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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. 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 ...

  7. 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 ...

  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 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.

  9. 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...

  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. 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...

  4. 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...

  5. 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

  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. 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.

  11. 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

  12. 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.

  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. 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

  20. 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.

  1. 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

  2. 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.

  3. 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.

  4. 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

  5. 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

  6. 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.

  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. 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)

  9. 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.

  10. 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...

  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. 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

  20. 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.

  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. 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.

  4. 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

  5. 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

  6. 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

  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. 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

  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. 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

  17. 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

  18. 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.

  19. 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.

  20. 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.

  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. 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.

  3. 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.

  4. 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

  5. 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

  6. 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

  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. 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

  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. 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...

  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 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...

  17. 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...

  18. 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...

  19. 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...

  20. 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...

  1. 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...

  2. 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...

  3. 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...

  4. 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...

  5. 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...

  6. 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...

  7. 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...

  8. 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...

  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. 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

  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. 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.

  13. 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.

  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 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

  16. 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

  17. 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

  18. 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.

  19. 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

  20. 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

  1. 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.

  2. 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.

  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. 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.

  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. 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

  8. 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

  9. 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

  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. 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

  13. 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

  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. 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

  2. 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

  3. 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.

  4. 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

  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. 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

  16. 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.

  17. 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.

  18. 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.

  19. 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

  20. 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

  1. 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.

  2. 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

  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. 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

  12. 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

  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. 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

  15. 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.

  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. 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

  19. 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

  20. 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

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. 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

  6. 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

  7. 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

  8. 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

  9. 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.

  10. 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

  11. 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

  12. 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.

  13. 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...

  14. 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 ...

  15. 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...

  16. 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.

  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 (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.

  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 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.

  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.; 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.

  20. 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

  1. 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...

  2. 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...

  3. 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...

  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. 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

  7. 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

  8. 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

  9. 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

  10. 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.

  11. 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

  12. 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.

  13. 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

  14. 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

  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. 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

  6. 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

  7. 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

  8. 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

  9. 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.

  10. 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