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Sample records for kalahari transect wet

  1. Vegetation and Soil Responses to Fertilization Along the Kalahari Transect

    Science.gov (United States)

    Wang, L.; Caylor, K.; D'Odorico, P.; Ries, L.; Okin, G.; Swap, R.; Shugart, H.; Scanlon, T.; Macko, S.

    2006-12-01

    To better understand how soil nutrients and soil moisture interactively control vegetation dynamics in savanna ecosystems, a large-scale stable isotope fertilization experiment was conducted using four study sites with different mean annual precipitation (MAP), along the Kalahari Transect (KT). KT in southern Africa traverses a dramatic aridity gradient (from 200 mm to more than 1000 mm MAP, through the Republic of South Africa, Botswana, Namibia and Zambia), on relatively homogenous soils (deep Kalahari sands). The experimental design consisted of a randomized block design with four 21 m x 13 m plots at each site. Each plot was divided into four 10 m x 6 m subplots with a 1 m buffer zone between each subplot. Four treatments (N addition, P addition, N+P addition and control) were randomly applied to the subplots. The N and N+P additions were enriched with 15N to a signature of 10.3 ‰. Grass foliar 15N was significantly higher in the N and N+P addition than in the control or P-addition during following growing season. The differences disappeared in the second growing season. Soil 15N and soil surface CO2 fluxes were not different between treatments in both seasons for all four locations. Herbaceous biomass responses to fertilization were different in different locations. Significantly higher biomass was observed in N+P addition in driest site and in P addition in wetter site. The 15N results provide evidence of N uptake limitation and we also see evidence of productivity limitation. These results suggest that there is a complex feedback between soil and vegetation in savanna ecosystems.

  2. Nitrogen Limitation Along The Kalahari Transect: Preliminary Results From A Stable Isotope Fertilization Experiment

    Science.gov (United States)

    Wang, L.; Macko, S.; D'Odorico, P.; Ries, L.

    2005-12-01

    Globally, savannas cover ~ 20% of the Earth's land area. Nutrients and soil moisture interactively control vegetation dynamics in many savannas although it is unclear how the relative importance of water and nutrient limitations (especially nitrogen) change with the mean climatic conditions. The Kalahari Transect (KT) in southern Africa traverses a dramatic aridity gradient (from ~ 200 mm to more than 1000 mm of mean annual precipitation (MAP), through the Republic of South Africa, Botswana, Namibia and Zambia), on relatively homogenous soils (deep Kalahari sands). This transect offers the ideal setting to study nutrient and vegetation dynamics without confounding soil effects. To improve the understanding of nitrogen and water controls on savanna vegetation, this study tested the hypothesis that the savannas in the Kalahari switch from conditions of water limitation in the dry areas to nutrient limitation in the wet areas. To this end, we conducted a large-scale stable isotope fertilization experiment using four study sites with different MAP. The transect included sites in Mongu, Zambia (MAP ~950mm), Pandamatenga, Ghanzi, and Tshane, Botswana with MAP ranging between 700 mm and 300 mm. The experimental design consisted of a randomized block design with four 21 m x 13 m plots at each site. Each plot was divided into four 10 m x 6 m subplots with 1 m buffer zone between each subplot. Four treatments (N addition, P addition, N+P addition and control) were randomly applied to the subplots. The experiment began during the dry season, in August, 2004, when 39g/m2 of Ca(NO3)2 (3.3g-N/ m2 ) was evenly applied to the N and N+P subplots, and 7.5g/m2 of Ca(H2PO4)2 (1.7g-P/m2) was applied to the P and N+P subplots, while the control subplots were left with no treatment. The N and N+P additions were enriched with 15N (Ca(15NO3)2 ) to a signature of 10.3 ‰. Before application, soil samples from two different layers (0cm and 50cm) outside the plots and foliar samples of the

  3. Assessing Fractional Tree, Grass, and Bare Soil Cover from NDVI and Rainfall Time Series along the Kalahari Transect, Africa

    Science.gov (United States)

    Scanlon, T. M.; Albertson, J. D.; Caylor, K. K.; Williams, C. A.

    2001-12-01

    Savanna ecosystems are water-limited, a characteristic that can be exploited to estimate fractional cover of trees, grass, and bare soil over large-scale areas from synthesis of remote sensing and rainfall measurements. A method is presented to estimate fractional cover components along the Kalahari Transect (KT), an aridity gradient in southern Africa, based upon the differing ways in which grasses and trees respond to rainfall. Mean wet season normalized difference vegetation index (NDVI) and the sensitivity of the NDVI to variation in wet season rainfall are used as input into a linear unmixing model, and end-members for this analysis are extracted on the basis of best fit to the observed data. The end-members for the mixing analysis are consistent with the qualitative characteristics of trees (high NDVI, low sensitivity of NDVI to interannual variations in rainfall), bare soil (low NDVI, low sensitivity), and the transient grass/ bare soil area (moderate NDVI, high sensitivity). Sensitivity of NDVI to rainfall was based upon the relationship between NDVI and the standardized anomalies, or z-score, of the wet season precipitation, resulting in a 22% improvement in the number of significant relationships (parea is limited by the tree fractional cover on the wetter end of the transect, peaks at approximately 450 mm of mean wet season rainfall, and is limited by rainfall on the more arid portion of the transect. With NDVI for grass inferred from the data, predictions of yearly tree, grass, and bare soil fractional cover can be derived. No calibration or training sets were required for this unmixing procedure, and an additional advantage of this method over traditional unmixing approaches is that cover components can be predicted for future rainfall scenarios. This remote sensing-based model framework, together with a tree/grass interaction submodel, could be used to predict long-term migration of the cover components along this gradient in response to climate

  4. Evaluating the use of the belt transect method in determining native plant composition changes in upland and wet meadow habitats on Lacreek National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Determine if the belt transect method can be used to detect a 10% increase in native plant composition on upland and wet meadow habitats on Lacreek NWR within a 10...

  5. Notes on some Edible wild plants found in the Kalahari

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    M.E. Keith

    1975-07-01

    Full Text Available Limited work done on edible, indigenous plants to date, mainly concerns seasonal species. To develop a more reliable guide on food-plant sources for survival conditions in the field, a study directed at a survey of non-seasonal plants is conducted in the Kalahari. Descriptions of six edible non-seasonal plants for the Kalahari are given.

  6. The Herpetology of the Southern Kalahari domain

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    W. D Haacke

    1984-12-01

    Full Text Available The herpetofauna of the southern Kalahari has mixed affinities, as this area lies on a rainfall gradient in a critical area where a transition between the arid south-west and the moister north-east takes place. As the variation in substrate type is relatively limited, the effect of the rainfall gradient appears to influence and determine the range limits of many taxa in both directions, resulting in an area in which of 55 recorded reptiles, 11 western taxa overlap or form a parapatric zone with 25 eastern taxa, while the remaining taxa are endemic or wideranging.

  7. Springbok behaviour as affected by environmental conditions in the Kalahari

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    Hein Stapelberg

    2008-05-01

    Full Text Available Springbok behavioural ecology in the Kalahari was examined with the use of public questionnaires and field forms. Springbok favoured grass and forbs overall more than shrubs and trees, but diet selection was influenced by time of day and season. Feeding was the most common activity and the frequency of occurrence varied during the day and between seasons. Weather and microhabitat conditions were found to have a significant effect on the feeding behaviour. Springbok fed in direct sunlight in the mornings and moved into the shade during the afternoon. More time was spent feeding in the shade during the warmer months than during the colder months, especially under northerly to northeasterly wind directions. Natural licks were commonly utilised. Herd sizes were found to increase during the cold-dry season and decrease during the hot-wet season. Springbok and blue wildebeest appeared to avoid competition by niche separation. The study showed that springbok behaviour was significantly affected by environmental conditions. These results imply that changes in climatic conditions, such as those predicted by climate change, or changes in vegetation structure due to degradation, can negatively affect springbok behaviour.

  8. Food ecology of the Kalahari Lion Panthera leo

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    F. C Eloff

    1984-12-01

    Full Text Available Aspects of the food ecology of the lion were researched in the Kalahari Gemsbok National Park. A survey based on 195 periods of 24 hours each, indicated that porcupines represented 32,3 and gemsbok 25 of lion kills. Because so many small or young mammals are being caught, a single Kalahari lion probably makes as many as 50 kills per year @ considerably more than anywhere else in Africa. The Kalahari lion covers a distance, on average, of 11,8 km per night in search of food. The hunting success of the Kalahari lion, the ecological division of predators, and the effect of food on mortality is discussed. Predation by lions seems to play an insignificant role in the regulation of prey population numbers.

  9. Multivariate analysis of the hunting tactics of Kalahari leopards

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    J. du P. Bothma

    1997-01-01

    Full Text Available The hunting tactics of male and female leopards in the southern Kalahari were analysed for prey-specific patterns. The field study was based on tracking leopard spoor in the sandy substrate of the Kalahari. Visual profiles for each type of prey were compiled for various facets of hunting. Data sets were analysed further, using Correspondence Analysis and Detrended Correspondence Analysis. The results indicate that multivariate analysis can be used to demonstrate prey-specific hunting tactics in Kalahari leopards. In using a scarce prey base, Kalahari leopards seem to be number maximisers as they are unselective of prey type, age or sex. The presence of prey-specific hunting tactics may indicate a move along a continuum towards some degree of energy maximisation.

  10. Lithostratigraphy of the Kalahari Group in northeastern Namibia

    Science.gov (United States)

    Wanke, Heike; Wanke, Ansgar

    2007-08-01

    The Kalahari Group in northeastern Namibia consists of terrestrial sediments deposited in a tectonically active basin that was formed by flexural uplift of the African continental margin and independent structures related to rifting. The thickness of the sequence varies from a few meters to around 400 m. Greatest thicknesses occur where the NW-SE trending Kalahari basin axis conjugates with NE-SW trending grabens. Repeated phases of flooding and desiccation dominate the depositional environments of the Kalahari Group in northeastern Namibia. Associations of lithofacies allow recognition of distinct depositional settings such as proximal debris flows, braided streams and sand fans, and pans and sandflats. The northeastern Namibian Kalahari Group rests unconformable on the pre-Kalahari surface which showed a relatively pronounced relief in the Epukiro area. The succession starts with conglomerates, breccias and pebbly sandstones, followed by carbonates, sandstones of various maturities, and silcretes. Ferruginous sandstones and ferricretes occur locally. The onset of Kalahari Group deposition was likely a basin-wide event and therefore the basal lithostratigraphic units can be correlated with confidence. Conversely, the correlation of the succeeding lithostratigraphic units remains fairly speculative.

  11. The response of ungulates to rainfall along the riverbeds of the Southern Kalahari

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    M. G. L Mills

    1984-12-01

    Full Text Available The responses of springbok Antidorcas marsupialis, gemsbok Oryx gazella, blue wildebeest Connochaetes taurinus and red hartebeest Alcelaphus buselaphus to rainfall along the riverbeds of the southern Kalahari are analysed. Springbok reacted most rapidly to rainfall along the riverbeds and, by browsing in dry times, maintained a fairly stable presence throughout the year, although the actual number present in any one year was dependent on annual rainfall. Gemsbok responded more slowly to rainfall and reached their highest numbers in years of high rainfall when the grasses were tall and mature, after which they rapidly departed from the riverbeds. Red hartebeest also reached their highest numbers during the rainy season, but departed slightly more slowly than gemsbok. In dry years, they too, failed to come into the riverbeds. Blue wildebeest in the vicinity of the riverbeds tended to be more sedentary than the other species. The presence of potable artificial water appeared to be more important for wildebeest than for the other species and, although rainfall was undoubtedly an important factor in regulating their numbers along the riverbeds, they depended to a greater extent on breeding success and mortality factors, than on emigration and immigration. The overall seasonal pattern of ungulate abundance along the riverbeds in the southern Kalahari was one of wet season concentrations and dry season dispersion.

  12. Water use by the Kalahari Lion Panthera Leo Vernayi

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    F.C. Eloff

    1973-07-01

    Full Text Available The extent to which the Kalahari lion can survive without having to drink water was investigated in the Kalahari Gemsbok National Park. It was found that while they may drink regularly where water is available, they may become completely independent of water under extreme desert conditions. Sufficient moisture for their needs seems to be obtained from the blood and body fluids of their prey and the vegetable components of theirdiet. Loss of water through evaporation is reduced by the lion'sleisurely way of life.

  13. The soils of the Kalahari Gemsbok National Park

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    Theo H Van Rooyen

    1984-12-01

    Full Text Available Field observations made during a reconnaissance soil survey of the Kalahari Gemsbok National Park showed that a variety of soils occur within the broad group of so-called Kalahari sands. For discussion purposes, the soils were classified into five main groups of which the red and yellow sands took precedence over the other soils because of their geographical distribution and pedological significance. The soils are discussed with special reference to their classification, site and parent material, their morphological, chemical and mineralogical properties and drainage characteristics. Attention was also given to the relationship between the soils and landforms, and a brief note on the inherent fertility status of the soils has been included.

  14. Symposium on the Kalahari Ecosystem summary and conclusions

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    A. J Hall-Martin

    1984-12-01

    Full Text Available This symposium has dealt largely with the Kalahari Gemsbok National Park (KGNP, an area which has been under the control of the National Parks Board of Trustees since 1931. The park, which covers some 9 600 km2 is part of an international conservation area which includes the adjoining 26 600 km2 Gemsbok National Park in Botswana and adjoining wildlife management areas.

  15. The geology of the Kalahari Gemsbok National Park

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    S. J Malherbe

    1984-12-01

    Full Text Available The floor rocks of the Kalahari Group are only known from boreholes. It consists of rocks of the Karoo Sequence with its associated intrusions of dolerite. The pre-Kalahari topography was dissected by rivers which drained in the direction of the present Botswana. The distribution of the oldest formation of the Kalahari Group, the Wessels Formation (clayey gravel, and the overlying Budin Formation (clay was also determined from borehole records. The Karoo Sequence was probably the source of these rocks. The overlying Eden Formation (sandstone, grit and conglomerate had a source which could yield much sand. All these formations were deposited under fluviatile conditions. The Mokalanen Formation (calcrete and the Gordonia Formation (sand indicate a change from a humid to an arid environment. The Lonely Formation (clayey diatomaceous limestone was deposited in a lacustrine environment. It also indicates a higher rainfall in an otherwise arid period. The Goeboe Goeboe Formation consists of clay and sand in the pans and rivers.

  16. Evaluating ecohydrological theories of woody root distribution in the Kalahari.

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    Abinash Bhattachan

    Full Text Available The contribution of savannas to global carbon storage is poorly understood, in part due to lack of knowledge of the amount of belowground biomass. In these ecosystems, the coexistence of woody and herbaceous life forms is often explained on the basis of belowground interactions among roots. However, the distribution of root biomass in savannas has seldom been investigated, and the dependence of root biomass on rainfall regime remains unclear, particularly for woody plants. Here we investigate patterns of belowground woody biomass along a rainfall gradient in the Kalahari of southern Africa, a region with consistent sandy soils. We test the hypotheses that (1 the root depth increases with mean annual precipitation (root optimality and plant hydrotropism hypothesis, and (2 the root-to-shoot ratio increases with decreasing mean annual rainfall (functional equilibrium hypothesis. Both hypotheses have been previously assessed for herbaceous vegetation using global root data sets. Our data do not support these hypotheses for the case of woody plants in savannas. We find that in the Kalahari, the root profiles of woody plants do not become deeper with increasing mean annual precipitation, whereas the root-to-shoot ratios decrease along a gradient of increasing aridity.

  17. A habitat map of the Kalahari Gemsbok National Park

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    J. Du P. Bothma

    1973-07-01

    Full Text Available The Kalahari Gemsbok National Park exhibits some six major habitats. Away from the river beds the tree savanna is limited to the northern corner of the park, consisting of Acacia girajfae woodland and scattered dunes. The Nossob and Auobriverbeds and adjacent areas also harbour A. girqffae except in the south where A. haematoxylon becomes dominant, and where the Karoo flora increases. The dunes covered with trees and shrubs usually support Boscia albitrunca, A. mellifera and an occasional A. girqffae. Where the dunes are superficially without shrub vegetation, Stipagrostis amabilis is dominant, although low, shrub-like A. haematoxylon also occurs. The plains also contain low A. haematoxylon shrub and several dominant grasses. Pans are abundantand their vegetation is usually characterized by stands of Rhigozum trichotomum and Monechma incanum.

  18. Avian adaptations to the Kalahari environment: A typical continental semidesert

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    G. L Maclean

    1984-12-01

    Full Text Available Bird species adapted to the Kalahari are generally either (a sedentary, insectivorous (or carnivorous and non-gregarious, or (b nomadic, granivorous and gregarious even when breeding. Ground-dwelling birds predominate numerically and are cryptically coloured to avoid predation. Many species have nasal glands which secrete hypertonic solutions in response to the intake of fluids with high solute concentrations, as an adaptation to water conservation. Thermoregulation is discussed especially in relation to high ambient temperatures. Breeding is initiated in most species by rainfall or associated ecological effects, correlated with improved body condition of the females; lag periods between rain and egglaying are related to diet and time of year. Nest orientation is also related to season and capitalizes on maximal shade in summer. Parental care in sandgrouse is discussed.

  19. Lake Transect : 1986

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document summarizes transect surveys that were done at four different lakes on St. Vincent National Wildlife Refuge in 1986. Lists of the plant species found at...

  20. Lake Transect : 1988

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document summarizes transect surveys that were done at four different lakes on St. Vincent National Wildlife Refuge in 1988. Lists of the plant species found at...

  1. Lake Transect : 1989

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document summarizes transect surveys that were done at four different lakes on St. Vincent National Wildlife Refuge in 1989. Lists of the plant species found...

  2. A Check List of Flowering Plants of the Kalahari Gemsbok National Park

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    N. Van Rooyen

    1988-10-01

    Full Text Available A check list containing 397 plant species has been compiled for the Kalahari Gemsbok National Park which occupies an area of approximately 9 600 km2. These species represent 191 genera and 51 families. The Monocotyledonae are represented by 98 species (24,7 of the total number of species and the Dicotyledonae by 299 species (75,3 of the total number of species. According to the life form spectrum the Kalahari Gemsbok National Park is a therophyte-hemicryptophyte area.

  3. Comments on transect methodology

    Energy Technology Data Exchange (ETDEWEB)

    Eberhardt, L.L.

    1980-02-01

    One of the outcomes of the recent spate of attention to environmental problems is the realization that we do not have suitable methods to census non-game species. Since marking is expensive and time-consuming, investigators have tended to look for methods that involve only visual techniques. One of the leading candidates thus becomes the line transect method. The purpose here is to briefly describe some of the available transect methods, and to comment on some aspects that may be of particular interest and importance.

  4. The traveling transect

    DEFF Research Database (Denmark)

    Braae, Ellen Marie; Diedrich, Lisa; Lee, Gini

    2013-01-01

    conditions, correspond to the fields of natural sciences and to spatial aesthetics. The Travelling Transect method, inspired by Alexander von Humboldt’s method of transareal travelling and transversal collecting of ephemeral information from site, informs our exploratory fieldwork in the water landscapes...

  5. Traumatic transection of aorta.

    Science.gov (United States)

    Ho, C K; Yip, K T; Eng, J B; Rajan, L; Tan, B H

    2001-09-01

    A 16 year-old man presented with fracture of both his femurs after a road traffic accident. Chest radiograph revealed mediastinal widening. Subsequent CT scan and arch aortogram confirmed the findings of traumatic aortic arch transection at the isthmus. He underwent successful surgical repair. High index of suspicion and prompt actions are important in managing this potentially fatal but treatable condition.

  6. Nitrogen cycling in the soil-plant system along a precipitation gradient in the Kalahari sands

    CSIR Research Space (South Africa)

    Aranibar, JN

    2004-03-01

    Full Text Available NO emissions increased with temperature and moisture and were therefore estimated to be lower in drier areas. The isotopic pattern observed in the Kalahari (N-15 enrichment with aridity) agrees with the lower soil organic matter, soil C/N, and N-2 fixation...

  7. A revised check-list of birds in the Kalahari Gemsbok National Park

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    M. G. L. Mills

    1976-08-01

    Full Text Available A more complete list of the birds in the Kalahari Gemsbok National Park is given, including the results of three and a half years of observations. A total of 214 species have now been identified for the Park, among which 75 are resident throughout the year, 37 are migrants, 14 are nomads and 88 are vagrants.

  8. South African Acari. V. Some mites of the Kalahari Gemsbok National Park

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    Magdalena K.P. Smith Meyer

    1989-10-01

    Full Text Available A check list of phytophagous and predaceous mites collected from the Kalahari Gemsbok National Park is given. Data on the habitat and distribution of the 12 known species are presented. The following 10 species are described for the first time: Typhlodromus eremicus, Bryobia orycustodia, B. birivularis, B. deserticola, Aplonobia plinthi, Neopetrobia burchelliae, N. convolvuli, N. lerichei, Aegyptobia odontipilis and Abrolophus spiculosus.

  9. Spirituality, shifting identities and social change: Cases from the Kalahari landscape

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    Mary E. Lange

    2015-03-01

    Full Text Available Storytelling, art and craft can be considered aesthetic expressions of identities. Kalahari identities are not fixed, but fluid. Research with present-day Kalahari People regarding their artistic expression and places where it has been, and is still, practised highlights that these expressions are informed by spirituality. This article explores this idea via two Kalahari case studies: Water Stories recorded in the Upington, Kakamas area, as well as research on a specific rock engraving site at Biesje Poort near Kakamas. The importance of the Kalahari People’s spiritual beliefs as reflected in these case studies and its significance regarding their identities and influence on social change and/or community development projects is discussed. The article thus highlights ways in which spirituality can be considered in relation to social change projects that are characterised by partnerships between local community, non-government and tertiary education representatives and researchers and that highlight storytelling as an integral part of people’s spirituality.

  10. Some population characteristics of the Lion Panthera Leo in the Kalahari Gemsbok National Park

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    M.G.L. Mills

    1978-09-01

    Full Text Available Two methods of estimating the number of lions in the Kalahari Gemsbok National Park, Republic of South Africa, are described; the first gives a minimum figure (113 and the second a more realistic one (140. Data are presented on sex and age ratios and pride composition. The factors contributing to the low density are briefly discussed and some management practices in connection with lions trespassing out of the Park are suggested.

  11. Anticipating Vulnerability to Climate Change in Dryland Pastoral Systems: Using Dynamic Systems Models for the Kalahari

    OpenAIRE

    Dougill, AJ; Fraser, EDG; Reed, MS

    2010-01-01

    It is vitally important to identify agroecosystems that may cease functioning because of changing climate or land degradation. However, identifying such systems is confounded on both conceptual and methodological grounds, especially in systems that are moving toward thresholds, a common trait of dryland environments. This study explores these challenges by analyzing how a range of external pressures affect the vulnerability of dryland pastoral systems in the Kalahari. This is achieved by empl...

  12. The rodents and other small mammals of the Kalahari Gemsbok National Park

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    J. A. J Nel

    1984-12-01

    Full Text Available The state of knowledge pertaining to the biology of small mammals occurring in the Kalahari Gemsbok National Park is reviewed with reference to completed and ongoing projects. Aspects of daily activity rhythms, habitat selection, diet, population fluctuations and changes in community structure, as well as reproduction are discussed. The zoogeography of the park is alluded to, and aspects which need ad- ditional attention are mentioned.

  13. Sm-Nd and Rb-Sr Isotopic Studies of Meteorite Kalahari 009: An Old VLT Mare Basalt

    Science.gov (United States)

    Shih, C.-Y.; Nyquist, L. E.; Reese, Y.; Bischoff, A.

    2008-01-01

    Lunar meteorite Kalahari 009 is a fragmental basaltic breccia contain ing various very-low-Ti (VLT) mare basalt clasts embedded in a fine-g rained matrix of similar composition. This meteorite and lunar meteorite Kalahari 008, an anorthositic breccia, were suggested to be paired mainly due to the presence of similar fayalitic olivines in fragment s found in both meteorites. Thus, Kalahari 009 probably represents a VLT basalt that came from a locality near a mare-highland boundary r egion of the Moon, as compared to the typical VLT mare basalt samples collected at Mare Crisium during the Luna-24 mission. The concordant Sm-Nd and Ar-Ar ages of such a VLT basalt (24170) suggest that the extrusion of VLT basalts at Mare Crisium occurred 3.30 +/- 0.05 Ga ag o. Previous age results for Kalahari 009 range from approximately 4.2 Ga by its Lu-Hf isochron age to 1.70?0.04 Ga of its Ar-Ar plateau ag e. However, recent in-situ U-Pb dating of phosphates in Kalahari 009 defined an old crystallization age of 4.35+/- 0.15 Ga. The authors su ggested that Kalahari 009 represents a cryptomaria basalt. In this r eport, we present Sm-Nd and Rb-Sr isotopic results for Kalahari 009, discuss the relationship of its age and isotopic characteristics to t hose of other L-24 VLT mare basalts and other probable cryptomaria ba salts represented by Apollo 14 aluminous mare basalts, and discuss it s petrogenesis.

  14. The traveling transect

    DEFF Research Database (Denmark)

    Braae, Ellen Marie; Diedrich, Lisa; Lee, Gini

    2013-01-01

    , when working with the more unpredictable qualities of sites as in water-made landscapes, designers often lack mapping and representational tools capable of capturing and expressing ephemeral qualities - dynamics, relationships and atmospheres. These abstract qualities, that exist over physical site...... in everyday practice, the Canarysect project negotiates testing and capture of the dynamic, relational and atmospheric qualities encountered along lines of transect across island lands and waters. Individual sketching, photography and modelling gestures merge into a common archipelago of thinking around...... the water landscapes of the Canaries. Through the medium of the Nordes 2013 exhibition, coexisting tableaux of imagery and form produce another mapping of already-known island landscapes, brought to contemporary presence through a gaze informed by the layered histories of the landscapes and peoples, sites...

  15. Anticipating Vulnerability to Climate Change in Dryland Pastoral Systems: Using Dynamic Systems Models for the Kalahari

    Directory of Open Access Journals (Sweden)

    Andrew J. Dougill

    2010-06-01

    Full Text Available It is vitally important to identify agroecosystems that may cease functioning because of changing climate or land degradation. However, identifying such systems is confounded on both conceptual and methodological grounds, especially in systems that are moving toward thresholds, a common trait of dryland environments. This study explores these challenges by analyzing how a range of external pressures affect the vulnerability of dryland pastoral systems in the Kalahari. This is achieved by employing dynamic systems modeling approaches to understand the pathways by which communities became vulnerable to drought. Specifically, we evaluate how external pressures have changed: (1 different agroecosystems' abilities to tolerate drought, i.e., ecosystem resilience; (2 rural communities' abilities to adapt to drought, mediated via their access to assets; and (3 the ability of institutions and policy interventions to play a role in mediating drought-related crises, i.e., socio-political governance. This is done by reanalyzing ecological and participatory research findings along with farm-scale livestock offtake data from across the Kalahari in Botswana. An iterative process was followed to establish narratives exploring how external drivers led to changes in agroecosystem resilience, access to assets, and the institutional capacity to buffer the system. We use "causal loop diagrams" and statistical dynamic system models to express key quantitative relationships and establish future scenarios to help define where uncertainties lie by showing where the system is most sensitive to change. We highlight how that greater sharing of land management knowledge and practices between private and communal land managers can provide 'win-win-win' benefits of reducing system vulnerability, increasing economic income, and building social capital. We use future scenario analyses to identify key areas for future studies of climate change adaptation across the Kalahari.

  16. Spatial and temporal distribution of cyanobacterial soil crusts in the Kalahari: Implications for soil surface properties

    Science.gov (United States)

    Thomas, A. D.; Dougill, A. J.

    2007-03-01

    Localised patterns of erosion and deposition in vegetated semi-arid rangelands have been shown to influence ecological change and biogeochemical cycles. In the flat, vegetated Kalahari rangelands of Southern Africa the factors regulating erodibility of the fine sand soils and the erosivity of wind regimes require further investigation. This paper reports on the spatial and temporal patterns of cyanobacterial soil crust cover from ten sites at five sampling locations in the semi-arid Kalahari and discusses the likely impact on factors regulating surface erodibility and erosivity. Cyanobacterial soil crust cover on Kalahari Sand varied between 11% and 95% of the ground surface and was higher than previously reported. Cover was inversely related to grazing with the lowest crust cover found close to boreholes and the highest in the Game Reserve and Wildlife Management Zone. In grazed areas, crusts form under the protective canopies of the thorny shrub Acacia mellifera. Fenced plot data showed that crusts recover quickly from disturbance, with a near complete surface crust cover forming within 15 months of disturbance. Crust development is restricted by burial by wind blown sediment and by raindrop impact. Crusts had significantly greater organic matter and total nitrogen compared to unconsolidated surfaces. Crusts also significantly increased the compressive strength of the surface (and thus decreased erodibility) and changed the surface roughness. Establishing exactly how these changes affect aeolian erosion requires further process-based studies. The proportion of shear velocity acting on the surface in this complex mixed bush-grass-crust environment will be the key to understanding how crusts affect erodibility.

  17. Provenance of the Quaternary Southern Kalahari sediments: A wetland that became dry

    Science.gov (United States)

    Vainer, Shlomy; Erel, Yigal; Matmon, Ari

    2017-04-01

    The ca. 140 Ma vast Kalahari basin is characterized by uplifted margins, terrestrial sedimentation within semi endorheic sub-basins, subdued morphology and tectonic quiescence. This intracratonic basin has been subjected to a prolonged period of subsidence affecting its sedimentary fill by changing plate motion and climatic cycles. Provenance studies of Kalahari Group sediments mainly focused on the easily accessible uppermost part that represents only the last phase of sedimentation, leaving unresolved questions for the rest of the strata. The Southern Kalahari Group succession exposed along the walls of the Mamatwan Mine, Northern Cape, South Africa, reveals three main depositional environments; a bottom pluvial, low-energy water body, a middle fluvial, high-energy environment and an upper aeolian sandy unit. The entire section, which was deposited within the Quaternary, records significant environmental and depositional changes suggesting a highly dynamic landscape. The fully exposed section (55 m) of the Kalahari Group at Mamatwan Mine was analysed for its mineralogy, elemental composition, Sr, Nd and Pb isotopic ratios and iron species. Mineralogical assemblage imply that a saline and alkaline shallow water-body existed during the early-middle Pleistocene contemporaneous with relative dense hominine occupation of the area. Isotopic ratios were used to determine the source of the sediments, which was found to be mainly of mafic rocks located to the north-east of Mamatwan. Weathering sensitive indices of both elemental ratios and iron phases show that sediments carried to the basin underwent considerable weathering indicative to a greater availability of surface water than the present. The lacustrine environment was rapidly filled with clasts that were derived mainly from the surrounding hills and experienced limited degree of chemical weathering during transport, but underwent subsequent groundwater alteration by iron-rich solution and precipitation of celcrete

  18. The diet of the brown hyaena hyaena brunnea in the Southern Kalahari

    Directory of Open Access Journals (Sweden)

    M.G.L. Mills

    1978-09-01

    Full Text Available Four methods for studying the diet of the brown hyaena are discussed. A combination of direct observations (of individuals Fitted with radio collars and beta lights and faecal analysis yielded the best information. Analysis of food items found at dens was also useful, but tracking spoor had severe limitations. The brown hyaena in the southern Kalahari is predominantly a scavenger of all kinds of vertebrate remains, supplementing its diet with insects, wild fruits, birds' eggs and the occasional small animal which it kills. It is thus well adapted to the harsh conditions of this arid region where large ungulates are thinly distributed.

  19. New records of flowering plants and ferns from the Kalahari Gemsbok National Park

    Directory of Open Access Journals (Sweden)

    N. Van Rooyen

    1997-02-01

    Full Text Available A supplementary list of 101 new records of plant species, as well as an updated alphabetical check list comprising a total of 489 plant species, were compiled for the Kalahari Gemsbok National Park. The area covers approximately 9 593 km2. These species rep- resent 214 genera and 55 families. The Pteridophyta is represented by two species (0.4 of the total number of species, the Monocotyledonae by 116 species (23.7 and the Dicotyledonae by 371 species (75.9 .

  20. Trends in savanna structure and composition along an aridity gradient in the Kalahari

    CSIR Research Space (South Africa)

    Scholes, RJ

    2002-06-01

    Full Text Available . Elsewhere, they occupy clayey, alkaline soils derived either from Triassic shales and mudstones, in the valleys of the Zambezi, Limpopo and Cunene rivers and their major tributaries, or from Jurassic basalts. Table 3. Woody plant basal area, canopy cover.... FAO, Rome, IT. Childes, S.I. & Walker, B.H. 1987. Ecology and dynamics of the woody vegetation on the Kalahari sands in Hwange National Park, Zimbabwe. Vegetatio 72: 111-128. Cole, M.M. & Brown, R.C. 1976. The vegetation of the Ghanzi area of western...

  1. Further records of smaller mammals from the Kalahari Gemsbok National Park

    Directory of Open Access Journals (Sweden)

    I.L. Rautenbach

    1975-07-01

    Full Text Available An earlier paper (Rautenbach 1971 summarized documented distributional data on the smaller mammals in the Kalahari Gemsbok National Park, Republic of South Africa. Since then continued field- work in this Park (e.g. Nel and Rautenbach in press has yielded more information on the distribution of some previously recorded species,whilst other species have been recorded for the first time. Collecting hasbeen concentrated on two localities in the vicinity of Twee Rivieren, two near Nossob Camp, as well as at Dankbaar in the north-central portion of the Park.

  2. Kalahari salt pans as sedimentary archives for reconstruction of Quaternary environments

    Science.gov (United States)

    Schüller, Irka; Belz, Lukas; Wilkes, Heinz; Wehrmann, Achim

    2015-04-01

    Environmental changes in southern Africa come along with variations in atmospheric and oceanic circulation as well as anthropogenic caused landuse changes. The reconstruction of the paleoenvironment is complicated by the fact that continuous geoarchives are rare in the semiarid to arid parts of this region. In the south-western Kalahari lacustrine systems with constant sedimentary records are absent due to the low precipitation. Salt pans are common geomorphological structures in the Kalahari which are temporarily flooded during summer season when isolated showers occur in their local catchment area. So, they are potential archives preserving environmental signals in phases of sedimentation. However, marginal dunes on their leeward sides represent phases of deflation. The principle processes in salt pan formation are complex and so far under discussion. Our study follows a multidisciplinary approach integrating sedimentological, geochemical and microbiological methods to understand the formation of salt pans as a prerequisite for using them as geoarchives in reconstruction of the paleoenvironmental condition during phases of sedimentation and erosion. Sediment cores from five salt pans were analysed using XRD, XRF and grain size analyses. Additionally, age models can be given for four salt pans, based on δ14C from bulk sediment TOC. As palynological material is lacking, different methods in organic geochemistry were applied (plant biomarkers, particularly leaf wax n-alkanes and n-alcohols and their stable carbon and hydrogen isotopic signatures) to reconstruct variations in local vegetation assemblages. Our results allow a better understanding of the sedimentology of salt pans and their interpretation as discontinuous archives.

  3. Aspects of the ecology and the behaviour of the Leopard Panthera pardus in the Kalahari desert

    Directory of Open Access Journals (Sweden)

    J du P Bothma

    1984-12-01

    Full Text Available Tracking in sand revealed data on hunting and kill rates, range, movements, activity, cover and water use, reproduction and interactions with other carnivores, by the leopard Panthera pardus in the Kalahari Gemsbok National Park. For leopards in the interior, 812,5 km of tracks were followed for 54 days, and 205,1 km for 15 days for females with cubs. In the Nossob riverbed 30,2 km of tracks were folowed in eight days. Medium-sized mammals featured prominently in the diet of all leopards, with prey used influenced by habitat type. Leopards in the interior moved greater distances than those in the Nossob riverbed. Leopards rested frequently at the onset and end of activity and used dense vegetation and aardvark Orycteropus afer and porcupine Hystrix africaeaustralis burrows as daytime cover. Leopards are independent of water, and females apparently have no definite breeding season. Lions Panthera leo dominate leopards, but the outcome of leopard/spotted hyaena Crocuta crocuta encounters depend on the size of the leopard and the number of hyaenas in the pack. Leopards in the Kalahari Desert are opportunists which occupy this harsh envi- ronment successfully.

  4. Assessment of coalbed gas resources of the Kalahari Basin Province of Botswana, Zimbabwe, and Zambia, Africa, 2016

    Science.gov (United States)

    Brownfield, Michael E.; Schenk, Christopher J.; Klett, Timothy R.; Tennyson, Marilyn E.; Mercier, Tracey J.; Gaswirth, Stephanie B.; Marra, Kristen R.; Hawkins, Sarah J.; Finn, Thomas M.; Le, Phuong A.; Leathers-Miller, Heidi M.

    2017-02-24

    Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean resources of 4.5 trillion cubic feet of coalbed gas in the Kalahari Basin Province of Botswana, Zambia, and Zimbabwe, Africa.

  5. Variations in the Foraging Behaviour and Burrow Structures of the Damara Molerat Cryptomys damarensis in the Kalahari Gemsbok National Park

    Directory of Open Access Journals (Sweden)

    B.G. Lovegrove

    1987-10-01

    Full Text Available Aspects of two habitat-specific foraging behaviours of the social subterranean rodent Cryptomys damarensis, are discussed in terms of burrow structure, resource dispersion patterns, sand moisture content, burrow temperature regimes, and predatory pressures, in the Kalahari Gemsbok National Park, South Africa.

  6. Notes on food and foraging of the Honey Badger Mellivora capensis in the Kalahari Gemsbok National Park

    Directory of Open Access Journals (Sweden)

    H Kruuk

    1983-12-01

    Full Text Available Contents of faeces indicated that honey badgers in the Kalahari eat mostly rodents, followed by lizards and scorpions, all of which are caught by digging. Larger mammals (aardwolf, bat-eared fox, springhare and large snakes are also eaten. Foraging behaviour is described and individual differences in foraging strategies are discussed.

  7. Farmer–African wild dog (Lycaon pictus relations in the eastern Kalahari region of Botswana

    Directory of Open Access Journals (Sweden)

    Valli-Laurente Fraser-Celin

    2017-05-01

    Full Text Available African wild dogs (Lycaon pictus are the most endangered large carnivores in southern Africa. Direct and indirect persecution by farmers causes significant conservation challenges. Farmer– wild dog conflict in Botswana commonly occurs as a result of cattle and stocked game depredation by wild dogs, affecting farmer livelihood and causing economic and emotional distress. Although wild dogs predate livestock at lower levels than other carnivores, they continue to be killed both indiscriminately and in retaliation for incidents of depredation. Investigating farmer–wild dog conflict is a necessary step towards establishing appropriate conflict mitigation strategies. Eighty livestock and game farmers were interviewed in order to examine farmers’ value of, perceptions of and experiences with wild dogs as well as their insights on wild dog impacts and conservation in the eastern Kalahari region of Botswana. Interviews were semi-structured and used open-ended questions to capture complexities surrounding farmer–wild dog relations. This research contributes baseline data on wild dogs in understudied tribal land and commercial livestock and game farms in eastern Kalahari. It confirms the presence of wild dogs, livestock and stocked game depredation by wild dogs and negative perspectives amongst farmers towards wild dogs and their conservation. Mean losses were 0.85 livestock per subsistence farmer, 1.25 livestock per commercial livestock farmer, while game farmers lost 95.88 game animals per farmer during January 2012 through June 2013. Proportionally, more subsistence farmers than commercial livestock farmers and game farmers held negative perspectives of wild dogs (χ ² = 9.63, df = 2, p < 0.05. Farmer type, education level, socioeconomic status and land tenure, as well as positive wild dog characteristics should be considered when planning and operationalising conflict mitigation strategies. As such, conservation approaches should focus on

  8. Strong crustal seismic anisotropy in the Kalahari Craton based on Receiver Functions

    DEFF Research Database (Denmark)

    Thybo, Hans; Soliman, Mohammad Youssof Ahmad; Artemieva, Irina

    2015-01-01

    Earlier seismic studies of the Kalahari Craton in southern Africa infer deformation of upper mantle by flow with fast direction of seismic anisotropy being parallel to present plate motion, and/or report anisotropy frozen into the lithospheric mantle. We present evidence for very strong seismic...... is uniform within tectonic units and parallel to orogenic strike in the Limpopo and Cape fold belts. It is further parallel to the strike of major dyke swarms which indicates that a large part of the observed anisotropy is controlled by lithosphere fabrics and macroscopic effects. The directions of the fast...... that the crust and lithospheric mantle may have been coupled since cratonisation. If so, the apparent match between mantle anisotropy and the present plate motion is coincidental....

  9. Kwaliteit van water wat aan wild in die Kalahari-gemsbok Nasionale Park voorsien word

    Directory of Open Access Journals (Sweden)

    H. van A. Dreyer

    1989-10-01

    Full Text Available Kwaliteit van boorgatwater in die Kalahari-gemsbok Nasionale Park wissel van vars (<5 dele per duisend totale opgeloste soute tot hoogs gemineraliseerd (>10 dpd. Water in krippe waaruit wild drink, het altyd 'n swakker kwaliteit as die uit 'n boorgat of uit 'n dam. Die hoe konsentrasie van soute in kripwater, wat tot gevolg het dat die water van 'n groOt aantal waterpunte as ondrinkbaar vir vee geklassifiseer kan word, word veroorsaak deur volgehoue verdamping uit damme en krippe. Damwater word egter gereeld met "varser" water vanuit boorgate aangevul, maar 'n viotterklep verhoed dit by krippe. Die belangrikste minerale en ione wat in hoe konsentrasies in hierdie waters voorkom, is Na4', SO -, CF, en in enkele gevalle ook C^i++.

  10. Prey selection and feeding habits of the large carnivores in the Southern Kalahari

    Directory of Open Access Journals (Sweden)

    M. G. L Mills

    1984-12-01

    Full Text Available Prey selection and feeding habits of lions Panthera leo, spotted hyaenas Crocuta crocuta, cheetahs Acinonyx jubatus and leopards Panthera pardus are investigated. Lions kill mainly adult gemsbok Oryx gazella and blue wildebeest Connochaetes taurinus, tending to select older animals of both species and males in the case of gemsbok. Spotted hyaenas also prey mainly on gemsbok and wildebeest, but select for juveniles, particularly from gemsbok. Cheetahs prey heavily on springbok Antidorcas marsupialis lambs and then on adult males and older individuals. Leopards also prey relatively heavily on springbok, but appear to have a wider diet than cheetahs do. It is concluded that predators generally have a small impact on their prey populations in the southern Kalahari, although in the case of springbok they do appear to influence the structure of the population.

  11. Strong crustal seismic anisotropy in the Kalahari Craton based on Receiver Functions

    DEFF Research Database (Denmark)

    Thybo, Hans; Soliman, Mohammad Youssof Ahmad; Artemieva, Irina

    2015-01-01

    Earlier seismic studies of the Kalahari Craton in southern Africa infer deformation of upper mantle by flow with fast direction of seismic anisotropy being parallel to present plate motion, and/or report anisotropy frozen into the lithospheric mantle. We present evidence for very strong seismic...... is uniform within tectonic units and parallel to orogenic strike in the Limpopo and Cape fold belts. It is further parallel to the strike of major dyke swarms which indicates that a large part of the observed anisotropy is controlled by lithosphere fabrics and macroscopic effects. The directions of the fast...... that the crust and lithospheric mantle may have been coupled since cratonisation. If so, the apparent match between mantle anisotropy and the present plate motion is coincidental....

  12. In-vitro screening of Kalahari browse species for rumen methane mitigation

    Directory of Open Access Journals (Sweden)

    Jacobus Johannes Francois Theart

    2015-12-01

    Full Text Available The nutritional value of browse foliage from the Thorny Kalahari Dune Bush veld of South Africa is not characterized. Most of this browse species is rich in tannin, but still palatable, and is consumed by ruminants during the dry season, as well as having a role to play in mitigating enteric methane emission from ruminants. In this study, the rumen methane mitigation potential of 19 browse species foliage collected from the Thorny Kalahari Dune Bush veld, was analyzed in terms of chemical composition, in vitro fermentation, digestibility and methane production. In vitro gas and methane production and organic matter digestibility (IVOMD were determined by using rumen fluid collected, strained and anaerobically prepared. A semi-automated system was used to measure gas production (GP from each browse species by incubating 400 mg samples in a shaking incubator at 39 °C with or without inclusion of 400 mg of polyethylene glycol (PEG. Data for all the parameters collected were statistically analyzed using the SAS (9.0 general linear model (GLM procedure, and differences between foliage species were determined using Duncan’s multiple-range test. Acacia luederitziiand Monechma incanumshowed the best potential for decreasing methane production by up to 90 % after 48 h of incubation. The secondary components (mainly tannins of the browse species appeared to have a significant effect on volatile fatty acids (VFA, methane and gas production as judged by the comparison of samples incubated with or without PEG inclusion. The substantial amount of crude protein (CP content coupled with their anti-methanogenic effect during fermentation would make these browses a potential mitigation option for small scale farmers and pastoralists in sub-Sahara Africa. However, it is also very important that systematic and strategic supplementation in a mixed diet should be looked at as the way forward in terms of best utilization.

  13. Fluvial landscape development in the southwestern Kalahari during the Holocene - Chronology and provenance of fluvial deposits in the Molopo Canyon

    Science.gov (United States)

    Ramisch, Arne; Bens, Oliver; Buylaert, Jan-Pieter; Eden, Marie; Heine, Klaus; Hürkamp, Kerstin; Schwindt, Daniel; Völkel, Jörg

    2017-03-01

    The southern Kalahari drainage network is in a key position to analyze spatiotemporal changes in the tropical easterly and the temperate westerly circulation over the Southern African subcontinent. However, due to the prevailing aridity, paleoenvironmental archives within the southwestern Kalahari are sparse and often discontinuous. Hence, little is known about Holocene environmental change in this region. This study focuses on reconstructing paleoenvironmental change from the timing and provenance of fluvial deposits located within the Molopo Canyon, which connects the southern Kalahari drainage to the perennial flow regime of the Orange River. To gain insight into temporal aspects of fluvial morphodynamics within the Molopo Canyon, the entire variety of fluvial landforms consisting mainly of slope sediments, alluvial fans and alluvial fills were dated using Optically Stimulated Luminescence (OSL). We additionally applied a provenance analysis on alluvial fill deposits to estimate potential sediment source areas. Source areas were identified by analyzing the elemental and mineralogical composition of tributaries and eolian deposits throughout the course of the lower Molopo. The results allow the first general classification of fluvial landscape development into three temporally distinct deposition phases in the southern Kalahari: (1) A phase of canyon aggradation associated with short lived and spatially restricted flash floods during the early to mid-Holocene; (2) a phase of fan aggradation indicating a decrease in flood intensities during the mid- to late Holocene; and (3) a phase of canyon aggradation caused by the occurrence of supra-regional flood events during the Little Ice Age. We interpret the observed spatiotemporal deposition patterns to latitudinal shifts of the tropical easterly circulation in the early to mid-Holocene and the temperate westerly circulation in the late Holocene. However, despite marked changes in the provenance and timing of fluvial

  14. GPS-corrected and GIS-based remapping of the Kalahari Gemsbok National Park and the adjacent area in Botswana

    Directory of Open Access Journals (Sweden)

    J. du P. Bothma

    1993-09-01

    Full Text Available GPS-equipment was used to map the interior roads, major pans and the location of all windmills and solar-equipped boreholes in the Kalahari Gemsbok National Park and the adjacent areas of Botswana. The final map was generated with GIS-equipment, and supplies managers and planners with the first error-free map of the area. The major errors of previous maps are indicated.

  15. Wetting Splashing

    CERN Document Server

    Tsai, Peichun; Dijkstra, Remko; Lohse, Detlef

    2010-01-01

    We present fluid dynamics videos illustrating wetting splashing-produced by water drop impact onto hydrophobic microstructures at high impact velocity ($\\sim 3$ ms$^{-1}$). The substrate consists of regular and transparent microtextures in square or hexagonal lattice, yielding a high contact angle of $\\sim 150 ^\\circ$. Our high speed top-or-bottom view recordings through the transparent surface shed light on the solid-liquid-air interfaces at impact. Despite the superhydrophobicity of the latticed micropillars (of a periodicity of $10 {\\mu}m), water droplet wets a certain central area and moreover entraps an air bubble beneath the droplet. Besides the central wet area, lamella surf on air splashing outward at high impinging velocity. The effects of micropatterns and air pressure on the impact outcome are also examined. We show that microscopic boundary condition, imposed by the solid texture, profoundly influences the macroscopic flow dynamics upon superhydrophobic surfaces at high impinging velocity. In addi...

  16. Pollen analysis of hyena coprolites and sediments from Equus Cave, Taung, southern Kalahari (South Africa)

    Science.gov (United States)

    Scott, Louis

    1987-07-01

    Equus Cave, in Quaternary tufa near Taung in the semiarid woodland of the southern Kalahari, yielded 2.5 m of sediment in which a rich assemblage of bones and coprolites was preserved. The fossils were accumulated mainly by hyenas during the late Pleistocene and Holocene. Pollen from coprolites reflects diet as well as vegetation over relatively large areas visited by hyenas, while pollen from sediments represents more local sources. The pollen sequence derived from coprolites and sediments demonstrates how the vegetation evolved from open grassland with small shrubs and occasional trees during the late Pleistocene, to open savanna with more small shurbs, then, during the last 7500 yr, to modern savanna. Temperatures were not more than 4°C cooler and it was slightly moister than today during the late Pleistocene phase; it became gradually warmer but relatively dry before optimal temperature and moisture conditions developed around 7500 yr B.P. Climatic conditions slightly less favorable for woodland occurred during part of the late Holocene.

  17. Fluvial landscape development in the southwestern Kalahari during the Holocene - Chronology and provenance of fluvial deposits in the Molopo Canyon

    DEFF Research Database (Denmark)

    Ramisch, Arne; Bens, Oliver; Buylaert, Jan-Pieter

    2017-01-01

    general classification of fluvial landscape development into three temporally distinct deposition phases in the southern Kalahari: (1) A phase of canyon aggradation associated with short lived and spatially restricted flash floods during the early to mid-Holocene; (2) a phase of fan aggradation indicating...... a decrease in flood intensities during the mid- to late Holocene; and (3) a phase of canyon aggradation caused by the occurrence of supra-regional flood events during the Little Ice Age. We interpret the observed spatiotemporal deposition patterns to latitudinal shifts of the tropical easterly circulation...

  18. Estimating aboveground biomass in Kalahari woodlands: inferring soil erosional and distributional processes

    Science.gov (United States)

    Wingate, Vladimir

    2017-04-01

    Maps which accurately quantify vegetation carbon, or above ground biomass (AGB) and its changes, are not only essential for ecosystem monitoring, but also for understanding controls on ecosystem carbon, associated soil organic carbon (SOC) and the global carbon cycle. Throughout the rangelands of Namibia, two vegetation cover change processes are widespread, firstly, deforestation and forest degradation, and secondly, the encroachment of the herbaceous and grassy layers by woody strata. Both processes effect a range of key ecosystem services, including SOC dynamics by facilitating erosion and altering soil re-distributional processes. Yet, the spatial and temporal intensity of these vegetation change processes and hence their effect on SOC, remain poorly quantified. This study therefore aims to distinguish and map the extent of both deforestation and woody thickening and associated AGB changes, and gain an understanding of the spatial distribution of land degradation risk areas. We map AGB at two periods (2007 and 2015) for part of the Namibian Kalahari woodland savannah, by modelling forest inventory measurements as a function of a fusion of radar and optical satellite imagery. We then process a change detection and validate both individual and change maps using independent field and satellite data. Results show widespread increases and declines in both areal extent and quantity of AGB, suggesting (i) important vegetation change processes (i.e. both deforestation and woody thickening), and (ii) associated changes in soil quality. Indeed, woody thickening has been found to mask land degradation, through the replacement of herbaceous layers with hardy shrubs, leading to increases in erosional processes. These results are in agreement with previous studies, which identify both extensive greening and small-scale deforestation. Keywords: Soil Organic Carbon, Erosion, deposition, Above Ground Biomass; Savannah; Rangeland; Carbon; Remote Sensing; Change detection

  19. Late Pleistocene-Holocene vegetation and climate change in the Middle Kalahari, Lake Ngami, Botswana

    Science.gov (United States)

    Cordova, Carlos E.; Scott, Louis; Chase, Brian M.; Chevalier, Manuel

    2017-09-01

    Pollen, spores, and microscopic charcoal from a sediment core from Lake Ngami, in the Middle Kalahari, reflect paleovegetation and paleoclimatic conditions over the last 16,600 cal years BP. The location of Lake Ngami allows for the receipt of moisture sourced from the Indian and/or Atlantic oceans, which may have influenced local rainfall or long distance water transport via the Okavango system. We interpret results of statistical analyses of the pollen data as showing a complex, dynamic system wherein variability in tropical convective systems and local forcing mechanisms influence hydrological changes. Our reconstructions show three primary phases in the regional precipitation regime: 1) an early period of high but fluctuating summer rainfall under relatively cool conditions from ∼16,600-12,500 cal BP, with reduced tree to herb and shrub ratio; 2) an episode of significantly reduced rainfall centered around c. 11,400 cal BP, characterized by an increase in xeric Asteraceae pollen, but persistent aquatic elements, suggesting less rainfall but cool conditions and lower evaporation that maintained water in the basin; and 3) a longer phase of high, but fluctuating rainfall from ∼9000 cal BP to present with more woody savanna vegetation (Vachellia (Acacia) and Combretaceae). We propose a model to relate these changes to increased Indian Ocean-sourced moisture in the late Pleistocene due to a southerly position of the African rain belt, a northerly contraction of tropical systems that immediately followed the Younger Dryas, and a subsequent dominance of local insolation forcing, modulated by changes in the SE Atlantic basin.

  20. Exit Creek Transect Survey, June 2013

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset consists of survey data from transects surveyed June 10-12, 2013 along Exit Creek, a stream draining Exit Glacier in Kenai Fjords National Park, Alaska....

  1. Moist soil vegetative transect results - 1985

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Moist soil impoundment (MSI) construction at Duck River unit was completed in 1985 and water management was initiated. Permanent transects were established within...

  2. The Late Pleistocene and Holocene palaeoenvironmental context of Wonderwerk Cave in the southern Kalahari, South Africa

    Science.gov (United States)

    Scott, Louis; Avery, Margaret; Bamford, Marion; Berna, Francesco; Brink, James; Brook, George; Chazan, Michael; Ecker, Michaela; Fernandez-Jalvo, Yolanda; Goldberg, Paul; Lee-Thorp, Julia; Rossouw, Lloyd; Thackeray, Francis; Horwitz, Liora

    2014-05-01

    Wonderwerk Cave, located in the arid southern Kalahari in South Africa, is an exceptional site, since it preserves a two million year long record of human occupation. While research on older levels in various excavation sections of the cave deposits is ongoing, we focus here on the younger levels that span the last 35,000 years. We present the results of past and recent work on zooarchaeology, macrobotany, palynology, phytoliths, stable isotopes, micromorphology and speleothem growth, which track marked diachronic environmental fluctuations. Except for a hiatus of ~33-23 ka, growth and isotope data for a speleothem near the cave entrance suggests moist conditions from ~35-33, and ~22-14 ka with brief, dry episodes at ~34, ~22 and ~15 ka. Temperatures were cool except for an increase ~16-14 ka after which cold conditions equivalent to the Younger Dryas event occurred. In Stratum 5 (>12.5 ka in Excavation 1), relatively low carbon isotope (δ13C) values, pollen in the speleothem, and pollen in dung deposits indicate that the vegetation included a large C3 component during this phase. While the climate experienced sharp fluctuations in moisture when stalagmite growth was interrupted, more severe drying occurred by ~12 ka as indicated by dung pollen. Pollen in Stratum 4d (undifferentiated by stratum sub-phases) suggest that warmer grassy conditions developed before 11 ka, which is supported by δ13C values in OES that suggest a greater C4plant component in Stratum 4dII associated with the Oakhurst-like archaeological industry. Undifferentiated Stratum 4d indicates moderate moisture availability (pollen) but sub-phase 4dII suggest drying (OES δ18O). C3-presence (OES δ13C) in the vegetation became stronger again in Stratum 4dI (Oakhurst) and Stratum 4cII (Wilton). This is supported by Asteraceae pollen especially ~8.5 ka. Except for a fluctuation in OES δ18O values in Stratum 4cII, δ18O and pollen and micromammal composition suggest progressive aridity until ~6 ka

  3. Southern African continental climate since the late Pleistocene: Insights from biomarker analyses of Kalahari salt pan sediments

    Science.gov (United States)

    Belz, Lukas; Schüller, Irka; Wehrmann, Achim; Wilkes, Heinz

    2016-04-01

    The climate system of sub-tropical southern Africa is mainly controlled by large scale atmospheric and marine circulation processes and, therefore, very sensitive to global climate change. This underlines the importance of paleoenvironmental reconstructions in order to estimate regional implications of current global changes. However, the majority of studies on southern African paleoclimate are based on the investigation of marine sedimentary archives and past climate development especially in continental areas is still poorly understood. This emphasizes the necessity of continental proxy-data from this area. Proxy datasets from local geoarchives especially of the southwestern Kalahari region are still scarce. A main problem is the absence of conventional continental climatic archives, due to the lack of lacustrine systems. In this study we are exploring the utility of sediments from western Kalahari salt pans, i.e. local depressions which are flooded temporarily during rainfall events. An age model based on 14C dating of total organic carbon (TOC) shows evidence that sedimentation predominates over erosional processes with respect to pan formation. Besides the analyses of basic geochemical bulk parameters including TOC, δ13CTOC, total inorganic carbon, δ13CTIC, δ18OTIC, total nitrogen and δ15N, our paleo-climatic approach focuses on reconstruction of local vegetation assemblages to identify changes in the ecosystem. This is pursued using plant biomarkers, particularly leaf wax n-alkanes and n-alcohols and their stable carbon and hydrogen isotopic signatures. Results show prominent shifts in n-alkane and n-alkanol distributions and compound specific carbon isotope values, pointing to changes to a more grass dominated environment during Heinrich Stadial 1 (18.5-14.6 ka BP), while hydrogen isotope values suggest wetter phases during Holocene and LGM. This high variability indicates the local vulnerability to global change.

  4. Transect 20:3 (winter 2002)

    OpenAIRE

    2002-01-01

    IN THIS ISSUE OF TRANSECT - (feature article) Microbial Observatories Reveal Lively Little-Known Worlds Beneath the Surfaces of Land and Lake - Innovative Nesting Program at Coal Oil Point Reserve Proves Great Success - Stunt Ranch Reserve Looks Forward to New Facilities - Field Course Students from Minnesota Discover California Ecology at NRS Reserves

  5. Appendiceal transection associated with seat belt restraint.

    Science.gov (United States)

    Go, Seung Je; Sul, Young Hoon; Ye, Jin Bong; Kim, Joong Suck

    2016-08-01

    The seat belt is designed for safety in a motor vehicle and should be worn to prevent severe injuries. But, the seat belt itself can be an injury factor in combination with deceleration forces applied to fixation points of mobile viscera. Here, we present a 23-year-man with traumatic transection of the appendix, highly mobile viscera, following seat belt injury.

  6. Consequences of Neurite Transection In Vitro

    Science.gov (United States)

    Cengiz, Nurettin; Erdoğan, Ender; Him, Aydın; Oğuz, Elif Kaval

    2012-01-01

    Abstract In order to quantify degenerative and regenerative changes and analyze the contribution of multiple factors to the outcome after neurite transection, we cultured adult mouse dorsal root ganglion neurons, and with a precise laser beam, we transected the nerve fibers they extended. Cell preparations were continuously visualized for 24 h with time-lapse microscopy. More distal cuts caused a more elongated field of degeneration, while thicker neurites degenerated faster than thinner ones. Transected neurites degenerated more if the uncut neurites of the same neuron simultaneously degenerated. If any of these uncut processes regenerated, the transected neurites underwent less degeneration. Regeneration of neurites was limited to distal cuts. Unipolar neurons had shorter regeneration than multipolar ones. Branching slowed the regenerative process, while simultaneous degeneration of uncut neurites increased it. Proximal lesions, small neuronal size, and extensive and rapid neurite degeneration were predictive of death of an injured neuron, which typically displayed necrotic rather than apoptotic form. In conclusion, this in vitro model proved useful in unmasking many new aspects and correlates of mechanically-induced neurite injury. PMID:20121423

  7. Duodenal Transection without Pancreatic Injury following Blunt ...

    African Journals Online (AJOL)

    Journal of Surgical Technique and Case Report | Jul-Dec 2014 | Vol-6 | Issue-2. 67. Duodenal Transection ... Early interventions in duodenal injuries have improved outcome. Here we report a ... developed abdominal pain along with single episode of ... challenge to the surgeon and failure to manage it properly can result in ...

  8. Impact of Prosopis invasion on a keystone tree species in the Kalahari Desert

    CSIR Research Space (South Africa)

    Schachtschneider, K

    2013-04-01

    Full Text Available and canopy dieback were conducted using 142 Statistica 8.0. We used Student T-tests and one-way ANOVA’s with Tukey post hoc tests to detect any 143 6 significant differences (p < 0.05). A non-parametric Kruskall-Wallis test was used when assumptions... and groundwater (Fig. 3a). At the end of the wet season A. erioloba xylem 172 7 water isotope ratios differ significantly from groundwater (Kruskall-Wallis nonparametric δ18O; p < 173 0.001). There are no significant differences between A. erioloba xylem...

  9. CRED REA Fish Team Belt Transect Survey at Laysan 2004

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 3 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 3 sites at Laysan in the Northwest...

  10. Modeled Wet Nitrate Deposition

    Data.gov (United States)

    U.S. Environmental Protection Agency — Modeled data on nitrate wet deposition was obtained from Dr. Jeff Grimm at Penn State Univ. Nitrate wet depostion causes acidification and eutrophication of surface...

  11. Vaginitis test - wet mount

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003916.htm Vaginitis test - wet mount To use the sharing features on this page, please enable JavaScript. The vaginitis wet mount test is a test to detect ...

  12. Analyses of Recent Sediment Surface Dynamic of a Namibian Kalahari Salt Pan Based on Multitemporal Landsat and Hyperspectral Hyperion Data

    Directory of Open Access Journals (Sweden)

    Robert Milewski

    2017-02-01

    Full Text Available This study combines spaceborne multitemporal and hyperspectral data to analyze the spatial distribution of surface evaporite minerals and changes in a semi-arid depositional environment associated with episodic flooding events, the Omongwa salt pan (Kalahari, Namibia. The dynamic of the surface crust is evaluated by a change-detection approach using the Iterative-reweighted Multivariate Alteration Detection (IR-MAD based on the Landsat archive imagery from 1984 to 2015. The results show that the salt pan is a highly dynamic and heterogeneous landform. A change gradient is observed from very stable pan border to a highly dynamic central pan. On the basis of hyperspectral EO-1 Hyperion images, the current distribution of surface evaporite minerals is characterized using Spectral Mixture Analysis (SMA. Assessment of field and image endmembers revealed that the pan surface can be categorized into three major crust types based on diagnostic absorption features and mineralogical ground truth data. The mineralogical crust types are related to different zones of surface change as well as pan morphology that influences brine flow during the pan inundation and desiccation cycles. These combined information are used to spatially map depositional environments where the more dynamic halite crust concentrates in lower areas although stable gypsum and calcite/sepiolite crusts appear in higher elevated areas.

  13. Traumatic globe luxation with optic nerve transection.

    Science.gov (United States)

    Bajaj, Mandeep S.; Kedar, Sachin; Sethi, Anita; Gupta, Vishal

    2000-09-01

    Luxation of the globe is a rare event that results from severe trauma to the orbit, often causing orbital rim and wall fractures. Though associated globe rupture often necessitates enucleation, repositioning of the globe can be attempted in these cases if the globe is intact. We report a case of globe luxation and optic nerve transection with its surgical management. A 17-year-old male presented with anterior luxation of the right globe and optic nerve transection following blunt trauma to the orbit. Computerized tomography revealed an anteriorly subluxated globe with complete transection of the optic nerve and multiple fractures of the orbital walls. The orbit was explored and the globe repositioned in the orbit with reattachment of the muscles. Postoperatively, the globe was in normal position with moderate motility and excellent overall cosmesis. Though the visual prognosis in these cases is usually extremely poor and depends on the extent and duration of injury, preservation of the globe not only helps the patient recover psychologically from the trauma but also allows better cosmesis.

  14. Ecohydrological optimality in the Northeast China Transect

    Science.gov (United States)

    Cong, Zhentao; Li, Qinshu; Mo, Kangle; Zhang, Lexin; Shen, Hong

    2017-05-01

    The Northeast China Transect (NECT) is one of the International Geosphere-Biosphere Program (IGBP) terrestrial transects, where there is a significant precipitation gradient from east to west, as well as a vegetation transition of forest-grassland-desert. It is remarkable to understand vegetation distribution and dynamics under climate change in this transect. We take canopy cover (M), derived from Normalized Difference Vegetation Index (NDVI), as an index to describe the properties of vegetation distribution and dynamics in the NECT. In Eagleson's ecohydrological optimality theory, the optimal canopy cover (M*) is determined by the trade-off between water supply depending on water balance and water demand depending on canopy transpiration. We apply Eagleson's ecohydrological optimality method in the NECT based on data from 2000 to 2013 to get M*, which is compared with M from NDVI to further discuss the sensitivity of M* to vegetation properties and climate factors. The result indicates that the average M* fits the actual M well (for forest, M* = 0.822 while M = 0.826; for grassland, M* = 0.353 while M = 0.352; the correlation coefficient between M and M* is 0.81). Results of water balance also match the field-measured data in the references. The sensitivity analyses show that M* decreases with the increase of leaf area index (LAI), stem fraction and temperature, while it increases with the increase of leaf angle and precipitation amount. Eagleson's ecohydrological optimality method offers a quantitative way to understand the impacts of climate change on canopy cover and provides guidelines for ecorestoration projects.

  15. Fractured cervical spine and aortic transection.

    LENUS (Irish Health Repository)

    Griffin, M J

    2012-02-03

    A 17-year-old victim of a road traffic accident presented. Following investigation diagnoses of fractured first cervical vertebra, aortic transection, diffuse cerebral oedema, fractured right ribs 2-4 and pubic rami were made. Management of this case presented a number of anaesthetic dilemmas: management of the airway, use of cross-clamp vs. shunting or heparinization and bypass, cardiovascular and neurological monitoring, maintenance of cardiovascular stability during and post cross-clamp, minimizing the risk of post-operative renal and neurological dysfunction.

  16. Use of advanced earth observation tools for the analyses of recent surface changes in Kalahari pans and Namibian coastal lagoons

    Science.gov (United States)

    Behling, Robert; Milewski, Robert; Chabrillat, Sabine; Völkel, Jörg

    2016-04-01

    The remote sensing analyses in the BMBF-SPACES collaborative project Geoarchives - Signals of Climate and Landscape Change preserved in Southern African Geoarchives - focuses on the use of recent and upcoming Earth Observation Tools for the study of climate and land use changes and its impact on the ecosystem. It aims at demonstrating the potential of recently available advanced optical remote sensing imagery with its extended spectral coverage and temporal resolution for the identification and mapping of sediment features associated with paleo-environmental archives as well as their recent dynamic. In this study we focus on the analyses of two ecosystems of major interest, the Kalahari salt pans as well as the lagoons at Namibia's west coast, that present high dynamic caused by combined hydrological and surface processes linked to climatic events. Multitemporal remote sensing techniques allow us to derive the recent surface dynamic of the salt pans and also provide opportunities to get a detailed understanding of the spatiotemporal development of the coastal lagoons. Furthermore spaceborne hyperspectral analysis can give insight to the current surface mineralogy of the salt pans on a physical basis and provide the intra pan distribution of evaporites. The soils and sediments of the Kalahari salt pans such as the Omongwa pan are a potentially significant storage of global carbon and also function as an important terrestrial climate archive. Thus far the surface distribution of evaporites have been only assessed mono-temporally and on a coarse regional scale, but the dynamic of the salt pans, especially the formation of evaporites, is still uncertain and poorly understood. For the salt pan analyses a change detection is applied using the Iterative-reweighted Multivariate Alteration Detection (IR-MAD) method to identify and investigate surface changes based on a Landsat time-series covering the period 1984-2015. Furthermore the current spatial distribution of

  17. Wet oxidation of quinoline

    DEFF Research Database (Denmark)

    Thomsen, A.B.; Kilen, H.H.

    1998-01-01

    The influence of oxygen pressure (0.4 and 2 MPa). reaction time (30 and 60 min) and temperature (260 and 280 degrees C) on the wet oxidation of quinoline has been studied. The dominant parameters for the decomposition of quinoline were oxygen pressure and reaction temperature. whereas the reaction...... time was less important within the range studied. Nitrifying bacteria were used to measure the inhibition from wet oxidative-treated samples to study the effect of the (wet oxidation) reaction conditions. Wet oxidation made quinoline more toxic to Nitrosomonas. This was observed for Nitrobacter as well....... The combined wet oxidation and biological treatment of reaction products resulted in 91% oxidation of the parent compound to CO2 and water. Following combined wet oxidation and biological treatment the sample showed low toxicity towards Nitrosomonas and no toxicity towards Nitrobacter. (C) 1998 Elsevier...

  18. Non-transecting anastomotic urethroplasty (surgical atlas

    Directory of Open Access Journals (Sweden)

    S. V. Kotov

    2015-01-01

    Full Text Available Non-transecting anastomotic urethroplasty – is three types of urethroplasty, which are united on the principle resection of bulbar urethra with sparing of corpus spongiosum and antegrade blood flow through it. The article describes the surgical technique of urethroplasty: dorsal strictureplasty by Heineke–Mikulicz; strictureplasty by Mundy; vessel-sparing anastomotic urethroplasty by Jordan. Obligatory conditions of the non-transecting anastomotic urethroplasty are a non traumatic etiology, length of the stricture not more than 1–1.5 cm, and its localization in the proximal bulbar urethra. Strictureplasty by Heineke–Mikulicz is a dorsal longitudinal incision of the urethra on the area of stricture and subsequent suturing the defect transversely. Strictureplasty by Mundy is a dorsal longitudinal urethrotomy, excision of the affected mucosa inside the lumen of the urethra and transversely urethral closure according to Heineke–Mikulicz, s principle. Vessel-sparing anastomotic urethroplasty by Jordan is circular excision of the urethral mucosa without crossing of corpus spongiosum and incoming into it bulbar arteries and thereby preserving the antegrade blood flow through the urethra.

  19. Inorganic nitrogen wet deposition: Evidence from the North-South Transect of Eastern China.

    Science.gov (United States)

    Zhan, X; Yu, G; He, N; Jia, B; Zhou, M; Wang, C; Zhang, J; Zhao, G; Wang, S; Liu, Y; Yan, J

    2015-09-01

    We examined the spatio-temporal variation of dissolved inorganic nitrogen (DIN) deposition in eight typical forest ecosystems of Eastern China for three consecutive years. DIN deposition exhibited an increasing gradient from north to south, with N-NH4(+) as the predominant contributor. DIN deposition in precipitation changed after interaction with the forest canopy, and serious ecological perturbations are expected in this region. DIN deposition presented seasonal fluctuations, which might be ascribed to agricultural activity, fossil-fuel combustion and environmental factors (i.e., wind direction, soil temperature). Notably, N fertilizer use (FN), energy consumption (E), and precipitation (P) jointly explained 84.3% of the spatial variation in DIN deposition, of which FN (27.2%) was the most important, followed by E (24.8%), and finally P (9.3%). The findings demonstrate that DIN deposition is regulated by precipitation mainly via anthropogenic N emissions, and this analysis provides decision-makers a novel view for N pollution abatement.

  20. WetVegEurope

    NARCIS (Netherlands)

    Landucci, Flavia; Řezníčková, Marcela; Šumberová, Kateřina; Hennekens, S.M.; Schaminée, J.H.J.

    2015-01-01

    WetVegEurope is a research project (http://www.sci.muni.cz/botany/vegsci/wetveg) whose goal is to provide a synthesized formalized classification of the aquatic and marsh vegetation across Europe at the level of phytosociological associations. In order to achieve the project objective, a WetVegEu

  1. Wetting Transition in Water

    Science.gov (United States)

    Friedman, S. R.; Khalil, M.; Taborek, P.

    2013-11-01

    Optical images were used to study the wetting behavior of water on graphite, sapphire, and quartz along the liquid vapor coexistence curve from room temperature to 300°C. Wetting transitions were identified by the temperature at which the contact angle decreased to zero and also by the disappearance of dropwise condensation. These two methods yielded consistent values for the wetting temperatures, which were 185°C, 234°C, and 271°C for water on quartz, sapphire, and graphite, respectively. We compare our results with the theoretical predictions based on a simplified model of the water-substrate potential and sharp interfaces.

  2. Design unbiased estimation in line intersect sampling using segmented transects

    Science.gov (United States)

    David L.R. Affleck; Timothy G. Gregoire; Harry T. Valentine; Harry T. Valentine

    2005-01-01

    In many applications of line intersect sampling. transects consist of multiple, connected segments in a prescribed configuration. The relationship between the transect configuration and the selection probability of a population element is illustrated and a consistent sampling protocol, applicable to populations composed of arbitrarily shaped elements, is proposed. It...

  3. Multidetector CT Findings of Bowel Transection in Blunt Abdominal Trauma

    NARCIS (Netherlands)

    Cho, H.S.; Woo, J.Y.; Hong, H.S.; Park, M.H.; Ha, H.I.; Yang, I.; Lee, Y.; Jung, A.Y.; Hwang, J.Y.

    2013-01-01

    OBJECTIVE: Though a number of CT findings of bowel and mesenteric injuries in blunt abdominal trauma are described in literature, no studies on the specific CT signs of a transected bowel have been published. In the present study we describe the incidence and new CT signs of bowel transection in blu

  4. Adsorption and wetting.

    NARCIS (Netherlands)

    Schlangen, L.J.M.

    1995-01-01

    Adsorption and wetting are related phenomena. In order to improve knowledge of both and their relations, experiments, thermodynamics and a theoretical interpretation have been connected, starring n-alkanes.Starting from the Gibbs adsorption equation thermodynamic relations between vapour adsorption

  5. Wet hydrate dissolution plant

    OpenAIRE

    Stanković Mirjana S.; Kovačević Branimir T.; Pezo Lato L.

    2003-01-01

    The IGPC Engineering Department designed basic projects for a wet hydrate dissolution plant, using technology developed in the IGPC laboratories. Several projects were completed: technological, machine, electrical, automation. On the basis of these projects, a production plant with capacity of 50,000 t/y was manufactured, at "Zeolite Mira", Mira (VE), Italy, in 1997, for increasing detergent zeolite production from 50,000 to 100,000 t/y. Several goals were realized by designing a wet hydrate ...

  6. Measure of pancreas transection and postoperative pancreatic fistula.

    Science.gov (United States)

    Takahashi, Shinichiro; Gotohda, Naoto; Kato, Yuichiro; Konishi, Masaru

    2016-05-15

    In pancreaticoduodenectomy (PD), a standard protocol for pancreas transection has not been established although the method of pancreas transection might be involved in the occurrence of postoperative pancreatic fistula (POPF). This study aimed to compare whether pancreas transection by ultrasonically activated shears (UAS) or that by scalpel contributed more to POPF development. A prospective database of 171 patients who underwent PD for periampullary tumor at National Cancer Center Hospital East between January 2010 and June 2013 was reviewed. Among the 171 patients, 93 patients with soft pancreas were specifically included in this study. Surgical results and background were compared between patients with pancreas transection by UAS and scalpel to evaluate the effectiveness of UAS on reducing POPF. Body mass index, main pancreatic duct diameter, or other clinicopathologic factors that have been reported as predictive factors for POPF were not significantly different between the two groups. The incidence of all grades of POPF and that of grade B were significantly lower in the scalpel group (52%, 4%) than in the UAS group (74%, 42%). Postoperative complications ≥ grade III were also significantly fewer in the scalpel group. Scalpel transection was less associated with POPF than UAS transection in patients who underwent PD for soft pancreas. The method of pancreas transection plays an important role in the prevention of clinical POPF. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Changes in Herbaceous Species Composition in the Absence of Disturbance in a Cenchrus biflorus Roxb. Invaded Area in Central Kalahari Game Reserve, Botswana

    Directory of Open Access Journals (Sweden)

    Shimane W. Makhabu

    2012-01-01

    Full Text Available A-nine year study was carried out to investigate changes in herbaceous species composition in an area invaded by Cenchrus biflorus Roxb, an exotic invader grass species. The study ensued termination of livestock and human activities in the area when residents of the area were relocated to another area. Vegetation characteristics from the disturbed sites (previous occupied areas and undisturbed sites (previously unoccupied areas were determined. The results show that C. biflorus has high tolerance to disturbance. It comprised the larger proportion of grasses in disturbed sites at the inception of the study. However, it decreased in abundance with time in disturbed areas and was absent in the undisturbed areas, suggesting that its ability to invade undisturbed sites is limited. Perennial species successfully reestablished on the third year after termination of disturbance. The study reveals that C. biflorus invasion in the Kalahari ecosystem can be controlled by termination of disturbances.

  8. Faecal helminth egg and oocyst counts of a small population of African lions (Panthera leo in the southwestern Kalahari, Namibia : research communication

    Directory of Open Access Journals (Sweden)

    Y. Smith

    2006-09-01

    Full Text Available An endoparasite survey of a small pride of African lions (Panthera leo was conducted at Intu Afrika Kalahari Game Reserve, southwestern Namibia, during winter and summer of 2003 and 2004, respectively. Overall, 23 fresh lion scats were collected opportunistically during fieldwork trials. A flotation technique was employed for the diagnosis of parasites. Three nematodes, Ancylostoma braziliense, Gnathostoma spinigerum and Uncinaria stenocephala and two coccidians, Toxoplasma gondii and Isospora felis were recorded. By using the McMaster method for quantification, a maximum number of 14 866 oocysts per gram of faeces was obtained for I. felis during winter 2003. Endoparasite taxa carried by the different individuals in the pride were found to be related to their levels of association. Rates of infection were relatively low as a result of the habitat, semi-captive conditions and earlier sporadic deworming.

  9. Analyses of the soil surface dynamic of South African Kalahari salt pans based on hyperspectral and multitemporal data

    Science.gov (United States)

    Milewski, Robert; Chabrillat, Sabine; Behling, Robert; Mielke, Christian; Schleicher, Anja Maria; Guanter, Luis

    2016-04-01

    The consequences of climate change represent a major threat to sustainable development and growth in Southern Africa. Understanding the impact on the geo- and biosphere is therefore of great importance in this particular region. In this context the Kalahari salt pans (also known as playas or sabkhas) and their peripheral saline and alkaline habitats are an ecosystem of major interest. They are very sensitive to environmental conditions, and as thus hydrological, mineralogical and ecological responses to climatic variations can be analysed. Up to now the soil composition of salt pans in this area have been only assessed mono-temporally and on a coarse regional scale. Furthermore, the dynamic of the salt pans, especially the formation of evaporites, is still uncertain and poorly understood. High spectral resolution remote sensing can estimate evaporite content and mineralogy of soils based on the analyses of the surface reflectance properties within the Visible-Near InfraRed (VNIR 400-1000 nm) and Short-Wave InfraRed (SWIR 1000-2500 nm) regions. In these wavelength regions major chemical components of the soil interact with the electromagnetic radiation and produce characteristic absorption features that can be used to derive the properties of interest. Although such techniques are well established for the laboratory and field scale, the potential of current (Hyperion) and upcoming spaceborne sensors such as EnMAP for quantitative mineralogical and salt spectral mapping is still to be demonstrated. Combined with hyperspectral methods, multitemporal remote sensing techniques allow us to derive the recent dynamic of these salt pans and link the mineralogical analysis of the pan surface to major physical processes in these dryland environments. In this study we focus on the analyses of the Namibian Omongwa salt pans based on satellite hyperspectral imagery and multispectral time-series data. First, a change detection analysis is applied using the Iterative

  10. Microbial community composition of transiently wetted Antarctic Dry Valley soils

    Directory of Open Access Journals (Sweden)

    Thomas D. Neiderberger

    2015-01-01

    Full Text Available During the summer months, wet (hyporheic soils associated with ephemeral streams and lake edges in the Antarctic Dry Valleys (DV become hotspots of biological activity and are hypothesized to be an important source of carbon and nitrogen for arid DV soils. Recent research in the DV has focused on the geochemistry and microbial ecology of lakes and arid soils, with substantially less information being available on hyporheic soils. Here we determined the unique properties of hyporheic microbial communities, resolved their relationship to environmental parameters and to compared them to archetypal arid DV soils. Generally, pH increased and chlorophyll a concentrations decreased along transects from wet to arid soils (9.0 to ~7.0 for pH and ~0.8 to ~ 5 µg/cm3 for chlorophyll a, respectively. Soil water content decreased to below ~3% in the arid soils. Community fingerprinting-based principle component analyses revealed that bacterial communities formed distinct clusters specific to arid and wet soils; however, eukaryotic communities that clustered together did not have similar soil moisture content nor did they group together based on sampling location. Collectively, rRNA pyrosequencing indicated a considerably higher abundance of Cyanobacteria in wet soils and a higher abundance of Acidobacterial, Actinobacterial, Deinococcus/Thermus, Bacteroidetes, Firmicutes, Gemmatimonadetes, Nitrospira and Planctomycetes in arid soils. The two most significant differences at the genus level were Gillisia signatures present in arid soils and chloroplast signatures related to Streptophyta that were common in wet soils. Fungal dominance was observed in arid soils and Viridplantae were more common in wet soils. This research represents an in-depth characterization of microbial communities inhabiting wet DV soils. Results indicate that the repeated wetting of hyporheic zones has a profound impact on the bacterial and eukaryotic communities inhabiting in these areas.

  11. Wet storage integrity update

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, W.J.; Johnson, A.B. Jr.

    1983-09-01

    This report includes information from various studies performed under the Wet Storage Task of the Spent Fuel Integrity Project of the Commercial Spent Fuel Management (CSFM) Program at Pacific Northwest Laboratory. An overview of recent developments in the technology of wet storage of spent water reactor fuel is presented. Licensee Event Reports pertaining to spent fuel pools and the associated performance of spent fuel and storage components during wet storage are discussed. The current status of fuel that was examined under the CSFM Program is described. Assessments of the effect of boric acid in spent fuel pool water on the corrosion and stress corrosion cracking of stainless steel and the stress corrosion cracking of stainless steel piping containing stagnant water at spent fuel pools are discussed. A list of pertinent publications is included. 84 references, 21 figures, 11 tables.

  12. Wrinkling of wet paper

    Science.gov (United States)

    Kim, Ho-Young; Kim, Jungchul; Mahadevan, L.

    2011-11-01

    It is a mundane experience that paper stained with water wrinkles. It is because a wetted portion of paper, which swells due to the hygroexpansive nature of the cellulose fiber network, deforms out of its original plane. Here we quantify the dynamics of wrinkling of wet paper coupled to the capillary imbibition of water into paper using a combination of experiment and theory. While supplying water from a capillary tube that touches the center of a paper strip, we measure the spreading rate of the wet area, wait time for the out-of-plane buckling, and temporal growth of a wrinkling magnitude. Using a theoretical model assuming a linear increase of the strain and an exponential decay of the elastic modulus with the water concentration, we construct scaling laws to predict the simultaneous capillary imbibition and wrinkling rates. This work was supported by the Wyss Institute of Harvard University.

  13. Avian Point Transect Survey; Seward Peninsula, Alaska, 2012

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data product contains avian point-transect survey data and habitat data collected on the Seward Peninsula, Alaska, USA, during 21 May – 10 June 2012. We...

  14. The NRS Transect 5:2 (spring 1987)

    OpenAIRE

    1987-01-01

    IN THIS ISSUE OF TRANSECT - (feature article) Interactive Video Now Simulates James Reserve - New Reserve: Younger Lagoon Reserve - Opportunities - Oil Spill Follow-up - Granite Mountains Profile - Berkeley Citation

  15. Vegetative Transect Results : Clarence Cannon National Wildlife Refuge : 1980

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes the result of 27 vegetative transects conducted on 21 fields of the Clarence Cannon National Wildlife Refuge. The methods used to collect the...

  16. Likelihood-based inference for clustered line transect data

    DEFF Research Database (Denmark)

    Waagepetersen, Rasmus Plenge; Schweder, Tore

    The uncertainty in estimation of spatial animal density from line transect surveys depends on the degree of spatial clustering in the animal population. To quantify the clustering we model line transect data as independent thinnings of spatial shot-noise Cox processes. Likelihood-based inference...... in an example concerning minke whales in the North Atlantic. Our modelling and computational approach is flexible but demanding in terms of computing time....

  17. Wetting of real surfaces

    CERN Document Server

    Bormashenko, Edward Yu

    2013-01-01

    The problem of wetting and drop dynamics on various surfaces is very interesting from both the scientificas well as thepractical viewpoint, and subject of intense research.The results are scattered across papers in journals, sothis workwill meet the need for a unifying, comprehensive work.

  18. Wet Macular Degeneration

    Science.gov (United States)

    ... macular degeneration Overview By Mayo Clinic Staff Wet macular degeneration is a chronic eye disease that causes blurred vision or a blind spot in your visual field. It's generally caused by abnormal blood vessels that leak fluid or blood into ... macular degeneration is one of two types of age-related ...

  19. Potassium titanyl phosphate laser welding following complete nerve transection.

    Science.gov (United States)

    Bhatt, Neel K; Mejias, Christopher; Kallogjeri, Dorina; Gale, Derrick C; Park, Andrea M; Paniello, Randal C

    2017-07-01

    Cranial nerve transection during head and neck surgery is conventionally repaired by microsuture reanastomosis. Laser nerve welding (LNW), using CO2 laser to spot-weld the epineurium of transected nerve endings, has been shown in animal models to be a novel alternative to microsuture repair. This method avoids needle/suture material and minimizes instrumentation of the nerve. We hypothesized that potassium titanyl phosphate (KTP) laser would be superior to CO2 laser in repairing transected nerves. Using a rat posterior tibial nerve injury model, we compared CO2 laser, KTP laser, and microsuture reanastomosis. Animal study. Animals underwent unilateral posterior tibial nerve transection. The injury was repaired by microsuture repair (n = 15), CO2 laser repair (n = 15), or KTP laser repair (n = 15). Weekly walking tracks were performed to measure functional recovery. Nerve segments were harvested for axon counting. At 6 weeks, the KTP LNW had the best functional recovery (92.4 ± 8.6%) compared to microsuture repair (84.5 ± 10.2%, difference 7.9%, 95% confidence interval [CI]: 0.84%-14.96%). CO2 laser repair had a functional recovery of 86.8 ± 11.2%. KTP LNW had better axon recovery compared to transection/repair (difference 530.7 axons, 95% CI: 329.9-731.5). Operative time for the microsuture repair was 18.2 ± 6.8 minutes, compared to 5.8 ± 3.7 minutes for the LNW groups (difference 12.4 minutes, 95% CI: 8.6-16.2 minutes). KTP, CO2 , and microsuture repair all showed good functional recovery following complete transection of the posterior tibial nerve. Following complete nerve transection during head and neck surgery, KTP LNW may be a novel alternative to microsuture repair. NA Laryngoscope, 127:1525-1530, 2017. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

  20. WET SOLIDS FLOW ENHANCEMENT

    Energy Technology Data Exchange (ETDEWEB)

    Unknown

    2001-03-25

    The yield locus, tensile strength and fracture mechanisms of wet granular materials were studied. The yield locus of a wet material was shifted to the left of that of the dry specimen by a constant value equal to the compressive isostatic stress due to pendular bridges. for materials with straight yield loci, the shift was computed from the uniaxial tensile strength, either measured in a tensile strength tester or calculated from the correlation, and the angle of internal friction of the material. The predicted shift in the yield loci due to different moisture contents compare well with the measured shift in the yield loci of glass beads, crushed limestone, super D catalyst and Leslie coal. Measurement of the void fraction during the shear testing was critical to obtain the correct tensile strength theoretically or experimentally.

  1. Writing on wet paper

    Science.gov (United States)

    Fridrich, Jessica; Goljan, Miroslav; Lisonek, Petr; Soukal, David

    2005-03-01

    In this paper, we show that the communication channel known as writing in memory with defective cells is a relevant information-theoretical model for a specific case of passive warden steganography when the sender embeds a secret message into a subset C of the cover object X without sharing the selection channel C with the recipient. The set C could be arbitrary, determined by the sender from the cover object using a deterministic, pseudo-random, or a truly random process. We call this steganography "writing on wet paper" and realize it using low-density random linear codes with the encoding step based on the LT process. The importance of writing on wet paper for covert communication is discussed within the context of adaptive steganography and perturbed quantization steganography. Heuristic arguments supported by tests using blind steganalysis indicate that the wet paper steganography provides improved steganographic security for embedding in JPEG images and is less vulnerable to attacks when compared to existing methods with shared selection channels.

  2. Surgical management of transected injury to the pancreatic neck

    Institute of Scientific and Technical Information of China (English)

    母德清; 董庆华; 彭淑牖; 彭承宏; 吴育莲

    2003-01-01

    Objective: To present a batch of data of transected pancreatic neck injuries and to sum up the experience in surgical interventions for the injuries.Methods: We analysed 13 patients with a transected injury to the pancreatic neck from Jan. 1995 to Dec. 2000. External drainage was performed in all patients. Pancreatoduodenectomy was conducted in 2 patients with a transected injury to the pancreatic neck associated with duodenal ruptures, and TPN was administered immediately after operation. Proximal closure of the transected margin and distal pancreaticojejunostomy was performed in 4 patients. Proximal closure of the transected margin and distal pancreaticojejunostomy plus splenectomy was performed in 7 patients associated with contusion of pancreatic body or tail plus spleen rupture. Results: 12 patients healed and one patient died of anesthetic accident during the course of restoration of the dislocation of his right hip joint. Complications occurred in 7 patients.Conclusions: The operation should be performed according to the degree of the injuries and associated duodenal injuries. Routine drainage and nutrient support should be recommended.

  3. Isolated Pediatric Pancreatic Transection Secondary to Ocean-Related Trauma

    Directory of Open Access Journals (Sweden)

    Afif N Kulaylat

    2013-03-01

    Full Text Available Context Isolated pancreatic transection is a rare but well-recognized complication following blunt trauma of the abdomen. Diagnosis at presentation may be difficult and delayed due to subtle initial symptoms and evolving nature of the injury. Case report We describe an isolated complete pancreatic transection in a 14-year-old female secondary to a previously unreported and highly unusual mechanism (being tossed by a wave. Diagnosis was obtained by computed tomography scan 24 hours following initial trauma. She was managed operatively with an open distal pancreatectomy with splenic preservation and no subsequent complications. Conclusions The force sustained from the blunt abdominal trauma of being tossed by a wave can be significant. The management of pancreatic injuries in children, particularly in the context of ductal transection, is controversial. Timely recognition and management is critical to optimal outcomes. Early operative intervention may help to avoid complications such as abscess or pseudocyst formation.

  4. Precipitation chemistry and wet deposition in a remote wet savanna site in West Africa: Djougou (Benin)

    Science.gov (United States)

    Akpo, A. B.; Galy-Lacaux, C.; Laouali, D.; Delon, C.; Liousse, C.; Adon, M.; Gardrat, E.; Mariscal, A.; Darakpa, C.

    2015-08-01

    , biomass burning and biofuel combustions. The second highest contribution is the calcium ion (13.3 μeq·L-1), characteristic of dust aerosols from terrigenous sources, Calcium contributes up to 46% of the precipitation chemistry in Djougou. Finally, these results are compared to those obtained for other selected African sites representative of other main natural ecosystems: dry savanna and forest. The study of the African ecosystem transect indicates a pH gradient with more acidic pH in the forested ecosystem. Nitrogenous contribution to the chemical composition of rain in Lamto, wet savanna, (24%) is equivalent to the one estimated in Djougou (24%). The last contribution concerns organic acidity, which represents 7% of total ionic content of precipitation at Djougou. The relative particulate contribution PC and the relative gaseous contribution GC are calculated using the mean chemical composition measured in Djougou for the studied period. The comparison with other African sites gives 40% and 43% PC in wet savannas of Lamto (Côte d'Ivoire) and Djougou (Benin) respectively, 20% PC in the equatorial forest of Zoetele (Cameroon) and 80% PC in dry savanna of Banizoumbou (Niger). The results shown here indicate the existence of a North-South gradients of organic, marine, terrigenous and nitrogenous contributions along the transect in West and Central Africa.

  5. Likelihood-based inference for clustered line transect data

    DEFF Research Database (Denmark)

    Waagepetersen, Rasmus; Schweder, Tore

    2006-01-01

    The uncertainty in estimation of spatial animal density from line transect surveys depends on the degree of spatial clustering in the animal population. To quantify the clustering we model line transect data as independent thinnings of spatial shot-noise Cox processes. Likelihood-based inference...... is implemented using markov chain Monte Carlo (MCMC) methods to obtain efficient estimates of spatial clustering parameters. Uncertainty is addressed using parametric bootstrap or by consideration of posterior distributions in a Bayesian setting. Maximum likelihood estimation and Bayesian inference are compared...

  6. Phoenix's Wet Chemistry Lab

    Science.gov (United States)

    2008-01-01

    This is an illustration of the analytical procedure of NASA's Phoenix Mars Lander's Wet Chemistry Lab (WCL) on board the Microscopy, Electrochemistry, and Conductivity Analyzer (MECA) instrument. By dissolving small amounts of soil in water, WCL can determine the pH, the abundance of minerals such as magnesium and sodium cations or chloride, bromide and sulfate anions, as well as the conductivity and redox potential. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  7. Phoenix's Wet Chemistry Lab

    Science.gov (United States)

    2008-01-01

    This is an illustration of soil analysis on NASA's Phoenix Mars Lander's Wet Chemistry Lab (WCL) on board the Microscopy, Electrochemistry, and Conductivity Analyzer (MECA) instrument. By dissolving small amounts of soil in water, WCL will attempt to determine the pH, the abundance of minerals such as magnesium and sodium cations or chloride, bromide and sulfate anions, as well as the conductivity and redox potential. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  8. Wetting in Color

    Science.gov (United States)

    Burgess, Ian Bruce

    Colorimetric litmus tests such as pH paper have enjoyed wide commercial success due to their inexpensive production and exceptional ease of use. However, expansion of colorimetry to new sensing paradigms is challenging because macroscopic color changes are seldom coupled to arbitrary differences in the physical/chemical properties of a system. In this thesis I present in detail the development of Wetting in Color Technology, focusing primarily on its application as an inexpensive and highly selective colorimetric indicator for organic liquids. The technology exploits chemically-encoded inverse-opal photonic crystals to control the infiltration of fluids to liquid-specific spatial patterns, projecting minute differences in liquids' wettability to macroscopically distinct, easy-to-visualize structural color patterns. It is shown experimentally and corroborated with theoretical modeling using percolation theory that the high selectivity of wetting, upon-which the sensitivity of the indicator relies, is caused by the highly symmetric structure of our large-area, defect-free SiO2 inverse-opals. The regular structure also produces a bright iridescent color, which disappears when infiltrated with liquid - naturally coupling the optical and fluidic responses. Surface modification protocols are developed, requiring only silanization and selective oxidation, to facilitate the deterministic design of an indicator that differentiates a broad range of liquids. The resulting tunable, built-in horizontal and vertical chemistry gradients allow the wettability threshold to be tailored to specific liquids across a continuous range, and make the readout rely only on countable color differences. As wetting is a generic fluidic phenomenon, Wetting in Color technology could be suitable for applications in authentication or identification of unknown liquids across a broad range of industries. However, the generic nature of the response also ensures chemical non-specificity. It is shown

  9. Wet steam wetness measurement in a 10 MW steam turbine

    Directory of Open Access Journals (Sweden)

    Kolovratník Michal

    2014-03-01

    Full Text Available The aim of this paper is to introduce a new design of the extinction probes developed for wet steam wetness measurement in steam turbines. This new generation of small sized extinction probes was developed at CTU in Prague. A data processing technique is presented together with yielded examples of the wetness distribution along the last blade of a 10MW steam turbine. The experimental measurement was done in cooperation with Doosan Škoda Power s.r.o.

  10. Wet steam wetness measurement in a 10 MW steam turbine

    OpenAIRE

    Kolovratník Michal; Bartoš Ondřej

    2014-01-01

    The aim of this paper is to introduce a new design of the extinction probes developed for wet steam wetness measurement in steam turbines. This new generation of small sized extinction probes was developed at CTU in Prague. A data processing technique is presented together with yielded examples of the wetness distribution along the last blade of a 10MW steam turbine. The experimental measurement was done in cooperation with Doosan Škoda Power s.r.o.

  11. Edge effect on carabid assemblages along forest-grass transects

    Directory of Open Access Journals (Sweden)

    T. Magura

    2001-02-01

    Full Text Available During 1997 and 1998, we have tested the edge-effect for carabids along oak-hornbeam forest-grass transects using pitfall traps in Hungary. Our hypothesis was that the diversity of carabids will be higher in the forest edge than in the forest interior. We also focused on the characteristic species of the habitats along the transects and the relationships between their distribution and the biotic and abiotic factors.

    Our results proved that there was a significant edge effect on the studied carabid communities: the Shannon diversity increased significantly along the transects from the forest towards the grass. The diversity of the carabids were significantly higher in the forest edge and in the grass than in the forest interior. The carabids of the forest, the forest edge and the grass are separated from each other by principal coordinates analysis and by indicator species analysis (IndVal, suggesting that each of the three habitats has a distinct species assemblages. There were 5 distinctive groups of carabids: 1 habitat generalists, 2 forest generalists, 3 species of the open area, 4 forest edge species, and 5 forest specialists. It was demonstrated by multiple regression analyses, that the relative air moisture, temperature of the ground, the cover of leaf litter, herbs, shrubs and canopy cover, abundance of the carabids’ preys are the most important factors determining the diversity and spatial pattern of carabids along the studied transects.

  12. Spatio-temporal variations and influencing factors of polycyclic aromatic hydrocarbons in atmospheric bulk deposition along a plain-mountain transect in western China

    Science.gov (United States)

    Xing, Xinli; Zhang, Yuan; Yang, Dan; Zhang, Jiaquan; Chen, Wei; Wu, Chenxi; Liu, Hongxia; Qi, Shihua

    2016-08-01

    Ten atmospheric bulk deposition (the sum of wet and dry deposition) samplers for polycyclic aromatic hydrocarbons (PAHs) were deployed at a plain-mountain transect (namely PMT transect, from Daying to Qingping) in Chengdu Plain, West China from June 2007 to June 2008 in four consecutive seasons (about every three months). The bulk deposition fluxes of ∑15-PAHs ranged from 169.19 μg m-2 yr-1 to 978.58 μg m-2 yr-1 with geometric mean of 354.22 μg m-2 yr-1. The most prevalent PAHs were 4-ring (39.65%) and 3-ring (35.56%) PAHs. The flux values were comparable to those in rural areas. Higher fluxes of total PAHs were observed in the middle of PMT transect (SL, YX and JY, which were more urbanized than other sites). The seasonal deposition fluxes in the sampling profile indicated seasonality of the contaminant source was an important factor in controlling deposition fluxes. PAHs bulk deposition was negatively correlated with meteorological parameters (temperature, wind speed, humidity, and precipitation). No significant correlations between soil concentrations and atmospheric deposition were found along this transect. PAHs in soil samples had combined sources of coal, wood and petroleum combustion, while a simple source of coal, wood and grass combustion for bulk deposition. There were significant positive correlation relationship (p region of China or farther regions via long-range transport.

  13. Wet solids flow enhancemant

    Energy Technology Data Exchange (ETDEWEB)

    Caram, H.S.; Foster, N.; Wildman, D.J. [USDOE Pittsburgh Energy Technology Center, PA (United States)

    1996-12-31

    WE used glass beads of different sizes as.a model system to study the flow enhancing properties of Octadecyltrichlorosilane (OTS). 0TS provides Si(CH{sub 2}){sub 17}CH{sub 3} groups that bind with the surface hydrox groups to make it hydrophobic. Experimental data showed, indeed, that surface hydrophobicity promotes the flow of wet granular materials. Mixtures of different percentage of silanized/unsilanized particles were prepared for tensile strength measurements. The tensile strength decreased as more silanized particles were added to the samples. The relationship between dimensionless tensile strength and void fraction followed the correlation found by Pierrat (1994). Contact angles were larger for the silanized particles, as compared with unsilanized ones.

  14. Wetting and Minimal Surfaces

    CERN Document Server

    Bachas, C; Wiese, K J; Bachas, Constantin; Doussal, Pierre Le; Wiese, Kay Joerg

    2006-01-01

    We study minimal surfaces which arise in wetting and capillarity phenomena. Using conformal coordinates, we reduce the problem to a set of coupled boundary equations for the contact line of the fluid surface, and then derive simple diagrammatic rules to calculate the non-linear corrections to the Joanny-de Gennes energy. We argue that perturbation theory is quasi-local, i.e. that all geometric length scales of the fluid container decouple from the short-wavelength deformations of the contact line. This is illustrated by a calculation of the linearized interaction between contact lines on two opposite parallel walls. We present a simple algorithm to compute the minimal surface and its energy based on these ideas. We also point out the intriguing singularities that arise in the Legendre transformation from the pure Dirichlet to the mixed Dirichlet-Neumann problem.

  15. Wetting front instability in an initially wet unsaturated fracture

    Energy Technology Data Exchange (ETDEWEB)

    Nicholl, M.J.; Glass, R.J.; Nguyen, H.A.

    1992-12-31

    Experimental results exploring gravity-driven wetting front instability in a pre-wetted, rough-walled analog fracture are presented. Initial conditions considered include a uniform moisture field wetted to field capacity of the analog fracture and the structured moisture field created by unstable infiltration into an initially dry fracture. As in previous studies performed under dry initial conditions, instability was found to result both at the cessation of stable infiltration and at flux lower than the fracture capacity under gravitational driving force. Individual fingers were faster, narrower, longer, and more numerous than observed under dry initial conditions. Wetting fronts were found to follow existing wetted structure, providing a mechanism for rapid recharge and transport.

  16. Hydraulic gradient and dust emissivity along a playa to distal fan transect

    Science.gov (United States)

    Caldwell, T. G.; Sweeney, M.; Bacon, S. N.; McDonald, E.

    2009-12-01

    Distal alluvial fans along the margins of playas in the desert southwest, as well as the playas themselves, are subjected to severe temporal changes in groundwater levels. Soil moisture decreases with elevation above the playa floor where groundwater levels control both soil moisture and salinity. A series of measurements were conducted along transects of a wet playa (Soda Lake, California) and a dry playa (Silver Lake; California) to quantify changes in PM10) emissions, in addition to soil physical and chemical properties. The relatively high moisture content at the playa surface of Soda Lake is controlled by a perennial shallow ground water system that promotes the precipitation and wicking of evaporates and the formation of soluble salt crusts. In contrast, Silver Lake playa is underlain by a deep ground water system, therefore the playa surface remains dry throughout the year, except for unseasonably wet winters when flooding occurs of the playa surface during inundation events. Measurements were taken along linear transects across a diverse range of playa features ranging from the playa floor to distal fans using the Portable In-Situ Wind Erosion Lab (PI-SWERL), electromagnetic induction, and soil sampling. Results indicate that dust emissivity of undisturbed soils at a friction velocity (u*) of 0.56 m s-1 increases substantially at the playa fringe (3.53 ± 1.44 mg m-2 s-1) compared to the relatively higher distal alluvial fans (0.13 ± 0.08 mg m-2 s-1) and lower emission on the playa surfaces of either the silt crust of Silver Lake playa (fans. The area between these landforms, the silt-rich playa fringe, is subjected to transient groundwater and surface water influx resulting in monovalent bicarbonate (HCO3-) salts which disperse clays and creates an area of high emissivity. As distance to groundwater increases, the hydraulic gradient shifts from the upward evaporation of saline groundwater to downward flushing by dilute precipitation. This shift results in

  17. Breton Island Transects with Shoreline Change Rates (Pre-1950s) (Geographic, NAD83)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Breton Island, Louisiana Transects with Shoreline Change Rates (Pre-1950s) (Geographic, NAD83) consists of vector transect data that were derived from the Digital...

  18. Breton Island, Louisiana Transects with Shoreline Change Rates (1869 - 2014) (Geographic, NAD83)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Breton Island, Louisiana Transects with Shoreline Change Rates (1869 - 2014) (Geographic, NAD83) consists of vector transect data that were derived from the Digital...

  19. Breton Island Transects with Shoreline Change Rates (Pre/Post Hurricane Katrina) (Geographic, NAD83)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Breton Island, Louisiana Transects with Shoreline Change Rates (Pre/Post Hurricane Katrina) (Geographic, NAD83) consists of vector transect data that were derived...

  20. Breton Island, Louisiana Transects with Shoreline Change Rates (Post Hurricane Katrina) (Geographic, NAD83)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Breton Island, Louisiana Transects with Shoreline Change Rates (Post Hurricane Katrina) (Geographic, NAD83) consists of vector transect data that was derived from...

  1. Breton Island, Louisiana Transects with Shoreline Change Rates (Post-1950s) (Geographic, NAD83)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Breton Island, Louisiana Transects with Shoreline Change Rates (Post-1950s) (Geographic, NAD83) consists of vector transect data that were derived from the Digital...

  2. CRED REA Fish Team Belt Transect Survey at Kure Atoll, NW Hawaiian Islands, 2006

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 3 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 9 sites at Kure Atoll in the NW...

  3. CRED REA Fish Team Belt Transect Survey at Tutuila, American Samoa, 2006

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 3 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 22 sites at Tutuila in the...

  4. CRED REA Fish Team Belt Transect Survey at Rota, Marianas Archipelago, 2005

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 3 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 6 sites at Rota in the Marianas...

  5. CRED REA Fish Team Belt Transect Surveys at the Palmyra Atoll, 2004

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 3 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 10 sites at Palmyra Atoll in March...

  6. CRED REA Fish Team Belt Transect Surveys at Pearl and Hermes Reef, 2004

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 3 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 9 sites at Pearl Hermes Reef in...

  7. CRED REA Fish Team Belt Transect Surveys at Baker Island, 2004

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 3 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 6 sites at Baker Island in...

  8. CRED REA Fish Team Belt Transect Survey at Supply Reef, 2003

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 3 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 1 site at Supply Reef in the...

  9. Breton Island, Louisiana Transects with Shoreline Change Rates (1869 - 2014) (Geographic, NAD83)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Breton Island, Louisiana Transects with Shoreline Change Rates (1869 - 2014) (Geographic, NAD83) consists of vector transect data that were derived from the Digital...

  10. Breton Island Transects with Shoreline Change Rates (Pre/Post Hurricane Katrina) (Geographic, NAD83)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Breton Island, Louisiana Transects with Shoreline Change Rates (Pre/Post Hurricane Katrina) (Geographic, NAD83) consists of vector transect data that were derived...

  11. Breton Island Transects with Shoreline Change Rates (Pre-1950s) (Geographic, NAD83)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Breton Island, Louisiana Transects with Shoreline Change Rates (Pre-1950s) (Geographic, NAD83) consists of vector transect data that were derived from the Digital...

  12. Breton Island, Louisiana Transects with Shoreline Change Rates (Post-1950s) (Geographic, NAD83)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Breton Island, Louisiana Transects with Shoreline Change Rates (Post-1950s) (Geographic, NAD83) consists of vector transect data that were derived from the Digital...

  13. Breton Island, Louisiana Transects with Shoreline Change Rates (Post Hurricane Katrina) (Geographic, NAD83)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Breton Island, Louisiana Transects with Shoreline Change Rates (Post Hurricane Katrina) (Geographic, NAD83) consists of vector transect data that was derived from...

  14. CRED REA Fish Team Belt Transect Surveys at Hawaii Island, 2005

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 3 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 19 sites at Hawaii Island in...

  15. CRED REA Fish Team Belt Transect Surveys at Lisianski Island, 2004

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 3 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 9 sites at Lisianski in October,...

  16. CRED REA Fish Team Belt Transect Survey at Midway, NW Hawaiian Islands, 2006

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 3 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 9 sites at Midway in the NW...

  17. CRED REA Fish Team Belt Transect Survey at Guguan Island, 2003

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 3 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 3 sites at Guguan Island in the...

  18. CRED REA Fish Team Belt Transect Survey at Guam, Marianas Archipelago, 2007

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 3 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 10 sites at Guam in the Marianas...

  19. CRED REA Fish Team Belt Transect Survey at French Frigate Shoals, NW Hawaiian Islands, 2006

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 3 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 10 sites at French Frigate Shoals...

  20. CRED REA Fish Team Belt Transect Survey at Alamagan, Marianas Archipelago, 2005

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 3 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 3 sites at Alamagan in the...

  1. CRED REA Fish Team Belt Transect Surveys at Gardner Pinnacle, 2004

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 3 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 3 sites at Gardner Pinnacle in...

  2. CRED REA Fish Team Belt Transect Survey at Pathfinder Reef, Marianas Archipelago, 2005

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 3 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 2 sites at Pathfinder Reef in the...

  3. CRED REA Fish Team Belt Transect Survey at Agrihan, Marianas Archipelago, 2005

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 3 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 4 sites at Agrihan in the Marianas...

  4. CRED REA Fish Team Belt Transect Survey at Stingray Shoals, 2003

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 3 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 2 sites at Stingray Shoals in the...

  5. CRED REA Fish Team Belt Transect Survey at Santa Rosa Reef, 2003

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 3 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 2 sites at Santa Rosa Reef in the...

  6. CRED REA Fish Team Belt Transect Survey at Ta'u, 2004

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 3 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 9 sites at Ta'u Islands in...

  7. CRED REA Fish Team Belt Transect Survey at Ta'u, American Samoa, 2006

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 3 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 9 sites at Ta'u in the American...

  8. CRED REA Fish Team Belt Transect Survey at Lanai, Main Hawaiian Islands, 2006

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 3 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 6 sites at Lanai in the Main...

  9. CRED REA Fish Team Belt Transect Survey at Tinian Island, 2003

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 3 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 3 sites at Tinian in the...

  10. CRED REA Fish Team Belt Transect Survey at Ofu-Olosega, American Samoa, 2006

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 3 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 12 sites at Ofu-Olosega in the...

  11. CRED REA Fish Team Belt Transect Surveys at Laysan Island, 2002

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 3 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 3 sites at Laysan Island in...

  12. CRED REA Fish Team Belt Transect Survey at Alamagan Island, 2003

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 3 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 3 sites at Alamagan Island in the...

  13. CRED REA Fish Team Belt Transect Survey at Santa Rosa Bank, Marianas Archipelago, 2005

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 3 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 2 sites at Santa Rosa Bank in the...

  14. CRED REA Fish Team Belt Transect Surveys at Pearl and Hermes Reef, 2002

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 3 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 17 sites at Pearl Hermes Reef in...

  15. CRED REA Fish Team Belt Transect Surveys at French frigate Shoals, 2002

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 3 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 12 sites at French Frigate Shoals...

  16. CRED REA Fish Team Belt Transect Survey at Kauai, Main Hawaiian Islands, 2006

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 3 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 7 sites at Kauai in the Main...

  17. CRED REA Fish Team Belt Transect Survey at Wake Island, 2007

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 3 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 9 sites at Wake Island in the...

  18. CRED REA Fish Team Belt Transect Survey at Ofu/Olosega Islands, 2004

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 3 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 9 sites at Ofu and Olosega Islands...

  19. CRED REA Fish Team Belt Transect Survey at Wake, Pacific Remote Island Areas (PRIAs), 2005

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 3 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 14 sites at Wake in the Pacific...

  20. CRED REA Fish Team Belt Transect Survey at Pagan, Marianas Archipelago, 2007

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 3 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 9 sites at Pagan in the Marianas...

  1. CRED REA Fish Team Belt Transect Survey at Zealandia Bank, Marianas Archipelago, 2005

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 3 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 2 sites at Zealandia Bank in the...

  2. CRED REA Fish Team Belt Transect Surveys at the Midway Atoll, 2002

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 3 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 12 sites at Midway Atoll in...

  3. CRED REA Fish Team Belt Transect Survey at Sarigan, Marianas Archipelago, 2005

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 3 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 3 sites at Sarigan in the Marianas...

  4. CRED REA Fish Team Belt Transect Survey at Baker, Pacific Remote Island Areas, 2006

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 3 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 9 sites at Baker in the Pacific...

  5. CRED REA Fish Team Belt Transect Survey at Rota Island, 2003

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 3 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 6 sites at Rota in the...

  6. CRED REA Fish Team Belt Transect Survey at Maro Reef, NW Hawaiian Islands, 2006

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 3 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 9 sites at Maro Reef in the NW...

  7. CRED REA Fish Team Belt Transect Survey at Baker, Pacific Remote Island Areas in 2008

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Belt transects along 3 consecutively-placed, 25m transect lines were surveyed as part of Rapid Ecological Assessments conducted at 4 sites at Baker in the Pacific...

  8. Terrestrial transect study on driving mechanism of vegetation changes

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In terms of Chinese climate-vegetation model based on the classification of plant functional types, to- gether with climatic data from 1951 to 1980 and two future climatic scenarios (SRES-A2 and SRES-B2) in China from the highest and the lowest emission scenarios of greenhouse gases, the distribution patterns of vegetation types and their changes along the Northeast China Transect (NECT) and the North-South Transect of Eastern China (NSTEC) were simulated in order to understand the driving mechanisms of vegetation changes under climatic change. The results indicated that the vegetation distribution patterns would change significantly under future climate, and the major factors driving the vegetation changes were water and heat. However, the responses of various vegetation types to the changes in water and heat factors were obviously different. The vegetation changes were more sensi- tive to heat factors than to water factors. Thus, in the future climate warming will significantly affect vegetation distribution patterns.

  9. Distribution of small phytoflagellates along an Arctic fjord transect.

    Science.gov (United States)

    Piwosz, Kasia; Spich, Katarzyna; Całkiewicz, Joanna; Weydmann, Agata; Kubiszyn, Anna M; Wiktor, Józef M

    2015-07-01

    Phytoflagellates 75% of the depth-integrated abundance and biomass of total eukaryotes temperature and salinity positively correlated with the total abundance of phytoflagellates, chlorophytes, haptophytes, bolidophytes and pelagophytes. Cryptophytes, pedinellids and pavlovophytes were negatively associated with the nutrient concentrations. The community composition of phytoflagellates changed along the transect, which could have implications on food web dynamics and biogeochemical cycles between the open ocean environment and Kongsfjorden investigated here.

  10. Sleeve resection for delayed presentation of traumatic bronchial transection.

    LENUS (Irish Health Repository)

    Mohamed, H Y

    2010-02-01

    Tracheobronchial disruption is uncommon in blunt chest trauma. Many of these patients die before reaching the hospital. In the majority of survivors diagnosis is occasionally delayed resulting in complications like airway stenosis and lung collapse. Thus it is important to have radiological follow up after severe thoracic trauma. Sleeve resection can be an excellent option to conserve lung tissue in delayed presentation of bronchial transection.

  11. Traumatic transection of the optic chiasm: Magnetic resonance evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, R.; Goyal, M.; Sharma, A.; Dada, V.K.; Berry, M. [All India Institute of Medical Sciences, New Delhi (India). Departments of Radiodiagnosis and Ophthalmology

    1998-02-01

    Disruption of the optic chiasm is a rare complication of head trauma. Non-contrast Computed tomography of the head showed basi-frontal contusion but no evidence of haematoma. We present the findings on MRI of this entity in a 40-year-old patient presenting with bitemporal hemianopia. Complete chismal transection was confirmed on T1-weighted axial, coronal and sagittal images. Copyright (1998) Blackwell Science Pty Ltd 10 refs., 1 fig.

  12. Fetal fornix transection and gestation length in sheep.

    Science.gov (United States)

    McDonald, T J; Li, C; Vincent, S E; Nijland, M J

    2006-08-01

    Experiments in several species indicate that the hippocampus influences hypothalamo-pituitary-adrenal (HPA) axis function. In fetal sheep, simultaneous ACTH and cortisol rises over the last 30 days of gestation peak at term and are necessary for birth. We hypothesized that if the fetal hippocampal formation is functional in late gestation, loss of hippocampal input to the HPA axis following fetal fornix transection would change gestation length in comparison to controls. At 118-121 days of gestation (dG), stereotaxic technique was used in fetal sheep to sham transect (SHAM; n = 8) or transect (FXTX; n = 6) the dorsal fornix at the level of the hippocampal commissure. No differences were found between SHAM and FXTX fetuses in daily hormone profiles over the last week of gestation or in gestation length (148.0 +/- 1.2 vs. 149.0 +/- 0.4 dG, respectively). We conclude that the fetal hippocampus is immature in late gestation and we speculate that an immature hippocampus is necessary for the loss of negative feedback control that gives rise to the long term, simultaneous increases in ACTH and cortisol that are indispensable for labor and delivery at term in sheep.

  13. Sampling forest tree regeneration with a transect approach

    Directory of Open Access Journals (Sweden)

    D. Hessenmöller

    2013-05-01

    Full Text Available A new transect approach for sampling forest tree regeneration isdeveloped with the aim to minimize the amount of field measurements, and to produce an accurate estimation of tree species composition and density independent of tree height. This approach is based on the “probability proportional to size” (PPS theory to assess heterogeneous vegetation. This new method is compared with other approaches to assess forest regeneration based on simulated and measured, real data. The main result is that the transect approach requires about 50% of the time to assess stand density as compared to the plot approach, due to the fact that only 25% of the tree individuals are measured. In addition, tall members of the regeneration are counted with equal probability as small members. This is not the case in the plot approach. The evenness is 0.1 to 0.2 units larger in the transect by PPS than in the plot approach, which means that the plot approach shows a more homogeneous regeneration layer than the PPS approach, even though the stand densities and height distributions are similar. The species diversity is variable in both approaches and needs further investigations.

  14. Sampling forest tree regeneration with a transect approach

    Directory of Open Access Journals (Sweden)

    D. Hessenmoeller

    2013-07-01

    Full Text Available A new transect approach for sampling forest tree regeneration is developed with the aim to minimize the amount of field measurements, and to produce an accurate estimation of tree species composition and density independent of tree height. This approach is based on the “probability proportional to size” (PPS theory to assess heterogeneous vegetation. This new method is compared with other approaches to assess forest regeneration based on simulated and measured, real data. The main result is that the transect approach requires about 50% of the time to assess stand density as compared to the plot approach, due to the fact that only 25% of the tree individuals are measured. In addition, tall members of the regeneration are counted with equal probability as small members. This is not the case in the plot approach. The evenness is 0.1 to 0.2 units larger in the transect by PPS than in the plot approach, which means that the plot approach shows a more homogenous regeneration layer than the PPS approach, even though the stand densities and height distributions are similar. The species diversity is variable in both approaches and needs further investigations.

  15. Transect-based Three-Dimensional Road Modeling and Visualization

    Institute of Scientific and Technical Information of China (English)

    LI Qingquan; TANG Luliang; ZUO Xiaoqing; LI Hanwu

    2004-01-01

    On the basis of the study on road elements and the existing three-dimensional road data models, this paper puts forward the transect-based road modeling, resolves the modeling of the simplest road with two road transects, and fulfils the visualization of the road. OpenGL is applied as the tool of visualization. The map texture technology, LOD algorithm and dynamic multi-differentiating texture technology are of benefit to the construction of 3D road GIS, and improve the speed of roaming and effective visualization. This paper also disusses the combination of 2D digitall road map and 3D road scene, and the dynamic response between them. Finally, on the basis of the research on the transect-based road model, this paper develops the three-dimensional road geographic information system called virtual road ( VRoad ), which not only supplies road designers with a set of tool which can turn the designed 2D road data into 3D road and the high road assistant function area in computer, but also supplies the road management with a set of tool which can realize the road real time and interactive roaming, high-efficiency management.

  16. Electrical Resistivity Tomography in the characterisation of wetting patterns of historical masonry

    Science.gov (United States)

    López-González, Laura; Gomez-Heras, Miguel; Ortiz de Cosca, Raquel Otero; García-Morales, Soledad

    2016-04-01

    Electrical Resistivity Tomography (ERT) is a geophysical technique widely used to identify subsurface structures based on electrical resistivity measurements made at the surface. In recent years this technique has been used for surveying historic buildings and characterise the subsurface of walls by using non-invasive EKG electrodes. This methods is used to locate wet areas based on the lower electrical resistivity wet materials have in relation to dry ones. A good knowledge of the wetting patterns of historic buildings during, for example, rainfalls is crucial to understand the decay processes that take place in the building and plan interventions. This paper presents results of transects of Electric Resistivity Tomography of walls of the Monastery of Santa Maria de Mave (Palencia, Spain), a 9th century Romanesque building, during rainfall. ERT transects were performed with a GeoTom device (Geolog2000) in areas with and without buttresses to understand how this architectural detail affected the wetting dynamics of the building. The ERT results were integrated with other resistivity-based techniques and Thermohygrometric survey in a GIS and showed how lower resistivity surface measurements ERT correspond with areas of higher humidity. Resistivity-based techniques measured and evaporation focal points take in the interior of the building mark the outer ground level. The highest moisture content measurements do not always correspond to the visibly most damaged areas of the wall. The consecutive ERT transects show the wall getting wetter as rainfall progresses. The comparison of the measurements obtained of a wall affected by water obtained with GIS mapping, allowed to quickly studying the development of moisture in the wall over time, which is essential for a correct diagnosis of the building. Research funded by Madrid's Regional Government project Geomateriales 2 S2013/MIT-2914

  17. Train-borne Measurements of Enhanced Wet Season Methane Emissions in Northern Australia - Implications for Australian Tropical Wetland Emissions

    Science.gov (United States)

    Deutscher, N. M.; Griffith, D. W.; Paton-Walsh, C.

    2008-12-01

    We present the first transect measurements of CH4, CO2, CO and N2O taken on the Ghan railway travelling on a N-S transect of the Australian continent between Adelaide (34.9°S, 138.6°E) and Darwin (12.5°S, 130.9°E). The Ghan crosses Australia from the mainly agricultural mid-latitude south through the arid interior to the wet-dry tropical savannah south of and around Darwin. In the 2008 wet season (February) we observed a significant latitudinal gradient of CH4 increasing towards the north. The same pattern was observed in the late 2008 wet season (March-April), with a smaller latitudinal gradient. These will be compared with a dry season transect, to be undertaken in September/October 2008. The Air Pollution Model (TAPM), a regional scale prognostic meteorological model, is used to estimate the surface methane source strength required to explain the observed latitudinal gradient in CH4 in the wet season, and investigate the source type. Fluxes from cattle and termites together contribute up to 25% of the enhancements seen, leaving wetlands as the major source of wet season methane in the Australian tropics. Wetlands are the largest natural source of methane to the atmosphere, and tropical wetlands are responsible for the majority of the interannual variation in methane source strength. We attempt to quantify the annual methane flux contributed by anaerobic organic breakdown due to wet- season flooding in tropical Northern Territory.

  18. Polyethylene glycol restores axonal conduction after corpus callosum transection.

    Science.gov (United States)

    Bamba, Ravinder; Riley, D Colton; Boyer, Richard B; Pollins, Alonda C; Shack, R Bruce; Thayer, Wesley P

    2017-05-01

    Polyethylene glycol (PEG) has been shown to restore axonal continuity after peripheral nerve transection in animal models. We hypothesized that PEG can also restore axonal continuity in the central nervous system. In this current experiment, coronal sectioning of the brains of Sprague-Dawley rats was performed after animal sacrifice. 3Brain high-resolution microelectrode arrays (MEA) were used to measure mean firing rate (MFR) and peak amplitude across the corpus callosum of the ex-vivo brain slices. The corpus callosum was subsequently transected and repeated measurements were performed. The cut ends of the corpus callosum were still apposite at this time. A PEG solution was applied to the injury site and repeated measurements were performed. MEA measurements showed that PEG was capable of restoring electrophysiology signaling after transection of central nerves. Before injury, the average MFRs at the ipsilateral, midline, and contralateral corpus callosum were 0.76, 0.66, and 0.65 spikes/second, respectively, and the average peak amplitudes were 69.79, 58.68, and 49.60 μV, respectively. After injury, the average MFRs were 0.71, 0.14, and 0.25 spikes/second, respectively and peak amplitudes were 52.11, 8.98, and 16.09 μV, respectively. After application of PEG, there were spikes in MFR and peak amplitude at the injury site and contralaterally. The average MFRs were 0.75, 0.55, and 0.47 spikes/second at the ipsilateral, midline, and contralateral corpus callosum, respectively and peak amplitudes were 59.44, 45.33, 40.02 μV, respectively. There were statistically differences in the average MFRs and peak amplitudes between the midline and non-midline corpus callosum groups (P < 0.01, P < 0.05). These findings suggest that PEG restores axonal conduction between severed central nerves, potentially representing axonal fusion.

  19. Polyethylene glycol restores axonal conduction after corpus callosum transection

    Directory of Open Access Journals (Sweden)

    Ravinder Bamba

    2017-01-01

    Full Text Available Polyethylene glycol (PEG has been shown to restore axonal continuity after peripheral nerve transection in animal models. We hypothesized that PEG can also restore axonal continuity in the central nervous system. In this current experiment, coronal sectioning of the brains of Sprague-Dawley rats was performed after animal sacrifice. 3Brain high-resolution microelectrode arrays (MEA were used to measure mean firing rate (MFR and peak amplitude across the corpus callosum of the ex-vivo brain slices. The corpus callosum was subsequently transected and repeated measurements were performed. The cut ends of the corpus callosum were still apposite at this time. A PEG solution was applied to the injury site and repeated measurements were performed. MEA measurements showed that PEG was capable of restoring electrophysiology signaling after transection of central nerves. Before injury, the average MFRs at the ipsilateral, midline, and contralateral corpus callosum were 0.76, 0.66, and 0.65 spikes/second, respectively, and the average peak amplitudes were 69.79, 58.68, and 49.60 μV, respectively. After injury, the average MFRs were 0.71, 0.14, and 0.25 spikes/second, respectively and peak amplitudes were 52.11, 8.98, and 16.09 μV, respectively. After application of PEG, there were spikes in MFR and peak amplitude at the injury site and contralaterally. The average MFRs were 0.75, 0.55, and 0.47 spikes/second at the ipsilateral, midline, and contralateral corpus callosum, respectively and peak amplitudes were 59.44, 45.33, 40.02 μV, respectively. There were statistically differences in the average MFRs and peak amplitudes between the midline and non-midline corpus callosum groups (P < 0.01, P < 0.05. These findings suggest that PEG restores axonal conduction between severed central nerves, potentially representing axonal fusion.

  20. SETAC-U.S. EPA WET INITIATIVES: ALL WET AND NOTHING BUT WET

    Science.gov (United States)

    To ensure that sould scientific principles and sound science are applied to the challenging issues in t he Whole Effluent Toxicity (WET) process, the Society of Environmental Toxicology and Chemistry (SETAC) Foundation for Environmental Education was awarded a cooperative agreem...

  1. SETAC-U.S. EPA WET INITIATIVES: ALL WET AND NOTHING BUT WET

    Science.gov (United States)

    To ensure that sould scientific principles and sound science are applied to the challenging issues in t he Whole Effluent Toxicity (WET) process, the Society of Environmental Toxicology and Chemistry (SETAC) Foundation for Environmental Education was awarded a cooperative agreem...

  2. Application of Golden Section Method to Channel Transect Design

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    During the desing of channel transect,the paper brings forward golden section method,which is 0. 618methods. In order to reduce the calculation volume of the natural depth of water ho and bottom-width b which apply trial calculation method and gralphic method ,and improve the calculate precision ,the mathematical model has been built up,the writer combines example to explain the train of thought ,the result shows that the calculation precision is high, the correctness is tested and verified by the result which is calculated by hand. It can be referred tO the hydroelectric works.

  3. Postoperative Airway Emergency following Accidental Flexometallic Tube Transection

    Directory of Open Access Journals (Sweden)

    Karim Habib MR

    2015-10-01

    Full Text Available Endotracheal intubation using flexometallic tubes are often required in anaesthesia practice for a variety of reasons. It is preferred in the head and neck region surgeries due to its relative resistance to kinking forces. At times, these patients postoperatively may need to be shifted to ICU or HDU without extubation for further stabilization/management and extubation after adequate recovery. We present an unusual accident where a new flexometallic endotracheal tube was permanently tapered, transected and migrated proximally due to patient’s bite on tube leading to airway emergency in post-operative recovery period.

  4. Magnetic resonance imaging of traumatic transection of the optic chiasm

    Energy Technology Data Exchange (ETDEWEB)

    De Nunzio, M.; McAuliffe, W.; Chakera, T.M.H. [Royal Perth Hospital, Perth, WA (Australia). Department of Diagnostic Radiology

    1997-05-01

    Traumatic lesions of the visual pathways are an uncommon, but well recognized complication of head injury. Optimal visualization of such lesions is probably best achieved using multiplanar magnetic resonance (MR) imaging. A case of complete sagittal transection of the optic chiasm using MR imaging is reported. This has been rarely documented in the literature. Computerized tomography demonstrated a basal skull fracture extending through the sphenoid sinus and into the floor of the pituitary fossa. However, MRI is advocated as the optimal imaging modality for the diagnosis of traumatic lesions of suprasellar structures, perhaps obviating the need for future investigations. 7 refs., 1 fig.

  5. Bilateral Traumatic Globe Luxation with Optic Nerve Transection

    Directory of Open Access Journals (Sweden)

    Levent Tok

    2014-12-01

    Full Text Available Purpose: The purpose of this study was to document clinical findings and management of a patient with bilateral globe luxation and optic nerve transection. Materials and Methods: A 25-year-old female patient was admitted to the emergency department with bilateral traumatic globe luxation following a motor vehicle accident. Results: Visual acuity testing showed no light perception. The right pupil was dilated and bilaterally did not react to light. The globes were bilaterally intact. A computed tomography scan revealed Le Fort type II fractures, bilateral optic nerve transection and disruption of all extraocular muscles. The globes of the patient were bilaterally reduced into the orbit. However, the patient developed phthisis bulbi in the right eye at month 3. Conclusion: Globe luxation presents a dramatic clinical picture, and may lead to the development of severe complications due to the concomitance of complete optic nerve dissection and multiple traumas. Even if the luxated globe is repositioned into the orbit, there is still an increased risk of the development of phthisis due to ischemia.

  6. Terrestrial transect study on driving mechanism of vegetation changes

    Institute of Scientific and Technical Information of China (English)

    ZHANG YuJin; ZHOU GuangSheng

    2008-01-01

    In terms of Chinese climate-vegetation model based on the classification of plant functional types,together with climatic data from 1951 to 1980 and two future climatic scenarios (SRES-A2 and SRES-B2)in China from the highest and the lowest emission scenarios of greenhouse gases,the distribution patterns of vegetation types and their changes along the Northeast China Transect (NECT) and the North-South Transect of Eastern China (NSTEC) were simulated in order to understand the driving mechanisms of vegetation changes under climatic change. The results indicated that the vegetation distribution patterns would change significantly under future climate,and the major factors driving the vegetation changes were water and heat. However,the responses of various vegetation types to the changes in water and heat factors were obviously different. The vegetation changes were more sensitive to heat factors than to water factors. Thus,in the future climate warming will significantly affect vegetation distribution patterns.

  7. Squeezing wetting and nonwetting liquids.

    Science.gov (United States)

    Samoilov, V N; Persson, B N J

    2004-01-22

    We present molecular-dynamics results for the squeezing of octane (C8H18) between two approaching solid elastic walls with different wetting properties. The interaction energy between the octane bead units and the solid walls is varied from a very small value (1 meV), corresponding to a nonwetting surface with a very large contact angle (nearly 180 degrees), to a high value (18.6 meV) corresponding to complete wetting. When at least one of the solid walls is wetted by octane we observe well defined molecular layers develop in the lubricant film when the thickness of the film is of the order of a few atomic diameters. An external squeezing-pressure induces discontinuous, thermally activated changes in the number n of lubricant layers (n-->n-1 layering transitions). With increasing interaction energy between the octane bead units and the solid walls, the transitions from n to n-1 layers occur at higher average pressure. This results from the increasing activation barrier to nucleate the squeeze-out with increasing lubricant-wall binding energy (per unit surface area) in the contact zone. Thus, strongly wetting lubricant fluids are better boundary lubricants than the less wetting ones, and this should result in less wear. We analyze in detail the effect of capillary bridge formation (in the wetting case) and droplets formation (in the nonwetting case) on the forces exerted by the lubricant on the walls. For the latter case small liquid droplets may be trapped at the interface, resulting in a repulsive force between the walls during squeezing, until the solid walls come into direct contact, where the wall-wall interaction may be initially attractive. This effect is made use of in some practical applications, and we give one illustration involving conditioners for hair care application.

  8. Wet flue gas desulfurization processes

    Directory of Open Access Journals (Sweden)

    Hayrunnisa Çavuşoğlu

    2013-04-01

    Full Text Available The wet flue gas desulfurization process is widely used for the treatment of exhaust gases in power stations. Due to its high level of effectiveness over the already available processes, it has also been the mostly preferred method by industry. Its high SO2 removal efficiency, wide applicability of absorption chemicals and the ease of the chemical process handling which does not require comprehensive konowledge are among the main advantages of this process. In this article, various wet flue gas desulfurization processes such as lime/limestone have beendiscussed.

  9. Contribution of water-limited regions to their own supply of rainfall during wet and dry years

    Science.gov (United States)

    Miralles, Diego; Nieto, Raquel; McDowell, Nathan; Dorigo, Wouter; Verhoest, Niko; Liu, Yi; Teuling, Adriaan; Dolman, Han; Good, Stephen; Gimeno, Luis

    2017-04-01

    The occurrence of wet and dry spells in water-limited regions remains poorly understood. When these precipitation anomalies happen during the growing season, they can impact carbon and water budgets and hinder the regional management of natural resources. The difficulties to understand and predict these anomalies are partly owed to the complex role that water-limited ecoregions play in the genesis of their own rainfall: the increases in biomass and transpiration during the growing season are expected to influence the local input of rainfall. In this presentation, we unravel the origin and immediate drivers of growing-season rainfall in the ten major water-limited ecoregions on Earth. We use novel satellite data of vegetation water content and transpiration, combined with Langrangian atmospheric trajectory modelling. The extent to which these ecoregions themselves contribute to their own supply of rainfall is analyzed for dry and wet years separately. Results show that persistent anomalies in growing-season precipitation—and subsequent biomass impacts—are caused by a complex interplay of anomalies in land and ocean evaporation, air circulation and local atmospheric stability. Nonetheless, the specific drivers vary depending on the region of interest. For instance, in Kalahari and Australia, local atmospheric instability and evaporation in the surrounding regions play a central role. In these regions, the volumes of moisture recycling decline in dry years, providing an overall positive feedback that intensifies dry conditions. Despite these declines in the volumes of recycled rainfall, recycling ratios increase over 40% during dry times. This implies that transpiration in periods of water stress partly offsets the decreases in incoming precipitation that are mainly triggered by external conditions. Findings highlight the need to adequately represent vegetation-atmosphere feedbacks in models to predict biomass changes and simulate the fate of water-limited regions

  10. 4. The transectional structure of society: the basic societal functions.

    Science.gov (United States)

    2014-05-01

    For the purposes of research and/or evaluation, a society is organised into 13 basic societal functions (BSFs) within an overall Coordination and Control system. This organisation facilitates transectional descriptions of society or a component of a society for assessment at any given time across the longitudinal phases of a disaster. An assessment results in a picture or description of function(s) limited to the point in time of the assessment. Together with simultaneous assessments of the functional status of all, some, or one of the other BSFs, such assessments deliver a transectional picture of the situation of a society. Since no function operates in isolation from the other functions, information of the concomitant status of several BSFs is crucial to gain a better understanding of functional losses and of the effects and side effects of an intervention. The 13 BSFs include: (1) Public Health (dominantly preventive); (2) Medical Care (dominantly curative); (3) Water and Sanitation; (4) Shelter and Clothing; (5) Food and Nutrition; (6) Energy Supplies; (7) Public Works and Engineering; (8) Social Structure; (9) Logistics And Transportation; (10) Security; (11) Communications; (12); Economy; and (13) Education. These BSFs relate with each other through the Coordination and Control function. Many functions of the BSFs and their respective subfunctions and elements overlap (they share some common subfunctions and elements). However, for the purposes of research/evaluation, it is necessary to assign subfunctions and elements to only one of the BSFs. Just as in the practice of clinical medicine, the sum of assessments provides the transectional description of the status of each of these BSFs at a given time. From this information, compared to the pre-event description of the society, interventions are selected that are likely to meet the defined objectives and their overarching goal(s), and respective plans are developed and implemented. The effects of each

  11. Inhibiting Wet Oxidation of Ammonia

    Science.gov (United States)

    Onisko, D. B. L.

    1985-01-01

    Simple modification of wet-oxidation process for treating organicwaste reduces loss of fixed nitrogen, potentially valuable byproduct of process. Addition of sufficient sulfuric acid to maintain reaction pH below 3 greatly reduces oxidation of ammonia to free nitrogen. No equipment modification required.

  12. Wedge wetting by electrolyte solutions

    Science.gov (United States)

    Mußotter, Maximilian; Bier, Markus

    2017-09-01

    The wetting of a charged wedgelike wall by an electrolyte solution is investigated by means of classical density functional theory. As in other studies on wedge wetting, this geometry is considered as the most simple deviation from a planar substrate, and it serves as a first step toward more complex confinements of fluids. By focusing on fluids containing ions and surface charges, features of real systems are covered that are not accessible within the vast majority of previous theoretical studies concentrating on simple fluids in contact with uncharged wedges. In particular, the filling transition of charged wedges is necessarily of first order, because wetting transitions of charged substrates are of first order and the barrier in the effective interface potential persists below the wetting transition of a planar wall; hence, critical filling transitions are not expected to occur for ionic systems. The dependence of the critical opening angle on the surface charge, as well as the dependence of the filling height, of the wedge adsorption, and of the line tension on the opening angle and on the surface charge are analyzed in detail.

  13. Perforant path transection induces complement C9 deposition in hippocampus.

    Science.gov (United States)

    Johnson, S a; Young-Chan, C S; Laping, N J; Finch, C E

    1996-04-01

    The presence of complement system proteins in amyloid plaques and the up-regulation of several complement mRNAs in neurons and glial cells in affected brain regions during Alzheimer disease (AD) provided a basis for further examination of complement protein expression in a rodent lesion model of AD. Perforant path transection in rats was used as a model for the degeneration of entorhinal cortex (EC) layer II neurons and the consequent deafferentation of the hippocampus that occurs during AD. Immunostaining for C9, a key terminal component of the complement cascade membrane attack complex (MAC), showed extracellular C9 deposition in parenchyma around the EC wound and in hippocampus as early as 1 day, and disappeared by 14 days postlesion. Apoptosis of EC layer II neurons was seen and was presumably due to severing of their axonal projections to the hippocampus by the transection lesion. However, apoptotic EC layer II neurons were not immunostained by anti-rat C9 antibody, suggesting complement was not involved in inducing apoptosis. In the deafferented hippocampus, extracellular C9 immunostaining was localized to the dentate gyrus middle molecular layer, a region of synaptic loss, dendritic degeneration, and early synaptogenesis. In addition, intracellular C9 immunostaining was seen only in select hippocampal interneurons. Dentate gyrus granule neurons and pyramidal neurons were not C9 immunostained. Clusterin (SGP-2), a soluble inhibitor of the MAC that is up-regulated in AD, was also detected in the wound area (extracellular), the dentate gyrus middle molecular layer (extracellular), and intracellularly in scattered hippocampal interneurons. The data support the hypothesis that the complement system generally participates in responses to brain injury, as well as in AD.

  14. Muscle differentiation after sciatic nerve transection and reinnervation in adult rats

    NARCIS (Netherlands)

    Ijkema-Paassen, J; Meek, MF; Gramsbergen, A

    Reinnervation after peripheral nerve transections generally leads to poor functional recovery. In order to study whether changes in muscles might be a contributing factor in this phenomenon we studied muscle morphology and fibre type distributions after sciatic nerve transection in the rat hind

  15. Demonstration of Pelvic Anatomy by Modified Midline Transection that Maintains Intact Internal Pelvic Organs

    Science.gov (United States)

    Steinke, Hanno; Saito, Toshiyuki; Herrmann, Gudrun; Miyaki, Takayoshi; Hammer, Niels; Sandrock, Mara; Itoh, Masahiro; Spanel-Borowski, Katharina

    2010-01-01

    Gross dissection for demonstrating anatomy of the human pelvis has traditionally involved one of two approaches, each with advantages and disadvantages. Classic hemisection in the median plane through the pelvic ring transects the visceral organs but maintains two symmetric pelvic halves. An alternative paramedial transection compromises one side…

  16. Composition and diversity of tree species in transects of location lowland evergreen forest of Ecuador

    Directory of Open Access Journals (Sweden)

    Jorge Caranqui A.

    2015-09-01

    Full Text Available The study was conducted in 9 transects 1000m2 of lowland evergreen forest, located in two locations on the coast and one in eastern Ecuador. It was to contribute to knowledge of the diversity and composition of woody plants over 10 cm diameter at breast height (DBH plus infer the state of conservation of forests based on the composition, the number of species, indices diversity and importance value (IV, found in 9 transects of 1000 m² of forest: 156 species, 107 genera and 39 families distributed in 9 transects, in each one the Simpson diversity index is of 0.92 to 0.95, in this case are diversity because all approaches 1. Most were found species aren´t present in all transects, the index value in each transect does not exceed 40%. Grouping transects match three locations exception made to transect 5 and 8 were conducted in disturbed sites, the most transects are intermediate disturbance that their high levels of diversity.

  17. Wetting hysteresis induced by nanodefects.

    Science.gov (United States)

    Giacomello, Alberto; Schimmele, Lothar; Dietrich, Siegfried

    2016-01-19

    Wetting of actual surfaces involves diverse hysteretic phenomena stemming from ever-present imperfections. Here, we clarify the origin of wetting hysteresis for a liquid front advancing or receding across an isolated defect of nanometric size. Various kinds of chemical and topographical nanodefects, which represent salient features of actual heterogeneous surfaces, are investigated. The most probable wetting path across surface heterogeneities is identified by combining, within an innovative approach, microscopic classical density functional theory and the string method devised for the study of rare events. The computed rugged free-energy landscape demonstrates that hysteresis emerges as a consequence of metastable pinning of the liquid front at the defects; the barriers for thermally activated defect crossing, the pinning force, and hysteresis are quantified and related to the geometry and chemistry of the defects allowing for the occurrence of nanoscopic effects. The main result of our calculations is that even weak nanoscale defects, which are difficult to characterize in generic microfluidic experiments, can be the source of a plethora of hysteretical phenomena, including the pinning of nanobubbles.

  18. Wetting of flexible fibre arrays.

    Science.gov (United States)

    Duprat, C; Protière, S; Beebe, A Y; Stone, H A

    2012-02-23

    Fibrous media are functional and versatile materials, as demonstrated by their ubiquity both in natural systems such as feathers and adhesive pads and in engineered systems from nanotextured surfaces to textile products, where they offer benefits in filtration, insulation, wetting and colouring. The elasticity and high aspect ratios of the fibres allow deformation under capillary forces, which cause mechanical damage, matting self-assembly or colour changes, with many industrial and ecological consequences. Attempts to understand these systems have mostly focused on the wetting of rigid fibres or on elastocapillary effects in planar geometries and on a fibre brush withdrawn from an infinite bath. Here we consider the frequently encountered case of a liquid drop deposited on a flexible fibre array and show that flexibility, fibre geometry and drop volume are the crucial parameters that are necessary to understand the various observations referred to above. We identify the conditions required for a drop to remain compact with minimal spreading or to cause a pair of elastic fibres to coalesce. We find that there is a critical volume of liquid, and, hence, a critical drop size, above which this coalescence does not occur. We also identify a drop size that maximizes liquid capture. For both wetting and deformation of the substrates, we present rules that are deduced from the geometric and material properties of the fibres and the volume of the drop. These ideas are applicable to a wide range of fibrous materials, as we illustrate with examples for feathers, beetle tarsi, sprays and microfabricated systems.

  19. Wet water glass production plant

    Directory of Open Access Journals (Sweden)

    Stanković Mirjana S.

    2003-01-01

    Full Text Available The IGPC Engineering Department designed basic projects for a wet hydrate dissolution plant, using technology developed in the IGPC laboratories. Several projects were completed: technological, machine, electrical, automation. On the basis of these projects, a production plant of a capacity of 75,000 t/y was manufactured, at "Zeolite Mira", Mira (VE, Italy, in 1997. and 1998, increasing detergent zeolite production, from 50,000 to 100,000 t/y. Several goals were realized by designing a wet hydrate dissolution plant. The main goal was increasing the detergent zeolite production. The technological cycle of NaOH was closed, and no effluents emitted, and there is no pollution (except for the filter cake. The wet water glass production process is fully automatized, and the product has uniform quality. The production process can be controlled manually, which is necessary during start - up, and repairs. By installing additional process equipment (centrifugal pumps and heat exchangers technological bottlenecks were overcome, and by adjusting the operation of autoclaves, and water glass filters and also by optimizing the capacities of process equipment.

  20. European wet deposition maps based on measurements

    NARCIS (Netherlands)

    Leeuwen EP van; Erisman JW; Draaijers GPJ; Potma CJM; Pul WAJ van; LLO

    1995-01-01

    To date, wet deposition maps on a European scale have been based on long-range transport model results. For most components wet deposition maps based on measurements are only available on national scales. Wet deposition maps of acidifying components and base cations based on measurements are needed

  1. European wet deposition maps based on measurements

    NARCIS (Netherlands)

    Leeuwen EP van; Erisman JW; Draaijers GPJ; Potma CJM; Pul WAJ van; LLO

    1995-01-01

    To date, wet deposition maps on a European scale have been based on long-range transport model results. For most components wet deposition maps based on measurements are only available on national scales. Wet deposition maps of acidifying components and base cations based on measurements are needed

  2. 49 CFR 173.159 - Batteries, wet.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Batteries, wet. 173.159 Section 173.159... Batteries, wet. (a) Electric storage batteries, containing electrolyte acid or alkaline corrosive battery fluid (wet batteries), may not be packed with other materials except as provided in paragraphs (g)...

  3. Leaf waxes in litter and topsoils along a European transect

    Science.gov (United States)

    Schäfer, Imke K.; Lanny, Verena; Franke, Jörg; Eglinton, Timothy I.; Zech, Michael; Vysloužilová, Barbora; Zech, Roland

    2016-10-01

    Lipid biomarkers are increasingly used to reconstruct past environmental and climate conditions. Leaf-wax-derived long-chain n-alkanes and n-alkanoic acids may have great potential for reconstructing past changes in vegetation, but the factors that affect the leaf wax distribution in fresh plant material, as well as in soils and sediments, are not yet fully understood and need further research. We systematically investigated the influence of vegetation and soil depth on leaf waxes in litter and topsoils along a European transect. The deciduous forest sites are often dominated by the n-C27 alkane and n-C28 alkanoic acid. Conifers produce few n-alkanes but show high abundances of the C24 n-alkanoic acid. Grasslands are characterized by relatively high amounts of C31 and C33 n-alkanes and C32 and C34 n-alkanoic acids. Chain length ratios thus may allow for distinguishing between different vegetation types, but caution must be exercised given the large species-specific variability in chain length patterns. An updated endmember model with the new n-alkane ratio (n-C31 + n-C33) / (n-C27 + n-C31 + n-C33) is provided to illustrate, and tentatively account for, degradation effects on n-alkanes.

  4. A population genetic transect of Panicum hallii (Poaceae).

    Science.gov (United States)

    Lowry, David B; Purmal, Colin T; Juenger, Thomas E

    2013-03-01

    Understanding the relationship between climate, adaptation, and population structure is of fundamental importance to botanists because these factors are crucial for the evolution of biodiversity and the response of species to future climate change. Panicum hallii is an emerging model system for perennial grass and bioenergy research, yet very little is known about the relationship between climate and population structure in this system. • We analyzed geographic population differentiation across 39 populations of P. hallii along a longitudinal transect from the savannas of central Texas through the deserts of Arizona and New Mexico. A combination of morphological and genetic (microsatellite) analysis was used to explore patterns of population structure. • We found strong differentiation between high elevation western desert populations and lower elevation eastern populations of P. hallii, with a pronounced break in structure occurring in western Texas. In addition, we confirmed that there are high levels of morphological and genetic structure between previous recognized varieties (var. hallii and var. filipes) within this species. • The results of this study suggest that patterns of population structure within P. hallii may be driven by climatic variation over space. Overall, this study lays the groundwork for future studies on the genetics of local adaptation and reproductive isolation in this system.

  5. Shrinkage of ipsilateral taste buds and hyperplasia of contralateral taste buds following chorda tympani nerve transection

    Directory of Open Access Journals (Sweden)

    Yi-ke Li

    2015-01-01

    Full Text Available The morphological changes that occur in the taste buds after denervation are not well understood in rats, especially in the contralateral tongue epithelium. In this study, we investigated the time course of morphological changes in the taste buds following unilateral nerve transection. The role of the trigeminal component of the lingual nerve in maintaining the structural integrity of the taste buds was also examined. Twenty-four Sprague-Dawley rats were randomly divided into three groups: control, unilateral chorda tympani nerve transection and unilateral chorda tympani nerve transection + lingual nerve transection. Rats were allowed up to 42 days of recovery before being euthanized. The taste buds were visualized using a cytokeratin 8 antibody. Taste bud counts, volumes and taste receptor cell numbers were quantified and compared among groups. No significant difference was detected between the chorda tympani nerve transection and chorda tympani nerve transection + lingual nerve transection groups. Taste bud counts, volumes and taste receptor cell numbers on the ipsilateral side all decreased significantly compared with control. On the contralateral side, the number of taste buds remained unchanged over time, but they were larger, and taste receptor cells were more numerous postoperatively. There was no evidence for a role of the trigeminal branch of the lingual nerve in maintaining the structural integrity of the anterior taste buds.

  6. Shrinkage of ipsilateral taste buds and hyperplasia of contralateral taste buds following chorda tympani nerve transection

    Institute of Scientific and Technical Information of China (English)

    Yi-ke Li; Juan-mei Yang; Yi-bo Huang; Dong-dong Ren; Fang-lu Chi

    2015-01-01

    The morphological changes that occur in the taste buds after denervation are not well under-stood in rats, especially in the contralateral tongue epithelium. In this study, we investigated the time course of morphological changes in the taste buds following unilateral nerve transection. The role of the trigeminal component of the lingual nerve in maintaining the structural integrity of the taste buds was also examined. Twenty-four Sprague-Dawley rats were randomly divided into three groups:control, unilateral chorda tympani nerve transection and unilateral chorda tympani nerve transection+lingual nerve transection. Rats were allowed up to 42 days of re-covery before being euthanized. The taste buds were visualized using a cytokeratin 8 antibody. Taste bud counts, volumes and taste receptor cell numbers were quantiifed and compared among groups. No signiifcant difference was detected between the chorda tympani nerve transection and chorda tympani nerve transection+lingual nerve transection groups. Taste bud counts, vol-umes and taste receptor cell numbers on the ipsilateral side all decreased signiifcantly compared with control. On the contralateral side, the number of taste buds remained unchanged over time, but they were larger, and taste receptor cells were more numerous postoperatively. There was no evidence for a role of the trigeminal branch of the lingual nerve in maintaining the structural integrity of the anterior taste buds.

  7. Spatial patterns of preconsolidation pressure and soil moisture along transects in two directions under coffee

    Directory of Open Access Journals (Sweden)

    Ivoney Gontijo

    2011-08-01

    Full Text Available Information on the spatial structure of soil physical and structural properties is needed to evaluate the soil quality. The purpose of this study was to investigate the spatial behavior of preconsolidation pressure and soil moisture in six transects, three selected along and three across coffee rows, at three different sites under different tillage management systems. The study was carried out on a farm, in Patrocinio, state of Minas Gerais, in the Southeast of Brazil (18 º 59 ' 15 '' S; 46 º 56 ' 47 '' W; 934 m asl. The soil type is a typic dystrophic Red Latosol (Acrustox and consists of 780 g kg-1 clay; 110 g kg-1 silt and 110 g kg-1 sand, with an average slope of 3 %. Undisturbed soil cores were sampled at a depth of 0.10-0.13 m, at three different points within the coffee plantation: (a from under the wheel track, where equipment used in farm operations passes; (b in - between tracks and (c under the coffee canopy. Six linear transects were established in the experimental area: three transects along and three across the coffee rows. This way, 161 samples were collected in the transect across the coffee rows, from the three locations, while 117 samples were collected in the direction along the row. The shortest sampling distance in the transect across the row was 4 m, and 0.5 m for the transect along the row. No clear patterns of the preconsolidation pressure values were observed in the 200 m transect. The results of the semivariograms for both variables indicated a high nugget value and short range for the studied parameters of all transects. A cyclic pattern of the parameters was observed for the across-rows transect. An inverse relationship between preconsolidation pressure and soil moisture was clearly observed in the samples from under the track, in both directions.

  8. Wet Work and Barrier Function.

    Science.gov (United States)

    Fartasch, Manigé

    2016-01-01

    Wet work defined as unprotected exposure to humid environments/water; high frequencies of hand washing procedures or prolonged glove occlusion is believed to cause irritant contact dermatitis in a variety of occupations. This review considers the recent studies on wet-work exposure and focuses on its influence on barrier function. There are different methods to study the effect of wet work on barrier function. On the one hand, occupational cohorts at risk can be monitored prospectively by skin bioengineering technology and clinical visual scoring systems; on the other hand, experimental test procedures with defined application of water, occlusion and detergents are performed in healthy volunteers. Both epidemiological studies and the results of experimental procedures are compared and discussed. A variety of epidemiological studies analyze occupational cohorts at risk. The measurement of transepidermal water loss, an indicator of the integrity of the epidermal barrier, and clinical inspection of the skin have shown that especially the frequencies of hand washing and water contact/contact to aqueous mixtures seem to be the main factors for the occurrence of barrier alterations. On the other hand, in a single cross-sectional study, prolonged glove wearing (e.g. occlusion for 6 h per shift in clean-room workers) without exposure to additional hazardous substances seemed not to affect the skin negatively. But regarding the effect of occlusion, there is experimental evidence that previously occluded skin challenged with sodium lauryl sulfate leads to an increased susceptibility to the irritant with an aggravation of the irritant reaction. These findings might have relevance for the real-life situation in so far as after occupational glove wearing, the skin is more susceptible to potential hazards to the skin even during leisure hours.

  9. Wetting properties of nanostructured surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Ramos-Canut, S. [Laboratoire de Physique de la Matiere Condensee et Nanostructures (UMR CNRS 5586), Universite Claude Bernard Lyon 1, 69622 Villeurbanne Cedex (France)]. E-mail: ramos@lpmcn.univ-lyon1.fr

    2006-04-15

    Swift heavy ion irradiation is a powerful tool to tailor surfaces under controlled conditions at a nanometric scale. The growing importance of nanostructured surfaces for a wide variety of applications and fundamental investigations is now well established. In this paper I will mainly discuss the interest of such surfaces for investigations concerning solid-liquid interfaces. The role played by topographical defects on wetting properties of solid surfaces, and both the dissipative and the confinement effects on the interface will be demonstrated by simple examples.

  10. Single-metalloprotein wet biotransistor

    Science.gov (United States)

    Alessandrini, Andrea; Salerno, Marco; Frabboni, Stefano; Facci, Paolo

    2005-03-01

    Metalloproteins are redox molecules naturally shuttling electrons with high efficiency between molecular partners. As such, they are candidates of choice for bioelectronics. In this work, we have used bacterial metalloprotein azurin, hosted in a nanometer gap between two electrically biased gold electrodes, to demonstrate an electrochemically gated single-molecule transistor operating in an aqueous environment. Gold-chemisorbed azurin shows peaks in tunneling current upon changing electrode potential and a related variation in tunneling barrier transparency which can be exploited to switch an electron current through it. These results suggest the wet approach to molecular electronics as a viable method for exploiting electron transfer of highly specialized biomolecules.

  11. A basin redox transect at the dawn of animal life

    Science.gov (United States)

    Sperling, Erik A.; Halverson, Galen P.; Knoll, Andrew H.; Macdonald, Francis A.; Johnston, David T.

    2013-06-01

    Multiple eukaryotic clades make their first appearance in the fossil record between ~810 and 715 Ma. Molecular clock studies suggest that the origin of animal multicellularity may have been part of this broader eukaryotic radiation. Animals require oxygen to fuel their metabolism, and low oxygen levels have been hypothesized to account for the temporal lag between metazoan origins and the Cambrian radiation of large, ecologically diverse animals. Here, paleoredox conditions were investigated in the Fifteenmile Group, Ogilvie Mountains, Yukon, Canada, which hosts an 811 Ma ash horizon and spans the temporal window that captures the inferred origin and early evolution of animals. Iron-based redox proxies, redox-sensitive trace elements, organic carbon percentages and pyrite sulfur isotopes were analyzed in seven stratigraphic sections along two parallel basin transects. These data suggest that for this basin, oxygenated shelf waters overlay generally anoxic deeper waters. The anoxic water column was dominantly ferruginous, but brief periods of euxinia likely occurred. These oscillations coincide with changes in total organic carbon, suggesting euxinia was primarily driven by increased organic carbon loading. Overall, these data are consistent with proposed quantitative constraints on Proterozoic atmospheric oxygen being greater than 1% of modern levels, but less than present levels. Comparing these oxygen levels against the likely oxygen requirements of the earliest animals, both theoretical considerations and the ecology of modern oxygen-deficient settings suggest that the inferred oxygen levels in the mixed layer would not have been prohibitive to the presence of sponges, eumetazoans or bilaterians. Thus the evolution of the earliest animals was probably not limited by the low absolute oxygen levels that may have characterized Neoproterozoic oceans, although these inferred levels would constrain animals to very small sizes and low metabolic rates.

  12. Artificial ultra-fine aerosol tracers for highway transect studies

    Science.gov (United States)

    Cahill, Thomas A.; Barnes, David E.; Wuest, Leann; Gribble, David; Buscho, David; Miller, Roger S.; De la Croix, Camille

    2016-07-01

    The persistent evidence of health impacts of roadway aerosols requires extensive information for urban planning to avoid putting populations at risk, especially in-fill projects. The required information must cover both highway aerosol sources as well as transport into residential areas under a variety of roadway configurations, traffic conditions, downwind vegetation, and meteorology. Such studies are difficult and expensive to do, but were easier in the past when there was a robust fine aerosol tracer uniquely tied to traffic - lead. In this report we propose and test a modern alternative, highway safety flare aerosols. Roadway safety flares on vehicles in traffic can provide very fine and ultra-fine aerosols of unique composition that can be detected quantitatively far downwind of roadways due to a lack of upwind interferences. The collection method uses inexpensive portable aerosol collection hardware and x-ray analysis protocols. The time required for each transect is typically 1 h. Side by side tests showed precision at ± 4%. We have evaluated this technique both by aerosol removal in vegetation in a wind tunnel and by tracking aerosols downwind of freeways as a function of season, highway configuration and vegetation coverage. The results show that sound walls for at-grade freeways cause freeway pollution to extend much farther downwind than standard models predict. The elevated or fill section freeway on a berm projected essentially undiluted roadway aerosols at distances well beyond 325 m, deep into residential neighborhoods. Canopy vegetation with roughly 70% cover reduced very fine and ultra-fine aerosols by up to a factor of 2 at distances up to 200 m downwind.

  13. Mold management of wetted carpet.

    Science.gov (United States)

    Ong, Kee-Hean; Dixit, Anupma; Lewis, Roger D; MacDonald Perkins, Maureen; Backer, Denis; Condoor, Sridhar; Emo, Brett; Yang, Mingan

    2014-01-01

    This study evaluated the growth and removal of fungi on wetted carpet using newly designed technologies that rely on physical principles of steam, heat, and fluid flow. Sixty samples of carpet were embedded with heat-treated house dust, followed by embedding, wearing with a hexapod, and wetting. Samples were inoculated using a liquid suspension of Cladosporium sphaerospermum prior to placement over a water-saturated foam pad. Incubation times were 24 hr, 7 days, and 30 days. Cleaning was performed using three methods; high-flow hot water extraction, hot water and detergent, and steam. Fungal loading increased from approximately 1500 colony forming units per area (CFU/cm(2)) in 24 hr to a maximum of approximately 10,200 CFU/cm(2) after 7 days with a slight decline to 9700 CFU/cm(2) after 30 days incubation. Statistically significant differences were found among all three methods for removal of fungi for all three time periods (p Steam-vapor was significantly better than the alternative methods (p steam has a consistent fungal removal rate, the detergent and high-flow, hot water methods decline in efficiency with increasing incubation time.

  14. Elucidating the mysteries of wetting.

    Energy Technology Data Exchange (ETDEWEB)

    Webb, Edmund Blackburn, III (,; ); Bourdon, Christopher Jay; Grillet, Anne Mary; Sackinger, Philip A.; Grest, Gary Stephen; Emerson, John Allen; Ash, Benjamin Jesse; Heine, David R.; Brooks, Carlton, F.; Gorby, Allen D.

    2005-11-01

    Nearly every manufacturing and many technologies central to Sandia's business involve physical processes controlled by interfacial wetting. Interfacial forces, e.g. conjoining/disjoining pressure, electrostatics, and capillary condensation, are ubiquitous and can surpass and even dominate bulk inertial or viscous effects on a continuum level. Moreover, the statics and dynamics of three-phase contact lines exhibit a wide range of complex behavior, such as contact angle hysteresis due to surface roughness, surface reaction, or compositional heterogeneities. These thermodynamically and kinetically driven interactions are essential to the development of new materials and processes. A detailed understanding was developed for the factors controlling wettability in multicomponent systems from computational modeling tools, and experimental diagnostics for systems, and processes dominated by interfacial effects. Wettability probed by dynamic advancing and receding contact angle measurements, ellipsometry, and direct determination of the capillary and disjoining forces. Molecular scale experiments determined the relationships between the fundamental interactions between molecular species and with the substrate. Atomistic simulations studied the equilibrium concentration profiles near the solid and vapor interfaces and tested the basic assumptions used in the continuum approaches. These simulations provide guidance in developing constitutive equations, which more accurately take into account the effects of surface induced phase separation and concentration gradients near the three-phase contact line. The development of these accurate models for dynamic multicomponent wetting allows improvement in science based engineering of manufacturing processes previously developed through costly trial and error by varying material formulation and geometry modification.

  15. Wetting and Non-Wetting Models of Black Carbon Activation

    Science.gov (United States)

    Henson, B. F.; Laura, S.

    2006-12-01

    We present the results of recent modeling studies on the activation of black carbon (BC) aerosol to form cloud condensation nuclei (CCN). We use a model of BC activation based on a general modification of the Koehler equation for insoluble activation in which we introduce a term based on the activity of water adsorbed on the particle surface. We parameterize the model using the free energy of adsorption, a parameter directly comparable to laboratory measurements of water adsorption on carbon. Although the model of the water- surface interaction is general, the form of the activation equation that results depends upon a further model of the distribution of water on the particle. One possible model involves the symmetric growth of a water shell around the isoluble particle core (wetting). This model predicts upper and lower bounding curves for the activation supersaturation given by the range of water interaction energies from hydrophobic to hydrophilic which are in agreement with a large body of recent activation data. The resulting activation diameters are from 3 to 10 times smaller than activation of soluble particles of identical dry diameter. Another possible model involves an exluded liquid droplet growing in contact with the particle (non-wetting). The geometry of this model much more resembles classic assumptions of heterogeneous nucleation theory. This model can yield extremely high activation supersaturation as a function of diameter, as has been observed in some experiments, and enables calculations in agreement with some of these results. We discuss these two geometrical models of water growth, the different behaviors predicted by the resulting activation equation, and the means to determine which model of growth is appropriate for a given BC particle characterized by either water interaction energy or morphology. These simple models enable an efficient and physically reasonable means to calculate the activation of BC aerosol to form CCN based upon a

  16. SWFSC/MMTD/ETP: Stenella Abundance Research - Line Transect and Ecosystem (STAR-LITE) 2007

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Stenella Abundance Research Line Transect and Ecosystem (STAR-LITE) cruise is a process-oriented research project related to survey methodologies.

  17. A summary of the 2004 Devils Lake Wetland Management District roadside transect survey

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report is on the 2004 road transect surveys conducted on the Devils Lake Wetland Management District. Surveys were preformed in an effort to fill the data gap...

  18. Tree Transect Starting Locations (Points) at Sand Creek Massacre National Historic Site, Colorado

    Data.gov (United States)

    National Park Service, Department of the Interior — A vector point dataset representing the starting location of tree transects at Sand Creek Massacre NHS as part of a University of Colorado research study.

  19. Monte Vista Refuge : Instructions for conducting the waterfowl production survey based on duck nesting transects

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This is the protocol for conducting waterfowl production surveys based on duck nest transects for the Monte Vista National Wildlife Refuge. The basic approach, field...

  20. Guided transect sampling - a new design combining prior information and field surveying

    Science.gov (United States)

    Anna Ringvall; Goran Stahl; Tomas Lamas

    2000-01-01

    Guided transect sampling is a two-stage sampling design in which prior information is used to guide the field survey in the second stage. In the first stage, broad strips are randomly selected and divided into grid-cells. For each cell a covariate value is estimated from remote sensing data, for example. The covariate is the basis for subsampling of a transect through...

  1. Variability of land degradation along topographic transects in two Mediterranean areas

    Science.gov (United States)

    Kotb Abd-Elmabod, Sameh; Anaya-Romero, María; Phillips, Jonathan D.; Jordán, Antonio; Muñoz-Rojas, Miriam; de la Rosa, Diego

    2013-04-01

    This study aims to investigate the influence of topography, soil factors and climate conditions on land degradation along topographic transects in two Mediterranean areas: Seville (southern Spain) and El-Fayoum (northern Egypt). Elevation and slope gradient information from both study sites were obtained from Shuttle Radar Topography Mission (SRTM) data, processed using ENVI 4.7. Additionally, topographic transects were developed using ArcGIS 10 software. To represent the highest variability in elevation, lithology, soil and land use in each site, one representative topographic transect from El-Fayoum and two topographic transects from Seville were selected. Soil characteristics along each of the topographic transect were obtained by mapping land surveying and laboratory analyses data. MicroLEIS DSS (Pantanal and Raizal submodels) was used to assess soil contamination with phosphorus, nitrogen, heavy metals and pesticides and water erosion vulnerability along the topographic transects for each study site using soil data, including depth, texture, drainage, carbonate content, salinity, sodium saturation, organic matter content and acidity (pH). Additionally, monthly average values of climate variables (mean temperature, maximum and minimum rainfall and number of rainy days) have been used. The results obtained by Raizal and Pantanal models suggest that lower elevation areas from transects show low vulnerability classes in both degradation processes (water erosion and soil contamination), when compared to uplands. The variation of climate conditions and soil factors along the Seville and El-Fayoum transects were responsible for the observed variability in both soil degradation processes (erosion and contamination). Key words: MicroLEIS DSS, soil degradation, soil factors, topography, DEM

  2. Transect sampling of vegetation formations of phanerophytes and chamaephytes (I): methodological fundamentals

    OpenAIRE

    Cámara Artigas, Rafael; Díaz del Olmo, Fernando

    2013-01-01

    This study presents a quantitative geobotanical method of inventory for homogeneous vegetation formations (phanerophytes and chamaephytes) (method MIFC). The technique used is an inventory of vegetation (phanerophytes and chamaephytes) in transects of 50x2 m. Resulting in plots of 0.1 ha., the attributes and the relative position of the vegetation along the transect. For the study of vegetation, the analytical basis method considers 10 sample plots. The results provide data on biodiversity (S...

  3. Drop splashing is independent of substrate wetting

    CERN Document Server

    Latka, Andrzej; Nagel, Sidney R; de Pablo, Juan J

    2016-01-01

    A liquid drop impacting a dry solid surface with sufficient kinetic energy will splash, breaking apart into numerous secondary droplets. This phenomenon shows many similarities to forced wetting, including the entrainment of air at the contact line. Because of these similarities and the fact that forced wetting has been shown to depend on the wetting properties of the surface, existing theories predict splashing to depend on wetting properties as well. However, using high-speed interference imaging we observe that wetting properties have no effect on splashing for various liquid-surface combinations. Additionally, by fully resolving the Navier-Stokes equations at length and time scales inaccessible to experiments, we find that the shape and motion of the air-liquid interface at the contact line are independent of wettability. We use these findings to evaluate existing theories and to compare splashing with forced wetting.

  4. Quantification of reef benthos communities and variability inherent to the monitoring using video transect method.

    Science.gov (United States)

    Ramos, Carla Alecrim Colaço; Amaral, Fernanda Duarte; de Kikuchi, Ruy Kenji Papa; Chaves, Eduardo Marocci; de Melo, Gabriel Rivas

    2010-03-01

    Long-term monitoring program of organisms is the most recommended for understanding changing processes on reefs. The video transect method presents advantages for that. Specialists state that it is important to make sure that the recorded coverage is always the same between campaigns, so that differences in results may be entirely attributed to environmental changes. This study aimed to test the capability of implementing this requirement through tracking simulation and its validity for monitoring the benthic communities of reefs using the video transect method. Ten transects 20 m long were established in Todos os Santos Bay coral reefs. Subsequent to the first transect capture, a second diver repeated the same track, simulating two different monitoring campaigns. Data were transformed and a matrix of similarity was generated using Bray-Curtis' Index. ANOSIM analysis was performed to test the similarity of the ten transects and its repetitions. The result, R = 0.08 (P = 0.928), shows that reef monitoring using video transect, the way it is described in the literature, is appropriate, but it is important to consider some premises discussed in this work.

  5. Optimized wet clutches:simulation and tribotesting

    OpenAIRE

    2006-01-01

    Wet clutches are used in a variety of different machinery. Wet clutches and brakes are frequently used to distribute torque in vehicle drive-trains. The clutches can be located in e.g. automatic transmissions or limited slip differentials. Their frictional behavior is of great importance for the overall vehicle behavior and has to be thoroughly investigated when designing new wet clutch applications. Frictional behavior is normally investigated in test rigs where complete friction discs are t...

  6. The Wet-Dog Shake

    CERN Document Server

    Dickerson, Andrew; Bauman, Jay; Chang, Young-Hui; Hu, David

    2010-01-01

    The drying of wet fur is a critical to mammalian heat regulation. In this fluid dynamics video, we show a sequence of films demonstrating how hirsute animals to rapidly oscillate their bodies to shed water droplets, nature's analogy to the spin cycle of a washing machine. High-speed videography and fur-particle tracking is employed to determine the angular position of the animal's shoulder skin as a function of time. X-ray cinematography is used to track the motion of the skeleton. We determine conditions for drop ejection by considering the balance of surface tension and centripetal forces on drops adhering to the animal. Particular attention is paid to rationalizing the relationship between animal size and oscillation frequency required to self-dry.

  7. Externally Wetted Ionic Liquid Thruster

    Science.gov (United States)

    Lozano, P.; Martinez-Sanchez, M.; Lopez-Urdiales, J. M.

    2004-10-01

    This paper presents initial developments of an electric propulsion system based on ionic liquid ion sources (ILIS). Propellants are ionic liquids, which are organic salts with two important characteristics; they remain in the liquid state at room temperature and have negligible vapor pressure, thus allowing their use in vacuum. The working principles of ILIS are similar to those of liquid metal ion sources (LMIS), in which a Taylor cone is electrostatically formed at the tip of an externally wetted needle while ions are emitted directly from its apex. ILIS have the advantage of being able to produce negative ions that have similar masses than their positive counterparts with similar current levels. This opens up the possibility of achieving plume electrical neutrality without electron emitters. The possible multiplexing of these emitters is discussed in terms of achievable thrust density for applications other than micro-propulsion.

  8. Wet granular walkers and climbers

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Z S; Steinberger, A; Seemann, R; Herminghaus, S, E-mail: audrey.steinberger@ens-lyon.fr [Max Planck Institute for Dynamics and Self-Organization, Bunsenstrasse 10, D-37073 Goettingen (Germany)

    2011-05-15

    Mechanisms of locomotion in microscopic systems are of great interest not only for technological applications but also for the sake of understanding, and potentially harnessing, processes far from thermal equilibrium. Downscaling is a particular challenge and has led to a number of interesting concepts, including thermal ratchet systems and asymmetric swimmers. Here we present a granular ratchet system employing a particularly robust mechanism that can be implemented in various settings. The system consists of wetted spheres of different sizes that adhere to each other, and are subject to a symmetric oscillating, zero average external force field. An inherent asymmetry in the mutual force network leads to force rectification and hence to locomotion. We present a simple model that accounts for the observed behaviour, underscores its robustness and suggests a potential scalability of the concept.

  9. Carbon nanotube fiber spun from wetted ribbon

    Science.gov (United States)

    Zhu, Yuntian T; Arendt, Paul; Zhang, Xiefei; Li, Qingwen; Fu, Lei; Zheng, Lianxi

    2014-04-29

    A fiber of carbon nanotubes was prepared by a wet-spinning method involving drawing carbon nanotubes away from a substantially aligned, supported array of carbon nanotubes to form a ribbon, wetting the ribbon with a liquid, and spinning a fiber from the wetted ribbon. The liquid can be a polymer solution and after forming the fiber, the polymer can be cured. The resulting fiber has a higher tensile strength and higher conductivity compared to dry-spun fibers and to wet-spun fibers prepared by other methods.

  10. Dissolved Ti in the US GEOTRACES Atlantic Transect

    Science.gov (United States)

    Murray, R. W.; Moran, S.; Kelly, R. P.; Kelley, K. A.; Graham, D.

    2012-12-01

    data for dissolved Ti in the open Atlantic. Croot's values and our values both agree well with Orians' original analyses, which not only confirms our respective analytical approaches but also suggests that the GEOTRACES rosette system, small parts of which contain Ti, does not contaminate seawater samples for Ti. We also present data from the 2011 GEOTRACES station taken at BATS in the western Atlantic and at Station 11 from the 2010 GEOTRACES transect in the eastern Atlantic. Our profile to 2000 m (= 213 pM) is similar to that of Orians et al. (1990) to the same depth, but extends deeper to 3597 m. Unlike the deep Pacific profile of Orians et al. (1990) from Station PAPA, which extends to 3860 m and reaches a maximum of 263 pM at that depth, our BATS profile is essentially invariant with depth below 2000 m. We observe a similar deepwater distribution at Station 11, which shows an increase from 60 pM near the surface to a maximum of 180 pM at 700 m, followed perhaps by a slight decrease to 130 pM at 3300 m depth.

  11. 7 CFR 29.2570 - Wet (W).

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Wet (W). 29.2570 Section 29.2570 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing...-Cured Tobacco (u.s. Types 22, 23, and Foreign Type 96) § 29.2570 Wet (W). Any sound tobacco...

  12. 7 CFR 29.3567 - Wet (W).

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Wet (W). 29.3567 Section 29.3567 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Type 95) § 29.3567 Wet (W). Any sound tobacco containing excessive moisture to the extent that it is...

  13. 7 CFR 29.2316 - Wet (W).

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Wet (W). 29.2316 Section 29.2316 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... INSPECTION Standards Official Standard Grades for Virginia Fire-Cured Tobacco (u.s. Type 21) § 29.2316 Wet...

  14. 7 CFR 29.3077 - Wet (W).

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Wet (W). 29.3077 Section 29.3077 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Wet (W). Any sound tobacco containing excessive moisture to the extent that it is in an unsafe...

  15. 7 CFR 29.1083 - Wet (W).

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Wet (W). 29.1083 Section 29.1083 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Type 92) § 29.1083 Wet (W). Any sound tobacco containing excessive moisture to the extent that it is...

  16. Characteristics of wet work in nurses

    NARCIS (Netherlands)

    Jungbauer, FHW; Steenstra, FB; Groothoff, JW; Coenraads, PJ

    Background objectives: Nursing is known for its high prevalence of hand dermatitis, mainly caused by the intense exposure to wet work in nursing activities. We aimed to study the characteristics of wet work exposure in nursing. Method: Trained observers monitored the duration and frequency of

  17. Curvature controlled wetting in two dimensions

    DEFF Research Database (Denmark)

    Gil, Tamir; Mikheev, Lev V.

    1995-01-01

    . As the radius of the substrate r0→∞, the leading effect of the curvature is adding the Laplace pressure ΠL∝r0-1 to the pressure balance in the film. At temperatures and pressures under which the wetting is complete in planar geometry, Laplace pressure suppresses divergence of the mean thickness of the wetting...

  18. Location and description of transects for ecological studies in floodplain forests of the lower Suwannee River, Florida

    Science.gov (United States)

    Lewis, L.J.; Light, H.M.; Darst, M.R.

    2001-01-01

    Twelve transects were established in floodplain forests along the lower Suwannee River, Florida, as the principal data collection sites for a comprehensive study conducted by the U.S. Geological Survey and the Suwannee River Water Management District from 1996 to 2001. Data collected along the 12 transects included hydrologic conditions, land-surface elevations, soils, and vegetation of floodplain forests in relation to river flow. Transect locations are marked in the field with permanent markers at approximately 30 meter intervals. Detailed descriptions of the 12 transects and their locations are provided so that they can be used for future ecological studies. Descriptions of the transects include contact information necessary for access to the property on which the transects are located, maps showing transect locations and routes from the nearest city or major road, small scale maps of each transect showing marker locations, latitude and longitude of each marker, compass bearings of each transect line and graphs showing land-surface elevations of the transect with marker locations.

  19. Upregulation of S100A4 after spinal cord transection in adult rats

    Institute of Scientific and Technical Information of China (English)

    Kai-hua ZHANG; Shu HAN; Pei-hua LU; Xiao-ming XU

    2004-01-01

    AIM: To investigate whether spinal cord transection induces changes of gene expression of S 100A4 protein.METHODS: In a spinal cord transection model, S 100A4 expression and cellular localization were examined using cDNA microarray, Northern blot, immunohistochemistry, and immunofluorescence double-labeling methods.RESULTS: There was very limited S 100A4 mRNA expression in the control spinal cord. However, S 100A4 mRNA expression was increased significantly in both the rostral and caudal spinal cord segments adjacent to the injury site.Specifically, S100A4 gene expression was substantially increased at d 2, peaked at d 7 and d 14, and remained high up to 28 d post-injury. During its peak expression, S100A4 protein was localized in astrocytes of the spinal cord within 5 mm from the site of spinal transection. CONCLUSION: Spinal cord transection induces prolonged S 100A4 expression at both mRNA and protein levels in areas close to the injury site. Increased expression of S100A4 in astrocytes after spinal cord transection may indicate that this molecule may play a role in astrocytic responses to injury.

  20. A brain-machine-muscle interface for restoring hindlimb locomotion after complete spinal transection in rats.

    Directory of Open Access Journals (Sweden)

    Monzurul Alam

    Full Text Available A brain-machine interface (BMI is a neuroprosthetic device that can restore motor function of individuals with paralysis. Although the feasibility of BMI control of upper-limb neuroprostheses has been demonstrated, a BMI for the restoration of lower-limb motor functions has not yet been developed. The objective of this study was to determine if gait-related information can be captured from neural activity recorded from the primary motor cortex of rats, and if this neural information can be used to stimulate paralysed hindlimb muscles after complete spinal cord transection. Neural activity was recorded from the hindlimb area of the primary motor cortex of six female Sprague Dawley rats during treadmill locomotion before and after mid-thoracic transection. Before spinal transection there was a strong association between neural activity and the step cycle. This association decreased after spinal transection. However, the locomotive state (standing vs. walking could still be successfully decoded from neural recordings made after spinal transection. A novel BMI device was developed that processed this neural information in real-time and used it to control electrical stimulation of paralysed hindlimb muscles. This system was able to elicit hindlimb muscle contractions that mimicked forelimb stepping. We propose this lower-limb BMI as a future neuroprosthesis for human paraplegics.

  1. Crustal architecture across Phanerozoic Australia along the Eromanga-Brisbane Geoscience Transect: evolution and analogues

    Science.gov (United States)

    Finlayson, D. M.

    1993-03-01

    The crustal architecture across Phanerozoic Australia has been established from seismic data along an 1100-km-long east-west transect, the Eromanga-Brisbane Geoscience Transect. This has enabled a better understanding of deep structures and processes that have controlled the development of major sedimentary basin systems. It has shown that crustal dynamics throughout geological history have played an important role in the development of these sedimentary basins and that structures developed during the early Palaeozoic have influenced, and continue to influence, basin systems. The transect crosses three major basement provinces of the Tasman Orogenic System in eastern Australia - the Thomson, northern Lachlan, and New England Orogens. The basement geology in the transect region has, until now, been only poorly understood because it is largely obscured by the Mesozoic cover rocks of the Eromanga, Surat and Clarence-Moreton Basins. The transect interpretation has firmly identified crustal-scale ramp structures, multiple intra-crustal detachment surfaces, strike-slip fault architecture, lower-crustal magmatism/underplating, Mono remobilisation, and intra-crustal terranes in the geological reconstructions of southern Queensland. The boundaries between the orogens, the Foyleview and Burunga—Mooki Geosutures, have been identified as lithospheric-scale structures that have influenced the evolution of the Tasman Orogenic System as a whole.

  2. Forced wetting of a reactive surface.

    Science.gov (United States)

    Blake, T D

    2012-11-01

    The dynamic wetting of water on gelatin-coated poly(ethylene terephthalate) (GC-PET) has been investigated by forced wetting over a wide speed range and compared with earlier data obtained with unmodified PET. The results were analysed according to the molecular-kinetic theory of dynamic wetting (MKT). Both substrates show complex behaviour, with separate low- and high-speed modes. For the GC-PET, this is attributed to a rapid change in the wettability of the substrate on contact with water, specifically a surface molecular transformation from hydrophobic to hydrophilic. This results in a smooth wetting transition from one mode to the other. For the PET, the bimodal behaviour is attributed to surface heterogeneity, with the low-speed dynamics dominated by interactions with polar sites on the substrate that become masked at higher speeds. In this case, the transition is discontinuous. The study has general ramifications for the investigation of any wetting processes in which a physicochemical transformation takes place at the solid surface on contact with the liquid. In particular, it shows how forced wetting, combined with the MKT, can reveal subtle details of the processes involved. It is unlikely that similar insight could be gained from spontaneous wetting studies, such as spreading drops.

  3. Mapping soil water dynamics and a moving wetting front by spatiotemporal inversion of electromagnetic induction data

    Science.gov (United States)

    Huang, J.; Monteiro Santos, F. A.; Triantafilis, J.

    2016-11-01

    Characterization of the spatiotemporal distribution of soil volumetric water content (θ) is fundamental to agriculture, ecology, and earth science. Given the labor intensive and inefficient nature of determining θ, apparent electrical conductivity (ECa) measured by electromagnetic induction has been used as a proxy. A number of previous studies have employed inversion algorithms to convert ECa data to depth-specific electrical conductivity (σ) which could then be correlated to soil θ and other soil properties. The purpose of this study was to develop a spatiotemporal inversion algorithm which accounts for the temporal continuity of ECa. The algorithm was applied to a case study where time-lapse ECa was collected on a 350 m transect on seven different days on an alfalfa farm in the USA. Results showed that the approach was able to map the location of moving wetting front along the transect. Results also showed that the spatiotemporal inversion algorithm was more precise (RMSE = 0.0457 cm3/cm3) and less biased (ME = -0.0023 cm3/cm3) as compared with the nonspatiotemporal inversion approach (0.0483 cm3/cm3 and ME = -0.0030 cm3/cm3, respectively). In addition, the spatiotemporal inversion algorithm allows for a reduced set of ECa surveys to be used when non abrupt changes of soil water content occur with time. To apply this spatiotemporal inversion algorithm beyond low induction number condition, full solution of the EM induction phenomena can be studied in the future.

  4. Introduction to Special Section: The Trans-Alaska Crustal Transect (TACT) Across Arctic Alaska

    Science.gov (United States)

    Plafker, George; Mooney, Walter D.

    1997-01-01

    This special section of the Journal of Geophysical Research addresses the composition and structural evolution of the lithosphere in northern Alaska. Investigations reported in this section were mainly undertaken as part of the Trans-Alaska Crustal Transect (TACT), an integrated geological and geophysical transect of the entire Alaskan lithosphere along a north-south corridor undertaken from 1984 to 1992 (Figure 1). The onshore segment of the transect approximately follows along the route of the trans-Alaskan pipeline; the offshore segment extends across the continental margin in the Gulf of Alaska to the Pacific plate. The TACT line is unique in that it provides a coordinated onshore/offshore geological and geophysical traverse of the North American plate in Alaska from the active convergent Pacific margin to the passive Arctic margin of the continent.

  5. Dark rearing maintains tyrosine hydroxylase expression in retinal amacrine cells following optic nerve transection

    Institute of Scientific and Technical Information of China (English)

    Wei Wan; Zhenghai Liu; Xiaosheng Wang; Xuegang Luo

    2012-01-01

    The present study examined changes in retinal tyrosine hydroxylase (TH) expression in rats having undergone optic nerve transection and housed under a normal day/night cycle or in the dark. The aim was to investigate the effects of amacrine cells on axonal regeneration in retinal ganglion cells and on the synapses that transmit visual signals. The results revealed that retinal TH expression gradually decreased following optic nerve transection in rats housed under a normal day/night cycle, reaching a minimum at 5 days. In contrast, retinal TH expression decreased to a minimum at 1 day following optic nerve transection in dark reared rats, gradually increasing afterward and reaching a normal level at 5-7 days. The number of TH-positive synaptic particles correlated with the TH levels, indicating that dark rearing can help maintain TH expression during the synaptic degeneration stage (5-7 days after optic nerve injury) in retinal amacrine cells.

  6. Endovascular stent graft treatment of acute thoracic aortic transections due to blunt force trauma.

    LENUS (Irish Health Repository)

    Bjurlin, Marc A

    2012-02-01

    Endovascular stent graft treatment of acute thoracic aortic transections is an encouraging minimally invasive alternative to open surgical repair. Between 2006 and 2008, 16 patients with acute thoracic aortic transections underwent evaluation at our institution. Seven patients who were treated with an endovascular stent graft were reviewed. The mean Glasgow Coma Score was 13.0, probability of survival was .89, and median injury severity score was 32. The mean number of intensive care unit days was 7.7, mean number of ventilator support days was 5.4, and hospital length of stay was 10 days. Mean blood loss was 285 mL, and operative time was 143 minutes. Overall mortality was 14%. Procedure complications were a bleeding arteriotomy site and an endoleak. Endovascular treatment of traumatic thoracic aortic transections appears to demonstrate superior results with respect to mortality, blood loss, operative time, paraplegia, and procedure-related complications when compared with open surgical repair literature.

  7. Wetting transitions at soft, sliding interfaces

    Science.gov (United States)

    Martin, A.; Clain, J.; Buguin, A.; Brochard-Wyart, F.

    2002-03-01

    We observe (by optical interferometry) the contact of a rubber cap squeezing a nonwetting liquid against a plate moving at velocity U. At low velocities, the contact is dry. It becomes partially wet above a threshold velocity Vc1, with two symmetrical dry patches on the rear part. Above a second velocity Vc2, the contact is totally wet. This regime U>Vc2 corresponds to the hydroplaning of a car (decelerating on a wet road). We interpret the transitions at Vc1, Vc2 in terms of a competition between (a) liquid invasion induced by shear (b) spontaneous dewetting of the liquid (between nonwettable surfaces).

  8. Catalytic wet oxidation of black liquor

    OpenAIRE

    Viader Riera, Gerard

    2012-01-01

    The major aspects of wet air oxidation and catalytic wet air oxidation have been reviewed in this work paying special attention to the reaction mechanisms, kinetics and the industrial process. In the experimental section a set of heterogeneous catalysts have been tested in the wet oxidation of non-wood black liquor. The oxidation runs were performed batchwise in a laboratory-scale mechanically stirred slurry reactor for 1 h at a temperature of 170°C and total pressure of 12 bar. Pure oxygen w...

  9. Our experience with wet-wrap treatment.

    Science.gov (United States)

    Albarrán-Planelles, C; Jiménez-Gallo, D; Linares-Barrios, M; Martínez-Rodríguez, A

    2014-04-01

    A wide range of treatments are currently available for severe atopic dermatitis, including systemic therapies such as ciclosporin, corticosteroids, azathioprine, methotrexate, mofetil mycophenolate, and omalizumab. In patients who can no longer take systemic drugs or who need a dose reduction, wet-wrap treatment can be an excellent option. To date, wet wraps have mostly been used in severe cases of childhood atopic dermatitis. We report our experience with wet-wrap treatment in 5 adults with atopic dermatitis and 2 with nodular prurigo. The results were satisfactory and there were few adverse effects. Copyright © 2013 Elsevier España, S.L. and AEDV. All rights reserved.

  10. Heat tracing to determine spatial patterns of hyporheic exchange across a river transect

    Science.gov (United States)

    Lu, Chengpeng; Chen, Shuai; Zhang, Ying; Su, Xiaoru; Chen, Guohao

    2017-03-01

    Significant spatial variability of water fluxes may exist at the water-sediment interface in river channels and has great influence on a variety of water issues. Understanding the complicated flow systems controlling the flux exchanges along an entire river is often limited due to averaging of parameters or the small number of discrete point measurements usually used. This study investigated the spatial pattern of the hyporheic flux exchange across a river transect in China, using the heat tracing approach. This was done with measurements of temperature at high spatial resolution during a 64-h monitoring period and using the data to identify the spatial pattern of the hyporheic exchange flux with the aid of a one-dimensional conduction-advection-dispersion model (VFLUX). The threshold of neutral exchange was considered as 126 L m-2 d-1 in this study and the heat tracing results showed that the change patterns of vertical hyporheic flux varied with buried depth along the river transect; however, the hyporheic flux was not simply controlled by the streambed hydraulic conductivity and water depth in the river transect. Also, lateral flow dominated the hyporheic process within the shallow high-permeability streambed, while the vertical flow was dominant in the deep low-permeability streambed. The spatial pattern of hyporheic exchange across the river transect was naturally controlled by the heterogeneity of the streambed and the bedform of the stream cross-section. Consequently, a two-dimensional conceptual illustration of the hyporheic process across the river transect is proposed, which could be applicable to river transects of similar conditions.

  11. High population density of black-handed spider monkeys (Ateles geoffroyi) in Costa Rican lowland wet forest.

    Science.gov (United States)

    Weghorst, Jennifer A

    2007-04-01

    The main objective of this study was to estimate the population density and demographic structure of spider monkeys living in wet forest in the vicinity of Sirena Biological Station, Corcovado National Park, Costa Rica. Results of a 14-month line-transect survey showed that spider monkeys of Sirena have one of the highest population densities ever recorded for this genus. Density estimates varied, however, depending on the method chosen to estimate transect width. Data from behavioral monitoring were available to compare density estimates derived from the survey, providing a check of the survey's accuracy. A combination of factors has most probably contributed to the high density of Ateles, including habitat protection within a national park and high diversity of trees of the fig family, Moraceae. Although natural densities of spider monkeys at Sirena are substantially higher than those recorded at most other sites and in previous studies at this site, mean subgroup size and age ratios were similar to those determined in previous studies. Sex ratios were similar to those of other sites with high productivity. Although high densities of preferred fruit trees in the wet, productive forests of Sirena may support a dense population of spider monkeys, other demographic traits recorded at Sirena fall well within the range of values recorded elsewhere for the species.

  12. Modelling agricultural suitability along soil transects under current conditions and improved scenario of soil factors

    Science.gov (United States)

    Abd-Elmabod, Sameh K.; Jordán, Antonio; Fleskens, Luuk; van der Ploeg, Martine; Muñoz-Rojas, Miriam; Anaya-Romero, María; van der Salm, Renée J.; De la Rosa, Diego

    2015-04-01

    Agricultural land suitability analysis and improvement of soils by addressing major limitations may be a strategy for climate change adaptation. This study aims to investigate the influence of topography and variability of soil factors on the suitability of 12 annual, semiannual and perennial Mediterranean crops in the province of Seville (southern Spain). In order to represent the variability in elevation, lithology and soil, two latitudinal and longitudinal (S-N and W-E) soil transects (TA and TB) were considered including 63 representative points at regular 4 km intervals. These points were represented by 41 soil profiles from the SDBm soil database -Seville. Almagra model, a component of the agro-ecological decision support system MicroLEIS, was used to assess soil suitability. Results were grouped into five soil suitability classes: S1-optimum, S2-high, S3-moderate, S4-marginal and S5-not suitable. Each class was divided in subclasses according to the main soil limiting factors: depth (p), texture (t), drainage (d), carbonate content (c), salinity (s), sodium saturation (a), and the degree of development of the soil profile (g). This research also aimed to maximize soil potential by improving limiting factors d, c, s and a after soil restoration. Therefore, management techniques were also considered as possible scenarios in this study. The results of the evaluation showed that soil suitability ranged between S1 and S5p - S5s along of the transects. In the northern extreme of transect TA, high content of gravels and coarse texture are limiting factors (soils are classified as S4t) In contrast, the limiting factor in the eastern extreme of transect TB is the shallow useful depth (S5p subclass). The absence of calcium carbonate becomes a limiting factor in some parts of TA. In contrast, the excessive content of calcium carbonate appeared to be a limiting factor for crops in some intermediate points of TB transect. For both transects, soil salinity is the main

  13. Solid waste management practices in wet coffee processing industries of Gidabo watershed, Ethiopia.

    Science.gov (United States)

    Ulsido, Mihret D; Li, Meng

    2016-07-01

    The financial and social contributions of coffee processing industries within most coffee export-based national economies like Ethiopia are generally high. The type and amount of waste produced and the waste management options adopted by these industries can have negative effects on the environment. This study investigated the solid waste management options adopted in wet coffee processing industries in the Gidabo watershed of Ethiopia. A field observation and assessment were made to identify whether the operational characteristics of the industries have any effect on the waste management options that were practiced. The investigation was conducted on 125 wet coffee processing industries about their solid waste handling techniques. Focus group discussion, structured questionnaires, key informant interview and transect walks are some of the tools employed during the investigation. Two major types of wastes, namely hull-bean-pulp blended solid waste and wastewater rich in dissolved and suspended solids were generated in the industries. Wet mills, on average, released 20.69% green coffee bean, 18.58% water and 60.74% pulp by weight. Even though these wastes are rich in organic matter and recyclables; the most favoured solid waste management options in the watershed were disposal (50.4%) and industrial or household composting (49.6%). Laxity and impulsive decision are the driving motives behind solid waste management in Gidabo watershed. Therefore, to reduce possible contamination of the environment, wastes generated during the processing of red coffee cherries, such as coffee wet mill solid wastes, should be handled properly and effectively through maximisation of their benefits with minimised losses.

  14. Structure of Wet Specimens in Electron Microscopy

    Science.gov (United States)

    Parsons, D. F.

    1974-01-01

    Discussed are past work and recent advances in the use of electron microscopes for viewing structures immersed in gas and liquid. Improved environmental chambers make it possible to examine wet specimens easily. (Author/RH)

  15. National Ignition Facility wet weather construction plan

    Energy Technology Data Exchange (ETDEWEB)

    Kugler, A N

    1998-01-01

    This report presents a wet weather construction plan for the National Ignition Facility (NIF) construction project. Construction of the NIF commenced in mid- 1997, and excavation of the site was completed in the fall. Preparations for placing concrete foundations began in the fall, and above normal rainfall is expected over the tinter. Heavy rainfall in late November impacted foundation construction, and a wet weather construction plan was determined to be needed. This wet weather constiction plan recommends a strategy, techniques and management practices to prepare and protect the site corn wet weather effects and allow construction work to proceed. It is intended that information in this plan be incorporated in the Stormwater Pollution Prevention Plan (SWPPP) as warranted.

  16. ROE Wet Sulfate Deposition 2009-2011

    Data.gov (United States)

    U.S. Environmental Protection Agency — The raster data represent the amount of wet sulfate deposition in kilograms per hectare from 2009 to 2011. Summary data in this indicator were provided by EPA’s...

  17. ROE Wet Nitrate Deposition 1989-1991

    Data.gov (United States)

    U.S. Environmental Protection Agency — The raster data represent the amount of wet nitrate deposition in kilograms per hectare from 1989 to 1991. Summary data in this indicator were provided by EPA’s...

  18. ROE Wet Nitrate Deposition 2011-2013

    Data.gov (United States)

    U.S. Environmental Protection Agency — The raster data represent the amount of wet nitrate deposition in kilograms per hectare from 2011 to 2013. Summary data in this indicator were provided by EPA’s...

  19. Wet granular matter a truly complex fluid

    CERN Document Server

    Herminghaus, Stephan

    2013-01-01

    This is a monograph written for the young and advanced researcher who is entering the field of wet granular matter and keen to understand the basic physical principles governing this state of soft matter. It treats wet granulates as an instance of a ternary system, consisting of the grains, a primary, and a secondary fluid. After addressing wetting phenomena in general and outlining the basic facts on dry granular systems, a chapter on basic mechanisms and their effects is dedicated to every region of the ternary phase diagram. Effects of grain shape and roughness are considered as well. Rather than addressing engineering aspects such as existing books on this topic do, the book aims to provide a generalized framework suitable for those who want to understand these systems on a more fundamental basis. Readership: For the young and advanced researcher entering the field of wet granular matter.

  20. Tualatin River - Wet Prairie Restoration Phase III

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Forty five acres of wet prairie and 11 acres of adjacent lands were treated for reed canarygrass in this ongoing project. Federally threatened Nelson’s...

  1. Structure of Wet Specimens in Electron Microscopy

    Science.gov (United States)

    Parsons, D. F.

    1974-01-01

    Discussed are past work and recent advances in the use of electron microscopes for viewing structures immersed in gas and liquid. Improved environmental chambers make it possible to examine wet specimens easily. (Author/RH)

  2. Critical point wetting drop tower experiment

    Science.gov (United States)

    Kaukler, W. F.; Tcherneshoff, L. M.; Straits, S. R.

    1984-01-01

    Preliminary results for the Critical Point Wetting CPW Drop Tower Experiment are produced with immiscible systems. Much of the observed phenomena conformed to the anticipated behavior. More drops will be needed to test the CPW theory with these immiscible systems.

  3. Wetting behavior of alternative solder alloys

    Energy Technology Data Exchange (ETDEWEB)

    Hosking, F.M.; Vianco, P.T.; Hernandez, C.L.; Rejent, J.A.

    1993-07-01

    Recent economic and environmental issues have stimulated interest in solder alloys other than the traditional Sn-Pb eutectic or near eutectic composition. Preliminary evaluations suggest that several of these alloys approach the baseline properties (wetting, mechanical, thermal, and electrical) of the Sn-Pb solders. Final alloy acceptance will require major revisions to existing industrial and military soldering specifications. Bulk alloy and solder joint properties are consequently being investigated to validate their producibility and reliability. The work reported in this paper examines the wetting behavior of several of the more promising commercial alloys on copper substrates. Solder wettability was determined by the meniscometer and wetting balance techniques. The wetting results suggest that several of the alternative solders would satisfy pretinning and surface mount soldering applications. Their use on plated through hole technology might be more difficult since the alloys generally did not spread or flow as well as the 60Sn-40Pb solder.

  4. Adult Bed-Wetting: A Concern?

    Science.gov (United States)

    ... D. Bed-wetting that starts in adulthood (secondary enuresis) is uncommon and requires medical evaluation. Causes of ... Erik P. Castle, M.D. References Adult nocturnal enuresis. National Association for Continence. http://www.nafc.org/ ...

  5. A WET TALE: TOXICITY OF COMPLEX EFFLUENTS

    Science.gov (United States)

    This course covers standards, regulations, policy, guidance and technical aspects of implementing the whole effluent toxicity program. The curriculum incorporates rationale and information on WET test requirements from USEPA documents, such as the Technical Support Document for W...

  6. Documenting the Distribution and Sedimentology of the Penultimate Tsunami Along a Cross Island Transect on Koh Phra Thong Island, Thailand

    Science.gov (United States)

    Kirby, M. E.; Rhodes, B. P.; Leeper, R. J.; Choowong, M.

    2013-12-01

    Thailand's Koh Phra Thong Island is characterized by ridge-swale topography. Unlike the ridges, swales often hold water during the wet season, which allows for the deposition and preservation of sediment. As a result, swales are potential archives for past tsunami deposits. Seven different swale sites along a 1.9 km transect on the northern half of the island were trenched to investigate the occurrence and distribution of paleo-tsunami deposits. Duplicate overlapping slab cores were taken from the trench walls. Cores from sites F111, F511, F611, and F811 were analyzed at 1 cm contiguous intervals for magnetic susceptibility, percent organic matter, percent total carbonate, and grain size. Each site contained at least one distinct penultimate tsunami (PT) unit. Although the quality of preservation of the PT sediment unit diminishes with distance from the modern shoreline, presumably caused by differential bioturbation, grain size distributions and organic matter content clearly demarcate each PT unit. Notably, the distribution of sand sizes throughout the PT is not the same landward. More distal sites (F611 and F811) are dominated by very fine to fine sands; whereas, the mid island site (F511) is sand and coarse sand dominated. Microscopic charcoal was picked under a binocular scope to bracket the PT unit. A maximum age of 620 cy BP was obtained for the most distal site (F811). Ages spanning 740 - 900 cy BP provide a maximum age for the PT unit at F511. Ages for the PT unit from near the present day shoreline are similar (550 - 770 cy BP: Jankaew et al., 2008) using radiocarbon methods. OSL dates from the PT unit sands show an age 380×50 years before AD 1950 (Prendergast et al., 2012). From these various ages, the PT unit was deposited no earlier than 900 cy BP but likely no later than 380×50 years before AD 1950.

  7. G-CSF prevents caspase 3 activation in Schwann cells after sciatic nerve transection, but does not improve nerve regeneration.

    Science.gov (United States)

    Frost, Hanna K; Kodama, Akira; Ekström, Per; Dahlin, Lars B

    2016-10-15

    Exogenous granulocyte-colony stimulating factor (G-CSF) has emerged as a drug candidate for improving the outcome after peripheral nerve injuries. We raised the question if exogenous G-CSF can improve nerve regeneration following a clinically relevant model - nerve transection and repair - in healthy and diabetic rats. In short-term experiments, distance of axonal regeneration and extent of injury-induced Schwann cell death was quantified by staining for neurofilaments and cleaved caspase 3, respectively, seven days after repair. There was no difference in axonal outgrowth between G-CSF-treated and non-treated rats, regardless if healthy Wistar or diabetic Goto-Kakizaki (GK) rats were examined. However, G-CSF treatment caused a significant 13% decrease of cleaved caspase 3-positive Schwann cells at the lesion site in healthy rats, but only a trend in diabetic rats. In the distal nerve segments of healthy rats a similar trend was observed. In long-term experiments of healthy rats, regeneration outcome was evaluated at 90days after repair by presence of neurofilaments, wet weight of gastrocnemius muscle, and perception of touch (von Frey monofilament testing weekly). The presence of neurofilaments distal to the suture line was similar in G-CSF-treated and non-treated rats. The weight ratio of ipsi-over contralateral gastrocnemius muscles, and perception of touch at any time point, were likewise not affected by G-CSF treatment. In addition, the inflammatory response in short- and long-term experiments was studied by analyzing ED1 stainable macrophages in healthy rats, but in neither case was any attenuation seen at the injury site or distal to it. G-CSF can prevent caspase 3 activation in Schwann cells in the short-term, but does not detectably affect the inflammatory response, nor improve early or late axonal outgrowth or functional recovery.

  8. Altered prosaposin expression in the rat facial nerve nucleus following facial nerve transection and repair

    Institute of Scientific and Technical Information of China (English)

    Dong Wang; Wenlong Luo; Cuiying Zhou; Jingjing Li

    2009-01-01

    BACKGROUND: Studies have demonstrated that damaged facial nerves synthesize prosaposin to promote repair of facial neurons.OBJECTIVE: To observe time-course changes of prosaposin expression in the facial nerve nucleus of Sprague Dawley rats following facial nerve transection and repair.DESIGN, TIME AND SETTING: A randomized control neuropathological animal experiment was performed in Chongqing Medical University between March 2007 and September 2008.MATERIALS: A total of 48 adult, male, Sprague Dawley rats were selected and randomly divided into transection and transection + end-to-end anastomosis groups (n =24). Rabbit anti-rat prosaposin antibody, instant SABC immunohistochemical kit, and antibody dilution solution were purchased from Wuhan Uscn Science Co., Ltd., China.METHODS: In the transection group, the nerve trunk of the distal retroauricular branch of the left facial nerves was ligated in Sprague Dawley rats, and a 5-mm nerve trunk at the distal end of the ligation site was removed. In the transection + end-to-end anastomosis group, epineurial anastomosis was performed immediately following transection of the left facial nerves. The right facial nerves in the two groups sewed as the normal control group.MAIN OUTCOME MEASURES: The number of prosaposin-positive neurons, as well as intensity of immunostaining in facial nerve nucleus, following transection and end-to-end anastomosis were determined by immunohistochemistry at 1,3, 7, 14, 21, and 35 days after injury.RESULTS: Transection group: transection of facial nerves resulted in increased number of prosaposin-positive neurons and immunoreactivity intensity in the facial nucleus on day 1. These values significantly increased by day 3. Expression was greater than in the control side. The peak of the reduction was reached at 7 days post-surgery. Transection + end-to-end anastomosis group: the number of prosaposin-positive neurons and immunoreactivity intensity was reduced in the facial nerve nucleus following

  9. Wetting and phase separation at surfaces

    Indian Academy of Sciences (India)

    Sanjay Puri; Kurt Binder

    2005-06-01

    We study the problem of surface-directed spinodal decomposition, viz., the dynamical interplay of wetting and phase separation at surfaces. In particular, we focus on the kinetics of wetting-layer growth in a semi-infinite geometry for arbitrary surface potentials and mixture compositions. We also present representative results for phase separation in confined geometries, e.g., cylindrical pores, thin films, etc.

  10. Biodegradation of wet-white leather

    OpenAIRE

    Ollé Otero, Lluís; Jorba Rafart, Montse; Font Vallès, Joaquim; Shendrik, Alexander; Bacardit Dalmases, Anna

    2011-01-01

    This paper deals with the study of the physical, chemical and biological processes associated with the deterioration of wet-white leather. The samples of leather were exposed for eight months to outdoor weathering and then their properties were subsequently evaluated. The results indicate that resistance and dimensional stability of wet-white (THPS-syntan) leather is higher than that of chrometanned leather. The comparative work with chrome leather was described earlier.

  11. Improvement of Heating Method for Measuring the Wetness of Flowing Wet Steam

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    In this paper,an improvement of heating method for measuring wetness of the flowing wet steam is developed,the basic principle of the heating method is presented and the mathematical model has been built for analyzing the thermodynamics problems during the process of heating,Moreover,an instrument for measuring wetness of wet steam flow was designed and made out.This instument has been used for measuring wetness of the wet steam flow at the outlet of the nozzle rig in Thermal Turbine Laboratory,Xi'an Jiaotong University,By analyzing the relative error of the result,it was found that this instrument has fairly high accuracy,it can be used as the prototype of practical instrument and has an important applicable value in engineering.

  12. Nonparametric estimation of population density for line transect sampling using FOURIER series

    Science.gov (United States)

    Crain, B.R.; Burnham, K.P.; Anderson, D.R.; Lake, J.L.

    1979-01-01

    A nonparametric, robust density estimation method is explored for the analysis of right-angle distances from a transect line to the objects sighted. The method is based on the FOURIER series expansion of a probability density function over an interval. With only mild assumptions, a general population density estimator of wide applicability is obtained.

  13. Ground Validation Transects (2012) in the U.S. Virgin Islands

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This shapefile denotes the location of underwater photos and video transects taken between 10/23-10/31/12 in Fish Bay and Coral Bay, St. John and the St. Thomas East...

  14. Robust upregulation of serotonin 2A receptors after chronic spinal transection of rats: An immunohistochemical study

    DEFF Research Database (Denmark)

    Kong, Xiang-Yu; Wienecke, Jacob; Hultborn, Hans;

    2010-01-01

    It is well known that spinal motoneurons below a spinal transection become supersensitive to a systemic administration of serotonin (5-HT) precursors, such as 5-hydroxytryptophan. This supersensitivity has been implicated in both the process of functional recovery following chronic lesions, and a...

  15. Reinnervation of muscles after transection of the sciatic nerve in adult rats

    NARCIS (Netherlands)

    Ijkema-Paassen, J; Meek, MF; Gramsbergen, A

    2002-01-01

    Functional recovery after transection of the sciatic nerve in adult rats is poor, probably because of abnormalities in reinnervation. Denervation and reinnervation patterns were studied morphologically in the lateral gastrocnemius (LGC), tibialis anterior (TA), and soleus (SOL) muscles for 21 weeks

  16. Pedological Characterisation of Sites Along a Transect from a Primary Cadmium/ Lead/ Zinc Smelting Works

    NARCIS (Netherlands)

    Filzek, P.D.B.; Spurgeon, D.J.; Broll, G.E.; Svendsen, C.; Hankard, P.K.; Kammenga, J.E.; Donker, M.H.; Weeks, J.M.

    2004-01-01

    A pedological characterisation of seven sites along a transect from a smelter at Avonmouth, UK, was undertaken. Site locations comprised a mixture of both grassland (5 sites) and oak tree dominated (2 sites) areas. Geographically, sites were either low lying or on adjacent elevated ground. Across th

  17. Fimbria-fornix (FF)-transected hippocampal extracts induce the activation of astrocytes in vitro.

    Science.gov (United States)

    Zou, Linqing; Li, Haoming; Jin, Guohua; Tian, Meiling; Qin, Jianbing; Zhao, Heyan

    2014-03-01

    Hippocampus is one of the neurogenesis areas in adult mammals, but the function of astrocytes in this area is still less known. In our previous study, the fimbria-fornix (FF)-transected hippocampal extracts promoted the proliferation and neuronal differentiation of radial glial cells in vitro. To explore the effects of hippocampal extracts on gliogenesis, the hippocampal astrocytes were treated by normal or ff-transected hippocampal extracts in vitro. The cells were immunostained by brain lipid-binding protein (BLBP), nestin, and SOX2 to assess their state of activation. The effects of astrocyte-conditioned medium on the neuronal differentiation of hippocampal neural stem cells (NSCs) were also investigated. After treatment of FF-transected hippocampal extracts, the number of BLBP, nestin, and Sox-positive cells were obviously more than the cells which treated by normal hippocampal extracts, these cells maintained a state of activation and the activated astrocyte-conditioned medium also promoted the differentiation of NSCs into more neurons. These findings suggest that the astrocytes can be activated by FF-transected hippocampal extracts and these activated cells also can promote the neuronal differentiation of hippocampal NSCs in vitro.

  18. Microstructure measurements along a quasi-meridional transect in the northeastern Atlantic Ocean

    NARCIS (Netherlands)

    Jurado, E.; van der Woerd, H.J.; Dijkstra, H.A.

    2012-01-01

    This study presents vertical profiles of turbulence parameters obtained in the upper 100 m of the northeastern Atlantic Ocean along a transect from tropical permanently stratified waters to subpolar seasonally stratified waters in July–August 2009. The focus is to fully characterize the vertical mix

  19. Q value structure of geoscience transect from Korla to Jimsar and its geodynamic implication

    Institute of Scientific and Technical Information of China (English)

    赵俊猛; 樊吉昌; 李植纯

    2003-01-01

    In this paper, the methods for Q value inversion in 2-D lateral inhomogeneous medium have been introduced. The 2-D Q value inversion has been conducted using seismic wide-angle reflection/refraction data of the profile from Korla to Jimsar. The result shows that the 2-D Q value structure of the transect from Korla to Jimsar is characterized by vertical stratifying and lateral zoning. Vertically, the crust can be divided into upper crust, middle crust and lower crust with the Q value increasing downwards. Horizontally, the total transect can be classified as three regions--the northern margin of the Tarim Basin, the Tianshan orogenic belt (TOB) and the southern margin of the Junggar Basin. At the northern margin of the Tarim Basin the Q value increases northwards, indicating a northward subduction of the Tarim Basin (TB) into the TOB. The Q value within the TOB jumps near Kumux, making a stage-like difference in Q value. The Q value distribution at the southern margin of the JB suggests a southward subduction of the Junggar Basin (JB) into the TOB.The double subduction pattern of the TB and JB into the TOB revealed by the transect from Korla to Jimsar has a big difference from the model " lithospheric subduction with intrusion of the layers into the crust" developed according to the results of the geoscience transect from Xayar to Burjing. The differences between the two provide some dynamic evidence at lithospheric scale for the segmentation of the TOB.

  20. Relative spatial soil geochemical variability along two transects across the United States and Canada

    Science.gov (United States)

    Garrett, Robert G.

    2009-01-01

    To support the development of protocols for the proposed North American Soil Geochemical Landscapes project, whose objective is to establish baselines for the geochemistry of North American soils, two continental-scale transects across the United States and Canada were sampled in 2004. The sampling employed a spatially stratified random sampling design in order to estimate the variability between 40-km linear sampling units, within them, at sample sites, and due to sample preparation and analytical chemical procedures. The 40-km scale was chosen to be consistent with the density proposed for the continental-scale project. The two transects, north–south (N–S) from northern Manitoba to the USA–Mexico border near El Paso, Texas, and east–west (E–W) from the Virginia shore north of Washington, DC, to north of San Francisco, California, closely following the 38th parallel, have been studied individually. The purpose of this study was to determine if statistically significant systematic spatial variation occurred along the transects. Data for 38 major, minor and trace elements in A- and C-horizon soils where less than 5% of the data were below the detection limit were investigated by Analysis of Variance (ANOVA). A total of 15 elements (K, Na, As, Ba, Be, Ce, La, Mn, Nb, P, Rb, Sb, Th, Tl and W) demonstrated statistically significant (p<0.05) variability at the between-40-km scale for both horizons along both transects. Only Cu failed to demonstrate significant variability at the between-40-km scale for both soil horizons along both transects.

  1. The transect method: a novel approach to on-farm welfare assessment of commercial turkeys.

    Science.gov (United States)

    Marchewka, Joanna; Estevez, Inma; Vezzoli, Giuseppe; Ferrante, Valentina; Makagon, Maja M

    2015-01-01

    Currently, no animal-based protocol for on-farm welfare assessment of commercial turkeys is available. The birds' size and flighty nature make obtaining a representative sample using traditional methods difficult. The transect walks (TW) approach provides a potential alternative for on-farm assessments of turkey welfare. We compared the TW approach with a traditional method, and data collected as the birds were moved out of the house during the load out process (L). Ten commercial 19- to 20-week-old Hybrid turkey flocks were evaluated (1 flock/house/farm). Half of the flocks were housed on farms deemed as "faring well" by the company, the other half were on "suboptimal" farms. Each house was subdivided longitudinally into 4 transects. Two observers walked the transects in random order, recording the total number of birds per transect that were immobile; lame; aggressive towards a mate; interacting with humans; with visible head, vent, or back wounds; engaging in mounting behaviors; small; featherless; dirty; sick; terminal; or dead. Flocks were re-evaluated on the same day using the individual sampling method (S), where randomly selected birds were scored as they took 10 steps. Flocks were re-assessed within 48 h of the transect evaluation, as birds were funneled out of the house during load out. Using ANOVAs we determined the effects of observers, method, management, and their interactions on proportions of turkeys per house within each category. Outcome parameters were not affected by management (P>0.05 for all) or observer (P>0.05 for most), but an assessment method effect was detected (Passessment as it produced results similar to those obtained at L when all birds could be scored individually.

  2. Delay of skeletal muscle atrophy after transplantation of mesenchymal progenitor cells into transected position%神经断离处移植间充质祖细胞延缓骨骼肌萎缩

    Institute of Scientific and Technical Information of China (English)

    赵文勇; 万立华; 粟永萍; 冉新泽

    2013-01-01

    目的 探讨间充质祖细胞(MPC)移植于神经断离处延缓失神经性骨骼肌萎缩.方法 取GFP转基因C57小鼠后肢长骨进行MPC培养及鉴定.选取C57小鼠36只,随机分为MPC移植组、神经断离组及对照组,MPC移植组坐骨神经断离处注入5 μL MPC悬液,神经断离组注入等量PBS,对照组不作处理.观察小鼠后肢活动能力,术后2和4周测量腓肠肌湿重、肌纤维横截面积维持率及观察超微结构,用Western blot检测α-actin、MHC及RT-PCR检测Myogenin、MyoD的表达.结果 术后2和4周,MPC移植组腓肠肌湿重及肌纤维横截面积维持率显著高于神经断离组(P<0.05);术后4周,MPC移植组肌细胞核、线粒体、内质网的退变及肌肉纤维化程度明显低于神经断离组,α-actin、MHC、Myogenin、MyoD表达强度显著高于神经断离组(P<0.05).结论 异体间充质祖细胞体内移植可有效延缓失神经肌肉萎缩.%Objective To study the delaying denervated skeletal muscle atrophy after transplantation of mesenchymal progenitor cells(MPCs) into the transected position.Methods MPCs were isolated from bones of hind limbs of GFP transgenic C57 mice for cultivation and identification.36 C57 mice were divided into 3 groups evenly in random,MPC transplantation group,the transected group and the control group.5 μL of MPC suspension and 5 μL of Phosphate buffered saline (PBS) were injected into the sciatic nerve transected position in the MPC transplantation group and the transected group respectively while nothing was injected in the control group.The activity ability of hind limbs of mice were observed.At the time point of 2 and 4 weeks after the operation,the retain ratio of wet weight of gastrocnemius muscle and cross sectional area of muscle fiber was measured and the ultrastructural organization was observed.The expression of α-actin,myoglobulin (MHC) were detected by Western blot and the expression of Myogenin and MyoD were detected by RT

  3. Epimacular brachytherapy for wet AMD: current perspectives.

    Science.gov (United States)

    Casaroli-Marano, Ricardo P; Alforja, Socorro; Giralt, Joan; Farah, Michel E

    2014-01-01

    Age-related macular degeneration (AMD) is considered the most common cause of blindness in the over-60 age group in developed countries. There are basically two forms of presentation: geographic (dry or atrophic) and wet (neovascular or exudative). Geographic atrophy accounts for approximately 85%-90% of ophthalmic frames and leads to a progressive degeneration of the retinal pigment epithelium and the photoreceptors. Wet AMD causes the highest percentage of central vision loss secondary to disease. This neovascular form involves an angiogenic process in which newly formed choroidal vessels invade the macular area. Today, intravitreal anti-angiogenic drugs attempt to block the angiogenic events and represent a major advance in the treatment of wet AMD. Currently, combination therapy for wet AMD includes different forms of radiation delivery. Epimacular brachytherapy (EMBT) seems to be a useful approach to be associated with current anti-vascular endothelial growth factor agents, presenting an acceptable efficacy and safety profile. However, at the present stage of research, the results of the clinical trials carried out to date are insufficient to justify extending routine use of EMBT for the treatment of wet AMD.

  4. Performance of some surfactants as wetting agents

    Energy Technology Data Exchange (ETDEWEB)

    Shalaby, M.N.; El-Shanny, O.A.A. [Egyptian Petroleum Research Institute (EPRI), Cairo (Egypt). Evaluation and Analysis Dept.

    2005-12-01

    The wetting power of anionic surfactant: sodium dodecyl sulfate (SDS), and nonionic surfactants: polyoxyethelene(14)monolaurate [La(EO){sub 14}] and polyoxyethelene(14)monoeleate [OI(EO){sub 14}] has been studied to determine their performance as wetting agents. The study reveals that the nonionic compound with a long hydrophobic chain exhibits higher wettability than the shorter one when used at very low cocentrations (below CMC) and the reverse is shown with high concentrations (above CMC). the wetting power of the investigated surfactants increases as the CMC values increases. In case of the nonionic compounds and at surfactant concentrations equal their CMC values, OI(EO){sub 14} shows a higher wetting power than La(EO){sub 14} while is possesses a lower HLB value. The anionic surfactant shows an optimum wetting in comparison with the tested nonionic one. The wettability of all the investigated samples increases as the surface tension of their solutions increases to the allowed limit that can be reached in the presence of surfactant. (orig.)

  5. Membrane-based wet electrostatic precipitation.

    Science.gov (United States)

    Bayless, David J; Shi, Liming; Kremer, Gregory; Stuart, Ben J; Reynolds, James; Caine, John

    2005-06-01

    Emissions of fine particulate matter, PM2.5, in both primary and secondary form, are difficult to capture in typical dry electrostatic precipitators (ESPs). Wet (or water-based) ESPs are well suited for collection of acid aerosols and fine particulates because of greater corona power and virtually no re-entrainment. However, field disruptions because of spraying (misting) of water, formation of dry spots (channeling), and collector surface corrosion limit the applicability of current wet ESPs in the control of secondary PM2.5. Researchers at Ohio University have patented novel membrane collection surfaces to address these problems. Water-based cleaning in membrane collectors made of corrosion-resistant fibers is facilitated by capillary action between the fibers, maintaining an even distribution of water. This paper presents collection efficiency results of lab-scale and pilot-scale testing at FirstEnergy's Bruce Mansfield Plant for the membrane-based wet ESP. The data indicate that a membrane wet ESP was more effective at collecting fine particulates, acid aerosols, and oxidized mercury than the metal-plate wet ESP, even with approximately 15% less collecting area.

  6. Energy and heat balance in wet DCT

    Energy Technology Data Exchange (ETDEWEB)

    Saxena, Viren; Moser, Alexander; Schaefer, Michael; Ritschel, Michael [BorgWarner Drivetrain Engineering GmbH, Ketsch (Germany)

    2012-11-01

    Wet clutch systems are well known for their thermal robustness and versatility in a wide range of automotive applications. Conventional automatics have used them for a long time as torque converter lock-up clutches, shift elements and launch clutches. With the development of DCTs, wet clutch technology has evolved in terms of launch and shift performance, controllability, robustness and efficiency. This paper discusses improvements in the wet clutch and their impact on today's vehicle applications in terms of heat and energy management. Thermal robustness is a crucial aspect for an automatic transmission. In addition to the clutch thermal performance, the influence of transmission oil cooler and oil sump warm-up behavior are discussed. Based on our latest development activities, test results and simulations, we shall discuss the latest friction material enhancement and its impact on DCTs in terms of efficiency and performance. Drag loss is a much-discussed topic during the development of wet clutch systems. This paper discusses in detail the cause and break-up of various energy losses in a wet DCT. Efficient energy management strategies for actuation systems, cooling, and lubrication, clutch apply, and pre-selection in modern power trains with engine start / stop are evaluated based on the latest test and simulation results. Finally, the paper summarizes the performance and efficiency optimized moist clutch system. (orig.)

  7. Wetting and adsorption modification in the system

    Directory of Open Access Journals (Sweden)

    Yuliya Bogdanova

    2015-09-01

    Full Text Available Regularities of wetting and adsorption modification of surfaces of continual membranes made from highly permeable glassy polymers poly[1-(trimethylsilyl-1-propyne] (PTMSP and poly(4-methyl-2-pentyn (PMP with aqueous ethanol solutions and alcohol solutions containing organic dyes (Solvent Blue 35 and Remazol Brilliant Blue were investigated. Isotherms of stress wetting of polymer membrane surface by etanol solutions were found out to have maximums in the range of concentrations corresponding to the beginning of liquid sorption into the membrane and polymer swelling. Thus, the principal possibility of optimization of nanofiltration experiments by liquid wetting angle measurements on continuous polymer membrane surfaces was shown. The presence of the dye was shown not to affect PMP wetting. But in the case of PTMSP, it leads to shear of the maximum of stress wetting isotherms to the range of higher concentrations. It was found out the effectiveness of the adsorption surface modification of continuous polymer membrane surfaces by ethanol solutions containing dyes does not dependent on chemical nature of the dye. At the same time, there are different trends in the energy characteristics of the membrane surface.

  8. WET STRENGTH PAPER REPULPING:LABORATORY EVALUATION

    Institute of Scientific and Technical Information of China (English)

    Nishi K. Bhardwaj; Vikas Rajan; A.G. Kulkarni

    2004-01-01

    The recycling of wet strength papers in a normal recycling mill is often troublesome due to the severe operating conditions required to defibre wet strength papers. The various methods are presented which will quickly allow mills to determine the most effective pulping aids to use when repulping wet strength papers. The repulping of wet strength paper with inorganic chemicals was investigated in the laboratory. The effects of major variables, that is,repulping time, pulp consistency, soaking time,temperature, and reactant concentration in the repulping stage were examined using Plackett-Burman design. The repulping time was the most crucial & influential process variable affecting repulping characteristic and formation related properties. The more significant repulping process variables affecting pulp yield were repulping time,soaking temperature and pulp consistency whereas for formation index and feature size, repulping time,pulp consistency, soaking temperature and time were the more important variables. The formation index is increased by an increase in repulping time, pulp consistency and soaking time whereas the feature size is decreased by an increase in repulping time,soaking temperature and pulp consistency. The formation index and the rejects were more sensitive to changes in process variables than were the feature size or the pulp yield. The pulp recycled from wet strength waste paper had good physical strength properties.

  9. Tunable Reactive Wetting of Sn on Microporous Cu Layer

    Institute of Scientific and Technical Information of China (English)

    Qingquan Lai; Lei Zhang; Cai Chen; J.K. Shang

    2012-01-01

    Wetting of microporous Cu layer by liquid Sn resulted in contact angles from 0 to 33 deg., tunable by varying wetting temperature and porous microstructure. The wetting was dominated by the interracial metallurgical reaction, which can lead to pore closure phenomenon, as the liquid infiltration facilitating the wetting process.

  10. Evaporation from rain-wetted forest in relation to canopy wetness, canopy cover, and net radiation

    NARCIS (Netherlands)

    Klaassen, W.

    2001-01-01

    Evaporation from wet canopies is commonly calculated using E-PM, the Penman-Monteith equation with zero surface resistance. However, several observations show a lower evaporation from rain-wetted forest. Possible causes for the difference between E-PM and experiments are evaluated to provide rules f

  11. Advanced methods for the treatment of organic aqueous wastes: wet air oxidation and wet peroxide oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Debellefontaine, Hubert; Chakchouk, Mehrez; Foussard, Jean Noel [Institut National des Sciences Appliquees (INSA), 31 - Toulouse (France). Dept. de Genie des Procedes Industriels; Tissot, Daniel; Striolo, Phillipe [IDE Environnement S.A., Toulouse (France)

    1993-12-31

    There is a growing concern about the problems of wastes elimination. Various oxidation techniques are suited for elimination of organic aqueous wastes, however, because of the environmental drawbacks of incineration, liquid phase oxidation should be preferred. `Wet Air Oxidation` and `Wet Peroxide Oxidation`are alternative processes which are discussed in this paper. 17 refs., 13 figs., 4 tabs.

  12. Evaporation from rain-wetted forest in relation to canopy wetness, canopy cover, and net radiation

    NARCIS (Netherlands)

    Klaassen, W.

    2001-01-01

    Evaporation from wet canopies is commonly calculated using E-PM, the Penman-Monteith equation with zero surface resistance. However, several observations show a lower evaporation from rain-wetted forest. Possible causes for the difference between E-PM and experiments are evaluated to provide rules

  13. Experimental investigation of the link between static and dynamic wetting by forced wetting of nylon filament.

    Science.gov (United States)

    Vega, M J; Gouttière, C; Seveno, D; Blake, T D; Voué, M; De Coninck, J; Clarke, A

    2007-10-09

    Forced wetting experiments with various liquids were conducted to study the dynamic wetting properties of nylon filament. The molecular-kinetic theory of wetting (MKT) was used to interpret the dynamic contact angle data and evaluate the contact-line friction zeta0 at the microscopic scale. By taking account of the viscosity of the liquid, zeta0 could be related exponentially to the reversible work of adhesion. This clearly establishes an experimental link between the static and dynamic wetting properties of the material. Moreover, statistical analysis of the equilibrium molecular displacement frequency K0 and the length of the displacements lambda reveals that these two fundamental parameters of the MKT are strongly correlated, not only in the linearized form of the theory (valid close to equilibrium) but also when the nonlinear form of the equations has to be considered at higher wetting speeds.

  14. Using wet FGD systems to absorb mercury

    Energy Technology Data Exchange (ETDEWEB)

    Renninger, S.A.; Farthing, G.A.; Ghorishi, S.B. (and others) [Babcock and Wilcox Co. (US)

    2004-10-01

    For the past 12 years, the Babcock and Wilcox Company has been striving to develop mercury-reduction techniques that utilize, whenever possible, existing plant pollution control devices. This article discusses one such technique, which has demonstrated the potential for removing more than 95% of oxidized mercury in a wet flue gas desulfurization system at a low incremental cost and with little or no impact on the system's operation or SO{sub 2} removal performance. B & W's techniques enhance the mercury control ability of wet FGD systems using sodium hydrosulfide injection. This has been tested in a combined air quality control system at Mt. Storm Power Station in West Virginia comprising an SCR system and ESP with a wet FGD system. 6 figs.

  15. Molecular Dynamics Simulations for Predicting Surface Wetting

    Directory of Open Access Journals (Sweden)

    Jing Chen

    2014-06-01

    Full Text Available The investigation of wetting of a solid surface by a liquid provides important insights; the contact angle of a liquid droplet on a surface provides a quantitative measurement of this interaction and the degree of attraction or repulsion of that liquid type by the solid surface. Molecular dynamics (MD simulations are a useful way to examine the behavior of liquids on solid surfaces on a nanometer scale. Thus, we surveyed the state of this field, beginning with the fundamentals of wetting calculations to an examination of the different MD methodologies used. We highlighted some of the advantages and disadvantages of the simulations, and look to the future of computer modeling to understand wetting and other liquid-solid interaction phenomena.

  16. Handling of wet residues in industry

    DEFF Research Database (Denmark)

    Villanueva, Alejandro

    In countries with high prices of fresh water use and wastewater discharge, water recycling has become an alternative to traditional water consumption and discharge for industries with water-based processes. Industrial water recycling means in many cases that water has to be treated and cleaned......, to remove from it the substances which presence impedes reusing the water. These substances accumulate in a by-product called wet residue. An integral part of water recycling projects in the industry is the handling and disposal of the wet residues generated. The treatment, utilisation and disposal of wet...... residues depend totally on the industrial sector of origin and the composition of the water to be recycled. Treatment is more problematic in some cases than in others, but in all water recycling applications it is an issue of concern. The present study addresses this concern by providing a package...

  17. Mechanical Properties of Sheared Wet Granular Piles

    Science.gov (United States)

    Seemann, Ralf; Schaber, Marc; Karmakar, Somnath; Hippler, Anna-Lena; Scheel, Mario; di Michiel, Marco; Brinkmann, Martin

    2015-03-01

    The mechanical properties of dry and wet granulates are explored when being sheared with a parabolic profile at constant shear volume. The dissipated energy increase linearly with external pressure both for a wet and a dry granulate. However, the dissipated energy for wet a granulate has a finite value for the limiting case of vanishing external pressure and increases slower with external pressure compared to the dry granulate. Using a down sized version of the shear cell the reorganization of a granulate and liquid is additionally imaged in real time using x-ray micro-tomography. With the insight from x-ray tomography the contribution of the breaking capillary bridges to the dissipated energy can be analyzed. We could also shed light on the influence of dilatation effects on the dissipated energy upon inverting the shear direction.

  18. NANOFILLERS FOR PAPERMAKING WET END APPLICATIONS

    Directory of Open Access Journals (Sweden)

    Jing Shen

    2010-05-01

    Full Text Available The papermaking industry can benefit a lot from nanotechnology. This versatile technology can also be used in the area of fillers for papermaking wet end applications. In such applications the main technological examples currently available include wet end addition of commercially available nanofillers, formation of nanofiller/fiber or nanofiller/fibril hybrids, development of novel categories of nanofillers such as high aspect ratio nanofillers, and combination of microfillers with nanostructures by specially controlled routes to obtain composite nanofillers. It is worth noting that there are certain challenges associated with nanofillers, such as high cost, difficulty in structure and performance control, poor dispersability and retention, possible severe negative effects on paper strength, possible detrimental interactions between nanofillers with some wet end additives, and the industry-related limitations. However, in the long run, the research and development in the area of nanofillers will surely create many fruitful results.

  19. Divergence of the point tension at wetting

    Science.gov (United States)

    Abraham, D. B.; Latrémolière, F.; Upton, P. J.

    1993-07-01

    To determine the behavior of the line-point tension τ^ at the wetting transition, we consider a two-dimensional Ising model with appropriate boundary conditions and investigate suitable definitions of τ^ associated with the junction of an interface tilted with average angle θc and another lying along the substrate. Size-dependent fluctuations in the point of contact require that τ^ be defined through a convolution sum. Hence τ^~=ln(1/θc) as θc-->0 (wetting transition), which can be understood as a consequence of the entropic repulsion of the tilted part of the interface against the substrate.

  20. Traction of Pneumatic Tires on Wet Runways

    Science.gov (United States)

    Horne, Walter B.; Joyner, Upshur T.

    1965-01-01

    Recent work on the traction of pneumatic tires on wet runways is discussed, and it is shown that a loss of tire traction adversely affects cross-wind landings. The effect of runway surface texture is discussed,, and a simple method for measuring surface texture is described. A preliminary correlation of tire traction with surface texture is shown. Results of work at Langley Research Center on the use of air jets to improve tire traction on wet or flooded runways indicate that this is a promising approach for alleviating the large losses in tire braking and sideways traction that occur when tire hydroplaning occurs on a flooded runway.

  1. Sphere impact and penetration into wet sand

    Science.gov (United States)

    Marston, J. O.; Vakarelski, I. U.; Thoroddsen, S. T.

    2012-08-01

    We present experimental results for the penetration of a solid sphere when released onto wet sand. We show, by measuring the final penetration depth, that the cohesion induced by the water can result in either a deeper or shallower penetration for a given release height compared to dry granular material. Thus the presence of water can either lubricate or stiffen the granular material. By assuming the shear rate is proportional to the impact velocity and using the depth-averaged stopping force in calculating the shear stress, we derive effective viscosities for the wet granular materials.

  2. Sphere impact and penetration into wet sand

    KAUST Repository

    Marston, J. O.

    2012-08-07

    We present experimental results for the penetration of a solid sphere when released onto wet sand. We show, by measuring the final penetration depth, that the cohesion induced by the water can result in either a deeper or shallower penetration for a given release height compared to dry granular material. Thus the presence of water can either lubricate or stiffen the granular material. By assuming the shear rate is proportional to the impact velocity and using the depth-averaged stopping force in calculating the shear stress, we derive effective viscosities for the wet granular materials.

  3. Grain boundary wetness of partially molten dunite

    Science.gov (United States)

    Mu, S.; Faul, U.

    2013-12-01

    The grain scale melt distribution plays a key role for physical properties of partially molten regions in Earth's upper mantle, but our current understanding of the distribution of basaltic melt at the grain scale is still incomplete. A recent experimental study shows that wetted two-grain boundaries are a common feature of partially molten dunite at small melt fractions (Garapic et al., G3, 2013). In early ideal models which assume isotropic surface energy, the grain scale melt distribution is uniquely determined by knowing the melt fraction and the dihedral angle between two crystalline grains and the melt (von Bargen and Waff, JGR, 1986). Olivine is anisotropic in surface energy, hence the grain scale melt distribution at given melt fraction cannot be characterized by the dihedral angle alone. The grain boundary wetness, which is defined as the ratio of solid-liquid boundary area over the total interfacial area (Takei, JGR, 1998), is a more objective measure of the grain scale melt distribution. The aim of this study is to quantify the relationship between grain size, melt fraction, temperature and grain boundary wetness of partially molten dunite under dry conditions. We annealed olivine-basalt aggregates with melt fractions from 0.03% to 6% at a range of temperatures and 1 GPa in a piston cylinder for 1 to 336 hours, with resulting mean grain sizes of 10 to 60 μm. The samples were sectioned, polished and imaged at high resolution by using a field emission SEM. Each image had a size of 2048 x 1536 pixels with a resolution of 0.014 to 0.029 μm/pixel, depending on magnification. For each sample, depending on grain sizes, we made mosaics of 3 x 3 or 6 x 6 overlapping images. Measurements of melt fraction, grain boundary wetness and grain size were carried out on these high resolution mosaics by using ImageJ software. Analyses of mosaics show that grain boundary wetness increases with increasing melt fraction at constant grain size to values well above those

  4. Garmin GPS waypoints delineating low-altitude transects over the Arctic Network of national park units and Selawik National Wildlife Refuge, Alaska, July 2013

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — GPS waypoints delineating the flight paths for low altitude transects from a Garmin GPS unit. Transects were conducted from small aircraft over the National Park...

  5. Evaluation of line transect sampling based on remotely sensed data from underwater video

    Science.gov (United States)

    Bergstedt, R.A.; Anderson, D.R.

    1990-01-01

    We used underwater video in conjunction with the line transect method and a Fourier series estimator to make 13 independent estimates of the density of known populations of bricks lying on the bottom in shallows of Lake Huron. The pooled estimate of density (95.5 bricks per hectare) was close to the true density (89.8 per hectare), and there was no evidence of bias. Confidence intervals for the individual estimates included the true density 85% of the time instead of the nominal 95%. Our results suggest that reliable estimates of the density of objects on a lake bed can be obtained by the use of remote sensing and line transect sampling theory.

  6. Neonatal sciatic nerve transection induces TUNEL labeling of neurons in the rat spinal cord and DRG.

    Science.gov (United States)

    Oliveira, A L; Risling, M; Deckner, M; Lindholm, T; Langone, F; Cullheim, S

    1997-09-08

    Transection of a peripheral nerve in neonatal rats induces an extensive death of axotomized neurons. We demonstrate here that spinal motoneurons and sensory dorsal root ganglia neurons become TUNEL-labeled after sciatic nerve transection in neonatal rats, thus indicating that apoptotic mechanisms are involved in the death process. Interestingly, there is also a profound increase of TUNEL-labeled interneurons in the deep dorsal horn. This location suggests that an intact afferent input and/or contact with target cells is essential for interneuronal survival. Death of motoneurons and sensory neurons could be a result of the injury per se and/or the deprivation of neurotrophic substances, secondary to the loss of contact with target cells.

  7. Twenty-one years of mass balance observations along the K-transect, West Greenland

    Directory of Open Access Journals (Sweden)

    R. S. W. van de Wal

    2012-08-01

    Full Text Available A 21-yr record is presented of surface mass balance measurements along the K-transect. The series covers the period 1990–2011. Data are available at eight sites along a transect over an altitude range of 380–1850 m at approximately 67° N in West Greenland. The surface mass balance gradient is on average 3.8 × 10−3 m w.e. m−1, and the mean equilibrium line altitude is 1553 m a.s.l. Only the lower three sites within 10 km of the margin up to an elevation of 700 m experience a significant increasing trend in the ablation over the entire period. Data are available at: doi:10.1594/PANGAEA.779181.

  8. Twenty-one years of mass balance observations along the K-transect, West Greenland

    Directory of Open Access Journals (Sweden)

    R. S. W. van de Wal

    2012-05-01

    Full Text Available A 21-yr record is presented of surface mass balance measurements along the K-transect. The series covers the period 1990–2011. Data are available at 8 sites along a transect over an altitude range of 390–1850 m at approximately 67° N in West Greenland. The surface mass balance gradient is on average 3.8 × 10−3 m w.e. m−1, and the mean equilibrium line altitude is 1553 m a.s.l. Only the lower 3 sites within 10 km of the margin experience a significant increasing trend in the ablation over the entire period. Data are available at: http://doi.pangaea.de/10.1594/PANGAEA.779181.

  9. Development of spontaneous motility in the guppy embryo (Lebistes reticulatus) and the effect of spinal transection.

    Science.gov (United States)

    Richards, C; Pollack, E D

    1987-11-01

    Guppy (Lebistes reticulatus) embryos pass through a distinct sequence of motor behaviors that leads to swimming capability during the course of their development. We have characterized these activities in order of appearance, with several corresponding morphological features, as belonging to the coil stage, tail-twitch stage, S-movement stage, and swimming stage. A primary feature of development was an increase in the amount of activity per unit of time over these four stages. The developmental pattern of motility was not interrupted by spinal transection until the onset of swimming, implying that supraspinal information is not required for the occurrence of the primitive behaviors that precede swimming. Elimination of swimming by spinal transection did not elicit a reversion to less complex activities, suggesting that once the cerebral control for swimming is developed, it represents a hardwired system not behaviorally reducible to antecedent components.

  10. Geological controls on soil parent material geochemistry along a northern Manitoba-North Dakota transect

    Science.gov (United States)

    Klassen, R.A.

    2009-01-01

    As a pilot study for mapping the geochemistry of North American soils, samples were collected along two continental transects extending east–west from Virginia to California, and north–south from northern Manitoba to the US–Mexican border and subjected to geochemical and mineralogical analyses. For the northern Manitoba–North Dakota segment of the north–south transect, X-ray diffraction analysis and bivariate relations indicate that geochemical properties of soil parent materials may be interpreted in terms of minerals derived from Shield and clastic sedimentary bedrock, and carbonate sedimentary bedrock terranes. The elements Cu, Zn, Ni, Cr and Ti occur primarily in silicate minerals decomposed by aqua regia, likely phyllosilicates, that preferentially concentrate in clay-sized fractions; Cr and Ti also occur in minerals decomposed only by stronger acid. Physical glacial processes affecting the distribution and concentration of carbonate minerals are significant controls on the variation of trace metal background concentrations.

  11. Towards hydrodynamic simulations of wet particle systems

    NARCIS (Netherlands)

    Roy, S.; Luding, S.; Weinhart, T.

    2015-01-01

    This paper presents the rheology of weakly wetted granular materials in the slow frictional regime, using Discrete Element Method (DEM) simulations. In a split-bottom ring shear cell geometry a slow, quasi-static deformation leads to wide shear bands away from the walls. Dry non-cohesive and cohesiv

  12. Aqueous Wetting Films on Fused Quartz.

    Science.gov (United States)

    Mazzoco; Wayner

    1999-06-15

    Using an image analyzing interferometer, IAI, the interfacial characteristics of an isothermal constrained vapor bubble, CVB, in a quartz cuvette were studied as a precursor to heat transfer research. The effects of pH and electrolyte concentration on the meniscus properties (curvature and adsorbed film thickness) and the stability of the aqueous wetting films were evaluated. The surface potential in the electric double layer was a function of the cleaning and hydroxylation of the quartz surface. The disjoining pressure isotherm for pure water was very close to that predicted by the Langmuir equation. For aqueous solutions of moderate electrolyte concentration, the Gouy-Chapman theory provided a good representation of the electrostatic effects in the film. The effect of temperature on the film properties of aqueous solutions and pure water was also evaluated: The meniscus curvature decreased with increasing temperature, while Marangoni effects, intermolecular forces, and local evaporation and condensation enhanced waves on the adsorbed film layer. Pure water wetting films were mechanically metastable, breaking into droplets and very thin films (less than 10 nm) after a few hours. Aqueous wetting films with pH 12.4 proved to be stable during a test of several months, even when subjected to temperature and mechanical perturbations. The mechanical stability of wetting films can explain the reported differences between the critical heat fluxes of pure water and aqueous solutions. The IAI-CVB technique is a simple and versatile experimental technique for studying the characteristics of interfacial systems. Copyright 1999 Academic Press.

  13. Wet oxidation of salicylic acid solutions.

    Science.gov (United States)

    Collado, Sergio; Garrido, Laura; Laca, Adriana; Diaz, Mario

    2010-11-15

    Salicylic acid is a frequent pollutant in several industrial wastewaters. Uncatalyzed wet air oxidation, which is a promising technique for the treatment of phenolic effluents, has not been analyzed yet for the removal of salicylic acid. The effect of different conditions of pH (1.3-12.3), pressure (1.0-4.1 MPa), temperature (413-443 K), and initial concentrations (1.45-14.50 mM) on the wet oxidation of salicylate/salicylic acid solutions have here been investigated. The pH value of the reaction media was found to be a key parameter for the rate of the oxidation process with an optimum at pH 3.1, when the concentrations of salicylic acid and salicylate were similar. The oxidation reaction followed pseudofirst-order kinetics with respect to salicylic acid and 0.82 order with respect to dissolved oxygen. Additionally, the evolution of the color during the wet oxidation was analyzed and discussed in relation with the formation of intermediate compounds. Then, a reaction pathway for the noncatalytic wet oxidation of the salicylic acid was proposed.

  14. Wet oxidation of a spacecraft model waste

    Science.gov (United States)

    Johnson, C. C.; Wydeven, T.

    1985-01-01

    Wet oxidation was used to oxidize a spacecraft model waste under different oxidation conditions. The variables studied were pressure, temperature, duration of oxidation, and the use of one homogeneous and three heterogeneous catalysts. Emphasis is placed on the final oxidation state of carbon and nitrogen since these are the two major components of the spacecraft model waste and two important plant nutrients.

  15. Accretion Dynamics on Wet Granular Materials.

    Science.gov (United States)

    Saingier, Guillaume; Sauret, Alban; Jop, Pierre

    2017-05-19

    Wet granular aggregates are common precursors of construction materials, food, and health care products. The physical mechanisms involved in the mixing of dry grains with a wet substrate are not well understood and difficult to control. Here, we study experimentally the accretion of dry grains on a wet granular substrate by measuring the growth dynamics of the wet aggregate. We show that this aggregate is fully saturated and its cohesion is ensured by the capillary depression at the air-liquid interface. The growth dynamics is controlled by the liquid fraction at the surface of the aggregate and exhibits two regimes. In the viscous regime, the growth dynamics is limited by the capillary-driven flow of liquid through the granular packing to the surface of the aggregate. In the capture regime, the capture probability depends on the availability of the liquid at the saturated interface, which is controlled by the hydrostatic depression in the material. We propose a model that rationalizes our observations and captures both dynamics based on the evolution of the capture probability with the hydrostatic depression.

  16. Catalytic gasification of dry and wet biomass

    NARCIS (Netherlands)

    van Rossum, G.; Potic, B.; Kersten, Sascha R.A.; van Swaaij, Willibrordus Petrus Maria

    2009-01-01

    Catalytic gasification of dry biomass and of wet biomass streams in hot compressed water are reviewed and discussed as potential technologies for the production of synthesis gas, hydrogen- and methane-rich gas. Next to literature data also new experimental results from our laboratory on catalytic

  17. A note on the Fourier series model for analysing line transect data.

    Science.gov (United States)

    Buckland, S T

    1982-06-01

    The Fourier series model offers a powerful procedure for the estimation of animal population density from line transect data. The estimate is reliable over a wide range of detection functions. In contrast, analytic confidence intervals yield, at best, 90% confidence for nominal 95% intervals. Three solutions, one using Monte Carlo techniques, another making direct use of replicate lines and the third based on the jackknife method, are discussed and compared.

  18. Transect based analysis versus area based analysis to quantify shoreline displacement: spatial resolution issues.

    Science.gov (United States)

    Anfuso, Giorgio; Bowman, Dan; Danese, Chiara; Pranzini, Enzo

    2016-10-01

    Field surveys, aerial photographs, and satellite images are the most commonly employed sources of data to analyze shoreline position, which are further compared by area based analysis (ABA) or transect based analysis (TBA) methods. The former is performed by computing the mean shoreline displacement for the identified coastal segments, i.e., dividing the beach area variation by the segment length; the latter is based on the measurement of the distance between each shoreline at set points along transects. The present study compares, by means of GIS tools, the ABA and TBA methods by computing shoreline displacements recorded on two stretches of the Tuscany coast (Italy): the beaches of Punta Ala, a linear coast without shore protection structures, and the one at Follonica, which is irregular due to the presence of groins and detached breakwaters. Surveys were carried out using a differential global positioning system (DGPS) in RTK mode. For each site, a 4800-m-long coastal segment was analyzed and divided into ninety-six 50-m-long sectors for which changes were computed using both the ABA and TBA methods. Sectors were progressively joined to have a length of 100, 200, 400, and 800 m to examine how this influenced results. ABA and TBA results are highly correlated for transect distance and sector length up to 100 m at both investigated locations. If longer transects are considered, the two methods still produce good correlated data on the smooth shoreline (i.e. at Punta Ala), but correlation became significantly lower on the irregular shoreline (i.e., at Follonica).

  19. High-resolution MRI of intact and transected rat spinal cord.

    Science.gov (United States)

    Fraidakis, M; Klason, T; Cheng, H; Olson, L; Spenger, C

    1998-10-01

    Spinal cord transection at midthoracic level leads to an immediate loss of hindlimb motor function as well as to a progressive degeneration of descending and ascending spinal cord pathways. Thoracic spinal cord in unlesioned control rats and in rats 2 to 6 months after complete midthoracic transection were imaged in vivo using an ultrahigh-field (4.7 T) magnetic resonance spectrometer. High-resolution spin-echo and inversion-recovery pulse sequences were employed. In addition, the apparent diffusion coefficients (ADCs) in longitudinal and transverse directions of the spinal cord were determined. Anatomical MRI findings were confirmed in histological spinal cord tissue preparations. In healthy spinal cord, gray and white matter were easily discerned in proton density-weighted images. An infield resolution of max. 76 micrometers per pixel was achieved. In animals with chronic spinal cord transection changes in gray-white matter structure and contrast were observed toward the cut end. The spinal cord stumps showed a tapering off. This coincided with changes in the longitudinal/transverse ADC ratio. Fluid-filled cysts were found in most cases at the distal end of the rostral stump. The gap between the stumps contained richly vascularized scar tissue. Additional pathologic changes included intramedullary microcysts, vertebral dislocations, and in one animal compression of the spinal cord. In conclusion, MRI was found to be a useful method for in vivo investigation of anatomical and physiological changes following spinal cord transection and to estimate the degree of neural degeneration. In addition, MRI allows the description of the accurate extension of fluid spaces (e.g., cysts) and of water diffusion characteristics which cannot be achieved by other means in vivo.

  20. The Agulhas-Karoo Geoscience Transect: Structures and processes along the southern African continental margin

    OpenAIRE

    N. Parsiegla; Gohl, K.; Uenzelmann-Neben, G.; Jacek Stankiewicz

    2008-01-01

    The southern African continental transform margin is of great interest for the understanding of processes related to continental breakup, transform fault formation and vertical plate motion. Open questions include the cause and consequences for the high topography of southern Africa, neotectonic activity along the Agulhas-Falkland Fracture Zone and the formation of the Outeniqua Basin. As a component of the project “Inkaby yeAfrica”, the 900 km long Agulhas-Karoo Geoscience Transect was carri...

  1. Exploring the Biotic Pump Hypothesis along Non-linear Transects in Tropical South America

    Science.gov (United States)

    Molina, R.; Bettin, D. M.; Salazar, J. F.; Villegas, J. C.

    2014-12-01

    Forests might actively transport atmospheric moisture from the oceans, according to the biotic pump of atmospheric moisture (BiPAM) hypothesis. The BiPAM hypothesis appears to be supported by the fact that precipitation drops exponentially with distance from ocean along non-forested land transects, but not on their forested counterparts. Yet researchers have discussed the difficulty in defining proper transects for BiPAM studies. Previous studies calculate precipitation gradients either along linear transects maximizing distance to the ocean, or along polylines following specific atmospheric pathways (e.g., aerial rivers). In this study we analyzed precipitation gradients along curvilinear streamlines of wind in tropical South America. Wind streamlines were computed using long-term quarterly averages of meridional and zonal wind components from the ERA-Interim and NCEP/NCAR reanalyses. Total precipitation along streamlines was obtained from four data sources: TRMM, UDEL, ERA-Interim, and NCEP/NCAR. Precipitation on land versus distance from the ocean was analyzed along selected streamlines for each data source. As predicted by BiPAM, precipitation gradients did not decrease exponentially along streamlines in the vicinity of the Amazon forest, but dropped rapidly as distance from the forest increased. Remarkably, precipitation along streamlines in some areas outside the Amazon forest did not decrease exponentially either. This was possibly owing to convergence of moisture conveyed by low level jets (LLJs) in those areas (e.g., streamlines driven by the Caribbean and CHOCO jets on the Pacific coast of Colombia). Significantly, BiPAM held true even along long transects displaying strong sinuosity. In fact, the general conclusions of previous studies remain valid. Yet effects of LLJs on precipitation gradients need to be thoroughly considered in future BiPAM studies.

  2. Joint inversion of multi-configuration electromagnetic induction measurements to estimate soil wetting patterns during surface drip irrigation

    Science.gov (United States)

    Jadoon, Khan Z.; Moghadas, Davood; Jadoon, Aurangzeb; Missimer, Thomas M.; McCabe, Matthew

    2014-05-01

    In arid and semi-arid regions, development of precise information on the soil wetting pattern is important to optimize drip irrigation system design for sustainable agricultural water management. Usually mathematical models are commonly used to describe infiltration from a point source to design and manage drip irrigation systems. The extent to which water migrates laterally and vertically away from the drip emitter depends on many factors, including dripper discharge rate, the frequency of water application, duration of drip emission, the soil hydraulic characteristics, initial conditions, evaporation, root water uptake and root distribution patterns. However, several simplified assumptions in the mathematical models affect their utility to provide useful design information. In this respect, non-invasive geophysical methods, i.e., low frequency electromagnetic induction (EMI) systems are becoming powerful tools to map spatial and temporal soil moisture patterns due to fast measurement capability and sensitivity to soil water content and salinity. In this research, a new electromagnetic system, the CMD mini-Explorer, is used for soil characterization to measure the wetting patterns of drip irrigation systems using joint inversion of multi-configuration EMI measurements. Six transects of EMI measurements were carried out in a farm where Acacia trees are irrigated with brackish water using a drip irrigation system. EMI reference data (ground-truths) were calculated using vertical soil electrical conductivity recorded in different trenches along one of the measurement transects. Reference data is used for calibration to minimize the instrumental shifts which often occur in EMI data. Global and local optimization algorithms are used sequentially, to minimize the misfit between the measured and modeled apparent electrical conductivity (δa) to reconstruct the vertical electrical conductivity profile. The electromagnetic forward model based on full solution of Maxwell

  3. Contrasting pH buffering patterns in neutral-alkaline soils along a 3600 km transect in northern China

    OpenAIRE

    W. T. Luo; Nelson, P N; Li, M.-H.; J. P. Cai; Zhang, Y.Y.; Zhang, Y. G.; S. Yang; R. Z. Wang; Wang, Z. W.; Wu, Y. N.; X. G. Han; Y. Jiang

    2015-01-01

    Soil pH buffering capacity (pHBC) plays a crucial role in predicting acidification rates, yet its large-scale patterns and controls are poorly understood, especially for neutral-alkaline soils. Here, we evaluated the spatial patterns and drivers of pHBC along a 3600 km long transect (1900 km sub-transect with carbonate-containing soils and 1700 km sub-transect with non-carbonate-containing soils) across northern China. Soil pHBC was greater in the carbonate-containing soils ...

  4. Vascular endothelial growth factor promotes peripheral nerve regeneration after sciatic nerve transection in rat

    Directory of Open Access Journals (Sweden)

    Mohammadi Rahim

    2013-12-01

    Full Text Available 【Abstract】Objective: To evaluate the local effect of vascular endothelial growth factor (VEGF on transected sciatic nerve regeneration. Methods: Sixty male white Wistar rats were divided into four experimental groups randomly (n=15. In transected group the left sciatic nerve was transected and the stump was fixed to adjacent muscle. In treatment group the defect was bridged using a silicone graft filled with 10 µL VEGF. In silicone group the graft was filled with phosphate-buffered saline. In sham-operated group the sciatic nerve was ex- posed and manipulated. Each group was subdivided into three subgroups with five animals in each and nerve fibers were studied 4, 8 and 12 weeks after operation. Results: Behavioral test, functional study of sciatic nerve, gastrocnemius muscle mass and morphometric indi- ces confirmed a faster recovery of regenerated axons in VEGF group than in silicone group (P<0.05. In immunohistochemi- cal assessment, reactions to S-100 in VEGF group were more positive than that in silicone group. Conclusion: Local administration of VEGF will im- prove functional recovery and morphometric indices of sci- atic nerve. Key words: Peripheral nerves; Nerve regeneration; Sciatic nerve; Vascular endothelial growth factor

  5. Multifractal analyis of soil invertebrates along a transect under different land uses

    Science.gov (United States)

    Machado Siqueira, Glécio; Alves Silva, Raimunda; Vidal-Vázquez, Eva; Paz-González, Antonio

    2017-04-01

    Soil fauna play a central role in many essential ecosystem processes. Land use and management can have a dramatic effect upon soil invertebrate community. Indices based on soil invertebrates abundance and diversity are fundamental for soil quality assessment. Many soil properties and attributes have been shown to exhibit spatial variabilityThe aim of this study was to analyze the scaling heterogeneity of the soil invertebrate community sampled using pitfall traps across a transect. The field study was conducted at Mata Roma municipality, Maranhão State, Brazil. Transects were marked under seven different agricultural/forestry land uses (millet, soybean, maize, eucalyptus, pasture, secondary savannah and native savannah). Native vegetation was considered as a reference, whereas the agricultural fields showed a range of soil use intensities. Along these transects 130 pitfall per land use were installed. First, differences in community assemblages and composition under different land use systems were evaluated using classical indices. Then, the spatial distribution of soil fauna trapped by pitfall techniques, characterized through generalized dimension, Dq, and singularity spectra, f(α) - α, showed a well-defined multifractal structure. Differences in scaling heterogeneity and other multifractal characteristics were examined in relation to land use intensification.

  6. Laser-based single-axon transection for high-content axon injury and regeneration studies.

    Directory of Open Access Journals (Sweden)

    Darío Kunik

    Full Text Available The investigation of the regenerative response of the neurons to axonal injury is essential to the development of new axoprotective therapies. Here we study the retinal neuronal RGC-5 cell line after laser transection, demonstrating that the ability of these cells to initiate a regenerative response correlates with axon length and cell motility after injury. We show that low energy picosecond laser pulses can achieve transection of unlabeled single axons in vitro and precisely induce damage with micron precision. We established the conditions to achieve axon transection, and characterized RGC-5 axon regeneration and cell body response using time-lapse microscopy. We developed an algorithm to analyze cell trajectories and established correlations between cell motility after injury, axon length, and the initiation of the regeneration response. The characterization of the motile response of axotomized RGC-5 cells showed that cells that were capable of repair or regrowth of damaged axons migrated more slowly than cells that could not. Moreover, we established that RGC-5 cells with long axons could not recover their injured axons, and such cells were much more motile. The platform we describe allows highly controlled axonal damage with subcellular resolution and the performance of high-content screening in cell cultures.

  7. Erythropoietin Improves Place Learning in an 8-Arm Radial Maze in Fimbria-Fornix Transected Rats

    Directory of Open Access Journals (Sweden)

    Hana Malá

    2005-01-01

    Full Text Available Systemically administered human recombinant erythropoietin (EPO may have the potential to reduce the cognitive and behavioral symptoms of mechanical brain injury. In a series of studies, we address this possibility. We previously found that EPO given to fimbriafornix transected rats at the moment of injury could substantially improve the posttraumatic acquisition of an allocentric place learning task when such a task is administered in a water maze. Due to the clinical importance of such results, it is important to scrutinize whether the therapeutic effect of EPO is specific to the experimental setup of our original experiments or generalizes across test situations. Consequently, here we studied the effects of similarly administered EPO in fimbria-fornix transected and control operated rats, respectively, evaluating the posttraumatic behavioral/cognitive abilities in an allocentric place learning task administered in an 8-arm radial maze. The administration of EPO to the hippocampally injured rats was associated with a virtually complete elimination of the otherwise severe behavioral impairment caused by fimbria-fornix transection. In contrast, EPO had no detectable effect on the task acquisition of non-lesioned animals. The results of the present study confirm our previous demonstration of EPO's ability to reduce or eliminate the behavioral/cognitive consequences of mechanical injury to the hippocampus, while adding the important observation that such a therapeutic effect is not restricted to the specific experimental setup previously studied.

  8. Iliopsoas impingement after revision total hip arthroplasty treated with iliopsoas muscle transection.

    Science.gov (United States)

    Morohashi, Itaru; Homma, Yasuhiro; Kanda, Akio; Yamamoto, Yasuhiro; Obata, Hiroyuki; Mogami, Atsuhiko; Obayashi, Osamu; Kaneko, Kazuo

    2016-05-01

    Iliopsoas tendinitis after revision total hip arthroplasty (THA) is rare and its etiology and optimal treatment are still unclear. We report a case of iliopsoas impingement after revision THA with a Kerboull acetabular reinforcement device requiring two-level iliopsoas muscle transection. A 70-year-old woman presented to our hospital complaining of debilitating right groin pain after revision THA with a Kerboull reinforcement device. She had undergone multiple hip operations after experiencing a pelvic fracture in a motor vehicle accident. A lidocaine nerve block at the level of the Kerboull device resulted in temporary but marked reduction in pain and a diagnosis of psoas impingent. We performed surgery via an anterior approach to release the iliopsoas muscle from the lesser trochanter. After iliopsoas tenotomy was performed, the muscle was still under high tension because of dense adhesions. Repeat transection of the iliopsoas muscle at the level of the anterior branch of the Kerboull device resulted in loosening of the iliopsoas muscle and resolution of impingement. Postoperatively, the patient's groin pain completely disappeared, and she can now walk with a single cane and is satisfied with her result. Adhesions around the iliopsoas muscle likely contributed to the patient's groin pain. Open surgery to perform complete release of iliopsoas muscle impingement should be considered in patients with pain after revision THA. We reported a patient with Iliopsoas tendinitis after revision THA requiring two-level iliopsoas muscle transection.

  9. Epimacular brachytherapy for wet AMD: current perspectives

    Directory of Open Access Journals (Sweden)

    Casaroli-Marano RP

    2014-08-01

    Full Text Available Ricardo P Casaroli-Marano,1,2 Socorro Alforja,1 Joan Giralt,1 Michel E Farah2 1Instituto Clínic de Oftalmología (Hospital Clínic de Barcelona, University of Barcelona, Barcelona, Spain; 2Department of Ophthalmology and Visual Sciences, Universidade Federal de Sao Paulo, Escola Paulista de Medicina, Sao Paulo, Brazil Abstract: Age-related macular degeneration (AMD is considered the most common cause of blindness in the over-60 age group in developed countries. There are basically two forms of presentation: geographic (dry or atrophic and wet (neovascular or exudative. Geographic atrophy accounts for approximately 85%–90% of ophthalmic frames and leads to a progressive degeneration of the retinal pigment epithelium and the photoreceptors. Wet AMD causes the highest percentage of central vision loss secondary to disease. This neovascular form involves an angiogenic process in which newly formed choroidal vessels invade the macular area. Today, intravitreal anti-angiogenic drugs attempt to block the angiogenic events and represent a major advance in the treatment of wet AMD. Currently, combination therapy for wet AMD includes different forms of radiation delivery. Epimacular brachytherapy (EMBT seems to be a useful approach to be associated with current anti-vascular endothelial growth factor agents, presenting an acceptable efficacy and safety profile. However, at the present stage of research, the results of the clinical trials carried out to date are insufficient to justify extending routine use of EMBT for the treatment of wet AMD. Keywords: macular degeneration, radiation, vascular endothelial growth factor, combined therapy, intravitreal therapy, vitrectomy

  10. Wet feet or walking on sunshine? Reconstruction of wet-dry variations in the source region of modern man: the Chew Bahir project, southern Ethiopia

    Science.gov (United States)

    Foerster, V.; Trauth, M. H.; Junginger, A.; Asrat, A.; Lamb, H. F.; Gebru, T.; Wennrich, V.; Weber, M.; Rethemeyer, J.; Nowaczyk, N.; Frank, U.; Brown, M. C.; Schaebitz, F.

    2012-04-01

    Chew Bahir, today a saline mudflat in a tectonically-bounded basin in southern Ethiopia, lies between the Main Ethiopian Rift and the Omo-Turkana basin, site of the oldest known anatomically modern human fossils. Sedimentary records from Chew Bahir can therefore provide fundamental data for reconstructing Late Quaternary environments in the source region of Homo sapiens. This project focuses on rapid climate shifts and their influence on the biosphere, and is a preliminary study for the ICDP "Hominid Sites and Paleolakes Drilling Project", and part of Cologne University's CRC-806 programme "Our Way to Europe", which aim to determine climatic and environmental history of East Africa during the last 200 ka - 1 Ma. Reconstruction of the major dry-wet-dry alternations is crucial for understanding the impact of climate variability on the emergence and dispersal of Homo sapiens from Africa into Eurasia. We present new results from six cores (9-18 m depth) drilled in a NW-SE transect across the basin. Sedimentological, geochemical, physical, magnetic and biological indicators, and a suite of AMS radiocarbon dates, reveal substantial variations in moisture availability during the last 45 ka. The data provide valuable insight into the timing, possible abruptness and synchronicity of precession-driven climate shifts like the African Humid Period (AHP ~ 15-5 ka BP), the last major alternation from dry to wet to dry conditions, and show that the site responded sensitively to older climatic fluctuations on millennial to centennial timescales. Chew Bahir therefore presents a suitable climate archive of a highly variable environment and offers an opportunity to retrieve 200 ka sediment records of paleoenvironmental history during the physical and cultural evolution of Homo sapiens.

  11. Magnetopause transects

    Science.gov (United States)

    Sonnerup, B. U. Ö.; Guo, M.

    A novel method is described for reconstruction of two-dimensional current-layer structures from measurements taken by a single spacecraft traversing the layer. In its present form, the method is applicable only to 2D magneto-hydrostatic structures that are passively convected past the observing spacecraft. It is tested on a magnetopause crossing of the tangential-discontinuity type by the spacecraft AMPTE/IRM. The magnetic structures recovered include a magnetic island located between two X-type nulls as well as a magnetic ‘worm hole’ through which a bundle of weak magnetic flux appears to connect the magnetosphere and the magnetosheath.

  12. FBSAB RECRUIT Reef Fish Belt Transect Survey at Hawaii Island (Big Island), Main Hawaiian Islands, 2009 (NODC Accession 0073870)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Shore-based belt transects were conducted at 1 to ~ 5 m depths at a total two (2) sites on the leeward coast (South Kohala district) of the Big Island (Hawaii...

  13. Quantitative analysis of photoquadrats acquired at Johnston Atoll permanent transect site 2A-P on June 30, 2000

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This spreadsheet summarizes the number of corals photographed along a permanent transect line at Underwater Site 2A-P at Johnston Atoll on 6/30/2000.

  14. Quantitative analysis of photoquadrats acquired at Johnston Atoll permanent transect site 6P on July 3, 2000

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This spreadsheet summarizes the number of corals photographed along a permanent transect line at Underwater Site 6P at Johnston Atoll on 7/3/2000.

  15. Quantitative analysis of photoquadrats acquired at Howland Island permanent transect site 5P on January 21, 2004

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This spreadsheet summarizes the number of corals photographed along a permanent transect line at Underwater Site 5P at Howland Island on 1/21/2004.

  16. Quantitative analysis of photoquadrats acquired at Johnston Atoll permanent transect site 5P on July 2, 2000

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This spreadsheet summarizes the number of corals photographed along a permanent transect line at Underwater Site 5P at Johnston Atoll on 7/2/2000.

  17. Hawaii Coral Reef Assessment and Monitoring Program (CRAMP): Benthic Data from Rapid Assessment Transects 2001-2004 (NODC Accession 0002464)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset consists of CRAMP Rapid Assessment Transect surveys taken in 2001-2004 and includes quantitative estimates of substrate type and species. The types and...

  18. Quantitative analysis of photoquadrats acquired at Jarvis Island permanent transect site 4P on March 23, 2000

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This spreadsheet summarizes the number of corals photographed along a permanent transect line at Underwater Site 4P at Jarvis Island NWR on 3/23/2000.

  19. Quantitative analysis of photoquadrats acquired at Kingman Reef permanent transect site 5P on March 17, 2002

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This spreadsheet summarizes the number of corals photographed along a permanent transect line at Underwater Site 5P at Kingman Reef on 3/17/2002.

  20. Quantitative analysis of photoquadrats acquired at Jarvis Island permanent transect site 11P on March 27, 2004

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This spreadsheet summarizes the number of corals photographed along a permanent transect line at Underwater Site 11P at Jarvis Island NWR on 3/27/2004.

  1. Quantitative analysis of photoquadrats acquired at Johnston Atoll permanent transect site 4P on July 1, 2000

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This spreadsheet summarizes the number of corals photographed along a permanent transect line at Underwater Site 4P at Johnston Atoll on 7/1/2000.

  2. Quantitative analysis of photoquadrats acquired at Johnston Atoll permanent transect site 10P on January 15, 2004

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This spreadsheet summarizes the number of corals photographed along a permanent transect line at Underwater Site 10P at Johnston Atoll NWR on 1/15/2004.

  3. Quantitative analysis of photoquadrats acquired at Johnston Atoll permanent transect site 3B-P on July 1, 2000

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This spreadsheet summarizes the number of corals photographed along a permanent transect line at Underwater Site 3B-P at Johnston Atoll on 7/1/2000.

  4. Quantitative analysis of photoquadrats acquired at Johnston Atoll permanent transect site 2B-P on June 30, 2000

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This spreadsheet summarizes the number of corals photographed along a permanent transect line at Underwater Site 2B-P at Johnston Atoll on 6/30/2000.

  5. Hawaii Coral Reef Assessment and Monitoring Program (CRAMP): Benthic Data from Rapid Assessment Transects Maui 2006 (NODC Accession 0039383)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset consists of CRAMP Rapid Assessment Transect surveys taken in 2006 and includes quantitative estimates of substrate type and species. In 2006, there were...

  6. Video Transect Images from the Hawaii Coral Reef Assessment and Monitoring Program (CRAMP): Data from 2000 (NODC Accession 0000728)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset consists of video transect images (TIF files) from CRAMP surveys taken in 2000 at 23 sites, some of which had multiple depths. Estimates of substrate...

  7. Video Transect Images from the Hawaii Coral Reef Assessment and Monitoring Program (CRAMP): Data from 2003 (NODC Accession 0001732)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset consists of video transect images (TIF files) from CRAMP surveys taken in 2003 at 15 sites, some of which had multiple depths. Estimates of substrate...

  8. Video transect images from the Hawaii Coral Reef Assessment and Monitoring Program (CRAMP): data from year 1999 (NODC Accession 0000671)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset consists of video transect images (JPEG files) from CRAMP surveys taken in 1999 at 26 sites, some of which had multiple depths. Estimates of substrate...

  9. AFSC/NMML: Cetacean line-transect survey in the eastern Bering Sea shelf; 1999, 2000, 2002, and 2004

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Visual surveys for cetaceans were conducted on the eastern Bering Sea shelf along transect lines, in association with the AFSC.s echo integration trawl surveys for...

  10. Video transect images from the Hawaii Coral Reef Assessment and Monitoring Program (CRAMP): data from 2002 (NODC Accession 0000961)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset consists of video transect images (TIF files) from CRAMP surveys taken in 2002 at 23 sites, some of which had multiple depths. Estimates of substrate...

  11. Video Transect Images from the Hawaii Coral Reef Assessment and Monitoring Program (CRAMP):Data from 2003 (NODC Accession 0001732)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset consists of video transect images (TIF files) from CRAMP surveys taken in 2003 at 15 sites, some of which had multiple depths. Estimates of substrate...

  12. Video transect images from the Hawaii Coral Reef Assessment and Monitoring Program (CRAMP): data from 2000 (NODC Accession 0000728)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset consists of video transect images (TIF files) from CRAMP surveys taken in 2000 at 23 sites, some of which had multiple depths. Estimates of substrate...

  13. Digital Still Transect Images from the Hawaii Coral Reef Assessment and Monitoring Program (CRAMP): Data from 2004 (NODC Accession 0037908)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset consists of video transect images (JPG files) from CRAMP surveys taken in 2004 at 6 sites, some of which had multiple depths. Digital images are...

  14. Video Transect Images from the Hawaii Coral Reef Assessment and Monitoring Program (CRAMP): Data from 2002 (NODC Accession 0000961)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset consists of video transect images (TIF files) from CRAMP surveys taken in 2002 at 23 sites, some of which had multiple depths. Estimates of substrate...

  15. Video Transect Images (1999) from the Hawaii Coral Reef Assessment and Monitoring Program (CRAMP) (NODC Accession 0000671)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset consists of video transect images (JPEG files) from CRAMP surveys taken in 1999 at 26 sites, some of which had multiple depths. Estimates of substrate...

  16. Digital Still Transect Images from the Hawaii Coral Reef Assessment and Monitoring Program (CRAMP) Maui 2006 (NODC Accession 0039627)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset consists of digital still transect images (JPG files) from CRAMP surveys taken on Maui in 2006 at 8 sites, some of which had multiple depths. Surveys...

  17. Groundwater Dynamics along Forest-Marsh-Tidal Creek Transects in North Inlet Estuary, South Carolina: 1994-1996

    Data.gov (United States)

    Baruch Institute for Marine and Coastal Sciences, Univ of South Carolina — Ground water level elevations were collected every 10 to 15 days from piezometers stationed along three forest-marsh-tidal creek transects (B, C, and D) across the...

  18. Comparison of coral census from Jarvis permanent transect site 11P on March 10, 2002 and March 27, 2004

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This spreadsheet summarizes the number of corals photographed along a permanent transect line at Underwater Site 11P at Jarvis Island NWR on 3/27/2004 and compares...

  19. Quantitative analysis of photoquadrats acquired at Palmyra Atoll permanent transect site 15P on March 31, 2004

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This spreadsheet summarizes the number of corals photographed along a permanent transect line at Underwater Site 15P at Palmyra Atoll on 3/31/2004.

  20. Quantitative analysis of photoquadrats acquired at Palmyra Atoll permanent transect site 15P on March 15, 2002

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This spreadsheet summarizes the number of corals photographed along a permanent transect line at Underwater Site 15P at Palmyra Atoll on 3/15/2002.

  1. Quantitative analysis of photoquadrats acquired at Johnston Atoll permanent transect site 1B-P on June 29, 2000

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This spreadsheet summarizes the number of corals photographed along a permanent transect line at Underwater Site 1B-P at Johnston Atoll on 6/29/2000.

  2. Traumatic cervical cord transection without facet dislocations--a proposal of combined hyperflexion-hyperextension mechanism: a case report.

    Science.gov (United States)

    Cha, Yoo-Hyun; Cho, Tai-Hyoung; Suh, Jung-Keun

    2010-08-01

    A patient is presented with a cervical spinal cord transection which occurred after a motor vehicle accident in which the air bag deployed and the seat belt was not in use. The patient had complete quadriplegia below the C5 level and his imaging study showed cervical cord transection at the level of the C5/6 disc space with C5, C6 vertebral bodies and laminar fractures. He underwent a C5 laminectomy and a C4-7 posterior fusion with lateral mass screw fixation. Previous reports have described central cord syndromes occurring in hyperextension injuries, but in adults, acute spinal cord transections have only developed after fracture-dislocations of the spine. A case involving a post-traumatic spinal cord transection without any evidence of radiologic facet dislocations is reported. Also, we propose a combined hyperflexion-hyperextension mechanism to explain this type of injury.

  3. Quantitative analysis of photoquadrats acquired at Johnston Atoll permanent transect site 1A-P on June 29, 2000

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This spreadsheet summarizes the number of corals photographed along a permanent transect line at Underwater Site 1A-P at Johnston Atoll on 6/29/2000.

  4. Quantitative analysis of photoquadrats acquired at Jarvis Island permanent transect site 11P on March 10, 2002

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This spreadsheet summarizes the number of corals photographed along a permanent transect line at Underwater Site 11P at Jarvis Island NWR on 3/10/2002.

  5. Quantitative analysis of photoquadrats 1-35 acquired at Baker Island permanent transect site 5P on March 19, 2000

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This spreadsheet summarizes the number of corals photographed along a permanent transect line at Underwater Site 5P at Baker Island on 3/19/2000.

  6. FBSAD Recruit Reef Fish Belt Transect Survey at Hawaii Island (Big Island), Main Hawaiian Islands, 2005 (NODC Accession 0046935)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Shore-based belt transects were conducted at 8-13 m depths at 3 longshore sites on the leeward coast (North and South Kohala districts) of the Big Island (Hawaii...

  7. Effects of climate and geochemistry on soil organic matter stabilization and greenhouse gas emissions along altitudinal transects in different mountain regions

    Science.gov (United States)

    Griepentrog, Marco; Bodé, Samuel; Boudin, Mathieu; Dercon, Gerd; Doetterl, Sebastian; Matulanya, Machibya; Msigwa, Anna; Vermeir, Pieter; Boeckx, Pascal

    2017-04-01

    Terrestrial ecosystems are strongly influenced by climate change and soils are key compartments of the global carbon (C) cycle in terms of their potential to store or release significant amounts of C. This study is part of the interregional IAEA Technical Cooperation Project ``Assessing the Impact of Climate Change and its Effects on Soil and Water Resources in Polar and Mountainous Regions (INT5153)'' aiming to improve the understanding of climate change impacts on soil organic carbon (SOC) in fragile polar and high mountainous ecosystems at local and global scale for their better management and conservation. The project includes 13 benchmark sites situated around the world. Here we present novel data from altitudinal transects of three different mountain regions (Mount Kilimanjaro, Tanzania; Mount Gongga, China; Cordillera Blanca, Peru). All altitudinal transects cover a wide range of natural ecosystems under different climates and soil geochemistry. Bulk soil samples (four field replicates per ecosystem) were subjected to a combination of aggregate and particle-size fractionation followed by organic C, total nitrogen, stable isotope (13C, 15N) and radiocarbon (14C) analyses of all fractions. Bulk soils were further characterized for their geochemistry (Na, K, Ca, Mg, Al, Fe, Mn, Si, P) and incubated for 63 days to assess greenhouse gas emissions (CO2, CH4, NO, N2O). Further, stable C isotopic signature of CO2 was measured to determine the isotopic signature of soil respiration (using Keeling plots) and to estimate potential respiration sources. The following four ecosystems were sampled at an altitudinal transect on the (wet) southern slopes of Mount Kilimanjaro: savannah (920m), lower montane rain forests with angiosperm trees (2020m), upper montane cloud forest with gymnosperm trees (2680m), subalpine heathlands (3660m). Both forests showed highest C contents followed by subalpine and savannah. The largest part of SOC was found in particulate organic matter

  8. Immune system augmentation by glatiramer acetate of peripheral nerve regeneration-crush versus transection models of rat sciatic nerve.

    Science.gov (United States)

    Luria, Shai; Cohen, Avraham; Safran, Ori; Firman, Shimon; Liebergall, Meir

    2013-10-01

    Immune system augmentation, using the antigen glatiramer acetate (GA), which is known to affect cellular immunity, has been shown to have a positive effect on peripheral nerve regeneration. We aimed to compare the effect of GA on the regeneration of crushed versus transected nerves. Wild-type rats underwent crush or transection and repair of the sciatic nerve. They were examined 3 weeks postinjury histologically (axon count) and functionally (tibialis anterior muscle weight and footprint analysis). GA was found to augment regeneration both histologically and functionally. In the transected nerve, a significant increase in axon count distal to the injury site was seen in the GA group versus control. A similar yet statistically insignificant trend was found in the crushed nerve. Improvement was found in the footprint analysis between the GA and control groups in both crush and transected nerve groups. We found improvement in the footprint analysis in the crush versus transection group. GA was found to improve the regeneration of the peripheral nerve. Histologically, this was more pronounced in the transection injury. The discrepancy between the different functional measures examined may be explained by the distance of the reinnervated muscles evaluated from the injury site. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  9. How much effort should be employed for surveying a low-diversity Amazonian mammal assemblage using line-transects?

    Directory of Open Access Journals (Sweden)

    Ítalo Mourthé

    2013-02-01

    Full Text Available Line-transect surveys are commonly used for sampling large mammals, but estimates of the effort needed to reliably surveying low-diversity assemblages of mammals are scarce. Using data from line-transects and species accumulation curves, I examined whether or not a sampling effort previously suggested to survey mammals elsewhere (ca. 85-100 km would be satisfactory for surveying a low-diversity assemblage of large mammals in the Rio Negro basin in northern Amazonia. In total, 14 mammals were recorded after an accumulated effort of 690 km walked. The desired threshold of completeness was only achieved in one of six transects after an average effort of 115 km surveyed. Considering the entire landscape (all transects pooled, survey completeness was reached after a much higher effort. Moreover, the theoretical effort required to achieve completeness was estimated to be 150-360 km per transect, and 512 km for the landscape. Further studies are required to fully understand this issue, but meanwhile it is safest to assume that higher sampling efforts should be employed when surveying low-diversity assemblages through diurnal line-transects in northwestern Amazonia to get robust estimates of mammal richness.

  10. Wetting and Roughening of Interfaces with Disorder

    Science.gov (United States)

    Alava, M. J.; Duxbury, P. M.; Seppälä, E. T.

    1997-03-01

    The properties of Ising interfaces change with the introduction of disorder. The roughening and scaling of these ``minimum energy surfaces'' is studied numerically at T=0 using exact optimization techniques. In 3D random-bond systems there is a disorder driven roughening transition for 100 oriented lattices, whereas 111 interfaces are algebraically rough for any non-zero disorder. However, in the 111 case there is an anomalous singular behavior in the parrow 1 limit of random dilution. The wetting of surfaces in the 3-d Ising model depends on whether the bulk interface is rough or (almost) flat. This is analyzed for both complete wetting and for disordered substrates. The results are compared with scaling theory.

  11. Wet spinning of solid polyamic acid fibers

    Science.gov (United States)

    Dorogy, William E., Jr. (Inventor); St.clair, Anne K. (Inventor)

    1991-01-01

    The invention is a process for the production of solid aromatic polyamic acid and polyimide fibers from a wet gel or coagulation bath wet gel using N,N-dimethylacetamide (DMAc) solutions of the polyamic acid derived from aromatic dianhydrides such as 3,3',4,4' benzophenonetetra carboxylic dianhydride (BTDA) and aromatic diamines such as 4,4'-oxydianiline (4,4'-ODA). By utilizing the relationship among coagulation medium and concentration, resin inherent viscosity, resin percent solids, filament diameter, and fiber void content, it is possible to make improved polyamic acid fibers. Solid polyimide fibers, obtained by the thermal cyclization of the polyamic acid precursor, have increased tensile properties compared to fibers containing macropores from the same resin system.

  12. Erosion dynamics of a wet granular medium.

    Science.gov (United States)

    Lefebvre, Gautier; Jop, Pierre

    2013-09-01

    Liquid may give strong cohesion properties to a granular medium, and confer a solidlike behavior. We study the erosion of a fixed circular aggregate of wet granular matter subjected to a flow of dry grains inside a half-filled rotating drum. During the rotation, the dry grains flow around the fixed obstacle. We show that its diameter decreases linearly with time for low liquid content, as wet grains are pulled out of the aggregate. This erosion phenomenon is governed by the properties of the liquids. The erosion rate decreases exponentially with the surface tension while it depends on the viscosity to the power -1. We propose a model based on the force fluctuations arising inside the flow, explaining both dependencies: The capillary force acts as a threshold and the viscosity controls the erosion time scale. We also provide experiments using different flowing grains, confirming our model.

  13. Versatile wetting measurement of microplate wells

    Science.gov (United States)

    Ng, Enoch Ming Wei; Cheong, Brandon Huey-Ping; Yu, Yang; Liew, Oi Wah; Ng, Tuck Wah

    2016-11-01

    A method to measure the contact angle, which is indicative of wetting, using small liquid volumes dispensed directly on microplate wells is described and demonstrated. Experiments with enhanced green protein samples of volumes 4.4-6 μl showed no measured variance in the contact angle. Experiments with phosphate buffer solution with varied concentrations of a non-ionic detergent (Tween 20) dissolved, however, revealed smaller contact angles with increased detergent concentration. It is experimentally shown that drops can be located up to 7° from the lowest position of the well without affecting the accuracy of contact angle measurements. Numerical simulations confirm the ability of the drops to manifest the correct contact angle despite the lack of axis-symmetry in their shape while residing on a circular surface. This method offers a convenient means to determine the wetting characteristics of different liquid samples in different microplates.

  14. Compaction dynamics of wet granular packings

    Science.gov (United States)

    Vandewalle, Nicolas; Ludewig, Francois; Fiscina, Jorge E.; Lumay, Geoffroy

    2013-03-01

    The extremely slow compaction dynamics of wet granular assemblies has been studied experimentally. The cohesion, due to capillary bridges between neighboring grains, has been tuned using different liquids having specific surface tension values. The characteristic relaxation time for compaction τ grows strongly with cohesion. A kinetic model, based on a free volume kinetic equations and the presence of a capillary energy barrier (due to liquid bridges), is able to reproduce quantitatively the experimental curves. This model allows one to describe the cohesion in wet granular packing. The influence of relative humidity (RH) on the extremely slow compaction dynamics of a granular assembly has also been investigated in the range 20 % - 80 % . Triboelectric and capillary condensation effects have been introduced in the kinetic model. Results confirm the existence of an optimal condition at RH ~ 45 % for minimizing cohesive interactions between glass beads.

  15. Progress of catalytic wet air oxidation technology

    Directory of Open Access Journals (Sweden)

    Guolin Jing

    2016-11-01

    Full Text Available Catalytic wet air oxidation (CWAO is one of the most economical and environmental-friendly advanced oxidation process for high strength, toxic, hazardous and non-biodegradable contaminants under milder conditions, which is developed on the basic of wet air oxidation. Various heterogeneous catalysts including noble metals and metal oxides have been extensively studied to enhance the efficiency of CWAO. The advances in the research on wastewater treatment by CWAO process are summarized in aspects of reaction mechanism investigation, reaction kinetics study and catalyst development. It is pointed out that the preparation of active and stable catalysts, the investigation on reaction mechanisms and the study on reaction kinetics models are very important for the promotion of CWAO application.

  16. Pipe flow of pumping wet shotcrete based on lubrication layer

    National Research Council Canada - National Science Library

    Chen, Lianjun; Liu, Guoming; Cheng, Weimin; Pan, Gang

    2016-01-01

    .... The paper studied the pipe flow law of wet shotcrete based on lubrication layer by build the experimental pumping circuit of wet shotcrete that can carry out a number of full-scale pumping tests...

  17. Making Activated Carbon by Wet Pressurized Pyrolysis

    Science.gov (United States)

    Fisher, John W.; Pisharody, Suresh; Wignarajah, K.; Moran, Mark

    2006-01-01

    A wet pressurized pyrolysis (wet carbonization) process has been invented as a means of producing activated carbon from a wide variety of inedible biomass consisting principally of plant wastes. The principal intended use of this activated carbon is room-temperature adsorption of pollutant gases from cooled incinerator exhaust streams. Activated carbon is highly porous and has a large surface area. The surface area depends strongly on the raw material and the production process. Coconut shells and bituminous coal are the primary raw materials that, until now, were converted into activated carbon of commercially acceptable quality by use of traditional production processes that involve activation by use of steam or carbon dioxide. In the wet pressurized pyrolysis process, the plant material is subjected to high pressure and temperature in an aqueous medium in the absence of oxygen for a specified amount of time to break carbon-oxygen bonds in the organic material and modify the structure of the material to obtain large surface area. Plant materials that have been used in demonstrations of the process include inedible parts of wheat, rice, potato, soybean, and tomato plants. The raw plant material is ground and mixed with a specified proportion of water. The mixture is placed in a stirred autoclave, wherein it is pyrolized at a temperature between 450 and 590 F (approximately between 230 and 310 C) and a pressure between 1 and 1.4 kpsi (approximately between 7 and 10 MPa) for a time between 5 minutes and 1 hour. The solid fraction remaining after wet carbonization is dried, then activated at a temperature of 500 F (260 C) in nitrogen gas. The activated carbon thus produced is comparable to commercial activated carbon. It can be used to adsorb oxides of sulfur, oxides of nitrogen, and trace amounts of hydrocarbons, any or all of which can be present in flue gas. Alternatively, the dried solid fraction can be used, even without the activation treatment, to absorb

  18. Wet flue gas desulphurization and new fuels

    Energy Technology Data Exchange (ETDEWEB)

    Kiil, S.; Dam-Johansen, K.; Michelsen, M.L.

    1998-04-01

    This thesis describes experimental and theoretical investigations of wet flue gas desulphurization (FGD). A review of the current knowledge of the various rate determining steps in wet FDG plants is presented. The mechanism underlying the rate of dissolution of finely grained limestone particles was examined in a laboratory batch apparatus using acid titration. Three Danish limestones of different origin were tested. A transient, mass transport controlled, mathematical model was developed to describe the dissolution process. Model predictions were found to be qualitatively in good agreement with experimental data. Empirical correlations for the dimensionless mass transfer coefficients in a pilot plant (falling-film column) were determined. The presence of inert particles in the liquid phase was found to decrease the rate of gas phase mass transport with up to 15%, though the effect could not be correlated. A detailed model for a wet FGD pilot plant, based on the falling film principle, was developed. All important rate determining steps, absorption of SO{sub 2}, oxidation of HSO{sub 3}{sup -}, dissolution of limestone, and crystallisation of gypsum were included. Model predictions were compared to experimental data such as gas phase concentration profiles of SO{sub 2}, slurry pH-profiles, solids contents of slurry, liquid phase concentrations, and residual limestone in the gypsum. The possibility of co-firing straw and coal was investigated in a full-scale power plant. No effects on the overall performance of the wet FGD plant were observed, though laboratory experiments with fine dust and fly ash from the full-scale experiments showed a decrease in limestone reactivity. (EG) EFP-95. 45 refs.; Also ph.d. thesis of Soeren Kiil

  19. Wetting properties of molecularly rough surfaces

    Science.gov (United States)

    Svoboda, Martin; Malijevský, Alexandr; Lísal, Martin

    2015-09-01

    We employ molecular dynamics simulations to study the wettability of nanoscale rough surfaces in systems governed by Lennard-Jones (LJ) interactions. We consider both smooth and molecularly rough planar surfaces. Solid substrates are modeled as a static collection of LJ particles arranged in a face-centered cubic lattice with the (100) surface exposed to the LJ fluid. Molecularly rough solid surfaces are prepared by removing several strips of LJ atoms from the external layers of the substrate, i.e., forming parallel nanogrooves on the surface. We vary the solid-fluid interactions to investigate strongly and weakly wettable surfaces. We determine the wetting properties by measuring the equilibrium droplet profiles that are in turn used to evaluate the contact angles. Macroscopic arguments, such as those leading to Wenzel's law, suggest that surface roughness always amplifies the wetting properties of a lyophilic surface. However, our results indicate the opposite effect from roughness for microscopically corrugated surfaces, i.e., surface roughness deteriorates the substrate wettability. Adding the roughness to a strongly wettable surface shrinks the surface area wet with the liquid, and it either increases or only marginally affects the contact angle, depending on the degree of liquid adsorption into the nanogrooves. For a weakly wettable surface, the roughness changes the surface character from lyophilic to lyophobic due to a weakening of the solid-fluid interactions by the presence of the nanogrooves and the weaker adsorption of the liquid into the nanogrooves.

  20. Fluidization of wet granulates under shear.

    Science.gov (United States)

    Rahbari, S H Ebrahimnazhad; Vollmer, J; Herminghaus, S; Brinkmann, M

    2010-12-01

    Small amounts of a wetting liquid render sand a stiff and moldable material. The cohesive forces between the sand grains are caused by capillary bridges at the points of contact. Due to the finite strength of these bridges wet sand undergoes a transition from an arrested (i.e., solidified) to a fluidized state under an externally applied shear force. The transition between these two dynamic states is studied in a MD-type simulation of a two-dimensional assembly of bidisperse frictionless disks under the action of a cosine force profile. In addition to soft core repulsion the disks interact through a hysteretic and short ranged attractive force modeling the effect of the capillary bridges. In this model the transition between the fluidized and the arrested state is discontinuous and hysteretic. The parameter dependence of the critical force for solidification is modeled by combining theoretical arguments with a detailed numerical exploration of the transition. We address a range of densities from slightly below close packing until slightly above densities where the system approaches a shear-banded state. Differences and similarities of the transition in wet granulates to the jamming transition are also addressed.

  1. Study of polycaprolactone wet electrospinning process

    Directory of Open Access Journals (Sweden)

    E. Kostakova

    2014-08-01

    Full Text Available Wet electrospinning is a useful method for 3-dimensional structure control of nanofibrous materials. This innovative technology uses a liquid collector instead of the metal one commonly used for standard electrospinning. The article compares the internal structural features of polycaprolactone (PCL nanofibrous materials prepared by both technologies. We analyze the influence of different water/ethanol compositions used as a liquid collector on the morphology of the resultant polycaprolactone nanofibrous materials. Scanning electron micro-photographs have revealed a bimodal structure in the wet electrospun materials composed of micro and nanofibers uniformly distributed across the sample bulk. We have shown that the full-faced, twofold fiber distribution is due to the solvent composition and is induced and enhanced by increasing the ethanol weight ratio. Moreover, the comparison of fibrous layers morphology obtained by wet and dry spinning have revealed that beads that frequently appeared in dry spun materials are created by Plateau-Rayleigh instability of the fraction of thicker fibers. Theoretical conditions for spontaneous and complete immersion of cylindrical fibers into a liquid collector are also derived here.

  2. Design Aspects of Wet Scrubber System

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyun-Chul; Bang, Young-suk; Jung, Woo-Young; Lee, Doo-Yong [FNC Technology Co. Ltd., Yongin (Korea, Republic of)

    2015-10-15

    The water pool in the wet scrubber system has advantage to cope with decay heat based on the thermal hydraulic balance such as condensation and evaporation inside it. This study focuses on the design aspects of the wet scrubber system to estimate the required water pool mass during the mission time and size of the scrubbing tank including inner structures. The design of the wet scrubber system include the estimation of the required water mass during the mission time and sizing of the scrubber vessel to contain the water pool. The condensation due to the inlet steam and evaporation due to the steam and non-condensable gas superheat and decay heat from filtered fission products should be considered to estimate the water mass required to maintain its function during the mission time. On the other hand, the level swelling due to the noncondensable gas is another important design aspect on the sizing of the scrubber vessel and determination of the entry elevation of the filtration components such as the droplet separator or filter. The minimum water level based on the minimum collapsed water level should be higher than the exit of scrubber nozzle.

  3. STUDY ON WET STRENGTH PERFORMANCE OF KENAF MULCH

    Institute of Scientific and Technical Information of China (English)

    Jinghui Zhou; Xinge Wu; Hongwei Zhu

    2004-01-01

    Optimum applied technical conditions of wet strength agent for kenaf mulch were studied in this article. Breaking length, wet-dry strength ratio, tear index and burst index of kenaf mulch were measured and optimum wet strength agent was selected. The aim is to make mulch have properties of heat preservation, humidity preservation, growth prompting, biodegradation and maximum wet strength and to improve impact resistance of mulch to rainwater so as to assure growth of plant and replace plastic film.

  4. Characteristics of wet work in the cleaning industry

    NARCIS (Netherlands)

    Jungbauer, F H W; Van Der Harst, J J; Schuttelaar, M L; Groothoff, J W; Coenraads, P J

    Wet work is the main cause of occupational contact dermatitis in the cleaning industry. Dermatologists and occupational physicians need to base their primary and secondary prevention for workers in the cleaning industry on the characteristics of wet work exposures. We quantified the burden of wet

  5. A new remote optical wetness sensor and its applications

    NARCIS (Netherlands)

    Heusinkveld, B.G.; Berkowicz, S.M.; Jacobs, A.F.G.; Hillen, W.C.A.M.; Holtslag, A.A.M.

    2008-01-01

    An optical wetness sensor (OWS) was developed for continuous surface wetness measurements. The sensor is an all-weather instrument that does not interfere with the surface wetting and drying process and is unaffected by solar radiation. It is equipped with its own light source with which it can scan

  6. Deformation in the Bolivian Subandes: a reconstruction of geologic structures along two transects across the Andean Front in Southern Bolivia

    Science.gov (United States)

    Hadeen, Xennephone; Zeilinger, Gerold

    2016-04-01

    The Southern Bolivian Subandes is a highly tectonically active region in the Andes since deformation began approx. 10 Ma ago. The study area is located in the Southern Bolivian Subandes southwest of Santa Cruz. Observations were taken along two transects with each being around 100 km long. They stretch from the Subandes-Interandean boundary into the Chaco Plain. The northern transect extends from Abapó in the Chaco Plain and it continues west near Vallegrande and ends just west of Pucara near La Higuera. The southern transect initiates near Charagua in the Chaco Plain. Then it continues west through Villa Vaca Guzmán and ends around 25 km west of Monteagudo. Structural and stratigraphic data were collected along the two transects. The locations of major geologic structures such as thrust faults, anticlines and synclines were mapped. The map along with the data from the two cross sections was then used to generate a 3D model of the Subandean fold and thrust belt between Abapó and Monteagudo. The cross sections were than restored to quantify the amount of shortening that had occurred over the past 10 million years. The southern transect has undergone 65 km of shortening while 50 to 80 km of shortening have transpired along the less constrain northern transect. The estimated rate of deformation averages at 8 mm/yr. The timing of deformation may differ between the two transects. Deformation may have initiated earlier or undergone at a faster rate in the northern transect than in the southern transect. It is also possible that the decollement is shallower in the western portion of the northern transect. We observe that the east propagating anticlines verge to the west. This may be due to the anticlines being cut by exposed or blind thrust faults and then rotated counterclockwise. They rotate while piggybacking on younger thrust faults that developed and propagate to the east of the anticlines. We postulate deformation continues to propagate eastward into the Chaco

  7. Bird radar validation in the field by time-referencing line-transect surveys.

    Science.gov (United States)

    Dokter, Adriaan M; Baptist, Martin J; Ens, Bruno J; Krijgsveld, Karen L; van Loon, E Emiel

    2013-01-01

    Track-while-scan bird radars are widely used in ornithological studies, but often the precise detection capabilities of these systems are unknown. Quantification of radar performance is essential to avoid observational biases, which requires practical methods for validating a radar's detection capability in specific field settings. In this study a method to quantify the detection capability of a bird radar is presented, as well a demonstration of this method in a case study. By time-referencing line-transect surveys, visually identified birds were automatically linked to individual tracks using their transect crossing time. Detection probabilities were determined as the fraction of the total set of visual observations that could be linked to radar tracks. To avoid ambiguities in assigning radar tracks to visual observations, the observer's accuracy in determining a bird's transect crossing time was taken into account. The accuracy was determined by examining the effect of a time lag applied to the visual observations on the number of matches found with radar tracks. Effects of flight altitude, distance, surface substrate and species size on the detection probability by the radar were quantified in a marine intertidal study area. Detection probability varied strongly with all these factors, as well as species-specific flight behaviour. The effective detection range for single birds flying at low altitude for an X-band marine radar based system was estimated at ~1.5 km. Within this range the fraction of individual flying birds that were detected by the radar was 0.50 ± 0.06 with a detection bias towards higher flight altitudes, larger birds and high tide situations. Besides radar validation, which we consider essential when quantification of bird numbers is important, our method of linking radar tracks to ground-truthed field observations can facilitate species-specific studies using surveillance radars. The methodology may prove equally useful for optimising

  8. Distribution of mycosporine-like amino acids along a surface water meridional transect of the Atlantic.

    Science.gov (United States)

    Llewellyn, Carole A; White, Daniel A; Martinez-Vincente, Victor; Tarran, Glen; Smyth, Tim J

    2012-08-01

    The composition and abundance of mycosporine-like amino acids (MAAs) were investigated in the surface waters along a 13,000-km meridional transect (52° N to 45° S) in the Atlantic Ocean (Atlantic Meridional Transect programme: Cruise AMT 18: 4/10/2008-10/11/2008). MAAs were ubiquitous along the transect, although the composition of the MAAs was variable. Highest concentrations were in the far south (below 40° S; MAA >1 μg L(-1)) and in north subtropical equatorial region (NER: 0-25° N; MAA up to 0.8 μg L(-1)). Highest MAA relative to chlorophyll-a occurred in the NER (MAA/chl-a ratio between 2 and 5). MAA/chl-a significantly correlated with the preceding month's mean daily UV dose and with UV-B/UV-A. In the far south, high MAA concentrations coincided with high phytoplankton biomass, high nutrients and a deep mixed layer associated with the austral spring. Here, the phytoplankton community was dominated by micro- and nano-eukaryotes. At the NER, the high MAA/chl-a coincided with low nutrient concentrations, a shallow mixed layer depth (20-70 m) and to a lesser extent to a shallow nitracline (40-90 m). Here, the phytoplankton consisted primarily of picophytoplankton (0-0.2 μm), dominated by the pico-cyanobacteria Synechococcus sp. and Prochlorococcus sp. and by the nitrogen fixing filamentous cyanobacterium Trichodesmium. The low nitrate concentrations (<0.1 μmol L(-1)) at the NER suggest that nitrogen fixation was required for MAA production. Specific MAAs could not easily be assigned to particular groups of phytoplankton and we could not rule out the possibility that MAAs were associated with symbiotic cyanobacteria contained within heterotrophic dinoflagellates or diatoms.

  9. A floristic survey of the Hyrcanian forests in Northern Iran, using two lowland-mountain transects

    Institute of Scientific and Technical Information of China (English)

    Alireza Naqinezhad; Hassan Zare-Maivan; Hamid Gholizadeh

    2015-01-01

    We investigated the floristic composition of the Hyrcanian forests and the related forest-steppe ecotone in Northern Iran by using two long ecological transects, from lowland to upper mountain areas. The study was conducted during 2008 and 2009 and yielded the identification of 395 plant taxa belonging to 233 genera and 78 families. Dicots with 300 taxa were the richest groups of the flora, followed by monocots with 75 taxa, pteridophytes with 18 species, and gymnosperms with two species. The largest families were Asteraceae (33 taxa); Rosaceae (32 taxa); and Poa-ceae (30 taxa), and the most diverse genera included Carex (15 taxa); Alchemilla (7 taxa); and Poa, Geranium and Acer (6 taxa each). Hemicryptophytes were the most dominant life forms in the area (40%); followed by geo-phytes (31.4%); phanerophytes (15.4%); therophytes (11.4%);and chamaephytes (1.8%). Phytogeographically, Euro-Siberian/Irano-Turanian elements (86 taxa, 21.8%) and Euro-Siberian elements (85 taxa, 21.5%) were the most common chorotypes in the area. Out of 395 taxa, 66 taxa (16.7%) were endemics and subendemics in Iran, of which 26 taxa were exclusively endemics of Iran. According to the IUCN Red List Categories, 48 threatened plant taxa were found in the study area. Plant diversity, life form, and chorotypes in the current study were compared with similar transect studies in other areas of the Hyrcanian forests and in different altitudinal belts, using Sørenson similarity indices. Floristic composition of the surveyed transects demonstrated almost 50% similarity between them.

  10. Harpagoside: from Kalahari Desert to pharmacy shelf.

    Science.gov (United States)

    Georgiev, Milen I; Ivanovska, Nina; Alipieva, Kalina; Dimitrova, Petya; Verpoorte, Robert

    2013-08-01

    Harpagoside is an iridoid glycoside that was first isolated from Harpagophytum procumbens (devil's claw, Pedaliaceae), a medicinal plant in which it is the major constituent of the iridoid pool. Both the pure compound and devil's claw extracts have potent anti-rheumatic, anti-inflammatory and analgesic effects. According to the European Pharmacopoeia commercial devil's claw products should contain at least 1.2% harpagoside. However, the compound has also been isolated from several other plant species and in vitro plant culture systems. Recent advances in knowledge of harpagoside distribution, biosynthesis/accumulation and pharmacology are summarized in this review. We also discuss the possible synergism and/or antagonism between major constituents in harpagoside-containing phytopharmaceutical products. Finally, future perspectives for its potential application are highlighted.

  11. Nitrogen fixation in sediments along a depth transect through the Peruvian oxygen minimum zone

    OpenAIRE

    Gier, Jessica; Sommer, Stefan; Carolin R Löscher; Dale, Andrew W.; Schmitz, Ruth A.; Treude, Tina

    2016-01-01

    The potential coupling of nitrogen (N2) fixation and sulfate reduction (SR) was explored in sediments of the Peruvian oxygen minimum zone (OMZ). Sediment samples were retrieved by a multiple corer at six stations along a depth transect (70–1025 m water depth) at 12° S, covering anoxic and hypoxic bottom water conditions. Benthic N2 fixation, determined by the acetylene reduction assay, was detected at all sites, with highest rates between 70 and 253 m and lower rates at grea...

  12. Retinal glutamate transporter changes in experimental glaucoma and after optic nerve transection in the rat.

    Science.gov (United States)

    Martin, Keith R G; Levkovitch-Verbin, Hana; Valenta, Danielle; Baumrind, Lisa; Pease, Mary Ellen; Quigley, Harry A

    2002-07-01

    High levels of glutamate can be toxic to retinal ganglion cells. Effective buffering of extracellular glutamate by retinal glutamate transporters is therefore important. This study was conducted to investigate whether glutamate transporter changes occur with two models of optic nerve injury in the rat. Glaucoma was induced in one eye of 35 adult Wistar rats by translimbal diode laser treatment to the trabecular meshwork. Twenty-five more rats underwent unilateral optic nerve transection. Two glutamate transporters, GLAST (EAAT-1) and GLT-1 (EAAT-2), were studied by immunohistochemistry and quantitative Western blot analysis. Treated and control eyes were compared 3 days and 1, 4, and 6 weeks after injury. Optic nerve damage was assessed semiquantitatively in epoxy-embedded optic nerve cross sections. Trabecular laser treatment resulted in moderate intraocular pressure (IOP) elevation in all animals. After 1 to 6 weeks of experimental glaucoma, all treated eyes had significant optic nerve damage. Glutamate transporter changes were not detected by immunohistochemistry. Western blot analysis demonstrated significantly reduced GLT-1 in glaucomatous eyes compared with control eyes at 3 days (29.3% +/- 6.7%, P = 0.01), 1 week (55.5% +/- 13.6%, P = 0.02), 4 weeks (27.2% +/- 10.1%, P = 0.05), and 6 weeks (38.1% +/- 7.9%, P = 0.01; mean reduction +/- SEM, paired t-tests, n = 5 animals per group, four duplicate Western blot analyses per eye). The magnitude of the reduction in GLT-1 correlated significantly with mean IOP in the glaucomatous eye (r(2) = 0.31, P = 0.01, linear regression). GLAST was significantly reduced (33.8% +/- 8.1%, mean +/- SEM) after 4 weeks of elevated IOP (P = 0.01, paired t-test, n = 5 animals per group). In contrast to glaucoma, optic nerve transection resulted in an increase in GLT-1 compared with the control eye (P = 0.01, paired t-test, n = 15 animals). There was no significant change in GLAST after transection. GLT-1 and GLAST were significantly

  13. Global coverage of cetacean line-transect surveys: status quo, data gaps and future challenges.

    Science.gov (United States)

    Kaschner, Kristin; Quick, Nicola J; Jewell, Rebecca; Williams, Rob; Harris, Catriona M

    2012-01-01

    Knowledge of abundance, trends and distribution of cetacean populations is needed to inform marine conservation efforts, ecosystem models and spatial planning. We compiled a geo-spatial database of published data on cetacean abundance from dedicated visual line-transect surveys and encoded >1100 abundance estimates for 47 species from 430 surveys conducted worldwide from 1975-2005. Our subsequent analyses revealed large spatial, temporal and taxonomic variability and gaps in survey coverage. With the exception of Antarctic waters, survey coverage was biased toward the northern hemisphere, especially US and northern European waters. Overall, cetacean conservation efforts.

  14. A process flood typology along an Alpine transect: analysis based on observations and modelling approaches

    Science.gov (United States)

    Zoccatelli, Davide; Parajka, Juraj; Gaál, Ladislav; Blöschl, Günter; Borga, Marco

    2014-05-01

    Understanding the effects of climate changes on river floods requires a better understanding of the control of climate variability on flood regimes. The aim of this work is to identify the process types of causative mechanisms of floods along a longitudinal Alpine transect spanning 200 km from Verona in Italy to lower Germany. The investigation is focused on the analysis of the statistical properties of the various flood typologies, their spatial organization and their relation with the topography of the transect. Along the transect, 34 basins were selected following criteria of basin size (between 50 and 500 km2), amount of hydrometeorological data available and impact of hydraulic structures on runoff regime. Around 20 years of hourly data of discharge, precipitation and temperature were collected for each basin. The three most intense floods occurred each year are considered in the work. Precipitation and temperature follow a sharp gradient across the transect, with both precipitation and temperature low around the main alpine ridge. Four flood types are considered: long-rain floods, flash floods, rain-on-snow floods, and snowmelt floods. For the classification we use a combination of a number of process indicators, including the timing of the floods, storm duration, rainfall depths, snowmelt contribution to runoff, initial catchment state and runoff response dynamics, using a procedure similar to what described in Merz and Blöschl (2003). The indicators for flood classification are derived based on either observed discharge data and model results. Comparison between the two derived flood classifications allows one to analyse the viability of using a model approach to build flood typologies in basins characterized by varying data availability. Finally, a sensitivity analysis is carried out by imposing step changes to the precipitation and temperature pattern. The resulting distribution of flood types gives an insight on the possible change in floods

  15. Wetting heterogeneity in mixed-wet porous media controls flow dissipation

    CERN Document Server

    Murison, Julie; Baret, Jean-Christophe; Herminghaus, Stephan; Schröter, Matthias; Brinkmann, Martin

    2013-01-01

    Wettability is crucial for multiphase flow in porous media. However, the effect of spatial distribution of wetting domains has previously only been dealt with by averaging contact angles over several pores. By preparing tailored bead packings with the same average surface wettability, but differing in the typical spatial extension of the same-type wetting domains, we show that models based solely on averages do not capture the dynamics of two phase flow in such systems. Using X-ray tomography we measure the typical length scale xi of the wetting domains in our samples. In capillary pressure saturation (CPS) experiments we find that xi controls the width of the hysteresis loop for xi <= d, d being the bead diameter. X-Ray tomography of the samples during both water and oil invasion shows that the front morphology is smoothened at small values of xi. Both observations are consistent with an increase of dissipation for small correlation length.

  16. Control wetting state transition by micro-rod geometry

    Science.gov (United States)

    He, Yang; Jiang, Chengyu; Wang, Shengkun; Yin, Hengxu; Yuan, Weizheng

    2013-11-01

    Understanding the effect of micro-structure geometry on wetting state transition is important to design and control surface wettability. Micro-rod model was proposed and the relationship between micro-rod geometry and wetting state was investigated in the paper taking into account only the surface roughness and neglecting the chemistry interaction. Micro-rods with different geometric parameters were fabricated using micro-fabrication technology. Their contact angles were measured and compared with theoretical ones. The experimental results indicated that increasing the height and decreasing the space of micro-rod may result in Cassie wetting state, while decreasing the height and increasing the space may result in Wenzel wetting state. A suspended wetting state model due to scallops was proposed. The wetting state transition was interpreted by intruding height, de-pinning and sag mechanism. It may offer a facile way to control the surface wetting state transition by changing the geometry of micro-rod.

  17. Potential of human dental stem cells in repairing the complete transection of rat spinal cord

    Science.gov (United States)

    Yang, Chao; Li, Xinghan; Sun, Liang; Guo, Weihua; Tian, Weidong

    2017-04-01

    Objective. The adult spinal cord of mammals contains a certain amount of neural precursor cells, but these endogenous cells have a limited capacity for replacement of lost cells after spinal cord injury. The exogenous stem cells transplantation has become a therapeutic strategy for spinal cord repairing because of their immunomodulatory and differentiation capacity. In addition, dental stem cells originating from the cranial neural crest might be candidate cell sources for neural engineering. Approach. Human dental follicle stem cells (DFSCs), stem cells from apical papilla (SCAPs) and dental pulp stem cells (DPSCs) were isolated and identified in vitro, then green GFP-labeled stem cells with pellets were transplanted into completely transected spinal cord. The functional recovery of rats and multiple neuro-regenerative mechanisms were explored. Main results. The dental stem cells, especially DFSCs, demonstrated the potential in repairing the completely transected spinal cord and promote functional recovery after injury. The major involved mechanisms were speculated below: First, dental stem cells inhibited the expression of interleukin-1β to reduce the inflammatory response; second, they inhibited the expression of ras homolog gene family member A (RhoA) to promote neurite regeneration; third, they inhibited the sulfonylurea receptor1 (SUR-1) expression to reduce progressive hemorrhagic necrosis; lastly, parts of the transplanted cells survived and differentiated into mature neurons and oligodendrocytes but not astrocyte, which is beneficial for promoting axons growth. Significance. Dental stem cells presented remarkable tissue regenerative capability after spinal cord injury through immunomodulatory, differentiation and protection capacity.

  18. Differential gene expression profiling and biological process analysis in proximal nerve segments after sciatic nerve transection.

    Science.gov (United States)

    Li, Shiying; Liu, Qianqian; Wang, Yongjun; Gu, Yun; Liu, Dong; Wang, Chunming; Ding, Guohui; Chen, Jianping; Liu, Jie; Gu, Xiaosong

    2013-01-01

    After traumatic injury, peripheral nerves can spontaneously regenerate through highly sophisticated and dynamic processes that are regulated by multiple cellular elements and molecular factors. Despite evidence of morphological changes and of expression changes of a few regulatory genes, global knowledge of gene expression changes and related biological processes during peripheral nerve injury and regeneration is still lacking. Here we aimed to profile global mRNA expression changes in proximal nerve segments of adult rats after sciatic nerve transection. According to DNA microarray analysis, the huge number of genes was differentially expressed at different time points (0.5 h-14 d) post nerve transection, exhibiting multiple distinct temporal expression patterns. The expression changes of several genes were further validated by quantitative real-time RT-PCR analysis. The gene ontology enrichment analysis was performed to decipher the biological processes involving the differentially expressed genes. Collectively, our results highlighted the dynamic change of the important biological processes and the time-dependent expression of key regulatory genes after peripheral nerve injury. Interestingly, we, for the first time, reported the presence of olfactory receptors in sciatic nerves. Hopefully, this study may provide a useful platform for deeply studying peripheral nerve injury and regeneration from a molecular-level perspective.

  19. Utility of Glissonean Pedicle Transection for Surgical Treatment of Severe Liver Trauma

    Directory of Open Access Journals (Sweden)

    Satoshi Koizumi

    2017-04-01

    Full Text Available The most common initial strategy for treatment of severe liver trauma is damage control in which hemostasis is achieved by perihepatic gauze packing and/or vascular embolization. However, we encounter patients in whom this strategy alone is not adequate. We have applied the principles of Glissonean pedicle transection, a technique that was originally devised to ensure safe and quick performance of planned hepatectomy for liver cancer, to 3 cases of severe liver trauma. We performed Glissonean pedicle ligation during damage control surgery in 2 patients and Glissonean pedicle transection during the definitive surgery in 1 patient. We describe the approaches and our experience with them, including operation times and outcomes. From our experience thus far, it seems that 8–12 h after the damage control procedure is appropriate for performing the definitive surgery. Although there are some problems posed by this strategy and cases to which it will not be applicable, the method seems to be particularly useful for cases of severe liver trauma in which the damage is extensive and involves the Glissonean pedicles near the hepatic hilus. We describe our 3 cases in detail and review our experience in light of the available literature.

  20. Ketoprofen combined with artery graft entubulization improves functional recovery of transected peripheral nerves.

    Science.gov (United States)

    Mohammadi, Rahim; Mehrtash, Moein; Nikonam, Nima; Mehrtash, Moied; Amini, Keyvan

    2014-12-01

    The objective was to assess the local effect of ketoprofen on sciatic nerve regeneration and functional recovery. Eighty healthy male white Wistar rats were randomized into four experimental groups of 20 animals each: In the transected group (TC), the left sciatic nerve was transected and nerve cut ends were fixed in the adjacent muscle. In the treatment group the defect was bridged using an artery graft (AG/Keto) filled with 10 microliter ketoprofen (0.1 mg/kg). In the artery graft group (AG), the graft was filled with phosphated-buffer saline alone. In the sham-operated group (SHAM), the sciatic nerve was exposed and manipulated. Each group was subdivided into four subgroups of five animals each and regenerated nerve fibres were studied at 4, 8, 12 and 16 weeks post operation. Behavioural testing, sciatic nerve functional study, gastrocnemius muscle mass and morphometric indices showed earlier regeneration of axons in AG/Keto than in AG group (p ketoprofen improved functional recovery and morphometric indices of the sciatic nerve. Local usage of this easily accessible therapeutic medicine is cost saving and avoids the problems associated with systemic administration.

  1. Vegetation Cover based on Eagleson's Ecohydrological Optimality in Northeast China Transect (NECT)

    Science.gov (United States)

    Cong, Z.; Mo, K.; Qinshu, L.; Zhang, L.

    2016-12-01

    Vegetation is considered as the indicator of climate, thus the study of vegetation growth and distribution is of great importance to cognize the ecosystem construction and functions. Vegetation cover is used as an important index to describe vegetation conditions. In Eagleson's ecohydrological optimality, the theoretical optimal vegetation cover M* can be estimated by solving water balance equations. In this study, the theory is applied in the Northeast China Transect (NECT), one of International Geosphere-Biosphere Programs (IGBP) terrestrial transects. The spatial distribution of actual vegetation cover M, which is derived from Normalized Vegetation Index (NDVI) from Moderate-resolution Imaging Spectroradiometer (MODIS), shows that there is a significant gradient ranging from 1 in the east forests to 0 in the west desert. The result indicates that the theoretical M* fits the actual M well (for forest, M* = 0.822 while M = 0.826; for grassland, M* = 0.353 while M = 0.352; the correlation coefficient between M and M* is 0.81). The reasonable calculated proportion of water balance components further demonstrates the applicability of the ecohydrological optimality theory. M* increases with the increase of LAI, leaf angle, stem fraction and temperature, and decreases with the increase of precipitation amount. This method offers the possibility to analyze the impacts of climate change to vegetation cover quantitatively, thus providing advices for eco-restoration projects.

  2. Transecting versus avoiding incision of the anterior placenta previa during cesarean delivery.

    Science.gov (United States)

    Verspyck, Eric; Douysset, Xavier; Roman, Horace; Marret, Stephane; Marpeau, Loïc

    2015-01-01

    To compare maternal outcomes after transection and after avoiding incision of the anterior placenta previa during cesarean delivery. In a retrospective study, records were reviewed for women who had anterior placenta previa and delivered by cesarean after 24 weeks of pregnancy at a tertiary center in Rouen, France. During period A (January 2000 to December 2006), the protocol was to systematically transect the placenta when it was unavoidable. During period B (January 2007 to December 2010), the technique was to avoid incision by circumventing the placenta and passing a hand around its margin. Logistic regression was used to identify independent risk factors associated with maternal transfusion of packed red blood cells. Eighty-four women were included (period A: n=43; period B: n=41). During period B, there was a reduction in frequency of intraoperative hemorrhage (>1000 mL) (P=0.02), intraoperative hemoglobin loss (P=0.005), and frequency of blood transfusion (P=0.02) as compared with period A. In multivariable analysis, period B was associated with a reduced risk of maternal transfusion (odds ratio 0.27; 95% confidence interval 0.09-0.82; P=0.02). Avoiding incision of the anterior placenta previa was found to reduce frequency of maternal blood transfusion during or after cesarean delivery. Copyright © 2014 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.

  3. Gravity Transects across the Karonga Fault in the Northern Malawi Rift

    Science.gov (United States)

    Hull, C. D.; Johnson, T.; Chindandali, P. R. N.; Clappe, B.; Dawson, S.; Laó-Dávila, D. A.; Atekwana, E. A.; Abdelsalam, M. G.; Ivey, T.; Nyalugwe, V.; Salima, J.

    2015-12-01

    The Karonga area of northern Malawi is in the hanging wall of the Livingstone border fault. While most of the strain is accommodated along the border fault, recent seismicity and remote sensing studies indicate there is strain accommodation in the hanging wall area. Gravity data were collected along two West-East transects (one in the north and the other in the south) in this region to explore this strain accommodation, locate faults, determine the thickness of sediments on the hanging wall block of the Karonga fault, and to determine the geometry of a Karoo depositional basin. Both profiles extended from the uplifted basements into the rift basin; the northern profile is approximately 30 km in length while the southern profile is 70 km. Both gravity profiles were acquired with a Scintrex CG-5 Autograv using station spacings ranging between 0.5 - 2 km. These gravity transects place constraints on the structural interpretations of the area based on previous fieldwork and remote sensing. This project uses 2.5D forward gravity modeling to test the possibility of the Karonga fault being a single fault in the north while breaking up into multiple faults further south as it responds to the weaknesses created by preexisting structures.

  4. Female rat transcriptome response to infraorbital nerve transection differs from that of males: RNA-seq.

    Science.gov (United States)

    Orczyk, John J; Batka, Richard; Gore, Ashleigh; Maio-Lexa, Michelena; Kulkarni, Akhil; Garraghty, Preston E

    2017-01-01

    The effects of infraorbital nerve (ION) transection on gene expression in the adult female rat barrel cortex were investigated using RNA sequencing. After a 24-hour survival duration, 28 genes were differentially regulated by ION transection. Differentially expressed genes suggest microglial activity, increased retrograde ciliary transport, and a decrease in inhibition. These changes may be functionally comparable to changes in the male barrel cortex, where changes in genes related to morphology, neuronal activity, and neuronal excitability were observed. However, the patterns in changes in gene expression are vastly different between male and female rats. The results strongly caution against the practice of generalizing data from one sex to both sexes. This cautionary note has potentially profound implications for a range of research lines, including substance abuse and stress, both research domains in which subjects have been predominantly males. Future research needs to employ sex as a classification variable, as sex differences can generally be expected. Future research is also needed to confirm that changes in gene expression observed with RNA-seq correlate with changes in protein expression. J. Comp. Neurol. 525:140-150, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  5. Collapse of granular media subjected to wetting

    Directory of Open Access Journals (Sweden)

    El Korchi Fatima Zahra

    2017-01-01

    Full Text Available This paper focuses on the collapse of granular materials subjected to wetting action. For soils, the collapse potential depends on several parameters such as liquid limit, matric suction, compactness, initial water content and the amount of fine particles. The effect of grain size, which plays a key role in the rearrangement of grains, remains little studied and poorly understood. To investigate the capillary origin of the collapse phenomenon, we present an experimental study on macroscopic and local scales. Our results show the effect of grain size and water content on collapse.

  6. Microwave emission from dry and wet snow

    Science.gov (United States)

    Chang, T. C.; Gloersen, P.

    1975-01-01

    A microscopic model was developed to study the microwave emission from snow. In this model, the individual snow particles are considered to be the scattering centers. Mie scattering theory for spherical particles is then used to compute the volume scattering and extinction coefficients of the closely packed scattering spheres, which are assumed not to interact coherently. The results of the computations show significant volume scattering effects in the microwave region which result in low observed emissivities from cold, dry snow. In the case of wet snow, the microwave emissivities are increased considerably, in agreement with earlier experimental observations in which the brightness temperatures have increased significantly at the onset of melting.

  7. Phoenix Carries Soil to Wet Chemistry Lab

    Science.gov (United States)

    2008-01-01

    This image taken by the Surface Stereo Imager on NASA's Phoenix Mars Lander shows the lander's Robotic Arm scoop positioned over the Wet Chemistry Lab delivery funnel on Sol 29, the 29th Martian day after landing, or June 24, 2008. The soil will be delivered to the instrument on Sol 30. This image has been enhanced to brighten the scene. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  8. Stable, Electroinactive Wetting Agent For Fuel Cells

    Science.gov (United States)

    Prakash, Surya G.; Olah, George A.; Narayanan, Sekharipuram R.; Surampudi, Subbarao; Halpert, Gerald

    1994-01-01

    Straight-chain perfluorooctanesulfonic acid (C8 acid) identified as innocuous and stable wetting agent for use with polytetrafluoroethylene-containing electrodes in liquid-feed direct-oxidation fuel cells suggested for use in vehicles and portable power supplies. C8 acid in small concentrations in aqueous liquid solutions of methanol, trimethoxymethane, dimethoxymethane, and trioxane enables oxidation of these substances by use of commercially available electrodes of type designed originally for use with gases. This function specific to C8 acid molecule and not achieved by other related perfluorolkanesulfonic acids.

  9. Cross-continental comparison of the functional composition and carbon allocation of two altitudinal forest transects in Ecuador and Rwanda.

    Science.gov (United States)

    Verbeeck, Hans; Bauters, Marijn; Bruneel, Stijn; Demol, Miro; Taveirne, Cys; Van Der Heyden, Dries; Kearsley, Elizabeth; Cizungu, Landry; Boeckx, Pascal

    2017-04-01

    Tropical forests are key actors in the global carbon cycle. Predicting future responses of these forests to global change is challenging, but important for global climate models. However, our current understanding of such responses is limited, due to the complexity of forest ecosystems and the slow dynamics that inherently form these systems. Our understanding of ecosystem ecology and functioning could greatly benefit from experimental setups including strong environmental gradients in the tropics, as found on altitudinal transects. We setup two such transects in both South-America and Central Africa, focussing on shifts in carbon allocation, forest structure, nutrient cycling and functional composition. The Ecuadorian transect has 16 plots (40 by 40 m) and ranges from 400 to 3000 m.a.s.l., and the Rwandan transect has 20 plots (40 by 40 m) from 1500 to 3000 m.a.s.l. All plots were inventoried and canopy, litter and soil were extensively sampled. By a cross-continental comparison of both transects, we will gain insight in how different or alike both tropical forests biomes are in their responses, and how universal the observed altitudinal adaption mechanisms are. This could provide us with vital information of the ecological responses of both biomes to future global change scenarios. Additionally, comparison of nutrient shifts and trait-based functional composition allows us to compare the biogeochemical cycles of African and South-American tropical forests.

  10. A wetting and drying scheme for ROMS

    Science.gov (United States)

    Warner, John C.; Defne, Zafer; Haas, Kevin; Arango, Hernan G.

    2013-01-01

    The processes of wetting and drying have many important physical and biological impacts on shallow water systems. Inundation and dewatering effects on coastal mud flats and beaches occur on various time scales ranging from storm surge, periodic rise and fall of the tide, to infragravity wave motions. To correctly simulate these physical processes with a numerical model requires the capability of the computational cells to become inundated and dewatered. In this paper, we describe a method for wetting and drying based on an approach consistent with a cell-face blocking algorithm. The method allows water to always flow into any cell, but prevents outflow from a cell when the total depth in that cell is less than a user defined critical value. We describe the method, the implementation into the three-dimensional Regional Oceanographic Modeling System (ROMS), and exhibit the new capability under three scenarios: an analytical expression for shallow water flows, a dam break test case, and a realistic application to part of a wetland area along the Georgia Coast, USA.

  11. The Underlying Physics in Wetted Particle Collisions

    Science.gov (United States)

    Donahue, Carly; Hrenya, Christine; Davis, Robert

    2008-11-01

    Wetted granular particles are relevant in many industries including the pharmaceutical and chemical industries and has applications to granulation, filtration, coagulation, spray coating, drying and pneumatic transport. In our current focus, we investigate the dynamics of a three-body normal wetted particle collision. In order to conduct collisions we use an apparatus called a ``Stokes Cradle,'' similar to the Newton's Cradle (desktop toy) except that the target particles are covered with oil. Here, we are able to vary the oil thickness, oil viscosity, and material properties. With a three particle collision there are four possible outcomes: fully agglomerated (FA); Newton's Cradle (NC), the striker and the first target ball are agglomerated and the last target ball is separated; Reverse Newton's Cradle (RNC), the striker is separated and the two targets are agglomerated; and fully separated (FS). Varying the properties of the collisions, we have observed all four outcomes. We use elastohydrodynamics as a theoretical basis for modeling the system. We also have considered the glass transition of the oil as the pressure increases upon impact and the cavitation of the oil as the pressure drops below the vapor pressure upon rebound. A toy model has been developed where the collision is modeled as a series of two-body collisions. A qualitative agreement between the toy model and experiments gives insight into the underlying physics.

  12. Wenzel Wetting on Slippery Rough Surfaces

    Science.gov (United States)

    Stogin, Birgitt; Dai, Xianming; Wong, Tak-Sing

    2015-11-01

    Liquid repellency is an important surface property used in a wide range of applications including self-cleaning, anti-icing, anti-biofouling, and condensation heat transfer, and is characterized by apparent contact angle (θ*) and contact angle hysteresis (Δθ*). The Wenzel equation (1936) predicts θ* of liquids in the Wenzel state, and is one of the most fundamental equations in the wetting field. However, droplets in the Wenzel state on conventional rough surfaces exhibit large Δθ* , making it difficult to experimentally verify the model with precision. As a result, precise verification of the Wenzel wetting model has remained an open scientific question for the past 79 years. Here we introduce a new class of liquid-infused surfaces called slippery rough surfaces -- surfaces with significantly reduced Δθ* compared to conventional rough surfaces--and use them to experimentally assess the Wenzel equation with the highest precision to date. We acknowledge the funding support by National Science Foundation (NSF) CAREER Award #: 1351462 and Office of Navy Research MURI Award #: N00014-12-1-0875. Stogin acknowledges the support from the NSF Graduate Research Fellowship (Grant No. DGE1255832).

  13. Wet sipping system at Wolsong-1

    Energy Technology Data Exchange (ETDEWEB)

    Park, J.Y.; Shin, J.C.; Kim, Y.C.; Park, C.H.; Choi, T.Y.; Park, C.J., E-mail: jyoulpark@knfc.co.kr [Korea Nuclear Fuel Co. Ltd. (KNF), Yousong, Daejeon (Korea, Republic of); Manger, A.M. [Atomic Energy of Canada Limited, Mississauga, Ontario (Canada)

    2010-07-01

    After many years of operation, the on-power failed fuel detection and location systems along with alarm area gamma monitors at Wolsong-1 have successfully demonstrated that most, if not all, defective and suspect fuel bundles can be located before discharge to the fuel bay. Today, discharged bundles are now being transferred from the fuel bay to the AECL designed Modular Air-Cooled Storage (MACSTOR) canister facilities. Since these canisters are licensed for storing intact fuel bundles only, a procedure was needed at Wolsong-1 to separate any suspect or defective bundles that do not release fission products in detectable quantities. Therefore, KNF designed and built a wet sipper to enclose an irradiated bundle inside a sealed container at the bottom of the fuel bay. Various techniques were then used to enhance the release of water soluble fission products from defective fuel elements before circulating water samples from the immediate vicinity of an irradiated fuel bundle to an inspection station located at the top of the fuel bay. Any water samples with elevated levels of gamma activity were direct indications of a fuel cladding breach. The presence of defective fuel elements were then verified by visual inspection. The system performance test was performed in the Wolsong-1 nuclear power plant on March 2009.This paper describes the results of the wet sipping tests. (author)

  14. WetLab-2: Wet Lab RNA SmartCycler Providing PCR Capability on ISS

    Science.gov (United States)

    Parra, Macarena; Schonfeld, Julie

    2015-01-01

    The WetLab-2 system will provide sample preparation and qRT-PCR analysis on-board the ISS, a capability to enable using the ISS as a real laboratory. The system will be validated on SpX-7, and is planned for its first PI use on SpX-9.

  15. Droplet activation of wet particles: development of the Wet CCN approach

    Science.gov (United States)

    Nakao, S.; Suda, S. R.; Camp, M.; Petters, M. D.; Kreidenweis, S. M.

    2014-07-01

    Relationships between critical supersaturation required for activation and particle dry diameter have been the primary means for experimentally characterizing cloud condensation nuclei (CCN) activity; however, use of the dry diameter inherently limits the application to cases where the dry diameter can be used to accurately estimate solute volume. This study challenges the requirement and proposes a new experimental approach, Wet CCN, for studying CCN activity without the need for a drying step. The new approach directly measures the subsaturated portion of the Köhler curves. The experimental setup consists of a humidity-controlled differential mobility analyzer and a CCN counter; wet diameter equilibrated at known relative humidity is used to characterize CCN activity instead of the dry diameter. The experimental approach was validated against ammonium sulfate, glucose, and nonspherical ammonium oxalate monohydrate. Further, the approach was applied to a mixture of nonspherical iodine oxide particles. The Wet CCN approach successfully determined the hygroscopicity of nonspherical particles by collapsing them into spherical, deliquesced droplets. We further show that the Wet CCN approach offers unique insights into the physical and chemical impacts of the aqueous phase on CCN activity; a potential application is to investigate the impact of evaporation/co-condensation of water-soluble semivolatile species on CCN activity.

  16. Droplet activation of wet particles: development of the Wet CCN approach

    Directory of Open Access Journals (Sweden)

    S. Nakao

    2014-01-01

    Full Text Available Relationships between critical supersaturation required for activation and particle dry diameter have been the primary means for experimentally characterizing cloud condensation nuclei (CCN activity; however, use of the dry diameter inherently limits the application to cases where the dry diameter can be used to accurately estimate solute volume. This study challenges the requirement and proposes a new experimental approach, Wet CCN, for studying CCN activity without the need for a drying step. The new approach directly measures Köhler curves under sub-saturated conditions. The experimental setup consists of a humidity-controlled differential mobility analyzer and a CCN counter; wet diameter equilibrated at known relative humidity is used to characterize CCN activity instead of the dry diameter. The experimental approach was validated against ammonium sulfate, glucose and non-spherical ammonium oxalate monohydrate. Further, the approach was applied to a mixture of non-spherical iodine oxide particles. The Wet CCN approach successfully determined the hygroscopicity of non-spherical particles by collapsing them into spherical, deliquesced droplets. We further show that the Wet CCN approach offers unique insights to the physical and chemical impacts of the aqueous phase on CCN activity; a potential application is to investigate the impact of evaporation/co-condensation of water-soluble semi-volatile species on CCN activity.

  17. Cross-continental comparison of the functional composition and carbon allocation of two altitudinal forest transects in Ecuador and Rwanda.

    Science.gov (United States)

    Bauters, Marijn; Bruneel, Stijn; Demol, Miro; Taveirne, Cys; Van Der Heyden, Dries; Boeckx, Pascal; Kearsley, Elizabeth; Cizungu, Landry; Verbeeck, Hans

    2016-04-01

    Tropical forests are key actors in the global carbon cycle. Predicting future responses of these forests to global change is challenging, but important for global climate models. However, our current understanding of such responses is limited, due to the complexity of forest ecosystems and the slow dynamics that inherently form these systems. Our understanding of ecosystem ecology and functioning could greatly benefit from experimental setups including strong environmental gradients in the tropics, as found on altitudinal transects. We setup two such transects in both South-America and Africa, focussing on shifts in carbon allocation, forest structure and functional composition. By a cross-continental comparison of both transects, we will gain insight in how different or alike both tropical forests biomes are in their responses, and how universal the observed adaption mechanisms are.

  18. Expanding biological data standards development processes for US IOOS: visual line transect observing community for mammal, bird, and turtle data

    Science.gov (United States)

    Fornwall, M.; Gisiner, R.; Simmons, S. E.; Moustahfid, Hassan; Canonico, G.; Halpin, P.; Goldstein, P.; Fitch, R.; Weise, M.; Cyr, N.; Palka, D.; Price, J.; Collins, D.

    2012-01-01

    The US Integrated Ocean Observing System (IOOS) has recently adopted standards for biological core variables in collaboration with the US Geological Survey/Ocean Biogeographic Information System (USGS/OBIS-USA) and other federal and non-federal partners. In this Community White Paper (CWP) we provide a process to bring into IOOS a rich new source of biological observing data, visual line transect surveys, and to establish quality data standards for visual line transect observations, an important source of at-sea bird, turtle and marine mammal observation data. The processes developed through this exercise will be useful for other similar biogeographic observing efforts, such as passive acoustic point and line transect observations, tagged animal data, and mark-recapture (photo-identification) methods. Furthermore, we suggest that the processes developed through this exercise will serve as a catalyst for broadening involvement by the larger marine biological data community within the goals and processes of IOOS.

  19. Doubly Reentrant Cavities Prevent Catastrophic Wetting Transitions on Intrinsically Wetting Surfaces

    KAUST Repository

    Domingues, Eddy

    2017-06-05

    Omniphobic surfaces, i.e. which repel all known liquids, have proven of value in applications ranging from membrane distillation to underwater drag reduction. A limitation of currently employed omniphobic surfaces is that they rely on perfluorinated coatings, increasing cost and environmental impact, and preventing applications in harsh environments. There is, thus, a keen interest in rendering conventional materials, such as plastics, omniphobic by micro/nano-texturing rather than via chemical make-up, with notable success having been achieved for silica surfaces with doubly reentrant micropillars. However, we found a critical limitation of microtextures comprising of pillars that they undergo catastrophic wetting transitions (apparent contact angles, θr → 0° from θr > 90°) in the presence of localized physical damages/defects or on immersion in wetting liquids. In response, a doubly reentrant cavity microtexture is introduced, which can prevent catastrophic wetting transitions in the presence of localized structural damage/defects or on immersion in wetting liquids. Remarkably, our silica surfaces with doubly reentrant cavities could exhibited apparent contact angles, θr ≈ 135° for mineral oil, where the intrinsic contact angle, θo ≈ 20°. Further, when immersed in mineral oil or water, doubly reentrant microtextures in silica (θo ≈ 40° for water) were not penetrated even after several days of investigation. Thus, microtextures comprising of doubly reentrant cavities might enable applications of conventional materials without chemical modifications, especially in scenarios that are prone to localized damages or immersion in wetting liquids, e.g. hydrodynamic drag reduction and membrane distillation.

  20. Doubly Reentrant Cavities Prevent Catastrophic Wetting Transitions on Intrinsically Wetting Surfaces.

    Science.gov (United States)

    Domingues, Eddy M; Arunachalam, Sankara; Mishra, Himanshu

    2017-06-28

    Omniphobic surfaces, that is, which repel all known liquids, have proven of value in applications ranging from membrane distillation to underwater drag reduction. A limitation of currently employed omniphobic surfaces is that they rely on perfluorinated coatings, increasing cost and environmental impact and preventing applications in harsh environments. Thus, there is a keen interest in rendering conventional materials, such as plastics, omniphobic by micro/nanotexturing rather than via chemical makeup, with notable success having been achieved for silica surfaces with doubly reentrant micropillars. However, we found a critical limitation of microtextures comprising pillars that they undergo catastrophic wetting transitions (apparent contact angles, θr → 0° from θr > 90°) in the presence of localized physical damages/defects or on immersion in wetting liquids. In response, a doubly reentrant cavity microtexture is introduced, which can prevent catastrophic wetting transitions in the presence of localized structural damage/defects or on immersion in wetting liquids. Remarkably, our silica surfaces with doubly reentrant cavities could exhibit apparent contact angles, θr ≈ 135° for mineral oil, where the intrinsic contact angle, θo ≈ 20°. Further, when immersed in mineral oil or water, doubly reentrant microtextures in silica (θo ≈ 40° for water) were not penetrated even after several days of investigation. Thus, microtextures comprising doubly reentrant cavities might enable applications of conventional materials without chemical modifications, especially in scenarios that are prone to localized damages or immersion in wetting liquids, for example, hydrodynamic drag reduction and membrane distillation.

  1. Line Transect Surveys Underdetect Terrestrial Mammals: Implications for the Sustainability of Subsistence Hunting.

    Science.gov (United States)

    Fragoso, José M V; Levi, Taal; Oliveira, Luiz F B; Luzar, Jeffrey B; Overman, Han; Read, Jane M; Silvius, Kirsten M

    2016-01-01

    Conservation of Neotropical game species must take into account the livelihood and food security needs of local human populations. Hunting management decisions should therefore rely on abundance and distribution data that are as representative as possible of true population sizes and dynamics. We simultaneously applied a commonly used encounter-based method and an infrequently used sign-based method to estimate hunted vertebrate abundance in a 48,000-km2 indigenous landscape in southern Guyana. Diurnal direct encounter data collected during three years along 216, four-kilometer -long transects consistently under-detected many diurnal and nocturnal mammal species readily detected through sign. Of 32 species analyzed, 31 were detected by both methods; however, encounters did not detect one and under-detected another 12 of the most heavily hunted species relative to sign, while sign under-detected 12 never or rarely collected species relative to encounters. The six most important game animals in the region, all ungulates, were not encountered at 11-40% of village and control sites or on 29-72% of transects where they were detected by sign. Using the sign methodology, we find that tapirs, one of the terrestrial vertebrates considered most sensitive to overexploitation, are present at many sites where they were never visually detected during distance sampling. We find that this is true for many other species as well. These high rates of under-detection suggest that behavioral changes in hunted populations may affect apparent occurrence and abundance of these populations. Accumulation curves (detection of species on transects) were much steeper for sign for 12 of 16 hunted species than for encounters, but that pattern was reversed for 12 of 16 species unhunted in our area. We conclude that collection of sign data is an efficient and effective method of monitoring hunted vertebrate populations that complements encounter and camera-trapping methods in areas impacted by

  2. Line Transect Surveys Underdetect Terrestrial Mammals: Implications for the Sustainability of Subsistence Hunting

    Science.gov (United States)

    Levi, Taal; Oliveira, Luiz F. B.; Luzar, Jeffrey B.; Overman, Han; Read, Jane M.

    2016-01-01

    Conservation of Neotropical game species must take into account the livelihood and food security needs of local human populations. Hunting management decisions should therefore rely on abundance and distribution data that are as representative as possible of true population sizes and dynamics. We simultaneously applied a commonly used encounter-based method and an infrequently used sign-based method to estimate hunted vertebrate abundance in a 48,000-km2 indigenous landscape in southern Guyana. Diurnal direct encounter data collected during three years along 216, four-kilometer -long transects consistently under-detected many diurnal and nocturnal mammal species readily detected through sign. Of 32 species analyzed, 31 were detected by both methods; however, encounters did not detect one and under-detected another 12 of the most heavily hunted species relative to sign, while sign under-detected 12 never or rarely collected species relative to encounters. The six most important game animals in the region, all ungulates, were not encountered at 11–40% of village and control sites or on 29–72% of transects where they were detected by sign. Using the sign methodology, we find that tapirs, one of the terrestrial vertebrates considered most sensitive to overexploitation, are present at many sites where they were never visually detected during distance sampling. We find that this is true for many other species as well. These high rates of under-detection suggest that behavioral changes in hunted populations may affect apparent occurrence and abundance of these populations. Accumulation curves (detection of species on transects) were much steeper for sign for 12 of 16 hunted species than for encounters, but that pattern was reversed for 12 of 16 species unhunted in our area. We conclude that collection of sign data is an efficient and effective method of monitoring hunted vertebrate populations that complements encounter and camera-trapping methods in areas impacted by

  3. Contrasting pH buffering patterns in neutral-alkaline soils along a 3600 km transect in northern China

    Directory of Open Access Journals (Sweden)

    W. Luo

    2015-08-01

    Full Text Available Soil pH buffering capacity (pHBC plays a crucial role in predicting acidification rates, yet its large-scale patterns and controls are poorly understood, especially for neutral-alkaline soils. Here, we evaluated the spatial patterns and drivers of pHBC along a 3600 km long transect (1900 km sub-transect with carbonate containing soils and 1700 km sub-transect with non-carbonate containing soils across northern China. Soil pHBC was greater in the carbonate containing soils than in the non-carbonate containing soils. Acid addition decreased soil pH in the non-carbonate containing soils more markedly than in the carbonate containing soils. Within the carbonate soil sub-transect, soil pHBC was positively correlated with cation exchange capacity (CEC, carbonate content and exchangeable sodium (Na concentration, but negatively correlated with initial pH and clay content, and not correlated with soil organic carbon (SOC content. Within the non-carbonate sub-transect, soil pHBC was positively related to initial pH, clay content, CEC and exchangeable Na concentration, but not related to SOC content. Carbonate content was the primary determinant of pHBC in the carbonate containing soils and CEC was the main determinant of buffering capacity in the non-carbonate containing soils. Soil pHBC was positively related to aridity index and carbonate content across the carbonate containing soil sub-transect. Our results indicated that mechanisms controlling pHBC differ among neutral-alkaline soils of northern China, especially between carbonate and non-carbonate containing soils, leading to different rates, risks, and impacts of acidification. This understanding should be incorporated into the acidification risk assessment and landscape management in a changing world.

  4. Accounting for subgroup structure in line-transect abundance estimates of false killer whales (Pseudorca crassidens in Hawaiian waters.

    Directory of Open Access Journals (Sweden)

    Amanda L Bradford

    Full Text Available For biological populations that form aggregations (or clusters of individuals, cluster size is an important parameter in line-transect abundance estimation and should be accurately measured. Cluster size in cetaceans has traditionally been represented as the total number of individuals in a group, but group size may be underestimated if group members are spatially diffuse. Groups of false killer whales (Pseudorca crassidens can comprise numerous subgroups that are dispersed over tens of kilometers, leading to a spatial mismatch between a detected group and the theoretical framework of line-transect analysis. Three stocks of false killer whales are found within the U.S. Exclusive Economic Zone of the Hawaiian Islands (Hawaiian EEZ: an insular main Hawaiian Islands stock, a pelagic stock, and a Northwestern Hawaiian Islands (NWHI stock. A ship-based line-transect survey of the Hawaiian EEZ was conducted in the summer and fall of 2010, resulting in six systematic-effort visual sightings of pelagic (n = 5 and NWHI (n = 1 false killer whale groups. The maximum number and spatial extent of subgroups per sighting was 18 subgroups and 35 km, respectively. These sightings were combined with data from similar previous surveys and analyzed within the conventional line-transect estimation framework. The detection function, mean cluster size, and encounter rate were estimated separately to appropriately incorporate data collected using different methods. Unlike previous line-transect analyses of cetaceans, subgroups were treated as the analytical cluster instead of groups because subgroups better conform to the specifications of line-transect theory. Bootstrap values (n = 5,000 of the line-transect parameters were randomly combined to estimate the variance of stock-specific abundance estimates. Hawai'i pelagic and NWHI false killer whales were estimated to number 1,552 (CV = 0.66; 95% CI = 479-5,030 and 552 (CV = 1.09; 95% CI = 97

  5. Wetting failure of hydrophilic surfaces promoted by surface roughness

    Science.gov (United States)

    Zhao, Meng-Hua; Chen, Xiao-Peng; Wang, Qing

    2014-06-01

    Wetting failure is of vital importance to many physical phenomena, such as industrial coating and drop emission. Here we show when and how the surface roughness promotes the destabilization of a moving contact line on a hydrophilic surface. Beyond the balance of the driving force and viscous resistance where a stable wetting interface is sustained, wetting failure occurs and is modified by the roughness of the surface. The promoting effect arises only when the wetting velocity is high enough to create a gas-liquid-solid composite interface in the vicinity of the moving contact line, and it is a function of the intrinsic contact angle and proportion of solid tops. We propose a model to explain splashes of rough solid spheres impacting into liquids. It reveals a novel concept that dynamic wetting on hydrophilic rough surfaces can be similar to that on hydrophobic surfaces, and brings a new way to design surfaces with specific wetting properties.

  6. Dynamic wetting with viscous Newtonian and non-Newtonian fluids.

    Science.gov (United States)

    Wei, Y; Rame, E; Walker, L M; Garoff, S

    2009-11-18

    We examine various aspects of dynamic wetting with viscous Newtonian and non-Newtonian fluids. Rather than concentrating on the mechanisms that relieve the classic contact line stress singularity, we focus on the behavior in the wedge flow near the contact line which has the dominant influence on wetting with these fluids. Our experiments show that a Newtonian polymer melt composed of highly flexible molecules exhibits dynamic wetting behavior described very well by hydrodynamic models that capture the critical properties of the Newtonian wedge flow near the contact line. We find that shear thinning has a strong impact on dynamic wetting, by reducing the drag of the solid on the fluid near the contact line, while the elasticity of a Boger fluid has a weaker impact on dynamic wetting. Finally, we find that other polymeric fluids, nominally Newtonian in rheometric measurements, exhibit deviations from Newtonian dynamic wetting behavior.

  7. Mathematical model and general laws of wet compression

    Institute of Scientific and Technical Information of China (English)

    王永青; 刘铭; 廉乐明; 何健勇; 严家騄

    2002-01-01

    Wet compression is an effective way to enhance the performance of gas turbines and it has attracted a good deal of attention in recent years. The one-sidedness and inaccuracy of previous studies,which took concentration gradient as mass transfer potential are discussed. The mass transfer process is analyzed from the viewpoint of non-equilibrium thermodynamics,by taking generalized thermodynamic driving force as mass transfer potential,and the corresponding mass-transfer coefficient is obtained using the heat and mass transfer equilibrium occurring between moist air and water droplets at wet-bulb temperature for the sake of avoiding complex tests and providing more accurate formulas. A mathematical model of wet compression is therefore established,and the general laws of wet compression are investigated. The results show that the performance of atomizer is critical for wet compression and wet compression is more suitable for compressors with higher pressure ratio and longer compression time.

  8. Tympanoplasty: does dry or wet temporalis fascia graft matter?

    Science.gov (United States)

    Singh, G B; Kumar, D; Aggarwal, K; Garg, S; Arora, R; Kumar, S

    2016-08-01

    To evaluate the success rate of dry and wet temporalis fascia grafts in type I underlay tympanoplasty. A prospective, randomised study was conducted. One hundred adult patients (males and females) with chronic suppurative otitis media (mucosal type) were divided into 2 groups of 50 each: one group underwent dry graft tympanoplasty and the other underwent wet graft tympanoplasty. Fibroblast count was calculated in dry and wet grafts. The dry graft and wet graft groups had overall surgical success rates of 82 and 90 per cent, respectively; this finding was not statistically significant. A statistically significant high fibroblast count was observed in wet grafts, but it did not correlate with surgical success. A dry or wet temporalis fascia graft does not influence the outcome of tympanoplasty type I.

  9. Treatment of refractory partial status epilepticus with multiple subpial transection: case report.

    Science.gov (United States)

    D'Giano, C H; Del C García, M; Pomata, H; Rabinowicz, A L

    2001-07-01

    Status epilepticus (SE) represents a medical emergency that annually affects 60,000--150,000 individuals in the United States. Selective neuronal loss in vulnerable areas has been pathologically demonstrated following convulsive SE primarily affecting the limbic system, thalamus and cerebellum. Morbidity in those cases that follow refractory SE (RSE) is poorly documented. There have been anecdotal reports of surgical treatment for this condition, especially secondary to brain lesions. We report a 6-year-old patient who was in RSE for 60 days, without a brain lesion documented by MRI. The patient underwent multiple subpial transection (MST) of the sensorimotor cortex, which by ictal EEG and ictal SPECT proved to be the epileptogenic zone. We conclude that MST should be considered as an alternative treatment for refractory partial SE.

  10. Establishment and evaluation of a rat model of complete transected spinal cord injury

    Institute of Scientific and Technical Information of China (English)

    Xuejun Li; Chunhai Huang; Shangming Liu; Xianrui Yuan

    2008-01-01

    BACKGROUND: The establishment of a rat model of complete transected spinal cord injury lacks technological specifications. The current models lack concordance and reliability, and the death rate of the experimental animals is high. Therefore, there is a great need for a reliable model to apply clinical applications of therapy.OBJECTIVE: To construct a rat model of complete transected spinal cord injury characterized by stability, reproducibility, and a high animal survival rate. DESIGN: Completely randomized controlled study.SETTING: Department of Neurosurgery, Xiangya Hospital of Central South University.MATERIALS: Fifty-five healthy specific pathogen free grade adult female Sprague Dawley rats were provided by the Experimental Animal Department, Xiangya Medical College, Central South University. Olympus BX51 imaging collecting analytic system was provided by Olympus Company, Japan; and SEN-7203 Nihon-Kohden electrical stimulator by Nihon Kohden, Japan. METHODS: This study was performed at the Laboratory of Neurosurgery, Xiangya Hospital of Central South University from April to June 2006. Experimental grouping: 55 rats were randomly divided into model group (n = 40) and sham surgery group (n = 15). In the model group, a self-made sliver hook was passed through the ventral side to support the spinal cord at the T12 segment and to shear it off. A complete transected spinal cord, 2 mm in length, was resected. In the sham surgery group, the spinal cord was identically exposed. The dura mater of the spinal cord was cut open, but the spinal cord was not damaged. MAIN OUTCOME MEASURES: Histopathological changes after spinal cord injury at L2 segment were observed subsequent to hematoxylin and eosin staining under optical microscopy. Olympus BX51 imaging collecting analytic system was used to count spinal cord ventral horn neurons. Motor function of rat hindlimb was evaluated with the Basso, Beattie and Bresnahan (BBB) scale. Paraplegia was evaluated as 0 point, and

  11. Jejunal tackle: a case report of complete jejunal transection in rugby union.

    Science.gov (United States)

    Perry, William; Fischer, Jesse; Wakeman, Christopher

    2014-09-01

    Jejunal perforation as a result of blunt abdominal trauma during sport is particularly rare. We are aware of 6 reported cases of jejunal perforation in sport: 1 in hockey, 2 in football (soccer), and 3 in American football. This report presents the case of a 25-year-old professional rugby union player, who presented to an "After Hours" general practice clinic with increasing central abdominal and epigastric pain after a heavy tackle during an international match in New Zealand. Despite suffering complete jejunal transection, the patient continued to play on, only presenting to an After Hours general practice clinic 3 hours after the injury. The case demonstrates the remarkable physiological resilience of professional rugby players and acts as a reminder to maintain a high degree of suspicion for small bowel injury despite normal vital signs in healthy young patients with abdominal pain secondary to blunt trauma.

  12. Image processing methods to elucidate spatial characteristics of retinal microglia after optic nerve transection.

    Science.gov (United States)

    Zhang, Yudong; Peng, Bo; Wang, Shuihua; Liang, Yu-Xiang; Yang, Jiquan; So, Kwok-Fai; Yuan, Ti-Fei

    2016-02-18

    Microglia are the mononuclear phagocytes with various functions in the central nervous system, and the morphologies of microglia imply the different stages and functions. In optical nerve transection model of the retina, the retrograde degeneration of retinal ganglion cells induces microglial activations to a unique morphology termed rod microglia. A few studies described the rod microglia in the cortex and retina; however, the spatial characteristic of rod microglia is not fully understood. In this study, we built a mathematical model to characterize the spatial trait of rod microglia. In addition, we developed a Matlab-based image processing pipeline that consists of log enhancement, image segmentation, mathematical morphology based cell detection, area calculation and angle analysis. This computer program provides researchers a powerful tool to quickly analyze the spatial trait of rod microglia.

  13. Pollen-rain-vegetation relationships along a forest-savanna transect in southeastern Cameroon.

    Science.gov (United States)

    Vincens; Dubois; Guillet; Achoundong; Buchet; Kamgang Kabeyene Beyala V; de Namur C; Riera

    2000-07-01

    Modern soil and litter samples from southeastern Cameroon, collected along a continuous forest-savanna transect were analysed for pollen content to define modern pollen-vegetation relationships. The pollen results, completed and compared with botanical inventories, leaf area index and basal area measurements performed in the same area, clearly registered the physiognomy, the main floristic composition and floral richness of the two sampled ecosystems. Distortions were observed between sampled vegetations and their pollen rain, related to important differences in pollen production and dispersal of plant species: this is a general feature in many tropical regions. The pollen data in the area studied reflected well the recent transgression of forest versus savanna. This permitted us to define inside the forest ecosystem more successional vegetation communities than the botanical surveys allowed.

  14. Crustal transects across the Rif domains in North Morocco, from the RIFSIS seismic survey

    Science.gov (United States)

    Gil de la Iglesia, A.; Gallart, J.; Diaz Cusi, J.; Carbonell, R.; Levander, A.; Palomeras, I.; Harnafi, M.

    2013-12-01

    In October 2011, two 300 km-long NS and EW wide-angle seismic transects were carried out in N Morocco, across main domains of Rif cordillera, in a joint effort from Spanish-Moroccan-USA scientists. Main goal of the RIFSIS survey was to achieve, for the first time, detailed crustal velocity-depth models on the southern flank of the Gibraltar Arc System. This asymmetric, arcuated system surrounding the Alboran Sea and composed by the Betic ranges on the N and the Rif cordillera on the S has undergone a complex tectonic evolution since Miocene times. Different types of evolutionary models have been proposed in the last decades, poorly constrained by the available geophysical results, specially on the southern flank, where crustal depths around 30 km have been proposed from inversion modeling of potential field datasets, in contrast with greater values up to 40 km depths and significant lateral variations from RF analysis. In the RIFSIS survey, almost 1000 Texans stations were deployed along the two profiles and 3 shots of 1 T were detonated along each one. The NS transect was extended northwards in Spain by a 75 km long segment in the Betics, and southwards it connects with an analogous profile recorded in 2010 across the Atlas Mountains (SIMA project), hence providing a 700 km long continuous seismic transect sampling the different tectonic domains. The high density of recording stations allows building up of vertical seismic sections focused on the Moho PmP reflections that reveal important variations along this transect. An extensive analysis based on travel time forward modeling has also been performed and main results are presented here. The interpreted crustal structure differentiates two sedimentary layers on top of the basement, inferred from the observed first arrivals at short offsets, followed by upper, mid and lower crustal levels constrained by reflected phases visible in the record sections. The bottom of the crust is well defined from PmP phases

  15. Wetting and evaporation studies on molecularly modified surfaces

    OpenAIRE

    Soolaman, Dinah Michele

    2007-01-01

    Wetting and evaporation of liquid microdroplets on solid surfaces are ubiquitous in nature. Two of the many important factors that influence how a droplet wets and “escapes”, are the chemical composition and roughness of the solid surface. In order to gain a better understanding of these processes as a whole, a systematic study on the factors that influence wetting/evaporation behaviour, including the liquid’s composition, the liquid-solid interface, and the substrate morphology has been carr...

  16. A review of ethanol wet-bonding: Principles and techniques.

    Science.gov (United States)

    Ayar, Muhammet Kerim

    2016-01-01

    Conventional water wet-bonding technique has been advocated by many scientists, but the excess water will induce suboptimal polymerization of dental adhesives, phase separation, and nanoleakage, which will influence the longevity of resin-dentin interfaces. Recent studies have put forward a new concept, ethanol wet-bonding. This technique can increase in dentin bond durability. This review focuses on the principles of ethanol wet-bonding, its surface treatment methods.

  17. A review of ethanol wet-bonding: Principles and techniques

    OpenAIRE

    Ayar, Muhammet Kerim

    2016-01-01

    Conventional water wet-bonding technique has been advocated by many scientists, but the excess water will induce suboptimal polymerization of dental adhesives, phase separation, and nanoleakage, which will influence the longevity of resin-dentin interfaces. Recent studies have put forward a new concept, ethanol wet-bonding. This technique can increase in dentin bond durability. This review focuses on the principles of ethanol wet-bonding, its surface treatment methods.

  18. Wet-Bulb-Globe Temperature Data Report

    Science.gov (United States)

    2015-03-01

    ARL‐SR‐0317 ● MAR 2015          US Army Research Laboratory      Wet‐Bulb– Globe  Temperature Data Report    by David P Sauter...originator.         ARL‐SR‐0317 ● MAR 2015      US Army Research Laboratory      Wet‐Bulb– Globe  Temperature Data Report    by David P Sauter...March 2015 2. REPORT TYPE  Special Report 3. DATES COVERED (From ‐ To)  11 Aug 2014–23 Aug 2014 4. TITLE AND SUBTITLE  Wet-Bulb– Globe Temperature

  19. Influence of surface charge on wetting kinetics.

    Science.gov (United States)

    Puah, Lee San; Sedev, Rossen; Fornasiero, Daniel; Ralston, John; Blake, Terry

    2010-11-16

    The wettability of a titania surface, partially covered with octadecyltrihydrosilane, has been investigated as a function of solution pH. The results show that surface charge affects both static wettability and wetting kinetics. The static contact angle decreases above and below the point of zero charge of the titania surface in a Lippman-like manner as the pH is altered. The dependence of dynamic contact angle on velocity is also affected by pH. The molecular-kinetic theory (MKT) is used to interpret the dynamic contact angle data. The frequency of molecular displacement κ(0) strongly varies with surface charge, whereas the mean molecular displacement length λ is essentially unaffected. There is an exponential dependence of contact-line friction upon work of adhesion, which is varied simply by altering the pH.

  20. BERYLLIUM MEASUREMENT IN COMMERCIALLY AVAILABLE WET WIPES

    Energy Technology Data Exchange (ETDEWEB)

    Youmans-Mcdonald, L.

    2011-02-18

    Analysis for beryllium by fluorescence is now an established method which is used in many government-run laboratories and commercial facilities. This study investigates the use of this technique using commercially available wet wipes. The fluorescence method is widely documented and has been approved as a standard test method by ASTM International and the National Institute for Occupational Safety and Health (NIOSH). The procedure involves dissolution of samples in aqueous ammonium bifluoride solution and then adding a small aliquot to a basic hydroxybenzoquinoline sulfonate fluorescent dye (Berylliant{trademark} Inc. Detection Solution Part No. CH-2) , and measuring the fluorescence. This method is specific to beryllium. This work explores the use of three different commercial wipes spiked with beryllium, as beryllium acetate or as beryllium oxide and subsequent analysis by optical fluorescence. The effect of possible interfering metals such as Fe, Ti and Pu in the wipe medium is also examined.

  1. Coefficient of Restitution of Wet Tennis Balls

    Directory of Open Access Journals (Sweden)

    Eugene Jang

    2014-12-01

    Full Text Available The coefficient of restitution of a damp tennis ball is of interest to tennis players. Using a spray bottle, water was added to a tennis ball and the mass of water on the wet ball was determined. The ball was then dropped from a fixed height of 0.86 m. The motion was recorded with a video camera and the bounce height was measured. Using the bounce height and the original height, the coefficient of restitution for that mass of added water was determined. The research found the mass of water added to the tennis ball to have a negatively linear relationship with the coefficient of restitution of the tennis ball.

  2. Coefficient of Restitution of Wet Tennis Balls

    Directory of Open Access Journals (Sweden)

    Eugene Jang

    2014-01-01

    Full Text Available The coefficient of restitution of a damp tennis ball is of interest to tennis players. Using a spray bottle, water was added to a tennis ball and the mass of water on the wet ball was determined. The ball was then dropped from a fixed height of 0.86 m. The motion was recorded with a video camera and the bounce height was measured. Using the bounce height and the original height, the coefficient of restitution for that mass of added water was determined. The research found the mass of water added to the tennis ball to have a negatively linear relationship with the coefficient of restitution of the tennis ball.

  3. Ensuring message embedding in wet paper steganography

    CERN Document Server

    Augot, Daniel; Fontaine, Caroline

    2011-01-01

    Syndrome coding has been proposed by Crandall in 1998 as a method to stealthily embed a message in a cover-medium through the use of bounded decoding. In 2005, Fridrich et al. introduced wet paper codes to improve the undetectability of the embedding by nabling the sender to lock some components of the cover-data, according to the nature of the cover-medium and the message. Unfortunately, almost all existing methods solving the bounded decoding syndrome problem with or without locked components have a non-zero probability to fail. In this paper, we introduce a randomized syndrome coding, which guarantees the embedding success with probability one. We analyze the parameters of this new scheme in the case of perfect codes.

  4. The geometry and wetting of capillary folding

    CERN Document Server

    Péraud, Jean-Philippe

    2014-01-01

    Capillary forces are involved in a variety of natural phenomena, ranging from droplet breakup to the physics of clouds. The forces from surface tension can also be exploited in industrial application provided the length scales involved are small enough. Recent experimental investigations showed how to take advantage of capillarity to fold planar structures into three-dimensional configurations by selectively melting polymeric hinges joining otherwise rigid shapes. In this paper we use theoretical calculations to quantify the role of geometry and fluid wetting on the final folded state. Considering folding in two and three dimensions, studying both hydrophilic and hydrophobic situations with possible contact angle hysteresis, and addressing the shapes to be folded to be successively infinite, finite, curved, kinked, elastic, we are able to derive an overview of the geometrical parameter space available for capillary folding.

  5. THERMAL TRANSFERS IN WET HYPERBARIC ENVIRONMENT

    Directory of Open Access Journals (Sweden)

    Tamara STANCIU

    2014-05-01

    Full Text Available The heat losses of human body are greater in underwater environment than in dry, normal atmosphere, due to the great heat capacity of water. Body temperature of divers in immersion was studied taking into account the pressure the divers are subjected to. The theoretic equation that describes the total heat transfer- at both levels: skin and respiratory system- was established, considering conduction, convection and respiratory gas heating and humidification. The body temperature of the divers was measured in a series of dives at different depths of immersion, conducted in the wet simulator of the Diving Center, in Constanta. The experimental results were in good accordance with the temperature predicted by the mathematical model.

  6. Textile UWB Antenna Bending and Wet Performances

    Directory of Open Access Journals (Sweden)

    Mai A. R. Osman

    2012-01-01

    Full Text Available The vision and ideas of wearable computing systems describe future electronic systems as an integral part of our everyday clothing that provides the wearer with such intelligent personal assistants. Recently, there has been growing interest in the antenna community to merge between wearable systems technology, ultrawideband (UWB technology and textile technology. This work aimed to make closer steps towards real wearability by investigating the possibilities of designing wearable UWB antenna where textile materials are used for the substrate as well as the conducting parts of the designed antenna. Two types of conducting materials have been used for conducting parts, while a nonconducting fabric has been used as antenna substrate material. A set of comparative results of the proposed design were presented and discussed. Moreover, effects on the return loss by means of measurements for each fabricated antenna prototype under bent and fully wet conditions were discussed in more details.

  7. Flow studies in a wet steam turbine

    Science.gov (United States)

    Evans, D. H.; Pouchot, W. D.

    1974-01-01

    The design and test results of a four stage wet vapor turbine operating with slightly superheated inlet steam and expanding to 10% exit moisture are presented. High speed movies at 3000 frames per second of liquid movement on the pressure side and along the trailing edge of the last stator blade are discussed along with back lighted photographs of moisture drops as they were torn from the stator blade trailing edge. Movies at lower framing rates were also taken of the exit of the last rotating blade and the casing moisture removal slot located in line with the rotor blade shroud. Also moisture removal data are presented of casing slot removal at the exit of the third and fourth rotor blades and for slots located in the trailing edge of the last stator blade. Finally, the degradation of turbine thermodynamic performance due to condensation formation and movement is discussed.

  8. Wetting dynamics of a collapsing fluid hole

    Science.gov (United States)

    Bostwick, Joshua; Dijksman, Joshua; Shearer, Michael

    2016-11-01

    An axisymmetric fluid cavity at the bottom of a rotating bucket bound by vertical sidewalls is studied, as it is filled in by the wetting fluid. Lubrication theory is applied to reduce the governing equations to a single evolution equation for the film thickness. In the quasi-static regime the contact-line motion is governed by a constitutive law relating the effective contact angle to the contact-line speed. The dependence of the collapse time on the initial hole size is calculated. For small holes, surface tension dominates the dynamics, leading to a universal power law that compares favorably to experiments in the literature. Further verification of the model is obtained through comparison of volume dependence with experimental results.

  9. Wetting dynamics of a collapsing fluid hole

    Science.gov (United States)

    Bostwick, J. B.; Dijksman, J. A.; Shearer, M.

    2017-01-01

    The collapse dynamics of an axisymmetric fluid cavity that wets the bottom of a rotating bucket bound by vertical sidewalls are studied. Lubrication theory is applied to the governing field equations for the thin film to yield an evolution equation that captures the effect of capillary, gravitational, and centrifugal forces on this converging flow. The focus is on the quasistatic spreading regime, whereby contact-line motion is governed by a constitutive law relating the contact-angle to the contact-line speed. Surface tension forces dominate the collapse dynamics for small holes with the collapse time appearing as a power law whose exponent compares favorably to experiments in the literature. Gravity accelerates the collapse process. Volume dependence is predicted and compared with experiment. Centrifugal forces slow the collapse process and lead to complex dynamics characterized by stalled spreading behavior that separates the large and small hole asymptotic regimes.

  10. Kinetics of wet sodium vapor complex plasma

    Science.gov (United States)

    Mishra, S. K.; Sodha, M. S.

    2014-04-01

    In this paper, we have investigated the kinetics of wet (partially condensed) Sodium vapor, which comprises of electrons, ions, neutral atoms, and Sodium droplets (i) in thermal equilibrium and (ii) when irradiated by light. The formulation includes the balance of charge over the droplets, number balance of the plasma constituents, and energy balance of the electrons. In order to evaluate the droplet charge, a phenomenon for de-charging of the droplets, viz., evaporation of positive Sodium ions from the surface has been considered in addition to electron emission and electron/ion accretion. The analysis has been utilized to evaluate the steady state parameters of such complex plasmas (i) in thermal equilibrium and (ii) when irradiated; the results have been graphically illustrated. As a significant outcome irradiated, Sodium droplets are seen to acquire large positive potential, with consequent enhancement in the electron density.

  11. Wick wetting for water condensation systems

    Energy Technology Data Exchange (ETDEWEB)

    Hering, Susanne Vera; Spielman, Steven Russel; Lewis, Gregory Stephen; Kreisberg, Nathan Michael

    2017-04-04

    A system and method for particle enlargement with continuously wetted wicks includes a container into which a flow of particle-laden air is introduced in a laminar manner through an inlet and to an outlet. The container has a first section, a second section and a third section though which the particle-laden air flows between the inlet and the outlet. The temperature of the second section is warmer than that of the first section at the inlet and the third section at the outlet. In one embodiment, a continuous wick spanning an interior wall of the first second, second section and third section, said wick being capable of internally transporting liquid water along its length is provided.

  12. Modeling of AC arc inside wet snow

    Energy Technology Data Exchange (ETDEWEB)

    Hemmatjou, H.

    2006-07-01

    Overhead transmission lines cover long distances over a broad range of topographic relief, climates, and environments. As such, the high voltage equipment is subject to pollution, wet snow and atmospheric icing. Each of these factors have been the source of power outages recorded on power transmission lines. Electric arcs can develop on outdoor insulators until they cause a total flashover. This study involved the modeling of flashover in snow-covered insulators to better understand how electric discharges initiate inside snow and how they develop into flashover. The main objective of this thesis was to develop a mathematical model to predict the flashover voltage of snow-covered insulator surfaces and to ultimately design adequate insulators for cold regions. The results obtained through mathematical modeling were in good agreement with those obtained in experiments.

  13. Microbial nitrogen dynamics in organic and mineral soil horizons along a latitudinal transect in western Siberia

    Science.gov (United States)

    Wild, Birgit; Schnecker, Jörg; Knoltsch, Anna; Takriti, Mounir; Mooshammer, Maria; Gentsch, Norman; Mikutta, Robert; Alves, Ricardo J. Eloy; Gittel, Antje; Lashchinskiy, Nikolay; Richter, Andreas

    2015-05-01

    Soil N availability is constrained by the breakdown of N-containing polymers such as proteins to oligopeptides and amino acids that can be taken up by plants and microorganisms. Excess N is released from microbial cells as ammonium (N mineralization), which in turn can serve as substrate for nitrification. According to stoichiometric theory, N mineralization and nitrification are expected to increase in relation to protein depolymerization with decreasing N limitation, and thus from higher to lower latitudes and from topsoils to subsoils. To test these hypotheses, we compared gross rates of protein depolymerization, N mineralization and nitrification (determined using 15N pool dilution assays) in organic topsoil, mineral topsoil, and mineral subsoil of seven ecosystems along a latitudinal transect in western Siberia, from tundra (67°N) to steppe (54°N). The investigated ecosystems differed strongly in N transformation rates, with highest protein depolymerization and N mineralization rates in middle and southern taiga. All N transformation rates decreased with soil depth following the decrease in organic matter content. Related to protein depolymerization, N mineralization and nitrification were significantly higher in mineral than in organic horizons, supporting a decrease in microbial N limitation with depth. In contrast, we did not find indications for a decrease in microbial N limitation from arctic to temperate ecosystems along the transect. Our findings thus challenge the perception of ubiquitous N limitation at high latitudes, but suggest a transition from N to C limitation of microorganisms with soil depth, even in high-latitude systems such as tundra and boreal forest.

  14. Line transect estimates of Irrawaddy dolphin abundance along the eastern Gulf Coast of Thailand.

    Directory of Open Access Journals (Sweden)

    Ellen eHines

    2015-09-01

    Full Text Available Effective conservation of coastal marine mammals is largely dependent on reliable knowledge of their abundance, as well as the ecological and human factors driving their distribution. In developing countries, lack of resources and capacity frequently impedes research needed to estimate abundance and to determine the ecological requirements of coastal marine mammals and the impact of threats related to coastal development and fisheries. Over the course of five years, we developed practical research methods and trained local scientists in Thailand to use accepted line transect distance sampling methods for abundance assessment. The study focused on a little-known coastal and freshwater species found throughout Southeast Asia, namely the Irrawaddy dolphin, which has been sighted regularly along the coast of the eastern Gulf of Thailand. During five years of line transect boat surveys in Trat Province, the eastern-most province in Thailand, we found an average of 423 dolphins distributed within 12km of the coast. Compared to other abundance estimates of coastal Irrawaddy dolphins in Southeast Asia, this is a relatively large number. This population could extend into the northern coast of Cambodia, where surveys are currently being planned. The Thai government has begun talks with Cambodia about a transboundary marine protected area that would include areas in both countries where coastal Irrawaddy dolphins are found. Other analyses include photo-identification, modeling environmental factors that determine presence, determination of fresh vs. salt water foraging using stable isotopes, and an assessment of threats. Collaboration between scientists in Thailand, Cambodia and Vietnam is further needed to determine dolphin movement and habitat use across borders.

  15. Neurogenesis and growth factors expression after complete spinal cord transection in Pleurodeles waltlii.

    Science.gov (United States)

    Zaky, Amira Z; Moftah, Marie Z

    2014-01-01

    Following spinal lesion, connections between the supra-spinal centers and spinal neuronal networks can be disturbed, which causes the deterioration or even the complete absence of sublesional locomotor activity. In mammals, possibilities of locomotion restoration are much reduced since descending tracts either have very poor regenerative ability or do not regenerate at all. However, in lower vertebrates, there is spontaneous locomotion recuperation after complete spinal cord transection at the mid-trunk level. This phenomenon depends on a translesional descending axon re-growth originating from the brainstem. On the other hand, cellular and molecular mechanisms underlying spinal cord regeneration and in parallel, locomotion restoration of the animal, are not well known. Fibroblast growth factor 2 (FGF-2) plays an important role in different processes such as neural induction, neuronal progenitor proliferation and their differentiation. Studies had shown an over expression of this growth factor after tail amputation. Nestin, a protein specific for intermediate filaments, is considered an early marker for neuronal precursors. It has been recently shown that its expression increases after tail transection in urodeles. Using this marker and western blots, our results show that the number of FGF-2 and FGFR2 mRNAs increases and is correlated with an increase in neurogenesis especially in the central canal lining cells immediately after lesion. This study also confirms that spinal cord re-growth through the lesion site initially follows a rostrocaudal direction. In addition to its role known in neuronal differentiation, FGF-2 could be implicated in the differentiation of ependymal cells into neuronal progenitors.

  16. Neurogenesis and growth factors expression after complete spinal cord transection in Pleurodeles waltlii

    Directory of Open Access Journals (Sweden)

    Amira Z Zaky

    2015-01-01

    Full Text Available Following spinal lesion, connections between the supra-spinal centers and spinal neuronal networks can be disturbed, which causes the deterioration or even the complete absence of sublesional locomotor activity. In Mammals, possibilities of locomotion restoration are much reduced since descending tracts either have very poor regenerative ability or do not regenerate at all. However, in lower Vertebrates, there is spontaneous locomotion recuperation after complete spinal cord transection at the mid-trunk level. This phenomenon depends on a translesional descending axon re-growth originating from the brainstem. On the other hand, cellular and molecular mechanisms underlying spinal cord regeneration and in parallel, locomotion restoration of the animal, are not well known. FGF-2 plays an important role in different processes such as neural induction, neuronal progenitor proliferation and their differentiation. Studies had shown an over expression of this growth factor after tail amputation. Nestin, a protein specific for intermediate filaments, is considered as an early marker for neuronal precursors. It has been recently shown that its expression increases after tail transection in Urodeles. Using this marker and western blots, our results show that the increase in the number of FGF-2 and FGFR2 mRNAs is correlated with an increase in neurogenesis especially in the central canal lining cells immediately after lesion. This study also confirms that spinal cord re-growth through the lesion site initially follows a rostrocaudal direction. In addition to its role known in neuronal differentiation, FGF-2 could be implicated in the differentiation of ependymal cells into neuronal progenitors.

  17. Nerve transection repair using laser-activated chitosan in a rat model.

    Science.gov (United States)

    Bhatt, Neel K; Khan, Taleef R; Mejias, Christopher; Paniello, Randal C

    2017-08-01

    Cranial nerve transection during head and neck surgery is conventionally repaired with microsuture. Previous studies have demonstrated recovery with laser nerve welding (LNW), a novel alternative to microsuture. LNW has been reported to have poorer tensile strength, however. Laser-activated chitosan, an adhesive biopolymer, may promote nerve recovery while enhancing the tensile strength of the repair. Using a rat posterior tibial nerve injury model, we compared four different methods of nerve repair in this pilot study. Animal study. Animals underwent unilateral posterior tibial nerve transection. The injury was repaired by potassium titanyl phosphate (KTP) laser alone (n = 20), KTP + chitosan (n = 12), microsuture + chitosan (n = 12), and chitosan alone (n = 14). Weekly walking tracks were conducted to measure functional recovery (FR). Tensile strength (TS) was measured at 6 weeks. At 6 weeks, KTP laser alone had the best recovery (FR = 93.4% ± 8.3%). Microsuture + chitosan, KTP + chitosan, and chitosan alone all showed good FR (87.4% ± 13.5%, 84.6% ± 13.0%, and 84.1% ± 10.0%, respectively). One-way analysis of variance was performed (F(3,56) = 2.6, P = .061). A TS threshold of 3.8 N was selected as a control mean recovery. Three groups-KTP alone, KTP + chitosan, and microsuture + chitosan-were found to meet threshold 60% (95% confidence interval [CI]: 23.1%-88.3%), 75% (95% CI: 46.8%-91.1%), and 100% (95% CI: 75.8%-100.0%), respectively. In the posterior tibial nerve model, all repair methods promoted nerve recovery. Laser-activated chitosan as a biopolymer anchor provided good TS and appears to be a novel alternative to microsuture. This repair method may have surgical utility following cranial nerve injury during head and neck surgery. NA Laryngoscope, 127:E253-E257, 2017. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

  18. Splenic autotransplantation and oesophageal transection anastomosis in patients with portal hypertension(26 years clinical observation)

    Institute of Scientific and Technical Information of China (English)

    CHEN Jisheng; HUO Jinshan; ZHANG Hongwei; SHANG Changzhen; CHEN Rufu; ZHANG Jie; Obetien Mapudengo; CHEN Yajin; ZHANG Lei

    2007-01-01

    The surgical treatment methods for cirrhosis patients complicated with portal hypertension are complicated.In this study,we evaluated the effectiveness of a new treatment strategy:splenic auto-transplantation and oesophageal transection anastomosis on 274 patients from three aspects:clinical observation,splenic immunology and portal dynamics.From 1979 to 2005,274 cirrhosis patients with portal hypertension who underwent the new treatment strategy were followed up to observe different clinical indexes,which were then compared with those of the traditional surgery treatment.From 1999 to 2002,a randomized control trial (RCT) was performed on 40 patients to compare their immune function after operation.From 1994 to 2004,another RCT.was carried out on 28 patients to compare the portal dynamics through three-dimensional dynamic contrast enhanced MR angiography (3D DEC MR.A) investigation after operation.Among 274 patients (mean age 41.8 years),the emergency operative mortality (4.4%),selective operative mortality (2.2%),complication rate (17.9%),morbidity of hepatic encephalopathy ( < 1%),bleeding rate of portal hypertension gastritis (PHG) (9.1%),and morbidity of hepatic carcinoma (8%) were similar to those under traditional operation;the spleen immunology function (Tuftsin,IgM)decreased among the groups 2 months after operation.Through 3D DCE MRA,the cross section area,the velocity and volume of blood flow of main portal vein decrease significantly after operation in both groups,the auto transplantation group was significantly lower in velocity and volume of blood flow than in the control group.Splenic auto transplantation and esophageal transection anastomosis are a safe,effective,and reasonable treatment strategy for portal hypertension with varicial bleeding.It can not only correct hypersplenism but also completely stanch blood,and auto transplanted spleen in the retroperitoneal space can preserve immune function and establish abroad collateral circulation.

  19. Global coverage of cetacean line-transect surveys: status quo, data gaps and future challenges.

    Directory of Open Access Journals (Sweden)

    Kristin Kaschner

    Full Text Available Knowledge of abundance, trends and distribution of cetacean populations is needed to inform marine conservation efforts, ecosystem models and spatial planning. We compiled a geo-spatial database of published data on cetacean abundance from dedicated visual line-transect surveys and encoded >1100 abundance estimates for 47 species from 430 surveys conducted worldwide from 1975-2005. Our subsequent analyses revealed large spatial, temporal and taxonomic variability and gaps in survey coverage. With the exception of Antarctic waters, survey coverage was biased toward the northern hemisphere, especially US and northern European waters. Overall, <25% of the world's ocean surface was surveyed and only 6% had been covered frequently enough (≥ 5 times to allow trend estimation. Almost half the global survey effort, defined as total area (km(2 covered by all survey study areas across time, was concentrated in the Eastern Tropical Pacific (ETP. Neither the number of surveys conducted nor the survey effort had increased in recent years. Across species, an average of 10% of a species' predicted range had been covered by at least one survey, but there was considerable variation among species. With the exception of three delphinid species, <1% of all species' ranges had been covered frequently enough for trend analysis. Sperm whales emerged from our analyses as a relatively data-rich species. This is a notoriously difficult species to survey visually, and we use this as an example to illustrate the challenges of using available data from line-transect surveys for the detection of trends or for spatial planning. We propose field and analytical methods to fill in data gaps to improve cetacean conservation efforts.

  20. The vegetation coverage dynamic coupling with climatic factors in Northeast China Transect.

    Science.gov (United States)

    Nie, Qin; Xu, Jianhua; Ji, Minhe; Cao, Lei; Yang, Yang; Hong, Yulian

    2012-09-01

    Based on SPOT-VGT images and meteorological data, this paper applied an integrated method to investigate the vegetation dynamic and its response to climate factors during 1998-2008 in Northeast China Transect, one of 15 ecological transects listed in the International Geosphere-Biosphere Programme. The main findings are as follows: (1) The NDVI time series presented nonlinear patterns that vary with timescales. The series fluctuated greatly at the smallest timescale (20 days), showing no salient trend, whereas a trend manifested itself more and more with the increase of time scale and finally stabilized at the 320-day scale. Little difference was found between vegetation types about the NDVI periodicity, as they occurred on either a 280-day or a 290-day cycle. (2) NDVI exhibited a significant correlation with temperature, precipitation, and sunshine hours. Overall, the correlation between NDVI and temperature was the highest, followed by precipitation, sunshine hours, and relative humidity. For different vegetation types, the correlations between NDVI and climate variables diversified, increasing from desert steppe to typical steppe, meadow steppe, and forest. (3) The periodicity of temperature and precipitation occurred in either a 280-day or 290-day cycle, which was approximately coincident with that of NDVI. This further supported the significant relationship between NDVI and these two climate factors. (4) At all the time scales under examination, NDVI and temperature and precipitation are significantly, positively correlated, especially at the 160-day scale, which can be regarded as the most suitable time scale for investigating the responses of vegetation dynamics to climate factors at most stations.

  1. Trans-Alaska Crustal Transect and continental evolution involving subduction underplating and synchronous foreland thrusting

    Science.gov (United States)

    Fuis, G.S.; Moore, T.E.; Plafker, G.; Brocher, T.M.; Fisher, M.A.; Mooney, W.D.; Nokleberg, W.J.; Page, R.A.; Beaudoin, B.C.; Christensen, N.I.; Levander, A.R.; Lutter, W.J.; Saltus, R.W.; Ruppert, N.A.

    2008-01-01

    We investigate the crustal structure and tectonic evolution of the North American continent in Alaska, where the continent has grown through magmatism, accretion, and tectonic underplating. In the 1980s and early 1990s, we conducted a geological and geophysical investigation, known as the Trans-Alaska Crustal Transect (TACT), along a 1350-km-long corridor from the Aleutian Trench to the Arctic coast. The most distinctive crustal structures and the deepest Moho along the transect are located near the Pacific and Arctic margins. Near the Pacific margin, we infer a stack of tectonically underplated oceanic layers interpreted as remnants of the extinct Kula (or Resurrection) plate. Continental Moho just north of this underplated stack is more than 55 km deep. Near the Arctic margin, the Brooks Range is underlain by large-scale duplex structures that overlie a tectonic wedge of North Slope crust and mantle. There, the Moho has been depressed to nearly 50 km depth. In contrast, the Moho of central Alaska is on average 32 km deep. In the Paleogene, tectonic underplating of Kula (or Resurrection) plate fragments overlapped in time with duplexing in the Brooks Range. Possible tectonic models linking these two regions include flat-slab subduction and an orogenic-float model. In the Neogene, the tectonics of the accreting Yakutat terrane have differed across a newly interpreted tear in the subducting Pacific oceanic lithosphere. East of the tear, Pacific oceanic lithosphere subducts steeply and alone beneath the Wrangell volcanoes, because the overlying Yakutat terrane has been left behind as underplated rocks beneath the rising St. Elias Range, in the coastal region. West of the tear, the Yakutat terrane and Pacific oceanic lithosphere subduct together at a gentle angle, and this thickened package inhibits volcanism. ?? 2008 The Geological Society of America.

  2. Mercury and Methylmercury Distributions Along a Longitudinal Transect of the North Atlantic Ocean

    Science.gov (United States)

    Krabbenhoft, D. P.; Maglio, M.; Ogorek, J.; Landing, W. M.; Morton, P. L.; Shelley, R.; Sunderland, E. M.

    2014-12-01

    From August 1 to September 23, 2013 the A16N Repeat Hydrography Cruise (US CLIVAR program) conducted a nearly longitudinal (~20-25°W) sampling transect of the Atlantic Ocean (63°N to 6°S) originating in Reykjavik, Iceland. Water column profiles were taken at 145 locations along this transect, and at 13 of these locations samples for total mercury (THg) and methylmercury (MeHg) were also collected. Although profile depths for this cruise reached nearly 6000 m, Hg and MeHg sampling was limited to 12 discrete samples ranging from the surface to about the 1000 m. All samples were collected while observing strict adherence to trace-metal-free protocols. Upon collection from the rosette, each whole-water sample was immediately acidified to 1% HCl, thus our analysis of THg and MeHg includes both particulate and filter-passing fractions. For MeHg, our results represent a composite of both monomethyl and dimethyl mercury species. All samples were analyzed at the USGS Mercury Research Lab. Our results show several clear and interesting trends. First, an examination of THg versus MeHg reveals a bimodal distribution. Samples with THg > 0.03 pM show a highly correlated and linear distribution (R2=0.72) and a high mean percentage of MeHg (49%). On the other hand, samples with THg levels observed in profiles collected between 9 and 14°N. This region of the North Atlantic Ocean is associated with an oxygen minimum and PCO2 maximum zone both driven by degradation of sinking algal-derived organic matter. Last, the overall results from the Atlantic Ocean show a clear MeHg enrichment compared to similar data collected in the Pacific and Southern Indian Oceans.

  3. Nitrogen fixation in sediments along a depth transect through the Peruvian oxygen minimum zone

    Science.gov (United States)

    Gier, J.; Sommer, S.; Löscher, C. R.; Dale, A. W.; Schmitz, R. A.; Treude, T.

    2015-09-01

    Benthic nitrogen (N2) fixation and sulfate reduction (SR) were investigated in the Peruvian oxygen minimum zone (OMZ). Sediment samples, retrieved by a multiple corer were taken at six stations (70-1025 m) along a depth transect at 12° S, covering anoxic and hypoxic bottom water conditions. Benthic N2 fixation was detected at all sites, with high rates measured in OMZ mid-waters between the 70 and 253 m and lowest N2 fixation rates below 253 m down to 1025 m water depth. SR rates were decreasing with increasing water depth, with highest rates at the shallow site. Benthic N2 fixation depth profiles largely overlapped with SR depth profiles, suggesting that both processes are coupled. The potential of N2 fixation by SR bacteria was verified by the molecular analysis of nifH genes. Detected nifH sequences clustered with SR bacteria that have been demonstrated to fix N2 in other benthic environments. Depth-integrated rates of N2 fixation and SR showed no direct correlation along the 12° S transect, suggesting that the benthic diazotrophs in the Peruvian OMZ are being controlled by additional various environmental factors. The organic matter availability and the presence of sulfide appear to be major drivers for benthic diazotrophy. It was further found that N2 fixation was not inhibited by high ammonium concentrations. N2 fixation rates in OMZ sediments were similar to rates measured in other organic-rich sediments. Overall, this work improves our knowledge on N sources in marine sediments and contributes to a better understanding of N cycling in OMZ sediments.

  4. Muscle differentiation after sciatic nerve transection and reinnervation in adult rats.

    Science.gov (United States)

    Ijkema-Paassen, J; Meek, M F; Gramsbergen, A

    2001-07-01

    Reinnervation after peripheral nerve transections generally leads to poor functional recovery. In order to study whether changes in muscles might be a contributing factor in this phenomenon we studied muscle morphology and fibre type distributions after sciatic nerve transection in the rat hind limb. Proximally, before the bifurcation in the tibial and common peroneal nerve, a 12 mm segment of the sciatic nerve was resected, reversed and re-implanted as an autologous nerve graft. After survival periods of 7, 15 and 21 weeks the lateral gastrocnemius, tibialis anterior and soleus muscles were dissected, stained with mATP-ase, and fibre type distributions were studied. In addition, numbers of muscle fibres were counted, and cross sectional areas were calculated. After 7 weeks, cross sectional areas were decreased in all muscles. In the gastrocnemius and tibialis anterior muscles the fibre number remained unaltered but the hypotrophy had been reversed at later ages. The number of muscle fibres in the soleus muscle remained decreased over the entire period of observation. The percentages of type II fibres in the gastrocnemius and tibialis anterior muscles were decreased at 7 and 15 weeks but these again approached normal values at 21 weeks. The type I fibres, however, remained arranged in groups. In the soleus muscle a large increase in the percentage of type II muscle fibres was observed and this remained until 21 weeks. We conclude that a non-selective reinnervation and later readjustments by regression of polyneural innervation may in part explain the changes in distributions of various fibre types.

  5. Toward a predictive theory of wetting dynamics.

    Science.gov (United States)

    Duvivier, Damien; Blake, Terence D; De Coninck, Joël

    2013-08-13

    The molecular kinetic theory (MKT) of dynamic wetting, first proposed nearly 50 years ago, has since been refined to account explicitly for the effects of viscosity and solid-liquid interactions. The MKT asserts that the systematic deviation of the dynamic contact angle from its equilibrium value quantitatively reflects local energy dissipation (friction) at the moving contact line as it traverses sites of solid-liquid interaction. Specifically, it predicts that the coefficient of contact-line friction ζ will be proportional to the viscosity of the liquid ηL and exponentially dependent upon the strength of solid-liquid interactions as measured by the equilibrium work of adhesion Wa(0). Here, we analyze a very large set of dynamic wetting data drawn from more than 20 publications and representative of a very wide range of systems, from molecular-dynamics-simulated Lenard-Jones liquids and substrates, through conventional liquids and solids, to molten glasses and liquid metals on refractory solids. The combined set spans 9 decades of viscosity and 11 decades of contact-line friction. Our analysis confirms the predicted dependence of ζ upon ηL and Wa(0), although the data are scattered. In particular, a plot of ln(ζ/ηL) versus Wa(0)/n (i.e., the work of adhesion per solid-liquid interaction site) is broadly linear, with 85% of the data falling within a triangular envelope defined by Wa(0) and 0.25Wa(0). Various reasons for this divergence are explored, and a semi-empirical approach is proposed to predict ζ. We suggest that the broad agreement between the MKT and such a wide range of data is strong evidence that the local microscopic contact angle is directly dependent upon the velocity of the contact line.

  6. Five-years of microenvironment data along an urban-rural transect; temperature and CO2 concentrations in urban area at levels expected globally with climate change.

    Energy Technology Data Exchange (ETDEWEB)

    George, Kate; Ziska, Lewis H; Bunce, James A; Quebedeaux, Bruno

    2007-11-01

    The heat island effect and the high use of fossil fuels in large city centers is well documented, but by how much fossil fuel consumption is elevating atmospheric CO2 concentrations and whether elevations in both atmospheric CO2 and air temperature are consistent from year to year are less well known. Our aim was to record atmospheric CO2 concentrations, air temperature and other environmental variables in an urban area and compare it to suburban and rural sites to see if urban sites are experiencing climates expected globally in the future with climate change. A transect was established from Baltimore city center (Urban site), to the outer suburbs of Baltimore (suburban site) and out to an organic farm (rural site). At each site a weather station was set-up to monitor environmental variables annually for five years. Atmospheric CO2 was significantly increased on average by 66 ppm from the rural to the urban site over the five years of the study. Air temperature was significantly higher at the urban site (14.8 oC) compared to the suburban (13.6 oC) and rural (12.7 oC) sites. Relative humidity was not different between sites but vapor pressure deficit (VPD) was significantly higher at the urban site compared to the suburban and rural sites. During wet years relative humidity was significantly increased and VPD significantly reduced. Increased nitrogen deposition at the rural site (2.1 % compared to 1.8 and 1.2 % at the suburban and urban sites) was small enough not to affect soil nitrogen content. Dense urban areas with large populations and high vehicular traffic have significantly different microclimates compared to outlying suburban and rural areas. The increases in atmospheric CO2 and air temperature are similar to changes predicted in the short term with global climate change, therefore providing an environment suitable for studying future effects of climate change on terrestrial ecosystems.

  7. Strongly anisotropic wetting on one-dimensional nanopatterned surfaces.

    Science.gov (United States)

    Xia, Deying; Brueck, S R J

    2008-09-01

    This communication reports strongly anisotropic wetting behavior on one-dimensional nanopatterned surfaces. Contact angles, degree of anisotropy, and droplet distortion are measured on micro- and nanopatterned surfaces fabricated with interference lithography. Both the degree of anisotropy and the droplet distortion are extremely high as compared with previous reports because of the well-defined nanostructural morphology. The surface is manipulated to tune with the wetting from hydrophobic to hydrophilic while retaining the structural wetting anisotropy with a simple silica nanoparticle overcoat. The wetting mechanisms are discussed. Potential applications in microfluidic devices and evaporation-induced pattern formation are demonstrated.

  8. Wet explosion og wheat straw and codigestion with swine manure

    DEFF Research Database (Denmark)

    Wang, Guangtao; Gavala, Hariklia N.; Skiadas, Ioannis V.

    2009-01-01

    with wheat straw in a continuous operated system was investigated, as a method to increase the efficiency of biogas plants that are based on anaerobic digestion of swine manure. Also, the pretreatment of wheat straw with the wet explosion method was studied and the efficiency of the wet explosion process...... was evaluated based on (a) the sugars release and (b) the methane potential of the pretreated wheat straw compared to that of the raw biomass. It was found that, although a high release of soluble sugars was observed after wet explosion, the methane obtained from the wet-exploded wheat straw was slightly lower...

  9. Letting Wet Spots be Wet: Restoring Natural Bioreactors in the Dissected Glacial Landscape

    Science.gov (United States)

    Schilling, Keith E.; McLellan, Eileen; Bettis, E. Arthur

    2013-12-01

    In this paper, we argue that there is tremendous potential for nitrate-N reductions to occur throughout the Corn Belt region of the USA if we simply let naturally occurring wet spots on the landscape be wet. Geologic and hydrologic data gathered in the Walnut Creek watershed located in south-central Iowa provides compelling evidence that substantial nutrient-processing capacity exists in this dissected glacial landscape. Self-similarity of stratigraphy, sedimentology and hydrology observed at all spatial scales in the watershed suggests that Holocene alluvial fill deposits provide a natural bioreactor for denitrification of upland groundwater nitrate-N; the occurrence of such deposits can be mapped to identify potential nitrogen sinks across the landscape. This approach to identifying potential nitrogen sinks is geology focused and extends potential locations for nutrient processing upstream into the headwater catchments of individual fields.

  10. Biodiesel production from wet microalgae feedstock using sequential wet extraction/transesterification and direct transesterification processes.

    Science.gov (United States)

    Chen, Ching-Lung; Huang, Chien-Chang; Ho, Kao-Chia; Hsiao, Ping-Xuan; Wu, Meng-Shan; Chang, Jo-Shu

    2015-10-01

    Although producing biodiesel from microalgae seems promising, there is still a lack of technology for the quick and cost-effective conversion of biodiesel from wet microalgae. This study was aimed to develop a novel microalgal biodiesel producing method, consisting of an open system of microwave disruption, partial dewatering (via combination of methanol treatment and low-speed centrifugation), oil extraction, and transesterification without the pre-removal of the co-solvent, using Chlamydomonas sp. JSC4 with 68.7 wt% water content as the feedstock. Direct transesterification with the disrupted wet microalgae was also conducted. The biomass content of the wet microalgae increased to 56.6 and 60.5 wt%, respectively, after microwave disruption and partial dewatering. About 96.2% oil recovery was achieved under the conditions of: extraction temperature, 45°C; hexane/methanol ratio, 3:1; extraction time, 80 min. Transesterification of the extracted oil reached 97.2% conversion within 15 min at 45°C and 6:1 solvent/methanol ratio with simultaneous Chlorophyll removal during the process. Nearly 100% biodiesel conversion was also obtained while conducting direct transesterification of the disrupted oil-bearing microalgal biomass. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Topographic, bioclimatic, and vegetation characteristics of three ecoregion classification systems in North America: comparisons along continent-wide transects.

    Science.gov (United States)

    Thompson, Robert S; Shafer, Sarah L; Anderson, Katherine H; Strickland, Laura E; Pelltier, Richard T; Bartlein, Patrick J; Kerwin, Michael W

    2004-01-01

    Ecoregion classification systems are increasingly used for policy and management decisions, particularly among conservation and natural resource managers. A number of ecoregion classification systems are currently available, with each system defining ecoregions using different classification methods and different types of data. As a result, each classification system describes a unique set of ecoregions. To help potential users choose the most appropriate ecoregion system for their particular application, we used three latitudinal transects across North America to compare the boundaries and environmental characteristics of three ecoregion classification systems [Küchler, World Wildlife Fund (WWF), and Bailey]. A variety of variables were used to evaluate the three systems, including woody plant species richness, normalized difference in vegetation index (NDVI), and bioclimatic variables (e.g., mean temperature of the coldest month) along each transect. Our results are dominated by geographic patterns in temperature, which are generally aligned north-south, and in moisture, which are generally aligned east-west. In the west, the dramatic changes in physiography, climate, and vegetation impose stronger controls on ecoregion boundaries than in the east. The Küchler system has the greatest number of ecoregions on all three transects, but does not necessarily have the highest degree of internal consistency within its ecoregions with regard to the bioclimatic and species richness data. In general, the WWF system appears to track climatic and floristic variables the best of the three systems, but not in all regions on all transects.

  12. FBSAB PREDATOR Reef Fish Belt Transect Surveys at Hawaii Island (Big Island), Main Hawaiian Islands, 2009 (NODC Accession 0073870)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Shore-based belt transects were conducted at 1 to ~5 m depths at a total two (2) sites: at 2 longshore sites on the leeward coast (South Kohala district) of the Big...

  13. Functional recovery after transection of the sciatic nerve at an early age : a pilot study in rats

    NARCIS (Netherlands)

    Meek, Marcel F.; IJkema-Paassen, Jos; Gramsbergen, Albert

    It is often clinically noted that peripheral nerve transections in infants and very young children seem to show better functional recovery after nerve repair compared with adult patients. There can be several reasons for this (e.g. outgrowing axons might have maintained their potential to locate

  14. Erythropoietin improves place learning in fimbria-fornix-transected rats and modifies the search pattern of normal rats

    DEFF Research Database (Denmark)

    Mogensen, Jesper; Miskowiak, Kamilla; Sørensen, Thomas Alrik

    2004-01-01

    The acquisition of a water-maze-based allocentric place learning task was studied in four groups of rats: two groups subjected to bilateral transections of the fimbria-fornix and two groups undergoing a sham control operation. At the moment of surgery all animals were given one systemic (intraper......The acquisition of a water-maze-based allocentric place learning task was studied in four groups of rats: two groups subjected to bilateral transections of the fimbria-fornix and two groups undergoing a sham control operation. At the moment of surgery all animals were given one systemic...... (intraperitoneal) injection of either human recombinant erythropoietin (EPO) (at a dosage of 5000 IU/kg body weight), given to one of the fimbria-fornix-transected groups and one of the sham-operated groups, or vehicle (saline), given to the two remaining groups. The 25-day task acquisition period (one session...... administration of EPO significantly improves the posttraumatic functional recovery of the presently studied place learning task after transections of the fimbria-fornix. Additionally, administration of EPO influences the strategy, although not quality, of task solution in normal (sham-operated) rats....

  15. Functional recovery after transection of the sciatic nerve at an early age : a pilot study in rats

    NARCIS (Netherlands)

    Meek, Marcel F.; IJkema-Paassen, Jos; Gramsbergen, Albert

    2007-01-01

    It is often clinically noted that peripheral nerve transections in infants and very young children seem to show better functional recovery after nerve repair compared with adult patients. There can be several reasons for this (e.g. outgrowing axons might have maintained their potential to locate the

  16. Accurate mobile remote sensing of XCO2 and XCH4 latitudinal transects from aboard a research vessel

    Directory of Open Access Journals (Sweden)

    F. Klappenbach

    2015-07-01

    observations of the GOSAT satellite and concentration fields modeled by the European Centre for Medium-Range Weather Forecasts (ECMWF within the project Monitoring of Atmospheric Composition and Climate – Interim Implementation (MACC-II demonstrate that the observational setup is well suited to provide validation opportunities above the ocean and along interhemispheric transects.

  17. Tracing variability in the iodine isotopes and species along surface water transect from the North Sea to the Canary Islands

    DEFF Research Database (Denmark)

    He, Peng; Aldahan, Ala; Hou, Xiaolin

    2016-01-01

    A complete transect of surface water samples from the North Sea to the Canary Islands was collected during a continuous period in 2010. The samples were analyzed for total 129I and 127I isotopes and their iodide and iodate species. The results indicate a large variability in the total 129I and it...

  18. Continental-scale patterns in soil geochemistry and mineralogy: results from two transects across the United States and Canada

    Science.gov (United States)

    Woodruff, L.G.; Cannon, W.F.; Eberl, D.D.; Smith, D.B.; Kilburn, J.E.; Horton, J.D.; Garrett, R.G.; Klassen, R.A.

    2009-01-01

    In 2004, the US Geological Survey (USGS) and the Geological Survey of Canada (GSC) initiated a pilot study that involved collection of more than 1500 soil samples from 221 sites along two continental transects across Canada and the United States. The pilot study was designed to test and refine protocols for a soil geochemical survey of North America. The two transects crossed a wide array of soil parent materials, soil ages, climatic conditions, landforms, land covers and land uses. Sample sites were selected randomly at approximately 40-km intervals from a population defined as all soils of the continent. At each site, soils representing 0 to 5 cm depth, and the O, A, and C horizons, if present, were collected and analyzed for their near-total content of over 40 major and trace elements. Soils from 0–5 cm depth were also collected for analysis of organic compounds. Results from the transects confirm that soil samples collected at a 40-km spacing reveal coherent, continental- to subcontinental-scale geochemical and mineralogical patterns that can be correlated to aspects of underlying soil parent material, soil age and climate influence. The geochemical data also demonstrate that at the continental-scale the dominance of any of these major factors that control soil geochemistry can change across the landscape. Along both transects, soil mineralogy and geochemistry change abruptly with changes in soil parent materials. However, the chemical influence of a soil’s parent material can be obscured by changing climatic conditions. For the transects, increasing precipitation from west to east and increasing temperature from north to south affect both soil mineralogy and geochemistry because of climate effects on soil weathering and leaching, and plant productivity. Regional anomalous metal concentrations can be linked to natural variations in soil parent materials, such as high Ni and Cr in soils developed on ultramafic rocks in California or high P in soils formed on

  19. GPD+ wet tropospheric correctionsfor eight altimetric missions

    Science.gov (United States)

    Fernandes, Joana; Benveniste, Jérôme; Lázaro, Clara

    2016-07-01

    Due to its large space-temporal variability, the delay induced by the water vapour and liquid water content of the atmosphere in the altimeter signal or wet tropospheric delay (WTD) is still one of the largest sources of uncertainty in satellite altimetry. In the scope of the Sea Level Climate Change Initiative (SL-cci) project, the University of Porto (UPorto) has been developing methods to improve the wet tropospheric correction (WTC), which corrects for the effect of the WPD in the altimetric measurements. Developed as a coastal algorithm to remove land effects in the microwave radiometers (MWR) on board altimeter missions, the GNSS-derived Path Delay (GPD) methodology evolved over time, currently correcting for invalid observations due to land, ice and rain contamination, band instrument malfunction in open ocean, coastal and polar regions. The most recent version of the algorithm, GPD Plus (GPD+) computes wet path delays based on: i) WTC from the on-board MWR measurements, whenever they exist and are valid; ii) new WTC values estimated through space-time objective analysis of all available data sources, whenever the previous are considered invalid. In the estimation of the new WTC values, the following data sets are used: valid measurements from the on-board MWR, water vapour products derived from a set of 17 scanning imaging radiometers (SI-MWR) on board various remote sensing satellites and tropospheric delays derived from Global Navigation Satellite Systems (GNSS) coastal and island stations. In the estimation process, WTC derived from an atmospheric model such as the European Centre for Medium-range Weather Forecasts (ECMWF) ReAnalysis (ERA) Interim or the operational (Op) model are used as first guess, which is the adopted value in the absence of measurements. The corrections are provided for the most recent products of all missions used to generate the SL Essential Climate Variable (ECV): TOPEX/Poseidon- T/P, Jason-1, Jason-2, ERS-1, ERS-2, CryoSat-2

  20. Wetting theory for small droplets on textured solid surfaces

    Science.gov (United States)

    Kim, Donggyu; Pugno, Nicola M.; Ryu, Seunghwa

    2016-11-01

    Conventional wetting theories on rough surfaces with Wenzel, Cassie-Baxter, and Penetrate modes suggest the possibility of tuning the contact angle by adjusting the surface texture. Despite decades of intensive study, there are still many experimental results that are not well understood because conventional wetting theory, which assumes an infinite droplet size, has been used to explain measurements of finite-sized droplets. Here, we suggest a wetting theory applicable to a wide range of droplet size for the three wetting modes by analyzing the free energy landscape with many local minima originated from the finite size. We find that the conventional theory predicts the contact angle at the global minimum if the droplet size is about 40 times or larger than the characteristic scale of the surface roughness, regardless of wetting modes. Furthermore, we obtain the energy barrier of pinning which can induce the contact angle hysteresis as a function of geometric factors. We validate our theory against experimental results on an anisotropic rough surface. In addition, we discuss the wetting on non-uniformly rough surfaces. Our findings clarify the extent to which the conventional wetting theory is valid and expand the physical understanding of wetting phenomena of small liquid drops on rough surfaces.

  1. Fingerlike wetting patterns in two water-repellent loam soils

    NARCIS (Netherlands)

    Dekker, L.W.; Ritsema, C.J.

    1995-01-01

    In soils with fingered flow, surface-applied solutes can reach the groundwater more rapidly than in the case of homogeneous wetting. This study was undertaken to demonstrate the occurrence of finger-like wetting patterns in a silt loam soil and a silty clay loam soil, and to investigate the

  2. Wetting dynamics of a water nanodrop on graphene.

    Science.gov (United States)

    Andrews, Joseph Eugene; Sinha, Shayandev; Chung, Peter W; Das, Siddhartha

    2016-09-14

    Water-graphene wetting interactions are central to several applications such as desalination, water filtration, electricity generation, biochemical sensing, fabrication of fuel cells, and many more. While substantial attention has been devoted to probe the wetting statics of a water drop on graphene, unraveling the possible wetting translucency nature of graphene, very little research has been done on the dynamics of wetting of water drops on graphene-coated solids or free-standing graphene layers. In this paper, we employ molecular dynamics (MD) simulations to study the contact and the spreading of a water nanodrop, quantifying its wetting dynamics, on supported and free-standing graphene. We demonstrate that nanoscale water drops establish contact with graphene by forming patches on graphene, and this patch formation is hastened for graphene layer(s) supported on hydrophilic solids. More importantly, our results demonstrate that the nanodrop spreading dynamics, regardless of the number of graphene layers or the nature of the underlying solid, obey the half-power law, i.e., r∼t(1/2) (where r is the wetting contact radius and t is the spreading time) for the entire timespan of spreading except towards the very end of the spreading lifetime when the spreading stops. Such a spreading behavior is exactly analogous to the spreading dynamics of nanodroplets for standard solids - this is in sharp contrast to the wetting statics of graphene where the wetting translucency effect makes graphene different from other standard solids.

  3. Analysis on Wetting Deformation Properties of Silty Clay

    Directory of Open Access Journals (Sweden)

    Xinrong Liu

    2014-06-01

    Full Text Available Changes in water level that cause deformation and stability problems often occur in foundation pit engineering. Water damage is one of the main problems that will lead to disasters in foundation pit engineering. Research findings with regard to properties of wetting deformation due to water damage can be applied not only in foundation pit engineering, slope engineering, hydraulic engineering, and mining engineering but also in related issues in the field of theoretical research and practice. In this study, the characteristics of silty clay deformation after wetting are examined from the perspective of the effect of wetting on the side wall of foundation pit, and wetting experiments on silty clay of a selected area’s stratum located in Chongqing Municipality are conducted under different confining pressures and stress levels through a multi-function triaxial apparatus. Then, laws of silty clay wetting deformation are obtained, and the relationship between wetting stress level and wetting deformation amount is also figured out. The study reveals that the maximum values of wetting deformation under different confining pressures have appear at a particular stress level; therefore, the related measures should be taken to avoid this deformation in the process of construction.

  4. Hydrodynamics of a Multistage Wet Scrubber Incineration Conditions

    Science.gov (United States)

    Said, M. M.; Manyele, S. V.; Raphael, M. L.

    2012-01-01

    The objective of the study was to determine the hydrodynamics of the two stage counter-current cascade wet scrubbers used during incineration of medical waste. The dependence of the hydrodynamics on two main variables was studied: Inlet air flow rate and inlet liquid flow rate. This study introduces a new wet scrubber operating features, which are…

  5. Phase change materials and the perception of wetness

    NARCIS (Netherlands)

    Bergmann Tiest, W.M.; Kosters, N.D.; Kappers, A.M.L.; Daanen, H.A.M.

    2012-01-01

    Phase change materials (PCMs) are increasingly incorporated in textiles in order to serve as a thermal buffer when humans change from a hot to a cold environment and the reverse. Due to the absence of wetness sensors in the skin, cooling of the skin may be perceived as a sensation of wetness instead

  6. Contact angle and local wetting at contact line.

    Science.gov (United States)

    Li, Ri; Shan, Yanguang

    2012-11-06

    This theoretical study was motivated by recent experiments and theoretical work that had suggested the dependence of the static contact angle on the local wetting at the triple-phase contact line. We revisit this topic because the static contact angle as a local wetting parameter is still not widely understood and clearly known. To further clarify the relationship of the static contact angle with wetting, two approaches are applied to derive a general equation for the static contact angle of a droplet on a composite surface composed of heterogeneous components. A global approach based on the free surface energy of a thermodynamic system containing the droplet and solid surface shows the static contact angle as a function of local surface chemistry and local wetting state at the contact line. A local approach, in which only local forces acting on the contact line are considered, results in the same equation. The fact that the local approach agrees with the global approach further demonstrates the static contact angle as a local wetting parameter. Additionally, the study also suggests that the wetting described by the Wenzel and Cassie equations is also the local wetting of the contact line rather than the global wetting of the droplet.

  7. Enzymatic corn wet milling: engineering process and cost model

    Science.gov (United States)

    Enzymatic Corn Wet Milling (E-Milling) is a proposed alternative process to conventional wet milling for the recovery and purification of starch and coproducts using proteases to eliminate the need for sulfites and to decrease the steeping time. In 2005, the total starch production in USA by conven...

  8. Global variations in droughts and wet spells: 1900–1995

    National Research Council Canada - National Science Library

    Dai, Aiguo; Trenberth, Kevin E; Karl, Thomas R

    1998-01-01

    ...., over the Sahel, eastern Asia and southern Africa) or both the drought and wet areas (e.g., over the U.S. and Europe). Although the high percentages of the dry and wet areas in the recent decades are not unprecedented during this century...

  9. Curative resection of hepatocellular carcinoma using modified Glissonean pedicle transection versus the Pringle maneuver: a case control study.

    Science.gov (United States)

    Ji, Bai; Wang, Yingchao; Wang, Guangyi; Liu, Yahui

    2012-01-01

    The Glissonean pedicle transection method of liver resection has been found to shorten operative time and minimize intraoperative bleeding during liver segmentectomy. We have compared the feasibility, effectiveness, and safety of the Glissonean pedicle transection method with the Pringle maneuver in patients undergoing selective curative resection of large hepatocellualr carcinoma (HCC). Eligible patients with large (> 5 cm) nodular HCC (n = 50) were assigned to undergo curative hepatectomy using the Glissonean pedicle transection method (n = 25) or the Pringle maneuver (n = 25). Partial interruption of the infrahepatic inferior vena cava was incorporated to further reduce bleeding from liver transection. The primary outcome measure was postoperative changes in liver function from baseline. Secondary outcomes included operating time, volume of intraoperative blood loss/transfusion, and time to resolution of ascites. The two groups were comparable in age, sex, site and size of the liver tumor, segment or lobe intended to be resected, and liver function reserve, and the results were not significant statistically. All patients underwent successful major hepatectomies using the assigned method, with the extent of major hepatectomy comparable in the two groups (P = 0.832). The Glissonean approach was associated with shorter hepatic inflow interruption (30.0 ± 12.0 min vs. 45.0 ± 13.0 min, P requirement for transfusion (0.0 ± 0.0 mL vs. 200.0 ± 109.0 mL, P < 0.0001), and more rapid resolution of ascites (9.5 ± 1.2 d vs. 15.3 ± 2.4 d, P < 0.001). Postoperative liver function measures were comparable in the two groups, and the results were not significant statistically. The Glissonean pedicle transection method is a feasible, effective, and safe technique for hepatic inflow control during the curative resection of large nodular HCCs.

  10. Response properties of whisker-associated primary afferent neurons following infraorbital nerve transection with microsurgical repair in adult rats.

    Science.gov (United States)

    Xiao, Bo; Zanoun, Rami R; Carvell, George E; Simons, Daniel J; Washington, Kia M

    2016-03-01

    The rodent whisker/trigeminal system, characterized by high spatial and temporal resolution, provides an experimental model for developing new therapies for improving sensory functions of damaged peripheral nerves. Here, we use controlled whisker stimulation and single-unit recordings of trigeminal ganglion cells to examine in detail the nature and time course of functional recovery of mechanoreceptive afferents following nerve transection with microsurgical repair of the infraorbital nerve (ION) branch of the trigeminal nerve in adult rats. Response measures include rapid vs. slow adaptation, firing rate, interspike intervals, latency, and angular (directional) tuning. Whisker-evoked responses, readily observable by 3 wk post-transection, recover progressively for at least the next 5 wk. All cells in transected animals, as in control cases, responded to deflections of single whiskers only, but topography within the ganglion was clearly disrupted. The time course and extent of recovery of quantitative response measures were receptor dependent. Cells displaying slowly adapting (SA) properties recovered more quickly than rapidly adapting (RA) populations, and for some response measures-notably evoked firing rates-closely approached or attained control levels by 8 wk post-transection. Angular tuning of RA cells was slightly better than control units, whereas SA tuning did not differ from control values. Nerve conduction times and refractory periods, examined separately using electrical stimulation of the ION, were slower than normal in all transected animals and poorly reflected recovery of whisker-evoked response latencies and interspike intervals. Results underscore the need for multiple therapeutic strategies that target different aspects of functional restitution following peripheral nerve injury. Copyright © 2016 the American Physiological Society.

  11. Distribution and Localization of 5-HT1A Receptors in the Rat Lumbar Spinal Cord after Transection and Deafferentation

    Science.gov (United States)

    Otoshi, Chad K.; Walwyn, Wendy M.; Tillakaratne, Niranjala J.K.; Zhong, Hui; Roy, Roland R.

    2009-01-01

    Abstract The serotonergic system is highly plastic, capable of adapting to changing afferent information in diverse mammalian systems. We hypothesized that removing supraspinal and/or peripheral input would play an important role in defining the distribution of one of the most prevalent serotonergic receptors, the 5-HT1A receptor (R), in the spinal cord. We investigated the distribution of this receptor in response to a complete thoracic (T7–T8) spinal cord transection (eliminating supraspinal input), or to spinal cord isolation (eliminating both supraspinal and peripheral input) in adult rats. Using two antibodies raised against either the second extracellular region (ECL2) or the third intracellular region (ICL3) of the 5-HT1AR, we compared the 5-HT1AR levels and distributions in specific laminae of the L3–L5 segments among the control, spinal cord–transected, and spinal cord–isolated groups. Each antibody labeled different populations of 5-HT1AR: ECL2 labeled receptors in the axon hillock, whereas ICL3 labeled receptors predominantly throughout the soma and proximal dendrites. Spinal cord transection increased the number of ECL2-positive cells in the medial region of laminae III–IV and lamina VII, and the mean length of the labeled axon hillocks in lamina IX. The number of ICL3-labeled cells was higher in lamina VII and in both the medial and lateral regions of lamina IX in the spinal cord–transected compared to the control group. In contrast, the length and number of ECL2-immunolabeled processes and ICL3-immunolabeled cells were similar in the spinal cord–isolated and control groups. Combined, these data demonstrate that the upregulation in 5-HT1AR that occurs with spinal cord transection alone is dependent on the presence of sensory input. PMID:19260781

  12. Distribution and localization of 5-HT(1A) receptors in the rat lumbar spinal cord after transection and deafferentation.

    Science.gov (United States)

    Otoshi, Chad K; Walwyn, Wendy M; Tillakaratne, Niranjala J K; Zhong, Hui; Roy, Roland R; Edgerton, V Reggie

    2009-04-01

    The serotonergic system is highly plastic, capable of adapting to changing afferent information in diverse mammalian systems. We hypothesized that removing supraspinal and/or peripheral input would play an important role in defining the distribution of one of the most prevalent serotonergic receptors, the 5-HT(1A) receptor (R), in the spinal cord. We investigated the distribution of this receptor in response to a complete thoracic (T7-T8) spinal cord transection (eliminating supraspinal input), or to spinal cord isolation (eliminating both supraspinal and peripheral input) in adult rats. Using two antibodies raised against either the second extracellular region (ECL(2)) or the third intracellular region (ICL(3)) of the 5-HT(1A)R, we compared the 5-HT(1A)R levels and distributions in specific laminae of the L3-L5 segments among the control, spinal cord-transected, and spinal cord-isolated groups. Each antibody labeled different populations of 5-HT(1A)R: ECL(2) labeled receptors in the axon hillock, whereas ICL(3) labeled receptors predominantly throughout the soma and proximal dendrites. Spinal cord transection increased the number of ECL(2)-positive cells in the medial region of laminae III-IV and lamina VII, and the mean length of the labeled axon hillocks in lamina IX. The number of ICL(3)-labeled cells was higher in lamina VII and in both the medial and lateral regions of lamina IX in the spinal cord-transected compared to the control group. In contrast, the length and number of ECL(2)-immunolabeled processes and ICL(3)-immunolabeled cells were similar in the spinal cord-isolated and control groups. Combined, these data demonstrate that the upregulation in 5-HT(1A)R that occurs with spinal cord transection alone is dependent on the presence of sensory input.

  13. Synchrotron X ray induced axonal transections in the brain of rats assessed by high-field diffusion tensor imaging tractography.

    Science.gov (United States)

    Serduc, Raphaël; Bouchet, Audrey; Pouyatos, Benoît; Renaud, Luc; Bräuer-Krisch, Elke; Le Duc, Géraldine; Laissue, Jean A; Bartzsch, Stefan; Coquery, Nicolas; van de Looij, Yohan

    2014-01-01

    Since approximately two thirds of epileptic patients are non-eligible for surgery, local axonal fiber transections might be of particular interest for them. Micrometer to millimeter wide synchrotron-generated X-ray beamlets produced by spatial fractionation of the main beam could generate such fiber disruptions non-invasively. The aim of this work was to optimize irradiation parameters for the induction of fiber transections in the rat brain white matter by exposure to such beamlets. For this purpose, we irradiated cortex and external capsule of normal rats in the antero-posterior direction with a 4 mm×4 mm array of 25 to 1000 µm wide beamlets and entrance doses of 150 Gy to 500 Gy. Axonal fiber responses were assessed with diffusion tensor imaging and fiber tractography; myelin fibers were examined histopathologically. Our study suggests that high radiation doses (500 Gy) are required to interrupt axons and myelin sheaths. However, a radiation dose of 500 Gy delivered by wide minibeams (1000 µm) induced macroscopic brain damage, depicted by a massive loss of matter in fiber tractography maps. With the same radiation dose, the damage induced by thinner microbeams (50 to 100 µm) was limited to their paths. No macroscopic necrosis was observed in the irradiated target while overt transections of myelin were detected histopathologically. Diffusivity values were found to be significantly reduced. A radiation dose ≤ 500 Gy associated with a beamlet size of < 50 µm did not cause visible transections, neither on diffusion maps nor on sections stained for myelin. We conclude that a peak dose of 500 Gy combined with a microbeam width of 100 µm optimally induced axonal transections in the white matter of the brain.

  14. Synchrotron X ray induced axonal transections in the brain of rats assessed by high-field diffusion tensor imaging tractography.

    Directory of Open Access Journals (Sweden)

    Raphaël Serduc

    Full Text Available Since approximately two thirds of epileptic patients are non-eligible for surgery, local axonal fiber transections might be of particular interest for them. Micrometer to millimeter wide synchrotron-generated X-ray beamlets produced by spatial fractionation of the main beam could generate such fiber disruptions non-invasively. The aim of this work was to optimize irradiation parameters for the induction of fiber transections in the rat brain white matter by exposure to such beamlets. For this purpose, we irradiated cortex and external capsule of normal rats in the antero-posterior direction with a 4 mm×4 mm array of 25 to 1000 µm wide beamlets and entrance doses of 150 Gy to 500 Gy. Axonal fiber responses were assessed with diffusion tensor imaging and fiber tractography; myelin fibers were examined histopathologically. Our study suggests that high radiation doses (500 Gy are required to interrupt axons and myelin sheaths. However, a radiation dose of 500 Gy delivered by wide minibeams (1000 µm induced macroscopic brain damage, depicted by a massive loss of matter in fiber tractography maps. With the same radiation dose, the damage induced by thinner microbeams (50 to 100 µm was limited to their paths. No macroscopic necrosis was observed in the irradiated target while overt transections of myelin were detected histopathologically. Diffusivity values were found to be significantly reduced. A radiation dose ≤ 500 Gy associated with a beamlet size of < 50 µm did not cause visible transections, neither on diffusion maps nor on sections stained for myelin. We conclude that a peak dose of 500 Gy combined with a microbeam width of 100 µm optimally induced axonal transections in the white matter of the brain.

  15. Effect of partial and complete posterior cruciate ligament transection on medial meniscus: A biomechanical evaluation in a cadaveric model

    Directory of Open Access Journals (Sweden)

    Shu-guang Gao

    2013-01-01

    Full Text Available Background: The relationship between medial meniscus tear and posterior cruciate ligament (PCL injury has not been exactly explained. We studied to investigate the biomechanical effect of partial and complete PCL transection on different parts of medial meniscus at different flexion angles under static loading conditions. Materials and Methods: Twelve fresh human cadaveric knee specimens were divided into four groups: PCL intact (PCL-I, anterolateral bundle transection (ALB-T, posteromedial bundle transection (PMB-T and PCL complete transection (PCL-T group. Strain on the anterior horn, body part and posterior horn of medial meniscus were measured under different axial compressive tibial loads (200-800 N at 0°, 30°, 60° and 90° knee flexion in each groups respectively. Results: Compared with the PCL-I group, the PCL-T group had a higher strain on whole medial meniscus at 30°, 60° and 90° flexion in all loading conditions and at 0° flexion with 400, 600 and 800 N loads. In ALB-T group, strain on whole meniscus increased at 30°, 60° and 90° flexion under all loading conditions and at 0° flexion with 800 N only. PMB-T exihibited higher strain at 0° flexion with 400 N, 600 N and 800 N, while at 30° and 60° flexion with 800 N and at 90° flexion under all loading conditions. Conclusions: Partial PCL transection triggers strain concentration on medial meniscus and the effect is more pronounced with higher loading conditions at higher flexion angles.

  16. Tactile cues significantly modulate the perception of sweat-induced skin wetness independently of the level of physical skin wetness.

    Science.gov (United States)

    Filingeri, Davide; Fournet, Damien; Hodder, Simon; Havenith, George

    2015-06-01

    Humans sense the wetness of a wet surface through the somatosensory integration of thermal and tactile inputs generated by the interaction between skin and moisture. However, little is known on how wetness is sensed when moisture is produced via sweating. We tested the hypothesis that, in the absence of skin cooling, intermittent tactile cues, as coded by low-threshold skin mechanoreceptors, modulate the perception of sweat-induced skin wetness, independently of the level of physical wetness. Ten males (22 yr old) performed an incremental exercise protocol during two trials designed to induce the same physical skin wetness but to induce lower (TIGHT-FIT) and higher (LOOSE-FIT) wetness perception. In the TIGHT-FIT, a tight-fitting clothing ensemble limited intermittent skin-sweat-clothing tactile interactions. In the LOOSE-FIT, a loose-fitting ensemble allowed free skin-sweat-clothing interactions. Heart rate, core and skin temperature, galvanic skin conductance (GSC), and physical (w(body)) and perceived skin wetness were recorded. Exercise-induced sweat production and physical wetness increased significantly [GSC: 3.1 μS, SD 0.3 to 18.8 μS, SD 1.3, P 0.05). However, the limited intermittent tactile inputs generated by the TIGHT-FIT ensemble reduced significantly whole-body and regional wetness perception (P < 0.01). This reduction was more pronounced when between 40 and 80% of the body was covered in sweat. We conclude that the central integration of intermittent mechanical interactions between skin, sweat, and clothing, as coded by low-threshold skin mechanoreceptors, significantly contributes to the ability to sense sweat-induced skin wetness.

  17. Patterned nonadhesive surfaces: superhydrophobicity and wetting regime transitions.

    Science.gov (United States)

    Nosonovsky, Michael; Bhushan, Bharat

    2008-02-19

    Nonadhesive and water-repellent surfaces are required for many tribological applications. We study mechanisms of wetting of patterned superhydrophobic Si surfaces, including the transition between various wetting regimes during microdroplet evaporation in environmental scanning electron microscopy (ESEM) and for contact angle and contact angle hysteresis measurements. Wetting involves interactions at different scale levels: macroscale (water droplet size), microscale (surface texture size), and nanoscale (molecular size). We propose a generalized formulation of the Wenzel and Cassie equations that is consistent with the broad range of experimental data. We show that the contact angle hysteresis involves two different mechanisms and how the transition from the metastable partially wetted (Cassie) state to the homogeneously wetted (Wenzel) state depends upon droplet size and surface pattern parameters.

  18. Using wet microalgae for direct biodiesel production via microwave irradiation.

    Science.gov (United States)

    Cheng, Jun; Yu, Tao; Li, Tao; Zhou, Junhu; Cen, Kefa

    2013-03-01

    To address the large energy consumption of microalgae dewatering and to simplify the conventional two-step method (cellular lipid extraction and lipid transesterification) for biodiesel production, a novel process for the direct conversion of wet microalgae biomass into biodiesel by microwave irradiation is proposed. The influences of conventional thermal heating and microwave irradiation on biodiesel production from wet microalgae biomass were investigated. The effects of using the one-step (simultaneous lipid extraction and transesterification) and two-step methods were also studied. Approximately 77.5% of the wet microalgal cell walls were disrupted under microwave irradiation. The biodiesel production rate and yield from wet microalgae biomass obtained through the one-step process using microwave irradiation were 6-fold and 1.3-fold higher than those from wet microalgae obtained through the two-step process using conventional heating.

  19. The Crustal Structure of the Central Iberian Zone form the ALCUDIA Deep Seismic Reflection transect.

    Science.gov (United States)

    Martí, D.

    2009-04-01

    The ALCUDIA transect is a 250 km long, vertical incidence Vibroseis seismic reflection profile acquired in 2007. It extends IBERSEIS transect to the N and NE imaging from within the Ossa Morena Zone (OMZ) to the Central Iberian Zone (CIZ) from 20 km south of Fuenteovejuna in the S to Toledo in the N. The southern part of the transect samples the suture zone between the OMZ and the CIZ. It continues in a N-NE direction crossing the Pedroches batholith and a series of relatively long wavelength synclinal structures limited by sub-vertical and relatively narrow folds (e.g. the Almaden syncline, the Alcudia anticline). Lower Paleozoic quartzites and slates cover most of these synclynal structures. Farther to the N, the profile crosses several major faults system (e.g Santa Elena and Toledo) . The acquisition parameters, 35 m station spacing, 70 m VP spacing resulted in a 60-90 fold high resolution seismic reflection image. A 20 s long Vibroseis sweep with frequencies between 8-120 Hz was recorded by a 400 station recording cable a long a 14 km long split spread configuration. The new processing sequence significantly increased the signal-to-noise ratio. It includes: crooked line geometry, geometrical divergence corrections, elevation statics, surface-wave attenuation, surface consistent zero-phase spiking deconvolution, time-variant band pass filtering., refraction and residual static corrections velocity analysis, NMO, surface consistent amplitude balancing, CMP stacking F-X deconvolution. The seismic image reveals the geometry of the suture between the OMZ and the CIZ. This is a reworked transpression suture (the Badajoz-Cordoba Sherar zone) includes the Central Unit (CU) as a north dipping wedge structure limited by two bands of reflectors that reach the middle crust (5 s twtt). This CU includes amphibolites with some oceanic affinity, orthogneisses, paragneisses, schists and minor amounts of peridotites. To the north the upper crust shows a moderate reflectivity

  20. Wetting hysteresis of nanodrops on nanorough surfaces

    Science.gov (United States)

    Chang, Cheng-Chung; Sheng, Yu-Jane; Tsao, Heng-Kwong

    2016-10-01

    Nanodrops on smooth or patterned rough surfaces are explored by many-body dissipative particle dynamics to demonstrate the influence of surface roughness on droplet wetting. On a smooth surface, nanodrops exhibit the random motion and contact angle hysteresis is absent. The diffusivity decays as the intrinsic contact angle (θY) decreases. On a rough surface, the contact line is pinned and the most stable contact angle (θY') is acquired. The extent of contact angle hysteresis (Δ θ ) is determined by two approaches, which resemble the inflation-deflation method and inclined plane method for experiments. The hysteresis loop is acquired and both approaches yield consistent results. The influences of wettability and surface roughness on θY' and Δ θ are examined. θY' deviates from that estimated by the Wenzel or Cassie-Baxter models. This consequence can be explained by the extent of impregnation, which varies with the groove position and wettability. Moreover, contact angle hysteresis depends more on the groove width than the depth.