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Sample records for dehydration

  1. Dehydration

    MedlinePlus

    ... to be a little more careful. Signs of dehydration in adults include Being thirsty Urinating less often ... skin Feeling tired Dizziness and fainting Signs of dehydration in babies and young children include a dry ...

  2. Onion dehydration

    SciTech Connect

    Lund, J.W.; Lienau, P.J.

    1994-07-01

    This article describes the onion dehydration process as generally practiced in the United States. The actual processing steps from harvest to final product, and geothermal applications for power production and energy requirements in the dehydration industry are discussed. A design of a dehydrator converted to geothermal energy usage is included.

  3. Onion dehydration

    SciTech Connect

    Lund, J.W.

    1995-12-31

    Onion dehydration consists of a continuous operation, belt conveyor using fairly low-temperature hot air from 38-104{degrees}C (100 to 200{degrees}F). Typical processing plants will handle 4500 kg (10,000 pounds) of raw product per hour (single line), reducing the moisture from around 83 % to 4 % (680 to 820 kg - 1,500 to 1,800 pounds finished product). An example of a geothermal processing plant is Integrate Ingredients at Empire, Nevada, in the San Emidio Desert. A total of 6.3 million kg (14 million pounds) of dry product are produced annually: 60% onion and 40% garlic. A 130{degrees}C (266{degrees}F) well provide the necessary heat for the plant.

  4. First Aid: Dehydration

    MedlinePlus

    ... Story" 5 Things to Know About Zika & Pregnancy First Aid: Dehydration KidsHealth > For Parents > First Aid: Dehydration Print A A A Text Size Dehydration ... MORE ON THIS TOPIC Summer Safety Heat Illness First Aid: Heat Illness Sun Safety Dehydration Diarrhea Vomiting Word! ...

  5. Thirst, Drinking Behavior, And Dehydration

    NASA Technical Reports Server (NTRS)

    Greenleaf, John

    1996-01-01

    Report describes review of physiological mechanisms of involuntary dehydration. Researchers considered cellular dehydration and effects of sodium on thirst, as well as extracellular dehydration and restoration of vascular volume, effects of renin on thirst, and effects of heat.

  6. Dehydration (For Teens)

    MedlinePlus

    ... En Español Making a Change – Your Personal Plan Hot Topics Meningitis Choosing Your Mood Prescription Drug Abuse ... from lots of physical activity, especially on a hot day. Even mild dehydration can affect an athlete's ...

  7. Sports Dehydration Safety Tips

    MedlinePlus

    ... drinking plenty of fluids. Dehydration occurs when a body loses more water than it takes in (such as through sweating). ... Move the athlete to shade and cool the body with cold water. Have the athlete drink cool water, remove any ...

  8. Electrolyte Concentrates Treat Dehydration

    NASA Technical Reports Server (NTRS)

    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.

  9. Fruits and vegetables dehydration

    NASA Astrophysics Data System (ADS)

    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.

  10. Onion dehydration: a review.

    PubMed

    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. PMID:23729847

  11. Dehydrate ethanol without distillation

    SciTech Connect

    Not Available

    1993-10-01

    Usina da Pedra (Serrana, state of Sao Paulo, Brazil) produces 60 million gal/yr of ethanol in 180 operating days. Until this year, the plant made 96 vol.% ethanol that is used as automotive fuel, and absolute ethanol (99.5 vol. %), which is blended with gasoline. Water is the remainder in both products. The ethanol is produced from the fermentation of sugar cane, and distilled with benzene. Benzene lowers the boiling point of the ethanol-water mixture and ties up the water. In May, Usina da Pedra installed a process that dehydrates ethanol by adsorption, not distillation. A vapor-phase process containing molecular sieves, handles throughputs as high as 160,000 acfh and has a maximum capacity of 70 million gal/yr. In addition to generating safer products, the energy savings gained by switching from distillation to adsorption are significant. The adsorptive system requires input of only 2,900 Btu per gallon of ethanol; one-third the energy consumed by distillation systems that employ benzene or cyclohexane.

  12. Dehydration kinetics of shocked serpentine

    NASA Technical Reports Server (NTRS)

    Tyburczy, James A.; Ahrens, Thomas J.

    1988-01-01

    Experimental rates of dehydration of shocked and unshocked serpentine were determined using a differential scanning calorimetric technique. Dehydration rates in shocked serpentine are enhanced by orders of magnitude over corresponding rates in unshocked material, even though the impact experiments were carried out under conditions that inhibited direct impact-induced devolatilization. Extrapolation to temperatures of the Martian surface indicates that dehydration of shocked material would occur 20 to 30 orders of magnitude more rapidly than for unshocked serpentine. The results indicate that impacted planetary surfaces and associated atmospheres would reach chemical equilibrium much more quickly than calculations based on unshocked material would indicate, even during the earliest, coldest stages of accretion. Furthermore, it is suggested that chemical weathering of shocked planetary surfaces by solid-gas reactions would be sufficiently rapid that true equilibrium mineral assemblages should form.

  13. A small scale honey dehydrator.

    PubMed

    Gill, R S; Hans, V S; Singh, Sukhmeet; Pal Singh, Parm; Dhaliwal, S S

    2015-10-01

    A small scale honey dehydrator has been designed, developed, and tested to reduce moisture content of honey below 17 %. Experiments have been conducted for honey dehydration by using drying air at ambient temperature, 30 and 40 °C and water at 35, 40 and 45 °C. In this dehydrator, hot water has been circulated in a water jacket around the honey container to heat honey. The heated honey has been pumped through a sieve to form honey streams through which drying air passes for moisture removal. The honey streams help in increasing the exposed surface area of honey in contact with drying air, thus resulting in faster dehydration of honey. The maximum drying rate per square meter area of honey exposed to drying air was found to be 197.0 g/h-m(2) corresponding to the drying air and water temperature of 40 and 45 °C respectively whereas it was found to be minimum (74.8 g/h-m(2)) corresponding to the drying air at ambient temperature (8-17 °C) and water at 35 °C. The energy cost of honey moisture content reduction from 25.2 to 16.4 % was Rs. 6.20 to Rs. 17.36 (US $ 0.10 to US $ 0.28 (One US $ = 62.00 Indian Rupee on February, 2014) per kilogram of honey. PMID:26396418

  14. METHOD OF DEHYDRATING URANIUM TETRAFLUORIDE

    DOEpatents

    Davis, J.O.; Fogel, C.C.; Palmer, W.E.

    1962-12-18

    Drying and dehydration of aqueous-precipitated uranium tetrafluoride are described. The UF/sub 4/ which normally contains 3 to 4% water, is dispersed into the reaction zone of an operating reactor wherein uranium hexafluoride is being reduced to UF/sub 4/ with hydrogen. The water-containing UF/sub 4/ is dried and blended with the UF/sub 4/ produced in the reactor without interfering with the reduction reaction. (AEC)

  15. Dehydration

    NASA Astrophysics Data System (ADS)

    Friebele, Elaine

    The news that the Earth is losing 1,000 gallons of water every day is nothing for the planet's inhabitants to sweat, given the vast amount of water in the oceans. But this new information, gathered from measurements on the POLAR satellite, has shed new light on ways that water and other materials leave the atmosphere. The new data should also improve models of how the atmospheres of Earth and other planets evolve.Using a unique instrument to reduce electrical interference from the satellite, the research team took the first accurate high-altitude measurements of the polar wind—charged gas or plasma that escapes from Earth and its ionosphere through the poles. The team, headed by Los Alamos physicist Beth Nordholt, proved that the polar wind is one mechanism by which the atomic constituents of water vapor and other atmospheric gases are dragged outward from the ionosphere, where they spiral along the planet's magnet field lines. Sunlight breaks the water into ionized hydrogen and oxygen gases in the upper atmosphere.

  16. Dehydration

    MedlinePlus

    ... too much, for example, from exercising in hot weather Fever Vomiting or diarrhea Urinating too much (uncontrolled ... when you are well. Drink more when the weather is hot or you are exercising. If anyone ...

  17. A dehydration mechanism for the stratosphere

    NASA Technical Reports Server (NTRS)

    Danielsen, E. F.

    1982-01-01

    Although mean circulations are generally credited with dehydration of the earth's stratosphere, convective instability in the tropics converts mean circulations to small residuals of local convective circulations. The effects of large cumulonimbus which penetrate the stratosphere and form huge anvils in the lower stratosphere are discussed with respect to hydration and dehydration of the stratosphere. Radiative heating at anvil base combined with cooling at anvil top drives a dehydration engine considered essential to explain the dry stratosphere. Seasonal and longitudinal variations in dehydration potentials are examined with maximum potential attributed to Micronesian area during winter and early spring.

  18. Detecting dehydration in older people: useful tests.

    PubMed

    Hooper, Lee; Bunn, Diane

    Dehydration is common in older people, leading to longer hospital stays and increased disability and mortality. Health professionals can diagnose water-loss dehydration by taking a blood sample and measuring serum osmolality, but a less-invasive test would be useful. Evidence that tests, clinical signs or questions tested to date are useful when screening for dehydration in older people is limited. This article looks at known risk factors, signs and test for dehydration, and outlines evidence on how useful they have proven to be. Part 2 describes how a care home has used a multicomponent strategy to improve hydration. PMID:26455128

  19. Spectral effects of dehydration on phyllosilicates

    NASA Technical Reports Server (NTRS)

    Bruckenthal, E. A.; Singer, R. B.

    1987-01-01

    Six phyllosilicates were progressively dehydrated under controlled conditions in an effort to study the spectral effects of their dehydration. The spectra obtained at each level of hydration provide information that may be used in future spectroscopic observations of the planets, as well as a data set which compliments the existing body of terrestrial soil knowledge.

  20. Dehydration Accelerates Respiration in Postharvest Sugarbeet Roots

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sugarbeet (Beta vulgaris L.) roots lose water during storage and often become severely dehydrated after prolonged storage and at the outer regions of storage piles which have greater wind and sun exposure. Sucrose loss is known to be elevated in dehydrated roots, although the metabolic processes re...

  1. 7 CFR 929.11 - To can, freeze, or dehydrate.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE CRANBERRIES GROWN IN STATES OF... dehydrate. To can, freeze, or dehydrate means to convert cranberries into canned, frozen, or dehydrated cranberries or other cranberry products by any commercial process....

  2. 7 CFR 929.11 - To can, freeze, or dehydrate.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE CRANBERRIES GROWN IN STATES OF... dehydrate. To can, freeze, or dehydrate means to convert cranberries into canned, frozen, or dehydrated cranberries or other cranberry products by any commercial process....

  3. 7 CFR 929.11 - To can, freeze, or dehydrate.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... AGREEMENTS AND ORDERS; FRUITS, VEGETABLES, NUTS), DEPARTMENT OF AGRICULTURE CRANBERRIES GROWN IN STATES OF... dehydrate. To can, freeze, or dehydrate means to convert cranberries into canned, frozen, or dehydrated cranberries or other cranberry products by any commercial process....

  4. 7 CFR 929.11 - To can, freeze, or dehydrate.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... AGREEMENTS AND ORDERS; FRUITS, VEGETABLES, NUTS), DEPARTMENT OF AGRICULTURE CRANBERRIES GROWN IN STATES OF... dehydrate. To can, freeze, or dehydrate means to convert cranberries into canned, frozen, or dehydrated cranberries or other cranberry products by any commercial process....

  5. 7 CFR 929.11 - To can, freeze, or dehydrate.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE CRANBERRIES GROWN IN STATES OF... dehydrate. To can, freeze, or dehydrate means to convert cranberries into canned, frozen, or dehydrated cranberries or other cranberry products by any commercial process....

  6. Water-loss dehydration and aging.

    PubMed

    Hooper, Lee; Bunn, Diane; Jimoh, Florence O; Fairweather-Tait, Susan J

    2014-01-01

    This review defines water-loss and salt-loss dehydration. For older people serum osmolality appears the most appropriate gold standard for diagnosis of water-loss dehydration, but clear signs of early dehydration have not been developed. In older adults, lower muscle mass, reduced kidney function, physical and cognitive disabilities, blunted thirst, and polypharmacy all increase dehydration risk. Cross-sectional studies suggest a water-loss dehydration prevalence of 20-30% in this population. Water-loss dehydration is associated with higher mortality, morbidity and disability in older people, but evidence is still needed that this relationship is causal. There are a variety of ways we may be able to help older people reduce their risk of dehydration by recognising that they are not drinking enough, and being helped to drink more. Strategies to increase fluid intake in residential care homes include identifying and overcoming individual and institutional barriers to drinking, such as being worried about not reaching the toilet in time, physical inability to make or to reach drinks, and reduced social drinking and drinking pleasure. Research needs are discussed, some of which will be addressed by the FP7-funded NU-AGE (New dietary strategies addressing the specific needs of elderly population for a healthy ageing in Europe) trial. PMID:24333321

  7. Problem: Thirst, Drinking Behavior, and Involuntary Dehydration

    NASA Technical Reports Server (NTRS)

    Greenleaf, John E.

    1992-01-01

    The phenomenon of involuntary dehydration, the delay in full restoration of a body water deficit by drinking, has been described extensively but relatively little is known about its physiological mechanism. It occurs primarily in humans when they are exposed to various stresses including exercise, environmental heat and cold, altitude, water immersion, dehydration, and perhaps microgravity, singly and in various combinations. The level of involuntary dehydration is approximately proportional to the degree of total stress imposed on the body. Involuntary dehydration appears to be controlled by more than one factor including social customs that influence what is consumed, the capacity and rate of fluid absorption from the gastrointestinal system, the level of cellular hydration involving the osmotic-vasopressin interaction with sensitive cells or structures in the central nervous system, and, to a lesser extent, hypovolemic-angiotensin II stimuli. Since humans drink when there is no apparent physiological stimulus, the psychological component should always be considered when investigating the total mechanisms for drinking.

  8. DEHYDRATION OF LOW WATER CONTENT ETHANOL

    EPA Science Inventory

    Pervaporation has emerged as an economically viable alternative technology for the dehydration of organic solvents, removal of organic compounds from water and organic/organic separations. Development of a membrane system with suitable flux and selectivity characteristics plays a...

  9. Dehydration resistance of liposomes containing trehalose glycolipids

    NASA Astrophysics Data System (ADS)

    Nyberg, Kendra; Goulding, Morgan; Parthasarathy, Raghuveer

    2010-03-01

    The pathogen, Mycobacterium tuberculosis, has an unusual outer membrane containing trehalose glycolipids that may contribute to its ability to survive freezing and dehydration. Based on our recent discovery that trehalose glycolipids confer dehydration resistance to supported lipid monolayers (Biophys. J. 94: 4718-4724 (2008); Langmuir 25: 5193-5198, (2009)), we hypothesized that liposomes containing synthetic trehalose glycolipids may be dehydration-resistant as well. To test this, we measured the leakage of encapsulated fluorophores and larger macromolecular cargo from such liposomes subject to freeze drying. Both leakage assays and size measurements show that the liposomes are dehydration-resistant. In addition to demonstrating a possibly technologically useful encapsulation platform, our results corroborate the view that encapsulation in a trehalose-glycolipid-rich membrane is a biophysically viable route to protection of mycobacteria from environmental stresses.

  10. Crystal Dehydration in Membrane Protein Crystallography.

    PubMed

    Sanchez-Weatherby, Juan; Moraes, Isabel

    2016-01-01

    Crystal dehydration has been successfully implemented to facilitate the structural solution of a number of soluble and membrane protein structures over the years. This chapter will present the currently available tools to undertake controlled crystal dehydration, focusing on some successful membrane protein cases. Also discussed here will be some practical considerations regarding membrane protein crystals and the relationship between different techniques in order to help researchers to select the most suitable technique for their projects. PMID:27553236

  11. Dehydration processes using membranes with hydrophobic coating

    SciTech Connect

    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.

  12. Dehydration: why is it still a problem?

    PubMed

    Campbell, Naomi

    Reports from organisations such as the Care Quality Commission have identified many hospital patients, particularly older people, are suffering from dehydration. A range of national initiatives have emphasised the importance of hydration and nutrition, and offered guidance to help address shortcomings, yet the problems persist. This article examines the interplay of factors that affect the assessment and identification of dehydration, and its prevention. It also offers strategies to help nurses to ensure patients receive adequate hydration. PMID:21761784

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

    PubMed

    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. PMID:27053647

  14. 21 CFR 73.40 - Dehydrated beets (beet powder).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 1 2011-04-01 2011-04-01 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...

  15. 21 CFR 73.40 - Dehydrated beets (beet powder).

    Code of Federal Regulations, 2010 CFR

    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...

  16. Double Seismic Zones and Dehydration Embrittlement

    NASA Astrophysics Data System (ADS)

    Seno, T.; Yamasaki, T.

    2001-12-01

    Dehydration embrittlement is still an attractive mechanism for intermediate-depth earthquake occurrence. We explore the possibility whether this hypothesis can explain the observed geometry of the double seismic zones. We calculate transient temperature structures of slabs using a finite element method, based on geologically estimated subduction histories for NE Japan, SW Japan, E. Aleutian, N. Chile, Taiwan, and Cape Mendocino, where double zones have been observed. We then delineate the dehydration loci utilizing the phase diagrams of serpentine by Wunder and Schreyer (1997), Bose and Navrotsky (1998) and Ulmer and Trommsdorff (1995), and of meta-basalt by Kerrick and Connolly (2001). For slabs whose crust passes from blueschist to lawsonite-eclogite facies, we take the glaucophane-out boundary as the upper limit of the significant dehydration of meta-basalt. The dehydration loci of serpentine produces a double-layered structure for NE Japan, E. Aleutian, N. Chile, and Taiwan, whose slabs are older than 40 Ma at the trench. In these regions, the lower zone of the double zones can be explained by the lower dehydration locus of serpentine, and the upper zone by that of meta-basalt. The deepest portion of the upper zone might contain the upper dehydration locus of serpentine; however, this occurs only in NE Japan and E. Aleutian. The dehydration loci of serpentine degenerate into a single one in SW Japan and Cape Mendocino whose slabs are younger than 20 Ma at the trench. For these regions, the lower zone of the double zone is explained by the degenerated dehydration locus of serpentine and the upper zone by successive dehydration of meta-basalt from greenschist to dry eclogite facies in the shallow depth. Provided that the oceanic crust is metamorphosed into hydrated minerals at the mid-ocean ridge, the condition for the existence of a double zone is the serpentinization of the subducting oceanic plate at mid-plate depth for a cold slab and at shallow depth for a

  17. Dehydration kinetics of talc at 1 bar

    NASA Technical Reports Server (NTRS)

    Ganguly, J.; Bose, K.

    1991-01-01

    Experimental results on the dehydration kinetics of talc, which is likely to be a major potential resource for water and hydrogen in carbonaceous chondrites, is presented. The rate of dehydration of an essentially pure Mg-end member natural talc, (Mg(.99)Fe(.01))3Si4O10(OH)2, was studied by measuring in situ weight change under isothermal condition at 1 bar as a function of time in the temperature range 775 to 985 C. The grain size of the starting material was 0.7 to 1 micron. It was found that the data up to 50 to 60 percent dehydration can be fitted by an equation of the form alpha = exp(-Kt(exp n)), where alpha is the weight fraction of talc remaining, K is a rate constant and n is a numerical constant for a given temperature. For any set of isothermal data, there is a major change in the value of n for larger dehydration. For up to approximately 50 percent dehydration, all rate constants can be described by an Arrheniun relation with an activation energy of 432 (+/- 30) kJ/mol; n has a nearly constant value of 0.54 between 775 and 875 C, but increases almost linearly according to n = -10.77 + 0.012T C at T greater than or equal to 875 C.

  18. Dehydration-responsive features of Atrichum undulatum.

    PubMed

    Hu, Ruoyang; Xiao, Lihong; Bao, Fang; Li, Xuedong; He, Yikun

    2016-09-01

    Drought is an increasingly important limitation on plant productivity worldwide. Understanding the mechanisms of drought tolerance in plants can lead to new strategies for developing drought-tolerant crops. Many moss species are able to survive desiccation-a more severe state of dehydration than drought. Research into the mechanisms and evolution of desiccation tolerance in basal land plants is of particular significance to both biology and agriculture. In this study, we conducted morphological, cytological, and physiological analyses of gametophytes of the highly desiccation-tolerant bryophyte Atrichum undulatum (Hedw.) P. Beauv during dehydration and rehydration. Our results suggested that the mechanisms underlying the dehydration-recovery cycle in A. undulatum gametophytes include maintenance of membrane stability, cellular structure protection, prevention of reactive oxygen species (ROS) generation, elimination of ROS, protection against ROS-induced damage, and repair of ROS-induced damage. Our data also indicate that this dehydration-recovery cycle consists not only of the physical removal and addition of water, but also involves a highly organized series of cytological, physiological, and biochemical changes. These attributes are similar to those reported for other drought- and desiccation-tolerant plant species. Our findings provide major insights into the mechanisms of dehydration-tolerance in the moss A. undulatum. PMID:27255889

  19. Glucose loading and dehydration in the camel.

    PubMed

    Yagil, R; Berlyne, G M

    1977-05-01

    Five female bedouin camels were subjected to large infusions of glucose, both when water was readily available and following 10 days of water deprivation. When the camels were hydrated the extra glucose was readily given off in the urine with only a slight increase in blood levels. Following dehydration, the blood glucose levels increased greatly while the urinary excretion was limited. Dehydration led to decreased blood insulin levels, while glucose infusion led to increased levels. The data show that the acclimatization of the camel to dehydration is not only a question of long-term adaption to desert conditions but that even following acute nonphysiological stress, i.e., glucosuria, excess loss of body water was prevented. PMID:863833

  20. Geothermal demonstration: Zunil food dehydration facility

    SciTech Connect

    Maldonado, O. ); Altseimer, J.; Thayer, G.R. ); Cooper, L. ); Caicedo, A. . 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 in the Winter Arctic Tropopause Region

    NASA Technical Reports Server (NTRS)

    Pfister, Leonhard; Jensen, Eric; Podolske, James; Selkirk, Henry; Anderson, Bruce; Avery, Melody; Diskin. Glenn

    2004-01-01

    Recent work has shown that limited amounts of tropospheric air can penetrate as much as 1 km into the middleworld stratosphere during the arctic winter. This, coupled with temperatures that are cold enough to produce saturation mixing ratios of less than 5 ppmv at the tropopause, results in stratospheric cloud formation and upper tropospheric dehydration. Even though these "cold outbreaks" occupy only a small portion of the area in the arctic (1-2%), their importance is magnified by an order of magnitude because of the air flow through them. This is reinforced by evidence of progressive drying through the winter measured during SOLVE-1. The significance of this process lies in its effect on the upper tropospheric water content of the middle and high latitude tropopause region, which plays an important role in regulating the earth's radiative balance. There appears to be significant year-to-year variability in the incidence of the cold outbreaks. This work has two parts. First, we describe case studies of dehydration taken from the SOLVE and SOLVE2 aircraft sampling missions during the Arctic winters of 2000 and 2003 respectively. Trajectory based microphysical modeling is employed to examine the sensitivity of the dehydration to microphysical parameters and the nature of sub-grid scale temperature fluctuations. We then examine the year-to-year variations in potential dehydration using a trajectory climatology.

  2. What's the Big Sweat about Dehydration? (For Kids)

    MedlinePlus

    ... Dictionary of Medical Words En Español What Other Kids Are Reading Back-to-School Butterflies? Read This ... What's the Big Sweat About Dehydration? KidsHealth > For Kids > What's the Big Sweat About Dehydration? Print A ...

  3. Hydration-dehydration, heat, humidity, and "cool, clear, water".

    PubMed

    Lockett, Lawrence J

    2012-12-01

    Personal recollections of dehydration meltdowns during the Kona Ironman Triathlon, reflections on their cause, and the author's experiential recommendations regarding hydration, prevention of dehydration, and "beat the heat and humidity" measures. PMID:23147099

  4. 21 CFR 73.40 - Dehydrated beets (beet powder).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...) Identity. (1) The color additive dehydrated beets is a dark red powder prepared by dehydrating sound... specifications: Volatile matter, not more than 4 percent. Acid insoluble ash, not more than 0.5 percent. Lead...

  5. 21 CFR 73.40 - Dehydrated beets (beet powder).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...) Identity. (1) The color additive dehydrated beets is a dark red powder prepared by dehydrating sound... specifications: Volatile matter, not more than 4 percent. Acid insoluble ash, not more than 0.5 percent. Lead...

  6. Dehydration and rehydration of a tuff vitrophyre

    SciTech Connect

    Vaniman, D.; Bish, D., Chipera, S.

    1993-12-10

    The basal vitrophyre of the Topopah Spring Member of the Paintbrush Tuff at Yucca Mountain, Nevada, is a perlitic glass with 2.8 to 4.6% water. The dehydration of this vitrophyre was studied by thermogravimetric analysis (TGA) and by isothermal heating at 50{degrees}, 100{degrees}, 200{degrees}, and 400{degrees}C for 3.4 years followed by 1.1 years of rehydration at high controlled humidity ({approximately}79% relative humidity). No crystallization of the glass was observed in long-term dehydration or rehydration; the only observed chemical alteration was loss of up to 60% of original fluorine. TGA studies show a characteristic two-stage dehydration of the vitrophyre, with two-thirds to three-fourths weight loss occurring most rapidly at temperatures ranging from 278{degrees} to 346{degrees}C in 10{degrees}C/min heating experiments. The remaining water, about 1% in all of the vitrophyre samples studied regardless of total water content, is lost only on second-stage heating to temperatures above 650{degrees}C. Long-term isothermal heating at {le}400{degrees}C releases only the first-stage water. Loss of essentially all first-stage water occurred in less than 1 hour at 400{degrees}C; proportionately lower losses were obtained at 200{degrees} and 100{degrees}C. Small (0.2%) water loss occurred in the 50{degrees}C experiment. A time-temperature-dehydration diagram generated from the isothermal heating data shows a clustering of dehydration contours that are the equilibrium equivalent of the rapid first-stage water loss in dynamic TGA experiments. These dry-heating experiments provide an end-member characterization of glass transformations for comparison with water-saturated heating experiments in which glass alteration is prominent. 29 figs., 7 figs., 7 tabs.

  7. 21 CFR 73.40 - Dehydrated beets (beet powder).

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Dehydrated beets (beet powder). 73.40 Section 73.40 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.40 Dehydrated beets (beet powder). (a) Identity. (1) The color additive dehydrated beets...

  8. Dehydration, Hyperthermia, and Athletes: Science and Practice

    PubMed Central

    Murray, Robert

    1996-01-01

    Objective: To present the recent research that underscores the value of preventing both dehydration and hyperthermia. Such efforts will improve the athlete's capacity to perform physical activity and reduce the risk of heat-related problems. Data Sources: Data were drawn from an extensive review of the scientific literature over the past 50 years with an emphasis on recent research (> 1990) that focuses on the physiological and performance benefits of fluid replacement. Data Synthesis: Even low levels of dehydration (eg, less than a 2% loss of body weight) impair cardiovascular and thermoregulatory response and reduce the capacity for exercise. Heat exposure also reduces the athlete's ability to train and compete, an effect that can be independent of hydration status. Even if athletes are well hydrated, hot weather alone will reduce their capacity to exercise. Optimal performance is possible only when dehydration and hyperthermia are minimized by ingesting ample volumes of fluid during exercise and by taking common-sense precautions in keeping cool. Recent research has demonstrated that consuming fluid in volumes approximating sweat loss maintains important physiological functions and significantly improves exercise performance, even during exercise lasting only 1 hour. Carbohydrate ingestion also improves exercise performance, an effect that is independent of, and additive to, preventing dehydration. Conclusion/Application: Athletes should follow an aggressive fluid replacement and temperature regulation regimen. Successful implementation of this regimen requires that athletic trainers, coaches, athletes, and support personnel are made aware of the benefits of adequate fluid replacement, that appropriate fluid replacement strategies are developed and implemented, that athletes have the opportunity to train themselves to ingest larger volumes of fluid more frequently, and that other practical steps are taken to keep athletes cool during both training and

  9. Dehydration-induced drinking in humans

    NASA Technical Reports Server (NTRS)

    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.

  10. Fasting headache, weight loss, and dehydration.

    PubMed

    Mosek, A; Korczyn, A D

    1999-03-01

    Recently, we showed that fasting is a strong headache precipitator unrelated to coffee, tea, or smoking withdrawal or to oversleeping. In the current study, we evaluated the role of dehydration as a possible precipitator of fasting headache. The effects of a 25-hour fast of the Jewish Yom Kippur (Day of Atonement) were studied in women who participated in our previous Yom Kippur study. We asked the subjects to weigh themselves at the beginning and at the end of the Yom Kippur fast, assuming that the weight loss would largely reflect dehydration. In all but 1 of the 56 participants, the fast resulted in weight loss but only 28 (50%) reported headache. The average weight loss was 1.4 +/- 0.8 kg in those who developed headache and 1.2 +/- 0.5 kg in those who did not. This small difference was not statistically significant. We conclude that dehydration, as reflected by acute weight loss, is an unlikely cause of headache during a single day of fasting. The mechanism of fasting headache remains unclear. PMID:15613218

  11. Solar energy food dehydration system: Concept development

    SciTech Connect

    Pham, L.V.

    1988-01-01

    The research activities to be carried out to form the body of this work were planned, first, to increase the general knowledge in the areas of solar energy application and, secondly, to provide sufficient data for the development of a new solar energy powered food dehydrating system. The research work does not aim merely at pursuing the study and development of a new component or a new type of material to be used in the solar industry. But the final and main part of this research is devoted to the development and design of a solar energy system uncharted before the purpose of dehydrating various agricultural products. This proposed solar powered system development is thereby a contribution of technological knowledge to the field of Applied Sciences. It is one of the viable and effective solutions to solving the world's food and energy shortage problem, especially in the less developed regions of the world. The body of this work, thus is divided into three major parts as follows: (1) The search for a thorough understanding of the origin and fundamental characteristics of solar energy. (2) Past and present applications of solar energy. (3) The development and design of a new solar energy powered system for the dehydration of food crops.

  12. Biomass energy analysis for crop dehydration

    SciTech Connect

    Whittier, J.P.; Haase, S.G.; Quinn, M.W.; Zachritz, W.; Lansford, R.; Swanson, D.

    1995-06-01

    In 1994, an agricultural processing facility began constructing a new spice and herb dehydration facility in southern New Mexico. Because of the considerable energy intensity of the dehydration operation, management of energy costs is of special concern to the facility. Biomass energy conversion offers the potential for firms to reduce annual operating costs-especially firms with access to low-cost resources. Because the selected facility produces a biomass by-product as a result of its dehydration operation, it is appropriate to explore the technical, regulatory, institutional and economic conditions that affect the successful utilization of biomass resources. The facility is characterized as a small-scale installation, relative to other energy users. In this context, small-scale represents less than 100 million Btu per hour of thermal load and less than 1 MWe of electrical load. However, the projected annual energy bill is approximately $1.1 million and represents a significant portion of operational costs for the firm. For this study, the biomass resources in southern New Mexico and western Texas are detailed. Annual supplies of various biomass resources (i.e., wood chips, pecan shells, discarded tires and cotton gin trash) were inventoried. Further, delivered costs are projected for each of the resource forms. A technical assessment for the small-scale gasification and combustion systems is presented.

  13. May eclogite dehydration cause slab fracturation ?

    NASA Astrophysics Data System (ADS)

    Loury, Chloé; Lanari, Pierre; Rolland, Yann; Guillot, Stéphane; Ganino, Clément

    2015-04-01

    Petrological and geophysical evidences strongly indicate that fluids releases play a fundamental role in subduction zones as in subduction-related seismicity and arc magmatism. It is thus important to assess quantitatively their origin and to try to quantify the amount of such fluids. In HP metamorphism, it is well known that pressure-dependent dehydration reactions occur during the prograde path. Many geophysical models show that the variations in slab physical properties along depth could be linked to these fluid occurrences. However it remains tricky to test such models on natural sample, as it is difficult to assess or model the water content evolution in HP metamorphic rocks. This difficulty is bound to the fact that these rocks are generally heterogeneous, with zoned minerals and preservation of different paragenesis reflecting changing P-T conditions. To decipher the P-T-X(H2O) path of such heterogeneous rocks the concept of local effective bulk (LEB) composition is essential. Here we show how standardized X-ray maps can be used to constrain the scale of the equilibration volume of a garnet porphyroblast and to measure its composition. The composition of this equilibrium volume may be seen as the proportion of the rock likely to react at a given time to reach a thermodynamic equilibrium with the growing garnet. The studied sample is an eclogite coming from the carboniferous South-Tianshan suture (Central Asia) (Loury et al. in press). Compositional maps of a garnet and its surrounding matrix were obtained from standardized X-ray maps processed with the program XMapTools (Lanari et al, 2014). The initial equilibration volume was modeled using LEB compositions combined together with Gibbs free energy minimization. P-T sections were calculated for the next stages of garnet growth taking into account the fractionation of the composition at each stage of garnet growth. The modeled P-T-X(H2O) path indicates that the rock progressively dehydrates during the

  14. Dehydration of plutonium or neptunium trichloride hydrate

    DOEpatents

    Foropoulos, Jr., Jerry; Avens, Larry R.; Trujillo, Eddie A.

    1992-01-01

    A process of preparing anhydrous actinide metal trichlorides of plutonium or neptunium by reacting an aqueous solution of an actinide metal trichloride selected from the group consisting of plutonium trichloride or neptunium trichloride with a reducing agent capable of converting the actinide metal from an oxidation state of +4 to +3 in a resultant solution, evaporating essentially all the solvent from the resultant solution to yield an actinide trichloride hydrate material, dehydrating the actinide trichloride hydrate material by heating the material in admixture with excess thionyl chloride, and recovering anhydrous actinide trichloride is provided.

  15. Dehydration of plutonium or neptunium trichloride hydrate

    DOEpatents

    Foropoulos, J. Jr.; Avens, L.R.; Trujillo, E.A.

    1992-03-24

    A process is described for preparing anhydrous actinide metal trichlorides of plutonium or neptunium by reacting an aqueous solution of an actinide metal trichloride selected from the group consisting of plutonium trichloride or neptunium trichloride with a reducing agent capable of converting the actinide metal from an oxidation state of +4 to +3 in a resultant solution, evaporating essentially all the solvent from the resultant solution to yield an actinide trichloride hydrate material, dehydrating the actinide trichloride hydrate material by heating the material in admixture with excess thionyl chloride, and recovering anhydrous actinide trichloride.

  16. Intrastab Earthquakes: Dehydration of the Cascadia Slab

    USGS Publications Warehouse

    Preston, L.A.; Creager, K.C.; Crosson, R.S.; Brocher, T.M.; Trehu, A.M.

    2003-01-01

    We simultaneously invert travel times of refracted and wide-angle reflected waves for three-dimensional compressional-wave velocity structure, earthquake locations, and reflector geometry in northwest Washington state. The reflector, interpreted to be the crust-mantle boundary (Moho) of the subducting Juan de Fuca plate, separates intrastab earthquakes into two groups, permitting a new understanding of the origins of intrastab earthquakes in Cascadia. Earthquakes up-dip of the Moho's 45-kilometer depth contour occur below the reflector, in the subducted oceanic mantle, consistent with serpentinite dehydration; earthquakes located down-dip occur primarily within the subducted crust, consistent with the basalt-to-eclogite transformation.

  17. Intraslab earthquakes: dehydration of the Cascadia slab.

    PubMed

    Preston, Leiph A; Creager, Kenneth C; Crosson, Robert S; Brocher, Thomas M; Trehu, Anne M

    2003-11-14

    We simultaneously invert travel times of refracted and wide-angle reflected waves for three-dimensional compressional-wave velocity structure, earthquake locations, and reflector geometry in northwest Washington state. The reflector, interpreted to be the crust-mantle boundary (Moho) of the subducting Juan de Fuca plate, separates intraslab earthquakes into two groups, permitting a new understanding of the origins of intraslab earthquakes in Cascadia. Earthquakes up-dip of the Moho's 45-kilometer depth contour occur below the reflector, in the subducted oceanic mantle, consistent with serpentinite dehydration; earthquakes located down-dip occur primarily within the subducted crust, consistent with the basalt-to-eclogite transformation. PMID:14615535

  18. Reducing dehydration in residents of care homes.

    PubMed

    Hooper, Lee; Whitelock, Suzan; Bunn, Diane

    Dehydration can have serious consequences for older people and is a particular problem for residents of nursing and care homes. This article, the second in a two-part series, describes how a specialist care home for people with dementia in Great Yarmouth introduced high-quality hydration care to frail residents. By involving all staff and ensuring residents take a litre of fluid by the end of a relaxed and extended breakfast, staff have reduced anxiety and aggression and created a calmer and more sociable atmosphere. This has benefitted residents, visitors and staff, and is reflected in low levels of unplanned hospital admissions and paramedic call-outs. PMID:26492664

  19. Effects of Dehydration on Fish Muscles at Chilled Temperature

    NASA Astrophysics Data System (ADS)

    Miki, Hidemasa; Seto, Fuminori; Nishimoto, Motomi; Nishimoto, Junichi

    Recently,new method of removing water from fish fillet at low temperature using dehydration sheet have been reported. The present study is concerned with the factors to affect the quality during dehydration of horse mackerel muscle at low temperature. The rate of dehydration at -3 °C was about two times faster than that at 0 °C. The rate of denaturation of fish muscle protein was kept less than about 10 % (ATPase activity) of the undenaturated initial values after removing free water content. Present results suggest the practical possibility of the dehydration at -3 °C for keeping quality of fish flesh.

  20. Olfactory contributions to dehydration-induced anorexia in weanling rats.

    PubMed

    Bruno, J P; Hall, W G

    1982-11-01

    By 20 days of age, dehydration produces a clear anorexia, even though weanling rats have had only limited feeding and drinking experience. Their lack of ingestive experience makes weanlings good subjects for studying the physiological mechanisms subserving anorexic phenomena because learned contributions are unlikely to add significant complications. Twenty-day-old rats dehydrated by hypertonic saline injection were anorexic when offered milk or solid food (rat chow), but not when offered sucrose solutions (Experiment I). However, when the scent of almond was associated with sucrose solutions, or with water, intake of these solutions was depressed by dehydration (Experiment II). Thus for dehydrated rats, olfactory stimulation may help produce dehydration-induced anorexia. Making rats anosmic by intransal lavage with ZnSO4 (Experiment III) eliminated the anorexia to almond-scented water and partially eliminated that to milk. For these fluids, an odor cue seems a requirement for the occurrence of dehydration-anorexia. In Experiment IV, we found that dehydration-anorexia did not occur when milk was infused directly into pups' mouths. This finding suggests that the inhibitory process mediating dehydration-anorexia influences the approach to food and not the actual consumatory response that occurs once food is in the mouth. The inhibition of feeding produced by dehydration, therefore, may depend largely on olfactory cues, and seems to operate at a distance, as rats locate and approach food. PMID:7152117

  1. Dehydration-mediated cluster formation of nanoparticles

    NASA Astrophysics Data System (ADS)

    Ahn, Sungsook; Joon Lee, Sang

    2015-06-01

    Drying procedure is a powerful method to modulate the bottom-up assembly of basic building component. The initially weak attraction between the components screened in a solution strengthens as the solvent evaporates, organizing the components into structures. Drying is process-dependent, irreversible, and nonequilibrated, thus the mechanism and the dynamics are influenced by many factors. Therefore, the interaction of the solvent and the elements during the drying procedure as well as the resulting pattern formations are strongly related. Nonetheless still many things are open in questions in terms of their dynamics. In this study, nanoscale dehydration procedure is experimentally investigated using a nanoparticle (NP) model system. The role of water is verified in a single NP scale and the patterns of collective NP clusters are determined. Stepwise drying procedures are proposed based on the location from which water is removed. Effective water exodus from a unit NP surface enhances the attractive interaction in nanoscale and induces heterogeneous distribution in microscale. This study provides fundamental proof of systematic relation between the dehydration process and the resultant cluster patterns in hierarchical multiscales.

  2. Dehydration-mediated cluster formation of nanoparticles.

    PubMed

    Ahn, Sungsook; Lee, Sang Joon

    2015-01-01

    Drying procedure is a powerful method to modulate the bottom-up assembly of basic building component. The initially weak attraction between the components screened in a solution strengthens as the solvent evaporates, organizing the components into structures. Drying is process-dependent, irreversible, and nonequilibrated, thus the mechanism and the dynamics are influenced by many factors. Therefore, the interaction of the solvent and the elements during the drying procedure as well as the resulting pattern formations are strongly related. Nonetheless still many things are open in questions in terms of their dynamics. In this study, nanoscale dehydration procedure is experimentally investigated using a nanoparticle (NP) model system. The role of water is verified in a single NP scale and the patterns of collective NP clusters are determined. Stepwise drying procedures are proposed based on the location from which water is removed. Effective water exodus from a unit NP surface enhances the attractive interaction in nanoscale and induces heterogeneous distribution in microscale. This study provides fundamental proof of systematic relation between the dehydration process and the resultant cluster patterns in hierarchical multiscales. PMID:26077841

  3. Biomass energy analysis for crop dehydration

    SciTech Connect

    Whittier, J.P.; Haase, S.G.; Quinn, M.W.

    1994-12-31

    In 1994, an agricultural processing facility was constructed in southern New Mexico for spice and herb dehydration. Annual operational costs are dominated by energy costs, due primarily to the energy intensity of dehydration. A feasibility study was performed to determine whether the use of biomass resources as a feedstock for a cogeneration system would be an economical option. The project location allowed access to unusual biomass feedstocks including cotton gin trash, pecan shells and in-house residues. A resource assessment of the immediate project area determined that approximately 120,000 bone dry tons of biomass feedstocks are available annually. Technology characterization for the plant energy requirements indicated gasification systems offer fuel flexibility advantages over combustion systems although vendor support and commercial experience are limited. Regulatory siting considerations introduce a level of uncertainty because of a lack of a precedent in New Mexico for gasification technology and because vendors of commercial gasifiers have little experience operating such a facility nor gathering emission data. A public opinion survey indicated considerable support for renewable energy use and biomass energy utilization. However, the public opinion survey also revealed limited knowledge of biomass technologies and concerns regarding siting of a biomass facility within the geographic area. The economic analysis conducted for the study is based on equipment vendor quotations, and indicates there will be difficulty competing with current prices of natural gas.

  4. Dehydration-mediated cluster formation of nanoparticles

    PubMed Central

    Ahn, Sungsook; Joon Lee, Sang

    2015-01-01

    Drying procedure is a powerful method to modulate the bottom-up assembly of basic building component. The initially weak attraction between the components screened in a solution strengthens as the solvent evaporates, organizing the components into structures. Drying is process-dependent, irreversible, and nonequilibrated, thus the mechanism and the dynamics are influenced by many factors. Therefore, the interaction of the solvent and the elements during the drying procedure as well as the resulting pattern formations are strongly related. Nonetheless still many things are open in questions in terms of their dynamics. In this study, nanoscale dehydration procedure is experimentally investigated using a nanoparticle (NP) model system. The role of water is verified in a single NP scale and the patterns of collective NP clusters are determined. Stepwise drying procedures are proposed based on the location from which water is removed. Effective water exodus from a unit NP surface enhances the attractive interaction in nanoscale and induces heterogeneous distribution in microscale. This study provides fundamental proof of systematic relation between the dehydration process and the resultant cluster patterns in hierarchical multiscales. PMID:26077841

  5. Intermediate magnetite formation during dehydration of goethite

    NASA Astrophysics Data System (ADS)

    Özdemir, Özden; Dunlop, David J.

    2000-04-01

    The dehydration of goethite has been studied by low-temperature induced magnetization (LTIM) and X-ray diffraction on well-characterized acicular crystals. Fresh samples were heated in air to temperatures between 155°C and 610°C. Goethite and hematite were the magnetically dominant phases after all runs except 500°C and 610°C, for which only hematite was found. However, partially dehydrated goethites after the 238-402°C runs had broad peaks or inflections in the LTIM curves around 120 K, suggesting the formation of an intermediate spinel phase. These samples were next given a saturation remanence in a field of 2 T at 10 K and the remanence was measured continuously during zero-field warming to 300 K. There was a decrease in remanence at the Verwey transition (120 K), diagnostic of magnetite. The possible formation of a small amount of magnetite is of serious concern in studies of goethite-bearing sediments and rocks. Chemical remanent magnetization (CRM) of this strongly magnetic spinel phase could significantly modify the direction as well as the intensity of the original goethite CRM. As well, it would be a new source of paleomagnetic noise as far as primary remanence carried by other mineral phases is concerned.

  6. Dehydration Parameters and Standards for Laboratory Mice

    PubMed Central

    Bekkevold, Christine M; Robertson, Kimberly L; Reinhard, Mary K; Battles, August H; Rowland, Neil E

    2013-01-01

    Water deprivation and restriction are common features of many physiologic and behavioral studies; however, there are no data-driven humane standards regarding mice on water deprivation or restriction studies to guide IACUC, investigators, and veterinarians. Here we acutely deprived outbred CD1 mice of water for as long as 48 h or restricted them to a 75% or 50% water ration; physical and physiologic indicators of dehydration were measured. With acute water deprivation, the appearance and attitude of mice deteriorated after 24 h, and weight loss exceeded 15%. Plasma osmolality was increased, and plasma volume decreased with each time interval. Plasma corticosterone concentration increased with duration of deprivation. There were no differences in any dehydration measures between mice housed in conventional static cages or ventilated racks. Chronic water restriction induced no significant changes compared with ad libitum availability. We conclude that acute water deprivation of as long as 24 h produces robust physiologic changes; however, deprivation in excess of 24 h is not recommended in light of apparent animal distress. Although clearly thirsty, mice adapt to chronic water restriction of as much as 50% of the ad libitum daily ration that is imposed over an interval of as long as 8 d. PMID:23849404

  7. Dehydration-driven topotaxy in subduction zones

    NASA Astrophysics Data System (ADS)

    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

  8. Double seismic zone and dehydration embrittlement of the subducting slab

    NASA Astrophysics Data System (ADS)

    Yamasaki, Tadashi; Seno, Tetsuzo

    2003-04-01

    Dehydration embrittlement of metamorphosed oceanic crust and mantle in the subducting slab may be responsible for the occurrence of intermediate-depth earthquakes. We explore the possibility that this hypothesis can explain the morphology of the double seismic zones observed in northeast Japan, southwest Japan, northeast Taiwan, northern Chile, Cape Mendocino, and eastern Aleutians. We calculate transient temperature structures of slabs based on geologically estimated subduction histories of these regions. We then determine dehydration loci of metamorphosed oceanic crust and serpentinized mantle using experimentally derived phase diagrams. The depth range of the dehydration loci of metamorphosed oceanic crust and serpentine is dependent on slab age. The dehydration loci of serpentine produce a double-layered structure. Because the upper dehydration loci of serpentine are mostly located in the wedge mantle above the slab, we regard the upper plane seismicity representing dehydration embrittlement in the oceanic crust, and we fix the slab geometry so that the upper plane seismicity is just below the upper surface of the slab. We find that the lower plane seismicity is located at the lower dehydration loci of serpentine, which indicates that the morphology of the double seismic zones is consistent with the dehydration embrittlement.

  9. Dehydration accelerates root respiration and impacts sugarbeet raffinose metabolism

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sugarbeet roots lose water during storage and often become severely dehydrated after prolonged storage and at the outer portions of piles which have greater wind and sun exposure. Sucrose loss is known to be elevated in dehydrated roots, although the metabolic processes responsible for this loss ar...

  10. Smackerels of Somethings: Dehydrating Food and How to Use It.

    ERIC Educational Resources Information Center

    Ditzler, Carmen

    1994-01-01

    Provides ideas about how to add variety, flavor, texture, and nutrition to outdoor meals by dehydrating food and using it on camping trips. The goal is to prepare nutritious and appealing meals without spending a lot of money on commercially dehydrated or freeze-dried foods. Includes instructions for rehydrating foods. (LP)

  11. Retention of nutrients in green leafy vegetables on dehydration.

    PubMed

    Gupta, Sheetal; Gowri, B S; Lakshmi, A Jyothi; Prakash, Jamuna

    2013-10-01

    The objective of the study was to investigate the influence of dehydration on nutrient composition of Amaranthus gangeticus, Chenopodium album, Centella asiatica, Amaranthus tricolor and Trigonella foenum graecum. The green leafy vegetables (GLV) were steam blanched for 5 min after pretreatment and dried in an oven at 60 °C for 10-12 h. The fresh and dehydrated samples were analyzed for selected proximate constituents, vitamins, minerals, antinutrients and dialyzable minerals. Dehydration seems to have little effect on the proximate, mineral and antinutrient content of the GLV. Among the vitamins, retention of ascorbic acid was 1-14%, thiamine 22-71%, total carotene 49-73% and β-carotene 20-69% respectively, of their initial content. Dialyzable iron and calcium in the fresh vegetables ranged between 0.21-3.5 mg and 15.36-81.33 mg/100 g respectively, which reduced to 0.05-0.53 mg and 6.94-58.15 mg/100 g on dehydration. Dehydration seems to be the simplest convenient technology for preserving these sources of micronutrients, especially when they are abundantly available. Irrespective of the losses of vitamins that take place during dehydration, dehydrated GLV are a concentrated natural source of micronutrients and they can be used in product formulations. Value addition of traditional products with dehydrated GLV can be advocated as a feasible food-based approach to combat micronutrient malnutrition. PMID:24425998

  12. Two-stage dehydration of sugars

    DOEpatents

    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.

  13. Avoiding failed reconstitution of ultradeformable liposomes upon dehydration.

    PubMed

    Montanari, J; Roncaglia, D I; Lado, L A; Morilla, M J; Romero, E L

    2009-05-01

    Although freeze-drying is an ordinarily used technique to dehydrate conventional liposomes, we have found that ultradeformable liposomes (UDLs) suffered irreversible aggregation when rehydrated upon freeze-drying (99.4% water elimination), even in high sugar content (4/1 sucrose/lipid mass ratio). When dehydrated by speed vac and vacuum drying, two alternative techniques that rendered less pronounced dehydration (94.27 and 96.2% water elimination, respectively) and avoid ice formation, however, UDL could only be successfully rehydrated when vacuum dried in 4/1 sucrose/lipid mass ratios. Conventional liposomes, on the other hand, were successfully reconstituted upon dehydrated by the three methods in lower sugar content (2/1 sucrose/lipid mass ratio). These results indicated that the 27% mole sodium cholate within the UDL lipid matrix was responsible for a greater and differential mechanical sensitivity of the bilayers to the different dehydration stress, as compared to conventional liposomes. PMID:19429279

  14. DMSO induces dehydration near lipid membrane surfaces.

    PubMed

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

    2015-07-21

    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 <0.1, regardless of the lipid composition and the lipid phase. Specifically, DMSO was found to effectively destabilize the hydration water structure at the lipid membrane surface at XDMSO <0.1, lower the energetic barrier to dehydrate this surface water, whose displacement otherwise requires a higher activation energy, consequently yielding compressed interbilayer distances in multilamellar vesicles at equilibrium with unaltered bilayer thicknesses. 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

  15. Hyponatremic dehydration: an analysis of 78 cases.

    PubMed

    Caksen, H; Odabaş, D; Sar, S; Celebi, V; Arslan, S; Kuru, M; Abuhandan, M

    2001-01-01

    Our purpose was to determine the frequency of convulsion in children with hyponatremic dehydration (HD). We also investigated whether or not there was a relationship between the severity of hyponatremia and the degrees of malnutrition in our region (Eastern Anatolia of Turkey) in where malnutrition is frequently observed. In this study, the clinical and laboratory findings of 78 patients with diarrhoea (acute, persistent or chronic diarrhoea) and HD were studied. When diarrhoea lasts longer than 2 and 4 weeks they were accepted as persistent and chronic diarrhoea, respectively. Patients were said to have HD if they had the clinical findings of dehydration associated with hyponatremia [Serum sodium (SNa) <130 mmol/L)]. Nutritional status of the children was assessed by the Gomez classification using weight for age; it was accepted as normal those were between 90%-110%, mild malnutrition 75%-89%, moderate malnutrition 60%-74% and severe malnutrition <60%. Of 78 patients, 40 were boys, 38 were girls. The age and weight of the patients ranged from 40 days to 36 months (8.94 +/- 5.49 months) and from 2000 to 10,300 g (5535.25 +/- 1702.10 g) respectively. All patients except four had malnutrition; 15 (20.3%) had mild malnutrition, 30 (40.5%) had moderate malnutrition and 29 (39.2%) had severe malnutrition. Forty-seven patients had acute, 16 patients had persistent, and 15 patients had chronic diarrhoea. SNa levels were between 104 and 129 mmol/L (121.21 +/- 6.12 mmol/L). There was not statistically a significant difference between SNa level and the degree of malnutrition, and SNa level and the types (acute, persistent or chronic) of diarrhoea (p > 0.05). Of 78 patients, 12 (15.3%) patients had convulsion, of whom eight had convulsion associated with fever. Convulsion was noted in nine (19.1%) and three (18.7%) patients with acute and persistent diarrhoea, respectively (p > 0.05). Also, we observed that when hyponatremia was severer, convulsions tended to be more occuring

  16. Transient dehydration of lungs in tail-suspended rats

    NASA Technical Reports Server (NTRS)

    Hargens, A. R.; Steskal, J.; Morey-Holton, E. R.

    1985-01-01

    The fluid balance in the lungs of rats exposed to head-down tilt is examined. Six Munich-Wister rats were suspended for 7 days and 10 Sprague-Dawley rats for 14 days using the technique of Morey (1979). The water contents of the lungs of the suspended and a control group are calculated and compared. The data reveal that the two-days suspended rats had dehydrated lungs; however, the lungs of the 14-day suspended and control group rats were similar. It is noted that the dehydration in the 2-day suspended rats is caused by general dehydration not the head-tilt position.

  17. Formation of sulphate ion during the dehydration of sulphited vegetables.

    PubMed

    Wedzicha, B L; Herrera-Viloria, J C

    1991-01-01

    A reverse isotope dilution procedure was used to measure the formation of sulphate ion during the air dehydration of sulphited cabbage, carrot and potato at 80 degrees C. The conversion of sulphite to sulphate was found to be of first order with respect to sulphite. The formation of sulphate in the vegetables during dehydration accounts for only part of the sulphate in the dehydrated products; the remainder comes from the scald liquor. The technique for sulphate determination is critically evaluated and the observed yields discussed. PMID:1812014

  18. Renal tubular vasopressin receptors downregulated by dehydration

    SciTech Connect

    Steiner, M.; Phillips, M.I. )

    1988-03-01

    Receptors for arginine vasopressin (AVP) were characterized in tubular epithelial basolateral membranes (BL membranes) prepared from the kidneys of male Spraque-Dawley rats. Association of ({sup 3}H)AVP was rapid, reversible, and specific. Saturation studies revealed a single class of saturable binding sites with a maximal binding (B{sub max}) of 184 {plus minus} 15 fmol/mg protein. The V{sub 2} receptor antagonist was more than 3,700 times as effective in displacing ({sup 3}H)AVP than was the V{sub 1} antagonist. To investigate the physiological regulation of vasopressin receptors, the effects of elevated levels of circulating AVP on receptor characteristics were studied. Seventy-two-hour water deprivation significantly elevated plasma osmolality and caused an 11.5-fold increase in plasma (AVP). Scatchard analysis revealed a 38% decreased in the number of AVP receptors on the BL membranes from dehydrated animals. The high-affinity binding sites on the BL membranes fit the pharmacological profile for adenylate cyclase-linked vasopressin receptors (V{sub 2}), which mediate the antidiuretic action of the hormone. The authors conclude that physiologically elevated levels of AVP can downregulate vasopressin receptors in the kidney.

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

    NASA Technical Reports Server (NTRS)

    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.

  20. 25. BUILDING NO. 527, DEHYDRATING HOUSE, DETAIL OF SOLVENT RECOVERY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    25. BUILDING NO. 527, DEHYDRATING HOUSE, DETAIL OF SOLVENT RECOVERY DUCTS. SOUTH SIDE OF BUILDING. - Picatinny Arsenal, 500 Area, Powder Factory & Power House, State Route 15 near I-80, Dover, Morris County, NJ

  1. Survey of quality indicators in commercial dehydrated fruits.

    PubMed

    Megías-Pérez, Roberto; Gamboa-Santos, Juliana; Soria, Ana Cristina; Villamiel, Mar; Montilla, Antonia

    2014-05-01

    Physical and chemical quality parameters (dry matter, aw, protein, carbohydrates, vitamin C, 2-furoylmethyl amino acids, rehydration ratio and leaching loss) have been determined in 30 commercial dehydrated fruits (strawberry, blueberry, raspberry, cranberry, cherry, apple, grapefruit, mango, kiwifruit, pineapple, melon, coconut, banana and papaya). For comparison purposes, strawberry samples processed in the laboratory by freeze-drying and by convective drying were used as control samples. Overall quality of dehydrated fruits seemed to be greatly dependent on processing conditions and, in a cluster analysis, samples which were presumably subjected to osmotic dehydration were separated from the rest of fruits. These samples presented the lowest concentration of vitamin C and the highest evolution of Maillard reaction, as evidenced by its high concentration of 2-furoylmethyl amino acids. This is the first study on the usefulness of this combination of chemical and physical indicators to assess the overall quality of commercial dehydrated fruits. PMID:24360417

  2. NOVEL POLYMERIC MEMBRANE FOR DEHYDRATION OF ORGANIC SOLVENTS

    EPA Science Inventory

    Pervaporation has emerged as an economically viable alternative technology for dehydration of organic solvents, removal of organic compounds and organic/organic separations. Development of a membrane system with suitable flux and selectivity characteristics plays a critical role...

  3. External Validation and Comparison of Three Pediatric Clinical Dehydration Scales

    PubMed Central

    Jauregui, Joshua; Nelson, Daniel; Choo, Esther; Stearns, Branden; Levine, Adam C.; Liebmann, Otto; Shah, Sachita P.

    2014-01-01

    Objective To prospectively validate three popular clinical dehydration scales and overall physician gestalt in children with vomiting or diarrhea relative to the criterion standard of percent weight change with rehydration. Methods We prospectively enrolled a non-consecutive cohort of children ≤ 18 years of age with an acute episode of diarrhea or vomiting. Patient weight, clinical scale variables and physician clinical impression, or gestalt, were recorded before and after fluid resuscitation in the emergency department and upon hospital discharge. The percent weight change from presentation to discharge was used to calculate the degree of dehydration, with a weight change of ≥ 5% considered significant dehydration. Receiver operating characteristics (ROC) curves were constructed for each of the three clinical scales and physician gestalt. Sensitivity and specificity were calculated based on the best cut-points of the ROC curve. Results We approached 209 patients, and of those, 148 were enrolled and 113 patients had complete data for analysis. Of these, 10.6% had significant dehydration based on our criterion standard. The Clinical Dehydration Scale (CDS) and Gorelick scales both had an area under the ROC curve (AUC) statistically different from the reference line with AUCs of 0.72 (95% CI 0.60, 0.84) and 0.71 (95% CI 0.57, 0.85) respectively. The World Health Organization (WHO) scale and physician gestalt had AUCs of 0.61 (95% CI 0.45, 0.77) and 0.61 (0.44, 0.78) respectively, which were not statistically significant. Conclusion The Gorelick scale and Clinical Dehydration Scale were fair predictors of dehydration in children with diarrhea or vomiting. The World Health Organization scale and physician gestalt were not helpful predictors of dehydration in our cohort. PMID:24788134

  4. Osmotic factors in restitution from thermal dehydration in rats.

    PubMed

    Nose, H; Yawata, T; Morimoto, T

    1985-08-01

    The degree of voluntary dehydration after thermal dehydration was assessed while supplying drinking water of varying NaCl concentrations. Adult male albino rats were exposed to a hot-dry environment (dry bulb temp 36 degrees C; relative humidity 20%) for 6-8 h, and dehydration of 7% body wt was induced. After dehydration the rats were divided into three groups, and distilled water and 0.45 or 0.9% NaCl solution was given ad libitum. The amount of fluid intake reached an equilibrium in 6-12 h; the 0.45 and 0.9% NaCl groups regained almost all lost water, whereas the distilled water group regained only half. During rehydration the 0.45 and 0.9% NaCl groups gained Na by approximately 430-650 mueq and lost K by 90-130 mueq, whereas the distilled water group lost Na slightly and K by 80 mueq/100 g body wt. As for the electrolyte balance during thermal dehydration, rats excreted Na and K into urine and saliva. Na loss was 200 mueq/100 g, almost all of which was derived from the interstitial space of skin and skeletal muscle, and K loss was 230 mueq/100 g, almost all of which was derived from intracellular space of skeletal muscle. Total cation loss (Na, K) during thermal dehydration, including K excretion during rehydration, was 510-560 mueq/100 g, which was almost identical to the Na gained by rats given 0.45 or 0.9% NaCl solution. These results suggest that voluntary dehydration is caused by the dilutional inhibition of drinking due to loss of electrolytes during thermal dehydration. PMID:4025574

  5. Dehydration of cyclohexanol as a test reaction for zeolite acidity

    SciTech Connect

    Karge, H.G.; Kosters, H.; Wada, Y.

    1984-01-01

    Dehydration of cyclohexanol was investigated using a fixed-bed continuous flow reactor with acidic mordenite-type, clinoptilolite-type, and faujasite-type (Y) zeolites as catalysts. The surface acidity of the catalysts employed was studied by IR using pyridine or 2,6-di-tert. butylpyridine as probe molecules. A correlation between the acidity and the rates of dehydration was clearly shown.

  6. Fructokinase activity mediates dehydration-induced renal injury.

    PubMed

    Roncal Jimenez, Carlos A; Ishimoto, Takuji; Lanaspa, Miguel A; Rivard, Christopher J; Nakagawa, Takahiko; Ejaz, A Ahsan; Cicerchi, Christina; Inaba, Shinichiro; Le, MyPhuong; Miyazaki, Makoto; Glaser, Jason; Correa-Rotter, Ricardo; González, Marvin A; Aragón, Aurora; Wesseling, Catharina; Sánchez-Lozada, Laura G; Johnson, Richard J

    2014-08-01

    The epidemic of chronic kidney disease in Nicaragua (Mesoamerican nephropathy) has been linked with recurrent dehydration. Here we tested whether recurrent dehydration may cause renal injury by activation of the polyol pathway, resulting in the generation of endogenous fructose in the kidney that might subsequently induce renal injury via metabolism by fructokinase. Wild-type and fructokinase-deficient mice were subjected to recurrent heat-induced dehydration. One group of each genotype was provided water throughout the day and the other group was hydrated at night, after the dehydration. Both groups received the same total hydration in 24 h. Wild-type mice that received delayed hydration developed renal injury, with elevated serum creatinine, increased urinary NGAL, proximal tubular injury, and renal inflammation and fibrosis. This was associated with activation of the polyol pathway, with increased renal cortical sorbitol and fructose levels. Fructokinase-knockout mice with delayed hydration were protected from renal injury. Thus, recurrent dehydration can induce renal injury via a fructokinase-dependent mechanism, likely from the generation of endogenous fructose via the polyol pathway. Access to sufficient water during the dehydration period can protect mice from developing renal injury. These studies provide a potential mechanism for Mesoamerican nephropathy. PMID:24336030

  7. Kinetics of volatile extraction from carbonaceous chondrites: Dehydration of talc

    NASA Technical Reports Server (NTRS)

    Bose, Kunal; Ganguly, Jibamitra

    1991-01-01

    Carbonaceous chondrites are believed to be the primary constituents of near-Earth asteroids and Phobos and Deimos, and are potential resources of fuels that may be exploited for future planetary missions. Calculations of equilibrium phase relations suggest that talc (Ta) and antigorite (Ant) are likely to be the major hydrous phases in the C1 and C2 meteorites (Ganguly and Saxena, 1989), which constitute the most volatile rich classes of carbonaceous chondrites. The dehydration kinetics of talc are studied as a function of temperature, grain size, composition and fluid fugacity, as part of a systematic study of the reaction kinetics of the volatile bearing phases that are either known or likely to be present in carbonaceous chondrites. The dehydration kinetics were investigated at 1 bar, 775 to 875 C by monitoring the in-situ weight loss as a function of time of a natural talc. The talc platelets had a dimension of 0.8 to 1 micron. The run durations varied from 233.3 hours at 775 C (48 percent dehydration) to 20.8 hours at 875 C (80 pct. dehydration). The results can be adequately represented by a given rate equation. Theoretical analysis suggests that the reduction in the concentration of H2O in the environment of dehydrating talc, as would be encountered in processing chondritic materials, will have negligible effect on the rate of dehydration, unless there is a change of reaction mechanism owing to the presence of other volatile species.

  8. Whole transcriptome organisation in the dehydrated supraoptic nucleus.

    PubMed

    Hindmarch, C C T; Franses, P; Goodwin, B; Murphy, D

    2013-12-01

    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. PMID:24345907

  9. Seawater drinking restores water balance in dehydrated harp seals.

    PubMed

    How, Ole-Jakob; Nordøy, Erling S

    2007-07-01

    The purpose of this study was to answer the question of whether dehydrated harp seals (Phoca groenlandica) are able to obtain a net gain of water from the intake of seawater. Following 24 h of fasting, three subadult female harp seals were dehydrated by intravenous administration of the osmotic diuretic, mannitol. After another 24 h of fasting, the seals were given 1,000 ml seawater via a stomach tube. Urine and blood were collected for measurement of osmolality and osmolytes, while total body water (TBW) was determined by injections of tritiated water. In all seals, the maximum urinary concentrations of Na(+) and Cl(-) were higher than in seawater, reaching 540 and 620 mM, respectively, compared to 444 and 535 mM in seawater. In another experiment, the seals were given ad lib access to seawater for 48 h after mannitol-induced hyper-osmotic dehydration. In animals without access to seawater, the mean blood osmolality increased from 331 to 363 mOsm kg(-1) during dehydration. In contrast, the blood osmolality, hematocrit and TBW returned to normal when the seals were permitted ad lib access to seawater after dehydration. In conclusion, this study shows that harp seals have the capacity to gain net water from mariposa (voluntarily drinking seawater) and are able to restore water balance after profound dehydration by drinking seawater. PMID:17375309

  10. Lehmann discontinuity due to dehydration of phengite

    NASA Astrophysics Data System (ADS)

    Ono, S.

    2007-12-01

    convective flow in the upper mantle and intersects the dehydration boundary of phengite, the released water migrates into the surrounding mantle rock and the sharp boundary between the anisotropic and the isotropic structure is formed at around 220 km depth, because water enhances the change in the deformation mechanism of olivine. The Lehmann discontinuity is likely to be related with this boundary corresponding to the change in the deformation mechanism. As this exists only in regions of stagnated sediment, the local detection of the discontinuity is consistent with the hypothesis of sediment dehydration. The most characteristic features of the Lehmann discontinuity, such as 220 km depth, negative seismological Clapeyron slope, local detection, seismic velocity jump, and the seismological anisotropic to isotropic transition can be reasonably explained by our new model [2]. [1] Ono (1998) J. Geophys. Res., 103, 18253-18267. [2] Ono (2007) The Open Mineralogy Journal, 1, 1-4.

  11. Ice Cloud Formation and Dehydration in the Tropical Tropopause Layer

    NASA Technical Reports Server (NTRS)

    Jensen, Eric; Gore, Warren J. (Technical Monitor)

    2002-01-01

    Stratospheric water vapor is important not only for its greenhouse forcing, but also because it plays a significant role in stratospheric chemistry. Several recent studies have focused on the potential for dehydration due to ice cloud formation in air rising slowly through the tropical tropopause layer (TTL). Holton and Gettelman showed that temperature variations associated with horizontal transport of air in the TTL can drive ice cloud formation and dehydration, and Gettelman et al. recently examined the cloud formation and dehydration along kinematic trajectories using simple assumptions about the cloud properties. In this study, a Lagrangian, one-dimensional cloud model has been used to further investigate cloud formation and dehydration as air is transported horizontally and vertically through the TTL. Time-height curtains of temperature are extracted from meteorological analyses. The model tracks the growth, advection, and sedimentation of individual cloud particles. The regional distribution of clouds simulated in the model is comparable to the subvisible cirrus distribution indicated by SAGE II. The simulated cloud properties and cloud frequencies depend strongly on the assumed supersaturation threshold for ice nucleation. The clouds typically do not dehydrate the air along trajectories down to the temperature minimum saturation mixing ratio. Rather the water vapor mixing ratio crossing the tropopause along trajectories is 10-50% larger than the saturation mixing ratio. I will also discuss the impacts of Kelvin waves and gravity waves on cloud properties and dehydration efficiency. These simulations can be used to determine whether observed lower stratospheric water vapor mixing ratios can be explained by dehydration associated with in situ TTL cloud formation alone.

  12. Implications of dehydration reactions on the earthquake mechanics and faulting

    NASA Astrophysics Data System (ADS)

    Wheeler, J.; LECLÈRE, H.; Faulkner, D. R.; Mariani, E.

    2013-12-01

    Dehydration reactions are inferred to occur along subduction zones where rocks from the oceanic crust undergo a series of metamorphic reactions during their burial. Metamorphic dehydration reactions of hydrous minerals such as clays and serpentines have been suggested as a possible origin for intermediate depth earthquakes in subducting slabs. Indeed, fluid releasing and mechanical compaction of pores during dehydration reactions may induce fault instabilities. However, our understanding of the feedbacks between dehydration reaction, fluid flow properties and mechanical behavior is not yet integrated into a single unified model. In this study, we try to unravel the behavior of dehydration reactions from laboratory experiments conducted on gypsum with a triaxial deformation rigs under controlled temperature (30-140°C) and confining pressure (0-300 MPa). The aim of our set of experiments is to understand the coupling and feedbacks between the state of stress, the mechanical and hydraulic properties of gypsum and the metamorphic reactions. We monitor fluid expulsion, fluid pressure and strain evolution for a given confining pressure, differential stress and temperature during all experiments. In parallel, SEM observations and EBSD analyses are used to constrain reaction and deformation mechanisms occurring at grain scale during each experiment. These analyses conducted at grain scale allow us to discriminate the mechanism of deformation occurring in parallel of dehydration reaction and give information about the rheological laws and behavior of the material for the tested conditions. Llana Funez et al. (2012) focused on the link between fluid pressure and reaction rate. The samples, being porous, compacted, and in new work we examine that process in more detail. The results of laboratory experiments and microstructural analyses are then used to estimate the implications of dehydration reaction on earthquake mechanics and faulting in seismogenic geological contexts

  13. Dehydration and Cognition in Geriatrics: A Hydromolecular Hypothesis

    PubMed Central

    Sfera, Adonis; Cummings, Michael; Osorio, Carolina

    2016-01-01

    Dehydration is one of the ten most frequent diagnoses responsible for the hospital admission of elderly in the United States. It is associated with increased mortality, morbidity and an estimated cost of 1.14 billion per year (Xiao et al., 2004; Schlanger et al., 2010; Pretorius et al., 2013; Frangeskou et al., 2015). Older individuals are predisposed to dehydration encephalopathy as a result of decreased total body water (TBW) and diminished sensation of thirst. We hypothesize that thirst blunting in older individuals is the result of a defective microRNA-6842-3p failing to silence the expression of the vesicular GABA transporters (VGAT) and alpha 7 cholinergic nicotinic receptors in the subfornical organ (SFO) of the hypothalamus. We hypothesize further that resultant dehydration facilitates protein misfolding and aggregation, predisposing to neurocognitive disorders. We completed a search of predicted microRNA targets, utilizing the public domain tool miRDB and found that microRNA-6842-3p modulates the SLC6A1 and CHRNA7 genes both of which were previously hypothesized to inhibit the thirst sensation by their action on SFO. The primary aim of this article is to answer two questions: Can prevention and correction of dehydration in elderly lower age-related cognitive deterioration? Can exosomal miR-6842 in the peripheral blood predict dehydration encephalopathy in elderly? PMID:27252943

  14. Dehydration and Cognition in Geriatrics: A Hydromolecular Hypothesis.

    PubMed

    Sfera, Adonis; Cummings, Michael; Osorio, Carolina

    2016-01-01

    Dehydration is one of the ten most frequent diagnoses responsible for the hospital admission of elderly in the United States. It is associated with increased mortality, morbidity and an estimated cost of 1.14 billion per year (Xiao et al., 2004; Schlanger et al., 2010; Pretorius et al., 2013; Frangeskou et al., 2015). Older individuals are predisposed to dehydration encephalopathy as a result of decreased total body water (TBW) and diminished sensation of thirst. We hypothesize that thirst blunting in older individuals is the result of a defective microRNA-6842-3p failing to silence the expression of the vesicular GABA transporters (VGAT) and alpha 7 cholinergic nicotinic receptors in the subfornical organ (SFO) of the hypothalamus. We hypothesize further that resultant dehydration facilitates protein misfolding and aggregation, predisposing to neurocognitive disorders. We completed a search of predicted microRNA targets, utilizing the public domain tool miRDB and found that microRNA-6842-3p modulates the SLC6A1 and CHRNA7 genes both of which were previously hypothesized to inhibit the thirst sensation by their action on SFO. The primary aim of this article is to answer two questions: Can prevention and correction of dehydration in elderly lower age-related cognitive deterioration? Can exosomal miR-6842 in the peripheral blood predict dehydration encephalopathy in elderly? PMID:27252943

  15. Difference in dehydration condition and variation in amount of dehydration water: a possible origin of HIMU-FOZO-PREMA reservoirs

    NASA Astrophysics Data System (ADS)

    Shimoda, G.; Kogiso, T.

    2015-12-01

    Isotopic composition of the ocean island basalts (OIB) are commonly explained by mixing of mantle reservoirs, such as depleted MORB mantle (DMM), HIMU (high-u: u = 238U/204Pb) EM1 (Enriched Mantle 1) and EM2. In addition, reservoirs whose isotopic compositions are common and intermediate has been pointed out, such as, FOZO (Focal Zone) and PREMA (Prevalent Mantle). Although these intermediate reservoirs have been used to describe the isotopic distribution of OIB, geochemical relationship between the intermediate and conventional reservoirs are still ambiguous. To elucidate the relationship, geochemical modeling has been conducted that focuses on origin of HIMU, FOZO, and PREMA. Our model includes magma differentiation process at mid-ocean ridges and variable dehydration conditions at subduction zones. The effect of magma differentiation process at a mid-ocean ridge was estimated by comparing the chemical composition of common and differentiated MORBs, which are determined based on the magnesium number of MORB. The variation in dehydration conditions are examined with different amount of water of dehydration with partition coefficients of aqueous and supercritical fluids reported by Kessel et al. (2005). The results suggest that the common MORBs without subduction modification could evolve to have isotopic signatures of PREMA after ca. 1-2 Ga since they are recycled back into the mantle, suggesting the importance of recycling of "dry" MORBs. In contrast, intensively dehydrated common MORBs can produce the FOZO isotopic signatures. Thus, variation in amount of dehydration water could be responsible for the FOZO-PREMA isotopic array. For the production of HIMU isotopic signature, additional conditions may be required, i.e., prolonged dehydration from sub-arc to sub-backarc. Difference in dehydration pressure could induce chemical fractionation between Pb, Th and U. We also found that only the strongly dehydrated differentiated MORBs can produce extreme HIMU isotopic

  16. Effects of fixation, dehydration and staining on dimensions of myxosporidan.

    PubMed

    Parker, J D; Warner, M C

    1970-10-01

    The effects of fixation, dehydration and staining on the morphological dimensions of myxo- and microsporidan spores were tested. Seven fixatives, two dehydrants and five stains were tested. Ten % formalin produced the least shrinkage and provided the best cytological detail of fixed material in both types of spores. All fixatives caused shrinkage of myxosporidan spore length and polar capsule length. Spore capsule width and polar capsule width were unaffected by 10% formalin. Ethyl alcohol caused no significant change in spore width. Microsporidan spore length shrunk with all fixatives, but spore width was generally unaffected. Dehydration, with either isopropyl alcohol or acetone, produced additional, significant shrinkage. The influence of stains on spore size was negligible. Heidenhains iron hematoxylin followed by eosin, and Mallory's analine-blue collagen stain, effectively stained myxo- and microsporidan spores. PMID:16512155

  17. Dehydration of glycerol over niobia-supported silicotungstic acid catalysts.

    PubMed

    Lee, Young Yi; Ok, Hye Jeong; Moon, Dong Ju; Kim, Jong Ho; Park, Nam Cook; Kim, Young Chul

    2013-01-01

    Liquid-phase dehydration of glycerol to acrolein over nanosized niobia-supported silicotungstic acid catalysts was performed to investigate the effect of the silicotungstic acid loading on the catalytic performance of the catalysts. The catalysts were prepared by following an impregnation method with different HSiW loadings in the range of 10-50 wt%. The prepared catalysts were characterized by N2 physisorption, XRD, FT-IR, TPD of ammonia, and TGA. Dehydration of glycerol was conducted in an autoclave reactor under the conditions of controlled reaction temperatures under corresponding pressure. Increasing HSiW loading rapidly increased the acidity of HSiW/Nb205 catalyst and rate of glycerol conversion, but acrolein selectivity decreased due to enhanced deactivation of the catalyst by carbon deposit. Consequently, it was confirmed that catalytic activity for the dehydration of glycerol to acrolein was dependant on the acidity of catalyst and can be controlled by HSiW loading. PMID:23646735

  18. Isothermal dehydration of thin films of water and sugar solutions

    NASA Astrophysics Data System (ADS)

    Heyd, R.; Rampino, A.; Bellich, B.; Elisei, E.; Cesàro, A.; Saboungi, M.-L.

    2014-03-01

    The process of quasi-isothermal dehydration of thin films of pure water and aqueous sugar solutions is investigated with a dual experimental and theoretical approach. A nanoporous paper disk with a homogeneous internal structure was used as a substrate. This experimental set-up makes it possible to gather thermodynamic data under well-defined conditions, develop a numerical model, and extract needed information about the dehydration process, in particular the water activity. It is found that the temperature evolution of the pure water film is not strictly isothermal during the drying process, possibly due to the influence of water diffusion through the cellulose web of the substrate. The role of sugar is clearly detectable and its influence on the dehydration process can be identified. At the end of the drying process, trehalose molecules slow down the diffusion of water molecules through the substrate in a more pronounced way than do the glucose molecules.

  19. Geothermal vegetable dehydration at Brady`s Hot Springs, Nevada

    SciTech Connect

    Lund, J.W.

    1994-07-01

    This article describes the utilization of the Brady`s Springs geothermal resource for heat generation used in the food dehydration process. This geothermal system is located in the Forty-Mile Desert area of Nevada. Geothermal Food Processors, Inc. of Reno, Nevada started construction of the geothermal vegetable dehydration plant in 1978, and the plant started operations in 1979. The industrial process of vegetable dehydration at the plant is described. In July of 1992, the Brady`s Springs geothermal system began being used for power generation by the Brady`s Hot Springs geothermal power plant, operated by Oxbow Power Services, Inc. As a result, the water levels in the food processing plant wells have dropped below usable levels and the geothermal brine is now being supplied by the Oxbow power plant.

  20. Isothermal dehydration of thin films of water and sugar solutions

    SciTech Connect

    Heyd, R.; Rampino, A.; Bellich, B.; Elisei, E.; Cesàro, A.; Saboungi, M.-L.

    2014-03-28

    The process of quasi-isothermal dehydration of thin films of pure water and aqueous sugar solutions is investigated with a dual experimental and theoretical approach. A nanoporous paper disk with a homogeneous internal structure was used as a substrate. This experimental set-up makes it possible to gather thermodynamic data under well-defined conditions, develop a numerical model, and extract needed information about the dehydration process, in particular the water activity. It is found that the temperature evolution of the pure water film is not strictly isothermal during the drying process, possibly due to the influence of water diffusion through the cellulose web of the substrate. The role of sugar is clearly detectable and its influence on the dehydration process can be identified. At the end of the drying process, trehalose molecules slow down the diffusion of water molecules through the substrate in a more pronounced way than do the glucose molecules.

  1. Ice Cloud Formation and Dehydration in the Tropical Tropopause Layer

    NASA Technical Reports Server (NTRS)

    Jensen, Eric; Pfister, Leonhard; Gore, Warren J. (Technical Monitor)

    2002-01-01

    Stratospheric water vapor is important not only for its greenhouse forcing, but also because it plays a significant role in stratospheric chemistry. several recent studies have focused on the potential for dehydration due to ice cloud formation in air rising slowly through the tropical tropopause layer. Holton and Gettelman showed that temperature variations associated with horizontal transport of air in the tropopause layer can drive ice cloud formation and dehydration, and Gettelman et al. recently examined the cloud formation and dehydration along kinematic trajectories using simple assumptions about the cloud properties. In this study, we use a Lagrangian, one-dimensional cloud model to further investigate cloud formation and dehydration as air is transported horizontally and vertically through the tropical tropopause layer. Time-height curtains of temperature are extracted from meteorological analyses. The model tracks the growth and sedimentation of individual cloud particles. The regional distribution of clouds simulated in the model is comparable to the subvisible cirrus distribution indicated by SAGE II. The simulated cloud properties depend strongly on the assumed ice supersaturation threshold for ice nucleation. with effective nuclei present (low supersaturation threshold), ice number densities are high (0.1--10 cm(circumflex)-3), and ice crystals do not grow large enough to fall very far, resulting in limited dehydration. With higher supersaturation thresholds, ice number densities are much lower (less than 0.01 cm(circumflex)-3), and ice crystals grow large enough to fall substantially; however, supersaturated air often crosses the tropopause without cloud formation. The clouds typically do not dehydrate the air along trajectories down to the temperature minimum saturation mixing ratio. Rather the water vapor mixing ratio crossing the tropopause along trajectories is typically 10-50% larger than the saturation mixing ratio.

  2. Ductile Deformation of Dehydrating Serpentinite Evidenced by Acoustic Signal Monitoring

    NASA Astrophysics Data System (ADS)

    Gasc, J.; Hilairet, N.; Wang, Y.; Schubnel, A. J.

    2012-12-01

    Serpentinite dehydration is believed to be responsible for triggering earthquakes at intermediate depths (i.e., 60-300 km) in subduction zones. Based on experimental results, some authors have proposed mechanisms that explain how brittle deformation can occur despite high pressure and temperature conditions [1]. However, reproducing microseismicity in the laboratory associated with the deformation of dehydrating serpentinite remains challenging. A recent study showed that, even for fast dehydration kinetics, ductile deformation could take place rather than brittle faulting in the sample [2]. This latter study was conducted in a multi-anvil apparatus without the ability to control differential stress during dehydration. We have since conducted controlled deformation experiments in the deformation-DIA (D-DIA) on natural serpentinite samples at sector 13 (GSECARS) of the APS. Monochromatic radiation was used with both a 2D MAR-CCD detector and a CCD camera to determine the stress and the strain of the sample during the deformation process [3]. In addition, an Acoustic Emission (AE) recording setup was used to monitor the microseismicity from the sample, using piezo-ceramic transducers glued on the basal truncation of the anvils. The use of six independent transducers allows locating the AEs and calculating the corresponding focal mechanisms. The samples were deformed at strain rates of 10-5-10-4 s-1 under confining pressures of 3-5 GPa. Dehydration was triggered during the deformation by heating the samples at rates ranging from 5 to 60 K/min. Before the onset of the dehydration, X-ray diffraction data showed that the serpentinite sustained ~1 GPa of stress which plummeted when dehydration occurred. Although AEs were recorded during the compression and decompression stages, no AEs ever accompanied this stress drop, suggesting ductile deformation of the samples. Hence, unlike many previous studies, no evidence for fluid embrittlement and anticrack generation was found

  3. The solvent-free thermal dehydration of tetritols on zeolites.

    PubMed

    Kurszewska, M; Skorupa, E; Kasprzykowska, R; Sowiński, P; Wiśniewski, A

    2000-06-30

    A new alditol dehydration method at high temperatures, in the presence of molecular sieves without solvent in an argon atmosphere, is described. Investigations on tetritols have been carried out. Products arising after the intramolecular and intermolecular elimination of water, with retention or inversion of the configuration of asymmetric carbon atoms, were observed. Complete analytical separation of reaction products was achieved by means of GLC. The chemical structures of the compounds obtained were assigned using co-injection with standards, GLC-CIMS and GLC-EIMS analyses. Two intermolecular dehydration products of tetritols were isolated by HPLC and identified by 1H and 13C NMR spectroscopy. PMID:10890272

  4. Process and apparatus for dehydrating waste solids concentrates

    SciTech Connect

    Bonanno, A.J.; Greenfield, C.

    1983-03-22

    An apparatus and process for dehydrating waste solids concentrates including secondary and digested sewage sludges and those concentrates prone to form emulsions upon the addition of oil are obtained and accomplished by mixing the sludge or other concentrate with fluidizing oil prior to dehydration by heat evaporation to maintain pumpability; recycling a portion of the substantially anhydrous waste solids and oil evaporator output slurry, and admixing it with the fluidizing oil and input sludge or concentrate to regulate the solids content and viscosity of the steady state feed mixture and thereby prevent fouling of the evaporator heat transfer surfaces and convert emulsions to suspensions.

  5. EPR study on gamma-irradiated fruits dehydrated via osmosis

    NASA Astrophysics Data System (ADS)

    Yordanov, N. D.; Aleksieva, K.

    2007-06-01

    The shape and time stability of the electron paramagnetic resonance (EPR) spectra of non- and γ-irradiated papaya, melon, cherry and fig samples dehydrated via osmosis are reported. It is shown that non-irradiated samples are generally EPR silent whereas γ-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.

  6. The BUDDY (Bedside Ultrasound to Detect Dehydration in Youth) study

    PubMed Central

    2014-01-01

    Background Prior research suggests that the ratio of the ultrasound-measured diameter of the inferior vena cava to the aorta correlates with the level of dehydration in children. This study was designed to externally validate this and to access the accuracy of the ultrasound measured inspiratory IVC collapse and physician gestalt to predict significant dehydration in children in the emergency department. Methods We prospectively enrolled a non-consecutive cohort of children ≤18 years old. Patient weight, ultrasound measurements of the IVC and Ao, and physician gestalt were recorded. The percent weight change from presentation to discharge was used to calculate the degree of dehydration. A weight change of ≥5% was considered clinically significant dehydration. Receiver operating characteristic (ROC) curves were constructed for each of the ultrasound measurements and physician gestalt. Sensitivity (SN) and specificity (SP) were calculated based on previously established cutoff points of the IVC/Ao ratio (0.8), the IVC collapsibility index of 50%, and a new cut off point of IVC collapsibility index of 80% or greater. Intra-class correlation coefficients were calculated to assess the degree of inter-rater reliability between ultrasound observers. Results Of 113 patients, 10.6% had significant dehydration. The IVC/Ao ratio had an area under the ROC curve (AUC) of 0.72 (95% CI 0.53 to 0.91) and, with a cutoff of 0.8, produced a SN of 67% and a SP of 71% for the diagnosis of significant dehydration. The IVC collapsibility index of 50% had an AUC of 0.58 (95% CI 0.44 to 0.72) and, with a cutoff of 80% collapsibility, produced a SN of 83% and a SP of 42%. The intra-class correlation coefficient was 0.83 for the IVC/Ao ratio and 0.70 for the IVC collapsibility. Physician gestalt had an AUC of 0.61 (95% CI 0.44 to 0.78) and, with a cutoff point of 5, produced a SN of 42% and a SP of 65%. Conclusions The ultrasound-measured IVC/Ao ratio is a modest predictor of significant

  7. DEHYDRATION OF ALCOHOLS VIA PREVAPORATION USING A NOVEL HYDROPHILIC MEMBRANE

    EPA Science Inventory

    Pervaporation has emerged as an economically viable alternative technology for the dehydration of organic solvents, removal of organic compounds from water and organic/organic separations. Development of a suitable membrane system with high flux and high selectivity plays a criti...

  8. DEHYDRATION OF ALCOHOLS VIA PERVAPORATION USING A NOVEL HYDROHILIC MEMBRANE

    EPA Science Inventory

    Pervaporation has emerged as an economically viable alternative technology for the dehydration of organic solvents, removal of organic compounds from water and organic/organic separations. Development of a suitable membrane system with high flux and high selectivity plays a criti...

  9. Study of wound dressing structure and hydration/dehydration properties

    NASA Astrophysics Data System (ADS)

    Lugão, A. B.; Machado, L. D. B.; Miranda, L. F.; Alvarez, M. R.; Rosiak, J. M.

    1998-06-01

    Hydrogels manufactured by radio-induced crosslinking and simultaneous sterilisation of hydrogels of PVP, PEG and agar, according to the Rosiak method, have many desirable properties for using as wound dressings. However, some properties need to be improved or better controlled. The membranes need to be strong enough to be freely used. Another important property to be controlled is the capacity of absorption of exudate and the kinetics of drying. Therefore, it was necessary to understand the role of main parameters (agar, PVP, PEG concentration and dose) in the structure of the net and in the hydration and dehydration properties. The structure of the membranes was studied by sol analysis and the hydrating/dehydrating properties were studied by isothermal thermogravimetric analysis. The gel content for all samples were always in agreement with expected values considering that only PVP undergoes crosslinking. The hydrating and dehydration results did not show variation with the tested parameters. It was concluded that the network was solely composed of crosslinked PVP plasticezed by the other compounds. The properties of hydration/dehydration is related rather to diffusion than to capillarity or osmose and to the chemical retention of water in the polymeric matrix.

  10. Science Study Aids 1: Dehydration for Food Preservation.

    ERIC Educational Resources Information Center

    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. Microfluidic Droplet Dehydration for Concentrating Processes in Biomolecules

    NASA Astrophysics Data System (ADS)

    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.

  12. Increased efficiency using the encapsulation-dehydration cryopreservation technique

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Arabidopsis thaliana shoot tips were successfully cryopreserved using encapsulation-dehydration cryopreservation methods. Between one and seven shoot tips were encapsulated within 4 mm calcium-alginate beads. Beads were formed in the presence of 2 M glycerol+0.4M sucrose. The time required to mak...

  13. POULTRY EXCRETA DEHYDRATION AND UTILIZATION: SYSTEM DEVELOPMENT AND DEMONSTRATION

    EPA Science Inventory

    A manure handling and drying system involving caged layers with daily manure collection, air drying, and dehydration in a flash-type dryer has been studied. Objectives of the study were to: (1) Develop a complete manure handling system to maximize pollution control; (2) determine...

  14. Diagnosis of Pneumonia in Children with Dehydrating Diarrhoea

    PubMed Central

    Ronan, Anne; Khan, Wasif Ali; Salam, Mohammed Abdus

    2014-01-01

    The World Health Organization (WHO) guidelines for diagnosis of pneumonia are based on the history of cough or difficult breathing and age-adjusted respiration rates. Metabolic acidosis associated with dehydrating diarrhoea also influences the respiration rate. Two hundred and four children, aged 2 to 59 months, with dehydrating diarrhoea and a history of cough and/or fast breathing, were enrolled in a prospective study. Pneumonia diagnoses were made on enrollment and again 6 hours post-enrollment (after initial rehydration), using the WHO guidelines. These were compared with investigators’ clinical diagnosis based on history and findings of physical examination and a chest x-ray at the same time points. Using the WHO guidelines, 149/152 (98%) infants in the 2-11 months age-group and 38/40 (95%) children in the 12-59 months age-group were diagnosed to have pneumonia on enrollment, which dropped to 107 (70%) and 30 (75%) respectively at 6 hours post-enrollment. The specificity of the WHO guidelines for diagnosis of pneumonia was very low (6.9%) at enrollment but increased to 65.5% at 6 hours post-enrollment, after initial rehydration. The specificity of the WHO guidelines for diagnosis of pneumonia in young children is significantly reduced in dehydrating diarrhoea. For young children with dehydrating diarrhoea, rehydration, clinical and radiological assessments are useful in identifying those with true pneumonia. PMID:24847588

  15. Slab dehydration and deep water recycling through time

    NASA Astrophysics Data System (ADS)

    Magni, Valentina; Bouilhol, Pierre; van Hunen, Jeroen

    2015-04-01

    The fate of water in subduction zones is a key feature that influences the magmatism of the arcs, the rheology of the mantle, and the recycling of volatiles. We investigate the dehydration processes in subduction zones and their implications for the water cycle throughout Earth's history. We use a numerical tool that combines thermo-mechanical models with a thermodynamic database to examine slab dehydration for present-day and early Earth settings and its consequences for the deep water recycling. We investigate the reactions responsible for releasing water from the crust and the hydrated lithospheric mantle and how they change with subduction velocity, slab age, and mantle potential temperature. Our results show that faster slabs dehydrate over a wide area: they start dehydrating shallower and they carry water deeper into the mantle. A hotter mantle (i.e., early Earth setting) drives the onset of crustal dehydration slightly shallower, but, mostly, dehydration reactions are very similar to those occurring in present-day setting. However, for very fast slabs and very hot mantle epidote is involved as a dehydrating crustal phase. Moreover, we provide a scaling law to estimate the amount of water that can be carried deep into the mantle. We generally observe that a 1) 100°C increase in the mantle temperature, or 2) ~15 Myr decrease of plate age, or 3) decrease in subduction velocity of ~2 cm/yr all have the same effect on the amount of water retained in the slab at depth, corresponding to a decrease of ~2.2x105 kg/m2 of H2O. We estimate that for present-day conditions ~26% of the global influx water, or 7x108 Tg/Myr of H2O, is recycled into the mantle. Using a realistic distribution of subduction parameters, we illustrate that deep water recycling might still be possible in early Earth conditions, although its efficiency would generally decrease. Indeed, 0.5-3.7x108 Tg/Myr of H2O could still be recycled in the mantle at 2.8 Ga.

  16. 40 CFR 407.50 - Applicability; description of the dehydrated potato products subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 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...

  17. 40 CFR 407.50 - Applicability; description of the dehydrated potato products subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 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...

  18. 40 CFR 407.50 - Applicability; description of the dehydrated potato products subcategory.

    Code of Federal Regulations, 2010 CFR

    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...

  19. 40 CFR 407.50 - Applicability; description of the dehydrated potato products subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 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...

  20. 40 CFR 407.50 - Applicability; description of the dehydrated potato products subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 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...

  1. 40 CFR 63.1275 - Glycol dehydration unit process vent standards.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 12 2014-07-01 2014-07-01 false Glycol dehydration unit process vent... Storage Facilities § 63.1275 Glycol dehydration unit process vent standards. (a) This section applies to each glycol dehydration unit subject to this subpart that must be controlled for air emissions...

  2. 40 CFR 63.765 - Glycol dehydration unit process vent standards.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 11 2012-07-01 2012-07-01 false Glycol dehydration unit process vent... Facilities § 63.765 Glycol dehydration unit process vent standards. (a) This section applies to each glycol dehydration unit subject to this subpart with an actual annual average natural gas flowrate equal to...

  3. 40 CFR 63.1275 - Glycol dehydration unit process vent standards.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 12 2013-07-01 2013-07-01 false Glycol dehydration unit process vent... Storage Facilities § 63.1275 Glycol dehydration unit process vent standards. (a) This section applies to each glycol dehydration unit subject to this subpart that must be controlled for air emissions...

  4. 40 CFR 63.1275 - Glycol dehydration unit process vent standards.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 12 2012-07-01 2011-07-01 true Glycol dehydration unit process vent... Facilities § 63.1275 Glycol dehydration unit process vent standards. (a) This section applies to each glycol dehydration unit subject to this subpart with an actual annual average natural gas flowrate equal to...

  5. 40 CFR 63.765 - Glycol dehydration unit process vent standards.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 11 2013-07-01 2013-07-01 false Glycol dehydration unit process vent... Facilities § 63.765 Glycol dehydration unit process vent standards. (a) This section applies to each glycol dehydration unit subject to this subpart that must be controlled for air emissions as specified in...

  6. 40 CFR 63.765 - Glycol dehydration unit process vent standards.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 11 2014-07-01 2014-07-01 false Glycol dehydration unit process vent... Facilities § 63.765 Glycol dehydration unit process vent standards. (a) This section applies to each glycol dehydration unit subject to this subpart that must be controlled for air emissions as specified in...

  7. 40 CFR 63.1275 - Glycol dehydration unit process vent standards.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 11 2011-07-01 2011-07-01 false Glycol dehydration unit process vent... Facilities § 63.1275 Glycol dehydration unit process vent standards. (a) This section applies to each glycol dehydration unit subject to this subpart with an actual annual average natural gas flowrate equal to...

  8. 40 CFR 63.1275 - Glycol dehydration unit process vent standards.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Glycol dehydration unit process vent... Facilities § 63.1275 Glycol dehydration unit process vent standards. (a) This section applies to each glycol dehydration unit subject to this subpart with an actual annual average natural gas flowrate equal to...

  9. Dehydration Kinetics of Volterra Gypsum: Experiments and Overview

    NASA Astrophysics Data System (ADS)

    Llana-Funez, S.; Wheeler, J.; Faulkner, D.

    2007-12-01

    Dehydration reactions are often envisaged as a triggering mechanism for seismicity in rocks under tectonic loads due to the reduction in effective pressure during the release of fluids that may eventually produce mechanical embrittlement. Understanding of metamorphic transformation in deforming rocks is even more important in fault zones where periods of seismic slip are reported. Dehydration of gypsum under controlled conditions, in laboratory experiments and in numerical models, provides information on deformation processes operating in seismically active regions and may be of help in understanding their cyclicity and their evolution. Two series of simple heating experiments of Volterra gypsum samples at room pressure, using intact and powdered specimens, provide reference data for further experiments under confining and differential stress during dehydration. Heating experiments were run at constant temperature between 80 degC and 140 °C in intact specimens and at 86 °C and 97 °C using powders with five different grain size fractions: <0.063, 0.063-0.125, 0.125-0.25, 0.25-0.5 and >0.5 mm. The complete dehydration of 1 mol of gypsum produces 1 mol of anhydrite and two moles of water generating a porosity of about 38% and implying a weight loss of 21% upon removal of water. The progressive loss of weight during dehydration was used as the method to estimate the progress of the reaction. The reaction is characterized by an initial stage under 10% reaction were reaction rate accelerates, which is followed by a linear stage for about 50 to 70% of the reaction and a final third stage with decelerating reaction rates. All tests run above 85 °C reached about 90% reaction. Those below 85 °C seem to converge to a lower final fraction (75%) suggesting partial dehydration, very likely to bassanite. The temperature dependence of the linear rates indicates in an Arrhenius plot that the full dehydration of gypsum has an activation enthalpy of 96 kJ/mol. The two

  10. Hydrothermal Dehydration of Aqueous Fructose Solutions in a Closed System

    SciTech Connect

    Yao, Chunhua; Shin, Yongsoon; Wang, Li Q.; Windisch, Charles F.; Samuels, William D.; Arey, Bruce W.; Wang, Chong M.; Risen Jr., William M.; Exarhos, Gregory J.

    2007-10-25

    The synthesis of materials with targeted size and shape has attracted much attention. Specifically, colloidal spheres with targeted and uniform sizes have opened the door for a variety of applications associated with drug delivery, and manipulation of light (photonic band-gap crystals). Surface modification is a key to realizing many of these applications owing to the inherent inert surface.The remarkable transformation of carbohydrate molecules including sugars to homogeneous carbon spheres is found to readily occur by a dehydration mechanism and subsequent sequestering in aqueous solutions that are heated at 160-180oC in a pressurized vessel. Under such conditions, these molecules actually dehydrate even though they are dissolved in water. Size-tunable metal and metal oxides with uniform shells have also been prepared by using carbon spheres as templates.

  11. Dehydration and oxidation of cellulose hydrolysis products in acidic solution

    SciTech Connect

    Garves, K.

    1981-01-01

    The dehydration of cotton cellulose in aqueous solutions in the presence of Ac/sub 2/O, AcOH, HCl, H/sub 2/SO/sub 4/ or HBr proceeded by hydrolysis to carbohydrates with acetate groups, followed by conversion to 5-(hydroxymethyl)furfural (I) and then, to levulinic acid (II) accompanied by humic acids. For the formation of I, HCl was a more efficient and selective catalyst than H/sub 2/SO/sub 4/, and the formation of II was promoted by high acid and H/sub 2/O concentrations in the medium. The addition of FeCl/sub 3/ to the dehydration mixture with HCl and continuous distillation led to the isolation of furfural.

  12. Methods for dehydration of sugars and sugar alcohols

    DOEpatents

    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.

  13. Hydration and dehydration of zeolitic tuff from Yucca Mountain, Nevada

    SciTech Connect

    Kranz, R.L.; Bish, D.L.; Blacic, J.D. )

    1989-10-01

    Naturally occurring zeolites expand and contract when hydrated or dehydrated. In tuffaceous rock composed largely of such zeolites, the entire rock may swell or contract significantly as the rock becomes saturated or dries out. If such rock is constrained, significant stresses may develop as a result of hydration or dehydration. We present experimental results that substantiates this. In a zeolitized, non-welded tuff from Yucca Mountain, NV, rock permeability governs the swelling rate since the major constituent, clinoptilolite, hydrates as fast as it can be exposed to water. At Yucca Mountain, where a nuclear waste repository is proposed, strata of welded, devitrified tuff overlie non-welded, zeolitic tuff. Should the hydration state of the units change significantly over the repository lifetime, additional stresses on the same order of magnitude as now exist may develop. {copyright} American Geophysical Union 1989

  14. Improvements in the order, isotropy and electron density of glypican-1 crystals by controlled dehydration

    SciTech Connect

    Awad, Wael; Svensson Birkedal, Gabriel; Thunnissen, Marjolein M. G. M.; Mani, Katrin; Logan, Derek T.

    2013-12-01

    The anisotropy of crystals of glypican-1 was significantly reduced by controlled dehydration using the HC1 device, allowing the building of previously disordered parts of the structure. The use of controlled dehydration for improvement of protein crystal diffraction quality is increasing in popularity, although there are still relatively few documented examples of success. A study has been carried out to establish whether controlled dehydration could be used to improve the anisotropy of crystals of the core protein of the human proteoglycan glypican-1. Crystals were subjected to controlled dehydration using the HC1 device. The optimal protocol for dehydration was developed by careful investigation of the following parameters: dehydration rate, final relative humidity and total incubation time T{sub inc}. Of these, the most important was shown to be T{sub inc}. After dehydration using the optimal protocol the crystals showed significantly reduced anisotropy and improved electron density, allowing the building of previously disordered parts of the structure.

  15. A wideband scalar network analyzer for biomedical dehydration measurements.

    PubMed

    Hofmann, M; Nehring, J; Weigel, R; Fischer, G; Kissinger, D

    2013-01-01

    This paper presents a wideband microwave approach towards biomedical dehydration monitoring. The introduced concept is verified via invasive measurements on several blood samples. A microwave measurement circuit, based of a two-port scalar vector network analyzer is presented. The circuit operates between 5GHz and 20GHz using a planar permittivity sensor. Measurements of all subcomponents are shown together with measurements of a Water-NaCl-Glycerol solution. PMID:24110621

  16. Metabolic Acidosis Without Clinical Signs of Dehydration in Young Calves

    PubMed Central

    Kasari, T. R.; Naylor, J. M.

    1984-01-01

    Metabolic acidosis without clinical signs of dehydration was diagnosed in four calves between nine and 21 days of age. In each calf either coma or depression with weakness and ataxia was observed. Two calves had slow deep respirations. Treatment with intravenous administration of solutions of sodium bicarbonate was accompanied by a rise in blood pH and a return to normal demeanor, ambulation and appetites, allowing these calves to return to their respective herds. ImagesFigure 1. PMID:17422463

  17. Dehydration-induced porosity waves and episodic tremor and slip

    NASA Astrophysics Data System (ADS)

    Skarbek, Rob M.; Rempel, Alan W.

    2016-02-01

    Episodic tremor and slip (ETS) along the subduction interface takes place where there is abundant evidence for elevated, near-lithostatic pore pressures, at sufficiently great depths (30-45 km) that chemical dehydration reactions must act as their dominant source. We simulate fluid and heat flow while tracking the location of a vertically oriented, one-dimensional column of material as it subducts through the slow slip and tremor zone. The material in the column is transformed through a pressure-dependent and temperature-dependent dehydration reaction that we describe with a generalized nonlinear kinetic rate law. Column deformation is largely dominated by viscous creep, with a closure rate that depends linearly on porosity. This behavior causes the dehydration reaction to generate traveling porosity waves that transport increased fluid pressures within the slow slip region. To explore the possibility that the observed periodicity of slow slip and tremor in subduction zones can be explained by the migration of such porosity waves, we derive a dispersion relation that accurately describes our numerical results. We also obtain an expression for how the thickness of the dehydrating layer is expected to vary as a function of the parameters in the reaction rate law. Although the amplitudes of pore pressure perturbations rival those that are produced by known external forcings (e.g., tides or passing surface waves), our analysis suggests that given reasonable estimates of rock viscosity, permeabilities in the range 6.5×10-15 to 5×10-10 m2 are required for porosity wave trains to form at periods comparable to those of slow slip and tremor.

  18. 30. BUILDING NO. 527, DEHYDRATING PRESSES, LOOKING SOUTH. ALUMINUM NARROWGUAGE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    30. BUILDING NO. 527, DEHYDRATING PRESSES, LOOKING SOUTH. ALUMINUM NARROW-GUAGE GONDOLA CAR IN LEFT BACKGROUND BROUGHT MOISTENED GUN COTTON FROM REST HOUSE (BUILDING NO. 320-B) IN CANS. (ONE OF THESE CANS IS ON UNLOADING PLATFORM RUNNING BESIDE PRESSES). CONTENTS OF CANS WERE UNLOADED INTO PRESSES BY HAND. - Picatinny Arsenal, 500 Area, Powder Factory & Power House, State Route 15 near I-80, Dover, Morris County, NJ

  19. 28. BUILDING NO. 527, DEHYDRATING HOUSE, LOOKING SOUTH AT NORTH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    28. BUILDING NO. 527, DEHYDRATING HOUSE, LOOKING SOUTH AT NORTH (REAR) ELEVATION OF PRELIMINARY SOLVENT RECOVERY WING. RAILS LEADING FROM DOORS CARRIED STANDARD GUAGE R.R. CARTS ONTO SMALL FLATCARS RIDING IN TRACKS IN FOREGROUND. FROM HERE THE CARS WERE TAKEN TO BUILDING NO. 533, SOLVENT RECOVERY. BUILDING NO. 540, LOADING DOCK (STORAGE FOR POWDER BUGGIES) IN BACKGROUND LEFT. - Picatinny Arsenal, 500 Area, Powder Factory & Power House, State Route 15 near I-80, Dover, Morris County, NJ

  20. The physiological effects of dehydration caused by sweat loss. [athletes

    NASA Technical Reports Server (NTRS)

    Israel, S.

    1981-01-01

    The mechanisms of fluid loss in the human body while sweating due to physical exercise are discussed. Trained and untrained persons were examined and compared. Since sweat is hypotonous, a disruption in the hydrosalinic balance occurs; the consequences of this finding, also pertaining to the fluid and electrolytic substitution, are presented. Further explanations on the problem of dehydration refer to reactions of individual organ systems, to alterations in bodily capabilities as well as to questions relating to sex and age.

  1. [A case of hypernatremic dehydration due to breast-feeding].

    PubMed

    Marzouk, M; Neffati, F; Khelifa, H; Douki, W; Monastiri, K; Gueddiche, M N; Ben Amor, A; Najjar, M F

    2008-01-01

    The authors report an 11-day-old exclusively breast-fed female, with a birth weight of 3 300 g, who had suffered from dehydration stage I, with acute renal failure and metabolic acidosis, with 170 mmol/L of serum sodium. Renal ultrasounds were normal but the rate of sodium in mother's milk was three times higher than controls (87 versus 21 mmol/L). Intravenous rehydration allowed the correction of hydroelectrolytic disorders. PMID:18725352

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

    NASA Astrophysics Data System (ADS)

    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.

  3. Dehydration of different ketoses and aldoses to 5-hydroxymethylfurfural.

    PubMed

    van Putten, Robert-Jan; Soetedjo, Jenny N M; Pidko, Evgeny A; van der Waal, Jan C; Hensen, Emiel J M; de Jong, Ed; Heeres, Hero J

    2013-09-01

    5-Hydroxymethylfurfural (HMF) is considered an important building block for future bio-based chemicals. Here, we present an experimental study using different ketoses (fructose, sorbose, tagatose) and aldoses (glucose, mannose, galactose) under aqueous acidic conditions (65 g L(-1) substrate, 100-160 °C, 33-300 mM H2 SO4 ) to gain insights into reaction pathways for hexose dehydration to HMF. Both reaction rates and HMF selectivities were significantly higher for ketoses than for aldoses, which is in line with literature. Screening and kinetic experiments showed that the reactivity of the different ketoses is a function of the hydroxyl group orientation at the C3 and C4 positions. These results, in combination with DFT calculations, point to a dehydration mechanism involving cyclic intermediates. For aldoses, no influence of the hydroxyl group orientation was observed, indicating a different rate-determining step. The combination of the knowledge from the literature and the findings in this work indicates that aldoses require an isomerization to ketose prior to dehydration to obtain high HMF yields. PMID:24039165

  4. Mass transfer kinetics during osmotic dehydration of pomegranate arils.

    PubMed

    Mundada, Manoj; Hathan, Bahadur Singh; Maske, Swati

    2011-01-01

    The mass transfer kinetics during osmotic dehydration of pomegranate arils in osmotic solution of sucrose was studied to increase palatability and shelf life of arils. The freezing of the whole pomegranate at -18 °C was carried out prior to osmotic dehydration to increase the permeability of the outer cellular layer of the arils. The osmotic solution concentrations used were 40, 50, 60°Bx, osmotic solution temperatures were 35, 45, 55 °C. The fruit to solution ratio was kept 1:4 (w/w) during all the experiments and the process duration varied from 0 to 240 min. Azuara model and Peleg model were the best fitted as compared to other models for water loss and solute gain of pomegranate arils, respectively. Generalized Exponential Model had an excellent fit for water loss ratio and solute gain ratio of pomegranate arils. Effective moisture diffusivity of water as well as solute was estimated using the analytical solution of Fick's law of diffusion. For above conditions of osmotic dehydration, average effective diffusivity of water loss and solute gain varied from 2.718 × 10(-10) to 5.124 × 10(-10) m(2)/s and 1.471 × 10(-10) to 5.147 × 10(-10) m(2)/s, respectively. The final product was successfully utilized in some nutritional formulations such as ice cream and bakery products. PMID:21535673

  5. Inhibition of chloroplastic respiration by osmotic dehydration. [Spinacia oleracea L

    SciTech Connect

    Willeford, K.O.; Ahluwalia, K.J.K.; Gibbs, M. )

    1989-04-01

    The respiratory capacity of isolated spinach (Spinacia oleracea L.) chloroplasts, measured as the rate of {sup 14}CO{sub 2} evolved from the oxidative pentose phosphate cycle in darkened chloroplasts exogenously supplied with ({sup 14}C)glucose, was progressively diminished by escalating osmotic dehydration with betaine or sorbitol. Comparing the inhibitions of CO{sub 2} evolution generated by osmotic dehydration in chloroplasts given C-1 and C-6 labeled glucose, 54% and 84%, respectively, indicates that osmotic dehydration effects to a greater extent the recycling of the oxidative pentose phosphate intermediates, fructose-6P and glyceraldehyde-3P. Respiratory inhibition in the darkened chloroplast could be alleviated by addition of NH{sub 4}Cl (a stromal alkylating agent), iodoacetamide (an inhibitor of glyceraldehyde-3P dehydrogenase), or glycolate-2P (an inhibitor of phosphofructokinase). It is concluded that the site which primarily mediates respiratory inhibition in the darkened chloroplast occurs at the fructose 1,6-bisphosphatase/phosphofructokinase junction.

  6. Inhibition of plasma vasopressin after drinking in dehydrated humans

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

    The effects of nonosmotic and nonvolumetric factors on vasopressin secretion in dehydrated humans has been investigated experimentally, before and after drinking. The subjects of the experiment were five adult men and three adult women weighing 69-77 kg. In order to determine the influence of nonosmotic and nonvolumetric factors on vasopressin secretion, measurements were obtained of the following blood hematological indices: serum Na(+) content; serum K(+) content; osmolality; and hemoglobin. Measurements of hematocrit, plasma arginine vasopressin (AVP), aldosterone, and renin activity were also obtained. It is found that dehydration increased mean serum Na(+) content, osmolality,and AVP. No significant changes were observed in renin activity, hemoglobin, hematocrit, or plasma volume, while plasma aldosterone increased from 11.1 ng/dl after dehydration to 15.6 ng/dl between 30 and 60 min after drinking. A rapid fall of AVP content following rehydration occurred in the absence of changes in the primary regulators of AVP osmolality and plasma volume, with no change in blood pressure. On the basis of the experimental results, it is suggested that oropharyngeal factors may be the mechanism, for the observed decrease in AVP following rehydration.

  7. Analysis of Dehydration and Strength in Elite Badminton Players

    PubMed Central

    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

  8. Effects of dehydration and rehydration on thermoregulatory sweating in goats.

    PubMed Central

    Baker, M A

    1989-01-01

    1. Measurement of rectal temperature (Tr), sweat rate, respiratory frequency (f) and respiratory evaporation (Eresp) were made in one Nubian and four Alpine-Toggenberg goats while they stood for 90 min in a climate chamber at 40 degrees C ambient temperature (Ta). The animals were studied when they were hydrated, when they had been dehydrated by 48 h water deprivation, and when they were rehydrated by voluntary drinking of water or saline or by intraruminal water administration. Plasma osmolality (Posm), plasma protein concentration (PP) and haematocrit (Hct) were measured before every experiment and before and after voluntary drinking. 2. Hydrated animals increased evaporation by panting and sweating during heat exposure and Tr rose about 1 degree C. The rate of sweating was as high or higher than Eresp. Dehydrated animals had lower sweat rates and higher Tr than hydrated animals, but f and Eresp were the same in hydrated and dehydrated animals. 3. When dehydrated goats were allowed to drink after 60 min of heat exposure, sweating began abruptly within 3 min of the start of drinking in every animal whether water or saline was drunk. Sweat rate returned to hydrated levels or higher before any change occurred in Posm, PP or Hct. Respiratory frequency was higher after drinking than in dehydrated animals which were not allowed to drink. 4. When water was administered by rumen tube after 60 min of heat exposure, sweating in the Nubian occurred with a short latency, similar to the onset after drinking. In the other four animals, sweating onset occurred on average at 13 min 42 s after intraruminal water administration. 5. It is concluded that sweating is a significant avenue of evaporative heat loss in these goats when they are hydrated and exposed to high Ta. Sweat rate is markedly reduced after water deprivation but returns to hydrated levels within 3 min after the start of drinking. The rapid recovery of sweating after voluntary drinking is not initiated by changes in

  9. Slab dehydration recorded in subducted serpentine sea-mount

    NASA Astrophysics Data System (ADS)

    Okamoto, K.; Fukumura, S.; Ishimori, C.; Jung, H.

    2014-12-01

    It has been considered that there is a correlation between the double seismic zones and metamorphic dehydration reaction in deep slab. The lower seismic plane of the double seismic zone is considered to be located on the 600 oC isotherm in the subducting lithosphere. Antigorite terminal reaction is highly temperature sensitive around 600 oC. Therefore it has been proposed that the oceanic lithosphere was hydrated forming serpentine prior to subduction, then serpentine was decomposed to release fluid causing dehydration embrittlement in the slab. In order to unravel relation between dehydration and seismic deformation, we have investigated dehydration process of natural metamorphic rocks recording very cold geothermal history in the crust and lithosphere in the slab. Metamorphic olivine after antigorite has been described in Italian Alps and also from the Mt. Shiraga, Japan [1]. However, the olivine was formed with talc and fluid by antigorite breakdown reaction in pressures lower than 1.5 GPa. Spinifex olivine with opx in the Cerro del Almirez [2], is the product at pressures (P > 1.5 GPa) relevant to the lower seismic plane beneath Northeast Japan. It clearly indicates the presence of large amount of water facilitate crystallization of elongated olivine with opx. It is also supported by LPO pattern of olivines determined by EBSD. Fine-grained olivine-rich samples shows that Type-C fabric pattern is dominant, suggesting deformation under water-rich condition [3]. With metamorphic olivines, chlorite was also recrystallized, suggesting that water would be transported farther down to deep. The estimated dehydration reaction has a negative P-T slope at pressures higher than 1.5 GPa. The reaction is volume reducing reaction and the olivine-opx spinifex texture was formed under volume reducing reaction. In the warm slab beneath SW Japan, the reaction has a positive slope in P-T space and forms olivine+talc+fluid. From microstrucral and petrological analysis of the

  10. Gunion - Nevada`s most innovative geothermal food dehydration facility

    SciTech Connect

    Trexler, D.T.; Taylan, G.; Stewart, M.B.; Baker, S.

    1995-12-31

    The Gunion (garlic and onion) dehydration plant, owned and operated by Integrated Ingredients, a Division of Burns Philp Food, Incorporated, uses geothermal fluids at a temperature of 306{degrees}F to dehydrate 50 to 70-thousand pounds per day of garlic and onions. The geothermal fluids are provided by Empire Farms, who has the rights for development of the resource and is the lease holder of fee land known as the Kosmos Lease. The San Emidio KGRA is located in northern Washoe County, 90 miles north-northeast of Reno, Nevada and 20 miles south of Gerlach, Nevada. Geothermal fluids exit the plant at 242{degrees}F and are piped to an injection well located 3,000 feet south-southwest of the plant. The plant location was selected not only for the geothermal resource, but also for the area`s low relative humidity. Currently, 1100-1200 gpm of geothermal fluids, at an inlet temperature of 302{degrees}F, are sufficient to provide the dryer line with ample BTU`s. Three geothermal wells drilled to depths ranging from 493 to 1817 feet produce fluids ranging in temperature from 266 to 306{degrees}F. One well can easily provide the heat required by the dryer line and will be capable of providing heat for a planned three-fold expansion of the facility. The remaining two wells are used as backup, or may be used for other applications such as soil sterilization. The fluid exiting the plant at 242{degrees}F may be cascaded and used for greenhouses and soil warming in the future. Geothermal heat is also used to dehumidify onions placed in the cold storage facility. The dehydration process takes 5-6 hours to dry the product to a 4.5% moisture content. The dried product is then milled to various sizes from powder to granules. The dehydration plant operates 24 hours/day 7 days a week. Currently 80 people are employed full-time at the plant. The dehydrated onion and garlic are used in condiments, soups, sauces and salad dressing.

  11. [Preparation and analysis of dehydrated mixtures of vegetables and underutilized fish species flours: I. Dehydrated mixtures of cereal-fish].

    PubMed

    Luna, G; Rey, J L; Castro, L M; Corona, N; Ferreiros, E; Luzardo, M

    1990-09-01

    For the purpose of providing possible solutions to the malnutrition problems affecting those populations where cereals and tubers form an important portion of their daily intake, products were prepared from dehydrated mixtures of cereals and under-utilized fish, but which contain high-quality protein. Two cereals were selected for our experiments: rice and corn, and a marine under-utilized fish species (Macrodon ancyclodon). The minced fish muscle recovered by mechanical deboning was mixed with the cereal, obtaining mixtures with 5%, 10% and 15% fish on a dry basis. Feeding experiments using Wistar weaning rats were then carried out to evaluate the most important characteristics. An amino acid profile which reflected high-quality protein was obtained, as evidenced by the excellent PER, NPU, NPR and digestibility values determined. The dehydrated mixtures of fish/cereal flour prepared with 5% and up to 10% fish (dry basis), did not present any odour, but as of the 15% level, fish odour was perceived. Therefore, the use of dehydrated mixtures of fish/cereal flours with up to 10% fish in preparing food products, is recommended, since these would be of great help in solving the scarcity of good-quality protein, particularly in the developing countries. PMID:2134143

  12. Impact of dehydration on a full body resistance exercise protocol.

    PubMed

    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. PMID:20066432

  13. Thirst perception and drinking in euhydrate and dehydrate human subjects.

    PubMed

    Obika, L F O; Idu, F K; George, G O; Ajayi, O I; Mowoe, R S

    2009-06-01

    Studies on how the body senses the need to correct extracellular and intracellular volumes and ionic concentration changes is relatively scanty. The present studies were designed to determine the effect of oral distilled water (DW) and saline loads, gargling with DW and DW preload on thirst perception (TP) and drinking in euhydrate and dehydrated subjects. The subjects were healthy male volunteers between the ages of 17 and 35 years. Group A subjects were given DW or various concentrations of sodium chloride [NaCl] orally. Subjects in groups B, C and D were dehydrated for 18 hours before the experiment. Group B gargled 500 ml of DW in divided volume of 50 ml at five minutes interval over a period of 50 minutes. Group C gargled with DW and different concentrations of NaCl. Group D were preloaded with four volumes of DW before ad libitum DW intake. TP was rated using the Visual Analogue Scale. Results showed that in Group A, drinking DW reduced TP, suggesting that baseline TP in normal euhydrate subjects is slightly elevated. Drinking DW reduced TP more than drinking NaCl solutions. Gargling resulted in a gradual fall in TP. The decrease in TP was statistically significant after 30 minutes of gargling. Gargling with different concentrations of NaCl solutions resulted in significant reductions in TP in all the groups. There was a significant decrease in TP in the group preloaded with 1000 ml of distilled water at 5 minutes of rehydration. At 20 minutes TP was abolished suggesting that approximately 1000 ml of water was needed for the rehydration. These results show that baseline TP in euhydrates is elevated and that TP increases in dehydrated subjects. Gargling reduces TP, but did not abolish thirst. It is suggested that a fall in plasma osmolality due to drinking may be responsible for abolishing thirst. PMID:19826461

  14. [Osmotic dehydration of apple (Grany Smith) with different osmotic solutions].

    PubMed

    Mercado-Silva, E; Vidal-Brotons, D

    1994-06-01

    The process of osmotic dehydration in apple rings at 40 degrees, 50 degrees and 60 degrees C in two osmotic agents were studied. The agents were similar in concentration, water activity and viscosity but differed in composition. The weight loss, water content, solids uptake and Brix showed differences in the medius studied. In syrup corn medium, the weight loss was higher and the solids uptake was lower than syrup sucrose. The polysacharides from the syrup corn lowered solutes uptake and the water out was facilited. PMID:7733790

  15. Dehydration of incoming sediments at the Japan Trench

    NASA Astrophysics Data System (ADS)

    Shimizu, M.; Kameda, J.; Hamada, Y.; Kimura, G.

    2013-12-01

    In the 2011 Tohoku-oki earthquake, the seismic fault slip propagated close to the axis of the Japan Trench and caused an extremely large tsunami (Ide et al., 2011). It is generally considered that ductile deformation of unconsolidated sediments is commonly prominent in the aseismic shallow parts of the subduction zone. Therefore, it is unknown how the seismic rupture reached the nearby trench axis. The plate-boundary megathrust of the Japan Trench is characterized by a prominent seismic reflector, suggesting that the megathrust may host highly pressurized fluids (Kimura et al., 2012). Based on the result of Deep Sea Drilling Project (DSDP) Leg 56 at site 436 (reference, 1977), it is expected that the subducting sediments at the Japan Trench mainly consist of vitric diatomaceous and radiolarian ooze with pelagic clay intervals. Opal-A in the pelagic sediments transforms into quartz, and smectite transforms into illite. Kinetic modeling demonstrated that these reactions will progress with active dehydration at 50-60 km horizontally away from the deformation front and with a temperature of 100-120°C. This region coincides with the plate-boundary marked by a prominent seismic reflector, and suggests that the main source of highly pressured fluids is the dehydration of pelagic sediments (Kimura et al., 2012). However, detailed dehydration processes are still unclear mainly due to lack of quantitative sediment composition data. Therefore, in this study, we examined whole rock composition including amorphous silica of the core samples recovered at site 436 as well as those from the Japan Trench by the IODP 343 Japan Trench Fast Drilling Project (JFAST). Analysis of amorphous silica at site 436 documents that dehydration of the sediments is able to contribute to excess pressure at the shallow part of the megathrust if they underthrust as the same composition. At the drilling site of JFAST, a plate-boundary shear zone was identified around 820 mbsf, which was supposed to

  16. Dehydration of incoming sediments at the Japan Trench

    NASA Astrophysics Data System (ADS)

    Shimizu, M.; Kameda, J.; Hamada, Y.; Tanikawa, W.; Kimura, G.

    2014-12-01

    In the 2011 Tohoku-oki earthquake, the seismic fault slip propagated to the trench axis and caused an extremely large tsunami (Ide et al., 2011). Ductile deformation of unconsolidated sediments is commonly prominent in the aseismic shallow parts of the subduction zone. It is unknown how the seismic rupture reached the nearby trench axis. Based on the result of Deep Sea Drilling Project (DSDP) Leg 56 at site 436 (reference, 1977), it is expected that the subducting sediments at the Japan Trench mainly consist of vitric diatomaceous and radiolarian ooze with pelagic clay intervals. Opal and smectite in the pelagic sediments transform respectively into quartz and illite. Kinetic modeling demonstrated that these reactions will progress with active dehydration at 50-60 km horizontally away from the trench axis and with a temperature of 100-120°C. This region coincides with the plate-boundary marked by a prominent seismic reflector. It suggests that the main source of highly pressured fluids is the dehydration of pelagic sediments (Kimura et al., 2012). However, detailed dehydration processes are still unclear mainly due to lack of quantitative sediment composition data. Therefore, in this study, we examined whole rock composition including amorphous silica of the core samples recovered at site 436 as well as those from the Japan Trench by the IODP 343 Japan Trench Fast Drilling Project (JFAST). Analysis of amorphous silica at the drilling site of J-FAST documents that dehydration of the sediments is able to contribute to excess pressure at the shallow part of the megathrust if they underthrust as the same composition. At the drilling site of JFAST, a plate-boundary shear zone was identified around 820 mbsf (Chester et al., 2012). Our analysis showed that the shear zone is characterized by extremely high concentration of smectite (~70 wt%).These results suggest that the abundant smectite may have possibly fostered localized rupture and slip during the earthquake

  17. Observations of denitrification and dehydration in the winter polar stratospheres

    NASA Technical Reports Server (NTRS)

    Fahey, D. W.; Kelly, K. K.; Kawa, S. R.; Tuck, A. F.; Loewenstein, M.

    1990-01-01

    It is argued that denitrification of the Arctic stratosphere can be explained by the selective growth and sedimentation of aerosol particles rich in nitric acid. Because reactive nitrogen species moderate the destruction of ozone by chlorine-catalyzed reactions by sequestering chlorine in reservoir species such as ClONO2, the possibility of the removal of reactive nitrogen without dehydration should be allowed for in attempts to model ozone depletion in the Arctic. Indeed, denitrification along with elevated concentrations of reactive chlorine observed in 1989 indicate that the Arctic was chemically primed for ozone destruction without an extended period of temperatures below the frost point, as is characteristic of the Antarctic.

  18. Surgical management of left ventricular thrombus following severe dehydration.

    PubMed

    Tanaka, Yuki; Nie, Masaki; Yamamoto, Nobuyuki; Ohara, Kuniyoshi; Miyaji, Kagami

    2016-08-01

    We experienced a case involving a left ventricular ball-like thrombus caused by severe following a 150 mile cycling road race. The patient had lower-limb arterial obstruction due to systemic thromboembolism on admission with no significant embolism, including the cerebral arteries, were detected. Left ventricular wall motion was good with no evidence of left and right coronary artery occlusion; therefore, we performed emergency left ventricular thrombectomy. Although there are many reports of left ventricular thrombus following acute myocardial infarction, dehydration is a very rare cause. Herein, we describe the surgical and management approaches to the treatment of left ventricular thrombectomy in this case. PMID:26266631

  19. Dehydration and Performance on Clinical Concussion Measures in Collegiate Wrestlers

    PubMed Central

    Weber, Amanda Friedline; Mihalik, Jason P.; Register-Mihalik, Johna K.; Mays, Sally; Prentice, William E.; Guskiewicz, Kevin M.

    2013-01-01

    Context: The effects of dehydration induced by wrestling-related weight-cutting tactics on clinical concussion outcomes, such as neurocognitive function, balance performance, and symptoms, have not been adequately studied. Objective: To evaluate the effects of dehydration on the outcome of clinical concussion measures in National Collegiate Athletic Association Division I collegiate wrestlers. Design: Repeated-measures design. Setting: Clinical research laboratory. Patients or Other Participants: Thirty-two Division I healthy collegiate male wrestlers (age = 20.0 ± 1.4 years; height = 175.0 ± 7.5 cm; baseline mass = 79.2 ± 12.6 kg). Intervention(s): Participants completed preseason concussion baseline testing in early September. Weight and urine samples were also collected at this time. All participants reported to prewrestling practice and postwrestling practice for the same test battery and protocol in mid-October. They had begun practicing weight-cutting tactics a day before prepractice and postpractice testing. Differences between these measures permitted us to evaluate how dehydration and weight-cutting tactics affected concussion measures. Main Outcome Measures: Sport Concussion Assessment Tool 2 (SCAT2), Balance Error Scoring System, Graded Symptom Checklist, and Simple Reaction Time scores. The Simple Reaction Time was measured using the Automated Neuropsychological Assessment Metrics. Results: The SCAT2 measurements were lower at prepractice (P = .002) and postpractice (P < .001) when compared with baseline. The BESS error scores were higher at postpractice when compared with baseline (P = .015). The GSC severity scores were higher at prepractice (P = .011) and postpractice (P < .001) than at baseline and at postpractice when than at prepractice (P = .003). The number of Graded Symptom Checklist symptoms reported was also higher at prepractice (P = .036) and postpractice (P < .001) when compared with baseline, and at postpractice when compared with

  20. A rapid dehydration leaf assay reveals stomatal response differences in grapevine genotypes

    PubMed Central

    Hopper, Daniel W; Ghan, Ryan; Cramer, Grant R

    2014-01-01

    A simple and reliable way of phenotyping plant responses to dehydration was developed. Fully-developed leaves were detached and placed in a closed plastic box containing a salt solution to control the atmospheric water potential in the container. Three hours of dehydration (weight loss of the leaf) was optimal for measuring changes in stomatal response to dehydration. Application of the plant hormone abscisic acid (ABA) prior to leaf detachment decreased the amount of water loss, indicating that the assay was able to detect differences based on a stomatal response to dehydration. Five different Vitis genotypes (V. riparia, V. champinii, V. vinifera cv. Shiraz, V. vinifera cv. Grenache and V. vinifera cv. Cabernet Sauvignon) with known differences in drought tolerance were screened for their dehydration response and the results obtained corresponded to previous reports of stomatal responses in the vineyard. Significant differences in stomatal density along with differences in the amount and rate of water lost indicate differences in dehydration sensitivity among the genotypes screened. Differences in stomatal response to ABA were also detected. Shiraz had the lowest stomatal density and the highest ABA sensitivity among the genotypes screened, yet Shiraz lost the most amount of water, indicating that it was the least sensitive to dehydration. Despite having the highest stomatal density and intermediate stomatal sensitivity to ABA, V. riparia lost the smallest amount of water, indicating that it was the most sensitive to dehydration. The assay presented here represents a simple and reliable phenotyping method for plant responses to leaf dehydration. PMID:26504528

  1. Twin formation in hematite during dehydration of goethite

    NASA Astrophysics Data System (ADS)

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

    2016-07-01

    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.

  2. Enzyme dehydration using Microglassification™ preserves the protein's structure and function.

    PubMed

    Aniket; Gaul, David A; Bitterfield, Deborah L; Su, Jonathan T; Li, Victoria M; Singh, Ishita; Morton, Jackson; Needham, David

    2015-02-01

    Controlled enzyme dehydration using a new processing technique of Microglassification™ has been investigated. Aqueous solution microdroplets of lysozyme, α-chymotrypsin, catalase, and horseradish peroxidase were dehydrated in n-pentanol, n-octanol, n-decanol, triacetin, or butyl lactate, and changes in their structure and function were analyzed upon rehydration. Water solubility and microdroplet dissolution rate in each solvent decreased in the order: butyl lactate > n-pentanol > triacetin > n-octanol > n-decanol. Enzymes Microglassified™ in n-pentanol retained higher activity (93%-98%) than n-octanol (78%-85%) or n-decanol (75%-89%), whereas those Microglassified™ in triacetin (36%-75%) and butyl lactate (48%-79%) retained markedly lower activity. FTIR spectroscopy analyses showed α-helix to β-sheet transformation for all enzymes upon Microglassification™, reflecting a loss of bound water in the dried state; however, the enzymes reverted to native-like conformation upon rehydration. Accelerated stressed-storage tests using Microglassified™ lysozyme showed a significant (p < 0.01) decrease in enzymatic activity from 46,560 ± 2736 to 31,060 ± 4327 units/mg after 3 months of incubation; however, it was comparable to the activity of the lyophilized formulation throughout the test period. These results establish Microglassification™ as a viable technique for enzyme preservation without affecting its structure or function. PMID:25557848

  3. Osmotic dehydration of fruits and vegetables: a review.

    PubMed

    Yadav, Ashok Kumar; Singh, Satya Vir

    2014-09-01

    The main cause of perishability of fruits and vegetables are their high water content. To increase the shelf life of these fruits and vegetables many methods or combination of methods had been tried. Osmotic dehydration is one of the best and suitable method to increase the shelf life of fruits and vegetables. This process is preferred over others due to their vitamin and minerals, color, flavor and taste retention property. In this review different methods, treatments, optimization and effects of osmotic dehydration have been reviewed. Studied showed that combination of different osmotic agents were more effective than sucrose alone due to combination of properties of solutes. During the experiments it was found that optimum osmosis was found at approximately 40 °C, 40 °B of osmotic agent and in near about 132 min. Pretreatments also leads to increase the osmotic process in fruits and vegetables. Mass transfer kinetics study is an important parameter to study osmosis. Solids diffusivity were found in wide range (5.09-32.77 kl/mol) studied by Fick's laws of diffusion. These values vary depending upon types of fruits and vegetables and osmotic agents. PMID:25190823

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

    PubMed

    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. PMID:27041515

  5. Creatine Use and Exercise Heat Tolerance in Dehydrated Men

    PubMed Central

    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. Objective: To assess whether 1 week of CrM supplementation would compromise hydration status, alter thermoregulation, or increase the incidence of symptoms of heat illness in dehydrated men performing prolonged exercise in the heat. Design: Double-blind, randomized, crossover design. Setting: Human Performance Laboratory. Patients or Other Participants: Twelve active males, age = 22 ± 1 year, height = 180 ± 3 cm, mass = 78.8 ± 1.2 kg, body fat = 9 ± 1%, V̇o2peak = 50.9 ± 1 ml·kg−1·min−1. Intervention(s): Subjects consumed 21.6 g·d−1 of CrM or placebo for 7 days, underwent 48 ± 10 days of washout between treatments, and then crossed over to the alternate treatment in the creatine group. On day 7 of each treatment, subjects lost 2% body mass by exercising in 33.5°C and then completed an 80-minute exercise heat-tolerance test (33.5°C ± 0.5°C, relative humidity = 41 ± 12%). The test consisted of four 20-minute sequences of 4 minutes of rest, alternating a 3-minute walk and 1-minute high-intensity run 3 times, and walking for 4 minutes. Main Outcome Measures: Thermoregulatory, cardiorespiratory, metabolic, urinary, and perceptual responses. Results: On day 7, body mass had increased 0.88 kg. No interaction or treatment differences for placebo versus CrM during the exercise heat-tolerance test were noted in thermoregulatory (rectal temperature, 39.3 ± 0.4°C versus 39.4 ± 0.4°C) cardiorespiratory (V̇o2, 21.4 ± 2.7 versus 20.0 ± 1.8 ml·kg−1·min−1; heart rate, 192 ± 10 versus 192 ± 11 beats·min−1; mean arterial pressure, 90 ± 9 versus 88 ± 5 mm Hg), metabolic (lactate, 6.7 ± 2.7 versus 7.0

  6. The Usefulness of Clinical and Laboratory Parameters for Predicting Severity of Dehydration in Children with Acute Gastroenteritis

    PubMed Central

    Hoxha, Teuta Faik; Azemi, Mehmedali; Avdiu, Muharrem; Ismaili-jaha, Vlora; Grajqevci, Violeta; Petrela, Ela

    2014-01-01

    ABSTRACT Background: An accurate assessment of the degree of dehydration in infants and children is important for proper decision-making and treatment. This emphasizes the need for laboratory tests to improve the accuracy of clinical assessment of dehydration. The aim of this study was to assess the relationship between clinical and laboratory parameters in the assessment of dehydration. Methods: We evaluated prospectively 200 children aged 1 month to 5 years who presented with diarrhea, vomiting or both. Dehydration assessment was done following a known clinical scheme. Results: We enrolled in the study 200 children (57.5% were male). The mean age was 15.62±9.03 months, with more than half those studied being under 24 months old. Overall, 46.5% (93) had mild dehydration, 34% (68) had moderate dehydration, 5.5% (11) had severe dehydration whereas, 14% (28) had no dehydration. Patients historical clinical variables in all dehydration groups did not differ significantly regarding age, sex, fever, frequency of vomiting, duration of diarrhea and vomiting, while there was a trend toward severe dehydration in children with more frequent diarrhea (p=0.004). Serum urea and creatinine cannot discriminate between mild and moderate dehydration but they showed a good specificity for severe dehydration of 99% and 100% respectively. Serum bicarbonates and base excess decreased significantly with a degree of dehydration and can discriminate between all dehydration groups (P<0.001). Conclusion: Blood gases were useful to diagnose the degree of dehydration status among children presenting with acute gastroenteritis. Serum urea and creatinine were the most specific tests for severe dehydration diagnosis. Historical clinical patterns apart from frequency of diarrhea did not correlate with dehydration status. Further studies are needed to validate our results. PMID:25568559

  7. 76 FR 4284 - Grant of Authority for Subzone Status; Tulkoff Food Products, Inc. (Dehydrated Garlic), Baltimore...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-25

    ... given in the Federal Register (74 FR 40567, 8-12-2009) and the application has been processed pursuant... Foreign-Trade Zones Board Grant of Authority for Subzone Status; Tulkoff Food Products, Inc. (Dehydrated... following conditions: 1. All foreign-origin dehydrated garlic admitted to the subzone in foreign status...

  8. Quality of frozen fruit bars manufactured through infrared pre-dehydration

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this study, frozen restructured whole apple and strawberry bars were manufactured by partial dehydration, using infrared (IR) heating, followed by restructuring and freezing. The objective of this investigation was to determine the effect of IR partial dehydration on the quality of restructured f...

  9. 21 CFR 573.400 - Ethoxyquin in certain dehydrated forage crops.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... vegetable oils are to be used in the oil mix. (f) The label of any dehydrated forage crops treated with the... and vitamin E in the forage crops. (c) It is added to the dehydrated forage crops in an oil mixture containing only suitable animal or suitable vegetable oil, prior to grinding and mixing. (d) The...

  10. 21 CFR 573.400 - Ethoxyquin in certain dehydrated forage crops.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... vegetable oils are to be used in the oil mix. (f) The label of any dehydrated forage crops treated with the... and vitamin E in the forage crops. (c) It is added to the dehydrated forage crops in an oil mixture containing only suitable animal or suitable vegetable oil, prior to grinding and mixing. (d) The...

  11. 21 CFR 573.400 - Ethoxyquin in certain dehydrated forage crops.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... vegetable oils are to be used in the oil mix. (f) The label of any dehydrated forage crops treated with the... and vitamin E in the forage crops. (c) It is added to the dehydrated forage crops in an oil mixture containing only suitable animal or suitable vegetable oil, prior to grinding and mixing. (d) The...

  12. HIGH PERMEABILITY MEMBRANES FOR THE DEHYDRATION OF LOW WATER CONTENT ETHANOL BY PERVAPORATION

    EPA Science Inventory

    Energy efficient dehydration of low water content ethanol is a challenge for the sustainable production of fuel-grade ethanol. Pervaporative membrane dehydration using a recently developed hydrophilic polymer membrane formulation consisting of a cross-linked mixture of poly(allyl...

  13. Investigation of structural changes of silica particles during dehydration and chemosorption

    SciTech Connect

    Ogenko, V.M.; Ivashechkin, V.G.; Chuiko, A.A.; Mironyuk, I.F.

    1986-05-01

    Investigations have been made of changes in the structures of ultradisperse pyrogenic silica particles by small-angle x-ray scattering during dehydration and chemosorption. It has been established that during dehydration there are abrupt changes in the geometrical dimensions of the particles, caused by breakdown of coordination complexes between surface silicon atoms and water molecules.

  14. Dehydration of 2-Methyl-1-Cyclohexanol: New Findings from a Popular Undergraduate Laboratory Experiment

    ERIC Educational Resources Information Center

    Friesen, J. Brent; Schretzman, Robert

    2011-01-01

    The mineral acid-catalyzed dehydration of 2-methyl-1-cyclohexanol has been a popular laboratory exercise in second-year organic chemistry for several decades. The dehydration experiment is often performed by organic chemistry students to illustrate Zaitsev's rule. However, sensitive analytical techniques reveal that the results do not entirely…

  15. Outcomes related to dehydration in the pediatric population.

    PubMed

    Scherb, Cindy A; Stevens, Marcia S; Busman, Carol

    2007-10-01

    The purpose of this pilot study was twofold: 1) to determine whether there was a statistically significant difference in nursing-sensitive patient outcome ratings from admission to discharge, and 2) to describe nursing interventions used to care for children admitted with a primary diagnosis of dehydration to a 272-bed Midwestern community hospital. Twenty-nine patient care records meeting study criteria were extracted from all pediatric admission records during the study period. The patient care records are part of a computerized clinical documentation system using the standardized nursing languages of the North American Nursing Diagnosis Association, the Nursing Interventions Classification, and the Nursing Outcomes Classification (NOC). A statistically significant improvement in outcome ratings from admission to discharge was demonstrated for seven of eight NOC outcomes. PMID:17889729

  16. Malnutrition and Dehydration in the Third World: Practical Treatment

    PubMed Central

    Cowtan, Edgar R.

    1985-01-01

    Malnutrition coupled with dehydration (usually secondary to diarrhea) is one of the major causes of morbidity and death in the Third World. The mortality rate is high, especially in children; four to five million die each year. However, diagnosis and treatment of these problems has improved in the past decade. In therapeutic feeding programs, which are designed for markedly malnourished children, oral rehydration solution is likely the most important medicine that can be offered. After initial rehydration, the malnutrition can be treated with six to nine meals daily, and/or nasal-gastric feeding and special high energy milk formulas. Patients usually require four to six weeks before moving to a supplementary program, which supplies an additional 350-500 kilocalories and an extra 15 g of protein to the daily diet. This program is for those at high risk: children under age five, pregnant and lactating women, and certain debilitated patients. ImagesFig. 1 PMID:21274127

  17. Characterization of dehydration-induced luminescence of kaolinite

    NASA Technical Reports Server (NTRS)

    Lahav, N.; Coyne, L.; Lawless, J. G.

    1985-01-01

    The dehydration-induced luminescence of a colloidal kaolinite is investigated experimentally, with particular attention given to the effect of various treatments on the luminescence characteristics. It is found that the total photon count of the emitted light is linearly related to the film thickness up to a thickness of 30 microns; mechanical stress in the form of grinding increases the photon output and produces extensive changes in the emission kinetics. A direct check of the emission wavelength dependence (by using color filters) indicates that roughly 75 percent of the emission occurs in the wavelength range below 410 nm. It is also found that incorporation of fluorescent molecules into the kaolinite paste increases the photon output and may indicate the transfer of ultraviolet photons to the fluorescent probe.

  18. Benefits of tankage dehydration in the refinery process

    SciTech Connect

    Stewart, S.M. )

    1989-01-01

    The goal of every refinery is to produce marketable products to achieve profit objectives. In order to accomplish this goal contaminants or impurities found in hydrocarbon feedstocks must be removed prior to refinement. Efficient removal can produce finished products that meet quality specifications. The author discusses how crude oil desalting satisfies this requirement as the first step toward contaminant removal in the refining process. The purpose of desalting is to reduce the salt and water content of crude oil to the lowest level that is economically practical. The desalting process can be further enhanced by pre-treating crude in tankage to remove brine before the crude is desalted. Tankage dehydration is presented as a simple treatment process designed to reduce the brine content of crude feedstocks in storage.

  19. Dehydration of oil waste emulsions by means of flocculants

    SciTech Connect

    Gandurina, L.V.; Butseva, L.N.; Shtondina, V.S.

    1995-05-01

    Oil waste emulsions are formed in the course of pumping petroleum crudes and products and are collected from the surfaces of equipment in recirculating water systems and wastewater disposal facilities (oil separators, sand traps, oil traps, holding pits for accidental spills, settlers, ponds, sludge accumulators, and so on). Emulsions are also obtained in the course of cleaning equipment in crude oil desalting and dehydration units. Such emulsions are stable, structurized systems that are very resistant to dewatering by heating and settling in separator tanks. In order to break stabilized emulsions, i.e., in order to ensure complete coalescence of drops when they collide, it is not sufficient to increase the forces of mutual attraction of drops at the moment of collision; in addition, the protective shell must be either destroyed or weakened. Demulsifying agents, or surfactants, will displace the stabilizers. This report is concerned with demulsifier efficiency.

  20. A generic protocol for protein crystal dehydration using the HC1b humidity controller

    PubMed Central

    Lobley, Carina M. C.; Sandy, James; Sanchez-Weatherby, Juan; Mazzorana, Marco; Krojer, Tobias; Nowak, Radosław P.; Sorensen, Thomas L.

    2016-01-01

    Dehydration may change the crystal lattice and affect the mosaicity, resolution and quality of X-ray diffraction data. A dehydrating environment can be generated around a crystal in several ways with various degrees of precision and complexity. This study uses a high-precision crystal humidifier/dehumidifier to provide an airstream of known relative humidity in which the crystals are mounted: a precise yet hassle-free approach to altering crystal hydration. A protocol is introduced to assess the impact of crystal dehydration systematically applied to nine experimental crystal systems. In one case, that of glucose isomerase, dehydration triggering a change of space group from I222 to P21212 was observed. This observation is supported by an extended study of the behaviour of the glucose isomerase crystal structure during crystal dehydration. PMID:27139626

  1. A generic protocol for protein crystal dehydration using the HC1b humidity controller.

    PubMed

    Lobley, Carina M C; Sandy, James; Sanchez-Weatherby, Juan; Mazzorana, Marco; Krojer, Tobias; Nowak, Radosław P; Sorensen, Thomas L

    2016-05-01

    Dehydration may change the crystal lattice and affect the mosaicity, resolution and quality of X-ray diffraction data. A dehydrating environment can be generated around a crystal in several ways with various degrees of precision and complexity. This study uses a high-precision crystal humidifier/dehumidifier to provide an airstream of known relative humidity in which the crystals are mounted: a precise yet hassle-free approach to altering crystal hydration. A protocol is introduced to assess the impact of crystal dehydration systematically applied to nine experimental crystal systems. In one case, that of glucose isomerase, dehydration triggering a change of space group from I222 to P21212 was observed. This observation is supported by an extended study of the behaviour of the glucose isomerase crystal structure during crystal dehydration. PMID:27139626

  2. ROLE OF PRESSURE IN SMECTITE DEHYDRATION - EFFECTS ON GEOPRESSURE AND SMECTITE-TO-ILLITE TRANSFORMATION.

    USGS Publications Warehouse

    Colten-Bradley, Virginia, A.

    1987-01-01

    Evaluation of the effects of pressure on the temperature of interlayer water loss (dehydration) by smectites under diagenetic conditions indicates that smectites are stable as hydrated phases in the deep subsurface. Hydraulic and differential pressure conditions affect dehydration differently. The temperature of dehydration increase with pore fluid pressure and interlayer water density. The temperatures of dehydration increase with pore fluid pressure and interlayer water density. The temperatures of dehydration under differential-presssure conditions are inversely related to pressure and interlayer water density. The model presented assumes the effects of pore fluid composition and 2:1 layer reactivity to be negligible. Agreement between theoretical and experimental results validate this assumption. Additional aspects of the subject are discussed.

  3. [Learning to prevent dehydration in distant Mexican communities and markets].

    PubMed

    Alvarez Larrauri, S; Alvarez Larrauri, C; Jufresa Carreras, J

    1994-06-01

    Child mortality due to diarrheal diseases is high in Mexico. Official records reported 14,000 children died in 1990 of this cause. Yet, we do not know the real extent of the problem since unregistered child deaths in our countryside seem to be far more frequent than acknowledged by government information. Most of these deaths occur among poor peasants and indigenous people living far from medical services. There are more than 100,000 communities with less than 500 inhabitants. This population does not benefit from medical services due to several problems, such as accessibility and linguistic and cultural gaps. In order to promote Oral Rehydration Therapy (ORT) within these communities, the authors implemented an education strategy, aimed at this specific population, to enhance their learning of prevention of diarrhea and dehydration, and thereby to increase their use of ORT. While rendering account of research devised to prove the extensibility to larger scales of methods formerly tried at an experimental (pilot) level, this paper further discusses and reinforces the contribution of the insights of a critical sociology epistemological framework in planning and conducting sociological interventions in the field of health as well as in any other field. The basic assumption of this point of view is that to adopt rationalized solutions to their problems (e.g. the prevention of dehydration of their children by means of the ORT) people should have the opportunity to deliberate rationally about them in order to be able to justify or validate their actions regarding the course of events and the opinions and norms of their closest community.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8036530

  4. Advancing microwave technology for dehydration processing of biologics.

    PubMed

    Cellemme, Stephanie L; Van Vorst, Matthew; Paramore, Elisha; Elliott, Gloria D

    2013-10-01

    Our prior work has shown that microwave processing can be effective as a method for dehydrating cell-based suspensions in preparation for anhydrous storage, yielding homogenous samples with predictable and reproducible drying times. In the current work an optimized microwave-based drying process was developed that expands upon this previous proof-of-concept. Utilization of a commercial microwave (CEM SAM 255, Matthews, NC) enabled continuous drying at variable low power settings. A new turntable was manufactured from Ultra High Molecular Weight Polyethylene (UHMW-PE; Grainger, Lake Forest, IL) to provide for drying of up to 12 samples at a time. The new process enabled rapid and simultaneous drying of multiple samples in containment devices suitable for long-term storage and aseptic rehydration of the sample. To determine sample repeatability and consistency of drying within the microwave cavity, a concentration series of aqueous trehalose solutions were dried for specific intervals and water content assessed using Karl Fischer Titration at the end of each processing period. Samples were dried on Whatman S-14 conjugate release filters (Whatman, Maidestone, UK), a glass fiber membrane used currently in clinical laboratories. The filters were cut to size for use in a 13 mm Swinnex(®) syringe filter holder (Millipore(™), Billerica, MA). Samples of 40 μL volume could be dehydrated to the equilibrium moisture content by continuous processing at 20% with excellent sample-to-sample repeatability. The microwave-assisted procedure enabled high throughput, repeatable drying of multiple samples, in a manner easily adaptable for drying a wide array of biological samples. Depending on the tolerance for sample heating, the drying time can be altered by changing the power level of the microwave unit. PMID:24835259

  5. Spring dehydration in the Antarctic stratospheric vortex observed by HALOE

    NASA Technical Reports Server (NTRS)

    Pierce, R. Bradley; Grose, William L.; Russell, James M., III; Tuck, Adrian F.; Swinbank, Richard; O'Neill, Alan

    1994-01-01

    The distribution of dehydrated air in the middle and lower stratosphere during the 1992 Southern Hemisphere spring is investigated using Halogen Occultation Experiment (HALOE) observations and trajectory techniques. Comparisons between previously published Version 9 and the improved Version 16 retrievals on the 700-K isentropic surface show very slight (0.05 ppmv) increases in Version 16 CH4 relative to Version 9 within the polar vortex. Version 16 H2O mixing ratios show a reduction of 0.5 ppmv relative to Version 9 within the polar night jet and a reduction of nearly 1.0 ppmv in middle latitudes when compared to Version 9. The version 16 HALOE retrievals show low mixing ratios of total hydrogen (2CH4 + H2O) within the polar vortex on both 700 and 425 K isentropic surfaces relative to typical middle-stratospheric 2CH4 + H2O mixing ratios. The low 2CH4 + H2O mixing ratios are associated with dehydration. Slight reductions in total hydrogen, relative to typical middle-stratospheric values, are found at these levels throughout the Southern Hemisphere during this period. Trajectory calculations show that middle-latitude air masses are composed of a mixture of air from within the polar night jet and air from middle latitudes. A strong kinematic barrier to large-scale exchange is found on the poleward flank of the polar night jet at 700 K. A much weaker kinematic barrier is found at 425 K. The impact of the finite tangent pathlength of the HALOE measurements is investigated using an idealized tracer distribution. This experiment suggests that HALOE should be able to resolve the kinematic barrier, if it exists.

  6. Dehydration of isobutanol to isobutene in a slurry reactor

    SciTech Connect

    Latshaw, B.E.

    1994-02-01

    The April 1990 Alternative Fuels Proposal to the Department of Energy involved the development of new technology, based on the liquid phase process, for conversion of coal-derived synthesis gas to oxygenated hydrocarbon fuels, fuel additives, and fuel intermediates. The objective of this work was to develop a slurry reactor based process for the dehydration of isobutanol to isobutene. The isobutene can serve as a feedstock for the high octane oxygenated fuel additive methyl tertiary-butyl either (MTBE). Alumina catalysts were investigated because of their wide use as a dehydration catalyst. Four commercially available alumina catalysts (Catapal B, Versal B, Versal GH, and Al-3996R) were evaluated for both activity and selectivity to the branched olefin. All four catalysts demonstrated conversions greater than 80% at 290 C, while conversions of near 100% could be obtained at 330 C. The reaction favors low pressures and moderate to low space velocities. A yield of 0.90 mole isobutene per mole reacted isobutanol or better was obtained at conversions of 60--70% and higher. From 75 to 98% conversion, the four catalysts all provide isobutene yields ranging from 0.92 to 0.94 with the maximum occurring around 90% conversion. At low conversions, the concentration of diisobutyl ether becomes significant while the concentration of linear butenes is essentially a linear function of isobutanol conversion. Doping the catalyst with up to 0.8 wt % potassium showed a modest increase in isobutene selectivity; however, this increase was more than offset by a reduction in activity. Investigations using a mixed alcohols feed (consistent with isobutanol synthesis from syngas) demonstrated a small increase in the C4 iso-olefin selectivity over that observed for a pure isobutanol feed. 55 refs.

  7. Dehydration markedly impairs cardiovascular function in hyperthermic endurance athletes during exercise.

    PubMed

    González-Alonso, J; Mora-Rodríguez, R; Below, P R; Coyle, E F

    1997-04-01

    We identified the cardiovascular stress encountered by superimposing dehydration on hyperthermia during exercise in the heat and the mechanisms contributing to the dehydration-mediated stroke volume (SV) reduction. Fifteen endurance-trained cyclists [maximal O2 consumption (VO2max) = 4.5 l/min] exercised in the heat for 100-120 min and either became dehydrated by 4% body weight or remained euhydrated by drinking fluids. Measurements were made after they continued exercise at 71% VO2max for 30 min while 1) euhydrated with an esophageal temperature (T(es)) of 38.1-38.3 degrees C (control); 2) euhydrated and hyperthermic (39.3 degrees C); 3) dehydrated and hyperthermic with skin temperature (T(sk)) of 34 degrees C; 4) dehydrated with T(es) of 38.1 degrees C and T(sk) of 21 degrees C; and 5) condition 4 followed by restored blood volume. Compared with control, hyperthermia (1 degrees C T(es) increase) and dehydration (4% body weight loss) each separately lowered SV 7-8% (11 +/- 3 ml/beat; P < 0.05) and increased heart rate sufficiently to prevent significant declines in cardiac output. However, when dehydration was superimposed on hyperthermia, the reductions in SV were significantly (P < 0.05) greater (26 +/- 3 ml/beat), and cardiac output declined 13% (2.8 +/- 0.3 l/min). Furthermore, mean arterial pressure declined 5 +/- 2%, and systemic vascular resistance increased 10 +/- 3% (both P < 0.05). When hyperthermia was prevented, all of the decline in SV with dehydration was due to reduced blood volume (approximately 200 ml). These results demonstrate that the superimposition of dehydration on hyperthermia during exercise in the heat causes an inability to maintain cardiac output and blood pressure that makes the dehydrated athlete less able to cope with hyperthermia. PMID:9104860

  8. Ozone fumigation for safety and quality of wine grapes in postharvest dehydration.

    PubMed

    Botondi, Rinaldo; De Sanctis, Federica; Moscatelli, Niccolò; Vettraino, Anna Maria; Catelli, Cesare; Mencarelli, Fabio

    2015-12-01

    This paper proposes postharvest ozone fumigation (as a method) to control microorganisms and evaluate the effect on polyphenols, anthocyanins, carotenoids and cell wall enzymes during the grape dehydration for wine production. Pignola grapes were ozone-treated (1.5 g/h) for 18 h (A=shock treatment), then dehydrated or ozone-treated (1.5 g/h) for 18 h and at 0.5 g/h for 4 h each day (B=long-term treatment) during dehydration. Treatment and dehydration were performed at 10 °C. No significant difference was found for total carotenoid, total phenolic and total anthocyanin contents after 18 h of O3 treatment. A significant decrease in phenolic and anthocyanin contents occurred during treatment B. Also carotenoids were affected by B ozone treatment. Pectin methylesterase (PME) and polygalacturonase (PG) activities were higher in A-treated grapes during dehydration. Finally, ozone reduced fungi and yeasts by 50%. Shock ozone fumigation (A treatment) before dehydration can be used to reduce the microbial count during dehydration without affecting polyphenol and carotenoid contents. PMID:26041242

  9. Wet fractionation of forage to reduce energy requirements of dehydration. Final technical report

    SciTech Connect

    Not Available

    1981-01-01

    The Valley Dehydrating Company of Atwood, Colorado, was founded in 1952 to dehydrate alfalfa. Subsequently, it was realized that the rapidly escalating cost of natural gas, burned to provide heat for the dehydration of the alfalfa, would make the traditional process of direct dehydration uneconomical. As an alternative, the use of green crop fractionation in combination with waste heat recovery from the main dryer was investigated. In the wet, or green crop fractionation process, freshly cut alfalfa is brought to the processing site where it is first macerated to rupture the plant cells and then is pressed to remove as much juice as possible. The fiber fraction from the pressing contains only about half as much moisture as the original alfalfa; and thus, can be dehydrated at a much lower cost. The juice which contains plant proteins and lipids as well as a variety of soluble components, is heated to above 80/sup 0/C in order to coagulate the protein. When this material is separated from the residual liquid and dried a high protein, high xanthophyll product (Pro-Xan) results. The remaining solubles are concentrated, using the waste heat from the main dryer to yield a molasses-like product. Instead of the one product, (dehydrated alfalfa) produced by the traditional process, green crop fractionation produces three: dehydrated pressed alfalfa, leaf nutrient concentrate, and molasses.

  10. Effects of dehydration on the viscoelastic properties of vocal folds in large deformations.

    PubMed

    Miri, Amir K; Barthelat, François; Mongeau, Luc

    2012-11-01

    Dehydration may alter vocal fold viscoelastic properties, thereby hampering phonation. The effects of water loss induced by an osmotic pressure potential on vocal fold tissue viscoelastic properties were investigated. Porcine vocal folds were dehydrated by immersion in a hypertonic solution, and quasi-static and low-frequency dynamic traction tests were performed for elongations of up to 50%. Digital image correlation was used to determine local strains from surface deformations. The elastic modulus and the loss factor were then determined for normal and dehydrated tissues. An eight-chain hyperelastic model was used to describe the observed nonlinear stress-stretch behavior. Contrary to the expectations, the mass history indicated that the tissue absorbed water during cyclic extension when submerged in a hypertonic solution. During loading history, the elastic modulus was increased for dehydrated tissues as a function of strain. The response of dehydrated tissues was much less affected when the load was released. This observation suggests that hydration should be considered in micromechanical models of the vocal folds. The internal hysteresis, which is often linked to phonation effort, increased significantly with water loss. The effects of dehydration on the viscoelastic properties of vocal fold tissue were quantified in a systematic way. A better understanding of the role of hydration on the mechanical properties of vocal fold tissue may help to establish objective dehydration and phonotrauma criteria. PMID:22483778

  11. Intra- and extracellular dehydration-induced thirst-related behavior in an amphibian.

    PubMed

    Taylor, K; Mayer, L P; Propper, C R

    The behavioral response to dehydration is critical to an animal's survival. Because of their permeable skin, amphibians are particularly sensitive to dehydrating conditions. We tested the hypothesis that different forms of dehydration induce water absorption response (WR) behavior in the desert spadefoot toad, Scaphiopus couchii. First, we determined the behavioral response to intracellular dehydration by treating fully hydrated toads with increasing concentrations of hypertonic solutions of NaCl or sucrose via intraperitoneal injection (i.p.). Animals that were treated to induce intracellular dehydration with either solute exhibited a significant increase in WR behavior compared to vehicle-treated controls. To distinguish that the response was a result of an increased osmotic gradient between the intra- and extracellular compartments, we treated fully hydrated animals i.p. with urea, which freely passes into the intracellular compartment and increases overall animal osmolarity. Urea treatment did not induce WR behavior. To determine the response to extracellular dehydration, the blood volume of fully hydrated toads was reduced via cardiac puncture, and the WR behavior was measured. Animals who had a reduction in blood volume exhibited a significant increase in WR behavior compared to sham-punctured controls. Our results are the first to demonstrate that multiple forms of dehydration can induce thirst-related behavior in amphibians. PMID:10073473

  12. Effects of Dehydration on the Viscoelastic Properties of Vocal Folds in Large Deformations

    PubMed Central

    Miri, Amir K.; Barthelat, François; Mongeau, Luc

    2012-01-01

    Summary Dehydration may alter vocal fold viscoelastic properties, which may hamper phonation. The effects of water loss induced by an osmotic-pressure potential on vocal fold tissue viscoelastic properties were investigated. Porcine vocal folds were dehydrated by immersion in a hypertonic solution, and quasi-static and low-frequency dynamic traction tests were performed for elongations of up to 50%. Digital image correlation was used to determine local strains from surface deformations. The elastic modulus and the loss factor were then determined for normal and dehydrated tissues. An eight-chain hyperelastic model was used to describe the observed nonlinear stress-stretch behavior. Contrary to expectations, the mass history indicated that the tissue absorbed water during cyclic extension when submerged in a hypertonic solution. During loading history, the elastic modulus was increased for dehydrated tissues as a function of strain. The response of dehydrated tissues was much less affected when the load was releasing. This calls more attention to the modeling of vocal folds in micromechanics modeling. The internal hysteresis, which is often linked to phonation effort, increased significantly with water loss. The effects of dehydration on the viscoelastic properties of vocal fold tissue were quantified in a systematic way. The results will contribute to a better understanding of the basic biomechanics of voice production and ultimately will help establish objective dehydration and phonotrauma criteria. PMID:22483778

  13. Bonding by Hydroxide-Catalyzed Hydration and Dehydration

    NASA Technical Reports Server (NTRS)

    Gwo, Dz-Hung

    2008-01-01

    A simple, inexpensive method for bonding solid objects exploits hydroxide-catalyzed hydration and dehydration to form silicate-like networks in thin surface and interfacial layers between the objects. The method can be practiced at room temperature or over a wide range of temperatures. The method was developed especially to enable the formation of precise, reliable bonds between precise optical components. The bonds thus formed exhibit the precision and transparency of bonds formed by the conventional optical-contact method and the strength and reliability of high-temperature frit bonds. The method also lends itself to numerous non-optical applications in which there are requirements for precise bonds and/or requirements for bonds, whether precise or imprecise, that can reliably withstand severe environmental conditions. Categories of such non-optical applications include forming composite materials, coating substrates, forming laminate structures, and preparing objects of defined geometry and composition. The method is applicable to materials that either (1) can form silicate-like networks in the sense that they have silicate-like molecular structures that are extensible into silicate-like networks or (2) can be chemically linked to silicate-like networks by means of hydroxide-catalyzed hydration and dehydration. When hydrated, a material of either type features surface hydroxyl (-OH) groups. In this method, a silicate-like network that bonds two substrates can be formed either by a bonding material alone or by the bonding material together with material from either or both of the substrates. Typically, an aqueous hydroxide bonding solution is dispensed and allowed to flow between the mating surfaces by capillary action. If the surface figures of the substrates do not match precisely, bonding could be improved by including a filling material in the bonding solution. Preferably, the filling material should include at least one ingredient that can be hydrated to

  14. Observational constraints on the efficiency of dehydration mechanisms in the tropical tropopause layer

    NASA Astrophysics Data System (ADS)

    Rollins, A. W.; Thornberry, T. D.; Gao, R. S.; Woods, S.; Lawson, R. P.; Bui, T. P.; Jensen, E. J.; Fahey, D. W.

    2016-03-01

    The efficiency of dehydration in the tropical tropopause layer (TTL) determines how closely water vapor will be reduced to the lowest saturation mixing ratio encountered along a trajectory to the stratosphere, thereby strongly influencing stratospheric humidity. The NASA Airborne Tropical Tropopause Experiment (ATTREX) provided an unprecedented number and quality of in situ observations to constrain the key mechanisms controlling this dehydration. Statistical analyses of the ATTREX data show that nucleation, growth, and sedimentation each result in TTL dehydration becoming increasingly inefficient at temperatures below 200 K. Because of these inefficiencies, models that ignore these mechanisms likely underestimate water vapor at the stratospheric entry point by ~10-20% at the lowest temperatures.

  15. Iron-Catalyzed Dehydration of Aldoximes to Nitriles Requiring Neither Other Reagents Nor Nitrile Media.

    PubMed

    Hyodo, Kengo; Kitagawa, Saki; Yamazaki, Masayuki; Uchida, Kingo

    2016-05-01

    The dehydration of aldoximes is an environmentally benign reaction affording the desired nitrile and water as a by-product. However, most of the reported catalytic dehydration reactions of aldoximes require a solvent containing nitrile to synthesize the corresponding nitrile compounds. Inspired by recent reports on the enzymatic synthesis under nitrile-free conditions, we here describe that a simple iron salt catalyzes the dehydration of aldoximes requiring neither other reagents nor nitrile media. Our method can be applied to the one-pot synthesis of nitiriles from aldehydes. PMID:26910510

  16. Molecular and structural preservation of dehydrated bio-tissue for THz spectroscopy

    NASA Astrophysics Data System (ADS)

    Png, Gretel M.; Choi, Jin Wook; Guest, Ian; Ng, Brian W.-H.; Mickan, Samuel P.; Abbott, Derek; Zhang, Xi-Cheng

    2007-12-01

    Terahertz transmission through freshly excised biological tissue is limited by the tissue's high water content. Tissue fixation methods that remove water, such as fixation in Formalin, destroy the structural information of proteins hence are not suitable for THz applications. Dehydration is one possible method for revealing the tissue's underlying molecular structure and components. In this study, we measured the THz responses over time of dehydrating fresh, necrotic and lyophilized rat tissue. Our results show that as expected, THz absorption increases dramatically with drying and tissue freshness can be maintained through lyophilization. Dehydrated biological tissue with retained molecular structure can be useful for future laser-based THz wave molecular analysis.

  17. On the dehydration mechanism of Mg(OH){sub 2} by a high-energy electron beam

    SciTech Connect

    Su Dong; Jiang, Nan; Spence, John C. H.; He Feng; Petuskey, William T.

    2008-09-15

    The dehydration process in Mg(OH){sub 2} induced by high-energy electron irradiation is studied by in situ electron energy loss spectroscopy. During dehydration, both the low energy-loss spectra and the Mg L{sub 23} edge show the existence of partially oxidized Mg- or O-deficient MgO in the dehydrated products, which is not seen in the thermally dehydrated MgO. This indicates that the dehydration mechanism under the electron beam may be different from the mechanism involved in a thermal process.

  18. Tropical Tropopause Layer Cloud Formation, Convection and Stratospheric Dehydration

    NASA Astrophysics Data System (ADS)

    Schoeberl, M. R.; Dessler, A. E.; Wang, T.; Avery, M. A.; Jensen, E. J.

    2014-12-01

    Using MERRA reanalysis winds, temperatures and anvil cloud ice, we use our domain-filling, forward trajectory model to study the impact that more realistic cloud formation and convective water injection has on stratospheric water vapor. Our model computed cloud fraction shows reasonable agreement with cloud frequency observed by HIRDLS and CALIOP in the tropical troposphere layer (TTL). Our results suggest that ~64% of the cirrus formed in the TTL are due convection. Overall we find that inclusion of cloud microphysical processes increases stratospheric water vapor by 0.5 ppmv. Adding anvil ice increases stratospheric water vapor by an additional 0.5-0.6 ppmv but has a bigger impact on cloud formation with an increase of ~20-30% in TTL cloud fraction. With convection and cloud dehydration global 18-30 km average water vapor is ~5-7% higher than MLS water vapor observations. Adding waves to the MERRA temperature fields reduces stratospheric water vapor bringing our estimates to within 3% of MLS.

  19. Ethanol Dehydration to Ethylene in a Stratified Autothermal Millisecond Reactor

    SciTech Connect

    Skinner, MJ; Michor, EL; Fan, W; Tsapatsis, M; Bhan, A; Schmidt, LD

    2011-08-10

    The concurrent decomposition and deoxygenation of ethanol was accomplished in a stratified reactor with 50-80 ms contact times. The stratified reactor comprised an upstream oxidation zone that contained Pt-coated Al(2)O(3) beads and a downstream dehydration zone consisting of H-ZSM-5 zeolite films deposited on Al(2)O(3) monoliths. Ethanol conversion, product selectivity, and reactor temperature profiles were measured for a range of fuel:oxygen ratios for two autothermal reactor configurations using two different sacrificial fuel mixtures: a parallel hydrogen-ethanol feed system and a series methane-ethanol feed system. Increasing the amount of oxygen relative to the fuel resulted in a monotonic increase in ethanol conversion in both reaction zones. The majority of the converted carbon was in the form of ethylene, where the ethanol carbon-carbon bonds stayed intact while the oxygen was removed. Over 90% yield of ethylene was achieved by using methane as a sacrificial fuel. These results demonstrate that noble metals can be successfully paired with zeolites to create a stratified autothermal reactor capable of removing oxygen from biomass model compounds in a compact, continuous flow system that can be configured to have multiple feed inputs, depending on process restrictions.

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

    PubMed Central

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

    2016-01-01

    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. PMID:27222748

  1. Dehydrating and Sterilizing Wastes Using Supercritical CO2

    NASA Technical Reports Server (NTRS)

    Brown, Ian J.

    2006-01-01

    A relatively low-temperature process for dehydrating and sterilizing biohazardous wastes in an enclosed life-support system exploits (1) the superior mass-transport properties of supercritical fluids in general and (2) the demonstrated sterilizing property of supercritical CO2 in particular. The wastes to be treated are placed in a chamber. Liquid CO2, drawn from storage at a pressure of 850 psi (approx.=5.9 MPa) and temperature of 0 C, is compressed to pressure of 2 kpsi (approx.=14 MPa) and made to flow into the chamber. The compression raises the temperature to 10 C. The chamber and its contents are then further heated to 40 C, putting the CO2 into a supercritical state, in which it kills microorganisms in the chamber. Carrying dissolved water, the CO2 leaves the chamber through a back-pressure regulator, through which it is expanded back to the storage pressure. The expanded CO2 is refrigerated to extract the dissolved water as ice, and is then returned to the storage tank at 0 C

  2. Chryseobacterium limigenitum sp. nov., isolated from dehydrated sludge.

    PubMed

    Kämpfer, Peter; Trček, Janja; Skok, Barbara; Šorgo, Andrej; Glaeser, Stefanie P

    2015-06-01

    An intense yellow pigmented strain (SUR2(T)) isolated from dehydrated activated sludge was studied in detail to clarify its taxonomic assignment. Cells of the isolate showed a rod-shaped morphology and stained Gram-negative. Comparative 16S rRNA gene sequence analysis revealed highest similarities to the type strains of Chryseobacterium polytrichastri YG4-6(T) (98.6 %), Chryseobacterium aahli T68F(T) (97.9 %), Chryseobacterium daeguense K105(T) and Chryseobacterium gregarium DSM 79109(T) (both 97.4 %). 16S rRNA gene-sequence similarities to all other Chryseobacterium species were below 97.3 %. The fatty acid analysis of strain SUR2(T) revealed a Chryseobacterium typical profile composed mainly of the fatty acids C15:0 iso, C15:0 iso 2-OH, C17:1 iso ω9c, and C17:0 iso 3-OH. DNA-DNA hybridizations with the type strains of C. polytrichastri, C. aahli, C. daeguense and C. gregarium resulted in values below 70 %. Differentiating biochemical and chemotaxonomic properties showed differences to the most closely related species and suggest that the isolate SUR2(T) represents a novel species, for which the name Chryseobacterium limigenitum sp. nov. (type strain SUR2(T) = ZIM B1019(T) = CCM 8594(T) = LMG 28734(T)) is proposed. PMID:25812970

  3. Evaluation of biohazards in dehydrated biofilms on foodstuff packaging.

    PubMed

    Le Magrex-Debar, E; Lemoine, J; Gellé, M P; Jacquelin, L F; Choisy, C

    2000-04-10

    Plastic materials used for food packaging are clean but not sterile when the food is just packaged. Accidental wet contamination may occur at every moment between packaging and opening by the consumer: on polyethylene (PET), bacteria may adhere strongly and constitute a biofilm in less than 24 h. By rolling on themselves, PET sheets may contaminate food. We tried to show that contact with salted foodstuffs favoured microbial recovery. Four strains were chosen to perform biofilms on PET: Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa and Escherichia coli. Biofilms were dried up 24 h. Biofilm bacteria were stressed by adhesion, by starvation and by dehydration. However, they were capable of recovery in salted solutions or media, probably because one (or more) stress protected them against another stress. Stress was demonstrated by stress protein production, by mean of electrophoresis, and membrane lesions by mean of flow cytometry. Stress recovery was performed in aqueous salted solutions or salted brain-heart infusion with NaCl 9, 15, 20 and 30 g/l. Staphylococci were more sensitive to these stresses and recovery was a function of salt concentration. Gram-negative bacteria were little affected by stresses; salt effects were less important. If all these biofilms were capable of recovery from stresses in salted media, flexible PET could possibly lead to a health hazard when it is used for wet salt meats, e.g. PMID:10791750

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

    PubMed

    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. PMID:27222748

  5. Ethanol dehydration to ethylene in a stratified autothermal millisecond reactor.

    PubMed

    Skinner, Michael J; Michor, Edward L; Fan, Wei; Tsapatsis, Michael; Bhan, Aditya; Schmidt, Lanny D

    2011-08-22

    The concurrent decomposition and deoxygenation of ethanol was accomplished in a stratified reactor with 50-80 ms contact times. The stratified reactor comprised an upstream oxidation zone that contained Pt-coated Al(2)O(3) beads and a downstream dehydration zone consisting of H-ZSM-5 zeolite films deposited on Al(2)O(3) monoliths. Ethanol conversion, product selectivity, and reactor temperature profiles were measured for a range of fuel:oxygen ratios for two autothermal reactor configurations using two different sacrificial fuel mixtures: a parallel hydrogen-ethanol feed system and a series methane-ethanol feed system. Increasing the amount of oxygen relative to the fuel resulted in a monotonic increase in ethanol conversion in both reaction zones. The majority of the converted carbon was in the form of ethylene, where the ethanol carbon-carbon bonds stayed intact while the oxygen was removed. Over 90% yield of ethylene was achieved by using methane as a sacrificial fuel. These results demonstrate that noble metals can be successfully paired with zeolites to create a stratified autothermal reactor capable of removing oxygen from biomass model compounds in a compact, continuous flow system that can be configured to have multiple feed inputs, depending on process restrictions. PMID:21834091

  6. Dehydration of ethanol by facile synthesized glucose-based silica.

    PubMed

    Tang, Baokun; Bi, Wentao; Row, Kyung Ho

    2013-02-01

    Bioethanol is considered a potential liquid fuel that can be produced from biomass by fermentation and distillation. Although most of the water is removed by distillation, the purity of ethanol is limited to 95-96 % due to the formation of a low-boiling point, water-ethanol azeotrope. To improve the use of ethanol as a fuel, many methods, such as dehydration, have been proposed to avoid distillation and improve the energy efficiency of extraction. Glucose-based silica, as an adsorbent, was prepared using a simple method, and was proposed for the adsorption of water from water-ethanol mixtures. After adsorption using 0.4 g of adsorbent for 3 h, the initial water concentration of 20 % (water, v/v) was decreased to 10 % (water, v/v). For water concentrations less than 5 % (water, v/v), the adsorbent could concentrate ethanol to 99 % (ethanol, v/v). The Langmuir isotherms used to describe the adsorption of water on an adsorbent showed a correlation coefficient of 0.94. The separation factor of the adsorbent also decreased with decreasing concentration of water in solution. PMID:23299980

  7. Basic Study on Sludge Concentration and Dehydration with Ultrasonic Exposure

    NASA Astrophysics Data System (ADS)

    Sawada, Yuta; Nagashima, Satoshi; Uchida, Takeyoshi; Kawashima, Norimichi; Takeuchi, Shinichi; Akita, Masashi; Nagaoka, Hiroshi

    2005-06-01

    We study the condensation of sludge and the improvement of the dehydration efficiency of sludge by acoustic cavitation for efficiency improvement and cost reduction in water treatment. An ultrasound wave was irradiated into activated sludge in the water tank of our ultrasound exposure system and a standing wave acoustic field was formed using a vibrating disk driven by a Langevin-type transducer. The vibrating disk was mounted on the bottom of the water tank. Acoustic cavitation was generated in the activated sludge suspension and the sludge was floated to the water surface by ultrasound exposure with this system. We observed B-mode ultrasound images of the activated sludge suspension before ultrasound exposure and that of the floated sludge and treated water after ultrasound exposure. The ultrasound diagnostic equipment was used for the observation of the B-mode ultrasound images of the sludge. It was found that the sludge floated to the water surface because of adhesion of microbubbles generated by acoustic cavitation to the sludge particles, which decreased the sludge density. It can be expected that the drifting sludge in water can be recovered by the flotation thickening method of sludge as an application of the results of this study. It is difficult to recover the drifting sludge in water by the conventional gravity thickening method.

  8. Freeze avoidance: a dehydrating moss gathers no ice.

    PubMed

    Lenné, Thomas; Bryant, Gary; Hocart, Charles H; Huang, Cheng X; Ball, Marilyn C

    2010-10-01

    Using cryo-SEM with EDX fundamental structural and mechanical properties of the moss Ceratodon purpureus (Hedw.) Brid. were studied in relation to tolerance of freezing temperatures. In contrast to more complex plants, no ice accumulated within the moss during the freezing event. External ice induced desiccation with the response being a function of cell type; water-filled hydroid cells cavitated and were embolized at -4 °C while parenchyma cells of the inner cortex exhibited cytorrhysis, decreasing to ∼ 20% of their original volume at a nadir temperature of -20 °C. Chlorophyll fluorescence showed that these winter acclimated mosses displayed no evidence of damage after thawing from -20 °C while GCMS showed that sugar concentrations were not sufficient to confer this level of freezing tolerance. In addition, differential scanning calorimetry showed internal ice nucleation occurred in hydrated moss at ∼-12 °C while desiccated moss showed no evidence of freezing with lowering of nadir temperature to -20 °C. Therefore the rapid dehydration of the moss provides an elegantly simple solution to the problem of freezing; remove that which freezes. PMID:20525002

  9. Protoplast dehydration correlated with heat resistance of bacterial spores.

    PubMed Central

    Nakashio, S; Gerhardt, P

    1985-01-01

    Water content of the protoplast in situ within the fully hydrated dormant bacterial spore was quantified by use of a spore in which the complex of coat and outer (pericortex) membrane was genetically defective or chemically removed, as evidenced by susceptibility of the cortex to lysozyme and by permeability of the periprotoplast integument to glucose. Water content was determined by equilibrium permeability measurement with 3H-labeled water (confirmed by gravimetric measurement) for the entire spore, with 14C-labeled glucose for the integument outside the inner (pericytoplasm) membrane, and by the difference for the protoplast. The method was applied to lysozyme-sensitive spores of Bacillus stearothermophilus, B. subtilis, B. cereus, B. thuringiensis, and B. megaterium (four types). Comparable lysozyme-resistant spores, in which the outer membrane functioned as the primary permeability barrier to glucose, were employed as controls. Heat resistances were expressed as D100 values. Protoplast water content of the lysozyme-sensitive spore types correlated with heat resistance exponentially in two distinct clusters, with the four B. megaterium types in one alignment, and with the four other species types in another. Protoplast water contents of the B. megaterium spore types were sufficiently low (26 to 29%, based on wet protoplast weight) to account almost entirely for their lesser heat resistance. Corresponding values of the other species types were similar or higher (30 to 55%), indicating that these spores depended on factors additional to protoplast dehydration for their much greater heat resistance. PMID:3988704

  10. Onion and garlic dehydration in the San Emidio Desert, Nevada

    SciTech Connect

    Lund, J.W.; Lienau, P.J.

    1994-07-01

    Integrated Ingredients dedicated their new onion and garlic processing plant on May 25th. {open_quotes}Grunion{close_quotes} as the new community of 72 employees has been labeled, is located just south of Empire and Gerlach and about 100 miles north of Reno, Nevada. The plant, run by Integrated Ingredients (based in Alameda, CA), is a division of Burns Philp Food, Inc., which owns brands such as Spice Islands, Durkee-French and Fleischmann`s. This plant gives the company the ability to produce its own products for industrial and consumer markets instead of purchasing them. The plant was located in the San Emidio Desert at the edge of the vast Black Rock Desert and the Great Basin to take advantage of the high temperature geothermal resource (approximately 270{degrees}F). The resource is also used by the OESI/AMOR II 3.6 MW binary plant about a mile south of the dehydration plant and a gold heap leaching operation just to the north of the plant (Wind Mt. mine operated by AMAX). In addition to the geothermal energy, the high desert is an ideal location for onion and garlic processing because the cold winters kill damaging microbes. Dry winters and summers also help.

  11. Flexible Asymmetric Encapsulation for Dehydration-Responsive Hybrid Microfibers.

    PubMed

    Chaurasia, Ankur S; Sajjadi, Shahriar

    2016-08-01

    A new class of smart alginate microfibers with asymmetric oil encapsulates is introduced. These fibers are produced by injecting an aqueous alginate solution into an outer aqueous calcium chloride solution to form alginate fibers, which are asymmetrically loaded with oil entities through eccentrically aligned inner capillaries. The fiber morphology and its degree of asymmetry can be tuned via altering the size, location, and frequency of the oil encapsulates. These asymmetric fibers reveal significant potential for applications where conventional symmetric fibers fail to perform. It is shown how asymmetric oil-encapsulated fibers can become dehydration-sensitive, and trigger the release of encapsulates if their hydration level drops below a critical value. It is also shown how the triggered response could be switched off on demand by stabilizing the oil encapsulates. The capability of asymmetric fibers to carry and release multiple cargos in parallel is demonstrated. The fibers loaded with equal-sized spheres are more asymmetric than those containing unequal drops, have a higher tensile strength, and show better potential for a triggered response. PMID:27352241

  12. Dehydration of Methanediol in Aqueous Solution: An ONIOM(QM/MM) Study.

    PubMed

    Inaba, Satoshi; Sameera, W M C

    2016-08-25

    We used ONIOM(QM/MM) method to examine the dehydration of a methanediol in aqueous solution. A methanediol and a small number of water molecules in the proximity of the methanediol are calculated with quantum mechanics (QM), while a number of water molecules far from the methanediol are calculated with molecular mechanics (MM). A molecular dynamical simulation shows that 12 water molecules are located within the hydration shell of a methanediol. The energy barrier for the dehydration of a methanediol decreases when we increase the number of water molecules in the QM region and converges toward a finite value when 12 water molecules are included in the QM region. This indicates a significant effect of water molecules within the hydration shell on the dehydration process of a methanediol in aqueous solution. The dehydration rate calculated with the ONIOM(QM/MM) method agrees well with that obtained from a laboratory experiment. PMID:27490867

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  14. Energy Efficient Hybrid Vapor Stripping-Vapor Permeation Process for Ethanol Recovery ad Dehydration

    EPA Science Inventory

    Distillation combined with molecular sieve dehydration is the current state of the art for fuel grade ethanol production from fermentation broths. To improve the sustainability of bioethanol production, energy efficient separation alternatives are needed, particularly for lower f...

  15. Energy efficient recovery and dehydration of ethanol from fermentation broths by Membrane Assisted Vapor Stripping technology

    EPA Science Inventory

    Distillation combined with molecular sieve dehydration is the current state of the art for fuel grade ethanol production from fermentation broths. To improve the sustainability of bioethanol production, energy efficient separation alternatives are needed, particularly for lower ...

  16. A NOVEL HYDROPHILIC POLYMER MEMBRANE FOR THE DEHYDRATION OF ORGANIC SOLVENTS

    EPA Science Inventory

    Novel hydrophilic polymer membranes based on polyallylamine ydrochloride- polyvinylalcohol are developed. The high selectivity and flux characteristics of these membranes for the dehydration of organic solvents are evaluated using pervaporation technology and are found to be ver...

  17. Dehydration and Denitrification in the Arctic Polar Vortex During the 1995-1996 Winter

    NASA Technical Reports Server (NTRS)

    Hintsa, E. J.; Newman, P. A.; Jonsson, H. H.; Webster, C. R.; May, R. D.; Herman, R. L.; Lait, L. R.; Schoeberl, M. R.; Elkins, J. W.; Wamsley, P. R.; Dutton, G. S.; Bui, T. P.; Kohn, D. W.; Anderson, J. G.

    1998-01-01

    Dehydration of more than 0.5 ppmv water was observed between 18 and 19 km (0-450-465 K) at the edge of the Arctic polar vortex on February 1, 1996. More than half the reactive nitrogen (NO(y)) had also been removed, with layers of enhanced NO(y) at lower altitudes. Back trajectory calculations show that air parcels sampled inside the vortex had experienced temperatures as low as 188 K within the previous 12 days, consistent with a small amount of dehydration. The depth of the dehydrated layer (approximately 1 km) and the fact that trajectories passed through the region of ice saturation in one day imply selective growth of a small fraction of particles to sizes large enough (>10 microns) to be irreversibly removed on this timescale. Over 25% of the Arctic vortex in a 20-30 K range of 0 is estimated to have been dehydrated in this event.

  18. Dehydration and Denitrification in the Arctic Polar Vortex During the 1995-1996 Winter

    NASA Technical Reports Server (NTRS)

    Hintsa, E. J.; Newman, P. A.; Jonsson, H. H.; Webster, C. R.; May, R. D.; Herman, R. L.; Lait, L. R.; Schoeberl, M. R.; Elkins, J. W.; Wamsley, P. R.; Dutton, G. S.; Bui, T. P.; Kohn, D. W.; Anderson, J. G.

    1998-01-01

    Dehydration of more than 0.5 ppmv water was observed between 18 and 19 km (theta about 450-465 K) at the edge of the Arctic polar vortex on February 1, 1996. More than half the reactive nitrogen (NO(sub y)) had also been removed, with layers of enhanced (sub y) at lower altitudes. Back trajectory calculations show that air parcels sampled inside the vortex had experienced temperatures as low as 188 K within the previous 12 days, consistent with a small amount of dehydration. The depth of the dehydrated layer (about 1 km) and the fact that trajectories passed through the region of ice saturation in one day imply selective growth of a small fraction of particles to sizes large enough (>10 micron) to be irreversibly removed on this timescale. Over 25% of the Arctic vortex in a 20-30 K range of theta is estimated to have been dehydrated in this event.

  19. Dehydration and Denitrification in the Arctic Polar Vortex During the 1995-1996 Winter

    NASA Technical Reports Server (NTRS)

    Hintsa, E. J.; Newman, P. A.; Jonsson, H. H.; Webster, C. R.; May, R. D.; Herman, R. L.; Lait, L. R.; Schoeberl, M. R.; Elkins, J. W.; Wamsley, P. R.; Dutton, G. S.; Bui, T. P.; Kohn, D. W.; Anderson, J. G.

    1998-01-01

    Dehydration of more than 0.5 ppmv water was observed between 18 and 19 km (theta approximately 450-465 K) at the edge of the Arctic polar vortex on February 1, 1996. More than half the reactive nitrogen (NO(y)) had also been removed, with layers of enhanced NO(y) at lower altitudes. Back trajectory calculations show that air parcels sampled inside the vortex had experienced temperatures as low as 188 K within the previous 12 days, consistent with a small amount of dehydration. The depth of the dehydrated layer (approximately 1 km) and the fact that trajectories passed through the region of ice saturation in one day imply selective growth of a small fraction of particles to sizes large enough (>10 micrometers) to be irreversibly removed on this timescale. Over 25% of the Arctic vortex in a 20-30 K range Transport of theta is estimated to have been dehydrated in this event.

  20. Dehydration and Denitrification in the Arctic Polar Vortex During the 1995-1996 Winter

    NASA Technical Reports Server (NTRS)

    Hintsa, E. J.; Newman, P. A.; Jonsson, H. H.; Webster, C. R.; May, R. D.; Herman, R. L.; Lait, L. R.; Schoerberl, M. R.; Elkins, J. W.; Wamsley, P. R.

    1998-01-01

    Dehydration of more than 0.5 ppmv water was observed between 18 and 19 km (theta = 450-465 K) at the edge of the Arctic polar vortex on February 1, 1996. More than half the reactive nitrogen (NOy) had also been removed, with layers of enhanced NOy at lower altitudes. Back trajectory calculations show that air parcels sampled inside the vortex had experienced temperatures as low as 188 K within the previous 12 days, consistent with a small amount of dehydration. The depth of the dehydrated layer (approx. 1 km) and the fact that trajectories passed through the region of ice saturation in one day imply selective growth of a small fraction of particles to sizes large enough (>10 micrometers) to be irreversibly removed on this timescale. Over 25% of the Arctic vortex in a 20-30 K range of theta is estimated to have been dehydrated in this event.

  1. Membrane-based recovery and dehydration of alcohols from fermentation broths - of materials and modules

    EPA Science Inventory

    Distillation combined with molecular sieve dehydration is the current state of the art for fuel grade ethanol production from fermentation broths. As the liquid biofuels industry transitions to lignocellulosic feedstocks, expands the end product portfolio to include other alcoho...

  2. Liquid-phase and vapor-phase dehydration of organic/water solutions

    DOEpatents

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

    2011-08-23

    Processes for dehydrating an organic/water solution by pervaporation or vapor separation using fluorinated membranes. The processes are particularly useful for treating mixtures containing light organic components, such as ethanol, isopropanol or acetic acid.

  3. Mixed Matrix Silicone and Fluorosilicone/Zeolite 4A Membranes for Ethanol Dehydration by Pervaporation

    EPA Science Inventory

    The ability of homogeneous and mixed matrix membranes prepared using standard silicone rubber, poly(dimethylsiloxane) (PDMS), and fluorosilicone rubber, poly(trifluoropropylmethylsiloxane) (PTFPMS), to dehydrate ethanol by pervaporation was evaluated. Although PDMS is generally c...

  4. Effective hepatitis A virus inactivation during low-heat dehydration of contaminated green onions.

    PubMed

    Laird, David T; Sun, Yan; Reineke, Karl F; Shieh, Y Carol

    2011-08-01

    Preserving fruits and vegetables by dehydration is common; however, information is limited concerning viral survival on the produce during the process. This work demonstrated the effects of low heat dehydration on inactivating hepatitis A virus (HAV) on contaminated green onions. Inoculated and uninoculated onion samples were dehydrated at target temperatures of 45-65 °C for 20 h. HAV from artificially contaminated onions (fresh or dehydrated) was eluted by shaking at 145 rpm at 20 °C for 20 min with 3% beef extract, pH 8, and followed by 0.2 μM-membrane filtration before plaque assay and quantitative reverse transcription-polymerase chain reaction (qRT-PCR) analysis. Dilutions of the filtrates were made for obtaining countable plaques on FRhK-4 cell monolayers in 6-well plates, and also for eliminating inhibitors in qRT-PCR. Average water activity of the onions after 20 h-dehydration was 0.227, regardless of temperature used (47.9 °C or 65.1 °C). Eight dehydration trials resulted in a linear relationship between HAV inactivation and dehydration temperature, with HAV log reduction = 0.1372x(°C) - 5.5572, r(2) = 0.88. Therefore, the 20 h-heating at 47.8, 55.1, and 62.4 °C reduced infectious HAV in onions by 1, 2, and 3 logs respectively, the Z value being 7.3 °C. It was concluded that low heat dehydration using 62.5 °C or above could effectively inactivate HAV on contaminated onions by >3 logs. PMID:21569944

  5. Formation of Linear Polyenes in Thermal Dehydration of Polyvinyl Alcohol, Catalyzed by Phosphotungstic Acid

    NASA Astrophysics Data System (ADS)

    Tretinnikov, O. N.; Sushko, N. I.

    2015-01-01

    In order to obtain linear polyenes in polyvinyl alcohol films via acid-catalyzed thermal dehydration of the polyvinyl alcohol, we used phosphotungstic acid as the catalyst: a safe and heat-stable solid chemical compound. We established that phosphotungstic acid, introduced as solid nanoparticles into polyvinyl alcohol films, is a more effective dehydration catalyst than hydrochloric acid, since in contrast to HCl it does not evaporate from the film during heat treatment.

  6. Dehydration modifies guanidino compound concentrations in the different zones of the rat kidney.

    PubMed

    Levillain, Olivier; Marescau, Bart; Possemiers, Ilse; De Deyn, Paul

    2002-05-01

    Guanidino compounds (GCs) related to arginine (Arg) are unevenly distributed along the cortico-papillary axis of the rat kidney. Inasmuch as the concentration of alpha-keto-delta-guanidinovaleric acid (alpha-keto-delta-GVA), guanidinosuccinic acid (GSA), creatinine (CTN), gamma-guanidinobutyric acid (gamma-GBA) and methylguanidine (MG) increased steeply along the inner medulla in parallel to the urea and osmotic gradients, the question arose as to whether dehydration enhances their renal content and distribution. To examine this possibility, adult male rats were dehydrated by removing the drinking water for 24 or 48 h. The kidneys were sliced and cut in seven sections along the cortico-papillary axis. Twelve GCs were determined by liquid chromatography in each renal zone. Dehydration modified GC concentrations and regional distribution. The renal content of Arg, guanidine and MG was decreased while that of alpha-keto-delta-GVA, gamma-GBA, alpha- N-acetyl-arginine and homoarginine remained unchanged. In contrast, GSA, guanidinoacetic acid (GAA), creatine (CT), CTN and beta-guanidinopropionic acid (beta-GPA) concentrations were enhanced significantly in different renal zones after 24 and 48 h dehydration. In addition, the tissue level of GCs supplying energy, such as CT and beta-GPA, the precursor of CT (GAA) and its metabolite (CTN) were enhanced under dehydration. Arg and CT account for 80-90% of the GCs located in the renal cortex. Variations of some GC levels under dehydration may modify enzyme activities, renal metabolism and cell function. PMID:11976926

  7. Application of anhydrobiosis and dehydration of yeasts for non-conventional biotechnological goals.

    PubMed

    Rapoport, Alexander; Turchetti, Benedetta; Buzzini, Pietro

    2016-06-01

    Dehydration of yeast cells causes them to enter a state of anhydrobiosis in which their metabolism is temporarily and reversibly suspended. This unique state among organisms is currently used in the production of active dry yeasts, mainly used in baking and winemaking. In recent decades non-conventional applications of yeast dehydration have been proposed for various modern biotechnologies. This mini-review briefly summarises current information on the application of dry yeasts in traditional and innovative fields. It has been shown that dry yeast preparations can be used for the efficient protection, purification and bioremediation of the environment from heavy metals. The high sorption activity of dehydrated yeasts can be used as an interesting tool in winemaking due to their effects on quality and taste. Dry yeasts are also used in agricultural animal feed. Another interesting application of yeast dehydration is as an additional stage in new methods for the stable immobilisation of microorganisms, especially in cases when biotechnologically important strains have no affinity with the carrier. Such immobilisation methods also provide a new approach for the successful conservation of yeast strains that are very sensitive to dehydration. In addition, the application of dehydration procedures opens up new possibilities for the use of yeast as a model system. Separate sections of this review also discuss possible uses of dry yeasts in biocontrol, bioprotection and biotransformations, in analytical methods as well as in some other areas. PMID:27116970

  8. Repeated bouts of dehydration deplete nutrient reserves and reduce egg production in the mosquito Culex pipiens

    PubMed Central

    Benoit, Joshua B.; Patrick, Kevin R.; Desai, Karina; Hardesty, Jeffrey J.; Krause, Tyler B.; Denlinger, David L.

    2010-01-01

    In this study of the mosquito, Culex pipiens, we examined the impact of multiple bouts of dehydration and rehydration on survival, depletion of metabolic reserves and egg production in both non-diapausing and diapausing females. Mosquitoes provided with access to sugar during rehydration survived longer than those allowed to rehydrate without sugar, and their survival was similar to that of mosquitoes of the same age that were not dehydrated. Among mosquitoes not provided with sugar, each dehydration bout reduced the mosquito's dry mass – an effect likely to be due to the utilization of carbohydrates and lipid reserves. The toll on glycogen and lipid reserves is likely to be especially costly for diapausing mosquitoes that are dependent on these stored reserves for winter survival. Egg production in both non-diapausing and post-diapausing C. pipiens was also reduced in response to multiple bouts of dehydration. Although egg quality was not compromised, the number of eggs produced was reduced. Both non-diapausing and diapausing females can compensate for the nutrient loss due to dehydration by sugar feeding but the opportunity to feed on sugar is likely to be rarely available in the overwintering habitat of diapausing females, thus the impact of dehydration may be especially pronounced in overwintering populations of C. pipiens. PMID:20675546

  9. Organ Specific Proteomic Dissection of Selaginella bryopteris Undergoing Dehydration and Rehydration

    PubMed Central

    Deeba, Farah; Pandey, Ashutosh K.; Pandey, Vivek

    2016-01-01

    To explore molecular mechanisms underlying the physiological response of Selaginella bryopteris, a comprehensive proteome analysis was carried out in roots and fronds undergoing dehydration and rehydration. Plants were dehydrated for 7 days followed by 2 and 24 h of rehydration. In roots out of 59 identified spots, 58 protein spots were found to be up-regulated during dehydration stress. The identified proteins were related to signaling, stress and defense, protein and nucleotide metabolism, carbohydrate and energy metabolism, storage and epigenetic control. Most of these proteins remained up-regulated on first rehydration, suggesting their role in recovery phase also. Among the 90 identified proteins in fronds, about 49% proteins were up-regulated during dehydration stress. Large number of ROS scavenging proteins was enhanced on dehydration. Many other proteins involved in energy, protein turnover and nucleotide metabolism, epigenetic control were also highly upregulated. Many photosynthesis related proteins were upregulated during stress. This would have helped plant to recover rapidly on rehydration. This study provides a comprehensive picture of different cellular responses elucidated by the proteome changes during dehydration and rehydration in roots and fronds as expected from a well-choreographed response from a resurrection plant. PMID:27092152

  10. Effects of surface dehydration on mucosal wave amplitude and frequency in excised canine larynges

    PubMed Central

    Witt, Rachel E.; Taylor, Lindsay N.; Regner, Michael F.; Jiang, Jack J.

    2011-01-01

    Objective Evaluate the effect of vocal fold surface dehydration on mucosal wave amplitude and frequency. Study Design Controlled test-retest. Setting Larynges were mounted on an excised larynx phonation system and attached to a pseudolung in a triple-walled sound-attenuated room that eliminated background noise and maintained a stabilized room temperature and humidity level. Subjects and Methods High-speed video was recorded for eight excised canine larynges during exposure to dehumidified air at 20 cm H2O. Control trials consisted of high-speed videos recorded for two excised canine larynges during exposure to humidified air at the same pressure. Results In the majority of larynges, increased levels of dehydration were correlated with decreased amplitude and frequency. The slope of the linear regression fitted to the change in amplitude (p=0.003) as well as the percent change (p<0.001) between the initial and final trials were significantly decreased in dehydrated larynges. These measurements with respect to the change in frequency were also significantly decreased in dehydrated larynges (p<0.001; p=0.027). Conclusion Vocal fold surface dehydration caused a decrease in mucosal wave amplitude and frequency. This study provides objective, quantitative support for the mechanism of voice deterioration observed after extreme surface dehydration. PMID:21493398

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

    NASA Astrophysics Data System (ADS)

    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.

  12. Water incorporation in NAMs after antigorite and chlorite dehydration reactions

    NASA Astrophysics Data System (ADS)

    Padrón-Navarta, José Alberto; Hermann, Jörg

    2014-05-01

    Subduction zones play a fundamental role in the deep water cycle making the Earth unique among other terrestrial planets. Water is incorporated into hydrous minerals during seafloor alteration of the oceanic lithosphere. During subduction of the oceanic lithosphere, dehydration of these hydrous minerals produces a fluid phase. A part of this fluid phase will be recycled back to the Earth's surface through hydrothermal aqueous fluids or through hydrous arc magmas, whereas another part of the water will be transported to the deep mantle by Nominally Anhydrous Minerals (NAMs) such as olivine, pyroxene and garnet. The partitioning of water between these two processes is crucial for our understanding of the mantle-scale water recycling in the Earth. This can be investigated experimentally under water-saturated conditions because this situation is met during dehydration reactions. However relatively low temperature conditions for such reactions make challenging these experiments. An alternative can be found in the natural record. The Alpine Betic-Rif orogen together with Central and Western Alps offer an invaluable diversity of ultramafic lenses that record a significant range of pressure-temperature and cooling rates. Hence these samples portray an excellent data set of 24 samples to survey the transfer of fluids from hydrous phases (brucite, antigorite and chlorite) to NAMs (olivine, orthopyroxene, clinopyroxene and garnet). Well-studied samples from these localities have been selected for water measurement using FTIR spectroscopy. The selected suite comprises the following high-pressure peridotite outcrops: Malenco serpentinite, Cerro del Almirez (1.6-1.9 GPa and 680-710ºC), Alpe Arami (3.2 GPa and 840ºC), Cima di Gagnone (3.0 GPa and 750-800ºC) and Alpe Albion (0.6 GPa and 730ºC). The infrared signature of olivine in all localities contains water (hydroxyl groups) associated to intrinsic defects (mostly point defects related to Ti4+) and extrinsic submicroscopic

  13. Crustal Dehydration and Overpressure Development on the San Andreas Fault

    NASA Astrophysics Data System (ADS)

    Fulton, P. M.; Saffer, D. M.; Bekins, B. A.

    2005-12-01

    Previous authors have hypothesized that the apparent weakness of the San Andreas Fault may be explained by fluid overpressures resulting from the combination of crustal dehydration of the Franciscan mélange and the presence of a low-permeability serpentinite cap at its geologic contact with the Great Valley Sequence. We previously evaluated this hypothesis by calculating the spatial and temporal distribution of fluid sources and then incorporating these sources in 2-D models of fluid flow and heat transport perpendicular to the fault. We have refined our fluid source calculations using theoretical values of whole-rock H2O content and PT histories for the Franciscan crust in the wake of northward migration of the Mendocino Triple Junction (MTJ). The sources obtained reach peak values of 10-16 s-1. The coupled fluid flow and heat transport model now accommodates large-scale crustal deformation in a more rigorous manner by constructing new model grids after each change in crustal thickness. In the models, we assign permeability of the crust as a function of depth. A 500-m-thick, low-permeability serpentinite body (k=10-20 m-2) extends across the eastern half of the 50 km-wide model domain at a depth of 2 km. In addition, various model simulations include fault structures centered in the model domain such as: a 500 m wide low permeability fault barrier (kfault = kcrust/100), a fault conduit (kfault = kcrust x 100), a barrier within a 1.5 km wide conduit damage zone, and a conduit plugged by a 3 km-thick and 2 km-wide barrier simulating a broad, clay-rich, low-permeability zone, at shallow depth within the fault system, which is one possible interpretation of seismic and electromagnetic data. We also test additional scenarios to evaluate sensitivity to changes in model permeability. Model results show overpressures, as large as 162% of hydrostatic (62% of lithostatic) for the model with a serpentinite cap and fault barrier, develop within 4 Ma of Mendocino Triple

  14. Diamond Formation in association with Deep Mantle Dehydration Zones

    NASA Astrophysics Data System (ADS)

    Harte, B.

    2009-12-01

    2SiO4 with and fPer + mpv indicate the preservation of UM/LM boundary reaction, which from experimental data is expected to be sharply constrained in depth, though the presence of H2O will broaden the reaction zone due to the potential stability of hydrous ringwoodite. Considerations of the preservation of hydrous peridotitic assemblages in subduction zones (Komabayashi, 2006, AGU monograph), show that an initially cool subducted slab may preserve hydrous assemblages to the lower part of the upper mantle and into the lower mantle. Here stagnation and warming of the slab may cause dehydration with the formation of fluids/melts which provide the potential location for diamond formation. At the top of the Transition Zone, Bercovici and Karato (2003, Nature 245) have suggested the existence of a melt zone. The location of this melt zone at its intersection with the upper surface of a subducting slab, provides an ideal location for the crystallisation of the majorite assemblages from around the top of the Transition Zone. This also accords with the crustal carbon isotope signatures in the host diamonds and the wide variations in REE abundances in the majorites. Deep diamond inclusions provide strong evidence for dehydration zones near the top and bottom of the Transition Zone.

  15. Selective Brain Cooling Reduces Water Turnover in Dehydrated Sheep

    PubMed Central

    Strauss, W. Maartin; Hetem, Robyn S.; Mitchell, Duncan; Maloney, Shane K.; Meyer, Leith C. R.; Fuller, Andrea

    2015-01-01

    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 50kg 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. PMID:25675092

  16. Unwinding of double-stranded DNA helix by dehydration.

    PubMed Central

    Lee, C H; Mizusawa, H; Kakefuda, T

    1981-01-01

    Conformation changes of the double-stranded DNA helix in response to dehydration were investigated by monitoring, by agarose gel electrophoresis, the linking number of covalently closed circular DNA generated by ligation of linear DNA in the presence of different organic solvents or different temperatures. It was found that: (i) The DNA helix unwinds upon addition of certain organic solvents or elevation of temperature. (ii) The conformational change observed under the experimental conditions is a continuous process in response to the organic solvent concentration. (iii) The delta H of unwinding one linking of the DNA helix is constant at approximately 12.2 +/- 0.4 kcal/mol (1 kcal = 4.184 kJ); the corresponding delta S and d(delta S)/dn are 2nkR and 2kR, in which n is the relative equivalent linking number (referred to the state of delta S = 0 for unwinding) of the DNA, R is the gas constant, and k is equal to 1117/number of base pairs. The delta H, delta S, and d(delta S)/dn for unwinding i linkings are i X 12.2 kcal/mol, 2inkR, and 2ikR, respectively. (iv) d(delta S)/dn, like k, is inversely proportional to the number of base pairs in DNA. (v) Double-stranded DNAs of different chain lengths have average delta S = 35 cal/mol.K for unwinding one linking under the experimental conditions; this corresponds to 127 +/- 14 base pairs per "relative linking." Images PMID:7019913

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

    NASA Astrophysics Data System (ADS)

    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.

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

    NASA Astrophysics Data System (ADS)

    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

  19. In-situ Dehydration Studies of Fully K- Rb- and Cs-exchanged Natrolites

    SciTech Connect

    Y Lee; D Seoung; D Liu; M Park; S Hong; H Chen; J Bai; C Kao; T Vogt; Y Lee

    2011-12-31

    In-situ synchrotron X-ray powder diffraction studies of K-, Rb-, and Cs-exchanged natrolites between room temperature and 425 C revealed that the dehydrated phases with collapsed frameworks start to form at 175, 150, and 100 C, respectively. The degree of the framework collapse indicated by the unit-cell volume contraction depends on the size of the non-framework cation: K-exchanged natrolite undergoes an 18.8% unit-cell volume contraction when dehydrated at 175 C, whereas Rb- and Cs-exchanged natrolites show unit-cell volume contractions of 18.5 and 15.2% at 150 and 100 C, respectively. In the hydrated phases, the dehydration-induced unit-cell volume reduction diminishes as the cation size increases and reveals increasingly a negative slope as smaller cations are substituted into the pores of the natrolite structure. The thermal expansion of the unit-cell volumes of the dehydrated K-, Rb-, and Cs-phases have positive thermal expansion coefficients of 8.80 x 10{sup -5} K{sup -1}, 1.03 x 10{sup -4} K{sup 01}, and 5.06 x 10{sup -5} K{sup -1}, respectively. Rietveld structure refinements of the dehydrated phases at 400 C reveal that the framework collapses are due to an increase of the chain rotation angles, {Psi}, which narrow the channels to a more elliptical shape. Compared to their respective hydrated structures at ambient conditions, the dehydrated K-exchanged natrolite at 400 C shows a 2.2-fold increase in {Psi}, whereas the dehydrated Rb- and Cs-natrolites at 400 C reveal increases of {Psi} by ca. 3.7 and 7.3 times, respectively. The elliptical channel openings of the dehydrated K-, Rb-, to Cs-phases become larger as the cation size increases. The disordered non-framework cations in the hydrated K-, Rb-, and Cs-natrolite order during dehydration and the subsequent framework collapse. The dehydrated phases of Rb- and Cs-natrolite can be stabilized at ambient conditions.

  20. Switching control of sympathetic activity from forebrain to hindbrain in chronic dehydration

    PubMed Central

    Colombari, Débora S A; Colombari, Eduardo; Freiria-Oliveira, Andre H; Antunes, Vagner R; Yao, Song T; Hindmarch, Charles; Ferguson, Alastair V; Fry, Mark; Murphy, David; Paton, Julian F R

    2011-01-01

    Abstract We investigated the mechanisms responsible for increased blood pressure and sympathetic nerve activity (SNA) caused by 2–3 days dehydration (DH) both in vivo and in situ preparations. In euhydrated (EH) rats, systemic application of the AT1 receptor antagonist Losartan and subsequent pre-collicular transection (to remove the hypothalamus) significantly reduced thoracic (t)SNA. In contrast, in DH rats, Losartan, followed by pre-collicular and pontine transections, failed to reduce tSNA, whereas transection at the medulla–spinal cord junction massively reduced tSNA. In DH but not EH rats, selective inhibition of the commissural nucleus tractus solitarii (cNTS) significantly reduced tSNA. Comparable data were obtained in both in situ and in vivo (anaesthetized/conscious) rats and suggest that following chronic dehydration, the control of tSNA transfers from supra-brainstem structures (e.g. hypothalamus) to the medulla oblongata, particularly the cNTS. As microarray analysis revealed up-regulation of AP1 transcription factor JunD in the dehydrated cNTS, we tested the hypothesis that AP1 transcription factor activity is responsible for dehydration-induced functional plasticity. When AP1 activity was blocked in the cNTS using a viral vector expressing a dominant negative FosB, cNTS inactivation was ineffective. However, tSNA was decreased after pre-collicular transection, a response similar to that seen in EH rats. Thus, the dehydration-induced switch in control of tSNA from hypothalamus to cNTS seems to be mediated via activation of AP1 transcription factors in the cNTS. If AP1 activity is blocked in the cNTS during dehydration, sympathetic activity control reverts back to forebrain regions. This unique reciprocating neural structure-switching plasticity between brain centres emphasizes the multiple mechanisms available for the adaptive response to dehydration. PMID:21708906

  1. Investigating dehydration from compacts using terahertz pulsed, Raman, and near-infrared spectroscopy.

    PubMed

    Kogermann, Karin; Zeitler, J Axel; Rantanen, Jukka; Rades, Thomas; Taday, Philip F; Pepper, Michael; Heinämäki, Jyrki; Strachan, Clare J

    2007-12-01

    The purpose of this study was to investigate the dehydration of piroxicam monohydrate (PRXMH) in compacts using terahertz pulsed spectroscopy (TPS), Raman spectroscopy, and reflectance near-infrared (NIR) spectroscopy. Compacts were prepared by using PRXMH and poly(tetrafluoro)ethylene powders and combining them in three different manners before compression to produce compacts in which the PRXMH was dispersed throughout the compact, deposited on one face of the compact, or included as a layer within the compact. TPS was a suitable technique to assess the effect of sample preparation on dehydration, whereas Raman and NIR spectroscopy were limited by their sampling depth and the interference of the polymer matrix. TPS revealed that the dehydration behavior depended largely on the compact preparation method. Non-isothermal dehydration was investigated with all three spectroscopic techniques, combined with principal component analysis (PCA) on samples where the PRXMH was deposited on one face of the compact. In addition, variable temperature X-ray powder diffractometry (VT-XRPD) was used to verify the transformation from PRXMH to anhydrous PRX form I, while thermogravimetric analysis (TGA) was used to monitor the water loss. All three spectroscopic techniques allowed in situ monitoring of the dehydration from the surface layers of the compacts. TPS and Raman spectroscopy detected structural changes of the crystal, while NIR spectroscopy was more sensitive to water loss. PCA of the TPS, Raman spectroscopy, and XRPD data revealed similar dehydration profiles. In contrast, the NIR spectroscopy profile was more similar to the TGA results. The spectroscopic techniques were more suitable than slower techniques such as VT-XRPD for monitoring rapid structural changes that occurred during the dehydration. PMID:18198016

  2. Transcriptome sequencing and whole genome expression profiling of chrysanthemum under dehydration stress

    PubMed Central

    2013-01-01

    Background Chrysanthemum is one of the most important ornamental crops in the world and drought stress seriously limits its production and distribution. In order to generate a functional genomics resource and obtain a deeper understanding of the molecular mechanisms regarding chrysanthemum responses to dehydration stress, we performed large-scale transcriptome sequencing of chrysanthemum plants under dehydration stress using the Illumina sequencing technology. Results Two cDNA libraries constructed from mRNAs of control and dehydration-treated seedlings were sequenced by Illumina technology. A total of more than 100 million reads were generated and de novo assembled into 98,180 unique transcripts which were further extensively annotated by comparing their sequencing to different protein databases. Biochemical pathways were predicted from these transcript sequences. Furthermore, we performed gene expression profiling analysis upon dehydration treatment in chrysanthemum and identified 8,558 dehydration-responsive unique transcripts, including 307 transcription factors and 229 protein kinases and many well-known stress responsive genes. Gene ontology (GO) term enrichment and biochemical pathway analyses showed that dehydration stress caused changes in hormone response, secondary and amino acid metabolism, and light and photoperiod response. These findings suggest that drought tolerance of chrysanthemum plants may be related to the regulation of hormone biosynthesis and signaling, reduction of oxidative damage, stabilization of cell proteins and structures, and maintenance of energy and carbon supply. Conclusions Our transcriptome sequences can provide a valuable resource for chrysanthemum breeding and research and novel insights into chrysanthemum responses to dehydration stress and offer candidate genes or markers that can be used to guide future studies attempting to breed drought tolerant chrysanthemum cultivars. PMID:24074255

  3. Water Temperature, Voluntary Drinking and Fluid Balance in Dehydrated Taekwondo Athletes

    PubMed Central

    Khamnei, Saeed; Hosseinlou, Abdollah; Zamanlu, Masumeh

    2011-01-01

    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. Key points For athletes dehydrated in hot environments, maximum voluntary drinking and best hydration state occurs with 16°C water. Provision of fluid needs and thermal needs could be balanced using 16°C water. Drinking 16°C water (nearly the temperature of cool tap water) could be recommended for exercise in the heat. PMID:24149564

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

    NASA Astrophysics Data System (ADS)

    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.

  5. Temperature dependent elasticity and damping in dehydrated sandstone

    NASA Astrophysics Data System (ADS)

    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. Glycerol dehydrates oedematous as well as normal brain in dogs.

    PubMed

    Wang, J Y; Chen, J L

    1994-04-01

    1. Although the effect of glycerol on reducing intracranial pressure has been widely investigated, only a few studies have reported its dehydrating effect on brain oedema caused by infarction, ischaemia, microembolism and cold injury, but none on traumatic oedema. In this study the effects of glycerol (1 g/kg, i.v. bolus infusion at a rate of 0.04 g/kg per min) on traumatic and cryogenic cerebral oedema and on normal brain were compared in the anaesthetized dog. The tissue water content was measured with the gravimetric method. 2. Oedema resulting from mechanical trauma was initiated 4 h prior to treatment with glycerol (8 dogs) or vehicle (5 dogs) by closed head contusion with fixed force under general anaesthesia. Tissue samples underneath the region of contusion were taken, before and 1 h after infusion of glycerol or vehicle, for the measurement of water content. 3. Glycerol infusion decreased the water content in white matter of the traumatic brain model from 76.54 +/- 1.70% to 70.73 +/- 1.54% (P < 0.001). In normal brain the reduction was from 68.42 +/- 0.48% to 65.36 +/- 0.39% (P < 0.001). Neither vehicle nor glycerol infusion resulted in significant changes in specific gravity of the gray matter. 4. Cryogenic oedema was initiated 3 h prior to the infusion of glycerol or vehicle by applying unilaterally a brass conical cup (bottom diameter 1 cm) filled with dry ice-acetone (-65 degrees C) to the exposed dura for 1 min. The contralateral hemisphere, which was not subjected to cold injury, was used for determination of water content of normal gray and white matter. 5. Glycerol infusion decreased the water content in the white matter of the cold-injured region from 75.38 +/- 0.69% to 72.57 +/- 0.58% (P < 0.001). In the normal white matter the reduction was from 68.63 +/- 0.34% to 65.48 +/- 0.49% (P < 0.001). 6. Our data indicate that glycerol decreases water content of the white matter in traumatic and cold-injured oedematous brain as well as in normal brain

  7. Pyropia yezoensis can utilize CO2 in the air during moderate dehydration

    NASA Astrophysics Data System (ADS)

    Zhou, Wei; He, Linwen; Yang, Fang; Lin, Apeng; Zhang, Baoyu; Niu, Jianfeng; Wang, Guangce

    2014-03-01

    Pyropia yezoensis, an intertidal seaweed, experiences regular dehydration and rehydration with the tides. In this study, the responses of P. yezoensis to dehydration and rehydration under high and low CO2 concentrations ((600-700)×10-6 and (40-80)×10-6, named Group I and Group II respectively) were investigated. The thalli of Group I had a significantly higher effective photosystem II quantum yield than the thalli of Group II at 71% absolute water content (AWC). There was little difference between thalli morphology, total Rubisco activity and total protein content at 100% and 71% AWC, which might be the basis for the normal performance of photosynthesis during moderate dehydration. A higher effective photosystem I quantum yield was observed in the thalli subjected to a low CO2 concentration during moderate dehydration, which might be caused by the enhancement of cyclic electron flow. These results suggested that P. yezoensis can directly utilize CO2 in ambient air during moderate dehydration.

  8. CH2-units on (poly-)ethylene glycol radially dehydrate cytoplasm of resting skinned skeletal muscle.

    PubMed

    Kimura, Masako; Takemori, Shigeru

    2008-06-01

    Observing the optical cross-section and electron micrographs of mechanically skinned fibres of frog skeletal muscle, we found that ethylene glycols (EGs) of small (mono-, di-, tri- and tetra-EGs; M(r) 62-194) and medium (poly-EGs; M(r) 900 and 3350) molecular weights efficiently dehydrate the fibres to shrink them radially without microscopic inhomogeneity. The medium-sized poly-EGs at 30% weight/weight concentration absorbed almost all the evaporable water from the fibre. Passive tension measurement at near slack sarcomere spacing indicated that this dehydration by EGs did not accompany longitudinal fibre shrinkage. Chemically relevant fully hydric alcohols (glycerol, threitol, ribitol and mannitol; M(r) 92-182) showed no appreciable dehydrating ability on fibres. An intimate correlation was found between fibre dehydration and CH(2)-concentration of the solutions. Viscosity measurements indicated that the hydrodynamic radii of the alcohols were comparable to those of the small EGs. Therefore, hydrodynamic radii are not a primary determinant of the dehydrating ability. Additionally, CH(2)-concentration of EGs but not alcohols was found to correlate intimately with the measured viscosity of the bulk solution of EGs. These results suggested that the interaction between water molecules and CH(2)-units in crowded cytoplasm of skeletal muscle affects cytoplasm as a whole to realize anisotropic fibre shrinkage. PMID:18583358

  9. Airway Surface Dehydration Aggravates Cigarette Smoke-Induced Hallmarks of COPD in Mice

    PubMed Central

    Seys, Leen J. M.; Verhamme, Fien M.; Dupont, Lisa L.; Desauter, Elke; Duerr, Julia; Seyhan Agircan, Ayca; Conickx, Griet; Joos, Guy F.; Brusselle, Guy G.

    2015-01-01

    Introduction Airway surface dehydration, caused by an imbalance between secretion and absorption of ions and fluid across the epithelium and/or increased epithelial mucin secretion, impairs mucociliary clearance. Recent evidence suggests that this mechanism may be implicated in chronic obstructive pulmonary disease (COPD). However, the role of airway surface dehydration in the pathogenesis of cigarette smoke (CS)-induced COPD remains unknown. Objective We aimed to investigate in vivo the effect of airway surface dehydration on several CS-induced hallmarks of COPD in mice with airway-specific overexpression of the β-subunit of the epithelial Na+ channel (βENaC). Methods βENaC-Tg mice and wild-type (WT) littermates were exposed to air or CS for 4 or 8 weeks. Pathological hallmarks of COPD, including goblet cell metaplasia, mucin expression, pulmonary inflammation, lymphoid follicles, emphysema and airway wall remodelling were determined and lung function was measured. Results Airway surface dehydration in βENaC-Tg mice aggravated CS-induced airway inflammation, mucin expression and destruction of alveolar walls and accelerated the formation of pulmonary lymphoid follicles. Moreover, lung function measurements demonstrated an increased compliance and total lung capacity and a lower resistance and hysteresis in βENaC-Tg mice, compared to WT mice. CS exposure further altered lung function measurements. Conclusions We conclude that airway surface dehydration is a risk factor that aggravates CS-induced hallmarks of COPD. PMID:26066648

  10. Plant Organellar Proteomics in Response to Dehydration: Turning Protein Repertoire into Insights

    PubMed Central

    Gupta, Deepti B.; Rai, Yogita; Gayali, Saurabh; Chakraborty, Subhra; Chakraborty, Niranjan

    2016-01-01

    Stress adaptation or tolerance in plants is a complex phenomenon involving changes in physiological and metabolic processes. Plants must develop elaborate networks of defense mechanisms, and adapt to and survive for sustainable agriculture. Water-deficit or dehydration is the most critical environmental factor that plants are exposed to during their life cycle, which influences geographical distribution and productivity of many crop species. The cellular responses to dehydration are orchestrated by a series of multidirectional relays of biochemical events at organelle level. The new challenge is to dissect the underlying mechanisms controlling the perception of stress signals and their transmission to cellular machinery for activation of adaptive responses. The completeness of current descriptions of spatial distribution of proteins, the relevance of subcellular locations in diverse functional processes, and the changes of protein abundance in response to dehydration hold the key to understanding how plants cope with such stress conditions. During past decades, organellar proteomics has proved to be useful not only for deciphering reprograming of plant responses to dehydration, but also to dissect stress–responsive pathways. This review summarizes a range of organellar proteomics investigations under dehydration to gain a holistic view of plant responses to water-deficit conditions, which may facilitate future efforts to develop genetically engineered crops for better adaptation. PMID:27148291

  11. Dehydration of Glucose to 5-Hydroxymethylfurfural Using Nb-doped Tungstite.

    PubMed

    Yue, Chaochao; Li, Guanna; Pidko, Evgeny A; Wiesfeld, Jan J; Rigutto, Marcello; Hensen, Emiel J M

    2016-09-01

    Dehydration of glucose to 5-hydroxymethylfurfural (HMF) remains a significant problem in the context of the valorization of lignocellulosic biomass. Hydrolysis of WCl6 and NbCl5 leads to precipitation of Nb-containing tungstite (WO3 ⋅H2 O) at low Nb content and mixtures of tungstite and niobic acid at higher Nb content. Tungstite is a promising catalyst for the dehydration of glucose to HMF. Compared with Nb2 O5 , fewer by-products are formed because of the low Brønsted acidity of the (mixed) oxides. In water, an optimum yield of HMF was obtained for Nb-W oxides with low Nb content owing to balanced Lewis and Brønsted acidity. In THF/water, the strong Lewis acidity and weak Brønsted acidity caused the reaction to proceed through isomerization to fructose and dehydration of fructose to a partially dehydrated intermediate, which was identified by LC-ESI-MS. The addition of HCl to the reaction mixture resulted in rapid dehydration of this intermediate to HMF. The HMF yield obtained in this way was approximately 56 % for all tungstite catalysts. Density functional theory calculations show that the Lewis acid centers on the tungstite surface can isomerize glucose into fructose. Substitution of W by Nb lowers the overall activation barrier for glucose isomerization by stabilizing the deprotonated glucose adsorbate. PMID:27493127

  12. A New Freezing Method Using Pre-Dehydration by Microwave-Vacuum Drying

    NASA Astrophysics Data System (ADS)

    Tsuruta, Takaharu; Hamidi, Nurkholis

    Partial dehydration by microwave-vacuum drying has been applied to tuna and strawberry in order to reduce cell-damages caused by the formation of large ice-crystals during freezing. The samples were subjected to microwave vacuum drying at pressure of 5 kPa and temperature less than 27°C to remove small amount of water prior to freezing. The tuna were cooled by using the freezing chamber at temperature -50°C or -150°C, while the strawberries were frozen at temperature -30°C or -80°C, respectively. The temperature transients in tuna showed that removing some water before freezing made the freezing time shorter. The observations of ice crystal clearly indicated that rapid cooling and pre-dehydration prior to freezing were effective in minimizing the size of ice crystal. It is also understood that the formation of large ice crystals has a close relation to the cell damages. After thawing, the observation of microstructure was done on the tuna and strawberry halves. The pre-dehydrated samples showed a better structure than the un-dehydrated one. It is concluded that the pre-dehydration by microwave-vacuum drying is one promising method for the cryo-preservation of foods.

  13. Anomalous dehydration of the TTL during January 2013: evidence from balloon, aircraft and satellite observations

    NASA Astrophysics Data System (ADS)

    Khaykin, Sergey; Pommereau, Jean-Pierre; Hauchecorne, Alain; Rivière, Emmanuel; Amarouche, Nadir; Ghysel, Melanie; Wienhold, Frank; Held, Gerard; Evan, Stephanie; Thornberry, Troy; Rollins, Andrew; Fahey, David; Vömel, Holger; Fujiwara, Masatomo; Rosenlof, Karen

    2015-04-01

    The goal of this study is to comprehensively document an anomalous dehydration of the Tropical Tropopause Layer (TTL) related to a major Sudden Stratospheric Warming (SSW) in January 2013. The analysis involves the data of balloon soundings of water vapour at various tropical locations using FLASH-B, Pico-SDLA and CFH hygrometers as well as NOAA Water instrument flown onboard high-altitude Global Hawk aircraft. Simultaneous water vapour and backscatter measurements by FLASH-B and COBALD sondes provide information on tropopause clouds formation process. Satellite observations of water vapour by Aura MLS are used to derive the deviation from climatological values. Trajectory modeling is applied for locating the dehydration source spots. Spatiotemporal evolution of dehydration at different scales is characterized after combining the consistent in situ and satellite water vapour observations. All data sets provide evidence of rapid and severe dehydration of the TTL throughout the tropical belt shortly after the onset of SSW. In situ measurements around the Cold Point Tropopause (CPT) show up to 2 ppmv of negative deviation from MLS 10-year climatology with extreme water mixing ratios below 1 ppmv in the Western Pacific region. The TTL dehydration case of 2013 is compared with previous similar occurrences and the role of extra-tropical dynamics in setting the global stratospheric water budget through thermal response in the TTL is pointed out

  14. (100) facets of γ-Al2O3: the active surfaces for alcohol dehydration reactions

    SciTech Connect

    Kwak, Ja Hun; Mei, Donghai; Peden, Charles HF; Rousseau, Roger J.; Szanyi, Janos

    2011-05-01

    Temperature programmed desorption (TPD) of ethanol, and methanol dehydration reaction were studied on γ-Al2O3 in order to identify the catalytic active sites for alcohol dehydration reactions. Two high temperature (> 473 K) desorption features were observed following ethanol adsorption. Samples calcined at T≤473 K displayed a desorption feature in the 523-533 K temperature range, while those calcined at T ≥ 673 K showed a single desorption feature at 498 K. The switch from the high to low temperature ethanol desorption correlated well with the dehydroxylation of the (100) facets of γ-Al2O3 that was predicted at 550 K DFT calculations. Theoretical DFT simulations of the mechanism of dehydration. on clean and hydroxylated γ-Al2O3(100) surfaces, find that a concerted elimination of ethylene from an ethanol molecule chemisorbed at an Al3+ pentacoordinated site is the rate limiting step for catalytic cycle on both surfaces. Furthermore, titration of the pentacoordinate Al3+ sites on the (100) facets of γ-Al2O3 by BaO completely turned off the methanol dehydration reaction activity. These results unambiguously demonstrate that only the (100) facets on γ-Al2O3 are the catalytic active surfaces for alcohol dehydration.

  15. Ethanol dehydration in HZSM-5 studied by density functional theory: evidence for a concerted process.

    PubMed

    Kim, Seonah; Robichaud, David J; Beckham, Gregg T; Paton, Robert S; Nimlos, Mark R

    2015-04-16

    Dehydration over acidic zeolites is an important reaction class for the upgrading of biomass pyrolysis vapors to hydrocarbon fuels or to precursors for myriad chemical products. Here, we examine the dehydration of ethanol at a Brønsted acid site, T12, found in HZSM-5 using density functional theory (DFT). The geometries of both cluster and mixed quantum mechanics/molecular mechanics (QM:MM) models are prepared from the ZSM-5 crystal structure. Comparisons between these models and different DFT methods are conducted to show similar results among the models and methods used. Inclusion of the full catalyst cavity through a QM:MM approach is found to be important, since activation barriers are computed on average as 7 kcal mol(-1) lower than those obtained with a smaller cluster model. Two different pathways, concerted and stepwise, have been considered when examining dehydration and deprotonation steps. The current study shows that a concerted dehydration process is possible with a lower (4-5 kcal mol(-1)) activation barrier while previous literature studies have focused on a stepwise mechanism. Overall, this work demonstrates that fairly high activation energies (∼50 kcal mol(-1)) are required for ethanol dehydration. A concerted mechanism is favored over a stepwise mechanism because charge separation in the transition state is minimized. QM:MM approaches appear to provide superior results to cluster calculations due to a more accurate representation of charges on framework oxygen atoms. PMID:25802969

  16. Optical mechanical refinement of human amniotic membrane by dehydration and cross-linking.

    PubMed

    Tanaka, Yuji; Kubota, Akira; Yokokura, Shunji; Uematsu, Masafumi; Shi, Dong; Yamato, Masayuki; Okano, Teruo; Quantock, Andrew J; Nishida, Kohji

    2012-10-01

    The aim of this study was to develop a method for refining the optical and mechanical properties of human amniotic membrane (AM) to provide ophthalmic transparent implants for use during severe donor cornea shortages. AM was allowed to gradually dehydrate at 4-8 °C with and without chemical cross-linking. To improve the transparency of AM, a simple dehydration process using a refrigerator at 4-8 °C overnight was examined. For further improvements, dehydrated AM was then cross-linked with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and N-hydroxy-succimide before rehydration. Light transmittance and tensile strength of individual specimens were evaluated. Light transmittance of AM improved from 50.9-77.7% at 550 nm by this simple low temperature dehydration process. Its high light transmittance was partially maintained at 70.1%, even after rehydration with normal saline. Interestingly, chemically cross-linked AM showed a significantly greater light transmittance of 81.5% under wet conditions. In addition, tensile strength was significantly increased after cross-linking from 2.32 N/mm(2) (native tissue) to 11.78 N/mm(2) (cross-linked specimens). Light transmittance and tensile strength were successfully improved by these approaches, including low temperature dehydration with and without chemical cross-linking. The use of refined AM could be feasible for use in current and future ophthalmic treatments. PMID:22489071

  17. Plant Organellar Proteomics in Response to Dehydration: Turning Protein Repertoire into Insights.

    PubMed

    Gupta, Deepti B; Rai, Yogita; Gayali, Saurabh; Chakraborty, Subhra; Chakraborty, Niranjan

    2016-01-01

    Stress adaptation or tolerance in plants is a complex phenomenon involving changes in physiological and metabolic processes. Plants must develop elaborate networks of defense mechanisms, and adapt to and survive for sustainable agriculture. Water-deficit or dehydration is the most critical environmental factor that plants are exposed to during their life cycle, which influences geographical distribution and productivity of many crop species. The cellular responses to dehydration are orchestrated by a series of multidirectional relays of biochemical events at organelle level. The new challenge is to dissect the underlying mechanisms controlling the perception of stress signals and their transmission to cellular machinery for activation of adaptive responses. The completeness of current descriptions of spatial distribution of proteins, the relevance of subcellular locations in diverse functional processes, and the changes of protein abundance in response to dehydration hold the key to understanding how plants cope with such stress conditions. During past decades, organellar proteomics has proved to be useful not only for deciphering reprograming of plant responses to dehydration, but also to dissect stress-responsive pathways. This review summarizes a range of organellar proteomics investigations under dehydration to gain a holistic view of plant responses to water-deficit conditions, which may facilitate future efforts to develop genetically engineered crops for better adaptation. PMID:27148291

  18. The dehydration kinetics of gypsum at high pressure and high temperature

    NASA Astrophysics Data System (ADS)

    Liu, Chuanjiang; Zheng, Haifei; Wang, Duojun

    2015-07-01

    An in situ dehydration kinetics study of gypsum under water-saturated condition was performed in the temperature and pressure ranges of 383-423 K and 343-1085 MPa by using a hydrothermal diamond anvil cell and Raman spectroscopy. Kinetic analysis shows that the dehydration rate k increases with pressure, suggesting a negative pressure dependence on dehydration rate. The elevation of temperature can contribute to the dehydration. The n values increase with pressure, indicating that the nucleation process becomes slower relative to the growth process. According to the n values of ∼1.0, the dehydration of gypsum is dominated by an instantaneous nucleation and diffusion-controlled growth mechanism. The obtained average activation volume ▵V is equal to 5.69 cm3/mol and the calculated activation energy Ea and the pre-exponential factor A are 66.9 kJ/mol and 4.66 × 105 s-1. The activation energy may be dependent upon grain size, shape, temperature and pressure, and surrounding water.

  19. Impact induced dehydration of serpentine and the evolution of planetary atmospheres

    SciTech Connect

    Lange, M.A.; Ahrens, T.J.

    1982-11-15

    Shock recovery experiments in the 25 to 45 GPa range on antigorite serpentine determine the amount of shock-induced loss of structural water as a function of shock pressure. Infrared absorption spectra of shock recovered samples demonstrate systematic changes in the amount of structural water and molecular, surface adsorbed water. These yield qualitative estimates of shock-induced water loss and demonstrate that a portion of the shock release structural water is readsorbed on interfacial grain surfaces. Determination of the post-shock water content of the shocked samples relates shock-induced water loss and shock pressure. Based on the present results and theoretical predictions, we conclude that shock pressures of from 20 to approx.60 GPa induce incipient to complete water loss, respectively. This result agrees closely with theoretical estimates for total dehydration. The dehydration interval and the activation energies for dehydration in shocked samples decrease systematically with increasing shock pressure as experienced by the sample. We believe the present experiments are applicable to describing dehydration processes of serpentine-like minerals in the accretional environment of the terrestrial planets. We conclude that complete loss of structural water in serpentine could have occurred from accretional impacts of approx.3 km/sec when earth and Venus have grown to about 50% of their final size. Accreting planetesimals, impacting Mars, never reached velocities sufficient for complete dehydration of serpentine. Our results support a model in which an impact generated atmosphere/hydrosphere forms while the earth is accreting.

  20. ABI3 mediates dehydration stress recovery response in Arabidopsis thaliana by regulating expression of downstream genes.

    PubMed

    Bedi, Sonia; Sengupta, Sourabh; Ray, Anagh; Nag Chaudhuri, Ronita

    2016-09-01

    ABI3, originally discovered as a seed-specific transcription factor is now implicated to act beyond seed physiology, especially during abiotic stress. In non-seed plants, ABI3 is known to act in desiccation stress signaling. Here we show that ABI3 plays a role in dehydration stress response in Arabidopsis. ABI3 gene was upregulated during dehydration stress and its expression was maintained during subsequent stress recovery phases. Comparative gene expression studies in response to dehydration stress and stress recovery were done with genes which had potential ABI3 binding sites in their upstream regulatory regions. Such studies showed that several genes including known seed-specific factors like CRUCIFERIN1, CRUCIFERIN3 and LEA-group of genes like LEA76, LEA6, DEHYDRIN LEA and LEA-LIKE got upregulated in an ABI3-dependent manner, especially during the stress recovery phase. ABI3 got recruited to regions upstream to the transcription start site of these genes during dehydration stress response through direct or indirect DNA binding. Interestingly, ABI3 also binds to its own promoter region during such stress signaling. Nucleosomes covering potential ABI3 binding sites in the upstream sequences of the above-mentioned genes alter positions, and show increased H3 K9 acetylation during stress-induced transcription. ABI3 thus mediates dehydration stress signaling in Arabidopsis through regulation of a group of genes that play a role primarily during stress recovery phase. PMID:27457990

  1. Crustal Recycling, Mantle Dehydration and the Thermal Evolution of Mars

    NASA Astrophysics Data System (ADS)

    Morschhauser, A.; Grott, M.; Breuer, D.

    2010-12-01

    We have reinvestigated the coupled thermal and crustal evolution of Mars using 1D parametrized thermal evolution models [1] and taking new data concerning the content and distribution of heat producing elements [2] as well as new laboratory data concerning the flow behavior of iron-rich olivine [3] into account. The high enrichment of radioactive elements in the crust leads to a less efficient heat transport from the lithospheric base, resulting in a thinning of the stagnant lid. If the stagnant lid becomes thinner than the crust, crustal material can be recycled back into the mantle by the vigourous convective motion. However, crustal recycling appears to be incompatible with an early separation of geochemical reservoirs [4] and valid models are required to show no episodes of crustal recycling. Furthermore, admissible models have to reproduce the Martian crust formation history and to allow the formation of partial melt under present-day mantle conditions. Taking dehydration stiffening of the mantle into account, we find that admissible models have low initial upper mantle temperatures between 1600 and 1700 K, a primordial crustal thickness of 30 km, and an initially wet mantle rheology. The crust formation process on Mars would then have been driven by the extraction of a primordial crust after core formation which was cooling the mantle to temperatures close to the peridotite solidus. The second stage of global crust formation took place over a more extended period of time, waning at around 1300-1700 Myr, and was driven by heat produced by the decay of radioactive elements. Finally, present-day volcanism is explained by convective mantle plumes and thermal insulation under regions of locally thickened crust. Water extraction from the mantle was found to be relatively efficient and close to 50 percent of the total inventory is lost from the mantle in most models. Assuming an initial mantle water content of 100 ppm and that 10% of the extracted water is supplied

  2. Severe hypernatremic dehydration and metabolic acidosis due to neonatal intestinal microvillus inclusion disease.

    PubMed

    Shahid, Shaneela; Fraser, Douglas D; Driman, David K; Bax, Kevin C

    2012-01-01

    Neonatal microvillus inclusion disease (MID) is a congenital secretory diarrhea diagnosed by morphological enterocyte abnormalities on histology. The secretory diarrhea associated with MID occurs within the first few hours of birth and is exacerbated by enteral feeding. Affected newborns will die of dehydration and acid-base disturbances if MID is not rapidly recognized and treated with massive intravenous fluid replacement and gut rest. We report a case of a 4-day-old neonate presenting with 18% weight loss, hypernatremic dehydration and metabolic acidosis. Despite aggressive fluid resuscitation (206 ml/kg for the first 24 h), the dehydration and metabolic acidosis were only minimally improved. The diapers were found soaked with clear, non-odorous fluid on repeated examinations. Persistent secretory diarrhea was suspected. Stool electrolytes analyses showed a high NaCl content typical of secretory diarrhea and intestinal biopsy with electron microscopy was diagnostic of MID. PMID:21968248

  3. Influence of Air Temperature and Humidity on Dehydration Equilibria and Kinetics of Theophylline

    PubMed Central

    Touil, Amira; Peczalski, Roman; Timoumi, Souad; Zagrouba, Fethi

    2013-01-01

    The effect of hygrothermal conditions (air temperature and relative humidity) on the dehydration of theophylline monohydrate was investigated. Firstly, the equilibrium states of theophylline were investigated. The data from gravimetric analysis at constant temperature and humidity were reported as desorption isotherms. The PXRD analysis was used to identify the different polymorphic forms of theophylline: the monohydrate, the metastable anhydrate, and the stable anhydrate. Solid-solid phase diagrams for two processing times were proposed. Secondly, the dehydration kinetics were studied. The water content evolutions with time were recorded at several temperatures from 20°C to 80°C and several relative humidities from 4% to 50%. Different mathematical models were used to fit the experimental data. The spatially averaged solution of 2D Fickian transient diffusion equation best represented the water mass loss versus time experimental relationship. The dehydration rate constant was found to increase exponentially with air temperature and to decrease exponentially with air relative humidity. PMID:26556000

  4. Influence of Air Temperature and Humidity on Dehydration Equilibria and Kinetics of Theophylline.

    PubMed

    Touil, Amira; Peczalski, Roman; Timoumi, Souad; Zagrouba, Fethi

    2013-01-01

    The effect of hygrothermal conditions (air temperature and relative humidity) on the dehydration of theophylline monohydrate was investigated. Firstly, the equilibrium states of theophylline were investigated. The data from gravimetric analysis at constant temperature and humidity were reported as desorption isotherms. The PXRD analysis was used to identify the different polymorphic forms of theophylline: the monohydrate, the metastable anhydrate, and the stable anhydrate. Solid-solid phase diagrams for two processing times were proposed. Secondly, the dehydration kinetics were studied. The water content evolutions with time were recorded at several temperatures from 20°C to 80°C and several relative humidities from 4% to 50%. Different mathematical models were used to fit the experimental data. The spatially averaged solution of 2D Fickian transient diffusion equation best represented the water mass loss versus time experimental relationship. The dehydration rate constant was found to increase exponentially with air temperature and to decrease exponentially with air relative humidity. PMID:26556000

  5. Synthesis of butenes through 2-butanol dehydration over mesoporous materials produced from ferrierite

    SciTech Connect

    Jeong, Soyeon; Kim, Hyeonjoo; Bae, Jung A.; Kim, Do Heui; Peden, Charles HF; Park, Young-Kwon; Jeon, Jong Ki

    2012-05-20

    Mesoporous materials synthesized from commercial ferrierite (MMZ-FER) were applied to butanol dehydration. The MMZ-FER was produced by disassembling ferrierite into unit structures in the presence of an alkali solution, adding a surfactant as a templating material, followed by hydrothermal treatment. The effect of the alkali/(Si+Al) ratio in the disassembling step on the characteristics of the catalyst and butanol dehydration performance were investigated. The MMZ-FER materials, synthesized in a condition in which the NaOH/(Si + Al) mole ratio in the disassembling step was 0.67 and 1.0, demonstrated similar textural properties to those of MCM-41. Many weak acid sites developed on the MMZ-FER(0.67) and MMZ-FER(1.0) samples, which is attributed to the creation of ferrierite-induced acid sites. The MMZ-FER materials showed excellent catalytic activity, selectivity, and stability during the dehydration of 2-butanol.

  6. Improvement of Freezing Quality of Food by Pre-dehydration with Microwave-Vacuum Drying

    NASA Astrophysics Data System (ADS)

    Hamidi, Nurkholis; Tsuruta, Takaharu

    Partial dehydration by microwave vacuum drying has been applied to tuna, oyster and mackerel prior to freezing in order to reduce quality damages due to freezing and thawing. Samples were dehydrated at pressure of 4kPa and temperature lower than 25°C. Two cooling conditions were tested in the experiment by using the freezing chamber of temperatures -20°C and -80°C. The experimental results showed that decreasing the water content in tuna could lower the freezing point temperature and made the freezing time shorter. It was also found that removing some water was effective to reduce the size of ice crystal and the drip loss in mackerel. After thawing, the pre-dehydrated mackerel showed better microstructure than that frozen without pre-treatment. Furthermore, the sensory tests have been done by a group of panelist for the evaluation on aroma, flavor, and general acceptability of mackerels.

  7. Dehydration of Ions in Voltage-Gated Carbon Nanopores Observed by in Situ NMR.

    PubMed

    Luo, Zhi-Xiang; Xing, Yun-Zhao; Liu, Shubin; Ling, Yan-Chun; Kleinhammes, Alfred; Wu, Yue

    2015-12-17

    Ion transport through nanochannels is of fundamental importance in voltage-gated protein ion channels and energy storage devices. Direct microscopic observations are critical for understanding the intricacy of ionic processes in nanoconfinement. Here we report an in situ nuclear magnetic resonance study of ion hydration in voltage-gated carbon nanopores. Nucleus-independent chemical shift was employed to monitor the ionic processes of NaF aqueous electrolyte in nanopores of carbon supercapacitors. The state of ion hydration was revealed by the chemical shift, which is sensitive to the hydration number. A large energy barrier was observed for ions to enter nanopores smaller than the hydrated ion size. Increasing the gating voltage above 0.4 V overcomes this barrier and brings F(-) into the nanopores without dehydration. Partial dehydration of F(-) occurs only at gating voltage above 0.7 V. No dehydration was observed for Na(+) cations, in agreement with their strong ion hydration. PMID:26629712

  8. Dehydration and acute weight gain in mixed martial arts fighters before competition.

    PubMed

    Jetton, Adam M; Lawrence, Marcus M; Meucci, Marco; Haines, Tracie L; Collier, Scott R; Morris, David M; Utter, Alan C

    2013-05-01

    The purpose of this study was to characterize the magnitude of acute weight gain (AWG) and dehydration in mixed martial arts (MMA) fighters before competition. Urinary measures of hydration status and body mass were determined approximately 24 hours before and then again approximately 2 hours before competition in 40 MMA fighters (mean ± SE, age: 25.2 ± 0.65 years, height: 1.77 ± 0.01 m, body mass: 75.8 ± 1.5 kg). The AWG was defined as the amount of body weight the fighters gained in the approximately 22-hour period between the official weigh-in and the actual competition. On average, the MMA fighters gained 3.40 ± 2.2 kg or 4.4% of their body weight in the approximately 22-hour period before competition. Urine specific gravity significantly decreased (p < 0.001) from 1.028 ± 0.001 to 1.020 ± 0.001 during the approximately 22-hour rehydration period. Results demonstrated that 39% of the MMA fighters presented with a Usg of >1.021 immediately before competition indicating significant or serious dehydration. The MMA fighters undergo significant dehydration and fluctuations in body mass (4.4% avg.) in the 24-hour period before competition. Urinary measures of hydration status indicate that a significant proportion of MMA fighters are not successfully rehydrating before competition and subsequently are competing in a dehydrated state. Weight management guidelines to prevent acute dehydration in MMA fighters are warranted to prevent unnecessary adverse health events secondary to dehydration. PMID:23439336

  9. Effect of dehydration reactions on earthquake nucleation: Stable sliding, slow transients, and unstable slip

    NASA Astrophysics Data System (ADS)

    Brantut, N.; Sulem, J.; Schubnel, A.

    2011-05-01

    We study the influence of metamorphic dehydration reactions on the stability of slip in a one-dimensional, spring-slider model. The equations that govern the evolution of the velocity of sliding block and of pore pressure and temperature inside the slip zone are deduced from the mass and energy balance of the multiphases saturated medium and from the kinetics of the dehydration reaction. Such reactions induce two competing effects: a direct increase in pore pressure because they release fluid and a limit in temperature increase because part of the frictional heat is absorbed in the endothermic reactions. The effect of the chemical reaction on the stability of stationary slip is studied. Dehydration reactions increase the critical stiffness at which the system becomes unstable. Depending on the sign of the perturbations, it is shown that dehydration reactions can either (1) trigger a catastrophic increase of pore pressure at quasi-constant temperature leading to vanishing effective stress or (2) trigger an arrest of the fault. Numerical simulations demonstrate the crucial role of initial pore pressure and temperature in the slip zone prior to the onset of the chemical reaction on the subsequent evolution of the system. For highly pressurized fault zones, in which the creep motion of the fault is stable in absence of dehydration reactions, the onset of the reaction can trigger transient slip events induced by chemical pressurization. The magnitude of such events appears to be proportional to the reaction progress. We conclude that metamorphic dehydration reactions strongly modify the nucleation of unstable slip and are a possible origin for slow slip events in subduction zones.

  10. Integrated analysis of the effects of cold and dehydration on rice metabolites, phytohormones, and gene transcripts.

    PubMed

    Maruyama, Kyonoshin; Urano, Kaoru; Yoshiwara, Kyouko; Morishita, Yoshihiko; Sakurai, Nozomu; Suzuki, Hideyuki; Kojima, Mikiko; Sakakibara, Hitoshi; Shibata, Daisuke; Saito, Kazuki; Shinozaki, Kazuo; Yamaguchi-Shinozaki, Kazuko

    2014-04-01

    Correlations between gene expression and metabolite/phytohormone levels under abiotic stress conditions have been reported for Arabidopsis (Arabidopsis thaliana). However, little is known about these correlations in rice (Oryza sativa 'Nipponbare'), despite its importance as a model monocot. We performed an integrated analysis to clarify the relationships among cold- and dehydration-responsive metabolites, phytohormones, and gene transcription in rice. An integrated analysis of metabolites and gene expression indicated that several genes encoding enzymes involved in starch degradation, sucrose metabolism, and the glyoxylate cycle are up-regulated in rice plants exposed to cold or dehydration and that these changes are correlated with the accumulation of glucose (Glc), fructose, and sucrose. In particular, high expression levels of genes encoding isocitrate lyase and malate synthase in the glyoxylate cycle correlate with increased Glc levels in rice, but not in Arabidopsis, under dehydration conditions, indicating that the regulation of the glyoxylate cycle may be involved in Glc accumulation under dehydration conditions in rice but not Arabidopsis. An integrated analysis of phytohormones and gene transcripts revealed an inverse relationship between abscisic acid (ABA) signaling and cytokinin (CK) signaling under cold and dehydration stresses; these stresses increase ABA signaling and decrease CK signaling. High levels of Oryza sativa 9-cis-epoxycarotenoid dioxygenase transcripts correlate with ABA accumulation, and low levels of Cytochrome P450 (CYP) 735A transcripts correlate with decreased levels of a CK precursor in rice. This reduced expression of CYP735As occurs in rice but not Arabidopsis. Therefore, transcriptional regulation of CYP735As might be involved in regulating CK levels under cold and dehydration conditions in rice but not Arabidopsis. PMID:24515831

  11. Dehydration kinetics of talc and 10 Å phase: Consequences for subduction zone seismicity

    NASA Astrophysics Data System (ADS)

    Chollet, Mélanie; Daniel, Isabelle; Koga, Kenneth T.; Petitgirard, Sylvain; Morard, Guillaume

    2009-06-01

    The process of dehydration embrittlement is usually proposed as an explanation for the presence of intermediate-depth earthquakes in subduction zones. It assumes that the release of water by hydrous mineral breakdown is fast enough to provoke brittle failure. We performed high-pressure, high-temperature, dehydration experiments of talc and 10 Å phase coupled with in situ measurement of reaction kinetics using synchrotron X-ray diffraction. Newly developed, X-ray transparent, pressure-sealed, titanium capsule ensured a closed thermochemical environment. From isothermal kinetics data fitted to the Avrami's equation and from the texture of reaction products, we conclude that dehydration rates of these minerals are limited by diffusion. Predicted minimum rates of fluid release range from 10 - 4 to 9 × 10 - 6 m 3fluid m - 3 rock s - 1 , and are fast enough to provoke hydraulic rupture since Maxwell relaxation rate of rocks relevant of subduction zones are slower than the rate of fluid release. These rates are comparable between talc, 10 Å phase and antigorite also [Perrillat, J.-P., Daniel, I., Koga, K.T., Reynard, B., Cardon, H., Crichton, W.A., 2005. Kinetics of antigorite dehydration: a real-time X-ray diffraction study. Earth Planet. Sci. Lett. 236, 899-913]. Consequently, we suggest that the dehydration of hydrous minerals may eventually be fast enough to trigger the intermediate-depth earthquakes, and that the deepest among intermediate-depth earthquakes may actually locate the limits for dehydration of hydrous minerals in the downgoing lithosphere.

  12. Dehydration kinetics and thermochemistry of selected hydrous phases, and simulated gas release pattern in carbonaceous chondrites

    NASA Technical Reports Server (NTRS)

    Bose, Kunal; Ganguly, J.

    1992-01-01

    As part of our continued program of study on the volatile bearing phases and volatile resource potential of carbonaceous chondrite, results of our experimental studies on the dehydration kinetics of talc as a function of temperature and grain size (50 to 0.5 microns), equilibrium dehydration boundary of talc to 40 kbars, calorimetric study of enthalpy of formation of both natural and synthetic talc as a function of grain size, and preliminary results on the dehydration kinetics of epsomite are reported. In addition, theoretical calculations on the gas release pattern of Murchison meteorite, which is a C2(CM) carbonaceous chondrite, were performed. The kinetic study of talc leads to a dehydration rate constant for 40-50 microns size fraction of k = (3.23 x 10(exp 4))exp(-Q/RT)/min with the activation energy Q = 376 (plus or minus 20) kJ/mole. The dehydration rate was found to increase somewhat with decreasing grain size. The enthalpy of formation of talc from elements was measured to be -5896(10) kJ/mol. There was no measurable effect of grain size on the enthalpy beyond the limits of precision of the calorimetric studies. Also the calorimetric enthalpy of both synthetic and natural talc was found to be essentially the same, within the precision of measurements, although the natural talc had a slightly larger field of stability in our phase equilibrium studies. The high pressure experimental data the dehydration equilibrium of talc (talc = enstatite + coesite + H2O) is in strong disagreement with that calculated from the available thermochemical data, which were constrained to fit the low pressure experimental results. The calculated gas release pattern of Murchison meteorite were in reasonable agreement with that determined by stepwise heating in a gas chromatograph.

  13. Alcohol Dehydration on Monooxo W=O and Dioxo O=W=O Species

    SciTech Connect

    Li, Zhenjun; Smid, Bretislav; Kim, Yu Kwon; Matolin, Vladimir; Kay, Bruce D.; Rousseau, Roger J.; Dohnalek, Zdenek

    2012-08-16

    The dehydration of 1-propanol on nanoporous WO3 films prepared via ballistic deposition at ~20 K has been investigated using temperature programmed desorption, infrared reflection absorption spectroscopy and density functional theory. The as deposited films are extremely efficient in 1-propanol dehydration to propene. This activity is correlated with the presence of dioxo O=W=O groups while monooxo W=O species are shown to be inactive. Annealing of the film induces densification that results in the loss of catalytic activity due to annihilation O=W=O species.

  14. Uranyl p-toluenesulphonate and its crystal hydrates. Synthesis and dehydration-hydration processes

    NASA Astrophysics Data System (ADS)

    Baluev, A. V.; Mityakhina, V. S.; Bogachev, S. V.; Suglobova, I. G.

    2003-01-01

    Lowest hydrates of uranyl p-toluenesulphonate (UPTS) and anhydrous salt were synthesised. The dehydration-hydration processes were studied by thermal gravimetric analysis. It has been established that the hydrate shell of UPTS has a layered structure. The IR spectra of UPTS and its hydrates were recorded. It was found that the IR spectra of UPTS crystal hydrates of the same composition, produced in dehydration-hydration, noticeably differ in the range of water vibrations and are the same in the range corresponding to vibrations of sulphonate groups.

  15. Structural characterization and dehydration kinetics of Kirka inderite mineral: Application of non-isothermal models

    SciTech Connect

    Figen, Aysel Kantuerk; Yilmaz, Muege Sari; Piskin, Sabriye

    2010-06-15

    Coats-Redfern, Arrhenius, Ozawa, Kissinger, and Doyle non-isothermal kinetic models were used to calculate the dynamic kinetic parameters for dehydration reaction of Mg-borate mineral, inderite (Kirka - Turkey) based on thermogravimetric analysis, derivative thermogravimetric analysis and differential thermal analysis. Dehydration experiments were carried out at different heating rates of 2, 5, 10, 15, and 20 deg. C/min in a pure nitrogen atmosphere. Structural and morphological properties have been characterized by X-Ray diffraction, Fourier transform-infrared spectroscopy, Scanning electron microscopy-energy dispersive spectroscopy, and Inductively coupled plasma-optical emission spectroscopy techniques.

  16. Overpressure Caused by the Smectite Dehydration Influences on the triggering of fault slip

    NASA Astrophysics Data System (ADS)

    Lin, Wen-Sheng; Liu, Chen-Wuing; Chang, Han-Yuan

    2015-04-01

    Overpressure, which is pore fluid pressure higher than hydrostatic pressure, is observed in numerous mechanical processes along major faults. Many investigations currently show that the pore fluid pressure has been observed to influence the thrust fault strength and slip behavior and updip limit of the seismogenic zone. Clay dehydration is one key control on overpressure generation under undrained condition in thermal pressurization processes. Increasing pressure and temperature with depth depending on the local geological setting and conditions can cause clay dehydration which has been proposed as an explanation for the generation of overpressure. However, study about the effect of excess pore pressure caused by clay dehydration on the triggering of earthquake is seldom addressed in Taiwan. In fault zones like the Chelungpu Fault, clay minerals are abundant in the fault gouge. Therefore, to quantify the effect of overpressure caused by clay dehydration on the triggering of earthquake under undrained condition, we adopt the chemical thermodynamic model and chemical kinetic model to calculate the amount of water expelled from clay dehydration; derive the three-dimensional governing equation of groundwater flow with clay dehydration varied with pressure and temperature; follow the Coulomb-Mohr frictional failure model of earthquake occurrence to evaluate the influence of the pore pressure on the change of effective Coulomb stress. Finally, development of numerical model to simulate the effect of excess pore pressure caused by clay dehydration on the coulomb failure stress coupled thermal-hydraulic-mechanical-chemical has been performed. Moreover, field application with numerical model to quantify analysis of the effect of overpressure caused by clay dehydration on the triggering of earthquake has been progressed. Coulomb stress increases of ≥0.01 MPa have been shown to be associated with seismicity rate increase and in many cases triggering earthquakes. The results

  17. Associations Between Dehydration, Cognitive Impairment, and Frailty in Older Hospitalized Patients: An Exploratory Study.

    PubMed

    McCrow, Judy; Morton, Margaret; Travers, Catherine; Harvey, Keren; Eeles, Eamonn

    2016-05-01

    HOW TO OBTAIN CONTACT HOURS BY READING THIS ARTICLE INSTRUCTIONS 1.2 contact hours will be awarded by Villanova University College of Nursing upon successful completion of this activity. A contact hour is a unit of measurement that denotes 60 minutes of an organized learning activity. This is a learner-based activity. Villanova University College of Nursing does not require submission of your answers to the quiz. A contact hour certificate will be awarded once you register, pay the registration fee, and complete the evaluation form online at http://goo.gl/gMfXaf. To obtain contact hours you must: 1. Read the article, "Associations Between Dehydration, Cognitive Impairment, and Frailty in Older Hospitalized Patients: An Exploratory Study" found on pages 19-27, carefully noting any tables and other illustrative materials that are included to enhance your knowledge and understanding of the content. Be sure to keep track of the amount of time (number of minutes) you spend reading the article and completing the quiz. 2. Read and answer each question on the quiz. After completing all of the questions, compare your answers to those provided within this issue. If you have incorrect answers, return to the article for further study. 3. Go to the Villanova website listed above to register for contact hour credit. You will be asked to provide your name; contact information; and a VISA, MasterCard, or Discover card number for payment of the $20.00 fee. Once you complete the online evaluation, a certificate will be automatically generated. This activity is valid for continuing education credit until April 30, 2019. CONTACT HOURS This activity is co-provided by Villanova University College of Nursing and SLACK Incorporated. Villanova University College of Nursing is accredited as a provider of continuing nursing education by the American Nurses Credentialing Center's Commission on Accreditation. ACTIVITY OBJECTIVES 1. Describe the incidence of dehydration in older hospitalized

  18. Effect of blanching, dehydration method and temperature on the ascorbic acid, colour, sliminess and other constituents of okra fruit.

    PubMed

    Inyang, U E; Ike, C I

    1998-03-01

    Freshly harvested okra fruits were blanched in boiling water (with or without 0.2% sodium metablsulphite salt) and the effect of this treatment, dehydration methods and temperature on certain characteristics of okra investigated. Blanching resulted in the slight decrease in carbohydrate, fat, ash, colour components, ascorbic acid and viscosity. Besides this initial loss, blanching in sulphite solution led to the retention of more of the colour components and ascorbic acid during dehydration. All dehydrated okra samples had higher contents of carbohydrate, fat and ash but lesser contents of protein and ascorbic acid than fresh okra. Fresh okra fruits, on the other hand, had higher content of the colour pigments and were more viscous than all dehydrated products. Samples blanched prior to dehydration retained more of the colour components but were less viscous than unblanched samples. Vacuum dehydrated samples retained more ascorbic acid, colour pigment and mucilage at each of the dehydration temperatures than those from a hot air oven. High dehydration temperatures had negative effect on the colour, ascorbic acid and viscosity of okra. PMID:9713583

  19. Heat and Mass Transfer Modeling of Apple Slice under Simultaneous Infrared Dry-Blanching and Dehydration Process

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To develop a new simultaneous infrared dry blanching and dehydration process for producing high-quality blanched and partially dehydrated products, apple slices with three different thicknesses, 5, 9, and 13 mm, were heated using infrared for up to 10 min at 4000W/m2 IR intensity. The surface and ce...

  20. The response difference of mitochondria in recalcitrant Antiaris toxicaria axes and orthodox Zea mays embryos to dehydration injury.

    PubMed

    Song, Song-Quan; Tian, Mei-Hua; Kan, Jing; Cheng, Hong-Yan

    2009-07-01

    Long-term preservation of recalcitrant seeds is very difficult because the physiological basis on their desiccation sensitivity is poorly understood. Survival of Antiaris toxicaria axes rapidly decreased and that of immature maize embryos very slowly decreased with dehydration. To understand their different responses to dehydration, we examined the changes in mitochondria activity during dehydration. Although activities of cytochrome (Cyt) c oxidase and malate dehydrogenase of the A. toxicaria axis and maize embryo mitochondria decreased with dehydration, the parameters of maize embryo mitochondria were much higher than those of A. toxicaria, showing that the damage was more severe for the A. toxicaria axis mitochondria than for those of maize embryo. The state I and III respiration of the A. toxicaria axis mitochondria were higher than those of maize embryo, the former rapidly decreased, and the latter slowly decreased with dehydration. The proportion of Cyt c pathway to state III respiration for the A. toxicaria axis mitochondria was low and rapidly decreased with dehydration, and the proportion of alternative oxidase pathway was high and slightly increased with dehydration. In contrast, the proportion of Cyt c pathway for maize embryo mitochondria was high, and that of alternative oxidase pathway was low. Both pathways decreased slowly with dehydration. PMID:19566643

  1. GLYCOL DEHYDRATOR BTEX AND VOC EMISSIONS TESTING RESULTS AT TWO UNITS IN TEXAS AND LOUISIANA - VOLUME II. APPENDICES

    EPA Science Inventory

    The report gives results of the collection of emissions tests data at two triethylene glycol (TEG) units to provide data for comparison to GRI-GLYCalc, a computer program developed to estimate emissions from glycol dehydrators. (NOTE: Glycol dehydrators are used in the natural ga...

  2. GLYCOL DEHYDRATOR BTEX AND VOC EMISSIONS TESTING RESULTS AT TWO UNITS IN TEXAS AND LOUISIANA - VOLUME I. TECHNICAL REPORT

    EPA Science Inventory

    The report gives results of the collection of emissions tests data at two triethylene glycol (TEG) units to provide data for comparison to GRI-GLYCalc, a computer program developed to estimate emissions from glycol dehydrators. (NOTE: Glycol dehydrators are used in the natural ga...

  3. GLYCOL DEHYDRATOR BTEX AND VOC EMISSIONS TESTING RESULTS AT TWO UNITS IN TEXAS AND LOUISIANA VOL. II: APPENDICES

    EPA Science Inventory

    The report gives results of the collection of emissions test data st two triethylene glycol units to provide data for the comparison to GRI-GLYCalc, a computer program developed to estimate emissions from glycol dehydrators. [NOTE: Glycol dehydrators are used in the natural gas i...

  4. GLYCOL DEHYDRATOR BTEX AND VOC EMISSIONS TESTING RESULTS AT TWO UNITS IN TEXAS AND LOUISIANA VOL. I: TECHNICAL REPORT

    EPA Science Inventory

    The report gives results of the collection of emissions tests data at two triethylene glycol units to provide data for comparison to GRI-GLYCalc, a computer program developed to estimate emissions from glycol dehydrators. (NOTE: Glycol dehydrators are used in the natural gas indu...

  5. Drying rate and dehydrin synthesis associated with abscisic acid-induced dehydration tolerance in Spathoglottis plicata orchidaceae protocorms.

    PubMed

    Wang, Xing-Jun; Loh, Chiang-Shiong; Yeoh, Hock-Hin; Sun, Wendell Q

    2002-03-01

    Dehydration tolerance of in vitro orchid protocorms was investigated under controlled drying conditions and after abscisic acid (ABA) pretreatment. Protocorms were obtained by germinating seeds on Murashige and Skoog (MS) medium containing 10% (v/v) coconut water, 2% (w/v) sucrose and 0.8% (w/v) agar, and were dehydrated in relative humidities (RH) ranging from 7% to 93% at 25 degrees C. The critical water content of dehydration tolerance was determined, using the electrolyte leakage method. Drying rate affected the critical water content. Slow drying under high RH conditions achieved the greatest tolerance to dehydration. ABA pretreatment decreased the drying rate of protocorms, and increased dehydration tolerance. Improved tolerance to dehydration after ABA treatment was correlated with the effect of ABA on drying rate of protocorms. When critical water content of protocorms dried under different RH was plotted as a function of actual drying rate, no significant difference in tolerance to dehydration was observed between ABA-treated and control protocorms. ABA pretreatment and dehydration of orchid protocorms induced the synthesis of dehydrin, especially under the slow drying conditions. ABA pretreatment also promoted dry matter accumulation such as carbohydrates and soluble proteins and increased the concentration of K(+) and Na(+) ions in protocorms. The ABA-induced decrease in drying rate was correlated with lower osmotic potential, the enhanced maturity of protocorms and the accumulation of dehydrin in protocorms during pretreatment. PMID:11847254

  6. Energy conservation in fruit dehydrators utilizing recirculation of exhaust air and heat-recovery heat exchangers. Final report

    SciTech Connect

    Groh, J.E.; Thompson, T.L.

    1981-12-01

    Dehydration of fruit in the United States is often done by means of a tunnel dehydrator utilizing large quantities of fossil fuel. Existing dehydrators have been designed to operate with maximum product through-put and with little regard for energy efficiency. By incorporating dampers for air recirculation and thermal energy recovery equipment on the exhaust air, the energy required in dehydration was cut by over 40%, satisfying the original objectives of the program. A commercial dehydrator tunnel was modified by installing a heat recovery heat exchanger and an exhaust air recirculation damper. Another tunnel was equipped with the exhaust air recirculation damper only. A third tunnel was unmodified. These three tunnels of a 24 tunnel facility were equipped with individual natural gas meters to measure energy consumption. The energy consumption of the heat exchanger equipped tunnel normally amounted to approximately 40% of the unmodified tunnel during raisin production.

  7. Tantalum compounds as heterogeneous catalysts for saccharide dehydration to 5-hydroxymethylfurfural.

    PubMed

    Yang, Fengli; Liu, Qishun; Yue, Min; Bai, Xuefang; Du, Yuguang

    2011-04-21

    A new solid acid, based on tantalum hydroxide, was used to catalyze saccharide dehydration into 5-hydroxymethylfurfural (HMF) with high catalytic activity and excellent stability in a water-2-butanol biphasic system. Furthermore, good results were also obtained from Jerusalem artichoke juice with the catalyst under the same conditions. PMID:21369620

  8. Enhancement of the promiscuous aldolase and dehydration activities of 4-oxalocrotonate tautomerase by protein engineering.

    PubMed

    Zandvoort, Ellen; Geertsema, Edzard M; Quax, Wim J; Poelarends, Gerrit J

    2012-06-18

    Double play: The enzyme 4-oxalocrotonate tautomerase (4-OT) catalyzes not only the initial cross-coupling of acetaldehyde and benzaldehyde to yield 3-hydroxy-3-phenylpropanal, but also the subsequent dehydration of this aldol compound to yield cinnamaldehyde as the final product. Mechanism-inspired engineering provided an active site mutant (F50A) with strongly enhanced aldol condensation activity. PMID:22615135

  9. Dehydration hardly slows hopping toads (Rhinella granulosa) from xeric and mesic environments.

    PubMed

    Prates, Ivan; Angilleta, Michael J; Wilson, Robbie S; Niehaus, Amanda C; Navas, Carlos A

    2013-01-01

    The locomotor capacity of amphibians depends strongly on temperature and hydration. Understanding the potential interactions between these variables remains an important challenge because temperature and water availability covary strongly in natural environments. We explored the effects of temperature and hydration on the hopping speeds of Rhinella granulosa, a small toad from the semiarid Caatinga and the Atlantic Rain Forest in Brazil. We asked whether thermal and hydric states interact to determine performance and whether toads from the Caatinga differ from their conspecifics from the Atlantic Forest. Both dehydration and cooling impaired hopping speed, but effects were independent of one another. In comparison to performances of other anurans, the performance of R. granulosa was far less sensitive to dehydration. Consequently, dehydrated members of this species may be able to sustain performance through high body temperatures, which agrees with the exceptional heat tolerance of this species. Surprisingly, toads from both the Caatinga and the Atlantic Forest were relatively insensitive to dehydration. This observation suggests that migration or gene flow between toads from the forest and those from a drier region occurred or that toads from a dry region colonized the forest secondarily. PMID:23799839

  10. Global Analysis of WRKY Genes and Their Response to Dehydration and Salt Stress in Soybean

    PubMed Central

    Song, Hui; Wang, Pengfei; Hou, Lei; Zhao, Shuzhen; Zhao, Chuanzhi; Xia, Han; Li, Pengcheng; Zhang, Ye; Bian, Xiaotong; Wang, Xingjun

    2016-01-01

    WRKY proteins are plant specific transcription factors involved in various developmental and physiological processes, especially in biotic and abiotic stress resistance. Although previous studies suggested that WRKY proteins in soybean (Glycine max var. Williams 82) involved in both abiotic and biotic stress responses, the global information of WRKY proteins in the latest version of soybean genome (Wm82.a2v1) and their response to dehydration and salt stress have not been reported. In this study, we identified 176 GmWRKY proteins from soybean Wm82.a2v1 genome. These proteins could be classified into three groups, namely group I (32 proteins), group II (120 proteins), and group III (24 proteins). Our results showed that most GmWRKY genes were located on Chromosome 6, while chromosome 11, 12, and 20 contained the least number of this gene family. More GmWRKY genes were distributed on the ends of chromosomes to compare with other regions. The cis-acting elements analysis suggested that GmWRKY genes were transcriptionally regulated upon dehydration and salt stress. RNA-seq data analysis indicated that three GmWRKY genes responded negatively to dehydration, and 12 genes positively responded to salt stress at 1, 6, and 12 h, respectively. We confirmed by qRT-PCR that the expression of GmWRKY47 and GmWRKY 58 genes was decreased upon dehydration, and the expression of GmWRKY92, 144 and 165 genes was increased under salt treatment. PMID:26870047

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

    PubMed

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

    2015-06-01

    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. PMID:25965632

  12. 40 CFR 63.765 - Glycol dehydration unit process vent standards.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... directly to the atmosphere may be used on the air emission control equipment installed to comply with... satisfaction, that the total HAP emissions to the atmosphere from the glycol dehydration unit process vent are... demonstrates, to the Administrator's satisfaction, that total emissions to the atmosphere from the...

  13. Water Replacement Hypothesis in Atomic Detail—Factors Determining the Structure of Dehydrated Bilayer Stacks

    PubMed Central

    Golovina, Elena A.; Golovin, Andrey V.; Hoekstra, Folkert A.; Faller, Roland

    2009-01-01

    Abstract According to the water replacement hypothesis, trehalose stabilizes dry membranes by preventing the decrease of spacing between membrane lipids under dehydration. In this study, we use molecular-dynamics simulations to investigate the influence of trehalose on the area per lipid (APL) and related structural properties of dehydrated bilayers in atomic detail. The starting conformation of a palmitoyloleolylphosphatidylcholine lipid bilayer in excess water was been obtained by self-assembly. A series of molecular-dynamics simulations of palmitoyloleolylphosphatidylcholine with different degrees of dehydration (28.5, 11.7, and 5.4 waters per lipid) and different molar trehalose/lipid ratios (<1:1, 1:1, and >1:1) were carried out in the NPT ensemble. Water removal causes the formation of multilamellar “stacks” through periodic boundary conditions. The headgroups reorient from pointing outward to inward with dehydration. This causes changes in the electrostatic interactions between interfaces, resulting in interface interpenetration. Interpenetration creates self-spacing of the bilayers and prevents gel-phase formation. At lower concentrations, trehalose does not separate the interfaces, and acting together with self-spacing, it causes a considerable increase of APL. APL decreases at higher trehalose concentrations when the layer of sugar physically separates the interfaces. When interfaces are separated, the model confirms the water replacement hypothesis. PMID:19619463

  14. 21 CFR 573.400 - Ethoxyquin in certain dehydrated forage crops.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Ethoxyquin in certain dehydrated forage crops. 573.400 Section 573.400 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing §...

  15. 21 CFR 573.400 - Ethoxyquin in certain dehydrated forage crops.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Ethoxyquin in certain dehydrated forage crops. 573.400 Section 573.400 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing §...

  16. Anhydrobiosis in yeast: cell wall mannoproteins are important for yeast Saccharomyces cerevisiae resistance to dehydration.

    PubMed

    Borovikova, Diana; Teparić, Renata; Mrša, Vladimir; Rapoport, Alexander

    2016-08-01

    The state of anhydrobiosis is linked with the reversible delay of metabolism as a result of strong dehydration of cells, and is widely distributed in nature. A number of factors responsible for the maintenance of organisms' viability in these conditions have been revealed. This study was directed to understanding how changes in cell wall structure may influence the resistance of yeasts to dehydration-rehydration. Mutants lacking various cell wall mannoproteins were tested to address this issue. It was revealed that mutants lacking proteins belonging to two structurally and functionally unrelated groups (proteins non-covalently attached to the cell wall, and Pir proteins) possessed significantly lower cell resistance to dehydration-rehydration than the mother wild-type strain. At the same time, the absence of the GPI-anchored cell wall protein Ccw12 unexpectedly resulted in an increase of cell resistance to this treatment; this phenomenon is explained by the compensatory synthesis of chitin. The results clearly indicate that the cell wall structure/composition relates to parameters strongly influencing yeast viability during the processes of dehydration-rehydration, and that damage to cell wall proteins during yeast desiccation can be an important factor leading to cell death. Copyright © 2016 John Wiley & Sons, Ltd. PMID:27510749

  17. A Triple Iron Triathlon Leads to a Decrease in Total Body Mass but Not to Dehydration

    ERIC Educational Resources Information Center

    Knechtle, Beat; Knechtle, Patrizia; Rosemann, Thomas; Oliver, Senn

    2010-01-01

    A loss in total body mass during an ultraendurance performance is usually attributed to dehydration. We identified the changes in total body mass, fat mass, skeletal muscle mass, and selected markers of hydration status in 31 male nonprofessional ultratriathletes participating in a Triple Iron triathlon involving 11.4 km swimming, 540 km cycling…

  18. Recent development in osmotic dehydration of fruit and vegetables: a review.

    PubMed

    Chandra, Suresh; Kumari, Durvesh

    2015-01-01

    Osmotic dehydration of fruits and vegetables is achieved by placing the solid/semi solid, whole or in pieces, in a hypertonic solution (sugar and/or salt) with a simultaneous counter diffusion of solutes from the osmotic solution into the tissues. Osmotic dehydration is recommended as a processing method to obtain better quality of food products. Partial dehydration allows structural, nutritional, sensory, and other functional properties of the raw material to be modified. However, the food industry uptake of osmotic dehydration of foods has not been extensive as expected due to the poor understanding of the counter current flow phenomena associated with it. However, these flows are in a dynamic equilibrium with each other and significantly influence the final product in terms of preservation, nutrition, and organoleptic properties. The demand of healthy, natural, nutritious, and tasty processed food products continuously increases, not only for finished products, but also for ingredient to be included in complex foods such as ice cream, cereals, dairy, confectionaries, and bakery products. PMID:24915357

  19. Dehydration and vernalization treatments identify overlapping molecular networks impacting endodormancy maintenance in leafy spurge crown buds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Leafy spurge (Euphorbia esula L.) is an herbaceous perennial weed that reproduces vegetatively from an abundance of underground adventitious buds (UABs), which undergo well-defined phases of seasonal dormancy (para-, endo- and eco-dormancy). In this study, the effects of dehydration-stress on vegeta...

  20. Dehydration of the Upper Troposphere and Lower Stratosphere by Subvisible Cirrus Clouds Near the Tropical Tropopause

    NASA Technical Reports Server (NTRS)

    Jensen, Eric J.; Toon, Owen B.; Pfister, Leonhard; Selkirk, Henry B.

    1996-01-01

    The extreme dryness of the lower stratosphere is believed to be caused by freeze-drying of air as it enters the stratosphere through the cold tropical tropopause. Previous investigations have been focused on dehydration occurring at the tops of deep convective cloud systems, However, recent observations of a ubiquitous stratiform cirrus cloud layer near the tropical tropopause suggest the possibility of dehydration as air is slowly lifted by large-scale motions, In this study, we have evaluated this possibility using a detailed ice cloud model. Simulations of ice cloud formation in the temperature minima of gravity waves (wave periods of 1 - 2 hours) indicate that large numbers of ice crystals will likely form due to the low temperatures and rapid cooling. As a result, the crystals do not grow larger than about 10 microns, fallspeeds are no greater than a few cm/s, and little or no precipitation or dehydration occurs. However, ice cloud's formed by large-scale vertical motions (with lifetimes of a day or more) should have,fever crystals and more time for crystal sedimentation to occur, resulting in water vapor depletions as large as 1 ppmv near the tropopause. We suggest that gradual lifting near the tropical tropopause, accompanied by formation of thin cirrus, may account for the dehydration.

  1. Exploiting the Genomes of Dehydration/Desiccation-Tolerant Species in Crop Improvement Strategies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An understanding of plant responses to dehydration has important consequences for plant biology in general and direct impacts for agriculture. Over 10% of arable lands are affected by drought, declining average yields for most crops by more than 50%. Thus, improving drought tolerance is a priority a...

  2. Cigarette smoke exposure induces CFTR internalization and insolubility, leading to airway surface liquid dehydration.

    PubMed

    Clunes, Lucy A; Davies, Catrin M; Coakley, Raymond D; Aleksandrov, Andrei A; Henderson, Ashley G; Zeman, Kirby L; Worthington, Erin N; Gentzsch, Martina; Kreda, Silvia M; Cholon, Deborah; Bennett, William D; Riordan, John R; Boucher, Richard C; Tarran, Robert

    2012-02-01

    Cigarette smoke (CS) exposure induces mucus obstruction and the development of chronic bronchitis (CB). While many of these responses are determined genetically, little is known about the effects CS can exert on pulmonary epithelia at the protein level. We, therefore, tested the hypothesis that CS exerts direct effects on the CFTR protein, which could impair airway hydration, leading to the mucus stasis characteristic of both cystic fibrosis and CB. In vivo and in vitro studies demonstrated that CS rapidly decreased CFTR activity, leading to airway surface liquid (ASL) volume depletion (i.e., dehydration). Further studies revealed that CS induced internalization of CFTR. Surprisingly, CS-internalized CFTR did not colocalize with lysosomal proteins. Instead, the bulk of CFTR shifted to a detergent-resistant fraction within the cell and colocalized with the intermediate filament vimentin, suggesting that CS induced CFTR movement into an aggresome-like, perinuclear compartment. To test whether airway dehydration could be reversed, we used hypertonic saline (HS) as an osmolyte to rehydrate ASL. HS restored ASL height in CS-exposed, dehydrated airway cultures. Similarly, inhaled HS restored mucus transport and increased clearance in patients with CB. Thus, we propose that CS exposure rapidly impairs CFTR function by internalizing CFTR, leading to ASL dehydration, which promotes mucus stasis and a failure of mucus clearance, leaving smokers at risk for developing CB. Furthermore, our data suggest that strategies to rehydrate airway surfaces may provide a novel form of therapy for patients with CB. PMID:21990373

  3. Effect of Pulsed Electric Field Pre-Treatment on Osmotic Dehydration of Strawberries

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this research was to study the effect of pulsed electric fields (PEF) as a pre-treatment on osmotic dehydration characteristics and quality of strawberries. The studied PDF treatment conditions included three strengths of electric field (1.0, 2.0, 3.0 Kw/cm) and three numbers of pu...

  4. Multivariate analysis of the sensory changes in the dehydrated cowpea leaves.

    PubMed

    Nyambaka, Hudson; Ryley, Janice

    2004-09-01

    Processing of foods, especially dehydration is known to result in alteration of sensory and nutritional qualities. Cowpea leaves is one of the common leafy vegetables consumed in Kenya that contain high levels of pro-vitamin A compounds and has good carotene retention during processing. A tasting panel was trained using a quantitative descriptive analysis (QDA) test that was developed and used to characterize the sensory properties of dehydrated cowpea leaves. The panel identified sensory attributes in dehydrated cowpea leaves that were important in discriminating the dehydrated samples from the fresh material. Principal component analysis (PCA) was used to analyze the QDA scores. The first principal component (PC1) which accounted for 85% of the variance was an index of the interrelationship among variables in differentiating the samples while PC2, which accounted for the remaining variance measured the attributes influence in discriminating samples. The results of the sensory attributes mean scores showed that aroma, texture and appearance had high influence in discriminating between the fresh, the sun-dried and the solar-dried samples. The solar dried products were close to the fresh material, which was characterized, as soft and tender with an appealing dark green color, than the sun dried product. The sun dried products differed from the other products more on appearance. PMID:18969564

  5. Dehydration, rehydration and overhydration alter patterns of gene expression in the Antarctic midge, Belgica antarctica

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We investigated molecular responses elicited by three types of dehydration (fast, slow and cryoprotective), rehydration and overhydration in larvae of the Antarctic midge, Belgica antarctica. The larvae spend most the year encased in ice but during the austral summer are vulnerable to summer storms,...

  6. 40 CFR 63.765 - Glycol dehydration unit process vent standards.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... directly to the atmosphere may be used on the air emission control equipment installed to comply with... satisfaction, that the total HAP emissions to the atmosphere from the glycol dehydration unit process vent are... demonstrates, to the Administrator's satisfaction, that total emissions to the atmosphere from the...

  7. Polymeric blend nanocomposite membranes for ethanol dehydration-effect of morphology and membrane-solvent interactions

    EPA Science Inventory

    Nanocomposite membranes (NCMs) of sodium alginate/poly(vinyl pyrrolidone) blend polymers incorporated with varying concentrations of phosphotungstic acid (H3PW12O40) (PWA) nanoparticles have been prepared and used in ethanol dehydration by the pervaporation (PV) technique. Effe...

  8. Pervaporation process and use in treating waste stream from glycol dehydrator

    DOEpatents

    Kaschemekat, Jurgen; Baker, Richard W.

    1994-01-01

    Pervaporation processes and apparatus with few moving parts. Ideally, only one pump is used to provide essentially all of the motive power and driving force needed. The process is particularly useful for handling small streams with flow rates less than about 700 gpd. Specifically, the process can be used to treat waste streams from glycol dehydrator regeneration units.

  9. LOW-COST ZEOLITE MEMBRANE MODULES FOR SOLVENT DEHYDRATION - PHASE I

    EPA Science Inventory

    A number of very high-volume liquid chemicals form azeotropes with water and can be dehydrated to required purity levels only through the use of entrainers or drying agents. The handling and disposal of these additional chemicals present significant environmental risk...

  10. Diagenesis and dehydration of subducting oceanic crust within seismogenic subduction zones

    NASA Astrophysics Data System (ADS)

    Kameda, J.; Yamaguchi, A.; Hamada, Y.; Hashimoto, Y.; Kimura, G.

    2012-12-01

    Diagenesis and dehydration of subducting oceanic crust is thought to have strong influence on mechanical and hydrologic properties of seismogenic plate interfaces beneath the accretionary wedges (Kameda et al., 2011). In this work, we analyzed five representative pillow basalts exposed in the ancient accretionary complex, the Shimanto belt in southwest Japan, in order to derive details on a suite of mineral reactions within the subducting oceanic crust. Based on the vitrinite reflectance measurement of terrigenous sediments accompanied by these rocks, they are estimated to have been subjected to burial diagenenesis at 150-300 C. Whole rock and clay-fraction X-ray diffraction (XRD) analyses indicate that sequential saponite to chlorite transformation through mixed-layer phases proceeds under the relatively constant bulk rock composition. Such clay mineral reaction may persist to deep crustal level (~290 C) and contribute to bulk dehydration as a dominant fluid supplier to the plate-boundary fault system. The dehydration may cause abnormal fluid pressurization around the plate-boundary fault zone with a maximum at a certain horizon below the fault (within the intact oceanic crust), resulting in underplating of the upper basement rock into the overriding accretionary prism. Such dehydration-induced weakening process well explains the thickness distribution of the accreted basaltic crust fragments as observed in the onland exposures (Kimura and Ludden, 1995). The breakage of the oceanic crust potentially nucleates seismic slip to propagate along the seismogenic plate interface.

  11. Inactivation of Enterobacter sakazakii of dehydrated infant formula by gamma-irradiation

    NASA Astrophysics Data System (ADS)

    Lee, Ju-Woon; Oh, Sang-Hee; Byun, Eui-Baek; Kim, Jae-Hun; Kim, Jang-Ho; Woon, Jae-Ho; Byun, Myung-Woo

    2007-11-01

    Enterobacter sakazakii has been implicated as a causal organism in a severe form of neonatal meningitis, with reported mortality rates of 20%. The population at greatest risk is immunocompromised infants of any age. Dried infant formula has been identified as a potential source of the organism in both outbreaks and sporadic cases. The objective of this study was to investigate theirradiation effect of the inactivation on E. sakazakii (ATCC 29544) of a dehydrated infant formula. The D10-values were 0.22-0.27 and 0.76 kGy for broth and dehydrated infant formula, respectively. The irradiation at 5.0 kGy was able to completely eliminate the E. sakazakii inoculated at 8.0 to 9.0 log CFU g -1 onto a dehydrated infant formula. There was no regrowth for all samples during the time they were stored at 10 °C for 6 h after rehydration. The present results indicated that a gamma-irradiation could potentially be used to inactivate E. sakazakii in a dehydrated powdered infant formula.

  12. Cavitation in dehydrating xylem of Picea abies: energy properties of ultrasonic emissions reflect tracheid dimensions

    PubMed Central

    Mayr, Stefan; Rosner, Sabine

    2011-01-01

    Ultrasonic emission (UE) testing is used to analyse the vulnerability of xylem to embolism, but the number of UEs often does not sufficiently reflect effects on hydraulic conductivity. We monitored the absolute energy of UE signals in dehydrating xylem samples hypothesizing that (i) conduit diameter is correlated with UE energy and (ii) monitoring of UE energy may enhance the utility of this technique for analysis of xylem vulnerability. Split xylem samples were prepared from trunk wood of Picea abies, and four categories of samples, derived from mature (I: earlywood, II: 30–50% latewood, III: >50% latewood) or juvenile wood (IV: earlywood) were used. Ultrasonic emissions during dehydration were registered and anatomical parameters (tracheid lumen area, number per area) were analysed from cross-sections. Attenuation of UE energy was measured on a dehydrating wood beam by repeated lead breaks. Vulnerability to drought-induced embolism was analysed on dehydrating branches by hydraulic, UE number or UE energy measurements. In split samples, the cumulative number of UEs increased linearly with the number of tracheids per cross-section, and UE energy was positively correlated with the mean lumen area. Ultrasonic emission energies of earlywood samples (I and IV), which showed normally distributed tracheid lumen areas, increased during dehydration, whereas samples with latewood (II and III) exhibited a right-skewed distribution of lumina and UE energies. Ultrasonic emission energy was hardly influenced by moisture content until ~40% moisture loss, and decreased exponentially thereafter. Dehydrating branches showed a 50% loss of conductivity at −3.6 MPa in hydraulic measurements and at −3.9 and −3.5 MPa in UE analysis based on cumulative number or energy of signals, respectively. Ultrasonic emission energy emitted by cavitating conduits is determined by the xylem water potential and by the size of element. Energy patterns during dehydration are thus influenced by

  13. Mild dehydration modifies the cerebrovascular response to the cold pressor test.

    PubMed

    Perry, Blake G; Bear, Tracey L K; Lucas, Samuel J E; Mündel, Toby

    2016-01-01

    The cold pressor test (CPT) is widely used in clinical practice and physiological research. It is characterized by a robust autonomic response, with associated increases in heart rate (HR), mean arterial pressure (MAP) and mean middle cerebral artery blood flow velocity (MCAv(mean)). Hydration status is not commonly reported when conducting this test, yet blood viscosity alone can modulate MCAv(mean), potentially modifying the MCAv(mean) response to the CPT. We investigated the effect of mild dehydration on the physiological response to the CPT in 10 healthy men (mean ± SD: age 28 ± 5 years; body mass 83 ± 5 kg). All participants completed two CPTs, cold water (0°C) immersion of both feet for 90 s, with the order of the euhydration and dehydration trials counterbalanced. Beat-to-beat MCAv, MAP, HR and breath-by-breath partial pressure of end-tidal CO2 (P(ET,CO2)) were measured continuously. Participants' pain perception was measured 1 min into the CPT using a visual analog scale (no pain = 0; maximal pain = 10). Dehydration significantly elevated plasma osmolality and urine specific gravity and reduced body mass (all P < 0.01). The MAP and HR responses were not different between treatments (both P > 0.05). After 90 s of immersion, the change in MCAv(mean) from baseline was less in the dehydration compared with the euhydration trial (change 0 ± 5 versus 7 ± 7 cm s(-1), P = 0.01), as was P(ET,CO2) (change -3 ± 2 versus 0 ± 3 mmHg, P = 0.02). Dehydration was associated with greater relative pain sensation during the CPT (7.0 ± 1.3 vs 5.8 ± 1.8, P = 0.02). Our results demonstrate that mild dehydration can modify the cerebrovascular response to the CPT, with dehydration increasing perceived pain, lowering P ET ,CO2 and, ultimately, blunting the MCAv(mean) response. PMID:26374269

  14. Leaf Shrinkage with Dehydration: Coordination with Hydraulic Vulnerability and Drought Tolerance1[C][W][OPEN

    PubMed Central

    Scoffoni, Christine; Vuong, Christine; Diep, Steven; Cochard, Hervé; Sack, Lawren

    2014-01-01

    Leaf shrinkage with dehydration has attracted attention for over 100 years, especially as it becomes visibly extreme during drought. However, little has been known of its correlation with physiology. Computer simulations of the leaf hydraulic system showed that a reduction of hydraulic conductance of the mesophyll pathways outside the xylem would cause a strong decline of leaf hydraulic conductance (Kleaf). For 14 diverse species, we tested the hypothesis that shrinkage during dehydration (i.e. in whole leaf, cell and airspace thickness, and leaf area) is associated with reduction in Kleaf at declining leaf water potential (Ψleaf). We tested hypotheses for the linkage of leaf shrinkage with structural and physiological water relations parameters, including modulus of elasticity, osmotic pressure at full turgor, turgor loss point (TLP), and cuticular conductance. Species originating from moist habitats showed substantial shrinkage during dehydration before reaching TLP, in contrast with species originating from dry habitats. Across species, the decline of Kleaf with mild dehydration (i.e. the initial slope of the Kleaf versus Ψleaf curve) correlated with the decline of leaf thickness (the slope of the leaf thickness versus Ψleaf curve), as expected based on predictions from computer simulations. Leaf thickness shrinkage before TLP correlated across species with lower modulus of elasticity and with less negative osmotic pressure at full turgor, as did leaf area shrinkage between full turgor and oven desiccation. These findings point to a role for leaf shrinkage in hydraulic decline during mild dehydration, with potential impacts on drought adaptation for cells and leaves, influencing plant ecological distributions. PMID:24306532

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

    PubMed

    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. PMID:26296770

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

    PubMed Central

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

    2015-01-01

    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. PMID:26296770

  17. Cigarette smoke exposure induces CFTR internalization and insolubility, leading to airway surface liquid dehydration

    PubMed Central

    Clunes, Lucy A.; Davies, Catrin M.; Coakley, Raymond D.; Aleksandrov, Andrei A.; Henderson, Ashley G.; Zeman, Kirby L.; Worthington, Erin N.; Gentzsch, Martina; Kreda, Silvia M.; Cholon, Deborah; Bennett, William D.; Riordan, John R.; Boucher, Richard C.; Tarran, Robert

    2012-01-01

    Cigarette smoke (CS) exposure induces mucus obstruction and the development of chronic bronchitis (CB). While many of these responses are determined genetically, little is known about the effects CS can exert on pulmonary epithelia at the protein level. We, therefore, tested the hypothesis that CS exerts direct effects on the CFTR protein, which could impair airway hydration, leading to the mucus stasis characteristic of both cystic fibrosis and CB. In vivo and in vitro studies demonstrated that CS rapidly decreased CFTR activity, leading to airway surface liquid (ASL) volume depletion (i.e., dehydration). Further studies revealed that CS induced internalization of CFTR. Surprisingly, CS-internalized CFTR did not colocalize with lysosomal proteins. Instead, the bulk of CFTR shifted to a detergent-resistant fraction within the cell and colocalized with the intermediate filament vimentin, suggesting that CS induced CFTR movement into an aggresome-like, perinuclear compartment. To test whether airway dehydration could be reversed, we used hypertonic saline (HS) as an osmolyte to rehydrate ASL. HS restored ASL height in CS-exposed, dehydrated airway cultures. Similarly, inhaled HS restored mucus transport and increased clearance in patients with CB. Thus, we propose that CS exposure rapidly impairs CFTR function by internalizing CFTR, leading to ASL dehydration, which promotes mucus stasis and a failure of mucus clearance, leaving smokers at risk for developing CB. Furthermore, our data suggest that strategies to rehydrate airway surfaces may provide a novel form of therapy for patients with CB.—Clunes, L. A., Davies, C. M., Coakley, R. D., Aleksandrov, A. A., Henderson, A. G., Zeman, K. L., Worthington, E. N., Gentzsch, M., Kreda, S. M., Cholon, D., Bennett, W. D., Riordan, J. R., Boucher, R. C., Tarran, R. Cigarette smoke exposure induces CFTR internalization and insolubility, leading to airway surface liquid dehydration. PMID:21990373

  18. Dehydration effects from contrails in a coupled contrail-climate model

    NASA Astrophysics Data System (ADS)

    Schumann, U.; Penner, J. E.; Chen, Yibin; Zhou, Cheng; Graf, K.

    2015-10-01

    The uptake of water by contrails in ice-supersaturated air and the release of water after ice particle advection and sedimentation dehydrates the atmosphere at flight levels and redistributes humidity mainly to lower levels. The dehydration is investigated by coupling a plume-scale contrail model with a global aerosol-climate model. The contrail model simulates all the individual contrails forming from global air traffic for meteorological conditions as defined by the climate model. The computed contrail cirrus properties compare reasonably with theoretical concepts and observations. The mass of water in aged contrails may exceed 106 times the mass of water emitted from aircraft. Many of the ice particles sediment and release water in the troposphere, on average 700 m below the mean flight levels. Simulations with and without coupling are compared. The drying at contrail levels causes thinner and longer-lived contrails with about 15 % reduced contrail radiative forcing (RF). The reduced RF from contrails is on the order of 0.06 W m-2, slightly larger than estimated earlier because of higher soot emissions. For normal traffic, the RF from dehydration is small compared to interannual variability. A case with emissions increased by 100 times is used to overcome statistical uncertainty. The contrails impact the entire hydrological cycle in the atmosphere by reducing the total water column and the cover by high- and low-level clouds. For normal traffic, the dehydration changes contrail RF by positive shortwave and negative longwave contributions on the order of 0.04 W m-2, with a small negative net RF. The total net RF from contrails and dehydration remains within the range of previous estimates.

  19. Dehydration effects from contrails in a coupled contrail-climate model

    NASA Astrophysics Data System (ADS)

    Schumann, U.; Penner, J. E.; Chen, Y.; Zhou, C.; Graf, K.

    2015-07-01

    Uptake of water by contrails in ice-supersaturated air and release of water after ice particle advection and sedimentation dehydrates the atmosphere at flight levels and redistributes humidity mainly to lower levels. The dehydration is investigated by coupling a plume-scale contrail model with a global aerosol-climate model. The contrail model simulates all the individual contrails forming from global air traffic for meteorological conditions as defined by the climate model. The computed contrail-cirrus properties compare reasonably with theoretical concepts and observations. The mass of water in aged contrails may exceed 106 times the mass of water emitted from aircraft. Many of the ice particles sediment and release water in the troposphere, on average 700 m below the mean flight levels. Simulations with and without coupling are compared. The drying at contrail levels causes thinner and longer lived contrails with about 15 % reduced contrail radiative forcing (RF). The reduced RF from contrails is of the order 0.06 W m-2, slightly larger than estimated earlier because of higher soot emissions. For normal traffic, the RF from dehydration is small compared to interannual variability. A case with 100 times increased emissions is used to overcome statistical uncertainty. The contrails impact the entire hydrological cycle in the atmosphere by reducing the total water column and the cover of high and low-level clouds. For normal traffic, the dehydration changes contrail RF by positive shortwave and negative longwave contributions of order 0.04 W m-2, with a small negative net RF. The total net RF from contrails and dehydration remains within the range of previous estimates.

  20. Supine exercise restores arterial blood pressure and skin blood flow despite dehydration and hyperthermia.

    PubMed

    González-Alonso, J; Mora-Rodríguez, R; Coyle, E F

    1999-08-01

    We determined whether the deleterious effects of dehydration and hyperthermia on cardiovascular function during upright exercise were attenuated by elevating central blood volume with supine exercise. Seven trained men [maximal oxygen consumption (VO(2 max)) 4.7 +/- 0. 4 l/min (mean +/- SE)] cycled for 30 min in the heat (35 degrees C) in the upright and in the supine positions (VO(2) 2.93 +/- 0.27 l/min) while maintaining euhydration by fluid ingestion or while being dehydrated by 5% of body weight after 2 h of upright exercise. When subjects were euhydrated, esophageal temperature (T(es)) was 37. 8-38.0 degrees C in both body postures. Dehydration caused equal hyperthermia during both upright and supine exercise (T(es) = 38. 7-38.8 degrees C). During upright exercise, dehydration lowered stroke volume (SV), cardiac output, mean arterial pressure (MAP), and cutaneous vascular conductance and increased heart rate and plasma catecholamines [30 +/- 6 ml, 3.0 +/- 0.7 l/min, 6 +/- 2 mmHg, 22 +/- 8%, 14 +/- 2 beats/min, and 50-96%, respectively; all P < 0. 05]. In contrast, during supine exercise, dehydration did not cause significant alterations in MAP, cutaneous vascular conductance, or plasma catecholamines. Furthermore, supine versus upright exercise attenuated the increases in heart rate (7 +/- 2 vs. 9 +/- 1%) and the reductions in SV (13 +/- 4 vs. 21 +/- 3%) and cardiac output (8 +/- 3 vs. 14 +/- 3%) (all P < 0.05). These results suggest that the decline in cutaneous vascular conductance and the increase in plasma norepinephrine concentration, independent of hyperthermia, are associated with a reduction in central blood volume and a lower arterial blood pressure. PMID:10444482

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

    NASA Astrophysics Data System (ADS)

    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.

  2. Tracking the dehydration process of raw honey by synchronous two-dimensional near infrared correlation spectroscopy

    NASA Astrophysics Data System (ADS)

    Chen, Guiyun; Sun, Xin; Huang, Yuping; Chen, Kunjie

    2014-11-01

    Though much attention is paid to honey quality assessment, few reports on characteristic of manually dehydrated honey have been found. The aim of this investigation is to track the dehydration process of raw honey using synchronous two-dimensional (2D) near infrared correlation spectroscopy. To minimize the impact of dehydration to honey quality, seventy-two honey samples from six different dehydration stages were obtained using drum wind drying method with temperature controlled at 40 °C. Their dynamic short-wave NIR spectra from 600 to 1100 nm were collected in the transmission mode from 10 to 50 °C with an increment of 5 °C and were analyzed using synchronous two-dimensional correlation method. Short-wave NIR spectral data has been exploited less than other NIR region for its weaker signal especially for water absorption's interference with useful information. The investigation enlarged the signal at this band using synchronous 2D correlation analysis, revealing the fingerprinting feature of rape honey and chaste honey during the artificial dehydration process. The results have shown that, with the help of 2D correlation analysis, this band can detect the variation of the second overtone of O-H and N-H groups vibration upon their H-bonds forming or collapsing resulted from the interactions between water and solute. The results have also shown that 2D-NIRS method is able to convert the tiny changes in honey constituents into the detectable fingerprinting difference, which provides a new method for assessing honey quality.

  3. Effect of cation on HTO / H{sub 2}O separation and dehydration characteristics of Y-type zeolite adsorbent

    SciTech Connect

    Iwai, Y.; Uzawa, M.; Yamanishi, T.

    2008-07-15

    Several types of adsorbers have been studied as they are considered for the first stage of water detritiation systems processing more than 100 kg/h of high-level tritiated water generated in a future fusion plant. Zeolite is a suitable adsorbent since it is an inorganic material having a large water capacity. Rapid dehydration characteristics as well as a large HTO/H{sub 2}O separation factor is necessary for the adsorber to minimize its size. Present experiments were focused on the effect of cations on HTO /H{sub 2}O separation and dehydration characteristics of Y-type zeolites. The selected cations are Na, K and Ca. The framework SiO{sub 2}/Al{sub 2}O{sub 3} ratio of the zeolites is fixed to 5.0 in the present experiments. It was found that the isotope separation factors are around 1.1-1.2 under static conditions. As for dehydration, operating temperature fixes the capacity of movable water from the zeolites. The capacity at room temperature is NaY > CaY > KY. HTO dehydration characteristics depend on the accumulated purge gas amount, while the purge gas rate is less influential. Effect of temperature on HTO dehydration is also less influential especially in the early stage of dehydration. Pressure swing is an effective method for HTO dehydration. (authors)

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

    NASA Astrophysics Data System (ADS)

    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.

  5. Accuracy of Inferior Vena Cava Ultrasound for Predicting Dehydration in Children with Acute Diarrhea in Resource-Limited Settings

    PubMed Central

    Modi, Payal; Glavis-Bloom, Justin; Nasrin, Sabiha; Guy, Allysia; Rege, Soham; Noble, Vicki E.; Alam, Nur H.; Levine, Adam C.

    2016-01-01

    Introduction Although dehydration from diarrhea is a leading cause of morbidity and mortality in children under five, existing methods of assessing dehydration status in children have limited accuracy. Objective To assess the accuracy of point-of-care ultrasound measurement of the aorta-to-IVC ratio as a predictor of dehydration in children. Methods A prospective cohort study of children under five years with acute diarrhea was conducted in the rehydration unit of the International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b). Ultrasound measurements of aorta-to-IVC ratio and dehydrated weight were obtained on patient arrival. Percent weight change was monitored during rehydration to classify children as having “some dehydration” with weight change 3–9% or “severe dehydration” with weight change > 9%. Logistic regression analysis and Receiver-Operator Characteristic (ROC) curves were used to evaluate the accuracy of aorta-to-IVC ratio as a predictor of dehydration severity. Results 850 children were enrolled, of which 771 were included in the final analysis. Aorta to IVC ratio was a significant predictor of the percent dehydration in children with acute diarrhea, with each 1-point increase in the aorta to IVC ratio predicting a 1.1% increase in the percent dehydration of the child. However, the area under the ROC curve (0.60), sensitivity (67%), and specificity (49%), for predicting severe dehydration were all poor. Conclusions Point-of-care ultrasound of the aorta-to-IVC ratio was statistically associated with volume status, but was not accurate enough to be used as an independent screening tool for dehydration in children under five years presenting with acute diarrhea in a resource-limited setting. PMID:26766306

  6. Dehydration mediated microRNA response in the African clawed frog Xenopus laevis.

    PubMed

    Wu, Cheng-Wei; Biggar, Kyle K; Storey, Kenneth B

    2013-10-25

    Exposure to various environmental stresses induces metabolic rate depression in many animal species, an adaptation that conserves energy until the environment is again conducive to normal life. The African clawed frog, Xenopus laevis, is periodically subjected to arid summers in South Africa, and utilizes entry into the hypometabolic state of estivation as a mechanism of long term survival. During estivation, frogs must typically deal with substantial dehydration as their ponds dry out and X. laevis can endure >30% loss of its body water. We hypothesize that microRNAs play a vital role in establishing a reversible hypometabolic state and responding to dehydration stress that is associated with amphibian estivation. The present study analyzes the effects of whole body dehydration on microRNA expression in three tissues of X. laevis. Compared to controls, levels of miR-1, miR-125b, and miR-16-1 decreased to 37±6, 64±8, and 80±4% of control levels during dehydration in liver. By contrast, miR-210, miR-34a and miR-21 were significantly elevated by 3.05±0.45, 2.11±0.08, and 1.36±0.05-fold, respectively, in the liver. In kidney tissue, miR-29b, miR-21, and miR-203 were elevated by 1.40±0.09, 1.31±0.05, and 2.17±0.31-fold, respectively, in response to dehydration whereas miR-203 and miR-34a were elevated in ventral skin by 1.35±0.05 and 1.74±0.12-fold, respectively. Bioinformatic analysis of the differentially expressed microRNAs suggests that these are mainly involved in two processes: (1) expression of solute carrier proteins, and (2) regulation of mitogen-activated protein kinase signaling. This study is the first report that shows a tissue specific mode of microRNA expression during amphibian dehydration, providing evidence for microRNAs as crucial regulators of metabolic depression. PMID:23958654

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

    NASA Astrophysics Data System (ADS)

    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

  8. The mechanism of dehydration in chromophore maturation of wild-type green fluorescent protein: A theoretical study

    NASA Astrophysics Data System (ADS)

    Ma, Yingying; Yu, Jian-Guo; Sun, Qiao; Li, Zhen; Smith, Sean C.

    2015-07-01

    An interesting aspect of the green fluorescent protein (GFP) is its autocatalytic chromophore maturation. Numerous experimental studies have indicated that dehydration is the last step in the chromophore maturation process of wild-type GFP. Based on the crystal structure of wild-type GFP, the mechanism of the reverse reaction of dehydration was investigated by using density functional theory (DFT) in this study. Our results proposed that the dehydration is exothermic. Moreover, the rate-limiting step of the mechanism is the proton on guanidinium of Arg96 transferring to the β-carbon anion of Tyr66, which is consistent with the experimental observation.

  9. Effect of Temperature, Time, and Material Thickness on the Dehydration Process of Tomato.

    PubMed

    Correia, A F K; Loro, A C; Zanatta, S; Spoto, M H F; Vieira, T M F S

    2015-01-01

    This study aimed to evaluate the effects of temperature, time, and thickness of tomatoes fruits during adiabatic drying process. Dehydration, a simple and inexpensive process compared to other conservation methods, is widely used in the food industry in order to ensure a long shelf life for the product due to the low water activity. This study aimed to obtain the best processing conditions to avoid losses and keep product quality. Factorial design and surface response methodology were applied to fit predictive mathematical models. In the dehydration of tomatoes through the adiabatic process, temperature, time, and sample thickness, which greatly contribute to the physicochemical and sensory characteristics of the final product, were evaluated. The optimum drying conditions were 60°C with the lowest thickness level and shorter time. PMID:26904666

  10. Earth's interior. Dehydration melting at the top of the lower mantle.

    PubMed

    Schmandt, Brandon; Jacobsen, Steven D; Becker, Thorsten W; Liu, Zhenxian; Dueker, Kenneth G

    2014-06-13

    The high water storage capacity of minerals in Earth's mantle transition zone (410- to 660-kilometer depth) implies the possibility of a deep H2O reservoir, which could cause dehydration melting of vertically flowing mantle. We examined the effects of downwelling from the transition zone into the lower mantle with high-pressure laboratory experiments, numerical modeling, and seismic P-to-S conversions recorded by a dense seismic array in North America. In experiments, the transition of hydrous ringwoodite to perovskite and (Mg,Fe)O produces intergranular melt. Detections of abrupt decreases in seismic velocity where downwelling mantle is inferred are consistent with partial melt below 660 kilometers. These results suggest hydration of a large region of the transition zone and that dehydration melting may act to trap H2O in the transition zone. PMID:24926016

  11. The STF2p Hydrophilin from Saccharomyces cerevisiae Is Required for Dehydration Stress Tolerance

    PubMed Central

    López-Martínez, Gema; Rodríguez-Porrata, Boris; Margalef-Català, Mar; Cordero-Otero, Ricardo

    2012-01-01

    The yeast Saccharomyces cerevisiae is able to overcome cell dehydration; cell metabolic activity is arrested during this period but restarts after rehydration. The yeast genes encoding hydrophilin proteins were characterised to determine their roles in the dehydration-resistant phenotype, and STF2p was found to be a hydrophilin that is essential for survival after the desiccation-rehydration process. Deletion of STF2 promotes the production of reactive oxygen species and apoptotic cell death during stress conditions, whereas the overexpression of STF2, whose gene product localises to the cytoplasm, results in a reduction in ROS production upon oxidative stress as the result of the antioxidant capacity of the STF2p protein. PMID:22442684

  12. Effect of Temperature, Time, and Material Thickness on the Dehydration Process of Tomato

    PubMed Central

    Correia, A. F. K.; Loro, A. C.; Zanatta, S.; Spoto, M. H. F.; Vieira, T. M. F. S.

    2015-01-01

    This study aimed to evaluate the effects of temperature, time, and thickness of tomatoes fruits during adiabatic drying process. Dehydration, a simple and inexpensive process compared to other conservation methods, is widely used in the food industry in order to ensure a long shelf life for the product due to the low water activity. This study aimed to obtain the best processing conditions to avoid losses and keep product quality. Factorial design and surface response methodology were applied to fit predictive mathematical models. In the dehydration of tomatoes through the adiabatic process, temperature, time, and sample thickness, which greatly contribute to the physicochemical and sensory characteristics of the final product, were evaluated. The optimum drying conditions were 60°C with the lowest thickness level and shorter time. PMID:26904666

  13. From dehydration to hyperhidration isotonic and diuretic drinks and hyperhydratant aids in sport.

    PubMed

    Urdampilleta, Aritz; Gómez-Zorita, Saioa

    2014-01-01

    The needs of water and electrolytes are quite variants, depending on age, physiological or environmental conditions. In most long-term sports, usual weight loss of 3-6%, affect in athletic performance. The effects of a 6% dehydration could be improved with individualized diet-specific nutritional strategies and allow only a 2-3% dehydration, which affect metabolic efficiency but will not risk the health. On the contrary, hyperhydration can be dangerous and is associated with hyponatremia that can cause cerebral edema or respiratory failure. Sports drinks should moisturize, providing minerals and carbohydrates and increase the absorption of water by an ideal combination of salts and sugars. Therefore, it is important to provide correct hydration -protocols before, during and after physical activity, as well as know possible limitations of the sport. PMID:24483958

  14. Optimization of hydrous ferrous sulfate dehydration by microwave heating using response surface methodology.

    PubMed

    Yu, Yan-Tao; Liu, Bing-Guo; Chen, Guo; Peng, Jin-Hui; Srinivasakannan, C

    2012-01-01

    The work relates to assessing the ability of the microwave for dehydration of large amount of waste hydrous ferrous sulfate generated from the titanium pigment process industry. The popular process optimization tool of response surface methodology with central composite design was adopted to estimate the effect of dehydration. The process variables were chosen to be power input, duration of heating and the bed thickness, while the response variable being the weight loss. An increase in all the three process variables were found to significantly increase the weight loss, while the effect of interaction among the parameters were found to be insignificant. The optimized process conditions that contribute to the maximum weight loss were identified to be a power input of 960 W, duration of heating of 14 min and bed thickness of 5 cm, resulting in a weight loss of 31.44%. The validity of the optimization process was tested with the repeat runs at optimized conditions. PMID:24432588

  15. [Acceleration of osmotic dehydration process through ohmic heating of foods: raspberries (Rubus idaeus)].

    PubMed

    Simpson, Ricardo R; Jiménez, Maite P; Carevic, Erica G; Grancelli, Romina M

    2007-06-01

    Raspberries (Rubus idaeus) were osmotically dehydrated by applying a conventional method under the supposition of a homogeneous solution, all in a 62% glucose solution at 50 degrees C. Raspberries (Rubus idaeus) were also osmotically dehydrated by using ohmic heating in a 57% glucose solution at a variable voltage (to maintain temperature between 40 and 50 degrees C) and an electric field intensity <100 V/cm. When comparing the results from both experiments it was evident that processing time is reduced when ohmic heating technique was used. In some cases this reduction reached even 50%. This is explained by the additional effect to the thermal damage that is generated in an ohmic process, denominated electroporation. PMID:17992985

  16. Relationship in humans between atrial natriuretic peptide and arginine vasopressin during dehydration

    SciTech Connect

    Burnett, J.C. Jr.; Wilson, D.M.; Kao, P.C.; Schwab, T.R.; Heublein, D.M.; Heser, D.W.

    1986-03-01

    The present study was designed to define in normal humans (n=6) the relationship between atrial natriuretic peptide (ANP) and arginine vasopressin (AVP) during thirty-six hours of dehydration. Atrial natriuretic peptide was measured from extracted plasma by radioimmunoassay to alpha-human atrial natriuretic peptide; arginine vasopressin was measured from platelet free plasma by specific radioimmunoassay to AVP. Determinations were obtained of ANP, AVP and plasma osmolality (Posm) prior to and following fluid deprivation for thirty-six hours. The present study demonstrates that dehydration in humans increases plasma osmolality and arginine vasopressin but does not increase atrial natriuretic peptide. These investigations importantly dissociate these two peptide hormonal systems during the physiologic adaptation to fluid deprivation.

  17. Use of aluminum phosphate as the dehydration catalyst in single step dimethyl ether process

    DOEpatents

    Peng, Xiang-Dong; Parris, Gene E.; Toseland, Bernard A.; Battavio, Paula J.

    1998-01-01

    The present invention pertains to a process for the coproduction of methanol and dimethyl ether (DME) directly from a synthesis gas in a single step (hereafter, the "single step DME process"). In this process, the synthesis gas comprising hydrogen and carbon oxides is contacted with a dual catalyst system comprising a physical mixture of a methanol synthesis catalyst and a methanol dehydration catalyst. The present invention is an improvement to this process for providing an active and stable catalyst system. The improvement comprises the use of an aluminum phosphate based catalyst as the methanol dehydration catalyst. Due to its moderate acidity, such a catalyst avoids the coke formation and catalyst interaction problems associated with the conventional dual catalyst systems taught for the single step DME process.

  18. Chemical heterogeneity in the Hawaiian mantle plume from the alteration and dehydration of recycled oceanic crust

    NASA Astrophysics Data System (ADS)

    Pietruszka, Aaron J.; Norman, Marc D.; Garcia, Michael O.; Marske, Jared P.; Burns, Dale H.

    2013-01-01

    Inter-shield differences in the composition of lavas from Hawaiian volcanoes are generally thought to result from the melting of a heterogeneous mantle source containing variable amounts or types of oceanic crust (sediment, basalt, and/or gabbro) that was recycled into the mantle at an ancient subduction zone. Here we investigate the origin of chemical heterogeneity in the Hawaiian mantle plume by comparing the incompatible trace element abundances of tholeiitic basalts from (1) the three active Hawaiian volcanoes (Kilauea, Mauna Loa, and Loihi) and (2) the extinct Koolau shield (a compositional end member for Hawaiian volcanoes). New model calculations suggest that the mantle sources of Hawaiian volcanoes contain a significant amount of recycled oceanic crust with a factor of ˜2 increase from ˜8-16% at Loihi and Kilauea to ˜15-21% at Mauna Loa and Koolau. We propose that the Hawaiian plume contains a package of recycled oceanic crust (basalt and gabbro, with little or no marine sediment) that was altered by interaction with seawater or hydrothermal fluids prior to being variably dehydrated during subduction. The recycled oceanic crust in the mantle source of Loihi and Kilauea lavas is dominated by the uppermost portion of the residual slab (gabbro-free and strongly dehydrated), whereas the recycled oceanic crust in the mantle source of Mauna Loa and Koolau lavas is dominated by the lowermost portion of the residual slab (gabbro-rich and weakly dehydrated). The present-day distribution of compositional heterogeneities in the Hawaiian plume cannot be described by either a large-scale bilateral asymmetry or radial zonation. Instead, the mantle source of the active Hawaiian volcanoes is probably heterogeneous on a small scale with a NW-SE oriented spatial gradient in the amount, type (i.e., basalt vs. gabbro), and extent of dehydration of the ancient recycled oceanic crust.

  19. A Rare Cause of Retinal Artery Occlusion in Severe Hypernatremic Dehydration in Newborns.

    PubMed

    Ozer, Pinar Altiaylik; Kabatas, Emrah Utku; Kurtul, Bengi Ece; Dilli, Dilek; Zenciroglu, Aysegul; Okumus, Nurullah

    2016-05-01

    Neonatal hypernatremia is an important electrolyte disorder that may have serious complications. It may be a rare and underdiagnosed cause of venous and arterial thrombosis, leading to severe brain damage by cerebral edema and intracranial hemorrhage. Here, the authors present a case of bilateral central retinal artery occlusion in a newborn with severe hypernatremic dehydration who is found to be normal in terms of other causes of retinal arterial thromboembolization. [Ophthalmic Surg Lasers Imaging Retina. 2016;47:482-485.]. PMID:27183555

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

    PubMed

    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. PMID:27386526

  1. Severe dehydration and acute renal failure associated with external ventricular drainage of cerebrospinal fluid in children.

    PubMed

    Simpson, S; Yung, M; Slater, A

    2006-10-01

    We report three paediatric cases of severe dehydration and hyponatraemia with circulatory compromise associated with the use of external ventricular drainage of cerebrospinal fluid. Two of the children had cardiac arrests. All were successfully resuscitated. While there were additional factors that contributed to other fluid losses, and fluid balance data are incomplete, these cases highlight a need for increased vigilance when managing children with external ventricular drains. PMID:17061645

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

    PubMed

    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. PMID:16442280

  3. Development and quality evaluation of dehydrated chicken meat rings using spent hen meat and different extenders.

    PubMed

    Mishra, Bidyut Prava; Chauhan, Geeta; Mendiratta, S K; Sharma, B D; Desai, B A; Rath, P K

    2015-04-01

    It is recommended that for effective utilization of spent hen meat, it should be converted into value added or shelf stable meat products. Since we are lacking in cold chain facilities, therefore there is imperative need to develop shelf stable meat products. The present study was envisaged with the objective to develop dehydrated chicken meat rings utilizing spent hen meat with different extenders. A basic formulation and processing conditions were standardized for dehydrated chicken meat rings. Extenders such as rice flour, barnyard millet flour and texturized soy granule powder at 5, 10 and 15 % levels were incorporated separately replacing the lean meat in pre standardized dehydrated chicken meat ring formulation. On the basis of physico-chemical properties and sensory scores optimum level of incorporation was adjudged as 10 %, 10 % and 5 % for rice flour, barnyard millet flour and texturized soy granule powder respectively. Products with optimum level of extenders were analysed for physico-chemical and sensory attributes. It was found that a good quality dehydrated chicken meat rings can be prepared by utilizing spent hen meat at 90 % level, potato starch 3 % and refined wheat flour 7 % along with spices, condiments, common salt and STPP. Addition of an optimum level of different extenders such as rice flour (10 %), barnyard millet flour (10 %) and TSGP (5 %) separately replacing lean meat in the formulation can give acceptable quality of the product. Rice flour was found to be the best among the three extenders studied as per the sensory evaluation. PMID:25829592

  4. Improved demulsifier chemistry; A novel approach in the dehydration of crude oil

    SciTech Connect

    Staiss, F.; Boehm, R.; Kupfer, R. )

    1991-08-01

    With the ever-growing demand for more efficient dehydration and desalting of crude oil, classic demulsifiers no longer perform satisfactorily in most cases, and new chemical systems are required. This paper describes emulsion breakers, generally polyester amines, and gives detailed laboratory studies of their advantages over classic demulsifiers: more complete migration to the interface, improved emulsion breaking and coalescence, improved effluent water quality, and partial corrosion inhibition. These new demulsifiers combined with classic emulsion breakers have been successfully tested.

  5. Coping with dehydration: sympathetic activation and regulation of glutamatergic transmission in the hypothalamic PVN.

    PubMed

    Bardgett, Megan E; Chen, Qing-Hui; Guo, Qing; Calderon, Alfredo S; Andrade, Mary Ann; Toney, Glenn M

    2014-06-01

    Autonomic and endocrine profiles of chronic hypertension and heart failure resemble those of acute dehydration. Importantly, all of these conditions are associated with exaggerated sympathetic nerve activity (SNA) driven by glutamatergic activation of the hypothalamic paraventricular nucleus (PVN). Here, studies sought to gain insight into mechanisms of disease by determining the role of PVN ionotropic glutamate receptors in supporting SNA and mean arterial pressure (MAP) during dehydration and by elucidating mechanisms regulating receptor activity. Blockade of PVN N-methyl-D-aspartate (NMDA) receptors reduced (P < 0.01) renal SNA and MAP in urethane-chloralose-anesthetized dehydrated (DH) (48 h water deprivation) rats, but had no effect in euhydrated (EH) controls. Blockade of PVN α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors had no effect in either group. NMDA in PVN caused dose-dependent increases of renal SNA and MAP in both groups, but the maximum agonist evoked response (Emax) of the renal SNA response was greater (P < 0.05) in DH rats. The latter was not explained by increased PVN expression of NMDA receptor NR1 subunit protein, increased PVN neuronal excitability, or decreased brain water content. Interestingly, PVN injection of the pan-specific excitatory amino acid transporter (EAAT) inhibitor DL-threo-β-benzyloxyaspartic acid produced smaller sympathoexcitatory and pressor responses in DH rats, which was associated with reduced glial expression of EAAT2 in PVN. Like chronic hypertension and heart failure, dehydration increases excitatory NMDA receptor tone in PVN. Reduced glial-mediated glutamate uptake was identified as a key contributing factor. Defective glutamate uptake in PVN could therefore be an important, but as yet unexplored, mechanism driving sympathetic hyperactivity in chronic cardiovascular diseases. PMID:24671240

  6. Membrane permeation process for dehydration of organic liquid mixtures using sulfonated ion-exchange polyalkene membranes

    DOEpatents

    Cabasso, Israel; Korngold, Emmanuel

    1988-01-01

    A membrane permeation process for dehydrating a mixture of organic liquids, such as alcohols or close boiling, heat sensitive mixtures. The process comprises causing a component of the mixture to selectively sorb into one side of sulfonated ion-exchange polyalkene (e.g., polyethylene) membranes and selectively diffuse or flow therethrough, and then desorbing the component into a gas or liquid phase on the other side of the membranes.

  7. Physiological and Biochemical Responses of Yarrowia lipolytica to Dehydration Induced by Air-Drying and Freezing

    PubMed Central

    Pénicaud, Caroline; Landaud, Sophie; Jamme, Frédéric; Talbot, Pauline; Bouix, Marielle; Ghorbal, Sarrah; Fonseca, Fernanda

    2014-01-01

    Organisms that can withstand anhydrobiosis possess the unique ability to temporarily and reversibly suspend their metabolism for the periods when they live in a dehydrated state. However, the mechanisms underlying the cell’s ability to tolerate dehydration are far from being fully understood. The objective of this study was to highlight, for the first time, the cellular damage to Yarrowia lipolytica as a result of dehydration induced by drying/rehydration and freezing/thawing. Cellular response was evaluated through cell cultivability determined by plate counts, esterase activity and membrane integrity assessed by flow cytometry, and the biochemical composition of cells as determined by FT-IR spectroscopy. The effects of the harvesting time (in the log or stationary phase) and of the addition of a protective molecule, trehalose, were investigated. All freshly harvested cells exhibited esterase activity and no alteration of membrane integrity. Cells freshly harvested in the stationary phase presented spectral contributions suggesting lower nucleic acid content and thicker cell walls, as well as longer lipid chains than cells harvested in the log phase. Moreover, it was found that drying/rehydration induced cell plasma membrane permeabilization, loss of esterase activity with concomitant protein denaturation, wall damage and oxidation of nucleic acids. Plasma membrane permeabilization and loss of esterase activity could be reduced by harvesting in the stationary phase and/or with trehalose addition. Protein denaturation and wall damage could be reduced by harvesting in the stationary phase. In addition, it was shown that measurements of loss of membrane integrity and preservation of esterase activity were suitable indicators of loss and preservation of cultivability, respectively. Conversely, no clear effect of freezing/thawing could be observed, probably because of the favorable operating conditions applied. These results give insights into Y. lipolytica

  8. Localised slip controlled by dehydration embrittlement of partly serpentinised dunites, Leka Ophiolite Complex, Norway

    NASA Astrophysics Data System (ADS)

    Dunkel, Kristina G.; Austrheim, Håkon; Cordonnier, Benoit; Jamtveit, Bjørn

    2016-04-01

    Dehydration of serpentinised ultramafic rocks can increase the pore fluid pressure and induce brittle failure; however the extents of strain localisation and unstable frictional sliding are still under debate. Microstructural and mineralogical evidence from dunites of the Leka Ophiolite Complex in the Central Norwegian Caledonides demonstrates that prograde metamorphism of serpentinite veins led to local fluid production and to the growth of large-grained olivine rich in magnetite inclusions. The epitaxial growth of comparatively Fe-poor prograde olivine on Fe-richer relics of primary olivine caused a high variability in Fe-content, even within single crystals. On a larger scale, the average Fe-content of olivine rises towards the vein edges, which reflects a decrease in the degree of initial serpentinisation towards the host rock. The former distribution of serpentine strongly influenced the mechanical response of the rock to the fluid production during deserpentinisation: The faulting caused by the associated dehydration embrittlement occurred along highly localized slip planes in the centres of the meta-serpentinite veins. Around these slip planes, the prograde olivine experienced significant grain size reduction, but very limited shear strain. The strain concentration on narrow faults, also documented by a sharp offset of chromite layers, and the brittle deformation of the surrounding olivine suggest unstable frictional sliding rather than slower creep. This natural example of deserpentinisation-induced embrittlement illustrates that structural heterogeneities in the form of serpentinite veins have first-order controls on strain localisation and frictional sliding. While strain may be distributed during dehydration of a homogeneous serpentinite, as has been observed in recent experimental studies, it may become strongly localised in a heterogeneous rock volume where fluid pressure is locally increased along pre-existing veins. As most of the oceanic lithosphere

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

    PubMed Central

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

    2016-01-01

    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. PMID:27386526

  10. Unconventional application of the Mitsunobu reaction: Selective flavonolignan dehydration yielding hydnocarpins

    PubMed Central

    Huang, Guozheng; Schramm, Simon; Heilmann, Jörg; Biedermann, David; Křen, Vladimír

    2016-01-01

    Summary Various Mitsunobu conditions were investigated for a series of flavonolignans (silybin A, silybin B, isosilybin A, and silychristin A) to achieve either selective esterification in position C-23 or dehydration in a one-pot reaction yielding the biologically important enantiomers of hydnocarpin D, hydnocarpin and isohydnocarpin, respectively. This represents the only one-pot semi-synthetic method to access these flavonolignans in high yields. PMID:27340458

  11. Unconventional application of the Mitsunobu reaction: Selective flavonolignan dehydration yielding hydnocarpins.

    PubMed

    Huang, Guozheng; Schramm, Simon; Heilmann, Jörg; Biedermann, David; Křen, Vladimír; Decker, Michael

    2016-01-01

    Various Mitsunobu conditions were investigated for a series of flavonolignans (silybin A, silybin B, isosilybin A, and silychristin A) to achieve either selective esterification in position C-23 or dehydration in a one-pot reaction yielding the biologically important enantiomers of hydnocarpin D, hydnocarpin and isohydnocarpin, respectively. This represents the only one-pot semi-synthetic method to access these flavonolignans in high yields. PMID:27340458

  12. Effects of cold and hot temperature on dehydration: a mechanism of cardiovascular burden.

    PubMed

    Lim, Youn-Hee; Park, Min-Seon; Kim, Yoonhee; Kim, Ho; Hong, Yun-Chul

    2015-08-01

    The association between temperature (cold or heat) and cardiovascular mortality has been well documented. However, few studies have investigated the underlying mechanism of the cold or heat effect. The main goal of this study was to examine the effect of temperature on dehydration markers and to explain the pathophysiological disturbances caused by changes of temperature. We investigated the relationship between outdoor temperature and dehydration markers (blood urea nitrogen (BUN)/creatinine ratio, urine specific gravity, plasma tonicity and haematocrit) in 43,549 adults from Seoul, South Korea, during 1995-2008. We used piece-wise linear regression to find the flexion point of apparent temperature and estimate the effects below or above the apparent temperature. Levels of dehydration markers decreased linearly with an increase in the apparent temperature until a point between 22 and 27 °C, which was regarded as the flexion point of apparent temperature, and then increased with apparent temperature. Because the associations between temperature and cardiovascular mortality are known to be U-shaped, our findings suggest that temperature-related changes in hydration status underlie the increased cardiovascular mortality and morbidity during high- or low-temperature conditions. PMID:25344017

  13. Phosphorylated mesoporous carbon as effective catalyst for the selective fructose dehydration to HMF

    SciTech Connect

    Villa, Alberto; Schiavoni, Marco; Fulvio, Pasquale F; Mahurin, Shannon Mark; Dai, Sheng; Mayes, Richard T; Veith, Gabriel M; Prati, Laura

    2013-01-01

    Phosphorylated mesoporous carbons (PMCs) have been synthesized using an already reported one pot methodology. These materials have been applied as acidic catalysts in the dehydration of fructose to hydroxymethylfurfural (HMF). PMCs showed better selectivity to HMF compared to sulfonated carbon catalyst (SC) despite lower activity. The concentration of P-O groups correlates to the activity/selectivity of the catalysts; the higher the P-O concentration the higher the activity. However, the higher the P-O content the lower the selectivity to HMF. Indeed a lower concentration of the P-O groups (and even the acidic groups) minimized the degradation of HMF to levulinic acid and the formation of by-products, such as humines. Stability tests showed that these systems deactivate due to the formation of humines, water insoluble by-products derived from the dehydration of fructose, blocking the active site of the catalyst. Increasing the amount of P-O groups, higher amount of humines are formed; therefore carbons containing lower amount of phosphorylated groups, such as P/N-0.25, are less prone to deactivation. Keywords: Phosphorylated mesoporous carbons; fructose dehydration; HMF

  14. Validation Analysis of a Geriatric Dehydration Screening Tool in Community-Dwelling and Institutionalized Elderly People

    PubMed Central

    Rodrigues, Susana; Silva, Joana; Severo, Milton; Inácio, Cátia; Padrão, Patrícia; Lopes, Carla; Carvalho, Joana; do Carmo, Isabel; Moreira, Pedro

    2015-01-01

    Dehydration is common among elderly people. The aim of this study was to perform validation analysis of a geriatric dehydration-screening tool (DST) in the assessment of hydration status in elderly people. This tool was based on the DST proposed by Vivanti et al., which is composed by 11 items (four physical signs of dehydration and seven questions about thirst sensation, pain and mobility), with four questions extra about drinking habits. The resulting questionnaire was evaluated in a convenience sample comprising institutionalized (n = 29) and community-dwelling (n = 74) elderly people. Urinary parameters were assessed (24-h urine osmolality and volume) and free water reserve (FWR) was calculated. Exploratory factor analysis was used to evaluate the scale’s dimensionality and Cronbach’s alpha was used to measure the reliability of each subscale. Construct’s validity was tested using linear regression to estimate the association between scores in each dimension and urinary parameters. Two factors emerged from factor analysis, which were named “Hydration Score” and “Pain Score”, and both subscales showed acceptable reliabilities. The “Hydration Score” was negatively associated with 24-h urine osmolality in community-dwelling; and the “Pain Score” was negatively associated with 24-h urine osmolality, and positively associated with 24-h urine volume and FWR in institutionalized elderly people. PMID:25739005

  15. Chemical sensor platform for non-invasive monitoring of activity and dehydration.

    PubMed

    Solovei, Dmitry; Žák, Jaromír; Majzlíková, Petra; Sedláček, Jiří; Hubálek, Jaromír

    2015-01-01

    A non-invasive solution for monitoring of the activity and dehydration of organisms is proposed in the work. For this purpose, a wireless standalone chemical sensor platform using two separate measurement techniques has been developed. The first approach for activity monitoring is based on humidity measurement. Our solution uses new humidity sensor based on a nanostructured TiO2 surface for sweat rate monitoring. The second technique is based on monitoring of potassium concentration in urine. High level of potassium concentration denotes clear occurrence of dehydration. Furthermore, a Wireless Body Area Network (WBAN) was developed for this sensor platform to manage data transfer among devices and the internet. The WBAN coordinator controls the sensor devices and collects and stores the measured data. The collected data is particular to individuals and can be shared with physicians, emergency systems or athletes' coaches. Long-time monitoring of activity and potassium concentration in urine can help maintain the appropriate water intake of elderly people or athletes and to send warning signals in the case of near dehydration. The created sensor system was calibrated and tested in laboratory and real conditions as well. The measurement results are discussed. PMID:25594591

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

    PubMed

    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. PMID:26964979

  17. Crystallization, dehydration and preliminary X-ray analysis of excisionase (Xis) proteins cooperatively bound to DNA

    SciTech Connect

    Sam, My D.; Abbani, Mohamad A.; Cascio, Duilio; Johnson, Reid C.; Clubb, Robert T.

    2006-08-01

    This paper describes the crystallization, dehydration and preliminary X-ray data analysis of a complex containing several bacteriophage lambda excisionase (Xis) proteins cooperatively bound to a 33-mer DNA duplex (Xis–DNA{sup X1-X2}). This paper describes the crystallization, dehydration and preliminary X-ray data analysis of a complex containing several bacteriophage lambda excisionase (Xis) [Bushman et al. (1984 ▶). Cell, 39, 699–706] proteins cooperatively bound to a 33-mer DNA duplex (Xis–DNA{sup X1-X2}). Xis is expected to recognize this regulatory element in a novel manner by cooperatively binding and distorting multiple head-to-tail orientated DNA-binding sites. Crystals of this complex belonged to space group P3{sub 1}21 or P3{sub 2}21, with unit-cell parameters a = b = 107.7, c = 73.5 Å, α = β = 90, γ = 120°. Based on the unit-cell parameters for the asymmetric unit, V{sub M} is 3.0 Å{sup 3} Da{sup −1}, which corresponds to a solvent content of ∼59%. The approaches used to crystallize the unusually long DNA fragment in the complex and the dehydration technique applied that dramatically improved the diffraction of the crystals from 10 to 2.6 Å are discussed.

  18. Osmotic and metabolic responses to dehydration and urea-loading in a dormant, terrestrially hibernating frog.

    PubMed

    Muir, Timothy J; Costanzo, Jon P; Lee, Richard E

    2007-11-01

    Physiological responses to dehydration in amphibians are reasonably well documented, although little work has addressed this problem in hibernating animals. We investigated osmotic and metabolic responses to experimental manipulation of hydration state in the wood frog (Rana sylvatica), a terrestrial hibernator that encounters low environmental water potential during autumn and winter. In winter-conditioned frogs, plasma osmolality varied inversely with body water content (range 69-79%, fresh mass) primarily due to increases in sodium and chloride concentrations, as well as accumulation of glucose and urea. Decreased hydration was accompanied by a marked reduction in the resting rate of oxygen consumption, which was inversely correlated with plasma osmolality and urea concentration. In a separate experiment, resting rates of oxygen consumption in fully hydrated frogs receiving injections of saline or saline containing urea did not differ initially; however, upon dehydration, metabolic rates decreased sooner in the urea-loaded frogs than in control frogs. Our findings suggest an important role for urea, acting in concert with dehydration, in the metabolic regulation and energy conservation of hibernating R. sylvatica. PMID:17661060

  19. Support Effects on Bronsted acid site densities and alcohol dehydration turnover rates on tungsten oxide domains

    SciTech Connect

    Macht, Josef; Baertsch, Chelsey D.; May-Lozano, Marcos; Soled, Stuart L.; Wang, Yong; Iglesia, Enrique

    2005-03-01

    Initial activity and acid site density of several WAl, WSi (MCM41) and one WSn sample were determined. Trans/cis 2-butene selectivity is dependent on the support. Presumably, these differences are due to subtle differences in base strengths. 2-Butanol dehydration rates (per W-atom) reached maximum values at intermediate WOx surface densities on WAl, as reported for 2-butanol dehydration reactions on WZr. Titration results indicate that Bronsted acid sites are required for 2-butanol dehydration on WAl, WSi and WSn. UV-visible studies suggest that WAl is much more difficult to reduce than WZr. The detection of reduced centers on WAl, the number of which correlates to Bronsted acid site density and catalyst activity, as well as the temperature dependence of Bronsted acid site density indicate the in-situ formation of these active sites. We infer that this mechanism is common among all supported WOx samples described in this study. Turnover rates are a function of Bronsted acid site density only. High acid site densities lead to high turnover rates. Higher active site densities may cause stronger conjugate bases, as a higher electron density has to be stabilized, and thus weaker acidity, enabling a faster rate of product desorption. The maximum achievable active site density is dependent on the support. WZr reaches a higher active site density than WAl.

  20. Cation regulation by the terrestrial isopod Armadillidium vulgare (Crustacea: Isopoda: Oniscidea) during dehydration in air.

    PubMed

    Koh, Huishan; Wright, Jonathan

    2011-06-01

    Many terrestrial arthropods display tight osmotic and ionic regulation of the hemolymph during dehydration. In this study, we sought to quantify the level of regulation of the major hemolymph cations in the terrestrial isopod Armadillidium vulgare (Isopoda, Oniscidea). Inulin space measurements showed that the hemolymph comprises 52 ± 2.2% of the hydrated water content but contributes 71 ± 9.8% of water losses during desiccation. Hemolymph concentrations of Na+, K+ and Ca²+ were measured in variably dehydrated animals using ion-selective microelectrodes and compared with predicted concentrations assuming no regulation. Na+ and Ca²+ are quite tightly regulated, showing respective concentration increases of 20.8% and 7.1% following a 50% reduction in hemolymph volume, but K+ showed no measurable regulation. The excreted cation fraction during desiccation is negligible. Sites of ion sequestration were examined by injecting ²²Na and ⁴⁵Ca into the hemolymph of hydrated animals and assaying tissue-specific activities following dehydration. Na+ is apparently sequestered non-specifically by an unknown mechanism. Ca²+ accumulates in the dorsal somatic tissues, possibly in the calcium pool of the cuticle. How A. vulgare avoids significant disruptions of E(m) and neuromuscular function in the absence of K+ regulation, and how it sequesters Na+, both pose intriguing challenges for future work. PMID:21335098

  1. Dehydration of lawsonite could directly trigger earthquakes in subducting oceanic crust

    NASA Astrophysics Data System (ADS)

    Okazaki, Keishi; Hirth, Greg

    2016-02-01

    Intermediate-depth earthquakes in cold subduction zones are observed within the subducting oceanic crust, as well as the mantle. In contrast, intermediate-depth earthquakes in hot subduction zones predominantly occur just below the Mohorovičić discontinuity. These observations have stimulated interest in relationships between blueschist-facies metamorphism and seismicity, particularly through dehydration reactions involving the mineral lawsonite. Here we conducted deformation experiments on lawsonite, while monitoring acoustic emissions, in a Griggs-type deformation apparatus. The temperature was increased above the thermal stability of lawsonite, while the sample was deforming, to test whether the lawsonite dehydration reaction induces unstable fault slip. In contrast to similar tests on antigorite, unstable fault slip (that is, stick-slip) occurred during dehydration reactions in the lawsonite and acoustic emission signals were continuously observed. Microstructural observations indicate that strain is highly localized along the fault (R1 and B shears), and that the fault surface develops slickensides (very smooth fault surfaces polished by frictional sliding). The unloading slope during the unstable slip follows the stiffness of the apparatus at all experimental conditions, regardless of the strain rate and temperature ramping rate. A thermomechanical scaling factor for the experiments is within the range estimated for natural subduction zones, indicating the potential for unstable frictional sliding within natural lawsonite layers.

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

    PubMed Central

    Lima de Souza, Alexandre; Divino Ribeiro, Marinaldo; Mattos Negrão, Fagton; Castro, Wanderson José Rodrigues; 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. PMID:27547811

  3. Process optimization for osmo-dehydrated carambola (Averrhoa carambola L) slices and its storage studies.

    PubMed

    Roopa, N; Chauhan, O P; Raju, P S; Das Gupta, D K; Singh, R K R; Bawa, A S

    2014-10-01

    An osmotic-dehydration process protocol for Carambola (Averrhoacarambola L.,), an exotic star shaped tropical fruit, was developed. The process was optimized using Response Surface Methodology (RSM) following Central Composite Rotatable Design (CCRD). The experimental variables selected for the optimization were soak solution concentration (°Brix), soaking temperature (°C) and soaking time (min) with 6 experiments at central point. The effect of process variables was studied on solid gain and water loss during osmotic dehydration process. The data obtained were analyzed employing multiple regression technique to generate suitable mathematical models. Quadratic models were found to fit well (R(2), 95.58 - 98.64 %) in describing the effect of variables on the responses studied. The optimized levels of the process variables were achieved at 70°Brix, 48 °C and 144 min for soak solution concentration, soaking temperature and soaking time, respectively. The predicted and experimental results at optimized levels of variables showed high correlation. The osmo-dehydrated product prepared at optimized conditions showed a shelf-life of 10, 8 and 6 months at 5 °C, ambient (30 ± 2 °C) and 37 °C, respectively. PMID:25328186

  4. Dehydration, skeletal muscle damage and inflammation before the competitions among the elite wrestlers

    PubMed Central

    Ozkan, Isik; Ibrahim, Cicioglu H.

    2016-01-01

    [Purpose] The present study aimed to identify weight-loss and hydration levels before competitions among elite wrestlers and determine the skeletal muscle damage and inflammation levels after dehydration. [Subjects] Seventy-two elite wrestlers who participated in the Turkish Wrestling Championship. [Methods] With the help of specialists, 5 cc of blood were drawn from the forearm veins of the wrestlers. Laboratory analyses of Na+, BUN, Glucose, CK, LDH, AST, ALT, C-RP levels were performed. Using a mathematical formula for hydration the POsm levels of the athletes were calculated. [Results] The wrestlers were divided into two groups based on hydration status. There were significant correlations between hydration indicators of Na+, BUN and PBWL values. There were significant differences between AST, LDH, CK values and skeletal muscle damage indicators of the two groups, but there were no significant differences between the inflammation levels and C-RP values of the groups. [Conclusion] No differences existed in inflammation levels among the wrestlers, although dehydrated wrestlers suffered from higher level of skeletal muscle damage than wrestlers who were not dehydrated. PMID:26957750

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

    PubMed

    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. PMID:27547811

  6. Restoration of fluid balance after exercise-induced dehydration: effects of alcohol consumption.

    PubMed

    Shirreffs, S M; Maughan, R J

    1997-10-01

    The effect of alcohol consumption on the restoration of fluid and electrolyte balance after exercise-induced dehydration [2.01 +/- 0.10% (SD) of body mass] was investigated. Drinks containing 0, 1, 2, and 4% alcohol were consumed over 60 min beginning 30 min after the end of exercise; a different beverage was consumed in each of four trials. The volume consumed (2,212 +/- 153 ml) was equivalent to 150% of body mass loss. Peak urine flow rate occurred later (P = 0.024) with the 4% beverage. The total volume of urine produced over the 6 h after rehydration, although not different between trials (P = 0.307), tended to increase as the quantity of alcohol ingested increased. The increase in blood (P = 0.013) and plasma (P = 0.050) volume with rehydration was slower when the 4% beverage was consumed and did not increase to values significantly greater than the dehydrated level (P = 0.013 and P = 0.050 for blood volume and plasma volume, respectively); generally, the increase was an inverse function of the quantity of alcohol consumed. These results suggest that alcohol has a negligible diuretic effect when consumed in dilute solution after a moderate level of hypohydration induced by exercise in the heat. There appears to be no difference in recovery from dehydration whether the rehydration beverage is alcohol free or contains up to 2% alcohol, but drinks containing 4% alcohol tend to delay the recovery process. PMID:9338423

  7. FROM THE CURRENT LITERATURE: Mechanisms and models of the dehydration self-organization in biological fluids

    NASA Astrophysics Data System (ADS)

    Tarasevich, Yurii Yu

    2004-07-01

    The dehydration self-organization phenomenon in biological fluids attracted the attention of researchers slightly more than a decade ago. While seemingly simple (the structure formation is possible to observe even in domestic conditions), the effect turned out to be extremely complicated and to involve a number of interrelated processes of a different physical nature. The dehydration self-organization effect in biological fluids underlies a medical diagnostic technique patented in 40 countries of the world, while the mechanisms that underlie the technique still remain largely obscure. This review is an attempt to draw an integrated picture of the current state of the problem: to emphasize reliably established facts and the problems that remain to be solved, to put an end to speculation, and to characterize the available theories and models. An analysis of the literature sources allows us to draw the conclusion that the effects observed in the dehydration of biological fluids are typical for colloidal solutions in general and can be described in the framework of conventional physical approaches.

  8. In-vitro terahertz spectroscopy of rat skin under the action of dehydrating agents

    NASA Astrophysics Data System (ADS)

    Kolesnikov, Aleksandr S.; Kolesnikova, Ekaterina A.; Tuchina, Daria K.; Terentyuk, Artem G.; Nazarov, Maxim; Skaptsov, Alexander A.; Shkurinov, Alexander P.; Tuchin, Valery V.

    2014-01-01

    In the paper we present the results of study of rat skin and rat subcutaneous tumor under the action of dehydrating agents in terahertz (THz) range (15-30 THz). Frustrated Total Internal Reflection (FTIR) spectra were obtained with infrared Fourier spectrometer Nicolet 6700 and then they were recalculated in the transmittance spectra with Omnic software. Experiments were carried out with healthy and xenografted tumor in skin tissue in vitro. As the dehydrating agents 100% glycerol, 40%-water glucose solution, PEG-600, and propylene glycol were used. To determine the effect of the optical clearing agent (OCA), the alterations of terahertz transmittance for the samples were analyzed. The results have shown that PEG-600 and 40%-glucose water solution are the most effective dehydrating agent. The transmittance of healthy skin after PEG-600 application increased approximately by 6% and the transmittance of tumor tissue after PEG- 600 and 40%-glucose water solution application increased approximately by 8%. Obtained data can be useful for further application of terahertz radiation for tumor diagnostics.

  9. Investigating structural brain changes of dehydration using voxel-based morphometry.

    PubMed

    Streitbürger, Daniel-Paolo; Möller, Harald E; Tittgemeyer, Marc; Hund-Georgiadis, Margret; Schroeter, Matthias L; Mueller, Karsten

    2012-01-01

    Dehydration can affect the volume of brain structures, which might imply a confound in volumetric and morphometric studies of normal or diseased brain. Six young, healthy volunteers were repeatedly investigated using three-dimensional T(1)-weighted magnetic resonance imaging during states of normal hydration, hyperhydration, and dehydration to assess volume changes in gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF). The datasets were analyzed using voxel-based morphometry (VBM), a widely used voxel-wise statistical analysis tool, FreeSurfer, a fully automated volumetric segmentation measure, and SIENAr a longitudinal brain-change detection algorithm. A significant decrease of GM and WM volume associated with dehydration was found in various brain regions, most prominently, in temporal and sub-gyral parietal areas, in the left inferior orbito-frontal region, and in the extra-nuclear region. Moreover, we found consistent increases in CSF, that is, an expansion of the ventricular system affecting both lateral ventricles, the third, and the fourth ventricle. Similar degrees of shrinkage in WM volume and increase of the ventricular system have been reported in studies of mild cognitive impairment or Alzheimer's disease during disease progression. Based on these findings, a potential confound in GM and WM or ventricular volume studies due to the subjects' hydration state cannot be excluded and should be appropriately addressed in morphometric studies of the brain. PMID:22952926

  10. Dehydration of lawsonite could directly trigger earthquakes in subducting oceanic crust.

    PubMed

    Okazaki, Keishi; Hirth, Greg

    2016-02-01

    Intermediate-depth earthquakes in cold subduction zones are observed within the subducting oceanic crust, as well as the mantle. In contrast, intermediate-depth earthquakes in hot subduction zones predominantly occur just below the Mohorovičić discontinuity. These observations have stimulated interest in relationships between blueschist-facies metamorphism and seismicity, particularly through dehydration reactions involving the mineral lawsonite. Here we conducted deformation experiments on lawsonite, while monitoring acoustic emissions, in a Griggs-type deformation apparatus. The temperature was increased above the thermal stability of lawsonite, while the sample was deforming, to test whether the lawsonite dehydration reaction induces unstable fault slip. In contrast to similar tests on antigorite, unstable fault slip (that is, stick-slip) occurred during dehydration reactions in the lawsonite and acoustic emission signals were continuously observed. Microstructural observations indicate that strain is highly localized along the fault (R1 and B shears), and that the fault surface develops slickensides (very smooth fault surfaces polished by frictional sliding). The unloading slope during the unstable slip follows the stiffness of the apparatus at all experimental conditions, regardless of the strain rate and temperature ramping rate. A thermomechanical scaling factor for the experiments is within the range estimated for natural subduction zones, indicating the potential for unstable frictional sliding within natural lawsonite layers. PMID:26842057

  11. Reduction in plasma vasopressin levels of dehydrated rats following acute stress

    NASA Technical Reports Server (NTRS)

    Keil, L. C.; Severs, W. B.

    1977-01-01

    Results are presented for an investigation directed to substantiate and extend preliminary findings of stress-induced reduction in plasma arginine vasopressin (pAVP). Since normally hydrated rats have very low levels of pAVP, it is difficult to measure reliably any decrease in pAVP that may result from stress. To overcome this problem, the pAVP levels of the tested rats were raised by dehydration prior to application of stress. A radioimmunoassay for pAVP is described and used to determine the levels of vasopressin in the plasma of nondehydrated and dehydrated rats after exposure to ether or acceleration stress. Plasma pAVP is also determined in rats following nicotine administration. It is shown that exposure of nondehydrated rats to ether or acceleration stress does not elicit any significant alterations in circulating pAVP levels while nicotine injections stimulate a marked increase. In particular, ether and acceleration stress produce a rapid reduction in the pAVP level of dehydrated rats, the decrease being observed in both large and small animals. The mechanism for this reduction in pAVP level following stress is yet unknown.

  12. Dehydration and Dehydrogenation of Ethylene Glycol on Rutile TiO2(110)

    SciTech Connect

    Li, Zhenjun; Kay, Bruce D.; Dohnalek, Zdenek

    2013-08-07

    The interactions of ethylene glycol (EG) with partially reduced rutile TiO2(110) surface have been studied using temperature programmed desorption (TPD). The saturation coverage on the surface Ti rows is determined to be 0.43 monolayer (ML), slightly less than one EG per two Ti sites. Most of the adsorbed ethanol (~80%) undergoes further reactions to 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 that of water and hydrogen, respectively. Dehydration dominates at lower EG coverages (< 0.2 ML) and plateaus as the coverage is increased to saturation. Dehydrogenation is observed primarily at higher EG coverages (>0.2 ML). Our results suggest that the observed dehydration and dehydrogenation reactions proceed via different surface intermediates.

  13. Magnetic Resonance Imaging (MRI) of PEM Dehydration and Gas Manifold Flooding During Continuous Fuel Cell Operation

    SciTech Connect

    Minard, Kevin R.; Vishwanathan, Vilanyur V.; Majors, Paul D.; Wang, Li Q.; Rieke, Peter C.

    2006-10-27

    The methods, apparatus, and results are reported for in-situ, near real time, magnetic resonance imaging (MRI) of MEA dehydration and gas manifold flooding in an operating PEM fuel cell. To acquire high-resolution, artifact-free images for visualizing water distribution, acquisition parameters for a standard, two-dimensional (2D), spin-echo sequence were first optimized for the measured magnetic field heterogeneity induced by fuel cell components. 2D images of water inside the fuel cell were then acquired every 128 seconds during 11.4 hours of continuous operation under constant load. Collected images revealed that MEA dehydration proceeded non-uniformly across its plane, starting from gas inlets and ending at gas outlets, and that upon completion of this dehydration process manifold flooding began. To understand these observations, acquired images were correlated to the current output and operating characteristics of the fuel cell. Results demonstrate the power of MRI for in-situ, near real-time imaging of water distribution and non-uniformity in operating PEM fuel cells, and highlight its utility for understanding PEM fuel cell operation, the causes of cell failure, and for developing new strategies of water management.

  14. Reversible Dehydration Behavior Reveals Coordinatively Unsaturated Metal Sites in Microporous Aluminum Phosphonates

    SciTech Connect

    Kinnibrugh, Tiffany L.; Bakhmutov, Vladimir I.; Clearfield, Abraham

    2014-10-01

    Incorporation of the same ligand into three different aluminum phenylenediphosphonates (Al(H2O)(O3PC6H4PO3H) (1), Al-4(H2O)(2)(O3PC6H4PO3)(3) (2), and Al-4(H2O)(4)(O3PC6H4PO3)(2.84)(OH)(0.64) (3)) was accomplished by varying the synthetic conditions. The compounds have different sorption properties; however, all exhibit reversible dehydration behavior. The structures of the hydrated and dehydrated phases were determined from powder X-ray diffraction data. Compounds 2 and 3 were found to be microporous, while compound 1 was found to be nonporous. The stability of the dehydrated phase and the resulting porosity was found to be influenced by the change in the structure upon loss of water.

  15. Effects of cold and hot temperature on dehydration: a mechanism of cardiovascular burden

    NASA Astrophysics Data System (ADS)

    Lim, Youn-Hee; Park, Min-Seon; Kim, Yoonhee; Kim, Ho; Hong, Yun-Chul

    2015-08-01

    The association between temperature (cold or heat) and cardiovascular mortality has been well documented. However, few studies have investigated the underlying mechanism of the cold or heat effect. The main goal of this study was to examine the effect of temperature on dehydration markers and to explain the pathophysiological disturbances caused by changes of temperature. We investigated the relationship between outdoor temperature and dehydration markers (blood urea nitrogen (BUN)/creatinine ratio, urine specific gravity, plasma tonicity and haematocrit) in 43,549 adults from Seoul, South Korea, during 1995-2008. We used piece-wise linear regression to find the flexion point of apparent temperature and estimate the effects below or above the apparent temperature. Levels of dehydration markers decreased linearly with an increase in the apparent temperature until a point between 22 and 27 °C, which was regarded as the flexion point of apparent temperature, and then increased with apparent temperature. Because the associations between temperature and cardiovascular mortality are known to be U-shaped, our findings suggest that temperature-related changes in hydration status underlie the increased cardiovascular mortality and morbidity during high- or low-temperature conditions.

  16. Aquaporins in the antarctic midge, an extremophile that relies on dehydration for cold survival.

    PubMed

    Goto, Shin G; Lee, Richard E; Denlinger, David L

    2015-08-01

    The terrestrial midge Belgica antarctica relies extensively on dehydration to survive the low temperatures and desiccation stress that prevail in its Antarctic habitat. The loss of body water is thus a critical adaptive mechanism employed at the onset of winter to prevent injury from internal ice formation; a rapid mechanism for rehydration is equally essential when summer returns and the larva resumes the brief active phase of its life. This important role for water movement suggests a critical role for aquaporins (AQPs). Recent completion of the genome project on this species revealed the presence of AQPs in B. antarctica representing the DRIP, PRIP, BIB, RPIP, and LHIP families. Treatment with mercuric chloride to block AQPs also blocks water loss, thereby decreasing cell survival at low temperatures. Antibodies directed against mammalian or Drosophila AQPs suggest a wide tissue distribution of AQPs in the midge and changes in protein abundance in response to dehydration, rehydration, and freezing. Thus far, functional studies have been completed only for PRIP1. It appears to be a water-specific AQP, but expression levels are not altered by dehydration or rehydration. Functional assays remain to be completed for the additional AQPs. PMID:26338869

  17. Designing an optimized injection strategy for acid gas disposal without dehydration

    SciTech Connect

    Clark, M.A.; Svrcek, W.Y.; Monnery, W.D.; Jamaluddin, A.K.M.; Bennion, D.B.; Thomas, F.B.; Wichert, E.; Reed, A.E.; Johnson, D.J.

    1998-12-31

    The economics of recovering sulfur from sour natural gas have become unfavorable for small fields. Hydrocarbon producing companies require a cost effective yet environmentally sound alternative method to deal with acid gas. Compressed acid gas reinjection into producing, depleted or non-producing formations has emerged as a viable alternative to traditional sulfur recovery. Most injection schemes include dehydration facilities to remove the saturated water from the gas, preventing corrosion and hydrate formation. An alternative, less costly approach is to keep the water in the vapor phase throughout the injection circuit, eliminating the need to dehydrate. To design an optimized injection strategy, determination of thermodynamic and physical properties such as water content, dewpoint, bubble point, hydrate conditions and density of the acid gas is necessary. Experiments were conducted to determine properties of an acid gas containing a nominal 10% H{sub 2}S with remaining 90% CO{sub 2} and a minor amount of methane. Results indicate that the acid gas can be cooled between compression stages to 40 C (104 F) without entering the two phase region. For an injection pressure of 17,700 kPa (2,567 psia), dehydration is not required to cool the compressed gas to 8 C (46 F) without hydrate formation or corrosion problems. At 9,000 kPa (1,305 psia) the gas can be safely cooled to {minus}2 C (28 F).

  18. Chemical Sensor Platform for Non-Invasive Monitoring of Activity and Dehydration

    PubMed Central

    Solovei, Dmitry; Žák, Jaromír; Majzlíková, Petra; Sedláček, Jiří; Hubálek, Jaromír

    2015-01-01

    A non-invasive solution for monitoring of the activity and dehydration of organisms is proposed in the work. For this purpose, a wireless standalone chemical sensor platform using two separate measurement techniques has been developed. The first approach for activity monitoring is based on humidity measurement. Our solution uses new humidity sensor based on a nanostructured TiO2 surface for sweat rate monitoring. The second technique is based on monitoring of potassium concentration in urine. High level of potassium concentration denotes clear occurrence of dehydration. Furthermore, a Wireless Body Area Network (WBAN) was developed for this sensor platform to manage data transfer among devices and the internet. The WBAN coordinator controls the sensor devices and collects and stores the measured data. The collected data is particular to individuals and can be shared with physicians, emergency systems or athletes' coaches. Long-time monitoring of activity and potassium concentration in urine can help maintain the appropriate water intake of elderly people or athletes and to send warning signals in the case of near dehydration. The created sensor system was calibrated and tested in laboratory and real conditions as well. The measurement results are discussed. PMID:25594591

  19. [THE MODES OF EVALUATION OF TYPE OF DEHYDRATION IN CHILDREN HOSPITALIZED BECAUSE OF ACUTE INTESTINAL INFECTION].

    PubMed

    Krieger, E A; Samodova, O V; Gulakova, N N; Aruiev, A B; Krylova, L A; Titova, L V

    2015-11-01

    Every year about 800,000 cases of intestinal infections end in lethal outcome due to dehydration. The different types of dehydration acquire differential approach to correction. Everywhere there is no application of routine detection of osmolarity of blood plasma under exicosis in children in view of absence of possibility of instrumental measurement. The search of techniques is needed to make it possible to indirectly detect types of dehydration in children hospitalized because of acute intestinal infection with purpose to apply rationale therapy of water-electrolyte disorders. The sampling of 32 patients with intestinal infections accompanied with signs of exicosis degree I-III was examined. The detection of osmolarity of blood was implemented by instrumental technique using gas analyzer ABL 800 Flex (Radiometer; Denmark) and five estimate techniques according to results of biochemical analysis of blood. The differences in precision of measurement of osmolarity of blood plasma by instrumental and estimate techniques were compared using Bland-Altman graphic technique. It is established that formula: 2x[Na+kp] + [glucosekp] (mmol/l) is the most recise. Its application provided results comparable with values detected by instrumental mode. PMID:26999860

  20. Dehydration, skeletal muscle damage and inflammation before the competitions among the elite wrestlers.

    PubMed

    Ozkan, Isik; Ibrahim, Cicioglu H

    2016-01-01

    [Purpose] The present study aimed to identify weight-loss and hydration levels before competitions among elite wrestlers and determine the skeletal muscle damage and inflammation levels after dehydration. [Subjects] Seventy-two elite wrestlers who participated in the Turkish Wrestling Championship. [Methods] With the help of specialists, 5 cc of blood were drawn from the forearm veins of the wrestlers. Laboratory analyses of Na(+), BUN, Glucose, CK, LDH, AST, ALT, C-RP levels were performed. Using a mathematical formula for hydration the POsm levels of the athletes were calculated. [Results] The wrestlers were divided into two groups based on hydration status. There were significant correlations between hydration indicators of Na(+), BUN and PBWL values. There were significant differences between AST, LDH, CK values and skeletal muscle damage indicators of the two groups, but there were no significant differences between the inflammation levels and C-RP values of the groups. [Conclusion] No differences existed in inflammation levels among the wrestlers, although dehydrated wrestlers suffered from higher level of skeletal muscle damage than wrestlers who were not dehydrated. PMID:26957750

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

    NASA Technical Reports Server (NTRS)

    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. Occurrence and Characterization of Cronobacter spp. in Dehydrated Rice Powder from Chinese Supermarket

    PubMed Central

    Huang, Yan; Pang, Yiheng; Wang, Hong; Tang, Zhengzhu; Zhou, Yan; Zhang, Weiyu; Li, Xiugui; Tan, Dongmei; Li, Jian; Lin, Ying; Liu, Xiaoling; Huang, Weiyi; Shi, Yunliang

    2015-01-01

    Cronobacter spp. are emerging food-borne pathogens and have been identified as causative agents of meningitis and necrotizing enterocolitis in infants. Dehydrated rice is popular with a wide range of people and it is frequently used as a substitute for infant milk powder to baby older than four months. The occurrence of Cronobacter spp. was investigated in 1,012 samples of dehydrated rice powder collected from 14 manufacturers in China during 2010 to 2012. The isolates were identified using fusA allele sequencing and subtyped using pulsed-field gel electrophoresis. Seventy-six samples (7.5%) contained Cronobacter spp. The prevalence among manufacturers ranged from 0-28.8%. The 76 isolates included 4 species [Cronobacter sakazakii (52 isolates) Cronobacter malonaticus (14 isolates), Cronobacter dublinensis (7 isolates), and Cronobacter muytjensii (3 isolates)]. Twenty-three unique fusA alleles and sixty-six PFGE-patterns were detected. All isolated strains were observed to be sensitive or to show intermediate susceptibility to eight tested antimicrobial agents. The study revealed serious contamination of dehydrated rice powder by Cronobacter spp., with prevalence varying among manufacturers in China. Identified Cronobacter species, fusA alleles, and subtypes were diverse. PMID:26132635

  3. Effects of Kraft lignin on hydrolysis/dehydration of sugars, cellulosic and lignocellulosic biomass under hot compressed water.

    PubMed

    Daorattanachai, Pornlada; Viriya-empikul, Nawin; Laosiripojana, Navadol; Faungnawakij, Kajornsak

    2013-09-01

    The effect of Kraft lignin presenting on the hydrolysis and dehydration of C5 and C6 sugars, cellulose, hemicelluloses and biomass under hot compressed water (HCW) in the presence of H3PO4 catalyst was intensively studied. The lignin strongly inhibited the acid hydrolysis of cellulose and hemicellulose to glucose and xylose, respectively. Interestingly, the admixed lignin markedly promoted the isomerization of glucose to fructose, and dehydration of fructose (except at the low catalyst loading), resulting in high 5-hydroxymethylfurfural yields. Nonetheless, lignin inhibited the hydrolysis of xylan to xylose and dehydration of xylose to furfural. Moreover, the acidity of the system significantly affects the hydrolysis/dehydration of biomass. It was revealed that the presence of lignin strongly interfered the yields of sugars and furans produced from raw corncob, while the delignified corncob provided significant improvement of product yields, confirming the observed role of lignin in the biomass conversion system via sugar platforms. PMID:23907066

  4. Effect of hydration and dehydration on initiation and dynamics of some physiological reactions in desiccation tolerant cyanobacterium Scytonema geitleri.

    PubMed

    Tiwari, B S; Tripathi, S N

    1998-06-01

    The effect of hydration and dehydration has been studied on extent and recovery of some metabolic reactions in desiccation tolerant terrestrial cyanobacterium Scytonema geitleri. The results show that the energy transducing reactions like photochemical reactions of photosynthesis recover first, followed by increase in ATP pool size. During later phase of hydration, appearance of energy consuming processes such as CO2 fixation and nitrogen fixation have been observed. Sensitivity of reactions during dehydration followed the pattern reverse to recovery processes. PMID:9803667

  5. Using Wind and Temperature Fields to Study Dehydration Mechanisms in the Tropical Tropopause Layer

    NASA Technical Reports Server (NTRS)

    Pittman, Jasna; Miller, Timothy; Robertson, Franklin

    2008-01-01

    The tropics are the main region for troposphere-to-stratosphere transport (TST) of air. One of the dominant mechanisms that control tropical TST of water vapor is freeze-drying by the cold tropical tropopause. This mechanism is supported by evidence from satellite observations of the "tape recorder", where seasonal changes in stratospheric water vapor are in phase with seasonal changes in tropopause temperatures in the tropics. Over the last few years, however, the concept of the tropical tropopause has evolved from a single material surface to a layer called the Tropical Tropopause Layer (TTL). A recent hypothesis on dehydration mechanisms suggests that dehydration and entry point into the stratosphere are not always co-located (Holton and Gettelman, 2001). Instead, dehydration can occur during horizontal advection through Lagrangian 'cold pools', or coldest regions along a parcel's trajectory, as air ascends within the TTL while the entry point into the stratosphere occurs at a different geographical location. In this study, we investigate the impact that these Lagrangian cold pools have on TTL moisture. For this purpose, we use in situ measurements of TTL water vapor obtained aboard NASA's WB-57 aircraft over the Eastern Tropical Pacific, and we compare these measurements to minimum saturation water vapor mixing ratios obtained from three-dimensional backward trajectory calculations. Aircraft measurements show frequent unsaturated conditions, which suggest that the entry value of stratospheric water vapor in this region was not set by local saturation conditions. Trajectory calculations, driven by both ECMWF operational analysis and reanalysis winds and temperature fields, are used to explore the impact (e.g., geographical location, timing, dehydration magnitude) of the Lagrangian cold pools intercepted by the parcels sampled by the aircraft. We find noteworthy differences in the location of the Lagrangian cold pools using the two ECMWF data sets, namely

  6. Dehydration stress-induced oscillations in LEA protein transcripts involves abscisic acid in the moss, Physcomitrella patens.

    PubMed

    Shinde, Suhas; Nurul Islam, M; Ng, Carl K-Y

    2012-07-01

    • Physcomitrella patens is a bryophyte belonging to early diverging lineages of land plants following colonization of land in the Ordovician period. Mosses are typically found in refugial habitats and can experience rapidly fluctuating environmental conditions. The acquisition of dehydration tolerance by bryophytes is of fundamental importance as they lack water-conducting tissues and are generally one cell layer thick. • Here, we show that dehydration induced oscillations in the steady-state transcript abundances of two group 3 late embryogenesis abundant (LEA) protein genes in P. patens protonemata, and that the amplitudes of these oscillations are reflective of the severity of dehydration stress. • Dehydration stress also induced elevations in the concentrations of abscisic acid (ABA), and ABA alone can also induce dosage-dependent oscillatory increases in the steady-state abundance of LEA protein transcripts. Additionally, removal of ABA resulted in rapid attenuation of these oscillatory increases. • Our data demonstrate that dehydration stress-regulated expression of LEA protein genes is temporally dynamic and highlight the importance of oscillations as a robust mechanism for optimal responses. Our results suggest that dehydration stress-induced oscillations in the steady-state abundance of LEA protein transcripts may constitute an important cellular strategy for adaptation to life in a constantly changing environment. PMID:22591374

  7. Investigating the Role of Dehydration Reactions in Subduction Zone Pore Pressures Using Newly-Developed Permeability-Porosity Relationships

    NASA Astrophysics Data System (ADS)

    Screaton, E.; Daigle, H.; James, S.; Meridth, L.; Jaeger, J. M.; Villaseñor, T. G.

    2014-12-01

    Dehydration reactions are linked to shallow subduction zone deformation through excess pore pressures and their effect on mechanical properties. Two reactions, the transformation of smectite to illite and of opal-A to opal-CT and then to quartz, can occur relatively early in the subduction process and may affect the propagation of the plate boundary fault, the updip limit of velocity-weakening frictional paper, and tsunamigenesis. Due to large variations between subduction zones in heat flow, sedimentation rates, and geometries, dehydration location may peak prior to subduction to as much as 100 km landward of the deformation front. The location of the dehydration reaction peak relative to when compaction occurs, causes significant differences in pore pressure generation. As a result, a key element to modeling excess pore pressures due to dehydration reactions is the assumed relationship between permeability and porosity. Data from Integrated Ocean Drilling Program (IODP) drilling of subduction zone reference sites were combined with previously collected results to develop relationships for porosity-permeability behavior for various sediment types. Comparison with measurements of deeper analog data show that porosity-permeability trends are maintained through burial and diagenesis to porosities <10%, suggesting that behavior observed in shallow samples is informative for predicting behavior at depth following subduction. We integrate these permeability-porosity relationships, compaction behavior, predictions of temperature distribution, kinetic expressions for smectite and opal-A dehydration, into fluid flow models to examine the role of dehydration reactions in pore pressure generation.

  8. Photosynthetic parameters of sexually different parts of Porphyra katadai var. hemiphylla (Bangiales, Rhodophyta) during dehydration and re-hydration.

    PubMed

    Lin, A-Peng; Wang, Guang-Ce; Yang, Fang; Pan, Guang-Hua

    2009-03-01

    Physiological data from extreme habitat organisms during stresses are vital information for comprehending their survival. The intertidal seaweeds are exposed to a combination of environmental stresses, the most influential one being regular dehydration and re-hydration. Porphyra katadai var. hemiphylla is a unique intertidal macroalga species with two longitudinally separated, color distinct, sexually different parts. In this study, the photosynthetic performance of both PSI and PSII of the two sexually different parts of P. katadai thalli during dehydration and re-hydration was investigated. Under low-grade dehydration the variation of photosystems of male and female parts of P. katadai were similar. However, after the absolute water content reached 42%, the PSI of the female parts was nearly shut down while that of the male parts still coordinated well and worked properly with PSII. Furthermore, after re-hydration with a better conditioned PSI, the dehydrated male parts were able to restore photosynthesis within 1 h, while the female parts did not. It is concluded that in P. katadai the susceptibility of photosynthesis to dehydration depends on the accommodative ability of PSI. The relatively lower content of phycobiliprotein in male parts may be the cause for a stronger PSI after severe dehydration. PMID:19112580

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

    PubMed

    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 < 0.05). However, cerebral metabolism remained stable through enhanced O2 and glucose extraction (P < 0.05). External carotid artery flow increased for 1 h but declined before exhaustion. Fluid ingestion maintained cerebral and extracranial perfusion throughout nonfatiguing 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 . PMID:26371170

  10. Mechanistic underpinnings of dehydration stress in the American dog tick revealed through RNA-Seq and metabolomics.

    PubMed

    Rosendale, Andrew J; Romick-Rosendale, Lindsey E; Watanabe, Miki; Dunlevy, Megan E; Benoit, Joshua B

    2016-06-15

    Ticks are obligate blood feeders but spend the majority of their lifetime off-host where they must contend with a multitude of environmental stresses. Survival under desiccating conditions is a determinant for habitats where ticks can become established, and water-balance characteristics of ticks have been extensively studied. However, little is known about the underlying aspects associated with dehydration stress in ticks. In this study, we examined the response of male American dog ticks, Dermacentor variabilis, to dehydration using a combined transcriptomics and metabolomics approach. During dehydration, 497 genes were differentially expressed, including an up-regulation of stress-response and protein-catabolism genes and concurrent down-regulation of several energetically expensive biological processes. Accumulation of several metabolites, including specific amino acids, glycerol and gamma aminobutyric acid (GABA), and transcript shifts in the associated pathways for generating these metabolites indicated congruence between changes in the metabolome and gene expression. Ticks treated with exogenous glycerol and GABA demonstrated altered water-balance characteristics; specifically, increased water absorption at high relative humidity. Finally, we observed changes in locomotor activity in response to dehydration, but this change was not influenced by the accumulation of GABA. Overall, the responses to dehydration by these ticks were similar to those observed in other dehydration-tolerant arthropods, but several molecular and behavioral responses are distinct from those associated with other taxa. PMID:27307540

  11. Luminescence induced by dehydration of kaolin - Association with electron-spin-active centers and with surface activity for dehydration-polymerization of glycine

    NASA Technical Reports Server (NTRS)

    Coyne, L.; Hovatter, W.; Sweeney, M.

    1983-01-01

    Experimental data concerning emission of light upon dehydration as a function of preheating and pre-gamma-irradiation are correlated with reported studies of electron-spin resonance (ESR) activity after similar pretreatments. The effect of these pretreatments on the kaolin-promoted incorporation of glycine into peptide oligomers in a wet/cold, hot/dry fluctuating environment is compared to their effect on the ESR and luminescent signals. The existence of spectroscopically active centers appears to be loosely anticorrelated with reaction yield; these yields are increased by increasing the overall energy content of the material. It is concluded that some part of the chemical yield is produced by a mechanism involving intrinsic, excited electronic states of the clay crystal lattice. These states may be derived from thermally, interfacially, and/or mechanically induced charge reorganization within interspersed energy levels in the band structure of the material.

  12. The Effect of Passive Heat Stress and Exercise-Induced Dehydration on the Compensatory Reserve During Simulated Hemorrhage.

    PubMed

    Gagnon, Daniel; Schlader, Zachary J; Adams, Amy; Rivas, Eric; Mulligan, Jane; Grudic, Gregory Z; Convertino, Victor A; Howard, Jeffrey T; Crandall, Craig G

    2016-09-01

    Compensatory reserve represents the proportion of physiological responses engaged to compensate for reductions in central blood volume before the onset of decompensation. We hypothesized that compensatory reserve would be reduced by hyperthermia and exercise-induced dehydration, conditions often encountered on the battlefield. Twenty healthy males volunteered for two separate protocols during which they underwent lower-body negative pressure (LBNP) to hemodynamic decompensation (systolic blood pressure <80 mm Hg). During protocol #1, LBNP was performed following a passive increase in core temperature of ∼1.2°C (HT) or a normothermic time-control period (NT). During protocol #2, LBNP was performed following exercise during which: fluid losses were replaced (hydrated), fluid intake was restricted and exercise ended at the same increase in core temperature as hydrated (isothermic dehydrated), or fluid intake was restricted and exercise duration was the same as hydrated (time-match dehydrated). Compensatory reserve was estimated with the compensatory reserve index (CRI), a machine-learning algorithm that extracts features from continuous photoplethysmograph signals. Prior to LBNP, CRI was reduced by passive heating [NT: 0.87 (SD 0.09) vs. HT: 0.42 (SD 0.19) units, P <0.01] and exercise-induced dehydration [hydrated: 0.67 (SD 0.19) vs. isothermic dehydrated: 0.52 (SD 0.21) vs. time-match dehydrated: 0.47 (SD 0.25) units; P <0.01 vs. hydrated]. During subsequent LBNP, CRI decreased further and its rate of change was similar between conditions. CRI values at decompensation did not differ between conditions. These results suggest that passive heating and exercise-induced dehydration limit the body's physiological reserve to compensate for further reductions in central blood volume. PMID:27183303

  13. Theoretical study of dehydration-carbonation reaction on brucite surface based on ab initio quantum mechanic calculations

    NASA Astrophysics Data System (ADS)

    Churakov, S. V.; Parrinello, M.

    2003-04-01

    The carbonation of brucite (Mg(OH)2) has been considered as a potential technology for cleaning industrial carbon dioxide waste. The kinetics of the reaction Mg(OH)2 + CO2 -> MgCO3 + H2O have been studied experimentally at 573°C by Bearat at al. [1]. Their experiments suggest that the carbonation of magnesium hydroxide proceeds by the reaction Mg(OH)2 -> MgO + H2O followed by the adsorption of CO2 molecules on the dehydrated brucite surface. Due to the large difference in volumes between Mg(OH)2 and MgO, dehydration causes the formation of dislocations and cracks, allowing water molecules to leave the brucite surface and facilitating the advance of the carbonation front in the bulk solid. The detailed mechanism of this process is however unknown. We used the Car-Parrinello ab initio molecular dynamics method to study the structure and dynamics of the (0001), (1-100) and (11-20) surfaces of brucit and calculated the enthalpy and activation barrier of H2O nucleation and dehydration on different surfaces. The results obtained are in agreement with previous studies of brucite dehydration by Masini and Bernasconi [2]. The reactive Car-Parrinello molecular dynamics method [3] has been applied to investigate the detailed mechanism of the dehydration-carbonation reaction at the (1-100) interface of brucite with the gas phase. Based on the results of our MD simulations and the calculated enthalpy of CO2 adsorption on the dehydrated brucite surfaces we propose a mechanism for the dehydration/carbonation reaction. [1] Bearat H, McKelvy MJ, Chizmeshya AVG, Sharma R, Carpenter RW (2002) J. Amer. Ceram. Soc. 85(4):742 [2] Masini P and Bernasconi M (2001) J. Phys. Cond. Mat. 13: 1-12 [3] Iannuzzi M, Laio A and Parrinello M (2003) Phys. Rev. Lett. (submitted)

  14. Transport of Antarctic stratospheric strongly dehydrated air into the troposphere observed during the HALO-ESMVal campaign 2012

    NASA Astrophysics Data System (ADS)

    Rolf, C.; Afchine, A.; Bozem, H.; Buchholz, B.; Ebert, V.; Guggenmoser, T.; Hoor, P.; Konopka, P.; Kretschmer, E.; Müller, S.; Schlager, H.; Spelten, N.; Sumińska-Ebersoldt, O.; Ungermann, J.; Zahn, A.; Krämer, M.

    2015-08-01

    Dehydration in the Antarctic winter stratosphere is a well-known phenomenon that is annually observed by satellites and occasionally observed by balloon-borne measurements. However, in situ measurements of dehydrated air masses in the Antarctic vortex are very rare. Here, we present detailed observations with the in situ and GLORIA remote sensing instrument payload aboard the German aircraft HALO. Strongly dehydrated air masses down to 1.6 ppmv of water vapor were observed as far north as 47° S in an altitude between 12 and 13 km in the lowermost stratosphere. The dehydration can be traced back to individual ice formation events above the Antarctic Peninsula and Plateau, where ice crystals sedimented out and water vapor was irreversibly removed. Within these dehydrated stratospheric air masses, filaments of moister air reaching down to the tropopause are detected with the high-resolution limb sounder, GLORIA. Furthermore, dehydrated air masses are observed with GLORIA in the Antarctic lowermost stratosphere down to 7 km. With the help of a backward trajectory analysis, a midlatitude origin of the moist filaments in the vortex can be identified, while the dry air masses down to 7 km have stratospheric origins. Antarctic stratosphere-troposphere exchange (STE) and transport of dehydrated air masses into the troposphere are investigated. Further, it is shown that the exchange process can be attributed to several successive Rossby wave events in combination with an isentropic exchange of air masses across the thermal tropopause. The transport into the troposphere is caused by air masses that are detached from the potential vorticity (PV) structure by Rossby wave breaking events and subsequently transported diabatically across the dynamical tropopause. Once transported to the troposphere, air masses with stratospheric origin can reach near-surface levels within several days.

  15. Wet fractionation of forage to reduce energy requirements of dehydration. Final technical report, August 12, 1978-April 30, 1982

    SciTech Connect

    Edwards, R.H.; Kohler, G.O.

    1982-07-01

    Wet processing fractionates fresh alfalfa into leaf protein concentrate (LPC), alfalfa solubles, and press cake products. The process can reduce energy consumption compared to normal dehydration of freshly chopped alfalfa by recovering sensible and latent heat from the dryer exhaust gases using a gas recycle system and waste heat evaporator, and by reducing the water evaporated per ton of product produced. A conventional commercial alfalfa dehydration plant (Valley Dehydrating Company, Sterling Co; VDC) was modified to an LPC operation with a design capacity of 30 tons of chopped alfalfa per hour. During the experimental period the plant operated at 15 to 24 tons/h, and produced an average LPC yield of 12.8% (dry basis). The VDC plant consumed 25% less total energy (29% less natural gas; 108% more electrical energy) than that estimated for conventional dehydration of chopped alfalfa. Energy savings were lower than anticipated because of inefficiencies resulting from plant operation at less than design capacity. Based on the experience at VDC, future LPC plants are projected to reduce overall energy consumption by 35% (39% less natural gas; 63% more electrical energy) as compared to conventional dehydration. The VDC products were marketed readily; the press cake was sold to cattle feeders at a price equivalent to dehydrated alfalfa, and the LPC to a broiler producer at prices varying from $430 to $590/ton. Animal performance trials using VDC produced products were highly satisfactory. Projected current cost of a new LPC plant processing 40 tons of chopped alfalfa per hour is 4.7 million dollars; the cost of converting an existing 20 ton/h dehydration plant to a 40 ton/h LPC plant is estimated at 3.6 million dollars. The calculated rate of return on investment for the new plant was 12.0, 26.2 and 40.4% for operating seasons of 130, 180 and 230 days, respectively. Suggestions are made for process improvements and improving process economics.

  16. Elastic wave velocity and acoustic emission monitoring during Gypsum dehydration under triaxial stress conditions

    NASA Astrophysics Data System (ADS)

    Brantut, N.; David, E. C.; Héripré, E.; Schubnel, A. J.; Zimmerman, R. W.; Gueguen, Y.

    2010-12-01

    Dehydration experiments were performed on natural Gypsum polycrystal samples coming from Volterra, Italy in order to study contemporaneously the evolution of P and S elastic wave velocities and acoustic emission (AE) triggering. During these experiments, temperature was slowly raised at 0.15 degrees C per minute under constant stress conditions. Two experiments were realized under quasi-hydrostatic stress (15 and 55 MPa respectively). The third experiment was realized under constant triaxial stress (σ3=45MPa, σ1=75MPa). All three were drained (10MPa constant pore pressure). In each experiments, both P and S wave velocities reduced drastically (as much as approx. 50% in the low confining pressure case) at the onset of dehydration. Importantly, the Vp/Vs ratio also decreased. Shortly after the onset of decrease in P and S wave velocities, the dehydration reaction was also accompanied by bursts of AEs. Time serie locations of the AEs show that they initiated from the pore pressure port, ie from where the pore fluid could easily be drained, and then slowly migrated within the sample. In each experiments, the AE rate could be positively correlated to the reaction rate, inferred from pore volumetry. In such a way, the AE rate reached a peak when the reaction was the fastest. Focal mechanism analysis of the largest AEs showed they had a large volumetric component in compaction, confirming that AEs were indeed related to pore closure and/or collapse. In addition, the AE rate also increased with confinement, ie when a larger amount of compaction was observed. Interestingly, when under differential stress conditions, AE focal mechanisms were mainly in shear. Additional dehydration experiments performed within an environmental scanning electron microscope under low vacuum highlight that, in drained conditions at least, the reaction seems to take place in two phases. First, cracks are being opened along cleavage planes within a single gypsum crystal, which allows for the

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

    NASA Technical Reports Server (NTRS)

    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

  18. The Citrus ABA signalosome: identification and transcriptional regulation during sweet orange fruit ripening and leaf dehydration.

    PubMed

    Romero, Paco; Lafuente, María T; Rodrigo, María J

    2012-08-01

    The abscisic acid (ABA) signalling core in plants include the cytosolic ABA receptors (PYR/PYL/RCARs), the clade-A type 2C protein phosphatases (PP2CAs), and the subclass III SNF1-related protein kinases 2 (SnRK2s). The aim of this work was to identify these ABA perception system components in sweet orange and to determine the influence of endogenous ABA on their transcriptional regulation during fruit development and ripening, taking advantage of the comparative analysis between a wild-type and a fruit-specific ABA-deficient mutant. Transcriptional changes in the ABA signalosome during leaf dehydration were also studied. Six PYR/PYL/RCAR, five PP2CA, and two subclass III SnRK2 genes, homologous to those of Arabidopsis, were identified in the Citrus genome. The high degree of homology and conserved motifs for protein folding and for functional activity suggested that these Citrus proteins are bona fide core elements of ABA perception in orange. Opposite expression patterns of CsPYL4 and CsPYL5 and ABA accumulation were found during ripening, although there were few differences between varieties. In contrast, changes in expression of CsPP2CA genes during ripening paralleled those of ABA content and agreeed with the relevant differences between wild-type and mutant fruit transcript accumulation. CsSnRK2 gene expression continuously decreased with ripening and no remarkable differences were found between cultivars. Overall, dehydration had a minor effect on CsPYR/PYL/RCAR and CsSnRK2 expression in vegetative tissue, whereas CsABI1, CsAHG1, and CsAHG3 were highly induced by water stress. The global results suggest that responsiveness to ABA changes during citrus fruit ripening, and leaf dehydration was higher in the CsPP2CA gene negative regulators than in the other ABA signalosome components. PMID:22888124

  19. Blood pressure is maintained during dehydration by hypothalamic paraventricular nucleus-driven tonic sympathetic nerve activity

    PubMed Central

    Holbein, Walter W; Bardgett, Megan E; Toney, Glenn M

    2014-01-01

    Resting sympathetic nerve activity (SNA) consists primarily of respiratory and cardiac rhythmic bursts of action potentials. During homeostatic challenges such as dehydration, the hypothalamic paraventricular nucleus (PVN) is activated and drives SNA in support of arterial pressure (AP). Given that PVN neurones project to brainstem cardio-respiratory regions that generate bursting patterns of SNA, we sought to determine the contribution of PVN to support of rhythmic bursting of SNA during dehydration and to elucidate which bursts dominantly contribute to maintenance of AP. Euhydrated (EH) and dehydrated (DH) (48 h water deprived) rats were anaesthetized, bilaterally vagotomized and underwent acute PVN inhibition by bilateral injection of the GABA-A receptor agonist muscimol (0.1 nmol in 50 nl). Consistent with previous studies, muscimol had no effect in EH rats (n = 6), but reduced mean AP (MAP; P < 0.001) and integrated splanchnic SNA (sSNA; P < 0.001) in DH rats (n = 6). Arterial pulse pressure was unaffected in both groups. Muscimol reduced burst frequency of phrenic nerve activity (P < 0.05) equally in both groups without affecting the burst amplitude–duration integral (i.e. area under the curve). PVN inhibition did not affect the amplitude of the inspiratory peak, expiratory trough or expiratory peak of sSNA in either group, but reduced cardiac rhythmic sSNA in DH rats only (P < 0.001). The latter was largely reversed by inflating an aortic cuff to restore MAP (n = 5), suggesting that the muscimol-induced reduction of cardiac rhythmic sSNA in DH rats was an indirect effect of reducing MAP and thus arterial baroreceptor input. We conclude that MAP is largely maintained in anaesthetized DH rats by a PVN-driven component of sSNA that is neither respiratory nor cardiac rhythmic. PMID:24973410

  20. Reversion and dehydration reactions of glucose during the dilute sulfuric acid hydrolysis of cellulose

    SciTech Connect

    Helm, R.F.

    1987-01-01

    The inaccessibility of all glycosidic bonds necessitates industrial conversion schemes which employ a dilute acid catalyst at high temperatures. Process conditions also promote further reactions of glucose via the reversion and dehydration pathways. Quantitative determination of the yields of the major reversion and dehydration products is important for understanding and predicting the amounts of these materials expected under envisioned industrial operating conditions. Microcrystalline cellulose (Avicel) was hydrolyzed with sulfuric acid (0.0-1.25 wt.%), at high temperatures (160-250/sup 0/C), and at a 3:1 liquid-to-solid ratio. The hydrolysis was monitored by evaluating the amount of cellulose remaining and the yields of glucose, solid humin, levulinic acid, formic acid, hydroxymethylfurfural (HMF), and reversion products as a function of the aforementioned reaction conditions. Analysis of the reversion products required the development of a technique for the quantitation of trace carbohydrates in complex mixtures and led to the development of a reduction/permethylation gas chromatographic procedure. Cellulose hydrolysis followed pseudo-homogeneous first-order kinetics. Glucose yield was adequately described as consecutive first-order reactions. Anhydrosugars formed via reversion followed equilibrium reaction kinetics whereas the disaccharides did not. Total reversion product yields approached 10% at 250/sup 0/C. Quantitative determination of the major dehydration products provided important information concerning the destruction of glucose. HMF was produced in up to 12% yields based on the theoretical amount of glucose available, and furfural was detected in up to 5% yields. A carbon mass balance based on the determined product yields revealed that approximately 90% of all carbon was accounted for at maximum glucose yields.

  1. Infrared spectroscopic characterization of dehydration and accompanying phase transition behaviors in NAT-topology zeolites

    SciTech Connect

    Wang, Hsiu-Wen; Bishop, David

    2012-01-01

    Relative humidity (PH2O, partial pressure of water)-dependent dehydration and accompanying phase transitions in NAT-topology zeolites (natrolite, scolecite, and mesolite) were studied under controlled temperature and known PH2O conditions by in situ diffuse-reflectance infrared Fourier transform spectroscopy and parallel X-ray powder diffraction. Dehydration was characterized by the disappearance of internal H2O vibrational modes. The loss of H2O molecules caused a sequence of structural transitions in which the host framework transformation path was coupled primarily via the thermal motion of guest Na?/Ca2? cations and H2O molecules. The observation of different interactions of H2O molecules and Na?/Ca2? cations with host aluminosilicate frameworks under highand low-PH2O conditions indicated the development of different local strain fields, arising from cation H2O interactions in NAT-type channels. These strain fields influence the Si O/Al O bond strength and tilting angles within and between tetrahedra as the dehydration temperature is approached. The newly observed infrared bands (at 2,139 cm-1 in natrolite, 2,276 cm-1 in scolecite, and 2,176 and 2,259 cm-1 in mesolite) result from strong cation H2O Al Si framework interactions in NAT-type channels, and these bands can be used to evaluate the energetic evolution of Na?/Ca2? cations before and after phase transitions, especially for scolecite and mesolite. The 2,176 and 2,259 cm-1 absorption bands in mesolite also appear to be related to Na?/Ca2? order disorder that occur when mesolite loses its Ow4 H2O molecules.

  2. A reliable, practical, and economical protocol for inducing diarrhea and severe dehydration in the neonatal calf.

    PubMed Central

    Walker, P G; Constable, P D; Morin, D E; Drackley, J K; Foreman, J H; Thurmon, J C

    1998-01-01

    Fifteen healthy, colostrum-fed, male dairy calves, aged 2 to 7 d were used in a study to develop a diarrhea protocol for neonatal calves that is reliable, practical, and economical. After instrumentation and recording baseline data, diarrhea and dehydration were induced by administering milk replacer [16.5 mL/kg of body weight (BW), PO], sucrose (2 g/kg in a 20% aqueous solution, p.o.), spironolactone and hydrochlorothiazide (1 mg/kg, PO) every 8 h, and furosemide (2 mg/kg, i.m., q6h). Calves were administered sucrose and diuretic agents for 48 h to induce diarrhea and severe dehydration. Clinical changes after 48 h were severe watery diarrhea, severe depression, and marked dehydration (mean, 14% BW loss). Cardiac output, stroke volume, mean central venous pressure, plasma volume, thiocyanate space, blood pH and bicarbonate concentration, base excess, serum chloride concentration, and fetlock temperature were decreased. Plasma lactate concentration, hematocrit, and serum potassium, creatinine, phosphorus, total protein and albumin concentrations were increased. This non-infectious calf diarrhea protocol has a 100% response rate, while providing a consistent and predictable hypovolemic state with diarrhea that reflects most of the clinicopathologic changes observed in osmotic/maldigestive diarrhea caused by infection with rotavirus, coronavirus or cryptosporidia. Limitations of the protocol, when compared to infectious diarrhea models, include failure to induce a severe metabolic acidosis, absence of hyponatremia, renal instead of enteric loss of chloride, renal as well as enteric loss of free water, absence of profound clinical depression and suspected differences in the morphologic and functional effect on intestinal epithelium. Despite these differences, the sucrose/diuretic protocol should be useful in the initial screening of new treatment modalities for calf diarrhea. To confirm their efficacy, the most effective treatment methods should then be examined in

  3. Vapor Phase Dehydration of Glycerol to Acrolein Over SBA-15 Supported Vanadium Substituted Phosphomolybdic Acid Catalyst.

    PubMed

    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. PMID:26373149

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

    SciTech Connect

    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.

  5. Hydration-dehydration interactions between glycine and anhydrous salts: Implications for a chemical evolution of life

    NASA Astrophysics Data System (ADS)

    Kitadai, Norio; Yokoyama, Tadashi; Nakashima, Satoru

    2011-11-01

    Polymerizations of organic monomers including amino acids, nucleotides and monosaccharides are essential processes for chemical evolution of life. Since these reactions proceed with "dehydration" reactions, they are possibly promoted if combined with thermodynamically favorable "hydration" reactions of minerals and salts. To test the possibility, we conducted heating experiments of the simplest amino acid "glycine (Gly)" mixed with four simple anhydrous salts (MgSO 4, SrCl 2, BaCl 2 and Li 2SO 4) at 140 °C up to 20 days. Gly polymerization was strongly promoted by mixing with the salts in the order of MgSO 4 > SrCl 2 > BaCl 2 > Li 2SO 4. Up to 6-mer of Gly polymers were synthesized in the Gly-MgSO 4 mixture, and a total yield of Gly polymers attained about 7% of the initial amount of Gly by the 20 days heating. The total yield was about 200 times larger than that from the heating of Gly alone. XRD measurements of the Gly-MgSO 4 mixture revealed the generation of MgSO 4 monohydrate during Gly polymerization. These observations indicate that Gly polymerization was promoted by the salt hydrations through the hydration-dehydration interactions. Based on the observations, we tried to find a relationship between thermodynamic characteristics of the interactions and the promotion effects of each salt on Gly polymerization. It was found that the salts having lower hydration Δ rG0 (easier to hydrate) promote Gly polymerization more strongly. The relationship was used to estimate promotion effects of simple oxide minerals on Gly polymerization. The estimations were consistent with previous observations about the effects of these minerals on Gly polymerization. The fact suggests that the hydration-dehydration interactions between amino acids and minerals are an important mechanism for amino acids' polymerizations on minerals.

  6. Physiological Investigation and Transcriptome Analysis of Polyethylene Glycol (PEG)-Induced Dehydration Stress in Cassava

    PubMed Central

    Fu, Lili; Ding, Zehong; Han, Bingying; Hu, Wei; Li, Yajun; Zhang, Jiaming

    2016-01-01

    Cassava is an important tropical and sub-tropical root crop that is adapted to drought environment. However, severe drought stress significantly influences biomass accumulation and starchy root production. The mechanism underlying drought-tolerance remains obscure in cassava. In this study, changes of physiological characters and gene transcriptome profiles were investigated under dehydration stress simulated by polyethylene glycol (PEG) treatments. Five traits, including peroxidase (POD) activity, proline content, malondialdehyde (MDA), soluble sugar and soluble protein, were all dramatically induced in response to PEG treatment. RNA-seq analysis revealed a gradient decrease of differentially expressed (DE) gene number in tissues from bottom to top of a plant, suggesting that cassava root has a quicker response and more induced/depressed DE genes than leaves in response to drought. Overall, dynamic changes of gene expression profiles in cassava root and leaves were uncovered: genes related to glycolysis, abscisic acid and ethylene biosynthesis, lipid metabolism, protein degradation, and second metabolism of flavonoids were significantly induced, while genes associated with cell cycle/organization, cell wall synthesis and degradation, DNA synthesis and chromatin structure, protein synthesis, light reaction of photosynthesis, gibberelin pathways and abiotic stress were greatly depressed. Finally, novel pathways in ABA-dependent and ABA-independent regulatory networks underlying PEG-induced dehydration response in cassava were detected, and the RNA-Seq results of a subset of fifteen genes were confirmed by real-time PCR. The findings will improve our understanding of the mechanism related to dehydration stress-tolerance in cassava and will provide useful candidate genes for breeding of cassava varieties better adapted to drought environment. PMID:26927071

  7. Cellular and extracellular dehydration, and angiotensin as stimuli to drinking in the common iguana Iguana iguana.

    PubMed

    Fitzsimons, J T; Kaufman, S

    1977-02-01

    1. After water deprivation, the iguana promptly drank slightly more than enough water to restore the body fluids to isotonicity even under conditions of hypervolaemia. 2. In response to systemic injections of hypertonic solutions of NaCl and sucrose, the iguana drank and retained enough water to dilute the injected load to isotonicity irrespective of whether water was offered immediately or after 3 hr, and irrespective of whether the solute was administered I.V. or I.P. 3. Hypertonic solutions to glucose, urea, sorbitol and KCl caused little drinking. 4. The long latencies to drinking after hypertonic loads, which were not dependent on the nature of the solute, the route of administration or the dosage, were shown not to be a result of slow distribution of the solute throughout the body fluids. 5. Clearance of injected solutes via renal and extra-renal (nasal salt gland) routes was negligible during the 6 hr experimental period. 6. Measurements of plasma [Na], haematocrit, osmotic pressure and inulin space showed that the iguana drank, in response to cellular dehydration, enough water to restore the intracellular fluid volume to normal. 7. We conclude that, in response to substances which dehydrate cells, the iguana regulates its body osmolality precisely and efficiently provided it is able to do so by drinking. In this respect the responses of the iguana are similar to those of the nephrectomized rat since, in the short term, both rely exclusively on drinking to restore cellular water to normal. 8. The iguana also drinks in response to extracellular dehydration produced by hyperoncotic peritoneal dialysis, and in response to I.P. angiotensin II. PMID:850202

  8. The effects of progressive dehydration on strength and power: is there a dose response?

    PubMed

    Hayes, Lawrence D; Morse, Christopher I

    2010-03-01

    This study examined the effect of exercise- and heat-induced dehydration on strength, jump capacity and neuromuscular function. Twelve recreationally active males completed six resistance exercise bouts (baseline and after each 5 exposure sessions) in an increasing state of hypohydration obtained by repeated heat exposure and exercise sessions (5 periods of 20 min jogging at up to approximately 80% age predicted heart rate maximum at 48.5 +/- 0.48 degrees C, relative humidity 50 +/- 4%). Relative to starting values, body mass decreased 1.0 +/- 0.5, 1.9 +/- 0.7, 2.6 +/- 0.8, 3.3 +/- 0.9 and 3.9 +/- 1.0% after exposure 1, 2, 3, 4 and 5, respectively. However, plasma volume remained constant. No significant differences existed amongst trials in vertical jump height, electromyography data or isokinetic leg extension at a rate of 120 degrees s(-1). Isometric leg extensions were significantly reduced (P < 0.05) after the first (1% body mass loss) and subsequent exposures in comparison to baseline. Isokinetic leg extensions at a rate of 30 degrees s(-1) were significantly reduced after the third (2.6% body mass loss) and subsequent exposures compared with baseline. No dose response was identified in any of the tested variables yet a threshold was observed in isometric and isokinetic strength at 30 degrees s(-1). In conclusion, dehydration caused by jogging in the heat had no effect on vertical jumping or isokinetic leg extensions at a rate of 120 degrees s(-1). Alternatively, exercise-induced dehydration was detrimental to isometric and isokinetic leg extensions at a rate of 30 degrees s(-1), suggesting the force-velocity relationship in hypohydration merits further research. PMID:19908058

  9. Physiological Investigation and Transcriptome Analysis of Polyethylene Glycol (PEG)-Induced Dehydration Stress in Cassava.

    PubMed

    Fu, Lili; Ding, Zehong; Han, Bingying; Hu, Wei; Li, Yajun; Zhang, Jiaming

    2016-01-01

    Cassava is an important tropical and sub-tropical root crop that is adapted to drought environment. However, severe drought stress significantly influences biomass accumulation and starchy root production. The mechanism underlying drought-tolerance remains obscure in cassava. In this study, changes of physiological characters and gene transcriptome profiles were investigated under dehydration stress simulated by polyethylene glycol (PEG) treatments. Five traits, including peroxidase (POD) activity, proline content, malondialdehyde (MDA), soluble sugar and soluble protein, were all dramatically induced in response to PEG treatment. RNA-seq analysis revealed a gradient decrease of differentially expressed (DE) gene number in tissues from bottom to top of a plant, suggesting that cassava root has a quicker response and more induced/depressed DE genes than leaves in response to drought. Overall, dynamic changes of gene expression profiles in cassava root and leaves were uncovered: genes related to glycolysis, abscisic acid and ethylene biosynthesis, lipid metabolism, protein degradation, and second metabolism of flavonoids were significantly induced, while genes associated with cell cycle/organization, cell wall synthesis and degradation, DNA synthesis and chromatin structure, protein synthesis, light reaction of photosynthesis, gibberelin pathways and abiotic stress were greatly depressed. Finally, novel pathways in ABA-dependent and ABA-independent regulatory networks underlying PEG-induced dehydration response in cassava were detected, and the RNA-Seq results of a subset of fifteen genes were confirmed by real-time PCR. The findings will improve our understanding of the mechanism related to dehydration stress-tolerance in cassava and will provide useful candidate genes for breeding of cassava varieties better adapted to drought environment. PMID:26927071

  10. Impact of postharvest dehydration process of winegrapes on mechanical and acoustic properties of the seeds and their relationship with flavanol extraction during simulated maceration.

    PubMed

    Río Segade, Susana; Torchio, Fabrizio; Gerbi, Vincenzo; Quijada-Morín, Natalia; García-Estévez, Ignacio; Giacosa, Simone; Escribano-Bailón, M Teresa; Rolle, Luca

    2016-05-15

    This study represents the first time that the extraction of phenolic compounds from the seeds is assessed from instrumental texture properties for dehydrated grapes. Nebbiolo winegrapes were postharvest dehydrated at 20°C and 41% relative humidity. During the dehydration process, sampling was performed at 15%, 30%, 45% and 60% weight loss. The extractable fraction and extractability of phenolic compounds from the seeds were determined after simulated maceration. The evolution of mechanical and acoustic attributes of intact seeds was also determined during grape dehydration to evaluate how these changes affected the extraction of phenolic compounds. The extractable content and extractability of monomeric flavanols and proanthocyanidins, as well as the galloylation percentage of flavanols, might be predicted easily and quickly from the mechanical and acoustic properties of intact seeds. This would help in decision-making on the optimal dehydration level of winegrapes and the best management of winemaking of dehydrated grapes. PMID:26776049

  11. Watching dehydration: transient vein-shaped porosity in the oceanic mantle of the subducting Nazca slab

    NASA Astrophysics Data System (ADS)

    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

  12. Uniform amorphous lactose microspheres formed in simultaneous convective and dehydration antisolvent precipitation under atmospheric conditions.

    PubMed

    Mansouri, S; Fu, N; Woo, M W; Chen, X D

    2012-10-01

    A simultaneous convection-dehydration and antisolvent precipitation approach has been shown to produce uniform microsized lactose particles from aqueous droplet at atmospheric pressure. Microparticles with high uniformity having diameters of between 1.0 and 2.4 μm have been obtained. The precipitation of the microparticles is driven by a unique self-assembly mechanism that cannot be fully elucidated by supersaturation alone. Further analysis suggests that structural changes in the solvent/antisolvent mixture, due to hydrophobic hydration, could play a role in the precipitation process observed. PMID:22950653

  13. Structural changes of water in poly(vinyl alcohol) hydrogel during dehydration

    NASA Astrophysics Data System (ADS)

    Kudo, Kushi; Ishida, Junichi; Syuu, Gika; Sekine, Yurina; Ikeda-Fukazawa, Tomoko

    2014-01-01

    To investigate the mechanism of structural changes of water and polymer networks with drying and swelling, we measured the Raman spectra of a physically cross-linked poly(vinyl alcohol) (PVA) hydrogel synthesized using the freezing-thawing method. The results show that the vibrational frequencies of the O-H and C-H stretching modes decrease with dehydration. The frequency shifts observed are attributed to reduction of free water inside the polymer network. The C-H bonds elongate as the water density decreases, and the average length of the O-H bonds increases with increasing proportion of bound water to the total amount of water. On the basis of the dependence of the frequency shifts on the PVA concentration of the original solution, it was found that the structure of the polymer network in the reswollen hydrogel becomes inhomogeneous due to shrinkage of the polymer network with drying. Furthermore, to investigate the effects of the cross-linking structure on the drying process, these results were compared with those of a chemically cross-linked PVA hydrogel synthesized using glutaraldehyde as a cross-linker. The result shows that the vibrational frequency of the O-H stretching mode for the chemically cross-linked hydrogel increases with dehydration, whereas that of the C-H stretching mode decreases. The opposite trend observed in the O-H stretching mode between the physically and chemically cross-linked hydrogels is due to the difference in the shrinkage rate of the polymer network. Because the rate of shrinking is slow compared with that of dehydration in the chemically cross-linked hydrogel, water density in the polymer network decreases. For the physically cross-linked hydrogel, the polymer network structure can be easily shrunken, and the average strength of hydrogen bonds increases with dehydration. The results show that the structures of the polymer network and water change with the gel preparation process, cross-linking method, and drying and reswelling

  14. Separate and combined effects of dehydration and thirst sensation on exercise performance in the heat.

    PubMed

    Cheung, S S; McGarr, G W; Mallette, M M; Wallace, P J; Watson, C L; Kim, I M; Greenway, M J

    2015-06-01

    Using intravenous infusion, we separated the physiologic consequences of 3% body mass dehydration from the conscious awareness of fluid replacement on time trial (TT) performance in the heat. Eleven trained cyclists performed 90 min of steady-state (50% V ˙ O 2 peak ) cycling followed by a self-paced 20-km TT in a hot-dry (35 °C, 10% relative humidity, wind speed 3.0 m/s) environment while euhydrated-not thirsty (EU-NT), euhydrated-thirsty (EU-T), dehydrated-not thirsty (DH-NT), or dehydrated-thirsty (DH-T). Thirst was manipulated by providing (NT) or withholding (T) ad libitum 35 °C water oral rinse. Distinct hydration states existed, with 0.4 ± 0.5% dehydration following the 20-km TT (EU) compared with 3.2 ± 0.6% in DH (P < 0.001). Greater perceived thirst existed in T (7 ± 2 on a 1-9 scale) than NT (4 ± 2, P < 0.001) after the TT. No significant differences in power output existed during the TT between hydration (EU 202.9 ± 36.5 W vs DH 207.0 ± 35.9 W, P = 0.362) and thirst conditions (NT 203.3 ± 35.6 W vs T 206.6 ± 36.8 W, P = 0.548), nor were there differences in completion time (P = 0.832) or pacing profile (P = 0.690). Within the range of up to 3% body mass loss, neither the physiologic effects from lowered hydration status nor the perception of thirst, separately or combined, affected sustained submaximal exercise performance in the heat for a healthy and fit population. PMID:25943661

  15. Garnet growth as a proxy for progressive dehydration in subduction zones

    NASA Astrophysics Data System (ADS)

    Caddick, M. J.; Baxter, E. F.

    2012-12-01

    The release of volatiles from subducting lithologies is a crucial triggering process for arc magmatism, seismicity, the growth and maturation of continents, and the global geological H2O-CO2 cycle. While numerous models have been developed to predict slab volatile release, it has proven challenging to reconstruct and test these fluid fluxes released from specific lithologies in the rock record. Here we show that the growth of garnet may be used as a proxy for progressive devolatilization at blueschist to eclogite facies conditions in subduction zones. Generally, as garnet grows in a subducting rock, fluid is produced due to metamorphic dehydration reactions. Using rigorous thermodynamic analysis, which includes the crucial effects of phase fractionation, we model the proportional relationship between garnet and water production in common lithologies (pelitic sediment and hydrated MORB) along three representative subduction geotherms. The results show that several dehydration reactions contribute to garnet growth especially within a crucial span of the subduction zone (~1.5 to 2.5 GPa) within which slab-mantle decoupling has been predicted to occur in some models and volatile fluxes may be focused. The water:garnet production ratio varies during garnet growth, constrained by the specific hydrous reactant phases that are breaking down, but the average water:garnet production ratios are surprisingly consistent regardless of composition and geotherm. Over the garnet growth interval ~400 to 700 C (and corresponding depths for each geotherm) the average production ratio for altered MORB compositions is 0.52 (wt % water per vol % garnet) in cooler geotherms (Honshu and Nicaragua) and 0.27 in hotter (Cascadia) geotherms, with predictably lower ratios if the input basalt previously experienced less hydrous alteration. Over the same interval the water production ratios are approximately 50 % lower for pelite (0.24 and 0.13, respectively). Lower temperature water release is

  16. In vitro terahertz monitoring of muscle tissue dehydration under the action of hyperosmotic agents

    SciTech Connect

    Kolesnikov, A S; Kolesnikova, E A; Popov, A P; Tuchin, V V; Nazarov, M M; Shkurinov, A P

    2014-07-31

    Dehydration of muscle tissue in vitro under the action of biologically compatible hyperosmotic agents is studied using a laser terahertz spectrometer in the frequency range from 0.25 to 2.5 THz. Broadband terahertz absorption and reflection spectra of the bovine skeletal muscle tissue were obtained under the action of glycerol, polyethylene glycol with the molecular weight 600 (PEG-600), and propylene glycol. The presented results are proposed for application in developing the methods of image contrast enhancement and increasing the depth of biological tissue probing with terahertz radiation. (laser biophotonics)

  17. Solvent-free catalytic dehydrative etherification of benzyl alcohol over graphene oxide

    NASA Astrophysics Data System (ADS)

    Yu, Huiyou; Wang, Xinde; Zhu, Yuanshuai; Zhuang, Guilin; Zhong, Xing; Wang, Jian-guo

    2013-09-01

    Graphene oxide (GO), prepared from oxidation of graphite powders using a modified Hummers method, exhibits a promising catalytic activity and a high selectivity for the solvent-free catalytic dehydrative etherification of benzyl alcohol (BA). A maximum yield (85.4%) of dibenzyl ether (DE) was achieved at 150 °C for 24 h when the BA/GO ration was 20 ml/g under solvent-free condition. This discovery provided a new insight into the development of GO as a carbocatalysts for a variety of applications in carbocatalysis.

  18. Negative resists for electron-beam lithography utilizing acid-catalyzed intramolecular dehydration of phenylcarbinol

    NASA Astrophysics Data System (ADS)

    Migitaka, Sonoko; Uchino, Shou-ichi; Ueno, Takumi; Yamamoto, Jiro; Kojima, Kyoko; Hashimoto, Michiaki; Shiraishi, Hiroshi

    1996-06-01

    Acid-catalyzed intramolecular dehydration of phenylcarbinol is used to design highly sensitive negative resists for electron beam lithography. Of the phenylcarbinol resists evaluated in this study, the resist composed of 1,3-bis(alpha-hydroxyisopropyl)benzene (Diol-1), m/p-cresol novolak resin, and diphenyliodonium triflate (DIT) shows the best lithographic performance in terms of sensitivity and resolution. Fine 0.25-micrometer line-and-space patterns were formed by using the resist containing Diol-1 with a dose of 3.6 (mu) C/cm2 in conjunction with a 50 kV electron beam exposure system.

  19. In vitro terahertz monitoring of muscle tissue dehydration under the action of hyperosmotic agents

    NASA Astrophysics Data System (ADS)

    Kolesnikov, A. S.; Kolesnikova, E. A.; Popov, A. P.; Nazarov, M. M.; Shkurinov, A. P.; Tuchin, V. V.

    2014-07-01

    Dehydration of muscle tissue in vitro under the action of biologically compatible hyperosmotic agents is studied using a laser terahertz spectrometer in the frequency range from 0.25 to 2.5 THz. Broadband terahertz absorption and reflection spectra of the bovine skeletal muscle tissue were obtained under the action of glycerol, polyethylene glycol with the molecular weight 600 (PEG-600), and propylene glycol. The presented results are proposed for application in developing the methods of image contrast enhancement and increasing the depth of biological tissue probing with terahertz radiation.

  20. One-Step Production of 1,3-Butadiene from 2,3-Butanediol Dehydration.

    PubMed

    Liu, Xi; Fabos, Viktoria; Taylor, Stuart; Knight, David W; Whiston, Keith; Hutchings, Graham J

    2016-08-22

    We report the direct production of 1,3-butadiene from the dehydration of 2,3-butandiol by using alumina as catalyst. Under optimized kinetic reaction conditions, the production of methyl ethyl ketone and isobutyraldehyde, formed via the pinacol-pinacolone rearrangement, was markedly reduced and almost 80 % selectivity to 1,3-butadiene and 1,3-butadiene could be achieved. The presence of water plays a critical role in the inhibition of oligomerization. The amphoteric nature of γ-Al2 O3 was identified as important and this contributed to the improved catalytic selectivity when compared with other acidic catalysts. PMID:27392112

  1. Muscovite dehydration melting in Si-rich metapelites: microstructural evidence from trondhjemitic migmatites, Roded, Southern Israel

    NASA Astrophysics Data System (ADS)

    Anenburg, Michael; Katzir, Yaron

    2014-02-01

    Making a distinction between partial melting and subsolidus segregation in amphibolite facies migmatites is difficult. The only significant melting reactions at lowpressures, either vapour saturated or muscovite dehydration melting, do not produce melanocratic peritectic phases. If protoliths are Si-rich and K-poor, then peritectic sillimanite and K-feldspar will form in scarce amounts, and may be lost by retrograde rehydration. The Roded migmatites of southern Israel (northernmost Arabian Nubian Shield) formed at P = 4.5 ± 1 kbar and T ≤ 700 °C and include Si-rich, K-poor paragneissic paleosome and trondhjemitic leucosomes. The lack of K-feldspar in leucosomes was taken as evidence for the non-anatectic origin of the Roded migmatites (Gutkin and Eyal, Isr J Earth Sci 47:117, 1998). It is shown here that although the Roded migmatites experienced significant post-peak deformation and recrystallization, microstructural evidence for partial melting is retained. Based on these microstructures, coupled with pseudosection modelling, indicators of anatexis in retrograded migmatites are established. Phase diagram modelling of neosomes shows the onset of muscovite dehydration melting at 4.5 kbar and 660 °C, forming peritectic sillimanite and K-feldspar. Adjacent non-melted paleosomes lack muscovite and would thus not melt by this reaction. Vapour saturation was not attained, as it would have formed cordierite that does not exist. Furthermore, vapour saturation would not allow peritectic K-feldspar to form, however K-feldspar is ubiquitous in melanosomes. Direct petrographic evidence for anatexis is rare and includes euhedral plagioclase phenocrysts in leucosomes and quartz-filled embayments in corroded plagioclase at leucosome-melanosome interfaces. In deformed and recrystallized rocks muscovite dehydration melting is inferred by: (1) lenticular K-feldspar enclosed by biotite in melanosomes, (2) abundant myrmekite in leucosomes, (3) muscovite-quartz symplectites after

  2. Wine Glass Sign and Empty Delta Sign: A Rare Imaging Presentation of Postpartum Encephalopathy in Dehydration

    PubMed Central

    Suprasanna, K.; Dudekula, Anees; Hegde, Madhav; Kory, Swetha

    2016-01-01

    Rapid correction of hyponatremia is a well-known cause of central pontine and extrapontine myelinolysis. But uncommonly seen and rarely reported in Hypernatraemia. We report a rare case presenting as postpartum psychosis, wherein imaging revealed myelinolysis of corticospinal tracts in wine glass distribution and empty delta sign due to cortical venous thrombosis. At follow-up 3 months later, revealed significant neurological improvement. Concurrance occurrence of this dual pathology is not been described, which in our case was due to high serum sodium levels at presentation and dehydration. PMID:27504377

  3. Solar energy storage by natural zeolites: I. Dehydration of zeolitic tuff

    SciTech Connect

    Nastro, A.; Aiello, R.; Colella, C.; Conte, M.; Fittipaldi, F.

    1980-12-01

    In the perspective of a possible utilization of natural zeolites in the solar energy exploitation as materials suitable for heat storage, the behaviours of chabazitic and phillipsitic tuffs in the isothermal dehydration have been studied, evaluating the influence of temperature, heating rate and cationic form of the zeolite on the water desorption process. The possibility of achieving an almost complete desorption at temperatures of 200/250/sup 0/C in times of the order of two hours or less has been emphasized and indications on the heat amount storable by a chabazitic tuff in its original cationic form have been at last given.

  4. Talc and "talc"-bearing dehydrating serpentinite rheology within subduction zones

    NASA Astrophysics Data System (ADS)

    Hilairet, N.; Wang, Y.; Reynard, B.

    2008-12-01

    Fluids released by subducting slabs hydrate peridotites within the mantle wedge and produce weak phyllosilicates in significant quantities (1). Depending on the original chemistry of peridotites and on the silica content of the fluids, either talc or the high-pressure (HP) variety of serpentine antigorite, or both, can form down to 180 km depth. A talc-like phase is also produced transiently during serpentine dehydration (2). The extent to which such weak materials at the slab-mantle wedge interface can influence the dynamics of subduction zones from human (seismicity - post-seismic ground deformations) to geological (convection) timescales is still unknown. Promising deformation experiments on antigorite have shown that its low strength makes it a potential actor for governing silent earthquakes that release elastic energy in subduction zones and for localizing deformation at the slab interface, thereby modifying the mantle wedge convection, heat fluxes and seismic anisotropy (3). The strength of talc at low pressure is also exceptionally low compared to other silicates (4) and at sub-surface conditions the weakness of talc is thought to govern deformation in major faults such as San Andreas (5). At low pressures (< 500 MPa), talc behaves cataclastically and hardly achieves distributed deformation (4). However, higher pressures should promote crystal plasticity i.e. different deformation mechanisms in talc. Investigating the rheology of talc, and talc-bearing assemblage during serpentine dehydration, at P-T conditions corresponding to subducting slabs, is necessary in order to better understand localization of deformation in the slab-mantle wedge interface as well as the nature of this interface. We conducted deformation experiments using the D-DIA (6) apparatus at GSE-CARS (APS sector 13), with in situ strain and stress measurements using synchrotron X-ray imaging and diffraction, respectively. Stress-strain data were obtained on talc at P-T conditions between 2

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

    NASA Astrophysics Data System (ADS)

    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

  6. Selective dehydration of bio-ethanol to ethylene catalyzed by lanthanum-phosphorous-modified HZSM-5: influence of the fusel.

    PubMed

    Hu, Yaochi; Zhan, Nina; Dou, Chang; Huang, He; Han, Yuwang; Yu, Dinghua; Hu, Yi

    2010-11-01

    Bio-ethanol dehydration to ethylene is an attractive alternative to oil-based ethylene. The influence of fusel, main byproducts in the fermentation process of bio-ethanol production, on the bio-ethanol dehydration should not be ignored. We studied the catalytic dehydration of bio-ethanol to ethylene over parent and modified HZSM-5 at 250°C, with weight hourly space velocity (WHSV) equal to 2.0/h. The influences of a series of fusel, such as isopropanol, isobutanol and isopentanol, on the ethanol dehydration over the catalysts were investigated. The 0.5%La-2%PHZSM-5 catalyst exhibited higher ethanol conversion (100%), ethylene selectivity (99%), and especially enhanced stability (more than 70 h) than the parent and other modified HZSM-5. We demonstrated that the introduction of lanthanum and phosphorous to HZSM-5 could weaken the negative influence of fusel on the formation of ethylene. The physicochemical properties of the catalysts were characterized by ammonia temperature-programmed desorption (NH(3)-TPD), nitrogen adsorption and thermogravimetry (TG)/differential thermogravimetry (DTG)/differential thermal analysis (DTA) (TG/DTG/DTA) techniques. The results indicated that the introduction of lanthanum and phosphorous to HZSM-5 could inhibit the formation of coking during the ethanol dehydration to ethylene in the presence of fusel. The development of an efficient catalyst is one of the key technologies for the industrialization of bio-ethylene. PMID:21058319

  7. Inorganic compounds for passive solar energy storage: Solid-state dehydration materials and high specific heat materials

    NASA Astrophysics Data System (ADS)

    Struble, L. J.; Brown, P. W.

    1986-04-01

    Two classes of hydrated inorganic salts have been studied to assess their potential as materials for passive solar energy storage. The materials are part of the quaternary system CaO-Al2O3-SO3-H2O and related chemical systems, and the two classes are typified by ettringite, a trisubstituted salt, and Friedel's salt, a monosubstituted salt. The trisubstituted salts were studied for their possible application in latent heat storage, utilizing a low-temperature dehydration reaction, and both classes were studies for their application in sensible heat storage. In order to assess their potential for energy storage, the salts have been synthesized, characterized by several analytical techniques, and thermal properties measured. The dehydration data of that the trisubstituted salts vary somewhat with chemical composition, with the temperature of the onset of dehydration ranging from 6(0)C to 33(0)C, and enthalpy changes on dehydration ranging from 60 to 200 cal/g. Heat capacity is less variable with composition; values for the trisubstituted phases are 30 cal/g/(0)C and for the monosubstituted phases between 0.23 and 0.28 cal/g/(0)C. Preliminary experiments indicate that the dehydration is reversible, and suggest that the materials might have additional potential as solar desiccant materials. These thermal data demonstrate the trisubstituted salts have potential as latent heat storage materials, and that both classes of salts have potential as sensible heat storage materials.

  8. Insights on TTL dehydration mechanisms from microphysical modelling of aircraft observations

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

    The dynamical and microphysical processes that influence water vapor concentrations in the Tropical Tropopause Layer (TTL) are investigated in simulations of cloud formation and dehydration along air parcel trajectories. We 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. 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 tropics and elucidate the dominant processes in the winter and summer seasons. Implications of the TTL dehydration processes for the regulation of global stratospheric humidity will be discussed.

  9. Combined decellularisation and dehydration improves the mechanical properties of tissue-engineered sinews

    PubMed Central

    Lebled, Claire; Grover, Liam M

    2014-01-01

    Novel sources of replacement sinews are needed to repair damaged tissue after injury. The current methods of repair ultilise autografts, allografts or xenografts, although each method has distinct disadvantages that limit their success. Decellularisation of harvested tissues has been previously investigated for sinew repair with the long-term aim of repopulating the structure with autologous cells. Although this procedure shows promise, the demand for donor scaffolds will always outweigh supply. Here, we report the fabrication of fibrin-based tissue-engineered sinews, which can be decellularised, dehydrated and stored. The sinews may then be rehydrated and repopulated with an autologous cell population. In addition to enabling production of patient-specific implants, interestingly, the process of combined decellularisation, dehydration and rehydration enhanced the mechanical properties of the sinew. The treated sinews exhibited a 2.6-fold increase in maximum load and 8-fold increase in ultimate tensile strength when compared with the control group (p < 0.05 in both cases). PMID:24904729

  10. Effect of ultrasound treatment on the water state in kiwifruit during osmotic dehydration.

    PubMed

    Nowacka, M; Tylewicz, U; Laghi, L; Dalla Rosa, M; Witrowa-Rajchert, D

    2014-02-01

    The present work investigates how ultrasound pretreatment modulates the effects of osmotic dehydration (OD) on the water state and microstructure of kiwifruit. Kiwifruit slices (10mm thick) were subjected to ultrasonic waves in a water bath at a frequency of 35 kHz for 10, 20 and 30 min. OD process was then carried out by immersing the samples in 61.5% sucrose solution equilibrated at 25°C for a contact period of 0, 10, 20, 30, 60 and 120 min. The partition of water into the cellular tissue structures (vacuole, cytoplasm, extracellular spaces and cell wall) was investigated by Time Domain Nuclear Magnetic Resonance (TD-NMR). In parallel, the microstructure of kiwifruits slices was examined using a Scanning Electron Microscope. The results showed that US pretreatment performed for more than 10 min had a positive effect on the mass exchange caused by osmotic dehydration. A creation of microchannels and an increase of the average cross-section area of cells were observed when the samples were pretreated with US before OD. TD-NMR showed a slight redistribution of water through the substructures of the cells, as a function of the length of the US pretreatment applied. PMID:24099537

  11. Conformational coupling, bridge helix dynamics and active site dehydration in catalysis by RNA polymerase

    PubMed Central

    Seibold, Steve A.; Singh, Badri Nath; Zhang, Chunfen; Kireeva, Maria; Domecq, Céline; Bouchard, Annie; Nazione, Anthony M.; Feig, Michael; Cukier, Robert I.; Coulombe, Benoit; Kashlev, Mikhail; Hampsey, Michael; Burton, Zachary F.

    2010-01-01

    Molecular dynamics simulation of Thermus thermophilus (Tt) RNA polymerase (RNAP) in a catalytic conformation demonstrates that the active site dNMP-NTP base pair must be substantially dehydrated to support full active site closing and optimum conditions for phosphodiester bond synthesis. In silico mutant β R428A RNAP, which was designed based on substitutions at the homologous position (Rpb2 R512) of Saccharomyces cerevisiae (Sc) RNAP II, was used as a reference structure to compare to Tt RNAP in simulations. Long range conformational coupling linking a dynamic segment of the bridge α-helix, the extended fork loop, the active site, and the trigger loop-trigger helix is apparent and adversely affected in β R428A RNAP. Furthermore, bridge helix bending is detected in the catalytic structure, indicating that bridge helix dynamics may regulate phosphodiester bond synthesis as well as translocation. An active site “latch” assembly that includes a key trigger helix residue Tt β’ H1242 and highly conserved active site residues β E445 and R557 appears to help regulate active site hydration/dehydration. The potential relevance of these observations in understanding RNAP and DNAP induced fit and fidelity is discussed. PMID:20478425

  12. Putting to rest the myth of creatine supplementation leading to muscle cramps and dehydration.

    PubMed

    Dalbo, V J; Roberts, M D; Stout, J R; Kerksick, C M

    2008-07-01

    Creatine is one of the most popular athletic supplements with sales surpassing 400 million dollars in 2004. Due to the popularity and efficacy of creatine supplementation over 200 studies have examined the effects of creatine on athletic performance. Despite the abundance of research suggesting the effectiveness and safety of creatine, a fallacy appears to exist among the general public, driven by media claims and anecdotal reports, that creatine supplementation can result in muscle cramps and dehydration. Although a number of published studies have refuted these claims, a recent position statement by the American College of Sports Medicine (ACSM) in 2000 advised individuals who are managing their weight and exercising intensely or in hot environments to avoid creatine supplementation. Recent reports now suggest that creatine may enhance performance in hot and/or humid conditions by maintaining haematocrit, aiding thermoregulation and reducing exercising heart rate and sweat rate. Creatine may also positively influence plasma volume during the onset of dehydration. Considering these new published findings, little evidence exists that creatine supplementation in the heat presents additional risk, and this should be taken into consideration as position statements and other related documents are published. PMID:18184753

  13. Dramatic improvement of crystals of large RNAs by cation replacement and dehydration

    PubMed Central

    Zhang, Jinwei; Ferré-D’Amare, Adrian R.

    2014-01-01

    Summary Compared to globular proteins, RNAs with complex three-dimensional folds are characterized by poorly differentiated molecular surfaces dominated by backbone phosphates, sparse tertiary contacts stabilizing global architecture, and conformational flexibility. The resulting generally poor order of crystals of large RNAs and their complexes frequently hampers crystallographic structure determination. We describe and rationalize a post-crystallization treatment strategy that exploits the importance of solvation and counterions for RNA folding. Replacement of Li+ and Mg2+ needed for growth of crystals of a tRNA-riboswitch-protein co-crystal with Sr2+, coupled with dehydration, dramatically improved the resolution limit (8.5 to 3.2 Å) and data quality, enabling structure determination. The soft Sr2+ ion forms numerous stabilizing intermolecular contacts. Comparison of pre- and post-treatment structures reveals how RNA assemblies redistribute as quasi-rigid bodies to yield improved crystal packing. Cation exchange complements previously reported post-crystallization dehydration of protein crystals, and represents a potentially general strategy for improving crystals of large RNAs. PMID:25185828

  14. Dramatic improvement of crystals of large RNAs by cation replacement and dehydration.

    PubMed

    Zhang, Jinwei; Ferré-D'Amaré, Adrian R

    2014-09-01

    Compared to globular proteins, RNAs with complex 3D folds are characterized by poorly differentiated molecular surfaces dominated by backbone phosphates, sparse tertiary contacts stabilizing global architecture, and conformational flexibility. The resulting generally poor order of crystals of large RNAs and their complexes frequently hampers crystallographic structure determination. We describe and rationalize a postcrystallization treatment strategy that exploits the importance of solvation and counterions for RNA folding. Replacement of Li(+) and Mg(2+) needed for growth of crystals of a tRNA-riboswitch-protein complex with Sr(2+), coupled with dehydration, dramatically improved the resolution limit (8.5-3.2 Å) and data quality, enabling structure determination. The soft Sr(2+) ion forms numerous stabilizing intermolecular contacts. Comparison of pre- and posttreatment structures reveals how RNA assemblies redistribute as quasi-rigid bodies to yield improved crystal packing. Cation exchange complements previously reported postcrystallization dehydration of protein crystals and represents a potentially general strategy for improving crystals of large RNAs. PMID:25185828

  15. The use of body mass changes as a practical measure of dehydration in team sports.

    PubMed

    Harvey, Gemma; Meir, Rudi; Brooks, Lyndon; Holloway, Kate

    2008-11-01

    Body mass changes, hematocrit, specific gravity and urine colour were recorded during two games of soccer to determine which of these methods was the most practical in a field setting for monitoring dehydration. Members (n=13) of a premiership soccer team with a mean age of 22.6 (+/-4.9) years old, height of 177.8 (+/-7.1)cm and sum of skinfolds (four sites) of 37 (+/-12.8) were invited to participate in this study with 11 participating in each game. Players had weight, hematocrit, specific gravity and urine colour recorded pre- and post-game. Players were allowed to ingest fluid ad libitum throughout the matches with the amount consumed recorded. Urine excretion was also recorded and included in the calculation of final body mass loss (kg). A mean ambient temperature of 21 degrees C and relative humidity 77% was recorded for both games. Pre- and post-game body mass, sweat loss, hematocrit, urine specific gravity and colour were significantly different (p<0.01) for both games. Linear mixed effects models were fitted to the data in order to identify an optimal prediction equation for sweat loss. The model predicting from mass change was clearly the best fitting. The results demonstrate that a change in body mass during a game of soccer is an effective method of monitoring dehydration due to sweat loss when compared to other known methods that may be invasive and inappropriate in the field. PMID:17888734

  16. Photochemical reactions of chlorophyll in dehydrated photosystem II: two chlorophyll forms (680 and 700 nm).

    PubMed

    Heber, Ulrich; Shuvalov, Vladimir A

    2005-06-01

    Lichens and phototolerant poikilohydric mosses differ from spinach leaves, fern fronds or photosensitive mosses in that they show strongly decreased Fo chlorophyll fluorescence after drying. This desiccation-induced fluorescence loss is rapidly reversible under rehydration. Fluorescence emission from Photosystem II at 685 nm was decreased more strongly by dehydration than 720 nm emission. Reaction centers of Photosystem II lose activity on dehydration and regain it on hydration. Heating of desiccated lichens increased Fo chlorophyll fluorescence. The activation energy for the reversible part of the temperature-dependent fluorescence increase was 0.045 eV, which corresponds to the energy difference between the 680 and 697 nm absorption bands. In desiccated chlorolichens such as Parmelia sulcata, heating induces the appearance of positive variable fluorescence related to the reversible reduction of QA due to overcoming the energy barrier. This is interpreted to provide information on the mechanism of photoprotection: energy is dissipated by changing Chl680 or P680 into a chlorophyll form, which absorbs at 700 nm and emits light at 720 nm (Chl-720 or P680(700)) with a low quantum yield. Dissipation of light energy in this trap is activated by desiccation. PMID:16049759

  17. Evolution of nanostructure and specific surface area during thermally driven dehydration of Mg(OH)2

    NASA Astrophysics Data System (ADS)

    Pimminger, H.; Habler, G.; Freiberger, N.; Abart, R.

    2016-01-01

    The thermally induced dehydration of micrometer-sized particles of Mg(OH)2 was investigated experimentally at ambient pressure and temperatures ranging from 350 to 1300 °C. Reaction progress is correlated with the evolution of the specific surface area and of the particle internal nanostructure. The maximum specific surface area of about 320 m2/g corresponding to a 70-fold increase relative to the starting material is obtained after heat treatment at 350 °C for about 2 h. This is due to the formation of a highly porous, particle-internal nanostructure comprised of newly crystallized strictly aligned, cube-shaped and nanometer-sized crystals of MgO and about 50 vol% porosity. Associated with the dehydration, intensive fracturing and defoliation occurs parallel to the (0001) plane of the original Mg(OH)2 or (111) of the topotaxially grown MgO. After heat treatment at increasingly higher temperatures, enhanced coarsening and sintering of the MgO crystals and healing of cracks leads to a successive decrease of the specific surface area. After heat treatment at 1300 °C for 2.5 h, the specific surface area has decreased to 5 m2/g close to the value typical for the original Mg(OH)2.

  18. Powder lemon juice containing oligosaccharides obtained by dextransucrase acceptor reaction synthesis and dehydrated in sprouted bed.

    PubMed

    Coelho, Raquel Macedo Dantas; Araújo, Antônia Daiana Andrade; Fontes, Cláudia Patrícia Mourão Lima; da Silva, Ana Raquel Araujo; da Costa, José Maria Correia; Rodrigues, Sueli

    2015-09-01

    Oligosaccharides can be synthesized using the sugars present in the fruit juices through the dextransucrase acceptor reaction. In the present work, the effect of reducing sugar and sucrose concentration on oligosaccharide formation in lemon juice was evaluated through response surface methodology. The oligosaccharide formation in lemon juice was favored at high concentrations of sucrose (75 g/L) and reducing sugar (75 g/L). At this synthesis conditions, an oligosaccharide concentration of 94.81 g/L was obtained with a conversion of 63.21% of the initial sugars into the target product. Oligosaccharides with degree of polymerization up to 11 were obtained. The lemon juice was dehydrated in spouted bed using maltodextrin as drying adjuvant. The powder obtained at 60°C with 20 % maltodextrin presented low moisture (2.24 %), low water activity (Aw = 0.18) and the lowest reconstitution time (~46 s). The results showed that lemon juice is suitable for oligosaccharides enzyme synthesis and can be dehydrated in spouted bed. PMID:26345014

  19. Effect of dehydration on hypothalamic control of evaporation in the cat.

    PubMed Central

    Baker, M A; Doris, P A

    1982-01-01

    1. Cats were surgically prepared with intracranial thermodes for heating of the hypothalamic thermosensitive area or with venous cannulae for measurement of blood volume and plasma osmolality. They were kept in an environmental chamber in which the ambient temperature was cycled between 25 and 38 degrees C on an 18:6 hr diurnal schedule. 2. Measurements of blood volume and plasma osmolality and of the evaporative response to hypothalamic heating were made during the 38 degrees C phase of the diurnal temperature cycle in animals when they were hydrated ad lib and in the same animals after 72--96 hr of water deprivation. 3. Water deprivation produced a loss of 10% of the body weight, a significant rise in plasma osmolality and a significant fall in blood volume. 4. Hypothalamic heating in hydrated animals generated a highly significant, positive, linear relationship between hypothalamic temperature and evaporative heat loss in every case. 5. In dehydrated animals, the evaporative response to hypothalamic heating was reduced. Rates of evaporation at a given hypothalamic temperature were lower and the slopes of the lines relating evaporative heat loss to hypothalamic temperature were significantly reduced. 6. It is concluded that dehydration reduces the thermal responsiveness of central neural structures controlling evaporation in the cat. PMID:7069627

  20. Mantle wedge infiltrated with saline fluids from dehydration and decarbonation of subducting slab

    PubMed Central

    Kawamoto, Tatsuhiko; Yoshikawa, Masako; Kumagai, Yoshitaka; Mirabueno, Ma. Hannah T.; Okuno, Mitsuru; Kobayashi, Tetsuo

    2013-01-01

    Slab-derived fluids play an important role in heat and material transfer in subduction zones. Dehydration and decarbonation reactions of minerals in the subducting slab have been investigated using phase equilibria and modeling of fluid flow. Nevertheless, direct observations of the fluid chemistry and pressure–temperature conditions of fluids are few. This report describes CO2-bearing saline fluid inclusions in spinel-harzburgite xenoliths collected from the 1991 Pinatubo pumice deposits. The fluid inclusions are filled with saline solutions with 5.1 ± 1.0% (wt) NaCl-equivalent magnesite crystals, CO2-bearing vapor bubbles, and a talc and/or chrysotile layer on the walls. The xenoliths contain tremolite amphibole, which is stable in temperatures lower than 830 °C at the uppermost mantle. The Pinatubo volcano is located at the volcanic front of the Luzon arc associated with subduction of warm oceanic plate. The present observation suggests hydration of forearc mantle and the uppermost mantle by slab-derived CO2-bearing saline fluids. Dehydration and decarbonation take place, and seawater-like saline fluids migrate from the subducting slab to the mantle wedge. The presence of saline fluids is important because they can dissolve more metals than pure H2O and affect the chemical evolution of the mantle wedge. PMID:23716664

  1. Clustering reveals cavitation-related acoustic emission signals from dehydrating branches.

    PubMed

    Vergeynst, Lidewei L; Sause, Markus G R; De Baerdemaeker, Niels J F; De Roo, Linus; Steppe, Kathy

    2016-06-01

    The formation of air emboli in the xylem during drought is one of the key processes leading to plant mortality due to loss in hydraulic conductivity, and strongly fuels the interest in quantifying vulnerability to cavitation. The acoustic emission (AE) technique can be used to measure hydraulic conductivity losses and construct vulnerability curves. For years, it has been believed that all the AE signals are produced by the formation of gas emboli in the xylem sap under tension. More recent experiments, however, demonstrate that gas emboli formation cannot explain all the signals detected during drought, suggesting that different sources of AE exist. This complicates the use of the AE technique to measure emboli formation in plants. We therefore analysed AE waveforms measured on branches of grapevine (Vitis vinifera L. 'Chardonnay') during bench dehydration with broadband sensors, and applied an automated clustering algorithm in order to find natural clusters of AE signals. We used AE features and AE activity patterns during consecutive dehydration phases to identify the different AE sources. Based on the frequency spectrum of the signals, we distinguished three different types of AE signals, of which the frequency cluster with high 100-200 kHz frequency content was strongly correlated with cavitation. Our results indicate that cavitation-related AE signals can be filtered from other AE sources, which presents a promising avenue into quantifying xylem embolism in plants in laboratory and field conditions. PMID:27095256

  2. Enterobacteriaceae in dehydrated powdered infant formula manufactured in Indonesia and Malaysia.

    PubMed

    Estuningsih, Sri; Kress, Claudia; Hassan, Abdulwahed A; Akineden, Omer; Schneider, Elisabeth; Usleber, Ewald

    2006-12-01

    To determine the occurrence of Salmonella and Shigella in infant formula from Southeast Asia, 74 packages of dehydrated powdered infant follow-on formula (recommended age, > 4 months) from five different manufacturers, four from Indonesia and one from Malaysia, were analyzed. None of the 25-g test portions yielded Salmonella or Shigella. However, further identification of colonies growing on selective media used for Salmonella and Shigella detection revealed the frequent occurrence of several other Enterobacteriaceae species. A total of 35 samples (47%) were positive for Enterobacteriaceae. Ten samples (13.5%) from two Indonesian manufacturers yielded Enterobacter sakazakii. Other Enterobacteriaceae isolated included Pantoea spp. (n = 12), Escherichia hermanii (n = 10), Enterobacter cloacae (n = 8), Klebsiella pneumoniae subsp. pneumoniae (n = 3), Citrobacter spp. (n = 2), Serratia spp. (n = 2), and Escherichia coli (n = 2). To our knowledge, this is the first report to describe the contamination of dehydrated powdered infant formula from Indonesia with E. sakazakii and several other Enterobacteriaceae that could be opportunistic pathogens. Improper preparation and conservation of these products could result in a health risk for infants in Indonesia. PMID:17186672

  3. Formyl-Modified Polyaniline for the Catalytic Dehydration of Fructose to 5-Hydroxymethylfurfural.

    PubMed

    Zhu, Liangfang; Dai, Jinhang; Liu, Mingyang; Tang, Dianyong; Liu, Shuqing; Hu, Changwei

    2016-08-23

    We report an unprecedented solid organic-base catalyst, formyl-modified polyaniline (FS-PAN), for the dehydration of fructose to 5-hydroxymethylfurfural (HMF) with a high yield of 90.4 mol %. We demonstrate that the nitrogen atoms incorporated between the phenyl rings in the backbone of the polyaniline chain contribute to the basicity of the catalyst. The grafting of electron-withdrawing formyl groups to the imine nitrogen atoms leads to a significant increase of basicity of the polymer catalyst owing to the greater localization of electrons at the amide nitrogen atom formed. A linear dependence of the yield of HMF on the grafting level of formyl groups in FS-PAN indicates that the amide acts as the active phase. A possible reaction mechanism for this organic-base-catalyzed dehydration reaction is proposed. The side-reaction of HMF rehydration is inhibited thoroughly, and the condensation of any reaction intermediates to undesirable oligomers is restrained by this base catalyst. This organic-base catalyst can be recycled completely without loss of activity. This research highlights the first application of a highly effective and stable solid base catalyst for the transformation of renewable carbohydrates into fine chemicals. PMID:27453215

  4. Theoretical and experimental investigation of desalting and dehydration of crude oil by assistance of ultrasonic irradiation.

    PubMed

    Check, Gholam Reza; Mowla, Dariush

    2013-01-01

    In this paper desalting/dehydration process of crude oil by ultrasonic irradiation in a novel batch standing-wave resonator reactor is studied both theoretically and experimentally. The effect of main parameters including ultrasonic irradiation parameters, namely irradiation input power and irradiation time, and also operating parameters, such as temperature and injected water, on the removal efficiencies of salt and water is examined. The obtained results demonstrate that finding the optimum values of the above mentioned parameters is important to prevent a significant decrease in the removal efficiencies of water and especially salt. Thus, crude oil was subjected to optimal ultrasonic irradiation with an input power of 57.7 W, and irradiation time of 6.2 min at temperature of 100 °C. The injected water to dissolve the salt of crude oil was 7 vol.%. Also, the applied settling time and dosage of chemical demulsifier were 60 min and 2 ppm, respectively. Under these optimum conditions the removal efficiencies of the desalting/dehydration process were 84% and 99.8%, respectively, which are suitable for refineries. Also, based on the optimal experimental data, two inferential estimators are developed to obtain the relationships between the salt and water removal efficiencies, and input energy density. These empirical relationships can offer a proper estimation for the salt and water removal efficiencies with irradiation input energy. PMID:22795230

  5. Cryopreservation of Pistacia spp. seeds by dehydration and one-step freezing.

    PubMed

    Ozden-Tokatli, Y; Ozudogru, E A; Gumusel, F; Lambardi, M

    2007-01-01

    Cryopreservation protocols by dehydration and one-step freezing were developed for seeds from three Pistacia species, i.e., P. vera, P. terebinthus and P. lentiscus, which were characterised by different initial germination percentages (100%, 17% and 81%, respectively). In P. vera, a maximum of 90% germination was obtained following 8 hours drying in silica gel (corresponding to 11.7% moisture content on a FW basis) and direct immersion in LN. In P. terebinthus and P. lentiscus, shorter periods of dehydration (1 hour and 15 min, respectively) were sufficient to reduce their moisture content to about 20%, which resulted in peak seed germination percentages from cryostorage of 16% and 47%, respectively. Following cryopreservation, the seeds germinated better on semi-solid MS medium, than on cotton wool wetted with dH(2)O or liquid MS medium. Finally, in P. vera and P. lentiscus, high and significant correlation coefficients were obtained between the TTC viability test and seed germinability after recovery from LN, provided that seeds which were considered positive in the test showed completely or partially red embryonic axes coupled to completely red cotyledons. PMID:17522727

  6. Mechanism allowing an insect to survive complete dehydration and extreme temperatures.

    PubMed

    Watanabe, M; Kikawada, T; Minagawa, N; Yukuhiro, F; Okuda, T

    2002-09-01

    Cryptobiosis describes the state of an organism whose body water is completely dehydrated and metabolic activity has become undetectable. Our study aimed to elucidate the physiological mechanism of cryptobiosis in the highest cryptobiotic invertebrate, Polypedilum vanderplanki. Larvae of this insect rapidly accumulated a large amount of the carbohydrate, trehalose, (18% of dry body mass) during desiccation for 2 days, suggesting that a high level of trehalose accumulation contributed to the successful induction of cryptobiosis in P. vanderplanki as well as in other lower cryptobiotic organisms. When larvae deprived of the brain, suboesophageal ganglion (SG) and thoracic ganglia (TG) were completely dehydrated and then rehydrated, they were able to recover and move actively. During desiccation, such larvae also accumulated trehalose, although only about half as much as the intact larvae. It is concluded that the brain, SG and TG do not affect the induction and termination of cryptobiosis, and hence in this higher multicellular animal cryptobiosis is independent of brain, SG and TG regulation, just as in plants or in unicellular organisms. PMID:12177145

  7. Mantle wedge infiltrated with saline fluids from dehydration and decarbonation of subducting slab.

    PubMed

    Kawamoto, Tatsuhiko; Yoshikawa, Masako; Kumagai, Yoshitaka; Mirabueno, Ma Hannah T; Okuno, Mitsuru; Kobayashi, Tetsuo

    2013-06-11

    Slab-derived fluids play an important role in heat and material transfer in subduction zones. Dehydration and decarbonation reactions of minerals in the subducting slab have been investigated using phase equilibria and modeling of fluid flow. Nevertheless, direct observations of the fluid chemistry and pressure-temperature conditions of fluids are few. This report describes CO2-bearing saline fluid inclusions in spinel-harzburgite xenoliths collected from the 1991 Pinatubo pumice deposits. The fluid inclusions are filled with saline solutions with 5.1 ± 1.0% (wt) NaCl-equivalent magnesite crystals, CO2-bearing vapor bubbles, and a talc and/or chrysotile layer on the walls. The xenoliths contain tremolite amphibole, which is stable in temperatures lower than 830 °C at the uppermost mantle. The Pinatubo volcano is located at the volcanic front of the Luzon arc associated with subduction of warm oceanic plate. The present observation suggests hydration of forearc mantle and the uppermost mantle by slab-derived CO2-bearing saline fluids. Dehydration and decarbonation take place, and seawater-like saline fluids migrate from the subducting slab to the mantle wedge. The presence of saline fluids is important because they can dissolve more metals than pure H2O and affect the chemical evolution of the mantle wedge. PMID:23716664

  8. Quality characteristics of dehydrated egg yolk paneer and changes during storage.

    PubMed

    Pawar, Deepthi P; Das, Rashmi M; Kumar Modi, Vinod

    2012-08-01

    A shelf stable, convenience product egg yolk paneer (EYP) was developed by incorporation of optimized quantities of binders, salt, natural antioxidants and egg yolk. Dehydrated EYP was packed in metalised polyester pouches, stored at ambient temperature (27 ± 2 °C) for 6 months and sampled periodically for quality evaluation. The protein and fat content of dehydrated EYP was 26.2 ± 1.75% and 36.1 ± 2.46, respectively. The shelf stability of the product was achieved by keeping a moisture content (5.6 ± 0.50%) and water activity (0.43 ± 0.05) low. An excellent rehydration capacity (64.8 ± 5.39%) was observed in the EYP, whereas, the rehydration ratio of the product was 1:2.7. Changes in Free Fatty Acids, Thiobarbituric acid, textural profile analysis and Hunter colour units (L, a and b) during storage did not affect the quality characteristics of the product. About 38% loss in carotenoid content was recorded during storage of the product. Staphylococcus aureus, E coli, Salmonella and Shigella, however, were not detected in any sample throughout the storage period. Sensory evaluation revealed that rehydrated yolk paneer had excellent texture and was very close to fresh ones (before drying) during storage for 6 months. PMID:23904656

  9. Dehydration in the lower Antarctic stratosphere in late winter and spring

    NASA Technical Reports Server (NTRS)

    Kelly, K. K.; Tuck, A. F.; Fahey, D. W.; Proffitt, M. H.; Murphy, D. M.; Jones, R. L.; Mckenna, D. S.; Heidt, L. E.; Ferry, G. V.; Loewenstein, M.

    1988-01-01

    The history of minimum temperatures at 50 and 70 mb is examined from NMC, UK Met 0 and ECMWF analyses. MSU channel 24 data are similarly inspected. South Pole sonde data are used to calculate saturation humidity mixing ratio as a function of altitude and time throughout 1987. Saturation with respect to ice could be maintained for water mixing ratios of 3.5 ppmv for a period of about 80 days from mid-June to mid-September. Dehydration to mixing ratios of 1 ppmv or less was possible sporadically. Data from the ER-2 flights between 53 S and 72 S are used in conjunction with particle size measurements and air parcel trajectories to demonstrate the dehydration occurring over Antarctica. Water mixing ratios at the latitude of Punta Arenas (53 S), in conjunction with tracer measurements and trajectory analysis, show that at potential temperatures from about 325 to 400 K, the dryness (less than 3 ppmv) had its origin over Antarctica rather than in the tropics. Water mixing ratios within the Antarctic vortex varied from 1.5 to 3.8 ppmv, with a strong isentropic gradient being evident in the region of high potential vorticity gradients.

  10. Dehydration in the lower Antarctic stratosphere during late winter and early spring, 1987

    NASA Technical Reports Server (NTRS)

    Kelly, K. K.; Tuck, A. F.; Murphy, D. M.; Fahey, D. W.; Proffitt, M. H.; Jones, R. L.; Mckenna, D. S.; Loewenstein, M.; Podolske, J. P.; Strahan, S. E.

    1989-01-01

    The history of minimum temperatures at 50 and 70 mb is examined from NMC, UK Met O and ECMWF analyses. MSU channel 24 data are similarly inspected. South Pole sonde data are used to calculate saturation humidity mixing ratio as a function of altitude and time throughout 1987. Saturation with respect to ice could be maintained for water mixing ratios of 3.5 ppmv for a period of about 80 days from mid-June to mid-September. Dehydration to mixing ratios of 1 ppmv or less was possible sporadically. Data from the ER-2 flights between 53 S and 72 S are used in conjunction with particle size measurements and air parcel trajectories to demonstrate the dehydration occurring over Antarctica. Water mixing ratios at the latitude of Punta Arens (53 S), in conjunction with tracer measurements and trajectory analysis, show that at potential temperatures from about 325 to 400 K, the dryness (less than 3 ppmv) had its origin over Antarctica rather than in the tropics. Water mixing ratios within the Antarctic vortex varied from 1.5 to 3.8 ppmv, with a strong isentropic gradient being evident in the region of high potential vorticity gradients.

  11. The January 30, 1989 Arctic polar stratospheric clouds (PSC) event - Evidence for a mechanism of dehydration

    NASA Technical Reports Server (NTRS)

    Gandrud, B. W.; Dye, J. E.; Baumgardner, D.; Ferry, G. V.; Loewenstein, M.; Chan, K. R.; Sanford, L.; Gary, B.

    1990-01-01

    In-situ particle measurements made aboard the NASA ER-2 in the Arctic on 890130 (YYMMDD) show Type 1 PSC particles over much of the flight, with instances of embedded Type 2 PSCs. The Type 2 particles were observed at temperatures warmer than the local frost-point temperature of water; extended up to the upper size cutoff of the instrument (about 24-micron diameter); and are shown to contain too large a volume to be primarily NAT. Based on measured vertical temperature profiles, it is concluded that the Type 2 particles observed on this day were formed above the aircraft in a region where saturation with respect to ice was achieved and were sufficiently large to have fallen into the path of the ER-2. Although the amount of material in the particles, expressed as water, is small by comparison to the total (vapor + aerosol) water concentration, the flux of water from the falling particles is of sufficient magnitude, if sustained, to lead to dehydration of the source region. These observations verify the mechanism for dehydration of polar vortex air masses by precipitation of ice particles.

  12. Synthesis of Surface-Responsive Composite Particles by Dehydration of Water-in-Oil Emulsions.

    PubMed

    Liang, Chen; Liu, Qingxia; Xu, Zhenghe

    2015-09-23

    Organic composite particles were prepared by first emulsifying an aqueous sodium carboxymethyl cellulose (CMC) solution in a nonaqueous ethylcellulose (EC) solution, followed by dehydrating emulsified water droplets. CMC and EC are both biodegradable nontoxic materials, but have contrasting properties. CMC is a charged water-soluble polymer, while EC is an uncharged interfacially active water-insoluble polymer. The simple preparative method does not consume unnecessary chemical reagents and produces no waste material. The composite particles prepared by dehydrating emulsion droplets are readily dispersed in organic media due to its biwettable surface terminated with interfacially active EC molecules, which allows composite particles to preferentially adsorb at the oil-water droplet interface. The surface of composite particles, furthermore, is water-permeable, which allows water to be absorbed from emulsified droplets. The size, composition, and structure of the synthesized composite particles are ideally suited for absorption of stabilized water droplets from oil-continuous emulsions. The use of the composite absorbent particles, described herein, presents another viable strategy for dewatering water-in-oil emulsions. PMID:26302364

  13. Prevention of cartilage dehydration in imaging studies with a customized humidity chamber

    NASA Astrophysics Data System (ADS)

    Choo, Ryan J.; Firminger, Colin; Müller, Ralph; Stok, Kathryn S.

    2013-09-01

    Quantitative three-dimensional imaging methods such as micro-computed tomography (μCT) allow for the rapid and comprehensive evaluation of cartilage and bone in animal models, which can be used for drug development and related research in arthritis. However, when imaging fresh cartilage tissue in air, a common problem is tissue dehydration which causes movement artifact in the resulting images. These artifacts distort scans and can render them unusable, leading to a considerable loss of time and effort with sample preparation and measurement. The sample itself is also irretrievably damaged by the dehydration, often unable to return to its full tissue thickness upon rehydration. Additionally, imaging with ionic contrast agents such as HexabrixTM must be performed in air, otherwise the agent will be washed out if immersed in a liquid. The first goal of this study was to design a customized humidity chamber to maintain cartilage hydration without the need for immersion. Following this, the use of the humidity chamber during a synchrotron radiation-μCT scan was validated and its performance evaluated. Results showed that the loss of fluid film volume is associated with scanning at low humidity (87%), and can be avoided using the humidity chamber. Coupling this technology with advances in synchrotron imaging (e.g., phase contrast imaging) or contrast agents is promising.

  14. Dehydration of Glycerin to Acrolein Over Heteropolyacid Nano-Catalysts Supported on Silica-Alumina.

    PubMed

    Kang, Tae Hun; Choi, Jung Ho; Choi, Jun Seon; Song, In Kyu

    2015-10-01

    A series of H3PW12O40 nano-catalysts supported on silica-alumina (XH3PW12O40/SA (X = 10, 15, 20, 25, and 30)) with different H3PW12O40 content (X, wt%) were prepared, and they were applied to the dehydration of glycerin to acrolein. The effect of H3PW12O40 content on the physicochemical properties and catalytic activities of XH3PW12O40/SA nano-catalysts was investigated. Surface area and pore volume of XH3PW12O40/SA catalysts decreased with increasing H3PW12O40 content. Formation of H3PW12O40 aggregates was observed in the catalysts with high H3PW12O40 loading. Brønsted acidity of the catalysts showed a volcano-shaped trend with respect to H3PW12O40 content. It was revealed that yield for acrolein increased with increasing Brønsted acidity of XH3PW12O40/SA catalysts. Brønsted acidity of XH3PW12O40/SA catalysts served as a crucial factor determining the catalytic performance in the dehydration of glycerin. Among the catalysts tested, 25H3PW12O40/SA catalyst with the largest Brønsted acidity showed the best catalytic performance. PMID:26726511

  15. A biomechanical model of anther opening reveals the roles of dehydration and secondary thickening

    PubMed Central

    Nelson, M R; Band, L R; Dyson, R J; Lessinnes, T; Wells, D M; Yang, C; Everitt, N M; Jensen, O E; Wilson, Z A

    2012-01-01

    Summary Understanding the processes that underlie pollen release is a prime target for controlling fertility to enable selective breeding and the efficient production of hybrid crops. Pollen release requires anther opening, which involves changes in the biomechanical properties of the anther wall. In this research, we develop and use a mathematical model to understand how these biomechanical processes lead to anther opening. Our mathematical model describing the biomechanics of anther opening incorporates the bilayer structure of the mature anther wall, which comprises the outer epidermal cell layer, whose turgor pressure is related to its hydration, and the endothecial layer, whose walls contain helical secondary thickening, which resists stretching and bending. The model describes how epidermal dehydration, in association with the thickened endothecial layer, creates forces within the anther wall causing it to bend outwards, resulting in anther opening and pollen release. The model demonstrates that epidermal dehydration can drive anther opening, and suggests why endothecial secondary thickening is essential for this process (explaining the phenotypes presented in the myb26 and nst1nst2 mutants). The research hypothesizes and demonstrates a biomechanical mechanism for anther opening, which appears to be conserved in many other biological situations where tissue movement occurs. PMID:22998410

  16. Dehydration in the tropical tropopause layer: A possible sink of inorganic bromine?

    NASA Astrophysics Data System (ADS)

    Aschmann, J.; Sinnhuber, B.-M.

    2012-04-01

    Recent studies have shown the importance of bromine very short-lived substances (VSLS) for the stratospheric bromine budget and their potential impact on ozone depletion. In this study, bromine loading in the tropical upper troposphere/lower stratosphere (UTLS) due to VSLS is investigated with a 3D chemical transport model with a detailed chemistry scheme, including parametrizations of particle adsorption and scavenging as well as heterogeneous reactions on corresponding surfaces. On the source gas side, the long-lived halons and methyl bromide and the two most important bromine short-lived substances, bromoform and dibromomethane, are included. On the other hand, the partitioning of inorganic bromine product gases (Bry) is also explicitly calculated. Our results suggest that loss of soluble inorganic bromine in the tropical UTLS due to dehydration is negligible, in contrast to most earlier studies. The main reasons can be summarized as follows: The majority of bromine short-lived source gases is still intact at the UTLS and is therefore not susceptible to dehydration. Furthermore, the fraction of inorganic bromine which is actually adsorbed on ice particles is generally lower than 25%. Finally, the model shows that the small amount of adsorbed bromine that could be scavenged is released efficiently into gas phase by heterogeneous reactions.

  17. Studies on Osmo-air dehydration of different Indian apricot (Prunus armeniaca L.) cultivars.

    PubMed

    Raj, Dev; Sharma, P C; Sharera, Sanjay K

    2015-06-01

    Suitability of seven cultivars of apricot viz. New Castle, Kaisha, Royal, Suffaida, Nari, Kullu (Local) and Chulli (wild apricot) was evaluated for dehydration. Osmotic dehydration of fruits consisting of dipping prepared fruits in 70° Brix sucrose syrup containing 2,000 ppm potassium metabisulphite (KMS) for 24 h followed by cabinet air drying (55 °C) to desired moisture (20 ± 0.5 %) gave better dried product with good colour and appeal. Dried whole or halved fruits after removal of stones were preferred over whole fruits with stones with respect to appearance, texture and overall acceptability. Among different cultivars of apricot; cv. Kaisha followed by New Castle were found better with respect to yield as well as quality of dried product. Further, the quality of the osmo-air dried wild apricot fruits was found statistically at par with the quality of the osmo-air dried product obtained from cultivated apricots. Therefore, wild apricot fruits can also be utilized for preparation of acceptable quality of dried product. PMID:26028764

  18. Lamellar spacing of photosystem II membrane fragments upon dehydration studied by neutron membrane diffraction

    NASA Astrophysics Data System (ADS)

    Pieper, Jörg; Rusevich, Leonid; Hauß, Thomas; Renger, Gernot

    2016-02-01

    The effect of dehydration on the lamellar spacing of photosystem II (PS II) membrane fragments from spinach has been investigated using neutron membrane diffraction at room temperature. The diffraction data reveal a major peak at a scattering vector Q of 0.049 Å-1 at a relative humidity (r.h.) of 90% corresponding to a repeat distance D of about 129 Å. Upon dehydration to 44% r.h., this peak shifts to about 0.060 Å-1 corresponding to a distance of 104.7±2.5 Å. Within experimental error, the latter repeat distance remains almost the same at hydration levels below 44% r.h. indicating that most of the hydration water is removed. This result is consistent with the earlier finding that hydration-induced conformational protein motions in PS II membrane fragments are observed above 44% r.h. and correlated with the onset electron transfer in PS II (Pieper et al. 2008, Eur. Biophys. J. 37: 657-663).

  19. Lamellar spacing of photosystem II membrane fragments upon dehydration studied by neutron membrane diffraction

    NASA Astrophysics Data System (ADS)

    Pieper, Jörg; Rusevich, Leonid; Hauß, Thomas; Renger, Gernot

    2015-12-01

    The effect of dehydration on the lamellar spacing of photosystem II (PS II) membrane fragments from spinach has been investigated using neutron membrane diffraction at room temperature. The diffraction data reveal a major peak at a scattering vector Q of 0.049 Å-1 at a relative humidity (r.h.) of 90% corresponding to a repeat distance D of about 129 Å. Upon dehydration to 44% r.h., this peak shifts to about 0.060 Å-1 corresponding to a distance of 104.7±2.5 Å. Within experimental error, the latter repeat distance remains almost the same at hydration levels below 44% r.h. indicating that most of the hydration water is removed. This result is consistent with the earlier finding that hydration-induced conformational protein motions in PS II membrane fragments are observed above 44% r.h. and correlated with the onset electron transfer in PS II (Pieper et al. 2008, Eur. Biophys. J. 37: 657-663).

  20. Dehydration of fructose to 5-hydroxymethylfurfural in sub-critical water over heterogeneous zirconium phosphate catalysts.

    PubMed

    Asghari, Feridoun Salak; Yoshida, Hiroyuki

    2006-10-16

    Dehydration of fructose to 5-hydroxymethylfurfural in a batch-type process with sub-critical water (sub-CW) was performed in the presence of different laboratory-made zirconium phosphate solid acids at 240 degrees C. A direct relation was found between increasing the crystallinity and decreasing the surface area of solid acids. However, irrespective of the different surface areas, similar catalytic behaviors were observed. Meanwhile, calcination of the samples showed no improvement in the activity of the solid acids. In the presence of the amorphous form of zirconium phosphate, about 80% of fructose was decomposed in sub-critical water at 240 degrees C after 120 s, and the selectivity of the dehydration reaction of fructose to 5-hydroxymethylfurfural rose to 61%. No rehydration products were identified. Soluble polymers and furaldehyde were the only major and minor side products found, respectively. Finally it was found that zirconium phosphate solid acids were stable under sub-CW conditions, and they can easily be recovered without changing their catalytic properties. PMID:16870164

  1. Assessment of the remineralization in simulated enamel lesions via dehydration with near-IR reflectance imaging

    NASA Astrophysics Data System (ADS)

    Lee, Robert C.; Darling, Cynthia L.; Fried, Daniel

    2015-02-01

    Previous studies have demonstrated that near-IR imaging can be used to nondestructively monitor the severity of enamel lesions. Arrested lesions typically have a highly mineralized surface layer that reduces permeability and limits diffusion into the lesion. The purpose of this study was to investigate whether the rate of water loss correlates with the degree of remineralization using near-IR reflectance imaging. Artificial bovine (n=15) enamel lesions were prepared by immersion in a demineralization solution for 24 hours and they were subsequently placed in an acidic remineralization solution for different periods. The samples were dehydrated using an air spray for 30 seconds and surfaces were imaged using an InGaAs camera at 1300-1700 nm wavelengths. Near-IR reflectance intensity differences before and after dehydration decreased with longer periods of remineralization. This study demonstrated that near-IR reflectance imaging was suitable for the detection of remineralization in simulated caries lesions and near-IR wavelengths longer than 1400 nm are well suited for the assessment of remineralization.

  2. [Effect of a dehydrated extract of nopal (Opuntia ficus indica Mill.) on blood glucose].

    PubMed

    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. PMID:2561256

  3. Drinking induced by cellular dehydration in the quail, Coturnix coturnix japonica.

    PubMed

    Takei, Y; Okawara, Y; Kobayashi, H

    1988-01-01

    1. Drinking was induced in water-replete quail 5-10 min after intravenous injection of hypertonic NaCl (0.69 osmol/l) or sucrose (1.06 osmol/l), but hypertonic urea (2.78 osmol/l) failed to induce drinking. 2. The birds drank approximately the amount required to dilute the injected solutes to isotonicity for each given dose of NaCl or sucrose. 3. The plasma angiotensin II level decreased after injection of 7% NaCl (2.5 osmol/l), but it increased after injection of an equi-osmolar solution of sucrose (65%). 4. Plasma osmolality and Na+ concentration returned quickly to control levels, and then decreased further, after injection of 7% NaCl or 65% sucrose. 5. Blood volume and blood pressure increased immediately after injection of 7% NaCl or 65% sucrose. 6. These results show that drinking is induced after injection of hypertonic solutions exclusively by cellular dehydration, and other regulatory mechanisms for thirst, such as extracellular dehydration and the renin-angiotensin system, are rather inhibitory after injection of hypertonic NaCl. PMID:2900120

  4. Slab melting beneath the Cascades Arc driven by dehydration of altered oceanic peridotite

    USGS Publications Warehouse

    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.

  5. Strain rate and shear stress at the grain scale generated during near equilibrium antigorite dehydration

    NASA Astrophysics Data System (ADS)

    Padrón-Navarta, José Alberto; Tommasi, Andréa; Garrido, Carlos J.; Mainprice, David; Clément, Maxime

    2016-04-01

    Dehydration reactions are an outstanding case of mineral replacement reactions because they produce a significant transient fluid-filled porosity. Because fluids are present, these reactions occur by interface-coupled dissolution-precipitation. Under poorly drained conditions corresponding to foliated metamorphic rocks, they generate fluid pressure gradients that evolve in time and space eventually controlling fluid migration [1]. Despite the general agreement on this fact, we still lack of a precise knowledge of the complex coupling between the stresses generated during the reaction and the timescales for mineral growth and how they ultimate control the rate of fluid migration. Constraining these rates is challenge because the timescales of the feedback between fluid flow and mineral growth rates at near equilibrium are beyond the current experimental capabilities. For instance, numerical simulations suggest that the draining times of a dehydration front by compaction are in the order of 10-100 ky [1] difficult to translate into experimental strain rates. On the other hand, the natural record of dehydration reaction might potentially provide unique constrains on this feedback, but we need to identify microstructures related to compaction and quantify them. Features interpreted as due to compaction have been identified in a microstructural study [2] of the first stages of the antigorite dehydration at high-pressure conditions in Cerro del Almirez, Spain (ca. 1.6-1.9 GPa and 630-710 ° C). Compaction features can be mostly observed in the metamorphic enstatite in the form of (1) gradual crystallographic misorientation (up to 16°) of prismatic crystals due to buckling, (3) localized orthoenstatite(Pbca)/low clinoenstatite (P21/c) inversion (confirmed optically and by means of Electron Backscattered Diffraction) and (4) brittle fracturing of prismatic enstatite wrapped by plastically deformed chlorite. The coexistence of enstatite buckling and clinoenstatite lamellae

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

    NASA Astrophysics Data System (ADS)

    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

  7. Concentration-dependent suppressive effect of shrimp head protein hydrolysate on dehydration-induced denaturation of lizardfish myofibrils.

    PubMed

    Ruttanapornvareesakul, Yaowalux; Ikeda, Misako; Hara, Kenji; Osatomi, Kiyoshi; Osako, Kazufumi; Kongpun, Orawan; Nozaki, Yukinori

    2006-03-01

    To utilize fishery waste products as functional food material, the shrimp head protein hydrolysate (SHPH) was produced from three species of shrimp wastes, Northern pink shrimp, Endeavour shrimp and black tiger shrimp, by enzymatic hydrolysis. The SHPH was used as a natural food preservative by adding to lizardfish myofibrils at concentrations ranging from 2.5% to 10%. Their effects on the state of water and the denaturation of myofibrils during dehydration were evaluated. The amount of monolayer and multilayer water in myofibrils containing SHPH were higher than those without SHPH (control). DSC analyses revealed that the amount of unfrozen water increased significantly after addition of SHPH. The Ca-ATPase inactivation rate of myofibrils containing SHPH decreased during dehydration while 5-7.5% concentrations of SHPH exhibited optimum effect regardless of the species. The results implicated that SHPH can be used as an alternative food preservative for suppressive the dehydration-induced denaturation of myofibrils. PMID:16324842

  8. High-temperature dehydration of talc: a kinetics study using in situ X-ray powder diffraction

    NASA Astrophysics Data System (ADS)

    Wang, Duojun; Yi, Li; Huang, Bojin; Liu, Chuanjiang

    2015-06-01

    High-temperature in situ X-ray powder diffraction patterns were used to study the dehydration kinetics of natural talc with a size of 10-15 µm. The talc was annealed from 1073 to 1223 K, and the variations in the characteristic peaks corresponding to talc with the time were recorded to determine the reaction progress. The decomposition of talc occurred, and peaks corresponding to talc and peaks corresponding to enstatite and quartz were observed. The enstatite and talc exhibited a topotactic relationship. The dehydration kinetics of talc was studied as a function of temperature between 1073 and 1223 K. The kinetics data could be modeled using an Avrami equation that considers nucleation and growth processes ? where n varies from 0.4 to 0.8. The rate constant (k) equation for the natural talc is ? The reaction mechanism for the dehydration of talc is a heterogeneous nucleation and growth mechanism.

  9. A specific group of genes respond to cold dehydration stress in cut Alstroemeria flowers whereas ambient dehydration stress accelerates developmental senescence expression patterns

    PubMed Central

    Wagstaff, Carol; Bramke, Irene; Breeze, Emily; Thornber, Sarah; Harrison, Elizabeth; Thomas, Brian; Buchanan-Wollaston, Vicky; Stead, Tony; Rogers, Hilary

    2010-01-01

    Petal development and senescence entails a normally irreversible process. It starts with petal expansion and pigment production, and ends with nutrient remobilization and ultimately cell death. In many species this is accompanied by petal abscission. Post-harvest stress is an important factor in limiting petal longevity in cut flowers and accelerates some of the processes of senescence such as petal wilting and abscission. However, some of the effects of moderate stress in young flowers are reversible with appropriate treatments. Transcriptomic studies have shown that distinct gene sets are expressed during petal development and senescence. Despite this, the overlap in gene expression between developmental and stress-induced senescence in petals has not been fully investigated in any species. Here a custom-made cDNA microarray from Alstroemeria petals was used to investigate the overlap in gene expression between developmental changes (bud to first sign of senescence) and typical post-harvest stress treatments. Young flowers were stressed by cold or ambient temperatures without water followed by a recovery and rehydration period. Stressed flowers were still at the bud stage after stress treatments. Microarray analysis showed that ambient dehydration stress accelerates many of the changes in gene expression patterns that would normally occur during developmental senescence. However, a higher proportion of gene expression changes in response to cold stress were specific to this stimulus and not senescence related. The expression of 21 transcription factors was characterized, showing that overlapping sets of regulatory genes are activated during developmental senescence and by different stresses. PMID:20457576

  10. A specific group of genes respond to cold dehydration stress in cut Alstroemeria flowers whereas ambient dehydration stress accelerates developmental senescence expression patterns.

    PubMed

    Wagstaff, Carol; Bramke, Irene; Breeze, Emily; Thornber, Sarah; Harrison, Elizabeth; Thomas, Brian; Buchanan-Wollaston, Vicky; Stead, Tony; Rogers, Hilary

    2010-06-01

    Petal development and senescence entails a normally irreversible process. It starts with petal expansion and pigment production, and ends with nutrient remobilization and ultimately cell death. In many species this is accompanied by petal abscission. Post-harvest stress is an important factor in limiting petal longevity in cut flowers and accelerates some of the processes of senescence such as petal wilting and abscission. However, some of the effects of moderate stress in young flowers are reversible with appropriate treatments. Transcriptomic studies have shown that distinct gene sets are expressed during petal development and senescence. Despite this, the overlap in gene expression between developmental and stress-induced senescence in petals has not been fully investigated in any species. Here a custom-made cDNA microarray from Alstroemeria petals was used to investigate the overlap in gene expression between developmental changes (bud to first sign of senescence) and typical post-harvest stress treatments. Young flowers were stressed by cold or ambient temperatures without water followed by a recovery and rehydration period. Stressed flowers were still at the bud stage after stress treatments. Microarray analysis showed that ambient dehydration stress accelerates many of the changes in gene expression patterns that would normally occur during developmental senescence. However, a higher proportion of gene expression changes in response to cold stress were specific to this stimulus and not senescence related. The expression of 21 transcription factors was characterized, showing that overlapping sets of regulatory genes are activated during developmental senescence and by different stresses. PMID:20457576

  11. Effect of dietary dehydrated pasture and citrus pulp on the performance and meat quality of broiler chickens.

    PubMed

    Mourão, J L; Pinheiro, V M; Prates, J A M; Bessa, R J B; Ferreira, L M A; Fontes, C M G A; Ponte, P I P

    2008-04-01

    Some feedstuffs containing significant levels of fiber may be a good source of bioactive compounds that may contribute to improving broiler meat quality. However, high fiber level can have a negative impact on broiler performance. A study was undertaken to investigate the impact of incorporating citrus pulp (5 or 10%) or dehydrated pasture (5 or 10%) on the performance, carcass yield, and characteristics of broiler chickens. A diet containing neither citrus pulp nor dehydrated pasture was used as control. The results on growth performances showed that daily weight gain was reduced by 26% in birds of the 10% citrus pulp treatment (P<0.05). Compared with the control treatment, increases in feed intake occurred in birds consuming diets with 5 or 10% citrus pulp, which resulted in significantly higher feed conversion rates with the 10% level. Under the same incorporation rate, dehydrated pasture had effects less evident on the performances of broiler chicken. In addition, diets containing citrus pulp, displaying higher percentages of soluble nonstarch polysaccharides, increased small intestine relative length, and reduced carcass yield. Inclusion of 10% dehydrated pasture in diets resulted in improved breast skin yellowness (P<0.05). Finally, the results revealed that incorporation of the nonstarch polysaccharide-rich feedstuffs had a major impact on the fatty acid profile (affected 16 of 21 fatty acids) of broiler meat. Polyunsaturated fatty acids content in meat was higher in birds consuming the highest levels of both citrus pulp and dehydrated pasture, leading to increased ratios of polyunsaturated to saturated fatty acids. Together, the results suggest that incorporation of moderate levels of dehydrated pastures in poultry diets has a minor impact on broiler performance and can contribute significantly to improve breast skin yellowness and fatty acid composition of meat. PMID:18339996

  12. Gene expression and localization of two types of AQP5 in Xenopus tropicalis under hydration and dehydration.

    PubMed

    Shibata, Yuki; Sano, Takahiro; Tsuchiya, Nobuhito; Okada, Reiko; Mochida, Hiroshi; Tanaka, Shigeyasu; Suzuki, Masakazu

    2014-07-01

    Two types of aquaporin 5 (AQP5) genes (aqp-xt5a and aqp-xt5b) were identified in the genome of Xenopus tropicalis by synteny comparison and molecular phylogenetic analysis. When the frogs were in water, AQP-xt5a mRNA was expressed in the skin and urinary bladder. The expression of AQP-xt5a mRNA was significantly increased in dehydrated frogs. AQP-xt5b mRNA was also detected in the skin and increased in response to dehydration. Additionally, AQP-xt5b mRNA began to be slightly expressed in the lung and stomach after dehydration. For the pelvic skin of hydrated frogs, immunofluorescence staining localized AQP-xt5a and AQP-xt5b to the cytoplasm of secretory cells of the granular glands and the apical plasma membrane of secretory cells of the small granular glands, respectively. After dehydration, the locations of both AQPs in their respective glands did not change, but AQP-xt5a was visualized in the cytoplasm of secretory cells of the small granular glands. For the urinary bladder, AQP-xt5a was observed in the apical plasma membrane and cytoplasm of a number of granular cells under normal hydration. After dehydration, AQP-xt5a was found in the apical membrane and cytoplasm of most granular cells. Injection of vasotocin into hydrated frogs did not induce these changes in the localization of AQP-xt5a in the small granular glands and urinary bladder, however. The results suggest that AQP-xt5a might be involved in water reabsorption from the urinary bladder during dehydration, whereas AQP-xt5b might play a role in water secretion from the small granular gland. PMID:24717674

  13. Transport of Antarctic stratospheric strongly dehydrated air into the troposphere observed during the HALO-ESMVal mission 2012

    NASA Astrophysics Data System (ADS)

    Rolf, Christian; Afchine, Armin; Bozem, Heiko; Buchholz, Bernhard; Ebert, Volker; Guggenmoser, Tobias; Hoor, Peter; Konopka, Paul; Kretschmer, Erik; Müller, Stefan; Schlager, Hans; Spelten, Nicole; Suminska-Ebersoldt, Olga; Ungermann, Jörn; Zahn, Andreas; Krämer, Martina

    2015-04-01

    Dehydration in the Antarctic winter stratosphere is a well-known phenomenon and occasionally observed by ballon-borne and satellite measurements. However, in-situ measurements of dehydration in the Antarctic vortex are very rare. Here, we present detailed in-situ observations with the FISH, HAI, FAIRO, TRIHOP, and GLORIA payload aboard the new German aircraft HALO. Strongly dehydrated air masses down to 1.6 ppmv were observed in a region up to 47°S and at 12 to \\unit{13}{ km} altitude only, which has never been observed by satellites before. The dehydration can be traced back to individual ice formation events, where ice crystals sedimented out and water vapor was irreversibly removed. Within these dehydrated stratospheric air masses, filaments of moister air down to the tropopause are detected with the high resolution limb sounder GLORIA. Furthermore, dehydrated air masses are observed with GLORIA in the Antarctic troposphere down to \\unit{7}{ km}. With the help of a backward trajectory analysis, a tropospheric origin of the moist filaments in the vortex can be identified, while the dry air masses in the troposphere have stratospheric origin. The transport pathways of Antarctic stratosphere/troposphere exchange are investigated and the irrelevant role of the Antarctic thermal tropopause as a transport barrier is confirmed. Further, it is shown that the exchange process can be attributed to several successive Rossby wave events in combination with isentropic interchange of air masses crossing the weak tropopause and subsequent subsidence due to radiative cooling. Once transported to the troposphere, air masses are able to reach near surface levels within 1-2 months.

  14. Transport of Antarctic stratospheric strongly dehydrated air into the troposphere observed during the HALO-ESMVal campaign 2012

    NASA Astrophysics Data System (ADS)

    Rolf, C.; Afchine, A.; Bozem, H.; Buchholz, B.; Ebert, V.; Guggenmoser, T.; Hoor, P.; Konopka, P.; Kretschmer, E.; Müller, S.; Schlager, H.; Spelten, N.; Sumińska-Ebersoldt, O.; Ungermann, J.; Zahn, A.; Krämer, M.

    2015-03-01

    Dehydration in the Antarctic winter stratosphere is a well-known phenomenon that is occasionally observed by balloon-borne and satellite measurements. However, in-situ measurements of dehydration in the Antarctic vortex are very rare. Here, we present detailed observations with the in-situ and GLORIA remote sensing instrument payload aboard the new German aircraft HALO. Strongly dehydrated air masses down to 1.6 ppmv of water vapor were observed as far north as 47° S and between 12 and 13 km in altitude, which has never been observed by satellites. The dehydration can be traced back to individual ice formation events, where ice crystals sedimented out and water vapor was irreversibly removed. Within these dehydrated stratospheric air masses, filaments of moister air reaching down to the tropopause are detected with the high resolution limb sounder, GLORIA. Furthermore, dehydrated air masses are observed with GLORIA in the Antarctic troposphere down to 7 km. With the help of a backward trajectory analysis, a tropospheric origin of the moist filaments in the vortex can be identified, while the dry air masses in the troposphere have stratospheric origins. The transport pathways of Antarctic stratosphere/troposphere exchange are investigated and the irrelevant role of the Antarctic thermal tropopause as a transport barrier is confirmed. Further, it is shown that the exchange process can be attributed to several successive Rossby wave events in combination with an isentropic interchange of air masses across the weak tropopause and subsequent subsidence due to radiative cooling. Once transported to the troposphere, air masses with stratospheric origin are able to reach near-surface levels within 1-2 months.

  15. Effect of extract of Withania Somnifera on dehydration-induced oxidative stress-related uremia in male rats.

    PubMed

    Das, Koushik; Samanta, Tanushree Tulsian; Samanta, Pradip; Nandi, Dilip Kumar

    2010-01-01

    Dehydration or water deprivation in the body decreases urinary excretion and allows urea and other protein waste products to accumulate in the blood. The aim of the present study is to evaluate the association of uremia and oxidative stress by applying the herbal plant Withania somnifera (W. somnifera) (Aswagandha). The study was performed on male Wister strain rats in which, dehydration was achieved by water withdrawal. A total of 18 rats were studied and were randomly divided into three Groups: Group-1, control, Group-2, only dehydration and Group-3, dehydration + administration of aqueous root extract of W. somnifera, orally (50 mg/100 gm body weight/day) for 25 days. After 25 days of treatment, it was observed that the body weight of Group-3 animals had increased significantly, while that in Group-2 had decreased significantly. The liver enzymes in both blood and kidneys did not show any significant change in the three groups implying absence of any toxicity of the root extract. In Group-2 animals, the serum urea and creatinine levels increased sig-nificantly when compared with animals in Groups-1 and 3. The low levels of serum urea and crea-tinine in Group-3 animals indicates the protective effect of the plant extract against renal injury caused by dehydration. Dehydration-induced oxidative stress was established in our study by noting the low activities of super-oxide dismutase and catalase, both important antioxidant enzymes, in Group-2 animals; both enzymes were stabilized in animals of Groups-3 and 1. In conclusion, it is hypothesized that there is an antioxidative role of W. somnifera resulting in reducing the extent of renal injury as a result of oxidative stress. PMID:20061697

  16. Functional roles of the pepper RING finger protein gene, CaRING1, in abscisic acid signaling and dehydration tolerance.

    PubMed

    Lim, Chae Woo; Hwang, Byung Kook; Lee, Sung Chul

    2015-09-01

    Plants are constantly exposed to a variety of biotic and abiotic stresses, which include pathogens and conditions of high salinity, low temperature, and drought. Abscisic acid (ABA) is a major plant hormone involved in signal transduction pathways that mediate the defense response of plants to abiotic stress. Previously, we isolated Ring finger protein gene (CaRING1) from pepper (Capsicum annuum), which is associated with resistance to bacterial pathogens, accompanied by hypersensitive cell death. Here, we report a new function of the CaRING1 gene product in the ABA-mediated defense responses of plants to dehydration stress. The expression of the CaRING1 gene was induced in pepper leaves treated with ABA or exposed to dehydration or NaCl. Virus-induced gene silencing of CaRING1 in pepper plants exhibited low degree of ABA-induced stomatal closure and high levels of transpirational water loss in dehydrated leaves. These led to be more vulnerable to dehydration stress in CaRING1-silenced pepper than in the control pepper, accompanied by reduction of ABA-regulated gene expression and low accumulation of ABA and H2O2. In contrast, CaRING1-overexpressing transgenic plants showed enhanced sensitivity to ABA during the seedling growth and establishment. These plants were also more tolerant to dehydration stress than the wild-type plants because of high ABA accumulation, enhanced stomatal closure and increased expression of stress-responsive genes. Together, these results suggest that the CaRING1 acts as positive factor for dehydration tolerance in Arabidopsis by modulating ABA biosynthesis and ABA-mediated stomatal closing and gene expression. PMID:26249046

  17. Diagnostic accuracy of calculated serum osmolarity to predict dehydration in older people: adding value to pathology laboratory reports

    PubMed Central

    Hooper, Lee; Abdelhamid, Asmaa; Ali, Adam; Bunn, Diane K; Jennings, Amy; John, W Garry; Kerry, Susan; Lindner, Gregor; Pfortmueller, Carmen A; Sjöstrand, Fredrik; Walsh, Neil P; Fairweather-Tait, Susan J; Potter, John F; Hunter, Paul R; Shepstone, Lee

    2015-01-01

    Objectives To assess which osmolarity equation best predicts directly measured serum/plasma osmolality and whether its use could add value to routine blood test results through screening for dehydration in older people. Design Diagnostic accuracy study. Participants Older people (≥65 years) in 5 cohorts: Dietary Strategies for Healthy Ageing in Europe (NU-AGE, living in the community), Dehydration Recognition In our Elders (DRIE, living in residential care), Fortes (admitted to acute medical care), Sjöstrand (emergency room) or Pfortmueller cohorts (hospitalised with liver cirrhosis). Reference standard for hydration status Directly measured serum/plasma osmolality: current dehydration (serum osmolality >300 mOsm/kg), impending/current dehydration (≥295 mOsm/kg). Index tests 39 osmolarity equations calculated using serum indices from the same blood draw as directly measured osmolality. Results Across 5 cohorts 595 older people were included, of whom 19% were dehydrated (directly measured osmolality >300 mOsm/kg). Of 39 osmolarity equations, 5 showed reasonable agreement with directly measured osmolality and 3 had good predictive accuracy in subgroups with diabetes and poor renal function. Two equations were characterised by narrower limits of agreement, low levels of differential bias and good diagnostic accuracy in receiver operating characteristic plots (areas under the curve >0.8). The best equation was osmolarity=1.86×(Na++ K+)+1.15×glucose+urea+14 (all measured in mmol/L). It appeared useful in people aged ≥65 years with and without diabetes, poor renal function, dehydration, in men and women, with a range of ages, health, cognitive and functional status. Conclusions Some commonly used osmolarity equations work poorly, and should not be used. Given costs and prevalence of dehydration in older people we suggest use of the best formula by pathology laboratories using a cutpoint of 295 mOsm/L (sensitivity 85%, specificity 59%), to report

  18. Assembly of light-emitting diode based on hydrophilic CdTe quantum dots incorporating dehydrated silica gel.

    PubMed

    Du, Jinhua; Wang, Chunlei; Xu, Xiaojing; Wang, Zhuyuan; Xu, Shuhong; Cui, Yiping

    2016-03-01

    Stable photoluminescence QD light-emitting diodes (QD-LEDs) were made based on hydrophilic CdTe quantum dots (QDs). A quantum dot-inorganic nanocomposite (hydrophilic CdTe QDs incorporating dehydrated silica gel) was prepared by two methods (rotary evaporation and freeze drying). Taking advantage of its viscosity, plasticity and transparency, dehydrated silica gel could be coated on the surface of ultraviolet (UV) light LEDs to make photoluminescence QD-LEDs. This new photoluminescence QD-LED, which is stable, environmentally non-toxic, easy to operate and low cost, could expand the applications of hydrophilic CdTe QDs in photoluminescence. PMID:26199049

  19. The reaction mechanism for dehydration process catalyzed by type I dehydroquinate dehydratase from Gram-negative Salmonella enterica

    NASA Astrophysics Data System (ADS)

    Yao, Yuan; Li, Ze-Sheng

    2012-01-01

    The fundamental reaction mechanism for the dehydration process catalyzed by type I dehydroquinate dehydratase from Gram-negative Salmonella enterica has been studied by density functional theory calculations. The results indicate that the dehydration process undergoes a two-step cis-elimination mechanism, which is different from the previously proposed one. The catalytic roles of both the highly conserved residue His143 and the Schiff base formed between the substrate and Lys170 have also been elucidated. The structural and mechanistic insight presented here may direct the design of type I dehydroquinate dehydratase enzyme inhibitors as non-toxic antimicrobials, anti-fungals, and herbicides.

  20. Baclofen into the lateral parabrachial nucleus induces hypertonic sodium chloride intake during cell dehydration

    PubMed Central

    2013-01-01

    Background Activation of GABAB receptors with baclofen into the lateral parabrachial nucleus (LPBN) induces ingestion of water and 0.3 M NaCl in fluid replete rats. However, up to now, no study has investigated the effects of baclofen injected alone or combined with GABAB receptor antagonist into the LPBN on water and 0.3 M NaCl intake in rats with increased plasma osmolarity (rats treated with an intragastric load of 2 M NaCl). Male Wistar rats with stainless steel cannulas implanted bilaterally into the LPBN were used. Results In fluid replete rats, baclofen (0.5 nmol/0.2 μl), bilaterally injected into the LPBN, induced ingestion of 0.3 M NaCl (14.3 ± 4.1 vs. saline: 0.2 ± 0.2 ml/210 min) and water (7.1 ± 2.9 vs. saline: 0.6 ± 0.5 ml/210 min). In cell-dehydrated rats, bilateral injections of baclofen (0.5 and 1.0 nmol/0.2 μl) into the LPBN induced an increase of 0.3 M NaCl intake (15.6 ± 5.7 and 21.5 ± 3.5 ml/210 min, respectively, vs. saline: 1.7 ± 0.8 ml/210 min) and an early inhibition of water intake (3.5 ± 1.4 and 6.7 ± 2.1 ml/150 min, respectively, vs. saline: 9.2 ± 1.4 ml/150 min). The pretreatment of the LPBN with 2-hydroxysaclofen (GABAB antagonist, 5 nmol/0.2 μl) potentiated the effect of baclofen on 0.3 M NaCl intake in the first 90 min of test and did not modify the inhibition of water intake induced by baclofen in cell-dehydrated rats. Baclofen injected into the LPBN did not affect blood pressure and heart rate. Conclusions Thus, injection of baclofen into the LPBN in cell-dehydrated rats induced ingestion of 0.3 M NaCl and inhibition of water intake, suggesting that even in a hyperosmotic situation, the blockade of LPBN inhibitory mechanisms with baclofen is enough to drive rats to drink hypertonic NaCl, an effect independent of changes in blood pressure. PMID:23642235

  1. Experimental study of trace element release during ultrahigh-pressure serpentinite dehydration

    NASA Astrophysics Data System (ADS)

    Spandler, Carl; Pettke, Thomas; Hermann, Joerg

    2014-04-01

    Subduction of serpentinite is envisaged to play a key role in volatile and element recycling at convergent plate margins, but there is currently little known about the composition of the fluid phase(s) released by devolatilisation of deeply subducted serpentinite. We have performed a series of ultrahigh pressure experiments to examine the phase relations and fluid compositions produced by reaction of a natural serpentinite under sub-arc conditions. We employ a novel technique of forming synthetic fluid inclusions in olivine at run conditions to preserve samples of experimental fluids for subsequent analysis. Our experiments confirm that the breakdown of antigorite and chlorite are the most important fluid-producing reactions from serpentinite at sub-arc depths. For our low CaO/Al2O3 peridotitic composition at 3.5 to 4.0 GPa we find that clinopyroxene reacts out below 750 °C and chlorite breaks down progressively between 700 and 800 °C to form garnet harzburgite. Raman analysis of synthetic fluid inclusions indicates that all experiments contained a single aqueous fluid phase, which - together with a lack of textural or mineralogical evidence for hydrous melting - indicates that the water-saturated solidus for our starting composition is above 900 °C at 4.0 GPa. Element concentrations in the fluid for three experiments were determined in situ via laser ablation ICP-MS of individual fluid inclusions. In general, the fluids are enriched in trace elements compared to the bulk starting material, but particularly so for Li, B, LILE, LREE, and U. Chlorite dehydration fluids have high Li/B, LREE/HREE and Ce/Y due to retention of some B in olivine, and retention of Y and HREE in garnet. Our results indicate that fluids produced by serpentinite dehydration at sub-arc depths may carry some of the slab-derived trace elements required for arc magmatism, and may fractionate key trace element ratios in the dehydrated residues, which in turn may ultimately contribute to the

  2. Deep-level magma dehydration and ascent rates at Mt. Etna (Sicily, Italy)

    NASA Astrophysics Data System (ADS)

    Armienti, P.; Perinelli, C.; Putirka, K.

    2012-04-01

    Magma ascent velocity, v (dH/dt; H = depth, t = time),can be determined from ascent rate (dP/dt), and rate of cooling (dT/dt): v= 1/(rgpg) (dP/dT)(dT/dt) where r is magma density, P is pressure, T is temperature and g is the acceleration of gravity. This equation for v provides a key to investigating the relationships between initial ascent rate of magma and the depths of magma dehydration, and v can be calculated using pressure and temperature (P - PH2O - T) estimates from mineral-liquid thermobarometry, and cooling rates inferred from Crystal Size Distribution (CSD) theory. For recent Mt. Etna lava flows, both dP/dT and dT/dt have been well characterized based, respectively, on clinopyroxene thermobarometry, and clinopyroxene CSDs (the latter yields dT/dt = 2x10-6 °C/s). Deep-level (>20 km) magma ascent rates range from practically 0 (where clinopyroxene P - T estimates form a cluster, and so dP/dT ≈ 0), to about 10 m/hr for flows that yield very steep P - T trajectories. Many lava flows at Mt. Etna yield P - T paths that follow a hydrous (about 3% water) clinopyroxene saturation surface, which closely approximates water contents obtained from melt inclusions. Independent assessments of deep level water content yield ascent rates of ~1 m/hr, in agreement with the slowest rates derived for magma effusion or vapor-driven ascent (~0.001 to >0.2 m/s, or 3.6 to 720 m/hr). Changes in P - T slopes, as obtained by pyroxene thermobarometry, indicate an upward acceleration of magma, which may be due to the onset of deep-level magma dehydration linked to the non-ideal behavior of water and CO2 mixtures that induce a deep-level maximum of water loss at P ≈ 0.4 MPa at T ≈ 1200 ° C for a CO2 content >1000ppm. Melt inclusion data on CO2 and H2O contents are successfully reproduced and interpreted in a context of magma dehydration induced by a CO2 flux possibly deriving by decarbonation reaction of the carbonate fraction of the Capo D'Orlando flysch.

  3. Seed dehydration and the establishment of desiccation tolerance during seed maturation is altered in the Arabidopsis thaliana mutant atem6-1

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The end of orthodox seed development is typified by a developmentally regulated period of dehydration leading to the loss of bulk water from the entire structure. When dehydration occurs, the cytoplasm condenses and intracellular components become more crowded, providing an environment amenable to ...

  4. Pathways for Ethanol Dehydrogenation and Dehydration Catalyzed by Ceria (111) and (100) Surfaces

    SciTech Connect

    Beste, Ariana; Steven Overbury

    2015-01-08

    We have performed computations to better understand how surface structure affects selectivity in dehydrogenation and dehydration reactions of alcohols. Ethanol reactions on the (111) and (100) ceria surfaces were studied starting from the dominant surface species, ethoxy. We used DFT (PBE+U) to explore reaction pathways leading to ethylene and acetaldehyde and calculated estimates of rate constants employing transition state theory. To assess pathway contributions, we carried out kinetic analysis. Our results show that intermediate and transition state structures are stabilized on the (100) surface compared to the (111) surface. Formation of acetaldehyde over ethylene is kinetically and thermodynamically preferred on both surfaces. Our results are consistent with temperature programmed surface reaction and steady-state experiments, where acetaldehyde was found as the main product and evidence was presented that ethylene formation at higher temperature originates from changes in adsorbate and surface structure.

  5. Hydrated Salts: Dehydration, Dissolution, and Incongruent Melting In Terrestrial Evaporites and at Meridiani Planum, Mars

    NASA Astrophysics Data System (ADS)

    Kargel, J. S.; Dougherty, A.; Feldman, W.; Hogenboom, D.; Marion, G.; McCarthy, C.; Prieto-Ballesteros, O.

    2004-12-01

    The Opportunity rover and orbital observations of Meridiani Planum (Mars) have revealed much about the region's stratigraphy, chemistry, sedimentology, and mineralogy of what appears to be a layered lacustrine sedimentary sequence, including chemical sediments deposited by evaporative or freezing processes in a large, saline lake or sea. The roles of evaporation versus freezing are not clearly elucidated in the data, but both freezing and evaporation are likely on Mars for any paleoclimate scenario that minimizes excursions from current climate. The rock sequences reveal many interesting features reported in press accounts, NASA press releases, and in conference presentations by the MER science teams. The topic dealt with here concerns indirect sedimentologic indications of phase changes that seem to have generated negative volume changes due to dehydration, dissolution, and/or annealing. These indicators include microkarstic and polygonal structures in the laminated chemical sediments. These processes have operated on a small scale at Meridiani Planum, and serve as possible analogs for processes operative on mega scales elsewhere on Mars. Comparable processes are common in terrestrial evaporite basins and in sequences of evaporitic rocks. Fluctuations of mineral water content drive large changes in volume and pore fluid pressure, and these exert stresses that can drive extensional fracturing and faulting, folding, thrusting, and diapirism. These processes may be even more important on Mars than on Earth, because on Mars solid salts may be more abundant, more widespread, and subject to larger ranges of hydration states; the effects of these processes may be better preserved for lack of erasure by fluvial erosional processes and other degradational processes on Earth's more active surface. Specific processes and reactions proposed here can account for the sedimentologic structures observed at Meridiani Planum based on aqueous chemical phase equilibria and phase

  6. Impact induced dehydration of serpentine and the evolution of planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Lange, M. A.; Ahrens, T. J.

    1982-01-01

    Results of shock recovery experiments carried out on antigorite serpentine Mg3Si2O5(OH)4 are reported. The main objective of the present study is the determination of critical shock pressures for partial and complete dehydration of serpentine under shock loading. It is pointed out that serpentine and serpentine-like layer silicates are the major water-bearing phases in carbonaceous chondrites. It appears that these minerals, and a poorly defined cometary contribution, were the most likely water-bearing phases in accreting planetesimals which led to the formation of the terrestrial planets. The obtained results imply that the process of impact induced devolatilization of volatile bearing minerals during accretion is likely to have occurred on earth. The findings lend support to the model of a terrestrial atmosphere/hydrosphere forming during the later stages of accretion of the earth.

  7. Efficient dehydration of fructose to 5-hydroxymethylfurfural catalyzed by a recyclable sulfonated organic heteropolyacid salt.

    PubMed

    Qu, Yongshui; Huang, Chongpin; Zhang, Jie; Chen, Biaohua

    2012-02-01

    The dehydration of fructose to 5-hydroxymethylfurfural (5-HMF) with room temperature ionic liquids (ILs) is a way of producing liquid fuels from renewable resources, but separation of products and IL is energy intensive. In this work, a heteropolyacid salt of an IL-forming cation functionalized with a propanesulfonate group, 1-(3-sulfonicacid)propyl-3-methyl imidazolium phosphotungstate ([MIMPS](3)PW(12)O(40)), was used as a catalyst-rather than as a solvent-in the conversion of fructose to 5-HMF. The maximum yield of 5-HMF was 99.1% at 120°C after 2h using sec-butanol as solvent, and the catalyst was separated from the reaction mixture by a simple process at the end of the reaction and reused six times without loss of activity. PMID:22201545

  8. Nitric Acid Dehydration Using Perfluoro Carboxylate and Mixed Sulfonate/Carboxylate Membranes

    SciTech Connect

    R.L. Ames

    2004-09-01

    Perfluoro ionomer membranes are tetrafluoro ethylene-based materials with microheterogeneous structures consisting of a hydrophobic polymer backbone and a hydrophilic side-chain cluster region. Due to the ionomer cluster morphology, these films exhibit unique transport properties. Recent investigations with perfluoro sulfonate and perfluoro sulfonate/carboxylate composite polymers have demonstrated their value in the dehydration of nitric acid and they show potential as an alternative to conventional, energy intensive unit operations in the concentration of acid feeds. As a result, investigations were conducted to determine the feasibility of using pure perfluoro carboxylate and mixed perfluoro sulfonate/carboxylate films for the dehydration of nitric acid because of the speculation of improved water selectivity of the carboxylate pendant chain. During the first phase of these investigations the effort was focused on generating a thin, solution cast perfluoro carboxylate ionomer film, to evaluate the general, chemical and physical characteristics of the polymer, and to assess the material's aqueous transport performance (flux and nitrate separation efficiencies) in pervaporation and high-pressure environments. Results demonstrated that generating robust solution-cast films was difficult yet a number of membranes survived high trans-membrane pressures up to 700 psig. General characterization of the solution cast product showed reduced ion exchange capacities when compared with thicker, ''as received'' perfluoro carboxylate and similar sulfonate films. Small angle x-ray scattering analysis results suggested that the solution cast carboxylate films contained a small fraction of sulfonate terminated side-chains. Aqueous transport experimentation showed that permeate fluxes for both pure water and nitric acid were approximately two orders of magnitude smaller for the carboxylate solution cast membranes when compared to their sulfonate counterparts of similar thickness

  9. Pathways for Ethanol Dehydrogenation and Dehydration Catalyzed by Ceria (111) and (100) Surfaces

    DOE PAGESBeta

    Beste, Ariana; Steven Overbury

    2015-01-08

    We have performed computations to better understand how surface structure affects selectivity in dehydrogenation and dehydration reactions of alcohols. Ethanol reactions on the (111) and (100) ceria surfaces were studied starting from the dominant surface species, ethoxy. We used DFT (PBE+U) to explore reaction pathways leading to ethylene and acetaldehyde and calculated estimates of rate constants employing transition state theory. To assess pathway contributions, we carried out kinetic analysis. Our results show that intermediate and transition state structures are stabilized on the (100) surface compared to the (111) surface. Formation of acetaldehyde over ethylene is kinetically and thermodynamically preferred onmore » both surfaces. Our results are consistent with temperature programmed surface reaction and steady-state experiments, where acetaldehyde was found as the main product and evidence was presented that ethylene formation at higher temperature originates from changes in adsorbate and surface structure.« less

  10. Improved noncontact optical sensor for detection of glucose concentration and indication of dehydration level

    PubMed Central

    Ozana, Nisan; Arbel, Nadav; Beiderman, Yevgeny; Mico, Vicente; Sanz, Martin; Garcia, Javier; Anand, Arun; Javidi, Baharam; Epstein, Yoram; Zalevsky, Zeev

    2014-01-01

    The ability to extract different bio-medical parameters from one single wristwatch device can be very applicable. The wearable device that is presented in this paper is based on two optical approaches. The first is the extraction and separation of remote vibration sources and the second is the rotation of linearly polarized light by certain materials exposed to magnetic fields. The technique is based on tracking of temporal changes of reflected secondary speckles produced in the wrist when being illuminated by a laser beam. Change in skin’s temporal vibration profile together with change in the magnetic medium that is generated by time varied glucose concentration caused these temporal changes. In this paper we present experimental tests which are the first step towards an in vivo noncontact device for detection of glucose concentration in blood. The paper also shows very preliminary results for qualitative capability for indication of dehydration. PMID:24940550

  11. Synthesis and characterization of biopolymer based mixed matrix membranes for pervaporative dehydration.

    PubMed

    Das, Paramita; Ray, Samit Kumar

    2014-03-15

    Several blend membranes were prepared from different weight ratios of polyvinyl alcohol (PVA) and hydroxyethyl cellulose (HEC) and these unfilled membranes were crosslinked with maleic acid. In a similar way mixed matrix blend membranes were also prepared by varying weight ratio of PVA and HEC with micro and nano bentonite filler in each of these blends. These membranes were used for pervaporative dehydration of 89 wt% tetrahydrofuran (THF). Three membranes designated as UF (unfilled), MF2 (containing 2 wt% micro filler) and NF2 (containing 2 wt% nano filler) showing the best results for flux and selectivity were identified. These membranes were characterized by FTIR, UV, XRD and DTA-TG and used for separation of 80-99 wt% THF from water by pervaporation. The NF2 membrane was found to show the best results in terms of flux and separation factor. PMID:24528730

  12. Effects of Sugars on Lipid Bilayers during Dehydration − SAXS/WAXS Measurements and Quantitative Model

    SciTech Connect

    Lenne, Thomas; Garvey, Christopher J.; Koster, Karen L.; Bryant, Gary

    2009-04-02

    We present an X-ray scattering study of the effects of dehydration on the bilayer and chain-chain repeat spacings of dipalmitoylphosphatidylcholine bilayers in the presence of sugars. The presence of sugars has no effect on the average spacing between the phospholipid chains in either the fluid or gel phase. Using this finding, we establish that for low sugar concentrations only a small amount of sugar exclusion occurs. Under these conditions, the effects of sugars on the membrane transition temperatures can be explained quantitatively by the reduction in hydration repulsion between bilayers due to the presence of the sugars. Specific bonding of sugars to lipid headgroups is not required to explain this effect.

  13. Pressure-induced dehydration and the structure of ammonia hemihydrate-II

    NASA Astrophysics Data System (ADS)

    Wilson, C. W.; Bull, C. L.; Stinton, G.; Loveday, J. S.

    2012-03-01

    The structure of the crystalline ammonia-bearing phase formed when ammonia monohydrate liquid is compressed to 3.5(1) GPa at ambient temperature has been solved from a combination of synchrotron x-ray single-crystal and neutron powder-diffraction studies. The solution reveals that rather than having the ammonia monohydrate (AMH) composition as had been previously thought, the structure has an ammonia hemihydrate composition. The structure is monoclinic with spacegroup P21/c and lattice parameters a = 3.3584(5) Å, b = 9.215(1) Å, c = 8.933(1) Å and β = 94.331(8)° at 3.5(1) GPa. The atomic arrangement has a crowned hexagonal arrangement and is a layered structure with long N-D⋯N hydrogen bonds linking the layers. The existence of pressure-induced dehydration of AMH may have important consequences for the behaviour and differentiation of icy planets and satellites.

  14. Effects of pretreatments on the diffusion kinetics and some quality parameters of osmotically dehydrated apple slices.

    PubMed

    Taiwo, K A; Angersbach, A; Ade-Omowaye, B I; Knorr, D

    2001-06-01

    This study compared mass transfer during osmotic dehydration (OD) and some quality indices of untreated apple slices to those of apple slices pretreated by either blanching, freezing, or applying high-intensity electric field pulses (HELP) or high pressure (HP). HP, HELP, and blanching increased water loss. Untreated and HELP-treated samples had comparable solids gains, which were lower (P < 0.05) than in the other samples. Apple slices turned brown after pretreatment but the L values of these samples increased with OD. The breaking force of dried samples increased with OD time, and pretreated samples had firmer dried texture than the untreated. Vitamin C content decreased with OD time, but HP- and HELP-treated apples had better retention of vitamin C. PMID:11409969

  15. Reversible emission evolution from Ag activated zeolite Na-A upon dehydration/hydration

    SciTech Connect

    Lin, Hui E-mail: fujii@eedept.kobe-u.ac.jp; Imakita, Kenji; Fujii, Minoru E-mail: fujii@eedept.kobe-u.ac.jp

    2014-11-24

    Reversible emission evolution of thermally treated Ag activated zeolite Na-A upon dehydration/hydration in vacuum/water vapor was observed. The phenomenon was observed even for the sample with low Ag{sup +}-Na{sup +} exchanging (8.3%), indicating that the emission from Ag activated zeolites may not come from Ag clusters while from the surrounding coordinated Ag{sup +} ions or Ag{sup 0} atoms. It was disclosed that the characteristic yellow-green emission at ∼560 ± 15 nm is strongly associated with the coordinating water molecules to the Ag{sup +} ions or Ag{sup 0} atoms, which is clear evidence for that the efficient emission from Ag activated zeolites may not originate from the quantum confinement effect.

  16. Solvothermal synthesis of nickel-tungsten sulfides for 2-propanol dehydration.

    PubMed

    Gómez-Gutiérrez, Claudia M; Luque, P A; Guerra-Rivas, G; López-Sánchez, J A; Armenta, M A; Quintana, J M; Olivas, A

    2015-01-01

    The bimetallic nickel-tungsten catalysts were prepared via solvothermal method. The X-ray Diffractometer (XRD) analysis revealed that the corresponding peaks at 14°, 34°, and 58° were for tungsten disulfide (WS2 ) hexagonal phase. The catalysts displayed different crystalline phase with nickel addition, and as an effect the WS2 surface area decreased from 74.7 to 2.0 m(2) g(--1) . In this sense, high-resolution transmission electron microscopy (HRTEM) showed the layers set in direction (002) with an onion-like morphology, and in the center of the particles there is a large amount of nickel contained with 6-8 layers covering it. The catalytic dehydration of 2-propanol was selective to propene in 100% at 250 °C for the sample with 0.7 of atomic ratio of Ni/Ni + W. PMID:25676058

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

    SciTech Connect

    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.

  18. Dehydration and crystallization of amorphous calcium carbonate in solution and in air

    PubMed Central

    Ihli, Johannes; Wong, Wai Ching; Noel, Elizabeth H.; Kim, Yi-Yeoun; Kulak, Alexander N.; Christenson, Hugo K.; Duer, Melinda J.; Meldrum, Fiona C.

    2014-01-01

    The mechanisms by which amorphous intermediates transform into crystalline materials are poorly understood. Currently, attracting enormous interest is the crystallization of amorphous calcium carbonate, a key intermediary in synthetic, biological and environmental systems. Here we attempt to unify many contrasting and apparently contradictory studies by investigating this process in detail. We show that amorphous calcium carbonate can dehydrate before crystallizing, both in solution and in air, while thermal analyses and solid-state nuclear magnetic resonance measurements reveal that its water is present in distinct environments. Loss of the final water fraction—comprising less than 15% of the total—then triggers crystallization. The high activation energy of this step suggests that it occurs by partial dissolution/recrystallization, mediated by surface water, and the majority of the particle then crystallizes by a solid-state transformation. Such mechanisms are likely to be widespread in solid-state reactions and their characterization will facilitate greater control over these processes. PMID:24469266

  19. The role of oropharnygeal receptors in thirst perception after dehydration and rehydration.

    PubMed

    Obika, L F O; Okpere, S O; Ozoene, J O; Amabebe, E

    2014-01-01

    This study examined the effect of drinking and gargling on thirst perception (TP) in 33 young dehydrated female subjects (18-25 yrs), using the visual analogue scale (VAS). Group A subjects drank, while group B gargled the fluid provided - 0.0%, 0.9% and 1.8% NaCl (7.0 ml/kg body weight of fluid). The procedure was alternated two weeks later. All subjects dehydrated for 18 hours prior to the study, and the last 12-hour urine was collected and volume recorded. Subject who provided a 12 hr urine volume greater than 400 ml was excluded from the study. After recording the baseline TP, and voiding the bladder, drinking/gargling was done within 5 minutes, and the subsequent TPs were recorded at 5 minutes interval for 25 minutes. Blood samples were collected before and at the end of the 30 minutes, when urine volumes were recorded. Drinking (0.0% and 1.8% NaCl) resulted in an initial decrease in thirst perception, which was statistically significant (p<0.05) only up to 10 minutes. Water intake ad libitum (mean ± SEM) at the end of the 30 minutes was statistically significantly lower (p<0.05) only in the group that drank 0.0% NaCl. Gargling on the other hand did not affect TP and water intake throughout the period of study. It can be concluded that drinking, but not gargling reduces thirst perception irrespective of the tonicity of the fluid as earlier reported (Obika et. al., 2009; Salata et. al., 1987). This study suggests that the oropharyngeal receptors for TP are activated by recurrent stimulation by the act of drinking rather than gargling. PMID:26196564

  20. Dehydration in the tropical tropopause layer: A case study for model evaluation using aircraft observations

    NASA Astrophysics Data System (ADS)

    Ueyama, Rei; Jensen, Eric J.; Pfister, Leonhard; Diskin, Glenn S.; Bui, T. P.; Dean-Day, Jonathan M.

    2014-05-01

    The dynamical and microphysical processes that influence water vapor concentrations in the tropical tropopause layer (TTL) are investigated in simulations of ice clouds along backward trajectories of air parcels sampled during three flights of the Airborne Tropical Tropopause Experiment over the central to eastern tropical Pacific in boreal fall 2011. ERA-Interim reanalysis temperatures interpolated onto the flight tracks have a negligible (-0.09 K) cold bias compared to aircraft measurements of tropical cold point temperature thus permitting case study simulations of TTL dehydration. When the effects of subgrid-scale waves, cloud microphysical processes, and convection are considered, the simulated water vapor mixing ratios on the final day of 40 day backward trajectories exhibit a mean profile that is within 20-30% of the mean of the aircraft measurements collected during vertical profiling maneuvers between the 350 and 410 K potential temperature levels. Averaged over the three flights, temperature variability driven by subgrid-scale waves dehydrated the 360-390 K layer by approximately -0.5 ppmv, whereas including homogeneous freezing of aqueous aerosols and subsequent sublimation and rehydration of ice crystals increased water vapor below the 380 K level by about +1 ppmv. The predominant impact of convection was to moisten the TTL, resulting in an average enhancement below the 370 K level by +1 to 5 ppmv. Accurate (to within 0.5-1 ppmv) predictions of TTL water vapor using trajectory models require proper representations of waves, in situ ice cloud formation, and convective influence, which together determine the saturation history of air parcels.