WorldWideScience

Sample records for vapor mole fraction

  1. psychrometry: from partial pressures to mole fractions

    African Journals Online (AJOL)

    ES Obe

    1980-03-01

    Mar 1, 1980 ... as an ideal gas mixture. Partial pressures then become identical: to mole fractions and sets of psychometric parameters result from rather elementary thermodynamic relations. Search for more accurate data has long led to the realization that neither dry air nor pure water vapour behaves like an ideal gas,.

  2. Microwave Determination of Water Mole Fraction in Humid Gas Mixtures

    Science.gov (United States)

    Cuccaro, R.; Gavioso, R. M.; Benedetto, G.; Madonna Ripa, D.; Fernicola, V.; Guianvarc'h, C.

    2012-09-01

    A small volume (65 cm3) gold-plated quasi-spherical microwave resonator has been used to measure the water vapor mole fraction x w of H2O/N2 and H2O/air mixtures. This experimental technique exploits the high precision achievable in the determination of the cavity microwave resonance frequencies and is particularly sensitive to the presence of small concentrations of water vapor as a result of the high polarizability of this substance. The mixtures were prepared using the INRIM standard humidity generator for frost-point temperatures T fp in the range between 241 K and 270 K and a commercial two-pressure humidity generator operated at a dew-point temperature between 272 K and 291 K. The experimental measurements compare favorably with the calculated molar fractions of the mixture supplied by the humidity generators, showing a normalized error lower than 0.8.

  3. Vapor liquid fraction determination

    International Nuclear Information System (INIS)

    1980-01-01

    This invention describes a method of measuring liquid and vapor fractions in a non-homogeneous fluid flowing through an elongate conduit, such as may be required with boiling water, non-boiling turbulent flows, fluidized bed experiments, water-gas mixing analysis, and nuclear plant cooling. (UK)

  4. Electrical Activation Studies of Silicon Implanted Aluminum Gallium Nitride with High Aluminum Mole Fraction

    National Research Council Canada - National Science Library

    Moore, Elizabeth A

    2007-01-01

    ...) alloys, and represents a comprehensive analysis of the resulting material's electrical and optical properties as a function of Al mole fraction, anneal temperature, anneal time, and implantation dose...

  5. CO2 Monitoring and Background Mole Fraction at Zhongshan Station, Antarctica

    Directory of Open Access Journals (Sweden)

    Yulong Sun

    2014-09-01

    Full Text Available Background CO2 mole fraction and seasonal variations, measured at Zhongshan station, Antarctica, for 2010 through 2013, exhibit the expected lowest mole fraction in March with a peak in November. Irrespective of wind direction, the mole fraction of CO2 distributes evenly after polluted air from station operations is removed from the data sets. The daily range of average CO2 mole fraction in all four seasons is small. The monthly mean CO2 mole fraction at Zhongshan station is similar to that of other stations in Antarctica, with seasonal CO2 amplitudes in the order of 384–392 µmol∙mol−1. The annual increase in recent years is about 2 µmol∙mol−1∙yr−1. There is no appreciable difference between CO2 mole fractions around the coast of Antarctica and in the interior, showing that CO2 observed in Antarctica has been fully mixed in the atmosphere as it moves from the north through the southern hemisphere.

  6. Visualization of mole fraction distribution of slow jet forming stably stratified field

    International Nuclear Information System (INIS)

    Fumizawa, Motoo; Hishida, Makoto

    1990-01-01

    An experimental study has been performed to investigate the behavior of flow and mass transfer in gaseous slow jet in which buoyancy force opposed the flow forming stably stratified field. The study has been performed to understand the basic features of air ingress phenomena at pipe rupture accident of the high temperature gas-cooled reactor. A displacement fringe technique was adopted in Mach-Zehnder interferometer to visualize the mole fraction distribution. As the result, the followings were obtained: (1) The stably stratified fields were formed in the vicinity of the outlet of the slow jet. The penetration distance of the stably stratified fields increased with Froude number. (2) Mass fraction distributions in the stably stratified fields were well correlated with the present model using the ramp mole velocity profile. (author)

  7. Excited state intramolecular charge transfer reaction in binary mixtures of water and tertiary butanol (TBA): alcohol mole fraction dependence.

    Science.gov (United States)

    Pradhan, Tuhin; Ghoshal, Piue; Biswas, Ranjit

    2008-02-07

    The excited state intramolecular charge transfer reaction of 4-(1-azetidinyl)benzonitrile (P4C) has been studied in water-tertiary butanol (TBA) mixtures at different alcohol mole fractions by using steady state and time-resolved fluorescence spectroscopy. The ratio between the areas under the locally excited (LE) and charge transferred (CT) emission bands is found to exhibit a sharp rise at alcohol mole fraction approximately 0.04, a value at which several thermodynamic properties of this mixture is known to show anomalous change due to the enhancement of H-bonding network. The radiative rate associated with the LE emission also shows a maximum at this TBA mole fraction. Although the structural transition from the water-like tetrahedral network to the alcohol-like chain is reflected in the red shift of the absorption spectrum up to TBA mole fraction approximately 0.10, the emission bands (both LE and CT) show the typical nonideal alcohol mole fraction dependence at all TBA mole fractions. Quantum yield, CT radiative rate as well as transition moments also exhibit a nonideal alcohol mole fraction dependence. The time-resolved emission decay of P4C has been found to be biexponential at all TBA mole fractions, regardless of emission collection around either the LE or the CT bands. The time constant associated with the slow component (tau(slow)) shows a minimum at TBA mole fraction approximately 0.04, whereas such a minimum for the fast time constant, tau(fast) (representing the rate of LE --> CT conversion reaction) is not observed. The nonobservation of the minimum in tau(fast) might be due to the limited time resolution employed in our experiments.

  8. Indium mole fraction effect on the structural and optical properties of quaternary AlInGaN epilayers

    International Nuclear Information System (INIS)

    Liu, J P; Jin, R Q; Zhang, J C; Wang, J F; Wu, M; Zhu, J J; Zhao, D G; Wang, Y T; Yang, H

    2004-01-01

    AlInGaN quaternary epilayers with varying In mole fraction were investigated using triple-axis x-ray diffraction and photoluminescence measurements. The indium compositional fluctuation is enhanced with increasing In mole fraction, whereas the mosaicity of the AlInGaN epilayers is determined through the GaN template quality. Based on the analysis of the temperature dependence of the PL peak position, it is found that the localization effect strengthens with increasing In mole fraction due to the larger fluctuations of the In distribution. Increasing the influence of the localized state results in increasing the emission intensity and FWHM with the In content

  9. Study of atmospheric CH4 mole fractions at three WMO/GAW stations in China

    Science.gov (United States)

    Fang, Shuang-Xi; Zhou, Ling-Xi; Masarie, Kenneth A.; Xu, Lin; Rella, Chris W.

    2013-05-01

    CH4 mole fractions were continuously measured from 2009 to 2011 at three WMO/GAW stations in China (Lin'an, LAN; Longfengshan, LFS; and Waliguan, WLG) using three Cavity Ring Down Spectroscopy instruments. LAN and LFS are GAW regional measurement stations. LAN is located in China's most economically developed region, and LFS is in a rice production area (planting area > 40,000 km2). WLG is a global measurement station in remote northwest China. At LAN, high methane mole fractions are observed in all seasons. Surface winds from the northeast enhance CH4 values, with a maximum increase of 32 ± 15 ppb in summer. The peak to peak amplitude of the seasonal cycle is 77 ± 35 ppb. At LFS, the diurnal cycle amplitude is approximately constant throughout the year except summer, when a value of 196 ± 65 ppb is observed. CH4 values at LFS reach their peak in July, which is different from seasonal variations typically observed in the northern hemisphere. CH4 mole fractions at WLG show both the smallest values and the lowest variability. Maximum values occur during summer, which is different from other northern hemisphere WMO/GAW global stations. The seasonal cycle amplitude is 17 ± 11 ppb. The linear growth rates at LAN, LFS, and WLG are 8.0 ± 1.2, 7.9 ± 0.9, and 9.4 ± 0.2 ppb yr-1, respectively, which are all larger than the global mean over the same 3 year period. Results from this study attempt to improve our basic understanding of observed atmospheric CH4 in China.

  10. Resonant spin-flavor conversion of supernova neutrinos: Dependence on electron mole fraction

    International Nuclear Information System (INIS)

    Yoshida, Takashi; Takamura, Akira; Kimura, Keiichi; Yokomakura, Hidekazu; Kawagoe, Shio; Kajino, Toshitaka

    2009-01-01

    Detailed dependence of resonant spin-flavor (RSF) conversion of supernova neutrinos on electron mole fraction Y e is investigated. Supernova explosion forms a hot-bubble and neutrino-driven wind region of which electron mole fraction exceeds 0.5 in several seconds after the core collapse. When a higher resonance of the RSF conversion is located in the innermost region, flavor change of the neutrinos strongly depends on the sign of 1-2Y e . At an adiabatic high RSF resonance the flavor conversion of ν e ↔ν μ,τ occurs in Y e e >0.5 and inverted mass hierarchy. In other cases of Y e values and mass hierarchies, the conversion of ν e ↔ν μ,τ occurs. The final ν e spectrum is evaluated in the cases of Y e e >0.5 taking account of the RSF conversion. Based on the obtained result, time variation of the event number ratios of low ν e energy to high ν e energy is discussed. In normal mass hierarchy, an enhancement of the event ratio should be seen in the period when the electron fraction in the innermost region exceeds 0.5. In inverted mass hierarchy, on the other hand, a dip of the event ratio should be observed. Therefore, the time variation of the event number ratio is useful to investigate the effect of the RSF conversion.

  11. High accuracy measurements of dry mole fractions of carbon dioxide and methane in humid air

    Directory of Open Access Journals (Sweden)

    C. W. Rella

    2013-03-01

    Full Text Available Traditional techniques for measuring the mole fractions of greenhouse gases in the well-mixed atmosphere have required dry sample gas streams (dew point inter-laboratory compatibility goals (WMO, 2011a without drying the sample gas. In this paper, we present laboratory methodology for empirically deriving the water vapour correction factors, and we summarise a series of in-situ validation experiments comparing the measurements in humid gas streams to well-characterised dry-gas measurements. By using the manufacturer-supplied correction factors, the dry-mole fraction measurements have been demonstrated to be well within the GAW compatibility goals up to a water vapour concentration of at least 1%. By determining the correction factors for individual instruments once at the start of life, this water vapour concentration range can be extended to at least 2% over the life of the instrument, and if the correction factors are determined periodically over time, the evidence suggests that this range can be extended up to and even above 4% water vapour concentrations.

  12. Estimating regional methane surface fluxes: the relative importance of surface and GOSAT mole fraction measurements

    Directory of Open Access Journals (Sweden)

    A. Fraser

    2013-06-01

    Full Text Available We use an ensemble Kalman filter (EnKF, together with the GEOS-Chem chemistry transport model, to estimate regional monthly methane (CH4 fluxes for the period June 2009–December 2010 using proxy dry-air column-averaged mole fractions of methane (XCH4 from GOSAT (Greenhouse gases Observing SATellite and/or NOAA ESRL (Earth System Research Laboratory and CSIRO GASLAB (Global Atmospheric Sampling Laboratory CH4 surface mole fraction measurements. Global posterior estimates using GOSAT and/or surface measurements are between 510–516 Tg yr−1, which is less than, though within the uncertainty of, the prior global flux of 529 ± 25 Tg yr−1. We find larger differences between regional prior and posterior fluxes, with the largest changes in monthly emissions (75 Tg yr−1 occurring in Temperate Eurasia. In non-boreal regions the error reductions for inversions using the GOSAT data are at least three times larger (up to 45% than if only surface data are assimilated, a reflection of the greater spatial coverage of GOSAT, with the two exceptions of latitudes >60° associated with a data filter and over Europe where the surface network adequately describes fluxes on our model spatial and temporal grid. We use CarbonTracker and GEOS-Chem XCO2 model output to investigate model error on quantifying proxy GOSAT XCH4 (involving model XCO2 and inferring methane flux estimates from surface mole fraction data and show similar resulting fluxes, with differences reflecting initial differences in the proxy value. Using a series of observing system simulation experiments (OSSEs we characterize the posterior flux error introduced by non-uniform atmospheric sampling by GOSAT. We show that clear-sky measurements can theoretically reproduce fluxes within 10% of true values, with the exception of tropical regions where, due to a large seasonal cycle in the number of measurements because of clouds and aerosols, fluxes are within 15% of true fluxes. We evaluate our

  13. Current transport mechanism in graphene/AlGaN/GaN heterostructures with various Al mole fractions

    Science.gov (United States)

    Pandit, Bhishma; Seo, Tae Hoon; Ryu, Beo Deul; Cho, Jaehee

    2016-06-01

    The current transport mechanism of graphene formed on AlxGa1-xN/GaN heterostructures with various Al mole fractions (x = 0.15, 0.20, 0.30, and 0.40) is investigated. The current-voltage measurement from graphene to AlGaN/GaN shows an excellent rectifying property. The extracted Schottky barrier height of the graphene/AlGaN/GaN contacts increases with the Al mole fraction in AlGaN. However, the current transport mechanism deviates from the Schottky-Mott theory owing to the deterioration of AlGaN crystal quality at high Al mole fractions confirmed by reverse leakage current measurement.

  14. Current transport mechanism in graphene/AlGaN/GaN heterostructures with various Al mole fractions

    Directory of Open Access Journals (Sweden)

    Bhishma Pandit

    2016-06-01

    Full Text Available The current transport mechanism of graphene formed on AlxGa1−xN/GaN heterostructures with various Al mole fractions (x = 0.15, 0.20, 0.30, and 0.40 is investigated. The current–voltage measurement from graphene to AlGaN/GaN shows an excellent rectifying property. The extracted Schottky barrier height of the graphene/AlGaN/GaN contacts increases with the Al mole fraction in AlGaN. However, the current transport mechanism deviates from the Schottky-Mott theory owing to the deterioration of AlGaN crystal quality at high Al mole fractions confirmed by reverse leakage current measurement.

  15. High accuracy measurements of dry mole fractions of carbon dioxide and methane in humid air

    Science.gov (United States)

    Rella, C. W.; Chen, H.; Andrews, A. E.; Filges, A.; Gerbig, C.; Hatakka, J.; Karion, A.; Miles, N. L.; Richardson, S. J.; Steinbacher, M.; Sweeney, C.; Wastine, B.; Zellweger, C.

    2013-03-01

    Traditional techniques for measuring the mole fractions of greenhouse gases in the well-mixed atmosphere have required dry sample gas streams (dew point < -25 °C) to achieve the inter-laboratory compatibility goals set forth by the Global Atmosphere Watch programme of the World Meteorological Organisation (WMO/GAW) for carbon dioxide (±0.1 ppm in the Northern Hemisphere and ±0.05 ppm in the Southern Hemisphere) and methane (±2 ppb). Drying the sample gas to low levels of water vapour can be expensive, time-consuming, and/or problematic, especially at remote sites where access is difficult. Recent advances in optical measurement techniques, in particular cavity ring down spectroscopy, have led to the development of greenhouse gas analysers capable of simultaneous measurements of carbon dioxide, methane and water vapour. Unlike many older technologies, which can suffer from significant uncorrected interference from water vapour, these instruments permit accurate and precise greenhouse gas measurements that can meet the WMO/GAW inter-laboratory compatibility goals (WMO, 2011a) without drying the sample gas. In this paper, we present laboratory methodology for empirically deriving the water vapour correction factors, and we summarise a series of in-situ validation experiments comparing the measurements in humid gas streams to well-characterised dry-gas measurements. By using the manufacturer-supplied correction factors, the dry-mole fraction measurements have been demonstrated to be well within the GAW compatibility goals up to a water vapour concentration of at least 1%. By determining the correction factors for individual instruments once at the start of life, this water vapour concentration range can be extended to at least 2% over the life of the instrument, and if the correction factors are determined periodically over time, the evidence suggests that this range can be extended up to and even above 4% water vapour concentrations.

  16. Assessing filtering of mountaintop CO2 mole fractions for application to inverse models of biosphere-atmosphere carbon exchange

    Directory of Open Access Journals (Sweden)

    S. L. Heck

    2012-02-01

    Full Text Available There is a widely recognized need to improve our understanding of biosphere-atmosphere carbon exchanges in areas of complex terrain including the United States Mountain West. CO2 fluxes over mountainous terrain are often difficult to measure due to unusual and complicated influences associated with atmospheric transport. Consequently, deriving regional fluxes in mountain regions with carbon cycle inversion of atmospheric CO2 mole fraction is sensitive to filtering of observations to those that can be represented at the transport model resolution. Using five years of CO2 mole fraction observations from the Regional Atmospheric Continuous CO2 Network in the Rocky Mountains (Rocky RACCOON, five statistical filters are used to investigate a range of approaches for identifying regionally representative CO2 mole fractions. Test results from three filters indicate that subsets based on short-term variance and local CO2 gradients across tower inlet heights retain nine-tenths of the total observations and are able to define representative diel variability and seasonal cycles even for difficult-to-model sites where the influence of local fluxes is much larger than regional mole fraction variations. Test results from two other filters that consider measurements from previous and following days using spline fitting or sliding windows are overly selective. Case study examples showed that these windowing-filters rejected measurements representing synoptic changes in CO2, which suggests that they are not well suited to filtering continental CO2 measurements. We present a novel CO2 lapse rate filter that uses CO2 differences between levels in the model atmosphere to select subsets of site measurements that are representative on model scales. Our new filtering techniques provide guidance for novel approaches to assimilating mountain-top CO2 mole fractions in carbon cycle inverse models.

  17. Determination of mole fractions of ethyl-cellulose-containing monomers by NMR.

    Science.gov (United States)

    Kono, Hiroyuki

    2017-06-05

    Three samples of ethyl cellulose (EC) with different degrees of substitution (DS)-0.51, 1.41, and 2.28-were prepared by a slurry method using ethyl bromide as the etherification reagent. 1 H- 13 C HSQC and HSQC-TOCSY NMR spectral analysis allowed for complete assignment of the 1 H and 13 C chemical shifts, respectively, of eight anhydroglucose units (AGUs) comprising EC chains-un-, 2-mono-, 3-mono-, 6-mono-, 2,3-di-, 2,6-di-, 3,6-di-, and 2,3,6-tri-substituted AGUs. In addition, the lineshape of the quantitative 13 C NMR spectra of the three EC samples provided change in the mole fractions of these AGUs against DS, making it possible to estimate the reaction mechanism for the production of EC, elucidating reactivities of the hydroxyl groups at the 2, 3, and 6 positions of cellulose and interactions between the substituent groups within the same AGU and vicinal AGUs. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Comparison of atmospheric CO2 mole fractions and source-sink characteristics at four WMO/GAW stations in China

    Science.gov (United States)

    Cheng, Siyang; Zhou, Lingxi; Tans, Pieter P.; An, Xingqin; Liu, Yunsong

    2018-05-01

    As CO2 is a primary driving factor of climate change, the mole fraction and source-sink characteristics of atmospheric CO2 over China are constantly inferred from multi-source and multi-site data. In this paper, we compared ground-based CO2 measurements with satellite retrievals and investigated the source-sink regional representativeness at China's four WMO/GAW stations. The results indicate that, firstly, atmospheric CO2 mole fractions from ground-based sampling measurement and Greenhouse Gases Observing Satellite (GOSAT) products reveal similar seasonal variation. The seasonal amplitude of the column-averaged CO2 mole fractions is smaller than that of the ground-based CO2 at all stations. The extrema of the seasonal cycle of ground-based and column CO2 mole fractions are basically synchronous except a slight phase delay at Lin'an (LAN) station. For the two-year average, the column CO2 is lower than ground-based CO2, and both of them reveal the lowest CO2 mole fraction at Waliguan (WLG) station. The lowest (∼4 ppm) and largest (∼8 ppm) differences between the column and ground-based CO2 appear at WLG and Longfengshan (LFS) stations, respectively. The CO2 mole fraction and its difference between GOSAT and ground-based measurement are smaller in summer than in winter. The differences of summer column CO2 among these stations are also much smaller than their ground-based counterparts. In winter, the maximum of ground-based CO2 mole fractions and the greatest difference between the two (ground-based and column) datasets appear at the LFS station. Secondly, the representative areas of the monthly CO2 background mole fractions at each station were found by employing footprints and emissions. Smaller representative areas appeared at Shangdianzi (SDZ) and LFS, whereas larger ones were seen at WLG and LAN. The representative areas in summer are larger than those in winter at WLG and SDZ, but the situation is opposite at LAN and LFS. The representative areas for the

  19. Fractional condensation of biomass pyrolysis vapors

    NARCIS (Netherlands)

    Westerhof, Roel Johannes Maria; Brilman, Derk Willem Frederik; Garcia Perez, M.; Wang, Zhouhong; Oudenhoven, Stijn; van Swaaij, Willibrordus Petrus Maria; Kersten, Sascha R.A.

    2011-01-01

    In this paper, we have investigated the possibilities to steer the composition and, thus, the quality of pyrolysis liquids by the reactor temperature and the pyrolysis vapor condenser temperature. Pine wood was pyrolyzed in a 1 kg/h fluidized-bed pyrolysis reactor operated at 330 or 480 °C. The

  20. Point of net vapor generation and vapor void fraction in subcooled boiling

    International Nuclear Information System (INIS)

    Saha, P.; Zuber, N.

    1974-01-01

    An analysis is presented directed at predicting the point of net vapor generation and vapor void fraction in subcooled boiling. It is shown that the point of net vapor generation depends upon local conditions--thermal and fluid dynamic. Thus, at low mass flow rates the net vapor generation is determined by thermal conditions, whereas at high mass flow rates the phenomenon is hydrodynamically controlled. Simple criteria are derived which can be used to predict these local conditions for net vapor generation. These criteria are used to determine the vapor void fraction is subcooled boiling. Comparison between the results predicted by this analysis and experimental data presently available shows good agreement for wide range of operating conditions, fluids and geometries. (U.S.)

  1. Diffusion coefficients in 4-component mixture expressed explicitly in terms of binary diffusion coefficients and mole fractions

    International Nuclear Information System (INIS)

    Furuta, Hiroshi; Yamamoto, Ichiro

    1996-01-01

    Diffusion coefficients in 4-component mixture D ij (4) were expressed explicitly in terms of binary diffusion coefficients and mole fractions by solving a ratio of determinants defined by Hirschfelder et al. The explicit expressions of D ij (4) were divided into two terms, a term due to the i-j pairs of attention and a term common to all the pairs out of the 4 components. The two terms of D ij (4) had extended structures similar to corresponding those of D ij (3) respectively. (author)

  2. Muonium formation and the 'missing fraction' in vapors

    International Nuclear Information System (INIS)

    Fleming, D.G.; Arseneau, D.J.; Garner, D.M.; Senba, M.; Mikula, R.J.

    1983-06-01

    The vapor phase fractional polarizations of positive muons thermalizing as the muonium atom (Psub(M)) and in diamagnetic environments (Psub(D)) has been measured in H 2 O, CH 3 OH, C 6 H 14 , C 6 H 12 , CCl 4 , CHCl 3 , CH 2 Cl 2 and TMS, in order to compare with the corresponding fractions measured in the condensed phases. There is a marked contrast in every case, with the vapor phase results being largely understandable in terms of a charge exchange/hot atom model. Unlike the situation in the corresponding liquids, there is no permanent lost fraction in the vapor phase in the limit of even moderately high pressures (approximately 1 atm); at lower pressures, depolarization is due to hyperfine mixing and is believed to be well understood. For vapor phase CH 3 OH, C 6 H 14 , C 6 H 12 , and TMS the relative fractions are found to be pressure dependent, suggesting the importance of termolecular hot atom (or ion) reactions in the slowing-down process. For vapor phase H 2 O and the chloromethanes, the relative fractions are pressure independent. For CCl 4 , Psub(M) = Psub(D) approximately 0.5 in the vapor phase vs. Psub(D) = 1.0 in the liquid phase; fast thermal reactions of Mu likely contribute significantly to this difference in the liquid phase. For H 2 O, Psub(M) approximately 0.9 and Psub(D) approximately 0.1 in the vapor phase vs. Psub(D) approximately 0.6 and Psub(M) approximately 0.2 in the liquid phase. Water appears to be the one unequivocal case where the basic charge exchange/hot atom model is inappropriate in the condensed phase, suggesting, therefore, that radiation-induced 'spur' effects play a major role

  3. Long-term analysis of carbon dioxide and methane column-averaged mole fractions retrieved from SCIAMACHY

    Directory of Open Access Journals (Sweden)

    O. Schneising

    2011-03-01

    Full Text Available Carbon dioxide (CO2 and methane (CH4 are the two most important anthropogenic greenhouse gases contributing to global climate change. SCIAMACHY onboard ENVISAT (launch 2002 was the first and is now with TANSO onboard GOSAT (launch 2009 one of only two satellite instruments currently in space whose measurements are sensitive to CO2 and CH4 concentration changes in the lowest atmospheric layers where the variability due to sources and sinks is largest.

    We present long-term SCIAMACHY retrievals (2003–2009 of column-averaged dry air mole fractions of both gases (denoted XCO2 and XCH4 derived from absorption bands in the near-infrared/shortwave-infrared (NIR/SWIR spectral region focusing on large-scale features. The results are obtained using an upgraded version (v2 of the retrieval algorithm WFM-DOAS including several improvements, while simultaneously maintaining its high processing speed. The retrieved mole fractions are compared to global model simulations (CarbonTracker XCO2 and TM5 XCH4 being optimised by assimilating highly accurate surface measurements from the NOAA/ESRL network and taking the SCIAMACHY averaging kernels into account. The comparisons address seasonal variations and long-term characteristics.

    The steady increase of atmospheric carbon dioxide primarily caused by the burning of fossil fuels can be clearly observed with SCIAMACHY globally. The retrieved global annual mean XCO2 increase agrees with CarbonTracker within the error bars (1.80±0.13 ppm yr−1 compared to 1.81±0.09 ppm yr−1. The amplitude of the XCO2 seasonal cycle as retrieved by SCIAMACHY, which is 4.3±0.2 ppm for the Northern Hemisphere and 1.4±0.2 ppm for the Southern Hemisphere, is on average about 1 ppm larger than for CarbonTracker.

    An investigation of the boreal forest carbon uptake during the

  4. 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

  5. Effect of the growth temperature and the AlN mole fraction on In incorporation and properties of quaternary III-nitride layers grown by molecular beam epitaxy

    International Nuclear Information System (INIS)

    Fernandez-Garrido, S.; Pereiro, J.; Munoz, E.; Calleja, E.; Redondo-Cubero, A.; Gago, R.; Bertram, F.; Christen, J.; Luna, E.; Trampert, A.

    2008-01-01

    Indium incorporation into wurtzite (0001)-oriented In x Al y Ga 1-x-y N layers grown by plasma-assisted molecular beam epitaxy was studied as a function of the growth temperature (565-635 deg. C) and the AlN mole fraction (0.01< y<0.27). The layer stoichiometry was determined by Rutherford backscattering spectrometry (RBS). RBS shows that indium incorporation decreased continuously with increasing growth temperature due to thermally enhanced dissociation of In-N bonds and for increasing AlN mole fractions. High resolution x-ray diffraction and transmission electron microscopy (TEM) measurements did not show evidence of phase separation. The mosaicity of the quaternary layers was found to be mainly determined by the growth temperature and independent on alloy composition within the range studied. However, depending on the AlN mole fraction, nanometer-sized composition fluctuations were detected by TEM. Photoluminescence spectra showed a single broad emission at room temperature, with energy and bandwidth S- and W-shaped temperature dependences typical of exciton localization by alloy inhomogeneities. Cathodoluminescence measurements demonstrated that the alloy inhomogeneities, responsible of exciton localization, occur on a lateral length scale below 150 nm, which is corroborated by TEM

  6. The mole

    CERN Multimedia

    CERN PhotoLab

    1974-01-01

    The mole continued its way around the SPS ring ... and on 31 July emerged where it started from, having completed its 7 kilometre journey without ever veering more than a couple of centimetres from its schedule path.

  7. Effect of Al mole fraction on structural and electrical properties of AlxGa1-xN/GaN heterostructures grown by plasma-assisted molecular beam epitaxy

    International Nuclear Information System (INIS)

    Hussein, A. SH.; Hassan, Z.; Thahab, S.M.; Ng, S.S.; Hassan, H. Abu; Chin, C.W.

    2011-01-01

    The effect of Al mole fractions on the structural and electrical properties of Al x Ga 1-x N/GaN thin films grown by plasma-assisted molecular beam epitaxy (PA-MBE) on Si (1 1 1) substrates has been investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), and current-voltage (I-V) measurements. X-ray results revealed that the AlGaN/GaN/AlN was epitaxially grown on Si substrate. By applying Vegard's law, the Al mole fractions of Al x Ga 1-x N samples were found to be 0.11, 0.24, 0.30 and 0.43, respectively. The structural and morphology results indicated that there is a relatively larger tensile strain for the sample with the smallest Al mole fraction; while a smaller compressive strain and larger grain size appear with Al mole fraction equal to 0.30. The strain gets relaxed with the highest Al mole fraction sample. Finally, the linear relationship between the barrier height and Al mole fraction was obtained.

  8. Quantification of urban atmospheric boundary layer greenhouse gas dry mole fraction enhancements in the dormant season: Results from the Indianapolis Flux Experiment (INFLUX

    Directory of Open Access Journals (Sweden)

    Natasha L. Miles

    2017-06-01

    Full Text Available We assess the detectability of city emissions via a tower-based greenhouse gas (GHG network, as part of the Indianapolis Flux (INFLUX experiment. By examining afternoon-averaged results from a network of carbon dioxide (CO2, methane (CH4, and carbon monoxide (CO mole fraction measurements in Indianapolis, Indiana for 2011–2013, we quantify spatial and temporal patterns in urban atmospheric GHG dry mole fractions. The platform for these measurements is twelve communications towers spread across the metropolitan region, ranging in height from 39 to 136 m above ground level, and instrumented with cavity ring-down spectrometers. Nine of the sites were deployed as of January 2013 and data from these sites are the focus of this paper. A background site, chosen such that it is on the predominantly upwind side of the city, is utilized to quantify enhancements caused by urban emissions. Afternoon averaged mole fractions are studied because this is the time of day during which the height of the boundary layer is most steady in time and the area that influences the tower measurements is likely to be largest. Additionally, atmospheric transport models have better performance in simulating the daytime convective boundary layer compared to the nighttime boundary layer. Averaged from January through April of 2013, the mean urban dormant-season enhancements range from 0.3 ppm CO2 at the site 24 km typically downwind of the edge of the city (Site 09 to 1.4 ppm at the site at the downwind edge of the city (Site 02 to 2.9 ppm at the downtown site (Site 03. When the wind is aligned such that the sites are downwind of the urban area, the enhancements are increased, to 1.6 ppm at Site 09, and 3.3 ppm at Site 02. Differences in sampling height affect the reported urban enhancement by up to 50%, but the overall spatial pattern remains similar. The time interval over which the afternoon data are averaged alters the calculated urban enhancement by an average of 0.4 ppm

  9. Correlation analysis of reactivity in the oxidation of methionine by benzimidazolium fluorochromate in different mole fractions of acetic acid–water mixture

    Directory of Open Access Journals (Sweden)

    S. Sheik Mansoor

    2016-09-01

    Full Text Available The kinetics of oxidation of methionine (Met by benzimidazolium fluorochromate (BIFC has been studied in the presence of chloroacetic acid. The reaction is first order with respect to methionine, BIFC and acid. The reaction rate has been determined at different temperatures and activation parameters calculated. With an increase in the mole fraction of acetic acid in its aqueous mixture, the rate increases. The solvent effect has been analyzed using the Kamlet’s multi parametric equation. A correlation of data with the Kamlet–Taft solvatochromic parameters (α, β, π∗ suggests that the specific solute–solvent interactions play a major role in governing the reactivity. The reaction does not induce polymerization of acrylonitrile. A suitable mechanism has been proposed.

  10. Vapor pressure and vapor fractionation of silicate melts of tektite composition

    Science.gov (United States)

    Walter, Louis S.; Carron, M.K.

    1964-01-01

    The total vapor pressure of Philippine tektite melts of approximately 70 per cent silica has been determined at temperatures ranging from 1500 to 2100??C. This pressure is 190 ?? 40 mm Hg at 1500??C, 450 ?? 50 mm at 1800??C and 850 ?? 70 mm at 2100?? C. Determinations were made by visually observing the temperature at which bubbles began to form at a constant low ambient pressure. By varying the ambient pressure, a boiling point curve was constructed. This curve differs from the equilibrium vapor pressure curve due to surface tension effects. This difference was evaluated by determining the equilibrium bubble size in the melt and calculating the pressure due to surface tension, assuming the latter to be 380 dyn/cm. The relative volatility from tektite melts of the oxides of Na, K, Fe, Al and Si has been determined as a function of temperature, total pressure arid roughly, of oxygen fugacity. The volatility of SiO2 is decreased and that of Na2O and K2O is increased in an oxygen-poor environment. Preliminary results indicate that volatilization at 2100??C under atmospheric pressure caused little or no change in the percentage Na2O and K2O. The ratio Fe3 Fe2 of the tektite is increased in ambient air at a pressure of 9 ?? 10-4 mm Hg (= 106.5 atm O2, partial pressure) at 2000??C. This suggests that tektites were formed either at lower oxygen pressures or that they are a product of incomplete oxidation of parent material with a still lower ferricferrous ratio. ?? 1964.

  11. Liquid-Vapor Argon Isotope Fractionation from the Triple Point to the Critical Point

    DEFF Research Database (Denmark)

    Phillips, J. T.; Linderstrøm-Lang, C. U.; Bigeleisen, J.

    1972-01-01

    are compared at the same molar volume. The isotope fractionation factor α for 36Ar∕40Ar between liquid and vapor has been measured from the triple point to the critical temperature. The results are compared with previous vapor pressure data, which cover the range 84–102°K. Although the agreement is within....... The fractionation factor approaches zero at the critical temperature with a nonclassical critical index equal to 0.42±0.02.〈∇2Uc〉/ρc in liquid argon is derived from the experimental fractionation data and calculations of 〈∇2Ug〉/ρg for a number of potential functions for gaseous argon....

  12. Uranium isotope fractionation resulting from UF6 vapor distillation from containers

    International Nuclear Information System (INIS)

    Hedge, W.D.; Turner, C.M.

    1985-01-01

    This empirical study for possible isotopic fractionation due to UF 6 vapor distillation from valved containers was performed to determine the effects of repeated vapor sampling. Four different experiments were performed, each of which varied by the method of measuring the isotopic contents and/or by the difference in temperature gradients as follows: The ratio of the parent UF 6 to the desublimed UF 6 collected at liquid nitrogen temperature and homogenized was measured by sampling the containers. The ratio of the parent UF 6 to the desublimed UF 6 collected at liquid nitrogen temperature and homogenized was measured by direct comparison to each other without subsampling. The ratio of the parent UF 6 to the desublimed UF 6 collected at liquid nitrogen and ice-water temperatures and homogenized was measured by indirect comparison to a common UF 6 reference material without subsampling. The ratio of the parent UF 6 to the desublimed UF 6 collected at liquid nitrogen temperature without homogenizing was measured by indirect comparison to a common UF 6 reference. Gas-phase, relative mass spectrometry was used for all isotopic measurements. Results of the study indicate that fractionation does occur. The U-235 isotope becomes more enriched in the parent container as the UF 6 is vaporized from it and desublimed into the receiving cylinder; i.e., the vaporized fraction is enriched in the U-238 isotope. The degree of fractionation indicates that the separation is due to the U-238 isotope of UF 6 having a higher vapor pressure than the U-235 isotope of UF 6 . 3 refs., 4 figs., 4 tabs

  13. Tunable diode laser absorption spectroscopy-based tomography system for on-line monitoring of two-dimensional distributions of temperature and H{sub 2}O mole fraction

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Lijun, E-mail: lijunxu@buaa.edu.cn; Liu, Chang; Jing, Wenyang; Cao, Zhang [School of Instrument Science and Opto-Electronic Engineering, Beihang University, Beijing 100191 (China); Ministry of Education’s Key Laboratory of Precision Opto-Mechatronics Technology, Beijing 100191 (China); Xue, Xin; Lin, Yuzhen [School of Energy and Power Engineering, Beihang University, Beijing 100191 (China)

    2016-01-15

    To monitor two-dimensional (2D) distributions of temperature and H{sub 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{sub 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{sup −1} (1343.3 nm) and 7185.6 cm{sup −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{sub 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{sub 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.

  14. Pervaporation membrane bioreactor with permeate fractional condensation and mechanical vapor compression for energy efficient ethanol production

    International Nuclear Information System (INIS)

    Fan, Senqing; Xiao, Zeyi; Li, Minghai; Li, Sizhong

    2016-01-01

    Graphical abstract: Pervaporation membrane bioreactor with permeate partial condensation and mechanical vapor compression is developed for an energy efficient ethanol production. - Highlights: • PVMBR-MVC for energy efficient ethanol production. • Process separation factor of 20–44 for ethanol achieved by fractional condensation. • Energy production of 20.25 MJ and hourly energy production of 56.25 kJ/h achieved. • Over 50% of energy saved in PVMBR-MVC compared with PVMBR-LTC. • Integrated heat pump with COP of 7–9 for the energy recovery of the permeate. - Abstract: Improved process separation factor and heat integration are two key issues to increase the energy efficiency of ethanol production in a pervaporation membrane bioreactor (PVMBR). A PVMBR with permeate fractional condensation and mechanical vapor compression was developed for energy efficient ethanol production. A condensation model based on the mass balance and thermodynamic equilibrium in the partial vacuum condenser was developed for predicting the purification performance of the permeate vapor. Three runs of ethanol fermentation-pervaporation experiment were carried out and ethanol concentration of higher than 50 wt% could be achieved in the final condensate, with the separation factor of the process for ethanol increased to 20. Ethanol production could be enhanced in the bioreactor and 17.1 MJ of the energy could be produced in per liter of fermentation broth, owing to 27.0 MJ/kg heating value of the recovered ethanol. Compared with the traditional pervaporation process with low temperature condensation for ethanol production, 50% of the energy would be saved in the process. The energy consumption would be further reduced, if the available energy of the permeate vapor was utilized by integrating the mechanical vapor compression heat pump.

  15. Estimating surface CO2 fluxes from space-borne CO2 dry air mole fraction observations using an ensemble Kalman Filter

    Directory of Open Access Journals (Sweden)

    S. Dance

    2009-04-01

    Full Text Available We have developed an ensemble Kalman Filter (EnKF to estimate 8-day regional surface fluxes of CO2 from space-borne CO2 dry-air mole fraction observations (XCO2 and evaluate the approach using a series of synthetic experiments, in preparation for data from the NASA Orbiting Carbon Observatory (OCO. The 32-day duty cycle of OCO alternates every 16 days between nadir and glint measurements of backscattered solar radiation at short-wave infrared wavelengths. The EnKF uses an ensemble of states to represent the error covariances to estimate 8-day CO2 surface fluxes over 144 geographical regions. We use a 12×8-day lag window, recognising that XCO2 measurements include surface flux information from prior time windows. The observation operator that relates surface CO2 fluxes to atmospheric distributions of XCO2 includes: a the GEOS-Chem transport model that relates surface fluxes to global 3-D distributions of CO2 concentrations, which are sampled at the time and location of OCO measurements that are cloud-free and have aerosol optical depths 2 profiles to XCO2, accounting for differences between nadir and glint measurements, and the associated scene-dependent observation errors. We show that OCO XCO2 measurements significantly reduce the uncertainties of surface CO2 flux estimates. Glint measurements are generally better at constraining ocean CO2 flux estimates. Nadir XCO2 measurements over the terrestrial tropics are sparse throughout the year because of either clouds or smoke. Glint measurements provide the most effective constraint for estimating tropical terrestrial CO2 fluxes by accurately sampling fresh continental outflow over neighbouring oceans. We also present results from sensitivity experiments that investigate how flux estimates change with 1 bias and unbiased errors, 2 alternative duty cycles, 3 measurement density and correlations, 4 the spatial resolution of estimated flux estimates, and 5 reducing the length of the lag window and the

  16. Nitrogen doping efficiency during vapor phase epitaxy of 4H-SiC

    Energy Technology Data Exchange (ETDEWEB)

    Rowland, L.B.; Brandt, C.D. [Northrop Grumman Science and Technology Center, Pittsburgh, PA (United States); Burk, A.A. Jr. [Northrop Grumman Advanced Technology Lab., Baltimore, MD (United States)

    1998-06-01

    This work examines the interrelationships among doping efficiency, mole fraction, and Si/C ratio for intentional doping of 4H-SiC during vapor phase epitaxy using N{sub 2}. For four Si/C ratios, the doping concentration increased linearly as a function of increasing N{sub 2} partial pressure with a slope of 1.0 {+-} 0.03. Variation of propane mole fraction while the SiH{sub 4} and N{sub 2} mole fractions were kept constant revealed two different modes of nitrogen incorporation, corresponding to carbon-rich and silicon-rich conditions. (orig.) 14 refs.

  17. Catalytic Flash Pyrolysis of Biomass Using Different Types of Zeolite and Online Vapor Fractionation

    KAUST Repository

    Imran, Ali

    2016-03-11

    Bio-oil produced from conventional flash pyrolysis has poor quality and requires expensive upgrading before it can be used as a transportation fuel. In this work, a high quality bio-oil has been produced using a novel approach where flash pyrolysis, catalysis and fractionation of pyrolysis vapors using two stage condensation are combined in a single process unit. A bench scale unit of 1 kg/h feedstock capacity is used for catalytic pyrolysis in an entrained down-flow reactor system equipped with two-staged condensation of the pyrolysis vapor. Zeolite-based catalysts are investigated to study the effect of varying acidities of faujasite Y zeolites, zeolite structures (ZSM5), different catalyst to biomass ratios and different catalytic pyrolysis temperatures. Low catalyst/biomass ratios did not show any significant improvements in the bio-oil quality, while high catalyst/biomass ratios showed an effective deoxygenation of the bio-oil. The application of zeolites decreased the organic liquid yield due to the increased production of non-condensables, primarily hydrocarbons. The catalytically produced bio-oil was less viscous and zeolites were effective at cracking heavy molecular weight compounds in the bio-oil. Acidic zeolites, H-Y and H-ZSM5, increased the desirable chemical compounds in the bio-oil such as phenols, furans and hydrocarbon, and reduced the undesired compounds such as acids. On the other hand reducing the acidity of zeolites reduced some of the undesired compounds in the bio-oil such as ketones and aldehydes. The performance of H-Y was superior to that of the rest of zeolites studied: bio-oil of high chemical and calorific value was produced with a high organic liquid yield and low oxygen content. H-ZSM5 was a close competitor to H-Y in performance but with a lower yield of bio-oil. Online fractionation of catalytic pyrolysis vapors was employed by controlling the condenser temperature and proved to be a successful process parameter to tailor the

  18. Liquid--vapor isotope fractionation factors in argon--krypton binary mixtures

    International Nuclear Information System (INIS)

    Lee, M.W.; Neufeld, P.; Bigeleisen, J.

    1977-01-01

    An equilibrium isotope effect has been studied as a continuous function of the potential field acting on the atom undergoing isotopic exchange. This has been accomplished through a study of the liquid vapor isotope fractionation factors for both, 36 Ar/ 40 Ar and 80 Kr/ 84 Kr in a series of binary mixtures which span the range between the pure components at 117.5 0 K. The 36 Ar/ 40 Ar fractionation factor increases (linearly) from (lnα)2.49 x 10 -3 in pure liquid argon to 2.91 x 10 -3 in an infinitely dilute solution in liquid krypton. Conversely, the 80 Kr/ 84 Kr fractionation factor decreases (linearly) from (lnα)0.98 x 10 -3 in pure liquid krypton to 0.64 x 10 -3 in an infinetely dilute solution in pure liquid argon. The mean force constants 2 U>/sub c/ on both argon and krypton atoms in the mixtures are derived from the respective isotope fractionation factors.The mean force constants for argon and krypton as a function of composition have been calculated by a modified corresponding states theory which uses the pure liquids as input parameters. The discrepancy is 8 percent at X/sub Ar/ + O. A systematic set of calculations has been made of 2 U> (Ar) and 2 U> (Kr) as a function of composition using radial distribution functions generated by the Weeks--Chandler--Anderson perturbation theory

  19. Dependence of the interband transitions on the in mole fraction and the applied electric field in In xGa1-xAs/In0.52Al0.48As multiple quantum wells

    International Nuclear Information System (INIS)

    Kim, J.H.; Woo, J.T.; Lee, I.; Kim, T.W.; Yoo, K.H.; Kim, M.D.; Ram-Mohan, L.R.

    2005-01-01

    Transmission electron microscopy (TEM) and photocurrent (PC) measurements were carried out to investigate the microstructural properties and excitonic transitions in In x Ga 1-x As/In 0.52 Al 0.48 As multiple quantum wells (MQWs) for x = 0.54, 0.57 and 0.60. TEM images showed that high-quality 11-period In x Ga 1-x As/In 0.52 Al 0.48 As MQWs had high-quality heterointerfaces. The results for the PC spectra at 300 K showed that the peaks corresponding to the excitonic transitions from the ground state electronic sub-band to the ground state heavy-hole band (E 1 -HH 1 ) and the ground state electronic sub-band to the ground state light-hole band (E 1 -LH 1 ) became closer to each other with decreasing In mole fraction and that E 1 -HH 1 and E 1 -LH 1 excitonic peaks shifted to longer wavelength with increasing applied electric field. The calculated values of the E 1 -HH 1 interband transition energies were in qualitative agreement with those obtained form the PC measurements with and without applied electric field. These results can be helpful in understanding potential applications of In x Ga 1-x As/In y Al 1-y As MQWs dependent on In mole fraction and applied electric field in long-wavelength optoelectronic devices

  20. Mole sieve cycle optimization

    Energy Technology Data Exchange (ETDEWEB)

    Croteau, P. [Petro-Canada Oil and Gas, Inc., Calgary, AB (Canada)

    2004-07-01

    Maturing gas basins and declining reservoirs have prompted the search for energy and cost reduction initiatives to maintain operation sustainability. This paper discusses the development of an algorithm to improve the efficiency of the Brazeau mole sieve dehydration system. Details of the operating unit and an outline of the system were provided, as well as an operator interface. The main objectives of the research were to reduce the number of corresponding regeneration cycles; reduce annual energy requirements; and extend the life of the dessicant. Reductions were anticipated at 35 per cent, leading towards fuel savings of $45,000 a year, and carbon dioxide reductions of 670 tonnes a year. However, significant barriers were also noted, including operations, maintenance and equipment replacement issues. Equations of state were used to estimate vapor pressure or water content in gases. Approximate water content was measured with gas flow rate. The resulting algorithm was implemented using a basic best fit curve generated for one variable with a correction factor applied as a second variable. Data books were provided to present water content of hydrocarbon gas, with implementation procedures. Benefits of the new system included longer service life and reduced chemical and outside service costs, and reduced lost production during sieve changes. Additional benefits included enhanced distributed computing system (DCS) interfaces within plant operations; extension of the adsorption cycle via the functionality of the algorithm; and the fact that during a plant upset, the algorithm froze cycle sequencing and eliminated the possibility of switching the beds and repeating regeneration. The improved system resulted in savings of $87,000. tabs, figs.

  1. Potential use of the non-random distribution of N2 and N2O mole masses in the atmosphere as a tool for tracing atmospheric mixing and isotope fractionation processes

    International Nuclear Information System (INIS)

    Well, R.; Langel, R.; Reineking, A.

    2002-01-01

    The variation in the natural abundance of 15 N in atmospheric gas species is often used to determine the mixing of trace gases from different sources. With conventional budget calculations one unknown quantity can be determined if the remaining quantities are known. From 15 N tracer studies in soils with highly enriched 15 N-nitrate a procedure is known to calculate the mixing of atmospheric and soil derived N 2 based on the measurement of the 30/28 and 29/28 ratios in gas samples collected from soil covers. Because of the non-random distribution of the mole masses 30 N 2 , 29 N 2 and 28 N 2 in the mixing gas it is possible to calculate two quantities simultaneously, i.e. the mixing ratio of atmospheric and soil derived N 2 , and the isotopic signature of the soil derived N 2 . Routine standard measurements of laboratory air had suggested a non-random distribution of N 2 -mole masses. The objective of this study was to investigate and explain the existence of non-random distributions of 15 N 15 N, 14 N 15 N and 14 N 14 N in N 2 and N 2 O in environmental samples. The calculation of theoretical isotope data resulting from hypothetical mixing of two sources differing in 15 N natural abundance demonstrated, that the deviation from an ideal random distribution of mole masses is not detectable with the current precision of mass spectrometry. 15 N-analysis of N 2 or N 2 O was conducted with randomised and non-randomised replicate samples of different origin. 15 N abundance as calculated from 29/28 ratios were generally higher in randomised samples. The differences between the treatments ranged between 0.05 and 0.17 δper mille 15 N. It was concluded that the observed randomisation effect is probably caused by 15 N 15 N fractionation during environmental processes. (author)

  2. Vapor-Liquid Equilibrium in the Mixture 1,1-Difluoroethane C2H4F2 + C4H8 2-Methylpropene (EVLM1131, LB5730_E)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume A 'Binary Liquid Systems of Nonelectrolytes I' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Vapor-Liquid Equilibrium in the Mixture 1,1-Difluoroethane C2H4F2 + C4H8 2-Methylpropene (EVLM1131, LB5730_E)' providing data from direct measurement of pressure and mole fraction in vapor phase at variable mole fraction in liquid phase and constant temperature.

  3. Mole gun injury.

    Science.gov (United States)

    Pistré, V; Rezzouk, J

    2013-09-01

    A mole gun is a weapon, which is used to trap and kill moles. This report provides an overview of the state of knowledge of mole gun injuries, comparable to blast injuries caused by fireworks, explosive or gunshot. Over a 2-year period, the authors reported their experience with ten hand injuries caused by mole gun. Radial side of the hand was often concerned, particularly the thumb. The authors explain their choices in the management of such lesions. Surgery was performed primarily and a large debridement currently seemed to offer the best outcome for the patient. Blast, crush, burns and lacerations may explain the higher rate of amputation to the digits. A long period of physiotherapy, specifically of the hand, was needed before the patient could return to work. This ballistic hand trauma encountered by surgeons requires knowledge and understanding of these injuries. It should be in accordance with firearms law because of severe injuries encountered and possible lethal wounds. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  4. Site-specific and multielement approach to the determination of liquid-vapor isotope fractionation parameters. The case of alcohols

    International Nuclear Information System (INIS)

    Moussa, I.; Naulet, N.; Martin, M.L.; Martin, G.J.

    1990-01-01

    Isotope fractionation phenomena occurring at the natural abundance level in the course of liquid-vapor transformation have been investigated by using the SNIF-NMR method (site-specific natural isotope fractionation studied by NMR) which has a unique capability of providing simultaneous access to fractionation parameters associated with different molecular isotopomers. This new approach has been combined with the determination of overall carbon and hydrogen fractionation effects by isotope ratio mass spectrometry (IRMS). The results of distillation and evaporation experiments of alcohols performed in technical conditions of practical interest have been analyzed according to the Rayleigh-type model. In order to check the performance of the column, unit fractionation factors were measured beforehand for water and for the hydroxylic sites of methanol and ethanol for which liquid-vapor equilibrium constants were already known. Inverse isotope effects are determined in distillation experiments for the overall carbon isotope ratio and for the site-specific hydrogen isotope ratios associated with the methyl and methylene sites of methanol and ethanol. In contrast, normal isotope effects are produced by distillation for the hydroxylic sites and by evaporation for all the isotopic ratios

  5. Composition and carrier-concentration dependence of the electronic structure of InyGa1-yAs1-xNx films with nitrogen mole fraction of less than 0.012

    International Nuclear Information System (INIS)

    Kang, Youn-Seon; Robins, Lawrence H.; Birdwell, Anthony G.; Shapiro, Alexander J.; Thurber, W. Robert; Vaudin, Mark D.; Fahmi, M.M.E.; Bryson, Damian; Mohammad, S. Noor

    2005-01-01

    The electronic structure of Si-doped In y Ga 1-y As 1-x N x films on GaAs substrates, grown by nitrogen-plasma-assisted molecular-beam epitaxy, was examined by photoreflectance (PR) spectroscopy at temperatures between 20 and 300 K. The films were approximately 0.5 μm thick and had nitrogen mole fraction between x=0.0014 and x=0.012, measured indirectly by a secondary-ion-mass spectrometry calibration; indium mole fraction between y=0.052 and y=0.075, measured by electron-dispersive x-ray spectroscopy; and carrier concentration between 2x10 16 and 1.1x10 18 cm -3 , measured by Hall effect. Three critical-point transitions were identified by PR: the fundamental band gap (highest valence band to the lowest conduction band); the spin-orbit split valence band to the lowest conduction band; and the highest valence band to a nitrogen impurity band (above the lowest conduction band). The measured critical-point energies were described by a band anticrossing (BAC) model with the addition of a Burstein-Moss band-filling term. The fitted BAC parameters were similar to previously reported values. The N impurity level was located 0.3004±0.0101 eV above the conduction-band edge at 20 K and 0.3286±0.0089 eV above the conduction-band edge at 295 K. The BAC interaction parameter was 2.588±0.071 eV. From the small magnitude of the Burstein-Moss energy shift with increasing carrier concentration, it was inferred that the carrier concentration probed by PR is reduced from the bulk (Hall-effect) carrier concentration by a reduction factor of 0.266±0.145. The PR lines broadened with increasing carrier concentration; the line broadening tracked the predicted Burstein-Moss energy shift for the bulk carrier concentration. The surface-normal lattice constants of the films were measured by x-ray diffraction. Comparison of the measured lattice constants with Vegard's law showed the presence of tensile strain (in the surface-normal direction) with magnitude between 1.5x10 -3 and 3.0x10

  6. Catalytic Flash Pyrolysis of Biomass Using Different Types of Zeolite and Online Vapor Fractionation

    KAUST Repository

    Imran, Ali; Bramer, Eddy; Seshan, Kulathuiyer; Brem, Gerrit

    2016-01-01

    -staged condensation of the pyrolysis vapor. Zeolite-based catalysts are investigated to study the effect of varying acidities of faujasite Y zeolites, zeolite structures (ZSM5), different catalyst to biomass ratios and different catalytic pyrolysis temperatures. Low

  7. Trend of Complete Hydatidiform Mole

    Directory of Open Access Journals (Sweden)

    K Thapa

    2010-03-01

    Full Text Available INTRODUCTION: Complete Hydatidiform mole is one of the most frequent abnormal pregnancies. This review studies the trend of complete mole in Paropakar Maternity and Women's hospital and clinical ability to detect it. METHODS: This is a retrospective study of 504 cases of complete hydatidiform mole recorded at Paropakar maternity and women's hospital, Kathmandu, during 2058-2065 B.S. Medical records were reviewed and incidence, clinical presentation and method of diagnosis were studied. RESULTS: During the study period, there were 13,9117 births and 504 complete moles, 12 partial moles, 48 persistent gestational tumours, six choriocarcinoma and four invasive moles recorded in the hospital. The incidence of complete mole was one per 276 births. It was prevalent among women younger than 29 years (80% and among the primigravidae (36.7%. More than 90% women presented in the first half of their pregnancy and vaginal bleeding was the main complaint (68.3%. Suction evacuation, dilation and evacuation followed by sharp curettage and abdominal hysterectomy were performed in 80.6%, 17.6% and 1.2% of the women respectively. Persistent mole and choriocarcinoma developed in 9.5% and 0.4% respectively. CONCLUSIONS: Complete mole has the highest incidence. It affects mostly younger women and presents with vaginal bleeding most of the time, usually in the first half of their pregnancy. Keywords: complete hydatidiform mole, gestational trophoblastic disease, persistent gestational tumours.

  8. Knudsen cell vaporization of rare earth nitrides: enthalpy of vaporization of HoN098

    International Nuclear Information System (INIS)

    Brown, R.C.; Clark, N.J.

    1975-01-01

    The enthalpy of vaporization of HoN 0 . 98 was measured by the weight-loss Knudsen cell technique using Motzfeldt-Whitman extrapolations to zero orifice area. A third-law enthalpy of vaporization of HoN 0 . 98 of 155.9 +- 5 kcal mole -1 was obtained compared to a second-law value of 162.0 +- 5 kcal mole -1 . Similar measurements on the nitrides of samarium, erbium, and ytterbium gave third-law enthalpies of vaporization of 126.8 +-- 5 kcal mole -1 ; 159.6 +- 5 kcal mole -1 , and 121.0 +- 5 kcal mole -1 , respectively. 7 tables

  9. Geochemical mole-balance modeling with uncertain data

    Science.gov (United States)

    Parkhurst, David L.

    1997-01-01

    Geochemical mole-balance models are sets of chemical reactions that quantitatively account for changes in the chemical and isotopic composition of water along a flow path. A revised mole-balance formulation that includes an uncertainty term for each chemical and isotopic datum is derived. The revised formulation is comprised of mole-balance equations for each element or element redox state, alkalinity, electrons, solvent water, and each isotope; a charge-balance equation and an equation that relates the uncertainty terms for pH, alkalinity, and total dissolved inorganic carbon for each aqueous solution; inequality constraints on the size of the uncertainty terms; and inequality constraints on the sign of the mole transfer of reactants. The equations and inequality constraints are solved by a modification of the simplex algorithm combined with an exhaustive search for unique combinations of aqueous solutions and reactants for which the equations and inequality constraints can be solved and the uncertainty terms minimized. Additional algorithms find only the simplest mole-balance models and determine the ranges of mixing fractions for each solution and mole transfers for each reactant that are consistent with specified limits on the uncertainty terms. The revised formulation produces simpler and more robust mole-balance models and allows the significance of mixing fractions and mole transfers to be evaluated. In an example from the central Oklahoma aquifer, inclusion of up to 5% uncertainty in the chemical data can reduce the number of reactants in mole-balance models from seven or more to as few as three, these being cation exchange, dolomite dissolution, and silica precipitation. In another example from the Madison aquifer, inclusion of the charge-balance constraint requires significant increases in the mole transfers of calcite, dolomite, and organic matter, which reduce the estimated maximum carbon 14 age of the sample by about 10,000 years, from 22,700 years to

  10. Fractionation of families of major, minor, and trace metals across the melt-vapor interface in volcanic exhalations

    Science.gov (United States)

    Hinkley, T.K.; Le Cloarec, M.-F.; Lambert, G.

    1994-01-01

    Chemical families of metals fractionate systematically as they pass from a silicate melt across the interface with the vapor phase and on into a cooled volcanic plume. We measured three groups of metals in a small suite of samples collected on filters from the plumes of Kilauea (Hawaii, USA), Etna (Sicily), and Merapi (Java) volcanoes. These were the major, minor, and trace metals of the alkali and alkaline earth families (K, Rb, Cs, Ca, Sr, Ba), a group of ordinarily rare metals (Cd, Cu, In, Pb, Tl) that are related by their chalcophile affinities, and the radon daughter nuclides 210Po, 210Bi, and 210Pb. The measurements show the range and some details of systematic melt-vapor fractionation within and between these groups of metals. In the plumes of all three volcanoes, the alkali metals are much more abundant than the alkaline earth metals. In the Kilauea plume, the alkali metals are at least six times more abundant than the alkaline earth metals, relative to abundances in the melt; at Etna, the factor is at least 300. Fractionations within each family are, commonly, also distinctive; in the Kilauea plume, in addition to the whole alkaline earth family being depleted, the heaviest metals of the family (Sr, Ba) are progressively more depleted than the light metal Ca. In plumes of fumaroles at Merapi, K/Cs ratios were approximately three orders of magnitude smaller than found in other earth materials. This may represent the largest observed enrichment of the "light ion lithophile" (LIL) metals. Changes in metal ratios were seen through the time of eruption in the plumes of Kilauea and Etna. This may reflect degree of degassing of volatiles, with which metals complex, from the magma bodies. At Kilauea, the changes in fractionation were seen over about three years; fractionation within the alkaline earth family increased, and that between the two families decreased, over that time. All of the ordinarily rare chalcophile metals measured are extremely abundant in

  11. Ice-vapor equilibrium fractionation factor of hydrogen and oxygen isotopes

    DEFF Research Database (Denmark)

    Ellehøj, Mads Dam; Steen-Larsen, Hans Christian; Johnsen, Sigfus Johann

    2013-01-01

    RATIONALE: The equilibrium fractionation factors govern the relative change in the isotopic composition during phase transitions of water. The commonly used results, which were published more than 40 years ago, are limited to a minimum temperature of -33 degrees C. This limits the reliability...... values, with a temperature dependency in accordance with theory for equilibrium fractionation. We obtain the following expressions for the temperature dependency of the fractionation coefficients: ln(alpha(delta 2H)) = 0.2133 - 203.10/T + 48888/T-2 ln(alpha(delta 18O)) = 0.0831 - 49.192/T + 8312.5/T2...... Compared with previous experimental work, a significantly larger for H-2 is obtained while, for O-18, is larger for temperatures below -20 degrees C and slightly lower for temperatures above this. CONCLUSIONS: Using the new values for alpha, a Rayleigh distillation model shows significant changes in both...

  12. Modeling and measurement of boiling point elevation during water vaporization from aqueous urea for SCR applications

    International Nuclear Information System (INIS)

    Dan, Ho Jin; Lee, Joon Sik

    2016-01-01

    Understanding of water vaporization is the first step to anticipate the conversion process of urea into ammonia in the exhaust stream. As aqueous urea is a mixture and the urea in the mixture acts as a non-volatile solute, its colligative properties should be considered during water vaporization. The elevation of boiling point for urea water solution is measured with respect to urea mole fraction. With the boiling-point elevation relation, a model for water vaporization is proposed underlining the correction of the heat of vaporization of water in the urea water mixture due to the enthalpy of urea dissolution in water. The model is verified by the experiments of water vaporization as well. Finally, the water vaporization model is applied to the water vaporization of aqueous urea droplets. It is shown that urea decomposition can begin before water evaporation finishes due to the boiling-point elevation

  13. Modeling and measurement of boiling point elevation during water vaporization from aqueous urea for SCR applications

    Energy Technology Data Exchange (ETDEWEB)

    Dan, Ho Jin; Lee, Joon Sik [Seoul National University, Seoul (Korea, Republic of)

    2016-03-15

    Understanding of water vaporization is the first step to anticipate the conversion process of urea into ammonia in the exhaust stream. As aqueous urea is a mixture and the urea in the mixture acts as a non-volatile solute, its colligative properties should be considered during water vaporization. The elevation of boiling point for urea water solution is measured with respect to urea mole fraction. With the boiling-point elevation relation, a model for water vaporization is proposed underlining the correction of the heat of vaporization of water in the urea water mixture due to the enthalpy of urea dissolution in water. The model is verified by the experiments of water vaporization as well. Finally, the water vaporization model is applied to the water vaporization of aqueous urea droplets. It is shown that urea decomposition can begin before water evaporation finishes due to the boiling-point elevation.

  14. Collision cross sections and equilibrium fractions of ions and atoms in metal vapor targets. Project progress report, June 1, 1979-May 31, 1980

    International Nuclear Information System (INIS)

    Morgan, T.J.

    1980-01-01

    The objective of this program is to measure atomic collision cross sections and equilibrium fractions of ions and atoms in metal vapor targets. The goal is to obtain experimental information on atomic collision processes relevant to the Magnetic Fusion Energy Program. In particular, in connection with the development of double charge exchange D - ion sources, we are measuring D - formation cross sections in alkaline-earth metal vapor targets. During the period covered in this report we have measured electron transfer cross sections for 3-40 keV D + ions and D 0 atoms in collision with calcium vapor

  15. Cross sections and equilibrium fractions of deuterium ions and atoms in metal vapors. Progress report, June 1, 1978-May 31, 1979

    International Nuclear Information System (INIS)

    Morgan, T.J.

    1979-01-01

    The purpose of this program is to measure cross sections and equilibrium fractions of deuterium ions and atoms in metal vapors. In particular, in connection with double charge exchange D - ion sources, there is concern with D - formation in alkaline-earth vapor targets. Also, in connection with possible metal vapor contamination in the system, there is concern with cross sections for high energy D + , D 0 and D - collisions with these metal vapors. Results from this research will fill in a gap in knowledge of single and double charge transfer and multiple collision processes in alkaline-earth targets and provide a better understanding of D - formation mechanisms. A list of publications is included. 6 references

  16. Shaping of the axial power density distribution in the core to minimize the vapor volume fraction at the outlet of the VVER-1200 fuel assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Savander, V. I.; Shumskiy, B. E., E-mail: borisshumskij@yandex.ru [National Research Nuclear University MEPhI (Russian Federation); Pinegin, A. A. [National Research Center Kurchatov Institute (Russian Federation)

    2016-12-15

    The possibility of decreasing the vapor fraction at the VVER-1200 fuel assembly outlet by shaping the axial power density field is considered. The power density field was shaped by axial redistribution of the concentration of the burnable gadolinium poison in the Gd-containing fuel rods. The mathematical modeling of the VVER-1200 core was performed using the NOSTRA computer code.

  17. The effect of vapor polarity and boiling point on breakthrough for binary mixtures on respirator carbon.

    Science.gov (United States)

    Robbins, C A; Breysse, P N

    1996-08-01

    This research evaluated the effect of the polarity of a second vapor on the adsorption of a polar and a nonpolar vapor using the Wheeler model. To examine the effect of polarity, it was also necessary to observe the effect of component boiling point. The 1% breakthrough time (1% tb), kinetic adsorption capacity (W(e)), and rate constant (kv) of the Wheeler model were determined for vapor challenges on carbon beds for both p-xylene and pyrrole (referred to as test vapors) individually, and in equimolar binary mixtures with the polar and nonpolar vapors toluene, p-fluorotoluene, o-dichlorobenzene, and p-dichlorobenzene (referred to as probe vapors). Probe vapor polarity (0 to 2.5 Debye) did not systematically alter the 1% tb, W(e), or kv of the test vapors. The 1% tb and W(e) for test vapors in binary mixtures can be estimated reasonably well, using the Wheeler model, from single-vapor data (1% tb +/- 30%, W(e) +/- 20%). The test vapor 1% tb depended mainly on total vapor concentration in both single and binary systems. W(e) was proportional to test vapor fractional molar concentration (mole fraction) in mixtures. The kv for p-xylene was significantly different (p boiling point; however, these differences were apparently of limited importance in estimating 1% tb for the range of boiling points tested (111 to 180 degrees C). Although the polarity and boiling point of chemicals in the range tested are not practically important in predicting 1% tb with the Wheeler model, an effect due to probe boiling point is suggested, and tests with chemicals of more widely ranging boiling point are warranted. Since the 1% tb, and thus, respirator service life, depends mainly on total vapor concentration, these data underscore the importance of taking into account the presence of other vapors when estimating respirator service life for a vapor in a mixture.

  18. Moles

    Science.gov (United States)

    ... This can be done with a split thickness skin graft from some other normal area of the body. ... several reported cases of melanoma developing underneath a skin graft from nevus cells left behind. Occasionally, thickened scars ...

  19. Isotope Fractionation of Water During Evaporation Without Condensation

    International Nuclear Information System (INIS)

    Cappa, Christopher D.; Drisdell, Walter S.; Smith, Jared D.; Saykally, Richard J.; Cohen, Ronald C.

    2005-01-01

    The microscopic events engendering liquid water evaporation have received much attention over the last century, but remain incompletely understood. We present measurements of isotope fractionation occurring during free molecular evaporation from liquid microjets and show that the isotope ratios of evaporating molecules exhibit dramatic differences from equilibrium vapor values, strong variations with the solution deuterium mole fraction, and a clear temperature dependence. These results indicate the existence of an energetic barrier to evaporation and that the evaporation coefficient of water is less than unity. These new insights into water evaporation promise to advance our understanding of the processes that control the formation and lifetime of clouds in the atmosphere.

  20. Vapor-liquid equilibrium of the Mg(NO3)2-HNO3-H2O system

    International Nuclear Information System (INIS)

    Thompson, B.E.; Derby, J.J.; Stalzer, E.H.

    1983-06-01

    The vapor-liquid equilibrium of the Mg(NO 3 ) 2 -HNO 3 -H 2 O system in concentrations of 0 to 70 wt % Mg(NO 3 ) 2 and 0 to 75 wt % HNO 3 at atmospheric pressure was correlated by two approaches. One was based on a dissociation equilibrium expression in which the activities of the reacting species (HNO 3 , NO 3 - , and H + ) were approximated with mole fractions. The activity coefficients of the undissociated HNO 3 and H 2 O were correlated as functions of the concentrations of magnesium nitrate and nitric acid by second-order polynomials. The average absolute difference between predicted and experimental values was 8% for the mole fraction of acid in the vapor and 8 0 K for the bubble-point temperature. The second approach was to correlate the mean ionic rational activity coefficient of water with a form of the excess Gibbs energy composed of two terms. One term, a function of the ionic strength, accounts for the coulombic (ionic) interactions; the other term accounts for the non-coulombic (molecular) interactions. The average absolute difference between predicted and experimental values was 9% for the mole fraction of acid in the vapor, and 10 0 K for the bubble-point temperature

  1. Evaluation of (vapor + liquid) equilibria for the binary systems (1-octanol + cyclohexane) and (1-octanol + n-hexane), at low alcohol compositions

    International Nuclear Information System (INIS)

    Ovejero, Gabriel; Dolores Romero, M.; Diez, Eduardo; Lopes, Tania; Diaz, Ismael

    2008-01-01

    Isobaric (vapor + liquid) equilibrium at p = 101.32 kPa of pressure has been determined for the systems (1-octanol + cyclohexane) and (1-octanol + n-hexane), at low alcohol mole fractions. These data were satisfactorily correlated, using ASPEN PLUS commercial software, with Wilson, NRTL, and UNIQUAC activity coefficient models to obtain the binary interaction parameters of both mixtures. Also, UNIFAC group contribution method was employed to predict the equilibrium of both mixtures. With regression values an accurate knowledge of (vapor + liquid) equilibrium for both mixtures can be reached in a range of 1-octanol mole fractions less than 0.1. UNIFAC method provides acceptable results for (1-octanol + n-hexane) system but not for (1-octanol + cyclohexane) system

  2. Evaluation of (vapor + liquid) equilibria for the binary systems (1-octanol + cyclohexane) and (1-octanol + n-hexane), at low alcohol compositions

    Energy Technology Data Exchange (ETDEWEB)

    Ovejero, Gabriel [Grupo de Catalisis y Procesos de Separacion (CyPS), Departamento de Ingenieria Quimica, Facultad de C. Quimicas, Universidsad Complutense de Madrid, Avda. Complutense s/n, 28040 Madrid (Spain)], E-mail: govejero@quim.ucm.es; Dolores Romero, M.; Diez, Eduardo; Lopes, Tania; Diaz, Ismael [Grupo de Catalisis y Procesos de Separacion (CyPS), Departamento de Ingenieria Quimica, Facultad de C. Quimicas, Universidsad Complutense de Madrid, Avda. Complutense s/n, 28040 Madrid (Spain)

    2008-11-15

    Isobaric (vapor + liquid) equilibrium at p = 101.32 kPa of pressure has been determined for the systems (1-octanol + cyclohexane) and (1-octanol + n-hexane), at low alcohol mole fractions. These data were satisfactorily correlated, using ASPEN PLUS commercial software, with Wilson, NRTL, and UNIQUAC activity coefficient models to obtain the binary interaction parameters of both mixtures. Also, UNIFAC group contribution method was employed to predict the equilibrium of both mixtures. With regression values an accurate knowledge of (vapor + liquid) equilibrium for both mixtures can be reached in a range of 1-octanol mole fractions less than 0.1. UNIFAC method provides acceptable results for (1-octanol + n-hexane) system but not for (1-octanol + cyclohexane) system.

  3. Fractionation in position-specific isotope composition during vaporization of environmental pollutants measured with isotope ratio monitoring by 13C nuclear magnetic resonance spectrometry

    International Nuclear Information System (INIS)

    Julien, Maxime; Parinet, Julien; Nun, Pierrick; Bayle, Kevin; Höhener, Patrick; Robins, Richard J.; Remaud, Gérald S.

    2015-01-01

    Isotopic fractionation of pollutants in terrestrial or aqueous environments is a well-recognized means by which to track different processes during remediation. As a complement to the common practice of measuring the change in isotope ratio for the whole molecule using isotope ratio monitoring by mass spectrometry (irm-MS), position-specific isotope analysis (PSIA) can provide further information that can be exploited to investigate source and remediation of soil and water pollutants. Position-specific fractionation originates from either degradative or partitioning processes. We show that isotope ratio monitoring by 13 C NMR (irm- 13 C NMR) spectrometry can be effectively applied to methyl tert-butylether, toluene, ethanol and trichloroethene to obtain this position-specific data for partitioning. It is found that each compound exhibits characteristic position-specific isotope fractionation patterns, and that these are modulated by the type of evaporative process occurring. Such data should help refine models of how remediation is taking place, hence back-tracking to identify pollutant sources. - Highlights: • Position-Specific Isotope Analysis (PSIA) by 13 C NMR spectrometry. • PSIA on isotope fractionation during several vaporization processes. • PSIA for isotope profiling in environment pollutants. • Intramolecular 13 C reveal normal and inverse effects, bulk values being unchanged. - PSIA in pollutants during evaporation processes shows more detailed information for discerning the nature of the process involved than does bulk isotope measurements

  4. Suppression of Vapor Explosions in a Water-Molten-Tin System by Augmentation of the Void Fraction

    International Nuclear Information System (INIS)

    Meeks, Michael K.; Baker, Michael C.; Bonazza, Riccardo

    2000-01-01

    Experiments were performed to determine the likelihood of a vapor explosion when injecting an inert gas (nitrogen) and a coolant (water) into a pool of molten metal (tin) in a large-scale chamber (∼20 kg fuel). The injection flow rates of the water and nitrogen gas were the principal experimental variables, with average water flow rates up to 0.05 x 10 -3 m 3 /s and gas flow rates ranging from 0.33 x 10 -3 to 1.67 x 10 -3 m 3 /s. Of 35 successful experiments, 11 resulted in an explosive interaction, as determined by audible signals, videotape, and accelerometer data. The main objective of the investigation was to determine the existence of a boundary between explosive and nonexplosive regions in the water-gas flow rate plane: Such a boundary was indeed identified and approximated by a straight line. Two experiments in which explosive interactions were obtained in the low water/gas flow regions after a relatively long time of coolant injection (∼5 to 10 s) demonstrate the hitherto undervalued importance of the temporal variable

  5. Soil Moisture (SMAP) and Vapor Pressure Deficit Controls on Evaporative Fraction over the Continental U.S.

    Science.gov (United States)

    Salvucci, G.; Rigden, A. J.; Gianotti, D.; Entekhabi, D.

    2017-12-01

    We analyze the control over evapotranspiration (ET) imposed by soil moisture limitations and stomatal closure due to vapor pressure deficit (VPD) across the United States using estimates of satellite-derived soil moisture from SMAP and a meteorological, data-driven ET estimate over a two year period at over 1000 locations. The ET data are developed independent of soil moisture using the emergent relationship between the diurnal cycle of the relative humidity profile and ET based on ETRHEQ (Salvucci and Gentine (2013), PNAS, 110(16): 6287-6291, Rigden and Salvucci, 2015, WRR, 51(4): 2951-2973; Rigden and Salvucci, 2017, GCB, 23(3) 1140-1151). The key advantage of using this approach to estimate ET is that no measurements of surface limiting factors (soil moisture, leaf area, canopy conductance) are required; instead, ET is estimated from only meteorological data. The combination of these two independent datasets allows for a unique spatial analysis of the control on ET imposed by the availability of soil moisture vs. VPD. Spatial patterns of limitations are inferred by fitting the ETRHEQ-inferred surface conductance to a weighted sum of a Jarvis type stomatal conductance model and bare soil evaporation conductance model, with separate moisture-dependent evaporation efficiency relations for bare soil and vegetation. Spatial patterns are visualized by mapping the optimal curve fitting coefficients and by conducting sensitivity analyses of the resulting fitted model across the Unites States. Results indicate regional variations in rate-limiting factors, and suggest that in some areas the VPD effect on stomatal closure is strong enough to induce a decrease in ET under projected climate change, despite an increase in atmospheric drying (and thus evaporative demand).

  6. Moles and Mole Control on British Farms, Amenities and Gardens after Strychnine Withdrawal

    Directory of Open Access Journals (Sweden)

    Sandra E. Baker

    2016-06-01

    Full Text Available Moles are considered pests in Britain, but this issue has been little studied. Lower welfare standards have been tolerated for moles than for most other managed wild mammal species, as use of both the controversial poison, strychnine, and unregulated traps have been permitted. Strychnine was withdrawn in 2006 and there were fears that mole populations would increase as a result. In 2007, we conducted a comprehensive, nationwide survey of land manager perceptions, opinions and behaviour regarding moles and mole control on farms, amenities and domestic gardens in Britain. We surveyed 2150 land managers (achieving a 59% response rate and ground-truthed 29 responses. Moles were reported to be present on most farms and amenities, and 13% of gardens, and were more common in lighter soils. Where present, moles were usually considered pests, this being more likely in Wales, Scotland and northern England, on livestock and mixed farms, and on large, high-value amenities, e.g., racecourses and golf courses. Mole control followed similar patterns to mole presence. More control may occur than is economically, and therefore potentially ethically, justified. Control should be more carefully considered and, where necessary, more effectively targeted. Kill-trapping was the favoured recent and future method on farms and amenities, even if strychnine was to be reintroduced; however, because mole traps are currently unregulated, some might not meet current welfare standards if tested. We found no evidence for an increase in moles since a farm questionnaire survey conducted in 1992; this could have wider implications for future wildlife management policy changes.

  7. Effects of gas residence time of CH4/H2 on sp2 fraction of amorphous carbon films and dissociated methyl density during radical-injection plasma-enhanced chemical vapor deposition

    Science.gov (United States)

    Sugiura, Hirotsugu; Jia, Lingyun; Kondo, Hiroki; Ishikawa, Kenji; Tsutsumi, Takayoshi; Hayashi, Toshio; Takeda, Keigo; Sekine, Makoto; Hori, Masaru

    2018-06-01

    Quadruple mass spectrometric measurements of CH3 density during radical-injection plasma-enhanced chemical vapor deposition to consider the sp2 fraction of amorphous carbon (a-C) films were performed. The sp2 fraction of the a-C films reached a minimum of 46%, where the CH3 density was maximum for a residence time of 6 ms. The sp2 fraction of the a-C films was tailored with the gaseous phase CH3 density during the deposition. This knowledge is useful for understanding the formation mechanism of bonding structures in the a-C films, which enables the precise control of their electronic properties.

  8. Mass-Dependent and -Independent Fractionation of Mercury Isotope during Gas-Phase Oxidation of Elemental Mercury Vapor by Atomic Cl and Br.

    Science.gov (United States)

    Sun, Guangyi; Sommar, Jonas; Feng, Xinbin; Lin, Che-Jen; Ge, Maofa; Wang, Weigang; Yin, Runsheng; Fu, Xuewu; Shang, Lihai

    2016-09-06

    This study presents the first measurement of Hg stable isotope fractionation during gas-phase oxidation of Hg(0) vapor by halogen atoms (Cl(•), Br(•)) in the laboratory at 750 ± 1 Torr and 298 ± 3 K. Using a relative rate technique, the rate coefficients for Hg(0)+Cl(•) and Hg(0)+Br(•) reactions are determined to be (1.8 ± 0.5) × 10(-11) and (1.6 ± 0.8) × 10(-12) cm(3) molecule(-1) s(-1), respectively. Results show that heavier isotopes are preferentially enriched in the remaining Hg(0) during Cl(•) initiated oxidation, whereas being enriched in the product during oxidation by Br(•). The fractionation factors for (202)Hg/(198)Hg during the Cl(•) and Br(•) initiated oxidations are α(202/198) = 0.99941 ± 0.00006 (2σ) and 1.00074 ± 0.00014 (2σ), respectively. A Δ(199)Hg/Δ(201)Hg ratio of 1.64 ± 0.30 (2σ) during oxidation of Hg(0) by Br atoms suggests that Hg-MIF is introduced by the nuclear volume effect (NVE). In contrast, the Hg(0) + Cl(•) reaction produces a Δ(199)Hg/Δ(201)Hg-slope of 1.89 ± 0.18 (2σ), which in addition to a high degree of odd-mass-number isotope MIF suggests impacts from MIF effects other than NVE. This reaction also exhibits significant MIF of (200)Hg (Δ(200)Hg, up to -0.17‰ in the reactant) and is the first physicochemical process identified to trigger (200)Hg anomalies that are frequently detected in atmospheric samples.

  9. Subsurface Sampling and Sensing Using Burrowing Moles

    Science.gov (United States)

    Stoker, C. R.; Richter, L.; Smith, W. H.

    2004-01-01

    Finding evidence for life on Mars will likely require accessing the subsurface since the Martian surface is both hostile to life and to preservation of biosignatures due to the cold dry conditions, the strong W environment, and the presence of strong oxidants. Systems are needed to probe beneath the sun and oxidant baked surface of Mars and return samples to the surface for analysis or to bring the instrument sensing underground. Recognizing this need, the European Space Agency incorporated a small subsurface penetrometer or Mole onto the Beagle 2 Mars lander. Had the 2003 landing been successful, the Mole would have collected samples from 1-1.5 m depth and delivered them to an organic analysis instrument on the surface. The de- vice called the Planetary Underground Tool (PLUTO), also measured soil mechanical and thermophysical properties. Constrained by the small mass and volume allowance of the Beagle lander, the PLUTO mole was a slender cylinder only 2 cm diameter and 28 cm long equipped with a small sampling device designed to collect samples and bring them to the surface for analysis by other instrument. The mass of the entire system including deployment mechanism and tether was 1/2 kg. sensor package underground to make in situ measurements. The Mars Underground Mole (MUM) is a larger Mole based on the PLUTO design but incorporating light collection optics that interface to a fiber optic cable in the tether that transmits light to a combined stimulated emission Raman Spectrometer and Short Wave Infrared (SWIR) reflectance Spectrometer with sensitivity from 0.7 to 2.5 micrometers. This instrument is called the Dual Spectral Sensor and uses a Digital Array Scanning Interferometer as the sensor technology, a type of fourier transform interferometer that uses fixed element prisms and thus is highly rugged compared to a Michaelson interferometer. Due to the size limitations of an on-Mole instrument compartment, and the availability of a tether, the sensor head

  10. Fractionation of Cu and Mo isotopes caused by vapor-liquid partitioning, evidence from the Dahutang W-Cu-Mo ore field

    Science.gov (United States)

    Yao, Junming; Mathur, Ryan; Sun, Weidong; Song, Weile; Chen, Huayong; Mutti, Laurence; Xiang, Xinkui; Luo, Xiaohong

    2016-05-01

    The study presents δ65Cu and δ97Mo isotope values from cogenetic chalcopyrite and molybdenite found in veins and breccias of the Dahutang W-Cu-Mo ore field in China. The samples span a 3-4 km range. Both isotopes show a significant degree of fractionation. Cu isotope values in the chalcopyrite range from -0.31‰ to +1.48‰, and Mo isotope values in the molybdenite range from -0.03‰ to +1.06‰. For the cogenetic sulfide veined samples, a negative slope relationship exists between δ65Cu and δ97Mo values, which suggest a similar fluid history. Rayleigh distillation models the vein samples' change in isotope values. The breccia samples do not fall on the trend, thus indicating a different source mineralization event. Measured fluid inclusion and δD and δ18O data from cogenetic quartz indicate changes in temperature, and mixing of fluids do not appear to cause the isotopic shifts measure. Related equilibrium processes associated with the partitioning of metal between the vapor-fluid in the hydrothermal system could be the probable cause for the relationship seen between the two isotope systems.

  11. Reproductive features of the eastern mole (Scalopus aquaticus) and star-nose mole (Condylura cristata).

    Science.gov (United States)

    Bedford, J M; Mock, O B; Nagdas, S K; Winfrey, V P; Olson, G E

    1999-11-01

    Since moles are closely related to shrews, the gametes and reproductive tracts of the star-nose mole (Condylura cristata) and the eastern mole (Scalopus aquaticus) were examined to gain further insight into unusual reproductive traits of the Soricidae. Moles display many of these soricid traits, but with some important differences. The cumulus oophorus of Scalopus, ovulated about 16 h after hCG injection, was largely dispersed by hyaluronidase and, though quite dense, was nevertheless more similar to that of higher mammals than to the compact 'ball of the soricid cumulus. Within the female tract in these moles, approximately 85% of the length of the oviduct comprises a narrow ampulla with numerous differentiated crypts that, in shrews, house spermatozoa. However, in contrast to shrews, moles produce considerably larger numbers of spermatozoa, which challenges the proposal that, in shrews, oviductal sperm crypts specifically permit lower sperm production by the males. In the sperm head of these two moles, the acrosome displays the long rostrum that is typical of other Insectivora, and the perforatorium has the barbs by which soricid spermatozoa probably bind to the zona pellucida. Perhaps allied to this, immunoblots indicated that the immunoreactive acrosomal matrix of Scalopus spermatozoa is simpler than the polypeptide complex of the bovine and hamster acrosomal matrix.

  12. The Origin of the Mole Concept

    Science.gov (United States)

    Jensen, William B.

    2004-01-01

    German Chemist, August Wilhelm Hofmann first introduced the term "molar" (from the Latin moles, meaning "a large mass") into chemistry, around 1865. The particular use of the term molar gained currency in the physics literature, where it was in common use at least through the 1940s.

  13. CT diagnosis of invasive hydatidiform mole

    International Nuclear Information System (INIS)

    Lu Mingquan; Jiang Lina; Li Xianxing; Wang Peijun

    2000-01-01

    Objective: To investigate the CT features and the diagnostic value in invasive mole. Methods: Eleven cases (age, 30 to 53 years, mean 40 years) with invasive mole proved by operation and pathology were studied, including 3 cases during peri-menopausal period of eight months, ten months and twelve months respectively. All cases were scanned by CT and enhanced study was done. Results: All cases showed enlargement of uterus of varying degrees. On CT, the density of uterine cavity was similar to that of water, intermingled with spotty patchy and hazy circular isodense shadows. High density stripe-like bleeding foci were found in 3 cases. The outline of uterine cavity was locally disrupted in all case and the muscle layer was thickened in 3 cases. On enhanced CT scan, the lesions in the uterine cavity appeared markedly hyperdense, just like 'the crater' and the 'mole sign'. The muscle layers at the site of disruption showed inhomogeneous enhancement after contrast injection. Conclusion: The CT features of invasive mole are characteristic, with important diagnostic value, especially for those during peri-menopausal period

  14. Experimental study of arsenic speciation in vapor phase to 500°C: Implications for As transport and fractionation in low-density crustal fluids and volcanic gases.

    OpenAIRE

    Pokrovski , Gleb S.; Zakirov , Ildar V.; Roux , Jacques; Testemale , Denis; Hazemann , Jean-Louis; Y. U. Bychkov , Andrew; V. Golikova , Galina

    2002-01-01

    The stoichiometry and stability of arsenic gaseous complexes were determined in the system As-H2O ± NaCl ± HCl ± H2S at temperatures up to 500°C and pressures up to 600 bar, from both measurements of As(III) and As(V) vapor-liquid and vapor-solid partitioning, and X-ray absorption fine structure (XAFS) spectroscopic study of As(III)-bearing aqueous fluids. Vapor-aqueous solution partitioning for As(III) was measured from 250 to 450°C at the saturated vapor pressure of the system (Psat) with a...

  15. Social structure predicts genital morphology in African mole-rats.

    Directory of Open Access Journals (Sweden)

    Marianne L Seney

    2009-10-01

    Full Text Available African mole-rats (Bathyergidae, Rodentia exhibit a wide range of social structures, from solitary to eusocial. We previously found a lack of sex differences in the external genitalia and morphology of the perineal muscles associated with the phallus in the eusocial naked mole-rat. This was quite surprising, as the external genitalia and perineal muscles are sexually dimorphic in all other mammals examined. We hypothesized that the lack of sex differences in naked mole-rats might be related to their unusual social structure.We compared the genitalia and perineal muscles in three African mole-rat species: the naked mole-rat, the solitary silvery mole-rat, and the Damaraland mole-rat, a species considered to be eusocial, but with less reproductive skew than naked mole-rats. Our findings support a relationship between social structure, mating system, and sexual differentiation. Naked mole-rats lack sex differences in genitalia and perineal morphology, silvery mole-rats exhibit sex differences, and Damaraland mole-rats are intermediate.The lack of sex differences in naked mole-rats is not an attribute of all African mole-rats, but appears to have evolved in relation to their unusual social structure and reproductive biology.

  16. Social structure predicts genital morphology in African mole-rats.

    Science.gov (United States)

    Seney, Marianne L; Kelly, Diane A; Goldman, Bruce D; Sumbera, Radim; Forger, Nancy G

    2009-10-15

    African mole-rats (Bathyergidae, Rodentia) exhibit a wide range of social structures, from solitary to eusocial. We previously found a lack of sex differences in the external genitalia and morphology of the perineal muscles associated with the phallus in the eusocial naked mole-rat. This was quite surprising, as the external genitalia and perineal muscles are sexually dimorphic in all other mammals examined. We hypothesized that the lack of sex differences in naked mole-rats might be related to their unusual social structure. We compared the genitalia and perineal muscles in three African mole-rat species: the naked mole-rat, the solitary silvery mole-rat, and the Damaraland mole-rat, a species considered to be eusocial, but with less reproductive skew than naked mole-rats. Our findings support a relationship between social structure, mating system, and sexual differentiation. Naked mole-rats lack sex differences in genitalia and perineal morphology, silvery mole-rats exhibit sex differences, and Damaraland mole-rats are intermediate. The lack of sex differences in naked mole-rats is not an attribute of all African mole-rats, but appears to have evolved in relation to their unusual social structure and reproductive biology.

  17. Definition of the mole (IUPAC Recommendation 2017)

    OpenAIRE

    Marquardt, Roberto; Meija, Juris; Mester, Zoltán; Towns, Marcy; Weir, Ron; Davis, Richard; Stohner, Jürgen

    2018-01-01

    In 2011 the General Conference on Weights and Measures (CGPM) noted the intention of the International Committee for Weights and Measures (CIPM) to revise the entire International System of Units (SI) by linking all seven base units to seven fundamental physical constants. Of particular interest to chemists, new definitions for the kilogram and the mole have been proposed. A recent IUPAC Technical Report discussed these new definitions in relation to immediate consequences for the chemical co...

  18. Prevalence of Toxoplasma gondii in common moles (Talpa europaea)

    NARCIS (Netherlands)

    Krijger, I.M.; Cornelissen, J.B.W.J.; Wisselink, H.J.; Meerburg, B.G.

    2014-01-01

    Background The prevalence of Toxoplasma gondii in common moles, Talpa europaea, was investigated in order to determine whether moles can serve as an indicator species for T. gondii infections in livestock. Findings In total, 86 moles were caught from 25 different sites in the Netherlands. Five

  19. Horizontal Variability of Water and Its Relationship to Cloud Fraction near the Tropical Tropopause: Using Aircraft Observations of Water Vapor to Improve the Representation of Grid-scale Cloud Formation in GEOS-5

    Science.gov (United States)

    Selkirk, Henry B.; Molod, Andrea M.

    2014-01-01

    Large-scale models such as GEOS-5 typically calculate grid-scale fractional cloudiness through a PDF parameterization of the sub-gridscale distribution of specific humidity. The GEOS-5 moisture routine uses a simple rectangular PDF varying in height that follows a tanh profile. While below 10 km this profile is informed by moisture information from the AIRS instrument, there is relatively little empirical basis for the profile above that level. ATTREX provides an opportunity to refine the profile using estimates of the horizontal variability of measurements of water vapor, total water and ice particles from the Global Hawk aircraft at or near the tropopause. These measurements will be compared with estimates of large-scale cloud fraction from CALIPSO and lidar retrievals from the CPL on the aircraft. We will use the variability measurements to perform studies of the sensitivity of the GEOS-5 cloud-fraction to various modifications to the PDF shape and to its vertical profile.

  20. Measurement and modeling of high-pressure (vapor + liquid) equilibria of (CO2 + alkanol) binary systems

    International Nuclear Information System (INIS)

    Bejarano, Arturo; Gutierrez, Jorge E.; Araus, Karina A.; Fuente, Juan C. de la

    2011-01-01

    Research highlights: → (Vapor + liquid) equilibria of three (CO 2 + C 5 alcohol) binary systems were measured. → Complementary data are reported at (313, 323 and 333) K and from (2 to 11) MPa. → No liquid immiscibility was observed at the temperatures and pressures studied. → Experimental data were correlated with the PR-EoS and the van de Waals mixing rules. → Correlation results showed relative deviations ≤8 % (liquid) and ≤2 % (vapor). - Abstract: Complementary isothermal (vapor + liquid) equilibria data are reported for the (CO 2 + 3-methyl-2-butanol), (CO 2 + 2-pentanol), and (CO 2 + 3-pentanol) binary systems at temperatures of (313, 323, and 333) K, and at pressure range of (2 to 11) MPa. For all (CO 2 + alcohol) systems, it was visually monitored that there was no liquid immiscibility at the temperatures and pressures studied. The experimental data were correlated with the Peng-Robinson equation of state using the quadratic mixing rules of van der Waals with two adjustable parameters. The calculated (vapor + liquid) equilibria compositions were found to be in good agreement with the experimental data with deviations for the mole fractions <8% and <2% for the liquid and vapor phase, respectively.

  1. Ultrasonographic findings of hydatidiform mole and missed abortion

    International Nuclear Information System (INIS)

    Yun, Kwang Myeong; Lee, Yeong Hwan; Chung, Hye Kyeong; Chung, Duck Soo; Kim, Ok Dong

    1990-01-01

    To establish the sonographic characteristics of the hydatidiform mole and the missed abortion with placental degeneration, we have retrospectively analyzed 12 cases of complete mole, 10 cases of partial mole, and 10 cases of missed abortion with placental hydropic degeneration, collected at Taegu Catholic General Hospital, from January 1986 to December 1989. The results were as follows : 1. Of 12 cases of complete mole, all demonstrated diffuse intrauterine vesicular pattern of internal echo without a gestational sac. Two cases were recurred after D and E. 2. The partial mole was characterized by focal (70%) or diffuse (20%) distribution of hydatidiform placental change and a gestational sac (100%) with or without a macerated fetus. But the striking hydatidiform placental change was not present in one cases of partial mole. 3. The uterus was larger for dates in 9 cases (90%) of complete mole, but smaller for dates in 7 cases (70%) of partial mole. 4. The missed abortion with placental hydropic degeneration was indistinguished from a partial mole due to their similar sonographic appearance : focal or diffuse cystic change of a placenta, a distorted gestational sac with or without a fetus, and a smaller uterus for dates. On conclusion, the complete mole could be easily distinguished from a partial mole or a missed abortion by sonography : a gestational sac or an area of noncystic placenta was not identified in a complete mole. The partial mole was indistinguished from a missed abortion, but if there is the suspicion of trophoblastic proliferation, such as a convex placental surface or a larger uterus for dates, then the diagnosis is probably a partial mole rather than a missed abortion

  2. Instrumented Moles for Planetary Subsurface Regolith Studies

    Science.gov (United States)

    Richter, L. O.; Coste, P. A.; Grzesik, A.; Knollenberg, J.; Magnani, P.; Nadalini, R.; Re, E.; Romstedt, J.; Sohl, F.; Spohn, T.

    2006-12-01

    Soil-like materials, or regolith, on solar system objects provide a record of physical and/or chemical weathering processes on the object in question and as such possess significant scientific relevance for study by landed planetary missions. In the case of Mars, a complex interplay has been at work between impact gardening, aeolian as well as possibly fluvial processes. This resulted in regolith that is texturally as well as compositionally layered as hinted at by results from the Mars Exploration Rover (MER) missions which are capable of accessing shallow subsurface soils by wheel trenching. Significant subsurface soil access on Mars, i.e. to depths of a meter or more, remains to be accomplished on future missions. This has been one of the objectives of the unsuccessful Beagle 2 landed element of the ESA Mars Express mission having been equipped with the Planetary Underground Tool (PLUTO) subsurface soil sampling Mole system capable of self-penetration into regolith due to an internal electro-mechanical hammering mechanism. This lightweight device of less than 900 g mass was designed to repeatedly obtain and deliver to the lander regolith samples from depths down to 2 m which would have been analysed for organic matter and, specifically, organic carbon from potential extinct microbial activity. With funding from the ESA technology programme, an evolved Mole system - the Instrumented Mole System (IMS) - has now been developed to a readiness level of TRL 6. The IMS is to serve as a carrier for in situ instruments for measurements in planetary subsurface soils. This could complement or even eliminate the need to recover samples to the surface. The Engineering Model hardware having been developed within this effort is designed for accommodating a geophysical instrument package (Heat Flow and Physical Properties Package, HP3) that would be capable of measuring regolith physical properties and planetary heat flow. The chosen design encompasses a two-body Mole

  3. An NPT Monte Carlo Molecular Simulation-Based Approach to Investigate Solid-Vapor Equilibrium: Application to Elemental Sulfur-H2S System

    KAUST Repository

    Kadoura, Ahmad Salim

    2013-06-01

    In this work, a method to estimate solid elemental sulfur solubility in pure and gas mixtures using Monte Carlo (MC) molecular simulation is proposed. This method is based on Isobaric-Isothermal (NPT) ensemble and the Widom insertion technique for the gas phase and a continuum model for the solid phase. This method avoids the difficulty of having to deal with high rejection rates that are usually encountered when simulating using Gibbs ensemble. The application of this method is tested with a system made of pure hydrogen sulfide gas (H2S) and solid elemental sulfur. However, this technique may be used for other solid-vapor systems provided the fugacity of the solid phase is known (e.g., through experimental work). Given solid fugacity at the desired pressure and temperature, the mole fraction of the solid dissolved in gas that would be in chemical equilibrium with the solid phase might be obtained. In other words a set of MC molecular simulation experiments is conducted on a single box given the pressure and temperature and for different mole fractions of the solute. The fugacity of the gas mixture is determined using the Widom insertion method and is compared with that predetermined for the solid phase until one finds the mole fraction which achieves the required fugacity. In this work, several examples of MC have been conducted and compared with experimental data. The Lennard-Jones parameters related to the sulfur molecule model (ɛ, σ) have been optimized to achieve better match with the experimental work.

  4. MOLES3: Implementing an ISO standards driven data catalogue

    Directory of Open Access Journals (Sweden)

    Graham A Parton

    2015-02-01

    Full Text Available ISO19156 Observations and Measurements (O&M provides a standardised framework for organising information about the collection of information about the environment.  Here we describe the implementation of a specialisation of O&M for environmental data, the Metadata Objects for Linking Environmental Sciences (MOLES3.MOLES3 provides support for organising information about data, and for user navigation around data holdings. The implementation described here, “CEDA-MOLES”, also supports data management functions for the Centre for Environmental Data Archival, CEDA. The previous iteration of MOLES (MOLES2 saw active use over five years, being replaced by CEDA-MOLES in late 2014. During that period important lessons were learnt both about the information needed, as well as how to design and maintain the necessary information systems. In this paper we review the problems encountered in MOLES2; how and why CEDA-MOLES was developed and engineered; the migration of information holdings from MOLES2 to CEDA-MOLES; and, finally, provide an early assessment of MOLES3 (as implemented in CEDA-MOLES and its limitations.Key drivers for the MOLES3 development included the necessity for improved data provenance, for further structured information to support ISO19115 discovery metadata  export (for EU INSPIRE compliance, and to provide appropriate fixed landing pages for Digital Object Identifiers (DOIs in the presence of evolving datasets. Key lessons learned included the importance of minimising information structure in free text fields, and the necessity to support as much agility in the information infrastructure as possible without compromising on maintainability both by those using the systems internally and externally (e.g. citing in to the information infrastructure, and those responsible for the systems themselves. The migration itself needed to ensure continuity of service and traceability of archived assets.

  5. Metrics of a 'mole hole' against the Lobachevsky space background

    International Nuclear Information System (INIS)

    Tentyukov, M.N.

    1994-01-01

    'Classical' mole hole are the Euclidean metrics consisting of two large space regions connected by a throat. They are the instanton solutions of the Einstein equations. It is shown that for existence of mole holes in the general relativity theory it is required the energy-momentum tensor breaking energetic conditions. 9 refs., 7 figs

  6. Hydatidiform mole in Aminu Kano teaching hospital, northwestern ...

    African Journals Online (AJOL)

    Background: Hydatidiform mole is a benign tumour of the trophoblast tissue and a relatively common gynaecological emergency. It could resolve spontaneously following evacuation, however 9-20% of patients with complete hydatidiform mole go on to have gestational trophoblast neoplasia. It is potentially curable once the ...

  7. Measurement and modeling of high-pressure (vapor + liquid) equilibria of (CO{sub 2} + alkanol) binary systems

    Energy Technology Data Exchange (ETDEWEB)

    Bejarano, Arturo; Gutierrez, Jorge E. [Departamento de Ingenieria Quimica y Ambiental, Universidad Tecnica Federico Santa Maria, Avda. Espana 1680, Valparaiso (Chile); Araus, Karina A. [Departamento de Ingenieria Quimica y Bioprocesos, Pontificia Universidad Catolica de Chile, Avda. Vicuna Mackenna 4860, Macul, Santiago (Chile); Fuente, Juan C. de la, E-mail: juan.delafuente@usm.c [Departamento de Ingenieria Quimica y Ambiental, Universidad Tecnica Federico Santa Maria, Avda. Espana 1680, Valparaiso (Chile); Centro Regional de Estudios en Alimentos Saludables, Blanco 1623, Valparaiso (Chile)

    2011-05-15

    Research highlights: (Vapor + liquid) equilibria of three (CO{sub 2} + C{sub 5} alcohol) binary systems were measured. Complementary data are reported at (313, 323 and 333) K and from (2 to 11) MPa. No liquid immiscibility was observed at the temperatures and pressures studied. Experimental data were correlated with the PR-EoS and the van de Waals mixing rules. Correlation results showed relative deviations {<=}8 % (liquid) and {<=}2 % (vapor). - Abstract: Complementary isothermal (vapor + liquid) equilibria data are reported for the (CO{sub 2} + 3-methyl-2-butanol), (CO{sub 2} + 2-pentanol), and (CO{sub 2} + 3-pentanol) binary systems at temperatures of (313, 323, and 333) K, and at pressure range of (2 to 11) MPa. For all (CO{sub 2} + alcohol) systems, it was visually monitored that there was no liquid immiscibility at the temperatures and pressures studied. The experimental data were correlated with the Peng-Robinson equation of state using the quadratic mixing rules of van der Waals with two adjustable parameters. The calculated (vapor + liquid) equilibria compositions were found to be in good agreement with the experimental data with deviations for the mole fractions <8% and <2% for the liquid and vapor phase, respectively.

  8. Moles: Tool-Assisted Environment Isolation with Closures

    Science.gov (United States)

    de Halleux, Jonathan; Tillmann, Nikolai

    Isolating test cases from environment dependencies is often desirable, as it increases test reliability and reduces test execution time. However, code that calls non-virtual methods or consumes sealed classes is often impossible to test in isolation. Moles is a new lightweight framework which addresses this problem. For any .NET method, Moles allows test-code to provide alternative implementations, given as .NET delegates, for which C# provides very concise syntax while capturing local variables in a closure object. Using code instrumentation, the Moles framework will redirect calls to provided delegates instead of the original methods. The Moles framework is designed to work together with the dynamic symbolic execution tool Pex to enable automated test generation. In a case study, testing code programmed against the Microsoft SharePoint Foundation API, we achieved full code coverage while running tests in isolation without an actual SharePoint server. The Moles framework integrates with .NET and Visual Studio.

  9. Hydatidiform mole resulting from sexual violence

    Directory of Open Access Journals (Sweden)

    Drezett Jefferson

    2012-02-01

    Full Text Available Abstract Background Hydatidiform mole (HM is characterized by abnormal proliferation of human trophoblast with producers functioning tissues of human chorionic gonadotropin. It can evolve with ovarian cysts tecaluteínicos, hypertension of pregnancy or hyperthyroidism. The incidence of HM is variable and its etiology poorly known, associated with nutritional factors, environmental, age, parity, history of HM, oral contraceptives, smoking, consanguinity or defects in germ cells. There is no reference in literature on HM resulting from sexual violence, objective of this report. Method Description of two cases of HM among 1146 patients with pregnancy resulting from sexual violence treated at Hospital Pérola Byington, São Paulo, from July 1994 to August 2011. Results The cases affected young, white, unmarried, low educated and low parity women. Sexual violence was perpetrated by known offenders unrelated to the victims, under death threat. Ultrasound and CT of the pelvis showed bulky uterus compatible with HM without myometrial invasion. One case was associated with theca lutein cysts. The two cases were diagnosed in the second trimester of pregnancy and evolved with hyperthyroidism. There was no hypertension, disease recurrence, metastasis or sexually transmitted infection. Conclusion The incidence of HM was 1:573 pregnancies resulting from rape, within the range estimated for Latin American countries. Trophoblastic material can be preserved to identify the violence perpetrator, considering only the paternal HM chromosomes. History of sexual violence should be investigated in cases of HM in the first half of adolescence and women in a vulnerable condition.

  10. Microscopic study of edema in hydatidiform mole

    Directory of Open Access Journals (Sweden)

    Olivar C. Castejón

    2014-09-01

    Full Text Available Objectives: the purpose of this study is to use light microscopy and scanning electron microscopy to determine the effect of edema on the structure of the molar vesicle. Methods: samples were taken from the complete hydatidiform mole and processed using conventional light and scanning electron microscopy techniques and an observation protocol that identified four variables: factors underlying the development of edema; the condition of the trophoblast basement membrane, development of the villi, accumulation and degeneration of sulphated mucosubstances at stromal level. Results: light microscopy showed a permeable trophoblastic basement membrane, a swollen syncytium, edematous regions disorganizating the stromal region and causing ischemic necrosis of cells. Using scanning electron microscopy, the basement membrane was found to be distended and thickened, with large irregular holes for the entry and movement of liquid, leaving a wide range of fluids during the influx process and depriving stromal cells of nutrition. Conclusions: a new three-dimensional view of the changes brought about by the entry of fluids into the stroma of molar hydropic vesicles was provided by scanning electron microscopy and confirmed by light microscopy, thereby explaining the changes occurring at the level of the stroma as an effect of the edema.

  11. Melting temperature, vapor density, and vapor pressure of molybdenum pentafluoride

    Energy Technology Data Exchange (ETDEWEB)

    Krause, Jr, R F; Douglas, T B [National Bureau of Standards, Washington, D.C. (USA). Inst. for Materials Research

    1977-12-01

    A sample of MoF/sub 5/ was prepared by reaction of MoF/sub 6/(g) and Mo(c). Melting curves of temperature against time established the melting temperature at zero impurity to be 318.85 K, the enthalpy of fusion to be 6.1 kJ mol/sup -1/ (+ - 5 per cent), and the cryoscopic impurity of the sample to be 0.15 mole per cent. In the presence of MoF/sub 6/(g) which was added to suppress disproportionation, the vapor density of MoF/sub 5/ over the liquid was measured by the transpiration method at 343, 363, and 383 K, the total MoF/sub 5/ that evaporated being determined by permanganate titration. The total vapor pressure of MoF/sub 5/ oligomers over the liquid was measured by a simple static method at 373 and 392 K, while melting temperatures were taken alternately to monitor possible contamination of the sample. Although the vapor pressures were adjusted for disproportionation, solution of MoF/sub 6/ in MoF/sub 5/ (1), and wall adsorption of MoF/sub 6/ their percentage uncertainty is probably several times that of the vapor densities. A combination of the two properties indicates the average extent of association of the saturated vapor to be near 2, which is the value for the dimer species (MoF/sub 5/)/sub 2/.

  12. Genome Stability Maintenance in Naked Mole-Rat.

    Science.gov (United States)

    Petruseva, I O; Evdokimov, A N; Lavrik, O I

    2017-01-01

    The naked mole-rat ( Heterocephalus glaber ) is one of the most promising models used to study genome maintenance systems, including the effective repair of damage to DNA. The naked mole-rat is the longest lived rodent species, which is extraordinarily resistant to cancer and has a number of other unique phenotypic traits. For at least 80% of its lifespan, this animal shows no signs of aging or any increased likelihood of death and retains the ability to reproduce. The naked mole-rat draws the heightened attention of researchers who study the molecular basis of lengthy lifespan and cancer resistance. Despite the fact that the naked mole-rat lives under genotoxic stress conditions (oxidative, etc.), the main characteristics of its genome and proteome are a high stability and effective functioning. Replicative senescence in the somatic cells of naked mole-rats is missing, while an additional p53/pRb-dependent mechanism of early contact inhibition has been revealed in its fibroblasts, which controls cell proliferation and its mechanism of arf- dependent aging. The unique traits of phenotypic and molecular adaptations found in the naked mole-rat speak to a high stability and effective functioning of the molecular machinery that counteract damage accumulation in its genome. This review analyzes existing results in the study of the molecular basis of longevity and high cancer resistance in naked mole-rats.

  13. MOLED: Simulation of multilayer organic light emitting diodes

    Science.gov (United States)

    Houili, H.; Tutiš, E.; Lütjens, H.; Bussac, M. N.; Zuppiroli, L.

    2003-12-01

    MOLED solves the dynamics of electrons and holes in multilayer Organic Light Emitting Diodes (OLED). The carriers are injected on the positive and negative electrodes of the device by tunneling through a potential barrier. Thermal excitation processes across the barrier are also included. In the interior of the device the electron-hole recombination occurs when the two carriers are close enough, according to a model inspired from the one of Langevin. A fraction of these recombined pairs gives photons. The charge transport inside the organic material occurs through hopping. Several choices of mobility formulae are available in the code. MOLED can be used for OLEDs with an arbitrary number of layers. The output consists of numerous fields that describe the device performance. For example, there are the current, the recombination and the charge density distributions, the electric field distribution, the current-voltage characteristics and the device internal quantum efficiency. Program summaryTitle of program: MOLED Catalogue identifier: ADSG Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADSG Program obtainable from: CPC Program Library, Queen's University of Belfast, N. Ireland Operating systems under which the program has been tested: Unix, Linux Programming language used: FORTRAN 90 Memory required to execute with typical data: 2 MB No. of bytes in distributed program: 26 942 No. of bits in a word: 64 Peripherals used: permanent disk storage No. of lines in distributed program, including test data, etc.: 3695 Distribution format: tar gzip file Nature of the physical problem: Injection of electrons and holes into an organic electroluminescent material occurs through tunneling from metal electrodes. The transport of carriers inside the molecular medium proceeds by hopping from one molecule to another. The emission of light is a result of their radiative Langevin recombination (for a review see [Scott et al., Synthetic Metals 111-112 (2000) 289; Friend et al

  14. Aluminum Gallium Nitride Alloys Grown via Metalorganic Vapor-Phase Epitaxy Using a Digital Growth Technique

    Science.gov (United States)

    Rodak, L. E.; Korakakis, D.

    2011-04-01

    This work investigates the use of a digital growth technique as a viable method for achieving high-quality aluminum gallium nitride (Al x Ga1- x N) films via metalorganic vapor-phase epitaxy. Digital alloys are superlattice structures with period thicknesses of a few monolayers. Alloys with an AlN mole fraction ranging from 0.1 to 0.9 were grown by adjusting the thickness of the AlN layer in the superlattice. High-resolution x-ray diffraction was used to determine the superlattice period and c-lattice parameter of the structure, while reciprocal-space mapping was used to determine the a-lattice parameter and evaluate growth coherency. A comparison of the measured lattice parameter with both the nominal value and also the underlying buffer layer is discussed.

  15. ACTIVITY PATTERNS IN THE MOLE-RATS TACHYORYCTES ...

    African Journals Online (AJOL)

    Heilophoblus spends over 50 % of the day out of its nest, Tachyoryctes, ..... Surface foraging through an open hole and mole-hill formation could be directly ..... Heliophobius fed at irregular intervals throughout the day and night (Jarvis, ...

  16. Amount of substance and the proposed redefinition of the mole

    Science.gov (United States)

    Milton, M. J. T.; Mills, I. M.

    2009-06-01

    There has been considerable discussion about the merits of redefining four of the base units of the SI, including the mole. In this paper, the options for implementing a new definition for the mole based on a fixed value for the Avogadro constant are discussed. They are placed in the context of the macroscopic nature of the quantity amount of substance and the opportunity to introduce a system for molar and atomic masses with unchanged values and consistent relative uncertainties.

  17. Diagnosis of hydatidiform mole by hysterography through transabdominal injection

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Chung Kyu; Park, Chang Yun; Choi, Byung Sook [Yonsei University College of Medicine, Seoul (Korea, Republic of)

    1972-03-15

    Molar pregnancy presents a pathologic condition requiring surgery of the uterus promptly as possible although hydatidiform mole itself is a benign disease. In order to remove the mole as quickly as possible, early diagnosis is desirable. In actual practice, however, definite preoperative diagnosis by clinical manifestation is impossible since which is vague or altogether absent symptoms especially in first trimester. Hysterography by transabdominal injection is very valuable and easy procedure for accurate diagnosis of hydatidiform mole which shows typical honey combed, moth eaten or sponge pattern on roentgenography. We have experienced 68 cases of hydatidiform mole during last five and half years. Among them hysterography by transabdominal route was done on 26 cases and shows 96% diagnostic accuracy. One missed case was turned out to be missed abortion. The absence of accidents indicates the harmlessness of the method. We feel the best approach in making diagnosis of hydatidiform mole among clinically borderline and in conclusive for mole pregnancy and its differential diagnosis is by use of transabdominal hysterography.

  18. Diagnosis of hydatidiform mole by hysterography through transabdominal injection

    International Nuclear Information System (INIS)

    Kim, Chung Kyu; Park, Chang Yun; Choi, Byung Sook

    1972-01-01

    Molar pregnancy presents a pathologic condition requiring surgery of the uterus promptly as possible although hydatidiform mole itself is a benign disease. In order to remove the mole as quickly as possible, early diagnosis is desirable. In actual practice, however, definite preoperative diagnosis by clinical manifestation is impossible since which is vague or altogether absent symptoms especially in first trimester. Hysterography by transabdominal injection is very valuable and easy procedure for accurate diagnosis of hydatidiform mole which shows typical honey combed, moth eaten or sponge pattern on roentgenography. We have experienced 68 cases of hydatidiform mole during last five and half years. Among them hysterography by transabdominal route was done on 26 cases and shows 96% diagnostic accuracy. One missed case was turned out to be missed abortion. The absence of accidents indicates the harmlessness of the method. We feel the best approach in making diagnosis of hydatidiform mole among clinically borderline and in conclusive for mole pregnancy and its differential diagnosis is by use of transabdominal hysterography

  19. Experimental measurement of vapor pressures and (vapor + liquid) equilibrium for {1,1,1,2-tetrafluoroethane (R134a) + propane (R290)} by a recirculation apparatus with view windows

    International Nuclear Information System (INIS)

    Dong Xueqiang; Gong Maoqiong; Liu Junsheng; Wu Jianfeng

    2011-01-01

    The saturated vapor pressures of 1,1,1,2-tetrafluoroethane (R134a) and propane (R290), and the (vapor + liquid) equilibrium (VLE) data at (255.000, 265.000, 275.000, and 285.000) K for the (R134a + R290) system were measured by a recirculation apparatus with view windows. The uncertainty of the temperatures, pressures, and compositions are less than ±5 mK, ±0.0005 MPa, and ±0.005, respectively. The saturated vapor pressures data were correlated by a Wagner type equation and compared with the reference data. The binary VLE data were correlated with the Peng-Robinson equation of state (PR EoS) incorporating the Huron-Vidal (HV) mixing rule utilizing the nonrandom two-liquid (NRTL) activity coefficient model. For mixtures, the maximum average absolute relative deviation of pressure is 0.15%, while the maximum average absolute deviation of vapor phase mole fraction is 0.0045. Azeotropic behavior can be found for the (R134a + R290) system at measured temperatures.

  20. Experimental measurement of vapor pressures and (vapor + liquid) equilibrium for {l_brace}1,1,1,2-tetrafluoroethane (R134a) + propane (R290){r_brace} by a recirculation apparatus with view windows

    Energy Technology Data Exchange (ETDEWEB)

    Dong Xueqiang [Key Laboratory of Cryogenics, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, P.O. Box 2711, Beijing 100190 (China); Graduate University of Chinese Academy of Sciences, Beijing 100039 (China); Gong Maoqiong, E-mail: gongmq@mail.ipc.ac.c [Key Laboratory of Cryogenics, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, P.O. Box 2711, Beijing 100190 (China); Liu Junsheng [Key Laboratory of Cryogenics, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, P.O. Box 2711, Beijing 100190 (China); Graduate University of Chinese Academy of Sciences, Beijing 100039 (China); Wu Jianfeng, E-mail: jfwu@mail.ipc.ac.c [Key Laboratory of Cryogenics, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, P.O. Box 2711, Beijing 100190 (China)

    2011-03-15

    The saturated vapor pressures of 1,1,1,2-tetrafluoroethane (R134a) and propane (R290), and the (vapor + liquid) equilibrium (VLE) data at (255.000, 265.000, 275.000, and 285.000) K for the (R134a + R290) system were measured by a recirculation apparatus with view windows. The uncertainty of the temperatures, pressures, and compositions are less than {+-}5 mK, {+-}0.0005 MPa, and {+-}0.005, respectively. The saturated vapor pressures data were correlated by a Wagner type equation and compared with the reference data. The binary VLE data were correlated with the Peng-Robinson equation of state (PR EoS) incorporating the Huron-Vidal (HV) mixing rule utilizing the nonrandom two-liquid (NRTL) activity coefficient model. For mixtures, the maximum average absolute relative deviation of pressure is 0.15%, while the maximum average absolute deviation of vapor phase mole fraction is 0.0045. Azeotropic behavior can be found for the (R134a + R290) system at measured temperatures.

  1. Analysis of internal doses to Mole voles inhabiting the East-Ural radioactive trace

    Energy Technology Data Exchange (ETDEWEB)

    Malinovsky, G.; Yarmoshenko, I. [Institute of Industrial Ecology UB RAS (Russian Federation); Chibiryak, M.; Vasil' ev, A. [Institute of Plant and Animal Ecology UB RAS (Russian Federation)

    2014-07-01

    absorbed fractions of beta-radiation energy for different combinations of source and target organs calculated using voxel-based mouse model (e.g. Stabin et. al., 2006). Distribution of radionuclide by organs and tissues was estimated applying developed strontium biokinetic model for mouse-like rodent. Similar approach can be used to calculate radiation doses to organs and tissues of mole voles, taking into account differences in size and body weight of mice and mole voles. Strontium biokinetic model for mole vole can be designed basing on that of mouse-like rodent, considering physiological differences and available published data on strontium retention in the organism of burrowing rodents. There are no specific voxel-based models of mole vole. Nevertheless, the models of small mammals of similar size can be applied. Assessment of individual doses to mole voles allows investigating the relationship between radiation dose to these animals and observed morphometric and other biological effects. Document available in abstract form only. The research has been made under support of Ural Branch of Russian Academy of Sciences, project 12-M-24-2016. (authors)

  2. Ultrasonographic findings of Myoma, H-mole and Missed abortion

    International Nuclear Information System (INIS)

    Huh, Nam Yoon; You, H. S.; Seong, K. J.; Park, C. Y.

    1982-01-01

    Ultrasonography is very important in the diagnosis of various kinds of diseases in Obsterics and Gynecology. It has high diagnostic accuracy in the diagnosis of pelvic masses and widely used for the detection of normal orpathologic pregnancy. But still it is difficult to differentiate degenerated myoma, H-mole and missed abortion by ultrasonography. So the authors analyzed the ultrasonographic findings of 81 patients with myoma(29 cases), H-mole(23 cases), and missed abortion(29 cases) and the results are as follows; 1. Diagnostic accuracy was 8.6% in myoma, 87% in H-mole and 89% in missed abortion. 2. The most typical ultrasonographic finding of myoma was obulated mass contour with nonhomogenous internal echo. 3. The most characteristic finding of H-mole was fine vesicular pattern internal echo with globular enlargement of uterus. 4. The most frequent finding of missed abortion was deformed gestational sac with or without remained fetal echo. 5. Clinical correlation was very important for accurate diagnosis, especially when differential diagnosis was very difficult between myoma with marked cystic degeneration, missed abortion with large distorted gestational sac and H-mole with severe degeneration

  3. Electron absorbed fractions in skeletal soft tissues based on red bone marrow segmentation at runtime in muCT images of human trabecular bone;Fracoes absorvidas de eletrons em tecidos moles do esqueleto avaliadas com base na segmentacao em tempo de execucao da medula ossea vermelha contida em imagens muCT do osso trabecular humano

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, J.W. [Instituto Federal de Educacao, Ciencia e Tecnologia de Pernambuco, Recife, PE (Brazil); Kramer, R. [Universidade de Pernambuco (UPE), Recife, PE (Brazil). Escola Politecnica; Khoury, H.J. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear; Robson-Brown, K. [University of Bristol, Bristol (United Kingdom). Dept. of Archaeology and Anthropology

    2009-07-01

    Skeletal dosimetry determines equivalent dose or absorbed fractions in the red bone marrow (RBM) and the osteogenic cells on bone surfaces (BSC). Following a method used earlier for the BSC, RBM and yellow bone marrow (YBM) have been segmented in the marrow cavities of muCT images of human spongiosa at runtime, i.e. during the execution of the Monte Carlo calculation, which avoids the necessity to segment RBM and YBM externally in muCT images for many different cellularities and to store the data. Using this internal RBM/YBM segmentation, this study presents electron absorbed fractions for the RBM and the BSC as a function of the voxel resolution and also compares the results with data from other investigations. (author)

  4. A cytosolic protein factor from the naked mole-rat activates proteasomes of other species and protects these from inhibition

    Science.gov (United States)

    Rodriguez, Karl A.; Osmulski, Pawel A.; Pierce, Anson; Weintraub, Susan T.; Gaczynska, Maria; Buffenstein, Rochelle

    2015-01-01

    The naked mole-rat maintains robust proteostasis and high levels of proteasome-mediated proteolysis for most of its exceptional (~31y) life span. Here, we report that the highly active proteasome from the naked mole-rat liver resists attenuation by a diverse suite of proteasome-specific small molecule inhibitors. Moreover, mouse, human, and yeast proteasomes exposed to the proteasome-depleted, naked mole-rat cytosolic fractions, recapitulate the observed inhibition resistance, and mammalian proteasomes also show increased activity. Gel filtration coupled with mass spectrometry and atomic force microscopy indicates that these traits are supported by a protein factor that resides in the cytosol. This factor interacts with the proteasome and modulates its activity. Although HSP72 and HSP40 (Hdj1) are among the constituents of this factor, the observed phenomenon, such as increasing peptidase activity and protecting against inhibition cannot be reconciled with any known chaperone functions. This novel function may contribute to the exceptional protein homeostasis in the naked mole-rat and allow it to successfully defy aging. PMID:25018089

  5. Extreme hypoxia tolerance of naked mole-rat brain.

    Science.gov (United States)

    Larson, John; Park, Thomas J

    2009-12-09

    Mammalian brains have extremely high levels of aerobic metabolism and typically suffer irreversible damage after brief periods of oxygen deprivation such as occur during stroke or cardiac arrest. Here we report that brain tissue from naked mole-rats, rodents that live in a chronically low-oxygen environment, is remarkably resistant to hypoxia: naked mole-rat neurons maintain synaptic transmission much longer than mouse neurons and can recover from periods of anoxia exceeding 30 min. We suggest that brain tolerance to hypoxia may result from slowed or arrested brain development in these extremely long-lived animals.

  6. Hydatidiform moles among patients with incomplete abortion in ...

    African Journals Online (AJOL)

    SHS

    ated risk factors of HM among patients with incomplete abortion evacuated at Bugando Medical ... Konje E, Massinde A, Rambau P. Hydatidiform moles among patients with ... countries (North America, Australia, New Zealand and ... missed as the cause of abortion. .... and duration of cigarette smoking could not be elicited.

  7. Ground sounds: Seismic detection in the golden mole

    Science.gov (United States)

    Narins, Peter M.; Lewis, Edwin R.

    2004-05-01

    The Namib Desert golden mole is a nocturnal, surface-foraging mammal, possessing a massively hypertrophied malleus which presumably confers low-frequency, substrate-vibration sensitivity through inertial bone conduction. Foraging trails are punctuated with characteristic sand disturbances in which the animal's head dips under the sand. The function of this behavior is not known but it is thought that it may be used to obtain a seismic fix on the next mound to be visited. To test this, we measured the local seismic vibrations both on the top of a mound and on the flats. The spectrum recorded on the flats shows a relatively low-amplitude peak at about 120 Hz, whereas the spectral peak recorded from the mound is nearly 17 dB greater in amplitude and centered at 310 Hz. This suggests that mounds act as seismic beacons for the golden moles that would be detectable from distances corresponding to typical intermound distances of 20-25 m. In addition, out of the 117 species for which data are available, these golden moles have the greatest ossicular mass relative to body size (Mason, personal communication). Functionally, they appear to be low-frequency specialists, and it is likely that golden moles hear through substrate conduction. [Work supported by NIH.

  8. Burrow architecture of the Damaraland mole-rat ( Fukomys ...

    African Journals Online (AJOL)

    The burrow architecture (length, internal dimensions, fractal dimension of tunnel systems, number of nesting chambers and surface mounds) was investigated in the Damaraland mole-rat (Fukomys damarensis). A total of 31 animals were caught from five different colonies and their burrow systems were excavated in their ...

  9. High Pressure Vapor-Liquid Equilibrium of Supercritical Carbon Dioxide + n-Hexane System

    Institute of Scientific and Technical Information of China (English)

    YU Jinglin; TIAN Yiling; ZHU Rongjiao; LIU Zhihua

    2006-01-01

    Vapor-liquid equilibrium data of supercritical carbon dioxide + n-hexane system were measured at 313.15 K,333.15 K,353.15 K,and 373.15 K and their molar volumes and densities were measured both in the subcritical and supercritical regions ranging from 2.15 to 12.63 MPa using a variable-volume autoclave.The thermodynamic properties including mole fractions,densities,and molar volumes of the system were calculated with an equation of state by Heilig and Franck,in which a repulsion term and a square-well potential attraction term for intermolecular interaction was used.The pairwise combination rule was used to calculate the square-well molecular interaction potential and three adjustable parameters (ω,kε,kσ) were obtained.The Heilig-Franck equation of state is found to have good correlation with binary vapor-liquid equilibrium data of the carbon dioxide + n-hexane system.

  10. Cardiac function of the naked mole-rat: ecophysiological responses to working underground.

    Science.gov (United States)

    Grimes, Kelly M; Voorhees, Andrew; Chiao, Ying Ann; Han, Hai-Chao; Lindsey, Merry L; Buffenstein, Rochelle

    2014-03-01

    The naked mole-rat (NMR) is a strictly subterranean rodent with a low resting metabolic rate. Nevertheless, it can greatly increase its metabolic activity to meet the high energetic demands associated with digging through compacted soils in its xeric natural habitat where food is patchily distributed. We hypothesized that the NMR heart would naturally have low basal function and exhibit a large cardiac reserve, thereby mirroring the species' low basal metabolism and large metabolic scope. Echocardiography showed that young (2-4 yr old) healthy NMRs have low fractional shortening (28 ± 2%), ejection fraction (43 ± 2%), and cardiac output (6.5 ± 0.4 ml/min), indicating low basal cardiac function. Histology revealed large NMR cardiomyocyte cross-sectional area (216 ± 10 μm(2)) and cardiac collagen deposition of 2.2 ± 0.4%. Neither of these histomorphometric traits was considered pathological, since biaxial tensile testing showed no increase in passive ventricular stiffness. NMR cardiomyocyte fibers showed a low degree of rotation, contributing to the observed low NMR cardiac contractility. Interestingly, when the exercise mimetic dobutamine (3 μg/g ip) was administered, NMRs showed pronounced increases in fractional shortening, ejection fraction, cardiac output, and stroke volume, indicating an increased cardiac reserve. The relatively low basal cardiac function and enhanced cardiac reserve of NMRs are likely to be ecophysiological adaptations to life in an energetically taxing environment.

  11. Social status and sex effects on neural morphology in Damaraland mole-rats, Fukomys damarensis.

    Science.gov (United States)

    Anyan, Jeff J; Seney, Marianne L; Holley, Amanda; Bengston, Lynn; Goldman, Bruce D; Forger, Nancy G; Holmes, Melissa M

    2011-01-01

    We previously reported that in a eusocial rodent, the naked mole-rat (Heterocephalus glaber), traditional neural sex differences were absent; instead, neural dimorphisms were associated with breeding status. Here we examined the same neural regions previously studied in naked mole-rats in a second eusocial species, the Damaraland mole-rat (Fukomys damarensis). Damaraland mole-rats live in social groups with breeding restricted to a small number of animals. However, colony sizes are much smaller in Damaraland mole-rats than in naked mole-rats and there is consequently less reproductive skew. In this sense, Damaraland mole-rats may be considered intermediate in social organization between naked mole-rats and more traditional laboratory rodents. We report that, as in naked mole-rats, breeding Damaraland mole-rats have larger volumes of the principal nucleus of the bed nucleus of the stria terminalis and paraventricular nucleus of the hypothalamus than do subordinates, with no effect of sex on these measures. Thus, these structures may play special roles in breeders of eusocial species. However, in contrast to what was seen in naked mole-rats, we also found sex differences in Damaraland mole-rats: volume of the medial amygdala and motoneuron number in Onuf's nucleus were both greater in males than in females, with no significant effect of breeding status. Thus, both sex and breeding status influence neural morphology in Damaraland mole-rats. These findings are in accord with the observed sex differences in body weight and genitalia in Damaraland but not naked mole-rats. We hypothesize that the increased sexual dimorphism in Damaraland mole-rats relative to naked mole-rats is related to reduced reproductive skew. 2011 S. Karger AG, Basel.

  12. For Mole Problems, Call Avogadro: 602-1023

    Science.gov (United States)

    Uthe, R. E.

    2002-10-01

    General education students who have never encountered Avogadro’s number often have difficulty grasping its magnitude and the resulting implications for sizes and numbers of particles in common materials they see around them. I have surveyed the approaches used by several chemical educators. This article describes the techniques I find best help introductory students in General College at the University of Minnesota become familiar with Avogadro’s number and mole calculations. They involve estimating numbers of common objects and then calculating the length of time needed to count large numbers of them. For example, the immense amount of time required to count a mole of sand grains at one grain per second greatly exceeds the age of the universe. The calculations also reinforce procedures for manipulating exponents and applying problem-solving techniques.

  13. Continuous fractional distillation of petroleum

    Energy Technology Data Exchange (ETDEWEB)

    1921-11-05

    This invention has for its object a process of distillation, fractional, and continuous, of shale oil, tar, etc., characterized by the vapors leaving the evaporation chamber being forced, before condensation, to go over a continuous circuit. The vapors traverse first a preheater then return to the vaporization chamber in which they are passed along large surfaces and by application of the counter-current principle in contact with the liquid to be distilled. They stream through the chamber in a continuous manner (the quantity of vapor emitted in the circuit being determined in a manner to advance the distillation just to completion); the excess of vapor formed being removed from the circuit and sent to a condensing apparatus for fractionation.

  14. A Mole in the Sole: Case Report on Eccrine Poroma

    Directory of Open Access Journals (Sweden)

    Dr. Arnab Ghosh

    2007-01-01

    Full Text Available Eccrine poroma is a benign tumor which arises from the intraepidermal portion of the eccrine sweat glands. 81 year old diabetic grandma worried about her persistently uncontrolled blood sugar owing to a painless mole in the sole of right foot for 2 years. Excisional biopsy revealed a sweat duct benign eccrine poroma. A relationship with diabetes mellitus could not be clearly established in this case.

  15. Severe Hand Injuries Caused by a Mole Gun

    Directory of Open Access Journals (Sweden)

    Serdar Düzgün

    2017-10-01

    Full Text Available Objective: Injuries by mole guns differ from other firearm injuries primarily because they are close-range, low-energy injuries that are highly contaminated owing to contact with contaminated surfaces and the presence of numerous residual foreign bodies within the wound. The aim of this article is to share our surgical experience regarding the repair of severe hand injuries caused by mole guns. Material and Methods: This retrospective study included 11 patients with hand injuries. Data obtained about the patients, including age, gender, dominant or non-dominant hand, injuries to all vital structures, and reconstructive procedures were assessed, categorized, and recorded. Results: Ten patients had defects in one or several common digital branches of the median nerve in areas ranging from the distal part of the carpal tunnel to the distal palmar crease. All patients had flexor and extensor tendon injuries in all fingers except for the first finger. Reconstruction of soft tissue and skin defects was carried out with an interpolation flap planned from a random-based subpectoral- paraumbilical region in five patients, a SCIA-based groin flap in four patients, a reverse-radial forearm flap in one patient, and an adipofascial flap planned from the forearm in one patient. Conclusion: Mole gun injuries typically include all structures of the hand, and repair procedures involve every anatomic structure of the hand. An early and effective surgical operation followed by prolonged and effective physical therapy protocols is vital for regaining the full spectrum of hand functions.

  16. Mobile vapor recovery and vapor scavenging unit

    International Nuclear Information System (INIS)

    Stokes, C.A.; Steppe, D.E.

    1991-01-01

    This patent describes a mobile anti- pollution apparatus, for the recovery of hydrocarbon emissions. It comprises a mobile platform upon which is mounted a vapor recovery unit for recovering vapors including light hydrocarbons, the vapor recovery unit having an inlet and an outlet end, the inlet end adapted for coupling to an external source of hydrocarbon vapor emissions to recover a portion of the vapors including light hydrocarbons emitted therefrom, and the outlet end adapted for connection to a means for conveying unrecovered vapors to a vapor scavenging unit, the vapor scavenging unit comprising an internal combustion engine adapted for utilizing light hydrocarbon in the unrecovered vapors exiting from the vapor recovery unit as supplemental fuel

  17. Autoignited and non-autoignited lifted flames of pre-vaporized n-heptane in coflow jets at elevated temperatures

    KAUST Repository

    Choi, Sangkyu

    2013-09-01

    The characteristics of laminar lifted flames of pre-vaporized n-heptane in coflow jets were investigated under both non-autoignited and autoignited conditions by varying the initial temperature. The fuel tested was n-heptane considering the importance as a primary reference fuel for gasoline and its low temperature ignition behavior at relatively low pressure. The results showed that the lifted flame edge in the non-autoignited regime had a tribrachial structure with lean and rich premixed flame wings together with a trailing diffusion flame. The liftoff heights correlated reasonably well with the fuel jet velocity scaled by the stoichiometric laminar burning velocity regardless of the initial temperature and the nitrogen dilution. The liftoff velocity multiplied by the buoyancy-induced velocity and the blowout velocity scaled by the mole fraction of the fuel correlated well with the stoichiometric laminar burning velocity. When the initial temperature was above 900. K, flames were autoignited without any external ignition source. Autoignited lifted flames with both tribrachial edges and mild combustion characteristics were observed. The correlation of the liftoff height with the calculated adiabatic ignition delay time was weak, unlike in cases with gaseous fuels of C1-C4 hydrocarbons in which the liftoff height of the autoignited flames correlated well with the square of the adiabatic ignition delay time. When the mole fraction of the fuel was small, mild combustion behaviors were exhibited with edge flames without distinct tribrachial structures. The liftoff height was correlated with the fuel jet velocity scaled by the initial fuel mass fraction, while the dependence on the ignition delay time was weak when compared with the gaseous fuels. © 2013 The Combustion Institute.

  18. Vapor pressures, osmotic and activity coefficients for (LiBr + acetonitrile) between the temperatures (298.15 and 343.15) K

    Energy Technology Data Exchange (ETDEWEB)

    Nasirzadeh, Karamat E-mail: karamat.nasirzadeh@chemie.uni-regensburg.de; Neueder, Roland; Kunz, Werner

    2004-06-01

    Precise vapor pressure data for pure acetonitrile and (LiBr + acetonitrile) are given for temperatures ranging from T=(298.15 to 343.15) K. The molality range is from m=(0.0579 to 0.8298) mol {center_dot} kg{sup -1}. The osmotic coefficients are calculated by taking into account the second virial coefficient of acetonitrile. The parameters of the extended Pitzer ion interaction model of Archer and the mole fraction-based thermodynamic model of Clegg-Pitzer are evaluated. These models accurately reproduce the available osmotic coefficients. The parameters of the extended Pitzer ion interaction model of Archer are used to calculate the mean molal activity coefficients.

  19. Measurement and correlation of vapor-liquid equilibria for a binary system containing 1-butyl-3-methylimidazolium tridecafluorohexyl sulfonate and carbon dioxide

    International Nuclear Information System (INIS)

    Hong, Soon Kang; Park, Yoon Kook

    2016-01-01

    Using a high-pressure variable-volume view cell, the vapor-liquid equilibria of the binary system CO 2 and 1-butyl-3-methylimidazolium tridecafluorohexylsulfonate ([BMIM][TDfO]) were determined. The CO 2 mole fraction ranged from 0.104 to 0.952 over a temperature range of 298.2-323.2 K. Both the Peng-Robinson and Soave-Redlich- Kwong equations of state were applied with two different mixing rules to correlate with the experimentally obtained results. Increasing the alkyl chain length in perfluorinated sulfonate anion mother structure from methyl to hexyl markedly increased the CO 2 solubility. To investigate the effect of the number of fluorine atoms in the anion on the phase behavior of imidazolium-based ionic liquid, these experimental results were then compared with those reported in previous experimental studies of 1-alkyl-3-methylimidazolium cations-including ionic liquid+CO 2 binary system.

  20. Hydatidiform mole: age-related clinical presentation and high rate of severe complications in older women.

    Science.gov (United States)

    Mangili, Giorgia; Giorgione, Veronica; Gentile, Cinzia; Bergamini, Alice; Pella, Francesca; Almirante, Giada; Candiani, Massimo

    2014-05-01

    The purpose of this study was to demonstrate differences in clinical presentation of hydatidiform mole between women ≥40 years and younger women. Retrospective study. A tertiary referral unit in northern Italy. Three hundred and sixty-five women with hydatidiform mole were divided into group A (Clinical presentation between groups A and B was analyzed, also considering partial hydatidiform mole and complete hydatidiform mole. Differences in clinical presentation according to woman's age. In group B the diagnosis of hydatidiform mole at ≥12 gestational weeks was more frequent (p presented with vaginal bleeding (p clinical features of hydatidiform mole in women ≥40 years are different from those seen in younger women. Failures in the early detection of hydatidiform mole in older women may expose them to a higher rate of severe complications. © 2014 Nordic Federation of Societies of Obstetrics and Gynecology.

  1. Electrical Activation Studies of Silicon Implanted Aluminum Gallium Nitride with High Aluminum Mole Fraction

    Science.gov (United States)

    2007-12-01

    like to thank the many friends I have made along the way, Matt Lange, Catherine Taylor, Glen Kading, and Greg Pitz for helping me to remember that life...oxidation. The Ta wrapping wire survives the anneal intact, but becomes brittle enough to easily break off. The samples are taken to the clean room

  2. Petroleum Vapor Intrusion

    Science.gov (United States)

    One type of vapor intrusion is PVI, in which vapors from petroleum hydrocarbons such as gasoline, diesel, or jet fuel enter a building. Intrusion of contaminant vapors into indoor spaces is of concern.

  3. Altered composition of liver proteasome assemblies contributes to enhanced proteasome activity in the exceptionally long-lived naked mole-rat.

    Science.gov (United States)

    Rodriguez, Karl A; Edrey, Yael H; Osmulski, Pawel; Gaczynska, Maria; Buffenstein, Rochelle

    2012-01-01

    The longest-lived rodent, the naked mole-rat (Bathyergidae; Heterocephalus glaber), maintains robust health for at least 75% of its 32 year lifespan, suggesting that the decline in genomic integrity or protein homeostasis routinely observed during aging, is either attenuated or delayed in this extraordinarily long-lived species. The ubiquitin proteasome system (UPS) plays an integral role in protein homeostasis by degrading oxidatively-damaged and misfolded proteins. In this study, we examined proteasome activity in naked mole-rats and mice in whole liver lysates as well as three subcellular fractions to probe the mechanisms behind the apparently enhanced effectiveness of UPS. We found that when compared with mouse samples, naked mole-rats had significantly higher chymotrypsin-like (ChT-L) activity and a two-fold increase in trypsin-like (T-L) in both whole lysates as well as cytosolic fractions. Native gel electrophoresis of the whole tissue lysates showed that the 20S proteasome was more active in the longer-lived species and that 26S proteasome was both more active and more populous. Western blot analyses revealed that both 19S subunits and immunoproteasome catalytic subunits are present in greater amounts in the naked mole-rat suggesting that the observed higher specific activity may be due to the greater proportion of immunoproteasomes in livers of healthy young adults. It thus appears that proteasomes in this species are primed for the efficient removal of stress-damaged proteins. Further characterization of the naked mole-rat proteasome and its regulation could lead to important insights on how the cells in these animals handle increased stress and protein damage to maintain a longer health in their tissues and ultimately a longer life.

  4. Altered composition of liver proteasome assemblies contributes to enhanced proteasome activity in the exceptionally long-lived naked mole-rat.

    Directory of Open Access Journals (Sweden)

    Karl A Rodriguez

    Full Text Available The longest-lived rodent, the naked mole-rat (Bathyergidae; Heterocephalus glaber, maintains robust health for at least 75% of its 32 year lifespan, suggesting that the decline in genomic integrity or protein homeostasis routinely observed during aging, is either attenuated or delayed in this extraordinarily long-lived species. The ubiquitin proteasome system (UPS plays an integral role in protein homeostasis by degrading oxidatively-damaged and misfolded proteins. In this study, we examined proteasome activity in naked mole-rats and mice in whole liver lysates as well as three subcellular fractions to probe the mechanisms behind the apparently enhanced effectiveness of UPS. We found that when compared with mouse samples, naked mole-rats had significantly higher chymotrypsin-like (ChT-L activity and a two-fold increase in trypsin-like (T-L in both whole lysates as well as cytosolic fractions. Native gel electrophoresis of the whole tissue lysates showed that the 20S proteasome was more active in the longer-lived species and that 26S proteasome was both more active and more populous. Western blot analyses revealed that both 19S subunits and immunoproteasome catalytic subunits are present in greater amounts in the naked mole-rat suggesting that the observed higher specific activity may be due to the greater proportion of immunoproteasomes in livers of healthy young adults. It thus appears that proteasomes in this species are primed for the efficient removal of stress-damaged proteins. Further characterization of the naked mole-rat proteasome and its regulation could lead to important insights on how the cells in these animals handle increased stress and protein damage to maintain a longer health in their tissues and ultimately a longer life.

  5. The influence of chemical composition of LNG on the supercritical heat transfer in an intermediate fluid vaporizer

    Science.gov (United States)

    Xu, Shuangqing; Chen, Xuedong; Fan, Zhichao; Chen, Yongdong; Nie, Defu; Wu, Qiaoguo

    2018-04-01

    A three-dimensional transient computational fluid dynamics (CFD) model has been established for the simulations of supercritical heat transfer of real liquefied natural gas (LNG) mixture in a single tube and a tube bundle of an intermediate fluid vaporizer (IFV). The influence of chemical composition of LNG on the thermal performance has been analyzed. The results have also been compared with those obtained from the one-dimensional steady-state calculations using the distributed parameter model (DPM). It is found that the current DPM approach can give reasonable prediction accuracy for the thermal performance in the tube bundle but unsatisfactory prediction accuracy for that in a single tube as compared with the corresponding CFD data. As benchmarked against pure methane, the vaporization of an LNG containing about 90% (mole fraction) of methane would lead to an absolute deviation of 5.5 K in the outlet NG temperature and a maximum relative deviation of 11.4% in the tube side HTC in a bundle of about 816 U tubes at the inlet pressure of 12 MPa and mass flux of 200 kg·m-2·s-1. It is concluded that the influence of LNG composition on the thermal performance should be taken into consideration in order to obtain an economic and reliable design of an IFV.

  6. The risk of persistent trophoblastic disease after hydatidiform mole classified by morphology and ploidy

    DEFF Research Database (Denmark)

    Niemann, Isa; Hansen, Estrid S; Sunde, Lone

    2007-01-01

    classifications, and compared the ability of the two classifications to discriminate between patients with and without a substantial risk of persistent trophoblastic disease. METHODS: 294 cases of consecutively collected hydropic placentas clinically suspected of hydatidiform mole made the basis......OBJECTIVE: Hydatidiform mole can be classified by histopathologic characteristics and by genetic constitutions and most complete moles are diploid, whereas most partial moles are triploid. We investigated the concordance between these two classifications, characterized moles with conflicting......-molar miscarriage, 20 were triploids, 2 were diploid androgenetic and 2 were diploid biparental. In 23% of the conceptuses, the histopathologic and genetic classifications were conflicting. 5% of the patients with hydropic placentas classified as partial mole encountered persistent trophoblastic disease; however...

  7. MOLE 2.0: Advanced approach for analysis of biomacromolecular channels

    OpenAIRE

    Sehnal D.; Varekova R.S.; Berka K.; Pravda L.; Navratilova V.; Banas P.; Ionescu C.-M.; Otyepka M.; Koca J.

    2013-01-01

    Background Channels and pores in biomacromolecules (proteins, nucleic acids and their complexes) play significant biological roles, e.g., in molecular recognition and enzyme substrate specificity. Results We present an advanced software tool entitled MOLE 2.0, which has been designed to analyze molecular channels and pores. Benchmark tests against other available software tools showed that MOLE 2.0 is by comparison quicker, more robust and more versatile. As a new feature, MOLE 2.0 estimates ...

  8. Adult neurogenesis and its anatomical context in the hippocampus of three mole-rat species

    Directory of Open Access Journals (Sweden)

    Irmgard eAmrein

    2014-05-01

    Full Text Available African mole-rats (family Bathyergidae are small to medium sized, long-lived and strictly subterranean rodents that became valuable animal models as a result of their longevity and diversity in social organization. The formation and integration of new hippocampal neurons in adult mammals (adult hippocampal neurogenesis, AHN correlates negatively with age and positively with habitat complexity. Here we present quantitative data on AHN in wild-derived mole-rats of one year and older, and briefly describe its anatomical context including markers of neuronal function (calbindin and parvalbumin. Solitary Cape mole-rats (Georychus capensis, social highveld mole-rats (Cryptomys hottentotus pretoriae, and eusocial naked mole-rats (Heterocephalus glaber were assessed. Compared to other rodents, the hippocampal formation in mole-rats is small, but shows a distinct cytoarchitecture in the dentate gyrus and CA1. Distributions of the calcium-binding proteins differ from those seen in rodents; e.g., calbindin in CA3 of naked mole-rats distributes similar to the pattern seen in early primate development, and calbindin staining extends into the stratum lacunosum-moleculare of Cape mole-rats. Proliferating cells and young neurons are found in low numbers in the hippocampus of all three mole-rat species. Resident granule cell numbers are low as well. Proliferating cells expressed as a percentage of resident granule cells are in the range of other rodents, while the percentage of young neurons is lower than that observed in surface dwelling rodents. Between mole-rat species, we observed no difference in the percentage of proliferating cells. The percentages of young neurons are high in social highveld and naked mole-rats, and low in solitary Cape mole-rats. The findings support that proliferation is regulated independently of average life expectancy and habitat. Instead, neuronal differentiation reflects species-specific demands, which appear lower in subterranean

  9. Adult neurogenesis and its anatomical context in the hippocampus of three mole-rat species.

    Science.gov (United States)

    Amrein, Irmgard; Becker, Anton S; Engler, Stefanie; Huang, Shih-Hui; Müller, Julian; Slomianka, Lutz; Oosthuizen, Maria K

    2014-01-01

    African mole-rats (family Bathyergidae) are small to medium sized, long-lived, and strictly subterranean rodents that became valuable animal models as a result of their longevity and diversity in social organization. The formation and integration of new hippocampal neurons in adult mammals (adult hippocampal neurogenesis, AHN) correlates negatively with age and positively with habitat complexity. Here we present quantitative data on AHN in wild-derived mole-rats of 1 year and older, and briefly describe its anatomical context including markers of neuronal function (calbindin and parvalbumin). Solitary Cape mole-rats (Georychus capensis), social highveld mole-rats (Cryptomys hottentotus pretoriae), and eusocial naked mole-rats (Heterocephalus glaber) were assessed. Compared to other rodents, the hippocampal formation in mole-rats is small, but shows a distinct cytoarchitecture in the dentate gyrus and CA1. Distributions of the calcium-binding proteins differ from those seen in rodents; e.g., calbindin in CA3 of naked mole-rats distributes similar to the pattern seen in early primate development, and calbindin staining extends into the stratum lacunosum-moleculare of Cape mole-rats. Proliferating cells and young neurons are found in low numbers in the hippocampus of all three mole-rat species. Resident granule cell numbers are low as well. Proliferating cells expressed as a percentage of resident granule cells are in the range of other rodents, while the percentage of young neurons is lower than that observed in surface dwelling rodents. Between mole-rat species, we observed no difference in the percentage of proliferating cells. The percentages of young neurons are high in social highveld and naked mole-rats, and low in solitary Cape mole-rats. The findings support that proliferation is regulated independently of average life expectancy and habitat. Instead, neuronal differentiation reflects species-specific demands, which appear lower in subterranean rodents.

  10. High molecular weight hyaluronan mediates the cancer resistance of the naked mole-rat

    Science.gov (United States)

    Tian, Xiao; Azpurua, Jorge; Hine, Christopher; Vaidya, Amita; Myakishev-Rempel, Max; Ablaeva, Julia; Mao, Zhiyong; Nevo, Eviatar; Gorbunova, Vera; Seluanov, Andrei

    2013-01-01

    The naked mole-rat displays exceptional longevity, with a maximum lifespan exceeding 30 years1–3. This is the longest reported lifespan for a rodent species and is especially striking considering the small body mass of the naked mole-rat. In comparison, a similarly sized house mouse has a maximum lifespan of 4 years4,5. In addition to their longevity, naked mole-rats show an unusual resistance to cancer. Multi-year observations of large naked mole-rat colonies did not detect a single incidence of cancer2,6. Here we identify a mechanism responsible for the naked mole-rat’s cancer resistance. We found that naked mole-rat fibroblasts secrete extremely high molecular weight hyaluronan (HA), which is over five times larger than human or mouse HA. This high molecular weight HA accumulates abundantly in naked mole rat tissues due to the decreased activity of HA-degrading enzymes and a unique sequence of hyaluronan synthase 2 (HAS2). Furthermore, the naked mole-rat cells are more sensitive to HA signaling, as the naked mole rat cells have a higher affinity to HA than the mouse or human cells. Perturbation of the signaling pathways sufficient for malignant transformation of mouse fibroblasts fails to transform naked mole-rat cells. However, once high molecular weight HA is removed by either knocking down HAS2 or overexpressing the HA-degrading enzyme, Hyal2, naked mole-rat cells become susceptible to malignant transformation and readily form tumors in mice. We speculate that naked mole-rats have evolved a higher concentration of HA in the skin to provide skin elasticity needed for life in underground tunnels. This trait may have then been co-opted to provide cancer resistance and longevity to this species. PMID:23783513

  11. [Complete hydatiforme mole in Morocco: epidemiological and clinical study].

    Science.gov (United States)

    Boufettal, H; Coullin, P; Mahdaoui, S; Noun, M; Hermas, S; Samouh, N

    2011-09-01

    Complete hydatidiform moles (CHM) are a real public health problem, especially in the "southern countries" and Asia, because of their impact on the female reproduction and the risk to progression to either invasive mole or choriocarcinoma. We collected the cases of CHM referred to our department over a period of ten years (2000 to 2009). We will present our results, emphasize the modalities of diagnosis, treatment and evolution, with a review of literature. During this study, we identified 254 cases of CHM, and recorded 57,987 births and 1627 abortions. Their incidence was 0.43% of pregnancies. The mean age of our patients is 25 years old (16 to 55). Relative risk observed was much increased among women under 20 years old (×6.8) and those over 40 years old (×15). Both of nulliparous and primiparous patients represented 52.3% of the cohort. Eighty-five percent of patients belonged to an agricultural environment associated with a low socio-economic status. Uterine bleeding was the most common symptom accounting for 93.7%. Toxic syndrome was present in 18.5% of patients. Physical examination showed a highly increased uterine size in 85% of cases associated with lateral uterine mass in 25% of cases. The diagnosis was suspected using ultrasonography in all cases associated with an elevated level of plasmatic β-human chorionic gonadotrophin (βhCG). All cases were confirmed histologically. Treatment used was endo-uterine aspiration in all cases. Recurrence of CHM was documented in 25 patients or 9.4%. Neoplasic progression was observed for 6.3% of cases. All of them have evolved into remission with chemotherapy. CHM continue to be a public health problem in Morocco, their incidence is among the highest ones. In fact, this studied population corresponds to the lowest socio-economic status and generally described as population at risk. It is subject to drastic weather's conditions causing loss of fresh products. Extreme ages and degree of parity are also risk factors

  12. High molecular weight hyaluronan mediates the cancer resistance of the naked mole-rat

    OpenAIRE

    Tian, Xiao; Azpurua, Jorge; Hine, Christopher; Vaidya, Amita; Myakishev-Rempel, Max; Ablaeva, Julia; Mao, Zhiyong; Nevo, Eviatar; Gorbunova, Vera; Seluanov, Andrei

    2013-01-01

    The naked mole-rat displays exceptional longevity, with a maximum lifespan exceeding 30 years 1–3 . This is the longest reported lifespan for a rodent species and is especially striking considering the small body mass of the naked mole-rat. In comparison, a similarly sized house mouse has a maximum lifespan of 4 years 4,5 . In addition to their longevity, naked mole-rats show an unusual resistance to cancer. Multi-year observations of large naked mole-rat colonies did not detect a single inci...

  13. Application of the MOLE in post-nuclear accident characterization

    International Nuclear Information System (INIS)

    Johnson, S.J.; Alvarez, J.L.

    1981-01-01

    Following a nuclear accident there is a need to determine the chemical composition of materials in liquid, solid and gaseous form, the crystalline structure of solids, the size and chemical composition of particles, and the chemical characterization of contaminants on surfaces. This analytical information is required to reconstruct the accident scenario, to select decontamination methods, and to determine future safety requirements. The MOLE (Molecular Optical Laser Examiner) is a Raman microprobe system which has proven to be a valuable analytical tool in providing this type of chemical information. It can determine the chemical species of polyatomic molecules and ions having characteristic Raman spectra. As little as 1 picogram of a component or a 1 μm particle can be analyzed. The imaging system can also provide mapping of selected components on a surface. A system description, sample handling techniques, and applications are presented. Specific applications to the Three Mile Island-Unit 2 accident are also addressed

  14. Placentation in the Hottentot golden mole, Amblysomus hottentotus (Afrosoricida: Chrysochloridae)

    DEFF Research Database (Denmark)

    Jones, C J P; Carter, A M; Bennett, N C

    2009-01-01

    The placentation of the Hottentot golden mole (Amblysomus hottentotus) has been examined using light and electron microscopy and lectin histochemistry of nine specimens at both mid and late gestation. The placentae were lobulated towards the allantoic surface and the lobules contained roughly...... parallel arrays of labyrinthine structures converging on a central spongy zone. At mid gestation, the arrays were composed of an inner cellular and outer syncytial trophoblast layer, the inner layer enclosing scant connective tissue and fetal capillaries. Maternal blood spaces coursed through the outer...... trophoblast and were lined by trophoblastic microvilli; the blood spaces were narrow in mid gestation but enlarged near term, while the inner trophoblast layer became thinner and seemed to be syncytial. These features were confirmed by transmission electron microscopy. The microvillous surfaces and dispersed...

  15. A phylogenetic estimate for golden moles (Mammalia, Afrotheria, Chrysochloridae

    Directory of Open Access Journals (Sweden)

    Bloomer Paulette

    2010-03-01

    Full Text Available Abstract Background Golden moles (Chrysochloridae are small, subterranean, afrotherian mammals from South Africa and neighboring regions. Of the 21 species now recognized, some (e.g., Chrysochloris asiatica, Amblysomus hottentotus are relatively common, whereas others (e.g., species of Chrysospalax, Cryptochloris, Neamblysomus are rare and endangered. Here, we use a combined analysis of partial sequences of the nuclear GHR gene and morphological characters to derive a phylogeny of species in the family Chrysochloridae. Results Although not all nodes of the combined analysis have high support values, the overall pattern of relationships obtained from different methods of phylogeny reconstruction allow us to make several recommendations regarding the current taxonomy of golden moles. We elevate Huetia to generic status to include the species leucorhinus and confirm the use of the Linnean binomial Carpitalpa arendsi, which belongs within Amblysominae along with Amblysomus and Neamblysomus. A second group, Chrysochlorinae, includes Chrysochloris, Cryptochloris, Huetia, Eremitalpa, Chrysospalax, and Calcochloris. Bayesian methods make chrysochlorines paraphyletic by placing the root within them, coinciding with root positions favored by a majority of randomly-generated outgroup taxa. Maximum Parsimony (MP places the root either between chrysochlorines and amblysomines (with Chlorotalpa as sister taxon to amblysomines, or at Chlorotalpa, with the former two groups reconstructed as monophyletic in all optimal MP trees. Conclusions The inclusion of additional genetic loci for this clade is important to confirm our taxonomic results and resolve the chrysochlorid root. Nevertheless, our optimal topologies support a division of chrysochlorids into amblysomines and chrysochlorines, with Chlorotalpa intermediate between the two. Furthermore, evolution of the chrysochlorid malleus exhibits homoplasy. The elongate malleus has evolved just once in the

  16. A phylogenetic estimate for golden moles (Mammalia, Afrotheria, Chrysochloridae).

    Science.gov (United States)

    Asher, Robert J; Maree, Sarita; Bronner, Gary; Bennett, Nigel C; Bloomer, Paulette; Czechowski, Paul; Meyer, Matthias; Hofreiter, Michael

    2010-03-09

    Golden moles (Chrysochloridae) are small, subterranean, afrotherian mammals from South Africa and neighboring regions. Of the 21 species now recognized, some (e.g., Chrysochloris asiatica, Amblysomus hottentotus) are relatively common, whereas others (e.g., species of Chrysospalax, Cryptochloris, Neamblysomus) are rare and endangered. Here, we use a combined analysis of partial sequences of the nuclear GHR gene and morphological characters to derive a phylogeny of species in the family Chrysochloridae. Although not all nodes of the combined analysis have high support values, the overall pattern of relationships obtained from different methods of phylogeny reconstruction allow us to make several recommendations regarding the current taxonomy of golden moles. We elevate Huetia to generic status to include the species leucorhinus and confirm the use of the Linnean binomial Carpitalpa arendsi, which belongs within Amblysominae along with Amblysomus and Neamblysomus. A second group, Chrysochlorinae, includes Chrysochloris, Cryptochloris, Huetia, Eremitalpa, Chrysospalax, and Calcochloris. Bayesian methods make chrysochlorines paraphyletic by placing the root within them, coinciding with root positions favored by a majority of randomly-generated outgroup taxa. Maximum Parsimony (MP) places the root either between chrysochlorines and amblysomines (with Chlorotalpa as sister taxon to amblysomines), or at Chlorotalpa, with the former two groups reconstructed as monophyletic in all optimal MP trees. The inclusion of additional genetic loci for this clade is important to confirm our taxonomic results and resolve the chrysochlorid root. Nevertheless, our optimal topologies support a division of chrysochlorids into amblysomines and chrysochlorines, with Chlorotalpa intermediate between the two. Furthermore, evolution of the chrysochlorid malleus exhibits homoplasy. The elongate malleus has evolved just once in the Cryptochloris-Chrysochloris group; other changes in shape have

  17. Comparative morphology of the penis and clitoris in four species of moles (Talpidae)

    Science.gov (United States)

    Sinclair, Adriane Watkins; Glickman, Stephen; Catania, Kenneth; Shinohara, Akio; Baskin, Lawrence; Cunha, Gerald R.

    2017-01-01

    The penile and clitorial anatomy of four species of Talpid moles (broad-footed, star-nosed, hairy-tailed, and Japanese shrew moles) were investigated to define penile and clitoral anatomy and to examine the relationship of the clitoral anatomy with the presence or absence of ovotestes. The ovotestis contains ovarian tissue and glandular tissue resembling fetal testicular tissue and can produce androgens. The ovotestis is present in star-nosed and hairy-tailed moles, but not in broad-footed and Japanese shrew moles. Using histology, 3D reconstruction, and morphometric analysis, sexual dimorphism was examined in regard to a nine feature masculine trait score that included perineal appendage length (prepuce), anogenital distance, and presence/absence of bone. The presence/absence of ovotestes was discordant in all four mole species for sex differentiation features. For many sex differentiation features, discordance with ovotestes was observed in at least one mole species. The degree of concordance with ovotestes was highest for hairy-tailed moles and lowest for broad-footed moles. In relationship to phylogenetic clade, sex differentiation features also did not correlate with the similarity/divergence of the features and presence/absence of ovotestes. Hairy-tailed and Japanese shrew moles reside in separated clades, but they exhibit a high degree of congruence. Broad-footed and hairy-tailed moles reside within the same clade but had one of the lowest correlations in features and presence/absence of ovotestes. Thus, phylogenetic affinity and the presence/absence of ovotestes are poor predictors for most sex differentiation features within mole external genitalia. PMID:28251823

  18. High-molecular-mass hyaluronan mediates the cancer resistance of the naked mole rat.

    Science.gov (United States)

    Tian, Xiao; Azpurua, Jorge; Hine, Christopher; Vaidya, Amita; Myakishev-Rempel, Max; Ablaeva, Julia; Mao, Zhiyong; Nevo, Eviatar; Gorbunova, Vera; Seluanov, Andrei

    2013-07-18

    The naked mole rat (Heterocephalus glaber) displays exceptional longevity, with a maximum lifespan exceeding 30 years. This is the longest reported lifespan for a rodent species and is especially striking considering the small body mass of the naked mole rat. In comparison, a similarly sized house mouse has a maximum lifespan of 4 years. In addition to their longevity, naked mole rats show an unusual resistance to cancer. Multi-year observations of large naked mole-rat colonies did not detect a single incidence of cancer. Here we identify a mechanism responsible for the naked mole rat's cancer resistance. We found that naked mole-rat fibroblasts secrete extremely high-molecular-mass hyaluronan (HA), which is over five times larger than human or mouse HA. This high-molecular-mass HA accumulates abundantly in naked mole-rat tissues owing to the decreased activity of HA-degrading enzymes and a unique sequence of hyaluronan synthase 2 (HAS2). Furthermore, the naked mole-rat cells are more sensitive to HA signalling, as they have a higher affinity to HA compared with mouse or human cells. Perturbation of the signalling pathways sufficient for malignant transformation of mouse fibroblasts fails to transform naked mole-rat cells. However, once high-molecular-mass HA is removed by either knocking down HAS2 or overexpressing the HA-degrading enzyme, HYAL2, naked mole-rat cells become susceptible to malignant transformation and readily form tumours in mice. We speculate that naked mole rats have evolved a higher concentration of HA in the skin to provide skin elasticity needed for life in underground tunnels. This trait may have then been co-opted to provide cancer resistance and longevity to this species.

  19. Trading new neurons for status: Adult hippocampal neurogenesis in eusocial Damaraland mole-rats.

    Science.gov (United States)

    Oosthuizen, M K; Amrein, I

    2016-06-02

    Diversity in social structures, from solitary to eusocial, is a prominent feature of subterranean African mole-rat species. Damaraland mole-rats are eusocial, they live in colonies that are characterized by a reproductive division of labor and a subdivision into castes based on physiology and behavior. Damaraland mole-rats are exceptionally long lived and reproductive animals show delayed aging compared to non-reproductive animals. In the present study, we described the hippocampal architecture and the rate of hippocampal neurogenesis of wild-derived, adult Damaraland mole-rats in relation to sex, relative age and social status or caste. Overall, Damaraland mole-rats were found to have a small hippocampus and low rates of neurogenesis. We found no correlation between neurogenesis and sex or relative age. Social status or caste was the most prominent modulator of neurogenesis. An inverse relationship between neurogenesis and social status was apparent, with queens displaying the lowest neurogenesis while the worker mole-rats had the most. As there is no natural progression from one caste to another, social status within a colony was relatively stable and is reflected in the level of neurogenesis. Our results correspond to those found in the naked mole-rat, and may reflect an evolutionary and environmentally conserved trait within social mole-rat species. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

  20. Optimization of operating parameters in polysilicon chemical vapor deposition reactor with response surface methodology

    Science.gov (United States)

    An, Li-sha; Liu, Chun-jiao; Liu, Ying-wen

    2018-05-01

    In the polysilicon chemical vapor deposition reactor, the operating parameters are complex to affect the polysilicon's output. Therefore, it is very important to address the coupling problem of multiple parameters and solve the optimization in a computationally efficient manner. Here, we adopted Response Surface Methodology (RSM) to analyze the complex coupling effects of different operating parameters on silicon deposition rate (R) and further achieve effective optimization of the silicon CVD system. Based on finite numerical experiments, an accurate RSM regression model is obtained and applied to predict the R with different operating parameters, including temperature (T), pressure (P), inlet velocity (V), and inlet mole fraction of H2 (M). The analysis of variance is conducted to describe the rationality of regression model and examine the statistical significance of each factor. Consequently, the optimum combination of operating parameters for the silicon CVD reactor is: T = 1400 K, P = 3.82 atm, V = 3.41 m/s, M = 0.91. The validation tests and optimum solution show that the results are in good agreement with those from CFD model and the deviations of the predicted values are less than 4.19%. This work provides a theoretical guidance to operate the polysilicon CVD process.

  1. Measurement of atmospheric carbon dioxide and water vapor in built-up urban areas in the Gandhinagar-Ahmedabad region in India using a portable tunable diode laser spectroscopy system.

    Science.gov (United States)

    Roy, Anirban; Sharma, Neetesh Kumar; Chakraborty, Arup Lal; Upadhyay, Abhishek

    2017-11-01

    This paper reports open-path in situ measurements of atmospheric carbon dioxide at Gandhinagar (23.2156°N, 72.6369°E) and Ahmedabad (23.0225°N, 72.5714°E) in the heavily industrialized state of Gujarat in western India. Calibration-free second harmonic wavelength modulation spectroscopy (2f WMS) is used to carry out accurate and fully automated measurements. The mean values of the mole fraction of carbon dioxide at four locations were 438 ppm, 495 ppm, 550 ppm, and 740 ppm, respectively. These values are much higher than the current global average of 406.67 ppm. A 1 mW, 2004-nm vertical cavity surface-emitting laser is used to selectively interrogate the R16 transition of carbon dioxide at 2003.5 nm (4991.2585 cm -1 ). The 2f WMS signal corresponding to the gas absorption line shape is simulated using spectroscopic parameters available in the HITRAN database and relevant laser parameters that are extracted in situ from non-absorbing spectral wings of the harmonic signals. The mole fraction of carbon dioxide is extracted in real-time by a MATLAB program from least-squares fit of the simulated 2f WMS signal to the corresponding experimentally obtained signal. A 10-mW, 1392.54-nm distributed feedback laser is used at two of the locations to carry out water vapor measurements using direct absorption spectroscopy. This is the first instance of a portable tunable diode laser spectroscopy system being deployed in an urban location in India to measure atmospheric carbon dioxide and water vapor under varying traffic conditions. The measurements clearly demonstrate the need to adopt tunable diode laser spectroscopy for precise long-term monitoring of greenhouse gases in the Indian subcontinent.

  2. Genome sequencing reveals insights into physiology and longevity of the naked mole rat

    DEFF Research Database (Denmark)

    Kim, Eun Bae; Fang, Xiaodong; Fushan, Alexey A

    2011-01-01

    The naked mole rat (Heterocephalus glaber) is a strictly subterranean, extraordinarily long-lived eusocial mammal. Although it is the size of a mouse, its maximum lifespan exceeds 30 years, making this animal the longest-living rodent. Naked mole rats show negligible senescence, no age......-related increase in mortality, and high fecundity until death. In addition to delayed ageing, they are resistant to both spontaneous cancer and experimentally induced tumorigenesis. Naked mole rats pose a challenge to the theories that link ageing, cancer and redox homeostasis. Although characterized...... by significant oxidative stress, the naked mole rat proteome does not show age-related susceptibility to oxidative damage or increased ubiquitination. Naked mole rats naturally reside in large colonies with a single breeding female, the 'queen', who suppresses the sexual maturity of her subordinates. They also...

  3. The Naked Mole Rat Genome Resource: facilitating analyses of cancer and longevity-related adaptations.

    Science.gov (United States)

    Keane, Michael; Craig, Thomas; Alföldi, Jessica; Berlin, Aaron M; Johnson, Jeremy; Seluanov, Andrei; Gorbunova, Vera; Di Palma, Federica; Lindblad-Toh, Kerstin; Church, George M; de Magalhães, João Pedro

    2014-12-15

    The naked mole rat (Heterocephalus glaber) is an exceptionally long-lived and cancer-resistant rodent native to East Africa. Although its genome was previously sequenced, here we report a new assembly sequenced by us with substantially higher N50 values for scaffolds and contigs. We analyzed the annotation of this new improved assembly and identified candidate genomic adaptations which may have contributed to the evolution of the naked mole rat's extraordinary traits, including in regions of p53, and the hyaluronan receptors CD44 and HMMR (RHAMM). Furthermore, we developed a freely available web portal, the Naked Mole Rat Genome Resource (http://www.naked-mole-rat.org), featuring the data and results of our analysis, to assist researchers interested in the genome and genes of the naked mole rat, and also to facilitate further studies on this fascinating species. © The Author 2014. Published by Oxford University Press.

  4. Acanthocephala Parasite (Profilicollis spp.) Loads in Correlation to Pacific Mole Crab (Emerita analoga) Size

    Science.gov (United States)

    Cheng, T.; Huang, S.; Galathe, M.; Jenkins, M.; Ramirez, A.; Crosby, L.; Barrera, J.; FitzHoward, S.

    2013-12-01

    Since 2002, San Francisco Bay students have been conducting marine ecosystem monitoring through a joint project with the Long-term Monitoring Program and Experiential Training for Students (LiMPETS), in conjunction with the Gulf of Farallones National Marine Sanctuary. Each year students collect population and demographic data on Pacific mole crabs (Emerita analoga), an indicator species that lives in the sandy beach habitat in temperate regions along the Pacific Ocean. Pacific mole crabs are filter feeding crustaceans that inhabit the intertidal swash zone and are known to be an intermediate host for parasitic ';spiny-headed' worms in the phylum Acanthocephala (Profilicollis spp.). Sampling takes place during their reproductive period, which occurs from spring to fall, and includes measuring total body length of the Pacific mole crabs and dissecting them to determine presence of Acanthocephalan parasites. We hypothesize that due to larger body mass, larger Pacific mole crabs will have a greater number of Acanthocephala parasites.We conducted several analyses using the LiMPETS long-term data. Specifically, we compared body length, crab gender, and parasite abundance from Pacific mole crabs sampled from four beaches located in the county and city of San Francisco. Our results indicated that larger Pacific mole crabs do not necessarily have more parasites, but are more likely to have at least one parasite, while female Pacific mole crabs carrying eggs, have more parasites than males or females without eggs. We also found that parasite loads per mole crab was highest in the spring. Further analysis will be conducted to determine factors affecting Pacific mole crab parasite loads. Studying Pacific mole crabs help evaluate the health of California's intertidal systems and how human activities, geologic changes, and climate changes all make huge impacts to the intertidal ecosystems.

  5. Tecidos moles (não resistentes: como se fossilizam?

    Directory of Open Access Journals (Sweden)

    Silvia Regina Gobbo

    2015-06-01

    Full Text Available A preservação de tecidos moles (não resistentes desperta atenção pela qualidade dos fósseis preservados, e pela raridade. Este trabalho faz ampla revisão do assunto, desfaz alguns dos mitos correntes sobre fossilização destes materiais, como anaerobiose e soterramento rápido, bem como assinala a relevância do papel da replicagem de estruturas morfológicas por colônias microbianas. No âmbito dos fatores que influenciam a preservação de tecidos não resistentes estão pH, processos de decomposição, soterramento rápido e mineralização rápida por meio de carbonatos ou fosfatos. É possível citar exemplos de fácies sedimentares nas quais há preservação de tecidos não resistentes, como os folhelhos pirobetuminosos, calcários litográficos, folhelhos e diatomitos. Destaca-se o papel das colônias microbianas, tanto na forma de microesferas, como aquelas não-esferulíticas. Os três mitos principais que se procurou desfazer no artigo são: (1 a presença de oxigênio; (2 o soterramento rápido e (3 as colônias microbianas.

  6. Calculating the enthalpy of vaporization for ionic liquid clusters.

    Science.gov (United States)

    Kelkar, Manish S; Maginn, Edward J

    2007-08-16

    Classical atomistic simulations are used to compute the enthalpy of vaporization of a series of ionic liquids composed of 1-alkyl-3-methylimidazolium cations paired with the bis(trifluoromethylsulfonyl)imide anion. The calculations show that the enthalpy of vaporization is lowest for neutral ion pairs. The enthalpy of vaporization increases by about 40 kJ/mol with the addition of each ion pair to the vaporizing cluster. Non-neutral clusters have much higher vaporization enthalpies than their neutral counterparts and thus are not expected to make up a significant fraction of volatile species. The enthalpy of vaporization increases slightly as the cation alkyl chain length increases and as temperature decreases. The calculated vaporization enthalpies are consistent with two sets of recent experimental measurements as well as with previous atomistic simulations.

  7. Partial hydatidiform mole with false-negative urine human chorionic gonadatropin test in the emergency department.

    Science.gov (United States)

    Mundangepfupfu, Tichaendepi; Waseem, Muhammad

    2014-03-01

    Hydatidiform mole (molar pregnancy) is a benign tumor of placental trophoblastic cells, which release human chorionic gonadotropin (hCG). Several case reports have described complete hydatidiform moles with false-negative urine qualitative hCG tests. These negative pregnancy tests have been attributed to the hook effect. We report an unusual presentation of a partial mole and review an alternative explanation for the negative hCG test. As partial moles are usually not associated with a large proliferation of trophoblastic cells, levels of hCG are commonly negative and serum quantitative hCG was 1,094,950 mIU/mL. Pelvic ultrasonography showed a uterine cavity containing a soft-tissue mass with multiple cystic lesions and the hydatidiform mole was extracted with suction curettage. Tissue pathology confirmed partial hydatidiform mole. In addition to the hook effect, we present another possible explanation for the false-negative test; namely the inability of some assays to detect hCG-degradation products, which may be higher in clinical samples from patients with hydatidiform mole. This case underscores the importance of knowing the limitations of the commonly used hCG assays. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Sleep in the Cape Mole Rat: A Short-Sleeping Subterranean Rodent.

    Science.gov (United States)

    Kruger, Jean-Leigh; Gravett, Nadine; Bhagwandin, Adhil; Bennett, Nigel C; Archer, Elizabeth K; Manger, Paul R

    2016-01-01

    The Cape mole rat Georychus capensis is a solitary subterranean rodent found in the western and southern Cape of South Africa. This approximately 200-gram bathyergid rodent shows a nocturnal circadian rhythm, but sleep in this species is yet to be investigated. Using telemetric recordings of the electroencephalogram (EEG) and electromyogram (EMG) in conjunction with video recordings, we were able to show that the Cape mole rat, like all other rodents, has sleep periods composed of both rapid eye movement (REM) and slow-wave (non-REM) sleep. These mole rats spent on average 15.4 h awake, 7.1 h in non-REM sleep and 1.5 h in REM sleep each day. Cape mole rats sleep substantially less than other similarly sized terrestrial rodents but have a similar percentage of total sleep time occupied by REM sleep. In addition, the duration of both non-REM and REM sleep episodes was markedly shorter in the Cape mole rat than has been observed in terrestrial rodents. Interestingly, these features (total sleep time and episode duration) are similar to those observed in another subterranean bathyergid mole rat, i.e. Fukomys mechowii. Thus, there appears to be a bathyergid type of sleep amongst the rodents that may be related to their environment and the effect of this on their circadian rhythm. Investigating further species of bathyergid mole rats may fully define the emerging picture of sleep in these subterranean African rodents. © 2016 S. Karger AG, Basel.

  9. Selective inflammatory pain insensitivity in the African naked mole-rat (Heterocephalus glaber).

    Science.gov (United States)

    Park, Thomas J; Lu, Ying; Jüttner, René; Smith, Ewan St J; Hu, Jing; Brand, Antje; Wetzel, Christiane; Milenkovic, Nevena; Erdmann, Bettina; Heppenstall, Paul A; Laurito, Charles E; Wilson, Steven P; Lewin, Gary R

    2008-01-01

    In all mammals, tissue inflammation leads to pain and behavioral sensitization to thermal and mechanical stimuli called hyperalgesia. We studied pain mechanisms in the African naked mole-rat, an unusual rodent species that lacks pain-related neuropeptides (e.g., substance P) in cutaneous sensory fibers. Naked mole-rats show a unique and remarkable lack of pain-related behaviors to two potent algogens, acid and capsaicin. Furthermore, when exposed to inflammatory insults or known mediators, naked mole-rats do not display thermal hyperalgesia. In contrast, naked mole-rats do display nocifensive behaviors in the formalin test and show mechanical hyperalgesia after inflammation. Using electrophysiology, we showed that primary afferent nociceptors in naked mole-rats are insensitive to acid stimuli, consistent with the animal's lack of acid-induced behavior. Acid transduction by sensory neurons is observed in birds, amphibians, and fish, which suggests that this tranduction mechanism has been selectively disabled in the naked mole-rat in the course of its evolution. In contrast, nociceptors do respond vigorously to capsaicin, and we also show that sensory neurons express a transient receptor potential vanilloid channel-1 ion channel that is capsaicin sensitive. Nevertheless, the activation of capsaicin-sensitive sensory neurons in naked mole-rats does not produce pain-related behavior. We show that capsaicin-sensitive nociceptors in the naked mole-rat are functionally connected to superficial dorsal horn neurons as in mice. However, the same nociceptors are also functionally connected to deep dorsal horn neurons, a connectivity that is rare in mice. The pain biology of the naked mole-rat is unique among mammals, thus the study of pain mechanisms in this unusual species can provide major insights into what constitutes "normal" mammalian nociception.

  10. Selective inflammatory pain insensitivity in the African naked mole-rat (Heterocephalus glaber.

    Directory of Open Access Journals (Sweden)

    Thomas J Park

    2008-01-01

    Full Text Available In all mammals, tissue inflammation leads to pain and behavioral sensitization to thermal and mechanical stimuli called hyperalgesia. We studied pain mechanisms in the African naked mole-rat, an unusual rodent species that lacks pain-related neuropeptides (e.g., substance P in cutaneous sensory fibers. Naked mole-rats show a unique and remarkable lack of pain-related behaviors to two potent algogens, acid and capsaicin. Furthermore, when exposed to inflammatory insults or known mediators, naked mole-rats do not display thermal hyperalgesia. In contrast, naked mole-rats do display nocifensive behaviors in the formalin test and show mechanical hyperalgesia after inflammation. Using electrophysiology, we showed that primary afferent nociceptors in naked mole-rats are insensitive to acid stimuli, consistent with the animal's lack of acid-induced behavior. Acid transduction by sensory neurons is observed in birds, amphibians, and fish, which suggests that this tranduction mechanism has been selectively disabled in the naked mole-rat in the course of its evolution. In contrast, nociceptors do respond vigorously to capsaicin, and we also show that sensory neurons express a transient receptor potential vanilloid channel-1 ion channel that is capsaicin sensitive. Nevertheless, the activation of capsaicin-sensitive sensory neurons in naked mole-rats does not produce pain-related behavior. We show that capsaicin-sensitive nociceptors in the naked mole-rat are functionally connected to superficial dorsal horn neurons as in mice. However, the same nociceptors are also functionally connected to deep dorsal horn neurons, a connectivity that is rare in mice. The pain biology of the naked mole-rat is unique among mammals, thus the study of pain mechanisms in this unusual species can provide major insights into what constitutes "normal" mammalian nociception.

  11. Traceability of pH to the Mole

    Directory of Open Access Journals (Sweden)

    Maria Filomena Camões

    2015-08-01

    Full Text Available Free acidity of aqueous solutions was initially defined in 1909 by Søren Peter Lauritz Sørensen as pH = −lgcH+ (c/mol·dm−3 or m/mol·kg−1 of the free hydrogen ions in solution, H+ soon (1910 was changed to pH = paH+ = −lgaH+, integrating the new concepts of activity, ai and activity coefficient γi, for the ionic species i under concern, H+ in this case; it is ai = −lg(miγi. Since individual ions do not exist alone in solution, primary pH values cannot be assigned solely by experimental measurements, requiring extra thermodynamic model assumptions for the activity coefficient, γH+, which has put pH in a unique situation of not being fully traceable to the International System of Units (SI. Also the concept of activity is often not felt to be as perceptible as that of concentration which may present difficulties, namely with the interpretation of data. pH measurements on unknown samples rely on calibration of the measuring setup with adequate reference pH buffers. In this work, the assignment of pH values to buffers closely matching the samples, e.g., seawater, is revisited. An approach is presented to assess the quantity pmH+ = −lgmH+ profiting from the fact that, contrary to single ion activity coefficients, mean activity coefficients,   can be assessed based on experimentally assessed quantities alone, γExp ±, thus ensuring traceability to the mole, the SI base unit for amount of substance. Compatibility between γExp ± and mean activity coefficient calculated by means of Pitzer model equations, γPtz ±, validates the model for its intended use.

  12. Assessment of Visitor Satisfaction in Mole National Park, Ghana

    Directory of Open Access Journals (Sweden)

    Conrad-J.Wuleka Kuuder

    2013-01-01

    Full Text Available Arrivals to Mole National Park (MNP, the largest in Ghana were projected by management to reach 100,000 guests by the close of2010. As at the end of December 2008, the park recorded only 16, 807 guest arrivals, the highest so far in its existence. By the close of year 2010, only 14,336 tourist arrivals were recorded registering a drop, hence an illusion in attaining the2010 set target and even subsequent years to come. This therefore gave a clue that revenue generated is not always enough to support park administration and community development. This paper explores the underlying reasons accounting for this trend by finding out tourists’ preferences in the park, the category of people who patronized the park most and sourcing guest views on what can be done to make the park more attractive. A five month period was used to elicit information from498 tourists who visited the Park employing questionnaire administration and interview schedules. The results analyzed revealed that student groups in second cycle and tertiary institutions patronized the park most on the domestic front, whilst on the foreign front, all guests contacted were educated above high school level and many of them (57% were on holiday in Ghana. The driving force (motivation behind these visits was to see animals in the wild. The most preferred wildlife species visitors came to view were elephants, monkeys, lions, buffalo and birds respectively. The recommendation is made that the road linking major cities and towns to the Park which is “rough and rugged” be rehabilitated if government needs to improve tourists’ inflow to the park.

  13. Tourism potentials of Mole National Park in Northern Ghana

    Directory of Open Access Journals (Sweden)

    Conrad Wuleka Kuuder

    2012-01-01

    Full Text Available Poor access and long distances from major cities/towns have always been major problems debarring the full utilization of nature-related touristic resources. Despite this, some adventuresome tourists still make efforts to such wildlife sanctuaries to have a feel of nature. This study explores tourism exploits at Mole National Park (the largest in Ghana which is located in the northern sector of the country. An inventory of facilities through field visits and observations were ‘exacted’ to identify different types of landforms, species of wildlife, vegetation and culture which were of touristic significance around the Park and also to have an overview of tourists’ “traffic” to the Park. With regard to data collection, the questionnaire method including personal observation were employed to obtain information from the four communities that surround the Park, the Park officials and tourists who visited the facility from April to May, 2011. The results analysed revealed that turn out was comparatively low due to the remote location of the Park including poor accessibility and low income among Ghanaians. Tourism awareness among community members was found to be high. Tourists found the Park impressive in terms of its variety in wildlife and services rendered therein. It was discovered that the Park has a high tourism potential which can be harnessed to attract both domestic and international tourists and bring socio-economic benefits to Ghana. The paper suggests that improvements in road network to and in the Park and stiffer sanctions to curb poaching were major ways to enhance tourism/recreation in the Park and making it sustainable.

  14. FRACTIONAL BANKING

    OpenAIRE

    Maria Klimikova

    2010-01-01

    Understanding the reasons of the present financial problems lies In understanding the substance of fractional reserve banking. The substance of fractional banking is in lending more money than the bankers have. Banking of partial reserves is an alternative form which links deposit banking and credit banking. Fractional banking is causing many unfavorable economic impacts in the worldwide system, specifically an inflation.

  15. Fractional thermoelasticity

    CERN Document Server

    Povstenko, Yuriy

    2015-01-01

    This book is devoted to fractional thermoelasticity, i.e. thermoelasticity based on the heat conduction equation with differential operators of fractional order. Readers will discover how time-fractional differential operators describe memory effects and space-fractional differential operators deal with the long-range interaction. Fractional calculus, generalized Fourier law, axisymmetric and central symmetric problems and many relevant equations are featured in the book. The latest developments in the field are included and the reader is brought up to date with current research.  The book contains a large number of figures, to show the characteristic features of temperature and stress distributions and to represent the whole spectrum of order of fractional operators.  This work presents a picture of the state-of-the-art of fractional thermoelasticity and is suitable for specialists in applied mathematics, physics, geophysics, elasticity, thermoelasticity and engineering sciences. Corresponding sections of ...

  16. Fructose-driven glycolysis supports anoxia resistance in the naked mole-rat.

    Science.gov (United States)

    Park, Thomas J; Reznick, Jane; Peterson, Bethany L; Blass, Gregory; Omerbašić, Damir; Bennett, Nigel C; Kuich, P Henning J L; Zasada, Christin; Browe, Brigitte M; Hamann, Wiebke; Applegate, Daniel T; Radke, Michael H; Kosten, Tetiana; Lutermann, Heike; Gavaghan, Victoria; Eigenbrod, Ole; Bégay, Valérie; Amoroso, Vince G; Govind, Vidya; Minshall, Richard D; Smith, Ewan St J; Larson, John; Gotthardt, Michael; Kempa, Stefan; Lewin, Gary R

    2017-04-21

    The African naked mole-rat's ( Heterocephalus glaber ) social and subterranean lifestyle generates a hypoxic niche. Under experimental conditions, naked mole-rats tolerate hours of extreme hypoxia and survive 18 minutes of total oxygen deprivation (anoxia) without apparent injury. During anoxia, the naked mole-rat switches to anaerobic metabolism fueled by fructose, which is actively accumulated and metabolized to lactate in the brain. Global expression of the GLUT5 fructose transporter and high levels of ketohexokinase were identified as molecular signatures of fructose metabolism. Fructose-driven glycolytic respiration in naked mole-rat tissues avoids feedback inhibition of glycolysis via phosphofructokinase, supporting viability. The metabolic rewiring of glycolysis can circumvent the normally lethal effects of oxygen deprivation, a mechanism that could be harnessed to minimize hypoxic damage in human disease. Copyright © 2017, American Association for the Advancement of Science.

  17. Bio-oil fractionation and condensation

    Science.gov (United States)

    Brown, Robert C; Jones, Samuel T; Pollard, Anthony

    2013-07-02

    A method of fractionating bio-oil vapors which involves providing bio-oil vapors comprising bio-oil constituents is described. The bio-oil vapors are cooled in a first stage which comprises a condenser having passages for the bio-oil separated by a heat conducting wall from passages for a coolant. The coolant in the condenser of the first stage is maintained at a substantially constant temperature, set at a temperature in the range of 75 to 100.degree. C., to condense a first liquid fraction of liquefied bio-oil constituents in the condenser of the first stage. The first liquid fraction of liquified bio-oil constituents from the condenser in the first stage is collected. Also described are steps for subsequently recovering further liquid fractions of liquefied bio-oil constituents. Particular compositions of bio-oil condensation products are also described.

  18. Hypersensitivity to contact inhibition provides a clue to cancer resistance of naked mole-rat.

    Science.gov (United States)

    Seluanov, Andrei; Hine, Christopher; Azpurua, Jorge; Feigenson, Marina; Bozzella, Michael; Mao, Zhiyong; Catania, Kenneth C; Gorbunova, Vera

    2009-11-17

    The naked mole-rat is the longest living rodent with a maximum lifespan exceeding 28 years. In addition to its longevity, naked mole-rats have an extraordinary resistance to cancer as tumors have never been observed in these rodents. Furthermore, we show that a combination of activated Ras and SV40 LT fails to induce robust anchorage-independent growth in naked mole-rat cells, while it readily transforms mouse fibroblasts. The mechanisms responsible for the cancer resistance of naked mole-rats were unknown. Here we show that naked mole-rat fibroblasts display hypersensitivity to contact inhibition, a phenomenon we termed "early contact inhibition." Contact inhibition is a key anticancer mechanism that arrests cell division when cells reach a high density. In cell culture, naked mole-rat fibroblasts arrest at a much lower density than those from a mouse. We demonstrate that early contact inhibition requires the activity of p53 and pRb tumor suppressor pathways. Inactivation of both p53 and pRb attenuates early contact inhibition. Contact inhibition in human and mouse is triggered by the induction of p27(Kip1). In contrast, early contact inhibition in naked mole-rat is associated with the induction of p16(Ink4a). Furthermore, we show that the roles of p16(Ink4a) and p27(Kip1) in the control of contact inhibition became temporally separated in this species: the early contact inhibition is controlled by p16(Ink4a), and regular contact inhibition is controlled by p27(Kip1). We propose that the additional layer of protection conferred by two-tiered contact inhibition contributes to the remarkable tumor resistance of the naked mole-rat.

  19. The Naked Mole Rat Genome Resource : facilitating analyses of cancer and longevity-related adaptations

    OpenAIRE

    Keane, Michael; Craig, Thomas; Alfoldi, Jessica; Berlin, Aaron M; Johnson, Jeremy; Seluanov, Andrei; Gorbunova, Vera; Di Palma, Federica; Lindblad-Toh, Kerstin; Church, George M; de Magalhaes, Joao Pedro

    2014-01-01

    MOTIVATION: The naked mole rat (Heterocephalus glaber) is an exceptionally long-lived and cancer-resistant rodent native to East Africa. Although its genome was previously sequenced, here we report a new assembly sequenced by us with substantially higher N50 values for scaffolds and contigs. RESULTS: We analyzed the annotation of this new improved assembly and identified candidate genomic adaptations which may have contributed to the evolution of the naked mole rat's extraordinary traits, inc...

  20. Assessment of naked mole-rat distribution and threats in Eastern Ethiopia

    Directory of Open Access Journals (Sweden)

    Mengistu Wale

    2016-08-01

    Full Text Available Objective: To identify the distribution, threats and community attitudes towards naked molerat in Eastern Ethiopia. Methods: Data were collected through direct observation and interview and Chi-square at 95% confidence interval was used for significance test. Results: Naked mole-rat was identified in Fafan, City/Shinele, Eastern Hararghe Zone and Dire Dawa Administrative. The main threats of naked mole-rat identified were agricultural expansion, human killing and lack of awareness. From a total of 100 respondents, 92% of them considered naked mole-rat as pest as a result that 46% of them participated in direct killing. Literacy rate significantly affects the willingness to participate in the conservation of naked mole-rat (χ2 = 7.478, df = 1, P < 0.05. From a total of 26% respondents who did not show the willingness to participate in the conservation, 80.8% of them were illiterate. Conclusions: Naked mole-rat is fairly common in many of the study sites. However, rapid shift from nomadic life style to cultivation of crops and lacks of awareness were the main threats of naked mole-rat. Therefore, since there is no conservation action currently, further comprehensive study is required to design conservation plan for this species.

  1. High Autophagy in the Naked Mole Rat may Play a Significant Role in Maintaining Good Health

    Directory of Open Access Journals (Sweden)

    Shanmin Zhao

    2014-02-01

    Full Text Available Background/Aims: The maximum lifespan of the naked mole rat is over 28.3 years, which exceeds that of any other rodent species, suggesting that age-related changes in its body composition and functionality are either attenuated or delayed in this extraordinarily long-lived species. However, the mechanisms underlying the aging process in this species are poorly understood. In this study, we investigated whether long-lived naked mole rats display more autophagic activity than short-lived mice. Methods: Hepatic stellate cells isolated from naked mole rats were treated with 50 nM rapamycin or 20 mM 3-methyladenine (3-MA for 12 or 24 h. Expression of the autophagy marker proteins LC3-II and beclin 1 was measured with western blotting and immunohistochemistry. The induction of apoptosis was analyzed by flow cytometry. Results: Our results demonstrate that one-day-old naked mole rats have higher levels of autophagy than one-day-old short-lived C57BL/6 mice, and that both adult naked mole rats (eight months old and adult C57BL/6 mice (eight weeks old have high basal levels of autophagy, which may be an important mechanism inhibiting aging and reducing the risk of age-related diseases. Conclusion: Here, we report that autophagy facilitated the survival of hepatic stellate cells from the naked mole rat, and that treatment with 3-MA or rapamycin increased the ratio of apoptotic cells to normal hepatic stellate cells.

  2. Blunted neuronal calcium response to hypoxia in naked mole-rat hippocampus.

    Directory of Open Access Journals (Sweden)

    Bethany L Peterson

    Full Text Available Naked mole-rats are highly social and strictly subterranean rodents that live in large communal colonies in sealed and chronically oxygen-depleted burrows. Brain slices from naked mole-rats show extreme tolerance to hypoxia compared to slices from other mammals, as indicated by maintenance of synaptic transmission under more hypoxic conditions and three fold longer latency to anoxic depolarization. A key factor in determining whether or not the cellular response to hypoxia is reversible or leads to cell death may be the elevation of intracellular calcium concentration. In the present study, we used fluorescent imaging techniques to measure relative intracellular calcium changes in CA1 pyramidal cells of hippocampal slices during hypoxia. We found that calcium accumulation during hypoxia was significantly and substantially attenuated in slices from naked mole-rats compared to slices from laboratory mice. This was the case for both neonatal (postnatal day 6 and older (postnatal day 20 age groups. Furthermore, while both species demonstrated more calcium accumulation at older ages, the older naked mole-rats showed a smaller calcium accumulation response than even the younger mice. A blunted intracellular calcium response to hypoxia may contribute to the extreme hypoxia tolerance of naked mole-rat neurons. The results are discussed in terms of a general hypothesis that a very prolonged or arrested developmental process may allow adult naked mole-rat brain to retain the hypoxia tolerance normally only seen in neonatal mammals.

  3. The naked mole-rat response to oxidative stress: just deal with it.

    Science.gov (United States)

    Lewis, Kaitlyn N; Andziak, Blazej; Yang, Ting; Buffenstein, Rochelle

    2013-10-20

    The oxidative stress theory of aging has been the most widely accepted theory of aging providing insights into why we age and die for over 50 years, despite mounting evidence from a multitude of species indicating that there is no direct relationship between reactive oxygen species (ROS) and longevity. Here we explore how different species, including the longest lived rodent, the naked mole-rat, have defied the most predominant aging theory. In the case of extremely long-lived naked mole-rat, levels of ROS production are found to be similar to mice, antioxidant defenses unexceptional, and even under constitutive conditions, naked mole-rats combine a pro-oxidant intracellular milieu with high, steady state levels of oxidative damage. Clearly, naked mole-rats can tolerate this level of oxidative stress and must have mechanisms in place to prevent its translation into potentially lethal diseases. In addition to the naked mole-rat, other species from across the phylogenetic spectrum and even certain mouse strains do not support this theory. Moreover, overexpressing or knocking down antioxidant levels alters levels of oxidative damage and even cancer incidence, but does not modulate lifespan. Perhaps, it is not oxidative stress that modulates healthspan and longevity, but other cytoprotective mechanisms that allow animals to deal with high levels of oxidative damage and stress, and nevertheless live long, relatively healthy lifespans. Studying these mechanisms in uniquely long-lived species, like the naked mole-rat, may help us tease out the key contributors to aging and longevity.

  4. Blunted neuronal calcium response to hypoxia in naked mole-rat hippocampus.

    Science.gov (United States)

    Peterson, Bethany L; Larson, John; Buffenstein, Rochelle; Park, Thomas J; Fall, Christopher P

    2012-01-01

    Naked mole-rats are highly social and strictly subterranean rodents that live in large communal colonies in sealed and chronically oxygen-depleted burrows. Brain slices from naked mole-rats show extreme tolerance to hypoxia compared to slices from other mammals, as indicated by maintenance of synaptic transmission under more hypoxic conditions and three fold longer latency to anoxic depolarization. A key factor in determining whether or not the cellular response to hypoxia is reversible or leads to cell death may be the elevation of intracellular calcium concentration. In the present study, we used fluorescent imaging techniques to measure relative intracellular calcium changes in CA1 pyramidal cells of hippocampal slices during hypoxia. We found that calcium accumulation during hypoxia was significantly and substantially attenuated in slices from naked mole-rats compared to slices from laboratory mice. This was the case for both neonatal (postnatal day 6) and older (postnatal day 20) age groups. Furthermore, while both species demonstrated more calcium accumulation at older ages, the older naked mole-rats showed a smaller calcium accumulation response than even the younger mice. A blunted intracellular calcium response to hypoxia may contribute to the extreme hypoxia tolerance of naked mole-rat neurons. The results are discussed in terms of a general hypothesis that a very prolonged or arrested developmental process may allow adult naked mole-rat brain to retain the hypoxia tolerance normally only seen in neonatal mammals.

  5. Management of pest mole crickets in Florida and Puerto Rico with a nematode and parasitic wasp

    International Nuclear Information System (INIS)

    Leppla, N.C.; Frank, J.H.; Adjei, M.B.; Vicente, N.E.

    2007-01-01

    Non-indigenous invasive mole crickets, Scapteriscus vicinus Scudder (Orthoptera: Gryllotalpidae) in Florida and S. didactylus (Latreille) (the 'changa') in Puerto Rico, are being managed with an entomopathogenic nematode, Steinernema scapterisci (Nguyen and Smart) (Rhabditida: Steinernematidae), and a parasitic wasp, Larra bicolor L. (Hymenoptera: Sphecidae). Pest mole cricket populations have declined by 95% in north central Florida since these specialist natural enemies were released and established in the 1980s. Commercial production of the nematode was initiated, nearly 70 billion were applied in 34 Florida counties, and their establishment, spread, and impact on mole crickets were monitored. The infected mole crickets dispersed the nematode rapidly, so that within 6 months these parasites were present in most of the insects trapped in experimental pastures. Three years later, mole cricket populations were reduced to acceptable levels and the bahiagrass had recovered. The nematode was released for the first time in Puerto Rico during 2001 and has persisted; the wasp was introduced in the late 1930s. The geographical distribution of the wasp is being expanded in Florida and Puerto Rico by planting plots of Spermacoce verticillata (L.), a wildflower indigenous to Puerto Rico and widely distributed in southern Florida. Pastures, sod farms, golf courses, landscapes, and vegetable farms in Florida and Puerto Rico are benefiting from biological control of invasive mole crickets. (author) [es

  6. Fuel vapor pressure (FVAPRS)

    International Nuclear Information System (INIS)

    Mason, R.E.

    1979-04-01

    A subcode (FVAPRS) is described which calculates fuel vapor pressure. This subcode was developed as part of the fuel rod behavior modeling task performed at EG and G Idaho, Inc. The fuel vapor pressure subcode (FVAPRS), is presented and a discussion of literature data, steady state and transient fuel vapor pressure equations and estimates of the standard error of estimate to be expected with the FVAPRS subcode are included

  7. Vapor-Liquid Equilibrium Measurements and Modeling of the Propyl Mercaptan plus Methane plus Water System

    DEFF Research Database (Denmark)

    Awan, Javeed; Thomsen, Kaj; Coquelet, Christophe

    2010-01-01

    In this work, vapor−liquid equilibrium (VLE) measurements of propyl mercaptan (PM) in pure water were performed at three different temperatures, (303, 323, and 365) K, with a pressure variation from (1 to 8) MPa. The total system pressure was maintained by CH4. The inlet mole fraction of propyl...

  8. A technique to depress desflurane vapor pressure.

    Science.gov (United States)

    Brosnan, Robert J; Pypendop, Bruno H

    2006-09-01

    To determine whether the vapor pressure of desflurane could be decreased by using a solvent to reduce the anesthetic molar fraction in a solution (Raoult's Law). We hypothesized that such an anesthetic mixture could produce anesthesia using a nonprecision vaporizer instead of an agent-specific, electronically controlled, temperature and pressure compensated vaporizer currently required for desflurane administration. One healthy adult female dog. Propylene glycol was used as a solvent for desflurane, and the physical characteristics of this mixture were evaluated at various molar concentrations and temperatures. Using a circle system with a breathing bag attached at the patient end and a mechanical ventilator to simulate respiration, an in-circuit, nonprecision vaporizer containing 40% desflurane and 60% propylene glycol achieved an 11.5% +/- 1.0% circuit desflurane concentration with a 5.2 +/- 0.4 (0 = off, 10 = maximum) vaporizer setting. This experiment was repeated with a dog attached to the breathing circuit under spontaneous ventilation with a fresh gas flow of 0.5 L minute(-1). Anesthesia was maintained for over 2 hours at a mean vaporizer setting of 6.2 +/- 0.4, yielding mean inspired and end-tidal desflurane concentrations of 8.7% +/- 0.5% and 7.9% +/- 0.7%, respectively. Rather than alter physical properties of vaporizers to suit a particular anesthetic agent, this study demonstrates that it is also possible to alter physical properties of anesthetic agents to suit a particular vaporizer. However, propylene glycol may not prove an ideal solvent for desflurane because of its instability in solution and substantial-positive deviation from Raoult's Law.

  9. Molecular dynamics study of the vaporization of an ionic drop.

    Science.gov (United States)

    Galamba, N

    2010-09-28

    The melting of a microcrystal in vacuum and subsequent vaporization of a drop of NaCl were studied through molecular dynamics simulations with the Born-Mayer-Huggins-Tosi-Fumi rigid-ion effective potential. The vaporization was studied for a single isochor at increasing temperatures until the drop completely vaporized, and gaseous NaCl formed. Examination of the vapor composition shows that the vapor of the ionic drop and gaseous NaCl are composed of neutral species, the most abundant of which, ranging from simple NaCl monomers (ion pairs) to nonlinear polymers, (Na(n)Cl(n))(n=2-4). The enthalpies of sublimation, vaporization, and dissociation of the different vapor species are found to be in reasonable agreement with available experimental data. The decrease of the enthalpy of vaporization of the vapor species, with the radius of the drop decrease, accounts for a larger fraction of trimers and tetramers than that inferred from experiments. Further, the rhombic dimer is significantly more abundant than its linear isomer although the latter increases with the temperature. The present results suggest that both trimers and linear dimers may be important to explain the vapor pressure of molten NaCl at temperatures above 1500 K.

  10. Molecular dynamics study of the vaporization of an ionic drop

    Science.gov (United States)

    Galamba, N.

    2010-09-01

    The melting of a microcrystal in vacuum and subsequent vaporization of a drop of NaCl were studied through molecular dynamics simulations with the Born-Mayer-Huggins-Tosi-Fumi rigid-ion effective potential. The vaporization was studied for a single isochor at increasing temperatures until the drop completely vaporized, and gaseous NaCl formed. Examination of the vapor composition shows that the vapor of the ionic drop and gaseous NaCl are composed of neutral species, the most abundant of which, ranging from simple NaCl monomers (ion pairs) to nonlinear polymers, (NanCln)n=2-4. The enthalpies of sublimation, vaporization, and dissociation of the different vapor species are found to be in reasonable agreement with available experimental data. The decrease of the enthalpy of vaporization of the vapor species, with the radius of the drop decrease, accounts for a larger fraction of trimers and tetramers than that inferred from experiments. Further, the rhombic dimer is significantly more abundant than its linear isomer although the latter increases with the temperature. The present results suggest that both trimers and linear dimers may be important to explain the vapor pressure of molten NaCl at temperatures above 1500 K.

  11. Physical model for vaporization

    OpenAIRE

    Garai, Jozsef

    2006-01-01

    Based on two assumptions, the surface layer is flexible, and the internal energy of the latent heat of vaporization is completely utilized by the atoms for overcoming on the surface resistance of the liquid, the enthalpy of vaporization was calculated for 45 elements. The theoretical values were tested against experiments with positive result.

  12. Petroleum Vapor - Field Technical

    Science.gov (United States)

    The screening approach being developed by EPA OUST to evaluate petroleum vapor intrusion (PVI) requires information that has not be routinely collected in the past at vapor intrusion sites. What is the best way to collect this data? What are the relevant data quality issues and ...

  13. Volatilization of multicomponent mixtures in soil vapor extraction applications

    International Nuclear Information System (INIS)

    Bass, D.H.

    1995-01-01

    In soil vapor extraction (SVE) applications involving multicomponent mixtures, prediction of mass removal by volatilization as a function remediation extent is required to estimate remediation time and to size offgas treatment equipment. SVE is a commonly used remediation technology which volatilizes and enhances aerobic biodegradation of contamination adsorbed to vadose zone soils. SVE is often applied at sites contaminated with petroleum products, which are usually mixtures of many different compounds with vapor pressures spanning several orders of magnitude. The most volatile components are removed first, so the vapor pressure of the remaining contaminant continually decreases over the course of the remediation. A method for assessing how vapor pressure, and hence the rate of volatilization, of a multicomponent mixture changes over the course of a vapor extraction remedy has been developed. Each component is listed, alone, with its mass fraction in the mixture, in decreasing order of pure component vapor pressure (where component analyses are unavailable, model compounds can be used), For most petroleum distillates, the vapor pressure for each component plotted against the cumulative mass fraction of the component in the mixture on semilog coordinates will produce a straight line with a high correlation coefficient. This regression can be integrated to produce an expression for vapor pressure of the overall mixture as a function of extent or remediation

  14. Experimental determination of the (vapor + liquid) equilibrium data of binary mixtures of fatty acids by differential scanning calorimetry

    International Nuclear Information System (INIS)

    Matricarde Falleiro, Rafael M.; Meirelles, Antonio J.A.; Kraehenbuehl, Maria A.

    2010-01-01

    (Vapor + liquid) equilibrium (VLE) data for three binary mixtures of saturated fatty acids were obtained by differential scanning calorimetry (DSC). However, changes in the calorimeter pressure cell and the use of hermetic pans with holes (φ = 250 mm) in the lids were necessary to make it possible to apply this analytical technique, obtaining accurate results with smaller samples and shorter operational times. The systems evaluated in this study were: myristic acid (C 14:0 ) + palmitic acid (C 16:0 ), myristic acid (C 14:0 ) + stearic acid (C 18:0 ), and palmitic acid (C 16:0 ) + stearic acid (C 18:0 ), all measured at 50 mm Hg and with mole fractions between 0.0 and 1.0 in relation to the most volatile component of each diagram. The fugacity coefficients for the components in the vapor phase were calculated using the Hayden and O'Connell method [J.G. Hayden, J.P. O'Connell, Ind. Eng. Chem. Process Design Develop. 14 (3) (1975) 209-216] and the activity coefficients for the liquid phase were correlated with the traditional g E models (NRTL [H. Renon, J.M. Prausnitz, Aiche J. 14 (1968) 135-144], UNIQUAC [D.S. Abrams, J.M. Prausnitz, Aiche J. 21 (1975) 116-128], and Wilson [J.M. Prausnitz, N.L. Linchtenthaler, E.G. Azevedo, Molecular Thermodynamics of Fluid-phase Equilibria, River-Prentice Hall, Upper Saddle, 1999]). The sets of parameters were then compared in order to determine which adjustments best represented the VLE.

  15. Incidence and review of hydatidiform mole; chorioadenoma, destruens and chorio carcinoma in Mirza Kochek Khan Hospita

    Directory of Open Access Journals (Sweden)

    Ghaffari V

    1995-04-01

    Full Text Available Initial management, incidence and review of hydatidiform mole, chorioadenoma and destruens and chorio carcinoma in Mirza Kochek khan hospital department of ob.gyn and gynecology oncology of women's hospital Tehran-Iran school of medicin from September 1985 to March 1990, 209 patients received primary management for hydatidiform mole at oncology department of Mirza Kochek Khan hospital medical school of Tehran Iran. All of these women HAD complete record available for analysis, of these, 167 women bydatidiform mole, 12 patients chorioadenoma-destruens 30 patients chorio carcinoma a survey was made of factors likely to provide an important clinical perspective patient aye and the status of pregnancy were noted. 41 patient only sharp curettage and 55 patients suction curettage to remove the hydatidiform mole. 97 patient require chemo terapy, suction curettage of the uterus is clearly the best means of management in the most cases their eyperince documents that hydatidiform mole is an high risk pregnancy that requires prompt and in tensive management.

  16. Central visual system of the naked mole-rat (Heterocephalus glaber).

    Science.gov (United States)

    Crish, Samuel D; Dengler-Crish, Christine M; Catania, Kenneth C

    2006-02-01

    Naked mole-rats are fossorial rodents native to eastern Africa that spend their lives in extensive subterranean burrows where visual cues are poor. Not surprisingly, they have a degenerated eye and optic nerve, suggesting they have poor visual abilities. However, little is known about their central visual system. To investigate the organization of their central visual system, we injected a neuronal tracer into the eyes of naked mole-rats and mice to compare the neural structures mediating vision. We found that the superior colliculus and lateral geniculate nucleus were severely atrophied in the naked mole-rat. The olivary pretectal nucleus was reduced but still retained its characteristic morphology, possibly indicating a role in light detection. In addition, the suprachiasmatic nucleus is well innervated and resembles the same structure in other rodents. The naked mole-rat appears to have selectively lost structures that mediate form vision while retaining structures needed for minimal entrainment of circadian rhythms. Similar results have been reported for other mole-rat species. Taken together, these data suggest that light detection may still play an important role in the lives of these "blind" animals: most likely for circadian entrainment or setting seasonal rhythms.

  17. Unraveling the message: insights into comparative genomics of the naked mole-rat.

    Science.gov (United States)

    Lewis, Kaitlyn N; Soifer, Ilya; Melamud, Eugene; Roy, Margaret; McIsaac, R Scott; Hibbs, Matthew; Buffenstein, Rochelle

    2016-08-01

    Animals have evolved to survive, and even thrive, in different environments. Genetic adaptations may have indirectly created phenotypes that also resulted in a longer lifespan. One example of this phenomenon is the preternaturally long-lived naked mole-rat. This strictly subterranean rodent tolerates hypoxia, hypercapnia, and soil-based toxins. Naked mole-rats also exhibit pronounced resistance to cancer and an attenuated decline of many physiological characteristics that often decline as mammals age. Elucidating mechanisms that give rise to their unique phenotypes will lead to better understanding of subterranean ecophysiology and biology of aging. Comparative genomics could be a useful tool in this regard. Since the publication of a naked mole-rat genome assembly in 2011, analyses of genomic and transcriptomic data have enabled a clearer understanding of mole-rat evolutionary history and suggested molecular pathways (e.g., NRF2-signaling activation and DNA damage repair mechanisms) that may explain the extraordinarily longevity and unique health traits of this species. However, careful scrutiny and re-analysis suggest that some identified features result from incorrect or imprecise annotation and assembly of the naked mole-rat genome: in addition, some of these conclusions (e.g., genes involved in cancer resistance and hairlessness) are rejected when the analysis includes additional, more closely related species. We describe how the combination of better study design, improved genomic sequencing techniques, and new bioinformatic and data analytical tools will improve comparative genomics and ultimately bridge the gap between traditional model and nonmodel organisms.

  18. Fractional charges

    International Nuclear Information System (INIS)

    Saminadayar, L.

    2001-01-01

    20 years ago fractional charges were imagined to explain values of conductivity in some materials. Recent experiments have proved the existence of charges whose value is the third of the electron charge. This article presents the experimental facts that have led theorists to predict the existence of fractional charges from the motion of quasi-particles in a linear chain of poly-acetylene to the quantum Hall effect. According to the latest theories, fractional charges are neither bosons nor fermions but anyons, they are submitted to an exclusive principle that is less stringent than that for fermions. (A.C.)

  19. Prophylactic chemotherapy for hydatidiform mole to prevent gestational trophoblastic neoplasia.

    Science.gov (United States)

    Wang, Qiuyi; Fu, Jing; Hu, Lina; Fang, Fang; Xie, Lingxia; Chen, Hengxi; He, Fan; Wu, Taixiang; Lawrie, Theresa A

    2017-09-11

    This is an update of the original Cochrane Review published in Cochrane Library, Issue 10, 2012.Hydatidiform mole (HM), also called a molar pregnancy, is characterised by an overgrowth of foetal chorionic tissue within the uterus. HMs may be partial (PM) or complete (CM) depending on their gross appearance, histopathology and karyotype. PMs usually have a triploid karyotype, derived from maternal and paternal origins, whereas CMs are diploid and have paternal origins only. Most women with HM can be cured by evacuation of retained products of conception (ERPC) and their fertility preserved. However, in some women the growth persists and develops into gestational trophoblastic neoplasia (GTN), a malignant form of the disease that requires treatment with chemotherapy. CMs have a higher rate of malignant transformation than PMs. It may be possible to reduce the risk of GTN in women with HM by administering prophylactic chemotherapy (P-Chem). However, P-Chem given before or after evacuation of HM to prevent malignant sequelae remains controversial, as the risks and benefits of this practice are unclear. To evaluate the effectiveness and safety of P-Chem to prevent GTN in women with a molar pregnancy. To investigate whether any subgroup of women with HM may benefit more from P-Chem than others. For the original review we performed electronic searches in the Cochrane Gynaecological Cancer Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL, Issue 2, 2012), MEDLINE (1946 to February week 4, 2012) and Embase (1980 to 2012, week 9). We developed the search strategy using free text and MeSH. For this update we searched the Cochrane Central Register of Controlled Trials (CENTRAL, Issue 5, 2017), MEDLINE (February 2012 to June week 1, 2017) and Embase (February 2012 to 2017, week 23). We also handsearched reference lists of relevant literature to identify additional studies and searched trial registries. We included randomised controlled trials

  20. Piezoelectric trace vapor calibrator

    International Nuclear Information System (INIS)

    Verkouteren, R. Michael; Gillen, Greg; Taylor, David W.

    2006-01-01

    The design and performance of a vapor generator for calibration and testing of trace chemical sensors are described. The device utilizes piezoelectric ink-jet nozzles to dispense and vaporize precisely known amounts of analyte solutions as monodisperse droplets onto a hot ceramic surface, where the generated vapors are mixed with air before exiting the device. Injected droplets are monitored by microscope with strobed illumination, and the reproducibility of droplet volumes is optimized by adjustment of piezoelectric wave form parameters. Complete vaporization of the droplets occurs only across a 10 deg. C window within the transition boiling regime of the solvent, and the minimum and maximum rates of trace analyte that may be injected and evaporated are determined by thermodynamic principles and empirical observations of droplet formation and stability. By varying solution concentrations, droplet injection rates, air flow, and the number of active nozzles, the system is designed to deliver--on demand--continuous vapor concentrations across more than six orders of magnitude (nominally 290 fg/l to 1.05 μg/l). Vapor pulses containing femtogram to microgram quantities of analyte may also be generated. Calibrated ranges of three explosive vapors at ng/l levels were generated by the device and directly measured by ion mobility spectrometry (IMS). These data demonstrate expected linear trends within the limited working range of the IMS detector and also exhibit subtle nonlinear behavior from the IMS measurement process

  1. Fractional fermions

    International Nuclear Information System (INIS)

    Jackiw, R.; Massachusetts Inst. of Tech., Cambridge; Massachusetts Inst. of Tech., Cambridge

    1984-01-01

    The theory of fermion fractionization due to topologically generated fermion ground states is presented. Applications to one-dimensional conductors, to the MIT bag, and to the Hall effect are reviewed. (author)

  2. Uranium/water vapor reactions in gaseous atmospheres

    International Nuclear Information System (INIS)

    Jackson, R.L.; Condon, J.B.; Steckel, L.M.

    1977-07-01

    Experiments have been performed to determine the effect of varying humidities, gaseous atmospheres, and temperatures on the uranium/water vapor reaction. A balance, which allowed continuous in-system weighings, was used to determine the rates of the uranium/water vapor reactions at water vapor pressures of 383, 1586, and 2853 Pa and at temperatures of 80, 100, and 150 0 C in atmospheres of hydrogen, argon, or argon/oxygen mixtures. Based on rate data, the reactions were characterized as hydriding or nonhydriding. Hydriding reactions were found to be preferred in moist hydrogen systems at the higher temperatures and the lower humidities. The presence of hydrogen in hydriding systems was found to initially inhibit the reaction, but causes an acceleration of the rate in the final stages. In general, reaction rates of hydriding systems approached the hydriding rates calculated and observed in dry hydrogen. Hydriding and nonhydriding reaction rates showed a positive correlation to temperature and water vapor pressure. Final reaction rates in moist argon/oxygen mixtures of 1.93, 4.57, and 9.08 mole percent oxygen were greater than the rates observed in moist hydrogen or argon. Final reaction rates were negatively correlated to the oxygen concentration

  3. Improvements to vapor generators

    International Nuclear Information System (INIS)

    Keller, Arthur; Monroe, Neil.

    1976-01-01

    A supporting system is proposed for vapor generators of the 'supported' type. Said supporting system is intended to compensate the disparities of thermal expansion due to the differences in the vertical dimensions of the tubes in the walls of the combustion chamber and their collectors compared to that of the balloon tanks and the connecting tube clusters of vaporization, the first one being longer than the second ones. Said system makes it possible to build said combustion chamber higher than the balloon tanks and the tube clusters of vaporization. The capacity of steam production is thus enhanced [fr

  4. Evaluation of the MoleMateTM training program for assessment of suspicious pigmented lesions in primary care

    Directory of Open Access Journals (Sweden)

    Annabel Wood

    2008-05-01

    Conclusion The MoleMateTM training program is a potentially effective and acceptable informatics tool to teach practitioners to recognise the features of SPLs identified by the MoleMateTM system. It will be used as part of the intervention in a randomised controlled trial to compare the diagnostic accuracy and appropriate referral rates of practitioners using the MoleMateTM system with best practice in primary care.

  5. Role of immunoexpression of cyclin D1, D3, retinoblastoma (Rb mutant and clinical risk factors on complete mole as risk factors of persistent mole

    Directory of Open Access Journals (Sweden)

    Yudi M Hidayat

    2015-10-01

    Full Text Available Introduction: Changes in complete hydatidiform mole (CHM that become persistent are difficult to handle because the malignant pathogenesis of CHM is still unclear. The growth of abnormal cells in CHM is thought to be caused by cell cycle abnormalities. Some components that play a role in this phase include cyclin D and retinoblastoma (Rb. The aim of our study was to determine the role of clinical risk factors, as well as cyclin D1, cyclin D3 and Rb-protein, in the occurrence of persistent moles. Materials and Method: This study involves 68 CHM cases at Dr. Hasan Sadikin Hospital from 2007–2011. The protein expression of cyclin D1, cyclin D3, and Rb were determined by immunohistochemistry. The results were analyzed by comparing the two groups of CHM that became persistent to those that returned to normal, as determined by a Mochizuki regression curve assessment. Results: 20 cases (29% of CHM became persistent and that 48 cases (71% returned to normal. Significant clinical variables were age (p 0.05. Conclusion: There is a strong relationship between clinical risk factors of age, excessive proliferation histopathology, serum βhCG levels ≥100,000 mU/mL, cyclin D1 and Rb mutations with the incidence of persistent moles after the evacuation of the CHM. We proposed a model to predict the risks of persistent moles with a cut-off point of 2.384, which can be used as a reference for patients with CHM.

  6. A Mole for Warm Magnetic and Optical Measurements of LHC Dipoles

    CERN Document Server

    Bottura, L; Deferne, G; Glöckner, C; Jansen, H; Köster, A; Legrand, P; Rijllart, A; Sievers, P

    2000-01-01

    A new rotating coil probe (a mole) has been developed for the simultaneous measurement of the magnetic field and magnetic axis of warm superconducting LHC dipoles and associated corrector windings. The mole houses a radial rotating coil and travels inside the magnet aperture by means of an externally driven two-way traction belt. The coil is rotated by an on-board piezo motor, being tested in view of future devices for cold measurements as the only type of motor compatible with strong magnetic fields. A virtual light spot is generated in the coil center by a LED source. The position of this light spot is measured from the outside by a system including a telescope, a CCD camera and a DSP. Jigs on reference granite tables are used to transfer the optical measurements to the magnet fiducials. We describe here the main characteristics and performance of the mole

  7. The molecular basis of acid insensitivity in the African naked mole-rat.

    Science.gov (United States)

    Smith, Ewan St John; Omerbašić, Damir; Lechner, Stefan G; Anirudhan, Gireesh; Lapatsina, Liudmila; Lewin, Gary R

    2011-12-16

    Acid evokes pain by exciting nociceptors; the acid sensors are proton-gated ion channels that depolarize neurons. The naked mole-rat (Heterocephalus glaber) is exceptional in its acid insensitivity, but acid sensors (acid-sensing ion channels and the transient receptor potential vanilloid-1 ion channel) in naked mole-rat nociceptors are similar to those in other vertebrates. Acid inhibition of voltage-gated sodium currents is more profound in naked mole-rat nociceptors than in mouse nociceptors, however, which effectively prevents acid-induced action potential initiation. We describe a species-specific variant of the nociceptor sodium channel Na(V)1.7, which is potently blocked by protons and can account for acid insensitivity in this species. Thus, evolutionary pressure has selected for an Na(V)1.7 gene variant that tips the balance from proton-induced excitation to inhibition of action potential initiation to abolish acid nociception.

  8. Extended longevity of reproductives appears to be common in Fukomys mole-rats (Rodentia, Bathyergidae.

    Directory of Open Access Journals (Sweden)

    Philip Dammann

    Full Text Available African mole-rats (Bathyergidae, Rodentia contain several social, cooperatively breeding species with low extrinsic mortality and unusually high longevity. All social bathyergids live in multigenerational families where reproduction is skewed towards a few breeding individuals. Most of their offspring remain as reproductively inactive "helpers" in their natal families, often for several years. This "reproductive subdivision" of mole-rat societies might be of interest for ageing research, as in at least one social bathyergid (Ansell's mole-rats Fukomys anselli, breeders have been shown to age significantly slower than non-breeders. These animals thus provide excellent conditions for studying the epigenetics of senescence by comparing divergent longevities within the same genotypes without the inescapable short-comings of inter-species comparisons. It has been claimed that many if not all social mole-rat species may have evolved similar ageing patterns, too. However, this remains unclear on account of the scarcity of reliable datasets on the subject. We therefore analyzed a 20-year breeding record of Giant mole-rats Fukomys mechowii, another social bathyergid species. We found that breeders indeed lived significantly longer than helpers (ca. 1.5-2.2fold depending on the sex, irrespective of social rank or other potentially confounding factors. Considering the phylogenetic positions of F. mechowii and F. anselli and unpublished data on a third Fukomys-species (F. damarensis showing essentially the same pattern, it seems probable that the reversal of the classic trade-off between somatic maintenance and sexual reproduction is characteristic of the whole genus and hence of the vast majority of social mole-rats.

  9. Stress Resistance in the Naked Mole-Rat: The Bare Essentials – A Mini-Review

    Science.gov (United States)

    Lewis, Kaitlyn N.; Mele, James; Hornsby, Peter J.; Buffenstein, Rochelle

    2012-01-01

    Background Studies comparing similar-sized species with disparate longevity may elucidate novel mechanisms that abrogate aging and prolong good health. We focus on the longest living rodent, the naked mole-rat. This mouse-sized mammal lives ∼8 times longer than do mice and, despite high levels of oxidative damage evident at a young age, it is not only very resistant to spontaneous neoplasia but also shows minimal decline in age-associated physiological traits. Objectives We assess the current status of stress resistance and longevity, focusing in particular on the molecular and cellular responses to cytotoxins and other stressors between the short-lived laboratory mouse and the naked mole-rat. Results Like other experimental animal models of lifespan extension, naked mole-rat fibroblasts are extremely tolerant of a broad spectrum of cytotoxins including heat, heavy metals, DNA-damaging agents and xenobiotics, showing LD50 values between 2- and 20-fold greater than those of fibroblasts of shorter-lived mice. Our new data reveal that naked mole-rat fibroblasts stop proliferating even at low doses of toxin whereas those mouse fibroblasts that survive treatment rapidly re-enter the cell cycle and may proliferate with DNA damage. Naked mole-rat fibroblasts also show significantly higher constitutive levels of both p53 and Nrf2 protein levels and activity, and this increases even further in response to toxins. Conclusion Enhanced cell signaling via p53 and Nrf2 protects cells against proliferating with damage, augments clearance of damaged proteins and organelles and facilitates the maintenance of both genomic and protein integrity. These pathways collectively regulate a myriad of mechanisms which may contribute to the attenuated aging profile and sustained healthspan of the naked mole-rat. Understanding how these are regulated may be also integral to sustaining positive human healthspan well into old age and may elucidate novel therapeutics for delaying the onset and

  10. Stress resistance in the naked mole-rat: the bare essentials - a mini-review.

    Science.gov (United States)

    Lewis, Kaitlyn N; Mele, James; Hornsby, Peter J; Buffenstein, Rochelle

    2012-01-01

    Studies comparing similar-sized species with disparate longevity may elucidate novel mechanisms that abrogate aging and prolong good health. We focus on the longest living rodent, the naked mole-rat. This mouse-sized mammal lives ~8 times longer than do mice and, despite high levels of oxidative damage evident at a young age, it is not only very resistant to spontaneous neoplasia but also shows minimal decline in age-associated physiological traits. We assess the current status of stress resistance and longevity, focusing in particular on the molecular and cellular responses to cytotoxins and other stressors between the short-lived laboratory mouse and the naked mole-rat. Like other experimental animal models of lifespan extension, naked mole-rat fibroblasts are extremely tolerant of a broad spectrum of cytotoxins including heat, heavy metals, DNA-damaging agents and xenobiotics, showing LD(50) values between 2- and 20-fold greater than those of fibroblasts of shorter-lived mice. Our new data reveal that naked mole-rat fibroblasts stop proliferating even at low doses of toxin whereas those mouse fibroblasts that survive treatment rapidly re-enter the cell cycle and may proliferate with DNA damage. Naked mole-rat fibroblasts also show significantly higher constitutive levels of both p53 and Nrf2 protein levels and activity, and this increases even further in response to toxins. Enhanced cell signaling via p53 and Nrf2 protects cells against proliferating with damage, augments clearance of damaged proteins and organelles and facilitates the maintenance of both genomic and protein integrity. These pathways collectively regulate a myriad of mechanisms which may contribute to the attenuated aging profile and sustained healthspan of the naked mole-rat. Understanding how these are regulated may be also integral to sustaining positive human healthspan well into old age and may elucidate novel therapeutics for delaying the onset and progression of physiological declines

  11. Gasoline Reid Vapor Pressure

    Science.gov (United States)

    EPA regulates the vapor pressure of gasoline sold at retail stations during the summer ozone season to reduce evaporative emissions from gasoline that contribute to ground-level ozone and diminish the effects of ozone-related health problems.

  12. An approach for characterization and lumping of plus fractions of heavy oil

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, I.; Hamouda, A.A. [Stavanger Univ., Stavanger (Norway)

    2008-10-15

    The constituents of hydrocarbons can be classified as either well-defined components or undefined petroleum fractions. This paper presented a newly developed method for characterizing plus fractions of heavy oil, which is particularly important for fluids with high molecular weight and high density. Characterization of plus fractions typically consists of 3 parts, notably splitting the fraction into a certain number of components groups called single carbon number (SCN); estimating the physico-chemical properties of the SCN; and lumping the generated SCN. SCN groups contain hundreds of isomers/components with the same number of carbon atoms. A unique molecular weight cannot be assigned for each SCN group because of the uncertainty of the isomers/components present. Therefore, this work focused on finding a new approach to characterize the undetermined fraction by first splitting the carbon number fraction into a representative number of SCN and then calculating their mole fraction and molecular weight. The method was based on the relationships between three parameter gamma distribution (TPG), experimental mole fraction, molecular weight and SCN data obtained from literature and industry. The method was applied to 5 different heavy oil sample fluids which all showed a left skewed distribution of the mole fraction as a function of carbon number. The predicted molecular weight was found to be close to the generalized molecular weight associated with carbon number, but it differed from one sample to another. 19 refs., 11 tabs., 15 figs.

  13. Twin pregnancy with both complete hydatiform mole and coexistent alive fetus: Case report

    Directory of Open Access Journals (Sweden)

    Achour Radhouane

    2015-12-01

    Full Text Available Twin pregnancy consisting of a complete hydatidiform mole coexisting with a live fetus is a rare condition with an incidence of 1 in 22000 to 1 in 100000 pregnancies. Clinical information is limited and management is difficult due to the risk of pregnancy complications such as fetal death, vaginal bleeding, preeclampsia, hyperthyroidism, and the risk of persistent gestational trophoblastic disease. Thus, the report described about the change of size and implantation site of the molar mass coexisting with a live fetus is rare especially about sonographic findings such as echo patterns. Recently we experienced a case of complete hydatidiform mole with a healthy infant delivered at term.

  14. Big insights from little animals: allosteric modulation and thermal sensitivity of shrew and mole hemoglobins

    DEFF Research Database (Denmark)

    Campbell, K.L.; Weber, Roy E.

    2007-01-01

    Mass-specific metabolic rate varies inversely with size, while pulmonary transit time, muscle O2 storage capacity, and the ability to exploit anaerobic metabolism vary directly with this variable. Thus, small mammals must exploit a suite of morphological and physiological adjustments to supply...... and moles. Despite these constraints, several shrew (and mole) species flourish at elevations exceeding 4500 m (where atmospheric PO2 is ... operating near their upper limits, what if any additional functional properties of the Hb of these species make these achievements possible? Our findings suggest that changes in the intrinsic O2-affinity of the Hb moiety (rather than phosphate sensitivity) underlie transitions to and from hypoxic...

  15. DSMC simulations of vapor transport toward development of the lithium vapor box divertor concept

    Science.gov (United States)

    Jagoe, Christopher; Schwartz, Jacob; Goldston, Robert

    2016-10-01

    The lithium vapor divertor box concept attempts to achieve volumetric dissipation of the high heat efflux from a fusion power system. The vapor extracts the heat of the incoming plasma by ionization and radiation, while remaining localized in the vapor box due to differential pumping based on rapid condensation. Preliminary calculations with lithium vapor at densities appropriate for an NSTX-U-scale machine give Knudsen numbers between 0.01 and 1, outside both the range of continuum fluid dynamics and of collisionless Monte Carlo. The direct-simulation Monte Carlo (DSMC) method, however, can simulate rarefied gas flows in this regime. Using the solver contained in the OpenFOAM package, pressure-driven flows of water vapor will be analyzed. The use of water vapor in the relevant range of Knudsen number allows for a flexible similarity experiment to verify the reliability of the code before moving to tests with lithium. The simulation geometry consists of chains of boxes on a temperature gradient, connected by slots with widths that are a representative fraction of the dimensions of the box. We expect choked flow, sonic shocks, and order-of-magnitude pressure and density drops from box to box, but this expectation will be tested in the simulation and then experiment. This work is supported by the Princeton Environmental Institute.

  16. Frequência de mola hidatiforme em tecidos obtidos por curetagem uterina Frequency of hydatidiform mole in tissue obtained by curettage

    Directory of Open Access Journals (Sweden)

    Andressa Biscaro

    2012-06-01

    Full Text Available OBJETIVO: Determinar a frequência de mola hidatiforme em tecidos obtidos por curetagem uterina. MÉTODOS: Estudo transversal, prospectivo e descritivo que incluiu pacientes submetidas à curetagem uterina por diagnóstico de aborto ou mola hidatiforme cujo material obtido foi encaminhado para exame anatomopatológico. Foram excluídas aquelas que não aceitaram participar da pesquisa, recusando-se a assinar o Termo de Consentimento Informado Livre e Esclarecido. Foram analisadas as seguintes variáveis: achados anatomopatológicos, idade, raça/cor, número de gestações e abortos prévios, idade gestacional no momento do diagnóstico, níveis séricos quantitativos da fração beta da gonadotrofina coriônica humana e achados ultrassonográficos. As variáveis foram empregadas para a verificação com o diagnóstico histológico, considerado o padrão-ouro. Os dados foram armazenados e analisados no software Microsoft Excel® e no programa Epi-Info, versão 6.0 (STATCALC e os resultados apresentados como frequência (porcentagem ou média±desvio padrão. Para a associação entre variáveis qualitativas foi usado o teste do χ², e admitiu-se significância estatística quando pPURPOSE: To determine the frequency of hydatiform mole in tissues obtained by curettage. METHODS: A cross-sectional, prospective and descriptive conducted on patients who underwent curretage due to a diagnosis of abortion or hydatiform mole whose material was sent for pathological examination. We excluded women who did not accept to participate and refused to sign the free informed consent form. We studied the following variables: pathological findings, age, race, number of pregnancies and previous abortions, gestational age at diagnosis, quantitative serum beta fraction of human chorionic gonadotropin and ultrasound findings. The data were compared to the to histological diagnosis, considered to be the gold standard. Data were stored and analyzed in Microsoft Excel

  17. R-22 vapor explosions

    International Nuclear Information System (INIS)

    Anderson, R.P.; Armstrong, D.R.

    1977-01-01

    Previous experimental and theoretical studies of R-22 vapor explosions are reviewed. Results from two experimental investigations of vapor explosions in a medium scale R-22/water system are reported. Measurements following the drop of an unrestrained mass of R-22 into a water tank demonstrated the existence of two types of interaction behavior. Release of a constrained mass of R-22 beneath the surface of a water tank improved the visual resolution of the system thus allowing identification of two interaction mechansims: at low water temperatures, R-22/water contact would produce immediate violent boiling; at high water temperatures a vapor film formed around its R-22 as it was released, explosions were generated by a surface wave which initiated at a single location and propagated along the vapor film as a shock wave. A new vapor explosion model is proposed, it suggests explosions are the result of a sequence of three independent steps: an initial mixing phase, a trigger and growth phase, and a mature phase where a propagating shock wave accelerates the two liquids into a collapsing vapor layer causing a high velocity impact which finely fragments and intermixes the two liquids

  18. Mystery Fractions

    Science.gov (United States)

    Bhattacharyya, Sonalee; Namakshi, Nama; Zunker, Christina; Warshauer, Hiroko K.; Warshauer, Max

    2016-01-01

    Making math more engaging for students is a challenge that every teacher faces on a daily basis. These authors write that they are constantly searching for rich problem-solving tasks that cover the necessary content, develop critical-thinking skills, and engage student interest. The Mystery Fraction activity provided here focuses on a key number…

  19. Influence of spatial environment on maze learning in an African mole-rat

    CSIR Research Space (South Africa)

    Du Toit, L

    2012-05-01

    Full Text Available -1 Anim Cogn DOI 10.1007/s10071-012-0503-0 Influence of spatial environment on maze learning in an African mole-rat Lydia du Toit ? Nigel C. Bennett ? Alecia Nickless ? Martin J. Whiting L. du Toit , A. Nickless , M. J. Whiting (email) School...

  20. The eye of the African mole-rat Cryptomys anselli : to see or not to see?

    NARCIS (Netherlands)

    Cernuda-Cernuda, R; Garcia-Fernandez, JM; Gordijn, MCM; Bovee-Geurts, PHM; DeGrip, WJ; de Grip, W.J.

    In an attempt to clarify its possible physiological role, we studied the eye of the Zambian mole rat Cryptomys anselli by light, electron and confocal microscopy using conventional staining as well as immunolabelling with rod and cone cell markers. The small eyes of Cryptomys are located

  1. The eye of the african mole-rat Cryptomys anselli: to see or not to see?

    NARCIS (Netherlands)

    Cernuda-Cernuda, R.; Garcia-Fernandez, J.M.; Gordijn, M.C.; Bovee-Geurts, P.H.M.; Grip, W.J. de

    2003-01-01

    In an attempt to clarify its possible physiological role, we studied the eye of the Zambian mole rat Cryptomys anselli by light, electron and confocal microscopy using conventional staining as well as immunolabelling with rod and cone cell markers. The small eyes of Cryptomys are located

  2. The reproductive biology of the giant Zambian mole-rat, Cryptomys ...

    African Journals Online (AJOL)

    1994-09-29

    Sep 29, 1994 ... gala (12° 27'S, 2T51'E) in the Copperbelt of northern Zam- hia. ... mole-rat, a pair of animals and a group comprising one male and three females .... Figure 1 Changes In bouy mass of a captive female Cr.vptom.vs mechowi ... The sex distribution was .... 'Ine social Cryptomys species are chmacteril,ed hy.

  3. Pre-evacuation hCG glycoforms in uneventful complete hydatidiform mole and persistent trophoblastic disease.

    NARCIS (Netherlands)

    Thomas, C.M.G.; Kerkmeijer, L.G.W.; Ariaens, H.J.; Steen, R. van der; Massuger, L.F.A.G.; Sweep, F.C.

    2010-01-01

    OBJECTIVE: To investigate whether the glycoform distribution patterns of human chorionic gonadotropin (hCG) obtained by chromatofocusing in pre-evacuation serum are different for patients who will eventually develop into persistent trophoblastic disease in case of complete hydatidiform mole

  4. Reading about the Power of Music: "Mole Music" and "Children of the Stone"

    Science.gov (United States)

    Cardany, Audrey Berger

    2016-01-01

    In this article, I review two books that address the power of music for the individual and group. Both books address the benefits of making, learning, and listening to music during times of conflict. The first brief review is David McPhail's picture book "Mole Music." The second is "Children of the Stone: The Power of Music in a…

  5. The Vital Role of Basic Mathematics in Teaching and Learning the Mole Concept

    Science.gov (United States)

    Mehrotra, Alka; Koul, Anjni

    2016-01-01

    This article focuses on the importance of activity-based teaching in understanding the mole concept and the vital role of basic mathematical operations. It describes needs-based training for teachers in a professional development programme in India. Analysis of test results before and after the training indicates that teachers improved their…

  6. Plasticity and constraints on social evolution in African mole-rats: ultimate and proximate factors.

    Science.gov (United States)

    Faulkes, Chris G; Bennett, Nigel C

    2013-05-19

    Here, we review comparative studies of African mole-rats (family Bathyergidae) to explain how constraints acting at the ultimate (environmental) and proximate (organismal) levels have led to convergent gains and losses of sociality within this extensive adaptive radiation of subterranean rodents endemic to sub-Saharan Africa. At the ultimate level, living in environments that range from mesic through to arid has led to both variation and flexibility in social organization among species, culminating in the pinnacle of social evolution in the eusocial naked and Damaraland mole-rats (Heterocephalus glaber and Fukomys damarensis). The common mole-rat (Cryptomys hottentotus) provides a model example of how plasticity in social traits exists within a single species inhabiting areas with different ecological constraint. At the proximate level, reproductive strategies and cooperative breeding may be constrained by the correlated evolution of a suite of traits including physiological suppression of reproduction, the development of physiological and morphological castes, and the mode of ovulatory control and seasonality in breeding. Furthermore, recent neurobiological advances indicate that differential patterns of neurotransmitter expression within the forebrain may underpin (and limit) either a solitary or group living/cooperative lifestyle not only in mole-rats, but also more widely among disparate mammalian taxa.

  7. case of natural queen succession in a captive colony of naked mole ...

    African Journals Online (AJOL)

    Naked mole-rats occur in large colonies where usually a single queen monopolizes reproduction. Queen succession occurs from within usually as a result of aggressive encounters with subordinate females that queue for reproductive succession following colony instability, which inevitably results in death of either the ...

  8. Comparative analysis of genome maintenance genes in naked mole rat, mouse, and human

    NARCIS (Netherlands)

    S.L. Macrae (Sheila L.); Q. Zhang (Quanwei); C. Lemetre (Christophe); I. Seim (Inge); R.B. Calder (Robert B.); J.H.J. Hoeijmakers (Jan); Y. Suh (Yousin); V.N. Gladyshev (Vadim N.); A. Seluanov (Andrei); V. Gorbunova (Vera); J. Vijg (Jan); Z.D. Zhang (Zhengdong D.)

    2015-01-01

    textabstractGenome maintenance (GM) is an essential defense system against aging and cancer, as both are characterized by increased genome instability. Here, we compared the copy number variation and mutation rate of 518 GM-associated genes in the naked mole rat (NMR), mouse, and human genomes. GM

  9. Morphological divergence of breeders and helpers in wild Damaraland mole-rat societies.

    Science.gov (United States)

    Young, Andrew J; Bennett, Nigel C

    2010-11-01

    The specialization of body shape to an individual's role within society represents a pinnacle of social evolution. Although commonplace among social insects, divergence in the body shapes of breeders and helpers has to date been documented in just one social vertebrate, the naked mole-rat, Heterocephalus glaber; an extraordinary species in which large colony size and frequent inbreeding may have favored the evolution of such specialization. Here, we present new evidence of morphological divergence between breeders and helpers in the Damaraland mole-rat, Fukomys damarensis; a much less socially extreme species that reflects an independent evolutionary origin of sociality. Using longitudinal data from wild populations, we show that dominant female Damaraland mole-rats, like many social insect queens, have a significantly more elongate body shape than subordinates. This difference arises not from a pre-existing difference in the body shapes of subordinates that do, and those that do not, become dominant, but from a modification to the growth trajectory of subordinates on dominance acquisition. Our findings reveal a wider role for morphological divergence within vertebrate societies and, as Damaraland mole-rats neither live in unusually large groups nor inbreed, suggest that circumstances favoring the evolution of such specializations may be more widespread among vertebrates than previously supposed. © 2010 The Author(s). Evolution© 2010 The Society for the Study of Evolution.

  10. Blunted behavioral and c Fos responses to acidic fumes in the African naked mole-rat.

    Science.gov (United States)

    LaVinka, Pamela Colleen; Park, Thomas J

    2012-01-01

    Acidosis in the skin triggers activation of pain pathways and behaviors indicative of pain in vertebrates. The exception is the naked mole-rat, the only known vertebrate to show physiological and behavioral insensitivity to acid pain in the skin. The goal of the present study was to determine behavioral and physiological responses of this species to airborne acidic fumes, which would be expected to affect the trigeminal pain pathway in other species. Behaviorally, naked mole-rats did not avoid fumes from moderately high concentrations of acetic acid (10 and 20%), and c Fos labeling showed no increase in activity in the trigeminal nuclei and nucleus tractus solitarius. In contrast, these concentrations triggered behavioral aversion and increased Fos activity in other laboratory rodents. For a very high concentration of acetic acid (50%), naked mole-rats showed significant avoidance behavior and increased Fos labeling in the nucleus tractus solitarius caudal region, which receives vagal chemosensory information. However, there was no increase in trigeminal labeling, and in fact, activity significantly decreased. This pattern is opposite of that associated with another irritant, ammonia fumes, which elicited an increase in trigeminal but not nucleus tractus solitarius Fos labeling, and no behavioral avoidance. Behavioral avoidance of acidic fumes, but no increased labeling in the trigeminal pain nucleus is consistent with the notion of adaptations to blunt acid pain, which would be advantageous for naked mole-rats as they normally live under chronically high levels of acidosis-inducing CO(2).

  11. Blunted behavioral and c Fos responses to acidic fumes in the African naked mole-rat.

    Directory of Open Access Journals (Sweden)

    Pamela Colleen LaVinka

    Full Text Available Acidosis in the skin triggers activation of pain pathways and behaviors indicative of pain in vertebrates. The exception is the naked mole-rat, the only known vertebrate to show physiological and behavioral insensitivity to acid pain in the skin. The goal of the present study was to determine behavioral and physiological responses of this species to airborne acidic fumes, which would be expected to affect the trigeminal pain pathway in other species. Behaviorally, naked mole-rats did not avoid fumes from moderately high concentrations of acetic acid (10 and 20%, and c Fos labeling showed no increase in activity in the trigeminal nuclei and nucleus tractus solitarius. In contrast, these concentrations triggered behavioral aversion and increased Fos activity in other laboratory rodents. For a very high concentration of acetic acid (50%, naked mole-rats showed significant avoidance behavior and increased Fos labeling in the nucleus tractus solitarius caudal region, which receives vagal chemosensory information. However, there was no increase in trigeminal labeling, and in fact, activity significantly decreased. This pattern is opposite of that associated with another irritant, ammonia fumes, which elicited an increase in trigeminal but not nucleus tractus solitarius Fos labeling, and no behavioral avoidance. Behavioral avoidance of acidic fumes, but no increased labeling in the trigeminal pain nucleus is consistent with the notion of adaptations to blunt acid pain, which would be advantageous for naked mole-rats as they normally live under chronically high levels of acidosis-inducing CO(2.

  12. Hydatidiform mole and fetus with normal karyotype: support of a separate entity

    DEFF Research Database (Denmark)

    Vejerslev, L O; Sunde, L; Hansen, B F

    1991-01-01

    Repetitive hydatidiform mole was observed in four pregnancies. The pregnancies presented with heavy bleeding and vomiting, but the post-evacuation courses were uncomplicated, with rapid regression of serum hCG levels. Cytogenetic investigations, analyses of restriction fragment length polymorphis...

  13. A Mole in the Sole: Case Report on Eccrine Poroma | Das | Internet ...

    African Journals Online (AJOL)

    Eccrine poroma is a benign tumor which arises from the intraepidermal portion of the eccrine sweat glands. 81 year old diabetic grandma worried about her persistently uncontrolled blood sugar owing to a painless mole in the sole of right foot for 2 years. Excisional biopsy revealed a sweat duct benign eccrine poroma.

  14. Hardness evaluation of cured urea-formaldehyde resins with different formaldehyde/urea mole ratios using nanoindentation method

    Science.gov (United States)

    Byung-Dae Park; Charles R. Frihart; Yan Yu; Adya P. Singh

    2013-01-01

    To understand the influence of formaldehyde/urea (F/U) mole ratio on the properties of urea–formaldehyde (UF) resins, this study investigated hardness of cured UF resins with different F/U mole ratios using a nanoindentation method. The traditional Brinell hardness (HB) method was also used...

  15. Biological and biochemical properties of human chorionic gonadotropin from urine of patients with hydatidiform mole and its radioimmunoassay

    International Nuclear Information System (INIS)

    Nishimura, Ryuichiro; Hamamoto, Tamotsu; Tanabe, Keizo; Takemori, Masayuki; Ashitaka, Yoshihiko

    1981-01-01

    Human chorionic gonadotropin (hCG) was extracted and purified from the urine of four patients with hydatidiform mole. The immunological activities of the hCG-hydatidiform mole by hCG radioimmunoassay (RIA) ranged from 9,380 to 9,700 IU/mg, and the biological activities measured by the immature rat ovarian weight method ranged from 7,250 to 7,780 IU/mg. The results of the amino acid compositions of all the hCG-hydatidiform moles were practically identical with those of hCG-normal pregnancies. The carbohydrate moiety of the hCG-hydatidiform mole was also suspected to be almost similar to that of hCG-normal pregnancies by the results of their in vitro and in vivo biological activities. It was demonstrated that hCG-hydatidiform mole was composed of α and β subunits (similar to a hCG-normal pregnancy) when hCG-hydatidiform mole was separated into subunits by SDS disc electrophoresis after treatment with mercaptoethanol. The RIA system of hCG-hydatidiform mole can be established. The concentrations of hCG in sera of normal pregnant women and patients with trophoblastic diseases assayed by hCG-hydatidiform mole RIA were equivalent to those obtained by a standard hCG RIA. Hence, a standard hCG-immunoassay method used in the management of trophoblastic diseases is considered reasonable so far as the immunoantigenecity of hCG is concerned. (author)

  16. Distribution of vasopressin in the brain of the eusocial naked mole-rat.

    Science.gov (United States)

    Rosen, Greta J; De Vries, Geert J; Goldman, Sharry L; Goldman, Bruce D; Forger, Nancy G

    2007-02-20

    Naked mole-rats are eusocial rodents that live in large subterranean colonies in which one queen breeds with one to three males. All other animals are nonbreeding subordinates. The external features of male and female subordinates, including their genitalia, are remarkably monomorphic, as is their behavior. Because vasopressin (VP) is associated with social behaviors and sex differences in other species, its distribution in naked mole-rats was of interest. We used immunohistochemistry to examine VP in the brains of subordinate and breeding naked mole-rats of both sexes. As in other mammals, VP-immunoreactive (-ir) somata were found in the paraventricular (PVN) and supraoptic nuclei (SON) and VP-ir projections from these nuclei ran through the internal and external zone of the median eminence. However, naked mole-rats had very few VP-ir cells in the bed nucleus of the stria terminalis (BST) and none in the suprachiasmatic nucleus (SCN); the extensive network of fine-caliber VP-ir fibers usually seen in projection sites of the BST and SCN were also absent. Equally unexpected was the abundance of large-caliber VP-ir fibers in the dorsomedial septum. VP immunoreactivity was generally similar in all groups, with the exception of VP-ir cell number in the dorsomedial hypothalamus (DMH). Breeders had a population of labeled cells in the DMH that was absent, or nearly absent, in subordinates. Future studies on the function of VP in these areas are needed to determine how the atypical distribution of VP immunoreactivity relates to eusociality and the unusual physiology of naked mole-rats.

  17. Vapor pressures and enthalpies of vaporization of azides

    International Nuclear Information System (INIS)

    Verevkin, Sergey P.; Emel'yanenko, Vladimir N.; Algarra, Manuel; Manuel Lopez-Romero, J.; Aguiar, Fabio; Enrique Rodriguez-Borges, J.; Esteves da Silva, Joaquim C.G.

    2011-01-01

    Highlights: → We prepared and measured vapor pressures and vaporization enthalpies of 7 azides. → We examined consistency of new and available in the literature data. → Data for geminal azides and azido-alkanes selected for thermochemical calculations. - Abstract: Vapor pressures of some azides have been determined by the transpiration method. The molar enthalpies of vaporization Δ l g H m of these compounds were derived from the temperature dependencies of vapor pressures. The measured data sets were successfully checked for internal consistency by comparison with vaporization enthalpies of similarly structured compounds.

  18. Fraction Reduction through Continued Fractions

    Science.gov (United States)

    Carley, Holly

    2011-01-01

    This article presents a method of reducing fractions without factoring. The ideas presented may be useful as a project for motivated students in an undergraduate number theory course. The discussion is related to the Euclidean Algorithm and its variations may lead to projects or early examples involving efficiency of an algorithm.

  19. Measurement of vapor behavior in tight-lattice bundles by neutron radiography

    International Nuclear Information System (INIS)

    Kureta, Masatoshi; Akimoto, Hajime

    2004-01-01

    Three-dimensional and instantaneous void fractions in tight-lattice 7-rod and 14-rod bundles were measured by neutron radiography in order to make clear the flow behavior and to verify the advanced fine-mesh numerical analysis codes for the R and D of the Reduced-Moderation Water Reactors (RMWR). Time-averaged 3D void fraction distribution is evaluated with the spatial resolution of 0.1 - 0.2 mm using neutron tomography, and consecutive change of vapor behavior is observed quantitatively with time step of 1 ms using high-frame-rate neutron radiography (HFR-NR). In this paper, void fraction distribution and vapor behavior of flow boiling of water in tight-lattice rod bundles are focused on and discussed based on the obtained results. 'High void fraction spot', 'void drift phenomenon', and 'vapor chimney' were observed under atmospheric pressure conditions. Here, 'high void fraction spot' indicates that high void fraction regions are appeared between adjacent rods, narrow space, at/near point of net vapor generation region. 'Void drift' and 'vapor chimney' represent that high void fraction region moves to wide triangular space and is formed a vapor flow channel so-called 'vapor chimney'. It was confirmed from the time-averaged 3D data that void fraction in the center is higher than that in the periphery. On the other hand, it was found from the HFR-NR experiments that big vapor bubbles and/or cluster flow upward intermittently not only in the center but in the periphery of the channel and, therefore, point of net vapor generation is scattered statistically in wide region. (author)

  20. Void fraction prediction in saturated flow boiling

    International Nuclear Information System (INIS)

    Francisco J Collado

    2005-01-01

    Full text of publication follows: An essential element in thermal-hydraulics is the accurate prediction of the vapor void fraction, or fraction of the flow cross-sectional area occupied by steam. Recently, the author has suggested to calculate void fraction working exclusively with thermodynamic properties. It is well known that the usual 'flow' quality, merely a mass flow rate ratio, is not at all a thermodynamic property because its expression in function of thermodynamic properties includes the slip ratio, which is a parameter of the process not a function of state. By the other hand, in the classic and well known expression of the void fraction - in function of the true mass fraction of vapor (also called 'static' quality), and the vapor and liquid densities - does not appear the slip ratio. Of course, this would suggest a direct procedure for calculating the void fraction, provided we had an accurate value of the true mass fraction of vapor, clearly from the heat balance. However the classic heat balance is usually stated in function of the 'flow' quality, what sounds really contradictory because this parameter, as we have noted above, is not at all a thermodynamic property. Then we should check against real data the actual relationship between the thermodynamic properties and the applied heat. For saturated flow boiling just from the inlet of the heated tube, and not having into account the kinetic and potential terms, the uniform applied heat per unit mass of inlet water and per unit length (in short, specific linear heat) should be closely related to a (constant) slope of the mixture enthalpy. In this work, we have checked the relation between the specific linear heat and the thermodynamic enthalpy of the liquid-vapor mixture using the actual mass fraction. This true mass fraction is calculated using the accurate measurements of the outlet void fraction taken during the Cambridge project by Knights and Thom in the sixties for vertical and horizontal

  1. Search for fractional charge

    International Nuclear Information System (INIS)

    Turner, R.E.

    1984-01-01

    A search was made for fractional charges of the form Z plus two-thirds e, where Z is an integer. It was assumed that the charges exist in natural form bound with other fractional charges in neutral molecules. It was further assumed that these neutral molecules are present in air. Two concentration schemes were employed. One sample was derived from the waste gases from a xenon distillation plant. This assumes that high mass, low vapor pressure components of air are concentrated along with the xenon. The second sample involved ionizing air, allowing a brief recombination period, and then collecting residual ions on the surface of titanium discs. Both samples were analyzed at the University of Rochester in a system using a tandem Van de Graff to accelerate particles through an essentially electrostatic beam handling system. The detector system employed both a Time of Flight and an energy-sensitive gas ionization detector. In the most sensitive mode of analysis, a gas absorber was inserted in the beam path to block the intense background. The presence of an absorber limited the search to highly penetrating particles. Effectively, this limited the search to particles with low Z and masses greater than roughly fifty GeV. The final sensitivities attained were on the order of 1 x 10 -20 for the ionized air sample and 1 x 10 -21 for the gas sample. A discussion of the caveats that could reduce the actual level of sensitivity is included

  2. Measurement and correlation of vapor-liquid equilibria for a binary system containing 1-butyl-3-methylimidazolium tridecafluorohexyl sulfonate and carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Soon Kang; Park, Yoon Kook [Hongik University, Sejong (Korea, Republic of)

    2016-01-15

    Using a high-pressure variable-volume view cell, the vapor-liquid equilibria of the binary system CO{sub 2} and 1-butyl-3-methylimidazolium tridecafluorohexylsulfonate ([BMIM][TDfO]) were determined. The CO{sub 2} mole fraction ranged from 0.104 to 0.952 over a temperature range of 298.2-323.2 K. Both the Peng-Robinson and Soave-Redlich- Kwong equations of state were applied with two different mixing rules to correlate with the experimentally obtained results. Increasing the alkyl chain length in perfluorinated sulfonate anion mother structure from methyl to hexyl markedly increased the CO{sub 2} solubility. To investigate the effect of the number of fluorine atoms in the anion on the phase behavior of imidazolium-based ionic liquid, these experimental results were then compared with those reported in previous experimental studies of 1-alkyl-3-methylimidazolium cations-including ionic liquid+CO{sub 2} binary system.

  3. Vaporization of irradiated droplets

    International Nuclear Information System (INIS)

    Armstrong, R.L.; O'Rourke, P.J.; Zardecki, A.

    1986-01-01

    The vaporization of a spherically symmetric liquid droplet subject to a high-intensity laser flux is investigated on the basis of a hydrodynamic description of the system composed of the vapor and ambient gas. In the limit of the convective vaporization, the boundary conditions at the fluid--gas interface are formulated by using the notion of a Knudsen layer in which translational equilibrium is established. This leads to approximate jump conditions at the interface. For homogeneous energy deposition, the hydrodynamic equations are solved numerically with the aid of the CON1D computer code (''CON1D: A computer program for calculating spherically symmetric droplet combustion,'' Los Alamos National Laboratory Report No. LA-10269-MS, December, 1984), based on the implict continuous--fluid Eulerian (ICE) [J. Comput. Phys. 8, 197 (1971)] and arbitrary Lagrangian--Eulerian (ALE) [J. Comput. Phys. 14, 1227 (1974)] numerical mehtods. The solutions exhibit the existence of two shock waves propagating in opposite directions with respect to the contact discontinuity surface that separates the ambient gas and vapor

  4. Heat of vaporization spectrometer

    International Nuclear Information System (INIS)

    Edwards, D. Jr.

    1978-01-01

    Multilayer desorption measurements of various substances adsorbed on a stainless steel substrate are found to exhibit desorption profiles consistent with a zeroth order desorption model. The singleness of the desorption transients together with their narrow peak widths makes the technique ideally suited for a heat of vaporization spectrometer for either substance analysis or identification

  5. Enthalpy of Vaporization and Vapor Pressures: An Inexpensive Apparatus

    Science.gov (United States)

    Battino, Rubin; Dolson, David A.; Hall, Michael A.; Letcher, Trevor M.

    2007-01-01

    A simple and inexpensive method to determine the enthalpy of vaporization of liquids by measuring vapor pressure as a function of temperature is described. The vapor pressures measured with the stopcock cell were higher than the literature values and those measured with the sidearm rubber septum cell were both higher and lower than literature…

  6. Sociality and the telencephalic distribution of corticotrophin-releasing factor, urocortin 3, and binding sites for CRF type 1 and type 2 receptors: A comparative study of eusocial naked mole-rats and solitary Cape mole-rats.

    Science.gov (United States)

    Coen, Clive W; Kalamatianos, Theodosis; Oosthuizen, Maria K; Poorun, Ravi; Faulkes, Christopher G; Bennett, Nigel C

    2015-11-01

    Various aspects of social behavior are influenced by the highly conserved corticotrophin-releasing factor (CRF) family of peptides and receptors in the mammalian telencephalon. This study has mapped and compared the telencephalic distribution of the CRF receptors, CRF1 and CRF2 , and two of their ligands, CRF and urocortin 3, respectively, in African mole-rat species with diametrically opposed social behavior. Naked mole-rats live in large eusocial colonies that are characterized by exceptional levels of social cohesion, tolerance, and cooperation in burrowing, foraging, defense, and alloparental care for the offspring of the single reproductive female. Cape mole-rats are solitary; they tolerate conspecifics only fleetingly during the breeding season. The telencephalic sites at which the level of CRF1 binding in naked mole-rats exceeds that in Cape mole-rats include the basolateral amygdaloid nucleus, hippocampal CA3 subfield, and dentate gyrus; in contrast, the level is greater in Cape mole-rats in the shell of the nucleus accumbens and medial habenular nucleus. For CRF2 binding, the sites with a greater level in naked mole-rats include the basolateral amygdaloid nucleus and dentate gyrus, but the septohippocampal nucleus, lateral septal nuclei, amygdalostriatal transition area, bed nucleus of the stria terminalis, and medial habenular nucleus display a greater level in Cape mole-rats. The results are discussed with reference to neuroanatomical and behavioral studies of various species, including monogamous and promiscuous voles. By analogy with findings in those species, we speculate that the abundance of CRF1 binding in the nucleus accumbens of Cape mole-rats reflects their lack of affiliative behavior. © 2015 Wiley Periodicals, Inc.

  7. Acetone vapor sensing using a vertical cavity surface emitting laser diode coated with polystyrene

    DEFF Research Database (Denmark)

    Ansbæk, Thor; Nielsen, Claus Højgaard; Larsen, Niels Bent

    2009-01-01

    We report theoretical and experimental on a new vapor sensor, using a single-mode vertical-cavity surface-emitting laser (VCSEL) coated with a polymer sensor coating, which can detect acetone vapor at a volume fraction of 2.5%. The sensor provides the advantage of standard packaging, small form...

  8. O2 binding and CO2 sensitivity in haemoglobins of subterranean African mole rats

    DEFF Research Database (Denmark)

    Weber, Roy E.; Jarvis, Jennifer U. M.; Fago, Angela

    2017-01-01

    that predictably safeguard pulmonary loading under hypoxic and hypercapnic burrow conditions. The O2 binding characteristics are discussed in relation to available information on the primary structure of Hbs from adult and developmental stages of mammals subjected to hypoxia and hypercapnia and the molecular......Inhabiting deep and sealed subterranean burrows, mole rats exhibit a remarkable suite of specializations, including eusociality (living in colonies with single breeding queens), extraordinary longevity, cancer immunity and poikilothermy, and extreme tolerance of hypoxia and hypercapnia. With little...... and 2,3-diphosphoglycerate (DPG, the major allosteric modulator of Hb-O2 affinity in red blood cells) in four social and two solitary species of African mole rats (family Bathyergidae) originating from different biomes and soil types across Central and Southern Africa. We found no consistent patterns...

  9. Effects of ultraviolet radiation on mole rats kidney: A histopathologic and ultrastructural study

    Directory of Open Access Journals (Sweden)

    Hüseyin Türker

    2014-04-01

    Full Text Available The purpose of this study was to realize the ultrastructural effects of ultraviolet radiation on the kidney tissue cells of mole rats (Spalax leucodon. The mole rats of 180–200 g body weight were divided into the control and radiation-trial groups. The control group was not given any radiation. The other groups were irradiated with artificially produced UVC radiation for 14, 28 and 60 days. The kidney tissue samples were prepared at the end of experiments and analyzed by the light and electron microscope. Several effects were observed in the kidney tissues cells analyzed in accordance with the dose magnitude of radiation. These results clearly show the detrimental effects of UVC radiation on kidney tissue cells in exposure periods dependent on radiation dose and exposure time.

  10. Locomotor Activity and Body Temperature Patterns over a Temperature Gradient in the Highveld Mole-Rat (Cryptomys hottentotus pretoriae).

    Science.gov (United States)

    Haupt, Meghan; Bennett, Nigel C; Oosthuizen, Maria K

    2017-01-01

    African mole-rats are strictly subterranean mammals that live in extensive burrow systems. High humidity levels in the burrows prevent mole-rats from thermoregulating using evaporative cooling. However, the relatively stable environment of the burrows promotes moderate temperatures and small daily temperature fluctuations. Mole-rats therefore display a relatively wide range of thermoregulation abilities. Some species cannot maintain their body temperatures at a constant level, whereas others employ behavioural thermoregulation. Here we test the effect of ambient temperature on locomotor activity and body temperature, and the relationship between the two parameters, in the highveld mole-rat. We exposed mole-rats to a 12L:12D and a DD light cycle at ambient temperatures of 30°C, 25°C and 20°C while locomotor activity and body temperature were measured simultaneously. In addition, we investigated the endogenous rhythms of locomotor activity and body temperature at different ambient temperatures. Mole-rats displayed nocturnal activity at all three ambient temperatures and were most active at 20°C, but least active at 30°C. Body temperature was highest at 30°C and lowest at 20°C, and the daily cycle was highly correlated with locomotor activity. We show that the mole-rats have endogenous rhythms for both locomotor activity and body temperature. However, the endogenous body temperature rhythm appears to be less robust compared to the locomotor activity rhythm. Female mole-rats appear to be more sensitive to temperature changes than males, increased heterothermy is evident at lower ambient temperatures, whilst males show smaller variation in their body temperatures with changing ambient temperatures. Mole-rats may rely more heavily on behavioural thermoregulation as it is more energy efficient in an already challenging environment.

  11. Factors in Early Adolescence Associated With a Mole-Prone Phenotype in Late Adolescence.

    Science.gov (United States)

    Xu, Haoming; Marchetti, Michael A; Dusza, Stephen W; Chung, Esther; Fonseca, Maira; Scope, Alon; Geller, Alan C; Bishop, Marilyn; Marghoob, Ashfaq A; Halpern, Allan C

    2017-10-01

    Nevi are important phenotypic risk factors for melanoma in adults. Few studies have examined the constitutional and behavioral factors associated with a mole-prone phenotype in adolescents. To identify host, behavioral, and dermoscopic factors in early adolescence (age, 14 years) that are associated with a mole-prone phenotype in late adolescence (age, 17 years). A prospective observational cohort study from the Study of Nevi in Children was conducted from January 1, 2009, to December 31, 2014, with a 2- to 3-year follow-up. A total of 569 students from the school system in Framingham, Massachusetts, were enrolled in the 8th or 9th grade (baseline; mean [SD] age, 14.4 [0.7] years). The overall retention rate was 73.3%, and 417 students were reassessed in the 11th grade. Mole-prone phenotype in the 11th grade, defined as total nevus count of the back and 1 randomly selected leg in the top decile of the cohort or having any nevi greater than 5 mm in diameter. Of the 417 students assessed at follow-up in the 11th grade (166 females and 251 males; mean [SD] age, 17.0 [0.4] years), 111 participants (26.6%) demonstrated a mole-prone phenotype: 69 students (62.2%) with 1 nevus greater than 5 mm in diameter, 23 students (20.7%) with total nevus count in the top decile, and 19 students (17.1%) with both characteristics. On multivariate analysis, baseline total nevus count (adjusted odds ratio, 9.08; 95% CI, 4.0-23.7; P adolescents for higher-intensity counseling about sun protection and skin self-examination.

  12. Naked mole-rat cortical neurons are resistant to acid-induced cell death

    OpenAIRE

    Husson, Zoé; Smith, Ewan S

    2018-01-01

    Abstract Regulation of brain pH is a critical homeostatic process and changes in brain pH modulate various ion channels and receptors and thus neuronal excitability. Tissue acidosis, resulting from hypoxia or hypercapnia, can activate various proteins and ion channels, among which acid-sensing ion channels (ASICs) a family of primarily Na+ permeable ion channels, which alongside classical excitotoxicity causes neuronal death. Naked mole-rats (NMRs, Heterocephalus glaber) are ...

  13. Digital dissection of the masticatory muscles of the naked mole-rat, Heterocephalus glaber (Mammalia, Rodentia

    Directory of Open Access Journals (Sweden)

    Philip G. Cox

    2014-06-01

    Full Text Available The naked mole-rat, Heterocephalus glaber, of the family Bathyergidae is a subterranean rodent that feeds on underground roots and tubers and digs extensive tunnel systems with its incisors. It is a highly unusual mammal with regard to its social structure, longevity, pain insensitivity and cancer resistance, all of which have made it the subject of a great deal of research in recent years. Yet, much of the basic anatomy of this species remains undocumented. In this paper, we describe the morphology of the jaw-closing musculature of the naked mole-rat, as revealed by contrast-enhanced micro-computed tomography. This technique uses an iodine stain to enable the imaging of soft tissues with microCT. The iodine-enhanced scans were used to create 3D reconstructions of the naked mole-rat masticatory muscles from which muscle masses were calculated. The jaw-closing musculature of Heterocephalus glaber is relatively very large compared to other rodents and is dominated by the superficial masseter, the deep masseter and the temporalis. The temporalis in particular is large for a rodent, covering the entirety of the braincase and much of the rear part of the orbit. The morphology of the masseter complex described here differs from two other published descriptions of bathyergid masticatory muscles, but is more similar to the arrangement seen in other rodent families. The zygomaticomandibularis (ZM muscle does not protrude through the infraorbital foramen on to the rostrum and thus the naked mole-rat should be considered protrogomorphous rather than hystricomorphous, and the morphology is consistent with secondarily lost hystricomorphy as has been previously suggested for Bathyergidae. Overall, the morphology of the masticatory musculature indicates a species with a high bite force and a wide gape–both important adaptations for a life dominated by digging with the incisors.

  14. Family Wide Molecular Adaptations to Underground Life in African Mole-Rats Revealed by Phylogenomic Analysis.

    Science.gov (United States)

    Davies, Kalina T J; Bennett, Nigel C; Tsagkogeorga, Georgia; Rossiter, Stephen J; Faulkes, Christopher G

    2015-12-01

    During their evolutionary radiation, mammals have colonized diverse habitats. Arguably the subterranean niche is the most inhospitable of these, characterized by reduced oxygen, elevated carbon dioxide, absence of light, scarcity of food, and a substrate that is energetically costly to burrow through. Of all lineages to have transitioned to a subterranean niche, African mole-rats are one of the most successful. Much of their ecological success can be attributed to a diet of plant storage organs, which has allowed them to colonize climatically varied habitats across sub-Saharan Africa, and has probably contributed to the evolution of their diverse social systems. Yet despite their many remarkable phenotypic specializations, little is known about molecular adaptations underlying these traits. To address this, we sequenced the transcriptomes of seven mole-rat taxa, including three solitary species, and combined new sequences with existing genomic data sets. Alignments of more than 13,000 protein-coding genes encompassed, for the first time, all six genera and the full spectrum of ecological and social variation in the clade. We detected positive selection within the mole-rat clade and along ancestral branches in approximately 700 genes including loci associated with tumorigenesis, aging, morphological development, and sociality. By combining these results with gene ontology annotation and protein-protein networks, we identified several clusters of functionally related genes. This family wide analysis of molecular evolution in mole-rats has identified a suite of positively selected genes, deepening our understanding of the extreme phenotypic traits exhibited by this group. © The Author 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  15. Vapor pressure and enthalpy of vaporization of linear aliphatic alkanediamines

    International Nuclear Information System (INIS)

    Pozdeev, Vasiliy A.; Verevkin, Sergey P.

    2011-01-01

    Highlights: → We measured vapor pressure of diamines H 2 N-(CH 2 ) n -NH 2 with n = 3 to 12. → Vaporization enthalpies at 298 K were derived. → We examined consistency of new and available in the literature data. → Enthalpies of vaporization show linear dependence on numbers n. → Enthalpies of vaporization correlate linearly with Kovat's indices. - Abstract: Vapor pressures and the molar enthalpies of vaporization of the linear aliphatic alkanediamines H 2 N-(CH 2 ) n -NH 2 with n = (3 to 12) have been determined using the transpiration method. A linear correlation of enthalpies of vaporization (at T = 298.15 K) of the alkanediamines with the number n and with the Kovat's indices has been found, proving the internal consistency of the measured data.

  16. Investigation of the presence and antinociceptive function of muscarinic acetylcholine receptors in the African naked mole-rat (Heterocephalus glaber)

    DEFF Research Database (Denmark)

    Jørgensen, Kristine B.; Krogh-Jensen, Karen; Pickering, Darryl S

    2016-01-01

    The present study investigated the cholinergic system in the African naked mole-rat (Heterocephalus glaber) with focus on the muscarinic acetylcholine receptor subtypes M1 and M4. The protein sequences for the subtypes m 1–5 of the naked mole-rat were compared to that of the house mouse (Mus...... musculus) using basic local alignment search tool (BLAST). The presence and function of M1 and M4 was investigated in vivo, using the formalin test with the muscarinic receptor agonists xanomeline and VU0152100. Spinal cord tissue from the naked mole-rat was used for receptor saturation binding studies...

  17. Fractional separation of hydrocarbon vapours

    Energy Technology Data Exchange (ETDEWEB)

    1937-07-10

    A process is described for converting higher boiling hydrocarbons to lower boiling hydrocarbons by subjecting them at elevated temperatures to a conversion operation, then separating the higher and lower boiling fractions. The separation takes place while the reaction products are maintained in the vapor phase by contact with a mass of solid porous material which has little or no catalytic activity but does have a preferential absorption property for higher boiling hydrocarbons so that the lower boiling part of the reaction products pass through the separation zone while the heavier hydrocarbons are retained. The separation is accomplished without substantial loss of heat of these reaction products.

  18. Cancer resistance in the blind mole rat is mediated by concerted necrotic cell death mechanism

    Science.gov (United States)

    Gorbunova, Vera; Hine, Christopher; Tian, Xiao; Ablaeva, Julia; Gudkov, Andrei V.; Nevo, Eviatar; Seluanov, Andrei

    2012-01-01

    Blind mole rats Spalax (BMR) are small subterranean rodents common in the Middle East. BMR is distinguished by its adaptations to life underground, remarkable longevity (with a maximum documented lifespan of 21 y), and resistance to cancer. Spontaneous tumors have never been observed in spalacids. To understand the mechanisms responsible for this resistance, we examined the growth of BMR fibroblasts in vitro of the species Spalax judaei and Spalax golani. BMR cells proliferated actively for 7–20 population doublings, after which the cells began secreting IFN-β, and the cultures underwent massive necrotic cell death within 3 d. The necrotic cell death phenomenon was independent of culture conditions or telomere shortening. Interestingly, this cell behavior was distinct from that observed in another long-lived and cancer-resistant African mole rat, Heterocephalus glaber, the naked mole rat in which cells display hypersensitivity to contact inhibition. Sequestration of p53 and Rb proteins using SV40 large T antigen completely rescued necrotic cell death. Our results suggest that cancer resistance of BMR is conferred by massive necrotic response to overproliferation mediated by p53 and Rb pathways, and triggered by the release of IFN-β. Thus, we have identified a unique mechanism that contributes to cancer resistance of this subterranean mammal extremely adapted to life underground. PMID:23129611

  19. Radioimmunoassay of β sub unit HCG following hydatidiform mole or chorionic carcinoma

    International Nuclear Information System (INIS)

    Tscherne, G.; Puerstner, P.

    1979-01-01

    The radioimmunoassay of Beta Sub Unit HCG in the serum heralds a marked improvement in the diagnosis of gestational trophoblastic disease. In nine cases of hydatidiform mole and three cases of chorionic carcinoma serial examinations of the Beta Sub Unit HCG were performed. When the immunologic pregnancy test became negative following a hydatidiform mole or following treatment of chorionic carcinoma, the HCG excretion remained above detectable values for several more weeks. The decrease of Beta Sub Unit serum HCG was either linear or in fluctuations. The detection of fluctuations or a secondary rise in the Beta Sub Unit HCG titre permits the early diagnosis of invasive trophoblastic disease following hydatidiform mole or of insufficient treatment or recurrence in cases of chorionic carcinoma. Our results suggest that the optimal follow-up with Beta Sub Unit serum HCG is by weekly determinations until four consecutive determinations remained negative. This is followed by two determinations at bi-weekly intervals and thereafter monthly follow-up examinations. (orig.) 891 AJ/orig. 892 BRE [de

  20. Sex, social status, and CRF receptor densities in naked mole-rats.

    Science.gov (United States)

    Beery, Annaliese K; Bicks, Lucy; Mooney, Skyler J; Goodwin, Nastacia L; Holmes, Melissa M

    2016-02-01

    Naked mole-rats (Heterocephalus glaber) live in groups that are notable for their large size and caste structure, with breeding monopolized by a single female and a small number of males. Recent studies have demonstrated substantial differences between the brains of breeders and subordinates induced by changes in social standing. Corticotropin-releasing factor (CRF) receptors-which bind the hormone CRF as well as related peptides-are important regulators of stress and anxiety, and are emerging as factors affecting social behavior. We conducted autoradiographic analyses of CRF1 and CRF2 receptor binding densities in female and male naked mole-rats varying in breeding status. Both globally and in specific brain regions, CRF1 receptor densities varied with breeding status. CRF1 receptor densities were higher in subordinates across brain regions, and particularly in the piriform cortex and cortical amygdala. Sex differences were present in CRF2 receptor binding densities, as is the case in multiple vole species. CRF2 receptor densities were higher in females, both globally and in the cortical amygdala and lateral amygdalar nucleus. These results provide novel insights into the neurobiology of social hierarchy in naked mole-rats, and add to a growing body of work that links changes in the CRF system with social behavior. © 2015 Wiley Periodicals, Inc.

  1. Cutaneous and periodontal inputs to the cerebellum of the naked mole-rat (Heterocephalus glaber).

    Science.gov (United States)

    Sarko, Diana K; Leitch, Duncan B; Catania, Kenneth C

    2013-01-01

    The naked mole-rat (Heterocephalus glaber) is a small fossorial rodent with specialized dentition that is reflected by the large cortical area dedicated to representation of the prominent incisors. Due to naked mole-rats' behavioral reliance on the incisors for digging and for manipulating objects, as well as their ability to move the lower incisors independently, we hypothesized that expanded somatosensory representations of the incisors would be present within the cerebellum in order to accommodate a greater degree of proprioceptive, cutaneous, and periodontal input. Multiunit electrophysiological recordings targeting the ansiform lobule were used to investigate tactile inputs from receptive fields on the entire body with a focus on the incisors. Similar to other rodents, a fractured somatotopy appeared to be present with discrete representations of the same receptive fields repeated within each folium of the cerebellum. These findings confirm the presence of somatosensory inputs to a large area of the naked mole-rat cerebellum with particularly extensive representations of the lower incisors and mystacial vibrissae. We speculate that these extensive inputs facilitate processing of tactile cues as part of a sensorimotor integration network that optimizes how sensory stimuli are acquired through active exploration and in turn adjusts motor outputs (such as independent movement of the lower incisors). These results highlight the diverse sensory specializations and corresponding brain organizational schemes that have evolved in different mammals to facilitate exploration of and interaction with their environment.

  2. Cutaneous and periodontal inputs to the cerebellum of the naked mole-rat (Heterocephalus glaber

    Directory of Open Access Journals (Sweden)

    Diana K Sarko

    2013-11-01

    Full Text Available The naked mole-rat (Heterocephalus glaber is a small fossorial rodent with specialized dentition that is reflected by the large cortical area dedicated to representation of the prominent incisors. Due to naked mole-rats’ behavioral reliance on the incisors for digging and for manipulating objects, as well as their ability to move the lower incisors independently, we hypothesized that expanded somatosensory representations of the incisors would be present within the cerebellum in order to accommodate a greater degree of proprioceptive, cutaneous, and periodontal input. Multiunit electrophysiological recordings targeting the ansiform lobule were used to investigate tactile inputs from receptive fields on the entire body with a focus on the incisors. Similar to other rodents, a fractured somatotopy appeared to be present with discrete representations of the same receptive fields repeated within each folium of the cerebellum. These findings confirm the presence of somatosensory inputs to a large area of the naked mole-rat cerebellum with particularly extensive representations of the lower incisors and mystacial vibrissae. We speculate that these extensive inputs facilitate processing of tactile cues as part of a sensorimotor integration network that optimizes how sensory stimuli are acquired through active exploration and in turn adjusts motor outputs (such as independent movement of the lower incisors. These results highlight the diverse sensory specializations and corresponding brain organizational schemes that have evolved in different mammals to facilitate exploration of and interaction with their environment.

  3. Naked mole-rat mortality rates defy Gompertzian laws by not increasing with age

    Science.gov (United States)

    Ruby, J Graham; Smith, Megan

    2018-01-01

    The longest-lived rodent, the naked mole-rat (Heterocephalus glaber), has a reported maximum lifespan of >30 years and exhibits delayed and/or attenuated age-associated physiological declines. We questioned whether these mouse-sized, eusocial rodents conform to Gompertzian mortality laws by experiencing an exponentially increasing risk of death as they get older. We compiled and analyzed a large compendium of historical naked mole-rat lifespan data with >3000 data points. Kaplan-Meier analyses revealed a substantial portion of the population to have survived at 30 years of age. Moreover, unlike all other mammals studied to date, and regardless of sex or breeding-status, the age-specific hazard of mortality did not increase with age, even at ages 25-fold past their time to reproductive maturity. This absence of hazard increase with age, in defiance of Gompertz’s law, uniquely identifies the naked mole-rat as a non-aging mammal, confirming its status as an exceptional model for biogerontology. PMID:29364116

  4. Moles (Nevi)

    Science.gov (United States)

    ... Registration General information Housing & travel Education Exhibit hall Mobile app 2019 Annual Meeting Derm Exam Prep Course ... SkinPAC State societies Scope of practice Truth in advertising NP/PA laws Action center Public and patients ...

  5. Hydatidiform mole

    Science.gov (United States)

    ... avoid another pregnancy and to use a reliable contraceptive for 6 to 12 months after treatment for ... Hockberger RS, Walls RM, et al, eds. Rosen's Emergency Medicine . 8th ed. Philadelphia, PA: Elsevier Saunders; 2014: ...

  6. Constrained Vapor Bubble Experiment

    Science.gov (United States)

    Gokhale, Shripad; Plawsky, Joel; Wayner, Peter C., Jr.; Zheng, Ling; Wang, Ying-Xi

    2002-11-01

    Microgravity experiments on the Constrained Vapor Bubble Heat Exchanger, CVB, are being developed for the International Space Station. In particular, we present results of a precursory experimental and theoretical study of the vertical Constrained Vapor Bubble in the Earth's environment. A novel non-isothermal experimental setup was designed and built to study the transport processes in an ethanol/quartz vertical CVB system. Temperature profiles were measured using an in situ PC (personal computer)-based LabView data acquisition system via thermocouples. Film thickness profiles were measured using interferometry. A theoretical model was developed to predict the curvature profile of the stable film in the evaporator. The concept of the total amount of evaporation, which can be obtained directly by integrating the experimental temperature profile, was introduced. Experimentally measured curvature profiles are in good agreement with modeling results. For microgravity conditions, an analytical expression, which reveals an inherent relation between temperature and curvature profiles, was derived.

  7. Vapor condensation device

    International Nuclear Information System (INIS)

    Sakurai, Manabu; Hirayama, Fumio; Kurosawa, Setsumi; Yoshikawa, Jun; Hosaka, Seiichi.

    1992-01-01

    The present invention enables to separate and remove 14 C as CO 3 - ions without condensation in a vapor condensation can of a nuclear facility. That is, the vapor condensation device of the nuclear facility comprises (1) a spray pipe for spraying an acidic aqueous solution to the evaporation surface of an evaporation section, (2) a spray pump for sending the acidic aqueous solution to the spray pipe, (3) a tank for storing the acidic aqueous solution, (4) a pH sensor for detecting pH of the evaporation section, (5) a pH control section for controlling the spray pump, depending on the result of the detection of the pH sensor. With such a constitution, the pH of liquid wastes on the vaporization surface is controlled to 7 by spraying an aqueous solution of dilute sulfuric acid to the evaporation surface, thereby enabling to increase the transfer rate of 14 C to condensates to 60 to 70%. If 14 C is separated and removed as a CO 2 gas from the evaporation surface, the pH of the liquid wastes returns to the alkaline range of 9 to 10 and the liquid wastes are returned to a heating section. The amount of spraying the aqueous solution of dilute sulfuric acid can be controlled till the pH is reduced to 5. (I.S.)

  8. The vapor pressures of explosives

    Energy Technology Data Exchange (ETDEWEB)

    Ewing, Robert G.; Waltman, Melanie J.; Atkinson, David A.; Grate, Jay W.; Hotchkiss, Peter

    2013-01-05

    The vapor pressures of many explosive compounds are extremely low and thus determining accurate values proves difficult. Many researchers, using a variety of methods, have measured and reported the vapor pressures of explosives compounds at single temperatures, or as a function of temperature using vapor pressure equations. There are large variations in reported vapor pressures for many of these compounds, and some errors exist within individual papers. This article provides a review of explosive vapor pressures and describes the methods used to determine them. We have compiled primary vapor pressure relationships traceable to the original citations and include the temperature ranges for which they have been determined. Corrected values are reported as needed and described in the text. In addition, after critically examining the available data, we calculate and tabulate vapor pressures at 25 °C.

  9. VAPOR PRESSURES AND HEATS OF VAPORIZATION OF PRIMARY COAL TARS

    Energy Technology Data Exchange (ETDEWEB)

    Eric M. Suuberg; Vahur Oja

    1997-07-01

    This project had as its main focus the determination of vapor pressures of coal pyrolysis tars. It involved performing measurements of these vapor pressures and from them, developing vapor pressure correlations suitable for use in advanced pyrolysis models (those models which explicitly account for mass transport limitations). This report is divided into five main chapters. Each chapter is a relatively stand-alone section. Chapter A reviews the general nature of coal tars and gives a summary of existing vapor pressure correlations for coal tars and model compounds. Chapter B summarizes the main experimental approaches for coal tar preparation and characterization which have been used throughout the project. Chapter C is concerned with the selection of the model compounds for coal pyrolysis tars and reviews the data available to us on the vapor pressures of high boiling point aromatic compounds. This chapter also deals with the question of identifying factors that govern the vapor pressures of coal tar model materials and their mixtures. Chapter D covers the vapor pressures and heats of vaporization of primary cellulose tars. Chapter E discusses the results of the main focus of this study. In summary, this work provides improved understanding of the volatility of coal and cellulose pyrolysis tars. It has resulted in new experimentally verified vapor pressure correlations for use in pyrolysis models. Further research on this topic should aim at developing general vapor pressure correlations for all coal tars, based on their molecular weight together with certain specific chemical characteristics i.e. hydroxyl group content.

  10. Population characteristics of the mole crab, Hippa adactyla Fabricius, in the intertidal sediment at Kavaratti Atoll, Lakshadweep Islands

    Digital Repository Service at National Institute of Oceanography (India)

    Ingole, B.S.; Sreepada, R.A.; Ansari, Z.A.; Parulekar, A.H.

    Some population characteristics of a little known mole crab Hippa adactyla from the sandy intertidal habitat of Kavaratti atoll, Lakshadweep islands, were studied for understanding the resource potentials besides some features of breeding behavior...

  11. Community structure variability of Uropodina mites (Acari: Mesostigmata) in nests of the common mole, Talpa europaea, in Central Europe

    OpenAIRE

    Napiera?a, Agnieszka; M?dra, Anna; Leszczy?ska-Deja, Kornelia; Gwiazdowicz, Dariusz J.; Go?dyn, Bart?omiej; B?oszyk, Jerzy

    2016-01-01

    Underground nests of Talpa europaea, known as the common mole, are very specific microhabitats, which are also quite often inhabited by various groups of arthropods. Mites from the suborder Uropodina (Acari: Mesostigmata) are only one of them. One could expect that mole nests that are closely located are inhabited by communities of arthropods with similar species composition and structure. However, results of empirical studies clearly show that even nests which are close to each other can be ...

  12. Efficacy of NETDC (New England Trophoblastic Disease Center prognostic index score to predict gestational trophoblastic tumor from hydatidiform mole

    Directory of Open Access Journals (Sweden)

    Khrismawan Khrismawan

    2004-03-01

    Full Text Available A prospective longitudinal analytic study assessing the efficacy of NETDC (New England Trophoblastic Disease Center prognostic index score in predicting malignancy after hydatidiform mole had been performed. Of the parameter evaluated; age of patients, type of hydatidiform mole, uterine enlargement, serum hCG level, lutein cyst, and presence of complicating factors were significant risk factors for malignancy after hydatidiform mole were evacuated (p<0.032. The study were done on 50 women diagnosed with hydatidiform mole with 1 year observation (January 2001-December 2002 at the Department of Obstetrics and Gynecology, Mohammad Hoesin Hospital, Palembang. The results showed that the NETDC prognostic index score predicted malignancy in 50% of high risk group and 10% in low risk group (p<0.05. This showed a higher number than that found by the WHO (19%-30%. The risk for incidence of  malignancy after hydatidiform mole in the high risk group is 9.0 times higher compared to that of the low risk group (CI: 1.769-45.786. (Med J Indones 2004; 13: 40-6 Keywords: New England Trophoblastic Disease Center (NETDC, gestational trophoblastic tumor, hydatidiform mole, high and low risk

  13. Investigation of the presence and antinociceptive function of muscarinic acetylcholine receptors in the African naked mole-rat (Heterocephalus glaber).

    Science.gov (United States)

    Jørgensen, Kristine B; Krogh-Jensen, Karen; Pickering, Darryl S; Kanui, Titus I; Abelson, Klas S P

    2016-01-01

    The present study investigated the cholinergic system in the African naked mole-rat (Heterocephalus glaber) with focus on the muscarinic acetylcholine receptor subtypes M1 and M4. The protein sequences for the subtypes m 1-5 of the naked mole-rat were compared to that of the house mouse (Mus musculus) using basic local alignment search tool (BLAST). The presence and function of M1 and M4 was investigated in vivo, using the formalin test with the muscarinic receptor agonists xanomeline and VU0152100. Spinal cord tissue from the naked mole-rat was used for receptor saturation binding studies with [(3)H]-N-methylscopolamine. The BLAST test revealed 95 % protein sequence homology showing the naked mole-rat to have the genetic potential to express all five muscarinic acetylcholine receptor subtypes. A significant reduction in pain behavior was demonstrated after administration of 8.4 mg/kg in the formalin test. Administration of 50 mg/kg VU0152100 resulted in a non-significant tendency towards antinociception. The antinociceptive effects were reversed by the muscarinic acetylcholine receptor antagonist atropine. Binding studies indicated presence of muscarinic acetylcholine receptors with a radioligand affinity comparable to that reported in mice. In conclusion, muscarinic acetylcholine receptor subtypes are present in the naked mole-rat and contribute to antinociception in the naked mole-rat.

  14. Hypofunctional TrkA Accounts for the Absence of Pain Sensitization in the African Naked Mole-Rat.

    Science.gov (United States)

    Omerbašić, Damir; Smith, Ewan St J; Moroni, Mirko; Homfeld, Johanna; Eigenbrod, Ole; Bennett, Nigel C; Reznick, Jane; Faulkes, Chris G; Selbach, Matthias; Lewin, Gary R

    2016-10-11

    The naked mole-rat is a subterranean rodent lacking several pain behaviors found in humans, rats, and mice. For example, nerve growth factor (NGF), an important mediator of pain sensitization, fails to produce thermal hyperalgesia in naked mole-rats. The sensitization of capsaicin-sensitive TRPV1 ion channels is necessary for NGF-induced hyperalgesia, but naked mole-rats have fully functional TRPV1 channels. We show that exposing isolated naked mole-rat nociceptors to NGF does not sensitize TRPV1. However, the naked mole-rat NGF receptor TrkA displays a reduced ability to engage signal transduction pathways that sensitize TRPV1. Between one- and three-amino-acid substitutions in the kinase domain of the naked mole-rat TrkA are sufficient to render the receptor hypofunctional, and this is associated with the absence of heat hyperalgesia. Our data suggest that evolution has selected for a TrkA variant that abolishes a robust nociceptive behavior in this species but is still compatible with species fitness. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  15. Hypofunctional TrkA Accounts for the Absence of Pain Sensitization in the African Naked Mole-Rat

    Directory of Open Access Journals (Sweden)

    Damir Omerbašić

    2016-10-01

    Full Text Available The naked mole-rat is a subterranean rodent lacking several pain behaviors found in humans, rats, and mice. For example, nerve growth factor (NGF, an important mediator of pain sensitization, fails to produce thermal hyperalgesia in naked mole-rats. The sensitization of capsaicin-sensitive TRPV1 ion channels is necessary for NGF-induced hyperalgesia, but naked mole-rats have fully functional TRPV1 channels. We show that exposing isolated naked mole-rat nociceptors to NGF does not sensitize TRPV1. However, the naked mole-rat NGF receptor TrkA displays a reduced ability to engage signal transduction pathways that sensitize TRPV1. Between one- and three-amino-acid substitutions in the kinase domain of the naked mole-rat TrkA are sufficient to render the receptor hypofunctional, and this is associated with the absence of heat hyperalgesia. Our data suggest that evolution has selected for a TrkA variant that abolishes a robust nociceptive behavior in this species but is still compatible with species fitness.

  16. Fractional vector calculus for fractional advection dispersion

    Science.gov (United States)

    Meerschaert, Mark M.; Mortensen, Jeff; Wheatcraft, Stephen W.

    2006-07-01

    We develop the basic tools of fractional vector calculus including a fractional derivative version of the gradient, divergence, and curl, and a fractional divergence theorem and Stokes theorem. These basic tools are then applied to provide a physical explanation for the fractional advection-dispersion equation for flow in heterogeneous porous media.

  17. Genetic signatures for enhanced olfaction in the African mole-rats.

    Directory of Open Access Journals (Sweden)

    Sofia Stathopoulos

    Full Text Available The Olfactory Receptor (OR superfamily, the largest in the vertebrate genome, is responsible for vertebrate olfaction and is traditionally subdivided into 17 OR families. Recent studies characterising whole-OR subgenomes revealed a 'birth and death' model of evolution for a range of species, however little is known about fine-scale evolutionary dynamics within single-OR families. This study reports the first assessment of fine-scale OR evolution and variation in African mole-rats (Bathyergidae, a family of subterranean rodents endemic to sub-Saharan Africa. Because of the selective pressures of life underground, enhanced olfaction is proposed to be fundamental to the evolutionary success of the Bathyergidae, resulting in a highly diversified OR gene-repertoire. Using a PCR-sequencing approach, we analysed variation in the OR7 family across 14 extant bathyergid species, which revealed enhanced levels of functional polymorphisms concentrated across the receptors' ligand-binding region. We propose that mole-rats are able to recognise a broad range of odorants and that this diversity is reflected throughout their OR7 gene repertoire. Using both classic tests and tree-based methods to test for signals of selection, we investigate evolutionary forces across the mole-rat OR7 gene tree. Four well-supported clades emerged in the OR phylogeny, with varying signals of selection; from neutrality to positive and purifying selection. Bathyergid life-history traits and environmental niche-specialisation are explored as possible drivers of adaptive OR evolution, emerging as non-exclusive contributors to the positive selection observed at OR7 genes. Our results reveal unexpected complexity of evolutionary mechanisms acting within a single OR family, providing insightful perspectives into OR evolutionary dynamics.

  18. Multidimensional MRI-CT atlas of the naked mole-rat brain (Heterocephalus glaber).

    Science.gov (United States)

    Seki, Fumiko; Hikishima, Keigo; Nambu, Sanae; Okanoya, Kazuo; Okano, Hirotaka J; Sasaki, Erika; Miura, Kyoko; Okano, Hideyuki

    2013-01-01

    Naked mole-rats have a variety of distinctive features such as the organization of a hierarchical society (known as eusociality), extraordinary longevity, and cancer resistance; thus, it would be worthwhile investigating these animals in detail. One important task is the preparation of a brain atlas database that provide comprehensive information containing multidimensional data with various image contrasts, which can be achievable using a magnetic resonance imaging (MRI). Advanced MRI techniques such as diffusion tensor imaging (DTI), which generates high contrast images of fiber structures, can characterize unique morphological properties in addition to conventional MRI. To obtain high spatial resolution images, MR histology, DTI, and X-ray computed tomography were performed on the fixed adult brain. Skull and brain structures were segmented as well as reconstructed in stereotaxic coordinates. Data were also acquired for the neonatal brain to allow developmental changes to be observed. Moreover, in vivo imaging of naked mole-rats was established as an evaluation tool of live animals. The data obtained comprised three-dimensional (3D) images with high tissue contrast as well as stereotaxic coordinates. Developmental differences in the visual system were highlighted in particular by DTI. Although it was difficult to delineate optic nerves in the mature adult brain, parts of them could be distinguished in the immature neonatal brain. From observation of cortical thickness, possibility of high somatosensory system development replaced to the visual system was indicated. 3D visualization of brain structures in the atlas as well as the establishment of in vivo imaging would promote neuroimaging researches towards detection of novel characteristics of eusocial naked mole-rats.

  19. Multidimensional MRI-CT atlas of the naked mole-rat brain

    Directory of Open Access Journals (Sweden)

    Fumiko eSeki

    2013-12-01

    Full Text Available Naked mole-rats have a variety of distinctive features such as the organisation of a hierarchical society (known as eusociality, extraordinary longevity, and cancer resistance; thus, it would be worthwhile investigating these animals in detail. One important task is the preparation of a brain atlas database that provide comprehensive information containing multidimensional data with various image contrasts, which can be achievable using a magnetic resonance imaging (MRI. Advanced MRI techniques such as diffusion tensor imaging (DTI, which generates high contrast images of fibre structures, can characterise unique morphological properties in addition to conventional MRI. To obtain high spatial resolution images, MR histology, DTI, and X-ray computed tomography (CT were performed on the fixed adult brain. Skull and brain structures were segmented as well as reconstructed in stereotaxic coordinates. Data were also acquired for the neonatal brain to allow developmental changes to be observed. Moreover, in vivo imaging of naked mole-rats was established as an evaluation tool of live animals. The data obtained comprised three-dimensional (3D images with high tissue contrast as well as stereotaxic coordinates. Developmental differences in the visual system were highlighted in particular by DTI. Although it was difficult to delineate optic nerves in the mature adult brain, parts of them could be distinguished in the immature neonatal brain. From observation of cortical thickness, possibility of high somatosensory system development replaced to the visual system was indicated. 3D visualisation of brain structures in the atlas as well as the establishment of in vivo imaging would promote neuroimaging researches towards detection of novel characteristics of eusocial naked mole-rats.

  20. Fractional Schroedinger equation

    International Nuclear Information System (INIS)

    Laskin, Nick

    2002-01-01

    Some properties of the fractional Schroedinger equation are studied. We prove the Hermiticity of the fractional Hamilton operator and establish the parity conservation law for fractional quantum mechanics. As physical applications of the fractional Schroedinger equation we find the energy spectra of a hydrogenlike atom (fractional 'Bohr atom') and of a fractional oscillator in the semiclassical approximation. An equation for the fractional probability current density is developed and discussed. We also discuss the relationships between the fractional and standard Schroedinger equations

  1. A study on vapor explosions

    International Nuclear Information System (INIS)

    Takagi, N.; Shoji, M.

    1979-01-01

    An experimental study was carried out for vapor explosions of molten tin falling in water. For various initial metal temperatures and subcooling of water, transient pressure of the explosions, relative frequency of the explosions and the position where the explosions occur were measured in detail. The influence of ambient pressure was also investigated. From the results, it was concluded that the vapor explosion is closely related to the collapse of a vapor film around the molten metal. (author)

  2. Naked mole-rat acid-sensing ion channel 3 forms nonfunctional homomers, but functional heteromers.

    Science.gov (United States)

    Schuhmacher, Laura-Nadine; Callejo, Gerard; Srivats, Shyam; Smith, Ewan St John

    2018-02-02

    Acid-sensing ion channels (ASICs) form both homotrimeric and heterotrimeric ion channels that are activated by extracellular protons and are involved in a wide range of physiological and pathophysiological processes, including pain and anxiety. ASIC proteins can form both homotrimeric and heterotrimeric ion channels. The ASIC3 subunit has been shown to be of particular importance in the peripheral nervous system with pharmacological and genetic manipulations demonstrating a role in pain. Naked mole-rats, despite having functional ASICs, are insensitive to acid as a noxious stimulus and show diminished avoidance of acidic fumes, ammonia, and carbon dioxide. Here we cloned naked mole-rat ASIC3 (nmrASIC3) and used a cell-surface biotinylation assay to demonstrate that it traffics to the plasma membrane, but using whole-cell patch clamp electrophysiology we observed that nmrASIC3 is insensitive to both protons and the non-proton ASIC3 agonist 2-guanidine-4-methylquinazoline. However, in line with previous reports of ASIC3 mRNA expression in dorsal root ganglia neurons, we found that the ASIC3 antagonist APETx2 reversibly inhibits ASIC-like currents in naked mole-rat dorsal root ganglia neurons. We further show that like the proton-insensitive ASIC2b and ASIC4, nmrASIC3 forms functional, proton-sensitive heteromers with other ASIC subunits. An amino acid alignment of ASIC3s between 9 relevant rodent species and human identified unique sequence differences that might underlie the proton insensitivity of nmrASIC3. However, introducing nmrASIC3 differences into rat ASIC3 (rASIC3) produced only minor differences in channel function, and replacing the nmrASIC3 sequence with that of rASIC3 did not produce a proton-sensitive ion channel. Our observation that nmrASIC3 forms nonfunctional homomers may reflect a further adaptation of the naked mole-rat to living in an environment with high-carbon dioxide levels. © 2018 by The American Society for Biochemistry and Molecular

  3. Ultrasound imaging of partial hydatidiform mole in the second trimester of pregnancy

    International Nuclear Information System (INIS)

    Jover Labiste, Marina

    2012-01-01

    The case report of a 27 year-old patient with 18 weeks gestation, admitted to the Obstetrics Department of 'Mariana Grajales Coello' Provincial Gynecology and Obstetrics Hospital of Santiago de Cuba due to high blood pressure, cephalea and pain in lower abdomen is described. Additional tests confirmed a partial hydatidiform mole, so that uterine curettage was performed and small fragments of endometrial stroma were removed for pathological study. Outpatient medical monitoring was recommended and the patient had an appointment at 21 days for controlling and evaluating her general state

  4. Predictive value of some hematological parameters for non-invasive and invasive mole pregnancies.

    Science.gov (United States)

    Abide Yayla, Cigdem; Özkaya, Enis; Yenidede, Ilter; Eser, Ahmet; Ergen, Evrim Bostancı; Tayyar, Ahter Tanay; Şentürk, Mehmet Baki; Karateke, Ates

    2018-02-01

    The aim of this study was to discriminate mole pregnancies and invasive forms among cases with first trimester vaginal bleeding by the utilization of some complete blood count parameters conjunct to sonographic findings and beta human chorionic gonadotropin concentration. Consecutive 257 cases with histopathologically confirmed mole pregnancies and 199 women without mole pregnancy presented with first trimester vaginal bleeding who admitted to Zeynep Kamil Women and Children's Health Training Hospital between January 2012 and January 2016 were included in this cross-sectional study. The serum beta HCG level at presentation, and beta hCG levels at 1st, 2nd and 3rd weeks of postevacuation with some parameters of complete blood count were utilized to discriminate cases with molar pregnancy and cases with invasive mole among first trimester pregnants presented with vaginal bleeding and abnormal sonographic findings. Levels of beta hCG at baseline (AUC = 0.700, p < 0.05) and 1st (AUC = 0.704, p < 0.05), 2nd (AUC = 0.870, p < 0.001) and 3rd (AUC = 0.916, p < 0.001) weeks of postevacuation period were significant predictors for the cases with persistent disease. While area under curve for mean platelet volume is 0.715, it means that mean platelet volume has 21.5% additional diagnostic value for predicting persistency in molar patients. For 8.55 cut-off point for mean platelet volume, sensitivity is 84.6% and specificity is 51.6%. Area under curve for platelet/lymphocyte ratio is 0.683 means that platelet/lymphocyte ratio has additional 18.3% diagnostic value. For 102.25 cut-off point sensitivity is 86.6% and specificity is 46.2. Simple, widely available complete blood count parameters may be used as an adjunct to other risk factors to diagnose molar pregnancies and predict postevacuation trophoblastic disease.

  5. Meadow based Fraction Theory

    OpenAIRE

    Bergstra, Jan A.

    2015-01-01

    In the context of an involutive meadow a precise definition of fractions is formulated and on that basis formal definitions of various classes of fractions are given. The definitions follow the fractions as terms paradigm. That paradigm is compared with two competing paradigms for storytelling on fractions: fractions as values and fractions as pairs.

  6. Influence of soil properties on vapor-phase sorption of trichloroethylene

    International Nuclear Information System (INIS)

    Bekele, Dawit N.; Naidu, Ravi; Chadalavada, Sreenivasulu

    2016-01-01

    Highlights: • Vapor intrusion is a major exposure pathway for volatile hydrocarbons. • Certainty in transport processes enhances vapor intrusion model precision. • Detailed understanding of vadose zone vapor transport processes save resources. • Vapor sorption near-steady-state conditions at sites may take months or years. • Type of clay fractions equitably affects sorption of trichloroethylene vapor. - Abstract: Current practices in health risk assessment from vapor intrusion (VI) using mathematical models are based on assumptions that the subsurface sorption equilibrium is attained. The time required for sorption to reach near-steady-state conditions at sites may take months or years to achieve. This study investigated the vapor phase attenuation of trichloroethylene (TCE) in five soils varying widely in clay and organic matter content using repacked columns. The primary indicators of TCE sorption were vapor retardation rate (R_t), the time required for the TCE vapor to pass through the soil column, and specific volume of retention (V_R), and total volume of TCE retained in soil. Results show TCE vapor retardation is mainly due to the rapid partitioning of the compound to SOM. However, the specific volume of retention of clayey soils with secondary mineral particles was higher. Linear regression analyses of the SOM and clay fraction with V_R show that a unit increase in clay fraction results in higher sorption of TCE (V_R) than the SOM. However, partitioning of TCE vapor was not consistent with the samples' surface areas but was mainly a function of the type of secondary minerals present in soils.

  7. Influence of soil properties on vapor-phase sorption of trichloroethylene

    Energy Technology Data Exchange (ETDEWEB)

    Bekele, Dawit N. [Global Center for Environmental Remediation, University of Newcastle, Callaghan, NSW 2308 (Australia); CRC for Contamination Assessment & Remediation of the Environment, Building X (Environmental Sciences Building), University of South Australia, Mawson Lakes, SA 5095 (Australia); Naidu, Ravi, E-mail: Ravi.Naidu@newcastle.edu.au [Global Center for Environmental Remediation, University of Newcastle, Callaghan, NSW 2308 (Australia); CRC for Contamination Assessment & Remediation of the Environment, Building X (Environmental Sciences Building), University of South Australia, Mawson Lakes, SA 5095 (Australia); Chadalavada, Sreenivasulu [Global Center for Environmental Remediation, University of Newcastle, Callaghan, NSW 2308 (Australia); CRC for Contamination Assessment & Remediation of the Environment, Building X (Environmental Sciences Building), University of South Australia, Mawson Lakes, SA 5095 (Australia)

    2016-04-05

    Highlights: • Vapor intrusion is a major exposure pathway for volatile hydrocarbons. • Certainty in transport processes enhances vapor intrusion model precision. • Detailed understanding of vadose zone vapor transport processes save resources. • Vapor sorption near-steady-state conditions at sites may take months or years. • Type of clay fractions equitably affects sorption of trichloroethylene vapor. - Abstract: Current practices in health risk assessment from vapor intrusion (VI) using mathematical models are based on assumptions that the subsurface sorption equilibrium is attained. The time required for sorption to reach near-steady-state conditions at sites may take months or years to achieve. This study investigated the vapor phase attenuation of trichloroethylene (TCE) in five soils varying widely in clay and organic matter content using repacked columns. The primary indicators of TCE sorption were vapor retardation rate (R{sub t}), the time required for the TCE vapor to pass through the soil column, and specific volume of retention (V{sub R}), and total volume of TCE retained in soil. Results show TCE vapor retardation is mainly due to the rapid partitioning of the compound to SOM. However, the specific volume of retention of clayey soils with secondary mineral particles was higher. Linear regression analyses of the SOM and clay fraction with V{sub R} show that a unit increase in clay fraction results in higher sorption of TCE (V{sub R}) than the SOM. However, partitioning of TCE vapor was not consistent with the samples' surface areas but was mainly a function of the type of secondary minerals present in soils.

  8. Nuclear system vaporization

    International Nuclear Information System (INIS)

    Bougault, R.; Brou, R.; Colin, J.; Cussol, D.; Durand, D.; Le Brun, C.; Lecolley, J.F.; Lopez, O.; Louvel, M.; Nakagawa, T.; Peter, J.; Regimbart, R.; Steckmeyer, J.C.; Tamain, B.; Vient, E.; Yuasa-Nakagawa, K.; Wieloch, A.

    1998-01-01

    A particular case of the hot nuclei de-excitation is the total nuclear dislocation into light particles (n, p, d, t, 3 He and α). Such events were first observed at bombarding energies lower than 100 MeV/nucleon due to high detection performances of the INDRA multidetector. The light system Ar + Ni was studied at several bombarding energies ranging from 32 to 95 MeV/nucleon. The events associated to a total vaporization of the system occur above the energy threshold of ∼ 50 MeV/nucleon. A study of the form of these events shows that we have essentially two sources. The excitation energy of these sources may be determined by means of the kinematic properties of their de-excitation products. A preliminary study results in excitation energy values of the order 10 - 14 MeV/nucleon. The theoretical calculation based on a statistical model modified to take into account high excitation energies and excited levels in the lightest nuclei predicts that the vaporization of the two partner nuclei in the Ar + Ni system takes place when the excitation energy exceeds 12 MeV/nucleon what is qualitatively in agreement with the values deduced from calorimetric analysis

  9. Process and apparatus for fractionating close-boiling components of a multi-component system

    International Nuclear Information System (INIS)

    Tsao, U.

    1983-01-01

    A process and apparatus are described for the fractionation of close-boiling components of a multi-component system comprising at least two fractionation columns A, B in series having a plurality of equilibrium stages in which the vapor stream from a downstream fractionation column B is compressed by a compressor and passed into a lower portion of a preceding fractionation column A and a liquid bottom stream from any one of said columns except the last is expanded by an orifice sufficiently to convey the resulting liquid-vapor mixture to the upper portion of the next fractionation column B. In a particularly preferred embodiment, the compressed overhead vapor stream is passed in heat transfer relationship to a liquid stream withdrawn from the preceding fractionation column A prior to introduction into the lower portion of such preceding fractionation column A. In one of the claims, the multi-component close-boiling system is a deuterium oxide-water solution. (author)

  10. Hydrogen isotopic fractionation during crystallization of the terrestrial magma ocean

    Science.gov (United States)

    Pahlevan, K.; Karato, S. I.

    2016-12-01

    Models of the Moon-forming giant impact extensively melt and partially vaporize the silicate Earth and deliver a substantial mass of metal to the Earth's core. The subsequent evolution of the terrestrial magma ocean and overlying vapor atmosphere over the ensuing 105-6 years has been largely constrained by theoretical models with remnant signatures from this epoch proving somewhat elusive. We have calculated equilibrium hydrogen isotopic fractionation between the magma ocean and overlying steam atmosphere to determine the extent to which H isotopes trace the evolution during this epoch. By analogy with the modern silicate Earth, the magma ocean-steam atmosphere system is often assumed to be chemically oxidized (log fO2 QFM) with the dominant atmospheric vapor species taken to be water vapor. However, the terrestrial magma ocean - having held metallic droplets in suspension - may also exhibit a much more reducing character (log fO2 IW) such that equilibration with the overlying atmosphere renders molecular hydrogen the dominant H-bearing vapor species. This variable - the redox state of the magma ocean - has not been explicitly included in prior models of the coupled evolution of the magma ocean-steam atmosphere system. We find that the redox state of the magma ocean influences not only the vapor speciation and liquid-vapor partitioning of hydrogen but also the equilibrium isotopic fractionation during the crystallization epoch. The liquid-vapor isotopic fractionation of H is substantial under reducing conditions and can generate measurable D/H signatures in the crystallization products but is largely muted in an oxidizing magma ocean and steam atmosphere. We couple equilibrium isotopic fractionation with magma ocean crystallization calculations to forward model the behavior of hydrogen isotopes during this epoch and find that the distribution of H isotopes in the silicate Earth immediately following crystallization represents an oxybarometer for the terrestrial

  11. Absence of histamine-induced itch in the African naked mole-rat and "rescue" by Substance P.

    Science.gov (United States)

    Smith, Ewan St John; Blass, Gregory R C; Lewin, Gary R; Park, Thomas J

    2010-05-24

    Recent research has proposed a pathway in which sensory neurons expressing the capsaicin activated ion channel TRPV1 are required for histamine-induced itch and subsequent scratching behavior. We examined histamine-induced itch in the African naked mole-rat (Heterocephalus glaber) and found that although naked mole-rats display innate scratching behavior, histamine was unable to evoke increased scratching as is observed in most mouse strains. Using calcium imaging, we examined the histamine sensitivity of naked mole-rat dorsal root ganglia (DRG) neurons and identified a population of small diameter neurons activated by histamine, the majority of which are also capsaicin-sensitive. This suggested that naked mole-rat sensory neurons are activated by histamine, but that spinal dorsal horn processing of sensory information is not the same as in other rodents. We have previously shown that naked mole-rats naturally lack substance P (SP) in cutaneous C-fibers, but that the neurokinin-1 receptor is expressed in the superficial spinal cord. This led us to investigate if SP deficiency plays a role in the lack of histamine-induced scratching in this species. After intrathecal administration of SP into the spinal cord we observed robust scratching behavior in response to histamine injection. Our data therefore support a model in which TRPV1-expressing sensory neurons are important for histamine-induced itch. In addition, we demonstrate a requirement for active, SP-induced post-synaptic drive to enable histamine sensitive afferents to drive itch-related behavior in the naked mole-rat. These results illustrate that it is altered dorsal horn connectivity of nociceptors that underlies the lack of itch and pain-related behavior in the naked mole-rat.

  12. Absence of histamine-induced itch in the African naked mole-rat and "rescue" by Substance P

    Directory of Open Access Journals (Sweden)

    Lewin Gary R

    2010-05-01

    Full Text Available Abstract Recent research has proposed a pathway in which sensory neurons expressing the capsaicin activated ion channel TRPV1 are required for histamine-induced itch and subsequent scratching behavior. We examined histamine-induced itch in the African naked mole-rat (Heterocephalus glaber and found that although naked mole-rats display innate scratching behavior, histamine was unable to evoke increased scratching as is observed in most mouse strains. Using calcium imaging, we examined the histamine sensitivity of naked mole-rat dorsal root ganglia (DRG neurons and identified a population of small diameter neurons activated by histamine, the majority of which are also capsaicin-sensitive. This suggested that naked mole-rat sensory neurons are activated by histamine, but that spinal dorsal horn processing of sensory information is not the same as in other rodents. We have previously shown that naked mole-rats naturally lack substance P (SP in cutaneous C-fibers, but that the neurokinin-1 receptor is expressed in the superficial spinal cord. This led us to investigate if SP deficiency plays a role in the lack of histamine-induced scratching in this species. After intrathecal administration of SP into the spinal cord we observed robust scratching behavior in response to histamine injection. Our data therefore support a model in which TRPV1-expressing sensory neurons are important for histamine-induced itch. In addition, we demonstrate a requirement for active, SP-induced post-synaptic drive to enable histamine sensitive afferents to drive itch-related behavior in the naked mole-rat. These results illustrate that it is altered dorsal horn connectivity of nociceptors that underlies the lack of itch and pain-related behavior in the naked mole-rat.

  13. MOLE: A Multidisciplinary Observatory and Laboratory of Experiments in Central Italy

    Directory of Open Access Journals (Sweden)

    Georg Dresen

    2009-03-01

    Full Text Available The structure and mechanics of active Low Angle Normal Faults (LANFs have for decades b s been posing questions—in particular, if low angle normal faults accommodate crustal extension, and if they generate large magnitude earthquakes, or if they move aseismically. To shed new light on these challenging questions, MOLE intends to drill (down to 4–5 km an active LANF in the Umbria-Marche sector of the northern Apennines (Fig. 1 and to establish a deep borehole observatory. The target site offers a unique opportunity to reach a LANF at drillable seismogenic depth to unravel the “low angle normal fault mechanical paradox” (Wernicke, 1995; Axen, 2007. In order to discuss the scientific background and plan the MOLE project, ixty-two scientists from various research fields attended an international workshop in Spoleto, Italy, on 5–8 May 2008. The workshop focused on the following goals that need to be achieved: (I to collect new observational data at depth for constraining the fault zone structure; (II to perform laboratory experiments with gouge and fault zone materials to understand frictional properties and weakeningmechanisms; (III to record microearthquakes at distance comparable to the source radius, and (IV to obtain stress and strain measurements and geochemical data in and near the fault zone at depth to understand the mechanics of earthquakes and faulting.

  14. Dominance and queen succession in captive colonies of the eusocial naked mole-rat, Heterocephalus glaber.

    Science.gov (United States)

    Clarke, F M; Faulkes, C G

    1997-07-22

    Naked mole-rat colonies exhibit a high reproductive skew, breeding being typically restricted to one female (the 'queen') and one to three males. Other colony members are reproductively suppressed, although this suppression can be reversed following the removal or death of the queen. We examined dominance and queen succession within captive colonies to investigate the relationship between urinary testosterone and cortisol, dominance rank and reproductive status; and to determine if behavioural and/or physiological parameters can be used as predictors of queen succession. Social structure was characterized by a linear dominance hierarchy before and after queen removal. Prior to queen removal, dominance rank was negatively correlated with body weight and urinary testosterone and cortisol titres in males and females. Queen removal results in social instability and aggression between high ranking individuals. Dominance rank appears to be a good predictor of reproductive status: queens are the highest ranking colony females and are succeeded by the next highest ranking females. The intense dominance-related aggression that accompanies reproductive succession in naked mole-rats provides empirical support for optimal skew theory.

  15. Adaptations to a Subterranean Environment and Longevity Revealed by the Analysis of Mole Rat Genomes

    Directory of Open Access Journals (Sweden)

    Xiaodong Fang

    2014-09-01

    Full Text Available Subterranean mammals spend their lives in dark, unventilated environments that are rich in carbon dioxide and ammonia and low in oxygen. Many of these animals are also long-lived and exhibit reduced aging-associated diseases, such as neurodegenerative disorders and cancer. We sequenced the genome of the Damaraland mole rat (DMR, Fukomys damarensis and improved the genome assembly of the naked mole rat (NMR, Heterocephalus glaber. Comparative genome analyses, along with the transcriptomes of related subterranean rodents, revealed candidate molecular adaptations for subterranean life and longevity, including a divergent insulin peptide, expression of oxygen-carrying globins in the brain, prevention of high CO2-induced pain perception, and enhanced ammonia detoxification. Juxtaposition of the genomes of DMR and other more conventional animals with the genome of NMR revealed several truly exceptional NMR features: unusual thermogenesis, an aberrant melatonin system, pain insensitivity, and unique processing of 28S rRNA. Together, these genomes and transcriptomes extend our understanding of subterranean adaptations, stress resistance, and longevity.

  16. Androgen receptor distribution in the social decision-making network of eusocial naked mole-rats.

    Science.gov (United States)

    Holmes, Melissa M; Van Mil, Spencer; Bulkowski, Camila; Goldman, Sharry L; Goldman, Bruce D; Forger, Nancy G

    2013-11-01

    Naked mole-rats are highly social rodents that live in large groups and exhibit a strict reproductive and social hierarchy. Only a few animals in each colony breed; the remainder are non-reproductive and are socially subordinate to breeders. We have examined androgen receptor immunoreactive (AR+) cells in brain regions comprising the recently described social decision-making network in subordinate and breeder naked mole-rats of both sexes. We find that subordinates have a significantly higher percentage of AR+ cells in all brain regions expressing this protein. By contrast, there were no significant effects of sex and no sex-by-status interactions on the percentage of AR+ cells. Taken together with previous findings, the present data complete a systematic assessment of the distribution of AR protein in the social decision-making network of the eusocial mammalian brain and demonstrate a significant role for social status in the regulation of this protein throughout many nodes of this network. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. Differential effects of chronic fluoxetine on the behavior of dominant and subordinate naked mole-rats.

    Science.gov (United States)

    Mongillo, Daniel L; Kosyachkova, Ekaterina A; Nguyen, Tam M; Holmes, Melissa M

    2014-01-01

    Naked mole-rats are eusocial rodents that live in large subterranean colonies with a strict reproductive and social hierarchy. The breeding female (referred to as the queen) and 1 to 3 breeding males are the only reproductive members of the colony. Breeders are socially dominant and all other colony members are non-reproductive subordinates. The effects of manipulating the serotonergic neurotransmitter system on aggression and dominance behaviors are well studied in many species, but not in eusocial rodents like the naked mole-rat. The current study investigated how the serotonergic system influences aggressive/dominant behaviors in this species. To do this, two separate but related experiments were conducted: the effects of fluoxetine hydrochloride (FLX) on status-specific behaviors of subordinates (Experiment 1) and dominant queens (Experiment 2) were evaluated both in-colony and in a social-pairing paradigm. In accordance with our main hypothesis, chronic treatment of FLX attenuated the frequency and duration of aggression in queens, but not subordinates, when paired with an unfamiliar conspecific. Further exploration of pharmacological manipulation on status-specific behaviors of this eusocial species may elucidate the neurobiological mechanisms underlying their unique and rigid social hierarchy. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. Retinal ganglion cell survival and axon regeneration after optic nerve injury in naked mole-rats.

    Science.gov (United States)

    Park, Kevin K; Luo, Xueting; Mooney, Skyler J; Yungher, Benjamin J; Belin, Stephane; Wang, Chen; Holmes, Melissa M; He, Zhigang

    2017-02-01

    In the adult mammalian central nervous system (CNS), axonal damage often triggers neuronal cell death and glial activation, with very limited spontaneous axon regeneration. In this study, we performed optic nerve injury in adult naked mole-rats, the longest living rodent, with a maximum life span exceeding 30 years, and found that injury responses in this species are quite distinct from those in other mammalian species. In contrast to what is seen in other mammals, the majority of injured retinal ganglion cells (RGCs) survive with relatively high spontaneous axon regeneration. Furthermore, injured RGCs display activated signal transducer and activator of transcription-3 (STAT3), whereas astrocytes in the optic nerve robustly occupy and fill the lesion area days after injury. These neuron-intrinsic and -extrinsic injury responses are reminiscent of those in "cold-blooded" animals, such as fish and amphibians, suggesting that the naked mole-rat is a powerful model for exploring the mechanisms of neuronal injury responses and axon regeneration in mammals. J. Comp. Neurol. 525:380-388, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  19. Endocrine function and neurobiology of the longest-living rodent, the naked mole-rat.

    Science.gov (United States)

    Edrey, Yael H; Park, Thomas J; Kang, Hyesin; Biney, Adriana; Buffenstein, Rochelle

    2011-01-01

    Animals that have evolved exceptional capabilities, such as extraordinary longevity may reveal pertinent and potentially critical insights into biomedical research that are not readily apparent in standard laboratory animals. Naked mole-rats (Heterocephalus glaber; NMRs) are extremely long-lived (30 years) mouse-sized rodents. They clearly have evolved superior anti-aging mechanisms as evident by the markedly attenuated age-related decline in physiological function, sustained reproductive capacity and pronounced cancer resistance throughout their long-lives. These eusocial rodents, like the social insects, live in colonies with breeding restricted to one female and a few males. Subordinates are sexually monomorphic, yet retain the ability to become breeders, and can undergo growth surges and neural modifications at any time throughout their life. This plasticity in physiological and behavioral aspects may have contributed to their long-lives. Naked mole-rats show numerous adaptations to life underground including extreme tolerance of hypoxia, acid insensitivity, as well as independence of photoendocrine systems. Here we review what is known about their unique social structure, sensory systems, endocrinology and neurobiology, and highlight areas that may be pertinent to biogerontology. Copyright © 2010 Elsevier Inc. All rights reserved.

  20. Calculation of Steam Volume Fraction in Subcooled Boiling

    Energy Technology Data Exchange (ETDEWEB)

    Rouhani, S Z

    1967-06-15

    An analysis of subcooled boiling is presented. It is assumed that heat is removed by vapor generation, heating of the liquid that replaces the detached bubbles, and to some extent by single phase heat transfer. Two regions of subcooled boiling are considered and a criterion is provided for obtaining the limiting value of subcooling between the two regions. Condensation of vapor in the subcooled liquid is analysed and the relative velocity of vapor with respect to the liquid is neglected in these regions. The theoretical arguments result in some equations for the calculation of steam volume fraction and true liquid subcooling.

  1. Prediction of the critical reduced electric field strength for carbon dioxide and its mixtures with copper vapor from Boltzmann analysis for a gas temperature range of 300 K to 4000 K at 0.4 MPa

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xingwen, E-mail: xwli@mail.xjtu.edu.cn; Guo, Xiaoxue; Zhao, Hu; Jia, Shenli [State Key Laboratory of Electrical Insulation and Power Equipment, Xi' an Jiaotong University, No. 28 XianNing West Road, Xi' an, Shaanxi Province 710049 (China); Murphy, Anthony B. [CSIRO Manufacturing Flagship, PO Box 218, Lindfield NSW 2070 (Australia)

    2015-04-14

    The influence of copper vapor mixed in hot CO{sub 2} on dielectric breakdown properties of gas mixture at a fixed pressure of 0.4 MPa for a temperature range of 300 K–4000 K is numerically analyzed. First, the equilibrium composition of hot CO{sub 2} with different copper fractions is calculated using a method based on mass action law. The next stage is devoted to computing the electron energy distribution functions (EEDF) by solving the two-term Boltzmann equation. The reduced ionization coefficient, the reduced attachment coefficient, and the reduced effective ionization coefficient are then obtained based on the EEDF. Finally, the critical reduced electric field (E/N){sub cr} is obtained. The results indicate that an increasing mole fraction of copper markedly reduces (E/N){sub cr} of the CO{sub 2}–Cu gas mixtures because of copper's low ionization potential and large ionization cross section. Additionally, the generation of O{sub 2} from the thermal dissociation of CO{sub 2} contributes to the increase of (E/N){sub cr} of CO{sub 2}–Cu hot gas mixtures from about 2000 K to 3500 K.

  2. Chemical vapor composites (CVC)

    International Nuclear Information System (INIS)

    Reagan, P.

    1993-01-01

    The Chemical Vapor Composite, CVC trademark , process fabricates composite material by simply mixing particles (powders and or fibers) with CVD reactants which are transported and co-deposited on a hot substrate. A key feature of the CVC process is the control provided by varing the density, geometry (aspect ratio) and composition of the entrained particles in the matrix material, during deposition. The process can fabricate composite components to net shape (± 0.013 mm) on a machined substrate in a single step. The microstructure of the deposit is described and several examples of different types of particles in the matrix are illustrated. Mechanical properties of SiC composite material fabricated with SiC powder and fiber will be presented. Several examples of low cost ceramic composite products will be shown. (orig.)

  3. Iron bromide vapor laser

    Science.gov (United States)

    Sukhanov, V. B.; Shiyanov, D. V.; Trigub, M. V.; Dimaki, V. A.; Evtushenko, G. S.

    2016-03-01

    We have studied the characteristics of a pulsed gas-discharge laser on iron bromide vapor generating radiation with a wavelength of 452.9 nm at a pulse repetition frequency (PRF) of 5-30 kHz. The maximum output power amounted to 10 mW at a PRF within 5-15 kHz for a voltage of 20-25 kV applied to electrodes of the discharge tube. Addition of HBr to the medium produced leveling of the radial profile of emission. Initial weak lasing at a wavelength of 868.9 nm was observed for the first time, which ceased with buildup of the main 452.9-nm line.

  4. Vapor-droplet flow equations

    International Nuclear Information System (INIS)

    Crowe, C.T.

    1975-01-01

    General features of a vapor-droplet flow are discussed and the equations expressing the conservation of mass, momentum, and energy for the vapor, liquid, and mixture using the control volume approach are derived. The phenomenological laws describing the exchange of mass, momentum, and energy between phases are also reviewed. The results have application to development of water-dominated geothermal resources

  5. A stable algorithm for calculating phase equilibria with capillarity at specified moles, volume and temperature using a dynamic model

    KAUST Repository

    Kou, Jisheng

    2017-09-30

    Capillary pressure can significantly affect the phase properties and flow of liquid-gas fluids in porous media, and thus, the phase equilibrium calculation incorporating capillary pressure is crucial to simulate such problems accurately. Recently, the phase equilibrium calculation at specified moles, volume and temperature (NVT-flash) becomes an attractive issue. In this paper, capillarity is incorporated into the phase equilibrium calculation at specified moles, volume and temperature. A dynamical model for such problem is developed for the first time by using the laws of thermodynamics and Onsager\\'s reciprocal principle. This model consists of the evolutionary equations for moles and volume, and it can characterize the evolutionary process from a non-equilibrium state to an equilibrium state in the presence of capillarity effect at specified moles, volume and temperature. The phase equilibrium equations are naturally derived. To simulate the proposed dynamical model efficiently, we adopt the convex-concave splitting of the total Helmholtz energy, and propose a thermodynamically stable numerical algorithm, which is proved to preserve the second law of thermodynamics at the discrete level. Using the thermodynamical relations, we derive a phase stability condition with capillarity effect at specified moles, volume and temperature. Moreover, we propose a stable numerical algorithm for the phase stability testing, which can provide the feasible initial conditions. The performance of the proposed methods in predicting phase properties under capillarity effect is demonstrated on various cases of pure substance and mixture systems.

  6. Community structure variability of Uropodina mites (Acari: Mesostigmata) in nests of the common mole, Talpa europaea, in Central Europe.

    Science.gov (United States)

    Napierała, Agnieszka; Mądra, Anna; Leszczyńska-Deja, Kornelia; Gwiazdowicz, Dariusz J; Gołdyn, Bartłomiej; Błoszyk, Jerzy

    2016-04-01

    Underground nests of Talpa europaea, known as the common mole, are very specific microhabitats, which are also quite often inhabited by various groups of arthropods. Mites from the suborder Uropodina (Acari: Mesostigmata) are only one of them. One could expect that mole nests that are closely located are inhabited by communities of arthropods with similar species composition and structure. However, results of empirical studies clearly show that even nests which are close to each other can be different both in terms of the species composition and abundance of Uropodina communities. So far, little is known about the factors that can cause these differences. The major aim of this study was to identify factors determining species composition, abundance, and community structure of Uropodina communities in mole nests. The study is based on material collected during a long-term investigation conducted in western parts of Poland. The results indicate that the two most important factors influencing species composition and abundance of Uropodina communities in mole nests are nest-building material and depth at which nests are located. Composition of Uropodina communities in nests of moles was also compared with that of other microhabitats (e.g. rotten wood, forest litter, soil) based on data from 4421 samples collected in Poland. Communities of this habitat prove most similar to these of open areas, especially meadows, as well as some forest types.

  7. Fractional Vector Calculus and Fractional Special Function

    OpenAIRE

    Li, Ming-Fan; Ren, Ji-Rong; Zhu, Tao

    2010-01-01

    Fractional vector calculus is discussed in the spherical coordinate framework. A variation of the Legendre equation and fractional Bessel equation are solved by series expansion and numerically. Finally, we generalize the hypergeometric functions.

  8. Evaporation rate and vapor pressure of selected polymeric lubricating oils.

    Science.gov (United States)

    Gardos, M. N.

    1973-01-01

    A recently developed ultrahigh-vacuum quartz spring mass sorption microbalance has been utilized to measure the evaporation rates of several low-volatility polymeric lubricating oils at various temperatures. The evaporation rates are used to calculate the vapor pressures by the Langmuir equation. A method is presented to accurately estimate extended temperature range evaporation rate and vapor pressure data for polymeric oils, incorporating appropriate corrections for the increases in molecular weight and the change in volatility of the progressively evaporating polymer fractions. The logarithms of the calculated data appear to follow linear relationships within the test temperature ranges, when plotted versus 1000/T. These functions and the observed effusion characteristics of the fluids on progressive volatilization are useful in estimating evaporation rate and vapor pressure changes on evaporative depletion.

  9. Vapor pressure and enthalpy of vaporization of aliphatic propanediamines

    International Nuclear Information System (INIS)

    Verevkin, Sergey P.; Chernyak, Yury

    2012-01-01

    Highlights: ► We measured vapor pressure of four aliphatic 1,3-diamines. ► Vaporization enthalpies at 298 K were derived. ► We examined consistency of new and available data in the literature. ► A group-contribution method for prediction was developed. - Abstract: Vapor pressures of four aliphatic propanediamines including N-methyl-1,3-propanediamine (MPDA), N,N-dimethyl-1,3-propanediamine (DMPDA), N,N-diethyl-1,3-propanediamine (DEPDA) and N,N,N′,N′-tetramethyl-1,3-propanediamine (4MPDA) were measured using the transpiration method. The vapor pressures developed in this work and reported in the literature were used to derive molar enthalpy of vaporization values at the reference temperature 298.15 K. An internal consistency check of the enthalpy of vaporization was performed for the aliphatic propanediamines studied in this work. A group-contribution method was developed for the validation and prediction vaporization enthalpies of amines and diamines.

  10. A Citizen's Guide to Vapor Intrusion Mitigation

    Science.gov (United States)

    This guide describes how vapor intrusion is the movement of chemical vapors from contaminated soil and groundwater into nearby buildings.Vapors primarily enter through openings in the building foundation or basement walls.

  11. Vapor pressure measured with inflatable plastic bag

    Science.gov (United States)

    1965-01-01

    Deflated plastic bag in a vacuum chamber measures initial low vapor pressures of materials. The bag captures the test sample vapors and visual observation of the vapor-inflated bag under increasing external pressures yields pertinent data.

  12. Investigation on energetics of ex-vessel vapor explosion based on spontaneous nucleation fragmentation

    International Nuclear Information System (INIS)

    Liu, Jie; Koshizuka, Seiichi; Oka, Yoshiaki

    2002-01-01

    A computer code PROVER-I is developed for propagation phase of vapor explosion. A new thermal fragmentation model is proposed with three kinds of time scale for modeling instant fragmentation, spontaneous nucleation fragmentation and normal boiling fragmentation. The energetics of ex-vessel vapor explosion is investigated based on different fragmentation models. A higher pressure peak and a larger mechanical energy conversion ratio are obtained by spontaneous nucleation fragmentation. A smaller energy conversion ratio results from normal boiling fragmentation. When the delay time in thermal fragmentation model is near 0.0 ms, the pressure propagation behavior tends to be analogous with that in hydrodynamic fragmentation. If the delay time is longer, pressure attenuation occurs at the shock front. The high energy conversion ratio (>4%) is obtained in a small vapor volume fraction together with spontaneous nucleation fragmentation. These results are consistent with fuel-coolant interaction experiments with alumina melt. However, in larger vapor volume fraction conditions (α υ >0.3), the vapor explosion is weak. For corium melt, a coarse mixture with void fraction of more than 30% can be generated in the pre-mixing process because of its physical properties. In the mixture with such a high void fraction the energetic vapor explosion hardly takes place. (author)

  13. Structural effect of ferrocenecarboxymethylated polymers on their electrical behavior under the exposure to methanol and acetone vapors

    International Nuclear Information System (INIS)

    Hachawee, Kosin; Lerdwijitjarud, Wanchai; Sittattrakul, Amnard; Sirivat, Anuvat

    2008-01-01

    Functionalized ferrocenecarboxymethylated polymers, i.e. poly(vinylbenzyl ferrocenecarboxymethylate) (PVBFCC), poly(vinylbenzyl ferrocenecarboxymethylate-co-ethoxyethylmethacrylate) with the mole ratio between vinylbenzyl ferrocenecarboxymethylate and ethoxyethylmethacrylate of 75:25 (Co-PVBFCC 75/25) and 50:50 (Co-PVBFCC 50/50), and ferrocenecarboxymethylated polysulfone (BPSFCC) were investigated for their electrical behavior under the vapors of methanol and acetone and nitrogen gas. Electrical conductivity responses of the four ferrocenecarboxymethylated polymers in the presence of lithium perchlorate were measured when they were exposed to nitrogen gas, and methanol and acetone vapors. Main factors that affect the electrical conductivity and sensitivity of these electroactive ferrocene polymers originate from the polymer structure and the type of the passing gas or vapor. Ferrocenecarboxymethylated polymers with higher degrees of substitution of ferrocene units possess good electrical conductivity under the atmosphere of mixed N 2 /methanol vapor, while ferrocenecarboxymethylated polymers with more flexible chain and/or larger free volumes give higher electrical conductivity under the atmosphere of mixed N 2 /acetone vapor. The gas or vapor molecule with higher polarity and smaller size enhances the electrical conductivity of the ferrocene polymers. Our results clearly indicate that the synthesized ferrocenecarboxymethylated polymers have potential to be used as methanol or acetone sensor materials

  14. Antioxidant activity and prevention of pork meat lipid oxidation using traditional Mexican condiments (pasilla dry pepper, achiote, and mole sauce

    Directory of Open Access Journals (Sweden)

    Emilio Alvarez-Parrilla

    2014-06-01

    Full Text Available Considering the extensive use of hot peppers and spicy sauces in the Mexican cuisine, in the present paper, three widely consumed Mexican condiments (mole sauce, achiote, and pasilla hot pepper were analyzed for their total phenols, flavonoids and proanthocyanidins, antioxidant activity, and protective effect against lipid oxidation in chopped pork meat. All samples were extracted first with methanol and then with acetone, and the extracts were compared. Pasilla pepper showed the highest phenolic and flavonoid content in both solvents, followed by mole and achiote. Achiote showed the highest proanthocyanidin concentration. All samples showed high antioxidant activity, and good correlations with phenolic compounds and flavonoids, while no correlation was observed in the case of condensed tannins. Mole sauce methanolic extract showed the highest inhibition of pork meat oxidation, followed by pasilla pepper, and finally achiote paste extracts. These results suggest that these condiments are useful to prevent meat lipid oxidation during storage.

  15. Diagnostic reproducibility of hydatidiform moles: ancillary techniques (p57 immunohistochemistry and molecular genotyping) improve morphologic diagnosis.

    Science.gov (United States)

    Vang, Russell; Gupta, Mamta; Wu, Lee-Shu-Fune; Yemelyanova, Anna V; Kurman, Robert J; Murphy, Kathleen M; Descipio, Cheryl; Ronnett, Brigitte M

    2012-03-01

    Distinction of hydatidiform moles (HMs) from nonmolar specimens (NMs) and subclassification of HMs as complete hydatidiform moles (CHMs) and partial hydatidiform moles (PHMs) are important for clinical practice and investigational studies; yet, diagnosis based solely on morphology is affected by interobserver variability. Molecular genotyping can distinguish these entities by discerning androgenetic diploidy, diandric triploidy, and biparental diploidy to diagnose CHMs, PHMs, and NMs, respectively. Eighty genotyped cases (27 CHMs, 27 PHMs, and 26 NMs) were selected from a series of 200 potentially molar specimens previously diagnosed using p57 immunostaining and genotyping. Cases were classified by 3 gynecologic pathologists on the basis of H&E slides (masked to p57 immunostaining and genotyping results) into 1 of 3 categories (CHM, PHM, or NM) during 2 diagnostic rounds; a third round incorporating p57 immunostaining results was also conducted. Consensus diagnoses (those rendered by 2 of 3 pathologists) were determined. Genotyping results were used as the gold standard for assessing diagnostic performance. Sensitivity of a diagnosis of CHM ranged from 59% to 100% for individual pathologists and from 70% to 81% by consensus; specificity ranged from 91% to 96% for individuals and from 94% to 98% by consensus. Sensitivity of a diagnosis of PHM ranged from 56% to 93% for individual pathologists and from 70% to 78% by consensus; specificity ranged from 58% to 92% for individuals and from 74% to 85% by consensus. The percentage of correct classification of all cases by morphology ranged from 55% to 75% for individual pathologists and from 70% to 75% by consensus. The κ values for interobserver agreement ranged from 0.59 to 0.73 (moderate to good) for a diagnosis of CHM, from 0.15 to 0.43 (poor to moderate) for PHM, and from 0.13 to 0.42 (poor to moderate) for NM. The κ values for intraobserver agreement ranged from 0.44 to 0.67 (moderate to good). Addition of the p57

  16. Beer Law Constants and Vapor Pressures of HgI2 over HgI2(s,l)

    Science.gov (United States)

    Su, Ching-Hua; Zhu, Shen; Ramachandran, N.; Burger, A.

    2002-01-01

    Optical absorption spectra of the vapor phase over HgI2(s,l) were measured at sample temperatures between 349 and 610 K for wavelengths between 200 and 600 nm. The spectra show the samples sublimed congruently into HGI2 without any observed Hg or I2 absorption spectra. The Beer's Law constants for 15 wavelengths between 200 and 440 nm were derived. From these constants the vapor pressure of HgI2, P, was found to be a function of temperature for the liquid and the solid beta-phases: ln P(atm) = -7700/T(K) + 12.462 (liquid phase) and ln P(atm) = -10150/T(K) + 17.026 (beta-phase). The expressions match the enthalpies of vaporization and sublimation of 15.30 and 20.17 kcal/mole respectively, for the liquid and the beta-phase HgI2. The difference in the enthalpies gives an enthalpy of fusion of 4.87 kcal/mole, and the intersection of the two expressions gives a melting point of 537 K.

  17. Passive vapor extraction feasibility study

    International Nuclear Information System (INIS)

    Rohay, V.J.

    1994-01-01

    Demonstration of a passive vapor extraction remediation system is planned for sites in the 200 West Area used in the past for the disposal of waste liquids containing carbon tetrachloride. The passive vapor extraction units will consist of a 4-in.-diameter pipe, a check valve, a canister filled with granular activated carbon, and a wind turbine. The check valve will prevent inflow of air that otherwise would dilute the soil gas and make its subsequent extraction less efficient. The granular activated carbon is used to adsorb the carbon tetrachloride from the air. The wind turbine enhances extraction rates on windy days. Passive vapor extraction units will be designed and operated to meet all applicable or relevant and appropriate requirements. Based on a cost analysis, passive vapor extraction was found to be a cost-effective method for remediation of soils containing lower concentrations of volatile contaminants. Passive vapor extraction used on wells that average 10-stdft 3 /min air flow rates was found to be more cost effective than active vapor extraction for concentrations below 500 parts per million by volume (ppm) of carbon tetrachloride. For wells that average 5-stdft 3 /min air flow rates, passive vapor extraction is more cost effective below 100 ppm

  18. The lithium vapor box divertor

    International Nuclear Information System (INIS)

    Goldston, R J; Schwartz, J; Myers, R

    2016-01-01

    It has long been recognized that volumetric dissipation of the plasma heat flux from a fusion power system is preferable to its localized impingement on a material surface. Volumetric dissipation mitigates both the anticipated very high heat flux and intense particle-induced damage due to sputtering. Recent projections to a tokamak demonstration power plant suggest an immense upstream parallel heat flux, of order 20 GW m −2 , implying that fully detached operation may be a requirement for the success of fusion power. Building on pioneering work on the use of lithium by Nagayama et al and by Ono et al as well as earlier work on the gas box divertor by Watkins and Rebut, we present here a concept for a lithium vapor box divertor, in which lithium vapor extracts momentum and energy from a fusion-power-plant divertor plasma, using fully volumetric processes. At the high powers and pressures that are projected this requires a high density of lithium vapor, which must be isolated from the main plasma in order to avoid lithium build-up on the chamber walls or in the plasma. Isolation is achieved through a powerful multi-box differential pumping scheme available only for condensable vapors. The preliminary box-wise calculations are encouraging, but much more work is required to demonstrate the practical viability of this scheme, taking into account at least 2D plasma and vapor flows within and between the vapor boxes and out of the vapor boxes to the main plasma. (paper)

  19. Gis-approach for variability assessment of soil electric conductivity under pedoturbation activity of mole rat (Spalax microphthalmus

    Directory of Open Access Journals (Sweden)

    T. М. Konovalova

    2010-06-01

    Full Text Available The results of the investigation of the impact of the mole rat’s activity on soil electric conductivity have been presented. GIS-technology have been shown to be effective for assessment of the pedoturbation activity effect on the soil surface heterogeneity formation. Method of the one-dimension spatial coordinated array transformation into matrix form has been proposed for following multidimension statistic analysis application. The quantity estimation of the mole rats role in formation of the habitat nanorelief-level diversity has been obtained by means of indexes of the landscape complexity and diversity.

  20. Prevalence and Factors Associated with Hydatidiform Mole among Patients Undergoing Uterine Evacuation at Mbarara Regional Referral Hospital

    Directory of Open Access Journals (Sweden)

    Olivier Mulisya

    2018-01-01

    Full Text Available Objective. We sought to determine the prevalence of and factors associated with hydatidiform molar gestations amongst patients undergoing uterine evacuation at Mbarara Regional Referral Hospital (MRRH, Mbarara, Uganda. Methods. This was a cross-sectional study carried out from November 2016 to February 2017. All patients admitted for uterine evacuation for nonviable pregnancy were included. The study registered 181 patients. Data were collected on sociodemographics, medical conditions, obstetrics, and gynecological factors. The evacuated tissue received a full gross and histopathologic examination. Cases of pathologically suspected complete hydatidiform mole were confirmed by p57 immunohistochemistry. Data were analyzed using STATA 13. Results. The prevalence of hydatidiform mole was 6.1% (11/181. All detected moles were complete hydatidiform moles, and there were no diagnosed partial hydatidiform moles. Clinical diagnosis of molar pregnancy was suspected in 13 patients, but only 69.2% (9/13 were confirmed as molar pregnancies histologically. Two cases were clinically unsuspected. Factors that had a significant relationship with complete hydatidiform mole included maternal age of 35 years and above (aOR 13.5; CI: 1.46–125.31; p=0.00, gestational age beyond the first trimester at the time of uterine evacuation (aOR 6.2; CI: 1.07–36.14; p=0.04, and history of previous abortion (aOR 4.3; CI: 1.00–18.57; p=0.05. Conclusion. The prevalence of complete hydatidiform mole was high at 6.1%. Associated risk factors included advanced maternal age (35 years and above, history of previous abortions, and gestational age beyond the first trimester at the time of evacuations. Recommendations. We recommend putting in place capacity to do routine histopathological examination of all products of conception especially those at high risk for a molar gestation either by clinical suspicion or by risk factors including advanced maternal age, advanced gestational

  1. Evidência molecular da ocorrência de um fitoplasma associado ao lenho mole da macieira

    OpenAIRE

    Ribeiro,Luiz Fernando Caldeira; Bedendo,Ivan Paulo; Sanhueza,Rosa Maria Valdebenito

    2007-01-01

    O lenho mole da macieira é uma doença relevante em diversas partes do mundo. Sintomas típicos desta doença têm sido observados em pomares instalados em estados do sul do território brasileiro desde a década de oitenta. Enxertia tem revelado a natureza infecciosa da doença e a observação de corpúsculos filamentosos no floema tem evidenciado possível associação com fitoplasma. No presente trabalho plantas com sintomas de lenho mole foram coletadas em pomar comercial, visando demonstrar a presen...

  2. Spatial variability of soil electrical conductivity under the mole rats (Spalax microphthalmus digging activity at the different scales

    Directory of Open Access Journals (Sweden)

    A. V. Zhukov

    2012-07-01

    Full Text Available The soil mounds emerged owing to the mole rats’ digging activity have been shown to be characterised by less electrical conductivity than surrounded soil. This effect is due to the changes of the mounds bulk’s density and moisture. The effect of the mole rats’ digging activity on the soil electrical conductivity has been found not to be restricted by the geometrical border of the mounds. The mounds are surrounded by 1–1.5 m halo of increased soil electrical conductivity. The halo size is increased with the aging of the mound and with the compacting of their aggregation.

  3. Fingerprinting: Modelling and mapping physical top soil properties with the Mole

    Science.gov (United States)

    Loonstra, Eddie; van Egmond, Fenny

    2010-05-01

    The Mole is a passive gamma ray soil sensor system. It is designed for the mobile collection of radioactive energy stemming from soil. As the system is passive, it only measures energy that reaches the surface of soil. In general, this energy comes from upto 30 to 40 cm deep, which can be considered topsoil. The gathered energy spectra are logged every second, are processed with the method of Full Spectrum Analysis. This method uses all available spectral data and processes it with a Chi square optimalisation using a set of standard spectra into individual nuclide point data. A standard spectrum is the measured full spectrum of a specific detector derived when exposed to 1 Bq/kg of a nuclide. With this method the outcome of the surveys become quantitative.The outcome of a field survey with the Mole results in a data file containing point information of position, Total Counts and the decay products of 232Th, 238U, 40K and 137Cs. Five elements are therefor available for the modelling of soil properties. There are several ways for the modelling of soil properties with sensor derived gamma ray data. The Mole generates ratio scale output. For modelling a quantitative deterministic approach is used based on sample locations. This process is called fingerprinting. Fingerprinting is a comparison of the concentration of the radioactive trace elements and the lab results (pH, clay content, etc.) by regression analysis. This results in a mathematical formula describing the relationship between a dependent and independent property. The results of the sensor readings are interpolated into a nuclide map with GIS software. With the derived formula a soil property map is composed. The principle of fingerprinting can be applied on large geographical areas for physical soil properties such as clay, loam or sand (50 micron), grain size and organic matter. Collected sample data of previous field surveys within the same region can be used for the prediction of soil properties elsewhere

  4. Slip casting of thoria-10 mole per cent yttria solid electrolyte

    International Nuclear Information System (INIS)

    Ramanathan, S.; Rao, S.V.K.

    1990-01-01

    One end closed thoria-yttria solid electrolyte have been fabricated by the slip casting technique. A systematic study of the influence of the process parameters on the characteristics of the final bodies has been carried out. Slips of ThO 2 -10 mole % Y 2 O 3 were prepared; their fluidity and castability were studied as a function of concentration, pH and particle size. The bodies were sintered at 2000degC and the physical properties like density and microstructure were evaluated. Slip cast bodies of bulk densities around 95% T.D. with relatively inhomogenous but predominantly fine grained structure could be obtained by optimizing the process variables. (author). 5 figs., 10 refs

  5. Comparative analysis of genome maintenance genes in naked mole rat, mouse, and human.

    Science.gov (United States)

    MacRae, Sheila L; Zhang, Quanwei; Lemetre, Christophe; Seim, Inge; Calder, Robert B; Hoeijmakers, Jan; Suh, Yousin; Gladyshev, Vadim N; Seluanov, Andrei; Gorbunova, Vera; Vijg, Jan; Zhang, Zhengdong D

    2015-04-01

    Genome maintenance (GM) is an essential defense system against aging and cancer, as both are characterized by increased genome instability. Here, we compared the copy number variation and mutation rate of 518 GM-associated genes in the naked mole rat (NMR), mouse, and human genomes. GM genes appeared to be strongly conserved, with copy number variation in only four genes. Interestingly, we found NMR to have a higher copy number of CEBPG, a regulator of DNA repair, and TINF2, a protector of telomere integrity. NMR, as well as human, was also found to have a lower rate of germline nucleotide substitution than the mouse. Together, the data suggest that the long-lived NMR, as well as human, has more robust GM than mouse and identifies new targets for the analysis of the exceptional longevity of the NMR. © 2015 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

  6. The effect of carbon mole ratio on the fabrication of silicon carbide

    Directory of Open Access Journals (Sweden)

    Sutham Niyomwas

    2008-03-01

    Full Text Available Silicon Carbide (SiC particles were synthesized by self-propagating high temperature synthesis (SHS from a powder mixture of SiO2-C-Mg. The reaction was carried out in a SHS reactor under static argon gas at a pressure of 0.5 MPa. The standard Gibbs energy minimization method was used to calculate the equilibrium composition of the reacting species. The effects of carbon mole ratio on the precursor mixture (C/SiO2/Mg: 1/1/2 to 3/1/2 and on the SiC conversion were investigated using X-ray diffraction and scanning electron microscope technique. The as-synthesized products of SiC-MgO powders were leached with 0.1M HCl acid solution to obtain the SiC particles.

  7. Dimers in nucleating vapors

    Science.gov (United States)

    Lushnikov, A. A.; Kulmala, M.

    1998-09-01

    The dimer stage of nucleation may affect considerably the rate of the nucleation process at high supersaturation of the nucleating vapor. Assuming that the dimer formation limits the nucleation rate, the kinetics of the particle formation-growth process is studied starting with the definition of dimers as bound states of two associating molecules. The partition function of dimer states is calculated by summing the Boltzmann factor over all classical bound states, and the equilibrium population of dimers is found for two types of intermolecular forces: the Lennard-Jones (LJ) and rectangular well+hard core (RW) potentials. The principle of detailed balance is used for calculating the evaporation rate of dimers. The kinetics of the particle formation-growth process is then investigated under the assumption that the trimers are stable with respect to evaporation and that the condensation rate is a power function of the particle mass. If the power exponent λ=n/(n+1) (n is a non-negative integer), the kinetics of the process is described by a finite set of moments of particle mass distribution. When the characteristic time of the particle formation by nucleation is much shorter than that of the condensational growth, n+2 universal functions of a nondimensional time define the kinetic process. These functions are calculated for λ=2/3 (gas-to-particle conversion in the free molecular regime) and λ=1/2 (formation of islands on surfaces).

  8. Ethnotaxonomical Study of Mole Crab (Crustacea:Hippoidea on Coastal Community of Cilacap

    Directory of Open Access Journals (Sweden)

    Dian Bhagawati

    2016-09-01

    Full Text Available Local wisdom is a cultural heritage that needs to be preserved. The Cilacap’s coastal communities have traditional taxonomy knowledge that hasn’t been informed, especially about mole crab. This study aimed to explore the ethnotaxonomy knowledge of sand crabs (Crustacea: Hippoidea in Widarapayung coastal communities. The purposive snowball sampling was used for the method, followed by observation and semi-structured interviews with 30 respondents. Data were analyzed descriptively based on observations and interviews. The results showed that the coastal communities in Widarapayung tourist areas could be divided into five groups, namely catchers, collectors, processors, traders, and consumers. The catcher was able to recognize and describe three types of sand crabs based on the shape of the body and their catchment areas. Captured crabs had the local name of ‘yutuk jambe’ (Emerita emeritus Linnaeus 1767, the appellation was based on carapace shape that resembled the shape of areca fruit; ‘Yutuk bathok’ (Hippa adactyla Fabricius 1787, had the carapace shape resembling a coconut shell, and ‘yutuk Kethek’ (Albunea symmysta Linnaeus 1758, had ornaments on the carapace surface similar with a monkey face, there were dense setae on the edge of the carapace, spiny long antennas and aggressively pinch when captured. The knowledge and skills of sand crabs classification and local name entitlement acquired by the people were in accordance with the Berlin’s model. How to CiteBhagawati, D., Anggoro, S., Zainuri, M. & Sya’rani, L. (2016. Ethnotaxonomical Study of Mole Crab (Crustacea:Hippoidea on Coastal Community of Cilacap. Biosaintifika: Journal of Biology & Biology Education, 8(2, 222-230.

  9. Molecular basis of a novel adaptation to hypoxic-hypercapnia in a strictly fossorial mole

    Directory of Open Access Journals (Sweden)

    Bonaventura Joseph

    2010-07-01

    Full Text Available Abstract Background Elevated blood O2 affinity enhances survival at low O2 pressures, and is perhaps the best known and most broadly accepted evolutionary adjustment of terrestrial vertebrates to environmental hypoxia. This phenotype arises by increasing the intrinsic O2 affinity of the hemoglobin (Hb molecule, by decreasing the intracellular concentration of allosteric effectors (e.g., 2,3-diphosphoglycerate; DPG, or by suppressing the sensitivity of Hb to these physiological cofactors. Results Here we report that strictly fossorial eastern moles (Scalopus aquaticus have evolved a low O2 affinity, DPG-insensitive Hb - contrary to expectations for a mammalian species that is adapted to the chronic hypoxia and hypercapnia of subterranean burrow systems. Molecular modelling indicates that this functional shift is principally attributable to a single charge altering amino acid substitution in the β-type δ-globin chain (δ136Gly→Glu of this species that perturbs electrostatic interactions between the dimer subunits via formation of an intra-chain salt-bridge with δ82Lys. However, this replacement also abolishes key binding sites for the red blood cell effectors Cl-, lactate and DPG (the latter of which is virtually absent from the red cells of this species at δ82Lys, thereby markedly reducing competition for carbamate formation (CO2 binding at the δ-chain N-termini. Conclusions We propose this Hb phenotype illustrates a novel mechanism for adaptively elevating the CO2 carrying capacity of eastern mole blood during burst tunnelling activities associated with subterranean habitation.

  10. Adaptation of pelage color and pigment variations in Israeli subterranean blind mole rats, Spalax ehrenbergi [corrected].

    Directory of Open Access Journals (Sweden)

    Natarajan Singaravelan

    Full Text Available Concealing coloration in rodents is well established. However, only a few studies examined how soil color, pelage color, hair-melanin content, and genetics (i.e., the causal chain synergize to configure it. This study investigates the causal chain of dorsal coloration in Israeli subterranean blind mole rats, Spalax ehrenbergi.We examined pelage coloration of 128 adult animals from 11 populations belonging to four species of Spalax ehrenbergi superspecies (Spalax galili, Spalax golani, Spalax carmeli, and Spalax judaei and the corresponding coloration of soil samples from the collection sites using a digital colorimeter. Additionally, we quantified hair-melanin contents of 67 animals using HPLC and sequenced the MC1R gene in 68 individuals from all four mole rat species.Due to high variability of soil colors, the correlation between soil and pelage color coordinates was weak and significant only between soil hue and pelage lightness. Multiple stepwise forward regression revealed that soil lightness was significantly associated with all pelage color variables. Pelage color lightness among the four species increased with the higher southward aridity in accordance to Gloger's rule (darker in humid habitats and lighter in arid habitats. Darker and lighter pelage colors are associated with darker basalt and terra rossa, and lighter rendzina soils, respectively. Despite soil lightness varying significantly, pelage lightness and eumelanin converged among populations living in similar soil types. Partial sequencing of the MC1R gene identified three allelic variants, two of which were predominant in northern species (S. galili and S. golani, and the third was exclusive to southern species (S. carmeli and S. judaei, which might have caused the differences found in pheomelanin/eumelanin ratio.Darker dorsal pelage in darker basalt and terra rossa soils in the north and lighter pelage in rendzina and loess soils in the south reflect the combined results of

  11. Ear Structures of the Naked Mole-Rat, Heterocephalus glaber, and Its Relatives (Rodentia: Bathyergidae.

    Directory of Open Access Journals (Sweden)

    Matthew J Mason

    Full Text Available Although increasingly popular as a laboratory species, very little is known about the peripheral auditory system of the naked mole-rat, Heterocephalus glaber. In this study, middle and inner ears of naked mole-rats of a range of ages were examined using micro-computed tomography and dissection. The ears of five other bathyergid species (Bathyergus suillus, Cryptomys hottentotus, Fukomys micklemi, Georychus capensis and Heliophobius argenteocinereus were examined for comparative purposes. The middle ears of bathyergids show features commonly found in other members of the Ctenohystrica rodent clade, including a fused malleus and incus, a synovial stapedio-vestibular articulation and the loss of the stapedius muscle. Heterocephalus deviates morphologically from the other bathyergids examined in that it has a more complex mastoid cavity structure, poorly-ossified processes of the malleus and incus, a 'columelliform' stapes and fewer cochlear turns. Bathyergids have semicircular canals with unusually wide diameters relative to their radii of curvature. How the lateral semicircular canal reaches the vestibule differs between species. Heterocephalus has much more limited high-frequency hearing than would be predicted from its small ear structures. The spongy bone forming its ossicular processes, the weak incudo-stapedial articulation, the columelliform stapes and (compared to other bathyergids reduced cochlear coiling are all potentially degenerate features which might reflect a lack of selective pressure on its peripheral auditory system. Substantial intraspecific differences were found in certain middle and inner ear structures, which might also result from relaxed selective pressures. However, such interpretations must be treated with caution in the absence of experimental evidence.

  12. Social condition and oxytocin neuron number in the hypothalamus of naked mole-rats (Heterocephalus glaber).

    Science.gov (United States)

    Mooney, S J; Holmes, M M

    2013-01-29

    The naked mole-rat is a subterranean colonial rodent. In each colony, which can grow to as many as 300 individuals, there is only one female and 1-3 males that are reproductive and socially dominant. The remaining animals are reproductively suppressed subordinates that contribute to colony survival through their cooperative behaviors. Oxytocin is a peptide hormone that has shown relatively widespread effects on prosocial behaviors in other species. We examined whether social status affects the number of oxytocin-immunoreactive neurons in the paraventricular nucleus and the supraoptic nucleus by comparing dominant breeding animals to subordinate non-breeding workers from intact colonies. We also examined these regions in subordinate animals that had been removed from their colony and paired with an opposite- or same-sex conspecific for 6 months. Stereological analyses indicated that subordinates had significantly more oxytocin neurons in the paraventricular nucleus than breeders. Animals in both opposite- and same-sex pairs showed a decreased oxytocin neuron number compared to subordinates suggesting that status differences may be due to social condition rather than the reproductive activity of the animal per se. The effects of social status appear to be region specific as no group differences were found for oxytocin neuron number in the supraoptic nucleus. Given that subordinate naked mole-rats are kept reproductively suppressed through antagonism by the queen, we speculate that status differences are due either to oxytocin's anxiolytic properties to combat the stress of this antagonism or to its ability to promote the prosocial behaviors of subordinates. Copyright © 2012 IBRO. Published by Elsevier Ltd. All rights reserved.

  13. Ear Structures of the Naked Mole-Rat, Heterocephalus glaber, and Its Relatives (Rodentia: Bathyergidae).

    Science.gov (United States)

    Mason, Matthew J; Cornwall, Hannah L; Smith, Ewan St J

    2016-01-01

    Although increasingly popular as a laboratory species, very little is known about the peripheral auditory system of the naked mole-rat, Heterocephalus glaber. In this study, middle and inner ears of naked mole-rats of a range of ages were examined using micro-computed tomography and dissection. The ears of five other bathyergid species (Bathyergus suillus, Cryptomys hottentotus, Fukomys micklemi, Georychus capensis and Heliophobius argenteocinereus) were examined for comparative purposes. The middle ears of bathyergids show features commonly found in other members of the Ctenohystrica rodent clade, including a fused malleus and incus, a synovial stapedio-vestibular articulation and the loss of the stapedius muscle. Heterocephalus deviates morphologically from the other bathyergids examined in that it has a more complex mastoid cavity structure, poorly-ossified processes of the malleus and incus, a 'columelliform' stapes and fewer cochlear turns. Bathyergids have semicircular canals with unusually wide diameters relative to their radii of curvature. How the lateral semicircular canal reaches the vestibule differs between species. Heterocephalus has much more limited high-frequency hearing than would be predicted from its small ear structures. The spongy bone forming its ossicular processes, the weak incudo-stapedial articulation, the columelliform stapes and (compared to other bathyergids) reduced cochlear coiling are all potentially degenerate features which might reflect a lack of selective pressure on its peripheral auditory system. Substantial intraspecific differences were found in certain middle and inner ear structures, which might also result from relaxed selective pressures. However, such interpretations must be treated with caution in the absence of experimental evidence.

  14. Peripheral administration of oxytocin increases social affiliation in the naked mole-rat (Heterocephalus glaber).

    Science.gov (United States)

    Mooney, Skyler J; Douglas, Natasha R; Holmes, Melissa M

    2014-04-01

    The neuropeptide oxytocin regulates a wide variety of social behaviors across diverse species. However, the types of behaviors that are influenced by this hormone are constrained by the species in question and the social organization that a particular species exhibits. Therefore, the present experiments investigated behaviors regulated by oxytocin in a eusocial mammalian species by using the naked mole-rat (Heterocephalus glaber). In Experiment 1, adult non-breeding mole-rats were given intraperitoneal injections of either oxytocin (1mg/kg or 10mg/kg) or saline on alternate days. Animals were then returned to their colony and behavior was recorded for minutes 15-30 post-injection. Both doses of oxytocin increased huddling behavior during this time period. In Experiment 2, animals received intraperitoneal injections of either oxytocin (1mg/kg), an oxytocin-receptor antagonist (0.1mg/kg), a cocktail of oxytocin and the antagonist, or saline across 4 testing days in a counterbalanced design. Animals were placed in either a 2-chamber arena with a familiar conspecific or in a small chamber with 1week old pups from their home colony and behaviors were recorded for minutes 15-30 post-injection. Oxytocin increased investigation of, and time spent in close proximity to, a familiar conspecific; these effects were blocked by the oxytocin antagonist. No effects were seen on pup-directed behavior. These data suggest that oxytocin is capable of modulating affiliative-like behavior in this eusocial species. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. Effect of Temperature and Mole Ratio on the Synthesis Yield of Rhenium-Tetrofosmin

    Directory of Open Access Journals (Sweden)

    Widyastuti

    2015-08-01

    Full Text Available Technetium-99m (99mTc tetrofosmin is widely used in nuclear medicine as a diagnostic agent for myocardial perfusion and as a tumor imaging agent. As a parenteral preparation it requires an evaluation of its pharmacokinetics and stability in-vivo. Since 99mTc has a short half-life and is only available in very low concentrations, it is impossible to characterize its chemical properties and presence in the body. Due to this reason, only technetium-99 (T1/2 = 5 × 105 years, which is available in macro quantities, or natural rhenium can be used for this purpose. In this study rhenium-188 (188Re tetrofosmin will be synthesized and applied, because non-radioactive Re can be easily obtained. Synthesis and radiochemical purity analysis of carrier-added 188Re-tetrofosmin were carried out as a model to study the in-vivo stability of technetium-99m tetrofosmin. Rhenium-188 was used as a tracer to identify the formation of rhenium tetrofosmin. Rhenium gluconate was synthesized first prior to the formation of rhenium tetrofosmin. The quality of labeling for both rhenium gluconate and rhenium tetrofosmin was analyzed using paper- and thin-layer chromatography, respectively. Rhenium gluconate can be synthesized with high labeling yield within 1 hour, whereas rhenium tetrofosmin was synthesized both in room temperature and in an elevated temperature with various tetrofosmin-to-rhenium mole ratios.The results showed that heating at 95oC led to a higher yield of more than 90% within 30 minutes. Rhenium tetrofosmin could be produced in high radiochemical purity using an excess of tetrofosmin with mole ratio of 2000. It is concluded that rhenium tetrofosmin could be synthesized through the formation of rhenium gluconate, and a higher yield could be obtained in a shorter time by heating process.

  16. Fractional quantum mechanics

    CERN Document Server

    Laskin, Nick

    2018-01-01

    Fractional quantum mechanics is a recently emerged and rapidly developing field of quantum physics. This is the first monograph on fundamentals and physical applications of fractional quantum mechanics, written by its founder. The fractional Schrödinger equation and the fractional path integral are new fundamental physical concepts introduced and elaborated in the book. The fractional Schrödinger equation is a manifestation of fractional quantum mechanics. The fractional path integral is a new mathematical tool based on integration over Lévy flights. The fractional path integral method enhances the well-known Feynman path integral framework. Related topics covered in the text include time fractional quantum mechanics, fractional statistical mechanics, fractional classical mechanics and the α-stable Lévy random process. The book is well-suited for theorists, pure and applied mathematicians, solid-state physicists, chemists, and others working with the Schrödinger equation, the path integral technique...

  17. Tubing For Sampling Hydrazine Vapor

    Science.gov (United States)

    Travis, Josh; Taffe, Patricia S.; Rose-Pehrsson, Susan L.; Wyatt, Jeffrey R.

    1993-01-01

    Report evaluates flexible tubing used for transporting such hypergolic vapors as those of hydrazines for quantitative analysis. Describes experiments in which variety of tubing materials, chosen for their known compatibility with hydrazine, flexibility, and resistance to heat.

  18. Vapor trap for liquid metal

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, T

    1968-05-22

    In a pipe system which transfers liquid metal, inert gas (cover gas) is packed above the surface of the liquid metal to prevent oxidization of the liquid. If the metal vapor is contained in such cover gas, the circulating system of the cover gas is blocked due to condensation of liquid metal inside the system. The present invention relates to an improvement in vapor trap to remove the metal vapor from the cover gas. The trap consists of a cylindrical outer body, an inlet nozzle which is deeply inserted inside the outer body and has a number of holes to inject the cove gas into the body, metal mesh or steel wool which covers the exterior of the nozzle and on which the condensation of the metal gas takes place, and a heater wire hich is wound around the nozzle to prevent condensation of the metal vapor at the inner peripheral side of the mesh.

  19. Fractional vector calculus and fractional Maxwell's equations

    International Nuclear Information System (INIS)

    Tarasov, Vasily E.

    2008-01-01

    The theory of derivatives and integrals of non-integer order goes back to Leibniz, Liouville, Grunwald, Letnikov and Riemann. The history of fractional vector calculus (FVC) has only 10 years. The main approaches to formulate a FVC, which are used in the physics during the past few years, will be briefly described in this paper. We solve some problems of consistent formulations of FVC by using a fractional generalization of the Fundamental Theorem of Calculus. We define the differential and integral vector operations. The fractional Green's, Stokes' and Gauss's theorems are formulated. The proofs of these theorems are realized for simplest regions. A fractional generalization of exterior differential calculus of differential forms is discussed. Fractional nonlocal Maxwell's equations and the corresponding fractional wave equations are considered

  20. Fractional statistics and fractional quantized Hall effect

    International Nuclear Information System (INIS)

    Tao, R.; Wu, Y.S.

    1985-01-01

    The authors suggest that the origin of the odd-denominator rule observed in the fractional quantized Hall effect (FQHE) may lie in fractional statistics which govern quasiparticles in FQHE. A theorem concerning statistics of clusters of quasiparticles implies that fractional statistics do not allow coexistence of a large number of quasiparticles at fillings with an even denominator. Thus, no Hall plateau can be formed at these fillings, regardless of the presence of an energy gap. 15 references

  1. Vaporization order and burning efficiency of crude oils during in-situ burning on water

    DEFF Research Database (Denmark)

    van Gelderen, Laurens; Malmquist, Linus M.V.; Jomaas, Grunde

    2017-01-01

    furthermore showed that the vaporization was diffusion-limited. Analysis of the heat transfer balance for the crude oils indicated that the energy available for evaporation decreased over time due to increasing heat losses, which were caused by the volatility controlled vaporization order. Presumably, larger......In order to improve the understanding of the burning efficiency and its observed size dependency of in-situ burning of crude oil on water, the vaporization order of the components in crude oils was studied. The vaporization order of such multicomponent fuels was assessed by studying the surface...... these results. The crude oils did not show any steady state behavior, but instead had an increasing surface temperature and decreasing burning rate and flame height, indicating a volatility controlled vaporization order. An increasing concentration gradient from the medium to heavy fraction in the burn residues...

  2. Initialized Fractional Calculus

    Science.gov (United States)

    Lorenzo, Carl F.; Hartley, Tom T.

    2000-01-01

    This paper demonstrates the need for a nonconstant initialization for the fractional calculus and establishes a basic definition set for the initialized fractional differintegral. This definition set allows the formalization of an initialized fractional calculus. Two basis calculi are considered; the Riemann-Liouville and the Grunwald fractional calculi. Two forms of initialization, terminal and side are developed.

  3. Undifferentiated carcinoma with osteoclastic giant cells (UCOCGC) of the pancreas associated with the familial atypical multiple mole melanoma syndrome (FAMMM)

    NARCIS (Netherlands)

    Koorstra, Jan-Bart M.; Maitra, Anirban; Morsink, Folkert H. M.; Drillenburg, Paul; ten Kate, Fiebo J. W.; Hruban, Ralph H.; Offerhaus, Johan A.

    2008-01-01

    The familial atypical multiple mole melanoma (FAMMM) syndrome is caused by a germline mutation of p16. More than 90% of the sporadic pancreatic carcinomas contain genetic alterations that inactivate p16. Patients with the FAMMM syndrome have an increased risk of developing pancreatic cancer. Ductal

  4. Development of Two-Tier Diagnostic Test Pictorial-Based for Identifying High School Students Misconceptions on the Mole Concept

    Science.gov (United States)

    Siswaningsih, W.; Firman, H.; Zackiyah; Khoirunnisa, A.

    2017-02-01

    The aim of this study was to develop the two-tier pictorial-based diagnostic test for identifying student misconceptions on mole concept. The method of this study is used development and validation. The development of the test Obtained through four phases, development of any items, validation, determination key, and application test. Test was developed in the form of pictorial consisting of two tier, the first tier Consist of four possible answers and the second tier Consist of four possible reasons. Based on the results of content validity of 20 items using the CVR (Content Validity Ratio), a number of 18 items declared valid. Based on the results of the reliability test using SPSS, Obtained 17 items with Cronbach’s Alpha value of 0703, the which means that items have accepted. A total of 10 items was conducted to 35 students of senior high school students who have studied the mole concept on one of the high schools in Cimahi. Based on the results of the application test, student misconceptions were identified in each label concept in mole concept with the percentage of misconceptions on the label concept of mole (60.15%), Avogadro’s number (34.28%), relative atomic mass (62, 84%), relative molecule mass (77.08%), molar mass (68.53%), molar volume of gas (57.11%), molarity (71.32%), chemical equation (82.77%), limiting reactants (91.40%), and molecular formula (77.13%).

  5. Vocalisations of the silvery mole-rat: comparasion of vocal repertoires in subterrane an rodents with different socials systems

    Czech Academy of Sciences Publication Activity Database

    Knotková, E.; Veitl, S.; Šumbera, R.; Sedláček, František; Burda, H.

    2009-01-01

    Roč. 18, č. 3 (2009), s. 241-257 ISSN 0952-4622 Institutional research plan: CEZ:AV0Z60870520 Keywords : silvery mole-rat * bathyergidae * vocal communication Subject RIV: EG - Zoology Impact factor: 1.050, year: 2009

  6. Functional neurokinin and NMDA receptor activity in an animal naturally lacking substance P: the naked mole-rat.

    Directory of Open Access Journals (Sweden)

    Antje Brand

    Full Text Available Naked mole-rats are extremely unusual among mammals in that their cutaneous C-fibers lack the neuropeptide Substance P (SP. In other mammals, SP plays an important role in nociception: it is released from C-fibers onto spinal neurons where it facilitates NMDA receptor activity and causes sensitization that can last for minutes, hours or days. In the present study, we tested the effects of intrathecal application of: 1 SP, 2 an SP antagonist (GR-82334, and 3 an NMDA antagonist (APV on heat-evoked foot withdrawal. In the naked mole-rat, at a high enough concentration, application of SP caused a large, immediate, and long-lasting sensitization of foot withdrawal latency that was transiently reversed by application of either antagonist. However, neither SP nor NMDA antagonists had an effect when administered alone to naïve animals. In contrast, both antagonists induced an increase in basal withdrawal latency in mice. These results indicate that spinal neurons in naked mole-rats have functional SP and NMDA receptors, but that these receptors do not participate in heat-evoked foot withdrawal unless SP is experimentally introduced. We propose that the natural lack of SP in naked mole-rat C-fibers may have resulted during adaptation to living in a chronically high carbon dioxide, high ammonia environment that, in other mammals, would stimulate C-fibers and evoke nocifensive behavior.

  7. Four Cases of Spontaneous Neoplasia in the Naked Mole-Rat (Heterocephalus glaber), A Putative Cancer-Resistant Species.

    Science.gov (United States)

    Taylor, Kyle R; Milone, Nicholas A; Rodriguez, Carlos E

    2017-01-01

    The naked mole-rat (Heterocephalus glaber) is widely acclaimed to be cancer-resistant and of considerable research interest based on a paucity of reports of neoplasia in this species. We have, however, encountered four spontaneous cases of neoplasia and one presumptive case of neoplasia through routine necropsy and biopsy of individuals in a zoo collection of nonhybrid naked mole-rats bred from a single pair. One case each of metastasizing hepatocellular carcinoma, nephroblastoma (Wilms' tumor), and multicentric lymphosarcoma, as well as presumptive esophageal adenocarcinoma (Barrett's esophagus-like) was identified postmortem among 37 nonautolyzed necropsy submissions of naked mole-rats over 1-year-old that were submitted for necropsy between 1998 and August 2015. One incidental case of cutaneous hemangioma was also identified antemortem by skin biopsy from one naked mole-rat examined for trauma. © The Author 2016. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  8. Functional neurokinin and NMDA receptor activity in an animal naturally lacking substance P: the naked mole-rat.

    Science.gov (United States)

    Brand, Antje; Smith, Ewan St J; Lewin, Gary R; Park, Thomas J

    2010-12-21

    Naked mole-rats are extremely unusual among mammals in that their cutaneous C-fibers lack the neuropeptide Substance P (SP). In other mammals, SP plays an important role in nociception: it is released from C-fibers onto spinal neurons where it facilitates NMDA receptor activity and causes sensitization that can last for minutes, hours or days. In the present study, we tested the effects of intrathecal application of: 1) SP, 2) an SP antagonist (GR-82334), and 3) an NMDA antagonist (APV) on heat-evoked foot withdrawal. In the naked mole-rat, at a high enough concentration, application of SP caused a large, immediate, and long-lasting sensitization of foot withdrawal latency that was transiently reversed by application of either antagonist. However, neither SP nor NMDA antagonists had an effect when administered alone to naïve animals. In contrast, both antagonists induced an increase in basal withdrawal latency in mice. These results indicate that spinal neurons in naked mole-rats have functional SP and NMDA receptors, but that these receptors do not participate in heat-evoked foot withdrawal unless SP is experimentally introduced. We propose that the natural lack of SP in naked mole-rat C-fibers may have resulted during adaptation to living in a chronically high carbon dioxide, high ammonia environment that, in other mammals, would stimulate C-fibers and evoke nocifensive behavior.

  9. Dynamic Thermodynamics with Internal Energy, Volume, and Amount of Moles as States : Application to Liquefied Gas Tank

    NARCIS (Netherlands)

    Arendsen, A. R. J.; Versteeg, G. F.

    2009-01-01

    Dynamic models for process design, optimization, and control usually solve a set of heat and/or mass balances as a function of time and/or position in the process. To obtain more robust dynamic models and to minimize the amount of assumptions, internal energy, volume, and amount of moles are chosen

  10. A vaporization study of the Ru–Te binary system by Knudsen effusion mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Lakshmi Narasimhan, T.S., E-mail: tslak@igcar.gov.in; Balasubramanian, R., E-mail: rbs@igcar.gov.in; Manikandan, P., E-mail: manikandan@igcar.gov.in; Viswanathan, R., E-mail: rvis@igcar.gov.in

    2013-12-25

    Highlights: •Knudsen effusion mass spectrometric study of the Ru–Te binary system conducted for the first time. •Direct confirmation of incongruent vaporization of RuTe{sub 2} – primarily to Te{sub 2}(g) and to a very small extent to Te(g). •p–T relations for Te{sub 2} and Te (860–1030 K), the relative compositions consistent with those on other M–Te systems. •Thermodynamic data for the reaction: RuTe{sub 2}(s) = Ru(s) + 2/i Te{sub i}(g) (i = 2 and 1) and for the formation of RuTe{sub 2}(s). •The Ru-rich phase boundary of RuTe{sub 2}(s) close to the stoichiometric value and the Te-rich phase boundary uncertain. -- Abstract: Vaporization studies on some Ru–Te samples with initial compositions 40.0 and 50.5 at.% Te, corresponding to the two-phase field (Ru + RuTe{sub 2}) and of initial compositions 69.5 and 71.5 at.% Te, corresponding to the two-phase field (RuTe{sub 2} + Te) were conducted by Knudsen effusion mass spectrometry. The vaporization was found to be one of incongruent in nature with the vapor phase consisting only of the component tellurium. The partial pressures of Te{sub 2}(g) and Te(g) were measured over (Ru + RuTe{sub 2}) in the temperature range of (860–1030) K and the p–T relations were deduced as: Log [p(Te{sub 2})/Pa] = [−(14,335 ± 148)/(T/K)] + (14.416 ± 0.154) and Log [p(Te)/Pa] = [−(13,838 ± 218)/(T/K)] + (12.480 ± 0.226). The relative mole fraction of Te(g) was < 0.05. From the partial pressures, the thermodynamic data for the vaporization reactions RuTe{sub 2}(s) = Ru(s) + 2/i Te{sub i}(g) where i = 2 and 1 were deduced and so also were for the formation of RuTe{sub 2}(s): Δ{sub r}H{sub m}{sup o}(298.15K)/(kJmol{sup -1})=284.3±16.4(i=2)and537.7±24.7(i=1); Δ{sub r}S{sub m}{sup o}(298.15K)/(Jmol{sup -1}K{sup -1})=200.2±10.4(i=2)and155.0±4.3(i=1); Δ{sub f}H{sub m}{sup o}(RuTe{sub 2},s,298.15K)/(kJmol{sup -1})=-(121.1±16.4); Δ{sub f}S{sub m}{sup o}(RuTe{sub 2},s,298.15K)/(Jmol{sup -1}K{sup -1})=-(39.8

  11. Tempered fractional calculus

    Energy Technology Data Exchange (ETDEWEB)

    Sabzikar, Farzad, E-mail: sabzika2@stt.msu.edu [Department of Statistics and Probability, Michigan State University, East Lansing, MI 48823 (United States); Meerschaert, Mark M., E-mail: mcubed@stt.msu.edu [Department of Statistics and Probability, Michigan State University, East Lansing, MI 48823 (United States); Chen, Jinghua, E-mail: cjhdzdz@163.com [School of Sciences, Jimei University, Xiamen, Fujian, 361021 (China)

    2015-07-15

    Fractional derivatives and integrals are convolutions with a power law. Multiplying by an exponential factor leads to tempered fractional derivatives and integrals. Tempered fractional diffusion equations, where the usual second derivative in space is replaced by a tempered fractional derivative, govern the limits of random walk models with an exponentially tempered power law jump distribution. The limiting tempered stable probability densities exhibit semi-heavy tails, which are commonly observed in finance. Tempered power law waiting times lead to tempered fractional time derivatives, which have proven useful in geophysics. The tempered fractional derivative or integral of a Brownian motion, called a tempered fractional Brownian motion, can exhibit semi-long range dependence. The increments of this process, called tempered fractional Gaussian noise, provide a useful new stochastic model for wind speed data. A tempered fractional difference forms the basis for numerical methods to solve tempered fractional diffusion equations, and it also provides a useful new correlation model in time series.

  12. Tempered fractional calculus

    Science.gov (United States)

    Sabzikar, Farzad; Meerschaert, Mark M.; Chen, Jinghua

    2015-07-01

    Fractional derivatives and integrals are convolutions with a power law. Multiplying by an exponential factor leads to tempered fractional derivatives and integrals. Tempered fractional diffusion equations, where the usual second derivative in space is replaced by a tempered fractional derivative, govern the limits of random walk models with an exponentially tempered power law jump distribution. The limiting tempered stable probability densities exhibit semi-heavy tails, which are commonly observed in finance. Tempered power law waiting times lead to tempered fractional time derivatives, which have proven useful in geophysics. The tempered fractional derivative or integral of a Brownian motion, called a tempered fractional Brownian motion, can exhibit semi-long range dependence. The increments of this process, called tempered fractional Gaussian noise, provide a useful new stochastic model for wind speed data. A tempered fractional difference forms the basis for numerical methods to solve tempered fractional diffusion equations, and it also provides a useful new correlation model in time series.

  13. Tempered fractional calculus

    International Nuclear Information System (INIS)

    Sabzikar, Farzad; Meerschaert, Mark M.; Chen, Jinghua

    2015-01-01

    Fractional derivatives and integrals are convolutions with a power law. Multiplying by an exponential factor leads to tempered fractional derivatives and integrals. Tempered fractional diffusion equations, where the usual second derivative in space is replaced by a tempered fractional derivative, govern the limits of random walk models with an exponentially tempered power law jump distribution. The limiting tempered stable probability densities exhibit semi-heavy tails, which are commonly observed in finance. Tempered power law waiting times lead to tempered fractional time derivatives, which have proven useful in geophysics. The tempered fractional derivative or integral of a Brownian motion, called a tempered fractional Brownian motion, can exhibit semi-long range dependence. The increments of this process, called tempered fractional Gaussian noise, provide a useful new stochastic model for wind speed data. A tempered fractional difference forms the basis for numerical methods to solve tempered fractional diffusion equations, and it also provides a useful new correlation model in time series

  14. Photic induction of Fos in the suprachiasmatic nucleus of African mole-rats: responses to increasing irradiance.

    Science.gov (United States)

    Oosthuizen, Maria K; Bennett, Nigel C; Cooper, Howard M

    2010-09-01

    African mole-rats (family Bathyergidae) are strictly subterranean rodent species that are rarely exposed to environmental light. Morphological and physiological adaptations to the underground environment include a severely reduced eye size and regressed visual system. Responses of the circadian system to light, however, appear to be intact, since mole-rats are able to entrain their circadian activity rhythms to the light-dark cycle and light induces Fos expression in the suprachiasmatic nucleus (SCN). Social organization varies from solitary species to highly elaborated eusocial structures, characterized by a distinct division of labor and in which one reproductive female regulates the behavior and reproductive physiology of other individuals in the colony. The authors studied light-induced Fos expression in the SCN to increasing light intensities in four mole-rat species, ranging from strictly solitary to highly social. In the solitary Cape mole-rat, light induces significant Fos expression in the SCN, and the number of Fos-immunopositive cells increases with increasing light intensity. In contrast, Fos induction in the SCN of social species was slightly greater than, but not statistically different from, the dark-control animals as is typical of most rodents. One species showed a trend for an increase in expression with increased light, whereas a second species showed no trend in expression. In the naked mole-rat, Fos expression appeared higher in the dark-controls than in the animals exposed to light, although the differences in Fos expression were not significant. These results suggest a gradient in the sensitivity of the circadian system to light in mole-rats, with a higher percentage of individuals that are unresponsive to light in correlation with the degree of sociality. In highly social species, such as the naked mole-rat that live in a relatively stable subterranean milieu in terms of food availability, temperature, constant darkness, and devoid of 24-h

  15. The effects of oxotremorine, epibatidine, atropine, mecamylamine and naloxone in the tail-flick, hot-plate, and formalin tests in the naked mole-rat (Heterocephalus glaber)

    DEFF Research Database (Denmark)

    Dulu, Thomas D; Kanui, Titus I; Towett, Philemon K

    2014-01-01

    The naked mole-rat (Heterocephalus glaber) is a promising animal model for the study of pain mechanisms, therefore a thorough characterization of this species is essential. The aim of the present study was to establish the naked mole-rat as a model for studying the cholinergic receptor system in ...

  16. Expression of acid-sensing ion channels and selection of reference genes in mouse and naked mole rat.

    Science.gov (United States)

    Schuhmacher, Laura-Nadine; Smith, Ewan St John

    2016-12-13

    Acid-sensing ion channels (ASICs) are a family of ion channels comprised of six subunits encoded by four genes and they are expressed throughout the peripheral and central nervous systems. ASICs have been implicated in a wide range of physiological and pathophysiological processes: pain, breathing, synaptic plasticity and excitotoxicity. Unlike mice and humans, naked mole-rats do not perceive acid as a noxious stimulus, even though their sensory neurons express functional ASICs, likely an adaptation to living in a hypercapnic subterranean environment. Previous studies of ASIC expression in the mammalian nervous system have often not examined all subunits, or have failed to adequately quantify expression between tissues; to date there has been no attempt to determine ASIC expression in the central nervous system of the naked mole-rat. Here we perform a geNorm study to identify reliable housekeeping genes in both mouse and naked mole-rat and then use quantitative real-time PCR to estimate the relative amounts of ASIC transcripts in different tissues of both species. We identify RPL13A (ribosomal protein L13A) and CANX (calnexin), and β-ACTIN and EIF4A (eukaryotic initiation factor 4a) as being the most stably expressed housekeeping genes in mouse and naked mole-rat, respectively. In both species, ASIC3 was most highly expressed in dorsal root ganglia (DRG), and ASIC1a, ASIC2b and ASIC3 were more highly expressed across all brain regions compared to the other subunits. We also show that ASIC4, a proton-insensitive subunit of relatively unknown function, was highly expressed in all mouse tissues apart from DRG and hippocampus, but was by contrast the lowliest expressed ASIC in all naked mole-rat tissues.

  17. Higher fractions theory of fractional hall effect

    International Nuclear Information System (INIS)

    Kostadinov, I.Z.; Popov, V.N.

    1985-07-01

    A theory of fractional quantum Hall effect is generalized to higher fractions. N-particle model interaction is used and the gap is expressed through n-particles wave function. The excitation spectrum in general and the mean field critical behaviour are determined. The Hall conductivity is calculated from first principles. (author)

  18. Microstructure of vapor deposited coatings on curved substrates

    Energy Technology Data Exchange (ETDEWEB)

    Rodgers, Theron M.; Zhao, Hengbei; Wadley, Haydn N. G., E-mail: haydn@virginia.edu [Department of Materials Science and Engineering, University of Virginia, 395 McCormick Rd., P.O. Box 400745, Charlottesville, Virginia 22904 (United States)

    2015-09-15

    Thermal barrier coating systems consisting of a metallic bond coat and ceramic over layer are widely used to extend the life of gas turbine engine components. They are applied using either high-vacuum physical vapor deposition techniques in which vapor atoms rarely experience scattering collisions during propagation to a substrate, or by gas jet assisted (low-vacuum) vapor deposition techniques that utilize scattering from streamlines to enable non-line-of-sight deposition. Both approaches require substrate motion to coat a substrate of complex shape. Here, direct simulation Monte Carlo and kinetic Monte Carlo simulation methods are combined to simulate the deposition of a nickel coating over the concave and convex surfaces of a model airfoil, and the simulation results are compared with those from experimental depositions. The simulation method successfully predicted variations in coating thickness, columnar growth angle, and porosity during both stationary and substrate rotated deposition. It was then used to investigate a wide range of vapor deposition conditions spanning high-vacuum physical vapor deposition to low-vacuum gas jet assisted vapor deposition. The average coating thickness was found to increase initially with gas pressure reaching a maximum at a chamber pressure of 8–10 Pa, but the best coating thickness uniformity was achieved under high vacuum deposition conditions. However, high vacuum conditions increased the variation in the coatings pore volume fraction over the surface of the airfoil. The simulation approach was combined with an optimization algorithm and used to investigate novel deposition concepts to tailor the local coating thickness.

  19. Microstructure of vapor deposited coatings on curved substrates

    International Nuclear Information System (INIS)

    Rodgers, Theron M.; Zhao, Hengbei; Wadley, Haydn N. G.

    2015-01-01

    Thermal barrier coating systems consisting of a metallic bond coat and ceramic over layer are widely used to extend the life of gas turbine engine components. They are applied using either high-vacuum physical vapor deposition techniques in which vapor atoms rarely experience scattering collisions during propagation to a substrate, or by gas jet assisted (low-vacuum) vapor deposition techniques that utilize scattering from streamlines to enable non-line-of-sight deposition. Both approaches require substrate motion to coat a substrate of complex shape. Here, direct simulation Monte Carlo and kinetic Monte Carlo simulation methods are combined to simulate the deposition of a nickel coating over the concave and convex surfaces of a model airfoil, and the simulation results are compared with those from experimental depositions. The simulation method successfully predicted variations in coating thickness, columnar growth angle, and porosity during both stationary and substrate rotated deposition. It was then used to investigate a wide range of vapor deposition conditions spanning high-vacuum physical vapor deposition to low-vacuum gas jet assisted vapor deposition. The average coating thickness was found to increase initially with gas pressure reaching a maximum at a chamber pressure of 8–10 Pa, but the best coating thickness uniformity was achieved under high vacuum deposition conditions. However, high vacuum conditions increased the variation in the coatings pore volume fraction over the surface of the airfoil. The simulation approach was combined with an optimization algorithm and used to investigate novel deposition concepts to tailor the local coating thickness

  20. Lamellar Diblock Copolymer Thin Films during Solvent Vapor Annealing Studied by GISAXS

    DEFF Research Database (Denmark)

    Zhang, Jianqi; Posselt, Dorthe; Smilgies, Detlef-M.

    2014-01-01

    The reorientation of lamellae and the dependence of the lamellar spacing, Dlam, on polymer volume fraction, ϕP, Dlam ∝ ϕP–β, in diblock copolymer thin films during solvent vapor annealing (SVA) are examined by combining white light interferometry (WLI) and grazing-incidence small-angle X-ray scat......The reorientation of lamellae and the dependence of the lamellar spacing, Dlam, on polymer volume fraction, ϕP, Dlam ∝ ϕP–β, in diblock copolymer thin films during solvent vapor annealing (SVA) are examined by combining white light interferometry (WLI) and grazing-incidence small-angle X...

  1. Raman and luminescence spectroscopy of zirconium oxide with the use of the MOLE microprobe

    International Nuclear Information System (INIS)

    Doyle, T.E.; Alvarez, J.L.

    1984-01-01

    Raman and luminescence spectroscopy with the use of the MOLE microprobe has been used to characterize ZrO 2 originating from oxidized fuel-rod cladding in nuclear accidents. Micro-Raman analysis of samples from Three Mile Island Unit 2 and the Power Burst Facility identified tetragonal and cubic ZrO 2 . The tetragonal and cubic phases are high-temperature polymorphs of ZrO 2 and provide information about temperatures and hydrogen formation in the TMI-2 core. The data suggest that the tetragonal ZrO 2 in TMI-2 samples was stabilized by a crystallite size effect, whereas cubic ZrO 2 in PBF debris samples was stabilized by impurities. Luminescence was used to differentiate yttria-stabilized ZrO 2 ceramics and oxidized fuel-rod cladding in PBF debris samples. The ZrO 2 ceramics produced strong, sharp luminescence peaks which indicated the presence of titanium and yttria in the ZrO 2 . Oxidized fuel-rod cladding displayed no luminescence

  2. Influence of the mole penetrator on measurements of heat flow in lunar subsurface layers

    Science.gov (United States)

    Wawrzaszek, Roman; Drogosz, Michal; Seweryn, Karol; Banaszkiewicz, Marek; Grygorczuk, Jerzy

    Measuring the thermal gradient in subsurface layers is a basic method of determination the heat flux from the interior of a planetary body to its surface. In case of the Moon, such measurements complemented with the results of theoretical analysis and modeling can significantly improve our understanding of the thermal and geological evolution of the Moon. In practice, temperature gradient measurements are performed by at least two sensors located at different depths under the surface. These sensors will be attached to a penetrator [1] or to a cable pulled behind the penetrator. In both cases the object that carries the sensors, e.g. penetrator, perturb temperature measurements. In our study we analyze a case of two thermal sensors attached to the ends of 350mm long penetrator made of a composite material. In agreement with the studies of other authors we have found that the penetrator should be placed at the depth of 2-3 meters, where periodic changes of the temperature due to variation of solar flux at the surface are significantly smaller than the error of temperature measurement. The most important result of our analysis is to show how to deconvolve the real gradient of the temperature from the measurements perturbed by the penetrator body. In this way it will be possible to more accurately determine heat flux in the lunar regolith. [1] Grygorczuk J., Seweryn K., Wawrzaszek R., Banaszkiewicz M., Insertion of a Mole Pene-trator -Experimental Results, /39th Lunar and Planetary Science Conference /League City, Texas 2008

  3. Effectiveness of Using Computer-Assisted Supplementary Instruction for Teaching the Mole Concept

    Science.gov (United States)

    Yalçinalp, Serpil; Geban, Ömer; Özkan, Ilker

    This study examined the effect of computer-assisted instruction (CAI), used as a problem-solving supplement to classroom instruction, on students' understanding of chemical formulas and mole concept, their attitudes toward chemistry subjects, and CAI. The objective was to assess the effectiveness of CAI over recitation hours when both teaching methods were used as a supplement to the traditional chemistry instruction. We randomly selected two classes in a secondary school. Each teaching strategy was randomly assigned to one class. The experimental group received supplementary instruction delivered via CAI, while the control group received similar instruction through recitation hours. The data were analyzed using two-way analysis of variance and t-test. It was found that the students who used the CAI accompanied with lectures scored significantly higher than those who attended recitation hours, in terms of school subject achievement in chemistry and attitudes toward chemistry subjects. In addition, there was a significant improvement in the attitudes of students in the experimental group toward the use of computers in a chemistry course. There was no significant difference between the performances of females versus males in each treatment group.Received: 26 April 1994; Revised: 6 April 1995;

  4. Naked Mole Rat Cells Have a Stable Epigenome that Resists iPSC Reprogramming

    Directory of Open Access Journals (Sweden)

    Li Tan

    2017-11-01

    Full Text Available Naked mole rat (NMR is a valuable model for aging and cancer research due to its exceptional longevity and cancer resistance. We observed that the reprogramming efficiency of NMR fibroblasts in response to OSKM was drastically lower than that of mouse fibroblasts. Expression of SV40 LargeT antigen (LT dramatically improved reprogramming of NMR fibroblasts. Inactivation of Rb alone, but not p53, was sufficient to improve reprogramming efficiency, suggesting that NMR chromatin may be refractory to reprogramming. Analysis of the global histone landscape revealed that NMR had higher levels of repressive H3K27 methylation marks and lower levels of activating H3K27 acetylation marks than mouse. ATAC-seq revealed that in NMR, promoters of reprogramming genes were more closed than mouse promoters, while expression of LT led to massive opening of the NMR promoters. These results suggest that NMR displays a more stable epigenome that resists de-differentiation, contributing to the cancer resistance and longevity of this species.

  5. Renal Pathology in a Nontraditional Aging Model: The Naked Mole-Rat (Heterocephalus glaber).

    Science.gov (United States)

    Delaney, M A; Kinsel, M J; Treuting, P M

    2016-03-01

    The naked mole-rat (NMR; Heterocephalus glaber) is growing in popularity as a model for aging research due to its extreme longevity (up to 30 years), highly adapted physiology, and resistance to cancer, particularly when compared with traditional aging models such as laboratory mice and rats. Despite the NMR's seemingly lengthy health span, several age-related lesions have been documented. During a 15-year retrospective evaluation of a zoo-housed population, histologic changes in the kidneys were reported in 127 of 138 (92%) adult NMRs. Of these, renal tubular mineralization was very common (115 of 127; 90.6%) and found in NMRs without concurrent renal lesions (36 of 127; 28.3%). Many of the other described lesions were considered progressive stages of a single process, generally referred to as chronic nephritis or nephropathy, and diagnosed in 73 of 127 (57.5%), while end-stage renal disease was reported in only 12 (9.4%) NMRs. Renal lesions of these NMRs were comparable to disease entities reported in laboratory rats and certain strains of inbred and noninbred mice. Although many lesions of NMR kidneys were similar to those found in aged laboratory rodents, some common urinary diseases were not represented in the examined colonies. The goal of this study was to describe renal lesions in NMRs from a zoologic setting to familiarize investigators and pathologists with an apparently common and presumably age-related disease in this nontraditional model. © The Author(s) 2015.

  6. Naked Mole Rat Induced Pluripotent Stem Cells and Their Contribution to Interspecific Chimera

    Directory of Open Access Journals (Sweden)

    Sang-Goo Lee

    2017-11-01

    Full Text Available Naked mole rats (NMRs are exceptionally long-lived, cancer-resistant rodents. Identifying the defining characteristics of these traits may shed light on aging and cancer mechanisms. Here, we report the generation of induced pluripotent stem cells (iPSCs from NMR fibroblasts and their contribution to mouse-NMR chimeric embryos. Efficient reprogramming could be observed under N2B27+2i conditions. The iPSCs displayed a characteristic morphology, expressed pluripotent markers, formed embryoid bodies, and showed typical differentiation patterns. Interestingly, NMR embryonic fibroblasts and the derived iPSCs had propensity for a tetraploid karyotype and were resistant to forming teratomas, but within mouse blastocysts they contributed to both interspecific placenta and fetus. Gene expression patterns of NMR iPSCs were more similar to those of human than mouse iPSCs. Overall, we uncovered unique features of NMR iPSCs and report a mouse-NMR chimeric model. The iPSCs and associated cell culture systems can be used for a variety of biological and biomedical applications.

  7. Functional characteristics of the naked mole rat μ-opioid receptor.

    Directory of Open Access Journals (Sweden)

    Melanie Busch-Dienstfertig

    Full Text Available While humans and most animals respond to µ-opioid receptor (MOR agonists with analgesia and decreased aggression, in the naked mole rat (NMR opioids induce hyperalgesia and severe aggression. Single nucleotide polymorphisms in the human mu-opioid receptor gene (OPRM1 can underlie altered behavioral responses to opioids. Therefore, we hypothesized that the primary structure of the NMR MOR may differ from other species. Sequencing of the NMR oprm1 revealed strong homology to other mammals, but exposed three unique amino acids that might affect receptor-ligand interactions. The NMR and rat oprm1 sequences were cloned into mammalian expression vectors and transfected into HEK293 cells. Radioligand binding and 3'-5'-cyclic adenosine monophosphate (cAMP enzyme immunoassays were used to compare opioid binding and opioid-mediated cAMP inhibition. At normalized opioid receptor protein levels we detected significantly lower [3H]DAMGO binding to NMR compared to rat MOR, but no significant difference in DAMGO-induced cAMP inhibition. Strong DAMGO-induced MOR internalization was detectable using radioligand binding and confocal imaging in HEK293 cells expressing rat or NMR receptor, while morphine showed weak or no effects. In summary, we found minor functional differences between rat and NMR MOR suggesting that other differences e.g. in anatomical distribution of MOR underlie the NMR's extreme reaction to opioids.

  8. Antagonistic Coevolution Drives Whack-a-Mole Sensitivity in Gene Regulatory Networks.

    Directory of Open Access Journals (Sweden)

    Jeewoen Shin

    2015-10-01

    Full Text Available Robustness, defined as tolerance to perturbations such as mutations and environmental fluctuations, is pervasive in biological systems. However, robustness often coexists with its counterpart, evolvability--the ability of perturbations to generate new phenotypes. Previous models of gene regulatory network evolution have shown that robustness evolves under stabilizing selection, but it is unclear how robustness and evolvability will emerge in common coevolutionary scenarios. We consider a two-species model of coevolution involving one host and one parasite population. By using two interacting species, key model parameters that determine the fitness landscapes become emergent properties of the model, avoiding the need to impose these parameters externally. In our study, parasites are modeled on species such as cuckoos where mimicry of the host phenotype confers high fitness to the parasite but lower fitness to the host. Here, frequent phenotype changes are favored as each population continually adapts to the other population. Sensitivity evolves at the network level such that point mutations can induce large phenotype changes. Crucially, the sensitive points of the network are broadly distributed throughout the network and continually relocate. Each time sensitive points in the network are mutated, new ones appear to take their place. We have therefore named this phenomenon "whack-a-mole" sensitivity, after a popular fun park game. We predict that this type of sensitivity will evolve under conditions of strong directional selection, an observation that helps interpret existing experimental evidence, for example, during the emergence of bacterial antibiotic resistance.

  9. Mola hidatiforme e doença trofoblástica gestacional Hydatidiform mole and gestational trophoblastic disease

    Directory of Open Access Journals (Sweden)

    Jurandyr Moreira de Andrade

    2009-02-01

    Full Text Available A mola hidatiforme é uma complicação relativamente infrequente da gravidez, mas com potencial para evolução para formas que necessitam de tratamento sistêmico e podem ser ameaçadoras da vida. Sob a denominação de mola hidatiforme há duas entidades histopatológicas e clínicas: a mola parcial e a completa. As diferenças entre estas duas formas são importantes, devido ao risco de evolução para formas persistentes, ou seja, mais alto para as completas. O diagnóstico da mola hidatiforme, seu tratamento e seguimento após o tratamento inicial sofreram alterações importantes nos últimos anos. O número de pacientes assintomáticas tem aumentado devido ao emprego de ultrassonografia no início da gravidez. Para a resolução da mola hidatiforme é necessário evitar o emprego de medicamentos que induzam contrações uterinas e usar a vácuo-aspiração. Deve ser prescrito o método contraceptivo hormonal logo após o esvaziamento da mola. O seguimento é baseado nas dosagens seriadas semanais de gonadotrofinas coriônicas. É importante que o método empregado detecte todas as formas das gonadotrofinas coriônicas (molécula intacta, hiperglicosilada, subunidade β livre e fragmento central da subunidade β.The hydatiform mole is a relatively rare pregnancy complication, but with potential to evolve to forms which need systemic treatment and can be a threat to life. There are two histopathological and clinical entities under the name of hydatiform mole: the partial and the complete mole. The differences between the two forms are important due to risk of evolution to persistent forms, which is higher for the complete moles. The diagnosis, treatment and follow-up of hydatiform mole have been under important changes in the last years. The number of asymptomatic patients has increased, due to the use of ultrasonography at the onset of pregnancy. The use of medication that induces uterine contractions must be avoided, and vacuum

  10. Asphalt chemical fractionation

    International Nuclear Information System (INIS)

    Obando P, Klever N.

    1998-01-01

    Asphalt fractionation were carried out in the Esmeraldas Oil Refinery using n-pentane, SiO 2 and different mixture of benzene- methane. The fractions obtained were analyzed by Fourier's Transformed Infrared Spectrophotometry (FTIR)

  11. Framework for simulating droplet vaporization in turbulent flows

    Science.gov (United States)

    Palmore, John; Desjardins, Olivier

    2017-11-01

    A framework for performing direct numerical simulations of droplet vaporization is presented. The work is motivated by spray combustion in engines wherein fuel droplets vaporize in a turbulent gas flow. The framework is built into a conservative finite volume code for simulating low Mach number turbulent multiphase flows. Phase tracking is performed using a discretely conservative geometric volume of fluid method, while the transport of mass fraction and temperature is performed using the BQUICK scheme. Special attention is given to the implementation of transport equations near the interface to ensure the consistency between fluxes of mass, momentum, and scalars. The effect of evaporation on the flow appears as a system of coupled source terms which depend on the local thermodynamic equilibrium between the phases. The sources are implemented implicitly using an unconditionally stable, monotone scheme. Two methodologies for resolving the system's thermodynamic equilibrium are compared for their accuracy, robustness, and computational expense. Verification is performed by comparing results to known solutions in one and three dimensions. Finally, simulations of droplets vaporizing in turbulence are demonstrated, and trends for mass fraction and temperature fields are discussed.

  12. Thermal plasma chemical vapor deposition

    International Nuclear Information System (INIS)

    Heberlein, J.; Pfender, E.

    1993-01-01

    Thermal plasmas, with temperatures up to and even exceeding 10 4 K, are capable of producing high density vapor phase precursors for the deposition of relatively thick films. Although this technology is still in its infancy, it will fill the void between the relatively slow deposition processes such as physical vapor deposition and the high rate thermal spray deposition processes. In this chapter, the present state-of-the-art of this field is reviewed with emphasis on the various types of reactors proposed for this emerging technology. Only applications which attracted particular attention, namely diamond and high T c superconducting film deposition, are discussed in greater detail. (orig.)

  13. Smarandache Continued Fractions

    OpenAIRE

    Ibstedt, H.

    2001-01-01

    The theory of general continued fractions is developed to the extent required in order to calculate Smarandache continued fractions to a given number of decimal places. Proof is given for the fact that Smarandache general continued fractions built with positive integer Smarandache sequences baving only a finite number of terms equal to 1 is convergent. A few numerical results are given.

  14. Waste Tank Vapor Project: Tank vapor database development

    International Nuclear Information System (INIS)

    Seesing, P.R.; Birn, M.B.; Manke, K.L.

    1994-09-01

    The objective of the Tank Vapor Database (TVD) Development task in FY 1994 was to create a database to store, retrieve, and analyze data collected from the vapor phase of Hanford waste tanks. The data needed to be accessible over the Hanford Local Area Network to users at both Westinghouse Hanford Company (WHC) and Pacific Northwest Laboratory (PNL). The data were restricted to results published in cleared reports from the laboratories analyzing vapor samples. Emphasis was placed on ease of access and flexibility of data formatting and reporting mechanisms. Because of time and budget constraints, a Rapid Application Development strategy was adopted by the database development team. An extensive data modeling exercise was conducted to determine the scope of information contained in the database. a A SUN Sparcstation 1000 was procured as the database file server. A multi-user relational database management system, Sybase reg-sign, was chosen to provide the basic data storage and retrieval capabilities. Two packages were chosen for the user interface to the database: DataPrism reg-sign and Business Objects trademark. A prototype database was constructed to provide the Waste Tank Vapor Project's Toxicology task with summarized and detailed information presented at Vapor Conference 4 by WHC, PNL, Oak Ridge National Laboratory, and Oregon Graduate Institute. The prototype was used to develop a list of reported compounds, and the range of values for compounds reported by the analytical laboratories using different sample containers and analysis methodologies. The prototype allowed a panel of toxicology experts to identify carcinogens and compounds whose concentrations were within the reach of regulatory limits. The database and user documentation was made available for general access in September 1994

  15. RNA sequencing reveals differential expression of mitochondrial and oxidation reduction genes in the long-lived naked mole-rat when compared to mice.

    Science.gov (United States)

    Yu, Chuanfei; Li, Yang; Holmes, Andrew; Szafranski, Karol; Faulkes, Chris G; Coen, Clive W; Buffenstein, Rochelle; Platzer, Matthias; de Magalhães, João Pedro; Church, George M

    2011-01-01

    The naked mole-rat (Heterocephalus glaber) is a long-lived, cancer resistant rodent and there is a great interest in identifying the adaptations responsible for these and other of its unique traits. We employed RNA sequencing to compare liver gene expression profiles between naked mole-rats and wild-derived mice. Our results indicate that genes associated with oxidoreduction and mitochondria were expressed at higher relative levels in naked mole-rats. The largest effect is nearly 300-fold higher expression of epithelial cell adhesion molecule (Epcam), a tumour-associated protein. Also of interest are the protease inhibitor, alpha2-macroglobulin (A2m), and the mitochondrial complex II subunit Sdhc, both ageing-related genes found strongly over-expressed in the naked mole-rat. These results hint at possible candidates for specifying species differences in ageing and cancer, and in particular suggest complex alterations in mitochondrial and oxidation reduction pathways in the naked mole-rat. Our differential gene expression analysis obviated the need for a reference naked mole-rat genome by employing a combination of Illumina/Solexa and 454 platforms for transcriptome sequencing and assembling transcriptome contigs of the non-sequenced species. Overall, our work provides new research foci and methods for studying the naked mole-rat's fascinating characteristics.

  16. Adult naked mole-rat brain retains the NMDA receptor subunit GluN2D associated with hypoxia tolerance in neonatal mammals.

    Science.gov (United States)

    Peterson, Bethany L; Park, Thomas J; Larson, John

    2012-01-11

    Adult naked mole-rats show a number of systemic adaptations to a crowded underground habitat that is low in oxygen and high in carbon dioxide. Remarkably, brain slice tissue from adult naked mole-rats also is extremely tolerant to oxygen deprivation as indicated by maintenance of synaptic transmission under hypoxic conditions as well as by a delayed neuronal depolarization during anoxia. These characteristics resemble hypoxia tolerance in brain slices from neonates in a variety of mammal species. An important component of neonatal tolerance to hypoxia involves the subunit composition of NMDA receptors. Neonates have a high proportion of NMDA receptors with GluN2D subunits which are protective because they retard calcium entry into neurons during hypoxic episodes. Therefore, we hypothesized that adult naked mole-rats retain a protective, neonatal-like, NMDA receptor subunit profile. We used immunoblotting to assess age-related changes in NMDA receptor subunits in naked mole-rats and mice. The results show that adult naked mole-rat brain retains a much greater proportion of the hypoxia-protective GluN2D subunit compared to adult mice. However, age-related changes in other subunits (GluN2A and GluN2B) from the neonatal period to adulthood were comparable in mice and naked mole-rats. Hence, adult naked mole-rat brain only retains the neonatal NMDA receptor subunit that is associated with hypoxia tolerance. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  17. RNA sequencing reveals differential expression of mitochondrial and oxidation reduction genes in the long-lived naked mole-rat when compared to mice.

    Directory of Open Access Journals (Sweden)

    Chuanfei Yu

    Full Text Available The naked mole-rat (Heterocephalus glaber is a long-lived, cancer resistant rodent and there is a great interest in identifying the adaptations responsible for these and other of its unique traits. We employed RNA sequencing to compare liver gene expression profiles between naked mole-rats and wild-derived mice. Our results indicate that genes associated with oxidoreduction and mitochondria were expressed at higher relative levels in naked mole-rats. The largest effect is nearly 300-fold higher expression of epithelial cell adhesion molecule (Epcam, a tumour-associated protein. Also of interest are the protease inhibitor, alpha2-macroglobulin (A2m, and the mitochondrial complex II subunit Sdhc, both ageing-related genes found strongly over-expressed in the naked mole-rat. These results hint at possible candidates for specifying species differences in ageing and cancer, and in particular suggest complex alterations in mitochondrial and oxidation reduction pathways in the naked mole-rat. Our differential gene expression analysis obviated the need for a reference naked mole-rat genome by employing a combination of Illumina/Solexa and 454 platforms for transcriptome sequencing and assembling transcriptome contigs of the non-sequenced species. Overall, our work provides new research foci and methods for studying the naked mole-rat's fascinating characteristics.

  18. Estimated vapor pressure for WTP process streams

    Energy Technology Data Exchange (ETDEWEB)

    Pike, J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Poirier, M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-01-01

    Design assumptions during the vacuum refill phase of the Pulsed Jet Mixers (PJMs) in the Hanford Waste Treatment and Immobilization Plant (WTP) equate the vapor pressure of all process streams to that of water when calculating the temperature at which the vacuum refill is reduced or eliminated. WTP design authority asked the authors to assess this assumption by performing calculations on proposed feed slurries to calculate the vapor pressure as a function of temperature. The vapor pressure was estimated for each WTP waste group. The vapor pressure suppression caused by dissolved solids is much greater than the increase caused by organic components such that the vapor pressure for all of the waste group compositions is less than that of pure water. The vapor pressure for each group at 145°F ranges from 81% to 98% of the vapor pressure of water. If desired, the PJM could be operated at higher temperatures for waste groups with high dissolved solids that suppress vapor pressure. The SO4 group with the highest vapor pressure suppression could be operated up to 153°F before reaching the same vapor pressure of water at 145°F. However, most groups would reach equivalent vapor pressure at 147 to 148°F. If any of these waste streams are diluted, the vapor pressure can exceed the vapor pressure of water at mass dilution ratios greater than 10, but the overall effect is less than 0.5%.

  19. Vapor generation methods for explosives detection research

    Energy Technology Data Exchange (ETDEWEB)

    Grate, Jay W.; Ewing, Robert G.; Atkinson, David A.

    2012-12-01

    The generation of calibrated vapor samples of explosives compounds remains a challenge due to the low vapor pressures of the explosives, adsorption of explosives on container and tubing walls, and the requirement to manage (typically) multiple temperature zones as the vapor is generated, diluted, and delivered. Methods that have been described to generate vapors can be classified as continuous or pulsed flow vapor generators. Vapor sources for continuous flow generators are typically explosives compounds supported on a solid support, or compounds contained in a permeation or diffusion device. Sources are held at elevated isothermal temperatures. Similar sources can be used for pulsed vapor generators; however, pulsed systems may also use injection of solutions onto heated surfaces with generation of both solvent and explosives vapors, transient peaks from a gas chromatograph, or vapors generated by s programmed thermal desorption. This article reviews vapor generator approaches with emphasis on the method of generating the vapors and on practical aspects of vapor dilution and handling. In addition, a gas chromatographic system with two ovens that is configurable with up to four heating ropes is proposed that could serve as a single integrated platform for explosives vapor generation and device testing. Issues related to standards, calibration, and safety are also discussed.

  20. Expression patterns of ERVWE1/Syncytin-1 and other placentally expressed human endogenous retroviruses along the malignant transformation process of hydatidiform moles.

    Science.gov (United States)

    Bolze, Pierre-Adrien; Patrier, Sophie; Cheynet, Valérie; Oriol, Guy; Massardier, Jérôme; Hajri, Touria; Guillotte, Michèle; Bossus, Marc; Sanlaville, Damien; Golfier, François; Mallet, François

    2016-03-01

    Up to 20% of hydatidiform moles are followed by malignant transformation in gestational trophoblastic neoplasia and require chemotherapy. Syncytin-1 is involved in human placental morphogenesis and is also expressed in various cancers. We assessed the predictive value of the expression of Syncytin-1 and its interactants in the malignant transformation process of hydatidiform moles. Syncytin-1 glycoprotein was localized by immunohistochemistry in hydatidiform moles, gestational trophoblastic neoplasia and control placentas. The transcription levels of its locus ERVWE1, its interaction partners (hASCT1, hASCT2, TLR4 and DC-SIGN) and two loci (ERVFRDE1 and ERV3) involved the expression of other placental envelopes were assessed by real-time PCR. Syncytin-1 glycoprotein was expressed in syncytiotrophoblast of hydatidiform moles with an apical enhancement when compared with normal placentas. Moles with further malignant transformation had a higher staining intensity of Syncytin-1 surface unit C-terminus but the transcription level of its locus ERVWE1 was not different from that of moles with further remission and normal placentas. hASCT1 and TLR4, showed lower transcription levels in complete moles when compared to normal placentas. ERVWE1, ERVFRDE1 and ERV3 transcription was down-regulated in hydatidiform moles and gestational trophoblastic neoplasia. Variations of Syncytin-1 protein localization and down-regulation of hASCT1 and TLR4 transcription are likely to reflect altered functions of Syncytin-1 in the premalignant context of complete moles. The reduced transcription in gestational trophoblastic diseases of ERVWE1, ERVFRDE1 and ERV3, which expression during normal pregnancy is differentially regulated by promoter region methylation, suggest a joint dysregulation mechanism in malignant context. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Fractional smith chart theory

    KAUST Repository

    Shamim, Atif

    2011-03-01

    For the first time, a generalized Smith chart is introduced here to represent fractional order circuit elements. It is shown that the standard Smith chart is a special case of the generalized fractional order Smith chart. With illustrations drawn for both the conventional integer based lumped elements and the fractional elements, a graphical technique supported by the analytical method is presented to plot impedances on the fractional Smith chart. The concept is then applied towards impedance matching networks, where the fractional approach proves to be much more versatile and results in a single element matching network for a complex load as compared to the two elements in the conventional approach. © 2010 IEEE.

  2. Vapor generating unit blowdown arrangement

    International Nuclear Information System (INIS)

    McDonald, B.N.

    1978-01-01

    A vapor generating unit having a U-shaped tube bundle is provided with an orificed downcomer shroud and a fluid flow distribution plate between the lower hot and cold leg regions to promote fluid entrained sediment deposition in proximity to an apertured blowdown pipe

  3. High specific activity N-Acetyl-3H-α-Aspartyl- L-Glutamic at micro mole scale

    International Nuclear Information System (INIS)

    Suarez, C.

    1984-01-01

    High specific activity N-Acetyl-3 H - α -Aspartyl-I-Glutamic acid at micro mole scale in prepared acetylating L- α -Aspartyl-L-glutamic with 3 H -acetic anhydride in re distilled toluene. The product le purified through cationic and anionic columns. The radiochemical purity as determined by thin-layer chromatography is greater then 99% at the time preparation. (Author) 5 refs

  4. Rediscovery Of The Northern Mole Vole, Ellobius Talpinus (Rodentia, Cricetidae, At The Western Bank Of The Dnipro River, Ukraine

    Directory of Open Access Journals (Sweden)

    Rusin M.

    2015-06-01

    Full Text Available Ellobius talpinus was supposed to become extinct from the westernbank of the river Dnipro. Aft er 50 years the species was found again in Dnipropetrovsk and Kherson Region. The brief description of the current distribution of the northern mole vole to the west of the Dnipro is given. Altogether 11 localities were found. The rediscovered populations may be treated as endangered in the region.

  5. Reduced Utilization of Selenium by Naked Mole Rats Due to a Specific Defect in GPx1 Expression*

    OpenAIRE

    Kasaikina, Marina V.; Lobanov, Alexei V.; Malinouski, Mikalai Y.; Lee, Byung Cheon; Seravalli, Javier; Fomenko, Dmitri E.; Turanov, Anton A.; Finney, Lydia; Vogt, Stefan; Park, Thomas J.; Miller, Richard A.; Hatfield, Dolph L.; Gladyshev, Vadim N.

    2011-01-01

    Naked mole rat (MR) Heterocephalus glaber is a rodent model of delayed aging because of its unusually long life span (>28 years). It is also not known to develop cancer. In the current work, tissue imaging by x-ray fluorescence microscopy and direct analyses of trace elements revealed low levels of selenium in the MR liver and kidney, whereas MR and mouse brains had similar selenium levels. This effect was not explained by uniform selenium deficiency because methionine sulfoxide reductase act...

  6. Challenging the inbreeding hypothesis in a eusocial mammal: population genetics of the naked mole-rat, Heterocephalus glaber.

    Science.gov (United States)

    Ingram, Colleen M; Troendle, Nicholas J; Gill, Clare A; Braude, Stanton; Honeycutt, Rodney L

    2015-10-01

    The role of genetic relatedness in the evolution of eusociality has been the topic of much debate, especially when contrasting eusocial insects with vertebrates displaying reproductive altruism. The naked mole-rat, Heterocephalus glaber, was the first described eusocial mammal. Although this discovery was based on an ecological constraints model of eusocial evolution, early genetic studies reported high levels of relatedness in naked mole-rats, providing a compelling argument that low dispersal rates and consanguineous mating (inbreeding as a mating system) are the driving forces for the evolution of this eusocial species. One caveat to accepting this long-held view is that the original genetic studies were based on limited sampling from the species' geographic distribution. A growing body of evidence supports a contrary view, with the original samples not representative of the species-rather reflecting a single founder event, establishing a small population south of the Athi River. Our study is the first to address these competing hypotheses by examining patterns of molecular variation in colonies sampled from north and south of the Athi and Tana rivers, which based on our results, serve to isolate genetically distinct populations of naked mole-rats. Although colonies south of the Athi River share a single mtDNA haplotype and are fixed at most microsatellite loci, populations north of the Athi River are considerably more variable. Our findings support the position that the low variation observed in naked mole-rat populations south of the Athi River reflects a founder event, rather than a consequence of this species' unusual mating system. © 2015 John Wiley & Sons Ltd.

  7. Fractional factorial plans

    CERN Document Server

    Dey, Aloke

    2009-01-01

    A one-stop reference to fractional factorials and related orthogonal arrays.Presenting one of the most dynamic areas of statistical research, this book offers a systematic, rigorous, and up-to-date treatment of fractional factorial designs and related combinatorial mathematics. Leading statisticians Aloke Dey and Rahul Mukerjee consolidate vast amounts of material from the professional literature--expertly weaving fractional replication, orthogonal arrays, and optimality aspects. They develop the basic theory of fractional factorials using the calculus of factorial arrangements, thereby providing a unified approach to the study of fractional factorial plans. An indispensable guide for statisticians in research and industry as well as for graduate students, Fractional Factorial Plans features: * Construction procedures of symmetric and asymmetric orthogonal arrays. * Many up-to-date research results on nonexistence. * A chapter on optimal fractional factorials not based on orthogonal arrays. * Trend-free plans...

  8. Fractional Dynamics and Control

    CERN Document Server

    Machado, José; Luo, Albert

    2012-01-01

    Fractional Dynamics and Control provides a comprehensive overview of recent advances in the areas of nonlinear dynamics, vibration and control with analytical, numerical, and experimental results. This book provides an overview of recent discoveries in fractional control, delves into fractional variational principles and differential equations, and applies advanced techniques in fractional calculus to solving complicated mathematical and physical problems.Finally, this book also discusses the role that fractional order modeling can play in complex systems for engineering and science. Discusses how fractional dynamics and control can be used to solve nonlinear science and complexity issues Shows how fractional differential equations and models can be used to solve turbulence and wave equations in mechanics and gravity theories and Schrodinger’s equation  Presents factional relaxation modeling of dielectric materials and wave equations for dielectrics  Develops new methods for control and synchronization of...

  9. The Insulin-Like Growth Factor System in the Long-Lived Naked Mole-Rat.

    Directory of Open Access Journals (Sweden)

    Malene Brohus

    Full Text Available Naked mole-rats (Heterocephalus glaber (NMRs are the longest living rodents known. They show negligible senescence, and are resistant to cancers and certain damaging effects associated with aging. The insulin-like growth factors (IGFs have pluripotent actions, influencing growth processes in virtually every system of the body. They are established contributors to the aging process, confirmed by the demonstration that decreased IGF signaling results in life-extending effects in a variety of species. The IGFs are likewise involved in progression of cancers by mediating survival signals in malignant cells. This report presents a full characterization of the IGF system in the NMR: ligands, receptors, IGF binding proteins (IGFBPs, and IGFBP proteases. A particular emphasis was placed on the IGFBP protease, pregnancy-associated plasma protein-A (PAPP-A, shown to be an important lifespan modulator in mice. Comparisons of IGF-related genes in the NMR with human and murine sequences indicated no major differences in essential parts of the IGF system, including PAPP-A. The protease was shown to possess an intact active site despite the report of a contradictory genome sequence. Furthermore, PAPP-A was expressed and translated in NMRs cells and retained IGF-dependent proteolytic activity towards IGFBP-4 and IGF-independent activity towards IGFBP-5. However, experimental data suggest differential regulatory mechanisms for PAPP-A expression in NMRs than those described in humans and mice. This overall description of the IGF system in the NMR represents an initial step towards elucidating the complex molecular mechanisms underlying longevity, and how these animals have evolved to ensure a delayed and healthy aging process.

  10. Initial Case Reports of Cancer in Naked Mole-rats (Heterocephalus glaber).

    Science.gov (United States)

    Delaney, M A; Ward, J M; Walsh, T F; Chinnadurai, S K; Kerns, K; Kinsel, M J; Treuting, P M

    2016-05-01

    Naked mole-rats (NMRs;Heterocephalus glaber) are highly adapted, eusocial rodents renowned for their extreme longevity and resistance to cancer. Because cancer has not been formally described in this species, NMRs have been increasingly utilized as an animal model in aging and cancer research. We previously reported the occurrence of several age-related diseases, including putative pre-neoplastic lesions, in zoo-housed NMR colonies. Here, we report for the first time 2 cases of cancer in zoo-housed NMRs. In Case No. 1, we observed a subcutaneous mass in the axillary region of a 22-year-old male NMR, with histologic, immunohistochemical (pancytokeratin positive, rare p63 immunolabeling, and smooth muscle actin negative), and ultrastructural characteristics of an adenocarcinoma possibly of mammary or salivary origin. In Case No. 2, we observed a densely cellular, poorly demarcated gastric mass of polygonal cells arranged in nests with positive immunolabeling for synaptophysin and chromogranin indicative of a neuroendocrine carcinoma in an approximately 20-year-old male NMR. We also include a brief discussion of other proliferative growths and pre-cancerous lesions diagnosed in 1 zoo colony. Although these case reports do not alter the longstanding observation of cancer resistance, they do raise questions about the scope of cancer resistance and the interpretation of biomedical studies in this model. These reports also highlight the benefit of long-term disease investigations in zoo-housed populations to better understand naturally occurring disease processes in species used as models in biomedical research. © The Author(s) 2016.

  11. The Insulin-Like Growth Factor System in the Long-Lived Naked Mole-Rat.

    Science.gov (United States)

    Brohus, Malene; Gorbunova, Vera; Faulkes, Chris G; Overgaard, Michael T; Conover, Cheryl A

    2015-01-01

    Naked mole-rats (Heterocephalus glaber) (NMRs) are the longest living rodents known. They show negligible senescence, and are resistant to cancers and certain damaging effects associated with aging. The insulin-like growth factors (IGFs) have pluripotent actions, influencing growth processes in virtually every system of the body. They are established contributors to the aging process, confirmed by the demonstration that decreased IGF signaling results in life-extending effects in a variety of species. The IGFs are likewise involved in progression of cancers by mediating survival signals in malignant cells. This report presents a full characterization of the IGF system in the NMR: ligands, receptors, IGF binding proteins (IGFBPs), and IGFBP proteases. A particular emphasis was placed on the IGFBP protease, pregnancy-associated plasma protein-A (PAPP-A), shown to be an important lifespan modulator in mice. Comparisons of IGF-related genes in the NMR with human and murine sequences indicated no major differences in essential parts of the IGF system, including PAPP-A. The protease was shown to possess an intact active site despite the report of a contradictory genome sequence. Furthermore, PAPP-A was expressed and translated in NMRs cells and retained IGF-dependent proteolytic activity towards IGFBP-4 and IGF-independent activity towards IGFBP-5. However, experimental data suggest differential regulatory mechanisms for PAPP-A expression in NMRs than those described in humans and mice. This overall description of the IGF system in the NMR represents an initial step towards elucidating the complex molecular mechanisms underlying longevity, and how these animals have evolved to ensure a delayed and healthy aging process.

  12. Transcriptome sequencing of the naked mole rat (Heterocephalus glaber and identification of hypoxia tolerance genes

    Directory of Open Access Journals (Sweden)

    Bang Xiao

    2017-12-01

    Full Text Available The naked mole rat (NMR; Heterocephalus glaber is a small rodent species found in regions of Kenya, Ethiopia and Somalia. It has a high tolerance for hypoxia and is thus considered one of the most important natural models for studying hypoxia tolerance mechanisms. The various mechanisms underlying the NMR's hypoxia tolerance are beginning to be understood at different levels of organization, and next-generation sequencing methods promise to expand this understanding to the level of gene expression. In this study, we examined the sequence and transcript abundance data of the muscle transcriptome of NMRs exposed to hypoxia using the Illumina HiSeq 2500 system to clarify the possible genomic adaptive responses to the hypoxic underground surroundings. The RNA-seq raw FastQ data were mapped against the NMR genome. We identified 2337 differentially expressed genes (DEGs by comparison of the hypoxic and control groups. Functional annotation of the DEGs by gene ontology (GO analysis revealed enrichment of hypoxia stress-related GO categories, including ‘biological regulation’, ‘cellular process’, ‘ion transport’ and ‘cell-cell signaling’. Enrichment of DEGs in signaling pathways was analyzed against the Kyoto Encyclopedia of Genes and Genomes (KEGG database to identify possible interactions between DEGs. The results revealed significant enrichment of DEGs in focal adhesion, the mitogen-activated protein kinase (MAPK signaling pathway and the glycine, serine and threonine metabolism pathway. Furthermore, inhibition of DEGs (STMN1, MAPK8IP1 and MAPK10 expression induced apoptosis and arrested cell growth in NMR fibroblasts following hypoxia. Thus, this global transcriptome analysis of NMRs can provide an important genetic resource for the study of hypoxia tolerance in mammals. Furthermore, the identified DEGs may provide important molecular targets for biomedical research into therapeutic strategies for stroke and cardiovascular diseases.

  13. The role of fragmentation mechanism in large-scale vapor explosions

    International Nuclear Information System (INIS)

    Liu, Jie

    2003-01-01

    A non-equilibrium, multi-phase, multi-component code PROVER-I is developed for propagation phase of vapor explosion. Two fragmentation models are used. The hydrodynamic fragmentation model is the same as Fletcher's one. A new thermal fragmentation model is proposed with three kinds of time scale for modeling instant fragmentation, spontaneous nucleation fragmentation and normal boiling fragmentation. The role of fragmentation mechanisms is investigated by the simulations of the pressure wave propagation and energy conversion ratio of ex-vessel vapor explosion. The spontaneous nucleation fragmentation results in a much higher pressure peak and a larger energy conversion ratio than hydrodynamic fragmentation. The instant fragmentation gives a slightly larger energy conversion ratio than spontaneous nucleation fragmentation, and the normal boiling fragmentation results in a smaller energy conversion ratio. The detailed analysis of the structure of pressure wave makes it clear that thermal detonation exists only under the thermal fragmentation circumstance. The high energy conversion ratio is obtained in a small vapor volume fraction. However, in larger vapor volume fraction conditions, the vapor explosion is weak. In a large-scale vapor explosion, the hydrodynamic fragmentation is essential when the pressure wave becomes strong, so a small energy conversion ratio is expected. (author)

  14. A new definition for the mole based on the Avogadro constant: a journey from physics to chemistry.

    Science.gov (United States)

    Milton, Martin J T

    2011-10-28

    The mole is the most recent addition to the set of base units that form the International System of Units, although its pre-cursor the 'gram-molecule', had been in use by both physicists and chemists for more than 120 years. A proposal has been published recently to establish a new definition for the mole based on a fixed value for the Avogadro constant. This would introduce consistent relative uncertainties for the molar and the atomic masses while making no change to the system of relative atomic masses ('atomic weights'). Although the proposal would have little impact on the measurement uncertainty of practical work, it has stimulated considerable debate about the mole and the nature of the quantity amount of substance. In this paper, the rationale for the new definition is explained against the background of changes in the way the quantity amount of substance has been used, from its first use during the early development of thermodynamics through to the use of the 'number of gram-molecules' at the end of the nineteenth century.

  15. Naked mole-rats maintain healthy skeletal muscle and Complex IV mitochondrial enzyme function into old age.

    Science.gov (United States)

    Stoll, Elizabeth A; Karapavlovic, Nevena; Rosa, Hannah; Woodmass, Michael; Rygiel, Karolina; White, Kathryn; Turnbull, Douglass M; Faulkes, Chris G

    2016-12-19

    The naked mole-rat (NMR) Heterocephalus glaber is an exceptionally long-lived rodent, living up to 32 years in captivity. This extended lifespan is accompanied by a phenotype of negligible senescence, a phenomenon of very slow changes in the expected physiological characteristics with age. One of the many consequences of normal aging in mammals is the devastating and progressive loss of skeletal muscle, termed sarcopenia, caused in part by respiratory enzyme dysfunction within the mitochondria of skeletal muscle fibers. Here we report that NMRs avoid sarcopenia for decades. Muscle fiber integrity and mitochondrial ultrastructure are largely maintained in aged animals. While mitochondrial Complex IV expression and activity remains stable, Complex I expression is significantly decreased. We show that aged naked mole-rat skeletal muscle tissue contains some mitochondrial DNA rearrangements, although the common mitochondrial DNA deletions associated with aging in human and other rodent skeletal muscles are not present. Interestingly, NMR skeletal muscle fibers demonstrate a significant increase in mitochondrial DNA copy number. These results have intriguing implications for the role of mitochondria in aging, suggesting Complex IV, but not Complex I, function is maintained in the long-lived naked mole rat, where sarcopenia is avoided and healthy muscle function is maintained for decades.

  16. Cessation of reproduction-related spine elongation after multiple breeding cycles in female naked mole-rats.

    Science.gov (United States)

    Dengler-Crish, Christine M; Catania, Kenneth C

    2009-01-01

    The breeding female or "queen" naked mole-rat has a uniquely elongated body morphology attributed to the lengthening of the lumbar vertebral column that occurs during pregnancy. It is unknown whether this vertebral growth is a continuous process, or associated only with early reproductive experience. We compared pregnancy-related bone elongation in nascent primiparous queens and established queens to determine if this vertebral expansion was a lifelong process in these females. We also investigated the impact of lactation on vertebral elongation in these mole-rats because it is known to be a time of significant bone loss in other mammals. Our data show that after eight or more pregnancies, established queens no longer experienced a net gain in lumbar spine length over the reproductive cycle, whereas the nascent breeders demonstrated significant spine lengthening over this time. Despite the lack of net spine lengthening in established breeders, our results indicated that these queens still experienced some pregnancy-specific vertebral elongation. In naked mole-rats, pregnancy-induced bone elongation may serve the dual purposes of first lengthening the spine, and then once optimal spine size is achieved, serving as a homeostatic mechanism that prepares the spine for the mineral demands of lactation. Anat Rec, 2009. (c) 2008 Wiley-Liss, Inc.

  17. Retinal S-opsin dominance in Ansell's mole-rats (Fukomys anselli) is a consequence of naturally low serum thyroxine.

    Science.gov (United States)

    Henning, Yoshiyuki; Mladěnková, Nella; Burda, Hynek; Szafranski, Karol; Begall, Sabine

    2018-03-12

    Mammals usually possess a majority of medium-wavelength sensitive (M-) and a minority of short-wavelength sensitive (S-) opsins in the retina, enabling dichromatic vision. Unexpectedly, subterranean rodents from the genus Fukomys exhibit an S-opsin majority, which is exceptional among mammals, albeit with no apparent adaptive value. Because thyroid hormones (THs) are pivotal for M-opsin expression and metabolic rate regulation, we have, for the first time, manipulated TH levels in the Ansell's mole-rat (Fukomys anselli) using osmotic pumps. In Ansell's mole-rats, the TH thyroxine (T4) is naturally low, likely as an adaptation to the harsh subterranean ecological conditions by keeping resting metabolic rate (RMR) low. We measured gene expression levels in the eye, RMR, and body mass (BM) in TH-treated animals. T4 treatment increased both, S- and M-opsin expression, albeit M-opsin expression at a higher degree. However, this plasticity was only given in animals up to approximately 2.5 years. Mass-specific RMR was not affected following T4 treatment, although BM decreased. Furthermore, the T4 inactivation rate is naturally higher in F. anselli compared to laboratory rodents. This is the first experimental evidence that the S-opsin majority in Ansell's mole-rats is a side effect of low T4, which is downregulated to keep RMR low.

  18. Hanford soil partitioning and vapor extraction study

    International Nuclear Information System (INIS)

    Yonge, D.; Hossain, A.; Cameron, R.; Ford, H.; Storey, C.

    1996-07-01

    This report describes the testing and results of laboratory experiments conducted to assist the carbon tetrachloride soil vapor extraction project operating in the 200 West Area of the Hanford Site in Richland, Washington. Vapor-phase adsorption and desorption testing was performed using carbon tetrachloride and Hanford Site soils to estimate vapor-soil partitioning and reasonably achievable carbon tetrachloride soil concentrations during active vapor extractions efforts at the 200 West Area. (CCl 4 is used in Pu recovery from aqueous streams.)

  19. Vapor Pressure Data Analysis and Statistics

    Science.gov (United States)

    2016-12-01

    near 8, 2000, and 200, respectively. The A (or a) value is directly related to vapor pressure and will be greater for high vapor pressure materials...1, (10) where n is the number of data points, Yi is the natural logarithm of the i th experimental vapor pressure value, and Xi is the...VAPOR PRESSURE DATA ANALYSIS AND STATISTICS ECBC-TR-1422 Ann Brozena RESEARCH AND TECHNOLOGY DIRECTORATE

  20. Dividing Fractions: A Pedagogical Technique

    Science.gov (United States)

    Lewis, Robert

    2016-01-01

    When dividing one fraction by a second fraction, invert, that is, flip the second fraction, then multiply it by the first fraction. To multiply fractions, simply multiply across the denominators, and multiply across the numerators to get the resultant fraction. So by inverting the division of fractions it is turned into an easy multiplication of…

  1. Non-invasive assessment of glucocorticoid and androgen metabolite levels in cooperatively breeding Damaraland mole-rats (Fukomys damarensis).

    Science.gov (United States)

    Medger, Katarina; Bennett, Nigel C; Lutermann, Heike; Ganswindt, Andre

    2018-05-18

    Dominant females of cooperative breeding species often use aggression to suppress reproduction of subordinate females, resulting in subordinates experiencing stress-related increases in glucocorticoid levels, which may cause reproductive down-regulation. This would suggest a general pattern with higher glucocorticoid levels in subordinate compared to dominant individuals; however, the opposite was found in a number of cooperatively breeding species. Furthermore, breeding females of the cooperatively breeding Damaraland mole-rats (Fukomys damarensis) exhibit very high androgen concentrations during the wet season, presumably to support their breeding monopoly. Hormone analysis in Damaraland mole-rats have typically been measured using plasma and urine, but faecal analysis offers additional advantages especially for field studies on this species. The present study examines the suitability of Damaraland mole-rat faecal samples for determining glucocorticoid metabolite (fGCM) and androgen metabolite (fAM) concentrations using enzyme immunoassays. Using these assays, we further evaluated the effects of breeding status on fGCM and fAM concentrations in wild-caught and captive Damaraland mole-rats. Wild-caught breeding and non-breeding males and females exhibited no differences in fAM concentrations. Immunoreactive fGCM concentrations were only high in male breeders and comparatively low in non-breeders and breeding females. Concentrations of fAMs and fGCMs were similar in captive males and females, but fAM concentrations were elevated in captive compared to wild-caught individuals, which may be related to a higher reproductive activity due to removal from the breeding female. The relatively uniform fAM and fGCM concentrations found in wild-caught mole-rats may be explained by a stable colony structure during the dry season during which this study was conducted. Limited dispersal opportunities result in lower aggression and stress levels within a colony and as a result

  2. Estimating enthalpy of vaporization from vapor pressure using Trouton's rule.

    Science.gov (United States)

    MacLeod, Matthew; Scheringer, Martin; Hungerbühler, Konrad

    2007-04-15

    The enthalpy of vaporization of liquids and subcooled liquids at 298 K (delta H(VAP)) is an important parameter in environmental fate assessments that consider spatial and temporal variability in environmental conditions. It has been shown that delta H(VAP)P for non-hydrogen-bonding substances can be estimated from vapor pressure at 298 K (P(L)) using an empirically derived linear relationship. Here, we demonstrate that the relationship between delta H(VAP)and PL is consistent with Trouton's rule and the ClausiusClapeyron equation under the assumption that delta H(VAP) is linearly dependent on temperature between 298 K and the boiling point temperature. Our interpretation based on Trouton's rule substantiates the empirical relationship between delta H(VAP) degree and P(L) degrees for non-hydrogen-bonding chemicals with subcooled liquid vapor pressures ranging over 15 orders of magnitude. We apply the relationship between delta H(VAP) degrees and P(L) degrees to evaluate data reported in literature reviews for several important classes of semivolatile environmental contaminants, including polycyclic aromatic hydrocarbons, chlorobenzenes, polychlorinated biphenyls and polychlorinated dibenzo-dioxins and -furans and illustrate the temperature dependence of results from a multimedia model presented as a partitioning map. The uncertainty associated with estimating delta H(VAP)degrees from P(L) degrees using this relationship is acceptable for most environmental fate modeling of non-hydrogen-bonding semivolatile organic chemicals.

  3. Neurodevelopmental effects of inhaled vapors of gasoline and ethanol in rats

    Science.gov (United States)

    Gasoline-ethanol blends comprise the major fraction of the fuel used in the US automotive fleet. To address uncertainties regarding the health risks associated with exposure to gasoline with more than 10% ethanol, we are assessing the effects of prenatal exposure to inhaled vapor...

  4. Soil tension mediates isotope fractionation during soil water evaporation

    Science.gov (United States)

    Gaj, Marcel; McDonnell, Jeffrey

    2017-04-01

    Isotope tracing of the water cycle is increasing in its use and usefulness. Many new studies are extracting soil waters and relating these to streamflow, groundwater recharge and plant transpiration. Nevertheless, unlike isotope fractionation factors from open water bodies, soil water fractionation factors are poorly understood and until now, only empirically derived. In contrast to open water evaporation where temperature, humidity and vapor pressure gradient define fractionation (as codified in the well-known Craig and Gordon model), soil water evaporation includes additionally, fractionation by matrix effects. There is yet no physical explanation of kinetic and equilibrium fraction from soil water within the soil profile. Here we present a simple laboratory experiment with four admixtures of soil grain size (from sand to silt to clay). Oven-dried samples were spiked with water of known isotopic composition at different soil water contents. Soils were then stored in sealed bags and the headspace filled with dry air and allowed to equilibrate for 24hours. Isotopic analysis of the headspace vapor was done with a Los Gatos Inc. water vapor isotope analyzer. Soil water potential of subsamples were measured with a water potential meter. We show for the first time that soil tension controls isotope fractionation in the resident soil water. Below a Pf 3.5 the δ-values of 18O and 2H of the headspace vapor is more positive and increases with increasing soil water potential. Surprisingly, we find that the relationship between soil tension and equilibrium fractionation is independent of soil type. However, δ-values of each soil type plot along a distinct evaporation line. These results indicate that equilibrium fractionation is affected by soil tension in addition to temperature. Therefore, at high soil water tension (under dry conditions) equilibrium fractionation is not consistent with current empirical formulations that ignore these effects. These findings may have

  5. Fractional distillation of oil

    Energy Technology Data Exchange (ETDEWEB)

    Jones, L D

    1931-10-31

    A method of dividing oil into lubricating oil fractions without substantial cracking by introducing the oil in a heated state into a fractionating column from which oil fractions having different boiling points are withdrawn at different levels, while reflux liquid is supplied to the top of the column, and additional heat is introduced into the column by contacting with the oil therein a heated fluid of higher monlecular weight than water and less susceptible to thermal decomposition than is the highest boiling oil fraction resulting from the distillation, or of which any products produced by thermal decomposition will not occur in the highest boiling distillate withdrawn from the column.

  6. Vapor deposition of tantalum and tantalum compounds

    International Nuclear Information System (INIS)

    Trkula, M.

    1996-01-01

    Tantalum, and many of its compounds, can be deposited as coatings with techniques ranging from pure, thermal chemical vapor deposition to pure physical vapor deposition. This review concentrates on chemical vapor deposition techniques. The paper takes a historical approach. The authors review classical, metal halide-based techniques and current techniques for tantalum chemical vapor deposition. The advantages and limitations of the techniques will be compared. The need for new lower temperature processes and hence new precursor chemicals will be examined and explained. In the last section, they add some speculation as to possible new, low-temperature precursors for tantalum chemical vapor deposition

  7. What Good is Raman Water Vapor Lidar?

    Science.gov (United States)

    Whitman, David

    2011-01-01

    Raman lidar has been used to quantify water vapor in the atmosphere for various scientific studies including mesoscale meteorology and satellite validation. Now the international networks of NDACC and GRUAN have interest in using Raman water vapor lidar for detecting trends in atmospheric water vapor concentrations. What are the data needs for addressing these very different measurement challenges. We will review briefly the scientific needs for water vapor accuracy for each of these three applications and attempt to translate that into performance specifications for Raman lidar in an effort to address the question in the title of "What good is Raman water vapor Iidar."

  8. High temperature vapors science and technology

    CERN Document Server

    Hastie, John

    2012-01-01

    High Temperature Vapors: Science and Technology focuses on the relationship of the basic science of high-temperature vapors to some areas of discernible practical importance in modern science and technology. The major high-temperature problem areas selected for discussion include chemical vapor transport and deposition; the vapor phase aspects of corrosion, combustion, and energy systems; and extraterrestrial high-temperature species. This book is comprised of seven chapters and begins with an introduction to the nature of the high-temperature vapor state, the scope and literature of high-temp

  9. The impact of vaporized nanoemulsions on ultrasound-mediated ablation.

    Science.gov (United States)

    Zhang, Peng; Kopechek, Jonathan A; Porter, Tyrone M

    2013-01-01

    . Broadband emissions detected during HIFU exposure coincided in time with measured accelerated heating, which suggested that IC played an important role in bubble-enhanced heating. In the presence of bubbles, the acoustic power required for the formation of a 9-mm(3) lesion was reduced by 72% and the exposure time required for the onset of albumin denaturation was significantly reduced (by 4 s), provided that the PSNE volume fraction in the polyacrylamide gel was at least 0.008%. The time or acoustic power required for lesion formation in gel phantoms was dramatically reduced by vaporizing PSNE into bubbles. These results suggest that PSNE may improve the efficiency of HIFU-mediated thermal ablation of solid tumors; thus, further investigation is warranted to determine whether bubble-enhanced HIFU may potentially become a viable option for cancer therapy.

  10. Geochemical and Petrologic Constraints on the Source of Eocene Volcanism at Mole Hill, Rockingham County, VA

    Science.gov (United States)

    Johnson, E. A.; Beard, J. S.

    2010-12-01

    Mole Hill is an Eocene (48 Ma) basaltic volcanic neck located west of Harrisonburg, VA, and provides a unique opportunity to probe the mantle beneath the Shenandoah Valley. It lies on the northeastern edge of a swarm of alkaline-series volcanic plugs, dikes, and diatremes extending through Rockingham and Highland Counties, VA, and Pendleton County, WV. The Eocene volcanics are thought to have exploited extensive basement fracture systems originally formed during the Alleghenian Orogeny and subsequent rifting. The Eocene volcanism may have been triggered by reactivation of faults due to global shifts in relative plate motions (Southworth 1993, USGS Bull, B1839-I) but the source material and magmatic processes for the Eocene volcanism are largely unknown. Compositional and texture analyses of xenocrystic and groundmass clinopyroxene, olivine, and spinel were completed either at Virginia Tech on the Cameca SX-50 electron microprobe in the Dept of Geological Sciences, or in the Dept of Mineral Sciences, Smithsonian Institution, Washington, D.C using the JEOL JXA-8900R WD/EDS microanalyzer or the FEI NOVA nanoSEM600 FEG Variable Pressure Scanning Electron Microscope. Xenocrysts up to 2cm in diameter are distributed throughout the volcanic neck, with clinopyroxene >>spinel>olivine. The clinopyroxene and olivine xenocrysts show undulatory extinction in cross-polarized light and are found as individual crystals or as aggregates. Clinopyroxene xenocryst cores are high-Al, low-Cr augite ( ˜Wo44En46Fs10) with Mg# 78.5-85.9. The clinopyroxene xenocrysts have compositionally zoned rims 100-250 μm-wide containing abundant plagioclase inclusions and sparse melt inclusions in a sieve texture. The outer edges of xenocrysts approach the compositions of groundmass and microphenocryst clinopyroxenes ( ˜Wo47En38Fs15; Mg# 67.9-74.5). Olivine xenocrysts contain sulfide inclusions and Cr-rich spinel and have Mg-rich ( ˜Fo86-90) cores with more Fe- and Ca-rich rims (Fo70

  11. Membrane phospholipid composition may contribute to exceptional longevity of the naked mole-rat (Heterocephalus glaber): a comparative study using shotgun lipidomics.

    Science.gov (United States)

    Mitchell, Todd W; Buffenstein, Rochelle; Hulbert, A J

    2007-11-01

    Phospholipids containing highly polyunsaturated fatty acids are particularly prone to peroxidation and membrane composition may therefore influence longevity. Phospholipid molecules, in particular those containing docosahexaenoic acid (DHA), from the skeletal muscle, heart, liver and liver mitochondria were identified and quantified using mass-spectrometry shotgun lipidomics in two similar-sized rodents that show an approximately 9-fold difference in maximum lifespan. The naked mole rat is the longest-living rodent known with a maximum lifespan of >28 years. Total phospholipid distribution is similar in tissues of both species; DHA is only found in phosphatidylcholines (PC), phosphatidylethanolamines (PE) and phosphatidylserines (PS), and DHA is relatively more concentrated in PE than PC. Naked mole-rats have fewer molecular species of both PC and PE than do mice. DHA-containing phospholipids represent 27-57% of all phospholipids in mice but only 2-6% in naked mole-rats. Furthermore, while mice have small amounts of di-polyunsaturated PC and PE, these are lacking in naked mole-rats. Vinyl ether-linked phospholipids (plasmalogens) are higher in naked mole-rat tissues than in mice. The lower level of DHA-containing phospholipids suggests a lower susceptibility to peroxidative damage in membranes of naked mole-rats compared to mice. Whereas the high level of plasmalogens might enhance membrane antioxidant protection in naked mole-rats compared to mice. Both characteristics possibly contribute to the exceptional longevity of naked mole-rats and may indicate a special role for peroxisomes in this extended longevity.

  12. Importance Profiles for Water Vapor

    Science.gov (United States)

    Mapes, Brian; Chandra, Arunchandra S.; Kuang, Zhiming; Zuidema, Paquita

    2017-11-01

    Motivated by the scientific desire to align observations with quantities of physical interest, we survey how scalar importance functions depend on vertically resolved water vapor. Definitions of importance begin from familiar examples of water mass I m and TOA clear-sky outgoing longwave flux I OLR, in order to establish notation and illustrate graphically how the sensitivity profile or "kernel" depends on whether specific humidity S, relative humidity R, or ln( R) are used as measures of vapor. Then, new results on the sensitivity of convective activity I con to vapor (with implied knock-on effects such as weather prediction skill) are presented. In radiative-convective equilibrium, organized (line-like) convection is much more sensitive to moisture than scattered isotropic convection, but it exists in a drier mean state. The lesson for natural convection may be that organized convection is less susceptible to dryness and can survive and propagate into regions unfavorable for disorganized convection. This counterintuitive interpretive conclusion, with respect to the narrow numerical result behind it, highlights the importance of clarity about what is held constant at what values in sensitivity or susceptibility kernels. Finally, the sensitivities of observable radiance signals I sig for passive remote sensing are considered. While the accuracy of R in the lower free troposphere is crucial for the physical importance scalars, this layer is unfortunately the most difficult to isolate with passive remote sensing: In high emissivity channels, water vapor signals come from too high in the atmosphere (for satellites) or too low (for surface radiometers), while low emissivity channels have poor altitude discrimination and (in the case of satellites) are contaminated by surface emissions. For these reasons, active ranging (LiDAR) is the preferred observing strategy.

  13. Vapor Pressure of Antimony Triiodide

    Science.gov (United States)

    2017-12-07

    unlimited. iii Contents List of Figures iv 1. Introduction 1 2. Vapor Pressure 1 3. Experiment 3 4. Discussion and Measurements 5 5...SbI3 as a function of temperature ......................... 6 Approved for public release; distribution is unlimited. 1 1. Introduction ...single-crystal thin films of n-type (Bi,Sb)2(Te,Se)3 materials presents new doping challenges because it is a nonequilibrium process. (Bi,Sb)2(Te,Se)3

  14. Sodium vapor charge exchange cell

    International Nuclear Information System (INIS)

    Hiddleston, H.R.; Fasolo, J.A.; Minette, D.C.; Chrien, R.E.; Frederick, J.A.

    1976-01-01

    An operational sequential charge-exchange ion source yielding a 50 MeV H - current of approximately 8 mA is planned for use with the Argonne 500 MeV booster synchrotron. We report on the progress for development of a sodium vapor charge-exchange cell as part of that planned effort. Design, fabrication, and operating results to date are presented and discussed. (author)

  15. Determination of Vaporization Properties and Volatile Hazardous Components Relevant to Kukersite Oil Shale Derived Fuel Oil Handling

    Directory of Open Access Journals (Sweden)

    Ada TRAUMANN

    2014-09-01

    Full Text Available The aim of this study was to investigate vaporization properties of shale fuel oil in relation to inhalation exposure. The shale fuel oil was obtained from kukersite oil shale. The shale oil and its light fraction (5 % of the total fuel oil were characterized by vapor pressure curve, molecular weight distribution, elemental composition and functional groups based on FTIR spectra. The rate of vaporization from the total fuel oil at different temperatures was monitored as a function of time using thermogravimetric analysis (TGA. It is shown that despite its relatively low vapor pressure at room temperature a remarkable amount of oil vaporizes influencing air quality significantly. From the TGA data the changes in the vapor pressure during vaporization process were estimated. Although the shale fuel oil has a strong, unpleasant smell, the main hazards to workplace air quality depend on the vaporization rate of different toxic compounds, such as benzene, toluene, xylene or phenolic compounds. The presence of these hazardous substances in the vapor phase of shale fuel oil was monitored using headspace analysis coupled with selective ion monitoring (SIM and confirmed by the NIST Mass Spectral library and retention times of standards. DOI: http://dx.doi.org/10.5755/j01.ms.20.3.4549

  16. Experimental Investigation of InSight HP3 Mole Interaction with Martian Regolith Simulant. Quasi-Static and Dynamic Penetration Testing

    Science.gov (United States)

    Marshall, Jason P.; Hudson, Troy L.; Andrade, José E.

    2017-10-01

    The InSight mission launches in 2018 to characterize several geophysical quantities on Mars, including the heat flow from the planetary interior. This quantity will be calculated by utilizing measurements of the thermal conductivity and the thermal gradient down to 5 meters below the Martian surface. One of the components of InSight is the Mole, which hammers into the Martian regolith to facilitate these thermal property measurements. In this paper, we experimentally investigated the effect of the Mole's penetrating action on regolith compaction and mechanical properties. Quasi-static and dynamic experiments were run with a 2D model of the 3D cylindrical mole. Force resistance data was captured with load cells. Deformation information was captured in images and analyzed using Digitial Image Correlation (DIC). Additionally, we used existing approximations of Martian regolith thermal conductivity to estimate the change in the surrounding granular material's thermal conductivity due to the Mole's penetration. We found that the Mole has the potential to cause a high degree of densification, especially if the initial granular material is relatively loose. The effect on the thermal conductivity from this densification was found to be relatively small in first-order calculations though more complete thermal models incorporating this densification should be a subject of further investigation. The results obtained provide an initial estimate of the Mole's impact on Martian regolith thermal properties.

  17. Naked mole-rat has increased translational fidelity compared with the mouse, as well as a unique 28S ribosomal RNA cleavage.

    Science.gov (United States)

    Azpurua, Jorge; Ke, Zhonghe; Chen, Iris X; Zhang, Quanwei; Ermolenko, Dmitri N; Zhang, Zhengdong D; Gorbunova, Vera; Seluanov, Andrei

    2013-10-22

    The naked mole-rat (Heterocephalus glaber) is a subterranean eusocial rodent with a markedly long lifespan and resistance to tumorigenesis. Multiple data implicate modulation of protein translation in longevity. Here we report that 28S ribosomal RNA (rRNA) of the naked mole-rat is processed into two smaller fragments of unequal size. The two breakpoints are located in the 28S rRNA divergent region 6 and excise a fragment of 263 nt. The excised fragment is unique to the naked mole-rat rRNA and does not show homology to other genomic regions. Because this hidden break site could alter ribosome structure, we investigated whether translation rate and amino acid incorporation fidelity were altered. We report that naked mole-rat fibroblasts have significantly increased translational fidelity despite having comparable translation rates with mouse fibroblasts. Although we cannot directly test whether the unique 28S rRNA structure contributes to the increased fidelity of translation, we speculate that it may change the folding or dynamics of the large ribosomal subunit, altering the rate of GTP hydrolysis and/or interaction of the large subunit with tRNA during accommodation, thus affecting the fidelity of protein synthesis. In summary, our results show that naked mole-rat cells produce fewer aberrant proteins, supporting the hypothesis that the more stable proteome of the naked mole-rat contributes to its longevity.

  18. Effect of the Ti/B4C mole ratio on the reaction products and reaction mechanism in an Al–Ti–B4C powder mixture

    International Nuclear Information System (INIS)

    Zhang, Jingjing; Lee, Jung-Moo; Cho, Young-Hee; Kim, Su-Hyeon; Yu, Huashun

    2014-01-01

    The effect of the Ti/B 4 C mole ratio on the fabrication behavior of Al composites is investigated using Al–Ti–B 4 C powder mixtures as reactants. The quick spontaneous infiltration (QSI) process combined with the combustion reaction and DTA analysis were used. According to the thermodynamic predictions, which are verified in the experimental results, TiB 2 is formed in all the samples whereas TiC is only formed in reactants with a Ti/B 4 C mole ratio of more than two. The C atoms from the reacted B 4 C do not move into TiC but instead they move into Al 3 BC or Al 4 C 3 when the Ti/B 4 C mole ratio is less than two. In addition, the reaction mechanism with a Ti/B 4 C mole ratio of 0.75 is investigated extensively. - Highlights: • The critical role of the Ti/B 4 C mole ratio on the reaction products of Al–Ti–B 4 C was studied using experiments. • The experimental results are also supported by thermodynamic calculations presented in this paper. • The reaction mechanism with a Ti/B 4 C mole ratio of 0.75 is investigated extensively

  19. An analytical solution to calculate bulk mole fractions for any number of components in aerosol droplets after considering partitioning to a surface layer

    Directory of Open Access Journals (Sweden)

    D. Topping

    2010-11-01

    Full Text Available Calculating the equilibrium composition of atmospheric aerosol particles, using all variations of Köhler theory, has largely assumed that the total solute concentrations define both the water activity and surface tension. Recently however, bulk to surface phase partitioning has been postulated as a process which significantly alters the predicted point of activation. In this paper, an analytical solution to calculate the removal of material from a bulk to a surface layer in aerosol particles has been derived using a well established and validated surface tension framework. The applicability to an unlimited number of components is possible via reliance on data from each binary system. Whilst assumptions regarding behaviour at the surface layer have been made to facilitate derivation, it is proposed that the framework presented can capture the overall impact of bulk-surface partitioning. Demonstrations of the equations for two and five component mixtures are given while comparisons are made with more detailed frameworks capable at modelling ternary systems at higher levels of complexity. Predictions made by the model across a range of surface active properties should be tested against measurements. Indeed, reccomendations are given for experimental validation and to assess sensitivities to accuracy and required level of complexity within large scale frameworks. Importantly, the computational efficiency of using the solution presented in this paper is roughly a factor of 20 less than a similar iterative approach, a comparison with highly coupled approaches not available beyond a 3 component system.

  20. Equation of state modeling of the phase equilibria of asymmetric CO2+n-alkane binary systems using mixing rules cubic with respect to mole fraction

    DEFF Research Database (Denmark)

    Cismondi, Martin; Mollerup, Jørgen M.; Zabaloy, Marcelo S.

    2010-01-01

    for a great diversity of mixtures. Nevertheless, the models for representing phase equilibria and physico-chemical properties of asymmetric systems may require more flexible mixing rules than the classical quadratic van der Waals (vdW) mixing rules or their equivalent (with regard to the number of available...... interaction parameters) in modern equations of state.In particular, the phase equilibria of binary mixtures containing CO2 and heavy n-alkanes have been studied by an important number of authors and using different types of models, achieving only partially accurate results and realizing the difficulties...

  1. Fractional Poisson process (II)

    International Nuclear Information System (INIS)

    Wang Xiaotian; Wen Zhixiong; Zhang Shiying

    2006-01-01

    In this paper, we propose a stochastic process W H (t)(H-bar (12,1)) which we call fractional Poisson process. The process W H (t) is self-similar in wide sense, displays long range dependence, and has more fatter tail than Gaussian process. In addition, it converges to fractional Brownian motion in distribution

  2. An Appetite for Fractions

    Science.gov (United States)

    Wilkerson, Trena L.; Bryan, Tommy; Curry, Jane

    2012-01-01

    This article describes how using candy bars as models gives sixth-grade students a taste for learning to represent fractions whose denominators are factors of twelve. Using paper models of the candy bars, students explored and compared fractions. They noticed fewer different representations for one-third than for one-half. The authors conclude…

  3. Can Kindergartners Do Fractions?

    Science.gov (United States)

    Cwikla, Julie

    2014-01-01

    Mathematics professor Julie Cwikla decided that she needed to investigate young children's understandings and see what precurricular partitioning notions young minds bring to the fraction table. Cwikla realized that only a handful of studies have examined how preschool-age and early elementary school-age students solve fraction problems (Empson…

  4. Water vapor changes under global warming and the linkage to present-day interannual variabilities in CMIP5 models

    Science.gov (United States)

    Takahashi, Hanii; Su, Hui; Jiang, Jonathan H.

    2016-12-01

    The fractional water vapor changes under global warming across 14 Coupled Model Intercomparison Project Phase 5 simulations are analyzed. We show that the mean fractional water vapor changes under global warming in the tropical upper troposphere between 300 and 100 hPa range from 12.4 to 28.0 %/K across all models while the fractional water vapor changes are about 5-8 %/K in other regions and at lower altitudes. The "upper-tropospheric amplification" of the water vapor change is primarily driven by a larger temperature increase in the upper troposphere than in the lower troposphere per degree of surface warming. The relative contributions of atmospheric temperature and relative humidity changes to the water vapor change in each model vary between 71.5 to 131.8 % and 24.8 to -20.1 %, respectively. The inter-model differences in the water vapor change is primarily caused by differences in temperature change, except over the inter-tropical convergence zone within 10°S-10°N where the model differences due to the relative humidity change are significant. Furthermore, we find that there is generally a positive correlation between the rates of water vapor change for long-tem surface warming and those on the interannual time scales. However, the rates of water vapor change under long-term warming have a systematic offset from those on the inter-annual time scales and the dominant contributor to the differences also differs for the two time scales, suggesting caution needs to be taken when inferring long-term water vapor changes from the observed interannual variations.

  5. Fractional bosonic strings

    Science.gov (United States)

    Diaz, Victor Alfonzo; Giusti, Andrea

    2018-03-01

    The aim of this paper is to present a simple generalization of bosonic string theory in the framework of the theory of fractional variational problems. Specifically, we present a fractional extension of the Polyakov action, for which we compute the general form of the equations of motion and discuss the connection between the new fractional action and a generalization the Nambu-Goto action. Consequently, we analyze the symmetries of the modified Polyakov action and try to fix the gauge, following the classical procedures. Then we solve the equations of motion in a simplified setting. Finally, we present a Hamiltonian description of the classical fractional bosonic string and introduce the fractional light-cone gauge. It is important to remark that, throughout the whole paper, we thoroughly discuss how to recover the known results as an "integer" limit of the presented model.

  6. Atmospheric sugar alcohols: evaporation rates and saturation vapor pressures

    DEFF Research Database (Denmark)

    Bilde, Merete; Zardini, Alessandro Alessio; Hong, Juan

    alcohols. These polyols are common in the water soluble fraction of atmospheric aerosols. In our experimental system sub-micron particles are generated by nebulization from aqueous solution, and a mono disperse fraction of the aerosol is selected using a differential mobility analyzer. The particles......The atmospheric partitioning between gas and condensed phase of organic molecules is poorly understood, and discrepancies exist between predicted and observed concentrations of secondary organic aerosols. A key problem is the lack of information about thermodynamic properties of semi- and low...... volatile organic molecules. Saturation vapor pressure and the associated temperature dependence (dH) are key parameters for improving predictive atmospheric models. In this work we combine experiments and thermodynamic modeling to investigate these parameters for a series of polyols, so-called sugar...

  7. Unusual ratio between free thyroxine and free triiodothyronine in a long-lived mole-rat species with bimodal ageing.

    Science.gov (United States)

    Henning, Yoshiyuki; Vole, Christiane; Begall, Sabine; Bens, Martin; Broecker-Preuss, Martina; Sahm, Arne; Szafranski, Karol; Burda, Hynek; Dammann, Philip

    2014-01-01

    Ansell's mole-rats (Fukomys anselli) are subterranean, long-lived rodents, which live in eusocial families, where the maximum lifespan of breeders is twice as long as that of non-breeders. Their metabolic rate is significantly lower than expected based on allometry, and their retinae show a high density of S-cone opsins. Both features may indicate naturally low thyroid hormone levels. In the present study, we sequenced several major components of the thyroid hormone pathways and analyzed free and total thyroxine and triiodothyronine in serum samples of breeding and non-breeding F. anselli to examine whether a) their thyroid hormone system shows any peculiarities on the genetic level, b) these animals have lower hormone levels compared to euthyroid rodents (rats and guinea pigs), and c) reproductive status, lifespan and free hormone levels are correlated. Genetic analyses confirmed that Ansell's mole-rats have a conserved thyroid hormone system as known from other mammalian species. Interspecific comparisons revealed that free thyroxine levels of F. anselli were about ten times lower than of guinea pigs and rats, whereas the free triiodothyronine levels, the main biologically active form, did not differ significantly amongst species. The resulting fT4:fT3 ratio is unusual for a mammal and potentially represents a case of natural hypothyroxinemia. Comparisons with total thyroxine levels suggest that mole-rats seem to possess two distinct mechanisms that work hand in hand to downregulate fT4 levels reliably. We could not find any correlation between free hormone levels and reproductive status, gender or weight. Free thyroxine may slightly increase with age, based on sub-significant evidence. Hence, thyroid hormones do not seem to explain the different ageing rates of breeders and non-breeders. Further research is required to investigate the regulatory mechanisms responsible for the unusual proportion of free thyroxine and free triiodothyronine.

  8. Unusual ratio between free thyroxine and free triiodothyronine in a long-lived mole-rat species with bimodal ageing.

    Directory of Open Access Journals (Sweden)

    Yoshiyuki Henning

    Full Text Available Ansell's mole-rats (Fukomys anselli are subterranean, long-lived rodents, which live in eusocial families, where the maximum lifespan of breeders is twice as long as that of non-breeders. Their metabolic rate is significantly lower than expected based on allometry, and their retinae show a high density of S-cone opsins. Both features may indicate naturally low thyroid hormone levels. In the present study, we sequenced several major components of the thyroid hormone pathways and analyzed free and total thyroxine and triiodothyronine in serum samples of breeding and non-breeding F. anselli to examine whether a their thyroid hormone system shows any peculiarities on the genetic level, b these animals have lower hormone levels compared to euthyroid rodents (rats and guinea pigs, and c reproductive status, lifespan and free hormone levels are correlated. Genetic analyses confirmed that Ansell's mole-rats have a conserved thyroid hormone system as known from other mammalian species. Interspecific comparisons revealed that free thyroxine levels of F. anselli were about ten times lower than of guinea pigs and rats, whereas the free triiodothyronine levels, the main biologically active form, did not differ significantly amongst species. The resulting fT4:fT3 ratio is unusual for a mammal and potentially represents a case of natural hypothyroxinemia. Comparisons with total thyroxine levels suggest that mole-rats seem to possess two distinct mechanisms that work hand in hand to downregulate fT4 levels reliably. We could not find any correlation between free hormone levels and reproductive status, gender or weight. Free thyroxine may slightly increase with age, based on sub-significant evidence. Hence, thyroid hormones do not seem to explain the different ageing rates of breeders and non-breeders. Further research is required to investigate the regulatory mechanisms responsible for the unusual proportion of free thyroxine and free triiodothyronine.

  9. Social status and sex independently influence androgen receptor expression in the eusocial naked mole-rat brain.

    Science.gov (United States)

    Holmes, Melissa M; Goldman, Bruce D; Forger, Nancy G

    2008-08-01

    Naked mole-rats (Heterocephalus glaber) are eusocial rodents that live in large subterranean colonies including a single breeding female and 1-3 breeding males; all other members of the colony, known as subordinates, are reproductively suppressed. We recently found that naked mole-rats lack many of the sex differences in the brain and spinal cord commonly found in other rodents. Instead, neural morphology is influenced by breeding status, such that breeders, regardless of sex, have more neurons than subordinates in the ventromedial nucleus of the hypothalamus (VMH), and larger overall volumes of the bed nucleus of the stria terminalis (BST), paraventricular nucleus (PVN) and medial amygdala (MeA). To begin to understand how breeding status influences brain morphology, we examined the distribution of androgen receptor (AR) immunoreactivity in gonadally intact breeders and subordinates of both sexes. All animals had AR+ nuclei in many of the same regions positive for AR in other mammals, including the VMH, BST, PVN, MeA, and the ventral portion of the premammillary nucleus (PMv). We also observed diffuse labeling throughout the preoptic area, demonstrating that distribution of the AR protein in presumptive reproductive brain nuclei is well-conserved, even in a species that exhibits remarkably little sexual dimorphism. In contrast to other rodents, however, naked mole-rats lacked AR+ nuclei in the suprachiasmatic nucleus and hippocampus. Males had more AR+ nuclei in the MeA, VMH, and PMv than did females. Surprisingly, breeders had significantly fewer AR+ nuclei than subordinates in all brain regions examined (VMH, BST, PVN, MeA, and PMv). Thus, social status is strongly correlated with AR immunoreactivity in this eusocial species.

  10. Postprandial heat increment does not substitute for active thermogenesis in cold-challenged star-nosed moles (Condylura cristata).

    Science.gov (United States)

    Campbell, K L; McIntyre, I W; MacArthur, R A

    2000-01-01

    The postprandial increase in metabolic rate associated with consuming, assimilating and excreting a meal is often termed the heat increment of feeding (HIF). The metabolic heat production of star-nosed moles, Condylura cristata, held at thermoneutrality was monitored for 4 h following a single 10 min session of feeding on a ration consisting of 0 g (controls), 3.5 g or 10 g of earthworms. Coefficients for metabolizable energy digestibility and digesta passage rate of earthworms fed to C. cristata were also determined. We then tested whether feeding-induced thermogenesis substitutes partially or completely for thermoregulatory heat production in these animals exposed to sub-thermoneutral air temperatures (9-24 degrees C). A single feeding on earthworms had both short- and long-term effects on the metabolic rate and respiratory exchange ratio of C. cristata. The observed short-term (0-65 min) rise in metabolic rate, assumed to be associated primarily with the physical costs of nutrient digestion, absorption and excretion, was similar to the calculated mean retention time (66.7+/-7.8 min; mean +/- s.e. m., N=5) of this species. This component of the HIF represented 2.9 % of the food energy ingested by moles fed a single 3.5 g (13.21 kJ) meal of earthworms and 1.4 % of the food energy ingested by moles fed a single 7.5 g (28.09 kJ) meal of earthworms. At all test temperatures, resting metabolic rate typically remained above fasting levels for 1-4 h following ingestion of the high-protein earthworm diet. This protracted rise in metabolic rate, presumably associated with the biochemical costs of amino acid oxidation/gluconeogenesis and ureagenesis, averaged 12.8 % of the metabolizable energy and 8.7 % of the gross energy intake. Despite the potential thermoregulatory benefit, we found no evidence that biochemical HIF substitutes for facultative thermogenesis in star-nosed moles exposed to low air temperatures.

  11. Fractional Order Generalized Information

    Directory of Open Access Journals (Sweden)

    José Tenreiro Machado

    2014-04-01

    Full Text Available This paper formulates a novel expression for entropy inspired in the properties of Fractional Calculus. The characteristics of the generalized fractional entropy are tested both in standard probability distributions and real world data series. The results reveal that tuning the fractional order allow an high sensitivity to the signal evolution, which is useful in describing the dynamics of complex systems. The concepts are also extended to relative distances and tested with several sets of data, confirming the goodness of the generalization.

  12. Fractional finite Fourier transform.

    Science.gov (United States)

    Khare, Kedar; George, Nicholas

    2004-07-01

    We show that a fractional version of the finite Fourier transform may be defined by using prolate spheroidal wave functions of order zero. The transform is linear and additive in its index and asymptotically goes over to Namias's definition of the fractional Fourier transform. As a special case of this definition, it is shown that the finite Fourier transform may be inverted by using information over a finite range of frequencies in Fourier space, the inversion being sensitive to noise. Numerical illustrations for both forward (fractional) and inverse finite transforms are provided.

  13. Social Trust and Fractionalization:

    DEFF Research Database (Denmark)

    Bjørnskov, Christian

    2008-01-01

    This paper takes a closer look at the importance of fractionalization for the creation of social trust. It first argues that the determinants of trust can be divided into two categories: those affecting individuals' trust radii and those affecting social polarization. A series of estimates using...... a much larger country sample than in previous literature confirms that fractionalization in the form of income inequality and political diversity adversely affects social trust while ethnic diversity does not. However, these effects differ systematically across countries, questioning standard...... interpretations of the influence of fractionalization on trust....

  14. Microwave assisted chemical vapor infiltration

    International Nuclear Information System (INIS)

    Devlin, D.J.; Currier, R.P.; Barbero, R.S.; Espinoza, B.F.; Elliott, N.

    1991-01-01

    A microwave assisted process for production of continuous fiber reinforced ceramic matrix composites is described. A simple apparatus combining a chemical vapor infiltration reactor with a conventional 700 W multimode oven is described. Microwave induced inverted thermal gradients are exploited with the ultimate goal of reducing processing times on complex shapes. Thermal gradients in stacks of SiC (Nicalon) cloths have been measured using optical thermometry. Initial results on the ''inside out'' deposition of SiC via decomposition of methyltrichlorosilane in hydrogen are presented. Several key processing issues are identified and discussed. 5 refs

  15. Overview of chemical vapor infiltration

    Energy Technology Data Exchange (ETDEWEB)

    Besmann, T.M.; Stinton, D.P.; Lowden, R.A.

    1993-06-01

    Chemical vapor infiltration (CVI) is developing into a commercially important method for the fabrication of continuous filament ceramic composites. Current efforts are focused on the development of an improved understanding of the various processes in CVI and its modeling. New approaches to CVI are being explored, including pressure pulse infiltration and microwave heating. Material development is also proceeding with emphasis on improving the oxidation resistance of the interfacial layer between the fiber and matrix. This paper briefly reviews these subjects, indicating the current state of the science and technology.

  16. A Lithium Vapor Box Divertor Similarity Experiment

    Science.gov (United States)

    Cohen, Robert A.; Emdee, Eric D.; Goldston, Robert J.; Jaworski, Michael A.; Schwartz, Jacob A.

    2017-10-01

    A lithium vapor box divertor offers an alternate means of managing the extreme power density of divertor plasmas by leveraging gaseous lithium to volumetrically extract power. The vapor box divertor is a baffled slot with liquid lithium coated walls held at temperatures which increase toward the divertor floor. The resulting vapor pressure differential drives gaseous lithium from hotter chambers into cooler ones, where the lithium condenses and returns. A similarity experiment was devised to investigate the advantages offered by a vapor box divertor design. We discuss the design, construction, and early findings of the vapor box divertor experiment including vapor can construction, power transfer calculations, joint integrity tests, and thermocouple data logging. Heat redistribution of an incident plasma-based heat flux from a typical linear plasma device is also presented. This work supported by DOE Contract No. DE-AC02-09CH11466 and The Princeton Environmental Institute.

  17. Thermogravimetric measurements of liquid vapor pressure

    International Nuclear Information System (INIS)

    Rong Yunhong; Gregson, Christopher M.; Parker, Alan

    2012-01-01

    Highlights: ► Rapid determination of vapor pressure by TGA. ► Demonstration of limitations of currently available approaches in literature. ► New model for vapor pressure assessment of small size samples in TGA. ► New model accounts for vapor diffusion and sample geometry and measures vapor pressure normally within 10%. - Abstract: A method was developed using thermo-gravimetric analysis (TGA) to determine the vapor pressure of volatile liquids. This is achieved by measuring the rate of evaporation (mass loss) of a pure liquid contained within a cylindrical pan. The influence of factors like sample geometry and vapor diffusion on evaporation rate are discussed. The measurement can be performed across a wide range of temperature yielding reasonable results up to 10 kPa. This approach may be useful as a rapid and automatable method for measuring the volatility of flavor and fragrance raw materials.

  18. Evaporation Induced Oxygen Isotope Fractionation in Impact Ejecta

    Science.gov (United States)

    Macris, C. A.; Young, E. D.; Kohl, I. E.; zur Loye, T. E.

    2017-12-01

    Tektites are natural glasses formed as quenched impact melt ejecta. Because they experienced extreme heating while entrained in a hot impact vapor plume, tektites allow insight into the nature of these ephemeral events, which play a critical role in planetary accretion and evolution. During tektite formation, the chemical and isotopic composition of parent materials may be modified by (1) vapor/liquid fractionation at high T in the plume, (2) incorporation of meteoric water at the target site, (3) isotope exchange with atmospheric oxygen (if present), or some combination of the three. Trends from O isotope studies reveal a dichotomy: some tektite δ18O values are 4.0-4.5‰ lower than their protoliths (Luft et al. 1987; Taylor & Epstein 1962), opposite in direction to a vaporization induced fractionation; increases in δ18O with decreasing SiO2 in tektites (Taylor & Epstein 1969) is consistent with vapor fractionation. Using an aerodynamic levitation laser furnace (e.g. Macris et al. 2016), we can experimentally determine the contributions of processes (1), (2) and (3) above to tektite compositions. We conducted a series of evaporation experiments to test process (1) using powdered tektite fused into 2 mm spheres and heated to 2423-2473 K for 50-90 s while levitated in Ar in the furnace. Mass losses were from 23 to 26%, reflecting evaporation of Si and O from the melt. The starting tektite had a δ18O value of 10.06‰ (±0.01 2se) and the residues ranged from 13.136‰ (±0.006) for the least evaporated residue to 14.30‰ (±0.02) for the most evaporated (measured by laser fluorination). The increase in δ18O with increasing mass loss is consistent with Rayleigh fractionation during evaporation, supporting the idea that O isotopes are fractionated due to vaporization at high T in an impact plume. Because atmospheric O2 and water each have distinctive Δ17O values, we should be able to use departures from our measured three-isotope fractionation law to evaluate

  19. FRACTIONS: CONCEPTUAL AND DIDACTIC ASPECTS

    Directory of Open Access Journals (Sweden)

    Sead Rešić

    2016-09-01

    Full Text Available Fractions represent the manner of writing parts of whole numbers (integers. Rules for operations with fractions differ from rules for operations with integers. Students face difficulties in understanding fractions, especially operations with fractions. These difficulties are well known in didactics of Mathematics throughout the world and there is a lot of research regarding problems in learning about fractions. Methods for facilitating understanding fractions have been discovered, which are essentially related to visualizing operations with fractions.

  20. Fractional Stochastic Field Theory

    Science.gov (United States)

    Honkonen, Juha

    2018-02-01

    Models describing evolution of physical, chemical, biological, social and financial processes are often formulated as differential equations with the understanding that they are large-scale equations for averages of quantities describing intrinsically random processes. Explicit account of randomness may lead to significant changes in the asymptotic behaviour (anomalous scaling) in such models especially in low spatial dimensions, which in many cases may be captured with the use of the renormalization group. Anomalous scaling and memory effects may also be introduced with the use of fractional derivatives and fractional noise. Construction of renormalized stochastic field theory with fractional derivatives and fractional noise in the underlying stochastic differential equations and master equations and the interplay between fluctuation-induced and built-in anomalous scaling behaviour is reviewed and discussed.

  1. Discrete fractional calculus

    CERN Document Server

    Goodrich, Christopher

    2015-01-01

    This text provides the first comprehensive treatment of the discrete fractional calculus. Experienced researchers will find the text useful as a reference for discrete fractional calculus and topics of current interest. Students who are interested in learning about discrete fractional calculus will find this text to provide a useful starting point. Several exercises are offered at the end of each chapter and select answers have been provided at the end of the book. The presentation of the content is designed to give ample flexibility for potential use in a myriad of courses and for independent study. The novel approach taken by the authors includes a simultaneous treatment of the fractional- and integer-order difference calculus (on a variety of time scales, including both the usual forward and backwards difference operators). The reader will acquire a solid foundation in the classical topics of the discrete calculus while being introduced to exciting recent developments, bringing them to the frontiers of the...

  2. Fractional smith chart theory

    KAUST Repository

    Shamim, Atif; Radwan, Ahmed Gomaa; Salama, Khaled N.

    2011-01-01

    matching networks, where the fractional approach proves to be much more versatile and results in a single element matching network for a complex load as compared to the two elements in the conventional approach. © 2010 IEEE.

  3. Ion vapor deposition and its application

    International Nuclear Information System (INIS)

    Bollinger, H.; Schulze, D.; Wilberg, R.

    1981-01-01

    Proceeding from the fundamentals of ion vapor deposition the characteristic properties of ion-plated coatings are briefly discussed. Examples are presented of successful applications of ion-plated coatings such as coatings with special electrical and dielectric properties, coatings for corrosion prevention, and coatings for improving the surface properties. It is concluded that ion vapor deposition is an advantageous procedure in addition to vapor deposition. (author)

  4. Intracellular Cadmium Isotope Fractionation

    Science.gov (United States)

    Horner, T. J.; Lee, R. B.; Henderson, G. M.; Rickaby, R. E.

    2011-12-01

    Recent stable isotope studies into the biological utilization of transition metals (e.g. Cu, Fe, Zn, Cd) suggest several stepwise cellular processes can fractionate isotopes in both culture and nature. However, the determination of fractionation factors is often unsatisfactory, as significant variability can exist - even between different organisms with the same cellular functions. Thus, it has not been possible to adequately understand the source and mechanisms of metal isotopic fractionation. In order to address this problem, we investigated the biological fractionation of Cd isotopes within genetically-modified bacteria (E. coli). There is currently only one known biological use or requirement of Cd, a Cd/Zn carbonic anhydrase (CdCA, from the marine diatom T. weissfloggii), which we introduce into the E. coli genome. We have also developed a cleaning procedure that allows for the treating of bacteria so as to study the isotopic composition of different cellular components. We find that whole cells always exhibit a preference for uptake of the lighter isotopes of Cd. Notably, whole cells appear to have a similar Cd isotopic composition regardless of the expression of CdCA within the E. coli. However, isotopic fractionation can occur within the genetically modified E. coli during Cd use, such that Cd bound in CdCA can display a distinct isotopic composition compared to the cell as a whole. Thus, the externally observed fractionation is independent of the internal uses of Cd, with the largest Cd isotope fractionation occurring during cross-membrane transport. A general implication of these experiments is that trace metal isotopic fractionation most likely reflects metal transport into biological cells (either actively or passively), rather than relating to expression of specific physiological function and genetic expression of different metalloenzymes.

  5. Water Vapor on Titan: The Stratospheric Vertical Profile from Cassini/CIRS Infrared Spectra

    Science.gov (United States)

    Cottini, V.; Jennings, D. E.; Nixon, C. A.; Anderson, C. M.; Gorius, N.; Bjoraker, G. L.; Coustenis, A.; Achterberg, R. K.; Teanby, N. A.; deKok, R.; hide

    2012-01-01

    Water vapor in Titan's middle atmosphere has previously been detected only by disk-average observations from the Infrared Space Observatory (Coustenis et al., 1998). We report here the successful detection of stratospheric water vapor using the Cassini Composite Infrared Spectrometer (CIRS, Flasar et al., 2004) following an earlier null result (de Kok et al., 2007a). CIRS senses water emissions in the far-infrared spectral region near 50 microns, which we have modeled using two independent radiative transfer and inversion codes (NEMESIS, Irwin et al 2008 and ART, Coustenis et al., 2010). From the analysis of nadir spectra we have derived a mixing ratio of (0.14 plus or minus 0.05) ppb at 100 km, corresponding to a column abundance of approximately (3.7 plus or minus 1.3) x 10(exp 14) moles per square centimeter. Using limb observations, we obtained mixing ratios of (0.13 plus or minus 0.04) ppb at 125 km and (0.45 plus or minus 0.15) ppb at 225 km of altitude, confirming that the water abundance has a positive vertical gradient as predicted by photochemical models. In the latitude range (80 deg. S - 30 deg. N) we see no evidence for latitudinal variations in these abundances within the error bars.

  6. Transcriptome sequencing of the blind subterranean mole rat, Spalax galili: Utility and potential for the discovery of novel evolutionary patterns

    KAUST Repository

    Malik, Assaf

    2011-08-12

    The blind subterranean mole rat (Spalax ehrenbergi superspecies) is a model animal for survival under extreme environments due to its ability to live in underground habitats under severe hypoxic stress and darkness. Here we report the transcriptome sequencing of Spalax galili, a chromosomal type of S. ehrenbergi. cDNA pools from muscle and brain tissues isolated from animals exposed to hypoxic and normoxic conditions were sequenced using Sanger, GS FLX, and GS FLX Titanium technologies. Assembly of the sequences yielded over 51,000 isotigs with homology to ~12,000 mouse, rat or human genes. Based on these results, it was possible to detect large numbers of splice variants, SNPs, and novel transcribed regions. In addition, multiple differential expression patterns were detected between tissues and treatments. The results presented here will serve as a valuable resource for future studies aimed at identifying genes and gene regions evolved during the adaptive radiation associated with underground life of the blind mole rat. 2011 Malik et al.

  7. Exceptional Chromosomal Evolution and Cryptic Speciation of Blind Mole Rats Nannospalax leucodon (Spalacinae, Rodentia from South-Eastern Europe

    Directory of Open Access Journals (Sweden)

    Ivo Savić

    2017-10-01

    Full Text Available Mole rats are exclusively subterranean and highly specialized rodents. Their long lifespans, remarkable anti-cancer mechanisms, and various distinctive adaptive features make them a useful research model. Moreover, opposing convergence of morphological traits, they have developed extremely high karyotype variability. Thus, 74 chromosomal forms have been described so far and new ones are being revealed continuously. These evolved during the process of rapid radiation and occur in different biogeographical regions. During research into their reproductive biology we have already provided substantial evidence for species-level separation of these taxa. Here, we review diverse chromosomal forms of the lesser blind mole rat, Mediterranean Nannospalax leucodon, distributed in South-eastern Europe, their karyotype records, biogeography, origin, and phylogeny from our extensive research. In the light of new data from molecular genetic studies, we question some former valuations and propose a cryptospecies rank for seven reproductively isolated chromosomal forms with sympatric and parapatric distribution and clear ecogeographical discrepances in their habitats, as well as new experimental and theoretical methods for understanding the courses of speciation of these unique fossorial mammals.

  8. Environmental physiology of the mole crab Emerita asiatica, at a power plant discharge area on the east coast of India

    International Nuclear Information System (INIS)

    Suresh, K.; Ahamed, M.S.; Durairaj, G.; Nair, K.V.K.

    1995-01-01

    Cage experiments at the discharge area of Madras Atomic Power Station (MAPS) facilitated studies of thermal tolerance in Emerita asiatica. At the laboratory, oxygen consumption at various temperatures and varying salinities was also investigated. In the field 100% mortality of crabs was recorded at the Condenser Cooling Water Pumps (CCWP) discharge site compared to no mortality at the Processed Sea Water Pumps (PSWP) site. This observation implicated temperature as a stress factor at the CCWP outfall, because other factors, including residual chlorine and water velocity, were the same at the PSWP and CCWP sites. Laboratory experiments on tolerance revealed that 38.5 o C was lethal to mole crabs. The time taken for 100% mortality decreased as the temperature increased from 35 to 40 o C. Oxygen metabolism showed a progressive increase with temperature from 29 to 36 o c, and declined at 37 o C. The influence of salinity on oxygen consumption was marginal at salinities of 20 to 35o/oo but, when reduced to 15o/oo, the oxygen consumption declined. The present study thus indicates that temperature could be the lethal factor, determining the distribution of mole crabs near the power station, where water temperature can exceed 40 o C. (author)

  9. The anti-tumorigenic activity of A2M-A lesson from the naked mole-rat.

    Directory of Open Access Journals (Sweden)

    Susanne Kurz

    Full Text Available Cancer resistance is a major cause for longevity of the naked mole-rat. Recent liver transcriptome analysis in this animal compared to wild-derived mice revealed higher expression of alpha2-macroglobulin (A2M and cell adhesion molecules, which contribute to the naked mole-rat's cancer resistance. Notably, A2M is known to dramatically decrease with age in humans. We hypothesize that this might facilitate tumour development. Here we found that A2M modulates tumour cell adhesion, migration and growth by inhibition of tumour promoting signalling pathways, e.g. PI3K / AKT, SMAD and up-regulated PTEN via down-regulation of miR-21, in vitro and in tumour xenografts. A2M increases the expression of CD29 and CD44 but did not evoke EMT. Transcriptome analysis of A2M-treated tumour cells, xenografts and mouse liver demonstrated a multifaceted regulation of tumour promoting signalling pathways indicating a less tumorigenic environment mediated by A2M. By virtue of these multiple actions the naturally occurring A2M has strong potential as a novel therapeutic agent.

  10. The anti-tumorigenic activity of A2M-A lesson from the naked mole-rat.

    Science.gov (United States)

    Kurz, Susanne; Thieme, René; Amberg, Ronny; Groth, Marco; Jahnke, Heinz-Georg; Pieroh, Philipp; Horn, Lars-Christian; Kolb, Marlen; Huse, Klaus; Platzer, Matthias; Volke, Daniela; Dehghani, Faramarz; Buzdin, Anton; Engel, Kathrin; Robitzki, Andrea; Hoffmann, Ralf; Gockel, Ines; Birkenmeier, Gerd

    2017-01-01

    Cancer resistance is a major cause for longevity of the naked mole-rat. Recent liver transcriptome analysis in this animal compared to wild-derived mice revealed higher expression of alpha2-macroglobulin (A2M) and cell adhesion molecules, which contribute to the naked mole-rat's cancer resistance. Notably, A2M is known to dramatically decrease with age in humans. We hypothesize that this might facilitate tumour development. Here we found that A2M modulates tumour cell adhesion, migration and growth by inhibition of tumour promoting signalling pathways, e.g. PI3K / AKT, SMAD and up-regulated PTEN via down-regulation of miR-21, in vitro and in tumour xenografts. A2M increases the expression of CD29 and CD44 but did not evoke EMT. Transcriptome analysis of A2M-treated tumour cells, xenografts and mouse liver demonstrated a multifaceted regulation of tumour promoting signalling pathways indicating a less tumorigenic environment mediated by A2M. By virtue of these multiple actions the naturally occurring A2M has strong potential as a novel therapeutic agent.

  11. Negligible senescence in the longest living rodent, the naked mole-rat: insights from a successfully aging species.

    Science.gov (United States)

    Buffenstein, Rochelle

    2008-05-01

    Aging refers to a gradual deterioration in function that, over time, leads to increased mortality risk, and declining fertility. This pervasive process occurs in almost all organisms, although some long-lived trees and cold water inhabitants reportedly show insignificant aging. Negligible senescence is characterized by attenuated age-related change in reproductive and physiological functions, as well as no observable age-related gradual increase in mortality rate. It was questioned whether the longest living rodent, the naked mole-rat, met these three strict criteria. Naked mole-rats live in captivity for more than 28.3 years, approximately 9 times longer than similar-sized mice. They maintain body composition from 2 to 24 years, and show only slight age-related changes in all physiological and morphological characteristics studied to date. Surprisingly breeding females show no decline in fertility even when well into their third decade of life. Moreover, these animals have never been observed to develop any spontaneous neoplasm. As such they do not show the typical age-associated acceleration in mortality risk that characterizes every other known mammalian species and may therefore be the first reported mammal showing negligible senescence over the majority of their long lifespan. Clearly physiological and biochemical processes in this species have evolved to dramatically extend healthy lifespan. The challenge that lies ahead is to understand what these mechanisms are.

  12. Walking the oxidative stress tightrope: a perspective from the naked mole-rat, the longest-living rodent.

    Science.gov (United States)

    Rodriguez, Karl A; Wywial, Ewa; Perez, Viviana I; Lambert, Adriant J; Edrey, Yael H; Lewis, Kaitlyn N; Grimes, Kelly; Lindsey, Merry L; Brand, Martin D; Buffenstein, Rochelle

    2011-01-01

    Reactive oxygen species (ROS), by-products of aerobic metabolism, cause oxidative damage to cells and tissue and not surprisingly many theories have arisen to link ROS-induced oxidative stress to aging and health. While studies clearly link ROS to a plethora of divergent diseases, their role in aging is still debatable. Genetic knock-down manipulations of antioxidants alter the levels of accrued oxidative damage, however, the resultant effect of increased oxidative stress on lifespan are equivocal. Similarly the impact of elevating antioxidant levels through transgenic manipulations yield inconsistent effects on longevity. Furthermore, comparative data from a wide range of endotherms with disparate longevity remain inconclusive. Many long-living species such as birds, bats and mole-rats exhibit high-levels of oxidative damage, evident already at young ages. Clearly, neither the amount of ROS per se nor the sensitivity in neutralizing ROS are as important as whether or not the accrued oxidative stress leads to oxidative-damage-linked age-associated diseases. In this review we examine the literature on ROS, its relation to disease and the lessons gleaned from a comparative approach based upon species with widely divergent responses. We specifically focus on the longest lived rodent, the naked mole-rat, which maintains good health and provides novel insights into the paradox of maintaining both an extended healthspan and lifespan despite high oxidative stress from a young age.

  13. Raman scattering temperature measurements for water vapor in nonequilibrium dispersed two-phase flow

    International Nuclear Information System (INIS)

    Anastasia, C.M.; Neti, S.; Smith, W.R.; Chen, J.C.

    1982-09-01

    The objective of this investigation was to determine the feasibility of using Raman scattering as a nonintrusive technique to measure vapor temperatures in dispersed two-phase flow. The Raman system developed for this investigation is described, including alignment of optics and optimization of the photodetector for photon pulse counting. Experimentally obtained Raman spectra are presented for the following single- and two-phase samples: liquid water, atmospheric nitrogen, superheated steam, nitrogen and water droplets in a high void fraction air/water mist, and superheated water vapor in nonequilibrium dispersed flow

  14. Fractional laser skin resurfacing.

    Science.gov (United States)

    Alexiades-Armenakas, Macrene R; Dover, Jeffrey S; Arndt, Kenneth A

    2012-11-01

    Laser skin resurfacing (LSR) has evolved over the past 2 decades from traditional ablative to fractional nonablative and fractional ablative resurfacing. Traditional ablative LSR was highly effective in reducing rhytides, photoaging, and acne scarring but was associated with significant side effects and complications. In contrast, nonablative LSR was very safe but failed to deliver consistent clinical improvement. Fractional LSR has achieved the middle ground; it combined the efficacy of traditional LSR with the safety of nonablative modalities. The first fractional laser was a nonablative erbium-doped yttrium aluminum garnet (Er:YAG) laser that produced microscopic columns of thermal injury in the epidermis and upper dermis. Heralding an entirely new concept of laser energy delivery, it delivered the laser beam in microarrays. It resulted in microscopic columns of treated tissue and intervening areas of untreated skin, which yielded rapid reepithelialization. Fractional delivery was quickly applied to ablative wavelengths such as carbon dioxide, Er:YAG, and yttrium scandium gallium garnet (2,790 nm), providing more significant clinical outcomes. Adjustable laser parameters, including power, pitch, dwell time, and spot density, allowed for precise determination of percent surface area, affected penetration depth, and clinical recovery time and efficacy. Fractional LSR has been a significant advance to the laser field, striking the balance between safety and efficacy.

  15. Monofilament Vaporization Propulsion (MVP) System, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Monofilament Vaporization Propulsion (MVP) is a new propulsion technology targeted at secondary payload applications. It does not compromise on performance while...

  16. Experiences of marijuana-vaporizer users.

    Science.gov (United States)

    Malouff, John M; Rooke, Sally E; Copeland, Jan

    2014-01-01

    Using a marijuana vaporizer may have potential harm-reduction advantages on smoking marijuana, in that the user does not inhale smoke. Little research has been published on use of vaporizers. In the first study of individuals using a vaporizer on their own initiative, 96 adults anonymously answered questions about their experiences with a vaporizer and their use of marijuana with tobacco. Users identified 4 advantages to using a vaporizer over smoking marijuana: perceived health benefits, better taste, no smoke smell, and more effect from the same amount of marijuana. Users identified 2 disadvantages: inconvenience of setup and cleaning and the time it takes to get the device operating for each use. Only 2 individuals combined tobacco in the vaporizer mix, whereas 15 combined tobacco with marijuana when they smoked marijuana. Almost all participants intended to continue using a vaporizer. Vaporizers seem to have appeal to marijuana users, who perceive them as having harm-reduction and other benefits. Vaporizers are worthy of experimental research evaluating health-related effects of using them.

  17. Vapor pressures and thermophysical properties of selected hexenols and recommended vapor pressure for hexan-1-ol

    Czech Academy of Sciences Publication Activity Database

    Štejfa, V.; Fulem, Michal; Růžička, K.; Matějka, P.

    2015-01-01

    Roč. 402, Sep (2015), 18-29 ISSN 0378-3812 Institutional support: RVO:68378271 Keywords : alcohols * vapor pressure * heat capacity * ideal - gas thermodynamic properties * vaporization enthalpy Subject RIV: BJ - Thermodynamics Impact factor: 1.846, year: 2015

  18. Disparate patterns of age-related changes in lipid peroxidation in long-lived naked mole-rats and shorter-lived mice.

    Science.gov (United States)

    Andziak, Blazej; Buffenstein, Rochelle

    2006-12-01

    A key tenet of the oxidative stress theory of aging is that levels of accrued oxidative damage increase with age. Differences in damage generation and accumulation therefore may underlie the natural variation in species longevity. We compared age-related profiles of whole-organism lipid peroxidation (urinary isoprostanes) and liver lipid damage (malondialdehyde) in long living naked mole-rats [maximum lifespan (MLS) > 28.3 years] and shorter-living CB6F1 hybrid mice (MLS approximately 3.5 years). In addition, we compared age-associated changes in liver non-heme iron to assess how intracellular conditions, which may modulate oxidative processes, are affected by aging. Surprisingly, even at a young age, concentrations of both markers of lipid peroxidation, as well as of iron, were at least twofold (P naked mole tats than in mice. This refutes the hypothesis that prolonged naked mole-rat longevity is due to superior protection against oxidative stress. The age-related profiles of all three parameters were distinctly species specific. Rates of lipid damage generation in mice were maintained throughout adulthood, while accrued damage in old animals was twice that of young mice. In naked mole-rats, urinary isoprostane excretion declined by half with age (P naked mole-rats is independent of oxidative stress parameters.

  19. Fos expression in the suprachiasmatic nucleus in response to light stimulation in a solitary and social species of African mole-rat (family Bathyergidae).

    Science.gov (United States)

    Oosthuizen, M K; Bennett, N C; Cooper, H M

    2005-01-01

    Mole-rats are strictly subterranean rodents that are rarely exposed to environmental light. They are well adapted to their environment and have reduced eyes and a severely regressed visual system. It has been shown, however, that mole-rats do exhibit endogenous circadian rhythms that can be entrained, suggesting an intact and functional circadian system. To determine whether light is the entraining agent in these animals, Fos expression in response to light pulses at different circadian times was investigated to obtain phase response curves. Light is integrated effectively in the suprachiasmatic nucleus of the Cape mole-rat (Georychus capensis), and Fos expression is gated according to the phase of the circadian clock. The Fos response in the Cape mole-rat was comparable to that of aboveground rodents. In contrast, the highveld mole-rat (Cryptomys hottentotus pretoriae) was less sensitive to light and did not show a selective Fos response according to the phase of the circadian cycle. Social species appear to be less sensitive to light than their solitary counterparts, which compares well with results from locomotor activity studies.

  20. Void fraction measurements using neutron radiography

    International Nuclear Information System (INIS)

    Glickstein, S.S.; Vance, W.H.; Joo, H.

    1992-01-01

    Real-time neutron radiography is being evaluated for studying the dynamic behavior of two phase flow and for measuring void fraction in vertical and inclined water ducts. This technique provides a unique means of visualizing the behavior of fluid flow inside thick metal enclosures. To simulate vapor conditions encountered in a fluid flow duct, an air-water flow system was constructed. Air was injected into the bottom of the duct at flow rates up to 0.47 I/s (1 cfm). The water flow rate was varied between 0--3.78 I/m (0--1 gpm). The experiments were performed at the Pennsylvania State University nuclear reactor facility using a real-time neutron radiography camera. With a thermal neutron flux on the order of 10 6 n/cm 2 /s directed through the thin duct dimension, the dynamic behavior of the air bubbles was clearly visible through 5 cm (2 in.) thick aluminum support plates placed on both sides of the duct wall. Image analysis techniques were employed to extract void fractions from the data which was recorded on videotape. This consisted of time averaging 256 video frames and measuring the gray level distribution throughout the region. The distribution of the measured void fraction across the duct was determined for various air/water mixtures. Details of the results of experiments for a variety of air and water flow conditions are presented

  1. Continuous fraction collection of gas chromatographic separations with parallel mass spectrometric detection applied to cell-based bioactivity analysis

    NARCIS (Netherlands)

    Jonker, Willem; Zwart, Nick; Stockl, Jan B.; de Koning, Sjaak; Schaap, Jaap; Lamoree, Marja H.; Somsen, Govert W.; Hamers, Timo; Kool, Jeroen

    2017-01-01

    We describe the development and evaluation of a GC-MS fractionation platform that combines high-resolution fraction collection of full chromatograms with parallel MS detection. A y-split at the column divides the effluent towards the MS detector and towards an inverted y-piece where vaporized trap

  2. Series expansion in fractional calculus and fractional differential equations

    OpenAIRE

    Li, Ming-Fan; Ren, Ji-Rong; Zhu, Tao

    2009-01-01

    Fractional calculus is the calculus of differentiation and integration of non-integer orders. In a recently paper (Annals of Physics 323 (2008) 2756-2778), the Fundamental Theorem of Fractional Calculus is highlighted. Based on this theorem, in this paper we introduce fractional series expansion method to fractional calculus. We define a kind of fractional Taylor series of an infinitely fractionally-differentiable function. Further, based on our definition we generalize hypergeometric functio...

  3. Enthalpy of vaporization and vapor pressure of whiskey lactone and menthalactone by correlation gas chromatography

    International Nuclear Information System (INIS)

    Simmons, Daniel; Chickos, James

    2017-01-01

    Highlights: • The vapor pressure and vaporization enthalpies of cis and trans-whiskey lactone have been evaluated. • Enthalpies of vaporization and vapor pressures of (+)-isomintlactone and (−)-mintlactone were also evaluated. • The sublimation enthalpy and corresponding vapor pressure of (+) -isomintlactone at T = 298.15 K is estimated. - Abstract: Enthalpies of vaporization at T = 298.15 K of cis and trans-whiskey lactone have been evaluated by correlation gas chromatography to be (68.4 ± 1.7) kJ·mol −1 and (67.5 ± 1.7) kJ·mol −1 , respectively. The enthalpies of vaporization of isomintlactone and mintlactone also evaluated by correlation gas chromatography have been found to have vaporization enthalpies of (74.2 ± 1.8) kJ·mol −1 and (73.2 ± 1.8) kJ·mol −1 respectively. The vapor pressures for cis and trans-whiskey lactone at T = 298.15 K have been evaluated as (1.5 ± 0.09) Pa and (2.0 ± 0.1) Pa using vapor pressures of a series of lactones as standards. Vapor pressures for isomintlactone and mintlactone were evaluated as (0.26 ± 0.012) Pa and (0.33 ± 0.02) Pa, respectively. Fusion and sublimation enthalpies for (+)-isomintlactone as well as the vapor pressure of the solid have been estimated.

  4. Optical Sensor for Diverse Organic Vapors at ppm Concentration Ranges

    Directory of Open Access Journals (Sweden)

    Dora M. Paolucci

    2011-03-01

    Full Text Available A broadly responsive optical organic vapor sensor is described that responds to low concentrations of organic vapors without significant interference from water vapor. Responses to several classes of organic vapors are highlighted, and trends within classes are presented. The relationship between molecular properties (vapor pressure, boiling point, polarizability, and refractive index and sensor response are discussed.

  5. Atomic vapor laser isotope separation

    International Nuclear Information System (INIS)

    Stern, R.C.; Paisner, J.A.

    1985-01-01

    Atomic vapor laser isotope separation (AVLIS) is a general and powerful technique. A major present application to the enrichment of uranium for light-water power reactor fuel has been under development for over 10 years. In June 1985 the Department of Energy announced the selection of AVLIS as the technology to meet the nation's future need for the internationally competitive production of uranium separative work. The economic basis for this decision is considered, with an indicated of the constraints placed on the process figures of merit and the process laser system. We then trace an atom through a generic AVLIS separator and give examples of the physical steps encountered, the models used to describe the process physics, the fundamental parameters involved, and the role of diagnostic laser measurements

  6. FRACTIONS: CONCEPTUAL AND DIDACTIC ASPECTS

    OpenAIRE

    Sead Rešić; Ismet Botonjić; Maid Omerović

    2016-01-01

    Fractions represent the manner of writing parts of whole numbers (integers). Rules for operations with fractions differ from rules for operations with integers. Students face difficulties in understanding fractions, especially operations with fractions. These difficulties are well known in didactics of Mathematics throughout the world and there is a lot of research regarding problems in learning about fractions. Methods for facilitating understanding fractions have been discovered...

  7. SOIL VAPOR EXTRACTION TECHNOLOGY: REFERENCE HANDBOOK

    Science.gov (United States)

    Soil vapor extraction (SVE) systems are being used in Increasing numbers because of the many advantages these systems hold over other soil treatment technologies. SVE systems appear to be simple in design and operation, yet the fundamentals governing subsurface vapor transport ar...

  8. Mechanics of gas-vapor bubbles

    NARCIS (Netherlands)

    Hao, Yue; Zhang, Yuhang; Prosperetti, Andrea

    2017-01-01

    Most bubbles contain a mixture of vapor and incondensible gases. While the limit cases of pure vapor and pure gas bubbles are well studied, much less is known about the more realistic case of a mixture. The bubble contents continuously change due to the combined effects of evaporation and

  9. Vapor Pressures of Several Commercially Used Alkanolamines

    NARCIS (Netherlands)

    Klepacova, Katarina; Huttenhuis, Patrick J. G.; Derks, Peter W. J.; Versteeg, Geert F.; Klepáčová, Katarína

    For the design of acid gas treating processes, vapor-liquid equilibrium (VLE) data must be available of the solvents to be applied. In this study the vapor pressures of seven frequently industrially used alkanolamines (diethanolamine, N-methylethanolamine, N,N-dimethylethanolamine,

  10. Recommended Vapor Pressure of Solid Naphthalen

    Czech Academy of Sciences Publication Activity Database

    Růžička, K.; Fulem, Michal; Růžička, V.

    2005-01-01

    Roč. 50, - (2005), s. 1956-1970 ISSN 0021-9568 Institutional research plan: CEZ:AV0Z10100521 Keywords : solid naphthalene * vapor pressure * enthalpy of vaporization * enthalpy of fusion Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.610, year: 2005

  11. Effect of granosan vapors on mitosis

    Energy Technology Data Exchange (ETDEWEB)

    Lishenko, N P; Lishenko, I D

    1974-01-01

    Experiments were performed to determine the effects of granosan on the germination of vetch seeds. Vetch seeds were stored from 4-6 days in ethyl mercuric chloride vapors. Results indicated that the vapors caused a sharp decrease in germination and caused chromosomal aberrations during the anaphase.

  12. Condensation of vapor bubble in subcooled pool

    Science.gov (United States)

    Horiuchi, K.; Koiwa, Y.; Kaneko, T.; Ueno, I.

    2017-02-01

    We focus on condensation process of vapor bubble exposed to a pooled liquid of subcooled conditions. Two different geometries are employed in the present research; one is the evaporation on the heated surface, that is, subcooled pool boiling, and the other the injection of vapor into the subcooled pool. The test fluid is water, and all series of the experiments are conducted under the atmospheric pressure condition. The degree of subcooling is ranged from 10 to 40 K. Through the boiling experiment, unique phenomenon known as microbubble emission boiling (MEB) is introduced; this phenomenon realizes heat flux about 10 times higher than the critical heat flux. Condensation of the vapor bubble is the key phenomenon to supply ambient cold liquid to the heated surface. In order to understand the condensing process in the MEB, we prepare vapor in the vapor generator instead of the evaporation on the heated surface, and inject the vapor to expose the vapor bubble to the subcooled liquid. Special attention is paid to the dynamics of the vapor bubble detected by the high-speed video camera, and on the enhancement of the heat transfer due to the variation of interface area driven by the condensation.

  13. 40 CFR 796.1950 - Vapor pressure.

    Science.gov (United States)

    2010-07-01

    ... (CONTINUED) CHEMICAL FATE TESTING GUIDELINES Physical and Chemical Properties § 796.1950 Vapor pressure. (a.... In addition, chemicals that are likely to be gases at ambient temperatures and which have low water... gases until the measured vapor pressure is constant, a process called “degassing.” Impurities more...

  14. Risk assessment of metal vapor arcing

    Science.gov (United States)

    Hill, Monika C. (Inventor); Leidecker, Henning W. (Inventor)

    2009-01-01

    A method for assessing metal vapor arcing risk for a component is provided. The method comprises acquiring a current variable value associated with an operation of the component; comparing the current variable value with a threshold value for the variable; evaluating compared variable data to determine the metal vapor arcing risk in the component; and generating a risk assessment status for the component.

  15. Fractional-order devices

    CERN Document Server

    Biswas, Karabi; Caponetto, Riccardo; Mendes Lopes, António; Tenreiro Machado, José António

    2017-01-01

    This book focuses on two specific areas related to fractional order systems – the realization of physical devices characterized by non-integer order impedance, usually called fractional-order elements (FOEs); and the characterization of vegetable tissues via electrical impedance spectroscopy (EIS) – and provides readers with new tools for designing new types of integrated circuits. The majority of the book addresses FOEs. The interest in these topics is related to the need to produce “analogue” electronic devices characterized by non-integer order impedance, and to the characterization of natural phenomena, which are systems with memory or aftereffects and for which the fractional-order calculus tool is the ideal choice for analysis. FOEs represent the building blocks for designing and realizing analogue integrated electronic circuits, which the authors believe hold the potential for a wealth of mass-market applications. The freedom to choose either an integer- or non-integer-order analogue integrator...

  16. Clinical significance of measurement of changes of serum TNF-α and EGF levels after chemotherapy in patients with malignant hydatidiform mole

    International Nuclear Information System (INIS)

    Chen Xiaochao; Zhou Dongxia; Zhang Liming

    2008-01-01

    Objective: To study the clinical significance of changes of serum TNF-α and EGF levels after chemotherapy in patients with malignant hydatidiform mole. Methods: Serum TNF-α, EGF levels (with RIA) were measured both before and after chemotherapy in 32 patients with malignant hydatidiform mole as well as in 35 controls. Results: Before chemotherapy, serum TNF- α and EGF levels were significantly higher in the patients than those in controls (P<0.01). Six months after chemotherapy, serum TNF-α and EGF levels, though dropped markedly, remained significantly higher than those in controls (P<0.05). Conclusion: Development of malignant hydatidiform mole in patients was closely related to the serum TNF-α and EGF levels. (authors)

  17. EQUATION OF STATE IN FORM WHICH RELATES MOL FRACTION AND MOLARITY OF TWO (OR MORE COMPONENT THERMODYNAMIC SYSTEM CONSISTED OF IDEAL GASES, AND IT'S APPLICATIONS

    Directory of Open Access Journals (Sweden)

    Marko Popović

    2010-01-01

    Full Text Available Most people would face a problem if there is a need to calculate the mole fraction of a substance A in a gaseous solution (a thermodynamic system containing two or more ideal gases knowing its molarity at a given temperature and pressure. For most it would take a lot of time and calculations to find the answer, especially because the quantities of other substances in the system aren't given. An even greater problem arises when we try to understand how special relativity affects gaseous systems, especially solutions and systems in equilibrium. In this paper formulas are suggested that greatly shorten the process of conversion from molarity to mole fraction and give us a better insight into the relativistic effects on a gaseous system.

  18. The naked mole-rat exhibits an unusual cardiac myofilament protein profile providing new insights into heart function of this naturally subterranean rodent.

    Science.gov (United States)

    Grimes, Kelly M; Barefield, David Y; Kumar, Mohit; McNamara, James W; Weintraub, Susan T; de Tombe, Pieter P; Sadayappan, Sakthivel; Buffenstein, Rochelle

    2017-12-01

    The long-lived, hypoxic-tolerant naked mole-rat well-maintains cardiac function over its three-decade-long lifespan and exhibits many cardiac features atypical of similar-sized laboratory rodents. For example, they exhibit low heart rates and resting cardiac contractility, yet have a large cardiac reserve. These traits are considered ecophysiological adaptations to their dank subterranean atmosphere of low oxygen and high carbon dioxide levels and may also contribute to negligible declines in cardiac function during aging. We asked if naked mole-rats had a different myofilament protein signature to that of similar-sized mice that commonly show both high heart rates and high basal cardiac contractility. Adult mouse ventricles predominantly expressed α-myosin heavy chain (97.9 ± 0.4%). In contrast, and more in keeping with humans, β myosin heavy chain was the dominant isoform (79.0 ± 2.0%) in naked mole-rat ventricles. Naked mole-rat ventricles diverged from those of both humans and mice, as they expressed both cardiac and slow skeletal isoforms of troponin I. This myofilament protein profile is more commonly observed in mice in utero and during cardiomyopathies. There were no species differences in phosphorylation of cardiac myosin binding protein-C or troponin I. Phosphorylation of both ventricular myosin light chain 2 and cardiac troponin T in naked mole-rats was approximately half that observed in mice. Myofilament function was also compared between the two species using permeabilized cardiomyocytes. Together, these data suggest a cardiac myofilament protein signature that may contribute to the naked mole-rat's suite of adaptations to its natural subterranean habitat.

  19. Safety assessment of in-vessel vapor explosion loads in next generation reactor

    Energy Technology Data Exchange (ETDEWEB)

    Bang, Kwang Hyun; Cho, Jong Rae; Choi, Byung Uk; Kim, Ki Yong; Lee, Kyung Jung [Korea Maritime University, Busan (Korea); Park, Ik Kyu [Seoul National University, Seoul (Korea)

    1998-12-01

    A safety assessment of the reactor vessel lower head integrity under in-vessel vapor explosion loads has been performed. The premixing and explosion calculations were performed using TRACER-II code. Using the calculated explosion pressures imposed on the lower head inner wall, strain calculations were performed using ANSYS code. The explosion analyses show that the explosion impulses are not altered significantly by the uncertain parameters of triggering location and time, fuel and vapor volume fractions in uniform premixture bounding calculations within the conservative ranges. Strain analyses using the calculated pressure loads on the lower head inner wall show that the vapor explosion-induced lower head failure is physically unreasonable. The static analysis using the conservative explosion-end pressure of 7,246 psia shows that the maximum equivalent strain is 4.3% at the bottom of lower head, which is less than the allowable threshold value of 11%. (author). 24 refs., 40 figs., 3 tabs.

  20. A two staged condensation of vapors of an isobutane tower in installations for sulfuric acid alkylation

    Energy Technology Data Exchange (ETDEWEB)

    Smirnov, N.P.; Feyzkhanov, R.I.; Idrisov, A.D.; Navalikhin, P.G.; Sakharov, V.D.

    1983-01-01

    In order to increase the concentration of isobutane to greater than 72 to 76 percent in an installation for sulfuric acid alkylation, a system of two staged condensation of vapors from an isobutane tower is placed into operation. The first stage condenses the heavier part of the upper distillate of the tower, which is achieved through somewhat of an increase in the condensate temperature. The product which is condensed in the first stage is completely returned to the tower as a live irrigation. The vapors of the isobutane fraction which did not condense in the first stage are sent to two newly installed condensers, from which the product after condensation passes through intermediate tanks to further depropanization. The two staged condensation of vapors of the isobutane tower reduces the content of the inert diluents, the propane and n-butane in the upper distillate of the isobutane tower and creates more favorable conditions for the operation of the isobutane and propane tower.

  1. Building blocks for ionic liquids: Vapor pressures and vaporization enthalpies of 1-(n-alkyl)-imidazoles

    International Nuclear Information System (INIS)

    Emel'yanenko, Vladimir N.; Portnova, Svetlana V.; Verevkin, Sergey P.; Skrzypczak, Andrzej; Schubert, Thomas

    2011-01-01

    Highlights: → We measured vapor pressures of the 1-(n-alkyl)-imidazoles by transpiration method. → Variations on the alkyl chain length n were C 3 , C 5 -C 7 , and C 9 -C 10 . → Enthalpies of vaporization were derived from (p, T) dependencies. → Enthalpies of vaporization at 298.15 K were linear dependent on the chain length. - Abstract: Vapor pressures of the linear 1-(n-alkyl)-imidazoles with the alkyl chain C 3 , C 5 -C 7 , and C 9 -C 10 have been measured by the transpiration method. The molar enthalpies of vaporization Δ l g H m of these compounds were derived from the temperature dependencies of vapor pressures. A linear correlation of enthalpies of vaporization Δ l g H m (298.15 K) of the 1-(n-alkyl)-imidazoles with the chain length has been found.

  2. Fractional gradient and its application to the fractional advection equation

    OpenAIRE

    D'Ovidio, M.; Garra, R.

    2013-01-01

    In this paper we provide a definition of fractional gradient operators, related to directional derivatives. We develop a fractional vector calculus, providing a probabilistic interpretation and mathematical tools to treat multidimensional fractional differential equations. A first application is discussed in relation to the d-dimensional fractional advection-dispersion equation. We also study the connection with multidimensional L\\'evy processes.

  3. Familial atypical multiple mole melanoma syndrome in an adult Indian male-case report and literature review

    Directory of Open Access Journals (Sweden)

    Radhika C G Raj

    2015-01-01

    Full Text Available Familial atypical multiple mole melanoma syndrome (FAMMMS is an autosomal dominant genodermatosis characterized by multiple melanocytic nevi, usually more than 50, and a family history of melanoma. It is known to be associated with carcinoma of pancreas and other malignancies involving gastrointestinal tract, breast, lung, larynx, and skin in the kindred. There is no published report of FAMMMS in dark-skinned individuals. We report a case of FAMMMS in a dark-skinned adult Indian male, who had multiple extensive nevi all over the body and oral mucosa; associated with malignant melanoma, squamous cell carcinoma (Marjolin′s ulcer, and carcinoma of pancreas. His father had died of carcinoma of lung and his sister had a partial phenotypic expression. The clinical presentation of the case is discussed with review of literature.

  4. Thujone-Rich Fraction of Thuja occidentalis Demonstrates Major Anti-Cancer Potentials: Evidences from In Vitro Studies on A375 Cells

    OpenAIRE

    Biswas, Raktim; Mandal, Sushil Kumar; Dutta, Suman; Bhattacharyya, Soumya Sundar; Boujedaini, Naoual; Khuda-Bukhsh, Anisur Rahman

    2011-01-01

    Crude ethanolic extract of Thuja occidentalis (Fam: Cupressaceae) is used as homeopathic mother tincture (TOΦ) to treat various ailments, particularly moles and tumors, and also used in various other systems of traditional medicine. Anti-proliferative and apoptosis-inducing properties of TOΦ and the thujone-rich fraction (TRF) separated from it have been evaluated for their possible anti-cancer potentials in the malignant melanoma cell line A375. On initial trial by S-diphenyltetrazolium brom...

  5. Sweet Work with Fractions

    Science.gov (United States)

    Vinogradova, Natalya; Blaine, Larry

    2013-01-01

    Almost everyone loves chocolate. However, the same cannot be said about fractions, which are loved by markedly fewer. Middle school students tend to view them with wary respect, but little affection. The authors attempt to sweeten the subject by describing a type of game involving division of chocolate bars. The activity they describe provides a…

  6. Fermion Number Fractionization

    Indian Academy of Sciences (India)

    Srimath

    1 . In tro d u ctio n. T he N obel P rize in C hem istry for the year 2000 w as aw arded to A lan J H ... soliton, the ground state of the ferm ion-soliton system can have ..... probability density,in a heuristic w ay that a fractional ferm ion num ber m ay ...

  7. Momentum fractionation on superstrata

    International Nuclear Information System (INIS)

    Bena, Iosif; Martinec, Emil; Turton, David; Warner, Nicholas P.

    2016-01-01

    Superstrata are bound states in string theory that carry D1, D5, and momentum charges, and whose supergravity descriptions are parameterized by arbitrary functions of (at least) two variables. In the D1-D5 CFT, typical three-charge states reside in high-degree twisted sectors, and their momentum charge is carried by modes that individually have fractional momentum. Understanding this momentum fractionation holographically is crucial for understanding typical black-hole microstates in this system. We use solution-generating techniques to add momentum to a multi-wound supertube and thereby construct the first examples of asymptotically-flat superstrata. The resulting supergravity solutions are horizonless and smooth up to well-understood orbifold singularities. Upon taking the AdS_3 decoupling limit, our solutions are dual to CFT states with momentum fractionation. We give a precise proposal for these dual CFT states. Our construction establishes the very nontrivial fact that large classes of CFT states with momentum fractionation can be realized in the bulk as smooth horizonless supergravity solutions.

  8. Fractional Differential Equation

    Directory of Open Access Journals (Sweden)

    Moustafa El-Shahed

    2007-01-01

    where 2<α<3 is a real number and D0+α is the standard Riemann-Liouville fractional derivative. Our analysis relies on Krasnoselskiis fixed point theorem of cone preserving operators. An example is also given to illustrate the main results.

  9. Brewing with fractionated barley

    NARCIS (Netherlands)

    Donkelaar, van L.H.G.

    2016-01-01

    Brewing with fractionated barley

    Beer is a globally consumed beverage, which is produced from malted barley, water, hops and yeast. In recent years, the use of unmalted barley and exogenous enzymes have become more popular because they enable simpler processing and reduced environmental

  10. Fractionation and rectification apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Sauerwald, A

    1932-05-25

    Fractionation and rectifying apparatus with a distillation vessel and a stirring tube, drainage tubes leading from its coils to a central collecting tube, the drainage tubes being somewhat parallel and attached to the outer half of the stirring tube and partly on the inner half of the central collecting tube, whereby distillation and rectification can be effected in a single apparatus.

  11. Fractional charge search

    International Nuclear Information System (INIS)

    Innes, W.; Klein, S.; Perl, M.; Price, J.C.

    1982-06-01

    A device to search for fractional charge in matter is described. The sample is coupled to a low-noise amplifier by a periodically varying capacitor and the resulting signal is synchronously detected. The varying capacitor is constructed as a rapidly spinning wheel. Samples of any material in volumes of up to 0.05 ml may be searched in less than an hour

  12. Spatial and temporal activity patterns of the free-living giant mole-rat (Fukomys mechowii, the largest social bathyergid.

    Directory of Open Access Journals (Sweden)

    Matěj Lövy

    Full Text Available Despite the considerable attention devoted to the biology of social species of African mole-rats (Bathyergidae, Rodentia, knowledge is lacking about their behaviour under natural conditions. We studied activity of the largest social bathyergid, the giant mole-rat Fukomys mechowii, in its natural habitat in Zambia using radio-telemetry. We radio-tracked six individuals during three continuous 72-h sessions. Five of these individuals, including a breeding male, belonged to a single family group; the remaining female was probably a solitary disperser. The non-breeders of the family were active (i.e. outside the nest 5.8 hours per 24h-day with the activity split into 6.5 short bouts. The activity was more concentrated in the night hours, when the animals also travelled longer distances from the nest. The breeding male spent only 3.2 hours per day outside the nest, utilizing less than 20% of the whole family home range. The dispersing female displayed a much different activity pattern than the family members. Her 8.0 hours of outside-nest activity per day were split into 4.6 bouts which were twice as long as in the family non-breeders. Her activity peak in the late afternoon coincided with the temperature maximum in the depth of 10 cm (roughly the depth of the foraging tunnels. Our results suggest that the breeding individuals (at least males contribute very little to the work of the family group. Nevertheless, the amount of an individual's activity and its daily pattern are probably flexible in this species and can be modified in response to actual environmental and social conditions.

  13. Response of mole crab, Emerita emeritus to the thermal effluents from the Madras Atomic Power Station at Kalpakkam

    International Nuclear Information System (INIS)

    Subramoniam, T.; Munuswamy, N.; Israel, Sunil; Sathish, R.; Venugopalan, V.P.

    2007-01-01

    Mole crabs belonging to the genus Emerita are exclusively inhabitants of exposed wave washed sandy beaches in certain temperate and tropical seas. Its sedentary adult life and a primitive filter-feeding behavior make this intertidal crab an excellent indicator species for monitoring anthropogenic impact. Hence, this sand crab has been used to determine the effect of elevated temperature (rT) arising out of the thermal effluent from the Madras Atomic Power Station (MAPS), Kalpakkam with special reference to the intertidal fauna. Since Emerita exhibits limited capacity to move from their place of habitation, an analysis of the population structure of Emerita emeritus in the Kalpakkam coast including the impacted and the adjoining control sandy beaches on either side of the mixing point in the vicinity of the power plant was done. The data indicate that in the impact zone having an elevated seawater temperature of <35 deg C, the crab is completely absent. However, as we move away from the impact zone, with normalization of seawater temperature, Emerita move to safer areas on either side of the impact zone. Thus, the extensive field data on the distribution of mole crabs indicated that population structure is affected by the thermal plume, although the shifting positions of the mixing point (caused by northerly and southerly long shore currents) allowed decolonization of Emerita due to transmigration in positions that were earlier mixing points. This paper also describes a complete larval development of Emerita emeritus in the laboratory. Different life stages of E. emeritus were subjected to various power plant stressors to determine their varying responses. The expression of heat shock protein (hsp) in the gill tissue of the adult crabs was also observed when the crabs were exposed to elevated temperatures (35 deg C). However, no expression of heat shock proteins was observed when the crabs were subjected to chlorine stress. (author)

  14. Resistance to experimental tumorigenesis in cells of a long-lived mammal, the naked mole-rat (Heterocephalus glaber).

    Science.gov (United States)

    Liang, Sitai; Mele, James; Wu, Yuehong; Buffenstein, Rochelle; Hornsby, Peter J

    2010-08-01

    The naked mole-rat (NMR, Heterocephalus glaber) is a long-lived mammal in which spontaneous cancer has not been observed. To investigate possible mechanisms for cancer resistance in this species, we studied the properties of skin fibroblasts from the NMR following transduction with oncogenes that cause cells of other mammalian species to form malignant tumors. Naked mole-rat fibroblasts were transduced with a retrovirus encoding SV40 large T antigen and oncogenic Ras(G12V). Following transplantation of transduced cells into immunodeficient mice, cells rapidly entered crisis, as evidenced by the presence of anaphase bridges, giant cells with enlarged nuclei, multinucleated cells, and cells with large number of chromosomes or abnormal chromatin material. In contrast, similarly transduced mouse and rat fibroblasts formed tumors that grew rapidly without crisis. Crisis was also observed after > 40 population doublings in SV40 TAg/Ras-expressing NMR cells in culture. Crisis in culture was prevented by additional infection of the cells with a retrovirus encoding hTERT (telomerase reverse transcriptase). SV40 TAg/Ras/hTERT-expressing NMR cells formed tumors that grew rapidly in immunodeficient mice without evidence of crisis. Crisis could also be induced in SV40 TAg/Ras-expressing NMR cells by loss of anchorage, but after hTERT transduction, cells were able to proliferate normally following loss of anchorage. Thus, rapid crisis is a response of oncogene-expressing NMR cells to growth in an in vivo environment, which requires anchorage independence, and hTERT permits cells to avoid crisis and to achieve malignant tumor growth. The unique reaction of NMR cells to oncogene expression may form part of the cancer resistance of this species.

  15. Metabolic clues to salubrious longevity in the brain of the longest-lived rodent: the naked mole-rat.

    Science.gov (United States)

    Triplett, Judy C; Swomley, Aaron; Kirk, Jessime; Lewis, Katilyn; Orr, Miranda; Rodriguez, Karl; Cai, Jian; Klein, Jon B; Buffenstein, Rochelle; Butterfield, D Allan

    2015-08-01

    Naked mole-rats (NMRs) are the oldest-living rodent species. Living underground in a thermally stable ecological niche, NMRs have evolved certain exceptional traits, resulting in sustained health spans, negligible cognitive decline, and a pronounced resistance to age-related disease. Uncovering insights into mechanisms underlying these extraordinary traits involved in successful aging may conceivably provide crucial clues to extend the human life span and health span. One of the most fundamental processes inside the cell is the production of ATP, which is an essential fuel in driving all other energy-requiring cellular activities. Not surprisingly, a prominent hallmark in age-related diseases, such as neurodegeneration and cancer, is the impairment and dysregulation of metabolic pathways. Using a two-dimensional polyacrylamide gel electrophoresis proteomics approach, alterations in expression and phosphorylation levels of metabolic proteins in the brains of NMRs, aged 2-24 years, were evaluated in an age-dependent manner. We identified 13 proteins with altered levels and/or phosphorylation states that play key roles in various metabolic pathways including glycolysis, β-oxidation, the malate-aspartate shuttle, the Tricarboxylic Acid Cycle (TCA) cycle, the electron transport chain, NADPH production, as well as the production of glutamate. New insights into potential pathways involved in metabolic aspects of successful aging have been obtained by the identification of key proteins through which the NMR brain responds and adapts to the aging process and how the NMR brain adapted to resist age-related degeneration. This study examines the changes in the proteome and phosphoproteome in the brain of the naked mole-rat aged 2-24 years. We identified 13 proteins (labeled in red) with altered expression and/or phosphorylation levels that are conceivably associated with sustained metabolic functions in the oldest NMRs that may promote a sustained health span and life span.

  16. Subcaste differences in neural activation suggest a prosocial role for oxytocin in eusocial naked mole-rats.

    Science.gov (United States)

    Hathaway, Georgia A; Faykoo-Martinez, Mariela; Peragine, Deane E; Mooney, Skyler J; Holmes, Melissa M

    2016-03-01

    The neuropeptide oxytocin (OT) influences prosocial behavior(s), aggression, and stress responsiveness, and these diverse effects are regulated in a species- and context-specific manner. The naked mole-rat (Heterocephalus glaber) is a unique species with which to study context-dependent effects of OT, exhibiting a strict social hierarchy with behavioral specialization within the subordinate caste: soldiers are aggressive and defend colonies against unfamiliar conspecifics while workers are prosocial and contribute to in-colony behaviors such as pup care. To determine if OT is involved in subcaste-specific behaviors, we compared behavioral responses between workers and soldiers of both sexes during a modified resident/intruder paradigm, and quantified activation of OT neurons in the hypothalamic paraventricular nucleus (PVN) and supraoptic nucleus (SON) using the immediate-early-gene marker c-fos co-localized with OT neurons. Resident workers and soldiers were age-matched with unfamiliar worker stimulus animals as intruders, and encounters were videorecorded and scored for aggressive behaviors. Colony-matched controls were left in their home colony for the duration of the encounters. Brains were extracted and cell counts were conducted for OT immunoreactive (ir), c-fos-ir, and percentage of OT-c-fos double-labeled cells. Results indicate that resident workers were less aggressive but showed greater OT neural activity than soldiers. Furthermore, a linear model including social treatment, cortisol, and subcaste revealed that subcaste was the only significant predictor of OT-c-fos double-labeled cells in the PVN. These data suggest that in naked mole-rats OT promotes prosocial behaviors rather than aggression and that even within subordinates status exerts robust effects on brain and behavior. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Vapor deposition on doublet airfoil substrates: Control of coating thickness and microstructure

    Energy Technology Data Exchange (ETDEWEB)

    Rodgers, Theron M.; Zhao, Hengbei; Wadley, Haydn N. G., E-mail: haydn@virginia.edu [Department of Materials Science and Engineering, University of Virginia, 395 McCormick Rd., P.O. Box 400745, Charlottesville, Virginia 22904 (United States)

    2015-11-15

    Gas jet assisted vapor deposition processes for depositing coatings are conducted at higher pressures than conventional physical vapor deposition methods, and have shown promise for coating complex shaped substrates including those with non-line-of-sight (NLS) regions on their surface. These regions typically receive vapor atoms at a lower rate and with a wider incident angular distribution than substrate regions in line-of-sight (LS) of the vapor source. To investigate the coating of such substrates, the thickness and microstructure variation along the inner (curved) surfaces of a model doublet airfoil containing both LS and NLS regions has been investigated. Results from atomistic simulations and experiments confirm that the coating's thickness is thinner in flux-shadowed regions than in other regions for all the coating processes investigated. They also indicated that the coatings columnar microstructure and pore volume fraction vary with surface location through the LS to NLS transition zone. A substrate rotation strategy for optimizing the thickness over the entire doublet airfoil surface was investigated, and led to the identification of a process that resulted in only small variation of coating thickness, columnar growth angle, and pore volume fraction on all doublet airfoil surfaces.

  18. Effect of water vapor on sound absorption in nitrogen at low frequency/pressure ratios

    Science.gov (United States)

    Zuckerwar, A. J.; Griffin, W. A.

    1981-01-01

    Sound absorption measurements were made in N2-H2O binary mixtures at 297 K over the frequency/pressure range f/P of 0.1-2500 Hz/atm to investigate the vibrational relaxation peak of N2 and its location on f/P axis as a function of humidity. At low humidities the best fit to a linear relationship between the f/P(max) and humidity yields an intercept of 0.013 Hz/atm and a slope of 20,000 Hz/atm-mole fraction. The reaction rate constants derived from this model are lower than those obtained from the extrapolation of previous high-temperature data.

  19. -Dimensional Fractional Lagrange's Inversion Theorem

    Directory of Open Access Journals (Sweden)

    F. A. Abd El-Salam

    2013-01-01

    Full Text Available Using Riemann-Liouville fractional differential operator, a fractional extension of the Lagrange inversion theorem and related formulas are developed. The required basic definitions, lemmas, and theorems in the fractional calculus are presented. A fractional form of Lagrange's expansion for one implicitly defined independent variable is obtained. Then, a fractional version of Lagrange's expansion in more than one unknown function is generalized. For extending the treatment in higher dimensions, some relevant vectors and tensors definitions and notations are presented. A fractional Taylor expansion of a function of -dimensional polyadics is derived. A fractional -dimensional Lagrange inversion theorem is proved.

  20. Effect of melt surface depression on the vaporization rate of a metal heated by an electron beam

    International Nuclear Information System (INIS)

    Guilbaud, D.

    1995-01-01

    In order to produce high density vapor, a metal confined in a water cooled crucible is heated by an electron beam (eb). The energy transfer to the metal causes partial melting, forming a pool where the flow is driven by temperature induced buoyancy and capillary forces. Furthermore, when the vaporization rate is high, the free surface is depressed by the thrust of the vapor. The main objective of this paper is to analyse the combined effects of liquid flow and vapor condensation back on the liquid surface. This is done with TRIO-EF, a general purpose fluid mechanics finite element code. A suitable iterative scheme is used to calculate the free surface flow and the temperature field. The numerical simulation gives an insight about the influence of the free surface in heat transfer. The depression of the free surface induces strong effects on both liquid and vapor. As liquid is concerned, buoyancy convection in the pool is enhanced, the energy flux from electron beam is spread and constriction of heat flux under the eb spot is weakened. It results that heat transfer towards the crucible is reinforced. As vapor is concerned, its fraction that condenses back on the liquid surface is increased. These phenomena lead to a saturation of the net vaporization rate as the eb spot radius is reduced, at constant eb power. (author). 8 refs., 13 figs., 2 tabs

  1. Gauge invariant fractional electromagnetic fields

    International Nuclear Information System (INIS)

    Lazo, Matheus Jatkoske

    2011-01-01

    Fractional derivatives and integrations of non-integers orders was introduced more than three centuries ago but only recently gained more attention due to its application on nonlocal phenomenas. In this context, several formulations of fractional electromagnetic fields was proposed, but all these theories suffer from the absence of an effective fractional vector calculus, and in general are non-causal or spatially asymmetric. In order to deal with these difficulties, we propose a spatially symmetric and causal gauge invariant fractional electromagnetic field from a Lagrangian formulation. From our fractional Maxwell's fields arose a definition for the fractional gradient, divergent and curl operators. -- Highlights: → We propose a fractional Lagrangian formulation for fractional Maxwell's fields. → We obtain gauge invariant fractional electromagnetic fields. → Our generalized fractional Maxwell's field is spatially symmetrical. → We discuss the non-causality of the theory.

  2. Gauge invariant fractional electromagnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Lazo, Matheus Jatkoske, E-mail: matheuslazo@furg.br [Instituto de Matematica, Estatistica e Fisica - FURG, Rio Grande, RS (Brazil)

    2011-09-26

    Fractional derivatives and integrations of non-integers orders was introduced more than three centuries ago but only recently gained more attention due to its application on nonlocal phenomenas. In this context, several formulations of fractional electromagnetic fields was proposed, but all these theories suffer from the absence of an effective fractional vector calculus, and in general are non-causal or spatially asymmetric. In order to deal with these difficulties, we propose a spatially symmetric and causal gauge invariant fractional electromagnetic field from a Lagrangian formulation. From our fractional Maxwell's fields arose a definition for the fractional gradient, divergent and curl operators. -- Highlights: → We propose a fractional Lagrangian formulation for fractional Maxwell's fields. → We obtain gauge invariant fractional electromagnetic fields. → Our generalized fractional Maxwell's field is spatially symmetrical. → We discuss the non-causality of the theory.

  3. On matrix fractional differential equations

    Directory of Open Access Journals (Sweden)

    Adem Kılıçman

    2017-01-01

    Full Text Available The aim of this article is to study the matrix fractional differential equations and to find the exact solution for system of matrix fractional differential equations in terms of Riemann–Liouville using Laplace transform method and convolution product to the Riemann–Liouville fractional of matrices. Also, we show the theorem of non-homogeneous matrix fractional partial differential equation with some illustrative examples to demonstrate the effectiveness of the new methodology. The main objective of this article is to discuss the Laplace transform method based on operational matrices of fractional derivatives for solving several kinds of linear fractional differential equations. Moreover, we present the operational matrices of fractional derivatives with Laplace transform in many applications of various engineering systems as control system. We present the analytical technique for solving fractional-order, multi-term fractional differential equation. In other words, we propose an efficient algorithm for solving fractional matrix equation.

  4. Water vapor retrieval over many surface types

    Energy Technology Data Exchange (ETDEWEB)

    Borel, C.C.; Clodius, W.C.; Johnson, J.

    1996-04-01

    In this paper we present a study of of the water vapor retrieval for many natural surface types which would be valuable for multi-spectral instruments using the existing Continuum Interpolated Band Ratio (CIBR) for the 940 nm water vapor absorption feature. An atmospheric code (6S) and 562 spectra were used to compute the top of the atmosphere radiance near the 940 nm water vapor absorption feature in steps of 2.5 nm as a function of precipitable water (PW). We derive a novel technique called ``Atmospheric Pre-corrected Differential Absorption`` (APDA) and show that APDA performs better than the CIBR over many surface types.

  5. Finalize field testing of cold climate heat pump (CCHP) based on tandem vapor injection compressors

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Bo [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Baxter, Van D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Abdelaziz, Omar [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Rice, C. Keith [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-03-01

    This report describes the system diagram and control algorithm of a prototype air-source cold climate heat pump (CCHP) using tandem vapor injection (VI) compressors. The prototype was installed in Fairbanks, Alaska and underwent field testing starting in 09/2016. The field testing results of the past six months, including compressor run time fractions, measured COPs and heating capacities, etc., are presented as a function of the ambient temperature. Two lessons learned are also reported.

  6. Water Vapor Permeation in Plastics

    Energy Technology Data Exchange (ETDEWEB)

    Keller, Paul E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kouzes, Richard T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2017-01-01

    Polyvinyl toluene (PVT) and polystyrene (PS) (referred to as “plastic scintillator”) are used for gamma ray detectors. A significant decrease in radiation detection performance has been observed in some PVT-based gamma-ray detectors in systems in outdoor environments as they age. Recent studies have revealed that plastic scintillator can undergo an environmentally related material degradation that adversely affects gamma ray detection performance under certain conditions and histories. A significant decrease in sensitivity has been seen in some gamma-ray detectors in some systems as they age. The degradation of sensitivity of plastic scintillator over time is due to a variety of factors, and the term “aging” is used to encompass all factors. Some plastic scintillator samples show no aging effects (no significant change in sensitivity over more than 10 years), while others show severe aging (significant change in sensitivity in less than 5 years). Aging effects arise from weather (variations in heat and humidity), chemical exposure, mechanical stress, light exposure, and loss of volatile components. The damage produced by these various causes can be cumulative, causing observable damage to increase over time. Damage may be reversible up to some point, but becomes permanent under some conditions. The objective of this report is to document the phenomenon of permeability of plastic scintillator to water vapor and to derive the relationship between time, temperature, humidity and degree of water penetration in plastic. Several conclusions are documented about the properties of water permeability of plastic scintillator.

  7. The Local Fractional Bootstrap

    DEFF Research Database (Denmark)

    Bennedsen, Mikkel; Hounyo, Ulrich; Lunde, Asger

    We introduce a bootstrap procedure for high-frequency statistics of Brownian semistationary processes. More specifically, we focus on a hypothesis test on the roughness of sample paths of Brownian semistationary processes, which uses an estimator based on a ratio of realized power variations. Our...... new resampling method, the local fractional bootstrap, relies on simulating an auxiliary fractional Brownian motion that mimics the fine properties of high frequency differences of the Brownian semistationary process under the null hypothesis. We prove the first order validity of the bootstrap method...... and in simulations we observe that the bootstrap-based hypothesis test provides considerable finite-sample improvements over an existing test that is based on a central limit theorem. This is important when studying the roughness properties of time series data; we illustrate this by applying the bootstrap method...

  8. Fractionalization and Entrepreneurial Activities

    OpenAIRE

    Awaworyi Churchill, Sefa

    2015-01-01

    The vast majority of the literature on ethnicity and entrepreneurship focuses on the construct of ethnic entrepreneurship. However, very little is known about how ethnic heterogeneity affects entrepreneurship. This study attempts to fill the gap, and thus examines the effect of ethnic heterogeneity on entrepreneurial activities in a cross-section of 90 countries. Using indices of ethnic and linguistic fractionalization, we show that ethnic heterogeneity negatively influences entrepreneurship....

  9. Parentage analysis of Ansell’s mole-rat family groups indicates a high reproductive skew despite relatively relaxed ecological constraints on dispersal

    Czech Academy of Sciences Publication Activity Database

    Patzenhauerová, Hana; Šklíba, J.; Bryja, Josef; Šumbera, R.

    2013-01-01

    Roč. 22, č. 19 (2013), s. 4988-5000 ISSN 0962-1083 R&D Projects: GA AV ČR IAA601410802; GA ČR GAP506/10/0983 Institutional support: RVO:68081766 Keywords : African mole-rat * dispersal * eusociality * Fukomys * mating system * reproductive skew Subject RIV: EH - Ecology, Behaviour Impact factor: 5.840, year: 2013

  10. The Evasion of the Text; Invasion of the Text; Again, Evasion of the Text; "The Eagle and the Mole": The Affective Fallacy Revisited.

    Science.gov (United States)

    Ducharme, Edward R.; And Others

    1970-01-01

    Three writers debate whether English teachers should depend on external or internal criteria when analyzing and teaching literature. Each writer discusses the meaning of Elinor Wylie's poem, "The Eagle and the Mole," according to his particular view of literary analysis. Edward Ducharme, in "The Evasion of the Text," submits…

  11. Variability of space-use patterns in a free living eusocial rodent, Ansell’s mole-rat indicates age-based rather than caste polyethism

    Czech Academy of Sciences Publication Activity Database

    Šklíba, Jan; Lövy, M.; Burda, H.; Šumbera, R.

    2016-01-01

    Roč. 6, DEC 06 (2016), č. článku 37497. ISSN 2045-2322 EU Projects: European Commission(XE) 669609 - Diversity6continents Institutional support: RVO:60077344 Keywords : eusocial rodent * mole-rats * Fukomys anselli Subject RIV: EG - Zoology OBOR OECD: Zoology Impact factor: 4.259, year: 2016 https://www.nature.com/articles/srep37497

  12. An energy stable evolution method for simulating two-phase equilibria of multi-component fluids at constant moles, volume and temperature

    KAUST Repository

    Kou, Jisheng; Sun, Shuyu; Wang, Xiuhua

    2016-01-01

    In this paper, we propose an energy-stable evolution method for the calculation of the phase equilibria under given volume, temperature, and moles (VT-flash). An evolution model for describing the dynamics of two-phase fluid system is based on Fick

  13. Identification of patients with persistent trophoblastic disease after complete hydatidiform mole by using a normal 24-hour urine hCG regression curve

    NARCIS (Netherlands)

    Cromvoirt, S.M. van; Thomas, C.M.G.; Quinn, M.A.; McNally, O.M.; Bekkers, R.L.M.

    2014-01-01

    OBJECTIVE: The aim of this study was to establish a reference 24-hour urine human chorionic gonadotropin (hCG) regression curve in patients with complete hydatidiform mole (CHM) as diagnostic tool in the prediction of persistent trophoblastic disease (PTD). METHODS: From 2004 to 2011, 312 cases

  14. Fractional Number Operator and Associated Fractional Diffusion Equations

    Science.gov (United States)

    Rguigui, Hafedh

    2018-03-01

    In this paper, we study the fractional number operator as an analog of the finite-dimensional fractional Laplacian. An important relation with the Ornstein-Uhlenbeck process is given. Using a semigroup approach, the solution of the Cauchy problem associated to the fractional number operator is presented. By means of the Mittag-Leffler function and the Laplace transform, we give the solution of the Caputo time fractional diffusion equation and Riemann-Liouville time fractional diffusion equation in infinite dimensions associated to the fractional number operator.

  15. GOES WATER VAPOR TRANSPORT V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The GOES Water Vapor Transport CD contains nineteen months of geostationary satellite-derived products from the GOES-8 satellite spanning the 1987-1988 El Nino...

  16. Vaporization of Samarium trichloride studied by thermogravimetry

    International Nuclear Information System (INIS)

    Esquivel, Marcelo R.; Pasquevich, Daniel M.

    2003-01-01

    In the present work, the vaporization reaction of SmCl 3 (l) obtained from the 'in situ' reaction of Sm 2 O 3 (s) and Cl 2 (g)-C(s) was studied by thermogravimetry under controlled atmosphere. The effects of both the temperature between 825 C degrees and 950 C degrees and the total flow gas on the vaporization rate of the following reaction: SmCl 3 (l) = SmCl 3 (g) were analyzed. The vaporization rate of the process was found to be independent of then total gas flow rate and highly dependent on the temperature. E ap calculation led to a value of 240 ± 10 kJ.mol -1 . A comparison between this value and that of the molar enthalpy of vaporization allow to the conclusion that the reaction occur in conditions near to equilibrium. The SmCl 3 identity was determined by X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS). (author)

  17. Perspective: Highly stable vapor-deposited glasses

    Science.gov (United States)

    Ediger, M. D.

    2017-12-01

    This article describes recent progress in understanding highly stable glasses prepared by physical vapor deposition and provides perspective on further research directions for the field. For a given molecule, vapor-deposited glasses can have higher density and lower enthalpy than any glass that can be prepared by the more traditional route of cooling a liquid, and such glasses also exhibit greatly enhanced kinetic stability. Because vapor-deposited glasses can approach the bottom of the amorphous part of the potential energy landscape, they provide insights into the properties expected for the "ideal glass." Connections between vapor-deposited glasses, liquid-cooled glasses, and deeply supercooled liquids are explored. The generality of stable glass formation for organic molecules is discussed along with the prospects for stable glasses of other types of materials.

  18. Fundamentals of Friction and Vapor Phase Lubrication

    National Research Council Canada - National Science Library

    Gellman, Andrew

    2004-01-01

    This is the final report for the three year research program on "Fundamentals of Friction and Vapor Phase Lubrication" conducted at Carnegie Mellon with support from AFOSR grant number F49630-01-1-0069...

  19. GOES WATER VAPOR TRANSPORT V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The GOES Water Vapor Transport CD contains nineteen months of geostationary satellite-derived products spanning the 1987/1988 El Nino Southern Oscillation (ENSO)...

  20. Drag Reduction by Leidenfrost Vapor Layers

    KAUST Repository

    Vakarelski, Ivan Uriev; Marston, Jeremy O.; Chan, Derek Y. C.; Thoroddsen, Sigurdur T

    2011-01-01

    , we show that such vapor layers can reduce the hydrodynamic drag by over 85%. These results appear to approach the ultimate limit of drag reduction possible by different methods based on gas-layer lubrication and can stimulate the development