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Sample records for dehydration temperatures experiments

  1. Effect of temperature on the anthocyanin extraction and color evolution during controlled dehydration of Tempranillo grapes.

    Science.gov (United States)

    Marquez, Ana; Perez-Serratosa, Maria; Varo, M Angeles; Merida, Julieta

    2014-08-06

    In this paper, the influence of temperature during the controlled dehydration of Tempranillo red grapes has been studied. Two experiments at fixed temperatures of 30 and 40 °C, and a third experiment alternating temperatures of 40 and 15 °C every 12 h were carried out. The must from grapes dried at 40 °C presented the reddest color, and the highest anthocyanin concentration and antioxidant activity. A possible hypothesis could be that the high temperature induced a continuous water evaporation from the grapes, preventing the oxygen entry. At the same time, the dehydration resulted in broken skins, which facilitated the transfer of colored compounds to the pulp, increasing the red color of the musts. However, when the temperature dropped, oxygen could penetrate through the skin and the browning reactions started. As a result, the must obtained from gra pes dehydrated by alternating high and low temperatures presented the least anthocyanin content and the least red color.

  2. Dehydration kinetics of Portland cement paste at high temperature

    NARCIS (Netherlands)

    Zhang, Q.; Ye, G.

    2012-01-01

    Portland cement paste is a multiphase compound mainly consisting of calcium-silicate-hydrate (CSH) gel, calcium hydroxide (CH) crystal, and unhydrated cement core. When cement paste is exposed to high temperature, the dehydration of cement paste leads to not only the decline in strength, but also

  3. Dehydration kinetics of Portland cement paste at high temperature

    NARCIS (Netherlands)

    Zhang, Q.; Ye, G.

    2012-01-01

    Portland cement paste is a multiphase compound mainly consisting of calcium-silicate-hydrate (CSH) gel, calcium hydroxide (CH) crystal, and unhydrated cement core. When cement paste is exposed to high temperature, the dehydration of cement paste leads to not only the decline in strength, but also th

  4. Dehydration stress associated variations in rectal temperature, pulse and respiration rate of Marwari sheep

    Directory of Open Access Journals (Sweden)

    Saini, B. S.

    2013-04-01

    Full Text Available The present investigation was carried out in adult female Marwari sheep to evaluate the dehydration stress associated variations in rectal temperature, pulse and respiration rate. The whole experiment was divided into control, thirst and drinking periods. The thirst period was of 5 days to find out the dehydration stress. The control mean values of rectal temperature (oF, pulse rate (min -1 and respiration rate (min -1 were 101.1 ± 0.198, 65.667 ± 2.028 and 25.167 ± 1.515 in the morning and 101.567 ± 0.174, 71.333 ± 1.229 and 27.833 ± 1.83 in the evening, respectively. With the advancement of thirst period the mean values of rectal temperature and pulse rate gradually increased while that of respiration rate increased first and then decreased. After drinking the mean values gradually decreased and on hour 72 of drinking, they differed non significantly (P>0.05 from their respective control values. Changes in rectal temperature, pulse rate and respiration rate indicated the adaptability of the animals to increased thirst periods.Dehydration due to thirst period provoked physiological mechanisms in the body in a manner that helped the animals to survive. Although dehydration was a stress to the animals, but the changes brought about by five days of dehydration were reversible.

  5. Temperature dependent elasticity and damping in dehydrated sandstone

    Science.gov (United States)

    Darling, T. W.; Struble, W.

    2013-12-01

    Work reported previously at this conference, outlining our observation of anomalously large elastic softening and damping in dehydrated Berea sandstone at elevated temperatures, has been analysed to study shear and compressional effects separately. Modeling of the sample using COMSOL software was necessary to identify modes, as the vibration spectrum of the sample is poorly approximated by a uniform isotropic solid. The first torsional mode of our evacuated, dry, core softens at nearly twice the rate of Young's modulus modes (bending and compressional) and is also damped nearly twice as strongly as temperature increases. We consider two possible models for explaining this behavior, based on the assumption that the mechanical properties of the sandstone are dominated by the framework of quartz grains and polycrystalline cementation, neglecting initially the effects of clay and feldspar inclusions. The 20cm x 2.54cm diameter core is dry such that the pressure of water vapor in the experiment chamber is below 1e-6 Torr at 70C, suggesting that surface water beyond a small number of monolayers is negligible. Our models consider (1) enhanced sliding of grain boundaries in the cementation at elevated temperature and reduced internal water content, and (2) strain microcracking of the cementatioin at low water content due to anisotropic expansion in the quartz grains. In model (1) interfaces parallel to polyhedral grain surfaces were placed in the cement bonds and assigned frictional properties. Model (2) has not yet been implemented. The overall elasticity of a 3-D several-grain model network was determined by modeling quasistatic loading and measuring displacements. Initial results with a small number of grains/bonds suggests that only the first model provides softening and damping for all the modes, however the details of the effects of defect motioin at individual interfaces as the source for the frictional properties is still being evaluated. Nonlinear effects are

  6. Dehydration Temperature of Serpentine at Elevated Temperatures and Pressures by Electrical Conductivity Method and Its Implications

    Institute of Scientific and Technical Information of China (English)

    宋茂双; 谢鸿森; 等

    1996-01-01

    Dehydration temperatures of serpentine were measured in the pressure range between 1.0GPa and 5.0GPa by using the electrical conductivity metod simultaneously at high temperatures and high pressures.The results show that with increasing pressure th dehydration temperature of antigorite increases slightly below 2.0GPa ,but drops markedly above2.0GPa .This strongly suggests that high pressure would favor the dehydration of serpentine minerals and the water released thereby would be an important source of fluids involved in magmatism in a subduction zone and mantle metasomatism,Meanwhile,the greatly enhanced electric conductivity in the presence of water may be one of the reasons underlying the occurrence of a high-conductivity zone in the lower crust.

  7. Response of Bacillus subtilis spores to dehydration and UV irradiation at extremely low temperatures.

    Science.gov (United States)

    Dose, K; Klein, A

    1996-02-01

    Spores of Bacillus subtilis have been exposed to the conditions of extreme dehydration (argon/silica gel; simulated space vacuum) for up to 12 weeks at 298 K and 80 K in the dark. The inactivation has been correlated with the production of DNA-double strand-breaks. The temperature-dependence of the rate constants for inactivation or production of DNA-double strand-breaks is surprisingly low. Controls kept in the frozen state at 250 K for the same period of time showed no sign of deterioration. In another series of experiments the spores have been UV irradiated (253.7 nm) at 298 K, 200 K and 80 K after exposure to dehydrating conditions for 3 days. Fluence-effect relationships for inactivation, production of DNA-double strand-breaks and DNA-protein cross-links are presented. The corresponding F37-values for inactivation and production of DNA lesions are significantly increased only at 80 K (factor of 4 to 5). The data indicate that the low temperatures that prevail in the outer parts of the Solar System or at the nightside of Mars or the Moon are not sufficiently low to crucially inhibit inactivation by dehydration. Our data place further constraints on the panspermia hypothesis.

  8. TEMPERATURE INFLUENCE ON THE AGARICUS BISPORUS MUSHROOMS DEHYDRATION PROCESS

    Directory of Open Access Journals (Sweden)

    LILIANA I. MIHALCEA

    2016-12-01

    Full Text Available Edible mushrooms are foods with high nutritional value, delicious and therapeutic products. The main objective of this research was to investigate the influence of different temperatures of the dehydration process on the microstructure and color of Agaricus bisporus mushrooms. Tray drying conditions were: constant air velocity, 50, 60 and 70 °C suited to relative humidity (RH values of 12.17, 4.8 and 2.26 % respectively. Mathematical modeling of drying process, effective moisture diffusivity and activation energy calculations were presented. The effective moisture diffusivity was between (1.09665 – 2.11723·10-10 m2∙s-1 for white and (0.99522 – 1.69885·10-10 m2∙s-1 for brown mushrooms. The activation energy values indicate a higher energy input for the white mushrooms drying. SEM micrographs revealed the overall integrity of the tissue and some hyphae from the stipes of brown and white mushroom appeared intact and similar. At 70 °C, the presence of these crystals is more emphasis due to calcium.

  9. Role of iron content on serpentinite dehydration depth in subduction zones: Experiments and thermodynamic modeling

    Science.gov (United States)

    Merkulova, Margarita; Muñoz, Manuel; Vidal, Olivier; Brunet, Fabrice

    2016-11-01

    A series of dehydration experiments in the piston-cylinder apparatus was carried out at 2 GPa and 550-850 °C on a natural antigorite sample mixed with 5 wt.% of magnetite. Chemical analyses of experimental products show a progressive decrease of the Mg# in antigorite and clinopyroxene between 550 and 675 °C, whereas the Mg# of olivine increases. The observed behavior of Mg# signifies Fe-Mg exchange between coexisting minerals. At higher temperatures, between 700 and 850 °C, compositions remain stable for all minerals in experimental assemblages. Thermodynamic parameters of the ferrous antigorite end-member were refined with the use of Holland and Powell (1998) data set and added to the antigorite solid solution. Good agreement between theoretical calculations performed for the studied bulk composition and experimental results confirms extrapolated thermodynamic data for Fe-antigorite. Constrained parameters allowed to calculate phase relationships for various serpentinite compositions. First, we assessed the effect of bulk iron content, from 0 to 10 wt.% FeO, on the stability field of antigorite. The results show significant decrease of the antigorite thermal stability with increasing bulk Fe content. Second, we demonstrated the influence of bulk iron content on dehydration reactions in subduction zones along typical thermal gradients. Dehydration observed in pure MSH (MgO-SiO2-H2O) systems comprised of antigorite appears as a univariant reaction, which happens at 710 °C/3.7 GPa and 640 °C/6 GPa in "hot" and "cold" subduction, respectively. In contrast, more complex in composition Fe-bearing serpentinites show spread dehydration profiles through divariant reactions from ~ 300 °C/0.8 GPa to 700 °C/3.6 GPa and from 450 °C/4 GPa to 650 °C/7.4 GPa for "hot" and "cold" thermal gradients respectively. A comparison between depths of "water-release events" and "earthquake occurrence" in the South Chile slab ("hot" subduction) highlights a clear correlation between

  10. WATER TEMPERATURE, VOLUNTARY DRINKING AND FLUID BALANCE IN DEHYDRATED TAEKWONDO ATHLETES

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    Saeed Khamnei

    2011-12-01

    Full Text Available Voluntary drinking is one of the major determiners of rehydration, especially as regards exercise or workout in the heat. The present study undertakes to search for the effect of voluntary intake of water with different temperatures on fluid balance in Taekwondo athletes. Six young healthy male Taekwondo athletes were dehydrated by moderate exercise in a chamber with ambient temperature at 38-40°C and relative humidity between 20-30%. On four separate days they were allowed to drink ad libitum plane water with the four temperatures of 5, 16, 26, and 58°C, after dehydration. The volume of voluntary drinking and weight change was measured; then the primary percentage of dehydration, sweat loss, fluid deficit and involuntary dehydration were calculated. Voluntary drinking of water proved to be statistically different in the presented temperatures. Water at 16°C involved the greatest intake, while fluid deficit and involuntary dehydration were the lowest. Intake of water in the 5°C trial significantly correlated with the subject's plasma osmolality change after dehydration, yet it showed no significant correlation with weight loss. In conclusion, by way of achieving more voluntary intake of water and better fluid state, recommending cool water (~16°C for athletes is in order. Unlike the publicly held view, drinking cold water (~5°C does not improve voluntary drinking and hydration status.

  11. The study on the effect of low-temperature heat treatment on tissue dehydration fish pond

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    N. S. Rodionova

    2013-01-01

    Full Text Available The paper is studied thermo-moisture treatment of carp on the provisional application of vacuum packaging. The degree of hydration of the carp meat tissues equally depends on the prepackaging, as well as the characteristics of the fluid in the chamber system. With increasing temperature the degree of hydration of meat carp tissue decreases with the reduction of the difference in its numerical values of packed and unpacked samples. Obtained a graph of depence dependence of the speed of carp meat tissue dehydration of the processing temperature. Revealed that the presence of plastic packaging, as well as wetting fluid help reduce the dehydration speed of carp meat tissues.

  12. Coupled deformation and dehydration processes in smectite-rich sediments constrained by laboratory experiments

    Science.gov (United States)

    Huepers, Andre; Kopf, Achim J.

    2013-04-01

    Subduction zones play a central role in the geological activity of the earth which is expressed as devastating events such as earthquakes, tsunamis and explosive volcanism. Many processes that lead to such catastrophic behavior are driven by fluids, which in turn affect the rock mechanical behavior. The kinetic reaction of hydrous smectite to illite is widely accepted as a fluid source in subduction zone forearcs that also affects the mechanical state of subduction zone sediments. The released fluids are characterized by low-chlorinity and high volatile content. Also, previous workers demonstrated in uniaxial deformation tests that smectite partially dehydrates with increasing effective stress. To shed light on this process we performed uniaxial deformation experiments on smectite-rich samples from the Nankai and Costa Rica subduction zones. Experiments were conducted at temperatures of up to 100°C under constant rate of strain and effective stresses of up to ~100MPa. Fluids expelled during the experiments were analyzed for major and minor element content. The fluids are characterized by fluid-freshening and increasing volatile content that starts at ~1.3MPa effective stress. During the course of the experiments the smectite interlayer water content decreases from 27 wt-% to 20 wt-%. The released interlayer water comprises up to 17% of the total fluid volume released from the consolidating sediment. The onset of fluid freshening is characterized by a change in deformation behavior of the samples. The porosity decrease with increasing effective stress is smaller at effective stresses greater 1.3MPa. We propose that dehydration of the low permeable smectite leads to excess pore pressures in the sample, which causes a load transfer from the solid phase to the pore fluid.

  13. Prediction of water formation temperature in natural gas dehydrators using radial basis function (RBF neural networks

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    Tatar Afshin

    2016-03-01

    Full Text Available Raw natural gases usually contain water. It is very important to remove the water from these gases through dehydration processes due to economic reasons and safety considerations. One of the most important methods for water removal from these gases is using dehydration units which use Triethylene glycol (TEG. The TEG concentration at which all water is removed and dew point characteristics of mixture are two important parameters, which should be taken into account in TEG dehydration system. Hence, developing a reliable and accurate model to predict the performance of such a system seems to be very important in gas engineering operations. This study highlights the use of intelligent modeling techniques such as Multilayer perceptron (MLP and Radial Basis Function Neural Network (RBF-ANN to predict the equilibrium water dew point in a stream of natural gas based on the TEG concentration of stream and contractor temperature. Literature data set used in this study covers temperatures from 10 °C to 80 °C and TEG concentrations from 90.000% to 99.999%. Results showed that both models are accurate in prediction of experimental data and the MLP model gives more accurate predictions compared to RBF model.

  14. User perceptions of urine diversion dehydration toilets: Experiences ...

    African Journals Online (AJOL)

    2013-03-20

    Mar 20, 2013 ... Experiences from a cross-sectional study in eThekwini Municipality. E Roma1,2*, K ... INTRODUCTION. Over recent years concerns have been raised within the global ..... Cultural Acceptability of using Human Excreta (Faeces and Urine) for Food ... and development of a marketing strategy. In: Werner C ...

  15. Temperature and water loss affect ADH activity and gene expression in grape berry during postharvest dehydration.

    Science.gov (United States)

    Cirilli, Marco; Bellincontro, Andrea; De Santis, Diana; Botondi, Rinaldo; Colao, Maria Chiara; Muleo, Rosario; Mencarelli, Fabio

    2012-05-01

    Clusters of Aleatico wine grape were picked at 18°Brix and placed at 10, 20, or 30°C, 45% relative humidity (RH) and 1.5m/s of air flow to dehydrate the berries up to 40% of loss of initial fresh weight. Sampling was done at 0%, 10%, 20%, 30%, and 40% weight loss (wl). ADH (alcohol dehydrogenase) gene expression, enzyme activity, and related metabolites were analysed. At 10°C, acetaldehyde increased rapidly and then declined, while ethanol continued to rise. At 20°C, acetaldehyde and ethanol increased significantly with the same pattern and declined at 40%wl. At 30°C, acetaldehyde did not increase but ethanol increased rapidly already at 10%wl. At the latter temperature, a significant increase in acetic acid and ethyl acetate occurred, while at 10°C their values were low. At 30°C, the ADH activity (ethanol to acetaldehyde direction), increased rapidly but acetaldehyde did not rise because of its oxidation to acetic acid, which increased together with ethyl acetate. At 10°C, the ADH activity increased at 20%wl and continued to rise even at 40%wl, meaning that ethanol oxidation was delayed. At 20°C, the behaviour was intermediate to the other temperatures. The relative expression of the VvAdh2 gene was the highest at 10°C already at 10%wl in a synchrony with the ADH activity, indicating a rapid response likely due to low temperature. The expression subsequently declined. At 20 and 30°C, the expression was lower and increased slightly during dehydration in combination with the ADH activity. This imbalance between gene expression and ADH activity at 10°C, as well as the unexpected expression of the carotenoid cleavage dioxygenase 1 (CCD1) gene, opens the discussion on the stress sensitivity and transcription event during postharvest dehydration, and the importance of carefully monitoring temperature during dehydration.

  16. The oatmeal nematode Panagrellus redivivus survives moderately low temperatures by freezing tolerance and cryoprotective dehydration.

    Science.gov (United States)

    Hayashi, Masakazu; Wharton, David A

    2011-04-01

    The cold tolerance abilities of only a few nematode species have been determined. This study shows that the oatmeal nematode, Panagrellus redivivus, has modest cold tolerance with a 50% survival temperature (S (50)) of -2.5°C after cooling at 0.5°C min(-1) and freezing for 1 h. It can survive low temperatures by freezing tolerance and cryoprotective dehydration; although freezing tolerance appears to be the dominant strategy. Freezing survival is enhanced by low temperature acclimation (7 days at 5°C), with the S (50) being lowered by a small but significant amount (0.42°C). There is no cold shock or rapid cold hardening response under the conditions tested. Cryoprotective dehydration enhances the ability to survive freezing (the S (50) is lowered by 0.55°C, compared to the control, after 4 h freezing at -1°C) and this effect is in addition to that produced by acclimation. Breeding from survivors of a freezing stress did not enhance the ability to survive freezing. The cold tolerance abilities of this nematode are modest, but sufficient to enable it to survive in the cold temperate environments it inhabits.

  17. Kinetics of color change of osmotically dehydrated chub mackerel (Scomber japonicus during storage at different temperatures

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    Gerardo CHECMAREV

    2016-01-01

    Full Text Available Abstract The aim of this study was to determine the effect of storage temperature on the kinetics of color change of chub mackerel dehydrated in a ternary solution (water, glycerol and salt and vacuum packaged in films. The color of processed fish can change because of lipids and protein oxidation during storage. Samples were stored at 7, 25 and 35 °C for seven months and kinetic models of 0, 1 and 2 order were applied to describe the color changes. It was observed that an increase in the storage temperature improved the changes in the CIE color values (L*, a* and b*. First-order reaction had the best statistical parameters for a* at the three temperatures tested. The temperature dependence of parameter a* indicated an Arrhenius relationship and the activation energy (Ea was 44.33 kJ/mol. The parameter b* fitted to the proposed models only in samples stored at 35 °C. The L* value decreased during storage at 25 and 35 °C (pale to dark. Storage at refrigeration temperature (7 °C minimized the color changes.

  18. Dehydration of Traditional Dried Instant Noodle (Mee Siput) Using Controlled Temperature & Humidity Dryer

    Science.gov (United States)

    Mamat, K. A.; Yusof, M. S.; Yusoff, Wan Fauziah Wan; Zulafif Rahim, M.; Hassan, S.; Rahman, M. Qusyairi. A.; Karim, M. A. Abd

    2017-05-01

    Drying process is an essential step to produce instant noodles. Yet, the industries especially Small and Medium Enterprises (SMEs), is seeking for an efficient method to dry the noodles. This paper discusses the performance of an invented drying system which employed heating and humidifying process. The drying system was tested using 30 kilogram of the raw noodle known as “Mee Siput”. Temperature controlled system were used in the study to control the temperature of the drying process and prevent the dried noodles from damage by maintaining the temperature of lower than 80°C. The analysis shows that the system was drastically decreased the humidity from 80% to 40% just after 200 minutes of the drying process. The complete dehydration time of noodle has also decreased to only 4 hours from 16 hours when using traditional drying system without sacrificed the good quality of the dried noodle. In overall, the invented system believed to increase the production capacity of the noodle, reduce cost of production which would highly beneficial for Small Medium Industries (SMEs) in Malaysia.

  19. Dehydration, temperature, and light tolerance in members of the aeroterrestrial green algal genus Interfilum (Streptophyta) from biogeographically different temperate soils

    Science.gov (United States)

    Karsten, Ulf; Herburger, Klaus; Holzinger, Andreas

    2014-01-01

    Unicellular green algae of the genus Interfilum (Klebsormidiales, Streptophyta) are typical components of biological soil crusts. Four different aeroterrestrial Interfilum strains that have previously been molecular-taxonomically characterized and isolated from temperate soils in Belgium, Czech Republic, New Zealand, and Ukraine were investigated. Photosynthetic performance was evaluated under different controlled abiotic conditions, including dehydration, as well as under a light and temperature gradient. For standardized desiccation experiments, a new methodological approach with silica gel filled polystyrol boxes and effective quantum yield measurements from the outside were successfully applied. All Interfilum isolates showed a decrease and inhibition of the effective quantum yield under this treatment, however with different kinetics. While the single cell strains exhibited relatively fast inhibition, the cell packet forming isolates dried slower. Most strains fully recovered effective quantum yield after rehydration. All Interfilum isolates exhibited optimum photosynthesis at low photon fluence rates, but with no indication of photoinhibition under high light conditions suggesting flexible acclimation mechanisms of the photosynthetic machinery. Photosynthesis under lower temperatures was generally more active than respiration, while the opposite was true for higher temperatures. The presented data provide an explanation for the regular occurrence of Interfilum species in soil habitats where environmental factors can be particularly harsh. PMID:25810561

  20. Characterization and Thermal Dehydration Kinetics of Highly Crystalline Mcallisterite, Synthesized at Low Temperatures

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    Emek Moroydor Derun

    2014-01-01

    Full Text Available The hydrothermal synthesis of a mcallisterite (Mg2(B6O7(OH62·9(H2O mineral at low temperatures was characterized. For this purpose, several reaction temperatures (0–70°C and reaction times (30–240 min were studied. Synthesized minerals were subjected to X-ray diffraction (XRD, fourier transform infrared (FT-IR, and Raman spectroscopies and scanning electron microscopy (SEM. Additionally, experimental analyses of boron trioxide (B2O3 content and reaction yields were performed. Furthermore, thermal gravimetry and differential thermal analysis (TG/DTA were used for the determination of thermal dehydration kinetics. According to the XRD results, mcallisterite, which has a powder diffraction file (pdf number of “01-070-1902,” was formed under certain reaction parameters. Pure crystalline mcallisterite had diagnostic FT-IR and Raman vibration peaks and according to the SEM analysis, for the minerals which were synthesized at 60°C and 30 min of reaction time, particle size was between 398.30 and 700.06 nm. Its B2O3 content and reaction yield were 50.80±1.12% and 85.80±0.61%, respectively. Finally, average activation energies (conversion values (α that were selected between 0.1 and 0.6 were calculated as 100.40 kJ/mol and 98.31 kJ/mol according to Ozawa and Kissinger-Akahira-Sunose (KAS methods, respectively.

  1. ETHANOL DEHYDRATION IN PACKED DISTILLATION COLUMN USING GLYCEROL AS ENTRAINER: EXPERIMENTS AND HETP EVALUATION

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    W. L. R. Souza

    Full Text Available Abstract The ethanol-water separation is very important because ethanol is widely applied in the chemical industry and its use as a fuel can reduce the pollution emitted to the air. However, anhydrous ethanol production using conventional distillation is impossible, at atmospheric pressure, due to the presence of an azeotrope. In the present work, experimental tests were carried out in order to evaluate the use of glycerol as an entrainer, in substitution of ethylene glycol in an extractive distillation. The use of glycerol is motivated by the biodiesel production units, due to the fact that it is the main byproduct and a new market is necessary to consume its overproduction. The experiments were carried out in a distillation column packed with Raschig rings, varying the glycerol/feed (ethanol and water ratio, S/F, from 0.5 to 0.9. The samples were analyzed using a digital densimeter. The results showed that glycerol was effective to promote ethanol dehydration and the presence of an azeotrope was not observed using a solvent to feed ratio (S/F equal to 0.9. Some empirical correlations were investigated to evaluate the HETP (Height Equivalent to a Theoretical Plate, and the results provided a useful tool for designing a packed bed column for ethanol-water separation.

  2. In situ phase separation following dehydration in bimetallic sulfates: a variable-temperature X-ray diffraction study.

    Science.gov (United States)

    Swain, Diptikanta; Guru Row, Tayur N

    2009-08-03

    Phase separation resulting in a single-crystal-single-crystal transition accompanied by a polycrystalline phase following the dehydration of hydrated bimetallic sulfates [Na(2)Mn(1.167)(SO(4))(2)S(0.33)O(1.167) x 2 H(2)O and K(4)Cd(3)(SO(4))(5) x 3 H(2)O] has been investigated by in situ variable-temperature single-crystal X-ray diffraction. With two examples, we illustrate the possibility of generating structural frameworks following dehydration in bimetallic sulfates, which refer to the possible precursor phases at that temperature leading to the mineral formation. The room-temperature structure of Na(2)Mn(1.167)(SO(4))(2)S(0.33)O(1.167) x 2 H(2)O is trigonal, space group R3. On heating the crystal in situ on the diffractometer, the diffraction images display spherical spots and concentric rings suggesting phase separation, with the spherical spots getting indexed in a monoclinic space group, C2/c. The structure determination based on this data suggests the formation of Na(2)Mn(SO(4))(2). However, the diffraction images from concentric rings could not be indexed. In the second example, the room-temperature structure is determined to be K(4)Cd(3)(SO(4))(5) x 3 H(2)O, crystallizing in a monoclinic space group, P2(1)/n. On heating the crystal in situ, the diffraction images collected also have both spherical spots and diffuse rings. The spherical spots could be indexed to a cubic crystal system, space group P2(1)3, and the structure is K(2)Cd(2)(SO(4))(3). The possible mechanism for the phase transition in the dehydration regime resulting in this remarkable single-crystal to single-crystal transition with the appearance of a surrogate polycrystalline phase is proposed.

  3. Clinical Experience: Using Dehydrated Human Amnion/Chorion Membrane Allografts for Acute and Reconstructive Burn Care.

    Science.gov (United States)

    Reilly, Debra Ann; Hickey, Sean; Glat, Paul; Lineaweaver, William C; Goverman, Jeremy

    2017-02-01

    Amniotic membrane is immunologically privileged and is a reservoir of growth factors and cytokines known to modulate inflammation and enhance the healing process, while also possessing antimicrobial, antifibrosis, and antiscarring properties. These properties establish a strong argument for using amniotic membrane derived products as a treatment for burns. The purpose of this article is to describe the use of commercially available dehydrated human amnion/chorion membrane allografts in patients with partial-thickness and full-thickness burns.

  4. EFFECT OF TEMPERATURE DISTRIBUTION ON PREDICTING QUALITY OF MICROWAVE DEHYDRATED FOOD

    Directory of Open Access Journals (Sweden)

    Mohammad U. H. Joardder

    2013-12-01

    Full Text Available During food drying, many other changes occur simultaneously, resulting in an improved overall quality. Among the quality attributes, the structure and its corresponding color influence directly or indirectly other properties of food. In addition, these quality attributes are affected by process conditions, material components and the raw structure of the foodstuff. In this work, the temperature distribution within food materials during microwave drying has been taken into consideration to observe its role in color modification. In order to determine the temperature distribution of microwave-dried food (apple, a thermal imaging camera has been used. The image acquired from the digital camera has been analysed using image J software in order to get the color change of fresh and dried apple. The results show that temperature distribution plays an important role in determining the quality of the food. The thermal imaging camera was deployed to observe the temperature distribution within food materials during drying. It is clearly observed from the higher value of (ERGB =102 and the uneven color change that uneven temperature distribution can influence customer perceptions of the quality of dried food. Simulation of a mathematical model of temperature distribution during microwave drying can make it possible to predict the colour and texture of the microwaved food.

  5. Influence of Distillation Temperature in the Determination of Added Sulfites in Dehydrated Garlic Powders Using the Modified Optimized Monier-Williams Method.

    Science.gov (United States)

    2016-04-08

    Influence of distillation temperature on the determination of added sulfites in dehydrated garlic originating from China and California using the modified optimized Monier-Williams method was evaluated. In the study, the temperature of the distillation was monitored and maintained from 90° to 95°C instead of boiling temperature (>95°C). Samples from 38 unsulfited dehydrated garlic powders were analyzed at the 90° to 95°C temperature and at boiling temperature (>95°C) at 94 m above sea level. At the boiling distillation temperature, 25 of the 38 unsulfited garlic samples had a positive result for sulfite content ranging from 10.2 to 14.1 ppm using the modified optimized Monier-Williams procedure. Maintaining distillation temperature between 90° and 95°C eliminated false-positive results for added sulfite and had an average spiked sulfite recovery of 95.6% with a coefficient of variation of 3.79%. Lowering of the distillation temperature decreases the possible acid hydrolysis of organosulfur compounds that can lead to positive added sulfite results in unsulfited dehydrated garlic samples.

  6. Responses of the bed bug, Cimex lectularius, to temperature extremes and dehydration: levels of tolerance, rapid cold hardening and expression of heat shock proteins.

    Science.gov (United States)

    Benoit, J B; Lopez-Martinez, G; Teets, N M; Phillips, S A; Denlinger, D L

    2009-12-01

    This study of the bed bug, Cimex lectularius, examines tolerance of adult females to extremes in temperature and loss of body water. Although the supercooling point (SCP) of the bed bugs was approximately -20 degrees C, all were killed by a direct 1 h exposure to -16 degrees C. Thus, this species cannot tolerate freezing and is killed at temperatures well above its SCP. Neither cold acclimation at 4 degrees C for 2 weeks nor dehydration (15% loss of water content) enhanced cold tolerance. However, bed bugs have the capacity for rapid cold hardening, i.e. a 1-h exposure to 0 degrees C improved their subsequent tolerance of -14 and -16 degrees C. In response to heat stress, fewer than 20% of the bugs survived a 1-h exposure to 46 degrees C, and nearly all were killed at 48 degrees C. Dehydration, heat acclimation at 30 degrees C for 2 weeks and rapid heat hardening at 37 degrees C for 1 h all failed to improve heat tolerance. Expression of the mRNAs encoding two heat shock proteins (Hsps), Hsp70 and Hsp90, was elevated in response to heat stress, cold stress and during dehydration and rehydration. The response of Hsp90 was more pronounced than that of Hsp70 during dehydration and rehydration. Our results define the tolerance limits for bed bugs to these commonly encountered stresses of temperature and low humidity and indicate a role for Hsps in responding to these stresses.

  7. Effect of vacuum impregnation temperature on the mechanical properties and osmotic dehydration parameters of apples

    OpenAIRE

    Sabrina Silva Paes; Gustavo Beulke Stringari; João Borges Laurindo

    2008-01-01

    The effect of sucrose solution temperature on the mechanical properties, water loss (WL), solids gain (SG) and weight reduction (WR) of apples (Fuji var.) treated by vacuum impregnation was studied. Temperatures were varied from 10 to 50 ºC, using a sucrose solution of 50 ºBrix. The mechanical properties were studied throughout a stress relaxation test. The results showed that the SG varied between 10.57 and 14.29 % and the WL varied between 10.55 and 14.48 %. The treated fruit soluble solids...

  8. Effect of vacuum impregnation temperature on the mechanical properties and osmotic dehydration parameters of apples

    Directory of Open Access Journals (Sweden)

    Sabrina Silva Paes

    2008-08-01

    Full Text Available The effect of sucrose solution temperature on the mechanical properties, water loss (WL, solids gain (SG and weight reduction (WR of apples (Fuji var. treated by vacuum impregnation was studied. Temperatures were varied from 10 to 50 ºC, using a sucrose solution of 50 ºBrix. The mechanical properties were studied throughout a stress relaxation test. The results showed that the SG varied between 10.57 and 14.29 % and the WL varied between 10.55 and 14.48 %. The treated fruit soluble solids increased with the temperature probably due to the lower viscosity of the solution. The maximum stress was highest at 10 ºC, decreasing at higher temperatures, probably due the softening of the structure.A impregnação a vácuo (VI de alimentos é realizada pela aplicação de vácuo em um tanque contendo o produto imerso em uma solução, seguida da recuperação da pressão atmosférica. Neste trabalho, estudou-se o efeito da temperatura da solução de sacarose nas propriedades mecânicas das amostras e na perda de água (WL, ganho de sólidos (SG e redução de peso (WR. A faixa de temperaturas estudada foi de 10 a 50 ºC, usando uma solução de sacarose com 50 ºBrix. As propriedades mecânicas das amostras foram estudadas através de ensaios mecânicos de deformação-relaxação. O SG variou entre 10.57 e 14.29 %, enquanto WL variou entre 10.55 e 14.48 %. O teor de sólidos das frutas tratadas aumentou com a temperatura, provavelmente devido à diminuição da viscosidade da solução. A tensão máxima foi maior a 10 ºC, diminuindo com a temperatura, devido ao amolecimento da estrutura.

  9. EFFECT OF PRE-TREATMENTS ON PHYSICO-CHEMICAL COMPOSITION OF DEHYDRATED JACKFRUIT CHIPS DURING STORAGE AT AMBIENT TEMPERATURE

    Directory of Open Access Journals (Sweden)

    ROHAN R. PATIL, MANDAR KHANVILKAR, D. N. MOKAT*, P. P. RELEKAR AND R K. H. PUJARI

    2014-08-01

    The dehydrated chips of jackfruit pre-treated with ascorbic acid (T4 recorded maximum mean score for colour, flavour and texture irrespective of storage period. The organoleptic scores of these dehydrated jackfruit chips for all above attributes were declined with the increase in storage period from 0 to 60 days. The dehydrated chips pre-treated with ascorbic acid (T4 recorded maximum overall acceptability score of 6.91 at 60 days of storage which clearly indicated its suitability for making good quality chips and also for storing them for 60 days at ambient conditions without much loss of sensory and nutritional qualities of chips.Keywords: Physico chemical composition of dehydrated chips of jackfruit (Artocarpus heterophyllus and storage period.

  10. Effect of Calcination Temperatures and Mo Modification on Nanocrystalline (γ-χ-Al2O3 Catalysts for Catalytic Ethanol Dehydration

    Directory of Open Access Journals (Sweden)

    Tharmmanoon Inmanee

    2017-01-01

    Full Text Available The mixed gamma and chi crystalline phase alumina (M-Al catalysts prepared by the solvothermal method were investigated for catalytic ethanol dehydration. The effects of calcination temperatures and Mo modification were elucidated. The catalysts were characterized by X-ray diffraction (XRD, N2 physisorption, transmission electron microscopy (TEM, and NH3-temperature programmed desorption (NH3-TPD. The catalytic activity was tested for ethylene production by dehydration reaction of ethanol in gas phase at atmospheric pressure and temperature between 200°C and 400°C. It was found that the calcination temperatures and Mo modification have effects on acidity of the catalysts. The increase in calcination temperature resulted in decreased acidity, while the Mo modification on the mixed phase alumina catalyst yielded increased acidity, especially in medium to strong acids. In this study, the catalytic activity of ethanol dehydration to ethylene apparently depends on the medium to strong acid. The mixed phase alumina catalyst calcined at 600°C (M-Al-600 exhibits the complete ethanol conversion having ethylene yield of 98.8% (at 350°C and the Mo-modified catalysts promoted dehydrogenation reaction to acetaldehyde. This can be attributed to the enhancement of medium to strong acid with metal sites of catalyst.

  11. Evaluation of superabsorbent efficiency in response to dehydration frequencies, salinity and temperature and its effect on yield and quality of cotton under deficit irrigation

    Directory of Open Access Journals (Sweden)

    Hamid-Reza Fallahi

    2016-03-01

    Full Text Available Introduction Reduced availability of water resources in many arid countries including Iran, particularly in response to the indiscriminate harvesting of water reservoirs and climate change, has created concerns. Therefore, the sustainable use of water resources especially in agriculture is a necessity for these countries. Strategies such as deficit irrigation and superabsorbent application are two important ways for improving water use efficiency in agricultural lands. In deficit irrigation the crop must be irrigated less than its required water. Therefore, some reduction may occur in crop yield, but the savings in water will improve the water use efficiency (Akbari Nodehi, 2011. Superabsorbent polymers also increase the nutrients and water holding capacity of soil for a long time and thereby reduce crop water requirement. However, the effectiveness of these materials could be affected by dehydration frequencies, temperature and irrigation water quality (Karimi et al., 2009. Due to the limitation of water resources in many parts of Iran, the aim of this study was to investigate the possibility of cotton production under deficit irrigation along with application of different rates of superabsorbent. In addition, simulation of superabsorbent efficiency at different levels of salinity, temperature and dehydration frequencies (swelling and de-swelling were the other objectives in this study. Materials and methods 1. Laboratory experiments In these experiments the effects of temperature (4, 10, 20, 30 and 40 °C, salinity (0, 0.25, 0.5, 0.75 and 1% NaCl solutions at two temperatures of 10 and 25°C and frequency of partial dehydration (from 1 to 5 stages watering and 70% dewatering were simulated on water absorption capacity of superabsorbent polymer at laboratory of environmental stresses, Sarayan Faculty of Agriculture, Birjand University. 2- Field experiment This experiment was designed at Research Station of Sarayan Faculty of Agriculture

  12. Effect of leaf dehydration duration and dehydration degree on PSII photochemical activity of papaya leaves.

    Science.gov (United States)

    Liu, Meijun; Zhang, Zishan; Gao, Huiyuan; Yang, Cheng; Fan, Xingli; Cheng, Dandan

    2014-09-01

    Although the effect of dehydration on photosynthetic apparatus has been widely studied, the respective effect of dehydration duration and dehydration degree was neglected. This study showed that, when leaves dehydrated in air, the PSII activities of leaves decreased with the decline of leaf relative water content (RWC). Unexpectedly, when leaves dehydrated to same RWC, the decreases in Fv/Fm, Ψo and RC/CSm were lower in leaves dehydrating at 43 °C than those at 25 °C. However, to reach the same RWC, leaves dehydrating at 43 °C experienced 1/6 of the dehydration duration for leaves dehydrating at 25 °C. To distinguish the respective effect of dehydration degree and dehydration duration on photosynthetic apparatus, we studied the PSII activities of leaves treated with different concentration of PEG solutions. Increasing dehydration degree aggravated the decline of Fv/Fm, Ψo and RC/CSm in leaves with the same dehydration duration, while prolonging the dehydration duration also exacerbated the decline of Fv/Fm, Ψo and RC/CSm in leaves with identical dehydration degree. With the same dehydration degree and duration, high temperature enhanced the decrease of Fv/Fm, Ψo and RC/CSm in the leaves. When leaves dehydrated in air, the effect of high temperature was underestimated due to reduction of dehydration duration. The results demonstrated that, dehydration degree and duration both play important roles in damage to photosynthetic apparatus. We suggest that, under combined stresses, the effects of dehydration degree and duration on plants should be considered comprehensively, otherwise, partial or incorrect results may be obtained.

  13. Fruits and vegetables dehydration

    Science.gov (United States)

    de Ita, A.; Flores, G.; Franco, F.

    2015-01-01

    Dehydration diagrams were determined by means of Differential Thermal Analysis, DTA, and Thermo Gravimetric Analysis, TGA, curves of several simultaneous fruits and vegetables, all under the same conditions. The greater mass loss is associated with water containing in the structure of the investigated materials at low temperature. In poblano chile water is lost in a single step. The banana shows a very sharply two stages, while jicama can be observed although with a little difficulty three stages. The major mass loss occurs in the poblano chile and the lower in banana. The velocity and temperature of dehydration vary within a small range for most materials investigated, except for banana and cactus how are very different.

  14. Thermal dehydration kinetics of phosphogypsum

    Directory of Open Access Journals (Sweden)

    López, F. A.

    2015-09-01

    Full Text Available Phsophogypsum is a by-product from the processing phosphate rock. Before the use of it in cement industry such as setting regulator is necessary a study of dehydration reaction of phosphogypsum to avoid the false setting during the milling. The aim is to study the thermal behavior of two different phosphogypsum sources (Spain and Tunisia under non-isothermal conditions in argon atmosphere by using Thermo-Gravimetriy, Differential Thermal Analysis (TG-DTA and Differential Scanning Calorimetry (DSC. DSC experiments were carried out at temperatures ranging from ambient to 350 °C at different heating rates. The temperatures of conversion from gypsum to hemihydrate and anhydrite states and heat of dehydration were determined. Various methods were used to analyze the DSC data for reaction kinetics determination. The activation energy and frequency factor were calculated for dehydration of phosphogypsum. Activation energy values of the main dehydration reaction of phosphogypsum were calculated to be approximately 61–118 kJ/mol.El fosfoyeso es un subproducto procedente del procesado de la roca fosfato. Una de las posibles vías de reutilización y revalorización es su uso como regulador del fraguado en la industria cementera. Debido a los posibles problemas de falso fraguado asociado a los procesos de deshidratación que tienen lugar durante la molienda del cemento, esta investigación estudió el comportamiento térmico, bajo condiciones no-isotérmicas en atmósfera de argón, de dos fosfoyesos, mediante TG-DTA y DSC. Los ensayos de DSC se realizaron hasta los 350 °C a diferentes velocidades de calentamiento. La temperatura de conversión del yeso a las formas de hemihidrato y anhidrita y el calor de hidratación fueron determinados. Las cinéticas de reacción fueron obtenidas analizando los datos de DSC mediante varios métodos. Se calculó la energía de activación y el factor de frecuencia para las reacciones de deshidratación del

  15. In situ dehydration of yugawaralite

    DEFF Research Database (Denmark)

    Artioli, G.; Ståhl, Kenny; Cruciani, G.;

    2001-01-01

    The structural response of the natural zeolite yugawaralite (CaAl2Si6O16. 4H(2)O) upon thermally induced dehydration has been studied by Rietveld analysis of temperature-resolved powder diffraction data collected in situ in the temperature range 315-791 K using synchrotron radiation. The room-tem...

  16. Influence of environmental conditions on the kinetics and mechanism of dehydration of carbamazepine dihydrate.

    Science.gov (United States)

    Han, J; Suryanarayanan, R

    1998-11-01

    The object of this project was to study the influence of temperature and water vapor pressure on the kinetics and mechanism of dehydration of carbamazepine dihydrate and to establish the relationship between the dehydration mechanism and the solid-state of the anhydrous phase formed. Three experimental techniques were utilized to study the kinetics of dehydration of carbamazepine dihydrate (C15H12N2O.2H2O)-thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and variable temperature powder X-ray diffractometry (VTXRD). These techniques respectively provide information about the changes in weight, heat flow and solid-state (phase) during the dehydration process. The instrumental setup was modified so that simultaneous control of both the temperature and the water vapor pressure was possible. The experiments were carried out at different temperatures, ranging from 26 to 64 degrees C. In the absence of water vapor, the dehydration followed the 2-dimensional phase boundary controlled model at all the temperatures studied. In the next stage, the water vapor pressure was altered while the studies were carried out at a single temperature of 44 degrees C. The dehydration was 2-dimensional phase boundary controlled at water vapor pressures or = 12.0 torr. In the former case, the anhydrous phase formed was X-ray amorphous while it was the crystalline anhydrous gamma-carbamazepine in the latter. Thus a relationship between the mechanism of dehydration and the solid-state of the product phase was evident. The dehydration conditions influence not only the mechanism but also the solid-state of the anhydrous phase formed. While the techniques of TGA and DSC have found extensive use in studying dehydration reactions, VTXRD proved to be an excellent complement in characterizing the solid-states of the reactant and product phases.

  17. Thermal Dehydration Kinetics of Gypsum and Borogypsum under Non-isothermal Conditions

    Institute of Scientific and Technical Information of China (English)

    I.Y.Elbeyli; S.Piskin

    2004-01-01

    Thermal dehydration of gypsum and borogypsum was investigated under nonisothermal conditions in air by using simultaneous thermogravimetric-differential thermal analyzer. Nonisothermal experiments were carried out at various linear heating rates. Kinetics of dehydration in the temperature range of 373-503 K were evaluated from the DTA (differential thermal analysis)-TGA (thermogravimetric analysis) data by means of Coats-Redfern,Kissinger and Doyle Equations. Values of the activation energy and the pre-exponential factor of the dehydration were calculated. The results of thermal experiments and kinetic parameters indicated that borogypsum is similar to gypsum from dehydration mechanism point of view although it consists of boron and small amount of alkali metal oxides.

  18. Similarity Theory of Withdrawn Water Temperature Experiment

    Directory of Open Access Journals (Sweden)

    Yunpeng Han

    2015-01-01

    Full Text Available Selective withdrawal from a thermal stratified reservoir has been widely utilized in managing reservoir water withdrawal. Besides theoretical analysis and numerical simulation, model test was also necessary in studying the temperature of withdrawn water. However, information on the similarity theory of the withdrawn water temperature model remains lacking. Considering flow features of selective withdrawal, the similarity theory of the withdrawn water temperature model was analyzed theoretically based on the modification of governing equations, the Boussinesq approximation, and some simplifications. The similarity conditions between the model and the prototype were suggested. The conversion of withdrawn water temperature between the model and the prototype was proposed. Meanwhile, the fundamental theory of temperature distribution conversion was firstly proposed, which could significantly improve the experiment efficiency when the basic temperature of the model was different from the prototype. Based on the similarity theory, an experiment was performed on the withdrawn water temperature which was verified by numerical method.

  19. Numerical simulations of temperature, dehydration, and flow fields associated with subduction of the Cocos plate, and its relation to the occurrence of interplate seismic events in southern Mexico

    Science.gov (United States)

    Suenaga, N.; Ji, Y.; Yoshioka, S.; Manea, M.; Manea, V. C.

    2016-12-01

    In southern Mexico, tectonic tremors mainly occur in the "flat slab region, and the last three SSEs in southern Mexico occurred in the shallower region. Besides, there are two seismic gaps of megathrust earthquakes in Guerrero and Oaxaca. To investigate generation mechanisms of megathrust earthquakes, tectonic tremors, and slow slip events (SSEs) in southern Mexico, we performed three-dimensional numerical simulations of temperature and mantle flow associated with subduction of the Cocos plate, and estimated dehydrated water content from the subducting plate. Here we considered retreat of the Middle American trench initiating about 16 Ma as one of the generation mechanisms of the slab flattening. In our model, we introduced the trench retreat effect during only a certain period between 16 Ma and present in order to best fit the observed heat flow data (from Global Heat Flow Database) as well as Curie point depths defined by the 580 ° isotherm. Our preliminary results show that trench rollback has a strong influence on temperature distribution. Models with trench rollback induce a weaker mantle wedge convection cell compared with models with stationary trench. Other parameter that is currently investigated in this study is the rate of trench retreat.

  20. The independent influences of heat strain and dehydration upon cognition.

    Science.gov (United States)

    van den Heuvel, Anne M J; Haberley, Benjamin J; Hoyle, David J R; Taylor, Nigel A S; Croft, Rodney J

    2017-05-01

    Many researchers have addressed the potential effects of hyperthermia and dehydration on cognition, often revealing contradictory outcomes. A possible reason for this inconsistency is that experiments may have been inadequately designed for such effects. In this study, the impact of hyperthermia, dehydration and their combination on cognition were evaluated in eight young males, after accounting for a range of experimental limitations. Passive heating and thermal clamping at two mean body temperatures (36.5, 38.5 °C) were performed under three hydration states (euhydrated, 3 and 5% dehydrated) to assess their effects on difficulty-matched working memory and visual perception tasks, and on a difficulty manipulated perceptual task. Data were analysed according to signal detection theory to isolate changes in response sensitivity, bias and speed. Neither moderate hyperthermia (P = 0.141) nor dehydration (P > 0.604) modified response sensitivity, nor did they significantly interact (P > 0.698). Therefore, the ability to distinguish correct from incorrect responses was unaffected. Nevertheless, hyperthermia, but not dehydration (P = 0.301), reduced the response bias (-0.08 versus 2.2 [normothermia]; P = 0.010) and reaction time (mean reduction 49 ms; P liberal and faster responses (P = 0.010). Response bias was reduced for the memory relative to the perceptual task (P = 0.037), and this effect was enhanced during hyperthermia (P = 0.031). These observations imply that, once potentially confounding influences were controlled, moderate hyperthermia, significant dehydration and their combined effects had insufficient impact to impair cognition within the memory and perceptual domains tested. Nonetheless, moderate hyperthermia elicited more liberal and rapid responses.

  1. How reaction and permeability develop in dehydrating systems

    Science.gov (United States)

    Leclère, H. J.; Faulkner, D. R.; Wheeler, J.; Bedford, J. D.

    2016-12-01

    The triggering of earthquakes at intermediate-depth along subduction zones is often explained by dehydration reactions, releasing free-water and allowing pore-fluid pressure build-up. During dehydration reactions, pore-fluid pressure is increased when permeability is low enough to prevent fluid escape. Permeability is not constant during dehydration reactions but is rather changed by porosity changes (i.e. solid volume reduction or pore compaction). The evolution of permeability during dehydration reactions will thus dictate the pore-fluid pressure evolution that will affect rock strength and earthquake triggering. However, our understanding on the coupling between permeability, pore-fluid pressure, microstructures, deformation and reaction rate is incomplete. In some cases, the development of reactions is distributed uniformly and permeability increases steadily throughout the reaction progress. In other cases, reactions will not proceed uniformly and nature along with previous experiments indicate that "reaction fronts" develop. On the large scale, reaction rate and fluid pressure evolution depend on the movement of these fronts. Experimental results are presented on permeability and reaction front evolution during gypsum dehydration - an analogue for silicate dehydration. Triaxial experiments were conducted using polycrystalline gypsum cores with very low initial porosity. Pore-fluid pressure is controlled at one end of the sample and monitored at the other in order to measure permeability. Gypsum cores were dehydrated at a constant temperature of 115°C. Two parameter spaces were explored: the pore-fluid pressure (20, 40 or 60 MPa) that influences reaction rate, and effective confining pressure (60 or 110 MPa) that influences pore-compaction. The evolution of permeability, porosity, reaction rate and pore-fluid pressure are measured throughout the reaction. SEM observations of post-mortem samples collected at three key stages during the reaction shows how the

  2. Moving-window 2D correlation spectroscopy in studies of fluphenazine-DPPC dehydrated film as a function of temperature

    Science.gov (United States)

    Szwed, Joanna; Cieślik-Boczula, Katarzyna; Czarnik-Matusewicz, Bogusława; Jaszczyszyn, Agata; Gąsiorowski, Kazimierz; Świątek, Piotr; Malinka, Wiesław

    2010-06-01

    The effect of incorporating fluphenazine (FPh) into the dipalmitoylphosphatidylcholine (DPPC) multibilayers was studied by means of two-dimensional correlation spectroscopy (2DCOS) applied to attenuated total reflection (ATR) infrared spectra. DPPC is used as a model membrane that mimics the organization of lipids in biological membranes and their interaction with FPh. ATR-IR spectra for both DPPC dry film alone and the film doped with FPh were recorded as a function of temperature to provide information about the interaction between FPh molecules and DPPC lipid. The chain-melting phase-transition temperature changes are strictly correlated with the conformational order of the lipid hydrocarbon chains. To gain deeper insight into the accompanying spectral changes, we employed moving-window 2D correlation spectroscopy. Subdividing all the measurements from 10 to 90 °C into 20° subsets enables a detailed identification of spectral features induced by embedding FPh into DPPC multilayers. Moving-window analysis of the power spectra for the ν asym,symCH 2, δ sCH 2, and δ rCH 2 vibrations provides evidence that FPh is embedded in the region between the bilayers, penetrating their hydrophilic part, which destabilizes the interchain interaction. Above 60 °C the FPh-DPPC system reaches the liquid crystalline phase with the well-established location of FPh. A further temperature increase to 90 °C has little effect on the intrachain conformational order and the packing character of the FPh-DPPC system in the liquid crystalline phase. In addition, FPh hinders the formation of large domains. Comparison of the moving-window analysis done by using slice spectra for DPPC and FPh-doped DPPC dry film for ν asym,symCH 2, νC dbnd O, and νPO2- shows that the interaction between the DPPC and FPh molecules is accompanied by very distinct spectral changes located in a both lower and narrower temperature range than those observed in pure DPPC film.

  3. Kinetics of dehydration of potato and development of baked product based on dehydrated potato

    OpenAIRE

    Sarker, A.; M.N. Islam; Shaheb, M.R.

    2012-01-01

    The aims of this study were to determine the kinetics of dehydration of high yielding potato variety (Diamont), to investigate the various process parameters influencing mechanical drying of potatoes and to develop baked product from the dehydrated potato. From the developed equation it was found that the diffusion co-efficient increased with the increase in temperature. The exponential relationship between diffusion co-efficient (De) versus inverse absolute temperature (Tabs-1), activation e...

  4. Relationships among temperature, dehydration of the subducting Philippine Sea plate, and the occurrence of a megathrust earthquake, low-frequency earthquakes, and a slow slip event in the Tokai district, central Japan

    Science.gov (United States)

    Suenaga, Nobuaki; Yoshioka, Shoichi; Matsumoto, Takumi

    2016-11-01

    In this study, we performed two-dimensional numerical simulations of temperature distribution associated with subduction of the Philippine Sea (PHS) plate, and estimated the dehydration process of hydrous mid-ocean-ridge basalt (MORB) in the oceanic crust in the Tokai district, central Japan. We discuss the relationship among temperature, dehydration, and a seismogenic zone of an expected megathrust Tokai earthquake, and the occurrence of a slow slip event (SSE) and deep low-frequency earthquakes (LFEs). The depth range of the seismogenic zone for the megathrust earthquake was estimated to be 8-22 km, narrowing toward the east. The most suitable value of the pore pressure ratio on the plate interface was estimated to be 0.97, indicating minimal frictional heating there. The temperatures of the upper surface of the PHS plate, where the Tokai SSE occurred from 2000 to 2005, were estimated to be 350-450 °C. Therefore, the Tokai SSE is considered to have occurred at the transition zone between unstable and stable sliding. In addition, hydrous MORB was transformed from blueschist into greenschist near the region where the Tokai SSE occurred. The temperatures of the upper surface of the PHS plate, where LFEs occur, were estimated to be 450-500 °C. Therefore, LFEs are considered to occur near the down-dip limit of the transition zone. The amount of dehydration from the oceanic crust of the subducting PHS plate near the region where LFEs are distributed in a belt-like form decreases toward the east with deepening of the hypocenters of the LFEs. Thus, the mechanisms of generation of LFEs in the Tokai district might differ from those in southwest and central Japan where LFEs generally occur at depths between 27 and 35 km. In summary, we consider that the occurrence of LFEs is related to both temperature conditions and dehydration process. However, there is an exceptional area in the eastern part of the Tokai district where the occurrence of LFEs is restricted by

  5. Phases transformation of nickel lateritic ore during dehydration

    Directory of Open Access Journals (Sweden)

    Huang Q.

    2011-01-01

    Full Text Available The high magnesium nickel laterite ore need first be dehydrated if it is treated by the pirometallurgical means. The nickel laterite ore was dehydrated in a laboratory scale sintering pot in this study. The dehydration mechanism was studied by using the thermo-gravimetric (TG tests, differential thermal analysis (DTA, and X-ray diffraction (XRD experiments. The measurements indicated that chlorite (Fe,Mg,Al6(Si,Al4O10(OH8 and serpentine Mg21Si12O28(OH34H2O are the primary phases, while FeO(OH and (Fe,Mg,3Si4O10(OH2 are the minor phases in the ore. The water in the ore can be divided as free water, crystal water, and hydroxyl group. During the heating process, the temperature range for the removal of the free water is 25~140˚C, for the crystal water it is 200~480 ˚C, and for the hydroxyl group it is 500~800˚C. The experiments with various coal dosages show that the temperatures of off-gas and burden increase with an increase in coal dosage. The sinter samples were analyzed using XRD. The results demonstrated that olivine (Mg,Fe2SiO4 and spinel MgFe2O4 are the main bonding phases.

  6. Electrolyte Concentrates Treat Dehydration

    Science.gov (United States)

    2009-01-01

    Wellness Brands Inc. of Boulder, Colorado, exclusively licensed a unique electrolyte concentrate formula developed by Ames Research Center to treat and prevent dehydration in astronauts returning to Earth. Marketed as The Right Stuff, the company's NASA-derived formula is an ideal measure for athletes looking to combat dehydration and boost performance. Wellness Brands also plans to expand with products that make use of the formula's effective hydration properties to help treat conditions including heat stroke, altitude sickness, jet lag, and disease.

  7. Cognitive performance and dehydration.

    Science.gov (United States)

    Adan, Ana

    2012-04-01

    No matter how mild, dehydration is not a desirable condition because there is an imbalance in the homeostatic function of the internal environment. This can adversely affect cognitive performance, not only in groups more vulnerable to dehydration, such as children and the elderly, but also in young adults. However, few studies have examined the impact of mild or moderate dehydration on cognitive performance. This paper reviews the principal findings from studies published to date examining cognitive skills. Being dehydrated by just 2% impairs performance in tasks that require attention, psychomotor, and immediate memory skills, as well as assessment of the subjective state. In contrast, the performance of long-term and working memory tasks and executive functions is more preserved, especially if the cause of dehydration is moderate physical exercise. The lack of consistency in the evidence published to date is largely due to the different methodology applied, and an attempt should be made to standardize methods for future studies. These differences relate to the assessment of cognitive performance, the method used to cause dehydration, and the characteristics of the participants.

  8. Permeability control on transient slip weakening during gypsum dehydration: Implications for earthquakes in subduction zones

    Science.gov (United States)

    Leclère, Henri; Faulkner, Daniel; Wheeler, John; Mariani, Elisabetta

    2016-05-01

    A conflict has emerged from recent laboratory experiments regarding the question of whether or not dehydration reactions can promote unstable slip in subduction zones leading to earthquakes. Although reactions produce mechanical weakening due to pore-fluid pressure increase, this weakening has been associated with both stable and unstable slip. Here, new results monitoring strength, permeability, pore-fluid pressure, reaction progress and microstructural evolution during dehydration reactions are presented to identify the conditions necessary for mechanical instability. Triaxial experiments are conducted using gypsum and a direct shear sample assembly with constant normal stress that allows the measurement of permeability during sliding. Tests are conducted with temperature ramp from 70 to 150 °C and with different effective confining pressures (50, 100 and 150 MPa) and velocities (0.1 and 0.4 μm s-1). Results show that gypsum dehydration to bassanite induces transient stable-slip weakening that is controlled by pore-fluid pressure and permeability evolution. At the onset of dehydration, the low permeability promoted by pore compaction induces pore-fluid pressure build-up and stable slip weakening. The increase of bassanite content during the reaction shows clear evidence of dehydration related with the development of R1 Riedel shears and P foliation planes where bassanite is preferentially localized along these structures. The continued production of bassanite, which is stronger than gypsum, provides a supporting framework for newly formed pores, thus resulting in permeability increase, pore-fluid pressure drop and fault strength increase. After dehydration reaction, deformation is characterized by unstable slip on the fully dehydrated reaction product, controlled by the transition from velocity-strengthening to velocity-weakening behaviour of bassanite at temperature above ∼140 °C and the localization of deformation along narrow Y-shear planes. This study

  9. The Low Temperature Microgravity Physics Experiments Project

    Science.gov (United States)

    Holmes, Warren; Lai, Anthony; Croonquist, Arvid; Chui, Talso; Eraker, J. H.; Abbott, Randy; Mills, Gary; Mohl, James; Craig, James; Balachandra, Balu; hide

    2000-01-01

    The Low Temperature Microgravity Physics Facility (LTMPF) is being developed by NASA to provide long duration low temperature and microgravity environment on the International Space Station (ISS) for performing fundamental physics investigations. Currently, six experiments have been selected for flight definition studies. More will be selected in a two-year cycle, through NASA Research Announcement. This program is managed under the Low Temperature Microgravity Physics Experiments Project Office at the Jet Propulsion Laboratory. The facility is being designed to launch and returned to earth on a variety of vehicles including the HII-A and the space shuttle. On orbit, the facility will be connected to the Exposed Facility on the Japanese Experiment Module, Kibo. Features of the facility include a cryostat capable of maintaining super-fluid helium at a temperature of 1.4 K for 5 months, resistance thermometer bridges, multi-stage thermal isolation system, thermometers capable of pico-Kelvin resolution, DC SQUID magnetometers, passive vibration isolation, and magnetic shields with a shielding factor of 80dB. The electronics and software architecture incorporates two VME buses run using the VxWorks operating system. Technically challenging areas in the design effort include the following: 1) A long cryogen life that survives several launch and test cycles without the need to replace support straps for the helium tank. 2) The minimization of heat generation in the sample stage caused by launch vibration 3) The design of compact and lightweight DC SQUID electronics. 4) The minimization of RF interference for the measurement of heat at pico-Watt level. 5) Light weighting of the magnetic shields. 6) Implementation of a modular and flexible electronics and software architecture. The first launch is scheduled for mid-2003, on an H-IIA Rocket Transfer Vehicle, out of the Tanegashima Space Center of Japan. Two identical facilities will be built. While one facility is onboard

  10. Production of Clean Transportation Fuel Dimethylether by Dehydration of Methanol Over Nafion Catalyst

    OpenAIRE

    Varışlı, Dilek; Doğu, Timur

    2010-01-01

    Dimethylether (DME) which is a very attractive synthetic transportation fuel alternate is synthesized by the dehydration reaction of methanol over nafion as the catalyst. The objective is to test the activity of this catalyst in methanol dehydration reaction. Experiments carried out in a vapor phase flow reactor in a temperature range of 120-220oC and with a space time of 1.35 s.g/cm3 showed quite high activity of Nafion to produce DME, giving conversion values of about 0.4 at 220oC. An incre...

  11. Dehydration and cognitive performance.

    Science.gov (United States)

    Grandjean, Ann C; Grandjean, Nicole R

    2007-10-01

    Human neuropsychology investigates brain-behavior relationships, using objective tools (neurological tests) to tie the biological and behavior aspects together. The use of neuropsychological assessment tools in assessing potential effects of dehydration is a natural progression of the scientific pursuit to understand the physical and mental ramifications of dehydration. It has long been known that dehydration negatively affects physical performance. Examining the effects of hydration status on cognitive function is a relatively new area of research, resulting in part from our increased understanding of hydration's impact on physical performance and advances in the discipline of cognitive neuropsychology. The available research in this area, albeit sparse, indicates that decrements in physical, visuomotor, psychomotor, and cognitive performance can occur when 2% or more of body weight is lost due to water restriction, heat, and/or physical exertion. Additional research is needed, especially studies designed to reduce, if not remove, the limitations of studies conducted to date.

  12. High temperature superconductivity space experiment (HTSSE)

    Science.gov (United States)

    Ritter, J. C.; Nisenoff, M.; Price, G.; Wolf, S. A.

    1991-01-01

    An experiment dealing with high-temperature superconducting devices and components in space is discussed. A variety of devices (primarily passive microwave and millimeter-wave components) has been procured and will be integrated with a cryogenic refrigerating and data acquisition system to form the space package, which will be launched in late 1992. This space experiment is expected to demonstrate that this technology is sufficiently robust to survive the space environment and that the technology has the potential to improve the operation of space systems significantly. The devices for the initial launch have been evaluated electrically, thermally, and mechanically, and will be integrated into the final space package early in 1991. The performance of the devices is summarized, and some potential applications of this technology in space systems are outlined.

  13. Dehydration transformation in Ca-montmorillonite

    Indian Academy of Sciences (India)

    P Bala; B K Samantaray; S K Srivastava

    2000-02-01

    The present work deals with the dehydration transformation of Ca-montmorillonite in the temperature range 30°–500°C. Thermal, infrared (IR), and X-ray diffraction (XRD) analyses were used to describe the thermal transformation. The microstructural and layer disorder parameters like crystallite size, r.m.s. strain ($\\langle e^2\\rangle^{1/2}$), variation of interlayer spacing (), and proportion of planes which were affected by the defect (), have all been calculated from the (001) basal reflection using the method of variance and Fourier line shape analysis. These investigations revealed that sample underwent transformation from hydrated phase to dehydrated phase at 200°C, and as a consequence, its basal spacing collapsed from 16.02 Å (30°C) to around 10 Å (200°C). This transformation occurred through a wide range of temperature, i.e. within the range 120°–200°C. The crystallite size was maximum at room temperature (30°C), however, the size decreased with increasing temperature in the hydrated phase, whereas the size increased with increasing temperature for the dehydrated phase. The , and $\\langle e^2\\rangle^{1/2}$ of the hydrated and the dehydrated phase increased and decreased, respectively with increase of heating temperature.

  14. Dehydration of the stratosphere

    Directory of Open Access Journals (Sweden)

    M. Schoeberl

    2011-03-01

    Full Text Available Domain filling, forward trajectory calculations are used to examine the global dehydration processes that control stratospheric water vapor. As with most Lagrangian models of this type, water vapor is instantaneously removed from the parcel to keep the relative humidity with respect to ice from exceeding saturation or a specified super-saturation value. We also test a simple parameterization of stratospheric convective moistening through ice lofting and the effect of gravity waves as a mechanism that can augment dehydration. Comparing diabatic and kinematic trajectories, we find, in agreement with previous authors, that the additional transport due to the vertical velocity "noise" in the kinematic calculation creates too dry a stratosphere and a too diffuse a water-vapor tape recorder signal compared observations. The diabatic simulations, on the other hand, produce stratospheric water vapor mixing ratios very close to that observed by Aura's Microwave Limb Sounder. Convective moistening, which will increases stratospheric HDO, also increases stratospheric water vapor while gravity waves do the opposite. We find that while the Tropical West Pacific is the dominant dehydration location, dehydration over Tropical South America is also important. Antarctica also makes a contribution to the overall stratospheric water vapor budget by releasing very dry air into the Southern Hemisphere stratosphere following the break up of the winter vortex.

  15. Microwave Assisted Hot Air Convective Dehydration of Fish Slice: Drying Characteristics, Energy Aspects and Colour Assessment

    Directory of Open Access Journals (Sweden)

    Mohd Rozainee Taib

    2011-01-01

    Full Text Available Dried fish is commonly produced by convective hot air drying. Microwave technology was presented in this paper to improve both process and product quality. Catfish (order Siluriformes slices were dehydrated in a microwave assisted hot air convective dehydration (MWHA system to investigate the effects of microwave power and hot air temperature on drying time, dehydration behaviour, energy consumption and colour of dried fish. Three different microwave power outputs namely medium (373 W, medium low (217 W and low (91 W combined with convective hot air temperature of 40°C, 70°C and 130°C accordingly were employed in the drying experiments. Results show that microwave accelerates drying time up to 120 folds faster compared to drying with hot air convective alone. It was also noted that increasing the hot air temperature was not as significant as increasing the microwave power in reducing the drying time. Experiments show that drying time was reduced about 75 % when an increase of microwave power from low (91 W to medium mode (373 W combining with convective hot air. However, drying with microwave alone required longer drying time. Energy consumption analysis shows that microwave assisted drying process requires less energy usage. Drying fish with microwave assisted hot air dehydration treatment make the colour brighter, shifting towards red and yellow.

  16. Dehydration-driven topotaxy in subduction zones

    Science.gov (United States)

    Padrón-Navarta, José Alberto; Tommasi, Andréa; Garrido, Carlos J.

    2014-05-01

    Mineral replacement reactions play a fundamental role in the chemistry and the strength of the lithosphere. When externally or internally derived fluids are present, interface-coupled dissolution-precipitation is the driving mechanism for such reactions [1]. One of the microstructural features of this process is a 3D arrangement of crystallographic axes across internal interfaces (topotaxy) between reactant and product phases. Dehydration reactions are a special case of mineral replacement reaction that generates a transient fluid-filled porosity. Among others, the dehydration serpentinite is of special relevance in subduction zones because of the amount of fluids involved (potentially up to 13 wt.%). Two topotatic relationships between olivine and antigorite (the serpentine mineral stable at high temperature and pressure) have been reported in partially hydrated mantle wedge xenoliths [2]. Therefore, if precursor antigorite serpentine has a strong crystallographic preferred orientation (CPO) its dehydration might result in prograde peridotite with a strong inherited CPO. However for predicting the importance of topotactic reactions for seismic anisotropy of subduction zones we also need to consider the crystallization orthopyroxene + chlorite in the prograde reaction and, more importantly, the fact that this dehydration reaction produces a transient porosity of ca. 20 % vol. that results in local fluctuations of strain during compaction and fluid migration. We address this issue by a microstructural comparison between the CPO developed in olivine, orthopyroxene and chlorite during high-pressure antigorite dehydration in piston cylinder experiments (at 750ºC and 20 kbar and 1000ºC and 30 kbar, 168 h) and that recorded in natural samples (Cerro del Almirez, Betic Cordillera, Spain). Experimentally developed CPOs are strong. Prograde minerals show a significant inheritance of the former antigorite foliation. Topotactic relations are dominated by (001)atg//(100)ol

  17. Hydrous mineral dehydration around heat-generating nuclear waste in bedded salt formations.

    Science.gov (United States)

    Jordan, Amy B; Boukhalfa, Hakim; Caporuscio, Florie A; Robinson, Bruce A; Stauffer, Philip H

    2015-06-02

    Heat-generating nuclear waste disposal in bedded salt during the first two years after waste emplacement is explored using numerical simulations tied to experiments of hydrous mineral dehydration. Heating impure salt samples to temperatures of 265 °C can release over 20% by mass of hydrous minerals as water. Three steps in a series of dehydration reactions are measured (65, 110, and 265 °C), and water loss associated with each step is averaged from experimental data into a water source model. Simulations using this dehydration model are used to predict temperature, moisture, and porosity after heating by 750-W waste canisters, assuming hydrous mineral mass fractions from 0 to 10%. The formation of a three-phase heat pipe (with counter-circulation of vapor and brine) occurs as water vapor is driven away from the heat source, condenses, and flows back toward the heat source, leading to changes in porosity, permeability, temperature, saturation, and thermal conductivity of the backfill salt surrounding the waste canisters. Heat pipe formation depends on temperature, moisture availability, and mobility. In certain cases, dehydration of hydrous minerals provides sufficient extra moisture to push the system into a sustained heat pipe, where simulations neglecting this process do not.

  18. Mild dehydration affects mood in healthy young women.

    Science.gov (United States)

    Armstrong, Lawrence E; Ganio, Matthew S; Casa, Douglas J; Lee, Elaine C; McDermott, Brendon P; Klau, Jennifer F; Jimenez, Liliana; Le Bellego, Laurent; Chevillotte, Emmanuel; Lieberman, Harris R

    2012-02-01

    Limited information is available regarding the effects of mild dehydration on cognitive function. Therefore, mild dehydration was produced by intermittent moderate exercise without hyperthermia and its effects on cognitive function of women were investigated. Twenty-five females (age 23.0 ± 0.6 y) participated in three 8-h, placebo-controlled experiments involving a different hydration state each day: exercise-induced dehydration with no diuretic (DN), exercise-induced dehydration plus diuretic (DD; furosemide, 40 mg), and euhydration (EU). Cognitive performance, mood, and symptoms of dehydration were assessed during each experiment, 3 times at rest and during each of 3 exercise sessions. The DN and DD trials in which a volunteer attained a ≥1% level of dehydration were pooled and compared to that volunteer's equivalent EU trials. Mean dehydration achieved during these DN and DD trials was -1.36 ± 0.16% of body mass. Significant adverse effects of dehydration were present at rest and during exercise for vigor-activity, fatigue-inertia, and total mood disturbance scores of the Profile of Mood States and for task difficulty, concentration, and headache as assessed by questionnaire. Most aspects of cognitive performance were not affected by dehydration. Serum osmolality, a marker of hydration, was greater in the mean of the dehydrated trials in which a ≥1% level of dehydration was achieved (P = 0.006) compared to EU. In conclusion, degraded mood, increased perception of task difficulty, lower concentration, and headache symptoms resulted from 1.36% dehydration in females. Increased emphasis on optimal hydration is warranted, especially during and after moderate exercise.

  19. Geothermal demonstration: Zunil food dehydration facility

    Energy Technology Data Exchange (ETDEWEB)

    Maldonado, O. (Consultecnia, Guatemala City (Guatemala)); Altseimer, J.; Thayer, G.R. (Los Alamos National Lab., NM (United States)); Cooper, L. (Energy Associates International, Albuquerque, NM (United States)); Caicedo, A. (Unidad de Desarrollo Geotermico, Guatemala City (Guatemala). Inst. Nacional de Electrificacion)

    1991-08-01

    A food dehydration facility was constructed near the town of Zunil, Guatemala, to demonstrate the use of geothermal energy for industrial applications. The facility, with some modifications to the design, was found to work quite satisfactorily. Tests using five different products were completed during the time geothermal energy was used in the plant. During the time the plant was not able to use geothermal energy, a temporary diesel-fueled boiler provided the energy to test dehydration on seven other crops available in this area. The system demonstrates that geothermal heat can be used successfully for dehydrating food products. Many other industrial applications of geothermal energy could be considered for Zunil since a considerable amount of moderate-temperature heat will become available when the planned geothermal electrical facility is constructed there. 6 refs., 15 figs., 7 tabs.

  20. Geothermal demonstration: Zunil food dehydration facility

    Energy Technology Data Exchange (ETDEWEB)

    Maldonado, O. (Consultecnia, Guatemala City (Guatemala)); Altseimer, J.; Thayer, G.R. (Los Alamos National Lab., NM (United States)); Cooper, L. (Energy Associates International, Albuquerque, NM (United States)); Caicedo, A. (Unidad de Desarrollo Geotermico, Guatemala City (Guatemala). Inst. Nacional de Electrificacion)

    1991-08-01

    A food dehydration facility was constructed near the town of Zunil, Guatemala, to demonstrate the use of geothermal energy for industrial applications. The facility, with some modifications to the design, was found to work quite satisfactorily. Tests using five different products were completed during the time geothermal energy was used in the plant. During the time the plant was not able to use geothermal energy, a temporary diesel-fueled boiler provided the energy to test dehydration on seven other crops available in this area. The system demonstrates that geothermal heat can be used successfully for dehydrating food products. Many other industrial applications of geothermal energy could be considered for Zunil since a considerable amount of moderate-temperature heat will become available when the planned geothermal electrical facility is constructed there. 6 refs., 15 figs., 7 tabs.

  1. Dehydration anorexia is attenuated in oxytocin-deficient mice.

    Science.gov (United States)

    Rinaman, Linda; Vollmer, Regis R; Karam, Joseph; Phillips, Donnesha; Li, Xia; Amico, Janet A

    2005-06-01

    Evidence in rats suggests that central oxytocin (OT) signaling pathways contribute to suppression of food intake during dehydration (i.e., dehydration anorexia). The present study examined water deprivation-induced dehydration anorexia in wild-type and OT -/- mice. Mice were deprived of food alone (fasted, euhydrated) or were deprived of both food and water (fasted, dehydrated) for 18 h overnight. Fasted wild-type mice consumed significantly less chow during a 60-min refeeding period when dehydrated compared with their intake when euhydrated. Conversely, fasting-induced food intake was slightly but not significantly suppressed by dehydration in OT -/- mice, evidence for attenuated dehydration anorexia. In a separate experiment, mice were deprived of water (but not food) overnight for 18 h; then they were anesthetized and perfused with fixative for immunocytochemical analysis of central Fos expression. Fos was elevated similarly in osmo- and volume-sensitive regions of the basal forebrain and hypothalamus in wild-type and OT -/- mice after water deprivation. OT-positive neurons expressed Fos in dehydrated wild-type mice, and vasopressin-positive neurons were activated to a similar extent in wild-type and OT -/- mice. Conversely, significantly fewer neurons within the hindbrain dorsal vagal complex were activated in OT -/- mice after water deprivation compared with activation in wild-type mice. These findings support the view that OT-containing projections from the hypothalamus to the hindbrain are necessary for the full expression of compensatory behavioral and physiological responses to dehydration.

  2. Experience of clinical characteristics and nursing of diarrhea and severe dehydration in children%腹泻合并重度脱水患儿的临床特点分析与护理体会

    Institute of Scientific and Technical Information of China (English)

    邓荣英

    2014-01-01

    目的:总结对小儿腹泻重度脱水诊治临床经验,探讨小儿腹泻重度脱水的临床诊治与护理方法。方法:回顾性总结90例小儿腹泻重度脱水患儿资料,对所有患儿进行加强心理护理,耐心细致的心理护理和正确、轻柔的操作护理。结果:90例患儿中,77例2d内明显好转,显效率为85%;86例患儿3d内明显好转,有效率96%。96%患儿经精心护理3d内腹泻症状显著改善,脱水现象及时缓解,精神状况好转,家长十分满意。结论:耐心细致的心理护理,正确、轻柔的操作护理措施和治疗后的生活护理对小儿腹泻重度脱水治疗具有重要的临床效果。%Objective: To summarize the clinical experience of diagnosis and treatment of infantile diarrhea in children with severe dehydration, to investigate the clinical diagnosis and treatment and nursing methods of children with diarrhea in children with severe dehydration. Methods: retrospective analysis of 90 cases of infantile diarrhea in children with severe dehydration, for all children to strengthen psychological nursing, psychological nursing and patient and correct, gentle operation nursing. Results:in 90 cases, 77 cases of 2D were improved, the effective rate was 85%; 86 cases of children with 3D were improved, the efficiency of 96%. 96% of children by careful nursing after 3D diarrhea symptoms improved, dehydration timely relief, mental state better, parents are very satisfied with the. Conclusion: nursing psychological nursing, correct operation, nursing measures and treatment of soft after the patient on infantile diarrhea in children with severe dehydration has important clinical effect.

  3. Progress report on the varying temperature experiment

    Energy Technology Data Exchange (ETDEWEB)

    Qualls, A.L.; Hurst, M.T.; Raby, D.G. [Oak Ridge National Lab., TN (United States)] [and others

    1997-08-01

    A capsule has been designed that permits four specimen sets to be irradiated in an RB* location in the High Flux Isotope reactor (HFIR) with distinct temperature histories. During the reporting period critical component prototyping was completed. The results have lead to some design and operational changes from that previously reported. The primary design changes are (1) compression seals in the specimen holes of the beryllium holders, and (2) oxide-dispersion strengthened aluminum alloy (DISPAL) specimen sleeves in all holders. Details of the capsule design are presented in the previous issue of this publication. Four, axially displaced temperature zones are independently controlled. Holder temperatures are monitored by thermocouples and controlled by a combination of adjustable temperature control gas mixtures and auxiliary heaters. The high temperature holders are located in the center of the experimental region, which is centered on the reactor mid-plane, and the low temperature holders are located at the ends of the experimental region.

  4. Effect of Dehydration Temperature on Essential Oil Content of Dried Matricaria chamomilla L.Nobile Flowers%不同干燥温度对西洋甘菊花及其精油的影响

    Institute of Scientific and Technical Information of China (English)

    雷伏贵; 周建金; 曹奕鸯; 胡启镔; 叶炜; 江金兰; 李永清

    2015-01-01

    Effect of dehydration temperature on the essential oil content of the dried Matricaria chamomilla L. Nobile flowers was studied.The chemical composition of the dried flowers was determined by means of steam distillation and GC-MS analysis.The experimental results indicated that the essential oil contents in the dried flowers dehydrated at various temperatures ranked as follows:0.134% at 60℃>0.117% at 55℃>0.115% at 50℃>0.102% at 25℃ (control)>0.099% at 45℃>0.097% at 40℃.The best fragrance retention was achieved by drying the flowers at 55℃ or 60℃ for 16 h.The best product appearance was resulted from dehydration at 45℃, 50℃ or 55℃.At 40℃,the dried flowers were least appealing.The compounds extracted included 8 alcohols,which contributed 45.97%-63.01% of the total essential oils,and were higher when the dehydration temperature of 25℃or 50℃ was applied.The 10 alkenes in the extract accounted for 17.46%-33.21% of the essential oils,and were higher in the flowers dried at 55℃ or 60℃.And,the essential oils consisted 16.12% -17.67% of chamazulene, and were higher in the flowers dried at 25℃ or 60℃.%采用水蒸气蒸馏法和气相色谱-质谱(GC-MS)联用技术研究不同干燥温度对西洋甘菊花、精油含有率及其成分的影响,结果表明:干燥温度对西洋甘菊干花精油含有率的影响排序为 A1(60℃,0.134%)>A2(55℃,0.117%)> A3(50℃,0.115%)> CK (25℃,0.102%)> A4(45℃,0.099%)> A5(40℃,0.097%);留香干燥以55~60℃为好,干燥时间以16 h 为宜;外观品相以45、50、55℃烘干品最好,60℃次之,40℃和阴干品最差;醇类物质8个,占总含量的45.97%~63.01%,以阴干品和50℃烘干品的含量较高;烯类物质10个,占总含量的17.46%~33.21%,以55℃和60℃烘干品的含量较高;母菊?占总含量的16.12%~17.67%,以阴干品和60℃烘干品的含量较高。

  5. Dehydration embrittlement of serpentine and its implications for earthquakes at depth

    Science.gov (United States)

    Jung, H.; Dobrzhinetskaya, L.; Green, H.

    2003-04-01

    Earthquakes at depths greater than ˜50 km cannot occur by unassisted brittle failure but could be triggered by embrittlement accompanying dehydration of hydrous minerals (e.g. Raleigh and Paterson, 1965). However, there is some question whether such embrittlement will occur if the ΔV of the dehydration reaction is negative, as occurs with increasing pressure for most low-pressure hydrous minerals. To test this hypothesis, we have chosen an extensively-serpentinized peridotite, in which the serpentine mineral present, antigorite, has a large stability field at elevated pressure and temperature. We conducted triaxial deformation experiments at constant strain rate using a Griggs-type apparatus at P = 1.0-3.4 GPa and T = 550-750 ^oC, and rapid-pumping experiments at comparable temperatures in a Walker-type multianvil apparatus, culminating at P = 6 GPa. Over this pressure range, the ΔV of reaction varies from highly positive to significantly negative. At the lowest temperatures, no reaction was observed. In deformation experiments at these conditions, faulting due to brittle failure was produced at low pressure but at high pressure deformation was ductile. At temperatures outside the stability field of antigorite, samples that were only pressurized and annealed did not show faulting. However, specimens subjected to a differential stress during dehydration displayed faults and localized zones of dehydration products consisting of very fine-grained new olivine or talc, +/- enstatite (grain size less than 200 nm). Deformed samples also showed Mode I cracks and fluid inclusions inside large crystals of relict olivine. Extensive fluid reactions were also observed along the grain boundaries between the relict olivine and antigorite. These observations indicate that antigorite dehydration under stress triggers faulting under conditions where the ΔV of reaction is negative as well as those where ΔV is positive. We do not yet know why this is so. We conclude that

  6. Onion dehydration: a review.

    Science.gov (United States)

    Mitra, Jayeeta; Shrivastava, S L; Rao, P S

    2012-06-01

    Onion (Allium cepa), a very commonly used vegetable, ranks third in the world production of major vegetables. Apart from imparting a delicious taste and flavour due to its pungency in many culinary preparations, it serves several medicinal purposes also. Processing and preservation of onion by suitable means is a major thrust area since a long time. The various kinds of treatments followed for dehydration of onion such as convective air drying, solar drying, fluidized bed drying, vacuum microwave drying, infrared drying and osmotic drying are reviewed here. These techniques are mainly used for preservation and value addition of onion. Several researchers have tried for decades to model the drying kinetics and quality parameters, which are also compiled here briefly.

  7. Natural gas dehydration by desiccant materials

    Directory of Open Access Journals (Sweden)

    Hassan A.A. Farag

    2011-12-01

    Increasing water vapor concentration in inlet feed gas leads to a marked decrease in dehydration efficiency. As expected, a higher inlet flow rate of natural gas decrease dehydration efficiency. Increasing feed pressure leads to higher dehydration efficiency.

  8. Downhole dehydration - status report and implementation study; Downhole Dehydration - Statusbericht und Umsetzungsstudie

    Energy Technology Data Exchange (ETDEWEB)

    Jacobs, D.; Schmidt, D. [BEB Erdgas und Erdoel GmbH, Hannover (Germany)

    1998-12-31

    Downhole dehydration, i.e. in-situ separation of water and oil, is an interesting new technology. The contribution describes the technology and the results of a field experiment. (orig.) [Deutsch] Die Tail-End Foerderphase in der deutschen Erdoelproduktion, welche durch hohe Wasserhebekosten gekennzeichnet ist, erfordert zur Aufrechterhaltung der Wirtschaftlichkeit neue Gedankenansaetze. Ein aus wirtschaftlicher und technischer Sicht reizvoller Optimierungsgedanke ist die untertaegige Wasser/Oel Separation, auch Downhole Dehydration genannt. Unter Downhole Dehydration (DHD) versteht man also die untertaegige (teilweise) Separation des Lagerstaettenwassers vom Nassoel, kurz nachdem das Gemisch untertaegig in das Bohrloch eingetreten ist. Dabei wird das abgetrennte Lagerstaettenwasser untertage in einen geeigneten Horizont unmittelbar wieder injiziert und das Oel (wie bei der konventionellen Foerderung) zutage gepumpt, mit dem Ziel der Nutzung der daraus resultierenden Kosten- und Investitionsersparnis. Ziel dieses Vortrages ist es, einen kurzen Einblick in die erstmalig in Europa angewandte Technik zu geben und von den Erfahrungen des praktizierten Feldversuches zu berichten. (orig.)

  9. Specimen loading list for the varying temperature experiment

    Energy Technology Data Exchange (ETDEWEB)

    Qualls, A.L.; Sitterson, R.G. [Oak Ridge National Lab., TN (United States)

    1998-09-01

    The varying temperature experiment HFIR-RB-13J has been assembled and inserted in the reactor. Approximately 5300 specimens were cleaned, inspected, matched, and loaded into four specimen holders. A listing of each specimen loaded into the steady temperature holder, its position in the capsule, and the identification of the corresponding specimen loaded into the varying temperature holder is presented in this report.

  10. Dehydration-induced drinking in humans

    Science.gov (United States)

    Greenleaf, J. E.

    1982-01-01

    The human tendency to experience a delay in rehydration (involuntary dehydration) after fluid loss is considered. The two primary factors contributing to involuntary dehydration are probably upright posture, and extracellular fluid and electrolyte loss by sweating from exercise and heat exposure. First, as the plasma sodium and osmotic concentrations remain virtually unchanged for supine to upright postural changes, the major stimuli for drinking appear to be associated with the hypovolemia and increase in the renin-angiotension system. Second, voluntary drinking during the heat experiments was 146% greater than in cool experiments; drinking increased by 109% with prior dehydration as opposed to normal hydration conditions; and drinking was increased by 41% after exercise as compared with the resting condition. Finally, it is concluded that the rate of sweating and the rate of voluntary fluid intake are highly correlated, and that the dispogenic factors of plasma volume, osmolality, and plasma renin activity are unrelated to sweat rate, but are likely to induce drinking in humans.

  11. Microglassification™: a Novel Technique for Protein Dehydration

    DEFF Research Database (Denmark)

    Aniket; Gaul, David; Rickard, Deborah

    2014-01-01

    he dehydration of biologics is commonly employed to achieve solid-dose formulation and enhanced stability during long-term preservation. We have developed a novel process, MicroglassificationTM, which can rapidly and controllably dehydrate protein solutions into solid amorphous microspheres at room...... temperature. Single bovine serum albumin (BSA) microdroplets were suspended in pentanol or decanol using a micropipette, and the dynamic changes in droplet dissolution were observed in real-time and correlated to protein's water of hydration, medium's water activity, and microsphere protein concentration....... MicroglassificationTM was also carried out at bulk scale, and changes in BSA secondary structure were analyzed by Fourier transform infrared spectroscopy and fluorescence spectroscopy; multimer formation was detected by native gel electrophoresis. BSA concentration in the microsphere increased with solvent exposure...

  12. Thermal Dehydration Kinetics of Gypsum and Borogypsum under Non-isothermal Conditions%在非等温条件下石膏和硼石膏的加热脱水动力学研究

    Institute of Scientific and Technical Information of China (English)

    ī.Y.Elbeyli; S.Piskin

    2004-01-01

    Thermal dehydration of gypsum and borogypsum was investigated under nonisothermal conditions in air by using simultaneous thermogravimetric-differential thermal analyzer. Nonisothermal experiments were carried out at various linear heating rates. Kinetics of dehydration in the temperature range of 373-503 K were evaluated from the DTA (differential thermal analysis)-TGA (thermogravimetric analysis) data by means of Coats-Redfern,Kissinger and Doyle Equations. Values of the activation energy and the pre-exponential factor of the dehydration were calculated. The results of thermal experiments and kinetic parameters indicated that borogypsum is similar to gypsum from dehydration mechanism point of view although it consists of boron and small amount of alkali metal oxides.

  13. An experimental study of dehydration melting of phengite-bearing eclogite at 1.5-3.0 GPa

    Institute of Scientific and Technical Information of China (English)

    LIU Qiang; JIN ZhenMin; ZHANG JunFeng

    2009-01-01

    Dehydration melting experiments were performed on ultrahigh-pressure eclogite from Bixiling in the Dabie orogen at 1.5-3.0 GPa and 800-950℃ using piston cylinder apparatus. The results show that (1)eclogite with ~5% phengite started to melt at T≤800-850℃ and P=1.5-2.0 GPa and produced about 3% granitic melt; (2) the products of dehydration melting of phengite-bearing eclogite vary with temperature and pressure. Fluid released from dehydration of phengite and zoisite leads to partial melting of eclogite and formation of plagioclase reaction rim around kyanite at pressures of 1.5-2.0 GPa and temperatures of 800-850℃; (3) phengite reacted with omphacite and quartz and produced oligoclase,kyanite and melt at elevated temperatures. Oligoclase is the primary reaction product produced by partial melting of phengite in the eclogite; and (4) the dehydration melting of phengite-bearing eclogite at pressures of 1.5-3.0 GPa and temperatures ≥900℃ results in formation of garnets with higher molar fraction of pyrope (37.67 wt.%-45.94 wt.%). Potassium feldspar and jadeite occur at P = 2.4-3.0GPa and T≥900℃, indicating higher pressure and fluid-absent conditions. Our results constrain the solidus for dehydration melting of phengite-bearing eclogite at pressures of 1.5-3.0 GPa. Combining experi- mental results with field observations of partial melting in natural eclogites, we concluded that phengite-bearing eclogites from the Dabie-Sulu orogen were able to partially molten at P= 1.5-2.0 GPa and T= 800-850℃ during exhumation. The ultrahigh-high pressure eclogites would have experienced partial melting in association with metamorphic phase transformation under different fluid conditions.

  14. Pulsed ultrasound assisted dehydration of waste oil.

    Science.gov (United States)

    Xie, Wei; Li, Rui; Lu, Xiaoping

    2015-09-01

    A method to aid the separation of the oil phase from waste oil emulsion of refineries had been developed by using a pulsed ultrasonic irradiation technology. Compared with conventional continuous ultrasonic irradiation, it is found that pulsed ultrasonic irradiation is much better to make water drop coalescence and hence dehydration of waste oil. The effects of ultrasonic irradiation parameters on waste oil dehydration are further discussed. The orthogonal experiment is also designed to investigate the degrees of influence of ultrasonic parameters and the optimal technological conditions. Under the optimal experimental conditions, the water content of waste oil is decreased from 65% to 8%, which thereby satisfies the requirements of refineries on the water content of waste oil after treatment (<10%). Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Thermal dehydration kinetics of phosphogypsum

    National Research Council Canada - National Science Library

    López, F. A; Tayibi, H; García-Díaz, I; Alguacil, F. J

    2015-01-01

    Phsophogypsum is a by-product from the processing phosphate rock. Before the use of it in cement industry such as setting regulator is necessary a study of dehydration reaction of phosphogypsum to avoid the false setting during the milling...

  16. GEANT4 simulation of water volume fraction measurement in dehydrated crude oil

    Institute of Scientific and Technical Information of China (English)

    JING Chunguo; XING Guangzhong; LIU Bin

    2007-01-01

    Online measurement of water volume fraction (WVF) in dehydrated crude oil is a difficult task due to very little water in dehydrated crude oil and high precision requirements. We presents a method to measure water volume fraction in dehydrated crude oil with γ-ray densitometry. The Monte Carlo computer simulation packet GEANT4 was used to analyze the WVF measuring sensitivity of the γ-ray densitometry at different γ-ray energies, and effects of temperature, pressure, salinity and oil components on WVF measurement. The results show that the γ-ray densitome-try has high sensitivity in γ-ray energy ranges of 16~25 keV, and it can distinguish WVF changes of 0.0005. The calculated WVF decreases about 0.0002 with 1 ℃ of temperature increase and they have approximately linear relation with temperature when water volume fraction remains the same. Effects of pressure, salinity and oil components on water volume fraction can be neglected. Experiments were done to analyze sensitivity of the γ-ray densitometry. The results, as compared with simulations, demonstrate that simulation method is reliable and it is feasible to gauge low water volume fraction using low energy γ-rays.

  17. Expression of genes involved in energy mobilization and osmoprotectant synthesis during thermal and dehydration stress in the Antarctic midge, Belgica antarctica.

    Science.gov (United States)

    Teets, Nicholas M; Kawarasaki, Yuta; Lee, Richard E; Denlinger, David L

    2013-02-01

    The Antarctic midge, Belgica antarctica, experiences sub-zero temperatures and desiccating conditions for much of the year, and in response to these environmental insults, larvae undergo rapid shifts in metabolism, mobilizing carbohydrate energy reserves to promote synthesis of low-molecular-mass osmoprotectants. In this study, we measured the expression of 11 metabolic genes in response to thermal and dehydration stress. During both heat and cold stress, we observed upregulation of phosphoenolpyruvate carboxykinase (pepck) and glycogen phosphorylase (gp) to support rapid glucose mobilization. In contrast, there was a general downregulation of pathways related to polyol, trehalose, and proline synthesis during both high- and low-temperature stress. Pepck was likewise upregulated in response to different types of dehydration stress; however, for many of the other genes, expression patterns depended on the nature of dehydration stress. Following fast dehydration, expression patterns were similar to those observed during thermal stress, i.e., upregulation of gp accompanied by downregulation of trehalose and proline synthetic genes. In contrast, gradual, prolonged dehydration (both at a constant temperature and in conjunction with chilling) promoted marked upregulation of genes responsible for trehalose and proline synthesis. On the whole, our data agree with known metabolic adaptations to stress in B. antarctica, although a few discrepancies between gene expression patterns and downstream metabolite contents point to fluxes that are not controlled at the level of transcription.

  18. Two-stage dehydration of sugars

    Science.gov (United States)

    Holladay, Johnathan E.; Hu, Jianli; Wang, Yong; Werpy, Todd A.

    2009-11-10

    The invention includes methods for producing dianhydrosugar alcohol by providing an acid catalyst within a reactor and passing a starting material through the reactor at a first temperature. At least a portion of the staring material is converted to a monoanhydrosugar isomer during the passing through the column. The monoanhydrosugar is subjected to a second temperature which is greater than the first to produce a dianhydrosugar. The invention includes a method of producing isosorbide. An initial feed stream containing sorbitol is fed into a continuous reactor containing an acid catalyst at a temperature of less than 120.degree. C. The residence time for the reactor is less than or equal to about 30 minutes. Sorbitol converted to 1,4-sorbitan in the continuous reactor is subsequently provided to a second reactor and is dehydrated at a temperature of at least 120.degree. C. to produce isosorbide.

  19. Natural gas dehydration by desiccant materials

    OpenAIRE

    Farag, Hassan A.A.; Mustafa Mohamed Ezzat; Hoda Amer; Adel William Nashed

    2011-01-01

    Water vapor in a natural gas stream can result in line plugging due to hydrate formation, reduction of line capacity due to collection of free water in the line, and increased risk of damage to the pipeline due to the corrosive effects of water. Therefore, water vapor must be removed from natural gas to prevent hydrate formation and corrosion from condensed water. Gas dehydration is the process of removing water vapor from a gas stream to lower the temperature at which water will condense ...

  20. Physiologic basis for understanding quantitative dehydration assessment.

    Science.gov (United States)

    Cheuvront, Samuel N; Kenefick, Robert W; Charkoudian, Nisha; Sawka, Michael N

    2013-03-01

    Dehydration (body water deficit) is a physiologic state that can have profound implications for human health and performance. Unfortunately, dehydration can be difficult to assess, and there is no single, universal gold standard for decision making. In this article, we review the physiologic basis for understanding quantitative dehydration assessment. We highlight how phenomenologic interpretations of dehydration depend critically on the type (dehydration compared with volume depletion) and magnitude (moderate compared with severe) of dehydration, which in turn influence the osmotic (plasma osmolality) and blood volume-dependent compensatory thresholds for antidiuretic and thirst responses. In particular, we review new findings regarding the biological variation in osmotic responses to dehydration and discuss how this variation can help provide a quantitative and clinically relevant link between the physiology and phenomenology of dehydration. Practical measures with empirical thresholds are provided as a starting point for improving the practice of dehydration assessment.

  1. Dehydration of chlorite explains anomalously high electrical conductivity in the mantle wedges.

    Science.gov (United States)

    Manthilake, Geeth; Bolfan-Casanova, Nathalie; Novella, Davide; Mookherjee, Mainak; Andrault, Denis

    2016-05-01

    Mantle wedge regions in subduction zone settings show anomalously high electrical conductivity (~1 S/m) that has often been attributed to the presence of aqueous fluids released by slab dehydration. Laboratory-based measurements of the electrical conductivity of hydrous phases and aqueous fluids are significantly lower and cannot readily explain the geophysically observed anomalously high electrical conductivity. The released aqueous fluid also rehydrates the mantle wedge and stabilizes a suite of hydrous phases, including serpentine and chlorite. In this present study, we have measured the electrical conductivity of a natural chlorite at pressures and temperatures relevant for the subduction zone setting. In our experiment, we observe two distinct conductivity enhancements when chlorite is heated to temperatures beyond its thermodynamic stability field. The initial increase in electrical conductivity to ~3 × 10(-3) S/m can be attributed to chlorite dehydration and the release of aqueous fluids. This is followed by a unique, subsequent enhancement of electrical conductivity of up to 7 × 10(-1) S/m. This is related to the growth of an interconnected network of a highly conductive and chemically impure magnetite mineral phase. Thus, the dehydration of chlorite and associated processes are likely to be crucial in explaining the anomalously high electrical conductivity observed in mantle wedges. Chlorite dehydration in the mantle wedge provides an additional source of aqueous fluid above the slab and could also be responsible for the fixed depth (120 ± 40 km) of melting at the top of the subducting slab beneath the subduction-related volcanic arc front.

  2. Dehydration: physiology, assessment, and performance effects.

    Science.gov (United States)

    Cheuvront, Samuel N; Kenefick, Robert W

    2014-01-01

    This article provides a comprehensive review of dehydration assessment and presents a unique evaluation of the dehydration and performance literature. The importance of osmolality and volume are emphasized when discussing the physiology, assessment, and performance effects of dehydration. The underappreciated physiologic distinction between a loss of hypo-osmotic body water (intracellular dehydration) and an iso-osmotic loss of body water (extracellular dehydration) is presented and argued as the single most essential aspect of dehydration assessment. The importance of diagnostic and biological variation analyses to dehydration assessment methods is reviewed and their use in gauging the true potential of any dehydration assessment method highlighted. The necessity for establishing proper baselines is discussed, as is the magnitude of dehydration required to elicit reliable and detectable osmotic or volume-mediated compensatory physiologic responses. The discussion of physiologic responses further helps inform and explain our analysis of the literature suggesting a ≥ 2% dehydration threshold for impaired endurance exercise performance mediated by volume loss. In contrast, no clear threshold or plausible mechanism(s) support the marginal, but potentially important, impairment in strength, and power observed with dehydration. Similarly, the potential for dehydration to impair cognition appears small and related primarily to distraction or discomfort. The impact of dehydration on any particular sport skill or task is therefore likely dependent upon the makeup of the task itself (e.g., endurance, strength, cognitive, and motor skill).

  3. Ion exchange and dehydration experimental studies of clinoptilolite: Implications to zeolite dating

    Energy Technology Data Exchange (ETDEWEB)

    WoldeGabriel, G.

    1995-02-01

    Variable effects were noted on the argon (Ar) and potassium (K) contents of clinoptilolite fractions used in ion-exchange and dehydration experiments. The K contents of clinoptilolite fractions were differently affected during cation exchange with Ca-, Cs-, K-, and Na-chloride solutions. Ar was generally less affected during these experiments, except for a Na-clinoptitolite fraction exchanged for five days. Loss of Ar during organic heavy-liquid treatment and cleaning using acetone and deionized water does occur, as indicated by comparing the amounts of radiogenic Ar of treated and untreated fractions. Moreover, a regular decrease in radiogenic Ar contents was noted in clinoptilolite fractions during dehydration experiments at different temperatures for 16 hours. Comparable losses do not occur from saturated samples that were heated in 100 C for more than five months. Water appears to play a vital role in stabilizing the clinoptilolite framework structure and in the retention of Ar. The radiogenic Ar depletion pattern noted in clinoptilolite fractions dehydrated in unsaturated environment at different temperatures is similar to variations in the amount of radiogenic Ar observed in clinoptilolite samples from the unsaturated zone of an altered tuff. These results can be used to evaluate the extent of zeolitic water (and hence Ar) retention in unsaturated geologic settings. The utility of alkali zeolites (e.g., phillipsite, clinoptilolite, and mordenite) from low-temperature, open-hydrologic alteration as potential dateable minerals was evaluated using the K/Ar method as part of the Yucca Mountain Site Characterization Project, which is evaluating Yucca Mountain, Nevada, as a potential high-level radioactive waste repository site.

  4. Low-temperature-induced expression of rice ureidoglycolate amidohydrolase is mediated by a C-repeat/dehydration-responsive element that specifically interacts with rice C-repeat-binding factor 3

    Directory of Open Access Journals (Sweden)

    Juan eLi

    2015-11-01

    Full Text Available Nitrogen recycling and redistribution are important for the environmental stress response of plants. In non nitrogen-fixing plants, ureide metabolism is crucial to nitrogen recycling from organic sources. Various studies have suggested that the rate-limiting components of ureide metabolism respond to environmental stresses. However, the underlying regulation mechanism is not well understood. In this report, rice ureidoglycolate amidohydrolase (OsUAH, which is a recently identified enzyme catalyzing the final step of ureide degradation, was identified as low-temperature- (LT but not abscisic acid- (ABA regulated. To elucidate the LT regulatory mechanism at the transcriptional level, we isolated and characterized the promoter region of OsUAH (POsUAH. Series deletions revealed that a minimal region between -522 and -420 relative to the transcriptional start site was sufficient for the cold induction of POsUAH. Detailed analyses of this 103-bp fragment indicated that a C-repeat/dehydration-responsive (CRT/DRE element localized at position -434 was essential for LT-responsive expression. A rice C-repeat-binding factors/DRE-binding proteins 1 (CBFs/DREB1s subfamily member, OsCBF3, was screened to specifically bind to the CRT/DRE element in the minimal region both in yeast one-hybrid assays and in in vitro gel-shift analysis. Moreover, the promoter could be exclusively trans-activated by the interaction between the CRT/DRE element and OsCBF3 in vivo. These findings may help to elucidate the regulation mechanism of stress-responsive ureide metabolism genes and provide an example of the member-specific manipulation of the CBF/DREB1 subfamily.

  5. Dehydration softening of serpentine and its roles in the intermediate-depth earthquakes

    Science.gov (United States)

    Shimizu, I.; Watanabe, Y.; Michibayashi, K.

    2010-12-01

    A popular hypothesis for the occurrence of double seismic zones in subducting slabs, located at the depth of about 50-200 km, is dehydration embrittlement of serpentinized mantle. Brittle failure of serpentinite has been attributed to excess pore fluid pressure caused by dehydration reaction (Raleigh and Paterson, 1965, JGR; Murrell and Ismail, 1976, Tectonophysics). However, in previous deformation experiments of serpentinites and other hydrous minerals using gas-medium apparatus, confining pressure was limited to 500 MPa, which corresponds to the depth of the middle crust (~15 km). It is questionable if the same mechanism could be effective in subducting slabs at higher pressures. We conducted constant strain-rate experiments of a serpentinite sample, which consists of almost pure antigorite, using solid-medium deformation apparatus. Cylindrical specimens of serpentinite with the diameter of 10 mm and the length of 15 mm were cut from the serpentinite sample and jacketed in Ag tubes. Deformation experiments were conducted at 500 oC and 700 oC under the confining pressure of 800 MPa. The temperature of the dehydration reaction is about 650 oC at this pressure. The strain rate ranges from 3.3x10-5 to 2x10-4 sec-1. At 500 oC, antigorite was very hard and not yielded even after differential stress exceeded 900 MPa. The samples deformed at 700 oC without pre-heating exhibited brittle failures and strain hardening. Dehydration reaction had not occurred in these samples. On the contrary, samples deformed at 700 oC after static heating exhibited steady creep behaviors. The yield strength of preheated samples were 200-280 MPa. The differential stress was slightly increased when the sample strain exceeds 5%. Velocity step tests indicated that the yield stress is insensitive to the strain rate. In the pre-heated samples, intergranular pores were developed. No cracks nor microfaults were observed after deformation experiments. The color of antigorite changed from dark green

  6. The BEAN experiment - An EISCAT study of ion temperature anisotropies

    Directory of Open Access Journals (Sweden)

    I. W. McCrea

    Full Text Available Results are presented from a novel EISCAT special programme, SP-UK-BEAN, intended for the direct measurement of the ion temperature anisotropy during ion frictional heating events in the high-latitude F-region. The experiment employs a geometry which provides three simultaneous estimates of the ion temperature in a single F-region observing volume at a range of aspect angles from 0° to 36°. In contrast to most previous EISCAT experiments to study ion temperature anisotropies, field-aligned observations are made using the Sodankylä radar, while the Kiruna radar measures at an aspect angle of the order of 30°. Anisotropic effects can thus be studied within a small common volume whose size and altitude range is limited by the radar beamwidth, rather than in volumes which overlap but cover different altitudes. The derivation of line-of-sight ion temperature is made more complex by the presence of an unknown percentage of atomic and molecular ions at the observing altitude and the possibility of non-Maxwellian distortion of the ion thermal velocity distribution. The first problem has been partly accounted for by insisting that a constant value of electron temperature be maintained. This enables an estimate of the ion composition to be made, and facilitates the derivation of more realistic line-of-sight ion temperatures and temperature anisotropies. The latter problem has been addressed by assuming that the thermal velocity distribution remains bi-Maxwellian. The limitations of these approaches are discussed. The ion temperature anisotropies and temperature partition coefficients during two ion heating events give values intermediate between those expected for atomic and for molecular species. This result is consistent with an analysis which indicates that significant proportions of molecular ions (up to 50% were present at the times of greatest heating.

  7. Uncertainty Quantification of Calculated Temperatures for the AGR-1 Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Binh T. Pham; Jeffrey J. Einerson; Grant L. Hawkes

    2012-04-01

    This report documents an effort to quantify the uncertainty of the calculated temperature data for the first Advanced Gas Reactor (AGR-1) fuel irradiation experiment conducted in the INL's Advanced Test Reactor (ATR) in support of the Next Generation Nuclear Plant (NGNP) R&D program. Recognizing uncertainties inherent in physics and thermal simulations of the AGR-1 test, the results of the numerical simulations can be used in combination with the statistical analysis methods to improve qualification of measured data. Additionally, the temperature simulation data for AGR tests can be used for validation of the fuel transport and fuel performance simulation models. The crucial roles of the calculated fuel temperatures in ensuring achievement of the AGR experimental program objectives require accurate determination of the model temperature uncertainties. The report is organized into three chapters. Chapter 1 introduces the AGR Fuel Development and Qualification program and provides overviews of AGR-1 measured data, AGR-1 test configuration and test procedure, and thermal simulation. Chapters 2 describes the uncertainty quantification procedure for temperature simulation data of the AGR-1 experiment, namely, (i) identify and quantify uncertainty sources; (ii) perform sensitivity analysis for several thermal test conditions; (iii) use uncertainty propagation to quantify overall response temperature uncertainty. A set of issues associated with modeling uncertainties resulting from the expert assessments are identified. This also includes the experimental design to estimate the main effects and interactions of the important thermal model parameters. Chapter 3 presents the overall uncertainty results for the six AGR-1 capsules. This includes uncertainties for the daily volume-average and peak fuel temperatures, daily average temperatures at TC locations, and time-average volume-average and time-average peak fuel temperatures.

  8. Uncertainty Quantification of Calculated Temperatures for the AGR-1 Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Binh T. Pham; Jeffrey J. Einerson; Grant L. Hawkes

    2013-03-01

    This report documents an effort to quantify the uncertainty of the calculated temperature data for the first Advanced Gas Reactor (AGR-1) fuel irradiation experiment conducted in the INL’s Advanced Test Reactor (ATR) in support of the Next Generation Nuclear Plant (NGNP) R&D program. Recognizing uncertainties inherent in physics and thermal simulations of the AGR-1 test, the results of the numerical simulations can be used in combination with the statistical analysis methods to improve qualification of measured data. Additionally, the temperature simulation data for AGR tests can be used for validation of the fuel transport and fuel performance simulation models. The crucial roles of the calculated fuel temperatures in ensuring achievement of the AGR experimental program objectives require accurate determination of the model temperature uncertainties. The report is organized into three chapters. Chapter 1 introduces the AGR Fuel Development and Qualification program and provides overviews of AGR-1 measured data, AGR-1 test configuration and test procedure, and thermal simulation. Chapters 2 describes the uncertainty quantification procedure for temperature simulation data of the AGR-1 experiment, namely, (i) identify and quantify uncertainty sources; (ii) perform sensitivity analysis for several thermal test conditions; (iii) use uncertainty propagation to quantify overall response temperature uncertainty. A set of issues associated with modeling uncertainties resulting from the expert assessments are identified. This also includes the experimental design to estimate the main effects and interactions of the important thermal model parameters. Chapter 3 presents the overall uncertainty results for the six AGR-1 capsules. This includes uncertainties for the daily volume-average and peak fuel temperatures, daily average temperatures at TC locations, and time-average volume-average and time-average peak fuel temperatures.

  9. Experiments on Quantum Hall Topological Phases in Ultra Low Temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Du, Rui-Rui [Rice Univ., Houston, TX (United States). Dept. of Physics and Astronomy

    2015-02-14

    This project is to cool electrons in semiconductors to extremely low temperatures and to study new states of matter formed by low-dimensional electrons (or holes). At such low temperatures (and with an intense magnetic field), electronic behavior differs completely from ordinary ones observed at room temperatures or regular low temperature. Studies of electrons at such low temperatures would open the door for fundamental discoveries in condensed matter physics. Present studies have been focus on topological phases in the fractional quantum Hall effect in GaAs/AlGaAs semiconductor heterostructures, and the newly discovered (by this group) quantum spin Hall effect in InAs/GaSb materials. This project consists of the following components: 1) Development of efficient sample cooling techniques and electron thermometry: Our goal is to reach 1 mK electron temperature and reasonable determination of electron temperature; 2) Experiments at ultra-low temperatures: Our goal is to understand the energy scale of competing quantum phases, by measuring the temperature-dependence of transport features. Focus will be placed on such issues as the energy gap of the 5/2 state, and those of 12/5 (and possible 13/5); resistive signature of instability near 1/2 at ultra-low temperatures; 3) Measurement of the 5/2 gaps in the limit of small or large Zeeman energies: Our goal is to gain physics insight of 5/2 state at limiting experimental parameters, especially those properties concerning the spin polarization; 4) Experiments on tuning the electron-electron interaction in a screened quantum Hall system: Our goal is to gain understanding of the formation of paired fractional quantum Hall state as the interaction pseudo-potential is being modified by a nearby screening electron layer; 5) Experiments on the quantized helical edge states under a strong magnetic field and ultralow temperatures: our goal is to investigate both the bulk and edge states in a quantum spin Hall insulator under time

  10. Characterization and Neutron Shielding Behavior of Dehydrated Magnesium Borate Minerals Synthesized via Solid-State Method

    Directory of Open Access Journals (Sweden)

    Azmi Seyhun Kipcak

    2013-01-01

    Full Text Available Magnesium borates are one of the major groups of boron minerals that have good neutron shielding performance. In this study, dehydrated magnesium borates were synthesized by solid-state method using magnesium oxide (MgO and boron oxide (B2O3, in order to test their ability of neutron shielding. After synthesizing the dehydrated magnesium borates, characterizations were done by X-ray Diffraction (XRD, fourier transform infrared (FT-IR, Raman spectroscopy, and scanning electron microscopy (SEM. Also boron oxide (B2O3 contents and reaction yields (% were calculated. XRD results showed that seven different types of dehydrated magnesium borates were synthesized. 1000°C reaction temperature, 240 minutes of reaction time, and 3 : 2, 1 : 1 mole ratios of products were selected and tested for neutron transmission. Also reaction yields were calculated between 84 and 88% for the 3 : 2 mole ratio products. The neutron transmission experiments revealed that the 3 : 2 mole ratio of MgO to B2O3 neutron transmission results (0.618–0.655 was better than the ratio of 1 : 1 (0.772–0.843.

  11. NONCHEMICAL DEHYDRATION OF FIXED TISSUE COMBINING MICROWAVES AND VACUUM

    NARCIS (Netherlands)

    KOK, LP; BOON, ME

    A novel histoprocessing method for paraffin and plastic sections is presented in which dehydration of fixed tissue blocks is achieved within 5 minutes by microwaving under vacuum. Exploiting the decrease in boiling temperature under vacuum, we succeed in evaporating liquid molecules in the tissues

  12. Dehydration softening of serpentine as a trigger of intermediate-depth earthquakes

    Science.gov (United States)

    Shimizu, I.; Watanabe, Y.; Michibayashi, K.; Uehara, S.; Takahashi, M.; Katsuta, N.

    2011-12-01

    A popular hypothesis for the occurrence of double seismic zones in subducting slabs is dehydration embrittlement of serpentinized mantle. Deformation experiments of serpentinites using gas-medium apparatus demonstrated the role of pore pressure in the ductile-to-brittle transition at the dehydration temperature (e.g., Raleigh and Paterson, 1965, JGR). However, it is questionable if the same mechanism could be effective in subducting slabs at the depth. Deformation experiments of serpentinites have been also conducted at higher pressure using multi-anvil and Griggs-type apparatus but little is known about the effects of dehydration reaction on the mechanical behavior of serpentinite. We conducted deformation experiments of antigorite-serpentinite (Oeyama ultramafic body, Japan). Cylindrical samples of serpentinite with the diameter of 10 mm and the length of 15 mm were jacketed in Ag tubes and disks. "Slow" and "fast" experiments were conducted at strain rates of 3.3x10-5 sec -1 and 2x10-4 sec-1, respectively. Axial compression tests were conducted at 800 MPa confining pressure using a solid-medium deformation apparatus. The dehydration temperature is about 650 oC at this pressure. Antigorite was hard at 500oC and not yielded up to 900 MPa differential stress. The experimental run at 700oC without pre-heating is characterized by strain hardening. The sample was deformed by foliation-parallel slip, kinking, and micro-faulting of antigorite. On the contrary, samples deformed at 700oC after static heating showed drastic weakening and steady creep behaviors. A velocity step test indicated that the flow stress is insensitive to the strain rate. The deformed samples contain forsterite and enstatite in the antigorite matrix. Antigorite changed in color from dark green to pink, possibly due to highly oxidized atmosphere resulting from free water release. Intergranular pores were well developed. No microcracks or microfaults were observed. No evidence for intracrystalline

  13. Hot air convective dehydration characteristics of Daucus carota var. Nantes

    Directory of Open Access Journals (Sweden)

    Raees-ul Haq

    2015-12-01

    Full Text Available The present work focuses on experimental and theoretical study of air dehydration kinetics of Daucus carota var. Nantes in laboratory scale drying chamber. Steam blanching as a pretreatment was applied prior to dehydration of shreds and the results indicated a gradual decrease in drying time from 2.9 to 5.5% in temperature range of 50–70°C, for steam blanched samples in comparison to untreated carrots. Four different mathematical drying models (Newton, Page, Modified Page and Henderson and Pabis were evaluated for goodness of fit by comparing their respective R2, χ2, and RMSE parameters. Comparison of the statistical parameters led to conclusion that Page model showed a better quality of fit and presents dehydration characteristics in better way to obtain drying curves than any other model.

  14. Hypernatremic Dehydration in Breastfed Infants

    Directory of Open Access Journals (Sweden)

    Hacer Ergin

    2013-08-01

    Full Text Available Introduction: Since it can cause life-threatening complications in newborns, diagnosis and treatment of hypernatremic dehydration associated with inadequate breastfeeding is important.Materials and Methods: Records of exclusively-breastfed newborns (37-42 weeks with hypernatremic dehydration (serum Na ≥150mEq/L admitted between 2006 and 2012 were reviewed retrospectively.Results: The mean gestational age, birth weight, weight loss, maternal age, and age at diagnosis of 26 newborns with hypernatremic dehydration were 38.8±1.1 weeks, 3292±458 gr, 13.5±5.5%, 27.6±4.9 years, and 3.9±3.5 days, respectively. The percentages of female patients, caesarean delivery, and primipar mothers were 57.6%, 61.6%, and 57.6% respectively. Admission complaints were fever (30.7%, poor feeding and jaundice (26.9%, restlessness and hypoactivity (7.6%. Hypernatremic dehydration frequency within first five days, in summer season, during hospitalization were 84.6%, 73%, and 42.3%, respectively. The mean serum BUN, creatinine, Na levels were found 45.6±64.1 mg/dl, 1.5±2.3mg/dl, and 157±11.9 mEq/L, respectively. Of 26 mothers, 57.6% had received breastfeeding education and 84% had inadequate fluid intake. Among four patients with seizures, three had prerenal failure, one had renal failure requiring dialysis, and brain edema developed in one. Serum Na levels were higher in infants who were baby of primipar mother (p=0.002, born in another hospital (p=0.012, from young mothers (p=0.035, from mothers with no breastfeeding education (p=0.007, and with delayed hospital admission (p<0.01. Serum Na concentrations ≥160mEq/L were associated with complications (p<0.01. Serum Na levels were negatively correlated with maternal age (p=0.035 and positively correlated with (p=0.016 weight loss.Conclusions: Hypernatremic dehydration can be prevented in newborns by close monitoring of weight loss and by teaching successful breastfeeding techniques and signs of dehydration to

  15. Dehydration project report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-08-31

    Catalytic Industrial Group became interested in the ability to use its catalytic infrared technology for the removal of moisture in substances after having had very positive experience in removing moisture from water-based coatings which are becoming increasingly popular as industry strives to comply with clean air mandates. The first attempts were crude but showed that the moisture could be removed, and intriguing enough that they started to think about a conveying-based system that would remove moisture from products. The initial tests were designed around sawdust. The authors felt that the market in particleboard and in the MDF board by itself justified the research into this concept. The Kansas Department of Health and Environment has been kept apprised of the on-going development of the infrared drying system by Catalytic Industrial Group. There were some early delays in the delivery of equipment needed to build the prototype machine. The design changes identified during the experimental phase of the development of the infrared dryer have been resolved and a process-testing device has been developed. This technical report outlines the progress made to date.

  16. Studying of Lactulose Hygroscopicity and Microstructure after Spray Dehydration

    Directory of Open Access Journals (Sweden)

    Andrei Lisitsyn

    2016-05-01

    Full Text Available Investigations in the present work were directed towards the study of the dehydration temperature influence on the mass fraction of moisture in lactulose. The moisture mass fraction index is the most important to estimate the quality of primary, semi-finished and finished products. Resulting from this, investigations have been directed onto the study of the dehydration temperature influence on the mass fraction of moisture in the solution. A technology of getting dry lactulose by way of spray dehydration has been developed. It has been proved that while the temperature of dehydrating a lactulose solution with the mass fraction of 50% rises, the moisture content in the product decreases. The lactulose powder quality was estimated by such factors as mass fraction of moisture, particle size, solubility index and hydroscopicity, as these factors produce the most influence upon consumer properties of the products. The data received show growth of the lactulose solubility index with the particle size increase. This is evidently connected with the fact that a big size of the particles makes interaction between molecules of water and lactulose more difficult as well as forming donor and acceptor (hydrogen bonds, and consequently the solution process.

  17. Alcohol dehydration: Mechanism of ether formation using an alumina catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Shi, B.; Davis, B.H. [Univ. of Kentucky, Lexington, KY (United States)

    1995-12-01

    Ether formation during the dehydration of secondary alcohols, namely, 2-butanol, 3-pentanol, and 1-cyclopentylethanol, was investigated. Using the proper reaction conditions, the yield of di-2-butyl ether during the dehydration of 2-butanol on alumina can be as high as 40%. That ether is formed by adding an alcohol to the alkene is ruled out by the results from deuterium tracer studies. Results from experiments using S(+)- 2-butanol suggest that the formation of di-2-butyl ether occurs by a S{sub N}2-type mechanism. 33 refs., 5 figs., 3 tabs.

  18. Presence and significance of Bacillus cereus in dehydrated potato products.

    Science.gov (United States)

    King, Nicola J; Whyte, Rosemary; Hudson, J Andrew

    2007-02-01

    Dehydrated potato contains Bacillus cereus at a prevalences of 10 to 40% and at numbers usually less than 10(3) CFU g(-1). B. cereus in dehydrated potato is likely to be present as spores that are able to survive drying of the raw vegetable and may represent a significant inoculum in the reconstituted (rehydrated) product where conditions favor germination of, and outgrowth from, spores. Holding rehydrated mashed potato alone, or as part of another product (e.g., potato-topped pie), at temperatures above 10 degrees C and below 60 degrees C may allow growth of vegetative B. cereus. Levels exceeding 10(4) CFU g(-1) are considered hazardous to human health and may be reached within a few hours if stored inappropriately between these temperatures. Foods incorporating mashed potato prepared from dehydrated potato flakes have been implicated in B. cereus foodborne illness. This review is a summary of the information available concerning the prevalence and numbers of B. cereus in dehydrated potato flakes and the rate at which growth might occur in the rehydrated product.

  19. Effect of simultaneous infrared dry-blanching and dehydration on quality characteristics of carrot slices

    Science.gov (United States)

    This study investigated the effects of various processing parameters on carrot slices exposed to infrared (IR) radiation heating for achieving simultaneous infrared dry-blanching and dehydration (SIRDBD). The investigated parameters were product surface temperature, slice thickness and processing ti...

  20. Diamond detectors for high-temperature transactinide chemistry experiments

    Science.gov (United States)

    Steinegger, Patrick; Dressler, Rugard; Eichler, Robert; Piguet, Dave; Streuli, Silvan; Türler, Andreas

    2017-04-01

    Here, we present the fabrication details and functional tests of diamond-based α-spectroscopic sensors, dedicated for high-temperature experiments, targeting the chemistry of transactinide elements. Direct heating studies with this sensor material, revealed a current upper temperature threshold for a safe α-spectroscopic operation of Tdet = 453 K . Up to this temperature, the diamond sensor could be operated in a stable manner over long time periods of the order of days. A satisfying resolution of ≈ 50 keVFWHM was maintained throughout all conducted measurements. However, exceeding the mentioned temperature limit led to a pronounced spectroscopic degradation in the range of 453 - 473 K , thereby preventing any further α-spectroscopic application. These findings are in full agreement with available literature data. The presented detector development generally enables the chemical investigation of more short-lived and less volatile transactinide elements and their compounds, yet unreachable with the currently employed silicon-based solid state sensors. In a second part, the design, construction, and α-spectroscopic performance of a 4-segmented diamond detector, dedicated and used for transactinide element research, is given as an application example.

  1. Methods to increase the rate of mass transfer during osmotic dehydration of foods

    Directory of Open Access Journals (Sweden)

    Anna Chwastek

    2014-12-01

    Full Text Available Traditional methods of food preservation such as freezing, freeze drying (lyophilization, vacuum drying, convection drying are often supplemented by new technologies that enable obtaining of high quality products. Osmotic dehydration is more and more often used during processing of fruits and vegetables. This method allows maintaining good organoleptic and functional properties in the finished product. Obtaining the desired degree of dehydration or saturation of the material with an osmoactive substance often requires  elongation of time or use of high temperatures. In recent years much attention was devoted to techniques aimed at increasing the mass transfer between the dehydrated material and the hypertonic solution. The work reviews the literature focused on methods of streamlining the process of osmotic dehydration which include the use of: ultrasound, high hydrostatic pressure, vacuum osmotic dehydration and pulsed electric field.

  2. Cost- and energy-efficient dehydration of unconventional oil using disc-stack centrifuges

    Energy Technology Data Exchange (ETDEWEB)

    Agrell, J. [Alfa Laval Tumba AB, Stockholm (Sweden)

    2008-07-01

    Centrifuge dehydration methods for heavy oils were discussed. The high viscosity of heavy oils can mean that emulsions are often stabilized by surface-active compounds that occur naturally in the oil during dehydration processes. Disc-stack centrifuges are used to dehydrate crude oils without the excessive need for chemical treatments and wash water. The lower separation temperatures mean that dehydration can be accomplished with reduced energy inputs and lower carbon dioxide (CO{sub 2}) emissions. The main challenges to efficient crude oil dehydration were identified as the small density difference between oil and water; high oil viscosity; higher solids content; and the tight emulsions formed through oil processing. It was concluded that separation at higher viscosities leads to reduced heating requirements and increased energy savings. Continuous solids discharge make it possible for large amounts of solids to be processed. 3 refs.

  3. A DFT-based comparative equilibrium study of thermal dehydration and hydrolysis of CaCl₂ hydrates and MgCl₂ hydrates for seasonal heat storage.

    Science.gov (United States)

    Pathak, Amar Deep; Nedea, Silvia; Zondag, Herbert; Rindt, Camilo; Smeulders, David

    2016-04-21

    Salt hydrates store solar energy in chemical form via a reversible dehydration-hydration reaction. However, as a side reaction to dehydration, hydrolysis (HCl formation) may occur in chloride based salt hydrates (specially in MgCl2 hydrates), affecting the durability of the storage system. The mixture of CaCl2 and MgCl2 hydrates has been shown experimentally to have exceptional cycle stability and improved kinetics. However, the optimal operating conditions for the mixture are unknown. To understand the appropriate balance between dehydration and hydrolysis kinetics in the mixtures, it is essential to gain in-depth insight into the mixture components. We present a GGA-DFT level study to investigate the various gaseous structures of CaCl2 hydrates and to understand the relative stability of their conformers. The hydration strength and relative stability of conformers are dominated by electrostatic interactions. A wide network of intramolecular homonuclear and heteronuclear hydrogen bonds is observed in CaCl2 hydrates. Equilibrium product concentrations are obtained during dehydration and hydrolysis reactions under various temperature and pressure conditions. The trend of the dehydration curve with temperature in CaCl2 hydrates is similar to the experiments. Comparing these results to those of MgCl2 hydrates, we find that CaCl2 hydrates are more resistant towards hydrolysis in the temperature range of 273-800 K. Specifically, the present study reveals that the onset temperatures of HCl formation, a crucial design parameter for MgCl2 hydrates, are lower than for CaCl2 hydrates except for the mono-hydrate.

  4. Mathematical modeling of dehydration of 'Fuji' and 'Gala' apples slices using infrared

    Directory of Open Access Journals (Sweden)

    Emílio de Souza Santos

    2011-09-01

    Full Text Available The objective of this work was to determine and model the infrared dehydration curves of apple slices - Fuji and Gala varieties. The slices were dehydrated until constant mass, in a prototype dryer with infrared heating source. The applied temperatures ranged from 50 to 100 °C. Due to the physical characteristics of the product, the dehydration curve was divided in two periods, constant and falling, separated by the critical moisture content. A linear model was used to describe the constant dehydration period. Empirical models traditionally used to model the drying behavior of agricultural products were fitted to the experimental data of the falling dehydration period. Critical moisture contents of 2.811 and 3.103 kgw kgs-1 were observed for the Fuji and Gala varieties, respectively. Based on the results, it was concluded that the constant dehydration rates presented a direct relationship with the temperature; thus, it was possible to fit a model that describes the moisture content variation in function of time and temperature. Among the tested models, which describe the falling dehydration period, the model proposed by Midilli presented the best fit for all studied conditions.

  5. Temperature calibration of the E and B experiment

    CERN Document Server

    Aubin, Francois; Ade, Peter; Araujo, Derek; Baccigalupi, Carlo; Bao, Chaoyun; Borrill, Julian; Chapman, Daniel; Didier, Joy; Dobbs, Matt; Feeney, Stephen; Geach, Christopher; Hanany, Shaul; Helson, Kyle; Hillbrand, Seth; Hilton, Gene; Hubmayr, Johannes; Jaffe, Andrew; Johnson, Bradley; Jones, Terry; Kisner, Theodore; Klein, Jeff; Korotkov, Andrei; Lee, Adrian; Levinson, Lorne; Limon, Michele; Macdermid, Kevin; Marchenko, Valerie; Miller, Amber D; Milligan, Michael; Pascale, Enzo; Puglisi, Giuseppe; Raach, Kate; Reichborn-Kjennerud, Britt; Reintsema, Carl; Sagiv, Ilan; Smecher, Graeme; Stompor, Radek; Tristram, Matthieu; Tucker, Gregory S; Westbrook, Ben; Young, Karl; Zilic, Kyle

    2016-01-01

    The E and B Experiment (EBEX) is a balloon-borne polarimeter designed to measure the polarization of the cosmic microwave background radiation and to characterize the polarization of galactic dust. EBEX was launched December 29, 2012 and circumnavigated Antarctica observing $\\sim$6,000 square degrees of sky during 11 days at three frequency bands centered around 150, 250 and 410 GHz. EBEX was the first experiment to operate a kilo-pixel array of transition-edge sensor bolometers and a continuously rotating achromatic half-wave plate aboard a balloon platform. It also pioneered the use of detector readout based on digital frequency domain multiplexing. We describe the temperature calibration of the experiment. The gain response of the experiment is calibrated using a two-step iterative process. We use signals measured on passes across the Galactic plane to convert from readout-system counts to power. The effective smoothing scale of the EBEX optics and the star camera-to-detector offset angles are determined t...

  6. The THS experiment: probing Titan's atmospheric chemistry at low temperature

    Science.gov (United States)

    Sciamma-O'Brien, Ella; Upton, Kathleen; Beauchamp, Jack L; Salama, Farid

    2014-06-01

    In Titan’s atmosphere, a complex chemistry between N2 and CH4 occurs at temperatures lower than 200K and leads to the production of heavy molecules and subsequently solid aerosols that form the haze surrounding Titan. The Titan Haze Simulation (THS) experiment has been developed at the NASA Ames COSmIC facility to study Titan’s atmospheric chemistry at low temperature in order to help interpret Cassini’s observational data. In the THS, the chemistry is simulated by plasma in the stream of a supersonic expansion. With this unique design, the gas is jet-cooled to Titan-like temperature 150K) before inducing the chemistry by plasma, and remains at low temperature in the plasma discharge 200K). Different N2-CH4-based gas mixtures can be injected in the plasma, with or without the addition of heavier precursors present as trace elements on Titan. Both the gas phase and solid phase products resulting from the plasma-induced chemistry can be monitored and analyzed using a combination of complementary in situ and ex situ diagnostics.Here we present the complementary results of two studies of the gas and solid phase. A Mass spectrometry analysis of the gas phase has demonstrated that the THS experiment is a unique tool to probe the first and intermediate steps as well as specific chemical pathways of Titan’s atmospheric chemistry at Titan-like temperature. The more complex chemistry, observed in the gas phase when adding trace elements to the initial N2-CH4 mixture, has also been confirmed by an extensive study of the solid phase products: Scanning Electron Microscopy images have shown that aggregates produced in N2-CH4-C2H2-C6H6 mixtures (up to 5 μm in diameter) are much larger than those produced in N2-CH4 mixtures (0.1-0.5 μm), and Nuclear Magnetic Resonance results support a growth evolution of the chemistry when adding acetylene to the N2-CH4 mixture, resulting in the production of more complex hydrogen bonds than with a simple N2-CH4 mixture

  7. Persistence of Salmonella enterica during dehydration and subsequent cold storage.

    Science.gov (United States)

    Gruzdev, Nadia; Pinto, Riky; Sela Saldinger, Shlomo

    2012-12-01

    Despite the fact that Salmonella enterica serotype Typhimurium SL 1344 has served as a model pathogen in many studies, information regarding its desiccation response is still scarce. In this study, we investigated environmental conditions that affect Salmonella survival following dehydration and subsequent cold storage, using a 96-well polystyrene plate model. The SL 1344 strain exhibited high survival compared with other Typhimurium isolates and S. enterica serotypes. Further characterization of desiccation tolerance in this strain revealed that temperature, stationary-phase of growth, solid medium, and the presence of increasing NaCl concentrations (0.5-5.0%) in the growth medium enhanced desiccation tolerance. Dehydration at basic pHs (8-10), or in trehalose, sucrose, but not in glycine-betaine, improved bacterial persistence. Dehydrated Salmonella survived over 100 weeks at 4 °C with a ∼5-log reduction in numbers. However, viability staining revealed only a ∼50% reduction in viable cells, suggesting bacterial transition into a viable-but-not-cultivable state (VBNC). Addition of chloramphenicol reduced bacterial survival implying that adaptation to desiccation stress requires de-novo protein synthesis. Consistent with this finding, shortening the dehydration time resulted in lower survival. This study emphasizes the impact of environmental conditions on the fate of dried Salmonella in the food chain and highlights the potential transition of the pathogen to the VBNC state. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. Insights on TTL Dehydration Mechanisms from Microphysical Modelling of Aircraft Observations

    Science.gov (United States)

    Ueyama, R.; Pfister, L.; Jensen, E.

    2014-01-01

    The Tropical Tropopause Layer (TTL), a transition layer between the upper troposphere and lower stratosphere in the tropics, serves as the entryway of various trace gases into the stratosphere. Of particular interest is the transport of water vapor through the TTL, as WV is an important greenhouse gas and also plays a significant role in stratospheric chemistry by affecting polar stratospheric cloud formation and the ozone budget. While the dominant control of stratospheric water vapor by tropical cold point temperatures via the "freeze-drying" process is generally well understood, the details of the TTL dehydration mechanisms, including the relative roles of deep convection, atmospheric waves and cloud microphysical processes, remain an active area of research. The dynamical and microphysical processes that influence TTL water vapor concentrations are investigated in simulations of cloud formation and dehydration along air parcel trajectories. We first confirm the validity of our Lagrangian models in a case study involving measurements from the Airborne Tropical TRopopause EXperiment (ATTREX) flights over the central and eastern tropical Pacific in Oct-Nov 2011 and Jan-Feb 2013. ERA-Interim winds and seasonal mean heating rates from Yang et al. (2010) are used to advance parcels back in time from the flight tracks, and time-varying vertical profiles of water vapor along the diabatic trajectories are calculated in a one-dimensional cloud model as in Jensen and Pfister (2004) but with more reliable temperature field, wave and convection schemes. The simulated water vapor profiles demonstrate a significant improvement over estimates based on the Lagrangian Dry Point, agreeing well with aircraft observations when the effects of cloud microphysics, subgrid-scale gravity waves and convection are included. Following this approach, we examine the dynamical and microphysical control of TTL water vapor in the 30ºS-30ºN latitudinal belt and elucidate the dominant processes

  9. Subsurface monitoring of reservoir pressure, temperature, relative humidity, and water content at the CAES Field Experiment, Pittsfield, Illinois: system design

    Energy Technology Data Exchange (ETDEWEB)

    Hostetler, D.D.; Childs, S.W.; Phillips, S.J.

    1983-03-01

    This subsurface-instrumentation design has been developed for the first Compressed Air Energy Storage (CAES) field experiment to be performed in porous media. Energy storage will be accomplished by alternating the injection and withdrawal of compressed air in a confined sandstone aquifer near Pittsfield, Illinois. The overall experiment objective is to characterize the reservoir's geochemical and thermohydraulic response to imposed CAES conditions. Specific experiment objectives require monitoring: air-bubble development; thermal development; cyclic pressure response; reservoir dehydration; and water coning. Supporting these objectives, four parameters will be continuously monitored at depth in the reservoir. They are: temperature; pressure; pore-air relative humidity; and pore-water content. Reservoir temperatures and pressures will range to maximum values approaching 200/sup 0/C and 300 psi, respectively. Both pore-air relative humidity and pore-water content will range from approx. 0 to 100%. This report discusses: instrumentation design; sensor and sensor system calibration; field installation and testing; and instrument-system operation. No comprehensive off-the-shelf instrument package exists to adequately monitor CAES reservoir parameters at depth. The best available sensors were selected and adapted for use under expected ranges of reservoir conditions. The instrumentation design criteria required: suitable sensor accuracy; continuous monitoring capability; redundancy; maximum sensor integrity; contingency planning; and minimum cost-information ratio. Three wells will be instrumented: the injection/withdrawal (I/W) well and the two instrument wells. Sensors will be deployed by wireline suspension in both open and backfilled (with sand) wellbores. The sensors deployed in the I/W well will be retrievable; the instrument-well sensors will not.

  10. Process Parameter Optimization for Ultrasonic-assisted Osmotic Dehydration of Yacon%雪莲果超声波辅助渗透脱水工艺参数的优化

    Institute of Scientific and Technical Information of China (English)

    石启龙; 赵亚; 郑亚琴

    2011-01-01

    The current study aimed to use response surface methodology to optimize process parameters for the osmotic dehydration of yacon under the assistance of ultrasonic. A series of one-factor-at-a-time experiments were conducted to investigate the effects of thosmotic dehydration time and temperature, ultrasonic power, sucrose concentration and ultrasonic treatment time on water loss (WL) and solid gain (SG). Further, quadratic regression orthogonal rotation combination design was used to model WL, SG and WL/SG ratio with respect to thosmotic dehydration time and temperature, sucrose concentration and ultrasonic treatment time, and the three models developed were analyzed by response surface methodology. Ultrasonic assis- tance was found capable of enhancing the smotic dehydration of yacon. In terms of the importance in affecting WL, the four investigated process parameters ranked in the following order: osmotic dehydration temperature, osmotic dehydration time, sucrose concentration, and ultrasonic treatment time, and the order for affecting SG was osmotic dehydration time, ultrasonic treatment time, osmotic dehydration temperature, and sucrose concentration, and for affecting WL/SG ratio osmotic dehydration time, sucrose concentration, ultrasonic treatment time, and osmotic dehydration temperature. The optimal ultrasonicassisted osmotic dehydration parameters were osmotic dehydration temperature of 41 ℃, osmotic dehydration time of 1.7 h, sucrose concentration of 60.18 %, and ultrasonic treatment time of 35 min. Under the optimal process conditions, An average SG/WL ratio of 0.059 was achieved.%以渗透脱水温度、时间、蔗糖质量分数、超声波功率和处理时间为因素,以失水率(waterloss,WL)和固形物增加率(sugargain,SG)为指标,通过单因素试验,研究雪莲果的渗透脱水工艺参数。以渗透脱水温度、时间、蔗糖质量分数、超声波处理时间为因素,以WL、SG和二者比值(WL

  11. Mass Transfer During Osmotic Dehydration Using Acoustic Cavitation

    Institute of Scientific and Technical Information of China (English)

    孙宝芝; 淮秀兰; 姜任秋; 刘登瀛

    2005-01-01

    An experimental study on intensifying osmotic dehydration was carried out in a state of nature and with acoustic cavitation of different cavitating intensity (0.5A, 0.TA and 0.9A) respectively, in which the material is apple slice of 5 mm thickness. The result showed that acoustic cavitation remarkably enhanced the osmotic dehydration, and the water loss was accelerated with the increase of cavitating intensity. The water diffusivity coefficients ranged from 1.8 × 10-10 m2.s-1 at 0.5A to 2.6 × 10-10 m2.s-1 at 0.9A, and solute diffusivity coefficients ranged from 3.5×10-11 m2.s-1 at 0.5A to 4.6×10-11 m2.s-1 at 0.9A. On the basis of experiments, a mathematical model was established about mass transfer during osmotic dehydration, and the numerical simulation was carried out. The calculated results agree well with experimental data, and represent the rule of mass transfer during osmotic dehydration intensified by acoustic cavitation.

  12. Exclusively Breastfeeding and Hypernatremic Dehydration

    Directory of Open Access Journals (Sweden)

    MK Çağlar

    2005-08-01

    Full Text Available There is no doubt that breast-feeding is the best and safest way of feeding infants. Physiological weight loss occurs in the first two or three days of life, and the achievement of birth weight is expected towards the end of the first week. Hypernatremic dehydration may occur in exclusively breast-fed infants if milk supply is low during these first few days. It is not because of the high sodium content in breast milk; it is because of insufficient lactation. That is, the main cause of hypernatremic dehydration is water deprivation. There are many causes for low milk intake. Since most causes are preventable or able to be improved, mothers, particularly first time mothers, should receive more reassurance and practical advice in the technique of breast-feeding. Before their discharge from the hospital, they should be educated about the associated features of unsuccessful breast-feeding, such as going to the breast infrequently or for short times, infrequent passage of urine and stool, jaundice, lethargy, irritability and fever. Late diagnosis may cause catastrophic outcomes, such as a variety of palsies, apnea, bradycardia, seizures, hypertension, disseminated intravascular coagulation, necrotising enterocolitis after establishing full oral feeds, amputation of an extremity secondary to arterial thrombus, multiple cerebral infarctions, intracranial hemorrhages, massive intra ventricular hemorrhage, multiple dural thromboses. If babies are weighed on the day of the Guthrie test, those in the early onset of a disease and those who could not achieve their birth weight can be easily identified. The latter should be closely followed.

  13. Dehydrated melon containing antioxidants and calcium from grape juice

    Directory of Open Access Journals (Sweden)

    Hulda N. M. Chambi

    2016-11-01

    Full Text Available Background: Grape juice has a high antioxidant potential, capable of fighting oxidative processes in the body. The juice is mainly marketed in its concentrated form, which has a high content of glucose and fructose. The juice concentrate may then be used as an osmotic agent to dehydrated fruit with a relatively short shelf-life at room temperature, such as melon. The osmotic dehydration process can also be combined with conventional drying in order to further reduce the water activity (a w of the product. Finally, the antioxidant-rich melon meets the consumers’ demand for foods which contain ingredients that may impart health benefits. Results: Melon dehydrated by osmotic process at 200, 400 and 600 mbar, using grape juice concentrate (GJC, showed no significant differences in physical characteristics (a w , °Brix, and moisture content. Higher efficiency was observed when dehydration was performed at 200 mbar. After osmotic dehydration with GJC, both plasmolysis of the melon cells and an increase in intercellular spaces were observed by optical microscopy, with no negative impact on the mechanical properties (True stress, Hencky’s strain and deformability modulus. Calcium present in GJC was impregnated into the melon matrix, thus contributing with the mineral composition and mechanical properties of the final product. No significant differences were observed for the antioxidant capacity of melon dehydrated both with GJC and GJC followed by air-drying at 50 and 70°C. This demonstrates that it is possible to combine the two processes to obtain a product with intermediate moisture without decreasing its antioxidant capacity. The samples scored above the acceptable limit (>5 varying between like slightly to like moderately, resulting in a purchase intent with average scores between 3 (maybe/maybe not buy and 4 (probably would buy. Conclusions: A product with intermediate water activity, acidic, firm, high antioxidant capacity, rich in calcium

  14. Ethanol-Water Near-Azeotropic Mixture Dehydration by Compound Starch-Based Adsorbent

    Institute of Scientific and Technical Information of China (English)

    孙津生; 师明; 王文平

    2015-01-01

    Ethanol-water near-azeotropic mixture dehydration was investigated by formulated compound starch-based adsorbent(CSA), which consists of corn, sweet potato and foaming agent. The net retention time and separa-tion factor of water over ethanol were measured by inverse gas chromatography(IGC). Results indicated that water has a longer net retention time than ethanol and that low temperature is beneficial to this dehydration process. Or-thogonal test was conducted under different vapor feed flow rates, bed temperatures and bed heights, to obtain op-timal fixed-bed dehydration condition. Dynamic saturated adsorbance was also studied. It was found that CSA has the same water adsorption capacity(0.15 g/g)as some commercial molecular sieves. Besides, this biosorptive dehy-dration process was found to be the most energy-efficient compared with other ethanol purification processes.

  15. Processing and Quality Characteristics of Apple Slices under Simultaneous Infrared Dry-blanching and Dehydration with Intermittent Heating

    Science.gov (United States)

    This study investigated the effects of three processing parameters, e.g. product surface temperature, slice thickness and processing time, on blanching and dehydration characteristics of apple slices exposed to simultaneous infrared dry-blanching and dehydration (SIRDBD) with intermittent heating. A...

  16. Dehydration and thermal inactivation of Lactobacillus plantarum WCFS1: Comparing single droplet drying to spray and freeze drying

    NARCIS (Netherlands)

    Perdana, J.A.; Bereschenko, L.A.; Fox, M.B.; Kuperus, J.H.; Kleerebezem, M.; Boom, R.M.; Schutyser, M.A.I.

    2013-01-01

    We demonstrated that viability loss during single droplet drying can be explained by the sum of dehydration and thermal inactivation. For Lactobacillus plantarum WCFS1, dehydration inactivation predominantly occurred at drying temperatures below 45 °C and only depended on the moisture content. Above

  17. Spatiotemporal evolution of dehydration reactions in subduction zones (Invited)

    Science.gov (United States)

    Padron-Navarta, J.

    2013-12-01

    Large-scale deep water cycling takes place through subduction zones in the Earth, making our planet unique in the solar system. This idiosyncrasy is the result of a precise but unknown balance between in-gassing and out-gassing fluxes of volatiles. Water is incorporated into hydrous minerals during seafloor alteration of the oceanic lithosphere. The cycling of volatiles is triggered by dehydration of these minerals that release fluids from the subducting slab to the mantle wedge and eventually to the crust or to the deep mantle. Whereas the loci of such reactions are reasonably well established, the mechanisms of fluid migration during dehydration reactions are still barely known. One of the challenges is that dehydration reactions are dynamic features evolving in time and space. Experimental data on low-temperature dehydration reactions (i.e. gypsum) and numerical models applied to middle-crust conditions point to a complex spatiotemporal evolution of the dehydration process. The extrapolation of these inferences to subduction settings has not yet been explored but it is essential to understand the dynamism of these settings. Here I propose an alternative approach to tackle this problem through the textural study of high-pressure terrains that experienced dehydration reactions. Spatiotemporal evolution of dehydration reactions should be recorded during mineral nucleation and growth through variations in time and space of the reaction rate. Insights on the fluid migration mechanism could be inferred therefore by noting changes in the texture of prograde assemblages. The dehydration of antigorite in serpentinite is a perfect candidate to test this approach as it releases a significant amount of fluid and produces a concomitant porosity. Unusual alternation of equilibrium and disequilibrium textures observed in Cerro del Almirez (Betic Cordillera, S Spain)[1, 2] attest for a complex fluid migration pattern for one of the most relevant reactions in subduction zones

  18. Study on Electric Dehydration Parameters of Crude Oil Emulsion Containing Fracturing Fluid%含压裂液的原油乳状液电脱水参数研究

    Institute of Scientific and Technical Information of China (English)

    贺凤云; 李伊兰; 梁霄; 吕雅楠; 董静

    2016-01-01

    Crude oil containing fracturing fluid into the joint station has a great impact on the effect of electric dehydration in the “Five-in-One”. In this paper, by observing the oil-water separation interface features of electric dehydration, the temperature of electric dehydration was determined. Test experiments of the curve of electric dehydration of crude oil with different content fracturing fluid were carried out by using intelligent crude oil dehydration test instrument and moisture meter, the relation curves of electric field intensity, current and water cut in different time were obtained, meanwhile, effect of fracturing fluid content on the electric dehydration was analyzed, and the optimum operating parameters of the indoor electric dehydration were determined, which could provide a reliable theoretical basis for determination of the parameters of dewatering scheme in Longyi station.%针对含压裂液原油进入联合站对“五合一”的电脱效果产生很大影响的问题,通过观测电脱水油水分离界面特性,得出电脱温度,利用原油智能脱水试验仪和水分测定仪开展不同压裂液含量下电脱水曲线测试实验,得到了不同时间下电场强度、电流、含水率之间的关系曲线,同时分析了压裂液含量对电脱的影响规律,确定了室内电脱水最佳运行参数,为龙一联站内脱水方案参数的确定提供了可靠的理论基础。

  19. High Temperature μSR Experiments for Accelerator Developments

    Science.gov (United States)

    Ohmori, Chihiro; Koda, Akihiro; Miyake, Yasuhiro; Nishiyama, Kusuo; Shimomura, Koichiro; Schnase, Alexander; Ezura, Eiji; Hara, Keigo; Hasegawa, Katsushi; Nomura, Masahiro; Shimada, Taihei; Takata, Koji; Tamura, Fumihiko; Toda, Makoto; Yamamoto, Masanobu; Yoshii, Masahito

    High temperature μSR is a powerful technique to study magnetic materials. In J-PARC accelerator synchrotrons, the Rapid Cycling Synchrotron (RCS) and Main Ring (MR), a unique magnetic alloy-loaded cavity is used for the beam acceleration and much higher field gradient has been achieved. Such high field gradient cavities made a compact RCS possible by reducing the length for beam acceleration. Now, further upgrades of the J-PARC, RF cavities with higher RF voltage and less power loss in the magnetic core are needed for the MR. For the improvements of the magnetic property of magnetic alloy core, the high temperature μSR (muon Spin Rotation/Relaxation) was used to investigate the crystallization process of the material. Based on the measurement results, the test production of the large ring cores of a magnetic alloy, FT3L, was tried. The FT3L is the magnetic alloy which has two times better performance than the present one, FT3M. For the FT3L production, the magnetic annealing is needed to control the easy-magnetized axis of the crystalline. After the success of the test production, a mass production was started in the industry to replace all existing cavities in the MR. The first 5-cell FT3L cavity is assembled for the bench test before the installation in the accelerator tunnel. By the new cavities, the total RF voltage of J-PARC MR will be doubled to increase the beam power for neutrino experiment. In future, the cavities will be also used for the RCS to increase the beam power beyond 1 MW.

  20. DEHYDRATION AND SPRAYING OF BURITI PULP (Mauritia flexuosa L.: SHELF-LIFE EVALUATION

    Directory of Open Access Journals (Sweden)

    JAIME PAIVA LOPES AGUIAR

    Full Text Available ABSTRACT The present study aimed to process buriti fruits by dehydration and spraying and to evaluate their shelf-life in polyethylene plastic packaging at different storage temperatures. The edible part of the fruit was dehydrated, crushed and sieved for granule diameter standardization, packaged in polyethylene plastic packaging and stored at different temperatures 24°C (Ambient, 4°C (Cooling and -12°C (Freezer. Fresh and dehydrated fruits were analyzed for moisture, pH, acidity, total and reducing sugars, proteins, lipids, ashes, carbohydrates, energy, ß-carotene and retinol equivalent. Dehydrated and sprayed buriti was analyzed every 30 days for 150 days of storage for peroxide, acid and iodine indexes and also for microbiological parameters. The constituents that stood out both in fresh and dehydrated and sprayed fruits were: lipids, carbohydrates and consequently, energy and ß-carotene. In relation to shelf-life, all treatments presented good chemical and microbiological stability during the 150 days of storage period. It was concluded that dehydrated and sprayed buriti remained with good chemical and microbiological stability for at least 150 days of storage at temperatures of 4°C and -12°C. It is suggested that this product can be used as an ingredient in formulated foods aimed at supplementation of pro-vitamin A.

  1. Small Specimen Data from a High Temperature HFIR Irradiation Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Burchell, Timothy D [ORNL; McDuffee, Joel Lee [ORNL; Thoms, Kenneth R [ORNL

    2014-01-01

    The HTV capsule is a High Flux Isotope Reactor (HFIR) target-rod capsule designed to operate at very high temperatures. The graphite containing section of the capsule (in core) is approximately 18 inches (457.2 mm) long and is separated into eight temperature zones. The specimen diameters within each zone are set to achieve the desired gas gap and hence design temperature (900 C, 1200 C or 1500 C). The capsule has five zones containing 0.400 inch (10.16 mm) diameter specimens, two zones containing 0.350 inch (8.89 mm) diameter specimens and one zone containing 0.300 inch (7.62 mm) diameter specimens. The zones have been distributed within the experiment to optimize the gamma heating from the HFIR core as well as minimize the axial heat flow in the capsule. Consequently, there are two 900 C zones, three 1200 C zones, and three 1500 C zones within the HTV capsule. Each zone contains nine specimens 0.210 0.002 inches (5.334 mm) in length. The capsule will be irradiated to a peak dose of 3.17 displacements per atom. The HTV specimens include samples of the following graphite grades: SGL Carbon s NBG-17 and NBG-18, GrafTech s PCEA, Toyo Tanso s IG-110, Mersen s 2114 and the reference grade H-451 (SGL Carbon). As part of the pre-irradiation program the specimens were characterized using ASTM Standards C559 for bulk density, and ASTM C769 for approximate Young s modulus from the sonic velocity. The probe frequency used for the determination of time of flight of the ultrasonic signal was 2.25 MHz. Marked volume (specimen diameter) effects were noted for both bulk density (increased with increasing specimen volume or diameter) and Dynamic Young s modulus (decreased with increasing specimen volume or diameter). These trends are extended by adding the property vs. diameter data for unirradiated AGC-1 creep specimens (nominally 12.5 mm-diameter x 25.4 mm-length). The relatively large reduction in Dynamic Young s Modulus was surprising given the trend for increasing density

  2. Experiment to measure oxygen opacity at high density and temperature

    Science.gov (United States)

    Keiter, Paul; Mussack, Katie; Orban, Chris; Colgan, James; Ducret, Jean-Eric; Fontes, Christopher J.; Guzik, Joyce Ann; Heeter, Robert F.; Kilcrease, Dave; Le Pennec, Maelle; Mancini, Roberto; Perry, Ted; Turck-Chièze, Sylvaine; Trantham, Matt

    2017-06-01

    In recent years, there has been a debate over the abundances of heavy elements (Z >2) in the solar interior. Recent solar atmosphere models [Asplund 2009] find a significantly lower abundance for C, N, and O compared to models used roughly a decade ago. This discrepancy has led to an investigation of opacities through laboratory experiments and improved opacity models for many of the larger contributors to the sun’s opacity, including iron and oxygen. Recent opacity measurements of iron disagree with opacity model predictions [Bailey et al, 2015]. Although these results are still controversial, repeated scrutiny of the experiment and data has not produced a conclusive reason for the discrepancy. New models have been implemented in the ATOMIC opacity code for C, O and Fe to address the solar abundance issue [Colgan, 2013]. Armstrong et al [2014] have also implemented changes in the ATOMIC code for low-Z elements. However, no data currently exists to test the low-Z material models in the regime relevant to the solar convection zone. We present an experimental design using the opacity platform developed at the National Ignition Facility to study the oxygen opacity at densities and temperatures near the solar convection zone conditions.This work is funded by the U.S. DOE, through the NNSA-DS and SC-OFES Joint Program in HEDPLP, grant No. DE-NA0001840, and the NLUF Program, grant No. DE-NA0000850, and through LLE, University of Rochester by the NNSA/OICF under Agreement No. DE-FC52-08NA28302.

  3. Metal organic framework MIL-101(Cr) for dehydration reactions

    Indian Academy of Sciences (India)

    M Suresh; B David Raju; K S Rama Rao; K Raveendranath Reddy; M Lakshmi Kantam; Pavuluri Srinivasu

    2014-03-01

    Porous chromium terephthalate MIL-101 (Cr-MIL-101) has been prepared by direct method under hydrothermal conditions and characterized using X-ray diffraction, N2 sorption, TGA and FT-IR. The nitrogen adsorption-desorption isotherm shows that the Cr-MIL-101 possesses BET specific surface area of 2563 m2/g. Catalytic performance of Cr-MIL-101 in the dehydration of 1,4-butanediol and 1-phenylethanol is assessed under vapour phase conditions in the temperature range of 513-533 K and time on stream (TOS) at 513 K. Cr-MIL-101 demonstrates superior catalytic activity with conversion of 95% of 1-phenylethanol. Moreover, high surface area and nanocages with coordinated unsaturated sites of Cr-MIL-101 have allowed us to attain higher dehydrated products selectivity than Cr-supported activated carbon (Cr/AC), amberlyst-15 and HZSM-5 catalysts.

  4. Dust Ejection from Planetary Bodies by Temperature Gradients: Laboratory Experiments

    CERN Document Server

    Kelling, Thorben; Kocifaj, Miroslav; Klacka, Jozef; Reiss, Dennis

    2011-01-01

    Laboratory experiments show that dusty bodies in a gaseous environment eject dust particles if they are illuminated. We find that even more intense dust eruptions occur when the light source is turned off. We attribute this to a compression of gas by thermal creep in response to the changing temperature gradients in the top dust layers. The effect is studied at a light flux of 13 kW/(m*m) and 1 mbar ambient pressure. The effect is applicable to protoplanetary disks and Mars. In the inner part of protoplanetary disks, planetesimals can be eroded especially at the terminator of a rotating body. This leads to the production of dust which can then be transported towards the disk edges or the outer disk regions. The generated dust might constitute a significant fraction of the warm dust observed in extrasolar protoplanetary disks. We estimate erosion rates of about 1 kg/s for 100 m parent bodies. The dust might also contribute to subsequent planetary growth in different locations or on existing protoplanets which ...

  5. Intermediate-depth earthquake faulting by dehydration embrittlement with negative volume change

    Science.gov (United States)

    Jung, Haemyeong; Green, Harry W., II; Dobrzhinetskaya, Larissa F.

    2004-04-01

    Earthquakes are observed to occur in subduction zones to depths of approximately 680km, even though unassisted brittle failure is inhibited at depths greater than about 50km, owing to the high pressures and temperatures. It is thought that such earthquakes (particularly those at intermediate depths of 50-300km) may instead be triggered by embrittlement accompanying dehydration of hydrous minerals, principally serpentine. A problem with failure by serpentine dehydration is that the volume change accompanying dehydration becomes negative at pressures of 2-4GPa (60-120km depth), above which brittle fracture mechanics predicts that the instability should be quenched. Here we show that dehydration of antigorite serpentinite under stress results in faults delineated by ultrafine-grained solid reaction products formed during dehydration. This phenomenon was observed under all conditions tested (pressures of 1-6GPa temperatures of 650-820°C), independent of the sign of the volume change of reaction. Although this result contradicts expectations from fracture mechanics, it can be explained by separation of fluid from solid residue before and during faulting, a hypothesis supported by our observations. These observations confirm that dehydration embrittlement is a viable mechanism for nucleating earthquakes independent of depth, as long as there are hydrous minerals breaking down under a differential stress.

  6. Physiologic Basis for Understanding Quantitative Dehydration Assessment

    Science.gov (United States)

    2012-01-01

    Quantitative Dehydration Sb. GRANT NUMBER Assessment Sc. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Sd. PROJECT NUMBER Samuel Cheuvront; Robert Kenefick; Nisha...of the statistical prob- ability for dehydration. Semantic descriptors provide a scale that aligned with statistical probability to communicate the...cryoscopy. JAMA 1968;205:506–12. 30. Mange K, Matsuura D, Cizman B, Soto H, Ziyadeh FN, Goldfarb S, Neilson EG. Language guiding therapy: the case of

  7. Dehydration processes using membranes with hydrophobic coating

    Science.gov (United States)

    Huang, Yu; Baker, Richard W; Aldajani, Tiem; Ly, Jennifer

    2013-07-30

    Processes for removing water from organic compounds, especially polar compounds such as alcohols. The processes include a membrane-based dehydration step, using a membrane that has a dioxole-based polymer selective layer or the like and a hydrophilic selective layer, and can operate even when the stream to be treated has a high water content, such as 10 wt % or more. The processes are particularly useful for dehydrating ethanol.

  8. Rehydration with soft drink-like beverages exacerbates dehydration and worsens dehydration-associated renal injury.

    Science.gov (United States)

    García-Arroyo, Fernando E; Cristóbal, Magdalena; Arellano-Buendía, Abraham S; Osorio, Horacio; Tapia, Edilia; Soto, Virgilia; Madero, Magdalena; Lanaspa, Miguel A; Roncal-Jiménez, Carlos; Bankir, Lise; Johnson, Richard J; Sánchez-Lozada, Laura-Gabriela

    2016-07-01

    Recurrent dehydration, such as commonly occurs with manual labor in tropical environments, has been recently shown to result in chronic kidney injury, likely through the effects of hyperosmolarity to activate both vasopressin and aldose reductase-fructokinase pathways. The observation that the latter pathway can be directly engaged by simple sugars (glucose and fructose) leads to the hypothesis that soft drinks (which contain these sugars) might worsen rather than benefit dehydration associated kidney disease. Recurrent dehydration was induced in rats by exposure to heat (36°C) for 1 h/24 h followed by access for 2 h to plain water (W), a 11% fructose-glucose solution (FG, same composition as typical soft drinks), or water sweetened with noncaloric stevia (ST). After 4 wk plasma and urine samples were collected, and kidneys were examined for oxidative stress, inflammation, and injury. Recurrent heat-induced dehydration with ad libitum water repletion resulted in plasma and urinary hyperosmolarity with stimulation of the vasopressin (copeptin) levels and resulted in mild tubular injury and renal oxidative stress. Rehydration with 11% FG solution, despite larger total fluid intake, resulted in greater dehydration (higher osmolarity and copeptin levels) and worse renal injury, with activation of aldose reductase and fructokinase, whereas rehydration with stevia water had opposite effects. In animals that are dehydrated, rehydration acutely with soft drinks worsens dehydration and exacerbates dehydration associated renal damage. These studies emphasize the danger of drinking soft drink-like beverages as an attempt to rehydrate following dehydration.

  9. Microcrystalline hexagonal tungsten bronze. 2. Dehydration dynamics.

    Science.gov (United States)

    Luca, Vittorio; Griffith, Christopher S; Hanna, John V

    2009-07-06

    Low-temperature (25-600 degrees C) thermal transformations have been studied for hydrothermally prepared, microcrystalline hexagonal tungsten bronze (HTB) phases A(x)WO(3+x/2).zH(2)O as a function of temperature, where A is an exchangeable cation (in this case Na(+) or Cs(+)) located in hexagonal structural tunnels. Thermal treatment of the as-prepared sodium- and cesium-exchanged phases in air were monitored using a conventional laboratory-based X-ray diffractometer, while thermal transformations in vacuum were studied using synchrotron X-ray and neutron diffraction. Concurrent thermogravimetric, diffuse reflectance infrared (DRIFT), and (23)Na and (133)Cs magic angle spinning (MAS) NMR spectroscopic studies have also been undertaken. For the cesium variant, cell volume contraction occurred from room temperature to about 350 degrees C, the regime in which water was "squeezed" out of tunnel sites. This was followed by a lattice expansion in the 350-600 degrees C temperature range. Over the entire temperature range, a net thermal contraction was observed, and this was the result of an anisotropic change in the cell dimensions which included a shortening of the A-O2 bond length. These changes explain why Cs(+) ions are locked into tunnel positions at temperatures as low as 400 degrees C, subsequently inducing a significant reduction in Cs(+) extractability under low pH (nitric acid) conditions. The changing Cs(+) speciation as detected by (133)Cs MAS NMR showed a condensation from multiple Cs sites, presumably associated with differing modes of Cs(+) hydration in the tunnels, to a single Cs(+) environment upon thermal transformation and water removal. While similar lattice contraction was observed for the as-prepared sodium variant, the smaller radius of Na(+) caused it to be relatively easily removed with acid in comparison to the Cs(+) variant. From (23)Na MAS NMR studies of the parent material, complex Na(+) speciation was observed with dehydrated and various

  10. 21 CFR 73.40 - Dehydrated beets (beet powder).

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Dehydrated beets (beet powder). 73.40 Section 73... LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.40 Dehydrated beets (beet powder). (a) Identity. (1) The color additive dehydrated beets is a dark red powder prepared by dehydrating...

  11. Thin layer drying of wormwood ( Artemisia absinthium L.) leaves: dehydration characteristics, rehydration capacity and energy consumption

    Science.gov (United States)

    Beigi, Mohsen

    2017-08-01

    This study aimed at determining the influence of temperature on drying, rehydration and consumed energy characteristics of common wormwood leaves during thin layer drying. The experiments were carried out at temperatures of 50, 60 and 70 °C and a constant air velocity of 0.7 m s-1. The dehydration duration decreased significantly with increasing drying air temperature. The usefulness of five different mathematical models to simulate the experimental drying kinetics was evaluated and the Midilli model was found to be the best model for explaining the curves. Effective moisture diffusivity values were obtained to be in the range of 7.099 × 10-8-3.191 × 10-7 m2 s-1. Rehydration capacity of the dried leaves increased with increasing rehydration water temperature and decreasing drying air temperature. The specific energy consumption decreased with any increment in drying air temperature and varied from 17.64 to 32.09 kWh kg-1.

  12. Modelling of mass transfer kinetic in osmotic dehydration of kiwifruit

    Science.gov (United States)

    Jabrayili, Sharokh; Farzaneh, Vahid; Zare, Zahra; Bakhshabadi, Hamid; Babazadeh, Zahra; Mokhtarian, Mohsen; Carvalho, Isabel S.

    2016-04-01

    Osmotic dehydration characteristics of kiwifruit were predicted by different activation functions of an artificial neural network. Osmotic solution concentration (y1), osmotic solution temperature (y2), and immersion time (y3) were considered as the input parameters and solid gain value (x1) and water loss value (x2) were selected as the outlet parameters of the network. The result showed that logarithm sigmoid activation function has greater performance than tangent hyperbolic activation function for the prediction of osmotic dehydration parameters of kiwifruit. The minimum mean relative error for the solid gain and water loss parameters with one hidden layer and 19 nods were 0.00574 and 0.0062% for logarithm sigmoid activation function, respectively, which introduced logarithm sigmoid function as a more appropriate tool in the prediction of the osmotic dehydration of kiwifruit slices. As a result, it is concluded that this network is capable in the prediction of solid gain and water loss parameters (responses) with the correlation coefficient values of 0.986 and 0.989, respectively.

  13. Dehydration Influences Mood and Cognition: A Plausible Hypothesis?

    Directory of Open Access Journals (Sweden)

    David Benton

    2011-05-01

    Full Text Available The hypothesis was considered that a low fluid intake disrupts cognition and mood. Most research has been carried out on young fit adults, who typically have exercised, often in heat. The results of these studies are inconsistent, preventing any conclusion. Even if the findings had been consistent, confounding variables such as fatigue and increased temperature make it unwise to extrapolate these findings. Thus in young adults there is little evidence that under normal living conditions dehydration disrupts cognition, although this may simply reflect a lack of relevant evidence. There remains the possibility that particular populations are at high risk of dehydration. It is known that renal function declines in many older individuals and thirst mechanisms become less effective. Although there are a few reports that more dehydrated older adults perform cognitive tasks less well, the body of information is limited and there have been little attempt to improve functioning by increasing hydration status. Although children are another potentially vulnerable group that have also been subject to little study, they are the group that has produced the only consistent findings in this area. Four intervention studies have found improved performance in children aged 7 to 9 years. In these studies children, eating and drinking as normal, have been tested on occasions when they have and not have consumed a drink. After a drink both memory and attention have been found to be improved.

  14. Dehydration influences mood and cognition: a plausible hypothesis?

    Science.gov (United States)

    Benton, David

    2011-05-01

    The hypothesis was considered that a low fluid intake disrupts cognition and mood. Most research has been carried out on young fit adults, who typically have exercised, often in heat. The results of these studies are inconsistent, preventing any conclusion. Even if the findings had been consistent, confounding variables such as fatigue and increased temperature make it unwise to extrapolate these findings. Thus in young adults there is little evidence that under normal living conditions dehydration disrupts cognition, although this may simply reflect a lack of relevant evidence. There remains the possibility that particular populations are at high risk of dehydration. It is known that renal function declines in many older individuals and thirst mechanisms become less effective. Although there are a few reports that more dehydrated older adults perform cognitive tasks less well, the body of information is limited and there have been little attempt to improve functioning by increasing hydration status. Although children are another potentially vulnerable group that have also been subject to little study, they are the group that has produced the only consistent findings in this area. Four intervention studies have found improved performance in children aged 7 to 9 years. In these studies children, eating and drinking as normal, have been tested on occasions when they have and not have consumed a drink. After a drink both memory and attention have been found to be improved.

  15. Detecting Acoustic Emissions With/Without Dehydration of Serpentine Outside P-T Field of Conventional Brittle Failure

    Science.gov (United States)

    Jung, H.; Fei, Y.; Silver, P. G.; Green, H. W.

    2005-12-01

    It is currently thought that earthquakes cannot be triggered at depths greater than ~60 km by unassisted brittle failure or frictional sliding, but could be triggered by dehydration embrittlement of hydrous minerals (Raleigh and Paterson, 1965; Green and Houston, 1995; Kirby, 1995; Jung et al., 2004). Using a new multianvil-based system for detecting acoustic emissions with four channels at high pressure and high temperature that was recently developed (Jung et al., 2005), we tested this hypothesis by deforming samples of serpentine. We found that acoustic emissions were detected not only during/after the dehydration of serpentine, but even in the absence of dehydration. These emissions occurred at high pressure and high temperature, and thus outside pressure-temperature field of conventional brittle failure. Backscattered-electron images of microstructures of the post-run specimen revealed fault slip at elevated pressure, with offsets of up to ~500 μm, even without dehydration. Analysis of P-wave travel times from the four sensors confirmed that the acoustic emissions originated from within the specimen during fault slip. These observations suggest that earthquakes can be triggered by slip along a fault containing serpentine at significantly higher pressure and temperature conditions than that previously thought, even without dehydration. They are thus consistent with faulting mechanisms that appeal to dehydration embrittlement, as well as those that rely solely on the rheology of non-dehydrated serpentine.

  16. Modeling and Optimization of Catalytic Dehydration of Ethanol to Ethylene Using Central Composite Design

    Institute of Scientific and Technical Information of China (English)

    KONG Haining; QI Ershi; LI Gang; HE Shuguang; ZHANG Xian

    2009-01-01

    The central composite design in the modeling and optimization of catalytic dehydration of ethanol to ethylene was performed to improve the ethylene yield. A total of 20 experiments at random were conducted to in-vestigate the effect of reaction temperature, Si/Al ratios of H-ZSM-5 catalyst and liquid hourly space velocity (LHSV)on the ethylene yield. The results show that the relationship between ethylene yield and the three signifi-cant independent variables can be approximated by a nonlinear polynomial model, with R-squared of 99.9% and adjusted R-squared of 99.8%. The maximal response for ethylene yield is 93.4% under the optimal condition of 328 ℃, Si/Al ratio 85, and LHSV 3.8 h-1.

  17. Catalytic Dehydration of 4-Hydroxy-3-hexanone to 4-Hexen-3-one over HZSM-5 Zeolite

    Institute of Scientific and Technical Information of China (English)

    Huang Kai; Zheng Haitao; Tao Keyi

    2013-01-01

    A study on catalytic dehydration of 4-hydroxy-3-hexanone (HH) to 4-hexen-3-one (HO) was carried out through conversion of HH over HZSM-5 zeolite catalyst in a ifxed-bed reactor (FBR) operating under atmospheric pressure. The test indicated a relatively high activity of the HZSM-5 zeolite capable of achieving a HH conversion of 99.2% and a HO yield of 83.5%. Catalyst deactivation could be prevented by increasing the reaction temperature by 10℃ for every 20 h and adding 2.0% of piperidine in the feed. A catalyst stability test (for 100 h) in FBR showed that the catalyst was active even after 100 h of time-on-stream with HH conversion remaining at 99.2% and HO yield still reaching over 83.5%. Regenera-tion experiment showed that the regenerated catalyst demonstrated a catalytic performance comparable to the fresh one.

  18. Comparison Between the Continuous and Intermittent Heating Methods for Simultaneous Infrared Dry-Blanching and Dehydration of Apple Slices

    Science.gov (United States)

    Simultaneous infrared dry-blanching and dehydration (SIRDBD) can be operated in two heating modes, continuous and intermittent heating. Under continuous heating, infrared radiation intensity was kept constant while the product temperature remained constant under intermittent heating in this study. ...

  19. Experiment and calculation of reinforced concrete at elevated temperatures

    CERN Document Server

    Guo, Zhenhai

    2011-01-01

    Concrete as a construction material goes through both physical and chemical changes under extreme elevated temperatures. As one of the most widely used building materials, it is important that both engineers and architects are able to understand and predict its behavior in under extreme heat conditions. Brief and readable, this book provides the tools and techniques to properly analysis the effects of high temperature of reinforced concrete which will lead to more stable, safer structures. Based on years of the author's research, Reinforced Concrete at Elevated Temperatures four par

  20. Fe and S redox states during serpentinite dehydration in subduction settings

    Science.gov (United States)

    Merkulova, Margarita; Munoz, Manuel; Vidal, Olivier; Brunet, Fabrice

    2016-04-01

    Serpentinite rocks formed by hydrothermal alteration of oceanic peridotites compose ~70% of the oceanic crust (Hacker et al., 2003), which later sinks into subduction zone and experiences metamorphic reactions. Serpentinites carry ~12 wt.% H2O and thereby introduces large amount of water in the upper mantle during dehydration in subduction (Ulmer and Trommsdorff, 1995). In addition, serpentinites are known to contain such minerals as magnetite Fe3O4 and pyrite FeS2 in the amounts of ~5 wt.% (Debret et al., 2014) and 1.5 wt.% (Alt et al., 2013), respectively. During metamorphic reactions speciations of Fe and S are tended to change and affect oxygen fugacity. In turn, oxygen fugacity influences the mobility of fluid mobile elements and metals (Pokrovski and Dubrovinsky 2011). We characterized Fe and S speciation and amount of released water during serpentinite dehydration at different temperature and pressure intervals along a subduction zone. We performed three sets of experiments using piston-cylinder apparatus. Three different starting materials composed of powdered mineral mixtures were used: Fe(III)-antigorite (atg), atg + magnetite, atg + pyrite. Experimental runs were performed at 2 GPa, between 400 and 900°C. Experimental products were first characterized by X-ray diffraction and electron microprobe. Speciation of Fe and S were characterized by X-ray absorption spectroscopy (XANES) at iron and sulfur K-edges. In addition, thermodynamic modeling was applied in this work with constrained thermodynamical data for Fe-bearing antigorite. The results demonstrate the continuous dehydration of serpentinites with the main water releasing domain between 670 and 700°C, which is happening due to breakdown of antigorite. Fe K-edge XANES measurements show that the amount of ferric iron dramatically decreases between 550-650°C, leading to a release of free oxygen in the system. As a result, we show that the first fluids released from the slab dehydration most likely

  1. ANALISIS PERMEASI AIR PADA DEHIDRASI OSMOSIS PEPAYA (Carica papaya) Water Permeation Analysis on Osmotic Dehydration of Papaya (Carica papaya)

    OpenAIRE

    Sang Kompiang Wirawan; Natalia Anasta

    2013-01-01

    Fruit preservation using low temperature drying is commonly initiated by osmotic dehydration process. The osmotic time is strongly influenced by the water permeation from the fruit to the osmotic solution. This research aimed to study the osmotic dehydration process of papaya by finding out the permeation rate of water to the osmotic solution across a semi permeable membrane. The effect of temperature and osmotic solution concentration on the permeation rate were also observed. The osmotic te...

  2. Handbook of high-temperature superconductivity theory and experiment

    CERN Document Server

    Brooks, James S

    2007-01-01

    Since the 1980s, a general theme in the study of high-temperature superconductors has been to test the BCS theory and its predictions against new data. At the same time, this process has engendered new physics, new materials, and new theoretical frameworks. Remarkable advances have occurred in sample quality and in single crystals, in hole and electron doping in the development of sister compounds with lower transition temperatures, and in instruments to probe structure and dynamics. Handbook of High-Temperature Superconductvity is a comprehensive and in-depth treatment of both experimental and theoretical methodologies by the the world's top leaders in the field. The Editor, Nobel Laureate J. Robert Schrieffer, and Associate Editor James S. Brooks, have produced a unified, coherent work providing a global view of high-temperature superconductivity covering the materials, the relationships with heavy-fermion and organic systems, and the many formidable challenges that remain.

  3. Twin formation in hematite during dehydration of goethite

    Science.gov (United States)

    Saito, Genki; Kunisada, Yuji; Nomura, Takahiro; Sakaguchi, Norihito; Akiyama, Tomohiro

    2016-11-01

    Twin formation in hematite during dehydration was investigated using X-ray diffraction, electron diffraction, and high-resolution transmission electron microscopy (TEM). When synthetic goethite was heated at different temperatures between 100 and 800 °C, a phase transformation occurred at temperatures above 250 °C. The electron diffraction patterns showed that the single-crystalline goethite with a growth direction of [001]G was transformed into hematite with a growth direction of [100]H. Two non-equivalent structures emerged in hematite after dehydration, with twin boundaries at the interface between the two variants. As the temperature was increased, crystal growth occurred. At 800 °C, the majority of the twin boundaries disappeared; however, some hematite particles remained in the twinned variant. The electron diffraction patterns and high-resolution TEM observations indicated that the twin boundaries consisted of crystallographically equivalent prismatic (100) (010), and (1bar{1}0) planes. According to the total energy calculations based on spin-polarized density functional theory, the twin boundary of prismatic (100) screw had small interfacial energy (0.24 J/m2). Owing to this low interfacial energy, the prismatic (100) screw interface remained after higher-temperature treatment at 800 °C.

  4. A Delay Time Measurement of ULTRAS (Ultra-high Temperature Ultrasonic Response Analysis System) for a High Temperature Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Koo, Kil Mo; Kim, Sang Baik [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2010-05-15

    The temperature measurement of very high temperature core melt is of importance in a high temperature as the molten pool experiment in which gap formation between core melt and the reactor lower head, and the effect of the gap on thermal behavior are to be measured. The existing temperature measurement techniques have some problems, which the thermocouple, one of the contact methods, is restricted to under 2000 .deg. C, and the infrared thermometry, one of the non-contact methods, is unable to measure an internal temperature and very sensitive to the interference from reacted gases. In order to solve these problems, the delay time technique of ultrasonic wavelets due to high temperature has two sorts of stage. As a first stage, a delay time measurement of ULTRAS (Ultra-high Temperature Ultrasonic Response Analysis System) is suggested. As a second stage, a molten material temperature was measured up to 2300 .deg. C. Also, the optimization design of the UTS (ultrasonic temperature sensor) with persistence at the high temperature was suggested in this paper. And the utilization of the theory suggested in this paper and the efficiency of the developed system are performed by special equipment and some experiments supported by KRISS (Korea Research Institute of Standard and Science)

  5. Understanding the responses of Saccharomyces cerevisiae yeast strain during dehydration processes using synchrotron infrared spectroscopy.

    Science.gov (United States)

    Nguyen, T D; Guyot, S; Pénicaud, C; Passot, S; Sandt, C; Fonseca, F; Saurel, R; Husson, F

    2017-08-24

    For the first time, synchrotron infrared spectroscopy was performed on yeast during dehydration processes in real time with simultaneously controlled relative humidity and temperature. This led us to investigate the biochemical modification in relation to the dehydration of Saccharomyces cerevisiae. The correlation between the hydration level and yeast survival was observed. Following the test conditions, the modification of the protein structure was observed. However, no evident modification of the lipid composition resulting from dehydration was observed. Furthermore, the results showed that the medium rich in nutrients and glutathione precursors can improve yeast survival during dehydration at 45 °C. This could be related to the high relative amounts of CH3 groups in the lipid composition assigned to the low lipid oxidation level in this case. Our work demonstrated the feasibility of using S-FTIR for investigating yeast responses to dehydration processes in real time. This method can be used for understanding the effect of dehydration/rehydration on the biochemical modification of yeast.

  6. Exercise-induced dehydration does not alter time trial or neuromuscular performance.

    Science.gov (United States)

    Stewart, C J; Whyte, D G; Cannon, J; Wickham, J; Marino, F E

    2014-08-01

    This study examined the effect of exercise-induced dehydration by ~4% body mass loss on 5-km cycling time trial (TT) performance and neuromuscular drive, independent of hyperthermia. 7 active males were dehydrated on 2 occasions, separated by 7 d. Participants remained dehydrated (DEH, -3.8±0.5%) or were rehydrated (REH, 0.2±0.6%) over 2 h before completing the TT at 18-25 °C, 20-30% relative humidity. Neuromuscular function was determined before dehydration and immediately prior the TT. The TT started at the same core temperature (DEH, 37.3±0.3°C; REH, 37.0±0.2 °C (P>0.05). Neither TT performance (DEH, 7.31±1.5 min; REH, 7.10±1.3 min (P>0.05)) or % voluntary activation were affected by dehydration (DEH, 88.7±6.4%; REH, 90.6±6.1% (P>0.05)). Quadriceps peak torque was significantly elevated in both trials prior to the TT (Pperformance and neuromuscular function are not reduced by dehydration, independent of hyperthermia.

  7. 新生儿腹泻脱水60例治疗观察与体会%Therapeutic observation and experience of 60 cases of neonatal diarrhea and dehydration

    Institute of Scientific and Technical Information of China (English)

    王刚

    2015-01-01

    目的:新生儿腹泻是临床最常见的消化道疾病。新生儿腹泻不仅影响新生儿的营养物质吸收,妨碍生长发育,也可因急性腹泻丢失大量的水和电解质,引起脱水、酸中毒和电解质平衡紊乱及血容量降低,甚至危及生命。收治新生儿腹泻脱水患者60例,采用纠正脱水和渗透压失常;调节水-电解质平衡和酸碱平衡;对因和对症治疗等治疗措施,取得较满意的效果,避免了腹泻引起的多种并发症(休克、低血钾、低血钙、坏死性肠炎、败血症和死亡等)。%Neonatal diarrhea is the most common clinical diseases of digestive tract.Neonatal diarrhea affected not only the absorption of nutrients in neonates,interference with the growth and development,and patients also could lose a lot of water and electrolyte because of acute diarrhea,which would cause dehydration,acidosis and electrolyte balance disorder and blood volume reduced,or even life-threatening.60 patients with neonatal diarrhea were selected.They were given correct dehydration and osmotic pressure of arrhythmia,regulation of water electrolyte balance and acid-base balance,etiological treatment and symptomatic treatment and so on,and treatment effect was satisfactory.It could avoid the complications caused by diarrhoea(shock, low blood potassium,hypocalcemia,necrotic enteritis,sepsis and death).

  8. Mechanisms of aerobic performance impairment with heat stress and dehydration.

    Science.gov (United States)

    Cheuvront, Samuel N; Kenefick, Robert W; Montain, Scott J; Sawka, Michael N

    2010-12-01

    Environmental heat stress can challenge the limits of human cardiovascular and temperature regulation, body fluid balance, and thus aerobic performance. This minireview proposes that the cardiovascular adjustments accompanying high skin temperatures (T(sk)), alone or in combination with high core body temperatures (T(c)), provide a primary explanation for impaired aerobic exercise performance in warm-hot environments. The independent (T(sk)) and combined (T(sk) + T(c)) effects of hyperthermia reduce maximal oxygen uptake (Vo(2max)), which leads to higher relative exercise intensity and an exponential decline in aerobic performance at any given exercise workload. Greater relative exercise intensity increases cardiovascular strain, which is a prominent mediator of rated perceived exertion. As a consequence, incremental or constant-rate exercise is more difficult to sustain (earlier fatigue) or requires a slowing of self-paced exercise to achieve a similar sensation of effort. It is proposed that high T(sk) and T(c) impair aerobic performance in tandem primarily through elevated cardiovascular strain, rather than a deterioration in central nervous system (CNS) function or skeletal muscle metabolism. Evaporative sweating is the principal means of heat loss in warm-hot environments where sweat losses frequently exceed fluid intakes. When dehydration exceeds 3% of total body water (2% of body mass) then aerobic performance is consistently impaired independent and additive to heat stress. Dehydration augments hyperthermia and plasma volume reductions, which combine to accentuate cardiovascular strain and reduce Vo(2max). Importantly, the negative performance consequences of dehydration worsen as T(sk) increases.

  9. High-Temperature Cuprate Superconductors Experiment, Theory, and Applications

    CERN Document Server

    Plakida, Nikolay Maksimilianovich

    2010-01-01

    High-Temperature Cuprate Superconductors provides an up-to-date and comprehensive review of the properties of these fascinating materials. The essential properties of high-temperature cuprate superconductors are reviewed on the background of their theoretical interpretation. The experimental results for structural, magnetic, thermal, electric, optical and lattice properties of various cuprate superconductors are presented with respect to relevant theoretical models. A critical comparison of various theoretical models involving strong electron correlations, antiferromagnetic spin fluctuations, phonons and excitons provides a background for understanding of the mechanism of high-temperature superconductivity. Recent achievements in their applications are also reviewed. A large number of illustrations and tables gives valuable information for specialists. A text-book level presentation with formulation of a general theory of strong-coupling superconductivity will help students and researches to consolidate their...

  10. Comparison of three methods for natural gas dehydration

    Institute of Scientific and Technical Information of China (English)

    Michal Netusil; Pavel Ditl

    2011-01-01

    This paper compares three methods for natural gas dehydration that are widely applied in industry:(1) absorption by triethylene glycol,(2)adsorption on solid desiccants and (3) condensation.A comparison is made according to their energy demand and suitability for use.The energy calculations are performed on a model where 105 Nm3/h water saturated natural gas is processed at 30 ℃.The pressure of the gas varies from 7 to 20 MPa.The required outlet concentration of water in natural gas is equivalent to the dew point temperature of - 10 ℃ at gas pressure of 4 MPa.

  11. Nutrition for the marathon and other endurance sports: environmental stress and dehydration.

    Science.gov (United States)

    Murray, R

    1992-09-01

    1) During exercise, the body's ability to safely regulate internal temperature is influenced by the environment, exercise intensity, clothing, and the athlete's level of fitness and acclimation. 2) Effective thermoregulation during exercise in the heat requires the evaporation of sweat. The onset of sweating during exercise is triggered by an increase in core body temperature. 3) Dehydration compromises cardiovascular and thermoregulatory function, limits physical work capacity, and increases the risk of heat-related health problems. 4) Physiological and behavioral adaptations help the body cope with the combined demands imposed by exercise and environment. 5) Ad libitum fluid intake is insufficient to protect against dehydration.

  12. Fate of Foodborne Pathogens During Osmotic Dehydration and Subsequent Storage of Apples.

    OpenAIRE

    Ramasamy, Thilahavathy

    2003-01-01

    The fate of E. coli O157:H7 and Salmonella spp. during osmotic dehydration of apples was determined at different processing temperatures, times and calcium chloride (CaCl2) concentrations. Apple slices were inoculated to achieve an 8 log CFU/ apple slice concentration of a five strain mixture of E. coli O157:H7 or Salmonella spp. and were soaked in sucrose solutions (60% w/w). In the first study, apple slices were subjected to osmotic dehydration at three different temperatures: 20°C, 45°C ...

  13. Dehydration affects cerebral blood flow but not its metabolic rate for oxygen during maximal exercise in trained humans

    DEFF Research Database (Denmark)

    Trangmar, Steven J; Chiesa, Scott T; Stock, Christopher G

    2014-01-01

    cerebral artery velocity (MCA Vmean), arterial-venous differences and blood temperature in 10 trained males during incremental cycling to exhaustion in the heat (35°C) in control, dehydrated and rehydrated states. Dehydration reduced body mass (75.8 ± 3 vs. 78.2 ± 3 kg), increased internal temperature (38......Intense exercise is associated with a reduction in cerebral blood flow (CBF), but regulation of CBF during strenuous exercise in the heat with dehydration is unclear. We assessed internal (ICA) and common carotid artery (CCA) haemodynamics (indicative of CBF and extra-cranial blood flow), middle...... venous noradrenaline, and falling arterial carbon dioxide tension (P aCO 2) (R(2) ≥ 0.41, P ≤ 0.01) whereas CCA flow and conductance were related to elevated blood temperature. In conclusion, dehydration accelerated the decline in CBF by decreasing P aCO 2 and enhancing vasoconstrictor activity. However...

  14. Effects of a carbohydrate-electrolyte beverage on blood viscosity after dehydration in healthy adults

    Institute of Scientific and Technical Information of China (English)

    CHANG Cui-qing; CHEN Yan-bo; CHEN Zhi-min; ZHANG Lan-tao

    2010-01-01

    Background The consumption of carbohydrate-electrolyte beverages (CEs) has been known to be more effective than plain water for recovery from dehydration. This phenomenon suggests that the ingestion of CEs after dehydration is better than water for maintaining body fluid and plasma volume, and for the recovery from hemoconcentration and high blood viscosity as well. High blood viscosity causes infarction and other cardiovascular events. In this study, CE was compared with water and tea for the ability to reduce increased blood viscosity after dehydration.Methods A crossover random control study was conducted to assess the effectiveness of three beverages for rehydration and decreasing of blood viscosity. Following exercise-induced dehydration of 2.2% of body weight in a permanent warm environment, 10 male subjects rested in a thermoneutral environment for 3 hours (rehydration period,REP). The subjects ingested test beverages equal to their body weight loss during the first 20 minutes in REP. Blood and urine samples were obtained throughout the experiments to assess the rehydration effect.rate was significantly greater for CE ((77.0+3.9)%) than water ((61.2±3.4)%) and tea ((60.5±3.7)%) for 3 hours of rest in REP.Conclusions The recovery from high blood viscosity induced by dehydration was higher with CE consumption than with water or tea. These results suggest that CE is useful for normalizing increased blood viscosity due to exercise-induced dehydration.

  15. Precision dosimetry system suited for low temperature radiation damage experiments

    DEFF Research Database (Denmark)

    Andersen, H.H.; Hanke, C.C.; Sørensen, H.

    1967-01-01

    A calorimetric system for dosimetry on a beam of charged particles is described. The calorimeter works at liquid helium temperature. The total dose may be measured with an accuracy of 0.3%, and the dose per area with 0.4%. No theoretical corrections are needed. © 1967 The American Institute...

  16. Catalytic Ethanol Dehydration over Different Acid-activated Montmorillonite Clays.

    Science.gov (United States)

    Krutpijit, Chadaporn; Jongsomjit, Bunjerd

    2016-01-01

    In the present study, the catalytic dehydration of ethanol to obtain ethylene over montmorillonite clays (MMT) with mineral acid activation including H2SO4 (SA-MMT), HCl (HA-MMT) and HNO3 (NA-MMT) was investigated at temperature range of 200 to 400°C. It revealed that HA-MMT exhibited the highest catalytic activity. Ethanol conversion and ethylene selectivity were found to increase with increased reaction temperature. At 400°C, the HA-MMT yielded 82% of ethanol conversion having 78% of ethylene yield. At lower temperature (i.e. 200 to 300°C), diethyl ether (DEE) was a major product. The highest activity obtained from HA-MMT can be attributed to an increase of weak acid sites and acid density by the activation of MMT with HCl. It can be also proven by various characterization techniques that in most case, the main structure of MMT did not alter by acid activation (excepted for NA-MMT). Upon the stability test for 72 h during the reaction, the MMT and HA-MMT showed only slight deactivation due to carbon deposition. Hence, the acid activation of MMT by HCl is promising to enhance the catalytic dehydration of ethanol.

  17. Process variables in the osmotic dehydration of sliced peaches

    Directory of Open Access Journals (Sweden)

    Sílvia Pimentel Marconi Germer

    2010-12-01

    Full Text Available This paper evaluated the influence of temperature and concentration of the sucrose syrup on the pre-osmotic dehydration of peaches. Physical (colour and texture and chemical variables (soluble solid content; total sugar, reducing and non-reducing sugar contents; and titratable acidity were investigated, as well as the osmotic dehydration parameters (loss of weight and water; solids incorporation. An experimental central composite design was employed varying the temperature (from 30 to 50 ºC and concentration (from 45 to 65 ºBrix and maintaining the syrup to fruit ratio (4:1, process time (4 hours, and format (slices. The degree of acceptance was used in the sensory analysis evaluating the following characteristics: appearance, taste, texture, colour, and overall quality using a hedonic scale. The results were modelled using the Statistica program (v. 6.0 and the Response Surface Methodology. The mathematical models of the following dimensionless variations yielded significant (p < 0.05 and predictive results: soluble solids content, total and non-reducing sugar contents, titratable acidity, colour parameter L*, and water loss. The models of the attributes colour and appearance yielded significant (p < 0.10 but not predictive results. Temperature was the prevalent effect in the models. The process conditions in the range from 50 to 54.1 ºC and from 45 to 65 ºBrix led to greater water losses and better sensory performances.

  18. Slow slip generated by dehydration reaction coupled with slip-induced dilatancy and thermal pressurization

    Science.gov (United States)

    Yamashita, Teruo; Schubnel, Alexandre

    2016-05-01

    Sustained slow slip, which is a distinctive feature of slow slip events (SSEs), is investigated theoretically, assuming a fault embedded within a fluid-saturated 1D thermo-poro-elastic medium. The object of study is specifically SSEs occurring at the down-dip edge of seismogenic zone in hot subduction zones, where mineral dehydrations (antigorite, lawsonite, chlorite, and glaucophane) are expected to occur near locations where deep slow slip events are observed. In the modeling, we introduce dehydration reactions, coupled with slip-induced dilatancy and thermal pressurization, and slip evolution is assumed to interact with fluid pressure change through Coulomb's frictional stress. Our calculations show that sustained slow slip events occur when the dehydration reaction is coupled with slip-induced dilatancy. Specifically, slow slip is favored by a low initial stress drop, an initial temperature of the medium close to that of the dehydration reaction equilibrium temperature, a low permeability, and overall negative volume change associated with the reaction (i.e., void space created by the reaction larger than the space occupied by the fluid released). Importantly, if we do not assume slip-induced dilatancy, slip is accelerated with time soon after the slip onset even if the dehydration reaction is assumed. This suggests that slow slip is sustained for a long time at hot subduction zones because dehydration reaction is coupled with slip-induced dilatancy. Such slip-induced dilatancy may occur at the down-dip edge of seismogenic zone at hot subduction zones because of repetitive occurrence of dehydration reaction there.

  19. Room Temperature Experiments with a Macroscopic Sapphire Mechanical Oscillator

    Science.gov (United States)

    Bourhill, Jeremy; Ivanov, Eugene; Tobar, Micahel

    2015-03-01

    We present initial results from a number of experiments conducted on a 0.53 kg sapphire ``dumbbell'' crystal. Mechanical motion of the crystal structure alters the dimensions of the crystal, and the induced strain changes the permittivity. These two effects frequency modulate resonant microwave whispering gallery modes, simultaneously excited within the crystal. A novel microwave readout system is described allowing extremely low noise measurements of this frequency modulation with a phase noise floor of -160 dBc/Hz at 100 kHz, near our modes of interest. Fine-tuning of the crystal's suspension have allowed for the optimisation of mechanical Q-factors in preparation for cryogenic experiments, with a value of 8 x 107 achieved so far. Finally, results are presented that demonstrate the excitation of mechanical modes via radiation pressure force. These are all important steps towards the overall goal of the experiment; to cool a macroscopic device to the quantum ground state.

  20. Undercooling experiments in a high temperature differential scanning calorimeter

    Energy Technology Data Exchange (ETDEWEB)

    Baricco, M.; Ferrari, E.; Battezzati, L. [Univ. di Torino (Italy)

    1996-12-31

    Several samples of metals and alloys have been undercooled during scanning in a high temperature DSC. Liquid Ni was undercooled of about 230 K when previously fluxed in molten B{sub 2}O{sub 3}. From enthalpy data of melting and solidification as a function of temperature, the excess heat capacity of liquid metals and alloys was evaluated. The specific heat of the liquid is definitely higher than that of the corresponding crystalline phases for glass-forming alloys, whereas it is close to that of the solid for pure metals. The Ni-B system has been studied in detail around the Ni-Ni{sub 3}B eutectic. On undercooling, a new metastable phase (Ni{sub 23}B{sub 6}) was produced. A metastable Ni-B phase diagram has been drawn using data of thermal analysis of several alloys containing the metastable phase.

  1. Parameterization of temperature and spectral distortions in future CMB experiments

    Energy Technology Data Exchange (ETDEWEB)

    Pitrou, Cyril; Stebbins, Albert

    2014-10-15

    CMB spectral distortions are induced by Compton collisions with electrons. We review the various schemes to characterize the anisotropic CMB with a non-Planckian spectrum. We advocate using logarithmically averaged temperature moments as the preferred language to describe these spectral distortions, both for theoretical modeling and observations. Numerical modeling is simpler, the moments are frame-independent, and in terms of scattering the mode truncation is exact.

  2. OPTIMIZATION OF DEHYDRATION CONDITIONS FOR ISOPROPYL ALCOHOL – WATER MIXTURE USING OXIDIZED POTATO STARCH

    Directory of Open Access Journals (Sweden)

    P.C.N EJIKEME

    2012-12-01

    Full Text Available This study investigated the possibility of dehydrating Isopropyl Alcohol – water mixture using oxidized starch from potato. The starch was modified using calcium hypochlorite. Central composite design was used to determine the effects of the four dehydrating variables; temperature, contact time, initial concentration of the isopropyl alcohol water solution and the adsorbent/solution ratio on the final concentration of the isopropyl alcohol water mixture. Based on the central composite design, a quadratic verses 2 factor interaction model was developed. The significant factors on the experimental design response were identified from the analysis of variance. The optimum conditions for the dehydration reaction were obtained by using temperature of 35oC, time of 40 minutes, adsorbent/solution ratio of 1:4 and initial concentration of 40% which resulted in finalconcentration of 43.968%.

  3. Mass transfer and microbiological profile of pork meat dehydrated in two different osmotic solutions

    Directory of Open Access Journals (Sweden)

    Plavšić Dragana V.

    2012-01-01

    Full Text Available The effects of osmotic dehydration on mass transfer properties and microbiological profile were investigated in order to determine the usefulness of this technique as pre-treatment for further treatment of meat. Process was studied in two solutions (sugar beet molasses, and aqueous solution of sodium chloride and sucrose, at two temperatures (4 and 22°C at atmospheric pressure. The most significant parameters of mass transfer were determined after 300 minutes of the dehydration. The water activity (aw values of the processed meat were determined, as well as the change of the microbiological profile between the fresh and dehydrated meat. At the temperature of 22°C the sugar beet molasses proved to be most suitable as an osmotic solution, despite the greater viscosity.

  4. Poorest countries experience earlier anthropogenic emergence of daily temperature extremes

    Science.gov (United States)

    Harrington, Luke J.; Frame, David J.; Fischer, Erich M.; Hawkins, Ed; Joshi, Manoj; Jones, Chris D.

    2016-05-01

    Understanding how the emergence of the anthropogenic warming signal from the noise of internal variability translates to changes in extreme event occurrence is of crucial societal importance. By utilising simulations of cumulative carbon dioxide (CO2) emissions and temperature changes from eleven earth system models, we demonstrate that the inherently lower internal variability found at tropical latitudes results in large increases in the frequency of extreme daily temperatures (exceedances of the 99.9th percentile derived from pre-industrial climate simulations) occurring much earlier than for mid-to-high latitude regions. Most of the world’s poorest people live at low latitudes, when considering 2010 GDP-PPP per capita; conversely the wealthiest population quintile disproportionately inhabit more variable mid-latitude climates. Consequently, the fraction of the global population in the lowest socio-economic quintile is exposed to substantially more frequent daily temperature extremes after much lower increases in both mean global warming and cumulative CO2 emissions.

  5. Combined effect of heat stress, dehydration and exercise on neuromuscular function in humans.

    Science.gov (United States)

    Ftaiti, F; Grélot, L; Coudreuse, J M; Nicol, C

    2001-01-01

    This study examined the combined effect of exercise induced hyperthermia and dehydration on neuromuscular function in human subjects. Six trained male runners ran for 40 min on a treadmill at 65% of their maximal aerobic velocity while wearing a tracksuit covered with an impermeable jacket and pants to impair the evaporation of sweat. These stressful experimental running conditions led the runners to a physiological status close to exhaustion. On average, the 40 min run ended at a heart rate of 196 (SD 8) beats.min-1, a tympanic temperature of 40 (SD 0.3) degrees C and with a loss of body mass of 2 (SD 0.5)%. Pre- and post-running strength tests included measurements of maximal knee extension and flexion torques in both isometric and isokinetic (at 60 and 240 degrees.s-1) conditions. A 20 s endurance test at 240 degrees.s-1 was also performed. Surface electromyographic (EMG) activity was recorded from six knee extensor and flexor muscles during the entire protocol. The treadmill run led to clear decrements in maximal extension torque and EMG activity both in isometric and at the slowest isokinetic velocity (60 degrees.s-1). However, no differences in these parameters were observed at 240 degrees.s-1. Furthermore, the EMG patterns of the major knee extensor and flexor muscles remained remarkably stable during the treadmill run. These results demonstrate that the exercise-induced hyperthermia and dehydration in the present experiments had only minor effects on the neuromuscular performance. However, it is also suggested that high internal body temperature per se could limit the production of high force levels.

  6. Advanced Colloids Experiment (Temperature Controlled) - ACE-T6

    Science.gov (United States)

    Meyer, William V.; Sicker, Ronald J.; Bailey, Kelly; Eustace, John; Lynch, Matthew

    2017-01-01

    Increment 53 - 54 Science Symposium presentation of Advanced Colloids Experiment (ACE-T6) to RPO. The purpose of this event is for Principal Investigators to present their science objectives, testing approach, and measurement methods to agency scientists, managers, and other investigators.

  7. Advanced Colloids Experiment (Temperature Controlled) - ACE-T9

    Science.gov (United States)

    Marr, David W. M.; Meyer, William V.; Sicker, Ronald; Bailey, Kelly; Eustace, John G.

    2017-01-01

    Increment 53 - 54 Science Symposium presentation of Advanced Colloids Experiment (ACE-T9) to RPO. The purpose of this event is for Principal Investigators to present their science objectives, testing approach, and measurement methods to agency scientists, managers, and other investigators.

  8. Operational experience with room temperature continuous wave accelerator structures

    Science.gov (United States)

    Alimov, A. S.; Ishkhanov, B. S.; Piskarev, I. M.; Shvedunov, V. I.; Tiunov, A. V.

    1993-05-01

    The paper reports the results of the computer simulation of parameters of the on-axis coupled accelerator structure for the continuous wave racetrack microtron. The operational experience with the accelerating sections on the basis of the on-axis coupled structure is described.

  9. Effect of water or saline intake on heat-induced limb vasodilation in dehydrated baboons.

    Science.gov (United States)

    Ryan, K L; Proppe, D W

    1990-02-01

    Dehydration markedly attenuates the increase in hindlimb blood flow elicited by environmental heating (EH) in baboons. This study sought to determine the importance of gradually produced increases in body fluid osmolality and decreases in body fluid volume in producing this attenuation. The hindlimb blood flow increases during EH of seven unanesthetized chronically instrumented baboons were examined during euhydration, dehydration (64-68 h of water deprivation), and after ad libitum oral rehydration with either water or a hyperosmotic saline solution. EH consisted of acute exposure to ambient temperatures of 38-42 degrees C until internal temperature reached 39.5 degrees C. Dehydration depressed the maximal external iliac artery blood flow (MIBF) and iliac vascular conductance (IVC) attained during EH in the euhydrated state by 37 and 43%, respectively. Rehydration with either water or saline solution, however, restored maximal MIBF and IVC to euhydrated levels. Because plasma osmolality remained at dehydrated levels after rehydration with saline, hyperosmolality does not produce the dehydration-induced attenuation in hindlimb blood flow.

  10. Experimental dehydration of natural obsidian and estimation of DH2O at low water contents

    Science.gov (United States)

    Jambon, A.; Zhang, Y.; Stolper, E. M.

    1992-01-01

    Water diffusion experiments were carried out by dehydrating rhyolitic obsidian from Valles Caldera (New Mexico, USA) at 510-980 degrees C. The starting glass wafers contained approximately 0.114 wt% total water, lower than any glasses previously investigated for water diffusion. Weight loss due to dehydration was measured as a function of experiment duration, which permits determination of mean bulk water diffusivity, mean Dw. These diffusivities are in the range of 2.6 to 18 X 10(-14) m2/s and can be fit with the following Arrhenius equation: ln mean Dw (m2/s) = -(25.10 +/- 1.29) - (46,480 +/- 11,400) (J/mol) / RT, except for two replicate runs at 510 degrees C which give mean Dw values much lower than that defined by the above equation. When interpreted according to a model of water speciation in which molecular H2O is the diffusing species with concentration-independent diffusivity while OH units do not contribute to the transport but react to provide H2O, the data (except for the 510 degrees C data) are in agreement with extrapolation from previous results and hence extend the previous data base and provide a test of the applicability of the model to very low water contents. Mean bulk water diffusivities are about two orders of magnitude less than molecular H2O diffusivities because the fraction of molecular H2O out of total water is very small at 0.114 wt% total water and less. The 510 degrees C experimental results can be interpreted as due to slow kinetics of OH to H2O interconversion at low temperatures.

  11. Experiments on room temperature optical fiber-fiber direct bonding

    Science.gov (United States)

    Hao, Jinping; Yan, Ping; Xiao, Qirong; Wang, Yaping; Gong, Mali

    2012-08-01

    High quality permanent connection between optical fibers is a significant issue in optics and communication. Studies on room temperature optical large diameter fiber-fiber direct bonding, which is essentially surface interactions of glass material, are presented here. Bonded fiber pairs are obtained for the first time through the bonding technics illustrated here. Two different kinds of bonding technics are provided-fresh surface (freshly grinded and polished) bonding and hydrophobic surface (activated by H2SO4 and HF) bonding. By means of fresh surface bonding, a bonded fiber pair with light transmitting efficiency of 98.1% and bond strength of 21.2 N is obtained. Besides, in the bonding process, chemical surface treatment of fibers' end surfaces is an important step. Therefore, various ways of surface treatment are analyzed and compared, based on atomic force microscopy force curves of differently disposed surfaces. According to the comparison, fresh surfaces are suggested as the prior choice in room temperature optical fiber-fiber bonding, owing to their larger adhesive force, attractive force, attractive distance, and adhesive range.

  12. Guidelines for glycol dehydrator design; Part 1

    Energy Technology Data Exchange (ETDEWEB)

    Manning, W.P. (Coastal Chemical Co., Inc., Houston, TX (United States)); Wood, H.S. (Maloney-Crawford, Tulsa, OK (United States))

    1993-01-01

    Better designs and instrumentation improve glycol dehydrator performance. This paper reports on these guidelines which emphasize efficient water removal from natural gas. Water, a common contaminant in natural gas, causes operational problems when it forms hydrates and deposits on solid surfaces. Result: plugged valves, meters, instruments and even pipelines. Simple rules resolve these problems and reduce downtime and maintenance costs.

  13. Pelagic sea snakes dehydrate at sea

    Science.gov (United States)

    Lillywhite, Harvey B.; Sheehy, Coleman M.; Brischoux, François; Grech, Alana

    2014-01-01

    Secondarily marine vertebrates are thought to live independently of fresh water. Here, we demonstrate a paradigm shift for the widely distributed pelagic sea snake, Hydrophis (Pelamis) platurus, which dehydrates at sea and spends a significant part of its life in a dehydrated state corresponding to seasonal drought. Snakes that are captured following prolonged periods without rainfall have lower body water content, lower body condition and increased tendencies to drink fresh water than do snakes that are captured following seasonal periods of high rainfall. These animals do not drink seawater and must rehydrate by drinking from a freshwater lens that forms on the ocean surface during heavy precipitation. The new data based on field studies indicate unequivocally that this marine vertebrate dehydrates at sea where individuals may live in a dehydrated state for possibly six to seven months at a time. This information provides new insights for understanding water requirements of sea snakes, reasons for recent declines and extinctions of sea snakes and more accurate prediction for how changing patterns of precipitation might affect these and other secondarily marine vertebrates living in tropical oceans. PMID:24648228

  14. Pelagic sea snakes dehydrate at sea.

    Science.gov (United States)

    Lillywhite, Harvey B; Sheehy, Coleman M; Brischoux, François; Grech, Alana

    2014-05-07

    Secondarily marine vertebrates are thought to live independently of fresh water. Here, we demonstrate a paradigm shift for the widely distributed pelagic sea snake, Hydrophis (Pelamis) platurus, which dehydrates at sea and spends a significant part of its life in a dehydrated state corresponding to seasonal drought. Snakes that are captured following prolonged periods without rainfall have lower body water content, lower body condition and increased tendencies to drink fresh water than do snakes that are captured following seasonal periods of high rainfall. These animals do not drink seawater and must rehydrate by drinking from a freshwater lens that forms on the ocean surface during heavy precipitation. The new data based on field studies indicate unequivocally that this marine vertebrate dehydrates at sea where individuals may live in a dehydrated state for possibly six to seven months at a time. This information provides new insights for understanding water requirements of sea snakes, reasons for recent declines and extinctions of sea snakes and more accurate prediction for how changing patterns of precipitation might affect these and other secondarily marine vertebrates living in tropical oceans.

  15. DEHYDRATION AND DEOILING OF METAL CHIP

    Directory of Open Access Journals (Sweden)

    O. M. Djakonov

    2011-01-01

    Full Text Available Influence of technology factors on efficiency of processes of dehydration and deoiling of metal chips is investigated. The new universal simple method of definition of coefficients of filtration and free infiltration of liquid in porous medium is offered.

  16. DEHYDRATION IN CHILDREN WITH ACUTE DIARRHEA

    Directory of Open Access Journals (Sweden)

    S. V. Khaliullina

    2014-01-01

    Full Text Available The article is focused on the main issues of the regulation of water-electrolyte metabolism in children, possible variants of its disorder in acute diarrhoeal diseases. The clinical features of dehydration depending on the severity and qualitative component of losses are described, recommendations on laboratory diagnosis and treatment are provided. 

  17. Desidratação osmótica de pêssegos em função da temperatura e concentração do xarope de sacarose Osmotic dehydration of peaches as a function of temperature and concentration of sucrose syrup

    Directory of Open Access Journals (Sweden)

    Sílvia P. M Germer

    2011-02-01

    Full Text Available A desidratação osmótica pela qual passa a produção de fruta, é uma alternativa para o aproveitamento dos excedentes da persicultura. Neste trabalho se avaliou a influência da temperatura e da concentração do xarope de sacarose na desidratação osmótica de pêssegos, e se investigaram variações de propriedades físicas, químicas e dos parâmetros da desidratação osmótica (perda de massa e de água; incorporação de sólidos. O delineamento central composto rotacional foi utilizado variando-se a temperatura (30 a 50 ºC e a concentração (45 a 65 °Brix da solução osmótica e se fixando a razão mássica xarope:fruta 4:1, tempo de processo 4 h, e formato dos pedaços (metades. Na análise sensorial empregou-se o método de aceitação avaliando-se os atributos aparência, sabor, textura, cor e qualidade geral. Modelaram-se os resultados com o programa Statistica (v 6.0, através da Metodologia de Superfície de Resposta. Os seguintes modelos matemáticos resultaram significativos (p The production of dried peach by osmotic dehydration is an alternative for using the excess of peach production. The influence of the temperature and concentration of the sucrose syrup in osmotic dehydration of peaches was evaluated. Variations in physical and chemical properties, and osmotic dehydration parameters (weight loss and water loss; solids incorporation were investigated. An experimental central composite design was employed ranging the temperature (30 to 50 ºC and concentration (45 to 65 °Brix, keeping the syrup:fruit mass ratio 4:1, process time 4 h, and format pieces (halves. The degree of acceptance was used in the sensory analysis, evaluating the following characteristics: appearance, taste, texture, colour and overall quality. The results were modelled using the Statistica program (v. 6.0 employing the Response Surface Methodology. The following mathematical models resulted significant (p < 0.05 and predictive: dimensionless

  18. Lunar electrical conductivity, permeability and temperature from Apollo magnetometer experiments

    Science.gov (United States)

    Dyal, P.; Parkin, C. W.; Daily, W. D.

    1977-01-01

    Magnetometers were deployed at four Apollo sites on the moon to measure remanent and induced lunar magnetic fields. Measurements from this network of instruments were used to calculate the electrical conductivity, temperature, magnetic permeability, and iron abundance of the lunar interior. The measured lunar remanent fields range from 3 gammas minimum at the Apollo 15 site to 327 gammas maximum at the Apollo 16 site. Simultaneous magnetic field and solar plasma pressure measurements show that the remanent fields at the Apollo 12 and 16 sites interact with, and are compressed by, the solar wind. Remanent fields at Apollo 12 and Apollo 16 are increased 16 gammas and 32 gammas, respectively, by a solar plasma bulk pressure increase of 1.5 X 10 to the -7th power dynes/sq cm. Global lunar fields due to eddy currents, induced in the lunar interior by magnetic transients, were analyzed to calculate an electrical conductivity profile for the moon. From nightside magnetometer data in the solar wind it was found that deeper than 170 km into the moon the conductivity rises from .0003 mhos/m to .10 mhos/m at 100 km depth. Recent analysis of data obtained in the geomagnetic tail, in regions free of complicating plasma effects, yields results consistent with nightside values.

  19. A Simple Experiment to Determine the Characteristics of an NTC Thermistor for Low-Temperature Measurement Applications

    Science.gov (United States)

    Mawire, A.

    2012-01-01

    A simple low-cost experiment for undergraduate students to determine the characteristics of a negative temperature coefficient of resistance thermistor is presented. The experiment measures the resistance-temperature and voltage-temperature characteristics of the thermistor. Results of the resistance-temperature experiment are used to determine…

  20. A Simple Experiment to Determine the Characteristics of an NTC Thermistor for Low-Temperature Measurement Applications

    Science.gov (United States)

    Mawire, A.

    2012-01-01

    A simple low-cost experiment for undergraduate students to determine the characteristics of a negative temperature coefficient of resistance thermistor is presented. The experiment measures the resistance-temperature and voltage-temperature characteristics of the thermistor. Results of the resistance-temperature experiment are used to determine…

  1. Effect of process variables on the osmotic dehydration of star-fruit slices

    Directory of Open Access Journals (Sweden)

    Camila Dalben Madeira Campos

    2012-06-01

    Full Text Available The objective of this work was to study the effect of blanching and the influence of temperature, solution concentration, and the initial fruit:solution ratio on the osmotic dehydration of star-fruit slices. For blanching, different concentrations of citric and ascorbic acids were studied. The samples immersed in 0.75% citric acid presented little variation in color in relation to the fresh star-fruit. Osmotic dehydration was carried out in an incubator with orbital shaking, controlled temperature, and constant shaking at 120 rpm. The influence of process variables was studied in trials defined by a complete 23 central composite design. In general, water loss and solids gain were positively influenced by temperature and by solution concentration. Nevertheless, lower temperatures reduced water loss throughout the osmotic dehydration process. An increase in the amount of dehydrating solution (initial fruit:solution ratio slightly influenced the evaluated responses. The process carried out at 50 ºC with a solution concentration of 50% resulted in a product with lower solids gain and greater water loss. Under these conditions, blanching minimized the effect of the osmotic treatment on star-fruit browning, and therefore the blanched fruits showed little variation in color in relation to the fresh fruit.

  2. Effect of smectite dehydration on pore water geochemistry in the shallow subduction zone: An experimental approach

    National Research Council Canada - National Science Library

    A Hupers; A J Kopf

    2012-01-01

    ...) up to 70 MPa and at constant temperatures (T) of 20°C, 60°C and 100°C. Fluids expelled during the tests were analyzed for major and trace elements to evaluate dehydration and fluid-rock interaction with increasing PT conditions...

  3. Technology Advances and Mechanistic Modelling in Freeze-drying and Dehydration of Food

    Directory of Open Access Journals (Sweden)

    Wanren Chen

    2015-08-01

    Full Text Available Aim of study is to introduce some advanced freeze-drying technology and mechanistic modelling in freeze-drying and dehydration of food, freeze-drying is based on the dehydration by sublimation of a frozen product, due to very low temperature, all the deterioration activity and microbiological activity are stopped and provide better quality to the final product. Meanwhile the main problems of the freeze-dried food were proposed and its prospect and outlook was also analyzed, expecting to obtain technical and theoretical support for the production of freeze-drying food.

  4. Solvation mechanisms of nedocromil sodium from activation energy and reaction enthalpy measurements of dehydration and dealcoholation.

    Science.gov (United States)

    Richards, Alison C; McColm, Ian J; Harness, J Barrie

    2002-04-01

    Two independent athermal methods of analysis have been used to determine the activation energies associated with the dehydration of nedocromil sodium hydrates. For the highest temperature reaction, monohydrate to the anhydrate, the differences in the measured activation energies indicate a three-dimensional nucleation mechanism in the bulk of the crystal with subsequent three-dimensional anhydrate crystal growth. The number of critical nuclei varies inversely with heating rate. Measured enthalpy values for successive removal of water molecules at 31.7 +/- 1.0, 91.3 +/- 0.8, and 193 +/- 0.6 degrees C are the same, within experimental error, at 21.6 +/- 2.6 kJ (mol H(2)O)(-1), as determined from differential thermal analysis traces. This result implies that an earlier concept of "strong" and "weak" water binding is not relevant and temperatures at which H(2)O molecules are removed is related to nucleation effects and not bond energies. The low temperature shoulder on the 91.3 degrees C peak is identified as an effect arising from open pan analysis conditions. The appearance of "transient" peaks in the conditioning stage of nedocromil sodium trihydrate thermal analysis experiments have been investigated and an explanation based on the presence of alcoholates [(NS)(4) small middle dot 5CH(3)OH, (NS)(5) small middle dot 9C(2)H(5)OH, and (NS)(2) small middle dot C(3)H(7)OH] in the preparations is proposed.

  5. Hydration or dehydration: competing effects of upper tropospheric cloud radiation on the TTL water vapor

    Directory of Open Access Journals (Sweden)

    L. Wu

    2012-02-01

    Full Text Available A tropical channel version of the Weather Research and Forecasting (WRF model is used to investigate the radiative impacts of upper tropospheric clouds on water vapor in the tropical tropopause layer (TTL. The WRF simulations of cloud radiative effects and water vapor in the upper troposphere and lower stratosphere show reasonable agreement with observations, including approximate reproduction of the water vapor "tape recorder" signal. By turning on and off the upper tropospheric cloud radiative effect (UTCRE above 200 hPa, we find that the UTCRE induces a warming of 0.76 K and a moistening of 9% in the upper troposphere at 215 hPa. However, the UTCRE cools and dehydrates the TTL, with a cooling of 0.82 K and a dehydration of 16% at 100 hPa. The enhanced vertical ascent due to the UTCRE contributes substantially to mass transport and the dehydration in the TTL. The hydration due to the enhanced vertical transport is counteracted by the dehydration from adiabatic cooling associated with the enhanced vertical motion. The UTCRE also substantially changes the horizontal winds in the TTL, resulting in shifts of the strongest dehydration away from the lowest temperature anomalies in the TTL. The UTCRE increases in-situ cloud formation in the TTL. A seasonal variation is shown in the simulated UTCRE, with stronger impact in the moist phase from June to November than in the dry phase from December to May.

  6. Simulation of mass transfer during osmotic dehydration of apple: a power law approximation method

    Science.gov (United States)

    Abbasi Souraki, B.; Tondro, H.; Ghavami, M.

    2014-10-01

    In this study, unsteady one-dimensional mass transfer during osmotic dehydration of apple was modeled using an approximate mathematical model. The mathematical model has been developed based on a power law profile approximation for moisture and solute concentrations in the spatial direction. The proposed model was validated by the experimental water loss and solute gain data, obtained from osmotic dehydration of infinite slab and cylindrical shape samples of apple in sucrose solutions (30, 40 and 50 % w/w), at different temperatures (30, 40 and 50 °C). The proposed model's predictions were also compared with the exact analytical and also a parabolic approximation model's predictions. The values of mean relative errors respect to the experimental data were estimated between 4.5 and 8.1 %, 6.5 and 10.2 %, and 15.0 and 19.1 %, for exact analytical, power law and parabolic approximation methods, respectively. Although the parabolic approximation leads to simpler relations, the power law approximation method results in higher accuracy of average concentrations over the whole domain of dehydration time. Considering both simplicity and precision of the mathematical models, the power law model for short dehydration times and the simplified exact analytical model for long dehydration times could be used for explanation of the variations of the average water loss and solute gain in the whole domain of dimensionless times.

  7. Colour, phenolic content and antioxidant capacity of some fruits dehydrated by a combination of different methods.

    Science.gov (United States)

    Chong, Chien Hwa; Law, Chung Lim; Figiel, Adam; Wojdyło, Aneta; Oziembłowski, Maciej

    2013-12-15

    The objective of this study was to improve product quality of dehydrated fruits (apple, pear, papaya, mango) using combined drying techniques. This involved investigation of bioactivity, colour, and sensory assessment on colour of the dried products as well as the retention of the bio-active ingredients. The attributes of quality were compared in regard to the quality of dehydrated samples obtained from continuous heat pump (HP) drying technique. It was found that for apple, pear and mango the total colour change (ΔE) of samples dried using continuous heat pump (HP) or heat pump vacuum-microwave (HP/VM) methods was lower than of samples dried by other combined methods. However, for papaya, the lowest colour change exhibited by samples dried using hot air-cold air (HHC) method and the highest colour change was found for heat pump (HP) dehydrated samples. Sensory evaluation revealed that dehydrated pear with higher total colour change (ΔE) is more desirable because of its golden yellow appearance. In most cases the highest phenol content was found from fruits dried by HP/VM method. Judging from the quality findings on two important areas namely colour and bioactivity, it was found that combined drying method consisted of HP pre-drying followed by VM finish drying gave the best results for most dehydrated fruits studied in this work as the fruits contain first group of polyphenol compounds, which preferably requires low temperature followed by rapid drying strategy.

  8. Sand box experiments to evaluate the influence of subsurface temperature probe design on temperature based water flux calculation

    Directory of Open Access Journals (Sweden)

    M. Munz

    2011-06-01

    Full Text Available Quantification of subsurface water fluxes based on the one dimensional solution to the heat transport equation depends on the accuracy of measured subsurface temperatures. The influence of temperature probe setup on the accuracy of vertical water flux calculation was systematically evaluated in this experimental study. Four temperature probe setups were installed into a sand box experiment to measure temporal highly resolved vertical temperature profiles under controlled water fluxes in the range of ±1.3 m d−1. Pass band filtered time series provided amplitude and phase of the diurnal temperature signal varying with depth depending on water flux. Amplitude ratios of setups directly installed into the saturated sediment significantly varied with sand box hydraulic gradients. Amplitude ratios provided an accurate basis for the analytical calculation of water flow velocities, which matched measured flow velocities. Calculated flow velocities were sensitive to thermal properties of saturated sediment and to probe distance, but insensitive to thermal dispersivity equal to solute dispersivity. Amplitude ratios of temperature probe setups indirectly installed into piezometer pipes were influenced by thermal exchange processes within the pipes and significantly varied with water flux direction only. Temperature time lags of small probe distances of all setups were found to be insensitive to vertical water flux.

  9. Dehydration and dehydrogenation of ethylene glycol on rutile TiO2(110).

    Science.gov (United States)

    Li, Zhenjun; Kay, Bruce D; Dohnálek, Zdenek

    2013-08-07

    The interactions of ethylene glycol with a partially reduced rutile TiO2(110) surface have been studied using temperature programmed desorption (TPD). The saturation coverage on surface Ti rows is determined to be 0.43 monolayer (ML), slightly less than one ethylene glycol per two Ti sites. Most of the adsorbed ethylene glycol (∼80%) undergoes further reactions to yield other products. Two major channels are observed, dehydration yielding ethylene and water and dehydrogenation yielding acetaldehyde and hydrogen. Hydrogen formation is rather surprising as it has not been observed previously on TiO2(110) from simple organic molecules. The coverage dependent yields of ethylene and acetaldehyde correlate well with those of water and hydrogen, respectively. Dehydration dominates at lower ethylene glycol coverages (ethylene glycol coverages (>0.2 ML). Our results suggest that the observed dehydration and dehydrogenation reactions proceed via different surface intermediates.

  10. Spot heating calculation for a heavy ion driven high temperature experiment

    Energy Technology Data Exchange (ETDEWEB)

    Lee, E.P.; Mark, J.W.K.

    1984-04-01

    An analytical model is used to predict the temperature reached in a spot heating experiment driven by a heavy ion beam. A discussion of physical processes and approximations is included. 10 references, 9 figures, 3 tables.

  11. Fluid replacement following dehydration reduces oxidative stress during recovery.

    Science.gov (United States)

    Paik, Il-Young; Jeong, Myung-Hyun; Jin, Hwa-Eun; Kim, Young-Il; Suh, Ah-Ram; Cho, Su-Youn; Roh, Hee-Tae; Jin, Chan-Ho; Suh, Sang-Hoon

    2009-05-22

    To investigate the effects of hydration status on oxidative DNA damage and exercise performance, 10 subjects ran on a treadmill until exhaustion at 80% VO(2max) during four different trials [control (C), 3% dehydration (D), 3% dehydration+water (W) or 3% dehydration+sports drink (S)]. Dehydration significantly decreased exercise time to exhaustion (DDehydration significantly increased oxidative DNA damage during exercise, but fluid replacement with water or sports drink alleviated it equally. These results suggest that (1) dehydration impairs exercise performance and increases DNA damage during exercise to exhaustion; and (2) fluid replacement prolongs exercise endurance and attenuates DNA damage.

  12. Rationalization of Sucrose Solution Using During the Fruit Osmotic Dehydration

    Directory of Open Access Journals (Sweden)

    Mirko Babić

    2009-12-01

    Full Text Available The model of sustainable energy production of dried fruit conducted by using combined technology – the model that has been developed at the Faculty of Agriculture in Novi Sad – includes osmotic dehydration of fruit in sucrose solution. During the process of dehydration the moisture content of the solution is increased due to mass transfer of moisture from fruit. This article examines different models of recycling and concentrating of the solution. Thus, the model for concentrating of the solution has been chosen according to this analysis, and it has been applied within its own technology. Evaporators of the low temperature solution have been used and they are based on the solar energy source. Two types of devices have been made on the basis of the heating process of evaporating. One type is filled with the stainless steel shavings, while the other type is based on the fillings by plates. The paper presents the evaluation model of the benefits of this concentrating manner as well as the evaluation criterion of the evaporators’ fillings types. The energy support used here was an original solar air heater of semi-concentrated type.

  13. Temperature dependence of the cosphi conductance in Josephson tunnel junctions determined from plasma resonance experiments

    DEFF Research Database (Denmark)

    Pedersen, Niels Falsig; Sørensen, O. H.; Mygind, Jesper

    1978-01-01

    The microwave response at 9 GHz of Sn-O-Sn tunnel-junction current biased at zero dc voltage has been measured just below the critical temperature Tc of the Sn films. The temperature dependence of the cosφ conductance is determined from the resonant response at the junction plasma frequency fp...... of the experiment....

  14. "Dehydrated" chondrules from the Murchison (CM) chondrite

    OpenAIRE

    Inoue, Mutsuo; Nakamura,Noboru

    1996-01-01

    Two "dehydrated" chondrules (MC-5 and MC-27) were obtained from close to the fusion crust of the Murchison (CM) meteorite. They have a porphyritic texture with angular or rounded (relict) olivines containing abundant voids, recrystallized olivines, and numerous interstitial Fe oxide grains embedded in groundmass glass. This peculiar texture is similar to that of the fusion crust from the Orgueil (CI) chondrite, indicating that the texture formed during the reheating at the atmospheric entry o...

  15. Could Neonatal Hypernatremia Dehydration Influence Hearing Status?

    Directory of Open Access Journals (Sweden)

    Hassan Boskabadi

    2014-01-01

    Full Text Available Introduction: Neonatal hypernatremia dehydration (NHD is a dangerous condition in neonates, which is accompanied by acute complications (renal failure, cerebral edema, and cerebral hemorrhage and chronic complications (developmental delay. Children begin learning language from birth, and hearing impairment interferes with this process. We assessed the hearing status of infants with hypernatremia dehydration.   Materials and Methods: In a case-control study in 110 infants presenting at the Ghaem Hospital (Mashhad, Iran between 2007 and 2011, we examined the incidence of hearing impairment in infants suffering from hypernatremia dehydration (serum sodium >150 mEq/L in comparison with infants with normal sodium level (serum sodium ≤150 mEq/L.   Results: Three of 110 cases examined in the study group showed a transient hearing impairment. A mean serum sodium level of 173mg/dl was reported among hearing-impaired infants.   Conclusion:  Transient hearing impairment was higher in infants with hypernatremia; although this difference was not significant (P>0.05. Hearing impairment was observed in cases of severe hypernatremia.  

  16. Dehydration and endurance performance in competitive athletes.

    Science.gov (United States)

    Goulet, Eric D B

    2012-11-01

    The field of research examining the link between dehydration and endurance performance is at the dawn of a new era. This article reviews the latest findings describing the relationship between exercise-induced dehydration and endurance performance and provides the knowledge necessary for competitive, endurance-trained athletes to develop a winning hydration strategy. Acute, pre-exercise body weight loss at or above 3% may decrease subsequent endurance performance. Therefore, endurance athletes should strive to start exercise well hydrated, which can be achieved by keeping thirst sensation low and urine color pale and drinking approximately 5-10 mL/kg body weight of water 2 h before exercise. During exercise lasting 1 h or less, dehydration does not decrease endurance performance, but athletes are encouraged to mouth-rinse with sports drinks. During exercise lasting longer than 1 h, in which fluid is readily available, drinking according to the dictates of thirst maximizes endurance performance. In athletes whose thirst sensation is untrustworthy or when external factors such as psychological stress or repeated food intake may blunt thirst sensation, it is recommended to program fluid intake to maintain exercise-induced body weight loss around 2% to 3%.

  17. Influence of Dehydration on Intermittent Sprint Performance.

    Science.gov (United States)

    Davis, Jon-Kyle; Laurent, C Matt; Allen, Kimberly E; Green, J Matt; Stolworthy, Nicola I; Welch, Taylor R; Nevett, Michael E

    2015-09-01

    This study examined the effects of dehydration on intermittent sprint performance and perceptual responses. Eight male collegiate baseball players completed intermittent sprints either dehydrated (DEHY) by 3% body mass or euhydrated (EU). Body mass was reduced through exercise in the heat with controlled fluid restriction occurring 1 day before the trial. Participants completed twenty-four 30-m sprints divided into 3 bouts of 8 sprints with 45 seconds of rest between each sprint and 3 minutes between each bout. Perceived recovery status (PRS) scale was recorded before the start of each trial. Heart rate (HR), ratings of perceived exertion (RPE) (0-10 OMNI scale), and perceived readiness (PR) scale were recorded after every sprint, and session RPE (SRPE) was recorded 20 minutes after completing the entire session. A 2 (condition) × 3 (bout of sprints) repeated-measures ANOVA revealed a significant main effect of condition on mean sprint time (p = 0.03), HR (p Dehydration impaired sprint performance, negatively altered perception of recovery status before exercise, and increased RPE and HR response.

  18. Degradation and contamination of perfluorinated sulfonic acid membrane due to swelling-dehydration cycles

    DEFF Research Database (Denmark)

    Andersen, Shuang Ma; Morgen, Per; Skou, Eivind Morten

    to the membrane degradation in direct methanol fuel cells (DMFCs), where liquid water has direct contact with the electrolyte. An ex-situ experiment was established with swelling-dehydration cycles on the membrane. However, formation of sulfonic anhydride was not detected during the entire treatment; instead...... contamination from calcium was found the primary reason for the deterioration of the membrane properties....

  19. On temperature variations during 3He Polarization experiments in Pomeranchuk cells

    DEFF Research Database (Denmark)

    Geng, Q.; Rasmussen, Finn Berg

    1984-01-01

    Simple model calculations have been performed in relation to temperature changes in decompression experiments with Pomeranchuk cells, aiming at the production of spin polarized liquid **3He. Comparison with reported experiments indicates that thermal contact with the surroundings is too strong...

  20. Ion temperature anisotropy in high power helium neutral beam fuelling experiments in JET

    Energy Technology Data Exchange (ETDEWEB)

    Maas, A.C.; Core, W.G.F.; Gerstel, U.C.; Von Hellermann, M.G.; Koenig, R.W.T.; Marcus, F.B. [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking

    1994-07-01

    During helium beam fuelling experiments in JET, distinctive anisotropic features have been observed in the velocity distribution function describing both fast and thermal alpha particle populations. During the initial fuelling phase the central helium ion temperature observed perpendicular to the magnetic field is higher than the central electron temperature, while the central helium ion temperature observed parallel to the magnetic field is lower than or equal to the central electron temperature. In order to verify temperature measurements of both perpendicular and parallel lines of sight, other independent methods of deducing the ion temperature are investigated: deuterium ion temperature, deuterium density, comparison with neutron rates and profiles (influence of a possible metastable population of helium). 6 refs., 7 figs.

  1. Impact of geographic variations of the convective and dehydration center on stratospheric water vapor over the Asian monsoon region

    Science.gov (United States)

    Zhang, Kai; Fu, Rong; Wang, Tao; Liu, Yimin

    2016-06-01

    The Asian monsoon region is the most prominent moisture center of water vapor in the lower stratosphere (LS) during boreal summer. Previous studies have suggested that the transport of water vapor to the Asian monsoon LS is controlled by dehydration temperatures and convection mainly over the Bay of Bengal and Southeast Asia. However, there is a clear geographic variation of convection associated with the seasonal and intra-seasonal variations of the Asian monsoon circulation, and the relative influence of such a geographic variation of convection vs. the variation of local dehydration temperatures on water vapor transport is still not clear. Using satellite observations from the Aura Microwave Limb Sounder (MLS) and a domain-filling forward trajectory model, we show that almost half of the seasonal water vapor increase in the Asian monsoon LS are attributable to geographic variations of convection and resultant variations of the dehydration center, of which the influence is comparable to the influence of the local dehydration temperature increase. In particular, dehydration temperatures are coldest over the southeast and warmest over the northwest Asian monsoon region. Although the convective center is located over Southeast Asia, an anomalous increase of convection over the northwest Asia monsoon region increases local diabatic heating in the tropopause layer and air masses entering the LS are dehydrated at relatively warmer temperatures. Due to warmer dehydration temperatures, anomalously moist air enters the LS and moves eastward along the northern flank of the monsoon anticyclonic flow, leading to wet anomalies in the LS over the Asian monsoon region. Likewise, when convection increases over the Southeast Asia monsoon region, dry anomalies appear in the LS. On a seasonal scale, this feature is associated with the monsoon circulation, convection and diabatic heating marching towards the northwest Asia monsoon region from June to August. The march of convection

  2. Progress report on the design of a varying temperature irradiation experiment for operation in HFIR

    Energy Technology Data Exchange (ETDEWEB)

    Qualls, A.L. [Oak Ridge National Lab., TN (United States); Muroga, T.

    1997-04-01

    The purpose of this experiment is to determine effects of temperature variation during irradiation on microstructure and mechanical properties of potential fusion reactor structural materials. A varying temperature irradiation experiment is being performed under the framework of the Japan-USA Program of Irradiation Tests for fusion Research (JUPITER) to study the effects of temperature variation on the microstructure and mechanical properties of candidate fusion reactor structural materials. An irradiation capsule has been designed for operation in the High Flux Isotope Reactor at Oak Ridge National Laboratory that will allow four sets of metallurgical test specimens to be irradiated to exposure levels ranging from 5 to 10 dpa. Two sets of specimens will be irradiated at constant temperature of 500{degrees}C and 350{degrees}C. Matching specimen sets will be irradiated to similar exposure levels, with 10% of the exposure to occur at reduced temperatures of 300{degrees}C and 200{degrees}C.

  3. Influence of coolant temperature and pressure on destructive forces at fuel failure in the NSRR experiment

    Energy Technology Data Exchange (ETDEWEB)

    Kusagaya, Kazuyuki [Global Nuclear Fuel - Japan Co., Ltd., Yokosuka, Kanagawa (Japan); Sugiyama, Tomoyuki; Nakamura, Takehiko; Uetsuka, Hiroshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2003-01-01

    In order to design a new experimental capsule to be used in the NSRR (Nuclear Safety Research Reactor) experiment with the temperature and pressure conditions in a typical commercial BWR, coolant temperature and pressure influence is estimated for destructive forces during fuel rod failure in the experiment simulating reactivity-initiated accident (RIA). Considering steam property dependence on temperature and pressure, it is qualitatively shown that the destructive forces in the BWR operation condition are smaller than those in the room temperature and atmospheric pressure condition. Water column velocity, which determines impact by water hammer, is further investigated quantitatively by modeling the experimental system and water hammer phenomenon. As a result, the maximum velocity of the water column in the BWR operation conditions is calculated to be only about 10% of that in the room temperature and atmospheric pressure condition. (author)

  4. Mass transfer during osmotic dehydration of celery stalks in a batch osmo-reactor

    Science.gov (United States)

    Sareban, M.; Abbasi Souraki, B.

    2017-03-01

    In this study, dehydration behavior of bulk of celery stalks, during osmotic drying in a limited volume of salt solution, was investigated. Experiments were carried out in the three initial solution concentrations of 10, 18 and 25 % (w/w) and at the three temperatures of 35, 45 and 55 °C. The volume ratio of the fruit to the solution was considered 1:3. A two-parameter model was used for prediction of kinetics of mass transfer and values of equilibrium moisture loss and solid gain. Moisture and salt effective diffusivities in celery stalks were estimated by fitting the experimental data of moisture loss and solute gain to the analytical solution of Fick's second law of diffusion. The analytical model was solved by defining a partition factor, K, assuming that the concentration of solute just within the surface of the material is K times that in the solution. Results showed that moisture and salt effective diffusivities and equilibrium values of moisture loss and solute gain increased with increasing the temperature and solution concentration. Results showed a good agreement between the two parameter model (with mean relative error of 4.016 % for moisture loss and 5.977 % for solid gain), analytical solution of Fick's second law (with mean relative error of 8.924 % for moisture loss and 9.164 % for solid gain) and experimental data.

  5. Mass transfer during osmotic dehydration of celery stalks in a batch osmo-reactor

    Science.gov (United States)

    Sareban, M.; Abbasi Souraki, B.

    2016-07-01

    In this study, dehydration behavior of bulk of celery stalks, during osmotic drying in a limited volume of salt solution, was investigated. Experiments were carried out in the three initial solution concentrations of 10, 18 and 25 % (w/w) and at the three temperatures of 35, 45 and 55 °C. The volume ratio of the fruit to the solution was considered 1:3. A two-parameter model was used for prediction of kinetics of mass transfer and values of equilibrium moisture loss and solid gain. Moisture and salt effective diffusivities in celery stalks were estimated by fitting the experimental data of moisture loss and solute gain to the analytical solution of Fick's second law of diffusion. The analytical model was solved by defining a partition factor, K, assuming that the concentration of solute just within the surface of the material is K times that in the solution. Results showed that moisture and salt effective diffusivities and equilibrium values of moisture loss and solute gain increased with increasing the temperature and solution concentration. Results showed a good agreement between the two parameter model (with mean relative error of 4.016 % for moisture loss and 5.977 % for solid gain), analytical solution of Fick's second law (with mean relative error of 8.924 % for moisture loss and 9.164 % for solid gain) and experimental data.

  6. Effect of hydrothermal circulation on slab dehydration for the subduction zone of Costa Rica and Nicaragua

    Science.gov (United States)

    Rosas, Juan Carlos; Currie, Claire A.; Harris, Robert N.; He, Jiangheng

    2016-06-01

    Dehydration of subducting oceanic plates is associated with mantle wedge melting, arc volcanism, intraslab earthquakes through dehydration embrittlement, and the flux of water into the mantle. In this study, we present two-dimensional thermal models of the Costa Rica-Nicaragua subduction zone to investigate dehydration reactions within the subducting Cocos plate. Seismic and geochemical observations indicate that the mantle wedge below Nicaragua is more hydrated than that below Costa Rica. These trends have been hypothesized to be due to a variation in either the thermal state or the hydration state of the subducting slab. Despite only small variations in plate age along strike, heat flow measurements near the deformation front reveal significantly lower heat flow offshore Nicaragua than offshore Costa Rica. These measurements are interpreted to reflect an along-strike change in the efficiency of hydrothermal circulation in the oceanic crust. We parameterize thermal models in terms of efficient and inefficient hydrothermal circulation and explore their impact on slab temperature in the context of dehydration models. Relative to models without fluid flow, efficient hydrothermal circulation reduces slab temperature by as much at 60 °C to depths of ∼75 km and increases the predicted depth of eclogitization by ∼15 km. Inefficient hydrothermal circulation has a commensurately smaller influence on slab temperatures and the depth of eclogitization. For both regions, the change in eclogitization depth better fits the observed intraslab crustal seismicity, but there is not a strong contrast in the slab thermal structure or location of the main dehydration reactions. Consistent with other studies, these results suggest that observed along-strike differences in mantle wedge hydration may be better explained by a northwestward increase in the hydration state of the Cocos plate before it is subducted.

  7. Osmo-convective dehydration kinetics of jackfruit (Artocarpus heterophyllus

    Directory of Open Access Journals (Sweden)

    Pragati Kaushal

    2016-06-01

    Full Text Available Osmotic dehydration is a process in which partial water is removed by immersion of water containing cellular solid in a concentrated aqueous solution of high osmotic media for a specific time and temperature. Preliminary trials were planned for finalizing the concentration of osmolyte (salt solution: 5%, 10%, 15% and 20%. The osmotically pre-treated samples were dried at 50 °C which were examined using sensory parameters. On the basis of sensory parameters, 15% salt solution concentration was considered best. The osmotically pre-treated jackfruit samples of 15% salt solution were convectively dehydrated in a tray dryer at air temperatures of 50, 60 and 70 °C at constant velocity of 1.5 m/s air flow in perforated trays. Results indicated that drying took place in falling rate period. The sample dried at 60 °C was found better in color as compared to samples at 50 and 70 °C. Mathematical models were fitted to the experimental data and the performance of these models was evaluated by comparing the coefficient of determination (R2, Root mean square error (RMSE, reduced chi-square (χ2, percent mean relative deviation modulus (E% between observed and predicted moisture ratio. The best model was chosen as one with the highest coefficient of correlation (R2; and the least χ2, RMSE and mean relative deviation modulus (E. Wang and Singh model, having χ2 and RMSE value (at 60 °C of 0.00027 and 0.01655 respectively gave the best results for describing the drying behavior of jackfruit samples.

  8. Process Design of Continuous-Flow Pervaporation Separa tion for Alcohol Dehydration

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The separation characteristics of the PVA-CS (polyvinyl alcohol-chitosan) blended composite membrane for dehydration of ethanol-water mixture are examined. The relationships of flux and separation factor with the feed concentration and operation temperature are established. Using this correlated equation, the continuous-flow pervaporation process about 500 kilolitres/year dehydrated ethanol is designed. The numbers of stage and reheater are calculated by stage-by-stage method for two kinds of cascades: one with equal membrane area and the other with 10℃C of temperature decrement per section. The results show that when the numbers of stage and reheater are the same, the cascade with 10℃C of temperature decrement has more advantages than that with equal membrane area. The influences of feed concentration and flow rate on the numbers of stage and reheater in the cascades are discnssed.

  9. Importance of temperature control for HEFLEX, a biological experiment for Spacelab 1. [plant gravitational physiology study

    Science.gov (United States)

    Chapman, D. K.; Brown, A. H.

    1979-01-01

    The importance of temperature control to HEFLEX, a Spacelab experiment designed to measure kinetic properties of Helianthis nutation in a low-g environment, is discussed. It is argued that the development of the HEFLEX experiment has been severely hampered by the inadequate control of ambient air temperature provided by the spacecraft module design. A worst case calculation shows that delivery of only 69% of the maximum yield of useful data from the HEFLEX system is guaranteed; significant data losses from inadequate temperature control are expected. The magnitude of the expected data losses indicates that the cost reductions associated with imprecise temperature controls may prove to be a false economy in the long term.

  10. Low temperature properties of the gadolinium gallium garnet: Monte Carlo versus experiments

    Science.gov (United States)

    Gingras, Michel; Yavors'kii, Taras

    2004-03-01

    Due to an arrangement of magnetic ions on triangular lattices and a negligible single-ion anisotropy, the gadolinium gallium garnet Gd_3Ga_5O_12 (GGG) is an example of a magnet with a very high geometrical frustration. The frustration is believed to be responsible for its unique magnetic properties at low temperatures by amplifying the competition between different microscopic mechanisms. These properties include extended short-range order in GGG, unusual features in its magnetic and thermal characteristics, as well as spin dynamics down to the lowest temperature. We use classical Monte Carlo simulations to investigate the low temperature properties of the system and make comparison with experiments. In particular, we study the nature of the spin-spin correlations developing at low temperatures and compare our results with the data from elastic neutron scattering experiments on isotopically enriched GGG samples.

  11. Inelastic X-ray scattering experiments at extreme conditions: high temperatures and high pressures

    Directory of Open Access Journals (Sweden)

    S.Hosokawa

    2008-03-01

    Full Text Available In this article, we review the present status of experimental techniques under extreme conditions of high temperature and high pressure used for inelastic X-ray scattering (IXS experiments of liquid metals, semiconductors, molten salts, molecular liquids, and supercritical water and methanol. For high temperature experiments, some types of single-crystal sapphire cells were designed depending on the temperature of interest and the sample thickness for the X-ray transmission. Single-crystal diamond X-ray windows attached to the externally heated high-pressure vessel were used for the IXS experiment of supercritical water and methanol. Some typical experimental results are also given, and the perspective of IXS technique under extreme conditions is discussed.

  12. Dehydration accelerates reductions in cerebral blood flow during prolonged exercise in the heat without compromising brain metabolism.

    Science.gov (United States)

    Trangmar, Steven J; Chiesa, Scott T; Llodio, Iñaki; Garcia, Benjamin; Kalsi, Kameljit K; Secher, Niels H; González-Alonso, José

    2015-11-01

    Dehydration hastens the decline in cerebral blood flow (CBF) during incremental exercise, whereas the cerebral metabolic rate for O2 (CMRO2 ) is preserved. It remains unknown whether CMRO2 is also maintained during prolonged exercise in the heat and whether an eventual decline in CBF is coupled to fatigue. Two studies were undertaken. In study 1, 10 male cyclists cycled in the heat for ∼2 h with (control) and without fluid replacement (dehydration) while internal and external carotid artery blood flow and core and blood temperature were obtained. Arterial and internal jugular venous blood samples were assessed with dehydration to evaluate CMRO2 . In study 2, in 8 male subjects, middle cerebral artery blood velocity was measured during prolonged exercise to exhaustion in both dehydrated and euhydrated states. After a rise at the onset of exercise, internal carotid artery flow declined to baseline with progressive dehydration (P exercise. During exhaustive exercise, however, euhydration delayed but did not prevent the decline in cerebral perfusion. In conclusion, during prolonged exercise in the heat, dehydration accelerates the decline in CBF without affecting CMRO2 and also restricts extracranial perfusion. Thus, fatigue is related to a reduction in CBF and extracranial perfusion rather than CMRO2 .

  13. Surviving the cold: molecular analyses of insect cryoprotective dehydration in the Arctic springtail Megaphorura arctica (Tullberg

    Directory of Open Access Journals (Sweden)

    Popović Željko D

    2009-07-01

    Full Text Available Abstract Background Insects provide tractable models for enhancing our understanding of the physiological and cellular processes that enable survival at extreme low temperatures. They possess three main strategies to survive the cold: freeze tolerance, freeze avoidance or cryoprotective dehydration, of which the latter method is exploited by our model species, the Arctic springtail Megaphorura arctica, formerly Onychiurus arcticus (Tullberg 1876. The physiological mechanisms underlying cryoprotective dehydration have been well characterised in M. arctica and to date this process has been described in only a few other species: the Antarctic nematode Panagrolaimus davidi, an enchytraied worm, the larvae of the Antarctic midge Belgica antarctica and the cocoons of the earthworm Dendrobaena octaedra. There are no in-depth molecular studies on the underlying cold survival mechanisms in any species. Results A cDNA microarray was generated using 6,912 M. arctica clones printed in duplicate. Analysis of clones up-regulated during dehydration procedures (using both cold- and salt-induced dehydration has identified a number of significant cellular processes, namely the production and mobilisation of trehalose, protection of cellular systems via small heat shock proteins and tissue/cellular remodelling during the dehydration process. Energy production, initiation of protein translation and cell division, plus potential tissue repair processes dominate genes identified during recovery. Heat map analysis identified a duplication of the trehalose-6-phosphate synthase (TPS gene in M. arctica and also 53 clones co-regulated with TPS, including a number of membrane associated and cell signalling proteins. Q-PCR on selected candidate genes has also contributed to our understanding with glutathione-S-transferase identified as the major antioxdidant enzyme protecting the cells during these stressful procedures, and a number of protein kinase signalling molecules

  14. Computational Dehydration of Crystalline Hydrates Using Molecular Dynamics Simulations

    DEFF Research Database (Denmark)

    Larsen, Anders Støttrup; Rantanen, Jukka; Johansson, Kristoffer E

    2016-01-01

    . The structural changes could be followed in real time, and in addition, an intermediate amorphous phase was identified. The computationally identified dehydrated structure (anhydrate) was slightly different from the experimentally known anhydrate structure suggesting that the simulated computational structure...... to the dehydration of ampicillin trihydrate. The crystallographic unit cell of the trihydrate is used to construct the simulation cell containing 216 ampicillin and 648 water molecules. This system is dehydrated by removing water molecules during a 2200 ps simulation, and depending on the computational dehydration...... rate, different dehydrated structures were observed. Removing all water molecules immediately and removing water relatively fast (10 water molecules/10 ps) resulted in an amorphous system, whereas relatively slow computational dehydration (3 water molecules/10 ps) resulted in a crystalline anhydrate...

  15. Coupled effects of dehydration reaction, dilatant strengthening and shear heating on dynamic fault slip

    Science.gov (United States)

    Yamashita, T.

    2012-12-01

    It is believed that dynamic fault slip is affected by thermal pressurization. However, dilatant strengthening and dehydration reaction may significantly affect the degree of thermal pressurization. In addition, it is not clear how such effects influence the fault slip as a whole. We theoretically study how dilatant strengthening, frictional heating and dehydration reaction are coupled and how they affect dynamic slip assuming a fault in a thermoporoelastic medium saturated with fluid. After mathematical analysis is carried out for 1D model, the behavior of 2D fault model is studied numerically. The porosity is assumed to increase with increasing fault slip following Suzuki and Yamashita (2008). Our mathematical formulation of dehydration reaction is based on Brantut et al.(2010); the dehydration reaction is assumed to be endothermic. In addition, starting from the temperature Ts, all the frictional energy is assumed to be absorbed by the dehydration reaction rather than converted into heat. Although Brantut et al.(2010) assumed a constant slip velocity, we consider the temporal evolution of slip assuming the Coulomb law of friction on the fault. We first make the analysis assuming adiabatic and undrained conditions for the 1D model. We find that three nondimensional parameters Su, P0 and G0 determine the system behavior if the initial temperature T0 and dehydration starting temperature Ts are given, where Su (>0) is a parameter proportional to the pore creation rate, P0 (>0) is the initial nondimensional frictional stress and G0 (>0) is a parameter proportional to the mass fraction of fluid released per unit of total rock mass divided by the energy change per unit volume of the slip zone. The nondimensional frictional stress P is defined by the Coulomb frictional stress divided by the initial shear stress, which suggests the relation 0Ts, where Te is the temperature. We find for Te>Ts that the evolution of P is described by the equation dP/dT=(1-P)(Su-G0*P), where

  16. MMC-based low-temperature detector system of the AMoRE-Pilot experiment

    Science.gov (United States)

    Kang, C. S.; Jeon, J. A.; Jo, H. S.; Kim, G. B.; Kim, H. L.; Kim, I.; Kim, S. R.; Kim, Y. H.; Kwon, D. H.; Lee, C.; Lee, H. J.; Lee, M. K.; Lee, S. H.; Oh, S. Y.; So, J. H.; Yoon, Y. S.

    2017-08-01

    Metallic magnetic calorimeters (MMCs) are highly sensitive temperature sensors that operate at millikelvin temperatures. An energy deposit in a detector can be measured using an MMC through the induced temperature increase. The MMC signal, i.e., a variation in magnetization can then be measured using a superconducting quantum interference device. MMCs are used in particle physics experiments searching for rare processes as their high sensitivity and fast response provide high energy and timing resolutions and good particle discrimination. Low-temperature detectors consisting of molybdenum-based scintillating crystals read out via MMCs were designed and built to perform simultaneous measurements of heat and light signals at millikelvin temperatures. These detectors have been used in the advanced Mo-based rare process experiment (AMoRE) that searches for the neutrinoless double beta decay of 100Mo. This article provides a detailed description of the MMC-based low-temperature detector system of the AMoRE-Pilot experiment which currently uses five crystals.

  17. Data scaling and temperature calibration in time-resolved photocrystallographic experiments

    DEFF Research Database (Denmark)

    Schmøkel, Mette Stokkebro; Kaminski, Radoslaw; Benedict, Jason B.;

    2010-01-01

    -steady-state experiments conducted at conventional sources, but not negligible in synchrotron studies in which very short laser exposures may be adequate. The relative scaling of the light-ON and light-OFF data and the correction for temperature differences between the two sets are discussed.......Experiments in which structural changes in crystals are induced by pulsed-laser exposure involve an increase in sample temperature due to the dissipation of the deposited excess energy. The heat increase is especially pronounced when a large number of pulses is needed, as in pseudo...

  18. Plasma etching of cavities into diamond anvils for experiments at high pressures and high temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Weir, S.T.; Cynn, H.; Falabella, S.; Evans, W.J.; Aracne-Ruddle, C.; Farber, D.; Vohra, Y.K. (LLNL); (UAB)

    2012-10-23

    We describe a method for precisely etching small cavities into the culets of diamond anvils for the purpose of providing thermal insulation for samples in experiments at high pressures and high temperatures. The cavities were fabricated using highly directional oxygen plasma to reactively etch into the diamond surface. The lateral extent of the etch was precisely controlled to micron accuracy by etching the diamond through a lithographically fabricated tungsten mask. The performance of the etched cavities in high-temperature experiments in which the samples were either laser heated or electrically heated is discussed.

  19. Experiment research on mechanical behavior of the aluminum laminate in the low-high temperature

    Institute of Scientific and Technical Information of China (English)

    LIN Guo-chang; XIE Zhi-min; WAN Zhi-min; DU Xing-wen

    2007-01-01

    Aluminum laminate is one kind of the rigidizable composite materials and plays an important role in construction of the inflatable space structure ( ISS), which has potential application in space in the future. But the study of the predecessors mainly focuses on the research of the mechanical behavior in the room temperature,for this reason, mechanical properties of the aluminum laminate in low-high temperature have been studied in this paper. The failure mechanism of the aluminum laminate is also analyzed in the microscopic view by JCXA - T33electron probe. The results show that the temperature has significant influence on the strength and Young's modulus of the aluminum laminate. With the increase of temperature, both the strength and Young's modulus of the aluminum laminate decrease. A model between Young's modulus of the aluminum laminate and temperatures is obtained by using Arrhenius equation. The predicted values by the model agree well with the experiment values.

  20. Dehydration and Symptoms of Delayed-Onset Muscle Soreness in Normothermic Men

    Science.gov (United States)

    Cleary, Michelle A; Sitler, Michael R; Kendrick, Zebulon V

    2006-01-01

    muscle. The signs and symptoms of DOMS after an eccentric exercise perturbation were not exacerbated by moderate dehydration of 2.7% body mass after rest and return to the normothermic condition. Conclusions: Significantly dehydrated participants who rested and returned to a normothermic condition did not experience increased characteristics of DOMS. PMID:16619093

  1. Modeling of the jack rabbit series of experiments with a temperature based reactive burn model

    Science.gov (United States)

    Desbiens, Nicolas

    2017-01-01

    The Jack Rabbit experiments, performed by Lawrence Livermore National Laboratory, focus on detonation wave corner turning and shock desensitization. Indeed, while important for safety or charge design, the behaviour of explosives in these regimes is poorly understood. In this paper, our temperature based reactive burn model is calibrated for LX-17 and compared to the Jack Rabbit data. It is shown that our model can reproduce the corner turning and shock desensitization behaviour of four out of the five experiments.

  2. Use of clinoptilolite in ethanol dehydration

    Energy Technology Data Exchange (ETDEWEB)

    Tihmillioglu, F. [Ege Univ., Izmir (Turkey); Ulku, S. [Izmir Institute of Technology (Turkey)

    1996-12-01

    Clinoptilolite-type natural zeolite, which exists in various regions of Turkey, has been experimentally studied. For the ethanol-water-local clinoptilolite system, uptake and breakthrough curves were determined under a nitrogen gas atmosphere. In adsorption kinetics and adsorption equilibrium studies, the effects of particle size, temperature and, amount of zeolite on the uptake rate have been investigated. The breakthrough curves for four different flow rates of ethanol and three different bed heights were determined in dynamic column studies. The results of the experiments show that intraparticle diffusion is the main resistance. The local clinoptilolite is a promising adsorbent for water adsorption from aqueous ethanol.

  3. Dehydration and rehydration in competative sport.

    Science.gov (United States)

    Maughan, R J; Shirreffs, S M

    2010-10-01

    Dehydration, if sufficiently severe, impairs both physical and mental performance, and performance decrements are greater in hot environments and in long-lasting exercise. Athletes should begin exercise well hydrated and should drink during exercise to limit water and salt deficits. Many athletes are dehydrated to some degree when they begin exercise. During exercise, most drink less than their sweat losses, some drink too much and a few develop hyponatraemia. Athletes should learn to assess their hydration needs and develop a personalized hydration strategy that takes account of exercise, environment and individual needs. Pre-exercise hydration status can be assessed from urine frequency and volume, with additional information from urine color, specific gravity or osmolality. Changes in hydration status during exercise can be estimated from the change in body mass: sweat rate can be estimated if fluid intake and urinary losses are also measured. Sweat salt losses can be determined by collection and analysis of sweat samples. An appropriate, individualized drinking strategy will take account of pre-exercise hydration status and of fluid, electrolyte and substrate needs before, during and after a period of exercise.

  4. Preparation and characteristic research of anhydrous magnesium chloride with dehydrated ammonium carnallite

    Institute of Scientific and Technical Information of China (English)

    ZHOU Ning-bo; CHEN Bai-zhen; HE Xin-kuai; LI Yi-bing

    2006-01-01

    Taking the saline lake bischofite and NH4Cl that was removed with the ammonia method and continuwas synthesized. And then the ammonium carnallite was dehydrated to some extent at 160℃ for 4 h. Ammonium carnallite reacted with ammonia at 240℃ for 150 min and the ammonation ammonium carnallite was produced. Finally, the ammonation ammonium carnallite was calcined at 750℃ into anhydrous magnesium chloride containing only 0.1% (mass fraction) of MgO. On the other hand, dehydrated ammonium carnallite was mixed with the solid ammonium chloride at mass ratio 1:4 at high temperature and with the differential pressure of HN3 above 30.5 kPa. The dehydrated ammonium carnallite of mixture was dehydrated at 410℃, and then calcined at 700℃ into anhydrous magnesium chloride with only 0. 087% (mass fraction) of MgO. X-ray diffraction and electron microscopy analysis results prove that anhydrous magnesium chloride obtained by both methods hasn't mixed phases, the particle is large and even has good dispersion, which is suitable for preparation of metal magnesium in the electrolysis.

  5. High temperature shock tube experiments and kinetic modeling study of diisopropyl ketone ignition and pyrolysis

    KAUST Repository

    Barari, Ghazal

    2017-03-10

    Diisopropyl ketone (DIPK) is a promising biofuel candidate, which is produced using endophytic fungal conversion. In this work, a high temperature detailed combustion kinetic model for DIPK was developed using the reaction class approach. DIPK ignition and pyrolysis experiments were performed using the UCF shock tube. The shock tube oxidation experiments were conducted between 1093K and 1630K for different reactant compositions, equivalence ratios (φ=0.5–2.0), and pressures (1–6atm). In addition, methane concentration time-histories were measured during 2% DIPK pyrolysis in argon using cw laser absorption near 3400nm at temperatures between 1300 and 1400K near 1atm. To the best of our knowledge, current ignition delay times (above 1050K) and methane time histories are the first such experiments performed in DIPK at high temperatures. Present data were used as validation targets for the new kinetic model and simulation results showed fair agreement compared to the experiments. The reaction rates corresponding to the main consumption pathways of DIPK were found to have high sensitivity in controlling the reactivity, so these were adjusted to attain better agreement between the simulation and experimental data. A correlation was developed based on the experimental data to predict the ignition delay times using the temperature, pressure, fuel concentration and oxygen concentration.

  6. Does Ice Dissolve or Does Halite Melt? A Low-Temperature Liquidus Experiment for Petrology Classes.

    Science.gov (United States)

    Brady, John B.

    1992-01-01

    Measurement of the compositions and temperatures of H2O-NaCl brines in equilibrium with ice can be used as an easy in-class experimental determination of a liquidus. This experiment emphasizes the symmetry of the behavior of brines with regard to the minerals ice and halite and helps to free students from the conceptual tethers of one-component…

  7. Simulation and Experiment of Extinction or Adaptation of Biological Species after Temperature Changes

    Science.gov (United States)

    Stauffer, D.; Arndt, H.

    Can unicellular organisms survive a drastic temperature change, and adapt to it after many generations? In simulations of the Penna model of biological aging, both extinction and adaptation were found for asexual and sexual reproduction as well as for parasex. These model investigations are the basis for the design of evolution experiments with heterotrophic flagellates.

  8. Does Ice Dissolve or Does Halite Melt? A Low-Temperature Liquidus Experiment for Petrology Classes.

    Science.gov (United States)

    Brady, John B.

    1992-01-01

    Measurement of the compositions and temperatures of H2O-NaCl brines in equilibrium with ice can be used as an easy in-class experimental determination of a liquidus. This experiment emphasizes the symmetry of the behavior of brines with regard to the minerals ice and halite and helps to free students from the conceptual tethers of one-component…

  9. Hydrogen/Oxygen Reactions at High Pressures and Intermediate Temperatures: Flow Reactor Experiments and Kinetic Modeling

    DEFF Research Database (Denmark)

    Hashemi, Hamid; Christensen, Jakob Munkholt; Glarborg, Peter

    A series of experimental and numerical investigations into hydrogen oxidation at high pressures and intermediate temperatures has been conducted. The experiments were carried out in a high pressure laminar flow reactor at 50 bar pressure and a temperature range of 600–900 K. The equivalence ratio......, ignition occurs at the temperature of 775–800 K. In general, the present model provides a good agreement with the measurements in the flow reactor and with recent data on laminar burning velocity and ignition delay time.......A series of experimental and numerical investigations into hydrogen oxidation at high pressures and intermediate temperatures has been conducted. The experiments were carried out in a high pressure laminar flow reactor at 50 bar pressure and a temperature range of 600–900 K. The equivalence ratio......, the mechanism is used to simulate published data on ignition delay time and laminar burning velocity of hydrogen. The flow reactor results show that at reducing, stoichiometric, and oxidizing conditions, conversion starts at temperatures of 750–775 K, 800–825 K, and 800–825 K, respectively. In oxygen atmosphere...

  10. In-flight thermal experiments for LISA Pathfinder: Simulating temperature noise at the Inertial Sensors

    Science.gov (United States)

    Gibert, F.; Nofrarias, M.; Armano, M.; Audley, H.; Auger, G.; Baird, J.; Binetruy, P.; Born, M.; Bortoluzzi, D.; Brandt, N.; Bursi, A.; Caleno, M.; Cavalleri, A.; Cesarini, A.; Cruise, M.; Danzmann, K.; Diepholz, I.; Dolesi, R.; Dunbar, N.; Ferraioli, L.; Ferroni, V.; Fitzsimons, E.; Freschi, M.; Gallegos, J.; García Marirrodriga, C.; Gerndt, R.; Gesa, Ll; Giardini, D.; Giusteri, R.; Grimani, C.; Harrison, I.; Heinzel, G.; Hewitson, M.; Hollington, D.; Hueller, M.; Huesler, J.; Inchauspé, H.; Jennrich, O.; Jetzer, P.; Johlander, B.; Karnesis, N.; Kaune, B.; Korsakova, N.; Killow, C.; Lloro, I.; Maarschalkerweerd, R.; Madden, S.; Maghami, P.; Mance, D.; Martín, V.; Martin-Porqueras, F.; Mateos, I.; McNamara, P.; Mendes, J.; Mendes, L.; Moroni, A.; Paczkowski, S.; Perreur-Lloyd, M.; Petiteau, A.; Pivato, P.; Plagnol, E.; Prat, P.; Ragnit, U.; Ramos-Castro, J.; Reiche, J.; Romera Perez, J. A.; Robertson, D.; Rozemeijer, H.; Russano, G.; Sarra, P.; Schleicher, A.; Slutsky, J.; Sopuerta, C. F.; Sumner, T.; Texier, D.; Thorpe, J.; Trenkel, C.; Tu, H. B.; Vetrugno, D.; Vitale, S.; Wanner, G.; Ward, H.; Waschke, S.; Wass, P.; Wealthy, D.; Wen, S.; Weber, W.; Wittchen, A.; Zanoni, C.; Ziegler, T.; Zweifel, P.

    2015-05-01

    Thermal Diagnostics experiments to be carried out on board LISA Pathfinder (LPF) will yield a detailed characterisation of how temperature fluctuations affect the LTP (LISA Technology Package) instrument performance, a crucial information for future space based gravitational wave detectors as the proposed eLISA. Amongst them, the study of temperature gradient fluctuations around the test masses of the Inertial Sensors will provide as well information regarding the contribution of the Brownian noise, which is expected to limit the LTP sensitivity at frequencies close to 1 mHz during some LTP experiments. In this paper we report on how these kind of Thermal Diagnostics experiments were simulated in the last LPF Simulation Campaign (November, 2013) involving all the LPF Data Analysis team and using an end-to-end simulator of the whole spacecraft. Such simulation campaign was conducted under the framework of the preparation for LPF operations.

  11. Selective brain cooling reduces water turnover in dehydrated sheep.

    Directory of Open Access Journals (Sweden)

    W Maartin Strauss

    Full Text Available In artiodactyls, arterial blood destined for the brain can be cooled through counter-current heat exchange within the cavernous sinus via a process called selective brain cooling. We test the hypothesis that selective brain cooling, which results in lowered hypothalamic temperature, contributes to water conservation in sheep. Nine Dorper sheep, instrumented to provide measurements of carotid blood and brain temperature, were dosed with deuterium oxide (D2O, exposed to heat for 8 days (40 ◦C for 6-h per day and deprived of water for the last five days (days 3 to 8. Plasma osmolality increased and the body water fraction decreased over the five days of water deprivation, with the sheep losing 16.7% of their body mass. Following water deprivation, both the mean 24h carotid blood temperature and the mean 24h brain temperature increased, but carotid blood temperature increased more than did brain temperature resulting in increased selective brain cooling. There was considerable inter-individual variation in the degree to which individual sheep used selective brain cooling. In general, sheep spent more time using selective brain cooling, and it was of greater magnitude, when dehydrated compared to when they were euhydrated. We found a significant positive correlation between selective brain cooling magnitude and osmolality (an index of hydration state. Both the magnitude of selective brain cooling and the proportion of time that sheep spent selective brain cooling were negatively correlated with water turnover. Sheep that used selective brain cooling more frequently, and with greater magnitude, lost less water than did conspecifics using selective brain cooling less efficiently. Our results show that a 50 kg sheep can save 2.6L of water per day (~60% of daily water intake when it employs selective brain cooling for 50% of the day during heat exposure. We conclude that selective brain cooling has a water conservation function in artiodactyls.

  12. Designing, constructing and evaluating a dynamic prototype dryer for obtaining rolled dehydrated fruit pulp

    OpenAIRE

    Vanegas Mahecha, Pedro; Parra Coronado, Alfonso

    2011-01-01

    This paper describes how a functional prototype for a dynamic dryer was designed, along with its basic parts: drying tunnel, mechanical transport system for material inside the equipment and selecting and designing a system for supplying hot air. A simple transport mechanism was implemented which allowed combining two flow dispositions: parallel and countercurrent flow. Mango (Mangifera indica L) pulp was dehydrated using three dryer air temperatures (50°C, 60°C and 70°C) and three drying air...

  13. Thermal and pasting properties of cassava starch-dehydrated orange pulp blends

    OpenAIRE

    Magali Leonel; Luciana Bronzi de Souza; Martha Maria Mischan

    2011-01-01

    Instant mixtures are easy to prepare and frequently present functional appeals. A quality parameter for instant mixtures is their rheological behavior. This study aimed at evaluating the effects of extrusion parameters on the pasting properties of cassava (Manihot esculenta L.) starch and dehydrated orange (Citrus sinensis (L.) Osbeck) pulp mixtures. The variable parameters were moisture of mixtures (12.5 to 19%), barrel temperature (40 to 90ºC) and screw rotation (170 to 266 rpm). The extrud...

  14. Sodium Intake During an Ultramarathon Does Not Prevent Muscle Cramping, Dehydration, Hyponatremia, or Nausea

    OpenAIRE

    Hoffman, Martin D.; Stuempfle, Kristin J.; Valentino, Taylor

    2015-01-01

    Background Ultramarathon runners commonly believe that sodium replacement is important for prevention of muscle cramping, dehydration, hyponatremia, and nausea during prolonged continuous exercise. The purpose of this study was to measure total sodium intake to determine if these beliefs are supported. Methods Participants of a 161-km ultramarathon (air temperature reaching 39 °C) provided full dietary information during the race, underwent body weight measurements before and after the race, ...

  15. Dehydration and drinking responses in a pelagic sea snake.

    Science.gov (United States)

    Lillywhite, Harvey B; Brischoux, François; Sheehy, Coleman M; Pfaller, Joseph B

    2012-08-01

    Recent investigations of water balance in sea snakes demonstrated that amphibious sea kraits (Laticauda spp.) dehydrate in seawater and require fresh water to restore deficits in body water. Here, we report similar findings for Pelamis platurus, a viviparous, pelagic, entirely marine species of hydrophiine ("true") sea snake. We sampled snakes at Golfo de Papagayo, Guanacaste, Costa Rica and demonstrated they do not drink seawater but fresh water at variable deficits of body water incurred by dehydration. The threshold dehydration at which snakes first drink fresh water is -18.3 ± 1.1 % (mean ± SE) loss of body mass, which is roughly twice the magnitude of mass deficit at which sea kraits drink fresh water. Compared to sea kraits, Pelamis drink relatively larger volumes of water and make up a larger percentage of the dehydration deficit. Some dehydrated Pelamis also were shown to drink brackish water up to 50% seawater, but most drank at lower brackish values and 20% of the snakes tested did not drink at all. Like sea kraits, Pelamis dehydrate when kept in seawater in the laboratory. Moreover, some individuals drank fresh water immediately following capture, providing preliminary evidence that Pelamis dehydrate at sea. Thus, this widely distributed pelagic species remains subject to dehydration in marine environments where it retains a capacity to sense and to drink fresh water. In comparison with sea kraits, however, Pelamis represents a more advanced stage in the evolutionary transition to a fully marine life and appears to be less dependent on fresh water.

  16. Impaired cognitive function and mental performance in mild dehydration.

    Science.gov (United States)

    Wilson, M-M G; Morley, J E

    2003-12-01

    Dehydration is a reliable predictor of impaired cognitive status. Objective data, using tests of cortical function, support the deterioration of mental performance in mildly dehydrated younger adults. Dehydration frequently results in delirium as a manifestation of cognitive dysfunction. Although, the occurrence of delirium suggests transient acute global cerebral dysfunction, cognitive impairment may not be completely reversible. Animal studies have identified neuronal mitochondrial damage and glutamate hypertransmission in dehydrated rats. Additional studies have identified an increase in cerebral nicotinamide adenine dinucleotide phosphate-diaphorase activity (nitric oxide synthase, NOS) with dehydration. Available evidence also implicates NOS as a neurotransmitter in long-term potentiation, rendering this a critical enzyme in facilitating learning and memory. With ageing, a reduction of NOS activity has been identified in the cortex and striatum of rats. The reduction of NOs synthase activity that occurs with ageing may blunt the rise that occurs with dehydration, and possibly interfere with memory processing and cognitive function. Dehydration has been shown to be a reliable predictor of increasing frailty, deteriorating mental performance and poor quality of life. Intervention models directed toward improving outcomes in dehydration must incorporate strategies to enhance prompt recognition of cognitive dysfunction.

  17. Phase transitions on dehydration of the natural zeolite thomsonite

    DEFF Research Database (Denmark)

    Ståhl, Kenny

    2001-01-01

    The dehydration of the natural zeolite thomsonite, Na4CasAl20Si20O80 24H(2)O, has been studied using a combination of conventional and synchrotron X-ray powder diffraction. A preliminary in situ dehydration study revealed two distinct unit cell changes at approximately 540 and 570 K, respectively...

  18. Dehydration of n-propanol and methanol to produce etherified fuel additives

    Directory of Open Access Journals (Sweden)

    Husam Almashhadani

    2017-01-01

    Full Text Available An ether is an organic compound that consists of an oxygen atom bonded to two alkyl or aryl groups. In this work, we investigate the bimolecular dehydration of two alcohols, n-propanol and methanol with catalysts that are used in transesterification. Experiments were carried out to evaluate the feasibility of promoting etherification reaction using methanol and n-propanol as model alcohols. When methanol and n-propanol are reacted together, three types of ethers can be produced; i.e., dimethyl ether, methyl-propyl ether (also referred to as methoxypropane, and di-propyl ether. The latter two ethers are of more fuel interest due to their ability to stay in liquid phase at room temperature; however, the ability of catalysts to selectively produce liquid ethers is not established. Initial studies were conducted to discern the effect of sulfuric acid, amberlyst-36 and titanium isopropoxide, catalysts that are known to be effective for transesterification, at four levels of temperature on the substrate conversion, ether yield and selectivity using n-propanol. Subsequent studies with n-propanol and methanol additionally looked at the impact of select catalyst concentrations and reaction conditions. Studies indicate that liquid mixtures of 1-methoxypropane and di-propyl ethers could be formed by reacting n-propanol and methanol in the presence of sulfuric acid or Amberlyst 36. Higher concentrations of sulfuric acid (5% w/w coupled with higher temperatures (>140 °C favored substrate conversion and ether yields. However, it was revealed that the selectivity toward specific ethers, i.e., coupling of the two larger alcohols to produce di-propyl ether vs larger one with the smaller one to produce methoxypropane could be controlled by appropriate selection of the catalyst. We anticipate the results being a starting point for a simple technique to produce specific ethers using a mixture of alcohols that could be applied for applications such as

  19. The effect of dehydration on muscle metabolism and time trial performance during prolonged cycling in males.

    Science.gov (United States)

    Logan-Sprenger, Heather M; Heigenhauser, George J F; Jones, Graham L; Spriet, Lawrence L

    2015-08-01

    This study combined overnight fluid restriction with lack of fluid intake during prolonged cycling to determine the effects of dehydration on substrate oxidation, skeletal muscle metabolism, heat shock protein 72 (Hsp72) response, and time trial (TT) performance. Nine males cycled at ~65% VO2peak for 90 min followed by a TT (6 kJ/kg BM) either with fluid (HYD) or without fluid (DEH). Blood samples were taken every 20 min and muscle biopsies were taken at 0, 45, and 90 min of exercise and after the TT. DEH subjects started the trial with a -0.6% BM from overnight fluid restriction and were dehydrated by 1.4% after 45 min, 2.3% after 90 min of exercise, and 3.1% BM after the TT. There were no significant differences in oxygen uptake, carbon dioxide production, or total sweat loss between the trials. However, physiological parameters (heart rate [HR], rate of perceived exertion, core temperature [Tc], plasma osmolality [Posm], plasma volume [Pvol] loss, and Hsp72), and carbohydrate (CHO) oxidation and muscle glycogen use were greater during 90 min of moderate cycling when subjects progressed from 0.6% to 2.3% dehydration. TT performance was 13% slower when subjects began 2.3% and ended 3.1% dehydrated. Throughout the TT, Tc, Posm, blood and muscle lactate [La], and serum Hsp72 were higher, even while working at a lower power output (PO). The accelerated muscle glycogen use during 90 min of moderate intensity exercise with DEH did not affect subsequent TT performance, rather augmented Tc, RPE and the additional physiological factors were more important in slowing performance when dehydrated.

  20. Response of Chinese Wampee Axes and Maize Embryos to Dehydration at Different Rates

    Institute of Scientific and Technical Information of China (English)

    Hui Huang; Song-Quan Song; Xian-Jin Wu

    2009-01-01

    Survival of wampee (Clausena lansium Sksels) axes and maize (Zea mays L.) embryos decreased with rapid and slow dehydration. Damage of wampee axes by rapid dehydration was much less than by slow dehydration, and that was contrary to maize embryos. The malondialdehyde contents of wampee axes and maize embryos rapidly increased with dehydration, those of wampee axes were lower during rapid dehydration than during slow dehydration, and those of maize embryos were higher during rapid dehydration than during slow dehydration. Activities of superoxide dismutsse (SOD), ascorbate peroxidase (APX) and catalase (CAT) of wampee axes markedly increased during the sady phase of dehydration, and then rapidly decreased, and those of rapidly dehydrated axes were higher than those of slow dehydrated axes when they were dehydrated to low water contents. Activities of SOD and APX of maize embryos notable decreased with dehydration. There were higher SOD activities and lower APX activities of slowly dehydrated maize embryos compared with rapidly dehydrated maize embryos. CAT activities of maize embryos markedly increased during the eady phase of dehydration, and then decreased, and those of slowly dehydrated embryos were higher than those of rapidly dehydrated embryos during the late phase of dehydration.

  1. Field warming experiments shed light on the wheat yield response to temperature in China

    Science.gov (United States)

    Zhao, Chuang; Piao, Shilong; Huang, Yao; Wang, Xuhui; Ciais, Philippe; Huang, Mengtian; Zeng, Zhenzhong; Peng, Shushi

    2016-11-01

    Wheat growth is sensitive to temperature, but the effect of future warming on yield is uncertain. Here, focusing on China, we compiled 46 observations of the sensitivity of wheat yield to temperature change (SY,T, yield change per °C) from field warming experiments and 102 SY,T estimates from local process-based and statistical models. The average SY,T from field warming experiments, local process-based models and statistical models is -0.7+/-7.8(+/-s.d.)% per °C, -5.7+/-6.5% per °C and 0.4+/-4.4% per °C, respectively. Moreover, SY,T is different across regions and warming experiments indicate positive SY,T values in regions where growing-season mean temperature is low, and water supply is not limiting, and negative values elsewhere. Gridded crop model simulations from the Inter-Sectoral Impact Model Intercomparison Project appear to capture the spatial pattern of SY,T deduced from warming observations. These results from local manipulative experiments could be used to improve crop models in the future.

  2. Polymer Inverse Temperature-Dependent Solubility: A Visual Demonstration of the Importance of "T[Delta]S" in the Gibbs Equation

    Science.gov (United States)

    Bergbreiter, David E.; Mijalis, Alexander J.; Fu, Hui

    2012-01-01

    Reversible polymer dehydration and precipitation from water due to the unfavorable entropy of hydration is examined using a melting-point apparatus. The thermoresponsive lower critical solution temperature (LCST) behavior of poly(N-isopropylacrylamide) (PNIPAM) is responsible for these effects. An experiment is described that allows students to…

  3. Polymer Inverse Temperature-Dependent Solubility: A Visual Demonstration of the Importance of "T[Delta]S" in the Gibbs Equation

    Science.gov (United States)

    Bergbreiter, David E.; Mijalis, Alexander J.; Fu, Hui

    2012-01-01

    Reversible polymer dehydration and precipitation from water due to the unfavorable entropy of hydration is examined using a melting-point apparatus. The thermoresponsive lower critical solution temperature (LCST) behavior of poly(N-isopropylacrylamide) (PNIPAM) is responsible for these effects. An experiment is described that allows students to…

  4. Thermogravimetric study of the dehydration and reduction of red mud

    Science.gov (United States)

    Teplov, O. A.; Korenovskii, N. L.; Lainer, Yu. A.

    2015-01-01

    The processes of drying and reduction of red mud in the pure state and with coal additions in vacuum or in gaseous media (helium, hydrogen) have been experimentally studied by thermogravimetry using a Setaram TAG24 thermogravimetric analyzer. The minimum total weight loss (˜20%) is observed for red mud samples without additives in forevacuum, and the maximum loss (˜38%) is detected in samples with coal. It is demonstrated that, for this type of red mud with iron oxide Fe2O3, water molecules are bonded in the form of iron hydroxide Fe2O3 · 3H2O rather than goethite FeOOH. The peak of magnetite formation is observed in differential thermogravimetry (DTG) curve in the range 270-400°C. The simulation of the magnetite dehydration and formation rates under experimental conditions in the relevant temperature ranges agrees with the experimental data. A peak of wustite formation in hydrogen above ˜600°C is recorded in a DTG curve, and the removal of one-third of sodium oxide, which is likely not to be fixed into strong sodium alumosilicate, is observed in the range 800-1000°C. The peak detected in the DTG curve of the mud with charcoal in helium in the range 350-450°C is similar to the peak of hematite reduction in magnetite in a hydrogen atmosphere. The most probable source of hydrogen-containing gases in this temperature range consists of the residual hydrocarbons of charcoal. The reduction reactions of disperse iron oxides with coal proceed only at temperatures above 600°C. These processes occur in the same temperature range (600-900°C) both in forevacuum and in a helium atmosphere. It is experimentally demonstrated that sintering process occurs in the mud in the temperature range 450-850°C.

  5. Plasma Shock Wave Modification Experiments in a Temperature Compensated Shock Tube

    Science.gov (United States)

    Vine, Frances J.; Mankowski, John J.; Saeks, Richard E.; Chow, Alan S.

    2003-01-01

    A number of researchers have observed that the intensity of a shock wave is reduced when it passes through a weakly ionized plasma. While there is little doubt that the intensity of a shock is reduced when it propagates through a weakly ionized plasma, the major question associated with the research is whether the reduction in shock wave intensity is due to the plasma or the concomitant heating of the flow by the plasma generator. The goal of this paper is to describe a temperature compensated experiment in a "large" diameter shock tube with an external heating source, used to control the temperature in the shock tube independently of the plasma density.

  6. A Model for Temperature Influence on Concrete Hydration Exothermic Rate (Part one:Theory and Experiment)

    Institute of Scientific and Technical Information of China (English)

    ZHU Zhenyang; QIANG Sheng; CHEN Weimin

    2014-01-01

    Recent achievements in concrete hydration exothermic models based on Arrhenius equation have improved computation accuracy for mass concrete temperature field. But the properties of the activation energy and the gas constant (Ea/R) have not been well studied yet. From the latest experiments it is shown that Ea/R obviously changes with the hydration degree without fixed form. In this paper, the relationship between hydration degree and Ea/R is studied and a new hydration exothermic model is proposed. With those achievements, the mass concrete temperature field with arbitrary boundary condition can be calculated more precisely.

  7. Simulating Experiment for Temperature Field of Frozen Subgrade Using Regulation-Tubes

    Institute of Scientific and Technical Information of China (English)

    LIU Zhi-qiang; MA Wei; ZHOU Guo-qing; NIU Fu-jun; WANG Jian-zhou; CHANG Li-wu; ZHOU Jin-sheng

    2005-01-01

    The main factors that influence the temperature field of frozen subgrade were analyzed. The experimental equipment for simulating frozen subgrade was built up,and the declining regulating tubes were placed at the foot of the embankment. By means of this equipment two simulating experiments of controlling temperature filed of frozen sub grade were carried out in the laboratory. One method is to collect natural cold energy, and the other one is to collect natural cold energy ccompanied by artificial refrigeration simultaneously. The result indicates that the latter is an ef fective method for maintaining the stability of the frozen subgrade.

  8. Methanol and 2-methyl-1-propanol (isobutanol) coupling to ethers and dehydration over Nafion H: Selectivity, kinetics, and mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Nunan, J.G.; Klier, K.; Herman, R.G. (Lehigh Univ., Bethlehem, PA (United States))

    1993-02-01

    The dehydration of a mixture of methanol and isobutanol has been studied over the sulfonic acid Nafion H catalyst. Dehydration products consisted of dimethyl ether (DME), di-isobutyl ether (DIBE), methyl-isobutyl ether (MIBE), butenes, octenes, and traces of methyl-tertiarybutyl ether (MTBE). At low temperatures and high alcohol pressures (P [ge] 150 kPa), the dehydration product slate was dominated by ether formation with selectivity within the ethers significantly in favor of the mixed ether, MIBE. The rates of ether and butene formation as a function of alcohol pressure could be described by Langmuir-Hinshelwood kinetics in which competitive adsorption of the two alcohols on the surface -SO[sub 3]H sites was the dominant feature. The kinetics of isobutanol dehydration to isobutene were consistent with a dual-site mechanism involving the cooperative action of a free surface -SO[sub 3]H site and an adjacent adsorbed alcohol molecule. Dehydration to ethers was consistent with the reaction of two adsorbed alcohols, also by a dual-site mechanism. As a consequence, dehydration to symmetric ethers showed saturation-type kinetics as a function of alcohol pressure, while the rate of isobutene formation went through a distinct maximum. Due to the competitive adsorption of methanol and isobutanol, the mixed ether MIBE was formed at a maximum rate with an optimum ratio of partial pressures of the two alcohols. The high selectivity to MIBE was explained by stronger adsorption of isobutanol on the catalyst surface as compared to methanol. The absence of MTBE and the predominance of products such as MIBE and 2,5-dimethylhexene suggests that dehydration to give free carbenium ions that subsequently rearrange to the more stable tertiary intermediate was not occurring. It was proposed that the alcohols react with the -SO[sub 3]H groups to give oxonium ions or esters. These intermediates couple to give the product ethers or octenes. 24 refs., 13 figs., 1 tab.

  9. Experimental investigation of bioethanol liquid phase dehydration using natural clinoptilolite.

    Science.gov (United States)

    Karimi, Samira; Ghobadian, Barat; Omidkhah, Mohammad-Reza; Towfighi, Jafar; Tavakkoli Yaraki, Mohammad

    2016-05-01

    An experimental study of bioethanol adsorption on natural Iranian clinoptilolite was carried out. Dynamic breakthrough curves were used to investigate the best adsorption conditions in bioethanol liquid phase. A laboratory setup was designed and fabricated for this purpose. In order to find the best operating conditions, the effect of liquid pressure, temperature and flow rate on breakthrough curves and consequently, maximum ethanol uptake by adsorbent were studied. The effects of different variables on final bioethanol concentration were investigated using Response Surface Methodology (RSM). The results showed that by working at optimum condition, feed with 96% (v/v) initial ethanol concentration could be purified up to 99.9% (v/v). In addition, the process was modeled using Box-Behnken model and optimum operational conditions to reach 99.9% for final ethanol concentration were found equal to 10.7 °C, 4.9 bar and 8 mL/min for liquid temperature, pressure and flow rate, respectively. Therefore, the selected natural Iranian clinoptilolite was found to be a promising adsorbent material for bioethanol dehydration process.

  10. Ethylene Formation by Catalytic Dehydration of Ethanol with Industrial Considerations

    Directory of Open Access Journals (Sweden)

    Ho-Shing Wu

    2012-12-01

    Full Text Available Ethylene is the primary component in most plastics, making it economically valuable. It is produced primarily by steam-cracking of hydrocarbons, but can alternatively be produced by the dehydration of ethanol, which can be produced from fermentation processes using renewable substrates such as glucose, starch and others. Due to rising oil prices, researchers now look at alternative reactions to produce green ethylene, but the process is far from being as economically competitive as using fossil fuels. Many studies have investigated catalysts and new reaction engineering technologies to increase ethylene yield and to lower reaction temperature, in an effort to make the reaction applicable in industry and most cost-efficient. This paper presents various lab synthesized catalysts, reaction conditions, and reactor technologies that achieved high ethylene yield at reasonable reaction temperatures, and evaluates their practicality in industrial application in comparison with steam-cracking plants. The most promising were found to be a nanoscale catalyst HZSM-5 with 99.7% ethylene selectivity at 240 °C and 630 h lifespan, using a microreactor technology with mechanical vapor recompression, and algae-produced ethanol to make ethylene.

  11. 静电聚结原油脱水试验研究%Study on Dehydration of Crude Oil by Electrostatic Coalescence

    Institute of Scientific and Technical Information of China (English)

    彭松梓; 崔新安; 王春升; 李春贤; 郑晓鹏

    2012-01-01

    针对目前高含水原油采出液采用传统三相分离与热化学分离和电脱水方法存在分离级数和设备多、油水分离效率低、电脱水运行不稳定等问题,在静电预聚结研究基础上,采用自制绝缘电极和乳化液,开展静电聚结脱水研究,使水滴预聚结和沉降分离同时进行。通过静态聚结脱水试验考察了乳化液水含量、电压、温度和沉降时间等因素对静电聚结脱水效果的影响,结果表明乳化液脱水率随温度升高、电压增大和沉降时间延长而提高。其中温度影响最大,电压和沉降时间影响较小。在动态静电聚结原油脱水试验装置上进行验证,同时对不同分离器结构和不同电极结构及进料方式进行了对比,对试验条件进行了优化。动态试验结果表明,在电压2 kV,温度65~70℃,停留时间不大于10 min的条件下,高含水乳化液的脱水率均可达95%以上。%To solve the problems of numerous separation stages,more equipment,lower separation efficiency and unstable running of electric dehydration in conventional separation process of three phase separation,thermal chemistry separation and electric dehydration treatment,researches on electrostatic coalescence for high water content oil is developed based on the former studies on pre-coalescence by using complex electrode and emulsion made in laboratory.The impacts of water content of emulsion,electric voltage,temperature and residence time etc on the dehydration performance of emulsion by electrostatic coalescence were investigated through static experiments and were then validated and optimized through the dynamic experiments.The results show that the dehydration rate of emulsion increases with increase of temperature,voltage and residence time.In these impact factors,temperature has the greatest impact,followed by voltage and residence time.At the same time,the different separator constructions,different electrode structures and

  12. Supercritical Water Mixture (SCWM) Experiment in the High Temperature Insert-Reflight (HTI-R)

    Science.gov (United States)

    Hicks, Michael C.; Hegde, Uday G.; Garrabos, Yves; Lecoutre, Carole; Zappoli, Bernard

    2013-01-01

    Current research on supercritical water processes on board the International Space Station (ISS) focuses on salt precipitation and transport in a test cell designed for supercritical water. This study, known as the Supercritical Water Mixture Experiment (SCWM) serves as a precursor experiment for developing a better understanding of inorganic salt precipitation and transport during supercritical water oxidation (SCWO) processes for the eventual application of this technology for waste management and resource reclamation in microgravity conditions. During typical SCWO reactions any inorganic salts present in the reactant stream will precipitate and begin to coat reactor surfaces and control mechanisms (e.g., valves) often severely impacting the systems performance. The SCWM experiment employs a Sample Cell Unit (SCU) filled with an aqueous solution of Na2SO4 0.5-w at the critical density and uses a refurbished High Temperature Insert, which was used in an earlier ISS experiment designed to study pure water at near-critical conditions. The insert, designated as the HTI-Reflight (HTI-R) will be deployed in the DECLIC (Device for the Study of Critical Liquids and Crystallization) Facility on the International Space Station (ISS). Objectives of the study include measurement of the shift in critical temperature due to the presence of the inorganic salt, assessment of the predominant mode of precipitation (i.e., heterogeneously on SCU surfaces or homogeneously in the bulk fluid), determination of the salt morphology including size and shapes of particulate clusters, and the determination of the dominant mode of transport of salt particles in the presence of an imposed temperature gradient. Initial results from the ISS experiments will be presented and compared to findings from laboratory experiments on the ground.

  13. Temperature measurement during solidification of thin wall ductile cast iron. Part 1: Theory and experiment

    DEFF Research Database (Denmark)

    Pedersen, Karl Martin; Tiedje, Niels Skat

    2008-01-01

    Temperature measurement using thermocouples (TC’s) influence solidification of the casting, especially in thin wall castings. The problems regarding acquisition of detailed cooling curves from thin walled castings is discussed. Experiments were conducted where custom made TC’s were used to acquire...... cooing curves in thin wall ductile iron castings. The experiments show how TC’s of different design interact with the melt and how TC design and surface quality affect the results of the data acquisition. It is discussed which precautions should be taken to ensure reliable acquisition of cooling curves...

  14. UNCERTAINTY QUANTIFICATION OF CALCULATED TEMPERATURES FOR ADVANCED GAS REACTOR FUEL IRRADIATION EXPERIMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Pham, Binh Thi-Cam [Idaho National Laboratory; Hawkes, Grant Lynn [Idaho National Laboratory; Einerson, Jeffrey James [Idaho National Laboratory

    2015-08-01

    This paper presents the quantification of uncertainty of the calculated temperature data for the Advanced Gas Reactor (AGR) fuel irradiation experiments conducted in the Advanced Test Reactor at Idaho National Laboratory in support of the Advanced Reactor Technology Research and Development program. Recognizing uncertainties inherent in physics and thermal simulations of the AGR tests, the results of the numerical simulations are used in combination with statistical analysis methods to improve qualification of measured data. The temperature simulation data for AGR tests are also used for validation of the fission product transport and fuel performance simulation models. These crucial roles of the calculated fuel temperatures in ensuring achievement of the AGR experimental program objectives require accurate determination of the model temperature uncertainties. To quantify the uncertainty of AGR calculated temperatures, this study identifies and analyzes ABAQUS model parameters of potential importance to the AGR predicted fuel temperatures. The selection of input parameters for uncertainty quantification of the AGR calculated temperatures is based on the ranking of their influences on variation of temperature predictions. Thus, selected input parameters include those with high sensitivity and those with large uncertainty. Propagation of model parameter uncertainty and sensitivity is then used to quantify the overall uncertainty of AGR calculated temperatures. Expert judgment is used as the basis to specify the uncertainty range for selected input parameters. The input uncertainties are dynamic accounting for the effect of unplanned events and changes in thermal properties of capsule components over extended exposure to high temperature and fast neutron irradiation. The sensitivity analysis performed in this work went beyond the traditional local sensitivity. Using experimental design, analysis of pairwise interactions of model parameters was performed to establish

  15. The neutral atmosphere temperature experiment. [for thermospheric nitrogen measurement on AEROS satellite

    Science.gov (United States)

    Spencer, N. W.; Pelz, D. T.; Niemann, H. B.; Carignan, G. R.; Caldwell, J. R.

    1974-01-01

    The AEROS Neutral Atmosphere Temperature Experiment (NATE) is designed to measure the kinetic temperature of molecular nitrogen in the thermosphere. A quadrupole mass spectrometer tuned to N2 measures the N2 density variation in a small spherical antechamber having a knife-edged orifice which is exposed to the atmosphere at the outer surface of the spacecraft. The changing density of N2 due to the spinning motion of the spacecraft permits determination of the velocity distribution of the N2 from which the temperature is calculated. An alternate mode of operation of the instrument allows measurement of the other gases in the atmosphere as well as N2 permitting determination of the neutral particle composition of the atmosphere.

  16. The THS experiment: Simulating Titan's atmospheric chemistry at low temperature (200 K)

    Science.gov (United States)

    Sciamma-O'Brien, Ella; Upton, Kathleen T.; Beauchamp, Jack L.; Salama, Farid

    2016-10-01

    In the Titan Haze Simulation (THS) experiment, Titan's atmospheric chemistry is simulated by plasma discharge in the stream of a supersonic expansion, i.e. at low Titan-like temperature (150 K). Here, we present complementary gas and solid phase analyses of four N2-CH4-based gas mixtures that demonstrate the unique capability of the THS to monitor the chemical growth evolution in order to better understand Titan's chemistry and the origin of aerosol formation.

  17. Cosmological parameter estimation with QUaD CMB polarization and temperature experiment

    OpenAIRE

    Memari, Yasin

    2009-01-01

    In this thesis we examine the theoretical origin and statistical features of the Cosmic Microwave Background radiation. We particularly focus on the CMB power spectra and cosmological parameter estimation from QUaD CMB experiment data in order to derive implications for the concordance cosmological model. In chapter 4 we present a detailed parameter estimation analysis of the combined polarization and temperature power spectra from the second and third season observations of...

  18. Bubble behavior in molten glass in a temperature gradient. [in reduced gravity rocket experiment

    Science.gov (United States)

    Meyyappan, M.; Subramanian, R. S.; Wilcox, W. R.; Smith, H.

    1982-01-01

    Gas bubble motion in a temperature gradient was observed in a sodium borate melt in a reduced gravity rocket experiment under the NASA SPAR program. Large bubbles tended to move faster than smaller ones, as predicted by theory. When the bubbles contacted a heated platinum strip, motion virtually ceased because the melt only imperfectly wets platinum. In some cases bubble diameter increased noticeably with time.

  19. Mathematical Model of Fiber Optic Temperature Sensor Based on Optic Absorption and Experiment Testing

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    On the basis of analysis on the temperature monitoring methods for high voltage devices, a new type of fiber optic sensor structure with reference channel is given. And the operation principle of fiber optic sensor is analysed at large based on the absorption of semiconductor chip. The mathematical model of both devices and the whole system are also given. It is proved by the experiment that this mathematical model is reliable.

  20. Temperature-induced increase in methane release from peat bogs: a mesocosm experiment.

    Science.gov (United States)

    van Winden, Julia F; Reichart, Gert-Jan; McNamara, Niall P; Benthien, Albert; Damsté, Jaap S Sinninghe

    2012-01-01

    Peat bogs are primarily situated at mid to high latitudes and future climatic change projections indicate that these areas may become increasingly wetter and warmer. Methane emissions from peat bogs are reduced by symbiotic methane oxidizing bacteria (methanotrophs). Higher temperatures and increasing water levels will enhance methane production, but also methane oxidation. To unravel the temperature effect on methane and carbon cycling, a set of mesocosm experiments were executed, where intact peat cores containing actively growing Sphagnum were incubated at 5, 10, 15, 20, and 25°C. After two months of incubation, methane flux measurements indicated that, at increasing temperatures, methanotrophs are not able to fully compensate for the increasing methane production by methanogens. Net methane fluxes showed a strong temperature-dependence, with higher methane fluxes at higher temperatures. After removal of Sphagnum, methane fluxes were higher, increasing with increasing temperature. This indicates that the methanotrophs associated with Sphagnum plants play an important role in limiting the net methane flux from peat. Methanotrophs appear to consume almost all methane transported through diffusion between 5 and 15°C. Still, even though methane consumption increased with increasing temperature, the higher fluxes from the methane producing microbes could not be balanced by methanotrophic activity. The efficiency of the Sphagnum-methanotroph consortium as a filter for methane escape thus decreases with increasing temperature. Whereas 98% of the produced methane is retained at 5°C, this drops to approximately 50% at 25°C. This implies that warming at the mid to high latitudes may be enhanced through increased methane release from peat bogs.

  1. Temperature-induced increase in methane release from peat bogs: a mesocosm experiment.

    Directory of Open Access Journals (Sweden)

    Julia F van Winden

    Full Text Available Peat bogs are primarily situated at mid to high latitudes and future climatic change projections indicate that these areas may become increasingly wetter and warmer. Methane emissions from peat bogs are reduced by symbiotic methane oxidizing bacteria (methanotrophs. Higher temperatures and increasing water levels will enhance methane production, but also methane oxidation. To unravel the temperature effect on methane and carbon cycling, a set of mesocosm experiments were executed, where intact peat cores containing actively growing Sphagnum were incubated at 5, 10, 15, 20, and 25°C. After two months of incubation, methane flux measurements indicated that, at increasing temperatures, methanotrophs are not able to fully compensate for the increasing methane production by methanogens. Net methane fluxes showed a strong temperature-dependence, with higher methane fluxes at higher temperatures. After removal of Sphagnum, methane fluxes were higher, increasing with increasing temperature. This indicates that the methanotrophs associated with Sphagnum plants play an important role in limiting the net methane flux from peat. Methanotrophs appear to consume almost all methane transported through diffusion between 5 and 15°C. Still, even though methane consumption increased with increasing temperature, the higher fluxes from the methane producing microbes could not be balanced by methanotrophic activity. The efficiency of the Sphagnum-methanotroph consortium as a filter for methane escape thus decreases with increasing temperature. Whereas 98% of the produced methane is retained at 5°C, this drops to approximately 50% at 25°C. This implies that warming at the mid to high latitudes may be enhanced through increased methane release from peat bogs.

  2. Extracting the Electron-Ion Temperature Relaxation Rate from Ion Stopping Experiments

    Science.gov (United States)

    Grabowski, Paul E.; Frenje, Johan A.; Benedict, Lorin X.

    2016-10-01

    Direct measurement of i-e equilibration rates at ICF-relevant conditions is a big challenge, as it is difficult to differentiate from other sinks and sources of energy, such as heat conduction and pdV work. Another method is to use information from ion stopping experiments. Such experiments at the OMEGA laser have made precision energy loss measurements of fusion products at these conditions. Combined with the multimonochromatic x-ray imager technique, which gives temporally and spatially resolved electron temperature and density, we have a robust stopping experiment. We propose to use such stopping measurements to assess the i-e temperature relaxation rate, since both processes involve energy exchange between electrons and ions. We require that the fusion products are 1) much faster than the thermal ions so that i-i collisions are negligible compared to i-e collisions and 2) slower than the thermal electrons so that the stopping obeys a linear friction law. Then the Coulomb logarithms associated with ion stopping and i-e temperature relaxation rate are identical and a measurement of the former provides the latter. Prepared by LLNL under Contract DE-AC52-07NA27344.

  3. Use of gamma radiation cobalt 60 for disinfestation of Lasioderma serricorne (Fabricius, 1972) (Coleoptera: Anobiidae) in Cymbopogon citratus stapf and Ocimun basillicum L. dehydrated

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, Amanda C.O.; Potenza, Marcos R.; Alves, Juliana N.; Justi Junior, Joao [Instituto Biologico, Sao Paulo, SP (Brazil). Centro de Pesquisa e Desenvolvimento de Sanidade Vegetal]. E-mail: potenza@biologico.sp.gov.br; Arthur, Valter [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil)]. E-mail: arthur@cena.usp.br

    2007-07-01

    Stored products such as grains, flours, dry fruits and spices are normally infested by pests as beetles (Lasioderma serricorne), mites and moths, depreciating the product visually and promoting its deterioration. To improve the quality of spices, medicinal plants, seasoning and others foodstuffs there is a need for adequate methods of handling, correct identification of the species, adequate collection, pre and post-treatment procedures and adequate storage. The objective of this work was to determine the dose of gamma radiation for the disinfestations of medicinal and aromatic plants dehydrated infested by L. serricone. The plants used in this study were Cymbopogon citratus stapf (lemon grass) and Ocimun basillicum L. (basil) in this dehydrated form. The experiment was carried out in the Arthropods Laboratory of the Instituto Biologico/SP, during the months of January and May 2006, and the irradiations were carried out in the Instituto de Pesquisas Energeticas e Nucleares-IPEN/CNEN/SP, using an experimental Cobalt 60 irradiator, model Gammacell 220. Each treatment consisted of 5 parcels containing 10g of dehydrated products infested with 20 last instar larvae of L. serricorne, conditioned in plastic 10x10 cm containers with small punctures in the cover to allow internal aeration. The substratum previously infested was kept for 1 day in a acclimatized room at 27 {+-} 2 deg C, after this period the substratum was submitted to increasing doses of gamma radiation: 0; 0,5; 0,75; 1,0; 1,25; 1,50; 1,75; 2,0; 2,25; 2,50 e 2,75 kGy. After irradiation, the samples were kept in a acclimatized room at 27 {+-} 2 deg C of temperature and relative humidity of 70 {+-} 5 % and after a 45 days period the number of adults insects emerged was evaluated. The lethal dose of gamma radiation for L. serrricorne last instar larvae on Cymbopogon citratus stapf and Ocimun basillicum L. was 1,75 kGy. (author)

  4. Dehydration and Symptoms of Delayed-Onset Muscle Soreness in Hyperthermic Males

    Science.gov (United States)

    Cleary, Michelle A; Sweeney, Lori A; Kendrick, Zebulon V; Sitler, Michael R

    2005-01-01

    Context: Exercise in the heat produces cellular conditions that may leave skeletal muscle susceptible to exercise-induced microdamage. Delayed-onset muscle soreness (DOMS) is a clinical model of contraction-induced skeletal muscle injury. Objective: To determine whether thermoregulation during exercise heat stress adversely affects muscle injury and the accompanying DOMS. Design: Randomized group test-retest design. Setting: Laboratory. Patients or Other Participants: Ten healthy male volunteers were randomly assigned to either the euhydration/hyperthermic or dehydration/hyperthermic group. Intervention(s): Participants were randomly assigned to treadmill walking in a hot, humid environmental chamber (40°C and 75% relative humidity) with either oral rehydration (euhydration/hyperthermic) or fluid restriction (dehydration/hyperthermic). Immediately after heat exposure and while hyperthermic, participants performed an eccentrically biased downhill run to induce DOMS. Main Outcome Measure(s): We measured DOMS characteristics pre-exercise and at 0.5, 24, 48, 72, and 96 hours postexercise. Results: Treadmill exercise and exposure to the hot ambient environment elicited a 0.9% body mass loss for the euhydrated/ hyperthermic (mean rectal temperature after 60 minutes of heat-stress trial = 38.2 ± 0.4°C) and 3.3% body mass loss for the dehydrated/hyperthermic participants (mean rectal temperature after 60 minutes of heat-stress trial = 38.1 ± 0.4°C). Quadriceps perceived pain was significantly higher (F5,40 = 18.717, P ≤ .001) than baseline at 24 and 48 hours postexercise, following the classic pattern of DOMS. Overall lower extremity perceived pain was significantly higher for the dehydration/hyperthermia group than the euhydration/hyperthermia group (F1,8 = 6.713, P = .032). Punctate tenderness of the vastus lateralis for the dehydration/hyperthermic group was 6.9% higher (F5,40 = 4.462, P = .003) than for the euhydration/ hyperthermic group. No clinically

  5. Influence of dehydration on locally mediated hindlimb vasodilation in baboons.

    Science.gov (United States)

    Thornton, R M; Proppe, D W

    1988-08-01

    Previous studies indicate that the heat stress-induced cutaneous vasodilation in baboons is attenuated during dehydration by mechanisms other than the well-known neurohumoral vasoconstrictor mechanisms. Therefore, this study sought to determine whether dehydration also attenuates locally mediated maximum hindlimb blood flow and vascular conductance in baboons. Five baboons were chronically instrumented to measure arterial blood pressure and mean external iliac artery blood flow (MIBF). Hindlimb vasodilation was induced by occlusions of the external iliac artery for 2.5, 5.0, 7.5, and 10.0 min and by close-arterial injections of acetylcholine (ACh) and sodium nitroprusside (NP) in graded doses. These vasodilatory stimuli were applied in euhydrated and dehydrated states, the latter being produced by water deprivation for 64-68 h. Maximum MIBF and iliac vascular conductance (IVC) after arterial occlusion were reduced by 67-70% during dehydration. Also, maximum MIBF and IVC produced by ACh in the dehydrated state were 46-52% lower than in the euhydrated state. A similar reduction in the responses to NP occurred during dehydration. It is concluded that the maximum hindlimb blood flow and vascular conductance produced by local, nonneurohumoral mechanisms are attenuated in the baboon during dehydration.

  6. Dehydration affects brain structure and function in healthy adolescents.

    Science.gov (United States)

    Kempton, Matthew J; Ettinger, Ulrich; Foster, Russell; Williams, Steven C R; Calvert, Gemma A; Hampshire, Adam; Zelaya, Fernando O; O'Gorman, Ruth L; McMorris, Terry; Owen, Adrian M; Smith, Marcus S

    2011-01-01

    It was recently observed that dehydration causes shrinkage of brain tissue and an associated increase in ventricular volume. Negative effects of dehydration on cognitive performance have been shown in some but not all studies, and it has also been reported that an increased perceived effort may be required following dehydration. However, the effects of dehydration on brain function are unknown. We investigated this question using functional magnetic resonance imaging (fMRI) in 10 healthy adolescents (mean age = 16.8, five females). Each subject completed a thermal exercise protocol and nonthermal exercise control condition in a cross-over repeated measures design. Subjects lost more weight via perspiration in the thermal exercise versus the control condition (P Dehydration following the thermal exercise protocol led to a significantly stronger increase in fronto-parietal blood-oxygen-level-dependent (BOLD) response during an executive function task (Tower of London) than the control condition, whereas cerebral perfusion during rest was not affected. The increase in BOLD response after dehydration was not paralleled by a change in cognitive performance, suggesting an inefficient use of brain metabolic activity following dehydration. This pattern indicates that participants exerted a higher level of neuronal activity in order to achieve the same performance level. Given the limited availability of brain metabolic resources, these findings suggest that prolonged states of reduced water intake may adversely impact executive functions such as planning and visuo-spatial processing.

  7. Effect of Dehydration Conditions on the Chemical, Physical, and Rehydration Properties of Instant Whole Bean (Phaseolus vulgaris L. var. Azufrado

    Directory of Open Access Journals (Sweden)

    Juan Alberto Resendiz Vazquez

    2015-01-01

    Full Text Available The purpose of this study was to evaluate the effect of dehydration conditions on the chemical, physical, and rehydration properties of instant whole beans (Phaseolus vulgaris L. var. Azufrado using a 22 factorial design (air temperature: 25°C and 30°C, air velocity: 0.5 m/s and 1.0 m/s. To determine the kinetic parameters, the rehydration data were fitted to three models: Peleg’s, First Order, and Sigmoid. The protein, fat, and ash contents of the beans were not significantly affected (P>0.05 by the dehydration conditions. Of the 11 physical properties of the instant whole beans, only water activity and splitting were significantly affected by dehydration conditions (P0.05 between the observed and predicted equilibrium moisture contents of the instant whole beans. Regarding the rehydration kinetics for the instant whole beans, the activation energy values ranged from 23.56 kJ/mol to 30.48 kJ/mol, depending on the dehydration conditions. The dehydration conditions had no significant effect (P>0.05 on the rehydration properties of instant whole beans.

  8. An overview of dehydration, aldol-condensation and hydrogenation processes for production of liquid alkanes from biomass-derived carbohydrates

    Energy Technology Data Exchange (ETDEWEB)

    Chheda, Juben N.; Dumesic, James A. [University of Wisconsin-Madison, Department of Chemical and Biological Engineering, Madison, WI 53706 (United States)

    2007-05-30

    We present results for the conversion of carbohydrate feedstocks to liquid alkanes by the combination of dehydration, aldol-condensation/hydrogenation, and dehydration/hydrogenation processing. With respect to the first dehydration step, we demonstrate that HMF can be produced in good selectivity from abundantly available polysaccharides (such as inulin, sucrose) containing fructose monomer units using a biphasic batch reactor system. The reaction system can be optimized to achieve good yields to 5-hydroxymethylfurfural (HMF) from fructose by varying the contents of aqueous-phase modifiers such as dimethylsulfoxide (DMSO) and 1-methyl-2-pyrrolidinone (NMP). Regarding the aldol-condensation/hydrogenation step, we present the development of stable, solid base catalysts in aqueous environments. We address the effects of various reaction parameters such as the molar ratio of reactants and temperature on overall product yield for sequential aldol-condensation and hydrogenation steps. Overall, our results show that it is technically possible to convert carbohydrate feedstocks to produce liquid alkanes by the combination of dehydration, aldol-condensation/hydrogenation, and dehydration/hydrogenation processing; however, further optimization of these processes is required to decrease the overall number of separate steps (and reactors) required in this conversion. (author)

  9. Experiment Study on the Tandem Coalescence and Vacuum Separation Device for Lubricating Oil Dehydration Performance%串联式聚结与真空分离装置用于润滑油脱水的性能试验研究

    Institute of Scientific and Technical Information of China (English)

    张贤明; 高健; 刘先斌

    2016-01-01

    阐述了串联式聚结与真空分离装置的工作原理,采用串联式聚结与真空分离装置,分别试验了 L-TSA46汽轮机油在60℃条件下在聚结分离模式、真空分离模式、串联式聚结与真空组合分离模式下的脱水效率。结果表明:组合分离与聚结分离相比,0~60 min,组合分离脱水效率比聚结分离脱水效率高5%~10%;60 min 后,组合分离脱水效率比聚结分离脱水效率平均高4%左右。组合分离与真空分离相比,在0~100 min,组合分离脱水效率比真空分离脱水效率高6%~40%;在100~140 min,真空分离脱水曲线逐步接近组合分离脱水曲线,两者的脱水效率接近。%The working principle of the vacuum separation is expounded,using tandem coalescence and vacuum separation de-vice,respectively test the L-TSA46 turbine oil dewatering efficiency of separation mode in coalescence separation mode,vacuum separation mode,tandem coalescence combined with vacuum dewatering efficiency of separation mode under the condition of 60℃.The results show that combination separation compared with coalescence separation,0 ~60 min,combination separation de-hydration efficiency than coalescence separation dehydration high efficiency 5% ~10% in 0 ~60 min,After 60 min,combina-tion separation dehydration efficiency higher than coalescence separation dehydration effect on average about 4%.Combination separation compared with vacuum separation,the combinatorial separation dehydration separation efficiency than vacuum dehydra-tion high efficiency 6% ~40% in 0 ~100 min.Vacuum separation dehydration curves gradually close combination separation dehydration curves,both of the dewatering efficiency close.

  10. Water management by dormant insects: comparisons between dehydration resistance during summer aestivation and winter diapause.

    Science.gov (United States)

    Benoit, Joshua B

    2010-01-01

    During summer in temperate regions and tropical dry seasons insects are exposed to extended periods with little available water. To counter this dehydration stress, insects have two options. They can either remain active by utilizing mechanisms to function under severe water stress and high temperatures, or they can escape from the stressful environment by exploiting an aestivation mechanism. During aestivation, insects undergo a variety of molecular and biochemical changes to arrest development, reduce metabolism, tolerate high temperatures, and increase their ability to maintain water balance. In this review, I provide a synopsis of known and possible mechanisms utilized by insects to reduce the stress of dehydration during aestivation. Comparative observations of aestivating and diapausing insects are also discussed to assess similarities and differences in the methods used by insects to increase dehydration resistance between these two types of dormancies. Adaptations that alter moisture requirements during diapause (low metabolic rate, increases in osmolytes, shifts in cuticular hydrocarbons, cell membrane restructing) are likely similar to those utilized at the induction and during the maintenance phase of aestivation. Few studies have been conducted on the physiology, particularly the biochemistry and molecular regulation, of aestivating insects, indicating that much more research is needed to fully assess water balance characteristics of insects during aestivation. Whether an insect is in diapause or aestivation, behavioral, biochemical, and physiological adaptations are essential for suppressing water loss and enhancing survival in a desiccated state.

  11. Antioxidant activity evaluation of new dosage forms as vehicles for dehydrated vegetables.

    Science.gov (United States)

    Romero-de Soto, María Dolores; García-Salas, Patricia; Fernández-Arroyo, Salvador; Segura-Carretero, Antonio; Fernández-Campos, Francisco; Clares-Naveros, Beatriz

    2013-06-01

    A dehydrated vegetables mixture loaded in four pharmaceutical dosage forms as powder, effervescent granulate, sugar granulate and gumdrops were investigated for their antioxidant capacity using 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) radical scavenging capacity assay, oxygen radical absorbance capacity assay and ferric reducing antioxidant potential assay. Total phenolic content of dehydrated vegetables powder mixture was also measured by the Folin-Ciocalteu method, so as to evaluate its contribution to their total antioxidant function. The effect of different temperatures on stability of these systems after 90 days storage was also evaluated. These formulations presented strong antioxidant properties and high phenolic content (279 mg gallic acid equivalent/g of sample) and thus could be potential rich sources of natural antioxidants. Antioxidant properties differed significantly among selected formulations (p dosage forms are new and innovative approach for vegetable intakes in population with special requirements providing an improvement in the administration of vegetables and fruits.

  12. Dehydration of moulding sand in simulated casting process examined with neutron radiography

    Energy Technology Data Exchange (ETDEWEB)

    Schillinger, B., E-mail: Burkhard.Schillinger@frm2.tum.de [Technische Universitaet Muenchen, FRM II and Faculty for Physics E21, Lichtenbergstr. 1, 85748 Garching (Germany); Calzada, E. [Technische Universitaet Muenchen, FRM II and Faculty for Physics E21, Lichtenbergstr. 1, 85748 Garching (Germany); Eulenkamp, C.; Jordan, G.; Schmahl, W.W. [Ludwig-Maximilians-Universitaet Muenchen, Department fuer Geo- und Umweltwissenschaften, Sektion Kristallographie, Theresienstr. 41, 80333 Muenchen (Germany)

    2011-09-21

    Natural bentonites are an important material in the casting industry. Smectites as the main component of bentonites plasticize and stabilise sand moulds. Pore water as well as interlayer water within the smectites are lost as a function of time, location and temperature. Although rehydration of the smectites should be a reversible process, the industrially dehydrated smectites lose their capability to reabsorb water. This limits the number of possible process cycles of the mould material. A full understanding of the dehydration process would help to optimise the amount of fresh material to be added and thus save resources. A simulated metal casting was investigated with neutron radiography at the ANTARES neutron imaging facility of the FRM II reactor of Technische Universitaet Muenchen, Germany.

  13. Effect of zeolite catalyst on sugar dehydration for 5-Hydroxymethylfurfural synthesis

    Science.gov (United States)

    Mostapha, Marhaini; Jahar, Noorhasmiera Abu; Chin, Siew Xian; Jaafar, Sharifah Nabihah Syed; Zakaria, Sarani; Aizat, Wan M.; Azizan, Kamalrul Azlan

    2016-11-01

    The effectiveness in the dehydration of sugars into 5-Hydroxymethylfurfural is related to the catalyst existence. A comprehensive synthesis of 5-Hydroxymethylfurfural from fructose, glucose and sucrose (3.73 mmol) with and without addition zeolite catalyst was performed in this study. The reactions were carried out in water-methanol solvent system for 3 hours reaction time at 180°C temperature. The catalytic results from HPLC showed that the reaction with zeolite increases the yield of 5-Hydroxymethylfurfural with 51.72 %, 34.01% and 50.10% for fructose, glucose and sucrose respectively. The study suggests that zeolites promote the isomerization of glucose into fructose to occur and simultaneously catalyze the dehydration of fructose into 5-Hydroxymethylfurfural. Only slight changes on FT-IR spectra of use zeolite after the reaction was observed. Thus suggest that zeolite was a potential catalyst for catalytic reaction for the conversion of sugar into 5-Hydroxymethylfurfural.

  14. Dehydration of moulding sand in simulated casting process examined with neutron radiography

    Science.gov (United States)

    Schillinger, B.; Calzada, E.; Eulenkamp, C.; Jordan, G.; Schmahl, W. W.

    2011-09-01

    Natural bentonites are an important material in the casting industry. Smectites as the main component of bentonites plasticize and stabilise sand moulds. Pore water as well as interlayer water within the smectites are lost as a function of time, location and temperature. Although rehydration of the smectites should be a reversible process, the industrially dehydrated smectites lose their capability to reabsorb water. This limits the number of possible process cycles of the mould material. A full understanding of the dehydration process would help to optimise the amount of fresh material to be added and thus save resources. A simulated metal casting was investigated with neutron radiography at the ANTARES neutron imaging facility of the FRM II reactor of Technische Universität München, Germany.

  15. Food freezing with simultaneous surface dehydration: approximate prediction of freezing time

    Energy Technology Data Exchange (ETDEWEB)

    Campanone, Laura A.; Salvadori, Viviana O.; Mascheroni, Rodolfo H. [Centro de Investigacion Desarollo en Criotecnologia de Alimentos (CIDCA), Facultad de Ciencias Exactas, La Plata (Argentina); MODIAL, Facultad de Ingenieria, La Plata (Argentina)

    2005-03-01

    Freezing of unpackaged foods induces mass transfer in the form of surface ice sublimation, which in turn modifies heat transfer conditions. At present there are no simplified methods for predicting freezing times when surface dehydration occurs. This paper uses a previously developed model for the simulation of simultaneous heat and mass transfer during food freezing and storage to generate a complete set of predicted freezing times when dehydration occurs. Based on these data a simplified analytical method for the prediction of freezing time during freezing of unpackaged frozen foods was developed. The method accounts for product characteristics (shape, size and composition) and operating conditions (initial and refrigerant temperature, heat transfer coefficient, relative humidity). The prediction equation is very simple and results of its use - simulating usual freezing conditions for different products - shows very good accuracy when tested against the previously cited numerical model and all the available experimental data. (Author)

  16. Development of Ultra Low-Temperature Electronics for the AEgIS Experiment

    CERN Document Server

    Kaltenbacher, Thomas; Kellerbauer, Alban; Doser, Michael; Caspers, Friedhelm

    This thesis presents the development of electronics for operation at cryogenic temperatures, with particular emphasis on the cryogenic electronics required for the Antimatter Experiment: Gravity, Interferometry, Spectroscopy (AEgIS) experiment at the European Organisation for Nuclear Research (CERN). The research is focused on a highly sensitive charged particle detection system for a Penning trap, on cryogenic low-pass filters and on a low-loss DC-contact RF switch. The detection system consists of a high quality factor tuned circuit including a superconducting coil, and a low-noise amplifier. Since the experimental setup of the AEgIS experiment requires it, the developed electronics must reliably operate at 4.2 K (~269C) and in high constant magnetic field of more than 1 Tesla. Therefore, the performance of the cryogenic electronic designs were carefully evaluated at low-temperature/high magnetic field, the result of which have important implications for the AEgIS experiment. Moreover, a new possibility of ...

  17. Thermophysical Property Estimation by Transient Experiments: The Effect of a Biased Initial Temperature Distribution

    Directory of Open Access Journals (Sweden)

    Federico Scarpa

    2015-01-01

    Full Text Available The identification of thermophysical properties of materials in dynamic experiments can be conveniently performed by the inverse solution of the associated heat conduction problem (IHCP. The inverse technique demands the knowledge of the initial temperature distribution within the material. As only a limited number of temperature sensors (or no sensor at all are arranged inside the test specimen, the knowledge of the initial temperature distribution is affected by some uncertainty. This uncertainty, together with other possible sources of bias in the experimental procedure, will propagate in the estimation process and the accuracy of the reconstructed thermophysical property values could deteriorate. In this work the effect on the estimated thermophysical properties due to errors in the initial temperature distribution is investigated along with a practical method to quantify this effect. Furthermore, a technique for compensating this kind of bias is proposed. The method consists in including the initial temperature distribution among the unknown functions to be estimated. In this way the effect of the initial bias is removed and the accuracy of the identified thermophysical property values is highly improved.

  18. USE OF COPPER SULFATE FOR DEHYDRATION OF INDUSTRIAL ALCOHOL

    OpenAIRE

    Reyna Mariñas, Leoncio; Facultad de Química e lng. Química, Universidad Nacional Mayor de San Marcos, Lima Peru; Chuquilín Terán, Carlos; Facultad de Química e lng. Química, Universidad Nacional Mayor de San Marcos, Lima Peru

    2014-01-01

    The objective of the work is to obtain alcohol dehydrated from rectified alcohol industrialist of 96º G.L., using copper sulphate, second composed was selected to make the work by its easy separation and recovery. The time required for the total dehydration of the alcohol was 60 minutes. The purity of the dehydrated alcohol was verified by measurement of its refractive index and by comparison with a pattern MERCK and 100 G.L. to 24ºC. El objetivo del trabajo es mostrar el uso del sulfato d...

  19. Change in hydrogen bonding structures of a hydrogel with dehydration

    Science.gov (United States)

    Naohara, Ryo; Narita, Kentaro; Ikeda-Fukazawa, Tomoko

    2017-02-01

    To investigate the mechanisms of structural changes in polymer network and water during dehydration, X-ray diffraction of poly-N,N-dimethylacrylamide (PDMAA) hydrogels was measured. The variation process in the individual structures of water and PDMAA were analyzed by decomposition of the diffraction patterns to separate the respective contributions. The results show that the short-range structures of PDMAA expand during dehydration, whereas the network structure as a whole shrinks. The average length of the hydrogen bonds between water molecules increases with the process. The present results provide a direct evidence of the structural changes of water and polymer in the hydrogel during dehydration.

  20. Characteristics of a Supersonic Swirling Dehydration System of Natural Gas

    Institute of Scientific and Technical Information of China (English)

    刘恒伟; 刘中良; 冯永训; 顾克宇; 颜廷敏

    2005-01-01

    A new type of dehydration unit for natural gas was briefly described and its basic structure and working principles were presented. An indoor test rig for testing the unit performance was set up and the experimental results were given. The results showed that the unit could attain a maximum dew point depression of about 20~C without any need of external mechanical power and chemicals. The pressure loss ratio, shock wave and the flow rate had great influence on the dehydration characteristics. From the systematic analysis of the factors that affect the dehydration efficiency of the unit, the suggestions for improving the unit are put forward.

  1. Thermoelectric Converter for Loop Heat Pipe Temperature Control: Experience and Lessons Learned

    Science.gov (United States)

    Ku, Jentung; Ottenstein, Laura

    2010-01-01

    This paper describes the theoretical background and implementation methodology of using a thermoelectric converter (TEC) for operating temperature control of a loop heat pipe (LHP). In particular, experimental results from ambient and thermal vacuum tests of an LHP are presented for illustrations. The most commonly used state-of-the-art method to control the LHP operating temperature is to cold bias its compensation chamber (CC) and use an electrical heater to maintain the CC at the desired set point temperature. Although effective, this approach has its shortcomings in that the electrical heater can only provide heating to the CC, and the required power can be large under certain conditions. An alternative method is to use a TEC, which is capable of providing both heating and cooling to the CC. In this method, one side of the TEC is attached to the CC, and the other side is connected to the evaporator via a thermal strap. Using a bipolar power supply and a control algorithm, a TEC can function as a heater or a cooler, depending on the direction of the current flow. Extensive ground tests of several LHPs have demonstrated that a TEC can provide very tight temperature control for the CC. It also offers several additional advantages: (1) The LHP can operate at temperatures below its natural operating temperature at low heat loads; (2) The required heater power for a TEC is much less than that for an electrical heater; and (3) It enhances the LHP start-up success. Although the concept of using a TEC for LHP temperature control is simple, there are many factors to be considered in its implementation for space applications because the TEC is susceptible to the shear stress and yet has to sustain the dynamic load under the spacecraft launch environment. The added features that help the TEC to withstand the dynamic load will inevitably affect the TEC thermal performance. Some experiences and lessons learned are addressed in this paper.

  2. Compression of fractionated sun-cured and dehydrated alfalfa chops into cubes--specific energy models.

    Science.gov (United States)

    Adapa, Phani; Schoenau, Greg; Tabil, Lope; Sokhansanj, Shahab; Singh, Asheesh

    2007-01-01

    The objective of this study was to determine the specific energy requirements for the compression of fractionated sun-cured and dehydrated alfalfa chops, when subjected to different pressures and holding times. The compression behavior of fractionated sun-cured and dehydrated alfalfa chops was studied using a single cubing unit capable of making one cube in a single stroke of the plunger. The cube die dimensions were 30 mm x 30 mm in cross-section and an effective depth of compression of 0.38 m. The initial moisture content of dehydrated and sun-cured chops were 6% and 7% (wb), respectively. A stack of two sieves (instead of five) was used along with a pan to achieve leaf and stem separation. The nominal opening sizes of two sieves with square holes were 3.96 and 1.17 mm, respectively. Leaf and stem fractions were combined later to obtain five different samples each for sun-cured and dehydrated alfalfa with leaf content ranging from 0% to 100% by mass in increments of 25%. The chop moisture content and preheat temperature before compaction was 10% (wb) and 75 degrees C, respectively. The cube die temperature was maintained at 90+/-5 degrees C. The mass of chops used for making each cube was 23+/-02 g. A hydraulic press was used to apply 9.0, 12.0 and 14.0 MPa of pressures through a plunger. After compression, the plunger was held in place for 10 and 30s, before the compacted forage was extracted. Empirical equations were fitted to the data relating specific energy for cube making to pressure, residence time, and leaf content.

  3. Dehydration: cause of fatigue or sign of pacing in elite soccer?

    Science.gov (United States)

    Edwards, Andrew M; Noakes, Timothy D

    2009-01-01

    Numerous studies have suggested that dehydration is a causal factor to fatigue across a range of sports such as soccer; however, empirical evidence is equivocal on this point. It is also possible that exercise-induced moderate dehydration is purely an outcome of significant metabolic activity during a game. The diverse yet sustained physical activities in soccer undoubtedly threaten homeostasis, but research suggests that under most environmental conditions, match-play fluid loss is minimal ( approximately 1-2% loss of body mass), metabolite accumulation remains fairly constant, and core temperatures do not reach levels considered sufficiently critical to require the immediate cessation of exercise. A complex (central) metabolic control system which ensures that no one (peripheral) physiological system is maximally utilized may explain the diversity of research findings concerning the impact of individual factors such as dehydration on elite soccer performance. In consideration of the existing literature, we propose a new interpretative pacing model to explain the self-regulation of elite soccer performance and, in which, players behaviourally modulate efforts according to a subconscious strategy. This strategy is based on both pre-match (intrinsic and extrinsic factors) and dynamic considerations during the game (such as skin temperature, thirst, accumulation of metabolites in the muscles, plasma osmolality and substrate availability), which enables players to avoid total failure of any single peripheral physiological system either prematurely or at the conclusion of a match. In summary, we suggest that dehydration is only an outcome of complex physiological control (operating a pacing plan) and no single metabolic factor is causal of fatigue in elite soccer.

  4. DMSO Induces Dehydration near Lipid Membrane Surfaces

    Science.gov (United States)

    Cheng, Chi-Yuan; Song, Jinsuk; Pas, Jolien; Meijer, Lenny H.H.; Han, Songi

    2015-01-01

    Dimethyl sulfoxide (DMSO) has been broadly used in biology as a cosolvent, a cryoprotectant, and an enhancer of membrane permeability, leading to the general assumption that DMSO-induced structural changes in cell membranes and their hydration water play important functional roles. Although the effects of DMSO on the membrane structure and the headgroup dehydration have been extensively studied, the mechanism by which DMSO invokes its effect on lipid membranes and the direct role of water in this process are unresolved. By directly probing the translational water diffusivity near unconfined lipid vesicle surfaces, the lipid headgroup mobility, and the repeat distances in multilamellar vesicles, we found that DMSO exclusively weakens the surface water network near the lipid membrane at a bulk DMSO mole fraction (XDMSO) of DMSO was found to effectively destabilize the hydration water structure at the lipid membrane surface at XDMSO 0.1, DMSO enters the lipid interface and restricts the lipid headgroup motion. We postulate that DMSO acts as an efficient cryoprotectant even at low concentrations by exclusively disrupting the water network near the lipid membrane surface, weakening the cohesion between water and adhesion of water to the lipid headgroups, and so mitigating the stress induced by the volume change of water during freeze-thaw. PMID:26200868

  5. Elemental and Isotopic Incorporation into the Aragonitic Shells of Arctica Islandica: Insights from Temperature Controlled Experiments

    Science.gov (United States)

    Wanamaker, A. D.; Gillikin, D. P.

    2014-12-01

    The long-lived ocean quahog, Arctica islandica, is a fairly well developed and tested marine proxy archive, however, the utility of elemental ratios in A. islandica shell material as environmental proxies remains questionable. To further evaluate the influence of seawater temperature on elemental and isotopic incorporation during biomineralization, A. islandica shells were grown at constant temperatures under two regimes during a 16-week period from March 27 to July 21, 2011. Seawater from the Darling Marine Center in Walpole, Maine was pumped into temperature and flow controlled tanks that were exposed to ambient food and salinity conditions. A total of 20 individual juvenile clams with an average shell height of 36 mm were stained with calcein (a commonly used biomarker) and cultured at 10.3 ± 0.3 °C for six weeks. After this, shell heights were measured and the clams were again stained with calcein and cultured at 15.0 ± 0.4 °C for an additional 9.5 weeks. The average shell growth during the first phase of the experiment was 2.4 mm with a linear extension rate of 0.40 mm/week. The average shell growth during the second phase of the experiment was 3.2 mm with an extension rate of 0.34 mm/week. Average salinity values were 30.2 ± 0.7 and 30.7 ±0.7 in the first and second phases of the experiment, respectively. Oxygen isotopes from the cultured seawater were collected throughout the experiment and provide the basis for establishing if shells grew in oxygen isotopic equilibrium. Elemental ratios (primarily Ba/Ca, Mg/Ca, Sr/Ca) in the aragonitic shells were determined via laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), while stable oxygen and carbon isotope ratios were measured using continuous flow isotope ratio mass spectrometry. Continuous sampling within and across the temperature conditions (from 10 °C to 15 °C) coupled with the calcein markings provides the ability to place each sample into a precise temporal framework. The

  6. Water Transport in MgSO4·7H2O during Dehydration in View of Thermal Storage

    NARCIS (Netherlands)

    Donkers, P.A.J.; Beckert, S.; Pel, L.; Stallmach, F.; Steiger, M.; Adan, O.C.G.

    2015-01-01

    The water phases in a MgSO4·7H2O crystal during heating were studied with the help of NMR. The thermogravimetric analysis (TGA) data showed that the heating rate has a strong effect on the dehydration process. NMR experiments showed that pore water, i.e., an aqueous solution of MgSO4, was produced d

  7. Effects of dehydration on performance in man: Annotated bibliography

    Science.gov (United States)

    Greenleaf, J. E.

    1973-01-01

    A compilation of studies on the effect of dehydration on human performance and related physiological mechanisms. The annotations are listed in alphabetical order by first author and cover material through June 1973.

  8. Voluntary dehydration and cognitive performance in trained college athletes.

    Science.gov (United States)

    D'anci, Kristen E; Vibhakar, Arjun; Kanter, Jordan H; Mahoney, Caroline R; Taylor, Holly A

    2009-08-01

    Cognitive and mood decrements resulting from mild dehydration and glucose consumption were studied. Men and women (total N = 54; M age = 19.8 yr., SD = 1.2) were recruited from college athletic teams. Euhydration or dehydration was achieved by athletes completing team practices with or without water replacement. Dehydration was associated with higher thirst and negative mood ratings as well as better Digit Span performance. Participants showed better Vigilance Attention with euhydration. Hydration status and athlete's sex interacted with performance on Choice Reaction Time and Vigilance Attention. In a second study, half of the athletes received glucose prior to cognitive testing. Results for negative mood and thirst ratings were similar, but for cognitive performance the results were mixed. Effects of glucose on cognition were independent of dehydration.

  9. Pervaporation : membranes and models for the dehydration of ethanol

    NARCIS (Netherlands)

    Spitzen, Johannes Wilhelmus Franciscus

    1988-01-01

    In this thesis the dehydration of ethanol/water mixtures by pervaporation using homogeneous membranes is studied. Both the general transport mechanism as well as the development of highly selective membranes for ethanol/water separation are investigated.

  10. The global surface temperatures of the Moon as measured by the Diviner Lunar Radiometer Experiment

    Science.gov (United States)

    Williams, J.-P.; Paige, D. A.; Greenhagen, B. T.; Sefton-Nash, E.

    2017-02-01

    The Diviner Lunar Radiometer Experiment onboard the Lunar Reconnaissance Orbiter (LRO) has been acquiring solar reflectance and mid-infrared radiance measurements nearly continuously since July of 2009. Diviner is providing the most comprehensive view of how regoliths on airless bodies store and exchange thermal energy with the space environment. Approximately a quarter trillion calibrated radiance measurements of the Moon, acquired over 5.5 years by Diviner, have been compiled into a 0.5° resolution global dataset with a 0.25 h local time resolution. Maps generated with this dataset provide a global perspective of the surface energy balance of the Moon and reveal the complex and extreme nature of the lunar surface thermal environment. Our achievable map resolution, both spatially and temporally, will continue to improve with further data acquisition. Daytime maximum temperatures are sensitive to the albedo of the surface and are ∼387-397 K at the equator, dropping to ∼95 K just before sunrise, though anomalously warm areas characterized by high rock abundances can be > 50 K warmer than the zonal average nighttime temperatures. An asymmetry is observed between the morning and afternoon temperatures due to the thermal inertia of the lunar regolith with the dusk terminator ∼30 K warmer than the dawn terminator at the equator. An increase in albedo with incidence angle is required to explain the observed decrease in temperatures with latitude. At incidence angles exceeding ∼40°, topography and surface roughness influence temperatures resulting in increasing scatter in temperatures and anisothermality between Diviner channels. Nighttime temperatures are sensitive to the thermophysical properties of the regolith. High thermal inertia (TI) materials such as large rocks, remain warmer during the long lunar night and result in anomalously warm nighttime temperatures and anisothermality in the Diviner channels. Anomalous maximum and minimum temperatures are

  11. Development of a design methodology for high temperature cyclic applications of materials which experience cyclic softening

    Energy Technology Data Exchange (ETDEWEB)

    Marriott, D.L.; Stubbins, J.F. (Illinois Univ., Urbana, IL (USA). Dept. of Mechanical and Industrial Engineering)

    1988-12-01

    The project has as its original focus the high temperature behavior of 2.25 Cr-1 Mo steel, heat treated to produce a predominantly bainitic microstructure and the load carrying response of components made of this material. Experiments were carried out on uniform and notched specimens under both steady and cyclic loading using specially acquired electromechanical test machines. It emerged that a very important feature of mechanical behavior under the conditions of interest was the strong tendency of this material to cyclically soften, particularly at high temperature in the creep range, giving the illusion of a severe creep-fatigue interaction under certain conditions. This finding led to a significant component of the project being devoted to investigation of the effects of local, as opposed to generalized, cyclic softening, and the implications this phenomenon might have on the setting of allowable design stress limits. The format of this report is as follows: The second chapter is a review of the work carried out in approximately chronological order under the headings of work was carried out under the following: (1) 2.25 Cr 1 Mo Steel -- Elevated Temperature Fatigue and Environmental Effects; (2) Preliminary Studies of Advanced Austenitics; (3) A Uniaxial Constitutive Model for Cyclic Softening; (4) The Iso-Cyclic Stress-Strain Approach to Evaluation of Components in Cyclic Softening Materials; (5) Testing of High Temperature Austenitic Alloys; and (6) Design Methodology for Aging Materials -- Application to Cyclic Softening. 65 refs., 39 figs., 7 tabs.

  12. Characterizing the kinetics of volume recovery in glasses by instantaneous temperature-jump experiments

    Energy Technology Data Exchange (ETDEWEB)

    Lagasse, R.R. (Sandia National Labs., Albuquerque, NM); Cohen, R.E.; Letton, A.

    1982-03-01

    This article proposes a temperature-jump (T-jump) approach for characterizing the kinetics of volume recovery in glassy materials. The kinetic characterization is based on the Kovacs-Aklonis model. This incorporates a retardation-time spectrum which shifts according to both the temperature and the instantaneous volume. The proposed experiments involve measuring the change in recovery rate caused by an abrupt temperature jump. Although an analogous procedure has been used to determine the activation energy for linear viscoelastic creep, the analysis for volume recovery is complicated by its inherent nonlinearity. Nevertheless, accounting for the nonlinearity by a reduction of the time scale permits the T-jump results to be analyzed. In particular, the T-jump approach can be used to: (i) test a particular functional form for the shift factor; and (ii) determine the previously unmeasurable parameter x, which defines the relative importance of the temperature dependence and the volume dependence in this function. In addition, numerical simulations indicate that the proposed method can be implemented in the laboratory. 7 figures.

  13. Phenylnaphthalene as a Heat Transfer Fluid for Concentrating Solar Power: High-Temperature Static Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Bell, Jason R [ORNL; Joseph III, Robert Anthony [ORNL; McFarlane, Joanna [ORNL; Qualls, A L [ORNL

    2012-05-01

    Concentrating solar power (CSP) may be an alternative to generating electricity from fossil fuels; however, greater thermodynamic efficiency is needed to improve the economics of CSP operation. One way of achieving improved efficiency is to operate the CSP loop at higher temperatures than the current maximum of about 400 C. ORNL has been investigating a synthetic polyaromatic oil for use in a trough type CSP collector, to temperatures up to 500 C. The oil was chosen because of its thermal stability and calculated low vapor and critical pressures. The oil has been synthesized using a Suzuki coupling mechanism and has been tested in static heating experiments. Analysis has been conducted on the oil after heating and suggests that there may be some isomerization taking place at 450 C, but the fluid appears to remain stable above that temperature. Tests were conducted over one week and further tests are planned to investigate stabilities after heating for months and in flow configurations. Thermochemical data and thermophysical predictions indicate that substituted polyaromatic hydrocarbons may be useful for applications that run at higher temperatures than possible with commercial fluids such as Therminol-VP1.

  14. The role of hydrogen bonding in the thermal expansion and dehydration of brushite, di-calcium phosphate dihydrate

    Science.gov (United States)

    Schofield, P. F.; Knight, K. S.; Houwen, J. A. M. Van Der; Valsami-Jones, E.

    2004-12-01

    The unit-cell and atomic parameters of perdeuterated brushite have been extracted from Rietveld analysis of neutron powder diffraction data within the temperature range 4.2 to 470 K. The thermal expansion of brushite is anisotropic, with the largest expansion along the b axis due principally to the effect of the O(1)···D(4) and O(3)···D(2) hydrogen bonds. Expansion along the c axis, influenced by the Ow1···D(5) interwater hydrogen bond, is also large. The high temperature limits for the expansion coefficients for the unit-cell edges a, b and c are 9.7(5) × 10-6, 3.82(9) × 10-5 and 5.54(5) × 10-5 K-1, respectively, and for the cell volume it is 9.7(1) × 10-5 K-1. The β angle displays oscillatory variation, and empirical data analysis results in αβ = 1.28(3) × 10-6sin(0.0105 T) K-1, within this temperature range. The evolution of the thermal expansion tensor of brushite has been calculated between 50 ≤T≤ 400 K. At 300 K the magnitudes of the principal axes are α11 = 50(6) × 10-6 K-1, α22 = 26.7(7) × 10-6 K-1 and α33 = 7.0(5) × 10-6 K-1. The intermediate axis, α22, is parallel to b, and using IRE convention for the tensor orthonormal basis, the axes α11 and α33 have directions equal to (-0.228, 0, -0.974) and (-0.974, 0, 0.228) respectively. Under the conditions of these experiments, the onset of dehydration occurred at temperatures above 400 K. Bond valence analysis combined with assessments of the thermal evolution of the bonding within brushite suggests that dehydration is precipitated through instabilities in the chemical environment of the second water molecule.

  15. Active dehydration impairs upper and lower body anaerobic muscular power.

    Science.gov (United States)

    Jones, Leon C; Cleary, Michelle A; Lopez, Rebecca M; Zuri, Ron E; Lopez, Richard

    2008-03-01

    We examined the effects of active dehydration by exercise in a hot, humid environment on anaerobic muscular power using a test-retest (euhydrated and dehydrated) design. Seven subjects (age, 27.1 +/- 4.6 years; mass, 86.4 +/- 9.5 kg) performed upper and lower body Wingate anaerobic tests prior to and after a 1.5-hour recovery from a heat stress trial of treadmill exercise in a hot, humid environment (33.1 +/- 3.1C = 55.1 +/- 8.9% relative humidity) until a 3.1 +/- 0.3% body mass loss was achieved. Dehydration was confirmed by a significant body mass loss (P dehydrated compared to the euhydrated condition. Compared to the euhydrated condition, the dehydrated condition mean power was significantly (P = 0.014) decreased 7.17% in the upper body and 19.20% in the lower body. Compared to the euhydrated condition, the dehydrated condition peak power was significantly (P = 0.013) decreased 14.48% in the upper body and 18.36% in the lower body. No significant differences between the euhydrated and dehydrated conditions were found for decrease in power output (P = 0.219, power = 0.213). Our findings suggest that dehydration of 2.9% body mass decreases the ability to generate upper and lower body anaerobic power. Coaches and athletes must understand that sports performance requiring anaerobic strength and power can be impaired by inadequate hydration and may contribute to increased susceptibility to musculoskeletal injury.

  16. Cryopreservation of coffee zygotic embryos: dehydration and osmotic rehydration

    Directory of Open Access Journals (Sweden)

    Maísa de Siqueira Pinto

    Full Text Available ABSTRACT Conservation of plant genetic resources is important to prevent genetic erosion. Seed banks are the most common method of ex situ conservation; however, coffee seeds can not be stored by conventional methods. Cryopreservation is a viable alternative for long-term conservation of species that produce intermediate or recalcitrant seeds, as coffee. The aim of this work was to cryopreserve Coffea arabica L. cv Catuaí Vermelho IAC 144 zygotic embryos, and analyse the effects of dehydration prior cryopreservation and osmotic rehydration after thawing, in embryos germination and seedlings formation after cryopreservation. Prior to cryopreservation, different dehydration times (0, 15, 30, 60 and 120 min were tested. Dehydrated embryos were cryopreserved in liquid nitrogen for 1 hour, and after thawing were rehydrated by osmotic solutions. Dehydrated and non-cryopreserved embryos were also analysed. The test with 2,3,5 triphenyl tetrazolium chloride (TTC was used to evaluate the embryos viability. Non-dehydrated embryos did not survive after freezing. Embryos that were dehydrated until 20% of the moisture content did not germinate when osmotic rehydration was not performed. In contrast, cryopreserved embryos with the same moisture content presented 98% germination when they were rehydrated slowly in osmotic solution. According to tetrazolium tests, embryos presented maximum viability (75% after dehydration for 60 minutes (23% moisture content. Therefore, coffee zygotic embryos (Coffea arabica L. cv. Catuaí Vermelho can be successfully cryopreserved using physical dehydration in silica gel for 60 minutes (23% moisture content, followed by osmotic rehydration after thawing. This method allowed a germination of 98% of cryopreserved zygotic embryos.

  17. Additional experiments on flowability improvements of aviation fuels at low temperatures, volume 2

    Science.gov (United States)

    Stockemer, F. J.; Deane, R. L.

    1982-01-01

    An investigation was performed to study flow improver additives and scale-model fuel heating systems for use with aviation hydrocarbon fuel at low temperatures. Test were performed in a facility that simulated the heat transfer and temperature profiles anticipated in wing fuel tanks during flight of long-range commercial aircraft. The results are presented of experiments conducted in a test tank simulating a section of an outer wing integral fuel tank approximately full-scale in height, chilled through heat exchange panels bonded to the upper and lower horizontal surfaces. A separate system heated lubricating oil externally by a controllable electric heater, to transfer heat to fuel pumped from the test tank through an oil-to-fuel heat exchanger, and to recirculate the heated fuel back to the test tank.

  18. Temperature data assimilation for hyporheic exchange: numerical studies and sandbox experiments

    Science.gov (United States)

    Ju, L.; Zeng, L.; Wu, L.

    2015-12-01

    Due to the temperature difference between groundwater and surface water (GW-SW), heat can be used as an ideal tracer in hyporheic zone. To quantify GW-SW interactions, existing methods are mainly based on the analytical solution of one-dimensional heat transport equation. However, the assumptions therein are usually violated in practical applications. Furthermore, there are relatively limited experimental sandbox studies regarding heat tracer for complicated GW-SW interactions. In this study, we developed a data assimilation method to quantify the GW-SW interaction in the presence of heterogeneous river bed. A numerical simulator was used to solve the groundwater and heat transport equation. Then the ensemble Kalman filter (EnKF) was employed to assimilate the temperature data to quantify the unknown interactions (velocity field) between GW-SW and heterogeneous hydraulic conductivity field. The validity of this method was verified by both numerical simulation and sandbox experiment for different scenarios.

  19. Observing System Simulation Experiments for the assessment of temperature sampling strategies in the Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    F. Raicich

    Full Text Available For the first time in the Mediterranean Sea various temperature sampling strategies are studied and compared to each other by means of the Observing System Simulation Experiment technique. Their usefulness in the framework of the Mediterranean Forecasting System (MFS is assessed by quantifying their impact in a Mediterranean General Circulation Model in numerical twin experiments via univariate data assimilation of temperature profiles in summer and winter conditions. Data assimilation is performed by means of the optimal interpolation algorithm implemented in the SOFA (System for Ocean Forecasting and Analysis code. The sampling strategies studied here include various combinations of eXpendable BathyThermograph (XBT profiles collected along Volunteer Observing Ship (VOS tracks, Airborne XBTs (AXBTs and sea surface temperatures. The actual sampling strategy adopted in the MFS Pilot Project during the Targeted Operational Period (TOP, winter-spring 2000 is also studied.

    The data impact is quantified by the error reduction relative to the free run. The most effective sampling strategies determine 25–40% error reduction, depending on the season, the geographic area and the depth range. A qualitative relationship can be recognized in terms of the spread of information from the data positions, between basin circulation features and spatial patterns of the error reduction fields, as a function of different spatial and seasonal characteristics of the dynamics. The largest error reductions are observed when samplings are characterized by extensive spatial coverages, as in the cases of AXBTs and the combination of XBTs and surface temperatures. The sampling strategy adopted during the TOP is characterized by little impact, as a consequence of a sampling frequency that is too low.

    Key words. Oceanography: general (marginal and semi-enclosed seas; numerical modelling

  20. The instantaneous rate dependence in low temperature laboratory rock friction and rock deformation experiments

    Science.gov (United States)

    Beeler, N.M.; Tullis, T.E.; Kronenberg, A.K.; Reinen, L.A.

    2007-01-01

    Earthquake occurrence probabilities that account for stress transfer and time-dependent failure depend on the product of the effective normal stress and a lab-derived dimensionless coefficient a. This coefficient describes the instantaneous dependence of fault strength on deformation rate, and determines the duration of precursory slip. Although an instantaneous rate dependence is observed for fracture, friction, crack growth, and low temperature plasticity in laboratory experiments, the physical origin of this effect during earthquake faulting is obscure. We examine this rate dependence in laboratory experiments on different rock types using a normalization scheme modified from one proposed by Tullis and Weeks [1987]. We compare the instantaneous rate dependence in rock friction with rate dependence measurements from higher temperature dislocation glide experiments. The same normalization scheme is used to compare rate dependence in friction to rock fracture and to low-temperature crack growth tests. For particular weak phyllosilicate minerals, the instantaneous friction rate dependence is consistent with dislocation glide. In intact rock failure tests, for each rock type considered, the instantaneous rate dependence is the same size as for friction, suggesting a common physical origin. During subcritical crack growth in strong quartzofeldspathic and carbonate rock where glide is not possible, the instantaneous rate dependence measured during failure or creep tests at high stress has long been thought to be due to crack growth; however, direct comparison between crack growth and friction tests shows poor agreement. The crack growth rate dependence appears to be higher than the rate dependence of friction and fracture by a factor of two to three for all rock types considered. Copyright 2007 by the American Geophysical Union.

  1. Traditional Male Circumcision: Ways to Prevent Deaths Due to Dehydration.

    Science.gov (United States)

    Douglas, Mbuyiselo; Maluleke, Thelmah Xavela

    2016-02-01

    Deaths of initiates occurring in the circumcision initiation schools are preventable. Current studies list dehydration as one of the underlying causes of deaths among traditional male circumcision initiates in the Eastern Cape, a province in South Africa, but ways to prevent dehydration in the initiation schools have not been adequately explored. The goals of this study were to (a) explore the underlying determinants of dehydration among initiates aged from 12 to 18 years in the traditional male circumcision initiation schools and (b) determine knowledge of participants on the actions to be taken to prevent dehydration. The study was conducted at Libode, a rural area falling under Nyandeni municipality. A simple random sampling was used to select three focus group discussions with 36 circumcised boys. A purposive sampling was used to select 10 key informants who were matured and experienced people with knowledge of traditional practices and responsible positions in the communities. The research findings indicate that the practice has been neglected to inexperienced, unskillful, and abusive traditional attendants. The overall themes collated included traditional reasons for water restriction, imbalanced food nutrients given to initiates, poor environmental conditions in the initiation hut, and actions that should be taken to prevent dehydration. This article concludes with discussion and recommendation of ways to prevent dehydration of initiates in the form of a comprehensive circumcision health promotion program.

  2. Whole transcriptome organisation in the dehydrated supraoptic nucleus

    Directory of Open Access Journals (Sweden)

    C.C.T. Hindmarch

    2013-12-01

    Full Text Available The supraoptic nucleus (SON is part of the central osmotic circuitry that synthesises the hormone vasopressin (Avp and transports it to terminals in the posterior lobe of the pituitary. Following osmotic stress such as dehydration, this tissue undergoes morphological, electrical and transcriptional changes to facilitate the appropriate regulation and release of Avp into the circulation where it conserves water at the level of the kidney. Here, the organisation of the whole transcriptome following dehydration is modelled to fit Zipf's law, a natural power law that holds true for all natural languages, that states if the frequency of word usage is plotted against its rank, then the log linear regression of this is -1. We have applied this model to our previously published euhydrated and dehydrated SON data to observe this trend and how it changes following dehydration. In accordance with other studies, our whole transcriptome data fit well with this model in the euhydrated SON microarrays, but interestingly, fit better in the dehydrated arrays. This trend was observed in a subset of differentially regulated genes and also following network reconstruction using a third-party database that mines public data. We make use of language as a metaphor that helps us philosophise about the role of the whole transcriptome in providing a suitable environment for the delivery of Avp following a survival threat like dehydration.

  3. THE FUNCTIONAL ARCHITECTURE OF DEHYDRATION-ANOREXIA

    Science.gov (United States)

    Watts, Alan G.; Boyle, Christina N.

    2010-01-01

    The anorexia that accompanies the drinking of hypertonic saline (DE-anorexia) is a critical adaptive behavioral mechanism that helps protect the integrity of fluid compartments during extended periods of cellular dehydration. Feeding is rapidly reinstated once drinking water is made available again. The relative simplicity and reproducibility of these behaviors makes DE-anorexia a very useful model for investigating how the various neural networks that control ingestive behaviors first suppress and then reinstate feeding. We show that DE-anorexia develops primarily because the mechanisms that terminate ongoing meals are upregulated in such a way as to significantly reduce meal size. At the same time however, signals generated by the ensuing negative energy balance appropriately activate neural mechanisms that can increase food intake. But as the output from these two competing processes is integrated, the net result is an increasing reduction of nocturnal food intake, despite the fact that spontaneous meals are initiated with the same frequency as in control animals. Furthermore, hypothalamic NPY injections also stimulate feeding in DE-anorexic animals with the same latency as controls, but again meals are prematurely terminated. Comparing Fos expression patterns across the brain following 2-deoxyglucose administration to control and DE-anorexic animals implicates neurons in the descending part of the parvicellular paraventricular nucleus of the hypothalamus and the lateral hypothalamic areas as key components of the networks that control DE-anorexia. Finally, DE-anorexia generates multiple inhibitory processes to suppress feeding. These are differentially disengaged once drinking water is reinstated. PMID:20399797

  4. Individual room temperature regulation - Taking stock after 16 years experience; ERR - Bilanz nach 16 Jahren Erfahrung

    Energy Technology Data Exchange (ETDEWEB)

    Scalbert, J.-P.; Dyla, B.

    2007-07-01

    This article takes a look at experience gained with individual room temperature control in ten schoolhouses in Basel, Switzerland. The systems were introduced as part of a comprehensive energy-saving scheme in Basel. The first installation was made in 1991. The article discusses experience gained in general in buildings with various usage. Topics discussed include the effects of varying occupation times, user behaviour and the control technologies used. Various data-collection and control system using data-bus and power line communication are examined. The susceptibility of the control systems to vandalism is also looked at. Energy savings made are discussed. Economic viability is reviewed and figures are presented for the ten schoolhouses in tabular form. Finally future actions to be taken is reviewed and recommendations for further buildings are made.

  5. Dehydration of Carbohydrates to 5-Hydroxymethylfurfural in Ionic Liquids Catalyzed by Hexachlorotriphosphazene

    Institute of Scientific and Technical Information of China (English)

    宋金良; 张斌斌; 史敬华; 马珺; 杨冠英; 韩布兴

    2012-01-01

    Development of efficient catalysts for the dehydration of carbohydrates to produce 5-hydroxymethylfurfural (HMF) is a very attractive topic. In this work, dehydration of fructose catalyzed by three organic molecules, includ- ing hexachlorotriphosphazene (N3P3CI6), trichloromelamine (C3N6H3CI3) and N-bromosuccinimide (NBS), was studied in ionic liquids. It was discovered that the three organic molecules had high activity in accelerating the de- hydration of fructose and N3P3C16 was the most efficient catalyst among them. The effects of amount of catalysts, temperature, solvents, reaction time, and substrate/solvent weight ratio on the reaction were investigated using N3P3C16 as the catalyst and 1-butyl-3-methylimidazolium chloride ([Bmim]C1) as the solvent. It was demonstrated that the N3P3C16/[Bmim]CI catalytic system was very effective for catalyzing the reaction. The yield of HMF could reach 92.8% in 20 rain at the optimized conditions and the N3P3C16/[Bmim]C1 system could be reused. Further study indicated that the N3P3C16/[Bmim]CI system was also effective for the dehydration of sucrose and inulin and satisfactory yield could be obtained at suitable conditions.

  6. From molecular dehydration to excess volumes of phase-separating PNIPAM solutions.

    Science.gov (United States)

    Philipp, Martine; Kyriakos, Konstantinos; Silvi, Luca; Lohstroh, Wiebke; Petry, Winfried; Krüger, Jan K; Papadakis, Christine M; Müller-Buschbaum, Peter

    2014-04-17

    For aqueous poly(N-isopropyl acrylamide) (PNIPAM) solutions, a structural instability leads to the collapse and aggregation of the macromolecules at the temperature-induced demixing transition. The accompanying cooperative dehydration of the PNIPAM chains is known to play a crucial role in this phase separation. We elucidate the impact of partial dehydration of PNIPAM on the volume changes related to the phase separation of dilute to concentrated PNIPAM solutions. Quasi-elastic neutron scattering enables us to directly follow the isotropic jump diffusion behavior of the hydration water and the almost freely diffusing water. As the hydration number decreases from 8 to 2 for the demixing 25 mass % PNIPAM solution, only a partial dehydration of the PNIPAM chains occurs. Dilatation studies reveal that the transition-induced volume changes depend in a remarkable manner on the PNIPAM concentration of the solutions. The excess volume per mole of H2O molecules expelled from the solvation layers of PNIPAM during phase separation probably strongly increases from dilute to concentrated PNIPAM solutions. This finding is qualitatively related to the immense strain-softening previously observed for demixing PNIPAM solutions.

  7. Fabrication of graphene oxide composite membranes and their application for pervaporation dehydration of butanol

    Institute of Scientific and Technical Information of China (English)

    Xianfu Chen; Gongping Liu; Hanyu Zhang; Yiqun Fan

    2015-01-01

    As a new kind of 2D nanomaterials, graphene oxide (GO) with 2–4 layers was fabricated via a modified Hummers method and used for the preparation of pervaporation (PV) membranes. Such GO membranes were prepared via a facile vacuum-assisted method on anodic aluminium oxide disks and applied for the dehydration of butanol. To obtain GO membranes with high performance, effects of pre-treatments, including high-speed centrifugal treat-ment of GO dispersion and thermal treatment of GO membranes, were investigated. In addition, effects of oper-ation conditions on the performance of GO membranes in the PV process and the stability of GO membranes were also studied. It is of benefit to improve the selectivity of GO membrane by pre-treatment that centrifuges the GO dispersion with 10000 r·min−1 for 40 min, which could purify the GO dispersion by removing the large size GO sheets. As prepared GO membrane showed high separation performance for the butanol/water system. The separation factor was 230, and the permeability was as high as 3.1 kg·m−2·h−1 when the PV temperature was 50 °C and the water content in feed was 10%(by mass). Meanwhile, the membrane still showed good stabil-ity for the dehydration of butanol after running for 1800 min in the PV process. GO membranes are suitable candidates for butanol dehydration via PV process.

  8. Designing, constructing and evaluating a dynamic prototype dryer for obtaining rolled dehydrated fruit pulp

    Directory of Open Access Journals (Sweden)

    Pedro Vanegas Mahecha

    2011-01-01

    Full Text Available  This paper describes how a functional prototype for a dynamic dryer was designed, along with its basic parts: drying tunnel, mechanical transport system for material inside the equipment and selecting and designing a system for supplying hot air. A simple transport mechanism was implemented which allowed combining two flow dispositions: parallel and countercurrent flow. Mango (Mangifera indica L pulp was dehydrated using three dryer air temperatures (50°C, 60°C and 70°C and three drying air speeds inside the dryer (1.6, 2.2, 3.4 m s-1 for evaluating the prototype. Propane gas was used as fuel for heating the air. The prototype design led to dehydrating fruit pulp having 4.26 bs smooth initial humidity content up to a 0.11 db final humidity content, with 8-hour drying time (70°C and 3.4 m s-1 air speed, assuming 4.5 0.5 mm pulp thickness, in 300 x 180 mm and 15 mm height rectangular trays. 1.5 0.5 mm thickness rolled dehydrated pulps were obtained in these conditions  The final product had 0.60a (aw water activity providing for a stable product, having low water content and very similar characteristics to those of the fresh product (shown by Weende analysis. 

  9. Enhancement of mass transfer by ultrasound: Application to adsorbent regeneration and food drying/dehydration.

    Science.gov (United States)

    Yao, Ye

    2016-07-01

    The physical mechanisms of heat and mass transfer enhancement by ultrasound have been identified by people. Basically, the effect of 'cavitation' induced by ultrasound is the main reason for the enhancement of heat and mass transfer in a liquid environment, and the acoustic streaming and vibration are the main reasons for that in a gaseous environment. The adsorbent regeneration and food drying/dehydration are typical heat and mass transfer process, and the intensification of the two processes by ultrasound is of complete feasibility. This paper makes an overview on recent studies regarding applications of power ultrasound to adsorbent regeneration and food drying/dehydration. The concerned adsorbents include desiccant materials (typically like silica gel) for air dehumidification and other ones (typically active carbon and polymeric resin) for water treatment. The applications of ultrasound in the regeneration of these adsorbents have been proved to be energy saving. The concerned foods are mostly fruits and vegetables. Although the ultrasonic treatment may cause food degradation or nutrient loss, it can greatly reduce the food processing time and decrease drying temperature. From the literature, it can be seen that the ultrasonic conditions (i.e., acoustic frequency and power levels) are always focused on during the study of ultrasonic applications. The increasing number of relevant studies argues that ultrasound is a very promising technology applied to the adsorbent regeneration and food drying/dehydration.

  10. Influence of dehydration on the electrical conductivity of epidote and implications for high-conductivity anomalies in subduction zones

    Science.gov (United States)

    Hu, Haiying; Dai, Lidong; Li, Heping; Hui, Keshi; Sun, Wenqing

    2017-04-01

    The anomalously high electrical conductivities ( 0.1 to 1 S/m) in deep mantle wedge regions extensively detected by magnetotelluric studies are often associated with the presence of fluids released from the progressive dehydration of subducting slabs. Epidote minerals are the Ca-Al-rich hydrous silicates with huge stability fields exceeding those of amphibole (>70-80 km) in subducting oceanic crust, and they may therefore be transported to greater depth than amphibole and release water to the mantle wedge. In this study, the electrical conductivities of epidote were measured at 0.5-1.5 GPa and 573-1273 K by using a Solartron-1260 Impedance/Gain-Phase Analyzer in a YJ-3000t multianvil pressure within the frequency range of 0.1-106 Hz. The results demonstrate that the influence of pressure on electrical conductivity of epidote is relatively small compared to that of temperature. The dehydration reaction of epidote is observed through the variation of electrical conductivity around 1073 K, and electrical conductivity reaches up to 1 S/m at 1273 K, which can be attributed to aqueous fluid released from epidote dehydration. After sample dehydration, electrical conductivity noticeably decreases by as much as nearly a log unit compared with that before dehydration, presumably due to a combination of the presence of coexisting mineral phases and aqueous fluid derived from the residual epidote. Taking into account the petrological and geothermal structures of subduction zones, it is suggested that the aqueous fluid produced by epidote dehydration could be responsible for the anomalously high conductivities in deep mantle wedges at depths of 70-120 km, particularly in hot subduction zones.

  11. High temperature experiments on a 4 tons UF6 container TENERIFE program

    Energy Technology Data Exchange (ETDEWEB)

    Casselman, C.; Duret, B.; Seiler, J.M.; Ringot, C.; Warniez, P.

    1991-12-31

    The paper presents an experimental program (called TENERIFE) whose aim is to investigate the behaviour of a cylinder containing UF{sub 6} when exposed to a high temperature fire for model validation. Taking into account the experiments performed in the past, the modelization needs further information in order to be able to predict the behaviour of a real size cylinder when engulfed in a 800{degrees}C fire, as specified in the regulation. The main unknowns are related to (1) the UF{sub 6} behaviour beyond the critical point, (2) the relationship between temperature field and internal pressure and (3) the equivalent conductivity of the solid UF{sub 6}. In order to investigate these phenomena in a representative way it is foreseen to perform experiments with a cylinder of real diameter, but reduced length, containing 4 tons of UF{sub 6}. This cylinder will be placed in an electrically heated furnace. A confinement vessel prevents any dispersion of UF{sub 6}. The heat flux delivered by the furnace will be calibrated by specific tests. The cylinder will be changed for each test.

  12. The Titan Haze Simulation experiment on COSmIC: Probing Titan's atmospheric chemistry at low temperature

    Science.gov (United States)

    Sciamma-O'Brien, Ella; Ricketts, Claire L.; Salama, Farid

    2014-11-01

    The aim of the Titan Haze Simulation (THS) experiment is to contribute to a better understanding of aerosol formation in Titan's atmosphere through the study of the chemical formation pathways that link the simpler gas phase molecules resulting from the first steps of the N2-CH4 chemistry, to the more complex gas phase precursors of aerosols; and more specifically, to investigate the role of polycyclic aromatic hydrocarbons (PAHs) and nitrogenated polycyclic aromatic hydrocarbons (PANHs), among other hydrocarbons, in this process. In the THS experiment developed at the NASA Ames Cosmic simulation facility (COSmIC), Titan's atmospheric chemistry is simulated by a pulsed plasma jet expansion at temperature conditions (∼150 K) close to those found in Titan's atmosphere in regions where aerosols are formed. In addition, because of the very short residence time of the gas in the plasma discharge, only the initial steps of the chemistry occur, making the COSmIC/THS a unique tool to study the first and intermediate (when adding heavier precursors to the initial N2-CH4 mixture) steps of Titan's atmospheric chemistry at low temperature as shown in the study presented here. We further illustrate the potential of COSmIC/THS for the simulation of Titan's atmospheric chemistry by presenting very promising results from a preliminary comparison of the laboratory data to data from the Cassini Plasma Spectrometer-Ion Beam Spectrometer (CAPS-IBS) instrument.

  13. Effect of solar electron temperature on pep solar neutrino flux in the chlorine solar neutrino experiment and the gallium solar neutrino experiment

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The rate of the electron-capture reaction of proton,p+e-+p→2H+ve , is calculated considering the temperature of solar electron in the solar center instead of that of solar ion. When the solar electron temperature is two times higher than the solar ion temperature in the solar center, the capture rate pep solar neutrino predicted by the standard solar model (SSM) is decreased to (0.16±0.01) SNU from (0.22±0.01) SNU in the chlorine solar neutrino experiment, and decreased to 2.19 SNU from 3.0 SNU in the gallium solar neutrino experiment.

  14. Phase relations and dehydration behaviour of calcareous sediments at P-T conditions of accretionary wedge systems

    Science.gov (United States)

    Massonne, H.-J.

    2009-04-01

    In a recent paper (Eur. J. Mineral. 20), Massonne and Willner (2008) presented P-T pseudosections for common rocks involved in accretionary wedge systems and argued that the dehydration of psammopelitic rocks could be an essential process for the formation of these systems. These authors assumed that this dehydration process leads to softening of the sedimentary cover of oceanic crust during early subduction so that this material can be scraped off the basic crust. Since many accretionary wedge systems contain metamorphosed calcareous sediments it was tested which influence carbonates, ignored by Massonne and Willner (2008), could have on the dehydration behaviour of these sediments. For this purpose, P-T pseudosections were calculated for a calcareous greywacke and a marly limestone in the system Na-Ca-K-Fe-Mn-Mg-Al-Si-Ti-C-O-H with the PERPLEX software package (Connolly, 2005) for the pressure-temperature range 1-25 kbar and 150-450°C. In addition to the thermodynamic data and solid solution models already used by Massonne and Willner (2008), a newly created quaternary (Ca-Mn-Mg-Fe2+) solid solution model was applied to carbonate with calcite structure together with an existing dolomite-ankerite model. Aragonite was considered as a pure phase. The Mn end-member was added to the previously used stilpnomelane model in order to calculate the P-T conditions of garnet formation at high pressure. Along a low geotherm of 10-12°C/km, the dehydration behaviour of a calcareous greywacke resembles that of the previously studied psammopelite. However, the relevant dehydration event (release of about 1 wt% H2O) occurs in the temperature interval 270-330°C and, thus, at temperatures about 30°C higher than in an ordinary psammopelite. The calculated compositions of fluids generated at low geotherms (

  15. Pressure and temperature dependence of growth and morphology of Escherichia coli: Experiments and Stochastic Model

    CERN Document Server

    Kumar, Pradeep

    2012-01-01

    We have investigated the growth of Escherichia coli E.coli, a mesophilic bacterium, as a function of pressure $P$ and temperature $T$. E.coli can grow and divide in a wide range of pressure (1-400atm) and temperature ($23-40^{\\circ}$C). For $T>30^{\\circ}$ C, the division time of E.coli increases exponentially with pressure and exhibit a departure from exponential behavior at pressures between 250-400 atm for all the temperatures studied in our experiments. For $T<30^{\\circ}$ C, the division time shows an anomalous dependence on pressure -- first decreases with increasing pressure and then increases upon further increase of pressure. The sharp change in division time is followed by a sharp change in phenotypic transition of E. Coli at high pressures where bacterial cells switch to an elongating cell type. We propose a model that this phenotypic changes in bacteria at high pressures is an irreversible stochastic process whereas the switching probability to elongating cell type increases with increasing press...

  16. Pressure and temperature dependence of growth and morphology of Escherichia coli: experiments and stochastic model.

    Science.gov (United States)

    Kumar, Pradeep; Libchaber, Albert

    2013-08-06

    We have investigated the growth of Escherichia coli, a mesophilic bacterium, as a function of pressure (P) and temperature (T). Escherichia coli can grow and divide in a wide range of pressure (1-400 atm) and temperature (23-40°C). For T > 30°C, the doubling time of E. coli increases exponentially with pressure and exhibits a departure from exponential behavior at pressures between 250 and 400 atm for all the temperatures studied in our experiments. The sharp change in doubling time is followed by a sharp change in phenotypic transition of E. coli at high pressures where bacterial cells switch to an elongating cell type. We propose a model that this phenotypic change in bacteria at high pressures is an irreversible stochastic process, whereas the switching probability to elongating cell type increases with increasing pressure. The model fits well the experimental data. We discuss our experimental results in the light of structural and thus functional changes in proteins and membranes.

  17. Degradation of Nafion due to contamination from Swelling-Dehydration Cycles

    DEFF Research Database (Denmark)

    Andersen, Shuang Ma; Morgen, Per; Skou, Eivind Morten

    degradation in direct methanol fuel cells (DMFCs), where liquid water has direct contact with the electrolyte. An ex-situ experiment was established with swelling-dehydration cycles on the membrane. However, formation of sulfonic anhydride was not detected during the entire treatment; instead contamination...... from traces calcium in the nominally pure water used in the experiment was found to be the primary reason for the deterioration of the membrane properties. Trace impurities in the liquid methanol feed in DMFC may therefore represent an important contamination source....

  18. High Temperature, Controlled-Atmosphere Aerodynamic Levitation Experiments with Applications in Planetary Science

    Science.gov (United States)

    Macris, C. A.; Badro, J.; Eiler, J. M.; Stolper, E. M.

    2016-12-01

    The aerodynamic levitation laser apparatus is an instrument in which spherical samples are freely floated on top of a stream of gas while being heated with a CO2laser to temperatures up to about 3500 °C. Laser heated samples, ranging in size from 0.5 to 3.5 mm diameter, can be levitated in a variety of chemically active or inert atmospheres in a gas-mixing chamber (e.g., Hennet et al. 2006; Pack et al. 2010). This allows for containerless, controlled-atmosphere, high temperature experiments with potential for applications in earth and planetary science. A relatively new technique, aerodynamic levitation has been used mostly for studies of the physical properties of liquids at high temperatures (Kohara et al. 2011), crystallization behavior of silicates and oxides (Arai et al. 2004), and to prepare glasses from compositions known to crystallize upon quenching (Tangeman et al. 2001). More recently, however, aerodynamic levitation with laser heating has been used as an experimental technique to simulate planetary processes. Pack et al. (2010) used levitation and melting experiments to simulate chondrule formation by using Ar-H2 as the flow gas, thus imposing a reducing atmosphere, resulting in reduction of FeO, Fe2O3, and NiO to metal alloys. Macris et al. (2015) used laser heating with aerodynamic levitation to reproduce the textures and diffusion profiles of major and minor elements observed in impact ejecta from the Australasian strewn field, by melting a powdered natural tektite mixed with 60-100 μm quartz grains on a flow of pure Ar gas. These experiments resulted in quantitative modeling of Si and Al diffusion, which allowed for interpretations regarding the thermal histories of natural tektites and their interactions with the surrounding impact vapor plume. Future experiments will employ gas mixing (CO, CO2, H2, O, Ar) in a controlled atmosphere levitation chamber to explore the range of fO2applicable to melt-forming impacts on other rocky planetary bodies

  19. Ingestive Behavior of Ovine Fed with Marandu Grass Silage Added with Naturally Dehydrated Brewery Residue.

    Science.gov (United States)

    de Jesus Ferreira, Daniele; de Moura Zanine, Anderson; de Paula Lana, Rogério; Lima de Souza, Alexandre; Divino Ribeiro, Marinaldo; Mattos Negrão, Fagton; Castro, Wanderson José Rodrigues; Nunes Parente, Henrique; Valério Geron, Luiz Juliano; de Azevedo Câmara, Larissa Rodrigues

    2016-01-01

    The objective was to evaluate the ingestive behavior of ovine fed Marandu grass silage with dehydrated brewery residue added. The experiment had a completely randomized design with five treatments and four repetitions, with the treatments levels of inclusion being of 0, 10, 20, 30, and 40% natural matter of naturally dehydrated brewery residue for 36 hours to the marandu grass silage. 20 ovines were used and the experimental period was 21 days, 15 being for adaptation to diets. The use of brewery byproduct promoted quadratic effect (P < 0.05) for the consumption of dry matter with maximum point value estimated at adding 23.25% additive. Ingestion efficiency and rumination efficiency of dry matter (g DM/hour) were significant (P < 0.05), by quadratic behavior, and NDF ingestion and rumination efficiency showed crescent linear behavior. The DM and NDF consumption expressed in kg/meal and in minutes/kg were also significant (P < 0.05), showing quadratic behavior. Rumination activity expressed in g DM and NDF/piece was influenced (P < 0.05) by the adding of brewery residue in marandu grass silage in quadratic way, with maximum value estimated of 1.57 g DM/bolus chewed in inclusion of 24.72% additive in grass silage. The conclusion is that intermediary levels adding of 20 to 25% dehydrated brewery residue affects certain parameters of ingestive behavior.

  20. Challenges of linking chronic dehydration and fluid consumption to health outcomes.

    Science.gov (United States)

    Armstrong, Lawrence E

    2012-11-01

    The purpose of this article is to review the effects of chronic mild dehydration and fluid consumption on specific health outcomes including obesity. The electronic databases PubMed and Google Scholar were searched for relevant literature published from the time of their inception to 2011, with results restricted to studies performed on human subjects and reports in the English language. Key words included the following: dehydration, hypohydration, water intake, fluid intake, disease, and the names of specific disease states. Strength of evidence categories were described for 1) medical conditions associated with chronic dehydration or low daily water intake, and 2) randomized-controlled trials regarding the effects of increased water consumption on caloric intake, weight gain, and satiety. This process determined that urolithiasis is the only disorder that has been consistently associated (i.e., 11 of 13 publications) with chronic low daily water intake. Regarding obesity and type 2 diabetes, evidence suggests that increased water intake may reduce caloric intake for some individuals. Recommendations for future investigations include measuring total fluid intake (water + beverages + water in solid food), conducting randomized-controlled experiments, identifying novel hydration biomarkers, and delineating hydration categories. © 2012 International Life Sciences Institute.

  1. The Effect of Drinking on Plasma Vasopressin and Renin in Dehydrated Human Subjects

    Science.gov (United States)

    Geelen, G.; Keil, L. C.; Kravik, S. E.; Wade, C. E.; Thrasher, T. N.; Barnes, P. R.; Pyka, G.; Nesvig, C.; Greenleaf, J. E.

    1996-01-01

    Oropharyngeal mechanisms activated by drinking have been shown to induce a rapid decline in plasma vasopressin which preceeds postabsorptive changes in plasma composition in the dehydrated dog. The present study was undertaken to determine what factor(s) inhibit(s) vasopressin secretion after rehydration in water deprived human subjects. Hematocrit (Hct) and hemoglobin (Hb) were determined on the day of the experiment, together with electrolytes and osmolalities which were measured on freshly separated serum. Plasma was immediately frozen and further analyzed by radioimmunoassay for renin activity (PRA), vasopressin (AVP), and aldosterone. The data were analyzed using an analysis of variance for repeated measurements and significant differences between the dehydrated control period and various time points after the start of rehydration were determined using a multiple-range test. began and reached water replete levels 15 minutes after drinking in the absence of any detectable decline in serum sodium or osmolality, we conclude that 427 oropharyngeal factors, alone or combined with gastric distension account for the extremely rapid inhibition of AVP secretion after drinking in the water-deprived human, as has been shown to be the case in dogs. Our findings are also in agreement wiht the recent demonstration that at the onset of drinking in the dehydrated monkey, there is an abrupt fall in plasma AVP concentration associated with a considerable decrease in the firing rate of the supraoptic neurosecretory neurons.

  2. Mild dehydration impairs cognitive performance and mood of men.

    Science.gov (United States)

    Ganio, Matthew S; Armstrong, Lawrence E; Casa, Douglas J; McDermott, Brendon P; Lee, Elaine C; Yamamoto, Linda M; Marzano, Stefania; Lopez, Rebecca M; Jimenez, Liliana; Le Bellego, Laurent; Chevillotte, Emmanuel; Lieberman, Harris R

    2011-11-01

    The present study assessed the effects of mild dehydration on cognitive performance and mood of young males. A total of twenty-six men (age 20·0 (sd 0·3) years) participated in three randomised, single-blind, repeated-measures trials: exercise-induced dehydration plus a diuretic (DD; 40 mg furosemide); exercise-induced dehydration plus placebo containing no diuretic (DN); exercise while maintaining euhydration plus placebo (EU; control condition). Each trial included three 40 min treadmill walks at 5·6 km/h, 5 % grade in a 27·7°C environment. A comprehensive computerised six-task cognitive test battery, the profile of mood states questionnaire and the symptom questionnaire (headache, concentration and task difficulty) were administered during each trial. Paired t tests compared the DD and DN trials resulting in >1 % body mass loss (mean 1·59 (sd 0·42) %) with the volunteer's EU trial (0·01 (sd 0·03) %). Dehydration degraded specific aspects of cognitive performance: errors increased on visual vigilance (P = 0·048) and visual working memory response latency slowed (P = 0·021). Fatigue and tension/anxiety increased due to dehydration at rest (P = 0·040 and 0·029) and fatigue during exercise (P = 0·026). Plasma osmolality increased due to dehydration (P dehydration without hyperthermia in men induced adverse changes in vigilance and working memory, and increased tension/anxiety and fatigue.

  3. Rate of Dehydration and Cumulative Desiccation Stress Interacted to Modulate Desiccation Tolerance of Recalcitrant Cocoa and Ginkgo Embryonic Tissues1

    Science.gov (United States)

    Liang, Yongheng; Sun, Wendell Q.

    2002-01-01

    Rate of dehydration greatly affects desiccation tolerance of recalcitrant seeds. This effect is presumably related to two different stress vectors: direct mechanical or physical stress because of the loss of water and physicochemical damage of tissues as a result of metabolic alterations during drying. The present study proposed a new theoretic approach to represent these two types of stresses and investigated how seed tissues responded differently to two stress vectors, using the models of isolated cocoa (Theobroma cacao) and ginkgo (Ginkgo biloba) embryonic tissues dehydrated under various drying conditions. This approach used the differential change in axis water potential (ΔΨ/Δt) to quantify rate of dehydration and the intensity of direct physical stress experienced by embryonic tissues during desiccation. Physicochemical effect of drying was expressed by cumulative desiccation stress [∫\\documentclass[10pt]{article} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\pagestyle{empty} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} \\begin{equation*}{\\mathrm{_{o}^{t}}}\\end{equation*}\\end{document}f(ψ,t)], a function of both the rate and time of dehydration. Rapid dehydration increased the sensitivity of embryonic tissues to desiccation as indicated by high critical water contents, below which desiccation damage occurred. Cumulative desiccation stress increased sharply under slow drying conditions, which was also detrimental to embryonic tissues. This quantitative analysis of the stress-time-response relationship helps to understand the physiological basis for the existence of an optimal dehydration rate, with which maximum desiccation tolerance could be achieved. The established numerical analysis model will prove valuable for the design of experiments that aim to elucidate biochemical and physiological mechanisms of desiccation tolerance. PMID:11950981

  4. Probing soil C metabolism in response to temperature: results from experiments and modeling

    Science.gov (United States)

    Dijkstra, P.; Dalder, J.; Blankinship, J.; Selmants, P. C.; Schwartz, E.; Koch, G. W.; Hart, S.; Hungate, B. A.

    2010-12-01

    C use efficiency (CUE) is one of the least understood aspects of soil C cycling, has a very large effect on soil respiration and C sequestration, and decreases with elevated temperature. CUE is directly related to substrate partitioning over energy production and biosynthesis. The production of energy and metabolic precursors occurs in well-known processes such as glycolysis and Krebs cycle. We have developed a new stable isotope approach using position-specific 13C-labeled metabolic tracers to measure these fundamental metabolic processes in intact soil communities (1). We use this new approach, combined with models of soil metabolic flux patterns, to analyze the response of microbial energy production, biosynthesis, and CUE to temperature. The method consists of adding small but precise amounts of position-specific 13C -labeled metabolic tracers to parallel soil incubations, in this case 1-13C and 2,3-13C pyruvate and 1-13C and U-13C glucose. The measurement of CO2 released from the labeled tracers is used to calculate the C flux rates through various metabolic pathways. A simplified metabolic model consisting of 23 reactions is iteratively solved using results of the metabolic tracer experiments and information on microbial precursor demand under different temperatures. This new method enables direct study of fundamental aspects of microbial energy production, C use efficiency, and soil organic matter formation in response to temperature. (1) Dijkstra P, Blankinship JC, Selmants PC, Hart SC, Koch GW, Schwarz E and Hungate BA. Probing metabolic flux patterns of soil microbial communities using parallel position-specific tracer labeling. Soil Biology and Biochemistry (accepted)

  5. Early Silicate Liquid Immiscibility in the Skaergaard Intrusion: Evidence from high Temperature Centrifugation Experiments

    Science.gov (United States)

    Veksler, I.; Dorfman, A. M.; Borisov, A. A.; Wirth, R.; Dingwell, D. B.

    2007-12-01

    Immiscible droplet textures are common in groundmass glasses and plagioclase-hosted melt inclusions of tholeiitic basalts (Philpotts, 1982). Our experiments on synthetic analogues of natural immiscible basaltic-rhyolitic glasses showed that conventional quenching experiments in 1-atm gas mixing furnaces were in most cases unable to reproduce unmixing yielding instead either turbid, opalescent glasses, or crystallization of tridymite and pyroxenes. In contrast, experiments involving in situ high-temperature centrifugation at 1000g on some of the liquids did yield macroscopic unmixing and phase separation. It appears that experimental reproduction of immiscibility in complex ferrobabsaltic aluminosilicate melts is hampered by nucleation barrier, metastable crystallization, and sluggish phase separation kinetics. Three-four hours of centrifugation were insufficient to complete phase segregation, and resulted in sub-micron immiscible emulsions in quenched glasses. For a model liquid composition of the Middle Zone of the Skaergaard intrusion obtained from experiments by Toplis and Carroll (1995) centrifugation at super-liquidus temperatures of 1110-1120 degrees C, produced a thin, silicic layer (64.5 wt.% SiO2 and 7.4 wt.% FeO) at the top of the main Fe-rich glass (46 wt.% SiO2 and 21 wt.% FeO). Transmission electron microscopy of the quenched products revealed silica-rich immiscible globules of about 20--30 nm in diameter suspended in the Fe-rich glass. The globules are however not a quench feature because they moved during centrifugation over a few millimeters of the sample length and eventually accumulated in the thin (0.2 mm) silicic liquid layer at the top. The divergent compositions of the top and at the bottom were shown in a series of static runs to crystallize very similar crystal assemblages of plagioclase, pyroxene, olivine, and Fe-Ti oxides. In light of our centrifuge experiments, immiscibility in the Skaergaard intrusion may have started already at the

  6. Temperature distribution in the upper layers of the northern and eastern Arabian Sea during Indo-Soviet monsoon experiment

    Digital Repository Service at National Institute of Oceanography (India)

    RameshBabu, V.; Rao, L.V.G.; Varkey, M.J.; Udayavarma, P.

    -Soviet Monsoon Experiment (ISMEX). Using the bathythermograph data collected in those cruises, vertical distribution of temperature in the upper 275 metres was studied. Along the zonal section, east of 67 degrees E meridian, the depth of thermocline was found...

  7. Effects of body temperature and hydration state on organismal performance of toads, Bufo americanus.

    Science.gov (United States)

    Preest, Marion R; Pough, F Harvey

    2003-01-01

    Temperature and humidity are dominant environmental variables affecting performance of nocturnal, terrestrial amphibians. Toads are frequently active at body temperatures (T(b)) and hydration states (HS) that yield suboptimal performance. We investigated the combined effects of T(b) and HS on feeding, locomotion, and metabolism of Bufo americanus. More toads responded to the presence of prey when fully hydrated than when dehydrated, and times to orient to prey, maneuver around a barrier, and reach prey were less in hydrated than in dehydrated animals. Time to capture prey decreased with increasing T(b) in fully hydrated, but not dehydrated, toads, and hydrated animals caught prey more rapidly than did dehydrated animals. Distance traveled in 5 min and aerobic scope were affected by T(b). Generally, individuals that performed well in the feeding experiments at a particular T(b) and HS also performed well at a different T(b) and HS. The same was true for distance traveled and aerobic scope. However, within combinations of T(b) and HS, correlations between performance variables were minimal. Specialization of a particular variable resulting in high performance at a certain T(b) and HS does not appear to exact a cost in terms of performance at a different T(b) and HS.

  8. Uncertainty Quantification of Calculated Temperatures for the AGR 3/4 Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Pham, Binh Thi-Cam [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-09-01

    A series of Advanced Gas Reactor (AGR) irradiation experiments are being conducted within the Advanced Reactor Technology (ART) Fuel Development and Qualification Program. The main objectives of the fuel experimental campaign are to provide the necessary data on fuel performance to support fuel process development, qualify a fuel design and fabrication process for normal operation and accident conditions, and support development and validation of fuel performance and fission product transport models and codes (PLN 3636, “Technical Program Plan for INL Advanced Reactor Technologies Technology Development Office/Advanced Gas Reactor Fuel Development and Qualification Program”). The AGR 3/4 test was inserted in the Northeast Flux Trap position in the Advanced Test Reactor (ATR) core at Idaho National Laboratory (INL) in December 2011 and successfully completed irradiation in mid-April 2014, resulting in irradiation of the tristructural isotropic (TRISO) fuel for 369.1 effective full-power days (EFPDs) during approximately 2.4 calendar years. The AGR 3/4 data, including the irradiation data and calculated results, were qualified and stored in the Nuclear Data Management and Analysis System (NDMAS). To support the U.S. TRISO fuel performance assessment and to provide data for validation of fuel performance and fission product transport models and codes, the daily as run thermal analysis has been performed separately on each of twelve AGR 3/4 capsules for the entire irradiation as discussed in ECAR-2807, “AGR 3/4 Daily As Run Thermal Analyses”. The ABAQUS code’s finite element-based thermal model predicts the daily average volume average (VA) fuel temperature (FT), peak FT, and graphite matrix, sleeve, and sink temperature in each capsule. The JMOCUP simulation codes were also created to perform depletion calculations for the AGR 3/4 experiment (ECAR-2753, “JMOCUP As-Run Daily Physics Depletion Calculation for the AGR 3/4 TRISO Particle Experiment in ATR

  9. Progressive evolution of microfabrics in high-temperature indentation creep experiments

    Science.gov (United States)

    Wassmann, S.; Dorner, D.; Stoeckhert, B.

    2014-12-01

    Microfabrics of natural rocks as well as of those deformed in laboratory experiments are studied post-mortem, the history of fabric evolution being inferred from a finite state. This is a major drawback when being interested in modification of fabrics related to progressive deformation. Here we present a novel approach to analyze and compare fabrics in different stages of evolution, taking spatial position to mimic a time series. Using this approach, evolution in time can be investigated on one sample deformed in a single indentation creep test. Such experiments at high temperatures and atmospheric pressure provide information on mechanical properties of rock-forming minerals as well as on microfabrics developed during inhomogeneous deformation underneath the indenter. Using a conventional creep apparatus, a cylindrical alumina indenter, 2 mm in diameter, is driven by a dead load into the flat surface of a specimen. A penetration depth of 1 mm is typically reached after hours to days, depending on material, applied temperature, and load. Previous experiments on natural, polycrystalline anhydrite carried out at temperatures between 700°C and 920 °C yield a stress exponent of 3.9 indicating deformation in the dislocation creep regime, consistent with microstructural observations (Dorner et al., 2014; Solid Earth). Within a cone-shaped region in front of the indenter, the original microfabric appears entirely unaffected. The neutral cone is mantled by highly deformed shear zones. During progressive indentation this structure of undeformed cone and shear zones propagates into the specimen. Thus, for a homogeneous starting material, serial sections of the deformed specimen normal to the indenter axis provide insight into fabrics in distinct stages of evolution. Microfabrics developed at different distance in front of the approaching indenter can be taken to represent a time series. A disadvantage of the technique is that the history of shear zone deformation is

  10. Polymerization Experiment Of Amino Acids Under High Pressure And Temperature Conditions Simulating The Deep Lithosphere

    Science.gov (United States)

    Ohara, S.; Kakegawa, T.; Nakazawa, H.

    2005-12-01

    Chemical evolution in deep sea or deep lithosphere is one of the popular hypotheses for the origin of life on the early Earth. In such hypothesis, effects of pressure and temperature on polymerization (and/or stability) of amino acids needed to be evaluated. In this study, high temperature and pressure experiments were performed using of a test-tube-type autoclave for polymerization of amino acids. Approximately 100 mg of Glycine powder were placed into sterilized gold capsule. Multiple experiments were done at 150 degrees for 1 to 8 days at variable pressures (25MPa, 50MPa, 75MPa and 100MPa). Glycine peptides were identified and quantified by high performance liquid chromatography (HPLC). Each capsule was opened carefully and 1 ml of mobile phase was added to release the amino acids and oligopeptide from the solid phase. Liquid phases were separated by the cetrifugal method. Peptides were identified by retention times of authentic reference substances. The reaction yields were determined as percentage of the reactant converted to the reaction product. Pligopeptides more than hexamer were additionally identified by the detection of the molecular ion by liquid chromatography mass spectrometry (LC / MS). A HPLC chromatogram of the products indicated at least seven oligomers: diketopiperazine (cyc(Gly)2), di-glycine (Gly2), tri-glycine (Gly3), tetra-glycine (Gly4), penta-glycine (Gly5) and hexa-glycine (Gly6). We also identified hepta-glycine (Gly7), octa-glycine (Gly8) and nona-glycine (Gly9) with LC/MS. This is the first report that up to nona-glycine was synthesized under high temperature and pressure conditions. In addition, our experiments indicate that polymerization occurs wide range of pressure from 25 to 100 MPa. On the other hand, yields of total amounts of peptide did not change with pressure, suggesting that an unknown process in the autoclave is limiting the yield. We speculate the activity of water vapor, generated by peptide formation reaction

  11. Urinary caffeine after coffee consumption and heat dehydration.

    Science.gov (United States)

    Chambaz, A; Meirim, I; Décombaz, J

    2001-07-01

    This study evaluated the effect of heat-induced dehydration on urinary caffeine excretion after the consumption of a strong coffee solution. Following ingestion of coffee (caffeine 4.9+/-0.1 [SE] mg/kg, 3-4 cups), ten healthy males were intermittently exposed to heat in a sauna until they had lost 2.9 % of lean mass. On a separate occasion, they consumed the same amount of coffee but remained quiet and euhydrated (control). Urine flow was reduced 7-fold in dehydration. At these low excretion rates (caffeine concentration was negatively correlated with flow. Peak urinary caffeine (Cmax) was 7.6 +/- 0.4 (SE) microg/ml in dehydration and 7.1 +/- 0.2 microg/ml in the control (p > 0.05). Compared with the control, dehydration delayed Cmax by 1 hour, maintained higher saliva caffeine concentration (6.1 vs 5.2 microg/ml, p caffeine ratio (p caffeine in urine was reduced (1.2 vs 2.8% of dose, p caffeine due to delayed metabolic clearance was partly opposed by a sizeable elimination in sweat. Therefore, heat dehydration did not lead to higher concentration of caffeine in urine after coffee ingestion.

  12. Using Dehydrated Vegetables in Some Brown Bread Types

    Directory of Open Access Journals (Sweden)

    Simona Man

    2013-11-01

    Full Text Available Normal 0 false false false MicrosoftInternetExplorer4 Expanding the range of bakery products in terms of producing supplemented or dietetic products has been an increasingly important trend in contemporary baking. Bakery products as basic and popular food, could be used in the prevention of nutritive deficiencies of many important nutrients, by supplementing the products with biologically valuable ingredients. Such ingredients are dehydrated vegetables in the form of powder. For establishing the bread quality, a special importance shows it’s chemical composition, because the substances that enter in it’s constitution serve to obtaining the energy necessary to the human body. Beside the chemical composition, the bread quality and alimentary use, respectively, depends a large measure on a series of signs: flavor and taste, external appearance, crumb porosity and texture, breads’ volume. This paper belongs to a more complex study, which aims are obtaining some bread assortments with high nutritional value, and improving their sensorial and rheological features, by adding dehydrated vegetables at different levels 4% potato flakes, 2% dehydrated onion, 0.5% dehydrated garlic and 2% dehydrated leek.

  13. Kinetic, Spectroscopic, and Theoretical Assessment of Associative and Dissociative Methanol Dehydration Routes in Zeolites

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Andrew J.; Iglesia, Enrique

    2014-11-03

    Mechanistic interpretations of rates and in situ IR spectra combined with density functionals that account for van der Waals interactions of intermediates and transition states within confining voids show that associative routes mediate the formation of dimethyl ether from methanol on zeolitic acids at the temperatures and pressures of practical dehydration catalysis. Methoxy-mediated dissociative routes become prevalent at higher temperatures and lower pressures, because they involve smaller transition states with higher enthalpy, but also higher entropy, than those in associative routes. These enthalpy–entropy trade-offs merely reflect the intervening role of temperature in activation free energies and the prevalence of more complex transition states at low temperatures and high pressures. This work provides a foundation for further inquiry into the contributions of H-bonded methanol and methoxy species in homologation and hydrocarbon synthesis reactions from methanol.

  14. Kinetic, spectroscopic, and theoretical assessment of associative and dissociative methanol dehydration routes in zeolites.

    Science.gov (United States)

    Jones, Andrew J; Iglesia, Enrique

    2014-11-01

    Mechanistic interpretations of rates and in situ IR spectra combined with density functionals that account for van der Waals interactions of intermediates and transition states within confining voids show that associative routes mediate the formation of dimethyl ether from methanol on zeolitic acids at the temperatures and pressures of practical dehydration catalysis. Methoxy-mediated dissociative routes become prevalent at higher temperatures and lower pressures, because they involve smaller transition states with higher enthalpy, but also higher entropy, than those in associative routes. These enthalpy-entropy trade-offs merely reflect the intervening role of temperature in activation free energies and the prevalence of more complex transition states at low temperatures and high pressures. This work provides a foundation for further inquiry into the contributions of H-bonded methanol and methoxy species in homologation and hydrocarbon synthesis reactions from methanol.

  15. The THS Experiment: Simulating Titans Atmospheric Chemistry at Low Temperature (200K)

    Science.gov (United States)

    Sciamma-O'Brien, Ella; Upton, Kathleen; Beauchamp, Jack L.; Salama, Farid; Contreras, Cesar Sanchez; Bejaoui, Salma; Foing, Bernard; Pascale, Ehrenfreund

    2015-01-01

    In Titan's atmosphere, composed mainly of N2 (95-98%) and CH4 (2-5%), a complex chemistry occurs at low temperature, and leads to the production of heavy organic molecules and subsequently solid aerosols. Here, we used the Titan Haze Simulation (THS) experiment, an experimental setup developed at the NASA Ames COSmIC simulation facility to study Titan's atmospheric chemistry at low temperature. In the THS, the chemistry is simulated by plasma in the stream of a supersonic expansion. With this unique design, the gas is cooled to Titan-like temperature ( approximately 150K) before inducing the chemistry by plasma, and remains at low temperature in the plasma discharge (approximately 200K). Different N2-CH4-based gas mixtures can be injected in the plasma, with or without the addition of heavier precursors present as trace elements on Titan, in order to monitor the evolution of the chemical growth. Both the gas- and solid phase products resulting from the plasma-induced chemistry can be monitored and analyzed using a combination of complementary in situ and ex situ diagnostics. A recent mass spectrometry[1] study of the gas phase has demonstrated that the THS is a unique tool to probe the first and intermediate steps of Titan's atmospheric chemistry at Titan-like temperature. In particular, the mass spectra obtained in a N2-CH4-C2H2-C6H6 mixture are relevant for comparison to Cassini's CAPS-IBS instrument. The results of a complementary study of the solid phase are consistent with the chemical growth evolution observed in the gas phase. Grains and aggregates form in the gas phase and can be jet deposited on various substrates for ex situ analysis. Scanning Electron Microscopy images show that more complex mixtures produce larger aggregates. A mass spectrometry analysis of the solid phase has detected the presence of aminoacetonitrile, a precursor of glycine, in the THS aerosols. X-ray Absorption Near Edge Structure (XANES) measurements also show the presence of imine

  16. Shift of the critical mixing temperature in strong electric fields. Theory and experiment.

    Science.gov (United States)

    Orzechowski, Kazimierz; Adamczyk, Mariusz; Wolny, Alicja; Tsori, Yoav

    2014-06-26

    We study the shift in the critical temperature T(c) in binary mixtures in strong electric fields. In experiments we measure the nonlinear dielectric effect (NDE) in a mixture of nitrobenze and n-octane and calculate Piekara's factor. We find that the critical anomaly of Piekara's factor is a function of an electric field strength. We propose to explain this observation as a result of a downward shift of T(c), and this allows us to calculate (∂T(c)/∂E(2)) = (-22 ± 10) × 10(-16) (K m(2))/V(2). In the theoretical part we amend Landau and Lifshitz's formula and show that the downward shift of Tc can be estimated from a simple mean-field theory taking into account the linear and quadratic terms in an expansion of the constitutive relation ε(x) between the electric constant ε and mixture composition x.

  17. Implications for Core Formation of the Earth from High Pressure-Temperature Au Partitioning Experiments

    Science.gov (United States)

    Danielson, L. R.; Sharp, T. G.; Hervig, R. L.

    2005-01-01

    Siderophile elements in the Earth.s mantle are depleted relative to chondrites. This is most pronounced for the highly siderophile elements (HSEs), which are approximately 400x lower than chondrites. Also remarkable is the relative chondritic abundances of the HSEs. This signature has been interpreted as representing their sequestration into an iron-rich core during the separation of metal from silicate liquids early in the Earth's history, followed by a late addition of chondritic material. Alternative efforts to explain this trace element signature have centered on element partitioning experiments at varying pressures, temperatures, and compositions (P-T-X). However, first results from experiments conducted at 1 bar did not match the observed mantle abundances, which motivated the model described above, a "late veneer" of chondritic material deposited on the earth and mixed into the upper mantle. Alternatively, the mantle trace element signature could be the result of equilibrium partitioning between metal and silicate in the deep mantle, under P-T-X conditions which are not yet completely identified. An earlier model determined that equilibrium between metal and silicate liquids could occur at a depth of approximately 700 km, 27(plus or minus 6) GPa and approximately 2000 (plus or minus 200) C, based on an extrapolation of partitioning data for a variety of moderately siderophile elements obtained at lower pressures and temperatures. Based on Ni-Co partitioning, the magma ocean may have been as deep as 1450 km. At present, only a small range of possible P-T-X trace element partitioning conditions has been explored, necessitating large extrapolations from experimental to mantle conditions for tests of equilibrium models. Our primary objective was to reduce or remove the additional uncertainty introduced by extrapolation by testing the equilibrium core formation hypothesis at P-T-X conditions appropriate to the mantle.

  18. Scaling of viscosity with rate, pressure, and temperature: Linking simulations to experiments

    Science.gov (United States)

    Jadhao, Vikram; Robbins, Mark

    Elastohydrodynamic lubrication (EHL) is important in many practical devices and produces extreme pressures (> 1 GPa) and shear rates (105 -107 s-1). This makes EHL fluids ideal candidates for bridging the gap between experimental and simulation studies of viscosity. There is an ongoing debate about whether the high-rate response of simple molecules like squalane follows a power-law Carreau model or a thermal activation based Eyring model. We use molecular dynamics simulations to investigate the rheological response of squalane for a wide range of rates (105 -1010 s-1), pressures (0.1 MPa to 3 GPa), and temperatures (100 - 313 K). We find that experimental and theoretical results can be collapsed onto a master curve consistent with Eyring theory over more than 20 orders of magnitude in rate. Extrapolating Eyring fits to simulations at 107 s-1 and above yields Newtonian viscosities η0 that are consistent with available low-rate experiments, and allows predictions to much higher pressures and lower temperatures. There is no indication of a diverging viscosity at finite stress, since log η0 rises sublinearly with pressure up to 6 GPa and η0 >1012 Pa-s. Correlations between chain conformations and Eyring parameters are also presented. This research was performed within the Center for Materials in Extreme Dynamic Environments (CMEDE) under the Hopkins Extreme Materials Institute at Johns Hopkins University. Financial support was provided by Grant W911NF-12-2-0022.

  19. Hydrogen oxidation at high pressure and intermediate temperatures: experiments and kinetic modeling

    DEFF Research Database (Denmark)

    Hashemi, Hamid; Christensen, Jakob Munkholt; Gersen, Sander

    2015-01-01

    Hydrogen oxidation at 50 bar and temperatures of 700–900 K was investigated in a high pressure laminar flow reactor under highly diluted conditions. The experiments provided information about H 2 oxidation at pressures above the third explosion limit. The fuel–air equivalence ratio of the reactants...... was varied from very oxidizing to strongly reducing conditions. The results supplement high-pressure data from RCM (900–1100 K) and shock tubes (900–2200 K). At the reducing conditions ( U = 12), oxidation started at 748–775 K while it was shifted to 798–823 K for stoichiometric and oxidizing conditions ( U...... = 1.03 and 0.05). At very oxidizing conditions (O 2 atmosphere, U = 0.0009), the temperature for onset of reaction was reduced to 775–798 K. The data were interpreted in terms of a detailed chemical kinetic model, drawn mostly from work of Burke and coworkers. In the present study, the rate constants...

  20. Design of a high-temperature experiment for evaluating advanced structural materials

    Science.gov (United States)

    Mockler, Theodore T.; Castro-Cedeno, Mario; Gladden, Herbert J.; Kaufman, Albert

    1992-01-01

    This report describes the design of an experiment for evaluating monolithic and composite material specimens in a high-temperature environment and subject to big thermal gradients. The material specimens will be exposed to aerothermal loads that correspond to thermally similar engine operating conditions. Materials evaluated in this study were monolithic nickel alloys and silicon carbide. In addition, composites such as tungsten/copper were evaluated. A facility to provide the test environment has been assembled in the Engine Research Building at the Lewis Research Center. The test section of the facility will permit both regular and Schlieren photography, thermal imaging, and laser Doppler anemometry. The test environment will be products of hydrogen-air combustion at temperatures from about 1200 F to as high as 4000 F. The test chamber pressure will vary up to 60 psia, and the free-stream flow velocity can reach Mach 0.9. The data collected will be used to validate thermal and stress analysis models of the specimen. This process of modeling, testing, and validation is expected to yield enhancements to existing analysis tools and techniques.

  1. Effects of dehydration and fluid ingestion on cognition.

    Science.gov (United States)

    Tomporowski, P D; Beasman, K; Ganio, M S; Cureton, K

    2007-10-01

    The effects of exercise-induced dehydration and fluid ingestion on men's cognitive performance were assessed. Eleven young men attended separate sessions in which each individual cycled in a controlled environment at 60 % of V.O (2max) for periods of 15, 60, or 120 min without fluid replacement or 120 min with fluid replacement. Immediately following the assigned submaximal exercise period, the participant completed a graded exercise test to voluntary exhaustion. An executive processing test and a short-term memory test were performed prior to and immediately following exercise. Choice-response times during the executive processing test decreased following exercise, regardless of the level of dehydration. Choice-response errors increased following exercise, but only on trials requiring set shifting. Short-term memory performance improved following exercise, regardless of the level of dehydration. Changes in cognitive performance following exercise are hypothesized to be related to metabolic arousal following strenuous physical activity.

  2. Functional and technological potential of dehydrated Phaseolus vulgaris L. flours.

    Science.gov (United States)

    Ramírez-Jiménez, A K; Reynoso-Camacho, R; Mendoza-Díaz, S; Loarca-Piña, G

    2014-10-15

    The effect of cooking followed by dehydration was evaluated on the bioactive composition, antioxidant activity and technological properties of two varieties (Negro 8025 and Bayo Madero) of common beans. Quercetin, rutin, and phenolic acids were the most abundant phenolics found. Cooking processes resulted in decreased values of some phenolic compounds and antioxidant capacity. A subsequent dehydration increased TEAC values, resistant starch content and decreased starch digestibility. Oligosaccharides and dietary fibre were preserved in both treatments. Variety had a strong impact on phytochemical profile, being Negro 8025 that exhibited the highest content of most of the compounds assessed. Water absorption index (WAI) and oil absorption capacity (OAC) were determined in order to measure technological suitability. Dehydration produced flours with stable WAI and low oil pick up. The results suggest that the flours of Negro 8025 beans have a good potential to be considered as functional ingredient for healthy food products. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Optimization of Vacuum Frying Parameters in Combination with Osmotic Dehydration of Kiwi Slices to Produce Healthy Product

    Directory of Open Access Journals (Sweden)

    Fatemeh Aghabozorg Afjeh Aghabozorg Afjeh

    2014-05-01

    Full Text Available Osmotic dehydration under discontinuous reduced pressure is one of the new methods of preparation fruits and vegetable processing with in view of good health. Processing of foods at high temperatures used to cook them can cause the formation of carcinogenic substances like acrylamide, and this risk remains even if the trans-fat is removed. The low temperatures employed in this method resulted in the products with the desired texture, nutritional, and colour. The purpose of this research was evaluation of the variable effects of osmotic dehydration process (ambient pressure, contact time of product and solution, concentration and temperature of osmotic solution on the quality factors of product (colour changes, texture, moisture, oil uptake, and water loss to solid gain ratio and achieving the optimum process conditions. Studying the quality parameters of the product, the temperature range of osmotic solution, pressure, concentration of the osmotic solution and contact time of product and solution were assumed as 30 to 50°C, 500 to 700 mbar, 30 to 50% and 60 to 180 min, respectively. The test plans involving 31 tests were obtained by using response surface statistical models and central composite design. They were fried at the condition of 108ºC, 8 min and 320 mbar by using statistical correlations, 48.71ºC for the osmotic solution temperature, 592.07 mbar for the pressure, 62.92 min for the time and 34.87% for the osmotic solution. Concentrations were obtained as optimum conditions of osmotic dehydration of kiwi slices under reduced pressure. In summary combination of osmotic dehydration and vacuum frying improved the quality of the final fried kiwi, so this method is recommended for production of healthy products.

  4. Laboratory experiments on the impact disruption of iron meteorites at temperature of near-Earth space

    Science.gov (United States)

    Katsura, Takekuni; Nakamura, Akiko M.; Takabe, Ayana; Okamoto, Takaya; Sangen, Kazuyoshi; Hasegawa, Sunao; Liu, Xun; Mashimo, Tsutomu

    2014-10-01

    Iron meteorites and some M-class asteroids are generally understood to be fragments that were originally part of cores of differentiated planetesimals or part of local melt pools on primitive bodies. The parent bodies of iron meteorites may have formed in the terrestrial planet region, from which they were then scattered into the main belt (Bottke, W.F., Nesvorný, D., Grimm, R.E., Morbidelli, A., O'Brien, D.P. [2006]. Nature 439, 821-824). Therefore, a wide range of collisional events at different mass scales, temperatures, and impact velocities would have occurred between the time when the iron was segregated and the impact that eventually exposed the iron meteorites to interplanetary space. In this study, we performed impact disruption experiments of iron meteorite specimens as projectiles or targets at room temperature to increase understanding of the disruption process of iron bodies in near-Earth space. Our iron specimens (as projectiles or targets) were almost all smaller in size than their counterparts (as targets or projectiles, respectively). Experiments of impacts of steel specimens were also conducted for comparison. The fragment mass distribution of the iron material was different from that of rocks. In the iron fragmentation, a higher percentage of the mass was concentrated in larger fragments, probably due to the ductile nature of the material at room temperature. The largest fragment mass fraction f was dependent not only on the energy density but also on the size d of the specimen. We assumed a power-law dependence of the largest fragment mass fraction to initial peak pressure P0 normalized by a dynamic strength, Y, which was defined to be dependent on the size of the iron material. A least squares fit to the data of iron meteorite specimens resulted in the following relationship: f∝∝d, indicating a large size dependence of f. Additionally, the deformation of the iron materials in high-velocity shots was found to be most significant when the

  5. Investigating pyroclast ejection dynamics using shock-tube experiments: temperature, grain size and vent geometry effects.

    Science.gov (United States)

    Cigala, V.; Kueppers, U.; Dingwell, D. B.

    2015-12-01

    Explosive volcanic eruptions eject large quantities of gas and particles into the atmosphere. The portion directly above the vent commonly shows characteristics of underexpanded jets. Understanding the factors that influence the initial pyroclast ejection dynamics is necessary in order to better assess the resulting near- and far-field hazards. Field observations are often insufficient for the characterization of volcanic explosions due to lack of safe access to such environments. Fortunately, their dynamics can be simulated in the laboratory where experiments are performed under controlled conditions. We ejected loose natural particles from a shock-tube while controlling temperature (25˚ and 500˚C), overpressure (15MPa), starting grain size distribution (1-2 mm, 0.5-1 mm and 0.125-0.250 mm), sample-to-vent distance and vent geometry. For each explosion we quantified the velocity of individual particles, the jet spreading angle and the production of fines. Further, we varied the setup to allow for different sample-to-gas ratios and deployed four different vent geometries: 1) cylindrical, 2) funnel with a flaring of 30˚, 3) funnel with a flaring of 15˚ and 4) nozzle. The results showed maximum particle velocities up to 296 m/s, gas spreading angles varying from 21˚ to 37˚ and particle spreading angles from 3˚ to 40˚. Moreover we observed dynamically evolving ejection characteristics and variations in the production of fines during the course of individual experiments. Our experiments mechanistically mimic the process of pyroclast ejection. Thus the capability for constraining the effects of input parameters (fragmentation conditions) and conduit/vent geometry on ballistic pyroclastic plumes has been clearly established. These data obtained in the presence of well-documented conduit and vent conditions, should greatly enhance our ability to numerically model explosive ejecta in nature.

  6. EPR study on gamma-irradiated fruits dehydrated via osmosis

    Energy Technology Data Exchange (ETDEWEB)

    Yordanov, N.D. [Laboratory EPR, Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria)]. E-mail: ndyepr@bas.bg; Aleksieva, K. [Laboratory EPR, Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria)

    2007-06-15

    The shape and time stability of the electron paramagnetic resonance (EPR) spectra of non- and {gamma}-irradiated papaya, melon, cherry and fig samples dehydrated via osmosis are reported. It is shown that non-irradiated samples are generally EPR silent whereas {gamma}-irradiated exhibit 'sugar-like' EPR spectra. The recorded EPR spectra are monitored for a period of 7 months after irradiation (stored at low humidity and in the dark). The results suggest longer period of unambiguous identification of the radiation processing of osmose dehydrated fruits. Therefore, the Protocol EN 13708,2001 issued by CEN is fully applicable for the studied fruit samples.

  7. Effects of appropriate dehydration treatment on physiology and biochemistry of Actinidia arguta during postharvest stored under 20 ℃%采后适当失水处理对软枣猕猴桃20℃下生理生化变化的影响

    Institute of Scientific and Technical Information of China (English)

    姜丹; 张博; 李书倩; 翁霞; 刘长江; 辛广

    2013-01-01

    [Objective]This study aimed at investigating the effecf of dehydration treatment on postharvest physiology of Actinidia arguta Sieb. et Zucc. [Method] The fruits were stored at room temperature(20± 0.5)℃ after dehydration treatment, and the dehydration rate was 2%, 4% and 6%, respectively. The effect of dehydration treatment on postharvest physiology of Actinidia arguta was discussed. [Result]The results demonstrated that appropriate dehydration could both restrain the respiration intensity of Actinidia arguta and postpone the peak time, and also could inhibite the release of ethylene, postpone the peak of ethylene and the arrival of climacteric. The peak valume was reduced by this treatment. Proper dehydration could reduce pectinase activity, and inhibit decomposition of pectin during the whole storage. This treatment maintained the fruit firmness and flavor, and therefore, the fruit maturation and aging process were delayed. Among the three dehydration rates, 4% of fruit dehydration had a significant performance. When the fruits treated with dehydration of 4% stored 10 days, the decay rate was 37.23%, which was significantly lower than that of the other treatment groups(P<0.05). [Conclusion]Thus the experiment indicated that dehydration rate of 4% had fairly good effects on the storage and fresh-keeping of Actinidia arguta.%[目的]为了探讨失永处理对采后软枣猕猴桃生理生化变化的影响,[方法]以软枣猕猴桃为试验材料,研究了失水率分别为0、2%、4%、6%的软枣猕猴桃,在温度(20±0.5)℃条件下贮藏过程中生理生化变化.[结果]结果表明,适当失水处理可有效抑制软枣猕猴桃果实的呼吸作用,降低呼吸强度和推迟呼吸高峰出现;同时也抑制乙烯的释放量,推迟乙烯高峰和呼吸跃变的到来,并降低其峰值;适当失水处理也明显降低了软枣猕猴桃的果胶酶活性,抑制了果胶的降解,保持了果实硬度和风味,从而延缓软枣猕猴

  8. The THS Experiment: Ex Situ Analyses of Titan's Aerosol Analogs Produced at Low Temperature (200K)

    Science.gov (United States)

    Sciamma-O'Brien, E. M.; Upton, K. T.; Beauchamp, J. L.; Salama, F.

    2014-12-01

    In the study presented here, we used the COSmIC/Titan Haze Simulation (THS) experiment, an experimental platform developed to study Titan's atmospheric chemistry at low temperature, to produce aerosols representative of the early stages of Titan's aerosol formation. In the THS, the chemistry is simulated by plasma in the stream of a supersonic expansion. With this unique design, the gas is jet-cooled to Titan-like temperature (~150K) before inducing the chemistry by plasma, and remains at low temperature in the plasma discharge (~200K). Because of the pulsed nature of the plasma, the residence time of the gas in the discharge is only a few microseconds, which leads to a truncated chemistry and allows for the study of the first and intermediate steps of the chemistry. Different N2-CH4-based gas mixtures can be injected in the plasma, with or without the addition of heavier precursors present as trace elements on Titan, in order to monitor the evolution of the chemical growth. Both the gas phase and solid phase products resulting from the plasma-induced chemistry can be monitored and analyzed using a combination of complementary in situ and ex situ diagnostics. In a recently published study, a mass spectrometry analysis of the gas phase has demonstrated that the THS is a unique tool to probe the first and intermediate steps of Titan's atmospheric chemistry at Titan-like temperature. In particular, the mass spectra obtained in a N2-CH4-C2H2-C6H6 mixture are relevant for comparison to Cassini's CAPS-IBS instrument. Here we present the results of a complementary study of the solid phase. Scanning Electron Microscopy images have shown that aggregates produced in N2-CH4-C2H2-C6H6 mixtures are much larger (up to 5 μm in diameter) than those produced in N2-CH4 mixtures (0.1-0.5 μm). Direct Analysis in Real Time mass spectrometry (DART-MS) combined with Collision Induced Dissociation (CID) have detected the presence of aminoacetonitrile, a precursor of glycine, in the THS

  9. Osmotic dehydration of fish: principal component analysis

    Directory of Open Access Journals (Sweden)

    Lončar Biljana Lj.

    2014-01-01

    Full Text Available Osmotic treatment of the fish Carassius gibelio was studied in two osmotic solutions: ternary aqueous solution - S1, and sugar beet molasses - S2, at three solution temperatures of 10, 20 and 30oC, at atmospheric pressure. The aim was to examine the influence of type and concentration of the used hypertonic agent, temperature and immersion time on the water loss, solid gain, dry mater content, aw and content of minerals (Na, K, Ca and Mg. S2 solution has proven to be the best option according to all output variables.[ Projekat Ministarstva nauke Republike Srbije, br. TR 31055

  10. Dehydration of bacteriophages in electrospun nanofibers: effect of excipients in polymeric solutions

    Science.gov (United States)

    Koo, Charmaine K. W.; Senecal, Kris; Senecal, Andre; Nugen, Sam R.

    2016-12-01

    Bacteriophages are viruses capable of infecting and lysing target bacterial cells; as such they have potential applications in agriculture for decontamination of foods, food contact surfaces and food rinse water. Although bacteriophages can retain infectivity long-term using lyophilized storage, the process of freeze-drying can be time consuming and expensive. In this study, electrospinning was used for dehydrating bacteriophages in polyvinylpyrrolidone polymer solutions with addition of excipients (sodium chloride, magnesium sulfate, Tris-HCl, sucrose) in deionized water. The high voltage dehydration reduced the infectivity of bacteriophages following electrospinning, with the damaging effect abated with addition of storage media (SM) buffer and sucrose. SM buffer and sucrose also provided the most protection over extended storage (8 weeks; 20 °C 1% relative humidity) by mitigating environmental effects on the dried bacteriophages. Magnesium sulfate however provided the least protection due to coagulation effects of the ion, which can disrupt the native conformation of the bacteriophage protein coat. Storage temperatures (20 °C, 4 °C and -20 °C 1% relative humidity) had a minimal effect while relative humidity had substantial effect on the infectivity of bacteriophages. Nanofibers stored in higher relative humidity (33% and 75%) underwent considerable damage due to extensive water absorption and disruption of the fibers. Overall, following storage of nanofiber mats for eight weeks at ambient temperatures, high infective phage concentrations (106-107 PFU ml-1) were retained. Therefore, this study provided valuable insights on preservation and dehydration of bacteriophages by electrospinning in comparison to freeze drying and liquid storage, and the influence of excipients on the viability of bacteriophages.

  11. Survival and growth of epidemically successful and nonsuccessful Salmonella enterica clones after freezing and dehydration.

    Science.gov (United States)

    Müller, Karoline; Aabo, Søren; Birk, Tina; Mordhorst, Hanne; Bjarnadóttir, Björg; Agersø, Yvonne

    2012-03-01

    The spread of epidemically successful nontyphoidal Salmonella clones has been suggested as the most important cause of salmonellosis in industrialized countries. Factors leading to the emergence of success clones are largely unknown, but their ability to survive and grow after physical stress may contribute. During epidemiological studies, a mathematical model was developed that allowed estimation of a factor (q) accounting for the relative ability of Salmonella serovars with different antimicrobial resistances to survive in the food chain and cause human disease. Based on this q-factor, 26 Salmonella isolates were characterized as successful or nonsuccessful. We studied the survival and growth of stationary- and exponential-phase cells of these isolates after freezing for up to 336 days in minced meat. We also investigated survival and growth after dehydration at 10°C and 82% relative humidity (RH) and 25°C and 49% RH for 112 days. Stationary-phase cells were reduced by less than 1 log unit during 1 year of freezing, and growth was initiated with an average lag phase of 1.7 h. Survival was lower in exponentialphase cells, but lag phases tended to be shorter. High humidity and low temperature were less harmful to Salmonella than were low humidity and high temperature. Tolerance to adverse conditions was highest for Salmonella Infantis and one Salmonella Typhimurium U292 isolate and lowest for Salmonella Derby and one Salmonella Typhimurium DT170 isolate. Dehydration, in contrast to freezing, was differently tolerated by the Salmonella strains in this study, but tolerance to freezing and dehydration does not appear to contribute to the emergence of successful Salmonella clones.

  12. Degradation and contamination of perfluorinated sulfonic acid membrane due to swelling-dehydration cycles

    DEFF Research Database (Denmark)

    Andersen, Shuang Ma; Morgen, Per; Skou, Eivind Morten

    Formation of sulfonic anhydride S-O-S (from the condensation of sulfonic acids) was known one of the important degradation mechanisms [i] for Nafion membrane under hydrothermal aging condition, which is especially critical for hydrogen fuel cells. Similar mechanism would also have be desirable...... to the membrane degradation in direct methanol fuel cells (DMFCs), where liquid water has direct contact with the electrolyte. An ex-situ experiment was established with swelling-dehydration cycles on the membrane. However, formation of sulfonic anhydride was not detected during the entire treatment; instead...

  13. Development of a stabilized low temperature infrared absorption cell for use in low temperature and collisional cooling experiments.

    Science.gov (United States)

    Valentin, A; Henry, A; Claveau, C; Camy-Peyret, C; Hurtmans, D; Mantz, A W

    2004-12-01

    We have constructed a stabilized low temperature infrared absorption cell cooled by an open cycle refrigerator, which can run with liquid nitrogen from 250 to 80K or with liquid helium from 80K to a few kelvin. Several CO infrared spectra were recorded at low temperature using a tunable diode laser spectrometer. These spectra were analyzed taking into account the detailed effects of collisions on the line profile when the pressure increases. We also recorded spectra at very low pressure to accurately model the diode laser emission. Spectra of the R(2) line in the fundamental band of 13CO cooled by collisions with helium buffer gas at 10.5K and at pressures near 1 Torr have been recorded. The He-pressure broadening parameter (gamma(0) = 0.3 cm(-1) atm(-1)) has been derived from the simultaneous analysis of four spectra at different pressures.

  14. Modeling short wave radiation and ground surface temperature: a validation experiment in the Western Alps

    Science.gov (United States)

    Pogliotti, P.; Cremonese, E.; Dallamico, M.; Gruber, S.; Migliavacca, M.; Morra di Cella, U.

    2009-12-01

    Permafrost distribution in high-mountain areas is influenced by topography (micro-climate) and high variability of ground covers conditions. Its monitoring is very difficult due to logistical problems like accessibility, costs, weather conditions and reliability of instrumentation. For these reasons physically-based modeling of surface rock/ground temperatures (GST) is fundamental for the study of mountain permafrost dynamics. With this awareness a 1D version of GEOtop model (www.geotop.org) is tested in several high-mountain sites and its accuracy to reproduce GST and incoming short wave radiation (SWin) is evaluated using independent field measurements. In order to describe the influence of topography, both flat and near-vertical sites with different aspects are considered. Since the validation of SWin is difficult on steep rock faces (due to the lack of direct measures) and validation of GST is difficult on flat sites (due to the presence of snow) the two parameters are validated as independent experiments: SWin only on flat morphologies, GST only on the steep ones. The main purpose is to investigate the effect of: (i) distance between driving meteo station location and simulation point location, (ii) cloudiness, (iii) simulation point aspect, (iv) winter/summer period. The temporal duration of model runs is variable from 3 years for the SWin experiment to 8 years for the validation of GST. The model parameterization is constant and tuned for a common massive bedrock of crystalline rock like granite. Ground temperature profile is not initialized because rock temperature is measured at only 10cm depth. A set of 9 performance measures is used for comparing model predictions and observations (including: fractional mean bias (FB), coefficient of residual mass (CMR), mean absolute error (MAE), modelling efficiency (ME), coefficient of determination (R2)). Results are very encouraging. For both experiments the distance (Km) between location of the driving meteo

  15. Acoustic emission analysis coupled with thermogravimetric experiments dedicated to high temperature corrosion studies on metallic alloys

    Energy Technology Data Exchange (ETDEWEB)

    Serris, Eric; Al Haj, Omar; Peres, Veronique; Cournil, Michel [Ecole Nationale Superieure des Mines de Saint-Etienne (France); Kittel, Jean; Grosjean, Francois; Ropital, Francois [IFP Energies nouvelles, BP3 rond-point de l' echangeur de Solaize (France)

    2014-11-01

    High temperature corrosion of metallic alloys (like iron, nickel, zirconium alloys) can damage equipment of many industrial fields (refinery, petrochemical, nuclear..). Acoustic emission (AE) is an interesting method owing to its sensitivity and its non-destructive aspect to quantify the level of damage in use of these alloys under various environmental conditions. High temperature corrosive phenomena create stresses in the materials; the relaxation by cracks of these stresses can be recorded and analyzed using the AE system. The goal of our study is to establish an acoustic signals database which assigns the acoustic signals to the specific corrosion phenomena. For this purpose, thermogravimetric analysis (TGA) is coupled with acoustic emission (AE) devices. The oxidation of a zirconium alloy, zircaloy-4, is first studied using thermogravimetric experiment coupled to acoustic emission analysis at 900 C. An inward zirconium oxide scale, preliminary dense, then porous, grow during the isothermal isobaric step. The kinetic rate increases significantly after a kinetic transition (breakaway). This acceleration occurs with an increase of acoustic emission activity. Most of the acoustic emission bursts are recorded after the kinetic transition. Acoustic emission signals are also observed during the cooling of the sample. AE numerical treatments (using wavelet transform) completed by SEM microscopy characterizations allows us to distinguish the different populations of cracks. Metal dusting represents also a severe form of corrosive degradation of metal alloy. Iron metal dusting corrosion is studied by AE coupled with TGA at 650 C under C{sub 4}H{sub 10} + H{sub 2} + He atmosphere. Acoustic emission signals are detected after a significant increase of the sample mass.

  16. Increased temperatures negatively affect Juniperus communis seeds: evidence from transplant experiments along a latitudinal gradient.

    Science.gov (United States)

    Gruwez, R; De Frenne, P; Vander Mijnsbrugge, K; Vangansbeke, P; Verheyen, K

    2016-05-01

    With a distribution range that covers most of the Northern hemisphere, common juniper (Juniperus communis) has one of the largest ranges of all vascular plant species. In several regions in Europe, however, populations are decreasing in size and number due to failing recruitment. One of the main causes for this failure is low seed viability. Observational evidence suggests that this is partly induced by climate warming, but our mechanistic understanding of this effect remains incomplete. Here, we experimentally assess the influence of temperature on two key developmental phases during sexual reproduction, i.e. gametogenesis and fertilisation (seed phase two, SP2) and embryo development (seed phase three, SP3). Along a latitudinal gradient from southern France to central Sweden, we installed a transplant experiment with shrubs originating from Belgium, a region with unusually low juniper seed viability. Seeds of both seed phases were sampled during three consecutive years, and seed viability assessed. Warming temperatures negatively affected the seed viability of both SP2 and SP3 seeds along the latitudinal gradient. Interestingly, the effect on embryo development (SP3) only occurred in the third year, i.e. when the gametogenesis and fertilisation also took place in warmer conditions. We found strong indications that this negative influence mostly acts via disrupting growth of the pollen tube, the development of the female gametophyte and fertilisation (SP2). This, in turn, can lead to failing embryo development, for example, due to nutritional problems. Our results confirm that climate warming can negatively affect seed viability of juniper. © 2015 German Botanical Society and The Royal Botanical Society of the Netherlands.

  17. Use of clinoptilolite in ethanol dehydration

    OpenAIRE

    Tıhmınlıoğlu, Funda; Ülkü, Semra

    1996-01-01

    Clinoptilolite-type natural zeolite, which exists in various regions of Turkey, has been experimentally studied. For the ethanol-water-local clinoptilolite system, uptake and breakthrough curves were determined under a nitrogen gas atmosphere. In adsorption kinetics and adsorption equilibrium studies, the effects of particle size, temperature and, amount of zeolite on the uptake rate have been investigated. The breakthrough curves for four different flow rates of ethanol and three different b...

  18. Dehydration of fructose to obtain hydroxymethylfurfural

    OpenAIRE

    Garrido Schaeffer, A.; Departamento Académico de Química Orgánica, FQIQ, Universidad Nacional Mayor de San Marcos Lima, Perú; Linares F., T.; Departamento Académico de Operaciones Unitarias, FQIQ Universidad Nacional Mayor de San Marcos Lima, Perú; Otiniano C., M.; Departamento Académico de Operaciones Unitarias, FQIQ Universidad Nacional Mayor de San Marcos Lima, Perú; Armijo C., J.; Departamento Académico de Operaciones Unitarias, FQIQ Universidad Nacional Mayor de San Marcos Lima, Perú; Ugarte T., N.

    2014-01-01

    The objective of this work is the transformation of fructose to 4-hydroxymethylfurfural by a dehydratation process using the 4-toluenesulfonic acid as catalyst . The reaction was carried out using solutions of fructose in water and fructose in water-acetone (50% volume) in a batch reactor at temperatures of 372 K and 348 K respectively. The yield reached a maximum of 16% to hydroxymethylfurfural, an intermediate for obtaining fuel furan. El objetivo del presente trabajo es la transformació...

  19. Dehydration of fructose to obtain hydroxymethylfurfural

    OpenAIRE

    Garrido Schaeffer, A.; Departamento Académico de Química Orgánica, FQIQ, Universidad Nacional Mayor de San Marcos Lima, Perú; Linares F., T.; Departamento Académico de Operaciones Unitarias, FQIQ Universidad Nacional Mayor de San Marcos Lima, Perú; Otiniano C., M.; Departamento Académico de Operaciones Unitarias, FQIQ Universidad Nacional Mayor de San Marcos Lima, Perú; Armijo C., J.; Departamento Académico de Operaciones Unitarias, FQIQ, Universidad Nacional Mayor de San Marcos Lima, Perú; Ugarte T., N.

    2014-01-01

    The objective of this work is the transformation of fructose to 4-hydroxymethylfurfural by a dehydratation process using the 4-toluenesulfonic acid as catalyst . The reaction was carried out using solutions of fructose in water and fructose in water-acetone (50% volume) in a batch reactor at temperatures of 372 K and 348 K respectively. The yield reached a maximum of 16% to hydroxymethylfurfural, an intermediate for obtaining fuel furan. El objetivo del presente trabajo es la transformació...

  20. Structural ordering of disordered ligand-binding loops of biotin protein ligase into active conformations as a consequence of dehydration.

    Directory of Open Access Journals (Sweden)

    Vibha Gupta

    Full Text Available Mycobacterium tuberculosis (Mtb, a dreaded pathogen, has a unique cell envelope composed of high fatty acid content that plays a crucial role in its pathogenesis. Acetyl Coenzyme A Carboxylase (ACC, an important enzyme that catalyzes the first reaction of fatty acid biosynthesis, is biotinylated by biotin acetyl-CoA carboxylase ligase (BirA. The ligand-binding loops in all known apo BirAs to date are disordered and attain an ordered structure only after undergoing a conformational change upon ligand-binding. Here, we report that dehydration of Mtb-BirA crystals traps both the apo and active conformations in its asymmetric unit, and for the first time provides structural evidence of such transformation. Recombinant Mtb-BirA was crystallized at room temperature, and diffraction data was collected at 295 K as well as at 120 K. Transfer of crystals to paraffin and paratone-N oil (cryoprotectants prior to flash-freezing induced lattice shrinkage and enhancement in the resolution of the X-ray diffraction data. Intriguingly, the crystal lattice rearrangement due to shrinkage in the dehydrated Mtb-BirA crystals ensued structural order of otherwise flexible ligand-binding loops L4 and L8 in apo BirA. In addition, crystal dehydration resulted in a shift of approximately 3.5 A in the flexible loop L6, a proline-rich loop unique to Mtb complex as well as around the L11 region. The shift in loop L11 in the C-terminal domain on dehydration emulates the action responsible for the complex formation with its protein ligand biotin carboxyl carrier protein (BCCP domain of ACCA3. This is contrary to the involvement of loop L14 observed in Pyrococcus horikoshii BirA-BCCP complex. Another interesting feature that emerges from this dehydrated structure is that the two subunits A and B, though related by a noncrystallographic twofold symmetry, assemble into an asymmetric dimer representing the ligand-bound and ligand-free states of the protein, respectively. In

  1. Parameterizing Aggregation Rates: Results of cold temperature ice-ash hydrometeor experiments

    Science.gov (United States)

    Courtland, L. M.; Dufek, J.; Mendez, J. S.; McAdams, J.

    2014-12-01

    Recent advances in the study of tephra aggregation have indicated that (i) far-field effects of tephra sedimentation are not adequately resolved without accounting for aggregation processes that preferentially remove the fine ash fraction of volcanic ejecta from the atmosphere as constituent pieces of larger particles, and (ii) the environmental conditions (e.g. humidity, temperature) prevalent in volcanic plumes may significantly alter the types of aggregation processes at work in different regions of the volcanic plume. The current research extends these findings to explore the role of ice-ash hydrometeor aggregation in various plume environments. Laboratory experiments utilizing an ice nucleation chamber allow us to parameterize tephra aggregation rates under the cold (0 to -50 C) conditions prevalent in the upper regions of volcanic plumes. We consider the interaction of ice-coated tephra of variable thickness grown in a controlled environment. The ice-ash hydrometers interact collisionally and the interaction is recorded by a number of instruments, including high speed video to determine if aggregation occurs. The electric charge on individual particles is examined before and after collision to examine the role of electrostatics in the aggregation process and to examine the charge exchange process. We are able to examine how sticking efficiency is related to both the relative abundance of ice on a particle as well as to the magnitude of the charge carried by the hydrometeor. We here present preliminary results of these experiments, the first to constrain aggregation efficiency of ice-ash hydrometeors, a parameter that will allow tephra dispersion models to use near-real-time meteorological data to better forecast particle residence time in the atmosphere.

  2. Investigating Titan's Atmospheric Chemistry at Low Temperature with the Titan Haze Simulation Experiment

    Science.gov (United States)

    Sciamma-O'Brien, E. M.; Salama, F.

    2012-12-01

    Titan, Saturn's largest satellite, possesses a dense atmosphere (1.5 bar at the surface) composed mainly of N2 and CH4. The solar radiation and electron bombardment from Saturn's magnetosphere induces a complex organic chemistry between these two constituents leading to the production of more complex molecules and subsequently to solid aerosols. These aerosols in suspension in the atmosphere form the haze layers giving Titan its characteristic orange color. Since 2004, the instruments onboard the Cassini orbiter have produced large amounts of observational data, unraveling a chemistry much more complex than what was first expected, particularly in Titan's upper atmosphere. Neutral, positively and negatively charged heavy molecules have been detected in the ionosphere of Titan, including benzene (C6H6) and toluene (C6H5CH3). The presence of these critical precursors of polycyclic aromatic hydrocarbon (PAH) compounds suggests that PAHs might play a role in the production of Titan's aerosols. The aim of the Titan Haze Simulation (THS) experiment, developed at the NASA Ames COSmIC facility, is to study the chemical pathways that link the simple molecules resulting from the first steps of the N2-CH4 chemistry to benzene, and to PAHs and nitrogen-containing PAHs (PANHs) as precursors to the production of solid aerosols. In the THS experiment, Titan's atmospheric chemistry is simulated by plasma in the stream of a supersonic expansion. With this unique design, the gas mixture is cooled to Titan-like temperature (~150K) before inducing the chemistry by plasma discharge. Due to the short residence time of the gas in the plasma discharge, the THS experiment can be used to probe the first and intermediate steps of Titan's chemistry by injecting different gas mixtures in the plasma. The products of the chemistry are detected and studied using two complementary techniques: Cavity Ring Down Spectroscopy and Time-Of-Flight Mass Spectrometry. Thin tholin deposits are also produced

  3. Accumulation of acid sites on natural clinoptilolite under recurring dehydration

    Science.gov (United States)

    Moroz, N. K.; Afanassyev, I. S.; Paukshtis, E. A.; Valueva, G. P.

    A new 1H NMR approach was applied to study the influence of recurring dehydration on the acidity of a natural Ca-rich zeolite clinoptilolite. It has been found that thermal cycling progressively increases the rate of the proton exchange between water molecules in the rehydrated state. The observed effect is interpreted as a result of the irreversible accumulation of specific structural defects represented by Brønsted acid sites: each dehydration at 720 K adds to the acid sites in an amount of the order of 10-3 per unit cell. The number of these defects, detected by NMR in hydrated mineral, is in reasonable agreement with their amount estimated for the dehydrated state with an IR-spectroscopy CO-probe method. A comparison of the results obtained for two distinct zeolite samples shows that the Ca2+ ions are of first importance in the dehydration-induced formation of the active acid sites. The barrier for the proton-transfer reaction between the acid sites and H2O molecules in hydrated clinoptilolite is found to be 46 kJ mol-1, which is not too different from the value of 54 kJ mol-1 reported recently for natural chabazite.

  4. Sorbitol dehydration into isosorbide in a molten salt hydrate medium

    NARCIS (Netherlands)

    Li, J.; Spina, A.; Moulijn, J.A.; Makkee, M.

    2013-01-01

    The sorbitol conversion in a molten salt hydrate medium (ZnCl2; 70 wt% in water) was studied. Dehydration is the main reaction, initially 1,4- and 3,6-anhydrosorbitol are the main products that are subsequently converted into isosorbide; two other anhydrohexitols, (1,5- and 2,5-), formed are in less

  5. Kinetics of xylose dehydration into furfural in acetic acid

    Institute of Scientific and Technical Information of China (English)

    Zhou Chen; Weijiang Zhang; Jiao Xu; Pingli Li

    2015-01-01

    In this paper kinetics of xylose dehydration into furfural using acetic acid as catalyst was studied comprehensively and systematical y. The reaction order of both furfural and xylose dehydration was determined and the reaction activation energy was obtalned by nonlinear regression. The effect of acetic acid concentration was also investi-gated. Reaction rate constants were galned. Reaction rate constant of xylose dehydration is k1 ¼ 4:189 . 1010 ½A.0:1676 exp −108:6.1000RT . ., reaction rate constant of furfural degradation is k2 ¼ 1:271 . 104½A.0:1375 exp−63:413.1000RT . and reaction rate constant of condensation reaction is k3 ¼ 3:4051 . 1010½A.0:1676 exp−104:99.1000RT .. Based on this, the kinetics equation of xylose dehydration into furfural in acetic acid was set up according to theory of Dunlop and Furfural generating rate equation is dd½F.t ¼ k1½X.0e−k1t−k2½F.−k3½X.0e−k1t½F.. © 2015 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. Al rights reserved.

  6. Reference chart for relative weight change to detect hypernatraemic dehydration

    NARCIS (Netherlands)

    Dommelen, P. van; Wouwe, J.P. van; Breuning-Boers, J.M.; Buuren, S. van; Verkerk, P.H.

    2007-01-01

    Objective: The validity of the rule of thumb that infants may have a weight loss of 10% in the first days after birth is unknown. We assessed the validity of this and other rules to detect breast-fed infants with hypernatraemic dehydration. Design: A reference chart for relative weight change was co

  7. Microfluidic Droplet Dehydration for Concentrating Processes in Biomolecules

    Science.gov (United States)

    Anna, Shelley

    2014-03-01

    Droplets in microfluidic devices have proven useful as picoliter reactors for biochemical processing operations such as polymerase chain reaction, protein crystallization, and the study of enzyme kinetics. Although droplets are typically considered to be self-contained, constant volume reactors, there can be significant transport between the dispersed and continuous phases depending on solubility and other factors. In the present talk, we show that water droplets trapped within a microfluidic device for tens of hours slowly dehydrate, concentrating the contents encapsulated within. We use this slow dehydration along with control of the initial droplet composition to influence gellation, crystallization, and phase separation processes. By examining these concentrating processes in many trapped drops at once we gain insight into the stochastic nature of the events. In one example, we show that dehydration rate impacts the probability of forming a specific crystal habit in a crystallizing amino acid. In another example, we phase separate a common aqueous two-phase system within droplets and use the ensuing two phases to separate DNA from an initial mixture. We further influence wetting conditions between the two aqueous polymer phases and the continuous oil, promoting complete de-wetting and physical separation of the polymer phases. Thus, controlled dehydration of droplets allows for concentration, separation, and purification of important biomolecules on a chip.

  8. Cranial ultrasound and CT findings in infants with hypernatremic dehydration

    Energy Technology Data Exchange (ETDEWEB)

    Han, Bokyung K. [Department of Pediatric Radiology, Samsung Medical Centre, 50 Irwon-Dong, Kangnam-Ku, Seoul 135-230 (Korea, Republic of); Lee, Munhyang [Department of Pediatric Radiology, Samsung Medical Centre, 50 Irwon-Dong, Kangnam-Ku, Seoul 135-230 (Korea, Republic of); Yoon, Hye Kyung [Department of Pediatric Radiology, Samsung Medical Centre, 50 Irwon-Dong, Kangnam-Ku, Seoul 135-230 (Korea, Republic of)

    1997-09-01

    We present two newborn infants with hypernatremic dehydration with central nervous system (CNS) involvement. Both patients showed similar imaging findings, demonstrating generalized brain parenchymal abnormality and multifocal areas of hemorrhage or hemorrhagic infarction. These findings are compatible with previously described CNS pathologic findings in hypernatremia. (orig.). With 2 figs.

  9. Carbon-based building blocks for alcohol dehydration

    DEFF Research Database (Denmark)

    Boffa, Vittorio; Mallon, Peter E.; Magnacca, Giuliana

    A biopolymer (HAL), extracted from organic compost with yield ~20%, was used to fabricate composite HAL-graphene oxide (GO) membranes. Upon thermal stabilization, HAL brings high disorder in the membrane structure, thus increasing water permeability. This feature together with the good water/etha....../ethanol perm-selectivity make GO-HAL membranes promising devices for alcohol dehydration....

  10. Science Study Aids 1: Dehydration for Food Preservation.

    Science.gov (United States)

    Boeschen, John; And Others

    This publication is the first of a series of seven supplementary investigative materials for use in secondary science classes providing up-to-date research-related investigations. This unit is structured for grades 9 through 12. It is concerned with the osmatic dehydration of fruits. The guide provides students with information about food…

  11. KNaY-zeolite catalyzed dehydration of methyl lactate

    Institute of Scientific and Technical Information of China (English)

    Hai Feng Shi; Yao Chi Hu; Yang Wang; He Huang

    2007-01-01

    A promising catalyst, KNaY was prepared by an ion exchange method with aqueous potassium chloride solution. Compared with NaY, KNaY was an effective catalyst for the dehydration of methyl lactate to methyl acrylate. Under the optimized conditions,an improved yield of 37.9 mol% was achieved.

  12. Creatine Use and Exercise Heat Tolerance in Dehydrated Men

    OpenAIRE

    Watson, Greig; Casa, Douglas J.; Fiala, Kelly A; Hile, Amy; Roti, Melissa W; Healey, Julie C; Armstrong, Lawrence E; Maresh, Carl M.

    2006-01-01

    Context: Creatine monohydrate (CrM) use is highly prevalent in team sports (eg, football, lacrosse, ice hockey) and by athletes at the high school, college, professional, and recreational levels. Concerns have been raised about whether creatine use is associated with increased cramping, muscle injury, heat intolerance, and risk of dehydration.

  13. Controlled dehydration of a ruthenium complex-DNA crystal induces reversible DNA kinking.

    Science.gov (United States)

    Hall, James P; Sanchez-Weatherby, Juan; Alberti, Cora; Quimper, Caroline Hurtado; O'Sullivan, Kyra; Brazier, John A; Winter, Graeme; Sorensen, Thomas; Kelly, John M; Cardin, David J; Cardin, Christine J

    2014-12-17

    Hydration-dependent DNA deformation has been known since Rosalind Franklin recognized that the relative humidity of the sample had to be maintained to observe a single conformation in DNA fiber diffraction. We now report for the first time the crystal structure, at the atomic level, of a dehydrated form of a DNA duplex and demonstrate the reversible interconversion to the hydrated form at room temperature. This system, containing d(TCGGCGCCGA) in the presence of Λ-[Ru(TAP)2(dppz)](2+) (TAP = 1,4,5,8-tetraazaphenanthrene, dppz = dipyrido[3,2-a:2',3'-c]phenazine), undergoes a partial transition from an A/B hybrid to the A-DNA conformation, at 84-79% relative humidity. This is accompanied by an increase in kink at the central step from 22° to 51°, with a large movement of the terminal bases forming the intercalation site. This transition is reversible on rehydration. Seven data sets, collected from one crystal at room temperature, show the consequences of dehydration at near-atomic resolution. This result highlights that crystals, traditionally thought of as static systems, are still dynamic and therefore can be the subject of further experimentation.

  14. [Salmonella destruction by heating during the customary preparation of dehydrated food products (author's transl)].

    Science.gov (United States)

    Ruschke, R

    1980-01-01

    Defined number of S. Senftenberg W 775 (between 300 000 and 16 000 000 colony forming units in relation to 1 ml of the ready-to-serve-product) were added to 21 different dehydrated ready-to-eat-meals (no baby and junior food) cutomary in trade, of which 11 were cooked for a certain period of time, while 10 were prepared with boiling water only. No surviving salmonellae were found in any of the products ready for consumption. All samples were subject to temperature control. In this paper 6 examples are given to show temperature control during the phase of preparation. More than 1800 examinations performed by us on comparable products revealed no salmonellae in samples between 20 and 50 g. However, in view of the ubiquity of salmonaellae today, incidental positive findings in dehydrated products of this type cannot be excluded; but such findings would not defintely mean degredation of the product. If properly prepared, the food concerned is not dangerous to the consumer.

  15. Catalytic performance of hierarchical H-ZSM-5/MCM-41 for methanol dehydration to dimethyl ether

    Institute of Scientific and Technical Information of China (English)

    Yu; Sang; Hongxiao; Liu; Shichao; He; Hansheng; Li; Qingze; Jiao; Qin; Wu; Kening; Sun

    2013-01-01

    Micro-mesoporous composite molecular sieves H-ZSM-5/MCM-41 were prepared by the hydrothermal technique with alkali-treated H-ZSM-5zeolite as the source and characterized by scanning electron microscopy,transmission electron microscopy,energy dispersive spectroscopy,X-ray diffraction,N2 adsorption-desorption measurement and NH3 temperature-programmed desorption.The catalytic performances for the methanol dehydration to dimethyl ether over H-ZSM-5/MCM-41 were evaluated.Among these catalysts,H-ZSM-5/MCM-41 prepared with NaOH dosage (nNa/nSi) varying from 0.4 to 0.47 presented excellent catalytic activity with more than 80%methanol conversion and 100%dimethyl ether selectivity in a wide temperature range of 170—300℃,and H-ZSM-5/MCM-41 prepared with nNa/nSi=0.47 showed constant methanol conversion of about 88.7%,100% dimethyl ether selectivity and excellent lifetime at 220℃.The excellent catalytic performances were due to the highly active and uniform acidic sites and the hierarchical porosity in the micro-mesoporous composite molecular sieves.The catalytic mechanism of H-ZSM-5/MCM-41 for the methanol dehydration to dimethyl ether process was also discussed.

  16. Earth's core-mantle boundary - Results of experiments at high pressures and temperatures

    Science.gov (United States)

    Knittle, Elise; Jeanloz, Raymond

    1991-01-01

    Laboratory experiments document that liquid iron reacts chemically with silicates at high pressures (above 2.4 x 10 to the 10th Pa) and temperatures. In particular, (Mg,Fe)SiO3 perovskite, the most abundant mineral of earth's lower mantle, is expected to react with liquid iron to produce metallic alloys (FeO and FeSi) and nonmetallic silicates (SiO2 stishovite and MgSiO3 perovskite) at the pressures of the core-mantle boundary, 14 x 10 to the 10th Pa. The experimental observations, in conjunction with seismological data, suggest that the lowermost 200 to 300 km of earth's mantle, the D-double-prime layer, may be an extremely heterogeneous region as a result of chemical reactions between the silicate mantle and the liquid iron alloy of earth's core. The combined thermal-chemical-electrical boundary layer resulting from such reactions offers a plausible explanation for the complex behavior of seismic waves near the core-mantle boundary and could influence earth's magnetic field observed at the surface.

  17. Kinetics of Acid-Catalyzed Dehydration of Cyclic Hemiacetals in Organic Aerosol Particles in Equilibrium with Nitric Acid Vapor.

    Science.gov (United States)

    Ranney, April P; Ziemann, Paul J

    2016-04-28

    Previous studies have shown that 1,4-hydroxycarbonyls, which are often major products of the atmospheric oxidation of hydrocarbons, can undergo acid-catalyzed cyclization and dehydration in aerosol particles to form highly reactive unsaturated dihydrofurans. In this study the kinetics of dehydration of cyclic hemiacetals, the rate-limiting step in this process, was investigated in a series of environmental chamber experiments in which secondary organic aerosol (SOA) containing cyclic hemiacetals was formed from the reaction of n-pentadecane with OH radicals in dry air in the presence of HNO3. A particle beam mass spectrometer was used to monitor the formation and dehydration of cyclic hemiacetals in real time, and SOA and HNO3 were quantified in filter samples by gravimetric analysis and ion chromatography. Measured dehydration rate constants increased linearly with increasing concentration of HNO3 in the gas phase and in SOA, corresponding to catalytic rate constants of 0.27 h(-1) ppmv(-1) and 7.0 h(-1) M(-1), respectively. The measured Henry's law constant for partitioning of HNO3 into SOA was 3.7 × 10(4) M atm(-1), ∼25% of the value for dissolution into water, and the acid dissociation constant was estimated to be water. The results indicate that HNO3 was only weakly dissociated in the SOA and that dehydration of cyclic hemiacetals was catalyzed by molecular HNO3 rather than by H(+). The Henry's law constant and kinetics relationships measured here can be used to improve mechanisms and models of SOA formation from the oxidation of hydrocarbons in dry air in the presence of NOx, which are conditions commonly used in laboratory studies. The fate of cyclic hemiacetals in the atmosphere, where the effects of higher relative humidity, organic/aqueous phase separation, and acid catalysis by molecular H2SO4 and/or H(+) are likely to be important, is discussed.

  18. Features of the Treatment for the Syndrome of Dehydration in Infants and Older Children, Newborns: Fundamentals of Parenteral Rehydration

    Directory of Open Access Journals (Sweden)

    V.I. Snisar

    2016-06-01

    Full Text Available In pediatric practice, the syndrome of dehydration is quite common. In children, the most likely cause of the fluid loss is gastroenteritis syndrome and diarrhea of various origins. These causes are often associated with diarrhea and vomiting that results in the loss of water and electrolytes in various proportions. In contrast to the treatment of critical conditions, such as hypovolemic and septic shock, there is no standardized approach to the correction of mild to moderate syndrome of dehydration. The role of oral rehydration in the prehospital and hospital stage is significantly underestimated. This article is a sign of interest in the unification of approaches to the treatment of such conditions, makes it possible to get acquainted with a generalized view of the treatment and prevention of a variety of adverse reactions on the background of oral and/or parenteral rehydration. Our survey reminds the practitioner about the features of dehydration syndrome in children of different age groups, the importance of taking into account the pathogenesis of various types of dehydration during the diagnosis, de­monstrates the importance of knowledge in the field of infusion media in the context of the therapy balanced in terms of the volume and components, as well as considers the target fluid spaces of the body under pathological losses. We investigate the concept of physiological infusion solution on the basis of evidence-based medicine. This review is advisory, it is based both on the national experience in the treatment of the syndrome of dehydration and foreign resources analysis.

  19. Whole transcriptome characterization of the effects of dehydration and rehydration on Cladonia rangiferina, the grey reindeer lichen.

    Science.gov (United States)

    Junttila, Sini; Laiho, Asta; Gyenesei, Attila; Rudd, Stephen

    2013-12-10

    Lichens are symbiotic organisms with a fungal and an algal or a cyanobacterial partner. Lichens inhabit some of the harshest climates on earth and most lichen species are desiccation-tolerant. Lichen desiccation-tolerance has been studied at the biochemical level and through proteomics, but the underlying molecular genetic mechanisms remain largely unexplored. The objective of our study was to examine the effects of dehydration and rehydration on the gene expression of Cladonia rangiferina. Samples of C. rangiferina were collected at several time points during both the dehydration and rehydration process and the gene expression intensities were measured using a custom DNA microarray. Several genes, which were differentially expressed in one or more time points, were identified. The microarray results were validated using qRT-PCR analysis. Enrichment analysis of differentially expressed transcripts was also performed to identify the Gene Ontology terms most associated with the rehydration and dehydration process. Our data identify differential expression patterns for hundreds of genes that are modulated during dehydration and rehydration in Cladonia rangiferina. These dehydration and rehydration events clearly differ from each other at the molecular level and the largest changes to gene expression are observed within minutes following rehydration. Distinct changes are observed during the earliest stage of rehydration and the mechanisms not appear to be shared with the later stages of wetting or with drying. Several of the most differentially expressed genes are similar to genes identified in previous studies that have investigated the molecular mechanisms of other desiccation-tolerant organisms. We present here the first microarray experiment for any lichen species and have for the first time studied the genetic mechanisms behind lichen desiccation-tolerance at the whole transcriptome level.

  20. Survey report on high temperature irradiation experiment programs for new ceramic materials in the HTTR (High Temperature Engineering Test Reactor). 2

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-02-01

    A survey research on status of research activities on new ceramic materials in Japan was carried out under contract between Japan Atomic Energy Research Institute and Atomic Energy Society of Japan. The purpose of the survey is to provide information to prioritize prospective experiments and tests in the HTTR. The HTTR as a high temperature gas cooled reactor has a unique and superior capability to irradiate large-volumed specimen at high temperature up to approximately 800degC. The survey was focused on mainly the activities of functional ceramics and heat resisting ceramics as a kind of structural ceramics. As the result, the report recommends that the irradiation experiment of functional ceramics is feasible to date. (K. Itami)

  1. Improving energy efficiency in the production processes of dehydration smoked and dried fish.

    Directory of Open Access Journals (Sweden)

    Mihail Ershov

    2013-04-01

    Full Text Available The technology of dehydration fish with cyclical periods of drying and relaxation facility dehydration. This technology is aimed at improving the energy efficiency of the processes of dehydration by drying and cold-smoked fish. Relaxation object dehydration is most effective in a period of falling drying rate. The use of the proposed technology can reduce energy costs in the production of dried and smoked products by 8-12% as compared to conventional technology.

  2. Catalytic dehydration of ethanol to ethylene

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Ying; Jin, Zhaosheng; Shen, Wei [SINOPEC Shanghai Research Institute of Petrochemical Technology, Shanghai (China)

    2011-07-01

    The different routes of ethylene production were briefly introduced and the advantage of ethanol to ethylene (ETE) route was explained. Followed by that, the upgraded catalyst applied in this route developed by SINOPEC Shanghai Research Institute of Petrochemical Technology (SRIPT) was introduced together with the development of the ethanol to ethylene process. The core technologies involved in this process development were discussed, such as isothermal fixed-bed reactor, water scrubber and alkaline wash column, two columns of low-temperature separation as well as process heat integration. Furthermore, the performance of one of ethanol industrial plants licensed by SRIPT was reviewed. It is as follows, conversion of ethanol reaches 99% while selectivity of ethylene is over 96% at the reaction temperature of 350{approx}450 C, the liquid hourly space velocity (LHSV)of 0.5{approx}1.0 h{sup -1} and atmosphere pressure. Meanwhile, the catalyst shows its life time of one year. This route is considered not only as an economical and practical process but also as an environmentfriendly path to ethylene production. (orig.)

  3. Response to prey chemical cues by hatchling pine snakes (Pituophis melanoleucus): Effects of incubation temperature and experience.

    Science.gov (United States)

    Burger, J

    1991-06-01

    The ability of hatchling pine snakes (Pituophis melanoleucus) to select and follow or avoid chemical odors of prey (mice,Mus musculus) on a shavings and paper substrate was investigated in Y-maze experiments, as a function of incubation temperature and experience. Incubation temperature affected behavior in the maze, and the maze choices of naive snakes, but not of snakes that had already eaten a mouse. The data indicate that snakes that have eaten, preferentially enter the arm bearing chemical stimuli from mice, whereas those that have not eaten show no preference.

  4. Vapor Phase Dehydration of Glycerol to Acrolein Over SBA-15 Supported Vanadium Substituted Phosphomolybdic Acid Catalyst.

    Science.gov (United States)

    Viswanadham, Balaga; Srikanth, Amirineni; Kumar, Vanama Pavan; Chary, Komandur V R

    2015-07-01

    Vapor phase dehydration of glycerol to acrolein was investigated over heteropolyacid (HPA) catalysts containing vanadium substituted phosphomolybdic acid (H4PMo11VO40) supported on mesoporous SBA-15. A series of HPA catalysts with HPA loadings varying from 10-50 wt% were prepared by impregnation method on SBA-15 support. The catalysts were characterized by X-ray diffraction, Raman spectroscopy, Fourier Transform infrared spectroscopy, temperature-programmed desorption of NH3, pyridine adsorbed FT-IR spectroscopy, scanning electron microscopy, pore size distribution and specific surface area measurements. The nature of acidic sites was examined by pyridine adsorbed FT-IR spectroscopy. XRD results suggest that the active phase containing HPA was highly dispersed at lower loadings on the support. FT-IR and Raman spectra results confirm that the presence of primary Keggin ion structure of HPA on the support and it was not affected during the preparation of catalysts. Pore size distribution results reveal that all the samples show unimodel pore size distribution with well depicted mesoporous structure. NH3-TPD results suggest that the acidity of catalysts increased with increase of HPA loading. The findings of acidity measurements by FT-IR spectra of pyridine adsorption reveals that the catalysts consist both the Brønsted and Lewis acidic sites and the amount of Brønsted acidic sites are increasing with HPA loading. SBA-15 supported vanadium substituted phosphomolybdic acid catalysts are found to be highly active during the dehydration reaction and exhibited 100% conversion of glycerol (10 wt% of glycerol) and the acrolein selectivity was appreciably changed with HPA active phase loading. The catalytic functionalities during glycerol dehydration are well correlated with surface acidity of the catalysts.

  5. Wine bottle colour and oxidative spoilage: whole bottle light exposure experiments under controlled and uncontrolled temperature conditions.

    Science.gov (United States)

    Dias, Daniel A; Clark, Andrew C; Smith, Trevor A; Ghiggino, Kenneth P; Scollary, Geoffrey R

    2013-06-15

    Exposure of a Chardonnay wine to light from a mercury vapour lamp under controlled temperature conditions showed that colour enhancement was dependent on bottle colour. The increase in colouration was Antique Greenlight exposure. Without temperature control, wine colour development was highest in Antique Green and lowest in Flint. This alternate order reflects the ability of the darker bottles to retain heat longer than lighter coloured ones as confirmed by surface temperature decay rates. Specific pigments contributing to the wine colour enhancement in uncontrolled temperature/light exposure experiments could not be identified, although tentative evidence was obtained for the presence of flavan-3-ol based compounds. The different bottle glass surfaces did not influence the rate of loss of dissolved oxygen or oxidation of ascorbic acid. The potential to develop the results obtained in this study to identify markers for light and/or temperature exposure of white wines is discussed.

  6. 40 CFR 407.50 - Applicability; description of the dehydrated potato products subcategory.

    Science.gov (United States)

    2010-07-01

    ... dehydrated potato products subcategory. 407.50 Section 407.50 Protection of Environment ENVIRONMENTAL... PROCESSING POINT SOURCE CATEGORY Dehydrated Potato Products Subcategory § 407.50 Applicability; description of the dehydrated potato products subcategory. The provisions of this subpart are applicable...

  7. Experiments of Brittle-Plastic Transition and Instability Modes of Juyongguan Granite at Different Temperatures and Pressures

    Institute of Scientific and Technical Information of China (English)

    Zhou Yongsheng; Jiang Haikun; He Changrong

    2003-01-01

    Three groups of experiments on brittle-plastic transition and instability modes of granite wereperformed in a triaxial vessel with solid pressure medium at high temperature and highpressure. The results of experiments show that brittle faulting is the major failure mode attemperature < 300℃, but crystal-plastic deformation is dominate at temperature > 800℃, andthere is a transition with increasing temperature from semi-brittle faulting to cataclnstic flowand semi-brittle flow at temperatures of 300 ~ 800℃. So, temperature is the most influentialfactor in brittle-plastic transition of granite and confining pressure is the second factor. Theresults also show that progressive failure of granite occurs at lower pressure or hightemperature where there is crystal plasticity, and sudden instability occurs at room temperatureand high pressure ( > 300MPa) or high temperature and great pressure(550℃600MPa ~ 650℃700MPa), and a broad regime of quasi-sudden instability exists between the T-P condition ofprogressive failure and sudden instability. So, instability modes of granite dependsimnitaneonsly on the pressure and temperature.

  8. Uncertainty Quantification of Calculated Temperatures for the U.S. Capsules in the AGR-2 Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Lybeck, Nancy [Idaho National Lab. (INL), Idaho Falls, ID (United States); Einerson, Jeffrey J. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Pham, Binh T. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Hawkes, Grant L. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-03-01

    A series of Advanced Gas Reactor (AGR) irradiation experiments are being conducted within the Advanced Reactor Technology (ART) Fuel Development and Qualification Program. The main objectives of the fuel experimental campaign are to provide the necessary data on fuel performance to support fuel process development, qualify a fuel design and fabrication process for normal operation and accident conditions, and support development and validation of fuel performance and fission product transport models and codes (PLN-3636). The AGR-2 test was inserted in the B-12 position in the Advanced Test Reactor (ATR) core at Idaho National Laboratory (INL) in June 2010 and successfully completed irradiation in October 2013, resulting in irradiation of the TRISO fuel for 559.2 effective full power days (EFPDs) during approximately 3.3 calendar years. The AGR-2 data, including the irradiation data and calculated results, were qualified and stored in the Nuclear Data Management and Analysis System (NDMAS) (Pham and Einerson 2014). To support the U.S. TRISO fuel performance assessment and to provide data for validation of fuel performance and fission product transport models and codes, the daily as-run thermal analysis has been performed separately on each of four AGR-2 U.S. capsules for the entire irradiation as discussed in (Hawkes 2014). The ABAQUS code’s finite element-based thermal model predicts the daily average volume-average fuel temperature and peak fuel temperature in each capsule. This thermal model involves complex physical mechanisms (e.g., graphite holder and fuel compact shrinkage) and properties (e.g., conductivity and density). Therefore, the thermal model predictions are affected by uncertainty in input parameters and by incomplete knowledge of the underlying physics leading to modeling assumptions. Therefore, alongside with the deterministic predictions from a set of input thermal conditions, information about prediction uncertainty is instrumental for the ART

  9. The Titan Haze Simulation experiment: laboratory simulation of Titan's atmospheric chemistry at low temperature

    Science.gov (United States)

    Sciamma-O'Brien, E.; Contreras, C. S.; Ricketts, C. L.; Salama, F.

    2012-04-01

    In Titan’s atmosphere, a complex organic chemistry between its two main constituents, N2 and CH4, leads to the production of heavy molecules and subsequently to solid organic aerosols. Several instruments onboard Cassini have detected neutral, positively and negatively charged particles and heavy molecules in the ionosphere of Titan[1,2]. In particular, the presence of benzene (C6H6) and toluene (C6H5CH3)[3], which are critical precursors of polycyclic aromatic hydrocarbon (PAH) compounds, suggests that PAHs might play a role in the production of Titan’s aerosols. The Titan Haze Simulation (THS) experiment has been developed at NASA Ames’ Cosmic Simulation facility (COSmIC) to study the chemical pathways that link the simple precursor molecules resulting from the first steps of the N2-CH4 chemistry (C2H2, C2H4, HCN…) to benzene, and to PAHs and nitrogen-containing PAHs (or PANHs) as precursors to the production of solid aerosols. In the THS experiment, Titan’s atmospheric chemistry is simulated by plasma in the stream of a supersonic jet expansion. With this unique design, the gas mixture is cooled to Titan-like temperature (~150K) before inducing the chemistry by plasma discharge. Different gas mixtures containing the first products of Titan’s N2-CH4 chemistry but also much heavier molecules like PAHs or PANHs can be injected to study specific chemical reactions. The products of the chemistry are detected and studied using two complementary techniques: Cavity Ring Down Spectroscopy[4] and Time-Of-Flight Mass Spectrometry[5]. Thin tholin deposits are also produced in the THS experiment and can be analyzed by Gas Chromatography-Mass Spectrometry (GC-MS) and Scanning Electron Microscopy (SEM). We will present the results of ongoing mass spectrometry studies on the THS experiment using different gas mixtures: N2-CH4, N2-C2H2, N2-C2H4, N2-C2H6, N2-C6H6, and similar mixtures with an N2-CH4 (90:10) mixture instead of pure N2, to study specific pathways

  10. [Effect of a dehydrated extract of nopal (Opuntia ficus indica Mill.) on blood glucose].

    Science.gov (United States)

    Frati-Munari, A C; de León, C; Ariza-Andraca, R; Bañales-Ham, M B; López-Ledesma, R; Lozoya, X

    1989-01-01

    To assess if a dehydrated extract of nopal stems retains the effect on glycemia of the entire nopal stems two experiments were performed. A. Six patients with type II diabetes mellitus in fasting condition received 30 capsules containing 10.1 +/- 0.3 g of the extract, and serum glucose levels were measured hourly from 0 to 180 minutes. B. Six healthy volunteers received 30 capsules with the extract followed by 74 g of dextrose orally. Serum glucose measurements were made in a similar fashion. In each experiment a control test with empty capsules was performed. Nopal extract did not reduce fasting glycemia in diabetic subjects. Nevertheless, the extract diminished the increase of serum glucose which followed a dextrose load. Peak serum glucose was 20.3 +/- 18.2 mg/dl (X +/- SD) lower in the test with nopal than in the control one (P less than 0.025). Dehydrated extract of nopal (Opuntia ficus-indica Mill) did not show acute hypoglycemic effect, although could attenuate postprandial hyperglycemia.

  11. Changes in freezing point of blood and milk during dehydration and rehydration in lactating cows

    DEFF Research Database (Denmark)

    Bjerg, M.; Rasmussen, M.D.; Nielsen, Mette Olaf

    2005-01-01

    We studied the influence of short-term changes in water intake in 4 lactating Holstein cows on diurnal fluctuation of packed cell volume (PCV), freezing point of blood (FP blood), freezing point of milk ( FP milk), and the relationship between changes in FP blood and FP milk. The experiment lasted...... 108 h and was divided into 3 periods: 1) control (38 h); 2) dehydration/rehydration with 4 consecutive 12-h sequences: 8 h without water, 0.5-h access to water, 1.5 h without water, and 2-h access to water; and (3) 22 h for reconstitution. Cows were milked at 12-h intervals. Blood was sampled from...... the jugular vein hourly throughout the experiment, and at 0, 15, 30, 60, 90, 120, 150, 180, 210, and 240 min after initiated rehydration following the 8-h dehydration sequences. Intakes of free water and water in feed were recorded every hour. The PCV was negatively affected by water intake within the hour...

  12. Numerical Simulation of an Industrial Absorber for Dehydration of Natural Gas Using Triethylene Glycol

    Directory of Open Access Journals (Sweden)

    Kenneth Kekpugile Dagde

    2014-01-01

    Full Text Available Models of an absorber for dehydration of natural gas using triethylene glycol are presented. The models were developed by applying the law of conservation of mass and energy to predict the variation of water content of gas and the temperature of the gas and liquid with time along the packing height. The models were integrated numerically using the finite divided difference scheme and incorporated into the MATLAB code. The results obtained agreed reasonably well with industrial plant data obtained from an SPDC TEG unit in Niger-Delta, Nigeria. Model prediction showed a percentage deviation of 8.65% for gas water content and 3.41% and 9.18% for exit temperature of gas and liquid, respectively.

  13. [Chemical evaluation of morro or jícaro (Crescentia alata) flours prepared by ensilaging and/or dehydration].

    Science.gov (United States)

    Gómez-Brenes, R A; Contreras, I; Braham, J E; Bressani, R

    1980-06-01

    The chemical composition, nutritive value and potential use of the morro fruit (Crescentia alata) has received little attention. The purpose of the present study was: a) to determine appropriate conditions for processing and conservation of the morro fruit without hulls, since a significant part of the production is lost due to inadequate storage conditions, and b) to evaluate, by means of chemical analysis, the whole fruit and its products. For the preparation of dehydrated meals, the content of the fruit was subjected to sun drying and tray drying dehydration with two air temperatures, 60 degrees and 90 degrees C. The method used for the storage of the whole fruit was anaerobic fermentation achieved by ensilaging the fruit in small concrete experimental silos for 90, 145 and 180 days. At the end of each period, the silos were opened. The ensilaged material was of very good appearance and apparently free from unfavorable contaminations; it was dehydrated in tray dryers at an air temperature of 60 degrees C. Independent of processing, the chemical analysis showed the meals to contain on the average 17% crude fat, 11% crude fiber and 18% crude protein. From the amino acid content and using the 1973 FAO/WHO scoring pattern it was found that such flours were limiting in their sulfur amino acid, lysine and threonine content in the order.

  14. Use of dehydrated waste grape skins as a natural additive for producing rosé wines: study of extraction conditions and evolution.

    Science.gov (United States)

    Pedroza, Miguel Angel; Carmona, Manuel; Salinas, Maria Rosario; Zalacain, Amaya

    2011-10-26

    Dehydrated waste grape skins from the juice industry were used as an additive to produce rosé wines. Maceration time, particle size, dosage, alcoholic content, and maceration temperature were first studied in model wine solutions using two different dehydrated waste grape skins. Full factorial experimental designs together with Factor Analysis and Multifactor ANOVA allowed for the evaluation of each parameter according to the composition of color and phenolic and aroma compounds. Higher maceration time favored the extraction of anthocyanins; phenolic compound release was influenced by dosage independent from other factors studied. Rosé wines were produced by direct addition of dehydrated waste grape skins, according to selected parameters in two different white wines, achieving characteristics equivalent to commercial rosé wines. After three months of storage, rosé wine composition was stable.

  15. OSMOTIC DEHYDRATION KINETICS OF GUAVAS IN MALTOSE SOLUTIONS WITH CALCIUM SALT*

    Directory of Open Access Journals (Sweden)

    S. DI S. MASTRANTONIO

    2009-03-01

    Full Text Available

    The osmotic dehydration kinetics of guavas in maltose solutions at 40 and 60ºBrix, with addition of 0, 0.6 and 1.2% of calcium lactate was studied in this paper and the final product quality was evaluated. The experiments were carried out up to 60 hours and samples were taken for analysis at different times to evaluate guavas weight reduction, water loss and sugar gain and to characterize the product according to its texture and color. After 24 hours of process the mass transfer of water and sugar between the osmotic solution and the fruit was negligible, showing that process equilibrium was reached. The increase of sugar concentration in the osmotic solution showed strong influence on the dehydration process, increasing the water loss and reducing sugar gain. The presence of calcium ions in the osmotic solution also influenced the kinetics of mass transfer and showed a strong influence on fruit texture. Higher values of stress and strain at failure were obtained when calcium lactate was employed. The effect of the different osmotic treatments on the color parameters was also investigated and significant changes were observed in the values of chroma C* and hue H* due to sugar concentration and calcium addition.

    KEYWORDS: Osmotic dehydration; kinetics; guava; maltose; calcium lactate.

  16. Artificial neural network and response surface methodology modeling in mass transfer parameters predictions during osmotic dehydration of Carica papaya L.

    Directory of Open Access Journals (Sweden)

    J. Prakash Maran

    2013-09-01

    Full Text Available In this study, a comparative approach was made between artificial neural network (ANN and response surface methodology (RSM to predict the mass transfer parameters of osmotic dehydration of papaya. The effects of process variables such as temperature, osmotic solution concentration and agitation speed on water loss, weight reduction, and solid gain during osmotic dehydration were investigated using a three-level three-factor Box-Behnken experimental design. Same design was utilized to train a feed-forward multilayered perceptron (MLP ANN with back-propagation algorithm. The predictive capabilities of the two methodologies were compared in terms of root mean square error (RMSE, mean absolute error (MAE, standard error of prediction (SEP, model predictive error (MPE, chi square statistic (χ2, and coefficient of determination (R2 based on the validation data set. The results showed that properly trained ANN model is found to be more accurate in prediction as compared to RSM model.

  17. Use of gamma radiation cobalt 60 for disinfestation of Lasioderma serricorne (Fabricius, 1972) (Coleoptera: Anobiidae) in Chamomilla recutita L. and Pimpinela anisum L. dehydrated

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Juliana Nazare; Potenza, Marcos Roberto [Instituto Biologico, Sao Paulo, SP (Brazil). Centro de Pesquisa e Desenvolvimento de Sanidade Vegetal]. E-mail: julianaabc@ig.com.br; Arthur, Valter [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil)]. E-mail: arthur@cena.usp.br

    2008-03-15

    Stores products such a grains, flours, dry fruits and spices are normally infested by pests as beetles (Lasioderma serricorne), mites and moths, depreciating the product visually and promoting its deterioration. To improve the quality of spices, medicinal plants and others foodstuffs there is a need for adequate methods of handling, correct identification of the species, adequate collection and storage. The objective of this work was to determine the dose of gamma radiation for the disinfestation of medicinal and aromatic plants infested by L. serricorne. The plants used in this study were Chamomilla recutita L. and Pimpinela anisum L. in this dehydrated form. The experiment was carried out in the Laboratorio de Inseticidas e Acaricidas from Instituto Biologico/SP, during the months of January and May 2006, and the irradiations were carried out in the Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN/SP, using and experimental Cobalt 60 irradiator, model Gammacell 220. Each treatment consisted of 5 parcels containing 10 g of dehydrated products infested with 20 last instar larvae of L. serricorne, conditioned in plastic 10 x 10 cm containers with small punctures in the cover to allow internal aeration. The substratum previously infested was submitted to increasing doses of gamma radiation: 0: 0.5; 0.75; 1.0; 1.25; 1.50; 1.75; 2.0; 2.25; 2.50 and 2.75 kGy. After irradiation, the samples were kept in a acclimatized room at 27 {+-} 2 deg C of temperature and relative humidity of 70 {+-} 5% and after a 45 days period the number of adults insects emerged was evaluated. The disinfestation dose of gamma radiation for last instar larvae L. serricorne on Chamomilla recutita L. and Pimpinela anisum L. was 2.0 kGy. (author)

  18. Nutrient enrichment modifies temperature-biodiversity relationships in large-scale field experiments

    Science.gov (United States)

    Wang, Jianjun; Pan, Feiyan; Soininen, Janne; Heino, Jani; Shen, Ji

    2016-12-01

    Climate effects and human impacts, that is, nutrient enrichment, simultaneously drive spatial biodiversity patterns. However, there is little consensus about their independent effects on biodiversity. Here we manipulate nutrient enrichment in aquatic microcosms in subtropical and subarctic regions (China and Norway, respectively) to show clear segregation of bacterial species along temperature gradients, and decreasing alpha and gamma diversity toward higher nutrients. The temperature dependence of species richness is greatest at extreme nutrient levels, whereas the nutrient dependence of species richness is strongest at intermediate temperatures. For species turnover rates, temperature effects are strongest at intermediate and two extreme ends of nutrient gradients in subtropical and subarctic regions, respectively. Species turnover rates caused by nutrients do not increase toward higher temperatures. These findings illustrate direct effects of temperature and nutrients on biodiversity, and indirect effects via primary productivity, thus providing insights into how nutrient enrichment could alter biodiversity under future climate scenarios.

  19. HIGH-TEMPERATURE EXAFS EXPERIMENTS ON LIQUID KPB ALLOYS ANALYZED WITH THE REVERSE MONTE-CARLO METHOD

    NARCIS (Netherlands)

    BRAS, W; XU, R; WICKS, JD; VANDERHORST, F; OVERSLUIZEN, M; MCGREEVY, RL; VANDERLUGT, W

    1994-01-01

    A new sample chamber has been designed which allows high temperature Extended X-ray Absorption Fine Structure (EXAFS) experiments on metallic melts which offer a number of special experimental problems: they are highly corrosive, have high vapour pressures and strongly absorb X-rays. The EXAFS spect

  20. Temperature and Electron Density Determination on Laser-Induced Breakdown Spectroscopy (LIBS) Plasmas: A Physical Chemistry Experiment

    Science.gov (United States)

    Najarian, Maya L.; Chinni, Rosemarie C.

    2013-01-01

    This laboratory is designed for physical chemistry students to gain experience using laser-induced breakdown spectroscopy (LIBS) in understanding plasma diagnostics. LIBS uses a high-powered laser that is focused on the sample causing a plasma to form. The emission of this plasma is then spectrally resolved and detected. Temperature and electron…

  1. HIGH-TEMPERATURE EXAFS EXPERIMENTS ON LIQUID KPB ALLOYS ANALYZED WITH THE REVERSE MONTE-CARLO METHOD

    NARCIS (Netherlands)

    BRAS, W; XU, R; WICKS, JD; VANDERHORST, F; OVERSLUIZEN, M; MCGREEVY, RL; VANDERLUGT, W

    1994-01-01

    A new sample chamber has been designed which allows high temperature Extended X-ray Absorption Fine Structure (EXAFS) experiments on metallic melts which offer a number of special experimental problems: they are highly corrosive, have high vapour pressures and strongly absorb X-rays. The EXAFS

  2. Temperature and Electron Density Determination on Laser-Induced Breakdown Spectroscopy (LIBS) Plasmas: A Physical Chemistry Experiment

    Science.gov (United States)

    Najarian, Maya L.; Chinni, Rosemarie C.

    2013-01-01

    This laboratory is designed for physical chemistry students to gain experience using laser-induced breakdown spectroscopy (LIBS) in understanding plasma diagnostics. LIBS uses a high-powered laser that is focused on the sample causing a plasma to form. The emission of this plasma is then spectrally resolved and detected. Temperature and electron…

  3. A Design of Experiments (DOE) approach to optimise temperature measurement accuracy in Solid Oxide Fuel Cell (SOFC)

    Science.gov (United States)

    Barari, F.; Morgan, R.; Barnard, P.

    2014-11-01

    In SOFC, accurately measuring the hot-gas temperature is challenging due to low gas velocity, high wall temperature, complex flow geometries and relatively small pipe diameter. Improper use of low cost thermometry system such as standard Type K thermocouples (TC) may introduce large measurement error. The error could have a negative effect on the thermal management of the SOFC systems and consequential reduction in efficiency. In order to study the factors affecting the accuracy of the temperature measurement system, a mathematical model of a TC inside a pipe was defined and numerically solved. The model calculated the difference between the actual and the measured gas temperature inside the pipe. A statistical Design of Experiment (DOE) approach was applied to the modelling data to compute the interaction effect between variables and investigate the significance of each variable on the measurement errors. In this study a full factorial DOE design with six variables (wall temperature, gas temperature, TC length, TC diameter and TC emissivity) at two levels was carried out. Four different scenarios, two sets of TC length (6 - 10.5 mm and 17 - 22 mm) and two different sets of temperature range (550 - 650 °C and 750 - 850 °C), were proposed. DOE analysis was done for each scenario and results were compared to identify key parameters affecting the accuracy of a particular temperature reading.

  4. First experiment of spectrometric observation of hydroxyl emission and rotational temperature in the mesopause in China

    Institute of Scientific and Technical Information of China (English)

    ZHU YaJun; XU JiYao; YUAN Wei; LIU Xiao

    2012-01-01

    A SpectroMeter of Atmospheric RadiaTion (SMART) was developed and installed at the Xinglong station of the National Astronomical Observatories in Hebei province,China,which was supported by the Meridian Project [ 1].The experimental tests of spectrometric observation of the hydroxyl emission and rotational temperature in China were conducted for the first time on the night of February 23,2011 and the night of April 27,2011,respectively.OH 6-2 band and OH 8-3 band spectra were measured and the rotational temperature was retrieved.Hourly average temperatures (186.82+-6.40) K of OH 8-3 band and (178.07±6.73) K of OH 6-2 band were derived from the spectra observed on the night of February 23,2011.Intensities and rotational temperature against local time were determined by the spectra measured in the whole night of April 27,2011.The rotational temperature was consistent with the spatial average temperature of NRLMSISE00 empirical model at height 83-91 km and the average temperature of TIMED/SABER from April to May of seven years at height 83-91 km,with some discrepancies.The results showed that the new instrument and the retrieval method of the rotational temperature can give reasonable results of the airglow emission of OH and the temperature of mesopause.

  5. Tensile and impact properties of vanadium-base alloys irradiated at low temperatures in the ATR-A1 experiment

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, H.; Nowicki, L.J.; Billone, M.C.; Chung, H.M.; Smith, D.L. [Argonne National Lab., IL (United States)

    1998-03-01

    Subsize tensile and Charpy specimens made from several V-(4-5)Cr-(4-5)Ti alloys were irradiated in the ATR-A1 experiment to study the effects of low-temperature irradiation on mechanical properties. These specimens were contained in lithium-bonded subcapsules and irradiated at temperatures between {approx}200 and 300 C. Peak neutron damage was {approx}4.7 dpa. Postirradiation testing of these specimens has begun. Preliminary results from a limited number of specimens indicate a significant loss of work-hardening capability and dynamic toughness due to the irradiation. These results are consistent with data from previous low-temperature neutron irradiation experiments on these alloys.

  6. Sulfonic acid heterogeneous catalysts for dehydration of C6-monosaccharides to 5-hydroxymethylfurfural in dimethyl sulfoxide

    Institute of Scientific and Technical Information of China (English)

    Gabriel Morales; Juan A.Melero; Marta Paniagua; Jose Iglesias; Blanca Hernández; María Sanz

    2014-01-01

    Sulfonic acid-functionalized heterogeneous catalysts have been evaluated in the catalytic dehydra-tion of C6 monosaccharides into 5-hydroxymethylfurfural (HMF) using dimethyl sulfoxide (DMSO) as solvent. Sulfonic commercial resin Amberlyst-70 was the most active catalyst, which was as-cribed to its higher concentration of sulfonic acid sites as compared with the other catalysts, and it gave 93 mol%yield of HMF from fructose in 1 h. With glucose as the starting material, which is a much more difficult reaction, the reaction conditions (time, temperature, and catalyst loading) were optimized for Amberlyst-70 by a response surface methodology, which gave a maximum HMF yield of 33 mol%at 147°C with 23 wt%catalyst loading based on glucose and 24 h reaction time. DMSO promotes the dehydration of glucose into anhydroglucose, which acts as a reservoir of the substrate to facilitate the production of HMF by reducing side reactions. Catalyst reuse without a regeneration treatment showed a gradual but not very significant decay in catalytic activity.

  7. Three-dimensional numerical modeling of thermal regime and slab dehydration beneath Kanto and Tohoku, Japan

    Science.gov (United States)

    Ji, Yingfeng; Yoshioka, Shoichi; Manea, Vlad Constantin; Manea, Marina; Matsumoto, Takumi

    2017-01-01

    Although the thermal regime of the interface between two overlapping subducting plates, such as those beneath Kanto, Japan, is thought to play an important role in affecting the distribution of interplate and intraslab earthquakes, the estimation of the thermal regime remains challenging to date. We constructed a three-dimensional (3-D) thermal convection model to simulate the subduction of the Pacific plate along the Japan Trench and Izu-Bonin Trench, including the subduction of the Philippine Sea beneath Kanto and investigated the slab thermal regime and slab water contents in this complex tectonic setting. Based on the subduction parameters tested in generic models with two flat oceanic plates, a faster or thicker plate subducting in a more trench-normal direction produces a colder slab thermal regime. The interplate temperature of the cold anomaly beneath offshore Kanto was approximately 300°C colder than that beneath offshore Tohoku at a same depth of 40 km and approximately 600°C colder at a depth of 70 km. The convergence between the two subducting plates produces an asymmetric thermal structure in the slab contact zone beneath Kanto, which is characterized by clustered seismicity in the colder southwestern half. The thermo-dehydration state of the mid-ocean ridge basalt near the upper surface of the subducted Pacific plate controls the interplate seismicity beneath the Kanto-Tohoku region according to the spatial concurrence of the thermo-dehydration and seismicity along the megathrust fault zone of the subducted Pacific plate.

  8. Deeper Subduction Zone Melting Explains Enrichment of Upper Mantle and Resolves Dehydration Paradox

    Science.gov (United States)

    Dixon, Jacqueline; Bindeman, Ilya; Kingsley, Richard

    2017-04-01

    We present new volatile and stable isotope data on oceanic basaltic glasses with a range of enriched compositions. Basalt compositions studied here can be modeled by mixing between depleted mantle and various enriched (EM) and prevalent (PREMA) mantle components. We develop a multi-stage metasomatic and melting model for the origin of the enriched components, extending the subduction factory concept to involve melting of different components at different depths, down to the mantle transition zone (660 km), with slab temperature a key variable. EM components are heterogeneous, ranging from wet and heavy (Arctic Ridges) to dry and light (East Pacific Rise), and are derived from the subducted slab at depths of 150 to 250 km by addition of paradox," refering to the following conundrum. The enriched "prevalent mantle" (PREMA) end-member in mid-oceanic ridge and ocean island basalts requires involvement of a mostly dehydrated slab component to explain trace element ratios and radiogenic isotopic compositions, but a fully hydrated slab component to explain stable isotope compositions. In our model, thermal parameters of slabs control the timing and composition of subduction-derived components. This includes deep release of fluids from subcrustal hydrous phases that may rehydrate previously dehydrated slab, resolving the paradox.

  9. Towards high water permeability in triazine-framework-based microporous membranes for dehydration of ethanol.

    Science.gov (United States)

    Tang, Yu Pan; Wang, Huan; Chung, Tai Shung

    2015-01-01

    The microstructural evolution of a series of triazine framework-based microporous (TFM) membranes under different conditions has been explored in this work. The pristine TFM membrane is in situ fabricated in the course of polymer synthesis via a facile Brønsted-acid-catalyzed cyclotrimerizaiton reaction. The as-synthesized polymer exhibits a microporous network with high thermal stability. The free volume size of the TFM membranes gradually evolved from a unimodal distribution to a bimodal distribution under annealing, as analyzed by positron annihilation lifetime spectroscopy (PALS). The emergence of the bimodal distribution is probably ascribed to the synergetic effect of quenching and thermal cyclization reaction. In addition, the fractional free volume (FFV) of the membranes presents a concave trend with increasing annealing temperature. Vapor sorption tests reveal that the mass transport properties are closely associated with the free volume evolution, which provides an optimal condition for dehydration of biofuels. A promising separation performance with extremely high water permeability has been attained for dehydration of an 85 wt % ethanol aqueous solution at 45 °C. The study on the free volume evolution of the TFM membranes may provide useful insights about the microstructure and mass transport behavior of the microporous polymeric materials.

  10. Hydrothermal Carbonization of Spent Osmotic Solution (SOS Generated from Osmotic Dehydration of Blueberries

    Directory of Open Access Journals (Sweden)

    Kaushlendra Singh

    2014-09-01

    Full Text Available Hydrothermal carbonization of spent osmotic solution (SOS, a waste generated from osmotic dehydration of fruits, has the potential of transformation into hydrochars, a value-added product, while reducing cost and overall greenhouse gas emissions associated with waste disposal. Osmotic solution (OS and spent osmotic solution (SOS generated from the osmotic dehydration of blueberries were compared for their thermo-chemical decomposition behavior and hydrothermal carbonization. OS and SOS samples were characterized for total solids, elemental composition, and thermo-gravimetric analysis (TGA. In addition, hydrothermal carbonization was performed at 250 °C and for 30 min to produce hydrochars. The hydrochars were characterized for elemental composition, Brunauer-Emmett-Teller (BET surface area, particle shape and surface morphology. TGA results show that the SOS sample loses more weight in the lower temperature range than the OS sample. Both samples produced, approximately, 40%–42% (wet-feed basis hydrochar during hydrothermal carbonization but with different properties. The OS sample produced hydrochar, which had spherical particles of 1.79 ± 1.30 μm diameter with a very smooth surface. In contrast, the SOS sample produced hydrochar with no definite particle shape but with a raspberry-like surface.

  11. Preparation of New Cementitious System using Fly Ash and Dehydrated Autoclaved Aerated Concrete

    Institute of Scientific and Technical Information of China (English)

    SHUI Zhonghe; LU Jianxin; TIAN Sufang; SHEN Peiliang; DING Sha

    2014-01-01

    We experimentally studied the interaction between pozzolanic material (fly ash) and dehydrated autoclaved aerated concrete (DAAC). The DAAC powder was obtained by grinding aerated concrete waste to particles finer than 75μm and was then heated to temperatures up to 900℃. New cementitious material was prepared by proportioning fly ash and DAAC, named as AF. X-ray diffraction (XRD) was employed to identify the crystalline phases of DAAC before and after rehydration. The hydration process of AF was analyzed by the heat of hydration and non-evaporable water content (Wn). The experimental results show that the highest reactivity of DAAC can be obtained by calcining the powder at 700℃and the dehydrated products are mainlyβ-C2S and CaO. The cumulative heat of hydration and Wn was found to be strongly dependent on the replacement level of fly ash, increasing the replacement level of fly ash lowered them in AF. The strength contribution rates on pozzolanic effect of fly ash in AF are always negative, showing a contrary tendency of that of cement-fly ash system.

  12. Process for desalting and dehydration of crude oil including hot water washing and gas stripping

    Energy Technology Data Exchange (ETDEWEB)

    Popp, V.V.; Suditu, I.; Neagu, P.; Fotescu, L.; Mihalache, I.; Tirboiu, D.

    1979-12-25

    Process and apparatus for the desalting and dehydration of crude oil is described, in which the crude oil is washed in one or several stages using fresh or recirculated hot water containing a demulsifier. The crude oil is also passed through a coalescence stage, and a settling stage aimed at obtaining a salt content to meet crude oil specifications. Subsequently the crude oil is led into a lower stripping compartment of a column, in which dehydration is carried out to the desired level by using fuel or combustion gas. The stripping temperature is reached by heating the crude or the gas or both. The gas-vapor mixture is cooled in the upper compartment of the column by a cooling fluid such as the untreated crude oil or recirculated or fresh water, depending upon the nature and salt content of the crude. The cooled gas is recirculated within the column or led to a pipeline for consumption, while the cooling fluid, in the case of water, is recirculated in the unit.

  13. A Comparative Study of Solvothermal and Sol-Gel-Derived Nanocrystalline Alumina Catalysts for Ethanol Dehydration

    Directory of Open Access Journals (Sweden)

    Mingkwan Wannaborworn

    2015-01-01

    Full Text Available The ethanol dehydration to ethylene over alumina catalysts prepared by solvothermal and sol-gel methods was investigated. Also, a commercial alumina was used for comparison purposes. The results showed that the catalytic activity depends on the properties of catalyst derived from different preparation methods and reaction temperature. The alumina synthesized by solvothermal method exhibited the highest activity. This can be attributed to the higher surface area and larger amount of acid site, especially the ratio of weak/strong acid strength as determined by N2 physisorption and NH3-TPD studies. The solvothermal-derived catalyst exhibited an excellent performance with complete ethanol conversion and 100% selectivity to ethylene at 350°C in comparison with other ones. In addition, we further studied the catalytic dehydration of alumina catalyst modified with Fe. The presence of 10 wt.% Fe decreased both conversion and ethylene selectivity. However, the acetaldehyde selectivity apparently increased. It was related to the dehydrogenation pathway that takes place on Fe species.

  14. Slab melting beneath the Cascades Arc driven by dehydration of altered oceanic peridotite

    Science.gov (United States)

    Walowski, Kristina J; Wallace, Paul J.; Hauri, E.H.; Wada, I.; Clynne, Michael A.

    2015-01-01

    Water is returned to Earth’s interior at subduction zones. However, the processes and pathways by which water leaves the subducting plate and causes melting beneath volcanic arcs are complex; the source of the water—subducting sediment, altered oceanic crust, or hydrated mantle in the downgoing plate—is debated; and the role of slab temperature is unclear. Here we analyse the hydrogen-isotope and trace-element signature of melt inclusions in ash samples from the Cascade Arc, where young, hot lithosphere subducts. Comparing these data with published analyses, we find that fluids in the Cascade magmas are sourced from deeper parts of the subducting slab—hydrated mantle peridotite in the slab interior—compared with fluids in magmas from the Marianas Arc, where older, colder lithosphere subducts. We use geodynamic modelling to show that, in the hotter subduction zone, the upper crust of the subducting slab rapidly dehydrates at shallow depths. With continued subduction, fluids released from the deeper plate interior migrate into the dehydrated parts, causing those to melt. These melts in turn migrate into the overlying mantle wedge, where they trigger further melting. Our results provide a physical model to explain melting of the subducted plate and mass transfer from the slab to the mantle beneath arcs where relatively young oceanic lithosphere is subducted.

  15. Methods for dehydration of sugars and sugar alcohols

    Energy Technology Data Exchange (ETDEWEB)

    Holladay, Johnathan E [Kennewick, WA; Hu, Jianli [Kennewick, WA; Zhang, Xinjie [Burlington, MA; Wang, Yong [Richland, WA

    2010-08-10

    The invention includes a method of dehydration of a sugar using a dehydration catalyst and a co-catalyst within a reactor. A sugar is introduced and H.sub.2 is flowed through the reactor at a pressure of less than or equal to about 300 psig to convert at least some of the sugar into an anhydrosugar product. The invention includes a process for producing isosorbide. A starting material comprising sorbitol is flowed into a reactor. H.sub.2 is counter flowed through the reactor. The starting material is exposed to a catalyst in the presence of a co-catalyst which comprises at least one metal. The exposing is conducted at a hydrogen pressure of less than or equal to 300 psig within the reactor and the hydrogen removes at least some of any water present during the exposing and inhibits formation of colored byproducts.

  16. Dehydration Process of Hofmann-Type Layered Solids

    Directory of Open Access Journals (Sweden)

    Edilso Reguera

    2013-04-01

    Full Text Available In the present work the dehydration process of layered solids with formula unit M(H2O2[Ni(CN4]·nH2O, M = Ni, Co, Mn; n = 1, 2, 4 is studied using modulated thermogravimetry. The results show that water molecules need to overcome an energetic barrier (activation energy between 63 and 500 kJ/mol in order to diffuse through the interlayer region. The related kinetic parameters show a dependence on the water partial pressure. On the other hand, X-ray diffraction results provide evidence that the dehydration process is accompanied by framework collapse, limiting the structural reversibility, except for heating below 80 °C where the ordered structure remains. Removal of water molecules from the interlayer region disrupts the long-range structural order of the solid.

  17. The hydration/dehydration behavior of aspartame revisited.

    Science.gov (United States)

    Guguta, C; Meekes, H; de Gelder, R

    2008-03-13

    Aspartame, l-aspartyl-l-phenylalanine methyl ester, has two hydrates (IA and IB), a hemi-hydrate (IIA) and an anhydrate (IIB). The hydration/dehydration behavior of aspartame was investigated using hot-humidity stage X-ray powder diffraction (XRPD) and molecular mechanics modeling in combination with differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The results of this study are compared to earlier studies on aspartame as described in literature. It is shown that earlier transition studies were hampered by incomplete conversions and wrong assignment of the forms. The combination of the techniques applied in this study now shows consistent results for aspartame and yields a clear conversion scheme for the hydration/dehydration behavior of the four forms.

  18. Nocturnal lagophthalmos: never seen before in hypernatraemic dehydration.

    Science.gov (United States)

    Rai, Birendra; Moka, Sudha; Sharif, Farhana

    2014-04-11

    We present two cases in which a 10-month-old male infant and another 15-month-old female child presented with symptoms of sleeping with their eyes wide open (lagophthalmos) with features of gastroenteritis (GE) and dehydration. The first child had been seen and discharged the previous day from the paediatric emergency department (ED) with a diagnosis of GE. He presented the following day with sleeping discomfort with his eyes wide open and ongoing symptoms of GE. The second child presented to the ED with features of GE. She was found to be sleeping in the ED with her eyes wide open. Investigations of both children revealed hypernatraemic dehydration. Correction of the electrolyte imbalance in both cases over a period of 48 h led to the resolution of symptoms.

  19. Effects of snow accumulation on soil temperature and change of salinity in frozen soil from laboratory experiments

    Science.gov (United States)

    Harada, K.; Sato, E.; Ishii, M.; Nemoto, M.; Mochizuki, S.

    2008-12-01

    In order to clarify the effect of snow depth on the ground temperature, snowfalls were occurred on soil samples using an artificial snowfall machine in the laboratory and variations of soil temperatures up to 30cm were measured during snowfall. The snow types used here were dendrites (type A) and sphere (type B). The snow depths on the soil surface were 10cm and 30cm for each snow type, so four deferent experimental results were obtained. At each experiment, two samples with deferent initial volumetric water content were prepared, about 10% and 20%. The initial soil temperature was set to 5°C and temperature in the laboratory was kept at -10°C. Soil temperatures were measured at the depths of 0cm, 10cm, 20cm and 30cm during the snowfall, and continuous measurements were conducted for ten hours after the stop of snowfall. From the experiments, it is confirmed that the soil temperature strongly depended on the depths of snow on the surface, density and water content. The soil sample using the type A with the depth of 30cm snow accumulation had the highest temperature at the surface, followed by the type A with 10cm snow, type B with 30cm snow and type B with 10cm snow. It was also pointed that temperature of the high water content samples showed the high temperature decrease compared with the low water one due to the high heat capacity except for the sample using type A with 10cm snow. Numerical calculation will be needed to explain these results. In addition, another experiment will be carried out to clarify the change of salinity during soil freezing with snow accumulation. The method to measure the salinity of soil is to measure the electrical conductivity of soil and volumetric water content at the same depth. The temperature condition in the cooling bath is ranged between -10 and 5°C and changed in 24 hours. Firstly, the temperature profiles will be measured to detect the frozen front, then measurements will start and discuss the results.

  20. Watching dehydration: transient vein-shaped porosity in the oceanic mantle of the subducting Nazca slab

    Science.gov (United States)

    Bloch, Wasja; John, Timm; Kummerow, Jörn; Wigger, Peter; Salazar, Pablo; Shapiro, Serge

    2016-04-01

    Subduction zones around the world show the common pattern of a Double Seismicity Zone, where seismicity is organized in the form of two sub-parallel planes, one at the plate contact and the other one, 10 to 30 km below, in the mantle of the oceanic lithosphere (Lower Seismicity Zone, LSZ). A commonly held hypothesis states that dehydration processes and the associated mineral reactions promote the earthquakes of the LSZ. Fluids filling a porespace strongly alter the petropyhsical properties of a rock. Especially the seismic P- to S-wave velocity ratio (Vp/Vs) has been shown to be sensitive to the presence of fluid-filled porosity. It transforms uniquely to Poisson's ratio. To test the mineral-dehydration-hypothesis, we use local earthquake data to measure Vp/Vs in the oceanic mantle of the subducting Nazca slab at 21°S. We determine it as the slope of the de-meaned differential P- vs. S-wave arrivaltimes of a dense seismicity cluster in the LSZ. This measurement yields a value for Vp/Vs of 2.10 ± 0.09, i.e. a Poisson's ratio of ˜0.35. This value clearly exceeds the range of Vp/Vs values expected for oceanic mantle rocks in their purely solid form at ˜50km depth. We follow a poroelastic approach to model the rock's elastic properties, including Vp/Vs, as a function of porosity and porespace-geometry. This results in a porespace model for the target volume having a vein-like porosity occupying only a minor volume fraction. Porosity is in the order of 0.1%. These findings are in very good agreement with field surveys and laboratory experiments of mantle dehydration. The pore-geometry is close to the geometrical percolation threshold, where long-ranged interconnectivity statistically emerges, suggesting good draining capabilities. Indeed, porosity is soft so that the amount of porosity and, consequently, permeability is very sensitive to local fluid pressure. We conclude that in the oceanic mantle of the subducting Nazca slab, mineral dehydration reactions are

  1. Attractions in sterically stabilized silica dispersions : II. Experiments on phase separation induced by temperature variation

    NARCIS (Netherlands)

    Jansen, J.W.; Kruif, C.G. de; Vrij, A.

    1986-01-01

    On lowering the temperature initially homogeneous dispersions (in a variety of solvents) of silica coated with octadecyl chains show a separation into two phases of different concentration. The temperature of first instability is not strongly correlated with the solubility parameter of the solvent.

  2. Mechanisms of Aerobic Performance Impairment With Heat Stress and Dehydration

    Science.gov (United States)

    2010-08-01

    uptake ( VO2max ), which leads to higher relative exercise intensity and an exponential decline in aerobic performance at any given exercise workload...reductions, which combine to accentuate cardiovascular strain and reduce VO2max . Importantly, the negative performance consequences of dehydration...environmental heat stress on aerobic exercise “performance” has been evaluated using time to exhaustion (TTE) tests (incremental or constant work rate) and

  3. Dehydration of Aromatic Heterocyclic Carboxamides to Aromatic Heterocyclic Carbonitriles

    Directory of Open Access Journals (Sweden)

    Werner Bonrath

    1997-11-01

    Full Text Available Phosphorus pentoxide is commonly used for the dehydration of heterocyclic carboxamides to the corresponding nitriles. In this report, the use of cyanuric chloride/N,N-disubstituted formamide for this reaction is described. The advantages of this procedure are mild reaction conditions and good yields. Depending on the reaction conditions and the structures of the amides, the nitriles are obtained in yields from 51% to 99%. Several of the oxazole carbonitriles synthesized by this procedure have not yet been described.

  4. Methanol dehydration on carbon-based acid catalysts

    OpenAIRE

    Valero-Romero, Mª José; Calvo-Muñoz, Elisa Mª; Ruiz-Rosas, Ramiro; Rodríguez-Mirasol, José; Cordero, Tomás

    2013-01-01

    Methanol dehydration to produce dimethyl ether (DME) is an interesting process for the chemical industry since DME is an important intermediate and a promising clean alternative fuel for diesel engines. Pure or modified γ-aluminas (γ-Al2O3) and zeolites are often used as catalysts for this reaction. However, these materials usually yield non desirable hydrocarbons and undergo fast deactivation. In this work, we study the catalytic conversion of methanol over an acid carbon catalyst obtaine...

  5. Heat Transport in a Three-Dimensional Slab Geometry and the Temperature Profile of Ingen-Hausz Experiment

    Science.gov (United States)

    Acharya, Shiladitya; Mukherjee, Krishnendu

    2013-05-01

    We study the transport of heat in a three-dimensional, harmonic crystal of slab geometry whose boundaries and the intermediate surfaces are connected to stochastic, white noise heat baths at different temperatures. Heat baths at the intermediate surfaces are required to fix the initial state of the slab in respect of its surroundings. We allow the flow of energy fluxes between the intermediate surfaces and the attached baths and impose conditions that relate the widths of Gaussian noises of the intermediate baths. The radiated heat obeys Newton's law of cooling when intermediate baths collectively constitute the environment surrounding the slab. We show that Fourier's law holds in the continuum limit. We obtain an exponentially falling temperature profile from high to low temperature end of the slab and this very nature of the profile was already confirmed by Ingen-Hausz's experiment. Temperature profile of similar nature is also obtained in the one-dimensional version of this model.

  6. Investigation of the Cause of Low Blister Threshold Temperatures in the RERTR-12 and AFIP-4 Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell K Meyer

    2012-06-01

    Blister–threshold testing of fuel plates is a standard method through which the safety margin for operation of plate-type in research and test reactors is assessed. The blister-threshold temperature is indicative of the ability of fuel to operate at high temperatures for short periods of time (transient conditions) without failure. This method of testing was applied to the newly developed U-Mo monolithic fuel system. Blister annealing studies on the U-Mo monolithic fuel plates began in 2007, with the Reduced Enrichment for Research and Test Reactors (RERTR)-6 experiment, and they have continued as the U-Mo fuel system has evolved through the research and development process. Blister anneal threshold temperatures from early irradiation experiments (RERTR-6 through RERTR-10) ranged from 400 to 500°C. These temperatures were projected to be acceptable for NRC-licensed research reactors and the high-power Advanced Test Reactor (ATR) and the High Flux Isotope Reactor (HFIR) based on current safety-analysis reports (SARs). Initial blister testing results from the RERTR-12 experiment capsules X1 and X2 showed a decrease in the blister-threshold temperatures. Blister threshold temperatures from this experiment ranged from 300 to 400°C. Selected plates from the AFIP-4 experiment, which was fabricated using a process similar to that used to fabricate the RERTR-12 experiment, also underwent blister testing to determine whether results would be similar. The measured blister-threshold temperatures from the AFIP-4 plates fell within the same blister-threshold temperature range measured in the RERTR-12 plates. Investigation of the cause of this decrease in bister threshold temperature is being conducted under the guidance of Idaho National Laboratory PLN-4155, “Analysis of Low Blister Threshold Temperatures in the RERTR-12 and AFIP-4 Experiments,” and is driven by hypotheses. The main focus of the investigation is in the following areas: 1. Fabrication variables 2. Pre

  7. Structural characterisation and dehydration behaviour of siramesine hydrochloride.

    Science.gov (United States)

    Zimmermann, Anne; Tian, Fang; de Diego, Heidi Lopez; Frydenvang, Karla; Rantanen, Jukka; Elema, Michiel Ringkjøbing; Hovgaard, Lars

    2009-10-01

    In this study the crystal structures of siramesine hydrochloride anhydrate alpha-form and siramesine hydrochloride monohydrate were determined, and this structural information was used to explain the physicochemical properties of the two solid forms. In the crystal structure of the monohydrate, each water molecule is hydrogen bonded to two chloride ions, and thus the water is relatively strongly bound in the crystal. No apparent channels for dehydration were observed in the monohydrate structure, which could allow transmission of structural information during dehydration. Instead destructive dehydration occurred, where the elimination of water from the monohydrate resulted in the formation of an oily phase, which subsequently recrystallised into one or more crystalline forms. Solubility and intrinsic dissolution rate of the anhydrate alpha-form and the monohydrate in aqueous media were investigated and both were found to be lower for the monohydrate compared to the anhydrate alpha-form. Finally, the interactions between water molecules and chloride ions in the monohydrate as well as changes in packing induced by water incorporation could be detected by spectroscopic techniques.

  8. Hot experience for cold-adapted microorganisms: temperature sensitivity of soil enzymes

    Science.gov (United States)

    Liu, Shibin; Razavidezfuly, Baharsadat; Kuzyakov, Yakov

    2016-04-01

    The temperature sensitivity of enzymes responsible for organic matter decomposition in cold environment soil, where warming is expected to be greatest is crucial. Based on Michaelis-Menten kinetics and Arrhenius function, we hypothesized that cold-adapted microorganisms will produce high efficient enzymes at cold temperatures (enzymes with lower apparent activation energy (Ea) at cold temperature ranges). To test our hypothesis, 30 g soil of Tibetan Plateau (4100 m a.s.l., annual temperature 2.4 °C) in 4 replicates were incubated for one month over a temperature range of 0-40 °C (with 5 °C steps) and determined the kinetic parameters of six enzymes involved in decomposing organics: cellobiohydrolase and β-glucosidase, which are commonly measured as enzymes responsible for consecutive stages of cellulose degradation; xylanase, which is responsible for breaking down hemicelluloses; acid phosphatase, which mineralizes organic P to phosphate by hydrolyzing phosphoric (mono) ester bonds under acidic conditions. Activities of leucine aminopeptidase and tyrosine aminopeptidase were analyzed to assess the hydrolysis of L-peptide bonds. The apparent activation energy varied between enzymes from 42 (phosphatase) to 54 (cellobiohydrolase) kJ mol-1 corresponding to the Q10 values of the enzyme reactions of 1.8-2.3. The increase of substrate affinity (Km) with temperature was gradual for most tested enzymes from 0-20 °C (enzymes involved in C cycle), (proteases) and 0-40 °C (phosphatase). However, within a high range of temperatures (25-40 °C) the hydrolytic activity was governed by enzymes with nearly constant substrate affinity. Overall, for enzymes involved in C cycle and proteases, a strong increase (30-40%) in Km at high temperatures (25 °C) reflects an expression of multiple isoenzymes each with different temperature optima and probable shift of microbial community. The general trend of catalytic efficiency (Vmax/Km) demonstrated a gradual increase with

  9. High Temperature Electrolysis 4 kW Experiment Design, Operation, and Results

    Energy Technology Data Exchange (ETDEWEB)

    J.E. O' Brien; X. Zhang; K. DeWall; L. Moore-McAteer; G. Tao

    2012-09-01

    This report provides results of long-term stack testing completed in the new high-temperature steam electrolysis multi-kW test facility recently developed at INL. The report includes detailed descriptions of the piping layout, steam generation and delivery system, test fixture, heat recuperation system, hot zone, instrumentation, and operating conditions. This facility has provided a demonstration of high-temperature steam electrolysis operation at the 4 kW scale with advanced cell and stack technology. This successful large-scale demonstration of high-temperature steam electrolysis will help to advance the technology toward near-term commercialization.

  10. Enhanced Catalysis Activity in a Coordinatively Unsaturated Cobalt-MOF Generated via Single-Crystal-to-Single-Crystal Dehydration.

    Science.gov (United States)

    Ren, Hai-Yun; Yao, Ru-Xin; Zhang, Xian-Ming

    2015-07-06

    Hydrothermal reaction of Co(NO3)2 and terphenyl-3,2",5",3'-tetracarboxyate (H4tpta) generated Co3(OH)2 chains based 3D coordination framework Co3(OH)2(tpta)(H2O)4 (1) that suffered from single-crystal-to-single-crystal dehydration by heating at 160 °C and was transformed into dehydrated Co3(OH)2(tpta) (1a). During the dehydration course, the local coordination environment of part of the Co atoms was transformed from saturated octahedron to coordinatively unsaturated tetrahedron. Heterogenous catalytic experiments on allylic oxidation of cyclohexene show that dehydrated 1a has 6 times enhanced catalytic activity than as-synthesized 1 by using tert-butyl hydroperoxide (t-BuOOH) as oxidant. The activation energy for the oxidation of cylcohexene with 1a catalyst was 67.3 kJ/mol, far below the value with 1 catalysts, which clearly suggested that coordinatively unsaturated Co(II) sites in 1a have played a significant role in decreasing the activation energy. It is interestingly found that heterogeneous catalytic oxidation of cyclohexene in 1a not only gives the higher conversion of 73.6% but also shows very high selectivity toward 2-cyclohexene-1-one (ca. 64.9%), as evidenced in high turnover numbers (ca. 161) based on the open Co(II) sites of 1a catalyst. Further experiments with a radical trap indicate a radical chain mechanism. This work demonstrates that creativity of coordinatively unsaturated metal sites in MOFs could significantly enhance heterogeneous catalytic activity and selectivity.

  11. Isothermal Time-Temperature-Precipitation Diagram for an Aluminum Alloy 6005A by In Situ DSC Experiments

    Directory of Open Access Journals (Sweden)

    Benjamin Milkereit

    2014-03-01

    Full Text Available Time-temperature-precipitation (TTP diagrams deliver important material data, such as temperature and time ranges critical for precipitation during the quenching step of the age hardening procedure. Although the quenching step is continuous, isothermal TTP diagrams are often applied. Together with a so-called Quench Factor Analysis, they can be used to describe very different cooling paths. Typically, these diagrams are constructed based on mechanical properties or microstructures after an interrupted quenching, i.e., ex situ analyses. In recent years, an in situ calorimetric method to record continuous cooling precipitation diagrams of aluminum alloys has been developed to the application level by our group. This method has now been transferred to isothermal experiments, in which the whole heat treatment cycle was performed in a differential scanning calorimeter. The Al-Mg-Si-wrought alloy 6005A was investigated. Solution annealing at 540 °C and overcritical quenching to several temperatures between 450 °C and 250 °C were followed by isothermal soaking. Based on the heat flow curves during isothermal soaking, TTP diagrams were determined. An appropriate evaluation method has been developed. It was found that three different precipitation reactions in characteristic temperature intervals exist. Some of the low temperature reactions are not accessible in continuous cooling experiments and require isothermal studies.

  12. Heating and temperature gradients of lipid bilayer samples induced by RF irradiation in MAS solid-state NMR experiments.

    Science.gov (United States)

    Wang, Jing; Zhang, Zhengfeng; Zhao, Weijing; Wang, Liying; Yang, Jun

    2016-05-09

    The MAS solid-state NMR has been a powerful technique for studying membrane proteins within the native-like lipid bilayer environment. In general, RF irradiation in MAS NMR experiments can heat and potentially destroy expensive membrane protein samples. However, under practical MAS NMR experimental conditions, detailed characterization of RF heating effect of lipid bilayer samples is still lacking. Herein, using (1) H chemical shift of water for temperature calibration, we systematically study the dependence of RF heating on hydration levels and salt concentrations of three lipids in MAS NMR experiments. Under practical (1) H decoupling conditions used in biological MAS NMR experiments, three lipids show different dependence of RF heating on hydration levels as well as salt concentrations, which are closely associated with the properties of lipids. The maximum temperature elevation of about 10 °C is similar for the three lipids containing 200% hydration, which is much lower than that in static solid-state NMR experiments. The RF heating due to salt is observed to be less than that due to hydration, with a maximum temperature elevation of less than 4 °C in the hydrated samples containing 120 mmol l(-1) of salt. Upon RF irradiation, the temperature gradient across the sample is observed to be greatly increased up to 20 °C, as demonstrated by the remarkable broadening of (1) H signal of water. Based on detailed characterization of RF heating effect, we demonstrate that RF heating and temperature gradient can be significantly reduced by decreasing the hydration levels of lipid bilayer samples from 200% to 30%. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  13. Analysis of Dehydration and Strength in Elite Badminton Players

    Science.gov (United States)

    Abián-Vicén, Javier; Del Coso, Juan; González-Millán, Cristina; Salinero, Juan José; Abián, Pablo

    2012-01-01

    Background The negative effects of dehydration on aerobic activities are well established. However, it is unknown how dehydration affects intermittent sports performance. The purpose of this study was to identify the level of dehydration in elite badminton players and its relation to muscle strength and power production. Methodology Seventy matches from the National Spanish badminton championship were analyzed (46 men’s singles and 24 women’s singles). Before and after each match, jump height and power production were determined during a countermovement jump on a force platform. Participants’ body weight and a urine sample were also obtained before and after each match. The amount of liquid that the players drank during the match was also calculated by weighing their individual drinking bottles. Results and Discussion Sweat rate during the game was 1.14±0.46 l/h in men and 1.02±0.64 l/h in women. The players rehydrated at a rate of 1.10±0.55 l/h and 1.01±0.44 l/h in the male and female groups respectively. Thus, the dehydration attained during the game was only 0.37±0.50% in men and 0.32±0.83% in women. No differences were found in any of the parameters analyzed during the vertical jump (men: from 31.82±5.29 to 32.90±4.49 W/kg; p>0.05, women: from 26.36±4.73 to 27.25±4.44 W/kg; p>0.05). Post-exercise urine samples revealed proteinuria (60.9% of cases in men and 66.7% in women), leukocyturia (men = 43.5% and women = 50.0%) and erythrocyturia (men = 50.0% and women = 21.7%). Conclusions Despite a moderate sweat rate, badminton players adequately hydrated during a game and thus the dehydration attained was low. The badminton match did not cause muscle fatigue but it significantly increased the prevalence of proteinuria, leukocyturia and erythrocyturia. PMID:22666396

  14. Analysis of dehydration and strength in elite badminton players.

    Directory of Open Access Journals (Sweden)

    Javier Abián-Vicén

    Full Text Available BACKGROUND: The negative effects of dehydration on aerobic activities are well established. However, it is unknown how dehydration affects intermittent sports performance. The purpose of this study was to identify the level of dehydration in elite badminton players and its relation to muscle strength and power production. METHODOLOGY: Seventy matches from the National Spanish badminton championship were analyzed (46 men's singles and 24 women's singles. Before and after each match, jump height and power production were determined during a countermovement jump on a force platform. Participants' body weight and a urine sample were also obtained before and after each match. The amount of liquid that the players drank during the match was also calculated by weighing their individual drinking bottles. RESULTS AND DISCUSSION: Sweat rate during the game was 1.14 ± 0.46 l/h in men and 1.02 ± 0.64 l/h in women. The players rehydrated at a rate of 1.10 ± 0.55 l/h and 1.01 ± 0.44 l/h in the male and female groups respectively. Thus, the dehydration attained during the game was only 0.37 ± 0.50% in men and 0.32 ± 0.83% in women. No differences were found in any of the parameters analyzed during the vertical jump (men: from 31.82 ± 5.29 to 32.90 ± 4.49 W/kg; p>0.05, women: from 26.36 ± 4.73 to 27.25 ± 4.44 W/kg; p>0.05. Post-exercise urine samples revealed proteinuria (60.9% of cases in men and 66.7% in women, leukocyturia (men = 43.5% and women = 50.0% and erythrocyturia (men = 50.0% and women = 21.7%. CONCLUSIONS: Despite a moderate sweat rate, badminton players adequately hydrated during a game and thus the dehydration attained was low. The badminton match did not cause muscle fatigue but it significantly increased the prevalence of proteinuria, leukocyturia and erythrocyturia.

  15. Economic consequences of improved temperature forecasts: An experiment with the Florida citrus growers (control group results). Executive summary. [weather forecasting

    Science.gov (United States)

    1977-01-01

    A demonstration experiment is being planned to show that frost and freeze prediction improvements are possible utilizing timely Synchronous Meteorological Satellite temperature measurements and that this information can affect Florida citrus grower operations and decisions so as to significantly reduce the cost for frost and freeze protection and crop losses. The design and implementation of the first phase of an economic experiment which will monitor citrus growers decisions, actions, costs and losses, and meteorological forecasts and actual weather events was carried out. The economic experiment was designed to measure the change in annual protection costs and crop losses which are the direct result of improved temperature forecasts. To estimate the benefits that may result from improved temperature forecasting capability, control and test groups were established with effective separation being accomplished temporally. The control group, utilizing current forecasting capability, was observed during the 1976-77 frost season and the results are reported. A brief overview is given of the economic experiment, the results obtained to date, and the work which still remains to be done.

  16. Response of benthic foraminifera Rosalina leei to different temperature and salinity, under laboratory culture experiment

    Digital Repository Service at National Institute of Oceanography (India)

    Nigam, R.; Kurtarkar, S.R.; Saraswat, R.; Linshy, V.N.; Rana, S.S.

    and 35 ppt saline water is most suitable for the growth of R. leei. Results are significant as the responses of benthic foraminifera to different temperatures and salinity are being used for palaeoclimatic reconstruction....

  17. Effects of cyclic loading on temperature evolution of ULTIMET superalloy: experiment and theoretical modeling

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    High-speed, high-resolution infrared t hermography, as a non-contact, full-field, and nondestructive technique, was used to study the temperature variations of a cobalt-based ULTIMET alloy subjected to cyclic fatigue. During each fatigue cycle, the temperature oscillations, which were due to the thermal-elastic-plastic effects, were observed and related to stress-strain analyses. The change of temperature during fatigue was utilized to reveal the accumulation of fatigue damage . A constitutive model was developed for predicting the thermal and mechanical responses of ULTIMET alloy subjected to cyclic deformation. The model was constru cted in light of internal-state variables, which were developed to characterize the inelastic strain of the material during cyclic loading. The predicted stress -strain and temperature responses were found to be in good agreement with the e xperimental results.

  18. Plasma Wind Tunnel Testing of Ultra High Temperature Ceramics: Experiments And Numerical Correlation

    OpenAIRE

    Di Maso, Andrea

    2009-01-01

    The thesis is focused on the aerothermodynamic and oxidation behaviour of ultra-high-temperature Ceramic (UHTC) for aerospace applications. UHTC are very high temperature resistant (>2000K) materials, with good chemical inertness and mechanical properties. These materials could be used for next generation aerospace and hypersonic vehicles. The arc jet plasma wind tunnel available at the Department of Aerospace Engineering of Naples (DIAS) is able to reproduce specific total enthalpies and sta...

  19. Relationship of shale dewatering and smectite dehydration to undercompaction occurrence

    Energy Technology Data Exchange (ETDEWEB)

    Leftwich, J.T. Jr.

    1996-12-01

    The cause(s) of abnormal fluid pressures in sedimentary basins are not clearly understood. One step in determining the mechanism(s) of abnormal pressure generation in sedimentary basins is to develop an understanding of the relationship among undercompacted shale, abnormal pressure, and temperature. Our research focused on understanding undercompaction and how it related to smectite-illite conversion. A series of carefully designed experiments were used to help clarify and evaluate the relationship of smectite-illite transformation to undercompaction.

  20. Acetone photophysics at 282 nm excitation at elevated pressure and temperature. I: absorption and fluorescence experiments

    Science.gov (United States)

    Hartwig, Jason; Mittal, Gaurav; Kumar, Kamal; Sung, Chih-Jen

    2017-06-01

    This is the first in a series of two papers that presents new experimental data to extend the range of acetone photophysics to elevated pressure and temperature conditions. In this work, a flexible static and flow system is designed and characterized to study the independent as well as coupled effect of elevated pressure and temperature on acetone photophysics over pressures of 0.05‒4.0 MPa and temperatures of 295‒750 K for 282 nm excitation wavelength in nitrogen and air as bath gases. Experimental results show that at 282 nm excitation, relative fluorescence quantum yield increases with increasing pressure, decreases with increasing temperature, and that the pressure sensitivity varies weakly with elevated temperature. The previously assumed linearity of fluorescence with tracer number density is shown to only be valid over a small range. Additionally, acetone fluorescence is only moderately quenched in the presence of oxygen. The present findings yield insight into the competition between the non-radiative and collisional rates at elevated temperature and pressure, as well as provide validation datasets for an updated fluorescence model developed in the second paper.

  1. The struggle to maintain hydration and osmoregulation in animals experiencing severe dehydration and rapid rehydration: the story of ruminants.

    Science.gov (United States)

    Silanikove, N

    1994-05-01

    Ruminants in tropical and desert areas routinely experience cycles of severe dehydration and rapid rehydration. These animals can withstand severe dehydration (18-40% of initial body weight), which exceeds considerably the capacity of most monogastric mammals. This capacity is related to their ability to use, during the course of dehydration, their large water reservoir in the rumen, which contributes 50-70% of the total water loss. As rumen fluid is in approximate isotonicity with systemic fluid, the utilization of gut water during the course of dehydration involves a considerable load of sodium and potassium. Consequently, the effectiveness of utilization of rumen fluid during dehydration depends on the capacity of the kidney to 'desalt' the water absorbed from the gut and on maintenance of salivary flow to the rumen. Following rehydration, ruminants can imbibe their entire water deficit in one drinking and the entire amount ingested is first retained in the rumen. The rumen volume at this stage may exceed the extracellular fluid volume and the sudden drop in rumen osmolality creates a huge osmotic gradient (200-300 mosmol kg-1) between the rumen and systemic fluid. Ruminant animals are confronted at this stage by two opposing tasks, each of them of vital importance: (i) the need to prevent the osmotic hazard leading to water intoxication; and (ii) the need to retain the ingested water, so that it is not missing for the next dehydration cycle. The most prevalent view until recently was a theory which attributes an osmotic protective mechanism to the rumen wall. However, such a capacity has not yet been demonstrated and is challenged by contradictory observations that large amounts of water are absorbed from the rumen following rehydration. The view that is most consistent with available information is that gustatory-alimentary and hepatoportal signals regarding the presence of large amounts of water in the rumen and the absorption of water from the gut activate a

  2. ATR-FTIR study of water in Nafion membrane combined with proton conductivity measurements during hydration/dehydration cycle.

    Science.gov (United States)

    Kunimatsu, Keiji; Bae, Byungchan; Miyatake, Kenji; Uchida, Hiroyuki; Watanabe, Masahiro

    2011-04-21

    We have conducted combined time-resolved attenuated total reflection Fourier transform infrared (ATR-FTIR) and proton conductivity measurements of Nafion NRE211 membrane during hydration/dehydration cycles at room temperature. Conductivity change was interpreted in terms of different states of water in the membrane based on its δ(HOH) vibrational spectra. It was found that hydration of a dry membrane leads first to complete dissociation of the sulfonic acid groups to liberate hydrated protons, which are isolated from each other and have δ(HOH) vibrational frequency around 1740 cm(-1). The initial hydration is not accompanied by a significant increase of the proton conductivity. Further hydration gives rise to a rapid increase of the conductivity in proportion to intensity of a new δ(HOH) band around 1630 cm(-1). This was interpreted in terms of formation of channels of weakly hydrogen-bonded water to combine the isolated hydrophilic domains containing hydrated protons and hydrated sulfonate ions produced during the initial stage of hydration. Upon dehydration, proton conductivity drops first very rapidly due to loss of the weakly hydrogen bonded water from the channels to leave hydrophilic domains isolated in the membrane. Dehydration of the protons proceeds very slowly after significant loss of the proton conductivity.

  3. Detection and diagnosis of a natural gas dehydration plant by absorption with triethylene glycol, employing a artificial neural networks

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    The natural gas dehydration is a great importance operation in the gas and petroleum industry, It avoids operational problems associated with the water content, which appear frequently in the industrial facilities that use the natural gas as raw material or as work tool. Due to the presence of undesirable pollutants which may enter the plant with the wet natural gas current (lubricating, corrosion inhibitors, salts, and others), the equipment that constitutes the dehydration plants are capable to suffering operational faults as the heat exchangers fouling, foam formation in the absorber, glycol losses for dragging; trays, packings, valves and filters fouling; glycol degradation, inadequate temperatures of regeneration and others. The above mentioned faults often cannot be detected by the operators and engineers but up to the moment when a catastrophic damage occurs or when products are obtained out of specification, which causes big economic and time losses. By means of the application of artificial neural networks, there was achieved the detection and the effective diagnosis of faults, still in incipient state, in a gas dehydration plant. (author)

  4. Operation experiences with a 30 kV/100 MVA high temperature superconducting cable system

    DEFF Research Database (Denmark)

    Tønnesen, Ole; Däumling, Manfred; Jensen, Kim Høj;

    2004-01-01

    of 1157 A. The operation experiences include over-currents of 6 kA due to faults on peripheral lines, commissioning, servicing and failure responses on the cooling system, continuous 24 h, 7 day per week monitoring and performance of the alarm system. The implications of these experiences for the future...

  5. Cold trap dehydration in the Tropical Tropopause Layer characterised by SOWER chilled-mirror hygrometer network data in the Tropical Pacific

    Directory of Open Access Journals (Sweden)

    F. Hasebe

    2013-04-01

    Full Text Available A network of balloon-borne radiosonde observations employing chilled-mirror hygrometers for water and electrochemical concentration cells for ozone has been operated since the late 1990s in the Tropical Pacific to capture the evolution of dehydration of air parcels advected quasi-horizontally in the Tropical Tropopause Layer (TTL. The analysis of this dataset is made on isentropes taking advantage of the conservative properties of tracers moving adiabatically. The existence of ice particles is diagnosed by lidars simultaneously operated with sonde flights. Characteristics of the TTL dehydration are presented on the basis of individual soundings and statistical features. Supersaturations close to 80% in relative humidity with respect to ice (RHice have been observed in subvisible cirrus clouds located near the cold point tropopause at extremely low temperatures around 180 K. Although further observational evidence is needed to confirm the credibility of such high values of RHice, the evolution of TTL dehydration is evident from the data in isentropic scatter plots between the sonde-observed mixing ratio (OMR and the minimum saturation mixing ratio (SMRmin along the back trajectories associated with the observed air mass. Supersaturation exceeding the critical value of homogeneous ice nucleation (OMR > 1.6 × SMRmin is frequently observed on the 360 and 365 K surfaces indicating that cold trap dehydration is in progress in the TTL. The near correspondence between the two (OMR ~ SMRmin at 380 K on the other hand implies that this surface is not sufficiently cold for the advected air parcels to be dehydrated. Above 380 K, cold trap dehydration would scarcely function while some moistening occurs before the air parcels reach the lowermost stratosphere at around 400 K where OMR is generally smaller than SMRmin.

  6. Alleviating effects of dehydration under no hyperthermia on the immunomodulatory response to the polysaccharide fraction from fu-ling (Poria cocos) in male collegiate wrestlers

    Institute of Scientific and Technical Information of China (English)

    JANG Tsong-rong; KAO Ming-feng; CHEN Chun-hao; HSIEH Kuen-chang; LAI Wen-yam; CHEN Yu-yawn

    2011-01-01

    Background It is well known that dehydration can impair bodily functions. To evaluate the impact of hydration status under ambient environmental temperature on the immune system, 25 male collegiate wrestlers were recruited to undergo an experimental dehydration program.Methods Thirteen subjects had controlled diets with individual energy requirements to prevent body mass loss and restricted water intake to cause 4.52% dehydration; they formed the dehydrated group (DE). These subjects developed a urine specific gravity of about 1.030 in 84 hours. Twelve other subjects had no water restriction and maintained their total body weight comprised the euhydrated group (EU). Peripheral blood monocytes (PBMNC) were isolated after dehydration to perform immune response testing by being incubated with a polysaccharide fraction from fu-ling, Poria cocos (polysaccharide fraction from Poria cocos, PCPS, 1-30 μg/L), to prepare a conditioned medium termed conditioned medium of PBMNC stimulated by PCPS (PCPS-MNC-CM). More PCPS (25 μg/L) was needed in the DE group to prepare the PCPS-MNC-CM, which was assayed with a growth inhibitory curve for treated U973 cells.Results The treated U937 cells, incubated together with PCPS-MNC-CM from the DE group, exhibited a much lower nitroblue tetrazolium (NBT) positive value of (63.7±4.7)%. The concentration of interferon-gamma (IFN-Y), interleukin (IL)-1β and tumor necrosis factor (TNF)-α in PCPS-MNC-CM from subjects after dehydration was much lower than in the CM from the EU group.Conclusion The immune response to PCPS in the DE group was lower than in normally hydrated subjects.

  7. ANALISIS PERMEASI AIR PADA DEHIDRASI OSMOSIS PEPAYA (Carica papaya Water Permeation Analysis on Osmotic Dehydration of Papaya (Carica papaya

    Directory of Open Access Journals (Sweden)

    Sang Kompiang Wirawan

    2013-11-01

    Full Text Available Fruit preservation using low temperature drying is commonly initiated by osmotic dehydration process. The osmotic time is strongly influenced by the water permeation from the fruit to the osmotic solution. This research aimed to study the osmotic dehydration process of papaya by finding out the permeation rate of water to the osmotic solution across a semi permeable membrane. The effect of temperature and osmotic solution concentration on the permeation rate were also observed. The osmotic temperatures were 30, 40, 50, and 60oC, and the osmotic solution concentration were 55, 60, 65, and 70%. In order to study the water permeation through the semi permeable membrane, a simple mass transfer mathematical models based on Fick’s and Van’t Hoff laws were applied. Generally, higher temperature and osmotic solution concentration, higher water permeation rate was achieved. The results also showed that osmotic dehydration has the same identity or characteristic as drying process at high temperature. The water removal from product slices into the osmotic solution increased by the increase of osmotic period. The mass transfer coefficient and effective diffusivity of water increased when temperature and osmotic solution concentration were increased. However, the membrane permeability has a special characteristic at the ranges conditions studied. Keywords: Osmotic, permeation, dehydration, permeable, membrane ABSTRAK Pengawetan buah dengan pengeringan suhu rendah pada umumnya diawali dengan proses dehidrasi osmosis. Lama waktu osmosis sangat dipengaruhi oleh permeasi air dari bahan ke larutan osmosis. Penelitian ini bertujuan untuk mempelajari proses dehidrasi osmosis dan kecepatan permeasi air dari pepaya ke larutan gula sebagai larutan osmosis melalui membran semipermeabel. Pengaruh suhu dan konsentrasi larutan osmosis terhadap kecepatan permeasi air juga diamati. Suhu osmosis adalah 30, 40, 50, dan 60oC, sedangkan konsentrasi larutan osmosis 55, 60

  8. Experiment and mechanism investigation on advanced reburning for NOx reduction: influence of CO and temperature

    Institute of Scientific and Technical Information of China (English)

    WANG Zhi-hua; ZHOU Jun-hu; ZHANG Yan-wei; LU Zhi-min; FAN Jian-ren; CEN Ke-fa

    2005-01-01

    Pulverized coal reburning, ammonia injection and advanced reburning in a pilot scale drop tube furnace were investigated. Premix of petroleum gas, air and NH3 were burned in a porous gas burner to generate the needed flue gas. Four kinds of pulverized coal were fed as reburning fuel at constant rate of 1g/min. The coal reburning process parameters including 15%~25% reburn heat input, temperature range from 1100 ℃ to 1400 ℃ and also the carbon in fly ash, coal fineness, reburn zone stoichiometric ratio, etc. were investigated. On the condition of 25% reburn heat input, maximum of 47% NO reduction with Yanzhou coal was obtained by pure coal reburning. Optimal temperature for reburning is about 1300 ℃ and fuel-rich stoichiometric ratio is essential; coal fineness can slightly enhance the reburning ability. The temperature window for ammonia injection is about 700 ℃~1100 ℃. CO can improve the NH3 ability at lower temperature. During advanced reburning, 72.9% NO reduction was measured. To achieve more than 70% NO reduction, Selective Non-catalytic NOx Reduction (SNCR) should need NH3/NO stoichiometric ratio larger than 5, while advanced reburning only uses common dose of ammonia as in conventional SNCR technology. Mechanism study shows the oxidization of CO can improve the decomposition of H2O, which will rich the radical pools igniting the whole reactions at lower temperatures.

  9. Dehydration-induced vasopressin secretion in humans: involvement of the histaminergic system.

    Science.gov (United States)

    Kjaer, A; Knigge, U; Jørgensen, H; Warberg, J

    2000-12-01

    In rats, the hypothalamic neurotransmitter histamine participates in regulation of vasopressin secretion and seems to be of physiological importance, because blockade of the histaminergic system reduces dehydration-induced vasopressin secretion. We investigated whether histamine is also involved in regulation of vasopressin secretion during dehydration in humans. We found that 40 h of dehydration gradually increased plasma osmolality by 10 mosmol/kg and induced a fourfold increase in vasopressin levels. Pretreatment with the H(2)-receptor antagonists cimetidine or ranitidine significantly reduced the dehydration-induced increase in vasopressin levels approximately 40% after 34 and 37 h of dehydration, whereas this was not the case with the H(1)-receptor antagonist mepyramine. Dehydration reduced aldosterone secretion by approximately 50%. This effect of dehydration was reduced by both H(1)- and H(2)-receptor blockade after 16 and/or 34 h of dehydration. We conclude that vasopressin secretion in response to dehydration in humans is under the regulatory influence of histamine and that the effect seems to be mediated via H(2)-receptors. In addition, the regulation of aldosterone secretion during dehydration also seems to involve the histaminergic system via H(1) and H(2) receptors.

  10. Hydrolytically stable fluorinated metal-organic frameworks for energy-efficient dehydration

    Science.gov (United States)

    Cadiau, Amandine; Belmabkhout, Youssef; Adil, Karim; Bhatt, Prashant M.; Pillai, Renjith S.; Shkurenko, Aleksander; Martineau-Corcos, Charlotte; Maurin, Guillaume; Eddaoudi, Mohamed

    2017-05-01

    Natural gas must be dehydrated before it can be transported and used, but conventional drying agents such as activated alumina or inorganic molecular sieves require an energy-intensive desiccant-regeneration step. We report a hydrolytically stable fluorinated metal-organic framework, AlFFIVE-1-Ni (KAUST-8), with a periodic array of open metal coordination sites and fluorine moieties within the contracted square-shaped one-dimensional channel. This material selectively removed water vapor from gas streams containing CO2, N2, CH4, and higher hydrocarbons typical of natural gas, as well as selectively removed both H2O and CO2 in N2-containing streams. The complete desorption of the adsorbed water molecules contained by the AlFFIVE-1-Ni sorbent requires relatively moderate temperature (~105°C) and about half the energy input for commonly used desiccants.

  11. Recovery of proteins and amino acids from reverse micelles by dehydration with molecular sieves.

    Science.gov (United States)

    Gupta, R B; Han, C J; Johnston, K P

    1994-09-20

    A new method is presented to precipitate proteins and amino acids from reverse micelles by dehydrating the micelles with molecular sieves. Nearly complete precipitation is demonstrated for alpha-chymotrypsin, cytochromec, and trytophan from 2-ethylhexyl sodium sulfosuccinate (AOT)/isooctane/water reverse micelle solutions. The products precipitate as a solid powder, which is relatively free of surfactant. The method does not require any manipulation of pH, ionic strength, temperature, pressure, or solvent composition, and is applicable over a broad range of these properties. This general approach is compared with other techniques. This general approach is compared with other techniques for the recovery of biomolecules from reverse micelles. (c) 1994 John Wiley & Sons, Inc.

  12. Hydrolytically stable fluorinated metal-organic frameworks for energy-efficient dehydration

    KAUST Repository

    Cadiau, Amandine

    2017-05-18

    Natural gas must be dehydrated before it can be transported and used, but conventional drying agents such as activated alumina or inorganic molecular sieves require an energy-intensive desiccant-regeneration step. We report a hydrolytically stable fluorinated metal-organic framework, AlFFIVE-1-Ni (KAUST-8), with a periodic array of open metal coordination sites and fluorine moieties within the contracted square-shaped one-dimensional channel. This material selectively removed water vapor from gas streams containing CO2, N2, CH4, and higher hydrocarbons typical of natural gas, as well as selectively removed both H2O and CO2 in N2-containing streams. The complete desorption of the adsorbed water molecules contained by the AlFFIVE-1-Ni sorbent requires relatively moderate temperature (~105°C) and about half the energy input for commonly used desiccants.

  13. Optimizing dehydration of apples Malus Domestica with fructo-oligosaccharide incorporation

    Directory of Open Access Journals (Sweden)

    Mariana Buranelo Egea

    2012-10-01

    Full Text Available The objective of the present study was to study the effect of the variables of the osmotic dehydration process on sliced Fuji apples (Malus domestica using a 2 x 3² factorial design. The variables studied in the apple slices were the pretreatment (blanching or acidification, the temperatures (30, 45 and 60ºC and the FOS concentration (40%, 50% and 60% m/v of the osmotic solution. There was no difference among the pretreatments for the water activity and titratable acidity. The slices pre-treated by the acidification presented less enzymatic browning (greatest luminosity L* value combined with a greater soluble solid contents (thus, this treatment was selected. Treatments T4 (45ºC and 40% m/v and T7 (60ºC and 40%m/v, using the acidification presented responses within the recommended standards and FOS were validated by the repetition.

  14. Dehydrated halloysite intercalated mechanochemically with urea: thermal behavior and structural aspects.

    Science.gov (United States)

    Nicolini, Keller Paulo; Fukamachi, Cristiane Regina Budziak; Wypych, Fernando; Mangrich, Antonio Salvio

    2009-10-15

    Urea has been intercalated mechanochemically into dehydrated halloysite and analyzed by X-ray powder diffraction (XRPD), Fourier transform infrared spectroscopy (FTIR), diffuse reflectance ultraviolet/visible spectroscopy (DRUV-VIS), thermal analysis (TGA/DTA), transmission electron microscopy (TEM), and electron paramagnetic resonance (EPR). The basal distance expands from 7.4 to 10.7 A and the interaction of urea to adjacent layers of halloysite through hydrogen bonds increases the structural order of the matrix. After heat treatment in air at different temperatures, decomposition products begin to appear starting from 100 degrees C. Although the basal distance remains constant up to 160 degrees C and collapses to the original value at 200 degrees C, urea and the decomposition products are still present in the sample. Starting from 125 degrees C, urea decomposition products reduce halloysite structural Fe3+ centers to Fe2+, as indicated by DRUV-VIS and EPR spectroscopy.

  15. PRODUCTION OF 5-HYDROXYMETHYLFURFURAL (HMF VIA FRUCTOSE DEHYDRATION: EFFECT OF SOLVENT AND SALTING-OUT

    Directory of Open Access Journals (Sweden)

    F. N. D. C. Gomes

    2015-03-01

    Full Text Available Abstract 5-Hydroxymethylfurfural (HMF is a key renewable platform compound for production of fuels and chemical intermediates. The production of 5-hydroxymethylfurfural (HMF from fructose dehydration was studied using H3PO4 as catalyst, in organic/water system with different solvents (acetone, 2-butanol and ethyl ether. The effect of fructose concentration, temperature and acid concentration was investigated in acetone/water medium. The increase in fructose concentration favors the formation of condensation products and rehydration products are favored at high acid concentration. The solvents exhibited similar performance when the volume ratio of organic to aqueous phase was 1:1, but when this ratio increases to 2:1, the HMF yield obtained with ether was much lower. NaCl addition to the aqueous phase promoted the extraction of HMF to the organic phase, with an HMF yield of 80% in the case of 2:1 acetone/water medium.

  16. Non-contact temperature measurement. [in containerless space-based experiments

    Science.gov (United States)

    Nordine, Paul C.; Krishnan, Shankar; Weber, J. K. R.; Schiffman, Robert A.

    1991-01-01

    Three methods for noncontact temperature measurement are presented. Ideal gas thermometry is realized by using laser-induced fluorescence to measure the concentration of mercury atoms in a Hg-Ar mixture in the vicinity of hot specimens. Emission polarimetry is investigated by measuring the spatially resolved intensities of polarized light from a hot tungsten sphere. Laser polarimetry is used to measure the optical properties, emissivity, and, in combination with optical pyrometry, the temperature of electromagnetically levitated liquid aluminum. The precision of temperature measurements based on the ideal gas law is + or - 2.6 percent at 1500-2000 K. The polarized emission technique is found to have the capability to determine optical properties and/or spectral emissivities of specimens over a wide range of wavelengths with quite simple instruments.

  17. Infrared experiment on the wall temperature distribution for a particle packed channel with constant heat flux

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    With constant heat flux, wall temperature distribution for a particle filled channel was measured using infrared thermal vision technology. It was found that nonuniform relative high-temperature regions were randomly distributed on the heating wall, possibly due to the lower flow velocity, or even due to the blocked flow near the points where particles contact with the heating wall directly. Not only porosity but also the size and shape of the pores are changed in the wall region of particle-packed structures,because of the limitation of the wall, and the changes affect largely the fluid flow and heat transfer. The transition of the flow pattern in pores can be inferred according to the variation of Nu with Re, where the area weighted wall temperature is adopted to calculate the Nu.``

  18. Temperature dependence of the critical current of the superconducting microladder in zero magnetic field: Theory and experiment

    Energy Technology Data Exchange (ETDEWEB)

    Fink, H.J. (Department of Electrical Engineering and Computer Science, University of California, Davis, Davis, California 95616 (USA)); Buisson, O.; Pannetier, B. (Centre de Recherches sur les Tres Basses Temperature, Centre National de la Recherche Scientifique, Boite Postale 166X, 38042 Grenoble CEDEX, France (FR))

    1991-05-01

    The largest supercurrent which can be injected into a superconducting microladder was calculated as a function of nodal spacing {ital scrL} and temperature for zero magnetic flux using (i) exact solutions of the Ginzburg-Landau equation in terms of Jacobian elliptic functions and (ii) approximate solutions in terms of hyperbolic functions. The agreement is good for {ital scrL}/{xi}({ital T}){lt}3, where {xi}({ital T}) is the temperature-dependent coherence length. Since solution (ii) is much simpler than solution (i), it is of considerable value when calculating critical currents of micronets with nodal spacings comparable to {xi}({ital T}). We find that the temperature-dependent critical current deviates significantly from the classical 3/2 power law of the Ginzburg-Landau theory. Preliminary experiments on a submicrometer ladder confirm such deviations.

  19. Two dimensional RMHD modeling of effective ion temperatures in recent ZR argon experiments

    Energy Technology Data Exchange (ETDEWEB)

    Giuliani, J. L., E-mail: john.giuliani@nrl.navy.mil; Thornhill, J. W., E-mail: john.giuliani@nrl.navy.mil; Dasgupta, A. [Plasma Physics Division, Naval Research Laboratory, Washington DC 20375 (United States); Apruzese, J. P. [Engility Corp., Chantilly, VA 20151 (United States); Jones, B.; Harvey-Thompson, A. J.; Ampleford, D. J.; Jennings, C. A.; Hansen, S. B.; Moore, N. W.; Lamppa, D. C.; Coverdale, C. A.; Cuneo, M. E.; Rochau, G. A. [Sandia National Laboratories, Albuquerque NM 87185 (United States)

    2014-12-15

    Radiation magnetohydrodynamic r-z simulations are performed of recent Ar shots on the refurbished Z generator to examine the effective ion temperature as determined from the observed line width of the He-γ line. While many global radiation properties can be matched to experimental results, the Doppler shifts due to velocity gradients at stagnation cannot reproduce the large experimentally determined width corresponding to an effective ion temperature of 50 keV. Ion viscous heating or magnetic bubbles are considered, but understanding the width remains an unsolved challenge.

  20. 泥浆压滤脱水复合絮凝剂的实验研究%Experimental Study on Construction Waste Slurry Dehydration Composite Flocculants

    Institute of Scientific and Technical Information of China (English)

    耿朋飞; 孙林柱

    2014-01-01

    为了研究废弃泥浆的压滤脱水性能,提高泥浆压滤脱水速率,采用正交试验的方法,对不同类型絮凝剂在不同剂量下对泥浆脱水的影响进行正交设计,采用泥浆压滤设备,获得不同加药量时泥浆脱水量与时间的变化关系,通过正交试验极差和因素分析,得到淤泥质粘土废弃泥浆压滤脱水剂的最优组合及其配比.结果表明,阴离子型聚丙烯酰胺絮凝剂与Ca(OH)2、粉煤灰、十二烷基硫酸钠等双组分或多组分压滤脱水剂要比单组分的脱水效果好,在多组分最优组合及最优配比下,泥浆的脱水速率得到快速提高,泥浆的脱水性能得到极大改善,研究结果对于工程中泥浆处理具有重要的技术指导意义.%The waste slurry is difficult to transport and conduct due to its high water content.Improving the dehydration property of the cement is the primary task at present.Using the orthogonal experiment,a series of experiments were done to investigate the dewatering performance of the slurry with various types and different volumes of dehydration.The relationship of dehydration water amount and dehydration time was obtained.The optimal components of different dehydration types and best ratios were acquired based on range analysis and factor analysis.The experimental results indicate that the multi-component dehydrations of PAM,lime,fly ash,sodium lauryl ether sulfate have a better dehydration effect than using them singly.The dehydration rate increases obviously and the dewatering property improves distinctly.The results are of great importance in technical guidance for slurry treatment in various engineering.

  1. Effect of temperature and moisture on the mineralization and humification of leaf litter in a model incubation experiment

    Science.gov (United States)

    Larionova, A. A.; Maltseva, A. N.; Lopes de Gerenyu, V. O.; Kvitkina, A. K.; Bykhovets, S. S.; Zolotareva, B. N.; Kudeyarov, V. N.

    2017-04-01

    The mineralization and humification of leaf litter collected in a mixed forest of the Prioksko-Terrasny Reserve depending on temperature (2, 12, and 22°C) and moisture (15, 30, 70, 100, and 150% of water holding capacity ( WHC)) has been studied in long-term incubation experiments. Mineralization is the most sensitive to temperature changes at the early stage of decomposition; the Q 10 value at the beginning of the experiment (1.5-2.7) is higher than at the later decomposition stages (0.3-1.3). Carbon losses usually exceed nitrogen losses during decomposition. Intensive nitrogen losses are observed only at the high temperature and moisture of litter (22°C and 100% WHC). Humification determined from the accumulation of humic substances in the end of incubation decreases from 34 to 9% with increasing moisture and temperature. The degree of humification CHA/CFA is maximum (1.14) at 12°C and 15% WHC; therefore, these temperature and moisture conditions are considered optimal for humification. Humification calculated from the limit value of litter mineralization is almost independent of temperature, but it significantly decreases from 70 to 3% with increasing moisture. A possible reason for the difference between the humification values measured by two methods is the conservation of a significant part of hemicelluloses, cellulose, and lignin during the transformation of litter and the formation of a complex of humic substances with plant residues, where HSs fulfill a protectoral role and decrease the decomposition rate of plant biopolymers.

  2. Transient cutaneous vasodilatation and hypotension after drinking in dehydrated and exercising men.

    Science.gov (United States)

    Kamijo, Yoshi-Ichiro; Okumoto, Tadashi; Takeno, Yoshiaki; Okazaki, Kazunobu; Inaki, Mitsuharu; Masuki, Shizue; Nose, Hiroshi

    2005-10-15

    We examined whether oropharyngeal stimulation by drinking released the dehydration-induced suppression of cutaneous vasodilatation and decreased mean arterial pressure (MAP) in exercising subjects, and assessed the effects of hypovolaemia or hyperosmolality alone on these responses. Seven young males underwent four hydration conditions. These were two normal plasma volume (PV) trials: normal plasma osmolality (P(osmol), control trial) and hyperosmolality (DeltaP(osmol) = +11 mosmol (kg H(2)O)(-1)); and two low PV trials: isosmolality (DeltaPV = -310 ml) and hyperosmolality (DeltaPV = -345 ml; DeltaP(osmol) = +9 mosmol (kg H(2)O)(-1)), attained by combined treatment with furosemide (frusemide), hypertonic saline and/or 24 h water restriction. In each trial, the subjects exercised at 60% peak aerobic power for approximately 50 min at 30 degrees C atmospheric temperature and 50% relative humidity. When oesophageal temperature (T(oes)) reached a plateau after approximately 30 min of exercise, the subjects drank 200 ml water at 37.5 degrees C within a minute. Before drinking, forearm vascular conductance (FVC), calculated as forearm blood flow divided by MAP, was lowered by 20-40% in hypovolaemia, hyperosmolality, or both, compared with that in the control trial, despite increased T(oes). After drinking, FVC increased by approximately 20% compared with that before drinking (P < 0.05) in both hyperosmotic trials, but it was greater in normovolaemia than in hypovolaemia (P < 0.05). However, no increases occurred in either isosmotic trial. MAP fell by 4-8 mmHg in both hyperosmotic trials (P < 0.05) after drinking, but more rapidly in normovolaemia than in hypovolaemia. PV and P(osmol) did not change during this period. Thus, oropharyngeal stimulation by drinking released the dehydration-induced suppression of cutaneous vasodilatation and reduced MAP during exercise, and this was accelerated when PV was restored.

  3. Continuous depth-sensing nano-mechanical characterization of living, fixed and dehydrated cells attached on a glass substrate

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yun-Ta; Liao, Jiunn-Der; Chang, Chia-Wei [Department of Materials Science and Engineering, National Cheng Kung University, No. 1, University Road, Tainan 70101, Taiwan (China); Lin, Chou-Ching K [Department of Neurology, National Cheng Kung University, No. 1, University Road, Tainan 70101, Taiwan (China); Ju, Ming-Shaung, E-mail: jdliao@mail.ncku.edu.tw [Department of Mechanical Engineering, National Cheng Kung University, No. 1, University Road, Tainan 70101, Taiwan (China)

    2010-07-16

    Continuous depth-sensing nano-indentation on living, fixed and dehydrated fibroblast cells was performed using a dynamic contact module and vertically measured from a pre-contact state to the glass substrate. The nano-indentation tip-on-cell approaches took advantage of finding a contact surface, followed by obtaining a continuous nano-mechanical profile along the nano-indentation depths. In the experiment, serial indentations from the leading edge, i.e., the lamellipodium to nucleus regions of living, fixed and dehydrated fibroblast cells were examined. Nano-indentations on a living cell anchored upon glass substrate were competent in finding the tip-on-cell contact surfaces and cell heights. For the result on the fixed and the dehydrated cells, cellular nano-mechanical properties were clearly characterized by continuous harmonic contact stiffness (HCS) measurements. The relations of HCS versus measured displacement, varied from the initial tip-on-cell contact to the glass substrate, were presumably divided into three stages, respectively induced by cellular intrinsic behavior, the substrate-dominant property, and the substrate property. This manifestation is beneficial to elucidate how the underlying substrate influences the interpretation of the nano-mechanical property of thin soft matter on a hard substrate. These findings, based upon continuous depth-sensing nano-indentations, are presumably valuable as a reference to related work, e.g., accomplished by atomic force microscopy.

  4. Temperature-induced increase in methane release from peat bogs: A mesocosm experiment

    NARCIS (Netherlands)

    Winden, J.F. van; Reichart, G.-J.; McNamara, N.P.; Benthien, A.; Sinninghe Damsté, J.S.

    2012-01-01

    Peat bogs are primarily situated at mid to high latitudes and future climatic change projections indicate that these areas may become increasingly wetter and warmer. Methane emissions from peat bogs are reduced by symbiotic methane oxidizing bacteria (methanotrophs). Higher temperatures and

  5. Temperature-Induced Increase in Methane Release from Peat Bogs: A Mesocosm Experiment

    NARCIS (Netherlands)

    van Winden, J.F.; Reichart, G.J.; McNamara, N.P.; Benthien, A.; Sinninghe Damsté, J.S.

    2012-01-01

    Peat bogs are primarily situated at mid to high latitudes and future climatic change projections indicate that these areas may become increasingly wetter and warmer. Methane emissions from peat bogs are reduced by symbiotic methane oxidizing bacteria (methanotrophs). Higher temperatures and

  6. Temperature-Induced Increase in Methane Release from Peat Bogs: A Mesocosm Experiment

    NARCIS (Netherlands)

    van Winden, J.F.; Reichart, G.J.; McNamara, N.P.; Benthien, A.; Sinninghe Damsté, J.S.

    2012-01-01

    Peat bogs are primarily situated at mid to high latitudes and future climatic change projections indicate that these areas may become increasingly wetter and warmer. Methane emissions from peat bogs are reduced by symbiotic methane oxidizing bacteria (methanotrophs). Higher temperatures and increasi

  7. Temperature-induced increase in methane release from peat bogs: A mesocosm experiment

    NARCIS (Netherlands)

    Winden, J.F. van; Reichart, G.-J.; McNamara, N.P.; Benthien, A.; Sinninghe Damsté, J.S.

    2012-01-01

    Peat bogs are primarily situated at mid to high latitudes and future climatic change projections indicate that these areas may become increasingly wetter and warmer. Methane emissions from peat bogs are reduced by symbiotic methane oxidizing bacteria (methanotrophs). Higher temperatures and increasi

  8. Measurements of Humidity and Temperature in the Marine Environment during the HEXOS Main Experiment

    NARCIS (Netherlands)

    Katsaros, K.B.; Cosmo, J. de; Lind, R.J.; Anderson, R.J.; Smith, S.D.; Kraan, R.; Oost, W.A.; Uhlig, K.; Mestayer, P.G.; Larsen, S.E.; Smith, M.H.; Leeuw, G. de

    1994-01-01

    Accurate measurement of fluctuations in temperature and humidity are needed for determination of the surface evaporation rate and the air-sea sensible heat flux using either the eddy correlation or inertial dissipation method for flux calculations. These measurements are difficult to make over the o

  9. Experiences with high temperature corrosion at straw‐firing power plants in Denmark

    DEFF Research Database (Denmark)

    Montgomery, Melanie; Jensen, S. A.; Borg, U.;

    2011-01-01

    temperature is measured on the specific tube loops where there are test tube sections. Thus a corrosion rate can be coupled to a temperature histogram. This is important since although a superheater has a defined steam outlet temperature, there is variation in the tube bundle due to variations of heat flux...... from the flue gas. This paper will describe the corrosion investigations for tube sections removed from Maribo Sakskøbing and Avedøre 2 biomass boiler which have been exposed for up to 30 000 h. In addition to monitoring the corrosion rates of actual components, there is a need to measure corrosion......By the end of 2009, there will be eight biomass and five biomass co‐firing plants in Denmark. Due to the steep increase of corrosion rate with respect to temperature in biomass plants, it is not viable to have similar steam data as fossil fuel plants. Thus for the newer plants, Maribo Sakskøbing...

  10. Effects of gas temperature on nozzle damping experiments on cold-flow rocket motors

    Science.gov (United States)

    Sun, Bing-bing; Li, Shi-peng; Su, Wan-xing; Li, Jun-wei; Wang, Ning-fei

    2016-09-01

    In order to explore the impact of gas temperature on the nozzle damping characteristics of solid rocket motor, numerical simulations were carried out by an experimental motor in Naval Ordnance Test Station of China Lake in California. Using the pulse decay method, different cases were numerically studied via Fluent along with UDF (User Defined Functions). Firstly, mesh sensitivity analysis and monitor position-independent analysis were carried out for the computer code validation. Then, the numerical method was further validated by comparing the calculated results and experimental data. Finally, the effects of gas temperature on the nozzle damping characteristics were studied in this paper. The results indicated that the gas temperature had cooperative effects on the nozzle damping and there had great differences between cold flow and hot fire test. By discussion and analysis, it was found that the changing of mainstream velocity and the natural acoustic frequency resulted from gas temperature were the key factors that affected the nozzle damping, while the alteration of the mean pressure had little effect. Thus, the high pressure condition could be replaced by low pressure to reduce the difficulty of the test. Finally, the relation of the coefficients "alpha" between the cold flow and hot fire was got.

  11. Ion temperature profile stiffness: non-linear gyrokinetic simulations and comparison with experiment

    NARCIS (Netherlands)

    Citrin, J.; Jenko, F.; Mantica, P.; Told, D.; Bourdelle, C.; Dumont, R.; Garcia, J.; Haverkort, J. W.; Hogeweij, G. M. D.; Johnson, T.; Pueschel, M. J.

    2014-01-01

    Recent experimental observations at JET show evidence of reduced ion temperature profile stiffness. An extensive set of nonlinear gyrokinetic simulations are performed based on the experimental discharges, investigating the physical mechanism behind the observations. The impact on the ion heat flux

  12. Experimental study on the adsorptive-distillation for dehydration of ethanol-water mixture using natural and synthetic zeolites

    Science.gov (United States)

    Megawati, Wicaksono, D.; Abdullah, M. S.

    2017-03-01

    This research studied adsorptive-distillation (AD) for dehydration of ethanol-water mixture using natural and synthetic zeolites as adsorbent for ethanol purification. Especially, the effect of purification time is recorded and studied to evaluate performance of designed AD equipment. This AD was performed in a batch condition using boiling flask covered with heating mantle and it was maintained at 78°C temperature and 1 atm pressure. The initial ethanol volume was 300 mL with 93.8% v/v concentration. The synthetic zeolite type used was zeolite 3A. The flowed vapour was condensed using water as a cooling medium. Every 5 minutes of time duration the samples were collected until the vapour could not be condensed in that condition and then be analyzed its concentration using Gas-Chromatography. Experiment shows that the designed AD equipment could increase ethanol concentration at first 5 minutes with highest ethanol concentration achieved using synthetic zeolite (97.47% v/v). However, ethanol concentration from AD process using natural zeolite only reached 96.5% v/v. Thus, synthetic zeolite as adsorbent could pass azeotropic point, but natural zeolite fail. The ratio of adsorbed water per adsorbent for natural and synthetic zeolites are about 0.023 and 0.056 gwater/gads, respectively, at 50 minutes of time. Finally, synthetic zeolite (at 55 minutes the value of C/C0 is about 0.85 and the average outlet water concentration is 4.70 mole/L) as adsorbent for AD of ethanol water is better than natural zeolite (at 55 minutes the value of C/C0 is about 0.63 and the average outlet water concentration is 6.43 mole/L).

  13. Deformation-induced dehydration structures in the Nankai accretionary prism

    Science.gov (United States)

    Famin, V.; Byrne, T.; Lewis, J. C.; Kanagawa, K.; Behrmann, J.; Iodp 314/315/316 Scientists, E.

    2008-12-01

    This study investigates the chemical changes caused by deformation in the hanging wall of a major, probably seismogenic thrust fault in the Kumano forearc basin, Nankai Trough. In cores from IODP Expedition 315 (site C0001), the clay sediments display numerous deformation structures including tilted beddings, decimeter scale faults and shear zones with normal or thrust offsets, and clusters of parallel curviplanar veins interpreted as earthquake-induced dewatering structures. Curviplanar veins are often observed to merge into small oblique shear zones with millimeter offsets, or to branch on larger shear zones with a ~30° angle. This suggests that some shear zones may form by the coalescence of veins. Curviplanar veins and shear zones appear darker than the surrounding clay at the macroscopic observation scale, and brighter and therefore denser under CT-scan imaging. At the micro-scale, clay has a preferred crystallographic orientation in the deformation structures and no preferred orientation outside. Electron probe micro-analysis reveals that the dark material has a higher sum of major elements (65-80 wt%), i.e. a lower volatile content (assumed to be mostly water) than the host sediment (50-60 wt%). All the major elements are equally enriched in proportion to the volatile depletion. Mass balance calculation indicates that a 20-30 wt% water loss is required to account for chemical change in the deformation microstructures. The water loss may be due to clay dehydration or to pore collapse. Shear zones are equally dehydrated as the curviplanar veins from the mass balance standpoint. In 1 m3 of sediment, a deformed volume of 1 % should produce about 6.2 L of water. Given the low permeability of the sediment, dehydration may increase the pore pressure and enhance further deformation. Deformation localization would be self-sustained by fluid overpressure, suggesting that dewatering veins may evolve into larger deformation structures after an earthquake.

  14. Impact of dehydration on a full body resistance exercise protocol.

    Science.gov (United States)

    Kraft, Justin A; Green, James M; Bishop, Phillip A; Richardson, Mark T; Neggers, Yasmin H; Leeper, James D

    2010-05-01

    This study examined effects of dehydration on a full body resistance exercise workout. Ten males completed two trials: heat exposed (with 100% fluid replacement) (HE) and dehydration (approximately 3% body mass loss with no fluid replacement) (DEHY) achieved via hot water bath (approximately 39 degrees C). Following HE and DEHY, participants performed three sets to failure (using predetermined 12 repetition maximum) of bench press, lat pull down, overhead press, barbell curl, triceps press, and leg press with a 2-min recovery between each set and 2 min between exercises. A paired t test showed total repetitions (all sets combined) were significantly lower for DEHY: (144.1 +/- 26.6 repetitions) versus HE: (169.4 +/- 29.1 repetitions). ANOVAs showed significantly lower repetitions (approximately 1-2 repetitions on average) per exercise for DEHY versus HE (all exercises). Pre-set rate of perceived exertion (RPE) and pre-set heart rate (HR) were significantly higher [approximately 0.6-1.1 units on average in triceps press, leg press, and approached significance in lat pull down (P = 0.14) and approximately 6-13 b min(-1) on average in bench press, lat pull down, triceps press, and approached significance for overhead press (P = 0.10)] in DEHY versus HE. Session RPE difference approached significance (DEHY: 8.6 +/- 1.9, HE: 7.4 +/- 2.3) (P = 0.12). Recovery HR was significantly higher for DEHY (116 +/- 15 b min(-1)) versus HE (105 +/- 13 b min(-1)). Dehydration (approximately 3%) impaired resistance exercise performance, decreased repetitions, increased perceived exertion, and hindered HR recovery. Results highlight the importance of adequate hydration during full body resistance exercise sessions.

  15. Economic consequences of improved temperature forecasts: An experiment with the Florida citrus growers (control group results). [weather forecasting

    Science.gov (United States)

    1977-01-01

    A demonstration experiment is being planned to show that frost and freeze prediction improvements are possible utilizing timely Synchronous Meteorological Satellite temperature measurements and that this information can affect Florida citrus grower operations and decisions. An economic experiment was carried out which will monitor citrus growers' decisions, actions, costs and losses, and meteorological forecasts and actual weather events and will establish the economic benefits of improved temperature forecasts. A summary is given of the economic experiment, the results obtained to date, and the work which still remains to be done. Specifically, the experiment design is described in detail as are the developed data collection methodology and procedures, sampling plan, data reduction techniques, cost and loss models, establishment of frost severity measures, data obtained from citrus growers, National Weather Service, and Federal Crop Insurance Corp., resulting protection costs and crop losses for the control group sample, extrapolation of results of control group to the Florida citrus industry and the method for normalization of these results to a normal or average frost season so that results may be compared with anticipated similar results from test group measurements.

  16. Aqueous geochemistry of low molecular weight hydrocarbons at elevated temperatures and pressures: constraints from mineral buffered laboratory experiments

    Science.gov (United States)

    Seewald, Jeffrey S.

    2001-05-01

    Organic matter, water, and minerals coexist at elevated temperatures and pressures in sedimentary basins and participate in a wide range of geochemical processes that includes the generation of oil and natural gas. A series of laboratory experiments were conducted at 300 to 350°C and 350 bars to examine chemical interactions involving low molecular weight aqueous hydrocarbons with water and Fe-bearing minerals under hydrothermal conditions. Mineral buffers composed of hematite-magnetite-pyrite, hematite-magnetite, and pyrite-pyrrhotite-magnetite were added to each experiment to fix the redox state of the fluid and the activity of reduced sulfur species. During each experiment the chemical system was externally modified by addition of ethene, ethane, propene, 1-butene, or n-heptane, and variations in the abundance of aqueous organic species were monitored as a function of time and temperature. Results of the experiments indicate that decomposition of aqueous n-alkanes proceeds through a series of oxidation and hydration reactions that sequentially produce alkenes, alcohols, ketones, and organic acids as reaction intermediaries. Organic acids subsequently undergo decarboxylation and/or oxidation reactions to form carbon dioxide and shorter chain saturated hydrocarbons. This alteration assemblage is compositionally distinct from that produced by thermal cracking under anhydrous conditions, indicating that the presence of water and minerals provide alternative reaction pathways for the decomposition of hydrocarbons. The rate of hydrocarbon oxidation decreases substantially under reducing conditions and in the absence of catalytically active aqueous sulfur species. These results represent compelling evidence that the stability of aqueous hydrocarbons at elevated temperatures in natural environments is not a simple function of time and temperature alone. Under the appropriate geochemical conditions, stepwise oxidation represents a mechanism for the decomposition of low

  17. The impact of sea surface temperature bias on equatorial Atlantic interannual variability in partially coupled model experiments

    Science.gov (United States)

    Ding, Hui; Greatbatch, Richard J.; Latif, Mojib; Park, Wonsun

    2015-07-01

    We examine the impact of sea surface temperature (SST) bias on interannual variability during boreal summer over the equatorial Atlantic using two suites of partially coupled model (PCM) experiments with and without surface heat flux correction. In the experiments, surface wind stress anomalies are specified from observations while the thermodynamic coupling between the atmospheric and oceanic components is still active as in the fully coupled model. The results show that the PCM can capture around 50% of the observed variability associated with the Atlantic Niño from 1958 to 2013, but only when the bias is substantially reduced using heat flux correction, with no skill otherwise. We further show that ocean dynamics explain a large part of the SST variability in the eastern equatorial Atlantic in both observations (50-60%) and the PCM experiments (50-70%) with heat flux correction, implying that the seasonal predictability potential may be higher than currently thought.

  18. RCCS Experiments and Validation for High Temperature Gas-Cooled Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Chang Oh; Cliff Davis; Goon C. Park

    2007-09-01

    A reactor cavity cooling system (RCCS), an air-cooled helical coil RCCS unit immersed in the water pool, was proposed to overcome the disadvantages of the weak cooling ability of air-cooled RCCS and the complex structure of water-cooled RCCS for the high temperature gas-cooled reactor (HTGR). An experimental apparatus was constructed to investigate the various heat transfer phenomena in the water pool type RCCS, such as the natural convection of air inside the cavity, radiation in the cavity, the natural convection of water in the water pool and the forced convection of air in the cooling pipe. The RCCS experimental results were compared with published correlations. The CFX code was validated using data from the air-cooled portion of the RCCS. The RELAP5 code was validated using measured temperatures from the reactor vessel and cavity walls.

  19. Intercomparison of stratospheric ozone and temperature profiles during the October 2005 Hohenpeissenberg Ozone Profiling Experiment (HOPE)

    Science.gov (United States)

    Steinbrecht, W.; McGee, T. J.; Twigg, L. W.; Claude, H.; Schönenborn, F.; Sumnicht, G. K.; Silbert, D.

    2009-01-01

    Thirteen clear nights in October 2005 allowed successful intercomparison of the stationary lidar operated since 1987 by the German Weather Service (DWD) at Hohenpeissenberg (47.8° N, 11.0° E) with the Network for the Detection of Atmospheric Composition Change (NDACC) travelling standard lidar operated by NASA's Goddard Space Flight Center. Both lidars provide ozone profiles in the stratosphere, and temperature profiles in the strato- and mesosphere. Additional ozone profiles came from on-site Brewer/Mast ozonesondes, additional temperature profiles from Vaisala RS92 radiosondes launched at Munich (65 km north-east), and from operational analyses by the US National Centers for Environmental Prediction (NCEP). The intercomparison confirmed a low bias for ozone from the DWD lidar in the 33 to 43 km region, by up to 10%. This bias is caused by the DWD ozone algorithm. It will be removed in a future version. Between 20 and 33 km, agreement between both lidars, and ozonesondes below 30 km, is good with ozone differences less than 3 to 5%. Results are consistent with previous comparisons of the DWD lidar with SAGE, GOMOS and other satellite instruments. The intercomparison did uncover a 290 m upward shift of the DWD lidar data. When this shift is removed, agreement with ozone from the NASA lidar improves below 20 km, with remaining differences usually less than 5%, and not statistically significant. Precision (repeatability) for the lidar ozone data is better than 5% between 20 and 40 km altitude, dropping to 10% near 45 km, and 50% near 50 km. Temperature from the DWD lidar has a 1 to 2 K cold bias from 30 to 65 km against the NASA lidar, and a 2 to 4 K cold bias against radiosondes and NCEP. This is consistent with previous intercomparisons against NCEP or radiosondes. The cold bias against the NASA lidar disappears when the DWD lidar data are corrected for the afore-mentioned 290 m range error, and more appropriate values for the Earth's gravity acceleration are

  20. Intercomparison of stratospheric ozone and temperature profiles during the October 2005 Hohenpeissenberg Ozone Profiling Experiment (HOPE

    Directory of Open Access Journals (Sweden)

    W. Steinbrecht

    2009-01-01

    Full Text Available Thirteen clear nights in October 2005 allowed successful intercomparison of the stationary lidar operated since 1987 by the German Weather Service (DWD at Hohenpeissenberg (47.8° N, 11.0° E with the Network for the Detection of Atmospheric Composition Change (NDACC travelling standard lidar operated by NASA's Goddard Space Flight Center. Both lidars provide ozone profiles in the stratosphere, and temperature profiles in the strato- and mesosphere. Additional ozone profiles came from on-site Brewer/Mast ozonesondes, additional temperature profiles from Vaisala RS92 radiosondes launched at Munich (65 km north-east, and from operational analyses by the US National Centers for Environmental Prediction (NCEP. The intercomparison confirmed a low bias for ozone from the DWD lidar in the 33 to 43 km region, by up to 10%. This bias is caused by the DWD ozone algorithm. It will be removed in a future version. Between 20 and 33 km, agreement between both lidars, and ozonesondes below 30 km, is good with ozone differences less than 3 to 5%. Results are consistent with previous comparisons of the DWD lidar with SAGE, GOMOS and other satellite instruments. The intercomparison did uncover a 290 m upward shift of the DWD lidar data. When this shift is removed, agreement with ozone from the NASA lidar improves below 20 km, with remaining differences usually less than 5%, and not statistically significant. Precision (repeatability for the lidar ozone data is better than 5% between 20 and 40 km altitude, dropping to 10% near 45 km, and 50% near 50 km. Temperature from the DWD lidar has a 1 to 2 K cold bias from 30 to 65 km against the NASA lidar, and a 2 to 4 K cold bias against radiosondes and NCEP. This is consistent with previous intercomparisons against NCEP or radiosondes. The cold bias against the NASA lidar disappears when the DWD lidar data are corrected for the afore-mentioned 290 m range error, and more appropriate values for the Earth's gravity

  1. Dependence of the muon intensity on the atmospheric temperature measured by the GRAPES-3 experiment

    Science.gov (United States)

    Arunbabu, K. P.; Ahmad, S.; Chandra, A.; Dugad, S. R.; Gupta, S. K.; Hariharan, B.; Hayashi, Y.; Jagadeesan, P.; Jain, A.; Jhansi, V. B.; Kawakami, S.; Kojima, H.; Mohanty, P. K.; Morris, S. D.; Nayak, P. K.; Oshima, A.; Rao, B. S.; Reddy, L. V.; Shibata, S.; Tanaka, K.; Zuberi, M.

    2017-09-01

    The large area (560 m2) GRAPES-3 tracking muon telescope has been operating uninterruptedly at Ooty, India since 2001. Every day, it records 4 × 109 muons of ≥1 GeV with an angular resolution of ∼4°. The variation of atmospheric temperature affects the rate of decay of muons produced by the galactic cosmic rays (GCRs), which in turn modulates the muon intensity. By analyzing the GRAPES-3 data of six years (2005-2010), a small (amplitude ∼0.2%) seasonal variation (1 year (Yr) period) in the intensity of muons could be measured. The effective temperature 'Teff' of the upper atmosphere also displays a periodic variation with an amplitude of ∼1 K which was responsible for the observed seasonal variation in the muon intensity. At GeV energies, the muons detected by the GRAPES-3 are expected to be anti-correlated with Teff. The anti-correlation between the seasonal variation of Teff, and the muon intensity was used to measure the temperature coefficient αT by fast Fourier transform (FFT) technique. The magnitude of αT was found to scale with the assumed attenuation length 'λ' of the hadrons in the range λ = 80-180 g cm-2. However, the magnitude of the correction in the muon intensity was found to be almost independent of the value of λ used. For λ = 120 g cm-2 the value of temperature coefficient αT was found to be (- 0.17 ± 0.02)% K-1.

  2. Airflow study of pathologic larynges using a constant temperature anemometer: further experience.

    Science.gov (United States)

    Kitajima, K; Fujita, F

    1992-08-01

    Phonatory airflow was recorded in 361 laryngeal disease patients and 59 normal subjects by using a constant temperature anemometer to measure Isshiki's proposed parameter, the AC/DC percentage. The pathologic groups displayed AC/DC percentage values smaller than those of the normal group. The value differentials observed among the various diseases suggest that the AC/DC percentage may reflect the vibrational capacity of the vocal cords.

  3. Influence of osmotic dehydration on ascorbic acid loss in pickled dry peppers (Capsicum chinense

    Directory of Open Access Journals (Sweden)

    Tissiane Mayara da Silva

    2012-10-01

    Full Text Available The objective of this work was (1 to develop a dehydrated pepper with 45% humidity, determining the drying curves for pepper, with and without osmotic pre-treatment and (2 to evaluate the influence of both drying and osmotic treatment on the content ascorbic acid (vitamin C in fresh pepper and pepper with 45% humidity. The experiments were carried out using the peppers cut in half, with and without osmotic pre-treatment, followed by drying in an oven at 70 ºC. The results showed that the osmotic pretreatment did not influence the retention of ascorbic acid during the drying of pepper. The sensory analysis regarding the color, flavor, and texture attributes revealed that there was no difference in the acceptability.

  4. Novel thermally cross-linked polyimide membranes for ethanol dehydration via pervaporation

    KAUST Repository

    Xu, Sheng

    2015-12-01

    © 2015 Elsevier B.V. In this work, two novel carboxyl-containing polyimides, 2,2\\'-bis(3,4-dicarboxyphenyl) hexafluoropropane dianhydride-4,4\\'-diaminodiphenylmethane/3,5-diaminobenzoic acid (6FDA-MDA/DABA, FMD) and 3,3\\',4,4\\'-benzophenone tetracarboxylic dianhydride-4,4\\'-diaminodiphenylmethane/3,5-diaminobenzoic acid (BTDA-MDA/DABA, BMD), are synthesized via chemical and thermal imidization methods, respectively, and employed as pervaporation membranes for ethanol dehydration. Chemical structures of the two polyimides are examined by FTIR and TGA to confirm the successful synthesis. A post thermal treatment of the polyimide membranes with the temperature range of 250 to 400. °C is applied, and its effects on the membrane morphology and separation performance are studied and characterized by FTIR, TGA, WXRD, solubility and sorption test. It is believed that the thermal treatment of the carboxyl-containing polyimide membrane at a relative low temperature only leads to the physical annealing, while it may cause the decarboxylation-induced cross-linking at a higher temperature. In addition, the operation temperature in pervaporation is also varied and shown to be an important factor to affect the final membrane performance. Performance benchmarking shows that the developed polyimide membranes both have superior pervaporation performance to most other flat-sheet dense membranes. This work is believed to shed useful insights on polyimide membranes for pervaporation applications.

  5. Nanotube-based source of charges for experiments with solid helium at low temperatures

    Science.gov (United States)

    Borisenko, D. N.; Walmsley, P. M.; Golov, A. I.; Kolesnikov, N. N.; Kotov, Yu. V.; Levchenko, A. A.; Mezhov-Deglin, L. P.; Fear, M. J.

    2015-07-01

    Methods of preparation of the field-emission sources of charges from carbon nanotubes suitable for study of injected charges in solid helium at low temperatures T nanotubes onto a flat copper substrate or by mechanical rubbing of nanotubes into porous metal surface. The test study of the voltage-current characteristics of a diode cell with the nanotube source in superfluid He II have shown that at voltages above 120 V one can observe a relatively large current I ≥ 10-13 A of negative charges in liquid helium. The field and temperature dependences of positive and negative currents in solid 4He were studied in samples grown by the blocked capillary technique. Usage of the nanotube based source of injected charges had permitted us for the first time to observe motion of the positive charges in solid helium at temperatures below 0.1 K. The current-voltage dependence could be described by a power law I ˜Uα , with the value of the exponent α ≫ 2, much higher than what one would expect for the regime of space charge limited currents.

  6. A geometry-based approach to determining time-temperature superposition shifts in aging experiments

    Energy Technology Data Exchange (ETDEWEB)

    Maiti, Amitesh

    2015-12-21

    A powerful way to expand the time and frequency range of material properties is through a method called time-temperature superposition (TTS). Traditionally, TTS has been applied to the dynamical mechanical and flow properties of thermo-rheologically simple materials, where a well-defined master curve can be objectively and accurately obtained by appropriate shifts of curves at different temperatures. However, TTS analysis can also be useful in many other situations where there is scatter in the data and where the principle holds only approximately. In such cases, shifting curves can become a subjective exercise and can often lead to significant errors in the long-term prediction. This mandates the need for an objective method of determining TTS shifts. Here, we adopt a method based on minimizing the “arc length” of the master curve, which is designed to work in situations where there is overlapping data at successive temperatures. We examine the accuracy of the method as a function of increasing noise in the data, and explore the effectiveness of data smoothing prior to TTS shifting. We validate the method using existing experimental data on the creep strain of an aramid fiber and the powder coarsening of an energetic material.

  7. Ultrasound-assisted osmotic dehydration and convective drying of apples: Process kinetics and quality issues

    OpenAIRE

    Mierzwa Dominik; Kowalski Stefan J.

    2016-01-01

    The aim of the present theme issue was to study the influence of ultrasound enhancement on the kinetics of osmotic dehydration and the effect of convective drying from the point of view of drying time and quality of dried products. Apple fruit was used as the experimental material. The kinetics of osmotic dehydration with (UAOD) and without (OD) ultrasound enhancement were examined for 40% fructose and sorbitol solutions. The effective dehydration time of osmotic process was determined. Preli...

  8. Costs of sludges dehydration; Costes derivados de la deshidratacion de fangos

    Energy Technology Data Exchange (ETDEWEB)

    Bermudez, S.; Lafuente, C. [Universidad de Antonio de Nebrija (Spain); Rodriguez, M. E. [Universidad Politecnica de Madrid (Spain)

    1999-11-01

    The objective of this work has been the determination of the system of dehydration more suitable from an economical and environmental point of view. In Spain the system of dehydration more utilized is the filter strip that represents the 61%, consecutive from the centrifugal that supposes the 19%, and as the Comunities of greater production of mire dehydrated are Madrid, Cataluna and Valencia; they have been those that have defined the frame object of study. (Author) 35 refs.

  9. Dehydration-specific induction of hydrophilic protein genes in the anhydrobiotic nematode Aphelenchus avenae.

    Science.gov (United States)

    Browne, John A; Dolan, Katharine M; Tyson, Trevor; Goyal, Kshamata; Tunnacliffe, Alan; Burnell, Ann M

    2004-08-01

    Some organisms can survive exposure to extreme desiccation by entering a state of suspended animation known as anhydrobiosis. The free-living nematode Aphelenchus avenae can be induced to enter the anhydrobiotic state by exposure to a moderate reduction in relative humidity. During this preconditioning period, the nematode accumulates large amounts of the disaccharide trehalose, which is thought to be necessary, but not sufficient, for successful anhydrobiosis. To identify other adaptations that are required for anhydrobiosis, we developed a novel SL1-based mRNA differential display technique to clone genes that are upregulated by dehydration in A. avenae. Three such genes, Aav-lea-1, Aav-ahn-1, and Aav-glx-1, encode, respectively, a late embryogenesis abundant (LEA) group 3 protein, a novel protein that we named anhydrin, and the antioxidant enzyme glutaredoxin. Strikingly, the predicted LEA and anhydrin proteins are highly hydrophilic and lack significant secondary structure in the hydrated state. The dehydration-induced upregulation of Aav-lea-1 and Aav-ahn-1 was confirmed by Northern hybridization and quantitative PCR experiments. Both genes were also upregulated by an osmotic upshift, but not by cold, heat, or oxidative stress. Experiments to investigate the relationship between mRNA levels and protein expression for these genes are in progress. LEA proteins occur commonly in plants, accumulating during seed maturation and desiccation stress; the presence of a gene encoding an LEA protein in an anhydrobiotic nematode suggests that some mechanisms of coping with water loss are conserved between plants and animals.

  10. Dehydration studies using a novel multichamber microscale fluid bed dryer with in-line near-infrared measurement

    DEFF Research Database (Denmark)

    Räsänen, Eetu; Rantanen, Jukka; Mannermaa, Jukka-Pekka

    2003-01-01

    of solid materials. The temperature and the moisture content of the process air were demonstrated to be significant factors for the solid-state stability of theophylline. The presented setup is a material and cost-saving approach for studying the influence of different process parameters on dehydration....... The materials studied were disodium hydrogen phosphates with three different levels of hydrate water and wet theophylline granules. Measured process parameters of fluid bed drying were logged, including in-line NIR signals. Off-line analyses consisted of X-ray powder diffraction patterns, Fourier transform NIR...

  11. Six-axis multi-anvil press for high-pressure, high-temperature neutron diffraction experiments.

    Science.gov (United States)

    Sano-Furukawa, A; Hattori, T; Arima, H; Yamada, A; Tabata, S; Kondo, M; Nakamura, A; Kagi, H; Yagi, T

    2014-11-01

    We developed a six-axis multi-anvil press, ATSUHIME, for high-pressure and high-temperature in situ time-of-flight neutron powder diffraction experiments. The press has six orthogonally oriented hydraulic rams that operate individually to compress a cubic sample assembly. Experiments indicate that the press can generate pressures up to 9.3 GPa and temperatures up to 2000 K using a 6-6-type cell assembly, with available sample volume of about 50 mm(3). Using a 6-8-type cell assembly, the available conditions expand to 16 GPa and 1273 K. Because the six-axis press has no guide blocks, there is sufficient space around the sample to use the aperture for diffraction and place an incident slit, radial collimators, and a neutron imaging camera close to the sample. Combination of the six-axis press and the collimation devices realized high-quality diffraction pattern with no contamination from the heater or the sample container surrounding the sample. This press constitutes a new tool for using neutron diffraction to study the structures of crystals and liquids under high pressures and temperatures.

  12. Six-axis multi-anvil press for high-pressure, high-temperature neutron diffraction experiments

    Energy Technology Data Exchange (ETDEWEB)

    Sano-Furukawa, A., E-mail: sano.asami@jaea.go.jp; Hattori, T. [Quantum Beam Science Center, Japan Atomic Energy Agency, Ibaraki 319-1195 (Japan); J-PARC Center, Japan Atomic Energy Agency, Ibaraki 319-1195 (Japan); Arima, H. [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Yamada, A. [The University of Shiga Prefecture, Shiga 522-8533 (Japan); Tabata, S.; Kondo, M.; Nakamura, A. [Sumitomo Heavy Industries Co., Ltd., Ehime 792-0001 (Japan); Kagi, H.; Yagi, T. [Geochemical Research Center, Graduate School of Science, The University of Tokyo, Tokyo 113-0033 (Japan)

    2014-11-15

    We developed a six-axis multi-anvil press, ATSUHIME, for high-pressure and high-temperature in situ time-of-flight neutron powder diffraction experiments. The press has six orthogonally oriented hydraulic rams that operate individually to compress a cubic sample assembly. Experiments indicate that the press can generate pressures up to 9.3 GPa and temperatures up to 2000 K using a 6-6-type cell assembly, with available sample volume of about 50 mm{sup 3}. Using a 6-8-type cell assembly, the available conditions expand to 16 GPa and 1273 K. Because the six-axis press has no guide blocks, there is sufficient space around the sample to use the aperture for diffraction and place an incident slit, radial collimators, and a neutron imaging camera close to the sample. Combination of the six-axis press and the collimation devices realized high-quality diffraction pattern with no contamination from the heater or the sample container surrounding the sample. This press constitutes a new tool for using neutron diffraction to study the structures of crystals and liquids under high pressures and temperatures.

  13. Process for dehydration of oregano using propane gas as fuel

    Directory of Open Access Journals (Sweden)

    Carlos O. Velásquez-Santos

    2014-08-01

    Full Text Available The article describes two important issues, the first is the process to design, implement and validate a mechanical dryer of oregano, using propane gas as fuel, and the second is the cost of the process of dehydrated, taking into account the cost of electric energy consumption by the fan and the cost of propane gas consumption by the heat exchanger. To achieve this, it was necessary review the state of the art and the study of the raw material (oregano, were established as premises of design the necessary technical specifications and the variables involved in the process, using conceptual methods and simulation to ensure that it complies with the ISO standard 7925:1999, which defines the requirements for the marketing of dried oregano and processed. Emphasis was made on the percentage of moisture that is 10%, the moisture of the product was found by the azeotropic distillation method, subsequently was validated the functionality and efficiency, comparing the results from an experimental design, then it was obtained the drying curve of oregano with the prototype of drying and it was checked if it meets ISO 7925:1999 standard and the NTC 4423 standard in order to obtain a final product dehydrated with the percentage of humidity appropriate.

  14. Structural and functional insights into asymmetric enzymatic dehydration of alkenols.

    Science.gov (United States)

    Nestl, Bettina M; Geinitz, Christopher; Popa, Stephanie; Rizek, Sari; Haselbeck, Robert J; Stephen, Rosary; Noble, Michael A; Fischer, Max-Philipp; Ralph, Erik C; Hau, Hoi Ting; Man, Henry; Omar, Muhiadin; Turkenburg, Johan P; van Dien, Stephen; Culler, Stephanie J; Grogan, Gideon; Hauer, Bernhard

    2017-03-01

    The asymmetric dehydration of alcohols is an important process for the direct synthesis of alkenes. We report the structure and substrate specificity of the bifunctional linalool dehydratase isomerase (LinD) from the bacterium Castellaniella defragrans that catalyzes in nature the hydration of β-myrcene to linalool and the subsequent isomerization to geraniol. Enzymatic kinetic resolutions of truncated and elongated aromatic and aliphatic tertiary alcohols (C5-C15) that contain a specific signature motif demonstrate the broad substrate specificity of LinD. The three-dimensional structure of LinD from Castellaniella defragrans revealed a pentamer with active sites at the protomer interfaces. Furthermore, the structure of LinD in complex with the product geraniol provides initial mechanistic insights into this bifunctional enzyme. Site-directed mutagenesis confirmed active site amino acid residues essential for its dehydration and isomerization activity. These structural and mechanistic insights facilitate the development of hydrating catalysts, enriching the toolbox for novel bond-forming biocatalysis.

  15. Crystal structures of phosphoketolase: thiamine diphosphate-dependent dehydration mechanism.

    Science.gov (United States)

    Suzuki, Ryuichiro; Katayama, Takane; Kim, Byung-Jun; Wakagi, Takayoshi; Shoun, Hirofumi; Ashida, Hisashi; Yamamoto, Kenji; Fushinobu, Shinya

    2010-10-29

    Thiamine diphosphate (ThDP)-dependent enzymes are ubiquitously present in all organisms and catalyze essential reactions in various metabolic pathways. ThDP-dependent phosphoketolase plays key roles in the central metabolism of heterofermentative bacteria and in the pentose catabolism of various microbes. In particular, bifidobacteria, representatives of beneficial commensal bacteria, have an effective glycolytic pathway called bifid shunt in which 2.5 mol of ATP are produced per glucose. Phosphoketolase catalyzes two steps in the bifid shunt because of its dual-substrate specificity; they are phosphorolytic cleavage of fructose 6-phosphate or xylulose 5-phosphate to produce aldose phosphate, acetyl phosphate, and H(2)O. The phosphoketolase reaction is different from other well studied ThDP-dependent enzymes because it involves a dehydration step. Although phosphoketolase was discovered more than 50 years ago, its three-dimensional structure remains unclear. In this study we report the crystal structures of xylulose 5-phosphate/fructose 6-phosphate phosphoketolase from Bifidobacterium breve. The structures of the two intermediates before and after dehydration (α,β-dihydroxyethyl ThDP and 2-acetyl-ThDP) and complex with inorganic phosphate give an insight into the mechanism of each step of the enzymatic reaction.

  16. A process and assembly for desalinating and dehydrating crude oils

    Energy Technology Data Exchange (ETDEWEB)

    Popp, V.V.; Fotescu, L.; Mihalache, I.; Neagu, R.; Suditu, I.N.; Tirboiu, D.

    1981-08-05

    A process is patented for desalinating and dehydrating crude oils by washing them with hot water (the assembly contains a demulsifier) for several stages depending on the salt content and a free water separating stage, after which an optimum dose of demulsifier is injected into the oil; the oil is heated up and injected into a settling tank where a coalescent layer if formed (depending on the type of oil). Coalescence can be conducted in the heat exchanger which is located before the settling tank and from which the hot water recirculates for washing. The treated oil, which may contain water and volatile components, can be injected into the stripper in a heated or unheated state. In the stripper, the oil makes contact with heated gas in a counterflow, which extracts the steam and the volatile hydrocarbons. The dehydrated oil is removed from the bottom of the stripper; steam and hydrocarbons move to the top of the stripper where they condense. The hydrocarbons are passed on for further use. The corresponding device which operates in the described manner is also patented.

  17. Application of Geotextile Bag Dehydrated Soil to Dike Construction

    Institute of Scientific and Technical Information of China (English)

    朱平; 闫澍旺; 刘润

    2004-01-01

    Using geotextile bag dehydrated soil to construct dikes for land reclamation to substitute conventional straw bags is an urgent need in Tianjin New Harbor, China. This paper introduces the method to build a dike for hydraulic filling. The soil for filling the geotextile bags was tested in wave trench; the stress developed during construction was calculated by establishing a numerical model and compared with the tensile strength of the geotextile; the stability and settlement of the dike were estimated by performing centrifuge tests. Through this study, the following information was obtained: 1) The cohesionless silt with plasticity index less than 10 is suitable for filling the geotextile bags. The geotextile bag dehydrated soil consolidated very quickly even under the action of wave force. 2) A numerical model was devised to find the limit injection height and to calculate the tensile stress developed in the geotextile bags when they were piled up to form the dike. The calculated stress was compared with the strength of the geotextile, showing that the design is reasonably safe. 3)