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Sample records for high absorption rate

  1. Energy absorption at high strain rate of glass fiber reinforced mortars

    Directory of Open Access Journals (Sweden)

    Fenu Luigi

    2015-01-01

    Full Text Available In this paper, the dynamic behaviour of cement mortars reinforced with glass fibers was studied. The influence of the addition of glass fibers on energy absorption and tensile strength at high strain-rate was investigated. Static tests in compression, in tension and in bending were first performed. Dynamic tests by means of a Modified Hopkinson Bar were then carried out in order to investigate how glass fibers affected energy absorption and tensile strength at high strain-rate of the fiber reinforced mortar. The Dynamic Increase Factor (DIF was finally evaluated.

  2. Elementary reaction rate measurements at high temperatures by tunable-laser flash-absorption

    Energy Technology Data Exchange (ETDEWEB)

    Hessler, J.P. [Argonne National Laboratory, IL (United States)

    1993-12-01

    The major objective of this program is to measure thermal rate coefficients and branching ratios of elementary reactions. To perform these measurements, the authors constructed an ultrahigh-purity shock tube to generate temperatures between 1000 and 5500 K. The tunable-laser flash-absorption technique is used to measure the rate of change of the concentration of species which absorb below 50,000 cm{sup {minus}1} e.g.: OH, CH, and CH{sub 3}. This technique is being extended into the vacuum-ultraviolet spectral region where one can measure atomic species e.g.: H, D, C, O, and N; and diatomic species e.g.: O{sub 2}, CO, and OH.

  3. A Review on Level of Specific Absorption Rate Due to High Power Transmission Lines: Analysis toward Human Position Posture

    Directory of Open Access Journals (Sweden)

    Ghazali Z.

    2016-01-01

    Full Text Available The main contribution of this project is the development of a homogeneous model of a man to presents the specific absorption rate (SAR due to high power transmission line. As a low frequency application under high power transmission line of 50 Hz in electrical engineering, to studies the influence of human’s posture on specific absorption rate. This project designs two types of human body which one design uses most cylinder block and another design use brick block where both blocks have a different value of mesh cells. For each design has four types of posture are standing, sitting, arms up and arms out by using Computer Simulation Technology (CST Studio Software. This analysis does toward for four types of the human position postures because each posture has different value of specific absorption rate (SAR based on the size of the mesh cells of the design. Based on two designs of the human body, the lowest of the mesh cells value will reduce time to simulate SAR. For each posture has different value of SAR for each part of the human body because the whole human body has different types of tissues. Therefore, the CST studio software uses extremely to simulate the SAR value toward human position posture due to high power transmission line.

  4. High Repetition Rate and Frequency Stabilized Ho:YLF Laser for CO2 Differential Absorption Lidar

    Science.gov (United States)

    Bai, Yingxin; Yu, Jirong; Petros, M.; Petzar, Pau; Trieu, Bo; Lee, Hyung; Singh, U.

    2009-01-01

    High repetition rate operation of an injection seeded Ho:YLF laser has been demonstrated. For 1 kHz operation, the output pulse energy reaches 5.8mJ and the optical-to-optical efficiency is 39% when the pump power is 14.5W.

  5. Modifying the high rate algal pond light environment and its effects on light absorption and photosynthesis.

    Science.gov (United States)

    Sutherland, Donna L; Montemezzani, Valerio; Howard-Williams, Clive; Turnbull, Matthew H; Broady, Paul A; Craggs, Rupert J

    2015-03-01

    The combined use of high rate algal ponds (HRAPs) for wastewater treatment and commercial algal production is considered to be an economically viable option. However, microalgal photosynthesis and biomass productivity is constrained in HRAPs due to light limitation. This paper investigates how the light climate in the HRAP can be modified through changes in pond depth, hydraulic retention time (HRT) and light/dark turnover rate and how this impacts light absorption and utilisation by the microalgae. Wastewater treatment HRAPs were operated at three different pond depth and HRT during autumn. Light absorption by the microalgae was most affected by HRT, significantly decreasing with increasing HRT, due to increased internal self-shading. Photosynthetic performance (as defined by Pmax, Ek and α), significantly increased with increasing pond depth and decreasing HRT. Despite this, increasing pond depth and/or HRT, resulted in decreased pond light climate and overall integrated water column net oxygen production. However, increased light/dark turnover was able to compensate for this decrease, bringing the net oxygen production in line with shallower ponds operated at shorter HRT. On overcast days, modelled daily net photosynthesis significantly increased with increased light/dark turnover, however, on clear days such increased turnover did not enhance photosynthesis. This study has showed that light absorption and photosynthetic performance of wastewater microalgae can be modified through changes to pond depth, HRT and light/dark turnover.

  6. A new heating strategy in electrothermal atomic absorption spectrometry for better absorbance-time curves at high atomization rate

    Energy Technology Data Exchange (ETDEWEB)

    Torsi, Giancarlo [Department of Chemistry G. Ciamician, University of Bologna, Via F. Selmi 2, 40126 Bologna (Italy)]. E-mail: giancarlo.torsi@unibo.it; Zattoni, Andrea [Department of Chemistry G. Ciamician, University of Bologna, Via F. Selmi 2, 40126 Bologna (Italy); Locatelli, Clinio [Department of Chemistry G. Ciamician, University of Bologna, Via F. Selmi 2, 40126 Bologna (Italy); Valcher, Sergio [Department of Chemistry G. Ciamician, University of Bologna, Via F. Selmi 2, 40126 Bologna (Italy)

    2005-03-31

    The results previously obtained by using fast heating in electrothermal atomic absorption spectrometry are considerably improved by using a new heating sequence which can be summarized as transverse-longitudinal heating mode. The absorbance vs. time curves, obtained with the new heating mode, follow almost perfectly a simple model in which only diffusion is considered as the force acting on the atomic vapor. From the fitting of the experimental absorbance vs. time data points with theoretical values, it is possible to calculate both the absorbance, when all atoms injected are assumed to be present, and their diffusion coefficient. Both values can be calculated by a simple software approach without the operator intervention. The asymptotic absorbance calculated in this way is the maximum absorbance physically obtainable and is the basis for standardless analysis.

  7. High optical absorption in graphene

    CERN Document Server

    Apell, S P; Hägglund, C

    2012-01-01

    A simple analysis is performed for the absorption properties of graphene; sandwiched between two media. For a proper choice of media and graphene doping/gating one can approach 50-100% absorption in the GHz-THz range for the one atom thick material. This absorption is controlled by a characteristic chemical potential which depends only on carrier life-time and the indexes of refraction of the dielectric embedding.

  8. Exercise, Insulin Absorption Rates, and Artificial Pancreas Control

    Science.gov (United States)

    Frank, Spencer; Hinshaw, Ling; Basu, Rita; Basu, Ananda; Szeri, Andrew J.

    2016-11-01

    Type 1 Diabetes is characterized by an inability of a person to endogenously produce the hormone insulin. Because of this, insulin must be injected - usually subcutaneously. The size of the injected dose and the rate at which the dose reaches the circulatory system have a profound effect on the ability to control glucose excursions, and therefore control of diabetes. However, insulin absorption rates via subcutaneous injection are variable and depend on a number of factors including tissue perfusion, physical activity (vasodilation, increased capillary throughput), and other tissue geometric and physical properties. Exercise may also have a sizeable effect on the rate of insulin absorption, which can potentially lead to dangerous glucose levels. Insulin-dosing algorithms, as implemented in an artificial pancreas controller, should account accurately for absorption rate variability and exercise effects on insulin absorption. The aforementioned factors affecting insulin absorption will be discussed within the context of both fluid mechanics and data driven modeling approaches.

  9. Microsaccade-rate indicates absorption by music listening.

    Science.gov (United States)

    Lange, Elke B; Zweck, Fabian; Sinn, Petra

    2017-08-05

    The power of music is a literary topos, which can be attributed to intense and personally significant experiences, one of them being the state of absorption. Such phenomenal states are difficult to grasp objectively. We investigated the state of musical absorption by using eye tracking. We utilized a load related definition of state absorption: multimodal resources are committed to create a unified representation of music. Resource allocation was measured indirectly by microsaccade rate, known to indicate cognitive processing load. We showed in Exp. 1 that microsaccade rate also indicates state absorption. Hence, there is cross-modal coupling between an auditory aesthetic experience and fixational eye movements. When removing the fixational stimulus in Exp. 2, saccades are no longer generated upon visual input and the cross-modal coupling disappeared. Results are interpreted in favor of the load hypothesis of microsaccade rate and against the assumption of general slowing by state absorption. Copyright © 2017. Published by Elsevier Inc.

  10. The absorption of carbon monoxide in COSORB solutions: absorption rate and capacity

    NARCIS (Netherlands)

    Hogendoorn, Kees; van Swaaij, Willibrordus Petrus Maria; Versteeg, Geert

    1995-01-01

    Absorption rate experiments and equilibrium experiments were carried out for the COSORB reaction at 300 K. The equilibrium data at 300 K could reasonably well be described with the following relation: [...] Determination of the kinetics and mechanism of a chemical reaction by means of absorption exp

  11. Soft Black Hole Absorption Rates as Conservation Laws

    CERN Document Server

    Avery, Steven G

    2016-01-01

    The absorption rate of low-energy, or soft, electromagnetic radiation by spherically symmetric black holes in arbitrary dimensions is shown to be fixed by conservation of energy and large gauge transformations. We interpret this result as the explicit realization of the Hawking-Perry-Strominger Ward identity for large gauge transformations in the background of a non-evaporating black hole. Along the way we rederive and extend previous analytic results regarding the absorption rate for the minimal scalar and the photon.

  12. High-accuracy measurements of OH(•) reaction rate constants and IR and UV absorption spectra: ethanol and partially fluorinated ethyl alcohols.

    Science.gov (United States)

    Orkin, Vladimir L; Khamaganov, Victor G; Martynova, Larissa E; Kurylo, Michael J

    2011-08-11

    Rate constants for the gas phase reactions of OH(•) radicals with ethanol and three fluorinated ethyl alcohols, CH(3)CH(2)OH (k(0)), CH(2)FCH(2)OH (k(1)), CHF(2)CH(2)OH (k(2)), and CF(3)CH(2)OH (k(3)) were measured using a flash photolysis resonance-fluorescence technique over the temperature range 220 to 370 K. The Arrhenius plots were found to exhibit noticeable curvature for all four reactions. The temperature dependences of the rate constants can be represented by the following expressions over the indicated temperature intervals: k(0)(220-370 K) = 5.98 × 10(-13)(T/298)(1.99) exp(+515/T) cm(3) molecule(-1) s(-1), k(0)(220-298 K) = (3.35 ± 0.06) × 10(-12) cm(3) molecule(-1) s(-1) [for atmospheric modeling purposes, k(0)(T) is essentially temperature-independent below room temperature, k(0)(220-298 K) = (3.35 ± 0.06) × 10(-12) cm(3) molecule(-1) s(-1)], k(1)(230-370 K) = 3.47 × 10(-14)(T/298)(4.49) exp(+977/T) cm(3) molecule(-1) s(-1), k(2)(220-370 K) = 3.87 × 10(-14)(T/298)(4.25) exp(+578/T) cm(3) molecule(-1) s(-1), and k(3)(220-370 K) = 2.48 × 10(-14)(T/298)(4.03) exp(+418/T) cm(3) molecule(-1) s(-1). The atmospheric lifetimes due to reactions with tropospheric OH(•) were estimated to be 4, 16, 62, and 171 days, respectively, under the assumption of a well-mixed atmosphere. UV absorption cross sections of all four ethanols were measured between 160 and 215 nm. The IR absorption cross sections of the three fluorinated ethanols were measured between 400 and 1900 cm(-1), and their global warming potentials were estimated.

  13. Improved Visible Transparency of SiO2/ZnO:Al/CeO2-TiO2/SiO2 Multilayer Films with High UV Absorption and Infrared Relfection Rate

    Institute of Scientific and Technical Information of China (English)

    NI Jiamiao; ZHAO Xiujian; ZHAO Qingnan; ZHENG Mindong

    2015-01-01

    New visible transparent, UV absorption, and high infrared reflection properties have been realized by depositing multilayer SiO2/ZnO: Al/CeO2-TiO2/SiO2 iflms onto glass substrates at low temperature by radio frequency magnetron sputtering. Optimum thickness of SiO2, ZnO: Al (ZAO) and CeO2-TiO2 (CTO) iflms were designed with the aid of thin iflm design software. The degree of antirelfection can be controlled by adjusting the thickness and refractive index. The outer SiO2 iflm can diminish the interference coloring and increase the transparency; the inner SiO2 iflm improves the adhesion of the coating on the glass substrate and prevents Ca2+, Na+ in the glass substrate from entering the ZAO iflm. The average transmittance in the visible light range increases by nearly 18%-20%, as compared to double layer ZAO/CTO iflms. And the iflms display high infrared relfection rate of above 75% in the wavelength range of 10-25 μm and good UV absorption (>98%) properties. These systems are easy to produce on a large scale at low cost and exhibit high mechanical and chemical durability. The triple functional iflms with high UV absorption, antirelfective and high infrared relfection rate will adapt to application in lfat panel display and architectural coating glass, automotive glass, with diminishing light pollution as well as decreasing eye fatigue and increasing comfort.

  14. High performance heat pump absorption cycles

    Energy Technology Data Exchange (ETDEWEB)

    Lazzarin, R.; Longo, G.; Rossetto, L.

    1988-10-01

    Absorption heat pumps can provide high performances when operating in suitable cycles with multiple effects. This report describes some multistage cycles and evaluates the coefficient of performance realistically obtainable both in winter and summer working conditions.

  15. Experimental Assessment of Specific Absorption Rate Using Room Electromagnetics

    DEFF Research Database (Denmark)

    Bamba, Aliou; Joseph, Wout; Andersen, Jørgen Bach;

    2012-01-01

    to measurement systems, antennas characteristics, diffuse energy properties, and human exposure are investigated. The goal of this paper aims first towards validation of the assessment of the reverberation time in an environment using a virtual MIMO channel system. Secondly, the reverberation time in an adjacent...... room is investigated and hence a measurement based method is readily developed to assess the absorption cross section and the whole-body specific absorption rate of humans at 2.3 GHz in a realistic closed environment....

  16. A simple and fast method for assessment of the nitrogen–phosphorus–potassium rating of fertilizers using high-resolution continuum source atomic and molecular absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Bechlin, Marcos André; Fortunato, Felipe Manfroi; Moutinho da Silva, Ricardo; Ferreira, Edilene Cristina; Gomes Neto, José Anchieta, E-mail: anchieta@iq.unesp.br

    2014-11-01

    The determination of N, P, and K in fertilizers by high-resolution continuum source flame atomic and molecular absorption spectrometry is proposed. Under optimized conditions, measurements of the diatomic molecules NO and PO at 215.360 and 247.620 nm, respectively, and K using the wing of the alternative line at 404.722 nm allowed calibration curves to be constructed in the ranges 500–5000 mg L{sup −1} N (r = 0.9994), 100–2000 mg L{sup −1} P (r = 0.9946), and 100–2500 mg L{sup −1} K (r = 0.9995). Commercial fertilizers were analyzed by the proposed method and the concentrations of N, P, and K were found to be in agreement with those obtained by Kjeldahl, spectrophotometric, and flame atomic emission spectrometry methods, respectively, at a 95% confidence level (paired t-test). A phosphate rock certified reference material (CRM) was analyzed and the results for P and K were in agreement with the reference values. Recoveries from spiked CRM were in the ranges 97–105% (NO{sub 3}{sup −}-N), 95–103% (NH{sub 4}{sup +}-N), 93–103% (urea-N), 99–108% (P), and 99–102% (K). The relative standard deviations (n = 12) for N, P, and K were 6, 4, and 2%, respectively. - Highlights: • A single technique is proposed to analyze NPK fertilizer. • HR-CS FAAS is proposed for the first time for N, P and K determination in fertilizers. • The method employs the same sample preparation and dilution for the three analytes. • Addition of H{sub 2}O{sub 2} allows analysis of fertilizers with different nitrogen species. • Proposal provides advantages over traditional methods in terms of cost and time.

  17. Dynamic mechanical analysis and high strain-rate energy absorption characteristics of vertically aligned carbon nanotube reinforced woven fiber-glass composites

    Science.gov (United States)

    The dynamic mechanical behavior and energy absorption characteristics of nano-enhanced functionally graded composites, consisting of 3 layers of vertically aligned carbon nanotube (VACNT) forests grown on woven fiber-glass (FG) layer and embedded within 10 layers of woven FG, with polyester (PE) and...

  18. High temperature measurement of water vapor absorption

    Science.gov (United States)

    Keefer, Dennis; Lewis, J. W. L.; Eskridge, Richard

    1985-01-01

    An investigation was undertaken to measure the absorption coefficient, at a wavelength of 10.6 microns, for mixtures of water vapor and a diluent gas at high temperature and pressure. The experimental concept was to create the desired conditions of temperature and pressure in a laser absorption wave, similar to that which would be created in a laser propulsion system. A simplified numerical model was developed to predict the characteristics of the absorption wave and to estimate the laser intensity threshold for initiation. A non-intrusive method for temperature measurement utilizing optical laser-beam deflection (OLD) and optical spark breakdown produced by an excimer laser, was thoroughly investigated and found suitable for the non-equilibrium conditions expected in the wave. Experiments were performed to verify the temperature measurement technique, to screen possible materials for surface initiation of the laser absorption wave and to attempt to initiate an absorption wave using the 1.5 kW carbon dioxide laser. The OLD technique was proven for air and for argon, but spark breakdown could not be produced in helium. It was not possible to initiate a laser absorption wave in mixtures of water and helium or water and argon using the 1.5 kW laser, a result which was consistent with the model prediction.

  19. The absorption of carbon monoxide in COSORB solutions : absorption rate and capacity

    NARCIS (Netherlands)

    Hogendoorn, J.A.; Swaaij, W.P.M. van; Versteeg, G.F.

    1995-01-01

    Absorption rate experiments and equilibrium experiments were carried out for the COSORB reaction at 300 K. The equilibrium data at 300 K could reasonably well be described with the following relation: Keq=3.4×10^3=([CuAlCl4.tol.CO][tol])/([CO][CuAlCl4.tol2]) Determination of the kinetics and mechani

  20. Local specific absorption rate in brain tumors at 7 tesla.

    Science.gov (United States)

    Restivo, Matthew C; van den Berg, Cornelis A T; van Lier, Astrid L H M W; Polders, Daniël L; Raaijmakers, Alexander J E; Luijten, Peter R; Hoogduin, Hans

    2016-01-01

    MR safety at 7 Tesla relies on accurate numerical simulations of transmit electromagnetic fields to fully assess local specific absorption rate (SAR) safety. Numerical simulations for SAR safety are currently performed using models of healthy patients. These simulations might not be useful for estimating SAR in patients who have large lesions with potentially abnormal dielectric properties, e.g., brain tumors. In this study, brain tumor patient models are constructed based on scans of four patients with high grade brain tumors. Dielectric properties for the modeled tumors are assigned based on electrical properties tomography data for the same patients. Simulations were performed to determine SAR. Local SAR increases in the tumors by as much as 30%. However, the location of the maximum 10-gram averaged SAR typically occurs outside of the tumor, and thus does not increase. In the worst case, if the tumor model is moved to the location of maximum electric field intensity, then we do observe an increase in the estimated peak 10-gram SAR directly related to the tumor. Peak local SAR estimation made on the results of a healthy patient model simulation may underestimate the true peak local SAR in a brain tumor patient. © 2015 Wiley Periodicals, Inc.

  1. Development of a High Sound Absorption Material CEMCOM

    Institute of Scientific and Technical Information of China (English)

    MA Bao-guo; ZHU Hong-bo; DONG Rong-zhen

    2002-01-01

    Based on sound absorption mechanism of material, the special sound absorption material CEMCOM for road sound insulation is introduced. This high sound absorption material is mainly composed of expanded perlite. Using multiple sound absorption structure can improve sound absorption property of material. According to the preparation principle and durability design of material, a new kind of material with low cost and high durability is developed.

  2. Absorption and loss of iron in toddlers are highly correlated.

    Science.gov (United States)

    Fomon, Samuel J; Nelson, Steven E; Serfass, Robert E; Ziegler, Ekhard E

    2005-04-01

    For estimating the requirements for dietary iron, it is important to know the amount of iron that is lost from the body. Inevitable losses of iron have been determined in adult humans but not in infants or children. We administered (58)Fe, the least abundant stable isotope of iron, to free-living infants at 168 d of age (5.6 mo) and followed them to age 26 mo. There was no dietary restriction after isotope administration. Blood was obtained at regular intervals for determination of isotopic enrichment and indices of iron status. We estimated the quantity of circulating iron, noncirculating active iron, and storage iron at each age. The administered isotope equilibrated with total body iron by 13 mo of age. From 13 to 26 mo of age, we estimated inevitable loss and absorption of iron from the change in tracer abundance in circulating iron. The rate of decrease of tracer abundance was proportional to addition of tracee, i.e., absorption of iron. Conversely, the rate of decrease in quantity of tracer was proportional to removal of tracee, i.e., loss of iron. From 13 to 26 mo of age, iron absorption was (mean +/- SD) 0.49 +/- 0.13 mg/d and inevitable iron loss was 0.25 +/- 0.12 mg/d. Intersubject variability of iron loss and iron absorption was high, and iron loss and absorption were highly correlated (r = 0.789, P absorption from the diet was inadequate to maintain or increase iron nutritional status. The data suggest that, in this cohort, which may be representative, the intake of bioavailable iron from 13 to 26 mo of age was insufficient to maintain iron nutritional status.

  3. 3D finite element simulation of effects of deflection rate on energy absorption for TRIP steel

    Science.gov (United States)

    Hayashi, Asuka; Pham, Hang; Iwamoto, Takeshi

    2015-09-01

    Recently, with the requirement of lighter weight and more safety for a design of automobile, energy absorption capability of structural materials has become important. TRIP (Transformation-induced Plasticity) steel is expected to apply to safety members because of excellent energy absorption capability and ductility. Past studies proved that such excellent characteristics in TRIP steel are dominated by strain-induced martensitic transformation (SIMT) during plastic deformation. Because SIMT strongly depends on deformation rate and temperature, an investigation of the effects of deformation rate and temperature on energy absorption in TRIP is essential. Although energy absorption capability of material can be estimated by J-integral experimentally by using pre-cracked specimen, it is difficult to determine volume fraction of martensite and temperature rise during the crack extension. In addition, their effects on J-integral, especially at high deformation rate in experiment might be quite hard. Thus, a computational prediction needs to be performed. In this study, bending deformation behavior of pre-cracked specimen until the onset point of crack extension are predicted by 3D finite element simulation based on the transformation kinetics model proposed by Iwamoto et al. (1998). It is challenged to take effects of temperature, volume fraction of martensite and deformation rate into account. Then, the mechanism for higher energy absorption characteristic will be discussed.

  4. 3D finite element simulation of effects of deflection rate on energy absorption for TRIP steel

    Directory of Open Access Journals (Sweden)

    Hayashi Asuka

    2015-01-01

    Full Text Available Recently, with the requirement of lighter weight and more safety for a design of automobile, energy absorption capability of structural materials has become important. TRIP (Transformation-induced Plasticity steel is expected to apply to safety members because of excellent energy absorption capability and ductility. Past studies proved that such excellent characteristics in TRIP steel are dominated by strain-induced martensitic transformation (SIMT during plastic deformation. Because SIMT strongly depends on deformation rate and temperature, an investigation of the effects of deformation rate and temperature on energy absorption in TRIP is essential. Although energy absorption capability of material can be estimated by J-integral experimentally by using pre-cracked specimen, it is difficult to determine volume fraction of martensite and temperature rise during the crack extension. In addition, their effects on J-integral, especially at high deformation rate in experiment might be quite hard. Thus, a computational prediction needs to be performed. In this study, bending deformation behavior of pre-cracked specimen until the onset point of crack extension are predicted by 3D finite element simulation based on the transformation kinetics model proposed by Iwamoto et al. (1998. It is challenged to take effects of temperature, volume fraction of martensite and deformation rate into account. Then, the mechanism for higher energy absorption characteristic will be discussed.

  5. Potassium superoxide oxygen generation rate and carbon dioxide absorption rate in coal mine refuge chambers

    Institute of Scientific and Technical Information of China (English)

    Gao Na; Jin Longzhe; Hu Haohao; Huang Xiao; Zhou Li; Fan Linyu

    2015-01-01

    The effects of the molding pressure of a KO2 oxygen plate and the initial concentration of CO2 on the oxygen generation rate, the oxygen generation efficiency, and the carbon dioxide absorption rate were studied using a YES-300 hydraulic press to alter the pressure when forming the oxygen plate used in a coal mine refuge chamber. In addition, changes in the initial concentration of CO2 used in the closed-box model were made by adjusting the CO2 supply system, and a CD-7 multi-function parameter instrument was employed to monitor and record the changes of O2 and CO2 concentration in the closed-box model. Results indicate that the oxygen generation rate of KO2 oxygen plates, the oxygen generation efficiency, and the carbon dioxide absorption rate decrease when there is an increase in the pressure used to mold the oxygen plates, but those values increase when the initial CO2 concentration increases. When the initial concentration of CO2 in the closed-box model is 3.5%and the forming pressure is 10 kN, the average oxygen generation rate of 15 g KO2 oxygen plate is 11.88 ? 10?3 L/min, the oxygen generation efficiency is 80.3%, and the average CO2 absorption rate is 11.0 ? 10?3 L/min. Compared with the condition where the initial CO2 concentration is 1.5%, the results show that average oxygen genera-tion rate of oxygen plates increases by 88.9%, the oxygen generation efficiency increases by 88.9%, and the CO2 absorption rate increases by 100%.

  6. A nomogram for prediction of absorption rate coefficient

    Institute of Scientific and Technical Information of China (English)

    李玉红; 赵欣; 嵇晴; 徐建国; 孙瑞元

    2004-01-01

    Background Previous studies have suggested that nomogram can simplize complicated calculations of several varibles. A simple nomogram was constructed to estimate absorption rate coefficient (ka) by using the peak time (tpeak) and the elimination rate coefficient (ke) of drugs administered orally. Methods The nomogram was based on the plasma concentration-time (C-T) curve equation and the function relation between tpeak, ka and ke. A mathematical analysis was presented for the construction of single chart nomogram. To check the degree of accuracy of the developed nomogram, we used it to analyze retrospective profiles of 46 drugs and compared the ka values obtained graphically and those calculated by numerically solving the descriptive equation. In addition, we measured the carbocisteine concentration of 18 healthy volunteers by HPLC with fluorescence detection. To analyze performance error, the measured carbocisteine concentrations were compared with predicted concentrations by the ka obtained from the nomograms along with the other pharmacokinetic parameters. Results The estimated of ka values from nomograms were in very close proximity with the numerical values. The performance error was as follows: median performance error (MDPE) and median absolute performance error (MDAPE) were 1.32% and 18.15%, respectively. Conclusions The developed nomogram is accurate and reliable. The size of performance error meets the demand of clinical pharmacokinetics. Therefore, the nomograms can offer another convenient and easy method for rational individualized dosage regimens.

  7. Quasi-static magnetic measurements to predict specific absorption rates in magnetic fluid hyperthermia experiments

    OpenAIRE

    Coral, DF; Zelis, PM; de Sousa, ME; Muraca, D.; Lassalle, V.; Nicolas, P.; Ferreira,ML.; van Raap, MBF

    2014-01-01

    In this work, the issue on whether dynamic magnetic properties of polydispersed magnetic colloids modeled using physical magnitudes derived from quasi-static magnetic measurement can be extrapolated to analyze specific absorption rate data acquired at high amplitudes and frequencies of excitation fields is addressed. To this end, we have analyzed two colloids of magnetite nanoparticles coated with oleic acid and chitosan in water displaying, under a radiofrequency field, high and low specific...

  8. Consequences of light absorptance in calculating electron transport rate of desert and succulent plants

    OpenAIRE

    Stemke, JA; Santiago, LS

    2011-01-01

    The proportional light absorptance by photosynthetic tissue (α) is used with chlorophyll (Chl) fluorescence methods to calculate electron transport rate (ETR). Although a value of α of 0.84 is often used as a standard for calculating ETR, many succulent plant species and species with crassulacean acid metabolism (CAM) have photosynthetic tissues that vary greatly in color or are highly reflective, and could have values of α that differ from 0.84, thus affecting the calculation of ETR. We meas...

  9. High rate drift chambers

    Energy Technology Data Exchange (ETDEWEB)

    Christian, D.C. (Fermilab, Batavia, IL 60510 (United States)); Berisso, M.C. (Fermilab, Batavia, IL 60510 (United States)); Gutierrez, G. (Fermilab, Batavia, IL 60510 (United States)); Holmes, S.D. (Fermilab, Batavia, IL 60510 (United States)); Wehmann, A. (Fermilab, Batavia, IL 60510 (United States)); Avilez, C. (Instituto de Fisica, Universidad de Guanajuato, Leon, Guanajuato (Mexico)); Felix, J. (Instituto de Fisica, Universidad de Guanajuato, Leon, Guanajuato (Mexico)); Moreno, G. (Instituto de Fisica, Universidad de Guanajuato, Leon, Guanajuato (Mexico)); Romero, M. (Instituto de Fisica, Universidad de Guanajuato, Leon, Guanajuato (Mexico)); Sosa, M. (Instituto de Fisica, Universidad de Guanajuato, Leon, Guanajuato (Mexico)); Forbush, M. (Department of Physics, Texas A and M University, College Station, TX 77843 (United States)); Huson, F.R. (Department of Physics, Texas A and M University, College Station, TX 77843 (United States)); Wightman, J.A. (Department of Physi

    1994-06-01

    Fermilab experiment 690, a study of target dissociation reactions pp[yields]pX using an 800 GeV/c proton beam and a liquid hydrogen target, collected data in late 1991. The incident beam and 600-800 GeV/c scattered protons were measured using a system of six 6 in.x4 in. and two 15 in.x8 in. pressurized drift chambers spaced over 260 m. These chambers provided precise measurements at rates above 10 MHz (2 MHz per cm of sense wire). The measurement resolution of the smaller chambers was 90 [mu]m, and the resolution of the larger chambers was 125 [mu]m. Construction details and performance results, including radiation damage, are presented. ((orig.))

  10. Examination of the Measurement of Absorption Using the Reverberant Room Method for Highly Absorptive Acoustic Foam

    Science.gov (United States)

    Hughes, William O.; McNelis, Anne M.; Chris Nottoli; Eric Wolfram

    2015-01-01

    The absorption coefficient for material specimens are needed to quantify the expected acoustic performance of that material in its actual usage and environment. The ASTM C423-09a standard, "Standard Test Method for Sound Absorption and Sound Absorption Coefficients by the Reverberant Room Method" is often used to measure the absorption coefficient of material test specimens. This method has its basics in the Sabine formula. Although widely used, the interpretation of these measurements are a topic of interest. For example, in certain cases the measured Sabine absorption coefficients are greater than 1.0 for highly absorptive materials. This is often attributed to the diffraction edge effect phenomenon. An investigative test program to measure the absorption properties of highly absorbent melamine foam has been performed at the Riverbank Acoustical Laboratories. This paper will present and discuss the test results relating to the effect of the test materials' surface area, thickness and edge sealing conditions. A follow-on paper is envisioned that will present and discuss the results relating to the spacing between multiple piece specimens, and the mounting condition of the test specimen.

  11. Effects of Photon Absorption in High Energy Heavy Ion Collisions

    Science.gov (United States)

    Winchell, Joshua; Somanathan, Sidharth; Fries, Ranier

    2014-09-01

    Photons are an important probe of the hot and dense nuclear matter created in high-energy collisions of nuclei at the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC). Since the mean free path of photons is larger than the size of the fireball of nuclear matter, final state interactions of photons are usually neglected. In light of recent tension between theoretical calculations and data from RHIC and LHC, we study the effect of reabsorption of photons on elliptic flow v2 and on the nuclear modification factor RAA. We consider photons emitted in primary hard collisions and thermal photons from quark-gluon plasma and hot hadron gas. We use the jet-quenching code PPM to simulate the propagation of those photons in a fireball of quark-gluon plasma and hot hadron gas created by collisions of heavy nuclei. For the absorption cross-sections we consider three different approaches: (a) Compton and pair production processes calculated by us in a static approximation, (b) the photon damping rates calculated by Thoma (1995), and (c) absorption rates derived from a recent photon calculation by van Hees et al.

  12. Prostaglandin E2 regulation of amnion cell vascular endothelial growth factor expression: relationship with intramembranous absorption rate in fetal sheep.

    Science.gov (United States)

    Cheung, Cecilia Y; Beardall, Michael K; Anderson, Debra F; Brace, Robert A

    2014-08-01

    We hypothesized that prostaglandin E2 (PGE2) stimulates amniotic fluid transport across the amnion by upregulating vascular endothelial growth factor (VEGF) expression in amnion cells and that amniotic PGE2 concentration correlates positively with intramembranous (IM) absorption rate in fetal sheep. The effects of PGE2 at a range of concentrations on VEGF 164 and caveolin-1 gene expressions were analyzed in cultured ovine amnion cells. IM absorption rate, amniotic fluid (AF) volume, and PGE2 concentration in AF were determined in late-gestation fetal sheep during control conditions, isovolumic fetal urine replacement (low IM absorption rate), or intra-amniotic fluid infusion (high IM absorption rate). In ovine amnion cells, PGE2 induced dose- and time-dependent increases in VEGF 164 mRNA levels and reduced caveolin-1 mRNA and protein levels. VEGF receptor blockade abolished the caveolin-1 response, while minimally affecting the VEGF response to PGE2. In sheep fetuses, urine replacement reduced amniotic PGE2 concentration by 58%, decreased IM absorption rate by half, and doubled AF volume (P amniotic fluid infusion increased IM absorption rate and AF volume (P amniotic PGE2 concentration was unchanged. Neither IM absorption rate nor AF volume correlated with amniotic PGE2 concentration under each experimental condition. Although PGE2 at micromolar concentrations induced dose-dependent responses in VEGF and caveolin-1 gene expression in cultured amnion cells consistent with a role of PGE2 in activating VEGF to mediate AF transport across the amnion, amniotic PGE2 at physiological nanomolar concentrations does not appear to regulate IM absorption rate or AF volume.

  13. Exploring the origin of high optical absorption in conjugated polymers

    KAUST Repository

    Vezie, Michelle S.

    2016-05-16

    The specific optical absorption of an organic semiconductor is critical to the performance of organic optoelectronic devices. For example, higher light-harvesting efficiency can lead to higher photocurrent in solar cells that are limited by sub-optimal electrical transport. Here, we compare over 40 conjugated polymers, and find that many different chemical structures share an apparent maximum in their extinction coefficients. However, a diketopyrrolopyrrole-thienothiophene copolymer shows remarkably high optical absorption at relatively low photon energies. By investigating its backbone structure and conformation with measurements and quantum chemical calculations, we find that the high optical absorption can be explained by the high persistence length of the polymer. Accordingly, we demonstrate high absorption in other polymers with high theoretical persistence length. Visible light harvesting may be enhanced in other conjugated polymers through judicious design of the structure.

  14. Absolute absorption cross-section and photolysis rate of I2

    Directory of Open Access Journals (Sweden)

    J. M. C. Plane

    2004-05-01

    Full Text Available Following recent observations of molecular iodine (I2 in the coastal marine boundary layer (MBL (Saiz-Lopez and Plane, 2004, it has become important to determine the absolute absorption cross-section of I2 at reasonably high resolution, and also to evaluate the rate of photolysis of the molecule in the lower atmosphere. The absolute absorption cross-section (σ of gaseous I2 at room temperature and pressure (295 K, 760 Torr was therefore measured between 182 and 750 nm using a Fourier Transform spectrometer at a resolution of 4 cm−1 (0.1 nm at λ=500 nm. The maximum absorption cross-section in the visible region was observed at λ=533.0 nm to be σ=(4.84±0.60×10−18cm2 molecule−1. The spectrum is available as supplementary material accompanying this paper. The photo-dissociation rate constant (J of gaseous I2 was also measured directly in a solar simulator, yielding J(I2=0.12±0.03 s−1 for the lower troposphere. This agrees well with the value of 0.15±0.03 s−1 calculated using the measured absorption cross-section, terrestrial solar flux for clear sky conditions and assuming a photo-dissociation yield of unity. A two-stream radiation transfer model was then used to determine the variation in photolysis rate with solar zenith angle (SZA, from which an analytic expression is derived for use in atmospheric models. Photolysis appears to be the dominant loss process for I2 during daytime, and hence an important source of iodine atoms in the lower atmosphere.

  15. Very High Temperature Sound Absorption Coating Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Phase I demonstrated experimentally a very high temperature acoustically absorbing coating for ducted acoustics applications. High temperature survivability at 3500...

  16. Tunable absorption in heterostructures composed of a highly absorptive metallic film and Fibonacci fractal photonic crystals

    Science.gov (United States)

    Qiao, Wei; Sun, Jie; Du, Gui-Qiang

    2016-03-01

    We have theoretically investigated the anomalous optical properties of heterostructures composed of a highly absorptive metal film and a truncated Fibonacci fractal photonic crystal. It is found that one or multiple highly reflected peaks, even enhanced transmission narrowband, can be realized in the near-complete absorption broadband, where the photonic crystals are selected with various Fibonacci sequences or a given sequence as the basic unit. These properties are significant to design important reflection or transmission optical devices in the visible and near-infrared ranges.

  17. Determination of sedimentation rates and absorption coefficient of ...

    African Journals Online (AJOL)

    DR. MIKE HORSFALL

    showed a decrease in the density of the carbonates and also correlated with the decrease in the mass (and ... Many chemical reactions form separable solid phase ... The precipitates were ... Zn2+ had the highest sedimentation rate constants,.

  18. Cosmic absorption of ultra high energy particles

    Science.gov (United States)

    Ruffini, R.; Vereshchagin, G. V.; Xue, S.-S.

    2016-02-01

    This paper summarizes the limits on propagation of ultra high energy particles in the Universe, set up by their interactions with cosmic background of photons and neutrinos. By taking into account cosmic evolution of these backgrounds and considering appropriate interactions we derive the mean free path for ultra high energy photons, protons and neutrinos. For photons the relevant processes are the Breit-Wheeler process as well as the double pair production process. For protons the relevant reactions are the photopion production and the Bethe-Heitler process. We discuss the interplay between the energy loss length and mean free path for the Bethe-Heitler process. Neutrino opacity is determined by its scattering off the cosmic background neutrino. We compute for the first time the high energy neutrino horizon as a function of its energy.

  19. Lipid nanoparticles with no surfactant improve oral absorption rate of poorly water-soluble drug.

    Science.gov (United States)

    Funakoshi, Yuka; Iwao, Yasunori; Noguchi, Shuji; Itai, Shigeru

    2013-07-15

    A pharmacokinetic study was performed in rats to evaluate the oral absorption ratios of nanoparticle suspensions containing the poorly water-soluble compound nifedipine (NI) and two different types of lipids, including hydrogenated soybean phosphatidylcholine and dipalmitoylphosphatidylglycerol. NI-lipid nanoparticle (LN) suspensions with a mean particle size of 48.0 nm and a zeta potential of -57.2 mV were prepared by co-grinding combined with a high-pressure homogenization process. The oral administration of NI-LN suspensions to rats led to a significant increase in the NI plasma concentration, and the area under the curve (AUC) value was found to be 108 min μg mL⁻¹, indicating a 4-fold increase relative to the NI suspensions. A comparison of the pharmacokinetic parameters of the NI-LN suspensions with those of the NI solution prepared using only the surfactant polysorbate 80 revealed that although the AUC and bioavailability (59%) values were almost identical, a rapid absorption rate was still observed in the NI-LN suspensions. These results therefore indicated that lipid nanoparticles prepared using only two types of phospholipid with a mean particle size of less than 50 nm could improve the absorption of the poorly water-soluble drug. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Rate of absorption and interfacial area of chlorine into aqueous ...

    African Journals Online (AJOL)

    aghomotsegin

    solutions of sodium hydroxide is industrially important in several chemical processes particularly in pollution ... The values of rate constant for Cl2 - NaOH reaction system. Author ..... reactor/ejector (Figure 1) (m3); wi, concentration of species i ...

  1. Experimental measurement and modeling of the rate of absorption of carbon dioxide by aqueous ammonia

    DEFF Research Database (Denmark)

    Darde, Victor Camille Alfred; van Well, Willy J.M.; Fosbøl, Philip Loldrup

    2011-01-01

    In this work, the rate of absorption of carbon dioxide by aqueous ammonia solvent has been studied by applying a newly built wetted wall column. The absorption rate in aqueous ammonia was measured at temperatures from 279 to 304K for 1 to 10wt% aqueous ammonia with loadings varying from 0 to 0.8mol......CO2/molNH3. The absorption rate in 30wt% aqueous mono-ethanolamine (MEA) was measured at 294 and 314K with loadings varying from 0 to 0.4 as comparison.It was found that at 304K, the rate of absorption of carbon dioxide by 10wt% NH3 solvent was comparable to the rates for 30wt% MEA at 294 and 314K (a.......The rate of absorption decreases strongly with decreasing ammonia concentrations and increasing CO2 loadings.The rate of absorption of carbon dioxide by aqueous ammonia solvent was modeled using the measurements of the unloaded solutions and the zwitter-ion mechanism. The model could successfully predict...

  2. Highly efficient plasmonic enhancement of graphene absorption at telecommunication wavelengths.

    Science.gov (United States)

    Lu, Hua; Cumming, Benjamin P; Gu, Min

    2015-08-01

    A hybrid graphene system consisting of graphene and silica layers coated on a metal film with groove rings is proposed to strongly enhance light absorption in the graphene layer. Our results indicate that the excited localized plasmon resonance in groove rings can effectively improve the graphene absorption from 2.3% to 43.1%, even to a maximum value of 87.0% in five-layer graphene at telecommunication wavelengths. In addition, the absorption peak is strongly dependent on the groove depth and ring radius as well as the number of graphene layers, enabling the flexible selectivity of both the operating spectral position and bandwidth. This favorable enhancement and tunability of graphene absorption could provide a path toward high-performance graphene opto-electronic components, such as photodetectors.

  3. Determining neutrino absorption spectra at Ultra-High Energies

    CERN Document Server

    Scholten, Olaf

    2008-01-01

    The Low-Frequency Array (LOFAR), which will be available in the near future, will have an un-precedented sensitivity to measure the flux of Ultra-high energy (UHE) neutrinos. As such it promises to be ultimately suited for determining absorption lines in the neutrino spectrum as predicted by the absorption on the low-energy relic anti-neutrino background through the Z-boson resonance. The position of this absorption peak is sensitive to the neutrino mass and the redshift of the source. The most sensitive way to measure UHE neutrinos is via emitted radio waves when they impact on the moon. In this work we investigate the sensitivity of this detection method to the predicted absorption structures in the neutrino spectrum. A new generation of low-frequency digital radio telescopes will provide excellent detection capabilities for measuring these radio pulses, thus making our consideration here very timely.

  4. Effect of fine solid particles on absorption rate of gaseous CO2

    Institute of Scientific and Technical Information of China (English)

    Sumin LU; Youguang MA; Shuhua SHEN; Chunying ZHU

    2008-01-01

    The influence of the properties of solid particles in slurry on the absorption of CO2 in the slurry was inves-tigated in a stirred thermostatic reactor. The absorption experiments were carried out in three different slurries con-sisting of water, cyclohexane and soybean oil, respectively, and three kinds of solid particles (active carbon, active alu-mina and silica gel) were incorporated into each of the above mentioned slurries separately. The experimental results show that the active carbon particles could enhance the absorption rate of gaseous CO2 in the aqueous slurry, while in the cyclohexane slurry, active carbon particles indi-cated no the absorption enhancement effect. However, it was observed that the active alumina and silica gel particles could enhance the absorption rate of CO2 in the cyclohex-ane slurry. These phenomena indicate that the solid part-icles, which could enhance the gaseous CO2 absorption rate, should possess two properties simultaneously, i.e. they rejected the solvent and had higher adsorption capacity for the solute. The experimental results also show that, as for those solid particles which could enhance the gas absorption rate, the enhancement increased quickly with the increase of solid concentration in slurry at first, and then reached a constant value gradually. It was also found that the enhancement factor was related to the coverage fraction of solid particles on the gas-liquid interface, and due to the reduction of surface fraction with increasing stirred speed, the enhancement factor decreased.

  5. Absorption and desorption mass transfer rates in chemically enhanced reactive systems. Part II : Reverse kinetic rate parameters

    NARCIS (Netherlands)

    Hamborg, Espen S.; Versteeg, Geert F.

    2012-01-01

    The forward and reverse kinetic rate parameters have been determined for CO2 absorption and desorption mass transfer processes in aqueous 2.0 M MDEA solutions at temperatures of 298.15, 313.15, and 333.15 K and the loading of CO2 ranging from 0 to 0.8. The derived kinetic rate parameters have been b

  6. Photoacoustic absorption spectrometer for highly transparent dielectrics with parts-per-million sensitivity

    Science.gov (United States)

    Waasem, Niklas; Fieberg, Stephan; Hauser, Janosch; Gomes, Gregory; Haertle, Daniel; Kühnemann, Frank; Buse, Karsten

    2013-02-01

    A sensitive photoacoustic absorption spectrometer for highly transparent solids has been built and tested. As the light source an optical parametrical oscillator pumped by a nanosecond pulse laser with 10 Hz repetition rate is employed, covering the complete wavelength range from 407 to 2600 nm. A second-harmonic-generation unit extends the range of accessible wavelengths down to 212 nm. A lead-zirconate-titanate piezo transducer, directly coupled to the sample, detects the photoacoustically generated sound waves. Absorption spectra of lithium triborate, lithium niobate, and alpha barium borate crystals with absorption coefficients down to 10-5 cm-1 are presented.

  7. Activable enriched stable isotope iron-58 for monitoring absorption rate of juvenile athletes for iron: a case study.

    Science.gov (United States)

    Qian, Qinfang; Chai, Zhifang; Feng, Weiyu; Chen, Jidi; Zhang, Peiqun; Pan, Jianxiang

    2002-09-01

    Activable enriched stable isotopes can play a unique role in studies of nutritional status, metabolism, absorption rates, and bioavailability of minerals. As a practical example, eight juvenile athletes were selected to test the absorption rates of iron during training and non-training periods by enriched stable isotope of Fe-58 (enriched degree: 51.1%) via activation analysis Fe-58 (n, gamma) Fe-59 of the collected feces samples. The results indicated that the average iron absorption rates of the juvenile athletes with and without training are 9.1 +/- 2.8 and 11.9 +/- 4.7%, respectively, which implies that the long-term endurance training with high intensity makes the iron absorption rate of athletes lower. In the meantime, the comparison of the activable enriched isotope technique with atomic absorption spectrometry was performed, which showed that the former was better than the latter in reliability and sensitivity. It is because this nuclear method can distinguish the exogenous and endogenous iron in the samples, but not for non-nuclear methods.

  8. Intelligent predicting approach of peritoneal fluid absorption rate based-on neural network

    Institute of Scientific and Technical Information of China (English)

    Mei ZHANG; Yueming HU; Tao WANG

    2003-01-01

    This paper addresses the important intelligent predicting problem of peritoneal absorption rate in the peritoneal dialysis treament process of renal failure. As the index of dialysis adequacy, KT/V and Ccr are widely used and accepted. However,growing evidence suggests that the fluid balance may play a critical role in dialysis adequacy and patient outcome. Peritoneal fluid absorption decreases the peritoneal fluid removal. Understanding the peritoneal fluid absorption rate will help clinicians to opthnize the dialysis dwell time. The neural network approach is applied to the prediction of peritoneal absorption rate. Compared with multivariable regression method, the experimental results showed that neural network method has an advantage over multivariable regression. The application of this predicting method based-on neural network in clinic is instructive.

  9. Carbonic anhydrase promotes the absorption rate of CO2 in post-combustion processes.

    Science.gov (United States)

    Vinoba, Mari; Bhagiyalakshmi, Margandan; Grace, Andrews Nirmala; Kim, Dae Hoon; Yoon, Yeoil; Nam, Sung Chan; Baek, Il Hyun; Jeong, Soon Kwan

    2013-05-09

    The rate of carbon dioxide (CO2) absorption by monoethanol amine (MEA), diethanol amine (DEA), N-methyl-2,2'-iminodiethanol (MDEA), and 2-amino-2-methyl 1-propanol (AMP) solutions was found to be enhanced by the addition of bovine carbonic anhydrase (CA), has been investigated using a vapor-liquid equilibrium (VLE) device. The enthalpy (-ΔHabs) of CO2 absorption and the absorption capacities of aqueous amines were measured in the presence and/or absence of CA enzyme via differential reaction calorimeter (DRC). The reaction temperature (ΔT) under adiabatic conditions was determined based on the DRC analysis. Bicarbonate and carbamate species formation mechanisms were elucidated by (1)H and (13)C NMR spectral analysis. The overall CO2 absorption rate (flux) and rate constant (kapp) followed the order MEA > DEA > AMP > MDEA in the absence or presence of CA. Hydration of CO2 by MDEA in the presence of CA directly produced bicarbonate, whereas AMP produced unstable carbamate intermediate, then underwent hydrolytic reaction and converted to bicarbonate. The MDEA > AMP > DEA > MEA reverse ordering of the enhanced CO2 flux and kapp in the presence of CA was due to bicarbonate formation by the tertiary and sterically hindered amines. Thus, CA increased the rate of CO2 absorption by MDEA by a factor of 3 relative to the rate of absorption by MDEA alone. The thermal effects suggested that CA yielded a higher activity at 40 °C.

  10. Extragalactic Absorption of High Energy $\\gamma$-Rays

    CERN Document Server

    Stecker, F W

    1999-01-01

    The pair-production absorption of high-energy gamma-rays by intergalactic low-energy photons is expected to produce a high-energy cutoff in the spectra of extragalactic sources which is a sensitive function of redshift. We first discuss the expected absorption coefficient as a function of energy and redshift derived by Stecker and De Jager by making use of a new empirically based calculation of the spectral energy distribution of the intergalactic infrared radiation field as given by Malkan and Stecker. We then discuss the fact that new data on the high energy gamma-ray source Mrk 501 appear to show the amount of intergalactic absorption predicted. The implications of this new HEGRA data, should they be confirmed, are significant for the astrophysics of this source, implying that (1) there is no significant intrinsic absorption inside the source, and (2) the physics of the emission produces a power-law spectrum to energies above 20 TeV. As a further test for intergalactic absorption, we give a predicted spect...

  11. EVALUATION OF THE STRUCTURAL FUNDS ABSORPTION RATE BY MEANS OF THE HERMIN MODEL

    Directory of Open Access Journals (Sweden)

    Opritescu Elena Madalina

    2012-07-01

    Full Text Available The main objective of this article is to highlight the main method that could quantify the impact of the structural funds on the Gross Domestic Product. I also presented the regional disparities situation and the European funds absorption rate. The HERMIN model has been designed considering the evolution of macro-variables throughout transition and pre-accession process, as well as out of the need to analyze the gradual alignment of Romania’s economic policies to those of EU. The fact that, initially, the HERMIN model was designed for the European Union’s less developed economies represented the cornerstone in choosing it, as it was the case for Romania, too. However, the quantitative evaluation must always be accompanied by a qualitative evaluation, in order to comprise factors which cannot be measured by the econometrical modeling. For this purpose, when the results of econometrical model based evaluation are used, it is important to be aware of the fact that models simplify reality, no matter the impressive mathematical calculations they employ. Also, we must not omit the fact that Romania’s major development needs and the current economic context imperatively demand a high as possible level of structural funds absorption, as well as their efficient use, meant to generate a significant impact at a national, regional and local level. One of the main instruments employed to sustain economic growth, while also reducing disparities between regions is represented by the structural funds. These funds, consisting in financial contributions of the member states, according to their level of development, are redistributed in compliance with an extremely complex regulating and procedural frame, to those EU states of regions which are fallen behind from a social and economical development perspective Nevertheless, when absorption capacity of a member state is evaluated, the used percentage from the allocated funds is not the only

  12. Dual absorptive model and np elastic scattering at high energies

    Energy Technology Data Exchange (ETDEWEB)

    Saleem, M.; Fazal-e-Aleem

    1980-06-01

    The most recent measurements of the angular distribution and total cross-sections in np elastic scattering at high energies from 70 to 400 GeV/c have been fitted by using the dual absorptive model. Comparison has also been made with the Kane-Siedl model and the simple Regge pole model.

  13. [Burner head with high sensitivity in atomic absorption spectroscopy].

    Science.gov (United States)

    Feng, X; Yang, Y

    1998-12-01

    This paper presents a burner head with gas-sample separate entrance and double access, which is used for atomic absorption spectroscopy. According to comparison and detection, the device can improve sensitivity by a factor of 1 to 5. In the meantime it has properties of high stability and resistance to interference.

  14. High Data Rate Quantum Cryptography

    Science.gov (United States)

    Kwiat, Paul; Christensen, Bradley; McCusker, Kevin; Kumor, Daniel; Gauthier, Daniel

    2015-05-01

    While quantum key distribution (QKD) systems are now commercially available, the data rate is a limiting factor for some desired applications (e.g., secure video transmission). Most QKD systems receive at most a single random bit per detection event, causing the data rate to be limited by the saturation of the single-photon detectors. Recent experiments have begun to explore using larger degree of freedoms, i.e., temporal or spatial qubits, to optimize the data rate. Here, we continue this exploration using entanglement in multiple degrees of freedom. That is, we use simultaneous temporal and polarization entanglement to reach up to 8.3 bits of randomness per coincident detection. Due to current technology, we are unable to fully secure the temporal degree of freedom against all possible future attacks; however, by assuming a technologically-limited eavesdropper, we are able to obtain 23.4 MB/s secure key rate across an optical table, after error reconciliation and privacy amplification. In this talk, we will describe our high-rate QKD experiment, with a short discussion on our work towards extending this system to ship-to-ship and ship-to-shore communication, aiming to secure the temporal degree of freedom and to implement a 30-km free-space link over a marine environment.

  15. The rate and extent of oral bioavailability versus the rate and extent of oral absorption: clarification and recommendation of terminology.

    Science.gov (United States)

    Chiou, W L

    2001-02-01

    In the literature, the meanings of the terms oral absorption and oral bioavailability of drugs vary greatly. Absorption has been considered to take place at the mucosal membrane of the gastrointestinal (GI) tract. It has also been defined as the process from the site of drug administration to the site of measurement. In the latter definition, the extent of oral absorption depends on the extent of first-pass elimination in the gut wall and liver even though a drug may be completely absorbed from the GI tract. Moreover, these two terms have also been used interchangeably. Inconsistency in the definition of these two terms has led to varying interpretations of these terms among students, researchers and laymen, and such an inconsistency seems undesirable. Apparently because of these inconsistencies, improper correlations between the Caco-2 permeability or intestinal permeability and the oral bioavailability of drugs subject to extensive first-pass effect may have occurred. It is suggested that absorption be defined as movement of drug across the outer mucosal membranes of the GI tract, while bioavailability be defined as availability of drug to the general circulation or site of pharmacological actions. Since transit times (this may range from about 1 min to several hours) across enterocytes, liver, lungs, and the peripheral venous sampling tissue are virtually unknown for all drugs, this factor alone would favor the use of "oral bioavailability rate" rather than "oral absorption rate" in all routine studies.

  16. Terahertz ammonia absorption as a probe of infall in high-mass star forming clumps

    CERN Document Server

    Wyrowski, F; Menten, K M; Wiesemeyer, H; Klein, B

    2012-01-01

    Cloud contraction and infall are the fundamental processes of star formation. While "blue-skewed" line profiles observed in high- mass star forming regions are commonly taken as evidence of infall by an ever increasing number of studies, their interpretation offers many pitfalls. Detecting infall via redshifted absorption in front of continuum sources is a much more direct and reliable method but so far mostly restricted toward absorption in the centimeter toward strong HII regions. Here we present a novel approach by probing absorption of rotational ammonia transitions in front of the strong dust emission of massive star-forming regions. A carefully selected sample of three regions with different stages of evolution is selected to study infall through the evolution of massive star-forming clumps. Redshifted absorption is detected toward all three sources and infall rates between 3-10x10-3 Msol yr-1 are derived.

  17. Approach for an improved experimental evaluation of the specific absorption rate in magnetic fluid hyperthermia

    Energy Technology Data Exchange (ETDEWEB)

    Iacob, N. [National Institute for Lasers, Plasma and Radiation Physics (Romania); Schinteie, G.; Palade, P.; Kuncser, V., E-mail: kuncser@infim.ro [National Institute of Materials Physics (Romania)

    2015-04-15

    A new methodology for the accurate determination of the specific absorption rate of ferrofluids with magnetite nanoparticles of average size of about 10 nm subjected to alternative current magnetic fields is proposed. A simple numerical compensation of the heating rates by the cooling rates obtained at similar temperatures is employed. Comparisons of the as-obtained adiabatic heating curves with theoretical evaluations are discussed.

  18. Temperature-dependent high resolution absorption cross sections of propane

    Science.gov (United States)

    Beale, Christopher A.; Hargreaves, Robert J.; Bernath, Peter F.

    2016-10-01

    High resolution (0.005 cm-1) absorption cross sections have been measured for pure propane (C3H8). These cross sections cover the 2550-3500 cm-1 region at five temperatures (from 296 to 700 K) and were measured using a Fourier transform spectrometer and a quartz cell heated by a tube furnace. Calibrations were made by comparison to the integrated cross sections of propane from the Pacific Northwest National Laboratory. These are the first high resolution absorption cross sections of propane for the 3 μm region at elevated temperatures. The cross sections provided may be used to monitor propane in combustion environments and in astronomical sources such as the auroral regions of Jupiter, brown dwarfs and exoplanets.

  19. High-Resolution Structural Monitoring of Ionospheric Absorption Events

    Science.gov (United States)

    2013-07-01

    figure 1, taken from observations by the 30 MHz riometer operating at the High Frequency Active Auroral Research Program ( HAARP ) facility in Alaska...1200 UTC and persisting for the next two days. Figure 3 shows two records from the HAARP 30 MHz riometer, pasted together to cover 20 November 2003...absorption event seen by HAARP 30 MHz riometer. Figure 2: Electron depletion event 8 observed by HEO-3 satellite on 20 November 2003. Figure 3

  20. High doses of vitamin A impair iron absorption

    Directory of Open Access Journals (Sweden)

    Gabriel FR

    2012-10-01

    Full Text Available Fabíola Rainato Gabriel, Vivian MM Suen, Julio Sergio Marchini, José Eduardo Dutra de OliveiraDivision of Clinical Nutrition, Department of Internal Medicine, Ribeirão Preto School of Medicine, São Paulo University, São Paulo, BrazilObjective: The present study aimed to determine the influence of vitamin A on iron absorption when vitamin A and iron are administered together orally compared with the administration of iron alone.Methods: This was a randomized double-blind clinical trial conducted on healthy men with normal red blood cell indices. Five experiments were performed, with iron (10 mg; iron (10 mg plus vitamin A (450, 900 and 1800 µg, and placebo. After an 8-hour fast, basal (T0 blood samples were collected: basal (T0, 2 hours (T1, and 4 hours (T2 after the ingestion of the compounds to be studied. Iron was determined by inductively coupled plasma mass spectrometry. Serum ferritin was determined by an immunometric method, ie, by chemoluminescent enzyme immunoassay. Plasma retinol was measured by high-pressure liquid chromatography. Serum curves and the sum of the area under the curve adjusted to the mixed effects linear model were determined (P < 0.05.Results: Vitamin A at the doses of 450 and 900 µg had a stimulating effect, which, however, did not differ significantly from that of experiment 1 in which iron was used alone. At the dose of 1800 µg, vitamin A had a negative effect on iron absorption.Conclusion: High doses of vitamin A may cause lower serum iron levels, whereas a low dose favors iron absorption.Keywords: iron absorption, serum iron, vitamin A, oral iron, oral supplement

  1. Inverse bremsstrahlung absorption with nonlinear effects of high laser intensity and non-Maxwellian distribution.

    Science.gov (United States)

    Weng, Su-Ming; Sheng, Zheng-Ming; Zhang, Jie

    2009-11-01

    Inverse bremsstrahlung (IB) absorption and evolution of the electron distribution function (EDF) in a wide laser intensity range (10;{12}-10;{17} W/cm;{2}) have been studied systematically by a two velocity-dimension Fokker-Planck code. It is found that Langdon's IB operator overestimates the absorption rate at high laser intensity, consequently with an overdistorted non-Maxwellian EDF. According to the small anisotropy of EDF in the oscillation frame, we introduce an IB operator which is similar to Langdon's but without the low laser intensity limit. This operator is appropriate for self-consistently tackling the nonlinear effects of high laser intensity as well as non-Maxwellian EDF. Particularly, our operator is capable of treating IB absorption properly in the indirect and direct-drive inertial confinement fusion schemes with the National Ignition Facility and Laser MegaJoule laser parameters at focused laser intensity beyond 10;{15} W/cm;{2} .

  2. NaFeEDTA Fortified Soy Sauce Showed Higher Iron Absorption Rate in Chinese Females

    Institute of Scientific and Technical Information of China (English)

    JUN-SHENG HUO; XIAO-GUANG YANG; JIAN-HUA PIAO; JUN-QUAN GAO; HONG MIAO; Bo YU; CHENG-QIAN LU; JUN-SHI CHEN

    2007-01-01

    Objective NaFeEDTA was considered as a promising iron fortificant for controlling iron deficiency anemia. Soy sauce is a suitable food carrier for iron fortification and is a popular condiment in China. Iron absorption rates of NaFeEDTA and FeSO4were observed and compared in adult female subjects. Methods The stable isotope tracer method was used in Chinese females consuming a typical Chinese diet. Ten healthy young Chinese women were selected as subjects in the 15-day study. A plant-based diet was used based on the dietary pattern of adult women in the 1992 National Nutrition Survey. Six milligram of54Fe in 54FeSO4 soy sauce and 3 mg 58Fe in Na58FeEDTA soy sauce were given to the same subjects in two days. Food samples and fecal samples were collected and analyzed. Results Iron absorption rates of NaFeEDTA and FeSO4 were 10.51%±2.83and 4.73%±2.15 respectively. The 58Fe (NaFeEDTA) absorption was significantly higher than that of 54Fe (FeSO4) (P<0.01).The iron absorption rate from NaFeEDTA was 1.2 times higher than that from FeSO4 in Chinese adult women consuming a typical Chinese diet. Conclusion The higher absorption rate of NaFeEDTA suggested that NaFeEDTA would be a better iron fortificant used in soy sauce for the controlling of iron deficiency anemia in China.

  3. Shock tube/laser absorption measurements of the reaction rates of OH with ethylene and propene.

    Science.gov (United States)

    Vasu, Subith S; Hong, Zekai; Davidson, David F; Hanson, Ronald K; Golden, David M

    2010-11-04

    Reaction rates of hydroxyl (OH) radicals with ethylene (C₂H₄) and propene (C₃H₆) were studied behind reflected shock waves. OH + ethylene → products (rxn 1) rate measurements were conducted in the temperature range 973-1438 K, for pressures from 2 to 10 atm, and for initial concentrations of ethylene of 500, 751, and 1000 ppm. OH + propene → products (rxn 2) rate measurements spanned temperatures of 890-1366 K, pressures near 2.3 atm, and initial propene concentrations near 300 ppm. OH radicals were produced by shock-heating tert-butyl hydroperoxide, (CH₃)₃-CO-OH, and monitored by laser absorption near 306.7 nm. Rate constants for the reactions of OH with ethylene and propene were extracted by matching modeled and measured OH concentration time-histories in the reflected shock region. Current data are in excellent agreement with previous studies and extend the temperature range of OH + propene data. Transition state theory calculations using recent ab initio results give excellent agreement with our measurements and other data outside our temperature range. Fits (in units of cm³/mol/s) to the abstraction channels of OH + ethylene and OH + propene are k₁ = 2.23 × 10⁴ (T)(2.745) exp(-1115 K/T) for 600-2000 K and k₂ = 1.94 × 10⁶ (T)(2.229) exp(-540 K/T) for 700-1500 K, respectively. A rate constant determination for the reaction TBHP → products (rxn 3) was also obtained in the range 745-1014 K using OH data from behind both incident and reflected shock waves. These high-temperature measurements were fit with previous low-temperature data, and the following rate expression (0.6-2.6 atm), applicable over the temperature range 400-1050 K, was obtained: k₃ (1/s) = 8.13 × 10⁻¹² (T)(7.83) exp(-14598 K/T).

  4. Specific absorption rate determination of magnetic nanoparticles through hyperthermia measurements in non-adiabatic conditions

    Science.gov (United States)

    Coïsson, M.; Barrera, G.; Celegato, F.; Martino, L.; Vinai, F.; Martino, P.; Ferraro, G.; Tiberto, P.

    2016-10-01

    An experimental setup for magnetic hyperthermia operating in non-adiabatic conditions is described. A thermodynamic model that takes into account the heat exchanged by the sample with the surrounding environment is developed. A suitable calibration procedure is proposed that allows the experimental validation of the model. Specific absorption rate can then be accurately determined just from the measurement of the sample temperature at the equilibrium steady state. The setup and the measurement procedure represent a simplification with respect to other systems requiring calorimeters or crucial corrections for heat flow. Two families of magnetic nanoparticles, one superparamagnetic and one characterised by larger sizes and static hysteresis, have been characterised as a function of field intensity, and specific absorption rate and intrinsic loss power have been obtained.

  5. Effects of carbachol matching oral fluid resuscitation on intestinal mucosa blood flow and absorption rate of dogs suffered hemorrhagic shock

    Directory of Open Access Journals (Sweden)

    Lin LI

    2011-04-01

    Full Text Available Objective To investigate the effects of carbachol matching oral fluid resuscitation on intestinal mucosa blood flow(IMBF and intestinal absorption rate of dogs suffered hemorrhagic shock.Methods Twenty-four hours after a preliminary intubation of carotid artery,jugular vein and jejunum by asepsis,twelve Beagle dogs were subjected to a loss of 40% total blood volume to establish animal model of hemorrhagic shock.Animals were then divided into oral resuscitation group and carbachol group(6 each.Dogs in oral resuscitation group were given by gastric tube the glucose-electrolyte solution(GES,which was 3 times volume of blood loss,within 24h after bleeding;while dogs in carbachol group were given GES added carbachol(0.25μg/kg.The IMBF and intestinal absorption rate of water before hemorrhage(0h and 2,4 and 8h after hemorrhage were measured.All the animals were sacrificed at 8h after hemorrhage to record the intestinal GES volume.Results The intestinal absorption rate of water remarkably decreased after hemorrhage in both groups,while in carbachol,group it was obviously higher than that in oral resuscitation group(P < 0.05.The GES volume absorbed by intestine in carbachol group was high than that in oral resuscitation group 8h after hemorrhage(P < 0.05.The IMBF decreased significantly in the both groups after hemorrhage,and then increased gradually 2h after hemorrhage.The IMBF in carbachol group was obviously higher than that in oral resuscitation group(P < 0.05.Conclusion Carbachol in oral resuscitation with GES can improve intestinal absorption rate of water and GES,and increase IMBF in dogs with 40% blood loss.

  6. Absorption Cross-section and Decay Rate of Rotating Linear Dilaton Black Holes

    CERN Document Server

    Sakalli, I

    2016-01-01

    We analytically study the scalar perturbation of non-asymptotically flat (NAF) rotating linear dilaton black holes (RLDBHs) in 4-dimensions. We show that both radial and angular wave equations can be solved in terms of the hypergeometric functions. The exact greybody factor (GF), the absorption cross-section (ACS), and the decay rate (DR) for the massless scalar waves are computed for these black holes (BHs). The results obtained for ACS and DR are discussed through graphs.

  7. Absorption cross-section and decay rate of rotating linear dilaton black holes

    Science.gov (United States)

    Sakalli, I.; Aslan, O. A.

    2016-02-01

    We analytically study the scalar perturbation of non-asymptotically flat (NAF) rotating linear dilaton black holes (RLDBHs) in 4-dimensions. We show that both radial and angular wave equations can be solved in terms of the hypergeometric functions. The exact greybody factor (GF), the absorption cross-section (ACS), and the decay rate (DR) for the massless scalar waves are computed for these black holes (BHs). The results obtained for ACS and DR are discussed through graphs.

  8. Specific absorption rate determination of magnetic nanoparticles through hyperthermia measurements in non-adiabatic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Coïsson, M. [INRIM, strada delle Cacce 91, 10135 Torino (Italy); Barrera, G. [INRIM, strada delle Cacce 91, 10135 Torino (Italy); University of Torino, Chemistry Department, via P. Giuria 7, 10125 Torino (Italy); Celegato, F.; Martino, L.; Vinai, F. [INRIM, strada delle Cacce 91, 10135 Torino (Italy); Martino, P. [Politronica srl, via Livorno 60, 10144 Torino (Italy); Ferraro, G. [Center for Space Human Robotics, Istituto Italiano di Tecnologia - IIT, corso Trento 21, 10129 Torino (Italy); Tiberto, P. [INRIM, strada delle Cacce 91, 10135 Torino (Italy)

    2016-10-01

    An experimental setup for magnetic hyperthermia operating in non-adiabatic conditions is described. A thermodynamic model that takes into account the heat exchanged by the sample with the surrounding environment is developed. A suitable calibration procedure is proposed that allows the experimental validation of the model. Specific absorption rate can then be accurately determined just from the measurement of the sample temperature at the equilibrium steady state. The setup and the measurement procedure represent a simplification with respect to other systems requiring calorimeters or crucial corrections for heat flow. Two families of magnetic nanoparticles, one superparamagnetic and one characterised by larger sizes and static hysteresis, have been characterised as a function of field intensity, and specific absorption rate and intrinsic loss power have been obtained. - Highlights: • Development and thermodynamic modelling of a hyperthermia setup operating in non-adiabatic conditions. • Calibration of the experimental setup and validation of the model. • Accurate measurement of specific absorption rate and intrinsic loss power in non-adiabatic conditions.

  9. Highly sensitive detection using Herriott cell for laser absorption spectroscopy

    Science.gov (United States)

    Zhao, Chongyi; Song, Guangming; Du, Yang; Zhao, Xiaojun; Wang, Wenju; Zhong, Liujun; Hu, Mai

    2016-11-01

    The tunable diode laser absorption spectroscopy combined with the long absorption path technique is a significant method to detect harmful gas. The long optical path could come true by Herriott cell reducing the size of the spectrometers. A 15 cm long Herriott cell with 28.8 m optical absorption path after 96 times reflection was designed that enhanced detection sensitivity of absorption spectroscopy. According to the theory data of calculation, Herriott cell is analyzed and simulated by softwares Matlab and Lighttools.

  10. High Performance Drying System Using Absorption Temperature Amplifier

    Science.gov (United States)

    Nishimura, Nobuya; Nomura, Tomohiro; Yabushita, Akihiro; Kashiwagi, Takao

    A computer simulation has been developed on transient drying process in order to predict the dynamic thermal performance of a new superheated steam drying system using an absorption type temperature amplifier as a steam superheater. A feature of this drying system is that one can reuse the exhausted superheated stream conventionally discharged from the dryer as a driving heat source for the generator in this heat pump. But in the transient drying process, the evaporation of moisture sharply decreases. Accordingly, it is hardly expected to reuse an exhausted superheated steam as heating source for the generator. 80 the effects of this exhausted superheated steam and of changes in hot water and the cooling water temperatures were mainly investigated checking whether this drying system can be driven directly by the low level energy of sun or waste heat. Furthermore, the system performances of this drying system were evaluated on a qualitative-basis by using the exergy efficiency. The results show that, under the transient drying conditions, the temperature boost of superheated steam is possible at a high temperature and thus the absorption type temperature amplifier can be an effective steam superheater system.

  11. Influence of light absorption rate by Nannochloropsis oculata on triglyceride production during nitrogen starvation.

    Science.gov (United States)

    Kandilian, Razmig; Pruvost, Jérémy; Legrand, Jack; Pilon, Laurent

    2014-07-01

    This study aims to understand the role of light transfer in triglyceride fatty-acid (TG-FA) cell content and productivity from microalgae during nitrogen starvation. Large amounts of TG-FA can be produced via nitrogen starvation of microalgae in photobioreactors exposed to intense light. First, spectral absorption and scattering cross-sections of N. oculata were measured at different times during nitrogen starvation. They were used to relate the mean volumetric rate of energy absorption (MVREA) per unit mass of microalgae to the TG-FA productivity and cell content. TG-FA productivity correlated with the MVREA and reached a maximum for MVREA of 13 μmol hν/gs. This indicated that TG-FA synthesis was limited by the photon absorption rate in the PBR. A minimum MVREA of 13 μmol hν/gs was also necessary at the onset of nitrogen starvation to trigger large accumulation of TG-FA in cells. These results will be instrumental in defining protocols for TG-FA production in scaled-up photobioreactors.

  12. New constraints in absorptive capacity and the optimum rate of petroleum output

    Energy Technology Data Exchange (ETDEWEB)

    El Mallakh, R

    1980-01-01

    Economic policy in four oil-producing countries is analyzed within a framework that combines a qualitative assessment of the policy-making process with an empirical formulation based on historical and current trends in these countries. The concept of absorptive capacity is used to analyze the optimum rates of petroleum production in Iran, Iraq, Saudi Arabia, and Kuwait. A control solution with an econometric model is developed which is then modified for alternative development strategies based on analysis of factors influencing production decisions. The study shows the consistencies and inconsistencies between the goals of economic growth, oil production, and exports, and the constraints on economic development. Simulation experiments incorporated a number of the constraints on absorptive capacity. Impact of other constraints such as income distribution and political stability is considered qualitatively. (DLC)

  13. Determination of methane emission rates on a biogas plant using data from laser absorption spectrometry.

    Science.gov (United States)

    Groth, Angela; Maurer, Claudia; Reiser, Martin; Kranert, Martin

    2015-02-01

    The aim of the work was to establish a method for emission control of biogas plants especially the observation of fugitive methane emissions. The used method is in a developmental stage but the topic is crucial to environmental and economic issues. A remote sensing measurement method was adopted to determine methane emission rates of a biogas plant in Rhineland-Palatinate, Germany. An inverse dispersion model was used to deduce emission rates. This technique required one concentration measurement with an open path tunable diode laser absorption spectrometer (TDLAS) downwind and upwind the source and basic wind information, like wind speed and direction. Different operating conditions of the biogas plant occurring on the measuring day (December 2013) could be represented roughly in the results. During undisturbed operational modes the methane emission rate averaged 2.8 g/s, which corresponds to 4% of the methane gas production rate of the biogas plant.

  14. Carbonation Coefficients from Concrete Made with High-Absorption Limestone Aggregate

    Directory of Open Access Journals (Sweden)

    Eric I. Moreno

    2013-01-01

    Full Text Available Normal aggregates employed in concrete have absorption levels in the range of 0.2% to 4% for coarse aggregate and 0.2 to 2% for fine aggregate. However, some aggregates have absorption levels above these values. As the porosity of concrete is related to the porosity of both the cement paste and the aggregate and the carbonation rate is a function, among other things, of the porosity of the material, there is concern about the effect of this high porosity material in achieving good quality concrete from the durability point of view. Thus, the objective of this investigation was to study the carbonation rates of concrete specimens made with high-absorption limestone aggregate. Four different water/cement ratios were used, and cylindrical concrete specimens were exposed to accelerated carbonation. High porosity values were obtained for concrete specimens beyond the expected limits for durable concrete. However, carbonation coefficients related to normal quality concrete were obtained for the lowest water/cement ratio employed suggesting that durable concrete may be obtained with this material despite the high porosity.

  15. Implications for High Energy Blazar Spectra from Intergalactic Absorption Calculations

    Science.gov (United States)

    Stecker, F

    2008-01-01

    Given a knowledge of the density spectra intergalactic low energy photons as a function of redshift, one can derive the intrinsic gamma-ray spectra and luminosities of blazars over a range of redshifts and look for possible trends in blazar evolution. Stecker, Baring & Summerlin have found some evidence hinting that TeV blazars with harder spectra have higher intrinsic TeV gamma-ray luminosities and indicating that there may be a correlation of spectral hardness and luminosity with redshift. Further work along these lines, treating recent observations of the blazers lES02291+200 and 3C279 in the TeV and sub-TeV energy ranges, has recently been explored by Stecker & Scully. GLAST will observe and investigate many blazars in the GeV energy range and will be sensitive to blazers at higher redshifts. I examine the implications high redshift gamma-ray absorption for both theoretical and observational blazer studies.

  16. High Resolution Absorption Spectroscopy using Externally Dispersed Interferometry

    Energy Technology Data Exchange (ETDEWEB)

    Edelstein, J; Erskine, D J

    2005-07-06

    We describe the use of Externally Dispersed Interferometry (EDI) for high-resolution absorption spectroscopy. By adding a small fixed-delay interferometer to a dispersive spectrograph, a precise fiducial grid in wavelength is created over the entire spectrograph bandwidth. The fiducial grid interacts with narrow spectral features in the input spectrum to create a moire pattern. EDI uses the moire pattern to obtain new information about the spectra that is otherwise unavailable, thereby improving spectrograph performance. We describe the theory and practice of EDI instruments and demonstrate improvements in the spectral resolution of conventional spectrographs by a factor of 2 to 6. The improvement of spectral resolution offered by EDI can benefit space instruments by reducing spectrograph size or increasing instantaneous bandwidth.

  17. Durability Indicators in High Absorption Recycled Aggregate Concrete

    Directory of Open Access Journals (Sweden)

    Luis F. Jiménez

    2015-01-01

    Full Text Available The use of recycled aggregates in structural concrete production has the inconvenience of increasing the fluid transport properties, such as porosity, sorptivity, and permeability, which reduces the resistance against penetration of environmental loads such as carbon dioxide and chloride ion. In this paper, behavior of ten concrete mixtures with different percentages of coarse aggregate replacement was studied. The recycled material was recovered by crushing of concrete rubble and had high absorption values. The results showed that it is possible to achieve good resistance to carbonation and chloride penetration with up to 50% replacement of recycled coarse aggregate for 0.5 water/cement ratio. Finally, new indexes for porosity and sorptivity were proposed to assess the quality of concrete.

  18. Specific absorption rate calculations of magnetite, using a modified linear response model for applications in magnetic hyperthermia

    Energy Technology Data Exchange (ETDEWEB)

    Hernández S, A., E-mail: h.s.alfonso@gmail.com, E-mail: meduardo2001@hotmail.com; Cano, M. E., E-mail: h.s.alfonso@gmail.com, E-mail: meduardo2001@hotmail.com [Centro Universitario de la Ciénega, Universidad de Guadalajara, Ocotlán, Jalisco (Mexico); Torres-Arenas, J., E-mail: torresare@gmail.com [Division de Ciencias e Ingenierías, Universidad de Guanajuato, León, Guanajuato (Mexico)

    2014-11-07

    Currently the absorption of electromagnetic radiation by magnetic nanoparticles is studied for biomedical applications of cancer thermotherapy. Several experiments are conduced following the framework of the Rosensweig model, in order to estimate their specific absorption rate. Nevertheless, this linear approximation involves strong simplifications which constrain their accuracy and validity range. The main aim of this work is to incorporate the deviation of the sphericity assumption in particles shapes, to improve the determination of their specific absorption rate. The correction to the effective particles volume is computed as a measure of the apparent amount of magnetic material, interacting with the external AC magnetic field. Preliminary results using the physical properties of Fe3O4 nanoparticles, exhibit an important correction in their estimated specific absorption rate, as a function of the apparent mean particles radius. Indeed, we have observed using a small deviation (6% of the apparent radius), up to 40% of the predicted specific absorption rate by the Rosensweig linear approximation.

  19. Dependence of dose coefficients for {sup 239}Pu on transfer rates and absorption parameters

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, K.; Sekimoto, H. [Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, Tokyo (Japan); Ishigure, N. [Division of Radiotoxicology and Protection, National Institute of Radiological Sciences, Chiba (Japan)

    2000-05-01

    As it is reported of the biokinetic models and parameter values of the International Commission on Radiological Protection (ICRP) for dose estimation have uncertainties owing to insufficiency of human data. For most radionuclides, the data underlying such models and parameters of ICRP usually depend on animal experiments. Moreover, these values or model parameter are also greatly different between mammalian species. Recently, various radiation protection organizations are considering the biokinetic uncertainties from standpoints of data's sources, quality and completeness. In practice, a sensitivity analysis of doses to parameters is significant for the purpose of risk assessment. In general, movement or material in the body is depicted as a system of first-order processes, and parameter values are expressed as transfer rates between compartments. In this study, we made a code to reproduce the ICRP's dose coefficients for {sup 239}Pu, which is one of the most important elements for occupational exposure and its effective dose is much concerned with its own distribution in the body for dominance of alpha-decay. By using this code, we modified each transfer rate in a factor of 2, 3 and 4 in order to evaluate the effects, and calculated the sensitivities of effective doses due to these changes. Additionally, we examined the effects of modification of absorption parameters f{sub r}, S{sub r} and S{sub s}, which represent the absorption of particles from respiratory tract into blood. Consequently, the transfer rates that give a large sensitivity were specified, and it was shown that changes of transfer rates and absorption parameters are not so influential on effective doses for {sup 239}Pu in many cases. (author)

  20. Autism's 'Worryingly' High Suicide Rates Spur Conference

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_165946.html Autism's 'Worryingly' High Suicide Rates Spur Conference Signs of ... News) -- High rates of suicide among people with autism are drawing specialists to a conference this week ...

  1. High durability solar absorptive coating and methods for making same

    Energy Technology Data Exchange (ETDEWEB)

    Hall, Aaron C.; Adams, David P.

    2016-11-22

    The present invention relates to solar absorptive coatings including a ceramic material. In particular, the coatings of the invention are laser-treated to further enhance the solar absorptivity of the material. Methods of making and using such materials are also described.

  2. Combined acquisition technique (CAT for neuroimaging of multiple sclerosis at low specific absorption rates (SAR.

    Directory of Open Access Journals (Sweden)

    Armin Biller

    Full Text Available PURPOSE: To compare a novel combined acquisition technique (CAT of turbo-spin-echo (TSE and echo-planar-imaging (EPI with conventional TSE. CAT reduces the electromagnetic energy load transmitted for spin excitation. This radiofrequency (RF burden is limited by the specific absorption rate (SAR for patient safety. SAR limits restrict high-field MRI applications, in particular. MATERIAL AND METHODS: The study was approved by the local Medical Ethics Committee. Written informed consent was obtained from all participants. T2- and PD-weighted brain images of n = 40 Multiple Sclerosis (MS patients were acquired by CAT and TSE at 3 Tesla. Lesions were recorded by two blinded, board-certificated neuroradiologists. Diagnostic equivalence of CAT and TSE to detect MS lesions was evaluated along with their SAR, sound pressure level (SPL and sensations of acoustic noise, heating, vibration and peripheral nerve stimulation. RESULTS: Every MS lesion revealed on TSE was detected by CAT according to both raters (Cohen's kappa of within-rater/across-CAT/TSE lesion detection κCAT = 1.00, at an inter-rater lesion detection agreement of κLES = 0.82. CAT reduced the SAR burden significantly compared to TSE (p<0.001. Mean SAR differences between TSE and CAT were 29.0 (± 5.7 % for the T2-contrast and 32.7 (± 21.9 % for the PD-contrast (expressed as percentages of the effective SAR limit of 3.2 W/kg for head examinations. Average SPL of CAT was no louder than during TSE. Sensations of CAT- vs. TSE-induced heating, noise and scanning vibrations did not differ. CONCLUSION: T2-/PD-CAT is diagnostically equivalent to TSE for MS lesion detection yet substantially reduces the RF exposure. Such SAR reduction facilitates high-field MRI applications at 3 Tesla or above and corresponding protocol standardizations but CAT can also be used to scan faster, at higher resolution or with more slices. According to our data, CAT is no more uncomfortable than TSE scanning.

  3. A simple parameterization of ozone infrared absorption for atmospheric heating rate calculations

    Science.gov (United States)

    Rosenfield, Joan E.

    1991-01-01

    A simple parameterization of ozone absorption in the 9.6-micron region which is suitable for two- and three-dimensional stratospheric and tropospheric models is presented. The band is divided into two parts, a brand center region and a band wing region, grouping together regions for which the temperature dependence of absorption is similar. Each of the two regions is modeled with a function having the form of the Goody random model, with pressure and temperature dependent band parameters chosen by empirically fitting line-by-line equivalent widths for pressures between 0.25 and 1000 mbar and ozone absorber amounts between 1.0 x 10 to the -7th and 1.0 cm atm. The model has been applied to calculations of atmospheric heating rates using an absorber amount weighted mean pressure and temperature along the inhomogeneous paths necessary for flux computations. In the stratosphere, maximum errors in the heating rates relative to line-by-line calculations are 0.1 K/d, or 5 percent of the peak cooling at the stratopause. In the troposphere the errors are at most 0.005 K/d.

  4. The modification of specific absorption rates in interstitial microwave hyperthermia via tissue-equivalent material bolus.

    Science.gov (United States)

    Sundararaman, S; Denman, D L; Legorreta, R A; Foster, A E; Redmond, K P; Elson, H R; Born, A M; Samaratunga, R C; Lewis, G C; Kereiakes, J G

    1990-09-01

    Patterns of specific absorption rates generated by interstitial, microwave antenna arrays must be experimentally ascertained and quantified to facilitate their clinical incorporation. Phantom studies involved the use of four single-gap, coaxial antennas oriented in a 2 cm square array. These dipoles were driven in phase by a microwave generator at a frequency of 915 MHz. The inherent limitations in modifying the specific absorption rate patterns were addressed with the addition of bolus to the phantom. These additions of Guy's muscle tissue-equivalent material were made either proximal or distal to the phantom proper. Experiments conducted in the presence and absence of tissue-equivalent material bolus showed the ability to achieve broader bands of 50% power deposition in certain bolus conditions. These heating patterns were sufficiently reproducible and predictable to warrant clinical application of the bolus addition. A through-and-through method of catheter implantation allowed for bolus addition when deemed necessary. Treatments with veterinary and human patients using the bolus method to modify heating patterns yielded augmented patterns of power deposition. The effective length of the antennas that would radiate efficiently was essentially broadened via introduction of a microwave-interacting medium. As a result of the tissue equivalent material's ability to absorb microwave power, it was necessary to interpose minimally-interactive styrofoam spacers to limit heat transfer effects at the tissue-bolus interfaces.

  5. High power laser heating of low absorption materials

    Energy Technology Data Exchange (ETDEWEB)

    Olson, K.; Talghader, J., E-mail: joey@umn.edu [Electrical Engineering, University of Minnesota, Minneapolis, Minnesota 55455 (United States); Ogloza, A. [Naval Postgraduate School, 1 University Cir, Monterey, California 93943 (United States); Thomas, J. [Electro Optics Center, Pennsylvania State University, 222 Northpointe Blvd., Freeport, Pennsylvania 16229 (United States)

    2014-09-28

    A model is presented and confirmed experimentally that explains the anomalous behavior observed in continuous wave (CW) excitation of thermally isolated optics. Distributed Bragg Reflector (DBR) high reflective optical thin film coatings of HfO₂ and SiO₂were prepared with a very low absorption, about 7 ppm, measured by photothermal common-path interferometry. When illuminated with a 17 kW CW laser for 30 s, the coatings survived peak irradiances of 13 MW/cm², on 500 μm diameter spot cross sections. The temperature profile of the optical surfaces was measured using a calibrated thermal imaging camera for illuminated spot sizes ranging from 500 μm to 5 mm; about the same peak temperatures were recorded regardless of spot size. This phenomenon is explained by solving the heat equation for an optic of finite dimensions and taking into account the non-idealities of the experiment. An analytical result is also derived showing the relationship between millisecond pulse to CW laser operation where (1) the heating is proportional to the laser irradiance (W/m²) for millisecond pulses, (2) the heating is proportional to the beam radius (W/m) for CW, and (3) the heating is proportional to W/m∙ tan⁻¹(√(t)/m) in the transition region between the two.

  6. Understanding High Rate Behavior Through Low Rate Analog

    Science.gov (United States)

    2014-04-28

    Dioh, N.N., et al., The High-Strain Rate Behavior of Polymers. Journal De Physique Iv, 1994. 4(C8): p. 119-124. 21. Dioh, N.N., P.S. Leevers, and J.G...constitutive response of polymeric materials as a function of temperature and strain rate. Journal De Physique Iv, 2003. 110: p. 27-32. 23. Brown, E.N...properties of polycarbonate under dynamic loading. Journal De Physique Iv, 2003. 110: p. 159-164. 56. Li, Z.H. and J. Lambros, Strain rate effects on the

  7. C (max) and t (max) verification using Fibonacci sequence and absorption rate.

    Science.gov (United States)

    Grabowski, Tomasz; Jaroszewski, Jerzy J; Borucka, Beata; Ziółkowski, Hubert

    2013-06-01

    The aim of this study was to verify the values of maximal observed concentration (C max,obs) and the time, at which maximum concentration is observed (t max,obs) using the analysis of the absorption rate constant (k ab). It focused on the changes in concentration over time (C-T) for drugs, for which several peaks of concentration occur. In addition, the attempt was made to use Fibonacci sequence to facilitate the visual analysis of the dynamics in changes of concentration on C-T graphs. The analyses were conducted with the use of three hypothetical data groups (groups I, II and III), which had distinct C-T profiles, and with the in vivo data form healthy subjects (n = 10) taking part in a bioequivalence study, who was given a single oral dose of topiramate (100 mg). The comparison of hypothetical and real in vivo data demonstrated that for the C-T curves, in which there are several peaks of concentration C max,obs and t max,obs values can easily be miscalculated when the increase in concentration is not properly related to the appropriate absorption phase (63.2, 87.50, 96.88 %). It was also demonstrated that the data transformation with the use of Fibonacci sequence exposes slight differences in the observed concentration values in a semi-logarithmic scale. The results of this study show that in case of C-T curves with several peaks of concentration, the verification of C max and t max data obtained taking into account different absorption phases enables more precise evaluation of these parameters.

  8. Aquaporins in ovine amnion: responses to altered amniotic fluid volumes and intramembranous absorption rates.

    Science.gov (United States)

    Cheung, Cecilia Y; Anderson, Debra F; Brace, Robert A

    2016-07-01

    Aquaporins (AQPs) are transmembrane channel proteins that facilitate rapid water movement across cell membranes. In amniotic membrane, the AQP-facilitated transfer of water across amnion cells has been proposed as a mechanism for amniotic fluid volume (AFV) regulation. To investigate whether AQPs modulate AFV by altering intramembranous absorption (IMA) rate, we tested the hypothesis that AQP gene expression in the amnion is positively correlated with IMA rate during experimental conditions when IMA rate and AFV are modified over a wide range. The relative abundances of AQP1, AQP3, AQP8, AQP9, and AQP11 mRNA and protein were determined in the amnion of 16 late-gestation ovine fetuses subjected to 2 days of control conditions, urine drainage, urine replacement, or intraamniotic fluid infusion. AQP mRNA levels were determined by RT-qPCR and proteins by western immunoblot. Under control conditions, mRNA levels among the five AQPs differed more than 20-fold. During experimental treatments, mean IMA rate in the experimental groups ranged from 100 ± 120 mL/day to 1370 ± 270 mL/day. The mRNA levels of the five AQPs did not change from control and were not correlated with IMA rates. The protein levels of AQP1 were positively correlated with IMA rates (r(2) = 38%, P = 0.01) while the remaining four AQPs were not. These findings demonstrate that five AQPs are differentially expressed in ovine amnion. Our study supports the hypothesis that AQP1 may play a positive role in regulating the rate of fluid transfer across the amnion, thereby participating in the dynamic regulation of AFV.

  9. Alligators and Crocodiles Have High Paracellular Absorption of Nutrients, But Differ in Digestive Morphology and Physiology.

    Science.gov (United States)

    Tracy, Christopher R; McWhorter, Todd J; Gienger, C M; Starck, J Matthias; Medley, Peter; Manolis, S Charlie; Webb, Grahame J W; Christian, Keith A

    2015-12-01

    previously seen only in small birds and bats. Analyses of absorption rates suggested a relatively high proportional contribution of paracellular (i.e., non-mediated) uptake to total uptake of nutrients in both species. Because we measured juveniles, and most paracellular studies to date have been on adults, it is unclear whether high paracellular absorption is generally high within crocodilians or whether these high values are specific to juveniles.

  10. Magnetization and Specific Absorption Rate Studies of Ball-Milled Iron Oxide Nanoparticles for Biomedicine

    Directory of Open Access Journals (Sweden)

    P. Burnham

    2013-01-01

    Full Text Available Comparative studies are presented of iron oxide nanoparticles in the 7–15 nm average diameter range ball milled in hexane in the presence of oleic acid. Transmission electron microscopy identified spherical particles of decreasing size as milling time and/or surfactant concentration increased. Micromagnetic characterization via Mössbauer spectroscopy at room temperature yielded broadened magnetic spectroscopic signatures, while macromagnetic characterization via vibrating sample magnetometry of 7-8 nm diameter particles showed largely superparamagnetic behavior at room temperature and hysteretic at 2 K. Zero-field and field-cooled magnetization curves exhibited a broad maximum at ~215 K indicating the presence of strong interparticle magnetic interactions. The specific absorption rates of ferrofluids based on these nanoparticle preparations were measured in order to test their efficacies as hyperthermia agents.

  11. Adiabatic vs. non-adiabatic determination of specific absorption rate of ferrofluids

    Energy Technology Data Exchange (ETDEWEB)

    Natividad, Eva [Instituto de Ciencia de Materiales de Aragon (CSIC-Universidad de Zaragoza), Sede Campus Rio Ebro, Maria de Luna, 3, 50018 Zaragoza (Spain); Castro, Miguel [Instituto de Ciencia de Materiales de Aragon (CSIC-Universidad de Zaragoza), Sede Campus Rio Ebro, Maria de Luna, 3, 50018 Zaragoza (Spain)], E-mail: mcastro@unizar.es; Mediano, Arturo [Grupo de Electronica de Potencia y Microelectronica (GEPM), Instituto de Investigacion en Ingenieria de Aragon (Universidad de Zaragoza), Maria de Luna, 3, 50018 Zaragoza (Spain)

    2009-05-15

    The measurement of temperature variations in adiabatic conditions allows the determination of the specific absorption rate of magnetic nanoparticles and ferrofluids from the correct incremental expression, SAR=(1/m{sub MNP})C({delta}T/{delta}t). However, when measurements take place in non-adiabatic conditions, one must approximate this expression by SAR{approx}C{beta}/m{sub MNP}, where {beta} is the initial slope of the temperature vs. time curve during alternating field application. The errors arising from the use of this approximation were estimated through several experiments with different isolating conditions, temperature sensors and sample-sensor contacts. It is concluded that small to appreciable errors can appear, which are difficult to infer or control.

  12. Magnetic and solar effects on ionospheric absorption at high latitude

    Directory of Open Access Journals (Sweden)

    M. Pietrella

    2002-06-01

    Full Text Available Some periods of intense solar events and of strong magnetic storms have been selected and their effects on the ionospheric D region have been investigated on the basis of ionospheric absorption data derived from riometer measurements made at the Italian Antarctic Base of Terra Nova Bay (geographic coordinates: 74.69 S, 164.12 E; geomagnetic coordinates: 77.34 S, 279.41 E. It was found that sharp increases in ionospheric absorption are mainly due to solar protons emission with an energy greater than 10 MeV. Moreover, the day to night ratios of the ionospheric absorption are greater than 2 in the case of strong events of energetic protons emitted by the Sun, while during magnetic storms, these ratios range between 1 and 2.

  13. High light transmission through thin absorptive corrugated films.

    Science.gov (United States)

    Dmitruk, Nicolas L; Korovin, Alexander V

    2008-05-01

    The enhancement of light transmittance through periodically relief thin absorptive film at surface plasmon polariton excitation conditions, as a function of relief interrelation, was considered theoretically. Our calculation of transmittance-reflectance through periodically relief thin absorptive film was performed in the framework of differential formalism. There are two basic relief interrelation forms, namely, correlated and anticorrelated ones. The obtained spectral and angular dependencies demonstrate an essential increase of surface plasmon polariton peaks in the case of anticorrelated corrugation of film in comparison with the correlated ones.

  14. Passive Vibration Absorption for Extremely High Density Recording

    NARCIS (Netherlands)

    Vakis, Antonis I.; Polycarpou, Andreas A.

    2012-01-01

    A method is proposed for passive vibration absorption in hard-disk drives during transient events such as the coming into proximity of the rotating disk within the context of thermal fly-height control nanotechnology or external shock. The method uses a nonlinear energy sink at the center of mass of

  15. High burn rate solid composite propellants

    Science.gov (United States)

    Manship, Timothy D.

    High burn rate propellants help maintain high levels of thrust without requiring complex, high surface area grain geometries. Utilizing high burn rate propellants allows for simplified grain geometries that not only make production of the grains easier, but the simplified grains tend to have better mechanical strength, which is important in missiles undergoing high-g accelerations. Additionally, high burn rate propellants allow for a higher volumetric loading which reduces the overall missile's size and weight. The purpose of this study is to present methods of achieving a high burn rate propellant and to develop a composite propellant formulation that burns at 1.5 inches per second at 1000 psia. In this study, several means of achieving a high burn rate propellant were presented. In addition, several candidate approaches were evaluated using the Kepner-Tregoe method with hydroxyl terminated polybutadiene (HTPB)-based propellants using burn rate modifiers and dicyclopentadiene (DCPD)-based propellants being selected for further evaluation. Propellants with varying levels of nano-aluminum, nano-iron oxide, FeBTA, and overall solids loading were produced using the HTPB binder and evaluated in order to determine the effect the various ingredients have on the burn rate and to find a formulation that provides the burn rate desired. Experiments were conducted to compare the burn rates of propellants using the binders HTPB and DCPD. The DCPD formulation matched that of the baseline HTPB mix. Finally, GAP-plasticized DCPD gumstock dogbones were attempted to be made for mechanical evaluation. Results from the study show that nano-additives have a substantial effect on propellant burn rate with nano-iron oxide having the largest influence. Of the formulations tested, the highest burn rate was a 84% solids loading mix using nano-aluminum nano-iron oxide, and ammonium perchlorate in a 3:1(20 micron: 200 micron) ratio which achieved a burn rate of 1.2 inches per second at 1000

  16. High-Resolution X-ray Emission and X-ray Absorption Spectroscopy

    NARCIS (Netherlands)

    Groot, F.M.F. de

    2000-01-01

    In this review, high-resolution X-ray emission and X-ray absorption spectroscopy will be discussed. The focus is on the 3d transition-metal systems. To understand high-resolution X-ray emission and reso-nant X-ray emission, it is first necessary to spend some time discussing the X-ray absorption

  17. High-Resolution X-ray Emission and X-ray Absorption Spectroscopy

    OpenAIRE

    de Groot, F. M. F.

    2001-01-01

    In this review, high-resolution X-ray emission and X-ray absorption spectroscopy will be discussed. The focus is on the 3d transition-metal systems. To understand high-resolution X-ray emission and reso-nant X-ray emission, it is first necessary to spend some time discussing the X-ray absorption process. Section II discusses 1s X-ray absorption, i.e., the K edges, and section III deals with 2p X-ray absorption, the L edges. X-ray emission is discussed in, respectively, the L edges. X-ray emis...

  18. Comparison of specific absorption rate induced in brain tissues of a child and an adult using mobile phone

    Science.gov (United States)

    Lu, Mai; Ueno, Shoogo

    2012-04-01

    The steady increase of mobile phone usage, especially mobile phones by children, has led to a rising concern about the possible adverse health effects of radio frequency electromagnetic field exposure. The objective of this work is to study whether there is a larger radio frequency energy absorption in the brain of a child compared to that of an adult. For this reason, three high-resolution models, two child head models (6 - and 11-year old) and one adult head model (34-year old) have been used in the study. A finite-difference time-domain method was employed to calculate the specific absorption rate (SAR) in the models from exposure to a generic handset at 1750 MHz. The results show that the SAR distributions in the human brain are age-dependent, and there is a deeper penetration of the absorbed SAR in the child's brain. The induced SAR can be significantly higher in subregions of the child's brain. In all of the examined cases, the SAR values in the brains of a child and an adult are well below the IEEE safety standard.

  19. High frame rate synthetic aperture duplex imaging

    DEFF Research Database (Denmark)

    Stuart, Matthias Bo; Tomov, Borislav Gueorguiev; Pihl, Michael Johannes

    2013-01-01

    aperture flow imaging as demonstrated in this paper. Synthetic aperture, directional beamforming, and cross-correlation are used to produce B-mode and vector velocity images at high frame rates. The frame rate equals the effective pulse repetition frequency of each imaging mode. Emissions for making the B...

  20. High-Rate Receiver Design Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose an initial architectural and preliminary hardware design study for a high-rate receiver capable of decoding modulation suites specified by CCSDS 413.0-G-1...

  1. High-resolution absorption measurements of NH3 at high temperatures: 500–2100cm−1

    DEFF Research Database (Denmark)

    Barton, Emma J.; Yurchenko, Sergei N.; Tennyson, Jonathan

    2015-01-01

    High-resolution absorption spectra of NH3 in the region 500–2100 cm -1 at temperatures up to1027 1C and approximately atmospheric pressure (1013±20 mbar) are measured. NH3 concentrations of 1000 ppm,0.5% and 1% in volume fraction were used in the measurements. Spectra are recorded in high...... temperature gas flow cells using a FourierTransform Infrared (FTIR) spectrometer at a nominal resolution of 0.09cm-1. Measurements at 22.7 °C are compared to high-resolution cross sections available from thePacific Northwest National Laboratory (PNNL). The higher temperature spectra are analysed by comparison...

  2. Evidence of In Vivo Absorption of Lactate and Modulation of Short Chain Fatty Acid Absorption from the Reticulorumen of Non-Lactating Cattle Fed High Concentrate Diets

    Science.gov (United States)

    Qumar, Muhammad; Khiaosa-ard, Ratchaneewan; Pourazad, Poulad; Wetzels, Stefanie U.; Klevenhusen, Fenja; Kandler, Wolfgang; Aschenbach, Jörg R.; Zebeli, Qendrim

    2016-01-01

    Short-chain fatty acids (SCFAs) and lactate are endproducts of rumen fermentation and important energy sources for the host ruminant. Because their rapid accumulation results in ruminal acidosis, enhancement of the absorption of SCFA and lactate across reticuloruminal wall is instrumental in increasing energy supply and preventing ruminal acidosis in cattle. This study investigated whether the reticuloruminal absorption of SCFAs and lactate was altered by different strategies of high concentrate feeding. Eight rumen-cannulated, non-lactating Holstein cows were fed a forage-only diet (baseline) and then gradually adapted over 6 d to a 60% concentrate level. Thereafter, this concentrate-rich diet was fed for 4 wk either continuously (Con; n = 8) or interruptedly (Int; n = 8). Absorption of SCFAs and lactate was determined in vivo from the experimental buffer introduced into the washed reticulorumen. The buffer contained acetate, propionate, butyrate and lactate at a concentration of 60, 30, 10 and 5 mmol/L, respectively and Cr-EDTA as a marker for correcting ruminal water fluxes. The reticuloruminal absorption after 35 and 65 min of buffer incubation was measured at the baseline, after 1 wk of 60% concentrate feeding in the interrupted model (Int-1) and after 4 wk of concentrate feeding in both feeding models (Int-4 and Con-4). Data showed that the absorption rates of individual and total SCFAs during the first 35 min of incubation of Con-4 were highest (~1.7 times compared to baseline), while Int-1 and Int-4 were similar to respective baseline. Lactate was not absorbed during forage-only baseline and 1-wk concentrate feeding, but after 4-wk feeding of concentrates in both models. In conclusion, SCFAs absorption across the reticulorumen of non-lactating cattle was enhanced by the 4-wk continuous concentrate feeding, which seems to be more advantageous in terms of rumen acidosis prevention compared to the interrupted feeding model. The study provides evidence of

  3. CHBr3 (bromoform): Revised UV Absorption Spectrum and Atmospheric Photolysis Rates

    Science.gov (United States)

    Burkholder, J. B.; Papanastasiou, D.; McKeen, S. A.

    2013-12-01

    CHBr3 (bromoform) is a short-lived atmospheric trace compound primarily of natural origin that is a source of reactive bromine in both the troposphere and stratosphere. Estimating the impact of CHBr3 on the environment and its transport to the stratosphere requires a thorough understanding of its atmospheric loss processes, which are primarily UV photolysis and reaction with the OH radical. In this presentation, new measurements of the UV absorption spectrum of CHBr3 will be presented. Spectra were measured at wavelengths between 300 and 345 nm at temperatures between 260 and 330 K using cavity ring-down spectroscopy. The present results will be compared with currently recommended values for use in atmospheric modeling taken from Moortgat et al. [The tropospheric chemistry of ozone in the polar regions, edited by H. Niki and K. H. Becker, Springer-Verlag Berlin Heidelberg, 1993]. The discrepancies and impact on CHBr3 photolysis lifetime will be discussed. A parameterization of the CHBr3 UV spectrum for use in atmospheric models will be presented and local photolysis rate calculations used to highlight the impact of the revised cross section data on local lifetimes and the relative importance of photolysis loss versus reaction with the OH radical. The results from the present study will contribute to a better understanding (and accuracy) of estimates of stratospheric ozone loss due to very short-lived brominated substances.

  4. Assessment of specific energy absorption rate (SAR) in the head from a TETRA handset

    Science.gov (United States)

    Dimbylow, Peter; Khalid, Mohammed; Mann, Simon

    2003-12-01

    Finite-difference time-domain (FDTD) calculations of the specific energy absorption rate (SAR) from a representative TETRA handset have been performed in an anatomically realistic model of the head. TETRA (Terrestrial Trunked Radio) is a modern digital private mobile radio system designed to meet the requirements of professional users, such as the police and fire brigade. The current frequency allocations in the UK are 380-385 MHz and 390-395 MHz for the public sector network. A comprehensive set of calculations of SAR in the head was performed for positions of the handset in front of the face and at both sides of the head. The representative TETRA handset considered, operating at 1 W in normal use, will show compliance with both the ICNIRP occupational and public exposure restrictions. The handset with a monopole antenna operating at 3 W in normal use will show compliance with both the ICNIRP occupational and public exposure restrictions. The handset with a helical antenna operating at 3 W in normal use will show compliance with the ICNIRP occupational exposure restriction but will be over the public exposure restriction by up to ~50% if kept in the position of maximum SAR for 6 min continuously.

  5. High-resolution absorption measurements of NH3 at high temperatures: 2100–5500 cm−1

    DEFF Research Database (Denmark)

    Barton, Emma J.; Yurchenko, Sergei N.; Tennyson, Jonathan

    2017-01-01

    High-resolution absorption spectra of NH3 in the region 2100–5500 cm−1 at 1027 °C and approximately atmospheric pressure (1045±3 mbar) are measured. An NH3 concentration of 10% in volume fraction is used in the measurements. Spectra are recorded in a high-temperature gas-flow cell using a Fourier...... Transform Infrared (FTIR) spectrometer at a nominal resolution of 0.09 cm−1. The spectra are analysed by comparison to a variational line list, BYTe, and experimental energy levels determined using the MARVEL procedure. 2308 lines have been assigned to 45 different bands, of which 1755 and 15 have been...

  6. Understanding High Saving Rate in China

    Institute of Scientific and Technical Information of China (English)

    Xinhua He; Yongfu Cao

    2007-01-01

    This paper presents a detailed analysis of the Chinese saving rate based on the flow of funds data. It finds that the most widely adopted view of precautionary saving, which is regarded as the top reason for maintaining a high saving rate in China, is misleading because this conclusion is drawn from the household survey data. In fact, the household saving rate has declined dramatically since the mid-1990s, as is observed from the flow of funds framework.The high national saving rate is attributed to the increasing shares of both government and corporation disposable incomes. Insufficient consumption demand is caused by the persistent decrease in percentage share of household to national disposable income. Governmentdirected income redistribution urgently needs to be improved to accelerate consumption,which in turn would make the Chinese economy less investment-led and help to reduce the current account surplus.

  7. The effect of sewage sludge application on the growth and absorption rates of Pb and As in water spinach

    Directory of Open Access Journals (Sweden)

    Rong Wang

    2016-01-01

    Full Text Available This paper investigated the effect of the application of sewage sludge on the growth rates and absorption rates of Pb and As in potted water spinach. Our results indicated that application of sewage sludge promoted vegetable growth, and the dry weight of water spinach reached a maximal value (4.38 ± 0.82 g upon 8% sludge application. We also found that the dry weights of water spinach after treatment were all greater than those of the control systems (CK. Treatment with sludge promoted the absorption of Pb and As in water spinach, with a significant (p < 0.05 increase of absorbed Pb following treatment concentrations above 10%, and a peak absorption of As at 8%. Finally, we found that concentrations of Pb and As were higher in rhizosphere-attached soil than in free pot.

  8. A high-strain-rate superplastic ceramic.

    Science.gov (United States)

    Kim, B N; Hiraga, K; Morita, K; Sakka, Y

    2001-09-20

    High-strain-rate superplasticity describes the ability of a material to sustain large plastic deformation in tension at high strain rates of the order of 10-2 to 10-1 s-1 and is of great technological interest for the shape-forming of engineering materials. High-strain-rate superplasticity has been observed in aluminium-based and magnesium-based alloys. But for ceramic materials, superplastic deformation has been restricted to low strain rates of the order of 10-5 to 10-4 s-1 for most oxides and nitrides with the presence of intergranular cavities leading to premature failure. Here we show that a composite ceramic material consisting of tetragonal zirconium oxide, magnesium aluminate spinel and alpha-alumina phases exhibits superplasticity at strain rates up to 1 s-1. The composite also exhibits a large tensile elongation, exceeding 1,050 per cent for a strain rate of 0.4 s-1. The tensile flow behaviour and deformed microstructure of the material indicate that superplasticity is due to a combination of limited grain growth in the constitutive phases and the intervention of dislocation-induced plasticity in the zirconium oxide phase. We suggest that the present results hold promise for the application of shape-forming technologies to ceramic materials.

  9. Electrorheological Effects at High Shear Rate

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Much attention has been given to electrorheological (ER) fluids because of the ER effect, which has been described by a large number of researchers as a notable increase in the apparent viscosity of a fluid upon the application of an electric field. The description of ER effects is, however, not accurate at high shear rates. To clarify the discrepancy, we analyze and compute the apparent viscosity as a function of shear rate for ER fluid flow between rotating coaxial cylinders in the presence of an electric field. The theoretical predictions show that the increase of electric intensity contributes little to the apparent viscosity enhancement at high shear rates, while ER effects for ER fluids with a higher polarization rate still exist and ER devices possess controllability in this regime. Description of the ER effect by the apparent viscosity leads to an unrealistic conclusion that ER effects disappear at high shear rates, because the apparent viscosity of ER fluids approaches the value for Newtonian fluids. Therefore, it is concluded that the proper description of ER effects, i.e., one that holds uniformly for any strain rate when ER effects exist, is manifested by a remarkable increase in the extra stress rather than in the apparent viscosity of ER fluids.

  10. Thrombus Formation at High Shear Rates.

    Science.gov (United States)

    Casa, Lauren D C; Ku, David N

    2017-06-21

    The final common pathway in myocardial infarction and ischemic stroke is occlusion of blood flow from a thrombus forming under high shear rates in arteries. A high-shear thrombus forms rapidly and is distinct from the slow formation of coagulation that occurs in stagnant blood. Thrombosis at high shear rates depends primarily on the long protein von Willebrand factor (vWF) and platelets, with hemodynamics playing an important role in each stage of thrombus formation, including vWF binding, platelet adhesion, platelet activation, and rapid thrombus growth. The prediction of high-shear thrombosis is a major area of biofluid mechanics in which point-of-care testing and computational modeling are promising future directions for clinically relevant research. Further research in this area will enable identification of patients at high risk for arterial thrombosis, improve prevention and treatment based on shear-dependent biological mechanisms, and improve blood-contacting device design to reduce thrombosis risk.

  11. High temperature absorption compression heat pump for industrial waste heat

    DEFF Research Database (Denmark)

    Reinholdt, Lars; Horntvedt, B.; Nordtvedt, S. R.

    2016-01-01

    Heat pumps are currently receiving extensive interest because they may be able to support the integration of large shares of fluctuating electricity production based on renewable sources, and they have the potential for the utilization of low temperature waste heat from industry. In most industries......, the needed temperature levels often range from 100°C and up, but until now, it has been quite difficult to find heat pump technologies that reach this level, and thereby opening up the large-scale heat recovery in the industry. Absorption compression heat pumps can reach temperatures above 100°C......, and they have proved themselves a very efficient and reliable technology for applications that have large temperature changes on the heat sink and/or heat source. The concept of Carnot and Lorenz efficiency and its use in the analysis of system integration is shown. A 1.25 MW system having a Carnot efficiency...

  12. Broad Absorption Line Quasars with Redshifted Troughs: High-Velocity Infall or Rotationally Dominated Outflows?

    CERN Document Server

    Hall, Patrick B; Petitjean, P; Paris, I; Ak, N Filiz; Shen, Yue; Gibson, R R; Aubourg, E; Anderson, S F; Schneider, D P; Bizyaev, D; Brinkmann, J; Malanushenko, E; Malanushenko, V; Myers, A D; Oravetz, D J; Ross, N P; Shelden, A; Simmons, A E; Streblyanska, A; Weaver, B A; York, D G

    2013-01-01

    We report the discovery in the Sloan Digital Sky Survey and the SDSS-III Baryon Oscillation Spectroscopic Survey of seventeen broad absorption line (BAL) quasars with high-ionization troughs that include absorption redshifted relative to the quasar rest frame. The redshifted troughs extend to velocities up to v=12,000 km/s and the trough widths exceed 3000 km/s in all but one case. Approximately 1 in 1000 BAL quasars with blueshifted C IV absorption also has redshifted C IV absorption; objects with C IV absorption present only at redshifted velocities are roughly four times rarer. In more than half of our objects, redshifted absorption is seen in C II or Al III as well as C IV, making low-ionization absorption at least ten times more common among BAL quasars with redshifted troughs than among standard BAL quasars. However, the C IV absorption equivalent widths in our objects are on average smaller than those of standard BAL quasars with low-ionization absorption. We consider several possible ways of generatin...

  13. Effect of microplastic deformation on the electron ultrasonic absorption in high-purity molybdenum monocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Pal' -Val' , P.P.; Kaufmann, Kh.J.

    1983-03-01

    The low temperature (100-6 K) linear absorption of ultrasound (88 kHz) by high purity molybdenum single crystals have been studied. Both unstrained samples and samples sub ected to microplastic deformation (epsilon<=0.45%) were used. Unstrained samples displayed at T<30 K a rapid increase in the absorption with lowering temperature which is interpreted as an indication of electron viscosity due to electron-phonon collisions. After deformation this part of absorption disappeared. This seems to suggest that microplastic deformation brings about in the crystal a sufficiently large number of defects that can compete with phonons in restricting the electron mean free path. A low temperature dynamic annealing has been revealed in strained samples, that is almost complete recovery of the absorption nature under irradiation with high amplitude sound, epsilon/sub 0/ approximately 10/sup -4/, during 10 min, at 6 K. A new relaxation peak of absorption at 10 K has been found in strained samples.

  14. High Strain Rate Characterisation of Composite Materials

    DEFF Research Database (Denmark)

    Eriksen, Rasmus Normann Wilken

    The high strain rate characterisation of FRP materials present the experimenter with a new set of challenges in obtaining valid experimental data. These challenges were addressed in this work with basis in classic wave theory. The stress equilibrium process for linear elastic materials, as fibre...... a linear elastic specimen to reach a state of constant strain rate before fracture. This was in contrast to ductile materials, which are widely tested with for the High-speed servohydraulic test machine. The development of the analysis and the interpretation of the results, were based on the experience...

  15. Fast design of local N-gram-specific absorption rate-optimized radiofrequency pulses for parallel transmit systems

    NARCIS (Netherlands)

    Sbrizzi, Alessandro; Hoogduin, Hans; Lagendijk, Jan J.; Luijten, Peter; Sleijpen, Gerard L. G.; van den Berg, Cornelis A. T.

    2012-01-01

    Designing multidimensional radiofrequency pulses for clinical application must take into account the local specific absorption rate (SAR) as controlling the global SAR does not guarantee suppression of hot spots. The maximum peak SAR, averaged over an N grams cube (local NgSAR), must be kept under c

  16. High Count Rate Electron Probe Microanalysis

    Science.gov (United States)

    Geller, Joseph D.; Herrington, Charles

    2002-01-01

    Reducing the measurement uncertainty of quantitative analyses made using electron probe microanalyzers (EPMA) requires a careful study of the individual uncertainties from each definable step of the measurement. Those steps include measuring the incident electron beam current and voltage, knowing the angle between the electron beam and the sample (takeoff angle), collecting the emitted x rays from the sample, comparing the emitted x-ray flux to known standards (to determine the k-ratio) and transformation of the k-ratio to concentration using algorithms which includes, as a minimum, the atomic number, absorption, and fluorescence corrections. This paper discusses the collection and counting of the emitted x rays, which are diffracted into the gas flow or sealed proportional x-ray detectors. The representation of the uncertainty in the number of collected x rays collected reduces as the number of counts increase. The uncertainty of the collected signal is fully described by Poisson statistics. Increasing the number of x rays collected involves either counting longer or at a higher counting rate. Counting longer means the analysis time increases and may become excessive to get to the desired uncertainty. Instrument drift also becomes an issue. Counting at higher rates has its limitations, which are a function of the detector physics and the detecting electronics. Since the beginning of EPMA analysis, analog electronics have been used to amplify and discriminate the x-ray induced ionizations within the proportional counter. This paper will discuss the use of digital electronics for this purpose. These electronics are similar to that used for energy dispersive analysis of x rays with either Si(Li) or Ge(Li) detectors except that the shaping time constants are much smaller. PMID:27446749

  17. The formation of linear aggregates in magnetic hyperthermia: implications on specific absorption rate and magnetic anisotropy.

    Science.gov (United States)

    Saville, Steven L; Qi, Bin; Baker, Jonathon; Stone, Roland; Camley, Robert E; Livesey, Karen L; Ye, Longfei; Crawford, Thomas M; Mefford, O Thompson

    2014-06-15

    The design and application of magnetic nanoparticles for use as magnetic hyperthermia agents has garnered increasing interest over the past several years. When designing these systems, the fundamentals of particle design play a key role in the observed specific absorption rate (SAR). This includes the particle's core size, polymer brush length, and colloidal arrangement. While the role of particle core size on the observed SAR has been significantly reported, the role of the polymer brush length has not attracted as much attention. It has recently been reported that for some suspensions linear aggregates form in the presence of an applied external magnetic field, i.e. chains of magnetic particles. The formation of these chains may have the potential for a dramatic impact on the biomedical application of these materials, specifically the efficiency of the particles to transfer magnetic energy to the surrounding cells. In this study we demonstrate the dependence of SAR on magnetite nanoparticle core size and brush length as well as observe the formation of magnetically induced colloidal arrangements. Colloidally stable magnetic nanoparticles were demonstrated to form linear aggregates in an alternating magnetic field. The length and distribution of the aggregates were dependent upon the stabilizing polymer molecular weight. As the molecular weight of the stabilizing layer increased, the magnetic interparticle interactions decreased therefore limiting chain formation. In addition, theoretical calculations demonstrated that interparticle spacing has a significant impact on the magnetic behavior of these materials. This work has several implications for the design of nanoparticle and magnetic hyperthermia systems, while improving understanding of how colloidal arrangement affects SAR.

  18. High Resolution Measurement of the Glycolytic Rate

    Science.gov (United States)

    Bittner, Carla X.; Loaiza, Anitsi; Ruminot, Iván; Larenas, Valeria; Sotelo-Hitschfeld, Tamara; Gutiérrez, Robin; Córdova, Alex; Valdebenito, Rocío; Frommer, Wolf B.; Barros, L. Felipe

    2010-01-01

    The glycolytic rate is sensitive to physiological activity, hormones, stress, aging, and malignant transformation. Standard techniques to measure the glycolytic rate are based on radioactive isotopes, are not able to resolve single cells and have poor temporal resolution, limitations that hamper the study of energy metabolism in the brain and other organs. A new method is described in this article, which makes use of a recently developed FRET glucose nanosensor to measure the rate of glycolysis in single cells with high temporal resolution. Used in cultured astrocytes, the method showed for the first time that glycolysis can be activated within seconds by a combination of glutamate and K+, supporting a role for astrocytes in neurometabolic and neurovascular coupling in the brain. It was also possible to make a direct comparison of metabolism in neurons and astrocytes lying in close proximity, paving the way to a high-resolution characterization of brain energy metabolism. Single-cell glycolytic rates were also measured in fibroblasts, adipocytes, myoblasts, and tumor cells, showing higher rates for undifferentiated cells and significant metabolic heterogeneity within cell types. This method should facilitate the investigation of tissue metabolism at the single-cell level and is readily adaptable for high-throughput analysis. PMID:20890447

  19. High resolution measurement of the glycolytic rate

    Directory of Open Access Journals (Sweden)

    Carla X Bittner

    2010-09-01

    Full Text Available The glycolytic rate is sensitive to physiological activity, hormones, stress, aging and malignant transformation. Standard techniques to measure the glycolytic rate are based on radioactive isotopes, are not able to resolve single cells and have poor temporal resolution, limitations that hamper the study of energy metabolism in the brain and other organs. A new method is described in this article, which makes use of a recently-developed FRET glucose nanosensor to measure the rate of glycolysis in single cells with high temporal resolution. Used in cultured astrocytes, the method showed for the first time that glycolysis can be activated within seconds by a combination of glutamate and K+, supporting a role for astrocytes in neurometabolic and neurovascular coupling in the brain. It was also possible to make a direct comparison of metabolism in neurons and astrocytes lying in close proximity, paving the way to a high-resolution characterization of brain energy metabolism. Single-cell glycolytic rates were also measured in fibroblasts, adipocytes, myoblasts and tumor cells, showing higher rates for undifferentiated cells and significant metabolic heterogeneity within cell types. This method should facilitate the investigation of tissue metabolism at the single-cell level and is readily adaptable for high-throughput analysis.

  20. High rate, high reliability Li/SO2 cells

    Science.gov (United States)

    Chireau, R.

    1982-03-01

    The use of the lithium/sulfur dioxide system for aerospace applications is discussed. The high rate density in the system is compared to some primary systems: mercury zinc, silver zinc, and magnesium oxide. Estimates are provided of the storage life and shelf life of typical lithium sulfur batteries. The design of lithium cells is presented and criteria are given for improving the output of cells in order to achieve high rate and high reliability.

  1. Multimodal Superparamagnetic Nanoparticles with Unusually Enhanced Specific Absorption Rate for Synergetic Cancer Therapeutics and Magnetic Resonance Imaging.

    Science.gov (United States)

    Thorat, Nanasaheb D; Bohara, Raghvendra A; Malgras, Victor; Tofail, Syed A M; Ahamad, Tansir; Alshehri, Saad M; Wu, Kevin C-W; Yamauchi, Yusuke

    2016-06-15

    Superparamagnetic nanoparticles (SPMNPs) used for magnetic resonance imaging (MRI) and magnetic fluid hyperthermia (MFH) cancer therapy frequently face trade off between a high magnetization saturation and their good colloidal stability, high specific absorption rate (SAR), and most importantly biological compatibility. This necessitates the development of new nanomaterials, as MFH and MRI are considered to be one of the most promising combined noninvasive treatments. In the present study, we investigated polyethylene glycol (PEG) functionalized La1-xSrxMnO3 (LSMO) SPMNPs for efficient cancer hyperthermia therapy and MRI application. The superparamagnetic nanomaterial revealed excellent colloidal stability and biocompatibility. A high SAR of 390 W/g was observed due to higher colloidal stability leading to an increased Brownian and Neel's spin relaxation. Cell viability of PEG capped nanoparticles is up to 80% on different cell lines tested rigorously using different methods. PEG coating provided excellent hemocompatibility to human red blood cells as PEG functionalized SPMNPs reduced hemolysis efficiently compared to its uncoated counterpart. Magnetic fluid hyperthermia of SPMNPs resulted in cancer cell death up to 80%. Additionally, improved MRI characteristics were also observed for the PEG capped La1-xSrxMnO3 formulation in aqueous medium compared to the bare LSMO. Taken together, PEG capped SPMNPs can be useful for diagnosis, efficient magnetic fluid hyperthermia, and multimodal cancer treatment as the amphiphilicity of PEG can easily be utilized to encapsulate hydrophobic drugs.

  2. Moisture absorption analysis of high performance polyimide adhesive

    NARCIS (Netherlands)

    Akram, M.; Jansen, K.M.B.; Bhowmik, S.; Ernst, L.J.

    2011-01-01

    The high temperature resistant polymers and metal composites are used widely in aviation, space, automotive and electronics industry. The high temperature resistant polymers and metals are joined together using high temperature adhesives. Polyimide and epoxy adhesives that can withstand high tempera

  3. High Rate Performing Li-ion Battery

    Science.gov (United States)

    2015-02-09

    permeable to lithium ions and efficient in transferring the electrons into/from the LVP surface to the corresponding current collector. a) b) c) d) e...PO4)3/C for High Rate Lithium-ion Battery Applications”, Lee Hwang Sheng, Nail Suleimanov, Vishwanathan Ramar, Mangayarkarasi Murugan, Kuppan

  4. [Hopes of high dose-rate radiotherapy].

    Science.gov (United States)

    Fouillade, Charles; Favaudon, Vincent; Vozenin, Marie-Catherine; Romeo, Paul-Henri; Bourhis, Jean; Verrelle, Pierre; Devauchelle, Patrick; Patriarca, Annalisa; Heinrich, Sophie; Mazal, Alejandro; Dutreix, Marie

    2017-04-01

    In this review, we present the synthesis of the newly acquired knowledge concerning high dose-rate irradiations and the hopes that these new radiotherapy modalities give rise to. The results were presented at a recent symposium on the subject. Copyright © 2017. Published by Elsevier Masson SAS.

  5. Understanding High School Graduation Rates in Arizona

    Science.gov (United States)

    Alliance for Excellent Education, 2009

    2009-01-01

    Graduation rates are a fundamental indicator of whether or not the nation's public school system is doing what it is intended to do: enroll, engage, and educate youth to be productive members of society. Since almost 90 percent of the fastest-growing and highest-paying jobs require some postsecondary education, having a high school diploma and the…

  6. Understanding High School Graduation Rates in Delaware

    Science.gov (United States)

    Alliance for Excellent Education, 2009

    2009-01-01

    Graduation rates are a fundamental indicator of whether or not the nation's public school system is doing what it is intended to do: enroll, engage, and educate youth to be productive members of society. Since almost 90 percent of the fastest-growing and highest-paying jobs require some postsecondary education, having a high school diploma and the…

  7. Understanding High School Graduation Rates in Idaho

    Science.gov (United States)

    Alliance for Excellent Education, 2009

    2009-01-01

    Graduation rates are a fundamental indicator of whether or not the nation's public school system is doing what it is intended to do: enroll, engage, and educate youth to be productive members of society. Since almost 90 percent of the fastest-growing and highest-paying jobs require some postsecondary education, having a high school diploma and the…

  8. Understanding High School Graduation Rates in Illinois

    Science.gov (United States)

    Alliance for Excellent Education, 2009

    2009-01-01

    Graduation rates are a fundamental indicator of whether or not the nation's public school system is doing what it is intended to do: enroll, engage, and educate youth to be productive members of society. Since almost 90 percent of the fastest-growing and highest-paying jobs require some postsecondary education, having a high school diploma and the…

  9. Understanding High School Graduation Rates in Massachusetts

    Science.gov (United States)

    Alliance for Excellent Education, 2009

    2009-01-01

    Graduation rates are a fundamental indicator of whether or not the nation's public school system is doing what it is intended to do: enroll, engage, and educate youth to be productive members of society. Since almost 90 percent of the fastest-growing and highest-paying jobs require some postsecondary education, having a high school diploma and the…

  10. Understanding High School Graduation Rates in Pennsylvania

    Science.gov (United States)

    Alliance for Excellent Education, 2009

    2009-01-01

    Graduation rates are a fundamental indicator of whether or not the nation's public school system is doing what it is intended to do: enroll, engage, and educate youth to be productive members of society. Since almost 90 percent of the fastest-growing and highest-paying jobs require some postsecondary education, having a high school diploma and the…

  11. Understanding High School Graduation Rates in Minnesota

    Science.gov (United States)

    Alliance for Excellent Education, 2009

    2009-01-01

    Graduation rates are a fundamental indicator of whether or not the nation's public school system is doing what it is intended to do: enroll, engage, and educate youth to be productive members of society. Since almost 90 percent of the fastest-growing and highest-paying jobs require some postsecondary education, having a high school diploma and the…

  12. Understanding High School Graduation Rates in Kentucky

    Science.gov (United States)

    Alliance for Excellent Education, 2009

    2009-01-01

    Graduation rates are a fundamental indicator of whether or not the nation's public school system is doing what it is intended to do: enroll, engage, and educate youth to be productive members of society. Since almost 90 percent of the fastest-growing and highest-paying jobs require some postsecondary education, having a high school diploma and the…

  13. Understanding High School Graduation Rates in Maryland

    Science.gov (United States)

    Alliance for Excellent Education, 2009

    2009-01-01

    Graduation rates are a fundamental indicator of whether or not the nation's public school system is doing what it is intended to do: enroll, engage, and educate youth to be productive members of society. Since almost 90 percent of the fastest-growing and highest-paying jobs require some postsecondary education, having a high school diploma and the…

  14. Understanding High School Graduation Rates in Wisconsin

    Science.gov (United States)

    Alliance for Excellent Education, 2009

    2009-01-01

    Graduation rates are a fundamental indicator of whether or not the nation's public school system is doing what it is intended to do: enroll, engage, and educate youth to be productive members of society. Since almost 90 percent of the fastest-growing and highest-paying jobs require some postsecondary education, having a high school diploma and the…

  15. Understanding High School Graduation Rates in Wyoming

    Science.gov (United States)

    Alliance for Excellent Education, 2009

    2009-01-01

    Graduation rates are a fundamental indicator of whether or not the nation's public school system is doing what it is intended to do: enroll, engage, and educate youth to be productive members of society. Since almost 90 percent of the fastest-growing and highest-paying jobs require some postsecondary education, having a high school diploma and the…

  16. Understanding High School Graduation Rates in Alaska

    Science.gov (United States)

    Alliance for Excellent Education, 2009

    2009-01-01

    Graduation rates are a fundamental indicator of whether or not the nation's public school system is doing what it is intended to do: enroll, engage, and educate youth to be productive members of society. Since almost 90 percent of the fastest-growing and highest-paying jobs require some postsecondary education, having a high school diploma and the…

  17. Understanding High School Graduation Rates in Oklahoma

    Science.gov (United States)

    Alliance for Excellent Education, 2009

    2009-01-01

    Graduation rates are a fundamental indicator of whether or not the nation's public school system is doing what it is intended to do: enroll, engage, and educate youth to be productive members of society. Since almost 90 percent of the fastest-growing and highest-paying jobs require some postsecondary education, having a high school diploma and the…

  18. Understanding High School Graduation Rates in Tennessee

    Science.gov (United States)

    Alliance for Excellent Education, 2009

    2009-01-01

    Graduation rates are a fundamental indicator of whether or not the nation's public school system is doing what it is intended to do: enroll, engage, and educate youth to be productive members of society. Since almost 90 percent of the fastest-growing and highest-paying jobs require some postsecondary education, having a high school diploma and the…

  19. Understanding High School Graduation Rates in Georgia

    Science.gov (United States)

    Alliance for Excellent Education, 2009

    2009-01-01

    Graduation rates are a fundamental indicator of whether or not the nation's public school system is doing what it is intended to do: enroll, engage, and educate youth to be productive members of society. Since almost 90 percent of the fastest-growing and highest-paying jobs require some postsecondary education, having a high school diploma and the…

  20. Understanding High School Graduation Rates in Iowa

    Science.gov (United States)

    Alliance for Excellent Education, 2009

    2009-01-01

    Graduation rates are a fundamental indicator of whether or not the nation's public school system is doing what it is intended to do: enroll, engage, and educate youth to be productive members of society. Since almost 90 percent of the fastest-growing and highest-paying jobs require some postsecondary education, having a high school diploma and the…

  1. Understanding High School Graduation Rates in Nevada

    Science.gov (United States)

    Alliance for Excellent Education, 2009

    2009-01-01

    Graduation rates are a fundamental indicator of whether or not the nation's public school system is doing what it is intended to do: enroll, engage, and educate youth to be productive members of society. Since almost 90 percent of the fastest-growing and highest-paying jobs require some postsecondary education, having a high school diploma and the…

  2. Understanding High School Graduation Rates in Texas

    Science.gov (United States)

    Alliance for Excellent Education, 2009

    2009-01-01

    Graduation rates are a fundamental indicator of whether or not the nation's public school system is doing what it is intended to do: enroll, engage, and educate youth to be productive members of society. Since almost 90 percent of the fastest-growing and highest-paying jobs require some postsecondary education, having a high school diploma and the…

  3. Understanding High School Graduation Rates in Florida

    Science.gov (United States)

    Alliance for Excellent Education, 2009

    2009-01-01

    Graduation rates are a fundamental indicator of whether or not the nation's public school system is doing what it is intended to do: enroll, engage, and educate youth to be productive members of society. Since almost 90 percent of the fastest-growing and highest-paying jobs require some postsecondary education, having a high school diploma and the…

  4. Understanding High School Graduation Rates in Nebraska

    Science.gov (United States)

    Alliance for Excellent Education, 2009

    2009-01-01

    Graduation rates are a fundamental indicator of whether or not the nation's public school system is doing what it is intended to do: enroll, engage, and educate youth to be productive members of society. Since almost 90 percent of the fastest-growing and highest-paying jobs require some postsecondary education, having a high school diploma and the…

  5. Understanding High School Graduation Rates in Oregon

    Science.gov (United States)

    Alliance for Excellent Education, 2009

    2009-01-01

    Graduation rates are a fundamental indicator of whether or not the nation's public school system is doing what it is intended to do: enroll, engage, and educate youth to be productive members of society. Since almost 90 percent of the fastest-growing and highest-paying jobs require some postsecondary education, having a high school diploma and the…

  6. Understanding High School Graduation Rates in Kansas

    Science.gov (United States)

    Alliance for Excellent Education, 2009

    2009-01-01

    Graduation rates are a fundamental indicator of whether or not the nation's public school system is doing what it is intended to do: enroll, engage, and educate youth to be productive members of society. Since almost 90 percent of the fastest-growing and highest-paying jobs require some postsecondary education, having a high school diploma and the…

  7. Understanding High School Graduation Rates in Virginia

    Science.gov (United States)

    Alliance for Excellent Education, 2009

    2009-01-01

    Graduation rates are a fundamental indicator of whether or not the nation's public school system is doing what it is intended to do: enroll, engage, and educate youth to be productive members of society. Since almost 90 percent of the fastest-growing and highest-paying jobs require some postsecondary education, having a high school diploma and the…

  8. Understanding High School Graduation Rates in Connecticut

    Science.gov (United States)

    Alliance for Excellent Education, 2009

    2009-01-01

    Graduation rates are a fundamental indicator of whether or not the nation's public school system is doing what it is intended to do: enroll, engage, and educate youth to be productive members of society. Since almost 90 percent of the fastest-growing and highest-paying jobs require some postsecondary education, having a high school diploma and the…

  9. Understanding High School Graduation Rates in Hawaii

    Science.gov (United States)

    Alliance for Excellent Education, 2009

    2009-01-01

    Graduation rates are a fundamental indicator of whether or not the nation's public school system is doing what it is intended to do: enroll, engage, and educate youth to be productive members of society. Since almost 90 percent of the fastest-growing and highest-paying jobs require some postsecondary education, having a high school diploma and the…

  10. Understanding High School Graduation Rates in Vermont

    Science.gov (United States)

    Alliance for Excellent Education, 2009

    2009-01-01

    Graduation rates are a fundamental indicator of whether or not the nation's public school system is doing what it is intended to do: enroll, engage, and educate youth to be productive members of society. Since almost 90 percent of the fastest-growing and highest-paying jobs require some postsecondary education, having a high school diploma and the…

  11. Understanding High School Graduation Rates in Mississippi

    Science.gov (United States)

    Alliance for Excellent Education, 2009

    2009-01-01

    Graduation rates are a fundamental indicator of whether or not the nation's public school system is doing what it is intended to do: enroll, engage, and educate youth to be productive members of society. Since almost 90 percent of the fastest-growing and highest-paying jobs require some postsecondary education, having a high school diploma and the…

  12. Understanding High School Graduation Rates in California

    Science.gov (United States)

    Alliance for Excellent Education, 2009

    2009-01-01

    Graduation rates are a fundamental indicator of whether or not the nation's public school system is doing what it is intended to do: enroll, engage, and educate youth to be productive members of society. Since almost 90 percent of the fastest-growing and highest-paying jobs require some postsecondary education, having a high school diploma and the…

  13. Understanding High School Graduation Rates in Ohio

    Science.gov (United States)

    Alliance for Excellent Education, 2009

    2009-01-01

    Graduation rates are a fundamental indicator of whether or not the nation's public school system is doing what it is intended to do: enroll, engage, and educate youth to be productive members of society. Since almost 90 percent of the fastest-growing and highest-paying jobs require some postsecondary education, having a high school diploma and the…

  14. Understanding High School Graduation Rates in Montana

    Science.gov (United States)

    Alliance for Excellent Education, 2009

    2009-01-01

    Graduation rates are a fundamental indicator of whether or not the nation's public school system is doing what it is intended to do: enroll, engage, and educate youth to be productive members of society. Since almost 90 percent of the fastest-growing and highest-paying jobs require some postsecondary education, having a high school diploma and the…

  15. Understanding High School Graduation Rates in Maine

    Science.gov (United States)

    Alliance for Excellent Education, 2009

    2009-01-01

    Graduation rates are a fundamental indicator of whether or not the nation's public school system is doing what it is intended to do: enroll, engage, and educate youth to be productive members of society. Since almost 90 percent of the fastest-growing and highest-paying jobs require some postsecondary education, having a high school diploma and the…

  16. Understanding High School Graduation Rates in Washington

    Science.gov (United States)

    Alliance for Excellent Education, 2009

    2009-01-01

    Graduation rates are a fundamental indicator of whether or not the nation's public school system is doing what it is intended to do: enroll, engage, and educate youth to be productive members of society. Since almost 90 percent of the fastest-growing and highest-paying jobs require some postsecondary education, having a high school diploma and the…

  17. Understanding High School Graduation Rates in Louisiana

    Science.gov (United States)

    Alliance for Excellent Education, 2009

    2009-01-01

    Graduation rates are a fundamental indicator of whether or not the nation's public school system is doing what it is intended to do: enroll, engage, and educate youth to be productive members of society. Since almost 90 percent of the fastest-growing and highest-paying jobs require some postsecondary education, having a high school diploma and the…

  18. Understanding High School Graduation Rates in Colorado

    Science.gov (United States)

    Alliance for Excellent Education, 2009

    2009-01-01

    Graduation rates are a fundamental indicator of whether or not the nation's public school system is doing what it is intended to do: enroll, engage, and educate youth to be productive members of society. Since almost 90 percent of the fastest-growing and highest-paying jobs require some postsecondary education, having a high school diploma and the…

  19. Understanding High School Graduation Rates in Michigan

    Science.gov (United States)

    Alliance for Excellent Education, 2009

    2009-01-01

    Graduation rates are a fundamental indicator of whether or not the nation's public school system is doing what it is intended to do: enroll, engage, and educate youth to be productive members of society. Since almost 90 percent of the fastest-growing and highest-paying jobs require some postsecondary education, having a high school diploma and the…

  20. Understanding High School Graduation Rates in Indiana

    Science.gov (United States)

    Alliance for Excellent Education, 2009

    2009-01-01

    Graduation rates are a fundamental indicator of whether or not the nation's public school system is doing what it is intended to do: enroll, engage, and educate youth to be productive members of society. Since almost 90 percent of the fastest-growing and highest-paying jobs require some postsecondary education, having a high school diploma and the…

  1. Understanding High School Graduation Rates in Utah

    Science.gov (United States)

    Alliance for Excellent Education, 2009

    2009-01-01

    Graduation rates are a fundamental indicator of whether or not the nation's public school system is doing what it is intended to do: enroll, engage, and educate youth to be productive members of society. Since almost 90 percent of the fastest-growing and highest-paying jobs require some postsecondary education, having a high school diploma and the…

  2. Understanding High School Graduation Rates in Alabama

    Science.gov (United States)

    Alliance for Excellent Education, 2009

    2009-01-01

    Graduation rates are a fundamental indicator of whether or not the nation's public school system is doing what it is intended to do: enroll, engage, and educate youth to be productive members of society. Since almost 90 percent of the fastest-growing and highest-paying jobs require some postsecondary education, having a high school diploma and the…

  3. Understanding High School Graduation Rates in Arkansas

    Science.gov (United States)

    Alliance for Excellent Education, 2009

    2009-01-01

    Graduation rates are a fundamental indicator of whether or not the nation's public school system is doing what it is intended to do: enroll, engage, and educate youth to be productive members of society. Since almost 90 percent of the fastest-growing and highest-paying jobs require some postsecondary education, having a high school diploma and the…

  4. Understanding High School Graduation Rates in Missouri

    Science.gov (United States)

    Alliance for Excellent Education, 2009

    2009-01-01

    Graduation rates are a fundamental indicator of whether or not the nation's public school system is doing what it is intended to do: enroll, engage, and educate youth to be productive members of society. Since almost 90 percent of the fastest-growing and highest-paying jobs require some postsecondary education, having a high school diploma and the…

  5. Hydrogen absorption in solid aluminum during high-temperature steam oxidation

    Science.gov (United States)

    Andreev, L. A.; Gelman, B. G.; Zhukhovitskiy, A. A.

    1979-01-01

    Hydrogen is emitted by aluminum heated in a vacuum after high-temperature steam treatment. Wire samples are tested for this effect, showing dependence on surface area. Two different mechanisms of absorption are inferred, and reactions deduced.

  6. EMPIRICAL LINE LISTS AND ABSORPTION CROSS SECTIONS FOR METHANE AT HIGH TEMPERATURES

    Energy Technology Data Exchange (ETDEWEB)

    Hargreaves, R. J.; Bernath, P. F.; Dulick, M. [Department of Chemistry and Biochemistry, Old Dominion University, 4541 Hampton Boulevard, Norfolk, VA 23529 (United States); Bailey, J., E-mail: rhargrea@odu.edu [School of Physics, University of New South Wales, Sydney, NSW 2052 (Australia)

    2015-11-01

    Hot methane is found in many “cool” sub-stellar astronomical sources including brown dwarfs and exoplanets, as well as in combustion environments on Earth. We report on the first high-resolution laboratory absorption spectra of hot methane at temperatures up to 1200 K. Our observations are compared to the latest theoretical spectral predictions and recent brown dwarf spectra. The expectation that millions of weak absorption lines combine to form a continuum, not seen at room temperature, is confirmed. Our high-resolution transmittance spectra account for both the emission and absorption of methane at elevated temperatures. From these spectra, we obtain an empirical line list and continuum that is able to account for the absorption of methane in high temperature environments at both high and low resolution. Great advances have recently been made in the theoretical prediction of hot methane, and our experimental measurements highlight the progress made and the problems that still remain.

  7. Empirical line lists and absorption cross sections for methane at high temperature

    CERN Document Server

    Hargreaves, Robert J; Bailey, Jeremy; Dulick, Michael

    2015-01-01

    Hot methane is found in many "cool" sub-stellar astronomical sources including brown dwarfs and exoplanets, as well as in combustion environments on Earth. We report on the first high-resolution laboratory absorption spectra of hot methane at temperatures up to 1200 K. Our observations are compared to the latest theoretical spectral predictions and recent brown dwarf spectra. The expectation that millions of weak absorption lines combine to form a continuum, not seen at room temperature, is confirmed. Our high-resolution transmittance spectra account for both the emission and absorption of methane at elevated temperatures. From these spectra, we obtain an empirical line list and continuum that is able to account for the absorption of methane in high temperature environments at both high and low resolution. Great advances have recently been made in the theoretical prediction of hot methane, and our experimental measurements highlight the progress made and the problems that still remain.

  8. Optical absorption in highly strained Ge/SiGe quantum wells: The role of Γ→ Δ scattering

    Science.gov (United States)

    Lever, L.; Ikonić, Z.; Valavanis, A.; Kelsall, R. W.; Myronov, M.; Leadley, D. R.; Hu, Y.; Owens, N.; Gardes, F. Y.; Reed, G. T.

    2012-12-01

    We report the observation of the quantum-confined Stark effect in Ge/SiGe multiple quantum well heterostructures grown on Si0.22Ge0.78 virtual substrates. The large compressive strain in the Ge quantum well layers caused by the lattice mismatch with the virtual substrate results in a blue shift of the direct absorption edge, as well as a reduction in the Γ-valley scattering lifetime because of strain-induced splittings of the conduction band valleys. We investigate theoretically the Γ-valley carrier lifetimes by evaluating the Γ →L and Γ →Δ scattering rates in strained Ge/SiGe semiconductor heterostructures. These scattering rates are used to determine the lifetime broadening of excitonic peaks and the indirect absorption in simulated absorption spectra, which are compared with measured absorption spectra for quantum well structures with systematically varied dimensions. We find that Γ →Δ scattering is significant in compressively strained Ge quantum wells and that the Γ-valley electron lifetime is less than 50 fs in the highly strained structures reported here, where Γ →Δ scattering accounted for approximately half of the total scattering rate.

  9. A miniature high repetition rate shock tube.

    Science.gov (United States)

    Tranter, R S; Lynch, P T

    2013-09-01

    A miniature high repetition rate shock tube with excellent reproducibility has been constructed to facilitate high temperature, high pressure, gas phase experiments at facilities such as synchrotron light sources where space is limited and many experiments need to be averaged to obtain adequate signal levels. The shock tube is designed to generate reaction conditions of T > 600 K, P shock waves with predictable characteristics are created, repeatably. Two synchrotron-based experiments using this apparatus are also briefly described here, demonstrating the potential of the shock tube for research at synchrotron light sources.

  10. Ultra-sensitive Absorption Diagnostics of Thin Films for High-power Laser Interference Coatings

    Science.gov (United States)

    2015-01-05

    Absorption Diagnostics of Thin Films for High-power Laser Interference Coatings REPORT DOCUMENTATION PAGE Form Approved OMB No. 0704-0188 Public...Absorption Diagnostics of Thin Films for High-power Laser Interference Coatings FA9550-13-1-0201 Jorge J. Rocca (PI) Oscar E. Martinez Carmen S...work consists of the development of a prototype suitable for incorporation into the deposition chamber. Such powerful diagnostics does not

  11. High strain rate behaviour of polypropylene microfoams

    Science.gov (United States)

    Gómez-del Río, T.; Garrido, M. A.; Rodríguez, J.; Arencón, D.; Martínez, A. B.

    2012-08-01

    Microcellular materials such as polypropylene foams are often used in protective applications and passive safety for packaging (electronic components, aeronautical structures, food, etc.) or personal safety (helmets, knee-pads, etc.). In such applications the foams which are used are often designed to absorb the maximum energy and are generally subjected to severe loadings involving high strain rates. The manufacture process to obtain polymeric microcellular foams is based on the polymer saturation with a supercritical gas, at high temperature and pressure. This method presents several advantages over the conventional injection moulding techniques which make it industrially feasible. However, the effect of processing conditions such as blowing agent, concentration and microfoaming time and/or temperature on the microstructure of the resulting microcellular polymer (density, cell size and geometry) is not yet set up. The compressive mechanical behaviour of several microcellular polypropylene foams has been investigated over a wide range of strain rates (0.001 to 3000 s-1) in order to show the effects of the processing parameters and strain rate on the mechanical properties. High strain rate tests were performed using a Split Hopkinson Pressure Bar apparatus (SHPB). Polypropylene and polyethylene-ethylene block copolymer foams of various densities were considered.

  12. High strain rate behaviour of polypropylene microfoams

    Directory of Open Access Journals (Sweden)

    Martínez A.B.

    2012-08-01

    Full Text Available Microcellular materials such as polypropylene foams are often used in protective applications and passive safety for packaging (electronic components, aeronautical structures, food, etc. or personal safety (helmets, knee-pads, etc.. In such applications the foams which are used are often designed to absorb the maximum energy and are generally subjected to severe loadings involving high strain rates. The manufacture process to obtain polymeric microcellular foams is based on the polymer saturation with a supercritical gas, at high temperature and pressure. This method presents several advantages over the conventional injection moulding techniques which make it industrially feasible. However, the effect of processing conditions such as blowing agent, concentration and microfoaming time and/or temperature on the microstructure of the resulting microcellular polymer (density, cell size and geometry is not yet set up. The compressive mechanical behaviour of several microcellular polypropylene foams has been investigated over a wide range of strain rates (0.001 to 3000 s−1 in order to show the effects of the processing parameters and strain rate on the mechanical properties. High strain rate tests were performed using a Split Hopkinson Pressure Bar apparatus (SHPB. Polypropylene and polyethylene-ethylene block copolymer foams of various densities were considered.

  13. Effect of dietary sphingomyelin on absorption and fractional synthetic rate of cholesterol and serum lipid profile in humans

    Science.gov (United States)

    2013-01-01

    Background Diets enriched with sphingolipids may improve blood lipid profiles. Studies in animals have shown reductions in cholesterol absorption and alterations in blood lipids after treatment with sphingomyelin (SM). However, minimal information exists on effect of SM on cholesterol absorption and metabolism in humans. The objective was to assess the effect of SM consumption on serum lipid concentrations and cholesterol metabolism in healthy humans. Methods Ten healthy adult males and females completed a randomized crossover study. Subjects consumed controlled diets with or without 1 g/day SM for 14 days separated by at least 4 week washout period. Serum lipid profile and markers of cholesterol metabolism including cholesterol absorption and synthesis were analyzed. Results Serum triglycerides, total, LDL- and VLDL- cholesterol were not affected while HDL cholesterol concentrations were increased (p = 0.043) by SM diet consumption. No change in cholesterol absorption and cholesterol fractional synthesis rate was observed with supplementation of SM compared to control. Intraluminal cholesterol solubilization was also not affected by consumption of SM enriched diet. Conclusions In humans, 1 g/day of dietary SM does not alter the blood lipid profile except for an increased HDL-cholesterol concentration and has no effect on cholesterol absorption, synthesis and intraluminal solubilization compared to control. Trial registration Clinicaltrials.gov # NCT00328211 PMID:23958473

  14. Research on the sound absorption characteristics of porous metal materials at high sound pressure levels

    Directory of Open Access Journals (Sweden)

    Xiaopeng Wang

    2015-05-01

    Full Text Available Porous metal materials are widely used in noise control with high sound pressure applications such as aircraft engine liners and combustion chambers for rocket engines due to their excellent performance of sound absorption characteristics and distinguished advantages in heat resistance, lightness, and stiffness. Understanding the effect of sound pressure on the acoustic properties of these materials is crucial when attempting to predict silencer performance. In this article, we experimentally investigate the sound absorption characteristics of porous metal materials at high sound pressure level. The effects of material parameters on the sound absorption characteristics of porous metal materials under high sound pressure level are further explored experimentally. Measurements are carried out by using a standard impedance tube that has been modified to accommodate sound pressure level of up to 150 dB. The experimental results show that with the increase in sound pressure level, the effect of sound pressure level on the sound absorption characteristics yields different variation regularities in different frequencies. The sound absorption performance of porous metal materials increases with the increase in sound pressure level in low frequency, which is reasonably consistent with the theoretical results. Under high sound pressure level, the sound absorption characteristics are significantly dependent upon the material parameters such as the metal fiber diameter, the material porosity, and the material thickness. It could provide a reliable experimental validation for the applications of porous metal materials in the area of vibration and noise control at high sound pressure levels.

  15. High strain rate characterization of polymers

    Science.gov (United States)

    Siviour, Clive R.

    2017-01-01

    This paper reviews the literature on the response of polymers to high strain rate deformation. The main focus is on the experimental techniques used to characterize this response. The paper includes a small number of examples as well as references to experimental data over a wide range of rates, which illustrate the key features of rate dependence in these materials; however this is by no means an exhaustive list. The aim of the paper is to give the reader unfamiliar with the subject an overview of the techniques available with sufficient references from which further information can be obtained. In addition to the `well established' techniques of the Hopkinson bar, Taylor Impact and Transverse impact, a discussion of the use of time-temperature superposition in interpreting and experimentally replicating high rate response is given, as is a description of new techniques in which mechanical parameters are derived by directly measuring wave propagation in specimens; these are particularly appropriate for polymers with low wave speeds. The vast topic of constitutive modelling is deliberately excluded from this review.

  16. High-resolution absorption measurements of NH3 at high temperatures: 2100-5500 cm-1

    Science.gov (United States)

    Barton, Emma J.; Yurchenko, Sergei N.; Tennyson, Jonathan; Clausen, Sønnik; Fateev, Alexander

    2017-03-01

    High-resolution absorption spectra of NH3 in the region 2100-5500 cm-1 at 1027 °C and approximately atmospheric pressure (1045±3 mbar) are measured. An NH3 concentration of 10% in volume fraction is used in the measurements. Spectra are recorded in a high-temperature gas-flow cell using a Fourier Transform Infrared (FTIR) spectrometer at a nominal resolution of 0.09 cm-1. The spectra are analysed by comparison to a variational line list, BYTe, and experimental energy levels determined using the MARVEL procedure. 2308 lines have been assigned to 45 different bands, of which 1755 and 15 have been assigned or observed for the first time in this work.

  17. A prototype of a high rating MRPC

    Institute of Scientific and Technical Information of China (English)

    WANG Yi; WANG Jing-Bo; YAN Qiang; LI Yuan-Jing; CHENG Jian-Ping; YUE Qian; LI Jin

    2009-01-01

    Six-gap resistive plate chamber (MRPC) prototypes with semiconductive glass electrodes (bulk resistivity~1010.cm) were studied for suitability in time-of-flight (TOF) applications at high rates. These studies were performed using a continuous electron beam of 800 MeV at IHEP and an X-ray machine. Time resolutions of about 100 ps and efficiencies larger than 90% were obtained for flux densities up to 28 kHz/cm2.

  18. Reserve, flowing electrolyte, high rate lithium battery

    Science.gov (United States)

    Puskar, M.; Harris, P.

    Flowing electrolyte Li/SOCl2 tests in single cell and multicell bipolar fixtures have been conducted, and measurements are presented for electrolyte flow rates, inlet and outlet temperatures, fixture temperatures at several points, and the pressure drop across the fixture. Reserve lithium batteries with flowing thionyl-chloride electrolytes are found to be capable of very high energy densities with usable voltages and capacities at current densities as high as 500 mA/sq cm. At this current density, a battery stack 10 inches in diameter is shown to produce over 60 kW of power while maintaining a safe operating temperature.

  19. Survey on Different Samsung with Nokia Smart Mobile Phones in the Specific Absorption Rate Electrical Field of Head.

    Science.gov (United States)

    Fakhri, Yadolah; Alinejad, Azim; Keramati, Hassan; Bay, Abotaleb; Avazpour, Moayed; Zandsalimi, Yahya; Moradi, Bigard; Rasouli Amirhajeloo, Leila; Mirzaei, Maryam

    2016-09-01

    The use of smart phones is increasing in the world. This excessive use, especially in the last two decades, has created too much concern on the effects of emitted electromagnetic fields and specific absorption rate on human health. In this descriptive-analytical study of the electric field resulting from smart phones of Samsung and Nokia by portable measuring device, electromagnetic field, Model HI-3603-VDT/VLF, were measured. Then, head absorption rate was calculated in these two mobiles by ICNIRP equation. Finally, the comparison of specific absorption rate, especially between Samsung and Nokia smart phones, was conducted by T-Test statistics analysis. The mean of electric field for Samsung and Nokia smart mobile phones was obtained 1.8 ±0.19 v/m  and 2.23±0.39 v/m , respectively, while the range of the electric field was obtained as 1.56-2.21 v/m and 1.69-2.89 v/m for them, respectively. The mean of specific absorption rate in Samsung and Nokia was obtained 0.002 ± 0.0005 W/Kg and 0.0041±0.0013 W/Kg at the frequency of 900 MHz and 0.004±0.001 W/Kg and 0.0062±0.0002 W/Kg at the frequency of 1800 MHz respectively. The ratio of mean electronic field to guidance in the Samsung mobile phone at the frequency of 900 MHz and 1800 MHz was 4.36% and 3.34%, while was 5.62% and 4.31% in the Nokia mobile phone, respectively. The ratio of mean head specific absorption rate in smart mobile phones of Samsung and Nokia in the guidance level at the frequency of 900 was 0.15% and 0.25%, respectively, while was 0.23 %and 0.38% at the frequency of 1800 MHz, respectively. The rate of specific absorption of Nokia smart  mobile phones at the frequencies of 900 and 1800 MHz  was significantly higher than Samsung (p value Nokia smart phones is higher than Samsung smart mobile phone.

  20. Survey on Different Samsung with Nokia Smart Mobile Phones in the Specific Absorption Rate Electrical Field of Head

    Science.gov (United States)

    Fakhri, Yadolah; Alinejad, Azim; Keramati, Hassan; Bay, Abotaleb; Avazpour, Moayed; Zandsalimi, Yahya; Moradi, Bigard; Amirhajeloo, Leila Rasouli; Mirzaei, Maryam

    2016-01-01

    The use of smart phones is increasing in the world. This excessive use, especially in the last two decades, has created too much concern on the effects of emitted electromagnetic fields and specific absorption rate on human health. In this descriptive-analytical study of the electric field resulting from smart phones of Samsung and Nokia by portable measuring device, electromagnetic field, Model HI-3603-VDT/VLF, were measured. Then, head absorption rate was calculated in these two mobiles by ICNIRP equation. Finally, the comparison of specific absorption rate, especially between Samsung and Nokia smart phones, was conducted by T-Test statistics analysis. The mean of electric field for Samsung and Nokia smart mobile phones was obtained 1.8 ±0.19 v/m and 2.23±0.39 v/m, respectively, while the range of the electric field was obtained as 1.56-2.21 v/m and 1.69-2.89 v/m for them, respectively. The mean of specific absorption rate in Samsung and Nokia was obtained 0.002 ± 0.0005 W/Kg and 0.0041±0.0013 W/Kg at the frequency of 900 MHz and 0.004±0.001 W/Kg and 0.0062±0.0002 W/Kg at the frequency of 1800 MHz respectively. The ratio of mean electronic field to guidance in the Samsung mobile phone at the frequency of 900 MHz and 1800 MHz was 4.36% and 3.34%, while was 5.62% and 4.31% in the Nokia mobile phone, respectively. The ratio of mean head specific absorption rate in smart mobile phones of Samsung and Nokia in the guidance level at the frequency of 900 was 0.15% and 0.25%, respectively, while was 0.23% and 0.38% at the frequency of 1800 MHz, respectively. The rate of specific absorption of Nokia smart mobile phones at the frequencies of 900 and 1800 MHz was significantly higher than Samsung (p value Samsung smart mobile phone. PMID:27157169

  1. Ultraviolet-visible absorption in highly transparent solids by laser calorimetry and wavelength modulation spectroscopy.

    Science.gov (United States)

    Harrington, J A; Bobbs, B L; Braunstein, M; Kim, R K; Stearns, R; Braunstein, R

    1978-05-15

    The requirements for low-loss optical materials for use on excimer lasers have stimulated the investigation of optical absorption in a variety of highly transparent materials at visible and uv wavelengths. To provide information over a wide spectral range at low absorption levels ( approximately 10(-5) cm(-1)), laser calorimetric and wavelength modulation spectroscopic techniques were used. Blending these two methods provided, for the first time, spectral information well below the usual levels of absorption measured in studies of the Urbach tail.

  2. Hybrid nanocone forests with high absorption in full-solar spectrum for solar cell applications

    Science.gov (United States)

    Yang, Yudong; Mao, Haiyang; Xiong, Jijun; Ming, Anjie; Wang, Weibing

    2016-11-01

    In this work, hybrid nanocone forests (HNFs) with high absorption in full-solar-spectrum are fabricated based on a plasma repolymerization technique. The HNFs combine light trapping effect of the nanocone forests with surface plasmon resonance effect of the metallic nanoparticles, thus can achieve an optimized absorption larger than 80% in the full-solar spectrum (i.e. 200-2500nm). Besides, with the hybrid nanostructures, the absorption decrease around the Si bandgap width can be narrowed greatly, while the normalized utilization efficiency of solar radiation can be increased. Therefore, usage of the HNFs as a texture structure in solar cells to obtain higher conversion efficiencies is foreseeable.

  3. HIghZ: A search for HI absorption in high-redshift radio galaxies

    Science.gov (United States)

    Allison, J.; Callingham, J.; Sadler, E.; Wayth, R.; Curran, S.; Mahoney, E.

    2017-01-01

    We will use the unique low-frequency spectral capability of the MWA to carry out a pilot survey for neutral gas in the interstellar medium of the most distant (z>5) radio galaxies in the Universe. Through detection of the HI 21-cm line in absorption we aim to place stringent lower limits on the source redshift, confirming its location in the early Universe. Our sample makes use of the excellent wide-band spectral information available from the recently completed MWA GLEAM survey, from which we have selected a sample of ultra-steep peaked-spectrum radio sources that have a spectral turnover below 300 MHz. These sources should be ideal candidates for high-redshift compact radio galaxies since they have (a) spectral peaks that turnover below 1GHz and (b) very steep (alpha environments expected for radio galaxies in the early Universe. Using the MWA, we aim to verify this hypothesis through the detection of significant column densities of cold HI. This pathfinder project will provide important technical information that will inform future absorption surveys both with the MWA and, ultimately, the SKA-LOW telescope.

  4. Absorption and desorption mass transfer rates in non-reactive systems

    NARCIS (Netherlands)

    Hamborg, Espen S.; Kersten, Sascha R. A.; Versteeg, Geert F.

    2010-01-01

    Liquid phase mass transfer coefficients have been measured in a controlled environment during gas absorption into a liquid and gas desorption from a liquid in a batch operated stirred tank reactor over a wide range of operating conditions. At identical operating conditions, the mass transfer

  5. Absorption and desorption mass transfer rates in chemically enhanced reactive systems. Part I : Chemical enhancement factors

    NARCIS (Netherlands)

    Hamborg, Espen S.; Versteeg, Geert F.

    2012-01-01

    The chemical enhancement factors have been measured in a controlled environment for absorption and desorption mass transfer processes in aqueous 2.0 M MDEA solutions at temperatures of 298.15, 313.15, and 333.15 K and the loading of CO2 ranging from 0 to 0.8 in a batch-operated stirred tank reactor.

  6. High Temperature Sound Absorption Coating - Soundown HT Project

    Data.gov (United States)

    National Aeronautics and Space Administration — MPAC and UMR are proposing development of an Acoustic Control System for high temperature gas flow in ducts. This control system is based on a passive inorganic...

  7. High-efficiency gas heat pump air-conditioner equipped with absorption refrigerator

    Science.gov (United States)

    Imai, Yosuke; Ohashi, Toshinori; Okamoto, Hiroaki; Hihara, Eiji; Kawakami, Ryuichiro

    On conventional gas heat pump(GHP), waste heat from gas engine that uses as driving source is emitted into outside. So from the standpoint of efficient use of waste heat, it is assumed that waste heat from gas engine is used as driving source of absorption chiller, and high temperature condensate refrigerant in GHP is subcooled to middle temperature by cold source from absorption cycle, and as a result, GHP makes more efficiency. However, in equipping GHP with absorption cycle, downsizing and high-efficiency of absorption cycle is required. In this study, air-cooled subcooled adiabatic absorber is focused and physical phenomenon in it is analyzed, and finally one perception of the optimized designing is shown.

  8. High-speed traveling-wave electro-absorption modulators

    Science.gov (United States)

    Westergren, Urban; Yu, Yichuan; Thylén, Lars

    2006-07-01

    Electroabsorption modulators (EAM) based on quantum-confined Stark effect (QCSE) in multiplequantum wells (MQW) have been demonstrated to provide high-speed, low drive voltage, and high extinction ratio. They are compact in size and can be monolithically integrated with continuous-wave (CW) lasers. In order to achieve both high speed and low drive-voltage operation, travelling-wave (TW) electrode structures can be used for EAMs. The inherently low impedance of high-speed EAMs may be transformed to values close to the standard 50Ohm impedance using periodic microwave structures with a combination of passive transmission lines with high characteristic impedance and active modulator sections with low impedance. Modulation bandwidths of 100GHz (-3dBe) have been accomplished with electrical reflections lower than -10dB in a 50Ohm system. Transmission at 80Gbit/s with non-return-to-zero (NRZ) code has been demonstrated for InP-based TWEAMs using electronic time-domain multiplexing (ETDM), indicating the possibility of reaching speeds of 100Gbit/s and beyond.

  9. SYNTHESIS AND PROPERTIES OF HIGHLY OIL-ABSORPTIVE RESIN WITH HYDROXY ETHYLACRYLATE AS POTENTIAL CROSSLINKING AGENT

    Institute of Scientific and Technical Information of China (English)

    FENG Yan; XIAO Changfa

    2006-01-01

    A concept of potential crosslinking agent was introduced into the synthesizing process of highly oil-absorptive resin that is traditionally prepared by single chemical crosslinking. The resin was heated after manufactured to obtain three-dimension network structure. The effects of potential crosslinking agent and the crosslinking conditions on the absorptive properties of resin were studied.The results showed that hydroxyl ethylacrylate got satisfied results, and the resin with it had good oil absorbency and oil retention.

  10. High-resolution absorption cross sections of C$_{2}$H$_{6}$ at elevated temperatures

    OpenAIRE

    2015-01-01

    Infrared absorption cross sections near 3.3 $\\mu$m have been obtained for ethane, C$_{2}$H$_{6}$. These were acquired at elevated temperatures (up to 773 K) using a Fourier transform infrared spectrometer and tube furnace with a resolution of 0.005 cm$^{-1}$. The integrated absorption was calibrated using composite infrared spectra taken from the Pacific Northwest National Laboratory (PNNL). These new measurements are the first high-resolution infrared C$_{2}$H$_{6}$ cross sections at elevate...

  11. Determining neutrino absorption spectra at ultra-high energies

    NARCIS (Netherlands)

    Scholten, O.; van Vliet, A. R.

    2008-01-01

    A very efficient method for measuring the flux of ultra-high energy ( UHE) neutrinos is through the detection of radio waves which are emitted by the particle shower in the lunar regolith. The highest acceptance is reached for radio waves in the frequency band of 100 - 200 MHz which can be measured

  12. High strain rate deformation of layered nanocomposites

    Science.gov (United States)

    Lee, Jae-Hwang; Veysset, David; Singer, Jonathan P.; Retsch, Markus; Saini, Gagan; Pezeril, Thomas; Nelson, Keith A.; Thomas, Edwin L.

    2012-11-01

    Insight into the mechanical behaviour of nanomaterials under the extreme condition of very high deformation rates and to very large strains is needed to provide improved understanding for the development of new protective materials. Applications include protection against bullets for body armour, micrometeorites for satellites, and high-speed particle impact for jet engine turbine blades. Here we use a microscopic ballistic test to report the responses of periodic glassy-rubbery layered block-copolymer nanostructures to impact from hypervelocity micron-sized silica spheres. Entire deformation fields are experimentally visualized at an exceptionally high resolution (below 10 nm) and we discover how the microstructure dissipates the impact energy via layer kinking, layer compression, extreme chain conformational flattening, domain fragmentation and segmental mixing to form a liquid phase. Orientation-dependent experiments show that the dissipation can be enhanced by 30% by proper orientation of the layers.

  13. Calculations of Solar Shortwave Heating Rates due to Black Carbon and Ozone Absorption Using in Situ Measurements

    Science.gov (United States)

    Gao, R. S.; Hall, S. R.; Swartz, W. H.; Spackman, J. R.; Watts, L. A.; Fahey, D. W.; Aikin, K. C.; Shetter, R. E.; Bui, T. P.

    2008-01-01

    Results for the solar heating rates in ambient air due to absorption by black-carbon (BC) containing particles and ozone are presented as calculated from airborne observations made in the tropical tropopause layer (TTL) in January-February 2006. The method uses airborne in situ observations of BC particles, ozone and actinic flux. Total BC mass is obtained along the flight track by summing the masses of individually detected BC particles in the range 90 to 600-nm volume-equivalent diameter, which includes most of the BC mass. Ozone mixing ratios and upwelling and partial downwelling solar actinic fluxes were measured concurrently with BC mass. Two estimates used for the BC wavelength-dependent absorption cross section yielded similar heating rates. For mean altitudes of 16.5, 17.5, and 18.5 km (0.5 km) in the tropics, average BC heating rates were near 0.0002 K/d. Observed BC coatings on individual particles approximately double derived BC heating rates. Ozone heating rates exceeded BC heating rates by approximately a factor of 100 on average and at least a factor of 4, suggesting that BC heating rates in this region are negligible in comparison.

  14. Changes in 14CO2 absorption rates by the successive leaves in buckwheat and white mustard plants of various ages

    Directory of Open Access Journals (Sweden)

    B. Gej

    2015-01-01

    Full Text Available The experiments with different-aged buckwheat (Fagopyrum esculentum Mnch. and white mustard (Sinapis alba L. plants showed that the sub-apical and middle leaves, before they had reached their approximate final sizes, had the highest rates of 14CO2 absorption. The intensity of this process decreases in each leaf with age of the plant. White mustard leaves showed a little higher absorption rate of 14CO2 than analogous leaves of buckwheat plants. In the investigated leaves no close relationship between the intensity of 14CO2 assimilation and chlorophyll a and b concentration was observed. Some possible reasons for the higher intensity of photosynthesis in the sub-apical leaves are discussed.

  15. High frame-rate digital radiographic videography

    Energy Technology Data Exchange (ETDEWEB)

    King, N.S.P.; Cverna, F.H.; Albright, K.L.; Jaramillo, S.A.; Yates, G.J.; McDonald, T.E. [Los Alamos National Lab., NM (United States); Flynn, M.J.; Tashman, S. [Henry Ford Health System, Detroit, MI (United States)

    1994-09-01

    High speed x-ray imaging can be an important tool for observing internal processes in a wide range of applications. In this paper we describe preliminary implementation of a system having the eventual goal of observing the internal dynamics of bone and joint reactions during loading. Two Los Alamos National Laboratory (LANL) gated and image intensified camera systems were used to record images from an x-ray image convertor tube to demonstrate the potential of high frame-rate digital radiographic videography in the analysis of bone and joint dynamics of the human body. Preliminary experiments were done at LANL to test the systems. Initial high frame-rate imaging (from 500 to 1000 frames/s) of a swinging pendulum mounted to the face of an X-ray image convertor tube demonstrated high contrast response and baseline sensitivity. The systems were then evaluated at the Motion Analysis Laboratory of Henry Ford Health Systems Bone and Joint Center. Imaging of a 9 inch acrylic disk with embedded lead markers rotating at approximately 1000 RPM, demonstrated the system response to a high velocity/high contrast target. By gating the P-20 phosphor image from the X-ray image convertor with a second image intensifier (II) and using a 100-microsecond wide optical gate through the second II, enough prompt light decay from the x-ray image convertor phosphor had taken place to achieve reduction of most of the motion blurring. Measurement of the marker velocity was made by using video frames acquired at 500 frames/s. The data obtained from both experiments successfully demonstrated the feasibility of the technique. Several key areas for improvement are discussed along with salient test results and experiment details.

  16. Novel High Rate Lithium Intercalation Cathode Materials

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Application of amorphous V2O5/carbon/neodymium oxide (Nd2O3) composite is one of ways to surmount the lower electrical conductivity of V2O5. A new type of V2O5/carbon/Nd2O3 composite was prepared by mixing vanadium oxide hydrosol, acetone, carbon and Nd2O3 powder. High rate discharge/charge property of the composite electrode was tested electrochemically. This composite with Nd2O3 added shows the improvement of not only the discharge capacity but also cycle durability discharge capacity. The rate capability of the composite cathode also increases with the addition of Nd2O3.and cycle life are probably caused by the increase in porosity of open pores and short diffusion length of the active material on the lithium-ion insertion.

  17. High Rate Laser Pitting Technique for Solar Cell Texturing

    Energy Technology Data Exchange (ETDEWEB)

    Hans J. Herfurth; Henrikki Pantsar

    2013-01-10

    High rate laser pitting technique for solar cell texturing Efficiency of crystalline silicon solar cells can be improved by creating a texture on the surface to increase optical absorption. Different techniques have been developed for texturing, with the current state-of-the-art (SOA) being wet chemical etching. The process has poor optical performance, produces surfaces that are difficult to passivate or contact and is relatively expensive due to the use of hazardous chemicals. This project shall develop an alternative process for texturing mc-Si using laser micromachining. It will have the following features compared to the current SOA texturing process: -Superior optical surfaces for reduced front-surface reflection and enhanced optical absorption in thin mc-Si substrates -Improved surface passivation -More easily integrated into advanced back-contact cell concepts -Reduced use of hazardous chemicals and waste treatment -Similar or lower cost The process is based on laser pitting. The objective is to develop and demonstrate a high rate laser pitting process which will exceed the rate of former laser texturing processes by a factor of ten. The laser and scanning technologies will be demonstrated on a laboratory scale, but will use inherently technologies that can easily be scaled to production rates. The drastic increase in process velocity is required for the process to be implemented as an in-line process in PV manufacturing. The project includes laser process development, development of advanced optical systems for beam manipulation and cell reflectivity and efficiency testing. An improvement of over 0.5% absolute in efficiency is anticipated after laser-based texturing. The surface textures will be characterized optically, and solar cells will be fabricated with the new laser texturing to ensure that the new process is compatible with high-efficiency cell processing. The result will be demonstration of a prototype process that is suitable for scale-up to a

  18. Absorption and Turnover Rates of Iron Measured by the Whole Body Counter

    Energy Technology Data Exchange (ETDEWEB)

    Price, D. C.; Cohn, S. H.

    1962-09-05

    Human iron metabolism has been extensively studied in the past twenty-five years with the radioisotopes iron55 and iron59. Before the availability of the whole body counter, however, iron absorption studies were performed by the indirect methods of fecal assay of unabsorbed radioiron, and estimation of red cell incorporation of absorbed tracer. The few long-term excretion studies performed required numerous assumptions, since human iron excretion was less well understood. Whole body counting provides a simple and accurate method of measuring the total body retention of administrative tracer iron59, thus making absorption and subsequent excretion determinations possible with a single radioiron study. The energetic gamma emissions of iron59 permit ready external detection with small quantities of isotope, Normal radioiron distribution is uniform throughout the circulating red cell mass and thus minimize geometry influences on the counting efficiency, 0nly the 45.1 day half-life of iron59 limits long term iron turnover studies. Measurements of iron59 absorption and long-term body turnover have been under way at Brookhaven National Laboratory for over two years. The present paper outlines some of the results of these studies, and discusses some implications of the method. (auth)

  19. Inhaled histamine increases the rate of absorption of sodium cromoglycate from the lung.

    Science.gov (United States)

    Richards, R; Fowler, C; Simpson, S; Renwick, A G; Holgate, S T

    1992-01-01

    Since many factors may alter lung epithelial permeability (LEP) to water soluble molecules, the effect of histamine on the absorption and clearance of inhaled sodium cromoglycate was examined in seven mildly asthmatic patients with hyperresponsive airways and eight normal subjects. The subjects underwent histamine challenge to determine the provocative concentration of histamine required to reduce the forced expiratory volume in one second (FEV1) by 20% (PC20) from baseline. On two further visits they inhaled either saline placebo or histamine and 5 min later inhaled an aerosol containing sodium cromoglycate. Measurements of FEV1 were made and blood samples taken for analysis of plasma sodium cromoglycate concentration at intervals for 3 h. In the asthmatic group histamine inhalation led to a 24 +/- 4% reduction in FEV1 but had no effect on the normal subjects. When compared with inhaled saline, histamine increased the initial pulmonary absorption of SCG without influencing the total amount of drug absorbed in both asthmatics and normals. These observations suggest that the pharmacokinetics of inhaled sodium cromoglycate may be altered significantly by inflammatory mediators present at the site of drug absorption from the airways. PMID:1576060

  20. Experimental recombination rates for highly charged ions

    Energy Technology Data Exchange (ETDEWEB)

    Reinhold Schuch [Dept. of Atomic Physics, Stockholm Univ., Frescativ., Stockholm (Sweden)

    2000-01-01

    Recent studies of recombination between free electrons and highly charged ions using electron coolers of heavy-ion storage rings have produced accurate rate coefficients of interest for plasma modeling and diagnostics. Some surprises were discovered which can lead to revisions of recombination models. With bare ions one finds at low energy a strong and puzzling deviation from radiative recombination theory. Dielectronic recombination with C3+, N4+ show that jj coupling gives essential contributions to the cross section also for light ions. (author)

  1. Highly selective population of two excited states in nonresonant two-photon absorption

    Institute of Scientific and Technical Information of China (English)

    Zhang Hui; Zhang Shi-An; Sun Zhen-Rong

    2011-01-01

    A nonresonant two-photon absorption process can be manipulated by tailoring the ultra-short laser pulse.In this paper,we theoretically demonstrate a highly selective population of two excited states in the nonresonant two-photon absorption process by rationally designing a spectral phase distribution.Our results show that one excited state is maximally populated while the other state population is widely tunable from zero to the maximum value.We believe that the theoretical results may play an important role in the selective population of a more complex nonlinear process comprising nonresonant two-photon absorption,such as resonance-mediated(2+1)-three-photon absorption and (2+1)-resonant multiphoton ionization.

  2. High energy X-ray phase and dark-field imaging using a random absorption mask

    Science.gov (United States)

    Wang, Hongchang; Kashyap, Yogesh; Cai, Biao; Sawhney, Kawal

    2016-07-01

    High energy X-ray imaging has unique advantage over conventional X-ray imaging, since it enables higher penetration into materials with significantly reduced radiation damage. However, the absorption contrast in high energy region is considerably low due to the reduced X-ray absorption cross section for most materials. Even though the X-ray phase and dark-field imaging techniques can provide substantially increased contrast and complementary information, fabricating dedicated optics for high energies still remain a challenge. To address this issue, we present an alternative X-ray imaging approach to produce transmission, phase and scattering signals at high X-ray energies by using a random absorption mask. Importantly, in addition to the synchrotron radiation source, this approach has been demonstrated for practical imaging application with a laboratory-based microfocus X-ray source. This new imaging method could be potentially useful for studying thick samples or heavy materials for advanced research in materials science.

  3. Recrystallization of High Carbon Steel during High Strain Rate

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The recrystallization of high carbon steel during high temperature and high speed rolling has been studied by analyzing the stress-strain curves and the austenite grain size.Isothermal multi-pass hot compression at high strain rate was carried out by Gleeble-2000. The austenite grain size was measured by IBAS image analysis system. The results show that static recrystallization occurred at interpass time under pre-finish rolling, and at the finish rolling stage, due to the brief interpass time, static recrystallization can not be found.

  4. High counting rate resistive-plate chamber

    Science.gov (United States)

    Peskov, V.; Anderson, D. F.; Kwan, S.

    1993-05-01

    Parallel-plate avalanche chambers (PPAC) are widely used in physics experiments because they are fast (less than 1 ns) and have very simple construction: just two parallel metallic plates or mesh electrodes. Depending on the applied voltage they may work either in spark mode or avalanche mode. The advantage of the spark mode of operation is a large signal amplitude from the chamber, the disadvantage is that there is a large dead time (msec) for the entire chamber after an event. The main advantage of the avalanche mode is high rate capability 10(exp 5) counts/mm(sup 2). A resistive-plate chamber (RPC) is similar to the PPAC in construction except that one or both of the electrodes are made from high resistivity (greater than 10(exp 10) Omega(cm) materials. In practice RPC's are usually used in the spark mode. Resistive electrodes are charged by sparks, locally reducing the actual electric field in the gap. The size of the charged surface is about 10 mm(sup 2), leaving the rest of the detector unaffected. Therefore, the rate capability of such detectors in the spark mode is considerably higher than conventional spark counters. Among the different glasses tested the best results were obtained with electron type conductive glasses, which obey Ohm's law. Most of the work with such glasses was done with high pressure parallel-plate chambers (10 atm) for time-of-flight measurements. Resistive glasses have been expensive and produced only in small quantities. Now resistive glasses are commercially available, although they are still expensive in small scale production. From the positive experience of different groups working with the resistive glasses, it was decided to review the old idea to use this glass for the RPC. This work has investigated the possibility of using the RPC at 1 atm and in the avalanche mode. This has several advantages: simplicity of construction, high rate capability, low voltage operation, and the ability to work with non-flammable gases.

  5. Enhanced absorption of the poorly soluble drug fenofibrate by tuning its release rate from ordered mesoporous silica.

    Science.gov (United States)

    Van Speybroeck, Michiel; Mellaerts, Randy; Mols, Raf; Thi, Thao Do; Martens, Johan Adriaan; Van Humbeeck, Jan; Annaert, Pieter; Van den Mooter, Guy; Augustijns, Patrick

    2010-12-23

    The aim of the present study was to evaluate the effect of release rate from ordered mesoporous silica materials on the rate and extent of absorption of the poorly soluble drug fenofibrate. Three ordered mesoporous silica materials with different pore diameter (7.3 nm, 4.4 nm and 2.7 nm) were synthesized and loaded with fenofibrate via impregnation. Release experiments were conducted under sink conditions and under supersaturating conditions in biorelevant media, simulating the fasted and the fed state. Subsequently, all silica-based formulations were evaluated in vivo (rat model). The release experiments under sink conditions indicated a clear increase in release rate with increasing pore size. However, under supersaturating conditions (FaSSIF), the, pharmaceutical performance (in terms of both the degree and duration of supersaturation), increased with decreasing pore size. The same trend was observed in vivo (fasted state): the area under the plasma concentration-time profile amounted to 102 ± 34 μMh, 86 ± 19 μMh and 20 ± 13 μMh for the materials with pore diameter of 2.7 nm, 4.4 nm and 7.3 nm, respectively. The results of this, study demonstrate that a decrease in drug release rate - and thus, a decrease of the rate at which supersaturation is created - is beneficial to the absorption of fenofibrate. Copyright © 2010 Elsevier B.V. All rights reserved.

  6. Definition of a parameter for a typical specific absorption rate under real boundary conditions of cellular phones in a GSM networkd

    Directory of Open Access Journals (Sweden)

    D. Gerhardt

    2003-01-01

    Full Text Available Using cellular phones the specific absorption rate (SAR as a physical value must observe established and internationally defined levels to guarantee human protection. To assess human protection it is necessary to guarantee safety under worst-case conditions (especially maximum transmitting power using cellular phones. To evaluate the exposure to electromagnetic fields under normal terms of use of cellular phones the limitations of the specific absorption rate must be pointed out. In a mobile radio network normal terms of use of cellular phones, i.e. in interconnection with a fixed radio transmitter of a mobile radio network, power control of the cellular phone as well as the antenna diagram regarding a head phantom are also significant for the real exposure. Based on the specific absorption rate, the antenna diagram regarding a head phantom and taking into consideration the power control a new parameter, the typical absorption rate (SARtyp, is defined in this contribution. This parameter indicates the specific absorption rate under average normal conditions of use. Constant radio link attenuation between a cellular phone and a fixed radio transmitter for all mobile models tested was assumed in order to achieve constant field strength at the receiving antenna of the fixed radio transmitter as a result of power control. The typical specific absorption rate is a characteristic physical value of every mobile model. The typical absorption rate was calculated for 16 different mobile models and compared with the absorption rate at maximum transmitting power. The results confirm the relevance of the definition of this parameter (SARtyp as opposed to the specific absorption rate as a competent and applicable method to establish the real mean exposure from a cellular phone in a mobile radio network. The typical absorption rate provides a parameter to assess electromagnetic fields of a cellular phone that is more relevant to the consumer.

  7. [Study of high temperature water vapor concentration measurement method based on absorption spectroscopy].

    Science.gov (United States)

    Chen, Jiu-ying; Liu, Jian-guo; He, Jun-feng; He, Ya-bai; Zhang, Guang-le; Xu, Zhen-yu; Gang, Qiang; Wang, Liao; Yao, Lu; Yuan, Song; Ruan, Jun; Dai, Yun-hai; Kan, Rui-feng

    2014-12-01

    Tunable diode laser absorption spectroscopy (TDLAS) has been developed to realize the real-time and dynamic measurement of the combustion temperature, gas component concentration, velocity and other flow parameters, owing to its high sensitivity, fast time response, non-invasive character and robust nature. In order to obtain accurate water vapor concentration at high temperature, several absorption spectra of water vapor near 1.39 μm from 773 to 1273 K under ordinary pressure were recorded in a high temperature experiment setup using a narrow band diode laser. The absorbance of high temperature absorption spectra was calculated by combined multi-line nonlinear least squares fitting method. Two water vapor absorption lines near 7154.35 and 7157.73 cm(-1) were selected for measurement of water vapor at high temperature. A model method for high temperature water vapor concentration was first proposed. Water vapor concentration from the model method at high temperature is in accordance with theoretical reasoning, concentration measurement standard error is less than 0.2%, and the relative error is less than 6%. The feasibility of this measuring method is verified by experiment.

  8. FDTD chiral brain tissue model for specific absorption rate determination under radiation from mobile phones at 900 and 1800 MHz

    Science.gov (United States)

    Zamorano, M.; Torres-Silva, H.

    2006-04-01

    A new electrodynamics model formed by chiral bioplasma, which represents the human head inner structure and makes it possible to analyse its behaviour when it is irradiated by a microwave electromagnetic field from cellular phones, is presented. The finite-difference time-domain (FDTD) numeric technique is used, which allows simulation of the electromagnetic fields, deduced with Maxwell's equations, and allows us to simulate the specific absorption rate (SAR). The results show the SAR behaviour as a function of the input power and the chirality factor. In considering the chiral brain tissue in the proposed human head model, the two more important conclusions of our work are the following: (a) the absorption of the electromagnetic fields from cellular phones is stronger, so the SAR coefficient is higher than that using the classical model, when values of the chiral factor are of order of 1; (b) 'inverse skin effect' shows up at 1800 MHz, with respect to a 900 MHz source.

  9. High-energy, high-rate materials processing

    Science.gov (United States)

    Marcus, H. L.; Bourell, D. L.; Eliezer, Z.; Persad, C.; Weldon, W.

    1987-12-01

    The increasingly available range of pulsed-power, high energy kinetic storage devices, such as low-inductance pulse-forming networks, compulsators, and homopolar generators, is presently considered as a basis for industrial high energy/high rate (HEHR) processing to accomplish shock hardening, drilling, rapid surface alloying and melting, welding and cutting, transformation hardening, and cladding and surface melting in metallic materials. Time-temperature-transformation concepts furnish the basis for a fundamental understanding of the potential advantages of this direct pulsed power processing. Attention is given to the HEHR processing of a refractory molybdenum alloy, a nickel-base metallic glass, tungsten, titanium aluminides, and metal-matrix composites.

  10. Transient absorption and photocurrent microscopy show that hot electron supercollisions describe the rate-limiting relaxation step in graphene.

    Science.gov (United States)

    Graham, Matt W; Shi, Su-Fei; Wang, Zenghui; Ralph, Daniel C; Park, Jiwoong; McEuen, Paul L

    2013-01-01

    Using transient absorption (TA) microscopy as a hot electron thermometer, we show that disorder-assisted acoustic-phonon supercollisions (SCs) best describe the rate-limiting relaxation step in graphene over a wide range of lattice temperatures (Tl = 5-300 K), Fermi energies (E(F) = ± 0.35 eV), and optical probe energies (~0.3-1.1 eV). Comparison with simultaneously collected transient photocurrent, an independent hot electron thermometer, confirms that the rate-limiting optical and electrical response in graphene are best described by the SC-heat dissipation rate model, H = A(T(e)(3) - T(l)(3)). Our data further show that the electron cooling rate in substrate-supported graphene is twice as fast as in suspended graphene sheets, consistent with SC model prediction for disorder.

  11. High-Frame-Rate Oil Film Interferometry

    CERN Document Server

    White, Jonathan C; Chen, John

    2010-01-01

    The fluid dynamics video to which this abstract relates contains visualization of the response of a laminar boundary layer to a sudden puff from a small hole. The boundary layer develops on a flat plate in a wind tunnel; the hole is located at a streamwise Reynolds number of 100,000. The visualization of the boundary layer response is accomplished using interferometry of a transparent, thin film of oil placed on the surface immediately downstream of the hole and with its leading edge perpendicular to the direction of flow. Through lubrication theory, it is understood that the rate of change of the spacing of the interference fringes is proportional to the skin friction at any instant. For reference, a small disk-shaped protrusion of the type often used to trip the boundary layer in wind model tunnel testing is also shown. Three cases with different puff strengths are included. Using a high-speed commercial camera, frame rates in excess of 1000/sec have been recorded; the video shown here was taken at 24 frame...

  12. High spin rate magnetic controller for nanosatellites

    Science.gov (United States)

    Slavinskis, A.; Kvell, U.; Kulu, E.; Sünter, I.; Kuuste, H.; Lätt, S.; Voormansik, K.; Noorma, M.

    2014-02-01

    This paper presents a study of a high rate closed-loop spin controller that uses only electromagnetic coils as actuators. The controller is able to perform spin rate control and simultaneously align the spin axis with the Earth's inertial reference frame. It is implemented, optimised and simulated for a 1-unit CubeSat ESTCube-1 to fulfil its mission requirements: spin the satellite up to 360 deg s-1 around the z-axis and align its spin axis with the Earth's polar axis with a pointing error of less than 3°. The attitude of the satellite is determined using a magnetic field vector, a Sun vector and angular velocity. It is estimated using an Unscented Kalman Filter and controlled using three electromagnetic coils. The algorithm is tested in a simulation environment that includes models of space environment and environmental disturbances, sensor and actuator emulation, attitude estimation, and a model to simulate the time delay caused by on-board calculations. In addition to the normal operation mode, analyses of reduced satellite functionality are performed: significant errors of attitude estimation due to non-operational Sun sensors; and limited actuator functionality due to two non-operational coils. A hardware-in-the-loop test is also performed to verify on-board software.

  13. High readmission rate after heart valve surgery

    DEFF Research Database (Denmark)

    Sibilitz, K L; Berg, S K; Thygesen, Lau Caspar;

    2015-01-01

    of anxiety and depression were present in 13.6% and 13.8%, respectively (Hospital Anxiety and Depression Scale score ≥ 8). Twelve months following discharge, 483 persons (56%) were readmitted. Readmission was associated with lower self-reported health (SF-36 PCS: 46.5 vs. 43.9, and MCS 52.2 vs. 50.7). Higher...... after surgery (3.2 (1.2-8.9)) predicted mortality. CONCLUSIONS: 6-12 months after heart valve surgery the readmission rate is high and the self-reported health status is low. Readmission is associated with low self-reported health. Therefore, targeted follow-up strategies post-surgery are needed....

  14. Comparing the rates of absorption and weight loss during a desorption test using near infrared spectroscopy.

    Science.gov (United States)

    Qassem, M; Kyriacou, P A

    2013-05-01

    The importance of determining skin hydration has over the years prompt the development of many instruments and methods, specifically designed to assess this parameter or water contents especially in the stratum corneum, and have greatly matured to suit different anatomical sites and measure multiple attributes. Of those, Near Infrared Spectroscopy (NIRS) has gained wide interest as a precise, safe, fast and noninvasive technique for determining skin hydration due to its high sensitivity to hydrogen bonding and ability to measure the amount of water in skin directly using the intensities of overtone and combination bands of OH and HOH water bonds occurring in the NIR region, that are good indicators of the state of skin hydration. This paper reports near infrared spectrophotometric measurements using a highly sophisticated spectrophotometer in the region of 1000-2500 nm to study the water uptake and dehydration properties of skin in vitro using samples of porcine skin. Initial results of pure liquid water and skin samples have clearly displayed the prominent bands associated with water content, and desorption tests have been able to verify changes in these bands associated with water content, although a clear correlation between the rates of weight loss and absorbance loss at various hydration periods has not yet been established. These preliminary results are expected to further explain the relationship between water and skin, and its role within, in hope to aid the future development of a portable instrument based on near infrared spectroscopy that would be capable of directly measuring skin hydration and/or water content in a fast and noninvasive manner.

  15. Consideration of wear rates at high velocity

    Science.gov (United States)

    Hale, Chad S.

    The development of the research presented here is one in which high velocity relative sliding motion between two bodies in contact has been considered. Overall, the wear environment is truly three-dimensional. The attempt to characterize three-dimensional wear was not economically feasible because it must be analyzed at the micro-mechanical level to get results. Thus, an engineering approximation was carried out. This approximation was based on a metallographic study identifying the need to include viscoplasticity constitutive material models, coefficient of friction, relationships between the normal load and velocity, and the need to understand wave propagation. A sled test run at the Holloman High Speed Test Track (HHSTT) was considered for the determination of high velocity wear rates. In order to adequately characterize high velocity wear, it was necessary to formulate a numerical model that contained all of the physical events present. The experimental results of a VascoMax 300 maraging steel slipper sliding on an AISI 1080 steel rail during a January 2008 sled test mission were analyzed. During this rocket sled test, the slipper traveled 5,816 meters in 8.14 seconds and reached a maximum velocity of 1,530 m/s. This type of environment was never considered previously in terms of wear evaluation. Each of the features of the metallography were obtained through micro-mechanical experimental techniques. The byproduct of this analysis is that it is now possible to formulate a model that contains viscoplasticity, asperity collisions, temperature and frictional features. Based on the observations of the metallographic analysis, these necessary features have been included in the numerical model, which makes use of a time-dynamic program which follows the movement of a slipper during its experimental test run. The resulting velocity and pressure functions of time have been implemented in the explicit finite element code, ABAQUS. Two-dimensional, plane strain models

  16. $\\gamma$-Ray Absorption at High Redshifts and the $\\gamma$-Ray Background

    CERN Document Server

    Stecker, F W

    1997-01-01

    We present results of a calculation of absorption of 10-500 GeV gamma-rays at high redshifts. This calculation requires the determination of the high- redshift evolution of the full spectral energy distribution of the intergalactic photon field. For this, we have primarily followed the recent analysis of Fall, Charlot and Pei. We give our results for the gamma-ray opacity as a function of redshift out to a redshift of 3. We then give predicted gamma-ray spectra for selected blazars and also extend our results on the background from unresolved blazars to an energy of 500 GeV. Absorption effects are predicted to significantly steepen the background spectrum above 20 GeV. Our absorption calculations can be used to place limits on the redshifts of gamma-ray bursts. Our background calculations can be used to determine the observability of multi-GeV lines from dark matter neutralino particles.

  17. Comparative QSAR studies on PAMPA/modified PAMPA for high throughput profiling of drug absorption potential with respect to Caco-2 cells and human intestinal absorption

    Science.gov (United States)

    Verma, Rajeshwar P.; Hansch, Corwin; Selassie, Cynthia D.

    2007-01-01

    Despite the dramatic increase in speed of synthesis and biological evaluation of new chemical entities, the number of compounds that survive the rigorous processes associated with drug development is low. Thus, an increased emphasis on thorough ADMET (absorption, distribution, metabolism, excretion and toxicity) studies based on in vitro and in silico approaches allows for early evaluation of new drugs in the development phase. Artificial membrane permeability measurements afford a high throughput, relatively low cost but labor intensive alternative for in vitro determination of drug absorption potential; parallel artificial membrane permeability assays have been extensively utilized to determine drug absorption potentials. The present study provides comparative QSAR analysis on PAMPA/modified PAMPA for high throughput profiling of drugs with respect to Caco-2 cells and human intestinal absorption.

  18. Upgrade Strategy for ALICE at High Rate

    CERN Document Server

    Musa, L

    2012-01-01

    The longterm goal of the ALICE experiment is to provide a precise characterization of the Quark-Gluon Plasma (QGP) state. Such a determination of its properties including initial temperature, degrees of freedom, speed of sound, and in general, transport coefficients would be a major achievement. This would go a long way towards a better understanding of QCD as a genuine multi-particle theory. To achieve this goal, high statistics measurements are required, which will give access also to the very rare physics channels needed to understand the dynamics of this condensed phase of QCD. The general upgrade strategy for the ALICE central barrel is conceived to deal with this challenge with expected Pb-Pb interaction rates of up to 50 kHz, that would provide an accumulated sample of the order of 10 nb^-1 in the period 2019-2023. In this document we sketch the modifications/replacements needed in all ALICE central barrel detectors and online systems (Trigger, DAQ and HLT) for high luminosity running. As the ALICE for...

  19. Effect of microplastic deformation on the electron ultrasonic absorption in high-purity molybdenum monocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Pal' -Val' , P.P. (AN Ukrainskoj SSR, Kharkov. Fiziko-Tekhnicheskij Inst. Nizkikh Temperatur); Kaufmann, Kh.J. (Akademie der Wissenschaften der DDR, Berlin)

    1983-03-01

    The low temperature (100-6 K) linear absorption of ultrasound (88 kHz) by high purity molybdenum single crystals have been studied. Both unstrained samples and samples subjected to microplastic deformation (epsilon<=0.45%) were used. Unstrained samples displayed at T<30 K a rapid increase in the absorption with lowering temperature which is interpreted as an indication of electron viscosity due to electron-phonon collisions. After deformation this part of absorption disappeared. This seems to suggest that microplastic deformation brings about in the crystal a sufficiently large number of defects that can compete with phonons in restricting the electron mean free path. A low temperature ''dynamic annealing'' has been revealed in strained samples, that is, almost complete recovery of the absorption nature under irradiation with high amplitude sound, epsilon/sub 0/ approximately 10/sup -4/, during 10 min, at 6 K. A new relaxation peak of absorption at 10 K has been found in strained samples.

  20. Interstellar dust grain composition from high-resolution X-ray absorption edge structure

    Science.gov (United States)

    Corrales, Lia

    2016-06-01

    X-ray light is sufficient to excite electrons from n=1 (K-shell) and n=2 (L-shell) energy levels of neutral interstellar metals, causing a sharp increase in the absorption cross-section. Near the ionization energy, the shape of the photoelectric absorption edge depends strongly on whether the atom is isolated or bound in molecules or minerals (dust). With high resolution X-ray spectroscopy, we can directly measure the state of metals and the mineral composition of dust in the interstellar medium. In addition, the scattering contribution to the X-ray extinction cross-section can be used to gauge grain size, shape, and filling factor. In order to fully take advantage of major advances in high resolution X-ray spectroscopy, lab measurements of X-ray absorption fine structure (XAFS) from suspected interstellar minerals are required. Optical constants derived from the absorption measurements can be used with Mie scattering or anomalous diffraction theory in order to model the full extinction cross-sections from the interstellar medium. Much like quasar spectra are used to probe other intergalactic gas, absorption spectroscopy of Galactic X-ray binaries and bright stars will yield key insights to the mineralogy and evolution of dust grains in the Milky Way.

  1. Study of Electromagnetic Radiation and Specific Absorption Rate of Mobile Phones with Fractional Human Head Models via Green's Functions

    Directory of Open Access Journals (Sweden)

    Nookala S. Rao

    2011-01-01

    Full Text Available Problem statement: Electromagnetic Radiation from mobile hand set is identified as one of the side effects for increasing rate of brain tumor. Due to this reason, Mobile phone industries are attentive towards safety issues of human health. Specific Absorption Rate is one of the important parameter while modeling the radiation effect on human head. Brain material with homogeneity is treated as an equivalent model of human head. The radiation caused by antennas mounted on mobile set is assumed to be monopolar. Approach: Apart from the Specific Absorption Rate, period of exposure to radiation is an extremely important parameter while assessing the effects on brain tissue. Correlation between the amount of radiation versus spherical model of brain is a complex phenomena, addressed in various simulation models. In the present work the field distribution inside the head are modeled using Dyadic Greens Functions while describing the effect of radiation pattern. Multilayered homogeneous lossy spherical model is proposed as an equivalent to head. Results: In this paper we present the depth of penetration of radiation and its effect on brain tissue. In essence the amount of electromagnetic power absorbed by biological tissues for various exposure conditions and types of emitting sources, utilizing a detailed model of the human head. Conclusion: Bio-heat equation is used to predict heat distribution inside the brain when exposed to radiation. The medium is assumed to be homogeneous, isotropic, linear, non dispersive and stationary. A critical evaluation of the method is discussed.

  2. On the development of high temperature ammonia-water hybrid absorption-compression heat pumps

    DEFF Research Database (Denmark)

    Jensen, Jonas Kjær; Markussen, Wiebke Brix; Reinholdt, Lars

    2015-01-01

    Ammonia-water hybrid absorption-compression heat pumps (HACHP) are a promising technology for development of ecient high temperature industrial heat pumps. Using 28 bar components HACHPs up to 100 °C are commercially available. Components developed for 50 bar and 140 bar show that these pressure...

  3. High Pressure X-ray Absorption Studies on Correlated-Electron Systems

    Energy Technology Data Exchange (ETDEWEB)

    Cornelius, Andrew L. [Univ. of Nevada, Las Vegas, NV (United States)

    2016-08-26

    This project used high pressure to alter the electron-electron and electron-lattice interactions in rare earth and actinide compounds. Knowledge of these properties is the starting points for a first-principles understanding of electronic and electronically related macroscopic properties. The research focused on a systematic study of x-ray absorption measurements on rare earth and actinide compounds.

  4. On high-redshift quasar absorption spectra and the Riemannian geometry of the Universe

    CERN Document Server

    Palle, D

    2001-01-01

    We study the observed small deviations of high-redshift absorption spectra that are interpreted as a possible evidence for a variable fine structure constant. On the contrary, we claim that the effect could be completely attributed to the small amount of cosmic shear beyond the standard Friedmann expanding Universe.

  5. High-resolution absorption cross sections of C$_{2}$H$_{6}$ at elevated temperatures

    CERN Document Server

    Hargreaves, Robert J; Dulick, Michael; Bernath, Peter F

    2015-01-01

    Infrared absorption cross sections near 3.3 $\\mu$m have been obtained for ethane, C$_{2}$H$_{6}$. These were acquired at elevated temperatures (up to 773 K) using a Fourier transform infrared spectrometer and tube furnace with a resolution of 0.005 cm$^{-1}$. The integrated absorption was calibrated using composite infrared spectra taken from the Pacific Northwest National Laboratory (PNNL). These new measurements are the first high-resolution infrared C$_{2}$H$_{6}$ cross sections at elevated temperatures.

  6. Cholesterol absorption and excretion in ileostomy subjects on high- and low-dietary-cholesterol intakes.

    Science.gov (United States)

    Ellegård, L; Bosaeus, I

    1994-01-01

    Six healthy ileostomy subjects were given [3H]cholesterol and [14C]beta-sitosterol in a single meal together with two controlled diets containing 150 or 450 mg cholesterol/d. Each diet was eaten for 3 d. Cholesterol absorption and excretion of cholesterol, bile acids, fat, energy, and nitrogen were analyzed. Fractional cholesterol absorption increased from 44 +/- 2.6% (mean +/- SE) to 61 +/- 3.4% (P effluent, or excretion of energy, nitrogen, fat, and bile acids did not differ between periods. Endogenous cholesterol excretion remained unchanged whereas net cholesterol excretion (output minus intake) was 37% higher (P < 0.05) on low compared with high cholesterol intake.

  7. Broadband Two-Photon Absorption Characteristics of Highly Photostable Fluorenyl-Dicyanoethylenylated [60]Fullerene Dyads

    Directory of Open Access Journals (Sweden)

    Seaho Jeon

    2016-05-01

    Full Text Available We synthesized four C60-(light-harvesting antenna dyads C60 (>CPAF-Cn (n = 4, 9, 12, or 18 1-Cn for the investigation of their broadband nonlinear absorption effect. Since we have previously demonstrated their high function as two-photon absorption (2PA materials at 1000 nm, a different 2PA wavelength of 780 nm was applied in the study. The combined data taken at two different wavelength ranges substantiated the broadband characteristics of 1-Cn. We proposed that the observed broadband absorptions may be attributed by a partial π-conjugation between the C60 > cage and CPAF-Cn moieties, via endinitrile tautomeric resonance, giving a resonance state with enhanced molecular conjugation. This transient state could increase its 2PA and excited-state absorption at 800 nm. In addition, a trend of concentration-dependent 2PA cross-section (σ2 and excited-state absorption magnitude was detected showing a higher σ value at a lower concentration that was correlated to increasing molecular separation with less aggregation for dyads C60(>CPAF-C18 and C60(>CPAF-C9, as better 2PA and excited-state absorbers.

  8. O absorption measurements in an engineering-scale high-pressure coal gasifier

    Science.gov (United States)

    Sun, Kai; Sur, Ritobrata; Jeffries, Jay B.; Hanson, Ronald K.; Clark, Tommy; Anthony, Justin; Machovec, Scott; Northington, John

    2014-10-01

    A real-time, in situ water vapor (H2O) sensor using a tunable diode laser near 1,352 nm was developed to continuously monitor water vapor in the synthesis gas of an engineering-scale high-pressure coal gasifier. Wavelength-scanned wavelength-modulation spectroscopy with second harmonic detection (WMS-2 f) was used to determine the absorption magnitude. The 1 f-normalized, WMS-2 f signal (WMS-2 f/1 f) was insensitive to non-absorption transmission losses including beam steering and light scattering by the particulate in the synthesis gas. A fitting strategy was used to simultaneously determine the water vapor mole fraction and the collisional-broadening width of the transition from the scanned 1 f-normalized WMS-2 f waveform at pressures up to 15 atm, which can be used for large absorbance values. This strategy is analogous to the fitting strategy for wavelength-scanned direct absorption measurements. In a test campaign at the US National Carbon Capture Center, the sensor demonstrated a water vapor detection limit of ~800 ppm (25 Hz bandwidth) at conditions with more than 99.99 % non-absorption transmission losses. Successful unattended monitoring was demonstrated over a 435 h period. Strong correlations between the sensor measurements and transient gasifier operation conditions were observed, demonstrating the capability of laser absorption to monitor the gasification process.

  9. Low and High Ionization Absorption Properties of Mg II Absorption-Selected Galaxies at Intermediate Redshifts; 1, General Properties

    CERN Document Server

    Churchill, C W; Charlton, J C; Jannuzi, B T; Kirhakos, S; Steidel, C C; Schneider, D P; Churchill, Christopher W.; Mellon, Richard R.; Charlton, Jane C.; Jannuzi, Buell T.; Kirhakos, Sofia; Steidel, Charles C.; Schneider, Donald P.

    2000-01-01

    We present extensive metal-line absorption properties for 45 absorption systems that were selected by their Mg II absorption at redshifts between 0.4 and 1.4. For each system the properties of several chemical species are determined, including a wide range of ionization conditions. In the optical, the absorption systems have been observed at ~6 km/s resolution with HIRES/Keck, which covered Mg II, several Fe II transitions, Mg I, and in some cases (depending upon redshift), Ca II, Ti II, Mn II, and Al III. Ultraviolet, lower resolution (~230 km/s) Faint Object Spectrograph data (1600 - 3275 Ang) were obtained from the Hubble Space Telescope archive. These spectra covered Al II, Al III, Si II, Si III, Si IV, C II, C III, C IV, N V, O VI, and several Lyman series transitions, with coverage dependent upon the absorption system redshift. From these data, we infer that Mg II absorbing galaxies at intermediate redshifts have multiphase gaseous structures.

  10. High-speed neutron radiography for monitoring the water absorption by capillarity in porous materials

    Science.gov (United States)

    Cnudde, Veerle; Dierick, Manuel; Vlassenbroeck, Jelle; Masschaele, Bert; Lehmann, Eberhard; Jacobs, Patric; Van Hoorebeke, Luc

    2008-01-01

    Fluid flow through porous natural building stones is of great importance when studying their weathering processes. Many traditional experiments based on mass changes are available for studying liquid transport in porous stones, such as the determination of the water absorption coefficient by capillarity. Because thermal neutrons experience a strong attenuation by hydrogen, neutron radiography is a suitable technique for the study of water absorption by capillarity in porous stones. However, image contrast can be impaired because hydrogen mainly scatters neutrons rather than absorbing them, resulting in a blurred image. Capillarity results obtained by neutron radiography and by the European Standard 1925 for the determination of the water absorption coefficient by capillarity for natural building stones with a variable porosity were compared. It is illustrated that high-speed neutron radiography can be a useful research tool for the visualization of internal fluid flow inside inorganic building materials such as limestones and sandstones.

  11. VUV-absorption cross section of CO2 at high temperatures and impact on exoplanet atmospheres

    CERN Document Server

    Venot, Olivia; Bénilan, Yves; Gazeau, Marie-Claire; Hébrard, Eric; Larcher, Gwenaelle; Schwell, Martin; Dobrijevic, Michel; Selsis, Franck

    2015-01-01

    Ultraviolet (UV) absorption cross sections are an essential ingredient of photochemical atmosphere models. Exoplanet searches have unveiled a large population of short-period objects with hot atmospheres, very different from what we find in our solar system. Transiting exoplanets whose atmospheres can now be studied by transit spectroscopy receive extremely strong UV fluxes and have typical temperatures ranging from 400 to 2500 K. At these temperatures, UV photolysis cross section data are severely lacking. Our goal is to provide high-temperature absorption cross sections and their temperature dependency for important atmospheric compounds. This study is dedicated to CO2, which is observed and photodissociated in exoplanet atmospheres. We performed these measurements for the 115 - 200 nm range at 300, 410, 480, and 550 K. In the 195 - 230 nm range, we worked at seven temperatures between 465 and 800 K. We found that the absorption cross section of CO2 is very sensitive to temperature, especially above 160 nm....

  12. High-temperature rate constant measurements for OH+xylenes

    KAUST Repository

    Elwardani, Ahmed Elsaid

    2015-06-01

    The overall rate constants for the reactions of hydroxyl (OH) radicals with o-xylene (k 1), m-xylene (k 2), and p-xylene (k 3) were measured behind reflected shock waves over 890-1406K at pressures of 1.3-1.8atm using OH laser absorption near 306.7nm. Measurements were performed under pseudo-first-order conditions. The measured rate constants, inferred using a mechanism-fitting approach, can be expressed in Arrhenius form as:k1=2.93×1013exp(-1350.3/T)cm3mol-1s-1(890-1406K)k2=3.49×1013exp(-1449.3/T)cm3mol-1s-1(906-1391K)k3=3.5×1013exp(-1407.5/T)cm3mol-1s-1(908-1383K)This paper presents, to our knowledge, first high-temperature measurements of the rate constants of the reactions of xylene isomers with OH radicals. Low-temperature rate-constant measurements by Nicovich et al. (1981) were combined with the measurements in this study to obtain the following Arrhenius expressions, which are applicable over a wider temperature range:k1=2.64×1013exp(-1181.5/T)cm3mol-1s-1(508-1406K)k2=3.05×109exp(-400/T)cm3mol-1s-1(508-1391K)k3=3.0×109exp(-440/T)cm3mol-1s-1(526-1383K) © 2015 The Combustion Institute.

  13. Effect of water absorption by the aggregate on properties of high-strength lightweight concrete

    Energy Technology Data Exchange (ETDEWEB)

    Punkki, J.

    1995-12-31

    Recently, high-strength lightweight concrete has become an interesting building material for the offshore oil industry. This doctoral thesis presents an experimental investigation of the effect of water absorption by three different types of lightweight aggregates. One type did not show any water absorption ability at all and so represented no problem to the concrete production. For the two other high-strength aggregates, which were of more conventional types, the water absorption depended not only on the properties of the aggregates, but also on the concrete mixing procedure and the properties of the fresh cement paste. When water absorbing lightweight aggregate was used in a dry condition, the workability of the concrete was significantly reduced by the water absorption of the aggregate. This effect was not present when prewetted aggregate was used. The water absorption by the lightweight aggregate also affected the early compressive strength of concrete. After one day, dry aggregate gave on the average 10 MPa higher compressive strength than did prewetted aggregate. The strength-density ratio was affected by the moisture condition of the aggregate. Dry lightweight aggregate gave 9 MPa higher compressive strength at a density of 2000 kg/m{sup 3} compared to that of prewetted aggregate. The water absorption by the lightweight also affected the microstructure of the hardened concrete. Dry lightweight aggregate gave a slightly better microstructure than normal weight aggregate. The results indicate that the use of prewetted aggregate adversely affected the transition zone between the aggregate and the cement paste. 69 refs., 58 figs., 42 tabs.

  14. Absorption properties of high-latitude Norwegian coastal water: The impact of CDOM and particulate matter

    Science.gov (United States)

    Nima, Ciren; Frette, Øyvind; Hamre, Børge; Erga, Svein Rune; Chen, Yi-Chun; Zhao, Lu; Sørensen, Kai; Norli, Marit; Stamnes, Knut; Stamnes, Jakob J.

    2016-09-01

    We present data from measurements and analyses of the spectral absorption due to colored dissolved organic matter (CDOM), total suspended matter (TSM), phytoplankton, and non-algal particles (NAP) in high-latitude northern Norwegian coastal water based on samples taken in spring, summer, and autumn. The Chlorophyll-a (Chl-a) concentration was found to vary significantly with season, whereas regardless of season CDOM was found to be the dominant absorber for wavelengths shorter than 600 nm. The absorption spectral slope S350-500 for CDOM varied between 0.011 and 0.022 nm-1 with mean value and standard deviation given by (0.015 ± 0.002) nm-1. The absorption spectral slope was found to be strongly dependent on the wavelength interval used for fitting. On average, S280-500 was found to be 43% higher than S350-500. A linear relationship was found between the base 10 logarithm of the absorption coefficient at 440 nm [log(ag(440))] and S350-500. Regardless of season, phytoplankton were the dominant component of the TSM absorption indicating little influence from land drainage. The mean values of the Chl-a specific absorption coefficient of phytoplankton aph*(λ) at 440 nm and 676 nm were 0.052 m2 mg-1 and 0.023 m2 mg-1, respectively, and aph*(λ) was found to vary with season, being higher in summer and autumn than in spring. The absorption spectral slope SNAP, which is the spectral slope of absorption spectrum for non-algal particles, was lower than that for European coastal water in general. It varied between 0.0048 and 0.022 nm-1 with mean value and standard deviation given by (0.0083-1 ± 0.003) nm-1. Comparisons of absorption coefficients measured in situ using an ac-9 instrument with those measured in the laboratory from water samples show a good agreement.

  15. Time-stretched real-time measurement technique for ultrafast absorption variations with TS/s sampling-rate.

    Science.gov (United States)

    Weber, Stefan; Waller, Erik H; Kaiser, Christoph; von Freymann, Georg

    2017-06-26

    We present a real-time measurement technique, based on time-stretching for measuring the temporal dynamic of ultrafast absorption variations with a sampling-rate of up to 1.1 TS/s. The single-shot captured data are stretched in a resonator-based time-stretch system with a variable stretch-factor of up to 13.8. The time-window of the time-stretch system for capturing the signal of interest is about 800 ps with an update-rate of 10 MHz. An adapted optical backpropagation algorithm is introduced for reconstructing the original unstretched event. As proof-of-principle the temporal characteristic of a picosecond semiconductor saturable absorber mirror is measured: The real-time results agree well with the results of a conventional pump-probe experiment. The time-stretch technique potentially allows to gain access to a large field of ultrafast absorption variations like semiconductor charge carrier dynamics, irreversible polymerization processes, and saturable absorber materials.

  16. High voltage high repetition rate pulse using Marx topology

    Science.gov (United States)

    Hakki, A.; Kashapov, N.

    2015-06-01

    The paper describes Marx topology using MOSFET transistors. Marx circuit with 10 stages has been done, to obtain pulses about 5.5KV amplitude, and the width of the pulses was about 30μsec with a high repetition rate (PPS > 100), Vdc = 535VDC is the input voltage for supplying the Marx circuit. Two Ferrite ring core transformers were used to control the MOSFET transistors of the Marx circuit (the first transformer to control the charging MOSFET transistors, the second transformer to control the discharging MOSFET transistors).

  17. Subcutaneous absorption kinetics of two highly concentrated preparations of recombinant human growth hormone

    DEFF Research Database (Denmark)

    Laursen, Torben; Jørgensen, Jens Otto Lunde; Susgaard, Søren;

    1993-01-01

    Abstract OBJECTIVE: The relative bioavailability of two highly concentrated (12 IU/ml) formulations of biosynthetic human growth hormone (GH) administered subcutaneously was compared. DESIGN: A randomized, crossover study. Conventional GH therapy was withdrawn 72 hours before each study period. T....... CONCLUSIONS: There is no significant difference between the absorption kinetics and short-term metabolic effects of these two highly concentrated formulations of biosynthetic GH. The two formulations are bioequivalent....

  18. The absorption and metabolism of a single L-menthol oral versus skin administration: Effects on thermogenesis and metabolic rate.

    Science.gov (United States)

    Valente, Angelica; Carrillo, Andres E; Tzatzarakis, Manolis N; Vakonaki, Elena; Tsatsakis, Aristidis M; Kenny, Glen P; Koutedakis, Yiannis; Jamurtas, Athanasios Z; Flouris, Andreas D

    2015-12-01

    We investigated the absorption and metabolism pharmacokinetics of a single L-menthol oral versus skin administration and the effects on human thermogenesis and metabolic rate. Twenty healthy adults were randomly distributed into oral (capsule) and skin (gel) groups and treated with 10 mg kg(-1) L-menthol (ORALMENT; SKINMENT) or control (lactose capsule: ORALCON; water application: SKINCON) in a random order on two different days. Levels of serum L-menthol increased similarly in ORALMENT and SKINMENT (p > 0.05). L-menthol glucuronidation was greater in ORALMENT than SKINMENT (p  0.05). Participants reported no cold, shivering, discomfort, stress or skin irritation. We conclude that a single L-menthol skin administration increased thermogenesis and metabolic rate in humans. These effects are minor following L-menthol oral administration probably due to faster glucuronidation and greater blood menthol glucuronide levels.

  19. HIgh Rate X-ray Fluorescence Detector

    Energy Technology Data Exchange (ETDEWEB)

    Grudberg, Peter Matthew [XIA LLC

    2013-04-30

    The purpose of this project was to develop a compact, modular multi-channel x-ray detector with integrated electronics. This detector, based upon emerging silicon drift detector (SDD) technology, will be capable of high data rate operation superior to the current state of the art offered by high purity germanium (HPGe) detectors, without the need for liquid nitrogen. In addition, by integrating the processing electronics inside the detector housing, the detector performance will be much less affected by the typically noisy electrical environment of a synchrotron hutch, and will also be much more compact than current systems, which can include a detector involving a large LN2 dewar and multiple racks of electronics. The combined detector/processor system is designed to match or exceed the performance and features of currently available detector systems, at a lower cost and with more ease of use due to the small size of the detector. In addition, the detector system is designed to be modular, so a small system might just have one detector module, while a larger system can have many you can start with one detector module, and add more as needs grow and budget allows. The modular nature also serves to simplify repair. In large part, we were successful in achieving our goals. We did develop a very high performance, large area multi-channel SDD detector, packaged with all associated electronics, which is easy to use and requires minimal external support (a simple power supply module and a closed-loop water cooling system). However, we did fall short of some of our stated goals. We had intended to base the detector on modular, large-area detectors from Ketek GmbH in Munich, Germany; however, these were not available in a suitable time frame for this project, so we worked instead with pnDetector GmbH (also located in Munich). They were able to provide a front-end detector module with six 100 m^2 SDD detectors (two monolithic arrays of three elements each) along with

  20. Time variations of narrow absorption lines in high resolution quasar spectra

    CERN Document Server

    Boissé, P; Prochaska, J X; Péroux, C; York, D G

    2015-01-01

    Aims. We have searched for temporal variations of narrow absorption lines in high resolution quasar spectra. A sample of 5 distant sources have been assembled, for which 2 spectra - VLT/UVES or Keck/HIRES - taken several years apart are available. Methods. We first investigate under which conditions variations in absorption line profiles can be detected reliably from high resolution spectra, and discuss the implications of changes in terms of small-scale structure within the intervening gas or intrinsic origin. The targets selected allow us to investigate the time behavior of a broad variety of absorption line systems, sampling diverse environments: the vicinity of active nuclei, galaxy halos, molecular-rich galaxy disks associated with damped Lya systems, as well as neutral gas within our own Galaxy. Results. Absorption lines from MgII, FeII or proxy species with lines of lower opacity tracing the same kind of gas appear to be remarkably stable (1 sigma upper limits as low as 10 % for some components on scal...

  1. Sensitivity of MENA Tropical Rainbelt to Dust Shortwave Absorption: A High Resolution AGCM Experiment

    KAUST Repository

    Bangalath, Hamza Kunhu

    2016-06-13

    Shortwave absorption is one of the most important, but the most uncertain, components of direct radiative effect by mineral dust. It has a broad range of estimates from different observational and modeling studies and there is no consensus on the strength of absorption. To elucidate the sensitivity of the Middle East and North Africa (MENA) tropical summer rainbelt to a plausible range of uncertainty in dust shortwave absorption, AMIP-style global high resolution (25 km) simulations are conducted with and without dust, using the High-Resolution Atmospheric Model (HiRAM). Simulations with dust comprise three different cases by assuming dust as a very efficient, standard and inefficient absorber. Inter-comparison of these simulations shows that the response of the MENA tropical rainbelt is extremely sensitive to the strength of shortwave absorption. Further analyses reveal that the sensitivity of the rainbelt stems from the sensitivity of the multi-scale circulations that define the rainbelt. The maximum response and sensitivity are predicted over the northern edge of the rainbelt, geographically over Sahel. The sensitivity of the responses over the Sahel, especially that of precipitation, is comparable to the mean state. Locally, the response in precipitation reaches up to 50% of the mean, while dust is assumed to be a very efficient absorber. Taking into account that Sahel has a very high climate variability and is extremely vulnerable to changes in precipitation, the present study suggests the importance of reducing uncertainty in dust shortwave absorption for a better simulation and interpretation of the Sahel climate.

  2. Supersaturation induced by Itraconazole/Soluplus® micelles provided high GI absorption in vivo

    Directory of Open Access Journals (Sweden)

    Yue Zhong

    2016-04-01

    Full Text Available To investigate the effect of supersaturation induced by micelle formation during dissolution on the bioavailability of itraconazole (ITZ/Soluplus® solid dispersion. Solid dispersions prepared by hot melt extrusion (HME were compressed into tablets directly with other excipients. Dissolution behavior of ITZ tablets was studied by dissolution testing and the morphology of micelles in dissolution media was studied using transmission electron microscopy (TEM. Drug transferring from stomach into intestine was simulated to obtain a supersaturated drug solution. Bioavailability studies were performed on the ITZ tablets and Sporanox® in beagle dogs. The morphology of micelles in the dissolution media was observed to be spherical in shape, with an average size smaller than 100 nm. The supersaturated solutions formed by Soluplus® micelles were stable and no precipitation took place over a period of 180 min. Compared with Sporanox®, ITZ tablets exhibited a 2.50-fold increase in the AUC(0–96 of ITZ and a 1.95-fold increase in its active metabolite hydroxyitraconazole (OH-ITZ in the plasma of beagle dogs. The results obtained provided clear evidence that not only the increase in the dissolution rate in the stomach, but also the supersaturation produced by micelles in the small intestine may be of great assistance in the successful development of poorly water-soluble drugs. The micelles formed by Soluplus® enwrapped the molecular ITZ inside the core which promoted the amount of free drug in the intestinal cavity and carried ITZ through the aqueous boundary layer (ABL, resulting in high absorption by passive transportation across biological membranes. The uptake of intact micelles through pinocytosis together with the inhibition of P-glycoprotein-mediated drug efflux in intestinal epithelia contributed to the absorption of ITZ in the gastrointestinal tract. These results indicate that HME with Soluplus®, which can induce supersaturation by micelle

  3. Cheetah: A high frame rate, high resolution SWIR image camera

    Science.gov (United States)

    Neys, Joel; Bentell, Jonas; O'Grady, Matt; Vermeiren, Jan; Colin, Thierry; Hooylaerts, Peter; Grietens, Bob

    2008-10-01

    A high resolution, high frame rate InGaAs based image sensor and associated camera has been developed. The sensor and the camera are capable of recording and delivering more than 1700 full 640x512pixel frames per second. The FPA utilizes a low lag CTIA current integrator in each pixel, enabling integration times shorter than one microsecond. On-chip logics allows for four different sub windows to be read out simultaneously at even higher rates. The spectral sensitivity of the FPA is situated in the SWIR range [0.9-1.7 μm] and can be further extended into the Visible and NIR range. The Cheetah camera has max 16 GB of on-board memory to store the acquired images and transfer the data over a Gigabit Ethernet connection to the PC. The camera is also equipped with a full CameralinkTM interface to directly stream the data to a frame grabber or dedicated image processing unit. The Cheetah camera is completely under software control.

  4. High photovoltage in perovskite solar cells: New physical insights from the ultrafast transient absorption spectroscopy

    Science.gov (United States)

    Dar, M. Ibrahim; Franckevičius, Marius; Arora, Neha; Redeckas, Kipras; Vengris, Mikas; Gulbinas, Vidmantas; Zakeeruddin, Shaik Mohammed; Grätzel, Michael

    2017-09-01

    To understand the cause of the high open circuit photovoltage (VOC) achieved by todays' state of the art perovskite solar cells (PSCs), we examine formamidinium lead bromide CH(NH2)2PbBr3 films by ultrafast transient absorption spectroscopy (TAS). By using TiO2 and spiro-OMeTAD as charge extraction layers, the devices based on the CH(NH2)2PbBr3 films yield VOC as high as 1.5 V ascertaining their high quality. TAS establish that the presence of charge extraction layers has very little influences on the nature of a negative band at 535 nm corresponding to the bleaching of the absorption band edge and two positive bands in the CH(NH2)2PbBr3 films. Therefore, we contend that the VOC in PSC is predominantly determined by the quasi Fermi level splitting within the perovskite layer.

  5. A new cell for X-ray absorption spectroscopy study under high pressure

    Institute of Scientific and Technical Information of China (English)

    ZHENG Li-Rong; CHE Rong-Zheng; LIU Jing; DU Yong-Hua; ZHOU Ying-Li; HU Tian-Dou

    2009-01-01

    X-ray absorption fine structure (XAFS) spectroscopy is a powerful technique for the investigation of the local environment around selected atoms in condensed matter. XAFS under pressure is an important method for the synchrotron source. We design a cell for a high pressure XAFS experiment. Sintered boron carbide is used as the anvils of this high pressure cell in order to obtain a full XAFS spectrum free from diffraction peaks. In addition, a hydraulic pump was adopted to make in-suit pressure modulation. High quality XAFS spectra of ZrH2 under high pressure (up to 13 Gpa) were obtained by this cell.

  6. Improved Shock Tube Measurement of the CH4 + Ar = CH3 + H + Ar Rate Constant using UV Cavity-Enhanced Absorption Spectroscopy of CH3.

    Science.gov (United States)

    Wang, Shengkai; Davidson, David F; Hanson, Ronald K

    2016-07-21

    We report an improved measurement for the rate constant of methane dissociation in argon (CH4 + Ar = CH3 + H + Ar) behind reflected shock waves. The experiment was conducted using a sub-parts per million sensitivity CH3 diagnostic recently developed in our laboratory based on ultraviolet cavity-enhanced absorption spectroscopy. The high sensitivity of this diagnostic allowed for measurements of quantitatively resolved CH3 time histories during the initial stage of CH4 pyrolysis, where the reaction system is clean and free from influences of secondary reactions and temperature change. This high sensitivity also allowed extension of our measurement range to much lower temperatures (shock measurements were performed at temperatures between 1487 and 1866 K and pressures near 1.7 atm, resulting in the following Arrhenius rate constant expression for the title reaction: k(1.7 atm) = 3.7 × 10(16) exp(-42 200 K/T) cm(3)/mol·s, with a 2σ uncertainty factor of 1.25. The current data are in good consensus with various theoretical and review studies, but at the low temperature end they suggest a slightly higher (up to 35%) rate constant compared to these previous results. A re-evaluation of previous and current experimental data in the falloff region was also performed, yielding updated expressions for both the low-pressure limit and the high-pressure limit rate constants and improved agreement with all existing data.

  7. Development of a carbonate absorption-based process for post-combustion CO2 capture: The role of biocatalyst to promote CO2 absorption rate

    Science.gov (United States)

    Lu, Y.; Ye, X.; Zhang, Z.; Khodayari, A.; Djukadi, T.

    2011-01-01

    An Integrated Vacuum Carbonate Absorption Process (IVCAP) for post-combustion carbon dioxide (CO2) capture is described. IVCAP employs potassium carbonate (PC) as a solvent, uses waste or low quality steam from the power plant for CO2 stripping, and employs a biocatalyst, carbonic anhydrase (CA) enzyme, for promoting the CO2 absorption into PC solution. A series of experiments were performed to evaluate the activity of CA enzyme mixed in PC solutions in a stirred tank reactor system under various temperatures, CA dosages, CO2 loadings, CO2 partial pressures, and the presence of major flue gas contaminants. It was demonstrated that CA enzyme is an effective biocatalyst for CO2 absorption under IVCAP conditions. ?? 2011 Published by Elsevier Ltd.

  8. Cellulose/inorganic-composite fibers for producing textile fabrics of high X-ray absorption properties

    Energy Technology Data Exchange (ETDEWEB)

    Günther, Karoline; Giebing, Christina; Askani, Antonia [FTB, Hochschule Niederrhein – University of Applied Science, Faculty of Textile and Clothing Technology, Webschulstr. 31, 41065 Mönchengladbach (Germany); Leisegang, Tilmann [Saxray GmbH, Maria-Reiche-Str. 1, 01109 Dresden (Germany); Krieg, Marcus [TITK, Thüringisches Institut für Textil- und Kunststoff-Forschung e.V., Breitscheidstraße 97, 07407 Rudolstadt (Germany); Kyosev, Yordan; Weide, Thomas [FTB, Hochschule Niederrhein – University of Applied Science, Faculty of Textile and Clothing Technology, Webschulstr. 31, 41065 Mönchengladbach (Germany); Mahltig, Boris, E-mail: Boris.Mahltig@hs-niederrhein.de [FTB, Hochschule Niederrhein – University of Applied Science, Faculty of Textile and Clothing Technology, Webschulstr. 31, 41065 Mönchengladbach (Germany)

    2015-11-01

    Common textile materials as cotton or polyester do not possess reliable X-ray absorption properties. This is due to their morphology and chemical composition in particular. Common fibers are built up from organic polymers containing mainly the elements carbon, hydrogen, oxygen and nitrogen. These “light” elements only have low X-ray absorption coefficients. In contrast, inorganic materials composed of “heavy” elements with high atomic numbers, e.g. barium or bismuth, exhibit X-ray absorption coefficients higher by up to two orders of magnitude. To obtain a flexible yarn with high X-ray absorption properties both these materials, the organic polymer and the inorganic X-ray absorber, are combined to an inorganic/organic composite fiber material. Hence, as the organic component cellulose from modified Lyocell-process is used as carrier fiber and blended with inorganic absorber particles of low toxicity and high absorption coefficients, as bariumsulphate, bariumtitanate or bismuthoxide. A content of inorganic absorber particles equally distributed in the whole fiber of up to 20% is achieved. The composite fibers are produced as staple or filament fibers and processed to multifilament or staple fiber yarns. The staple fiber yarns are rotor-spinned to increase the comfort of the subsequent textile material. Several woven fabrics, considering multilayer structure and different warp/weft density, are developed. The energy dependent X-ray shielding properties are determined in dependence on the different yarn compositions, yarn types and structural parameters of the woven fabrics. As a result, a production process of textile materials with comfortable and dedicated X-ray absorption properties is established. It offers a promising opportunity for manufacturing of specialized textiles, working clothes or uniforms applicable for medicine, air craft and security personal, mining as well as for innovative composite materials. - Highlights: • Preparation of cellulosic

  9. Bulk damage and absorption in fused silica due to high-power laser applications

    Science.gov (United States)

    Nürnberg, F.; Kühn, B.; Langner, A.; Altwein, M.; Schötz, G.; Takke, R.; Thomas, S.; Vydra, J.

    2015-11-01

    Laser fusion projects are heading for IR optics with high broadband transmission, high shock and temperature resistance, long laser durability, and best purity. For this application, fused silica is an excellent choice. The energy density threshold on IR laser optics is mainly influenced by the purity and homogeneity of the fused silica. The absorption behavior regarding the hydroxyl content was studied for various synthetic fused silica grades. The main absorption influenced by OH vibrational excitation leads to different IR attenuations for OH-rich and low-OH fused silica. Industrial laser systems aim for the maximum energy extraction possible. Heraeus Quarzglas developed an Yb-doped fused silica fiber to support this growing market. But the performance of laser welding and cutting systems is fundamentally limited by beam quality and stability of focus. Since absorption in the optical components of optical systems has a detrimental effect on the laser focus shift, the beam energy loss and the resulting heating has to be minimized both in the bulk materials and at the coated surfaces. In collaboration with a laser research institute, an optical finisher and end users, photo thermal absorption measurements on coated samples of different fused silica grades were performed to investigate the influence of basic material properties on the absorption level. High purity, synthetic fused silica is as well the material of choice for optical components designed for DUV applications (wavelength range 160 nm - 260 nm). For higher light intensities, e.g. provided by Excimer lasers, UV photons may generate defect centers that effect the optical properties during usage, resulting in an aging of the optical components (UV radiation damage). Powerful Excimer lasers require optical materials that can withstand photon energy close to the band gap and the high intensity of the short pulse length. The UV transmission loss is restricted to the DUV wavelength range below 300 nm and

  10. Comparison of Phosphorous Absorption, Quality and Yield Between High Oil Corn and Common Corn as Influenced by Phosphorous Application

    Institute of Scientific and Technical Information of China (English)

    HE Ping; JIN Ji-yun; LI Wen-juan; LIU Hai-long; HUANG Shao-wen; WANG Xiu-fang; WANG Li-chun; XIE Jia-gui

    2005-01-01

    A field trial was carried out to investigate phosphorous (P) absorption, grain quality and yield between high oil corn and common corn. The results indicated that high oil corn var. Tongyou 1 obtained lower highest P absorption rate (HAR) and later occurring date of HAR, in comparison with common corn var. Simi 25. The highest HAR and the earliest occurring date of HAR was obtained by the treatments of P45 and P75 in Tongyou 1 and Simi 25 separately; while the total amount of P accumulated by maize plant was achieved by P105 treatment in both varieties. P in grain relied mainly on root uptake at maturation that accounted for 85.7-96.8% and 79.3-84.3% for Tongyou 1 and Simi 25, respectively. Tongyou 1 contained more oil and protein contents, but less starch content with lower grain yield. P application at appropriate rate enhanced contents of protein and fatty acid, but the increment of starch content was neglectable.

  11. Determination of Trace Iron in High Purity Sodium Fluoride by Graphite Furnace Atomic Absorption Spectrometry

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A method is described for the direct determination of iron in high purity sodium fluoride using graphite furnace atomic absorption spectrometry. Interferences caused by the matrix are investigated. It is shown that the ashing temperature can be increased to 1 400°C and matrix interferences eliminated, the sensi tivity of iron increased in 1.27 fold by the addition of nickel nitrate. The method is applied to the determina tion of iron in sodium fluoride and satisfactory results are obtained.

  12. From boron carbide to glass: Absorption of an elongated high-speed projectile in brittle materials

    Science.gov (United States)

    Rumyantsev, B. V.

    2016-09-01

    Penetration into boron carbide of an elongated high-speed projectile in the form of a copper jet produced by an explosion of a cumulative charge is studied. The efficiency of absorption of a copper jet in different brittle materials for evaluating their protective ability is compared. Conditions for the absence of the influence of the lateral unloading wave on the penetration zone, which provide the minimum penetration depth, are determined.

  13. The Myth of a High Savings Rate

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    In an attempt to entice consumers to save less and spend more, China has focused on perfecting its social security system, reforming taxation and dividend-sharing proportion between the government and state-owned enterprises. Liu Yuhui, Director of the China Economy Appraisal and Rating Center at the Institute of Finance and Banking, the Chinese Academy of Social Sciences, offered his insights in an Economic Observer article. Edited excerpts follow

  14. The Combustion of HMX. [burning rate at high pressures

    Science.gov (United States)

    Boggs, T. L.; Price, C. F.; Atwood, A. I.; Zurn, D. E.; Eisel, J. L.

    1980-01-01

    The burn rate of HMX was measured at high pressures (p more than 1000 psi). The self deflagration rate of HMX was determined from 1 atmosphere to 50,000 psi. The burning rate shows no significant slope breaks.

  15. Optical Absorption and X—Ray DIffractionStudies of Sulfur Under High Pressure

    Institute of Scientific and Technical Information of China (English)

    陈良辰; 王莉君

    1999-01-01

    In situ high pressure optical absorption measurements of sulfur have been carried out by using DAC device with a TASCO V-550 UV-VIS spectrophotometer at pressures up to 41.6GPa.The curves of absorption edge vs pressure were obtained.in which there are two turning points at about 5 and 12GPa,corresponding to two changes of colour in the optical observation:one is from yellow to red and the other from red to black at 5-6\\5and 10-12GPa,respectively.The absorption edge reaches above 800nm when the pressure is increased to 23GPa.The sturcture and phase transitions have also been investigated by using in situ high pressure energy-dispersive x-ray diffraction with synchrotron radiation at pressures up to 33.7GPa.No structure phase transition occurs at 5-6GPa.but there is a new high-pressure phase,caused probably by the reorientation or ordering of S8.

  16. The effects of dust scattering on high-resolution X-ray absorption edge structure

    Science.gov (United States)

    Corrales, L.; García, J.; Wilms, J.; Baganoff, F.

    2016-06-01

    High energy studies of astrophysical dust complement observations of dusty interstellar gas at other wavelengths. With high resolution X-ray spectroscopy, dust scattering significantly enhances the total extinction optical depth and alters the shape of photoelectric absorption edges. This effect is modulated by the dust grain size distribution, spatial location along the line of sight, and the imaging resolution of the X-ray telescope. At soft energies, the spectrum of scattered light is likely to have significant features at the 0.3 keV (C-K), 0.5 keV (O-K), and 0.7 keV (Fe-L) photoelectric absorption edges. This direct probe of ISM dust grain elements will be important for (i) understanding the relative abundances of graphitic grains or PAHs versus silicates, and (ii) measuring the depletion of gas phase elements into solid form. We focus in particular on the Fe-L edge, fitting a template for the total extinction to the high resolution spectrum of three X-ray binaries from the Chandra archive: GX 9+9, XTE J1817-330, and Cyg X-1. We discuss ways in which spectroscopy with XMM can yield insight into dust obscured objects such as stars, binaries, AGN, and foreground quasar absorption line systems.

  17. Surface Texturing Investigated for a High Solar Absorptance Low Infrared Emittance Solar Collector

    Science.gov (United States)

    Jaworske, Donald A.

    2001-01-01

    The objective of this work was to design, build, and vacuum test a high solar absorptance, low infrared emittance solar collector for heat engine and thermal switching applications. Mini-satellites proposed by the Applied Physics Laboratory for operation in environments that are subject to radiation threat may utilize a heat engine for power and a thermal bus for thermal control. To achieve this goal, a surface having high solar absorptance and low infrared emittance is needed. At the NASA Glenn Research Center, one concept being pursued to achieve this goal is texturing high thermal conductivity graphite epoxy composites using a directed atomic oxygen beam and then coating the textured surface with a reflective metallic coating. Coupons were successfully textured, coated, and evaluated. A variety of texturing conditions were explored, and textures were documented by scanning electron microscopy. Copper, gold, silver, iridium, and aluminum coatings were applied, and the highest solar absorptance to infrared emittance ratio was found to be 1.3. A full-sized solar collector was manufactured with this ratio, and the amount of heat collected was observed using an Inconel calorimeter installed in a bench-top vacuum chamber equipped with a solar simulator. Results to date indicate good heat flow through the system, with 9 W of heat flow measured by the calorimeter.

  18. Influence of external flow rates on characteristic equations of absorption chillers; Einfluss variabler Volumenstroeme auf charakteristische Gleichungen fuer Absorptionskaelteanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Ziegler, Felix; Albers, Jan [Technische Univ. Berlin (Germany). Inst. fuer Energietechnik

    2009-04-15

    The method of characteristic equations can be used to describe the performance of absorption chillers in a wide rage of part load conditions as a linear function of a characteristic temperature difference ({delta}{delta}t). This temperature difference combines the external temperatures of hot, chilled and cooling water into one parameter. Normally the achieved part load characteristic is a linear function of {delta}{delta}t provided that the heat transfer coefficients and thus the external flow rates are constant. Nevertheless, this assumption is often not fullfilled under practical conditions. Therefore the classical method has been improved in order to account for variable temperature and flow conditions. Despite of some simplifications the results are in good accordance with measurements. (orig.)

  19. LIQUID ARGON CALORIMETER PERFORMANCE AT HIGH RATES

    CERN Document Server

    Kukhtin, V; The ATLAS collaboration

    2011-01-01

    The performance of the ATLAS liquid argon endcap and forward calorimeters has been projected at the planned high luminosity LHC option HL-LHC by exposing small calorimeter modules of the electromagnetic, hadronic, and forward calorimeters to high intensity proton beams at IHEP/Protvino accelerator. The results of HV current and of pulse shape analysis, and also the dependence of signal amplitude on beam intensity are presented.

  20. High-velocity Hα Absorption Events in B8 Ia - A2 Ia Supergiant Stars

    Science.gov (United States)

    Morrison, Nancy D.; Markova, N.; Rother, S. J.

    2009-12-01

    Late B- and early A-type supergiants are notorious for the time variability of their Hα line profiles, but the physical cause of the variations is poorly understood. Usually, the line is filled in by emission, and the blue absorption wing does not extend to the terminal wind speed, which is roughly defined by the blue edges of the ultraviolet resonance lines. On rare occasions, however, the blue wing of Hα goes strongly into absorption over a wide velocity range, from the photospheric velocity almost all the way to the terminal wind speed. This phenomenon was first described by Kaufer et al. (1996, A&A, 314, 599), who denoted it by the term, "High-Velocity Absorption Event." In this report, high-resolution spectra from Ritter Observatory will be combined with published spectra to examine the temporal recurrence behavior and strength distribution of high-velocity absorption events and their incidence as a function of stellar parameters for the available sample of stars. All B8- and A0-type, Ia-class, stars in the sample that have been sufficiently well observed, as well as one A2-type star, show the events. However, there is some evidence that hyperluminous stars (luminosity class Ia+) do not show the events. In one of the most extensively observed stars in the sample (Rigel, B8 Ia), there is no clear periodicity in the recurrence times of the events. In addition to the strong events discovered by Kaufer et al. (1996), there is a broad distribution of more frequent, weaker events. Ritter Observatory receives operating support from the National Science Foundation Program for Research and Education with Small Telescopes (PREST) award AST-0440784.

  1. High Reproduction Rate versus Sexual Fidelity

    OpenAIRE

    Sousa, A. O.; de Oliveira, S. Moss

    2000-01-01

    We introduce fidelity into the bit-string Penna model for biological ageing and study the advantage of this fidelity when it produces a higher survival probability of the offspring due to paternal care. We attribute a lower reproduction rate to the faithful males but a higher death probability to the offspring of non-faithful males that abandon the pups to mate other females. The fidelity is considered as a genetic trait which is transmitted to the male offspring (with or without error). We s...

  2. Zinc absorption from composite meals. I. The significance of whest extraction rate, zinc, calcium, and protein content in meals based on bread.

    Science.gov (United States)

    Sandström, B; Arvidsson, B; Cederblad, A; Björn-Rasmussen, E

    1980-04-01

    The absorption of zinc in man from composite meals based on bread was measured with a radionuclide technique using 65Zn and whole-body counting. Bread was made up from wheat flour of 100 and 72% extraction rate. A lower absolute amount of zinc was absorbed from the white bread compared to the absorption from the same amount of wholemeal bread. When the two types of bread were enriched with zinc chloride the absorption was higher from the white bread than from the wholemeal bread. Addition of calcium in the form of milk products improved the absorption of zinc from a meal with wholemeal bread. A significant positive correlation was found between zinc absorption and the protein content in meals containing milk, cheese, beef, and egg in various combinations with the wholemeal bread.

  3. Smoking Rates Still High in Some Racial Groups, CDC Reports

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_160256.html Smoking Rates Still High in Some Racial Groups, CDC ... lot of progress in getting Americans to stop smoking, some groups still have high smoking rates, a ...

  4. Starch with high amylose and low in vitro digestibility increases short-chain fatty acid absorption, reduces peak insulin secretion, and modulates incretin secretion in pigs.

    Science.gov (United States)

    Regmi, Prajwal R; van Kempen, Theo A T G; Matte, J Jacques; Zijlstra, Ruurd T

    2011-03-01

    Diets containing different starch types affect peripheral glucose and insulin responses. However, the role of starch chemistry in kinetics of nutrient absorption and insulin and incretin secretion is poorly understood. Four portal vein-catheterized pigs (35.0 ± 0.2 kg body weight) consumed 4 diets containing 70% purified starch [0-63.2% amylose content and 0.22 (slowly) to 1.06%/min (rapidly) maximum rate of in vitro digestion] for 7-d periods in a 4 × 4 Latin square. On d 7, blood was collected for 12 h postprandial with simultaneous blood flow measurement for determining the net portal appearance (NPA) of nutrients and hormones. The NPA of glucose, insulin, C-peptide, and glucose-dependent insulinotropic polypeptide (GIP) during 0-4 h postprandial were lower (P starch. The peak NPA of insulin occurred prior to that of glucose when pigs consumed diets containing rapidly digestible starch. The kinetics of insulin secretion had a linear positive relation with kinetics of NPA of glucose (R(2) = 0.50; P starch with high amylose and low in vitro digestibility decreases the kinetics of glucose absorption and insulin and GIP secretion and increases SCFA absorption and glucagon-like peptide-1 secretion. In conclusion, starch with high amylose content and a lower rate and extent of in vitro digestion decreased glucose absorption and insulin secretion and increased SCFA absorption.

  5. Rates of passage of digesta and water absorption along the larg intestines of sheep, cows and pigs.

    Science.gov (United States)

    Hecker, J F; Grovum, W L

    1975-04-01

    In 5 cows, the mean length of the large intestine was only slightly greater than that of 21 sheep and 3 pigs. At about one-fifth of the way along the large intestine of the sheep and cows, corresponding to the end of the proximal colon and start of the spiral colon, there were marked reductions in the amount of digesta present and in the lumen diameter. In pigs these parameters decreased gradually along the large intestine. In all parts of the large intestine, the cows had more water in the digesta than did the sheep or the pigs. Nevertheless, the decrease in water content between the caecum and the rectum was similar for the cows and the sheep but less in the pigs. The rate of passage of digesta increased gradually along the large intestine of the pigs, but in the cows and sheep the rate was least in the caecum and proximal colon and greatest in the spiral colon. The total retention time for digesta in the large intestine was approximately 30, 20, and 9 h in the pigs, sheep, and cows respectively. The rate of water absorption from the large intestine was most rapid in the cows and slowest in the pigs. Differences in faecal water content between the species were not due to differences in retention times in the large intestine.

  6. Effects of High Hydrostatic Pressure on Water Absorption of Adzuki Beans

    Directory of Open Access Journals (Sweden)

    Shigeaki Ueno

    2015-05-01

    Full Text Available The effect of high hydrostatic pressure (HHP treatment on dried soybean, adzuki bean, and kintoki kidney bean, which are low-moisture-content cellular biological materials, was investigated from the viewpoint of water absorption. The samples were vacuum-packed with distilled water and pressurized at 200 MPa and 25 °C for 10 min. After the HHP treatment, time courses of the moisture contents of the samples were measured, and the dimensionless moisture contents were estimated. Water absorption in the case of soybean could be fitted well by a simple water diffusion model. High pressures were found to have negligible effects on water absorption into the cotyledon of soybean and kintoki kidney bean. A non-linear least square method based on the Weibull equation was applied for the adzuki beans, and the effective water diffusion coefficient was found to increase significantly from 8.6 × 10−13 to 6.7 × 10−10 m2/s after HHP treatment. Approximately 30% of the testa of the adzuki bean was damaged upon HHP treatment, which was comparable to the surface area of the testa in the partially peeled adzuki bean sample. Thus, HHP was confirmed to promote mass transfer to the cotyledon of legumes with a tight testa.

  7. Subaru high resolution spectroscopy of complex metal absorption lines of QSO HS1603+3820

    CERN Document Server

    Misawa, T; Takada-Hidai, M; Wang, Y; Kashikawa, N; Iye, M; Tanaka, I; Misawa, Toru; Yamada, Toru; Takada-Hidai, Masahide; Wang, Yiping; Kashikawa, Nobunari; Iye, Masanori; Tanaka, Ichi

    2002-01-01

    We present a high resolution spectrum of the quasar, HS1603+3820 (z_em=2.542), observed with the High Dispersion Spectrograph (HDS) on Subaru Telescope. This quasar, first discovered in the Hamburg/CfA Quasar Survey, has 11 C IV lines at 1.96 2.29 and resolves some of them into multiple narrow components with b 65 km/s). We use three properties of C IV lines, specifically, time variability, covering factor, and absorption line profile, to classify them into quasar intrinsic absorption lines (QIALs) and spatially intervening absorption lines (SIALs). The C IV lines at 2.42 < z_abs < 2.45 are classified as QIALs in spite of their large velocity shifts from the quasar. Perhaps they are produced by gas clouds ejected from the quasar with the velocity of v_ej = 8000 km/s -- 10000 km/s. On the other hand, three C IV lines at 2.48 < z_abs < 2.55 are classified as SIALs, which suggests there exist intervening absorbers near the quasar. We, however, cannot rule out QIALs for the two lines at z_abs ~ 2.54...

  8. High affinity binding site-mediated prevention of chemical absorption across the gastrointestinal tract.

    Science.gov (United States)

    Rasmussen, M V; Barker, T T; Silbart, L K

    2001-12-15

    Preventing mucosal absorption of low-molecular weight compounds such as carcinogens, toxins and drugs could help prevent many diseases. To characterize the effects of dose and timing on high-affinity binding site mediated sequestration of specific chemical ligands in the gastrointestinal tract, avidin was perorally-administered to mice either prior to or mixed with 3H-biotin. Avidin enhanced fecal 3H-biotin excretion in a dose-dependent manner, consistent with the accepted mechanism of egg white-induced biotin deficiency syndrome. Avidin administration up to 4 h before 3H-biotin administration also enhanced fecal 3H-biotin excretion. Activated charcoal (AC) reduced 3H-biotin absorption when mixed with 3H-biotin before ingestion, but was ineffective when ingested prior to 3H-biotin. These studies suggest that ingestion of high-affinity protein binding sites can establish an absorptive barrier at the gastrointestinal mucosa to prevent the uptake of unwanted low molecular-weight chemicals.

  9. High sensitivity of Indian summer monsoon to Middle East dust absorptive properties

    Science.gov (United States)

    Jin, Qinjian; Yang, Zong-Liang; Wei, Jiangfeng

    2016-07-01

    The absorptive properties of dust aerosols largely determine the magnitude of their radiative impacts on the climate system. Currently, climate models use globally constant values of dust imaginary refractive index (IRI), a parameter describing the dust absorption efficiency of solar radiation, although it is highly variable. Here we show with model experiments that the dust-induced Indian summer monsoon (ISM) rainfall differences (with dust minus without dust) change from -9% to 23% of long-term climatology as the dust IRI is changed from zero to the highest values used in the current literature. A comparison of the model results with surface observations, satellite retrievals, and reanalysis data sets indicates that the dust IRI values used in most current climate models are too low, tending to significantly underestimate dust radiative impacts on the ISM system. This study highlights the necessity for developing a parameterization of dust IRI for climate studies.

  10. Influence of osmotic distillation on membrane absorption for the treatment of high strength ammonia wastewater

    Institute of Scientific and Technical Information of China (English)

    WANG Guan-ping; SHI Han-chang; SHEN Zhi-song

    2004-01-01

    Osmotic distillation(OD) was found to be a coupled process in membrane absorption(MA) for the treatment of high strength ammonia wastewater. As a result, ammonia could not be concentrated in absorption solution(AS) as expected. The inhibition of the coupled OD in MA process was investigated as well as various factors affecting the inhibition. The results indicated that the coupled OD can be effectively inhibited by heating concentrated solution and cooling dilute solution. It was also found that experimental minimum inhibition temperature difference(MITD) between concentrated and dilute solutions was different when using polyvinylidene fluoride(PVDF)and polypropylene(PP) membranes respectively, which could be ascribed to material properties, such as OD and membrane distillation (MD) coefficients of the membranes. Experimental MITDs were found to be higher than theoretical MITDs which were calculated using a simplified method.

  11. Effects of Noise and Absorption on High Frequency Measurements of Acoustic-Backscatter from Fish

    Directory of Open Access Journals (Sweden)

    Masahiko Furusawa

    2015-01-01

    Full Text Available Quantitative echosounders operating at multiple frequencies (e.g., 18, 38, 70, 120, 200, 333, and 710 kHz are often used to observe fish and zooplankton and identify their species. At frequencies above 100 kHz, the absorption attenuation increases rapidly and decreases the signal-to-noise ratio (SNR. Also, incomplete compensation for the attenuation may result in measurement error. This paper addresses the effects of the attenuation and noise on high frequency measurements of acoustic backscatter from fish. It is shown that measurements of a fish with target strength of −40 dB at 200 m depth are limited by SNR to frequencies up to about 100 kHz. Above 100 kHz, absorption coefficients must be matched to local environmental conditions.

  12. Surface acoustic admittance and absorption of highly porous, layered, fibrous materials

    Science.gov (United States)

    Tesar, J. S.; Lambert, R. F.

    1984-01-01

    Some acoustic properties of Kevlar-29 - a fine fibered, layered material is investigated. Kevlar is characterized by very high strength, uniform filaments arranged in a parallel batt where most filaments are random in the x-y plane but ordered as planes in the z direction. For experimental purposes, volume porosity, static flow resistance and mean filament diameter are used to identify the material. To determine the acoustic surface admittance of Kevlar, batts of the material are cut into small pads and placed into a standing wave tube terminated by a rigid brass plug. The attenuation and relative phase shift are recorded at each frequency in the range of 50 to 6000 Hz. Normalized conductance and susceptance are combined to form the acoustic absorption coefficient. The data are compared with theory by plotting the normalized admittance and normal incident absorption coefficient versus cyclic frequency.

  13. Highly Ionized Absorption in the X-ray Spectrum of Cyg X-1

    CERN Document Server

    Marshall, H L; Fang, T; Cui, W; Canizares, C R; Miller, J M; Lewin, W H G

    2001-01-01

    Using the Chandra High Energy Transmission Grating Spectrometer (HETGS), we have found significant absorption features in the X-ray spectrum of Cyg X-1 taken in the continuous clocking mode. These features include resonance lines of He-like ions of S, Si, and Mg; the Ly alpha lines of H-like S, Si, Mg, and Ne; and several lower ionization lines of Fe XX, XXII, and XXIV. Preliminary analysis shows that the lines are resolved in many cases, giving line widths of order 300 km/s and are redshifted by 460 +/- 10 km/s. These features are interpreted in the context of an accreting stellar wind model that is ionized by the X-ray source. In addition, there are clear absorption features due to neutral Mg, Fe, and O in the interstellar medium.

  14. High frame rate imaging based photometry

    DEFF Research Database (Denmark)

    Harpsøe, Kennet Bomann West; Jørgensen, U. G.; Andersen, M. I.;

    2012-01-01

    in conventional CCDs, and new methods for handling these must be developed. We aim to investigate how the normal photometric reduction steps from conventional CCDs should be adjusted to be applicable to EMCCD data. One complication is that a bias frame cannot be obtained conventionally, as the output from...... an EMCCD is not normally distributed. Also, the readout process generates spurious charges in any CCD, but in EMCCD data, these charges are visible as opposed to the conventional CCD. Furthermore we aim to eliminate the photon waste associated with lucky imaging by combining this method with shift......-and-add. A simple probabilistic model for the dark output of an EMCCD is developed. Fitting this model with the expectation-maximization algorithm allows us to estimate the bias, readout noise, amplification, and spurious charge rate per pixel and thus correct for these phenomena. To investigate the stability...

  15. Size and rate effects on mechanical behavior of ultra high performance concrete

    Science.gov (United States)

    Lim, Boon Him

    Cor-Tuf, broadly characterize as a reactive powder concrete is a type of cementitious material. Cementitious materials have been observed to exhibit a strain-rate dependent mechanical behavior. The mechanical behavior of cementitious materials can also depend significantly on specimen sizes. Therefore it is crucial to determine the behavior of Cor-Tuf with different specimen sizes for high-rate applications. For this purpose, split Hopkinson pressure bar (SHPB), also known as Kolsky bar was utilized to determine the dynamic behavior of Cor-Tuf for different specimen sizes under uniaxial dynamic compression loading at different strain rates. It was observed that as strain rate increases the compressive strength decreases for the small specimen. However for specimens at larger diameter, the compressive strength was observed to be rate independent. The Young's modulus decreases as strain rate increases for all specimen sizes. However the critical strain and energy absorption per unit volume was observed to increase as the strain rate increases.

  16. VUV-absorption cross section of CO2 at high temperatures and impact on exoplanet atmospheres

    Directory of Open Access Journals (Sweden)

    Venot Olivia

    2014-02-01

    Full Text Available Ultraviolet (UV absorption cross sections are an essential ingredient of photochemical atmosphere models. Exoplanet searches have unveiled a large population of short-period objects with hot atmospheres, very different from what we find in our solar system. Transiting exoplanets whose atmospheres can now be studied by transit spectroscopy receive extremely strong UV fluxes and have typical temperatures ranging from 400 to 2500 K. At these temperatures, UV photolysis cross section data are severely lacking. Our goal is to provide high-temperature absorption cross sections and their temperature dependency for important atmospheric compounds. This study is dedicated to CO2, which is observed and photodissociated in exoplanet atmospheres. We performed these measurements for the 115 - 200 nm range at 300, 410, 480, and 550 K. In the 195 - 230 nm range, we worked at seven temperatures between 465 and 800 K. We found that the absorption cross section of CO2 is very sensitive to temperature, especially above 160 nm. Within the studied range of temperature, the CO2 cross section can vary by more than two orders of magnitude. This, in particular, makes the absorption of CO2 significant up to wavelengths as high as 230 nm, while it is negligible above 200 nm at 300 K. To investigate the influence of these new data on the photochemistry of exoplanets, we implemented the measured cross section into a 1D photochemical model. The model predicts that accounting for this temperature dependency of CO2 cross section can affect the computed abundances of NH3, CO2, and CO by one order of magnitude in the atmospheres of hot Jupiter and hot Neptune.

  17. High pressure, high strain rate material strength studies

    Science.gov (United States)

    Remington, B. A.; Arsenlis, A.; Barton, N.; Belof, J.; Cavallo, R.; Maddox, B.; Park, H.-S.; Prisbrey, S.; Rudd, R.; Comley, A.; Meyers, M.; Wark, J.

    2011-10-01

    Constitutive models for material strength are currently being tested at high pressures by comparing 2D simulations with experiments measuring the Rayleigh-Taylor (RT) instability evolution in solid-state samples of vanadium (V), tantalum (Ta), and iron (Fe). The multiscale strength models being tested combine molecular dynamics, dislocation dynamics, and continuum simulations. Our analysis for the V experiments suggests that the material deformation at these conditions falls into the phonon drag regime, whereas for Ta, the deformation resides mainly in the thermal activation regime. Recent Fe-RT experiments suggest perturbation growth about the alpha-epsilon (bcc-hcp) phase transition threshold has been observed. Using the LLNL multiscale models, we decompose the strength as a function of strain rate into its dominant components of thermal activation, phonon drag, and work hardening. We have also developed a dynamic diffraction diagnostic technique to measure strength directly from shock compressed single crystal samples. Finally, recovery experiments allow a comparison of residual dislocation density with predictions from the multiscale model. This work performed under the auspices of the U.S. DoE by LLNL Security, LLC under Contract DE-AC52-07NA27344.

  18. High-Rate Capable Floating Strip Micromegas

    CERN Document Server

    Bortfeldt, Jonathan; Biebel, Otmar; Danger, Helge; Flierl, Bernhard; Hertenberger, Ralf; Lösel, Philipp; Moll, Samuel; Parodi, Katia; Rinaldi, Ilaria; Ruschke, Alexander; Zibell, André

    2015-01-01

    We report on the optimization of discharge insensitive floating strip Micromegas (MICRO-MEsh GASeous) detectors, fit for use in high-energy muon spectrometers. The suitability of these detectors for particle tracking is shown in high-background environments and at very high particle fluxes up to 60MHz/cm$^2$. Measurement and simulation of the microscopic discharge behavior have demonstrated the excellent discharge tolerance. A floating strip Micromegas with an active area of 48cm$\\times$50cm with 1920 copper anode strips exhibits in 120GeV pion beams a spatial resolution of 50$\\mu$m at detection efficiencies above 95%. Pulse height, spatial resolution and detection efficiency are homogeneous over the detector. Reconstruction of particle track inclination in a single detector plane is discussed, optimum angular resolutions below $5^\\circ$ are observed. Systematic deviations of this $\\mu$TPC-method are fully understood. The reconstruction capabilities for minimum ionizing muons are investigated in a 6.4cm$\\time...

  19. High sensitivity probe absorption technique for time-of-flight measurements on cold atoms

    Indian Academy of Sciences (India)

    A K Mohapatra; C S Unnikrishnan

    2006-06-01

    We report on a phase-sensitive probe absorption technique with high sensitivity, capable of detecting a few hundred ultra-cold atoms in flight in an observation time of a few milliseconds. The large signal-to-noise ratio achieved is sufficient for reliable measurements on low intensity beams of cold atoms. We demonstrate the high sensitivity and figure of merit of the simple method by measuring the time-of-flight of atoms moving upwards from a magneto-optical trap released in the gravitational field.

  20. High dose rate brachytherapy source measurement intercomparison.

    Science.gov (United States)

    Poder, Joel; Smith, Ryan L; Shelton, Nikki; Whitaker, May; Butler, Duncan; Haworth, Annette

    2017-06-01

    This work presents a comparison of air kerma rate (AKR) measurements performed by multiple radiotherapy centres for a single HDR (192)Ir source. Two separate groups (consisting of 15 centres) performed AKR measurements at one of two host centres in Australia. Each group travelled to one of the host centres and measured the AKR of a single (192)Ir source using their own equipment and local protocols. Results were compared to the (192)Ir source calibration certificate provided by the manufacturer by means of a ratio of measured to certified AKR. The comparisons showed remarkably consistent results with the maximum deviation in measurement from the decay-corrected source certificate value being 1.1%. The maximum percentage difference between any two measurements was less than 2%. The comparisons demonstrated the consistency of well-chambers used for (192)Ir AKR measurements in Australia, despite the lack of a local calibration service, and served as a valuable focal point for the exchange of ideas and dosimetry methods.

  1. The CO2 absorption spectrum in the 2.3 μm transparency window by high sensitivity CRDS: (II) Self-absorption continuum

    Science.gov (United States)

    Mondelain, D.; Vasilchenko, S.; Čermák, P.; Kassi, S.; Campargue, A.

    2017-01-01

    The CO2 absorption continuum near 2.3 μm is determined for a series of sub atmospheric pressures (250-750 Torr) by high sensitivity Cavity Ring Down Spectroscopy. An experimental procedure consisting in injecting successively a gas flow of CO2 and synthetic air, keeping constant the gas pressure in the CRDS cell, has been developed. This procedure insures a high stability of the spectra baseline by avoiding changes of the optical alignment due to pressure changes. The CO2 continuum was obtained as the difference between the CO2 absorption coefficient and a local lines simulation using a Voigt profile truncated at ±25 cm-1. Following the results of the preceding analysis of the CO2 rovibrational lines (Vasilchenko S et al. J Quant Spectrosc Radiat Transfer 10.1016/j.jqsrt.2016.07.002, a CO2 line list with intensities obtained by variational calculations and empirical line positions was preferred to the HITRAN line list. A quadratic pressure dependence of the absorption continuum is observed, with an average binary absorption coefficient increasing from 2 to 4×10-8 cm-1 amagat-2 between 4320 and 4380 cm-1. The obtained continuum is found in good agreement with a previous measurement using much higher densities (20 amagat) and a low resolution grating spectrograph and is consistent with values currently used in the analysis of Venus spectra.

  2. In Situ Density Measurement of Basaltic Melts at High Pressure by X-ray Absorption Method

    Science.gov (United States)

    Ando, R.; Ohtani, E.; Suzuki, A.; Urakawa, S.; Katayama, Y.

    2004-12-01

    Density of silicate melt at high pressure is one of the most important properties to understand magma migration in the planetary interior. However, because of experimental difficulties, the density of magma at high pressure is poorly known. Katayama et al. (1996) recently developed a new in situ density measurement method for metallic melts, based on the density dependency of X-ray absorption in the sample. In this study, we tried to measure the density of basaltic melt by this absorption method. When X-ray is transmitted to the sample, the intensity of the transmitted X-ray beam (I) is expressed as follows; I=I0exp(-μ ρ t), where I0 is the intensity of incident X-ray beam, μ is the mass absorption coefficient, ρ is the density of the sample, and t is the thickness of the sample. If t and μ are known, we can determine the density of the sample by measuring I and I0. This is the principle of the absorption method for density measurement. In this study, in order to determine t, we used a single crystalline diamond cylinder as a sample capsule, diamond is less compressive and less deformable so that even at high pressure t (thickness of the sample at the point x) is expressed as follows; t = 2*(R02-x2)1/2, R0 is the inner radius of cylinder at the ambient condition, and x is distance from a center of the capsule. And diamond also shows less absorption so that this make it possible to measure the density of silicate melt with smaller absorption coefficient than metallic melts. In order to know the μ of the sample, we measured both densities (ρ ) and absorptions (I/I0) for some glasses and crystals with same composition of the sample at the ambient condition, and calculated as fallows; μ =ln(I/I0)/ρ . Experiments were made at the beamline (BL22XU) of SPring-8. For generation of high pressure and high temperature, we used DIA-type cubic anvil apparatus (SMAP180) there. We used tungsten carbide anvils with the edge-length of 6 mm. The energy of monochromatic X

  3. Liquid argon calorimeter performance at high rates

    CERN Document Server

    Seifert, F; The ATLAS collaboration

    2012-01-01

    The expected increase of luminosity at HL-LHC by a factor of ten with respect to LHC luminosities has serious consequences for the signal reconstruction, radiation hardness requirements and operations of the ATLAS liquid argon calorimeters in the endcap, respectively forward region. Small modules of each type of calorimeter have been built and exposed to a high intensity proton beam of 50 GeV at IHEP/Protvino. The beam is extracted via the bent crystal technique, offering the unique opportunity to cover intensities ranging from $10^6$ p/s up to $10^{12}$ p/s. This exceeds the deposited energy per time expected at HL-LHC by more than a factor of 100. The correlation between beam intensity and the read-out signal has been studied. The data show clear indications of pulse shape distortion due to the high ionization build-up, in agreement with MC expectations. This is also confirmed from the dependence of the HV currents on beam intensity.

  4. Liquid Argon Calorimeter performance at High Rates

    CERN Document Server

    Seifert, F; The ATLAS collaboration

    2013-01-01

    The expected increase of luminosity at HL-LHC by a factor of ten with respect to LHC luminosities has serious consequences for the signal reconstruction, radiation hardness requirements and operations of the ATLAS liquid argon calorimeters in the endcap, respectively forward region. Small modules of each type of calorimeter have been built and exposed to a high intensity proton beam of 50 GeV at IHEP/Protvino. The beam is extracted via the bent crystal technique, offering the unique opportunity to cover intensities ranging from $10^6$ p/s up to $3\\cdot10^{11}$ p/s. This exceeds the deposited energy per time expected at HL-LHC by more than a factor of 100. The correlation between beam intensity and the read-out signal has been studied. The data show clear indications of pulse shape distortion due to the high ionization build-up, in agreement with MC expectations. This is also confirmed from the dependence of the HV currents on beam intensity.

  5. High-deposition-rate ceramics synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Allendorf, M.D.; Osterheld, T.H.; Outka, D.A. [Sandia National Laboratories, Livermore, CA (United States)] [and others

    1995-05-01

    Parallel experimental and computational investigations are conducted in this project to develop validated numerical models of ceramic synthesis processes. Experiments are conducted in the High-Temperature Materials Synthesis Laboratory in Sandia`s Combustion Research Facility. A high-temperature flow reactor that can accommodate small preforms (1-3 cm diameter) generates conditions under which deposition can be observed, with flexibility to vary both deposition temperature (up to 1500 K) and pressure (as low as 10 torr). Both mass spectrometric and laser diagnostic probes are available to provide measurements of gas-phase compositions. Experiments using surface analytical techniques are also applied to characterize important processes occuring on the deposit surface. Computational tools developed through extensive research in the combustion field are employed to simulate the chemically reacting flows present in typical industrial reactors. These include the CHEMKIN and Surface-CHEMKIN suites of codes, which permit facile development of complex reaction mechanisms and vastly simplify the implementation of multi-component transport and thermodynamics. Quantum chemistry codes are also used to estimate thermodynamic and kinetic data for species and reactions for which this information is unavailable.

  6. Correlation between relative growth rate and specific leaf area requires associations of specific leaf area with nitrogen absorption rate of roots.

    Science.gov (United States)

    Osone, Yoko; Ishida, Atsushi; Tateno, Masaki

    2008-07-01

    Close correlations between specific leaf area (SLA) and relative growth rate (RGR) have been reported in many studies. However, theoretically, SLA by itself has small net positive effect on RGR because any increase in SLA inevitably causes a decrease in area-based leaf nitrogen concentration (LNCa), another RGR component. It was hypothesized that, for a correlation between SLA and RGR, SLA needs to be associated with specific nitrogen absorption rate of roots (SAR), which counteracts the negative effect of SLA on LNCa. Five trees and six herbs were grown under optimal conditions and relationships between SAR and RGR components were analyzed using a model based on balanced growth hypothesis. SLA varied 1.9-fold between species. Simulations predicted that, if SAR is not associated with SLA, this variation in SLA would cause a47% decrease in LNCa along the SLA gradient, leading to a marginal net positive effect on RGR. In reality, SAR was positively related to SLA, showing a 3.9-fold variation, which largely compensated for the negative effect of SLA on LNCa. Consequently, LNCa values were almost constant across species and a positive SLA-RGR relationship was achieved. These results highlight the importance of leaf-root interactions in understanding interspecific differences in RGR.

  7. High rate fabrication of compression molded components

    Energy Technology Data Exchange (ETDEWEB)

    Matsen, Marc R.; Negley, Mark A.; Dykstra, William C.; Smith, Glen L.; Miller, Robert J.

    2016-04-19

    A method for fabricating a thermoplastic composite component comprises inductively heating a thermoplastic pre-form with a first induction coil by inducing current to flow in susceptor wires disposed throughout the pre-form, inductively heating smart susceptors in a molding tool to a leveling temperature with a second induction coil by applying a high-strength magnetic field having a magnetic flux that passes through surfaces of the smart susceptors, shaping the magnetic flux that passes through surfaces of the smart susceptors to flow substantially parallel to a molding surface of the smart susceptors, placing the heated pre-form between the heated smart susceptors; and applying molding pressure to the pre-form to form the composite component.

  8. The modern high rate digital cassette recorder

    Science.gov (United States)

    Clemow, Martin

    1993-01-01

    The magnetic tape recorder has played an essential role in the capture and storage of instrumentation data for more than thirty years. During this time, data recording technology has steadily progressed to meet user demands for more channels, wider bandwidths, and longer recording durations. When acquisition and processing moved from analog to digital techniques, so recorder design followed suit. Milestones marking the evolution of the data recorder through these various stages - multi-track analog, high density longitudinal digital, and more recently rotary digital - have often represented important breakthroughs in the handling of ever-greater quantities of data. Throughout this period there has been a very clear line of demarcation between data storage methods in the 'instrumentation world' on the one hand and the 'computer peripheral world' on the other. This is despite the fact that instrumentation data, whether analog or digital at the point of acquisition, is now likely to be processed on a digital computer at some stage. Regardless of whether the processing device is a small personal computer, a workstation, or the largest supercomputer, system integrators have traditionally been faced with the same basic problem - how to interface what is essentially a manually controlled, continuously running device (the tape recorder) into the fast start/stop computer environment without resorting to an excessive amount of complex custom interfacing and performance compromise. The increasing availability of affordable high power processing equipment throughout the scientific world is forcing recorder manufacturers to make their latest and perhaps most important breakthrough - the computer-friendly data recorder. The operating characteristics of such recorders are discussed and the resultant impact on both data acquisition and data analysis elements of system configuration are considered.

  9. Correlation between disintegration, dissolution and in vivo absorption rate in the case of compounds with benzyl-isoquinoline structures and its pharmacokinetic aspects.

    Science.gov (United States)

    Marton, S; Szentmiklósi, P; Rácz, I

    1984-01-01

    Investigations have proved that in the case of po preparations disintegration time, dissolution rate and in vivo absorption rate are closely interrelated. These correlations described by adequate mathematical formulas are valid in the case of papaverine, drotaverine and Depogen--compounds with benzyl-isoquinoline structure.

  10. SOFIA/EXES Observations of Water Absorption in the Protostar AFGL 2591 at High Spectral Resolution

    CERN Document Server

    Indriolo, Nick; DeWitt, C N; Richter, M J; Boogert, A C A; Harper, G M; Jaffe, D T; Kulas, K R; McKelvey, M E; Ryde, N; Vacca, W

    2015-01-01

    We present high spectral resolution (~3 km/s) observations of the nu_2 ro-vibrational band of H2O in the 6.086--6.135 micron range toward the massive protostar AFGL 2591 using the Echelon-Cross-Echelle Spectrograph (EXES) on the Stratospheric Observatory for Infrared Astronomy (SOFIA). Ten absorption features are detected in total, with seven caused by transitions in the nu_2 band of H2O, two by transitions in the first vibrationally excited nu_2 band of H2O, and one by a transition in the nu_2 band of H2{18}O. Among the detected transitions is the nu_2 1(1,1)--0(0,0) line which probes the lowest lying rotational level of para-H2O. The stronger transitions appear to be optically thick, but reach maximum absorption at a depth of about 25%, suggesting that the background source is only partially covered by the absorbing gas, or that the absorption arises within the 6 micron emitting photosphere. Assuming a covering fraction of 25%, the H2O column density and rotational temperature that best fit the observed abs...

  11. High-resolution Absorption Spectra of Acetylene in 142.8-152.3 nm

    Institute of Scientific and Technical Information of China (English)

    Ya-hua Hu; Chen Zhen; Jing-hua Dai; Xiao-guo Zhou; Shi-lin Liu

    2008-01-01

    The absorption spectra of acetylene molecules was measured under jet-cooled conditions in the wavelength range of 142.8-152.3 nm, with a tunable and highly resolved vacuum ultraviolet (VUV) laser generated by two-photon resonant four wave difference frequency mixing processes. Due to the sufficient vibrational and rotational cooling effect of the molecular beam and the higher resolution VUV laser, the observed absorption spectra exhibit more distinct spectral features than the previous works measured at room temperature. The major three vibrational bands are assigned as a C-C symmetry stretching vibrational progress (v2=0-2) of the C~Ⅱu state of acetylene. The observed shoulder peak at 148.2 nm is assigned to the first overtone band of the trans-bending mode v4 of the C~Ⅱu state of acetylene. Additionally, the two components, 42 (μ1 Ⅱu) and 42(K1Ⅱu), are suggested to exhibit in the present absorption spectra, due to their Penner-Teller effect and transition selection rule. All band origins and bandwidths are obtained subsequently, and it is found that bandwidths are broadened and lifetimes decrease gradually with the excitation of vibration.

  12. High-resolution Absorption Spectra of Acetylene in 142.8-152.3 nm

    Science.gov (United States)

    Hu, Ya-hua; Zhen, Chen; Dai, Jing-hua; Zhou, Xiao-guo; Liu, Shi-lin

    2008-10-01

    The absorption spectra of acetylene molecules was measured under jet-cooled conditions in the wavelength range of 142.8-152.3 nm, with a tunable and highly resolved vacuum ultraviolet (VUV) laser generated by two-photon resonant four wave difference frequency mixing processes. Due to the sufficient vibrational and rotational cooling effect of the molecular beam and the higher resolution VUV laser, the observed absorption spectra exhibit more distinct spectral features than the previous works measured at room temperature. The major three vibrational bands are assigned as a C-C symmetry stretching vibrational progress (u2 = 0-2) of the tilde C1 IIu state of acetylene. The observed shoulder peak at 148.2 nm is assigned to the first overtone band of the trans-bending mode u4 of the tilde C1 IIustate of acetylene. Additionally, the two components, 4o2(μ1IIu) and 4o2(κ1 IIuare suggested to exhibit in the present absorption spectra, due to their Renner-Teller effect and transition selection rule. All band origins and bandwidths are obtained subsequently, and it is found that bandwidths are broadened and lifetimes decrease gradually with the excitation of vibration.

  13. Highly luminescent S, N co-doped graphene quantum dots with broad visible absorption bands for visible light photocatalysts

    Science.gov (United States)

    Qu, Dan; Zheng, Min; Du, Peng; Zhou, Yue; Zhang, Ligong; Li, Di; Tan, Huaqiao; Zhao, Zhao; Xie, Zhigang; Sun, Zaicheng

    2013-11-01

    A facile hydrothermal synthesis route to N and S, N co-doped graphene quantum dots (GQDs) was developed by using citric acid as the C source and urea or thiourea as N and S sources. Both N and S, N doped GQDs showed high quantum yield (78% and 71%), excitation independent under excitation of 340-400 nm and single exponential decay under UV excitation. A broad absorption band in the visible region appeared in S, N co-doped GQDs due to doping with sulfur, which alters the surface state of GQDs. However, S, N co-doped GQDs show different color emission under excitation of 420-520 nm due to their absorption in the visible region. The excellent photocatalytic performance of the S, N co-doped GQD/TiO2 composites was demonstrated by degradation of rhodamine B under visible light. The apparent rate of S, N:GQD/TiO2 is 3 and 10 times higher than that of N:GQD/TiO2 and P25 TiO2 under visible light irradiation, respectively.A facile hydrothermal synthesis route to N and S, N co-doped graphene quantum dots (GQDs) was developed by using citric acid as the C source and urea or thiourea as N and S sources. Both N and S, N doped GQDs showed high quantum yield (78% and 71%), excitation independent under excitation of 340-400 nm and single exponential decay under UV excitation. A broad absorption band in the visible region appeared in S, N co-doped GQDs due to doping with sulfur, which alters the surface state of GQDs. However, S, N co-doped GQDs show different color emission under excitation of 420-520 nm due to their absorption in the visible region. The excellent photocatalytic performance of the S, N co-doped GQD/TiO2 composites was demonstrated by degradation of rhodamine B under visible light. The apparent rate of S, N:GQD/TiO2 is 3 and 10 times higher than that of N:GQD/TiO2 and P25 TiO2 under visible light irradiation, respectively. Electronic supplementary information (ESI) available: More XPS and UV-Vis spectra. See DOI: 10.1039/c3nr04402e

  14. Influence of substrate heating on excited state generation rates and lifetime in organic solar cells studied by photoinduced absorption spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Ziehlke, Hannah; Koerner, Christian; Leo, Karl; Riede, Moritz [IAPP, TU Dresden (Germany); Fitzner, Roland; Reinold, Egon; Baeuerle, Peter [Institut fuer Organische Chemie II und Neue Materialien, Univ. Ulm (Germany)

    2011-07-01

    The performance of organic solar cells crucially depends on the separation of photogenerated excitons into free charge carriers. The dissociation process is sensitively influenced by the nanomorphology of donor (D) and acceptor (A) phases in the photoactive blend layer. Closed percolation paths have to be present such that the created charges are able to leave the blend layer, but also the crystallinity of the D- and the A-phase influence exciton dissociation on a molecular scale. Substrate heating during the vacuum deposition of the active layer is a method to influence the thin film morphology that can lead to improved device performance. We here characterize dicyanovinyl capped quinquethiophenes (D) deposited on substrates at different temperatures (30 and 80 C). Photoinduced absorption spectroscopy (PIA) is used to determine excited state lifetimes and generation rates.We find that efficient charge separation occurs in blends with C{sub 60} (A) and identify the observed excited states as donor cations and triplet excitons. Heating the substrate results in an increased lifetime of the donor cation on the one hand and a decrease in the generation rate of cations on the other hand. The PIA results are complemented by solar cell devices as well as morphological studies.

  15. Determination of phosphorus using high-resolution diphosphorus molecular absorption spectra produced in the graphite furnace

    Science.gov (United States)

    Huang, Mao Dong; Becker-Ross, Helmut; Okruss, Michael; Geisler, Sebastian; Florek, Stefan

    2016-01-01

    Molecular absorption of diphosphorus was produced in a graphite furnace and evaluated in view of its suitability for phosphorus determination. Measurements were performed with two different high-resolution continuum source absorption spectrometers. The first system is a newly in-house developed simultaneous broad-range spectrograph, which was mainly used for recording overview absorption spectra of P2 between 193 nm and 245 nm. The region covers the main part of the C 1Σu+ ← X 1Σg+ electronic transition and shows a complex structure with many vibrational bands, each consisting of a multitude of sharp rotational lines. With the help of molecular data available for P2, an assignment of the vibrational bands was possible and the rotational structure could be compared with simulated spectra. The second system is a commercial sequential continuum source spectrometer, which was used for the basic analytical measurements. The P2 rotational line at 204.205 nm was selected and systematically evaluated with regard to phosphorus determination. The conditions for P2 generation were optimized and it was found that the combination of a ZrC modified graphite tube and borate as a chemical modifier were essential for a good production of P2. Serious interferences were found in the case of nitrate and sulfuric acid, although the nitrate interference can be eliminated by a higher pyrolysis temperature. The reliability of the method was proved by analysis of certified samples. Using standard tubes, a characteristic mass of 10 ng and a limit of detection of 7 ng were found. The values could further be improved by a factor of ten using a miniaturized tube with an internal diameter of 2 mm. Compared to the conventional method based on the phosphorus absorption line at 213.618 nm, the advantages of using P2 are the gentle temperature conditions and the potential of performing a simultaneous multi-line evaluation to further improve the limit of detection.

  16. High data rate optical transceiver terminal

    Science.gov (United States)

    Clarke, E. S.

    1973-01-01

    The objectives of this study were: (1) to design a 400 Mbps optical transceiver terminal to operate from a high-altitude balloon-borne platform in order to permit the quantitative evaluation of a space-qualifiable optical communications system design, (2) to design an atmospheric propagation experiment to operate in conjunction with the terminal to measure the degrading effects of the atmosphere on the links, and (3) to design typical optical communications experiments for space-borne laboratories in the 1980-1990 time frame. As a result of the study, a transceiver package has been configured for demonstration flights during late 1974. The transceiver contains a 400 Mbps transmitter, a 400 Mbps receiver, and acquisition and tracking receivers. The transmitter is a Nd:YAG, 200 Mhz, mode-locked, CW, diode-pumped laser operating at 1.06 um requiring 50 mW for 6 db margin. It will be designed to implement Pulse Quaternary Modulation (PQM). The 400 Mbps receiver utilizes a Dynamic Crossed-Field Photomultiplier (DCFP) detector. The acquisition receiver is a Quadrant Photomultiplier Tube (QPMT) and receives a 400 Mbps signal chopped at 0.1 Mhz.

  17. The Effect of Minimum Wage Rates on High School Completion

    Science.gov (United States)

    Warren, John Robert; Hamrock, Caitlin

    2010-01-01

    Does increasing the minimum wage reduce the high school completion rate? Previous research has suffered from (1. narrow time horizons, (2. potentially inadequate measures of states' high school completion rates, and (3. potentially inadequate measures of minimum wage rates. Overcoming each of these limitations, we analyze the impact of changes in…

  18. Two-phase Flow Patterns in High Temperature Generator of Absorption Chiller / Heater

    Science.gov (United States)

    Furukawa, Masahiro; Kanuma, Hitoshi; Sekoguchi, Kotohiko; Takeishi, Masayuki

    There is a lack of information about vapor-liquid two-phase flow patterns determined using void signals in high temperature generator of absorption chiller/heater. Sensing void fraction has been hampered because lithium bromide aqueous solution of strong alkalinity is employed as working fluid at high temperature and high level of vacuum. New void sensor applicable to such difficult conditions was developed. The void Fractions at 48 locations in a high temperature generator were measured simultaneously in both cooling and heating operations. Analysis of void signals detected reveals that the most violent boiling occurs at the upper part of rear plate of combustion chamber and the first line of vertical tubes located in the flue. The flow patterns are strongly affected by the system pressure difference between the cooling and heating operations: there appear bubbly, slug and froth flows in the cooling operation, but only bubbly flow in the heating operation.

  19. Behaviors of harmonic signals in wavelength-modulated spectroscopy under high absorption strength

    Institute of Scientific and Technical Information of China (English)

    Yuntao Wang; Haiwen Cai; Jianxin Geng; Zhengqing Pan; Dijun Chen; Zujie Fang

    2007-01-01

    @@ Behaviors of harmonic signals in wavelength modulation spectroscopy (WMS) for gas detection with Lorentzian line under high absorption strength are investigated. Approximate analytic expressions of the second, fourth, and sixth harmonics on the strength are presented in concise forms. Simulations show that the expressions are in agreement with the Fourier expansion by numerical integration. It is expected theoretically and experimentally in a WMS system for methane detection that there are not only a maximum, but also a null point in the harmonics versus strength relations, which should be of practical importance in methane sensing applications.

  20. On the development of high temperature ammonia-water hybrid absorption-compression heat pumps

    DEFF Research Database (Denmark)

    Jensen, Jonas Kjær; Markussen, Wiebke Brix; Reinholdt, Lars;

    2015-01-01

    Ammonia-water hybrid absorption-compression heat pumps (HACHP) are a promising technology for development of ecient high temperature industrial heat pumps. Using 28 bar components HACHPs up to 100 °C are commercially available. Components developed for 50 bar and 140 bar show that these pressure ......, and 140 bar up to 147 °C. If the compressor discharge temperature limit is increased to 250 °C and the vapour water content constraint is removed, this becomes: 182 °C, 193 °C and 223 °C....

  1. A microscopic description of absorption in high-energy string-brane collisions

    Energy Technology Data Exchange (ETDEWEB)

    D’Appollonio, Giuseppe [Dipartimento di Fisica, Università di Cagliari and INFNCittadella Universitaria, 09042 Monserrato (Italy); Vecchia, Paolo Di [The Niels Bohr Institute, University of Copenhagen,Blegdamsvej 17, DK-2100 Copenhagen Ø (Denmark); Nordita, KTH Royal Institute of Technology and Stockholm University,Roslagstullsbacken 23, SE-10691 Stockholm (Sweden); Russo, Rodolfo [Queen Mary University of London,Mile End Road, E1 4NS London (United Kingdom); Veneziano, Gabriele [Collège de France,11 place M. Berthelot, 75005 Paris (France); Theory Division, CERN,CH-1211 Geneva 23 (Switzerland)

    2016-03-07

    We study the collision of a highly energetic light closed string off a stack of Dp-branes at (sub)string-scale impact parameters and in a regime justifying a perturbative treatment. Unlike at larger impact parameters — where elastic scattering and/or tidal excitations dominate — here absorption of the closed string by the brane system, with the associated excitation of open strings living on it, becomes important. As a first step, we study this phenomenon at the disk level, in which the energetic closed string turns into a single heavy open string at rest whose particularly simple properties are described.

  2. Glucose and maltodextrin in enteral diets have different effects on jejunal absorption of nutrients, sodium and water and on flow rate in mini pigs.

    Science.gov (United States)

    Weber, E; Ehrlein, H J

    1998-12-01

    In four mini pigs a segment of the proximal jejunum was temporarily isolated and perfused with two enteral diets containing isocaloric amounts either of glucose or maltodextrin. With regard to total energy, the diets were composed of 60% carbohydrate, 20% protein and 20% fat. The perfusion rates were 1, 2, 4, 6, and 8 kcal/min. Absorption of glucose and fat from the maltodextrin diet was significantly greater than from the glucose diet, whereas absorption of protein was only slightly enhanced. A net water absorption occurred at perfusion of the isotonic solution with maltodextrin. Perfusing the hypertonic glucose diet, water was secreted. Therefore the flow rate increased from oligomer to monomer glucose source. With enhanced flow rate sodium secretion increased. However, the sodium concentration of the effluent was determined more by the transepithelial water movement than by the sodium secretion. The present results indicate that in enteral diets with interactions among different nutrients there is a 'kinetic advantage' in glucose absorption from maltodextrin compared to glucose. However, the reduced flow rate of the maltodextrin diet due to the lower osmolality contributed to the enhanced absorption.

  3. Simplified method for ultra high-resolution photoacoustic microscopy via transient absorption.

    Science.gov (United States)

    Mattison, Scott P; Applegate, Brian E

    2014-08-01

    Photoacoustic microscopy (PAM) is a hybrid imaging modality that combines optical illumination with ultrasonic detection to achieve absorption contrast imaging of endogenous and exogenous chromophores. Optical resolution PAM achieves high lateral-resolution by tightly focusing the excitation light; however the axial resolution is still dependent upon the bandwidth of the ultrasonic transducer. As a result, PAM images have highly asymmetric voxels with submicron lateral resolution and axial resolution typically limited to tens of microns. We have previously reported on a resonant multiphoton approach to PAM called transient absorption ultrasonic microscopy (TAUM), which enables high axial resolution by frequency encoding the photoacoustic signal at the overlap of a pump and a probe beam. This approach enables photoacoustic imaging with subcellular resolution on par with other multiphoton microscopy techniques. Here, we report on an innovation that enables TAUM imaging with a much less sophisticated optical system than previously reported. If we allow the time delay between the pump and probe to collapse to zero, the pump and probe optical paths can be combined. An amplitude modulator in the single beam path is sufficient to encode the TAUM signal at the second harmonic of the modulation frequency. The resulting system is essentially a standard optical resolution PAM system that incorporates an amplitude modulator and utilizes a Fourier post processing algorithm to improve the axial resolution by approximately an order of magnitude. A prototype system based on this approach has been assembled and tested on fixed bovine erythrocytes.

  4. High reflected cubic cavity as long path absorption cell for infrared gas sensing

    Science.gov (United States)

    Yu, Jia; Gao, Qiang; Zhang, Zhiguo

    2014-10-01

    One direct and efficient method to improve the sensitivity of infrared gas sensors is to increase the optical path length of gas cells according to Beer-Lambert Law. In this paper, cubic shaped cavities with high reflected inner coating as novel long path absorption cells for infrared gas sensing were developed. The effective optical path length (EOPL) for a single cubic cavity and tandem cubic cavities were investigated based on Tunable Diode Laser Absorption Spectroscopy (TDLAS) measuring oxygen P11 line at 763 nm. The law of EOPL of a diffuse cubic cavity in relation with the reflectivity of the coating, the port fraction and side length of the cavity was obtained. Experimental results manifested an increase of EOPL for tandem diffuse cubic cavities as the decrease of port fraction of the connecting aperture f', and the EOPL equaled to the sum of that of two single cubic cavities at f'<0.01. The EOPL spectra at infrared wavelength range for different inner coatings including high diffuse coatings and high reflected metallic thin film coatings were deduced.

  5. High regression rate, high density hybrid fuels Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR program will investigate high energy density novel nanofuels combined with high density binders for use with an N2O oxidizer. Terves has developed...

  6. Contrast-enhanced specific absorption rate-efficient 3D cardiac cine with respiratory-triggered radiofrequency gating.

    Science.gov (United States)

    Henningsson, Markus; Chan, Raymond H; Goddu, Beth; Goepfert, Lois A; Razavi, Reza; Botnar, Rene M; Schaeffter, Tobias; Nezafat, Reza

    2013-04-01

    To investigate the use of radiofrequency (RF) gating in conjunction with a paramagnetic contrast agent to reduce the specific absorption rate (SAR) and increase the blood-myocardium contrast in balanced steady-state free precession (bSSFP) 3D cardiac cine. RF gating was implemented by synchronizing the RF-excitation with an external respiratory sensor (bellows), which could additionally be used for respiratory gating. For reference, respiratory-gated 3D cine images were acquired without RF gating. Free-breathing 3D cine images were acquired in eight healthy subjects before and after contrast injection (Gd-BOPTA) and compared to breath-hold 2D cine. RF-gated 3D cine reduced the SAR by nearly 40% without introducing significant artifacts while providing left ventricle (LV) measurements similar to those obtained with 2D cine. The contrast-to-noise ratio (CNR) was significantly higher for 3D cine compared to 2D cine, both before and after contrast injection; however, no statistically significant CNR increase was observed for the postcontrast 3D cine compared to the precontrast acquisitions. Respiratory-triggered RF gating significantly reduces SAR in 3D cine acquisitions, which may enable a more widespread clinical use of 3D cine. Furthermore, CNR of 3D bSSFP cine is higher than of 2D and administration of Gd-BOPTA does not improve the CNR of 3D cine. Copyright © 2012 Wiley Periodicals, Inc.

  7. Specific absorption rate dependence on temperature in magnetic field hyperthermia measured by dynamic hysteresis losses (ac magnetometry).

    Science.gov (United States)

    Garaio, Eneko; Sandre, Olivier; Collantes, Juan-Mari; Garcia, Jose Angel; Mornet, Stéphane; Plazaola, Fernando

    2015-01-09

    Magnetic nanoparticles (NPs) are intensively studied for their potential use for magnetic hyperthermia, a treatment that has passed a phase II clinical trial against severe brain cancer (glioblastoma) at the end of 2011. Their heating power, characterized by the 'specific absorption rate (SAR)', is often considered temperature independent in the literature, mainly because of the difficulties that arise from the measurement methodology. Using a dynamic magnetometer presented in a recent paper, we measure here the thermal dependence of SAR for superparamagnetic iron oxide (maghemite) NPs of four different size-ranges corresponding to mean diameters around 12 nm, 14 nm, 15 nm and 16 nm. The article reports a parametrical study extending from 10 to 60 °C in temperature, from 75 to 1031 kHz in frequency, and from 2 to 24 kA m(-1) in magnetic field strength. It was observed that SAR values of smaller NPs decrease with temperature whereas for the larger sample (16 nm) SAR values increase with temperature. The measured variation of SAR with temperature is frequency dependent. This behaviour is fully explained within the scope of linear response theory based on Néel and Brown relaxation processes, using independent magnetic measurements of the specific magnetization and the magnetic anisotropy constant. A good quantitative agreement between experimental values and theoretical values is confirmed in a tri-dimensional space that uses as coordinates the field strength, the frequency and the temperature.

  8. A high-efficiency power cycle in which hydrogen is compressed by absorption in metal hydrides.

    Science.gov (United States)

    Powell, J R; Salzano, F J; Yu, W S; Milau, J S

    1976-07-23

    A high-efficiency power cycle is proposed in which molecular hydrogen gas is used as a working fluid in a regenerative closed Brayton cycle. The hydrogen gas is compressed by an absorption-desorption cycle on metal hydride (FeTiH(x)) beds. Low-temperature solar or geothermal heat (temperature about 100 degrees C) is used for the compression process, and high-temperature fossil fuel or nuclear heat (temperature about 700 degrees C) supplies the expansion work in the turbine. Typically, about 90 percent of the high-temperature heat input is converted to electricity, while about 3 kilowatts of low-temperature heat is required per kilowatt of electrical output.

  9. Modelling millimetre wave propagation and absorption in a high resolution skin model: the effect of sweat glands

    Energy Technology Data Exchange (ETDEWEB)

    Shafirstein, Gal [Department of Otolaryngology, College of Medicine, University of Arkansas for Medical Sciences, 4301 W. Markham, 543, Little Rock, AR 72205 (United States); Moros, Eduardo G, E-mail: shafirsteingal@uams.edu [Division of Radiation Physics and Informatics, Department of Radiation Oncology, College of Medicine, University of Arkansas for Medical Sciences, 4301 W. Markham, 771, Little Rock, AR 72205 (United States)

    2011-03-07

    The aim of this work was to investigate the potential effect of sweat gland ducts (SGD) on specific absorption rate (SAR) and temperature distributions during mm-wave irradiation. High resolution electromagnetic and bio-heat transfer models of human skin with SGD were developed using a commercially available simulation software package (SEMCAD X(TM)). The skin model consisted of a 30 {mu}m stratum corneum, 350 {mu}m epidermis and papillary dermis (EPD) and 1000 {mu}m dermis. Five SGD of 60 {mu}m radius and 300 {mu}m height were embedded linearly with 370 {mu}m separation. A WR-10 waveguide positioned 20 {mu}m from the skin surface and delivering 94 GHz electromagnetic radiation was included in the model. Saline conductivity was assigned inside SGD. SAR and temperatures were computed with and without SGD. Despite their small scale, SAR was significantly higher within SGD than in the EPD without SGD. Without SGD, SAR and temperature maxima were in the dermis near EPD. With SGD, SAR maximum was inside SGD while temperature maximum moved to the EPD/stratum-corneum junction. Since the EPD participates actively in perception, the effect of SGD should be taken into account in nociceptive studies involving mm-waves. This research represents a significant step towards higher spatial resolution numerical modelling of the skin and shows that microstructures can play a significant role in mm-wave absorption and induced temperature distributions.

  10. Modelling millimetre wave propagation and absorption in a high resolution skin model: the effect of sweat glands

    Science.gov (United States)

    Shafirstein, Gal; Moros, Eduardo G.

    2011-03-01

    The aim of this work was to investigate the potential effect of sweat gland ducts (SGD) on specific absorption rate (SAR) and temperature distributions during mm-wave irradiation. High resolution electromagnetic and bio-heat transfer models of human skin with SGD were developed using a commercially available simulation software package (SEMCAD X™). The skin model consisted of a 30 µm stratum corneum, 350 µm epidermis and papillary dermis (EPD) and 1000 µm dermis. Five SGD of 60 µm radius and 300 µm height were embedded linearly with 370 µm separation. A WR-10 waveguide positioned 20 µm from the skin surface and delivering 94 GHz electromagnetic radiation was included in the model. Saline conductivity was assigned inside SGD. SAR and temperatures were computed with and without SGD. Despite their small scale, SAR was significantly higher within SGD than in the EPD without SGD. Without SGD, SAR and temperature maxima were in the dermis near EPD. With SGD, SAR maximum was inside SGD while temperature maximum moved to the EPD/stratum-corneum junction. Since the EPD participates actively in perception, the effect of SGD should be taken into account in nociceptive studies involving mm-waves. This research represents a significant step towards higher spatial resolution numerical modelling of the skin and shows that microstructures can play a significant role in mm-wave absorption and induced temperature distributions.

  11. Strain rate effect in high-speed wire drawing process

    Science.gov (United States)

    He, S.; Van Houtte, P.; Van Bael, A.; Mei, F.; Sarban, A.; Boesman, P.; Galvez, F.; Atienza, J. M.

    2002-05-01

    This paper presents a study on the strain rate effect during high-speed wire drawing process by means of finite element simulation. Based on the quasistatic stresses obtained by normal tensile tests and dynamic stresses at high strain rates by split Hopkinson pressure bar tests, the wire drawing process was simulated for low carbon steel and high carbon steel. The results show that both the deformation process and the final properties of drawn wires are influenced by the strain rate.

  12. High-Rate Strong-Signal Quantum Cryptography

    Science.gov (United States)

    Yuen, Horace P.

    1996-01-01

    Several quantum cryptosystems utilizing different kinds of nonclassical lights, which can accommodate high intensity fields and high data rate, are described. However, they are all sensitive to loss and both the high rate and the strong-signal character rapidly disappear. A squeezed light homodyne detection scheme is proposed which, with present-day technology, leads to more than two orders of magnitude data rate improvement over other current experimental systems for moderate loss.

  13. High-intensity femtosecond laser absorption by rare-gas clusters

    Institute of Scientific and Technical Information of China (English)

    李邵辉; 王成; 刘建胜; 王向欣; 朱频频; 李儒新; 倪国权; 徐至展

    2003-01-01

    The energy absorption efficiency of high-intensity (~ 1016W/cm2) femtosecond laser pulses in a dense jet of large rare-gas clusters has been measured. Experimental results show that the energy absorption efficiency is strongly dependent on the cluster size and can be higher than 90%. The measurement of the ion energy indicates that the average ion energies of argon and xenon can be as high as 90 and 100keV, respectively. The dependence of the average energy of the ions on the cluster size is also measured. At comparatively low gas backing pressure, the average ion energies of argon and xenon increase with increasing gas backing pressure. The average ion energy of argon becomes saturated gradually with further increase of the gas backing pressure. For xenon, the average ion energy drops a little after the gas backing pressure exceeds 9 bar (3.2×105 atoms/cluster). The result showing the existence of a maximum average ion energy has been interpreted within the framework of the microplasma sphere model.

  14. High Oil-absorptive Composites Prepared from Non-woven Fiber and Sponges with 4-tert- buty1styrene-EPDM-divinylbenzene Graft Polymer

    Institute of Scientific and Technical Information of China (English)

    Zhou Meihua(周美华); Cho Won-Jei

    2001-01-01

    4-tert-butylstyrene-EPDM-divinylbenzene graft terpolymer (PBED) was prepared by graft cross-polymerization in toluene using BPO as an initiator. The gel-PBED and solPBED were isolated from extraction of tetrahydrofuran (THF), and then they were identified by IR spectroscopy. The maximum oil-absorptivity of gel-PBED produced from the optinum reaction conditions was 8 420% but its swelling rate was very low. The highest oil-absorptivity of photocrosslinked sol-PBED film was 5 800%. Although its oil absorbency was not as high as gel-PBED' s, swelling rate was higher than that of gelPBED and was suitable for commercial purpose. After swelling in oil, neither gel PBED nor photocrosslinked sol-PBED film having high oil-absorptivity had sufficient mechanical strength to be taken out of oil wholly. As is known, composite technique is one of the useful methods for reinforcing them. Fibers, sponges and non-woven cloths were used as reinforcers or supporters in this work. Oil-absorptivities and swelling kinetics were evaluated by method ASTM (F726 - 81 ) and an experimental equation. The mechanical properties and the morphologies of some composites were measured by tensile tester and SEM , respectively.

  15. Photolysis rate coefficients in the upper atmosphere: Effect of line by line calculations of the O{sub 2} absorption cross section in the Schumann-Runge bands

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, Rafael P. [INFIQC, Centro Laser de Ciencias Moleculares, Departamento de Fisico Quimica, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba, 5000, Cordoba (Argentina); Palancar, Gustavo G. [INFIQC, Centro Laser de Ciencias Moleculares, Departamento de Fisico Quimica, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba, 5000, Cordoba (Argentina)]. E-mail: palancar@fcq.unc.edu.ar; Madronich, Sasha [Atmospheric Chemistry Division, National Center for Atmospheric Research, 1850 Table mesa Drive, Boulder, CO, 80303 (United States); Toselli, Beatriz M. [INFIQC, Centro Laser de Ciencias Moleculares, Departamento de Fisico Quimica, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba, 5000, Cordoba (Argentina)]. E-mail: tosellib@fcq.unc.edu.ar

    2007-03-15

    A line by line (LBL) method to calculate highly resolved O{sub 2} absorption cross sections in the Schumann-Runge (SR) bands region was developed and integrated in the widely used Tropospheric Ultraviolet Visible (TUV) model to calculate accurate photolysis rate coefficients (J values) in the upper atmosphere at both small and large solar zenith angles (SZA). In order to obtain the O{sub 2} cross section between 49,000 and 57,000cm{sup -1}, an algorithm which considers the position, strength, and half width of each spectral line was used. Every transition was calculated by using the HIgh-resolution TRANsmission molecular absorption database (HITRAN) and a Voigt profile. The temperature dependence of both the strength and the half widths was considered within the range of temperatures characteristic of the US standard atmosphere, although the results show a very good agreement also at 79K. The cross section calculation was carried out on a 0.5cm{sup -1} grid and the contributions from all the lines lying at +/-500cm{sup -1} were considered for every wavelength. Both the SR and the Herzberg continuums were included. By coupling the LBL method to the TUV model, full radiative transfer calculations that compute J values including Rayleigh scattering at high altitudes and large SZA can now be done. Thus, the J values calculations were performed for altitudes from 0 to 120km and for SZA up to 89{sup o}. The results show, in the J{sub O{sub 2}} case, differences of more than +/-10% (e.g. at 96km and 30{sup o}) when compared against the last version of the TUV model (4.4), which uses the Koppers and Murtagh parameterization for the O{sub 2} cross section. Consequently, the J values of species with cross sections overlapping the SR band region show variable differences at lower altitudes. Although many species have been analyzed, the results for only four of them (O{sub 2}, N{sub 2}O, HNO{sub 3}, CFC12) are presented. Due to the fact that the HNO{sub 3} absorption cross

  16. A shock tube and laser absorption study of ignition delay times and OH reaction rates of ketones: 2-Butanone and 3-buten-2-one

    KAUST Repository

    Badra, Jihad

    2014-03-01

    Ketones are potential biofuel candidates and are also formed as intermediate products during the oxidation of large hydrocarbons or oxygenated fuels, such as alcohols and esters. This paper presents shock tube ignition delay times and OH reaction rates of 2-butanone (C2H5COCH3) and 3-buten-2-one (C2H3COCH3). Ignition delay measurements were carried out over temperatures of 1100-1400K, pressures of 3-6.5atm, and at equivalence ratios (F{cyrillic}) of 0.5 and 1. Ignition delay times were monitored using two different techniques: pressure time history and OH absorption near 306nm. The reaction rates of hydroxyl radicals (OH) with these two ketones were measured over the temperature range of 950-1400K near 1.5atm. The OH profiles were monitored by the narrow-line-width ring-dye laser absorption of the well-characterized R1(5) line in the OH A-X (0, 0) band near 306.69nm. We found that the ignition delay times of 2-butanone and 3-buten-2-one mixtures scale with pressure as P-0.42 and P-0.52, respectively. The ignition delay times of 3-buten-2-one were longer than that of 2-butanone for stoichiometric mixtures, however, for lean mixtures (F{cyrillic}=0.5), 2-butanone had longer ignition delay times. The chemical kinetic mechanism of Serinyel et al. [1] over-predicted the ignition delay times of 2-butanone at all tested conditions, however, the discrepancies were smaller at higher pressures. The mechanism was updated with recent rate measurements to decrease discrepancy with the experimental data. A detailed chemistry for the oxidation of 3-buten-2-one was developed using rate estimation method and reasonable agreements were obtained with the measured ignition delay data. The measured reaction rate of 2-butanone with OH agreed well with the literature data, while we present the first high-temperature measurements for the reaction of OH with 3-buten-2-one. The following Arrhenius expressions are suggested over the temperature range of 950-1450K: kC2H5COCH3+OH=6.78×1013exp

  17. The high resolution vacuum ultraviolet absorption spectra of the group VI dihydrides and deuterides Rydberg series

    CERN Document Server

    Mayhew, C A

    1984-01-01

    The high resolution absorption spectra of the important group VI dihydrides and deuterides in the vacuum ultraviolet below, and up to, their first ionisation potentials are presented. These spectra were recorded using synchrotron radiation as the background light source in conjunction with a 3m normal incidence vacuum spectrograph, equipped with holographic gratings. Due to the nature of the originating orbital for the majority of optical transitions in the VUV well developed Rydberg series are observed. One particular series can be followed up to fairly high n, so that accurate values of the first ionisation potential are determined. The identifications of the Rydberg series are made from arguments relating to their oscillator strengths, quantum defects, symmetries and from comparisons with the spectra of the corresponding united atoms i.e. the inert gases. Examples of the symmetry assignments for Rydberg series from rotational band contour analyses of the lower Rydberg members for the H sub 2 S, H sub 2 Se ...

  18. Magnetic-dipolar-mode Fano resonances for microwave spectroscopy of high absorption matter

    CERN Document Server

    Vaisman, G; Shavit, R

    2015-01-01

    Study of interaction between high absorption matter and microwave radiated energy is a subject of great importance. Especially, this concerns microwave spectroscopic characterization of biological liquids. Use of effective testing methods to obtain information about physical properties of different liquids on the molecular level is one of the most important problems in biophysics. However, the standard methods based on the microwave resonant techniques are not sufficiently suitable for biological liquids because the resonance peak in a resonator with high-loss liquids is so broad that the material parameters cannot be measured correctly. Although molecular vibrations of biomolecules may have microwave frequencies, it is not thought that such resonant coupling is significant due to their low energy compared with thermal energy and the strongly dampening aqueous environment. This paper presents an innovative microwave sensing technique for different types of lossy materials, including biological liquids. The te...

  19. X-ray Absorption Imaging of High-Intensity Discharge Lamps Using Monochromatic Synchrotron Radiation

    Science.gov (United States)

    Curry, John J.; Sansonetti, Craig J.; Hechtfischer, Ulrich; Adler, Helmar G.

    2002-10-01

    We will report results from the imaging of Hg vapor in high-intensity discharge lamps using synchrotron radiation and digital detectors. These measurements extend previous work on x-ray absorption imaging in arc lamps using an x-ray tube and a passive phosphor image plate detector^i. The large x-ray flux obtained from the Advanced Photon Source (Argonne National Laboratory) combined with the electronic gating capabilities of an intensified charge-coupled device detector have allowed us to obtain time-resolved Hg distributions with high spatial resolution. Monochromatic synchrotron radiation improves the accuracy over what can be obtained with quasi-continuum radiation from an x-ray tube source. ^iJ. J. Curry, M. Sakai, and J. E. Lawler, Journal of Applied Physics 84, 3066 (1998).

  20. kspectrum: an open-source code for high-resolution molecular absorption spectra production

    Science.gov (United States)

    Eymet, V.; Coustet, C.; Piaud, B.

    2016-01-01

    We present the kspectrum, scientific code that produces high-resolution synthetic absorption spectra from public molecular transition parameters databases. This code was originally required by the atmospheric and astrophysics communities, and its evolution is now driven by new scientific projects among the user community. Since it was designed without any optimization that would be specific to any particular application field, its use could also be extended to other domains. kspectrum produces spectral data that can subsequently be used either for high-resolution radiative transfer simulations, or for producing statistic spectral model parameters using additional tools. This is a open project that aims at providing an up-to-date tool that takes advantage of modern computational hardware and recent parallelization libraries. It is currently provided by Méso-Star (http://www.meso-star.com) under the CeCILL license, and benefits from regular updates and improvements.

  1. High precision measurement of formaldehyde in air with differential optical absorption spectroscopy

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The formaldehyde (HCHO) measurement is described by differential optical absorption spectroscopy (DOAS) technique and the data processing method is discussed in detail, including the selection of retrieval wavelength band, the removing of interfering structures, the steps of data processing and the spectrum dealing with nonlinear method. The HCHO concentration retrieved in different wavelength bands were compared, including relative error, repeatability and detection limit. As a result, the band from 314 to 332 nm was most suitable for the retrieval of HCHO. With these methods, high measurement precision of 1.9% was obtained and the detection limit of HCHO is less than 1.5 ppb. In addition, high linear relativity 0.9999 is achieved by measuring five different concentrations of HCHO with this system.

  2. High Blood Pressure Rates Have Doubled Worldwide Since 1975

    Science.gov (United States)

    ... https://medlineplus.gov/news/fullstory_162069.html High Blood Pressure Rates Have Doubled Worldwide Since 1975 Most of ... News) -- The number of people worldwide with high blood pressure has nearly doubled over the past 40 years, ...

  3. [Study on lead absorption in pumpkin by atomic absorption spectrophotometry].

    Science.gov (United States)

    Li, Zhen-Xia; Sun, Yong-Dong; Chen, Bi-Hua; Li, Xin-Zheng

    2008-07-01

    A study was carried out on the characteristic of lead absorption in pumpkin via atomic absorption spectrophotometer. The results showed that lead absorption amount in pumpkin increased with time, but the absorption rate decreased with time; And the lead absorption amount reached the peak in pH 7. Lead and cadmium have similar characteristic of absorption in pumpkin.

  4. Integrative fitting of absorption line profiles with high accuracy, robustness, and speed

    Science.gov (United States)

    Skrotzki, Julian; Habig, Jan Christoph; Ebert, Volker

    2014-08-01

    The principle of the integrative evaluation of absorption line profiles relies on the numeric integration of absorption line signals to retrieve absorber concentrations, e.g., of trace gases. Thus, it is a fast and robust technique. However, previous implementations of the integrative evaluation principle showed shortcomings in terms of accuracy and the lack of a fit quality indicator. This has motivated the development of an advanced integrative (AI) fitting algorithm. The AI fitting algorithm retains the advantages of previous integrative implementations—robustness and speed—and is able to achieve high accuracy by introduction of a novel iterative fitting process. A comparison of the AI fitting algorithm with the widely used Levenberg-Marquardt (LM) fitting algorithm indicates that the AI algorithm has advantages in terms of robustness due to its independence from appropriately chosen start values for the initialization of the fitting process. In addition, the AI fitting algorithm shows speed advantages typically resulting in a factor of three to four shorter computational times on a standard personal computer. The LM algorithm on the other hand retains advantages in terms of a much higher flexibility, as the AI fitting algorithm is restricted to the evaluation of single absorption lines with precomputed line width. Comparing both fitting algorithms for the specific application of in situ laser hygrometry at 1,370 nm using direct tunable diode laser absorption spectroscopy (TDLAS) suggests that the accuracy of the AI algorithm is equivalent to that of the LM algorithm. For example, a signal-to-noise ratio of 80 and better typically yields a deviation of TDLAS hygrometry at the aerosol and cloud chamber aerosol interactions and dynamics in the atmosphere (AIDA)—a unique large-scale facility to study atmospheric processes. The robustness of the AI fitting algorithm has been validated for typical AIDA conditions encompassing strong transmission fluctuations

  5. Determination of sulfur in food by high resolution continuum source flame molecular absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Zambrzycka, Elżbieta; Godlewska-Żyłkiewicz, Beata, E-mail: bgodlew@uwb.edu.pl

    2014-11-01

    In the present work, a fast, simple and sensitive analytical method for determination of sulfur in food and beverages by high resolution continuum source flame molecular absorption spectrometry was developed. The determination was performed via molecular absorption of carbon monosulfide, CS. Different CS rotational lines (257.959 nm, 258.033 nm, 258.055 nm), number of pixels and types of standard solution of sulfur, namely: sulfuric acid, sodium sulfate, ammonium sulfate, sodium sulfite, sodium sulfide, DL-cysteine, and L-cystine, were studied in terms of sensitivity, repeatability of results as well as limit of detection and limit of quantification. The best results were obtained for measurements of absorption of the CS molecule at 258.055 nm at the wavelength range covering 3 pixels and DL-cysteine in 0.2 mol L{sup −1} HNO{sub 3} solution as a calibration standard. Under optimized conditions the limit of detection and the limit of quantification achieved for sulfur were 10.9 mg L{sup −1} and 36.4 mg L{sup −1}, respectively. The repeatability of the results expressed as relative standard deviation was typically < 5%. The accuracy of the method was tested by analysis of digested biological certified reference materials (soya bean flour, corn flour and herbs) and recovery experiment for beverage samples with added known amount of sulfur standard. The recovery of analyte from such samples was in the range of 93–105% with the repeatability in the range of 4.1–5.0%. The developed method was applied for the determination of sulfur in milk (194 ± 10 mg kg{sup −1}), egg white (2188 ± 29 mg kg{sup −1}), mineral water (31.0 ± 0.9 mg L{sup −1}), white wine (260 ± 4 mg L{sup −1}) and red wine (82 ± 2 mg L{sup −1}), as well as in sample rich in ions, such as bitter mineral water (6900 ± 100 mg L{sup −1}). - Highlights: • HR-CS FMAS technique was used for sulfur measurement via molecular absorption of carbon monosulfide, CS. • Organic DL

  6. Single Longitudinal Mode, High Repetition Rate, Q-switched Ho:YLF Laser for Remote Sensing

    Science.gov (United States)

    Bai, Yingxin; Yu, Jirong; Petzar, Paul; Petros, M.; Chen, Songsheng; Trieu, Bo; Lee, Nyung; Singh, U.

    2009-01-01

    Ho:YLF/LuLiF lasers have specific applications for remote sensing such as wind-speed measurement and carbon dioxide (CO2) concentration measurement in the atmosphere because the operating wavelength (around 2 m) is located in the eye-safe range and can be tuned to the characteristic lines of CO2 absorption and there is strong backward scattering signal from aerosol (Mie scattering). Experimentally, a diode pumped Ho:Tm:YLF laser has been successfully used as the transmitter of coherent differential absorption lidar for the measurement of with a repetition rate of 5 Hz and pulse energy of 75 mJ [1]. For highly precise CO2 measurements with coherent detection technique, a laser with high repetition rate is required to averaging out the speckle effect [2]. In addition, laser efficiency is critically important for the air/space borne lidar applications, because of the limited power supply. A diode pumped Ho:Tm:YLF laser is difficult to efficiently operate in high repetition rate due to the large heat loading and up-conversion. However, a Tm:fiber laser pumped Ho:YLF laser with low heat loading can be operated at high repetition rates efficiently [3]. No matter whether wind-speed or carbon dioxide (CO2) concentration measurement is the goal, a Ho:YLF/LuLiF laser as the transmitter should operate in a single longitudinal mode. Injection seeding is a valid technique for a Q-switched laser to obtain single longitudinal mode operation. In this paper, we will report the new results for a single longitudinal mode, high repetition rate, Q-switched Ho:YLF laser. In order to avoid spectral hole burning and make injection seeding easier, a four mirror ring cavity is designed for single longitudinal mode, high repetition rate Q-switched Ho:YLF laser. The ramp-fire technique is chosen for injection seeding.

  7. Magnetic-dipolar-mode Fano resonances for microwave spectroscopy of high absorption matter

    Science.gov (United States)

    Vaisman, G.; Kamenetskii, E. O.; Shavit, R.

    2015-03-01

    The interaction between high absorption matter and microwave radiated energy is a subject of great importance. In particular, this concerns the microwave spectroscopic characterization of biological liquids. The use of effective testing methods to obtain information about physical properties of different liquids on the molecular level is one of the most important problems in biophysics. However, the standard methods based on microwave resonant techniques are not sufficiently suitable for biological liquids because the resonance peak in a resonator with high-loss liquids is so broad that the material parameters cannot be measured correctly. Although molecular vibrations of biomolecules may have microwave frequencies, it is not thought that such resonant coupling is significant due to their low energy compared with thermal energy and the strongly dampening aqueous environment. This paper presents an innovative microwave sensing technique for different types of lossy materials, including biological liquids. The technique is based on the combination of the microwave perturbation method and the Fano resonance effects observed recently in microwave structures with embedded magnetic-dipolar quantum dots. When the frequency of the magnetic dipolar mode (MDM) resonance is not equal to the cavity resonance frequency, one gets Fano transmission intensity. When the MDM resonance frequency is tuned to the cavity resonance frequency, by a bias magnetic field, one observes a Lorentzian line shape. Use of an extremely narrow Lorentzian peak allows exact probing of the resonant frequency of a cavity loaded by a highly lossy material sample. For different kinds of samples, one has different frequencies of Lorentzian peaks. This presents a picture of precise spectroscopic characterization of high absorption matter in microwaves.

  8. Correction for a measurement artifact of the Multi-Angle Absorption Photometer (MAAP at high black carbon mass concentration levels

    Directory of Open Access Journals (Sweden)

    A.-P. Hyvärinen

    2013-01-01

    Full Text Available The Multi-Angle Absorption Photometer (MAAP is a widely-used instrument for aerosol black carbon (BC measurements. In this paper, we show correction methods for an artifact found to affect the instrument accuracy in environments characterized by high black carbon concentrations. The artifact occurs after a filter spot change – as BC mass is accumulated on a fresh filter spot, the attenuation of the light (raw signal is weaker than anticipated. This causes a sudden decrease, followed by a gradual increase in measured BC concentration. The artifact is present in the data when the BC concentration exceeds ~3 μg m−3 at the typical MAAP flow rate of 16.7 L min−1 or 1 m3 h−1. The artifact is caused by erroneous dark counts in the photodetector measuring the transmitted light, in combination with an instrument internal averaging procedure of the photodetector raw signals. It was found that, in addition to the erroneous temporal response of the data, concentrations higher than 9 μg m−3 (at the flow rate of 16.7 L min−1 are underestimated by the MAAP. The underestimation increases with increasing BC accumulation rate. At a flow rate of 16.7 L min−1 and concentration of about 24 μg m−3 (BC accumulation rate ~0.4 μg min−1, the underestimation is about 30%. There are two ways of overcoming the MAAP artifact. One method is by logging the raw signal of the 165° photomultiplier measuring the reflected light from the filter spot. As this signal is not affected by the artifact, it can be converted to approximately correct absorption and BC values. However, as the typical print formats of the MAAP do not give the reflected signal as an output, a semi-empirical correction method was developed based on laboratory experiments to correct for the results in the post-processing phase. The correction function was applied to three MAAP datasets from

  9. Correction for a measurement artifact of the Multi-Angle Absorption Photometer (MAAP at high black carbon mass concentration levels

    Directory of Open Access Journals (Sweden)

    A.-P. Hyvärinen

    2012-09-01

    Full Text Available The Multi-Angle Absorption Photometer (MAAP is a widely-used instrument for aerosol black carbon observations. In this paper, we show correction methods for an artifact found to affect the instrument accuracy in environments with high black carbon concentrations. The artifact occurs after a filter spot change – as BC mass is accumulated on a fresh filter spot, the attenuation of the light (raw signal is weaker than anticipated. This causes a sudden decrease, followed by a gradual increase in measured BC concentration. The artifact is present in the data when the BC concentration exceeds ∼3 μg m−3 at the typical MAAP flow rate of 16.7 l min−1 or 1 m3 h−1. The artifact is caused by erroneous dark counts in the photo detector measuring the transmitted light, in combination with an instrument internal averaging procedure of the photo detector raw signals. It was found that in addition to the erroneous temporal response of the data, concentrations higher than 9 μg m−3 (at the flow rate of 16.7 l min−1 are underestimated by the MAAP. The underestimation increases with increasing BC accumulation rate. At a flow rate of 16.7 l min−1 and concentration of about 24 μg m−3 (BC accumulation rate ∼0.4 μg min−1, the underestimation is about 30%. There are two ways of overcoming the MAAP artifact. One method is by logging the raw signal of the 165° photomultiplier measuring the reflected light from the filter spot. As this signal is not affected by the artifact, it can be converted to approximately correct absorption and BC values. However, as the typical print formats of the MAAP do not give the reflected signal as an output, a semi-empirical correction method was developed based on laboratory experiments to correct for the results in the post-processing phase. The correction function was applied to three MAAP datasets from Gual Pahari

  10. Correction for a measurement artifact of the Multi-Angle Absorption Photometer (MAAP) at high black carbon mass concentration levels

    Science.gov (United States)

    Hyvärinen, A.-P.; Vakkari, V.; Laakso, L.; Hooda, R. K.; Sharma, V. P.; Panwar, T. S.; Beukes, J. P.; van Zyl, P. G.; Josipovic, M.; Garland, R. M.; Andreae, M. O.; Pöschl, U.; Petzold, A.

    2013-01-01

    The Multi-Angle Absorption Photometer (MAAP) is a widely-used instrument for aerosol black carbon (BC) measurements. In this paper, we show correction methods for an artifact found to affect the instrument accuracy in environments characterized by high black carbon concentrations. The artifact occurs after a filter spot change - as BC mass is accumulated on a fresh filter spot, the attenuation of the light (raw signal) is weaker than anticipated. This causes a sudden decrease, followed by a gradual increase in measured BC concentration. The artifact is present in the data when the BC concentration exceeds ~3 μg m-3 at the typical MAAP flow rate of 16.7 L min-1 or 1 m3 h-1. The artifact is caused by erroneous dark counts in the photodetector measuring the transmitted light, in combination with an instrument internal averaging procedure of the photodetector raw signals. It was found that, in addition to the erroneous temporal response of the data, concentrations higher than 9 μg m-3 (at the flow rate of 16.7 L min-1) are underestimated by the MAAP. The underestimation increases with increasing BC accumulation rate. At a flow rate of 16.7 L min-1 and concentration of about 24 μg m-3 (BC accumulation rate ~0.4 μg min-1), the underestimation is about 30%. There are two ways of overcoming the MAAP artifact. One method is by logging the raw signal of the 165° photomultiplier measuring the reflected light from the filter spot. As this signal is not affected by the artifact, it can be converted to approximately correct absorption and BC values. However, as the typical print formats of the MAAP do not give the reflected signal as an output, a semi-empirical correction method was developed based on laboratory experiments to correct for the results in the post-processing phase. The correction function was applied to three MAAP datasets from Gual Pahari (India), Beijing (China), and Welgegund (South Africa). In Beijing, the results could also be compared against a

  11. High-resolution absorption spectroscopy of the OH 2Pi 3/2 ground state line

    CERN Document Server

    Wiesemeyer, Helmut; Heyminck, Stefan; Karl, Jacobs; Menten, Karl; Neufeld, David; Requena-Torres, Miguel Angel; Stutzki, Jürgen; 10.1051/0004-6361/201218915

    2012-01-01

    The chemical composition of the interstellar medium is determined by gas phase chemistry, assisted by grain surface reactions, and by shock chemistry. The aim of this study is to measure the abundance of the hydroxyl radical (OH) in diffuse spiral arm clouds as a contribution to our understanding of the underlying network of chemical reactions. Owing to their high critical density, the ground states of light hydrides provide a tool to directly estimate column densities by means of absorption spectroscopy against bright background sources. We observed onboard the SOFIA observatory the 2Pi3/2, J = 5/2 3/2 2.5 THz line of ground-state OH in the diffuse clouds of the Carina-Sagittarius spiral arm. OH column densities in the spiral arm clouds along the sightlines to W49N, W51 and G34.26+0.15 were found to be of the order of 10^14 cm^-2, which corresponds to a fractional abundance of 10^-7 to 10^-8, which is comparable to that of H_2O. The absorption spectra of both species have similar velocity components, and the...

  12. Carbon Hollow Microspheres with a Designable Mesoporous Shell for High-Performance Electromagnetic Wave Absorption.

    Science.gov (United States)

    Xu, Hailong; Yin, Xiaowei; Zhu, Meng; Han, Meikang; Hou, Zexin; Li, Xinliang; Zhang, Litong; Cheng, Laifei

    2017-02-22

    In this work, mesoporous carbon hollow microspheres (PCHMs) with designable mesoporous shell and interior void are constructed by a facile in situ stöber templating approach and a pyrolysis-etching process. The PCHMs are characterized by scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectra, Raman spectroscopy, and nitrogen adsorption and desorption system. A uniform mesoporous shell (pore size 4.7 nm) with a thickness of 55 nm and a cavity size of 345 nm is realized. The composite of paraffin mixed with 20 wt % PCHMs exhibits a minimum reflection coefficient (RCmin) of -84 dB at 8.2 GHz with a sample thickness of 3.9 mm and an effective absorption bandwidth (EAB) of 4.8 GHz below -10 dB (>90% electromagnetic wave is attenuated). Moreover, the composite of phenolic resin mixed with 20 wt % PCHMs exhibits an ultrawide EAB of 8 GHz below -10 dB with a thinner thickness of 2.15 mm. Such excellent electromagnetic wave absorption properties are ascribed to the large carbon-air interface in the mesoporous shell and interior void, which is favorable for the matching of characteristic impedance as compared with carbon hollow microspheres and carbon solid microspheres. Considering the excellent performance of PCHMs, we believe the as-fabricated PCHMs can be promising candidates as highly effective microwave absorbers, and the design philosophy can be extended to other spherical absorbers.

  13. High-shear-rate capillary viscometer for inkjet inks

    Energy Technology Data Exchange (ETDEWEB)

    Wang Xi [FUJIFILM Dimatix, Inc., Lebanon, New Hampshire 03766 (United States); Carr, Wallace W.; Bucknall, David G. [School of Polymer, Textile, and Fiber Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); Morris, Jeffrey F. [Department of Chemical Engineering and Benjamin Levich Institute for Physico-Chemical Hydrodynamics, City College of New York, New York, New York 10031 (United States)

    2010-06-15

    A capillary viscometer developed to measure the apparent shear viscosity of inkjet inks at high apparent shear rates encountered during inkjet printing is described. By using the Weissenberg-Rabinowitsch equation, true shear viscosity versus true shear rate is obtained. The device is comprised of a constant-flow generator, a static pressure monitoring device, a high precision submillimeter capillary die, and a high stiffness flow path. The system, which is calibrated using standard Newtonian low-viscosity silicone oil, can be easily operated and maintained. Results for measurement of the shear-rate-dependent viscosity of carbon-black pigmented water-based inkjet inks at shear rates up to 2x10{sup 5} s{sup -1} are discussed. The Cross model was found to closely fit the experimental data. Inkjet ink samples with similar low-shear-rate viscosities exhibited significantly different shear viscosities at high shear rates depending on particle loading.

  14. Quantification of the fluorine containing drug 5-fluorouracil in cancer cells by GaF molecular absorption via high-resolution continuum source molecular absorption spectrometry

    Science.gov (United States)

    Krüger, Magnus; Huang, Mao-Dong; Becker-Roß, Helmut; Florek, Stefan; Ott, Ingo; Gust, Ronald

    The development of high-resolution continuum source molecular absorption spectrometry made the quantification of fluorine feasible by measuring the molecular absorption as gallium monofluoride (GaF). Using this new technique, we developed on the example of 5-fluorouracil (5-FU) a graphite furnace method to quantify fluorine in organic molecules. The effect of 5-FU on the generation of the diatomic GaF molecule was investigated. The experimental conditions such as gallium nitrate amount, temperature program, interfering anions (represented as corresponding acids) and calibration for the determination of 5-FU in standard solution and in cellular matrix samples were investigated and optimized. The sample matrix showed no effect on the sensitivity of GaF molecular absorption. A simple calibration curve using an inorganic sodium fluoride solution can conveniently be used for the calibration. The described method is sensitive and the achievable limit of detection is 0.23 ng of 5-FU. In order to establish the concept of "fluorine as a probe in medicinal chemistry" an exemplary application was selected, in which the developed method was successfully demonstrated by performing cellular uptake studies of the 5-FU in human colon carcinoma cells.

  15. Circuit and interconnect design for high bit-rate applications

    NARCIS (Netherlands)

    Veenstra, H.

    2006-01-01

    This thesis presents circuit and interconnect design techniques and design flows that address the most difficult and ill-defined aspects of the design of ICs for high bit-rate applications. Bottlenecks in interconnect design, circuit design and on-chip signal distribution for high bit-rate applicati

  16. High Graduate Unemployment Rate and Taiwanese Undergraduate Education

    Science.gov (United States)

    Wu, Chih-Chun

    2011-01-01

    An expansion in higher education in combination with the recent global economic recession has resulted in a high college graduate unemployment rate in Taiwan. This study investigates how the high unemployment rate and financial constraints caused by economic cutbacks have shaped undergraduates' class choices, job needs, and future income…

  17. HIGH-RATE DISINFECTION TECHNIQUES FOR COMBIND SEWER OVERFLOW

    Science.gov (United States)

    This paper presents high-rate disinfection technologies for combined sewer overflow (CSO). The high-rate disinfection technologies of interest are: chlorination/dechlorination, ultraviolet light irradiation (UV), chlorine dioxide (ClO2 ), ozone (O3), peracetic acid (CH3COOOH )...

  18. Size dependence of the spontaneous emission rate and absorption cross section of CdSe and CdTe quantum dots

    NARCIS (Netherlands)

    de Mello Donega, C.; Koole, R.

    2009-01-01

    In this paper, the size dependence of the band gap, of the spontaneous emission rate, and of the absorption cross section of quantum dots is systematically investigated over a wide size range, using colloidal CdSe and CdTe QDs as model systems (diameters ranging from 1.2 to 8 nm and from 2 to 9.5 nm

  19. Quantification of the fluorine containing drug 5-fluorouracil in cancer cells by GaF molecular absorption via high-resolution continuum source molecular absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Krueger, Magnus [Freie Universitaet Berlin, Institut fuer Pharmazie, Pharmazeutische Chemie, Koenigin-Luise-Str. 2-4, 14195 Berlin (Germany); Huang, Mao-Dong; Becker-Ross, Helmut; Florek, Stefan [Leibniz Institut fuer Analytische Wissenschaften, ISAS-e.V., Department Berlin, Albert-Einstein-Str. 9, 12489 Berlin (Germany); Ott, Ingo [Technische Universitaet Carolo Wilhelmina zu Braunschweig, Institut fuer Medizinische und Pharmazeutische Chemie, Beethovenstr. 55, 38106 Braunschweig (Germany); Gust, Ronald, E-mail: ronald.gust@uibk.ac.at [Universitaet Innsbruck, Institut fuer Pharmazie, Pharmazeutische Chemie, Innrain 80/82, 6020 Innsbruck (Austria)

    2012-03-15

    The development of high-resolution continuum source molecular absorption spectrometry made the quantification of fluorine feasible by measuring the molecular absorption as gallium monofluoride (GaF). Using this new technique, we developed on the example of 5-fluorouracil (5-FU) a graphite furnace method to quantify fluorine in organic molecules. The effect of 5-FU on the generation of the diatomic GaF molecule was investigated. The experimental conditions such as gallium nitrate amount, temperature program, interfering anions (represented as corresponding acids) and calibration for the determination of 5-FU in standard solution and in cellular matrix samples were investigated and optimized. The sample matrix showed no effect on the sensitivity of GaF molecular absorption. A simple calibration curve using an inorganic sodium fluoride solution can conveniently be used for the calibration. The described method is sensitive and the achievable limit of detection is 0.23 ng of 5-FU. In order to establish the concept of 'fluorine as a probe in medicinal chemistry' an exemplary application was selected, in which the developed method was successfully demonstrated by performing cellular uptake studies of the 5-FU in human colon carcinoma cells. - Highlights: Black-Right-Pointing-Pointer Development of HR-CS MAS for quantification of fluorine bound to organic molecules Black-Right-Pointing-Pointer Measuring as molecular absorption of gallium monofluoride Black-Right-Pointing-Pointer Quantification of organic-bound fluorine in biological material Black-Right-Pointing-Pointer The concept of 'fluorine as a probe in medicinal chemistry' could be established.

  20. The relation between the specific absorption rate and electromagnetic field intensity for heterogeneous exposure conditions at mobile communications frequencies.

    Science.gov (United States)

    Neubauer, Georg; Preiner, Patrick; Cecil, Stefan; Mitrevski, Niki; Gonter, Johannes; Garn, Heinrich

    2009-12-01

    The relation between the incident electromagnetic field strength and both the whole-body and the local specific absorption rate (SAR) was investigated for typical heterogeneous exposure scenarios for frequencies relevant for mobile communication. The results were compared to results from plane wave exposure. Heterogeneous exposure arises from multiple path propagation of the electromagnetic waves to the location of interest. It is shown that plane wave exposure does not represent worst-case exposure conditions. When the electric field strength arising at plane wave exposure is compared to the electric field strength averaged over the volume of the human body occurring during multipath exposure, 12% of all heterogeneous cases examined represent worse exposure conditions than plane wave exposure for whole-body exposure at 946 MHz, 15% at 1840 MHz, and 22% at 2140 MHz. The deviation between plane wave and heterogeneous whole-body SAR ranges from -54% to 54%. For partial-body SAR averaged over 10 g of tissue, a range from -93% to 209% was found when comparing multiple wave exposure to single incoming plane waves. The investigations performed using the Visible Human as phantom showed that the basic restrictions are met as long as the reference levels are not exceeded. However, this must not be necessarily the case when different phantoms are used to perform similar investigations because recent studies demonstrated that reference levels might not be conservative when phantoms of children are used. Therefore, the results of this work indicate the need to extend the investigations to numerical simulations with additional human phantoms representing parts of the human population having different anatomy and morphology compared to the phantom used within the frame of this project. This also applies to phantoms of children.

  1. Study of specific absorption rate of strontium doped lanthanum manganite nanoparticles for self-controlled hyperthermia applications

    Energy Technology Data Exchange (ETDEWEB)

    Rashid, Amin ur; Ahmed, Ashfaq [Magnetism Laboratory, Department of Physics, COMSATS Institute of Information Technology, Islamabad (Pakistan); Ahmad, S.N. [National Center for Physics, 44000 Islamabad (Pakistan); Shaheen, S.A. [Department of Physics, Florida State University, Tallahassee, FL 32310 (United States); Manzoor, Sadia, E-mail: sadia_manzoor@comsats.edu.pk [Magnetism Laboratory, Department of Physics, COMSATS Institute of Information Technology, Islamabad (Pakistan)

    2013-12-15

    Magnetic and magnetothermal properties of strontium doped lanthanum manganite La{sub 1−x}Sr{sub x}MnO{sub 3} nanoparticles have been studied with the strontium concentration x varying between 0.15 and 0.45. La{sub 1−x}Sr{sub x}MnO{sub 3} nanoparticles were prepared by the citrate gel route. XRD results show that all samples exhibit the characteristic perovskite structure with average particle sizes between 33 and 44 nm. Adiabatic magnetothermia measurements were carried out in an RF magnetic field of 800 A/m and 214 kHz. Both magnetic and thermomagnetic behaviors are governed by the strontium content of the samples. The saturation magnetization, Curie temperature and specific absorption rate (SAR) vary non-monotonically with x. The SAR of the nanoparticles has been calculated using the linear response theory and good agreement with the experimental data has been observed. The intrinsic loss power (ILP) has been obtained from the SAR values. ILP values of our samples are comparable to those of magnetite. - Highlights: • Using linear response theory (LRT) to calculate SAR for La{sub 1−x}Sr{sub x}MnO{sub 3} system. • Found good agreement between the calculated and experimentally determined SAR. • LRT reproduces SAR in a compositionally dependent magnetic properties system. • Intrinsic loss power (ILP) is comparable to that of commercial ferrofluids. • Curie temperature of x=0.15, 0.2 are suitable for self-controlled hyperthermia.

  2. Possible high absorptance and low emittance selective surface for high temperature solar thermal collectors.

    Science.gov (United States)

    Zhang, Q C; Kelly, J C; Mills, D R

    1991-05-01

    Optical reflectivity measurements show that the reflectivity of Ge is dramatically reduced in the wavelength 0.3-1.4-microm range after high dose oxygen ion implantation. To explain such greatly reduced reflectivity, a model has been developed for the reflectivity of high dose oxygen implanted germanium. Our experimentally measured and calculated reflectivities show that, for a layered structure consisting of a Ge and GeO(2) mixture on Ge on GeO(2) on a Cu substrate, a low reflectivity of 0-10% in the solar spectrum is obtained, together with a high reflectivity approximately 100% in the 1.7-25-microm wavelength range. This is close to that of an ideal selective surface for solar energy thermal collectors operating at high temperatures from 300 to 500 degrees C.

  3. Characterization of Metalloproteins by High-throughput X-ray Absorption Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    W Shi; M Punta; J Bohon; J Sauder; R DMello; M Sullivan; J Toomey; D Abel; M Lippi; et al.

    2011-12-31

    High-throughput X-ray absorption spectroscopy was used to measure transition metal content based on quantitative detection of X-ray fluorescence signals for 3879 purified proteins from several hundred different protein families generated by the New York SGX Research Center for Structural Genomics. Approximately 9% of the proteins analyzed showed the presence of transition metal atoms (Zn, Cu, Ni, Co, Fe, or Mn) in stoichiometric amounts. The method is highly automated and highly reliable based on comparison of the results to crystal structure data derived from the same protein set. To leverage the experimental metalloprotein annotations, we used a sequence-based de novo prediction method, MetalDetector, to identify Cys and His residues that bind to transition metals for the redundancy reduced subset of 2411 sequences sharing <70% sequence identity and having at least one His or Cys. As the HT-XAS identifies metal type and protein binding, while the bioinformatics analysis identifies metal-binding residues, the results were combined to identify putative metal-binding sites in the proteins and their associated families. We explored the combination of this data with homology models to generate detailed structure models of metal-binding sites for representative proteins. Finally, we used extended X-ray absorption fine structure data from two of the purified Zn metalloproteins to validate predicted metalloprotein binding site structures. This combination of experimental and bioinformatics approaches provides comprehensive active site analysis on the genome scale for metalloproteins as a class, revealing new insights into metalloprotein structure and function.

  4. Enhancing microalgal photosynthesis and productivity in wastewater treatment high rate algal ponds for biofuel production.

    Science.gov (United States)

    Sutherland, Donna L; Howard-Williams, Clive; Turnbull, Matthew H; Broady, Paul A; Craggs, Rupert J

    2015-05-01

    With microalgal biofuels currently receiving much attention, there has been renewed interest in the combined use of high rate algal ponds (HRAP) for wastewater treatment and biofuel production. This combined use of HRAPs is considered to be an economically feasible option for biofuel production, however, increased microalgal productivity and nutrient removal together with reduced capital costs are needed before it can be commercially viable. Despite HRAPs being an established technology, microalgal photosynthesis and productivity is still limited in these ponds and is well below the theoretical maximum. This paper critically evaluates the parameters that limit microalgal light absorption and photosynthesis in wastewater HRAPs and examines biological, chemical and physical options for improving light absorption and utilisation, with the view of enhancing biomass production and nutrient removal.

  5. Photothermal Microscopy for High Sensitivity and High Resolution Absorption Contrast Imaging of Biological Tissues

    Directory of Open Access Journals (Sweden)

    Jun Miyazaki

    2017-04-01

    Full Text Available Photothermal microscopy is useful to visualize the distribution of non-fluorescence chromoproteins in biological specimens. Here, we developed a high sensitivity and high resolution photothermal microscopy with low-cost and compact laser diodes as light sources. A new detection scheme for improving signal to noise ratio more than 4-fold is presented. It is demonstrated that spatial resolution in photothermal microscopy is up to nearly twice as high as that in the conventional widefield microscopy. Furthermore, we demonstrated the ability for distinguishing or identifying biological molecules with simultaneous muti-wavelength imaging. Simultaneous photothermal and fluorescence imaging of mouse brain tissue was conducted to visualize both neurons expressing yellow fluorescent protein and endogenous non-fluorescent chromophores.

  6. Ultra-broadband nonlinear saturable absorption of high-yield MoS2 nanosheets.

    Science.gov (United States)

    Wei, Rongfei; Zhang, Hang; Hu, Zhongliang; Qiao, Tian; He, Xin; Guo, Qiangbing; Tian, Xiangling; Chen, Zhi; Qiu, Jianrong

    2016-07-29

    High-yield MoS2 nanosheets with strong nonlinear optical (NLO) responses in a broad near-infrared range were synthesized by a facile hydrothermal method. The observation of saturable absorption, which was excited by the light with photon energy smaller than the gap energy of MoS2, can be attributed to the enhancement of the hybridization between the Mo d-orbital and S p-orbital by the oxygen incorporation into MoS2. High-yield MoS2 nanosheets with high modulation depth and large saturable intensity generated a stable, passively Q-switched fiber laser pulse at 1.56 μm. The high output power of 1.08 mW can be attained under a very low pump power of 30.87 mW. Compared to recently reported passively Q-switched fiber lasers utilizing exfoliated MoS2 nanosheets, the efficiency of the laser for our passive Q-switching operation is larger and reaches 3.50%. This research may extend the understanding on the NLO properties of MoS2 and indicate the feasibility of the high-yield MoS2 nanosheets to passively Q-switched fiber laser effectively at low pump strengths.

  7. Measurement of CO2 concentration at high-temperature based on tunable diode laser absorption spectroscopy

    Science.gov (United States)

    Chen, Jiuying; Li, Chuanrong; Zhou, Mei; Liu, Jianguo; Kan, Ruifeng; Xu, Zhenyu

    2017-01-01

    A diode laser sensor based on absorption spectroscopy has been developed for sensitive measurement of CO2 concentration at high-temperature. Measurement of CO2 can provide information about the extent of combustion and mix in a combustor that may be used to improve fuel efficiency. Most methods of in-situ combustion measurement of CO2 use the spectroscopic parameters taken from database like HITEMP which is mainly derived from the theoretical calculation and remains a high degree of uncertainty in the spectroscopic parameters. A fiber-coupled diode laser system for measurement of CO2 in combustion environment by use of the high-temperature spectroscopic parameters which are obtained by experiment was proposed. Survey spectra of the R(50) line of CO2 at 5007.787 cm-1 were recorded at high-temperature and various pressures to determine line intensities. The line intensities form the theoretical foundation for future applications of this diode laser sensor system. Survey spectra of four test gas mixtures containing 5.01%CO2, 10.01%CO2, 20.08%CO2, and 49.82%CO2 were measured to verify the accuracy of the diode laser sensor system. The measured results indicate that this sensor can measure CO2 concentration with 2% uncertainty in high temperatures.

  8. Boiling Heat Transfer in High Temperature Generator of Absorption Chiller/Heater

    Science.gov (United States)

    Furukawa, Masahiro; Enomoto, Eiichi; Sekoguchi, Kotohiko

    The heat transfer performance of forced convective boiling was tested using a high temperature generator of absorption chiller/heater, the rear furnace wall of which was composed of two different surfaces; i. e., plain and sprayed heated surfaces. These two surfaces were bisymmetrically set. Wall surface temperatures of both the fire and fluid sides were measured at three locations along the upward flow direction in each heated surface for determining the heat flux and heat transfer coefficient. Nickel-chromium and alumina were employed as the spray materials. The test results show that the sprayed surface can yield a marked elevation in the heat transfer performance due to boiling on the plain surface. Therefore the level of heated surface temperature is largely reduced by means of the spraying surface treatment. This implies that the spraying would much improve a corrosive condition of the heated surface.

  9. High-resolution X-ray absorption spectroscopy of iron carbonyl complexes.

    Science.gov (United States)

    Atkins, Andrew J; Bauer, Matthias; Jacob, Christoph R

    2015-06-07

    We apply high-energy-resolution fluorescence-detected (HERFD) X-ray absorption near-edge spectroscopy (XANES) to study iron carbonyl complexes. Mono-, bi-, and tri-nuclear carbonyl complexes and pure carbonyl complexes as well as carbonyl complexes containing hydrocarbon ligands are considered. The HERFD-XANES spectra reveal multiple pre-edge peaks with individual signatures for each complex, which could not be detected previously with conventional XANES spectroscopy. These peaks are assigned and analysed with the help of TD-DFT calculations. We demonstrate that the pre-edge peaks can be used to distinguish the different types of iron-iron interactions in carbonyl complexes. This opens up new possibilities for applying HERFD-XANES spectroscopy to probe the electronic structure of iron catalysts.

  10. Miniature High Stability High Temperature Space Rated Blackbody Radiance Source

    Science.gov (United States)

    Jones, J. A.; Beswick, A. G.

    1987-09-01

    This paper presents the design and test performance of a conical cavity type blackbody radiance source that will meet the requirements of the Halogen Occultation Experiment (HALOE) on the NASA Upper Atmospheric Research Satellite program (UARS). Since a radiance source meeting the requirements of this experiment was unavailable in the commercial market, a development effort was undertaken by the HALOE Project. The blackbody radiance source operates in vacuum at 1300 K + 0.5 K over any 15-minute interval, uses less than 7.5 watts of power, maintains a 49°C outer case temperature, and fits within the 2.5 x 2.5 x 3.0 inch envelope allocated inside the HALOE instrument. Also, the unit operates in air, during ground testing of the HALOE instrument, where it uses 17 watts of power with an outer case temperature of 66°C. The thrust of this design effort was to minimize the heat losses, in order to keep the power usage under 7.5 watts, and to minimize the amount of silica in the materials. Silica in the presence of the platinum heater winding used in this design would cause the platinum to erode, changing the operating temperature set-point. The design required the development of fabrication techniques which would provide very small, close tolerance parts from extremely difficult-to-machine materials. Also, a space rated ceramic core and unique, low thermal conductance, ceramic-to-metal joint was developed, tested and incorporated in this design. The completed flight qualification hardware has undergone performance, environmental and life testing. The design configuration and test results are discussed in detail in this paper.

  11. Cosensitization of D-A-π-A quinoxaline organic dye: efficiently filling the absorption valley with high photovoltaic efficiency.

    Science.gov (United States)

    Pei, Kai; Wu, Yongzhen; Li, Hui; Geng, Zhiyuan; Tian, He; Zhu, Wei-Hong

    2015-03-11

    In the efficient cosensitization, the pure organic sensitizers with high molecular extinction coefficients and long wavelength response are highly preferable since the dye loading amount for each dye in cosensitization is decreased with respect to single dye sensitization. A D-A-π-A featured quinoxaline organic sensitizer IQ21 is specifically designed. The high conjugation building block of 4H-cyclopenta[2,1-b:3,4-b']dithiophene (CPDT) is introduced as the π bridge, instead of the traditional thiophene unit, especially in realizing high molecular extinction coefficients (up to 66 600 M(-1) cm(-1)) and extending the light response wavelength. With respect to the reference dye IQ4, the slightly lower efficiency of IQ21 (9.03%) arises from the decrease of VOC, which offsets the gain in JSC. While cosensitized with a smaller D-π-A dye S2, the efficiency in IQ21 is further improved to 10.41% (JSC = 19.8 mA cm(-2), VOC = 731 mV, FF = 0.72). The large improvement in efficiency is attributed to the well-matched molecular structures and loading amounts of both dyes in the cosensitization system. We also demonstrated that coabsorbent dye S2 can distinctly compensate the inherent drawbacks of IQ21, not only enhancing the response intensity of IPCE, making up the absorption defects around low wavelength region of IPCE, but also repressing the charge recombination rate to some extent.

  12. Development of computerized dose planning system and applicator for high dose rate remote afterloading irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Choi, T. J. [Keimyung Univ., Taegu (Korea); Kim, S. W. [Fatima Hospital, Taegu (Korea); Kim, O. B.; Lee, H. J.; Won, C. H. [Keimyung Univ., Taegu (Korea); Yoon, S. M. [Dong-a Univ., Pusan (Korea)

    2000-04-01

    To design and fabricate of the high dose rate source and applicators which are tandem, ovoids and colpostat for OB/Gyn brachytherapy includes the computerized dose planning system. Designed the high dose rate Ir-192 source with nuclide atomic power irradiation and investigated the dose characteristics of fabricated brachysource. We performed the effect of self-absorption and determining the gamma constant and output factor and determined the apparent activity of designed source. he automated computer planning system provided the 2D distribution and 3D includes analysis programs. Created the high dose rate source Ir-192, 10 Ci(370GBq). The effective attenuation factor from the self-absorption and source wall was examined to 0.55 of the activity of bare source and this factor is useful for determination of the apparent activity and gamma constant 4.69 Rcm{sup 2}/mCi-hr. Fabricated the colpostat was investigated the dose distributions of frontal, axial and sagittal plane in intra-cavitary radiation therapy for cervical cancer. The reduce dose at bladder and rectum area was found about 20 % of original dose. The computerized brachytherapy planning system provides the 2-dimensional isodose and 3-D include the dose-volume histogram(DVH) with graphic-user-interface mode. emoted afterloading device was built for experiment of created Ir-192 source with film dosimetry within {+-}1 mm discrepancy. 34 refs., 25 figs., 11 tabs. (Author)

  13. Are high real interest rates bad for world economic growth?

    OpenAIRE

    1991-01-01

    There is a conventional perception that high real interest rates are bad for economic growth. However, the authors show that close examination of the experience over the last 40 years undermines the existence of such a relationship. For much of the 1950-79 period, expost real interest rates were less than the growth rate of income in the major economies, whereas the 1980s were a period of rapid growth in the world economy that coincided withunprecedentedly high real interest rates. The author...

  14. Power Absorption of High Frequency Electromagnetic Waves in a Partially Ionized Plasma Layer in Atmosphere Conditions

    Institute of Scientific and Technical Information of China (English)

    郭斌; 王晓钢

    2005-01-01

    We have studied the absorption, reflection, and transmission of electromagnetic waves in an unmagnetized uniform plasma layer covering a metal surface in atmosphere conditions.Instead of the absorption of the electromagnetic wave propagating only once in previous work on the plasma layer, a general formula of total power absorption by the plasma layer with an infinite time of reflections between the atmosphere-plasma interface and the metal surface has been derived for the first time. Effects of plasma parameters, especially the dependence of the fraction of positive ions, negative ions and electrons in plasmas on the power absorption processes are discussed. The results show that the existence of negative ions significantly reduces the power absorption of the electromagnetic wave. Absorptions of electromagnetic waves are calculated.

  15. High Strain Rate Compressive Tests on Woven Graphite Epoxy Composites

    Science.gov (United States)

    Allazadeh, Mohammad Reza; Wosu, Sylvanus N.

    2011-08-01

    The behavior of composite materials may be different when they are subjected to high strain rate load. Penetrating split Hopkinson pressure bar (P-SHPB) is a method to impose high strain rate on specimen in the laboratory experiments. This research work studied the response of the thin circular shape specimens, made out of woven graphite epoxy composites, to high strain rate impact load. The stress-strain relationships and behavior of the specimens were investigated during the compressive dynamic tests for strain rates as high as 3200 s-1. One dimensional analysis was deployed for analytical calculations since the experiments fulfilled the ratio of diameter to length of bars condition in impact load experiments. The mechanics of dynamic failure was studied and the results showed the factors which govern the failure mode in high strain deformation via absorbed energy by the specimen. In this paper, the relation of particle velocity with perforation depth was discussed for woven graphite epoxy specimens.

  16. Evaluation of in vitro release rate and in vivo absorption characteristics of four metoprolol tartrate immediate-release tablet formulations.

    Science.gov (United States)

    Rekhi, G S; Eddington, N D; Fossler, M J; Schwartz, P; Lesko, L J; Augsburger, L L

    1997-02-01

    The purpose of this investigation was to examine the impact of formulation and process changes on dissolution and bioavailability/bioequivalency of metoprolol tartrate tablets manufactured using a high-shear granulation process. A half-factorial (2(4-1), Res IV) design was undertaken to study the selected formulation and processing variables during scale-up. Levels and ranges for excipients and processing changes studied represented level 2 or greater changes as indicated by the SUPAC-IR Guidance. Blend and tableting properties were evaluated. Changes in sodium starch glycolate and magnesium stearate levels, and the order of addition microcrystalline cellulose (intra- vs. extragranular) were significant only in affecting percent drug released (Q) in 5, 10, and 15 min. Statistical analysis of data showed no significant curvature. No interaction effects were found to be statistically significant. To examine the impact of formulation and processing variables on in vivo absorption, three batches were selected for a bioavailability study based on their dissolution profiles. Subjects received four metoprolol treatments (Lopressor, slow-, medium-, and fast-dissolving formulations) separated by 1 week according to a randomized crossover design. After an overnight fast, subjects were administered one tablet (100 mg), blood samples were collected over 24 hr and plasma samples were analyzed. The formulations were found to be bioequivalent with respect to the log Cmax and log AUC0-infinity. The results of this study suggest that: (i) bioavailability/bioequivalency studies may not be necessary for metoprolol tartrate and perhaps other class 1 drugs after level 2 type changes and (ii) in vitro dissolution tests may be used to show bioequivalence of metoprolol formulations with processing or formulation changes within the specified level 2 ranges for the equipment examined.

  17. Quantum data locking for high-rate private communication

    Science.gov (United States)

    Lupo, Cosmo; Lloyd, Seth

    2015-03-01

    We show that, if the accessible information is used as a security quantifier, quantum channels with a certain symmetry can convey private messages at a tremendously high rate, as high as less than one bit below the rate of non-private classical communication. This result is obtained by exploiting the quantum data locking effect. The price to pay to achieve such a high private communication rate is that accessible information security is in general not composable. However, composable security holds against an eavesdropper who is forced to measure her share of the quantum system within a finite time after she gets it.

  18. Condition for unity absorption in an ultrathin and highly lossy film in a Gires-Tournois interferometer configuration.

    Science.gov (United States)

    Park, Junghyun; Kim, Soo Jin; Brongersma, Mark L

    2015-05-01

    We present a condition for unity absorption for a Gires-Tournois interferometer configuration constructed from an ultrathin and highly lossy film on top of metallic mirror. From the impedance matching condition in the transmission line theory, we identify a solution space for the required complex refractive index of the lossy film in various film thickness and dielectric constants of the metallic mirror. It is shown that strong absorption requires the imaginary part of the refractive index of the ultrathin lossy film be larger than 0.64, and the physical origin of this condition is elucidated. The proposed method is useful in identifying candidate semiconductor materials that can be used as the lossy film in a unity-absorption Gires-Tournois interferometer configuration and designing the thickness of this film to maximize absorption.

  19. Intensity dependent absorption bleaching of high subband excitons in GaAs/AlGaAs multiple quantum wells

    CERN Document Server

    Shin, S H; Lee, E H; Chae, K M; Park, S H; Kim, U

    1998-01-01

    We have investigated the influence of carrier generation on the absorption bleaching of the n=2 and n=3 excitons in GaAs/AlGaAs multiple quantum wells (MQWs). With the excitation near the resonance of the n=1 exciton absorption, the long range coulomb screening and collision broadening had significant effects on the exciton bleaching. At low excitation intensity, the absorption bleaching of the n=2 exciton in 75 A-thick MQWs and that of the n=3 exciton in 150 A-thick MQWs were due to linewidth broadening by the collision broadening effect only. At high excitation intensity, however, the reduction of oscillator strength due to the long range coulomb screening contributed dominantly to absorption bleaching.

  20. A High Galactic Latitude HI 21 cm-line Absorption Survey using the GMRT: I. Observations and Spectra

    Indian Academy of Sciences (India)

    Rekhesh Mohan; K. S. Dwarakanath; G. Srinivasan

    2004-09-01

    We have used the Giant Meterwave Radio Telescope (GMRT) to measure the Galactic HI 21-cm line absorption towards 102 extragalactic radio continuum sources, located at high (|| > 15°) Galactic latitudes. The Declination coverage of the present survey is ≳ -45°. With a mean rms optical depth of ∼ 0.003, this is the most sensitive Galactic HI 21-cm line absorption survey to date. To supplement the absorption data, we have extracted the HI 21-cm line emission profiles towards these 102 lines of sight from the Leiden Dwingeloo Survey of Galactic neutral hydrogen. We have carried out a Gaussian fitting analysis to identify the discrete absorption and emission components in these profiles. In this paper, we present the spectra and the components. A subsequent paper will discuss the interpretation of these results.

  1. Effectiveness of high interest rate policy on exchange rates: A reexamination of the Asian financial crisis

    Directory of Open Access Journals (Sweden)

    Chin Diew Lai

    2006-09-01

    Full Text Available One of the most controversial issues in the aftermath of the Asian financial crisis has been the appropriate response of monetary policy to a sharp decline in the value of some currencies. In this paper, we empirically examine the effects on Asian exchange rates of sharply higher interest rates during the Asian financial crisis. Taking account of the currency contagion effect, our results indicate that sharply higher interest rates helped to support the exchange rates of South Korea, the Philippines, and Thailand. For Malaysia, no significant causal relation is found from the rate of interest to exchange rates, as the authorities in Malaysia did not actively adopt a high interest rate policy to defend the currency.

  2. Highly Ionized Fe-K Absorption Line from Cygnus X-1 in the High/Soft State Observed with Suzaku

    CERN Document Server

    Yamada, S; Mineshige, S; Ueda, Y; Kubota, A; Gandhi, P; Done, C; Noda, H; Yoshikawa, A; Makishima, K

    2013-01-01

    We present observations of a transient He-like Fe K alpha absorption line in Suzaku observations of the black hole binary Cygnus X-1 on 2011 October 5 near superior conjunction during the high/soft state, which enable us to map the full evolution from the start and the end of the episodic accretion phenomena or dips for the first time. We model the X-ray spectra during the event and trace their evolution. The absorption line is rather weak in the first half of the observation, but instantly deepens for ~10 ks, and weakens thereafter. The overall change in equivalent width is a factor of ~3, peaking at an orbital phase of ~0.08. This is evidence that the companion stellar wind feeding the black hole is clumpy. By analyzing the line with a Voigt profile, it is found to be consistent with a slightly redshifted Fe XXV transition, or possibly a mixture of several species less ionized than Fe XXV. The data may be explained by a clump located at a distance of ~10^(10-12) cm with a density of ~10^((-13)-(-11)) g cm^-...

  3. Removal of high concentration CO2 from natural gas at elevated pressure via absorption process in packed column

    Institute of Scientific and Technical Information of China (English)

    L.S.Tan; K.K.Lau; M.A.Bustam; A.M.Shariff

    2012-01-01

    Carbon dioxide (CO2) removal is an essential step in natural gas (NG) processing to provide high quality gas stream products and minimize operational difficulties.This preliminary study aims to investigate the removal of CO2 at high concentration level from the mixture of CO2-NG gas stream at elevated pressure via absorption process.This is to explore the possibility of exploring high CO2 content natural gas reserves by treatment at offshore platform.A mixed amine solvent,Stonvent-Ⅱ,was used for the absorption of approximately 75 vol% CO2 in CO2-NG stream at a pressure of 10 barg.The initial solvent temperature was varied in order to study the impact of initial temperature on the absorption performance.Preliminary study at temperatures of 35 ℃ and 45 ℃ indicates that Stonvent-Ⅱ was able to perform almost 100% removal of CO2 under both conditions.However,the CO2 absorption effect took place faster when the initial liquid temperature was lower.This is because when the initial liquid temperature is high,the temperature increase in the packing bed caused by the reaction heat is high which impacts the efficiency of absorption negatively.

  4. Simultaneous high crystallinity and sub-bandgap optical absorptance in hyperdoped black silicon using nanosecond laser annealing

    Energy Technology Data Exchange (ETDEWEB)

    Franta, Benjamin, E-mail: bafranta@gmail.com; Pastor, David; Gandhi, Hemi H.; Aziz, Michael J.; Mazur, Eric [School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138 (United States); Rekemeyer, Paul H.; Gradečak, Silvija [Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

    2015-12-14

    Hyperdoped black silicon fabricated with femtosecond laser irradiation has attracted interest for applications in infrared photodetectors and intermediate band photovoltaics due to its sub-bandgap optical absorptance and light-trapping surface. However, hyperdoped black silicon typically has an amorphous and polyphasic polycrystalline surface that can interfere with carrier transport, electrical rectification, and intermediate band formation. Past studies have used thermal annealing to obtain high crystallinity in hyperdoped black silicon, but thermal annealing causes a deactivation of the sub-bandgap optical absorptance. In this study, nanosecond laser annealing is used to obtain high crystallinity and remove pressure-induced phases in hyperdoped black silicon while maintaining high sub-bandgap optical absorptance and a light-trapping surface morphology. Furthermore, it is shown that nanosecond laser annealing reactivates the sub-bandgap optical absorptance of hyperdoped black silicon after deactivation by thermal annealing. Thermal annealing and nanosecond laser annealing can be combined in sequence to fabricate hyperdoped black silicon that simultaneously shows high crystallinity, high above-bandgap and sub-bandgap absorptance, and a rectifying electrical homojunction. Such nanosecond laser annealing could potentially be applied to non-equilibrium material systems beyond hyperdoped black silicon.

  5. Putative extremely high rate of proteome innovation in lancelets might be explained by high rate of gene prediction errors.

    Science.gov (United States)

    Bányai, László; Patthy, László

    2016-08-01

    A recent analysis of the genomes of Chinese and Florida lancelets has concluded that the rate of creation of novel protein domain combinations is orders of magnitude greater in lancelets than in other metazoa and it was suggested that continuous activity of transposable elements in lancelets is responsible for this increased rate of protein innovation. Since morphologically Chinese and Florida lancelets are highly conserved, this finding would contradict the observation that high rates of protein innovation are usually associated with major evolutionary innovations. Here we show that the conclusion that the rate of proteome innovation is exceptionally high in lancelets may be unjustified: the differences observed in domain architectures of orthologous proteins of different amphioxus species probably reflect high rates of gene prediction errors rather than true innovation.

  6. X-ray Absorption Spectroscopic Studies of High-Spin Nonheme (Alkylperoxo)iron(III) Intermediates

    Energy Technology Data Exchange (ETDEWEB)

    Shan,X.; Rohde, J.; Koehntop, K.; Zhou, Y.; Bukowski, M.; Costas, M.; Fujisawa, K.; Que, Jr., L.

    2007-01-01

    The reactions of iron(II) complexes [Fe(Tpt-Bu,i-Pr)(OH)] (1a, Tpt-Bu,i-Pr = hydrotris(3-tert-butyl-5-isopropyl-1-pyrazolyl)borate), [Fe(6-Me2BPMCN)(OTf)2] (1b, 6-Me2BPMCN = N,N'-bis((2-methylpyridin-6-yl)methyl)-N,N'-dimethyl-trans-1,2-diaminocyclohexane), and [Fe(L8Py2)(OTf)](OTf) (1c, L8Py2 = 1,5-bis(pyridin-2-ylmethyl)-1,5-diazacyclooctane) with tert-BuOOH give rise to high-spin FeIII-OOR complexes. X-ray absorption spectra (XAS) of these high-spin species show characteristic features, distinct from those of low-spin Fe-OOR complexes. These include (1) an intense 1s {yields} 3d preedge feature, with an area around 20 units, (2) an edge energy, ranging from 7122 to 7126 eV, that is affected by the coordination environment, and (3) a 1.86-1.96 Angstroms Fe-OOR bond, compared to the 1.78 Angstroms Fe-OOR bond in low-spin complexes. These unique features likely arise from a flexible first coordination sphere in those complexes. The difference in Fe-OOR bond length may rationalize differences in reactivity between low-spin and high-spin FeIII-OOR species.

  7. Characterization of metalloproteins by high-throughput X-ray absorption spectroscopy.

    Science.gov (United States)

    Shi, Wuxian; Punta, Marco; Bohon, Jen; Sauder, J Michael; D'Mello, Rhijuta; Sullivan, Mike; Toomey, John; Abel, Don; Lippi, Marco; Passerini, Andrea; Frasconi, Paolo; Burley, Stephen K; Rost, Burkhard; Chance, Mark R

    2011-06-01

    High-throughput X-ray absorption spectroscopy was used to measure transition metal content based on quantitative detection of X-ray fluorescence signals for 3879 purified proteins from several hundred different protein families generated by the New York SGX Research Center for Structural Genomics. Approximately 9% of the proteins analyzed showed the presence of transition metal atoms (Zn, Cu, Ni, Co, Fe, or Mn) in stoichiometric amounts. The method is highly automated and highly reliable based on comparison of the results to crystal structure data derived from the same protein set. To leverage the experimental metalloprotein annotations, we used a sequence-based de novo prediction method, MetalDetector, to identify Cys and His residues that bind to transition metals for the redundancy reduced subset of 2411 sequences sharing metalloproteins to validate predicted metalloprotein binding site structures. This combination of experimental and bioinformatics approaches provides comprehensive active site analysis on the genome scale for metalloproteins as a class, revealing new insights into metalloprotein structure and function.

  8. High Burn Rate Hybrid Fuel for Improved Grain Design Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A novel type of fuel providing high burning rate for hybrid rocket applications is proposed. This fuel maintains a hydrodynamically rough surface to...

  9. High Count Rate Single Photon Counting Detector Array Project

    Data.gov (United States)

    National Aeronautics and Space Administration — An optical communications receiver requires efficient and high-rate photon-counting capability so that the information from every photon, received at the aperture,...

  10. Remote measurement of high preeruptive water vapor emissions at Sabancaya volcano by passive differential optical absorption spectroscopy

    Science.gov (United States)

    Kern, Christoph; Masias, Pablo; Apaza, Fredy; Reath, Kevin; Platt, Ulrich

    2017-01-01

    Water (H2O) is by far the most abundant volcanic volatile species and plays a predominant role in driving volcanic eruptions. However, numerous difficulties associated with making accurate measurements of water vapor in volcanic plumes have limited their use as a diagnostic tool. Here we present the first detection of water vapor in a volcanic plume using passive visible-light differential optical absorption spectroscopy (DOAS). Ultraviolet and visible-light DOAS measurements were made on 21 May 2016 at Sabancaya Volcano, Peru. We find that Sabancaya's plume contained an exceptionally high relative water vapor abundance 6 months prior to its November 2016 eruption. Our measurements yielded average sulfur dioxide (SO2) emission rates of 800–900 t/d, H2O emission rates of around 250,000 t/d, and an H2O/SO2 molecular ratio of 1000 which is about an order of magnitude larger than typically found in high-temperature volcanic gases. We attribute the high water vapor emissions to a boiling-off of Sabancaya's hydrothermal system caused by intrusion of magma to shallow depths. This hypothesis is supported by a significant increase in the thermal output of the volcanic edifice detected in infrared satellite imagery leading up to and after our measurements. Though the measurement conditions encountered at Sabancaya were very favorable for our experiment, we show that visible-light DOAS systems could be used to measure water vapor emissions at numerous other high-elevation volcanoes. Such measurements would provide observatories with additional information particularly useful for forecasting eruptions at volcanoes harboring significant hydrothermal systems.

  11. High Repetition Rate Pulsed 2-Micron Laser Transmitter for Coherent CO2 DIAL Measurement

    Science.gov (United States)

    Singh, Uprendra N.; Bai, Yingxin; Yu, Jirong; Petros, Mulugeta; Petzar, Paul J.; Trieu, Bo C.; Lee, Hyung

    2009-01-01

    A high repetition rate, highly efficient, Q-switched 2-micron laser system as the transmitter of a coherent differential absorption lidar for CO2 measurement has been developed at NASA Langley Research Center. Such a laser transmitter is a master-slave laser system. The master laser operates in a single frequency, either on-line or off-line of a selected CO2 absorption line. The slave laser is a Q-switched ring-cavity Ho:YLF laser which is pumped by a Tm:fiber laser. The repetition rate can be adjusted from a few hundred Hz to 10 kHz. The injection seeding success rate is from 99.4% to 99.95%. For 1 kHz operation, the output pulse energy is 5.5mJ with the pulse length of approximately 50 ns. The optical-to-optical efficiency is 39% when the pump power is 14.5W. The measured standard deviation of the laser frequency jitter is about 3 MHz.

  12. Quantum Communication with a High-Rate Entangled Photon Source

    Science.gov (United States)

    Wilson, Nathaniel C.; Chaffee, Dalton W.; Lekki, John D.; Wilson, Jeffrey D.

    2016-01-01

    A high generation rate photon-pair source using a dual element periodically-poled potassium titanyl phosphate (PP KTP) waveguide is described. The photon-pair source features a high pair generation rate, a compact power-efficient package, and continuous wave (CW) or pulsed operation. Characterization and test results are presented. Details and preliminary results of a laboratory free-space QKD experiment with the B92 protocol are also presented.

  13. High rate resistive plate chamber for LHC detector upgrades

    Energy Technology Data Exchange (ETDEWEB)

    Haddad, Y., E-mail: haddad@llr.in2p3.fr [Laboratoire Leprince-Ringuet (LLR), École Polytechnique, 91120 Palaiseau (France); Laktineh, I.; Grenier, G.; Lumb, N. [IPNL, Villeurbanne 69622 Lyon (France); Cauwenbergh, S. [Ghent University, Ghent (Belgium)

    2013-08-01

    The limitation of the detection rate of standard bakelite resistive plate chambers (RPCs) used as muon detectors in the LHC experiments has prevented the use of such detectors in the high rate regions in both CMS and ATLAS detectors. One alternative to these detectors is RPCs made with low resistivity glass plates (10{sup 10}Ωcm), a beam test at DESY has shown that such detectors can operate at few thousand Hz/cm{sup 2} with high efficiency (>90%)

  14. A deep search for 21-cm absorption in high redshift damped Lyman-alpha systems

    NARCIS (Netherlands)

    Kanekar, N; Chengalur, JN

    2003-01-01

    We present deep GMRT 21-cm absorption spectra of 10 damped Lyman-alpha systems (DLAs), of which 8 are at redshifts zgreater than or similar to1.3. HI absorption was detected in only one DLA, the z=0.5318 absorber toward PKS 1629+12. This absorber has been identified with a luminous spiral galaxy; th

  15. Effects of Bicarbonate and High pH Conditions on Zinc and Other Nutrients Absorption in Rice

    Institute of Scientific and Technical Information of China (English)

    LU Zhong-xian; MENG Fan-hua; S. VILLAREAL; WEI You-zhang; YU Xiao-ping; YANG Xiao-e; K. L. HEONG; LIN Jian-jun; HU Cui; LIU Jian-xiang

    2004-01-01

    Zinc deficiency was widely observed in calcareous soil where bicarbonate and high pH were always related with low zinc availability. In a hydroponic experiment, one zinc-efficient rice (IR36) and one zinc-inefficient rice (IR26) genotypes were employed to investigate the effects of bicarbonate and high pH conditions on absorption, transport of zinc and other nutrients (P, K, Ca, Mg,Fe, Cu, Mn) in rice. As compared with the control, high pH inhibited absorption, translocation and accumulation of zinc and other nutrients in both rice genotypes. Bicarbonate had minor effect on zinc-efficient rice genotype (IR36) whereas it could decrease zinc and other nutrient absorption in zinc-inefficient rice genotype (IR26). These results implied that increasing rice tolerance to bicarbonate is one of the most important strategies to improve rice adaptation for zinc-deficit calcareous soil.

  16. Investigations for effect of Al2O3–H2O nanofluid flow rate on the efficiency of direct absorption solar collector

    Directory of Open Access Journals (Sweden)

    Hemant Kumar Gupta

    2015-03-01

    Full Text Available The efficiency of conventional tube‐ in plate type solar collectors is limited due to higher heat losses for surface based solar energy absorption and indirect transfer of heat from hot absorber surface to working fluid having poor heat transfer properties flowing through tubes. In this paper, a prototype direct absorption solar collector having gross area 1.4 m2 working on volumetric absorption principle is developed to investigate the effect of using Al2O3–H2O nanofluid as heat transfer fluid at different flow rates. Experimentation was carried using distilled water and 0.005% volume fractions of 20 nm size Al2O3 nanoparticles at three flow rates of 1.5, 2 and 2.5 lpm. ASHRAE standard 93-86 was followed for calculation of instantaneous efficiency of solar collector. Use of nanofluid improves the optical and thermo physical properties that result into an increase in the efficiency of the collector in all cases of using nanofluids in place of water. Collector efficiency enhancement of 8.1% and 4.2% has been observed for 1.5 and 2 lpm flow rate of nanofluid respectively. Optimum flow rate of 2.5 and 2 lpm towards maximum collector efficiency have also been observed for water and nanofluid respectively.

  17. High-temperature measurements of methane and acetylene using quantum cascade laser absorption near 8μm

    KAUST Repository

    Sajid, M.B.

    2015-04-01

    The mid-infrared wavelength region near 8 mu m contains absorption bands of several molecules such as water vapor, hydrogen peroxide, nitrous oxide, methane and acetylene. A new laser absorption sensor based on the v(4) band of methane and the v(4)+v(5) band of acetylene is reported for interference-free, time-resolved measurements under combustion-relevant conditions. A detailed line-selection procedure was used to identify optimum transitions. Methane and acetylene were measured at the line centers of Q12 (1303.5 cm(-1)) and P23 (1275.5 cm(-1)) transitions, respectively. High-temperature absorption cross sections of methane and acetylene were measured at peaks (on-line) and valleys (off-line) of the selected absorption transitions. The differential absorption strategy was employed to eliminate interference absorption from large hydrocarbons. Experiments were performed behind reflected shock waves over a temperature range of 1200-2200 K, between pressures of 1-4 atm. The diagnostics were then applied to measure the respective species time-history profiles during the shock-heated pyrolysis of n-pentane. (C) 2015 Elsevier Ltd. All rights reserved.

  18. High-energy irradiation and mass loss rates of hot Jupiters in the solar neighborhood

    CERN Document Server

    Salz, M; Czesla, S; Schmitt, J H M M

    2015-01-01

    Giant gas planets in close proximity to their host stars experience strong irradiation. In extreme cases photoevaporation causes a transonic, planetary wind and the persistent mass loss can possibly affect the planetary evolution. We have identified nine hot Jupiter systems in the vicinity of the Sun, in which expanded planetary atmospheres should be detectable through Lyman alpha transit spectroscopy according to predictions. We use X-ray observations with Chandra and XMM-Newton of seven of these targets to derive the high-energy irradiation level of the planetary atmospheres and the resulting mass loss rates. We further derive improved Lyman alpha luminosity estimates for the host stars including interstellar absorption. According to our estimates WASP-80 b, WASP-77 b, and WASP-43 b experience the strongest mass loss rates, exceeding the mass loss rate of HD 209458 b, where an expanded atmosphere has been confirmed. Furthermore, seven out of nine targets might be amenable to Lyman alpha transit spectroscopy...

  19. High strain rate loading of polymeric foams and solid plastics

    Science.gov (United States)

    Dick, Richard D.; Chang, Peter C.; Fourney, William L.

    2000-04-01

    The split-Hopkinson pressure bar (SHPB) provided a technique to determine the high strain rate response for low density foams and solid ABS and polypropylene plastics. These materials are used in the interior safety panels of automobiles and crash test dummies. Because the foams have a very low impedance, polycarbonate bars were used to acquire the strain rate data in the 100 to 1600 l/s range. An aluminum SPHB setup was used to obtain the solid plastics data which covered strain rates of 1000 to 4000 l/s. The curves for peak strain rate versus peak stress for the foams over the test range studied indicates only a slight strain rate dependence. Peak strain rate versus peak stress curves for polypropylene shows a strain rate dependence up to about 1500 l/s. At that rate the solid poly propylene indicates no strain rate dependence. The ABS plastics are strain rate dependent up to 3500 l/s and then are independent at larger strain rates.

  20. HIGH HEATING RATES AFFECTS GREATLY THE INACTIVATION RATE OF ESCHERICHIA COLI

    Directory of Open Access Journals (Sweden)

    Juan Pablo Huertas

    2016-08-01

    Full Text Available Heat resistance of microorganisms can be affected by different influencing factors. Although the effect of heating rates has been scarcely explored by the scientific community, recent researches have unraveled its important effect on the thermal resistance of different species of vegetative bacteria. Typically heating rates described in the literature ranged from 1 to 20ºC/min but the impact of much higher heating rates is unclear. The aim of this research was to explore the effect of different heating rates, such as those currently achieved in the heat exchangers used in the food industry, on the heat resistance of Escherichia coli. A pilot plant tubular heat exchanger and a thermoresistometer Mastia were used for this purpose. Results showed that fast heating rates had a deep impact on the thermal resistance of E. coli. Heating rates between 20 and 50ºC/min were achieved in the heat exchanger, which were much slower than those around 20ºC/s achieved in the thermoresistometer. In all cases, these high heating rates led to higher inactivation than expected: in the heat exchanger, for all the experiments performed, when the observed inactivation had reached about seven log cycles, the predictions estimates about 1 log cycle of inactivation; in the thermoresistometer these differences between observed and predicted values were even more than ten times higher, from 4.07 log cycles observed to 0.34 predicted at a flow rate of 70 mL/min and a maximum heating rate of 14.7ºC/s. A quantification of the impact of the heating rates on the level of inactivation achieved was established. These results point out the important effect that the heating rate has on the thermal resistance of E. coli, with high heating rates resulting in an additional sensitization to heat and therefore an effective food safety strategy in terms of food processing.

  1. High Heating Rates Affect Greatly the Inactivation Rate of Escherichia coli

    Science.gov (United States)

    Huertas, Juan-Pablo; Aznar, Arantxa; Esnoz, Arturo; Fernández, Pablo S.; Iguaz, Asunción; Periago, Paula M.; Palop, Alfredo

    2016-01-01

    Heat resistance of microorganisms can be affected by different influencing factors. Although, the effect of heating rates has been scarcely explored by the scientific community, recent researches have unraveled its important effect on the thermal resistance of different species of vegetative bacteria. Typically heating rates described in the literature ranged from 1 to 20°C/min but the impact of much higher heating rates is unclear. The aim of this research was to explore the effect of different heating rates, such as those currently achieved in the heat exchangers used in the food industry, on the heat resistance of Escherichia coli. A pilot plant tubular heat exchanger and a thermoresistometer Mastia were used for this purpose. Results showed that fast heating rates had a deep impact on the thermal resistance of E. coli. Heating rates between 20 and 50°C/min were achieved in the heat exchanger, which were much slower than those around 20°C/s achieved in the thermoresistometer. In all cases, these high heating rates led to higher inactivation than expected: in the heat exchanger, for all the experiments performed, when the observed inactivation had reached about seven log cycles, the predictions estimated about 1 log cycle of inactivation; in the thermoresistometer these differences between observed and predicted values were even more than 10 times higher, from 4.07 log cycles observed to 0.34 predicted at a flow rate of 70 mL/min and a maximum heating rate of 14.7°C/s. A quantification of the impact of the heating rates on the level of inactivation achieved was established. These results point out the important effect that the heating rate has on the thermal resistance of E. coli, with high heating rates resulting in an additional sensitization to heat and therefore an effective food safety strategy in terms of food processing. PMID:27563300

  2. A High Galactic Latitude HI 21 cm-line Absorption Survey using the GMRT: II. Results and Interpretation

    Indian Academy of Sciences (India)

    Rekhesh Mohan; K. S. Dwarakanath; G. Srinivasan

    2004-09-01

    We have carried out a sensitive high-latitude (|| > 15°) HI 21 cm-line absorption survey towards 102 sources using the GMRT. With a 3 detection limit in optical depth of ∼ 0.01, this is the most sensitive HI absorption survey. We detected 126 absorption features most of which also have corresponding HI emission features in the Leiden Dwingeloo Survey of Galactic neutral Hydrogen. The histogram of random velocities of the absorption features is well-fit by two Gaussians centered at lsr ∼ 0 km s−1 with velocity dispersions of 7.6 ± 0.3 km s-1 and 21 ± 4 km s-1 respectively. About 20% of the HI absorption features form the larger velocity dispersion component. The HI absorption features forming the narrow Gaussian have a mean optical depth of 0.20 ± 0.19, a mean HI column density of (1.46 ± 1.03) × 1020 cm-2, and a mean spin temperature of 121 ± 69 K. These HI concentrations can be identified with the standard HI clouds in the cold neutral medium of the Galaxy. The HI absorption features forming the wider Gaussian have a mean optical depth of 0.04 ± 0.02, a mean HI column density of (4.3 ± 3.4)× 1019 cm-2, and a mean spin temperature of 125 ± 82 K. The HI column densities of these fast clouds decrease with their increasing random velocities. These fast clouds can be identified with a population of clouds detected so far only in optical absorption and in HI emission lines with a similar velocity dispersion. This population of fast clouds is likely to be in the lower Galactic Halo.

  3. Radio Interface for High Data Rate Wireless Sensor Networks

    CERN Document Server

    Henaut, Julien; Dragomirescu, Daniela; Plana, Robert

    2010-01-01

    This paper gives an overview of radio interfaces devoted for high data rate Wireless Sensor Networks. Four aerospace applications of WSN are presented to underline the importance of achieving high data rate. Then, two modulation schemes by which High Data Rate can be achieved are compared : Multi carrier approaches, represented by the popular Orthogonal Frequency Division Multiplexing (OFDM) and Single carrier methods, represented by Single Carrier Frequency division Equalization and its application for multiple access Single Carrier Frequency division multiple Access (SC-FDMA). SC-FDMA, with a very low Peak Average Power Ratio (PAPR), is as strong alternative to the OFDM scheme for highly power constraint application. The Chosen radio interface will be, finally, tested by a model based design approach based on Simulink and FPGA realization. SC-FDMA, with a very low Peak Average Power Ratio (PAPR), is as strong alternative to the OFDM scheme for highly power constraint application. The Chosen radio interface ...

  4. Hybrid solar receiver as a source of high-temperature medium for an absorption chiller supply

    Science.gov (United States)

    Przenzak, Estera; Filipowicz, Mariusz

    2016-03-01

    This article discusses the problems related with the cold production, i.e. energy efficiency of the process. The idea of solar cooling systems has been presented as the solution of the problem of big electricity demand. The paper discusses the principle of the operation of absorption chillers. Disadvantages and advantages of the solar cooling systems were discussed. The installation for manufacturing high-temperature heat based on solar collectors and concentrator of solar radiation constructed in AGH in Cracow has been presented. This installation is a first stage of projected, complete solar cooling system. The special attention is paid to the dedicated solar high-temperature heat receiver as a most important element of the system. The achieved values of temperature, power and efficiency depending on the working medium flow has been presented and discussed. The intensity of solar radiation during the measurements has been taken into account. Two versions of heat receiver were investigated: non-insulated and insulated with mineral wool. The obtained efficiency of the heat receiver (less than 30%) is not satisfactory but possibility of improvements exist.

  5. High-resolution IUE observations of interstellar absorption lines in the Vela supernova remnant

    Science.gov (United States)

    Jenkins, E. B.; Wallerstein, G.; Silk, J.

    1984-01-01

    Ultraviolet spectra of 45 stars in the vicinity of the Vela supernova remnant were recorded by the short-wavelength echelle spectrograph aboard the International Ultraviolet Explorer (IUE). Over one-third of the stars show interstellar absorption lines at large radial velocities (greater than 60 km/s). The mapping of these high-velocity components in the sky suggests the motions are chaotic, rather than from a coherent expansion of the remnant material. In accord with earlier conclusions from Copernicus data, the gas at high velocity exhibits higher than normal ionization and shows substantially less depletion of nonvolatile elements than normal interstellar material at low velocities. Relatively strong lines from neutral carbon in the two excited fine-structure states indicate that the neutral clouds within the remnant have had their pressures enhanced by the passage of the blast wave from the supernova. Also, the remnant seems to show a significant enhancement in the abundances of low-velocity Si IV, C IV, and N V over those found in the general interstellar medium.

  6. Hybrid solar receiver as a source of high-temperature medium for an absorption chiller supply

    Directory of Open Access Journals (Sweden)

    Przenzak Estera

    2016-01-01

    Full Text Available This article discusses the problems related with the cold production, i.e. energy efficiency of the process. The idea of solar cooling systems has been presented as the solution of the problem of big electricity demand. The paper discusses the principle of the operation of absorption chillers. Disadvantages and advantages of the solar cooling systems were discussed. The installation for manufacturing high-temperature heat based on solar collectors and concentrator of solar radiation constructed in AGH in Cracow has been presented. This installation is a first stage of projected, complete solar cooling system. The special attention is paid to the dedicated solar high-temperature heat receiver as a most important element of the system. The achieved values of temperature, power and efficiency depending on the working medium flow has been presented and discussed. The intensity of solar radiation during the measurements has been taken into account. Two versions of heat receiver were investigated: non-insulated and insulated with mineral wool. The obtained efficiency of the heat receiver (less than 30% is not satisfactory but possibility of improvements exist.

  7. [Study on cadmium absorption in pumpkin by atomic absorption spectrophotometry].

    Science.gov (United States)

    Li, Zhen-Xia; Jing, Rui-Jun; Dong, Wei-Hua; Li, Xin-Zheng; Liu, Hong

    2006-08-01

    A study was carried out on the characteristic of cadmium absorption in pumpkin by atomic absorption spectrophotometer. The results show that the cadmium absorption amount in pumpkin increased with the increase in cadmium concentration. Meanwhile the cadmium absorption amount in pumpkin increased with time. Eight hours after being cultured in the liquid, the cadmium absorption amount became saturated. The cadmium absorption rate reached the peak after 2 hours, then the absorption rate gradually reduced. The cadmium absorption amount in pumpkin is less in acid or alkali compared with neutral condition. And the absorption amount became minimum in pH 3, while maximum in pH 7.

  8. Stretching Behavior of Red Blood Cells at High Strain Rates

    Science.gov (United States)

    Mancuso, Jordan; Ristenpart, William

    2016-11-01

    Most work on the mechanical behavior of red blood cells (RBCs) has focused on simple shear flows. Relatively little work has examined RBC deformations in the physiologically important extensional flow that occurs at the entrance to a constriction. In particular, previous work suggests that RBCs rapidly stretch out and then retract upon entering the constriction, but to date no model predicts this behavior for the extremely high strain rates typically experienced there. In this work, we use high speed video to perform systematic measurements of the dynamic stretching behavior of RBCs as they enter a microfluidic constriction. We demonstrate that a simple viscoelastic model captures the observed stretching dynamics, up to strain rates as high as 1000 s-1. The results indicate that the effective elastic modulus of the RBC membrane at these strain rates is an order of magnitude larger than moduli measured by micropipette aspiration or other low strain rate techniques.

  9. Solidification at the High and Low Rate Extreme

    Energy Technology Data Exchange (ETDEWEB)

    Meco, Halim [Iowa State Univ., Ames, IA (United States)

    2004-12-19

    The microstructures formed upon solidification are strongly influenced by the imposed growth rates on an alloy system. Depending on the characteristics of the solidification process, a wide range of growth rates is accessible. The prevailing solidification mechanisms, and thus the final microstructure of the alloy, are governed by these imposed growth rates. At the high rate extreme, for instance, one can have access to novel microstructures that are unattainable at low growth rates. While the low growth rates can be utilized for the study of the intrinsic growth behavior of a certain phase growing from the melt. Although the length scales associated with certain processes, such as capillarity, and the diffusion of heat and solute, are different at low and high rate extremes, the phenomena that govern the selection of a certain microstructural length scale or a growth mode are the same. Consequently, one can analyze the solidification phenomena at both high and low rates by using the same governing principles. In this study, we examined the microstructural control at both low and high extremes. For the high rate extreme, the formation of crystalline products and factors that control the microstructure during rapid solidification by free-jet melt spinning are examined in Fe-Si-B system. Particular attention was given to the behavior of the melt pool at different quench-wheel speeds. Since the solidification process takes place within the melt-pool that forms on the rotating quench-wheel, we examined the influence of melt-pool dynamics on nucleation and growth of crystalline solidification products and glass formation. High-speed imaging of the melt-pool, analysis of ribbon microstructure, and measurement of ribbon geometry and surface character all indicate upper and lower limits for melt-spinning rates for which nucleation can be avoided, and fully amorphous ribbons can be achieved. Comparison of the relevant time scales reveals that surface-controlled melt

  10. Proportion-corrected scaled voxel models for Japanese children and their application to the numerical dosimetry of specific absorption rate for frequencies from 30 MHz to 3 GHz

    Science.gov (United States)

    Nagaoka, Tomoaki; Kunieda, Etsuo; Watanabe, Soichi

    2008-12-01

    The development of high-resolution anatomical voxel models of children is difficult given, inter alia, the ethical limitations on subjecting children to medical imaging. We instead used an existing voxel model of a Japanese adult and three-dimensional deformation to develop three voxel models that match the average body proportions of Japanese children at 3, 5 and 7 years old. The adult model was deformed to match the proportions of a child by using the measured dimensions of various body parts of children at 3, 5 and 7 years old and a free-form deformation technique. The three developed models represent average-size Japanese children of the respective ages. They consist of cubic voxels (2 mm on each side) and are segmented into 51 tissues and organs. We calculated the whole-body-averaged specific absorption rates (WBA-SARs) and tissue-averaged SARs for the child models for exposures to plane waves from 30 MHz to 3 GHz; these results were then compared with those for scaled down adult models. We also determined the incident electric-field strength required to produce the exposure equivalent to the ICNIRP basic restriction for general public exposure, i.e., a WBA-SAR of 0.08 W kg-1.

  11. High purity polyimide analysis by solid sampling graphite furnace atomic absorption spectrometry

    Science.gov (United States)

    Santos, Rafael F.; Carvalho, Gabriel S.; Duarte, Fabio A.; Bolzan, Rodrigo C.; Flores, Erico M. M.

    2017-03-01

    In this work, Cr, Cu, Mn, Na and Ni were determined in high purity polyimides (99.5%) by solid sampling graphite furnace atomic absorption spectrometry (SS-GFAAS) using Zeeman effect background correction system with variable magnetic field, making possible the simultaneous measurement at high or low sensitivity. The following analytical parameters were evaluated: pyrolysis and atomization temperatures, feasibility of calibration with aqueous solution, linear calibration range, sample mass range and the use of chemical modifier. Calibration with aqueous standard solutions was feasible for all analytes. No under or overestimated results were observed and up to 10 mg sample could be introduced on the platform for the determination of Cr, Cu, Mn, Na and Ni. The relative standard deviation ranged from 3 to 20%. The limits of detection (LODs) achieved using the high sensitivity mode were as low as 7.0, 2.5, 1.7, 17 and 0.12 ng g- 1 for Cr, Cu, Mn, Na and Ni, respectively. No addition of chemical modifier was necessary, except for Mn determination where Pd was required. The accuracy was evaluated by analyte spike and by comparison of the results with those obtained by inductively coupled plasma optical emission spectrometry and inductively coupled plasma mass spectrometry after microwave-assisted digestion in a single reaction chamber system and also by neutron activation analysis. No difference among the results obtained by SS-GFAAS and those obtained by alternative analytical methods using independent techniques. SS-GFAAS method showed some advantages, such as the determination of metallic contaminants in high purity polyimides with practically no sample preparation, very low LODs, calibration with aqueous standards and determination in a wide range of concentration.

  12. High sensitivity ultra-broad-band absorption spectroscopy of inductively coupled chlorine plasma

    Science.gov (United States)

    Marinov, Daniil; Foucher, Mickaël; Campbell, Ewen; Brouard, Mark; Chabert, Pascal; Booth, Jean-Paul

    2016-06-01

    We propose a method to measure the densities of vibrationally excited Cl2(v) molecules in levels up to v  =  3 in pure chlorine inductively coupled plasmas (ICPs). The absorption continuum of Cl2 in the 250-450 nm spectral range is deconvoluted into the individual components originating from the different vibrational levels of the ground state, using a set of ab initio absorption cross sections. It is shown that gas heating at constant pressure is the major depletion mechanism of the Cl2 feedstock in the plasma. In these line-integrated absorption measurements, the absorption by the hot (and therefore rarefied) Cl2 gas in the reactor centre is masked by the cooler (and therefore denser) Cl2 near the walls. These radial gradients in temperature and density make it difficult to assess the degree of vibrational excitation in the centre of the reactor. The observed line-averaged vibrational distributions, when analyzed taking into account the radial temperature gradient, suggest that vibrational and translational degrees of freedom in the plasma are close to local equilibrium. This can be explained by efficient vibrational-translational (VT) relaxation between Cl2 and Cl atoms. Besides the Cl2(v) absorption band, a weak continuum absorption is observed at shorter wavelengths, and is attributed to photodetachment of Cl- negative ions. Thus, line-integrated densities of negative ions in chlorine plasmas can be directly measured using broad-band absorption spectroscopy.

  13. High deposition rate nanocrystalline silicon with enhanced homogeneity

    NARCIS (Netherlands)

    Verkerk, A.; Rath, J.K.; Schropp, R.E.I.

    2010-01-01

    High rate growth of hydrogenated nanocrystalline silicon (nc-Si:H) brings additional challenges for the homogeneity in the growth direction, since the start-up effects affect a larger portion of the film, and the very high degree of depletion increases the influence of back diffusion from the inacti

  14. Ultraviolet-visible absorption spectra of solid hydrogen sulphide under high pressure

    CERN Document Server

    Kume, T; Sasaki, S; Shimizu, H

    2002-01-01

    Ultraviolet-visible absorption spectra of solid hydrogen sulphide (H sub 2 S) were measured at various pressures from 0.3 to 29 GPa. The absorption edge observed around 4.8 eV at 0.3 GPa indicated a red-shift with increasing pressure, and positioned below 3 eV at 29 GPa. On the basis of the spectra obtained, the energy gap was determined as a function of pressure. The transition to phase IV at 11 GPa was found to lead to a small jump in its pressure dependence and to yield an Urbach tail in the absorption edge.

  15. The studies of high-frequency magnetic properties and absorption characteristics for amorphous-filler composites

    Science.gov (United States)

    Li, Z. W.; Yang, Z. H.

    2015-10-01

    Pure amorphous flake fillers and amorphous flakes coated by ferrite nanoparticles with core-shell-like structure were fabricated using mechanical ball-milling. The later with core-shell-like structure can greatly decrease permittivity and improve the absorption properties, as compared to the former. The absorption of all amorphous-filler composites has its origin in a quarter-wavelength resonator. Based on the resonator model, absorption frequency fA and the corresponding return loss RL are calculated, which are well consistent with observed values. It is also found that the resonance frequency is proportional to effective resistivity, based on William-Shockley-Kittel's eddy model.

  16. High-resolution IR absorption spectroscopy of polycyclic aromatic hydrocarbons in the 3 {\\mu}m region: Role of periphery

    CERN Document Server

    Maltseva, Elena; Candian, Alessandra; Mackie, Cameron J; Huang, Xinchuan; Lee, Timothy J; Tielens, Alexander G G M; Buma, Wybren Jan

    2016-01-01

    In this work we report on high-resolution IR absorption studies that provide a detailed view on how the peripheral structure of irregular polycyclic aromatic hydrocarbons (PAHs) affects the shape and position of their 3 {\\mu}m absorption band. To this purpose we present mass-selected, high-resolution absorption spectra of cold and isolated phenanthrene, pyrene, benz[a]antracene, chrysene, triphenylene, and perylene molecules in the 2950-3150 cm-1 range. The experimental spectra are compared with standard harmonic calculations, and anharmonic calculations using a modified version of the SPECTRO program that incorporates a Fermi resonance treatment utilizing intensity redistribution. We show that the 3 {\\mu}m region is dominated by the effects of anharmonicity, resulting in many more bands than would have been expected in a purely harmonic approximation. Importantly, we find that anharmonic spectra as calculated by SPECTRO are in good agreement with the experimental spectra. Together with previously reported hi...

  17. High-rate squeezing process of bulk metallic glasses

    Science.gov (United States)

    Fan, Jitang

    2017-03-01

    High-rate squeezing process of bulk metallic glasses from a cylinder into an intact sheet achieved by impact loading is investigated. Such a large deformation is caused by plastic flow, accompanied with geometrical confinement, shear banding/slipping, thermo softening, melting and joining. Temperature rise during the high-rate squeezing process makes a main effect. The inherent mechanisms are illustrated. Like high-pressure torsion (HPT), equal channel angular pressing (ECAP) and surface mechanical attrition treatments (SMAT) for refining grain of metals, High-Rate Squeezing (HRS), as a multiple-functions technique, not only creates a new road of processing metallic glasses and other metallic alloys for developing advanced materials, but also directs a novel technology of processing, grain refining, coating, welding and so on for treating materials.

  18. High power, high efficiency millimeter wavelength traveling wave tubes for high rate communications from deep space

    Science.gov (United States)

    Dayton, James A., Jr.

    1991-01-01

    The high-power transmitters needed for high data rate communications from deep space will require a new class of compact, high efficiency traveling wave tubes (TWT's). Many of the recent TWT developments in the microwave frequency range are generically applicable to mm wave devices, in particular much of the technology of computer aided design, cathodes, and multistage depressed collectors. However, because TWT dimensions scale approximately with wavelength, mm wave devices will be physically much smaller with inherently more stringent fabrication tolerances and sensitivity to thermal dissipation.

  19. HIGHLY IONIZED Fe-K ABSORPTION LINE FROM CYGNUS X-1 IN THE HIGH/SOFT STATE OBSERVED WITH SUZAKU

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, S.; Yoshikawa, A.; Makishima, K. [Cosmic Radiation Laboratory, Institute of Physical and Chemical Research (RIKEN), Wako, Saitama 351-0198 (Japan); Torii, S.; Noda, H. [Department of Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Mineshige, S. [Department of Astronomy, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto 606-8502 (Japan); Ueda, Y. [Department of Physics, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto 606-8502 (Japan); Kubota, A. [Department of Electronic Information Systems, Shibaura Institute of Technology, 307 Fukasaku, Minuma-ku, Saitama-shi, Saitama 337-8570 (Japan); Gandhi, P. [Institute of Space and Astronautical Science, JAXA, 3-1-1 Yoshinodai, Sagamiharas, 229-8510 Kanagawa (Japan); Done, C. [Department of Physics, Durham University, South Road, Durham DH1 3LE (United Kingdom)

    2013-04-20

    We present observations of a transient He-like Fe K{alpha} absorption line in Suzaku observations of the black hole binary Cygnus X-1 on 2011 October 5 near superior conjunction during the high/soft state, which enable us to map the full evolution from the start to the end of the episodic accretion phenomena or dips for the first time. We model the X-ray spectra during the event and trace their evolution. The absorption line is rather weak in the first half of the observation, but instantly deepens for {approx}10 ks, and weakens thereafter. The overall change in equivalent width is a factor of {approx}3, peaking at an orbital phase of {approx}0.08. This is evidence that the companion stellar wind feeding the black hole is clumpy. By analyzing the line with a Voigt profile, it is found to be consistent with a slightly redshifted Fe XXV transition, or possibly a mixture of several species less ionized than Fe XXV. The data may be explained by a clump located at a distance of {approx}10{sup 10-12} cm with a density of {approx}10{sup (-13)-(-11)} g cm{sup -3}, which accretes onto and/or transits the line of sight to the black hole, causing an instant decrease in the observed degree of ionization and/or an increase in density of the accreting matter. Continued monitoring for individual events with future X-ray calorimeter missions such as ASTRO-H and AXSIO will allow us to map out the accretion environment in detail and how it changes between the various accretion states.

  20. Evolution of high tooth replacement rates in sauropod dinosaurs.

    Directory of Open Access Journals (Sweden)

    Michael D D'Emic

    Full Text Available BACKGROUND: Tooth replacement rate can be calculated in extinct animals by counting incremental lines of deposition in tooth dentin. Calculating this rate in several taxa allows for the study of the evolution of tooth replacement rate. Sauropod dinosaurs, the largest terrestrial animals that ever evolved, exhibited a diversity of tooth sizes and shapes, but little is known about their tooth replacement rates. METHODOLOGY/PRINCIPAL FINDINGS: We present tooth replacement rate, formation time, crown volume, total dentition volume, and enamel thickness for two coexisting but distantly related and morphologically disparate sauropod dinosaurs Camarasaurus and Diplodocus. Individual tooth formation time was determined by counting daily incremental lines in dentin. Tooth replacement rate is calculated as the difference between the number of days recorded in successive replacement teeth. Each tooth family in Camarasaurus has a maximum of three replacement teeth, whereas each Diplodocus tooth family has up to five. Tooth formation times are about 1.7 times longer in Camarasaurus than in Diplodocus (315 vs. 185 days. Average tooth replacement rate in Camarasaurus is about one tooth every 62 days versus about one tooth every 35 days in Diplodocus. Despite slower tooth replacement rates in Camarasaurus, the volumetric rate of Camarasaurus tooth replacement is 10 times faster than in Diplodocus because of its substantially greater tooth volumes. A novel method to estimate replacement rate was developed and applied to several other sauropodomorphs that we were not able to thin section. CONCLUSIONS/SIGNIFICANCE: Differences in tooth replacement rate among sauropodomorphs likely reflect disparate feeding strategies and/or food choices, which would have facilitated the coexistence of these gigantic herbivores in one ecosystem. Early neosauropods are characterized by high tooth replacement rates (despite their large tooth size, and derived titanosaurs and

  1. Enhancement of the dissolution rate and gastrointestinal absorption of pranlukast as a model poorly water-soluble drug by grinding with gelatin.

    Science.gov (United States)

    Chono, Sumio; Takeda, Eri; Seki, Toshinobu; Morimoto, Kazuhiro

    2008-01-22

    The effect of grinding with gelatin on the dissolution behavior and gastrointestinal absorption of a poorly water-soluble drug was evaluated using the antiasthmatic agent, pranlukast, as a model poorly water-soluble drug. A ground pranlukast-gelatin mixture was prepared by grinding equal quantities of pranlukast and gelatin. In the dissolution testing, the dissolution rate of pranlukast in the suspension of the ground pranlukast-gelatin mixture under conditions of pH 3.0, 5.0 and 7.0 was markedly faster than that in the suspension of pranlukast. According to powder X-ray diffractometry (PXRD) and differential scanning calorimetry (DSC) analysis, the enhanced dissolution rate of pranlukast produced by grinding with gelatin was caused by changing the crystalline state of pranlukast into an amorphous state. In an animal experiment, the bioavailability of pranlukast following oral administration of the ground pranlukast-gelatin mixture to rats was threefold greater than that following administration of pranlukast. In the in vitro permeation experiment, the amount of permeated pranlukast through Caco-2 cell monolayers after application of the ground pranlukast-gelatin mixture was greater than that after application of pranlukast. These results suggest that the enhancement of the gastrointestinal absorption of pranlukast by grinding with gelatin is due to enhancement of the dissolution rate. Grinding a poorly water-soluble drug with gelatin is a useful method of enhancing its gastrointestinal absorption.

  2. X-Ray Absorption Spectroscopic Studies of High-Spin Nonheme (Alkylperoxo)Iron(III) Intermediates

    Energy Technology Data Exchange (ETDEWEB)

    Shan, X.; Rohde, J.-U.; Koehntop, K.D.; Zhou, Y.; Bukowski, M.R.; Costas, M.; Fujisawa, K.; Que, L.; Jr.

    2009-06-04

    The reactions of iron(II) complexes [Fe(Tp{sup t-Bu,i-Pr})(OH)] (1a, Tp{sup t-Bu,i-Pr} = hydrotris(3-tert-butyl-5-isopropyl-1-pyrazolyl)borate), [Fe(6-Me{sub 2}BPMCN)(OTf){sub 2}] (1b, 6-Me{sub 2}BPMCN = N,N'-bis((2-methylpyridin-6-yl)methyl)-N,N'-dimethyl-trans-1,2-diaminocyclohexane), and [Fe(L{sup 8}Py{sub 2})(OTf)](OTf) (1c, L{sup 8}Py{sub 2} = 1,5-bis(pyridin-2-ylmethyl)-1,5-diazacyclooctane) with tert-BuOOH give rise to high-spin Fe{sup III}-OOR complexes. X-ray absorption spectra (XAS) of these high-spin species show characteristic features, distinct from those of low-spin Fe-OOR complexes (Rohde, J.-U.; et al. J. Am. Chem. Soc. 2004, 126, 16750--16761). These include (1) an intense 1s {yields} 3d preedge feature, with an area around 20 units, (2) an edge energy, ranging from 7122 to 7126 eV, that is affected by the coordination environment, and (3) a 1.86--1.96 {angstrom} Fe-OOR bond, compared to the 1.78 {angstrom} Fe-OOR bond in low-spin complexes. These unique features likely arise from a flexible first coordination sphere in those complexes. The difference in Fe-OOR bond length may rationalize differences in reactivity between low-spin and high-spin Fe{sup III}-OOR species.

  3. High gastrointestinal permeability and local metabolism of naringenin: influence of antibiotic treatment on absorption and metabolism.

    Science.gov (United States)

    Orrego-Lagarón, Naiara; Martínez-Huélamo, Miriam; Vallverdú-Queralt, Anna; Lamuela-Raventos, Rosa M; Escribano-Ferrer, Elvira

    2015-07-01

    The present study aims to determine the permeability of naringenin in the stomach, small intestine and colon, to evaluate intestinal and hepatic first-pass metabolism, and to study the influence of the microbiota on the absorption and disposition of naringenin (3.5 μg/ml). A single-pass intestinal perfusion model in mice (n 4-6) was used. Perfusate (every 10 min), blood (at 60 min) and bile samples were taken and analysed to evaluate the presence of naringenin and its metabolites by an HPLC-MS/MS method. To study the influence of the microbiota on the bioavailability of naringenin, a group of animals received the antibiotic rifaximin (50 mg/kg per d) for 5 d, and naringenin permeability was determined in the colon. Naringenin was absorbed well throughout the gastrointestinal tract but mainly in the small intestine and colon (mean permeability coefficient 7.80 (SD 1.54) × 10(-4) cm/s and 5.49 (SD 1.86) × 10(-4) cm/s, respectively), at a level similar to the highly permeable compound, naproxen (6.39 (SD 1.23) × 10(-4) cm/s). According to the high amounts of metabolites found in the perfusate compared to the bile and plasma, naringenin underwent extensive intestinal first-pass metabolism, and the main metabolites excreted were sulfates (84.00 (SD 12.14)%), followed by glucuronides (8.40 (SD 5.67)%). Phase II metabolites were found in all perfusates from 5 min of sampling. Mice treated with rifaximin showed a decrease in naringenin permeability and in the amounts of 4-hydroxyhippuric acid and hippuric acid in the lumen. Naringenin was well absorbed throughout the gastrointestinal tract and its poor bioavailability was due mainly to high intestinal metabolism.

  4. Highly absorptive curcumin reduces serum atherosclerotic low-density lipoprotein levels in patients with mild COPD

    Science.gov (United States)

    Funamoto, Masafumi; Sunagawa, Yoichi; Katanasaka, Yasufumi; Miyazaki, Yusuke; Imaizumi, Atsushi; Kakeya, Hideaki; Yamakage, Hajime; Satoh-Asahara, Noriko; Komiyama, Maki; Wada, Hiromichi; Hasegawa, Koji; Morimoto, Tatsuya

    2016-01-01

    Purpose COPD is mainly caused by tobacco smoking and is associated with a high frequency of coronary artery disease. There is growing recognition that the inflammation in COPD is not only confined to the lungs but also involves the systemic circulation and can impact nonpulmonary organs, including blood vessels. α1-antitrypsin–low-density lipoprotein (AT-LDL) complex is an oxidatively modified LDL that accelerates atherosclerosis. Curcumin, one of the best-investigated natural products, is a powerful antioxidant. However, the effects of curcumin on AT-LDL remain unknown. We hypothesized that Theracurmin®, a highly absorptive curcumin with improved bioavailability using a drug delivery system, ameliorates the inflammatory status in subjects with mild COPD. Patients and methods This is a randomized, double-blind, parallel-group study. Subjects with stages I–II COPD according to the Japanese Respiratory Society criteria were randomly assigned to receive 90 mg Theracurmin® or placebo twice a day for 24 weeks, and changes in inflammatory parameters were evaluated. Results There were no differences between the Theracurmin® and placebo groups in terms of age, male/female ratio, or body mass index in 39 evaluable subjects. The percent changes in blood pressure and hemoglobin A1c and LDL-cholesterol, triglyceride, or high-density lipoprotein-cholesterol levels after treatment were similar for the two groups. However, the percent change in the AT-LDL level was significantly (P=0.020) lower in the Theracurmin® group compared with the placebo group. Conclusion Theracurmin® reduced levels of atherosclerotic AT-LDL, which may lead to the prevention of future cardiovascular events in mild COPD subjects. PMID:27616885

  5. All-metal meta-surfaces for narrowband light absorption and high performance sensing

    Science.gov (United States)

    Liu, Zhengqi; Liu, Guiqiang; Fu, Guolan; Liu, Xiaoshan; Huang, Zhenping; Gu, Gang

    2016-11-01

    We report an experimental scheme for high performance sensing by an all-metal meta-surface (AMMS) platform. A dual-band resonant absorption spectrum with a bandwidth down to a single-digit nanometer level and an absorbance up to 89% is achieved due to the surface lattice resonances supported by the resonators array and their hybridization coupling with the particle plasmon resonances. The sensing application in the analysis of the sodium chloride solution has been demonstrated, where remarkable changes from a spectral ‘dark state’ to ‘bright state’ and vice versa are observed. Sensing performance factors of the figure of merit exceeding 50 and the spectral intensity change related FoM* up to 1075 are simultaneously achieved. The corresponding detection limit is as low as 8.849  ×  10-6 RIU. These features make such an AMMS-based sensor a promising route for efficient bio-chemical sensing, etc.

  6. Direct solid sampling electrothermal atomic absorption spectrometry for the analysis of high-purity niobium pentaoxide.

    Science.gov (United States)

    Huang, M D; Krivan, V

    2000-01-01

    A direct solid sampling electrothermal atomic absorption spectrometry (SoS-ETAAS) method for ultratrace analysis of powdered niobium pentaoxide for Al, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni and Zn has been developed. The elements K, Mg, Na and Zn could be determined without any chemical modification. However, in the determination of the elements Al, Co, Cr, Cu, Fe, Mn and Ni, serious matrix-caused non-spectral interferences and background occurred which made their determination impossible. This problem was remedied by conversion of the niobium pentaoxide matrix into the thermally stable niobium carbide by using methane atmosphere during the pyrolysis stage. The development resulted in establishing an extraordinary powerful method for the analysis of niobium pentaoxide in term of limits of detection, accuracy, simplicity and analysis time. Quantification was performed using calibration curves measured with aqueous standard solutions. The accuracy was checked by comparing the results with those obtained by ETAAS in analysis of slurries and digests of the sample. Due to almost complete freedom of blank and high applicable sample amounts (up to 15 mg), extremely low limits of detection (0.5-2 ng/g) were achieved.

  7. Magnetic relaxation measurements of a high-T{sub c} oxide superconductor using microwave absorption

    Energy Technology Data Exchange (ETDEWEB)

    Noujima, Masafumi; Shiiyama, Kenichi; Kinoshita, Chiken [Kyushu Univ., Fukuoka (Japan)

    1998-09-01

    The pinning potential of Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub x} with and without electron irradiation has been determined. Single crystals of Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub x} were irradiated with 1 MeV electrons at room temperature in a high voltage electron microscope. Magnetic relaxation of the non-irradiated and irradiated crystals was measured with use of a microwave absorption method at T=79 K and magnetic fields, H = 0 - 0.13 T. The relaxation process was described in terms of the pinning potential and its anisotropy to get the following conclusions. (1) The pinning potential of the irradiated crystal is 2.2 times higher than that of the virgin crystal. (2) Isolated point defects, such as vacancies and interstitials provide good pinning centers. (3) The point defects produced by the electron irradiation make the pinning potential anisotropic. (author)

  8. High-resolution x-ray absorption spectroscopy studies of metal compounds in neurodegenerative brain tissue

    Science.gov (United States)

    Collingwood, J. F.; Mikhaylova, A.; Davidson, M. R.; Batich, C.; Streit, W. J.; Eskin, T.; Terry, J.; Barrea, R.; Underhill, R. S.; Dobson, J.

    2005-01-01

    Fluorescence mapping and microfocus X-ray absorption spectroscopy are used to detect, locate and identify iron biominerals and other inorganic metal accumulations in neurodegenerative brain tissue at sub-cellular resolution (reviewed. Synchrotron X-rays are used to map tissue sections for metals of interest, and XANES and XAFS are used to characterise anomalous concentrations of the metals in-situ so that they can be correlated with tissue structures and disease pathology. Iron anomalies associated with biogenic magnetite, ferritin and haemoglobin are located and identified in an avian tissue model with a pixel resolution ~5 microns. Subsequent studies include brain tissue sections from transgenic Huntington's mice, and the first high-resolution mapping and identification of iron biominerals in human Alzheimer's and control autopsy brain tissue. Technical developments include use of microfocus diffraction to obtain structural information about biominerals in-situ, and depositing sample location grids by lithography for the location of anomalies by conventional microscopy. The combined techniques provide a breakthrough in the study of both intra- and extra-cellular iron compounds and related metals in tissue. The information to be gained from this approach has implications for future diagnosis and treatment of neurodegeneration, and for our understanding of the mechanisms involved.

  9. Feasibility of filter atomization in high-resolution continuum source atomic absorption spectrometry

    Science.gov (United States)

    Heitmann, Uwe; Becker-Ross, Helmut; Katskov, Dmitri

    2006-03-01

    A prototype spectrometer for high-resolution continuum source atomic absorption spectrometry (HR-CS AAS), built at ISAS Berlin, Germany, was combined with a graphite filter atomizer (GFA), earlier developed at TUT, Pretoria, South Africa. The furnace and auto-sampler units from a commercial AA spectrometer, model AAS vario 6 (Analytik Jena AG, Jena, Germany), were employed in the instrument. Instead of conventional platform tube, the GFA was used to provide low measurement susceptibility to interferences and short determination cycle. The GFA was modified according to the design of the furnace unit and optimal physical parameters of its components (filter and collector) found. Afterwards, optimal GFA was replicated and tested to outline analytical performances of the HR-CS GFA AA spectrometer in view of prospects of multi-element analysis. In particular, reproducibility of performances, repeatability of analytical signals, lifetime, temperature limit and duration of the measurement cycle were examined, and elements available for determination justified. The results show that the peak area of the atomic absorption signal is reproduced in various GFA copies within ± 4% deviation range. The GFA can stand temperatures of 2800 °C with 6 s hold time for 55 temperature cycles, and 2700 °C (8 s) for about 200 cycles. Only the external tube is prone to destruction while the filter and collector do not show any sign of erosion caused by temperature or aggressive matrix. Analytical signals are affected insignificantly by tube aging. Repeatability of the peak area remains within 1.1-1.7% RSD over more than hundred determination cycles. Peak areas are proportional to the sample volume of injected organic and inorganic liquids up to at least 50 μL. The drying stage is combined with hot sampling and cut down to 15-20 s. The list of metals available for determination with full vapor release includes Al, Co, Cr, Ni, Pt as well as more volatile metals. Characteristic masses at

  10. Single-band high absorption and coupling between localized surface plasmons modes in a metamaterials absorber

    Science.gov (United States)

    Zhong, Min; Liu, Shui Jie; Xu, Bang Li; Wang, Jie; Huang, Hua Qing

    2017-10-01

    In this paper, we design and simulate a metamaterials absorbers based on the resonance of the local surface plasmon (LSP) mode. The damping constant of gold layer is optimized in simulations to eliminate the effect of the inappropriate material parameters on the electromagnetic properties of the proposed metamaterial absorber. The horizontal distance between two metal particles is optimized in simulations and a perfect absorption resonance peak is achieved due to the strong coupling of LSP modes. A new absorption peak is obtained when the horizontal distance is 0 nm. The vertical distance between the new metal particles and the bottom metal layer is reduced, which leads to the absorption peak reduce based on the reduction of the intensity of LSP modes. A new absorption peak is obtained when the new metallic particle and the bottom gold layer form a whole structure.

  11. Industrial refrigeration with high efficiency absorption; Refrigeracion industrial por absorcion de alta eficiencia

    Energy Technology Data Exchange (ETDEWEB)

    Ayala Delgado, R.; Heard, C. L. [Instituto de Investigaciones Electricas, Cuernavaca, (Mexico); Pardubicki, J. [LAJ International, Mexico D. F. (Mexico)

    1995-12-31

    The absorption refrigeration ammonia-lithium nitrate offers great advantages compared with the mechanical compression refrigeration with ammonia as well as with the absorption ammonia-water refrigeration. With heat temperatures of 1000 to 1400 Celsius degrees, for instance low pressure steam the generation of cold at low temperatures (-100 to -200 Celsius degrees) is possible. The system has less components and is much less expensive than the ammonia-water equipment with a price very similar to the ammonia mechanical compression equipment. The equipment consists of five main heat exchangers and a solution pump, resulting in a high reliability of its operation, requiring a minimum maintenance. The operation cost depends directly of the cost of the energy source. In case of using residual heat the operation cost is only the maintenance cost. Nowadays the cost of the electric energy is below the production cost, which can be a short term situation. In time terms of the comparable useful life time of an absorption refrigeration system (in excess of 20 years), it is reasonable to think that the operation costs will be less than the operation costs of an equipment with mechanical compression. To this day it is available a demonstration unit to exhibit the system in industrial plants with different energy sources. [Espanol] La refrigeracion por absorcion amoniaco/nitrato de litio ofrece grandes ventajas comparada tanto con la refrigeracion por compresion mecanica con amoniaco como con la refrigeracion por absorcion amoniaco/agua. Este sistema es mas eficiente y sencillo que el sistema de amoniaco/agua. Con calor de temperatura (100 a 140 grados centigrados por ejemplo vapor de baja presion, se permite la generacion de frio a temperaturas bajas (-10 a -20 grados centigrados). El sistema tiene menos componentes y es mucho mas barato que equipo de amoniaco/agua con un precio muy similar a sistemas por compresion mecanica de amoniaco. El sistema consiste en cinco

  12. High Frame Rate Synthetic Aperture 3D Vector Flow Imaging

    DEFF Research Database (Denmark)

    Villagómez Hoyos, Carlos Armando; Holbek, Simon; Stuart, Matthias Bo

    2016-01-01

    3-D blood flow quantification with high spatial and temporal resolution would strongly benefit clinical research on cardiovascular pathologies. Ultrasonic velocity techniques are known for their ability to measure blood flow with high precision at high spatial and temporal resolution. However......, current volumetric ultrasonic flow methods are limited to one velocity component or restricted to a reduced field of view (FOV), e.g. fixed imaging planes, in exchange for higher temporal resolutions. To solve these problems, a previously proposed accurate 2-D high frame rate vector flow imaging (VFI......) technique is extended to estimate the 3-D velocity components inside a volume at high temporal resolutions (

  13. High Strain Rate Behavior of Polymer Matrix Composites Analyzed

    Science.gov (United States)

    Goldberg, Robert K.; Roberts, Gary D.

    2001-01-01

    Procedures for modeling the high-speed impact of composite materials are needed for designing reliable composite engine cases that are lighter than the metal cases in current use. The types of polymer matrix composites that are likely to be used in such an application have a deformation response that is nonlinear and that varies with strain rate. To characterize and validate material models that could be used in the design of impactresistant engine cases, researchers must obtain material data over a wide variety of strain rates. An experimental program has been carried out through a university grant with the Ohio State University to obtain deformation data for a representative polymer matrix composite for strain rates ranging from quasi-static to high rates of several hundred per second. This information has been used to characterize and validate a constitutive model that was developed at the NASA Glenn Research Center.

  14. Study of High Strain Rate Response of Composites

    Science.gov (United States)

    Gilat, Amos

    2003-01-01

    The objective of the research was to continue the experimental study of the effect of strain rate on mechanical response (deformation and failure) of epoxy resins and carbon fibers/epoxy matrix composites, and to initiate a study of the effects of temperature by developing an elevated temperature test. The experimental data provide the information needed for NASA scientists for the development of a nonlinear, rate dependent deformation and strength models for composites that can subsequently be used in design. This year effort was directed into testing the epoxy resin. Three types of epoxy resins were tested in tension and shear at various strain rates that ranges from 5 x 10(exp -5), to 1000 per second. Pilot shear experiments were done at high strain rate and an elevated temperature of 80 C. The results show that all, the strain rate, the mode of loading, and temperature significantly affect the response of epoxy.

  15. STIR: Tailored Interfaces for High Strength Composites Across Strain Rates

    Science.gov (United States)

    2013-09-02

    was requested during our kickoff meeting at ARL APG. High performance fabrics including Kevlar, Twaron, Zylon , and Dyneema are used in developing...Kevlar, and Zylon for various pullout rates. Force– displacement data was recorded, and both warp and fill yarns were pulled from the fabric. Their...results presented that the effect of pullout rate is negligible for Kevlar, whereas the effect is bigger on Spectra, and significant for Zylon

  16. Absorption cross-section measurements of methane, ethane, ethylene and methanol at high temperatures

    KAUST Repository

    Alrefae, Majed

    2014-09-01

    Mid-IR absorption cross-sections are measured for methane, ethane, ethylene and methanol over 2800-3400 cm-1 (2.9-3.6 μm) spectral region. Measurements are carried out using a Fourier-Transform-Infrared (FTIR) spectrometer with temperatures ranging 296-1100 K and pressures near atmospheric. As temperature increases, the peak cross-sections decrease but the wings of the bands increase as higher rotational lines appear. Integrated band intensity is also calculated over the measured spectral region and is found to be a very weak function of temperature. The absorption cross-sections of the relatively small fuels studied here show dependence on the bath gas. This effect is investigated by studying the variation of absorption cross-sections at 3.392 μm using a HeNe laser in mixtures of fuel and nitrogen, argon, or helium. Mixtures of fuel with He have the highest value of absorption cross-sections followed by Ar and N2. Molecules with narrow absorption lines, such as methane and methanol, show strong dependence on bath gas than molecules with relatively broader absorption features i.e. ethane and ethylene. © 2014 Elsevier Inc. All rights reserved.

  17. Absorption cross-section measurements of methane, ethane, ethylene and methanol at high temperatures

    Science.gov (United States)

    Alrefae, Majed; Es-sebbar, Et-touhami; Farooq, Aamir

    2014-09-01

    Mid-IR absorption cross-sections are measured for methane, ethane, ethylene and methanol over 2800-3400 cm-1 (2.9-3.6 μm) spectral region. Measurements are carried out using a Fourier-Transform-Infrared (FTIR) spectrometer with temperatures ranging 296-1100 K and pressures near atmospheric. As temperature increases, the peak cross-sections decrease but the wings of the bands increase as higher rotational lines appear. Integrated band intensity is also calculated over the measured spectral region and is found to be a very weak function of temperature. The absorption cross-sections of the relatively small fuels studied here show dependence on the bath gas. This effect is investigated by studying the variation of absorption cross-sections at 3.392 μm using a HeNe laser in mixtures of fuel and nitrogen, argon, or helium. Mixtures of fuel with He have the highest value of absorption cross-sections followed by Ar and N2. Molecules with narrow absorption lines, such as methane and methanol, show strong dependence on bath gas than molecules with relatively broader absorption features i.e. ethane and ethylene.

  18. High rate tests of the LHCb RICH Upgrade system

    CERN Multimedia

    Blago, Michele Piero

    2016-01-01

    One of the biggest challenges for the upgrade of the LHCb RICH detectors from 2020 is to readout the photon detectors at the full 40 MHz rate of the LHC proton-proton collisions. A test facility has been setup at CERN with the purpose to investigate the behaviour of the Multi Anode PMTs, which have been proposed for the upgrade, and their readout electronics at high trigger rates. The MaPMTs are illuminated with a monochromatic laser that can be triggered independently of the readout electronics. A first series of tests, including threshold scans, is performed at low trigger rates (20 kHz) for both the readout and the laser with the purpose to characterise the behaviour of the system under test. Then the trigger rate is increased in two separate steps. First the MaPMTs are exposed to high illumination by triggering the pulsed laser at a high (20 MHz) repetition rate while the DAQ is readout at the same low rate as before. In this way the performance of the MaPMTs and the attached electronics can be evaluated ...

  19. Nanoengineering Titania for High Rate Lithium Storage: A Review

    Institute of Scientific and Technical Information of China (English)

    Chunhai Jiang; Jinsong Zhang

    2013-01-01

    Nanostructured titania have been intensively investigated as anode materials of Li-ion batteries for their excellent high rate performance.The size effects of TiO2 polymorphs (mainly rutile,anatase and TiO2-B) on their electrochemical performance and the latest efforts in nanoengineering titania anodes through enhancing their ionic or electronic transportation or both are reviewed in this work.We suppose that micron-or submicronsized porous structures assembled by TiO2 nanoparticles,nanowires/nanotubes or nanosheets with a high percentage of exposing high reactive facets together with a conductive percolating network are ideal anodes not only for high rate lithium storage but also for high packing densities of the active materials.

  20. Semi-solid electrodes having high rate capability

    Energy Technology Data Exchange (ETDEWEB)

    Chiang, Yet-Ming; Duduta, Mihai; Holman, Richard; Limthongkul, Pimpa; Tan, Taison

    2016-07-05

    Embodiments described herein relate generally to electrochemical cells having high rate capability, and more particularly to devices, systems and methods of producing high capacity and high rate capability batteries having relatively thick semi-solid electrodes. In some embodiments, an electrochemical cell includes an anode, a semi-solid cathode that includes a suspension of an active material and a conductive material in a liquid electrolyte, and an ion permeable membrane disposed between the anode and the cathode. The semi-solid cathode has a thickness in the range of about 250 .mu.m-2,500 .mu.m, and the electrochemical cell has an area specific capacity of at least 5 mAh/cm.sup.2 at a C-rate of C/2.

  1. Semi-solid electrodes having high rate capability

    Energy Technology Data Exchange (ETDEWEB)

    Chiang, Yet-Ming; Duduta, Mihai; Holman, Richard; Limthongkul, Pimpa; Tan, Taison

    2015-11-10

    Embodiments described herein relate generally to electrochemical cells having high rate capability, and more particularly to devices, systems and methods of producing high capacity and high rate capability batteries having relatively thick semi-solid electrodes. In some embodiments, an electrochemical cell includes an anode, a semi-solid cathode that includes a suspension of an active material and a conductive material in a liquid electrolyte, and an ion permeable membrane disposed between the anode and the cathode. The semi-solid cathode has a thickness in the range of about 250 .mu.m-2,500 .mu.m, and the electrochemical cell has an area specific capacity of at least 5 mAh/cm.sup.2 at a C-rate of C/2.

  2. High strain rate compression testing of glass fibre reinforced polypropylene

    Directory of Open Access Journals (Sweden)

    Cloete T.J.

    2012-08-01

    Full Text Available This paper details an investigation of the high strain rate compression testing of GFPP with the Split Hopkinson Pressure Bar (SHPB in the through-thickness and in-plane directions. GFPP posed challenges to SHPB testing as it fails at relatively high stresses, while having relatively low moduli and hence mechanical impedance. The modifications to specimen geometry and incident pulse shaping in order to gather valid test results, where specimen equilibrium was achieved for SHPB tests on GFPP are presented. In addition to conventional SHPB tests to failure, SHPB experiments were designed to achieve specimen equilibration at small strains, which permitted the capture of high strain rate elastic modulus data. The strain rate dependency of GFPP’s failure strengths in the in-plane and through-thickness direction is modelled using a logarithmic law.

  3. High-Strain Rate Mechanical Response of Cured Epoxy Networks

    Science.gov (United States)

    Sirk, Timothy; Khare, Ketan; Karim, Mir; Lenhart, Joseph; Khare, Rajesh; Andzelm, Jan

    2013-03-01

    Chemically cross-linked polymer networks are increasingly common in high performance composites, adhesives and other applications involving high-impact loading conditions or ballistic collisions. The mechanical behavior of epoxy and other polymer networks exhibit a strong dependence on strain rate near the glass transition temperature (Tg); however, the elastic modulus at strain rates greater than 105 1/s is difficult to capture with experimental techniques. We present computational results of Di-Glycidyl Ether of Bisphenol A (DGEBA) and Jeffamine diamines (D230) from molecular dynamics simulation, which is intrinsically well-suited to model material deformation at high strain rates. Our results show that the experimental Tg can be reproduced from molecular dynamics, and the Williams-Landel-Ferry equation is useful in rationalizing the shift of Tg due to fast annealing and high strain rates. Temperature sweeps of elastic modulus show the glass-rubber transition to occur over a significantly wider temperature range compared with experimental measurements at low strain rates.

  4. Influence of a low- and a high-oxalate vegetarian diet on intestinal oxalate absorption and urinary excretion.

    Science.gov (United States)

    Thomas, E; von Unruh, G E; Hesse, A

    2008-09-01

    To compare quantitatively the effect of a low- and a high-oxalate vegetarian diet on intestinal oxalate absorption and urinary excretion. Eight healthy volunteers (three men and five women, mean age 28.6+/-6.3) were studied. Each volunteer performed the [(13)C(2)]oxalate absorption test thrice on a low-oxalate mixed diet, thrice on a low-oxalate vegetarian diet and thrice on a high-oxalate vegetarian diet. For each test, the volunteers had to adhere to an identical diet and collect their 24-h urines. In the morning of the second day, a capsule containing [(13)C(2)]oxalate was ingested. On the low-oxalate vegetarian diet, mean intestinal oxalate absorption and urinary oxalate excretion increased significantly to 15.8+/-2.9% (P=0.012) and 0.414+/-0.126 mmol/day (P=0.012), compared to the mixed diet. On the high-oxalate vegetarian diet, oxalate absorption (12.5+/-4.6%, P=0.161) and urinary excretion (0.340+/-0.077 mmol/day, P=0.093) did not change significantly, compared to the mixed diet. A vegetarian diet can only be recommended for calcium oxalate stone patients, if the diet (1) contains the recommended amounts of divalent cations such as calcium and its timing of ingestion to a meal rich in oxalate is considered and (2) excludes foodstuffs with a high content of nutritional factors, such as phytic acid, which are able to chelate calcium.

  5. High removal rate laser-based coating removal system

    Science.gov (United States)

    Matthews, Dennis L.; Celliers, Peter M.; Hackel, Lloyd; Da Silva, Luiz B.; Dane, C. Brent; Mrowka, Stanley

    1999-11-16

    A compact laser system that removes surface coatings (such as paint, dirt, etc.) at a removal rate as high as 1000 ft.sup.2 /hr or more without damaging the surface. A high repetition rate laser with multiple amplification passes propagating through at least one optical amplifier is used, along with a delivery system consisting of a telescoping and articulating tube which also contains an evacuation system for simultaneously sweeping up the debris produced in the process. The amplified beam can be converted to an output beam by passively switching the polarization of at least one amplified beam. The system also has a personal safety system which protects against accidental exposures.

  6. Strategies for adapting to high rates of employee turnover.

    Science.gov (United States)

    Mowday, R T

    1984-01-01

    For many organizations facing high rates of employee turnover, strategies for increasing employee retention may not be practical because employees leave for reasons beyond the control of management or the costs of reducing turnover exceed the benefits to be derived. In this situation managers need to consider strategies that can minimize or buffer the organization from the negative consequences that often follow from turnover. Strategies organizations can use to adapt to uncontrollably high employee turnover rates are presented in this article. In addition, suggestions are made for how managers should make choices among the alternative strategies.

  7. Refractive Index and Absorption Attribution of Highly Absorbing Brown Carbon Aerosols from an Urban Indian City-Kanpur

    Science.gov (United States)

    Shamjad, P. M.; Tripathi, S. N.; Thamban, Navaneeth M.; Vreeland, Heidi

    2016-11-01

    Atmospheric aerosols influence Earth’s radiative balance, having both warming and cooling effects. Though many aerosols reflect radiation, carbonaceous aerosols such as black carbon and certain organic carbon species known as brown carbon have the potential to warm the atmosphere by absorbing light. Black carbon absorbs light over the entire solar spectrum whereas brown carbon absorbs near-UV wavelengths and, to a lesser extent, visible light. In developing countries, such as India, where combustion sources are prolific, the influence of brown carbon on absorption may be significant. In order to better characterize brown carbon, we present experimental and modeled absorption properties of submicron aerosols measured in an urban Indian city (Kanpur). Brown carbon here is found to be fivefold more absorbing at 365 nm wavelength compared to previous studies. Results suggest ~30% of total absorption in Kanpur is attributed to brown carbon, with primary organic aerosols contributing more than secondary organics. We report the spectral brown carbon refractive indices along with an experimentally constrained estimate of the influence of aerosol mixing state on absorption. We conclude that brown carbon in Kanpur is highly absorbing in nature and that the mixing state plays an important role in light absorption from volatile species.

  8. Determination of blood counts at sideropenic anemia, and monitoring depending on the outcome rate of iron absorption

    OpenAIRE

    PANOCHOVÁ, Daniela

    2011-01-01

    Sideropenic anemia (iron deficiency anemia) is the most common anemia all over the world. The cause of this anemia type is lack of iron. This thesis deals with the determination of blood picture treatment results and iron absorption in patients with sideropenic anemia. In the practical part, the methods of blood picture determination as well as iron determination and the resorption curve are described. The blood picture is provided at the Clinical Haematology Ward of the České Budějovice Hosp...

  9. The impact of cell-specific absorption properties on the correlation of electron transport rates measured by chlorophyll fluorescence and photosynthetic oxygen production in planktonic algae.

    Science.gov (United States)

    Blache, Ulrich; Jakob, Torsten; Su, Wanwen; Wilhelm, Christian

    2011-08-01

    Photosynthesis-irradiance (P-E)-curves describe the photosynthetic performance of autotrophic organisms. From these P-E-curves the photosynthetic parameters α-slope, P(max), and E(k) can be deduced which are often used to characterize and to compare different organisms or organisms in acclimation to different environmental conditions. Particularly, for in situ-measurements of P-E curves of phytoplankton the analysis of variable chlorophyll fluorescence proved its potential as a sensitive and rapid method. By using Chlorella vulgaris (Trebouxiophyceae), Nannochloropsis salina (Eustigmatophyceae), Skeletonema costatum and Cyclotella meneghiniana (Bacillariophyceae), the present study investigated the influence of cellular bio-optical properties on the correlation of the photosynthetic parameters derived from fluorescence-based P-E-curves with photosynthetic parameters obtained from the measurement of oxygen evolution. It is demonstrated that small planktonic algae show a wide range of cellular absorptivity which was subject to species-specifity, growth stage and environmental conditions, e.g. nutrient limitation. This variability in bio-optical properties resulted in a great deviation of relative electron transport rates (rETRs) from oxygen-based photosynthesis rates. Thus, the photosynthetic parameters α-slope and P(max) derived from rETRs strongly depend on the specific cellular absorptivity and cannot be used to compare the photosynthetic performance of cells with different optical properties. However, it was shown that E(k) is independent of cellular absorptivity and could be used to compare samples with unknown optical properties.

  10. High frame rate CCD camera with fast optical shutter

    Energy Technology Data Exchange (ETDEWEB)

    Yates, G.J.; McDonald, T.E. Jr. [Los Alamos National Lab., NM (United States); Turko, B.T. [Lawrence Berkeley National Lab., CA (United States)

    1998-09-01

    A high frame rate CCD camera coupled with a fast optical shutter has been designed for high repetition rate imaging applications. The design uses state-of-the-art microchannel plate image intensifier (MCPII) technology fostered/developed by Los Alamos National Laboratory to support nuclear, military, and medical research requiring high-speed imagery. Key design features include asynchronous resetting of the camera to acquire random transient images, patented real-time analog signal processing with 10-bit digitization at 40--75 MHz pixel rates, synchronized shutter exposures as short as 200pS, sustained continuous readout of 512 x 512 pixels per frame at 1--5Hz rates via parallel multiport (16-port CCD) data transfer. Salient characterization/performance test data for the prototype camera are presented, temporally and spatially resolved images obtained from range-gated LADAR field testing are included, an alternative system configuration using several cameras sequenced to deliver discrete numbers of consecutive frames at effective burst rates up to 5GHz (accomplished by time-phasing of consecutive MCPII shutter gates without overlap) is discussed. Potential applications including dynamic radiography and optical correlation will be presented.

  11. Glitch-free X-ray absorption spectrum under high pressure obtained using nano-polycrystalline diamond anvils

    Energy Technology Data Exchange (ETDEWEB)

    Ishimatsu, Naoki, E-mail: naoki@sci.hiroshima-u.ac.jp; Matsumoto, Ken; Maruyama, Hiroshi [Department of Physics, Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashihiroshima, Hiroshima 739-8526 (Japan); Kawamura, Naomi; Mizumaki, Masaichiro [Japan Synchrotron Radiation Research Institute (JASRI), SPring-8, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Sumiya, Hitoshi [Electronics and Materials R& D Laboratories, Sumitomo Electric Industries, 1-1-1 Koyakita, Itami, Hyogo 664-0016 (Japan); Irifune, Tetsuo [Geodynamics Research Center, Ehime University, 2-5 Bunkyo-cho, Matsuyama 790-8577 (Japan)

    2012-09-01

    Nano-polycrystalline diamond has been used to obtain a glitch-free X-ray absorption spectrum under high pressure. The advantage and capability of nano-polycrystalline diamond anvils is discussed by a comparison of the glitch map with that of single-crystal diamond anvils. Nano-polycrystalline diamond (NPD) [Irifune et al. (2003 ▶), Nature (London), 421, 599] has been used to obtain a glitch-free X-ray absorption spectrum under high pressure. In the case of conventional single-crystal diamond (SCD) anvils, glitches owing to Bragg diffraction from the anvils are superimposed on X-ray absorption spectra. The glitch has long been a serious problem for high-pressure research activities using X-ray spectroscopy because of the difficulties of its complete removal. It is demonstrated that NPD is one of the best candidate materials to overcome this problem. Here a glitch-free absorption spectrum using the NPD anvils over a wide energy range is shown. The advantage and capability of NPD anvils is discussed by a comparison of the glitch map with that of SCD anvils.

  12. User microprogrammable processors for high data rate telemetry preprocessing

    Science.gov (United States)

    Pugsley, J. H.; Ogrady, E. P.

    1973-01-01

    The use of microprogrammable processors for the preprocessing of high data rate satellite telemetry is investigated. The following topics are discussed along with supporting studies: (1) evaluation of commercial microprogrammable minicomputers for telemetry preprocessing tasks; (2) microinstruction sets for telemetry preprocessing; and (3) the use of multiple minicomputers to achieve high data processing. The simulation of small microprogrammed processors is discussed along with examples of microprogrammed processors.

  13. Study of the microstructure evolution of zirconium alloy during deuterium absorption at high temperature

    Science.gov (United States)

    Zhang, Cheng; Yang, Yun; Zhang, Yin; Liu, Jingru; You, Li; Song, Xiping

    2017-09-01

    In the exploration of fusion power, zirconium alloy has been viewed as a potential deuterium storage material to store and deliver deuterium fuel into fusion reactors, due to its large deuterium storage capacity, low deuterium desorption pressure and fast deuterium absorption kinetics. But it often cracks after deuterium absorption. In this study, the microstructure and deuterium absorption kinetic of β-Zr in various deuteriding conditions (pressure, time and temperature) were investigated. The results showed that, with the increase of deuteriding pressures from 1 bar to 3 bar at 1173 K, the deuteride content and the deuteride morphology changed significantly. During deuterium absorption at 3 bar, the surface deuteride layer was formed first, and then the inner deuteride network was gradually developed with the time. There existed an apparent deuterium concentration gradient from surface to center. With the increase of deuteriding temperatures from 973 K to 1173 K, the deuteride content decreased. The kinetic of deuterium absorption at 1173 K was found to be affected by the deuteriding pressures. Transmission electron microscopy (TEM) results showed that ε deuterides nucleated and grew at the interface of δ deuterides, and small bands with different crystal orientation were found within the ε deuterides. The γ deuterides were found at 3 bar, within which twins and tweed structure were observed. An orientation relationship of δ//ε, {111}δ//{111}ε between δ and ε deuterides was also determined by TEM analysis.

  14. An HST/COS legacy survey of high-velocity ultraviolet absorption in the Milky Way's circumgalactic medium and the Local Group

    CERN Document Server

    Richter, P; Fox, A J; Wakker, B P; Lehner, N; Bekhti, N Ben; Fechner, C; Wendt, M; Howk, J C; Muzahid, S; Ganguly, R; Charlton, J C

    2016-01-01

    To characterize the absorption properties of this circumgalactic medium (CGM) and its relation to the LG we present the so-far largest survey of metal absorption in Galactic high-velocity clouds (HVCs) using archival ultraviolet (UV) spectra of extragalactic background sources. The UV data are obtained with the Cosmic Origins Spectrograph (COS) onboard the Hubble Space Telescope (HST) and are supplemented by 21 cm radio observations of neutral hydrogen. Along 262 sightlines we measure metal absorption in the lines of SiII, SiIII, CII, and CIV and associated HI 21 cm emission in HVCs in the velocity range |v_LSR|=100-500 km s^-1. With this unprecedented large HVC sample we were able to improve the statistics on HVC covering fractions, ionization conditions, small-scale structure, CGM mass, and inflow rate. For the first time, we determine robustly the angular two point correlation function of the high-velocity absorbers, systematically analyze antipodal sightlines on the celestial sphere, and compare the absor...

  15. Pedalling rate affects endurance performance during high-intensity cycling

    DEFF Research Database (Denmark)

    Nielsen, Jens Steen; Hansen, Ernst Albin; Sjøgaard, Gisela

    2004-01-01

    , such as muscle fibre type composition and power reserve, relate to endurance time. Twenty males underwent testing to determine their maximal oxygen uptake (VO(2max)), power output corresponding to 90% of VO(2max) at 80 rpm (W90), FCPR at W90, percentage of slow twitch muscle fibres (% MHC I), maximal leg power...... time was negatively related to VO(2max), W90 and % MHC I, while positively related to power reserve. In conclusion, at group level, endurance time was longer at FCPR and at a pedalling rate 25% lower compared to a pedalling rate 25% higher than FCPR. Further, inter-individual physiological variables......The purpose of this study into high-intensity cycling was to: (1) test the hypothesis that endurance time is longest at a freely chosen pedalling rate (FCPR), compared to pedalling rates 25% lower (FCPR-25) and higher (FCPR+25) than FCPR, and (2) investigate how physiological variables...

  16. Evaluation of dissolution rate on high plutonium content MOX fuel

    Energy Technology Data Exchange (ETDEWEB)

    Sugaya, Shinichi; Kurita, Ichiro; Endo, Hideo; Higuchi, Hidetoshi; Kihara, Yoshiyuki [Japan Nuclear Cycle Development Inst., Tokai Works, Tokai, Ibaraki (Japan); Ogasawara, Masahiro; Shinada, Masanori; Kowata, Masato [Inspection Development Company Ltd., Tokai, Ibaraki (Japan)

    2002-06-01

    The dissolution rate of high Pu content MOX fuel into nitric acid was measured as a function of Pu content. MOX fuel samples, pressed and sintered, were dissolved in 7 M of boiling nitric acid, and the dissolution rate was measured by analyzing the Pu and U concentration in the solution. The dissolution rate of MOX fuel tended to decrease with the increase in the Pu content and was reduced after 6 hours of dissolution. These results agreed well with previous ones, but the dissolution rate was 3-6 times faster than those. It is estimated that the cause of this difference was due to underestimation of the surface area of MOX fuel powder and the difference of the MOX O/M ratio. (author)

  17. Methanol conversion in high-rate anaerobic reactors

    NARCIS (Netherlands)

    Weijma, J.; Stams, A.J.M.

    2001-01-01

    An overview on methanol conversion in high-rate anaerobic reactors is presented, with the focus on technological as well as microbiological aspects. The simple C1-compound methanol can be degraded anaerobically in a complex way, in which methanogens, sulfate reducing bacteria and homoacetogens

  18. READOUT ELECTRONICS FOR A HIGH-RATE CSC DETECTOR

    Energy Technology Data Exchange (ETDEWEB)

    OCONNOR,P.; GRATCHEV,V.; KANDASAMY,A.; POLYCHRONAKOS,V.; TCHERNIATINE,V.; PARSONS,J.; SIPPACH,W.

    1999-09-25

    A readout system for a high-rate muon Cathode Strip Chamber (CSC) is described. The system, planned for use in the forward region of the ATLAS muon spectrometer, uses two custom CMOS integrated circuits to achieve good position resolution at a flux of up to 2,500 tracks/cm{sup 2}/s.

  19. Childhood Onset Schizophrenia: High Rate of Visual Hallucinations

    Science.gov (United States)

    David, Christopher N.; Greenstein, Deanna; Clasen, Liv; Gochman, Pete; Miller, Rachel; Tossell, Julia W.; Mattai, Anand A.; Gogtay, Nitin; Rapoport, Judith L.

    2011-01-01

    Objective: To document high rates and clinical correlates of nonauditory hallucinations in childhood onset schizophrenia (COS). Method: Within a sample of 117 pediatric patients (mean age 13.6 years), diagnosed with COS, the presence of auditory, visual, somatic/tactile, and olfactory hallucinations was examined using the Scale for the Assessment…

  20. High Reported Spontaneous Stuttering Recovery Rates: Fact or Fiction?

    Science.gov (United States)

    Ramig, Peter R.

    1993-01-01

    Contact after 6 to 8 years with families of 21 children who were diagnosed as stuttering but did not receive fluency intervention services found that almost all subjects still had a stuttering problem. Results dispute the high spontaneous recovery rates reported in the literature and support the value of early intervention. (Author/DB)

  1. High deposition rate nanocrystalline silicon with enhanced homogeneity

    Energy Technology Data Exchange (ETDEWEB)

    Verkerk, Arjan; Rath, Jatindra K.; Schropp, Ruud [Section Nanophotonics-Physics of Devices, Debye Institute for Nanomaterials Science, Faculty of Science, Utrecht University, P.O. Box 80000, 3508 TA Utrecht (Netherlands)

    2010-03-15

    High rate growth of hydrogenated nanocrystalline silicon (nc-Si:H) brings additional challenges for the homogeneity in the growth direction, since the start-up effects affect a larger portion of the film, and the very high degree of depletion increases the influence of back diffusion from the inactive region into the plasma zone. It was calculated that back diffusion plays a role in the regime for high deposition rate (4.5 nm/s) via the residence time for particles in the plasma and the corresponding diffusion length for silane from outside the plasma. The stabilization time for back diffusion was derived and found to be on the order of tens of seconds. Experiment showed that the incubation layer for nc-Si:H is very thick in films deposited at a high rate compared to films deposited in a regime of lower deposition rate. The use of a hydrogen plasma start greatly reduced this incubation layer. Further control of the crystalline fraction could be achieved via slight reduction of the degree of depletion via the silane flow. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  2. Advances in high rate anaerobic treatment: staging of reactor systems.

    NARCIS (Netherlands)

    Lier, van J.B.; Zee, van der F.P.; Tan, N.C.G.; Rebac, S.; Kleerebezem, R.

    2001-01-01

    Anaerobic wastewater treatment (AnWT) is considered as the most cost-effective solution for organically polluted industrial waste streams. Particularly the development of high-rate systems, in which hydraulic retention times are uncoupled from solids retention times, has led to a world-wide acceptan

  3. Adapting high-rate anaerobic treatment to Middle East conditions

    NARCIS (Netherlands)

    Mahmoud, N.A.; Zeeman, G.; Lier, van J.B.

    2008-01-01

    High-rate anaerobic technologies offer cost-effective solutions for sewage treatment in the Middle East and Palestine in particular. The sewage characteristics in Palestine are quite different from the values elsewhere and show solids contents of more than 1000 mg chemical oxygen demand (COD)ss/L

  4. Binary interactions with high accretion rates onto main sequence stars

    Science.gov (United States)

    Shiber, Sagiv; Schreier, Ron; Soker, Noam

    2016-07-01

    Energetic outflows from main sequence stars accreting mass at very high rates might account for the powering of some eruptive objects, such as merging main sequence stars, major eruptions of luminous blue variables, e.g., the Great Eruption of Eta Carinae, and other intermediate luminosity optical transients (ILOTs; red novae; red transients). These powerful outflows could potentially also supply the extra energy required in the common envelope process and in the grazing envelope evolution of binary systems. We propose that a massive outflow/jets mediated by magnetic fields might remove energy and angular momentum from the accretion disk to allow such high accretion rate flows. By examining the possible activity of the magnetic fields of accretion disks, we conclude that indeed main sequence stars might accrete mass at very high rates, up to ≈ 10-2 M ⊙ yr-1 for solar type stars, and up to ≈ 1 M ⊙ yr-1 for very massive stars. We speculate that magnetic fields amplified in such extreme conditions might lead to the formation of massive bipolar outflows that can remove most of the disk's energy and angular momentum. It is this energy and angular momentum removal that allows the very high mass accretion rate onto main sequence stars.

  5. Understanding High School Graduation Rates in the District of Columbia

    Science.gov (United States)

    Alliance for Excellent Education, 2009

    2009-01-01

    Graduation rates are a fundamental indicator of whether or not the nation's public school system is doing what it is intended to do: enroll, engage, and educate youth to be productive members of society. Since almost 90 percent of the fastest-growing and highest-paying jobs require some postsecondary education, having a high school diploma and the…

  6. Understanding High School Graduation Rates in New Mexico

    Science.gov (United States)

    Alliance for Excellent Education, 2009

    2009-01-01

    Graduation rates are a fundamental indicator of whether or not the nation's public school system is doing what it is intended to do: enroll, engage, and educate youth to be productive members of society. Since almost 90 percent of the fastest-growing and highest-paying jobs require some postsecondary education, having a high school diploma and the…

  7. Understanding High School Graduation Rates in Rhode Island

    Science.gov (United States)

    Alliance for Excellent Education, 2009

    2009-01-01

    Graduation rates are a fundamental indicator of whether or not the nation's public school system is doing what it is intended to do: enroll, engage, and educate youth to be productive members of society. Since almost 90 percent of the fastest-growing and highest-paying jobs require some postsecondary education, having a high school diploma and the…

  8. Understanding High School Graduation Rates in South Dakota

    Science.gov (United States)

    Alliance for Excellent Education, 2009

    2009-01-01

    Graduation rates are a fundamental indicator of whether or not the nation's public school system is doing what it is intended to do: enroll, engage, and educate youth to be productive members of society. Since almost 90 percent of the fastest-growing and highest-paying jobs require some postsecondary education, having a high school diploma and the…

  9. Understanding High School Graduation Rates in West Virginia

    Science.gov (United States)

    Alliance for Excellent Education, 2009

    2009-01-01

    Graduation rates are a fundamental indicator of whether or not the nation's public school system is doing what it is intended to do: enroll, engage, and educate youth to be productive members of society. Since almost 90 percent of the fastest-growing and highest-paying jobs require some postsecondary education, having a high school diploma and the…

  10. Understanding High School Graduation Rates in North Carolina

    Science.gov (United States)

    Alliance for Excellent Education, 2009

    2009-01-01

    Graduation rates are a fundamental indicator of whether or not the nation's public school system is doing what it is intended to do: enroll, engage, and educate youth to be productive members of society. Since almost 90 percent of the fastest-growing and highest-paying jobs require some postsecondary education, having a high school diploma and the…

  11. Understanding High School Graduation Rates in South Carolina

    Science.gov (United States)

    Alliance for Excellent Education, 2009

    2009-01-01

    Graduation rates are a fundamental indicator of whether or not the nation's public school system is doing what it is intended to do: enroll, engage, and educate youth to be productive members of society. Since almost 90 percent of the fastest-growing and highest-paying jobs require some postsecondary education, having a high school diploma and the…

  12. Understanding High School Graduation Rates in North Dakota

    Science.gov (United States)

    Alliance for Excellent Education, 2009

    2009-01-01

    Graduation rates are a fundamental indicator of whether or not the nation's public school system is doing what it is intended to do: enroll, engage, and educate youth to be productive members of society. Since almost 90 percent of the fastest-growing and highest-paying jobs require some postsecondary education, having a high school diploma and the…

  13. Understanding High School Graduation Rates in New York

    Science.gov (United States)

    Alliance for Excellent Education, 2009

    2009-01-01

    Graduation rates are a fundamental indicator of whether or not the nation's public school system is doing what it is intended to do: enroll, engage, and educate youth to be productive members of society. Since almost 90 percent of the fastest-growing and highest-paying jobs require some postsecondary education, having a high school diploma and the…

  14. Understanding High School Graduation Rates in the United States

    Science.gov (United States)

    Alliance for Excellent Education, 2009

    2009-01-01

    Graduation rates are a fundamental indicator of whether or not the nation's public school system is doing what it is intended to do: enroll, engage, and educate youth to be productive members of society. Since almost 90 percent of the fastest-growing and highest-paying jobs require some postsecondary education, having a high school diploma and the…

  15. Understanding High School Graduation Rates in New Hampshire

    Science.gov (United States)

    Alliance for Excellent Education, 2009

    2009-01-01

    Graduation rates are a fundamental indicator of whether or not the nation's public school system is doing what it is intended to do: enroll, engage, and educate youth to be productive members of society. Since almost 90 percent of the fastest-growing and highest-paying jobs require some postsecondary education, having a high school diploma and the…

  16. Understanding High School Graduation Rates in New Jersey

    Science.gov (United States)

    Alliance for Excellent Education, 2009

    2009-01-01

    Graduation rates are a fundamental indicator of whether or not the nation's public school system is doing what it is intended to do: enroll, engage, and educate youth to be productive members of society. Since almost 90 percent of the fastest-growing and highest-paying jobs require some postsecondary education, having a high school diploma and the…

  17. Highly absorptive curcumin reduces serum atherosclerotic low-density lipoprotein levels in patients with mild COPD

    Directory of Open Access Journals (Sweden)

    Funamoto M

    2016-08-01

    Full Text Available Masafumi Funamoto,1,2 Yoichi Sunagawa,1–3 Yasufumi Katanasaka,1–3 Yusuke Miyazaki,1,2 Atsushi Imaizumi,4 Hideaki Kakeya,5 Hajime Yamakage,2 Noriko Satoh-Asahara,2 Maki Komiyama,2 Hiromichi Wada,2 Koji Hasegawa,2 Tatsuya Morimoto1–3 1Division of Molecular Medicine, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, 2Clinical Research Institute, National Hospital Organization Kyoto Medical Center, Kyoto, 3Shizuoka General Hospital, Shizuoka, 4Theravalues Corporation, Kioicho, Tokyo, 5Department of System Chemotherapy and Molecular Sciences, Division of Bioinformatics and Chemical Genomics, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan Purpose: COPD is mainly caused by tobacco smoking and is associated with a high frequency of coronary artery disease. There is growing recognition that the inflammation in COPD is not only confined to the lungs but also involves the systemic circulation and can impact nonpulmonary organs, including blood vessels. α1-antitrypsin–low-density lipoprotein (AT-LDL complex is an oxidatively modified LDL that accelerates atherosclerosis. Curcumin, one of the best-investigated natural products, is a powerful antioxidant. However, the effects of curcumin on AT-LDL remain unknown. We hypothesized that Theracurmin®, a highly absorptive curcumin with improved bioavailability using a drug delivery system, ameliorates the inflammatory status in subjects with mild COPD.Patients and methods: This is a randomized, double-blind, parallel-group study. Subjects with stages I–II COPD according to the Japanese Respiratory Society criteria were randomly assigned to receive 90 mg Theracurmin® or placebo twice a day for 24 weeks, and changes in inflammatory parameters were evaluated.Results: There were no differences between the Theracurmin® and placebo groups in terms of age, male/female ratio, or body mass index in 39 evaluable subjects. The percent changes in blood pressure

  18. Reionization and high-redshift galaxies: the view from quasar absorption lines

    CERN Document Server

    Becker, George D; Lidz, Adam

    2015-01-01

    Determining when and how the first galaxies reionized the intergalactic medium (IGM) promises to shed light on both the nature of the first objects and the cosmic history of baryons. Towards this goal, quasar absorption lines play a unique role by probing the properties of diffuse gas on galactic and intergalactic scales. In this review we examine the multiple ways in which absorption lines trace the connection between galaxies and the IGM near the reionization epoch. We first describe how the Ly$\\alpha$ forest is used to determine the intensity of the ionizing ultraviolet background and the global ionizing emissivity budget. Critically, these measurements reflect the escaping ionizing radiation from all galaxies, including those too faint to detect directly. We then discuss insights from metal absorption lines into reionization-era galaxies and their surroundings. Current observations suggest a buildup of metals in the circumgalactic environments of galaxies over $z \\sim 6$ to 5, although changes in ionizati...

  19. Experimental demonstration of terahertz metamaterial absorbers with a broad and flat high absorption band.

    Science.gov (United States)

    Huang, Li; Chowdhury, Dibakar Roy; Ramani, Suchitra; Reiten, Matthew T; Luo, Sheng-Nian; Taylor, Antoinette J; Chen, Hou-Tong

    2012-01-15

    We present the design, numerical simulations and experimental measurements of terahertz metamaterial absorbers with a broad and flat absorption top over a wide incidence angle range for either transverse electric or transverse magnetic polarization depending on the incident direction. The metamaterial absorber unit cell consists of two sets of structures resonating at different but close frequencies. The overall absorption spectrum is the superposition of individual components and becomes flat at the top over a significant bandwidth. The experimental results are in excellent agreement with numerical simulations.

  20. Studies on anodic oxide coating with low absorptance and high emittance on aluminum alloy 2024

    Energy Technology Data Exchange (ETDEWEB)

    Siva Kumar, C. [Department of Post-graduate studies in Chemistry, Central College, Bangalore (India); Sharma, A.K. [Thermal Process Section, ISRO Satellite Centre, Vimanapura Post, Bangalore (India); Mahendra, K.N.; Mayanna, S.M. [Department of Post-graduate studies in Chemistry, Central College, Bangalore (India)

    2000-01-01

    Anodization of AA 2024 in sulfuric acid bath containing glycerol, lactic acid and ammonium metavenadate has been studied to develop white anodic oxide coating. Investigation on the influence of various operating parameters - coating thickness, current density and ammonium metavenadate concentration on the optical properties was carried out to optimize the process. Infrared, atomic absorption spectroscopic techniques and scanning electron micrograph were used to characterize the coating. The obtained oxide coating provides a ratio of solar absorptance ({alpha}) to infrared emittance ({epsilon}), as low as 0.2. The optical properties and hardness values measured under optimum experimental conditions support its use as a thermal control coating.

  1. Mechanisms of high heart rate variability: a fresh look

    Directory of Open Access Journals (Sweden)

    Vladimir A. Lukyanchenko

    2016-05-01

    Full Text Available Consideration is being given herein to some mechanisms of high heart rate variability (high HRV, which cannot be attributed to sports exercise loading. The mechanism responsible for high HRV is explained as that resulted from the continuous performance (opening and closure of arteriovenous anastomoses in different organs and systems in a human organism. An assessment of this phenomenon is given herein from the point of view of a practicing physician who treats regularly patients with already established clinical diagnoses and those without an established nosological profile according to International Statistical Classification of Diseases and Related Health Problems 10th Revision.

  2. OFDM-based Low-voltage Powerline High Rate Communication

    Institute of Scientific and Technical Information of China (English)

    ZHANG You-bing(张有兵); CHENG Shi-jie(程时杰); Joseph Nguimbis; XIONG Lan(熊兰)

    2004-01-01

    Based on the experimental results, a simplified model for low-voltage powerline used as a high frequency communication channel is presented. With this model, the Orthogonal Frequency Division Multiplexing (OFDM) based high rate digital communication over low-voltage powerline is analyzed and simulated. The capability of thc signal transmission system in overcoming multi-path interference and selection of the system parameters are discussed. And time-domain simulation is carried out to investigate the transmission capability of the OFDM cammunication system for different mapping schemes and transmission power levels. Simulation results show that it is possible to realize high rate digital communication over iow-voltage powerliue using OFDM when the transmitted power is large enough.

  3. High strain rate behavior of pure metals at elevated temperature

    Science.gov (United States)

    Testa, Gabriel; Bonora, Nicola; Ruggiero, Andrew; Iannitti, Gianluca; Domenico, Gentile

    2013-06-01

    In many applications and technology processes, such as stamping, forging, hot working etc., metals and alloys are subjected to elevated temperature and high strain rate deformation process. Characterization tests, such as quasistatic and dynamic tension or compression test, and validation tests, such as Taylor impact and DTE - dynamic tensile extrusion -, provide the experimental base of data for constitutive model validation and material parameters identification. Testing material at high strain rate and temperature requires dedicated equipment. In this work, both tensile Hopkinson bar and light gas gun where modified in order to allow material testing under sample controlled temperature conditions. Dynamic tension tests and Taylor impact tests, at different temperatures, on high purity copper (99.98%), tungsten (99.95%) and 316L stainless steel were performed. The accuracy of several constitutive models (Johnson and Cook, Zerilli-Armstrong, etc.) in predicting the observed material response was verified by means of extensive finite element analysis (FEA).

  4. A High Rate Tension Device for Characterizing Brain Tissue

    CERN Document Server

    Rashid, Badar; Gilchrist, Michael; 10.1177/1754337112436900

    2013-01-01

    The mechanical characterization of brain tissue at high loading velocities is vital for understanding and modeling Traumatic Brain Injury (TBI). The most severe form of TBI is diffuse axonal injury (DAI) which involves damage to individual nerve cells (neurons). DAI in animals and humans occurs at strains > 10% and strain rates > 10/s. The mechanical properties of brain tissues at these strains and strain rates are of particular significance, as they can be used in finite element human head models to accurately predict brain injuries under different impact conditions. Existing conventional tensile testing machines can only achieve maximum loading velocities of 500 mm/min, whereas the Kolsky bar apparatus is more suitable for strain rates > 100/s. In this study, a custom-designed high rate tension device is developed and calibrated to estimate the mechanical properties of brain tissue in tension at strain rates < 90/s, while maintaining a uniform velocity. The range of strain can also be extended to 100% de...

  5. VUV absorption spectroscopy measurements of the role of fast neutral atoms in high-power gap breakdown

    Energy Technology Data Exchange (ETDEWEB)

    FILUK,A.B.; BAILEY,JAMES E.; CUNEO,MICHAEL E.; LAKE,PATRICK WAYNE; NASH,THOMAS J.; NOACK,DONALD D.; MARON,Y.

    2000-03-20

    The maximum power achieved in a wide variety of high-power devices, including electron and ion diodes, z pinches, and microwave generators, is presently limited by anode-cathode gap breakdown. A frequently-discussed hypothesis for this effect is ionization of fast neutral atoms injected throughout the anode-cathode gap during the power pulse. The authors describe a newly-developed diagnostic tool that provides the first direct test of this hypothesis. Time-resolved vacuum-ultraviolet absorption spectroscopy is used to directly probe fast neutral atoms with 1 mm spatial resolution in the 10 mm anode-cathode gap of the SABRE 5 MV, 1 TW applied-B ion diode. Absorption spectra collected during Ar RF glow discharges and with CO{sub 2} gas fills confirm the reliability of the diagnostic technique. Throughout the 50--100 ns ion diode pulses no measurable neutral absorption is seen, setting upper limits of 0.12--1.5 x 10{sup 14} cm{sup {minus}3} for ground state fast neutral atom densities of H, C, N, O, F. The absence of molecular absorption bands also sets upper limits of 0.16--1.2 x 10{sup 15} cm{sup {minus}3} for common simple molecules. These limits are low enough to rule out ionization throughout the gap as a breakdown mechanism. This technique can now be applied to quantify the role of neutral atoms in other high-power devices.

  6. Fluorine determination in coal using high-resolution graphite furnace molecular absorption spectrometry and direct solid sample analysis

    Energy Technology Data Exchange (ETDEWEB)

    Machado, Patrícia M.; Morés, Silvane; Pereira, Éderson R. [Departamento de Química, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, SC (Brazil); Welz, Bernhard, E-mail: w.bernardo@terra.com.br [Departamento de Química, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, SC (Brazil); Instituto Nacional de Ciência e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, 40170-115 Salvador, BA (Brazil); Carasek, Eduardo [Departamento de Química, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, SC (Brazil); Andrade, Jailson B. de [Instituto Nacional de Ciência e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, 40170-115 Salvador, BA (Brazil)

    2015-03-01

    The absorption of the calcium mono-fluoride (CaF) molecule has been employed in this study for the determination of fluorine in coal using direct solid sample analysis and high-resolution continuum source graphite furnace molecular absorption spectrometry (HR-CS GF MAS). The rotational line at 606.440 nm was used for measuring the molecular absorption in the gas phase. The pyrolysis and vaporization temperatures were 700 °C and 2100 °C, respectively. Different chemical modifiers have been studied, such as Pd and Ir as permanent modifiers, and Pd and the mixed Pd/Mg modifier in solution. The limit of detection and the characteristic mass were 0.3 and 0.1 ng F, respectively. One certified reference material (CRM) of coal (NIST 1635) and four CRMs with a non-certified value for F (SARM 18, SARM 20, BCR 40, BCR 180) were used to evaluate the accuracy and precision of the method, obtaining good agreement (104%) with the certified value and with the informed values (ranging from 90 to 103%). - Highlights: • High-resolution Graphite Furnace Molecular Absorption Spectrometry (HR-GF MAS) • Fluorine has been determined using HR-GF MAS of the CaF molecule. • The CaF molecule was generated in a graphite furnace at a temperature of 2100 °C • Coal samples have been analyzed using direct solid sample introduction. • Aqueous standard solutions have been used for calibration.

  7. Systematic Uncertainties in High-Rate Germanium Data

    Energy Technology Data Exchange (ETDEWEB)

    Gilbert, Andrew J.; Fast, James E.; Fulsom, Bryan G.; Pitts, William K.; VanDevender, Brent A.; Wood, Lynn S.

    2016-10-06

    For many nuclear material safeguards inspections, spectroscopic gamma detectors are required which can achieve high event rates (in excess of 10^6 s^-1) while maintaining very good energy resolution for discrimination of neighboring gamma signatures in complex backgrounds. Such spectra can be useful for non-destructive assay (NDA) of spent nuclear fuel with long cooling times, which contains many potentially useful low-rate gamma lines, e.g., Cs-134, in the presence of a few dominating gamma lines, such as Cs-137. Detectors in use typically sacrifice energy resolution for count rate, e.g., LaBr3, or visa versa, e.g., CdZnTe. In contrast, we anticipate that beginning with a detector with high energy resolution, e.g., high-purity germanium (HPGe), and adapting the data acquisition for high throughput will be able to achieve the goals of the ideal detector. In this work, we present quantification of Cs-134 and Cs-137 activities, useful for fuel burn-up quantification, in fuel that has been cooling for 22.3 years. A segmented, planar HPGe detector is used for this inspection, which has been adapted for a high-rate throughput in excess of 500k counts/s. Using a very-high-statistic spectrum of 2.4*10^11 counts, isotope activities can be determined with very low statistical uncertainty. However, it is determined that systematic uncertainties dominate in such a data set, e.g., the uncertainty in the pulse line shape. This spectrum offers a unique opportunity to quantify this uncertainty and subsequently determine required counting times for given precision on values of interest.

  8. The dynamic Virtual Fields Method on rubbers at medium and high strain rates

    Directory of Open Access Journals (Sweden)

    Yoon Sung-Ho

    2015-01-01

    Full Text Available Elastomeric materials are widely used for energy absorption applications, often experiencing high strain rate deformations. The mechanical characterization of rubbers at high strain rates presents several experimental difficulties, especially associated with achieving adequate signal to noise ratio and static stress equilibrium, when using a conventional technique such as the split Hopkinson pressure bar. In the present study, these problems are avoided by using the dynamic Virtual Fields Method (VFM in which acceleration fields, clearly generated by the non-equilibrium state, are utilized as a force measurement with in the frame work of the principle of virtual work equation. In this paper, two dynamic VFM based techniques are used to characterise an EPDM rubber. These are denoted as the linear and nonlinear VFM and are developed for (respectively medium (drop-weight and high (gas-gun strain-rate experiments. The use of the two VFMs combined with high-speed imaging analysed by digital imaging correlation allows the identification of the parameters of a given rubber mechanical model; in this case the Ogden model is used.

  9. Highly variable rates of genome rearrangements between hemiascomycetous yeast lineages.

    Directory of Open Access Journals (Sweden)

    2006-03-01

    Full Text Available Hemiascomycete yeasts cover an evolutionary span comparable to that of the entire phylum of chordates. Since this group currently contains the largest number of complete genome sequences it presents unique opportunities to understand the evolution of genome organization in eukaryotes. We inferred rates of genome instability on all branches of a phylogenetic tree for 11 species and calculated species-specific rates of genome rearrangements. We characterized all inversion events that occurred within synteny blocks between six representatives of the different lineages. We show that the rates of macro- and microrearrangements of gene order are correlated within individual lineages but are highly variable across different lineages. The most unstable genomes correspond to the pathogenic yeasts Candida albicans and Candida glabrata. Chromosomal maps have been intensively shuffled by numerous interchromosomal rearrangements, even between species that have retained a very high physical fraction of their genomes within small synteny blocks. Despite this intensive reshuffling of gene positions, essential genes, which cluster in low recombination regions in the genome of Saccharomyces cerevisiae, tend to remain syntenic during evolution. This work reveals that the high plasticity of eukaryotic genomes results from rearrangement rates that vary between lineages but also at different evolutionary times of a given lineage.

  10. Numerical analysis of specific absorption rate in the human head due to a 13.56 MHz RFID-based intra-ocular pressure measurement system

    Science.gov (United States)

    Hirtl, Rene; Schmid, Gernot

    2013-09-01

    A modern wireless intra-ocular pressure monitoring system, based on 13.56 MHz inductively coupled data transmission, was dosimetrically analyzed with respect to the specific absorption rate (SAR) induced inside the head and the eye due to the electromagnetic field exposure caused by the reader antenna of the transmission system. The analysis was based on numerical finite difference time domain computations using a high resolution anatomical eye model integrated in a modern commercially available anatomical model of a male head. Three different reader antenna configurations, a 7-turn elliptic (30 mm × 50 mm) antenna at 12 mm distance from the eye, a flexible circular antenna (60 mm diameter, 8 turns on 2 mm substrate) directly attached to the skin, and a circular 7-turn antenna (30 mm diameter at 12 mm distance to the eye) were analyzed, respectively. Possible influences of the eye-lid status (closed or opened) and the transponder antenna contained in a contact lens directly attached to the eye were taken into account. The results clearly demonstrated that for typical reader antenna currents required for proper data transmission, the SAR values remain far below the limits for localized exposure of the head, as defined by the International Commission for Non-Ionizing Radiation Protection. Particularly the induced SAR inside the eye was found to be substantially (orders of magnitudes for typical reader antenna currents in the order of 1 A turn) below values which have been reported to be critical with respect to thermally induced adverse health effects in eye tissues.

  11. Demonstration of a high repetition rate capillary discharge waveguide

    Energy Technology Data Exchange (ETDEWEB)

    Gonsalves, A. J., E-mail: ajgonsalves@lbl.gov; Pieronek, C.; Daniels, J.; Bulanov, S. S.; Waldron, W. L.; Mittelberger, D. E.; Leemans, W. P. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Liu, F.; Antipov, S.; Butler, J. E. [Euclid TechLabs, Gaithersburg, Maryland 20879 (United States); Bobrova, N. A.; Sasorov, P. V. [Keldysh Institute of Applied Mathematics, Moscow (Russian Federation)

    2016-01-21

    A hydrogen-filled capillary discharge waveguide operating at kHz repetition rates is presented for parameters relevant to laser plasma acceleration (LPA). The discharge current pulse was optimized for erosion mitigation with laser guiding experiments and MHD simulation. Heat flow simulations and measurements showed modest temperature rise at the capillary wall due to the average heat load at kHz repetition rates with water-cooled capillaries, which is promising for applications of LPAs such as high average power radiation sources.

  12. Physical characteristics of the Selectron high dose rate intracavitary afterloader

    Energy Technology Data Exchange (ETDEWEB)

    Chenery, S.G.A.; Pla, M.; Podgorsak, E.B. (Royal Victoria Hospital, Montreal, Quebec (Canada); McGill Univ., Montreal, Quebec (Canada))

    1985-08-01

    The physics measurements on a Selectron high dose-rate afterloading cobalt-60 unit are reported. The installation was found to be acceptable from the standpoint of radiation safety and cost effectiveness; hospital bed space was saved as treatment could be on an outpatient basis. A source calibration 4% higher than the value stated by the manufacturer was obtained. Measurement of the ratio of exposure rate in water to that in air confirmed the calibration and the applicability of correction factors for routine clinical dosimetry recommended in the literature.

  13. Nanocrystalline silicon prepared at high growth rate using helium dilution

    Indian Academy of Sciences (India)

    Koyel Bhattacharya; Debajyoti Das

    2008-06-01

    Growth and optimization of the nanocrystalline silicon (nc-Si : H) films have been studied by varying the electrical power applied to the helium diluted silane plasma in RF glow discharge. Wide optical gap and conducting intrinsic nanocrystalline silicon network of controlled crystalline volume fraction and oriented crystallographic lattice planes have been obtained at a reasonably high growth rate from helium diluted silane plasma, without using hydrogen. Improving crystallinity in the network comprising ∼ 10 nm Si-nanocrystallites and contributing optical gap widening, conductivity ascending and that obtained during simultaneous escalation of the deposition rate, promises significant technological impact.

  14. Temperature-dependent absorption and emission of potassium double tungstates with high ytterbium content

    NARCIS (Netherlands)

    Yong, Yean Sheng; Aravazhi, S.; Vázquez-Córdova, Sergio Andrés; Carvajal, J.J.; Diaz, F.; Herek, Jennifer Lynn; García Blanco, Sonia Maria; Pollnau, Markus

    2016-01-01

    We study the spectroscopic properties of thin films of potassium ytterbium gadolinium double tungstates, KYb0.57Gd0.43(WO4)2, and potassium ytterbium lutetium double tungstates, KYb0.76Lu0.24(WO4)2, specifically at the central absorption line near 981 nm wavelength, which is important for amplifiers

  15. Highly efficient absorption of visible and near infrared light in convex gold and nickel grooves

    DEFF Research Database (Denmark)

    Eriksen, René Lynge; Beermann, Jonas; Søndergaard, Thomas;

    The realization of nonresonant light absorption with nanostructured metal surfaces by making practical use of nanofocusing optical energy in tapered plasmonic waveguides, is of one of the most fascinating and fundamental phenomena in plasmonics [1,2]. We recently realized broadband light absorpti...

  16. Multi-Epoch Observations of Extremely High-Velocity Emergent Broad Absorption

    CERN Document Server

    Rogerson, Jesse A; Hidalgo, Paola Rodríguez; Pirkola, Patrik; Brandt, William N; Ak, Nur Filiz

    2015-01-01

    We present the discovery of the highest velocity CIV broad absorption line to date in the z=2.47 quasar SDSS J023011.28+005913.6, hereafter J0230. In comparing the public DR7 and DR9 spectra of J0230, we discovered an emerging broad absorption trough outflowing at~60,000 km/s. In pursuing follow up observations we discovered a second emergent broad absorption trough outflowing at ~40,000 km/s. We collected seven spectral epochs of J0230 that demonstrate emergent and rapidly (~10 days in the rest-frame) varying broad absorption. We investigate two possible scenarios that could cause these rapid changes: bulk motion and ionization variability. Given our multi-epoch data, a transverse motion scenario would likely be a flow-tube feature travelling across the emitting region at 8,000 =1540 cm^-3 and is at r_{eq} >= 1.37 kpc, or is at r < 1.37 kpc with no constraint on the density.

  17. Quench absorption coils: a quench protection concept for high-field superconducting accelerator magnets

    Science.gov (United States)

    Mentink, M.; Salmi, T.

    2017-06-01

    A quench protection concept based on coupled secondary coils is studied for inductively transferring energy out of a quenching superconducting dipole and thus limiting the peak hotspot temperature. So-called ‘quench absorption coils’ are placed in close proximity to the superconducting coils and are connected in series with a diode for the purpose of preventing current transformation during regular operation. During a quench, current is then transformed into the quench absorption coils so that a significant fraction of the stored magnetic energy is dissipated in the these coils. Numerical calculations are performed to determine the impact of such a concept and to evaluate the dimensions of the quench absorption coils needed to obtain significant benefits. A previously constructed 15 T Nb3Sn block coil is taken as a reference layout. Finite-element calculations are used to determine the combined inductive and thermal response of this system and these calculations are validated with a numerical model using an adiabatic approximation. The calculation results indicate that during a quench the presence of the quench absorption coils reduces the energy dissipated in the superconducting coils by 45% and reduces the hotspot temperature by over 100 K. In addition, the peak resistive voltage over the superconducting coils is significantly reduced. This suggests that this concept may prove useful for magnet designs in which the hotspot temperature is a design driver.

  18. Determination of Tensile Properties of Polymers at High Strain Rates

    Directory of Open Access Journals (Sweden)

    Major Z.

    2010-06-01

    Full Text Available In the field of high rate testing of polymers the measured properties are highly dependent on the applied methodology. Hence, the test setup as whole but in particular also the geometrical type of specimen plays a decisive role. The widely used standard for the determination of tensile properties of polymers (ISO527-2 was extended by a novel standard (ISO18872:2007, which is targeted on the determination of tensile properties at high strain rates. In this standard also a novel specimen shape is proposed. Hand in hand with the introduction of new specimen geometry the question of comparability arises. To point out the differences in stress-strain response of the ISO18872 specimen and the ISO527-2 multipurpose specimen tensile tests over a wide loading rate range were conducted in this paper. A digital image correlation system in combination with a high speed camera was used to characterize the local material behaviour. Different parameters like nominal stress, true stress, nominal strain, true strain as well as volumetric strain were determined and used to compare the two specimen geometries.

  19. Enhanced Rates of Hydrogen Absorption Resulting from Oxidation of Pd and Internal Oxidation of Pd-Al Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Shanahan, K.L.

    1999-08-20

    The goal of this research was the determination of the relative rates before and after internal oxidation of Pd--Al alloys and oxidation (Pd) and this is independent of whether heat transfer is the rate-limiting step for the internally oxidized Pd--Al alloys rather than a more fundamental step.

  20. High paracellular nutrient absorption in intact bats is associated with high paracellular permeability in perfused intestinal segments.

    Science.gov (United States)

    Brun, Antonio; Price, Edwin R; Gontero-Fourcade, Manuel N; Fernandez-Marinone, Guido; Cruz-Neto, Ariovaldo P; Karasov, William H; Caviedes-Vidal, Enrique

    2014-09-15

    Water-soluble nutrients are absorbed by the small intestine via transcellular and paracellular mechanisms. Based on a few previous studies, the capacity for paracellular nutrient absorption seems greater in flying mammals than in nonflying mammals, but there has been little investigation of the mechanisms driving this difference. Therefore, we studied three species each of bats (Artibeus lituratus, Sturnira lilium and Carollia perspicillata) and nonflying mammals (Akodon montensis, Mus musculus and Rattus norvegicus). Using standard pharmacokinetic techniques in intact animals, we confirmed the greater paracellular nutrient absorption in the fliers, comparing one species in each group. Then we conducted in situ intestinal perfusions on individuals of all species. In both approaches, we measured the absorption of 3OMD-glucose, a nonmetabolizable glucose analog absorbed both paracellularly and transcellularly, as well as L-arabinose, which has no mediated transport. Fractional absorption of L-arabinose was three times higher in the bat (S. lilium: 1.2±0.24) than in the rodent (A. montensis: 0.35±0.04), whereas fractional absorption of 3OMD-glucose was complete in both species (1.46±0.4 and 0.97±0.12, respectively). In agreement, bats exhibited two to 12 times higher l-arabinose clearance per square centimeter nominal surface area than rodents in intestinal perfusions. Using L-arabinose, we estimated that the contribution of the paracellular pathway to total glucose absorption was higher in all three bats (109-137%) than in the rodents (13-39%). These findings contribute to an emerging picture that reliance on the paracellular pathway for nutrient absorption is much greater in bats relative to nonflying mammals and that this difference is driven by differences in intestinal permeability to nutrient-sized molecules.

  1. High Pressure Burn Rate Measurements on an Ammonium Perchlorate Propellant

    Energy Technology Data Exchange (ETDEWEB)

    Glascoe, E A; Tan, N

    2010-04-21

    High pressure deflagration rate measurements of a unique ammonium perchlorate (AP) based propellant are required to design the base burn motor for a Raytheon weapon system. The results of these deflagration rate measurements will be key in assessing safety and performance of the system. In particular, the system may experience transient pressures on the order of 100's of MPa (10's kPSI). Previous studies on similar AP based materials demonstrate that low pressure (e.g. P < 10 MPa or 1500 PSI) burn rates can be quite different than the elevated pressure deflagration rate measurements (see References and HPP results discussed herein), hence elevated pressure measurements are necessary in order understand the deflagration behavior under relevant conditions. Previous work on explosives have shown that at 100's of MPa some explosives will transition from a laminar burn mechanism to a convective burn mechanism in a process termed deconsolidative burning. The resulting burn rates that are orders-of-magnitude faster than the laminar burn rates. Materials that transition to the deconsolidative-convective burn mechanism at elevated pressures have been shown to be considerably more violent in confined heating experiments (i.e. cook-off scenarios). The mechanisms of propellant and explosive deflagration are extremely complex and include both chemical, and mechanical processes, hence predicting the behavior and rate of a novel material or formulation is difficult if not impossible. In this work, the AP/HTPB based material, TAL-1503 (B-2049), was burned in a constant volume apparatus in argon up to 300 MPa (ca. 44 kPSI). The burn rate and pressure were measured in-situ and used to calculate a pressure dependent burn rate. In general, the material appears to burn in a laminar fashion at these elevated pressures. The experiment was reproduced multiple times and the burn rate law using the best data is B = (0.6 {+-} 0.1) x P{sup (1.05{+-}0.02)} where B is the burn

  2. Determination of drug absorption rate in time-variant disposition by direct deconvolution using beta clearance correction and end-constrained non-parametric regression.

    Science.gov (United States)

    Neelakantan, S; Veng-Pedersen, P

    2005-11-01

    A novel numerical deconvolution method is presented that enables the estimation of drug absorption rates under time-variant disposition conditions. The method involves two components. (1) A disposition decomposition-recomposition (DDR) enabling exact changes in the unit impulse response (UIR) to be constructed based on centrally based clearance changes iteratively determined. (2) A non-parametric, end-constrained cubic spline (ECS) input response function estimated by cross-validation. The proposed DDR-ECS method compensates for disposition changes between the test and the reference administrations by using a "beta" clearance correction based on DDR analysis. The representation of the input response by the ECS method takes into consideration the complex absorption process and also ensures physiologically realistic approximations of the response. The stability of the new method to noisy data was evaluated by comprehensive simulations that considered different UIRs, various input functions, clearance changes and a novel scaling of the input function that includes the "flip-flop" absorption phenomena. The simulated input response was also analysed by two other methods and all three methods were compared for their relative performances. The DDR-ECS method provides better estimation of the input profile under significant clearance changes but tends to overestimate the input when there were only small changes in the clearance.

  3. Multiplexed CV quantum teleportation for high rates in quantum communication

    CERN Document Server

    Christ, Andreas; Silberhorn, Christine

    2012-01-01

    A major challenge of today's quantum communication systems lies in the transmission of quantum information with high rates over long distances in the presence of unavoidable losses. Thereby the achievable quantum communication rate is fundamentally limited by the amount of energy that can be transmitted per use of the channel. It is hence vital to develop quantum communication protocols which encode quantum information as energy efficiently as possible. To this aim we investigate continuous-variable quantum teleportation as a method of distributing quantum information. We explore the possibility to encode information on multiple optical modes and derive upper and lower bounds on the achievable quantum channel capacities. This analysis enables us to benchmark single-mode vs. multi-mode entanglement resources. Our research reveals that multiplexing does not only feature an enhanced energy efficiency, significantly increasing the achievable quantum communication rates in comparison to single-mode coding, but als...

  4. High data rate recording: Moving to 2 Gbit/s

    Science.gov (United States)

    Taratorin, A.; Yuan, S.; Nikitin, V.

    2003-05-01

    High data rate recording can be achieved using fast write drivers and fast heads. Advanced short-yoke write heads and write drivers with 450 ps rise time and programmable current overshoot were used to study recording at data rates up to 2 Gbit/s. The head flux rise time causes shifts of recorded transitions. It is well known that current overshoot helps to overcome bandwidth limitations in the write driver, interconnects, and write head. However, excessive overshoot may cause pattern-dependent transition shifts and significant distortions of recorded transitions. We present the data rate performance of short-yoke recording heads, analysis of nonlinear pattern-dependent distortions, and optimization of the write current wave form in the 1-2 Gbit/s range. Simple dibit and tribit patterns were recorded at 2 Gbit/s. Low-distortion recording for arbitrary data patterns was demonstrated at 1.6 Gbit/s after optimization of write current overshoot.

  5. Dynamic High-Temperature Characterization of an Iridium Alloy in Compression at High Strain Rates

    Energy Technology Data Exchange (ETDEWEB)

    Song, Bo [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Experimental Environment Simulation Dept.; Nelson, Kevin [Sandia National Lab. (SNL-CA), Livermore, CA (United States). Mechanics of Materials Dept.; Lipinski, Ronald J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Advanced Nuclear Fuel Cycle Technology Dept.; Bignell, John L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Structural and Thermal Analysis Dept.; Ulrich, G. B. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Radioisotope Power Systems Program; George, E. P. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Radioisotope Power Systems Program

    2014-06-01

    Iridium alloys have superior strength and ductility at elevated temperatures, making them useful as structural materials for certain high-temperature applications. However, experimental data on their high-temperature high-strain-rate performance are needed for understanding high-speed impacts in severe elevated-temperature environments. Kolsky bars (also called split Hopkinson bars) have been extensively employed for high-strain-rate characterization of materials at room temperature, but it has been challenging to adapt them for the measurement of dynamic properties at high temperatures. Current high-temperature Kolsky compression bar techniques are not capable of obtaining satisfactory high-temperature high-strain-rate stress-strain response of thin iridium specimens investigated in this study. We analyzed the difficulties encountered in high-temperature Kolsky compression bar testing of thin iridium alloy specimens. Appropriate modifications were made to the current high-temperature Kolsky compression bar technique to obtain reliable compressive stress-strain response of an iridium alloy at high strain rates (300 – 10000 s-1) and temperatures (750°C and 1030°C). Uncertainties in such high-temperature high-strain-rate experiments on thin iridium specimens were also analyzed. The compressive stress-strain response of the iridium alloy showed significant sensitivity to strain rate and temperature.

  6. Optimization of synthesis and peptization steps to obtain iron oxide nanoparticles with high energy dissipation rates

    Energy Technology Data Exchange (ETDEWEB)

    Mérida, Fernando [Deparment of Chemical Engineering, University of Puerto Rico, Mayagüez, P.O. Box 9046, Mayagüez, PR 00680 (United States); Chiu-Lam, Andreina [Department of Chemical Engineering, University of Florida, P.O. Box 116005, Gainesville, FL 32611-6005 (United States); Bohórquez, Ana C. [J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, P.O. Box 116131, Gainesville, FL 32611-6131 (United States); Maldonado-Camargo, Lorena [Department of Chemical Engineering, University of Florida, P.O. Box 116005, Gainesville, FL 32611-6005 (United States); Pérez, María-Eglée; Pericchi, Luis [Department of Mathematics, University of Puerto Rico, Río Piedras, P.O. Box 70377, San Juan, PR 00936-8377 (United States); Torres-Lugo, Madeline [Deparment of Chemical Engineering, University of Puerto Rico, Mayagüez, P.O. Box 9046, Mayagüez, PR 00680 (United States); Rinaldi, Carlos, E-mail: carlos.rinaldi@bme.ufl.edu [Department of Chemical Engineering, University of Florida, P.O. Box 116005, Gainesville, FL 32611-6005 (United States); J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, P.O. Box 116131, Gainesville, FL 32611-6131 (United States)

    2015-11-15

    Magnetic Fluid Hyperthermia (MFH) uses heat generated by magnetic nanoparticles exposed to alternating magnetic fields to cause a temperature increase in tumors to the hyperthermia range (43–47 °C), inducing apoptotic cancer cell death. As with all cancer nanomedicines, one of the most significant challenges with MFH is achieving high nanoparticle accumulation at the tumor site. This motivates development of synthesis strategies that maximize the rate of energy dissipation of iron oxide magnetic nanoparticles, preferable due to their intrinsic biocompatibility. This has led to development of synthesis strategies that, although attractive from the point of view of chemical elegance, may not be suitable for scale-up to quantities necessary for clinical use. On the other hand, to date the aqueous co-precipitation synthesis, which readily yields gram quantities of nanoparticles, has only been reported to yield sufficiently high specific absorption rates after laborious size selective fractionation. This work focuses on improvements to the aqueous co-precipitation of iron oxide nanoparticles to increase the specific absorption rate (SAR), by optimizing synthesis conditions and the subsequent peptization step. Heating efficiencies up to 1048 W/g{sub Fe} (36.5 kA/m, 341 kHz; ILP=2.3 nH m{sup 2} kg{sup −1}) were obtained, which represent one of the highest values reported for iron oxide particles synthesized by co-precipitation without size-selective fractionation. Furthermore, particles reached SAR values of up to 719 W/g{sub Fe} (36.5 kA/m, 341 kHz; ILP=1.6 nH m{sup 2} kg{sup −1}) when in a solid matrix, demonstrating they were capable of significant rates of energy dissipation even when restricted from physical rotation. Reduction in energy dissipation rate due to immobilization has been identified as an obstacle to clinical translation of MFH. Hence, particles obtained with the conditions reported here have great potential for application in nanoscale thermal

  7. Sensitivity of tropical rainbelt over Africa and Middle East to dust shortwave absorption: Experiments using a high resolution AGCM

    KAUST Repository

    Bangalath, Hamza Kunhu

    2015-04-01

    Response of the rainbelt over Africa to dust direct radiative forcing has been an area of lively debate and is a subject of ongoing research. Previous modeling studies have contrasting results producing different amplitudes or even signs of responses. Uncertainties in the dust radiative forcing are thought to be the major cause of discrepancies in the simulated responses among various studies. The imaginary part of mineral dust shortwave refractive index, which defines the dust absorptivity, has a wide range of values estimated from various observational and modeling studies, as it depends on dust chemical composition and mineralogy. Balkanski et al. (2007) estimated dust shortwave refractive indices by assuming 3 different hematite contents, 0.9%, 1.5% and 2.7% by volume, which corresponds to inefficient, standard, and very efficient dust shortwave absorption, respectively. To investigate the sensitivity of the position and intensity of the tropical rainbelt over Africa and its extension to the Arabian Peninsula to dust shortwave absorption, we have conducted ensembles of numerical simulations for each of the three dust absorptivity scenarios using a high resolution Atmospheric General Circulation Model (AGCM), GFDL\\'s High Resolution Atmospheric Model (HiRAM), at a spatial resolution of 25 km. We found that the strength and the latitudinal extent of the rainbelt are very sensitive to dust shortwave absorption, as well as circulations at various spatiotemporal scales that drive the climate of the region. Reference: Balkanski, Y., M. Schulz, T. Claquin, and S. Guibert (2007), Reevaluation of mineral aerosol radiative forcings suggests a better agreement with satellite and AERONET data, Atmos. Chem. Phys., 7, 81 - 95.

  8. $\\Sigma^- p$ emission rates in $K^-$ absorptions at rest on $^6$Li, $^7$Li, $^{9}$Be, $^{13}$C and $^{16}$O

    CERN Document Server

    Agnello, M; Bertani, M; Bonomi, G; Botta, E; Bregant, M; Bressani, T; Bufalino, S; Busso, L; Calvo, D; Camerini, P; Dalena, B; De Mori, F; D'Erasmo, G; Feliciello, A; Filippi, A; Fiore, E M; Fontana, A; Fujioka, H; Genova, P; Gianotti, P; Grion, N; Lucherini, V; Marcello, S; Morra, O; Nagae, T; Outa, H; Pantaleo, A; Paticchio, V; Piano, S; Rui, R; Simonetti, G; Wheadon, R; Zenoni, A

    2015-01-01

    An experimental study of the $K^-_{stop}A\\rightarrow \\Sigma^- p A'$ reaction on $A=^6$Li, $^7$Li, $^9$Be, $^{13}$C and $^{16}$O $p$-shell nuclei is presented. The data were collected by the FINUDA spectrometer operating at the DA$\\Phi$NE $\\phi$-factory (LNF-INFN, Italy). Emission rates for the reaction in the mentioned nuclei are measured and compared with the few existing data. The spectra of several observables are discussed; indications of Quasi-Free absorptions by a $(np)$ pair embedded in the $A$ nucleus can be obtained from the study of the missing mass distributions.

  9. Investigation of high-rate lithium-thionyl chloride cells

    Science.gov (United States)

    Hayes, Catherine A.; Gust, Steven; Farrington, Michael D.; Lockwood, Judith A.; Donaldson, George J.

    Chemical analysis of a commercially produced high-rate D-size lithium-thionyl cell was carried out, as a function of rate of discharge (1 ohm and 5 ohms), depth of discharge, and temperature (25 C and -40 C), using specially developed methods for identifying suspected minor cell products or impurities which may effect cell performance. These methods include a product-retrieval system which involves solvent extraction to enhance the recovery of suspected semivolatile minor chemicals, and methods of quantitative GC analysis of volatile and semivolatile products. The nonvolatile products were analyzed by wet chemical methods. The results of the analyses indicate that the predominant discharge reaction in this cell is 4Li + 2SOCl2 going to 4LiCl + S + SO2, with SO2 formation decreasing towards the end of cell life (7 to 12 Ah). The rate of discharge had no effect on the product distribution. Upon discharge of the high-rate cell at -40 C, one cell exploded, and all others exhibited overheating and rapid internal pressure rise when allowed to warm up to room temperature.

  10. HIGH RATES OF EVOLUTION PRECEDED THE ORIGIN OF BIRDS

    Science.gov (United States)

    Puttick, Mark N; Thomas, Gavin H; Benton, Michael J; Polly, P David

    2014-01-01

    The origin of birds (Aves) is one of the great evolutionary transitions. Fossils show that many unique morphological features of modern birds, such as feathers, reduction in body size, and the semilunate carpal, long preceded the origin of clade Aves, but some may be unique to Aves, such as relative elongation of the forelimb. We study the evolution of body size and forelimb length across the phylogeny of coelurosaurian theropods and Mesozoic Aves. Using recently developed phylogenetic comparative methods, we find an increase in rates of body size and body size dependent forelimb evolution leading to small body size relative to forelimb length in Paraves, the wider clade comprising Aves and Deinonychosauria. The high evolutionary rates arose primarily from a reduction in body size, as there were no increased rates of forelimb evolution. In line with a recent study, we find evidence that Aves appear to have a unique relationship between body size and forelimb dimensions. Traits associated with Aves evolved before their origin, at high rates, and support the notion that numerous lineages of paravians were experimenting with different modes of flight through the Late Jurassic and Early Cretaceous. PMID:24471891

  11. High frame rate measurements of semiconductor pixel detector readout IC

    Science.gov (United States)

    Szczygiel, R.; Grybos, P.; Maj, P.

    2012-07-01

    We report on high count rate and high frame rate measurements of a prototype IC named FPDR90, designed for readouts of hybrid pixel semiconductor detectors used for X-ray imaging applications. The FPDR90 is constructed in 90 nm CMOS technology and has dimensions of 4 mm×4 mm. Its main part is a matrix of 40×32 pixels with 100 μm×100 μm pixel size. The chip works in the single photon counting mode with two discriminators and two 16-bit ripple counters per pixel. The count rate per pixel depends on the effective CSA feedback resistance and can be set up to 6 Mcps. The FPDR90 can operate in the continuous readout mode, with zero dead time. Due to the architecture of digital blocks in pixel, one can select the number of bits read out from each counter from 1 to 16. Because in the FPDR90 prototype only one data output is available, the frame rate is 9 kfps and 72 kfps for 16 bits and 1 bit readout, respectively (with nominal clock frequency of 200 MHz).

  12. High frame rate measurements of semiconductor pixel detector readout IC

    Energy Technology Data Exchange (ETDEWEB)

    Szczygiel, R., E-mail: robert.szczygiel@agh.edu.pl [AGH University of Science and Technology, Department of Measurement and Instrumentation, Al. Mickiewicza 30, 30-059 Cracow (Poland); Grybos, P.; Maj, P. [AGH University of Science and Technology, Department of Measurement and Instrumentation, Al. Mickiewicza 30, 30-059 Cracow (Poland)

    2012-07-11

    We report on high count rate and high frame rate measurements of a prototype IC named FPDR90, designed for readouts of hybrid pixel semiconductor detectors used for X-ray imaging applications. The FPDR90 is constructed in 90 nm CMOS technology and has dimensions of 4 mm Multiplication-Sign 4 mm. Its main part is a matrix of 40 Multiplication-Sign 32 pixels with 100 {mu}m Multiplication-Sign 100 {mu}m pixel size. The chip works in the single photon counting mode with two discriminators and two 16-bit ripple counters per pixel. The count rate per pixel depends on the effective CSA feedback resistance and can be set up to 6 Mcps. The FPDR90 can operate in the continuous readout mode, with zero dead time. Due to the architecture of digital blocks in pixel, one can select the number of bits read out from each counter from 1 to 16. Because in the FPDR90 prototype only one data output is available, the frame rate is 9 kfps and 72 kfps for 16 bits and 1 bit readout, respectively (with nominal clock frequency of 200 MHz).

  13. Small cryptopredators contribute to high predation rates on coral reefs

    Science.gov (United States)

    Goatley, Christopher H. R.; González-Cabello, Alonso; Bellwood, David R.

    2017-03-01

    Small fishes suffer high mortality rates on coral reefs, primarily due to predation. Although studies have identified the predators of early post-settlement fishes, the predators of small cryptobenthic fishes remain largely unknown. We therefore used a series of mesocosm experiments with natural habitat and cryptobenthic fish communities to identify the impacts of a range of small potential predators, including several invertebrates, on prey fish populations. While there was high variability in predation rates, many members of the cryptobenthic fish community act as facultative cryptopredators, being prey when small and piscivores when larger. Surprisingly, we also found that smashing mantis shrimps may be important fish predators. Our results highlight the diversity of the predatory community on coral reefs and identify previously unknown trophic links in these complex ecosystems.

  14. Complex pulsing schemes for high frame rate imaging

    DEFF Research Database (Denmark)

    Misaridis, Thanassis; Fink, Mathias; Jensen, Jørgen Arendt

    2002-01-01

    High frame rate ultrasound imaging can be achieved by simultaneous transmission of multiple focused beams along different directions. However, image quality degrades by the interference among beams. An alternative approach is to transmit spherical waves of a basic short pulse with frequency coding...... with linear frequency modulation along the transducer elements, that cover the 70% fractional bandwidth of the 7 MHz transducer. The resulted images (after beamforming and matched filtering) show an axial resolution at the same order as in conventional pulse excitation and axial sidelobes down to -45 d......B. With the proposed imaging strategy of pulse train excitation, a whole image can be formed with only two emissions, making it possible to obtain high quality images at a frame rate of 20 to 25 times higher than that of conventional phased array imaging...

  15. Characteristics of Multiplexed Grooved Nozzles for High Flow Rate Electrospray

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyoung Tae; Kim, Woo Jin; Kim, Sang Soo [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2007-10-15

    The electrospray operated in the cone-jet mode can generate highly charged micro droplets in an almost uniform size at flow rates. Therefore, the multiplexing system which can retain the characteristics of the cone-jet mode is inevitable for the electrospray application. This experiment reports the multiplexed grooved nozzle system with the extractor. The effects of the grooves and the extractor on the performance of the electrospray were evaluated through experiments. Using the grooved nozzle, the stable cone-jet mode can be achieved at the each groove in the grooved mode. Furthermore, the number of nozzles per unit area is increased by the extractor. The multiplexing density is 12 jets per cm{sup 2} at 30 mm distance from the nozzle tip to the ground plate. The multiplexing system for the high flow rate electrospray is realized with the extractor which can diminish the space charge effect without sacrificing characteristics of the cone-jet mode.

  16. Distribution of streaming rates into high-redshift galaxies

    CERN Document Server

    Goerdt, Tobias; Dekel, Avishai; Teyssier, Romain

    2015-01-01

    We study the accretion along streams from the cosmic web into high-redshift massive galaxies using three sets of AMR hydro-cosmological simulations. We find that the streams keep a roughly constant accretion rate as they penetrate into the halo centre. The mean accretion rate follows the mass and redshift dependence predicted for haloes by the EPS approximation, dM / dt is proportional to Mvir^{1.25} (1 + z)^{2.5}. The distribution of the accretion rates can well be described by a sum of two Gaussians, the primary corresponding to "smooth inflow" and the secondary to "mergers". The same functional form was already found for the distributions of specific star formation rates in observations. The mass fraction in the smooth component is 60 - 90 %, insensitive to redshift or halo mass. The simulations with strong feedback show clear signs of re-accretion due to recycling of galactic winds. The mean accretion rate for the mergers is a factor 2 - 3 larger than that of the smooth component. The standard deviation o...

  17. System for time-resolved laser absorption spectroscopy and its application to high-power impulse magnetron sputtering

    Science.gov (United States)

    Adámek, P.; Olejníček, J.; Hubička, Z.; Čada, M.; Kment, Š.; Kohout, M.; Do, H. T.

    2017-02-01

    This paper deals with the development and construction of an apparatus for time-resolved tunable diode laser absorption spectroscopy (LAS) for the diagnostics of pulsed plasma. A detailed description of the extension of a progressive method of laser absorption spectroscopy in continuous regime to a direct triggering method of the time-resolved laser absorption spectroscopy (TR-LAS) is presented. The main advantage of the developed method is its capability to measure the time evolution of the whole absorption profile with a preset time resolution, which can be less than 1 μs. Therefore, the presented method of repetitive sampling applied on LAS in plasma processes is capable of simultaneous measurement of the density and kinetic temperature of selected particles. Its appropriate applications are to periodical processes in technological plasma, namely pulsed plasma discharges. The developed method of TR-LAS was applied to measurements of the temporal evolution of density and kinetic temperature of argon metastable species during high-power impulse magnetron sputtering of titanium and titanium dioxide thin films.

  18. Direct determination of fluorine in niobium oxide using slurry sampling electrothermal high-resolution continuum source molecular absorption spectrometry

    Science.gov (United States)

    Huang, Mao Dong; Becker-Ross, Helmut; Okruss, Michael; Geisler, Sebastian; Florek, Stefan; Richter, Silke; Meckelburg, Angela

    Aiming for a round-robin test, a new method for the direct determination of fluorine in niobium oxide has been developed. It is based on the use of high-resolution molecular absorption spectra of calcium mono-fluoride (CaF) generated in the graphite tube, combined with the slurry sampling technique. The absorption measurement was performed at the 606.44 nm CaF rotational line. By using graphite tubes with zirconium carbide (ZrC) modified platform, the molecular absorption sensitivity of CaF has been improved by a factor of 20, and no additional chemical modifier was necessary. Generally, non-spectral interferences were observed in the presence of HCl, H2SO4, and H3PO4. For HCl, additional spectral interference occurred due to an overlap of the absorption spectra of CaF and CaCl. However, due to the absence of these mentioned substances in the current material, such interferences do not exist for this application. The characteristic mass found for the CaF 606.44 nm line was 0.1 ng; the limit of detection was 5 mg fluorine per kg solid sample (3σ criterion). The results obtained by the method were within the range of certified values. Comparing to the classical method such as the pyrohydrolysis-photometric method, the developed new method showed clear advantages regarding sensitivity and specificity. The time requirement for one sample analysis was strongly shortened from several hours to only some minutes.

  19. High-rate diamond deposition by microwave plasma CVD

    Science.gov (United States)

    Li, Xianglin

    In this dissertation, the growth of CVD (Chemical Vapor Deposition) diamond thin films is studied both theoretically and experimentally. The goal of this research is to deposit high quality HOD (Highly Oriented Diamond) films with a growth rate greater than 1 mum/hr. For the (100)-oriented HOD films, the growth rate achieved by the traditional process is only 0.3 mum/hr while the theoretical limit is ˜0.45 mum/hr. This research increases the growth rate up to 5.3 mum/hr (with a theoretical limit of ˜7 mum/hr) while preserving the crystal quality. This work builds a connection between the theoretical study of the CVD process and the experimental research. The study is extended from the growth of regular polycrystalline diamond to highly oriented diamond (HOD) films. For the increase of the growth rate of regular polycrystalline diamond thin films, a scaling growth model developed by Goodwin is introduced in details to assist in the understanding of the MPCVD (Microwave Plasma CVD) process. Within the Goodwin's scaling model, there are only four important sub-processes for the growth of diamond: surface modification, adsorption, desorption, and incorporation. The factors determining the diamond growth rate and film quality are discussed following the description of the experimental setup and process parameters. Growth rate and crystal quality models are reviewed to predict and understand the experimental results. It is shown that the growth rate of diamond can be increased with methane input concentration and the amount of atomic hydrogen (by changing the total pressure). It is crucial to provide enough atomic hydrogen to conserve crystal quality of the deposited diamond film. The experimental results demonstrate that for a fixed methane concentration, there is a minimum pressure for growth of good diamond. Similarly, for a fixed total pressure, there is a maximum methane concentration for growth of good diamond, and this maximum methane concentration increases

  20. High Strain Rate Experiments of Energetic Material Binder

    OpenAIRE

    Rangel Mendoza, Roberto; Harr, Michael; Chen, Weinong

    2016-01-01

    Energetic materials, in particular HMX, is widely used in many applications as polymer bonded explosives (PBX) and rocket propellant. However, when damaged, HMX is known to be an unstable substance which renders it a hazardous material and in some cases unreliable. Finding critical mechanical conditions at high rates that render various forms of energetic materials as unreliable would be vital to understand the effects that vibrations and compression forces have on energetic materials. A bett...