WorldWideScience

Sample records for qso absorption systems

  1. Cosmological Evolution of QSO Absorption Systems

    Science.gov (United States)

    Stengler-Larrea, Erik

    1995-08-01

    First, the evolution with cosmic time of the hydrogen clouds which produce the Lyman-alpha absorption lines is studied in dependence on the strength of these lines. From the analysis it is concluded that the results show no evidence of a dependence in the sense of stronger lines evolving faster, although for the resolution at which the used observations were done, it can not be ruled out. Within the same analysis, a distribution of the Doppler parameter of the lines was obtained, with large values and a wide spread. This parameter being an indicator of the gas temperature, this result is in accordance with high temperatures and, consequently, large ionised fractions and a large fraction of the baryonic matter of the universe being associated with these clouds. However, recent high resolution studies seem to reveal that much lower temperatures are characteristic of the clouds. The main content of this thesis, however, focuses on the redshift evolution of the absorbing systems producing absorption at the Lyman limit and of the amount of CIV producing CIV absorption lines. Regarding the CIV absorbers, previous predictions on the effects underlying their redshift distribution pointed to an increase with redshift of the absorbing column densities. In this thesis the first direct measurements of such column densities by profile fitting of a large number of absorption systems (73) are presented, confirming the predictions of a decrease of at least a factor of 3 between z=1.5 and z=3.0. The study on the evolution of Lyman limit absorption systems (LLSs) puts an end to previous discrepancies between the results of different groups. Both a smooth single power law dependence of the LLS number density on redshift indicating no evolution in number density for 0.4 Team of the HST Key Project on QSO absorption lines, and in particular to estimate the necessary exposure times, the magnitudes of several of these objects had to be re-measured. The acquisition of their images and the

  2. The low-ion QSO absorption-line systems

    International Nuclear Information System (INIS)

    Lanzetta, K.M.

    1988-01-01

    Various techniques are used to investigate the class of QSO absorption-line systems that exhibit low-ion absorption lines. Four separate investigations are conducted as follows: Spectroscopy of 32 QSOs at red wavelengths is presented and used to investigate intermediate-redshift MgII absorption. A total of 22 Mg II doublets are detected, from which properties of the Mg II absorbers are derived. Marginal evidence for intrinsic evolution of the number density of the Mg II absorbers with redshift is found. The data are combined with previous observations of C IV and C II seen in the same QSOs at blue wavelengths, and the properties of Mg II- and C IV-selected systems are compared. A sample is constructed of 129 QSOs for which are available published data suitable for detecting absorption-line systems that are optically thick to Lyman continuum radiation. A total of 53 such Lyman-limit systems are found, from which properties of the Lyman-limit systems are derived. It is found that the rate of incidence of the systems does not strongly evolved with redshift. This result is contrasted with the evolution found previously for systems selected on the basis of Mg II absorption. Spectroscopy at red wavelengths of eight QSOs with known damped Lyα absorption systems is presented. Spectroscopic and spectrophotometric observations aimed at detecting molecular hydrogen and dust in the z = 2.796 damped Lyα absorber toward Q1337 + 113 are presented

  3. Cosmological implications of the redshift distribution of QSO absorption systems

    International Nuclear Information System (INIS)

    Khare-Joshi, P.; Perry, J.J.

    1982-01-01

    We have used the observational data on QSO absorption redshifts, as compiled by Perry, Burbidge and Burbidge (1978) (hereafter PB 2 ), Drew (1978) and Weyman et al. (1979) (hereafter W 2 PT), to study various selection effects likely to affect the distribution of absorption redshifts and, then to determine the probable number distribution of absorbers per redshift interval of 0.1, as a function of z. The distribution obtained, assuming all the observed absorption to be intervening, is found to be statistically incompatible with the redshift distribution of galaxies with constant cross-section for any Friedman cosmology with zero cosmological constant and q 0 >= 0. Therefore, in order to eliminate the absorption systems which are plausibly intrinsic, we have applied the criterion suggested by W 2 PT and by the analysis of the distribution of absorption systems as a function of the relative velocity between the emitting and the absorbing gas, for the PB 2 data set; to wit, we have analysed the distributions obtained by assuming that those systems with relative velocity greater than 0.02 c, 0.02 c but not equal to 0.1 c to 0.11 c and 0.06 c respectively, or those systems without O VI and N V lines, are produced by the intervening galaxies. The results are discussed. (author)

  4. Observations of nickel, chromium, and zinc in QSO absorption-line systems

    International Nuclear Information System (INIS)

    Meyer, D.M.; Roth, K.C.

    1990-01-01

    New observations of Ni II, Cr II, and Zn II in several damped Ly-alpha QSO absorption-line systems at z about 2 are presented. Using the N(Zn II)/N(H I) ratio as a probe of the metallicity and N(Cr II)/N(Zn II) as a measure of the dust content, it is found that the heavy-element abundances in the z = 1.921 system toward the QSO 2206-199N are 20 percent solar and that the dust-to-gas ratio is 11 percent of the Galactic disk value. The observations of these species in the z = 2.309 system toward PHL 957 yield a more extreme metallicity (4 percent solar) and dust-to-gas ratio (3 percent Galactic). In addition, a depletion of Ni in the z = 2.039 absorber toward PKS 0458 - 020 and an absence of C I absorption in the z about 2 damped systems toward 1215 + 333 and 2359 - 022 are found which are consistent with a lack of dust. Among the four damped systems whose Ni, Cr, and Zn abundances have been examined quantitatively to date, all show convincing evidence of much lower metallicities and dust content than the Galactic disk. The implications of these results with regard to the interpretation of the high-redshift damped Ly-alpha systems as an evolving population of young galaxies are discussed. 41 refs

  5. The dust, nebular emission, and dependence on QSO radio properties of the associated Mg II absorption line systems

    International Nuclear Information System (INIS)

    Khare, Pushpa; Daniel, Vanden Berk; Rahmani, Hadi; York, Donald G.

    2014-01-01

    We studied dust reddening and [O II] emission in 1730 Mg II associated absorption systems (AAS; relative velocity with respect to QSOs, ≤3000 km s –1 ; in units of velocity of light, β, ≤0.01) with 0.4 ≤z abs ≤ 2 in the Sloan Digital Sky Survey DR7, focusing on their dependence on the radio and other QSO properties. We used control samples, several with matching radio properties, to show that (1) AAS in radio-detected (RD) QSOs cause 2.6 ± 0.2 times higher dust extinction than those in radio-undetected (RUD) ones, which in turn cause 2.9 ± 0.7 times the dust extinction in the intervening systems; (2) AAS in core-dominated QSOs cause 2.0 ± 0.1 times higher dust extinction than those in lobe-dominated QSOs; (3) the occurrence of AAS is 2.1 ± 0.2 times more likely in RD QSOs than in RUD QSOs and 1.8 ± 0.1 time more likely in QSOs having black holes with masses larger than 1.23 × 10 9 M ☉ than in those with lower-mass black holes; and (4) there is excess flux in [O II]λ3727 emission in the composite spectra of the AAS samples compared with those of the control samples, which is at the emission redshift. The presence of AAS enhances the O II emission from the active galactic nucleus and/or the host galaxy. This excess is similar for both RD and RUD samples and is 2.5 ± 0.4 times higher in lobe-dominated samples than in core-dominated samples. The excess depends on the black hole mass and Eddington ratio. All these point to the intrinsic nature of the AAS except for the systems with z abs > z em , which could be infalling galaxies.

  6. The dust, nebular emission, and dependence on QSO radio properties of the associated Mg II absorption line systems

    Energy Technology Data Exchange (ETDEWEB)

    Khare, Pushpa [CSIR Emeritus Scientist, IUCAA, Ganeshkhind, Pune 411007 (India); Daniel, Vanden Berk [Physics Department, St. Vincent College, Latrobe, PA 15650 (United States); Rahmani, Hadi [School of Astronomy, Institute for Research in Fundamental Sciences (IPM), P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of); York, Donald G., E-mail: pushpakhare@gmail.com [Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL 60637 (United States)

    2014-10-10

    We studied dust reddening and [O II] emission in 1730 Mg II associated absorption systems (AAS; relative velocity with respect to QSOs, ≤3000 km s{sup –1}; in units of velocity of light, β, ≤0.01) with 0.4 ≤z {sub abs} ≤ 2 in the Sloan Digital Sky Survey DR7, focusing on their dependence on the radio and other QSO properties. We used control samples, several with matching radio properties, to show that (1) AAS in radio-detected (RD) QSOs cause 2.6 ± 0.2 times higher dust extinction than those in radio-undetected (RUD) ones, which in turn cause 2.9 ± 0.7 times the dust extinction in the intervening systems; (2) AAS in core-dominated QSOs cause 2.0 ± 0.1 times higher dust extinction than those in lobe-dominated QSOs; (3) the occurrence of AAS is 2.1 ± 0.2 times more likely in RD QSOs than in RUD QSOs and 1.8 ± 0.1 time more likely in QSOs having black holes with masses larger than 1.23 × 10{sup 9} M {sub ☉} than in those with lower-mass black holes; and (4) there is excess flux in [O II]λ3727 emission in the composite spectra of the AAS samples compared with those of the control samples, which is at the emission redshift. The presence of AAS enhances the O II emission from the active galactic nucleus and/or the host galaxy. This excess is similar for both RD and RUD samples and is 2.5 ± 0.4 times higher in lobe-dominated samples than in core-dominated samples. The excess depends on the black hole mass and Eddington ratio. All these point to the intrinsic nature of the AAS except for the systems with z {sub abs} > z {sub em}, which could be infalling galaxies.

  7. Damped Lyα system toward QSO1854+116: A new type of absorber?

    Directory of Open Access Journals (Sweden)

    Ćirković M.M.

    1999-01-01

    Full Text Available A puzzle of the low-redshift damped Lyα absorption system toward QSO 1854+116 is presented. Problems which conventional intepretation of damped Lyα systems encounters in this case are sketched and a possible explanation, based on transience of the phenomenon, is suggested. It is shown that the detailed Hα tomography can observationally resolve the controversy in the very near future.

  8. Interstellar Gas-phase Element Depletions in the Small Magellanic Cloud: A Guide to Correcting for Dust in QSO Absorption Line Systems

    Energy Technology Data Exchange (ETDEWEB)

    Jenkins, Edward B. [Princeton University Observatory, Princeton, NJ 08544-1001 (United States); Wallerstein, George, E-mail: ebj@astro.princeton.edu, E-mail: walleg@u.washington.edu [University of Washington, Seattle, Dept. of Astronomy, Seattle, WA 98195-1580 (United States)

    2017-04-01

    We present data on the gas-phase abundances for 9 different elements in the interstellar medium of the Small Magellanic Cloud (SMC), based on the strengths of ultraviolet absorption features over relevant velocities in the spectra of 18 stars within the SMC. From this information and the total abundances defined by the element fractions in young stars in the SMC, we construct a general interpretation on how these elements condense into solid form onto dust grains. As a group, the elements Si, S, Cr, Fe, Ni, and Zn exhibit depletion sequences similar to those in the local part of our Galaxy defined by Jenkins. The elements Mg and Ti deplete less rapidly in the SMC than in the Milky Way, and Mn depletes more rapidly. We speculate that these differences might be explained by the different chemical affinities to different existing grain substrates. For instance, there is evidence that the mass fractions of polycyclic aromatic hydrocarbons in the SMC are significantly lower than those in the Milky Way. We propose that the depletion sequences that we observed for the SMC may provide a better model for interpreting the element abundances in low-metallicity Damped Lyman Alpha (DLA) and sub-DLA absorption systems that are recorded in the spectra of distant quasars and gamma-ray burst afterglows.

  9. PROPERTIES OF QSO METAL-LINE ABSORPTION SYSTEMS AT HIGH REDSHIFTS: NATURE AND EVOLUTION OF THE ABSORBERS AND NEW EVIDENCE ON ESCAPE OF IONIZING RADIATION FROM GALAXIES

    Energy Technology Data Exchange (ETDEWEB)

    Boksenberg, Alec [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge, CB3 0HA (United Kingdom); Sargent, Wallace L. W., E-mail: boksy@ast.cam.ac.uk [Division of Physics, Mathematics, and Astronomy, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 (United States)

    2015-05-15

    Using Voigt-profile-fitting procedures on Keck High Resolution Spectrograph spectra of nine QSOs, we identify 1099 C IV absorber components clumped in 201 systems outside the Lyman forest over 1.6 ≲ z ≲ 4.4. With associated Si IV, C II, Si II  and N V where available, we investigate the bulk statistical and ionization properties of the components and systems and find no significant change in redshift for C IV and Si IV while C II, Si II  and N V change substantially. The C IV components exhibit strong clustering, but no clustering is detected for systems on scales from 150 km s{sup –1} out to 50,000 km s{sup –1}. We conclude that the clustering is due entirely to the peculiar velocities of gas present in the circumgalactic media of galaxies. Using specific combinations of ionic ratios, we compare our observations with model ionization predictions for absorbers exposed to the metagalactic ionizing radiation background augmented by proximity radiation from their associated galaxies and find that the generally accepted means of radiative escape by transparent channels from the internal star-forming sites is spectrally not viable for our stronger absorbers. We develop an active scenario based on runaway stars with resulting changes in the efflux of radiation that naturally enable the needed spectral convergence, and in turn provide empirical indicators of morphological evolution in the associated galaxies. Together with a coexisting population of relatively compact galaxies indicated by the weaker absorbers in our sample, the collective escape of radiation is sufficient to maintain the intergalactic medium ionized over the full range 1.9 < z ≲ 4.4.

  10. Possible evidence for a variable fine-structure constant from QSO absorption lines: motivations, analysis and results

    Science.gov (United States)

    Murphy, M. T.; Webb, J. K.; Flambaum, V. V.; Dzuba, V. A.; Churchill, C. W.; Prochaska, J. X.; Barrow, J. D.; Wolfe, A. M.

    2001-11-01

    An experimental search for variation in the fundamental coupling constants is strongly motivated by modern high-energy physics theories. Comparison of quasar (QSO) absorption-line spectra with laboratory spectra provides a sensitive probe for variability of the fine-structure constant, α, over cosmological time-scales. We have previously developed and applied a new method providing an order-of-magnitude gain in precision over previous optical astrophysical constraints. Here we extend that work by including new quasar spectra of damped Lyman-α absorption systems. We also reanalyse our previous lower-redshift data and confirm our initial results. The constraints on α come from simultaneous fitting of absorption lines of subsets of the following species: Mgi, Mgii, Alii, Aliii, Siii, Crii, Feii, Niii and Znii. We present a detailed description of our methods and results based on an analysis of 49 quasar absorption systems (towards 28 QSOs) covering the redshift range [formmu2]0.5quote above is the raw value, not corrected for any of these systematic effects. The only significant systematic effects so far identified, if removed from our data, would lead to a more significant deviation of [formmu5]Δα/α from zero.

  11. Size of the z = 0.437 H I absorption region toward the QSO 3C 196

    International Nuclear Information System (INIS)

    Brown, R.L.; Benson, J.M.; Broderick, J.J.; Johnston, K.J.; Mitchell, K.J.

    1988-01-01

    VLBI spectral line observations made at the frequency of the z = 0.437 H I absorption line toward the extended radio QSO 3C 196 demonstrate that the absorption does not occur against the more compact continuum structure in this object. Apparently the H I absorption line results from absorption of the lower brightness continuum emission by an intervening cloud with an angular diameter which must be greater than 0.63 arcsec. For a standard cosmology, this corresponds to a linear extent greater than 2.25 kpc. For a spherical cloud, the mass of absorbing gas is near 7 x 10 to the 7th solar masses. Thus this particular QSO absorbing cloud is surprisingly large and massive. 22 references

  12. PG 1700 + 518 - a low-redshift, broad absorption line QSO

    International Nuclear Information System (INIS)

    Pettini, M.; Boksenberg, A.

    1985-01-01

    The first high-resolution optical spectra and lower resolution UV spectra of PG 1700 + 518, the only known broad-absorption-line (BAL) QSO at low emission redshift (0.288) are presented. The optical data were obtained with the Isaac Newton Telescope on the island of La Palma and the UV data with the International Ultraviolet Explorer satellite. The outstanding feature of the optical spectrum is a strong, broad Mg II absorption trough, detached from the Mg II emission line and indicative of ejection velocities of between 7000 and 18,000 km/s. Also detected were narrow (FWHM = 350 km/s) Mg II absorption lines at absolute z = 0.2698, which are probably related to the mass ejection phenomenon. It is concluded that the emission-line spectrum is similar to that of other low-redshift QSOs although there are some obvious differences from typical BAL QSOs, most notably in the unusually low level of ionization of both emission-line and broad absorption line gas. 21 references

  13. Absorption lines, Faraday rotation, and magnetic field estimates for QSO absorption-line clouds

    International Nuclear Information System (INIS)

    Kronberg, P.P.; Perry, J.J.

    1982-01-01

    We have estimated the extragalactic component of Faraday rotation for a sample of 37 QSOs for which there is good absorption line data, which we have also analyzed. Statistical evidence is presented which suggests that we have isolated a component of Faraday rotation which is occurring in the absorption clouds of some QSOs

  14. The distribution of QSO redshift (1 + Zi)/(1 + Zj)

    International Nuclear Information System (INIS)

    Drew, J.E.

    1978-01-01

    Following a general survey conducted by Burbidge and Burbidge (1975) to consider the case for line-Locking in QSO spectra and a later statistical study by Sargent and Boroson (1977), the method of the latter and the QSO sample of the former are investigated further. The results of Sargent and Boroson are confirmed and it is noted that uneven spectral resolution in the QSO sample has over-emphasized the 1.11 peak in the combined emission-absorption and absorption-absorption redshift ratio distribution. The sample is extended to include recently observed QSOs and the absorption redshift selection is designed to exclude all but the most certain absorption redshifts. Care is taken in the selection procedure to ensure that there is no personal bias either way regarding the line-locking hypothesis. A peak is found to occur in the distribution of (1 + sub(Zem))/(1 + sub(Zabs)), given by the extended sample, at 1.11 with a chance probability of 3 x 10 -5 . It is concluded that the present data suggests the peak is real and that a physical interaction between the QSO emission line regions and absorption systems concerned is required to explain its occurrence. However, the nature of the interaction is as yet unknown and there are difficulties with the possibility of line-locking. (orig.) [de

  15. A QSO with precessing jets: 2300 - 189

    International Nuclear Information System (INIS)

    Hunstead, R.W.; Murdoch, H.S.; Phillips, M.M.

    1984-01-01

    The QSO 2300-189 (z = 0.1287) is found to have a faint companion galaxy at the same redshift. The separation is 6.8 arcsec on the sky. A spectrum of the fuzz around the QSO shows absorption features typical of late-type stars, which argues for its occurence in a normal disc or E galaxy. Radio maps obtained with the VLA at 1465 MHz and 4885 MHz show inversion (or S-shaped) symmetry, which is explained as due to the ejection of jets along an axis which is precessing, probably due to the tidal influence of the nearby galaxy. Several kinematic parameters are deduced including an upper limit for the jet velocity. Further support for tidal interaction comes from the detection of extensive region of low-brightness optical emission in the vicinity of the QSO. (author)

  16. The z = 1.6748 C I Absorber Toward the QSO PKS 1756+237

    Science.gov (United States)

    Roth, Katherine C.; Bauer, James M.; Jim, Kevin T. C.

    We have detected C I ground-state absorption at zabs = 1.6748 toward the QSO PKS 1756+237 (zem = 1.725), making this only the fourth known C I QSO absorber. The absence of excited-state fine-structure C I lines is compatible with the redshifted Cosmic Microwave Background Radiation at an expected temperature of TCMBR (1+z) = 7.291 K (Mather et al. 1994, ApJ, 354, L37). We find a 2 σ upper-limit on the C I excitation temperature of Tex <= 7.73(+0.53, -0.46) K (Roth & Bauer 1999, ApJ, submitted). Our Keck HIRES spectra (8.3 km s-1 FWHM) obtained in May 1997 also reveal the existence of Ni II and Fe II lines with a sub-solar Ni/Fe abundance ratio, presumably indicative of dust. We have obtained deep, high resolution (0.3'' FWHM) images in H+K' with the UH 2.2m Tip-Tilt system of the QSO field in order to identify the system responsible for the zabs = 1.6748 absorption. We detect two faint candidate systems within 1.5'' and 3'' (≅ 15 and 30 kpc, Hcirc = 65) of the QSO.

  17. Absorption heat pump system

    Science.gov (United States)

    Grossman, G.

    1982-06-16

    The efficiency of an absorption heat pump system is improved by conducting liquid from a second stage evaporator thereof to an auxiliary heat exchanger positioned downstream of a primary heat exchanger in the desorber of the system.

  18. Cosmic Metal Production and the Contribution of QSO Absorption Systems to the Ionizing Background

    Science.gov (United States)

    Madau, Piero; Shull, J. Michael

    1996-01-01

    The recent discovery by Cowie et al. (1995) and Tytler et al. (1995) of metals in the Ly alpha clouds shows that the intergalactic medium (IGM) at high redshift is contaminated by the products of stars and suggests that ionizing photons from massive star formation may be a significant contributor to the UV background radiation at early epochs. We assess the validity of the stellar photoionization hypothesis. Based on recent computations of metal yields and 0-star Lyman continuum (Lyc) fluxes, we find that 0.2 percent of the rest-mass energy of the metals produced is radiated as Lyc. By modeling the transfer of ionizing radiation through the IGM and the rate of chemical enrichment, we demonstrate that the background intensity of photons at 1 ryd that accompanies the production of metals in the Ly alpha forest clouds may be significant, approaching 0.5 x 10(exp -21) ergs cm squared s(-1) Hz(-1) sr(-1) at z approximately equals 3 if the Lyc escape fraction is greater than of equal to 0.25. Together with quasars, massive stars could then, in principle, provide the hydrogen and helium Lyc photons required to ionize the universe at high redshifts. We propose that observations of the He2 Gunn-Peterson effect and of the metal ionization states of the Ly alpha forest and Lyman-limit absorbers should show the signature of a stellar spectrum. We also note that the stellar photoionization model fails if a large fraction of the UV radiation emitted from stars cannot escape into the IGM, as suggested by the recent Hopkins Ultraviolet Telescope observations by Leitherer et al. (1995) of low-redshift starburst galaxies, or if most of the metals observed at z is approximately 3 were produced at much earlier epochs.

  19. QSO evolution in the interaction model

    International Nuclear Information System (INIS)

    De Robertis, M.

    1985-01-01

    QSO evolution is investigated according to the interaction hypothesis described most recently by Stockton (1982), in which activity results from an interaction between two galaxies resulting in the transfer of gas onto a supermassive black hole (SBH) at the center of at least one participant. Explicit models presented here for interactions in cluster environments show that a peak QSO population can be formed in this way at zroughly-equal2--3, with little activity prior to this epoch. Calculated space densities match those inferred from observations for this epoch. Substantial density evolution is expected in such models, since, after virialization, conditions in the cores of rich clusters lead to the depletion of gas-rich systems through ram-pressure stripping. Density evolution parameters of 6--12 are easily accounted for. At smaller redshifts, however, QSOs should be found primarily in poor clusters or groups. Probability estimates provided by this model are consistent with local estimates for the observed number of QSOs per interaction. Significant luminosity-dependent evolution might also be expected in these models. It is suggested that the mean SBH mass increases with lookback time, leading to a statistical brightening with redshift. Undoubtedly, both forms of evolution contribute to the overall QSO luminosity function

  20. QSO Pairs across Active Galaxies

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... Several QSO pairs have been reported and their redshifts determined, where the two objects in each pair are located across an active galaxy. The usually accepted explanation of such occurrences is that the pair is ejected from the parent galaxy. Currently interpreted redshifted spectra for both the QSOs ...

  1. MISALIGNMENT OF THE JET AND THE NORMAL TO THE DUSTY TORUS IN THE BROAD ABSORPTION LINE QSO FIRST J155633.8+351758

    International Nuclear Information System (INIS)

    Reynolds, Cormac; Punsly, Brian; O'Dea, Christopher P.

    2013-01-01

    We performed Very Long Baseline Array observations of the broad absorption line quasar FIRST J155633.8+351758, ''the first radio loud BALQSO''. Our observations at 15.3 GHz partially resolved a secondary component at position angle (P.A.) ≈35°. We combine this determination of the radio jet projection on the sky plane, with the constraint that the jet is viewed within 14.°3 of the line of sight (as implied by the high variability brightness temperature) and with the P.A. of the optical/UV continuum polarization in order to study the quasar geometry. Within the context of the standard model, the data indicates a ''dusty torus'' (scattering surface) with a symmetry axis tilted relative to the accretion disk normal and a polar broad absorption line outflow aligned with the accretion disk normal. We compare this geometry to that indicated by the higher resolution radio data, brightness temperature, and optical/UV continuum polarization P.A. of a similar high optical polarization BALQSO, Mrk 231. A qualitatively similar geometry is found in these two polar BALQSOs; the continuum polarization is determined primarily by the tilt of the dusty torus

  2. Optical absorption measurement system

    International Nuclear Information System (INIS)

    Draggoo, V.G.; Morton, R.G.; Sawicki, R.H.; Bissinger, H.D.

    1989-01-01

    This patent describes a non-intrusive method for measuring the temperature rise of optical elements under high laser power optical loading to determine the absorption coefficient. The method comprises irradiating the optical element with a high average power laser beam, viewing the optical element with an infrared camera to determine the temperature across the optical element and calculating the absorption of the optical element from the temperature

  3. Absorption-heat-pump system

    Science.gov (United States)

    Grossman, G.; Perez-Blanco, H.

    1983-06-16

    An improvement in an absorption heat pump cycle is obtained by adding adiabatic absorption and desorption steps to the absorber and desorber of the system. The adiabatic processes make it possible to obtain the highest temperature in the absorber before any heat is removed from it and the lowest temperature in the desorber before heat is added to it, allowing for efficient utilization of the thermodynamic availability of the heat supply stream. The improved system can operate with a larger difference between high and low working fluid concentrations, less circulation losses, and more efficient heat exchange than a conventional system.

  4. A new detection of an UFO in the X-ray spectrum of a lensed QSO

    Science.gov (United States)

    Dadina, M.

    2017-10-01

    The discovery of the "M_{SMBH}-σ relation" indicated that a connection between the central black-hole and the hosting galaxies acted during the cosmic time. With the discovery in X-rays of the ultra-fast outflows in nearby AGN, we have most probably probed one of the ingredients that are needed to build-up this mechanism. At high-z, however, such measurements were possible only in an handful of objects and this was possible mainly for the presence of gravitational lenses that magnified otherwise X-ray weak QSO. Following this, we proposed a program to use XMM-Newton and gravitational lenses as telescopes to point bright, lensed and distant QSO to characterize in detail their X-ray spectrum and to detect blushifted absorption lines at E˜7-10 keV (rest frame). Here we present the preliminary results obtained for the z=2.64 QSO MG J0414+0534.

  5. Intervening O vi Quasar Absorption Systems at Low Redshift: A Significant Baryon Reservoir.

    Science.gov (United States)

    Tripp; Savage; Jenkins

    2000-05-01

    Far-UV echelle spectroscopy of the radio-quiet QSO H1821+643 (zem=0.297), obtained with the Space Telescope Imaging Spectrograph (STIS) at approximately 7 km s-1 resolution, reveals four definite O vi absorption-line systems and one probable O vi absorber at 0.15quasar in redshift; these are likely intervening systems unrelated to the background QSO. In the case of the strong O vi system at zabs=0.22497, multiple components are detected in Si iii and O vi as well as H i Lyman series lines, and the differing component velocity centroids and b-values firmly establish that this is a multiphase absorption system. A weak O vi absorber is detected at zabs=0.22637, i.e., offset by approximately 340 km s-1 from the zabs=0.22497 system. Lyalpha absorption is detected at zabs=0.22613, but no Lyalpha absorption is significantly detected at 0.22637. Other weak O vi absorbers at zabs=0.24531 and 0.26659 and the probable O vi system at 0.21326 have widely diverse O vi/H i column density ratios with N(O vi)/N(H i) ranging from systems is Omegab(Ovi&parr0; greater, similar0.0008 h-175. With an assumed metallicity of 1/10 solar and a conservative assumption that the fraction of oxygen in the O vi ionization stage is 0.2, we obtain Omegab(Ovi&parr0; greater, similar0.004 h-175. This is comparable to the combined cosmological mass density of stars and cool gas in galaxies and X-ray-emitting gas in galaxy clusters at low redshift.

  6. Spectrophotometry of the double QSO, 0957+561

    International Nuclear Information System (INIS)

    Wills, B.J.; Wills, D.

    1980-01-01

    We report new spectrophotometry of the double QSO, 0957+561, and show that the absorption line region in each light path is very similar in redshift (Δv +- 14 km s -1 rms), in column density of Fe + (approx.3 x 10 14 cm -2 ), and in velocity dispersion (approx.40 km s -1 ). The simplest interpretation of these results is a very massive object deflecting the light from a more distant QSO. Based on this hypothesis we find that the differences between the emission line and continuum spectra may be explained by differential reddening, implying a reddening-corrected flux ratio B/Aapprox. =2--4. This ratio is different from that found at radio wavelengths (0.7 at 6 cm), but can be explained, based on the gravitational lens hypothesis, by different flux variability at radio and optical wavelengths; however, we have found no evidence for optical variability. Another difficulty may be that a point-mass gravitational lens would need to have a mass-to-light ratio greater than 1000, if it is closer than z=0.4; at larger distances its mass would be very large (approx.10 14 M/sub sun/ at z=1.2). Observations obtained so far might be explained if two massive QSOs are actually closer together than appear to be, as a result of mutual gravitational deflection of the light. 1

  7. Uniform semiclassical approximation for absorptive scattering systems

    International Nuclear Information System (INIS)

    Hussein, M.S.; Pato, M.P.

    1987-07-01

    The uniform semiclassical approximation of the elastic scattering amplitude is generalized to absorptive systems. An integral equation is derived which connects the absorption modified amplitude to the absorption free one. Division of the amplitude into a diffractive and refractive components is then made possible. (Author) [pt

  8. Spectrophotometry of the QSO NRAO 530

    International Nuclear Information System (INIS)

    Junkkarinen, V.

    1984-01-01

    Spectrophotometry of the QSO NRAO 530 with the KPNO Cryogenic Camera is reported. A redshift of 0.902 is determined from the H-beta, H-gamma, and 3727 A forbidden O II emission lines, confirming a redshift that had been based on a single line, the 2798 A Mg II. The H-beta equivalent is smaller than in normal QSOs, which may be characteristic of optically variable QSOs. 16 references

  9. PHL 6625: A Minor Merger-associated QSO Behind NGC 247

    Energy Technology Data Exchange (ETDEWEB)

    Tao, Lian; Feng, Hua [Department of Engineering Physics, Tsinghua University, Beijing 100084 (China); Shen, Yue; Liu, Xin [Department of Astronomy, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States); Ho, Luis C. [Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100087 (China); Ge, Junqiang [National Astronomical Observatories, Chinese Academy of Sciences, 20A Datun Road, Chaoyang District, Beijing 100012 (China); Kaaret, Philip [Department of Physics and Astronomy, University of Iowa, Iowa City, IA 52242 (United States); Mao, Shude [Center for Astrophysics, Tsinghua University, Beijing 100084 (China)

    2017-06-01

    PHL 6625 is a luminous quasi-stellar object (QSO) at z = 0.3954 located behind the nearby galaxy NGC 247 ( z = 0.0005). Hubble Space Telescope observations revealed an arc structure associated with it. We report on spectroscopic observations with the Very Large Telescope and multiwavelength observations from the radio to the X-ray band for the system, suggesting that PHL 6625 and the arc are a close pair of merging galaxies, instead of a strong gravitational lens system. The QSO host galaxy is estimated to be (4–28) × 10{sup 10} M {sub ☉} and the mass of the companion galaxy is estimated to be M {sub *} = (6.8 ± 2.4) × 10{sup 9} M {sub ☉}, suggesting that this is a minor merger system. The QSO displays typical broad emission lines, from which a black hole mass of about (2–5) × 10{sup 8} M {sub ☉} and an Eddington ratio of about 0.01–0.05 can be inferred. The system represents an interesting and rare case where a QSO is associated with an ongoing minor merger, analogous to Arp 142.

  10. Systemic Absorption of Nanomaterials by Oral Exposure

    DEFF Research Database (Denmark)

    Binderup, Mona-Lise; Bredsdorff, Lea; Beltoft, Vibe Meister

    This report and accompanying database systematically evaluates the reliability and relevance of the existing scientific literature regarding systemic absorption of nanomaterials by oral exposure and makes specific recommendations for future testing approaches.......This report and accompanying database systematically evaluates the reliability and relevance of the existing scientific literature regarding systemic absorption of nanomaterials by oral exposure and makes specific recommendations for future testing approaches....

  11. Maximal lens bounds on QSO-galaxy association

    International Nuclear Information System (INIS)

    Kovner, I.

    1989-01-01

    The maximal possible enhancement of QSO number counts that can be produced by any ensemble of lenses which conserve brightness and in which the magnification probability is negligibly correlated with the intrinsic QSO flux is obtained. Under the assumption of the Boyle et al. (1988) number-magnitude relation for the QSOs unaffected by lenses, the theory is applied to the QSO-galaxy association sample of Webster et al. (1988). The results suggest that the background QSOs of Webster et al. may be appreciably affected by lensing. 17 refs

  12. Statistical and physical evolution of QSO's

    International Nuclear Information System (INIS)

    Caditz, D.; Petrosian, V.

    1989-09-01

    The relationship between the physical evolution of discrete extragalactic sources, the statistical evolution of the observed population of sources, and the cosmological model is discussed. Three simple forms of statistical evolution: pure luminosity evolution (PLE), pure density evolution (PDE), and generalized luminosity evolution (GLE), are considered in detail together with what these forms imply about the physical evolution of individual sources. Two methods are used to analyze the statistical evolution of the observed distribution of QSO's (quasars) from combined flux limited samples. It is shown that both PLE and PDE are inconsistent with the data over the redshift range 0 less than z less than 2.2, and that a more complicated form of evolution such as GLE is required, independent of the cosmological model. This result is important for physical models of AGN, and in particular, for the accretion disk model which recent results show may be inconsistent with PLE

  13. Performance of Active Wave Absorption Systems

    DEFF Research Database (Denmark)

    Hald, Tue; Frigaard, Peter

    on a horisontal and vertical velocity are treated. All three systems are based on digital FIR-filters. For numerical comparison a performance function combining the frequency response of the set of filters for each system is derived enabling discussion on optimal filter design and system setup. Irregular wave......A comparison of wave gauge based on velocity meter based active absorption systems is presented discussing advantages and disadvantages of the systems. In detail one system based on two surface elevations, one system based on a surface elevation and a horisontal velocity and one system based...... tests with a highly reflective structure with the purely wave gauge based system and the wave gauge velocity meter based system are performed. The wave test depict the differences between the systems....

  14. THE DARK SIDE OF QSO FORMATION AT HIGH REDSHIFTS

    International Nuclear Information System (INIS)

    Romano-Diaz, Emilio; Shlosman, Isaac; Trenti, Michele; Hoffman, Yehuda

    2011-01-01

    Observed high-redshift QSOs, at z ∼ 6, may reside in massive dark matter (DM) halos of more than 10 12 M sun and are thus expected to be surrounded by overdense regions. In a series of 10 constrained simulations, we have tested the environment of such QSOs. The usage of constrained realizations has enabled us to address the issue of cosmic variance and to study the statistical properties of the QSO host halos. Comparing the computed overdensities with respect to the unconstrained simulations of regions empty of QSOs, assuming there is no bias between the DM and baryon distributions, and invoking an observationally constrained duty cycle for Lyman break galaxies, we have obtained the galaxy count number for the QSO environment. We find that a clear discrepancy exists between the computed and observed galaxy counts in the Kim et al. samples. Our simulations predict that on average eight z ∼ 6 galaxies per QSO field should have been observed, while Kim et al. detect on average four galaxies per QSO field compared to an average of three galaxies in a control sample (GOODS fields). While we cannot rule out a small number of statistics for the observed fields to high confidence, the discrepancy suggests that galaxy formation in the QSO neighborhood proceeds differently than in the field. We also find that QSO halos are the most massive of the simulated volume at z ∼ 6 but this is no longer true at z ∼ 3. This implies that QSO halos, even in a case where they are the most massive ones at high redshifts, do not evolve into the most massive galaxy clusters at z = 0.

  15. Endovascular vein harvest: systemic carbon dioxide absorption.

    Science.gov (United States)

    Maslow, Andrew M; Schwartz, Carl S; Bert, Arthur; Hurlburt, Peter; Gough, Jeffrey; Stearns, Gary; Singh, Arun K

    2006-06-01

    Endovascular vein harvest (EDVH) requires CO(2) insufflation to expand the subcutaneous space, allowing visualization and dissection of the saphenous vein. The purpose of this study was to assess the extent of CO(2) absorption during EDVH. Prospective observational study. Single tertiary care hospital. Sixty patients (30 EDVH and 30 open-vein harvest) undergoing isolated coronary artery bypass graft surgery. Hemodynamic, procedural, and laboratory data were collected prior to (baseline), during, and at it the conclusion (final) of vein harvesting. Data were also collected during cardiopulmonary bypass (CPB). Data were compared by using t tests, analysis of variance, and correlation statistics when needed. There were significant increases in arterial CO(2) (PaCO(2), 35%) and decreases in pH (1.35%) during EDVH. These were associated with increases in heart rate, mean blood pressure, and cardiac output. Within the EDVH group, greater elevations (>10 mmHg) in PaCO2 were more likely during difficult harvest procedures, and these patients exhibited greater increase in heart rate. Elevated CO(2) persisted during CPB, requiring higher systemic gas flows and greater use of phenylephrine to maintain desired hemodynamics. EDVH was associated with systemic absorption of CO(2). Greater absorption was more likely in difficult procedures and was associated with greater hemodynamic changes requiring medical therapy.

  16. Analysis of a solar powered absorption system

    International Nuclear Information System (INIS)

    Said, S.A.M.; El-Shaarawi, M.A.I.; Siddiqui, M.U.

    2015-01-01

    Highlights: • Conventional absorption system modified to increase COP. • Results indicated increase of 10% in COP due to dephlegmator heat recovery. • Results indicated increase of 8% in COP due to refrigerant storage unit. • Results indicated increase of 18% in COP due to combined effect of modifications. • Simulation results indicated a very good agreement with the measured results. - Abstract: Today, fossil fuel is the primary extensively used source of energy. However, its negative impact on the environment have forced the energy research continuity to seriously consider renewable sources of energy. Solar energy, in particular, has been the main focus in this regard because it is a source of clean energy and naturally available. This study presents the design and analysis of a solar powered absorption refrigeration system modified to increase its coefficient of performance (COP). The modifications include recovering of waste heat from a dephlegmator and utilization of a refrigerant storage unit. The simulation results indicate an increase of 10% in the COP of the conventional design using dephlegmator heat recovery and an increase of 8% in the COP of the conventional design due to the use of a refrigerant storage. The analysis for the combined effect of modifications indicates an increase of 18% in the COP compared to conventional design. Calculated values of coefficient of performance indicate a very good agreement with the ones obtained based on measurement

  17. Queued Service Observing (QSO) at CFHT II. Queue Preparation and Observation Tools

    Science.gov (United States)

    Vermeulen, T.; Savalle, R.; Martin, P.; Shapiro, J.

    In order to maximize the scientific productivity of the CFH12K mosaic wide-field imager, a Queued Service Observing (QSO) mode of operations was implemented at CFHT . To support this new operational model, a two-tiered system consisting of a Swing-based Java client and a relational database was developed. The various software components were designed to handle selection, scheduling, execution, and validation of programs submitted by the investigators through the CFHT Phase 2 Tool (PH2). This paper will discuss the technical architecture, the reasons behind our choice of technology, and our experience implementing this system during the first two semesters of Queue observing.

  18. QSO Pairs across Active Galaxies: Evidence of Blueshifts? D. Basu

    Indian Academy of Sciences (India)

    2006-12-04

    Dec 4, 2006 ... Abstract. Several QSO pairs have been reported and their redshifts determined, where the two objects in each pair are located across an active galaxy. The usually accepted explanation of such occurrences is that the pair is ejected from the parent galaxy. Currently interpreted redshifted spec- tra for both ...

  19. A Faraday rotation search for magnetic fields in quasar damped Ly alpha absorption systems

    Science.gov (United States)

    Oren, Abraham L.; Wolfe, Arthur M.

    1995-01-01

    We present the results of a Faraday rotation survey of 61 radio-bright QSOs conducted at the National Radio Astronomy Observatory (NRAO) Very Large Array (VLA). The Galactic contribution to the Faraday rotation is estimated and subtracted to determine the extragalactic rotation measure (RRM) for each source. Eleven of these QSOs are known to exhibit damped Ly alpha absorption. The rate of incidence of significant Faraday rotation of these 11 sources is compared to the remaining 50 and is found to be higher at the 99.8% confidence level. However, as this is based upon only two detections of Faraday rotation in the damped Ly alpha sample, the result is only tentative. If the two detections in the damped Ly alpha sample are dug to the absorbing systems, then the inferred rotation measure induced by these systems is roughly 250 rad/sq m. The two detections were for the two lowest redshift absorbers in the sample. We find that a rotation measure of 250 rad/sq m would have gone undetected for any other absorber in the damped Ly alpha sample due to the 1/(1 + 2) squared dilution of the observed RRM with redshift. Thus the data are consistent with, but do not prove, the hypothesis that Faraday rotation is a generic property of damped Ly alpha absorbers. We do not confirm the suggestion that the amplitude of RRMs increases with redshift. Rather, the data are consistent with no redshift evolution. We find that the uncertainty in the estimation of the Galactic rotation measure (GRM) is a more serious problem than previously realized for extra-galactic Faraday rotation studies of QSO absorbers. A careful analysis of current methods for estimating GRM indicate that it can be determined to an accuracy of about 15 - 20 rad/sq m. Previous studies underestimated this uncertainty by more than a factor of 2. Due to this uncertainty, rotation measures such as we suspect are associated with damped Ly alpha absorption systems can only be detected at redshifts less than z approximately

  20. Gintonin absorption in intestinal model systems

    Directory of Open Access Journals (Sweden)

    Byung-Hwan Lee

    2018-01-01

    Conclusion: The present study shows that gintonin could be absorbed in the intestine through transcellular and paracellular diffusion, and active transport. In addition, the lipid component of gintonin might play a key role in its intestinal absorption.

  1. Simulation of absorption refrigeration system for automobile application

    Directory of Open Access Journals (Sweden)

    Ramanathan Anand

    2008-01-01

    Full Text Available An automotive air-conditioning system based on absorption refrigeration cycle has been simulated. This waste heat driven vapor absorption refrigeration system is one alternate to the currently used vapour compression refrigeration system for automotive air-conditioning. Performance analysis of vapor absorption refrigeration system has been done by developing a steady-state simulation model to find the limitation of the proposed system. The water-lithium bromide pair is used as a working mixture for its favorable thermodynamic and transport properties compared to the conventional refrigerants utilized in vapor compression refrigeration applications. The pump power required for the proposed vapor absorption refrigeration system was found lesser than the power required to operate the compressor used in the conventional vapor compression refrigeration system. A possible arrangement of the absorption system for automobile application is proposed.

  2. Cloud Absorption Radiometer Autonomous Navigation System - CANS

    Science.gov (United States)

    Kahle, Duncan; Gatebe, Charles; McCune, Bill; Hellwig, Dustan

    2013-01-01

    CAR (cloud absorption radiometer) acquires spatial reference data from host aircraft navigation systems. This poses various problems during CAR data reduction, including navigation data format, accuracy of position data, accuracy of airframe inertial data, and navigation data rate. Incorporating its own navigation system, which included GPS (Global Positioning System), roll axis inertia and rates, and three axis acceleration, CANS expedites data reduction and increases the accuracy of the CAR end data product. CANS provides a self-contained navigation system for the CAR, using inertial reference and GPS positional information. The intent of the software application was to correct the sensor with respect to aircraft roll in real time based upon inputs from a precision navigation sensor. In addition, the navigation information (including GPS position), attitude data, and sensor position details are all streamed to a remote system for recording and later analysis. CANS comprises a commercially available inertial navigation system with integral GPS capability (Attitude Heading Reference System AHRS) integrated into the CAR support structure and data system. The unit is attached to the bottom of the tripod support structure. The related GPS antenna is located on the P-3 radome immediately above the CAR. The AHRS unit provides a RS-232 data stream containing global position and inertial attitude and velocity data to the CAR, which is recorded concurrently with the CAR data. This independence from aircraft navigation input provides for position and inertial state data that accounts for very small changes in aircraft attitude and position, sensed at the CAR location as opposed to aircraft state sensors typically installed close to the aircraft center of gravity. More accurate positional data enables quicker CAR data reduction with better resolution. The CANS software operates in two modes: initialization/calibration and operational. In the initialization/calibration mode

  3. Structure, shape, and evolution of radiatively accelerated QSO emission-line clouds

    International Nuclear Information System (INIS)

    Blumenthal, G.R.; Mathews, W.G.

    1979-01-01

    The possibility that the broad emission-line regions of QSOs and active galactic nuclei are formed by a multitude of small clouds which are radiatively accelerated is discussed. Although this model is by no means certain at present, it has four virtues: (1) Observed emission-line widths can be produced with observationally allowed electron densities, UV luminosities, and ionization levels. (2) The acceleration force is coherent in each cloud are found. (3) Reasonable line profiles can result for all emission lines. (4) Photoionization of hydrogen accounts for both heating and acceleration of the emission-line gas. A self-consistent model is developed for the structure, shape, and evolution of radiatively accelerated clouds. The shape varies with cloud mass, and two distinct types of clouds. Fully ionized clouds of very low mass approach a nearly spherical shape. However, all clouds having masses greater than some critical mass adopt a ''pancake'' shape. The condition for constant cloud mass in the cloud frame is shown to be equivalent to the equation of motion of a cloud in the rest frame of the QSO. The emission-line profiles can be sensitive to radial variations in the properties of the intercloud medium, and those properties that correspond to observed profiles are discussed. Finally, the covering factor of a system of pancake clouds is estimated along with the total number of clouds required--approximately 10 14 clouds in each QSO

  4. Optimizing the night time with dome vents and SNR-QSO at CFHT

    Science.gov (United States)

    Devost, Daniel; Mahoney, Billy; Moutou, Claire; CFHT QSO Team, CFHT software Group

    2017-06-01

    Night time is a precious and costly commodity and it is important to get everything we can out of every second of every night of observing. In 2012 the Canada-France-Hawaii Telescope started operating 12 new vent doors installed on the dome over the course of the previous two years. The project was highly successful and seeing measurements show that venting the dome greatly enhances image quality at the focal plane. In order to capitalize on the gains brought by the new vents, the observatory started exploring a new mode of observation called SNR-QSO. This mode consist of a new implementation inside our Queued Service Observation (QSO) system. Exposure times are adjusted for each frame depending on the weather conditions in order to reach a specific depth, Signal to Noise Ratio (SNR) at a certain magnitude. The goal of this new mode is to capitalize on the exquisite seeing provided by Maunakea, complemented by the minimized dome turbulence, to use the least amount of time to reach the depth required by the science programs. Specific implementations were successfully tested on two different instruments, our wide field camera MegaCam and our high resolution spectrograph ESPaDOnS. I will present the methods used for each instrument to achieve SNR observing and the gains produced by these new observing modes in order to reach the scientific goals of accepted programs in a shorter amount of time.

  5. Model systems for understanding absorption tuning by opsin proteins

    DEFF Research Database (Denmark)

    Nielsen, Mogens Brøndsted

    2009-01-01

    This tutorial review reports on model systems that have been synthesised and investigated for elucidating how opsin proteins tune the absorption of the protonated retinal Schiff base chromophore. In particular, the importance of the counteranion is highlighted. In addition, the review advocates...... is avoided, and it becomes clear that opsin proteins induce blueshifts in the chromophore absorption rather than redshifts....

  6. The Role of Absorption Cooling for Reaching Sustainable Energy Systems

    Energy Technology Data Exchange (ETDEWEB)

    Lindmark, Susanne

    2005-07-01

    This thesis focuses on the role and potential of absorption cooling in future energy systems. Two types of energy systems are investigated: a district energy system based on waste incineration and a distributed energy system with natural gas as fuel. In both cases, low temperature waste heat is used as driving energy for the absorption cooling. The main focus is to evaluate the absorption technology in an environmental perspective, in terms of reduced CO{sub 2} emissions. Economic evaluations are also performed. The reduced electricity when using absorption cooling instead of compression cooling is quantified and expressed as an increased net electrical yield. The results show that absorption cooling is an environmentally friendly way to produce cooling as it reduces the use of electrically driven cooling in the energy system and therefore also reduces global CO{sub 2} emissions. In the small-scale trigeneration system the electricity use is lowered with 84 % as compared to cooling production with compression chillers only. The CO{sub 2} emissions can be lowered to 45 CO{sub 2}/MWh{sub c} by using recoverable waste heat as driving heat for absorption chillers. However, the most cost effective cooling solution in a district energy system is a combination between absorption and compression cooling technologies according to the study. Absorption chillers have the potential to be suitable bottoming cycles for power production in distributed systems. Net electrical yields over 55 % may be reached in some cases with gas motors and absorption chillers. This small-scale system for cogeneration of power and cooling shows electrical efficiencies comparable to large-scale power plants and may contribute to reducing peak electricity demand associated with the cooling demand.

  7. Pseudoscalar-photon mixing and the large scale alignment of QsO ...

    Indian Academy of Sciences (India)

    physics pp. 679-682. Pseudoscalar-photon mixing and the large scale alignment of QsO optical polarizations. PANKAJ JAIN, sUKANTA PANDA and s sARALA. Physics Department, Indian Institute of Technology, Kanpur 208 016, India. Abstract. We review the observation of large scale alignment of QSO optical polariza-.

  8. Yet another UFO in the X-ray spectrum of a high-z lensed QSO

    Science.gov (United States)

    Dadina, M.; Vignali, C.; Cappi, M.; Lanzuisi, G.; Ponti, G.; Torresi, E.; De Marco, B.; Chartas, G.; Giustini, M.

    2018-02-01

    Aim. Ultra-fast outflows (UFO) appear to be common in local active galactic nuclei (AGN) and may be powerful enough (Ėkin ≥ 1% of Lbol) to effectively quench the star formation in their host galaxies. To test feedback models based on AGN outflows, it is mandatory to investigate UFOs near the peak of AGN activity, that is, at high-z where only a few studies are available to date. Methods: UFOs produce Fe resonant absorption lines measured above ≈7 keV. The most critical problem in detecting such features in distant objects is the difficulty in obtaining X-ray data with sufficient signal-to-noise. We therefore selected a distant QSO that gravitational lensing made bright enough for these purposes, the z = 2.64 QSO MG J0414+0534, and observed it with XMM-Newton for ≈78 ks. Results: The X-ray spectrum of MG J0414+0534 is complex and shows signatures of cold absorption (NH ≈ 4 × 1022 cm-2) and of the presence of an iron emission line (E ≈ 6.4 keV, EW = 95 ± 53 eV) consistent with it originating in the cold absorber. Our main result, however, is the robust detection (more than 5σ) of an absorption line at Eint ≈ 9.2 keV (Eobs ≈ 2.5 keV observer frame). If interpreted as due to FeXXVI, it implies gas outflowing at vout ≈ 0.3c. To our knowledge, this is the first detection of an UFO in a radio-loud quasar at z ≥ 1.5. We estimated that the UFO mechanical output is Ėkin ≈ 2.5Lbol with ṗout/ṗrad ≈ 17 indicating that it is capable of installing significant feedback between the super-massive black hole and the bulge of the host galaxy. We argue that this also suggests a magnetic driving origin of the UFO.

  9. Artificial neural network analysis of triple effect absorption refrigeration systems

    Energy Technology Data Exchange (ETDEWEB)

    Hajizadeh Aghdam, A. [Department of Mechanical Engineering, Islamic Azad University (Iran, Islamic Republic of)], email: a.hajizadeh@iaukashan.ac.ir; Nazmara, H.; Farzaneh, B. [Department of Mechanical Engineering, University of Tabriz (Iran, Islamic Republic of)], email: h.nazmara@nioec.org, email: b_farzaneh_ms@yahoo.com

    2011-07-01

    In this study, artificial neural networks are utilized to predict the performance of triple effect series and parallel flow absorption refrigeration systems, with lithium bromide/water as the working fluid. Important parameters such as high generator and evaporator temperatures were varied and their effects on the performance characteristics of the refrigeration unit were observed. Absorption refrigeration systems make energy savings possible because they can use heat energy to produce cooling, in place of the electricity used for conventional vapour compression chillers. In addition, non-conventional sources of energy (such as solar, waste heat, and geothermal) can be utilized as their primary energy input. Moreover, absorption units use environmentally friendly working fluid pairs instead of CFCs and HCFCs, which affect the ozone layer. Triple effect absorption cycles were analysed. Results apply for both series and parallel flow systems. A relative preference for parallel-flow over series-flow is also shown.

  10. The distribution of absorptive power dissipation in irradiated nanoparticulate system

    International Nuclear Information System (INIS)

    Li, Jiayu; Yang, Jian; Gu, Xiaobing

    2016-01-01

    The knowledge of local radiant absorption is important to the nanostructure optimization, it is beneficial to the applications in energy harvesting, optical heating, photocatalysis, etc. In this paper, FDTD model is constructed for the distribution of absorptive power dissipation in irradiated nanoparticulate system. The theoretical model extended from Mie theory is used to examine the FDTD model, the parameters and conditions set for FDTD simulation are confirmed based on the comparison. Then, the influence of Ag nanoparticle on the absorptive properties of nearby TiO_2 nanoparticle is investigated by FDTD simulation at the wavelength of 0.25 μm. It is indicated that suitable distance between TiO_2 and Ag particles is beneficial to the spectral radiant absorption of TiO_2 particle. Considering the agglomeration of nanoparticles and the oxidation at the TiO_2–Ag interface, the Ag core coated with Al_2O_3 shell is suggested, and the simulated results indicated that the shell thickness and the Ag core size need to be optimized for enhancing the radiant absorption of TiO_2 particle. - Highlights: • The absorptive power distribution in nanoparticulate system is simulated by FDTD. • FDTD simulation is compared with theoretical model extended from Mie theory. • The parameters and conditions are confirmed based on the comparison. • The influence of Ag nanoparticle on nearby TiO_2 particle's absorption is analyzed.

  11. The Physical Constraints on a New LoBAL QSO at z = 4.82

    Energy Technology Data Exchange (ETDEWEB)

    Yi, Weimin; Bai, Jin-Ming [Yunnan Observatories, Chinese Academy of Sciences, Kunming 650216 (China); Green, Richard; Fan, Xiaohui; Milne, Peter [Steward Observatory, University of Arizona, Tucson, AZ 85721-0065 (United States); Wang, Tinggui; Yang, Chenwei [CAS Key Laboratory for Research in Galaxies and Cosmology, Department of Astronomy, University of Science and Technology of China (China); Grier, Catherine J.; Trump, Jonathan R.; Brandt, William N. [Department of Astronomy and Astrophysics and Institute for Gravitation and the Cosmos, The Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802 (United States); Zuo, Wenwen [Shanghai Astronomical Observatory, Chinese Academy of Sciences, Shanghai 200030 (China); Yang, Jinyi; Wang, Feige; Wu, Xue-Bing; Jiang, Linhua; Yang, Qian [Department of Astronomy, School of Physics, Peking University, Beijing 100871 (China); Zhou, Hongyan [Polar Research Institute of China, 451 Jinqiao Road, Shanghai 200136 (China); Varricatt, Watson; Kerr, Tom; Benigni, Sam [UKIRT Observatory, Hilo, HI 96720 (United States); and others

    2017-04-01

    Very few low-ionization broad absorption line (LoBAL) QSOs have been found at high redshifts, to date. One high-redshift LoBAL QSO, J0122+1216, was recently discovered by the Lijiang 2.4 m Telescope, with an initial redshift determination of 4.76. Aiming to investigate its physical properties, we carried out follow-up observations in the optical and near-IR spectroscopy. Near-IR spectra from UKIRT and P200 confirm that it is a LoBAL, with a new redshift determination of 4.82 ± 0.01 based on the Mg ii emission-line. The new Mg ii redshift determination reveals strong blueshifts and asymmetry of the high-ionization emission lines. We estimate a black hole mass of ∼2.3 × 10{sup 9} M {sub ⊙} and Eddington ratio of ∼1.0 according to the empirical Mg ii-based single-epoch relation and bolometric correction factor. It is possible that strong outflows are the result of an extreme quasar environment driven by the high Eddington ratio. A lower limit on the outflowing kinetic power (>0.9% L {sub Edd}) is derived from both emission and absorption lines, indicating that these outflows play a significant role in the feedback process that regulates the growth of its black hole, as well as host galaxy evolution.

  12. Spectrophotometer-Integrating-Sphere System for Computing Solar Absorptance

    Science.gov (United States)

    Witte, William G., Jr.; Slemp, Wayne S.; Perry, John E., Jr.

    1991-01-01

    A commercially available ultraviolet, visible, near-infrared spectrophotometer was modified to utilize an 8-inch-diameter modified Edwards-type integrated sphere. Software was written so that the reflectance spectra could be used to obtain solar absorptance values of 1-inch-diameter specimens. A descriptions of the system, spectral reflectance, and software for calculation of solar absorptance from reflectance data are presented.

  13. Second law analysis of double effect vapour absorption cooler system

    International Nuclear Information System (INIS)

    Gomri, Rabah; Hakimi, Riad

    2008-01-01

    In this paper, exergy analysis of double effect lithium bromide/water absorption refrigeration system is presented. The system consists of a second effect generator between the generator and condenser of the single effect absorption refrigeration system, including two solution heat exchangers between the absorber and the two generators. In order to simulate the refrigeration system by using a computer, a new set of computationally efficient formulations of thermodynamic properties of lithium bromide/water solution developed is used. The exergy analysis is carried out for each component of the system. All exergy losses that exist in double effect lithium bromide/water absorption system are calculated. In addition to the coefficient of performance and the exergetic efficiency of the system, the number of exergy of each component of the system is also estimated. This study suggests the component of the absorption refrigeration system that should be developed. The results show that the performance of the system increases with increasing low pressure generator (LPG) temperature, but decreases with increasing high pressure generator (HPG) temperature. The highest exergy loss occurs in the absorber and in the HPG, which therefore makes the absorber and HPG the most important components of the double effect refrigeration system

  14. Optomechanically induced absorption in parity-time-symmetric optomechanical systems

    Science.gov (United States)

    Zhang, X. Y.; Guo, Y. Q.; Pei, P.; Yi, X. X.

    2017-06-01

    We explore the optomechanically induced absorption (OMIA) in a parity-time- (PT -) symmetric optomechanical system (OMS). By numerically calculating the Lyapunov exponents, we find out the stability border of the PT -symmetric OMS. The results show that in the PT -symmetric phase the system can be either stable or unstable depending on the coupling constant and the decay rate. In the PT -symmetric broken phase the system can have a stable state only for small gain rates. By calculating the transmission rate of the probe field, we find that there is an inverted optomechanically induced transparency (OMIT) at δ =-ωM and an OMIA at δ =ωM for the PT -symmetric optomechanical system. At each side of δ =-ωM there is an absorption window due to the resonance absorption of the two generated supermodes. Comparing with the case of optomechanics coupled to a passive cavity, we find that the active cavity can enhance the resonance absorption. The absorption rate at δ =ωM increases as the coupling strength between the two cavities increases. Our work provides us with a promising platform for controlling light propagation and light manipulation in terms of PT symmetry, which might have potential applications in quantum information processing and quantum optical devices.

  15. Multiple wavelength multitimescale optical absorption system

    International Nuclear Information System (INIS)

    Lubis, R.; Allan, D.; Hodgson, B.W.; Swallow, A.J.

    1992-01-01

    A new workstation for pulse radiolysis studies has been developed for the Paterson Institute Linear Accelerator Laboratory. It is particularly suited to the study of materials available only in limited quantities. The analysing light beam is dispersed into a plane spectrum by a McPherson 270 monochromator and focused down to a line spectrum by a rod lens. The spectral intensity distribution is sampled by a linear array of optical fibres which conduct the light to photodiodes. A preamplifier unit amplifies and buffers the diode photocurrent signal which then passes to the main electronics unit incorporating further amplification stages, filters, backing-off of the background photocurrent, analog-to-digital conversion, data storage memory and a computer interface. All control of the electronic system is performed from a computer equipped with appropriate software. The system has 10 channels of spectral bandwidth 16 nm, a useful spectral response from 350 nm to 1 μm with a high signal-to-noise ratio, signal sampling rates from 20 MHz to 2 kHz and 8 kbyte of local memory for each channel. (author)

  16. Multiple wavelength multitimescale optical absorption system

    Science.gov (United States)

    Lubis, R.; Allan, D.; Hodgson, B. W.; Swallow, A. J.

    A new workstation for pulse radiolysis studies has been developed for the Paterson Institute Linear Accelerator Laboratory. It is particularly suited to the study of materials available only in limited quantities. The analysing light beam is dispersed into a plane spectrum by a McPherson 270 monochromator and focused down to a line spectrum by a rod lens. The spectral intensity distribution is sampled by a linear array of optical fibres which conduct the light to photodiodes. A preamplifier unit amplifies and buffers the diode photocurrent signal which then passes to the main electronics unit incorporating further amplification stages, filters, backing-off of the background photocurrent, analog-to-digital conversion, data storage memory and a computer interface. All control of the electronic system is performed from a computer equipped with appropriate software. The system has 10 channels of spectral bandwidth 16 nm, a useful spectral response from 350 nm to 1 μm with a high signal-to-noise ratio, signal sampling rates from 20 MHz to 2 kHz and 8 kbyte of local memory for each channel.

  17. Computational Model of a Biomass Driven Absorption Refrigeration System

    Directory of Open Access Journals (Sweden)

    Munyeowaji Mbikan

    2017-02-01

    Full Text Available The impact of vapour compression refrigeration is the main push for scientists to find an alternative sustainable technology. Vapour absorption is an ideal technology which makes use of waste heat or renewable heat, such as biomass, to drive absorption chillers from medium to large applications. In this paper, the aim was to investigate the feasibility of a biomass driven aqua-ammonia absorption system. An estimation of the solid biomass fuel quantity required to provide heat for the operation of a vapour absorption refrigeration cycle (VARC is presented; the quantity of biomass required depends on the fuel density and the efficiency of the combustion and heat transfer systems. A single-stage aqua-ammonia refrigeration system analysis routine was developed to evaluate the system performance and ascertain the rate of energy transfer required to operate the system, and hence, the biomass quantity needed. In conclusion, this study demonstrated the results of the performance of a computational model of an aqua-ammonia system under a range of parameters. The model showed good agreement with published experimental data.

  18. Newly discovered IRAS QSO close to the Galactic plane

    International Nuclear Information System (INIS)

    Strauss, M.A.; Kirhakos, S.D.; Yahil, A.

    1988-01-01

    CCD observations of the IRAS QSO candidate I09149-6206 performed at CTIO during December 1987 are reported, including 564-806-nm spectroscopy obtained with the 1.5-m telescope and direct UVBRI imaging obtained with the 0.91-m telescope. The data are presented in tables and graphs and characterized in detail. It is found that the source is surrounded by a faint fuzz with low surface brightness and strong forbidden O III lines. Parameters determined include redshift z = 0.0571, Galactic latitude -9.2 deg, V magnitude 13.55, Galactic reddening E(B-V) = about 0.23, and absolute V magnitude about -24.87. 33 references

  19. Thermodynamic simulation of ammonia-water absorption refrigeration system

    Directory of Open Access Journals (Sweden)

    Sathyabhama A.

    2008-01-01

    Full Text Available The ammonia-water absorption refrigeration system is attracting increasing research interests, since the system can be powered by waste thermal energy, thus reducing demand on electricity supply. The development of this technology demands reliable and effective system simulations. In this work, a thermodynamic simulation of the cycle is carried out to investigate the effects of different operating variables on the performance of the cycle. A computer program in C language is written for the performance analysis of the cycle.

  20. The X-ray spectrum of QSO 0241+622. [OSO-8 observations

    Science.gov (United States)

    Worrall, D. M.; Boldt, E. A.; Holt, S. S.; Serlemitsos, P. J.

    1980-01-01

    Proportional counters on the OsO-8 spacecraft measured the X-ray spectrum of QSR 0241+622 in the range 2-50 keV. The best power law fit has a proton spectral index and 90 percent errors gamma = 1.93 (+0.5, -0.3) and low energy absorption consistent with reported gas column densities, but a thermal bremsstrahlung form with temperature 13.1 keV cannot be excluded. No indication of spectral variability is found in three observations of the source with HEAO-A2, although a possible 15-30 percent intensity change over a period of 6 months was observed. The quasar is similar to 3C 273 in the proportion of energy emitted in various bands, excluding the radio, if reported radiation above 50 keV from its direction is indeed associated with QSO 0241+622. The two quasars are compared and possible energy generation scenarios are discussed. Implications concerning quasar contributions to the diffuse background are discussed.

  1. Simulation of solar-powered absorption cooling system

    Energy Technology Data Exchange (ETDEWEB)

    Atmaca, I.; Yigit, A. [Uludag Univ., Bursa (Turkey). Dept. of Mechanical Engineering

    2003-07-01

    With developing technology and the rapid increase in world population, the demand for energy is ever increasing. Conventional energy will not be enough to meet the continuously increasing need for energy in the future. In this case, renewable energy sources will become important. Solar energy is a very important energy source because of its advantages. Instead of a compressor system, which uses electricity, an absorption cooling system, using renewable energy and kinds of waste heat energy, may be used for cooling. In this study, a solar-powered, single stage, absorption cooling system, using a water-lithium bromide solution, is simulated. A modular computer program has been developed for the absorption system to simulate various cycle configurations and solar energy parameters for Antalya, Turkey. So, the effects of hot water inlet temperatures on the coefficient of performance (COP) and the surface area of the absorption cooling components are studied. In addition, reference temperatures which are the minimum allowable hot water inlet temperatures are determined and their effect on the fraction of the total load met by non-purchased energy (FNP) and the coefficient of performance are researched. Also, the effects of the collector type and storage tank mass are investigated in detail. (author)

  2. Backscatter absorption gas imaging systems and light sources therefore

    Science.gov (United States)

    Kulp, Thomas Jan [Livermore, CA; Kliner, Dahv A. V. [San Ramon, CA; Sommers, Ricky [Oakley, CA; Goers, Uta-Barbara [Campbell, NY; Armstrong, Karla M [Livermore, CA

    2006-12-19

    The location of gases that are not visible to the unaided human eye can be determined using tuned light sources that spectroscopically probe the gases and cameras that can provide images corresponding to the absorption of the gases. The present invention is a light source for a backscatter absorption gas imaging (BAGI) system, and a light source incorporating the light source, that can be used to remotely detect and produce images of "invisible" gases. The inventive light source has a light producing element, an optical amplifier, and an optical parametric oscillator to generate wavelength tunable light in the IR. By using a multi-mode light source and an amplifier that operates using 915 nm pump sources, the power consumption of the light source is reduced to a level that can be operated by batteries for long periods of time. In addition, the light source is tunable over the absorption bands of many hydrocarbons, making it useful for detecting hazardous gases.

  3. Lack of dust in quasar absorption line systems

    International Nuclear Information System (INIS)

    Jura, M.

    1977-01-01

    It is stated that the origin of absorption line systems in quasars is still uncertain. Most such systems apparently have atomic hydrogen column densities of the order of 10 19 /cm 2 , but at least two quasars, 1331 + 170 and PHL957, have such strong Lyman α absorption lines that atomic hydrogen column densities of the order of 10 21 /cm 2 are indicated. It should be possible to observe the dust produced 2,200 A extinction feature as it is red shifted into the visible, and to determine whether absorption line systems are produced in spiral galaxies where the dust content is similar to that in the interstellar medium. It has been argued that the emission line regions of quasars generally lack dust and that towards PHL957 the 2,200 A feature is absent. The present author argues that dust similar to that found in the interstellar medium is not found towards the quasars 1331 + 170 and PHL957. This could explain why H 2 is not found towards PHL957, and it indicates that the absorption line systems in quasars are not produced in spiral galaxies similar to our own. It seems from the analysis presented that the dust-to-gas ratio towards 1331 + 170 is at least a factor of 20 less than in the interstellar medium, and there is no reason to suppose that this lack of dust results from a lack of metals It is concluded that there seems to be a lack of normal dust towards PHL957 by at least a factor of two; and that the absorption region towards 1331 + 170 and probably the region towards PHL957 are lacking dust similar to that in our own galaxy. This can explain the lack of H 2 in these systems. (U.K.)

  4. Confining hot spots in 3C 196 - implications for QSO-companion galaxies

    International Nuclear Information System (INIS)

    Brown, R.L.; Broderick, J.J.; Mitchell, K.J.; Virginia Polytechnic Institute and State Univ., Blacksburg; NASA, Goddard Space Flight Center, Greenbelt, MD)

    1986-01-01

    VLBI observations of the extremely compact hot spot in the northern radio lobe of the QSO 3C 196 reveal the angular size of its smallest substructure to be 0.065 arcsec x 0.045 arcsec or about 300 pc at the redshift distance. The morphology of the hot spot and its orientation relative to the more diffuse radio emission suggest that it is formed by an oblique interaction between the nuclear QSO jet and circum-QSO cloud. The inferred density in this cloud, together with its apparent size, imply that the cloud contains a galactic mass, greater than a billion solar masses of gas. The effect of the jet will be to hasten gravitational collapse of the cloud. If many QSOs such as 3C 196 are formed or found in gas-rich environments, the QSO radio phase may commonly stimulate the metamorphosis of circum-QSO gas to QSO-companion galaxies or it may play a significant part in catalyzing star formation in existing companions. 30 references

  5. ALMACAL - III. A combined ALMA and MUSE survey for neutral, molecular, and ionized gas in an H I-absorption-selected system

    Science.gov (United States)

    Klitsch, A.; Péroux, C.; Zwaan, M. A.; Smail, I.; Oteo, I.; Biggs, A. D.; Popping, G.; Swinbank, A. M.

    2018-03-01

    Studying the flow of baryons into and out of galaxies is an important part of understanding the evolution of galaxies over time. We present a detailed case study of the environment around an intervening Ly α absorption line system at zabs = 0.633, seen towards the quasar J0423-0130 (zQSO = 0.915). We detect with ALMA the 12CO(2-1), 12CO(3-2), and 1.2 mm continuum emission from a galaxy at the redshift of the Ly α absorber at a projected distance of 135 kpc. From the ALMA detections, we infer interstellar medium conditions similar to those in low-redshift luminous infrared galaxies. Director's Discretionary Time (DDT) Multi-Unit Spectroscopic Explorer (MUSE) integral field unit observations reveal the optical counterpart of the 12CO emission line source and three additional emission line galaxies at the absorber redshift, which together form a galaxy group. The 12CO emission line detections originate from the most massive galaxy in this group. While we cannot exclude that we miss a fainter host, we reach a dust-uncorrected star formation rate (SFR) limit of >0.3 M⊙yr-1 within 100 kpc from the sightline to the background quasar. We measure the dust-corrected SFR (ranging from 3 to 50 M⊙ yr-1), the morpho-kinematics and the metallicities of the four group galaxies to understand the relation between the group and the neutral gas probed in absorption. We find that the Ly α absorber traces either an outflow from the most massive galaxy or intragroup gas. This case study illustrates the power of combining ALMA and MUSE to obtain a census of the cool baryons in a bounded structure at intermediate redshift.

  6. Performance of a compact solar absorption cooling system

    International Nuclear Information System (INIS)

    Mulyanef; Kamaruzzaman Sopian

    2006-01-01

    This paper describes the performance of a compact solar absorption system. Purpose of compact solar is collector, generator and condenser in one unit. At present, two types of absorption cooling systems are marketed: the lithium bromide-water system and the ammonia-water system. In the lithium bromide-water system, water vapor is the refrigerant and ammonia water system where ammonia is the refrigerant. In addition, the ammonia-water system requires higher generator temperature 120 o C to 150 o C than a flat-plate solar collector can provide without special techniques. The lithium bromide-water system operates satisfactorily at a generator temperature of 75 o C to 100 o C, achievable by a flat-plate collector. The lithium bromide-water system also has a higher COP than the ammonia-water system. The disadvantage of the lithium bromide-water systems is that the evaporators cannot operate at temperature below 0 o C since the refrigerant is water. The Coefficient of Performance (COP) system is 0.62 and the concentration of LiBr-H 2 O is 50%

  7. Economic performance optimization of an absorption cooling system under uncertainty

    International Nuclear Information System (INIS)

    Gebreslassie, Berhane H.; Guillen-Gosalbez, Gonzalo; Jimenez, Laureano; Boer, Dieter

    2009-01-01

    Many of the strategies devised so far to address the optimization of energy systems are deterministic approaches that rely on estimated data. However, in real world applications there are many sources of uncertainty that introduce variability into the decision-making problem. Within this general context, we propose a novel approach to address the design of absorption cooling systems under uncertainty in the energy cost. As opposed to other approaches that optimize the expected performance of the system as a single objective, in our method the design task is formulated as a stochastic bi-criteria non-linear optimization problem that simultaneously accounts for the minimization of the expected total cost and the financial risk associated with the investment. The latter criterion is measured by the downside risk, which avoids the need to define binary variables thus improving the computational performance of the model. The capabilities of the proposed modeling framework and solution strategy are illustrated in a case study problem that addresses the design of a typical absorption cooling system. Numerical results demonstrate that the method presented allows to manage the risk level effectively by varying the area of the heat exchangers of the absorption cycle. Specifically, our strategy allows identifying the optimal values of the operating and design variables of the cycle that make it less sensitive to fluctuations in the energy price, thus improving its robustness in the face of uncertainty.

  8. Absorption in multiple scattering systems of coated spheres: design applications

    International Nuclear Information System (INIS)

    Stout, Brian; Andraud, Christine; Stout, Sophie; Lafait, Jacques

    2003-01-01

    We illustrate the utility of some recently derived transfer matrix methods for electromagnetic scattering calculations in systems composed of coated spherical scatterers. Any of the spherical coatings, cores, or host media may be composed of absorbing materials. Our formulae permit the calculation of local absorption in either orientation fixed or orientation averaged situations. We introduce methods for estimating the macroscopic transport properties of such media, and show how our scattering calculations can permit 'design' optimization of macroscopic properties

  9. β Absorption dust concentration monitor system based on the PLC

    International Nuclear Information System (INIS)

    Lian Dexing; Zhou Xiuliang; Liu Liyan; Li Zonglun; Cao Guanghui; Mao Wanchong

    2011-01-01

    To provide an on-line automatic system for dust concentration monitor is the purpose of this design.The system based on β-ray-absorption-method,employing PLC (Programmable Logic Controller) control technology, is presented. The user input parameter setup,the data acquisition and processing, and the communication with computer can be effectively regulated using the advanced PLC control technology. It has the features of high reliability, easy operation and easy maintenance, and the ability to monitor remotely. Measurement range: 0.1-1500 mg/m 3 , Accuracy: ±9%. The structure,working principle, electric circuit and software development of the system are introduced in detail. (authors)

  10. Spectroscopy of 125 QSO candidates and radio galaxies

    International Nuclear Information System (INIS)

    Wills, B.J.; Wills, D.

    1980-01-01

    Spectroscopic observations of 125 QSO candidates and radio galaxies are reported, many of which are optical identifications of radio sources in the deep survey in progress at the University of Texas Radio Astronomy Observatory (UTRAO). The remainder include optical identifications of sources in other radio surveys and radio-quiet objects selected by their ultraviolet continua or optical variability. Optical positions are given with O''.5 accuracy for 56 of the objects.Forty objects are confirmed as QSOs; redshifts are given for 38 of them and for 18 galaxies. There are also seven objects with apparently continuous spectra: some of them were already known or suspected to be BL Lacertae objects. Twenty-nine objects were found to be Galactic stars, and the results for the remaining 31 are inconclusive, although 12 of them are probable QSOs and six are probable stars.Our spectroscopy of a sample of 90 blue stellar objects found within 3'' of the UTRAO radio positions (including results from two earlier papers) shows that 81 (90%) are QSOs, with inconclusive results fo the other nine; none of the 90 is known to be a star. Even within 5'' of the UTRAO positions, 111 of 128 blue objects (87%) are QSOs, and only five (4%) are known or suspected to be stars. Among 21 red or neutral-color, apparently stellar objects within 3'' of the UTRAO positions, six are QSOs or compact galaxies, 13 are stars, and the results for two more are inconclusive

  11. Monitoring and analysis of an absorption air-conditioning system

    Energy Technology Data Exchange (ETDEWEB)

    Perez de Vinaspre, M.; Bourouis, M.; Coronas, A. [Centro de Innovacion Tecnologica en Revalorizacion Energetica y Refrigeracion, Tarragona (Spain); Garcia, A.; Soto, V.; Pinazo, J.M. [E.T.S. Ingenieros Industriales, Valencia (Spain)

    2004-09-01

    In the last few years, high-energy consumption due to air-conditioning has led to a growing interest in the efficient use of energy in buildings. Although simulation programs have always been the main tools for analyzing energy in buildings, the reliability of their results is often compromised by a lack of certainty to reflect real conditions. The aim of this work is to monitorize and analyze the thermal behavior of an absorption-based air-conditioning installation of a university building in Tarragona, Spain. The existing monitoring system of the installation has been improved by implementing additional sensors and flow meters. The data has been stored during summer 2002 and used to assess the energy balance of the air-conditioning installation and the operational regime of the absorption chiller. [Author].

  12. Energy and exergy analyses of the diffusion absorption refrigeration system

    International Nuclear Information System (INIS)

    Yıldız, Abdullah; Ersöz, Mustafa Ali

    2013-01-01

    This paper describes the thermodynamic analyses of a DAR (diffusion absorption refrigeration) cycle. The experimental apparatus is set up to an ammonia–water DAR cycle with helium as the auxiliary inert gas. A thermodynamic model including mass, energy and exergy balance equations are presented for each component of the DAR cycle and this model is then validated by comparison with experimental data. In the thermodynamic analyses, energy and exergy losses for each component of the system are quantified and illustrated. The systems' energy and exergy losses and efficiencies are investigated. The highest energy and exergy losses occur in the solution heat exchanger. The highest energy losses in the experimental and theoretical analyses are found 25.7090 W and 25.4788 W respectively, whereas those losses as to exergy are calculated 13.7933 W and 13.9976 W. Although the values of energy efficiencies obtained from both the model and experimental studies are calculated as 0.1858, those values, in terms of exergy efficiencies are found 0.0260 and 0.0356. - Highlights: • The diffusion absorption refrigerator system is designed manufactured and tested. • The energy and exergy analyses of the system are presented theoretically and experimentally. • The energy and exergy losses are investigated for each component of the system. • The highest energy and exergy losses occur in the solution heat exchanger. • The energy and the exergy performances are also calculated

  13. Airborne differential absorption lidar system for water vapor investigations

    Science.gov (United States)

    Browell, E. V.; Carter, A. F.; Wilkerson, T. D.

    1981-01-01

    Range-resolved water vapor measurements using the differential-absorption lidar (DIAL) technique is described in detail. The system uses two independently tunable optically pumped lasers operating in the near infrared with laser pulses of less than 100 microseconds separation, to minimize concentration errors caused by atmospheric scattering. Water vapor concentration profiles are calculated for each measurement by a minicomputer, in real time. The work is needed in the study of atmospheric motion and thermodynamics as well as in forestry and agriculture problems.

  14. Industrial trigeneration using ammonia-water absorption refrigeration systems (AAR)

    International Nuclear Information System (INIS)

    Colonna, Piero; Gabrielli, Sandro

    2003-01-01

    In many industrial processes there is a simultaneous need for electric power and refrigeration at low temperatures. Examples are in the food and chemical industries. Nowadays the increase in fuel prices and the ecological implications are giving an impulse to energy technologies that better exploit the primary energy source and integrated production of utilities should be considered when designing a new production plant. The number of so-called trigeneration systems installations (electric generator and absorption refrigeration plant) is increasing. If low temperature refrigeration is needed (from 0 to -40 deg. C), ammonia-water absorption refrigeration plants can be coupled to internal combustion engines or turbogenerators. A thermodynamic system study of trigeneration configurations using a commercial software integrated with specifically designed modules is presented. The study analyzes and compares heat recovery from the primary mover at different temperature levels. In the last section a simplified economic assessment that takes into account disparate prices in European countries compares conventional electric energy supply from the grid and optimized trigeneration plants in one test case (10 MW electric power, 7000 h/year)

  15. New thermodynamical systems. Alternative of compression-absorption; Nouveaux systemes thermodynamiques. Alternative de la compression-absorption

    Energy Technology Data Exchange (ETDEWEB)

    Feidt, M.; Brunin, O.; Lottin, O.; Vidal, J.F. [Universite Henri Poincare Nancy, 54 - Vandoeuvre-les-Nancy (France); Hivet, B. [Electricite de France, 77 - Moret sur Loing (France)

    1996-12-31

    This paper describes a 5 years joint research work carried out by Electricite de France (EdF) and the ESPE group of the LEMTA on compression-absorption heat pumps. It shows how a thermodynamical model of machinery, completed with precise exchanger-reactor models, allows to simulate and dimension (and eventually optimize) the system. A small power prototype has been tested and the first results are analyzed with the help of the models. A real scale experiment in industrial sites is expected in the future. (J.S.) 20 refs.

  16. Absorption solar cooling systems using optimal driving temperatures

    International Nuclear Information System (INIS)

    Lecuona, Antonio; Ventas, Rubén; Vereda, Ciro; López, Ricardo

    2015-01-01

    The optimum instantaneous driving temperature of a solar cooling facility is determined along a day. The chillers compared use single effect cycles working with NH 3 /LiNO 3 , either conventional or hybridised by incorporating a low pressure booster compressor. Their performances are compared with a H 2 O/LiBr single effect absorption chiller as part of the same solar system. The results of a detailed thermodynamic cycle for the absorption chillers allow synthesizing them in a modified characteristic temperature difference model. The day accumulated solar cold production is determined using this optimum temperature during two sunny days in mid-July and mid-September, located in Madrid, Spain. The work shows the influences of operational variables and a striking result: selection of a time-constant temperature during all the day does not necessarily imply a substantial loss, being the temperature chosen a key parameter. The results indicate that the NH 3 /LiNO 3 option with no boosting offers a smaller production above-zero Celsius degrees temperatures, but does not require higher hot water driving temperatures than H 2 O/LiBr. The boosted cycle offers superior performance. Some operational details are discussed. - Highlights: • Instantaneous optimum driving temperature t g,op for solar cooling in Madrid. • 3 absorption cycles tested: H 2 O/LiBr and NH 3 /LiNO 3 single effect and hybrid. • The t g,op of the hybrid cycle is 16 °C lower than both single effect cycles. • The best fixed driving temperature can reach almost the same behaviour than t g,op

  17. Close Separation Triple System QSO 1009-0252 with Discordant ...

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... Since January 2016, the Journal of Astrophysics and Astronomy has moved to Continuous Article Publishing (CAP) mode. This means that each accepted article is being published immediately online with DOI and article citation ID with starting page number 1. Articles are also visible in Web of Science ...

  18. A low-cost vaporization-atomization system for atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Bruhn F, C.G.; Ambiado V, F.; Woerner V, R.

    1990-01-01

    A low-cost vaporization-atomization system for atomic absorption spectrometry is developed as an alternative to the use of a graphite furnace in electrothermal atomic absorption spectrometry. (Author)

  19. The redshift number density evolution of Mg II absorption systems

    International Nuclear Information System (INIS)

    Chen Zhi-Fu

    2013-01-01

    We make use of the recent large sample of 17 042 Mg II absorption systems from Quider et al. to analyze the evolution of the redshift number density. Regardless of the strength of the absorption line, we find that the evolution of the redshift number density can be clearly distinguished into three different phases. In the intermediate redshift epoch (0.6 ≲ z ≲ 1.6), the evolution of the redshift number density is consistent with the non-evolution curve, however, the non-evolution curve over-predicts the values of the redshift number density in the early (z ≲ 0.6) and late (z ≳ 1.6) epochs. Based on the invariant cross-section of the absorber, the lack of evolution in the redshift number density compared to the non-evolution curve implies the galaxy number density does not evolve during the middle epoch. The flat evolution of the redshift number density tends to correspond to a shallow evolution in the galaxy merger rate during the late epoch, and the steep decrease of the redshift number density might be ascribed to the small mass of halos during the early epoch.

  20. Optical performance and metallic absorption in nanoplasmonic systems.

    Science.gov (United States)

    Arnold, Matthew D; Blaber, Martin G

    2009-03-02

    Optical metrics relating to metallic absorption in representative plasmonic systems are surveyed, with a view to developing heuristics for optimizing performance over a range of applications. We use the real part of the permittivity as the independent variable; consider strengths of particle resonances, resolving power of planar lenses, and guiding lengths of planar waveguides; and compare nearly-free-electron metals including Al, Cu, Ag, Au, Li, Na, and K. Whilst the imaginary part of metal permittivity has a strong damping effect, field distribution is equally important and thus factors including geometry, real permittivity and frequency must be considered when selecting a metal. Al performs well at low permittivities (e.g. sphere resonances, superlenses) whereas Au & Ag only perform well at very negative permittivities (shell and rod resonances, LRSPP). The alkali metals perform well overall but present engineering challenges.

  1. Understanding Absorptive Capacities is an "Innovation Systems" Context

    DEFF Research Database (Denmark)

    Narula, Rajneesh

    2004-01-01

    This paper seeks to broaden our understanding of the concept underlying absorptive capacity atthe macro -level, paying particular attention to the growth and development perspectives. Weprovide definitions of absorptive and technological capacity, external technology flows,productivity growth....... We also undertake to explain how the nature ofabsorptive capacity changes with stages of economic development, and the importance of thedifferent aspects of absorptive capability at different stages. The relationship is not a linear one:the benefits that accrue from marginal increases in absorptive...... capability change over time.Finally, we provide a tentative and preliminary conceptual argument of how the different stagesof absorptive capacity are related to productivity growth, economic growth and employmentcreation.Key words: New economy, absorptive capacity, knowledge...

  2. PROVIDING STRINGENT STAR FORMATION RATE LIMITS OF z ∼ 2 QSO HOST GALAXIES AT HIGH ANGULAR RESOLUTION

    Energy Technology Data Exchange (ETDEWEB)

    Vayner, Andrey; Wright, Shelley A. [Department of Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON, M5S 3H4 (Canada); Do, Tuan [Dunlap Institute for Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON, M5S 3H4 (Canada); Larkin, James E. [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 (United States); Armus, Lee [Spitzer Science Center, California Institute of Technology, 1200 E. California Boulevard, Pasadena, CA 91125 (United States); Gallagher, S. C. [Department of Physics and Astronomy, The University of Western Ontario, London, ON N6A 3K7 (Canada)

    2016-04-10

    We present integral field spectrograph (IFS) with laser guide star adaptive optics (LGS-AO) observations of z ∼ 2 quasi-stellar objects (QSOs) designed to resolve extended nebular line emission from the host galaxy. Our data was obtained with W. M. Keck and Gemini North Observatories, using OSIRIS and NIFS coupled with the LGS-AO systems, respectively. We have conducted a pilot survey of five QSOs, three observed with NIFS+AO and two observed with OSIRIS+AO at an average redshift of z = 2.2. We demonstrate that the combination of AO and IFSs provides the necessary spatial and spectral resolutions required to separate QSO emission from its host. We present our technique for generating a point-spread function (PSF) from the broad-line region of the QSO and performing PSF subtraction of the QSO emission to detect the host galaxy emission at a separation of ∼0.″2 (∼1.4 kpc). We detect Hα narrow-line emission for two sources, SDSS J1029+6510 (z{sub Hα} = 2.182) and SDSS J0925+0655 (z{sub Hα} = 2.197), that have evidence for both star formation and extended narrow-line emission. Assuming that the majority of narrow-line Hα emission is from star formation, we infer a star formation rate (SFR) for SDSS J1029+6510 of 78.4 M{sub ⊙} yr{sup −1} originating from a compact region that is kinematically offset by 290–350 km s{sup −1}. For SDSS J0925+0655 we infer a SFR of 29 M{sub ⊙} yr{sup −1} distributed over three clumps that are spatially offset by ∼7 kpc. The null detections on three of the QSOs are used to infer surface brightness limits and we find that at 1.4 kpc from the QSO the un-reddened star formation limit is ≲0.3 M{sub ⊙} yr{sup −1} kpc{sup −2}. If we assume typical extinction values for z = 2 type-1 QSOs, the dereddened SFR for our null detections would be ≲0.6 M{sub ⊙} yr{sup −1} kpc{sup −2}. These IFS observations indicate that while the central black hole is accreting mass at 10%–40% of the Eddington rate, if

  3. Rapidly reconfigurable slow-light system based on off-resonant Raman absorption

    International Nuclear Information System (INIS)

    Vudyasetu, Praveen K.; Howell, John C.; Camacho, Ryan M.

    2010-01-01

    We present a slow-light system based on dual Raman absorption resonances in warm rubidium vapor. Each Raman absorption resonance is produced by a control beam in an off-resonant Λ system. This system combines all optical control of the Raman absorption and the low-dispersion broadening properties of the double Lorentzian absorption slow light. The bandwidth, group delay, and central frequency of the slow-light system can all be tuned dynamically by changing the properties of the control beam. We demonstrate multiple pulse delays with low distortion and show that such a system has fast switching dynamics and thus fast reconfiguration rates.

  4. Water absorption length measurement with the ANTARES optical beacon system

    International Nuclear Information System (INIS)

    Yepes-Ramirez, Harold

    2011-01-01

    ANTARES is a neutrino telescope located in the Mediterranean Sea with the aim of detecting high energy neutrinos of extra-terrestrial origin. It consists of a three dimensional array on 12 detection lines of photomultiplier tubes (PMTs) able to detect the Cherenkov light induced by muons produced in the interaction of neutrinos with the surrounding water and seabed. To reach the best angular resolution, good time and positioning calibrations are required. The propagation of Cherenkov photons strongly depends on the optical properties of the sea water, which has an impact on the reconstruction efficiency. The determination of the optical parameters, as the absorption and scattering lengths, is crucial to calculate properly the effective area and the angular resolution of the detector. The ANTARES optical beacon system consists of pulsed and fast, well controlled light sources distributed throughout the detector to carry out in situ the relative time calibration of the detector components. In this contribution we show some results on the sea water optical properties and their stability measured with the optical beacon system.

  5. Sulfur K-edge absorption spectroscopy on selected biological systems

    International Nuclear Information System (INIS)

    Lichtenberg, Henning

    2008-07-01

    Sulfur is an essential element in organisms. In this thesis investigations of sulfur compounds in selected biological systems by XANES (X-ray Absorption Near Edge Structure) spectroscopy are reported. XANES spectroscopy at the sulfur K-edge provides an excellent tool to gain information about the local environments of sulfur atoms in intact biological samples - no extraction processes are required. Spatially resolved measurements using a Kirkpatrick-Baez mirror focusing system were carried out to investigate the infection of wheat leaves by rust fungi. The results give information about changes in the sulfur metabolism of the host induced by the parasite and about the extension of the infection into visibly uninfected plant tissue. Furthermore, XANES spectra of microbial mats from sulfidic caves were measured. These mats are dominated by microbial groups involved in cycling sulfur. Additionally, the influence of sulfate deprivation and H 2 S exposure on sulfur compounds in onion was investigated. To gain an insight into the thermal degradation of organic material the influence of roasting of sulfur compounds in coffee beans was studied. (orig.)

  6. X-ray heating and ionization of broad-emission-line regions in QSO's and active galaxies

    International Nuclear Information System (INIS)

    Weisheit, J.C.; Shields, G.A.; Tarter, C.B.

    1980-07-01

    Absorption of x-rays deep within the broad-line emitting clouds in QSO's and the nuclei of active galaxies creates extensive zones of warm (T approx. 10 4 K), partially ionized N/sub e//N approx. 0.1) gas. Because Lyman alpha photons are trapped in these regions, the x-ray energy is efficiently channeled into Balmer lines collisionally excited from the n = 2 level. The HI regions plus the HII regions created by ultraviolet photons illuminating the surfaces of the clouds give rise to integrated Lα/Hα line emission ratios between 1 and 2. Enhanced MgII line emission from the HI regions gives rise to integrated MgII/Hα ratios near 0.5. The OI line lambda 8446 is efficiently pumped by trapped Hα photons and in the x-ray heated zone an intensity ratio I (lambda 8446)/I(Hα) approx. < 0.1 is calculated. All of these computed ratios now are in agreement with observations

  7. A LARGE NUMBER OF z > 6 GALAXIES AROUND A QSO AT z = 6.43: EVIDENCE FOR A PROTOCLUSTER?

    International Nuclear Information System (INIS)

    Utsumi, Yousuke; Kashikawa, Nobunari; Miyazaki, Satoshi; Komiyama, Yutaka; Goto, Tomotsugu; Furusawa, Hisanori; Overzier, Roderik

    2010-01-01

    QSOs have been thought to be important for tracing highly biased regions in the early universe, from which the present-day massive galaxies and galaxy clusters formed. While overdensities of star-forming galaxies have been found around QSOs at 2 6 is less clear. Previous studies with the Hubble Space Telescope (HST) have reported the detection of small excesses of faint dropout galaxies in some QSO fields, but these surveys probed a relatively small region surrounding the QSOs. To overcome this problem, we have observed the most distant QSO at z = 6.4 using the large field of view of the Suprime-Cam (34' x 27'). Newly installed red-sensitive fully depleted CCDs allowed us to select Lyman break galaxies (LBGs) at z ∼ 6.4 more efficiently. We found seven LBGs in the QSO field, whereas only one exists in a comparison field. The significance of this apparent excess is difficult to quantify without spectroscopic confirmation and additional control fields. The Poisson probability to find seven objects when one expects four is ∼10%, while the probability to find seven objects in one field and only one in the other is less than 0.4%, suggesting that the QSO field is significantly overdense relative to the control field. These conclusions are supported by a comparison with a cosmological smoothed particle hydrodynamics simulation which includes the higher order clustering of galaxies. We find some evidence that the LBGs are distributed in a ring-like shape centered on the QSO with a radius of ∼3 Mpc. There are no candidate LBGs within 2 Mpc from the QSO, i.e., galaxies are clustered around the QSO but appear to avoid the very center. These results suggest that the QSO is embedded in an overdense region when defined on a sufficiently large scale (i.e., larger than an HST/ACS pointing). This suggests that the QSO was indeed born in a massive halo. The central deficit of galaxies may indicate that (1) the strong UV radiation from the QSO suppressed galaxy formation in

  8. A new active absorption system and its performance to linear and non-linear waves

    DEFF Research Database (Denmark)

    Andersen, Thomas Lykke; Clavero, M.; Frigaard, Peter Bak

    2016-01-01

    Highlights •An active absorption system for wavemakers has been developed. •The theory for flush mounted gauges has been extended to cover also small gaps. •The new system has been validated in a wave flume with wavemakers in both ends. •A generation and absorption procedure for highly non-linear...

  9. Photoacoustic Experimental System to Confirm Infrared Absorption Due to Greenhouse Gases

    Science.gov (United States)

    Kaneko, Fumitoshi; Monjushiro, Hideaki; Nishiyama, Masayoshi; Kasai, Toshio; Harris, Harold H.

    2010-01-01

    An experimental system for detecting infrared absorption using the photoacoustic (PA) effect is described. It is aimed for use at high-school level to illustrate the difference in infrared (IR) absorption among the gases contained in the atmosphere in connection with the greenhouse effect. The experimental system can be built with readily…

  10. CONCEPT OF AUTOMATIC CONTROL SYSTEM FOR IMPROVING THE EFFICIENCY OF THE ABSORPTION REFRIGERATING UNITS

    Directory of Open Access Journals (Sweden)

    O. Titlova

    2016-12-01

    Full Text Available The general concept of the automatic control systems constructing for increasing the efficiency of the artificial cold production process in the absorption refrigerating units is substantiated. The described automatic control systems provides necessary degree of the ammonia vapor purification from the water in all absorption refrigerating units modes and minimizes heat loss from the dephlegmator surface.

  11. Spectroscopy of QSO candidates from the Jodrell Bank 966 MHz survey

    International Nuclear Information System (INIS)

    Walsh, D.; Wills, B.J.; Wills, D.

    1979-01-01

    Forty-two QSO candidates from the Jodrell Bank 966 MHz survey have been observed spectroscopically at McDonald Observatory. Twenty-five are confirmed as QSOs, and redshifts are given for 19 of them. Two objects are compact galaxies, and another probably is; redshifts are given for these. Seven objects are stars. Of the remaining seven objects, six are probably QSOs and one is probably a star. (author)

  12. 0114 + 074 - A very asymmetric galaxy in the field of an intermediate-redshift QSO

    International Nuclear Information System (INIS)

    Akujor, C.E.

    1989-01-01

    New radio-continuum observations of 0114 + 074 (4C 07.4) are presented. It is shown that this radio source consists of two distinct objects: a point source identified with an 18.0 mag QSO and a highly asymmetric 18.5 mag galaxy. The patently asymmetric structure of the galaxy is most plausibly due to intrinsically asymmetric energy funding of the lobes by the central machine or nucleus, rather than external influences. 41 refs

  13. The effect of age on systemic absorption and systemic disposition of bupivacaine after subarachnoid administration

    Energy Technology Data Exchange (ETDEWEB)

    Veering, B.T.; Burm, A.G.; Vletter, A.A.; van den Hoeven, R.A.; Spierdijk, J. (Leiden Univ. Hospital (Netherlands))

    1991-02-01

    In order to evaluate the role of the pharmacokinetics of the age-related changes in the clinical profile of spinal anesthesia with bupivacaine, we studied the influence of age on the systemic absorption and systemic disposition of bupivacaine after subarachnoid administration in 20 male patients (22-81 yr), ASA Physical Status 1 or 2, by a stable isotope method. After subarachnoid administration of 3 ml 0.5% bupivacaine in 8% glucose, a deuterium-labeled analog (13.4 mg) was administered intravenously. Blood samples were collected for 24 h. Plasma concentrations of unlabeled and deuterium-labeled bupivacaine were determined with a combination of gas chromatography and mass fragmentography. Biexponential functions were fitted to the plasma concentration-time data of the deuterium-labeled bupivacaine. The systemic absorption was evaluated by means of deconvolution. Mono- and biexponential functions were fitted to the data of fraction absorbed versus time. The maximal height of analgesia and the duration of analgesia at T12 increased with age (r = 0.715, P less than 0.001; r = 0.640, P less than 0.01, respectively). In 18 patients the systemic absorption of bupivacaine was best described by a biexponential equation. The half-life of the slow systemic absorption process (r = -0.478; P less than 0.05) and the mean absorption time (r = -0.551; P less than 0.02) decreased with age. The total plasma clearance decreased with age (r = -0.650, P less than 0.002), whereas the mean residence time and terminal half-life increased with age (r = 0.597, P less than 0.01; r = 0.503, P less than 0.05).

  14. The effect of age on systemic absorption and systemic disposition of bupivacaine after subarachnoid administration

    International Nuclear Information System (INIS)

    Veering, B.T.; Burm, A.G.; Vletter, A.A.; van den Hoeven, R.A.; Spierdijk, J.

    1991-01-01

    In order to evaluate the role of the pharmacokinetics of the age-related changes in the clinical profile of spinal anesthesia with bupivacaine, we studied the influence of age on the systemic absorption and systemic disposition of bupivacaine after subarachnoid administration in 20 male patients (22-81 yr), ASA Physical Status 1 or 2, by a stable isotope method. After subarachnoid administration of 3 ml 0.5% bupivacaine in 8% glucose, a deuterium-labeled analog (13.4 mg) was administered intravenously. Blood samples were collected for 24 h. Plasma concentrations of unlabeled and deuterium-labeled bupivacaine were determined with a combination of gas chromatography and mass fragmentography. Biexponential functions were fitted to the plasma concentration-time data of the deuterium-labeled bupivacaine. The systemic absorption was evaluated by means of deconvolution. Mono- and biexponential functions were fitted to the data of fraction absorbed versus time. The maximal height of analgesia and the duration of analgesia at T12 increased with age (r = 0.715, P less than 0.001; r = 0.640, P less than 0.01, respectively). In 18 patients the systemic absorption of bupivacaine was best described by a biexponential equation. The half-life of the slow systemic absorption process (r = -0.478; P less than 0.05) and the mean absorption time (r = -0.551; P less than 0.02) decreased with age. The total plasma clearance decreased with age (r = -0.650, P less than 0.002), whereas the mean residence time and terminal half-life increased with age (r = 0.597, P less than 0.01; r = 0.503, P less than 0.05)

  15. Thermionic detection of the ionic fragments of continiuum-state pair absorption systems

    International Nuclear Information System (INIS)

    Hotop, R.; Niemax, K.; Richter, J.; Weber, K.H.

    1981-01-01

    Using a thermionic diode we have detected the ionic fragments formed by associative ionization and dissociation after continuum-state pair absorption processes in Cs-Cs and Cs-K systems. Assuming an ionization probability of unity of the excited species and calibrating the pair absorption bands by taking into account the known photoionization cross section of the atoms we found excellent agreement with data from classical absorption measurements. (orig.)

  16. Residential solar air conditioning: Energy and exergy analyses of an ammonia–water absorption cooling system

    International Nuclear Information System (INIS)

    Aman, J.; Ting, D.S.-K.; Henshaw, P.

    2014-01-01

    Large scale heat-driven absorption cooling systems are available in the marketplace for industrial applications but the concept of a solar driven absorption chiller for air-conditioning applications is relatively new. Absorption chillers have a lower efficiency than compression refrigeration systems, when used for small scale applications and this restrains the absorption cooling system from air conditioning applications in residential buildings. The potential of a solar driven ammonia–water absorption chiller for residential air conditioning application is discussed and analyzed in this paper. A thermodynamic model has been developed based on a 10 kW air cooled ammonia–water absorption chiller driven by solar thermal energy. Both energy and exergy analyses have been conducted to evaluate the performance of this residential scale cooling system. The analyses uncovered that the absorber is where the most exergy loss occurs (63%) followed by the generator (13%) and the condenser (11%). Furthermore, the exergy loss of the condenser and absorber greatly increase with temperature, the generator less so, and the exergy loss in the evaporator is the least sensitive to increasing temperature. -- Highlights: • 10 kW solar thermal driven ammonia–water air cooled absorption chiller is investigated. • Energy and exergy analyses have been done to enhance the thermal performance. • Low driving temperature heat sources have been optimized. • The efficiencies of the major components have been evaluated

  17. A experimental system for the checking of the absorption of E.C.A.G. graphite

    International Nuclear Information System (INIS)

    Raievski, V.; Vidal, R.

    1958-01-01

    A system is described for measuring the mean absorption cross section in thermal neutrons of graphite. This system consists of a graphite stack containing a Ra-Be source and a BF3 counter. A cavity in the stack receives the graphite to be studied or the graphite standard. By comparing the counting rates their absorption ratio can be deduced. The measurement is performed on graphite rods which have been machined before being placed in the pile. It provides the possibility of detecting over a batch of 1 ton of graphite, in a single measurement, a difference in absorption of 0.1 milli barn. (author) [fr

  18. In vitro and in vivo percutaneous absorption of retinol from cosmetic formulations: Significance of the skin reservoir and prediction of systemic absorption

    International Nuclear Information System (INIS)

    Yourick, Jeffrey J.; Jung, Connie T.; Bronaugh, Robert L.

    2008-01-01

    The percutaneous absorption of retinol (Vitamin A) from cosmetic formulations was studied to predict systemic absorption and to understand the significance of the skin reservoir in in vitro absorption studies. Viable skin from fuzzy rat or human subjects was assembled in flow-through diffusion cells for in vitro absorption studies. In vivo absorption studies using fuzzy rats were performed in glass metabolism cages for collection of urine, feces, and body content. Retinol (0.3%) formulations (hydroalcoholic gel and oil-in-water emulsion) containing 3 H-retinol were applied and absorption was measured at 24 or 72 h. All percentages reported are % of applied dose. In vitro studies using human skin and the gel and emulsion vehicles found 0.3 and 1.3% retinol, respectively, in receptor fluid at 24 h. Levels of absorption in the receptor fluid increased over 72 h with the gel and emulsion vehicles. Using the gel vehicle, in vitro rat skin studies found 23% in skin and 6% in receptor fluid at 24 h, while 72-h studies found 18% in skin and 13% in receptor fluid. Thus, significant amounts of retinol remained in rat skin at 24 h and decreased over 72 h, with proportional increases in receptor fluid. In vivo rat studies with the gel found 4% systemic absorption of retinol after 24 h and systemic absorption did not increase at 72 h. Retinol remaining in rat skin after in vivo application was 18% and 13% of the applied dermal dose after 24 and 72 h, respectively. Similar observations were made with the oil-in water emulsion vehicle in the rat. Retinol formed a reservoir in rat skin both in vivo and in vitro. Little additional retinol was bioavailable after 24 h. Comparison of these in vitro and in vivo results for absorption through rat skin indicates that the 24-h in vitro receptor fluid value accurately estimated 24-h in vivo systemic absorption. Therefore, the best single estimate of retinol systemic absorption from in vitro human skin studies is the 24-h receptor fluid

  19. High-Redshift QSOs in the SWIRE Survey and the z~3 QSO Luminosity Function

    Science.gov (United States)

    Siana, Brian; Polletta, Maria del Carmen; Smith, Harding E.; Lonsdale, Carol J.; Gonzalez-Solares, Eduardo; Farrah, Duncan; Babbedge, Tom S. R.; Rowan-Robinson, Michael; Surace, Jason; Shupe, David; Fang, Fan; Franceschini, Alberto; Oliver, Seb

    2008-03-01

    We use a simple optical/infrared (IR) photometric selection of high-redshift QSOs that identifies a Lyman break in the optical photometry and requires a red IR color to distinguish QSOs from common interlopers. The search yields 100 z ~ 3 (U-dropout) QSO candidates with 19 dropout) sample suffers from both unreliability and incompleteness but present seven previously unidentified QSOs at 3.50 University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation.

  20. Automotive exhaust gas flow control for an ammonia–water absorption refrigeration system

    International Nuclear Information System (INIS)

    Rêgo, A.T.; Hanriot, S.M.; Oliveira, A.F.; Brito, P.; Rêgo, T.F.U.

    2014-01-01

    A considerable part of the energy generated by an automotive internal combustion engine is wasted as heat in the exhaust system. This wasted heat could be recovered and applied to power auxiliary systems in a vehicle, contributing to its overall energy efficiency. In the present work, the experimental analysis of an absorption refrigeration system was performed. The exhaust system of an automotive internal combustion engine was connected to the generator element of an absorption refrigeration system. The performance of the absorption refrigerator was evaluated as a function of the supplied heat. The use of a control strategy for the engine exhaust gas mass flow rate was implemented to optimize the system. Exhaust gas flow was controlled by step-motor actuated valves commanded by a microcontroller in which a proportional-integral control scheme was implemented. Information such as engine torque, speed, key temperatures in the absorption cycle, as well as internal temperatures of the refrigerator was measured in a transient regime. The results indicated that the refrigeration system exhibited better performance when the amount of input heat is controlled based on the temperature of the absorption cycle generator. It was possible to conclude that, by dynamically controlling the amount of input heat, the utilisation range of the absorption refrigeration system powered by exhaust gas heat could be expanded in order to incorporate high engine speed operating conditions. - Highlights: •An absorption refrigerator was driven by automotive exhaust gas heat. •A system for controlling the refrigeration system heat input was developed. •Excessive exhaust gas heat leads to ineffective operation of the refrigerator. •Control of refrigerator's generator temperature led to better performance. •The use of exhaust gas was possible for high engine speeds

  1. Emergency membrane contactor based absorption system for ammonia leaks in water treatment plants.

    Science.gov (United States)

    Shao, Jiahui; Fang, Xuliang; He, Yiliang; Jin, Qiang

    2008-01-01

    Abstract Because of the suspected health risks of trihalomethanes (THMs), more and more water treatment plants have replaced traditional chlorine disinfection process with chloramines but often without the proper absorption system installed in the case of ammonia leaks in the storage room. A pilot plant membrane absorption system was developed and installed in a water treatment plant for this purpose. Experimentally determined contact angle, surface tension, and corrosion tests indicated that the sulfuric acid was the proper choice as the absorbent for leaking ammonia using polypropylene hollow fiber membrane contactor. Effects of several operating conditions on the mass transfer coefficient, ammonia absorption, and removal efficiency were examined, including the liquid concentration, liquid velocity, and feed gas concentration. Under the operation conditions investigated, the gas absorption efficiency over 99.9% was achieved. This indicated that the designed pilot plant membrane absorption system was effective to absorb the leaking ammonia in the model storage room. The removal rate of the ammonia in the model storage room was also experimentally and theoretically found to be primarily determined by the ammonia suction flow rate from the ammonia storage room to the membrane contactor. The ammonia removal rate of 99.9% was expected to be achieved within 1.3 h at the ammonia gas flow rate of 500 m3/h. The success of the pilot plant membrane absorption system developed in this study illustrated the potential of this technology for ammonia leaks in water treatment plant, also paved the way towards a larger scale application.

  2. Remote Laser Evaporative Molecular Absorption Spectroscopy Sensor System

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose a sensor system capable of remotely probing the molecular composition of cold solar system targets (asteroids, comets, planets, moons), such as from a...

  3. LiBr absorption systems integrated with high–efficiency IGSG plant

    DEFF Research Database (Denmark)

    Rokni, Masoud; Bellomare, Filippo

    2015-01-01

    vapor compression inverse cycles; waste heat from other systems can in fact be used as an efficient input instead of electrical energy. The opportunity to integrate Li-Br absorption systems with a high-efficiency energy plant was studied; rejected heat from a Municipal Solid Waste Gasification Plant......Over the last few years, the energy demand for cooling systems is increasing; different solutions in fact have been proposed in order to minimize the energetic and environmental impact of this trend. In this direction, absorption cooling systems are recognized as a valid alternative to traditional...

  4. Increasing efficacy and reducing systemic absorption of brimonidine tartrate ophthalmic gels in rabbits.

    Science.gov (United States)

    Pang, Xiaochen; Li, Jiawei; Pi, Jiaxin; Qi, Dongli; Guo, Pan; Li, Nan; Wu, Yumei; Liu, Zhidong

    2018-03-01

    Systemic absorption of ocularly administered Brimonidine Tartrate has been reported to give rise to several side-effects. Hence, it has become crucial to develop a delivery system that could increase efficacy and reduce systemic absorption. Therefore, the present work aims to develop Brimonidine Tartrate gels with different concentrations (0.05%, 0.1%, and 0.2% w/v, respectively) using Carbopol 974 P and HPMC E4M, and compare the therapeutic efficacy and systemic absorption with that of eye drop (0.2%, w/v) by UPLC-MS/MS. The result of histological analysis did not show any morphological or structural changes after the administration of formulations. In vitro residence time studies demonstrated that the gels exhibited a better precorneal residence time as compared with the eye drop. The gels with lower concentrations of the drug (0.05% and 0.1%, w/v) could significantly decrease intraocular pressure (IOP) in both normal and water-loaded rabbits as compared to the eye drop. Finally, the values of the ratio of AUC (0→∞) in comparison to eye drop showed the gels with lower concentrations of Brimonidine Tartrate could decrease the systemic absorption. From the result, it can be concluded the 0.1% ophthalmic gel has a potential to improve therapeutic efficacy and reduce the potential toxicity caused by systemic absorption.

  5. Parametric analysis of an irreversible proton exchange membrane fuel cell/absorption refrigerator hybrid system

    International Nuclear Information System (INIS)

    Yang, Puqing; Zhang, Houcheng

    2015-01-01

    A hybrid system mainly consisting of a PEMFC (proton exchange membrane fuel cell) and an absorption refrigerator is proposed, where the PEMFC directly converts the chemical energy contained in the hydrogen into electrical and thermal energies, and the thermal energy is transferred to drive the bottoming absorption refrigerator for cooling purpose. By considering the existing irreversible losses in the hybrid system, the operating current density region of the PEMFC permits the absorption refrigerator to exert its function is determined and the analytical expressions for the equivalent power output and efficiency of the hybrid system under different operating conditions are specified. Numerical calculations show that the equivalent maximum power density and the corresponding efficiency of the hybrid system can be respectively increased by 5.3% and 6.8% compared to that of the stand-alone PEMFC. Comprehensive parametric analyses are conducted to reveal the effects of the internal irreversibility of the absorption refrigerator, operating current density, operating temperature and operating pressure of the PEMFC, and some integrated parameters related to the thermodynamic losses on the performance of the hybrid system. The model presented in the paper is more general than previous study, and the results for some special cases can be directly derived from this paper. - Highlights: • A CHP system composed of a PEMFC and an absorption refrigerator is proposed. • Current density region enables the absorption refrigerator to work is determined. • Multiple irreversible losses in the system are analytically characterized. • Maximum power density and corresponding efficiency can be increased by 5.3% and 6.8%. • Effects of some designing and operating parameters on the performance are discussed

  6. Moisture movement in cement-based repair systems monitored by X-ray absorption

    NARCIS (Netherlands)

    Lukovic, M.; Ye, G.; Schlangen, H.E.J.G.; van Breugel, K.

    2017-01-01

    In concrete repair systems, material properties in the repair material and interface are greatly influenced by the initial moisture content of the concrete (or mortar) substrate. In order to quantify moisture profiles inside the repair system, X-ray absorption was used. Preliminary studies are

  7. Safety, tolerability, and systemic absorption of dapivirine vaginal microbicide gel in healthy, HIV-negative women

    NARCIS (Netherlands)

    Nel, Annalene M.; Coplan, Paul; van de Wijgert, Janneke H.; Kapiga, Saidi H.; von Mollendorf, Claire; Geubbels, Eveline; Vyankandondera, Joseph; Rees, Helen V.; Masenga, Gileard; Kiwelu, Ireen; Moyes, Jocelyn; Smythe, Shanique C.

    2009-01-01

    To assess the local and systemic safety of dapivirine vaginal gel vs. placebo gel as well as the systemic absorption of dapivirine in healthy, HIV-negative women. Two prospective, randomized, double-blind, placebo-controlled phase I/II studies were conducted at five research centers, four in Africa

  8. Absorption of electromagnetic field energy by superfluid system of atoms with electric dipole moment

    International Nuclear Information System (INIS)

    Poluektov, Yu.M.

    2014-01-01

    The modified Gross-Pitaevskii equation which takes into account relaxation and interaction with alternating electromagnetic field is used to consider the absorption of electromagnetic field energy by a superfluid system on the assumption that the atoms has intrinsic dipole moment. It is shown that the absorption may be of a resonant behavior only if the dispersion curves of the electromagnetic wave and the excitations of the superfluid system intersect. It is remarkable that such a situation is possible if the superfluid system has a branch of excitations with the energy gap at low momenta. The experiments on absorption of microwaves in superfluid helium are interpreted as evidence of existence of such gap excitations. A possible modification of the excitation spectrum of superfluid helium in the presence of excitation branch with energy gap is dis-cussed qualitatively

  9. Photosynthetic antennae systems: energy transport and optical absorption

    International Nuclear Information System (INIS)

    Reineker, P.; Supritz, Ch.; Warns, Ch.; Barvik, I.

    2004-01-01

    The energy transport and the optical line shape of molecular aggregates, modeling bacteria photosynthetic light-harvesting systems (chlorosomes in the case of Chlorobium tepidum or Chloroflexus aurantiacus and LH2 in the case of Rhodopseudomonas acidophila) is investigated theoretically. The molecular units are described by two-level systems with an average excitation energy ε and interacting with each other through nearest-neighbor interactions. For LH2 an elliptical deformation of the ring is also allowed. Furthermore, dynamic and in the case of LH2 also quasi-static fluctuations of the local excitation energies are taken into account, simulating fast molecular vibrations and slow motions of the protein backbone, respectively. The fluctuations are described by Gaussian Markov processes in the case of the chlorosomes and by colored dichotomic Markov processes, with exponentially decaying correlation functions, with small (λ s ) and large (λ) decay constants, in the case of LH2

  10. Absorptive capacity, technological innovation, and product life cycle: a system dynamics model.

    Science.gov (United States)

    Zou, Bo; Guo, Feng; Guo, Jinyu

    2016-01-01

    While past research has recognized the importance of the dynamic nature of absorptive capacity, there is limited knowledge on how to generate a fair and comprehensive analytical framework. Based on interviews with 24 Chinese firms, this study develops a system-dynamics model that incorporates an important feedback loop among absorptive capacity, technological innovation, and product life cycle (PLC). The simulation results reveal that (1) PLC affects the dynamic process of absorptive capacity; (2) the absorptive capacity of a firm peaks in the growth stage of PLC, and (3) the market demand at different PLC stages is the main driving force in firms' technological innovations. This study also explores a sensitivity simulation using the variables of (1) time spent in founding an external knowledge network, (2) research and development period, and (3) knowledge diversity. The sensitivity simulation results show that the changes of these three variables have a greater impact on absorptive capacity and technological innovation during growth and maturity stages than in the introduction and declining stages of PLC. We provide suggestions on how firms can adjust management policies to improve their absorptive capacity and technological innovation performance during different PLC stages.

  11. Experimental results of a direct air-cooled ammonia–lithium nitrate absorption refrigeration system

    International Nuclear Information System (INIS)

    Llamas-Guillén, S.U.; Cuevas, R.; Best, R.; Gómez, V.H.

    2014-01-01

    Absorption thermal cooling systems driven by renewable energy are a viable option in order to reduce fossil fuel consumption and the associated emissions. This work shows the results of an air cooled absorption cooling prototype working with an ammonia–lithium nitrate mixture at high ambient temperatures. An absorption refrigeration system was designed and built. The prototype is a one stage ammonia–lithium nitrate air cooled chiller. The experimental system was instrumented to evaluate each component. This paper shows the operation conditions in the experimental unit as well as some of the heat loads encountered at different operating conditions. The system was operated successfully at ambient temperatures in the range of 25–35 °C. A series of test showed that even at ambient temperatures it can be operated at evaporator temperatures below 10 °C producing chilled water for air conditioning applications such as radiative cooling panels. The system proved to stabilize very quickly and no risk of crystallization was encountered so the first results are promising in order to continue with the development of a more advanced prototype. - Highlights: •Experimental results of a direct air-cooled ammonia–lithium nitrate system. •The prototype is a one stage ammonia–lithium nitrate air cooled chiller. •The absorption system was operated successfully at ambient temperatures. •Cooling loads of 4.5 kW were reached in the chilled water side

  12. Prototype explosives detection system based on nuclear resonance absorption in nitrogen

    International Nuclear Information System (INIS)

    Morgado, R.E.; Arnone, G.J.; Cappiello, C.C.

    1996-01-01

    A laboratory prototype system has been developed for the experimental evaluation of an explosives detection technique based on nuclear resonance absorption of gamma rays in nitrogen. Major subsystems include a radiofrequency quadrupole proton accelerator and associated beam transport system, a high-power gamma-ray production target, an airline-luggage tomographic inspection system, and an image- processing/detection-alarm subsystem. The detection system performance, based on a limited experimental test, is reported

  13. Performance modelling and simulation of an absorption solar cooling system for Malaysia

    International Nuclear Information System (INIS)

    Assilzadeh, F.; Ali, Y.; Kamaruzzaman Sopian

    2006-01-01

    Solar radiation contains huge amounts of energy and is required for almost all the natural processes on earth. Solar-powered air-conditioning has many advantages when compared to normal electricity system. This paper presents a solar cooling system that has been designed for Malaysia and other tropical regions using evacuated tube solar collector and LiBr absorption system. A modelling and simulation of absorption solar cooling system is modeled in Transient System Simulation (TRNSYS) environment. The typical meteorological year file containing the weather parameters is used to simulate the system. Then a system optimization is carried out in order to select the appropriate type of collector, the optimum size of storage tank, the optimum collector slope and area and the optimum thermostat setting of the auxiliary boiler

  14. Preliminary aseismic analysis on bolts of driving mechanism in absorption sphere shutdown system

    International Nuclear Information System (INIS)

    Chen Feng; Li Tianjin; Zhang Zhengming; Huang Zhiyong; Bo Hanliang

    2012-01-01

    The absorption sphere shutdown system performs an important role in reactivity regulating and control. Driving mechanism is a set of key mechanical moving parts which is used to control falling of absorption spheres in absorption sphere shutdown system. It is about 5 m for driving mechanism with the slim structure, which is connected with the upper supported plate of metal reactor internals through storage vessel with bolts. Both the storage vessel and driving mechanism are equipment of seismic classification I. It is significant to calculate and check the bolts strength of driving mechanism. In this paper, complicate structure of driving mechanism was simplified to three variable cross sections and statically indeterminate problem was solved. The bolts at the bottom and on the top of the storage vessel were calculated and checked. The preliminary results indicate that the bolts strength is reliable and safe, and the supporting force at the most weak point of driving mechanism is as well obtained. (authors)

  15. LiCl Dehumidifier LiBr absorption chiller hybrid air conditioning system with energy recovery

    Science.gov (United States)

    Ko, Suk M.

    1980-01-01

    This invention relates to a hybrid air conditioning system that combines a solar powered LiCl dehumidifier with a LiBr absorption chiller. The desiccant dehumidifier removes the latent load by absorbing moisture from the air, and the sensible load is removed by the absorption chiller. The desiccant dehumidifier is coupled to a regenerator and the desiccant in the regenerator is heated by solar heated hot water to drive the moisture therefrom before being fed back to the dehumidifier. The heat of vaporization expended in the desiccant regenerator is recovered and used to partially preheat the driving fluid of the absorption chiller, thus substantially improving the overall COP of the hybrid system.

  16. Airborne differential absorption lidar system for measurements of atmospheric water vapor and aerosols

    Science.gov (United States)

    Carter, Arlen F.; Allen, Robert J.; Mayo, M. Neale; Butler, Carolyn F.; Grossman, Benoist E.; Ismail, Syed; Grant, William B.; Browell, Edward V.; Higdon, Noah S.; Mayor, Shane D.; hide

    1994-01-01

    An airborne differential absorption lidar (DIAL) system has been developed at the NASA Langley Research Center for remote measurements of atmospheric water vapor (H2O) and aerosols. A solid-state alexandrite laser with a 1-pm linewidth and greater than 99.85% spectral purity was used as the on-line transmitter. Solid-state avalanche photodiode detector technology has replaced photomultiplier tubes in the receiver system, providing an average increase by a factor of 1.5-2.5 in the signal-to-noise ratio of the H2O measurement. By incorporating advanced diagnostic and data-acquisition instrumentation into other subsystems, we achieved additional improvements in system operational reliability and measurement accuracy. Laboratory spectroscopic measurements of H2O absorption-line parameters were performed to reduce the uncertainties in our knowledge of the absorption cross sections. Line-center H2O absorption cross sections were determined, with errors of 3-6%, for more than 120 lines in the 720-nm region. Flight tests of the system were conducted during 1989-1991 on the NASA Wallops Flight Facility Electra aircraft, and extensive intercomparison measurements were performed with dew-point hygrometers and H2O radiosondes. The H2O distributions measured with the DIAL system differed by less than 10% from the profiles determined with the in situ probes in a variety of atmospheric conditions.

  17. Damped Lyman-alpha absorption by disk galaxies with large redshifts. III. Intermediate-resolution spectroscopy

    International Nuclear Information System (INIS)

    Turnshek, D.A.; Wolfe, A.M.; Lanzetta, K.M.; Briggs, F.H.; Cohen, R.D.

    1989-01-01

    New intermediate-resolution spectroscopy for six members of a sample of 68 moderate- to high-redshift QSOs is presented. Evidence is reported which indicates that seven strong absorption features in the QSO spectra are due to damped Ly-alpha absorption. A standard curve-of-growth analysis on five of the damped systems is performed, and relevant properties are tabulated and discussed. Six of the seven damped Ly-alpha systems have H I column densities of 2 x 10 to the 20th/sq cm or larger, while the remaining system has an H I column density of about 10 to the 20th/sq cm. It is suggested that damped Ly-alpha systems arise when a sight line intercepts a high-redshift protogalaxy disk containing a quiescent cloud component characterized by high column density and low effective velocity dispersion. At the same time, the sight line usually intercepts a broader turbulent component, which is identified as the halo, characterized by much lower column density and higher effective velocity dispersion. 42 refs

  18. The TESIS Project: Are Type 2 QSO Hidden in X-Ray Emitting EROs?

    Science.gov (United States)

    Severgnini, P.; Della Ceca, R.; Braito, V.; Saracco, P.; Longhetti, M.; Bender, R.; Drory, N.; Feulner, G.; Hopp, U.; Mannucci, F.; Maraston, C.

    X-ray selected EROs are, on average, the hardest X-ray sources in medium and deep X-ray fields. This coupled with their extremely red colors (R-K > 5) suggest that they represent one of the most promising population where looking for high-luminosity (LX > 1044 erg s-1) and X-ray obscured (NH > 1022 cm-2) type2 AGNs, the so called QSO2 (e.g., [5]; [4]; Mignoli et al. submitted to A&A). These latter are predicted in large density by the synthesis model of the Cosmic X-ray background [9] even if only few observational evidences have been found so far (e.g., [1] and references therein; Caccianiga et al. A&A accepted).

  19. The pharmacokinetic profile of tamsulosin oral controlled absorption system (OCAS((R)))

    NARCIS (Netherlands)

    Michel, M. C.; Korstanje, C.; Krauwinkel, W.; Kuipers, M.

    2005-01-01

    Context: A new formulation of tamsulosin for the treatment of lower urinary tract symptoms suggestive of benign prostatic hyperplasia (LUTS/BPH) has been developed. This formulation uses the proprietary oral controlled absorption system (OCAS(R)) technology which has the potential to better control

  20. Pharmacokinetics and Pharmacodynamics of Tamsulosin in its Modified-Release and Oral Controlled Absorption System Formulations

    NARCIS (Netherlands)

    Franco-Salinas, Gabriela; de La Rosette, Jean J. M. C. H.; Michel, Martin C.

    2010-01-01

    Tamsulosin is an alpha(1)-adrenoceptor antagonist used for the treatment of lower urinary tract symptoms that are suggestive of benign prostatic hyperplasia. It is mostly used in a modified-release (M R) Formulation. but an oral controlled absorption system (OCAS) and a 'without-water' tablet

  1. Nonlinear absorption of fullerene- and nanotubes-doped liquid crystal systems

    Czech Academy of Sciences Publication Activity Database

    Kamanina, N.; Reshak, Ali H; Vasiliev, P.Y.; Vangonen, A. I.; Studeonov, V. I.; Usanov, Y. E.; Ebothe, J.; Gondek, E.; Wojcik, W.; Danel, A.

    2009-01-01

    Roč. 41, č. 3 (2009), s. 391-394 ISSN 1386-9477 Institutional research plan: CEZ:AV0Z60870520 Keywords : nonlinear absorption properties * organic electrooptical systems * liquid crystal * fullerene s * nanotubes * PVK-derivatives Subject RIV: BO - Biophysics Impact factor: 1.177, year: 2009

  2. Study of an absorption machine for an ammonia-water system ...

    African Journals Online (AJOL)

    This paper deals with Study of an absorption machine for an ammonia-water system decentralized trigeneration. The effects of evaporator, absorber and boiler temperature on the coefficient of performance of this cycle investigate. Simulation results show that with increasing the evaporator and absorber temperature the ...

  3. Mapping Quantitatively Regional Drug Absorption in Canines with IntelliCap System

    NARCIS (Netherlands)

    Becker, D.; Schütz, H.; Beyerbach, A.; Zou, H.; Shimizu, J.; Iordanov, V.P.

    2011-01-01

    Quantitative regional absorption of a drug under development was studied by using the novel IntelliCap system. IntelliCap is an orally swallowable programmable drug delivery capsule and capable of real-time monitoring of physiological conditions (pH, temperature), consequently allowing localization

  4. Nature and statistical properties of quasar associated absorption systems in the XQ-100 Legacy Survey

    DEFF Research Database (Denmark)

    Perrotta, Serena; D'Odorico, Valentina; Prochaska, J. Xavier

    2016-01-01

    We statistically study the physical properties of a sample of narrow absorption line (NAL) systems looking for empirical evidences to distinguish between intrinsic and intervening NALs without taking into account any a priori definition or velocity cut-off. We analyze the spectra of 100 quasars...

  5. How to take absorptive surfaces into account when designing outdoor sound reinforcement systems

    DEFF Research Database (Denmark)

    Rasmussen, Karsten bo

    1996-01-01

    When sound reinforcement systems are used outdoors, absorptive surfaces are usually present along the propagation path of the sound. This may lead to a very significant colouration of the spectrum received by the audience. The colouration depends on the location and directivity of the loudspeaker......, the nature of the absorptive surface (eg grass) and the location of the audience. It is discussed how this effect may be calculated and numerical examples are shown. The results show a significant colouration and attenuation of the sound due to grass-covered surfaces....

  6. Efficient atom localization via probe absorption in an inverted-Y atomic system

    Science.gov (United States)

    Wu, Jianchun; Wu, Bo; Mao, Jiejian

    2018-06-01

    The behaviour of atom localization in an inverted-Y atomic system is theoretically investigated. For the atoms interacting with a weak probe field and several orthogonal standing-wave fields, their position information can be obtained by measuring the probe absorption. Compared with the traditional scheme, we couple the probe field to the transition between the middle and top levels. It is found that the probe absorption sensitively depends on the detuning and strength of the relevant light fields. Remarkably, the atom can be localized at a particular position in the standing-wave fields by coupling a microwave field to the transition between the two ground levels.

  7. Portable Instrument to Measure CDOM Light Absorption in Aquatic Systems: WPI Success Story

    Science.gov (United States)

    2001-01-01

    World Precision Instruments, Inc. (WPI), of Sarasota, FL, in collaboration with NASA's John C. Stennis Space Center, has developed an innovative instrument to accurately measure Colored Dissolved Organic Matter (CDOM) absorption in the field. This successful collaboration has culminated in an exciting new device, called the UltraPath, now commercially available through WPI. Traditional methods of measuring absorption of dissolved materials require special handling and storage prior to measurement. Use of laboratory spectrophotometers as the measuring devices have proven time consuming, cumbersome, and delicate to handle. The UltraPath provides a low-cost, highly sensitive, rugged, portable system that is capable of high sensitivity measurements in widely divergent waters.

  8. Ab-sorption machines for heating and cooling in future energy systems - Final report

    Energy Technology Data Exchange (ETDEWEB)

    Tozer, R.; Gustafsson, M.

    2000-12-15

    After the Executive Summary and a brief introductory chapter, Chapter 2, Sorption Technologies for Heating and Cooling in Future Energy Systems, reviews the main types of sorption systems. Chapter 3, Market Segmentation, then considers the major segments of the market including residential, commercial/institutional and industrial, and the types of sorption hardware most suitable to each. The highly important residential and commercial/institutional markets are mostly concerned with air-conditioning of buildings. More applications are identified and discussed for the industrial market, including refrigeration, food-storage cooling, process cooling, and process heating at various temperature ranges from hot water for hand-washing to high-temperature (greater than 130C). Other interesting industrial applications are absorption cooling or heating combined with co-generation, desiccant cooling, gas turbine inlet air cooling, combining absorption chillers with district heating systems, direct-fired absorption heat pumps (AHPs), and a closed greenhouse concept being developed for that economically important sector in the Netherlands. Most of the sorption market at this time comprises direct-fired absorption chillers, or hot water or steam absorption chillers indirectly driven by direct-fired boilers. Throughout the report, this category of absorption chillers is referred to generically as 'direct-fired'. In addition, this report covers absorption (reversible) heat pumps, absorption heat transformers, compression-absorption heat pumps, and adsorption chillers and heat pumps. Adsorption systems together with desiccant systems are also addressed. Chapter 4, Factors Affecting the Market, considers economic, environmental and policy issues. The geographical make-up of the world sorption market is then reviewed, followed by a number of practical operating and control considerations. These include vacuum requirements, crystallisation, corrosion, maintenance, health and

  9. Hybrid compression/absorption type heat utilization system (eco-energy city project)

    Energy Technology Data Exchange (ETDEWEB)

    Karimata, T.; Susami, S.; Ogawa, Y. [Research and Development Dept., EBARA Corp., Kanagawa pref. (Japan)

    1999-07-01

    This research is intended to develop a 'hybrid compression/absorption type heat utilization system' by combining an absorption process with a compression process in one circulation cycle. This system can produce chilling heat for ice thermal storage by utilizing low-temperature waste heat (lower than 100 C) which is impossible to treat with a conventional absorption chiller. It means that this system will be able to solve the problem of a timing mismatch between waste heat and heat demand. The working fluid used in this proposed system should be suitable for producing ice, be safe, and not damage the ozone layer. In this project, new working fluids were searched as substitutes for the existing H{sub 2}O/LiBr or NH{sub 3}/H{sub 2}O. The interim results of this project in 1997, a testing unit using NH{sub 3}/H{sub 2}O was built for demonstration of the system and evaluation of its characteristics, and R134a/E181 was found to be one of the good working fluid for this system. The COP (ratio of energy of ice produced to electric power provided) of this system using R134a/E181 is expected to achieve 5.5 by computer simulation. The testing unit with this working fluid was built recently and prepared for the tests to confirm the result of the simulation. (orig.)

  10. Thermodynamic performance analysis of gas-fired air-cooled adiabatic absorption refrigeration systems

    International Nuclear Information System (INIS)

    Wang, L.; Chen, G.M.; Wang, Q.; Zhong, M.

    2007-01-01

    In China, the application of small size gas-fired air-cooled absorption refrigeration systems as an alternative for electric compression air conditioning systems has shown broad prospects due to occurrence of electricity peak demand in Chinese big cities and lack of water resources. However, for conventional air-cooled absorption refrigeration systems, it is difficult to enhance the heat and mass transfer process in the falling film absorber, and may cause problems, for example, remarkable increase of pressure, temperature and concentration in the generators, risk of crystallization, acceleration of corrosion, degradation of performance, and so on. This paper presents a gas-fired air-cooled adiabatic absorption refrigeration system using lithium bromide-water solutions as its working fluid, which is designed with a cooling capacity of 16 kW under standard conditions. The system has two new features of waste heat recovery of condensed water from generator and an adiabatic absorber with an air cooler. Performance simulation and characteristic analysis are crucial for the optimal control and reliability of operation in extremely hot climates. A methodology is presented to simulate thermodynamic performance of the system. The influences of outdoor air temperature on operation performances of the system are investigated

  11. Use of a parallel artificial membrane system to evaluate passive absorption and elimination in small fish.

    Science.gov (United States)

    Kwon, Jung-Hwan; Katz, Lynn E; Liljestrand, Howard M

    2006-12-01

    A parallel artificial lipid membrane system was developed to mimic passive mass transfer of hydrophobic organic chemicals in fish. In this physical model system, a membrane filter-supported lipid bilayer separates two aqueous phases that represent the external and internal aqueous environments of fish. To predict bioconcentration kinetics in small fish with this system, literature absorption and elimination rates were analyzed with an allometric diffusion model to quantify the mass transfer resistances in the aqueous and lipid phases of fish. The effect of the aqueous phase mass transfer resistance was controlled by adjusting stirring intensity to mimic bioconcentration rates in small fish. Twenty-three simple aromatic hydrocarbons were chosen as model compounds for purposes of evaluation. For most of the selected chemicals, literature absorption/elimination rates fall into the range predicted from measured membrane permeabilities and elimination rates of the selected chemicals determined by the diffusion model system.

  12. Design of absorption system water-ammonia by using solar radiation as thermal source

    Energy Technology Data Exchange (ETDEWEB)

    Cavalcanti, Eduardo J. Cidade; Souza, Luiz Guilherme Meira [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil). Centro de Tecnlogia. Dept. de Engenharia Mecanica], E-mails: educanti@gmail.com, lguilherme@dem.ufrn.br

    2010-07-01

    An absorption refrigeration system with the single effect of par ammonia water with 1.758 kW (1 / 2 RT) cooling capacity was designed. The system was operating under conditions of 5 degree C evaporation and 45 degree C condensation temperature. The absorption system has a heat exchanger to improve performance. The heat source is the cylinder parabolic solar concentrator (CPC). The design of the concentrator was estimated based on experimental data of the pilot plant built in the Solar Energy Laboratory, Federal University of Rio Grande do Norte. The thermodynamic model with heat and mass transfer was made to the project areas of heat exchange (absorber) and consequent construction of the system. The rectifying column was modeling assuming that liquid is in equilibrium with the vapor state in all plate. The results should show the dimensions of the compact and allows a future assessment of the operational cost. (author)

  13. Two-dimensional atom localization via probe absorption in a four-level atomic system

    International Nuclear Information System (INIS)

    Wang Zhi-Ping; Ge Qiang; Ruan Yu-Hua; Yu Ben-Li

    2013-01-01

    We have investigated the two-dimensional (2D) atom localization via probe absorption in a coherently driven four-level atomic system by means of a radio-frequency field driving a hyperfine transition. It is found that the detecting probability and precision of 2D atom localization can be significantly improved via adjusting the system parameters. As a result, our scheme may be helpful in laser cooling or the atom nano-lithography via atom localization

  14. Designing the lithium bromide air conditioning absorption system for a bus

    International Nuclear Information System (INIS)

    Yusoff Ali; Kamaruzzaman Sopian; Hariadi

    2006-01-01

    A system of air-conditioning using Lithium Bromide absorption system is used as an alternative refrigerant that will not pollute the atmosphere. Lithium Bromide is a chemical salt soluble in water. There is a big difference between vapour compression system and LiBr 2 absorption system. The absorption air conditioning system is made of a generator, a condenser, an evaporator and an absorber with necessary pumps and piping. When LiBr 2 solution is heated under low pressure, water will evaporate first, while LiBr 2 will remain in the solution and will become more concentrated. The water is the refrigerant in this system. The generator, where the water is vapourised, is heated using an electric heater or solar energy. The LiBr 2 weak solution under low pressure in the generator is heated and the water evaporate into vapour. The vapour produced is then cooled in the condenser and then expanded into the evaporator. The refrigerant (water) in evaporator change phase from liquid to vapour by absorbing heat from cooling water, which flow in the coil in the evaporator. The chilled water obtained is then pumped into the fan coil, which will be used in conditioning the passenger area of the bus. The water vapour from the evaporator is absorbed into LiBr 2 solution in the absorber, forming a weak solution of LiBr 2 . the weak solution from the absorber is then pumped back to the generator to regenerate. The absorption system does not use compressor, but requires pumps that need lower input power compared to that of a compressor. The system is considered as a new application for the bus. This will have great potential and will be environmentally friendly. The model in this study will be used for calculation of the cooling load for the bus

  15. ORIGINS OF ABSORPTION SYSTEMS OF CLASSICAL NOVA V2659 CYG (NOVA CYG 2014)

    Energy Technology Data Exchange (ETDEWEB)

    Arai, A.; Kawakita, H. [Koyama Astronomical Observatory, Kyoto Sangyo University, Motoyama, Kamigamo, Kita-ku, Kyoto 603-8555 (Japan); Shinnaka, Y. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Tajitsu, A., E-mail: arai6a@cc.kyoto-su.ac.jp [Subaru Telescope, National Astronomical Observatory of Japan, 650 North A’ohoku Place, Hilo, Hawaii 96720 (United States)

    2016-10-10

    We report on high-dispersion spectroscopy results of a classical nova V2659 Cyg (Nova Cyg 2014) that are taken 33.05 days after the V -band maximum. The spectrum shows two distinct blueshifted absorption systems originating from H i, Fe ii, Ca ii, etc. The radial velocities of the absorption systems are −620 km s{sup −1}, and −1100 to −1500 km s{sup −1}. The higher velocity component corresponds to the P-Cygni absorption features frequently observed in low-resolution spectra. Much larger numbers of absorption lines are identified at the lower velocity. These mainly originate from neutral or singly ionized Fe-peak elements (Fe i, Ti ii, Cr ii, etc.). Based on the results of our spectroscopic observations, we discuss the structure of the ejecta of V2659 Cyg. We conclude that the low- and high-velocity components are likely to be produced by the outflow wind and the ballistic nova ejecta, respectively.

  16. Spectral control of an alexandrite laser for an airborne water-vapor differential absorption lidar system

    Science.gov (United States)

    Ponsardin, Patrick; Grossmann, Benoist E.; Browell, Edward V.

    1994-01-01

    A narrow-linewidth pulsed alexandrite laser has been greatly modified for improved spectral stability in an aircraft environment, and its operation has been evaluated in the laboratory for making water-vapor differential absorption lidar measurements. An alignment technique is described to achieve the optimum free spectral range ratio for the two etalons inserted in the alexandrite laser cavity, and the sensitivity of this ratio is analyzed. This technique drastically decreases the occurrence of mode hopping, which is commonly observed in a tunable, two-intracavity-etalon laser system. High spectral purity (greater than 99.85%) at 730 nm is demonstrated by the use of a water-vapor absorption line as a notch filter. The effective cross sections of 760-nm oxygen and 730-nm water-vapor absorption lines are measured at different pressures by using this laser, which has a finite linewidth of 0.02 cm(exp -1) (FWHM). It is found that for water-vapor absorption linewidths greater than 0.04 cm(exp -1) (HWHM), or for altitudes below 10 km, the laser line can be considered monochromatic because the measured effective absorption cross section is within 1% of the calculated monochromatic cross section. An analysis of the environmental sensitivity of the two intracavity etalons is presented, and a closed-loop computer control for active stabilization of the two intracavity etalons in the alexandrite laser is described. Using a water-vapor absorption line as a wavelength reference, we measure a long-term frequency drift (approximately 1.5 h) of less than 0.7 pm in the laboratory.

  17. Graphical expression of thermodynamic characteristics of absorption process in ammonia-water system

    Directory of Open Access Journals (Sweden)

    Fortelný Zdeněk

    2012-04-01

    Full Text Available The adiabatic sorption is very interesting phenomenon that occurs when vapor of refrigerant is in contact with unsaturated liquid absorbent-refrigerant mixture and exchange of heat is forbid between the system and an environment. This contribution introduces new auxiliary lines that enable correct position determination of the adiabatic sorption process in the p-T-x diagram of ammoniawater system. The presented auxiliary lines were obtained from common functions for fast calculation of water-ammonia system properties. Absorption cycles designers often utilize p-t-x diagrams of working mixtures for first suggestion of new absorption cycles. The p-t-x diagrams enable fast correct determination of saturate states of liquid (and gaseous mixtures of refrigerants and absorbents. The working mixture isn’t only at saturated state during a real working cycle. If we know pressure and temperature of an unsaturated mixture, exact position determination is possible in the p-t-x diagrams too.

  18. [Signal analysis and spectrum distortion correction for tunable diode laser absorption spectroscopy system].

    Science.gov (United States)

    Bao, Wei-Yi; Zhu, Yong; Chen, Jun; Chen, Jun-Qing; Liang, Bo

    2011-04-01

    In the present paper, the signal of a tunable diode laser absorption spectroscopy (TDLAS) trace gas sensing system, which has a wavelength modulation with a wide range of modulation amplitudes, is studied based on Fourier analysis method. Theory explanation of spectrum distortion induced by laser intensity amplitude modulation is given. In order to rectify the spectrum distortion, a method of synchronous amplitude modulation suppression by a variable optical attenuator is proposed. To validate the method, an experimental setup is designed. Absorption spectrum measurement experiments on CO2 gas were carried out. The results show that the residual laser intensity modulation amplitude of the experimental system is reduced to -0.1% of its original value and the spectrum distortion improvement is 92% with the synchronous amplitude modulation suppression. The modulation amplitude of laser intensity can be effectively reduced and the spectrum distortion can be well corrected by using the given correction method and system. By using a variable optical attenuator in the TDLAS (tunable diode laser absorption spectroscopy) system, the dynamic range requirements of photoelectric detector, digital to analog converter, filters and other aspects of the TDLAS system are reduced. This spectrum distortion correction method can be used for online trace gas analyzing in process industry.

  19. A thermodynamic evaluation on high pressure condenser of double effect absorption refrigeration system

    International Nuclear Information System (INIS)

    Yılmaz, İbrahim Halil; Saka, Kenan; Kaynakli, Omer

    2016-01-01

    One of the parameters affecting the COP of the absorption system can be considered as the thermal balance between the high pressure condenser (HPC) and the low pressure generator (LPG) since heat rejected from the HPC is utilized as an energy source by the LPG. Condensation of the water vapor in the HPC depends on the heat removal via the LPG. This circumstance is significant for making an appropriate design and a controllable system with high performance in practical applications. For this reason, a thermodynamic analysis for the HPC of a double effect series flow water/lithium bromide absorption refrigeration system was emphasized in this study. A simulation was developed to investigate the energy transfer between the HPC and LPG. The results show that the proper designation of the HPC temperature improves the COP and ECOP due its significant impact, and its value necessarily has to be higher than the outlet temperature of the LPG based on the operating scheme. Furthermore, the COP and ECOP of the absorption system can be raised in the range of 9.72–35.09% in case of 2 °C-temperature increment in the HPC under the described conditions to be applied. - Highlights: • Thermal balance in HPC/LPG unit of a double effect absorption system was studied. • A simulation program was developed and its outputs were validated. • A parametric study was conducted for a wide range of component temperatures. • Proper designation of the HPC temperature improves the COP and ECOP. • The system performance raised 9.72–35.09% by controlling the HPC temperature.

  20. Cavity ring-down spectroscopy (CRDS) system for measuring atmospheric mercury using differential absorption

    Science.gov (United States)

    Pierce, A.; Obrist, D.; Moosmuller, H.; Moore, C.

    2012-04-01

    Atmospheric elemental mercury (Hg0) is a globally pervasive element that can be transported and deposited to remote ecosystems where it poses — particularly in its methylated form — harm to many organisms including humans. Current techniques for measurement of atmospheric Hg0 require several liters of sample air and several minutes for each analysis. Fast-response (i.e., 1 second or faster) measurements would improve our ability to understand and track chemical cycling of mercury in the atmosphere, including high frequency Hg0 fluctuations, sources and sinks, and chemical transformation processes. We present theory, design, challenges, and current results of our new prototype sensor based on cavity ring-down spectroscopy (CRDS) for fast-response measurement of Hg0 mass concentrations. CRDS is a direct absorption technique that implements path-lengths of multiple kilometers in a compact absorption cell using high-reflectivity mirrors, thereby improving sensitivity and reducing sample volume compared to conventional absorption spectroscopy. Our sensor includes a frequency-doubled, dye-laser emitting laser pulses tunable from 215 to 280 nm, pumped by a Q-switched, frequency tripled Nd:YAG laser with a pulse repetition rate of 50 Hz. We present how we successfully perform automated wavelength locking and stabilization of the laser to the peak Hg0 absorption line at 253.65 nm using an external isotopically-enriched mercury (202Hg0) cell. An emphasis of this presentation will be on the implementation of differential absorption measurement whereby measurements are alternated between the peak Hg0 absorption wavelength and a nearby wavelength "off" the absorption line. This can be achieved using a piezo electric tuning element that allows for pulse-by-pulse tuning and detuning of the laser "online" and "offline" of the Hg absorption line, and thereby allows for continuous correction of baseline extinction losses. Unexpected challenges with this approach included

  1. ASAS-SN Discovery of an Unprecedented >1.5 Magnitude Optical Flare from QSO B0346-279

    Science.gov (United States)

    Vallely, P.; Stanek, K. Z.; Kochanek, C. S.; Shields, J. V.; Thompson, T. A.; Shappee, B. J.; Holoien, T. W.-S.; Prieto, J. L.; Bersier, D.; Dong, Subo; Bose, S.; Chen, Ping; Stritzinger, M.

    2018-02-01

    During the ongoing All Sky Automated Survey for SuperNovae (ASAS-SN, Shappee et al. 2014), using data from the quadruple 14-cm "Brutus" telescope in Haleakala, Hawaii, the quadruple 14-cm "Leavitt" telescope in Fort Davis, Texas, the quadruple 14-cm "Payne-Gaposchkin" telescope in Sutherland, South Africa, and the quadruple 14-cm "Cassius" and "Paczynski" telescopes in Cerro Tololo, Chile, we have discovered an unprecedented optical brightening of QSO B0346-279 (z 0.9874).

  2. Open absorption system for cooling and air conditioning using membrane contactors - Final report

    Energy Technology Data Exchange (ETDEWEB)

    Conde-Petit, M. [M. Conde Engineering, Zuerich (Switzerland); Weber, R.; Dorer, V. [Swiss Federal Laboratories for Materials Testing and Research (EMPA), Duebendorf (Switzerland)

    2008-07-01

    Air conditioning systems based upon the open absorption principle, essentially an absorption device operating at atmospheric pressure, have been proposed and investigated at many instances in the past eighty years. Their potential for improving energy efficiency is clearly recognized in the earliest research reports. By the mid 1950ies, solar thermal energy was being applied to drive open absorption-based air conditioning systems. For several reasons, however, the open absorption technology was not mature enough to take place in the mainstream. In the past two decades, vigorous efforts have been undertaken to reverse this situation, but success continued to elude, despite the fact that the main problems, such as corrosion, aerosols in the supply air, etc., have been identified. This report details the work and the main results from the MemProDEC Project. In this project innovative solutions were proposed, and successfully investigated, for the corrosion problem and the improvement of efficiency of the absorption process, in particular a new method to cool a very compact absorber. The practically uniform flow distribution for all three streams in the absorber (air, water and desiccant) warrants the contact of the air to be dehumidified with the desiccant over the whole surface of exchange (across a porous membrane). This, together with the cooling with water in counter flow to the air, are the key factors for the excellent effectiveness of the absorber. As the results show, the dehydration effectiveness of the prototype absorber is up to 150 % higher than that previously obtained by others. The solutions developed for compactness and modularity represent an important step in the way to flexible manufacturing, i.e. using a single element size to assemble autonomous air handling units of various nominal capacities. And although the manufacturing methods of the individual elements require improvement, namely by avoiding adhesive bonding, the choice of materials and the

  3. Energy and exergy analysis of a double effect absorption refrigeration system based on different heat sources

    International Nuclear Information System (INIS)

    Kaynakli, Omer; Saka, Kenan; Kaynakli, Faruk

    2015-01-01

    Highlights: • Energy and exergy analysis was performed on double effect series flow absorption refrigeration system. • The refrigeration system runs on various heat sources such as hot water, hot air and steam. • A comparative analysis was carried out on these heat sources in terms of exergy destruction and mass flow rate of heat source. • The effect of heat sources on the exergy destruction of high pressure generator was investigated. - Abstract: Absorption refrigeration systems are environmental friendly since they can utilize industrial waste heat and/or solar energy. In terms of heat source of the systems, researchers prefer one type heat source usually such as hot water or steam. Some studies can be free from environment. In this study, energy and exergy analysis is performed on a double effect series flow absorption refrigeration system with water/lithium bromide as working fluid pair. The refrigeration system runs on various heat sources such as hot water, hot air and steam via High Pressure Generator (HPG) because of hot water/steam and hot air are the most common available heat source for absorption applications but the first law of thermodynamics may not be sufficient analyze the absorption refrigeration system and to show the difference of utilize for different type heat source. On the other hand operation temperatures of the overall system and its components have a major effect on their performance and functionality. In this regard, a parametric study conducted here to investigate this effect on heat capacity and exergy destruction of the HPG, coefficient of performance (COP) of the system, and mass flow rate of heat sources. Also, a comparative analysis is carried out on several heat sources (e.g. hot water, hot air and steam) in terms of exergy destruction and mass flow rate of heat source. From the analyses it is observed that exergy destruction of the HPG increases at higher temperature of the heat sources, condenser and absorber, and lower

  4. Determining CDOM Absorption Spectra in Diverse Aquatic Environments Using a Multiple Pathlength, Liquid Core Waveguide System

    Science.gov (United States)

    Miller, Richard L.; Belz, Mathias; DelCastillo, Carlos; Trzaska, Rick

    2001-01-01

    We evaluated the accuracy, sensitivity and precision of a multiple pathlength, liquid core waveguide (MPLCW) system for measuring colored dissolved organic matter (CDOM) absorption in the UV-visible spectral range (370-700 nm). The MPLCW has four optical paths (2.0, 9.8, 49.3, and 204 cm) coupled to a single Teflon AF sample cell. Water samples were obtained from inland, coastal and ocean waters ranging in salinity from 0 to 36 PSU. Reference solutions for the MPLCW were made having a refractive index of the sample. CDOM absorption coefficients, aCDOM, and the slope of the log-linearized absorption spectra, S, were compared with values obtained using a dual-beam spectrophotometer. Absorption of phenol red secondary standards measured by the MPLCW at 558 nm were highly correlated with spectrophotometer values and showed a linear response across all four pathlengths. Values of aCDOM measured using the MPLCW were virtually identical to spectrophotometer values over a wide range of concentrations. The dynamic range of aCDOM for MPLCW measurements was 0.002 - 231.5 m-1. At low CDOM concentrations spectrophotometric aCDOM were slightly greater than MPLCW values and showed larger fluctuations at longer wavelengths due to limitations in instrument precision. In contrast, MPLCW spectra followed an exponential to 600 nm for all samples.

  5. Effect of resin system on the mechanical properties and water absorption of kenaf fibre reinforced laminates

    International Nuclear Information System (INIS)

    Rassmann, S.; Paskaramoorthy, R.; Reid, R.G.

    2011-01-01

    The objective of this study is to compare the mechanical and water absorption properties of kenaf (Hibiscus cannabinus L.) fibre reinforced laminates made of three different resin systems. The use of different resin systems is considered so that potentially complex and expensive fibre treatments are avoided. The resin systems used include a polyester, a vinyl ester and an epoxy. Laminates of 15%, 22.5% and 30% fibre volume fraction were manufactured by resin transfer moulding. The laminates were tested for strength and modulus under tensile and flexural loading. Additionally, tests were carried out on laminates to determine the impact energy, impact strength and water absorption. The results revealed that properties were affected in markedly different ways by the resin system and the fibre volume fraction. Polyester laminates showed good modulus and impact properties, epoxy laminates displayed good strength values and vinyl ester laminates exhibited good water absorption characteristics. Scanning electron microscope studies show that epoxy laminates fail by fibre fracture, polyester laminates by fibre pull-out and vinyl ester laminates by a combination of the two. A comparison between kenaf and glass laminates revealed that the specific tensile and flexural moduli of both laminates are comparable at the volume fraction of 15%. However, glass laminates have much better specific properties than the kenaf laminates at high fibre volume fractions for all three resins used.

  6. Tunable Absorption System based on magnetorheological elastomers and Halbach array: design and testing

    Energy Technology Data Exchange (ETDEWEB)

    Bocian, Mirosław; Kaleta, Jerzy; Lewandowski, Daniel, E-mail: daniel.lewandowski@pwr.edu.pl; Przybylski, Michał

    2017-08-01

    Highlights: • Construction of a Tunable Absorption System incorporating MRE has been done. • For system control by magnetic field a double circular Halbach array has been used. • Significant changes of the TSAs natural frequency and damping has been obtained. - Abstract: In this paper, the systematic design, construction and testing of a Tunable Absorption System (TAS) incorporating magnetorheological elastomer (MRE) has been investigated. The TAS has been designed for energy absorption and mitigation of vibratory motions from an impact excitation. The main advantage of the designed TAS is that it has the ability to change and adapt to working conditions. Tunability can be realised through a change in the magnetic field caused by the change of an internal arrangement of permanent magnets within a double dipolar circular Halbach array. To show the capabilities of the tested system, experiments based on an impulse excitation have been performed. Significant changes of the TASs natural frequency and damping characteristics have been obtained. By incorporating magnetic tunability within the TAS a significant qualitative and quantitative change in the devices mechanical properties and performance were obtained.

  7. Evidence of Primordial Clustering around the QSO SDSS J1030+0524 at z=6.28

    Science.gov (United States)

    Stiavelli, M.; Djorgovski, S. G.; Pavlovsky, C.; Scarlata, C.; Stern, D.; Mahabal, A.; Thompson, D.; Dickinson, M.; Panagia, N.; Meylan, G.

    2005-03-01

    We present tentative evidence of primordial clustering, manifested as an excess of color-selected objects in the field of the QSO SDSS J1030+0524 at redshift z=6.28. We have selected objects red in i775-z850 on the basis of Hubble Space Telescope Advanced Camera for Surveys imaging of a field centered on the QSO. Compared to data at comparable depth obtained by the Great Observatories Origins Deep Survey, we find an excess of objects with i775-z850>=1.5 in the QSO field. The significance of the detection is estimated to be ~97% on the basis of the counts alone and increases to 99.4% if one takes into account the color distribution. If confirmed, this would represent the highest redshift example of galaxy clustering and would have implications on models for the growth of structure. Bias-driven clustering of first luminous objects forming in the highest peaks of the primordial density field is expected in most models of early structure formation. The redshift of one of the candidates has been found to be z=5.970 by our spectroscopy with the Keck I Low Resolution Imaging Spectrometer, confirming the validity of our color selection. Based, in part, on data obtained at the W. M. Keck Observatory, which is operated as a scientific partnership between the California Institute of Technology, the University of California, and NASA, and was made possible by the generous financial support of the W. M. Keck Foundation.

  8. The importance of the ammonia purification process in ammonia-water absorption systems

    International Nuclear Information System (INIS)

    Fernandez-Seara, Jose; Sieres, Jaime

    2006-01-01

    Practical experience in working with ammonia-water absorption systems shows that the ammonia purification process is a crucial issue in order to obtain an efficient and reliable system. In this paper, the detrimental effects of the residual water content in the vapour refrigerant are described and quantified based on the system design variables that determine the effectiveness of the purification process. The study has been performed considering a single stage system with a distillation column with complete condensation. The ammonia purification effectiveness of the column is analysed in terms of the efficiencies in the stripping and rectifying sections and the reflux ratio. By varying the efficiencies from 0 to 1, systems with neither the rectifying nor stripping section, with either the rectifying or stripping section, or with both sections can be considered. The impact of the ammonia purification process on the absorption system performance is studied based on the column efficiencies and reflux ratio; and its effects on refrigerant concentration, system COP, system pressures and main system mass flow rates and concentrations are analysed. When the highest efficiency rectifying sections are used a combination of generation temperature and reflux ratio which leads to optimum COP values is found. The analysis covers different operating conditions with air and water cooled systems from refrigeration to air conditioning applications by changing the evaporation temperature. The importance of rectification in each kind of application is evaluated

  9. Differential Optical-absorption Spectroscopy (doas) System For Urban Atmospheric-pollution Monitoring

    OpenAIRE

    Edner, H; Ragnarson, P; Spannare, S; Svanberg, Sune

    1993-01-01

    We describe a fully computer-controlled differential optical absorption spectroscopy system for atmospheric air pollution monitoring. A receiving optical telescope can sequentially tune in to light beams from a number of distant high-pressure Xe lamp light sources to cover the area of a medium-sized city. A beam-finding servosystem and automatic gain control permit unattended long-time monitoring. Using an astronomical code, we can also search and track celestial sources. Selected wavelength ...

  10. Connecting the Interstellar Gas and Dust Properties in Distant Galaxies Using Quasar Absorption Systems

    Science.gov (United States)

    Aller, Monique C.; Dwek, Eliahu; Kulkarni, Varsha P.; York, Donald G.; Welty, Daniel E.; Vladilo, Giovanni; Som, Debopam; Lackey, Kyle; Dwek, Eli; Beiranvand, Nassim; hide

    2016-01-01

    Gas and dust grains are fundamental components of the interstellar medium and significantly impact many of the physical processes driving galaxy evolution, such as star-formation, and the heating, cooling, and ionization of the interstellar material. Quasar absorption systems (QASs), which trace intervening galaxies along the sightlines to luminous quasars, provide a valuable tool to directly study the properties of the interstellar gas and dust in distant, normal galaxies. We have established the presence of silicate dust grains in at least some gas-rich QASs, and find that they exist at higher optical depths than expected for diffuse gas in the Milky Way. Differences in the absorption feature shapes additionally suggest variations in the silicate dust grain properties, such as in the level of grain crystallinity, from system-to-system. We present results from a study of the gas and dust properties of QASs with adequate archival IR data to probe the silicate dust grain properties. We discuss our measurements of the strengths of the 10 and 18 micron silicate dust absorption features in the QASs, and constraints on the grain properties (e.g., composition, shape, crystallinity) based on fitted silicate profile templates. We investigate correlations between silicate dust abundance, reddening, and gas metallicity, which will yield valuable insights into the history of star formation and chemical enrichment in galaxies.

  11. Simultaneous multi-element atomic absorption system using photodiode array detector

    International Nuclear Information System (INIS)

    Tong, S.L.; Chin, K.S.

    1994-01-01

    A photodiode array (PDA) detector-multichannel analyser (MCA) system has been coupled to a flame and a graphite furnace atomiser and tested for simultaneous multielement atomic absorption analysis. Multielement hollow cathode lamps (HCL) are used as light source. Spectral lines are dispersed through a spectrograph with triple gratings and detected by a 25.4 mm PDA detector consisting of 1024 elements. The optical MCA system is capable of recording multiple spectra spanned by the spectrograph/PDA. The transmitted intensity spectra obtained for the standard and analyte solutions during flame or graphite furnace atomisation are converted to absorbance spectra using the MCA software provided. Results from the comparison studies show that the linear range and sensitivities for Ni-Co-Fe and Cu-Cr obtained from the simultaneous measurements are within the same order of magnitudes as those from conventional single element determinations using photomultiplier tube detection. The study also shows that non-atomic absorption can be readily corrected by a two-line method where non-atomic absorption lines can be chosen from the spectra recorded simultaneously. The proposed system has been evaluated for the determination of trace elements using NBS standard reference water SRM 1643b

  12. Triple-effect absorption refrigeration system with double-condenser coupling

    Science.gov (United States)

    DeVault, Robert C.; Biermann, Wendell J.

    1993-01-01

    A triple effect absorption refrigeration system is provided with a double-condenser coupling and a parallel or series circuit for feeding the refrigerant-containing absorbent solution through the high, medium, and low temperature generators utilized in the triple-effect system. The high temperature condenser receiving vaporous refrigerant from the high temperature generator is double coupled to both the medium temperature generator and the low temperature generator to enhance the internal recovery of heat within the system and thereby increase the thermal efficiency thereof.

  13. Evaluation of trigeneration system using microturbine, ammonia-water absorption chiller, and a heat recovery boiler

    Energy Technology Data Exchange (ETDEWEB)

    Preter, Felipe C.; Rocha, Marcelo S.; Simoes-Moreira, Jose Roberto [SISEA - Alternative Energy Systems Lab. Dept. of Mechanical Engineering. University of Sao Paulo (EP/USP), SP (Brazil)], e-mails: felipe.preter@poli.usp.br, msrocha@poli.usp.br, jrsimoes@usp.br; Andreos, Ronaldo [COMGAS - Companhia de Gas de Sao Paulo, SP (Brazil)], e-mail: randreos@comgas.com.br

    2010-07-01

    In this work, a CCHP or tri generation system has been projected, mounted, and tested in laboratory, combining a microturbine for power generation, a heat recovery boiler for hot water production, and an ammonia water absorption chiller for chilled water production. The project was motivated by the large practical applications of this kind of energy recovery system in commerce, and industry, and, in general, more than 85% of the energy source is used as power, hot water, and cold water. In the first part, the trigeneration system theoretical model is detailed, and in the second part, experimental results are presented for different operation conditions. (author)

  14. Trigeneration System Based on Municipal Waste Gasification, Fuel Cell and an Absorption Chiller

    DEFF Research Database (Denmark)

    Katsaros, Giannis; Nguyen, Tuong-Van; Rokni, Masoud

    2016-01-01

    of a specific building is also investigated and the system can fully meet the electricity and cooling demands, whereas the heat needs can be satisfied only up to 55%. Moreover, assuming 20 years of operation, the payback period is 4.3 years and the net present value exceeds 5 MEUR.......The present work focuses on the design of a novel tri-generation system based on municipal solid wastes gasification, solid oxide fuel cell and an ammonia-water absorption chiller. Trigeneration systems can be implemented in buildings such as hospitals, where there is a continuous and large demand...

  15. The Mean Metal-line Absorption Spectrum of Damped Ly α Systems in BOSS

    Energy Technology Data Exchange (ETDEWEB)

    Mas-Ribas, Lluís [Institute of Theoretical Astrophysics, University of Oslo, Postboks 1029, NO-0315 Oslo (Norway); Miralda-Escudé, Jordi; Pérez-Ràfols, Ignasi; Arinyo-i-Prats, Andreu [Institut de Ciències del Cosmos, Universitat de Barcelona (UB-IEEC), Barcelona E-08028, Catalonia (Spain); Noterdaeme, Pasquier; Petitjean, Patrick [Institut d’Astrophysique de Paris, UPMC and CNRS, UMR7095 98bis Boulevard Arago, F-75014—Paris (France); Schneider, Donald P. [Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States); York, Donald G. [Department of Astronomy and Astrophysics and the Enrico Fermi Institute, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States); Ge, Jian, E-mail: l.m.ribas@astro.uio.no [Department of Astronomy, University of Florida, Bryant Space Science Center, Gainesville, FL 32611-2055 (United States)

    2017-09-01

    We study the mean absorption spectrum of the Damped Ly α (DLA) population at z ∼ 2.6 by stacking normalized, rest-frame-shifted spectra of ∼27,000 DLA systems from the DR12 of the Baryon Oscillation Spectroscopic Survey (BOSS)/SDSS-III. We measure the equivalent widths of 50 individual metal absorption lines in five intervals of DLA hydrogen column density, five intervals of DLA redshift, and overall mean equivalent widths for an additional 13 absorption features from groups of strongly blended lines. The mean equivalent width of low-ionization lines increases with N {sub H} {sub i}, whereas for high-ionization lines the increase is much weaker. The mean metal line equivalent widths decrease by a factor ∼1.1–1.5 from z ∼ 2.1 to z ∼ 3.5, with small or no differences between low- and high-ionization species. We develop a theoretical model, inspired by the presence of multiple absorption components observed in high-resolution spectra, to infer mean metal column densities from the equivalent widths of partially saturated metal lines. We apply this model to 14 low-ionization species and to Al iii, S iii, Si iii, C iv, Si iv, N v, and O vi. We use an approximate derivation for separating the equivalent width contributions of several lines to blended absorption features, and infer mean equivalent widths and column densities from lines of the additional species N i, Zn ii, C ii*, Fe iii, and S iv. Several of these mean column densities of metal lines in DLAs are obtained for the first time; their values generally agree with measurements of individual DLAs from high-resolution, high signal-to-noise ratio spectra when they are available.

  16. Experimental assessment of an absorption cooling system operating with the ammonia/lithium nitrate mixture

    International Nuclear Information System (INIS)

    Hernández-Magallanes, J.A.; Domínguez-Inzunza, L.A.; Gutiérrez-Urueta, G.; Soto, P.; Jiménez, C.; Rivera, W.

    2014-01-01

    This paper reports the experimental results of a single effect absorption cooling system of 3 kW of nominal cooling capacity operating with ammonia–lithium nitrate solution. The system was designed and built in the Instituto de Energías Renovables of the Universidad Nacional Autónoma de México and can be used for food conservation or air conditioning. The absorber and generator are falling film heat exchangers. The condenser, evaporator and solution heat exchanger are compact plate heat exchangers. The heat was supplied to the generator at temperatures between 85 °C and 105 °C, while the cooling water temperatures to remove the heat produced during the condensation and absorption varied between 18 °C and 36 °C. The results showed that the system can produce up to 2.7 kW of cooling capacity at heating water temperatures of 95 °C and can achieve evaporator temperatures as low as 1 °C. The experimental coefficients of performance varied between 0.45 and 0.70. Because of the developed system do not need a rectifier and reasonable good coefficients of performance were achieved, the developed system seems to be a good alternative to be used for food conservation or air conditioning. - Highlights: • An absorption cooling system was developed using NH 3 –LiNO 3 . • The achieved COP (coefficients of performance) are the highest reported for a system using NH 3 –LiNO 3 . • Evaporator temperatures as low as 1 °C were achieved. • COP varied between 0.45 and 0.7. • The developed system seems to be a good alternative for food conservation and air conditioning

  17. Cooling performance and energy saving of a compression-absorption refrigeration system assisted by geothermal energy

    International Nuclear Information System (INIS)

    Kairouani, L.; Nehdi, E.

    2006-01-01

    The objectives of this paper are to develop a novel combined refrigeration system, and to discuss the thermodynamic analysis of the cycle and the feasibility of its practical development. The aim of this work was to study the possibility of using geothermal energy to supply vapour absorption system cascaded with conventional compression system. Three working fluids (R717, R22, and R134a) are selected for the conventional compression system and the ammonia-water pair for the absorption system. The geothermal temperature source in the range 343-349 K supplies a generator operating at 335 K. Results show that the COP of a combined system is significantly higher than that of a single stage refrigeration system. It is found that the COP can be improved by 37-54%, compared with the conventional cycle, under the same operating conditions, that is an evaporation temperature at 263 K and a condensation temperature of 308 K. For industrial refrigeration, the proposed system constitutes an alternative solution for reducing energy consumption and greenhouse gas emissions

  18. NLP model based thermoeconomic optimization of vapor compression–absorption cascaded refrigeration system

    International Nuclear Information System (INIS)

    Jain, Vaibhav; Sachdeva, Gulshan; Kachhwaha, S.S.

    2015-01-01

    Highlights: • It addresses the size and cost estimation of cascaded refrigeration system. • Cascaded system is a promising decarburizing and energy efficient technology. • Second law analysis is carried out with modified Gouy-Stodola equation. • The total annual cost of plant operation is optimized in present work. - Abstract: This paper addresses the size and cost estimation of vapor compression–absorption cascaded refrigeration system (VCACRS) for water chilling application taking R410a and water–LiBr as refrigerants in compression and absorption section respectively which can help the design engineers in manufacturing and experimenting on such kind of systems. The main limitation in the practical implementation of VCACRS is its size and cost which are optimized in the present work by implementing Direct Search Method in non-linear programming (NLP) mathematical model of VCACRS. The main objective of optimization is to minimize the total annual cost of system which comprises of costs of exergy input and capital costs in monetary units. The appropriate set of decision variables (temperature of evaporator, condenser, generator, absorber, cascade condenser, degree of overlap and effectiveness of solution heat exchanger) minimizes the total annual cost of VCACRS by 11.9% with 22.4% reduction in investment cost at the base case whereas the same is reduced by 7.5% with 11.7% reduction in investment cost with reduced rate of interest and increased life span and period of operation. Optimization results show that the more investment cost in later case is well compensated through the performance and operational cost of the system. In the present analysis, optimum cascade condensing temperature is a strong function of period of operation and capital recovery factor. The cascading of compression and absorption systems becomes attractive for lower rate of interest and increase life span and operational period

  19. Experimental assessment of an absorption cooling system utilizing a falling film absorber and generator

    International Nuclear Information System (INIS)

    Domínguez-Inzunza, L.A.; Hernández-Magallanes, J.A.; Soto, P.; Jiménez, C.; Gutiérrez-Urueta, G.; Rivera, W.

    2016-01-01

    Highlights: • A new prototype of an absorption cooling system using NH_3/LiNO_3 was developed. • Falling films shell and tubes heat exchangers were used as absorber and generator. • Evaporator temperatures as low as 4 °C were achieved. • The COP varied between 0.27 and 0.62 depending on the system temperatures. • A flow recirculation in the absorber was implemented showing an increase in COP. - Abstract: This study presents the results of the evaluation of an ammonia/lithium nitrate absorption cooling system. The generator and the absorber are shell and tubes falling film heat exchangers while the rest of the components are compact plate heat exchangers. A parametric study was carried out in order to determine the coefficients of performance and cooling capacities at different operating conditions. Also, an analysis was carried out to determine the influence of the absorber solution recirculation on the system performance. The generator temperatures varied between 80 °C and 100 °C, while the cooling water temperatures varied from 20 °C to 34 °C. Cooling capacities up to 4.5 kW and evaporator temperatures as low as 4 °C were achieved with the system. The internal coefficients of performance varied between 0.3 and 0.62 depending on the system operating temperatures. The system also showed good stability and repeatability.

  20. Wavelet Space-Scale-Decomposition Analysis of QSO's Ly$\\alpha$ Absorption Lines: Spectrum of Density Perturbations

    OpenAIRE

    Pando, Jesus; Fang, Li-Zhi

    1995-01-01

    A method for measuring the spectrum of a density field by a discrete wavelet space-scale decomposition (SSD) has been studied. We show how the power spectrum can effectively be described by the father function coefficients (FFC) of the wavelet SSD. We demonstrate that the features of the spectrum, such as the magnitude, the index of a power law, and the typical scales, can be determined with high precision by the FFC reconstructed spectrum. This method does not require the mean density, which...

  1. Analysis of a multicomponent gas absorption system with carrier gas coabsorption

    International Nuclear Information System (INIS)

    Merriman, J.R.

    1975-03-01

    Conventional integrated versions of the packed gas absorber design equations do not account for significant coabsorption of the carrier gas along with the dilute transferring species. These equations, as a result, also neglect the relationship between dilute component transfer and carrier gas coabsorption. In the absorption of Kr and Xe from various carrier gases, using CCl 2 F 2 as the process solvent, carrier coabsorption is substantial. Consequently, a design package was developed to deal with multicomponent gas absorption in systems characterized by carrier gas coabsorption. Developed within the general film theory framework, the basic feature of this design approach is a view of dilute component mass-transfer as a conventional diffusive transfer superimposed on a net flux caused by carrier absorption. Other supporting elements of the design package include predictive techniques for various fluid properties, estimating procedures for carrier gas equilibrium constants, and correlations for carrier gas and dilute gas mass-transfer coefficients. When applied to systems using CCl 2 F 2 as the solvent; He, N 2 , air, or Ar as the carrier gas; and Kr or Xe as the dilute gas; the design approach gave good results, even when extended to conditions well beyond those of its development. (U.S.)

  2. Dynamic investigation of the diffusion absorption refrigeration system NH3-H2O-H2

    Directory of Open Access Journals (Sweden)

    Mohamed Izzedine Serge Adjibade

    2017-09-01

    Full Text Available This paper reports on a numerical and experimental study of a diffusion absorption refrigerator. The performance of the system is examined by computer simulation using MATLAB software and Engineering Equations Solver. A dynamic model is developed for each component of the system and solved numerically in order to predict the transient state of the diffusion absorption refrigeration. The experiment set included 0.04 m3 commercial absorption diffusion refrigerator working with the ammonia-water-hydrogen (NH3-H2O-H2 solution. The transient numerical results were validated with the experimental data. The investigations are focused on the dynamic profile of the temperature of each component. The results obtained agree with the experiment; the relative error between numerical and experimental models doesn’t exceed 15% for all temperatures of each component. The increase of the average ambient temperature from 23.04 °C to 32.56 °C causes an increase of the condensation temperature from 29.46 °C to 37.51 °C, and the best evaporation temperature obtained was 3 °C, with an ambient temperature of 23.04 °C. The results show that a minimum starting temperature of 152 °C and 63.8 W electric power are required to initiate the decrease of evaporation temperature.

  3. Space Launch System Base Heating Test: Tunable Diode Laser Absorption Spectroscopy

    Science.gov (United States)

    Parker, Ron; Carr, Zak; MacLean, Mathew; Dufrene, Aaron; Mehta, Manish

    2016-01-01

    This paper describes the Tunable Diode Laser Absorption Spectroscopy (TDLAS) measurement of several water transitions that were interrogated during a hot-fire testing of the Space Launch Systems (SLS) sub-scale vehicle installed in LENS II. The temperature of the recirculating gas flow over the base plate was found to increase with altitude and is consistent with CFD results. It was also observed that the gas above the base plate has significant velocity along the optical path of the sensor at the higher altitudes. The line-by-line analysis of the H2O absorption features must include the effects of the Doppler shift phenomena particularly at high altitude. The TDLAS experimental measurements and the analysis procedure which incorporates the velocity dependent flow will be described.

  4. Using waste heat of ship as energy source for an absorption refrigeration system

    International Nuclear Information System (INIS)

    Salmi, Waltteri; Vanttola, Juha; Elg, Mia; Kuosa, Maunu; Lahdelma, Risto

    2017-01-01

    Highlights: • A steady-state thermodynamic model is developed for absorption refrigeration in a ship. • Operation profile of B.Delta37 bulk carrier is used as an initial data. • Suitability of water-LiBr and ammonia-water working pairs were validated. • Coefficient of performance (COP) was studied in ISO and tropical conditions. • Estimated energy savings were 47 and 95 tons of fuel every year. - Abstract: This work presents a steady-state thermodynamic model for absorption refrigeration cycles with water-LiBr and ammonia-water working pairs for purpose of application on a ship. The coefficient of performance was studied with different generator and evaporator temperatures in ISO and tropical conditions. Absorption refrigeration systems were examined using exhaust gases, jacket water, and scavenge air as energy sources. Optimal generator temperatures for different refrigerant temperatures were found using different waste heat sources and for the absorption cycle itself. Critical temperature values (where the refrigeration power drops to zero) were defined. All of these values were used in order to evaluate the cooling power and energy production possibilities in a bulk carrier. The process data of exhaust gases and cooling water flows in two different climate conditions (ISO and tropical) and operation profiles of a B. Delta37 bulk carrier were used as initial data in the study. With the case ship data, a theoretical potential of saving of 70% of the electricity used in accommodation (AC use) compressor in ISO conditions and 61% in tropical conditions was recognized. Those estimates enable between 47 and 95 tons of annual fuel savings, respectively. Moreover, jacket water heat recovery with a water-LiBr system has the potential to provide 2.2–4.0 times more cooling power than required during sea-time operations in ISO conditions, depending on the main engine load.

  5. Experimental investigation on an ammonia-water-lithium bromide absorption refrigeration system without solution pump

    International Nuclear Information System (INIS)

    Wu Tiehui; Wu Yuyuan; Yu Zhiqiang; Zhao Haichen; Wu Honglin

    2011-01-01

    Highlights: → An absorption refrigeration system with ternary solution of NH 3 -H 2 O-LiBr was set up. → Performance of the NH 3 -H 2 O-LiBr system without solution pump was firstly tested. → Generator pressure in NH 3 -H 2 O-LiBr system was lower than the one in NH 3 -H 2 O system. → The COP of the NH 3 -H 2 O-LiBr system was 51.89% larger than the NH 3 -H 2 O binary system. → The optimum mass fraction of LiBr of about 23% led to the largest COP of 0.401. -- Abstract: Experimental researches were carried out on a novel ammonia-water-lithium bromide ternary solution absorption refrigeration and air-conditioning system without solution pump and distillation equipments. The experiments were conducted by using three kinds of NH 3 -H 2 O binary solution and 17 kinds of ternary solution with difference in mass fraction of NH 3 and LiBr. The experimental results showed that the vapor pressure of the generator in the system would be lower than that of the generator in an ammonia-water absorption system. In above two situations the same ammonia mass fraction and the same solution temperature were kept. The amplitude of vapor pressure decrease of the system generator would be larger with the increase of the mass fraction of LiBr. The maximum amplitude of decrease would be of 50%. With the increase of the mass fraction of LiBr, the coefficient of performance (COP) of the system would be increased initially, and then decreased later when the mass fraction of LiBr exceeded a certain value. This value was about 23% for the solution with ammonia mass fraction of 50% and 55%, and about 30% for the solution with ammonia mass fraction of 60%. Compared with the ammonia-water system, the COP of the ternary solution system with the same mass fraction of ammonia would increase up to 30%. With the ammonia mass fraction of 60% and LiBr mass fraction of 30% applied, the COP of the ternary solution system was increased up to 0.401. It was 51.89% higher than that when binary

  6. Moisture absorption characteristics of the Orbiter thermal protection system and methods used to prevent water ingestion

    Science.gov (United States)

    Schomburg, C.; Dotts, R. L.; Tillian, D. J.

    1983-01-01

    The Space Shuttle Orbiter's silica tile Thermal Protection System (TPS) is beset by the moisture absorption problems inherently associated with low density, highly porous insulation systems. Attention is presently given to the comparative success of methods for the minimization and/or prevention of water ingestion by the TPS tiles, covering the development of water-repellent agents and their tile application techniques, flight test program results, and materials improvements. The use of external films for rewaterproofing of the TPS tiles after each mission have demonstrated marginal to unacceptable performance. By contrast, a tile interior waterproofing agent has shown promise.

  7. Second law comparison of single effect and double effect vapour absorption refrigeration systems

    International Nuclear Information System (INIS)

    Gomri, Rabah

    2009-01-01

    In this paper a comparative study between single effect and double effect absorption refrigeration systems with identical cold output is carried out. Simulation results were used to study the influence of the various operating parameters on the performance coefficient, the thermal loads of the components, exergetic efficiency (rational efficiency) and the total change in exergy of the two systems. It is concluded that the COP of double effect system is approximately twice the COP of single effect system but the exergetic efficiency of double effect system increase slightly compared to the exergetic efficiency of single effect system. It is found that for each condenser and evaporator temperature, there is an optimum generator temperature where the total change in exergy of the single effect and double effect absorption refrigeration systems is minimum. At this point the COP and exergetic efficiency of the systems become maximum. In this study and when the evaporation temperature is varied from 4 deg. C to 10 deg. C, condenser and absorber temperatures are varied from 33 deg. C to 39 deg. C and generator (HPG) temperature is varied from 60 deg. C to 190 deg. C the maximum COP values of the single effect refrigeration systems are in the range of 0.73-0.79 and for double effect refrigeration systems are in the range of 1.22-1.42. The maximum exergetic efficiency values of the single effect refrigeration systems are in the range of 12.5-23.2% and for double effect refrigeration systems are in the range of 14.3-25.1%.

  8. An In Silico Knockout Model for Gastrointestinal Absorption Using a Systems Pharmacology Approach - Development and Application for Ketones.

    Directory of Open Access Journals (Sweden)

    Vittal Shivva

    Full Text Available Gastrointestinal absorption and disposition of ketones is complex. Recent work describing the pharmacokinetics (PK of d-β-hydroxybutyrate (BHB following oral ingestion of a ketone monoester ((R-3-hydroxybutyl (R-3-hydroxybutyrate found multiple input sites, nonlinear disposition and feedback on endogenous production. In the current work, a human systems pharmacology model for gastrointestinal absorption and subsequent disposition of small molecules (monocarboxylic acids with molecular weight < 200 Da was developed with an application to a ketone monoester. The systems model was developed by collating the information from the literature and knowledge gained from empirical population modelling of the clinical data. In silico knockout variants of this systems model were used to explore the mechanism of gastrointestinal absorption of ketones. The knockouts included active absorption across different regions in the gut and also a passive diffusion knockout, giving 10 gut knockouts in total. Exploration of knockout variants has suggested that there are at least three distinct regions in the gut that contribute to absorption of ketones. Passive diffusion predominates in the proximal gut and active processes contribute to the absorption of ketones in the distal gut. Low doses are predominantly absorbed from the proximal gut by passive diffusion whereas high doses are absorbed across all sites in the gut. This work has provided mechanistic insight into the absorption process of ketones, in the form of unique in silico knockouts that have potential for application with other therapeutics. Future studies on absorption process of ketones are suggested to substantiate findings in this study.

  9. Mathematical Model of a Lithium-Bromide/Water Absorption Refrigeration System Equipped with an Adiabatic Absorber

    Directory of Open Access Journals (Sweden)

    Salem M. Osta-Omar

    2016-11-01

    Full Text Available The objective of this paper is to develop a mathematical model for thermodynamic analysis of an absorption refrigeration system equipped with an adiabatic absorber using a lithium-bromide/water (LiBr/water pair as the working fluid. The working temperature of the generator, adiabatic absorber, condenser, evaporator, the cooling capacity of the system, and the ratio of the solution mass flow rate at the circulation pump to that at the solution pump are used as input data. The model evaluates the thermodynamic properties of all state points, the heat transfer in each component, the various mass flow rates, and the coefficient of performance (COP of the cycle. The results are used to investigate the effect of key parameters on the overall performance of the system. For instance, increasing the generator temperatures and decreasing the adiabatic absorber temperatures can increase the COP of the cycle. The results of this mathematical model can be used for designing and sizing new LiBr/water absorption refrigeration systems equipped with an adiabatic absorber or for optimizing existing aforementioned systems.

  10. Optimization of operation of energy supply systems with co-generation and absorption refrigeration

    Directory of Open Access Journals (Sweden)

    Stojiljković Mirko M.

    2012-01-01

    Full Text Available Co-generation systems, together with absorption refrigeration and thermal storage, can result in substantial benefits from the economic, energy and environmental point of view. Optimization of operation of such systems is important as a component of the entire optimization process in pre-construction phases, but also for short-term energy production planning and system control. This paper proposes an approach for operational optimization of energy supply systems with small or medium scale co-generation, additional boilers and heat pumps, absorption and compression refrigeration, thermal energy storage and interconnection to the electric utility grid. In this case, the objective is to minimize annual costs related to the plant operation. The optimization problem is defined as mixed integer nonlinear and solved combining modern stochastic techniques: genetic algorithms and simulated annealing with linear programming using the object oriented “ESO-MS” software solution for simulation and optimization of energy supply systems, developed as a part of this research. This approach is applied to optimize a hypothetical plant that might be used to supply a real residential settlement in Niš, Serbia. Results are compared to the ones obtained after transforming the problem to mixed 0-1 linear and applying the branch and bound method.

  11. A CCD-based system for the detection of DNA in electrophoresis gels by UV absorption

    International Nuclear Information System (INIS)

    Mahon, A.R.; MacDonald, J.H.; Mainwood, A.; Ott, R.J.

    1999-01-01

    A method and apparatus for the detection and quantification of large fragments of unlabelled nucleic acids in agarose gels is presented. The technique is based on ultraviolet (UV) absorption by nucleotides. A deuterium source illuminates individual sample lanes of an electrophoresis gel via an array of optical fibres. As DNA bands pass through the illuminated region of the gel the amount of UV light transmitted is reduced because of absorption by the DNA. During electrophoresis the regions of DNA are detected on-line using a UV-sensitive charge coupled device (CCD). As the absorption coefficient is proportional to the mass of DNA the technique is inherently quantitative. The mass of DNA in a region of the gel is approximately proportional to the integrated signal in the corresponding section of the CCD image. This system currently has a detection limit of less than 1.25 ng compared with 2-10 ng for the most popular conventional technique, ethidium bromide (EtBr) staining. In addition the DNA sample remains in its native state. The removal of the carcinogenic dye from the detection procedure greatly reduces associated biological hazards. (author)

  12. Experimental investigation on photothermal properties of nanofluids for direct absorption solar thermal energy systems

    International Nuclear Information System (INIS)

    He, Qinbo; Wang, Shuangfeng; Zeng, Shequan; Zheng, Zhaozhi

    2013-01-01

    Highlights: • The factors affecting the transmittance of Cu–H 2 O nanofluids were studied with UV–Vis–NIR spectrophotometer. • The optical properties of Cu–H 2 O nanofluids were studied through the theoretical model. • The Cu–H 2 O nanofluids can enhance the absorption ability for solar energy. - Abstract: In this article, Cu–H 2 O nanofluids were prepared through two-step method. The transmittance of nanofluids over solar spectrum (250–2500 nm) was measured by the UV–Vis–NIR spectrophotometer based on integrating sphere principle. The factors influencing transmittance of nanofluids, such as particle size, mass fraction and optical path were investigated. The extinction coefficients measured experimentally were compared with the theoretical calculation value. Meanwhile, the photothermal properties of nanofluids were also investigated. The experimental results show that the transmittance of Cu–H 2 O nanofluids is much less than that of deionized water, and decreases with increasing nanoparticle size, mass fraction and optical depth. The highest temperature of Cu–H 2 O nanofluids (0.1 wt.%) can increased up to 25.3% compared with deionized water. The good absorption ability of Cu–H 2 O nanofluids for solar energy indicates that it is suitable for direct absorption solar thermal energy systems

  13. Enhancement of absorption and hepatoprotective potential through soya-phosphatidylcholine-andrographolide vesicular system.

    Science.gov (United States)

    Jain, Pushpendra Kumar; Khurana, Navneet; Pounikar, Yogesh; Gajbhiye, Asmita; Kharya, Murli Dhar

    2013-06-01

    Andrographis paniculata is a medicinal herb used extensively for various ailments and contains therapeutically active phytoconstituent, andrographolide (AN). Although hepatoprotective activity of AN is established, but their bioavailability is restricted due to its rapid clearance. The aim of this study, therefore, was to formulate AN herbosomes (ANH) through complexation with naturally occurring soya-phosphatidylcholine (SPC), in order to enhance absorption. Prepared andrographolide-soy phosphatidylcholine (AN-SPC) complex prepared was subjected for characterisation of complex and formation of vesicular system known as ANH using rotary evaporation techniques. This complex was subjected to in vitro study using everted small intestine sac technique which showed significantly increased absorption of AN from the ANH as compared to the plain AN. The hepatoprotective potential of ANH and plain AN was evaluated using carbon tetrachloride inducing hepatotoxicity rat model and compared, in which ANH equivalent to 50 mg/kg of plain AN significantly restore serum glutamate oxalacetate transaminase (112.4 ± 9.67 for AN whereas 90.2 ± 4.23 for ANH) and serum glutamate pyruvate transaminase (109.3 ± 7.89 for AN whereas 90.6 ± 4.34 for ANH) level as compared to control group. The ANH showed significantly better absorption than plain AN and this effect of ANH was also comparable to the standard drug (Silymarin). The findings of present study reveal that ANH has better bioavailability as shown by in vitro absorption study and hence improved hepatoprotection as compared to plain AN at equivalent dose.

  14. Thermo- economical consideration of Regenerative organic Rankine cycle coupling with the absorption chiller systems incorporated in the trigeneration system

    International Nuclear Information System (INIS)

    Anvari, Simin; Taghavifar, Hadi; Parvishi, Alireza

    2017-01-01

    Highlights: • A new trigeneration cycle was studied from a new viewpoint of exergoeconomic and thermodynamic. • Organic Rankine and refrigeration cycles are used for recovery waste heat of cogeneration system. • Application of trigeneration cycles is advantageous in economical and thermodynamic aspects. - Abstract: In this paper, a combined cooling, heating and power cycle is proposed consisting of three sections of gas turbine and heat recovery steam generator cycle, Regenerative organic Rankine cycle, and absorption refrigeration cycle. This trigeneration cycle is subjected to a thorough thermodynamic and exergoeconomic analysis. The principal goal followed in the investigation is to address the thermodynamic and exergoeconomic of a trigeneration cycle from a new prospective such that the economic and thermodynamic viability of incorporating Regenerative organic Rankine cycle, and absorption refrigeration cycle to the gas turbine and heat recovery steam generator cycle is being investigated. Thus, the cost-effectiveness of the introduced method can be studied and further examined. The results indicate that adding Regenerative organic Rankine cycle to gas turbine and heat recovery steam generator cycle leads to 2.5% increase and the addition of absorption refrigeration cycle to the gas turbine and heat recovery steam generator/ Regenerative Organic Rankine cycle would cause 0.75% increase in the exergetic efficiency of the entire cycle. Furthermore, from total investment cost of the trigeneration cycle, only 5.5% and 0.45% results from Regenerative organic Rankine cycle and absorption refrigeration cycles, respectively.

  15. Analysis of a gas absorption system with soluble carrier gas and volatile solvent

    International Nuclear Information System (INIS)

    Kanak, B.E.

    1980-01-01

    The effects of column diameter, carrier gas coabsorption, and solvent vaporization on the performance of a packed gas absorption column are examined. The system investigated employs dichlorodifluoromethane as a solvent to remove krypton from a nitrogen stream and is characterized by substantial nitrogen coabsorption. Three columns with diameters of 2, 3, and 4 inches were constructed and packed with 34.5 inches of Goodloe packing. In addition to the more conventional data, the experimental evaluation of these columns included the use of a radioisotope and a gamma scanning technique which provided direct measurement of the columns' molar krypton profiles. A multicomponent gas absorption model was developed, based on the two-film mass transfer theory, that allows the fluxes of all species to interact. Verification of this model was achieved through comparison of the calculated results with experimental data. With the feed gas flow rate between 6 and 36 lb moles/hr-ft 2 and the solvent feed rate between 40 and 400 lb moles/hr-ft 2 , column diameter was found to have no significant impact on the mass transfer efficiency of this system when carried out in columns with diameters of 2 inches or greater. The absorption of krypton was found to be enhanced and inhibited, respectively, by carrier gas coabsorption and solvent vaporization. An injector system to add gaseous solvent to the feed gas stream prior to its introduction into the packed bed was proposed to eliminate the detrimental effects of solvent vaporization.Using this injector to supersaturate the feed gas stream with solvent enhanced absorber performance in the same manner as carrier gas coabsorption

  16. A solar absorption refrigeration system operating with the mixture ammonia-lithium nitrate

    Energy Technology Data Exchange (ETDEWEB)

    Rivera, W.; Martinez, F.; Garcia-Valladares, O. [Centro de Investigacion en Energia de la Univ. Nacional Autonoma de Mexico, Mor (Mexico); Rivera, C.O. [Univ. Veracruzana, Campus Coatzacoalcos (Mexico)

    2007-07-01

    An intermittent solar absorption refrigeration system for ice production operating with the ammonia-lithium nitrate mixture has been developed in the Centro de Investigacion en Energia of the Universidad Nacional Autonoma de Mexico. The system consists basically of a compound parabolic concentrator (CPC), a generator-absorber, a condenser, a condensate tank, an expansion valve and an evaporator. The system was evaluated in sunny days with insolations above 20 MJ/m{sup 2}-day at different condenser temperatures. The generator temperatures varied from 108 to 121 C and the evaporator temperatures inside the camera from -8 to 0 C. The coefficients of performance (COP) varied from 0.13 to 0.26 depending of the operating temperatures of the system and the solar irradiation. (orig.)

  17. The standard calibration instrument automation system for the atomic absorption spectrophotometer. Part 3: Program documentation

    Science.gov (United States)

    Ryan, D. P.; Roth, G. S.

    1982-04-01

    Complete documentation of the 15 programs and 11 data files of the EPA Atomic Absorption Instrument Automation System is presented. The system incorporates the following major features: (1) multipoint calibration using first, second, or third degree regression or linear interpolation, (2) timely quality control assessments for spiked samples, duplicates, laboratory control standards, reagent blanks, and instrument check standards, (3) reagent blank subtraction, and (4) plotting of calibration curves and raw data peaks. The programs of this system are written in Data General Extended BASIC, Revision 4.3, as enhanced for multi-user, real-time data acquisition. They run in a Data General Nova 840 minicomputer under the operating system RDOS, Revision 6.2. There is a functional description, a symbol definitions table, a functional flowchart, a program listing, and a symbol cross reference table for each program. The structure of every data file is also detailed.

  18. Investigation of periodically driven systems by x-ray absorption spectroscopy using asynchronous data collection mode

    Science.gov (United States)

    Singh, H.; Donetsky, D.; Liu, J.; Attenkofer, K.; Cheng, B.; Trelewicz, J. R.; Lubomirsky, I.; Stavitski, E.; Frenkel, A. I.

    2018-04-01

    We report the development, testing, and demonstration of a setup for modulation excitation spectroscopy experiments at the Inner Shell Spectroscopy beamline of National Synchrotron Light Source - II. A computer algorithm and dedicated software were developed for asynchronous data processing and analysis. We demonstrate the reconstruction of X-ray absorption spectra for different time points within the modulation pulse using a model system. This setup and the software are intended for a broad range of functional materials which exhibit structural and/or electronic responses to the external stimulation, such as catalysts, energy and battery materials, and electromechanical devices.

  19. Implications of a primordial origin for the dispersion in D/H in quasar absorption systems.

    Science.gov (United States)

    Copi, C J; Olive, K A; Schramm, D N

    1998-03-17

    We explore the difficulties with a primordial origin of variations of D/H in quasar absorption systems. In particular we examine options such as a very large-scale inhomogeneity in the baryon content of the universe. We show that very large-scale (much larger than 1 Mpc) isocurvature perturbations are excluded by current cosmic microwave background observations. Smaller-scale ad hoc perturbations (approximately 1 Mpc) still may lead to a large dispersion in primordial abundances but are subject to other constraints.

  20. Absorption spectra of thin films of triple compounds in the system RbIPbI2

    International Nuclear Information System (INIS)

    Yunakova, O.N.; Miloslavskij, V.K.; Ksenofontova, E.V.; Kovalenko, E.N.

    2012-01-01

    A formation of compounds RbPbI 3 and Rb 4 PbI 6 in the system RbI-PbI 2 is revealed and their absorption spectra are investigated in an energy interval 2-6 eV and a temperatures range 90-500 K. It is established that the low-frequency exciton excitations are localized in PbI 6 4- structural elements of the crystal lattice, they are classified as excitons of intermediate coupling and are of a three-dimensional character in RbPbI 3 and a quasi-two-dimensional one in Rb 4 PbI 6 .

  1. Thermodynamic performance analysis of a vapor compression–absorption cascaded refrigeration system

    International Nuclear Information System (INIS)

    Jain, Vaibhav; Kachhwaha, S.S.; Sachdeva, Gulshan

    2013-01-01

    Highlights: • Study includes first and second law analysis with alternatives refrigerants. • Power consumption in cascaded system is 61% less than vapor compression system. • COP of compression system is improved by 155% with cascaded absorption system. • Condenser is more sensitive to external fluid temperature as compare to evaporator. - Abstract: In the present study, a thermodynamic model for cascaded vapor compression–absorption system (CVCAS) has been developed which consists of a vapor compression refrigeration system (VCRS) coupled with single effect vapor absorption refrigeration system (VARS). Based on first and second laws, a comparative performance analysis of CVCAS and an independent VCRS has been carried out for a design capacity of 66.67 kW. The results show that the electric power consumption in CVCAS is reduced by 61% and COP of compression section is improved by 155% with respect to the corresponding values pertaining to a conventional VCRS. However there is a trade-off between these parameters and the rational efficiency which is found to decrease to half of that for a VCRS. The effect of various operating parameters, i.e., superheating, subcooling, cooling capacity, inlet temperature and the product of effectiveness and heat capacitance of external fluids are extensively studied on the COP, total irreversibility and rational efficiency of the CVCAS. Besides, the performance of environment friendly refrigerants such as R410A, R407C and R134A is found to be almost at par with that of R22. Hence, all the alternative refrigerants selected herein can serve as potential substitutes for R22. Furthermore, it has been found that reducing the irreversibility rate of the condenser by one unit due to decrease in condenser temperature depicted approximately 3.8 times greater reduction in the total irreversibility rate of the CVCAS, whereas unit reduction in the evaporator’s irreversibility rate due to increase in evaporator temperature reduced

  2. Exergy analysis of single effect absorption refrigeration systems: The heat exchange aspect

    International Nuclear Information System (INIS)

    Joybari, Mahmood Mastani; Haghighat, Fariborz

    2016-01-01

    Highlights: • Exergy analysis of LiBr/H 2 O absorption systems with identical COP was carried out. • Exergy destruction rank: absorber followed by generator, condenser and evaporator. • Lower heat source and chilled water inlet temperature reduced exergy destruction. • Higher cooling water inlet temperature reduced exergy destruction. • Lower HTF mass flow rate increased exergy efficiency even for fixed system COP. - Abstract: The main limitation of conventional energy analysis for the thermal performance of energy systems is that this approach does not consider the quality of energy. On the other hand, exergy analysis not only provides information about the systems performance, but also it can specify the locations and magnitudes of losses. A number of studies investigated the effect of parameters such as the component temperature, and heat transfer fluid (HTF) temperature and mass flow rate on the exergetic performance of the same absorption refrigeration system; thus, reported different coefficient of performance (COP) values. However, in this study, the system COP was considered to remain constant during the investigation. This means comparing systems with different heat exchanger designs (based on HTF mass flow rate and temperature) having the same COP value. The effect of HTF mass flow rate and inlet temperature of the cooling water, chilled water and heat source on the outlet specific exergy and exergy destruction rate of each component was investigated. It was found that the lower HTF mass flow rate decreased exergy destruction of the corresponding component. Moreover, the lower temperature of heat source and chilled water inlet increased the system exergetic efficiency. That was also the case for the higher cooling water inlet temperature. Based on the analysis, since the absorber and condenser accounted for a large portion of the total exergy destruction, cooling tower modification with lower cooling water mass flow rate is recommended

  3. Simulation of solar lithium bromide-water absorption cooling system with parabolic trough collector

    International Nuclear Information System (INIS)

    Mazloumi, M.; Naghashzadegan, M.; Javaherdeh, K.

    2008-01-01

    Ahwaz is one of the sweltering cities in Iran where an enormous amount of energy is being consumed to cool residential places in a year. The aim of this research is to simulate a solar single effect lithium bromide-water absorption cooling system in Ahwaz. The solar energy is absorbed by a horizontal N-S parabolic trough collector and stored in an insulated thermal storage tank. The system has been designed to supply the cooling load of a typical house where the cooling load peak is about 17.5 kW (5 tons of refrigeration), which occurs in July. A thermodynamic model has been used to simulate the absorption cycle. The working fluid is water, which is pumped directly to the collector. The results showed that the collector mass flow rate has a negligible effect on the minimum required collector area, but it has a significant effect on the optimum capacity of the storage tank. The minimum required collector area was about 57.6 m 2 , which could supply the cooling loads for the sunshine hours of the design day for July. The operation of the system has also been considered after sunset by saving solar energy

  4. The Research on Programmable Control System of Lithium-Bromide Absorption Refrigerating Air Conditioner Based on the Network

    Directory of Open Access Journals (Sweden)

    Sun Lunan

    2016-01-01

    Full Text Available This article regard the solar lithium-bromide absorption refrigerating air conditioning system as the research object, and it was conducting adequate research of the working principle of lithium bromide absorption refrigerating machine, also it was analyzing the requirements of control system about solar energy air conditioning. Then the solar energy air conditioning control system was designed based on PLC, this system was given priority to field bus control system, and the remote monitoring is complementary, which was combining the network remote monitoring technology. So that it realized the automatic control and intelligent control of new lithium bromide absorption refrigerating air conditioning system with solar energy, also, it ensured the control system can automatically detect and adjust when the external conditions was random changing, to make air conditioning work effectively and steadily, ultimately ,it has great research significance to research the air conditioning control system with solar energy.

  5. Energy and parametric analysis of solar absorption cooling systems in various Moroccan climates

    Directory of Open Access Journals (Sweden)

    Y. Agrouaz

    2017-03-01

    Full Text Available The aim of this work is to investigate the energetic performance of a solar cooling system using absorption technology under Moroccan climate. The solar fraction and the coefficient of performance of the solar cooling system were evaluated for various climatic conditions. It is found that the system operating in Errachidia shows the best average annual solar fraction (of 30% and COP (of 0.33 owing to the high solar capabilities of this region. Solar fraction values in other regions varied between 19% and 23%. Moreover, the coefficient of performance values shows in the same regions a significant variation from 0.12 to 0.33 all over the year. A detailed parametric study was as well carried out to evidence the effect of the operating and design parameters on the solar air conditioner performance.

  6. Open absorption system for cooling and air conditioning using membrane contactors. 2006 annual report

    Energy Technology Data Exchange (ETDEWEB)

    Conde-Petit, M. [M. Conde Engineering, Zuerich (Switzerland); Weber, R. [Materials Science and Technology (EMPA), Abteilung Bautechnologien, Duebendorf (Switzerland)

    2006-11-15

    This illustrated annual report for 2006 for the Swiss Federal Office of Energy (SFOE) reports on work being done on the development of an open absorption system for cooling and air-conditioning. The report reviews the construction of a first prototype and the manufacture of its components. The conceptual design of this new type of air handling unit (AHU), operating with a liquid desiccant, is discussed. The AHU is to be autonomous and the system will not require additional mechanical refrigeration. It is to be thermally driven at temperatures below 80 {sup o}C. Waste heat sources, solar collectors, district heating plants and co-generation systems are targeted as providers of thermal energy at this temperature level. Work carried out is reported on, including that on two-stream membrane contactors.

  7. Thermodynamic analysis of a combined gas turbine, ORC cycle and absorption refrigeration for a CCHP system

    International Nuclear Information System (INIS)

    Mohammadi, Amin; Kasaeian, Alibakhsh; Pourfayaz, Fathollah; Ahmadi, Mohammad Hossein

    2017-01-01

    Highlights: • Thermodynamic analysis of a hybrid CCHP system. • Sensitivity analysis is performed on the most important parameters of the system. • Pressure ratio and gas turbine inlet temperature are the most effective parameters. - Abstract: Hybrid power systems are gained more attention due to their better performance and higher efficiency. Widespread use of these systems improves environmental situation as they reduce the amount of fossil fuel consumption. In this paper a hybrid system composed of a gas turbine, an ORC cycle and an absorption refrigeration cycle is proposed as a combined cooling, heating and power system for residential usage. Thermodynamic analysis is applied on the system. Also a parametric analysis is carried out to investigate the effect of different parameters on the system performance and output cooling, heating and power. The results show that under design conditions, the proposed plant can produce 30 kW power, 8 kW cooling and almost 7.2 ton hot water with an efficiency of 67.6%. Moreover, parametric analysis shows that pressure ratio and gas turbine inlet temperature are the most important and influential parameters. After these two, ORC turbine inlet temperature is the most effective parameter as it can change both net output power and energy efficiency of the system.

  8. Application of vacuum membrane distillation to lithium bromide absorption refrigeration system

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zanshe; Feng, Shiyu; Li, Yun [School of Energy and Power Engineering, Xi' an Jiaotong University, Xi' an 710049 (China); Gu, Zhaolin [School of Human Settlement and Civil Engineering, Xi' an Jiaotong University, Xi' an 710049 (China)

    2009-11-15

    Conventional generator in lithium bromide absorption refrigeration system is too bulky and heavy to be fitted into small scale device, and the temperature of the driving heater in the generator seems much higher than low grade energy such as regenerative energy or waste heat energy. In this paper, desorption of aqueous lithium bromide solution by vacuum membrane distillation process was presented. Hollow fiber membrane module made by polyvinylidene fluoride was used as desorption device of aqueous lithium bromide solution. Influencing factors of feed flux, feed temperature in lumen side and vacuum pressure in shell side were tested and analyzed with orthogonal test. The results showed that permeation flux of water vapor increased with the feed temperature increasing and the feed flux increasing in lumen side, and the permeation flux also went up along with absolute pressure drop in shell side. Feasibility and potential application analysis shows that the temperature of the driving heat was low and the volume and weight of the desorption device was light. In this study, vacuum membrane distillation to the lithium bromide absorption refrigeration system has proved to be an efficient and cheap desorption mode. (author)

  9. A Lack of Systemic Absorption Following the Repeated Application of Topical Quetiapine in Healthy Adults.

    Science.gov (United States)

    Kayhart, Bryce; Lapid, Maria I; Nelson, Sarah; Cunningham, Julie L; Thompson, Virginia H; Leung, Jonathan G

    2018-01-01

    In the absence of suitable oral or intravenous access for medication administration and when the intramuscular medications are undesirable, alternative routes for drug delivery may be considered. Antipsychotics administered via an inhaled, intranasal, rectal, or topical route have been described in the literature. Topically administered antipsychotics have been previously reported to produce negligible systemic absorption despite being used in clinical practice for nausea and behavioral symptoms associated with dementia. Additionally, the American Academy of Hospice and Palliative Medicine recommends against the use of topical medications that lack supporting literature. Three studies have assessed the systemic absorption of different antipsychotics after administration of only a single, topically applied dose. To evaluate whether the repeated administration of a topically applied antipsychotic may result in detectable serum levels in an accumulating fashion, a pharmacokinetic study was conducted. Five healthy, adult participants consented to receive extemporaneously prepared topical quetiapine in Lipoderm every 4 hours for a total of 5 doses. Blood samples were drawn at baseline and hours 2, 4, 8, 12, 16, and 24, and serum quetiapine concentrations were measured using high-performance liquid chromatography. Quetiapine was undetectable in every sample from 3 participants. Two participants had minimally detectable serum quetiapine levels no sooner than hour 12 of the study period. Extemporaneously prepared quetiapine in Lipoderm resulted in nonexistent or minimal serum level following repeated topical administration. The use of topically applied quetiapine should still be questioned.

  10. Continuous optical measurement system of hemolysis during a photosensitization reaction using absorption spectrum

    Science.gov (United States)

    Hamada, R.; Ogawa, E.; Arai, T.

    2018-02-01

    To investigate hemolysis phenomena during a photosensitization reaction with the reaction condition continuously and simultaneously for a safety assessment of hemolysis side effect, we constructed an optical system to measure blood sample absorption spectrum during the reaction. Hemolysis degree might be under estimated in general evaluation methods because there is a constant oxygen pressure assumption in spite of oxygen depression take place. By investigating hemoglobin oxidation and oxygen desorption dynamics obtained from the contribution of the visible absorption spectrum and multiple regression analysis, both the hemolysis phenomena and its oxygen environment might be obtained with time. A 664 nm wavelength laser beam for the reaction excitation and 475-650 nm light beam for measuring the absorbance spectrum were arranged perpendicularly crossing. A quartz glass cuvette with 1×10 mm in dimensions for the spectrum measurement was located at this crossing point. A red blood cells suspension medium was arranged with low hematocrit containing 30 μg/ml talaporfin sodium. This medium was irradiated up to 40 J/cm2 . The met-hemoglobin, oxygenatedhemoglobin, and deoxygenated-hemoglobin concentrations were calculated by a multiple regression analysis from the measured spectra. We confirmed the met-hemoglobin concentration increased and oxygen saturation decreased with the irradiation time, which seems to indicate the hemolysis progression and oxygen consumption, respectively. By using our measuring system, the hemolysis progression seems to be obtained with oxygen environment information.

  11. Experimental investigation of integrated refrigeration system (IRS) with gas engine, compression chiller and absorption chiller

    International Nuclear Information System (INIS)

    Sun, Z.G.

    2008-01-01

    An integrated refrigeration system (IRS) with a gas engine, a vapor-compression chiller and an absorption chiller is set up and tested. The vapor-compression refrigeration cycle is operated directly by the gas engine. The waste heat from the gas engine operates the absorption refrigeration cycle, which provides additional cooling. The performance of the IRS is described. The cooling capacity of the IRS is about 596 kW, and primary energy ratio (PER) reaches 1.84 at air-conditioning rated conditions. The refrigerating capacity of the prototype increased and PER of prototype decreased with the increase of the gas engine speed. The gas engine speed was preferably regulated at part load condition in order to operate the prototype at high-energy efficiency. The refrigerating capacity and PER of the prototype increased with the increase of the outlet temperature of chilled water or the decrease of the inlet temperature of cooling water. The integrated refrigeration chiller in this work saves running costs as compared to the conventional refrigeration system by using the waste heat

  12. Corneal Absorption of a New Riboflavin-Nanostructured System for Transepithelial Collagen Cross-Linking

    Science.gov (United States)

    Bottos, Katia M.; Oliveira, Anselmo G.; Bersanetti, Patrícia A.; Nogueira, Regina F.; Lima-Filho, Acácio A. S.; Cardillo, José A.; Schor, Paulo; Chamon, Wallace

    2013-01-01

    Corneal collagen cross-linking (CXL) has been described as a promising therapy for keratoconus. According to standard CXL protocol, epithelium should be debrided before treatment to allow penetration of riboflavin into the corneal stroma. However, removal of the epithelium can increase procedure risks. In this study we aim to evaluate stromal penetration of a biocompatible riboflavin-based nanoemulsion system (riboflavin-5-phosphate and riboflavin-base) in rabbit corneas with intact epithelium. Two riboflavin nanoemulsions were developed. Transmittance and absorption coefficient were measured on corneas with intact epithelia after 30, 60, 120, 180, and 240 minutes following exposure to either the nanoemulsions or standard 0.1% or 1% riboflavin-dextran solutions. For the nanoemulsions, the epithelium was removed after measurements to assure that the riboflavin had passed through the hydrophobic epithelium and retained within the stroma. Results were compared to de-epithelialized corneas exposed to 0.1% riboflavin solution and to the same riboflavin nanoemulsions for 30 minutes (standard protocol). Mean transmittance and absorption measured in epithelialized corneas receiving the standard 0.1% riboflavin solution did not reach the levels found on the debrided corneas using the standard technique. Neither increasing the time of exposure nor the concentration of the riboflavin solution from 0.1% to 1% improved riboflavin penetration through the epithelium. When using riboflavin-5-phosphate nanoemulsion for 240 minutes, we found no difference between the mean absorption coefficients to the standard cross-linking protocol (p = 0.54). Riboflavin nanoemulsion was able to penetrate the corneal epithelium, achieving, after 240 minutes, greater stromal concentration when compared to debrided corneas with the standard protocol (p = 0.002). The riboflavin-5-phosphate nanoemulsion diffused better into the stroma than the riboflavin-base nanoemulsion. PMID:23785497

  13. Identification of MgII Absorption Line Systems from SDSS Quasar ...

    Indian Academy of Sciences (India)

    Motivation. The quasar absorption lines are crucial to our understanding of the Universe since the absorption lines provide a wealth of information on the gaseous Universe from high redshift to present day. The absorption lines can also allow us to probe the metallicity and ionization state of the gas (Wild et al. 2008).

  14. Inhibition of two-photon absorption in a three-level system with a pair of bichromatic fields

    International Nuclear Information System (INIS)

    Zou Jinhua; Hu Xiangming; Cheng Guangling; Li Xing; Du Dan

    2005-01-01

    We study two-photon absorption in a three-level ladder atomic system driven by a pair of bichromatic fields of equal frequency differences. The high-frequency component of one bichromatic field and the low-frequency component of the other are on two-photon resonance. The transition probability is calculated by employing the method of harmonic expansion and matrix inversion. Unexpectedly, when the sums of the phases of the different pairs of field components on the two-photon resonance are equal to each other, two-photon absorption is dramatically suppressed and the atomic system becomes transparent against two-photon absorption. Physically, due to dynamical Stark splitting, the two-photon transitions induced by the different pairs of field components experience different dressed states with phase difference of π. As a result, destructive interference occurs between the two pathways and leads to the inhibition of two-photon absorption

  15. Three-dimensional atom localization via probe absorption in a cascade four-level atomic system

    Directory of Open Access Journals (Sweden)

    Zeng Wei

    2018-03-01

    Full Text Available For an atomic system with cascade four-level type, a useful scheme about three-dimensional (3D atom localization is proposed. In our scheme the atomic system is coherently controlled by using a radio-frequency field to couple with two-folded levels under the condition of the existence of probe absorption. Our results show that detecting precision of 3D atom localization may be obviously improved by properly adjusting the frequency detuning and strength of the radio-frequency driving field. So our scheme could be helpful to realize 3D atom localization with high-efficiency and high-precision . In the field of laser cooling or the atom nano-lithography, our studies provide potential applications.

  16. Three-dimensional atom localization via probe absorption in a cascade four-level atomic system

    Science.gov (United States)

    Zeng, Wei; Deng, Li; Chen, Aixi

    2018-03-01

    For an atomic system with cascade four-level type, a useful scheme about three-dimensional (3D) atom localization is proposed. In our scheme the atomic system is coherently controlled by using a radio-frequency field to couple with two-folded levels under the condition of the existence of probe absorption. Our results show that detecting precision of 3D atom localization may be obviously improved by properly adjusting the frequency detuning and strength of the radio-frequency driving field. So our scheme could be helpful to realize 3D atom localization with high-efficiency and high-precision . In the field of laser cooling or the atom nano-lithography, our studies provide potential applications.

  17. Energy and Exergy Based Optimization of Licl-Water Absorption Cooling System

    Directory of Open Access Journals (Sweden)

    Bhargav Pandya

    2017-06-01

    Full Text Available This study presents thermodynamic analysis and optimization of single effect LiCl-H2O absorption cooling system. Thermodynamic models are employed in engineering equation solver to compute the optimum performance parameters. In this study, cut off temperature to operate system has been obtained at various operating temperatures. Analysis depicts that on 3.59 % rise in evaporator temperature, the required cut-off temperature decreased by 12.51%. By realistic comparison between thermodynamic first and second law analysis, optimum generator temperature relative to energy and exergy based prospective has been evaluated. It is found that optimum generator temperature is strong function of evaporator and condenser temperature. Thus, it is feasible to find out optimum generator temperature for various combinations of evaporator and condenser temperatures. Contour plots of optimum generator temperature for several combinations of condenser and absorber temperatures have been also depicted.

  18. Vibration energy absorption in the whole-body system of a tractor operator.

    Science.gov (United States)

    Szczepaniak, Jan; Tanaś, Wojciech; Kromulski, Jacek

    2014-01-01

    Many people are exposed to whole-body vibration (WBV) in their occupational lives, especially drivers of vehicles such as tractor and trucks. The main categories of effects from WBV are perception degraded comfort interference with activities-impaired health and occurrence of motion sickness. Absorbed power is defined as the power dissipated in a mechanical system as a result of an applied force. The vibration-induced injuries or disorders in a substructure of the human system are primarily associated with the vibration power absorption distributed in that substructure. The vibration power absorbed by the exposed body is a measure that combines both the vibration hazard and the biodynamic response of the body. The article presents measurement method for determining vibration power dissipated in the human whole body system called Vibration Energy Absorption (VEA). The vibration power is calculated from the real part of the force-velocity cross-spectrum. The absorbed power in the frequency domain can be obtained from the cross-spectrum of the force and velocity. In the context of the vibration energy transferred to a seated human body, the real component reflects the energy dissipated in the biological structure per unit of time, whereas the imaginary component reflects the energy stored/released by the system. The seated human is modeled as a series/parallel 4-DOF dynamic models. After introduction of the excitation, the response in particular segments of the model can be analyzed. As an example, the vibration power dissipated in an operator has been determined as a function of the agricultural combination operating speed 1.39 - 4.16 ms(-1).

  19. Vibration energy absorption in the whole-body system of a tractor operator

    Directory of Open Access Journals (Sweden)

    Jan Szczepaniak

    2014-06-01

    Full Text Available Many people are exposed to whole-body vibration (WBV in their occupational lives, especially drivers of vehicles such as tractor and trucks. The main categories of effects from WBV are perception degraded comfort interference with activities-impaired health and occurrence of motion sickness. Absorbed power is defined as the power dissipated in a mechanical system as a result of an applied force. The vibration-induced injuries or disorders in a substructure of the human system are primarily associated with the vibration power absorption distributed in that substructure. The vibration power absorbed by the exposed body is a measure that combines both the vibration hazard and the biodynamic response of the body. The article presents measurement method for determining vibration power dissipated in the human whole body system called Vibration Energy Absorption (VEA. The vibration power is calculated from the real part of the force-velocity cross-spectrum. The absorbed power in the frequency domain can be obtained from the cross-spectrum of the force and velocity. In the context of the vibration energy transferred to a seated human body, the real component reflects the energy dissipated in the biological structure per unit of time, whereas the imaginary component reflects the energy stored/released by the system. The seated human is modeled as a series/parallel 4-DOF dynamic models. After introduction of the excitation, the response in particular segments of the model can be analyzed. As an example, the vibration power dissipated in an operator has been determined as a function of the agricultural combination operating speed 1.39 – 4.16 ms[sup] -1 [/sup].

  20. Experimental analysis of a diffusion absorption refrigeration system used alternative energy sources

    International Nuclear Information System (INIS)

    Soezen, A.; Oezbas, E.

    2009-01-01

    The continuous-cycle absorption refrigeration device is widely used in domestic refrigerators, and recreational vehicles. It is also used in year-around air conditioning of both homes and larger buildings. The unit consists of four main parts the boiler, condenser, evaporator and the absorber. When the unit operates on kerosene or gas, the heat is supplied by a burner. This element is fitted underneath the central tube. When operating on electricity, the heat is supplied by an element inserted in the pocket. No moving parts are employed. The operation of the refrigerating mechanism is based on Dalton's law. In this study, experimental analysis was performed of a diffusion absorption refrigeration system (DARS) used alternative energy sources such as solar, liquid petroleum gas (LPG) sources. Two basic DAR cycles were set up and investigated: i) In the first cycle (DARS-1), the condensate is sub-cooled prior to the evaporator entrance by the coupled evaporator/gas heat exchanger similar with manufactured by Electrolux Sweden. ii) In the second cycle (DARS-2), the condensate is not sub-cooled prior to the evaporator entrance and gas heat exchanger is separated from the evaporator. (author)

  1. Open-ended response theory with polarizable embedding: multiphoton absorption in biomolecular systems.

    Science.gov (United States)

    Steindal, Arnfinn Hykkerud; Beerepoot, Maarten T P; Ringholm, Magnus; List, Nanna Holmgaard; Ruud, Kenneth; Kongsted, Jacob; Olsen, Jógvan Magnus Haugaard

    2016-10-12

    We present the theory and implementation of an open-ended framework for electric response properties at the level of Hartree-Fock and Kohn-Sham density functional theory that includes effects from the molecular environment modeled by the polarizable embedding (PE) model. With this new state-of-the-art multiscale functionality, electric response properties to any order can be calculated for molecules embedded in polarizable atomistic molecular environments ranging from solvents to complex heterogeneous macromolecules such as proteins. In addition, environmental effects on multiphoton absorption (MPA) properties can be studied by evaluating single residues of the response functions. The PE approach includes mutual polarization effects between the quantum and classical parts of the system through induced dipoles that are determined self-consistently with respect to the electronic density. The applicability of our approach is demonstrated by calculating MPA strengths up to four-photon absorption for the green fluorescent protein. We show how the size of the quantum region, as well as the treatment of the border between the quantum and classical regions, is crucial in order to obtain reliable MPA predictions.

  2. Tri-generation System based on Municipal Waste Gasification, Fuel Cell and an Absorption Chiller

    Directory of Open Access Journals (Sweden)

    Giannis Katsaros

    2018-03-01

    Full Text Available The present work focuses on the design of a novel tri-generation system based on gasification of municipal solid wastes, a solid oxide fuel cell and an ammonia-water absorption chiller. Tri-generation systems can be implemented in buildings such as hospitals and hotels, where there is a continuous and large demand for electricity, heating and cooling. The system is modelled in Aspen Plus and the influence of different operating parameters on the system performance was studied. The findings suggest that low air equivalent ratios and high gasification temperatures enhance the overall system performance. Syngas cleaning with metal sorbents zinc oxide and sodium bicarbonate for the removal of hydrogen sulfide and hydrogen chloride concentrations proved to be very effective, reducing the concentration of contaminants to < 1 ppm (part per million levels. The possibility of covering the demand profiles of a specific building was also investigated: the system could fully meet the electricity and cooling demands, whereas the heat requirements could be satisfied only up to 55%. Moreover, assuming 20 years of operation, the payback period was 4.5 years and the net present value exceeded 5 million euros.

  3. Experimental investigation on charging and discharging performance of absorption thermal energy storage system

    International Nuclear Information System (INIS)

    Zhang, Xiaoling; Li, Minzhi; Shi, Wenxing; Wang, Baolong; Li, Xianting

    2014-01-01

    Highlights: • A prototype of ATES using LiBr/H 2 O was designed and built. • Charging and discharging performances of ATES system were investigated. • ESE and ESD for cooling, domestic hot water and heating were obtained. - Abstract: Because of high thermal storage density and little heat loss, absorption thermal energy storage (ATES) is known as a potential thermal energy storage (TES) technology. To investigate the performance of the ATES system with LiBr–H 2 O, a prototype with 10 kW h cooling storage capacity was designed and built. The experiments demonstrated that charging and discharging processes are successful in producing 7 °C chilled water, 65 °C domestic hot water, or 43 °C heating water to meet the user’s requirements. Characteristics such as temperature, concentration and power variation of the ATES system during charging and discharging processes were investigated. The performance of the ATES system for supplying cooling, heating or domestic hot water was analyzed and compared. The results indicate that the energy storage efficiencies (ESE) for cooling, domestic hot water and heating are 0.51, 0.97, 1.03, respectively, and the energy storage densities (ESD) for cooling, domestic hot water and heating reach 42, 88, 110 kW h/m 3 , respectively. The performance is better than those of previous TES systems, which proves that the ATES system using LiBr–H 2 O may be a good option for thermal energy storage

  4. Safety, tolerability, and systemic absorption of dapivirine vaginal microbicide gel in healthy, HIV-negative women.

    Science.gov (United States)

    Nel, Annalene M; Coplan, Paul; van de Wijgert, Janneke H; Kapiga, Saidi H; von Mollendorf, Claire; Geubbels, Eveline; Vyankandondera, Joseph; Rees, Helen V; Masenga, Gileard; Kiwelu, Ireen; Moyes, Jocelyn; Smythe, Shanique C

    2009-07-31

    To assess the local and systemic safety of dapivirine vaginal gel vs. placebo gel as well as the systemic absorption of dapivirine in healthy, HIV-negative women. Two prospective, randomized, double-blind, placebo-controlled phase I/II studies were conducted at five research centers, four in Africa and one in Belgium. A total of 119 women used dapivirine gel (concentrations of 0.001, 0.002, 0.005, or 0.02%), and 28 used placebo gel twice daily for 42 days. The primary endpoints were colposcopic findings, adverse events, Division of AIDS grade 3 or grade 4 laboratory values, and plasma levels of dapivirine. Safety data were similar for the dapivirine and placebo gels. None of the adverse events with incidence more than 5% occurred with greater frequency in the dapivirine than placebo groups. Similar percentages of placebo and dapivirine gel users had adverse events that were considered by the investigator to be related to study gel. A total of five serious adverse events occurred in the two studies, and none was assessed as related to study gel. Mean plasma concentrations of dapivirine were approximately dose proportional, and, within each dose group, mean concentrations were similar on days 7, 28, and 42. The maximum observed mean concentration was 474 pg/ml in the 0.02% gel group on day 28. Two weeks after the final application of study gel, mean concentrations decreased to 5 pg/ml or less. Twice daily administration of dapivirine vaginal gel for 42 days was safe and well tolerated with low systemic absorption in healthy, HIV-negative women suggesting that continued development is warranted.

  5. Detection of an apparent, distant cluster of galaxies associated with the radio-tail QSO 3C 275.1

    International Nuclear Information System (INIS)

    Hintzen, P.; Boeshaar, G.O.; Scott, J.S.

    1981-01-01

    Based on the suggestion that QSOs with distorted radio structures are likely to be members of clusters of galaxies (Hintzen and Scott), we have obtained deep direct observations of the fields containing 3C 270.1 and 3C 275.1, the most reliably substantiated cases of wide-angle radio tails associated with QSOs. Our 75'' square field centered on 3C 275.1 (z = 0.557) contains over three-dozen objects, many of which are nonstellar, between m/sub R/ = 19.8 and m/sub R/ = 23.5. The quasar itself lies at the center of an illiptical nebulosity. The size of this nebulosity and the magnitude distribution of the surrounding objects are consistent with the interpretation that the QSO is the nucleus of a giant elliptical galaxy which is a member of a cluster of galaxies at zapprox.0.55. Our observations of 3C 270.1 (z = 1.519) show no definitive evidence of an associated cluster of galaxies, which is consistent with the cosmological interpretation of QSO redshifts

  6. Second law-based thermodynamic analysis of water-lithium bromide absorption refrigeration system

    Energy Technology Data Exchange (ETDEWEB)

    Kilic, Muhsin [Department of Mechanical Engineering, Faculty of Engineering and Architecture, Uludag University, TR 16059, Bursa (Turkey)]. E-mail: mkilic@uludag.edu.tr; Kaynakli, Omer [Department of Mechanical Engineering, Faculty of Engineering and Architecture, Uludag University, TR 16059, Bursa (Turkey)

    2007-08-15

    In this study, the first and the second law of thermodynamics are used to analyze the performance of a single-stage water-lithium bromide absorption refrigeration system (ARS) when some working parameters are varied. A mathematical model based on the exergy method is introduced to evaluate the system performance, exergy loss of each component and total exergy loss of all the system components. Parameters connected with performance of the cycle-circulation ratio (CR), coefficient of performance (COP), Carnot coefficient of performance (COP{sub c} ), exergetic efficiency ({xi}) and efficiency ratio ({tau})-are calculated from the thermodynamic properties of the working fluids at various operating conditions. Using the developed model, the effect of main system temperatures on the performance parameters of the system, irreversibilities in the thermal process and non-dimensional exergy loss of each component are analyzed in detail. The results show that the performance of the ARS increases with increasing generator and evaporator temperatures, but decreases with increasing condenser and absorber temperatures. Exergy losses in the expansion valves, pump and heat exchangers, especially refrigerant heat exchanger, are small compared to other components. The highest exergy loss occurs in the generator regardless of operating conditions, which therefore makes the generator the most important component of the cycle.

  7. Second law-based thermodynamic analysis of water-lithium bromide absorption refrigeration system

    International Nuclear Information System (INIS)

    Kilic, Muhsin; Kaynakli, Omer

    2007-01-01

    In this study, the first and the second law of thermodynamics are used to analyze the performance of a single-stage water-lithium bromide absorption refrigeration system (ARS) when some working parameters are varied. A mathematical model based on the exergy method is introduced to evaluate the system performance, exergy loss of each component and total exergy loss of all the system components. Parameters connected with performance of the cycle-circulation ratio (CR), coefficient of performance (COP), Carnot coefficient of performance (COP c ), exergetic efficiency (ξ) and efficiency ratio (τ)-are calculated from the thermodynamic properties of the working fluids at various operating conditions. Using the developed model, the effect of main system temperatures on the performance parameters of the system, irreversibilities in the thermal process and non-dimensional exergy loss of each component are analyzed in detail. The results show that the performance of the ARS increases with increasing generator and evaporator temperatures, but decreases with increasing condenser and absorber temperatures. Exergy losses in the expansion valves, pump and heat exchangers, especially refrigerant heat exchanger, are small compared to other components. The highest exergy loss occurs in the generator regardless of operating conditions, which therefore makes the generator the most important component of the cycle

  8. Theoretical study on the effect of operating conditions on performance of absorption refrigeration system

    Energy Technology Data Exchange (ETDEWEB)

    Kaynakli, Omer; Kilic, Muhsin [Uludag University, Faculty of Engineering and Architecture, Department of Mechanical Engineering, TR-16059, Bursa (Turkey)

    2007-02-15

    In this study, a detailed thermodynamic analysis of the water/lithium bromide absorption refrigeration cycle is performed. The influences of operating temperature and effectiveness of heat exchanger on the thermal loads of components, coefficients of performance (COP{sub c}, COP) and efficiency ratio ({eta}) are investigated. It is concluded that the COP{sub c} and COP values increase with increasing generator and evaporator temperatures but decrease with increasing condenser and absorber temperatures. The {eta} value varies with these temperatures. Also, the effects of solution and refrigerant heat exchangers on the performance, efficiency ratio of the system and fluid temperatures are compared. As a result, it is found that the solution heat exchanger (SHE) has more effect on the investigated parameters than the refrigerant heat exchanger (RHE). While the SHE increases the COP value up to a maximum 44%, the RHE has an effect of only 2.8%. (author)

  9. Diode laser absorption spectroscopy for process control: Sensor system design methodology

    International Nuclear Information System (INIS)

    Berzins, L.V.; Anklam, T.M.; Chambers, F.; Galanti, S.; Haynam, C.A.; Worden, E.F.

    1995-03-01

    A laser absorption spectroscopy (LAS) system has been developed at Lawrence Livermore National Laboratory (LLNL) for process control. LAS has proven itself to be an accurate and reliable method to monitor both density and composition. In this paper the important features and components of an industrial LAS diagnostic are described. Application of this approach to vaporization processes requires careful selection of the species and transitions to be monitored The relative vapor pressure, hyperfine structure, isotopic frequency shifts, and electronic temperature all effect the selection of a particular transition. In this paper we describe the methodology for choosing the optimal transition or transitions. Coevaporation of a titanium-niobium alloy is used to illustrate the methodology. In a related paper, T.M. Anklam et al describe the application of this diagnostic to monitoring and controlling composition in a physical vapor deposition process of industrial interest

  10. Study of laser radar system using the differential absorption method for detection of air pollutants

    Energy Technology Data Exchange (ETDEWEB)

    Inomata, H; Igarashi, T

    1975-11-01

    A laser radar system using the differential absorption method for remote measurement of atmospheric NO/sub 2/ and SO/sub 2/ is studied. A simultaneous two-wavelength dye laser for the transmitter and a simultaneous two-wavelength signal processer for the receiver are developed. In using this technique, one laser shot allows the determination of NO/sub 2/ concentrations with an uncertainty equivalent to 44 ppM times the range interval (in meters). It seems that the technique is most promising for a range-resolved measurement of ambient molecular pollutants, since it has the advantage of canceling the effect of atmospheric variation in a measurement when atmospheric aerosols are used as a distributed reflector.

  11. Comparative study of irreversibilities in an aqua-ammonia absorption refrigeration system

    Energy Technology Data Exchange (ETDEWEB)

    Ataer, O E [Gazi Univ., Ankara (TR). Mechanical Engineering Dept.; Gogus, Y [Middle East Technical Univ., Ankara (Turkey)

    1991-03-01

    Irreversibilities in components of an aqua-ammonia absorption refrigeration system (ARS) have been determined by second law analysis. The components of the ARS are as follows: condenser, evaporator, absorber, generator, pump, expansion valves, mixture heat exchanger and refrigerant heat exchanger. It is assumed that the ammonia concentration at the generator exit is, independent of the other parameters, equal to 0.999 and at the evaporator exit the gas is saturated vapour. Pressure losses between the generator and condenser, and the evaporator and absorber are taken into consideration. In the results the dimensionless exergy loss of each component, the exergetic coefficient of performance, the coefficient of performance and the circulation ratio are given graphically for each different generator, evaporator, condenser and absorber temperature. (author).

  12. Quasar 2175 Å dust absorbers - II. Correlation analysis and relationship with other absorption line systems

    Science.gov (United States)

    Ma, Jingzhe; Ge, Jian; Prochaska, J. Xavier; Zhang, Shaohua; Ji, Tuo; Zhao, Yinan; Zhou, Hongyan; Lu, Honglin; Schneider, Donald P.

    2018-03-01

    We present the cold neutral content (H I and C I gas) of 13 quasar 2175 Å dust absorbers (2DAs) at z = 1.6-2.5 to investigate the correlation between the presence of the UV extinction bump with other physical characteristics. These 2DAs were initially selected from the Sloan Digital Sky Surveys I-III and followed up with the Keck-II telescope and the Multiple Mirror Telescope as detailed in our Paper I. We perform a correlation analysis between metallicity, redshift, depletion level, velocity width, and explore relationships between 2DAs and other absorption line systems. The 2DAs on average have higher metallicity, higher depletion levels, and larger velocity widths than Damped Lyman α absorbers (DLAs) or subDLAs. The correlation between [Zn/H] and [Fe/Zn] or [Zn/H] and logΔV90 can be used as alternative stellar mass estimators based on the well-established mass-metallicity relation. The estimated stellar masses of the 2DAs in this sample are in the range of ˜109 to ˜2 × 1011 M⊙ with a median value of ˜2 × 1010 M⊙. The relationship with other quasar absorption line systems can be described as (1) 2DAs are a subset of Mg II and Fe II absorbers, (2) 2DAs are preferentially metal-strong DLAs/subDLAs, (3) More importantly, all of the 2DAs show C I detections with logN(C I) > 14.0 cm-2, and (4) 2DAs can be used as molecular gas tracers. Their host galaxies are likely to be chemically enriched, evolved, massive (more massive than typical DLA/subDLA galaxies), and presumably star-forming galaxies.

  13. MODERATE C IV ABSORBER SYSTEMS REQUIRE 1012 M☉ DARK MATTER HALOS AT z ∼ 2.3: A CROSS-CORRELATION STUDY OF C IV ABSORBER SYSTEMS AND QUASARS IN SDSS-III BOSS DR9

    International Nuclear Information System (INIS)

    Vikas, Shailendra; Wood-Vasey, W. Michael; Lundgren, Britt; Ross, Nicholas P.; Myers, Adam D.; AlSayyad, Yusra; York, Donald G.; Schneider, Donald P.; Brinkmann, J.; Bizyaev, Dmitry; Brewington, Howard; Malanushenko, Elena; Malanushenko, Viktor; Oravetz, Daniel; Pan, Kaike; Snedden, Stephanie; Ge, Jian; Muna, Demitri; Pâris, Isabelle; Petitjean, Patrick

    2013-01-01

    We measure the two-point cross-correlation function of C IV absorber systems and quasars, using spectroscopic data from the Sloan Digital Sky Survey III Baryon Oscillation Spectroscopic Survey (BOSS; Data Release 9). The 19,701 quasars and 6149 C IV ''moderate'' absorbers, 0.28 Å 2 and represent a factor of two increase in sample size over previous investigations. We find a correlation scale length and slope of the redshift-space cross-correlation function of s 0 = 8.46 ± 1.24 Mpc, γ = 1.68 ± 0.19, in the redshift-space range 10 0 = 7.76 ± 2.80 Mpc, γ = 1.74 ± 0.21. We measure the combined quasar and C IV bias to be b QSO b C I V = 8.81 ± 2.28. Using an estimate of b QSO from the quasar auto-correlation function we find b CIV = 2.38 ± 0.62. This b CIV implies that EW > 0.28 Å C IV absorbers at z ∼ 2.3 are typically found in dark matter halos that have masses ≥10 11.3 -10 13.4 M ☉ at that redshift. The complete BOSS sample will triple the number of both quasars and absorption systems and increase the power of this cross-correlation measurement by a factor of two.

  14. Ab-initio calculations of the hydrogen-uranium system: Surface phenomena, absorption, transport and trapping

    International Nuclear Information System (INIS)

    Taylor, Christopher D.; Scott Lillard, R.

    2009-01-01

    Density functional theory was applied to the initial steps of uranium hydriding: surface phenomena, absorption, bulk transport and trapping. H adsorbs exothermically to the (0 0 1) surface, yet H absorption into the bulk is endothermic, with off-center octahedral absorption having the lowest absorption energy of 0.39 eV, relative to molecular H 2 . H absorption in interstitial sites causes a local softening of the bulk modulus. Diffusion of H in unstrained α-U has a barrier of 0.6 eV. The energy of H absorption adjacent to the chemical impurities C, S, Si was lowered by an amount proportional to the size of the impurity atom, and the resulting lattice strain Si > S > C. Thus, impurities may promote hydriding by providing surfaces or prestrained zones for H uptake.

  15. Solar-assisted absorption air-conditioning systems in buildings: Control strategies and operational modes

    International Nuclear Information System (INIS)

    Shirazi, Ali; Pintaldi, Sergio; White, Stephen D.; Morrison, Graham L.; Rosengarten, Gary; Taylor, Robert A.

    2016-01-01

    Highlights: • A simulation model of a solar driven absorption chiller is developed in detail. • Three control strategies were proposed in the solar loop of the plant. • Series and parallel auxiliary heater arrangements were investigated. • The results showed the auxiliary-heater in parallel outperformed the series one. • Solar fraction can be increased by 20% by implementing the proposed configuration. - Abstract: Solar-assisted cooling technology has enormous potential for air-conditioning applications since both solar energy supply and cooling energy demand are well correlated. Unfortunately, market uptake of solar cooling technologies has been slow due to the high capital cost and limited design/operational experience. In the present work, different designs and operational modes for solar heating and cooling (SHC) absorption chiller systems are investigated and compared in order to identify the preferred design strategies for these systems. Three control scenarios are proposed for the solar collector loop. The first uses a constant flow pump, while the second and third control schemes employ a variable speed pump, where the solar collector (SC) set-point temperature could be either fixed or adjusted to the required demand. Series and parallel arrangements, between the auxiliary heater and the storage tank, have been examined in detail from an energy efficiency perspective. A simulation model for different system layouts is developed in the transient system simulation environment (TRNSYS, Version 17). Simulation results revealed that the total solar fraction of the plant is increased by up to 11% when a variable speed solar loop pump is used to achieve a collector set-point temperature adjusted according to the building load demand. Another significant finding of this study is that a parallel configuration for the auxiliary heater out-performs a conventional series configuration. The yearly performance of an auxiliary heater in parallel with the storage

  16. Cardiovascular safety of the oral controlled absorption system (OCAS) formulation of tamsulosin compared to the modified release (MR) formulation

    NARCIS (Netherlands)

    Michel, M. C.; Korstanje, C.; Klauwinkel, W.; Shear, M.; Davies, J.; Quartel, A.

    2005-01-01

    Objective: The potential to interfere with efferent adrenergic drive in the cardiovascular system was tested in elderly healthy subjects for the new oral controlled absorption system (OCAS) 0.4 mg tablet formulation of tamsulosin compared to the modified release (MR) 0.4 mg capsule formulation of

  17. X-ray absorption spectroscopy in biological systems. Opportunities and limitations

    Energy Technology Data Exchange (ETDEWEB)

    Bovenkamp, Gudrun Lisa

    2013-05-15

    X-ray absorption spectroscopy has become more important for applications in the material sciences, geology, environmental science and biology, specifically in the field of molecular biology. The scope of this thesis is to add more experimental evidence in order to show how applicable X-ray absorption near edge structure (XANES) is to biology. Two biological systems were investigated, at the molecular level, lead uptake in plants and the effect of silver on bacteria. This investigation also included an analysis of the sensitivity of Pb L{sub 3}- and Ag L{sub 3}-XANES spectra with regard to their chemical environment. It was shown that Pb L{sub 3}- and Ag L{sub 3}-XANES spectra are sensitive to an environment with at least differences in the second coordination shell. The non-destructive and element specific properties of XANES are the key advantages that were very important for this investigation. However, in both projects the adequate selection of reference compounds, which required in some cases a chemical synthesis, was the critical factor to determine the chemical speciation and, finally, possible uptake and storage mechanisms for plants and antibacterial mechanisms of silver. The chemical environment of Pb in roots and leaves of plants from four different plant families and a lichen from a former lead mining site in the Eifel mountains in Germany was determined using both solid compounds and aqueous solutions of different ionic strength, which simulate the plant environment. The results can be interpreted in such a way that lead is sorbed on the surface of cell walls. Silver bonding as reaction with Staphylococcus aureus, Listeria monocytogenes, and Escherichia coli bacteria was determined using inorganic silver compounds and synthesized silver amino acids. Silver binds to sulfur, amine and carboxyl groups in amino acids.

  18. X-ray absorption spectroscopy in biological systems. Opportunities and limitations

    International Nuclear Information System (INIS)

    Bovenkamp, Gudrun Lisa

    2013-05-01

    X-ray absorption spectroscopy has become more important for applications in the material sciences, geology, environmental science and biology, specifically in the field of molecular biology. The scope of this thesis is to add more experimental evidence in order to show how applicable X-ray absorption near edge structure (XANES) is to biology. Two biological systems were investigated, at the molecular level, lead uptake in plants and the effect of silver on bacteria. This investigation also included an analysis of the sensitivity of Pb L 3 - and Ag L 3 -XANES spectra with regard to their chemical environment. It was shown that Pb L 3 - and Ag L 3 -XANES spectra are sensitive to an environment with at least differences in the second coordination shell. The non-destructive and element specific properties of XANES are the key advantages that were very important for this investigation. However, in both projects the adequate selection of reference compounds, which required in some cases a chemical synthesis, was the critical factor to determine the chemical speciation and, finally, possible uptake and storage mechanisms for plants and antibacterial mechanisms of silver. The chemical environment of Pb in roots and leaves of plants from four different plant families and a lichen from a former lead mining site in the Eifel mountains in Germany was determined using both solid compounds and aqueous solutions of different ionic strength, which simulate the plant environment. The results can be interpreted in such a way that lead is sorbed on the surface of cell walls. Silver bonding as reaction with Staphylococcus aureus, Listeria monocytogenes, and Escherichia coli bacteria was determined using inorganic silver compounds and synthesized silver amino acids. Silver binds to sulfur, amine and carboxyl groups in amino acids.

  19. Advanced Sine Wave Modulation of Continuous Wave Laser System for Atmospheric CO2 Differential Absorption Measurements

    Science.gov (United States)

    Campbell, Joel F.; Lin, Bing; Nehrir, Amin R.

    2014-01-01

    NASA Langley Research Center in collaboration with ITT Exelis have been experimenting with Continuous Wave (CW) laser absorption spectrometer (LAS) as a means of performing atmospheric CO2 column measurements from space to support the Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) mission.Because range resolving Intensity Modulated (IM) CW lidar techniques presented here rely on matched filter correlations, autocorrelation properties without side lobes or other artifacts are highly desirable since the autocorrelation function is critical for the measurements of lidar return powers, laser path lengths, and CO2 column amounts. In this paper modulation techniques are investigated that improve autocorrelation properties. The modulation techniques investigated in this paper include sine waves modulated by maximum length (ML) sequences in various hardware configurations. A CW lidar system using sine waves modulated by ML pseudo random noise codes is described, which uses a time shifting approach to separate channels and make multiple, simultaneous online/offline differential absorption measurements. Unlike the pure ML sequence, this technique is useful in hardware that is band pass filtered as the IM sine wave carrier shifts the main power band. Both amplitude and Phase Shift Keying (PSK) modulated IM carriers are investigated that exibit perfect autocorrelation properties down to one cycle per code bit. In addition, a method is presented to bandwidth limit the ML sequence based on a Gaussian filter implemented in terms of Jacobi theta functions that does not seriously degrade the resolution or introduce side lobes as a means of reducing aliasing and IM carrier bandwidth.

  20. Experimental study on a project with CHP system basing on absorption cycles

    International Nuclear Information System (INIS)

    Sun, Jian; Fu, Lin; Sun, Fangtian; Zhang, Shigang

    2014-01-01

    A new heat recovery system for the CHP (combined heating and power) is presented, and HRU (heat recovery unit) and AHE (absorption heat exchanger) are invented to improve the total energy efficiency of the conventional CHP system by more than 20%, which are installed at the thermal power plant and the heating substation separately. The HRU could recover the low grade heat of exhausted steam from the turbine directly, and the AHE could decrease the temperature of back water of primary pipe to a lower temperature than that of secondary pipe without changing the flow rate of secondary pipe. A large demonstration project employing this technology has been built in Datong of China. And experimental results of HRU and AHE are presented to evaluate this system. - Highlights: • The total energy efficiency of CHP could by increased by more than 20%. • Temperature of back water of primary pipe could be lower than that of secondary pipe. • Heating capacity of primary pipe could be increased significantly. • Low grade heat of exhausted steam from turbine could be recovered directly

  1. Modelling the effect of oil/fat content in food systems on flavour absorption by LLDPE.

    NARCIS (Netherlands)

    Dekker, M.; Willige, van R.W.G.; Linssen, J.P.H.; Voragen, A.G.J.

    2003-01-01

    One of the phenomena in food packaging interactions is flavour absorption. Absorption of flavour compounds from food products into food-packaging materials can result in loss of flavour compounds or an unbalance in the flavour profile changing a product's quality. The food matrix influences the

  2. Evaluation of systemic absorption and renal effects of topical ophthalmic flurbiprofen and diclofenac in healthy cats.

    Science.gov (United States)

    Lanuza, Rick; Rankin, Amy J; KuKanich, Butch; Meekins, Jessica M

    2016-07-01

    To investigate systemic absorption and renal effects of topically applied ophthalmic flurbiprofen and diclofenac in healthy cats. Twelve domestic shorthair cats. Cats were randomly assigned to two treatment groups (n = 6) and administered one drop (approximately 40 μL) of either flurbiprofen 0.03% or diclofenac 0.1% in both eyes four times daily (6 am, 12 pm, 6 pm, and 12 am) for 14 days. Blood samples were collected on days 0, 4, 8, 14, 16, and 17 and analyzed by liquid chromatography and mass spectrometry for flurbiprofen and diclofenac plasma concentrations. A complete blood count (CBC), serum chemistry, and urinalysis were analyzed at the beginning of the study (Day 0) and at the end of topical drug administration (Day 15). Both drugs demonstrated systemic absorption. Flurbiprofen was detected (mean ± SD) at day 4 (237 ± 65 ng/mL), day 8 (396 ± 91 ng/mL), day 14 (423 ± 56 ng/mL), day 16 (350 ± 66 ng/mL), and day 17 (270 ± 62 ng/mL), and diclofenac was detected (mean ± SD) at day 4 (130 ± 44 ng/mL), day 8 (131 ± 25 ng/mL), day 14 (150 ± 36 ng/mL), and sporadically on day 16 [corrected]. Flurbiprofen plasma concentration decreased slowly over 48 h after the last dose. No clinically significant abnormalities were noted in the serum blood urea nitrogen, creatinine, or urine specific gravity at the end of topical drug administration compared to the beginning of the study. Flurbiprofen and diclofenac were systemically absorbed after topical administration four times daily to both eyes of healthy cats. Flurbiprofen reached higher plasma concentrations compared to diclofenac. © 2015 American College of Veterinary Ophthalmologists.

  3. SODIUM ABSORPTION SYSTEMS TOWARD SN Ia 2014J ORIGINATE ON INTERSTELLAR SCALES

    Energy Technology Data Exchange (ETDEWEB)

    Maeda, K.; Nogami, D. [Department of Astronomy, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto 606-8502 (Japan); Tajitsu, A. [Subaru Telescope, National Astronomical Observatory of Japan, 650 North A’ohoku Place, Hilo, HI 96720 (United States); Kawabata, K. S. [Hiroshima Astrophysical Science Center, Hiroshima University, Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Foley, R. J. [Astronomy Department, University of Illinois at Urbana-Champaign, 1002 W. Green Street, Urbana, IL 61801 (United States); Honda, S.; Arai, A. [Nishi-Harima Astronomical Observatory, Center for Astronomy, University of Hyogo, 407-2, Nishigaichi, Sayo-cho, Sayo, Hyogo 679-5313 (Japan); Moritani, Y.; Ishigaki, M.; Nomoto, K.; Schramm, M. [Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8583 (Japan); Tanaka, M.; Aoki, W. [National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588 (Japan); Hashimoto, O. [Gunma Astronomical Observatory, Takayama, Gunma 377-0702 (Japan); Simon, J. D. [Observatories of the Carnegie Institution for Science, 813 Santa Barbara St, Pasadena, CA 91101 (United States); Phillips, M. M. [Carnegie Observatories, Las Campanas Observatory, Casilla 601, La Serena (Chile); Yamanaka, M. [Department of Physics, Faculty of Science and Engineering, Konan University, Okamoto, Kobe, Hyogo 658-8501 (Japan); Milisavljevic, D.; Soderberg, A. M. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Mazzali, P. A., E-mail: keiichi.maeda@kusastro.kyoto-u.ac.jp [Astrophysics Research Institute, Liverpool John Moores University, Liverpool L3 5RF (United Kingdom); and others

    2016-01-10

    Na i D absorbing systems toward Type Ia supernovae (SNe Ia) have been intensively studied over the last decade with the aim of finding circumstellar material (CSM), which is an indirect probe of the progenitor system. However, it is difficult to deconvolve CSM components from non-variable, and often dominant, components created by interstellar material (ISM). We present a series of high-resolution spectra of SN Ia 2014J from before maximum brightness to ≳250 days after maximum brightness. The late-time spectrum provides unique information for determining the origin of the Na i D absorption systems. The deep late-time observation allows us to probe the environment around the SN at a large scale, extending to ≳40 pc. We find that a spectrum of diffuse light in the vicinity, but not directly in the line of sight, of the SN has absorbing systems nearly identical to those obtained for the “pure” SN line of sight. Therefore, basically all Na i D systems seen toward SN 2014J must originate from foreground material that extends to at least ∼40 pc in projection and none at the CSM scale. A fluctuation in the column densities at a scale of ∼20 pc is also identified. After subtracting the diffuse, “background” spectrum, the late-time Na i D profile along the SN line of sight is consistent with profiles near maximum brightness. The lack of variability on a ∼1 year timescale is consistent with the ISM interpretation for the gas.

  4. Determination of mercury by multisyringe flow injection system with cold-vapor atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Leal, L.O.; Elsholz, O.; Forteza, R.; Cerda, V.

    2006-01-01

    A new software-controlled time-based multisyringe flow injection system for mercury determination by cold-vapor atomic absorption spectrometry is proposed. Precise known volumes of sample, reducing agent (1.1% SnCl 2 in 3% HCl) and carrier (3% HCl) are dispensed into a gas-liquid separation cell with a multisyringe burette coupled with one three-way solenoid valve. An argon flow delivers the reduced mercury to the spectrometer. The optimization of the system was carried out testing reaction coils and gas-liquid separators of different design as well as changing parameters, such as sample and reagents volumes, reagent concentrations and carrier gas flow rate, among others. The analytical curves were obtained within the range 50-5000 ng L -1 . The detection limit (3σ b /S) achieved is 5 ng L -1 . The relative standard deviation (R.S.D.) was 1.4%, evaluated from 16 successive injections of 250 ng L -1 Hg standard solution. The injection and sample throughput per hour were 44 and 11, respectively. This technique was validated by means of solid and water reference materials with good agreement with the certified values and was successfully applied to fish samples

  5. Simulator for design absorption refrigeration system; Simulador para projeto de ciclos de refrigeracao por absorcao

    Energy Technology Data Exchange (ETDEWEB)

    Morejon, C.F.M.; Brum, N. de C. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Engenharia Mecanica]. E-mails: Camilo_freddy@hotmail.com; Nisio@serv.com.ufrj.br

    2000-07-01

    This work presents a development of a thermal fluid dynamics model and a solution of a steady state absorption refrigeration cycle, with ammonia water as the working fluid. Analytical thermodynamics models expressing the enthalpy in function of pressure, temperature and composition (h=f(P,T,x)), are used with the aim to design all of the cycle devices, moved by any type of energy such as solar, natural gas, steam or electrical energy (Morejon and Hackenberg, 1978). The development of the analysis is carried out by the application of thermal fluid dynamics concepts together with a detailed study of the heat and mass transfer in the different cycle stages. The thermodynamic cycle model, obtained from equation of state for ammonia - water mixtures (Ziegker and Trepp, 1984), is represented by the relation h - x (enthalpy-composition) for different pressures and temperatures. The obtained models are used to implement computational codes in MAPLE-V facilitating the design and simulation of refrigeration system. This study can be applied in the systems of air conditioning and refrigeration chambers design. (author)

  6. Thermodynamic analysis of an absorption refrigeration system with ionic-liquid/refrigerant mixture as a working fluid

    International Nuclear Information System (INIS)

    Kim, Yoon Jo; Kim, Sarah; Joshi, Yogendra K.; Fedorov, Andrei G.; Kohl, Paul A.

    2012-01-01

    Thermodynamics of an ionic-liquid (IL) based absorption refrigeration system has been numerically analyzed. It provides an alternative to the normally toxic working fluids, such as the ammonia in conventional absorption systems. The use of ILs also eliminates crystallization and metal-compatibility problems of the water/LiBr system. Mixtures of refrigerants and imidazolium-based ILs are theoretically explored as the working fluid pairs in a miniature absorption refrigeration system, so as to utilize waste-heat to power a refrigeration/heat pump system for electronics cooling. A non-random two-liquid (NRTL) model was built and used to predict the solubility of the mixtures. Saturation temperatures at the evaporator and condenser were set at 25 °C and 50 °C, respectively, with the power dissipation of 100 W. Water in combination with [emim][BF 4 ] (1-ethyl-3-methylimidazolium tetrafluoroborate) gave the highest coefficient of performance (COP) around 0.9. The refrigerant/IL compatibility indicated by the circulation ratio, alkyl chain length of the IL, and thermodynamic properties of the refrigerants, such as latent heat of evaporation were proven to be important factors in determining the performance of the absorption system. The negative effect of high viscosity was mitigated by dilution of the IL with the refrigerant and the use of slightly larger microfluidic channel heat exchangers. -- Highlights: ► Mixtures of refrigerant/ionic-liquid are studied for absorption system. ► We carry out comprehensive theoretical thermodynamic analysis. ► The essential factors of refrigerant/IL affecting the performance are identified. ► Water/[emim][BF 4 ] showed the best performance of COP. ► The effects of high viscosity ILs on the system performance are not significant.

  7. New waste heat district heating system with combined heat and power based on absorption heat exchange cycle in China

    International Nuclear Information System (INIS)

    Sun Fangtian; Fu Lin; Zhang Shigang; Sun Jian

    2012-01-01

    A new waste heat district heating system with combined heat and power based on absorption heat exchange cycle (DHAC) was developed to increase the heating capacity of combined heat and power (CHP) through waste heat recovery, and enhance heat transmission capacity of the existing primary side district heating network through decreasing return water temperature by new type absorption heat exchanger (AHE). The DHAC system and a conventional district heating system based on CHP (CDH) were analyzed in terms of both thermodynamics and economics. Compared to CDH, the DHAC increased heating capacity by 31% and increased heat transmission capacity of the existing primary side district heating network by 75%. The results showed that the exergetic efficiency of DHAC was 10.41% higher and the product exergy monetary cost was 36.6¥/GJ less than a CHD. DHAC is an effective way to increase thermal utilization factor of CHP, and to reduce district heating cost. - Highlights: ► Absorption heat pumps are used to recover waste heat in CHP. ► Absorption heat exchanger can reduce exergy loss in the heat transfer process. ► New waste heat heating system (DHAC) can increase heating capacity of CHP by 31%. ► DHAC can enhance heat transmission capacity of the primary pipe network by 75%. ► DHAC system has the higher exergetic efficiency and the better economic benefit.

  8. The absorption and distribution of Cesium-134 in rice-soil system

    International Nuclear Information System (INIS)

    Xu Yinliang; Chen Chuanqun; Chen Bin; Sun Zhiming

    1991-01-01

    Dynamics of absorption of 134 Cs by rice shows that absorption rate is the fastest at boot stage; absorption capacities of 134 Cs in soils are different with the different physical-chemical properties of soils; absorption amounts vary with the time of irrigating 134 Cs; the closer the irrigation time to mature stage is, the more the absorption amount of 134 Cs in rice will be; the more the irrigating times are, and the higher the radioactivity of 134 Cs in irrigating water is, the more the absorption amount in rice will be. After brown rice is polished, contamination of 134 Cs can be decreased by 22.6-45.6%. The order of specific activity in rice is: bran > root > straw > husk > polished rice. Percentage activity of straw, brown rice, root and husk is 51.4%, 28.4%, 11.8% and 8.4% respectively. The migration of 134 Cs is very slow in soil and 95.1% of 134 Cs is concentrated in surface soil (0-2.5 cm). The distribution ratio of 134 Cs in the rice and soil is 6.1%:93.9%. Potassium ion can inhibit the absorption of 134 Cs by rice. There is an exponential function between the concentration of potassium ion and specific activity of 134 Cs in rice

  9. Materials and systems developments on solid absorption refrigeration with CaCl2·xNH3

    International Nuclear Information System (INIS)

    Iloeji, O.C.

    1995-10-01

    The paper presents some developments on the stabilization of CaCl 2 for use as a solid absorption material in refrigerators, the development of a refrigerator using the stabilized salt, and computer modelling of the refrigerator system. (author). 8 refs, 19 figs

  10. Comparison of vascular alpha(1)-adrenoceptor antagonism of tamsulosin in oral controlled absorption system (OCAS) and modified release (MR) formulations

    NARCIS (Netherlands)

    Michel, M. C.; Korstanje, C.; Krauwinkel, W.; Shear, M.; Davies, J.; Quartel, A.

    2005-01-01

    Objective: The cardiovascular a-l-adrenoceptor (AR) antagonism of the new oral controlled absorption system (OCAS) 0.4 mg tablet formulation of tamsulosin was compared with that of the modified release (MR) 0.4 mg capsule formulation in healthy male volunteers after a single dose in the fasted

  11. Comparison of the cardiovascular effects of tamsulosin oral controlled absorption system (OCAS) and alfuzosin prolonged release (XL)

    NARCIS (Netherlands)

    Michel, Martin C.; Chapple, Christopher R.

    2006-01-01

    OBJECTIVE: The cardiovascular (CV) effects of tamsulosin oral controlled absorption system (OCAS) 0.4 mg were compared with those of alfuzosin prolonged release (XL) 10 mg. METHODS: Two single-dose, crossover studies were performed. In study 1, CV alpha1-adrenoceptor antagonism was assessed by

  12. A comparison of neutron resonance absorption in thermal reactor lattices in the AUS neutronics code system with Monte Carlo calculations

    International Nuclear Information System (INIS)

    Robinson, G.S.

    1985-08-01

    The calculation of resonance shielding by the subgroup method, as incorporated in the MIRANDA module of the AUS neutronics code system, is compared with Monte Carlo calculatons for a number of thermal reactor lattices. For the large range of single rod and rod cluster lattices considered, AUS results for resonance absorption were high by up to two per cent

  13. Three-objective optimization of a novel triple-effect absorption heat transformer combined with a water desalination system

    International Nuclear Information System (INIS)

    Mahmoudi, S.M.S.; Salehi, S.; Yari, M.

    2017-01-01

    Highlights: • A new type of triple-effect absorption heat transformers is proposed. • A temperature lift of 180 °C is obtained by the proposed system. • The proposed system is observed to be the most effective. • The highest distilled water mass flow rate is obtained by the proposed system. - Abstract: A novel triple-effect absorption heat transformer is proposed and compared with a most studied configuration of triple-effect absorption heat transformer and a modified form of it from the viewpoint of exergoeconomics. All systems are integrated with water desalination system to produced distilled water. Sensitivity analyses are performed to identify the influence on the systems’ performance of such decision parameters as the temperatures of evaporator, condenser, absorber and absorbing evaporators for all the configurations. Then a three-objective optimization is accomplished to specify the optimal design points for the purpose of minimizing the product unit cost and maximizing the exergy coefficient of performance as well as the distilled water mass flow rate. In this regard, the Pareto frontiers are plotted for all the systems. The results show that, under the optimized conditions, the exergy coefficient of performance and distilled water mass flow rate for the proposed configuration can be higher by 16% and 38% with respect to the corresponding values in the other two systems. In addition, it is observed that the maximum gross temperature lift in the proposed system is about 20–40% higher than those in the other systems.

  14. Effluent Storage and Biomat Occurrence among Septic System Absorption Field Architectures in a Typic Fragiudult.

    Science.gov (United States)

    Prater, N J M; Brye, K R; Dunn, S; Soerens, T S; Sharpley, A N; Mason, E; Gbur, E E

    2013-07-01

    On-site wastewater treatment systems (OWTSs) are commonly used by households in areas of low population density to treat household wastewater and recycle it back to the environment. However, new absorption field products of differing architecture types have recently become available. A 3-yr field study was conducted in Bethel Heights, northwest Arkansas to assess several newer architecture types (i.e., chambers, polystyrene-aggregate, and gravel-less pipe) relative to the traditional pipe-and-gravel design under wet- and dry-soil conditions. Thirteen products of four different architecture types were installed in 46-cm-deep trenches in a Captina silt loam (fine-silty, siliceous, active, mesic Typic Fragiudult). Products were evaluated based on in-trench solution storage measured with an electronic water-level sensor approximately weekly from January 2009 through January 2012. Between May 2010 and January 2012, the thickness of any biomat formation was measured approximately weekly by insertion of a wooden dowel through in-trench monitoring ports. Architecture type alone did not affect ( > 0.05) in-trench solution storage. However, solution storage among individual products differed under wet- and dry-soil conditions ( storage but that several alternative products also had greater solution storage than that of the traditional pipe-and-gravel system. With no observed effluent surfacing, the soil morphology approach appears to be adequate and appropriately environmentally conservative for assigning typical single-family loading rates to alternative OWTS products and to the traditional pipe-and-gravel system. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  15. Synthesis of integrated absorption refrigeration systems involving economic and environmental objectives and quantifying social benefits

    International Nuclear Information System (INIS)

    Lira-Barragán, Luis Fernando; Ponce-Ortega, José María; Serna-González, Medardo; El-Halwagi, Mahmoud M.

    2013-01-01

    This paper presents a new methodology for energy integration of systems that require absorption refrigeration. It allows heat exchange among process hot and cold streams and the integration of excess process heat as well as external utilities provided by solar energy, fossil fuels and biofuels. An optimization formulation is developed to address the multiple objectives of simultaneously minimizing the total annualized cost and the greenhouse gas emissions while the social impact is measured by the number of jobs generated by the project in the entire life cycle. The economic function accounts for the tax credit obtained by the reduction of greenhouse gas emissions when cleaner technologies are used. The proposed model also considers the optimal selection of different types of solar collectors and the optimal time-based usage of solar energy, fossil fuel, and biofuel. Two example problems are presented to show the applicability of the proposed methodology. -- Highlights: ► An approach for the thermal integration of refrigeration processes is proposed. ► Different forms of sustainable energies are considered in the optimization process. ► Economic and environmental objectives are considered quantifying the number of jobs. ► The availability for the different forms of energy is taken into account. ► Results show significant advantages obtained with the proposed approach

  16. Hydrogeologic implications of increased septic-tank-soil-absorption system density, Ogden Valley, Weber County, Utah

    Science.gov (United States)

    Lowe, Mike; Miner, Michael L.; ,

    1990-01-01

    Ground water in Ogden Valley occurs in perched, confined, and unconfined aquifers in the valley fill to depths of 600 feet and more. The confined aquifer, which underlies only the western portion of the valley, is overlain by cleyey silt lacustrine sediments probably deposited during the Bonneville Basin's Little Valley lake cycle sometime between 90,000 and 150,000 years ago. The top of this cleyey silt confining layer is generally 25 to 60 feet below the ground surface. Unconfined conditions occur above and beyond the outer margin of the confining layer. The sediments overlying the confining layer are primarily Lake Bonneville deposits. Water samples from springs, streams, and wells around Pineview Reservoir, and from the reservoir itself, were collected and analyzed. These samples indicate that water quality in Ogden Valley is presently good. Average nitrate concentrations in the shallow unconfined aquifer increase toward the center of Ogden Valley. This trend was not observed in the confined aquifer. There is no evidence, however, of significant water-quality deterioration, even in the vicinity of Huntsville, a town that has been densely developed using septic-tank-soil-absorption systems for much of the time since it was founded in 1860.

  17. Resonant two-photon absorption and electromagnetically induced transparency in open ladder-type atomic system.

    Science.gov (United States)

    Moon, Han Seb; Noh, Heung-Ryoul

    2013-03-25

    We have experimentally and theoretically studied resonant two-photon absorption (TPA) and electromagnetically induced transparency (EIT) in the open ladder-type atomic system of the 5S(1/2) (F = 1)-5P(3/2) (F' = 0, 1, 2)-5D(5/2) (F″ = 1, 2, 3) transitions in (87)Rb atoms. As the coupling laser intensity was increased, the resonant TPA was transformed to EIT for the 5S(1/2) (F = 1)-5P(3/2) (F' = 2)-5D(5/2) (F″ = 3) transition. The transformation of resonant TPA into EIT was numerically calculated for various coupling laser intensities, considering all the degenerate magnetic sublevels of the 5S(1/2)-5P(3/2)-5D(5/2) transition. From the numerical results, the crossover from TPA to EIT could be understood by the decomposition of the spectrum into an EIT component owing to the pure two-photon coherence and a TPA component caused by the mixed term.

  18. Solar heating and cooling system with absorption chiller and low temperature latent heat storage: Energetic performance and operational experience

    Energy Technology Data Exchange (ETDEWEB)

    Helm, M.; Keil, C.; Hiebler, S.; Mehling, H.; Schweigler, C. [Bavarian Center for Applied Energy Research (ZAE Bayern) (Germany)

    2009-06-15

    Absorption cooling systems based on water/lithium bromide (LiBr) solution typically require an open wet cooling tower to transfer the reject heat to the ambient. Yet, water consumption, the need for water make-up and cleaning, formation of fog, and the risk of Legionella bacteria growth are hindering factors for the implementation of small solar cooling systems. The application of a latent heat storage supporting the heat rejection of the absorption chiller in conjunction with a dry cooling system allows eliminating the wet cooling tower. By that means heat rejection of the chiller is shifted to periods with lower ambient temperatures, i.e. night time or off-peak hours. The system concept and the hydraulic scheme together with an analysis of the energetic performance of the system are presented, followed by a report on the operation of a first pilot installation. (author)

  19. Application of a solar refrigeration system by absorption for the air conditioning of buildings

    Energy Technology Data Exchange (ETDEWEB)

    Machielsen, Cees H. M [Delft University of Technology, Mekelweg (Netherlands); Hagendijk, Andre E [Consultancy and Research (Netherlands)

    2000-07-01

    This paper describes the Sofri project, a cooperation between Ceeran Ltd and The Delft University of Technology. The main objective of this project is to develop the necessary knowledge and experience to commercialize solar-assisted air conditioning and dehumidification systems in the Dutch Caribbean. The project is motivated by the present needs of the Dutch Caribbean for renewable energy sources and the fact that the Caribbean has a high and uniform insolation throughout the year. Furthermore, hotels and offices in this area use more than 40% of their energy for air-conditioning purposes. Therefore solar-assisted air conditioning systems are a logic approach in reducing the energy demand and to lower the peak electricity reducing the energy demands for the local power station. Ceeran Ltd has the objective to reach full commercialization of the proposed technologies in the Dutch Caribbean. The research is concentrated on liquid absorption machines and solar collection systems such as flat plates with selective surfaces, heat pipe evacuated tubes flat plate collectors, and Compound Parabolic Concentrators. The first demonstration unit is planned to be installed in an office building in Curacao. The installation consists of a 35 kW LiBr/H{sub 2}O absorption machine driven by 100 m{sup 2} flat pate collectors with a gas backup system. The system will provide comfort air-conditioning for this these type of office buildings during daytime. [Spanish] Este documento describe el proyecto SOFRI, una cooperacion entre Ceeran, Ltd, y la Universidad Tecnologica del Delft. El principal objetivo de este proyecto es el de desarrollar el conocimiento necesario y la experiencia para comercializar los sistemas de aire acondicionado y deshumidificacion ayudados por la energia solar en el Caribe Holandes. Este proyecto ha sido motivado por las actuales necesidades del Caribe Holandes de fuentes de energia renovable y por el hecho de que el Caribe tiene una alta y uniforme insolacion

  20. Evaluation of an oral carrier system in rats: bioavailability and gastrointestinal absorption properties of curcumin encapsulated PBCA nanoparticles

    International Nuclear Information System (INIS)

    Sun Min; Zhao Lixia; Guo Chenyu; Cao Fengliang; Chen Huanlei; Zhao Liyan; Tan Qi; Zhu Xiuqing; Zhu Fanping; Ding Tingting; Zhai Yingjie; Zhai Guangxi

    2012-01-01

    A new oral delivery system, polybutylcyanoacrylate nanoparticles (PBCNs), was introduced to improve the oral bioavailability of curcumin (CUR), a poorly soluble drug. The formulation was optimized by orthogonal design and the optimal PBCNs loading CUR exhibited a spherical shape under transmission electron microscopy with a range of 40–400 nm. Physicochemical state of CUR in PBCN was investigated by X-ray diffraction and the possible structure changes occurring in CUR after conjugating with polybutylcyanoacrylate were studied with FTIR. The results indicated that CUR in PBCN was in a non-crystalline state and CUR was encapsulated in PBCN without chemical reaction. The oral pharmacokinetic study was conducted in rats and the relative bioavailability of CUR encapsulated PBCNs to the crude CUR was more than 800%. The in situ absorption experiment in rat intestine indicated the absorption was first order with passive diffusion mechanism. The absorption results in various segments of intestine showed that the main absorption sites were ileum and colon. It can be concluded that PBCNs as an oral carrier can significantly improve the oral absorption of a poorly soluble drug.

  1. Evaluation of an oral carrier system in rats: bioavailability and gastrointestinal absorption properties of curcumin encapsulated PBCA nanoparticles

    Science.gov (United States)

    Sun, Min; Zhao, Lixia; Guo, Chenyu; Cao, Fengliang; Chen, Huanlei; Zhao, Liyan; Tan, Qi; Zhu, Xiuqing; Zhu, Fanping; Ding, Tingting; Zhai, Yingjie; Zhai, Guangxi

    2012-02-01

    A new oral delivery system, polybutylcyanoacrylate nanoparticles (PBCNs), was introduced to improve the oral bioavailability of curcumin (CUR), a poorly soluble drug. The formulation was optimized by orthogonal design and the optimal PBCNs loading CUR exhibited a spherical shape under transmission electron microscopy with a range of 40-400 nm. Physicochemical state of CUR in PBCN was investigated by X-ray diffraction and the possible structure changes occurring in CUR after conjugating with polybutylcyanoacrylate were studied with FTIR. The results indicated that CUR in PBCN was in a non-crystalline state and CUR was encapsulated in PBCN without chemical reaction. The oral pharmacokinetic study was conducted in rats and the relative bioavailability of CUR encapsulated PBCNs to the crude CUR was more than 800%. The in situ absorption experiment in rat intestine indicated the absorption was first order with passive diffusion mechanism. The absorption results in various segments of intestine showed that the main absorption sites were ileum and colon. It can be concluded that PBCNs as an oral carrier can significantly improve the oral absorption of a poorly soluble drug.

  2. Evaluation of an oral carrier system in rats: bioavailability and gastrointestinal absorption properties of curcumin encapsulated PBCA nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Sun Min; Zhao Lixia; Guo Chenyu; Cao Fengliang; Chen Huanlei; Zhao Liyan; Tan Qi; Zhu Xiuqing; Zhu Fanping; Ding Tingting; Zhai Yingjie; Zhai Guangxi, E-mail: professorzhai@yeah.net [Shandong University, Department of Pharmaceutics, College of Pharmacy (China)

    2012-02-15

    A new oral delivery system, polybutylcyanoacrylate nanoparticles (PBCNs), was introduced to improve the oral bioavailability of curcumin (CUR), a poorly soluble drug. The formulation was optimized by orthogonal design and the optimal PBCNs loading CUR exhibited a spherical shape under transmission electron microscopy with a range of 40-400 nm. Physicochemical state of CUR in PBCN was investigated by X-ray diffraction and the possible structure changes occurring in CUR after conjugating with polybutylcyanoacrylate were studied with FTIR. The results indicated that CUR in PBCN was in a non-crystalline state and CUR was encapsulated in PBCN without chemical reaction. The oral pharmacokinetic study was conducted in rats and the relative bioavailability of CUR encapsulated PBCNs to the crude CUR was more than 800%. The in situ absorption experiment in rat intestine indicated the absorption was first order with passive diffusion mechanism. The absorption results in various segments of intestine showed that the main absorption sites were ileum and colon. It can be concluded that PBCNs as an oral carrier can significantly improve the oral absorption of a poorly soluble drug.

  3. Study of absorption and re-emission processes in a ternary liquid scintillation system

    International Nuclear Information System (INIS)

    Xiao Hualin; Wang Naiyan; Li Xiaobo; Cao Jun; Wen Liangjian; Zheng Dong

    2010-01-01

    Liquid scintillators are widely used as the neutrino target in neutrino experiments. The absorption and emission of different components of a ternary liquid scintillator (Linear Alkyl Benzene (LAB) as the solvent, 2, 5-diphenyloxazole (PPO) as the fluor and p-bis-(o-methylstyryl)-benzene (bis-MSB) as wavelength shifter) are studied. It is shown that the absorption of this liquid scintillator is dominant by LAB and PPO at wavelengths less than 349 nm, and the absorption by bis-MSB becomes prevalent at the wavelength larger than 349 nm. The fluorescence quantum yields, which are the key parameters to model the absorption and re-emission processes in large liquid scintillation detectors, are measured. (authors)

  4. Optimal design of solid oxide fuel cell, ammonia-water single effect absorption cycle and Rankine steam cycle hybrid system

    Science.gov (United States)

    Mehrpooya, Mehdi; Dehghani, Hossein; Ali Moosavian, S. M.

    2016-02-01

    A combined system containing solid oxide fuel cell-gas turbine power plant, Rankine steam cycle and ammonia-water absorption refrigeration system is introduced and analyzed. In this process, power, heat and cooling are produced. Energy and exergy analyses along with the economic factors are used to distinguish optimum operating point of the system. The developed electrochemical model of the fuel cell is validated with experimental results. Thermodynamic package and main parameters of the absorption refrigeration system are validated. The power output of the system is 500 kW. An optimization problem is defined in order to finding the optimal operating point. Decision variables are current density, temperature of the exhaust gases from the boiler, steam turbine pressure (high and medium), generator temperature and consumed cooling water. Results indicate that electrical efficiency of the combined system is 62.4% (LHV). Produced refrigeration (at -10 °C) and heat recovery are 101 kW and 22.1 kW respectively. Investment cost for the combined system (without absorption cycle) is about 2917 kW-1.

  5. Determining CDOM Absorption Spectra in Diverse Coastal Environments Using a Multiple Pathlength, Liquid Core Waveguide System. Measuring the Absorption of CDOM in the Field Using a Multiple Pathlength Liquid Waveguide System

    Science.gov (United States)

    Miller, Richard L.; Belz, Mathias; DelCastillo, Carlos; Trzaska, Rick

    2000-01-01

    We evaluated the accuracy, sensitivity and precision of a multiple pathlength, liquid core waveguide (MPLCW) system for measuring colored dissolved organic matter (CDOM) absorption in the UV-visible spectral range (370-700 nm). The MPLCW has four optical paths (2.0, 9.8, 49.3, and 204 cm) coupled to a single Teflon AF sample cell. Water samples were obtained from inland, coastal and ocean waters ranging in salinity from 0 to 36 PSU. Reference solutions for the MPLCW were made having a refractive index of the sample. CDOM absorption coefficients, a(sub CDOM), and the slope of the log-linearized absorption spectra, S, were compared with values obtained using a dual-beam spectrophotometer. Absorption of phenol red secondary standards measured by the MPLCW at 558 nm were highly correlated with spectrophotometer values (r > 0.99) and showed a linear response across all four pathlengths. Values of a(sub CDOM) measured using the MPLCW were virtually identical to spectrophotometer values over a wide range of concentrations. The dynamic range of a(sub CDOM) for MPLCW measurements was 0.002 - 231.5/m. At low CDOM concentrations (a(sub 370) CDOM) were slightly greater than MPLCW values and showed larger fluctuations at longer wavelengths due to limitations in instrument precision. In contrast, MPLCW spectra followed an exponential to 600 nm for all samples. The maximum deviation in replicate MPLCW spectra was less than 0.001 absorbance units. The portability, sampling, and optical characteristics of a MPLCW system provide significant enhancements for routine CDOM absorption measurements in a broad range of natural waters.

  6. X ray absorption fine structure of systems in the anharmonic limit

    Science.gov (United States)

    Mustredeleon, J.; Conradson, S. D.; Batistic, I.; Bishop, A. R.; Raistrick, I.; Jackson, W. E.; Brown, G. E.

    A new approach to the analysis of x-ray absorption fine structure (XAFS) data is presented. It is based on the use of radial distribution functions directly calculated from a single-particle ion Hamiltonian containing model potentials. The starting point of this approach is the statistical average of the XAFS for an atomic pair. This average can be computed using a radial distribution function (RDF), which can be expressed in terms of the eigenvalues and wavefunctions associated with the model potential. The pair potential describing the ionic motion is then expressed in terms of parameters that are determined by fitting this statistical average to the experimental XAFS spectrum. This approach allows the use of XAFS as a tool for mapping near-neighbor interatomic potentials, and allows the treatment of systems which exhibit strongly anharmonic potentials which can be treated by perturbative methods. Using this method we have analyzed the high temperature behavior of the oxygen contributions to the Fe K-edge XAFS in the ferrosilicate minerals andradite (Ca3Fe2Si3O12) and magnesiowustite (Mg(0.9)Fe(0.1)O). Using a temperature dependent anharmonic correction derived from these model compounds, we have found evidence for a local structural change in the Fe-O coordination environment upon melting of the geologically important mineral fayalite (Fe2SiO4). We have also employed this method to the study of the axial oxygen contributions to the polarized Cu K-edge XAFS on oriented samples of YBa2Cu3O7 and related compounds. From this study we find evidence for an axial oxygen-centered lattice distortion accompanying the superconducting phase transition and a correlation between this distortion and Tc. The relation of the observed lattice distortion to mechanisms of superconductivity is discussed.

  7. Tamsulosin oral controlled absorption system (OCAS in the treatment of benign prostatic hypertrophy

    Directory of Open Access Journals (Sweden)

    Mischel G Neill

    2008-03-01

    Full Text Available Mischel G Neill, Rohan Shahani, Alexandre R ZlottaDivision of Urology, Department of Surgical Oncology, Princess Margaret and Mount Sinai Hospitals, University of Toronto, Toronto, CanadaAbstract: The efficacy of tamsulosin at the cost of a relatively benign side effect profile has been attributed to receptor selectivity directed at the α1a and α1d adrenergic receptor subtypes. The oral-controlled absorption system (OCAS® represents a drug delivery refinement that incorporates a matrix of gel-forming and gel-enhancing agents to promote a constant drug release independent of environmental food or fluid. There are clinical data to support the concept that drug peaks are lessened and that drug release continues throughout the alimentary tract due to the OCAS formulation. Furthermore this equates with less adverse effects on physiologic parameters. To date however improvements in cardiovascular symptoms such as dizziness, headache and syncope have not been demonstrated in healthy men. Ejaculatory dysfunction appears less problematic with the OCAS preparation. Tamsulosin OCAS may be of greatest benefit to men with cardiovascular co-morbidities taking anti-hypertensive medications that might predispose them to symptomatic hypotensive episodes. It will be necessary to evaluate this group of men more closely in further trials to determine what they stand to gain from changing medications, and then relate this to drug costs to draw a final conclusion as to the place of tamsulosin OCAS in contemporary urological practice.Keywords: lower urinary tract symptoms, benign prostatic hyperplasia, tamsulosin OCAS, safety, efficacy, tolerability

  8. X-ray absorption fine structure of systems in the anharmonic limit

    International Nuclear Information System (INIS)

    Mustre de Leon, J.; Conradson, S.D.; Batistic, I.; Bishop, A.R.; Raistrick, I.; Jackson, W.E.; Brown, G.E.

    1991-01-01

    A new approach to the analysis of x-ray absorption fine structure (XAFS) data is presented. It is based on the use of radial distribution functions directly calculated from a single-particle ion hamiltonian containing model potentials. The starting point of this approach is the statistical average of the XAFS for an atomic pair. This average can be computed using a radial distribution function (RDF), which can be expressed in terms of the eigenvalues and wavefunctions associated with the model potential. The pair potential describing the ionic motion is then expressed in terms of parameters that are determined by fitting this statistical average to the experimental XAFS spectrum. This approach allow the use of XAFS as a tool for mapping near-neighbor interatomic potentials, and allows the treatment of systems which exhibit strongly anharmonic potentials which can be treated by perturbative methods. Using this method we have analyzed the high temperature behavior of the oxygen contributions to the Fe K-edge XAFS in the ferrosilicate minerals andradite (Ca 3 Fe 2 Si 3 O 12 ) and magnesiowustite (Mg 0.9 Fe 0.1 O). Using a temperature dependent anharmonic correction derived from these model compounds, we have found evidence for a local structural change in the Fe-O coordination environment upon melting of the geologically important mineral fayalite (Fe 2 SiO 4 ). We have also employed this method to the study of the axial oxygen contributions to the polarized Cu K-edge XAFS on oriented samples of YBa 2 Cu 3 O 7 and related compounds. From this study we find evidence for an axial oxygen-centered lattice distortion accompanying the superconducting phase transition and a correlation between this distortion and T c . The relation of the observed lattice distortion to mechanisms of superconductivity is discussed. 33 refs., 6 figs

  9. Effect of the hardener to epoxy monomer ratio on the water absorption behavior of the DGEBA/TETA epoxy system

    Directory of Open Access Journals (Sweden)

    Ayrton Alef Castanheira Pereira

    2016-02-01

    Full Text Available Abstract The water absorption behavior of the DGEBA/TETA epoxy system was evaluated as a function of the epoxy monomer to amine hardener ratio. Weight gain versus immersion time curves were obtained and the experimental points were fitted using Fickian and Non-Fickian diffusion models. The results obtained showed that for all epoxy monomer to hardener ratios analyzed water diffusion followed non-Fickian behavior. It was possible to correlate the water absorption behavior to the macromolecular structure developed when the epoxy/ hardener ratio was varied. All epoxy/hardener ratios present a two-phase macromolecular structure, composed of regions with high crosslink density and regions with lower crosslinking. Epoxy rich systems have a more open macromolecular structure with a lower fraction of the dense phase than the amine rich systems, which present a more compact two-phase structure.

  10. Measured performance of a 3 ton LiBr absorption water chiller and its effect on cooling system operation

    Science.gov (United States)

    Namkoong, D.

    1976-01-01

    A three ton lithium bromide absorption water chiller was tested for a number of conditions involving hot water input, chilled water, and the cooling water. The primary influences on chiller capacity were the hot water inlet temperature and the cooling water inlet temperature. One combination of these two parameters extended the output to as much as 125% of design capacity, but no combination could lower the capacity to below 60% of design. A cooling system was conceptually designed so that it could provide several modes of operation. Such flexibility is needed for any solar cooling system to be able to accommodate the varying solar energy collection and the varying building demand. It was concluded that a three-ton absorption water chiller with the kind of performance that was measured can be incorporated into a cooling system such as that proposed, to provide efficient cooling over the specified ranges of operating conditions.

  11. Measured performance of a 3-ton LiBr absorption water chiller and its effect on cooling system operation

    Science.gov (United States)

    Namkoong, D.

    1976-01-01

    A 3-ton lithium bromide absorption water chiller was tested for a number of conditions involving hot-water input, chilled water, and the cooling water. The primary influences on chiller capacity were the hot water inlet temperature and the cooling water inlet temperature. One combination of these two parameters extended the output to as much as 125% of design capacity, but no combination could lower the capacity to below 60% of design. A cooling system was conceptually designed so that it could provide several modes of operation. Such flexibility is needed for any solar cooling system to be able to accommodate the varying solar energy collection and the varying building demand. It is concluded that a 3-ton absorption water chiller with the kind of performance that was measured can be incorporated into a cooling system such as that proposed, to provide efficient cooling over the specified ranges of operating conditions.

  12. Analysis of hybrid membrane and chemical absorption systems for CO2 capture

    International Nuclear Information System (INIS)

    Binns, Michael; Oh, Se-Young; Kwak, Dong-Hun; Kim, Jin-Kuk

    2015-01-01

    Amine-based absorption of CO 2 is currently the industry standard technology for capturing CO 2 emitted from power plants, refineries and other large chemical plants. However, more recently there have been a number of competing technologies under consideration, including the use of membranes for CO 2 separation and purification. We constructed and analyzed two different hybrid configurations combining and connecting chemical absorption with membrane separation. For a particular flue gas which is currently treated with amine-based chemical absorption at a pilot plant we considered and tested how membranes could be integrated to improve the performance of the CO 2 capture. In particular we looked at the CO 2 removal efficiency and the energy requirements. Sensitivity analysis was performed varying the size of the membranes and the solvent flow rate

  13. Solar hybrid cooling system for high-tech offices in subtropical climate - Radiant cooling by absorption refrigeration and desiccant dehumidification

    International Nuclear Information System (INIS)

    Fong, K.F.; Chow, T.T.; Lee, C.K.; Lin, Z.; Chan, L.S.

    2011-01-01

    Highlights: → A solar hybrid cooling system is proposed for high-tech offices in subtropical climate. → An integration of radiant cooling, absorption refrigeration and desiccant dehumidification. → Year-round cooling and energy performances were evaluated through dynamic simulation. → Its annual primary energy consumption was lower than conventional system up to 36.5%. → The passive chilled beams were more energy-efficient than the active chilled beams. - Abstract: A solar hybrid cooling design is proposed for high cooling load demand in hot and humid climate. For the typical building cooling load, the system can handle the zone cooling load (mainly sensible) by radiant cooling with the chilled water from absorption refrigeration, while the ventilation load (largely latent) by desiccant dehumidification. This hybrid system utilizes solar energy for driving the absorption chiller and regenerating the desiccant wheel. Since a high chilled water temperature generated from the absorption chiller is not effective to handle the required latent load, desiccant dehumidification is therefore involved. It is an integration of radiant cooling, absorption refrigeration and desiccant dehumidification, which are powered up by solar energy. In this study, the application potential of the solar hybrid cooling system was evaluated for the high-tech offices in the subtropical climate through dynamic simulation. The high-tech offices are featured with relatively high internal sensible heat gains due to the intensive office electric equipment. The key performance indicators included the solar fraction and the primary energy consumption. Comparative study was also carried out for the solar hybrid cooling system using two common types of chilled ceilings, the passive chilled beams and active chilled beams. It was found that the solar hybrid cooling system was technically feasible for the applications of relatively higher cooling load demand. The annual primary energy

  14. Mini-DIAL system measurements coupled with multivariate data analysis to identify TIC and TIM simulants: preliminary absorption database analysis

    International Nuclear Information System (INIS)

    Gaudio, P; Malizia, A; Gelfusa, M; Poggi, L.A.; Martinelli, E.; Di Natale, C.; Bellecci, C.

    2017-01-01

    Nowadays Toxic Industrial Components (TICs) and Toxic Industrial Materials (TIMs) are one of the most dangerous and diffuse vehicle of contamination in urban and industrial areas. The academic world together with the industrial and military one are working on innovative solutions to monitor the diffusion in atmosphere of such pollutants. In this phase the most common commercial sensors are based on “point detection” technology but it is clear that such instruments cannot satisfy the needs of the smart cities. The new challenge is developing stand-off systems to continuously monitor the atmosphere. Quantum Electronics and Plasma Physics (QEP) research group has a long experience in laser system development and has built two demonstrators based on DIAL (Differential Absorption of Light) technology could be able to identify chemical agents in atmosphere. In this work the authors will present one of those DIAL system, the miniaturized one, together with the preliminary results of an experimental campaign conducted on TICs and TIMs simulants in cell with aim of use the absorption database for the further atmospheric an analysis using the same DIAL system. The experimental results are analysed with standard multivariate data analysis technique as Principal Component Analysis (PCA) to develop a classification model aimed at identifying organic chemical compound in atmosphere. The preliminary results of absorption coefficients of some chemical compound are shown together pre PCA analysis. (paper)

  15. Development of sound absorption measuring system with acoustic chamber; Kogata kyuon koka sokutei sochi no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Takahira, M.; Noba, M. [Toyota Motor Corp., Aichi (Japan); Matsuoka, H. [Nippon Soken, Inc., Tokyo (Japan)

    1998-05-01

    In order to measure sound absorption performance necessary to develop sound absorption materials, development was made on a device consisting of a small sound box capable of measurement inexpensively and easily, as a measure against the reverberation chamber method. In order to obtain stabilized diffusion sound internally, the sound box has a shape of asymmetric seven-side body in which sides do not face squarely with each other. The box was so sized that a large number of resonant vibration postures can be constituted at the targeted frequency simultaneously in the box. The box has a commercially available cone speaker with good acoustic output characteristics in frequency range of higher than 500 Hz installed on an inner side of the box. The sound source uses a method to derive sound absorption rate from difference of sound pressure levels. In order to eliminate need of averaging treatment by using a multi-point measurement inside the box, a discussion was given to provide an opening on part of the box to place the sound receiving point outside the opening. A square test piece is placed on the floor 0.5 meter or more away from the speaker in the box. As a result of the experiment, it was verified that the sound absorption rate obtained by this device corresponds well with that by the reverberation chamber method. The size of the test piece was also found adequate. 2 refs., 11 figs., 1 tab.

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

    International Nuclear Information System (INIS)

    Cornelius, Andrew L.

    2016-01-01

    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.

  17. Synthesis of Hα absorption in old stellar systems: formation of the cluster red sequence by `downsizing'

    Science.gov (United States)

    Smith, Russell J.

    2005-05-01

    We compute population synthesis models for the variation of Hα absorption indices (HαA and HαF), as a function of age and metallicity in old stellar systems. The models are based on the STELIB spectral library of Le Borgne et al., and defined at a resolution of 3Åfull width at half-maximum. Errors in the age and metallicity responses are derived by bootstrap resampling the input measurements on the stellar library. The indices are found to be highly sensitive to age variation, with only moderate response to metallicity. For galaxies uncontaminated by nebular emission, our HαA index is more powerful in breaking the age-metallicity degeneracy than Hβ or HγF. Using a sample of red cluster galaxies from Nelan et al., carefully selected to exclude objects with emission, we find a steep decline of HαA with velocity dispersion (slope -0.75 +/- 0.07Ådex-1). The slope can be translated to constraints on age and metallicity scaling relations, incorporating measurement errors and also the model errors determined from the bootstrap method. If the HαA-σ slope is due only to age, we obtain Age ~σ0.95+/-0.12. Because HαA depends quite weakly on [Fe/H], a metallicity interpretation would require Fe/H ~σ1.2 or steeper. The HαA-σ slope is consistent with the combined age and metallicity scaling relations reported by Nelan et al. from classical Lick indices. The relations obtained by Thomas et al. significantly underpredict the observed slope. The discrepancy could arise from differences in the sample selection. In particular, our sample probes a lower mass range, is not explicitly selected on morphological criteria, and excludes objects significantly bluer than the red sequence. We discuss in detail the impact of emission contamination on the results, and conclude that this effect is unlikely to yield the observed behaviour in the Hα-σ relations. Indeed, similar results are obtained using HαF, despite its different sensitivity to Hα and [NII] emission lines. The

  18. Development and operation of a real-time data acquisition system for the NASA-LaRC differential absorption lidar

    Science.gov (United States)

    Butler, C.

    1985-01-01

    Computer hardware and software of the NASA multipurpose differential absorption lidar (DIAL) sysatem were improved. The NASA DIAL system is undergoing development and experimental deployment for remote measurement of atmospheric trace gas concentration from ground and aircraft platforms. A viable DIAL system was developed with the capability of remotely measuring O3 and H2O concentrations from an aircraft platform. Test flights were successfully performed on board the NASA/Goddard Flight Center Electra aircraft from 1980 to 1984. Improvements on the DIAL data acquisition system (DAS) are described.

  19. Systemic absorption and adverse ocular and systemic effects after topical ophthalmic administration of 0.1% diclofenac to healthy cats.

    Science.gov (United States)

    Hsu, Kimberly K; Pinard, Chantale L; Johnson, Ron J; Allen, Dana G; KuKanich, Butch K; Nykamp, Stephanie G

    2015-03-01

    To quantify plasma concentrations and determine adverse ocular, renal, or hepatic effects associated with repeated topical ophthalmic application of 0.1% diclofenac to healthy cats. 8 healthy sexually intact male cats. A randomized, placebo-controlled crossover study was conducted. A topical formulation of 0.1% diclofenac was administered 4 times/d for 7 days to 4 cats, and artificial tear (control) solution was administered to the other 4 cats. After a 12-day washout period, cats received the other treatment. Ophthalmic examinations were performed daily. Plasma samples were obtained on days 1 and 7 for pharmacokinetic analysis. A CBC, serum biochemical analysis, urinalysis, determination of urine protein-to-creatinine ratio, and determination of glomerular filtration rate were performed before the start of the study and after each 7-day treatment period. Mild conjunctival hyperemia was the only adverse ocular effect detected. Maximal drug concentration and area under the curve were significantly higher on day 7 than on day 1. Diclofenac-treated cats had a significantly lower glomerular filtration rate than did control-treated cats after the second but not after the first treatment period, presumably associated with iatrogenic hypovolemia. Topical ophthalmic administration of 0.1% diclofenac was well tolerated in healthy cats, with only mild signs of ocular irritation. Detectable systemic concentrations of diclofenac were achieved with accumulation over 7 days. Systemic absorption of diclofenac may be associated with reduced glomerular filtration rate, particularly in volume-contracted animals. Topical ophthalmic 0.1% diclofenac should be used with caution in volume-contracted or systemically ill cats.

  20. Thermodynamic analysis of an absorption refrigeration system used to cool down the intake air in an Internal Combustion Engine

    International Nuclear Information System (INIS)

    Novella, R.; Dolz, V.; Martín, J.; Royo-Pascual, L.

    2017-01-01

    Highlights: • Enough power in the exhaust gases is available to operate the absorption cycle. • Three engine operating points are presented in the article. • Improvement potential up to 4% is possible in the engine indicated efficiency. • Engine indicated efficiency benefit was experimentally confirmed by direct testing. - Abstract: This paper deals with the thermodynamic analysis of an absorption refrigeration cycle used to cool down the temperature of the intake air in an Internal Combustion Engine using as a heat source the exhaust gas of the engine. The solution of ammonia-water has been selected due to the stability for a wide range of operating temperatures and pressures and the low freezing point. The effects of operating temperatures, pressures, concentrations of strong and weak solutions in the absorption refrigeration cycle were examined to achieve proper heat rejection to the ambient. Potential of increasing Internal Combustion Engine efficiency and reduce pollutant emissions was estimated by means of theoretical models and experimental tests. In order to provide boundary conditions for the absorption refrigeration cycle and to simulate its effect on engine performance, a 0D thermodynamic model was used to reproduce the engine performance when the intake air is cooled. Furthermore, a detailed experimental work was carried out to validate the results in real engine operation. Theoretical results show how the absorption refrigeration system decreases the intake air flow temperature down to a temperature around 5 °C and even lower by using the bottoming waste heat energy available in the exhaust gases in a wide range of engine operating conditions. In addition, the theoretical analysis estimates the potential of the strategy for increasing the engine indicated efficiency in levels up to 4% also at the operating conditions under evaluation. Finally, this predicted benefit in engine indicated efficiency has been experimentally confirmed by direct

  1. Absorption heat pumps

    International Nuclear Information System (INIS)

    Formigoni, C.

    1998-01-01

    A brief description of the difference between a compression and an absorption heat pump is made, and the reasons why absorption systems have spread lately are given. Studies and projects recently started in the field of absorption heat pumps, as well as criteria usually followed in project development are described. An outline (performance targets, basic components) of a project on a water/air absorption heat pump, running on natural gas or LPG, is given. The project was developed by the Robur Group as an evolution of a water absorption refrigerator operating with a water/ammonia solution, which has been on the market for a long time and recently innovated. Finally, a list of the main energy and cost advantages deriving from the use of absorption heat pumps is made [it

  2. Contribution to analytical theory of neutron resonance absorption in heterogeneous reactor systems with cylindrical geometry

    International Nuclear Information System (INIS)

    Slipicevic, K.

    1968-12-01

    Following a review of the existing theories od resonance absorption this thesis includes a new approach for calculating the effective resonance integral of absorbed neutrons, new approximate formula for the penetration factor, an analysis of the effective resonance integral and the correction of the resonance integral taking into account the interference of potential and resonance dissipation. A separate chapter is devoted to calculation of the effective resonance integral for the regular reactor lattice with cylindrical fuel elements

  3. Förster resonance energy transfer, absorption and emission spectra in multichromophoric systems. III. Exact stochastic path integral evaluation.

    Science.gov (United States)

    Moix, Jeremy M; Ma, Jian; Cao, Jianshu

    2015-03-07

    A numerically exact path integral treatment of the absorption and emission spectra of open quantum systems is presented that requires only the straightforward solution of a stochastic differential equation. The approach converges rapidly enabling the calculation of spectra of large excitonic systems across the complete range of system parameters and for arbitrary bath spectral densities. With the numerically exact absorption and emission operators, one can also immediately compute energy transfer rates using the multi-chromophoric Förster resonant energy transfer formalism. Benchmark calculations on the emission spectra of two level systems are presented demonstrating the efficacy of the stochastic approach. This is followed by calculations of the energy transfer rates between two weakly coupled dimer systems as a function of temperature and system-bath coupling strength. It is shown that the recently developed hybrid cumulant expansion (see Paper II) is the only perturbative method capable of generating uniformly reliable energy transfer rates and emission spectra across a broad range of system parameters.

  4. Exergy and Exergoenvironmental Analysis of a CCHP System Based on a Parallel Flow Double-Effect Absorption Chiller

    Directory of Open Access Journals (Sweden)

    Ali Mousafarash

    2016-01-01

    Full Text Available A combined cooling, heating, and power (CCHP system which produces electricity, heating, and cooling is modeled and analyzed. This system is comprised of a gas turbine, a heat recovery steam generator, and a double-effect absorption chiller. Exergy analysis is conducted to address the magnitude and the location of irreversibilities. In order to enhance understanding, a comprehensive parametric study is performed to see the effect of some major design parameters on the system performance. These design parameters are compressor pressure ratio, gas turbine inlet temperature, gas turbine isentropic efficiency, compressor isentropic efficiency, and temperature of absorption chiller generator inlet. The results show that exergy efficiency of the CCHP system is higher than the power generation system and the cogeneration system. In addition, the results indicate that when waste heat is utilized in the heat recovery steam generator, the greenhouse gasses are reduced when the fixed power output is generated. According to the parametric study results, an increase in compressor pressure ratio shows that the network output first increases and then decreases. Furthermore, an increase in gas turbine inlet temperature increases the system exergy efficiency, decreasing the total exergy destruction rate consequently.

  5. Automation of cell-based drug absorption assays in 96-well format using permeable support systems.

    Science.gov (United States)

    Larson, Brad; Banks, Peter; Sherman, Hilary; Rothenberg, Mark

    2012-06-01

    Cell-based drug absorption assays, such as Caco-2 and MDCK-MDR1, are an essential component of lead compound ADME/Tox testing. The permeability and transport data they provide can determine whether a compound continues in the drug discovery process. Current methods typically incorporate 24-well microplates and are performed manually. Yet the need to generate absorption data earlier in the drug discovery process, on an increasing number of compounds, is driving the use of higher density plates. A simple, more efficient process that incorporates 96-well permeable supports and proper instrumentation in an automated process provides more reproducible data compared to manual methods. Here we demonstrate the ability to perform drug permeability and transport assays using Caco-2 or MDCKII-MDR1 cells. The assay procedure was automated in a 96-well format, including cell seeding, media and buffer exchanges, compound dispense, and sample removal using simple robotic instrumentation. Cell monolayer integrity was confirmed via transepithelial electrical resistance and Lucifer yellow measurements. Proper cell function was validated by analyzing apical-to-basolateral and basolateral-to-apical movement of rhodamine 123, a known P-glycoprotein substrate. Apparent permeability and efflux data demonstrate how the automated procedure provides a less variable method than manual processing, and delivers a more accurate assessment of a compound's absorption characteristics.

  6. Fast Time-Dependent Density Functional Theory Calculations of the X-ray Absorption Spectroscopy of Large Systems.

    Science.gov (United States)

    Besley, Nicholas A

    2016-10-11

    The computational cost of calculations of K-edge X-ray absorption spectra using time-dependent density functional (TDDFT) within the Tamm-Dancoff approximation is significantly reduced through the introduction of a severe integral screening procedure that includes only integrals that involve the core s basis function of the absorbing atom(s) coupled with a reduced quality numerical quadrature for integrals associated with the exchange and correlation functionals. The memory required for the calculations is reduced through construction of the TDDFT matrix within the absorbing core orbitals excitation space and exploiting further truncation of the virtual orbital space. The resulting method, denoted fTDDFTs, leads to much faster calculations and makes the study of large systems tractable. The capability of the method is demonstrated through calculations of the X-ray absorption spectra at the carbon K-edge of chlorophyll a, C 60 and C 70 .

  7. Simulation of a combined heating, cooling and domestic hot water system based on ground source absorption heat pump

    International Nuclear Information System (INIS)

    Wu, Wei; You, Tian; Wang, Baolong; Shi, Wenxing; Li, Xianting

    2014-01-01

    Highlights: • A combined heating/cooling/DHW system based on GSAHP is proposed in cold regions. • The soil imbalance is effectively reduced and soil temperature can be kept stable. • 20% and 15% of condensation/absorption heat is recovered by GSAHP to produce DHW. • The combined system can improve the primary energy efficiency by 23.6% and 44.4%. - Abstract: The amount of energy used for heating and domestic hot water (DHW) is very high and will keep increasing. The conventional ground source electrical heat pump used in heating-dominated buildings has the problems of thermal imbalance, decrease of soil temperature, and deterioration of heating performance. Ground source absorption heat pump (GSAHP) is advantageous in both imbalance reduction and primary energy efficiency (PEE) improvement; however, the imbalance is still unacceptable in the warmer parts of cold regions. A combined heating/cooling/DHW (HCD) system based on GSAHP is proposed to overcome this problem. The GSAHPs using generator absorber heat exchange (GAX) and single-effect (SE) cycles are simulated to obtain the performance under various working conditions. Different HCD systems in Beijing and Shenyang are simulated comparatively in TRNSYS, based on which the thermal imbalance, soil temperature, heat recovery, and energy efficiency are analyzed. Results show that GSAHP–GAX–HCD is suitable for Beijing and GSAHP–SE–HCD is suitable for Shenyang. The imbalance ratio can be reduced to −14.8% in Beijing and to 6.0% in Shenyang with an annual soil temperature variation of only 0.5 °C and 0.1 °C. Furthermore, about 20% and 15% of the total condensation/absorption heat is recovered to produce DHW, and the PEE can reach 1.516 in Beijing and 1.163 in Shenyang. The combined HCD systems can achieve a PEE improvement of 23.6% and 44.4% compared with the normal heating/cooling systems

  8. Methylmercury determination using a hyphenated high performance liquid chromatography ultraviolet cold vapor multipath atomic absorption spectrometry system

    International Nuclear Information System (INIS)

    Campos, Reinaldo C.; Goncalves, Rodrigo A.; Brandao, Geisamanda P.; Azevedo, Marlo S.; Oliveira, Fabiana; Wasserman, Julio

    2009-01-01

    The present work investigates the use of a multipath cell atomic absorption mercury detector for mercury speciation analysis in a hyphenated high performance liquid chromatography assembly. The multipath absorption cell multiplies the optical path while energy losses are compensated by a very intense primary source. Zeeman-effect background correction compensates for non-specific absorption. For the separation step, the mobile phase consisted in a 0.010% m/v mercaptoethanol solution in 5% methanol (pH = 5), a C 18 column was used as stationary phase, and post column treatment was performed by UV irradiation (60 deg. C, 13 W). The eluate was then merged with 3 mol L -1 HCl, reduction was performed by a NaBH 4 solution, and the Hg vapor formed was separated at the gas-liquid separator and carried through a desiccant membrane to the detector. The detector was easily attached to the system, since an external gas flow to the gas-liquid separator was provided. A multivariate approach was used to optimize the procedure and peak area was used for measurement. Instrumental limits of detection of 0.05 μg L -1 were obtained for ionic (Hg 2+ ) and HgCH 3 + , for an injection volume of 200 μL. The multipath atomic absorption spectrometer proved to be a competitive mercury detector in hyphenated systems in relation to the most commonly used atomic fluorescence and inductively coupled plasma mass spectrometric detectors. Preliminary application studies were performed for the determination of methyl mercury in sediments.

  9. Methylmercury determination using a hyphenated high performance liquid chromatography ultraviolet cold vapor multipath atomic absorption spectrometry system

    Energy Technology Data Exchange (ETDEWEB)

    Campos, Reinaldo C. [Department of Chemistry, Pontifical Catholic University of Rio de Janeiro, Rua Marques de S Vicente 225, 22453-900 Rio de Janeiro (Brazil)], E-mail: rccampos@puc-rio.br; Goncalves, Rodrigo A.; Brandao, Geisamanda P.; Azevedo, Marlo S. [Department of Chemistry, Pontifical Catholic University of Rio de Janeiro, Rua Marques de S Vicente 225, 22453-900 Rio de Janeiro (Brazil); Oliveira, Fabiana; Wasserman, Julio [Institut of Geosciences, Fluminense Federal University, Av. Gal. Milton Tavares de Souza, s/n, 24.210-340, Niteroi, Rio de Janeiro (Brazil)

    2009-06-15

    The present work investigates the use of a multipath cell atomic absorption mercury detector for mercury speciation analysis in a hyphenated high performance liquid chromatography assembly. The multipath absorption cell multiplies the optical path while energy losses are compensated by a very intense primary source. Zeeman-effect background correction compensates for non-specific absorption. For the separation step, the mobile phase consisted in a 0.010% m/v mercaptoethanol solution in 5% methanol (pH = 5), a C{sub 18} column was used as stationary phase, and post column treatment was performed by UV irradiation (60 deg. C, 13 W). The eluate was then merged with 3 mol L{sup -1} HCl, reduction was performed by a NaBH{sub 4} solution, and the Hg vapor formed was separated at the gas-liquid separator and carried through a desiccant membrane to the detector. The detector was easily attached to the system, since an external gas flow to the gas-liquid separator was provided. A multivariate approach was used to optimize the procedure and peak area was used for measurement. Instrumental limits of detection of 0.05 {mu}g L{sup -1} were obtained for ionic (Hg{sup 2+}) and HgCH{sub 3}{sup +}, for an injection volume of 200 {mu}L. The multipath atomic absorption spectrometer proved to be a competitive mercury detector in hyphenated systems in relation to the most commonly used atomic fluorescence and inductively coupled plasma mass spectrometric detectors. Preliminary application studies were performed for the determination of methyl mercury in sedi0011men.

  10. Fate of chemicals in skin after dermal application: does the in vitro skin reservoir affect the estimate of systemic absorption?

    International Nuclear Information System (INIS)

    Yourick, Jeffrey J.; Koenig, Michael L.; Yourick, Debra L.; Bronaugh, Robert L.

    2004-01-01

    Recent international guidelines for the conduct of in vitro skin absorption studies put forward different approaches for addressing the status of chemicals remaining in the stratum corneum and epidermis/dermis at the end of a study. The present study investigated the fate of three chemicals [dihydroxyacetone (DHA), 7-(2H-naphtho[1,2-d]triazol-2-yl)-3-phenylcoumarin (7NTPC), and disperse blue 1 (DB1)] in an in vitro absorption study. In these studies, human and fuzzy rat skin penetration and absorption were determined over 24 or 72 h in flow-through diffusion cells. Skin penetration of these chemicals resulted in relatively low receptor fluid levels but high skin levels. For DHA, penetration studies found approximately 22% of the applied dose remaining in the skin (in both the stratum corneum and viable tissue) as a reservoir after 24 h. Little of the DHA that penetrates into skin is actually available to become systemically absorbed. 7NTPC remaining in the skin after 24 h was approximately 14.7% of the applied dose absorbed. Confocal laser cytometry studies with 7NTPC showed that it is present across skin in mainly the epidermis and dermis with intense fluorescence around hair. For DB1, penetration studies found approximately 10% (ethanol vehicle) and 3% (formulation vehicle) of the applied dose localized in mainly the stratum corneum after 24 h. An extended absorption study (72 h) revealed that little additional DB1 was absorbed into the receptor fluid. Skin levels should not be considered as absorbed material for DHA or DB1, while 7NTPC requires further investigation. These studies illustrate the importance of determining the fate of chemicals remaining in skin, which could significantly affect the estimates of systemically available material to be used in exposure estimates. We recommend that a more conclusive means to determine the fate of skin levels is to perform an extended study as conducted for DB1

  11. Application of the exergetic cost theory to the LiBr/H2O vapour absorption system

    International Nuclear Information System (INIS)

    Misra, R.D.; Sahoo, P.K.; Gupta, A.

    2002-01-01

    Optimization of thermal systems is generally based on thermodynamic analysis. However, the systems so optimized often are not viable due to economic constraints. The Theory of Exergetic Cost, a thermoeconomic optimization technique, combines the thermodynamic analysis with that of economic constraints to obtain an optimum configuration of a thermal system. In this paper, this technique is applied to optimize a LiBr/H 2 O vapour absorption refrigeration system run by pressurized hot water for air-conditioning applications. The mathematical and numerical techniques-based optimization of thermal systems is not always possible due to plant complexities. Hence, a simplified cost minimization methodology, based on 'Theory of Exergetic Cost', is applied to evaluate the economic costs of all the internal flows and products of the system under consideration. As shown in this paper, once these costs are determined, an approximately optimum design configuration can be obtained

  12. Evaluation of a flue gas driven open absorption system for heat and water recovery from fossil fuel boilers

    International Nuclear Information System (INIS)

    Wang, Zhenying; Zhang, Xiaoyue; Li, Zhen

    2016-01-01

    Highlights: • Flue gas driven open absorption system that efficiently recovers total heat. • Efficient heat and water recovery for various kinds of fossil fuel boilers. • Heat and water recovery efficiencies increase with moisture content of flue gas. • Temperature requirements for district heat supply and domestic hot water were met. • Experimental system surpasses conventional condensing system in total heat recovery. - Abstract: This paper presents an open absorption system for total heat recovery from fossil fuel boilers using the high temperature flue gas as the regeneration heat source. In this system, liquid desiccant serves as the recycling medium, which absorbs waste heat and moisture contained in the low temperature flue gas in the packed tower and then regenerates in the regenerator by the high temperature flue gas. Water vapor generated in the regenerator gets condensed after releasing heat to the heating water system and the condensing water also gets recycled. The return water collects heat from the solution water heat exchanger, the flue gas water heat exchanger and the condenser respectively and is then used for district heating. Driven by the vapor pressure difference between high humidity flue gas and the liquid desiccant, the heat recovery efficiency of the system is not limited by the dew point of the flue gas, enabling a warmer water to be heated up than the conventional condensing boiler. The performance of this system was analyzed theoretically and experimentally and the results showed that the system operated well for both district heat supply and domestic hot water supply. The system efficiency increased with the moisture content of flue gas and the total heat recovery was about 8.5%, 17.2%, 21.2%, and 9.2% higher than the conventional condensing system in the case of coal fired boiler, fuel oil boiler, natural gas boiler, and coke oven gas boiler, respectively.

  13. Calcium absorption

    International Nuclear Information System (INIS)

    Carlmark, B.; Reizenstein, P.; Dudley, R.A.

    1976-01-01

    The methods most commonly used to measure the absorption and retention of orally administered calcium are reviewed. Nearly all make use of calcium radioisotopes. The magnitude of calcium absorption and retention depends upon the chemical form and amount of calcium administered, and the clinical and nutritional status of the subject; these influences are briefly surveyed. (author)

  14. Optical absorption studies on biodegradable PVA/PVP blend polymer electrolyte system

    Science.gov (United States)

    Basha, S. K. Shahenoor; Reddy, K. Veera Bhadra; Rao, M. C.

    2018-05-01

    Biodegradable blend polymer electrolytes of PVA/PVP with different wt% ratios of MgCl2.6H2O have been prepared using solution cast technique. Optical absorption studies were carried-out on to the prepared films at room temperature using JASCO V-670 Spectrophotometer in the wavelength region 200-600 nm. Due to the clusters between the vibrations of molecules a broad peak is obtained due to п-п* transition in the wavelength region 310-340 nm.

  15. The mechanism and properties of bio-photon emission and absorption in protein molecules in living systems

    Science.gov (United States)

    Pang, Xiao-feng

    2012-05-01

    The mechanism and properties of bio-photon emission and absorption in bio-tissues were studied using Pang's theory of bio-energy transport, in which the energy spectra of protein molecules are obtained from the discrete dynamic equation. From the energy spectra, it was determined that the protein molecules could both radiate and absorb bio-photons with wavelengths of energy level transitions of the excitons. These results were consistent with the experimental data; this consisted of infrared absorption data from collagen, bovine serum albumin, the protein-like molecule acetanilide, plasma, and a person's finger, and the laser-Raman spectra of acidity I-type collagen in the lungs of a mouse, and metabolically active Escherichia coli. We further elucidated the mechanism responsible for the non-thermal biological effects produced by the infrared light absorbed by the bio-tissues, using the above results. No temperature rise was observed; instead, the absorbed infrared light promoted the vibrations of amides as well the transport of the bio-energy from one place to other in the protein molecules, which changed their conformations. These experimental results, therefore, not only confirmed the validity of the mechanism of bio-photon emission, and the newly developed theory of bio-energy transport mentioned above, but also explained the mechanism and properties of the non-thermal biological effects produced by the absorption of infrared light by the living systems.

  16. Design and analysis of a waste gasification energy system with solid oxide fuel cells and absorption chillers

    DEFF Research Database (Denmark)

    Rokni, Masoud

    2018-01-01

    Energy saving is an open point in most European countries where energy policies are oriented to reduce the use of fossil fuels, greenhouses emissions and energy independence, and to increase the use of renewable energies. In the last several years, new technologies have been developed and some...... of them received subsidies to increase installation and reduce cost. This article presents a new sustainable trigeneration system (power, heat and cool) based on a solid oxide fuel cell (SOFC) system integrated with an absorption chiller for special applications such as hotels, resorts, hospitals, etc....... with a focus on plant design and performance. The proposal system is based on the idea of gasifying the municipal waste, producing syngas serving as fuel for the trigeneration system. Such advanced system when improved is thus self-sustainable without dependency on net grid, district heating and district...

  17. Absorption studies

    International Nuclear Information System (INIS)

    Ganatra, R.D.

    1992-01-01

    Absorption studies were once quite popular but hardly anyone does them these days. It is easier to estimate the blood level of the nutrient directly by radioimmunoassay (RIA). However, the information obtained by estimating the blood levels of the nutrients is not the same that can be obtained from the absorption studies. Absorption studies are primarily done to find out whether some of the essential nutrients are absorbed from the gut or not and if they are absorbed, to determine how much is being absorbed. In the advanced countries, these tests were mostly done to detect pernicious anaemia where vitamin B 12 is not absorbed because of the lack of the intrinsic factor in the stomach. In the tropical countries, ''malabsorption syndrome'' is quire common. In this condition, several nutrients like fat, folic acid and vitamin B 12 are not absorbed. It is possible to study absorption of these nutrients by radioisotopic absorption studies

  18. Low redshift Lyman alpha absorption lines and the dark matter halos of disk galaxies

    Science.gov (United States)

    Maloney, Philip

    1993-01-01

    Recent observations using the Hubble Space Telescope of the z = 0.156 QSO 3C 273 have discovered a surprisingly large number of Ly-alpha absorption lines. In particular, Morris et al. found 9 certain and 7 possible Ly-alpha lines with equivalent widths above 25 mA. This is much larger (by a factor of 5-10) than the number expected from extrapolation of the high-redshift behavior of the Ly-alpha forest. Within the context of pressure-confined models for the Ly-alpha clouds, this behavior can be understood if the ionizing background declines sharply between z is approximately 2 and z is approximately 0. However, this requires that the ionizing photon flux drop as rapidly as the QSO volume emissivity; moreover, the absorbers must have a space density n(sub O) is approximately 2.6(N/10)h/((D/100 kpc)(sup 2)) Mpc(sup -3) where D is the present-day diameter of the absorbers. It is somewhat surprising that such necessarily fragile objects could have survived in such numbers to the present day. It is shown that it is plausible that the atomic hydrogen extents of spiral and irregular galaxies are large enough to produce the observed number of Ly-alpha absorption lines toward 3C 273, and that the neutral column densities and doppler b-values expected under these conditions fall in the range found by Morris et al. (1991).

  19. Infrared reflection absorption spectroscopy study of radiation-heterogeneous processes in the system of aluminum-hexane

    International Nuclear Information System (INIS)

    Gadzhieva, N.N.; Rimikhanova, A.N.; Garibov, A.A.

    2004-01-01

    Full text: Infrared reflection absorption spectroscopy (IRRAS) was applied to study the regularities of radiation conversion of hexane on the surface of aluminum. The research object was the thin polished aluminum plate by mark of AD-00 with reflection coefficient R=0.8†0.85 in infrared range λ=2.2†15 μ . As adsorbate unsaturated vapors of spectroscopy clear hexane were used. The absorption of hexane (C 2 H 14 ) was being studied manometric at pressures P=(0.1†1.0)·10 2 Pa , what corresponded to monolayer value of 1-10. The samples were irradiated with γ-quanta of 60 Co with D=1.03 Gy·s -1 doze rate. Infrared reflection spectrum when linear-polarized radiation fall on the sample under angle ψ=10 o was measured by spectrophotometer 'Specord 71 JR' in diapason of 4000-650cm -1 at the temperature by mean of special reflecting arrangements. Formation of molecular hydrogen (H 2 ) and other gaseous products of decomposition were controlled by chromotographical and infrared spectroscopical methods. The analysis of hexane infrared absorption spectra after radiation-stimulated adsorption on the surface of aluminum, points out the formation of H-bonded hydrocarbon complex ( ν∼2680cm -1 ) with much loosening of C-H bond (the molecular form of absorption) and the possibility of proceeding dissociative absorption with formation of metal-alkyls (ν∼2880, 2920, 2970 cm -1 ). Probability of the last mentioned process, which proceeds in the most defective centers, increases with increasing of γ-radiation doze. It was established that the radiation processes in hetero system Al-ads.C 6 H 14 accelerate the radiolysis of hexane. At all these the radiation decomposition of hexane in hetero system Al-ads.C 6 H 14 is accompanied by formation the surface hydrides (ν∼1700-2000 cm -1 ), acetylene (ν∼3200-3300 cm -1 ), ethylene (ν∼980 cm -1 ), and also gaseous products of molecular hydrogen decomposition (H 2 ) and hydrocarbons C 1 -C 5 (bands with maxima 770, 790

  20. Atomic absorption determination of ultratrace tellurium in rocks utilizing high sensitivity sampling systems

    International Nuclear Information System (INIS)

    Beaty, R.D.

    1973-01-01

    The sampling boat and the graphite furnace were shown to possess the required sensitivity to detect tellurium at ultratrace levels, in a variety of sample types, by atomic absorption. In the sampling boat approach, tellurium in sample solutions is chemically separated and concentrated by extraction into methyl isobutyl ketone before measurement. For samples exhibiting extraction interferences or excessively high background absorption, a preliminary separation of tellurium by coprecipitation with selenium is described. Using this technique, tellurium can be quantitatively detected down to 5 nanograms and linear response is observed to 100 nanograms. Relative standard deviations of better than 7 percent are achieved for 50 nanograms of tellurium. For samples that have a tellurium content below the detection limits of the sampling boat, the graphite furnace is used for atomization. By this method, as little as 0.07 nanograms of tellurium can be detected, and a precision of 1 percent relative standard deviation is achievable at the 5 nanogram level. A routinely applicable procedure was developed for determining tellurium in rocks, using the graphite furnace, after a hydrofluoric acid decomposition of the sample. Using this procedure, tellurium data were obtained on 20 different rocks, and the significance of this new information is discussed. (Diss. Abstr. Int., B)

  1. Plasmon-enhanced absorption in a metal nanoparticles and photosynthetic molecules hybrid system

    Science.gov (United States)

    Fan, Zhiyuan; Govorov, Alexander

    2010-03-01

    Photosystem I from cyanobacteria is one of nature's most efficient light harvesting complexes, converting light energy into electronic energy with a quantum yield of 100% and an energy yield about 58%. It is very attractive to the nanotechnology community because of its nanoscale dimensions and excellent optoelectronic properties. This protein has the potential to be utilized in devices such as solar cells, electric switches, photo-detectors, etc. However, there is one limiting factor for potential applications of a single monolayer of these photosynthetic proteins. One monolayer absorbs less than 1% of sunlight's energy, despite their excellent optoelectronic properties. Recently, experiments [1] have been conducted to enhance light absorption with the assistance of metal nanoparticles as artificial antenna for the photosystem I. Here, we present a theoretical description of the strong plasmon-assisted interactions between the metal nanoparticles and the optical dipoles of the reaction centers observed in the experiments. The resonance and off-resonance plasmon effects enhance the electromagnetic fields around the photosystem-I molecules and, in this way, lead to enhanced absorption. [4pt] [1] I. Carmeli, I. Lieberman, L. Kraversky, Zhiyuan Fan, A. O. Govorov, G. Markovich, and S. Richter, submitted.

  2. Critical coupling and coherent perfect absorption for ranges of energies due to a complex gain and loss symmetric system

    International Nuclear Information System (INIS)

    Hasan, Mohammad; Ghatak, Ananya; Mandal, Bhabani Prasad

    2014-01-01

    We consider a non-Hermitian medium with a gain and loss symmetric, exponentially damped potential distribution to demonstrate different scattering features analytically. The condition for critical coupling (CC) for unidirectional wave and coherent perfect absorption (CPA) for bidirectional waves are obtained analytically for this system. The energy points at which total absorption occurs are shown to be the spectral singular points for the time reversed system. The possible energies at which CC occurs for left and right incidence are different. We further obtain periodic intervals with increasing periodicity of energy for CC and CPA to occur in this system. -- Highlights: •Energy ranges for CC and CPA are obtained explicitly for complex WS potential. •Analytical conditions for CC and CPA for PT symmetric WS potential are obtained. •Conditions for left and right CC are shown to be different. •Conditions for CC and CPA are shown to be that of SS for the time reversed system. •Our model shows the great flexibility of frequencies for CC and CPA

  3. Cooling performance and energy saving of a compression-absorption refrigeration system driven by a gas engine

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Z.G.; Guo, K.H. [Sun Yat-Sen University, Guangzhou (China). Engineering School

    2006-07-01

    The prototype of combined vapour compression-absorption refrigeration system was set up, where a gas engine drove directly an open screw compressor in a vapour compression refrigeration chiller and waste heat from the gas engine was used to operate absorption refrigeration cycle. The experimental procedure and results showed that the combined refrigeration system was feasible. The cooling capacity of the prototype reached about 589 kW at the Chinese rated conditions of air conditioning (the inlet and outlet temperatures of chilled water are 12 and 7{sup o}C, the inlet and outlet temperatures of cooling water are 30 and 35{sup o}C, respectively). Primary energy rate (PER) and comparative primary energy saving were used to evaluate energy utilization efficiency of the combined refrigeration system. The calculated results showed that the PER of the prototype was about 1.81 and the prototype saved more than 25% of primary energy compared to a conventional electrically driven vapour compression refrigeration unit. Error analysis showed that the total error of the combined cooling system measurement was about 4.2% in this work. (author)

  4. Use of process steam in vapor absorption refrigeration system for cooling and heating applications: An exergy analysis

    Directory of Open Access Journals (Sweden)

    S. Anand

    2016-12-01

    Full Text Available The exponential increase in cost of conventional fuels shifts the interest toward the use of alternative as well waste energy sources for the operation of refrigeration and air-conditioning units. The present study therefore analyzes the performance of a process steam-operated vapor absorption system for cooling and heating applications using ammonia and water as working fluids based on first and second laws of thermodynamics. A mathematical model has been developed based on exergy analysis to investigate the performance of the system. The different performance parameters such as coefficient of performance (COP and exergetic efficiency of absorption system for cooling and heating applications are also calculated under different operating conditions. The results obtained show that cooling and heating COP along with second law efficiency (exergy efficiency increases with the heat source temperature at constant evaporator, condenser, and absorber temperature. Also, COP as well as exergy efficiency increases with an increase in the evaporator temperature at constant generator, condenser, and absorber temperature. The effect of ambient temperature on the exergetic efficiency for cooling and heating applications is also studied. The results obtained from the simulation studies can be used to optimize different components of the system so that the performance can be improved significantly.

  5. MODERATE C IV ABSORBER SYSTEMS REQUIRE 10{sup 12} M{sub Sun} DARK MATTER HALOS AT z {approx} 2.3: A CROSS-CORRELATION STUDY OF C IV ABSORBER SYSTEMS AND QUASARS IN SDSS-III BOSS DR9

    Energy Technology Data Exchange (ETDEWEB)

    Vikas, Shailendra; Wood-Vasey, W. Michael [Pittsburgh Particle Physics, Astrophysics, and Cosmology Center (PITT PACC), Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA 15260 (United States); Lundgren, Britt [Department of Physics, Yale University, New Haven, CT 06511 (United States); Ross, Nicholas P. [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 92420 (United States); Myers, Adam D. [Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071 (United States); AlSayyad, Yusra [Department of Astronomy, University of Washington, Seattle, WA 98195 (United States); York, Donald G. [Department of Astronomy, University of Chicago, 5640 S. Ellis Ave, Chicago, IL 60637 (United States); Schneider, Donald P. [Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States); Brinkmann, J.; Bizyaev, Dmitry; Brewington, Howard; Malanushenko, Elena; Malanushenko, Viktor; Oravetz, Daniel; Pan, Kaike; Snedden, Stephanie [Apache Point Observatory, P.O. Box 59, Sunspot, NM 88349-0059 (United States); Ge, Jian [Department of Astronomy, University of Florida, Gainesville, FL 32611 (United States); Muna, Demitri [Center for Cosmology and Particle Physics, New York University, New York, NY 10003 (United States); Paris, Isabelle; Petitjean, Patrick, E-mail: skv4@pitt.edu [UPMC-CNRS, UMR7095, Institut d' Astrophysique de Paris, F-75014 Paris (France); and others

    2013-05-01

    We measure the two-point cross-correlation function of C IV absorber systems and quasars, using spectroscopic data from the Sloan Digital Sky Survey III Baryon Oscillation Spectroscopic Survey (BOSS; Data Release 9). The 19,701 quasars and 6149 C IV ''moderate'' absorbers, 0.28 A < rest-frame equivalent width (EW) < 5 A, in our study cover a redshift range of 2.1 < z < 2.5 over 3300 deg{sup 2} and represent a factor of two increase in sample size over previous investigations. We find a correlation scale length and slope of the redshift-space cross-correlation function of s{sub 0} = 8.46 {+-} 1.24 Mpc, {gamma} = 1.68 {+-} 0.19, in the redshift-space range 10 < s < 100 Mpc. We find a projected cross-correlation function of C IV absorption systems and quasars of r{sub 0} = 7.76 {+-} 2.80 Mpc, {gamma} = 1.74 {+-} 0.21. We measure the combined quasar and C IV bias to be b{sub QSO} b{sub C{sub IV}} = 8.81 {+-} 2.28. Using an estimate of b{sub QSO} from the quasar auto-correlation function we find b{sub CIV} = 2.38 {+-} 0.62. This b{sub CIV} implies that EW > 0.28 A C IV absorbers at z {approx} 2.3 are typically found in dark matter halos that have masses {>=}10{sup 11.3}-10{sup 13.4} M{sub Sun} at that redshift. The complete BOSS sample will triple the number of both quasars and absorption systems and increase the power of this cross-correlation measurement by a factor of two.

  6. A comprehensive, multi-objective optimization of solar-powered absorption chiller systems for air-conditioning applications

    International Nuclear Information System (INIS)

    Shirazi, Ali; Taylor, Robert A.; Morrison, Graham L.; White, Stephen D.

    2017-01-01

    Highlights: • Multi-objective optimization of solar single/multi-effect absorption chillers was conducted. • Primary energy consumption and total annual cost were considered as the objectives. • Optimized designs of the alternative configurations were compared. • A detailed sensitivity analysis of the Pareto optimal solutions was investigated. - Abstract: Solar heating and cooling (SHC) systems are currently under rapid development and deployment due to their potential to reduce the use of fossil fuel resources and to alleviate greenhouse gas emissions in the building sector – a sector which is responsible for ∼40% of the world energy use. Absorption chiller technology (traditionally powered by natural gas in large buildings), can easily be retrofitted to run on solar energy. However, numerous non-intuitive design choices must be analyzed to achieve the best techno-economic performance of these systems. To date, there has been little research into the optimal configurations among the long list of potential solar-driven absorption chiller systems. To address this lack of knowledge, this paper presents a systematic simulation-based, multi-objective optimization of three common, commercially available lithium bromide-water absorption chillers – single-effect, double-effect and triple-effect – powered by evacuated tube collectors (ETCs), evacuated flat plate collectors (EFPCs), and concentrating parabolic trough collectors (PTCs), respectively. To the best of authors’ knowledge, this is the first study of its kind that compares the optimized designs of the most promising configurations of solar-assisted absorption chillers against a common set of energy, economic, and environmental metrics from a holistic perspective. A simulation model of these three configurations is developed using TRNSYS 17. A combined energy, economic, and environmental analysis of the modeled systems is conducted to calculate the primary energy use as well as the levelized total

  7. Fixed-wavelength H2O absorption spectroscopy system enhanced by an on-board external-cavity diode laser

    International Nuclear Information System (INIS)

    Brittelle, Mack S; Simms, Jean M; Sanders, Scott T; Gord, James R; Roy, Sukesh

    2016-01-01

    We describe a system designed to perform fixed-wavelength absorption spectroscopy of H 2 O vapor in practical combustion devices. The system includes seven wavelength-stabilized distributed feedback (WSDFB) lasers, each with a spectral accuracy of  ±1 MHz. An on-board external cavity diode laser (ECDL) that tunes 1320–1365 nm extends the capabilities of the system. Five system operation modes are described. In one mode, a sweep of the ECDL is used to monitor each WSDFB laser wavelength with an accuracy of  ±30 MHz. Demonstrations of fixed-wavelength thermometry at 10 kHz bandwidth in near-room-temperature gases are presented; one test reveals a temperature measurement error of ∼0.43%. (paper)

  8. Performance analysis of solar air cooled double effect LiBr/H2O absorption cooling system in subtropical city

    International Nuclear Information System (INIS)

    Li, Zeyu; Ye, Xiangyang; Liu, Jinping

    2014-01-01

    Highlights: • The meteorological data during the working period of air conditioning was measured. • The suitable working range of collector temperature of system was gotten. • The characteristic of hourly and monthly total efficiency of system were obtained. • The yearly performance of system was calculated. - Abstract: Due to the absence of cooling tower and independent on water, the air cooled solar double effect LiBr/H 2 O absorption cooling system is more convenient to be used in commercial building and household use. The performance with collector temperature is an important field for such system. The paper mainly deals with the performance with collector temperature for the solar air cooled double effect LiBr/H 2 O absorption cooling system in subtropical city. The parameters of system are: aperture area of collector array is 27 m 2 , tilted angle of collector with respect to the horizontal plane is 20 toward to south evaporator temperature is 5 °C and the cooling capacity is 20 kW. The simulation is based on the meteorological data of monthly typical day which was summarized from a year round measured data. A corresponding parametric model was developed. The hourly and average performance with the collector temperature for monthly typical day was obtained and discussed. It was found that the suitable working range of inlet temperature of collector is 110–130 °C to improve performance and lower the risk of crystallization. The difference of hourly total efficiency in 9:00–16:00 is less, and the monthly total efficiency from May to October is approximate. The yearly performance of system including total efficiency, cooling capacity per area of collector and solar fraction was given. Furthermore, the effect of effectiveness of heat exchanger and pressure drop on total efficiency and solar fraction was studied and compared. The paper can serve as a preliminary investigation of solar air cooled double effect LiBr/H 2 O absorption cooling system in

  9. Folate absorption

    International Nuclear Information System (INIS)

    Baker, S.J.

    1976-01-01

    Folate is the generic term given to numerous compounds of pteroic acid with glutamic acid. Knowledge of absorption is limited because of the complexities introduced by the variety of compounds and because of the inadequacy of investigational methods. Two assay methods are in use, namely microbiological and radioactive. Techniques used to study absorption include measurement of urinary excretion, serum concentration, faecal excretion, intestinal perfusion, and haematological response. It is probably necessary to test absorption of both pteroylmonoglutamic acid and one or more polyglutamates, and such tests would be facilitated by availability of synthesized compounds labelled with radioactive tracers at specifically selected sites. (author)

  10. A system to measure suprathermal electron distribution functions in toroidal plasmas by electron cyclotron wave absorption

    International Nuclear Information System (INIS)

    Boyd, D.A.; Skiff, F.; Gulick, S.

    1997-01-01

    A two-chord, four-beam suprathermal electron diagnostic has been installed on TdeV (B>1.5 T, R=0.86 m, a=0.25 m). Resonant absorption of extraordinary mode electron cyclotron waves is measured to deduce the chordal averaged suprathermal electron distribution function amplitude at the resonant momentum. Simultaneously counterpropagating beams permit good refractive loss cancellation. A nonlinear frequency sweep leads to a concentration of appropriately propagating power in a narrow range of time of flight, thus increasing the signal-to-noise ratio and facilitating the rejection of spurious reflections. Numerous measurements of electron distribution functions have been obtained during lower-hybrid current-drive experiments. copyright 1997 American Institute of Physics

  11. SkyProbe: Real-Time Precision Monitoring in the Optical of the Absolute Atmospheric Absorption on the Telescope Science and Calibration Fields

    Science.gov (United States)

    Cuillandre, J.-C.; Magnier, E.; Sabin, D.; Mahoney, B.

    2016-05-01

    Mauna Kea is known for its pristine seeing conditions but sky transparency can be an issue for science operations since at least 25% of the observable (i.e. open dome) nights are not photometric, an effect mostly due to high-altitude cirrus. Since 2001, the original single channel SkyProbe mounted in parallel on the Canada-France-Hawaii Telescope (CFHT) has gathered one V-band exposure every minute during each observing night using a small CCD camera offering a very wide field of view (35 sq. deg.) encompassing the region pointed by the telescope for science operations, and exposures long enough (40 seconds) to capture at least 100 stars of Hipparcos' Tycho catalog at high galactic latitudes (and up to 600 stars at low galactic latitudes). The measurement of the true atmospheric absorption is achieved within 2%, a key advantage over all-sky direct thermal infrared imaging detection of clouds. The absolute measurement of the true atmospheric absorption by clouds and particulates affecting the data being gathered by the telescope's main science instrument has proven crucial for decision making in the CFHT queued service observing (QSO) representing today all of the telescope time. Also, science exposures taken in non-photometric conditions are automatically registered for a new observation at a later date at 1/10th of the original exposure time in photometric conditions to ensure a proper final absolute photometric calibration. Photometric standards are observed only when conditions are reported as being perfectly stable by SkyProbe. The more recent dual color system (simultaneous B & V bands) will offer a better characterization of the sky properties above Mauna Kea and should enable a better detection of the thinnest cirrus (absorption down to 0.01 mag., or 1%).

  12. X-ray absorption spectroscopy of diluted system by undulator photon source and multi-element solid-state detector

    CERN Document Server

    Tanida, H

    2001-01-01

    In order to measure the extended X-ray absorption fine structure (EXAFS) spectrum of an ultra-diluted system, an optics and detector control system for a synchrotron radiation beamline is developed. The undulator gap width is continuously tuned to obtain the maximum X-ray photon flux during the energy scan for the EXAFS measurement. A piezoelectric translator optimizes the parallelism of the double crystal in a monochromator at each measurement point to compensate for mechanical errors of the monochromator, resulting in a smooth and intense X-ray photon flux during the measurement. For a detection of a weak fluorescence signal from diluted samples, a 19-element solid-state detector and digital signal processor are used. A K-edge EXAFS spectrum of iron in a myoglobin aqueous solution with a concentration of 5.58 parts per million was obtained by this system.

  13. On design of absorption, regeneration and recovery system of low concentration hydrogen and tritium in He with titanium sponge

    International Nuclear Information System (INIS)

    Fukuhara, Masashi

    1978-01-01

    Design of a titanium sponge system to remove hydrogen from the helium coolant of high temperature gas-cooled reactors or fusion reactors is discussed in this paper. The data for the present purpose have been accumulated. The equilibrium relation of Ti-H 2 system was given by McQuillan. The present author of this paper obtained an absorption equilibrium diagram, and measurements were made for lower partial pressure than that of McQuillan's data. A breakthrough curve and an adsorption-desorption breakthrough curve of H 2 -Ti sponge system, and the regeneration characteristics of the Ti sponge were measured. As the results of experiments, it is said that tritium and hydrogen can be removed with a Ti sponge system. Examples of the design of a practical system are presented. A disposable system was designed for OGL-1 under the principle that the used Ti sponge is a solid radioactive waste. A regenerative system was designed as a system, in which solid radioactive wastes are not produced. An example of a recovery system is also presented. Discussion on the reason why the Ti-sponge has not been used is presented. (Kato, T.)

  14. Design of absorption, regeneration and recovery system of low concentration hydrogen and tritium in He with titanium sponge

    Energy Technology Data Exchange (ETDEWEB)

    Fukuhara, M [Kawasaki Heavy Industries Ltd., Kobe (Japan)

    1978-10-01

    Design of a titanium sponge system to remove hydrogen from the helium coolant of high temperature gas-cooled reactors or fusion reactors is discussed in this paper. The data for the present purpose have been accumulated. The equilibrium relation of Ti-H/sub 2/ system was given by McQuillan. The present author of this paper obtained an absorption equilibrium diagram, and measurements were made for lower partial pressure than that of McQuillan's data. A breakthrough curve and an adsorption-desorption breakthrough curve of H/sub 2/-Ti sponge system, and the regeneration characteristics of the Ti sponge were measured. As the results of experiments, it is said that tritium and hydrogen can be removed with a Ti sponge system. Examples of the design of a practical system are presented. A disposable system was designed for OGL-1 under the principle that the used Ti sponge is a solid radioactive waste. A regenerative system was designed as a system, in which solid radioactive wastes are not produced. An example of a recovery system is also presented. Discussion on the reason why the Ti-sponge has not been used is presented.

  15. Hubble Space Telescope Observations of Extended [O III]λ 5007 Emission in Nearby QSO2s: New Constraints on AGN Host Galaxy Interaction

    Science.gov (United States)

    Fischer, Travis C.; Kraemer, S. B.; Schmitt, H. R.; Longo Micchi, L. F.; Crenshaw, D. M.; Revalski, M.; Vestergaard, M.; Elvis, M.; Gaskell, C. M.; Hamann, F.; Ho, L. C.; Hutchings, J.; Mushotzky, R.; Netzer, H.; Storchi-Bergmann, T.; Straughn, A.; Turner, T. J.; Ward, M. J.

    2018-04-01

    We present a Hubble Space Telescope survey of extended [O III] λ5007 emission for a sample of 12 nearby (z continuing to be kinematically influenced by the central active galactic nucleus (AGN) out to an average radius of ∼1130 pc. These findings question the effectiveness of AGNs being capable of clearing material from their host bulge in the nearby universe and suggest that disruption of gas by AGN activity may prevent star formation without requiring evacuation. Additionally, we find a dichotomy in our targets when comparing [O III] radial extent and nuclear FWHM, where QSO2s with compact [O III] morphologies typically possess broader nuclear emission lines.

  16. SIMULATION OF SOLAR LITHIUM BROMIDE–WATER ABSORPTION COOLING SYSTEM WITH DOUBLE GLAZED FLAT PLATE COLLECTOR FOR ADRAR

    Directory of Open Access Journals (Sweden)

    ML CHOUGUI

    2014-12-01

    Full Text Available Adrar is a city in the Sahara desert, in southern Algeria known for its hot and dry climate, where a huge amount of energy is used for air conditioning. The aim of this research is to simulate a single effect lithium bromide–water absorption chiller coupled to a double-glazed flat plate collector to supply the cooling loads for a house of 200m2 in Adrar. The thermal energy is stored in an insulated thermal storage tank. The system was designed to cover a cooling load of 10.39KW for design day of July. Thermodynamic model was established to simulate the absorption cycle. The results have shown that the collector mass flow rate has a negligible effect on the minimum required collector area, but it has a significant effect on the optimum capacity of the storage tank. The minimum required collector area was about 65.3 m2, which could supply the cooling loads for the sunshine hours of the design day for July. The operation of the system has also been considered after sunset by saving solar energy.

  17. Effects of gastric pH on oral drug absorption: In vitro assessment using a dissolution/permeation system reflecting the gastric dissolution process.

    Science.gov (United States)

    Kataoka, Makoto; Fukahori, Miho; Ikemura, Atsumi; Kubota, Ayaka; Higashino, Haruki; Sakuma, Shinji; Yamashita, Shinji

    2016-04-01

    The aim of the present study was to evaluate the effects of gastric pH on the oral absorption of poorly water-soluble drugs using an in vitro system. A dissolution/permeation system (D/P system) equipped with a Caco-2 cell monolayer was used as the in vitro system to evaluate oral drug absorption, while a small vessel filled with simulated gastric fluid (SGF) was used to reflect the gastric dissolution phase. After applying drugs in their solid forms to SGF, SGF solution containing a 1/100 clinical dose of each drug was mixed with the apical solution of the D/P system, which was changed to fasted state-simulated intestinal fluid. Dissolved and permeated amounts on applied amount of drugs were then monitored for 2h. Similar experiments were performed using the same drugs, but without the gastric phase. Oral absorption with or without the gastric phase was predicted in humans based on the amount of the drug that permeated in the D/P system, assuming that the system without the gastric phase reflected human absorption with an elevated gastric pH. The dissolved amounts of basic drugs with poor water solubility, namely albendazole, dipyridamole, and ketoconazole, in the apical solution and their permeation across a Caco-2 cell monolayer were significantly enhanced when the gastric dissolution process was reflected due to the physicochemical properties of basic drugs. These amounts resulted in the prediction of higher oral absorption with normal gastric pH than with high gastric pH. On the other hand, when diclofenac sodium, the salt form of an acidic drug, was applied to the D/P system with the gastric phase, its dissolved and permeated amounts were significantly lower than those without the gastric phase. However, the oral absorption of diclofenac was predicted to be complete (96-98%) irrespective of gastric pH because the permeated amounts of diclofenac under both conditions were sufficiently high to achieve complete absorption. These estimations of the effects of

  18. Assessment of the performance of a compact concentric spectrometer system for Atmospheric Differential Optical Absorption Spectroscopy

    Science.gov (United States)

    Whyte, C.; Leigh, R. J.; Lobb, D.; Williams, T.; Remedios, J. J.; Cutter, M.; Monks, P. S.

    2009-12-01

    A breadboard demonstrator of a novel UV/VIS grating spectrometer has been developed based upon a concentric arrangement of a spherical meniscus lens, concave spherical mirror and curved diffraction grating suitable for a range of atmospheric remote sensing applications from the ground or space. The spectrometer is compact and provides high optical efficiency and performance benefits over traditional instruments. The concentric design is capable of handling high relative apertures, owing to spherical aberration and comma being near zero at all surfaces. The design also provides correction for transverse chromatic aberration and distortion, in addition to correcting for the distortion called "smile", the curvature of the slit image formed at each wavelength. These properties render this design capable of superior spectral and spatial performance with size and weight budgets significantly lower than standard configurations. This form of spectrometer design offers the potential for exceptionally compact instrument for differential optical absorption spectroscopy (DOAS) applications from LEO, GEO, HAP or ground-based platforms. The breadboard demonstrator has been shown to offer high throughput and a stable Gaussian line shape with a spectral range from 300 to 450 nm at 0.5 nm resolution, suitable for a number of typical DOAS applications.

  19. Assessment of the performance of a compact concentric spectrometer system for Atmospheric Differential Optical Absorption Spectroscopy

    Directory of Open Access Journals (Sweden)

    C. Whyte

    2009-12-01

    Full Text Available A breadboard demonstrator of a novel UV/VIS grating spectrometer has been developed based upon a concentric arrangement of a spherical meniscus lens, concave spherical mirror and curved diffraction grating suitable for a range of atmospheric remote sensing applications from the ground or space. The spectrometer is compact and provides high optical efficiency and performance benefits over traditional instruments. The concentric design is capable of handling high relative apertures, owing to spherical aberration and comma being near zero at all surfaces. The design also provides correction for transverse chromatic aberration and distortion, in addition to correcting for the distortion called "smile", the curvature of the slit image formed at each wavelength. These properties render this design capable of superior spectral and spatial performance with size and weight budgets significantly lower than standard configurations. This form of spectrometer design offers the potential for exceptionally compact instrument for differential optical absorption spectroscopy (DOAS applications from LEO, GEO, HAP or ground-based platforms. The breadboard demonstrator has been shown to offer high throughput and a stable Gaussian line shape with a spectral range from 300 to 450 nm at 0.5 nm resolution, suitable for a number of typical DOAS applications.

  20. Evaluation of the bioavailability of major withanolides of Withania somnifera using an in vitro absorption model system.

    Science.gov (United States)

    Devkar, Santosh T; Kandhare, Amit D; Sloley, Brian D; Jagtap, Suresh D; Lin, James; Tam, Yun K; Katyare, Surendra S; Bodhankar, Subhash L; Hegde, Mahabaleshwar V

    2015-01-01

    Withania somnifera (L.) Dunal, shows several pharmacological properties which are attributed mainly to the withanolides present in the root. The efficacy of medicinally active withanolides constituents depends on the absorption and transportation through the intestinal epithelium. We examined these characteristics by employing the Sino-Veda Madin-Darby canine kidney cells culture system, which under in vitro condition shows the absorption characteristics similar to the human intestinal epithelium. Thus, the aim of the present investigation was to assess the bioavailability of individual withanolides. Withanolides were diluted in Hank's buffered saline at a concentration of 2 μg/ml were tested for permeability studies carried out for 1 h duration. Permeability was measured in terms of efflux pump (P eff) in cm/s. P eff values of withanolide A (WN A), withanone (WNN), 1,2-deoxywithastramonolide (1,2 DWM), withanolide B (WN B), withanoside IV-V (WS IV-V), and withaferin A were 4.05 × 10(-5), 2.06 × 10(-5), 1.97 × 10(-5), 1.80 × 10(-5), 3.19 × 10(-6), 3.03 × 10(-6) and 3.30 × 10(-7) respectively. In conclusion, the nonpolar and low molecular weight compounds (WN A, WNN, 1,2 DWM, and WN B) were highly permeable. As against this, the glycosylated and polar WS IV and WS V showed low permeability. Surprisingly and paradoxically, the highly biologically active withaferin A was completely impermeable, suggesting that further studies possibly using human epithelial colorectal adenocarcinoma (Caco-2) cells may be needed to delineate the absorption characteristics of withanolides, especially withaferin A.

  1. Mechanism of enhanced oral absorption of morin by phospholipid complex based self-nanoemulsifying drug delivery system.

    Science.gov (United States)

    Zhang, Jinjie; Li, Jianbo; Ju, Yuan; Fu, Yao; Gong, Tao; Zhang, Zhirong

    2015-02-02

    Phospholipid complex (PLC) based self-nanoemulsifying drug delivery system (PLC-SNEDDS) has been developed for efficient delivery of drugs with poor solubility and low permeability. In the present study, a BCS class IV drug and a P-glycoprotein (P-gp) substrate, morin, was selected as the model drug to elucidate the oral absorption mechanism of PLC-SNEDDS. PLC-SNEDDS was superior to PLC in protecting morin from degradation by intestinal enzymes in vitro. In situ perfusion study showed increased intestinal permeability by PLC was duodenum-specific. In contrast, PLC-SNEDDS increased morin permeability in all intestinal segments and induced a change in the main absorption site of morin from colon to ileum. Moreover, ileum conducted the lymphatic transport of PLC-SNEDDS, which was proven by microscopic intestinal visualization of Nile red labeled PLC-SNEDDS and lymph fluids in vivo. Low cytotoxicity and increased Caco-2 cell uptake suggested a safe and efficient delivery of PLC-SNEDDS. The increased membrane fluidity and disrupted actin filaments were closely associated with the increased cell uptake of PLC-SNEDDS. PLC-SNEDDS could be internalized into enterocytes as an intact form in a cholesterol-dependent manner via clathrin-mediated endocytosis and macropinocytosis. The enhanced oral absorption of morin was attributed to the P-gp inhibition by Cremophor RH and the intact internalization of M-PLC-SNEDDS into Caco-2 cells bypassing P-gp recognition. Our findings thus provide new insights into the development of novel nanoemulsions for poorly absorbed drugs.

  2. Absorption Spectrum and Density of States of Square, Rectangular, and Triangular Frenkel Exciton Systems with Gaussian Diagonal Disorder

    Directory of Open Access Journals (Sweden)

    Ibrahim Avgin

    2017-01-01

    Full Text Available Using the coherent potential approximation, we investigate the effects of disorder on the optical absorption and the density of states of Frenkel exciton systems on square, rectangular, and triangular lattices with nearest-neighbor interactions and a Gaussian distribution of transition energies. The analysis is based on an elliptic integral approach that gives results over the entire spectrum. The results for the square lattice are in good agreement with the finite-array calculations of Schreiber and Toyozawa. Our findings suggest that the coherent potential approximation can be useful in interpreting the optical properties of two-dimensional systems with dominant nearest-neighbor interactions and Gaussian diagonal disorder provided the optically active states are Frenkel excitons.

  3. Demonstration of an on-site PAFC cogeneration system with waste heat utilization by a new gas absorption chiller

    Energy Technology Data Exchange (ETDEWEB)

    Urata, Tatsuo [Tokyo Gas Company, LTD, Tokyo (Japan)

    1996-12-31

    Analysis and cost reduction of fuel cells is being promoted to achieve commercial on-site phosphoric acid fuel cells (on-site FC). However, for such cells to be effectively utilized, a cogeneration system designed to use the heat generated must be developed at low cost. Room heating and hot-water supply are the most simple and efficient uses of the waste heat of fuel cells. However, due to the short room-heating period of about 4 months in most areas in Japan, the sites having demand for waste heat of fuel cells throughout the year will be limited to hotels and hospitals Tokyo Gas has therefore been developing an on-site FC and the technology to utilize tile waste heat of fuel cells for room cooling by means of an absorption refrigerator. The paper describes the results of fuel cell cogeneration tests conducted on a double effect gas absorption chiller heater with auxiliary waste heat recovery (WGAR) that Tokyo Gas developed in its Energy Technology Research Laboratory.

  4. Detection of gastrointestinal cancer by elastic scattering and absorption spectroscopies with the Los Alamos Optical Biopsy System

    Energy Technology Data Exchange (ETDEWEB)

    Mourant, J.R.; Boyer, J.; Johnson, T.M.; Lacey, J.; Bigio, I.J. [Los Alamos National Lab., NM (United States); Bohorfoush, A. [Wisconsin Medical School, Milwaukee, WI (United States). Dept. of Gastroenterology; Mellow, M. [Univ. of Oklahoma Medical School, Oklahoma City, OK (United States). Dept. of Gastroenterology

    1995-03-01

    The Los Alamos National Laboratory has continued the development of the Optical Biopsy System (OBS) for noninvasive, real-time in situ diagnosis of tissue pathologies. In proceedings of earlier SPIE conferences we reported on clinical measurements in the bladder, and we report here on recent results of clinical tests in the gastrointestinal tract. With the OBS, tissue pathologies are detected/diagnosed using spectral measurements of the elastic optical transport properties (scattering and absorption) of the tissue over a wide range of wavelengths. The use of elastic scattering as the key to optical tissue diagnostics in the OBS is based on the fact that many tissue pathologies, including a majority of cancer forms, exhibit significant architectural changes at the cellular and sub-cellular level. Since the cellular components that cause elastic scattering have dimensions typically on the order of visible to near-IR wavelengths, the elastic (Mie) scattering properties will be wavelength dependent. Thus, morphology and size changes can be expected to cause significant changes m an optical signature that is derived from the wavelength-dependence of elastic scattering. Additionally, the optical geometry of the OBS beneficially enhances its sensitivity for measuring absorption bands. The OBS employs a small fiber-optic probe that is amenable to use with any endoscope or catheter, or to direct surface examination, as well as interstitial needle insertion. Data acquistion/display time is <1 second.

  5. In operando observation system for electrochemical reaction by soft X-ray absorption spectroscopy with potential modulation method

    International Nuclear Information System (INIS)

    Nagasaka, Masanari; Kosugi, Nobuhiro; Yuzawa, Hayato; Horigome, Toshio

    2014-01-01

    In order to investigate local structures of electrolytes in electrochemical reactions under the same scan rate as a typical value 100 mV/s in cyclic voltammetry (CV), we have developed an in operando observation system for electrochemical reactions by soft X-ray absorption spectroscopy (XAS) with a potential modulation method. XAS spectra of electrolytes are measured by using a transmission-type liquid flow cell with built-in electrodes. The electrode potential is swept with a scan rate of 100 mV/s at a fixed photon energy, and soft X-ray absorption coefficients at different potentials are measured at the same time. By repeating the potential modulation at each fixed photon energy, it is possible to measure XAS of electrochemical reaction at the same scan rate as in CV. We have demonstrated successful measurement of the Fe L-edge XAS spectra of aqueous iron sulfate solutions and of the change in valence of Fe ions at different potentials in the Fe redox reaction. The mechanism of these Fe redox processes is discussed by correlating the XAS results with those at different scan rates

  6. Comment on resonant absorption

    International Nuclear Information System (INIS)

    Hammerling, P.

    1977-01-01

    An average over angles of incidence of the usual resonant absorption function is presented. This form is appropriate under experimental conditions where the angles of incidence vary greatly and in an unknown manner. For comparison a lens-ellipsoidal mirror illumination system with a known longitudinal aberration is considered. In the latter example the angles of incidence are readily obtained and the resulting resonance absorption function evaluated. The associated fields are calculated in a similar fashion. (author)

  7. Characterization of the EPRI Differential Absorption Lidar (DIAL) System. Final report. [For remote sensing of air pollutants

    Energy Technology Data Exchange (ETDEWEB)

    Baumgartner, R.A.; Depp, J.G.; Evans, W.E.; Grant, W.B.; Hawley, J.G.; March, R.G.; Murray, E.R.; Proctor, E.K.

    1979-12-01

    SRI International designed and constructed a DIfferential Absorption Lidar (DIAL) to provide EPRI with a mobile field system for remote measurements of SO/sub 2/, NO/sub 3/, and O/sub 3/. After field testing the lidar was prepared for the sytem calibration testing where lidar measurements were compared to in situ profiles of SO/sub 2/, NO/sub 2/, and O/sub 3/. This two-week field program determined overall system accuracy and reliability in measuring varying ambient gas concentrations. The lidar was then returned to SRI for detailed subsystem performance evaluations. Improvements were made wherever possible, and the lidar was prepared for further systems tests. Tests were made using an NO/sub 2/ sample chamber to simulate a calibrated NO/sub 2/ plume, and ambient measured NO/sub 2/ concentrations were compared with values from a regional air pollutant monitoring station. Following the local calibration and the systems field tests, SRI evaluated the performance and reliability of the EPRI lidar. Based on that evaluation, SRI undertook a major analysis of possible system improvements. Although the remote measuring capability had been successfully demonstrated in the field program, SRI makes several recommendations for systems improvements which would increase the lidar accuracy and reliability.

  8. Development of the Hybrid Operation Method of a Multi-Geothermal Heat Pump System and Absorption Chiller-Heater

    Directory of Open Access Journals (Sweden)

    Young-Ju Jung

    2015-08-01

    Full Text Available Considerable efforts have been made to reduce the energy consumption of buildings due to the energy crisis, and, the Korean government has supported the use of renewable energy through various grants. Among the possible renewable energy sources, geothermal energy can be used regardless of the outside weather. Therefore, energy consumption can be reduced considerably in summer and winter. Despite the increasing use of renewable energy, the use of renewables has not been operating appropriately. Therefore, this study examined some of the problems of the operation of renewable energy and some possible improvements. The aim of the study is to evaluate a building containing an actual installed multi-geothermal heat pump (Multi-GHP system, in terms of the energy efficiency. In addition, this study evaluated the present control system and the method of complex operation regarding existing heat sources systems and GHP systems through a simulation. The results can be regarded as the result of a hybrid operation method for the improvement of an existing operation. Therefore, the Multi-GHP system energy use of a hybrid operation condition of the Multi-GHP systems and the absorption (ABS chiller-heater system was reduced compared to the operation condition of the Multi-GHP system, and the total energy consumption of the heat source equipment was reduced. The proposed operation plan was evaluated after applying the system to a building. These results showed that the efficient operation of a Multi-GHP hybrid operation method is possible. As a result, the GHP energy use of Multi-GHP systems and the ABS chiller-heater system was reduced by 30% compared to existing operation and the total energy consumption of heat source equipment was reduced by 78%.

  9. Some comments about the comparison between a conventional and a solar powered absorption refrigeration system

    International Nuclear Information System (INIS)

    Corbella, O.D.; Garibotti, C.R.

    1983-08-01

    Two statements about the performance of solar refrigeration systems are discussed. First, concepts of efficiency and coefficient of performance are studied. Second, the influence of inflation and rise of fuel prices are considered, in relation to the comparison between solar and conventional refrigeration systems. (author)

  10. Applications of some microscopic, diffraction and absorption techniques to the study of metal--hydrogen systems

    International Nuclear Information System (INIS)

    Pick, M.A.

    1979-01-01

    Several experimental techniques were reviewed which are used to investigate metal hydrogen systems. The first technique is metallography and optical microscopy. This is a very old technique which was found to be very powerful in the case of metal hydrogen systems. A few examples of such work are shown and the results are discussed

  11. In Vitro-In Vivo Predictive Dissolution-Permeation-Absorption Dynamics of Highly Permeable Drug Extended-Release Tablets via Drug Dissolution/Absorption Simulating System and pH Alteration.

    Science.gov (United States)

    Li, Zi-Qiang; Tian, Shuang; Gu, Hui; Wu, Zeng-Guang; Nyagblordzro, Makafui; Feng, Guo; He, Xin

    2018-05-01

    Each of dissolution and permeation may be a rate-limiting factor in the absorption of oral drug delivery. But the current dissolution test rarely took into consideration of the permeation property. Drug dissolution/absorption simulating system (DDASS) valuably gave an insight into the combination of drug dissolution and permeation processes happening in human gastrointestinal tract. The simulated gastric/intestinal fluid of DDASS was improved in this study to realize the influence of dynamic pH change on the complete oral dosage form. To assess the effectiveness of DDASS, six high-permeability drugs were chosen as model drugs, including theophylline (pK a1  = 3.50, pK a2  = 8.60), diclofenac (pK a  = 4.15), isosorbide 5-mononitrate (pK a  = 7.00), sinomenine (pK a  = 7.98), alfuzosin (pK a  = 8.13), and metoprolol (pK a  = 9.70). A general elution and permeation relationship of their commercially available extended-release tablets was assessed as well as the relationship between the cumulative permeation and the apparent permeability. The correlations between DDASS elution and USP apparatus 2 (USP2) dissolution and also between DDASS permeation and beagle dog absorption were developed to estimate the predictability of DDASS. As a result, the common elution-dissolution relationship was established regardless of some variance in the characteristic behavior between DDASS and USP2 for drugs dependent on the pH for dissolution. Level A in vitro-in vivo correlation between DDASS permeation and dog absorption was developed for drugs with different pKa. The improved DDASS will be a promising tool to provide a screening method on the predictive dissolution-permeation-absorption dynamics of solid drug dosage forms in the early-phase formulation development.

  12. Multitracer study on absorption of radionuclides in atmosphere-plant system

    International Nuclear Information System (INIS)

    Ambe, Shizuko; Shinonaga, Taeko; Watanabe, Tadakazu; Yamaguchi, Isamu

    1996-01-01

    Direct absorption of atmospheric radionuclides by soybean plants was studied using a radioactive multitracer consisting of radionuclides of Sc, Mn, Co, As, Se, Rb, Sr, Y, Eu, Gd, Yb, Hf, Re, and Ir. Soybean seedlings were cultivated at 23degC in a box where multitracer-adsorbed cellulose powders were floating in air. After 28-49 day-cultivation, the plants were harvested and divided into beans (seeds and pods), leaves, stems (inside and outside), and roots. Beans or leaves originating from the same node were collected together. After washing with dilute HCl solution and distilled water, they were dried and then subjected to γ-ray measurement. It was estimated that about 0.2 % of the multitracer was absorbed by the soybean plant, of which 80 % was found in the leaves, and 10 % each in beans and stems. The relative amounts of elements in the beans, leaves, and stems markedly differed depending on the element. Among the elements, Se * was greatly accumulated in the beans, leaves, and stems. Cobalt * , Se * , and Rb * were dominant in the beans, especially in the edible part of seeds. Relative amounts of Mn * , As * , Sr * , and Re * in the seeds were very small. It is noticeable that these nuclides were found in the seeds, though they were not physically exposed to the multitracer-adsorbed cellulose powders during growth. The radioactivities of Sc * , Mn * , Co * , As * , Se * , Rb * , Sr * , Y * , Eu * , Gd * , Yb * , Hf * , Re * , and Ir * were observed for the leaves. Brown leaves accumulated greater amounts of radionuclides than green ones. Main nuclides found in the stem were Sc * , Co * , Se * , Y * , Eu * , Gd * , Yb * , Hf * , and Ir * , a larger part of them on the outside. Trace amounts of Co * , Se * , and Rb * were detected in the roots. Little leakage of the multitracer into the soil was observed. These results indicate that various radionuclides in the atmosphere were directly absorbed through soybean leaves and then transported to the edible part

  13. Narrative absorption

    DEFF Research Database (Denmark)

    Narrative Absorption brings together research from the social sciences and Humanities to solve a number of mysteries: Most of us will have had those moments, of being totally absorbed in a book, a movie, or computer game. Typically we do not have any idea about how we ended up in such a state. No...

  14. Configuration optimization of series flow double-effect water-lithium bromide absorption refrigeration systems by cost minimization

    DEFF Research Database (Denmark)

    Mussati, Sergio F.; Cignitti, Stefano; Mansouri, Seyed Soheil

    2018-01-01

    An optimal process configuration for double-effect water-lithium bromide absorption refrigeration systems with series flow – where the solution is first passed through the high-temperature generator – is obtained by minimization of the total annual cost for a required cooling capacity. To this end......) takes place entirely at the high-temperature zone, and the sizes and operating conditions of the other process units change accordingly in order to meet the problem specification with the minimal total annual cost. This new configuration was obtained for wide ranges of the cooling capacity (150–450 k.......9%, respectively. Most importantly, the obtained optimal solution eliminates the low-temperature solution heat exchanger from the conventional configuration, rendering a new process configuration. The energy integration between the weak and strong lithium bromide solutions (cold and hot streams, respectively...

  15. Optimization study of a single-effect water–lithium bromide absorption refrigeration system powered by flat-plate collector in hot regions

    International Nuclear Information System (INIS)

    Saleh, A.; Mosa, M.

    2014-01-01

    Highlights: • A comprehensive analysis for optimizing solar absorption system in hot region. • The most important parameter to be controlled is hot source temperature. • Ensuring appropriate choice of parameters, COP of absorption unit exceeds 0.8. • Results show that solar cooling systems are promising in hot regions. • The research aims to play a vital role to promote the use of renewable energy. - Abstract: This investigation has been carried out to present a comprehensive analysis for optimizing the operation of solar absorption system in hot regions. To optimize performance of the system, the hot source temperature should be controlled in function of incident solar radiation, chilled and cooling water temperatures. With an appropriate control, these external conditions can be monitored to detect and implement the actual optimization conditions. Adopting typical values encountered in hot regions, the overall system performance takes its optimal value at temperatures between 75 and 80 °C. It was found that in designing or selecting solar collector, selective coating type is necessary to produce hot water with potential around 80–90 °C needed to optimize operation of absorption unit. By ensuring an appropriate choice of components temperatures, COP of absorption unit can exceed the value 0.8. Cooling water temperature above 40 °C reduces significantly the performance of the unit which requires, under conditions of extremely high external temperatures, dimensioning and selection of condensers and absorbers that guarantee values less than this limit

  16. Utilizing Near-IR Tunable Laser Absorption Spectroscopy to Study Detonation and Combustion Systems

    Science.gov (United States)

    2014-03-27

    A Hencken burner, Rotating Detonation Engine ( RDE ), and a detonation tube were studied using a Time-Devision Multiplexed Tunable Diode Laser...for the three systems. Velocity was calculated for the RDE system using the Doppler shift of the spectral lines. To perform the calculations necessary...however, the CH4 flame did not match as well. The exhaust of the RDE was studied at various equivalence ratios using a hydrogen-air mixture (H2-air

  17. Vibration energy absorption in the whole-body system of a tractor operator

    OpenAIRE

    Jan Szczepaniak; Wojciech Tanaś; Jacek Kromulski

    2014-01-01

    Many people are exposed to whole-body vibration (WBV) in their occupational lives, especially drivers of vehicles such as tractor and trucks. The main categories of effects from WBV are perception degraded comfort interference with activities-impaired health and occurrence of motion sickness. Absorbed power is defined as the power dissipated in a mechanical system as a result of an applied force. The vibration-induced injuries or disorders in a substructure of the human system are primari...

  18. A experimental system for the checking of the absorption of E.C.A.G. graphite; Empilement pour le controle du graphite E.C.A.G

    Energy Technology Data Exchange (ETDEWEB)

    Raievski, V; Vidal, R [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1958-07-01

    A system is described for measuring the mean absorption cross section in thermal neutrons of graphite. This system consists of a graphite stack containing a Ra-Be source and a BF3 counter. A cavity in the stack receives the graphite to be studied or the graphite standard. By comparing the counting rates their absorption ratio can be deduced. The measurement is performed on graphite rods which have been machined before being placed in the pile. It provides the possibility of detecting over a batch of 1 ton of graphite, in a single measurement, a difference in absorption of 0.1 milli barn. (author) [French] On decrit un dispositif permettant de mesurer la section efficace moyenne d'absorption en neutrons thermiques du graphite. Ce dispositif est constitue par un empilement de graphite contenant une source de Ra-Be et un compteur a BF3. Une cavite menagee dans l'empilement peut recevoir le graphite a etudier ou le graphite etalon. Par comparaison des taux de comptage, on en deduit leur rapport d'absorption. La mesure est effectuee sur des barres de graphite usinees avant leur mise en place dans la pile. Elle permet de deceler sur un lot de graphite de 1 tonne, en une seule mesure, une difference d'absorption de 0,1 millibarn. (auteur)

  19. Design of mini-multi-gas monitoring system based on IR absorption

    Energy Technology Data Exchange (ETDEWEB)

    Tan, Q.L.; Zhang, W.D.; Xue, C.Y.; Xiong, J.J.; Ma, Y.C.; Wen, F. [Northern University of China, Taiyuan (China)

    2008-07-15

    In this paper, a novel non-dispersive infrared ray (IR) gas detection system is described. Conventional devices typically include several primary components: a broadband source (usually all incandescent filament), a rotating chopper shutter, a narrow-band filter, a sample tube and a detector. But we mainly use file mini-multi-channel detector, electrical modulation means and mini-gas-cell structure. To solve the problems of gas accidents in coal mines, and for family safety that results from using gas, this new IR detection system with integration, miniaturization and non-moving parts has been developed. It is based on the principle that certain gases absorb infrared radiation at specific (and often unique) wavelengths. The infrared detection optics principle used in developing this system is mainly analyzed. The idea of multi-gas detection is introduced and guided through the analysis of the single-gas detection. Through researching the design of cell structure, a cell with integration and miniaturization has been devised. By taking a single-chip microcomputer (SCM) as intelligence handling, the functional block diagram of a gas detection system is designed with the analyzing and devising of its hardware and software system. The way of data transmission on a controller area network (CAN) bus and wireless data transmission mode is explained. This system has reached the technology requirement of lower power consumption, mini-volume, wide measure range, and is able to realize multi-gas detection.

  20. The effects of water absorption on an ester vinyl resin system

    Directory of Open Access Journals (Sweden)

    Ledjane Lima Sobrinho

    2009-09-01

    Full Text Available Derakene is a vinyl ester resin largely employed as matrix for polymeric based composite systems. In this work, the performance of such polymeric system was evaluated considering the effect of hygrothermal aging. The mechanical and thermal properties were examined for the processed material before and after ageing in water at 60 ºC for a maximum period of 64 days. Both analyses indicated the occurrence of post cure of the system after 16 days due to exposition at 60 ºC in water, which was also confirmed by analyses in samples with post cure treatment. Moreover, it was observed plasticizing of resin after 36 and 64 days of ageing. Micro structural and fracture surface analyses were carried out in order to characterize the samples. The appearance of surface voids was also observed.

  1. Förster resonance energy transfer, absorption and emission spectra in multichromophoric systems. II. Hybrid cumulant expansion.

    Science.gov (United States)

    Ma, Jian; Moix, Jeremy; Cao, Jianshu

    2015-03-07

    We develop a hybrid cumulant expansion method to account for the system-bath entanglement in the emission spectrum in the multi-chromophoric Förster transfer rate. In traditional perturbative treatments, the emission spectrum is usually expanded with respect to the system-bath coupling term in both real and imaginary time. This perturbative treatment gives a reliable absorption spectrum, where the bath is Gaussian and only the real-time expansion is involved. For the emission spectrum, the initial state is an entangled state of the system plus bath. Traditional perturbative methods are problematic when the excitations are delocalized and the energy gap is larger than the thermal energy, since the second-order expansion cannot predict the displacement of the bath. In the present method, the real-time dynamics is carried out by using the 2nd-order cumulant expansion method, while the displacement of the bath is treated more accurately by utilizing the exact reduced density matrix of the system. In a sense, the hybrid cumulant expansion is based on a generalized version of linear response theory with entangled initial states.

  2. Modulated Sine Waves for Differential Absorption Measurements Using a CW Laser System

    Science.gov (United States)

    Campbell, Joel F. (Inventor); Lin, Bing (Inventor); Nehrir, Amin R. (Inventor)

    2015-01-01

    A continuous wave Light Detection and Ranging (CW LiDAR) system utilizes two or more laser frequencies and time or range shifted pseudorandom noise (PN) codes to discriminate between the laser frequencies. The performance of these codes can be improved by subtracting out the bias before processing. The CW LiDAR system may be mounted to an artificial satellite orbiting the earth, and the relative strength of the return signal for each frequency can be utilized to determine the concentration of selected gases or other substances in the atmosphere.

  3. Optical monitoring of QSO in the framework of the Gaia space mission

    Science.gov (United States)

    Taris, F.; Damljanovic, G.; Andrei, A.; Klotz, A.; Vachier, F.

    2015-08-01

    The Gaia astrometric mission of the European Space Agency has been launched the 19th December 2013. It will provide an astrometric catalogue of 500 000 extragalactic sources that could be the basis of a new optical reference frame. On the other hand, the current International Celestial Reference Frame (ICRF) is based on the observations of extragalactic sources at radio wavelength. The astrometric coordinates of sources in these two reference systems will have roughly the same uncertainty. It is then mandatory to observe a set of common targets at both optical and radio wavelength to link the ICRF with what could be called the GCRF (Gaia Celestial Reference Frame). We will show in this paper some results obtained with the TJO, Telescopi Juan Oro, from Observatori Astronomic del Montsec in Spain. It also presents some results obtained with the Lomb-Scargle and CLEAN algorithm methods applied to optical magnitude obtained with the TAROT telescopes.

  4. Cell culture models of biological barriers: in vitro test systems for drug absorption and delivery

    National Research Council Canada - National Science Library

    Lehr, Claus-Michael

    2002-01-01

    ... may be reprinted or reproduced or utilized in any form or by any electronic, mechanical, or other means, now known or hereafter invented, including photocopying and recording, or in any information storage or retrieval system, without permission in writing from the publishers. Every effort has been made to ensure that the advice and information in this book is t...

  5. MEMBRANOUS FLOWS IN GAS-LIQUID COLLECTORS-REGENERATORS OF SOLAR ABSORPTIVE SYSTEMS FEATURES

    Directory of Open Access Journals (Sweden)

    Doroshenko А.V.

    2009-12-01

    Full Text Available Article is devoted to the creation of new generation of solar collectors of the gas-liquid type, intended for use in alternative refrigerating and conditioning systems of drying-evaporating type with direct solar regeneration of absorbent. Special attention is given to the study of membranous flows features on inclined surfaces, including questions of such flows stability.

  6. Thermodynamic and economic studies of two new high efficient power-cooling cogeneration systems based on Kalina and absorption refrigeration cycles

    International Nuclear Information System (INIS)

    Rashidi, Jouan; Ifaei, Pouya; Esfahani, Iman Janghorban; Ataei, Abtin; Yoo, Chang Kyoo

    2016-01-01

    Highlights: • Proposing two new power and cooling cogeneration systems based on absorption chillers and Kalina cycles. • Model-based comparison through thermodynamic and economic standpoints. • Investigating sensitivity of system performance and costs to the key parameters. • Reducing total annual costs of the base system up to 8% by cogeneration. • Increasing thermal efficiency up to 4.9% despite of cooling generation. - Abstract: Two new power and cooling cogeneration systems based on Kalina cycle (KC) and absorption refrigeration cycle (AC) are proposed and studied from thermodynamic and economic viewpoints. The first proposed system, Kalina power-cooling cycle (KPCC), combines the refrigerant loop of the water-ammonia absorption chiller, consisting of an evaporator and two throttling valves with the KC. A portion of the KC mass flow enters the evaporator to generate cooling after being condensed in the KPCC system. KPCC is a flexible system adapting power and cooling cogeneration to the demand. The second proposed system, Kalina lithium bromide absorption chiller cycle (KLACC), consists of the KC and a single effect lithium bromide-water absorption chiller (AC_L_i_B_r_-_w_a_t_e_r). The KC subsystem discharges heat to the AC_L_i_B_r_-_w_a_t_e_r desorber before condensing in the condenser. The performance and economic aspects of both proposed systems are analyzed and compared with the stand alone KC. A parametric analysis is conducted to evaluate the sensitivity of efficiencies and the generated power and cooling quantities to the key operating variables. The results showed that, thermal efficiency and total annual costs decreased by 5.6% and 8% for KPCC system but increased 4.9% and 58% for KLACC system, respectively. Since the power-cooling efficiency of KLACC is 42% higher than KPCC it can be applied where the aim is cooling generation without considering economic aspects.

  7. Absorptive products

    International Nuclear Information System (INIS)

    Assarsson, P.G.; King, P.A.

    1976-01-01

    Applications for hydrophile gels produced by the radiation induced cross-linking in aqueous solution of polyethylene oxide and starch, as described in Norwegian patent 133501 (INIS RN 281494), such as sanitary napkins (diapers) and sanitary towels, are discussed. The process itself is also discussed and results, expressed as the percentage of insoluble gel and its absorptive capacity for saline solution as functions of the ratio of polyethylene oxide to starch and the radiation dose, are presented. (JIW)

  8. Unshifted Metastable He I* Mini-broad Absorption Line System in the Narrow-line Type 1 Quasar SDSS J080248.18+551328.9

    Science.gov (United States)

    Ji, Tuo; Zhou, Hongyan; Jiang, Peng; Wang, Tinggui; Ge, Jian; Wang, Huiyuan; Komossa, S.; Hamann, Fred; Zuther, Jens; Liu, Wenjuan; Lu, Honglin; Zuo, Wenwen; Yang, Chenwei; Yuan, Weimin

    2015-02-01

    We report the identification of an unusual absorption-line system in the quasar SDSS J080248.18+551328.9 and present a detailed study of the system, incorporating follow-up optical and near-IR spectroscopy. A few tens of absorption lines are detected, including He I*, Fe II*, and Ni II*, which arise from metastable or excited levels, as well as resonant lines in Mg I, Mg II, Fe II, Mn II, and Ca II. All of the isolated absorption lines show the same profile of width Δv ~ 1500 km s-1 centered at a common redshift as that of the quasar emission lines, such as [O II], [S II], and hydrogen Paschen and Balmer series. With narrow Balmer lines, strong optical Fe II multiplets, and weak [O III] doublets, its emission-line spectrum is typical for that of a narrow-line Seyfert 1 galaxy (NLS1). We have derived reliable measurements of the gas-phase column densities of the absorbing ions/levels. Photoionization modeling indicates that the absorber has a density of n H ~ (1.0-2.5) × 105 cm-3 and a column density of N H ~ (1.0-3.2) × 1021 cm-2 and is located at R ~100-250 pc from the central supermassive black hole. The location of the absorber, the symmetric profile of the absorption lines, and the coincidence of the absorption- and emission-line centroid jointly suggest that the absorption gas originates from the host galaxy and is plausibly accelerated by stellar processes, such as stellar winds and/or supernova explosions. The implications for the detection of such a peculiar absorption-line system in an NLS1 are discussed in the context of coevolution between supermassive black hole growth and host galaxy buildup.

  9. Molecular dynamics simulation of a nanofluidic energy absorption system: effects of the chiral vector of carbon nanotubes.

    Science.gov (United States)

    Ganjiani, Sayed Hossein; Hossein Nezhad, Alireza

    2018-02-14

    A Nanofluidic Energy Absorption System (NEAS) is a novel nanofluidic system with a small volume and weight. In this system, the input mechanical energy is converted to surface tension energy during liquid infiltration in the nanotube. The NEAS is made of a mixture of nanoporous material particles in a functional liquid. In this work, the effects of the chiral vector of a carbon nanotube (CNT) on the performance characteristics of the NEAS are investigated by using molecular dynamics simulation. For this purpose, six CNTs with different diameters for each type of armchair, zigzag and chiral, and several chiral CNTs with different chiral vectors (different values of indices (m,n)) are selected and studied. The results show that in the chiral CNTs, the contact angle shows the hydrophobicity of the CNT, and infiltration pressure is reduced by increasing the values of m and n (increasing the CNT diameter). Contact angle and infiltration pressure are decreased by almost 1.4% and 9% at all diameters, as the type of CNT is changed from chiral to zigzag and then to armchair. Absorbed energy density and efficiency are also decreased by increasing m and n and by changing the type of CNT from chiral to zigzag and then to armchair.

  10. Modeling of intensity-modulated continuous-wave laser absorption spectrometer systems for atmospheric CO(2) column measurements.

    Science.gov (United States)

    Lin, Bing; Ismail, Syed; Wallace Harrison, F; Browell, Edward V; Nehrir, Amin R; Dobler, Jeremy; Moore, Berrien; Refaat, Tamer; Kooi, Susan A

    2013-10-10

    The focus of this study is to model and validate the performance of intensity-modulated continuous-wave (IM-CW) CO(2) laser absorption spectrometer (LAS) systems and their CO(2) column measurements from airborne and satellite platforms. The model accounts for all fundamental physics of the instruments and their related CO(2) measurement environments, and the modeling results are presented statistically from simulation ensembles that include noise sources and uncertainties related to the LAS instruments and the measurement environments. The characteristics of simulated LAS systems are based on existing technologies and their implementation in existing systems. The modeled instruments are specifically assumed to be IM-CW LAS systems such as the Exelis' airborne multifunctional fiber laser lidar (MFLL) operating in the 1.57 μm CO(2) absorption band. Atmospheric effects due to variations in CO(2), solar radiation, and thin clouds, are also included in the model. Model results are shown to agree well with LAS atmospheric CO(2) measurement performance. For example, the relative bias errors of both MFLL simulated and measured CO(2) differential optical depths were found to agree to within a few tenths of a percent when compared to the in situ observations from the flight of 3 August 2011 over Railroad Valley (RRV), Nevada, during the summer 2011 flight campaign. In addition, the horizontal variations in the model CO(2) differential optical depths were also found to be consistent with those from MFLL measurements. In general, the modeled and measured signal-to-noise ratios (SNRs) of the CO(2) column differential optical depths (τd) agreed to within about 30%. Model simulations of a spaceborne IM-CW LAS system in a 390 km dawn/dusk orbit for CO(2) column measurements showed that with a total of 42 W of transmitted power for one offline and two different sideline channels (placed at different locations on the side of the CO(2) absorption line), the accuracy of the

  11. Social absorption capability, systems of innovation and manufactured export response to preferential trade incentives

    DEFF Research Database (Denmark)

    Na-Allah, Abdelrasaq; Muchie, Mammo

    2012-01-01

    In many extant analyses of non-reciprocal system of trade preferences, it is typical to focus on the details of market access value of tarrif concessions as explanation for why export beneficiaries may or may not respond to include very often the role that supply related factors can, and do play...... & Opportunity Act apparel trade incentive is used as a classical illustration of this proposition. It is shown that the comparative efficiency of Lesetho, despite emerging from a relatively weak trade performance potential background, in recording the highest level of export success among beneficiaries...

  12. Effect of Moisture Exchange on Interface Formation in the Repair System Studied by X-ray Absorption

    Directory of Open Access Journals (Sweden)

    Mladena Lukovic

    2015-12-01

    Full Text Available In concrete repair systems, material properties of the repair material and the interface are greatly influenced by the moisture exchange between the repair material and the substrate. If the substrate is dry, it can absorb water from the repair material and reduce its effective water-to-cement ratio (w/c. This further affects the hydration rate of cement based material. In addition to the change in hydration rate, void content at the interface between the two materials is also affected. In this research, the influence of moisture exchange on the void content in the repair system as a function of initial saturation level of the substrate is investigated. Repair systems with varying level of substrate saturation are made. Moisture exchange in these repair systems as a function of time is monitored by the X-ray absorption technique. After a specified curing age (3 d, the internal microstructure of the repair systems was captured by micro-computed X-ray tomography (CT-scanning. From reconstructed images, different phases in the repair system (repair material, substrate, voids can be distinguished. In order to quantify the void content, voids were thresholded and their percentage was calculated. It was found that significantly more voids form when the substrate is dry prior to application of the repair material. Air, initially filling voids and pores of the dry substrate, is being released due to the moisture exchange. As a result, air voids remain entrapped in the repair material close to the interface. These voids are found to form as a continuation of pre-existing surface voids in the substrate. Knowledge about moisture exchange and its effects provides engineers with the basis for recommendations about substrate preconditioning in practice.

  13. Effect of Moisture Exchange on Interface Formation in the Repair System Studied by X-ray Absorption.

    Science.gov (United States)

    Lukovic, Mladena; Ye, Guang

    2015-12-22

    In concrete repair systems, material properties of the repair material and the interface are greatly influenced by the moisture exchange between the repair material and the substrate. If the substrate is dry, it can absorb water from the repair material and reduce its effective water-to-cement ratio (w/c). This further affects the hydration rate of cement based material. In addition to the change in hydration rate, void content at the interface between the two materials is also affected. In this research, the influence of moisture exchange on the void content in the repair system as a function of initial saturation level of the substrate is investigated. Repair systems with varying level of substrate saturation are made. Moisture exchange in these repair systems as a function of time is monitored by the X-ray absorption technique. After a specified curing age (3 d), the internal microstructure of the repair systems was captured by micro-computed X-ray tomography (CT-scanning). From reconstructed images, different phases in the repair system (repair material, substrate, voids) can be distinguished. In order to quantify the void content, voids were thresholded and their percentage was calculated. It was found that significantly more voids form when the substrate is dry prior to application of the repair material. Air, initially filling voids and pores of the dry substrate, is being released due to the moisture exchange. As a result, air voids remain entrapped in the repair material close to the interface. These voids are found to form as a continuation of pre-existing surface voids in the substrate. Knowledge about moisture exchange and its effects provides engineers with the basis for recommendations about substrate preconditioning in practice.

  14. Load Absorption Characteristics of Tyre Production Waste Rubber for Playground Floor Systems

    Directory of Open Access Journals (Sweden)

    Abdul Ghani A.N.

    2014-01-01

    Full Text Available The floor surfaces where slides and swings are placed in parks and playrooms should be soft and thick to ensure that whenever a child falls, the surface can withstand the impact and minimize injuries to the child. Shredded tyres from waste tyres or waste rubber from tyre manufacturing could become beneficial as shock absorber material which can be used as a playground floor. In this study, rubber cubes and rubber pads with 5%, 8% and 10% SBR mixes were prepared for mechanical testing. Two types of floor design surfaces with and without plywood on the surface were assembled for the shock test. Gmax and HIC of this waste rubber flooring system were investigated using the compression test for the rubber cube and the drop test for the rubber pad. The criteria of general protection standards are 200g for optimum acceleration and 1000 for HIC. The Gmax and HIC results indicated that the material and system could ensure a safe fall from up to 1.0m height.

  15. Mathematical modelling of heat absorption capacity of containment spray system in a 700 MWe PHWR

    International Nuclear Information System (INIS)

    Kota, Sampath Bharadwaj; Ali, Seik Mansoor; Balasubramaniyan, V.

    2015-01-01

    This paper presents a mathematical model for estimating the heat removal by containment spray system in the post Loss of Coolant Accident (LOCA) environment. The procedure involves firstly, the calculation of heat removal rates by droplets of spray dispersed in the air-steam mixture by an appropriate direct contact condensation model accounting for the presence of non-condensable gas (air). Parametric influence of droplet size, ambient pressure and temperature on heat flux is brought out. It was found that the heat flux is inversely proportional to the ambient pressure and diameter. A spray module was subsequently developed and incorporated into an in-house containment thermal hydraulics code. The pressure and temperature transients in a 700 MWe PHWR containment building following a Large Break LOCA was obtained using this code. The efficacy of the spray in condensing the steam is shown by comparing the transients with and without the operation of spray system. Parametric studies are also conducted with respect to droplet size and flow rate of water droplet spray. The details of the investigation are presented and discussed in this paper. (author)

  16. Atomic absorption instrument functional description

    International Nuclear Information System (INIS)

    Bystroff, R.I.; Boyle, W.G. Jr.; Barton, G.W. Jr.

    1976-01-01

    This report describes a proposed system for automating atomic absorption analysis. The system consists of two atomic absorption instruments and an automatic sampler that can be attached to either instrument. A computer program controls the sampling and gathers data. The program then uses the data to perform bookkeeping, data processing, and report writing

  17. Recent Advances in Delivery Systems and Therapeutics of Cinnarizine: A Poorly Water Soluble Drug with Absorption Window in Stomach

    Directory of Open Access Journals (Sweden)

    Smita Raghuvanshi

    2014-01-01

    Full Text Available Low solubility causing low dissolution in gastrointestinal tract is the major problem for drugs meant for systemic action after oral administration, like cinnarizine. Pharmaceutical products of cinnarizine are commercialized globally as immediate release preparations presenting low absorption with low and erratic bioavailability. Approaches to enhance bioavailability are widely cited in the literature. An attempt has been made to review the bioavailability complications and clinical therapeutics of poorly water soluble drug: cinnarizine. The interest of writing this paper is to summarize the pharmacokinetic limitations of drug with special focus on strategies to improvise bioavailability along with effectiveness of novel dosage forms to circumvent the obstacle. The paper provides insight to the approaches to overcome low and erratic bioavailability of cinnarizine by cyclodextrin complexes and novel dosage forms: self-nanoemulsifying systems and buoyant microparticulates. Nanoformulations need to systematically explored in future, for their new clinical role in prophylaxis of migraine attacks in children. Clinical reports have affirmed the role of cinnarizine in migraine prophylaxis. Research needs to be dedicated to develop dosage forms for efficacious bioavailability and drug directly to brain.

  18. Modeling and experimental validation of the solar loop for absorption solar cooling system using double-glazed collectors

    International Nuclear Information System (INIS)

    Marc, Olivier; Praene, Jean-Philippe; Bastide, Alain; Lucas, Franck

    2011-01-01

    Solar cooling applied to buildings is without a doubt an interesting alternative for reducing energy consumption in traditional mechanical steam compression air conditioning systems. The study of these systems should have a closely purely fundamental approach including the development of numerical models in order to predict the overall installation performance. The final objective is to estimate cooling capacity, power consumption, and overall installation performance with relation to outside factors (solar irradiation, outside temperature...). The first stage in this work consists of estimating the primary energy produced by the solar collector field. The estimation of this primary energy is crucial to ensure the evaluation of the cooling capacity and therefore the cooling distribution and thermal comfort in the building. Indeed, the absorption chiller performance is directly related to its heat source. This study presents dynamic models for double glazing solar collectors and compares the results of the simulation with experimental results taken from our test bench (two collectors). In the second part, we present an extensive collector field model (36 collectors) from our solar cooling installation at The University Institute of Technology in St Pierre, Reunion Island as well as our stratified tank storage model. A comparison of the simulation results with real scale solar experimental data taken from our installation enables validation of the double glazing solar collector and stratified tank dynamic models.

  19. Sulfur K-edge absorption spectroscopy on selected biological systems; Schwefel-K-Kanten-Absorptionsspektroskopie an ausgewaehlten biologischen Systemen

    Energy Technology Data Exchange (ETDEWEB)

    Lichtenberg, Henning

    2008-07-15

    Sulfur is an essential element in organisms. In this thesis investigations of sulfur compounds in selected biological systems by XANES (X-ray Absorption Near Edge Structure) spectroscopy are reported. XANES spectroscopy at the sulfur K-edge provides an excellent tool to gain information about the local environments of sulfur atoms in intact biological samples - no extraction processes are required. Spatially resolved measurements using a Kirkpatrick-Baez mirror focusing system were carried out to investigate the infection of wheat leaves by rust fungi. The results give information about changes in the sulfur metabolism of the host induced by the parasite and about the extension of the infection into visibly uninfected plant tissue. Furthermore, XANES spectra of microbial mats from sulfidic caves were measured. These mats are dominated by microbial groups involved in cycling sulfur. Additionally, the influence of sulfate deprivation and H{sub 2}S exposure on sulfur compounds in onion was investigated. To gain an insight into the thermal degradation of organic material the influence of roasting of sulfur compounds in coffee beans was studied. (orig.)

  20. Comparative studies of H absorption/desorption kinetics and evaporation of liquid lithium in different porous systems and free surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Oyarzabal, E., E-mail: eider.oyarzabal@externos.ciemat.es [Ass. Euratom-Ciemat, Av. Complutense 22, 28040 Madrid (Spain); Calle de Guzmán el Bueno, 133, 28003 Madrid (Spain); Martín-Rojo, A.B. [Ass. Euratom-Ciemat, Av. Complutense 22, 28040 Madrid (Spain); Calle de Guzmán el Bueno, 133, 28003 Madrid (Spain); Tabarés, F.L. [Ass. Euratom-Ciemat, Av. Complutense 22, 28040 Madrid (Spain)

    2017-04-15

    In the present work, a study of the two most relevant properties of liquid lithium with respect to its suitability as a Plasma Facing Component (PFC) element in a Reactor, namely, its evaporation rate and the uptake/release of hydrogen, eventually leading to the formation of a stable hydride was carried out for Li in different porous systems and Li as a free surface. These properties were characterized in a temperature range of 200–500 °C. The H{sub 2} absorption kinetics at low pressure (<1torr) were measured for the different studied porous systems and then outgassed. Particle balance and chemical analysis were used to assess the retention properties of lithium for each case. Thermal Desorption Spectroscopy (TDS) analysis was used for the assessment of possible hydride formation. Evaporation rates were determined by using a Quartz Microbalance (QMB). A significant reduction of the evaporation rate was observed when Li was trapped in a microstructure of sintered stainless steel with a characteristic porous size of 5–10 μm. On the other hand, a negligible rate of H{sub 2} uptake was found at temperatures above 500 °C in all cases.

  1. Absorption of carbon dioxide and isotope exchange rate of carbon in a reaction system between carbon dioxide and carbamic acid

    International Nuclear Information System (INIS)

    Takeshita, Kenji; Kitamoto, Asashi

    1985-01-01

    The performance of isotope separation of carbon-13 by chemical exchange between carbon dioxide and carbamic acid was studied. The working fluid used in the study was a solution of DNBA, (C 4 H 9 ) 2 NH and n-octane mixture. Factors related to the isotope exchange rate were measured, such as the absorption rate of carbon dioxide into the solution of DNBA and n-octane, the isotope exchange rate and the separation factor in the reaction between CO 2 and carbamic acid. The absorption of CO 2 into the working fluid was the sum of chemical absorption by DNBA and physical absorption by n-octane. The absorption of carbon dioxide into the working fluid was negligible at temperatures over 90 0 C, but increased gradually at lower temperatures. Carbon dioxide was absorbed into DNBA by chemical absorption, and DNBA was converted to carbamic acid by the reaction. The reaction for synthesis and decomposition of carbamic acid was reversible. The separation factor in equilibrium reached a large value at lower temperatures. The isotope exchange rate between gas and liquid was proportional to the product of the concentration of carbamic acid and the concentration of CO 2 by physical absorption. The isotope separation of carbon by chemical exchange reaction is better operated under the conditions of lower temperature and higher pressure. (author)

  2. H2S absorption and desorption system for a heavy water production plant (Gird ler-Sulphide method)

    International Nuclear Information System (INIS)

    Diaz, F.; Duran, O.

    1987-01-01

    A computational design for the principal equipment involved in the absorption and desorption sections of a heavy water production plant (Girdler-sulphide method) is described. the programs were developed in FORTRAN. A detailled description of transport equations for the desorption tower, which are applicable for the absorption one is included. The optimization criteria used for the equipment design were mainly economic; the results were obtained under the optimal conditions for the towers. The programs may be used in the long term, for the simulation of the absorption and desorption sections together with the isotopic exchange sectionts (author)

  3. Wide-area remote-sensing system of pollution and gas dispersal by near-infrared absorption based on low-loss optical fiber network

    Science.gov (United States)

    Inaba, H.

    1986-01-01

    An all optical remote sensing system utilizing long distance, ultralow loss optical fiber networks is studied and discussed for near infrared absorption measurements of combustible and/or explosive gases such as CH4 and C3H8 in our environment, including experimental results achieved in a diameter more than 20 km. The use of a near infrared wavelength range is emphasized.

  4. Extrapolation of systemic bioavailability assessing skin absorption and epidermal and hepatic metabolism of aromatic amine hair dyes in vitro.

    Science.gov (United States)

    Manwaring, John; Rothe, Helga; Obringer, Cindy; Foltz, David J; Baker, Timothy R; Troutman, John A; Hewitt, Nicola J; Goebel, Carsten

    2015-09-01

    Approaches to assess the role of absorption, metabolism and excretion of cosmetic ingredients that are based on the integration of different in vitro data are important for their safety assessment, specifically as it offers an opportunity to refine that safety assessment. In order to estimate systemic exposure (AUC) to aromatic amine hair dyes following typical product application conditions, skin penetration and epidermal and systemic metabolic conversion of the parent compound was assessed in human skin explants and human keratinocyte (HaCaT) and hepatocyte cultures. To estimate the amount of the aromatic amine that can reach the general circulation unchanged after passage through the skin the following toxicokinetically relevant parameters were applied: a) Michaelis-Menten kinetics to quantify the epidermal metabolism; b) the estimated keratinocyte cell abundance in the viable epidermis; c) the skin penetration rate; d) the calculated Mean Residence Time in the viable epidermis; e) the viable epidermis thickness and f) the skin permeability coefficient. In a next step, in vitro hepatocyte Km and Vmax values and whole liver mass and cell abundance were used to calculate the scaled intrinsic clearance, which was combined with liver blood flow and fraction of compound unbound in the blood to give hepatic clearance. The systemic exposure in the general circulation (AUC) was extrapolated using internal dose and hepatic clearance, and Cmax was extrapolated (conservative overestimation) using internal dose and volume of distribution, indicating that appropriate toxicokinetic information can be generated based solely on in vitro data. For the hair dye, p-phenylenediamine, these data were found to be in the same order of magnitude as those published for human volunteers. Copyright © 2015. Published by Elsevier Inc.

  5. Thermodynamic modelling and parametric study of a low temperature vapour compression-absorption system based on modified Gouy-Stodola equation

    International Nuclear Information System (INIS)

    Jain, Vaibhav; Sachdeva, Gulshan; Kachhwaha, S.S.

    2015-01-01

    Present paper thermodynamically analyses a VCAS (vapour compression-absorption system) with carbon dioxide (compression section) and ammonia-water (absorption section) as refrigerants and determines the optimal condensing temperature of cascade condenser using modified Gouy-Stodola equation. The optimum cascade condenser temperature is found to be −13 °C for 175 kW refrigeration capacity at an evaporator temperature of −45 °C and condenser temperature of 35 °C. The optimum cascade condenser temperature maximises the overall COP, rational efficiency and minimises the total irreversibility rate of the VCAS system. The value of optimum condensing temperature and its corresponding maximum COP, and minimum irreversibility rate are discussed for a wide range of operating conditions. Further, a comparative study of TSVCS (two stage vapour compression system) used for low temperature refrigeration applications with VCAS shows that at design point, primary energy consumption is reduced by 60.6% and electrical COP is improved by 153.6% in VCAS as compared to conventional TSVCS. But the total irreversibility rate of VCAS is 38.4% higher than the TSVCS due to the use of low grade energy in vapour absorption system and hence the rational efficiency of VCAS is 14% low. - Highlights: • Optimum cascade condenser temperature with modified Gouy-Stodola law is analysed. • It maximises COP, rational efficiency and minimises total irreversibility. • 60.6% of primary energy is saved by cascaded absorption system. • Electrical COP is improved by 153.6% with cascaded absorption system

  6. Investigation of structural and hydrogen absorption properties in the LaNi5-xPtx-H2 system

    International Nuclear Information System (INIS)

    Joubert, J.-M.; Charton, J.; Percheron-Guegan, A.

    2003-01-01

    The substitution of nickel by platinum in the binary LaNi 5 compound (CaCu 5 structure type, a=5.019(1) A, c=3.981(1) A, space group P6/mmm) and its effect on the hydrogenation properties was studied. The phase LaNi 5-x Pt x has a homogeneity domain ranging from x=0 to 5. For x 3. Contrary to what is observed in other systems, the hydrogen absorption plateau pressure was found to increase as a function of the cell volume. Powder neutron diffraction experiments were conducted for two deuterated compounds with x=0.25 and 0.75. Deuterium partial ordering occurs in the case of x=0.25 leading to a symmetry decrease to the space group P6mm (LaNi 4.75 Pt 0.25 D 5.23 , a=4.225(1) A, c=5.357(1) A, Z=1, R Bragg =3.3%). For x=0.75, an orthorhombic superstructure based on the CaCu 5 -type lattice was found (LaNi 4.25 Pt 0.75 D 2.61 , a orth =√3a hex =9.089(1) A, b orth =b hex =5.272(1) A, c orth =2c hex =8.145(1) A, Z=4, SG Ibam, R Bragg =6.1%)

  7. Absorption systems at z ˜ 2 as a probe of the circum galactic medium: a probabilistic approach

    Science.gov (United States)

    Mongardi, C.; Viel, M.; D'Odorico, V.; Kim, T.-S.; Barai, P.; Murante, G.; Monaco, P.

    2018-05-01

    We characterize the properties of the intergalactic medium (IGM) around a sample of galaxies extracted from state-of-the-art hydrodynamical simulations of structure formation in a cosmological volume of 25 Mpc comoving at z ˜ 2. The simulations are based on two different sub-resolution schemes for star formation and supernova feedback: the MUlti-Phase Particle Integrator (MUPPI) scheme and the Effective Model. We develop a quantitative and probabilistic analysis based on the apparent optical depth method of the properties of the absorbers as a function of impact parameter from their nearby galaxies: in such a way we probe different environments from circumgalactic medium (CGM) to low density filaments. Absorbers' properties are then compared with a spectroscopic observational data set obtained from high resolution quasar spectra. Our main focus is on the NCIV - NHI relation around simulated galaxies: the results obtained with MUPPI and the Effective model are remarkably similar, with small differences only confined to regions at impact parameters b = [1 - 3] × rvir. Using {C IV} as a tracer of the metallicity, we obtain evidence that the observed metal absorption systems have the highest probability to be confined in a region of 150-400 kpc around galaxies. Near-filament environments have instead metallicities too low to be probed by present-day telescopes, but could be probed by future spectroscopical studies. Finally we compute {C IV} covering fractions which are in agreement with observational data.

  8. A possible connection between the spin temperature of damped Lyman α absorption systems and star formation history

    Science.gov (United States)

    Curran, S. J.

    2017-09-01

    We present a comprehensive analysis of the spin temperature/covering factor degeneracy, Tspin/f, in damped Lyman α absorption systems. By normalizing the upper limits and including these via a survival analysis, there is, as previously claimed, an apparent increase in Tspin/f with redshift at zabs ≳ 1. However, when we account for the geometry effects of an expanding Universe, neglected by the previous studies, this increase in Tspin at zabs ≳ 1 is preceded by a decrease at zabs ≲ 1. Using high resolution radio images of the background continuum sources, we can transform the Tspin/f degeneracy to T_spin/d_abs^{ 2}, where dabs is the projected linear size of the absorber. Again, there is no overall increase with redshift, although a dip at zabs ≈ 2 persists. Furthermore, we find d_abs^{ 2}/T_spin to follow a similar variation with redshift as the star formation rate, ψ*. This suggests that, although the total hydrogen column density, N_{H I}, shows little relation to ψ*, the fraction of the cold neutral medium, \\int τ_obs dv/N_{H I}, may. Therefore, further efforts to link the neutral gas with the star formation history should also consider the cool component of the gas.

  9. The Effect of Digestion and Drug Load on Halofantrine Absorption from Self-nanoemulsifying Drug Delivery System (SNEDDS)

    DEFF Research Database (Denmark)

    Michaelsen, Maria Hotoft; Wasan, Kishor M.; Sivak, Olena

    2016-01-01

    A super-saturated self-nanoemulsifying drug delivery system (super-SNEDDS), containing the poorly water-soluble drug halofantrine (Hf) at 150% of equilibrium solubility (Seq), was compared in vitro and in vivo with a conventional SNEDDS (75% of Seq) with respect to bioavailability and digestibility....... Further, the effect of digestion on oral absorption of Hf from SNEDDS and super-SNEDDS was assessed by incorporation of the lipase inhibitor tetrahydrolipstatin (orlistat) into the SNEDDS. The SNEDDS contained soybean oil/Maisine 34-I (1:1), Kolliphor RH40, and ethanol at a ratio of 55:35:10, w/w percent....... For the dynamic in vitro lipolysis, the precipitation of Hf at 60 min was significantly larger for the super-SNEDDS (66.8 ± 16.4%) than for the SNEDDS (18.5 ± 9.2%). The inhibition of the in vitro digestion by orlistat (1% (w/w)) lowered drug precipitation significantly for both the super-SNEDDS (36.8 ± 1...

  10. Experimental diagnosis of the influence of operational variables on the performance of a solar absorption cooling system

    International Nuclear Information System (INIS)

    Venegas, M.; Rodriguez-Hidalgo, M.C.; Salgado, R.; Lecuona, A.; Rodriguez, P.; Gutierrez, G.

    2011-01-01

    This paper presents the analysis of the performance of a solar cooling facility along one summer season using a commercial single-effect water-lithium bromide absorption chiller aiming at domestic applications. The facility works only with solar energy using flat plate collectors and it is located at Universidad Carlos III de Madrid, Spain. The statistical analysis performed with the gathered data shows the influence of five daily operational variables on the system performance. These variables are solar energy received along the day (H) and the average values, along the operating period of the solar cooling facility (from sunrise to the end of the cold-water production), of the ambient temperature (T -bar ), the wind velocity magnitude (V), the wind direction (θ) and the relative humidity (RH). First order correlation functions are given. The analysis of the data allows concluding that the most influential variables on the daily cooling energy produced and the daily averaged solar COP are H, V and θ. The period length of cold-water production is determined mainly by H and T -bar .

  11. Experimental diagnosis of the influence of operational variables on the performance of a solar absorption cooling system

    Energy Technology Data Exchange (ETDEWEB)

    Venegas, M.; Rodriguez-Hidalgo, M.C.; Lecuona, A.; Rodriguez, P.; Gutierrez, G. [Dpto. Ingenieria Termica y de Fluidos, Universidad Carlos III de Madrid, Avda. Universidad 30, 28911 Leganes, Madrid (Spain); Salgado, R. [Dpto. Ingenieria Mecanica, Universidad Interamericana de Puerto Rico, Recinto de Bayamon, 500 Carretera Dr. John Will Harris Bayamon, PR 00957-6257 (United States)

    2011-04-15

    This paper presents the analysis of the performance of a solar cooling facility along one summer season using a commercial single-effect water-lithium bromide absorption chiller aiming at domestic applications. The facility works only with solar energy using flat plate collectors and it is located at Universidad Carlos III de Madrid, Spain. The statistical analysis performed with the gathered data shows the influence of five daily operational variables on the system performance. These variables are solar energy received along the day (H) and the average values, along the operating period of the solar cooling facility (from sunrise to the end of the cold-water production), of the ambient temperature (anti T), the wind velocity magnitude (V), the wind direction ({theta}) and the relative humidity (RH). First order correlation functions are given. The analysis of the data allows concluding that the most influential variables on the daily cooling energy produced and the daily averaged solar COP are H, V and {theta}. The period length of cold-water production is determined mainly by H and anti T. (author)

  12. Radionuclide Absorption Demonstration System

    Data.gov (United States)

    National Aeronautics and Space Administration — After a nuclear thermal rocket (NTR) is test fired, the engine’s reactor is operated in a cool-down mode during which radioactive exhaust by-products continue to be...

  13. Structural determination of individual chemical species in a mixed system by iterative transformation factor analysis-based X-ray absorption spectroscopy combined with UV-visible absorption and quantum chemical calculation.

    Science.gov (United States)

    Ikeda, Atsushi; Hennig, Christoph; Rossberg, André; Tsushima, Satoru; Scheinost, Andreas C; Bernhard, Gert

    2008-02-15

    A multitechnique approach using extended X-ray absorption fine structure (EXAFS) spectroscopy based on iterative transformation factor analysis (ITFA), UV-visible absorption spectroscopy, and density functional theory (DFT) calculations has been performed in order to investigate the speciation of uranium(VI) nitrate species in acetonitrile and to identify the complex structure of individual species in the system. UV-visible spectral titration suggests that there are four different species in the system, that is, pure solvated species, mono-, di-, and trinitrate species. The pure EXAFS spectra of these individual species are extracted by ITFA from the measured spectral mixtures on the basis of the speciation distribution profile calculated from the UV-visible data. Data analysis of the extracted EXAFS spectra, with the help of DFT calculations, reveals the most probable complex structures of the individual species. The pure solvated species corresponds to a uranyl hydrate complex with an equatorial coordination number (CNeq) of 5, [UO2(H2O)5]2+. Nitrate ions tend to coordinate to the uranyl(VI) ion in a bidentate fashion rather than a unidentate one in acetonitrile for all the nitrate species. The mononitrate species forms the complex of [UO2(H2O)3NO3]+ with a CNeq value of 5, while the di- and trinitrate species have a CNeq value of 6, corresponding to [UO2(H2O)2(NO3)2]0 (D2h) and [UO2(NO3)3]- (D3h), respectively.

  14. Gamma–Gamma Absorption in the γ-ray Binary System PSR B1259-63/LS 2883

    Energy Technology Data Exchange (ETDEWEB)

    Sushch, Iurii [Centre for Space Research, North-West University, 2520 Potcheftroom (South Africa); Van Soelen, Brian, E-mail: iurii.sushch@desy.de, E-mail: vansoelenb@ufs.ac.za [Department of Physics, University of the Free State, 9300 Bloemfontein (South Africa)

    2017-03-10

    The observed TeV light curve from the γ -ray binary PSR B1259-63/LS 2883 shows a decrease in the flux at periastron that has not been fully explained by emission mechanisms alone. This observed decrease can, however, be explained by γγ absorption due to the stellar and disk photons. We calculate the γγ absorption in PSR B1259-63/LS 2883 taking into account photons from both the circumstellar disk and star, assuming that the γ -rays originate at the position of the pulsar. The γγ absorption due to the circumstellar disk photons produces a ≈14% decrease in the flux, and there is a total decrease of ≈52% (>1 TeV) within a few days before periastron, accompanied by a hardening of the γ -ray photon index. While the γγ absorption alone is not sufficient to explain the full complexity of the H.E.S.S. γ -ray light curve, it results in a significant decrease in the predicted flux, which is coincident with the observed decrease. In addition, we have calculated an upper limit on the γγ absorption, assuming that the emission is produced at the apex of the bow shock. Future observations with CTA during the 2021 periastron passage may be able to confine the location of the emission based on the degree of γγ absorption, as well as measure the hardening of the spectrum around periastron.

  15. Comparison of two methods for blood lead analysis in cattle: graphite-furnace atomic absorption spectrometry and LeadCare(R) II system.

    Science.gov (United States)

    Bischoff, Karyn; Gaskill, Cynthia; Erb, Hollis N; Ebel, Joseph G; Hillebrandt, Joseph

    2010-09-01

    The current study compared the LeadCare(R) II test kit system with graphite-furnace atomic absorption spectrometry for blood lead (Pb) analysis in 56 cattle accidentally exposed to Pb in the field. Blood Pb concentrations were determined by LeadCare II within 4 hr of collection and after 72 hr of refrigeration. Blood Pb concentrations were determined by atomic absorption spectrometry, and samples that were coagulated (n = 12) were homogenized before analysis. There was strong rank correlation (R(2) = 0.96) between atomic absorption and LeadCare II (within 4 hr of collection), and a conversion formula was determined for values within the observed range (3-91 mcg/dl, although few had values >40 mcg/dl). Median and mean blood pb concentrations for atomic absorption were 7.7 and 15.9 mcg/dl, respectively; for LeadCare II, medians were 5.2 mcg/dl at 4 hr and 4.9 mcg/dl at 72 hr, and means were 12.4 and 11.7, respectively. LeadCare II results at 4 hr strongly correlated with 72 hr results (R(2) = 0.96), but results at 72 hr were lower (P atomic absorption. Although there have been several articles that compared LeadCare with other analytical techniques, all were for the original system, not LeadCare II. The present study indicated that LeadCare II results correlated well with atomic absorption over a wide range of blood Pb concentrations and that refrigerating samples for up to 72 hr before LeadCare II analysis was acceptable for clinical purposes.

  16. Enabling the Distributed Generation Market of High Temperature Fuel Cell and Absorption Chiller Systems to Support Critical and Commercial Loads

    Science.gov (United States)

    DiMola, Ashley M.

    Buildings account for over 18% of the world's anthropogenic Greenhouse Gas (GHG) emissions. As a result, a technology that can offset GHG emissions associated with buildings has the potential to save over 9 Giga-tons of GHG emissions per year. High temperature fuel cell and absorption chiller (HTFC/AC) technology offers a relatively low-carbon option for meeting cooling and electric loads for buildings while producing almost no criteria pollutants. GHG emissions in the state of California would decrease by 7.48 million metric tons per year if every commercial building in the State used HTFC/AC technology to meet its power and cooling requirements. In order to realize the benefits of HTFC/AC technology on a wide scale, the distributed generation market needs to be exposed to the technology and informed of its economic viability and real-world potential. This work characterizes the economics associated with HTFC/AC technology using select scenarios that are representative of realistic applications. The financial impacts of various input factors are evaluated and the HTFC/AC simulations are compared to the economics of traditional building utilities. It is shown that, in addition to the emissions reductions derived from the systems, HTFC/AC technology is financially preferable in all of the scenarios evaluated. This work also presents the design of a showcase environment, centered on a beta-test application, that presents (1) system operating data gathered using a custom data acquisition module, and (2) HTFC/AC technology in a clear and approachable manner in order to serve the target audience of market stakeholders.

  17. Extrapolation of systemic bioavailability assessing skin absorption and epidermal and hepatic metabolism of aromatic amine hair dyes in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Manwaring, John, E-mail: manwaring.jd@pg.com [Procter & Gamble Inc., Mason Business Center, Mason, OH 45040 (United States); Rothe, Helga [Procter & Gamble Service GmbH, Sulzbacher Str. 40, 65823 Schwalbach am Taunus (Germany); Obringer, Cindy; Foltz, David J.; Baker, Timothy R.; Troutman, John A. [Procter & Gamble Inc., Mason Business Center, Mason, OH 45040 (United States); Hewitt, Nicola J. [SWS, Erzhausen (Germany); Goebel, Carsten [Procter & Gamble Service GmbH, Sulzbacher Str. 40, 65823 Schwalbach am Taunus (Germany)

    2015-09-01

    Approaches to assess the role of absorption, metabolism and excretion of cosmetic ingredients that are based on the integration of different in vitro data are important for their safety assessment, specifically as it offers an opportunity to refine that safety assessment. In order to estimate systemic exposure (AUC) to aromatic amine hair dyes following typical product application conditions, skin penetration and epidermal and systemic metabolic conversion of the parent compound was assessed in human skin explants and human keratinocyte (HaCaT) and hepatocyte cultures. To estimate the amount of the aromatic amine that can reach the general circulation unchanged after passage through the skin the following toxicokinetically relevant parameters were applied: a) Michaelis–Menten kinetics to quantify the epidermal metabolism; b) the estimated keratinocyte cell abundance in the viable epidermis; c) the skin penetration rate; d) the calculated Mean Residence Time in the viable epidermis; e) the viable epidermis thickness and f) the skin permeability coefficient. In a next step, in vitro hepatocyte K{sub m} and V{sub max} values and whole liver mass and cell abundance were used to calculate the scaled intrinsic clearance, which was combined with liver blood flow and fraction of compound unbound in the blood to give hepatic clearance. The systemic exposure in the general circulation (AUC) was extrapolated using internal dose and hepatic clearance, and C{sub max} was extrapolated (conservative overestimation) using internal dose and volume of distribution, indicating that appropriate toxicokinetic information can be generated based solely on in vitro data. For the hair dye, p-phenylenediamine, these data were found to be in the same order of magnitude as those published for human volunteers. - Highlights: • An entirely in silico/in vitro approach to predict in vivo exposure to dermally applied hair dyes • Skin penetration and epidermal conversion assessed in human

  18. Extrapolation of systemic bioavailability assessing skin absorption and epidermal and hepatic metabolism of aromatic amine hair dyes in vitro

    International Nuclear Information System (INIS)

    Manwaring, John; Rothe, Helga; Obringer, Cindy; Foltz, David J.; Baker, Timothy R.; Troutman, John A.; Hewitt, Nicola J.; Goebel, Carsten

    2015-01-01

    Approaches to assess the role of absorption, metabolism and excretion of cosmetic ingredients that are based on the integration of different in vitro data are important for their safety assessment, specifically as it offers an opportunity to refine that safety assessment. In order to estimate systemic exposure (AUC) to aromatic amine hair dyes following typical product application conditions, skin penetration and epidermal and systemic metabolic conversion of the parent compound was assessed in human skin explants and human keratinocyte (HaCaT) and hepatocyte cultures. To estimate the amount of the aromatic amine that can reach the general circulation unchanged after passage through the skin the following toxicokinetically relevant parameters were applied: a) Michaelis–Menten kinetics to quantify the epidermal metabolism; b) the estimated keratinocyte cell abundance in the viable epidermis; c) the skin penetration rate; d) the calculated Mean Residence Time in the viable epidermis; e) the viable epidermis thickness and f) the skin permeability coefficient. In a next step, in vitro hepatocyte K m and V max values and whole liver mass and cell abundance were used to calculate the scaled intrinsic clearance, which was combined with liver blood flow and fraction of compound unbound in the blood to give hepatic clearance. The systemic exposure in the general circulation (AUC) was extrapolated using internal dose and hepatic clearance, and C max was extrapolated (conservative overestimation) using internal dose and volume of distribution, indicating that appropriate toxicokinetic information can be generated based solely on in vitro data. For the hair dye, p-phenylenediamine, these data were found to be in the same order of magnitude as those published for human volunteers. - Highlights: • An entirely in silico/in vitro approach to predict in vivo exposure to dermally applied hair dyes • Skin penetration and epidermal conversion assessed in human skin explants and

  19. Study of a Steel’s Energy Absorption System for Heavy Quadricycles and Nonlinear Explicit Dynamic Analysis of its Behavior under Impact by FEM

    Science.gov (United States)

    López Campos, José Ángel; Segade Robleda, Abraham; Vilán Vilán, José Antonio; García Nieto, Paulino José; Blanco Cordero, Javier

    2015-01-01

    Current knowledge of the behavior of heavy quadricycles under impact is still very poor. One of the most significant causes is the lack of energy absorption in the vehicle frame or its steel chassis structure. For this reason, special steels (with yield stresses equal to or greater than 350 MPa) are commonly used in the automotive industry due to their great strain hardening properties along the plastic zone, which allows good energy absorption under impact. This paper presents a proposal for a steel quadricycle energy absorption system which meets the percentages of energy absorption for conventional vehicles systems. This proposal is validated by explicit dynamics simulation, which will define the whole problem mathematically and verify behavior under impact at speeds of 40 km/h and 56 km/h using the finite element method (FEM). One of the main consequences of this study is that this FEM–based methodology can tackle high nonlinear problems like this one with success, avoiding the need to carry out experimental tests, with consequent economical savings since experimental tests are very expensive. Finally, the conclusions from this innovative research work are given. PMID:28793607

  20. Study of a Steel’s Energy Absorption System for Heavy Quadricycles and Nonlinear Explicit Dynamic Analysis of its Behavior under Impact by FEM

    Directory of Open Access Journals (Sweden)

    José Ángel López Campos

    2015-10-01

    Full Text Available Current knowledge of the behavior of heavy quadricycles under impact is still very poor. One of the most significant causes is the lack of energy absorption in the vehicle frame or its steel chassis structure. For this reason, special steels (with yield stresses equal to or greater than 350 MPa are commonly used in the automotive industry due to their great strain hardening properties along the plastic zone, which allows good energy absorption under impact. This paper presents a proposal for a steel quadricycle energy absorption system which meets the percentages of energy absorption for conventional vehicles systems. This proposal is validated by explicit dynamics simulation, which will define the whole problem mathematically and verify behavior under impact at speeds of 40 km/h and 56 km/h using the finite element method (FEM. One of the main consequences of this study is that this FEM–based methodology can tackle high nonlinear problems like this one with success, avoiding the need to carry out experimental tests, with consequent economical savings since experimental tests are very expensive. Finally, the conclusions from this innovative research work are given.

  1. Performance of hybrid quad generation system consisting of solid oxide fuel cell system and absorption heat pump

    DEFF Research Database (Denmark)

    Cachorro, Irene Albacete; Daraban, Iulia Maria; Lainé, Guillaume

    2013-01-01

    . The heat pump is a heat driven system and is running with the heat recovered by a heat exchanger from the exhausted gases from SOFC. The working fluid pair is NH3-H2O and is driven in two evaporators which are working at two different pressures. Thus, the heat pump will operate at tree pressure level...... with natural gas. The natural gas is first converted to a mixture of H2 and CO which feed the anode after a preheating step. The cathode is supplied with preheated air and gives, as output, electrical energy. The anode output is the exhaust gas which represents the thermal energy reservoir for heating...

  2. Ideology of a multiparametric system for estimating the insulation system of electric machines on the basis of absorption testing methods

    Science.gov (United States)

    Kislyakov, M. A.; Chernov, V. A.; Maksimkin, V. L.; Bozhin, Yu. M.

    2017-12-01

    The article deals with modern methods of monitoring the state and predicting the life of electric machines. In 50% of the cases of failure in the performance of electric machines is associated with insulation damage. As promising, nondestructive methods of control, methods based on the investigation of the processes of polarization occurring in insulating materials are proposed. To improve the accuracy of determining the state of insulation, a multiparametric approach is considered, which is a basis for the development of an expert system for estimating the state of health.

  3. Time-resolved and steady-state studies of biologically and chemically relevant systems using laser, absorption, and fluorescence spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, Charles Ashley [Iowa State Univ., Ames, IA (United States)

    2014-12-20

    In Chapter 2 several experimental and data analysis methods used in this thesis are described. In Chapter 3 steady-state fluorescence spectroscopy was used to determine the concentration of the efflux pump inhibitors (EPIs), pheophorbide a and pyropheophorbide a, in the feces of animals and it was found that their levels far exceed those reported to be inhibitory to efflux pumps. In Chapter 4 the solvation dynamics of 6-Propionyl-2-(N,Ndimethyl) aminonaphthalene (PRODAN) was studied in reverse micelles. The two fluorescent states of PRODAN solvate on different time scales and as such care must be exercised in solvation dynamic studies involving it and its analogs. In Chapter 5 we studied the experimental and theoretical solvation dynamics of coumarin 153 (C153) in wild-type (WT) and modified myoglobins. Based on the nuclear magnetic resonance (NMR) spectroscopy and time-resolved fluorescence studies, we have concluded that it is important to thoroughly characterize the structure of a protein and probe system before comparing the theoretical and experimental results. In Chapter 6 the photophysical and spectral properties of a derivative of the medically relevant compound curcumin called cyclocurcumin was studied. Based on NMR, fluorescence, and absorption studies, the ground- and excited-states of cyclocurcumin are complicated by the existence of multiple structural isomers. In Chapter 7 the hydrolysis of cellulose by a pure form of cellulase in an ionic liquid, HEMA, and its aqueous mixtures at various temperatures were studied with the goal of increasing the cellulose to glucose conversion for biofuel production. It was found that HEMA imparts an additional stability to cellulase and can allow for faster conversion of cellulose to glucose using a pre-treatment step in comparison to only buffer.

  4. In Vivo Dissolution and Systemic Absorption of Immediate Release Ibuprofen in Human Gastrointestinal Tract under Fed and Fasted Conditions.

    Science.gov (United States)

    Koenigsknecht, Mark J; Baker, Jason R; Wen, Bo; Frances, Ann; Zhang, Huixia; Yu, Alex; Zhao, Ting; Tsume, Yasuhiro; Pai, Manjunath P; Bleske, Barry E; Zhang, Xinyuan; Lionberger, Robert; Lee, Allen; Amidon, Gordon L; Hasler, William L; Sun, Duxin

    2017-12-04

    In vivo drug dissolution in the gastrointestinal (GI) tract is largely unmeasured. The purpose of this clinical study was to evaluate the in vivo drug dissolution and systemic absorption of the BCS class IIa drug ibuprofen under fed and fasted conditions by direct sampling of stomach and small intestinal luminal content. Expanding current knowledge of drug dissolution in vivo will help to establish physiologically relevant in vitro models predictive of drug dissolution. A multilumen GI catheter was orally inserted into the GI tract of healthy human subjects. Subjects received a single oral dose of ibuprofen (800 mg tablet) with 250 mL of water under fasting and fed conditions. The GI catheter facilitated collection of GI fluid from the stomach, duodenum, and jejunum. Ibuprofen concentration in GI fluid supernatant and plasma was determined by LC-MS/MS. A total of 23 subjects completed the study, with 11 subjects returning for an additional study visit (a total of 34 completed study visits). The subjects were primarily white (61%) and male (65%) with an average age of 30 years. The subjects had a median [min, max] weight of 79 [52, 123] kg and body mass index of 25.7 [19.4, 37.7] kg/m 2 . Ibuprofen plasma levels were higher under fasted conditions and remained detectable for 28 h under both conditions. The AUC 0-24 and C max were lower in fed subjects vs fasted subjects, and T max was delayed in fed subjects vs fasted subjects. Ibuprofen was detected immediately after ingestion in the stomach under fasting and fed conditions until 7 h after dosing. Higher levels of ibuprofen were detected in the small intestine soon after dosing in fasted subjects compared to fed. In contrast to plasma drug concentration, overall gastric concentrations remained higher under fed conditions due to increased gastric pH vs fasting condition. The gastric pH increased to near neutrality after feedingbefore decreasing to acidic levels after 7 h. Induction of the fed state reduced systemic

  5. Two-dimensional atom localization via a coherence-controlled absorption spectrum in an N-tripod-type five-level atomic system

    Energy Technology Data Exchange (ETDEWEB)

    Ding Chunling; Li Jiahua; Yang Xiaoxue [Wuhan National Laboratory for Optoelectronics and School of Physics, Huazhong University of Science and Technology, Wuhan 430074 (China); Zhan Zhiming [School of Physics and Information Engineering, Jianghan University, Wuhan 430056 (China); Liu Jibing, E-mail: clding2006@126.com, E-mail: huajia_li@163.com [Department of Physics, Hubei Normal University, Huangshi 435002 (China)

    2011-07-28

    A scheme of two-dimensional atom localization based on a coherence-controlled absorption spectrum in an N-tripod-type five-level system is proposed, in which the atom interacts with a weak probe field and three standing-wave fields. Position information of the atom can be achieved by measuring the probe absorption. It is found that the localization properties are significantly improved due to the interaction of dark resonances. It is also shown that the localization factors depend strongly on the system parameters that lead to such spatial structures of localization as chain-like, wave-like, '8'-like, spike-like, crater-like and heart-like patterns. By properly adjusting the system parameters, we can achieve a high-precision and high-resolution atom localization under certain conditions.

  6. Simulation of an air conditioning absorption refrigeration system in a co-generation process combining a proton exchange membrane fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Pilatowsky, I.; Gamboa, S.A.; Rivera, W. [Centro de Investigacion en Energia - UNAM, Temixco, Morelos (Mexico); Romero, R.J. [Centro de Investigacion en Ingenieria y Ciencias Aplicadas - UAEM, Cuernavaca, Morelos (Mexico); Isaza, C.A. [Universidad Pontificia Bolivariana, Medellin (Colombia). Instituto de Energia y Termodinamica; Sebastian, P.J. [Centro de Investigacion en Energia - UNAM, Temixco, Morelos (Mexico); Cuerpo Academico de Energia y Sustentabilidad-UP Chiapas, Tuxtla Gutierrez, Chiapas (Mexico); Moreira, J. [Cuerpo Academico de Energia y Sustentabilidad-UP Chiapas, Tuxtla Gutierrez, Chiapas (Mexico)

    2007-10-15

    In this work, a computer simulation program was developed to determine the optimum operating conditions of an air conditioning system during the co-generation process. A 1 kW PEMFC was considered in this study with a chemical/electrical theoretical efficiency of 40% and a thermal efficiency of 30% applying an electrical load of 100%. A refrigeration-absorption cycle (RAC) operating with monomethylamine-water solutions (MMA-WS), with low vapor generation temperatures (up to 80 C) is proposed in this work. The computer simulation was based on the refrigeration production capacity at the maximum power capacity of the PEMFC. Heat losses between the fuel cell and the absorption air conditioning system at standard operating conditions were considered to be negligible. The results showed the feasibility of using PEMFC for cooling, increasing the total efficiency of the fuel cell system. (author)

  7. Two-dimensional atom localization via a coherence-controlled absorption spectrum in an N-tripod-type five-level atomic system

    International Nuclear Information System (INIS)

    Ding Chunling; Li Jiahua; Yang Xiaoxue; Zhan Zhiming; Liu Jibing

    2011-01-01

    A scheme of two-dimensional atom localization based on a coherence-controlled absorption spectrum in an N-tripod-type five-level system is proposed, in which the atom interacts with a weak probe field and three standing-wave fields. Position information of the atom can be achieved by measuring the probe absorption. It is found that the localization properties are significantly improved due to the interaction of dark resonances. It is also shown that the localization factors depend strongly on the system parameters that lead to such spatial structures of localization as chain-like, wave-like, '8'-like, spike-like, crater-like and heart-like patterns. By properly adjusting the system parameters, we can achieve a high-precision and high-resolution atom localization under certain conditions.

  8. Nonlinear Absorption-Gain Response and Population Dynamics in a Laser-Driven Four-Level Dense Atomic System

    International Nuclear Information System (INIS)

    Li Jiahua; Liu Jibing; Luo Jinming; Xie Xiaotao

    2006-01-01

    We theoretically investigate the response of nonlinear absorption and population dynamics in optically dense media of four-level atoms driven by a single-mode probe laser, via taking the density-dependent near dipole-dipole (NDD) interactions into consideration. The influence of the NDD effects on the absorption of the probe field and population dynamics is predicted via numerical calculations. It is shown that the NDD effects can reduce gradually to transient absorption with the increase of the strengths of the NDD interactions, and transient amplification can be achieved. In the steady-state limit, the probe field exhibits transparency for strong NDD interactions. Alternatively, the population entirely remains at the ground state due to the NDD effects.

  9. Comparison of systemic absorption between ofloxacin ophthalmic in situ gels and ofloxacin conventional ophthalmic solutions administration to rabbit eyes by HPLC-MS/MS.

    Science.gov (United States)

    Li, Jiawei; Zhao, Hainan; Okeke, Chukwunweike Ikechukwu; Li, Lin; Liu, Zhidong; Yin, Zhongpeng; Zhuang, Pengwei; Sun, Jingtong; Wu, Tao; Wang, Meng; Li, Nan; Pi, Jiaxin; Zhang, Qian; Zhang, Rui; Ma, Li; Pang, Xiaochen; Liu, Zhanbiao; Zhang, Li; Fan, Lili

    2013-06-25

    In recent years, many pharmaceutical scientists have focused on developing the in situ gel-forming systems to overcome the poor bioavailability and therapeutic response exhibited by conventional ophthalmic solutions due to rapid pre-corneal elimination of the drug. The present work was to compare the systemic absorptions of ophthalmic ofloxacin in situ gel with the conventional ofloxacin eye drop after topical instillation to rabbit eyes by HPLC-MS/MS method and also determine the relative contribution of the nasal and the conjunctival mucosae to systemic ofloxacin absorption following topical instillation. The systemic AUC, Cmax, Tmax and Ke for ophthalmic in situ gel and ophthalmic solution after ocular instillation were 202.63±118.85 and 202.25±57.74 ng mL(-1) h, 54.22±28.31 and 48.4±25.97 ng mL(-1), 1.08±0.20 and 1.25±0.88 h, 0.0576±0.0207 and 0.0388±0.0248, respectively. And the values for the ratios of the AUC of anterior chamber of rabbit eye to blood plasma, AUCac/AUCpl, for ofloxacin conventional eye drop and in situ gel were 0.25 and 0.52, respectively. Statistic results showed that there was no significant difference in systemic absorption between the test groups and the reference groups (P>0.05) as both formulations have an AUCsa/AUCpl of 0.35. Therefore, the ophthalmic in situ gel may not decrease the drugs systemic absorption when administered in an equivalent dose as ophthalmic solutions into the rabbit eyes. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. An Intercomparison Study of Two Proximate Damped Lyα Systems with Residual Flux upon the Lyα Absorption Trough toward Quasars

    Science.gov (United States)

    Xie, Xiaoyi; Zhou, Hongyan; Pan, Xiang; Jiang, Peng; Shi, Xiheng; Ji, Tuo; Zhang, Shaohua; Wu, Shengmiao; Zhong, Zhihao

    2018-05-01

    In this paper, we present an intercomparison study of two quasars, SDSS J145618.32+340037.2 and SDSS J215331.50–025514.1, which have proximate damped Lyα systems (PDLAs) with residual flux upon the Lyα absorption trough. Though they both have residual flux as luminous as 1043 erg s‑1, their PDLAs are quite different in, e.g., neutral hydrogen column density, metal line absorption strength, high-ionization absorption lines as well as residual flux strength. For J1456+3400, the H I column density is log(N H I /cm–2) = 20.6 ± 0.2, with z abs = 2.3138, nearly identical to the quasar redshift (z = 2.3142) determined from the [O III] emission line. The metallicity of this system is typical of DLAs and there is high ionization therein, suggesting that the PDLA system is multiphase, putting it in the quasar environment. For J2153–0255, we measure the H I column density to be log(N H I /cm–2) = 21.5 ± 0.1 at z abs = 3.511, slightly redshifted with respect to the quasar (z = 3.490) measured from C III]. The metallicity of this system is quite low and there is a lack of significant high-ionization absorption lines therein, suggesting that the system is beyond the quasar host galaxy. The residual flux is wide (∼1000 km s‑1) in J1456, with a significance of ∼8σ, while also wide (∼1500 km s‑1) but with a smaller significance of ∼3σ in J2153. Among many explanations, we find that Lyα fuzz or resonant scattering can be used to explain the residual flux in the two sources while partial coverage cannot be excluded for J1456. By comparing these two cases, together with a similar case reported previously, we suggest that the strength of the residual flux is related to properties such as metallicity and high-ionization absorption lines of PDLAs. The residual flux recorded upon the PDLA absorption trough opens a window for us to see the physical conditions and processes of the quasar environment, and their profile and strength further remind us of their

  11. Determination of serum aluminum by electrothermal atomic absorption spectrometry: A comparison between Zeeman and continuum background correction systems

    Energy Technology Data Exchange (ETDEWEB)

    Kruger, Pamela C. [Department of Environmental Health Sciences, School of Public Health, University at Albany, State University of New York, P.O. Box 509, Albany, NY 12201-0509 (United States); Parsons, Patrick J. [Department of Environmental Health Sciences, School of Public Health, University at Albany, State University of New York, P.O. Box 509, Albany, NY 12201-0509 (United States); Lead Poisoning/Trace Elements Laboratory, Wadsworth Center, New York State Department of Health, P.O. Box 509, Albany, NY 12201-0509 (United States)], E-mail: patrick.parsons@wadsworth.org

    2007-03-15

    Excessive exposure to aluminum (Al) can produce serious health consequences in people with impaired renal function, especially those undergoing hemodialysis. Al can accumulate in the brain and in bone, causing dialysis-related encephalopathy and renal osteodystrophy. Thus, dialysis patients are routinely monitored for Al overload, through measurement of their serum Al. Electrothermal atomic absorption spectrometry (ETAAS) is widely used for serum Al determination. Here, we assess the analytical performances of three ETAAS instruments, equipped with different background correction systems and heating arrangements, for the determination of serum Al. Specifically, we compare (1) a Perkin Elmer (PE) Model 3110 AAS, equipped with a longitudinally (end) heated graphite atomizer (HGA) and continuum-source (deuterium) background correction, with (2) a PE Model 4100ZL AAS equipped with a transversely heated graphite atomizer (THGA) and longitudinal Zeeman background correction, and (3) a PE Model Z5100 AAS equipped with a HGA and transverse Zeeman background correction. We were able to transfer the method for serum Al previously established for the Z5100 and 4100ZL instruments to the 3110, with only minor modifications. As with the Zeeman instruments, matrix-matched calibration was not required for the 3110 and, thus, aqueous calibration standards were used. However, the 309.3-nm line was chosen for analysis on the 3110 due to failure of the continuum background correction system at the 396.2-nm line. A small, seemingly insignificant overcorrection error was observed in the background channel on the 3110 instrument at the 309.3-nm line. On the 4100ZL, signal oscillation was observed in the atomization profile. The sensitivity, or characteristic mass (m{sub 0}), for Al at the 309.3-nm line on the 3110 AAS was found to be 12.1 {+-} 0.6 pg, compared to 16.1 {+-} 0.7 pg for the Z5100, and 23.3 {+-} 1.3 pg for the 4100ZL at the 396.2-nm line. However, the instrumental detection

  12. Multiculturalism in Schools: The Professional Absorption of Immigrant Teachers from the Former USSR into the Education System in Israel

    Science.gov (United States)

    Michael, Orly

    2006-01-01

    The purpose of this research was to determine the professional absorption of immigrant teachers from the Former Soviet Union in comparison to veteran teachers working in the same schools in Israel. Findings are based on data from 272 questionnaires. The sample included 117 teachers working in Israeli schools who immigrated from the Former Soviet…

  13. Nonflame atomic absorption determination of total mercury in natural waters using an HS-3 mercury-hydride system

    Energy Technology Data Exchange (ETDEWEB)

    Evdokimova, E.V.; Solov`eva, M.Kh.; Telegin, G.F. [Institute of Problems in the Technology of Microelectronics and High-Purity Materials, Moscow (Russian Federation)

    1995-02-01

    A method for nonflame atomic absorption determination of mercury with a detection limit of 1 x 10{sup -3} {mu}g/ml in natural waters without preconcentration is described. The method can be applied successfully in analysis of the environment.

  14. [Construction of research system for processing mechanism of traditional Chinese medicine based on chemical composition transformation combined with intestinal absorption barrier].

    Science.gov (United States)

    Sun, E; Xu, Feng-Juan; Zhang, Zhen-Hai; Wei, Ying-Jie; Tan, Xiao-Bin; Cheng, Xu-Dong; Jia, Xiao-Bin

    2014-02-01

    Based on practice of Epimedium processing mechanism for many years and integrated multidisciplinary theory and technology, this paper initially constructs the research system for processing mechanism of traditional Chinese medicine based on chemical composition transformation combined with intestinal absorption barrier, which to form an innovative research mode of the " chemical composition changes-biological transformation-metabolism in vitro and in vivo-intestinal absorption-pharmacokinetic combined pharmacodynamic-pharmacodynamic mechanism". Combined with specific examples of Epimedium and other Chinese herbal medicine processing mechanism, this paper also discusses the academic thoughts, research methods and key technologies of this research system, which will be conducive to systematically reveal the modem scientific connotation of traditional Chinese medicine processing, and enrich the theory of Chinese herbal medicine processing.

  15. Absorption heat pump integrated in an effluent purification system; Bomba de calor por absorcion integrada a un sistema de purificacion de efluentes

    Energy Technology Data Exchange (ETDEWEB)

    Santoyo, Socrates; Siqueiros, Javier; Heard, Christopher; Santoyo, Edgar [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1996-12-31

    The results derived of the integration of an absorption heat pump to an industrial effluents purification system, are presented. The advantages of these heat pumps with respect to heat pumps by mechanical compression of vapor, as well as the advantages in using absorption heat pumps in simple distillation systems, are mentioned. Finally, a description is made of the equipment designed and built, as well as the results obtained in a preliminary test. [Espanol] Se presentan los resultados derivados de la integracion de una bomba de calor por absorcion a un sistema de purificacion de efluentes industriales. Se mencionan las ventajas de este tipo de bombas de calor con respecto a las de calor por compresion mecanica de vapor, asi como las ventajas de usar bombas de calor en sistemas de destilacion simple. Finalmente, se describe el equipo disenado y construido, asi como los resultados obtenidos de una prueba preliminar.

  16. Absorption heat pump integrated in an effluent purification system; Bomba de calor por absorcion integrada a un sistema de purificacion de efluentes

    Energy Technology Data Exchange (ETDEWEB)

    Santoyo, Socrates; Siqueiros, Javier; Heard, Christopher; Santoyo, Edgar [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1997-12-31

    The results derived of the integration of an absorption heat pump to an industrial effluents purification system, are presented. The advantages of these heat pumps with respect to heat pumps by mechanical compression of vapor, as well as the advantages in using absorption heat pumps in simple distillation systems, are mentioned. Finally, a description is made of the equipment designed and built, as well as the results obtained in a preliminary test. [Espanol] Se presentan los resultados derivados de la integracion de una bomba de calor por absorcion a un sistema de purificacion de efluentes industriales. Se mencionan las ventajas de este tipo de bombas de calor con respecto a las de calor por compresion mecanica de vapor, asi como las ventajas de usar bombas de calor en sistemas de destilacion simple. Finalmente, se describe el equipo disenado y construido, asi como los resultados obtenidos de una prueba preliminar.

  17. Exergetic and energetic comparison of LiCl-H_2O and LiBr-H_2O working pairs in a solar absorption cooling system

    International Nuclear Information System (INIS)

    Bellos, Evangelos; Tzivanidis, Christos; Antonopoulos, Kimon A.

    2016-01-01

    Highlights: • Two working pairs (LiCl-H_2O and LiBr-H_2O) are examined in a solar absorption chiller. • The examined single effect absorption chiller is driven by flat plate collectors. • The system is analyzed energetically and energetically for 3 ambient temperatures. • LiCl-H_2O performs better than LiBr-H_2O in all the examined cases. • The optimum operating temperature is lower for the case of pair LiCl-H_2O. - Abstract: The objective of this study is to investigate the use of an alternative working pair in a solar absorption cooling system. LiCl-H_2O is the new examined pair and it is compared energetically and exegetically with the conventional pair LiBr-H_2O, which is the most usual in air-conditioning applications. The simplest solar cooling system is analyzed in order to focus in the comparison between these working fluids. Specifically, flat plate collectors, coupled with a storage tank, feed the single effect absorption chiller which produces 250 kW cooling at 10 °C. The two pairs are examined parametrically for various heat source temperature levels and for three ambient temperature levels (25 °C, 30 °C and 35 °C). The minimization of the collecting area, which means maximum exergetic efficiency, is the optimization goal in every case. The final results show that LiCl-H_2O pair performs better in all cases by giving greater exergetic efficiency. More specifically, about 8% lower collecting area is required to cover the demanded cooling load with this working pair. Another interesting result is that the optimum heat source temperature for the LiCl-H_2O is roughly lower than the respective for the LiBr-H_2O. The system is analyzed in steady state with the commercial software Engineering Equator Solver (EES).

  18. A new parameterization for surface ocean light attenuation in Earth System Models: assessing the impact of light absorption by colored detrital material

    OpenAIRE

    G. E. Kim; M.-A. Pradal; A. Gnanadesikan

    2015-01-01

    Light limitation can affect the distribution of biota and nutrients in the ocean. Light absorption by colored detrital material (CDM) was included in a fully coupled Earth System Model using a new parameterization for shortwave attenuation. Two model runs were conducted, with and without light attenuation by CDM. In a global average sense, greater light limitation associated with CDM increased surface chlorophyll, biomass and nutrients together. These changes can be attribut...

  19. Annual performance investigation and economic analysis of heating systems with a compression-assisted air source absorption heat pump

    International Nuclear Information System (INIS)

    Wu, Wei; Shi, Wenxing; Wang, Baolong; Li, Xianting

    2015-01-01

    Highlights: • Optimal compression ratio of CASAHP is obtained for the maximum energy saving rate. • Annual performance is improved by 10–20% compared to ASAHP without compression. • Energy saving rate is 17.7–29.2% and investment is reduced to 30–60% for CASAHP. • Both compression and partial-design enhance the economy with given energy saving. • Payback time is reduced from 12–32 to 3–6 years by compression and partial-design. - Abstract: The compression-assisted air source absorption heat pump (CASAHP) is a promising alternative heating system in severe operating conditions. In this research, parameter studies on the annual performance under various compression ratios (CRs) and source temperatures are performed to achieve the maximum energy saving rates (ESRs). Economic analyses of the CASAHP under different CRs and partial-design ratios are conducted to obtain an optimal design that considers both energy savings and economy improvements. The results show that the optimal CR becomes higher in colder regions and with lower heat source temperatures. For a source temperature of 130 °C, the optimal CR values in all of the cities are within 2.0. For source temperatures from 100 to 130 °C, the maximum ESR is in the range of 17.7–29.2% in the studied cities. The efficiency improvement rate (EIR) caused by compression in a severe source condition can reach 10.0–20.0%. From the viewpoint of economy, the relative investment of CASAHP is reduced to 30–60% with a CR of 2.0–3.0. With a 2–6% sacrifice in ESR, the payback period can be reduced from 12–32 to 5–9 years using compression. Partial-design of the CASAHP can further reduce the payback period to 3–6 years with a partial-design ratio of 50% and a CR of 2.8. Additionally, CRs and partial-design ratios are designed comprehensively by seeking the maximum ESR for a given acceptable payback period

  20. Exergy based parametric analysis of a combined reheat regenerative thermal power plant and water–LiBr vapor absorption refrigeration system

    International Nuclear Information System (INIS)

    Gogoi, T.K.; Talukdar, K.

    2014-01-01

    Highlights: • Exergy analysis of a combined power–absorption cooling system is provided. • Exergetic efficiency of the power cycle and absorption cooling system are calculated. • Irreversibility in each component and total system irreversibility are calculated. • Effect of operating parameters on exergetic performance and irreversibility is analyzed. • Optimum operating parameters are identified based on energy and exergy based results. - Abstract: In this paper, exergy analysis of a combined reheat regenerative steam turbine (ST) based power cycle and water–LiBr vapor absorption refrigeration system (VARS) is presented. Exergetic efficiency of the power cycle and VARS, energy utilization factor (EUF) of the combined system (CS) and irreversibility in each system component are calculated. The effect of fuel flow rate, boiler pressure, cooling capacity and VARS components’ temperature on performance, component and total system irreversibility is analyzed. The second law based results indicate optimum performance at 150 bar boiler pressure and VARS generator, condenser, evaporator and absorber temperature of 80 °C, 37.5 °C, 15 °C and 35 °C respectively. The present exergy based results conform well to the first law based results obtained in a previous analysis done on the same combined system. Irreversibility distribution among various power cycle components shows the highest irreversibility in the cooling tower. Irreversibility of the exhaust flue gas leaving the boiler and the boiler are the next major contributors. Among the VARS components, exergy destruction in the generator is the highest followed by irreversibility contribution of the absorber, condenser and the evaporator

  1. System for time-resolved laser absorption spectroscopy and its application to high-power impulse magnetron sputtering

    Czech Academy of Sciences Publication Activity Database

    Adámek, Petr; Olejníček, Jiří; Hubička, Zdeněk; Čada, Martin; Kment, Štěpán; Kohout, Michal; Do, H.T.

    2017-01-01

    Roč. 88, č. 2 (2017), 1-8, č. článku 023105. ISSN 0034-6748 R&D Projects: GA TA ČR(CZ) TF01000084; GA ČR(CZ) GA15-00863S Institutional support: RVO:68378271 Keywords : plasma diagnostics * HiPIMS * time resolved measurement * laser absorption spectroscopy Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 1.515, year: 2016

  2. Modelling LiBr-H2O solution concentration/crystallization of low thermal-powered absorption air conditioning system

    International Nuclear Information System (INIS)

    Abdullah, M.O.

    2000-01-01

    A computer model is developed to predict the concentration of lithium bromide - water (LiBr-H 2 O) solution for used in low thermal energy-driven absorption air conditioning plants design. The computer program is capable to alert the users from undesirable solidification or crystallization zones. Good agreements between simulated concentration and experimental data from standard chart/table have been obtained. (Author)

  3. A preconcentration system for determination of copper and nickel in water and food samples employing flame atomic absorption spectrometry

    OpenAIRE

    Tuzen, Mustafa; Soylak, Mustafa; Citak, Demirhan; Ferreira, Hadla S.; Korn, Maria das Graças Andrade; Bezerra, Marcos de Almeida

    2009-01-01

    Texto completo: acesso restrito. p. 1041-1045 A separation/preconcentration procedure using solid phase extraction has been proposed for the flame atomic absorption spectrometric determination of copper and nickel at trace level in food samples. The solid phase is Dowex Optipore SD-2 resin contained on a minicolumn, where analyte ions are sorbed as 5-methyl-4-(2-thiazolylazo) resorcinol chelates. After elution using 1 mol L−1 nitric acid solution, the analytes are determinate employing fla...

  4. DETECTING THE WARM-HOT INTERGALACTIC MEDIUM THROUGH X-RAY ABSORPTION LINES

    Energy Technology Data Exchange (ETDEWEB)

    Yao Yangsen; Shull, J. Michael; Cash, Webster [Center for Astrophysics and Space Astronomy, Department of Astrophysical and Planetary Sciences, University of Colorado, 389 UCB, Boulder, CO 80309 (United States); Wang, Q. Daniel, E-mail: yaoys@colorado.edu [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States)

    2012-02-20

    The warm-hot intergalactic medium (WHIM) at temperatures 10{sup 5}-10{sup 7} K is believed to contain 30%-50% of the baryons in the local universe. However, all current X-ray detections of the WHIM at redshifts z > 0 are of low statistical significance ({approx}< 3{sigma}) and/or controversial. In this work, we aim to establish the detection limits of current X-ray observatories and explore requirements for next-generation X-ray telescopes for studying the WHIM through X-ray absorption lines. We analyze all available grating observations of Mrk 421 and obtain spectra with signal-to-noise ratios (S/Ns) of {approx}90 and 190 per 50 mA spectral bin from Chandra and XMM-Newton observations, respectively. Although these spectra are two of the best ever collected with Chandra and XMM-Newton, we cannot confirm the two WHIM systems reported by Nicastro et al. in 2005. Our bootstrap simulations indicate that spectra with such high S/N cannot constrain the WHIM with O VII column densities N{sub Ovii}{approx}10{sup 15} cm{sup -2} (corresponding to an equivalent width of 2.5 mA for a Doppler velocity of 50 km s{sup -1}) at {approx}> 3{sigma} significance level. The simulation results also suggest that it would take >60 Ms for Chandra and 140 Ms for XMM-Newton to measure the N{sub Ovii} at {>=}4{sigma} from a spectrum of a background QSO with flux of {approx}0.2 mCrab (1 Crab = 2 Multiplication-Sign 10{sup -8} erg s{sup -1} cm{sup -2} at 0.5-2 keV). Future X-ray spectrographs need to be equipped with spectral resolution R {approx} 4000 and effective area A {>=} 100 cm{sup 2} to accomplish the similar constraints with an exposure time of {approx}2 Ms and would require {approx}11 Ms to survey the 15 QSOs with flux {approx}> 0.2 mCrab along which clear intergalactic O VI absorbers have been detected.

  5. Proposal for efficient two-dimensional atom localization using probe absorption in a microwave-driven four-level atomic system

    International Nuclear Information System (INIS)

    Ding Chunling; Li Jiahua; Yang Xiaoxue; Xiong Hao; Zhang Duo

    2011-01-01

    The behavior of two-dimensional (2D) atom localization is explored by monitoring the probe absorption in a microwave-driven four-level atomic medium under the action of two orthogonal standing-wave fields. Because of the position-dependent atom-field interaction, the information about the position of the atom can be obtained via the absorption measurement of the weak probe field. It is found that the localization behavior is significantly improved due to the joint quantum interference induced by the standing-wave and microwave-driven fields. Most importantly, the atom can be localized at a particular position and the maximal probability of finding the atom in one period of the standing-wave fields reaches unity by properly adjusting the system parameters. The proposed scheme may provide a promising way to achieve high-precision and high-resolution 2D atom localization.

  6. Portable ultrahigh-vacuum sample storage system for polarization-dependent total-reflection fluorescence x-ray absorption fine structure spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Yoshihide, E-mail: e0827@mosk.tytlabs.co.jp; Nishimura, Yusaku F.; Suzuki, Ryo; Beniya, Atsushi; Isomura, Noritake [Toyota Central R& D Labs., Inc., Yokomichi 41-1, Nagakute, Aichi 480-1192 (Japan); Uehara, Hiromitsu; Asakura, Kiyotaka; Takakusagi, Satoru [Catalysis Research Center, Hokkaido University, Kita 21-10, Sapporo, Hokkaido 001-0021 (Japan); Nimura, Tomoyuki [AVC Co., Ltd., Inada 1450-6, Hitachinaka, Ibaraki 312-0061 (Japan)

    2016-03-15

    A portable ultrahigh-vacuum sample storage system was designed and built to investigate the detailed geometric structures of mass-selected metal clusters on oxide substrates by polarization-dependent total-reflection fluorescence x-ray absorption fine structure spectroscopy (PTRF-XAFS). This ultrahigh-vacuum (UHV) sample storage system provides the handover of samples between two different sample manipulating systems. The sample storage system is adaptable for public transportation, facilitating experiments using air-sensitive samples in synchrotron radiation or other quantum beam facilities. The samples were transferred by the developed portable UHV transfer system via a public transportation at a distance over 400 km. The performance of the transfer system was demonstrated by a successful PTRF-XAFS study of Pt{sub 4} clusters deposited on a TiO{sub 2}(110) surface.

  7. A microprocessor controlled system for pulsed laser experiments nad its applications in two photon absorption spectroscopy of CaF2: Eu+2

    International Nuclear Information System (INIS)

    Nunes, L.A.O.; Matinaga, F.M.; Castro, J.C. de

    1986-01-01

    A very low cost data station for pulsed dye laser aplications is developed. The system employs a low cost single board microcomputer and low cost componenets. Details on the hardware configuration and sofware are presented. In order to demonstrate the power of this system we employed it to obtain a two photon absorption spectrum of some f→f transitions in europium ions present as impurity in CaF 2 . Flexibility of hardware and software allow other aplications, such as transient recording in the 10nsec per channel range and other real time data processing. (Author) [pt

  8. A VLT/MUSE galaxy survey towards QSO Q1410: looking for a WHIM traced by BLAs in inter-cluster filaments†

    Science.gov (United States)

    Pessa, Ismael; Tejos, Nicolas; Barrientos, L. Felipe; Werk, Jessica; Bielby, Richard; Padilla, Nelson; Morris, Simon L.; Prochaska, J. Xavier; Lopez, Sebastian; Hummels, Cameron

    2018-03-01

    Cosmological simulations predict that a significant fraction of the low-z baryon budget resides in large-scale filaments in the form of a diffuse plasma at temperatures T ˜ 105 - 107 K. However, direct observation of this so-called warm-hot intergalactic medium (WHIM) has been elusive. In the ΛCDM paradigm, galaxy clusters correspond to the nodes of the cosmic web at the intersection of several large-scale filamentary threads. In previous work, we used HST/COS data to conduct the first survey of broad H I Lyα absorbers (BLAs) potentially produced by WHIM in inter-cluster filaments. We targeted a single QSO, namely Q1410, whose sight-line intersects 7 independent inter-cluster axes at impact parameters cluster axes, we found 3 without any galaxy counterpart to stringent luminosity limits (˜4 × 108 L⊙ ˜0.01 L*), providing further evidence that these BLAs may represent genuine WHIM detections. We combined this sample with other suitable BLAs from the literature and inferred the corresponding baryon mean density for these filaments in the range Ω ^fil_bar= 0.02-0.04. Our rough estimates are consistent with the predictions from numerical simulations but still subject to large systematic uncertainties, mostly from the adopted geometry, ionization corrections and density profile.

  9. Optical absorption in dendrimers

    International Nuclear Information System (INIS)

    Supritz, C.; Engelmann, A.; Reineker, P.

    2004-01-01

    Dendrimers are highly branched molecules, which are expected to be useful, for example, as efficient artificial light harvesting systems in nano-technological applications. There are two different classes of dendrimers: compact dendrimers with constant distance between neighboring branching points throughout the macromolecule and extended dendrimers, where this distance increases from the system periphery to the center. We investigate the linear absorption spectra of these dendrimer types using the Frenkel exciton concept. The electron-phonon interaction is taken into account by introducing a heat bath that interacts with the exciton in a stochastic manner

  10. Exergy analysis of a combined vapor power cycle and boiler flue gas driven double effect water–LiBr absorption refrigeration system

    International Nuclear Information System (INIS)

    Talukdar, K.; Gogoi, T.K.

    2016-01-01

    Highlights: • A combined vapor power and double effect water–LiBr absorption refrigeration system is proposed. • The flue gas of the power cycle boiler is the heat source for the double effect refrigeration system. • Energy and exergy analyses are performed to evaluate performance of the combined system. • Effect of high pressure generator temperature on combined system performance is highlighted. • Comparison is provided with a single effect absorption system integrated combined system. - Abstract: A combined vapor power cycle (PC) and double effect water–LiBr absorption refrigeration system (ARS) is proposed in this study. The boiler leaving flue gas of the PC is the heat source for the high pressure generator (HPG) of the double effect ARS. Exergy analysis of the proposed system is performed to show the performance variation of both the topping PC and the bottoming ARS with changing HPG temperature from 120 °C to 150 °C. Further the performance of double effect ARS integrated combined power and cooling system is compared with a similar system integrated with a single effect ARS. HPG temperature of the double effect ARS and generator temperature of the single effect ARS are considered as 120 °C and 80 °C respectively. Results show that the power and efficiency of the topping PC decreases with HPG temperature due to reduction in steam generation rate in the boiler. COP and exergy efficiency of the double effect ARS also reduces with increasing HPG temperature. The irreversible losses in the PC components decrease while the total irreversibility of the combined power and cooling system increases with HPG temperature due to increase in exergy loss with the HPG leaving flue gas and irreversibility of the ARS components. PC performance does not vary much due to replacement of the double effect ARS with the single effect ARS, however higher COP and exergy efficiency of the double effect system are achieved with much lower irreversible losses in the

  11. Performance of one and a half-effect absorption cooling cycle of H2O/LiBr system

    International Nuclear Information System (INIS)

    Wang Jianzhao; Zheng Danxing

    2009-01-01

    The performances of half-effect, single-effect and double-effect H 2 O/LiBr absorption cooling cycles were analyzed, and it was found that there is an obvious blank for generation temperature between the maximum generation temperature of the single-effect cycle and the minimum generation temperature of the double-effect cycle. It was proposed that the one and a half-effect (1.5-effect) cycle can fill up the blank perfectly. The state of the art in the 1.5-effect cycles was reviewed and analyzed, and two new configurations of 1.5-effect cycles were proposed. Three configurations of 1.5-effect cycles, which are suitable for H 2 O/LiBr as working fluids, were selected to be analyzed in detail. The 1.5-effect cycle shows the optimum performance at the foregoing blank of generation temperature. For example, under the conditions of evaporation temperature t E is 5 deg. C, and condensation temperature t C is 42 deg. C, and absorption temperature t A is 37 deg. C, the optimum range of generation temperature t G for the 1.5-effect cycle is from 110 deg. C to 140 deg. C. The coefficient of performance of the 1.5-effect cycle is about 1.0, which is more than 30% higher than that of the single-effect cycle at the same condition. The effects of the efficiency of solution heat exchanger, the generation temperature, the absorption temperature (or the condensation temperature) and the evaporation temperature on the performances of the three configurations of 1.5-effect cycle were analyzed. It was shown that the configuration II, which is composed with a high-temperature single-effect subcycle and a low-temperature half-effect subcycle, has the highest coefficient of performance and the best operational flexibility. Among the four parameters analyzed, the performances of 1.5-effect cycles are most sensitive to the change of absorption temperature (or condensation temperature), and then to the change of generation temperature.

  12. Theory and operation of the real-time data acquisition system for the NASA-LaRC differential absorption lidar (DIAL)

    Science.gov (United States)

    Butler, Carolyn; Spencer, Randall

    1988-01-01

    The improvement of computer hardware and software of the NASA Multipurpose Differential Absorption Lidar (DIAL) system is documented. The NASA DIAL system has undergone development and experimental deployment at NASA/Langley Res. Center for the remote measurement of atmospheric trace gas concentrations from ground and aircraft platforms. A viable DIAL system was developed capable of remotely measuring O3 and H2O concentrations from an aircraft platform. The DIAL Data Acquisition System (DAS) has undergone a number of improvements also. Due to the participation of the DIAL in the Global Tropospheric Experiment, modifications and improvements of the system were tested and used both in the lab and in air. Therefore, this is an operational manual for the DIAL DAS.

  13. Microwaves absorption in superconducting materials

    International Nuclear Information System (INIS)

    Biasi, R.S. de; Fernandes, A.A.R.; Pereira, R.F.R.

    1989-01-01

    Microwaves absorption measures in two superconductors ceramics systems, Y-Ba-Cu-O and Bi-Sr-Ca-Cu-O are compared with similars datas obtained in the same band of temperature by a conventional method, mutual inductance. The results suggest that the microwaves absorption can be used as single and non-destructive method for investigating the properties of ceramics superconductors. (C.G.C.) [pt

  14. Surfactant/oil/water system for the determination of selenium in eggs by graphite furnace atomic absorption spectrometry

    Science.gov (United States)

    Ieggli, C. V. S.; Bohrer, D.; Noremberg, S.; do Nascimento, P. C.; de Carvalho, L. M.; Vieira, S. L.; Reis, R. N.

    2009-06-01

    An oil-in-water formulation has been optimized to determine trace levels of selenium in whole hen eggs by graphite furnace atomic absorption spectrometry. This method is simpler and requires fewer reagents when compared with other sample pre-treatment procedures. Graphite furnace atomic absorption spectrometric (GF AAS) measurement was carried out using standard addition calibration and Pd as a modifier. The precision, expressed as relative standard deviation, was better than 5% and the limit of detection was 1 µg L - 1 . The validation of the method was performed against a standard reference material Whole Egg Powder (RM 8415), and the measured Se corresponded to 95.2% of the certified value. The method was used for the determination of the Se level in eggs from hens treated with Se dietary supplements. Inorganic and organic Se sources were added to hen feed. The Se content of eggs was higher when hens were fed with organic Se compared to the other treatments. The proposed method, including sample emulsification for subsequent Se determination by GF AAS has proved to be sensitive, reproducible, simple and economical.

  15. Surfactant/oil/water system for the determination of selenium in eggs by graphite furnace atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Ieggli, C.V.S. [Departamento de Quimica, Avenida Roraima, 1000, Universidade Federal de Santa Maria, CEP 97110-970, Santa Maria, RS (Brazil); Bohrer, D. [Departamento de Quimica, Avenida Roraima, 1000, Universidade Federal de Santa Maria, CEP 97110-970, Santa Maria, RS (Brazil)], E-mail: ndenise@quimica.ufsm.br; Noremberg, S.; Nascimento, P.C. do; Carvalho, L.M. de [Departamento de Quimica, Avenida Roraima, 1000, Universidade Federal de Santa Maria, CEP 97110-970, Santa Maria, RS (Brazil); Vieira, S.L.; Reis, R.N. [Faculdade de Agronomia, Universidade Federal do Rio Grande do Sul, Av. Bento Goncalves, 7712, CEP 90540-000, Porto Alegre (Brazil)

    2009-06-15

    An oil-in-water formulation has been optimized to determine trace levels of selenium in whole hen eggs by graphite furnace atomic absorption spectrometry. This method is simpler and requires fewer reagents when compared with other sample pre-treatment procedures. Graphite furnace atomic absorption spectrometric (GF AAS) measurement was carried out using standard addition calibration and Pd as a modifier. The precision, expressed as relative standard deviation, was better than 5% and the limit of detection was 1 {mu}g L{sup - 1}. The validation of the method was performed against a standard reference material Whole Egg Powder (RM 8415), and the measured Se corresponded to 95.2% of the certified value. The method was used for the determination of the Se level in eggs from hens treated with Se dietary supplements. Inorganic and organic Se sources were added to hen feed. The Se content of eggs was higher when hens were fed with organic Se compared to the other treatments. The proposed method, including sample emulsification for subsequent Se determination by GF AAS has proved to be sensitive, reproducible, simple and economical.

  16. A preconcentration system for determination of copper and nickel in water and food samples employing flame atomic absorption spectrometry.

    Science.gov (United States)

    Tuzen, Mustafa; Soylak, Mustafa; Citak, Demirhan; Ferreira, Hadla S; Korn, Maria G A; Bezerra, Marcos A

    2009-03-15

    A separation/preconcentration procedure using solid phase extraction has been proposed for the flame atomic absorption spectrometric determination of copper and nickel at trace level in food samples. The solid phase is Dowex Optipore SD-2 resin contained on a minicolumn, where analyte ions are sorbed as 5-methyl-4-(2-thiazolylazo) resorcinol chelates. After elution using 1 mol L(-1) nitric acid solution, the analytes are determinate employing flame atomic absorption spectrometry. The optimization step was performed using a full two-level factorial design and the variables studied were: pH, reagent concentration (RC) and amount of resin on the column (AR). Under the experimental conditions established in the optimization step, the procedure allows the determination of copper and nickel with limit of detection of 1.03 and 1.90 microg L(-1), respectively and precision of 7 and 8%, for concentrations of copper and nickel of 200 microg L(-1). The effect of matrix ions was also evaluated. The accuracy was confirmed by analyzing of the followings certified reference materials: NIST SRM 1515 Apple leaves and GBW 07603 Aquatic and Terrestrial Biological Products. The developed method was successfully applied for the determination of copper and nickel in real samples including human hair, chicken meat, black tea and canned fish.

  17. A preconcentration system for determination of copper and nickel in water and food samples employing flame atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Tuzen, Mustafa; Soylak, Mustafa; Citak, Demirhan; Ferreira, Hadla S.; Korn, Maria G.A.; Bezerra, Marcos A.

    2009-01-01

    A separation/preconcentration procedure using solid phase extraction has been proposed for the flame atomic absorption spectrometric determination of copper and nickel at trace level in food samples. The solid phase is Dowex Optipore SD-2 resin contained on a minicolumn, where analyte ions are sorbed as 5-methyl-4-(2-thiazolylazo) resorcinol chelates. After elution using 1 mol L -1 nitric acid solution, the analytes are determinate employing flame atomic absorption spectrometry. The optimization step was performed using a full two-level factorial design and the variables studied were: pH, reagent concentration (RC) and amount of resin on the column (AR). Under the experimental conditions established in the optimization step, the procedure allows the determination of copper and nickel with limit of detection of 1.03 and 1.90 μg L -1 , respectively and precision of 7 and 8%, for concentrations of copper and nickel of 200 μg L -1 . The effect of matrix ions was also evaluated. The accuracy was confirmed by analyzing of the followings certified reference materials: NIST SRM 1515 Apple leaves and GBW 07603 Aquatic and Terrestrial Biological Products. The developed method was successfully applied for the determination of copper and nickel in real samples including human hair, chicken meat, black tea and canned fish

  18. A preconcentration system for determination of copper and nickel in water and food samples employing flame atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Tuzen, Mustafa [Department of Chemistry, Gaziosmanpasa University, 60250 Tokat (Turkey); Soylak, Mustafa [Department of Chemistry, Erciyes University, 38039 Kayseri (Turkey)], E-mail: soylak@erciyes.edu.tr; Citak, Demirhan [Department of Chemistry, Gaziosmanpasa University, 60250 Tokat (Turkey); Ferreira, Hadla S.; Korn, Maria G.A. [Universidade Federal da Bahia, Instituto de Quimica, 40170-290 Salvador (Brazil); Bezerra, Marcos A. [Universidade Estadual do Sudoeste da Bahia, 45200-190 Jequie (Brazil)

    2009-03-15

    A separation/preconcentration procedure using solid phase extraction has been proposed for the flame atomic absorption spectrometric determination of copper and nickel at trace level in food samples. The solid phase is Dowex Optipore SD-2 resin contained on a minicolumn, where analyte ions are sorbed as 5-methyl-4-(2-thiazolylazo) resorcinol chelates. After elution using 1 mol L{sup -1} nitric acid solution, the analytes are determinate employing flame atomic absorption spectrometry. The optimization step was performed using a full two-level factorial design and the variables studied were: pH, reagent concentration (RC) and amount of resin on the column (AR). Under the experimental conditions established in the optimization step, the procedure allows the determination of copper and nickel with limit of detection of 1.03 and 1.90 {mu}g L{sup -1}, respectively and precision of 7 and 8%, for concentrations of copper and nickel of 200 {mu}g L{sup -1}. The effect of matrix ions was also evaluated. The accuracy was confirmed by analyzing of the followings certified reference materials: NIST SRM 1515 Apple leaves and GBW 07603 Aquatic and Terrestrial Biological Products. The developed method was successfully applied for the determination of copper and nickel in real samples including human hair, chicken meat, black tea and canned fish.

  19. The impact of supersaturation level for oral absorption of BCS class IIb drugs, dipyridamole and ketoconazole, using in vivo predictive dissolution system: Gastrointestinal Simulator (GIS).

    Science.gov (United States)

    Tsume, Yasuhiro; Matsui, Kazuki; Searls, Amanda L; Takeuchi, Susumu; Amidon, Gregory E; Sun, Duxin; Amidon, Gordon L

    2017-05-01

    The development of formulations and the assessment of oral drug absorption for Biopharmaceutical Classification System (BCS) class IIb drugs is often a difficult issue due to the potential for supersaturation and precipitation in the gastrointestinal (GI) tract. The physiological environment in the GI tract largely influences in vivo drug dissolution rates of those drugs. Thus, those physiological factors should be incorporated into the in vitro system to better assess in vivo performance of BCS class IIb drugs. In order to predict oral bioperformance, an in vitro dissolution system with multiple compartments incorporating physiologically relevant factors would be expected to more accurately predict in vivo phenomena than a one-compartment dissolution system like USP Apparatus 2 because, for example, the pH change occurring in the human GI tract can be better replicated in a multi-compartmental platform. The Gastrointestinal Simulator (GIS) consists of three compartments, the gastric, duodenal and jejunal chambers, and is a practical in vitro dissolution apparatus to predict in vivo dissolution for oral dosage forms. This system can demonstrate supersaturation and precipitation and, therefore, has the potential to predict in vivo bioperformance of oral dosage forms where this phenomenon may occur. In this report, in vitro studies were performed with dipyridamole and ketoconazole to evaluate the precipitation rates and the relationship between the supersaturation levels and oral absorption of BCS class II weak base drugs. To evaluate the impact of observed supersaturation levels on oral absorption, a study utilizing the GIS in combination with mouse intestinal infusion was conducted. Supersaturation levels observed in the GIS enhanced dipyridamole and ketoconazole absorption in mouse, and a good correlation between their supersaturation levels and their concentration in plasma was observed. The GIS, therefore, appears to represent in vivo dissolution phenomena and

  20. Determination of the Mass Absorption Coefficient in Two-Layer Ti/V and V/Ti Thin Film Systems by the X-Ray Fluorescence Method

    Science.gov (United States)

    Mashin, N. I.; Chernyaeva, E. A.; Tumanova, A. N.; Gafarova, L. M.

    2016-03-01

    A new XRF procedure for the determination of the mass absorption coefficient in thin film Ti/V and V/Ti two-layer systems has been proposed. The procedure uses easy-to-make thin-film layers of sputtered titanium and vanadium on a polymer film substrate. Correction coefficients have been calculated that take into account attenuation of primary radiation of the X-ray tube, as well as attenuation of the spectral line of the bottom layer element in the top layer.

  1. Re-investigation of the (3, 0) band in the b4Σ- - a4Π system for nitric oxide by laser absorption spectroscopy

    Science.gov (United States)

    Li, Chuanliang; Shao, Ligang; Wang, Hailing; Zhou, Qinghong; Qiu, Xuanbing; Wei, Jilin; Deng, Lunhua; Chen, Yangqin

    2018-04-01

    Nitric oxide (NO) radicals in the a4Π state were produced by discharging the mixture of NO gas and helium at the audio frequency. In the near infrared region, the spectra of the b4Σ- - a4Π system of the NO radical were studied by optical heterodyne - concentration modulation laser absorption spectroscopy. More than one hundred and thirty lines and eleven branches were recorded for the first time and assigned to the (3, 0) band. A global fitting was carried out to extract the molecular constants. In particular, the parameters D, p, γ and AD were precisely determined.

  2. Portable sample preparation and analysis system for micron and sub-micron particle characterization using light scattering and absorption spectroscopy

    Science.gov (United States)

    Stark, Peter C [Los Alamos, NM; Zurek, Eduardo [Barranquilla, CO; Wheat, Jeffrey V [Fort Walton Beach, FL; Dunbar, John M [Santa Fe, NM; Olivares, Jose A [Los Alamos, NM; Garcia-Rubio, Luis H [Temple Terrace, FL; Ward, Michael D [Los Alamos, NM

    2011-07-26

    There is provided a method and device for remote sampling, preparation and optical interrogation of a sample using light scattering and light absorption methods. The portable device is a filtration-based device that removes interfering background particle material from the sample matrix by segregating or filtering the chosen analyte from the sample solution or matrix while allowing the interfering background particles to be pumped out of the device. The segregated analyte is then suspended in a diluent for analysis. The device is capable of calculating an initial concentration of the analyte, as well as diluting the analyte such that reliable optical measurements can be made. Suitable analytes include cells, microorganisms, bioparticles, pathogens and diseases. Sample matrixes include biological fluids such as blood and urine, as well as environmental samples including waste water.

  3. Low Z elements (Mg, Al, and Si) K-edge X-ray absorption spectroscopy in minerals and disordered systems

    International Nuclear Information System (INIS)

    Ildefonse, P.; Calas, G.; Flank, A.M.; Lagarde, P.

    1995-01-01

    Soft X-ray absorption near edge spectroscopy (XANES) and extended X-ray absorption fine structure (EXAFS) spectroscopy have been performed at the Mg-, Al- and Si-K edges in order to establish the ability of this spectroscopy to derive structural information in disordered solids such as glasses and gels. Mg- and Al-K XANES are good structural probes to determine the coordination state of these elements in important minerals, glasses and gels. In a CaO-MgO-2SiO 2 glass Mg XANES spectra differ from that found in the crystalline equivalent, with a significant shift of the edge maxima to lower energy, consistent with a CN lower than 6. Mg-EXAFS on the same sample are in agreement and indicate the presence of 5-coordinated Mg with Mg-O distances of 2.01 A. In aluminosilicate gels, Al-K XANES has been used to investigate the [4]Al/Al total ratios. These ratios increase as the Al/Si ratios decrease. Aluminosilicate and ferric-silicate gels were studied by using Si-K edge XANES. XANES spectra differ significantly among the samples studied. Aluminosilicate gels with Al/Si=1 present a different Al and Si local environment from that known in clay minerals with the same Al/Si ratio. The gel-to-mineral transformation thus implies a dissolution-recrystallization mechanism. On the contrary, ferric-silicate gel presents a Si local environment close to that found in nontronite which may be formed by a long range ordering of the initial gels. (orig.)

  4. Low Z elements (Mg, Al, and Si) K-edge X-ray absorption spectroscopy in minerals and disordered systems

    Science.gov (United States)

    Ildefonse, Ph.; Calas, G.; Flank, A. M.; Lagarde, P.

    1995-05-01

    Soft X-ray absorption near edge spectroscopy (XANES) and extended X-ray absorption fine structure (EXAFS) spectroscopy have been performed at the Mg-, Al- and Si-K edges in order to establish the ability of this spectroscopy to derive structural information in disordered solids such as glasses and gels. Mg- and Al-K XANES are good structural probes to determine the coordination state of these elements in important minerals, glasses and gels. In a CaOsbnd MgOsbnd 2SiO2 glass Mg XANES spectra differ from that found in the crystalline equivalent, with a significant shift of the edge maxima to lower energy, consistent with a CN lower than 6. Mg-EXAFS on the same sample are in agreement and indicate the presence of 5-coordinated Mg with Mgsbnd O distances of 2.01Å. In aluminosilicate gels, Alsbnd K XANES has been used to investigate the [4]Al/Altotal ratios. These ratios increase as the Al/Si ratios decrease. Aluminosilicate and ferric-silicate gels were studied by using Sisbnd K edge XANES. XANES spectra differ significantly among the samples studied. Aluminosilicate gels with Al/Si= 1 present a different Al and Si local environment from that known in clay minerals with the same Al/Si ratio. The gel-to-mineral transformation thus implies a dissolution-recrystallization mechanism. On the contrary, ferric-silicate gel presents a Si local environment close to that found in nontronite which may be formed by a long range ordering of the initial gels.

  5. Properties of light absorption in a highly coloured estuarine system in south-east Australia which is prone to blooms of the toxic dinoflagellate Gymnodinium catenatum

    Science.gov (United States)

    Clementson, Lesley A.; Parslow, John S.; Turnbull, Alison R.; Bonham, Pru I.

    2004-05-01

    The Huon Estuary in south-east Tasmania is an important site in Australia's aquaculture and finfish industries. Atlantic salmon and shellfish are farmed in the Huon River Estuary, which drains a catchment that includes both areas of pristine wilderness and agriculture. The estuary experiences algal blooms, including blooms of the toxic dinoflagellate Gymnodinium catenatum, which can cause considerable problems for the aquaculture industry. The freshwater input is highly coloured due to high levels of humic material and this combined with intrusions of clearer oceanic water and the occurrence of algal blooms makes this estuary optically complex. Between November 1996 and September 1998 samples for pigment and optical analyses were collected weekly from five sites within the mid to lower regions of the estuary. In addition, every three months (beginning July 1996), samples were collected from 30 sites within the full river/estuary system. Early in December 1997 a bloom of Gymnodinium catenatum occurred throughout the estuary and persisted until June 1998. Chromophoric dissolved organic matter (CDOM) was found to dominate the total absorption of the water throughout the entire estuary and over the two-year duration of the study. The occurrence of algal blooms showed no correlation with the optical characteristics of the estuary, suggesting that optical parameters cannot be used to predict the occurrence of algal blooms in this estuary. Blooms of different algal species, such as diatoms and dinoflagellates, may be able to be distinguished by their absorption spectra in the UV region rather than the visible region. To date, this study is the most detailed spatial and temporal study of the characteristics of light absorption in an estuarine system within Australia.

  6. Spectral intensities for stoichiometric elpasolites. I. Absorption and emission of Tm+3 in systems of the Cs2NaTmZ6 type

    International Nuclear Information System (INIS)

    Acevedo, R; Poblete, V; Pozo, J; Elgueta, R; Tanner, P.A

    2000-01-01

    Based upon new experimental data for systems such as, Cs 2 NaTmZ 6 , where Z - =Cl - , F - [1-4], we have carried out a thorough study of the mechanistic factors related with the spectral intensities for both the absorptions and the emissions of the Cs 2 NaTmZ 6 system. For the above purposes, we have generalized our previous calculation models, and in this article we show novel results for the emissions 3 H 4 (Γ i )→ 3 F 4 (Γ j ) and for the absorptions 3 H 6 (A 1 )→ 3 F 4 (Γ i ), 1 G 4 (Γ i ), 3 H 5 (Γ i ), with Γ-k(k=i,j)=A 1 ,E,T 1 ,T 2 and Γ 1 =T a 1 , T b 1 , E, T 2 . The effects due to dispersion (essentially, electrostatic in character), details of the short range vibrational force field and Jahn-Teller distortion are discussed in the text. The agreement among experiment and theory is satisfactory and a generalized model with a few number of adjustable parameters is introduced to account for the observed spectral intensities

  7. Performance Analysis of Spectral-Phase-Encoded Optical CDMA System Using Two-Photon-Absorption Receiver Structure for Asynchronous and Slot-Level Synchronous Transmitters

    Science.gov (United States)

    Jamshidi, Kambiz; Salehi, Jawad A.

    2007-06-01

    In this paper, we analyze the performance of a nonlinear two-photon-absorption (TPA) receiver and compare its performance with that of a single-photon-absorption (SPA) receiver in the context of spectral-phase-encoded optical code-division multiple access (CDMA) technique. The performances for the above systems are evaluated for two different transmission scenarios, namely, asynchronous and slot-level synchronous transmitters. Performance evaluation includes different sources of degradation such as multiple-access interference, noise due to optical amplification, shot noise, and thermal noise. In obtaining the performance, the mean and variance of the received signal in each of the above techniques are derived, and bit error rate is obtained using Gaussian approximation. In general, it is shown that TPA receivers are superior in performance with respect to SPA receivers when the receiver employs a much slower photodetector in comparison with the laser's transmitted pulse duration. This, indeed, is the reason behind the choice of nonlinear receivers, such as TPA, in most spectral-phase-encoded optical CDMA systems.

  8. A study of the Nb3Ge system by Ge K-edge extended x-ray absorption fine structure and x-ray absorption near-edge structure spectroscopy

    International Nuclear Information System (INIS)

    Saini, N L; Filippi, M; Wu Ziyu; Oyanagi, H; Ihara, H; Iyo, A; Agrestini, S; Bianconi, A

    2002-01-01

    The local structure of Nb 3 Ge intermetallic superconductor has been studied by Ge K-edge absorption spectroscopy. Extended x-ray absorption fine structure (EXAFS) experiments show two Ge-Nb distances. In addition to the crystallographic distance of ∼2.87 A, there exists a second Ge-Nb distance, shorter than the first by ∼0.2 A, assigned to a phase with short-range symmetry related to local displacements in the Nb-Nb chains. The x-ray absorption near-edge structure (XANES) spectrum has been simulated by full multiple-scattering calculations considering the local displacements determined by the EXAFS analysis. The XANES spectrum has been well reproduced by considering a cluster of 99 atoms within a radius of about 7 A from the central Ge atom and introducing determined local displacements

  9. Ultrasonic absorption in solid specimens

    International Nuclear Information System (INIS)

    Siwabessy, P.J. W.; Stewart, G.A.

    1996-01-01

    As part of a project to measure the absorption of high frequency (50 - 500 kHz) sonar signals in warm sea-water, a laboratory apparatus has been constructed and tested against room temperature distilled water and various solutions of MgSO 4 (chemical relaxation of MgSO 4 is the major contribution to absorption below 200 kHz). The technique involves monitoring the decay of an acoustic signal for different sizes of vessels of water suspended in an evacuated chamber. So far, all containing vessels used have been spherical in shape. Extrapolation of the results to infinite volume yields the absorption due to the water alone. In order to accommodate variations in temperature and pressure, and to make the system more robust (e.g. for ship deck usage), it is desirable to employ stainless steel vessels. However, it was found that the quality of the data was greatly improved when pyrex glass spheres were used. The stainless steel spheres were manufactured by welding together mechanically spun hemispheres. The linear frequency dependence characteristic of acoustic absorption in solids was observed (in contrast to the quadratic frequency dependence of acoustic absorption in water), and the acoustic absorption was found to depend strongly on the thermal history of the steel

  10. Application of the correction's system of bottom by deuterium's lamp of a spectrophotometer of atomic absorption to the obtaining of ultraviolet spectrums

    International Nuclear Information System (INIS)

    Villalobos Chaves, Alberto Enrique

    2002-01-01

    The correction system of bottom by lamp of deuterium's arch of a spectrophotometer of atomic absorption has been utilized with sweep's capacity of wavelength to get spectrums of ultraviolet absorption of samples in gaseous phase, whether in presence as in absence of flame, in the region between 200 nm and 365 nm. The spectral information was obtained after of a process of electronic subtraction of the source's signal, except for the source's signal plus the sample and its subsequent analysis by a programmed data's processor to give a report in terms of wavelength. The spectrums obtained in absence of flame were practiced in samples contained in a gas's sell for infrared spectroscopy with polyethylene's windows, it is located of the burner and directly in front to the radiation's beam, comparable spectrums with the reported in the literature were obtained and with a bigger resolution than the measure with an conventional ultraviolet absorption's spectrophotometer utilized like reference. The spectrums in presence of flame have been of flame have been obtained from dissolved samples and directly suctioned, it achieves to obtain spectral information that is normally not detected conveniently when it performs qualitative analysis by emission of flame in elements such like zinc, lead, cobalt, mercury and nickel among other. The information obtained on this way has been utilized like an alternative method to the elemental analysis by humid way with a view to increase the reliability of the results that have been utilized like basis in the determination of the tariff classification of imported or exported products. (Author) [es

  11. D-xylose absorption

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003606.htm D-xylose absorption To use the sharing features on this page, please enable JavaScript. D-xylose absorption is a laboratory test to determine ...

  12. Flow injection analysis-flame atomic absorption spectrometry system for indirect determination of cyanide using cadmium carbonate as a new solid-phase reactor

    International Nuclear Information System (INIS)

    Noroozifar, M.; Khorasani-Motlagh, M.; Hosseini, S.-N.

    2005-01-01

    A new and simple flow injection system procedure has been developed for the indirect determination of cyanide. The method is based on insertion of aqueous cyanide solutions into an on-line cadmium carbonate packed column (25% m/m suspended on silica gel beads) and a sodium hydroxide with pH 10 is used as the carrier stream. The eluent containing the analyte as cadmiumcyanide complexes, produced from reaction between cadmium carbonate and cyanide, measured by flame atomic absorption spectrometry. The absorbance is proportional to the concentration of cyanide in the sample. The linear range of the system is up to 15 mg L -1 with a detection limit 0.2 mg L -1 and sampling rate 72 h -1 . The method is suitable for determination of cyanide in industrial waste waters with a relative standard deviation better than 1.22%

  13. Absorption and excretion tests

    International Nuclear Information System (INIS)

    Berberich, R.

    1988-01-01

    The absorption and excretion of radiopharmaceuticals is still of interest in diagnostic investigations of nuclear medicine. In this paper the most common methods of measuring absorption and excretion are described. The performance of the different tests and their standard values are discussed. More over the basic possibilities of measuring absorption and excretion including the needed measurement equipments are presented. (orig.) [de

  14. Thermo-economic and environmental analyses based multi-objective optimization of vapor compression–absorption cascaded refrigeration system using NSGA-II technique

    International Nuclear Information System (INIS)

    Jain, Vaibhav; Sachdeva, Gulshan; Kachhwaha, Surendra Singh; Patel, Bhavesh

    2016-01-01

    Highlights: • It addresses multi-objective optimization study on cascaded refrigeration system. • Cascaded system is a promising decarburizing and energy efficient technology. • NSGA-II technique is used for multi-objective optimization. • Total annual product cost and irreversibility rate are simultaneously optimized. - Abstract: Present work optimizes the performance of 170 kW vapor compression–absorption cascaded refrigeration system (VCACRS) based on combined thermodynamic, economic and environmental parameters using Non-dominated Sort Genetic Algorithm-II (NSGA-II) technique. Two objective functions including the total irreversibility rate (as a thermodynamic criterion) and the total product cost (as an economic criterion) of the system are considered simultaneously for multi-objective optimization of VCACRS. The capital and maintenance costs of the system components, the operational cost, and the penalty cost due to CO_2 emission are included in the total product cost of the system. Three optimized systems including a single-objective thermodynamic optimized, a single-objective economic optimized and a multi-objective optimized are analyzed and compared. The results showed that the multi-objective design considers the combined thermodynamic and total product cost criteria better than the two individual single-objective thermodynamic and total product cost optimized designs.

  15. Modeling and numerical simulation of a novel solar-powered absorption air conditioning system driven by a bubble pump with energy storage

    Institute of Scientific and Technical Information of China (English)

    QIU Jia; LIANG Jian; CHEN GuangMing; DU RuXu

    2009-01-01

    This paper presents a novel solar-powered absorption air conditioning system driven by a bubble pump with energy storage. It solves the problem of unreliable solar energy supply by storing the working fluids and hence, functions 24 h per day. First, the working principles are described and the dynamic models for the primary energy storage components are developed. Then, the system is evaluated based on a numerical simulation. Based on the meteorological data of a typical day in a subtropical area, with the area of a solar collector being set at 19.15 m2, whilst the initial charging mass, mass fraction and temperature of the solution are respectively set at 379.5 kg, 54.16% and 34.5 ℃, it is found that the respective coefficients of performance (COP) of the air conditioning system and the en-tire system (including the solar panel) are 0.7771 and 0.4372. In particular, the energy storage density of the system is 206.69 MJ/m3 which is much greater than those of chilled water or hot water storage systems under comparable conditions. This makes the new system much more compact and efficient. Finally, an automatic control strategy is given to achieve the highest COP when solar energy fluctuates.

  16. The use of absorption refrigeration systems in combined cycle power plants; Empleo de sistemas de refrigeracion por absorcion en plantas de ciclo combinado

    Energy Technology Data Exchange (ETDEWEB)

    Romero Paredes, H.; Ambriz, J.J.; Vargas, M.; Godinez, M.; Gomez, F.; Valdez, L.; Pantoja, G. [Universidad Autonoma Metropolitana, Unidad Iztapalapa, Departamento de Ingenieria de Procesos e Hidraulica, Mexico D. F. (Mexico)

    1995-12-31

    Day after day the electric power generation tends to be done in the most efficient way in order to diminish the generation costs and the rate of environmental pollution per KWh generated. This paper discusses the application of absorption refrigeration systems for the cooling of the air entering the compressor of a gas turbine in a combined cycle, in order to increase the mass air flow and with it the turbine output. The flows with remanent energy content that are not used in a combined cycle can be used for the operation of the absorption refrigeration system. This way, the required thermal energy for the cooling system is free. With this system it is possible to raise the gas turbine generation output from 5% to 25%. [Espanol] La generacion electrica dia con dia pretende realizarse de la manera mas eficiente posible con el objeto de disminuir los costos de generacion y la tasa de contaminacion ambiental por Kwh generado. En el presente trabajo se introduce la aplicacion de sistemas de refrigeracion por absorcion para el enfriamiento del aire de entrada al compresor de la turbina de gas de un ciclo combinado, con el objeto de aumentar el flujo masico del aire y con ello la potencia de salida de la turbina. Las corrientes con contenido remanente de energia termica que no se usan en una planta de ciclo combinado pueden servir para operar el sistema de refrigeracion por absorcion. De esta manera, la energia termica requerida para el sistema de enfriamiento es gratuita. Con este sistema es posible incrementar la potencia de generacion de la turbina de gas de 5 a 25%.

  17. The use of absorption refrigeration systems in combined cycle power plants; Empleo de sistemas de refrigeracion por absorcion en plantas de ciclo combinado

    Energy Technology Data Exchange (ETDEWEB)

    Romero Paredes, H; Ambriz, J J; Vargas, M; Godinez, M; Gomez, F; Valdez, L; Pantoja, G [Universidad Autonoma Metropolitana, Unidad Iztapalapa, Departamento de Ingenieria de Procesos e Hidraulica, Mexico D. F. (Mexico)

    1996-12-31

    Day after day the electric power generation tends to be done in the most efficient way in order to diminish the generation costs and the rate of environmental pollution per KWh generated. This paper discusses the application of absorption refrigeration systems for the cooling of the air entering the compressor of a gas turbine in a combined cycle, in order to increase the mass air flow and with it the turbine output. The flows with remanent energy content that are not used in a combined cycle can be used for the operation of the absorption refrigeration system. This way, the required thermal energy for the cooling system is free. With this system it is possible to raise the gas turbine generation output from 5% to 25%. [Espanol] La generacion electrica dia con dia pretende realizarse de la manera mas eficiente posible con el objeto de disminuir los costos de generacion y la tasa de contaminacion ambiental por Kwh generado. En el presente trabajo se introduce la aplicacion de sistemas de refrigeracion por absorcion para el enfriamiento del aire de entrada al compresor de la turbina de gas de un ciclo combinado, con el objeto de aumentar el flujo masico del aire y con ello la potencia de salida de la turbina. Las corrientes con contenido remanente de energia termica que no se usan en una planta de ciclo combinado pueden servir para operar el sistema de refrigeracion por absorcion. De esta manera, la energia termica requerida para el sistema de enfriamiento es gratuita. Con este sistema es posible incrementar la potencia de generacion de la turbina de gas de 5 a 25%.

  18. A Novel Self-Microemulsifying System for the Simultaneous Delivery and Enhanced Oral Absorption of Curcumin and Resveratrol.

    Science.gov (United States)

    Jaisamut, Patcharawalai; Wiwattanawongsa, Kamonthip; Wiwattanapatapee, Ruedeekorn

    2017-03-01

    The use of curcumin and resveratrol in combination has now become increasingly of interest because of their synergistic effects as therapeutic agents for various diseases, especially cancer. To overcome the poor oral bioavailability of both compounds and improve patient compliance, a novel self-microemulsifying formulation containing curcumin together with resveratrol was developed. Capryol 90, Cremophor EL, and Labrasol were selected as the oil, surfactant, and co-surfactant in the formulation, respectively, based on the solubility study of both compounds. More than 70 % and 80 % of curcumin and resveratrol, respectively, were released in 20 min. The formulation formed a fine oil in water microemulsion with droplet sizes in aqueous media of 15-20 nm. In addition, the formulation containing curcumin and resveratrol showed greater antioxidant activity than that of the formulations with individual compounds, while the cytotoxic activity against HT-29 of the co-formulation (IC 50  = 18.25 µM; curcumin and resveratrol in the ratio 1 : 1) was less than the formulation with only curcumin (IC 50  = 30.1 µM) and only resveratrol (IC 50  = 25.4 µM). After oral administration to rabbits, the self-microemulsifying formulation containing curcumin together with resveratrol increased the total plasma concentrations of curcumin and resveratrol by 10-fold and 6-fold, respectively, compared to the unformulated combination. This study clearly demonstrated the potential use of the self-microemulsifying formulation for co-delivery, and enhanced oral absorption of poorly water-soluble natural compounds. In addition, the combination was found to produce synergistic antioxidant activity and cytotoxicity against HT-29 cells. Georg Thieme Verlag KG Stuttgart · New York.

  19. Improved spectral absorption coefficient grouping strategy of wide band k-distribution model used for calculation of infrared remote sensing signal of hot exhaust systems

    Science.gov (United States)

    Hu, Haiyang; Wang, Qiang

    2018-07-01

    A new strategy for grouping spectral absorption coefficients, considering the influences of both temperature and species mole ratio inhomogeneities on correlated-k characteristics of the spectra of gas mixtures, has been deduced to match the calculation method of spectral overlap parameter used in multiscale multigroup wide band k-distribution model. By comparison with current spectral absorption coefficient grouping strategies, for which only the influence of temperature inhomogeneity on the correlated-k characteristics of spectra of single species was considered, the improvements in calculation accuracies resulting from the new grouping strategy were evaluated using a series of 0D cases in which radiance under 3-5-μm wave band emitted by hot combustion gas of hydrocarbon fuel was attenuated by atmosphere with quite different temperature and mole ratios of water vapor and carbon monoxide to carbon dioxide. Finally, evaluations are presented on the calculation of remote sensing thermal images of transonic hot jet exhausted from a chevron ejecting nozzle with solid wall cooling system.

  20. Control of one- and two-photon absorption in a four-level atomic system by changing the amplitude and phase of a driving microwave field

    International Nuclear Information System (INIS)

    Hou, B P; Wang, S J; Yu, W L; Sun, W L

    2005-01-01

    We consider the one- and two-photon absorption spectra of a four-level Y-type atom with the two highest lying levels driven by a microwave field. We found that in the one-photon absorption case, the microwave field can lead to the probe gain, and the absorption and gain spectral structures depend strongly on the microwave field amplitude. For the two-photon absorption case, the strong microwave field can enhance the absorption. When the microwave field amplitude is reduced to a certain value, the single absorption peak in the two-photon spectrum changes into a structure of two-peak structure with different magnitudes. Moreover, the one- and two-photon absorption spectra can be modulated by the phase of the microwave field which produces a closed-loop configuration. Finally, we use the analytic solutions in terms of dressed-state basis to explain the results from our numerical calculation

  1. Extraction and preconcentration of trace levels of cobalt using functionalized magnetic nanoparticles in a sequential injection lab-on-valve system with detection by electrothermal atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Wang Yang; Luo Xiaoyu; Tang Jie; Hu Xiaoya; Xu Qin; Yang Chun

    2012-01-01

    Graphical abstract: An approach to performing extraction and preconcentration employing functionalized magnetic particles for the determination of cobalt in the sequential injection lab-on-valve system using detection by electrothermal atomic absorption spectrometry. Highlights: ► New SPE method for cobalt separation/preconcentration was reported. ► Functionalized magnetic nanoparticles were used as adsorbent. ► Extraction, elution, and detection procedures were performed in the LOV system. ► This automatic extraction technique provided a good platform for metal analysis. - Abstract: A new approach to performing extraction and preconcentration employing functionalized magnetic nanoparticles for the determination of trace metals is presented. Alumina-coated iron oxide nanoparticles were synthesized and used as the solid support. The nanoparticles were functionalized with sodium dodecyl sulfate and used as adsorbents for solid phase extraction of the analyte. Extraction, elution, and detection procedures were performed sequentially in the sequential injection lab-on-valve (SI-LOV) system followed by electrothermal atomic absorption spectrometry (ETAAS). Mixtures of hydrophobic analytes were successfully extracted from solution using the synthesized magnetic adsorbents. The potential use of the established scheme was demonstrated by taking cobalt as a model analyte. Under the optimal conditions, the calibration curve showed an excellent linearity in the concentration range of 0.01–5 μg L −1 , and the relative standard deviation was 2.8% at the 0.5 μg L −1 level (n = 11). The limit of detection was 6 ng L −1 with a sampling frequency of 18 h −1 . The present method has been successfully applied to cobalt determination in water samples and two certified reference materials.

  2. Calcium absorption and achlorhydria

    International Nuclear Information System (INIS)

    Recker, R.R.

    1985-01-01

    Defective absorption of calcium has been thought to exist in patients with achlorhydria. The author compared absorption of calcium in its carbonate form with that in a pH-adjusted citrate form in a group of 11 fasting patients with achlorhydria and in 9 fasting normal subjects. Fractional calcium absorption was measured by a modified double-isotope procedure with 0.25 g of calcium used as the carrier. Mean calcium absorption (+/- S.D.) in the patients with achlorhydria was 0.452 +/- 0.125 for citrate and 0.042 +/- 0.021 for carbonate (P less than 0.0001). Fractional calcium absorption in the normal subjects was 0.243 +/- 0.049 for citrate and 0.225 +/- 0.108 for carbonate (not significant). Absorption of calcium from carbonate in patients with achlorhydria was significantly lower than in the normal subjects and was lower than absorption from citrate in either group; absorption from citrate in those with achlorhydria was significantly higher than in the normal subjects, as well as higher than absorption from carbonate in either group. Administration of calcium carbonate as part of a normal breakfast resulted in completely normal absorption in the achlorhydric subjects. These results indicate that calcium absorption from carbonate is impaired in achlorhydria under fasting conditions. Since achlorhydria is common in older persons, calcium carbonate may not be the ideal dietary supplement

  3. An Automatic System for Determining Solar Absorptance and Thermal Emittance of Surfaces from Spectral Normal Reflectance Measurements

    National Research Council Canada - National Science Library

    Teichman, Louis

    1965-01-01

    .... The system consists of two spectrophotometers used to make optical reflectance measurements, electronic digitizing equipment to record the data, and a high-speed electronic computer to calculate the desired results...

  4. Aspects on modeled and the design of a system of refrigeration by absorption attended with solar energy; Aspectos sobre el modelado y diseno de un sistema de refrigeracion por absorcion asistido con energia solar

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Cascales, J. R.; Vera Garcia, F.; Cano Izquierdo, J. M.; Delgado Marin, J. P.; Martinez Sanchez, R.

    2008-07-01

    In this paper, we study the global modelling of an absorption system working with Br Li-H{sub 2}O. It satisfies the air-conditioning necessities of a classroom in an educational centre in Puerto Lumbreras. Murcia. This system utilises a set of solar collector to satisfy the thermal necessities of the vapour generator in the absorption system. For the dynamical simulation of the system we have used the TRNSYS software. The air-conditioned place has been modelled by using a TRNSYS module called PREBID. In this work, special attention is paid to the absorption equipment model developed by using neural networks which has been implemented in TRNSYS. The paper is closed drawing some conclusions. (Author)

  5. Development and operation of a real-time data acquisition system for the NASA, Langley Research Center Differential Absorption Lidar

    Science.gov (United States)

    Butler, C.; Kindle, E. C.

    1984-01-01

    The capabilities of the DIAL data acquisition system (DAS) for the remote measurement of atmospheric trace gas concentrations from ground and aircraft platforms were extended through the purchase and integration of other hardware and the implementation of improved software. An operational manual for the current system is presented. Hardware and peripheral device registers are outlined only as an aid in debugging any DAS problems which may arise.

  6. Analyzing Water's Optical Absorption

    Science.gov (United States)

    2002-01-01

    A cooperative agreement between World Precision Instruments (WPI), Inc., and Stennis Space Center has led the UltraPath(TM) device, which provides a more efficient method for analyzing the optical absorption of water samples at sea. UltraPath is a unique, high-performance absorbance spectrophotometer with user-selectable light path lengths. It is an ideal tool for any study requiring precise and highly sensitive spectroscopic determination of analytes, either in the laboratory or the field. As a low-cost, rugged, and portable system capable of high- sensitivity measurements in widely divergent waters, UltraPath will help scientists examine the role that coastal ocean environments play in the global carbon cycle. UltraPath(TM) is a trademark of World Precision Instruments, Inc. LWCC(TM) is a trademark of World Precision Instruments, Inc.

  7. [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.

  8. Lateral vibration behavior analysis and TLD vibration absorption design of the soft yoke single-point mooring system

    Science.gov (United States)

    Lyu, Bai-cheng; Wu, Wen-hua; Yao, Wei-an; Du, Yu

    2017-06-01

    Mooring system is the key equipment of FPSO safe operation. The soft yoke mooring system is regarded as one of the best shallow water mooring strategies and widely applied to the oil exploitation in the Bohai Bay in China and the Gulf of Mexico. Based on the analysis of numerous monitoring data obtained by the prototype monitoring system of one FPSO in the Bohai Bay, the on-site lateral vibration behaviors found on the site of the soft yoke subject to wave load were analyzed. ADAMS simulation and model experiment were utilized to analyze the soft yoke lateral vibration and it was determined that lateral vibration was resonance behaviors caused by wave excitation. On the basis of the soft yoke longitudinal restoring force being guaranteed, a TLD-based vibration damper system was constructed and the vibration reduction experiments with multi-tank space and multi-load conditions were developed. The experimental results demonstrated that the proposed TLD vibration reduction system can effectively reduce lateral vibration of soft yoke structures.

  9. Absorption properties of identical atoms

    International Nuclear Information System (INIS)

    Sancho, Pedro

    2013-01-01

    Emission rates and other optical properties of multi-particle systems in collective and entangled states differ from those in product ones. We show the existence of similar effects in the absorption probabilities for (anti)symmetrized states of two identical atoms. The effects strongly depend on the overlapping between the atoms and differ for bosons and fermions. We propose a viable experimental verification of these ideas. -- Highlights: •The absorption rates of a pair of identical atoms in product and (anti)symmetrized states are different. •The modifications of the optical properties are essentially determined by the overlapping between the atoms. •The absorption properties differ, in some cases, for bosons and fermions

  10. Numerical simulation and experimental results of horizontal tube falling film generator working in a NH3-LiNO3 absorption refrigeration system

    International Nuclear Information System (INIS)

    Herrera, J.V.; Garcia-Valladares, O.; Gomez, V.H.; Best, R.

    2010-01-01

    This paper describes the work made at the Centro de Investigacion en Energia in the development of an absorption refrigeration system for cooling and refrigeration applications with a capacity of 10 kW. The single effect unit utilizes ammonia-lithium nitrate as working pair and it is air cooled. The generator is a falling film type with horizontal tubes where the heating oil flows inside the tube bank and the ammonia-lithium nitrate solution flows as a falling film on the tube outside, where it is heated and ammonia vapor is generated. The generator consists of tree columns and four rows per column of horizontal tubes. The system was tested at controlled conditions with heating oil obtained from an electric resistance heating loop. A numerical model of the horizontal falling film generator was developed that divided the system into three different thermal elements: the flow inside the tube, the heat conduction in the tube wall and the falling film solution flow. The mathematical model was tested and validated with experimental data and a study of the influence of the heat transfer coefficient for ammonia-lithium nitrate solution in the numerical model was carried out. A comparison between experimental and numerical data for the heat flux in the system and the temperature profiles in the oil and solution flows shown a good degree of correlation.

  11. Human systemic exposure to [14C]-paraphenylenediamine-containing oxidative hair dyes: Absorption, kinetics, metabolism, excretion and safety assessment

    NARCIS (Netherlands)

    Nohynek, G.J.; Skare, J.A.; Meuling, W.J.A.; Wehmeyer, K.R.; Bie, A.T.H.J. de; Vaes, W.H.J.; Dufour, E.K.; Fautz, R.; Steiling, W.; Bramante, M.; Toutain, H.

    2015-01-01

    Systemic exposure was measured in humans after hair dyeing with oxidative hair dyes containing 2.0% (A) or 1.0% (B) [14C]-p-phenylenediamine (PPD). Hair was dyed, rinsed, dried, clipped and shaved; blood and urine samples were collected for 48 hours after application. [14C] was measured in all

  12. Effect of Moisture Exchange on Interface Formation in the Repair System Studied by X-ray Absorption

    NARCIS (Netherlands)

    Lukovic, M.; Ye, G.

    2015-01-01

    In concrete repair systems, material properties of the repair material and the interface are greatly influenced by the moisture exchange between the repair material and the substrate. If the substrate is dry, it can absorb water from the repair material and reduce its effective water-to-cement ratio

  13. A general enhancement factor model for absorption and desorption systems: A CO2 capture case-study

    DEFF Research Database (Denmark)

    Gaspar, Jozsef; Fosbøl, Philip Loldrup

    2015-01-01

    kinetics and applied for the CO2-MEA-H2O second order reversible system. The results show that the GM predicts the two-film theory within 2% accuracy and the surface renewal model within 10% accuracy, both at absorber and desorber conditions and for high driving force and pinch conditions. GM is compared...

  14. Thermodynamic performance analysis of a novel electricity-heating cogeneration system (EHCS) based on absorption heat pump applied in the coal-fired power plant

    International Nuclear Information System (INIS)

    Zhang, Hongsheng; Li, Zhenlin; Zhao, Hongbin

    2015-01-01

    Highlights: • Presented a novel waste heat recovery method for Combined Heat and Power system. • Established models of the integrated system based on energy and exergy analysis. • Adopted both design and actual data ensuring the reliability of analysis results. - Abstract: A novel electricity-heating cogeneration system (EHCS) which is equipped with an absorption heat pump (AHP) system to recover waste heat from exhaust steam of the steam turbines in coal-fired thermal power plants is proposed to reduce heating energy consumption and improve the utilization of the fossil fuels in existing CHP (Combined Heat and Power) systems. According to the first and second thermodynamic law, the changes of the performance evaluation indicators are analyzed, and exergy analyses for key components of the system are carried out as well as changes of exergy indexes focusing on 135 MW direct air cooling units before and after modification. Compared with the conventional heating system, the output power increases by about 3.58 MW, gross coal consumption rate and total exergy loss respectively reduces by 11.50 g/kW h and 4.649 MW, while the total thermal and exergy efficiency increases by 1.26% and 1.45% in the EHCS when the heating load is 99,918 kJ at 75% THA condition. Meanwhile, the decrement of total exergy loss and increment of total exergy efficiency increase with the increasing of the heating load. The scheme cannot only bring great economic benefits but also save fossil resources, which has a promising market application potential.

  15. Maximum Exergetic Efficiency Operation of a Solar Powered H2O-LiBr Absorption Cooling System

    Directory of Open Access Journals (Sweden)

    Camelia Stanciu

    2017-12-01

    Full Text Available A solar driven cooling system consisting of a single effect H2O-LiBr absorbtion cooling module (ACS, a parabolic trough collector (PTC, and a storage tank (ST module is analyzed during one full day operation. The pressurized water is used to transfer heat from PTC to ST and to feed the ACS desorber. The system is constrained to operate at the maximum ACS exergetic efficiency, under a time dependent cooling load computed on 15 July for a one storey house located near Bucharest, Romania. To set up the solar assembly, two commercial PTCs were selected, namely PT1-IST and PTC 1800 Solitem, and a single unit ST was initially considered. The mathematical model, relying on the energy balance equations, was coded under Engineering Equation Solver (EES environment. The solar data were obtained from the Meteonorm database. The numerical simulations proved that the system cannot cover the imposed cooling load all day long, due to the large variation of water temperature inside the ST. By splitting the ST into two units, the results revealed that the PT1-IST collector only drives the ACS between 9 am and 4:30 pm, while the PTC 1800 one covers the entire cooling period (9 am–6 pm for optimum ST capacities of 90 kg/90 kg and 90 kg/140 kg, respectively.

  16. Thermodynamic performance optimization of the absorption-generation process in an absorption refrigeration cycle

    International Nuclear Information System (INIS)

    Chen, Yi; Han, Wei; Jin, Hongguang

    2016-01-01

    Highlights: • This paper proposes a new thermal compressor model with boost pressure ratio. • The proposed model is an effective way to optimize the absorption-generation process. • Boost pressure ratio is a key parameter in the proposed thermal compressor model. • The optimum boost pressure ratios for two typical refrigeration systems are obtained. - Abstract: The absorption refrigeration cycle is a basic cycle that establishes the systems for utilizing mid-low temperature heat sources. A new thermal compressor model with a key parameter of boost pressure ratio is proposed to optimize the absorption-generation process. The ultimate generation pressure and boost pressure ratio are used to represent the potential and operating conditions of the thermal compressor, respectively. Using the proposed thermal compressor model, the operation mechanism and requirements of the absorption refrigeration system and absorption-compression refrigeration system are elucidated. Furthermore, the two typical heat conversion systems are optimized based on the thermal compressor model. The optimum boost pressure ratios of the absorption refrigeration system and the absorption-compression refrigeration system are 0.5 and 0.75, respectively. For the absorption refrigeration system, the optimum generation temperature is 125.31 °C at the cooling water temperature of 30 °C, which is obtained by simple thermodynamic calculation. The optimized thermodynamic performance of the absorption-compression refrigeration system is 16.7% higher than that of the conventional absorption refrigeration system when the generation temperature is 100 °C. The thermal compressor model proposed in this paper is an effective method for simplifying the optimization of the thermodynamic systems involving an absorption-generation process.

  17. Determination of antimony by electrochemical hydride generation atomic absorption spectrometry in samples with high iron content using chelating resins as on-line removal system

    International Nuclear Information System (INIS)

    Bolea, E.; Arroyo, D.; Laborda, F.; Castillo, J.R.

    2006-01-01

    A method for the removal of the interference caused by iron on electrochemical generation of stibine is proposed. It consists of a chelating resin Chelex 100 column integrated into a flow injection system and coupled to the electrochemical hydride generator quartz tube atomic absorption spectrometer (EcHG-QT-AAS). Iron, as Fe(II), is retained in the column with high efficiency, close to 99.9% under optimal conditions. No significant retention was observed for Sb(III) under same conditions and a 97 ± 5% signal recovery was achieved. An electrochemical hydride generator with a concentric configuration and a reticulated vitreous carbon cathode was employed. The system is able to determine antimony concentrations in the range of ng ml -1 in presence of iron concentrations up to 400 mg l -1 . The procedure was validated by analyzing PACS-2 marine sediments reference material with a 4% (w/w) iron content and a [Fe]:[Sb] ratio of 4000:1, which caused total antimony signal suppression on the electrochemical hydride generation system. A compost sample with high iron content (0.7%, w/w), was also analyzed. A good agreement was found on both samples with the certified value and the antimony concentration determined by ICP-MS, respectively

  18. Automated magnetic sorbent extraction based on octadecylsilane functionalized maghemite magnetic particles in a sequential injection system coupled with electrothermal atomic absorption spectrometry for metal determination.

    Science.gov (United States)

    Giakisikli, Georgia; Anthemidis, Aristidis N

    2013-06-15

    A new automatic sequential injection (SI) system for on-line magnetic sorbent extraction coupled with electrothermal atomic absorption spectrometry (ETAAS) has been successfully developed for metal determination. In this work, we reported effective on-line immobilization of magnetic silica particles into a microcolumn by the external force of two strong neodymium iron boron (NdFeB) magnets across it, avoiding the use of frits. Octadecylsilane functionalized maghemite magnetic particles were used as sorbent material. The potentials of the system were demonstrated for trace cadmium determination in water samples. The method was based on the on-line complex formation with diethyldithiocarbamate (DDTC), retention of Cd-DDTC on the surface of the MPs and elution with isobutyl methyl ketone (IBMK). The formation mechanism of the magnetic solid phase packed column and all critical parameters (chemical, flow, graphite furnace) influencing the performance of the system were optimized and offered good analytical characteristics. For 5 mL sample volume, a detection limit of 3 ng L(-1), a relative standard deviation of 3.9% at 50 ng L(-1) level (n=11) and a linear range of 9-350 ng L(-1) were obtained. The column remained stable for more than 600 cycles keeping the cost down in routine analysis. The proposed method was evaluated by analyzing certified reference materials and natural waters. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. Numerical and experimental analysis of a thin liquid film on a rotating disk related to development of a spacecraft absorption cooling system

    Science.gov (United States)

    Faghri, Amir; Swanson, Theodore D.

    1989-01-01

    The numerical and experimental analysis of a thin liquid film on a rotating and a stationary disk related to the development of an absorber unit for a high capacity spacecraft absorption cooling system, is described. The creation of artificial gravity by the use of a centrifugal field was focused upon in this report. Areas covered include: (1) One-dimensional computation of thin liquid film flows; (2) Experimental measurement of film height and visualization of flow; (3) Two-dimensional computation of the free surface flow of a thin liquid film using a pressure optimization method; (4) Computation of heat transfer in two-dimensional thin film flow; (5) Development of a new computational methodology for the free surface flows using a permeable wall; (6) Analysis of fluid flow and heat transfer in a thin film in the presence and absence of gravity; and (7) Comparison of theoretical prediction and experimental data. The basic phenomena related to fluid flow and heat transfer on rotating systems reported here can also be applied to other areas of space systems.

  20. Active Stand-off Detection of Gas Leaks Using a Short Range Hard-target Backscatter Differential Optical Absorption System Based on a Quantum Cascade Laser Transmitter

    Science.gov (United States)

    Diaz, Adrian; Thomas, Benjamin; Castillo, Paulo; Gross, Barry; Moshary, Fred

    2016-06-01

    Fugitive gas emissions from agricultural or industrial plants and gas pipelines are an important environmental concern as they can contribute to the global increase of greenhouse gas concentration. Moreover, they are also a security and safety concern because of possible risk of fire/explosion or toxicity. This study presents gas concentration measurements using a quantum cascade laser open path system (QCLOPS). The system retrieves the pathaveraged concentration of N2O and CH4 by collecting the backscattered light from a scattering target. The gas concentration measurements have a high temporal resolution (68 ms) and are achieved at sufficient range (up to 40 m, ~ 130 feet) with a detection limit of 2.6 ppm CH4 and 0.4 ppm for N2O. Given these characteristics, this system is promising for mobile/multidirectional remote detection and evaluation of gas leaks. The instrument is monostatic with a tunable QCL emitting at ~ 7.7 μm wavelength range. The backscattered radiation is collected by a Newtonian telescope and focused on an infrared light detector. Puffs of N2O and CH4 are released along the optical path to simulate a gas leak. The measured absorption spectrum is obtained using the thermal intra-pulse frequency chirped DFB QCL and is analyzed to obtain path averaged gas concentrations.

  1. On-line micro-volume introduction system developed for lower density than water extraction solvent and dispersive liquid–liquid microextraction coupled with flame atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Anthemidis, Aristidis N.; Mitani, Constantina; Balkatzopoulou, Paschalia; Tzanavaras, Paraskevas D.

    2012-01-01

    Highlights: ► A dispersive liquid–liquid micro extraction method for lead and copper determination. ► A micro-volume transportation system for extractant solvent lighter than water. ► Analysis of natural water samples. - Abstract: A simple and fast preconcentration/separation dispersive liquid–liquid micro extraction (DLLME) method for metal determination based on the use of extraction solvent with lower density than water has been developed. For this purpose a novel micro-volume introduction system was developed enabling the on-line injection of the organic solvent into flame atomic absorption spectrometry (FAAS). The effectiveness and efficiency of the proposed system were demonstrated for lead and copper preconcentration in environmental water samples using di-isobutyl ketone (DBIK) as extraction solvent. Under the optimum conditions the enhancement factor for lead and copper was 187 and 310 respectively. For a sample volume of 10 mL, the detection limit (3 s) and the relative standard deviation were 1.2 μg L −1 and 3.3% for lead and 0.12 μg L −1 and 2.9% for copper respectively. The developed method was evaluated by analyzing certified reference material and it was applied successfully to the analysis of environmental water samples.

  2. Pair Natural Orbital Restricted Open-Shell Configuration Interaction (PNO-ROCIS) Approach for Calculating X-ray Absorption Spectra of Large Chemical Systems.

    Science.gov (United States)

    Maganas, Dimitrios; DeBeer, Serena; Neese, Frank

    2018-02-08

    In this work, the efficiency of first-principles calculations of X-ray absorption spectra of large chemical systems is drastically improved. The approach is based on the previously developed restricted open-shell configuration interaction singles (ROCIS) method and its parametrized version, based on a density functional theory (DFT) ground-state determinant ROCIS/DFT. The combination of the ROCIS or DFT/ROCIS methods with the well-known machinery of the pair natural orbitals (PNOs) leads to the new PNO-ROCIS and PNO-ROCIS/DFT variants. The PNO-ROCIS method can deliver calculated metal K-, L-, and M-edge XAS spectra orders of magnitude faster than ROCIS while maintaining an accuracy with calculated spectral parameters better than 1% relative to the original ROCIS method (referred to as canonical ROCIS). The method is of a black box character, as it does not require any user adjustments, while it scales quadratically with the system size. It is shown that for large systems, the size of the virtual molecular orbital (MO) space is reduced by more than 90% with respect to the canonical ROCIS method. This allows one to compute the X-ray absorption spectra of a variety of large "real-life" chemical systems featuring hundreds of atoms using a first-principles wave-function-based approach. Examples chosen from the fields of bioinorganic and solid-state chemistry include the Co K-edge XAS spectrum of aquacobalamin [H 2 OCbl] + , the Fe L-edge XAS spectrum of deoxymyoglobin (DMb), the Ti L-edge XAS spectrum of rutile TiO 2 , and the Fe M-edge spectrum of α-Fe 2 O 3 hematite. In the largest calculations presented here, molecules with more than 700 atoms and cluster models with more than 50 metal centers were employed. In all the studied cases, very good to excellent agreement with experiment is obtained. It will be shown that the PNO-ROCIS method provides an unprecedented performance of wave-function-based methods in the field of computational X-ray spectroscopy.

  3. Geometrical interpretation of optical absorption

    Energy Technology Data Exchange (ETDEWEB)

    Monzon, J. J.; Barriuso, A. G.; Sanchez-Soto, L. L. [Departamento de Optica, Facultad de Fisica, Universidad Complutense, E-28040 Madrid (Spain); Montesinos-Amilibia, J. M. [Departamento de Geometria y Topologia, Facultad de Matematicas, Universidad Complutense, E-28040 Madrid (Spain)

    2011-08-15

    We reinterpret the transfer matrix for an absorbing system in very simple geometrical terms. In appropriate variables, the system appears as performing a Lorentz transformation in a (1 + 3)-dimensional space. Using homogeneous coordinates, we map that action on the unit sphere, which is at the realm of the Klein model of hyperbolic geometry. The effects of absorption appear then as a loxodromic transformation, that is, a rhumb line crossing all the meridians at the same angle.

  4. Heavy metal adsorptivity of calcium-alginate-modified diethylenetriamine-silica gel and its application to a flow analytical system using flame atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Mori, Masanobu; Suzuki, Toshinobu; Sugita, Tsuyoshi; Nagai, Daisuke; Hirayama, Kazuo; Onozato, Makoto; Itabashi, Hideyuki

    2014-01-01

    Highlights: • Calcium-alginate-modified dien-silica gel adsorbed multivalent metal ions. • Metal ions adsorbed on CaAD were eluted using low acidic concentrations. • Flow system with CaAD-packed column enriched metal concentrations up to 50-fold. - Abstract: This study aimed to evaluate the heavy metal adsorptivity of calcium-alginate-modified diethylenetriamine-silica gel (CaAD) and incorporate this biosorbent into a flow analytical system for heavy metal ions using flame atomic absorption spectrometry (FAAS). The biosorbent was synthesized by electrostatically coating calcium alginate onto diethylenetriamine (dien)-silica gel. Copper ion adsorption tests by a batch method showed that CaAD exhibited a higher adsorption rate compared with other biosorbents despite its low maximum adsorption capacity. Next, CaAD was packed into a 1 mL microcolumn, which was connected to a flow analytical system equipped with an FAAS instrument. The flow system quantitatively adsorbed heavy metals and enriched their concentrations. This quantitative adsorption was achieved for pH 3–4 solutions containing 1.0 × 10 −6 M of heavy metal ions at a flow rate of 5.0 mL min −1 . Furthermore, the metal ions were successfully desorbed from CaAD at low nitric acid concentrations (0.05–0.15 M) than from the polyaminecarboxylic acid chelating resin (Chelex 100). Therefore, CaAD may be considered as a biosorbent that quickly adsorbs and easily desorbs analyte metal ions. In addition, the flow system enhanced the concentrations of heavy metals such as Cu 2+ , Zn 2+ , and Pb 2+ by 50-fold. This new enrichment system successfully performed the separation and determination of Cu 2+ (5.0 × 10 −8 M) and Zn 2+ (5.7 × 10 −8 M) in a river water sample and Pb 2+ (3.8 × 10 −9 M) in a ground water sample

  5. Human systemic exposure to [¹⁴C]-paraphenylenediamine-containing oxidative hair dyes: Absorption, kinetics, metabolism, excretion and safety assessment.

    Science.gov (United States)

    Nohynek, Gerhard J; Skare, Julie A; Meuling, Wim J A; Wehmeyer, Kenneth R; de Bie, Albertus Th H J; Vaes, Wouter H J; Dufour, Eric K; Fautz, Rolf; Steiling, Winfried; Bramante, Mario; Toutain, Herve

    2015-07-01

    Systemic exposure was measured in humans after hair dyeing with oxidative hair dyes containing 2.0% (A) or 1.0% (B) [(14)C]-p-phenylenediamine (PPD). Hair was dyed, rinsed, dried, clipped and shaved; blood and urine samples were collected for 48 hours after application. [(14)C] was measured in all materials, rinsing water, hair, plasma, urine and skin strips. Plasma and urine were also analysed by HLPC/MS/MS for PPD and its metabolites (B). Total mean recovery of radioactivity was 94.30% (A) or 96.21% (B). Mean plasma Cmax values were 132.6 or 97.4 ng [(14)C]-PPDeq/mL, mean AUC(0-∞) values 1415 or 966 ng [(14)C]-PPDeq/mL*hr in studies A or B, respectively. Urinary excretion of [(14)C] mainly occurred within 24 hrs after hair colouring with a total excretion of 0.72 or 0.88% of applied radioactivity in studies A or B, respectively. Only N,N'-diacetylated-PPD was detected in plasma and the urine. A TK-based human safety assessment estimated margins of safety of 23.3- or 65-fold relative to respective plasma AUC or Cmax values in rats at the NOAEL of a toxicity study. Overall, hair dyes containing PPD are unlikely to pose a health risk since they are used intermittently and systemic exposure is limited to the detoxified metabolite N,N'-diacetyl-PPD. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Interactions between aerosol absorption, thermodynamics, dynamics, and microphysics and their impacts on a multiple-cloud system

    Science.gov (United States)

    Lee, Seoung Soo; Li, Zhanqing; Mok, Jungbin; Ahn, Myoung-Hwan; Kim, Byung-Gon; Choi, Yong-Sang; Jung, Chang-Hoon; Yoo, Hye Lim

    2017-12-01

    This study investigates how the increasing concentration of black carbon aerosols, which act as radiation absorbers as well as agents for the cloud-particle nucleation, affects stability, dynamics and microphysics in a multiple-cloud system using simulations. Simulations show that despite increases in stability due to increasing concentrations of black carbon aerosols, there are increases in the averaged updraft mass fluxes (over the whole simulation domain and period). This is because aerosol-enhanced evaporative cooling intensifies convergence near the surface. This increase in the intensity of convergence induces an increase in the frequency of updrafts with the low range of speeds, leading to the increase in the averaged updraft mass fluxes. The increase in the frequency of updrafts induces that in the number of condensation entities and this leads to more condensation and cloud liquid that acts to be a source of the accretion of cloud liquid by precipitation. Hence, eventually, there is more accretion that offsets suppressed autoconversion, which results in negligible changes in cumulative precipitation as aerosol concentrations increase. The increase in the frequency of updrafts with the low range of speeds alters the cloud-system organization (represented by cloud-depth spatiotemporal distributions and cloud-cell population) by supporting more low-depth clouds. The altered organization in turn alters precipitation spatiotemporal distributions by generating more weak precipitation events. Aerosol-induced reduction in solar radiation that reaches the surface induces more occurrences of small-value surface heat fluxes, which in turn supports the more low-depth clouds and weak precipitation together with the greater occurrence of low-speed updrafts.

  7. ALMA [N ii] 205 μ m Imaging Spectroscopy of the Interacting Galaxy System BRI 1202-0725 at Redshift 4.7

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Nanyao; Xu, C. Kevin; Zhu, Lei [National Astronomical Observatories, Chinese Academy of Sciences (CAS), Beijing 100012 (China); Zhao, Yinghe [Yunnan Observatories, Chinese Academy of Sciences, Kunming 650011 (China); Díaz-Santos, Tanio [Nucleo de Astronomia de la Facultad de Ingenieria, Universidad Diego Portales, Av. Ejercito Libertador 441, Santiago (Chile); Charmandaris, Vassilis [Department of Physics, University of Crete, GR-71003 Heraklion (Greece); Gao, Yu [Purple Mountain Observatory, CAS, Nanjing 210008 (China); Van der Werf, Paul P. [Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden (Netherlands); Privon, George C. [Departamento de Astronomía, Universidad de Concepción, Casilla 160-C, Concepción (Chile); Inami, Hanae [Centre de Recherche Astrophysique de Lyon (CRAL), Observatoire de Lyon, CNRS, UMR5574, F-69230, Saint-Genis-Laval (France); Rigopoulou, Dimitra [Department of Physics, University of Oxford, Keble Road, Oxford OX1 3RH (United Kingdom); Sanders, David B., E-mail: nanyao.lu@gmail.com [University of Hawaii, Institute for Astronomy, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States)

    2017-06-20

    We present the results from Atacama Large Millimeter/submillimeter Array imaging in the [N ii] 205 μ m fine-structure line (hereafter [N ii]) and the underlying continuum of BRI 1202-0725, an interacting galaxy system at z = 4.7, consisting of a quasi-stellar object (QSO), a submillimeter galaxy (SMG), and two Ly α emitters, all within ∼25 kpc of the QSO. We detect the QSO and SMG in both [N ii] and continuum. At the ∼1″ (or 6.6 kpc) resolution, both the QSO and SMG are resolved in [N ii], with the de-convolved major axes of ∼9 and ∼14 kpc, respectively. In contrast, their continuum emissions are much more compact and unresolved even at an enhanced resolution of ∼0.″7. The ratio of the [N ii] flux to the existing CO(7−6) flux is used to constrain the dust temperature ( T {sub dust}) for a more accurate determination of the FIR luminosity L {sub FIR}. Our best estimated T {sub dust} equals 43 (±2) K for both galaxies (assuming an emissivity index β = 1.8). The resulting L {sub CO(7−6)}/ L {sub FIR} ratios are statistically consistent with that of local luminous infrared galaxies, confirming that L {sub CO(7−6)} traces the star formation (SF) rate (SFR) in these galaxies. We estimate that the ongoing SF of the QSO (SMG) has an SFR of 5.1 (6.9) × 10{sup 3} M {sub ⊙} yr{sup −1} (±30%) assuming Chabrier initial mass function, takes place within a diameter (at half maximum) of 1.3 (1.5) kpc, and will consume the existing 5 (5) × 10{sup 11} M {sub ⊙} of molecular gas in 10 (7) × 10{sup 7} years.

  8. Sistema de refrigeración solar por absorción para la comunidad de Kumay en Ecuador; Solar absorption refrigeration system for Kumay community in Ecuador

    Directory of Open Access Journals (Sweden)

    José Antonio Romero Paguay

    2015-04-01

    Full Text Available En el Ecuador existen muchas zonas aisladas, no electrificadas aún, especialmente en la provincia de Pastaza, en este artículo se presenta un sistema de refrigeración por absorción solar  como una alternativa para la climatización de un consultorio médico en la Comunidad de Kumay. Se realiza el cálculo de la estimación de carga térmica en el consultorio médico empleando el software Carrier E20, el cual arroja una necesidad de enfriamiento de 10 kW o 2,84 toneladas de refrigeración (TR. El sistema de refrigeración por absorción con energía solar propuesto está formado por una máquina de absorción, simple efecto de la marca ClimateWell 10, con 10 kW de potencia de enfriamiento que utiliza como absorbente el par cloruro de litio y agua, requiriéndose un área de captación de energía solar de 30 m2 que será entregada con diez colectores de tubos alvacío marca Thermomax, Modelo Solamax 30. In Ecuador there are many non-electrified remote areas, especially in the province of Pastaza, in this article a solar absorption cooling system is presented as an alternative for the air conditioning of a doctor's office (medical clinic in Community Kumay. The calculation of the estimated thermal load on the doctor's office is done using the software Carrier E20, which throws a necessity of cooling of 10 kW or 2,84 tons of refrigeration. The solar cooling system consist in an absorption machine of single effect, ClimateWell 10, with 10 kW of cooling power that uses as absorbent the lithium chloride and water pair, this system  required an area of reception of solar energy of 30 m2 that will be given with 10 vacuum tube collectors Thermomax, Model Solamax 30.

  9. Tunable diode laser absorption spectroscopy-based tomography system for on-line monitoring of two-dimensional distributions of temperature and H2O mole fraction

    International Nuclear Information System (INIS)

    Xu, Lijun; Liu, Chang; Jing, Wenyang; Cao, Zhang; Xue, Xin; Lin, Yuzhen

    2016-01-01

    To monitor two-dimensional (2D) distributions of temperature and H 2 O mole fraction, an on-line tomography system based on tunable diode laser absorption spectroscopy (TDLAS) was developed. To the best of the authors’ knowledge, this is the first report on a multi-view TDLAS-based system for simultaneous tomographic visualization of temperature and H 2 O mole fraction in real time. The system consists of two distributed feedback (DFB) laser diodes, a tomographic sensor, electronic circuits, and a computer. The central frequencies of the two DFB laser diodes are at 7444.36 cm −1 (1343.3 nm) and 7185.6 cm −1 (1391.67 nm), respectively. The tomographic sensor is used to generate fan-beam illumination from five views and to produce 60 ray measurements. The electronic circuits not only provide stable temperature and precise current controlling signals for the laser diodes but also can accurately sample the transmitted laser intensities and extract integrated absorbances in real time. Finally, the integrated absorbances are transferred to the computer, in which the 2D distributions of temperature and H 2 O mole fraction are reconstructed by using a modified Landweber algorithm. In the experiments, the TDLAS-based tomography system was validated by using asymmetric premixed flames with fixed and time-varying equivalent ratios, respectively. The results demonstrate that the system is able to reconstruct the profiles of the 2D distributions of temperature and H 2 O mole fraction of the flame and effectively capture the dynamics of the combustion process, which exhibits good potential for flame monitoring and on-line combustion diagnosis

  10. Solar absorption surface panel

    Science.gov (United States)

    Santala, Teuvo J.

    1978-01-01

    A composite metal of aluminum and nickel is used to form an economical solar absorption surface for a collector plate wherein an intermetallic compound of the aluminum and nickel provides a surface morphology with high absorptance and relatively low infrared emittance along with good durability.

  11. Nutrition and magnesium absorption

    NARCIS (Netherlands)

    Brink, E.J.

    1992-01-01

    The influence of various nutrients present in dairy products and soybean-based products on absorption of magnesium has been investigated. The studies demonstrate that soybean protein versus casein lowers apparent magnesium absorption in rats through its phytate component. However, true

  12. Zeeman atomic absorption spectroscopy

    International Nuclear Information System (INIS)

    Loos-Vollebregt, M.T.C. de.

    1980-01-01

    A new method of background correction in atomic absorption spectroscopy has recently been introduced, based on the Zeeman splitting of spectral lines in a magnetic field. A theoretical analysis of the background correction capability observed in such instruments is presented. A Zeeman atomic absorption spectrometer utilizing a 50 Hz sine wave modulated magnetic field is described. (Auth.)

  13. Corrosion and passivation behavior of various stainless steels in libr solution used in absorption-type refrigeration system

    International Nuclear Information System (INIS)

    Shahid, M.

    2007-01-01

    Various structural materials have been suggested for the refrigeration units to combat high corrosiveness of the absorbent. The corrosion behavior of three grades of austenitic stainless steels, have been investigated in lithium bromide (LiBr) solutions, using electrochemical techniques. Potentiodynamic E- log-i curves, potential-time scans and polarization resistance diagrams obtained by using three-electrode system connected to a computerized Gamry at the rate framework, have been used to analyze their corrosion and passivation behavior in various concentrations of LiBr i.e. commercial LiBr (850 g/J solution containing chromate inhibitor), 400 g/l LiBr and 700 g/J LiBr solutions, at room temperature. Relatively higher corrosion current was observed in SS304 exposed to inhibitor-free electrolyte compared to inhibited commercial solution. Inhibitor proved to be more efficient in case of AISI 304 as it showed significantly higher corrosion rate in un-inhibited solutions. (author)

  14. NLP model of a LiBr–H2O absorption refrigeration system for the minimization of the annual operating cost

    International Nuclear Information System (INIS)

    Rubio-Maya, Carlos; Pacheco-Ibarra, J. Jesús; Belman-Flores, Juan M.; Galván-González, Sergio R.; Mendoza-Covarrubias, Crisanto

    2012-01-01

    In this paper the optimization of a LiBr–H 2 O absorption refrigeration system with the annual operating cost as the objective function to be minimized is presented. The optimization problem is established as a Non-Linear Programming (NLP) model allowing a formulation of the problem in a simple and structured way, and reducing the typical complexity of the thermal systems. The model is composed of three main parts: the thermodynamic model based on the exergy concept including also the proper formulation for the thermodynamic properties of the LiBr–H 2 O mixture, the second is the economic model and the third part composed by inequality constraints. The solution of the model is obtained using the CONOPT solver suitable for NLP problems (code is available on request). The results show the values of the decision variables that minimize the annual cost under the set of assumptions considered in the model and agree well with those reported in other works using different optimization approaches. - Highlights: ► The optimization of an ARS is presented using the annual operating cost as the objective function. ► The problem is established as an NLP model allowing a formulation in a simple and structured way. ► Several formulations for the thermodynamic properties were tested to implement the simpler ones. ► The results obtained agree well with those reported in the work being in comparison.

  15. On-line preconcentration system using a microcolumn packed with Alizarin Red S-modified alumina for zinc determination by flame atomic absorption spectrometry

    Directory of Open Access Journals (Sweden)

    A.M. Haji Shabani

    2009-01-01

    Full Text Available A simple and sensitive on-line flow injection system for determination of zinc with FAAS has been described. The method is based on the separation and preconcentration of zinc on a microcolumn of immobilized Alizarin Red S on alumina. The adsorbed analyte is then eluted with 250 µL of nitric acid (1 mol L-1 and is transported to flame atomic absorption spectrometer for quantification. The effect of pH, sample and eluent flow rates and presence of various cations and anions on the retention of zinc was investigated. The sorption of zinc was quantitative in the pH range of 5.5-8.5. For a sample volume of 25 mL an enrichment factor of 144 and a detection limit (3S of 0.2 µg L-1 was obtained. The precision (RSD, n=7 was 3.0% at the 20 µg L-1 level. The developed system was successfully applied to the determination of zinc in water samples, hair, urine and saliva.

  16. An overview on the research of Sr2IrO4-based system probed by X-ray absorption spectroscopy

    Science.gov (United States)

    Cheng, Jie; Zhu, Chaomin; Ma, Jingyuan; Wang, Yu; Liu, Shengli

    2018-03-01

    Investigations of materials with 5d transition metal ions have opened up new paradigms in condensed-matter physics because of their large spin-orbit coupling (SOC) interactions. The typical compound is Sr2IrO4, which attracted much attention due to its similarities to the parent compound of high-Tc cuprate superconductor La2CuO4. Theoretical calculations predicted that the unconventional superconductivity can occur in carrier doped-Sr2IrO4 system. Until now, hundreds of experimental methods were devoted to investigate the carrier doping effect on Sr2IrO4. Synchrotron radiation-based X-ray absorption spectroscopy (XAS) made great contributions to the local lattice and electronic structure, and also the intimate relationship between the local structure and physical properties induced by carrier doping. The aim of this review is a short introduction to the progress of research on Sr2IrO4-based system probed by the unique technique — XAS, including the strength of the SOC, valence changes upon doping and even local lattice structure with atomic level for this Sr2IrO4-based family.

  17. Combined Brillouin light scattering and microwave absorption study of magnon-photon coupling in a split-ring resonator/YIG film system

    Energy Technology Data Exchange (ETDEWEB)

    Klingler, S., E-mail: stefan.klingler@wmi.badw.de; Maier-Flaig, H.; Weiler, M. [Walther-Meißner-Institut, Bayerische Akademie der Wissenschaften, Walther-Meißner-Straße 8, 85748 Garching (Germany); Physik-Department, Technische Universität München, 85748 Garching (Germany); Gross, R.; Huebl, H.; Goennenwein, S. T. B. [Walther-Meißner-Institut, Bayerische Akademie der Wissenschaften, Walther-Meißner-Straße 8, 85748 Garching (Germany); Physik-Department, Technische Universität München, 85748 Garching (Germany); Nanosystems Initiative Munich (NIM), 80799 Munich (Germany); Hu, C.-M. [Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba R3T2N2 (Canada)

    2016-08-15

    Microfocused Brillouin light scattering (BLS) and microwave absorption (MA) are used to study magnon-photon coupling in a system consisting of a split-ring microwave resonator and an yttrium iron garnet (YIG) film. The split-ring resonator is defined by optical lithography and loaded with a 1 μm-thick YIG film grown by liquid phase epitaxy. BLS and MA spectra of the hybrid system are simultaneously recorded as a function of the applied magnetic field magnitude and microwave excitation frequency. Strong coupling of the magnon and microwave resonator modes is found with a coupling strength of g{sub eff} /2π = 63 MHz. The combined BLS and MA data allow us to study the continuous transition of the hybridized modes from a purely magnonic to a purely photonic mode by varying the applied magnetic field and microwave frequency. Furthermore, the BLS data represent an up-conversion of the microwave frequency coupling to optical frequencies.

  18. Power and polarization dependences of ultra-narrow electromagnetically induced absorption (EIA) spectra of 85 Rb atoms in degenerate two-level system

    Science.gov (United States)

    Qureshi, Muhammad Mohsin; Rehman, Hafeez Ur; Noh, Heung-Ryoul; Kim, Jin-Tae

    2016-05-01

    We have investigated ultra-narrow EIA spectral features with respect to variations of polarizations and powers of pump laser beam in a degenerate two-level system of the transition of 85 Rb D2 transition line. Polarizations of the probe laser beam in two separate experiments were fixed at right circular and horizontal linear polarizations, respectively while the polarizations of the pump lasers were varied from initial polarizations same as the probe laser beams to orthogonal to probe polarizations. One homemade laser combined with AOMs was used to the pump and probe laser beams instead of two different lasers to overcome broad linewidths of the homemade lasers. Theoretically, probe absorption coefficients have been calculated from optical Bloch equations of the degenerate two level system prepared by a pump laser beam. In the case of the circular polarization, EIA signal was obtained as expected theoretically although both pump and probe beams have same polarization. The EIA signal become smaller as power increases and polarizations of the pump and probe beams were same. When the polarization of the pump beam was linear polarization, maximum EIA signal was obtained theoretically and experimentally. Experimental EIA spectral shapes with respect to variations of the pump beam polarization shows similar trends as the theoretical results.

  19. Automatic flow-batch system for cold vapor atomic absorption spectroscopy determination of mercury in honey from Argentina using online sample treatment.

    Science.gov (United States)

    Domínguez, Marina A; Grünhut, Marcos; Pistonesi, Marcelo F; Di Nezio, María S; Centurión, María E

    2012-05-16

    An automatic flow-batch system that includes two borosilicate glass chambers to perform sample digestion and cold vapor atomic absorption spectroscopy determination of mercury in honey samples was designed. The sample digestion was performed by using a low-cost halogen lamp to obtain the optimum temperature. Optimization of the digestion procedure was done using a Box-Behnken experimental design. A linear response was observed from 2.30 to 11.20 μg Hg L(-1). The relative standard deviation was 3.20% (n = 11, 6.81 μg Hg L(-1)), the sample throughput was 4 sample h(-1), and the detection limit was 0.68 μg Hg L(-1). The obtained results with the flow-batch method are in good agreement with those obtained with the reference method. The flow-batch system is simple, allows the use of both chambers simultaneously, is seen as a promising methodology for achieving green chemistry goals, and is a good proposal to improving the quality control of honey.

  20. An automated flow injection system for metal determination by flame atomic absorption spectrometry involving on-line fabric disk sorptive extraction technique.

    Science.gov (United States)

    Anthemidis, A; Kazantzi, V; Samanidou, V; Kabir, A; Furton, K G

    2016-08-15

    A novel flow injection-fabric disk sorptive extraction (FI-FDSE) system was developed for automated determination of trace metals. The platform was based on a minicolumn packed with sol-gel coated fabric media in the form of disks, incorporated into an on-line solid-phase extraction system, coupled with flame atomic absorption spectrometry (FAAS). This configuration provides minor backpressure, resulting in high loading flow rates and shorter analytical cycles. The potentials of this technique were demonstrated for trace lead and cadmium determination in environmental water samples. The applicability of different sol-gel coated FPSE media was investigated. The on-line formed complex of metal with ammonium pyrrolidine dithiocarbamate (APDC) was retained onto the fabric surface and methyl isobutyl ketone (MIBK) was used to elute the analytes prior to atomization. For 90s preconcentration time, enrichment factors of 140 and 38 and detection limits (3σ) of 1.8 and 0.4μgL(-1) were achieved for lead and cadmium determination, respectively, with a sampling frequency of 30h(-1). The accuracy of the proposed method was estimated by analyzing standard reference materials and spiked water samples. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Development and validation of LC-MS/MS assay for the determination of Butoconazole in human plasma: Evaluation of systemic absorption following topical application in healthy volunteers

    Directory of Open Access Journals (Sweden)

    Eman G. Nouman

    2017-12-01

    Full Text Available Butoconazole is an imidazole antifungal that is more effective than miconazole and clotrimazole for treatment of vaginal candidiasis. A highly sensitive tandem mass spectrometric assay was developed and validated to evaluate systemic absorption of Butoconazole following intravaginal administration. Chromatographic separation was achieved using Waters Xterra C18 column (3 µm, 3.0 × 50.0 mm. Liquid-liquid extraction using tert-butyl methyl ether was used for preparation of plasma samples. The mobile phase was solvent A: 0.1% formic acid in water and solvent B: acetonitrile: methanol (30:70, v/v, using gradient elution mode at 0.5 mL/min. Detection at positive electrospray ionization in the MRM mode was then employed. Analysis was carried out within 5.5 min over a linear concentration range of 0.10–30.00 ng/mL. Validation was carried out according to US FDA guidelines for bioanalytical method validation. Matrix effect, recovery efficiency and process efficiency have been investigated for the analyte and internal standard in neat solvent, post-extraction matrix and plasma. The mean percentage recoveries were higher than 80%, the accuracy was 93.51–106.85% and the RSD was below 10% throughout the studied concentration range. Results indicated sufficient stability of the target analyte in plasma at the employed experimental conditions. Results of incurred sample re-analysis and incurred sample stability revealed less than 5% variability. The applicability of the assay for monitoring of the systemic absorption of Butoconazole following intra vaginal application to healthy volunteers was demonstrated. Results confirmed that Butoconazole was detected shortly after intra vaginal administration with Cmax and tmax of 30 ng/mL and 6 h, respectively. Keywords: Butoconazole, LC-MS/MS, Matrix effect, Process efficiency, Recovery efficiency

  2. Analysis of in situ electric field and specific absorption rate in human models for wireless power transfer system with induction coupling

    International Nuclear Information System (INIS)

    Sunohara, Tetsu; Hirata, Akimasa; Laakso, Ilkka; Onishi, Teruo

    2014-01-01

    This study investigates the specific absorption rate (SAR) and the in situ electric field in anatomically based human models for the magnetic field from an inductive wireless power transfer system developed on the basis of the specifications of the wireless power consortium. The transfer system consists of two induction coils covered by magnetic sheets. Both the waiting and charging conditions are considered. The transfer frequency considered in this study is 140 kHz, which is within the range where the magneto-quasi-static approximation is valid. The SAR and in situ electric field in the chest and arm of the models are calculated by numerically solving the scalar potential finite difference equation. The electromagnetic modelling of the coils in the wireless power transfer system is verified by comparing the computed and measured magnetic field distributions. The results indicate that the peak value of the SAR averaged over a 10 g of tissue and that of the in situ electric field are 72 nW kg −1  and 91 mV m −1  for a transmitted power of 1 W, Consequently, the maximum allowable transmitted powers satisfying the exposure limits of the SAR (2 W kg −1 ) and the in situ electric field (18.9 V m −1 ) are found to be 28 MW and 43 kW. The computational results show that the in situ electric field in the chest is the most restrictive factor when compliance with the wireless power transfer system is evaluated according to international guidelines. (paper)

  3. Analysis of in situ electric field and specific absorption rate in human models for wireless power transfer system with induction coupling.

    Science.gov (United States)

    Sunohara, Tetsu; Hirata, Akimasa; Laakso, Ilkka; Onishi, Teruo

    2014-07-21

    This study investigates the specific absorption rate (SAR) and the in situ electric field in anatomically based human models for the magnetic field from an inductive wireless power transfer system developed on the basis of the specifications of the wireless power consortium. The transfer system consists of two induction coils covered by magnetic sheets. Both the waiting and charging conditions are considered. The transfer frequency considered in this study is 140 kHz, which is within the range where the magneto-quasi-static approximation is valid. The SAR and in situ electric field in the chest and arm of the models are calculated by numerically solving the scalar potential finite difference equation. The electromagnetic modelling of the coils in the wireless power transfer system is verified by comparing the computed and measured magnetic field distributions. The results indicate that the peak value of the SAR averaged over a 10 g of tissue and that of the in situ electric field are 72 nW kg(-1) and 91 mV m(-1) for a transmitted power of 1 W, Consequently, the maximum allowable transmitted powers satisfying the exposure limits of the SAR (2 W kg(-1)) and the in situ electric field (18.9 V m(-1)) are found to be 28 MW and 43 kW. The computational results show that the in situ electric field in the chest is the most restrictive factor when compliance with the wireless power transfer system is evaluated according to international guidelines.

  4. The Elixir System: Data Characterization and Calibration at the Canada-France-Hawaii Telescope

    Science.gov (United States)

    Magnier, E. A.; Cuillandre, J.-C.

    2004-05-01

    The Elixir System at the Canada-France-Hawaii Telescope performs data characterization and calibration for all data from the wide-field mosaic imagers CFH12K and MegaPrime. The project has several related goals, including monitoring data quality, providing high-quality master detrend images, determining the photometric and astrometric calibrations, and automatic preprocessing of images for queued service observing (QSO). The Elixir system has been used for all data obtained with CFH12K since the QSO project began in 2001 January. In addition, it has been used to process archival data from the CFH12K and all MegaPrime observations beginning in 2002 December. The Elixir system has been extremely successful in providing well-characterized data to the end observers, who may otherwise be overwhelmed by data-processing concerns.

  5. Solar cells based on particulate structure of active layer: Investigation of light absorption by an ordered system of spherical submicron silicon particles

    Science.gov (United States)

    Miskevich, Alexander A.; Loiko, Valery A.

    2015-12-01

    Enhancement of the performance of photovoltaic cells through increasing light absorption due to optimization of an active layer is considered. The optimization consists in creation of particulate structure of active layer. The ordered monolayers and multilayers of submicron crystalline silicon (c-Si) spherical particles are examined. The quasicrystalline approximation (QCA) and the transfer matrix method (TMM) are used to calculate light absorption in the wavelength range from 0.28 μm to 1.12 μm. The integrated over the terrestial solar spectral irradiance "Global tilt" ASTM G173-03 absorption coefficient is calculated. In the wavelength range of small absorption index of c-Si (0.8-1.12 μm) the integral absorption coefficient of monolayer can be more than 20 times higher than the one of the plane-parallel plate of the equivalent volume of material. In the overall considered range (0.28-1.12 μm) the enhancement factor up to ~1.45 for individual monolayer is observed. Maximum value of the spectral absorption coefficient approaches unity for multilayers consisting of large amount of sparse monolayers of small particles. Multilayers with variable concentration and size of particles in the monolayer sequences are considered. Absorption increasing by such gradient multilayers as compared to the non-gradient ones is illustrated. The considered structures are promising for creation of high efficiency thin-film solar cells.

  6. Evolution of absorption machines; Evolution des machines a absorption

    Energy Technology Data Exchange (ETDEWEB)

    Soide, I; Klemsdal, E [Gaz de France (GDF), 75 - Paris (France); Le Goff, P; Hornut, J M [LSGC-ENSIC, 54 - Nancy (France)

    1998-12-31

    Most of todays absorption air-conditioning machineries use the lithium bromide-water pair. The most performing can operate at a 150-160 deg. C, the temperature being limited by the corrosion resistance of metals with respect to LiBr solutions. Also, there is a revival of interest for water-ammonia systems. These systems require the use of a rectification column which reduces the coefficient of performance. Higher thermal performances are reached with hydrocarbon pairs and ternary mixtures (water-methanol-LiBr etc..). This paper presents different schemes of refrigerating heat pumps based on these different systems. (J.S.)

  7. Evolution of absorption machines; Evolution des machines a absorption

    Energy Technology Data Exchange (ETDEWEB)

    Soide, I.; Klemsdal, E. [Gaz de France (GDF), 75 - Paris (France); Le Goff, P.; Hornut, J.M. [LSGC-ENSIC, 54 - Nancy (France)

    1997-12-31

    Most of todays absorption air-conditioning machineries use the lithium bromide-water pair. The most performing can operate at a 150-160 deg. C, the temperature being limited by the corrosion resistance of metals with respect to LiBr solutions. Also, there is a revival of interest for water-ammonia systems. These systems require the use of a rectification column which reduces the coefficient of performance. Higher thermal performances are reached with hydrocarbon pairs and ternary mixtures (water-methanol-LiBr etc..). This paper presents different schemes of refrigerating heat pumps based on these different systems. (J.S.)

  8. Quasar Absorption Studies

    Science.gov (United States)

    Mushotzky, Richard (Technical Monitor); Elvis, Martin

    2004-01-01

    The aim of the proposal is to investigate the absorption properties of a sample of inter-mediate redshift quasars. The main goals of the project are: Measure the redshift and the column density of the X-ray absorbers; test the correlation between absorption and redshift suggested by ROSAT and ASCA data; constrain the absorber ionization status and metallicity; constrain the absorber dust content and composition through the comparison between the amount of X-ray absorption and optical dust extinction. Unanticipated low energy cut-offs where discovered in ROSAT spectra of quasars and confirmed by ASCA, BeppoSAX and Chandra. In most cases it was not possible to constrain adequately the redshift of the absorber from the X-ray data alone. Two possibilities remain open: a) absorption at the quasar redshift; and b) intervening absorption. The evidences in favour of intrinsic absorption are all indirect. Sensitive XMM observations can discriminate between these different scenarios. If the absorption is at the quasar redshift we can study whether the quasar environment evolves with the Cosmic time.

  9. Combination therapy with solifenacin and tamsulosin oral controlled absorption system in a single tablet for lower urinary tract symptoms in men: efficacy and safety results from the randomised controlled NEPTUNE trial

    NARCIS (Netherlands)

    van Kerrebroeck, Philip; Chapple, Christopher; Drogendijk, Ted; Klaver, Monique; Sokol, Roman; Speakman, Mark; Traudtner, Klaudia; Drake, Marcus J.; Kiss, G.; Marberger, M.; Strotski, A. V.; Varaksa, A. N.; Vashchula, V.; Dewilde, T.; Braeckman, J.; Roumeguere, T.; Wyndaele, J. J.; Ameye, F.; Everaert, K.; van Cleynenbruegel, B.; de Leval, J.; Vanderkerken, J.; Ackaert, K.; Hiblbauer, J.; Zhanel, P.; Klecka, J.; Lukes, M.; Novak, J.; Lisec, M.; Vrtal, R.; Ondra, D.; Liehne, J.; Tuma, J.; Azzouzi, A.-R.; Wellerand, H.; Jung, J.-L.; Mourey, E.; Colombel, M.; Claude, R.; Ibrahim, H.; Desgrandchamps, F.; Haab, F.; Zerbib, M.; Ruffion, A.; Vincendeau, S.; Haillot, O.; Hentschel, M.; Gerhardt, U.; Hechelmann, W.; de la Rosette, J.

    2013-01-01

    Storage symptoms are particularly bothersome in men with lower urinary tract symptoms (LUTS) but may not be adequately treated by α-blocker monotherapy. To assess the efficacy and safety of a fixed-dose combination (FDC) of solifenacin and an oral controlled absorption system (OCAS) formulation of

  10. Determination of trace metal ions via on-line separation and preconcentration by means of chelating Sepharose beads in a sequential injection lab-on-valve (SI-LOV) system coupled to electrothermal atomic absorption spectrometric detection

    DEFF Research Database (Denmark)

    Long, Xiangbao; Hansen, Elo Harald; Miró, Manuel

    2005-01-01

    The analytical performance of an on-line sequential injection lab-on-valve (SI-LOV) system using chelating Sepharose beads as sorbent material for the determination of ultra trace levels of Cd(II), Pb(II) and Ni(II) by electrothermal atomic absorption spectrometry (ETAAS) is described and discussed...

  11. Uranium absorption study pile

    International Nuclear Information System (INIS)

    Raievski, V.; Sautiez, B.

    1959-01-01

    The report describes a pile designed to measure the absorption of fuel slugs. The pile is of graphite and comprises a central section composed of uranium rods in a regular lattice. RaBe sources and BF 3 counters are situated on either side of the center. A given uranium charge is compared with a specimen charge of about 560 kg, and the difference in absorption between the two noted. The sensitivity of the equipment will detect absorption variations of about a few ppm boron (10 -6 boron per gr. of uranium) or better. (author) [fr

  12. Total photon absorption

    International Nuclear Information System (INIS)

    Carlos, P.

    1985-06-01

    The present discussion is limited to a presentation of the most recent total photonuclear absorption experiments performed with real photons at intermediate energy, and more precisely in the region of nucleon resonances. The main sources of real photons are briefly reviewed and the experimental procedures used for total photonuclear absorption cross section measurements. The main results obtained below 140 MeV photon energy as well as above 2 GeV are recalled. The experimental study of total photonuclear absorption in the nuclear resonance region (140 MeV< E<2 GeV) is still at its beginning and some results are presented

  13. A biosorption system for metal ions on Penicillium italicum - loaded on Sepabeads SP 70 prior to flame atomic absorption spectrometric determinations

    International Nuclear Information System (INIS)

    Mendil, Durali; Tuzen, Mustafa; Soylak, Mustafa

    2008-01-01

    A solid phase extraction (SPE) preconcentration system, coupled to a flame atomic absorption spectrometer (FAAS), was developed for the determination of copper(II), cadmium(II), lead(II), manganese(II), iron(III), nickel(II) and cobalt(II) ions at the μg L -1 levels on Penicillium italicum - loaded on Sepabeads SP 70. The analytes were adsorbed on biosorbent at the pH range of 8.5-9.5. The adsorbed metals were eluted with 1 mol L -1 HCl. The influences of the various analytical parameters including pH of the aqueous solutions, sample volume, flow rates were investigated for the retentions of the analyte ions. The recovery values are ranged from 95-102%. The influences of alkaline, earth alkaline and some transition metal ions were also discussed. Under the optimized conditions, the detection limits (3 s, n = 21) for analytes were in the range of 0.41 μg L -1 (cadmium) and 1.60 μg L -1 (iron). The standard reference materials (IAEA 336 Lichen, NIST SRM 1573a Tomato leaves) were analyzed to verify the proposed method. The method was successfully applied for the determinations of analytes in natural water, cultivated mushroom, lichen (Bryum capilare Hedw), moss (Homalothecium sericeum) and refined table salt samples

  14. On-line preconcentration system using a minicolumn of polyurethane foam loaded with Me-BTABr for zinc determination by Flame Atomic Absorption Spectrometry

    International Nuclear Information System (INIS)

    Azevedo Lemos, Valfredo; Nei Lopes dos Santos, Walter; Silva Santos, Juracir; Bezerra de Carvalho, Marcilio

    2003-01-01

    In the present paper, an on-line system for preconcentration and determination of zinc by Flame Atomic Absorption Spectrometry (FAAS) is proposed. It is based in the sorption of zinc(II) ions on a minicolumn packed with polyurethane foam loaded with 2-[2'-(6-methyl-benzothiazolylazo)]-4-bromophenol (Me-BTABr) reagent. Chemical and flow variables as pH effect, sample flow rate and eluent concentration were optimized using univariate methodology. The results demonstrated that zinc can determinate using the sample pH in the range of 6.5-9.2, sample flow rate of 6.0 ml min -1 , and the elution step using 0.10 mol l -1 hydrochloric acid solution at flow rate of 5.5 ml min -1 . In these conditions, an enrichment factor of 23 and a sampling rate of 48 samples per hour were achieved. The detection limit (DL, 3σ) as IUPAC recommendation was 0.37 μg l -1 and the precision (assessed as the relative standard deviation, R.S.D.) reached values of 5.9-1.8% in zinc solutions of 1.0-10.0 μg l -1 concentration, respectively. The method was successfully applied to the determination of trace amounts of zinc in natural water samples from Salvador (Brazil)

  15. Free convective heat transfer with hall effects, heat absorption and chemical reaction over an accelerated moving plate in a rotating system

    Energy Technology Data Exchange (ETDEWEB)

    Hussain, S.M., E-mail: hussain.modassir@yahoo.com [Department of Mathematics, OP Jindal University, Raigarh 496109 (India); Jain, J., E-mail: jj.28481@gmail.com [Department of Mathematics, OP Jindal University, Raigarh 496109 (India); Seth, G.S., E-mail: gsseth_ism@yahoo.com [Department of Applied Mathematics, Indian School of Mines, Dhanbad 826004 (India); Rashidi, M.M., E-mail: mm_rashidi@yahoo.com [Shanghai Key Lab of Vehicle Aerodynamics and Vehicle Thermal Management System, Tongji University, Shanghai 201804 (China)

    2017-01-15

    The unsteady MHD free convective heat and mass transfer flow of an electrically conducting, viscous and incompressible fluid over an accelerated moving vertical plate in the presence of heat absorption and chemical reaction with ramped temperature and ramped surface concentration through a porous medium in a rotating system is studied, taking Hall effects into account. The governing equations are solved analytically with the help of Laplace transform technique. The unified closed-form expressions are obtained for fluid velocity, fluid temperature, species concentration, skin friction, Nusselt number and Sherwood numbers. The effects of various parameters on fluid velocity, fluid temperature and species concentration are discussed by graphs whereas numerical values of skin friction, Nusselt and Sherwood numbers are presented in tabular form for different values of pertinent flow parameters. The numerical results are also compared with free convective flow near ramped temperature plate with ramped surface concentration with the corresponding flow near isothermal plate with uniform surface concentration. - Highlights: • Magnetic field, Hall current, rotation and chemical reaction play vital role on flow field. • Hall current tends to accelerate secondary fluid velocity in the boundary layer region. • Rotation tends to retard primary fluid velocity throughout the boundary layer region. • Rotation and chemical reaction tend to enhance primary skin friction. • Solutal buoyancy force and permeability of medium reduce primary skin friction.

  16. A biosorption system for metal ions on Penicillium italicum - loaded on Sepabeads SP 70 prior to flame atomic absorption spectrometric determinations

    Energy Technology Data Exchange (ETDEWEB)

    Mendil, Durali; Tuzen, Mustafa [Gaziosmanpasa University, Faculty of Science and Arts, Chemistry Department, 60250 Tokat (Turkey); Soylak, Mustafa [Erciyes University, Faculty of Science and Arts, Chemistry Department, 38039 Kayseri (Turkey)], E-mail: msoylak@gmail.com

    2008-04-15

    A solid phase extraction (SPE) preconcentration system, coupled to a flame atomic absorption spectrometer (FAAS), was developed for the determination of copper(II), cadmium(II), lead(II), manganese(II), iron(III), nickel(II) and cobalt(II) ions at the {mu}g L{sup -1} levels on Penicillium italicum - loaded on Sepabeads SP 70. The analytes were adsorbed on biosorbent at the pH range of 8.5-9.5. The adsorbed metals were eluted with 1 mol L{sup -1} HCl. The influences of the various analytical parameters including pH of the aqueous solutions, sample volume, flow rates were investigated for the retentions of the analyte ions. The recovery values are ranged from 95-102%. The influences of alkaline, earth alkaline and some transition metal ions were also discussed. Under the optimized conditions, the detection limits (3 s, n = 21) for analytes were in the range of 0.41 {mu}g L{sup -1} (cadmium) and 1.60 {mu}g L{sup -1} (iron). The standard reference materials (IAEA 336 Lichen, NIST SRM 1573a Tomato leaves) were analyzed to verify the proposed method. The method was successfully applied for the determinations of analytes in natural water, cultivated mushroom, lichen (Bryum capilare Hedw), moss (Homalothecium sericeum) and refined table salt samples.

  17. Determination of lead in whole blood: Comparison of the LeadCare blood lead testing system with zeeman longitudinal electrothermal atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Pineau, A.; Viallefont, A.; Fauconneau, B.; Rafael, M.; Guillard, O.

    2002-01-01

    This study compares the efficiency of blood lead level analysis by graphite furnace atomic absorption spectrometry (GFAAS) and the portable LeadCare Blood lead testing system (LCS). Recoveries of two added lead concentrations of 22 and 42 μg/dL ranged from 102.4 to 105.5% for LCS and from 96.3 to 97.2% for GFAAS. Measurement of a certified sample (Certified Danish Whole Blood) at a blood lead concentration of 26.2 μg/dL gave within- and between-run coefficients of variation which were both approximately 8% by LCS and 2% by GFAAS. Comparison of the tested method (LCS) versus GFAAS from analysis of 76 samples of blood lead collected from workers in different industrial sectors showed imperfect overall correlation (r = 0.95). The LCS is quite suitable for screening purposes, but requires the use of non-frozen blood collected less than 24 h before. Conservative threshold values should be applied when using the LCS for initial screening in the field. (orig.)

  18. Energy analysis of a diffusion absorption cooling system using lithium nitrate, sodium thiocyanate and water as absorbent substances and ammonia as the refrigerant

    International Nuclear Information System (INIS)

    Acuña, A.; Velázquez, N.; Cerezo, J.

    2013-01-01

    A diffusion absorption cooling system is analyzed to determine the appropriate fluid for the unit, based on the coefficient of performance (COP) and operating conditions, by comparing lithium nitrate (LiNO 3 ), sodium thiocyanate (NaSCN) and water (H 2 O) as absorbent substances and by using ammonia (NH 3 ) as the refrigerant. The presence of crystallization in the system is analyzed as a function of the generator and absorber temperatures. Additionally, the effects on the efficiency of the system from adding the inert gas helium (He) or hydrogen (H 2 ) are studied. A mathematical model is developed and compared to experimental studies reported in the literature. At an evaporator temperature of −15 °C, a generator temperature of 120 °C and absorber and condenser temperatures of 40 °C, the results show that the best performance is achieved by the NH 3 –LiNO 3 –He mixture, with a COP of 0.48. This mixture performs 27–46% more efficient than the NH 3 –NaSCN mixture. The NH 3 –H 2 O mixture is 52–69% less efficient than the NH 3 –LiNO 3 mixture. However, when the evaporator runs at 7.5 °C, the NH 3 –H 2 O–He mixture achieves a more efficient COP than does the NH 3 –LiNO 3 –He mixture, and the NH 3 –NaSCN–He and NH 3 –LiNO 3 –He mixtures achieve the same COP when the evaporator is at 10 °C. At temperatures below 7.5 °C, the NH 3 –NaSCN–He mixture achieves a higher COP than does the NH 3 –H 2 O–He mixture. The NH 3 –LiNO 3 mixture shows crystallization at higher temperatures in the generator than does the NH 3 –NaSCN mixture. Moreover, at the same evaporator temperature, the NH 3 –LiNO 3 mixture works at activation temperatures lower than does the NH 3 –NaSCN mixture. -- Highlights: ► We studied a diffusion absorption cooling system with different working mixtures. ► The NH 3 –LiNO 3 mixture showed more efficiency than NH 3 –H 2 O mixture and NH 3 –NaSCN mixture. ► The generator and absorber temperature

  19. Structural study of glasses in the binary system NaPO{sub 3}-MoO{sub 3} by X-ray absorption spectroscopy at the Mo K and L{sub 3} edges

    Energy Technology Data Exchange (ETDEWEB)

    Poirier, Gael, E-mail: gael@unifal-mg.edu.br [Department of Science and Technology, UNIFAL-MG, Rua Corumba 72, CEP 37701-100, Pocos de Caldas, MG (Brazil); Cassanjes, Fabia C. [Department of Science and Technology, UNIFAL-MG, Rua Corumba 72, CEP 37701-100, Pocos de Caldas, MG (Brazil)

    2010-04-15

    Glasses were prepared in the binary system (100 - x)NaPO{sub 3}-xMoO{sub 3} with x varying from 0 to 50 mol%. An increase in the MoO{sub 3} concentration promotes a strong absorption in the visible and near infrared attributed to Mo reduction during glass synthesis. X-ray absorption measurements were performed at the Mo K and L{sub 3} edges to investigate both the coordination number and oxidation state of Mo in these glasses. The evolution of the pre-peak observed at the K edge suggests that Mo atoms are six-fold coordinated in these glasses. This hypothesis was confirmed by data obtained at the Mo-L{sub 3}-absorption edge. Since the final electronic states at the L{sub 3}-absorption edge are mostly orbitals of d-character which are splitted by the ligand field, the amplitude of the d-orbital splitting could be estimated and the related coordination number of Mo obtained. Finally, the oxidation state of Mo could be related with a change of the white line intensity at the Mo-L{sub 3} edge. These results confirm that the optical absorption in the visible is due to Mo reduction and that transparent samples prepared by slow cooling contain less reduced Mo species.

  20. Galactic absorption line coronae

    International Nuclear Information System (INIS)

    Bregman, J.N.

    1981-01-01

    We have investigated whether gaseous coronae around galaxies rise to the absorption systems seen in quasar spectra. In our model, gas originally located in the disk is heated to the million degree range and rises to surround the galaxy; the gas remains bound to the galaxy. Optically thin radiative cooling drives a thermal instability in the hot gas which causes cool clouds (T 4 K) to condense out of the corona. These clouds, which follow ballistic trajectories back to the disk, are the absorption sites. A two-dimensional hydrodynamic code with radiative cooling was used to study the dynamics and thermodynamics of the corona as well as the position rate at which clouds form. Coupled to the code is a galaxy with two mass components, a disk (approx.10 11 M/sub sun/) and a dark halo (approx.10 12 M/sub sun/). In a model where the temperature at the base of the corona (in the disk) is 3 x 10 6 K, absorbing gas of column density NL> or approx. =10 18 cm 2 extends radially to 100 kpc (face-on orientation) and vertically to 60 Kpc (edge-on orientation). The total mass of gas required here (coronal plus cloud gas) is 1.4 x 10 10 M/sub sun/, while the minimum supernova heating rate is one supernova per 27 years. In two other models (base coronal temperatures of 0.50 x 10 6 K and 1 x 10 6 K), coronal gas rises from an extended gaseous disk (in the previous model, the gas comes from a typical gaseous disk approximately 15 kpc in extent). Here, column densities of 10 19 cm -2 out to a radius of 70 kpc (face-on orientation) are achieved with a total gas mass of 1.7 x 10 9 M/sub direct-product/ and 2.0 x 10 9 M/sub sun/ and minimum heating rates of approximately one supernova per 170 years and one supernova per 60 years

  1. Carbon Dioxide Absorption Heat Pump

    Science.gov (United States)

    Jones, Jack A. (Inventor)

    2002-01-01

    A carbon dioxide absorption heat pump cycle is disclosed using a high pressure stage and a super-critical cooling stage to provide a non-toxic system. Using carbon dioxide gas as the working fluid in the system, the present invention desorbs the CO2 from an absorbent and cools the gas in the super-critical state to deliver heat thereby. The cooled CO2 gas is then expanded thereby providing cooling and is returned to an absorber for further cycling. Strategic use of heat exchangers can increase the efficiency and performance of the system.

  2. Zeeman atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Hadeishi, T.; McLaughlin, R.

    1978-08-01

    The design and development of a Zeeman atomic absorption spectrometer for trace element analysis are described. An instruction manual is included which details the operation, adjustment, and maintenance. Specifications and circuit diagrams are given

  3. Revisiting Absorptive Capacity

    DEFF Research Database (Denmark)

    de Araújo, Ana Luiza Lara; Ulhøi, John Parm; Lettl, Christopher

    Absorptive capacity has mostly been perceived as a 'passive' outcome of R&D investments. Recently, however, a growing interest into its 'proactive' potentials has emerged. This paper taps into this development and proposes a dynamic model for conceptualizing the determinants of the complementary...... learning processes of absorptive capacity, which comprise combinative and adaptive capabilities. Drawing on survey data (n=169), the study concludes that combinative capabilities primarily enhance transformative and exploratory learning processes, while adaptive capabilities strengthen all three learning...

  4. Preconcentration and speciation of chromium in a sequential injection system incorporating dual mini-columns coupled with electrothermal atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Zou Aimei; Tang Xiaoyan; Chen Mingli [Research Center for Analytical Sciences, Northeastern University, Box 332, Shenyang 110004 (China); Wang Jianhua [Research Center for Analytical Sciences, Northeastern University, Box 332, Shenyang 110004 (China)], E-mail: jianhuajrz@mail.neu.edu.cn

    2008-05-15

    A procedure for chromium preconcentration and speciation with a dual mini-column sequential injection system coupled with electrothermal atomic absorption spectrometry (ETAAS) was developed. At pH 6, the sample solution was firstly aspirated to flow through a Chlorella vulgaris cell mini-column on which the Cr(III) was retained. The effluent was afterwards directed to flow through a 717 anion exchange resin mini-column accompanied by the retention of Cr(VI). Thereafter, Cr(III) and Cr(VI) were eluted by 0.04 mol L{sup -1} and 1.0 mol L{sup -1} nitric acid, respectively, and the eluates were quantified with ETAAS. Chemical and flow variables governing the performance of the system were investigated. By using a sampling volume of 600 {mu}L, sorption efficiencies of 99.7% for Cr(III) and 99% for Cr(VI) were achieved along with enrichment factors of 10.5 for Cr(III) and 11.6 for Cr(VI), within linear ranges of 0.1-2.5 {mu}g L{sup -1} for Cr(III) and 0.12-2.0 {mu}g L{sup -1} for Cr(VI). Detection limits of 0.02 {mu}g L{sup -1} for Cr(III) and 0.03 {mu}g L{sup -1} for Cr(VI) along with RSD values of 1.9% for Cr(III) and 2.5% for Cr(VI) (1.0 {mu}g L{sup -1}, n = 11) were obtained. The procedure was validated by analyzing a certified reference material of GBW08608 and further demonstrated by chromium speciation in river and tap water samples.

  5. Effect of food intake and co-administration of placebo self-nanoemulsifying drug delivery systems on the absorption of cinnarizine in healthy human volunteers.

    Science.gov (United States)

    Christiansen, Martin Lau; Holm, Rene; Abrahamsson, Bertil; Jacobsen, Jette; Kristensen, Jakob; Andersen, Jens Rikardt; Müllertz, Anette

    2016-03-10

    Positive food effects may be observed for low aqueous soluble compounds, these effects could potentially be circumvented using lipid based formulations. However, as all compounds are not chemically stable in lipid based systems, alternative dosage regimes could be investigated to evade the stability issue. The two aims for this present study were therefore; i) to investigate if a nutritional drink, Fresubin Energy®, could induce food effect in humans for the poorly soluble compound cinnarizine; and ii) to investigate if co-administration of a self-nano-emulsifying drug delivery systems (SNEDDS) with a conventional cinnarizine tablet could reduce the observed food-effect. A commercial conventional cinnarizine tablet was dosed to 10 healthy volunteers in a cross-over design in both fasted and fed state, with and without co-administration of a SNEDDS, with a one week wash-out period between dosing. The fed state was induced using a nutritional drink (Fresubin Energy®) and gastric emptying was assessed by administration of paracetamol as a marker. The pharmacokinetic analysis showed that the nutritional drink delayed the uptake and increased the fraction of absorbed cinnarizine, indicative of a food effect on the compound. This was in agreement with a previous dog study and indicates that the nutritional drink can be used for inducing the same level of food effect in humans. Though not statistically significant, the co-administration of SNEDDS exhibited a tendency towards a reduction of the observed food effect and an increased absorption of cinnarizine in the fasted state; based upon the individual ratios, which was not reflected in the mean data. However, the co-administration of SNEEDS in the fasted state, also induce a slower gastric emptying rate, which was observed as a delayed tmax for both cinnarizine and paracetamol. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Numerical analysis of specific absorption rate in the human head due to a 13.56 MHz RFID-based intra-ocular pressure measurement system

    International Nuclear Information System (INIS)

    Hirtl, Rene; Schmid, Gernot

    2013-01-01

    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. (note)

  7. Therapeutic plasma exchange versus double plasma molecular absorption system in hepatitis B virus-infected acute-on-chronic liver failure treated by entercavir: A prospective study.

    Science.gov (United States)

    Wan, Yue-Meng; Li, Yu-Hua; Xu, Zhi-Yuan; Yang, Jing; Yang, Li-Hong; Xu, Ying; Yang, Jin-Hui

    2017-12-01

    Therapeutic plasma exchange (TPE) and double plasma molecular absorption system (DPMAS) were two extracorporeal liver support systems. Few studies compared their efficacy profile. This study was to compare the efficacy of TPE and DPMAS on acute-on-chronic liver failure (ACLF) caused by hepatitis B virus (HBV-ACLF). 60 HBV-ACLF patients were enrolled and prospectively studied. All patients received entecavir therapy, and were assigned to TPE group (n = 33) and DPMAS group (n = 27). Primary end-points were the effects of TPE and DPMAS on liver function and serum inflammatory markers. Serum procalcitonin, interleukin (IL)-6, and high sensitive C-reactive protein (hsCRP) were significantly elevated in patients with HBV-ACLF. TPE achieved significantly higher removal rates of total bilirubin (TBIL, P = .002), direct bilirubin (DBIL, P = .006), and hsCRP (P = .010) than DPMAS, but DPMAS displayed lower loss rate of albumin (P = .000). TPE and DPMAS resulted in similarly increased serum IL-6 levels and comparable 12-week survivals (P > .05). Multivariate analysis showed that hospital stay (Relative Risk [RR]: 1.062, 95% Confidence Interval [CI]: 1.011-1.115, P = .016), prothrombin time (RR: 1.346, 95% CI: 1.077-1.726, P = .010), and international normalized ratio (RR: 0.013, 95% CI: 0.006-0.788, P = .041) were independent predictors for 12-week survival. Both TPE and DPMAS treatments were well-tolerated. Compared to DPMAS, TPE was more efficient in eliminating TBIL, DBIL, and hsCRP, but it was associated with higher loss rate of albumin. TPE and DPMAS were similar in improving 12-week survivals in HBV-ACLF. © 2017 Wiley Periodicals, Inc.

  8. VizieR Online Data Catalog: Quasars narrow absorption lines from SDSS (Chen+, 2015)

    Science.gov (United States)

    Chen, Z.-F.; Gu, Q.-S.; Chen, Y.-M.; Cao, Y.

    2017-11-01

    The Baryon Oscillation Spectroscopic Survey (BOSS: Eisenstein et al. 2011AJ....142...72E; Paris et al. 2012, Cat. VII/269) is the main dark-time legacy survey of the third stage of the SDSS, which used the same 2.5-m telescope (Gunn et al. 2006AJ....131.2332G; Ross et al. 2012, J/ApJS/199/3) as the first and second stages of the SDSS (hereafter SDSS-I/II). SDSS-I/II spectra have a wavelength coverage from 3800-9200Å with a spectral resolution of 1800-2200 (e.g. York et al. 2000AJ....120.1579Y). BOSS spectra span a range from 3600-10500Å at a resolution of 1300-2500 (Paris et al. 2012, Cat. VII/269). During the first two years, BOSS detected 87822 quasars over an area of 3275 deg2, including 7932 quasars that were observed by SDSS-I/II as well. Quasars observed by both SDSS-I/II and BOSS provide a remarkable chance to study the variabilities of absorption lines in a large population. Throughout this work, we take the quasar emission redshifts provided by Hewett & Wild (2010, J/MNRAS/405/2302, http://das.sdss.org/va/HewettWilddr7qso_newz/) directly. (2 data files).

  9. Enhancing effect of bile salts on gastrointestinal absorption of insulin ...

    African Journals Online (AJOL)

    Purpose: To investigate the effect of co-administration of two absorption enhancing bile alts, sodium glycocholate (NaGc) and sodium salicylate (NaSal), on insulin absorption via intestinal targeted delivery system. Methods: Insulin (10 IU/kg), associated with and without absorption enhancers (5 % enhancer solution of ...

  10. Cogeneration with gas turbine associated to the absorption refrigeration system: a computer program for exergy economics analysis; Cogeracao com turbina a gas associada ao sistema de refrigeracao por absorcao: um programa computacional para analise exergoeconomica

    Energy Technology Data Exchange (ETDEWEB)

    Antunes, Julio Santana [UNESP, Guaratingueta, SP (Brazil). Faculdade de Engenharia. Dept. de Matematica] E-mail: santana@feg.unesp.br; Silveira, Jose Luz; Balestieri, Jose Antonio Perrella [UNESP, Guaratingueta, SP (Brazil). Faculdade de Engenharia. Dept. de Energia

    2000-07-01

    This paper presents the development of a computer program for exergy and economic analysis of cogeneration systems applying gas turbine associated to the absorption refrigeration system. The computer program selects gas turbine systems viewing the operation under thermal parity through a data base composed by gas turbines commercially available in the market, under the ISO (International Standard Organization). The computer program corrects the system performance parameters selected for the installation local conditions. The exergy and economic analysis are made based on the lowest exergy manufacturing cost where the best system is considered. A case study of the computer program application is presented.

  11. The Redshifted Hydrogen Balmer and Metastable He 1 Absorption Line System in Mini-FeLoBAL Quasar SDSS J112526.12+002901.3: A Parsec-scale Accretion Inflow?

    Science.gov (United States)

    Shi, Xi-Heng; Jiang, Peng; Wang, Hui-Yuan; Zhang, Shao-Hua; Ji, Tuo; Liu, Wen-Juan; Zhou, Hong-Yan

    2016-10-01

    The accretion of the interstellar medium onto central super-massive black holes is widely accepted as the source of the gigantic energy released by the active galactic nuclei. However, few pieces of observational evidence have been confirmed directly demonstrating the existence of the inflows. The absorption line system in the spectra of quasar SDSS J112526.12+002901.3 presents an interesting example in which the rarely detected hydrogen Balmer and metastable He I absorption lines are found redshifted to the quasar's rest frame along with the low-ionization metal absorption lines Mg II, Fe II, etc. The repeated SDSS spectroscopic observations suggest a transverse velocity smaller than the radial velocity. The motion of the absorbing medium is thus dominated by infall. The He I* lines present a powerful probe to the strength of ionizing flux, while the Balmer lines imply a dense environment. With the help of photoionization simulations, we find that the absorbing medium is exposed to the radiation with ionization parameter U ≈ 10-1.8, and the density is n({{H}})≈ {10}9 {{cm}}-3. Thus the absorbing medium is located ˜4 pc away from the central engine. According to the similarity in the distance and physical conditions between the absorbing medium and the torus, we strongly propose the absorption line system as a candidate for the accretion inflow, which originates in the inner surface of the torus.

  12. Proposal and analysis of a high-efficiency combined desalination and refrigeration system based on the LiBr-H2O absorption cycle-Part 1: System configuration and mathematical model

    International Nuclear Information System (INIS)

    Wang Yongqing; Lior, Noam

    2011-01-01

    Simultaneous production of fresh water and refrigeration are often required, e.g. in warm-climate water-deficient regions, and this study is a proposal and analysis of an efficient way of producing both of them by consuming mainly low-grade heat. After introducing the configuration choice methodology, a combined refrigeration and water system, ARHP-MEE (absorption refrigeration heat pump and multi-effect evaporation desalter), which is the integration of a LiBr-H 2 O refrigeration unit, a LiBr-H 2 O heat pump, and a low-temperature multi-effect evaporation desalination unit, is proposed, and the mathematical model is presented and validated. The model serves for conducting a performance analysis of the combined system, reported in Part 2 of this two-part paper.

  13. A new parameterization for surface ocean light attenuation in Earth System Models: assessing the impact of light absorption by colored detrital material

    Science.gov (United States)

    Kim, G. E.; Pradal, M.-A.; Gnanadesikan, A.

    2015-03-01

    Light limitation can affect the distribution of biota and nutrients in the ocean. Light absorption by colored detrital material (CDM) was included in a fully coupled Earth System Model using a new parameterization for shortwave attenuation. Two model runs were conducted, with and without light attenuation by CDM. In a global average sense, greater light limitation associated with CDM increased surface chlorophyll, biomass and nutrients together. These changes can be attributed to the movement of biological productivity higher up the water column, which increased surface chlorophyll and biomass while simultaneously decreasing total biomass. Meanwhile, the reduction in biomass resulted in greater nutrient availability throughout the water column. Similar results were found on a regional scale in an analysis of the oceans by biome. In coastal regions, surface chlorophyll increased by 35% while total integrated phytoplankton biomass diminished by 18%. The largest relative increases in modeled surface chlorophyll and biomass in the open ocean were found in the equatorial biomes, while largest decreases in depth-integrated biomass and chlorophyll were found in the subpolar and polar biomes. This mismatch of surface and subsurface trends and their regional dependence was analyzed by comparing the competing factors of diminished light availability and increased nutrient availability on phytoplankton growth in the upper 200 m. Overall, increases in surface biomass were expected to accompany greater nutrient uptake and therefore diminish surface nutrients, but changes in light limitation decoupled trends between these two variables. Understanding changes in biological productivity requires both surface and depth-resolved information. Surface trends may be minimal or of the opposite sign to depth-integrated amounts, depending on the vertical structure of phytoplankton abundance.

  14. Development of new portable miniaturize solid phase microextraction of silver-APDC complex using micropipette tip in-syringe system couple with electrothermal atomic absorption spectrometry

    Science.gov (United States)

    Naeemullah; Kazi, Tasneem Gul; Afridi, Hassan Imran; Shah, Faheem; Arain, Sadaf Sadia; Arain, Salma Aslam; Panhwar, Abdul Haleem; Arain, Mariam Shahzadi; Samoon, Muhammad Kashif

    2016-02-01

    An innovative and simple miniaturized solid phase microextraction (M-SPME) method, was developed for preconcentration and determination of silver(I) in the fresh and waste water samples. For M-SPME, a micropipette tip packed with activated carbon cloth (ACC) as sorbent, in a syringe system. The size, morphology and elemental composition of ACC before and after adsorption of analyte have been characterized by scanning electron microscopy and energy dispersive spectroscopy. The sample solution treated with a complexing reagent, ammonium pyrrolidine dithiocarbamate (APDC), was drawn into the syringe filled with ACC and dispensed manually for 2 to 10 aspirating/dispensing cycle. Then the Ag- complex sorbed on the ACC in micropipette was quantitatively eluted by drawing and dispensing of different concentrations of acids for 2 to 5 aspirating/dispensing cycles. The extracted Ag ions with modifier were injected directly into the electrothermal atomic absorption spectrometry for analysis. The influence of different variables on the extraction efficiency, including the concentration of ligand, pH, sample volume, eluent type, concentration and volume was investigated. Validity and accuracy of the developed method was checked by the standard addition method. Reliability of the proposed me