for ion mobility spectrometry data.

    Science.gov (United States)

    Kopczynski, Dominik; Rahmann, Sven

    2015-01-01

    Ion mobility (IM) spectrometry (IMS), coupled with multi-capillary columns (MCCs), has been gaining importance for biotechnological and medical applications because of its ability to detect and quantify volatile organic compounds (VOC) at low concentrations in the air or in exhaled breath at ambient pressure and temperature. Ongoing miniaturization of spectrometers creates the need for reliable data analysis on-the-fly in small embedded low-power devices. We present the first fully automated online peak extraction method for MCC/IMS measurements consisting of several thousand individual spectra. Each individual spectrum is processed as it arrives, removing the need to store the measurement before starting the analysis, as is currently the state of the art. Thus the analysis device can be an inexpensive low-power system such as the Raspberry Pi. The key idea is to extract one-dimensional peak models (with four parameters) from each spectrum and then merge these into peak chains and finally two-dimensional peak models. We describe the different algorithmic steps in detail and evaluate the online method against state-of-the-art peak extraction methods.

  9. Households' hourly electricity consumption and peak demand in Denmark

    DEFF Research Database (Denmark)

    Møller Andersen, Frits; Baldini, Mattia; Hansen, Lars Gårn

    2017-01-01

    The electrification of residential energy demand for heating and transportation is expected to increase peak load and require additional generation and transmission capacities. Electrification also provides an opportunity to increase demand response. With a focus on household electricity consumpt......The electrification of residential energy demand for heating and transportation is expected to increase peak load and require additional generation and transmission capacities. Electrification also provides an opportunity to increase demand response. With a focus on household electricity...... consumption, we analyse the contribution of appliances and new services, such as individual heat pumps and electric vehicles, to peak consumption and the need for demand response incentives to reduce the peak.Initially, the paper presents a new model that represents the hourly electricity consumption profile...... to a considerable introduction of electric vehicles and individual heat pumps, household consumption is expected to increase considerably, especially peak hour consumption is expected to increase.Next the paper presents results from a new experiment where household customers are given economic and/or environmental...

  10. Liquid Crystal Airborne Display

    Science.gov (United States)

    1977-08-01

    with the drive capability of the present state-of-the- art microm.ziiaturized integi ated circuits. The impact of microminiaturizing the drive circuits...7 Advantages /Disadvantages of Prior Art .........- 8 Performance of the Liquid Crystal Matrix Display . . .. 8 Liquid Crystal...Holographic HUD Light Source ...................... .... 99 Design of a Special Purpose Mercury Art - Plo.?hcr La np . 104 V LARGE SCALE INTEGRATION FOR DISPLAY

  11. Active cluster crystals

    Science.gov (United States)

    Delfau, Jean-Baptiste; López, Cristóbal; Hernández-García, Emilio

    2017-09-01

    We study the appearance and properties of cluster crystals (solids in which the unit cell is occupied by a cluster of particles) in a two-dimensional system of self-propelled active Brownian particles with repulsive interactions. Self-propulsion deforms the clusters by depleting particle density inside, and for large speeds it melts the crystal. Continuous field descriptions at several levels of approximation allow us to identify the relevant physical mechanisms.

  12. SINGLE CRYSTAL NEUTRON DIFFRACTION.

    Energy Technology Data Exchange (ETDEWEB)

    KOETZLE,T.F.

    2001-03-13

    Single-crystal neutron diffraction measures the elastic Bragg reflection intensities from crystals of a material, the structure of which is the subject of investigation. A single crystal is placed in a beam of neutrons produced at a nuclear reactor or at a proton accelerator-based spallation source. Single-crystal diffraction measurements are commonly made at thermal neutron beam energies, which correspond to neutron wavelengths in the neighborhood of 1 Angstrom. For high-resolution studies requiring shorter wavelengths (ca. 0.3-0.8 Angstroms), a pulsed spallation source or a high-temperature moderator (a ''hot source'') at a reactor may be used. When complex structures with large unit-cell repeats are under investigation, as is the case in structural biology, a cryogenic-temperature moderator (a ''cold source'') may be employed to obtain longer neutron wavelengths (ca. 4-10 Angstroms). A single-crystal neutron diffraction analysis will determine the crystal structure of the material, typically including its unit cell and space group, the positions of the atomic nuclei and their mean-square displacements, and relevant site occupancies. Because the neutron possesses a magnetic moment, the magnetic structure of the material can be determined as well, from the magnetic contribution to the Bragg intensities. This latter aspect falls beyond the scope of the present unit; for information on magnetic scattering of neutrons see Unit 14.3. Instruments for single-crystal diffraction (single-crystal diffractometers or SCDs) are generally available at the major neutron scattering center facilities. Beam time on many of these instruments is available through a proposal mechanism. A listing of neutron SCD instruments and their corresponding facility contacts is included in an appendix accompanying this unit.

  13. PHOTONIC CRYSTAL WAVEGUIDE BIOSENSOR

    Directory of Open Access Journals (Sweden)

    A. A. ZANISHEVSKAYA

    2013-04-01

    Full Text Available The hollow core photonic crystal waveguide biosensor is designed and described. The biosensor was tested in experiments for artificial sweetener identification in drinks. The photonic crystal waveguide biosensor has a high sensitivity to the optical properties of liquids filling up the hollow core. The compactness, good integration ability to different optical systems and compatibility for use in industrial settings make such biosensor very promising for various biomedical applications.

  14. Crystal growth of drug materials by spherical crystallization

    Science.gov (United States)

    Szabó-Révész, P.; Hasznos-Nezdei, M.; Farkas, B.; Göcző, H.; Pintye-Hódi, K.; Erős, I.

    2002-04-01

    One of the crystal growth processes is the production of crystal agglomerates by spherical crystallization. Agglomerates of drug materials were developed by means of non-typical (magnesium aspartate) and typical (acetylsalicylic acid) spherical crystallization techniques. The growth of particle size and the spherical form of the agglomerates resulted in formation of products with good bulk density, flow, compactibility and cohesivity properties. The crystal agglomerates were developed for direct capsule-filling and tablet-making.

  15. Nanoscale simultaneous chemical and mechanical imaging via peak force infrared microscopy

    Science.gov (United States)

    Wang, Le; Wang, Haomin; Wagner, Martin; Yan, Yong; Jakob, Devon S.; Xu, Xiaoji G.

    2017-01-01

    Nondestructive chemical and mechanical measurements of materials with ~10-nm spatial resolution together with topography provide rich information on the compositions and organizations of heterogeneous materials and nanoscale objects. However, multimodal nanoscale correlations are difficult to achieve because of the limitation on spatial resolution of optical microscopy and constraints from instrumental complexities. We report a novel noninvasive spectroscopic scanning probe microscopy method—peak force infrared (PFIR) microscopy—that allows chemical imaging, collection of broadband infrared spectra, and mechanical mapping at a spatial resolution of 10 nm. In our technique, chemical absorption information is directly encoded in the withdraw curve of the peak force tapping cycle after illumination with synchronized infrared laser pulses in a simple apparatus. Nanoscale phase separation in block copolymers and inhomogeneity in CH3NH3PbBr3 perovskite crystals are studied with correlative infrared/mechanical nanoimaging. Furthermore, we show that the PFIR method is sensitive to the presence of surface phonon polaritons in boron nitride nanotubes. PFIR microscopy will provide a powerful analytical tool for explorations at the nanoscale across wide disciplines. PMID:28691096

  16. Building a crystal palace

    CERN Multimedia

    2007-01-01

    The end-caps of the CMS electromagnetic calorimeter (ECAL) take shape as the first quadrant was completed on Wednesday 3 October. 1831 crystals, organised into five by five blocks named ‘supercrystals’, make up the first quadrant of Dee 1.With the 61,200-crystal barrel of its electromagnetic calorimeter (ECAL) complete, CMS is now building the endcaps, on the tenth anniversary of their initial design. Crystals for the endcaps were the last to be made, so the race is now on to have them all in place and ready for the turn-on of the LHC next year. Assembly of the first of eight quadrants began in June and crystal mounting was completed on Wednesday 3 October. Each crystal is transparent, has a volume just larger than a CERN coffee cup yet weighs a huge 1.5kg. 1831 of these lead tungstate crystals went into the first quadrant from a total 14,648 in the endcaps. The lead and tungsten account for 86% of each crystal’s weight, but as project leader Dave Cockerill expl...

  17. Effects of sample size on the second magnetization peak in ...

    Indian Academy of Sciences (India)

    8+ crystals are observed at low temperatures, above the temperature where the SMP totally disappears. In particular, the onset of the SMP shifts to lower fields as the sample size decreases - a result that could be interpreted as a size effect in ...

  18. Size-independent peak shift between normal and upconversion ...

    Indian Academy of Sciences (India)

    2014-02-12

    Feb 12, 2014 ... Author Affiliations. S Ananthakumar1 J Jayabalan2 Asha Singh2 Salahuddin Khan2 Subhash Prajapati2 S Moorthy Babu1 Rama Chari2. Crystal Growth Centre, Anna University, Chennai 600 025, India; Laser Physics Applications Section, Raja Ramanna Centre for Advanced Technology, Indore 452 013, ...

  19. High-throughput crystallization screening.

    Science.gov (United States)

    Skarina, Tatiana; Xu, Xiaohui; Evdokimova, Elena; Savchenko, Alexei

    2014-01-01

    Protein structure determination by X-ray crystallography is dependent on obtaining a single protein crystal suitable for diffraction data collection. Due to this requirement, protein crystallization represents a key step in protein structure determination. The conditions for protein crystallization have to be determined empirically for each protein, making this step also a bottleneck in the structure determination process. Typical protein crystallization practice involves parallel setup and monitoring of a considerable number of individual protein crystallization experiments (also called crystallization trials). In these trials the aliquots of purified protein are mixed with a range of solutions composed of a precipitating agent, buffer, and sometimes an additive that have been previously successful in prompting protein crystallization. The individual chemical conditions in which a particular protein shows signs of crystallization are used as a starting point for further crystallization experiments. The goal is optimizing the formation of individual protein crystals of sufficient size and quality to make them suitable for diffraction data collection. Thus the composition of the primary crystallization screen is critical for successful crystallization.Systematic analysis of crystallization experiments carried out on several hundred proteins as part of large-scale structural genomics efforts allowed the optimization of the protein crystallization protocol and identification of a minimal set of 96 crystallization solutions (the "TRAP" screen) that, in our experience, led to crystallization of the maximum number of proteins.

  20. The spectrum of the Kitt Peak night sky

    Science.gov (United States)

    Massey, Philip; Gronwall, Caryl; Pilachowski, Catherine A.

    1990-08-01

    Absolute spectrophotometry of the Kitt Peak night sky at a variety of azimuths an zenith angles is presented, and the effect of population increase in Pima County on the dark-sky properties of Kitt Peak National Observatory in Arizona is studied. The results confirm that Kitt Peak remains a dark site, even after significant recent population growth of the surrounding area. The major line contributor to the B band is Hg, while the dominant source of contamination to the V-band measures are atmospheric lines, most notably O I 5577 A. Using fluxed observations of street lamps it was found that the relative contribution to light pollution in the yellow-red (5000 A - 6500 A) is 10 percent Hg, 30 percent LPS, and 60 percent HPS. No significant azimuthal effects are seen; it is noted that the sky remains equally dark toward Phoenix and Tucson as it does in other directions for zenith distances of 60 deg or less.

  1. A Multimethod analysis of the Phenomenon of Peak-Oil

    OpenAIRE

    Kerschner, Christian

    2012-01-01

    El concepto de Peak-Oil (el cénit del petróleo) es complejo y a menudo malentendido. Después de aclarar que el Peak-Oil es tanto un problema de estocs como de flujos, se ofrecen los conceptos de calidad y cantidad del recurso para facilitar la comprensión de la multitud de temas que influyen en el momento del cénit del petróleo y sus posibles impactos. Una revisión de la literatura y las últimas evidencias sugieren que hay un alto riesgo de que el Peak-Oil ocurra antes de 2020, dejando poco t...

  2. [Radiobiological effects of total mice irradiation with Bragg's peak protons].

    Science.gov (United States)

    Ivanov, A A; Molokanov, A G; Ushakov, I B; Bulynina, T M; Vorozhtsova, S V; Abrosimova, A N; Kryuchkova, D M; Gaevsky, V N

    2013-01-01

    Outbred CD-1 female mice were irradiated in a proton beam (171 MeV, 5 Gy) on the phasotron at the Joint Institute of Nuclear Research (Dubna, Russia). Radiation was delivered in two points of the depth dose distribution: at the beam entry and on Bragg's peak. Technical requirements for studying the effects of Bragg's peak protons on organism of experimental animals were specified. It was recognized that protons with high linear energy transfer (mean LET = 1.6 keV/microm) cause a more severe damaging effect to the hemopoietic system and cytogenetic apparatus in bone marrow cells as compared with entry protons and 60Co gamma-quanta. It was shown that recovery of the main hemopoietic organs and immunity as well as elimination of chromosomal aberrations take more time following irradiation with Bragg's peak protons but not protons with the energy of 171 MeV.

  3. Correlation Filter Learning Toward Peak Strength for Visual Tracking.

    Science.gov (United States)

    Sui, Yao; Wang, Guanghui; Zhang, Li

    2017-04-13

    This paper presents a novel visual tracking approach to correlation filter learning toward peak strength of correlation response. Previous methods leverage all features of the target and the immediate background to learn a correlation filter. Some features, however, may be distractive to tracking, like those from occlusion and local deformation, resulting in unstable tracking performance. This paper aims at solving this issue and proposes a novel algorithm to learn the correlation filter. The proposed approach, by imposing an elastic net constraint on the filter, can adaptively eliminate those distractive features in the correlation filtering. A new peak strength metric is proposed to measure the discriminative capability of the learned correlation filter. It is demonstrated that the proposed approach effectively strengthens the peak of the correlation response, leading to more discriminative performance than previous methods. Extensive experiments on a challenging visual tracking benchmark demonstrate that the proposed tracker outperforms most state-of-the-art methods.

  4. The effects of increasing heel height on forefoot peak pressure.

    Science.gov (United States)

    Mandato, M G; Nester, E

    1999-02-01

    The purpose of this study was to determine the effect of increasing heel height on peak forefoot pressure. Thirty-five women were examined while wearing sneakers and shoes with 2-inch and 3-inch heels. An in-shoe pressure-measurement system was used to document the magnitude and location of plantar peak pressures. Pressure under the forefoot was found to increase significantly with increasing heel height. As the heel height increased, the peak pressure shifted toward the first metatarsal and the hallux. The reproducibility of data obtained with the in-shoe pressure-measurement system was tested in five subjects; the data were found to be reproducible to within approximately 3% of measured pressures.

  5. Gnevyshev peaks in solar radio emissions at different frequencies

    Directory of Open Access Journals (Sweden)

    R. P. Kane

    2009-04-01

    Full Text Available Sunspots have a major 11-year cycle, but the years near the sunspot maximum show two or more peaks called GP (Gnevyshev Peaks. In this communication, it was examined whether these peaks in sunspots are reflected in other parameters such as Lyman-α (the chromospheric emission 121.6 nm, radio emissions 242–15 400 MHz emanating from altitude levels 2000–12 000 km, the low latitude (+45° to −45° solar open magnetic flux and the coronal green line emission (Fe XIV, 530.3 nm. In the different solar cycles 20–23, the similarity extended at least upto the level of 609 MHz, but in cycle 22, the highest level was of 242 MHz. The extension to the higher level in cycle 22 does not seem to be related to the cycle strength Rz(max, or to the cycle length.

  6. COPAR: A ChIP-Seq Optimal Peak Analyzer.

    Science.gov (United States)

    Tang, Binhua; Wang, Xihan; Jin, Victor X

    2017-01-01

    Sequencing data quality and peak alignment efficiency of ChIP-sequencing profiles are directly related to the reliability and reproducibility of NGS experiments. Till now, there is no tool specifically designed for optimal peak alignment estimation and quality-related genomic feature extraction for ChIP-sequencing profiles. We developed open-sourced COPAR, a user-friendly package, to statistically investigate, quantify, and visualize the optimal peak alignment and inherent genomic features using ChIP-seq data from NGS experiments. It provides a versatile perspective for biologists to perform quality-check for high-throughput experiments and optimize their experiment design. The package COPAR can process mapped ChIP-seq read file in BED format and output statistically sound results for multiple high-throughput experiments. Together with three public ChIP-seq data sets verified with the developed package, we have deposited COPAR on GitHub under a GNU GPL license.

  7. r-process abundances near the mass 130 peak

    Energy Technology Data Exchange (ETDEWEB)

    De Laeter, J.R.; Rosman, K.J.R.

    1983-07-15

    A recent article by Kaeppeler et al. has reevaluated r-process abundances in the light of new neutron-capture cross section and elemental abundance data. The height of the r-process peak near mass 130 is largely determined by the r-only process nuclides /sup 128/Te and /sup 130/Te. Recent work by Smith, De Laeter and Rosman has not been given due consideration is assessing the solar system abundance of tellurium. These data indicate a 25% reduction in the height of the mass 130 peak, in agreement with predictions from s-process systematics.

  8. Peak Oil and the Everyday Complexity of Human Progress Narratives

    Directory of Open Access Journals (Sweden)

    John C. Pruit

    2012-11-01

    Full Text Available The “big” story of human progress has polarizing tendencies featuring the binary options of progress or decline. I consider human progress narratives in the context of everyday life. Analysis of the “little” stories from two narrative environments focusing on peak oil offers a more complex picture of the meaning and contours of the narrative. I consider the impact of differential blog site commitments to peak oil perspectives and identify five narrative types culled from two narrative dimensions. I argue that the lived experience complicates human progress narratives, which is no longer an either/or proposition.

  9. Peak heart rate decreases with increasing severity of acute hypoxia

    DEFF Research Database (Denmark)

    Lundby, C; Araoz, M; Van Hall, Gerrit

    2001-01-01

    The purpose of the present study was to investigate the degree to which peak heart rate is reduced during exhaustive exercise in acute hypoxia. Five sea-level lowlanders performed maximal exercise at normobaric normoxia and at three different levels of hypobaric hypoxia (barometric pressures of 518......, 459, and 404 mmHg) in a hypobaric chamber and while breathing 9% O(2) in N(2). These conditions were equivalent to altitudes of 3300, 4300, 5300, and 6300 m above sea level, respectively. At 4300 m, maximal exercise was also repeated after 4 and 8 h. Peak heart rate (HR) decreased from 191 (182...

  10. National energy peak leveling program (NEPLP). Final report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-12-01

    This three-volume report is responsive to the requirements of contract E (04-3)-1152 to provide a detailed methodology, to include management, technology, and socio-economic aspects, of a voluntary community program for computer-assisted peak load leveling and energy conservation in commercial community facilities. The demonstration project established proof-of-concept in reducing the kW-demand peak by the unofficial goal of 10%, with concurrent kWh savings. The report consists of the following three volumes: Volume I: management overview; Volume II: methodology and technology; and Volume III; appendices.

  11. Quasispecies evolution on a fitness landscape with a fluctuating peak

    OpenAIRE

    Nilsson, Martin; Snoad, Nigel

    2000-01-01

    A quasispecies evolving on a fitness landscape with a single peak of fluctuating height is studied. In the approximation that back mutations can be ignored, the rate equations can be solved analytically. It is shown that the error threshold on this class of dynamic landscapes is defined by the time average of the selection pressure. In the case of a periodically fluctuating fitness peak we also study the phase-shift and response amplitude of the previously documented low-pass filter effect. T...

  12. Spectral analysis of crater central peak material (ccp)

    Science.gov (United States)

    Galiano, A.; Palomba, E.; Longobardo, A.; De Sanctis, M. C.; Carrozzo, F. G.; Tosi, F.

    2017-09-01

    The dwarf planet Ceres, the largest and most massive object in the main asteroid belt, is dark and heavily cratered by impacts. The detection of bright spots, especially in the Occator crater, suggested a vertical gradient in Ceres mineralogical composition. Geologic mapping of Ceres enabled the identification of various surface features of interest. Here we focus our attention on the geologic units known as crater central peak material (ccp). Ccp composes the central peak of several complex craters, probably representative of fresher material coming from the subsurface as a consequence of the impact. We carried out a spectral analysis of ccps found on Ceres to investigate the mineralogical properties of the subsurface material.

  13. Peak metamorphic temperatures from cation diffusion zoning in garnet

    DEFF Research Database (Denmark)

    Smit, Matthijs Arjen; Scherer, Erik; Mezger, Klaus

    2013-01-01

    A model that relates the characteristic diffusion length and average cooling rate to peak temperature was developed for chemical diffusion in spherical geometries on the basis of geospeedometry principles and diffusion theory. The model is quantitatively evaluated for cation diffusion profiles...... peak temperature estimates. The results overlap within uncertainties in all cases, but result that are based on Fe(II) and Mg chemical-diffusion profiles are up to three times more precise than those acquired by conventional methods. The remarkable consistency of the results implies that the model...

  14. Peptide mass fingerprinting peak intensity prediction: extracting knowledge from spectra.

    Science.gov (United States)

    Gay, Steven; Binz, Pierre-Alain; Hochstrasser, Denis F; Appel, Ron D

    2002-10-01

    Matrix-assisted laser desorption/ionization-time of flight mass spectrometry has become a valuable tool in proteomics. With the increasing acquisition rate of mass spectrometers, one of the major issues is the development of accurate, efficient and automatic peptide mass fingerprinting (PMF) identification tools. Current tools are mostly based on counting the number of experimental peptide masses matching with theoretical masses. Almost all of them use additional criteria such as isoelectric point, molecular weight, PTMs, taxonomy or enzymatic cleavage rules to enhance prediction performance. However, these identification tools seldom use peak intensities as parameter as there is currently no model predicting the intensities based on the physicochemical properties of peptides. In this work, we used standard datamining methods such as classification and regression methods to find correlations between peak intensities and the properties of the peptides composing a PMF spectrum. These methods were applied on a dataset comprising a series of PMF experiments involving 157 proteins. We found that the C4.5 method gave the more informative results for the classification task (prediction of the presence or absence of a peptide in a spectra) and M5' for the regression methods (prediction of the normalized intensity of a peptide peak). The C4.5 result correctly classified 88% of the theoretical peaks; whereas the M5' peak intensities had a correlation coefficient of 0.6743 with the experimental peak intensities. These methods enabled us to obtain decision and model trees that can be directly used for prediction and identification of PMF results. The work performed permitted to lay the foundations of a method to analyze factors influencing the peak intensity of PMF spectra. A simple extension of this analysis could lead to improve the accuracy of the results by using a larger dataset. Additional peptide characteristics or even PMF experimental parameters can also be taken into

  15. National energy peak leveling program (NEPLP). Final report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-12-01

    This multisectioned three-Volume report is responsive to the requirements of Contract E (04-3)-1152 to provide a detailed methodology, to include management, technology, and socio-economic aspects, of a voluntary community program of computer-assisted peak load leveling and energy conservation in commercial community facilities. The demonstration project established proof-of-concept in reducing the kW-demand peak by the unofficial goal of 10%, with concurrent kWh savings. This section of volume III contains appendixes of information on load shedding determination, analysis, socio-economic study, contractual cross references, and definitions.

  16. Identification and separation of DNA mixtures using peak area information

    DEFF Research Database (Denmark)

    Cowell, R.G.; Lauritzen, Steffen Lilholt; Mortera, J.

    We show how probabilistic expert systems can be used to analyse forensic identification problems involving DNA mixture traces using quantitative peak area information. Peak area is modelled with conditional Gaussian distributions. The expert system can be used for scertaining whether individuals......, whose profiles have been measured, have contributed to the mixture, but also to predict DNA profiles of unknown contributors by separating the mixture into its individual components. The potential of our methodology is illustrated on case data examples and compared with alternative approaces...

  17. High-Average, High-Peak Current Injector Design

    CERN Document Server

    Biedron, S G; Virgo, M

    2005-01-01

    There is increasing interest in high-average-power (>100 kW), um-range FELs. These machines require high peak current (~1 kA), modest transverse emittance, and beam energies of ~100 MeV. High average currents (~1 A) place additional constraints on the design of the injector. We present a design for an injector intended to produce the required peak currents at the injector, eliminating the need for magnetic compression within the linac. This reduces the potential for beam quality degradation due to CSR and space charge effects within magnetic chicanes.

  18. National energy peak leveling program (NEPLP). Final report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-12-01

    This three-volume report is responsive to the requirements of Contract E (04-3)-1152 to provide a detailed methodology, to include management, technology, and socio-economic aspects, of a voluntary community program of computer-assisted peak load leveling and energy conservation in commercial community facilities. The demonstration project established proof-of-concept in reducing the kW-demand peak by the unofficial goal of 10%, with concurrent kWh savings. This section of the three volume report is a final report appendix with information on the financial management of load leveling, audit procedures, and building operating profiles.

  19. Crystal growth and characterization of third order nonlinear optical piperazinium bis(4-hydroxybenzenesulphonate) (P4HBS) single crystal

    Science.gov (United States)

    Pichan, Karuppasamy; Muthu, Senthil Pandian; Perumalsamy, Ramasamy

    2017-09-01

    The organic single crystal of piperazinium bis(4-hydroxybenzenesulphonate) (P4HBS) was grown by slow evaporation solution technique (SEST) at room temperature. The lattice parameters of the grown crystal were confirmed by single crystal X-ray diffraction analysis. Functional groups of P4HBS crystal were confirmed by FTIR spectrum analysis. The optical quality of the grown crystal was identified by the UV-Vis NIR spectrum analysis. The grown crystal has good optical transmittance in the range of 410-1100 nm. In photoluminescence spectrum, sharp emission peaks are observed, which indicates the ultraviolet (UV) emission. The photoconductivity study reveals that the grown crystal has negative photoconductive nature. The thermal behaviour of the P4HBS crystal was investigated by thermogravimetric and differential thermal analysis (TG-DTA). The mechanical stability of grown crystal was analyzed and the indentation size effect (ISE) was explained by Hays-Kendall's (HK) approach and proportional specimen resistance model (PSRM). Chemical etching study was carried out and the etch pit density (EPD) was calculated. The dielectric constant (ε‧) and dielectric loss (tan δ) as a function of frequency were measured for the grown crystal. The solid state parameters such as valence electron, plasma energy, Penn gap and Fermi energy were evaluated theoretically for the P4HBS using the empirical relation. The estimated values are used to calculate the electronic polarizability. The third-order nonlinear optical properties such as nonlinear refractive index (n2), absorption co-efficient (β) and susceptibility (χ(3)) were studied by Z-scan technique at 632.8 nm using He-Ne laser.

  20. Study of unexplained hard photon production by electrons channelled in a crystal

    CERN Multimedia

    2002-01-01

    Our preceding experiment (NA33) designed to study the pair creation process in the interaction of high energy $\\gamma$ with a crystal in alignment conditions had revealed the existence of an unexpected peak in the radiation of 150 GeV e$^{-}$ beam for E$_{\\gamma}$/E$_{e^{-}} \\simeq$ 0.85 incident along the axis of a 185 $\\mu$m. Ge crystal and the photon multiplicity for the peak events has been measured to be M $\\simeq$ 5.7.\\\\ In NA42, in a 76 $\\mu$m crystal of the same crystallographic quality, the peak nearly disappears, and the photon multiplicity at x = 0.85 is only M $\\simeq$ 2.0. \\\\ The thickness dependence of the effect shows that the extrapolated multiplicity in the peak in a very thin crystal tends to unity. The high energy radiation peak emitted by axially channeled electrons in a thick crystal is then interpreted by the radiation cooling mechanism. \\\\ The extrapolation to zero thickness of these results will allow us to extract from the data the single $\\gamma$ radiation spectrum. The comparison o...

  1. Investigating the transition from central peak to peak-ring basins using central feature volume measurements from the Global Lunar DTM 100 m

    Science.gov (United States)

    Bray, Veronica J.; Atwood-Stone, Corwin; McEwen, Alfred M.

    2012-11-01

    Several theories have been suggested to explain the transition from peak to peak-ring crater morphology. In order to explore the transition and assess the currently advocated peak-ring formation theories, we have collected measurements of central feature volumes and heights for relatively fresh lunar impact craters. We employed the Global Lunar DTM 100 m, which has the vertical precision and spatial coverage necessary to accurately measure peak and peak-ring volumes in more craters than previously possible. The similarity in both trend and magnitude of peak and peak-ring volumes suggests that peak-ring formation is closely related to the development of central peaks as crater size increases. Our data thus lends support to those peak-ring formation theories involving peak collapse.

  2. On the origin of surface imposed anisotropic growth of salicylic and acetylsalicylic acids crystals during droplet evaporation.

    Science.gov (United States)

    Przybyłek, Maciej; Cysewski, Piotr; Pawelec, Maciej; Ziółkowska, Dorota; Kobierski, Mirosław

    2015-03-01

    In this paper droplet evaporative crystallization of salicylic acid (SA) and acetylsalicylic acid (ASA) crystals on different surfaces, such as glass, polyvinyl alcohol (PVA), and paraffin was studied. The obtained crystals were analyzed using powder X-ray diffraction (PXRD) technique. In order to better understand the effect of the surface on evaporative crystallization, crystals deposited on glass were scraped off. Moreover, evaporative crystallization of a large volume of solution was performed. As we found, paraffin which is non-polar surface promotes formation of crystals morphologically similar to those obtained via bulk evaporative crystallization. On the other hand, when crystallization is carried out on the polar surfaces (glass and PVA), there is a significant orientation effect. This phenomenon is manifested by the reduction of the number of peaks in PXRD spectrum recorded for deposited on the surface crystals. Noteworthy, reduction of PXRD signals is not observed for powder samples obtained after scraping crystals off the glass. In order to explain the mechanism of carboxylic crystals growth on the polar surfaces, quantum-chemical computations were performed. It has been found that crystal faces of the strongest orientation effect can be characterized by the highest surface densities of intermolecular interactions energy (IIE). In case of SA and ASA crystals formed on the polar surfaces the most dominant faces are characterized by the highest adhesive and cohesive properties. This suggests that the selection rules of the orientation effect comes directly from surface IIE densities.

  3. Peak Power Control with an Energy Management System

    Science.gov (United States)

    2013-03-01

    start time LoseVs =tstop; %----------------------Source Parameters------------------------ %-----Source Voltage----- %Peak value used in...Load Load5Start=0.11; Load5Stop=tstop; %Rectifier Load Load6Start=0.4; Load6Stop=3; %Lose the source voltage LoseVs =tstop; %Set to 0

  4. Peak Expiratory Flow Rate in Petroleum Depot Workers and Petrol ...

    African Journals Online (AJOL)

    Peak Expiratory Flow Rate (PEFR) values in litres per minute were determined in petrol depot loaders, petrol station attendants and in control subjects. The PEFR values were 315 ± 94, 386 + 91 and 529 + 94 litres/min. in depot workers, petrol attendants and control subjects respectively. The value in the control subjects ...

  5. Effect of Gymnema inodorum on postprandial peak plasma glucose ...

    African Journals Online (AJOL)

    Gymnema inodorum (GI), a vegetable widely used in a Northern Thai food, is known for not only its health nourishing effect, but also its hypoglycemic effect. But no scientific evidence on the hypoglycemic effect of GI has ever been reported in human. In this study, the effect of GI consumption on peak plasma glucose ...

  6. Robust peak-shaving for a neighborhood with electric vehicles

    NARCIS (Netherlands)

    Gerards, Marco Egbertus Theodorus; Hurink, Johann L.

    2016-01-01

    Demand Side Management (DSM) is a popular approach for grid-aware peak-shaving. The most commonly used DSM methods either have no look ahead feature and risk deploying flexibility too early, or they plan ahead using predictions, which are in general not very reliable. To counter this, a DSM approach

  7. The post peak response of concrete for dynamic tensile loading

    NARCIS (Netherlands)

    Vegt, I.; Weerheijm, J.

    2015-01-01

    The mechanical response of concrete is represented in the load-deformation curve which shows the response up to maximum strength as well as the post-peak response up to complete failure. Dynamic tests exhibit an extensive rate effect on the tensile strength beyond loading rates of about 50 GPa/s

  8. Analytical construction of peaked solutions for the nonlinear ...

    African Journals Online (AJOL)

    We obtain analytical solutions, by way of the homotopy analysis method, to a nonlinear wave equation describing the nonlinear evolution of a vector potential of an electromagnetic pulse propagating in an arbitrary pair plasma with temperature asymmetry. As the method is analytical, we are able to construct peaked ...

  9. Peak broadening in paper chromatography and related techniques

    NARCIS (Netherlands)

    Ligny, C.L. de; Veen, N.G. van

    1972-01-01

    Peak dispersion (i.e. the separation efficiency) in thin-layer electrophoresis was investigated and compared for six different cellulose layers. The relative importance of longitudinal diffusion and of macroscopic inhomoeneities in the electric field and in the electroosmotic and sucking flow

  10. Peak expiratory flow rate and respiratory symptoms following ...

    African Journals Online (AJOL)

    Peak expiratory flow rate (PEFR) of 350 rural women aged (20-70 years) in Edo State, Nigeria who actively used wood as a source of fuel for cooking was measured. The height, chest circumference, weight and blood pressure of the women were also measured. Respiratory symptoms of cough with sputum production, ...

  11. Size-independent peak shift between normal and upconversion ...

    Indian Academy of Sciences (India)

    2014-02-12

    Feb 12, 2014 ... Abstract. In this article, we report size-dependent measurement of the shift in peak of upcon- version photoluminescence spectra compared to that of normal photoluminescence using a 800 nm femtosecond laser and its second harmonic. It has been shown that the upconversion photolumi- nescence is ...

  12. Daily peak electricity load forecasting in South Africa using a ...

    African Journals Online (AJOL)

    A multivariate adaptive regression splines (MARS) modelling approach towards daily peak electricity load forecasting in South Africa is presented in this paper for the period 2000 to 2009. MARS is a non-parametric multivariate regression method which is used in high-dimensional problems with complex model structures, ...

  13. Inaccuracy of portable peak flow meters : correction is not needed

    NARCIS (Netherlands)

    Brand, PLP; Waalkens, HJ; Duiverman, EJ; vanEssenZandvliet, EEM

    This study examined whether correction of peak expiratory flow (PEF) values for the inaccuracy of the meter would affect asthma management in 102 children (7-14 y old). PEF was recorded with a mini Wright meter twice daily for 2 weeks. As expected, measured PEF overestimated PEF level and asthma

  14. Factors influencing peak expiratory flow in teenage boys | van ...

    African Journals Online (AJOL)

    Background. Peak expiratory flow (PEF) is a useful measure of pulmonary health status and is frequently utilised in asthm, management. Reduction in PEF is usually indicative of onset (of asthma symptoms. However, use can be made of PEF values only if normal values are known. The definition of normal range is always ...

  15. Factors influencing peak expiratory flow in teenage boys | van ...

    African Journals Online (AJOL)

    Further details were provid by means of a questionnaire. Results. PEF ranged from 350 to 760 1/min, with a mean (± standard deviation (SD» of 539 ± 681/min. Factors expected to influence PEF included height and mass, where is unexpected factors included sport intensity and academic grade. A trend to reduced peak ...

  16. Vortex lattice mobility and effective pinning potentials in the peak ...

    Indian Academy of Sciences (India)

    temperature the mobility of the vortex lattice (VL) is found to be dependent on the dynamical history. ... Introduction. The peak effect (PE) in the critical current density (Jc) in both low and high temperature ... An anomalous increase is observed above an onset field Bon or temperature Ton, until Jc reaches a maximum.

  17. Characteristics of peaks of inhalation exposure to organic solvents

    NARCIS (Netherlands)

    Preller, L.; Burstyn, I.; Pater, N. de; Kromhout, H.

    2004-01-01

    Objectives: To determine which exposure metrics are sufficient to characterize 'peak' inhalation exposure to organic solvents (OS) during spraying operations. Methods: Personal exposure measurements (n = 27; duration 5-159 min) were collected during application of paints, primers, resins and glues

  18. variations of peak expiratory flow rate with anthropometric

    African Journals Online (AJOL)

    admin

    Summary: PEFR was measured in 300 healthy adult male and female staff and students of the. University of Benin, Benin City, and the College of Education, Ekiadolor, near Benin. The variations of. Peak Expiratory Flow Rate (PEFR) with respect to height (ht), weight (wt) and chest circumference (cc) were determined in ...

  19. Monsoon onset over Kerala and pre monsoon rainfall peak

    Digital Repository Service at National Institute of Oceanography (India)

    RameshKumar, M.R.; Shenoi, S.S.C.; Shankar, D.

    degrees E, from 1st March to 31 May for the years 1979 to 2001. The monsoon onset dates over Kerala, as declared by India Meteorological Department has been used in the present study. For each year, the midday of the pentad with the rainfall peak...

  20. Scheduling Non-Preemptible Jobs to Minimize Peak Demand

    Directory of Open Access Journals (Sweden)

    Sean Yaw

    2017-10-01

    Full Text Available This paper examines an important problem in smart grid energy scheduling; peaks in power demand are proportionally more expensive to generate and provision for. The issue is exacerbated in local microgrids that do not benefit from the aggregate smoothing experienced by large grids. Demand-side scheduling can reduce these peaks by taking advantage of the fact that there is often flexibility in job start times. We focus attention on the case where the jobs are non-preemptible, meaning once started, they run to completion. The associated optimization problem is called the peak demand minimization problem, and has been previously shown to be NP-hard. Our results include an optimal fixed-parameter tractable algorithm, a polynomial-time approximation algorithm, as well as an effective heuristic that can also be used in an online setting of the problem. Simulation results show that these methods can reduce peak demand by up to 50% versus on-demand scheduling for household power jobs.

  1. Single-peak solitary wave solutions for the variant Boussinesq ...

    Indian Academy of Sciences (India)

    Variant Boussinesq equations; single-peak solitary wave; solitary wave; cuspon. PACS Nos 02.30.Jr; 03.40.Kf; 52.35.Sb; 02.30.Oz; 05.45.Yv. 1. Introduction. It is well known that the exact solutions for the nonlinear wave equations can help people to understand the described process properly. So finding the exact solutions ...

  2. Optical spectroscopy of faint gigahertz peaked-spectrum sources

    NARCIS (Netherlands)

    Snellen, IAG; Schilizzi, RT; Miley, GK; de Bruyn, AG; Rottgering, HJA

    1999-01-01

    We present spectroscopic observations of a sample of faint gigahertz peaked-spectrum (GPS) radio sources drawn from the Westerbork Northern Sky Survey (WENSS), Redshifts have been determined for 19 (40 per cent) of the objects. The optical spectra of the GPS sources identified with low-redshift

  3. Knowledge, attitude and practice of physicians toward peak ...

    African Journals Online (AJOL)

    Background: Peak expiratory flow meter (PEFM) may reduce diagnostic delay and improve decision-making in asthma by providing an objective assessment of their flow and hence identify air flow variability that is essential for management of air way diseases. Objectives: This study was designed to reveal extent of ...

  4. Focal F0 peak shape and sentence mode in Swedish

    DEFF Research Database (Denmark)

    Ambrazaitis, Gilbert; Buanzur, Tuarik C.; Niebuhr, Oliver

    2015-01-01

    Shape characteristics of rising-falling accentual F0 peaks of Stockholm Swedish Accent I words in narrow focus are studied in a corpus of 287 read sentences. The corpus includes statements and three types of polar questions. Results reveal a clear effect of sentence mode on the shape of the accen...

  5. Peak Purity Assessments in Chrmatography: A Case Study of ...

    African Journals Online (AJOL)

    This work examines the applicability of different peak purity and/or homogeneity deconvolution algorithms for the evaluation of chromatographic purity and/or homogeneity in chlorpromazine hydrochloride, in the order of the algorithm\\'s increasing complexity. The methods are examined for usefulness with a view to possible ...

  6. High Peak Power Gain Switched Flared Waveguide Lasers

    Energy Technology Data Exchange (ETDEWEB)

    Chow, W.W.; Indik, R.; Koch, S.W.; Mar, Alan, Vawter, G. Allen; Moloney, J.

    1999-08-05

    We gain-switch flared waveguide lasers to obtain 14.5 W peak powers and 0.5 nJ pulse energies with laser structures compatible with the generation of diffraction-limited beams. The results are in excellent agreement with a microscopic laser model.

  7. Changes in Peak Expiratory Flow Rate, Blood Pressure and Pulse ...

    African Journals Online (AJOL)

    Changes in Peak Expiratory Flow Rate, Blood Pressure and Pulse Rate Following Ingestion of Increased Coffee Concentrations in Healthy Male Adults. ... It further indicates that, mild doses of coffee confer benefits on airflow in the lungs. While higher doses are also beneficial in improving airflow in the airway, such doses ...

  8. Standardization of I-125. Sum-Peak Coincidence Counting

    Energy Technology Data Exchange (ETDEWEB)

    Grau Carles, A.; Grau Malonda, A.

    2011-07-01

    I-125 is a nuclide which presents difficulties for standardization. The sum-peak method is one of the procedures used to standardize this radionuclide. Initially NaI (Tl)detectors and then the semiconductor detectors with higher resolution have been used.This paper describes the different methods based on the sum-peak procedure and the different expressions used to calculate the activity are deduced. We describe a general procedure for obtaining all of the above equations and many more. We analyze the influence of uncertainties in the used parameters in the uncertainty of the activity. We give a complete example of the transmission of uncertainty and the effects of correlations in the uncertainty of the activity of the sample. High-resolution spectra show an unresolved doublet of 62.0 keV and 62.8 keV. The paper presents two approaches to solve this problem. One is based on the calculation of area ratio and the sum of peak areas obtained from atomic and nuclear data, in the other we modify the equations so that the sum of the peak areas doublet, rather than its components, is present. (Author) 19 refs.

  9. Rare terrestrial orchids on Mbeya Peak, Southern Tanzania | van ...

    African Journals Online (AJOL)

    Disa walteri, Satyrium aberrans, S. comptum and S. johnsonii are rare terrestrial orchids that co-occur and flower around the same time in southern Tanzania. We found the first three of these species on Mbeya Peak in March 2005, about 45 years after they were last recorded by botanists and present the first illustration of D.

  10. Changes in Peak Expiratory Flow Rate, Blood Pressure and Pulse ...

    African Journals Online (AJOL)

    We studied the effect of different concentrations of coffee on peak expiratory flow rate (PEFR), blood pressure and pulse rate in an attempt to determine some physiological effects of coffee intake. 18 apparently healthy adult males, age range 20 to 30 years, were recruited for the study over a three day period. Varying ...

  11. Living with peak discharge uncertainty: the self-learning dike

    NARCIS (Netherlands)

    de Kok, Jean-Luc; Hoekstra, Arjen Ysbert; Sànchez-Marrè, Miquel; Béjar, Javier; Comas, Joaquim; Rizzoli, Andrea E.; Guariso, Giorgio

    2008-01-01

    Although river dikes still play a key role for flood protection in the Netherlands there is a growing interest for other measures to deal with larger peak discharges, such as lowering or widening the floodplains. Regardless of the strategy chosen the assessment of its effect on the flood risk

  12. Climate Change Impacts on Peak Electricity Consumption: US vs. Europe.

    Science.gov (United States)

    Auffhammer, M.

    2016-12-01

    It has been suggested that climate change impacts on the electric sector will account for the majority of global economic damages by the end of the current century and beyond. This finding is at odds with the relatively modest increase in climate driven impacts on consumption. Comprehensive high frequency load balancing authority level data have not been used previously to parameterize the relationship between electric demand and temperature for any major economy. Using statistical models we analyze multi-year data from load balancing authorities in the United States of America and the European Union, which are responsible for more than 90% of the electricity delivered to residential, industrial, commercial and agricultural customers. We couple the estimated response functions between total daily consumption and daily peak load with an ensemble of downscaled GCMs from the CMIP5 archive to simulate climate change driven impacts on both outcomes. We show moderate and highly spatially heterogeneous changes in consumption. The results of our peak load simulations, however, suggest significant changes in the intensity and frequency of peak events throughout the United States and Europe. As the electricity grid is built to endure maximum load, which usually occurs on the hottest day of the year, our findings have significant implications for the construction of costly peak generating and transmission capacity.

  13. Effect of Gymnema inodorum on postprandial peak plasma glucose ...

    African Journals Online (AJOL)

    USER

    2010-02-15

    Feb 15, 2010 ... on peak plasma glucose concentrations in healthy subjects was investigated. Either oral glucose ... evaluate the impact of long term GI consumption on plasma glucose concentration and liver function, fasting plasma ... activation of beta cell or enzymatic inhibition of carbohydrate absorption. Key words: ...

  14. Radio spectra of Gigahertz Peaked Spectrum radio sources

    NARCIS (Netherlands)

    deVries, WH; Barthel, PD; ODea, CP

    A well defined sample of 72 Gigahertz Peaked Spectrum radio sources is compiled, having turnover frequencies in the range of 0.5 - 10 GHz. Using this sample, the canonical GPS radio spectrum is constructed, which is found to have a constant shape, independent of AGN type, redshift or radio

  15. Cosmic Ray investigations on peak Musala in Bulgaria: A memoir

    Science.gov (United States)

    Kavlakov, S.

    2009-11-01

    A very brief historical description of the Bulgarian Cosmic Ray investigations, in the Cosmic Ray Station on peak Musala (2925 m.a.s.l.) is presented. Difficulties of the high mountain measurements that time are mentioned, together with the hard emotional and successful work done by a small staff of young Bulgarian cosmic ray scientists.

  16. Simple area determination of strongly overlapping ion mobility peaks

    Czech Academy of Sciences Publication Activity Database

    Borovcová, L.; Hermannová, M.; Pauk, V.; Šimek, M.; Havlíček, Vladimír; Lemr, Karel

    2017-01-01

    Roč. 981, AUG 15 (2017), s. 71-79 ISSN 0003-2670 Grant - others:GA MŠk(CZ) LO1305 Institutional support: RVO:61388971 Keywords : Ion mobility-mass spectrometry * Fitting of mobility peaks * Analysis of isomers Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry Impact factor: 4.950, year: 2016

  17. Peak Communication Experiences: Concept, Structure, and Sex Differences.

    Science.gov (United States)

    Gordon, Ron; Dulaney, Earl

    A study was conducted to test a "peak communication experience" (PCE) scale developed from Abraham Maslow's theory of PCE's, a model of one's highest interpersonal communication moments in terms of perceived mutual understanding, happiness, and personal fulfillment. Nineteen items, extrapolated from Maslow's model but rendered more…

  18. Knowledge, attitude and practice of nurses toward peak expiratory ...

    African Journals Online (AJOL)

    The lowest individual mean percent score was that of procedures and steps of measuring peak expiratory flow rate (39.0 ± 24.1%). The highest percent knowledge score was that of benefits of use and content instructions for teaching patients (78.3 ± 19.5% and 78.1 ±12.0%, respectively). Sociodemographic factors did not ...

  19. Knowledge, attitude and practice of physicians toward peak ...

    African Journals Online (AJOL)

    The lowest individual mean percent score was that of procedures and steps of measuring peak expiratory flow rate (49.9± 29.3%). The highest percent knowledge score was that of instructions for learning of patients about PEF (76.2 ± 11.7%). Socio-demographic factors, receiving training, availability of PEF in the health ...

  20. Steering a crystallization process to reduce crystal polydispersity; case study of insulin crystallization

    Science.gov (United States)

    Nanev, Christo N.; Petrov, Kostadin P.

    2017-12-01

    The use of the classical nucleation-growth-separation principle (NGSP) was restricted hitherto to nucleation kinetics studies only. A novel application of the NGSP is proposed. To reduce crystal polydispersity internal seeding of equally-sized crystals is suggested, the advantage being avoidance of crystal grinding, sieving and any introduction of impurities. In the present study, size distributions of grown insulin crystals are interpreted retrospectively to select the proper nucleation stage parameters. The conclusion is that when steering a crystallization process aimed at reducing crystal polydispersity, the shortest possible nucleation stage duration has to be chosen because it renders the closest size distribution of the nucleated crystal seeds. Causes of inherent propensity to increasing crystal polydispersity during prolonged growth are also explored. Step sources of increased activity, present in some crystals while absent in others, are pointed as the major polydispersity cause. Insulin crystal morphology is also considered since it determines the dissolution rate of a crystalline medicine.

  1. Peak Dose Assessment for Proposed DOE-PPPO Authorized Limits

    Energy Technology Data Exchange (ETDEWEB)

    Maldonado, Delis [Oak Ridge Institute for Science and Education, Oak Ridge, TN (United States). Independent Environmental Assessment and Verification Program

    2012-06-01

    The Oak Ridge Institute for Science and Education (ORISE), a U.S. Department of Energy (DOE) prime contractor, was contracted by the DOE Portsmouth/Paducah Project Office (DOE-PPPO) to conduct a peak dose assessment in support of the Authorized Limits Request for Solid Waste Disposal at Landfill C-746-U at the Paducah Gaseous Diffusion Plant (DOE-PPPO 2011a). The peak doses were calculated based on the DOE-PPPO Proposed Single Radionuclides Soil Guidelines and the DOE-PPPO Proposed Authorized Limits (AL) Volumetric Concentrations available in DOE-PPPO 2011a. This work is provided as an appendix to the Dose Modeling Evaluations and Technical Support Document for the Authorized Limits Request for the C-746-U Landfill at the Paducah Gaseous Diffusion Plant, Paducah, Kentucky (ORISE 2012). The receptors evaluated in ORISE 2012 were selected by the DOE-PPPO for the additional peak dose evaluations. These receptors included a Landfill Worker, Trespasser, Resident Farmer (onsite), Resident Gardener, Recreational User, Outdoor Worker and an Offsite Resident Farmer. The RESRAD (Version 6.5) and RESRAD-OFFSITE (Version 2.5) computer codes were used for the peak dose assessments. Deterministic peak dose assessments were performed for all the receptors and a probabilistic dose assessment was performed only for the Offsite Resident Farmer at the request of the DOE-PPPO. In a deterministic analysis, a single input value results in a single output value. In other words, a deterministic analysis uses single parameter values for every variable in the code. By contrast, a probabilistic approach assigns parameter ranges to certain variables, and the code randomly selects the values for each variable from the parameter range each time it calculates the dose (NRC 2006). The receptor scenarios, computer codes and parameter input files were previously used in ORISE 2012. A few modifications were made to the parameter input files as appropriate for this effort. Some of these changes

  2. Introduction to protein crystallization.

    Science.gov (United States)

    McPherson, Alexander; Gavira, Jose A

    2014-01-01

    Protein crystallization was discovered by chance about 150 years ago and was developed in the late 19th century as a powerful purification tool and as a demonstration of chemical purity. The crystallization of proteins, nucleic acids and large biological complexes, such as viruses, depends on the creation of a solution that is supersaturated in the macromolecule but exhibits conditions that do not significantly perturb its natural state. Supersaturation is produced through the addition of mild precipitating agents such as neutral salts or polymers, and by the manipulation of various parameters that include temperature, ionic strength and pH. Also important in the crystallization process are factors that can affect the structural state of the macromolecule, such as metal ions, inhibitors, cofactors or other conventional small molecules. A variety of approaches have been developed that combine the spectrum of factors that effect and promote crystallization, and among the most widely used are vapor diffusion, dialysis, batch and liquid-liquid diffusion. Successes in macromolecular crystallization have multiplied rapidly in recent years owing to the advent of practical, easy-to-use screening kits and the application of laboratory robotics. A brief review will be given here of the most popular methods, some guiding principles and an overview of current technologies.

  3. Spherical crystallization: direct spherical agglomeration of salicylic Acid crystals during crystallization.

    Science.gov (United States)

    Kawashima, Y; Okumura, M; Takenaka, H

    1982-06-04

    Direct spherical agglomeration of salicylic acid crystals during crystallization is described. The needle-like salicylic acid crystals simultaneously form and agglomerate in a mixture of three partially miscible liquids, such as water, ethanol, and chloroform, with agitation. The agglomerates can be made directly into tablets because of their excellent flowability. Spherical crystallization could eliminate the usual separate agglomeration step after crystallization and may be adaptable to other pharmaceutical and chemical systems.

  4. Comparative Analysis of Thermal Behavior, Isothermal Crystallization Kinetics and Polymorphism of Palm Oil Fractions

    Directory of Open Access Journals (Sweden)

    Bing Li

    2013-01-01

    Full Text Available Thermal behavior of palm stearin (PS and palm olein (PO was explored by monitoring peak temperature transitions by differential scanning calorimetry (DSC. The fatty acid composition (FAC, isothermal crystallization kinetics studied by pulsed Nuclear Magnetic Resonance (pNMR and isothermal microstructure were also compared. The results indicated that the fatty acid composition had an important influence on the crystallization process. PS and PO both exhibited more multiple endotherms than exotherms which showed irregular peak shapes. An increasing in cooling rate, generally, was associated with an increase in peak size. Application of the Avaimi equation to isothermal crystallization of PS and PO revealed different nucleation and growth mechanisms based on the Avrami exponents. PS quickly reached the end of crystallization because of more saturated triacylglycerol (TAG. The Avrami index of PS were the same as PO under the same isothermal condition at lower temperatrue, indicating that the crystallization mechanism of the two samples based on super-cooling state were the same. According to the polarized light microscope (PLM images, crystal morphology of PS and PO was different. With the temperature increased, the structure of crystal network of both PS and PO gradually loosened.

  5. Hydrothermal growth and characterization of aluminum-doped ZnO bulk crystals

    Science.gov (United States)

    Wang, Buguo; Mann, Matthew; Claflin, Bruce; Snure, Michael; Look, David C.

    2013-03-01

    Bulk ZnO crystals were grown by the hydrothermal technique with Al2O3 added to the solution in an attempt to obtain Al-doped ZnO crystals. Aluminum and indium co-doped ZnO were also grown by the same technique. Adding Al2O3 to the growth solution has a significant impact on the ZnO growth ⎯ either preventing overgrowth and dissolving the seed growth or degrading the crystalline quality; nevertheless, the resulting crystals of both Al:ZnO and Al/In:ZnO are highly conductive, similar to In and Ga doped ZnO crystals, with a resistivity approaching 0.01 Ω cm, as revealed by temperature-dependent Hall-effect measurements. Photoluminescence spectra at 18 K show Al0-bound-exciton peak energies of 3.3604 eV on the Zn face and 3.3609 eV on the O face for the Al-doped ZnO crystals. Similarly both an Al0- bound-exciton peak at 3.3604 eV and an In0-bound-exciton peak at 3.3575 eV were found on the Al/In-co-doped crystals. The electrical properties of all group III doped ZnO crystals grown hydrothermally are compared with each other and with Al:ZnO obtained by other growth methods.

  6. Effect of Metal Dopant on Ninhydrin—Organic Nonlinear Optical Single Crystals

    Directory of Open Access Journals (Sweden)

    R. S. Sreenivasan

    2013-01-01

    Full Text Available In the present work, metal (Cu2+-substituted ninhydrin single crystals were grown by slow evaporation method. The grown crystals have been subjected to single crystal XRD, powder X-ray diffraction, FTIR, dielectric and SHG studies. Single crystal X-ray diffraction analysis reveals that the compound crystallizes in monoclinic system with noncentrosymmetric space group P21 with lattice parameters a=11.28 Å, b=5.98 Å, c=5.71 Å, α=90∘, β=98.57, γ=90∘, and V=381 (Å3, which agrees very well with the reported value. The sharp and strong peaks in the powder X-ray diffraction pattern confirm the good crystallinity of the grown crystals. The presence of dopants marginally altered the lattice parameters without affecting the basic structure of the crystal. The UV-Vis transmittance spectrum shows that the crystal has a good optical transmittance in the entire visible region with lower cutoff wavelength 314 nm. The vibrational frequencies of various functional groups in the crystals have been derived from FT-IR analysis. Based on the shifts in the vibrations, the presence of copper in the lattice of the grown crystal is clearly established from the pure ninhydrin crystals. Both dielectric constant and dielectric loss decrease with the increase in frequency. The second harmonic generation efficiency was measured by employing powder Kurtz method.

  7. Thermoluminescence response of a mixed ternary alkali halide crystals exposed to gamma rays

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez M, R.; Perez S, R. [Universidad de Sonora, Departamento de Investigacion en Fisica, Apdo. Postal 5-088, 83190 Hermosillo, Sonora (Mexico); Vazquez P, G.; Riveros, H. [UNAM, Instituto de Fisica, Apdo. Postal 20-364, 01000 Mexico D. F. (Mexico); Gonzalez M, P., E-mail: mijangos@cifus.uson.mx [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2014-08-15

    Ionic crystals, mainly alkali halide crystals have been the subject of intense research for a better understanding of the luminescence properties of defects induced by ionizing radiation. The defects in crystals can be produced in appreciable concentration due to elastic stresses, radiation, and addition of impurities. These defects exhibit remarkable thermoluminescence properties. This work is concerned with the Tl properties of a ternary alkali halide crystal after being irradiated with gamma and beta rays. It has been found that the Tl glow peak of the crystal follows a rule of average associated to the Tl Temperatures of the components of the mixture, similarly to the response of europium doped binary mixed crystals KCl{sub x}KBr{sub 1-x} and KBr{sub x}RbBr{sub 1-x}. (Author)

  8. Photonic Crystal Fibres

    DEFF Research Database (Denmark)

    Bjarklev, Anders Overgaard; Broeng, Jes; Sanchez Bjarklev, Araceli

    Photonic crystal fibres represent one of the most active research areas today in the field of optics. The diversity of applications that may be addressed by these fibres and their fundamental appeal, by opening up the possibility of guiding light in a radically new way compared to conventional...... optical fibres, have spun an interest from almost all areas of optics and photonics. The aim of this book is to provide an understanding of the different types of photonic crystal fibres and to outline some of the many new and exciting applications that these fibres offer. The book is intended for both...... bandgap structures and thoughts of inspiration from microstructures in nature, as well as classification of the various photonic crystal fibres, theoretical tools for analysing the fibres and methods of their production. Finally, the book points toward some of the many future applications, where photonic...

  9. Photonic Crystal Fibres

    DEFF Research Database (Denmark)

    Bjarklev, Anders Overgaard; Broeng, Jes; Sanchez Bjarklev, Araceli

    Photonic crystal fibres represent one of the most active research areas today in the field of optics. The diversity of applications that may be addressed by these fibres and their fundamental appeal, by opening up the possibility of guiding light in a radically new way compared to conventional...... optical fibres, have spun an interest from almost all areas of optics and photonics. The aim of this book is to provide an understanding of the different types of photonic crystal fibres and to outline some of the many new and exciting applications that these fibres offer. The book is intended for both...... readers with a general interest in photonic crystals, as well as for scientists who are entering the field and desire a broad overview as well as a solid starting point for further specialized stuides. Teh book, therefore, covers bothe general aspects such as the link from classical optics to photonic...

  10. Photonic Crystal Fibres

    DEFF Research Database (Denmark)

    Bjarklev, Anders Overgaard; Broeng, Jes; Sanchez Bjarklev, Araceli

    bandgap structures and thoughts of inspiration from microstructures in nature, as well as classification of the various photonic crystal fibres, theoretical tools for analysing the fibres and methods of their production. Finally, the book points toward some of the many future applications, where photonic......Photonic crystal fibres represent one of the most active research areas today in the field of optics. The diversity of applications that may be addressed by these fibres and their fundamental appeal, by opening up the possibility of guiding light in a radically new way compared to conventional...... optical fibres, have spun an interest from almost all areas of optics and photonics. The aim of this book is to provide an understanding of the different types of photonic crystal fibres and to outline some of the many new and exciting applications that these fibres offer. The book is intended for both...

  11. Revisiting the Correlations of Peak Luminosity with Spectral Lag and Peak Energy of the Observed Gamma-ray Bursts

    Directory of Open Access Journals (Sweden)

    Yun-A Jo

    2016-12-01

    Full Text Available An analysis of light curves and spectra of observed gamma-ray bursts in gamma-ray ranges is frequently demanded because the prompt emission contains immediate details regarding the central engine of gamma-ray bursts (GRBs. We have revisited the relationship between the collimation-corrected peak luminosity and the spectral lag, investigating the lag-luminosity relationships in great detail by focusing on spectral lags resulting from all possible combinations of channels. Firstly, we compiled the opening angle data and demonstrated that the distribution of opening angles of 205 long GRBs is represented by a double Gaussian function having maxima at ~ 0.1 and ~ 0.3 radians. We confirmed that the peak luminosity and the spectral lag are anti-correlated, both in the observer frame and in the source frame. We found that, in agreement with our previous conclusion, the correlation coefficient improves significantly in the source frame. It should be noted that spectral lags involving channel 2 (25-50 keV yield high correlation coefficients, where Swift/Burst Alert Telescope (BAT has four energy channels (channel 1: 15-25 keV, channel 2: 25-50 keV, channel 3: 50-100 keV, channel 4: 100-200 keV. We also found that peak luminosity is positively correlated with peak energy.

  12. Hurricane Mitch: Peak Discharge for Selected River Reachesin Honduras

    Science.gov (United States)

    Smith, Mark E.; Phillips, Jeffrey V.; Spahr, Norman E.

    2002-01-01

    Hurricane Mitch began as a tropical depression in the Caribbean Sea on 22 October 1998. By 26 October, Mitch had strengthened to a Category 5 storm as defined by the Saffir-Simpson Hurricane Scale (National Climate Data Center, 1999a), and on 27 October was threatening the northern coast of Honduras (fig. 1). After making landfall 2 days later (29 October), the storm drifted south and west across Honduras, wreaking destruction throughout the country before reaching the Guatemalan border on 31 October. According to the National Climate Data Center of the National Oceanic and Atmospheric Administration (National Climate Data Center, 1999b), Hurricane Mitch ranks among the five strongest storms on record in the Atlantic Basin in terms of its sustained winds, barometric pressure, and duration. Hurricane Mitch also was one of the worst Atlantic storms in terms of loss of life and property. The regionwide death toll was estimated to be more than 9,000; thousands of people were reported missing. Economic losses in the region were more than $7.5 billion (U.S. Agency for International Development, 1999). Honduras suffered the most widespread devastation during the storm. More than 5,000 deaths, and economic losses of more than $4 billion, were reported by the Government of Honduras. Honduran officials estimated that Hurricane Mitch destroyed 50 years of economic development. In addition to the human and economic losses, intense flooding and landslides scarred the Honduran landscape - hydrologic and geomorphologic processes throughout the country likely will be affected for many years. As part of the U.S. Government's response to the disaster, the U.S. Geological Survey (USGS) conducted post-flood measurements of peak discharge at 16 river sites throughout Honduras (fig. 2). Such measurements, termed 'indirect' measurements, are used to determine peak flows when direct measurements (using current meters or dye studies, for example) cannot be made. Indirect measurements of

  13. Ionoacoustic characterization of the proton Bragg peak with submillimeter accuracy

    Energy Technology Data Exchange (ETDEWEB)

    Assmann, W., E-mail: walter.assmann@lmu.de; Reinhardt, S.; Lehrack, S.; Edlich, A.; Thirolf, P. G.; Parodi, K. [Department for Medical Physics, Ludwig-Maximilians-Universität München, Am Coulombwall 1, Garching 85748 (Germany); Kellnberger, S.; Omar, M.; Ntziachristos, V. [Institute for Biological and Medical Imaging, Technische Universität München and Helmholtz Zentrum München, Ingolstädter Landstrasse 1, Neuherberg 85764 (Germany); Moser, M.; Dollinger, G. [Institute for Applied Physics and Measurement Technology, Universität der Bundeswehr, Werner-Heisenberg-Weg 39, Neubiberg 85577 (Germany)

    2015-02-15

    Purpose: Range verification in ion beam therapy relies to date on nuclear imaging techniques which require complex and costly detector systems. A different approach is the detection of thermoacoustic signals that are generated due to localized energy loss of ion beams in tissue (ionoacoustics). Aim of this work was to study experimentally the achievable position resolution of ionoacoustics under idealized conditions using high frequency ultrasonic transducers and a specifically selected probing beam. Methods: A water phantom was irradiated by a pulsed 20 MeV proton beam with varying pulse intensity and length. The acoustic signal of single proton pulses was measured by different PZT-based ultrasound detectors (3.5 and 10 MHz central frequencies). The proton dose distribution in water was calculated by Geant4 and used as input for simulation of the generated acoustic wave by the matlab toolbox k-WAVE. Results: In measurements from this study, a clear signal of the Bragg peak was observed for an energy deposition as low as 10{sup 12} eV. The signal amplitude showed a linear increase with particle number per pulse and thus, dose. Bragg peak position measurements were reproducible within ±30 μm and agreed with Geant4 simulations to better than 100 μm. The ionoacoustic signal pattern allowed for a detailed analysis of the Bragg peak and could be well reproduced by k-WAVE simulations. Conclusions: The authors have studied the ionoacoustic signal of the Bragg peak in experiments using a 20 MeV proton beam with its correspondingly localized energy deposition, demonstrating submillimeter position resolution and providing a deep insight in the correlation between the acoustic signal and Bragg peak shape. These results, together with earlier experiments and new simulations (including the results in this study) at higher energies, suggest ionoacoustics as a technique for range verification in particle therapy at locations, where the tumor can be localized by ultrasound

  14. Nonlinear Photonic Crystal Fibers

    DEFF Research Database (Denmark)

    Hansen, Kim Per

    2004-01-01

    Despite the general recession in the global economy and the collapse of the optical telecommunication market, research within specialty fibers is thriving. This is, more than anything else, due to the technology transition from standard all-glass fibers to photonic crystal fibers, which, instead...... in 1996, and are today on their way to become the dominating technology within the specialty fiber field. Whether they will replace the standard fiber in the more traditional areas like telecommunication transmission, is not yet clear, but the nonlinear photonic crystal fibers are here to stay....

  15. Time crystals: a review

    Science.gov (United States)

    Sacha, Krzysztof; Zakrzewski, Jakub

    2018-01-01

    Time crystals are time-periodic self-organized structures postulated by Frank Wilczek in 2012. While the original concept was strongly criticized, it stimulated at the same time an intensive research leading to propositions and experimental verifications of discrete (or Floquet) time crystals—the structures that appear in the time domain due to spontaneous breaking of discrete time translation symmetry. The struggle to observe discrete time crystals is reviewed here together with propositions that generalize this concept introducing condensed matter like physics in the time domain. We shall also revisit the original Wilczek’s idea and review strategies aimed at spontaneous breaking of continuous time translation symmetry.

  16. Liquid crystals fundamentals

    CERN Document Server

    Singh, Shri

    2001-01-01

    Liquid crystals are partially ordered systems without a rigid, long-range structure. The study of these materials covers a wide area: chemical structure, physical properties and technical applications. Due to their dual nature - anisotropic physical properties of solids and rheological behavior of liquids - and easy response to externally applied electric, magnetic, optical and surface fields liquid crystals are of greatest potential for scientific and technological applications. The subject has come of age and has achieved the status of being a very exciting interdisciplinary field of scienti

  17. MUDMASTER: A Program for Calculating Crystalline Size Distributions and Strain from the Shapes of X-Ray Diffraction Peaks

    Science.gov (United States)

    Eberl, D.D.; Drits, V.A.; Środoń, Jan; Nüesch, R.

    1996-01-01

    Particle size may strongly influence the physical and chemical properties of a substance (e.g. its rheology, surface area, cation exchange capacity, solubility, etc.), and its measurement in rocks may yield geological information about ancient environments (sediment provenance, degree of metamorphism, degree of weathering, current directions, distance to shore, etc.). Therefore mineralogists, geologists, chemists, soil scientists, and others who deal with clay-size material would like to have a convenient method for measuring particle size distributions. Nano-size crystals generally are too fine to be measured by light microscopy. Laser scattering methods give only average particle sizes; therefore particle size can not be measured in a particular crystallographic direction. Also, the particles measured by laser techniques may be composed of several different minerals, and may be agglomerations of individual crystals. Measurement by electron and atomic force microscopy is tedious, expensive, and time consuming. It is difficult to measure more than a few hundred particles per sample by these methods. This many measurements, often taking several days of intensive effort, may yield an accurate mean size for a sample, but may be too few to determine an accurate distribution of sizes. Measurement of size distributions by X-ray diffraction (XRD) solves these shortcomings. An X-ray scan of a sample occurs automatically, taking a few minutes to a few hours. The resulting XRD peaks average diffraction effects from billions of individual nano-size crystals. The size that is measured by XRD may be related to the size of the individual crystals of the mineral in the sample, rather than to the size of particles formed from the agglomeration of these crystals. Therefore one can determine the size of a particular mineral in a mixture of minerals, and the sizes in a particular crystallographic direction of that mineral.

  18. The 35 kilowatt peak photovoltaic power system, phase 1

    Science.gov (United States)

    Stary, M. L.; Burgess, D.

    1981-11-01

    A 35 kilowatt peak photovoltaic power system is being implemented at a new industrial park in the city of San Bernardino, California. Phase I of this program includes the establishment and operation of a test station to obtain site specific weather data and to operate three types of photovoltaic arrays, fixed flat plate, tracking flat plate and concentrator, and system analysis and design o the Phase II, 35 kilowatt peak power system for installation on the roof of an 18,000 square foot, light manufacturing facility. An important aspect of the program is the establishment of a training and safety program to acquiant unskilled, minority workers with the operation and maintenance of photovoltaic power systems. The results of the Phase I activity are presented.

  19. Multiple peaks of species abundance distributions induced by sparse interactions

    CERN Document Server

    Obuchi, Tomoyuki; Tokita, Kei

    2016-01-01

    We investigate the replicator dynamics with "sparse" symmetric interactions which represent specialist-specialist interactions in ecological communities. By considering a large self interaction $u$, we conduct a perturbative expansion which manifests that the nature of the interactions has a direct impact on the species abundance distribution. The central results are all species coexistence in a realistic range of the model parameters and that a certain discrete nature of the interactions induces multiple peaks in the species abundance distribution, providing the possibility of theoretically explaining multiple peaks observed in various field studies. To get more quantitative information, we also construct a non-perturbative theory which becomes exact on tree-like networks if all the species coexist, providing exact critical values of $u$ below which extinct species emerge. Numerical simulations in various different situations are conducted and they clarify the robustness of the presented mechanism of all spe...

  20. Evaluation of peaking factors uncertainty for CASMO-3

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kang Suk; Song, Jae Seung; Kim, Yong Rae; Ji, Seong Kyun [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1996-02-01

    This document evaluates the pin-to-box factor uncertainty based on using the CASMO-3 with 40-group J-library. Five CE criticals performed by Westinghouse, two by B and W and four RPI criticals were analyzed, using cross sections by CASMO-3. DOT was used for the core calculation. THis is one hof series of efforts to verify ADONIS procedure which is a new core design package under development by KAERI. The expected outcome of this analysis is CASMO-3 pin peak uncertainty applicable to CE type fuel assembly design. The evaluated uncertainty of peaking factors for CASMO-3 was 1.863%. 21 tabs., 23 figs., 12 refs. (Author) .new.

  1. Simulation of Peak Flows Using Remote Sensing Systems

    Science.gov (United States)

    Magaña Hernández, F.; Ba, K. M.; Guerra-Cobián, V.

    2013-05-01

    In this study we utilized remotely sensed data (radar and satellite precipitation products) to simulate the peak discharges of some storm events of the Escondido River. This is a poorly gauged watershed located in Northern Mexico, in the State of Coahuila and is a sub-basin of Rio Bravo, known also as Río Grande. The radar data are from NOAA (Radar KDFX located in Laughlin Air Force Base, Texas). We used two satellite product estimates PERSIANN and CMORPH. These three estimated precipitation products have been compared using the hydrologic model HEC-HMS to simulate the peak discharge. The results of the simulations show the importance of the use of this type of data in hydrologic modeling.

  2. T(peak)T(end) interval in long QT syndrome

    DEFF Research Database (Denmark)

    Kanters, Jørgen Kim; Haarmark, Christian; Vedel-Larsen, Esben

    2008-01-01

    BACKGROUND: The T(peak)T(end) (T(p)T(e)) interval is believed to reflect the transmural dispersion of repolarization. Accordingly, it should be a risk factor in long QT syndrome (LQTS). The aim of the study was to determine the effect of genotype on T(p)T(e) interval and test whether it was related...... to the occurrence of syncope. METHODS: Electrocardiograms were taken in 95 patients with LQTS drawn from the Danish long QT registry (44 patients with KvLQT1, 43 with HERG, and 8 with SCN5A mutations) and manually evaluated for the QT, QT(peak), and RR interval. RESULTS AND CONCLUSION: (1) T(p)T(e) cannot be used...

  3. General Merrill A. McPeak Leadership and Organizational Change

    Science.gov (United States)

    2001-06-01

    GENERAL MERRILL A. MCPEAK LEADERSHIP AND ORGANIZATIONAL CHANGE BY MAJOR THOMAS A. BUSSIERE A THESIS PRESENTED TO THE...Covered (from... to) - Title and Subtitle General Merrill A. McPeak Leadership and Organizational Change Contract Number Grant Number Program Element...General McPeak�s leadership. The sections of each case focus on the particular issues associated with organizational change and leadership. The

  4. Peak Voltage Measurements Using Standard Sphere Gap Method

    Directory of Open Access Journals (Sweden)

    Constantin Ungureanu

    2014-01-01

    Full Text Available The paper presents a measurement system of peak value of high voltage (H.V. using 150 mm diameter sphere gap, disposed in vertical position. Experimental breakdown results have been compared with standard values at atmospheric reference conditions STC (20°C, 101.3 kPa, or 760 mmHg. The main experimental and theoretical characteristics are presented.

  5. Sustained fixation induced changes in phoria and convergence peak velocity.

    Directory of Open Access Journals (Sweden)

    Eun H Kim

    Full Text Available PURPOSE: This study sought to investigate the influence of phoria adaptation on convergence peak velocity from responses located at different initial vergence positions. METHODS: Symmetrical 4° convergence step responses and near dissociated phoria (measured at 40 cm from the subject's midline were recorded from six subjects with normal binocular vision using an infrared limbus tracking system with a haploscope. Two different sustained fixations (1° and 16° convergent rotation along the subject's midline were used to study whether phoria had an influence on the peak velocity of convergence responses located at two initial vergence positions (1° or 'far' steps and 12° or 'near' steps. RESULTS: Phoria was significantly adapted after a sustained fixation task at near (16° and far (1° (p<0.002. A repeated measures ANOVA showed that convergence far steps were significantly faster than the near steps (p<0.03. When comparing convergence steps with the same initial vergence position, steps measured after near phoria adaptation were faster than responses after far adaptation (p<0.02. A regression analysis demonstrated that the change in phoria and the change in convergence peak velocity were significantly correlated for the far convergence steps (r = 0.97, p = 0.001. A weaker correlation was observed for the near convergence steps (r = 0.59, p = 0.20. CONCLUSION: As a result of sustained fixation, phoria was adapted and the peak velocity of the near and far convergence steps was modified. This study has clinical considerations since prisms, which evoke phoria adaptation, can be prescribed to help alleviate visual discomfort. Future investigations should include a systematic study of how prisms may influence convergence and divergence eye movements for those prescribed with prisms within their spectacles.

  6. Sustained Fixation Induced Changes in Phoria and Convergence Peak Velocity

    Science.gov (United States)

    Kim, Eun H.; Vicci, Vincent R.; Han, Sang J.; Alvarez, Tara L.

    2011-01-01

    Purpose This study sought to investigate the influence of phoria adaptation on convergence peak velocity from responses located at different initial vergence positions. Methods Symmetrical 4° convergence step responses and near dissociated phoria (measured at 40 cm from the subject's midline) were recorded from six subjects with normal binocular vision using an infrared limbus tracking system with a haploscope. Two different sustained fixations (1° and 16° convergent rotation along the subject's midline) were used to study whether phoria had an influence on the peak velocity of convergence responses located at two initial vergence positions (1° or ‘far’ steps and 12° or ‘near’ steps). Results Phoria was significantly adapted after a sustained fixation task at near (16°) and far (1°) (pvergence position, steps measured after near phoria adaptation were faster than responses after far adaptation (p<0.02). A regression analysis demonstrated that the change in phoria and the change in convergence peak velocity were significantly correlated for the far convergence steps (r = 0.97, p = 0.001). A weaker correlation was observed for the near convergence steps (r = 0.59, p = 0.20). Conclusion As a result of sustained fixation, phoria was adapted and the peak velocity of the near and far convergence steps was modified. This study has clinical considerations since prisms, which evoke phoria adaptation, can be prescribed to help alleviate visual discomfort. Future investigations should include a systematic study of how prisms may influence convergence and divergence eye movements for those prescribed with prisms within their spectacles. PMID:21698110

  7. Peak signal-to-noise ratio revisited: Is simple beautiful?

    DEFF Research Database (Denmark)

    Korhonen, Jari; You, Junyong

    2012-01-01

    Heavy criticism has been directed against using peak signal-to-noise ratio (PSNR) as a full reference quality metric for digitally processed images and video, since many studies have shown a weak correlation between subjective quality scores and the respective PSNR values. In this paper, we show...... quality models known from the literature. Therefore, the use of PSNR may be justified for comparative quality assessment with fixed content....

  8. Effects of impact mixing contamination on lunar central peak spectra

    Science.gov (United States)

    Crites, S.; Ohtake, M.; Lucey, P. G.; Haruyama, J.; Lemelin, M.

    2016-12-01

    The impact cratering process acts as a natural drill into the lunar surface, exposing material from depth within the crust and providing a valuable three-dimensional view of lunar stratigraphy. In particular, remote sensing studies of crater central peak mineralogy, pioneered by Pieters (1982) and subsequently extended by many, have provided key insights into the composition of the lunar crust. However, the same cratering processes that expose subsurface material also act to obscure the true signal by contributing to extensive mixing of the surface at all scales as well as producing impact melt. One approach to eliminating potentially mixed or contaminated regions is by careful visual examination and geologic mapping using high spatial resolution imagery. However, for large-scale surveys, a quantitative metric for narrowing data to areas less affected by mixing and contamination may be needed in order to ensure only the most reliable spectra are interpreted. Mass wasting may provide a mechanism for revealing fresh in-situ material to be analyzed; steep slopes, extreme optical maturity values, and high rock abundance are three possible discriminators for identifying these fresh surfaces for large-scale spectral analyses. Taking two central peak craters (Jackson and Tycho), we examine the variation in spectral parameters and modeled mineral composition using Kaguya Multiband Imager data between 1) all central peak pixels, and 2) pixels limited to fresh or unmixed areas as identified by our three parameters (LOLA/TC slope, Diviner rock abundance, OMAT). A significant difference in mineral composition between the two regions would imply that average central peak mineralogy may not be an appropriate proxy for crustal composition at depth. This investigation will also provide insight into whether a quantitative metric can be developed to `mask' regions most likely to be mixed or contaminated, and limit the results of global studies to the most relevant crustal samples.

  9. DOES EFFICIENT PEAK-LOAD PRICING INVOLVE DISCRIMINATION,

    Science.gov (United States)

    It is contended that the efficient price differences in a peak-load situation shown in Steiner’s analysis are not discriminatory because they are e ere equal to the differences in the marginal cost of serving the classesessasses of customers involved. By marginal cost is meant, ultimately, the marginal opportunity cost--the value set upon the resource by the customer in the most valuable alternative use being sacrificed.

  10. quasi hyperrigidity and weak peak points for non-commutative ...

    Indian Academy of Sciences (India)

    7

    space of C(X), separating points and containing the identity of C(X). A point x0 ∈ X is a peak point of G if there exists a g .... identity of the C∗-algebra A) on a Hilbert space H is finite if and only if for every isometry V in B(H), the condition V ∗π(a)V ...... pitality and academic support. The authors are thankful to Craig Kleski for ...

  11. Peak height velocity in anthropometry and body composition of students

    OpenAIRE

    Hobold, Edilson; Flores,Lucinar Jupir Forner; Brandt,Ricardo; Mazzardo Junior, Oldemar; Arruda, Miguel de

    2017-01-01

    Abstract The aim of this study was to analyze the age of Peak Height Velocity (PHV), anthropometric variables and body composition of students from the western state of Paraná. he study included 1,011 male students aged 12-15 years from 11 municipalities located around the Itaipu lake. Anthropometric and body composition variables were obtained according to international criteria. Biological maturation was determined by age of PHV and for the purpose of analysis, it was categorized into devel...

  12. Degradation of the Bragg peak due to inhomogeneities.

    Science.gov (United States)

    Urie, M; Goitein, M; Holley, W R; Chen, G T

    1986-01-01

    The rapid fall-off of dose at the end of range of heavy charged particle beams has the potential in therapeutic applications of sparing critical structures just distal to the target volume. Here we explored the effects of highly inhomogeneous regions on this desirable depth-dose characteristic. The proton depth-dose distribution behind a lucite-air interface parallel to the beam was bimodal, indicating the presence of two groups of protons with different residual ranges, creating a step-like depth-dose distribution at the end of range. The residual ranges became more spread out as the interface was angled at 3 degrees, and still more at 6 degrees, to the direction of the beam. A second experiment showed little significant effect on the distal depth-dose of protons having passed through a mosaic of teflon and lucite. Anatomic studies demonstrated significant effects of complex fine inhomogeneities on the end of range characteristics. Monoenergetic protons passing through the petrous ridges and mastoid air cells in the base of skull showed a dramatic degradation of the distal Bragg peak. In beams with spread out Bragg peaks passing through regions of the base of skull, the distal fall-off from 90 to 20% dose was increased from its nominal 6 to well over 32 mm. Heavy ions showed a corresponding degradation in their ends of range. In the worst case in the base of skull region, a monoenergetic neon beam showed a broadening of the full width at half maximum of the Bragg peak to over 15 mm (compared with 4 mm in a homogeneous unit density medium). A similar effect was found with carbon ions in the abdomen, where the full width at half maximum of the Bragg peak (nominally 5.5 mm) was found to be greater than 25 mm behind gas-soft-tissue interfaces. We address the implications of these data for dose computation with heavy charged particles.

  13. Probing Cosmology with Weak Lensing Peak Counts and Minkowski Functionals

    Science.gov (United States)

    Kratochvil, Jan Michael; Wang, S.; Lim, E. A.; Haiman, Z.; May, M.

    2010-05-01

    The new method of counting peaks in weak lensing (WL) maps, as a function of their height, to probe models of dark energy and to constrain cosmological parameters offers advantages over similar, more traditional statistics like cluster counts: Because peaks can be identified in two-dimensional WL maps directly, they can provide constraints which are free from potential selection effects and biases involved in identifying and determining the masses of galaxy clusters. Our pilot study (Kratochvil, Haiman, May 2009), where we investigated three cosmological models with different constant values of the dark energy equation of state parameter w=-0.8, w=-1, w=-1.2 and with a fixed normalization of the primordial power spectrum, revealed a parameter sensitivity of w which warrants a numerically very costly in-depth study when marginalization over other uncertain cosmological parameters is included. Towards that goal, we present recent results from a new, extensive simulation suite of ninety 5123-particle N-body simulations, run on New York Blue at BNL, allowing us to vary several cosmological parameters individually and yielding vastly improved statistics. Studies have shown that weak lensing maps likely contain as much information in the nonlinear regime as in the linear one. While being a powerful probe of the nonlinear regime, weak lensing peak counts capture by definition only a subset of the total available information in the convergence maps. In particular, we found that relatively low-amplitude peaks account for most of the parameter sensitivity detected, hinting to a more complicated structure. Therefore, we extend our work by probing the morphology of the maps with Minkowski functionals, in our quest to extract the most possible information from the nonlinear aspects of large-scale structure formation.

  14. peak expiratory flow as a surrogate for health relat

    African Journals Online (AJOL)

    2014-06-01

    Jun 1, 2014 ... was 68.4 (8.9) years and 21.4 (4.6) kg/m2 respectively and 96% of the patients were in moderate-severe ... Though the peak flow meter have been dismissed as unreliable for diagnosing COPD,5,6 recent .... COPD,21 neither is it time efficient or easier to per- form.22. As a result, PEF measurements, even ...

  15. Bridgman growth and scintillation properties of calcium tungstate single crystal

    Science.gov (United States)

    Wang, Zhenhai; Jiang, Linwen; Chen, Yaping; Chen, Peng; Chen, Hongbing; Mao, Rihua

    2017-12-01

    CaWO4 single crystal with large size was grown by Bridgman method. The results of transmission spectra show that the transmittance of CaWO4 crystal reaches 79-85% in 320-800 nm wavelength range. The refraction index is near 1.80 in visible and infrared region. CaWO4 crystal shows a broad emission band centered at 424 nm under X-ray excitation and centered at 416 nm under ultraviolet (λex = 280 nm) excitation. The decay kinetics of CaWO4 single crystal shows double-exponential decay with fast decay constant τ1 = 5.4 μs and slow decay constant τ2 = 177.1 μs. The energy resolution of CaWO4 crystal was found to be 31.6% in the net peak of 545.9 channel. Meanwhile, the absolute output is at the lever of 19,000 ± 1000 photons/MeV. The results indicate the scintillator of CaWO4 single crystal has great potential in the applications of high-energy physics and nuclear physics due to its high light output and great energy resolution.

  16. The Crystal Hotel: A Microfluidic Approach to Biomimetic Crystallization.

    Science.gov (United States)

    Gong, Xiuqing; Wang, Yun-Wei; Ihli, Johannes; Kim, Yi-Yeoun; Li, Shunbo; Walshaw, Richard; Chen, Li; Meldrum, Fiona C

    2015-12-02

    A "crystal hotel" microfluidic device that allows crystal growth in confined volumes to be studied in situ is used to produce large calcite single crystals with predefined crystallographic orientation, microstructure, and shape by control of the detailed physical environment, flow, and surface chemistry. This general approach can be extended to form technologically important, nanopatterned single crystals. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Noise distribution of a peak track and hold circuit

    Science.gov (United States)

    Seller, Paul; Hardie, Alec L.; Morrissey, Quentin

    2012-12-01

    Noise in linear electronic circuits is well characterised in terms of power spectral density in the frequency domain and the Normal probability density function in the time domain. For instance a charge preamplifier followed by a simple time independent pulse shaping circuit produces an output with a predictable, easily calculated Normal density function. By the Ergodic Principle this is true if the signal is sampled randomly in time or the experiment is run many times and measured at a fixed time after the circuit is released from reset. Apart from well defined cases, the time of the sample after release of reset does not affect the density function. If this signal is then passed through a peak track-and-hold circuit the situation is very different. The probability density function of the sampled signal is no longer Normal and the function changes with the time of the sample after release of reset. This density function can be classified by the Gumbel probability density function which characterises the Extreme Value Distribution of a defined number of Normally distributed values. The number of peaks in the signal is an important factor in the analysis. This issue is analysed theoretically and compared with a time domain noise simulation programme. This is then related to a real electronic circuit used for low-noise X-ray measurements and shows how the low-energy resolution of this system is significantly degraded when using a peak track-and-hold.

  18. R-peaks detection based on stationary wavelet transform.

    Science.gov (United States)

    Merah, M; Abdelmalik, T A; Larbi, B H

    2015-10-01

    Automatic detection of the QRS complexes/R-peaks in an electrocardiogram (ECG) signal is the most important step preceding any kind of ECG processing and analysis. The performance of these systems heavily relies on the accuracy of the QRS detector. The objective of present work is to drive a new robust method based on stationary wavelet transform (SWT) for R-peaks detection. The decimation of the coefficients at each level of the transformation algorithm is omitted, more samples in the coefficient sequences are available and hence a better outlier detection can be performed. Using the information of local maxima, minima and zero crossings of the fourth SWT coefficient detail, the proposed algorithm identifies the significant points for detection and delineation of the QRS complexes, as well as detection and identification of the QRS individual waves peaks of the pre-processed ECG signal. Various experimental results show that the proposed algorithm exhibits reliable QRS detection as well as accurate ECG delineation, achieving excellent performance on different databases, on the MIT-BIH database (Se=99.84%, P=99.88%), on the QT Database (Se=99.94%, P=99.89%) and on MIT-BIH Noise Stress Test Database, (Se=95.30%, P=93.98%). Reliability and accuracy are close to the highest among the ones obtained in other studies. Experiments results being satisfactory, the SWT may represent a novel QRS detection tool, for a robust ECG signal analysis. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  19. Remote Sensing and Modeling of Cyclone Monica near Peak Intensity

    Directory of Open Access Journals (Sweden)

    Stephen L. Durden

    2010-07-01

    Full Text Available Cyclone Monica was an intense Southern Hemisphere tropical cyclone of 2006. Although no in situ measurements of Monica’s inner core were made, microwave, infrared, and visible satellite instruments observed Monica before and during peak intensity through landfall on Australia’s northern coast. The author analyzes remote sensing measurements in detail to investigate Monica’s intensity. While Dvorak analysis of its imagery argues that it was of extreme intensity, infrared and microwave soundings indicate a somewhat lower intensity, especially as it neared landfall. The author also describes several numerical model runs that were made to investigate the maximum possible intensity for the observed environmental conditions; these simulations also suggest a lower intensity than estimates from Dvorak analysis alone. Based on the evidence from the various measurements and modeling, the estimated range for the minimum sea level pressure at peak intensity is 900 to 920 hPa. The estimated range for the one-minute averaged maximum wind speed at peak intensity is 72 to 82 m/s. These maxima were likely reached about 24 hours prior to landfall, with some weakening occurring afterward.

  20. Martial arts striking hand peak acceleration, accuracy and consistency.

    Science.gov (United States)

    Neto, Osmar Pinto; Marzullo, Ana Carolina De Miranda; Bolander, Richard P; Bir, Cynthia A

    2013-01-01

    The goal of this paper was to investigate the possible trade-off between peak hand acceleration and accuracy and consistency of hand strikes performed by martial artists of different training experiences. Ten male martial artists with training experience ranging from one to nine years volunteered to participate in the experiment. Each participant performed 12 maximum effort goal-directed strikes. Hand acceleration during the strikes was obtained using a tri-axial accelerometer block. A pressure sensor matrix was used to determine the accuracy and consistency of the strikes. Accuracy was estimated by the radial distance between the centroid of each subject's 12 strikes and the target, whereas consistency was estimated by the square root of the 12 strikes mean squared distance from their centroid. We found that training experience was significantly correlated to hand peak acceleration prior to impact (r(2)=0.456, p =0.032) and accuracy (r(2)=0. 621, p=0.012). These correlations suggest that more experienced participants exhibited higher hand peak accelerations and at the same time were more accurate. Training experience, however, was not correlated to consistency (r(2)=0.085, p=0.413). Overall, our results suggest that martial arts training may lead practitioners to achieve higher striking hand accelerations with better accuracy and no change in striking consistency.

  1. Peak reduction for commercial buildings using energy storage

    Science.gov (United States)

    Chua, K. H.; Lim, Y. S.; Morris, S.

    2017-11-01

    Battery-based energy storage has emerged as a cost-effective solution for peak reduction due to the decrement of battery’s price. In this study, a battery-based energy storage system is developed and implemented to achieve an optimal peak reduction for commercial customers with the limited energy capacity of the energy storage. The energy storage system is formed by three bi-directional power converter rated at 5 kVA and a battery bank with capacity of 64 kWh. Three control algorithms, namely fixed-threshold, adaptive-threshold, and fuzzy-based control algorithms have been developed and implemented into the energy storage system in a campus building. The control algorithms are evaluated and compared under different load conditions. The overall experimental results show that the fuzzy-based controller is the most effective algorithm among the three controllers in peak reduction. The fuzzy-based control algorithm is capable of incorporating a priori qualitative knowledge and expertise about the load characteristic of the buildings as well as the useable energy without over-discharging the batteries.

  2. A new record peak luminosity for the LHC

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    Two weeks of dedicated machine development paid off last weekend when the LHC ran for physics with three nominal intensity (∼1011 protons) bunches in each beam.   This brought a new record peak luminosity of around 8×1029 cm-2 s-1, and allowed the LHC to double the integrated luminosity delivered to the experiments since 30 March from 16 to 32 inverse nanobarns over the weekend. After a few more fills in this configuration, the number of bunches will be raised to six per beam, which will in turn allow the peak luminosity to break the 1030 cm-2 s-1 barrier for the first time, well on the way to achieving the 2010 objective of 1032 cm-2 s-1. This peak luminosity goal requires 800 nominal bunches per beam squeezed to a beta of 3.5 metres. The plan for 2011 is to run the LHC in this configuration over about 10 months, thus achieving the objective of recording one inverse femtobarn of data in total. The machine development period also allowed the TOTEM detectors to be set up with 45...

  3. A New Peak of Leonids observed by Radio Technics

    Science.gov (United States)

    Suzuki, K.; Maegawa, K.; Minagawa, Y.

    Radio meteor observations with amateur ham radio wave have been carried out in Japan since August, 1996, by using forward-scattered meteor echoes of VHF radio waves (53.75MHz, 50W, CW) transmitted in Sabae, Fukui prefecture. A strong activity of Leonids was observed between 22h and 01h on November 16/17 (UT), 1996. The hourly rate of long duration echoes reached over 50 times larger than in non-shower period and 1.2 to 1.5 times larger than that at the normal maximum of Leonids, respectively. This enhanced activity occurred at a solar longitude (SL) of 234.95 plus or minus 0.05 degrees (2000.0 eq.), and is probably different from normal peak of Leonids at 235.45 plus or minus 0.05 degrees(2000.0 eq.) observed in 1990's. A corresponding peak in 1995 was also reported by visual meteor observation by many observers in Japan. The ascending node of Comet Tempel-Tuttle in 1966 was at 235.11 degrees in SL, and is closer to the new peak than the normal one (at 235.45 degrees in SL).

  4. Mineral resources: Reserves, peak production and the future

    Science.gov (United States)

    Meinert, Lawrence D.; Robinson, Gilpin; Nassar, Nedal

    2016-01-01

    The adequacy of mineral resources in light of population growth and rising standards of living has been a concern since the time of Malthus (1798), but many studies erroneously forecast impending peak production or exhaustion because they confuse reserves with “all there is”. Reserves are formally defined as a subset of resources, and even current and potential resources are only a small subset of “all there is”. Peak production or exhaustion cannot be modeled accurately from reserves. Using copper as an example, identified resources are twice as large as the amount projected to be needed through 2050. Estimates of yet-to-be discovered copper resources are up to 40-times more than currently-identified resources, amounts that could last for many centuries. Thus, forecasts of imminent peak production due to resource exhaustion in the next 20–30 years are not valid. Short-term supply problems may arise, however, and supply-chain disruptions are possible at any time due to natural disasters (earthquakes, tsunamis, hurricanes) or political complications. Needed to resolve these problems are education and exploration technology development, access to prospective terrain, better recycling and better accounting of externalities associated with production (pollution, loss of ecosystem services and water and energy use).

  5. High peak power diode stacks for high energy lasers

    Science.gov (United States)

    Negoita, Viorel C.; Vethake, Thilo; Jiang, John; Roff, Robert; Shih, Ming; Duck, Richard; Bauer, Marc; Mite, Roberto; Boucke, Konstantin; Treusch, Georg

    2015-02-01

    High energy solid state lasers are being developed for fusion experiments and other research applications where high energy per pulse is required but the repetition rate is rather low, around 10Hz. We report our results on high peak power diode laser stacks used as optical pumps for these lasers. The stacks are based on 10 mm bars with 4 mm cavity length and 55% fill factor, with peak power exceeding 500 W per bar. These bars are stacked and mounted on a cooler which provides backside cooling and electrical insulation. Currently we mount 25 bars per cooler for a nominal peak power of 12.5 kW, but in principle the mounting scheme can be scaled to a different number of devices depending on the application. Pretesting of these bars before soldering on the cooler enables us to select devices with similar wavelength and thus we maintain tight control of the spectral width (FWHM less than 6 nm). Fine adjustments of the centroid wavelength can be done by means of temperature of the cooling fluid or bias current. The available wavelength range spans from 880 nm to 1000 nm, and the wavelength of the entire assembly of stacks can be controlled to within 0.5 nm of the target value, which makes these stacks suitable for pumping a variety of gain media. The devices are fast axis collimated, with over 95% power being collimated in 6 mrad (full angle). The slow axis divergence is 9° (full angle) for 95% power content.

  6. The bias of weighted dark matter halos from peak theory

    CERN Document Server

    Verde, Licia; Simpson, Fergus; Alvarez-Gaume, Luis; Heavens, Alan; Matarrese, Sabino

    2014-01-01

    We give an analytical form for the weighted correlation function of peaks in a Gaussian random field. In a cosmological context, this approach strictly describes the formation bias and is the main result here. Nevertheless, we show its validity and applicability to the evolved cosmological density field and halo field, using Gaussian random field realisations and dark matter N-body numerical simulations. Using this result from peak theory we compute the bias of peaks (and dark matter halos) and show that it reproduces results from the simulations at the ${\\mathcal O}(10\\%)$ level. Our analytical formula for the bias predicts a scale-dependent bias with two characteristics: a broad band shape which, however, is most affected by the choice of weighting scheme and evolution bias, and a more robust, narrow feature localised at the BAO scale, an effect that is confirmed in simulations. This scale-dependent bias smooths the BAO feature but, conveniently, does not move it. We provide a simple analytic formula to des...

  7. Simple area determination of strongly overlapping ion mobility peaks.

    Science.gov (United States)

    Borovcová, Lucie; Hermannová, Martina; Pauk, Volodymyr; Šimek, Matěj; Havlíček, Vladimír; Lemr, Karel

    2017-08-15

    Coupling of ion mobility with mass spectrometry has brought new frontiers in separation and quantitation of a wide range of isobaric/isomeric compounds. Ion mobility spectrometry may separate ions possessing the identical molecular formula but having different molecular shapes. The separation space in most commercially available instruments is limited and rarely the mobility resolving power exceeds one hundred. From this perspective, new approaches allowing for extracting individual compound signals out of a more complex mixture are needed. In this work we present a new simple analytical approach based on fitting of arrival time distribution (ATD) profiles by Gaussian functions and generating of ATD functions. These ATD functions well describe even distorted ion mobility peaks of individual compounds and allow for extracting their peaks from mobilograms of mixtures. Contrary to classical integration, our approach works well with irregular overlapping peaks. Using mobilograms of standards to generate ATD functions, poorly separated compounds, e.g. isomers, with identical mass spectra representing a hard to solve task for various chemometric methods can be easily distinguished by our procedure. Alternatively ATD functions can be obtained from ATD profiles of ions unique to individual mixture components (if such ions exist) and mobilograms of standards are not required. On a set of hyaluronan-derived oligosaccharides we demonstrated excellent ATD repeatability enabling the resolution of binary mixtures, including mixtures with minor component level about 5%. Ion mobility quantitative data of isomers were confirmed by high performance liquid chromatography. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Mineral Resources: Reserves, Peak Production and the Future

    Directory of Open Access Journals (Sweden)

    Lawrence D. Meinert

    2016-02-01

    Full Text Available The adequacy of mineral resources in light of population growth and rising standards of living has been a concern since the time of Malthus (1798, but many studies erroneously forecast impending peak production or exhaustion because they confuse reserves with “all there is”. Reserves are formally defined as a subset of resources, and even current and potential resources are only a small subset of “all there is”. Peak production or exhaustion cannot be modeled accurately from reserves. Using copper as an example, identified resources are twice as large as the amount projected to be needed through 2050. Estimates of yet-to-be discovered copper resources are up to 40-times more than currently-identified resources, amounts that could last for many centuries. Thus, forecasts of imminent peak production due to resource exhaustion in the next 20–30 years are not valid. Short-term supply problems may arise, however, and supply-chain disruptions are possible at any time due to natural disasters (earthquakes, tsunamis, hurricanes or political complications. Needed to resolve these problems are education and exploration technology development, access to prospective terrain, better recycling and better accounting of externalities associated with production (pollution, loss of ecosystem services and water and energy use.

  9. The specific heat of YBCO single crystals near Tc

    Energy Technology Data Exchange (ETDEWEB)

    Reagan, S.; Lawrie, I.D.; Howson, M.A. [Leeds Univ. (United Kingdom)

    1992-12-01

    The authors present results for the measured specific heat of YBCO single crystals between 80 and 110K. The specific heat has been measured using an a.c. optical heating technique with a temperature resolution of 15mK. The superconducting transition is marked by a sharply peaked {open_quote}Lambda{close_quote} like anomaly. The {open_quote}fluctuation{close_quote} contributions to the specific heat fit a logarithmic divergence very well.

  10. Peak effect studies in single crystals CeRu 2 and 2H-NbS 2

    Indian Academy of Sciences (India)

    A A Tulapurkar1 A K Grover1 S Ramakrishnan1 A Niazi1 2 A K Rastogi3. Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400 005, India; School of Physical Sciences, Jamia Millia Islamia University, New Delhi, India; School of Physical Sciences, Jawaharlal Nehru University, Delhi 110 067, India ...

  11. Crystal growth, defects, and mechanical and spectral properties of a novel mixed laser crystal Nd:GdYNbO{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Shoujun; Dou, Renqin [Chinese Academy of Sciences, Anhui Institute of Optics and Fine Mechanics, Hefei, Anhui Province (China); University of Science and Technology of China, Hefei (China); Liu, Wenpeng; Zhang, Qingli; Peng, Fang; Luo, Jianqiao; Sun, Guihua; Sun, Dunlu [Chinese Academy of Sciences, Anhui Institute of Optics and Fine Mechanics, Hefei, Anhui Province (China)

    2017-01-15

    A mixed laser crystal of Nd-doped GYNO crystal was grown successfully by Czochralski method. The crystal belongs to monoclinic system with space group I2/a, the structural parameters are obtained by the X-ray Rietveld refinement method. The defects and dislocations along three crystallographic orientations were studied by using the chemical etching method with the phosphoric acid etchant. The mechanical properties (including hardness, yield strength, fracture toughness, and brittle index) of the crystal were estimated by Vickers hardness test. The transmission spectrum was measured at room temperature, and the absorption peaks were assigned. Spectral properties of the as-grown crystal were investigated by Judd-Ofelt theory, and the Judd-Ofelt intense parameters Ω{sub 2,4,6} were obtained to be 9.674 x 10{sup -20}, 2.092 x 10{sup -20}, and 4.061 x 10{sup -20} cm{sup 2}, respectively. (orig.)

  12. Analysis of rocking curve measurements of LiF flight crystals for the objective crystal spectrometer on SPECTRUM-X-GAMMA

    DEFF Research Database (Denmark)

    Halm, I.; Wiebicke, H.-J.; Geppert, U.R.M.E.

    1993-01-01

    ) crystals of dimensions approximately 23 × 63 mm2 are required to cover one side of a large (1000 × 600 mm2) panel, which is to be mounted in front of one of two high throughput X- ray telescopes. Rocking curves of 441 LiF(220) crystals measured by using an expanded Cu - Kα2 beam were analyzed to select...... the best ones for the flight model. An important parameter is the non-parallelity of the crystal lattice planes with respect to the rear side of the crystals, since it is of the same order of magnitude as the rocking curve width. By lapping the rear side to diminish the non-parallelity and selection...... the main parameters of the rocking curve averaged over all crystals can be improved at least by a factor of 1.6 both in full width half maximum and peak reflectivity....

  13. Magnetically Directed Two-Dimensional Crystallization of OmpF Membrane Proteins in Block Copolymers.

    Science.gov (United States)

    Klara, Steven S; Saboe, Patrick O; Sines, Ian T; Babaei, Mahnoush; Chiu, Po-Lin; DeZorzi, Rita; Dayal, Kaushik; Walz, Thomas; Kumar, Manish; Mauter, Meagan S

    2016-01-13

    Two-dimensional (2D) alignment and crystallization of membrane proteins (MPs) is increasingly important in characterizing their three-dimensional (3D) structure, in designing pharmacological agents, and in leveraging MPs for biomimetic devices. Large, highly ordered MP 2D crystals in block copolymer (BCP) matrices are challenging to fabricate, but a facile and scalable technique for aligning and crystallizing MPs in thin-film geometries would rapidly translate into applications. This work introduces a novel method to grow larger and potentially better ordered 2D crystals by performing the crystallization process in the presence of a strong magnetic field. We demonstrate the efficacy of this approach using a β-barrel MP, outer membrane protein F (OmpF), in short-chain polybutadiene-poly(ethylene oxide) (PB-PEO) membranes. Crystals grown in a magnetic field were up to 5 times larger than conventionally grown crystals, and a signal-to-noise (SNR) analysis of diffraction peaks in Fourier transforms of specimens imaged by negative-stain electron microscopy (EM) and cryo-EM showed twice as many high-SNR diffraction peaks, indicating that the magnetic field also improves crystal order.

  14. Computer-assisted Crystallization.

    Science.gov (United States)

    Semeister, Joseph J., Jr.; Dowden, Edward

    1989-01-01

    To avoid a tedious task for recording temperature, a computer was used for calculating the heat of crystallization for the compound sodium thiosulfate. Described are the computer-interfacing procedures. Provides pictures of laboratory equipment and typical graphs from experiments. (YP)

  15. Photonic crystals and metamaterials

    Science.gov (United States)

    Lourtioz, Jean-Michel

    2008-01-01

    Recent results obtained on semiconductor-based photonic crystal devices are of great promise for future developments of photonic crystals and their applications to 'all-photonic' integrated circuits. Device performance mostly relies on the strong confinement of light thanks to photonic bandgap effects, but photonic crystals also exhibit remarkable dispersion properties in their transmission bands, thus opening the perspective of new optical functionalities. Slow light, supercollimation, superprism, and negative refraction effects are among the fascinating phenomena which strongly motivate the community. Studies in these directions parallel those on metamaterials, which are expected to provide a simultaneous control of the dielectric permittivity and of the magnetic permeability. In this article, we briefly review some important advances on photonic crystals and metamaterials, as these two topics received a particular attention during the "Nanosciences et Radioélectricité" workshop organized by CNFRS in Paris on the 20th and 21st of March 2007. To cite this article: J.-M. Lourtioz, C. R. Physique 9 (2008).

  16. Climate change and peak demand for electricity: Evaluating policies for reducing peak demand under different climate change scenarios

    Science.gov (United States)

    Anthony, Abigail Walker

    This research focuses on the relative advantages and disadvantages of using price-based and quantity-based controls for electricity markets. It also presents a detailed analysis of one specific approach to quantity based controls: the SmartAC program implemented in Stockton, California. Finally, the research forecasts electricity demand under various climate scenarios, and estimates potential cost savings that could result from a direct quantity control program over the next 50 years in each scenario. The traditional approach to dealing with the problem of peak demand for electricity is to invest in a large stock of excess capital that is rarely used, thereby greatly increasing production costs. Because this approach has proved so expensive, there has been a focus on identifying alternative approaches for dealing with peak demand problems. This research focuses on two approaches: price based approaches, such as real time pricing, and quantity based approaches, whereby the utility directly controls at least some elements of electricity used by consumers. This research suggests that well-designed policies for reducing peak demand might include both price and quantity controls. In theory, sufficiently high peak prices occurring during periods of peak demand and/or low supply can cause the quantity of electricity demanded to decline until demand is in balance with system capacity, potentially reducing the total amount of generation capacity needed to meet demand and helping meet electricity demand at the lowest cost. However, consumers need to be well informed about real-time prices for the pricing strategy to work as well as theory suggests. While this might be an appropriate assumption for large industrial and commercial users who have potentially large economic incentives, there is not yet enough research on whether households will fully understand and respond to real-time prices. Thus, while real-time pricing can be an effective tool for addressing the peak load

  17. Automated Critical Peak Pricing Field Tests: Program Descriptionand Results

    Energy Technology Data Exchange (ETDEWEB)

    Piette, Mary Ann; Watson, David; Motegi, Naoya; Kiliccote, Sila; Xu, Peng

    2006-04-06

    California utilities have been exploring the use of critical peak prices (CPP) to help reduce needle peaks in customer end-use loads. CPP is a form of price-responsive demand response (DR). Recent experience has shown that customers have limited knowledge of how to operate their facilities in order to reduce their electricity costs under CPP (Quantum 2004). While the lack of knowledge about how to develop and implement DR control strategies is a barrier to participation in DR programs like CPP, another barrier is the lack of automation of DR systems. During 2003 and 2004, the PIER Demand Response Research Center (DRRC) conducted a series of tests of fully automated electric demand response (Auto-DR) at 18 facilities. Overall, the average of the site-specific average coincident demand reductions was 8% from a variety of building types and facilities. Many electricity customers have suggested that automation will help them institutionalize their electric demand savings and improve their overall response and DR repeatability. This report focuses on and discusses the specific results of the Automated Critical Peak Pricing (Auto-CPP, a specific type of Auto-DR) tests that took place during 2005, which build on the automated demand response (Auto-DR) research conducted through PIER and the DRRC in 2003 and 2004. The long-term goal of this project is to understand the technical opportunities of automating demand response and to remove technical and market impediments to large-scale implementation of automated demand response (Auto-DR) in buildings and industry. A second goal of this research is to understand and identify best practices for DR strategies and opportunities. The specific objectives of the Automated Critical Peak Pricing test were as follows: (1) Demonstrate how an automated notification system for critical peak pricing can be used in large commercial facilities for demand response (DR). (2) Evaluate effectiveness of such a system. (3) Determine how customers

  18. Strength anomaly in B2 FeAl single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Yoshimi, K.; Hanada, S.; Yoo, M.H. [Oak Ridge National Lab., TN (United States); Matsumoto, N. [Tohoku Univ. (Japan). Graduate School

    1994-12-31

    Strength and deformation microstructure of B2 Fe-39 and 48%Al single crystals (composition given in atomic percent), which were fully annealed to remove frozen-in vacancies, have been investigated at temperatures between room temperature and 1073K. The hardness of as-homogenized Fe-48Al is higher than that of as-homogenized Fe-39Al while after additional annealing at 698K the hardness of Fe-48Al becomes lower than that of Fe-39Al. Fe-39Al single crystals slowly cooled after homogenizing at a high temperature were deformed in compression as a function of temperature and crystal orientation. A peak of yield strength appears around 0.5T{sub m} (T{sub m} = melting temperature). The orientation dependence of the critical resolved shear stress does not obey Schmid`s law even at room temperature and is quite different from that of b.c.c. metals and B2 intermetallics at low temperatures. At the peak temperature slip transition from <111>-type to <001>-type is found to occur macroscopically and microscopically, while it is observed in TEM that some of the [111] dislocations decompose into [101] and [010] on the (1096I) plane below the peak temperature. The physical sources for the positive temperature dependence of yield stress of B2 FeAl are discussed based on the obtained results.

  19. Crystal growth, physical properties and computational insights of semi-organic non-linear optical crystal diphenylguanidinium perchlorate grown by conventional solvent evaporation method

    Science.gov (United States)

    Kajamuhideen, M. S.; Sethuraman, K.; Ramamurthi, K.; Ramasamy, P.

    2018-02-01

    A splendid nonlinear optical single crystals diphenylguanidinium perchlorate (DPGP) was lucratively grown by low cost solvent evaporation method with the dimensions of 8 × 4 × 2 mm3. Structural and morphological studies of grown crystal were confirmed using X-ray diffraction studies. The presence of diverse functional groups was identified using FTIR and RAMAN studies. The molecular structure of a grown crystal was inveterate by NMR studies. The optical transmittance of DPGP crystal was analyzed using UV-vis-NIR studies. Photoluminescence spectrum shows sharp, well defined emission peak at 388 nm. Thermal studies assign that adduct is stable with the melting point of 164 °C. Microhardness studies declare that DPGP crystal belongs to the soft material class and their yield strength and elastic stiffness constant values were evaluated. Photoconductivity studies revealed the negative photoconductive nature of DPGP crystal. Second harmonic generation (SHG) efficiency of the DPGP crystal was 1.4 times that of potassium dihydrogen phosphate. Etching studies were carried out for different etching time. The dielectric studies were performed at different frequency. Laser damage threshold properties of DPGP crystal were examined using Nd:YAG laser system. The HOMO-LUMO energy gap evident the charge transfer interaction of the molecule. The calculated first order hyperpolarizability value is 5 times greater than that of urea. Thus, the grown DPGP single crystals are well suited for NLO device fabrications.

  20. Supercontinuum generation in fibers infiltrated with liquid crystals

    DEFF Research Database (Denmark)

    Rasmussen, Per Dalgaard; Bang, Ole; Lægsgaard, Jesper

    2006-01-01

    Supercontinuum generation in a capillary tube infiltrated with a nematic liquid crystal is investigated theoretically in the near infrared region. A liquid crystal with a high electronic nonlinearity is chosen, which makes it possible to generate 100 nm wide supercontinua using IO ps pulses...... with peak power 1.5 kW in a 10 cm long waveguide. The possibility of tuning the spectrum of the generated Supercontinuum by changing the dispersion of the waveguide is also considered. It is found that the broadening of the spectrum in both the normal and anomalous regime is mainly due to self phase...... modulation, and therefore the dispersion of the waveguide is only of minor importance. The tuning of the dispersion is achieved by varying the temperature of the liquid crystal inside the capillary...

  1. [Obtaining ribosome crystals in homogenates].

    Science.gov (United States)

    Bersani, F; Longo, I; Fanti, M; Pettazzoni, P

    1979-08-30

    Chick embryos are homogenized in order to analyse ribosome crystallization. Ribosome crystallization has been induced by hypothermic treatment in chick embryos homogenate. Tetramers and crystals were produced by gradually inducing the temperature over a span of 10 h to 4 degrees C. It has been observed that the concentration of KCl in the buffer is a critical point. It is suggested that the nuclear fraction is engaged in ribosome crystallization.

  2. Intensified crystallization in complex media: heuristics for crystallization of platform chemicals

    NARCIS (Netherlands)

    Urbanus, J.; Roelands, C.P.M.; Verdoes, D.; Horst, J.H. ter

    2012-01-01

    This paper presents heuristics for the integration of fermentation with the appropriate crystallization based in-situ product recovery (ISPR) technique. Here techniques, such as co-crystallization (CC), evaporative crystallization (EC), template induced crystallization (TIC), cooling crystallization

  3. Angle-resolved x-ray imaging using a resolution-tunable double-crystal analyser

    CERN Document Server

    Hirano, K

    2003-01-01

    A resolution-tunable double-crystal analyser was successfully applied, for the first time, to angle-resolved x-ray imaging. Tuning the resolution between 0.5'' and 2.3'' was done with small loss of peak intensity using a Si(220) double-crystal analyser. The angle-resolved images of a housefly were recorded on nuclear emulsion plates at various angular resolutions. Several methods to improve the angular resolution of the analyser are also proposed.

  4. Crystal Structure Prediction could have helped the Experimentalists with Polymorphism in Benzamide!

    OpenAIRE

    2008-01-01

    Abstract Benzamide was the first molecular material for which polymorphism was reported as long as 176 years ago. Unfortunately, due to very similar cell metrics leading to massive peak overlap, the metastable form reported by Liebig escaped structural characterization by XRD until recently. With the help of crystal structure prediction this old riddle of ?Liebig's? polymorph of benzamide could have been solved many years earlier. Performing state of the art crystal structure predi...

  5. Crystallization of Electrodeposited Germanium Thin Film on Silicon (100).

    Science.gov (United States)

    Abidin, Mastura Shafinaz Zainal; Matsumura, Ryo; Anisuzzaman, Mohammad; Park, Jong-Hyeok; Muta, Shunpei; Mahmood, Mohamad Rusop; Sadoh, Taizoh; Hashim, Abdul Manaf

    2013-11-06

    We report the crystallization of electrodeposited germanium (Ge) thin films on n-silicon (Si) (100) by rapid melting process. The electrodeposition was carried out in germanium (IV) chloride: propylene glycol (GeCl₄:C₃H₈O₂) electrolyte with constant current of 50 mA for 30 min. The measured Raman spectra and electron backscattering diffraction (EBSD) images show that the as-deposited Ge thin film was amorphous. The crystallization of deposited Ge was achieved by rapid thermal annealing (RTA) at 980 °C for 1 s. The EBSD images confirm that the orientations of the annealed Ge are similar to that of the Si substrate. The highly intense peak of Raman spectra at 300 cm-1 corresponding to Ge-Ge vibration mode was observed, indicating good crystal quality of Ge. An additional sub peak near to 390 cm-1 corresponding to the Si-Ge vibration mode was also observed, indicating the Ge-Si mixing at Ge/Si interface. Auger electron spectroscopy (AES) reveals that the intermixing depth was around 60 nm. The calculated Si fraction from Raman spectra was found to be in good agreement with the value estimated from Ge-Si equilibrium phase diagram. The proposed technique is expected to be an effective way to crystallize Ge films for various device applications as well as to create strain at the Ge-Si interface for enhancement of mobility.

  6. Crystallization of Electrodeposited Germanium Thin Film on Silicon (100

    Directory of Open Access Journals (Sweden)

    Abdul Manaf Hashim

    2013-11-01

    Full Text Available We report the crystallization of electrodeposited germanium (Ge thin films on n-silicon (Si (100 by rapid melting process. The electrodeposition was carried out in germanium (IV chloride: propylene glycol (GeCl4:C3H8O2 electrolyte with constant current of 50 mA for 30 min. The measured Raman spectra and electron backscattering diffraction (EBSD images show that the as-deposited Ge thin film was amorphous. The crystallization of deposited Ge was achieved by rapid thermal annealing (RTA at 980 °C for 1 s. The EBSD images confirm that the orientations of the annealed Ge are similar to that of the Si substrate. The highly intense peak of Raman spectra at 300 cm−1 corresponding to Ge-Ge vibration mode was observed, indicating good crystal quality of Ge. An additional sub peak near to 390 cm−1 corresponding to the Si-Ge vibration mode was also observed, indicating the Ge-Si mixing at Ge/Si interface. Auger electron spectroscopy (AES reveals that the intermixing depth was around 60 nm. The calculated Si fraction from Raman spectra was found to be in good agreement with the value estimated from Ge-Si equilibrium phase diagram. The proposed technique is expected to be an effective way to crystallize Ge films for various device applications as well as to create strain at the Ge-Si interface for enhancement of mobility.

  7. Kinetic Study on the Isothermal and Nonisothermal Crystallization of Monoglyceride Organogels

    Science.gov (United States)

    Meng, Zong; Yang, Lijun; Geng, Wenxin; Yao, Yubo; Wang, Xingguo; Liu, Yuanfa

    2014-01-01

    The isothermal and nonisothermal crystallization kinetics of monoglyceride (MAG) organogels were studied by pulsed nuclear magnetic resonance (pNMR) and differential scanning calorimetry (DSC), respectively. The Avrami equation was used to describe the isothermal crystallization kinetics and experimental data fitted the equation fairly well. Results showed that the crystal growth of MAG organogels was a rod-like growth of instantaneous nuclei at higher degrees of supercooling and a plate-like form with high nucleation rate at lower degrees of supercooling. The exothermic peak in nonisothermal DSC curves for the MAG organogels became wider and shifted to lower temperature when the cooling rate increased, and nonisothermal crystallization was analyzed by Mo equation. Results indicated that at the same crystallization time, to get a higher degree of relative crystallinity, a higher cooling rate was necessary. The activation energy of nonisothermal crystallization was calculated as 739.59 kJ/mol according to the Kissinger method. Therefore, as the results of the isothermal and nonisothermal crystallization kinetics for the MAG organogels obtained, the crystallization rate, crystal nucleation, and growth during the crystallization process could be preliminarily monitored through temperature and cooling rate regulation, which laid the foundation for the real industrial manufacture and application of the MAG organogels. PMID:24701138

  8. Crystallization kinetics of amorphous griseofulvin by pattern fitting procedure using X-ray diffraction data.

    Science.gov (United States)

    Yamamura, Shigeo; Takahira, Rieko; Momose, Yasunori

    2007-05-01

    A pattern fitting procedure using X-ray powder diffraction patterns was applied to study the crystallization kinetics of amorphous griseofulvin. From the optimized parameters obtained by pattern fitting, a change in the quantity and quality of griseofulvin crystals with crystallization was also investigated. Amorphous griseofulvin was prepared by cooling the melts followed by pulverization. X-ray diffraction patterns of amorphous griseofulvin were repeatedly measured every 20 h. The observed pattern was separated into crystalline diffraction intensity and amorphous scattering intensity by the nonlinear least-squares procedure. The fitting between the observed and simulated diffraction patterns was satisfactorily independent of the degree of crystallinity. Since a good linear relationship was found in a plot of amorphous scattering intensity against crystalline diffraction intensity, the degree of crystallinity can be determined according to Hermans' method. The diffraction peak width increased with higher diffraction angles with crystallization. The crystallization was biphasic: fast and slow crystallization with the growth of low disordered crystals and disordered crystals, respectively. The pattern fitting procedure is a powerful tool to analyze the X-ray diffraction patterns of semicrystalline materials. This procedure can simultaneously analyze the degree of crystallinity and crystal disorder in semicrystalline samples during crystallization.

  9. Kinetic Study on the Isothermal and Nonisothermal Crystallization of Monoglyceride Organogels

    Directory of Open Access Journals (Sweden)

    Zong Meng

    2014-01-01

    Full Text Available The isothermal and nonisothermal crystallization kinetics of monoglyceride (MAG organogels were studied by pulsed nuclear magnetic resonance (pNMR and differential scanning calorimetry (DSC, respectively. The Avrami equation was used to describe the isothermal crystallization kinetics and experimental data fitted the equation fairly well. Results showed that the crystal growth of MAG organogels was a rod-like growth of instantaneous nuclei at higher degrees of supercooling and a plate-like form with high nucleation rate at lower degrees of supercooling. The exothermic peak in nonisothermal DSC curves for the MAG organogels became wider and shifted to lower temperature when the cooling rate increased, and nonisothermal crystallization was analyzed by Mo equation. Results indicated that at the same crystallization time, to get a higher degree of relative crystallinity, a higher cooling rate was necessary. The activation energy of nonisothermal crystallization was calculated as 739.59 kJ/mol according to the Kissinger method. Therefore, as the results of the isothermal and nonisothermal crystallization kinetics for the MAG organogels obtained, the crystallization rate, crystal nucleation, and growth during the crystallization process could be preliminarily monitored through temperature and cooling rate regulation, which laid the foundation for the real industrial manufacture and application of the MAG organogels.

  10. Small Business Innovations (Crystal Components)

    Science.gov (United States)

    1991-01-01

    Scientific Materials Corporation, Bozeman, MT developed the SciMax line of improved Nd:Yag crystals under an Small Business Innovation Research (SBIR) contract with Langley Research Center. They reduced the amount of water trapped in the crystals during growth to improve the optical quality and efficiency. Applications of the crystals include fiber optics, telecommunications, welding, drilling, eye surgery and medical instrumentation.

  11. Crystal engineering: A brief overview

    Indian Academy of Sciences (India)

    The possibility of designing a particular crystal packing is, however, of more recent origin and the subject of crystal engineering has addressed this possibility, more or less systematically, during the past 30 years. Crystal engineering demands a detailed and thorough knowledge of intermolecular interactions, which act as ...

  12. Optimization of photonic crystal cavities

    DEFF Research Database (Denmark)

    Wang, Fengwen; Sigmund, Ole

    2017-01-01

    We present optimization of photonic crystal cavities. The optimization problem is formulated to maximize the Purcell factor of a photonic crystal cavity. Both topology optimization and air-hole-based shape optimization are utilized for the design process. Numerical results demonstrate...... that the Purcell factor of the photonic crystal cavity can be significantly improved through optimization....

  13. Chiral Crystallization of Ethylenediamine Sulfate

    Science.gov (United States)

    Koby, Lawrence; Ningappa, Jyothi B.; Dakesssian, Maria; Cuccia, Louis A.

    2005-01-01

    The optimal conditions for the crystallization of achiral ethylenediamine sulfate into large chiral crystals that are ideal for polarimetry studies and observation using Polaroid sheets are presented. This experiment is an ideal undergraduate experiment, which clearly demonstrates the chiral crystallization of an achiral molecule.

  14. [Comparisons of spectral properties of CsI:T1 crystals with various Tl(+)-doped concentrations].

    Science.gov (United States)

    Wu, Zheng-Long

    2011-08-01

    Absorption Spectra and Photoluminescence (PL) spectra of CsI: T1 crystals with various T1+-concentrations were measured for absorption and luminescent research in CsI: T1. Their UV absorption spectra contained three peaks at 297, 273 and 247 nm. The experiments were demonstrated that the peaks in the high T(1+)-concentration CsI: T1 crystals are broader than ones in the low T(1+)-concentration crystals and their absorption A-peak shift by 20 nm, but their PL with UV excitations are similar. It was suggested that lattice distortions in the high T1+-concentration CsI: T1 lead to the changes in absorption or fluorescence excitation peaks, but no changes in the fluorescence band widths and locations at room temperature.

  15. Electrically tunable Fabry-Péerot resonator based on microstructured Si containing liquid crystal

    KAUST Repository

    Tolmachev, Vladimir A.

    2012-01-01

    We have built Fabry-Perot resonators based on microstructured silicon and a liquid crystal. The devices exhibit tuning of the resonance peaks over a wide range, with relative spectral shifts of up to Delta lambda/lambda = 10%. In order to achieve this substantial spectral shift, cavity peaks of high order were used. Under applied voltages of up to 15 V, a variation in the refractive index of the nematic liquid crystal E7 from Delta n(LC) = 0.12 to Delta n(LC) = 0.17 was observed. These results may have practical applications in the near-, mid and far-infrared range.

  16. Triple-crystal diffraction studies on ion-implanted and other silicon crystals using a synchrotron source

    Energy Technology Data Exchange (ETDEWEB)

    Stevenson, A.W.; Wilkins, S.W.; Harada, N.; Sakata, M.; Kashiwagura, N.; Ohshima, K.

    1988-11-01

    Triple-crystal diffraction studies are capable of cleanly separating the various experimental components of the scattering in the vicinity of a Bragg peak. The two-dimensional intensity distributions obtained in such an experiment consist of various components which extend in distinct directions in (..delta..theta/sub S/, ..delta..2THETA/sub S/) space, where ..delta..theta/sub S/ and ..delta..2THETA/sub S/ are the offset angles of the sample and analyzer/detector from the Bragg condition. One-dimensional 'slice' scans can be used in studying specific details, given a known disposition of the components, be they dynamical, kinematical or aspects of the instrumental arrangement. In this paper triple-crystal diffraction results obtained for given ion-implanted and other Si crystals using both a conventional X-ray tube and a synchrotron source are presented and compared.

  17. Cut-off nonlinearities in the low-temperature vibrations of glasses and crystals

    OpenAIRE

    Mizuno, Hideyuki; Silbert, Leonardo E.; Sperl, Matthias; Mossa, Stefano; Barrat, Jean-Louis

    2015-01-01

    We present a computer simulation study of glassy and crystalline states using the standard Lennard-Jones interaction potential that is truncated at a finite cut-off distance, as is typical of many computer simulations. We demonstrate that the discontinuity at the cut-off distance in the first derivative of the potential (corresponding to the interparticle force) leads to the appearance of cut-off nonlinearities. These cut-off nonlinearities persist into the very-low-temperature regime thereby...

  18. Class D spectral peak in Majorana quantum wires.

    Science.gov (United States)

    Bagrets, Dmitry; Altland, Alexander

    2012-11-30

    Proximity coupled spin-orbit quantum wires purportedly support midgap Majorana states at critical points. We show that, in the presence of disorder, these systems generate a second band center anomaly, which is of different physical origin but shares key characteristics with the Majorana state: it is narrow in width, insensitive to magnetic fields, carries unit spectral weight, and is rigidly tied to the band center. Depending on the parity of the number of subgap quasiparticle states, a Majorana mode does or does not coexist with the impurity peak. The strong "entanglement" between the two phenomena may hinder an unambiguous detection of the Majorana by spectroscopic techniques.

  19. Monolithic high peak-power coherent Doppler lidar system

    Science.gov (United States)

    Kotov, Leonid V.; Töws, Albert; Kurtz, Alfred; Bobkov, Konstantin K.; Aleshkina, Svetlana S.; Bubnov, Mikhail M.; Lipatov, Denis S.; Guryanov, Alexey N.; Likhachev, Mikhail

    2016-03-01

    In this work we present a monolithic lidar system, based on a newly-developed double-clad large mode area (LMA) polarization-maintaining Er-doped fiber and specially designed LMA passive components. Optimization of the fiber designs resulted in as high as 100 W of SBS limited peak power. The amplifier and its passive components (circulator and collimator) were integrated in an existing lidar system. The enhanced lidar system provides three times increase of scanning range compared to one based on standard telecom-grade amplifiers.

  20. Numerical simulation of meteorological conditions for peak pollution in Paris

    Energy Technology Data Exchange (ETDEWEB)

    Carissimo, B. [Electricite de France (EDF), 78 - Chatou (France). Direction des Etudes et Recherches

    1997-06-01

    Results obtained on the simulation of meteorological conditions during two episodes of peak pollution in Paris are presented, one in the winter, the other in the summer. The A3UR air quality modelling system is first described followed by the MERCURE mesoscale meteorological model. The conditions of simulation are described. The results obtained on these two causes show satisfactory agreement, for example on the magnitude of the urban heat island which is correctly reproduced. In this study, several areas of progress have been identified: improvement of the altitude measurement network around cities, the simulation of light wind conditions and the simulation of formation and dissipation of fog. (author) 24 refs.

  1. Estimate capital for operational risk using peak over threshold method

    Science.gov (United States)

    Saputri, Azizah Anugrahwati; Noviyanti, Lienda; Soleh, Achmad Zanbar

    2015-12-01

    Operational risk is inherent in bank activities. To cover this risk a bank reserves a fund called as capital. Often a bank uses Basic Indicator approach (BIA), Standardized Approach (SA), or Advanced Measurement Approach (AMA) for estimating the capital amount. BIA and SA are less-objective in comparison to AMA, since BIA and SA use non-actual loss data while AMA use the actual one. In this research, we define the capital as an OpVaR (i.e. the worst loss at a given confidence level) which will be estimated by Peak Over Threshold Method.

  2. Sleepwalking into a problem. Peak oil conference in Cork, Ireland

    Energy Technology Data Exchange (ETDEWEB)

    Koppelaar, R.

    2007-11-15

    At the sixth annual conference of the Association for the Study of Peak Oil and Gas (ASPO), which was held in Cork, Ireland, September 17-18, 2007, experts from all over the world gathered to discuss energy trends and the implications this has on the world's future. It appears that the world needs to develop policies for oil conservation and implement renewable energy strategies. The following two questions were discussed: (1) is the oil situation really that dire?; and (2) if so, how can the challenge of diminishing oil supply be met.

  3. Device level 3D characterization using PeakForce AFM

    Science.gov (United States)

    Timoney, Padraig; Zhang, Xiaoxiao; Vaid, Alok; Hand, Sean; Osborne, Jason; Milligan, Eric; Feinstein, Adam

    2016-03-01

    Traditional metrology solutions face a range of challenges at the 1X node such as three dimensional (3D) measurement capabilities, shrinking overlay and critical dimension (CD) error budgets driven by multi-patterning and via in trench CD measurements. With advent of advanced technology nodes and 3D processing, an increasing need is emerging for in-die metrology including across-structure and structure-to-structure characterization. A myriad of work has emerged in the past few years intending to address these challenges from various aspects; in-die OCD with reduced spot size and tilt beam on traditional critical dimension scanning electron microscopy (CDSEM) for height measurements. This paper explores the latest capability offered by PeakForceTM Tapping Atomic Force Microscopy (PFT-AFM). The use of traditional harmonic tapping mode for scanning high aspect ratio, and complex "3D" wafer structures, results in limited depth probing capability as well as excessive tip wear. These limitations arise due to the large tip-sample interaction volume in such confined spaces. PeakForce Tapping eliminates these limitations through direct real time control of the tip-sample interaction contact force. The ability of PeakForce to measure, and respond directly to tip- sample interaction forces results in more detailed feature resolution, reduced tip wear, and improved depth capability. In this work, the PFT-AFM tool was applied for multiple applications, including the 14nm fin and replacement metal gate (RMG) applications outlined below. Results from DOE wafers, detailed measurement precision studies and correlation to reference metrology are presented for validation of this methodology. With the fin application, precision of 0.3nm is demonstrated by measuring 5 dies with 10 consecutive runs. Capability to resolve within-die and localized within-macro height variation is also demonstrated. Results obtained from the fin measurements support the increasing trend that measurements

  4. Ultrafast, ultrahigh-peak power Ti:sapphire laser system

    Energy Technology Data Exchange (ETDEWEB)

    Yamakawa, Koichi; Aoyama, Makoto; Matsuoka, Shinichi; Akahane, Yutaka; Kase, Teiji; Nakano, Fumihiko; Sagisaka, Akito [Advanced Photon Research Center, Kansai Research Establishment, Japan Atomic Energy Research Inst., Kizu, Kyoto (Japan)

    2001-01-01

    We review progress in the generation of multiterawatt optical pulses in the 10-fs range. We describe a design, performance and characterization of a Ti:sapphire laser system based on chirped-pulse amplification, which has produced a peak power in excess of 100-TW with sub-20-fs pulse durations and an average power of 19-W at a 10-Hz repetition rate. We also discuss extension of this system to the petawatt power level and potential applications in the relativistic, ultrahigh intensity regimes. (author)

  5. Liquid crystal dimers

    CERN Document Server

    Kumar Pal, Santanu

    2017-01-01

    This book covers in-depth discussion of design principles, synthesis and thermal behavior of all types of liquid crystal (LC) dimers. The text presents recent advances in the field of LC dimers consisting of different mesogenic units such as calamitic, discotic and bent-core molecules. It starts with a chapter on the introduction of liquid crystal dimers, including their odd-even behavior, basic classification of dimers and common mesophases in dimers. The text shows how the molecular architectures are being used to develop new materials to study a range of interesting phenomena such as the biaxial nematic phase containing rod-like and disc-like mesogenic units. Finally, the text presents perspectives related to technological relevance of these dimers such as dopants in LC display mixtures exhibiting faster relaxation time, strong flexoelectric coupling and others to effect control over the properties of these materials.

  6. Twisted aspirin crystals.

    Science.gov (United States)

    Cui, Xiaoyan; Rohl, Andrew L; Shtukenberg, Alexander; Kahr, Bart

    2013-03-06

    Banded spherulites of aspirin have been crystallized from the melt in the presence of salicylic acid either generated from aspirin decomposition or added deliberately (2.6-35.9 mol %). Scanning electron microscopy, X-ray diffraction analysis, and optical polarimetry show that the spherulites are composed of helicoidal crystallites twisted along the growth directions. Mueller matrix imaging reveals radial oscillations in not only linear birefringence, but also circular birefringence, whose origin is explained through slight (∼1.3°) but systematic splaying of individual lamellae in the film. Strain associated with the replacement of aspirin molecules by salicylic acid molecules in the crystal structure is computed to be large enough to work as the driving force for the twisting of crystallites.

  7. Crystal Indentation Hardness

    Directory of Open Access Journals (Sweden)

    Ronald W. Armstrong

    2017-01-01

    Full Text Available There is expanded interest in the long-standing subject of the hardness properties of materials. A major part of such interest is due to the advent of nanoindentation hardness testing systems which have made available orders of magnitude increases in load and displacement measuring capabilities achieved in a continuously recorded test procedure. The new results have been smoothly merged with other advances in conventional hardness testing and with parallel developments in improved model descriptions of both elastic contact mechanics and dislocation mechanisms operative in the understanding of crystal plasticity and fracturing behaviors. No crystal is either too soft or too hard to prevent the determination of its elastic, plastic and cracking properties under a suitable probing indenter. A sampling of the wealth of measurements and reported analyses associated with the topic on a wide variety of materials are presented in the current Special Issue.

  8. Liquid crystal colloids

    CERN Document Server

    Muševič, Igor

    2017-01-01

    This book brings together the many concepts and discoveries in liquid crystal colloids contributed over the last twenty years and scattered across numerous articles and book chapters. It provides both a historical overview of the development of the field and a clear perspective on the future applications in photonics. The book covers all phenomena observed in liquid crystal colloids with an emphasis on experimental tools and applications of topology in condensed matter, as well as practical micro-photonics applications. It includes a number of spectacular manifestations of new topological phenomena not found or difficult to observe in other systems. Starting from the early works on nematic colloids, it explains the basics of topological defects in ordered media, charge and winding, and the elastic forces between colloidal particles in nematics. Following a detailed description of experimental methods, such as optical tweezing and particle tracking, the book eases the reader into the theoretical part, which de...

  9. Liquid crystals in tribology.

    Science.gov (United States)

    Carrión, Francisco-José; Martínez-Nicolás, Ginés; Iglesias, Patricia; Sanes, José; Bermúdez, María-Dolores

    2009-09-18

    Two decades ago, the literature dealing with the possible applications of low molar mass liquid crystals, also called monomer liquid crystals (MLCs), only included about 50 references. Today, thousands of papers, conference reports, books or book chapters and patents refer to the study and applications of MLCs as lubricants and lubricant additives and efforts are made to develop new commercial applications. The development of more efficient lubricants is of paramount technological and economic relevance as it is estimated that half the energy consumption is dissipated as friction. MLCs have shown their ability to form ordered boundary layers with good load-carrying capacity and to lower the friction coefficients, wear rates and contact temperature of sliding surfaces, thus contributing to increase the components service life and to save energy. This review includes the use of MLCs in lubrication, and dispersions of MLCs in conventional polymers (PDMLCs). Finally, new lubricating system composed of MLC blends with surfactants, ionic liquids or nanophases are considered.

  10. Progress of Pharmaceutical Continuous Crystallization

    Directory of Open Access Journals (Sweden)

    Dejiang Zhang

    2017-06-01

    Full Text Available Crystallization is an important unit operation in the pharmaceutical industry. At present, most pharmaceutical crystallization processes are performed in batches. However, due to product variability from batch to batch and to the low productivity of batch crystallization, continuous crystallization is gaining increasing attention. In the past few years, progress has been made to allow the products of continuous crystallization to meet different requirements. This review summarizes the progress in pharmaceutical continuous crystallization from a product engineering perspective. The advantages and disadvantages of different types of continuous crystallization are compared, with the main difference between the two main types of crystallizers being their difference in residence time distribution. Approaches that use continuous crystallization to meet different quality requirements are summarized. Continuous crystallization has advantages in terms of size and morphology control. However, it also has the problem of a process yield that may be lower than that of a batch process, especially in the production of chirality crystals. Finally, different control strategies are compared.

  11. Crystals against cancer

    CERN Multimedia

    2009-01-01

    This is a remarkable example of direct technology transfer from particle physics to medicine. Clinical trials have begun in Portugal on a new medical imaging system for the diagnosis of breast cancer, which uses positron emission tomography (PET). The system, developed by a Portuguese consortium in collaboration with CERN and laboratories participating in the Crystal Clear collaboration, will detect even the smallest tumours and thus help avoid unnecessary biopsies.

  12. Pyrrolidinium Ionic Liquid Crystals

    OpenAIRE

    Goossens, Karel; Lava, Kathleen; Nockemann, Peter; Van Hecke, Kristof; Van Meervelt, Luc; Driesen, Kris; Görller-Walrand, Christiane; Binnemans, Koen; Cardinaels, Thomas

    2009-01-01

    N-Alkyl-N-methylpyrrolidinium cations have been used for the design of ionic liquid crystals, including a new type of uranium-containing metallomesogen. Pyrrolidinium salts with bromide, bis(trifluoromethylsulfonyl)-imide, tetrafluoroborate, hexafluorophosphate, thiocyanate, tetrakis(2-thenoyltrifluoroacetonato)europate(III) and tetrabromouranyl] counteranions were prepared. For the bromide salts and tetrabromouranyl compounds, the chain length of the alkyl group CnH2n+1 was varied from eight...

  13. LEAR Crystal Barrel Detector

    Energy Technology Data Exchange (ETDEWEB)

    Braune, K.; Keh, S.; Montanet, L.; Zoll, J.; Beckmann, R.; Friedrich, J.; Heinsius, H.; Kiel, T.; Lewendel, B.; Pegel, C.; and others

    1988-11-20

    The features of the Crystal Barrel Detector which is in preparation for LEAR at CERN, are discussed. The physics aims include q-barq- and exotics-spectroscopy and a detailed investigation of yet unknown p-barp-anihilation channels. An eventual later use on the PSI-B-Meson-Factory is discussed. The paper finishes with a description of the present status of the project.

  14. Magnetic photonic crystals

    Energy Technology Data Exchange (ETDEWEB)

    Lyubchanskii, I L [Donetsk Physical and Technical Institute of the National Academy of Sciences of Ukraine, 72, R. Luxemburg St., 83114 Donetsk (Ukraine); Dadoenkova, N N [Donetsk Physical and Technical Institute of the National Academy of Sciences of Ukraine, 72, R. Luxemburg St., 83114 Donetsk (Ukraine); Lyubchanskii, M I [Donetsk Physical and Technical Institute of the National Academy of Sciences of Ukraine, 72, R. Luxemburg St., 83114 Donetsk (Ukraine); Shapovalov, E A [Department of Physics, Donetsk National University, 24, Universitetskaya St., 83055 Donetsk (Ukraine); Rasing, Th [NSRIM Institute, University of Nijmegen, 6525 ED, Nijmegen (Netherlands)

    2003-09-21

    In this paper we outline a new direction in the area of photonic crystals (PCs), or photonic band gap materials, i.e. one-, two-, or three-dimensional superstructures with periods that are comparable with the wavelengths of electromagnetic radiation. The main (and principal) characteristic of this new class of PCs is the presence of magnetically ordered components (or external magnetic field). The linear and nonlinear optical properties of such magnetic PCs are discussed. (topical review)

  15. High peak power Q-switched Er:YAG laser with two polarizers and its ablation performance for hard dental tissues.

    Science.gov (United States)

    Yang, Jingwei; Wang, Li; Wu, Xianyou; Cheng, Tingqing; Jiang, Haihe

    2014-06-30

    An electro-optically Q-switched high-energy Er:YAG laser with two polarizers is proposed. By using two Al(2)O(3) polarizing plates and a LiNbO(3) crystal with Brewster angle, the polarization efficiency is significantly improved. As a result, 226 mJ pulse energy with 62 ns pulse width is achieved at the repetition rate of 3 Hz, the corresponding peak power is 3.6 MW. To our knowledge, such a high peak power has not been reported in literature. With our designed laser, in-vitro teeth were irradiated under Q-switched and free-running modes. Results of a laser ablation experiment on hard dental tissue with the high-peak-power laser demonstrates that the Q-switched Er:YAG laser has higher ablation precision and less thermal damage than the free-running Er:YAG laser.

  16. Phononic crystals fundamentals and applications

    CERN Document Server

    Adibi, Ali

    2016-01-01

    This book provides an in-depth analysis as well as an overview of phononic crystals. This book discusses numerous techniques for the analysis of phononic crystals and covers, among other material, sonic and ultrasonic structures, hypersonic planar structures and their characterization, and novel applications of phononic crystals. This is an ideal book for those working with micro and nanotechnology, MEMS (microelectromechanical systems), and acoustic devices. This book also: Presents an introduction to the fundamentals and properties of phononic crystals Covers simulation techniques for the analysis of phononic crystals Discusses sonic and ultrasonic, hypersonic and planar, and three-dimensional phononic crystal structures Illustrates how phononic crystal structures are being deployed in communication systems and sensing systems.

  17. Peak oxygen uptake and ventilatory anaerobic threshold in fibromyalgia.

    Science.gov (United States)

    Valim, Valéria; Oliveira, Leda M; Suda, Alina L; Silva, Luciana E; Faro, Mário; Neto, Turíbio L Barros; Feldman, Daniel; Natour, Jamil

    2002-02-01

    To compare maximum oxygen uptake and anaerobic threshold in patients with fibromyalgia (FM) and healthy sedentary controls matched by sex, age, weight, and body mass index. Fifty women with FM aged 18-60 years and 50 healthy sedentary controls were studied. All were submitted to a maximum treadmill incremental test. Expired gas, ventilatory anaerobic threshold, and maximum oxygen uptake (VO2max) were evaluated. The influence of FM on quality of life was evaluated by questionnaires: the Fibromyalgia Impact Questionnaire and the Medical Outcomes Study Short-Form (SF-36). In patients with FM, the anaerobic threshold and peak oxygen uptake were significantly reduced. Maximum heartbeat rate was significantly lower in FM, indicating submaximum effort. Linear regression data showed a correlation between peak VO2 and the "Role-physical" domain of the SF-36. No such correlations were noted with anaerobic threshold. These results confirm the hypothesis of lower physical fitness in patients with FM. Considering that patients with FM do not achieve a maximum effort, ventilatory anaerobic threshold should be considered as a better fitness index than VO2max.

  18. Comparison of peak muscle power between Brazilian and French girls.

    Science.gov (United States)

    Nanci Maria, França; Eric, Doré; Mario, Bedu; Emmanuel, Van Praagh

    2002-01-01

    This study examined the muscle power of Brazilian circumpubertal girls and extended the analysis to a cross-cultural dimension. A total of 462 children, 123 Brazilian girls and 339 French girls, 9-18 years, participated in this investigation. Anthropometric data included body mass (BM), height, skinfold thicknesses, and estimated lean leg volume (LLV). All subjects completed a physical activity questionnaire. Cycling peak power was measured including the flywheel inertia of the device (CPPi). Brazilian girls self-assessed their maturation using pubic hair development. CPPi and optimal velocity (v(opt) = velocity at CPPi) increased with stages of puberty. A multiple stepwise regression with anthropometric variables as explanatory factors showed only LLV and age explaining the variance of CPPi (R2 = 0.40, P CPPi in Brazilian girls was related to undetermined qualitative individual factors, which may be related to cycling skill. Even when normalized for anthropometric variables, the anaerobic performance (CPPi and v(opt)) of Brazilian girls was significantly lower than a cohort of French girls. The latter demonstrated a high participation in sport and training activities, while 50% of the Brazilian girls had only physical education classes in the form of regular physical activity. Moreover, most of the Brazilian girls demonstrated an ineffective sprint cycling skill. The data suggest that motor learning is an important issue in muscle power assessment and might, therefore, partially explain peak power differences in Brazilian compared with French girls. Copyright 2002 Wiley-Liss, Inc.

  19. Using Energy Peaks to Measure New Particle Masses

    CERN Document Server

    Agashe, Kaustubh; Kim, Doojin

    2014-01-01

    We discussed in arXiv:1209.0772 that the laboratory frame distribution of the energy of a massless particle from a two-body decay at a hadron collider has a peak whose location is identical to the value of this daughter's (fixed) energy in the rest frame of the corresponding mother particle. For that result to hold we assumed that the mother is unpolarized and has a generic boost distribution in the laboratory frame. In this work we discuss how this observation can be applied for determination of masses of new particles, without requiring a full reconstruction of their decay chains or information about the rest of the event. We focus on a two-step cascade decay of a massive particle that has one invisible particle in the final state: C -> Bb -> Aab, where C, B and A are new particles of which A is invisible and a, b are visible particles. Combining the measurements of the peaks of energy distributions of a and b with that of the edge in their invariant mass distribution, we demonstrate that it is in principle...

  20. Acetaminophen overdose associated with double serum concentration peaks

    Directory of Open Access Journals (Sweden)

    Cristian Papazoglu

    2015-12-01

    Full Text Available Acetaminophen is the most commonly used analgesic–antipyretic medication in the United States. Acetaminophen overdose, a frequent cause of drug toxicity, has been recognized as the leading cause of fatal and non-fatal hepatic necrosis. N-Acetylcysteine is the recommended antidote for acetaminophen poisoning. Despite evidence on the efficacy of N-acetylcysteine for prevention of hepatic injury, controversy persists about the optimal duration of the therapy. Here, we describe the case of a 65-year-old male with acetaminophen overdose and opioid co-ingestion who developed a second peak in acetaminophen serum levels after completing the recommended 21-hour intravenous N-acetylcysteine protocol and when the standard criteria for monitoring drug levels was achieved. Prolongation of N-acetylcysteine infusion beyond the standard protocol, despite a significant gap in treatment, was critical for successful avoidance of hepatotoxicity. Delay in acetaminophen absorption may be associated with a second peak in serum concentration following an initial declining trend, especially in cases of concomitant ingestion of opioids. In patients with acetaminophen toxicity who co-ingest other medications that may potentially delay gastric emptying or in those with risk factors for delayed absorption of acetaminophen, we recommend close monitoring of aminotransferase enzyme levels, as well as trending acetaminophen concentrations until undetectable before discontinuing the antidote therapy.

  1. GRB physics and cosmology with peak energy-intensity correlations

    Energy Technology Data Exchange (ETDEWEB)

    Sawant, Disha, E-mail: sawant@fe.infn.it [University of Ferrara, Via Saragat-1, Block C, Ferrara 44122 (Italy); University of Nice, 28 Avenue Valrose, Nice 06103 (France); IRAP Erasmus PhD Program, European Union and INAF - IASF Bologna, Via P. Gobetti 101, Bologna 41125 (Italy); Amati, Lorenzo, E-mail: amati@iasfbo.inaf.it [INAF - IASF Bologna, Via P. Gobetti 101, Bologna 41125 (Italy); ICRANet, Piazzale Aldo Moro-5, Rome 00185 (Italy)

    2015-12-17

    Gamma Ray Bursts (GRBs) are immensely energetic explosions radiating up to 10{sup 54} erg of energy isotropically (E{sub iso}) and they are observed within a wide range of redshift (from ∼ 0.01 up to ∼ 9). Such enormous power and high redshift point at these phenomena being highly favorable to investigate the history and evolution of our universe. The major obstacle in their application as cosmological study-tools is to find a way to standardize the GRBs, for instance similar to SNe Ia. With respect to this goal, the correlation between spectral peak energy (E{sub p,i}) and the “intensity” is a positively useful and investigated criterion. Moreover, it has been demonstrated that, through the E{sub p,i} – E{sub iso} correlation, the current data set of GRBs can already contribute to the independent evidence of the matter density Ω{sub M} being ∼ 0.3 for a flat universe scenario. We try to inspect and compare the correlations of E{sub p,i} with different intensity indicators (e.g., radiated energy, average and peak luminosity, bolometric vs. monochromatic quantities, etc.) both in terms of intrinsic dispersion and precise estimation of Ω{sub M}. The outcome of such studies are further analyzed in verifying the reliability of the correlations for both GRB physics and their standardization for cosmology.

  2. Instabilities in liquid crystals

    CERN Document Server

    Barclay, G J

    1998-01-01

    and we examine the differences which occur for differing dielectric anisotropies. Finally, in Chapter 7 we study how a sample of smectic C liquid crystal behaves when it is subjected to a uniform shear flow within the smectic plane. We find travelling wave solutions for the behaviour of the c-director and adapt these solutions to incorporate the effects of an applied field. This thesis contains theoretical work dealing with the effects of magnetic and electric fields on samples of nematic, smectic A and smectic C liquid crystals. Some background material along with the continuum theory is introduced in Chapter 2. In Chapter 3 we consider the effect on the director within an infinite sample of nematic liquid crystal which is subjected to crossed electric and magnetic fields. In particular we examine the stability of the travelling waves which describe the director motion by considering the behaviour of the stable perturbations as time increases. The work of Chapter 4 examines a bounded sample of smectic A liqu...

  3. Subwavelength-Diameter Silica Wire and Photonic Crystal Waveguide Slow Light Coupling

    Directory of Open Access Journals (Sweden)

    Ziyang Zhang

    2007-01-01

    Full Text Available Counter-directional coupling between subwavelength-diameter silica wire and single-line-defect two-dimensional photonic crystal slab waveguide is studied numerically using parallel three-dimensional finite-different time-domain method. By modifying silica wire properties or engineering photonic crystal waveguide dispersion band, the coupling central wavelength can be moved to the slow light region and the coupling efficiency improves simultaneously. One design gives 82% peak power transmission from silica wire to photonic crystal waveguide over an interacting distance of 50 lattice constants. The group velocity is estimated as 1/35 of light speed in vacuum.

  4. Advantages of axially aligned crystals used in positron production at future linear colliders

    Directory of Open Access Journals (Sweden)

    X. Artru

    2003-09-01

    Full Text Available The characteristics of the electron-photon showers initiated by 2 to 10 GeV electrons aligned along the ⟨111⟩ axis of tungsten crystals are compared with those for the amorphous tungsten. In this energy range, as known, the positron yield at the optimal target thicknesses is larger in a crystal case only by several percent. However, the amount of the energy deposition in a crystal turns out to be considerably (by 20%–50% lower than in an amorphous target providing the same positron yield, while the peak energy-deposition density is approximately of the same magnitude in both cases.

  5. Crystallization Age and Source Signature of Chassigny

    Science.gov (United States)

    Misawa, K.; Shih, C.-Y.; Reese, Y.; Nyquist, L. E.

    2005-01-01

    Chassigny is the Martian dunite composed of cumulate olivine (92%), chromite (1.4%), pyroxene (5%) and interstitial feldspar (1.7%). Although nakhlites (clinopyroxenite) are less intensely affected by shock metamorphism, Chassigny has been subjected to a peak shock pressure of about 35 GPa. The cosmic-ray exposure age of Chassigny (11.3 +/- 0.6 Ma) is comparable to those of nakhlites, suggesting launch pairing of these meteorites. Prior chemical and isotopic studies of Chassigny suggest that the meteorite crystallized approx. 1.3 Ga ago and is closely related to nakhlites. Nevertheless, compared to other Martian meteorites there are limited isotopic data for Chassigny. To examine the relationship of Chassigny to nakhlites, we have undertaken new Rb-Sr and Sm-Nd isotopic studies. Here we present the new Sm-Nd isotopic data for Chassigny and discuss the nature of its source materials.

  6. The effect of crystal morphology and mill type on milling induced crystal disorder.

    Science.gov (United States)

    Chikhalia, V; Forbes, R T; Storey, R A; Ticehurst, M

    2006-01-01

    Milling is a key process in the preparation of many solid dosage forms. One possible milling induced change is the production of small levels of disorder or amorphous material found predominantly at the surface of a powder, which could lead to significant chemical and physical instability. The influence of crystal habit on this change was investigated using beta-succinic acid, in plate like and needle like morphologies. beta-Succinic acid crystals with these habits were processed in a ball mill and a jet mill. SEM images indicated jet milled material was finer than the ball milled product. Powder X-ray diffraction of the milled powders revealed an amorphous halo at lower angles and peak broadening suggesting disorder though this could not be quantified accurately. In addition, a partial conversion during milling to the alpha form was noted. Quantitation of the alpha form in the milled powders indicated it was present at powders had lower heats of solution compared to the unmilled powers. The contribution of the alpha polymorph to the lower heats of solution was calculated to be insignificant. Therefore, the reduced heat of solution is attributed to a loss in crystallinity. The largest decreases were seen in the plate like morphology. These findings suggest that beta-succinic acid crystals with plate like morphology are more prone to crystallinity loss on milling compared to the needle like morphology. The mill type has also been shown to influence the final crystallinity.

  7. Technical Potential for Peak Load Management Programs in New Jersey

    Energy Technology Data Exchange (ETDEWEB)

    Kirby, B.J.

    2002-12-13

    Restructuring is attempting to bring the economic efficiency of competitive markets to the electric power industry. To at least some extent it is succeeding. New generation is being built in most areas of the country reversing the decades-long trend of declining reserve margins. Competition among generators is typically robust, holding down wholesale energy prices. Generators have shown that they are very responsive to price signals in both the short and long term. But a market that is responsive only on the supply side is only half a market. Demand response (elasticity) is necessary to gain the full economic advantages that restructuring can offer. Electricity is a form of energy that is difficult to store economically in large quantities. However, loads often have some ability to (1) conveniently store thermal energy and (2) defer electricity consumption. These inherent storage and control capabilities can be exploited to help reduce peak electric system consumption. In some cases they can also be used to provide system reliability reserves. Fortunately too, technology is helping. Advances in communications and control technologies are making it possible for loads ranging from residential through commercial and industrial to respond to economic signals. When we buy bananas, we don't simply take a dozen and wait a month to find out what the price was. We always ask about the price before we decide how many bananas we want. Technology is beginning to allow at least some customers to think about their electricity consumption the same way they think about most of their other purchases. And power system operators and regulators are beginning to understand that customers need to remain in control of their own destinies. Many customers (residential through industrial) are willing to respond to price signals. Most customers are not able to commit to specific responses months or years in advance. Electricity is a fluid market commodity with a volatile value to both

  8. A Study of the Crystallization, Melting, and Foaming Behaviors of Polylactic Acid in Compressed CO2

    Science.gov (United States)

    Zhai, Wentao; Ko, Yoorim; Zhu, Wenli; Wong, Anson; Park, Chul B.

    2009-01-01

    The crystallization and melting behaviors of linear polylactic acid (PLA) treated by compressed CO2 was investigated. The isothermal crystallization test indicated that while PLA exhibited very low crystallization kinetics under atmospheric pressure, CO2 exposure significantly increased PLA’s crystallization rate; a high crystallinity of 16.5% was achieved after CO2 treatment for only 1 min at 100 °C and 6.89 MPa. One melting peak could be found in the DSC curve, and this exhibited a slight dependency on treatment times, temperatures, and pressures. PLA samples tended to foam during the gas release process, and a foaming window as a function of time and temperature was established. Based on the foaming window, crystallinity, and cell morphology, it was found that foaming clearly reduced the needed time for PLA’s crystallization equilibrium. PMID:20054476

  9. A Study of the Crystallization, Melting, and Foaming Behaviors of Polylactic Acid in Compressed CO2

    Directory of Open Access Journals (Sweden)

    Chul B. Park

    2009-12-01

    Full Text Available The crystallization and melting behaviors of linear polylactic acid (PLA treated by compressed CO2 was investigated. The isothermal crystallization test indicated that while PLA exhibited very low crystallization kinetics under atmospheric pressure, CO2 exposure significantly increased PLA’s crystallization rate; a high crystallinity of 16.5% was achieved after CO2 treatment for only 1 min at 100 °C and 6.89 MPa. One melting peak could be found in the DSC curve, and this exhibited a slight dependency on treatment times, temperatures, and pressures. PLA samples tended to foam during the gas release process, and a foaming window as a function of time and temperature was established. Based on the foaming window, crystallinity, and cell morphology, it was found that foaming clearly reduced the needed time for PLA’s crystallization equilibrium.

  10. Terahertz Vibrations and Hydrogen-Bonded Networks in Crystals

    Directory of Open Access Journals (Sweden)

    Masae Takahashi

    2014-03-01

    Full Text Available The development of terahertz technology in the last few decades has made it possible to obtain a clear terahertz (THz spectrum. THz vibrations clearly show the formation of weak bonds in crystals. The simultaneous progress in the code of first-principles calculations treating noncovalent interactions has established the position of THz spectroscopy as a powerful tool for detecting the weak bonding in crystals. In this review, we are going to introduce, briefly, the contribution of weak bonds in the construction of molecular crystals first, and then, we will review THz spectroscopy as a powerful tool for detecting the formation of weak bonds and will show the significant contribution of advanced computational codes in treating noncovalent interactions. From the second section, following the Introduction, to the seventh section, before the conclusions, we describe: (1 the crystal packing forces, the hydrogen-bonded networks and their contribution to the construction of organic crystals; (2 the THz vibrations observed in hydrogen-bonded molecules; (3 the computational methods for analyzing the THz vibrations of hydrogen-bonded molecules; (4 the dispersion correction and anharmonicity incorporated into the first-principles calculations and their effect on the peak assignment of the THz spectrum (5 the temperature dependence; and (6 the polarization dependence of the THz spectrum.

  11. Self Nucleation and Crystallization of Poly(vinyl alcohol)

    Science.gov (United States)

    Thomas, David; Cebe, Peggy

    Polyvinyl alcohol (PVA) is a hydrophilic, biodegradable, semi-crystalline polymer with uses ranging from textiles to medicine. Film samples of PVA were investigated to assess crystallization and melting behavior during self-nucleation experiments, and thermal degradation, using differential scanning calorimetry (DSC) and thermogravimetric (TG) analysis, respectively. TG results show that degradation occurred at temperatures close to the observed peak melting temperature of 223 C. Using conventional DSC, PVA was heated at a rate of 10 C/min to various self-nucleation temperatures, Ts, within its melting range, briefly annealed, cooled and reheated. Three distinct crystallization regimes were observed upon cooling, depending upon self nucleation temperature. At low values of Ts, below 227 C, PVA only partially melts; residual crystal anneals while new, less perfect crystals form during cooling. Between 228 C and 234 C, PVA was found to crystallize exclusively by self-nucleation. For Ts above 235 C the PVA melts completely. Fast scanning chip-based calorimetry was used to heat and cool at 2000 K/s, to prevent degradation. Results of self nucleation experiments using fast scanning and conventional DSC will be compared. NSF DMR-1206010.

  12. Study of pure and L-tartaric acid doped ammonium dihydrogen phosphate single crystals: A novel nonlinear optical non-centrosymmetric crystal

    Energy Technology Data Exchange (ETDEWEB)

    Hasmuddin, Mohd, E-mail: mhasmu@gmail.com [Crystal Growth Laboratory, Dept. of Physics, Jamia Millia Islamia, New Delhi 110 025 (India); Singh, Preeti [Crystal Growth Laboratory, Dept. of Physics, Jamia Millia Islamia, New Delhi 110 025 (India); Shkir, Mohd [Crystal Growth Laboratory, Dept. of Physics, Jamia Millia Islamia, New Delhi 110 025 (India); Department of Physics, School of Science, King Khalid University, P.O. Box. 9004, Abha 61413 (Saudi Arabia); Abdullah, M.M. [Crystal Growth Laboratory, Dept. of Physics, Jamia Millia Islamia, New Delhi 110 025 (India); Promising Centre for Sensors and Electronic Devices (PCSED), Department of Physics, College of Science and Arts, Najran University, P.O. Box 1988, Najran 11001 (Saudi Arabia); Vijayan, N. [CSIR – National Physical Laboratory, Dr. K. S. Krishnan Road, New Delhi 110 012 (India); Ganesh, V. [Department of Physics, Kakatiya University, Warangal, Andhra Pradesh 506009 (India); Wahab, M.A., E-mail: mwahab@jmi.ac.in [Crystal Growth Laboratory, Dept. of Physics, Jamia Millia Islamia, New Delhi 110 025 (India)

    2014-04-01

    Single crystals of pure and L-tartaric acid (LTA) C{sub 4}H{sub 6}O{sub 6} doped ammonium dihydrogen phosphate (ADP) (NH{sub 4}) H{sub 2}PO{sub 4} were grown by slow evaporation solution technique (SEST) at ambient conditions. Powder X-ray diffraction (PXRD) analysis was carried out to confirm the crystal structure and no additional phase was observed due to doping except a systematic variation in peak intensities. Fourier transform infrared spectral analysis was done to examine the presence of various functional groups in the grown crystals. UV–VIS–NIR spectroscopic analysis was carried out to see the change in optical transparency of pure ADP and crystals due to LTA with different doping concentrations. Second harmonic generation (SHG) efficiency measurement was done to examine the enhancement in the nonlinear optical characteristics of the grown crystals. The effect of LTA dopant on crystal morphology, thermal and mechanical properties of ADP have also been presented in this paper. The above studies reveal the effect of incorporation of LTA into the lattice of ADP crystals. - Highlights: • LTA doped ADP crystals were grown for the first time. • Optical transmission was found to be higher at 1 mol% LTA doping. • SHG was found to be enhanced nonlinearly due to doping. • Thermal stability was found to higher at 1 mol% LTA doping. • Hardness was found to be increases with doping.

  13. DOA Estimation with Local-Peak-Weighted CSP

    Directory of Open Access Journals (Sweden)

    Osamu Ichikawa

    2010-01-01

    Full Text Available This paper proposes a novel weighting algorithm for Cross-power Spectrum Phase (CSP analysis to improve the accuracy of direction of arrival (DOA estimation for beamforming in a noisy environment. Our sound source is a human speaker and the noise is broadband noise in an automobile. The harmonic structures in the human speech spectrum can be used for weighting the CSP analysis, because harmonic bins must contain more speech power than the others and thus give us more reliable information. However, most conventional methods leveraging harmonic structures require pitch estimation with voiced-unvoiced classification, which is not sufficiently accurate in noisy environments. In our new approach, the observed power spectrum is directly converted into weights for the CSP analysis by retaining only the local peaks considered to be harmonic structures. Our experiment showed the proposed approach significantly reduced the errors in localization, and it showed further improvements when used with other weighting algorithms.

  14. Energy solutions for CO2 emission peak and subsequent decline

    DEFF Research Database (Denmark)

    Risø International Energy Conference 2009 took place 14 – 16 September 2009. The conference focused on: • Future global energy development options Scenario and policy issues • Measures to achieve CO2 emission peak in 2015 – 2020 and subsequent decline • Renewable energy supply technologies...... such as bioenergy, wind and solar • Centralized energy technologies such as clean coal technologies • Energy conversion, energy carriers and energy storage, including fuel cells and hydrogen technologies • Providing renewable energy for the transport sector • Systems aspects for the various regions throughout...... the world • End-use technologies, efficiency improvements in supply and end use • Energy savings The proceedings are prepared from papers presented at the conference and received with corrections, if any, until the final deadline on 3 August 2009....

  15. Implications of "peak oil" for atmospheric CO2 and climate

    CERN Document Server

    Kharecha, P A

    2007-01-01

    Peaking of global oil production may have a large effect on future atmospheric CO2 amount and climate change, depending upon choices made for subsequent energy sources. We suggest that, if estimates of oil and gas reserves by the Energy Information Administration are realistic, it is feasible to keep atmospheric CO2 from exceeding approximately 450 ppm, provided that future exploitation of the huge reservoirs of coal and unconventional fossil fuels incorporates carbon capture and sequestration. Existing coal-fired power plants, without sequestration, must be phased out before mid-century to achieve this limit on atmospheric CO2. We also suggest that it is important to "stretch" oil reserves via energy efficiency, thus avoiding the need to extract liquid fuels from coal or unconventional fossil fuels. We argue that a rising price on carbon emissions is probably needed to keep CO2 beneath the 450 ppm ceiling.

  16. Remote observing experiments at Kitt Peak National Observatory

    Science.gov (United States)

    Robinson, W. G.; Schechter, P. L.; Janes, C. C.

    1982-10-01

    The results of trial runs using telephone links to the Kitt Peak Observatory to permit astronomers to make use of the instrumentation from remote sites are reported. Three lines permit voice communication with the telescope operator, interfacing with the telescope computer, and television hook-up to the telescope image acquisition system. One complete picture frame is furnished every 34 sec over the modem. A commercial direct-dial long distance line was found to have a relatively acceptable noise level. The best operation was performed using the intensified image dissector scanner on a 2.1 m telescope. Satisfactory operation and controllability was reported from a user located over a thousand miles away. Further attempts will be made to add a CCD system and a Fourier transform spectrometer to the equipment that can be remotely operated. An expansion in the communications equipment and collaborative programs with other observatories are recommended in order to expand the program to more users.

  17. Enzyme engineering: reaching the maximal catalytic efficiency peak.

    Science.gov (United States)

    Goldsmith, Moshe; Tawfik, Dan S

    2017-10-13

    The practical need for highly efficient enzymes presents new challenges in enzyme engineering, in particular, the need to improve catalytic turnover (kcat) or efficiency (kcat/KM) by several orders of magnitude. However, optimizing catalysis demands navigation through complex and rugged fitness landscapes, with optimization trajectories often leading to strong diminishing returns and dead-ends. When no further improvements are observed in library screens or selections, it remains unclear whether the maximal catalytic efficiency of the enzyme (the catalytic 'fitness peak') has been reached; or perhaps, an alternative combination of mutations exists that could yield additional improvements. Here, we discuss fundamental aspects of the process of catalytic optimization, and offer practical solutions with respect to overcoming optimization plateaus. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Day-time seeing statistics at Sacramento Peak Observatory

    Science.gov (United States)

    Brandt, P. N.; Mauter, H. A.; Smartt, R.

    1987-12-01

    A method for the photoelectric measurement of angle-of-arrival fluctuations at the solar limb is described, from which Fried's seeing parameter r0 can be determined. From a set of 2092 measurements, each of 10 s duration, performed on 146 observing days in the period from June 84 to September 86 at the solar vacuum tower telescope of the Sacramento Peak Observatory, a log-normal distribution of the r0 values gave a median r0 = 8.7 cm (measured at λ = 510 nm), with a standard deviation σ = 0.25 in logarithmic units. The results are compared with atmospheric sounding experiment data and longterm day- and night-time seeing statistics obtained at other observatories.

  19. Hvordan gør musikken i Twin Peaks?

    Directory of Open Access Journals (Sweden)

    Ansa Lønstrup

    1992-08-01

    Full Text Available Det er almindelig erkendt, at musikken spiller en afgørende rolle for den totale oplevelse af film og TV. Men det glemmes ofte igen, især i fortolk- ninger, der focuserer på handlingen og ser bort fra musikken og måske også den visuelle formidling. Tendensen til at "glemme" musikken i fortolkningen skyldes især, at den er svær at beskrive og svær at analysere. Ansa Lønstrups analyse af musikkens rolle i TV-serien Twin Peaks er en eksemplarisk gennem- gang af hvorledes musikken skaber betydning. Den er samtidig et bidrag til forståelsen af netop denne serie, der bl.a. udmærker sig ved, at den næppe kan begribes uden at musikken bliver en del af oplevelse og tolk- ning.

  20. Peptidomic profile of milk of Holstein cows at peak lactation.

    Science.gov (United States)

    Dallas, David C; Guerrero, Andres; Parker, Evan A; Garay, Luis A; Bhandari, Aashish; Lebrilla, Carlito B; Barile, Daniela; German, J Bruce

    2014-01-08

    Bovine milk is known to contain naturally occurring peptides, but relatively few of their sequences have been determined. Human milk contains hundreds of endogenous peptides, and the ensemble has been documented for antimicrobial actions. Naturally occurring peptides from bovine milk were sequenced and compared with human milk peptides. Bovine milk samples from six cows in second-stage peak lactation at 78-121 days postpartum revealed 159 peptides. Most peptides (73%) were found in all six cows sampled, demonstrating the similarity of the intramammary peptide degradation across these cows. One peptide sequence, ALPIIQKLEPQIA from bovine perilipin 2, was identical to another found in human milk. Most peptides derived from β-casein, αs1-casein, and αs2-casein. No peptides derived from abundant bovine milk proteins such as lactoferrin, β-lactoglobulin, and secretory immunoglobulin A. The enzymatic cleavage analysis revealed that milk proteins were degraded by plasmin, cathepsins B and D, and elastase in all samples.

  1. Self-standing bent silicon crystals for very high efficiency Laue lens

    Science.gov (United States)

    Bellucci, Valerio; Camattari, Riccardo; Guidi, Vincenzo; Neri, Ilaria; Barrière, Nicolas

    2011-08-01

    Silicon mono-crystals have been bent thanks to a series of parallel superficial indentations on one of the largest faces of the crystals. This technique relies on irreversible compression of the crystal beneath and beside the indentations. This latter causes deformation with no need for external device, resulting in a uniform self-standing curvature within the crystal. Indented Si crystals have been characterized at European Synchrotron Radiation Facility using a monochromatic beam ranging from 150 to 700 keV. Crystals exhibited very high diffraction efficiency over a broad range of energy, peaking 95% at 150 keV. Measured angular spread of the diffracted beam was always very close to the morphological curvature of the sample under investigation, proving that the energy passband of bent crystals can be controlled by simply imparting a selected curvature to the sample. The method of superficial indentations was found to offer high reproducibility and easy control of diffraction properties of the crystals. Moreover the method is cheap and simple, being based on mass production tools. A Laue lens made of crystals bent by superficial indentations can provide high-efficiency concentration of hard x-ray photons, leading significant improvement in many astrophysical applications.

  2. Digital silicon photomultiplier readout of a new fast and bright scintillation crystal (Ce:GFAG)

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yong-Seok [Department of Bio-convergence Engineering, Korea University, Seoul (Korea, Republic of); Leem, Hyun-Tae [Molecular Imaging Research & Education (MiRe) Laboratory, Department of Electronic Engineering, Sogang University, Seoul (Korea, Republic of); Yamamoto, Seiichi [Department of Medical Technology, Nagoya University Graduate School of Medicine, Nagoya (Japan); Choi, Yong, E-mail: ychoi@sogang.ac.kr [Molecular Imaging Research & Education (MiRe) Laboratory, Department of Electronic Engineering, Sogang University, Seoul (Korea, Republic of); Kamada, Kei [New Industry Creation Hatchery Center (NICHe), Tohoku University, Sendai (Japan); C& A corporation, Sendai (Japan); Yoshikawa, Akira [New Industry Creation Hatchery Center (NICHe), Tohoku University, Sendai (Japan); C& A corporation, Sendai (Japan); Institute for Material Research, Tohoku University, Sendai (Japan); Park, Sang-Geon [Department of Electrical & Electronics, Silla University, Pusan (Korea, Republic of); Yeom, Jung-Yeol, E-mail: jungyeol@korea.ac.kr [Department of Bio-convergence Engineering, Korea University, Seoul (Korea, Republic of); School of Biomedical Engineering, Korea University, Seoul (Korea, Republic of)

    2016-10-01

    A new Gadolinium Fine Aluminum Gallate (Ce:GFAG) scintillation crystal with both high energy resolution and fast timing properties has successfully been grown. Compared to Gd{sub 3}Al{sub 2}Ga{sub 3}O{sub 12} (Ce:GAGG), this new inorganic scintillation crystal has a high luminosity similar to and a faster decay time. In this paper, we report on the timing and energy performance results of the new GFAG scintillation crystal read out with digital silicon photomultipliers (dSiPM) for positron emission tomography (PET) application. The best coincidence resolving time (FWHM) of polished 3×3×5 mm{sup 3} crystals was 223±6 ps for GFAG crystals compared to 396±28 ps for GAGG crystals and 131±3 ps for LYSO crystals respectively. An energy resolution (511 keV peak of Na-22) of 10.9±0.2% was attained with GFAG coupled to dSiPM after correcting for saturation effect, compared to 9.5±0.3% for Ce:GAGG crystals and 11.9±0.4% for LYSO crystals respectively. It is expected that this new scintillator may be competitive in terms of overall properties such as energy resolution, timing resolution and growing (raw material) cost, compared to existing scintillators for positron emission tomography (PET).

  3. Classification of peaked spectrum sources by using neural networks

    Science.gov (United States)

    Vera, R. J. C.; Tornikoski, M.; Lähteenmäki, A.

    2017-07-01

    Compact steep-spectrum sources (CSS), high frequency peakers (HFP), and gigahertz-peaked spectrum sources (GPS) are compact radio sources with an intense emission (O'Dea 1998, and references therein). Morphological studies, dense gas analyses, and surveys suggesting the absence of a halo diffusion emission, suggest the idea that peaked spectrum sources (PSS) are young AGN (see, Fanti et al. 1995; Readhead et al. 1996; Stanghellini et al. 1997; Bicknell et al. 1997). Previously, Torniainen et al. (2008) carried out a study of GPS sources, finding that those sources do not follow a distinct morphological classification. In addition, they found that many blazars in a flaring state are misclassified as GPS sources (Torniainen et al. 2005). These findings compromised the simple vision of the g alaxy-quasar dualism, and the amount of genuine GPS sources. For this reason, we endeavour a new classification of 363 sources with the aim to find new insights about their spectral properties using neural networks. Through clustering methods, we have grouped galaxies that present a set of similar physical properties. In total, 18 physical variables were used for this purpose. In particular, we used Multi-dimensional Scaling (MDS) and t-distributed Stochastic Neighbour Embedding (t-SNE) analyses. Those analyses proved to be robust for analysing data of the order of hundreds of data. From our analyses, we were unable to find a clear classification for PSS. Moreover, new galaxies presented a flat spectra emission, or high variability in the radio emission, compromising their classification as genuine PSS.

  4. Analysis of Subway Interior Noise at Peak Commuter Time.

    Science.gov (United States)

    Lee, Donguk; Kim, Gibbeum; Han, Woojae

    2017-07-01

    Although mass transit systems are convenient and efficient for urban people, little attention has been paid to the potential hearing hazard from their noise. The purpose of the current study was to measure and analyze levels of subway interior noise at peak commuter times and to provide information about commuters' daily dose of noise exposure. To measure the subway interior noise, nine subway lines inside Seoul (i.e., lines 1-9) and six lines surrounding the capital city area (i.e., Central, Bundang, Sinbundang, Incheon, Gyeongui, and Gyeongchun) were chosen. The noise was measured and recorded by a sound level meter for two-hour periods in the morning and evening. 1) In the LZeq analysis, the average noise level of all 15 lines was 72.78 dB; the maximum and minimum noise levels were 78.34 and 62.46 dB, respectively. The average noise level of the nine lines inside Seoul was 73.45 dB, which was 1.68-dB louder than that of the six lines surrounding the capital city area. 2) Based on the LZeq analysis of 33 measured frequencies, 12.5 Hz was the highest frequency and 20,000 Hz was the lowest. 3) There was no remarkable difference in the level of subway interior noise between morning and evening peak commuter times. We concluded that the level of subway interior noise was not loud enough for commuters to incur noise-induced hearing loss. Regardless, environmental noise control efforts in the subway system might be needed for commuters who take a subway every day.

  5. Income and the midlife peak in common mental disorder prevalence.

    Science.gov (United States)

    Lang, I A; Llewellyn, D J; Hubbard, R E; Langa, K M; Melzer, D

    2011-07-01

    The prevalence of psychological distress and common mental disorders has been shown to peak in midlife but analyses have ignored the association of poor material circumstances with prevalence. This study aimed to test the hypothesis that the midlife prevalence peak occurs only in lower-income households. Pooled data were used from the annual Health Survey for England, a nationally representative cross-sectional study, on community-dwelling individuals aged ≥ 16 years from years 1997 to 2006 (n=100 457). 12-item General Health Questionnaire scores, reported mental illness diagnoses and receipt of relevant medication were assessed in relation to household income and age. Analyses were separated by gender and adjusted for age, ethnicity, smoking, social class, education and co-morbidities. Prevalence of psychological distress, diagnoses and treatments rose with age until early middle age and declined subsequently. In analyses conducted separately by income categories, this pattern was marked in low-income groups but absent in high-income groups. Income-related inequalities in the prevalence of psychological distress were greatest in midlife; for example, in men aged 45-54 years the odds ratio of receiving psychiatric medication in the lowest income group compared with the highest was 7.50 [95% confidence interval (CI) 4.24-13.27] and in women aged 45-54 years the odds ratio of reporting mental illness was 10.25 (95% CI 6.16-17.05). An increased prevalence of psychological distress, common mental disorder diagnoses and treatment in midlife is not a universal phenomenon but is found only in those in low-income households. This implies the phenomenon is not inevitable but is potentially manageable or preventable.

  6. Extrasolar Planet Transits Observed at Kitt Peak National Observatory

    Science.gov (United States)

    Sada, Pedro V.; Deming, Drake; Jennings, Donald E.; Jackson, Brian k.; Hamilton, Catrina M.; Fraine, Jonathan; Peterson, Steven W.; Haase, Flynn; Bays, Kevin; Lunsford, Allen; O'Gorman, Eamon

    2012-03-01

    We obtained J-, H-, and JH-band photometry of known extrasolar planet transiting systems at the 2.1 m Kitt Peak National Observatory Telescope using the FLAMINGOS infrared camera between 2008 October and 2011 October. From the derived light curves we have extracted the midtransit times, transit depths and transit durations for these events. The precise midtransit times obtained help improve the orbital periods and also constrain transit-time variations of the systems. For most cases the published system parameters successfully accounted for our observed light curves, but in some instances we derive improved planetary radii and orbital periods. We complemented our 2.1 m infrared observations using CCD z‧-band and B-band photometry (plus two Hα filter observations) obtained with the Kitt Peak Visitor Center Telescope, and with four H-band transits observed in 2007 October with the NSO’s 1.6 m McMath-Pierce Solar Telescope. The principal highlights of our results are (1) Our ensemble of J-band planetary radii agree with optical radii, with the best-fit relation being (Rp/R∗)J = 0.0017 + 0.979(Rp/R∗)vis. (2) We observe starspot crossings during the transit of WASP-11/HAT-P-10. (3) We detect starspot crossings by HAT-P-11b (Kepler-3b), thus confirming that the magnetic evolution of the stellar active regions can be monitored even after the Kepler mission has ended. (4) We confirm a grazing transit for HAT-P-27/WASP-40. In total, we present 57 individual transits of 32 known exoplanet systems.

  7. The Crystal Zero Degree Detector at BESIII

    Science.gov (United States)

    Koch, L.; Denig, A.; Drexler, P.; Garillon, B.; Johansson, T.; Kühn, W.; Lange, S.; Lauth, W.; Liang, Y.; Marciniewski, P.; Rathmann, T.; Redmer, C.

    2017-07-01

    The BESIII experiment at the BEPCII electron positron collider at IHEP (Beijing) is collecting data in the charm-τ mass region. Electron positron collisions are a very well suited environment for the study of initial state radiation (ISR). However, the photons from ISR are strongly peaked towards small polar angles and are currently detected with limited efficiency. In order to increase the detection efficiency of ISR photons, we are developing small-size calorimeters to be placed in the very forward and backward regions. Each detector will consist of two 4×3 arrays of 1×1×14 cm3 LYSO crystals. A 1 cm gap separating each of the two arrays will reduce the contamination from background at very low angles. The scintillation light will be collected by silicon photomultipliers (SiPMs). The expected event rate in the MHz range requires flash ADCs recording the preamplified SiPM outputs.The digitized waveforms will be analyzed in realtime yielding data reduction and pile-up detection. This high bandwidth data stream will be transmitted via optical fibers to FPGA-based hardware performing sub-event building, buffering, and event correlation with the BESIII trigger. The sub-events with a corresponding trigger will be sent to the BESIII event builder via TCP/IP. A single crystal equipped with a SiPM was instrumented as a prototype detector. Tests with radioactive sources were performed successfully.

  8. Introducing uncertainty analysis of nucleation and crystal growth models in Process Analytical Technology (PAT) system design of crystallization processes.

    Science.gov (United States)

    Samad, Noor Asma Fazli Abdul; Sin, Gürkan; Gernaey, Krist V; Gani, Rafiqul

    2013-11-01

    This paper presents the application of uncertainty and sensitivity analysis as part of a systematic model-based process monitoring and control (PAT) system design framework for crystallization processes. For the uncertainty analysis, the Monte Carlo procedure is used to propagate input uncertainty, while for sensitivity analysis, global methods including the standardized regression coefficients (SRC) and Morris screening are used to identify the most significant parameters. The potassium dihydrogen phosphate (KDP) crystallization process is used as a case study, both in open-loop and closed-loop operation. In the uncertainty analysis, the impact on the predicted output of uncertain parameters related to the nucleation and the crystal growth model has been investigated for both a one- and two-dimensional crystal size distribution (CSD). The open-loop results show that the input uncertainties lead to significant uncertainties on the CSD, with appearance of a secondary peak due to secondary nucleation for both cases. The sensitivity analysis indicated that the most important parameters affecting the CSDs are nucleation order and growth order constants. In the proposed PAT system design (closed-loop), the target CSD variability was successfully reduced compared to the open-loop case, also when considering uncertainty in nucleation and crystal growth model parameters. The latter forms a strong indication of the robustness of the proposed PAT system design in achieving the target CSD and encourages its transfer to full-scale implementation. Copyright © 2013 Elsevier B.V. All rights reserved.

  9. Couette-Taylor crystallizer: Effective control of crystal size distribution and recovery of L-lysine in cooling crystallization

    Science.gov (United States)

    Nguyen, Anh-Tuan; Yu, Taekyung; Kim, Woo-Sik

    2017-07-01

    A Couette-Taylor crystallizer is developed to enhance the L-Lysine crystal size distribution and recovery in the case of continuous cooling crystallization. When using the proposed Couette-Taylor (CT) crystallizer, the size distribution and crystal product recovery were much narrower and higher, respectively, than those from a conventional stirred tank (ST) crystallizer. Here, the coefficient of the size distribution for the crystal product from the CT crystallizer was only 0.45, while it was 0.78 in the case of the conventional ST crystallizer at an agitation speed of 700 rpm, mean residence time of 20 min, and feed concentration of 900 (g/L). Furthermore, when using the CT crystallizer, the crystal product recovery was remarkably enhanced up to 100%wt with a mean residence time of only 20 min, while it required a mean residence time of at least 60 min when using the conventional ST crystallizer. This result indicates that the CT crystallizer was much more effective than the conventional ST crystallizer in terms of controlling a narrower size distribution and achieving a 100%wt L-lysine crystal product recovery from continuous cooling crystallization. The advantage of the CT crystallizer over the conventional ST crystallizer was explained based on the higher energy dissipation of the Taylor vortex flow and larger surface area for heat transfer of the CT crystallizer. Here, the energy dissipation of the Taylor vortex flow in the CT crystallizer was 13.6 times higher than that of the random fluid motion in the conventional ST crystallizer, while the surface area per unit volume for heat transfer of the CT crystallizer was 8.0 times higher than that of the conventional ST crystallizer. As a result, the mixing condition and heat transfer of the CT crystallizer were much more effective than those of the conventional ST crystallizer for the cooling crystallization of L-lysine, thereby enhancing the L-lysine crystal size distribution and product recovery.

  10. Photonic crystal optofluidic biolaser

    Science.gov (United States)

    Mozaffari, Mohammad Hazhir; Ebnali-Heidari, Majid; Abaeiani, Gholamreza; Moravvej-Farshi, Mohammad Kazem

    2017-09-01

    Optofluidic biolasers are recently being considered in bioanalytical applications due to their advantages over the conventional biosensing methods Exploiting a photonic crystal slab with selectively dye-infiltrated air holes, we propose a new optofluidic heterostructure biolaser, with a power conversion efficiency of 25% and the spectral linewidth of 0.24 nm. Simulations show that in addition to these satisfactory lasing characteristics, the proposed lab-on-a-chip biolaser is highly sensitive to the minute biological changes that may occur in its cavity and can detect a single virus with a radius as small as 13 nm.

  11. Between Smoke and Crystal

    DEFF Research Database (Denmark)

    Morsing, Mette; Christensen, Lars Thøger; Thyssen, Ole

    Responsible corporate behavior is not defined once and for all. Rather it develops as society and organizations interact, learn and change. It has convincingly been argued that in the area of CSR, there is a particular need for organizations to keep the definition of CSR open and inclusive to new...... between image and substance and most importantly it is a balancing act in which ”image” and public relations may drive organizations to improved “substance”. With reference to Odysseus, we label this a balancing act between the Scylla of crystal and the Charybdis of smoke....

  12. Crystal structure of cafenstrole

    Directory of Open Access Journals (Sweden)

    Gihaeng Kang

    2015-08-01

    Full Text Available The title compound (systematic name: N,N-diethyl-3-mesitylsulfonyl-1H-1,2,4-triazole-1-carboxamide, C16H22N4O3S, is a triazole herbicide. The dihedral angle between the planes of the triazole and benzene ring planes is 88.14 (10°. In the crystal, C—H...O hydrogen bonds and weak C—H...π interactions link adjacent molecules, forming one-dimensional chains along the a axis.

  13. Crystal structure prediction supported with diffraction data

    Science.gov (United States)

    Tsujimoto, Naoto; Adachi, Daiki; Todo, Synge; Akashi, Ryosuke; Tsuneyuki, Shinji

    Atomistic computer simulation is of growing importance in the study of unidentified crystals, although prediction or determination of complicated structure is still a challenging problem due to its many degrees of freedom. Here we propose to utilize experimentally available data of powder diffraction to support and accelerate the structure simulation. In so-called direct-space methods for structure determination from powder diffraction, simplified interatomic potential energy or some other physical constraints are often used in combination with the cost function defined by diffraction data. On the other hand, we formulate a cost function called ``crystallinity'' to support simulation with accurate interatomic potential energy. Since the crystallinity here is defined as the sum of the diffraction intensities only at the peak positions detected in experiments, this method is applicable to low-quality diffraction data such as those obtained at high pressures. We apply this method to well-known polymorphs of SiO2 with up to 96 atoms in the simulation cell to find that it reproduces the correct structures efficiently with information of a very limited number of diffraction peaks.

  14. Inorganic Crystal Structure Database (ICSD)

    Science.gov (United States)

    SRD 84 FIZ/NIST Inorganic Crystal Structure Database (ICSD) (PC database for purchase)   The Inorganic Crystal Structure Database (ICSD) is produced cooperatively by the Fachinformationszentrum Karlsruhe(FIZ) and the National Institute of Standards and Technology (NIST). The ICSD is a comprehensive collection of crystal structure data of inorganic compounds containing more than 140,000 entries and covering the literature from 1915 to the present.

  15. Amorphous chalcogenides as random octahedrally bonded solids: I. Implications for the first sharp diffraction peak, photodarkening, and Boson peak

    Science.gov (United States)

    Lukyanov, Alexey; Lubchenko, Vassiliy

    2017-09-01

    We develop a computationally efficient algorithm for generating high-quality structures for amorphous materials exhibiting distorted octahedral coordination. The computationally costly step of equilibrating the simulated melt is relegated to a much more efficient procedure, viz., generation of a random close-packed structure, which is subsequently used to generate parent structures for octahedrally bonded amorphous solids. The sites of the so-obtained lattice are populated by atoms and vacancies according to the desired stoichiometry while allowing one to control the number of homo-nuclear and hetero-nuclear bonds and, hence, effects of the mixing entropy. The resulting parent structure is geometrically optimized using quantum-chemical force fields; by varying the extent of geometric optimization of the parent structure, one can partially control the degree of octahedrality in local coordination and the strength of secondary bonding. The present methodology is applied to the archetypal chalcogenide alloys AsxSe1-x. We find that local coordination in these alloys interpolates between octahedral and tetrahedral bonding but in a non-obvious way; it exhibits bonding motifs that are not characteristic of either extreme. We consistently recover the first sharp diffraction peak (FSDP) in our structures and argue that the corresponding mid-range order stems from the charge density wave formed by regions housing covalent and weak, secondary interactions. The number of secondary interactions is determined by a delicate interplay between octahedrality and tetrahedrality in the covalent bonding; many of these interactions are homonuclear. The present results are consistent with the experimentally observed dependence of the FSDP on arsenic content, pressure, and temperature and its correlation with photodarkening and the Boson peak. They also suggest that the position of the FSDP can be used to infer the effective particle size relevant for the configurational equilibration in

  16. Crystallization and Polymorphism of Felodipine

    DEFF Research Database (Denmark)

    Surov, A. O.; Solanko, K. A.; Bond, A. D.

    2012-01-01

    . The crystal structures of the new forms III and IV were determined using single-crystal X-ray diffraction. Forms I, II, and III were obtained in bulk form and characterized by a variety of analytical methods, including thermal analysis, solution calorimetry, intrinsic dissolution rate measurement......, and solubility measurement. Form IV could be obtained only as a few isolated single crystals, and its crystallization could not be reproduced. On the basis of the measured thermochemical data and solubility studies, form I appears to be the thermodynamically most stable phase at ambient conditions, although...

  17. Preventing Crystal Agglomeration of Pharmaceutical Crystals Using Temperature Cycling and a Novel Membrane Crystallization Procedure for Seed Crystal Generation

    Directory of Open Access Journals (Sweden)

    Elena Simone

    2018-01-01

    Full Text Available In this work, a novel membrane crystallization system was used to crystallize micro-sized seeds of piroxicam monohydrate by reverse antisolvent addition. Membrane crystallization seeds were compared with seeds produced by conventional antisolvent addition and polymorphic transformation of a fine powdered sample of piroxicam form I in water. The membrane crystallization process allowed for a consistent production of pure monohydrate crystals with narrow size distribution and without significant agglomeration. The seeds were grown in 350 g of 20:80 w/w acetone-water mixture. Different seeding loads were tested and temperature cycling was applied in order to avoid agglomeration of the growing crystals during the process. Focused beam reflectance measurement (FBRM; and particle vision and measurement (PVM were used to monitor crystal growth; nucleation and agglomeration during the seeded experiments. Furthermore; Raman spectroscopy was used to monitor solute concentration and estimate the overall yield of the process. Membrane crystallization was proved to be the most convenient and consistent method to produce seeds of highly agglomerating compounds; which can be grown via cooling crystallization and temperature cycling.

  18. Acetate Ligands Determine the Crystal Structure of CdSe Nanoplatelets - a Density Functional Theory study

    NARCIS (Netherlands)

    Koster, R.S.; Fang, C.M.; van Blaaderen, A.; Dijkstra, M.; van Huis, M.A.

    2016-01-01

    Cadmium selenide (CdSe) nanoplatelets of a few atomic layers thick exhibit extremely sharp photoluminescence peaks and are synthesized in the zinc blende crystal structure, whereas the most stable bulk polymorph of CdSe is the wurtzite structure. These platelets can be synthesized very

  19. Defect characterization of Ga4Se3S layered single crystals by ...

    Indian Academy of Sciences (India)

    Trapping centres in undoped Ga 4 Se 3 S single crystals grown by Bridgman method were characterized for the first time by thermoluminescence (TL) measurements carried out in the low temperature range of 15−300 K. After illuminating the sample with blue light (∼470 nm) at 15 K, TL glow curve exhibited one peak ...

  20. Microcontroller-based servo for two-crystal X-ray monochromators.

    Science.gov (United States)

    Siddons, D P

    1998-05-01

    Microcontrollers have become increasingly easy to incorporate into instruments as the architectures and support tools have developed. The PIC series is particularly easy to use, and this paper describes a controller used to stabilize the output of a two-crystal X-ray monochromator at a given offset from its peak intensity position, as such monochromators are generally used.

  1. Molecular Assembly of Hemin on Single-Crystal Au(111)-electrode Surfaces

    DEFF Research Database (Denmark)

    Zhang, Ling; Ulstrup, Jens; Zhang, Jingdong

    -defined single-crystal Au(111)-electrodesurfaces using electrochemistry combined with scanning tunnelling microscopy under electrochemical control. Hemin gives two voltammetric peaks assigned to adsorbed monomers and dimmers (Fig. 1A). In situ STM shows that hemin self-assembles in ordered monolayers through non...

  2. Photonic Crystal Optical Tweezers

    CERN Document Server

    Wilson, Benjamin K; Bachar, Stephanie; Knouf, Emily; Bendoraite, Ausra; Tewari, Muneesh; Pun, Suzie H; Lin, Lih Y

    2009-01-01

    Non-invasive optical manipulation of particles has emerged as a powerful and versatile tool for biological study and nanotechnology. In particular, trapping and rotation of cells, cell nuclei and sub-micron particles enables unique functionality for various applications such as tissue engineering, cancer research and nanofabrication. We propose and demonstrate a purely optical approach to rotate and align particles using the interaction of polarized light with photonic crystal nanostructures to generate enhanced trapping force. With a weakly focused laser beam we observed efficient trapping and transportation of polystyrene beads with sizes ranging from 10 um down to 190 nm as well as cancer cell nuclei. In addition, we demonstrated alignment of non-spherical particles using a 1-D photonic crystal structure. Bacterial cells were trapped, rotated and aligned with optical intensity as low as 17 uW/um^2. Finite-difference time domain (FDTD) simulations of the optical near-field and far-field above the photonic c...

  3. Microplasticity of silicon crystals

    Science.gov (United States)

    Drozhzhin, A. I.; Sidel'Nikov, I. V.; Antipov, S. A.; Sedykh, N. K.

    1980-05-01

    The low-frequency (˜1 Hz) internal friction (Q-1) method was used to study the microplasticity of silicon whisker crystals grown by the method of chemical gas-transport reactions in a closed ampoule. A study was made of p-type crystals with the growth axis , 1 60 μ in diameter, working length 1 3 mm, both in the original state and after plastic (γ ˜ 1%) deformtion by torsion. The temperature and amplitude dependences of Q-1 were studied in ˜5·10-5 torr vacuum. The amplitude of alternating vibrations was within the range ˜10-5 10-3 and the axial stresses were ˜106 107 N/m2. The experimental results led to the conclusion that the microplasticity of undeformed silicon whiskers was due to heterogeneous nucleation of dislocations in stress concentration regions near surface defects, assisted by thermal fluctuations. In deformed whiskers the microplasticity was attributed to the nucleation and motion along dislocations of single and double thermal kinks in accordance with the Seeger model.

  4. Electron spectroscopy of crystals

    CERN Document Server

    Nemoshkalenko, V V

    1979-01-01

    This book is conceived as a monograph, and represents an up-to-date collection of information concerning the use of the method of X-ray photoelectron spec­ troscopy in the study of the electron structure of crystals, as well as a personal interpretation of the subject by the authors. In a natural way, the book starts in Chapter 1 with a recapitulation of the fundamentals of the method, basic relations, principles of operation, and a com­ parative presentation of the characteristics and performances of the most com­ monly used ESCA instruments (from the classical ones-Varian, McPherson, Hewlett Packard, and IEEE-up to the latest model developed by Professor Siegbahn in Uppsala), and continues with a discussion of some of the difficult problems the experimentalist must face such as calibration of spectra, prepara­ tion of samples, and evaluation of the escape depth of electrons. The second chapter is devoted to the theory of photoemission from crystal­ line solids. A discussion of the methods of Hartree-Fo...

  5. Tunable Topological Phononic Crystals

    KAUST Repository

    Chen, Ze-Guo

    2016-05-27

    Topological insulators first observed in electronic systems have inspired many analogues in photonic and phononic crystals in which remarkable one-way propagation edge states are supported by topologically nontrivial band gaps. Such band gaps can be achieved by breaking the time-reversal symmetry to lift the degeneracy associated with Dirac cones at the corners of the Brillouin zone. Here, we report on our construction of a phononic crystal exhibiting a Dirac-like cone in the Brillouin zone center. We demonstrate that simultaneously breaking the time-reversal symmetry and altering the geometric size of the unit cell result in a topological transition that we verify by the Chern number calculation and edge-mode analysis. We develop a complete model based on the tight binding to uncover the physical mechanisms of the topological transition. Both the model and numerical simulations show that the topology of the band gap is tunable by varying both the velocity field and the geometric size; such tunability may dramatically enrich the design and use of acoustic topological insulators.

  6. Decreased peak expiratory flow in pediatric passive smokers

    Directory of Open Access Journals (Sweden)

    Fitri Yanti

    2011-08-01

    Full Text Available Background Indonesia ranks fifth among countries with the highest aggregate levels of tobacco consumption in the world. Infants and children exposed to environmental tobacco smoke have increased rates of asthma, respiratory and ear infections, as well as reduced lung function. The effects of tobacco smoke exposure on lung function in children have been reported to be dependent on the source of smoke and the length and dose of exposure. Lung function may also be affected by a child’s gender and asthma status. Objective To compare peak expiratory flow (PEF in pediatric passive smokers to that of children not exposed to second hand smoke, and to define factors that may affect PEF in passive smokers. Methods In August 2009 we conducted a cross-sectional study at an elementary school in the Langkat district. Subjects were aged 6 to 12 years, and divided into two groups: passive smokers and those not exposed to secondhand smoke. Subjects’ PEFs were measured with a Mini-Wright peak flow meter. Measurements were performed in triplicate with the highest value recorded as the PEF. Demographic data including age, sex, weight, height, family income, parental education levels and occupations were obtained through questionnaires. Results Of the 170 participants, 100 were passive smokers and 70 were not exposed to secondhand smoke. Age distribution, weight and height were similar in both groups. We observed a significant difference in PEFs between the group of passive smokers and the group not exposed to secondhand smoke, 211.3 L/minute (SD 61.08 and 242.7 L/minute (SD 77.09, respectively (P < 0.005. The number of years of exposure to smoke (P = 0.079 and the number of cigarettes smoked daily in the household (P = 0.098 did not significantly influence PEF. Conclusion The PEF in pediatric passive smokers was significantly lower than that of children not exposed to secondhand smoke. PEF in passive smokers was not influenced by the number of years of smoke

  7. Structural, optical and dielectric studies of lithium sulphate monohydrate single crystals

    Directory of Open Access Journals (Sweden)

    Najar F.A.

    2017-02-01

    Full Text Available Optical, dielectric, and thermal properties of lithium sulphate monohydrate crystals grown by slow evaporation method have been studied. The crystal structure was resolved by direct methods using single crystal X-ray diffraction data collected at room temperature and refined by full-matrix least-squares procedures to a final R-value of 0.0174. Plasma energy, Penn gap, Fermi energy and electronic polarizability of the grown crystal were calculated from single crystal XRD data. The electronic polarizability of lithium sulfate monohydrate was also calculated and compared with the theoretical data using Clausius-Mossotti equation. Optical band gap calculated from optical data for the grown crystal is 4.49 eV. Fourier Transform Infrared Spectroscopy study confirmed the presence of water in the crystal structure. The AC conductivity, dielectric constant and dielectric loss of the grown crystal were systemically investigated, showing a peak at about 130 °C which could be attributed to the water molecules in the crystal structure. The anomalous dielectric properties shown by the crystal have been correlated with its thermal behavior. The title crystal obeys Jonscher’s power law relation; σ(ω = σo+ Aωs, with temperature dependent exponent s < 1. The activation energy calculated for the material is 0.24 eV and suggests protonic conduction by hopping mechanism in addition to cationic conduction by lithium ions. The micro-indentation study was also carried out which revealed that the crystal belongs to a category of soft materials.

  8. New AIG Method of Growing Alkali Halide Crystals and Potential Application to CZT

    Science.gov (United States)

    Gleyzer, A.; Rhodes, E.

    2002-10-01

    The new AIG (Advance Interface Growth) method has been successfully applied to alkali halide scintillation crystals at PhotoPeak, Inc. for the last four years. It produces single, stress-free crystals having a low level of defects and has resulted in increasing the yield of usable CsI(Tl) crystals to 75-85%. Essentially it is a low gradient method but has the capability to adapt the gradient to that needed by an individual crystal for the most successful growth. High quality crystals have been supplied to national laboratories and the nuclear medicine market. For example, a blank CsI(Tl) crystal 2 in diameter and 2 in length was produced having a measured energy resolution of 6.5% at 662 keV on a 2 -diameter PMT having a standard blue bialkali photocathode. This far exceeds the best resolution, 8.5-9.5%, obtained for CsI(Tl) crystals grown by the conventional Bridgman method. It is expected that this method can be successfully applied to grow high quality CZT crystals with substantially higher yield, 25-35%, than the presently existing 5-10%. The reasons for the expected improved yield of CZT crystals are that the phase diagram of CZT material has a narrow range of stability and CZT crystals should benefit from growth in a low gradient environment. Since the AIG method does not involve any moving parts, the temperature control and stability are much higher than for the conventional Bridgman method. The experience with CsI crystals indicates that imperfections like twinning, sparks, and multiplicities can be substantially reduced or even eliminated in CZT crystals. The expected higher yield and improved spectroscopic quality of CZT should allow many commercial applications to become a reality.

  9. Determinant factors of peak treadmill speed in physically active men.

    Science.gov (United States)

    Alves Pasqua, Leonardo; Damasceno, Mayara V; Bueno, Salomão; Zagatto, Alessandro M; DE Araújo, Gustavo G; Lima-Silva, Adriano E; Bertuzzi, Rômulo

    2016-11-30

    The aim of the present study was to determine whether physiological factors and maximal dynamic strength are able to determine the peak treadmill speed (PTS) in physically active individuals. One hundred and fifty physically active healthy males voluntarily visit the laboratory on three separate occasions and underwent the following activities: first visit: IPAQ (short version), anthropometric measurements, and a maximal incremental test performed for physiological variables (maximal oxygen uptake ( ) and respiratory compensation point (RCP); second visit: constant speed test for running economy (RE) measurement, and familiarization with the maximum dynamic strength (1RM) test in the leg press exercise; third visit: 1RM test. The stepwise multiple regression model selected four independent variables to predict PTS (RCP, , RE, and 1RM). RCP explained 59% (p < 0.001) of variance in PTS, whereas , RE and 1RM accounted for additional 8% (p < 0.001), 4% (p < 0.001), and 1.4% (p = 0.038), respectively. In conclusion, the results of the present study demonstrate that PTS, an important predictor of endurance performance, is determined by both physiological (i.e., RCP, and RE) and muscular (1RM) parameters in healthy active individuals. These results demonstrate that, during a physical evaluation, PTS is able to represent physiological and muscular parameters of physically active individuals. This has the advantage during aerobic fitness evaluations of not requiring expensive equipment and specialized software.

  10. Individual Alpha Peak Frequency in Ice Hockey Shooting Performance

    Directory of Open Access Journals (Sweden)

    Sommer Christie

    2017-05-01

    Full Text Available There are several important inter- and intra-individual variations in individual alpha peak frequency (IAPF in the cognitive domain. The rationale for the present study was to extend the research on IAPF in the cognitive domain to IAPF in the sport domain. Specifically, the purpose of the present study was twofold: (a to explore whether baseline IAPF is related to performance in an ice hockey shooting task and (b to explore whether a shooting task has an effect on IAPF variability. The present investigation is one of the first studies to examine links between IAPF and sport performance. Study results did not show significant changes in IAPF when comparing baseline IAPF and pre- to post-task IAPF across three performance levels. The findings support previous literature in the cognitive domain suggesting that IAPF is a stable neurophysiological marker. Future research should consider the following methodological suggestions: (a measuring IAPF during sport performance instead of at a resting state, (b changing the pre-performance resting baseline instructions to take into account sport-specific mental preparation, (c exploring an expert-novice paradigm to accentuate performance ability differences between groups (d comparing tasks with different levels of complexity, and (e analyzing the possible correlation between IAPF and performance on different days.

  11. Textural Poaching Twin Peaks: The Audrey Horne Sweater Girl GIFs

    Directory of Open Access Journals (Sweden)

    Jennifer Gillan

    2016-12-01

    Full Text Available This article aims to widen the lens of analysis of participatory culture inspired by long-arc serials like Twin Peaks. It considers GIF creation as a form of textural poaching, a new reception practice involving skimming off and repurposing top-of-the-mind content: the most arresting elements of costuming, set design, and dialogue. This behavior has become more popular as more series rely on textural storytelling and are filled with moments of excess that feel separate from the story. After an introduction to GIFs and GIF creation, it contrasts the impression of the character and series conveyed by Audrey Horne GIFs and the actual dynamics in the “Audrey’s Dance” scene. It establishes that Audrey’s look is most visually aligned with the Sweater Girl type, but as an allusive characterization it creates excess and calls attention to itself. Part of the “cool pop” reputation of the series may stem from the wider circulation of iconic moments of excess especially given that the GIFs detach the images from the series’ uneven storytelling and its challenging surrealist sensibility.

  12. Individual Alpha Peak Frequency in Ice Hockey Shooting Performance.

    Science.gov (United States)

    Christie, Sommer; di Fronso, Selenia; Bertollo, Maurizio; Werthner, Penny

    2017-01-01

    There are several important inter- and intra-individual variations in individual alpha peak frequency (IAPF) in the cognitive domain. The rationale for the present study was to extend the research on IAPF in the cognitive domain to IAPF in the sport domain. Specifically, the purpose of the present study was twofold: (a) to explore whether baseline IAPF is related to performance in an ice hockey shooting task and (b) to explore whether a shooting task has an effect on IAPF variability. The present investigation is one of the first studies to examine links between IAPF and sport performance. Study results did not show significant changes in IAPF when comparing baseline IAPF and pre- to post-task IAPF across three performance levels. The findings support previous literature in the cognitive domain suggesting that IAPF is a stable neurophysiological marker. Future research should consider the following methodological suggestions: (a) measuring IAPF during sport performance instead of at a resting state, (b) changing the pre-performance resting baseline instructions to take into account sport-specific mental preparation, (c) exploring an expert-novice paradigm to accentuate performance ability differences between groups (d) comparing tasks with different levels of complexity, and (e) analyzing the possible correlation between IAPF and performance on different days.

  13. Conciliating SUSY with the Z-peaked excess

    Directory of Open Access Journals (Sweden)

    Mitsou Vasiliki A.

    2016-01-01

    Full Text Available The ATLAS experiment observed an excess at the 3σ level in the channel of Z boson, jets and high missing transverse momentum in the full 2012 dataset at 8 TeV while searching for SUSY. The question arises whether the abundance and the kinematical features of this excess are compatible with the yet unconstrained supersymmetric realm, respecting at the same time the measured Higgs boson properties and dark matter density. By trying to explain this signal with SUSY we find that only relatively light gluinos together with a heavy neutralino NLSP decaying predominantly to a Z boson plus a light gravitino could reproduce the excess. We construct an explicit general gauge mediation model able to match the observed signal. More sophisticated models could also reproduce the signal, as long as it features light gluinos, or heavy particles with a strong production cross section, producing at least one Z boson in its decay chain. The implications of our findings for the Run II at LHC with the scaling on the Z peak, as well as for the direct search of gluinos and other SUSY particles, are also discussed.

  14. Ferroelectric-like transition on a hygroscopic barium thiourea chloride single crystal

    Science.gov (United States)

    Raju, S.; Muralidharan, R.; Krishnan, H.

    2015-04-01

    Barium thiourea chloride (BTC) single crystals were grown by slow evaporation of aqueous solution. The X-ray and spectral studies confirmed the formation of the title compound. Thermal studies carried out using differential scanning calorimetry (DSC) showed the presence of both the adsorbed and absorbed water in the grown crystal, which can be identified through the peaks around temperatures 80°C and 130°C. The dielectric constant against temperature curve for different frequencies showed concomitant anomaly around the temperature region of 80°C to 120°C similar to a ferroelectric phase transition. We infer that this peak is due to the removal of water and not due to ferroelectric transition and care should be taken while measuring and interpreting dielectric properties of similar hygroscopic crystals containing volatile compounds.

  15. [Study of scintillating luminescence spectra of lead tungstate scintillation crystal doped with ions].

    Science.gov (United States)

    Wan, You-bao; Wu, Yu-rong; Zhang, Jian-xin; Yang, Pei-zhi; Xiao, Lin-rong; Yang, Hui

    2009-09-01

    The light yield of the as-grown PbWO4, annealed PbWO4 and BaF2:PbWO4 crystals were raised by utilizing our improved crystal growth instrument and technique. Their scintillating properties including transmittance, decay time and light yield were studied. Results reveal that the scintillating performances of the crystals were improved evidently by using the crystal annealing technique and the ions doping technique, especially the negative ions doping technique. The influence results of the two techniques are different. The ions doping technique raises their transmittance intensity in the whole measuring wavelength range. But the influence of annealing PbWO4 crystal on their transmittance is complicated. It improves its transmittance intensity at the wavelength above 360 nm, but weakens the transmittance intensity of the annealed PbWO4 crystal in the wavelength range from 320 to 360 nm. These phenomena should be related to the crystal defects which have absorption peaks in this wavelength range, especially for V(Pb)3+ defect which has characterized absorption peaks in this wavelength range. Also, the absorption of the defects influences the character of the decay time of these crystals. The big defect concentration relates to the short decay time. It should be mentioned that the ions doping technique reduces the defect content in the crystal, which is beneficial to the high transmittance intensity but induces slightly longer decay time than that of as-grown crystal and well annealed PbWO4 crystal. Also, the ions doping technique of the F- ion doped crystal leads to high light yield. The annealing technique and ions doping technique improve the light yield of crystals. The light yield of BaF2:PbWO4 reaches 65 p.e./MeV, which is near to the requirement of PET. The good result is related to the degeneration of the [WO4]2- tetrahedron induced by the F- occupying the O2- site in the crystal cell.

  16. Annual Peak-Flow and Peak Dam-Pool-Elevation Frequency Characteristics of Selected Dry Dams in the Great Miami River Basin, Ohio

    Science.gov (United States)

    Koltun, G.F.

    2009-01-01

    This report describes the results of a study to determine frequency characteristics of post-regulation annual peak flows at streamflow-gaging stations near the Taylorsville, Huffman, and Germantown dry dams in the Miami Conservancy District flood-protection system (southwestern Ohio), and of annual peak elevations of the corresponding dam pools. Log-Pearson Type III distributions were fit to annual peak flow values for the period 1921 or 1922 through 2007 (the most recent year of published peak flow values at the time of this analysis) and annual peak dam-pool storage values for the period 1922- 2008 to determine peaks with recurrence intervals of 2, 5, 10, 25, 50, 100, 200, and 500 years. Once storages had been estimated for the various recurrence intervals, corresponding dam-pool elevations were determined from elevation-storage ratings provided by the Miami Conservancy District.

  17. Photonic-crystal fibers gyroscope

    Directory of Open Access Journals (Sweden)

    Ali Muse Haider

    2015-01-01

    Full Text Available In this paper we proposed to use of a photonic crystal fiber with an inner hollow defect. The use of such fibers is not affected by a material medium on the propagation of optical radiation. Photonic crystal fibers present special properties and capabilities that lead to an outstanding potential for sensing applications

  18. Liquid Crystals for Laser Applications

    Science.gov (United States)

    1992-07-01

    Structures, Leonard Hill, Philadelphia, PA, 1984. 5. Gray, G. W., Ed., Thermotropic Liquid Crystals, Series (Critical Reports on Applied Chemistry, Vol. 22...crystal, Phys. Rev. A, 29, 297-307, 1984. 331. Khyzhniak, A., Odoulov, S., Reznikov, Yu., and Soskin , M., Dynamic hologram recording and phase conjugation

  19. Handbook of nonlinear optical crystals

    CERN Document Server

    Dmitriev, Valentin G; Nikogosyan, David N

    1991-01-01

    This Handbook of Nonlinear Optical Crystals provides a complete description of the properties and applications of nonlinear crystals In addition, it presents the most important equations for calculating the main parameters of nonlinear frequency converters This comprehensive reference work will be of great value to all scientists and engineers working in nonlinear optics, quantum electronics and laser physics

  20. Photoelastic sphenoscopic analysis of crystals

    Energy Technology Data Exchange (ETDEWEB)

    Montalto, L. [DIISM, Dip. Di Ingegneria Industriale e Scienze Matematiche—Università Politecnica delle Marche, Ancona (Italy); SIMAU, Dip. Di Scienze e Ingegneria della Materia, dell’ambiente ed Urbanistica—Università Politecnica delle Marche, Ancona (Italy); Rinaldi, D. [SIMAU, Dip. Di Scienze e Ingegneria della Materia, dell’ambiente ed Urbanistica—Università Politecnica delle Marche, Ancona (Italy); Scalise, L.; Paone, N. [DIISM, Dip. Di Ingegneria Industriale e Scienze Matematiche—Università Politecnica delle Marche, Ancona (Italy); Davì, F. [DICEA, Dip. Di Ingegneria Civile, Edile e Architettura—Università Politecnica delle Marche, Ancona (Italy)

    2016-01-15

    Birefringent crystals are at the basis of various devices used in many fields, from high energy physics to biomedical imaging for cancer detection. Since crystals are the main elements of those devices, a great attention is paid on their quality and properties. Here, we present a methodology for the photoelastic analysis of birefringent crystals, based on a modified polariscope. Polariscopes using conoscopic observation are used to evaluate crystals residual stresses in a precise but time consuming way; in our methodology, the light beam shape, which impinges on the crystal surface, has been changed from a solid cone (conoscopy) to a wedge (sphenoscopy). Since the polarized and coherent light is focused on a line rather than on a spot, this allows a faster analysis which leads to the observation, at a glance, of a spatial distribution of stress along a line. Three samples of lead tungstate crystals have been observed using this technique, and the obtained results are compared with the conoscopic observation. The samples have been tested both in unloaded condition and in a loaded configuration induced by means of a four points bending device, which allows to induce a known stress distribution in the crystal. The obtained results confirm, in a reliable manner, the sensitivity of the methodology to the crystal structure and stress.