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Sample records for bedding and linens

  1. Properties and mesostructural characteristics of linen fiber reinforced self-compacting concrete in slender columns

    OpenAIRE

    Sabry A. Ahmed

    2013-01-01

    In this study the linen fibers were used to reinforce self-compacting concrete (SCC) with 2 and 4 kg/m3 contents; then their effects on the fresh and hardened properties of SCC were investigated. Furthermore, three circular slender columns were cast using both plain and linen fiber reinforced (LFR) SCC in order to study the variations of hardened properties and mesostructural characteristics along the columns height. The addition of linen fibers to SCC reduced its workability and affected its...

  2. Linen in Ancient Egypt

    Directory of Open Access Journals (Sweden)

    dr.Rehab Mahmoud Ahmed Elsharnouby

    2014-01-01

    Full Text Available Egypt was famous through the Ancient Near East for both weaving linen cloth and the produced quantities. Cloth was sent as expensive gifts from one king to another and given to a laborer as wages in return for his work. Cloth was regarded as an essential element in everyday life as it could be used for everything: clothing, bedding, trappings for animals, or sails of a ship. It was in fact one of the most widely used item throughout Ancient Egypt. Although other textile fibers were used in Pharaonic Egypt, namely, sheep's wool, goat hair and a form of coir, the majority of textiles were made from the plant Linum usitatissimum, flax. Cloth made from this fiber is defined as linen. The research starts with a brief definition of the flax, and then reviews the scenes representing the sowing and the harvesting of its seeds. It also focuses on the way of removing the seeds heads, the preparing of the flax for spinning: retting, beating and scutching. After that, it deals with transforming flax into orderly lengths, and rolling it into balls or coils. The researcher as well studies the Ancient Egyptian spinning techniques: grasped spindle, support spindle and drop spinning; the different types of weaving: tabby weaves, basket weaves, tapestry weaves and warps-patterned weave and the types of looms that were in use in Egypt, namely, the horizontal and vertical looms.

  3. Properties and mesostructural characteristics of linen fiber reinforced self-compacting concrete in slender columns

    Directory of Open Access Journals (Sweden)

    Sabry A. Ahmed

    2013-06-01

    Full Text Available In this study the linen fibers were used to reinforce self-compacting concrete (SCC with 2 and 4 kg/m3 contents; then their effects on the fresh and hardened properties of SCC were investigated. Furthermore, three circular slender columns were cast using both plain and linen fiber reinforced (LFR SCC in order to study the variations of hardened properties and mesostructural characteristics along the columns height. The addition of linen fibers to SCC reduced its workability and affected its self-compacting characteristics in a manner depending on the fiber content. Also, noticeable improvement in mechanical properties and slight reduction in unit weight and UPV were recorded. The hardened properties did not vary significantly along the height of columns, however, lower values were observed at the upper end of columns. The aggregate distribution was slightly more homogenous in case of LFRSCC, and the variation of fiber density along the height of columns was relatively high.

  4. Experimental study of bamboo using banana and linen fibre reinforced polymeric composites

    Directory of Open Access Journals (Sweden)

    Ramachandran M.

    2016-09-01

    Full Text Available The application of natural fibres such as bamboo, jute, banana, coir, linen and the like in Fibre Reinforced Polymeric (FRP composites have become so vital due to their high effective stiffness and strength, availability, low cost, specific strength, better dimensional stability and mechanical properties, eco-friendly and biodegradable as compared with synthetic fibres. The interest in natural fibre reinforced polymeric composites is rapidly springing up in terms of research and industrial applications. The increased applications of these natural fibres in such composites are a proof to this claim. The paper deals with the detailed study of bamboo fibre, banana fibre and linen fibre cut into 2−4 mm of length with epoxy resin having random orientations. Various tests like Impact test (IZOD and CHARPY test, Fourier Transform Infra-Red (FTIR test and Rockwell Hardness test were conducted on 10 specimens of bamboo epoxy resin composite, bamboo−banana epoxy resin composite and bamboo−linen epoxy resin composite. It is analysed and proved that bamboo−banana epoxy resin composite shows better results in Impact test with values of 4 Joules for Izod test and 5 Joules for Charpy test and in FTIR test, compatibility of fibres with polymers in bamboo−banana epoxy resin composite are the best while bamboo−linen epoxy resin composite shows better result in Rockwell hardness test with value of 40 RHN.

  5. Influence of Industrial Washing and Cyclic Fatigue on Slippage of Linen Fabric Threads along the Seam

    Directory of Open Access Journals (Sweden)

    Irina KORUNČAK

    2014-04-01

    Full Text Available All seams of garments shall withstand the established force effect in the longitudinal and transverse directions. Resistance to thread slippage along the seam is a major property of fabrics that is regulated by strict guidelines. In many research works, lining fabrics are chosen as the object of research as thread slippage is the most typical of them. What concerns the reports exploring slippage of linen fabric threads along the seam, just very few papers are available. Studies dealing with the influence made by industrial washing and cyclic load on the defect under investigation, thereby taking into account operational properties of garments are not readily available at all. The objective of the paper is to define the influence of industrial washing and cyclic tensile on slippage of linen fabric threads along the seam. For the research, five 100 % linen fabrics of plain weave have been selected. Control test specimens, unwashed and processed with different washing methods, have been analysed. Cyclic tensile of the test specimens has been carried out by a tensile machine “Tinius Olsen” at tensile force P = 20 N, tensile speed of 12.55 mm/s, number of cycles of 100. The carried-out testing has demonstrated that industrial washing decreased resistance of linen fabrics to thread slippage along the seam in the most cases. Analysis of the results obtained has shown that cyclic tensile led to particularly significant increase in the seam gap. DOI: http://dx.doi.org/10.5755/j01.ms.20.1.2486

  6. The effect of thermal aging and color pigments on the Egyptian linen properties evaluated by physicochemical methods

    Science.gov (United States)

    El-Gaoudy, H.; Kourkoumelis, N.; Varella, E.; Kovala-Demertzi, D.

    2011-11-01

    Archaeologists in Egypt discovered ancient colored textiles in great quantities in comparison with the analogous uncolored ones. Furthermore, the latter are far more deteriorated. Most research investigations into archaeological linen have been concerned with manufacture, restoration, and conservation but little information is available about the properties of the fibers, and particularly their chemical and physical properties after dyeing with natural dyes or painted with pigments. The aim of this study is to evaluate the physicochemical properties of Egyptian linen textiles coloring with a variety of pigments used in painting in ancient times after thermally aged to get linen samples which are similar as possible to the ancient linen textiles. The evaluations were based on Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction and tensile strength, and elongation measurements. Results showed that beyond cosmetic reasons, colored textiles did indeed play a role as protecting agents affecting strength and reducing thermal deterioration. Specifically, in the molecular level, pigments under study seem to interact to cellulose and lignin compounds of the aged linen while in the macroscopic level tensile and elongation parameters are altered. Electron microscopy confirms that pigment particles are deposited on and between the fibers' surfaces.

  7. Purification and Characterization of an Extracellular Proteinase from Brevibacterium-Linens ATCC-9174

    DEFF Research Database (Denmark)

    Rattray, F P; Bockelmann, W; Fox, P F

    1995-01-01

    An extracellular serine proteinase from Brevibacterium linens ATCC 9174 was purified to homogeneity. pH and temperature optima were 8,5 and 50 degrees C, respectively. The results for the molecular mass of the proteinase were 56 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis...... and 126 kDa by gel filtration, indicating that the native enzyme exists as a dimer. Mg2+ and Ca2+ activated the proteinase, as did NaCl; however, Hg2+ Fe2+, and Zn2+ caused strong inhibition. The sequence of the first 20 N-terminal amino acids was NH2-Ala-Lys- Asn...

  8. Natural cellulose fibers from switchgrass with tensile properties similar to cotton and linen.

    Science.gov (United States)

    Reddy, Narendra; Yang, Yiqi

    2007-08-01

    We report the production and characteristics of natural cellulose fibers obtained from the leaves and stems of switchgrass. In this paper, the composition, structure and properties of fibers obtained from the leaves and stem of switchgrass have been studied in comparison to the common natural cellulose fibers, such as cotton, linen and kenaf. The leaves and stems of switchgrass have tensile properties intriguingly similar to that of linen and cotton, respectively. Fibers were obtained from the leaves and stems of switchgrass using a simple alkaline extraction and the structure and properties of the fibers were studied. Fibers obtained from switchgrass leaves have crystallinity of 51%, breaking tenacity of 5.5 g per denier (715 MPa) and breaking elongation of 2.2% whereas the corresponding values for fibers obtained from switchgrass stems are 46%, 2.7 g per denier and 6.8%, respectively. Switchgrass is a relatively easy to grow and high yield biomass crop that can be source to partially substitute the natural and synthetic fibers currently in use. We hope that this research will stimulate interests in using switchgrass as a novel fiber crop in addition to being promoted as a potential source for biofuels. (c) 2007 Wiley Periodicals, Inc.

  9. Isolation and Identification of a Brevibacterium linens strain ...

    African Journals Online (AJOL)

    nitrophenol (PNP). Subsequent subcultures in agar, nutrient agar plates and agar slants by streaking led to isolation of pure colonies. The pure culture could degrade up to 300 mg/L PNP in presence of yeast extract. It was Gram positive rods, ...

  10. Ecofriendly laccase-hydrogen peroxide/ultrasound-assisted bleaching of linen fabrics and its influence on dyeing efficiency.

    Science.gov (United States)

    Abou-Okeil, A; El-Shafie, A; El Zawahry, M M

    2010-02-01

    This study evaluates the bleaching efficiency of enzymatically scoured linen fabrics using a combined laccase-hydrogen peroxide bleaching process with and without ultrasonic energy, with the goal of obtaining fabrics with high whiteness levels, well preserved tensile strength and higher dye uptake. The effect of the laccase enzyme and the combined laccase-hydrogen peroxide bleaching process with and without ultrasound has been investigated with regard to whiteness value, tensile strength, dyeing efficiency and dyeing kinetics using both reactive and cationic dyes. The bleached linen fabrics were characterized using X-ray diffraction and by measuring tensile strength and lightness. The dyeing efficiency and kinetics were characterized by measuring dye uptake and colour fastness. The results indicated that ultrasound was an effective technique in the combined laccase-hydrogen peroxide bleaching process of linen fabrics. The whiteness values expressed as lightness of linen fabrics is enhanced by using ultrasonic energy. The measured colour strength values were found to be slightly better for combined laccase-hydrogen peroxide/ultrasound-assisted bleached fabrics than for combined laccase-hydrogen peroxide for both reactive and cationic dyes. The fastness properties of the fabrics dyed with reactive dye were better than those obtained when using cationic dye. The time/dye uptake isotherms were also enhanced when using combined laccase-hydrogen peroxide/ultrasound-assisted bleached fabric, which confirms the efficiency of ultrasound in the combined oxidative bleaching process. The dyeing rate constant, half-time of dyeing and dyeing efficiency have been calculated and discussed.

  11. Effect of modifying additions on the physicomechanical properties of composites based on polyethylene and wastes from linen yarn production

    Science.gov (United States)

    Kayaks, Ya. A.; Bulmanis, V. N.; Reikhmane, S. A.; Tsiprin, M. G.

    1997-07-01

    This article examines the feasibility of using coupling agents to alleviate the shortcomings characteristics of materials that contain natural fibers: low water resistance and a high degree of heterogeneity. A determination is made of the effect of additions of polyisocyanate and stearic acid on the fluidity of the melts and the strainstrength properties and water resistance of polyethylene composites containing mixtures of wastes from linen yarn production. It is shown that an addition of stearic acid significantly improves the dispersion of fibers in the composites, which in turn leads to a reduction in melt fluidity and an increase in elastic modulus in the high-filler-content region compared to composites that do not have additions of stearic acid. Additions of polyisocyanate appreciably increase the strength and water resistance of the given composites.

  12. The influence of water sorption-desorption cycles on the mechanical properties of composites based on recycled polyolefine and linen yarn production waste

    Science.gov (United States)

    Bakradze, G.; Kajaks, J.; Reihmane, S.; Krutohvostov, R.; Bulmanis, V.

    2007-11-01

    The effect of water on the mechanical properties (tensile modulus, ultimate tensile strength, tensile strain, and specific work at break) of both chemically treated and untreated composites based on a recycled low-density polyethylene and linen yarn production waste is analyzed. It is found that three water sorption-desorption cycles change the tensile properties of both the materials irreversibly. This effect is considered as the result of partial fracture of the fiber-matrix interface.

  13. A problematic source of organic contamination of linen

    Science.gov (United States)

    Gove, H. E.; Mattingly, S. J.; David, A. R.; Garza-Valdes, L. A.

    1997-03-01

    Microscopic observations of a putative sample of linen from the Turin Shroud and samples of the linen wrapping of an Egyptian mummified ibis reveal that individual fibers of the cloth are surrounded by a coating produced by bacteria. Fungal material is also found among the threads. The question is whether the presence of this coating materially affects the age of cloth as obtained by carbon dating from what would be obtained if the actual cellulose of the flax from which the linen was made was dated. In particular what would be the affect on the age of the Turin Shroud? To obtain some answers to this question AMS radiocarbon measurements were made at the NSF Arizona AMS Facility at the University of Arizona on the collagen in bone and tissue samples from this ibis and of samples of the linen wrapping of the ibis cleaned by standard methods.

  14. Effect of the composition and concentration of fibrous wastes from linen yarn production on the physicomechanical properties of polyolefin composites

    Science.gov (United States)

    Kayaks, Ya. A.; Bulmanis, B. N.; Reikhmane, S. A.; Tsiprin, M. G.

    1997-05-01

    An analysis is made of the feasibility of using wastes from the production of linen yarm (scutch, spinning and carding refuse) to modify low-density polyethylene. The effect of the composition and concentration of wastes on the processing properties (melt index), physicomechanical indices (tensile strength, elastic modulus in bending), and water resistance of composites based on low-density polyethylene is studied. It is found that the melt index decreases with an increase in the content of filler and that even a composite with a high filler content (40-50% by weight) maintains values of 0.2-0.3 g/10 min. The elastic modulus in bending increases with an increase in the content of waste, regardless of the nature of the latter. Tensile strength increases slightly and depends on the choice of filler. This result, combined with the reducation in the scatter of values of elastic modulus with an increase in filler concentration, is an indicator of the relatively high degree of heterogeneity of the systems that were studied. The water resistance of the composites decreases with an increase in filleer content. To reduce the heterogeneity of the systems, mixing should be intensified and modifiers such as stearic acid and polyisocyanates should be added.

  15. Pakistan's textile and clothing sector and its future in the European Union

    NARCIS (Netherlands)

    K.A. Siegmann (Karin Astrid)

    2006-01-01

    textabstractA large number of the European community use bed-linen supplied by Pakistan. In 2005, the South Asian economy was the largest supplier of bed-linen to the union (Aziz, 2006). The European Union (EU) is Pakistan's largest trading partner, with textiles and clothing (T&C) accounting for

  16. Relation between D/H ratios and 18O /16O ratios in cellulose from linen and maize - Implications for paleoclimatology and for sindonology

    Science.gov (United States)

    DeNiro, Michael J.; Sternberg, Leonel D.; Marino, Bruno D.; Druzik, James R.

    1988-09-01

    The 18O /16O ratios of cellulose and the D/H ratios of cellulose nitrate were determined for linen, a textile produced from the fibers of the flax plant Linum usitatissimum, and for maize ( Zea mays) from a variety of geographic locations in Europe, the Middle East, and North and South America. The regression lines of δD values on δ 18O values had slopes of 5.4 and 5.8 for the two species. Statistical analysis of results reported in the only other study in which samples of a single species (the silver fir Abies pindrow) that grew under a variety of climatic conditions were analyzed yielded slopes of ~6 when δD values of cellulose nitrate were regressed on δ 18O values of cellulose. The occurrence of this previously unrecognized relationship in three species suggests it may obtain in other plants as well. Determining the basis for this relationship, which is not possible given current understanding of fractionation of the isotopes of oxygen and hydrogen by plants, should lead to increased understanding of how D/H and 18O /16O ratios in cellulose isolated from fossil plants are related to paleoclimates. The separation of most linen samples from Europe from those originating in the Middle East when δD values are plotted against δ 18O values suggests it may be possible to use the isotope ratios of cellulose prepared from the Shroud of Turin to resolve the controversy concerning its geographic origin.

  17. Applying lean Six Sigma to reduce linen loss in an acute care hospital

    African Journals Online (AJOL)

    Applying lean Six Sigma to reduce linen loss in an acute care hospital. ... International Journal of Engineering, Science and Technology ... This paper describes a case study in an acute care hospital that formed a cross-functional team to apply the Lean Six Sigma problem solving methodology and tools to improve the linen ...

  18. [Can industrial laundry remove Bacillus cereus from hospital linen?].

    Science.gov (United States)

    Yoh, Myonsun; Matsuyama, Junko; Shime, Akiko; Okayama, Kana; Sakamoto, Rei; Honda, Takeshi

    2010-09-01

    Contaminated hospital linen has caused some cases of Bacillus cereus bacteremia in Japan. We analyzed the disinfection efficacy of industrial washing of hospital towels and sheets by counting the number of B. cereus on linen before and after washing. That before washing averaged 7.6 cells/cm2 on unwashed sheets, decreasing to 1.2 cells/cm2 after washing. That on unwashed towels, however, averaged 10(6) cells/cm2 before washing and 1096 cells/cm2 after washing, which was very high and suggested the possibility of causing nosocomial infection.

  19. Efficacy of machine laundering to eradicate head lice: recommendations to decontaminate washable clothes, linens, and fomites.

    Science.gov (United States)

    Izri, Arezki; Chosidow, Olivier

    2006-01-15

    The efficacy of machine laundering to eradicate head lice should be determined. Viable lice and nits were machine laundered using 3 washing programs (with water temperatures of 40 degrees C, 50 degrees C, and 60 degrees C), with and without detergent, and the results were compared with results for control lice and nits. A drying program was also used. Either washing done with a water temperature of at least 50 degrees C or drying is necessary to kill head lice and nits.

  20. Linen Most Useful: Perspectives on Structure, Chemistry, and Enzymes for Retting Flax

    OpenAIRE

    Akin, Danny E.

    2012-01-01

    The components of flax (Linum usitatissimum) stems are described and illustrated, with reference to the anatomy and chemical makeup and to applications in processing and products. Bast fiber, which is a major economic product of flax along with linseed and linseed oil, is described with particular reference to its application in textiles, composites, and specialty papers. A short history of retting methods, which is the separation of bast fiber from nonfiber components, is presented with emph...

  1. Linen most useful: perspectives on structure, chemistry, and enzymes for retting flax.

    Science.gov (United States)

    Akin, Danny E

    2013-01-01

    The components of flax (Linum usitatissimum) stems are described and illustrated, with reference to the anatomy and chemical makeup and to applications in processing and products. Bast fiber, which is a major economic product of flax along with linseed and linseed oil, is described with particular reference to its application in textiles, composites, and specialty papers. A short history of retting methods, which is the separation of bast fiber from nonfiber components, is presented with emphasis on water retting, field retting (dew retting), and experimental methods. Past research on enzyme retting, particularly by the use of pectinases as a potential replacement for the current commercial practice of field retting, is reviewed. The importance and mechanism of Ca(2+) chelators with pectinases in retting are described. Protocols are provided for retting of both fiber-type and linseed-type flax stems with different types of pectinases. Current and future applications are listed for use of a wide array of enzymes to improve processed fibers and blended yarns. Finally, potential lipid and aromatic coproducts derived from the dust and shive waste streams of fiber processing are indicated.

  2. Physicochemical characterization of thermally aged Egyptian linen dyed with organic natural dyestuffs

    Science.gov (United States)

    Kourkoumelis, N.; El-Gaoudy, H.; Varella, E.; Kovala-Demertzi, D.

    2013-08-01

    A number of organic natural dyestuffs used in dyeing in ancient times, i.e. indigo, madder, turmeric, henna, cochineal, saffron and safflower, have been used to colour Egyptian fabrics based on linen. Their physicochemical properties have been evaluated on thermally aged linen samples. The aged dyed linen samples were thoroughly examined by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD) and tensile strength and elongation measurements. It was found that, in the molecular level, dyes interact mainly with the cellulose compounds of the aged linen while in the macroscopic level tensile and elongation parameters are altered. Tensile strength is positively related to the dye treatment while elongation depends specifically on the type of the dye used. Results converge that the dyed textiles did indeed play a role as protecting agents affecting strength and reducing thermal deterioration.

  3. Evaluation of Deformation and Strength Characteristics of Composites Based on Low-Density Polyethylene and Linen Yarn Production Waste by the Methods of Mathematical Statistics

    Science.gov (United States)

    Lejnieks, J. E.; Kajaks, J. A.; Reihmane, S. A.

    2004-01-01

    The possibilities of using various methods of mathematical statistics for processing and analyzing the results of deformation and strength tests on composites made from a low-density polyethylene and linen yarn production waste are evaluated. The hypothesis that the experimental strength data agree with the Gaussian distribution is examined by the Shapiro-Wilk test (W-test.) It is shown that the Gaussian distribution, both for systems unmodified and modified with diphenylmethane diisocyanate (DIC), is valid only for two parameters: the maximum tensile strength σmax and the elastic modulus E t. For the other parameters (the relative elongation ɛmax corresponding to σmax, the specific total work of failure A b), and the specific work of failure to the tensile strength A max), a non-Gaussian distribution is observed. An analysis of measurements for different specimens by the Bartlett test shows that the E t data have equal variances for both systems (with and without DIC), but for the system containing DIC, the σmax data have different variances. A two-factor ANOVA analysis reveals that DIC considerably affects the tensile strength and modulus of composites, but the influence of test conditions is a statistically significant factor only for the modulus. The coefficient of variation is considerably lower for σmax than for E t and can be used as a quantitative measure for the degree of heterogeneity of the composites investigated.

  4. Inhibition of Brevibacterium linens by Probiotics from Dairy Products

    Directory of Open Access Journals (Sweden)

    Alison M. Knox

    2005-01-01

    Full Text Available Brevibacterium linens is an important species in dairy products rendering a specific taste and aroma to numerous smear ripened and blue veined cheeses due to proteolysis. However, the presence of the species in South African blue veined cheeses is undesirable and consumers demand the product void of the species. Accordingly, numerous methods including microbial inhibition using fungi and bacterial probiotic cultures with possible inhibitory effects were applied in an attempt to inhibit the species. None of the fungi, however, proved to be successful, whereas Lactobacillus rhamnosus and Bifidobacterium lactis, two typical probiotic species applied in dairy products, showed inhibitory effects against B. linens when tested using the spot-on-lawn assay.

  5. [Evaluation of microbial contamination of linens in industrial laundry processes].

    Science.gov (United States)

    Sanna, Adriana; Coroneo, Valentina; Dessì, Sandro; Brandas, Valeria

    2013-01-01

    Laundering linens and protecting them from microbiological recontamination are critical issues for the hotel and food industries and especially for hospitals. This study was performed to evaluate a sample of industrial laundries in Sardinia (Italy), to assess their compliance with national hygienic and sanitary regulations, along the complete laundering process. Study results indicate that industrial laundering processes are effective and that better awareness of staff who handle laundered textiles is required to reduce the risk of recontamination.

  6. Genotypic and technological diversity of Brevibacterium linens strains for use as adjunct starter cultures in 'Pecorino di Filiano' cheese ripened in two different environments.

    Science.gov (United States)

    Bonomo, Maria Grazia; Cafaro, Caterina; Salzano, Giovanni

    2015-01-01

    Twenty-two Brevibacterium linens strains isolated from 'Pecorino di Filiano' cheese ripened in two different environments (natural cave and storeroom) were characterized and differentiated for features of technological interest and by genotypic methods, in order to select strains with specific features to be used as surface starter cultures. Results showed significant differences among strains on the basis of physiological and technological features, indicating heterogeneity within the species. A middle-low level of proteolytic activity was observed in 27.3 % of strains, while a small group (9.1 %) showed a high ability. Lipolytic activity was observed at three different temperatures and the highest value was detected at 20 °C with 13.6 % of strains, while an increase in temperature produced a slightly lower lipolysis in all strains. The evaluation of diacetyl production revealed that only 22.8 % of strains showed this ability, and most of them were isolated from product ripened in the natural cave. All strains exhibited only leu-aminopeptidase activity, with values more elevated in strains coming from the natural cave product. The combined analysis of genotypic results with the data obtained by the features of technological interest study established that the random amplified polymorphic DNA (RAPD) clusters obtained were composed not only of different genotypes but of different profiles based on technological properties too. This study demonstrated the importance of the ripening environment that affects the typical features of the artisanal product, leading to the selection of a specific surface microflora. Characterized strains could be associated within surface starters to standardize the production process of cheese, but preserving its typical organoleptic and sensory characteristics and improving the quality of the final product.

  7. Understanding and predicting bed humidity in fluidized bed granulation.

    Science.gov (United States)

    Hu, Xinhui; Cunningham, John; Winstead, Denita

    2008-04-01

    Bed humidity is a critical parameter that needs to be controlled in a fluidized bed granulation to ensure reliability. To predict and control the bed humidity during the fluidized bed granulation process, a simple model based on the mass conservation of moisture was developed. The moisture mass balance model quantitatively simulates the effects of spray rate, binder solution concentration, airflow rate, inlet air temperature, and dew point on the bed humidity. The model was validated by a series of granulations performed in different scale granulators including Glatt GPCG-1, GPCG-15, and GPCG-60. Good agreement was observed between the theoretical prediction and the measured loss on drying (LOD). The model developed in the current work enables us to choose the appropriate parameters for the fluidized bed granulation and can be used as a valuable tool in process scaling-up. 2007 Wiley-Liss, Inc

  8. Reduction of healthcare-associated infections in a long-term care brain injury ward by replacing regular linens with biocidal copper oxide impregnated linens.

    Science.gov (United States)

    Lazary, A; Weinberg, I; Vatine, J-J; Jefidoff, A; Bardenstein, R; Borkow, G; Ohana, N

    2014-07-01

    Contaminated textiles in hospitals contribute to endogenous, indirect-contact, and aerosol transmission of nosocomial related pathogens. Copper oxide impregnated linens have wide-spectrum antimicrobial, antifungal, and antiviral properties. Our aim was to determine if replacing non-biocidal linens with biocidal copper oxide impregnated linens would reduce the rates of healthcare-associated infections (HAI) in a long-term care ward. We compared the rates of HAI in two analogous patient cohorts in a head injury care ward over two 6-month parallel periods before (period A) and after (period B) replacing all the regular non-biocidal linens and personnel uniforms with copper oxide impregnated biocidal products. During period B, in comparison to period A, there was a 24% reduction in the HAI per 1000 hospitalization-days (p38.5°C) per 1000 hospitalization-days (p<0.01), and a 32.8% reduction in total number of days of antibiotic administration per 1000 hospitalization-days (p<0.0001). Accordingly there was saving of approximately 27% in costs of antibiotics, HAI-related treatments, X-rays, disposables, labor, and laundry, expenses during period B. The use of biocidal copper oxide impregnated textiles in a long-term care ward may significantly reduce HAI, fever, antibiotic consumption, and related treatment costs. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  9. Sea bed mapping and inspection

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    The conference has 24 presentations on the topics: Sea bed mapping, inspection, positioning, hydrography, marine archaeology, remote operation vehicles and computerized simulation technologies, oil field activities and plans, technological experiences and problems. (tk)

  10. Linen, Silver, Slaves, and Coffee: A Spatial Approach to Central Europe’s Entanglements with the Atlantic Economy

    Directory of Open Access Journals (Sweden)

    Weber, Klaus

    2015-12-01

    Full Text Available In German scholarship of the post-war period, the category of space was regarded as discredited, because of its abuse during the Nazi period. This applies in particular to the 1970s and 80s, when novel approaches in social and economic history were developed. Research on proto-industrialisation, broadly examining its internal structures, did not take into account the export orientation of Central Europe’s early modern commodity production. At the same time, the expanding research on Europe’s Atlantic empires, including the trans-Atlantic slave trade, did hardly take notice of the manufactures from the Holy Roman Empire, distributed all around the Atlantic basin. This paper examines those conditions favouring German proto-industries which are relevant for a ‘spatial approach’ to the phenomenon. It also covers the late medieval beginnings of this process, in order to demonstrate the continuity of Central Europe’s entanglement with the Atlantic world. The paper further emphasises that any future research using spatial categories must be aware of the ideological contamination of the German term ‘Raum’ during the 19th and 20th century. The interlace of economic and social history with historiography demands a compilation from current and older research literature, some of it on different regions and subjectsEn la escuela alemana del período de pos-guerra la categoría de espacio fue desprestigiada debido a los abusos sucedidos durante el período nazi. Esto se aplica en especial a los años de 1970 y 1980, cuando se desarrollaron los nuevos enfoques en historia social y económica. Las investigaciones sobre la proto-industrialización en Europa Central durante la Edad Moderna que examinan, en líneas generales, sus estructuras internas, no tuvieron en cuenta la dimensión espacial de las exportaciones de su producción. Al mismo tiempo, las crecientes investigaciones de los imperios europeos en el Atlántico, incluso del comercio de

  11. Seasonal Outbreak of Bacillus Bacteremia Associated With Contaminated Linen in Hong Kong.

    Science.gov (United States)

    Cheng, Vincent C C; Chen, Jonathan H K; Leung, Sally S M; So, Simon Y C; Wong, Shuk-Ching; Wong, Sally C Y; Tse, Herman; Yuen, Kwok-Yung

    2017-05-15

    A high seasonal incidence of Bacillus bacteremia was associated with the use of contaminated hospital linens. An outbreak investigation was conducted to study the incidence and source of Bacillus bacteremia during the baseline, outbreak, and postoutbreak period from 1 January 2012 through 31 July 2016 at a university-affiliated teaching hospital in Hong Kong. Replicate organism detection and counting plates were used for microbial screening of linen samples. The Bacillus species isolated from patient and linen samples were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and were phylogenetically analyzed. During the study period, a total of 113 207 blood cultures were collected from 43 271 patients, of which 978 (0.86%) specimens from 744 (1.72%) patients were identified as Bacillus species. The incidence of Bacillus bacteremia per 10 000 patient admissions and per 10 000 patient-days was significantly higher during the summer outbreak as compared with baseline and 1 year postoutbreak after cessation of the linen supply from the designated laundry and change of laundry protocol (39.97 vs 18.21 vs 2.27; 13.36 vs 5.61 vs 0.73; P Bacillus cereus group in 14 of 87 (16.1%) patients were phylogenetically associated with 9 linen sample isolates. Suboptimal conditions of hospital laundry contributed to the seasonal outbreak of Bacillus bacteremia. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

  12. Apparatus and process for controlling fluidized beds

    Science.gov (United States)

    Rehmat, Amirali G.; Patel, Jitendra G.

    1985-10-01

    An apparatus and process for control and maintenance of fluidized beds under non-steady state conditions. An ash removal conduit is provided for removing solid particulates from a fluidized bed separate from an ash discharge conduit in the lower portion of the grate supporting such a bed. The apparatus and process of this invention is particularly suitable for use in ash agglomerating fluidized beds and provides control of the fluidized bed before ash agglomeration is initiated and during upset conditions resulting in stable, sinter-free fluidized bed maintenance.

  13. THE BAUXITES AND JELAR - BEDS

    Directory of Open Access Journals (Sweden)

    Krešimir Sakač

    1993-12-01

    Full Text Available Minor bauxite deposits and occurrences were formed in technically disturbed environments in the middle part of the Adriatic geotectonic unit in Dinarides, contemporary with the clastic Jelar-beds in the Late Lutetian time. Uneven chemical composition of these Eocene bauxites, their sporadic occurrences in developed paleorelief as well as characteristic petrographic composition of the immediate overlying rocks point out at different genetical conditions (the paper is published in Croatian.

  14. Eco-friendly coloration of linen to ameliorate its practical approach

    OpenAIRE

    Pervez Md. Nahid; Inamdar Umarsharif Y.; Talukder Md. Eman; Mahmud Sakil; Habib Md. Ahsan; Kamruzzaman Md.; Cai Yingjie

    2017-01-01

    Reactive dyes are the perfect choice for dyeing of cellulosic fibers due to produce a wide gamut of bright colors with excellent color fastness, however environmental pollution is increasing in recent days seeing that of making use of inorganic salt and alkali. This paper offers a new avenue for eco-friendly dyeing of linen fiber by incorporating biodegradable alkaline organic salts in presence of three commercial reactive dyes and amongst them organic salt i.e. disodium maleate showed superi...

  15. Bed agglomeration characteristics of palm shell and corncob combustion in fluidized bed

    International Nuclear Information System (INIS)

    Chaivatamaset, Pawin; Sricharoon, Panchan; Tia, Suvit

    2011-01-01

    Bed particle agglomeration was studied experimentally in an atmospheric laboratory scale fluidized bed combustor using quartz sand as bed material. Palm shell and corncob were tested. The objectives of the study were (i) to describe the contributions of the biomass ash properties and the operating conditions on the bed agglomeration tendency in term of the bed defluidization time (t def ) and the extent of potassium accumulation in the bed (K/Bed) and (ii) to further elucidate the ash inorganic behaviors and the governing bed agglomeration mechanisms. Defluidization caused by the bed agglomeration was experienced in all experiments during combustion of these biomasses, as a consequence of the presence of potassium in biomass. The experimental results indicated that biomass ash characteristics were the significant influence on the bed agglomeration. The increasing bed temperature, bed particle size and static bed height and the decreasing fluidizing air velocity enhanced the bed agglomeration tendency. The SEM/EDS analyses on the agglomerates confirmed that the agglomeration was attributed to the formation of potassium silicate liquid enriched on the surface of quartz sand particles in conjunction with the high surface temperature of the burning biomass char particles. Thermodynamic examination based on the phase diagram analysis confirmed that the molten phase formation was responsible for the agglomeration. In this study, the high molten ash fraction resulting from the high potassium content in biomass promoted the agglomeration and thus defluidization. - Highlights: → Palm shell and corncob of Thailand are tested their bed agglomeration behaviors during fluidized bed combustion. → The increase of bed temperature, bed particle size and static bed height and the decrease of air velocity enhance bed agglomeration. → The formation of ash derived potassium silicate melts enriched on sand surface is the key process. → The collision between char and sand

  16. The Safety of Hospital Beds: Ingress, Egress, and In-Bed Mobility.

    Science.gov (United States)

    Morse, Janice M; Gervais, Pierre; Pooler, Charlotte; Merryweather, Andrew; Doig, Alexa K; Bloswick, Donald

    2015-01-01

    To explore the safety of the standard and the low hospital bed, we report on a microanalysis of 15 patients' ability to ingress, move about the bed, and egress. The 15 participants were purposefully selected with various disabilities. Bed conditions were randomized with side rails up or down and one low bed with side rails down. We explored the patients' use of the side rails, bed height, ability to lift their legs onto the mattress, and ability to turn, egress, and walk back to the chair. The standard bed was too high for some participants, both for ingress and egress. Side rails were used by most participants when entering, turning in bed, and exiting. We recommend that side rails be reconsidered as a means to facilitate in-bed movement, ingress, and egress. Furthermore, single deck height settings for all patients are not optimal. Low beds as a safety measure must be re-evaluated.

  17. Does Bedding Affect the Airway and Allergy?

    Directory of Open Access Journals (Sweden)

    RW Siebers

    2011-03-01

    Full Text Available Various cross-sectional and longitudinal studies have suggested that synthetic bedding is associated with asthma, allergic rhinitis and eczema while feather bedding seems to be protective. Synthetic bedding items have higher house dust mite allergen levels than feather bedding items. This is possibly the mechanism involved although fungal and bacterial proinflammatory compounds and volatile organic compounds may play a role. In this review we present and discuss the epidemiological evidence and suggest possible mechanisms. Primary intervention studies are required to show whether feather bedding is protective for the development of childhood asthma and allergic diseases while secondary intervention studies are required to potentially reduce symptoms and medication use in subjects with established disease.

  18. Determination of true bed thickness using folded bed model and borehole data

    Energy Technology Data Exchange (ETDEWEB)

    Xu, S.S.; Velasquillo-Martinez, L.G.; Grajales-Nishimura, J.M.; Murillo-Muneton, G. [Inst. Mexicano del Petroleo, Mexico City (Mexico); Garcia-Hernandez, J. [Petroleos Mexicanos Exploracion y Produccion, Tamaulipas (Mexico); Nieto-Samaniego, A.F. [Nacional Autonoma de Mexico Univ., Veracruz (Mexico). Centro de Geociencias

    2007-11-15

    The actual thickness of a given formation perpendicular to the bedding plane is known as the true bed thickness. Petroleum engineers rely on information regarding true bed thickness, particularly in dipping beds and in deviated holes because reservoir volume and isochore maps depend on these properties and not on the measured thickness. True bed thickness can be estimated from information gathered from well logs such as the dipmeter and borehole images. However, when deviations and dips exceed 10 degrees, corrections are needed. In this paper, a folded bed model was proposed to calculate the true bed thickness in the subsurface utilizing well log data. The value of true bed thickness (t) was shown to depend on the angle and the direction of the dip of the measured formation, as well as the drift angle and azimuth of the borehole. A case study from the Cantarell oil field in the southern Gulf of Mexico, offshore Campeche, was used to test the folded bed method. The model was shown to yield more uniform spatial change of the values of t, compared to the monoclinal bed model that often overestimates the average value of t. The maximum relative deviation of t from the monoclinal bed model reached 22.3 per cent and the maximum absolute deviation of t reached 34.5 m. The key factors that influence the values of t were found to be the bed dip, the dip difference between the top and base of the bed and the deviated angle of the well. The folded bed model yielded fewer changed values of the true bed thickness. 10 refs., 2 tabs., 9 figs.

  19. Measurement and modelling of bed shear induced by solitary waves

    Digital Repository Service at National Institute of Oceanography (India)

    JayaKumar, S.

    horizontal continental shelf. Measurements of bed shear stress, surface elevation and flow velocities were carried out. Periodic waves were also generated and the bed shear stresses measured over a horizontal bed were found to be comparable with the earlier...

  20. Heat and mass transfer enforcement of vibrating fluidized bed

    Science.gov (United States)

    Chu, Zhide; Yang, Junhong; Li, Xuhui; Song, Yang

    1994-12-01

    This paper briefly introduces the development of vibrating fluidized bed at home and abroad, elaborates the vibration properties of vibrating fluidized bed, the fluidizing velocity and pressure drop of the bed layer. It also deduces the non-steady state drying dynamic equations of vibrating fluidized bed, analyzes main factors which influence the drying rate and inquires into drying rules of fixed bed and vibrating fluidized bed.

  1. Bed care for patients in palliative settings: considering risks to caregivers and bed surfaces.

    Science.gov (United States)

    Fragala, Guy

    2015-02-01

    Ensuring patients are comfortable in bed is key to effective palliative care, but when moving and positioning patients in bed, health professionals face an occupational risk of injury. The turning and positioning (TAP) system is a new method of moving patients in bed, that evidence has shown to reduce the risk of injury to caregivers. Providing the correct bed surface is another aspect of bed care essential to the comfort of the palliative patient, and to aid wound prevention and treatment. It is important to take a patient-centred approach when considering the most appropriate bed surface patients. This article provides an overview and discussion of these two aspects of bed care for palliative patients.

  2. Incipient motion of gravel and coal beds

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    turbulent regime, identified based on physical reasoning and dimensional analysis, are the Shields parameter, particle Froude number, non-dimensional particle diameter and non-dimensional flow depth. Equations of critical bed shear stress ...

  3. Eco-friendly coloration of linen to ameliorate its practical approach

    Directory of Open Access Journals (Sweden)

    Pervez Md. Nahid

    2017-01-01

    Full Text Available Reactive dyes are the perfect choice for dyeing of cellulosic fibers due to produce a wide gamut of bright colors with excellent color fastness, however environmental pollution is increasing in recent days seeing that of making use of inorganic salt and alkali. This paper offers a new avenue for eco-friendly dyeing of linen fiber by incorporating biodegradable alkaline organic salts in presence of three commercial reactive dyes and amongst them organic salt i.e. disodium maleate showed superior result in terms of color strength (K/S, dye exhaustion (%, color fastness, tensile strength and crease recovery angle parameters that were evaluated by traditional technique.

  4. Bed Bug Infestations and Control Practices in China: Implications for Fighting the Global Bed Bug Resurgence.

    Science.gov (United States)

    Wang, Changlu; Wen, Xiujun

    2011-04-11

    The bed bug resurgence in North America, Europe, and Australia has elicited interest in investigating the causes of the widespread and increasing infestations and in developing more effective control strategies. In order to extend global perspectives on bed bug management, we reviewed bed bug literature in China by searching five Chinese language electronic databases. We conducted telephone interviews of staff from 77 Health and Epidemic Prevention Stations in six Chinese cities in November 2010. We also conducted telephone interviews of 68 pest control firms in two cities during March 2011. Two species of bed bugs (Cimex lectularius L. and Cimex hemipterus (F.)) are known to occur in China. These were common urban pests before the early1980s. Nationwide "Four-Pest Elimination" campaigns (bed bugs being one of the targeted pests) were implemented in China from 1960 to the early 1980s. These campaigns succeeded in the elimination of bed bug infestations in most communities. Commonly used bed bug control methods included applications of hot water, sealing of bed bug harborages, physical removal, and applications of residual insecticides (mainly organophosphate sprays or dusts). Although international and domestic travel has increased rapidly in China over the past decade (2000-2010), there have only been sporadic new infestations reported in recent years. During 1999-2009, all documented bed bug infestations were found in group living facilities (military dormitories, worker dormitories, and prisons), hotels, or trains. One city (Shenzhen city near Hong Kong) experienced significantly higher number of bed bug infestations. This city is characterized by a high concentration of migratory factory workers. Current bed bug control practices include educating residents, washing, reducing clutter, putting items under the hot sun in summer, and applying insecticides (pyrethroids or organophosphates). There have not been any studies or reports on bed bug insecticide

  5. Bed Bug Infestations and Control Practices in China: Implications for Fighting the Global Bed Bug Resurgence

    Directory of Open Access Journals (Sweden)

    Changlu Wang

    2011-04-01

    Full Text Available The bed bug resurgence in North America, Europe, and Australia has elicited interest in investigating the causes of the widespread and increasing infestations and in developing more effective control strategies. In order to extend global perspectives on bed bug management, we reviewed bed bug literature in China by searching five Chinese language electronic databases. We also conducted telephone interviews of 68 pest control firms in two cities during March 2011. In addition, we conducted telephone interviews to 68 pest control companies within two cities in March 2011. Two species of bed bugs (Cimex lectularius L. and Cimex hemipterus (F. are known to occur in China. These were common urban pests before the early1980s. Nationwide “Four-Pest Elimination” campaigns (bed bugs being one of the targeted pests were implemented in China from 1960 to the early 1980s. These campaigns succeeded in the elimination of bed bug infestations in most communities. Commonly used bed bug control methods included applications of hot water, sealing of bed bug harborages, physical removal, and applications of residual insecticides (mainly organophosphate sprays or dusts. Although international and domestic travel has increased rapidly in China over the past decade (2000–2010, there have only been sporadic new infestations reported in recent years. During 1999–2009, all documented bed bug infestations were found in group living facilities (military dormitories, worker dormitories, and prisons, hotels, or trains. One city (Shenzhen city near Hong Kong experienced significantly higher number of bed bug infestations. This city is characterized by a high concentration of migratory factory workers. Current bed bug control practices include educating residents, washing, reducing clutter, putting items under the hot sun in summer, and applying insecticides (pyrethroids or organophosphates. There have not been any studies or reports on bed bug insecticide

  6. Correlation between the mechanical properties and the amount of desorbed water for composites based on a recycled low-density polyethylene and linen yarn production waste

    Science.gov (United States)

    Bakradze, G. G.; Kajaks, J. A.; Reihmane, S. A.; Lejnieks, J. E.

    2007-09-01

    The effect of the amount of sorbed water on the mechanical properties (tensile modulus, tensile strength, unit work of fracture, and characteristic strains) of composites based on a recycled low-density polyethylene, both unmodified and modified with diphenylmethane diisocyanate (DIC), is an a lyzed by statistical methods. The results of tensile tests are found to depend on the amount of sorbed water considerably. The elastic modulus, the unit work of fracture, and the characteristic strains correlate linearly with the amount of water. It is found that the elastic modulus drops after the sorption of water, but then, during the desorption process, it is restored gradually and reaches its initial value after a 30-day drying. This is explained by the plasticizing effect of water on composite materials containing hydrophilic natural fibers. DIC improves the interfacial interaction of the fiber-matrix interface and slows down the desorption of water. The investigations of the main deformational and strength characteristics of the unmodified and modified systems showed that the ad verse effect of water completely disappeared after a 30-day drying. The same conclusion, with a 95% probability, can be drawn from the results of an analysis of variance (ANOVA).

  7. Heat transfer in a fixed bed and mass transfer in a counter-current moving bed

    Science.gov (United States)

    Dellaretti, F. O.

    The behavior of gas-solid reactors known as compact-fixed and moving beds, is analyzed from a theoretical viewpoint. For a compact fixed-bed the solution of the energy balance equations is obtained for the cases of a uniform temperature inside the solid pellets (i.e., the Biot number is zero) and for the case in which there are temperature gradients within the pellets (Bi 0). For short contact times, beds with Bi 0 have gas- and solid- temperatures which are greater than the temperatures within beds with Bi = 0. For long times, the situation is reversed. For a compact-moving bed the solution of the mass balance equations is obtained for the cases of a feed-solid with an oscillating concentration. For both types of beds there is an equivalence between mass transfer and energy transfer so that the solutions can be interchanged with suitable definitions of dimensionless variables.

  8. WTP Pretreatment Facility Potential Design Deficiencies--Sliding Bed and Sliding Bed Erosion Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, E. K. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-05-06

    This assessment is based on readily available literature and discusses both Newtonian and non-Newtonian slurries with respect to sliding beds and erosion due to sliding beds. This report does not quantify the size of the sliding beds or erosion rates due to sliding beds, but only assesses if they could be present. This assessment addresses process pipelines in the Pretreatment (PT) facility and the high level waste (HLW) transfer lines leaving the PT facility to the HLW vitrification facility concentrate receipt vessel.

  9. Effect of bed configuration on pebble flow uniformity and stagnation in the pebble bed reactor

    Energy Technology Data Exchange (ETDEWEB)

    Gui, Nan; Yang, Xingtuan [Institute of Nuclear and New Energy Technology of Tsinghua University, Key Laboratory of Advanced Reactor Engineering and Safety, Ministry of Education, Beijing 100084 (China); Tu, Jiyuan [Institute of Nuclear and New Energy Technology of Tsinghua University, Key Laboratory of Advanced Reactor Engineering and Safety, Ministry of Education, Beijing 100084 (China); School of Aerospace, Mechanical and Manufacturing Engineering, RMIT University, Melbourne, VIC 3083 (Australia); Jiang, Shengyao, E-mail: jiangshy@tsinghua.edu.cn [Institute of Nuclear and New Energy Technology of Tsinghua University, Key Laboratory of Advanced Reactor Engineering and Safety, Ministry of Education, Beijing 100084 (China)

    2014-04-01

    Highlights: • Pebble flow uniformity and stagnation characteristics are very important for HTR-PM. • Arc- and brachistochrone-shaped configuration effects are studied by DEM simulation. • Best bed configurations with uniform flow and no stagnated pebbles are suggested. • Detailed quantified characteristics of bed configuration effects are shown for explanation. - Abstract: Pebble flow uniformity and stagnation characteristics are very important for the design of pebble bed high temperature gas-cooled reactor. Pebble flows inside some specifically designed contraction configurations of pebble bed are studied by discrete element method. The results show the characteristics of stagnation rates, recycling rates, radial distribution of pebble velocity and residence time. It is demonstrated clearly that the bed with a brachistochrone-shaped configuration achieves optimum levels of flow uniformity and recycling rate concentration, and almost no pebbles are stagnated in the bed. Moreover, the optimum choice among the arc-shaped bed configurations is demonstrated too. Detailed information shows the quantified characteristics of bed configuration effects on flow uniformity. In addition, a good design of the pebble bed configuration is suggested.

  10. Environmental protection stability of river bed and banks using convex, concave, and linear bed sills.

    Science.gov (United States)

    Keshavarzi, Alireza; Noori, Lila Khaje

    2010-12-01

    River bed scourings are a major environmental problem for fish and aquatic habitat resources. In this study, to prevent river bed and banks from scouring, different types of bed sills including convex, concave and linear patterns were installed in a movable channel bed in a laboratory flume. The bed sills were tested with nine different arrangements and under different flow conditions. To find the most effective bed sill pattern, the scouring depth was measured downstream of the bed sill for a long experimental duration. The scour depth was measured at the middle and at the end of each experimental test for different ratios of the arch radius to the channel width [r/w]. The experimental results indicated that the convex pattern with r/w=0.35 produced minimum bed scouring depth at the center line whereas the concave pattern with r/w=0.23 produced the minimum scour depth at the wall banks. Therefore, the convex pattern was the most effective configuration for prevention of scouring at the center line of the river while the concave pattern was very effective to prevent scouring at the river banks. These findings can be suggested to be used in practical applications.

  11. [The effectiveness of a system using re-useable linens to reduce the expense of surgical operations].

    Science.gov (United States)

    Nagano, Kazuko; Morita, Saori; Shinoda, Maiko; Kawana, Yuki; Satou, Yuu; Yokozuka, Makito

    2013-10-01

    We introduced a system that uses re-useable linens for surgical operations in 2008. After 3 years from introduction we were able to reduce the expense of about yen 4,340,000 per year and CO2 production of 9,548 kg CO2 x m(-2) per year. We were convinced of the effect on reducing the expense of surgical operations and of decreasing the level of CO2 production that leads to global warming.

  12. Flow fields, bed shear stresses, and suspended bed sediment dynamics in bifurcations of a large river

    Science.gov (United States)

    Szupiany, R. N.; Amsler, M. L.; Hernandez, J.; Parsons, D. R.; Best, J. L.; Fornari, E.; Trento, A.

    2012-11-01

    Channel bifurcations associated with bars and islands are important nodes in braided rivers and may control flow partitioning and thus affect downstream confluences, as well as the formation and dynamics of bars. However, the morphodynamic processes associated with bar formation are poorly understood, and previous studies have largely concerned laboratory experiments, small natural streams, or numerical analyses with large Froude numbers, high slopes, and low Shields stresses. In these cases, the morphologic changes at bifurcations are relatively rapid, with predominant bed load transport and the suspended load playing a minor role. In this paper, the evolution of the flow structure and suspended bed sediment transport along four expansion-diffluence units in the Rio Paraná, Argentina, are described. The Rio Paraná is a large multichannel river with a bed composed of medium and fine sands and possesses low Froude numbers and high suspended bed material transport. Primary and secondary flow velocity components were measured with an acoustic Doppler current profiler (ADCP) along the expansion-diffluence units, and the backscatter signal of the ADCP was calibrated to allow simultaneous measurements of suspended bed sediment concentrations. The interactions between these variables show that the cores of primary flow velocity and suspended bed sediment concentration do not necessarily follow the thalweg at the bifurcation and that inertial effects on the suspended bed sediment may influence the morphodynamics of bar formation. It is suggested that changes in flow stage, as well as the presence of vegetation, may further increase the deposition of suspended bed sediment at the bar head. This study suggests that the ratio of suspended bed material to bed load is an important factor controlling the morphodynamics of bifurcations in large sand bed braided rivers.

  13. Reproduction of Bela Krajina Ornaments on Linen Fabrics by Screen Printing

    Directory of Open Access Journals (Sweden)

    Tatjana Rijavec

    2017-07-01

    Full Text Available Decorated Bela Krajina (White Carniolan towels called “otirači” are historical textiles, which represent an important cultural heritage of the Slovenian nation. This article presents the research of the suitability of the screen printing technique for reproducing ornaments from Bela Krajina towels, originally made with a technique called “tkaničenje”. The basic characteristics of woven fabrics, the colours of ornaments from Bela Krajina towels and the linen fabric, suitable for kitchen textiles, were analysed. Two Bela Krajina motifs were chosen for the decoration, namely a diamond and an eight-arm star. A comparison of the the colour diff erences, DE*ab , of the replica ornaments and the ornaments on the original towels made in blue and red colours showed a good match even after washing. It was confi rmed that the screen printing technique is suitable for decorating linen textiles with the original Bela Krajina ornaments, wherein the ornaments retaining their aesthetic and message values.

  14. Cardiac atrophy after bed rest and spaceflight

    Science.gov (United States)

    Perhonen, M. A.; Franco, F.; Lane, L. D.; Buckey, J. C.; Blomqvist, C. G.; Zerwekh, J. E.; Peshock, R. M.; Weatherall, P. T.; Levine, B. D.

    2001-01-01

    Cardiac muscle adapts well to changes in loading conditions. For example, left ventricular (LV) hypertrophy may be induced physiologically (via exercise training) or pathologically (via hypertension or valvular heart disease). If hypertension is treated, LV hypertrophy regresses, suggesting a sensitivity to LV work. However, whether physical inactivity in nonathletic populations causes adaptive changes in LV mass or even frank atrophy is not clear. We exposed previously sedentary men to 6 (n = 5) and 12 (n = 3) wk of horizontal bed rest. LV and right ventricular (RV) mass and end-diastolic volume were measured using cine magnetic resonance imaging (MRI) at 2, 6, and 12 wk of bed rest; five healthy men were also studied before and after at least 6 wk of routine daily activities as controls. In addition, four astronauts were exposed to the complete elimination of hydrostatic gradients during a spaceflight of 10 days. During bed rest, LV mass decreased by 8.0 +/- 2.2% (P = 0.005) after 6 wk with an additional atrophy of 7.6 +/- 2.3% in the subjects who remained in bed for 12 wk; there was no change in LV mass for the control subjects (153.0 +/- 12.2 vs. 153.4 +/- 12.1 g, P = 0.81). Mean wall thickness decreased (4 +/- 2.5%, P = 0.01) after 6 wk of bed rest associated with the decrease in LV mass, suggesting a physiological remodeling with respect to altered load. LV end-diastolic volume decreased by 14 +/- 1.7% (P = 0.002) after 2 wk of bed rest and changed minimally thereafter. After 6 wk of bed rest, RV free wall mass decreased by 10 +/- 2.7% (P = 0.06) and RV end-diastolic volume by 16 +/- 7.9% (P = 0.06). After spaceflight, LV mass decreased by 12 +/- 6.9% (P = 0.07). In conclusion, cardiac atrophy occurs during prolonged (6 wk) horizontal bed rest and may also occur after short-term spaceflight. We suggest that cardiac atrophy is due to a physiological adaptation to reduced myocardial load and work in real or simulated microgravity and demonstrates the plasticity

  15. Occupational Predisposition to Dermatophytes and other Agents of ...

    African Journals Online (AJOL)

    Michael Horsfall

    or hair in combs, hair brushes, clothing, furniture, public seats, caps, bed linens, towels, and hotel rugs. Jungerman and Schartzman, (1972) have reported that approximately 20% of human infections in urban areas are of animal origin while about 80% of human infections in rural areas are of animal origin. Occupation can ...

  16. Hoitajien ja vanhempien välinen vuorovaikutus

    OpenAIRE

    HASTRUP, ARJA

    2006-01-01

    Pikkulapsen mielenterveys määritellään lapsen kyvyksi kokea, säädellä ja ilmaista tunteita, muodostaa läheisiä ja turvallisia ihmissuhteita sekä tutkia ympäristöä ja oppia. Vanhempien ohjaus ja varhaisen vuorovaikutuksen tukeminen suojaavat lapsen kehitystä. Työntekijän ja vanhempien välinen hyvä vuorovaikutus on yksi edellytys intervention onnistumiselle, kun halutaan tukea lapsen ja vanhempien välistä vuorovaikutusta. Tutkielman tarkoituksena oli kuvata hoitotyöntekijöiden ja vanhempien...

  17. Thermal Analysis of Fluidized Bed and Fixed Bed Latent Heat Thermal Storage System

    Science.gov (United States)

    Beemkumar, N.; Karthikeyan, A.; Shiva Keshava Reddy, Kota; Rajesh, Kona; Anderson, A.

    2017-05-01

    Thermal energy storage technology is essential because its stores available energy at low cost. Objective of the work is to store the thermal energy in a most efficient method. This work is deal with thermal analysis of fluidized bed and fixed bed latent heat thermal storage (LHTS) system with different encapsulation materials (aluminium, brass and copper). D-Mannitol has been used as phase change material (PCM). Encapsulation material which is in orbicular shape with 4 inch diameter and 2 mm thickness orbicular shaped product is used. Therminol-66 is used as a heat transfer fluid (HTF). Arrangement of encapsulation material is done in two ways namely fluidized bed and fixed bed thermal storage system. Comparison was made between the performance of fixed bed and fluidized bed with different encapsulation material. It is observed that from the economical point of view aluminium in fluidized bed LHTS System has highest efficiency than copper and brass. The thermal energy storage system can be analyzed with fixed bed by varying mass flow rate of oil paves a way to find effective heat energy transfer.

  18. Loading and Unloading Weaned Pigs: Effects of Bedding Types, Ramp Angle, and Bedding Moisture

    Directory of Open Access Journals (Sweden)

    Arlene Garcia

    2014-12-01

    Full Text Available The use of non-slip surfaces during loading and unloading of weaned pigs plays an important role in animal welfare and economics of the pork industry. Currently, the guidelines available only suggest the use of ramps below 20° to load and unload pigs. Three ramp angles (0°, 10° or 20°, five bedding materials (nothing, sand, feed, wood shavings or wheat straw hay, two moistures (dry or wet bedding; >50% moisture over two seasons (>23.9 °C summer, <23.9 °C winter were assessed for slips/falls/vocalizations (n = 6,000 pig observations. “Score” was calculated by the sum of slips, falls, and vocalizations. With the exception of using feed as a bedding, all beddings provided some protection against elevated slips, falls, and vocalizations (P < 0.01. Providing bedding reduced (P < 0.05 scores regardless of whether the bedding was dry or wet. Scores increased as the slope increased (P < 0.01. Provision of bedding, other than feed, at slopes greater than zero, decreased slips, falls and vocalizations. The total time it took to load and unload pigs was

  19. Fungi solubilisation of low rank coal: performances of stirred tank, fluidised bed and packed bed reactors

    CSIR Research Space (South Africa)

    Oboirien, BO

    2013-02-01

    Full Text Available bioreactor represent slurry reactor systems enabling a comparative study. Direct comparison between these and the fixed bed bioreactor could not be carried as the corresponding particle sizes will result to a pressure drop in the fixed bed reactor. Coal...

  20. Bioremediation of contaminated soil beds and groundwater

    Indian Academy of Sciences (India)

    Bioremediation of contaminated soil beds and groundwater 45. 3. Simulation. The coupled set of ODEs is integrated by using IMSL (1991) subroutine DIVPAG. This employs Green's algorithm for stiff equations and is based on backward differentiation formulas. It requires an algebraic system of equations to be Solved at ...

  1. Incipient motion of gravel and coal beds

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    2Department of Civil Engineering, S R K R Engineering College, Bhimavaram. 534202, India e-mail: sdey@civil.iitkgp.ernet.in. MS received 15 January 2002. Abstract. An experimental study on incipient motion of gravel and coal beds under unidirectional steady-uniform flow is presented. Experiments were carried out in a ...

  2. It is time to wash the linen.

    Science.gov (United States)

    Bajaj, Rajiv

    2007-01-01

    The unethical practice of commissions in private healthcare requires an open debate since it leads to expensive and hazardous healthcare. Doctors are accused of being sales agents and law breakers, private hospitals resemble luxury hotels, the consumer has become fair game whenever he/she has money, and our profession and society are rendered insensitive to human suffering. At the root of this malaise is the unplanned promotion of healthcare as a free market product. This very complex product, which is required in times of stress and vulnerability, has been institutionalized as a business for profiteering in the absence of adequate checks and balances. The product is inherently unsuited for the free market because the consumer cannot be king unless he is empowered to choose wisely. Not enough has been done to address this deficiency. Efforts are required to strengthen non-profit health facilities; to make the consumer wise and minimize her/his exposure to doctored health information. The present unethical practices of our profession are not the fault of doctors or the Medical Council of India, and punitive measures would be inappropriate. We should start with the creation of a government health website which educates the public about modern healthcare, and by regulating advertisement of health products. Since health personnel, officials and news media are directly benefited by the present malpractices, corrective will require consumer participation.

  3. Fluidized Bed Asbestos Sampler Design and Testing

    Energy Technology Data Exchange (ETDEWEB)

    Karen E. Wright; Barry H. O' Brien

    2007-12-01

    A large number of samples are required to characterize a site contaminated with asbestos from previous mine or other industrial operations. Current methods, such as EPA Region 10’s glovebox method, or the Berman Elutriator method are time consuming and costly primarily because the equipment is difficult to decontaminate between samples. EPA desires a shorter and less costly method for characterizing soil samples for asbestos. The objective of this was to design and test a qualitative asbestos sampler that operates as a fluidized bed. The proposed sampler employs a conical spouted bed to vigorously mix the soil and separate fine particulate including asbestos fibers on filters. The filters are then analyzed using transmission electron microscopy for presence of asbestos. During initial testing of a glass prototype using ASTM 20/30 sand and clay fines as asbestos surrogates, fine particulate adhered to the sides of the glass vessel and the tubing to the collection filter – presumably due to static charge on the fine particulate. This limited the fines recovery to ~5% of the amount added to the sand surrogate. A second prototype was constructed of stainless steel, which improved fines recovery to about 10%. Fines recovery was increased to 15% by either humidifying the inlet air or introducing a voltage probe in the air space above the sample. Since this was not a substantial improvement, testing using the steel prototype proceeded without using these techniques. Final testing of the second prototype using asbestos suggests that the fluidized bed is considerably more sensitive than the Berman elutriator method. Using a sand/tremolite mixture with 0.005% tremolite, the Berman elutriator did not segregate any asbestos structures while the fluidized bed segregated an average of 11.7. The fluidized bed was also able to segregate structures in samples containing asbestos at a 0.0001% concentration, while the Berman elutriator method did not detect any fibers at this

  4. Circulating fluidized bed boilers design and operations

    CERN Document Server

    Basu, Prabir

    1991-01-01

    This book provides practicing engineers and students with insight into the design and operation of circulating fluidized bed (CFB) boilers. Through a combination of theoretical concepts and practical experience, this book gives the reader a basic understanding of the many aspects of this subject.Important environmental considerations, including solid waste disposal and predicted emissions, are addressed individually in separate chapters. This book places an emphasis on combustion, hydrodynamics, heat transfer, and material issues, and illustrates these concepts with numerous examples of pres

  5. Affective and ergonomic quality of a new bedding product

    OpenAIRE

    Ayas Pinar, Ebru

    2008-01-01

    It is essential that design of bed clothes in healthcare and other industries e.g. hospitality are suitable for the personnel when they perform bedding tasks. The bed clothes are important not just for patients’ experience of healthcare service, but also for serving as tools for nurses satisfaction and performance in the bed making task. Ergonomics and work load of the nurses are directly affected from design and development of product characteristics (material, weight etc.) and related tasks...

  6. Fluidized bed combustion and gasification of corncobs

    Energy Technology Data Exchange (ETDEWEB)

    Butuk, N.; Morey, R.V.

    1987-01-01

    A 15.2 cm (6 in) diameter fluidized bed reactor was evaluated in combustion and gasification modes using hammer milled corncobs with average particle size of 0.2 cm (0.08 in). Combustion tests were run at 10 and 32% w.b. moisture contents and 710 degrees C and 815 degrees C bed temperatures. Heat output rates of 13.4 to 16.2 MJ/h were achieved. Gasification tests were run at 10 and 22% w.b. moisture contents and 710 degrees C bed temperature, and heat output rates of 84 to 133 MJ/h were achieved. Particulates in the exhaust gases were determined in both the combustion and gasification modes of operation. The measurements showed the inadequacy of the flame holder for flaring the gas in the gasification mode. A combustion model based on elemental balances and the first law of thermodynamics was developed and compared to experimental results. The model adequately predicted fuel-air ratios and exhaust gas mass fractions in the combustion mode.

  7. Bed and bed-site reuse by western lowland gorillas (Gorilla g. gorilla) in Moukalaba-Doudou National Park, Gabon.

    Science.gov (United States)

    Iwata, Yuji; Ando, Chieko

    2007-01-01

    In this paper we describe bed (nest) and bed-site reuse by western lowland gorillas (Gorilla g. gorilla) in Moukalaba-Doudou National Park, south-eastern Gabon. During an eight-month study 44 bed sites and 506 beds were found. Among these, 38.6% of bed sites and 4.1% of beds were reused. We analyzed the monthly frequency of bed-site reuse in relation to rainfall, fruit abundance, and fruit consumption by the gorillas. The different frequency of bed-site reuse in the rainy and dry seasons was not significant. More bed-site reuse was observed during the fruiting season than during the non-fruiting season. Results from fecal analysis suggested that gorillas ate more fruit in the fruiting season than in the non-fruiting season. The frugivorous diet of western gorillas may possibly cause gorillas to stay in some areas and, consequently, reuse their bed sites. Reuse of bed sites by gorillas suggests their frequent return to an area where preferred fruit is readily available. A higher percentage of arboreal beds may also affect bed-site reuse, because of the shortage of bed material.

  8. Deleterious Thermal Effects Due To Randomized Flow Paths in Pebble Bed, and Particle Bed Style Reactors

    Science.gov (United States)

    Moran, Robert P.

    2013-01-01

    A review of literature associated with Pebble Bed and Particle Bed reactor core research has revealed a systemic problem inherent to reactor core concepts which utilize randomized rather than structured coolant channel flow paths. For both the Pebble Bed and Particle Bed Reactor designs; case studies reveal that for indeterminate reasons, regions within the core would suffer from excessive heating leading to thermal runaway and localized fuel melting. A thermal Computational Fluid Dynamics model was utilized to verify that In both the Pebble Bed and Particle Bed Reactor concepts randomized coolant channel pathways combined with localized high temperature regions would work together to resist the flow of coolant diverting it away from where it is needed the most to cooler less resistive pathways where it is needed the least. In other words given the choice via randomized coolant pathways the reactor coolant will take the path of least resistance, and hot zones offer the highest resistance. Having identified the relationship between randomized coolant channel pathways and localized fuel melting it is now safe to assume that other reactor concepts that utilize randomized coolant pathways such as the foam core reactor are also susceptible to this phenomenon.

  9. Variability of bed mobility in natural, gravel-bed channels and adjustments to sediment load at local and reach scales

    Science.gov (United States)

    Thomas E. Lisle; Jonathan M. Nelson; John Pitlick; Mary Ann Madej; Brent L. Barkett

    2000-01-01

    Abstract - Local variations in boundary shear stress acting on bed-surface particles control patterns of bed load transport and channel evolution during varying stream discharges. At the reach scale a channel adjusts to imposed water and sediment supply through mutual interactions among channel form, local grain size, and local flow dynamics that govern bed mobility...

  10. Medium optimization of protease production by Brevibacterium linens DSM 20158, using statistical approach

    Directory of Open Access Journals (Sweden)

    Khadija Shabbiri

    2012-09-01

    Full Text Available Various cultivation parameters were optimized for the production of extra cellular protease by Brevibacterium linens DSM 20158 grown in solid state fermentation conditions using statistical approach. The cultivation variables were screened by the Plackett-Burman design and four significant variables (soybean meal, wheat bran, (NH42SO4 and inoculum size were further optimized via central composite design (CCD using a response surface methodological approach. Using the optimal factors (soybean meal 12.0g, wheat bran 8.50g, (NH42SO4 0.45g and inoculum size 3.50%, the rate of protease production was found to be twofold higher in the optimized medium as compared to the unoptimized reference medium.

  11. Fluidized-bed reactors processes and operating conditions

    CERN Document Server

    Yates, John G

    2016-01-01

    The fluidized-bed reactor is the centerpiece of industrial fluidization processes. This book focuses on the design and operation of fluidized beds in many different industrial processes, emphasizing the rationale for choosing fluidized beds for each particular process. The book starts with a brief history of fluidization from its inception in the 1940’s. The authors present both the fluid dynamics of gas-solid fluidized beds and the extensive experimental studies of operating systems and they set them in the context of operating processes that use fluid-bed reactors. Chemical engineering students and postdocs as well as practicing engineers will find great interest in this book.

  12. "Therapeutic" bed rest in pregnancy: unethical and unsupported by data.

    Science.gov (United States)

    McCall, Christina A; Grimes, David A; Lyerly, Anne Drapkin

    2013-06-01

    "Therapeutic" bed rest continues to be used widely, despite evidence of no benefit and known harms. In this commentary, we summarize the Cochrane reviews of bed rest and propose an ethical argument for discontinuing this practice. Cochrane systematic reviews do not support "therapeutic" bed rest for threatened abortion, hypertension, preeclampsia, preterm birth, multiple gestations, or impaired fetal growth. This assessment has been echoed in other comprehensive reviews. Prescribing bed rest is inconsistent with the ethical principles of autonomy, beneficence, and justice. Hence, if bed rest is to be used, it should be only within a formal clinical trial.

  13. Housing and bed and board contract

    Directory of Open Access Journals (Sweden)

    Veselinović Janko

    2011-01-01

    Full Text Available In this work not only legal nature of catering services is analyzed, but also legal position of parties in it. Catering contract (Housing and Bed and Board Contract is unnamed in our country and the main source of law for this contract are business practices and usage. A lot of attention is paid to this question. Lack of legal norms for this area is general characteristic for most of the tourism contracts. In this contract its title is also debatable because term 'catering services' is not usually used in practice. Although this contract is unnamed in Comparative Law ,in tourist more developed countries there are more codified business practices from this area and there is more Case Law. Having in mind development of tourist economy adequate legal conditions in tourism contract are expected.

  14. The role of velocity, pressure, and bed stress fluctuations in bed load transport over bed forms: numerical simulation downstream of a backward-facing step

    Directory of Open Access Journals (Sweden)

    M. W. Schmeeckle

    2015-02-01

    Full Text Available Bed load transport over ripples and dunes in rivers exhibits strong spatial and temporal variability due to the complex turbulence field caused by flow separation at bedform crests. A turbulence-resolving flow model downstream of a backward-facing step, coupled with a model integrating the equations of motion of individual sand grains, is used to investigate the physical interaction between bed load motion and turbulence downstream of separated flow. Large bed load transport events are found to correspond to low-frequency positive pressure fluctuations. Episodic penetration of fluid into the bed increases the bed stress and moves grains. Fluid penetration events are larger in magnitude near the point of reattachment than farther downstream. Models of bed load transport over ripples and dunes must incorporate the effects of these penetration events of high stress and sediment flux.

  15. The role of velocity, pressure, and bed stress fluctuations in bed load transport over bed forms: numerical simulation downstream of a backward-facing step

    Science.gov (United States)

    Schmeeckle, M. W.

    2015-02-01

    Bed load transport over ripples and dunes in rivers exhibits strong spatial and temporal variability due to the complex turbulence field caused by flow separation at bedform crests. A turbulence-resolving flow model downstream of a backward-facing step, coupled with a model integrating the equations of motion of individual sand grains, is used to investigate the physical interaction between bed load motion and turbulence downstream of separated flow. Large bed load transport events are found to correspond to low-frequency positive pressure fluctuations. Episodic penetration of fluid into the bed increases the bed stress and moves grains. Fluid penetration events are larger in magnitude near the point of reattachment than farther downstream. Models of bed load transport over ripples and dunes must incorporate the effects of these penetration events of high stress and sediment flux.

  16. Fluidized bed combustion: mixing and pollutant limitation

    Energy Technology Data Exchange (ETDEWEB)

    Leckner, B. [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Energy Conversion

    1997-10-01

    Fluidized bed combustion (FBC) has been applied commercially during a few decades, and sufficient knowledge is gained to design boilers with sizes of up to several hundreds of megawatt thermal power (MW{sub th}). The knowledge of what goes on inside a large combustion chamber is still limited, however, and this impedes further optimization and efficient solution of problems that might occur. Despite this lack of knowledge the present survey deals with combustion chamber processes and discusses mixing and distribution of fuel and air in the combustion chamber and its importance for sulphur capture and reduction of emissions of nitrogen oxides. It is desirable to present the material in a general way and to cover the entire field of FBC. However, the scarce openly published information deals mostly with coal combustion in atmospheric circulating fluidized bed (CFB) combustors, and therefore this application will receive most attention, but reference is also made to pressurized combustion and to other fuels than coal. In this context the important work made in the LIEKKI project on the analysis of different fuels and on the influence of pressure should be especially pointed out. (orig.)

  17. INVESTIGATION OF FUEL CHEMISTRY AND BED PERFORMANCE IN A FLUIDIZED BED BLACK LIQUOR STEAM REFORMER

    Energy Technology Data Exchange (ETDEWEB)

    Kevin Whitty

    2003-12-01

    The University of Utah project ''Investigation of Fuel Chemistry and Bed Performance in a Fluidized Bed Black Liquor Steam Reformer'' (DOE award number DE-FC26-02NT41490) was developed in response to a solicitation for projects to provide technical support for black liquor and biomass gasification. The primary focus of the project is to provide support for a DOE-sponsored demonstration of MTCI's black liquor steam reforming technology at Georgia-Pacific's paper mill in Big Island, Virginia. A more overarching goal is to improve the understanding of phenomena that take place during low temperature black liquor gasification. This is achieved through five complementary technical tasks: (1) construction of a fluidized bed black liquor gasification test system, (2) investigation of bed performance, (3) evaluation of product gas quality, (4) black liquor conversion analysis and modeling and (5) computational modeling of the Big Island gasifier. Four experimental devices have been constructed under this project. The largest facility, which is the heart of the experimental effort, is a pressurized fluidized bed gasification test system. The system is designed to be able to reproduce conditions near the black liquor injectors in the Big Island steam reformer, so the behavior of black liquor pyrolysis and char gasification can be quantified in a representative environment. The gasification test system comprises five subsystems: steam generation and superheating, black liquor feed, fluidized bed reactor, afterburner for syngas combustion and a flue gas cooler/condenser. The three-story system is located at University of Utah's Industrial Combustion and Gasification Research Facility, and all resources there are available to support the research.

  18. Investigation of Fuel Chemistry and Bed Performance in a Fluidized Bed Black Liquor Steam Reformer

    Energy Technology Data Exchange (ETDEWEB)

    Kevin Whitty

    2007-06-30

    University of Utah's project entitled 'Investigation of Fuel Chemistry and Bed Performance in a Fluidized Bed Black Liquor Steam Reformer' (DOE Cooperative Agreement DE-FC26-02NT41490) was developed in response to a solicitation released by the U.S. Department of Energy in December 2001, requesting proposals for projects targeted towards black liquor/biomass gasification technology support research and development. Specifically, the solicitation was seeking projects that would provide technical support for Department of Energy supported black liquor and biomass gasification demonstration projects under development at the time.

  19. Scour and fill in cobble-bedded streams

    OpenAIRE

    Carling, P.A.

    1982-01-01

    Scour and deposition have been measured in two small cobble-bedded upland streams, for two years. Grids of scour chains were inserted in the bed and relocated after the passage of individual hydrographs. Scour, fill and the area of the bed affected by these processes were recorded. The relationship between mean scour or fill and maximum scour or fill is assessed. In addition, the relationship between the depth of scour and the sediment transport rate as bedload is discussed briefly.

  20. The effect of bed non-uniformities and porosity of particles on dryout in boiling particle beds

    International Nuclear Information System (INIS)

    Macbeth, R.V.; Mogford, D.J.; Willshire, S.J.

    1988-03-01

    This report relates to an on-going experimental programme concerned with the coolability of beds of reactor core debris or rubble immersed in a liquid coolant, as might occur in an accident situation. The objectives are to develop experimental techniques, improve the understanding of bed cooling mechanisms, determine dry-out limitations of various bed configurations and particle shapes and sizes and devise ways of improving bed coolability. The report concentrates on a recently discovered effect on bed coolability of particle porosity, such as exists in fragmented UO 2 fuel pellets. It is shown that porosity can lower bed dry-out powers by a factor of 4 or 5. A mechanism which explains the effect is presented. The report also gives results of bed non-uniformities obtained by mixing glass particles with the dielectrically heated 'ferrite' particles used in the experiments. (author)

  1. Fluidized-bed calciner with combustion nozzle and shroud

    International Nuclear Information System (INIS)

    Wielang, J.A.; Palmer, W.B.; Kerr, W.B.

    1977-01-01

    A nozzle employed as a burner within a fluidized bed is coaxially enclosed within a tubular shroud that extends beyond the nozzle length into the fluidized bed. The open-ended shroud portion beyond the nozzle end provides an antechamber for mixture and combustion of atomized fuel with an oxygen-containing gas. The arrangement provides improved combustion efficiency and excludes bed particles from the high-velocity, high-temperature portions of the flame to reduce particle attrition. 4 claims, 2 figures

  2. Experimental and numerical study of spouted bed fluif dynamics

    Directory of Open Access Journals (Sweden)

    C. R. Duarte

    2008-03-01

    Full Text Available Spouted beds, originally invented in Canada by Mathur and Gishler (1955 as an alternative to fluidized beds for handling coarse particles, are now widely studied in a variety of physical operations, such as drying, coating and granulation. In this work the particle velocity, minimum spouting flow rate and characteristic fluid-dynamic curves of the spouted bed were obtained using a Eulerian granular multiphase model. The computational work was significantly reduced for axisymmetric gas-solid flows. The experimental data obtained in two spouted bed configurations, conical-cylindrical and two-dimensional, were compared with the simulated results, showing good agreement

  3. Simulation Facilities and Test Beds for Galileo

    Science.gov (United States)

    Schlarmann, Bernhard Kl.; Leonard, Arian

    2002-01-01

    Galileo is the European satellite navigation system, financed by the European Space Agency (ESA) and the European Commission (EC). The Galileo System, currently under definition phase, will offer seamless global coverage, providing state-of-the-art positioning and timing services. Galileo services will include a standard service targeted at mass market users, an augmented integrity service, providing integrity warnings when fault occur and Public Regulated Services (ensuring a continuity of service for the public users). Other services are under consideration (SAR and integrated communications). Galileo will be interoperable with GPS, and will be complemented by local elements that will enhance the services for specific local users. In the frame of the Galileo definition phase, several system design and simulation facilities and test beds have been defined and developed for the coming phases of the project, respectively they are currently under development. These are mainly the following tools: Galileo Mission Analysis Simulator to design the Space Segment, especially to support constellation design, deployment and replacement. Galileo Service Volume Simulator to analyse the global performance requirements based on a coverage analysis for different service levels and degrades modes. Galileo System Simulation Facility is a sophisticated end-to-end simulation tool to assess the navigation performances for a complete variety of users under different operating conditions and different modes. Galileo Signal Validation Facility to evaluate signal and message structures for Galileo. Galileo System Test Bed (Version 1) to assess and refine the Orbit Determination &Time Synchronisation and Integrity algorithms, through experiments relying on GPS space infrastructure. This paper presents an overview on the so called "G-Facilities" and describes the use of the different system design tools during the project life cycle in order to design the system with respect to

  4. Pebble bed pebble motion: Simulation and Application

    Science.gov (United States)

    Cogliati, Joshua J.

    Pebble bed reactors (PBR) have moving graphite fuel pebbles. This unique feature provides advantages, but also means that simulation of the reactor requires understanding the typical motion and location of the granular flow of pebbles. This dissertation presents a method for simulation of motion of the pebbles in a PBR. A new mechanical motion simulator, PEBBLES, efficiently simulates the key elements of motion of the pebbles in a PBR. This model simulates gravitational force and contact forces including kinetic and true static friction. It's used for a variety of tasks including simulation of the effect of earthquakes on a PBR, calculation of packing fractions, Dancoff factors, pebble wear and the pebble force on the walls. The simulator includes a new differential static friction model for the varied geometries of PBRs. A new static friction benchmark was devised via analytically solving the mechanics equations to determine the minimum pebble-to-pebble friction and pebble-to-surface friction for a five pebble pyramid. This pyramid check as well as a comparison to the Janssen formula was used to test the new static friction equations. Because larger pebble bed simulations involve hundreds of thousands of pebbles and long periods of time, the PEBBLES code has been parallelized. PEBBLES runs on shared memory architectures and distributed memory architectures. For the shared memory architecture, the code uses a new O(n) lock-less parallel collision detection algorithm to determine which pebbles are likely to be in contact. The new collision detection algorithm improves on the traditional non-parallel O(n log(n)) collision detection algorithm. These features combine to form a fast parallel pebble motion simulation. The PEBBLES code provides new capabilities for understanding and optimizing PBRs. The PEBBLES code has provided the pebble motion data required to calculate the motion of pebbles during a simulated earthquake. The PEBBLES code provides the ability to

  5. Measurement and modeling of bed shear stress under solitary waves

    Digital Repository Service at National Institute of Oceanography (India)

    Jayakumar, S.; Guard, P.A.; Baldock, T.E.

    Direct measurements of bed shear stresses (using a shear cell apparatus) generated by non-breaking solitary waves are presented. The measurements were carried out over a smooth bed in laminar and transitional flow regimes (~ 10 sup (4) < R sub (e...

  6. Lithofacies and petrophysical properties of Portland Base Bed and Portland Whit Bed limestone as related to durability

    NARCIS (Netherlands)

    Dubelaar, C.W.; Engering, S.; Hees, R.P.J. van; Koch, R.; Lorenz, H.G.

    2003-01-01

    This study focuses on the differences in lithofacies and petrophysical properties of Base Bed and Whit Bed Portland limestone and the presumed relationships between these characteristics and the durability of this building stone. As Portland limestone probably will be used as a stone for several

  7. Lithofacies and Petrophysical Properties of Portland Base Bed and Portland Whit Bed Limestone as Related to Durability

    NARCIS (Netherlands)

    Dubelaar, C.W.; Engering, S.; Van Hees, R.P.J.; Koch, R.; Lorenz, H.G.

    2003-01-01

    This study focuses on the differences in lithofacies and petrophysical properties of Base Bed and Whit Bed Portland limestone and the presumed relationships between these characteristics and the durability of this building stone. As Portland limestone probably will be used as a stone for several

  8. Tidal asymmetry and variability of bed shear stress and sediment bed flux at a site in San Francisco Bay, USA

    Science.gov (United States)

    Brennan, Matthew L.; Schoellhamer, David H.; Burau, Jon R.; Monismith, Stephen G.; Winterwerp, J.C.; Kranenburg, C.

    2002-01-01

    The relationship between sediment bed flux and bed shear stress during a pair of field experiments in a partially stratified estuary is examined in this paper. Time series of flow velocity, vertical density profiles, and suspended sediment concentration were measured continuously throughout the water column and intensely within 1 meter of the bed. These time series were analyzed to determine bed shear stress, vertical turbulent sediment flux, and mass of sediment suspended in the water column. Resuspension, as inferred from near-bed measurements of vertical turbulent sediment flux, was flood dominant, in accordance with the flood-dominant bed shear stress. Bathymetry-induced residual flow, gravitational circulation, and ebb tide salinity stratification contributed to the flood dominance. In addition to this flow-induced asymmetry, the erodibility of the sediment appears to increase during the first 2 hours of flood tide. Tidal asymmetry in bed shear stress and erodibility help explain an estuarine turbidity maximum that is present during flood tide but absent during ebb tide. Because horizontal advection was insignificant during most of the observation periods, the change in bed mass can be estimated from changes in the total suspended sediment mass. The square wave shape of the bed mass time series indicates that suspended sediment rapidly deposited in an unconsolidated or concentrated benthic suspension layer at slack tides and instantly resuspended when the shear stress became sufficiently large during a subsequent tide. The variability of bed mass associated with the spring/neap cycle (about 60 mg/cm2) is similar to that associated with the semidiurnal tidal cycle.

  9. Fluid-dynamic behavior of flaxseed fluidized and spouted bed

    Directory of Open Access Journals (Sweden)

    Elza Brandão Santana

    2017-09-01

    Full Text Available ABSTRACT: Processing of particles in a moving bed, such as a fluidized bed or a spouting bed, is commonly used in the operations of drying, coating, and granulation of particulate systems. This process has applications in the chemical, pharmaceutical and, presently, agronomical industries, especially for seed treatment/coating. This research aimed to analyze the fluid-dynamic behavior of fluidized and spouting beds with different air temperatures and loads of flaxseeds (Linum usitatissimum L., with estimates of the fluid-dynamic parameters correlated to each process. The parameters were compared with the values obtained from classical correlations in the literature, with indications of associated percentages of deviation. Influence of fluid dynamics on the physiological quality of seeds was assessed by germination tests and the germination speed index. An analysis of the results indicated that seed processing was adequate for processing in dynamically active beds; however, temperatures above 50ºC in both beds caused significant reductions in the physiological quality of the seeds. Processing in a fluidized bed presented a smaller reduction of the physiological properties of the flaxseed.

  10. Heat-transfer characteristics of flowing and stationary particle-bed-type fusion-reactor blankets

    Energy Technology Data Exchange (ETDEWEB)

    Nietert, R.E.

    1983-02-01

    The following five appendices are included: (1) physical properties of materials, (2) thermal entrance length Nusselt number variations, (3) stationary particle bed temperature variations, (4) falling bed experimental data and calculations, and (5) stationary bed experimental data and calculations. (MOW)

  11. Heat-transfer characteristics of flowing and stationary particle-bed-type fusion-reactor blankets

    International Nuclear Information System (INIS)

    Nietert, R.E.

    1983-02-01

    The following five appendices are included: (1) physical properties of materials, (2) thermal entrance length Nusselt number variations, (3) stationary particle bed temperature variations, (4) falling bed experimental data and calculations, and (5) stationary bed experimental data and calculations

  12. Fixed-bed Reactor Dynamics and Control - A Review

    DEFF Research Database (Denmark)

    Jørgensen, S. B.

    1986-01-01

    The industrial diversity of fixed bed reactors offers a challenging and relevant set of control problems. These intricate problems arise due to the rather complex dynamics of fixed bed reactors and to the complexity of actual reactor configurations. Many of these control problems are nonlinear...... and multi-variable. During the last decade fixed bed reactor control strategies have been proposed and investigated experimentally. This paper reviews research on these complex control problems with an emphasis upon solutions which have been demon-strated to work in the laboratory and hold promise...

  13. Development of a biotechnological process for the production of high quality linen fibers.

    Science.gov (United States)

    Valladares Juárez, Ana Gabriela; Rost, Gernot; Heitmann, Uwe; Heger, Egon; Müller, Rudolf

    2011-10-01

    A novel biotechnological process for the production of high-quality flax fibers was developed. In this process, decorticated fibers from green flax were washed with 0.5% soda solution and treated with the pectinolytic strain Geobacillus thermoglucosidasius PB94A. Before drying the fibers, they were treated with the textile softener Adulcinol BUN. If the fibers contained contaminant shives, a bleaching step with hydrogen peroxide was performed before the softener treatment. In experiments where fibers were treated by the new process, and in which the bacterial solutions were reused seven times, the fiber quality was similar in all batches. The resolution of the treated fibers was 2.7 ± 0.4 and the fineness was 11.1 ± 1.1 dtex, while the starting material had a resolution of 7.3 and a fineness of 37 dtex. The new biotechnological treatment eliminates the weather-associated risks of the traditional fiber retting completely and produces consistently high-quality fibers that can be used to produce fine linen yarns.

  14. Nitrification in moving bed and fixed bed biofilters treating effluent water from a large commercial outdoor rainbow trout RAS

    DEFF Research Database (Denmark)

    Suhr, Karin; Pedersen, Per Bovbjerg

    2010-01-01

    The nitrification performance of two fixed bed (FB) biofilters and two moving bed (MB) biofilters was evaluated. They received the same cold (8 degrees C) influent water from a commercial outdoor RAS facility producing rainbow trout (average density 32 kg m(-3)). The filters were constructed as f...

  15. Bed Rest and Immobilization: Risk Factors for Bone Loss

    Science.gov (United States)

    ... Risk Factors for Bone Loss Bed Rest and Immobilization: Risk Factors for Bone Loss Like muscle, bone ... complications of pregnancy; and those who are experiencing immobilization of some part of the body because of ...

  16. Stay Legal and Safe in Treating for Bed Bugs

    Science.gov (United States)

    Quick fix solutions may sound appealing, but they may not be legal, safe, or effective. To avoid adverse effects such as poisoning, buy EPA-registered pesticides labeled for bed bug control, and follow all label directions and precautions.

  17. Patterns of granular convection and separation in narrow vibration bed

    Science.gov (United States)

    Liu, Chuanping; Wu, Ping; Wang, Li; Tong, Lige; Yin, Shaowu

    2017-06-01

    Granular convection/separation of single and binary component particles are studied in a narrow vibration bed, respectively. With filling the single light particles (molecular sieve beads), the bed exhibits five different states successively by increasing the vibration frequency f from 15Hz to 70 Hz (vibration strength Γ>3), as the global convection, symmetrical heap, unsymmetrical heap, local convection and pseudo solid. Comparatively, the granular bed of the single heavy particles (steel beads) is only in pseudo solid state at the above vibration condition. By filling binary component particles (molecular sieve and same size steel beads) instead of the single component, the bed shows similar convection state with that of the single molecular sieve beads, and the heavy steel beads are aggregated in the centre of convention roll as a core. Varying the initial distribution of binary component particles, the final convection and separation are not influenced, although the aggregation process of steel beads changes.

  18. Advanced sorbent development progam; development of sorbents for moving-bed and fluidized-bed applications

    International Nuclear Information System (INIS)

    Ayala, R.E.; Venkataramani, V.S.

    1998-01-01

    The integrated gasification combined cycle (IGCC) power system using high-temperature coal gas cleanup is one of the most promising advanced technologies for the production of electric power from coal in an environmentally acceptable manner. Unlike conventional low-temperature cleanup systems that require costly heat exchangers, high-temperature coal gas cleanup systems can be operated near 482-538 C (900-1000F) or higher, conditions that are a closer match with the gasifier and turbine components in the IGCC system, thus resulting is a more efficient overall system. GE is developing a moving-bed, high-temperature desulfurization system for the IGCC power cycle in which zinc-based regenerable sorbents are currently being used as desulfurization sorbents. Zinc titanate and other proprietary zinc-based oxides are being considered as sorbents for use in the Clean Coal Technology Demonstration Program at Tampa Electric Co.s (TECo) Polk Power Station. Under cold startup conditions at TECo, desulfurization and regeneration may be carried out at temperatures as low as 343 C (650 F), hence a versatile sorbent is desirable to perform over this wide temperature range. A key to success in the development of high-temperature desulfurization systems is the matching of sorbent properties for the selected process operating conditions, namely, sustainable desulfurization kinetics, high sulfur capacity, and mechanical durability over multiple cycles. Additionally, the sulfur species produced during regeneration of the sorbent must be in a form compatible with sulfur recovery systems, such as sulfuric acid or elemental sulfur processes. The overall objective of this program is to develop regenerable sorbents for hydrogen sulfide removal from coal-derived fuel gases in the temperature range 343-538 C (650-1000 F). Two categories of reactor configurations are being considered: moving-bed reactors and fluidized-bed (bubbling and circulating) reactors. In addition, a cost assessment and

  19. ADVANCED SORBENT DEVELOPMENT PROGRAM DEVELOPMENT OF SORBENTS FOR MOVING-BED AND FLUIDIZED-BED APPLICATIONS

    Energy Technology Data Exchange (ETDEWEB)

    R.E Ayala; V.S. Venkataramani; Javad Abbasian; Rachid B. Slimane; Brett E. Williams; Minoo K. Zarnegar; James R. Wangerow; Andy H. Hill

    2000-03-31

    The integrated gasification combined cycle (IGCC) power system using high-temperature coal gas cleanup is one of the most promising advanced technologies for the production of electric power from coal in an environmentally acceptable manner. Unlike conventional low-temperature cleanup systems that require costly heat exchangers, high-temperature coal gas cleanup systems can be operated near 482-538 C (900-1000 F) or higher, conditions that are a closer match with the gasifier and turbine components in the IGCC system, thus resulting is a more efficient overall system. GE is developing a moving-bed, high-temperature desulfurization system for the IGCC power cycle in which zinc-based regenerable sorbents are currently being used as desulfurization sorbents. Zinc titanate and other proprietary zinc-based oxides are being considered as sorbents for use in the Clean Coal Technology Demonstration Program at Tampa Electric Co.'s (TECo) Polk Power Station. Under cold startup conditions at TECo, desulfurization and regeneration may be carried out at temperatures as low as 343 C (650 F), hence a versatile sorbent is desirable to perform over this wide temperature range. A key to success in the development of high-temperature desulfurization systems is the matching of sorbent properties for the selected process operating conditions, namely, sustainable desulfurization kinetics, high sulfur capacity, and mechanical durability over multiple cycles. Additionally, the sulfur species produced during regeneration of the sorbent must be in a form compatible with sulfur recovery systems, such as sulfuric acid or elemental sulfur processes. The overall objective of this program is to develop regenerable sorbents for hydrogen sulfide removal from coal-derived fuel gases in the temperature range 343-538 C (650-1000 F). Two categories of reactor configurations are being considered: moving-bed reactors and fluidized-bed (bubbling and circulating) reactors. In addition, a cost

  20. Fluidized Bed Sputtering for Particle and Powder Metallization

    Science.gov (United States)

    2013-04-01

    Sathiyamoorthy provides a review of plasma technology used with fluidized bed techniques (13). Borer and von Rohr integrated a microwave plasma source...Plasma Spouted/Fluidized Bed for Materials Processing. Journal of Physics: Conference Series 2010, 208 (1), 012120. 14. Borer, B.; von Rohr , R...Technology 2005, 200, 377–381. 15. Morstein, M.; Karches, M.; Bayer, C.; Casanova, D.; von Rohr , P. R. Plasma CVD of Ultrathin TiO2 Films on Powders in a

  1. Pyrolysis reactor and fluidized bed combustion chamber

    Science.gov (United States)

    Green, Norman W.

    1981-01-06

    A solid carbonaceous material is pyrolyzed in a descending flow pyrolysis reactor in the presence of a particulate source of heat to yield a particulate carbon containing solid residue. The particulate source of heat is obtained by educting with a gaseous source of oxygen the particulate carbon containing solid residue from a fluidized bed into a first combustion zone coupled to a second combustion zone. A source of oxygen is introduced into the second combustion zone to oxidize carbon monoxide formed in the first combustion zone to heat the solid residue to the temperature of the particulate source of heat.

  2. Textiles wastewater treatment using anoxic filter bed and biological wriggle bed-ozone biological aerated filter.

    Science.gov (United States)

    Fu, Zhimin; Zhang, Yugao; Wang, Xiaojun

    2011-02-01

    In this study, the performance of the anoxic filter bed and biological wriggle bed-ozone biological aerated filter (AFB-BWB-O(3)-BAF) process treating real textile dyeing wastewater was investigated. After more than 2 month process operation, the average effluent COD concentration of the AFB, BWB, O(3)-BAF were 704.8 mg/L, 294.6 mg/L and 128.8 mg/L, with HRT being 8.1-7.7h, 9.2h and 5.45 h, respectively. Results showed that the effluent COD concentration of the AFB decreased with new carriers added and the average removal COD efficiency was 20.2%. During operation conditions, HRT of the BWB and O(3)-BAF was increased, resulting in a decrease in the effluent COD concentration. However, on increasing the HRT, the COD reduction capability expressed by the unit carrier COD removal loading of the BWB reactor increased, while that of the O(3)-BAF reactor decreased. This study is a beneficial attempt to utilize the AFB-BWB-O(3)-BAF combine process for textile wastewater treatment. Copyright © 2010 Elsevier Ltd. All rights reserved.

  3. More about... renal and urology

    African Journals Online (AJOL)

    in syncope and a decrease in memory/ increase in dementia. Life expectancy varies between 8.9 and 24 ... Contain the smell. • Absorb small amounts of urine. Protective linen. Protective linen includes absorbent linen savers and washable mattress protectors. Urinary catheters. • Urinary catheters should be considered.

  4. Physiological and Functional Alterations after Spaceflight and Bed Rest.

    Science.gov (United States)

    Mulavara, Ajitkumar P; Peters, Brian T; Miller, Chris A; Kofman, Igor S; Reschke, Millard F; Taylor, Laura C; Lawrence, Emily L; Wood, Scott J; Laurie, Steven S; Lee, Stuart M C; Buxton, Roxanne E; May-Phillips, Tiffany R; Stenger, Michael B; Ploutz-Snyder, Lori L; Ryder, Jeffrey W; Feiveson, Alan H; Bloomberg, Jacob J

    2018-04-03

    Exposure to microgravity causes alterations in multiple physiological systems, potentially impacting the ability of astronauts to perform critical mission tasks. The goal of this study was to determine the effects of spaceflight on functional task performance and to identify the key physiological factors contributing to their deficits. A test battery comprised of 7 functional tests and 15 physiological measures was used to investigate the sensorimotor, cardiovascular and neuromuscular adaptations to spaceflight. Astronauts were tested before and after 6-month spaceflights. Subjects were also tested before and after 70 days of 6° head-down bed rest, a spaceflight analog, to examine the role of axial body unloading on the spaceflight results. These subjects included Control and Exercise groups to examine the effects of exercise during bed rest. Spaceflight subjects showed the greatest decrement in performance during functional tasks that required the greatest demand for dynamic control of postural equilibrium which was paralleled by similar decrements in sensorimotor tests that assessed postural and dynamic gait control. Other changes included reduced lower limb muscle performance and increased heart rate to maintain blood pressure. Exercise performed during bed rest prevented detrimental change in neuromuscular and cardiovascular function, however, both bed rest groups experienced functional and balance deficits similar to spaceflight subjects. Bed rest data indicates that body support unloading experienced during spaceflight contributes to postflight postural control dysfunction. Further, the bed rest results in the Exercise group of subjects confirm that resistance and aerobic exercises performed during spaceflight can play an integral role in maintaining neuromuscular and cardiovascular function, which can help in reducing decrements in functional performance. These results indicate that a countermeasure to mitigate postflight postural control dysfunction is

  5. What Bed Size Does a Patient Need? The Relationship Between Body Mass Index and Space Required to Turn in Bed

    OpenAIRE

    Wiggermann, Neal; Smith, Kathryn; Kumpar, Dee

    2017-01-01

    Background A bed that is too small to allow patients to turn from supine to side lying increases the difficulty of mobilizing patients, which can increase risk of musculoskeletal injury to caregivers, increase risk of pressure injuries to patients, and reduce patient comfort. Currently, no guidance is available for what patient sizes are accommodated by the standard 91cm (36 in.)-wide hospital bed, and no studies have evaluated the relationship between anthropometric attributes and space requ...

  6. Partitioning and analyzing temporal variability of wash and bed ...

    Indian Academy of Sciences (India)

    In this study, 24 samples of suspended load, bed load and channel material were taken bi-weekly for a period of one year from the Kojour River of the Educational and Research Forest Watershed of Tarbiat Modares University in Iran. The suspended sediment concentration and particle-size distribution were determined.

  7. The Relationship between Parent-Infant Bed Sharing and Marital Satisfaction for Mothers of Infants

    Science.gov (United States)

    Messmer, Rosemary; Miller, Lynn D.; Yu, Christine M.

    2012-01-01

    This study investigated the relationship between marital satisfaction and time spent bed sharing with infants in a community sample of 81 bed sharing mothers. Time spent bed sharing did not significantly predict variance in marital satisfaction when considering bed sharers as a whole. Moderation analysis, however, showed the interaction between…

  8. Bed rest and increased diuretic treatment in chronic congestive heart failure

    DEFF Research Database (Denmark)

    Abildgaard, U; Aldershvile, J; Ring-Larsen, H

    1985-01-01

    To elucidate the effect of bed rest used as an adjunct to increased diuretic treatment, twelve patients with chronic congestive heart failure (CHF) had a 50% increase in loop diuretic dosage and were allocated to either continuous bed rest or bed rest during nights only. The 24-hour bed rest group...... is a reasonable adjunct to diuretic treatment in patients with CHF....

  9. Eelgrass beds and bare substrata – sparid and mugilid composition ...

    African Journals Online (AJOL)

    The results indicate that the family Mugilidae is better represented at unvegetated sites when compared to members of the family Sparidae, with the exception of Lithognathus lithognathus, but that the dominant three sparids and dominant two mugilids were most abundant in sparse eelgrass beds that included both bare ...

  10. Partitioning and analyzing temporal variability of wash and bed ...

    Indian Academy of Sciences (India)

    leads to reduction in storage capacity of dams, increases flood risk, deteriorates water quality and ultimately results .... results showed that the capacity of bed material load transport was controlled by hydraulic conditions ... oped mainly for livestock grazing in uplands. Land covers comprise Fagus orientalis, Alnus sp., Acer.

  11. Coal hydrogenation and deashing in ebullated bed catalytic reactor

    Science.gov (United States)

    Huibers, Derk T. A.; Johanson, Edwin S.

    1983-01-01

    An improved process for hydrogenation of coal containing ash with agglomeration and removal of ash from an ebullated bed catalytic reactor to produce deashed hydrocarbon liquid and gas products. In the process, a flowable coal-oil slurry is reacted with hydrogen in an ebullated catalyst bed reaction zone at elevated temperature and pressure conditions. The upward velocity and viscosity of the reactor liquid are controlled so that a substantial portion of the ash released from the coal is agglomerated to form larger particles in the upper portion of the reactor above the catalyst bed, from which the agglomerated ash is separately withdrawn along with adhering reaction zone liquid. The resulting hydrogenated hydrocarbon effluent material product is phase separated to remove vapor fractions, after which any ash remaining in the liquid fraction can be removed to produce substantially ash-free coal-derived liquid products.

  12. Thyroid and adrenal cortical rhythmicity during bed rest.

    Science.gov (United States)

    Vernikos-Danellis, J.; Leach, C. S.; Winget, C. M.; Rambaut, P. C.; Mack, P. B.

    1972-01-01

    The effects of prolonged bed rest on adrenocortical and thyroid function were assessed in eight healthy males, aged 20-40 years, who were submitted to bed rest for 56 days on a 14L:10D regimen (lights-on, 9:00 AM). Four of these subjects exercised three times daily throughout the experiment. Circulating cortisol, triiodothyronine, and thyroxine, concentrations were determined in blood samples drawn at four hourly intervals for 48-hr periods before, 10, 20, 30, 42, and 54 days during, and 10 days post-bed rest. Significant fluctuations in the circulating levels of all three hormones occurred with peaks at 7:30 AM. The suggestion is advanced that thyroid rhythms may be posture dependent.

  13. Atmospheric fluidized bed coal combustion research, development and application

    CERN Document Server

    Valk, M

    1994-01-01

    The use of fluidized bed coal combustion technology has been developed in the past decade in The Netherlands with a view to expanding the industrial use of coal as an energy supply. Various research groups from universities, institutes for applied science and from boiler industries participated and contributed to this research area. Comprehensive results of such recent experimentation and development work on atmospheric fluidized bed combustion of coal are covered in this volume. Each chapter, written by an expert, treats one specific subject and gives both the theoretical background as well a

  14. Effects of Bed Forms and Large Protruding Grains on Near-Bed Flow Hydraulics in Low Relative Submergence Conditions

    Science.gov (United States)

    Monsalve, Angel; Yager, Elowyn M.; Schmeeckle, Mark W.

    2017-10-01

    In mountain rivers, bed forms, large relatively immobile grains, and bed texture and topographic variability can significantly alter local and reach-averaged flow characteristics. The low relative submergence of large immobile grains causes highly three-dimensional flow fields that may not be represented by traditional shear stress, flow velocity, and turbulence intensity equations. To explore the influence of large protruding grains and bed forms on flow properties, we conducted a set of experiments in which we varied the relative submergence while holding the sediment transport capacity and upstream sediment supply constant. Flow and bed measurements were conducted at the beginning and end of each experiment to account for the absence or presence of bed forms, respectively. Detailed information on the flow was obtained by combining our measurements with a 3-D numerical model. Commonly used velocity profile equations only performed well at the reach scale when shallow flow effects and the roughness length of the relatively mobile sediment were considered. However, at the local scale large deviations from these profiles were observed and simple methods to estimate the spatial distribution of near-bed shear stresses are likely to be inaccurate. Zones of high turbulent kinetic energy occurred near the water surface and were largely controlled by the immobile grains and plunging flow. The reach-averaged shear stress did not correlate to depth or slope, as commonly assumed, but instead was controlled by the relative boulder submergence and degree of plunging flow. For accurate flow predictions in mountain rivers, the effects of bed forms and large boulders must be considered.

  15. Nonlinear dynamics and control of a recycle fixed bed reactor

    DEFF Research Database (Denmark)

    Recke, Bodil; Jørgensen, Sten Bay

    1997-01-01

    The purpose of this paper is twofold. Primarily to describe the dynamic behaviour that can be observed in a fixed bed reactor with recycle of unconverted reactant. Secondly to describe the possibilities of model reduction in order to facilitate control design. Reactant recycle has been shown...... to introduce periodic solution to the fixed bed reactor, a phenomenon which is not seen for the system without the recycle, at least not within the Peclet number range investigated in the present work. The possibility of model reduction by the methods of modal decomposition, and by characteristics...

  16. Alternatives for metal hydride storage bed heating and cooling

    International Nuclear Information System (INIS)

    Fisher, I.A.; Ramirez, F.B.; Koonce, J.E.; Ward, D.E.; Heung, L.K.; Weimer, M.; Berkebile, W.; French, S.T.

    1991-01-01

    The reaction of hydrogen isotopes with the storage bed hydride material is exothermic during absorption and endothermic during desorption. Therefore, storage bed operation requires a cooling system to remove heat during absorption, and a heating system to add the heat needed for desorption. Three storage bed designs and their associated methods of heating and cooling and accountability are presented within. The first design is the current RTF (Replacement Tritium Facility) nitrogen heating and cooling system. The second design uses natural convection cooling with ambient glove box nitrogen and electrical resistance for heating. This design is referred to as the Naturally Cooled/Electrically Heated (NCEH) design. The third design uses forced convection cooling with ambient glove box nitrogen and electrical resistance for heating. The design is referred to as the Forced Convection Cooled/Electrically Heated (FCCEH) design. In this report the operation, storage bed design, and equipment required for heating, cooling, and accountability of each design are described. The advantages and disadvantages of each design are listed and discussed. Based on the information presented within, it is recommended that the NCEH design be selected for further development

  17. Leaf transport in mimic mangrove forests and seagrass beds

    NARCIS (Netherlands)

    Gillis, L.G.; Bouma, T.J.; Kiswara, W.; Ziegler, A.D.; Herman, P.M.J.

    2014-01-01

    Mangrove forests and seagrass beds are thought to exchange particulate organic material, especially in the form of leaves. However, relatively little is known about the trapping capacity of mangrove above-ground roots and seagrass plants for leaf segments. We aimed to identify the major factors

  18. The fauna and flora of a kelp bed canopy

    African Journals Online (AJOL)

    The fauna and flora of the canopy of a kelp bed off. Oudekraal, on the Cape Peninsula, is surveyed. Four species of epiphytic algae occur in the kelp canopy, three restricted to. Ecklonia maxima and the fourth to Laminaria pal/ida. Epiphyte biomass is equivalent to 4 - 9% of host standing crop amongst E. maxima, but less ...

  19. Status and threats on seagrass beds using GIS in Vietnam

    Science.gov (United States)

    Luong, Cao Van; Thao, Nguyen Van; Komatsu, Teruhisa; Ve, Nguyen Dac; Tien, Dam Duc

    2012-10-01

    Seagrasses, marine flowering plants, are widely distributed along temperate and tropical coastlines of the world. Seagrasses have key ecological roles in coastal ecosystems and can form extensive meadows supporting high biodiversity. Till now, fourteen seagrass species belonging to four families were found in Vietnam: Halophila beccarii, H. decipiens, H. ovalis, H. minor, Thalassia hemprichii, Enhalus acoroides, Ruppia maritima, Halodule pinifolia, H. uninervis, Syringodium isoetifolium, Cymadocea rotundata, C. serrulata and Thalassodendron ciliatum. A total area of seagrass beds in Vietnam is estimated to be approximately 17000 ha by satellite images and GIS technology. In recent years, the distribution areas and densities of seagrass beds in Vietnam have been serious decreased compared with those 10-15 years ago. The decline level depended on the impacts by the natural process, the economical activities and the conservation awareness of local people. Thus, it is different at each coastal area. Generally speaking, the distribution areas and densities of seagrass beds were decreased by more than 50%. Seagrasses on tidal flats in some areas such as Quang Ninh, Hai Phong, Phu Quoc seem to be nearly lost. The distribution areas of seagrass beds in 2009 at Tam Giang-Cau Hai lagoon and Cua Dai estuary was decreased by 50-70% of those in early 1990s.

  20. Thermal enhancement cartridge heater modified (TECH Mod) tritium hydride bed development, Part 1 - Design and fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Klein, J.E.; Estochen, E.G. [Savannah River National Laboratory, Aiken, SC (United States)

    2015-03-15

    The Savannah River Site (SRS) tritium facilities have used first generation (Gen1) LaNi{sub 4.25}Al{sub 0.75} (LANA0.75) metal hydride storage beds for tritium absorption, storage, and desorption. The Gen1 design utilizes hot and cold nitrogen supplies to thermally cycle these beds. Second and third generation (Gen2 and Gen3) storage bed designs include heat conducting foam and divider plates to spatially fix the hydride within the bed. For thermal cycling, the Gen2 and Gen3 beds utilize internal electric heaters and glovebox atmosphere flow over the bed inside the bed external jacket for cooling. The currently installed Gen1 beds require replacement due to tritium aging effects on the LANA0.75 material, and cannot be replaced with Gen2 or Gen3 beds due to different designs of these beds. At the end of service life, Gen1 bed desorption efficiencies are limited by the upper temperature of hot nitrogen supply. To increase end-of-life desorption efficiency, the Gen1 bed design was modified, and a Thermal Enhancement Cartridge Heater Modified (TECH Mod) bed was developed. Internal electric cartridge heaters in the new design to improve end-of-life desorption, and also permit in-bed tritium accountability (IBA) calibration measurements to be made without the use of process tritium. Additional enhancements implemented into the TECH Mod design are also discussed. (authors)

  1. THERMAL ENHANCEMENT CARTRIDGE HEATER MODIFIED TECH MOD TRITIUM HYDRIDE BED DEVELOPMENT PART I DESIGN AND FABRICATION

    Energy Technology Data Exchange (ETDEWEB)

    Klein, J.; Estochen, E.

    2014-03-06

    The Savannah River Site (SRS) tritium facilities have used 1{sup st} generation (Gen1) LaNi{sub 4.25}Al{sub 0.75} (LANA0.75) metal hydride storage beds for tritium absorption, storage, and desorption. The Gen1 design utilizes hot and cold nitrogen supplies to thermally cycle these beds. Second and 3{sup rd} generation (Gen2 and Gen3) storage bed designs include heat conducting foam and divider plates to spatially fix the hydride within the bed. For thermal cycling, the Gen2 and Gen 3 beds utilize internal electric heaters and glovebox atmosphere flow over the bed inside the bed external jacket for cooling. The currently installed Gen1 beds require replacement due to tritium aging effects on the LANA0.75 material, and cannot be replaced with Gen2 or Gen3 beds due to different designs of these beds. At the end of service life, Gen1 bed desorption efficiencies are limited by the upper temperature of hot nitrogen supply. To increase end-of-life desorption efficiency, the Gen1 bed design was modified, and a Thermal Enhancement Cartridge Heater Modified (TECH Mod) bed was developed. Internal electric cartridge heaters in the new design to improve end-of-life desorption, and also permit in-bed tritium accountability (IBA) calibration measurements to be made without the use of process tritium. Additional enhancements implemented into the TECH Mod design are also discussed.

  2. Application of sedimentation model to uniform and segregated fluidized beds

    Energy Technology Data Exchange (ETDEWEB)

    Shippy, J.L. III; Watson, J.S.

    1990-10-24

    This paper incorporates concepts of unimodal and bimodal sedimentation to develop a model that accurately predicts bed expansion during particulate fluidization. During bed expansion a particle is considered to be fluidized not by the pure fluid, but by a slurry consisting of the pure fluid and other surrounding particles. The contributions of the other surrounding particles to the additional buoyant and drag forces are accounted for with the use of effective fluid or slurry properties, density and viscosity. As bed expansion proceeds, influences of the surrounding particles decrease; therefore, these effective properties are functions of the changing void fraction of the suspension. Furthermore, the expansion index, which empirically represents the degree to which viscous and inertial forces are present, is traditionally a function of a constant terminal Reynold's number. Because the effective fluid properties are considered to be changing as fluidization proceeds, the degree to which viscous and inertial forces also changes; therefore, the expansion index is written as a function of a local or intermediate Reynold's number. These concepts are further extended to bimodal fluidization in which small or light particles aid in the fluidization of the large or heavy particles. The results indicate that the proposed model more accurately predicts particulate bed expansion for a wider range of systems (gas -- liquid, low Reynold's number -- high Reynold's number) than other analytical or empirical models.

  3. Mixing and scale affect moving bed biofilm reactor (MBBR) performance

    NARCIS (Netherlands)

    Kamstra, Andries; Blom, Ewout; Terjesen, Bendik Fyhn

    2017-01-01

    Moving Bed Biofilm Reactors (MBBR) are used increasingly in closed systems for farming of fish. Scaling, i.e. design of units of increasing size, is an important issue in general bio-reactor design since mixing behaviour will differ between small and large scale. Research is mostly performed on

  4. Dynamics and mechanics of bed-load tracer particles

    Directory of Open Access Journals (Sweden)

    C. B. Phillips

    2014-12-01

    Full Text Available Understanding the mechanics of bed load at the flood scale is necessary to link hydrology to landscape evolution. Here we report on observations of the transport of coarse sediment tracer particles in a cobble-bedded alluvial river and a step-pool bedrock tributary, at the individual flood and multi-annual timescales. Tracer particle data for each survey are composed of measured displacement lengths for individual particles, and the number of tagged particles mobilized. For single floods we find that measured tracer particle displacement lengths are exponentially distributed; the number of mobile particles increases linearly with peak flood Shields stress, indicating partial bed load transport for all observed floods; and modal displacement distances scale linearly with excess shear velocity. These findings provide quantitative field support for a recently proposed modeling framework based on momentum conservation at the grain scale. Tracer displacement is weakly negatively correlated with particle size at the individual flood scale; however cumulative travel distance begins to show a stronger inverse relation to grain size when measured over many transport events. The observed spatial sorting of tracers approaches that of the river bed, and is consistent with size-selective deposition models and laboratory experiments. Tracer displacement data for the bedrock and alluvial channels collapse onto a single curve – despite more than an order of magnitude difference in channel slope – when variations of critical Shields stress and flow resistance between the two are accounted for. Results show how bed load dynamics may be predicted from a record of river stage, providing a direct link between climate and sediment transport.

  5. Exercise thermoregulation with bed rest, confinement, and immersion deconditioning

    Science.gov (United States)

    Greenleaf, J. E.

    1997-01-01

    Altered thermoregulation following exposure to prolonged (12-14 days) of bed rest and 6 hr of head-down thermoneutral water immersion in humans, and cage confinement (8 weeks) in male, mongrel dogs resulted in occasional increased core temperature (Tcore) at rest, but consistent "excessive" increase in Tcore during submaximal exercise. This excessive increase in Tcore in nonexercising and exercising subjects was independent of the mode (isometric or isotonic) of exercise training during bed rest, and was associated with the consistent hypovolemia in men but not in women taking estrogen supplementation (1.25 mg premarin/ day) which restored plasma volume during bed rest to ambulatory control levels. Post-bed rest exercise sweating (evaporative heat loss) was unchanged or higher than control levels; however, calculated tissue heat conductance was significantly lower in men, and forearm venoconstriction was greater (venous volume was reduced) in women during exercise after bed rest. Because sweating appeared proportional to the increased level of Tcore, these findings suggest that one major factor for the excessive hyperthermia is decreased core to periphery heat conduction. Exercising dogs respond like humans with excessive increase in both rectal (Tre) and exercising muscle temperatures (Tmu) after confinement and, after eight weeks of exercise training on a treadmill following confinement, they had an attenuated rate of increase of Tre even below ambulatory control levels. Intravenous infusion of glucose also attenuated not only the rise in Tre during exercise in normal dogs, but also the excessive rise in Tre and exercising Tmu after confinement. Oral glucose also appeared to reduce the rate of increase in excessive Tre in men after immersion deconditioning. There was a greater rate of rise in Tcore in two cosmonauts during supine submaximal exercise (65% VO2 max) on the fifth recovery day after the 115-day Mir 18 mission. Thus, the excessive rise in core

  6. Effectiveness of a Reduced-Risk Insecticide Based Bed Bug Management Program in Low-Income Housing

    Directory of Open Access Journals (Sweden)

    Narinderpal Singh

    2013-11-01

    Full Text Available Bed bug (Cimex lectularius L. infestations are becoming increasingly common in low-income communities. Once they are introduced, elimination is very difficult. As part of the efforts to develop effective and safe bed bug management programs, we conducted a laboratory study evaluating the efficacy of a reduced-risk insecticide—Alpine aerosol (0.5% dinotefuran. We then conducted a field evaluation of a reduced-risk insecticide based integrated pest management (IPM program in low-income family apartments with young children. In laboratory evaluations, direct spray and 5 min exposure to dry Alpine aerosol residue caused 100.0 ± 0.0 and 91.7 ± 8.3% mortality to bed bug nymphs, respectively. Direct Alpine aerosol spray killed 91.3 ± 4.3% of the eggs. The IPM program included education, steam, bagging infested linens, placing intercepting devices under furniture legs and corners of rooms, applying Alpine aerosol and Alpine dust (0.25% dinotefuran, 95% diatomaceous earth dust, and regularly scheduled monitoring and re-treatment. Nine apartments ranging from 1–1,428 (median: 29 bed bugs based on visual inspection and Climbup interceptor counts were included. Over a 6-month period, an average 172 g insecticide (Alpine aerosol + Alpine dust was used in each apartment, a 96% reduction in pesticide usage compared to chemical only treatment reported in a similar environment. The IPM program resulted in an average of 96.8 ± 2.2% reduction in the number of bed bugs. However, elimination of bed bugs was only achieved in three lightly infested apartments (<30 bed bugs at the beginning. Elimination success was closely correlated with the level of bed bug populations.

  7. Investigation of debris bed formation, spreading and coolability

    International Nuclear Information System (INIS)

    Kudinov, P.; Konovalenko, A.; Grishchenko, D.; Yakush, S.; Basso, S.; Lubchenko, N.; Karbojian, A.

    2013-08-01

    The work is motivated by the severe accident management strategy adopted in Nordic type BWRs. It is assumed that core melt ejected from the vessel will fragment, quench and form a coolable debris bed in a deep water pool below the vessel. In this work we consider phenomena relevant to the debris bed formation and coolability. Several DEFOR-A (Debris Bed Formation - Agglomeration) tests have been carried out with new corium melt material and a melt releasing nozzle mockup. The influence of the melt material, melt superheat, jet free fall height on the (i) faction of agglomerated debris, (ii) particle size distribution, (iii) ablation/plugging of the nozzle mockup has been addressed. Results of the DECOSIM (Debris Coolability Simulator) code validation against available COOLOCE data are presented in the report. The dependence of DHF on system pressure from COOLOCE experiments can be reproduced quite accurately if either the effective particle diameter or debris bed porosity is increased. For a cylindrical debris bed, good agreement is achieved in DECOSIM simulations for the particle diameter 0.89 mm and porosity 0.4. The results obtained are consistent with MEWA simulation where larger particle diameters and porosities were found to be necessary to reproduce the experimental data on DHF. It is instructive to note that results of DHF prediction are in better agreement with POMECO-HT data obtained for the same particles. It is concluded that further clarification of the discrepancies between different experiments and model predictions. In total 13 exploratory tests were carried out in PDS (particulate debris spreading) facility to clarify potential influence of the COOLOCE (VTT) facility heaters and TCs on particle self-leveling process. Results of the preliminary analysis suggest that there is no significant influence of the pins on self-leveling, at least for the air superficial velocities ranging from 0.17 up to 0.52 m/s. Further confirmatory tests might be needed

  8. Investigation of debris bed formation, spreading and coolability

    Energy Technology Data Exchange (ETDEWEB)

    Kudinov, P.; Konovalenko, A.; Grishchenko, D.; Yakush, S.; Basso, S.; Lubchenko, N.; Karbojian, A. [Royal Institute of Technology, KTH. Div. of Nuclear Power Safety, Stockholm (Sweden)

    2013-08-15

    The work is motivated by the severe accident management strategy adopted in Nordic type BWRs. It is assumed that core melt ejected from the vessel will fragment, quench and form a coolable debris bed in a deep water pool below the vessel. In this work we consider phenomena relevant to the debris bed formation and coolability. Several DEFOR-A (Debris Bed Formation - Agglomeration) tests have been carried out with new corium melt material and a melt releasing nozzle mockup. The influence of the melt material, melt superheat, jet free fall height on the (i) faction of agglomerated debris, (ii) particle size distribution, (iii) ablation/plugging of the nozzle mockup has been addressed. Results of the DECOSIM (Debris Coolability Simulator) code validation against available COOLOCE data are presented in the report. The dependence of DHF on system pressure from COOLOCE experiments can be reproduced quite accurately if either the effective particle diameter or debris bed porosity is increased. For a cylindrical debris bed, good agreement is achieved in DECOSIM simulations for the particle diameter 0.89 mm and porosity 0.4. The results obtained are consistent with MEWA simulation where larger particle diameters and porosities were found to be necessary to reproduce the experimental data on DHF. It is instructive to note that results of DHF prediction are in better agreement with POMECO-HT data obtained for the same particles. It is concluded that further clarification of the discrepancies between different experiments and model predictions. In total 13 exploratory tests were carried out in PDS (particulate debris spreading) facility to clarify potential influence of the COOLOCE (VTT) facility heaters and TCs on particle self-leveling process. Results of the preliminary analysis suggest that there is no significant influence of the pins on self-leveling, at least for the air superficial velocities ranging from 0.17 up to 0.52 m/s. Further confirmatory tests might be needed

  9. Bed agglomeration in fluidized combustor fueled by wood and rice straw blends

    DEFF Research Database (Denmark)

    Thy, Peter; Jenkins, Brian; Williams, R.B.

    2010-01-01

    Abstract Petrographic techniques have been used to examine bed materials from fluidized bed combustion experiments that utilized wood and rice straw fuel blends. The experiments were conducted using a laboratory-scale combustor with mullite sand beds, firing temperatures of 840 to 1030 °C, and run...... areas between bed particles, ultimately led to bed agglomeration. The interfaces and the presence of gas bubbles in the cement suggest a bonding material with a high surface tension and a liquid state. The cement films originate by filling of irregularities on individual and partially agglomerated bed...

  10. Exploring Parental Bonding in BED and Non-BED Obesity Compared with Healthy Controls: Clinical, Personality and Psychopathology Correlates.

    Science.gov (United States)

    Amianto, Federico; Ercole, Roberta; Abbate Daga, Giovanni; Fassino, Secondo

    2016-05-01

    Early inadequate attachment experiences are relevant co-factors in the development of obesity and Binge Eating Disorder (BED), which often concurs with obesity. The relationship of parental bonding with personality and psychopathology may influence treatment strategies for obese subjects, either affected or not with BED. In this study, 443 obese women (BMI ≥ 30 kg/m(2)), including 243 with and 200 without BED, and 158 female controls were assessed with regards to attachment, personality and eating psychopathology measures. Clusters obtained using the scores of the Parental Bonding Instrument (PBI) were compared with each other and with a control subjects' group. Lower scores of parental bonding distinguished obese subjects with respect to healthy controls. The cluster analysis revealed two clusters of parenting among obese subjects. The larger one displayed intermediate care and overprotection between controls and the smaller cluster, with the exception of paternal overprotection which is similar to controls. This larger cluster was characterized by low persistence and levels of psychopathology which are intermediate between healthy controls and the smaller cluster. The smaller cluster displayed lower care and higher overcontrol from both parents. It also displays more extreme personality traits (high novelty seeking and harm avoidance, and lower self-directedness and cooperativeness) and more severe eating and general psychopathology. Different parenting dynamics relate to different personality patterns and eating psychopathology of obese subjects, but not to binge eating conducts. Personality differences between parenting clusters are more extensive than those between BED and non-BED subgroups. The two different typologies of obese subjects based on parenting may be relevant for treatment personalization. Copyright © 2015 John Wiley & Sons, Ltd and Eating Disorders Association.

  11. What Bed Size Does a Patient Need? The Relationship Between Body Mass Index and Space Required to Turn in Bed.

    Science.gov (United States)

    Wiggermann, Neal; Smith, Kathryn; Kumpar, Dee

    A bed that is too small to allow patients to turn from supine to side lying increases the difficulty of mobilizing patients, which can increase risk of musculoskeletal injury to caregivers, increase risk of pressure injuries to patients, and reduce patient comfort. Currently, no guidance is available for what patient sizes are accommodated by the standard 91cm (36 in.)-wide hospital bed, and no studies have evaluated the relationship between anthropometric attributes and space required to turn in bed. The purpose of this research was to determine how much space individuals occupy when turning from supine to side lying as predicted by their anthropometry (i.e., body dimensions) to establish guidance on selecting the appropriate bed size. Forty-seven adult participants (24 female) with body mass index (BMI) from 20 to 76 kg/m participated in a laboratory study. Body dimensions were measured, and the envelope of space required to turn was determined using motion capture. Linear regressions estimated the relationship between anthropometric attributes and space occupied when turning. BMI was strongly correlated (R = .88) with the space required to turn. Based on the linear regressions, individuals with BMI up to 35 kg/m could turn left and right within 91 cm and individuals with BMI up to 45 kg/m could turn one direction within 91 cm. BMI is a good predictor of the space required to turn from supine to lateral. Nurses should consider placing patients that are unable to laterally reposition themselves on a wider bed when BMI is greater than 35 kg/m and should consider placing all patients greater than 45 kg/m on a wider bed regardless of mobility. Hospital administrators can use historical demographic information about the BMI of their patient populations to plan facility-level equipment procurement for equipment that accommodates their patients.

  12. Comparison of the mesophilic and thermophilic anaerobic digestion of spent cow bedding in leach-bed reactors.

    Science.gov (United States)

    Riggio, S; Hernandéz-Shek, M A; Torrijos, M; Vives, G; Esposito, G; van Hullebusch, E D; Steyer, J P; Escudié, R

    2017-06-01

    Anaerobic digestion of spent cow bedding in batch leach-bed reactors (LBRs) was compared in mesophilic and thermophilic conditions for the first time. Results show that the use of thermophilic conditions enhanced only the degradation kinetics of easily-degradable matter during the first days of the digestion, whereas similar methane yields (80% of the Biomethane Potential) were reached after 42days at both temperatures. Therefore, the anaerobic digestion in LBRs of spent cow bedding, a substrate rich in slowly-degradable compounds, was not improved in term of methane production considering the overall digestion time. Moreover, the high initial biogas production rate in thermophilic reactors was found to significantly reduce the energetic performance of the cogeneration unit at industrial scale, leading to a 5.9% decrease in the annual electricity production when compared to a mesophilic one. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Bed topography and sand transport responses to a step change in discharge and water depth

    Science.gov (United States)

    Ephemeral streams with sand and gravel beds may inherit bed topography caused by previous flow events, resulting in bed topography that is not in equilibrium with flow conditions, complicating the modeling of flow and sediment transport. Major flow events, resulting from rainfall with high intensity...

  14. Temperature and pressure distributions in a 400 kW{sub t} fluidized bed straw gasifier

    Energy Technology Data Exchange (ETDEWEB)

    Erguedenler, A.; Ghaly, A.E.; Hamdullahpur, F. [Technical Univ. of Nova Scotia, Halifax (Canada)

    1993-12-31

    The temperature and pressure distribution characteristics of a 400 kW (thermal) dual-distributor type fluidized bed straw gasifier were investigated. The effects of the bed height, equivalence ratio (actual air-fuel ratio:stoichiometric air-fuel ratio) and fluidization velocity on the temperature and pressure variations in the gasifier were studied. Generally, the bed temperature reached the steady state condition within 15--20 minutes. The average temperature of the dense bed ranged from 649{degrees}C to 875{degrees}C depending on the levels of operating parameters used. The bed temperature increased linearly with increases in the equivalence ratio, higher bed temperatures were observed with lower bed height and no clear trend for the bed temperature with respect to variations in fluidization velocity was observed. The bed height, equivalence ratio and fluidization velocity affected the pressure drop in the fluidized bed gasifier. Increasing the fluidization velocity and/or decreasing the equivalence ratio resulted in higher pressure drops in the dense bed and the freeboard regions whereas increasing the bed height increased the pressure drop only in the dense bed.

  15. Sand Bed Morphodynamics under Standing Waves and Vegetated Conditions

    Science.gov (United States)

    Landry, B. J.; Garcia, M. H.

    2010-12-01

    Littoral processes such as sediment transport, wave attenuation, and boundary layer development are governed by the presence of bathymetric features, which include large-scale sand bars upon which smaller-scale sand ripples are superimposed, as well as the presence of submarine vegetation. Numerous studies on sand ripples and bars have aided to elucidate the dynamics in oscillatory flows; however, the effect of vegetation on the system is less understood. Recent laboratory studies have focused on quantifying wave attenuation by emergent vegetation as a natural method to mitigate storm surges. The emergent vegetation, while promising for coastal protection, alters sediment transport rates directly by the physical presence of the plants near the bed and indirectly from reduction in near-bed shear stresses due to attenuated wave energy. The experimental work herein focuses on the area near the deeply submerged vegetated canopy limit (current work has a ratio of mean still water depth to plant height, H/h, = 7.9) to minimize the effect on the surface waves and discern the direct impact vegetation has on sand bed morphodynamics. Experiments were conducted in the large wave tank (49-m long by 1.83-m wide by 1.22-m deep) in the Ven Te Chow Hydrosystems Laboratory at the University of Illinois in which a high reflection wave forcing was used over a uniform sand bed with a 0.25-mm median sediment diameter in which staggered and uniform arrangements of idealized vegetation (i.e., 6.35-mm diameter rigid wooden cylinders) were positioned along the bed (e.g., at predetermined sand bar troughs and over an entire sand bar). The resulting bathymetric evolution from the vegetated case experiments were compared to the base case of no vegetation using two optical methods: a high-resolution laser displacement sensor for three-dimensional surveys and digitized profiles via high-definition panoramic images of the entire test section. The experimental findings illustrate the profound

  16. Investigation of flow mechanisms in conical models of fluidized beds and transfer of the results to high-temperature-coating beds. A study on the coating of nuclear fuel particles in fluidized beds

    International Nuclear Information System (INIS)

    Kalthoff, B.; Gyarmati, E.; Nickel, H.

    The different states of movement of the fluid-solid particle system as occurring in coating of nuclear particle fuel in conical fluidized beds determine the transfer of momentum, heat and mass in the fluidized bed. To know the flow characteristics, therefore, is essential for the understanding of the complex processes which take place during coating. As experimental studies in actual coaters initially were impossible due to the high temperature levels of up to 2000 0 C, information on characteristic behavior of the fluidized bed was obtained from geometrically similar model beds. Based on principles in the mechanics of similarity the fluid-solid particle system was selected. Hence, results obtained in model tests could be correlated to hot fluidized beds by means of a dimensionless characteristic number describing the fluid-solid system. A second combination of characteristic numbers allows the characterization of the three states of a fluidizing regime, i.e., spouting, bubbling, and slugging. For examining the model test results in hot beds, a measuring device was developed applicable to both cold model beds and actual fluidized bed coaters; pressure oscillations originating in the beds could be made visible by means of electronics and their frequency measured. Coating experiments with different batches and at different temperature levels rendered this frequency to decrease with increase in bed height. Thus the frequency is an important index for the momentary state of fluidization of the fluid-solid particle system. (U.S.)

  17. Comparison of bed shear under non-breaking and breaking solitary waves

    Digital Repository Service at National Institute of Oceanography (India)

    JayaKumar, S.; Baldock, T.E.

    New experimental measurements of bed shear under solitary waves and solitary bores that represent tsunamis are presented. The total bed shear stress was measured directly using a shear cell apparatus. The solitary wave characteristics were measured...

  18. Study on biomass pyrolysis and gasification in a fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    Su, X.; Wang, Z.; Cheng, C.; Tang, S.; Lu, Z.; Li, D. [Tsinghua University, Beijing (China). Thermal Engineering Department

    2000-08-01

    Experimental investigations of biomass pyrolysis and gasification were performed in a fluidized bed reactor with steam and nitrogen as fluid medium respectively. The size of the stainless steel reactor is 150mm ID and 1360mm in height. Five biomass samples including poplar sawdust, bagasse, cotton stem, eucalyptus globulus and pinus ratiata, have been tested on the facility at the temperatures ranging from 923K to 1073K. During each test run, biomass feedstock was fed into the reactor continuously for twelve minutes and without residue discharge, meanwhile seven gas samples were taken, five during the feeding process and two after the stop of feeding. The transient and accumulated gas yields were measured with a rotameter and a gas meter. The temperatures of the fluidized bed and freeboard were acquired by a system of thermocouples connected with a computer. The gas samples were analyzed on a gas chromatograph. On the basis of the experimental results, the variations of gas yield, gas composition, energy conversion efficiency and mass conversion efficiency with temperature are discussed for each biomass feedstock in both cases of steam and nitrogen fluidization. It has been revealed in this investigation that the presence of steam in the fluidized bed reactor stimulates tar cracking to form the gas species of C{sub 2}H{sub 4}and C{sub 2}H{sub 6}, etc. 8 ref., 15 figs., 6 tabs.

  19. Filter bed systems treating domestic wastewater in the Nordic countries - Performance and reuse of filter media

    DEFF Research Database (Denmark)

    Jenssen, Petter D.; Krogstad, T.; Paruch, A.M.

    2010-01-01

    Nine filter beds have been constructed in the Nordic countries, Denmark, Finland, Norway and Sweden. Filter beds consist of a septic tank followed by an aerobic pre-treatment biofilter and a subsequent saturated flow grass-covered filter. Thus, filter beds are similar to subsurface flow construct...... with phosphorus, the light-weight aggregate, Filtralite®P used in the saturated bed is a suitable phosphorus fertilizer and additionally has a liming effect. © 2010 Elsevier B.V....

  20. Possibility of removing condensate and scattered oil from gas-condensate field during bed flooding

    Energy Technology Data Exchange (ETDEWEB)

    Belkina, N.A.; Yagubov, M.S.

    1984-01-01

    The problem is set of evaluating the possible removal from the bed of scattered oil and condensate during flooding of the bed. For this purpose, an experimental study was made of the displacement by water from the porous medium of the oil and condensate saturating it. The obtained experimental results permit evaluation of the possible removal from the gas-condensate bed of scattered oil and condensate during flooding of the bed.

  1. Bed Bug Prevention, Detection and Control

    Science.gov (United States)

    Tips in this brochure include inspecting and cleaning second-hand furniture, inspection and prevention in hotel rooms, recognizing bites, integrated pest management, safe pesticide use, signs of infestation, and using mattress and box spring encasements.

  2. Nonproliferation and safeguard considerations: Pebble Bed reactor fuel cycle evaluation

    International Nuclear Information System (INIS)

    1978-09-01

    Nuclear fuel cycles were evaluated for the Pebble Bed Gas Cooled Reactor under development in the Federal Republic of Germany. The basic fuel cycle specified for the HTR-K and PNP is well qualified and will meet the requirements of these reactors. Twenty alternate fuel cycles are described, including high-conversion cycles, net-breeding cycles, and proliferation-resistant cycles. High-conversion cycles, which have a high probability of being successfully developed, promise a significant improvement in resource utilization. Proliferation-resistant cycles, also with a high probability of successful development, conpare very favorably with those for other types of reactors. Most of the advanced cycles could be adapted to first-generation pebble bed reactors with no significant modifications

  3. Laboratory study of gravel-bed cluster formation and disintegration

    Science.gov (United States)

    Heays, K. G.; Friedrich, H.; Melville, B. W.

    2014-03-01

    Increased knowledge of clusters is essential for the understanding of sediment transport behavior and the monitoring and protection of aquatic life. A physical study using graded river gravels is conducted in a laboratory environment. Using photogrammetry and painted gravels, a cluster identification tool (CIT) is developed based on image subtraction between subsequent frames, allowing identification of any stable areas and groups of particles on the bed. This is combined with digital particle tracking (DPT) to present a novel approach for monitoring the formation and disintegration of clusters. Clusters from graded gravels are formed successfully during the experimental stage, allowing investigation into the complex dynamic behavior of cluster formation and disintegration in a simulated natural environment. Various anchor stone arrangements are used in the experiments. However, only about one fifth of the potential anchor stones on the bed surface enable cluster formation. In general, clusters classified as "typical" and "heap" are most common. Inspection of temporal cluster coverage of the test-bed surface shows that the proportion of clusters present on the surface tends to grow with time. Maximum cluster surface coverage of between 5% and 34% is observed. In addition, particles entering and departing from clusters are monitored. Most commonly, particles enter from directly upstream of the cluster, however >20% of particles approach from a direction >20 deg from the streamwise direction. Approximately 35% of all particles directly upstream of a cluster bypass the cluster.

  4. COOLOCE debris bed experiments and simulations investigating the coolability of cylindrical beds with different materials and flow modes

    Energy Technology Data Exchange (ETDEWEB)

    Takasuo, E.; Kinnunen, T.; Holmstroem, S.; Lehtikuusi, T. [VTT Technical Research Centre of Finland (Finland)

    2013-07-15

    The COOLOCE experiments aim at investigating the coolability of debris beds of different geometries, flow modes and materials. A debris bed may be formed of solidified corium as a result of a severe accident in a nuclear power reactor. The COOLOCE-8 test series consisted of experiments with a top-flooded test bed with irregular gravel as the simulant material. The objective was to produce comparison data useful in estimating the effects of different particle materials and the possible effect of the test arrangement on the results. It was found that the dryout heat flux (DHF) measured for the gravel was lower compared to previous experiments with spherical beads, and somewhat lower compared to the early STYX experiments. The difference between the beads and gravel is at least partially explained by the smaller average size of the gravel particles. The COOLOCE-9 test series included scoping experiments examining the effect of subcooling of the water pool in which the debris bed is immersed. The experiments with initially subcooled pool suggest that the subcooling may increase DHF and increase coolability. The aim of the COOLOCE-10 experiments was to investigate the effect of lateral flooding on the DHF a cylindrical test bed. The top of the test cylinder and its sidewall were open to water infiltration. It was found that the DHF is increased compared to a top-flooded cylinder by more than 50%. This suggests that coolability is notably improved. 2D simulations of the top-flooded test beds have been run with the MEWA code. Prior to the simulations, the effective particle diameter for the spherical beads and the irregular gravel was estimated by single-phase pressure loss measurements performed at KTH in Sweden. Parameter variations were done for particle size and porosity used as input in the models. It was found that with the measured effective particle diameter and porosity, the simulation models predict DHF with a relatively good accuracy in the case of spherical

  5. Investigation of the particle flowpattern and segregation in tapered fluidized bed granulators

    NARCIS (Netherlands)

    Schaafsma, S. H.; Marx, T.; Hoffmann, A. C.

    The particle flowpattern and granule segregation in tapered fluidized beds have been studied using two techniques. The first technique is to fluidize beds of varying total mass and granule fractions, then defluidize them suddenly to "freeze" the composition, section the bed in layers, and determine

  6. Coevolution of bed surface patchiness and channel morphology: 2. Numerical experiments

    Science.gov (United States)

    Nelson, Peter A.; McDonald, Richard R.; Nelson, Jonathan M.; Dietrich, William E.

    2015-01-01

    In gravel bed rivers, bed topography and the bed surface grain size distribution evolve simultaneously, but it is not clear how feedbacks between topography and grain sorting affect channel morphology. In this, the second of a pair of papers examining interactions between bed topography and bed surface sorting in gravel bed rivers, we use a two-dimensional morphodynamic model to perform numerical experiments designed to explore the coevolution of both free and forced bars and bed surface patches. Model runs were carried out on a computational grid simulating a 200 m long, 2.75 m wide, straight, rectangular channel, with an initially flat bed at a slope of 0.0137. Over five numerical experiments, we varied (a) whether an obstruction was present, (b) whether the sediment was a gravel mixture or a single size, and (c) whether the bed surface grain size feeds back on the hydraulic roughness field. Experiments with channel obstructions developed a train of alternate bars that became stationary and were connected to the obstruction. Freely migrating alternate bars formed in the experiments without channel obstructions. Simulations incorporating roughness feedbacks between the bed surface and flow field produced flatter, broader, and longer bars than simulations using constant roughness or uniform sediment. Our findings suggest that patches are not simply a by-product of bed topography, but they interact with the evolving bed and influence morphologic evolution.

  7. Flow and sediment dynamics in bed discordant channel confluences

    OpenAIRE

    Blanckaert, Koen; Leite Ribeiro, Marcelo; Schleiss, Anton

    2011-01-01

    Confluences between small steep tributaries with dominant supply of poorly sorted sediment and larger main channels with dominant flow supply, which are characterized by a pronounced bed discordance, have not yet been considered in the literature. The hydro-morpho-sedimentary processes in such confluences are not well described by existing conceptual models of confluence dynamics. Examples of such confluences on the Upper Rhone River, Switzerland, served as prototype for the reported laborato...

  8. Development and Design of Sludge Freezing Beds

    Science.gov (United States)

    1988-12-01

    freezing often occurs in nature. A typical example is the desalin - ation of sea ice. Initially, brine is concentrated between ice crystal boundaries...Research, 67(3): 1085-1090. Cox, G.F.N. and W.F. Weeks (1975) Brine drainage and initial salt entrapment in sodium chloride ice. USA Cold Regions...Over a period of time, this brine drains out by gravity leaving relatively pure ice (Cox and Weeks 1975). Another example is the formation of pure ice

  9. Heat transfer in the inner and boundary region of pebble beds

    International Nuclear Information System (INIS)

    Robold, K.

    1982-07-01

    The effective thermal conductivity in the inner and boundary region of pebble beds have been measured. The experiments were carried out in evacuated pebble beds and beds with stagnant Helium (p = 700...850 mbar). The temperature range was 300 to 1900 K. The experimental results are described by new models. (orig.) [de

  10. Realization of a gamma emission tomography by a servo-controlled camera and bed

    International Nuclear Information System (INIS)

    Parmentier, M.; Gunzman, D.; Bidet, R.

    1979-01-01

    A gamma-camera and a whole-body bed were connected to a minicomputer which controlled automatically their movements. By combining horizontal displacement of the bed with vertical displacement and rotation of the camera we were able to obtain the equivalent of camera rotation around the bed. This method provides an inexpensive way of realizing gamma emission tomography [fr

  11. Bed agglomeration in fluidized combustor fueled by wood and rice straw blends

    NARCIS (Netherlands)

    Thy, P.; Jenkins, B.M.; Williams, R.B.; Lesher, C.E.; Bakker, R.R.

    2010-01-01

    Petrographic techniques have been used to examine bed materials from fluidized bed combustion experiments that utilized wood and rice straw fuel blends. The experiments were conducted using a laboratory-scale combustor with mullite sand beds, firing temperatures of 840 to 1030 °C, and run durations

  12. Intermittent hypoxia and cancer: Undesirable bed partners?

    Science.gov (United States)

    Almendros, Isaac; Gozal, David

    2017-08-14

    The deleterious effects of intermittent hypoxia (IH) on cancer biology have been primarily evaluated in the context of the aberrant circulation observed in solid tumors which results in recurrent intra-tumoral episodic hypoxia. From those studies, IH has been linked to an accelerated tumor progression, metastasis and resistance to therapies. More recently, the role of IH in cancer has also been studied in the context of obstructive sleep apnea (OSA), since IH is a hallmark characteristic of this condition. Such recent studies are undoubtedly adding more information regarding the role of IH on tumor malignancy. In terms of the IH patterns associated with OSA, this altered oxygenation paradigm has been recently proposed as a determinant factor in fostering cancer incidence and progression from both in vitro and in vivo experimental models. Here, we summarize all the available evidence to date linking IH effects on several types of cancer. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Equilibrium modeling of gasification: Gibbs free energy minimization approach and its application to spouted bed and spout-fluid bed gasifiers

    International Nuclear Information System (INIS)

    Jarungthammachote, S.; Dutta, A.

    2008-01-01

    Spouted beds have been found in many applications, one of which is gasification. In this paper, the gasification processes of conventional and modified spouted bed gasifiers were considered. The conventional spouted bed is a central jet spouted bed, while the modified spouted beds are circular split spouted bed and spout-fluid bed. The Gibbs free energy minimization method was used to predict the composition of the producer gas. The major six components, CO, CO 2 , CH 4 , H 2 O, H 2 and N 2 , were determined in the mixture of the producer gas. The results showed that the carbon conversion in the gasification process plays an important role in the model. A modified model was developed by considering the carbon conversion in the constraint equations and in the energy balance calculation. The results from the modified model showed improvements. The higher heating values (HHV) were also calculated and compared with the ones from experiments. The agreements of the calculated and experimental values of HHV, especially in the case of the circular split spouted bed and the spout-fluid bed were observed

  14. Thermo-catalytic pyrolysis of waste polyethylene bottles in a packed bed reactor with different bed materials and catalysts

    International Nuclear Information System (INIS)

    Obeid, Farah; Zeaiter, Joseph; Al-Muhtaseb, Ala’a H.; Bouhadir, Kamal

    2014-01-01

    Highlights: • Thermo-catalytic pyrolysis of waste polyethylene bottles was investigated. • The highest yield of liquid (82%) was obtained over a cement powder bed. • Acidic catalysts narrowed the carbon chain length of the paraffins to C 10 –C 28 . • Combination of cement bed with HBeta catalyst gave the highest yield of liquid. • Significant yield of aromatics was obtained mainly naphthalene and D-limonene. - Abstract: Plastic waste is an increasing economic and environmental problem as such there is a great need to process this waste and reduce its environmental impact. In this work, the pyrolysis of high density polyethylene (HDPE) waste products was investigated using both thermal and catalytic cracking techniques. The experimental work was carried out using packed bed reactor operating under an inert atmosphere at 450 °C. Different reactor bed materials, including sand, cement and white clay were used to enhance the thermal cracking of HDPE. In addition, the catalytic effect of sodium hydroxide, HUSY and HBeta zeolite catalysts on the degradation of HDPE waste was also investigated. The reactor beds were found to significantly alter the yield as well as the product composition. Products such as paraffins (⩽C 44 ), olefins (⩽C 22 ), aromatics (⩽C 14 ) and alcohols (C 16 and C 17 ) were obtained at varying rates. The highest yield of liquid (82%) was obtained over a cement powder bed with a paraffin yield of 58%. The yield of paraffins and olefins followed separate paths, for paraffins it was found to increase in the order or Cement > White clay > Silica Sand, whereas for the olefins it was in the reverse order Silica Sand > White clay > Cement. The results obtained in this work exhibited a higher P/O ratio than expected, where the amount of generated paraffins was greater than 60% in most cases. Less olefin was generated as a consequence. This indicates that the product generated is more suited to be used as a fuel rather than as a chemical

  15. Method and apparatus for enhancing the desulfurization of hot coal gas in a fluid-bed coal gasifier

    Science.gov (United States)

    Grindley, T.

    1988-04-05

    A process and apparatus for providing additional desulfurization of the hot gas produced in a fluid-bed coal gasifier, within the gasifier is described. A fluid-bed of iron oxide is located inside the gasifier above the gasification bed in a fluid-bed coal gasifier in which in-bed desulfurization by lime/limestone takes place. The product gases leave the gasification bed typically at 1600 to 1800 F and are partially quenched with water to 1000 to 1200 F before entering the iron oxide bed. The iron oxide bed provides additional desulfurization beyond that provided by the lime /limestone. 1 fig.

  16. Ammonia, Total Reduced Sulfides, and Greenhouse Gases of Pine Chip and Corn Stover Bedding Packs.

    Science.gov (United States)

    Spiehs, Mindy J; Brown-Brandl, Tami M; Parker, David B; Miller, Daniel N; Berry, Elaine D; Wells, James E

    2016-03-01

    Bedding materials may affect air quality in livestock facilities. Our objective in this study was to compare headspace concentrations of ammonia (NH), total reduced sulfides (TRS), carbon dioxide (CO), methane (CH), and nitrous oxide (NO) when pine wood chips ( spp.) and corn stover ( L.) were mixed in various ratios (0, 10, 20, 30, 40, 60, 80, and 100% pine chips) and used as bedding with manure. Air samples were collected from the headspace of laboratory-scaled bedded manure packs weekly for 42 d. Ammonia concentrations were highest for bedded packs containing 0, 10, and 20% pine chips (equivalent to 501.7, 502.3, and 502.3 mg m, respectively) in the bedding mixture and were lowest when at least 80% pine chips were used as bedding (447.3 and 431.0 mg m, respectively for 80 and 100% pine chip bedding). The highest NH concentrations were observed at Day 28. The highest concentration of TRS was observed when 100% pine chips were used as bedding (11.4 µg m), with high concentrations occurring between Days 7 and 14, and again at Day 35. Greenhouse gases were largely unaffected by bedding material but CH and CO concentrations increased as the bedded packs aged and NO concentrations were highly variable throughout the incubation. We conclude that a mixture of bedding material that contains 30 to 40% pine chips may be the ideal combination to reduce both NH and TRS emissions. All gas concentrations increased as the bedded packs aged, suggesting that frequent cleaning of facilities would improve air quality in the barn, regardless of bedding materials used. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  17. Simultaneous heat and mass transfer in packed bed brying of seeds having a mucilage coating

    Directory of Open Access Journals (Sweden)

    M. M. Prado

    2008-03-01

    Full Text Available The simultaneous heat and mass transfer between fluid phase and seeds having a mucilaginous coating was studied during packed bed drying. To describe the process, a two-phase model approach was employed, in which the effects of bed shrinkage and nonconstant physical properties were considered. The model took into account bed contraction by employing moving coordinates. Equations relating shrinkage and structural parameters of the packed bed with moisture content, required in the drying model, were developed from experimental results in thick-layer bed drying. The model verification was based on a comparison between experimental and predicted data on moisture content and temperature along the bed. Parametric studies showed that the application of correlations capable of incorporating changes in bed properties gives better data simulation. By experimental-theoretical analysis, the importance of shrinkage for a more accurate interpretation of heat and mass transfer phenomena in the drying of porous media composed of mucilaginous seeds is corroborated.

  18. Four Bed Molecular Sieve - Exploration (4BMS-X) Virtual Heater Design and Optimization

    Science.gov (United States)

    Schunk, R. Gregory; Peters, Warren T.; Thomas, John T., Jr.

    2017-01-01

    A 4BMS-X (Four Bed Molecular Sieve - Exploration) design and heater optimization study for CO2 sorbent beds in proposed exploration system architectures is presented. The primary objectives of the study are to reduce heater power and thermal gradients within the CO2 sorbent beds while minimizing channeling effects. Some of the notable changes from the ISS (International Space Station) CDRA (Carbon Dioxide Removal Assembly) to the proposed exploration system architecture include cylindrical beds, alternate sorbents and an improved heater core. Results from both 2D and 3D sorbent bed thermal models with integrated heaters are presented. The 2D sorbent bed models are used to optimize heater power and fin geometry while the 3D models address end effects in the beds for more realistic thermal gradient and heater power predictions.

  19. Modeling stationary and dynamic pebbles in a pebble bed reactor

    International Nuclear Information System (INIS)

    Zhao, Xiang; Montgomery, Trent; Zhang, Sijun

    2011-01-01

    This paper presents a numerical study of the stationary and dynamic pebbles in a pebble bed reactor (PBR) by means of discrete element method (DEM). At first, the packing structure of stationary pebbles is simulated by filling process until the settling of pebbles into PBR. The packing structural properties are obtained and analyzed. Subsequently, when the outlet of PBR is open during the operational maintenance of PBR, the stationary pebbles start to flow downward and are removed at the bottom of PBR. The dynamic behavior of pebbles is predicted and discussed. Our results indicate the DEM can offer both macroscopic and microscopic information for PBR design calculations and safety assessment. (author)

  20. The Tore Supra Lower Hybrid Test Bed : improvements and applications

    International Nuclear Information System (INIS)

    Delpech, L.; Achard, J.; Beaumont, B.

    2006-01-01

    Within the CIMES project framework in Tore Supra, a klystron TH2103C (3.7 GHz) is under development at THALES ELECTRON DEVICES. It differs from the previous klystrons used in Tore Supra generator mainly in that it has no modulating anode, the RF output power will reach 700 kW CW, by raising the High Voltage value to 76 kV and a beam current up to 23 A. The Tore Supra test bed is a dedicated facility used for high power tests on RF components or on RF transmitters. It has been improved to integrate the TH2103C klystron and a specific 100 kV solide state switch which control the beam current. Since April 2005, the integration of the first tube (without modulating anode) and the 100 kV switch has been completed in the Test Bed and has allowed the modifications and tests of the interfaces and security system for the devices. Improvements were also made on the cooling loop flow to dissipate a power of 1750 kW CW. With these devices, the RF power routinely available in the Lower Hybrid Test Bed is 400 kW CW. With the development of the TH2103C, detailed studies and tests on RF components which will be used up to 750 kW CW on match load or 700 kW on VSWR = 1.4, are necessary to evaluate their performances and thermal behaviour. The test a crucial component, the recombiner, which adds the RF powers coming from the two RF outputs of the TH2103C and inject the resulted power into one WR284 waveguide to a test load or to the plasma, was completed. Two tests have been performed : a thermal study with 400 kW during 1000 s, and RF pulsed tests on short cuts to increase the value of the electric field inside the component. The experiments and calculations (ANSYS and HFSS codes) validate the use of this device with the TH2103C. A module made with two different Beryllium Oxide RF windows, has been under test. The losses on each window are measured by calorimetric measurements and evaluated by computation with HFSS and ANSYS code. The results are compared. In this paper, the

  1. Characterisation of coal and chars in fluidised bed gasification

    CSIR Research Space (South Africa)

    Oboirien, BO

    2009-03-01

    Full Text Available gasification of high-ash Chinese coal in a pilot plant. The data also shows that the mean particle sizes of the various residual char were smaller than the feed coal and the particle size of the bed char were higher than the particle of the cyclone char... and ultimate analysis Results consisting of proximate and ultimate analyses together calorific value of the parent coals and chars are presented in Table 4. The ash content of the different coal samples ranges from 33.4- 40.4 wt %, the calorific value...

  2. Automated Design and Optimization of Pebble-bed Reactor Cores

    International Nuclear Information System (INIS)

    Gougar, Hans D.; Ougouag, Abderrafi M.; Terry, William K.

    2010-01-01

    We present a conceptual design approach for high-temperature gas-cooled reactors using recirculating pebble-bed cores. The design approach employs PEBBED, a reactor physics code specifically designed to solve for and analyze the asymptotic burnup state of pebble-bed reactors, in conjunction with a genetic algorithm to obtain a core that maximizes a fitness value that is a function of user-specified parameters. The uniqueness of the asymptotic core state and the small number of independent parameters that define it suggest that core geometry and fuel cycle can be efficiently optimized toward a specified objective. PEBBED exploits a novel representation of the distribution of pebbles that enables efficient coupling of the burnup and neutron diffusion solvers. With this method, even complex pebble recirculation schemes can be expressed in terms of a few parameters that are amenable to modern optimization techniques. With PEBBED, the user chooses the type and range of core physics parameters that represent the design space. A set of traits, each with acceptable and preferred values expressed by a simple fitness function, is used to evaluate the candidate reactor cores. The stochastic search algorithm automatically drives the generation of core parameters toward the optimal core as defined by the user. The optimized design can then be modeled and analyzed in greater detail using higher resolution and more computationally demanding tools to confirm the desired characteristics. For this study, the design of pebble-bed high temperature reactor concepts subjected to demanding physical constraints demonstrated the efficacy of the PEBBED algorithm.

  3. Product removal and solids transport from fluidized-bed calciners

    International Nuclear Information System (INIS)

    Grimmett, E.S.; Munger, D.H.

    1978-09-01

    Methods of removing the solid product from pilot-plant and production fluidized-bed calciners, and transporting product to underground storage vaults are reported here. Testing of dense-phase solids transport systems in test loops during development of a 15-cm-diam. and 30-cm-diam. calciner are described. A lean-phase solid transport system is used with the Waste Calcining Facility. The results of some recent tests done in a lean-phase transport system connected to the 30-cm-diam. calciner are included in this report

  4. The effect of bed particle size and deposit morphology on the filtration of magnetite through granular graphite beds

    International Nuclear Information System (INIS)

    Barbieri, R.R.; Bercovich, E.J.; Liberman, S.J.

    1980-01-01

    Graphite filters are of great interest for water purification in nuclear power reactors' primary systems due to their possible operation at high temperature. The influence of the bed particle size on the retention of magnetite from aqueous suspensions at room temperature was studied. The filtration coefficient changes from 0.0 to 0.18 as the mean graphite particle diameter decreases from 1.2 to 0. mm. As the retention increases, there is also an increase in the differential pressure across the bed, so both effects must be considered in order to optimize filter's operation. The specific effective volume of the deposit was calculated with the Blake-Kozeny equation and the experimental specific volumes. These are much larger than the specific volume of solid magnetite. From the results, information regarding the morphology of the deposit in the filter is obtained. (M.E.L) [es

  5. Relations between red beds times and uranic mineralization at the area of north-west China, Shaanxi and Inner Mongolia

    International Nuclear Information System (INIS)

    Zhou Qiaosheng; Quan Zhigao

    1989-04-01

    Rad beds played an important role in the uranic mineralization. After analyzing the geological evolution in North-West China, Saanxi and Inner Mongolia the red beds is divided into six periods. The evolution rules at each period are studied. The authors found that the time of uranic mineralication and formation of red beds (basin) is simultaneously, the uranic deposits and red beds are accompanying minerals in all places existing deposits. Uranic mineralization is bound up with the continental red beds which was formed under dry and hot climate, but has no relations with the marine red beds. The place where the deposits exist, the red beds must exist, conversely it is not true. In the section, a big uranic deposit is generated only under or above the red beds. The relations between red beds and rich deposit are also explored. The mineralization theory and the model of uranic mineralization in red beds times are presented

  6. Optimization Model for Capacity Management and Bed Scheduling for Hospital

    Science.gov (United States)

    Sitepu, Suryati; Mawengkang, Herman; Husein, Ismail

    2018-01-01

    Hospital is a very important institution to provide health care for people. It is not surprising that nowadays the people’s demands for hospital is increasing.. However, due to the rising cost of healthcare services, hospitals need to consider efficiencies in order to overcome these two problems. This paper deals with an integrated strategy of staff capacity management and bed allocation planning to tackle these problems. Mathematically, the strategy can be modeled as an integer linear programming problem. We solve the model using a direct neighborhood search approach, based on the notion of superbasic variables.

  7. Carbon Sequestration in Olivine and Basalt Powder Packed Beds.

    Science.gov (United States)

    Xiong, Wei; Wells, Rachel K; Giammar, Daniel E

    2017-02-21

    Fractures and pores in basalt could provide substantial pore volume and surface area of reactive minerals for carbonate mineral formation in geologic carbon sequestration. In many fractures solute transport will be limited to diffusion, and opposing chemical gradients that form as a result of concentration differences can lead to spatial distribution of silicate mineral dissolution and carbonate mineral precipitation. Glass tubes packed with grains of olivine or basalt with different grain sizes and compositions were used to explore the identity and spatial distribution of carbonate minerals that form in dead-end one-dimensional diffusion-limited zones that are connected to a larger reservoir of water in equilibrium with 100 bar CO 2 at 100 °C. Magnesite formed in experiments with olivine, and Mg- and Ca-bearing siderite formed in experiments with flood basalt. The spatial distribution of carbonates varied between powder packed beds with different powder sizes. Packed beds of basalt powder with large specific surface areas sequestered more carbon per unit basalt mass than powder with low surface area. The spatial location and extent of carbonate mineral formation can influence the overall ability of fractured basalt to sequester carbon.

  8. Low-energy collisions between electrons and BeD+

    Science.gov (United States)

    Niyonzima, S.; Pop, N.; Iacob, F.; Larson, Å; Orel, A. E.; Mezei, J. Zs; Chakrabarti, K.; Laporta, V.; Hassouni, K.; Benredjem, D.; Bultel, A.; Tennyson, J.; Reiter, D.; Schneider, I. F.

    2018-02-01

    Multichannel quantum defect theory is applied in the treatment of the dissociative recombination and vibrational excitation processes for the BeD+ ion in the 24 vibrational levels of its ground electronic state ({{X}}{}1{{{Σ }}}+,{v}{{i}}+=0\\ldots 23). Three electronic symmetries of BeD** states ({}2{{\\Pi }}, {}2{{{Σ }}}+, and {}2{{Δ }}) are considered in the calculation of cross sections and the corresponding rate coefficients. The incident electron energy range is 10‑5–2.7 eV and the electron temperature range is 100–5000 K. The vibrational dependence of these collisional processes is highlighted. The resulting data are useful in magnetic confinement fusion edge plasma modeling and spectroscopy, in devices with beryllium based main chamber materials, such as ITER and JET, and operating with the deuterium–tritium fuel mix. An extensive rate coefficients database is presented in graphical form and also by analytic fit functions whose parameters are tabulated in the supplementary material.

  9. Comparison of posterior fossa and tumor bed boost in medulloblastoma.

    Science.gov (United States)

    Paulino, A C; Saw, C B; Wen, B C

    2000-10-01

    To quantify the difference between the area of brain irradiated using the posterior fossa boost (PFB) and tumor bed boost (TBB) in medulloblastoma, we studied 15 simulation radiographs of patients treated in our institution from 1990 and 1999. The PFB was compared with the TBB, which was defined as the tumor bed plus 2-cm margin as demonstrated by postoperative magnetic resonance imaging. The PFB field treated a mean area of 9.43 cm2 more brain than the TBB. In 3 patients (20%), the area of the brain in the TBB was larger than the PFB. In 11 patients (73.3%), the PFB field had more than 10% more brain than the TBB. The cochlea was in the PFB and TBB field in all patients. In more than two thirds of patients, the area of brain irradiated with the PFB was at least 10% greater than the TBB. Future studies are needed to determine whether the TBB can replace the PFB in patients with medulloblastoma.

  10. Changes in mood status and neurotic levels during a 20-day bed rest

    Science.gov (United States)

    Ishizaki, Yuko; Ishizaki, Tatsuro; Fukuoka, Hideoki; Kim, Chang-Sun; Fujita, Masayo; Maegawa, Yuko; Fujioka, Hiroshi; Katsura, Taisaku; Suzuki, Yoji; Gunji, Atsuaki

    2002-04-01

    This study evaluated changes of mood status and depressive and neurotic levels in nine young male subjects during a 20-day 6° head-down tilting bed rest and examined whether exercise training modified these changes. Participants were asked to complete psychometrical inventories on before, during, and after the bed rest experiment. Depressive and neurotic levels were enhanced during bed rest period according to the Japanese version of Zung's Self-rating Depression Scale and the Japanese version of the General Health Questionnaire. Mood state "vigor" was impaired and "confusion" was increased during bed rest and recumbent control periods compared to pre-bed rest and ambulatory control periods according to the Japanese version of Profiles of Mood State, whereas the mood "tension-anxiety", "depression-dejection", "anger-hostility" and "fatigue" were relatively stable during experiment. Isometric exercise training did not modify these results. Microgravity, along with confinement to bed and isolation from familiar environments, induced impairment of mental status.

  11. Dynamic transition between fixed- and mobile-bed: mathematical and numerical aspects

    Science.gov (United States)

    Zugliani, Daniel; Pasqualini, Matteo; Rosatti, Giorgio

    2017-04-01

    Free-surface flows with high sediment transport (as debris flow or hyper-concentrated flow) are composed by a mixture of fluid and solid phase, usually water and sediment. When these flows propagate over loose beds, particles constituting the mixture of water and sediments strongly interact with the ones forming the bed, leading to erosion or deposition. However, there are lots of other situations when the mixture flows over rigid bedrocks or over artificially paved transects, so there is no mass exchange between bed and mixture. The two situations are usually referred to as, respectively, mobile- and fixed-bed conditions. From a mathematical point of view, the systems of Partial Differential Equations (PDEs) that describe these flows derive from mass and momentum balance of both phases, but, the two resulting PDEs systems are different. The main difference concerns the concentration: in the mobile-bed condition, the concentration is linked to the local flow conditions by means of a suitable rheological relation, while in the fixed-bed case, the concentration is an unknown of the problem. It is quite common that a free surface flow with high sediment transport, in its path, encounters both conditions. In the recent work of Rosatti & Zugliani 2015, the mathematical and numerical description of the transition between fixed- and mobile-bed was successfully resolved, for the case of low sediment transport phenomena, by the introduction of a suitable erodibility variable and satisfactory results were obtained. The main disadvantage of the approach is related to the erodibility variable, that changes in space, based on bed characteristics, but remains constant in time. However, the nature of the bed can change dynamically as result of deposition over fixed bed or high erosion over mobile bed. With this work, we extend the applicability of the mentioned approach to the more complex PDEs describing the hyper-concentrated flow. Moreover, we introduce a strategy that allows

  12. The relationship between bed size and profitability in South Carolina hospitals.

    Science.gov (United States)

    Kim, Yang K; Glover, Saundra H; Stoskopf, Carleen H; Boyd, Suzan D

    2002-01-01

    The purpose of the study is to identify factors affecting hospital profitability and to find the optimal hospital bed size that assures maximum profit. This is a cross-sectional study using survey data obtained from acute care hospitals in South Carolina in 1997. The relationship of hospital profitability and hospital bed size revealed that when bed size increases, hospital profitability increases, decreases, and then increases again. For the patient profit proportion, the turning points in bed size are 238.22 and 560.08. For the total profit proportion, the turning points in bed size are 223.31 and 503.86. The results on the relationship between bed size and hospital profitability indicate that medium-size hospitals have less profitability.

  13. Histamine as an emergent indoor contaminant: Accumulation and persistence in bed bug infested homes.

    Science.gov (United States)

    DeVries, Zachary C; Santangelo, Richard G; Barbarin, Alexis M; Schal, Coby

    2018-01-01

    Histamine is used in bronchial and dermal provocation, but it is rarely considered an environmental risk factor in allergic disease. Because bed bugs defecate large amounts of histamine as a component of their aggregation pheromone, we sought to determine if histamine accumulates in household dust in bed bug infested homes, and the effects of bed bug eradication with spatial heat on histamine levels in dust. We collected dust in homes and analyzed for histamine before, and up to three months after bed bug eradication. Histamine levels in bed bug infested homes were remarkably high (mean = 54.6±18.9 μg/100 mg of sieved household dust) and significantly higher than in control homes not infested with bed bugs (mean emergent contaminant and pose a serious health risk in the indoor environment.

  14. Effect of 14 days of bed rest on urine metabolite excretion and plasma enzyme levels

    Science.gov (United States)

    Pace, N.; Grunbaum, B. W.; Kodama, A. M.; Rahlmann, D. F.; Newsom, B. D.

    1974-01-01

    After 1 week of ambulatory base-line measurement, a group of 8 men 19-26 years of age remained continuously recumbent for 14 days. Studies were continued for 1 week following the prolonged recumbency. Urine excretion rates for a number of constituents were determined 2 days before bed rest, on day 14 of bed rest, and day 6 after bed rest. Blood plasma samples were also obtained at these times, and analyzed for several enzymes. On day 14 of bed rest significant increases were observed in urine excretion of total osmotically-active substances, magnesium, calcium, phosphate, creatinine, hydroxyproline, and 17-OH corticosteroids. A decrease occurred in urinary glucose excretion. Plasma levels of alkaline phosphatase and LDH-3 were depressed, while plasma GPT was elevated. Many of these changes persisted on day 6 after bed rest, and are interpreted as concomitants of the disuse atrophy of the musculoskeletal system that characterizes prolonged bed rest and weightlessness.

  15. Geomorphology of ice stream beds: recent progress and future challenges

    Science.gov (United States)

    Stokes, Chris R.

    2016-04-01

    Ice sheets lose mass primarily by melting and discharge via rapidly-flowing ice streams. Surface and basal melting (e.g. of ice shelves) are closely linked to atmospheric and oceanic conditions, but the mechanisms that drive changes in ice stream discharge are more complex; and are influenced by conditions at their bed which can sustain, enhance or inhibit their motion. Although explicit comparisons are rare, the ice-bed interface is similar to the 'boundary layer' in fluvial and aeolian environments, where shear stresses (both basal and lateral in the case of ice streams) oppose the flow of the overlying medium. The analogy extends further because processes within the boundary layer create a distinctive geomorphology (and roughness) that is characterised by subglacial bedforms that resemble features in fluvial and aeolian environments. Their creation results from erosion, transport and deposition of sediment which is poorly constrained, but which is intimately linked to the mechanisms through which ice streams are able to flow rapidly. The study of ice stream geomorphology is, therefore, critical to our understanding of their dynamics. Despite difficulty in observing the subglacial environment of active ice streams, our understanding of their geomorphology has grown rapidly in the last three decades, from almost complete ignorance to a detailed knowledge of their geomorphological products. This has been brought about by two main approaches: (i) geophysical investigation of modern (active) ice streams, and (ii) sedimentological and geomorphological investigation of palaeo-ice stream beds. The aim of this paper is to review progress in these two areas, highlight the key questions that remain, and discuss the opportunities that are likely to arise that will enable them to be addressed. It is clear that whilst these two main approaches have led to important advances, they have often been viewed as separate sub-disciplines, with minimal cross-pollination of ideas and

  16. Scaling of permeabilities and friction factors of homogeneously expanding gas-solids fluidized beds: Geldart’s A powders and magnetically stabilized beds

    Directory of Open Access Journals (Sweden)

    Hristov Jordan Y.

    2006-01-01

    Full Text Available The concept of a variable friction factor of fluid-driven de form able powder beds undergoing fluidization is discussed. The special problem discussed addresses the friction factor and bed permeability relationships of Geldart’s A powders and magnetically stabilized beds in axial fields. Governing equations and scaling relation ships are developed through three approaches (1 Minimization of the pressure drop with respect to the fluid velocity employing the Darcy-Forchheimer equation together with the Richardson-Zaki scaling law, (2 Minimization of the pres sure drop across an equivalent-channel replacing the actual packed beds by a straight pipe with bed-equivalent obstacle of a simple geometry, and (3 Entropy minimization method applied in cases of the Darcy-Forchheimer equation and the equivalent-channel model. Bed-to-surface heat transfer coefficients are commented in the context of the porosity/length scale relationships developed. Both the pressure drop curves developments and phase diagram de signs are illustrated by applications of the intersection of asymptotes technique to beds exhibiting certain degree of cohesion.

  17. Mounted Smartphones as Measurement and Control Platforms for Motor-Based Laboratory Test-Beds

    OpenAIRE

    Jared A. Frank; Anthony Brill; Vikram Kapila

    2016-01-01

    Laboratory education in science and engineering often entails the use of test-beds equipped with costly peripherals for sensing, acquisition, storage, processing, and control of physical behavior. However, costly peripherals are no longer necessary to obtain precise measurements and achieve stable feedback control of test-beds. With smartphones performing diverse sensing and processing tasks, this study examines the feasibility of mounting smartphones directly to test-beds to exploit their em...

  18. Sediment Resuspension and Bed Morphology in Highly Turbulent Flows

    Science.gov (United States)

    Johnson, B. A.; Cowen, E. A.

    2010-12-01

    Motivated by environmental flows where turbulence levels are set by processes other than mean shear (e.g., breaking surface and internal waves and bores) we choose to study turbulent boundary layers and sediment resuspension in the absence of mean shear using a recently-developed facility designed to generate homogeneous isotropic turbulence with low mean flows. Similar investigations have been performed with grid-stirred tanks (GSTs), though significant mean flows were found to exist in these tanks, altering the balance of fluid forces present. Significantly, we find that the interaction of turbulence with a permeable sediment boundary results in the formation of ripple patterns. Our facility uses a Randomly Actuated Synthetic Jet Array (RASJA) and allows us to control the turbulent forcing while ensuring significantly less mean flow relative to prior facilities. We performed measurements using Particle Image Velocimetry (PIV), first with a solid bottom boundary, to examine the turbulent structures and nature of the flow at the bed. We measured vertical profiles of statistical metrics such as turbulence intensity, turbulent kinetic energy, spectra, and Reynolds stresses. We then replaced the solid boundary with a layer of narrowly graded sand that has a median grain size (D50) of about 250 μm and made direct comparisons to the solid boundary measurements. Finally, in an effort to verify the ability to measure such flows in the field, we used a Nortek Aquadopp HR Profiler to measure vertical profiles over the depth of the tank and examine the Profiler’s ability to record accurate measurements at the fluid-sediment interface. Our analysis includes the determination of critical turbulent stresses responsible for sediment resuspension from the sand bed from which we develop a non-dimensional Shields-like parameter that captures incipient particle motion. We also make comparisons between simultaneous PIV and HR Profiler measurements to improve our understanding of

  19. Fundamental research on sintering technology with super deep bed achieving energy saving and reduction of emissions

    International Nuclear Information System (INIS)

    Hongliang Han; Shengli Wu; Gensheng Feng; Luowen Ma; Weizhong Jiang

    2012-01-01

    In the general frame of energy saving, environment protection and the concept of circular economy, the fundamental research on the sintering technology with super deep bed, achieving energy saving and emission reduction, was carried out. At first, the characteristics of the process and exhaust emission in the sintering with super deep bed was mastered through the study of the influence of different bed depths on the sintering process. Then, considering the bed permeability and the fuel combustion, their influence on the sinter yield and quality, their potential for energy saving and emission reduction was studied. The results show that the improvement of the bed permeability and of the fuel combustibility respectively and simultaneously, leads to an improvement of the sintering technical indices, to energy saving and emission reduction in the condition of super deep bed. At 1000 mm bed depth, and taking the appropriate countermeasure, it is possible to decrease the solid fuel consumption and the emission of CO 2 , SO 2 , NO x by 10.08%, 11.20%, 22.62% and 25.86% respectively; and at 700 mm bed depth, it is possible to reduce the solid fuel consumption and the emission of CO 2 , SO 2 , NO x by 20.71%, 22.01%, 58.86% and 13.13% respectively. This research provides the theoretical and technical basis for the new technology of sintering with super deep bed, achieving energy saving and reduction of emission. (authors)

  20. Modeling stationary and moving pebbles in a pebble bed reactor

    International Nuclear Information System (INIS)

    Zhao, Xiang; Montgomery, Trent; Zhang, Sijun

    2015-01-01

    Highlights: • The stationary and moving pebbles in a PBR are numerically studied by DEM. • The packing structure of stationary pebbles is simulated by a filling process. • The packing structural properties are obtained and analyzed. • The dynamic behavior of pebbles is predicted and discussed. - Abstract: This paper presents a numerical study of the stationary and moving pebbles in a pebble bed reactor (PBR) by means of discrete element method (DEM). The packing structure of stationary pebbles is simulated by a filling process that terminates with the settling of the pebbles into a PBR. The packing structural properties are obtained and analyzed. Subsequently, when the outlet of the PBR is opened during the operation of the PBR, the stationary pebbles start to flow downward and are removed at the bottom of the PBR. The dynamic behavior of pebbles is predicted and discussed. Our results indicate the DEM can offer both macroscopic and microscopic information for PBR design calculations and safety assessment

  1. Application and Discussion of Dual Fluidized Bed Reactor in Biomass Energy Utilization

    Science.gov (United States)

    Guan, Haibin; Fan, Xiaoxu; Zhao, Baofeng; Yang, Liguo; Sun, Rongfeng

    2018-01-01

    As an important clean and renewable energy, biomass has a broad market prospect. The dual fluidized bed is widely used in biomass gasification technology, and has become an important way of biomass high-value utilization. This paper describes the basic principle of dual fluidized bed gasification, from the gas composition, tar content and thermal efficiency of the system point of view, analyzes and summarizes several typical dual fluidized bed biomass gasification technologies, points out the existence of gas mixing, the external heat source, catalyst development problems on gas. Finally, it is clear that the gasification of biomass in dual fluidized bed is of great industrial application and development prospect.

  2. Reducing Respiratory Health Risks to Horses and Workers: A Comparison of Two Stall Bedding Materials

    Directory of Open Access Journals (Sweden)

    Markku Saastamoinen

    2015-10-01

    Full Text Available Stable air quality and the choice of bedding material are an important health issue both in horses and people working or visiting horse stables. Risks of impaired respiratory health are those that can especially be avoided by improving air quality in the stable. The choice of bedding material is particularly important in cold climate conditions; where horses are kept most of the day and year indoors throughout their life. This study examined the effect of two bedding materials; wood shavings and peat; on stable air quality and health of horses. Ammonia and dust levels were also measured to assess conditions in the stable. Ammonia was not detected or was at very low levels (<0.25 ppm in the boxes in which peat was used as bedding; but its concentration was clearly higher (1.5–7.0 ppm in stalls with wood shavings as bedding. Personal measurements of workers revealed quite high ammonia exposure (5.9 ppm8h in the boxes in which wood shavings were used; but no exposure was Animals 2015, 5 966 observed in stalls bedded with peat. The respiratory symptoms in horses increased regardless of the bedding material at the beginning of the study. The health status of the horses in the peat bedding group returned to the initial level in the end of the trial but horses bedded with wood shavings continued to be symptomatic. The hooves of the horses with peat bedding had a better moisture content than those of the horses bedded with wood shavings. The results suggest that peat is a better bedding material for horses than wood shavings regarding the health of both horses and stable workers.

  3. Pebble Bed Reactor: core physics and fuel cycle analysis

    Energy Technology Data Exchange (ETDEWEB)

    Vondy, D.R.; Worley, B.A.

    1979-10-01

    The Pebble Bed Reactor is a gas-cooled, graphite-moderated high-temperature reactor that is continuously fueled with small spherical fuel elements. The projected performance was studied over a broad range of reactor applicability. Calculations were done for a burner on a throwaway cycle, a converter with recycle, a prebreeder and breeder. The thorium fuel cycle was considered using low, medium (denatured), and highly enriched uranium. The base calculations were carried out for electrical energy generation in a 1200 MW/sub e/ plant. A steady-state, continuous-fueling model was developed and one- and two-dimensional calculations were used to characterize performance. Treating a single point in time effects considerable savings in computer time as opposed to following a long reactor history, permitting evaluation of reactor performance over a broad range of design parameters and operating modes.

  4. Histamine as an emergent indoor contaminant: Accumulation and persistence in bed bug infested homes.

    Directory of Open Access Journals (Sweden)

    Zachary C DeVries

    Full Text Available Histamine is used in bronchial and dermal provocation, but it is rarely considered an environmental risk factor in allergic disease. Because bed bugs defecate large amounts of histamine as a component of their aggregation pheromone, we sought to determine if histamine accumulates in household dust in bed bug infested homes, and the effects of bed bug eradication with spatial heat on histamine levels in dust. We collected dust in homes and analyzed for histamine before, and up to three months after bed bug eradication. Histamine levels in bed bug infested homes were remarkably high (mean = 54.6±18.9 μg/100 mg of sieved household dust and significantly higher than in control homes not infested with bed bugs (mean < 2.5±1.9 μg/100 mg of sieved household dust. Heat treatments that eradicated the bed bug infestations failed to reduce histamine levels, even three months after treatment. We report a clear association between histamine levels in household dust and bed bug infestations. The high concentrations, persistence, and proximity to humans during sleep suggest that bed bug-produced histamine may represent an emergent contaminant and pose a serious health risk in the indoor environment.

  5. A Comparison of Tandem Walk Performance Between Bed Rest Subjects and Astronauts

    Science.gov (United States)

    Miller, Chris; Peters, Brian; Kofman, Igor; Philips, Tiffany; Batson, Crystal; Cerisano, Jody; Fisher, Elizabeth; Mulavara, Ajitkumar; Feiveson, Alan; Reschke, Millard; hide

    2015-01-01

    Astronauts experience a microgravity environment during spaceflight, which results in a central reinterpretation of both vestibular and body axial-loading information by the sensorimotor system. Subjects in bed rest studies lie at 6deg head-down in strict bed rest to simulate the fluid shift and gravity-unloading of the microgravity environment. However, bed rest subjects still sense gravity in the vestibular organs. Therefore, bed rest isolates the axial-unloading component, thus allowing for the direct study of its effects. The Tandem Walk is a standard sensorimotor test of dynamic postural stability. In a previous abstract, we compared performance on a Tandem Walk test between bed rest control subjects, and short- and long-duration astronauts both before and after flight/bed rest using a composite index of performance, called the Tandem Walk Parameter (TWP), that takes into account speed, accuracy, and balance control. This new study extends the previous data set to include bed rest subjects who performed exercise countermeasures. The purpose of this study was to compare performance during the Tandem Walk test between bed rest subjects (with and without exercise), short-duration (Space Shuttle) crewmembers, and long-duration International Space Station (ISS) crewmembers at various time points during their recovery from bed rest or spaceflight.

  6. Nitrification performance and robustness of fixed and moving bed biofilters having identical carrier elements

    DEFF Research Database (Denmark)

    Pedersen, Lars-Flemming; Oosterveld, Remko; Pedersen, Per Bovbjerg

    2015-01-01

    This study compared moving bed (MB) and fixed bed (FB) biofilter performance. The experimental recir-culating aquaculture system had four equal biofilters in parallel. Each of the two replicated FB biofilters(with heavy elements) and the two MB biofilters (with neutral elements) had 200 l carrier...

  7. Carbon and nitrogen removal in a granular bed baffled reactor.

    Science.gov (United States)

    Baloch, M I; Akunna, J C; Collier, P J

    2006-02-01

    The application of an anaerobic five compartment granular bed baffled reactor (GRABBR) was investigated with brewery wastewater for combined carbon and nitrate removal, with a separate downstream nitrification unit for converting ammonia to nitrate. The GRABBR was operated at an organic loading rate of 3.57 kg chemical oxygen demand (COD) m(-3) d(-1) and ammoniacal nitrogen (NH4-N) loading rate of 0.13 kg NH4-N m(-3) d(-1) when nitrified effluent from a downstream nitrification unit was recycled to the feed point of the GRABBR. Carbonaceous matter and nitrate were removed simultaneously in the GRABBR at different recycle to influent ratios (from 1 to 2), with nitrogen oxide (nitrate and nitrite nitrogen, NOx-N) loading rates varying from 0.04 to 0.05 kg NOx-N m(-3) d(-1). At all recycle to influent ratios, COD removal efficiency of 97% to 98% were observed in the GRABBR, and over 99% by the two-stage treatment configuration (i.e. GRABBR and nitrification unit). All the nitrates added to the GRABBR were denitrified in the first three compartments of the system. For all the recycle to influent ratios studied, almost all ammonia was converted to nitrate nitrogen with only small traces of nitrite nitrogen in the nitrification unit. Methane production was observed throughout the experimental period with its composition varying from 25% to 50%, showing that simultaneous methanogenesis and denitrification occurred. This study shows that a GRABBR could bring about a high degree of carbon and nitrate removal, with simultaneous methanogenesis and denitrification, due to plug flow granular bed multi-stage characteristics of the bioreactor.

  8. Orthostatic hypotension in patients, bed rest subjects, and astronauts

    Science.gov (United States)

    Lathers, C. M.; Charles, J. B.

    1994-01-01

    Orthostatic hypotension after even short space flights has affected a significant number of astronauts. Given the need for astronauts to function at a high level of efficiency during and after their return from space, the application of pharmacologic and other treatments is strongly indicated. This report addresses the clinical problem of orthostatic hypotension and its treatments to ascertain whether pharmacologic or physiologic treatment may be useful in the prevention of orthostatic hypotension associated with space flight. Treatment of orthostatic hypotension in patients now includes increasing intravascular volume with high sodium intake and mineralocorticoids, or increasing vascular resistance through the use of drugs to stimulate alpha or block beta vascular receptors. Earlier treatment used oral sympathomimetic ephedrine hydrochloride alone or with "head-up" bed rest. Then long-acting adrenocortical steroid desoxycorticosterone preparations with high-salt diets were used to expand volume. Fludrocortisone was shown to prevent the orthostatic drop in blood pressure. The combination of the sympathomimetic amine hydroxyamphetamine and a monoamine oxidase inhibitor tranylcypromine has been used, as has indomethacin alone. Davies et al. used mineralocorticoids at low doses concomitantly with alpha-agonists to increase vasoconstrictor action. Schirger et al used tranylcypromine and methylphenidate with or without a Jobst elastic leotard garment or the alpha-adrenergic agonist midodrine (which stimulates both arterial and venous systems without direct central nervous system or cardiac effects). Vernikos et al established that the combination of fludrocortisone, dextroamphetamine, and atropine exhibited a beneficial effect on orthostatic hypotension induced by 7-day 6 degrees head-down bed rest (a model used to simulate the weightlessness of space flight). Thus, there are numerous drugs that, in combination with mechanical techniques, including lower body negative

  9. Effects and control of humidity and particle mixing in fluid-bed granulation

    NARCIS (Netherlands)

    Schaafsma, SH; Kossen, NWF; Mos, MT; Blauw, L; Hoffmann, AC

    The novel technique of spraying binder liquid in pulses of short duration on a bubbling fluidized bed was used to study the effect liquid distribution, mixing, and relative humidity has on granule growth. Two important mixing zones in the fluid-bed granulation process are identified. First, the

  10. SNS Central Helium Liquefier spare Carbon Bed installation and commissioning

    Energy Technology Data Exchange (ETDEWEB)

    Degraff, Brian D. [ORNL; Howell, Matthew P. [ORNL; Kim, Sang-Ho [ORNL; Neustadt, Thomas S. [ORNL

    2017-07-01

    The Spallation Neutron Source (SNS) Central Helium Liquefier (CHL) at Oak Ridge National Laboratory (ORNL) has been without major operations downtime since operations were started back in 2006. This system utilizes a vessel filled with activated carbon as the final major component to remove oil vapor from the compressed helium circuit prior to insertion into the system's cryogenic cold box. The need for a spare carbon bed at SNS due to the variability of carbon media lifetime calculation to adsorption efficiency will be discussed. The fabrication, installation and commissioning of this spare carbon vessel will be presented. The novel plan for connecting the spare carbon vessel piping to the existing infrastructure will be presented.

  11. SNS Central Helium Liquefier spare Carbon Bed installation and commissioning

    Science.gov (United States)

    DeGraff, B.; Howell, M.; Kim, S.; Neustadt, T.

    2017-12-01

    The Spallation Neutron Source (SNS) Central Helium Liquefier (CHL) at Oak Ridge National Laboratory (ORNL) has been without major operations downtime since operations were started back in 2006. This system utilizes a vessel filled with activated carbon as the final major component to remove oil vapor from the compressed helium circuit prior to insertion into the system’s cryogenic cold box. The need for a spare carbon bed at SNS due to the variability of carbon media lifetime calculation to adsorption efficiency will be discussed. The fabrication, installation and commissioning of this spare carbon vessel will be presented. The novel plan for connecting the spare carbon vessel piping to the existing infrastructure will be presented.

  12. Coupling Solute and Fine Particle Transport with Sand Bed Morphodynamics within a Field Experiment

    Science.gov (United States)

    Phillips, C. B.; Ortiz, C. P.; Schumer, R.; Jerolmack, D. J.; Packman, A. I.

    2017-12-01

    Fine suspended particles are typically considered to pass through streams and rivers as wash load without interacting with the bed, however experiments have demonstrated that hyporheic flow causes advective exchange of fine particles with the stream bed, yielding accumulation of fine particle deposits within the bed. Ultimately, understanding river morphodynamics and ecosystem dynamics requires coupling both fine particle and solute transport with bed morphodynamics. To better understand the coupling between these processes we analyze a novel dataset from a controlled field experiment conducted on Clear Run, a 2nd order sand bed stream located within the North Carolina coastal plain. Data include concentrations of continuously injected conservative solutes and fine particulate tracers measured at various depths within the stream bed, overhead time lapse images of bed forms, stream discharge, and geomorphological surveys of the stream. We use image analysis of bed morphodynamics to assess exchange, retention, and remobilization of solutes and fine particles during constant discharge and a short duration experimental flood. From the images, we extract a time series of bedform elevations and scour depths for the duration of the experiment. The high-resolution timeseries of bed elevation enables us to assess coupling of bed morphodynamics with both the solute and fine particle flux during steady state mobile bedforms prior to the flood and to changing bedforms during the flood. These data allow the application of a stochastic modeling framework relating bed elevation fluctuations to fine particle residence times. This combined experimental and modeling approach ultimately informs our ability to predict not only the fate of fine particulate matter but also associated nutrient and carbon dynamics within streams and rivers.

  13. Physiological effects of acute and ordinary bed rest conditions on endurance trained volunteers.

    Science.gov (United States)

    Zorbas, Y. G.; Ivanov, A. A.; Madvedev, S. N.; Kakurin, A. G.

    1999-12-01

    The aim of this study was to carry out a comparative study of water balance and water protein composition of the blood during exposure to acute (abrupt restriction of motor activity) and ordinary rigorous bed rest of 7 days. The studies were performed on 30 long distance runners aged 22-25 years old who had a VO 2 max of 66 ml kg -1·min -1 on the average. The volunteers were divided into three equal groups: the volunteers in the 1st group were under a normal ambulatory life conditions (control subjects), the volunteers of the 2nd group subjected to an acute bed rest (abrupt restriction of motor activity) regime (acute bed rested subjects) and the volunteers of the 3rd group were submitted to ordinary and rigorous bed rest (rigorous bed rested subjects). All volunteers were on an average of 13.8 km/day before taking part in this investigation. The 2nd and 3rd groups of volunteers were kept under a rigorous bed rest regime for 7 days. During the prebed rest period and actual bed rest period plasma volume (PV), total protein and protein fractions (albumins and globulins) and hematocrit were measured. Exposure to acute bed rest conditions induced a significant increase in hematocrit, hemoglobin concentration, protein fractions and marked decrease in (PV) and water balance which were significantly more pronounced than during exposure to ordinary rigorous bed rest. It was concluded that exposure to acute bed rest conditions induces significantly greater changes in water balance and water-protein concentration of the blood of endurance trained volunteers than exposure to ordinary rigorous bed rest conditions.

  14. The red bed period of geological history in northwest China and regional uranium mineralization

    International Nuclear Information System (INIS)

    Quan Zhigao; Zhou Qiaosheng; Zhang Jinbiao.

    1990-01-01

    This paper clarifies that uranium mineralization temporally occurs in the period of regional tension and red beds and spatially belongs to rich uranium geological body and overlapped area of downfaulted red basin by comprehensively analysing the geological development history in Northwest China, regional red beds and uranium mineralization

  15. Long-Duration Space Flight and Bed Rest Effects on Testosterone and Other Steroids

    Science.gov (United States)

    Heer, Martina; Wang, Zuwei; Huntoon, Carolyn L.; Zwart, Sara R.

    2012-01-01

    Context: Limited data suggest that testosterone is decreased during space flight, which could contribute to bone and muscle loss. Objective: The main objective was to assess testosterone and hormone status in long- and short-duration space flight and bed rest environments and to determine relationships with other physiological systems, including bone and muscle. Design: Blood and urine samples were collected before, during, and after long-duration space flight. Samples were also collected before and after 12- to 14-d missions and from participants in 30- to 90-d bed rest studies. Setting: Space flight studies were conducted on the International Space Station and before and after Space Shuttle missions. Bed rest studies were conducted in a clinical research center setting. Data from Skylab missions are also presented. Participants: All of the participants were male, and they included 15 long-duration and nine short-duration mission crew members and 30 bed rest subjects. Main Outcome Measures: Serum total, free, and bioavailable testosterone were measured along with serum and urinary cortisol, serum dehydroepiandrosterone, dehydroepiandrosterone sulfate, and SHBG. Results: Total, free, and bioavailable testosterone was not changed during long-duration space flight but were decreased (P space flight. There were no changes in other hormones measured. Testosterone concentrations dropped before and soon after bed rest, but bed rest itself had no effect on testosterone. Conclusions: There was no evidence for decrements in testosterone during long-duration space flight or bed rest. PMID:22049169

  16. Multiple Intelligence and Digital Learning Awareness of Prospective B.Ed Teachers

    Science.gov (United States)

    Gracious, F. L. Antony; Shyla, F. L. Jasmine Anne

    2012-01-01

    The present study Multiple Intelligence and Digital Learning Awareness of prospective B.Ed teachers was probed to find the relationship between Multiple Intelligence and Digital Learning Awareness of Prospective B.Ed Teachers. Data for the study were collected using self made Multiple Intelligence Inventory and Digital Learning Awareness Scale.…

  17. The Importance of Splat Events to the Spatiotemporal Structure of Near-Bed Fluid Velocity and Bed Load Motion Over Bed Forms: Laboratory Experiments Downstream of a Backward Facing Step

    Science.gov (United States)

    Leary, K. C. P.; Schmeeckle, M. W.

    2017-12-01

    Flow separation/reattachment on the lee side of alluvial bed forms is known to produce a complex turbulence field, but the spatiotemporal details of the associated patterns of bed load sediment transported remain largely unknown. Here we report turbulence-resolving, simultaneous measurements of bed load motion and near-bed fluid velocity downstream of a backward facing step in a laboratory flume. Two synchronized high-speed video cameras simultaneously observed bed load motion and the motion of neutrally buoyant particles in a laser light sheet 6 mm above the bed at 250 frames/s downstream of a 3.8 cm backward facing step. Particle Imaging Velocimetry (PIV) and Acoustic Doppler Velocimetry (ADV) were used to characterize fluid turbulent patterns, while manual particle tracking techniques were used to characterize bed load transport. Octant analysis, conducted using ADV data, coupled with Markovian sequence probability analysis highlights differences in the flow near reattachment versus farther downstream. Near reattachment, three distinct flow patterns are apparent. Farther downstream we see the development of a dominant flow sequence. Localized, intermittent, high-magnitude transport events are more apparent near flow reattachment. These events are composed of streamwise and cross-stream fluxes of comparable magnitudes. Transport pattern and fluid velocity data are consistent with the existence of permeable "splat events," wherein a volume of fluid moves toward and impinges on the bed (sweep) causing a radial movement of fluid in all directions around the point of impingement (outward interaction). This is congruent with flow patterns, identified with octant analysis, proximal to flow reattachment.

  18. Fibroblast Growth Factor-23 in Bed Rest and Spaceflight

    Science.gov (United States)

    Bokhari, R.; Zwart, S. R; Fields, E.; Heer, M.; Sibonga, J.; Smith, S. M.

    2014-01-01

    Many nutritional factors influence bone, from the basics of calcium and vitamin D, to factors which influence bone through acid/base balance, including protein, sodium, and more. Fibroblast growth factor 23 (FGF23) is a recently identified factor, secreted from osteocytes, which is involved in classic (albeit complex) feedback loops controlling phosphorus homeostasis through both vitamin D and parathyroid hormone (PTH) (1, 2). As osteocytes are gravity sensing cells, it is important to determine if there are changes in FGF23 during spaceflight. In extreme cases, such as chronic kidney disease, FGF23 levels are highly elevated. FGF23 imbalances, secondary to dietary influences, may contribute to skeletal demineralization and kidney stone risk during spaceflight. Presented with an imbalanced dietary phosphorus to calcium ratio, increased secretion of FGF23 will inhibit renal phosphorus reabsorption, resulting in increased excretion and reduced circulating phosphorus. Increased intake and excretion of phosphorus is associated with increased kidney stone risk in both the terrestrial and microgravity environments. Highly processed foods and carbonated beverages are associated with higher phosphorus content. Ideally, the dietary calcium to phosphorus ratio should be at minimum 1:1. Nutritional requirements for spaceflight suggest that this ratio not be less than 0.67 (3), while the International Space Station (ISS) menu provides 1020 mg Ca and 1856 mg P, for a ratio of 0.55 (3). Subjects in NASA's bed rest studies, by design, have consumed intake ratios much closer to 1.0 (4). FGF23 also has an inhibitory influence on PTH secretion and 1(alpha)-hydroxylase, both of which are required for activating vitamin D with the conversion of 25-hydroxyvitamin D to 1,25-dihydroxyvitamin D. Decreased 1,25-dihydroxyvitamin D will result in decreased intestinal phosphorus absorption, and increased urinary phosphorus excretion (via decreased renal reabsorption). Should a decrease in 1

  19. Long-term bed degradation in Maryland streams (phase 2) : Blue Ridge and Western Piedmont provinces.

    Science.gov (United States)

    2012-03-01

    Estimation of potential long-term down-cutting of the stream bed is necessary for evaluation and design of bridges for scour and culverts for fish passage. The purpose of this study has been to improve predictions of this potential long-term bed degr...

  20. Turbulent flow and sand transport over a cobble bed in a laboratory flume

    Science.gov (United States)

    The turbulence structure of flow over rough beds and its interaction with fine sediments in the bed are important for efforts to predict sediment transport downstream of dams. The advanced age and impending decommissioning of many dams have brought increased attention to the fate of sediments stored...

  1. Time and speed of fruit drying on batch fluid-beds

    Indian Academy of Sciences (India)

    Drying of particles (pieces) in a fluidized bed affords better quality of end products, especially for better product structure and its shorter reconstitution time. Fluid-bed drying of different fruit particles has been investigated. Starting water content varies from grape berries 81·5% and peach 87·7% to apricot 86·9%.

  2. Effect strooiselmateriaal, strooiselhoeveelheid, opvangschoteltjes en waterdruk op resultaten vleeskuikens = Influence of bedding material, bedding amount, drip cup and reduced water pressure on broiler performance

    NARCIS (Netherlands)

    Harn, van J.; Jong, de I.C.; Veldkamp, T.

    2009-01-01

    Four different bedding materials for broiler houses were compared: white wood shavings, chopped wheat straw, ground rapeseed straw and silage maize. Performance results, carcass yields, litter quality, broiler quality and gait score were measured.

  3. Bed bugs, their blood sources and life history parameters: a comparison of artificial and natural feeding.

    Science.gov (United States)

    Aak, A; Rukke, B A

    2014-03-01

    A blood-feeding system that utilizes a small amount of whole heparinized human blood in parafilm bags is described in detail, and similarities and differences between artificially fed and naturally rodent-fed bed bugs (Hemiptera: Cimicidae) are discussed. Blood with high levels of heparin (10%) was unsuitable for artificial colony rearing, whereas bed bugs fed on 1% heparinized blood and those that naturally ingested rat blood completed their lifecycle with similar stage structures over time, with no significant differences in mortality. No differences in feeding efficiency or fertility were found in a direct comparison of bed bugs maintained under each of these two treatments, but analysis of the full lifecycle revealed that artificially fed bed bugs became significantly smaller and laid fewer eggs than rodent-fed bed bugs. The level of membrane stretching regulated the number of bed bugs that fed. When the membrane was stretched to twice its length and width, 96% of bed bugs successfully fed through the parafilm. Whole heparinized blood that was stored at 6 °C for ≥ 14 days failed to retain its nutritional value and the amount of blood consumed and number of consecutive moults were significantly reduced. © 2013 The Royal Entomological Society.

  4. Major salt beds of the Palo Duro and Dalhart Basins, Texas

    International Nuclear Information System (INIS)

    1983-12-01

    Major salt beds are defined as salt intervals at least 75 feet thick that contain no interbeds greater than 10 feet thick and include no more than 15 percent non-salt interbeds. Maps based on the interpretation of geophysical logs from hundreds of oil and gas exploration wells reveal seven major salt beds in the Palo Duro Basin and one major salt bed in the Dalhart Basin. The most extensive major salt beds are in the central and northern Palo Duro Basin, in the Upper San Andres Formation and the Lower San Andres Formation Units 4 and 5. Of these, the major salt bed within the Lower San Andres Formation Unit 4 is the most widespread and generally the thickest. 7 references, 15 figures, 2 tables

  5. The Dynamic Behavior of Water Flowing Through Packed Bed of Different Particle Shapes and Sizes

    Directory of Open Access Journals (Sweden)

    Haneen Ahmed Jasim

    2017-12-01

    Full Text Available An experimental study was conducted on pressure drop of water flow through vertical cylindrical packed beds in turbulent region and the influence of the operating parameters on its behavior. The bed packing was made of spherical and non-spherical particles (spheres, Rasching rings and intalox saddle with aspect ratio range 3.46 D/dp 8.486 obtaining bed porosities 0.396 0.84 and Reynolds number 1217 21758. The system is consisted of 5 cm inside diameter Perspex column, 50 cm long; distilled water was pumped through the bed with flow rate 875, 1000, 1125, 1250,1375 and 1500 l/h and inlet water temperature 20, 30, 40 and 50 ˚C. The packed bed system was monitored by using LabVIEW program, were the results have been obtained from Data Acquisition Adaptor (DAQ.

  6. Fluidized bed spray granulation: analysis of heat and mass transfers and dynamic particle populations

    Directory of Open Access Journals (Sweden)

    S. Heinrich

    2005-06-01

    Full Text Available A model was developed taking into consideration the heat and mass transfer processes in liquid-sprayed fluidized beds. Such fluidized beds (FB are used for granulation, coating and agglomeration. Conclusions are drawn on the relevance of particle dispersion, spraying and drying to temperature and concentrations distributions. In extension, the model was coupled with a population balance model to describe the particle size distribution and the seeds formation for continuous external FBSG (fluidized bed spray granulation with non-classifying product discharge and a screening and milling unit in the seeds recycle. The effects of seeds formation on the stability of the process is discussed.

  7. Pebble-bed pebble motion: Simulation and Applications

    International Nuclear Information System (INIS)

    Cogliati, Joshua J.; Ougouag, Abderrafi M.

    2011-01-01

    Pebble bed reactors (PBR) have moving graphite fuel pebbles. This unique feature provides advantages, but also means that simulation of the reactor requires understanding the typical motion and location of the granular flow of pebbles. This report presents a method for simulation of motion of the pebbles in a PBR. A new mechanical motion simulator, PEBBLES, efficiently simulates the key elements of motion of the pebbles in a PBR. This model simulates gravitational force and contact forces including kinetic and true static friction. It's used for a variety of tasks including simulation of the effect of earthquakes on a PBR, calculation of packing fractions, Dancoff factors, pebble wear and the pebble force on the walls. The simulator includes a new differential static friction model for the varied geometries of PBRs. A new static friction benchmark was devised via analytically solving the mechanics equations to determine the minimum pebble-to-pebble friction and pebble-to-surface friction for a five pebble pyramid. This pyramid check as well as a comparison to the Janssen formula was used to test the new static friction equations. Because larger pebble bed simulations involve hundreds of thousands of pebbles and long periods of time, the PEBBLES code has been parallelized. PEBBLES runs on shared memory architectures and distributed memory architectures. For the shared memory architecture, the code uses a new O(n) lock-less parallel collision detection algorithm to determine which pebbles are likely to be in contact. The new collision detection algorithm improves on the traditional non-parallel O(n log(n)) collision detection algorithm. These features combine to form a fast parallel pebble motion simulation. The PEBBLES code provides new capabilities for understanding and optimizing PBRs. The PEBBLES code has provided the pebble motion data required to calculate the motion of pebbles during a simulated earthquake. The PEBBLES code provides the ability to determine

  8. Pebble-bed pebble motion: Simulation and Applications

    Energy Technology Data Exchange (ETDEWEB)

    Joshua J. Cogliati; Abderrafi M. Ougouag

    2011-11-01

    Pebble bed reactors (PBR) have moving graphite fuel pebbles. This unique feature provides advantages, but also means that simulation of the reactor requires understanding the typical motion and location of the granular flow of pebbles. This report presents a method for simulation of motion of the pebbles in a PBR. A new mechanical motion simulator, PEBBLES, efficiently simulates the key elements of motion of the pebbles in a PBR. This model simulates gravitational force and contact forces including kinetic and true static friction. It's used for a variety of tasks including simulation of the effect of earthquakes on a PBR, calculation of packing fractions, Dancoff factors, pebble wear and the pebble force on the walls. The simulator includes a new differential static friction model for the varied geometries of PBRs. A new static friction benchmark was devised via analytically solving the mechanics equations to determine the minimum pebble-to-pebble friction and pebble-to-surface friction for a five pebble pyramid. This pyramid check as well as a comparison to the Janssen formula was used to test the new static friction equations. Because larger pebble bed simulations involve hundreds of thousands of pebbles and long periods of time, the PEBBLES code has been parallelized. PEBBLES runs on shared memory architectures and distributed memory architectures. For the shared memory architecture, the code uses a new O(n) lock-less parallel collision detection algorithm to determine which pebbles are likely to be in contact. The new collision detection algorithm improves on the traditional non-parallel O(n log(n)) collision detection algorithm. These features combine to form a fast parallel pebble motion simulation. The PEBBLES code provides new capabilities for understanding and optimizing PBRs. The PEBBLES code has provided the pebble motion data required to calculate the motion of pebbles during a simulated earthquake. The PEBBLES code provides the ability to

  9. Biometrics for Emotion Detection (BED): Exploring the combination of Speech and ECG

    NARCIS (Netherlands)

    Schut, Marleen H.; Tuinenbreijer, Kees; van den Broek, Egon; Westerink, Joyce H.D.M.; Kim, Jonghwa; Karjalainen, Pasi

    2010-01-01

    The paradigm Biometrics for Emotion Detection (BED) is introduced, which enables unobtrusive emotion recognition, taking into account varying environments. It uses the electrocardiogram (ECG) and speech, as a powerful but rarely used combination to unravel people’s emotions. BED was applied in two

  10. Discrete element modeling and fibre optical measurements for fluidized bed spray granulation

    NARCIS (Netherlands)

    Link, J.M.; Godlieb, W.; Deen, N.G.; Heinrich, S.; Tripp, P.; Peglow, M.; Kuipers, J.A.M.; Schönherr, M.; Mörl, L.

    2007-01-01

    Spout fluidized beds are frequently used for the production of granules or particles through granulation. The products find application in a large variety of applications, for example detergents, fertilizers, pharmaceuticals and food. Spout fluidized beds have a number of advantageous properties,

  11. Caribbean mangroves and seagrass beds as diurnal feeding habitats for juvenile French grunts, Haemulon flavolineatum.

    NARCIS (Netherlands)

    Verwey, M.C.; Nagelkerken, I.; Wartenbergh, S.L.J.; Pen, I.R.; Velde, G. van der

    2006-01-01

    Abstract Caribbean seagrass beds are important feeding habitats for so-called nocturnally active zoobenthivorous fish, but the extent to which these fishes use mangroves and seagrass beds as feeding habitats during daytime remains unclear. We hypothesised three feeding strategies: (1) fishes feed

  12. Examining the generality of Tau_0/TKE for gravel and cobble beds with sand fill

    Science.gov (United States)

    Turbulence measurements over rough beds are used for a variety of purposes, including studies of habitat diversity for aquatic organisms, stream restoration efforts, and assessment of drag induced by vegetation. Turbulent Kinetic Energy (TKE) has been used to determine bed shear stress by use of a ...

  13. Hydrodynamic processes and the stability of intertidal mussel beds in the Dutch Wadden Sea

    NARCIS (Netherlands)

    Donker, J.J.A.

    2015-01-01

    The mussel population in the Dutch Wadden Sea, especially in the Western parts, is currently under pressure. Hydrodynamic process influence intertidal mussel beds in two ways: on the one hand currents are responsible for the transfer of food and sediments towards the beds, on the other hand, large

  14. Caribbean mangroves and seagrass beds as daytime feeding habitats for juvenile French grunts, Haemulon flavolineatum

    NARCIS (Netherlands)

    Verweij, M.C.; Nagelkerken, I.; Wartenbergh, S.L.J.; Pen, I.R.; Van der Velde, G.

    Caribbean seagrass beds are important feeding habitats for so-called nocturnally active zoobenthivorous fish, but the extent to which these fishes use mangroves and seagrass beds as feeding habitats during daytime remains unclear. We hypothesised three feeding strategies: (1) fishes feed

  15. Measurement of the thermal conductivity and heat transfer coefficient of a binary bed of beryllium pebbles

    Energy Technology Data Exchange (ETDEWEB)

    Donne, M.D.; Piazza, G. [Forschungszentrum Karlsruhe GmbH Technik und Umwelt (Germany). Inst. fuer Neutronenphysik und Reaktortechnik; Goraieb, A.; Sordon, G.

    1998-01-01

    The four ITER partners propose to use binary beryllium pebble bed as neutron multiplier. Recently this solution has been adopted for the ITER blanket as well. In order to study the heat transfer in the blanket the effective thermal conductivity and the wall heat transfer coefficient of the bed have to be known. Therefore at Forschungszentrum Karlsruhe heat transfer experiments have been performed with a binary bed of beryllium pebbles and the results have been correlated expressing thermal conductivity and wall heat transfer coefficients as a function of temperature in the bed and of the difference between the thermal expansion of the bed and of that of the confinement walls. The comparison of the obtained correlations with the data available from the literature show a quite good agreement. (author)

  16. An assessment of biological processes close to the sea bed in a slope region and its significance to the assessment of sea bed disposal of radioactive waste

    International Nuclear Information System (INIS)

    Hargreaves, P.M.; Ellis, C.J.; Angel, M.V.

    1984-01-01

    Vertical profiles of planktonic and micronektonic biomass observed close to the sea bed along a transect running up the continental slope on the southern flank of the Porcupine Seabight (to the southwest of Ireland) showed that a doubling in biomass concentration occurs from 100 to 10m above the sea bed. Comparison with biomass concentrations at two deep water stations, one in the Seabight and the other in the Rockall Trough, showed that there was a consistent increase in standing crop close to the sea bed over the slope. Supplementary data were collected on the northern flank of the Seabight. Analysis of both taxonomic groups and individual species showed that some taxa were more abundant near the sea floor and extended their vertical ranges to greater depths over the slope than over deep water, other taxa were unaffected. The implications to the problem of assessing the safety of sea bed disposal of high level radioactive waste are summarised. (author)

  17. Synthesis and crystal structure of lithium beryllium deuteride Li2BeD4.

    Science.gov (United States)

    Bulychev, Boris M; Shpanchenko, Roman V; Antipov, Evgeny V; Sheptyakov, Denis V; Bushmeleva, Svetlana N; Balagurov, Anatoly M

    2004-10-04

    Single-phase ternary deuteride Li(2)BeD(4) was synthesized by a high-pressure high-temperature technique from LiD and BeD(2). The crystal structure of Li(2)BeD(4) was solved from X-ray and neutron powder diffraction data. The compound crystallizes in the monoclinic space group P2(1)/c with lattice parameters a = 7.06228(9) A, b = 8.3378(1) A, c = 8.3465(1) A, beta =93.577(1) degrees, and Z = 8. Its structure contains isolated BeD(4) tetrahedra and Li atoms that are located in the structure interstices. Li(2)BeD(4) does not undergo any structural phase transitions at temperatures down to 8 K.

  18. Research into Biomass and Waste Gasification in Atmospheric Fluidized Bed

    Energy Technology Data Exchange (ETDEWEB)

    Skala, Zdenek; Ochrana, Ladislav; Lisy, Martin; Balas, Marek; Kohout, Premysl; Skoblja, Sergej

    2007-07-01

    Considerable attention is paid in the Czech Republic to renewable energy sources. The largest potential, out of them all, have biomass and waste. The aim therefore is to use them in CHP in smaller units (up to 5MWel). These are the subject of the research summarized in our article. The paper presents results of experimental research into gasification in a 100 kW AFB gasifier situated in Energy Institute, Faculty of Mechanical Engineering, Brno University of Technology, and fitted with gas cleaning equipment. Within the research, study was carried out into gas cleaning taking primary measures in the fluidized bed and using hot filter, metal-based catalytic filter, and wet scrubber. Descriptions and diagrams are given of the gasifier and new ways of cleaning. Results include: Impact of various fuels (farming and forest wastes and fast-growing woods and culm plants) on fuel gas quality. Individual kinds of biomass have very different thermal and physical properties; Efficiency of a variety of cleaning methods on content of dust and tars and comparison of these methods; and, Impact of gasifier process parameters on resultant gas quality. (auth)

  19. Integrated automatic and continuous bedload monitoring in gravel bed rivers

    Science.gov (United States)

    Habersack, Helmut; Kreisler, Andrea; Rindler, Rolf; Aigner, Johann; Seitz, Hugo; Liedermann, Marcel; Laronne, Jonathan B.

    2017-08-01

    Bedload monitoring techniques have been developed and applied for many years in rivers ranging from steep mountain torrents to the large gravel-bed Danube River in Austria. Most monitoring stations use a combination of direct (mobile bag samplers, slot samplers) and indirect (geophones, hydrophones) measurement methods. Each individual technique is adequate, yet features particular boundary conditions and limitations related to hydraulic and sampling efficiency, functionality during floods, sampling duration or grain size. We show the capabilities and limitations of the different monitoring devices with respect to technical, operational and economic criteria, evaluating their suitability for determining bedload transport parameters. Bedload monitoring results of a measuring site at the Drau River in Carinthia/Austria are used to illustrate the specific range of the device application. We present an integrated automatic and continuous bedload monitoring system. It complements the specific limitations of single monitoring methods by additional measurement devices, enabling comprehensive monitoring of the bedload transport process. We then derive the Bedload Discharge Integrated Calculation Approach and the Bedload Rating Curve Approach and discuss their application for determining bedload discharge Qb and total bedload mass Vb. Whereas the integrated approach combines data from direct monitoring methods with indirect techniques, the rating curve approach uses only data from direct bedload monitoring devices. We demonstrate that applying an integrated automatic and continuous bedload monitoring system and combining the Bedload Discharge Integrated Calculation Approach and Bedload Rating Curve Approach yields accurate bedload discharge results.

  20. Multiagency Urban Search Experiment Detector and Algorithm Test Bed

    Science.gov (United States)

    Nicholson, Andrew D.; Garishvili, Irakli; Peplow, Douglas E.; Archer, Daniel E.; Ray, William R.; Swinney, Mathew W.; Willis, Michael J.; Davidson, Gregory G.; Cleveland, Steven L.; Patton, Bruce W.; Hornback, Donald E.; Peltz, James J.; McLean, M. S. Lance; Plionis, Alexander A.; Quiter, Brian J.; Bandstra, Mark S.

    2017-07-01

    In order to provide benchmark data sets for radiation detector and algorithm development, a particle transport test bed has been created using experimental data as model input and validation. A detailed radiation measurement campaign at the Combined Arms Collective Training Facility in Fort Indiantown Gap, PA (FTIG), USA, provides sample background radiation levels for a variety of materials present at the site (including cinder block, gravel, asphalt, and soil) using long dwell high-purity germanium (HPGe) measurements. In addition, detailed light detection and ranging data and ground-truth measurements inform model geometry. This paper describes the collected data and the application of these data to create background and injected source synthetic data for an arbitrary gamma-ray detection system using particle transport model detector response calculations and statistical sampling. In the methodology presented here, HPGe measurements inform model source terms while detector response calculations are validated via long dwell measurements using 2"×4"×16" NaI(Tl) detectors at a variety of measurement points. A collection of responses, along with sampling methods and interpolation, can be used to create data sets to gauge radiation detector and algorithm (including detection, identification, and localization) performance under a variety of scenarios. Data collected at the FTIG site are available for query, filtering, visualization, and download at muse.lbl.gov.

  1. Design and simulation of a circulating fluidized bed to clean the products of biomass gasification

    Energy Technology Data Exchange (ETDEWEB)

    Uchoa Neto, Moises; Carvalho, Yuri de Araujo [Dept. de Engenharia Mecanica. Faculdade de Tecnologia. Universidade de Brasilia, DF (Brazil); Oliveira, Taygoara Felamingo de; Barcelos, Manuel [Faculdade do Gama. Universidade de Brasilia, Gama, DF (Brazil)], e-mail: taygoara@unb.br

    2010-07-01

    The main goal of this work is to design a workbench circulating fluidized bed to study the cracking of tar in gases from the processes of biomass gasification. For this, a design methodology based on analytical results and empirical correlations for fluidized beds was employed. In parallel, a numerical code of open source technology (MFIX) for the solution of the transport equations of the multiphase flow in the column of a fluidized bed was used to give support to the choice of the design elements. The whole project of the workbench fluidized bed was completely developed, whose operation parameters such as bed geometry, gas velocity, circulating ratio and void fraction characterize a fast fluidization process. A preliminary mesh convergence study was executed with the numerical tool, that was validated comparing with analytical results. Among the most important results, the code computed the predicted value for the minimum fluidization. (author)

  2. Sustainability and the Fixed Bed Nuclear Reactor (FBNR

    Directory of Open Access Journals (Sweden)

    Farhang Sefidvash

    2012-08-01

    Full Text Available Sustainability as a multifaceted and holistic concept is analyzed. Sustainability involves human relationship with elements such as natural environment, economy, power, governance, education and technology with the ultimate purpose of carrying forward an ever-advancing civilization. The Fixed Bed Nuclear Reactor (FBNR is an innovative, small, simple in design, inherently safe, non-proliferating, and environmentally friendly concept that its deployment can generate energy in a sustainable manner contributing to the prosperity of humanity. The development of FBNR will provide electricity as well as desalinated water through a simple but advanced technology for the developing, as well as developed countries. FBNR is environmentally friendly due to its inherent safety and the convenience of using its spent fuel as the source of radiation for irradiation purposes in agriculture, industry, and medicine. Politically, if a ping pong game brought peace between China and USA, a program of development of FBNR supported by the peace loving international community can become a more mature means to bring peace among certain apparently hostile nations who crave sustainable energy, desalinated water and simple advanced technology.

  3. Roughness coefficient and its uncertainty in gravel-bed river

    Directory of Open Access Journals (Sweden)

    Ji-Sung Kim

    2010-06-01

    Full Text Available Manning's roughness coefficient was estimated for a gravel-bed river reach using field measurements of water level and discharge, and the applicability of various methods used for estimation of the roughness coefficient was evaluated. Results show that the roughness coefficient tends to decrease with increasing discharge and water depth, and over a certain range it appears to remain constant. Comparison of roughness coefficients calculated by field measurement data with those estimated by other methods shows that, although the field-measured values provide approximate roughness coefficients for relatively large discharge, there seems to be rather high uncertainty due to the difference in resultant values. For this reason, uncertainty related to the roughness coefficient was analyzed in terms of change in computed variables. On average, a 20% increase of the roughness coefficient causes a 7% increase in the water depth and an 8% decrease in velocity, but there may be about a 15% increase in the water depth and an equivalent decrease in velocity for certain cross-sections in the study reach. Finally, the validity of estimated roughness coefficient based on field measurements was examined. A 10% error in discharge measurement may lead to more than 10% uncertainty in roughness coefficient estimation, but corresponding uncertainty in computed water depth and velocity is reduced to approximately 5%. Conversely, the necessity for roughness coefficient estimation by field measurement is confirmed.

  4. Packed bed reactor treatment of liquid hazardous and mixed wastes

    International Nuclear Information System (INIS)

    Tennant, R.A.; Wantuck, P.J.; Vargas, R.

    1992-01-01

    We are developing thermal-based packed bed reactor (PBR) technology as an alternative to incineration for treatment of hazardous organic liquid wastes. The waste streams targeted by this technology are machining fluids contaminated with chlorocarbons and/or chlorofluorocarbons and low levels of plutonium or tritium The PBR offers several distinct advantages including simplistic design, rugged construction, ambient pressure processing, economical operations, as well as ease of scalability and maintainability. In this paper, we provide a description of the apparatus as well as test results using prepared mixtures of machining oils/emulsions with trichloroethylene (TCE), carbon tetrachloride (CCl 4 ), trichloroethane (TCA), and Freon TF. The current treatment system is configured as a two stage device with the PBR (1st stage) coupled to a silent discharge plasma (SDP) cell. The SDP serves as a second stage for further treatment of the gaseous effluent from the PBR. One of the primary advantages of this two stage system is that its suitability for closed loop operation where radioactive components are well contained and even CO 2 is not released to the environment

  5. Nonlinear instability and convection in a vertically vibrated granular bed

    Science.gov (United States)

    Shukla, Priyanka; Ansari, I. H.; van der Meer, D.; Lohse, Detlef; Alam, Meheboob

    2015-11-01

    The nonlinear instability of the density-inverted granular Leidenfrost state and the resulting convective motion in strongly shaken granular matter are analysed via a weakly nonlinear analysis. Under a quasi-steady ansatz, the base state temperature decreases with increasing height away from from the vibrating plate, but the density profile consists of three distinct regions: (i) a collisional dilute layer at the bottom, (ii) a levitated dense layer at some intermediate height and (iii) a ballistic dilute layer at the top of the granular bed. For the nonlinear stability analysis, the nonlinearities up-to cubic order in perturbation amplitude are retained, leading to the Landau equation. The genesis of granular convection is shown to be tied to a supercritical pitchfork bifurcation from the Leidenfrost state. Near the bifurcation point the equilibrium amplitude is found to follow a square-root scaling law, Ae √{ ▵} , with the distance ▵ from bifurcation point. The strength of convection is maximal at some intermediate value of the shaking strength, with weaker convection both at weaker and stronger shaking. Our theory predicts a novel floating-convection state at very strong shaking.

  6. Beyond the bed: Effects of metal contamination on recruitment to bedded sediments and overlying substrata

    International Nuclear Information System (INIS)

    Hill, Nicole A.; Simpson, Stuart L.; Johnston, Emma L.

    2013-01-01

    Metal-contaminated sediments pose a recognised threat to sediment-dwelling fauna. Re-mobilisation of contaminated sediments however, may impact more broadly on benthic ecosystems, including on diverse assemblages living on hard substrata patches immediately above sediments. We used manipulative field experiments to simultaneously test for the effects of metal contamination on recruitment to marine sediments and overlying hard substrata. Recruitment to sediments was strongly and negatively affected by metal contamination. However, while assemblage-level effects on hard-substratum fauna and flora were observed, most functional groups were unaffected or slightly enhanced by exposure to contaminated sediments. Diversity of hard-substratum fauna was also enhanced by metal contamination at one site. Metal-contaminated sediments appear to pose less of a hazard to hard-substratum than sediment-dwelling assemblages, perhaps due to a lower direct contaminant exposure or to indirect effects mediated by contaminant impacts on sediment fauna. Our results indicate that current sediment quality guidelines are protective of hard-substrata organisms. - Highlights: ► Potential for contaminated sediments to exert impacts beyond the sediment communities. ► We examine effects on recruitment to sediments and overlying hard substrata simultaneously. ► Metal-contaminated sediments had a strong negative impact on sediment fauna. ► Metal-contaminated sediments pose less of a hazard to hard-substratum fauna. ► Sediment quality guidelines are likely protective of hard-substrata organisms. - Under natural disturbance regimes, metal-contaminated sediments pose less of a direct risk to hard-substratum fauna than to sediment-dwelling fauna and SQG appear appropriate.

  7. Raising distillate selectivity and catalyst life time in Fischer-Tropsch synthesis by using a novel dual-bed reactor

    International Nuclear Information System (INIS)

    Tavasoli, A.; Sadaghiani, K.; Khodadadi, A. A.; Mortazavi, Y.

    2007-01-01

    In a novel dual bed reactor Fischer-Tropsch synthesis was studied by using two diff rent cobalt catalysts. An alkali-promoted cobalt catalyst was used in the first bed of a fixed-bed reactor followed by a Raiment promoted cobalt catalyst in the second bed. The activity, product selectivity and accelerated deactivation of the system were assessed and compared with a conventional single bed reactor system. The methane selectivity in the dual-bed reactor was about 18.9% less compared to that of the single-bed reactor. The C 5+ selectivity for the dual-bed reactor was 10.9% higher than that of the single-bed reactor. Accelerated deactivation of the catalysts in the dual-bed reactor was 42% lower than that of the single-bed reactor. It was revealed that the amount of catalysts activity recovery after regeneration at 400 d eg C in the dual-bed system is higher than that of the single-bed system

  8. Gasification of Coal and PET in Fluidized Bed Reactor

    Czech Academy of Sciences Publication Activity Database

    Pohořelý, Michael; Vosecký, Martin; Kameníková, Petra; Punčochář, Miroslav; Skoblia, Sergej; Staf, M.; Vošta, J.; Koutský, B.; Svoboda, Karel

    2006-01-01

    Roč. 85, 17-18 (2006), s. 2458-2468 ISSN 0016-2361 R&D Projects: GA ČR(CZ) GA104/04/0829 Institutional research plan: CEZ:AV0Z40720504 Keywords : fludized bed * gasification * plastic waste Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 1.358, year: 2006

  9. [Prediction model of health workforce and beds in county hospitals of Hunan by multiple linear regression].

    Science.gov (United States)

    Ling, Ru; Liu, Jiawang

    2011-12-01

    To construct prediction model for health workforce and hospital beds in county hospitals of Hunan by multiple linear regression. We surveyed 16 counties in Hunan with stratified random sampling according to uniform questionnaires,and multiple linear regression analysis with 20 quotas selected by literature view was done. Independent variables in the multiple linear regression model on medical personnels in county hospitals included the counties' urban residents' income, crude death rate, medical beds, business occupancy, professional equipment value, the number of devices valued above 10 000 yuan, fixed assets, long-term debt, medical income, medical expenses, outpatient and emergency visits, hospital visits, actual available bed days, and utilization rate of hospital beds. Independent variables in the multiple linear regression model on county hospital beds included the the population of aged 65 and above in the counties, disposable income of urban residents, medical personnel of medical institutions in county area, business occupancy, the total value of professional equipment, fixed assets, long-term debt, medical income, medical expenses, outpatient and emergency visits, hospital visits, actual available bed days, utilization rate of hospital beds, and length of hospitalization. The prediction model shows good explanatory and fitting, and may be used for short- and mid-term forecasting.

  10. Development of Bed Ridges in Open Channels and their Effects on Secondary Currents and Wall Shear

    OpenAIRE

    Kamran Ansari; Ashfaque Ahmed Memon; Naeem Aziz Memon

    2012-01-01

    A numerical analysis of the ridges on the bed of wide, open channels and their effects on the distribution of secondary currents and wall shear is undertaken using CFD (Computational Fluid Dynamics). The presence of the lines of boil, consisting of low speed streaks, periodically in the transverse direction, is reported in the literature due to the presence of the ridges. In the present work, simulations are run on channel sections with varying the number of ridges on the bed and ...

  11. Process analytical tools for monitoring, understanding, and control of pharmaceutical fluidized bed granulation: A review.

    Science.gov (United States)

    Burggraeve, Anneleen; Monteyne, Tinne; Vervaet, Chris; Remon, Jean Paul; De Beer, Thomas

    2013-01-01

    Fluidized bed granulation is a widely applied wet granulation technique in the pharmaceutical industry to produce solid dosage forms. The process involves the spraying of a binder liquid onto fluidizing powder particles. As a result, the (wetted) particles collide with each other and form larger permanent aggregates (granules). After spraying the required amount of granulation liquid, the wet granules are rapidly dried in the fluid bed granulator. Since the FDA launched its Process Analytical Technology initiative (and even before), a wide range of analytical process sensors has been used for real-time monitoring and control of fluid bed granulation processes. By applying various data analysis techniques to the multitude of data collected from the process analyzers implemented in fluid bed granulators, a deeper understanding of the process has been achieved. This review gives an overview of the process analytical technologies used during fluid bed granulation to monitor and control the process. The fundamentals of the mechanisms contributing to wet granule growth and the characteristics of fluid bed granulation processing are briefly discussed. This is followed by a detailed overview of the in-line applied process analyzers, contributing to improved fluid bed granulation understanding, modeling, control, and endpoint detection. Analysis and modeling tools enabling the extraction of the relevant information from the complex data collected during granulation and the control of the process are highlighted. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Bed and width oscillations form coherent patterns in a partially confined, regulated gravel-cobble-bedded river adjusting to anthropogenic disturbances

    Science.gov (United States)

    Brown, Rocko A.; Pasternack, Gregory B.

    2017-01-01

    Understanding the spatial organization of river systems in light of natural and anthropogenic change is extremely important because it can provide information to assess, manage, and restore them to ameliorate worldwide freshwater fauna declines. For gravel- and cobble-bedded alluvial rivers studies spanning analytical, empirical and numerical domains suggest that at channel-forming flows there is a tendency towards covarying bankfull bed and width undulations amongst morphologic units such as pools and riffles, whereby relatively wide areas have relatively higher minimum bed elevations and relatively narrow areas have relatively lower minimum bed elevations. The goal of this study was to determine whether minimum bed elevation and flow-dependent channel top width are organized in a partially confined, incising gravel-cobbled bed river with multiple spatial scales of anthropogenic and natural landform heterogeneity across a range of discharges. A key result is that the test river exhibited covarying oscillations of minimum bed elevation and channel top width across all flows analyzed. These covarying oscillations were found to be quasiperiodic at channel-forming flows, scaling with the length scales of bars, pools and riffles. Thus, it appears that alluvial rivers organize their topography to have quasiperiodic, shallow and wide or narrow and deep cross section geometry, even despite ongoing, centennial-scale incision. Presumably these covarying oscillations are linked to hydrogeomorphic mechanisms associated with alluvial river channel maintenance. The biggest conclusion from this study is that alluvial rivers are defined more so by variability in topography and flow than mean conditions. Broader impacts of this study are that the methods provide a framework for characterizing longitudinal and flow-dependent variability in rivers for assessing geomorphic structure and aquatic habitat in space, and if repeated, through time.

  13. Discussion on the differences between epigenetic oxidized and primary red beds

    International Nuclear Information System (INIS)

    Chen Xiaolin; Fang Xiheng; Sun Ye; Pang Yaqing; Guo Qingyin

    2008-01-01

    The red oxidation zone may be formed in the process of the interlayer oxidation. If the original gray beds formed in the moist palaeoclimatic condition and became red in oxidation, it is easy to distinguish this red oxidization zone from the original red beds. Gray sandstone sandwiched by red mudstone can be formed partially in the arid-semiarid condition. If this gray sandstone was oxidized to be red in color, almost all the strata would be red in cross section, and then it will be difficult to distinguish these red strata from the original red beds. If they are regarded as original red beds, we maybe lose the favorable opportunity to find uranium deposit. This paper presents a case study of Yaojia Formation, Upper Cretaceous in the southwestern part of Songliao Basin. Although the palaeoelimatic condition was arid-semiarid, the gray sandstones of Yaojia Formation in Qianjiadian Sag and its adjacent areas have obvious characteristics of primary depositional origin, and part of them may be formed by epigenetic reduction. The gray sandstone has formed red interlayer oxidation zone after being oxidized and it is just the red interlayer oxidation zone which controls the uranium mineralization in Qianjiadian uranium deposit. By careful contrast and analysis, identification marks of red epigenetic oxidation beds have be established, which can effectively help the distinguishing of epigenetic oxidized red beds from original red beds and extends prospecting idea. (authors)

  14. Neural Network Based Montioring and Control of Fluidized Bed.

    Energy Technology Data Exchange (ETDEWEB)

    Bodruzzaman, M.; Essawy, M.A.

    1996-04-01

    The goal of this project was to develop chaos analysis and neural network-based modeling techniques and apply them to the pressure-drop data obtained from the Fluid Bed Combustion (FBC) system (a small scale prototype model) located at the Federal Energy Technology Center (FETC)-Morgantown. The second goal was to develop neural network-based chaos control techniques and provide a suggestive prototype for possible real-time application to the FBC system. The experimental pressure data were collected from a cold FBC experimental set-up at the Morgantown Center. We have performed several analysis on these data in order to unveil their dynamical and chaotic characteristics. The phase-space attractors were constructed from the one dimensional time series data, using the time-delay embedding method, for both normal and abnormal conditions. Several identifying parameters were also computed from these attractors such as the correlation dimension, the Kolmogorov entropy, and the Lyapunov exponents. These chaotic attractor parameters can be used to discriminate between the normal and abnormal operating conditions of the FBC system. It was found that, the abnormal data has higher correlation dimension, larger Kolmogorov entropy and larger positive Lyapunov exponents as compared to the normal data. Chaotic system control using neural network based techniques were also investigated and compared to conventional chaotic system control techniques. Both types of chaotic system control techniques were applied to some typical chaotic systems such as the logistic, the Henon, and the Lorenz systems. A prototype model for real-time implementation of these techniques has been suggested to control the FBC system. These models can be implemented for real-time control in a next phase of the project after obtaining further measurements from the experimental model. After testing the control algorithms developed for the FBC model, the next step is to implement them on hardware and link them to

  15. Experimental heat transfer coefficients between a surface and fixed and fluidized beds with PCM

    OpenAIRE

    Izquierdo-Barrientos, María Asunción; Sobrino, Celia; Almendros-Ibáñez, José Antonio

    2015-01-01

    This work presents an experimental study to determine the capacity of a phase change material (PCM) in granular form to be used in fixed and bubbling fluidized beds for thermal energy storage. The experimental measurements are focused on determination of the heat transfer coefficient between a heated surface immersed in the bed and the granular PCM. The flow rate is varied to quantify its influence on the heat transfer coefficient. The PCM used is Rubitherm GR50 with a phase change tem...

  16. Gas Reactor International Cooperative Program. Interim report. Safety and licensing evaluaion of German Pebble Bed Reactor concepts

    International Nuclear Information System (INIS)

    1978-09-01

    The Pebble Bed Gas Cooled Reactor, as developed in the Federal Republic of Germany, was reviewed from a United States Safety and Licensing perspective. The primary concepts considered were the steam cycle electric generating pebble bed (HTR-K) and the process heat pebble bed (PNP), although generic consideration of the direct cycle gas turbine pebble bed (HHT) was included. The study examines potential U.S. licensing issues and offers some suggestions as to required development areas

  17. Gas Reactor International Cooperative Program. Interim report. Safety and licensing evaluaion of German Pebble Bed Reactor concepts

    Energy Technology Data Exchange (ETDEWEB)

    1978-09-01

    The Pebble Bed Gas Cooled Reactor, as developed in the Federal Republic of Germany, was reviewed from a United States Safety and Licensing perspective. The primary concepts considered were the steam cycle electric generating pebble bed (HTR-K) and the process heat pebble bed (PNP), although generic consideration of the direct cycle gas turbine pebble bed (HHT) was included. The study examines potential U.S. licensing issues and offers some suggestions as to required development areas.

  18. FLUIDIZED BED STEAM REFORMER (FBSR) PRODUCT: MONOLITH FORMATION AND CHARACTERIZATION

    Energy Technology Data Exchange (ETDEWEB)

    Jantzen, C

    2006-09-13

    The most important requirement for Hanford's low activity waste (LAW) form for shallow land disposal is the chemical durability of the product. A secondary, but still essential specification, is the compressive strength of the material with regards to the strength of the material under shallow land disposal conditions, e.g. the weight of soil overburden and potential intrusion by future generations, because the term ''near-surface disposal'' indicates disposal in the uppermost portion, or approximately the top 30 meters, of the earth's surface. The THOR{reg_sign} Treatment Technologies (TTT) mineral waste form for LAW is granular in nature because it is formed by Fluidized Bed Steam Reforming (FBSR). As a granular product it has been shown to be as durable as Hanford's LAW glass during testing with ASTM C-1285-02 known as the Product Consistency Test (PCT) and with the Single Pass Flow Through Test (SPFT). Hanford Envelope A and Envelope C simulants both performed well during PCT and SPFT testing and during subsequent performance assessment modeling. This is partially due to the high aluminosilicate content of the mineral product which provides a natural aluminosilicate buffering mechanism that inhibits leaching and is known to occur in naturally occurring aluminosilicate mineral analogs. In order for the TTT Na-Al-Si (NAS) granular mineral product to meet the compressive strength requirements (ASTM C39) for a Hanford waste form, the granular product needs to be made into a monolith or disposed of in High Integrity Containers (HIC's). Additionally, the Hanford intruder scenario for disposal in the Immobilized Low Activity Waste (ILAW) trench is mitigated as there is reduced intruder exposure when a waste form is in a monolithic form. During the preliminary testing of a monolith binder for TTT's FBSR mineral product, four parameters were monitored: (1) waste loading (not optimized for each waste form tested); (2) density

  19. A comparison of granules produced by high-shear and fluidized-bed granulation methods.

    Science.gov (United States)

    Morin, Garett; Briens, Lauren

    2014-08-01

    Placebo granules were manufactured by both wet high-shear and fluidized-bed techniques. The granules were compared based on size, shape, surface morphology, and a variety of different flowability measurements. This comparison showed that granule formation and growth were different, with induction growth for high-shear granulation and steady growth for fluidized-bed granulation. Final granules from high-shear granulation were more spherical and dense compared with the irregular granules from fluidized-bed granulation. The high-shear granules demonstrated better overall flow properties.

  20. Bed rest reduces metabolic protein content and abolishes exercise-induced mRNA responses in human skeletal muscle

    DEFF Research Database (Denmark)

    Jørgensen, Stine Ringholm; Biensø, Rasmus S; Kiilerich, Kristian

    2011-01-01

    bed rest. Research Design and Methods: Twelve young, healthy, male subjects completed 7 days of bed rest with vastus lateralis muscle biopsies taken before and after bed rest. In addition, muscle biopsies were obtained from 6 of the subjects prior to, immediately after and 3h after 45 min one...

  1. Minimum rate of spouting and peak pressure-drop in a spouted bed

    International Nuclear Information System (INIS)

    Ogino, Fumiaru; Zhang, Laiying; Maehashi, Yasuo

    1993-01-01

    Spouted beds are a type of fluidized bed, but one which has certain advantages, viz., (1) the capability of handling coarse particles; (2) the capability of handling particles with complicated shapes; (3) the absence of the need to have a high flow-rate; and (4) a small pressure drop. The first and second of these advantages, in particular, are responsible for spouted beds having found use in industry in the drying of powdered materials, in granulation apparatus, in the roasting of mineral ores, and in waste incinerators, while their application in coal gasification and shale pyrolysis is, also, examined

  2. CFD Flow and Heat Transfer Simulation for Empty and Packed Fixed Bed Reactor in Catalytic Cracking of Naphtha

    OpenAIRE

    D. Salari; A. Niaei; P. Chitsaz Yazdi; M. Derakhshani; S. R. Nabavi

    2007-01-01

    This work aims to test the application of computational fluid dynamics (CFD) modeling to fixed bed catalytic cracking reactors. Studies of CFD with a fixed bed design commonly use a regular packing with N=2 to define bed geometry. CFD allows us to obtain a more accurate view of the fluid flow and heat transfer mechanisms present in fixed bed equipment. Naphtha was used as feedstock and the reactor length was 80cm. It is divided in three sections that catalyst bed packed in the middle section ...

  3. The Effects of Long Duration Bed Rest on Brain Functional Connectivity and Sensorimotor Functioning

    Science.gov (United States)

    Cassady, K.; Koppelmans, V.; De Dios, Y.; Stepanyan, V.; Szecsy, D.; Gadd, N.; Wood, S.; Reuter-Lorenz, P.; Castenada, R. Riascos; Kofman, I.; hide

    2016-01-01

    Long duration spaceflight has been associated with detrimental alterations in human sensorimotor functioning. Prolonged exposure to a head-down tilt (HDT) position during long duration bed rest can resemble several effects of the microgravity environment such as reduced sensory inputs, body unloading and increased cephalic fluid distribution. The question of whether microgravity affects other central nervous system functions such as brain functional connectivity and its relationship with behavior is largely unknown, but of importance to the health and performance of astronauts both during and post-flight. In the present study, we investigate the effects of prolonged exposure to HDT bed rest on resting state brain functional connectivity and its association with behavioral changes in 17 male participants. To validate that our findings were not due to confounding factors such as time or task practice, we also acquired resting state functional magnetic resonance imaging (rs-fMRI) and behavioral measurements from 14 normative control participants at four time points. Bed rest participants remained in bed with their heads tilted down six degrees below their feet for 70 consecutive days. Rs-fMRI and behavioral data were obtained at seven time points averaging around: 12 and 8 days prior to bed rest; 7, 50, and 70 days during bed rest; and 8 and 12 days after bed rest. 70 days of HDT bed rest resulted in significant increases in functional connectivity during bed rest followed by a reversal of changes in the post bed rest recovery period between motor cortical and somatosensory areas of the brain. In contrast, decreases in connectivity were observed between temporoparietal regions. Furthermore, post-hoc correlation analyses revealed a significant relationship between motor-somatosensory network connectivity and standing balance performance changes; participants that exhibited the greatest increases in connectivity strength showed the least deterioration in postural

  4. A Conceptual Framework for Improving Critical Care Patient Flow and Bed Use.

    Science.gov (United States)

    Mathews, Kusum S; Long, Elisa F

    2015-06-01

    High demand for intensive care unit (ICU) services and limited bed availability have prompted hospitals to address capacity planning challenges. Simulation modeling can examine ICU bed assignment policies, accounting for patient acuity, to reduce ICU admission delays. To provide a framework for data-driven modeling of ICU patient flow, identify key measurable outcomes, and present illustrative analysis demonstrating the impact of various bed allocation scenarios on outcomes. A description of key inputs for constructing a queuing model was outlined, and an illustrative simulation model was developed to reflect current triage protocol within the medical ICU and step-down unit (SDU) at a single tertiary-care hospital. Patient acuity, arrival rate, and unit length of stay, consisting of a "service time" and "time to transfer," were estimated from 12 months of retrospective data (n = 2,710 adult patients) for 36 ICU and 15 SDU staffed beds. Patient priority was based on acuity and whether the patient originated in the emergency department. The model simulated the following hypothetical scenarios: (1) varied ICU/SDU sizes, (2) reserved ICU beds as a triage strategy, (3) lower targets for time to transfer out of the ICU, and (4) ICU expansion by up to four beds. Outcomes included ICU admission wait times and unit occupancy. With current bed allocation, simulated wait time averaged 1.13 (SD, 1.39) hours. Reallocating all SDU beds as ICU decreased overall wait times by 7.2% to 1.06 (SD, 1.39) hours and increased bed occupancy from 80 to 84%. Reserving the last available bed for acute patients reduced wait times for acute patients from 0.84 (SD, 1.12) to 0.31 (SD, 0.30) hours, but tripled subacute patients' wait times from 1.39 (SD, 1.81) to 4.27 (SD, 5.44) hours. Setting transfer times to wards for all ICU/SDU patients to 1 hour decreased wait times for incoming ICU patients, comparable to building one to two additional ICU beds. Hospital queuing and simulation modeling

  5. Fluid-bed combustion

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, G.; Schoebotham, N.

    1981-02-01

    In Energy Equipment Company's two-stage fluidized bed system, partial combustion in a fluidized bed is followed by burn-off of the generated gases above the bed. The system can be retrofitted to existing boilers, and can burn small, high ash coal efficiently. It has advantages when used as a hot gas generator for process drying. Tests on a boiler at a Cadbury Schweppes plant are reported.

  6. Agglomeration mechanism in biomass fluidized bed combustion – Reaction between potassium carbonate and silica sand

    DEFF Research Database (Denmark)

    Anicic, Bozidar; Lin, Weigang; Dam-Johansen, Kim

    2018-01-01

    Agglomeration is one of the operational problems in fluidized bed combustion of biomass, which is caused by interaction between bed materials (e.g. silica sand) and the biomass ash with a high content of potassium species. However, the contribution of different potassium species to agglomeration......CO3 and silica sand, forming a thin product layer. The layer acted as a reactive media further reacting with K2CO3 and silica sand. The results provide a basis for understanding of potassium induced agglomeration process in fluidized bed biomass combustion....

  7. Experimental study and large eddy simulation of effect of terrain slope on marginal burning in shrub fuel beds

    Science.gov (United States)

    Xiangyang Zhou; Shankar Mahalingam; David Weise

    2007-01-01

    This paper presents a combined study of laboratory scale fire spread experiments and a three-dimensional large eddy simulation (LES) to analyze the effect of terrain slope on marginal burning behavior in live chaparral shrub fuel beds. Line fire was initiated in single species fuel beds of four common chaparral plants under various fuel bed configurations and ambient...

  8. Compost en ander strooisel in ligboxen voor melkvee = Compost and other bedding material in cubicle housing for dairy cow

    NARCIS (Netherlands)

    Smolders, G.

    2012-01-01

    In 2011 cubicle housing with different bedding material were assessed with the welfare quality protocol, samples of the bedding and bulktank milk were taken to analyze heavy metals and bacteria. Skin damages were lowest in barns with lush bedding material with no real differences between boxcompost,

  9. Bioreactors with Light-Beads Fluidized Bed: The Voidage Function and its Expression

    Directory of Open Access Journals (Sweden)

    Iliev Vasil

    2014-12-01

    Full Text Available Light-beads fluidized bed bioreactors with gel particles are an attractive alternative for the implementation of a system with immobilized cells. They have a number of advantages: soft operating conditions, ability to work in an ideal mixing regime, intensification of heat- and mass transfer processes in the fermentation system. The expansion characteristics of the fluidized bed were investigated in the present work. The fluidized bed expansion was described using the voidage function. It was found that the voidage can be described by nonlinear regression relationships and the regression coefficients were a function of the particles parameters.

  10. Characteristics of Sawdust and Cocopeat Beddings, and Their Usefulness According to the Fan and Pen Location for Rearing Hanwoo Cattle.

    Science.gov (United States)

    Ahn, Gyu Chul; Jang, Sun Sik; Lee, Kang Yeon; Kwak, Wan Sup; Oh, Young Kyun; Park, Keun Kyu

    2016-03-01

    This study was designed to examine the characteristics of sawdust and cocopeat bedding materials, including physicochemical properties (Exp. I) and on-farm trial (Exp. II). In Exp. I, the proportion of particle size was in the order of sawdust> cocopeat India>cocopeat Vietnam (pcocopeat Vietnam>sawdust (pfan (blowing 2.00 m/s) and no fan treatments, and feed bunk side (FB) and water supply side (WS) within a pen (4.5 m, width×9.0 m, length). Beddings were replaced with fresh bedding materials when moisture concentrations were over 65%. No interactions among treatments were detected for moisture concentration and increment rates, and ammonia concentrations, but a significant effect was observed (pfan than with fan. Moisture concentrations and increment rate within a pen were also higher (pfan-FB and sawdust-fan-FB were replaced with fresh bedding material between 4 to 5 experimental weeks. The ammonia concentrations and pH of beddings were not significantly different among treatments. Therefore, using cocopeat bedding with a blowing fan can extend twice the bedding utilization period, and WS within a pen showed twice the bedding-life compared to FB. Despite the outstanding characteristics of cocopeat compared with sawdust, using cocopeat as an alternative for sawdust bedding is not recommended for cattle management, considering it has 4.4 times higher bedding cost and a dust production problem.

  11. Transport and storage of bed material in a gravel-bed channel during episodes of aggradation and degradation: a field and flume study

    Science.gov (United States)

    Bonnie Smith Pryor; Thomas Lisle; Diane Sutherland Montoya; Sue Hilton

    2011-01-01

    The dynamics of sediment transport capacity in gravel-bed rivers is critical to understanding the formation and preservation of fluvial landforms and formulating sediment-routing models in drainage systems. We examine transport-storage relations during cycles of aggradation and degradation by augmenting observations of three events of channel aggradation and...

  12. Design, fabrication and commissioning of motorized scanning bed mechanism for shadow shield whole body counting system

    International Nuclear Information System (INIS)

    Arun, B.; Varalakshimi, S.; Manohari, M.; Mathiyarasu, R.

    2012-01-01

    A new scanning bed mechanism for shadow shield counting system is designed, fabricated and commissioned at RSD, IGCAR. The present motorized scanning bed mechanism has varying scan speeds, state of art limit sensors, smooth bed movement, touch screen based software controlled operation parameters with UPS power back-up. In view of the improved personnel safety the entire system has been designed to operate with low voltage power supply (24V). The evaluation demonstrated that the incorporation of the new motorized scanning mechanism has not affected the counting performance of the shadow shield wholebody counting system. (author)

  13. On farm development of bedded pack dairy barns in The Netherlands : animal welfare and milk quality

    NARCIS (Netherlands)

    Ouweltjes, W.; Smolders, E.A.A.

    2014-01-01

    This report describes figures on animal health and welfare on three Dutch commercial dairy farms that house their cows in bedded pack barns. Moreover, some milk quality parameters and culling and replacement figures are reported.

  14. Water flow across and sediment trapping in submerged macrophyte beds of contrasting growth form

    NARCIS (Netherlands)

    Vermaat, J.E.; Santamaria, L.; Roos, P.J.

    2000-01-01

    Patterns of wave amplitudes, linear flow velocity, turbidity, sedimentation and periphyton accumulation were quantified across two macrophyte beds of contrasting architecture and adjacent unvegetated sediments, in Lake Veluwe, The Netherlands. Within both a Chara aspera- and an Alisma

  15. The Safety of Hospital Beds

    Science.gov (United States)

    Gervais, Pierre; Pooler, Charlotte; Merryweather, Andrew; Doig, Alexa K.; Bloswick, Donald

    2015-01-01

    To explore the safety of the standard and the low hospital bed, we report on a microanalysis of 15 patients’ ability to ingress, move about the bed, and egress. The 15 participants were purposefully selected with various disabilities. Bed conditions were randomized with side rails up or down and one low bed with side rails down. We explored the patients’ use of the side rails, bed height, ability to lift their legs onto the mattress, and ability to turn, egress, and walk back to the chair. The standard bed was too high for some participants, both for ingress and egress. Side rails were used by most participants when entering, turning in bed, and exiting. We recommend that side rails be reconsidered as a means to facilitate in-bed movement, ingress, and egress. Furthermore, single deck height settings for all patients are not optimal. Low beds as a safety measure must be re-evaluated. PMID:28462302

  16. Comparing levels of anxiety during bed and shower baths in patients with acute myocardial infarction.

    Science.gov (United States)

    Lopes, Juliana de Lima; Nogueira-Martins, Luiz Antonio; Gonçalves, Maria Aparecida Batistão; de Barros, Alba Lucia Bottura Leite

    2010-01-01

    This study compared the levels of anxiety presented by patients with acute myocardial infarction in bed and shower baths and the influence of antecedent variables: age, gender, medications, previous hospitalization and/or bed bath, patients' preference regarding the professional's gender, risk factors and anxiety-traits. This crossover study was conducted between February and August 2007 in coronary units. The sample was composed of 71 patients with acute myocardial infarction. The State-Trait Anxiety Inventory (STAI) was applied before the baths (bed and shower baths), immediately after the baths and twenty minutes after the second evaluation. Results revealed that patients were more anxious in the bed bath than in the shower in the three assessments (p <0.0001) and the only variable that interfered with state-anxiety was high blood pressure.

  17. A Comparison of Granules Produced by High-Shear and Fluidized-Bed Granulation Methods

    OpenAIRE

    Morin, Garett; Briens, Lauren

    2014-01-01

    Placebo granules were manufactured by both wet high-shear and fluidized-bed techniques. The granules were compared based on size, shape, surface morphology, and a variety of different flowability measurements. This comparison showed that granule formation and growth were different, with induction growth for high-shear granulation and steady growth for fluidized-bed granulation. Final granules from high-shear granulation were more spherical and dense compared with the irregular granules from f...

  18. Deposition of Suspended Clay to Open and Sand-Filled Framework Gravel Beds in a Laboratory Flume

    Science.gov (United States)

    Mooneyham, Christian; Strom, Kyle

    2018-01-01

    Pulses of fine sediment composed of sand, silt, and clay can be introduced to gravel bed rivers through runoff from burn-impacted hillslopes, landslides, bank failure, or the introduction of reservoir sediment as a result of sluicing or dam decommissioning. Here we present a study aimed at quantifying exchange between suspensions of clay and gravel beds. The questions that motivate the work are: how do bed roughness and pore space characteristics, shear velocity (u∗), and initial concentration (C0) affect clay deposition on or within gravel beds? Where does deposition within these beds occur, and can deposited clay be resuspended while the gravel is immobile? We examine these questions in a laboratory flume using acrylic, open-framework gravel, and armored sand-gravel beds under conditions of varying u∗ and C0. Deposition of clay occurred to all beds (even with Rouse numbers ˜ 0.01). We attribute deposition under full suspension conditions to be an outcome of localized protected zones where clay can settle and available pore space in the bed. For smooth wall cases, protection came from the viscous wall region and the development of bed forms; for the rough beds, protection came from separation zones and low-velocity pore spaces. Bed porosity was the strongest influencer of nondimensional deposition rate; deposition increased with porosity. Deposition was inversely related to u∗ for the acrylic bed runs; no influence of u∗ was found for the porous bed runs. Increases in discharge resulted in resuspension of clay from acrylic beds; no resuspension was observed in the porous bed runs.

  19. Measurements, patterns, and controls of nitrogen flux in a cranberry bed during the harvest flood

    Science.gov (United States)

    Kennedy, C. D.

    2012-12-01

    Nitrogen (N) is an essential nutrient for cranberry production but also a source of freshwater eutrophication in southeastern Massachusetts. Surface application of N fertilizer is pervasive throughout the cranberry industry, accounting for 93% of total annual N export from farms. The agricultural practice of "wet harvesting", involving the flooding of farms with ~1 ft of water, may promote the vertical transport and transformation of nitrogen in cranberry beds. A cranberry bed at the University of Massachusetts Cranberry Station (East Wareham, MA) has been instrumented with a network of hydrological monitoring equipment for quantifying patterns and controls of nitrogen dynamics during the harvest flood. Here, data of (1) hydraulic head gradient between floodwater and groundwater (J), (2) hydraulic conductivity (K), and (3) N concentration in groundwater (C) collected from multiple points on the cranberry bed will be presented, and used to evaluate the patterns and controls N fluxes (f = JKC) in the cranberry bed.

  20. Trace elements in bed sediments and aquatic invertebrates from three streams in Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence, S. [Geological Survey, Carson City, NV (United States). Water Resources Div.

    1995-12-31

    In September 1992, the US Geological Survey, as part of the National Water Quality Assessment Program, collected crayfish (Pacifastacus Ieniusculus and Procambarus clarkii), asiatic clam (Corbicula fluminea), caddis-fly larvae (Hydropsyche spp.) and bed-sediment samples from the Truckee and Carson Rivers, and Las Vegas Wash in Nevada and analyzed them for selected trace elements. This report describes and compares the concentrations of arsenic, copper, manganese, mercury, silver, and zinc in those samples. In the Truckee and Carson Rivers, concentrations of the six trace elements in aquatic invertebrate samples are similar to concentrations measured in bed sediments. In the Truckee River, concentrations of these elements in crayfish and bed-sediment samples were highest in the Reno-Sparks urban area. In the Carson River, arsenic and copper are highest in bed-sediment samples upstream of Carson City due to geothermal springs and acid-mine drainage from an abandoned sulfur mine; concentrations of manganese, mercury, silver, and zinc were highest in bed-sediment samples collected downstream of the Carson City urban area due to historic gold and silver mining, and urban runoff. The highest mercury concentration in crayfish tissue, 48 {micro}g/g dry weight, was measured in a sample from the lower Carson River. In Las Vegas Wash, bed-sediment concentrations were lower than those in the Truckee and Carson Rivers; but, trace-element concentrations in crayfish tissue tended to be higher than those in bed sediment. Samples collected during this study show that trace elements are enriched in the bed sediments of all three rivers and are bioavailable. Trace-element concentrations among samples of crayfish, asiatic clam, and caddis-fly larvae showed little similarity.

  1. Afghanistan and Pakistan Reconstruction Opportunity Zones (ROZs), H.R. 1318/H.R. 1886/H.R. 2410 and S. 496: Issues and Arguments

    Science.gov (United States)

    2009-07-09

    cotton dish towels 6,845,300 9.2 629,768 6302.91.0050 cotton woven towels 6,115,458 9.2 562,622 6302.32.2040 man-made fiber bed linens 6,072,055 11.4...more ROZs; (2) the article is yarn, thread, twine, cordage, rope, cable, or braiding, and the fibers are spun in or extruded in one or more ROZs; (3...the article is a fabric and the fibers , filaments, or yarns are woven, knitted, needled, tufted, felted, entangled, or transformed by any other

  2. Pressure drop across the distributor in fluidized beds with regular and irregular distributor design

    International Nuclear Information System (INIS)

    Ho, T.C.; Chen, T.K.; Hopper, J.R.

    1984-01-01

    The characteristics of the distributor pressure drop in a fluidized bed corresponding to perforated distributor plates with regular and irregular distributor design were studied. Distributor pressure drops were measured in an empty bed and beds with different fluidizing particles or bed heights. The design variables tested included the open area ratio, hole size, hole lay-out, plate thickness and design irregularity. The characteristics of distributor pressure drop corresponding to abnormal operating conditions, i.e., hole blocking and channeling, were also examined. The results indicate that the open area ratio is the most critical parameter governing the plate pressure drop for a regular distributor and that the design irregularity has a strong effect on the distributor behavior when particles are present. The study has given rise to a criterion for uniform air distribution across the distributor holes

  3. Original methodology and nomography tool for dimensioning multi-packed-bed dehumidifiers

    Science.gov (United States)

    Nciri, Rached; Rabhi, Kamel; Nasri, Faouzi; Ali, Chaouki; Ben Bacha, Habib

    2018-02-01

    This work deals with the dimensioning of multi-packed-bed dehumidifiers used in solar air-conditioning systems. An efficient dimensioning methodology is elaborated, explained and visualized by a chart. The proposed methodology permits to ensure an appropriate packed-bed dimensioning based on a compromise between the highest possible amount of heat and mass transfer and the lowest possible level of pressure drop within a packed-bed-dehumidifier. Nomography tool is implemented in order to simplify, speed up and expand the possibilities of dimensioning. The proposed nomographs permit to determine the appropriate values of the diameter, the porosity and the height of the packed-bed. The mathematical construction techniques of all nomographs are presented in detail. Applied examples are carried out in order to show the effectiveness of each nomograph.

  4. The development of nonwoven fabric and agricultural bed soil using kapok fiber for industrial usages

    International Nuclear Information System (INIS)

    Chung, Byung Yeoup; Kim, Jin Hong; Lee, Seung Sik

    2010-01-01

    The purpose of this project is the development of nonwoven fabric using natural kapok fiber and synthetic fiber for industrial usages and the development of manufacturing techniques for nursery bed soil using kapok fiber. Research scopes include the development of agricultural bed soil using kapok fiber and nonwoven fabric using kapok fiber. Main results are as follow; the physico-chemical characterization of kapok fiber (water holding capacity, bulk density, water retention curve, viscoelastic measurement, oil adsorption capacity, analysis of essential elements, measurement of anion and cation); the physico-chemical characterization of kapok bed soil; the evidence experiment of kapok bed soil; the optimum content of kapok fiber and synthetic fiber for nonwoven fabric; establishment of the optimum radiation dose for manufacturing kapok nonwoven fabric

  5. Palynology, paleoclimatology and correlation of middle Miocene beds from Porcupine River (locality 90-1), Alaska

    Science.gov (United States)

    White, J.M.; Ager, T.A.

    1994-01-01

    Beds in the Upper Ramparts Canyon of the Porcupine River, Alaska (67?? 20' N, 141?? 20' W), yielded a flora rich in pollen of hardwood genera now found in the temperate climates of North America and Asia. The beds are overlain or enclosed by two basalt flows which were dated to 15.2 ?? 0.1 Ma by the 40Ar 39Ar method, fixing the period of the greatest abundance of warm-loving genera to the early part of the middle Miocene. The assemblage is the most northern middle Miocene flora known in Alaska. Organic bed 1 underlies the basalt and is older than 15.2 Ma, but is of early to middle Miocene age. The pollen assemblage from organic bed 1 is dominated by conifer pollen from the pine and redwood-cypress-yew families with rare occurrences of temperate hardwoods. Organic bed 2 is a forest floor containing redwood trees in life position, engulfed by the lowest basalt flow. A pine log has growth rings up to 1 cm thick. Organic beds 3 and 4 comprise lacustrine sediment and peat between the two basalt flows. Their palynoflora contain conifers and hardwood genera, of which about 40% have modern temperate climatic affinities. Hickory, katsura, walnut, sweet gum, wingnut, basswood and elm pollen are consistently present, and beech and oak alone make up about 20% of the pollen assemblage. A warm high latitude climate is indicated for all of the organic beds, but organic bed 3 was deposited under a time of peak warmth. Climate data derived by comparison with modern east Asian vegetation suggest that, at the time of deposition of organic bed 3, the Mean Annual Temperature (MAT) was ca. 9??C, the Warm Month Mean Temperature (WMMT) was ??? 20??C and the Cold Month Mean Temperature (CMMT) was ca. -2??C. In contrast, the modern MAT for the region is -8.6??C, WMMT is 12.6??C and CMMT is -28??C. Organic beds 3 and 4 correlate to rocks of the middle Miocene-late Seldovian Stage of Cook Inlet and also probably correlate to, and more precisely date, the lower third of the Suntrana Formation

  6. Exploratory study of bed-sharing and maternal-infant bonding.

    Science.gov (United States)

    Mitchell, Edwin A; Hutchison, B Lynne; Thompson, John Md; Wouldes, Trecia A

    2015-08-01

    Bed-sharing with an infant is controversial due to the increased risk of sudden unexpected death in infancy versus postulated benefits of the practice such as enhanced breastfeeding and maternal-infant bonding. This study evaluated the association between bed-sharing and maternal-infant bonding. Four hundred randomly selected mothers who had delivered in a large maternity unit in Auckland and whose infants were between the ages of 6 weeks and 4 months were sent a postal questionnaire asking about their bed-sharing practices last night, usually, and in the last 2 weeks. Included in the questionnaire were factors 1 and 2 questions from the Postpartum Bonding Questionnaire to assess maternal-infant bonding. Responders totalled 172 (43%), and infants were a mean age of 11 weeks. Fourteen per cent of infants slept in a bed-sharing situation last night, 8% usually, and 41% had slept with an adult in the last 2 weeks. Nine per cent of mothers scored above the cut-off for factor 1 for impaired maternal-infant bonding. Infants of these mothers were more likely to bed-share last night, usually, and in the last 2 weeks, and were less likely to use a pacifier and to breastfeed. Bed-sharing mothers scored more highly on individual questions relating to being annoyed or irritated by their baby. There is an inverse association between bed-sharing and maternal-infant bonding, which is contrary to the often expressed belief that bed-sharing enhances maternal-infant bonding. © 2015 The Authors. Journal of Paediatrics and Child Health © 2015 Paediatrics and Child Health Division (Royal Australasian College of Physicians).

  7. [Understanding the gap between practice and the technical-scientific evolution of the bed-bath].

    Science.gov (United States)

    Maciel, Silaine Sandrini Alves; Bocchi, Silvia Cristina Mangini

    2006-01-01

    The objectives of this qualitative study were to understand the experience of the nursing dependent person for the bed-bath and develop a theoretical model of this experience. The Symbolic Interactionism perspective and Grounded Theory methodology were used to develop the study. Observation and interview were the strategies used for data collection. Based on data analysis, a phenomenon was identified: learning to assess life and nursing when the patient becomes dependent on nursing care for the bed-bath. The theoretical model shows the meaning of the patient experience in the bed-bath, integrated by the core category--proposing a nursing model for the bed-bath according to the patient assessment process, as opposed to the technical-scientific evolution of this procedure.

  8. Effects of exercise on fluid exchange and body composition in man during 14-day bed rest

    Science.gov (United States)

    Greenleaf, J. E.; Bernauer, E. M.; Juhos, L. T.; Young, H. L.; Morse, J. T.; Staley, R. W.

    1977-01-01

    A description is presented of an investigation in which body composition, fluid intake, and fluid and electrolyte losses were measured in seven normal, healthy men during three 2-wk bed-rest periods, separated by two 3-wk recovery periods. During bed rest the subjects remained in the horizontal position continuously. During the dietary control periods, body mass decreased significantly with all three regimens, including no exercise, isometric exercise, and isotonic excercise. During bed rest, body mass was essentially unchanged with no exercise, but decreased significantly with isotonic and isometric exercise. With one exception, there were no statistically significant changes in body density, lean body mass, or body fat content by the end of each of the three bed-rest periods.

  9. Vitamin D: Findings from Antarctic, Bed Rest, Houston, and ISS

    Science.gov (United States)

    Zwart, Sara R.; Locke, J.; Pierson, D.; Mehta, S.; Bourbeau, Y.; Parsons, H.; Smith, S. M.

    2009-01-01

    Obtaining vitamin D is critical for space travelers because they lack ultraviolet light exposure and have an insufficient dietary supply of vitamin D. Despite the provision of 400 IU vitamin D supplements to International Space Station (ISS) early crewmembers, vitamin D status was consistently lower after flight than before flight, and in several crewmembers has decreased to levels considered clinically significant. Vitamin D has long been known to play a role in calcium metabolism, and more recently its non-calcitropic functions have been recognized. According to the results of several recent studies, functionally relevant measures indicate that the lower limit of serum 25-hydroxyvitamin D (a marker of vitamin D status) should be raised from the current 23 nmol/L to 80 nmol/L. The mean preflight serum 25-hydroxyvitamin D (25-OH vit D) for U.S. ISS crewmembers to date is 63 +/- 16 nmol/L, and after a 4- to 6-mo space flight it typically decreases 25-30% despite supplementation (400 IU/d). The sub-optimal pre- and postflight vitamin D status is an issue that needs to be addressed, to allow NASA to better define the appropriate amount of supplemental vitamin D to serve as a countermeasure against vitamin D deficiency in astronaut crews. A series of ground-based and flight studies in multiple models have been conducted, including Antarctica in winter months when UV-B radiation levels are essentially zero, bed rest where subjects are not exposed to UV-B radiation for 60-90 days, in free-living individuals in Houston, and in International Space Station crewmembers. In these studies, we looked at dose regimen and efficacy, compliance issues, as well as toxicity. Preliminary results from these studies will be presented. Together, the data from these studies will enable us to provide space crews with evidence-based recommendations for vitamin D supplementation. The findings also have implications for other persons with limited UV light exposure, including polar workers and

  10. Heat- and mass-transfer effect in slurry-bed Fischer-Tropsch reactors

    Science.gov (United States)

    Heinemann, H.; Bell, A. T.; Stern, D. A.

    1982-02-01

    One of the advantages claimed for slurry bed reactors is the ability to operate at lower hydrogen to carbon monoxide ratios than either the fixed bed or fluid bed. Reasons for this difference were not previously fully established. Two factors may contribute to the ability of the slurry reactor to tolerate lower hydrogen/CO ratios. These are greater isothermicity, and mass transfer effects on the gas liquid interface in the slurry reactor. Work with small diameter fixed bed reactors has shown that there is a critical temperature at which plugging of the reactors using an iron catalyst will occur. The exact temperature is a function of both the hydrogen/CO ratio and the space velocity. A difference of 10 to 15 C separates operability from non-operability. It is therefore likely that in the critical temperature range around 300 C hot spots on the catalysts may be the cause of plugging and deactivation at low hydrogen/CO ratios.

  11. Sodium and steam leak simulation studies for fluidized bed steam generators

    International Nuclear Information System (INIS)

    Keeton, A.R.; Vaux, W.G.; Lee, P.K.; Witkowski, R.E.

    1976-01-01

    An experimental program is described which was conducted to study the effects of sodium or steam leaking into an operating fluidized bed of metal or ceramic particles at 680 to 800 0 K. This effort was part of the early development studies for a fluidized-bed steam generator concept using helium as the fluidizing gas. Test results indicated that steam and small sodium leaks had no effect on the quality of fluidization, heat transfer coefficient, temperature distribution, or fluidizing gas pressure drop across the bed. Large sodium leaks, however, immediately upset the operation of the fluidized bed. Both steam and sodium leaks were detected positively and rapidly at an early stage of a leak by instruments specifically selected to accomplish this

  12. DNA binding during expanded bed adsorption and factors affecting adsorbent aggregation

    DEFF Research Database (Denmark)

    Arpanaei, Ayyoob; Mathiasen, N.; Hobley, Timothy John

    2008-01-01

    DNA-induced aggregation and contraction of expanded bed adsorption chromatography beds have been examined using strong anion exchanger Q HyperZ and calf thymus DNA in buffers containing added NaCl. Two batches of adsorbent with different ionic capacities were used allowing the effects of different...... tolerance of anion exchangers when binding DNA. However, more importantly. with the adsorbents examined here. attempts to reduce bed aggregation by feedstock conditioning with added salt may increase DNA binding leading to a reduction in expanded bed adsorption performance compromising protein capture...... ligand densities to be examined. Very high dynamic binding capacities at 10% breakthrough were found in the absence of added salt. However, the highest binding capacities (similar to 10 and similar to 19mg DNA ml(-1) gel) were found in buffers containing added salt at concentrations of either 0.25 or 0...

  13. Elementary theory of bed-sediment entrainment by debris flows and avalanches

    Science.gov (United States)

    Iverson, Richard M.

    2012-01-01

    Analyses of mass and momentum exchange between a debris flow or avalanche and an underlying sediment layer aid interpretations and predictions of bed-sediment entrainment rates. A preliminary analysis assesses the behavior of a Coulomb slide block that entrains bed material as it descends a uniform slope. The analysis demonstrates that the block's momentum can grow unstably, even in the presence of limited entrainment efficiency. A more-detailed, depth-integrated continuum analysis of interacting, deformable bodies identifies mechanical controls on entrainment efficiency, and shows that entrainment rates satisfy a jump condition that involves shear-traction and velocity discontinuities at the flow-bed boundary. Explicit predictions of the entrainment rateEresult from making reasonable assumptions about flow velocity profiles and boundary shear tractions. For Coulomb-friction tractions, predicted entrainment rates are sensitive to pore fluid pressures that develop in bed sediment as it is overridden. In the simplest scenario the bed sediment liquefies completely, and the entrainment-rate equation reduces toE = 2μ1gh1 cos θ(1 − λ1)/ , where θ is the slope angle, μ1 is the flow's Coulomb friction coefficient, h1 is its thickness, λ1 is its degree of liquefaction, and is its depth-averaged velocity. For values ofλ1ranging from 0.5 to 0.8, this equation predicts entrainment rates consistent with rates of 0.05 to 0.1 m/s measured in large-scale debris-flow experiments in which wet sediment beds liquefied almost completely. The propensity for bed liquefaction depends on several factors, including sediment porosity, permeability, and thickness, and rates of compression and shear deformation that occur when beds are overridden.

  14. Mounted Smartphones as Measurement and Control Platforms for Motor-Based Laboratory Test-Beds

    Science.gov (United States)

    Frank, Jared A.; Brill, Anthony; Kapila, Vikram

    2016-01-01

    Laboratory education in science and engineering often entails the use of test-beds equipped with costly peripherals for sensing, acquisition, storage, processing, and control of physical behavior. However, costly peripherals are no longer necessary to obtain precise measurements and achieve stable feedback control of test-beds. With smartphones performing diverse sensing and processing tasks, this study examines the feasibility of mounting smartphones directly to test-beds to exploit their embedded hardware and software in the measurement and control of the test-beds. This approach is a first step towards replacing laboratory-grade peripherals with more compact and affordable smartphone-based platforms, whose interactive user interfaces can engender wider participation and engagement from learners. Demonstrative cases are presented in which the sensing, computation, control, and user interaction with three motor-based test-beds are handled by a mounted smartphone. Results of experiments and simulations are used to validate the feasibility of mounted smartphones as measurement and feedback control platforms for motor-based laboratory test-beds, report the measurement precision and closed-loop performance achieved with such platforms, and address challenges in the development of platforms to maintain system stability. PMID:27556464

  15. Mounted Smartphones as Measurement and Control Platforms for Motor-Based Laboratory Test-Beds

    Directory of Open Access Journals (Sweden)

    Jared A. Frank

    2016-08-01

    Full Text Available Laboratory education in science and engineering often entails the use of test-beds equipped with costly peripherals for sensing, acquisition, storage, processing, and control of physical behavior. However, costly peripherals are no longer necessary to obtain precise measurements and achieve stable feedback control of test-beds. With smartphones performing diverse sensing and processing tasks, this study examines the feasibility of mounting smartphones directly to test-beds to exploit their embedded hardware and software in the measurement and control of the test-beds. This approach is a first step towards replacing laboratory-grade peripherals with more compact and affordable smartphone-based platforms, whose interactive user interfaces can engender wider participation and engagement from learners. Demonstrative cases are presented in which the sensing, computation, control, and user interaction with three motor-based test-beds are handled by a mounted smartphone. Results of experiments and simulations are used to validate the feasibility of mounted smartphones as measurement and feedback control platforms for motor-based laboratory test-beds, report the measurement precision and closed-loop performance achieved with such platforms, and address challenges in the development of platforms to maintain system stability.

  16. Critical bed shear stress and threshold of motion of maerl biogenic gravel

    Science.gov (United States)

    Joshi, Siddhi; Duffy, Garret Patrick; Brown, Colin

    2017-07-01

    A determination of the critical bed shear stress of maerl is a prerequisite for quantifying its mobility, rate of erosion and deposition in conservation management. The critical bed shear stress for incipient motion has been determined for the first time for samples from biogenic free-living maerl beds in three contrasting environments (open marine, intertidal and beach) in Galway Bay, west of Ireland. The bed shear stress was determined using two methods, Law of the Wall and Turbulent Kinetic Energy, in a rotating annular flume and in a linear flume. The velocity profile of flowing water above a bed of natural maerl grains was measured in four runs of progressively increasing flow velocity until the flow exceeded the critical shear stress of grains on the bed. The critical Shields parameter and the mobility number are estimated and compared with the equivalent curves for natural quartz sand. The critical Shields parameters for the maerl particles from all three environments fall below the Shields curve. Along with a previously reported correlation between maerl grain shape and settling velocity, these results suggest that the highly irregular shapes also allow maerl grains to be mobilised more easily than quartz grains with the same sieve diameter. The intertidal beds with the roughest particles exhibit the greatest critical shear stress because the particle thalli interlock and resist entrainment. In samples with a high percentage of maerl and low percentage of siliciclastic sand, the lower density, lower settling velocity and lower critical bed shear stress of maerl results in its preferential transport over the siliciclastic sediment. At velocities ∼10 cm s-1 higher than the threshold velocity of grain motion, rarely-documented subaqueous maerl dunes formed in the annular flume.

  17. Experiment and modeling of low-concentration methane catalytic combustion in a fluidized bed reactor

    International Nuclear Information System (INIS)

    Yang, Zhongqing; Yang, Peng; Zhang, Li; Guo, Mingnv; Ran, Jingyu

    2016-01-01

    Highlights: • The catalytic combustion of 0.15~3 vol. % low concentration methane in a fluidized bed was studied. • A mathematical model was proposed on the basis of gas–solid flow theory. • A comparative analysis of the established model with plug flow, mixed flow and K-L models was carried out. • The axial methane profile along fluidized bed was predicted by using the mathematical model. • The bed temperature has greater impact on methane conversion than fluidized velocity. - Abstract: This study undertakes a theoretical analysis and an experimental investigation into the characteristics of low-concentration methane catalytic combustion in a bubbling fluidized bed reactor using 0.5 wt.% Pd/Al 2 O 3 as catalytic particles. A mathematical model is established based on gas–solid flow theory and is used to study the effects of bed temperature and fluidized velocity on methane catalytic combustion, and predict the dimensionless methane concentration axial profile in reactor. It is shown that methane conversion increases with bed temperature, but decreases with increasing fluidized velocity. These theoretical results are found to correlate well with the experimental measurement, with a deviation within 5%. A comparative analysis of the developed model with plug flow, mixed flow and K-L models is also carried out, and this further verifies that the established model better reflects the characteristics of low-concentration methane catalytic combustion in a bubbling fluidized bed. Using this reaction model, it was found that the difference in methane conversion between dense and freeboard zones gradually increases with bed temperature; the dense zone reaction levels off at 650 °C, thereby minimizing the difference between the dense and freeboard regions to around 15%. With an increase in bed temperature, the dimensionless methane concentration in the dense zone decreases exponentially, while in the splash zone, it varies from an exponential decay to a

  18. Computational and experimental prediction of dust production in pebble bed reactors, Part II

    Energy Technology Data Exchange (ETDEWEB)

    Hiruta, Mie; Johnson, Gannon [Department of Mechanical Engineering, University of Idaho, 1776 Science Center Drive, Idaho Falls, ID 83401 (United States); Rostamian, Maziar, E-mail: mrostamian@asme.org [Department of Mechanical Engineering, University of Idaho, 1776 Science Center Drive, Idaho Falls, ID 83401 (United States); Potirniche, Gabriel P. [Department of Mechanical Engineering, University of Idaho, 1776 Science Center Drive, Idaho Falls, ID 83401 (United States); Ougouag, Abderrafi M. [Idaho National Laboratory, 2525 N Fremont Avenue, Idaho Falls, ID 83401 (United States); Bertino, Massimo; Franzel, Louis [Department of Physics, Virginia Commonwealth University, Richmond, VA 23284 (United States); Tokuhiro, Akira [Department of Mechanical Engineering, University of Idaho, 1776 Science Center Drive, Idaho Falls, ID 83401 (United States)

    2013-10-15

    Highlights: • Custom-built high temperature, high pressure tribometer is designed. • Two different wear phenomena at high temperatures are observed. • Experimental wear results for graphite are presented. • The graphite wear dust production in a typical Pebble Bed Reactor is predicted. -- Abstract: This paper is the continuation of Part I, which describes the high temperature and high pressure helium environment wear tests of graphite–graphite in frictional contact. In the present work, it has been attempted to simulate a Pebble Bed Reactor core environment as compared to Part I. The experimental apparatus, which is a custom-designed tribometer, is capable of performing wear tests at PBR relevant higher temperatures and pressures under a helium environment. This environment facilitates prediction of wear mass loss of graphite as dust particulates from the pebble bed. The experimental results of high temperature helium environment are used to anticipate the amount of wear mass produced in a pebble bed nuclear reactor.

  19. Pellet bed reactor for nuclear propelled vehicles: Part 2: Missions and vehicle integration trades

    Science.gov (United States)

    Haloulakos, V. E.

    1991-01-01

    Mission and vehicle integration tradeoffs involving the use of the pellet bed reactor (PBR) for nuclear powered vehicles is discussed, with much of the information being given in viewgraph form. Information is given on propellant tank geometries, shield weight requirements for conventional tank configurations, effective specific impulse, radiation mapping, radiation dose rate after shutdown, space transfer vehicle design data, a Mars mission summary, sample pellet bed nuclear orbit transfer vehicle mass breakdown, and payload fraction vs. velocity increment.

  20. Sea otters homogenize mussel beds and reduce habitat provisioning in a rocky intertidal ecosystem.

    Directory of Open Access Journals (Sweden)

    Gerald G Singh

    Full Text Available Sea otters (Enhydra lutris are keystone predators that consume a variety of benthic invertebrates, including the intertidal mussel, Mytilus californianus. By virtue of their competitive dominance, large size, and longevity, M. californianus are ecosystem engineers that form structurally complex beds that provide habitat for diverse invertebrate communities. We investigated whether otters affect mussel bed characteristics (i.e. mussel length distributions, mussel bed depth, and biomass and associated community structure (i.e. biomass, alpha and beta diversity by comparing four regions that varied in their histories of sea otter occupancy on the west coast of British Columbia and northern Washington. Mussel bed depth and average mussel lengths were 1.5 times lower in regions occupied by otters for >20 years than those occupied for <5 yrs. Diversity of mussel bed associated communities did not differ between regions; however, the total biomass of species associated with mussel beds was more than three-times higher where sea otters were absent. We examined alternative explanations for differences in mussel bed community structure, including among-region variation in oceanographic conditions and abundance of the predatory sea star Pisaster ochraceus. We cannot discount multiple drivers shaping mussel beds, but our findings indicate the sea otters are an important one. We conclude that, similar to their effects on subtidal benthic invertebrates, sea otters reduce the size distributions of intertidal mussels and, thereby, habitat available to support associated communities. Our study indicates that by reducing populations of habitat-providing intertidal mussels, sea otters may have substantial indirect effects on associated communities.

  1. Using technology for bed management in public hospitals - A strategic analysis and change management plan

    OpenAIRE

    Brayan, Daniel Joseph

    2005-01-01

    As healthcare organisations in New South Wales, Australia, are facing the increased demands of an aging population, new approaches to improving access to services are being sought. This project explores the potential of applying information technology to the management of beds in a large Sydney public hospital. More specifically, this project addresses the cultural and organizational aspects of hospital environments and factors them into a change management plan for implementing bed managemen...

  2. Development of a Torque Sensor-Based Test Bed for Attitude Control System Verification and Validation

    Science.gov (United States)

    2017-12-30

    AFRL-RV-PS- AFRL-RV-PS- TR-2018-0008 TR-2018-0008 DEVELOPMENT OF A TORQUE SENSOR - BASED TEST BED FOR ATTITUDE CONTROL SYSTEM VERIFICATION AND... Sensor -Based Test Bed for Attitude Control System Verification & Validation 5a. CONTRACT NUMBER FA9453-15-1-0315 5b. GRANT NUMBER 5c. PROGRAM ELEMENT...covers the development of a torque sensor for verification and validation (V&V) of spacecraft attitude control actuators. The developed sensor directly

  3. Errors in 'BED'-derived estimates of HIV incidence will vary by place, time and age.

    Directory of Open Access Journals (Sweden)

    Timothy B Hallett

    2009-05-01

    Full Text Available The BED Capture Enzyme Immunoassay, believed to distinguish recent HIV infections, is being used to estimate HIV incidence, although an important property of the test--how specificity changes with time since infection--has not been not measured.We construct hypothetical scenarios for the performance of BED test, consistent with current knowledge, and explore how this could influence errors in BED estimates of incidence using a mathematical model of six African countries. The model is also used to determine the conditions and the sample sizes required for the BED test to reliably detect trends in HIV incidence.If the chance of misclassification by BED increases with time since infection, the overall proportion of individuals misclassified could vary widely between countries, over time, and across age-groups, in a manner determined by the historic course of the epidemic and the age-pattern of incidence. Under some circumstances, changes in BED estimates over time can approximately track actual changes in incidence, but large sample sizes (50,000+ will be required for recorded changes to be statistically significant.The relationship between BED test specificity and time since infection has not been fully measured, but, if it decreases, errors in estimates of incidence could vary by place, time and age-group. This means that post-assay adjustment procedures using parameters from different populations or at different times may not be valid. Further research is urgently needed into the properties of the BED test, and the rate of misclassification in a wide range of populations.

  4. Bed and shower baths: comparing the perceptions of patients with acute myocardial infarction.

    Science.gov (United States)

    Lopes, Juliana L; Nogueira-Martins, Luiz A; de Barros, Alba Lbl

    2013-03-01

    To compare the perceptions of patients with acute myocardial infarction concerning bed and shower baths and evaluate how antecedent variables influence their perceptions. Professionals are often oblivious to the fact that, when performing a bed bath, they are manipulating someone else's body and invading someone's privacy and intimacy. This lack of awareness may trigger various responses in patients, such as dissatisfaction and anxiety. Several studies assessing the perceptions of patients when receiving a bed bath, and most are qualitative. Thus, there is a need to quantify these perceptions. The research was a crossover study. The sample consisted of 71 patients with acute myocardial infarction, admitted to coronary units. Patients were evaluated on two occasions: after their second bed bath and after their second shower bath. A Semantic Differential Scale was constructed and validated prior to data collection. The perception of patients receiving shower baths was significantly more positive than those of patients receiving bed baths (shower baths, than those who were hospitalised for the first time. The perceptions of patients receiving bed baths were less positive than those of patients receiving shower baths. The perceptions of patients receiving baths are very important to guiding nursing care and developing strategies to minimise patient dissatisfaction. © 2012 Blackwell Publishing Ltd.

  5. Penrose's law revisited: the relationship between mental institution beds, prison population and crime rate.

    Science.gov (United States)

    Hartvig, Pål; Kjelsberg, Ellen

    2009-01-01

    In 1939, Lionel Penrose published a cross-sectional study from 18 European countries, including the Nordic, in which he demonstrated an inverse relationship between the number of mental hospital beds and the number of prisoners. He also found strong negative correlations between the number of mental hospital beds and the number of deaths attributed to murder. He argued that by increasing the number of mental institution beds, a society could reduce serious crimes and imprisonment rates. The aim of the study was to test Penrose's theories longitudinally by monitoring the capacity of all psychiatric institutions and prisons in a society over time. From official statistics, we collected and systematized all relevant information regarding the number of mental institution beds and prisoners in Norway during the years 1930-2004, along with major crime statistics for the same period. During the years 1930-59, there was a 2% population-adjusted increase in mental institution beds and a 30% decrease in the prison population. During 1960-2004, there was a 74% population-adjusted decrease in mental institution beds and a 52% increase in the prison population. The same period saw a 500% increase in overall crime and a 900% increase in violent crimes, with a concurrent 94% increase in the size of the country's police force. Penrose's law proved remarkably robust in the longitudinal perspective. As opposed to Penrose, however, we argue that the rise in crime rates only to a very limited extent can be attributed to mental health de-institutionalization.

  6. Overview and evolution of the LeRC PMAD DC test bed

    Science.gov (United States)

    Soeder, James F.; Frye, Robert J.

    1992-01-01

    Since the beginning of the Space Station Freedom Program (SSFP), the Lewis Research Center (LeRC) has been developed electrical power system test beds to support the overall design effort. Through this time, the SSFP has changed the design baseline numerous times, however, the test bed effort has endeavored to track these changes. Beginning in August 1989 with the baseline and an all DC system, a test bed was developed to support the design baseline. The LeRC power measurement and distribution (PMAD) DC test bed and the changes in the restructure are described. The changes included the size reduction of primary power channel and various power processing elements. A substantial reduction was also made in the amount of flight software with the subsequent migration of these functions to ground control centers. The impact of these changes on the design of the power hardware, the controller algorithms, the control software, and a description of their current status is presented. An overview of the testing using the test bed is described, which includes investigation of stability and source impedance, primary and secondary fault protection, and performance of a rotary utility transfer device. Finally, information is presented on the evolution of the test bed to support the verification and operational phases of the SSFP in light of these restructure scrubs.

  7. Petechiae: reproducible pattern of distribution and increased appearance after bed rest.

    Science.gov (United States)

    Ganse, Bergita; Limper, Ulrich; Bühlmeier, Judith; Rittweger, Jörn

    2013-08-01

    Exposure to acceleration can cause petechial hemorrhages, called G measles. Petechiae usually start to develop between 5 and 9 G with a high interindividual variance. Centrifuge training delays the onset to higher G levels. One might expect onset at lower G levels after bed rest; however, there is no evidence in the literature. A case of petechiae formation after bed rest is presented here. Orthostatic tolerance was tested using a tilt table and lower body negative pressure before and after bed rest in both campaigns of a 2 x 21-d bed rest study with 6 degrees head-down tilt. A 42-yr-old male Caucasian without any history of thrombosis, venous disease, hemorrhage, or petechiae, and with a negative thrombophilia screening, took part in the bed rest study as 1 out of 10 subjects. He was the only one to develop petechiae during the orthostatic tests after, but not before, bed rest in both campaigns. Petechiae were distributed throughout the lower legs and most pronounced at the shin in a stocking-like fashion, surprisingly reoccurring in an identical pattern of distribution. Petechiae appeared slowly over minutes during hyperemia. This case indicates that prolonged bed rest decreases the threshold for petechiae formation. A reproducible distribution pattern suggests that factors predisposing to petechiae formation keep their local distribution over time (possibly due to local vessel structures). Mechanisms of adaptation and interindividual variance are unclear. Findings are of clinical relevance as such cases might occur after prolonged bed rest in patients without need of expensive testing.

  8. Is parent-child bed-sharing a risk for wheezing and asthma in early childhood?

    Science.gov (United States)

    Luijk, Maartje P C M; Sonnenschein-van der Voort, Agnes M M; Mileva-Seitz, Viara R; Jansen, Pauline W; Verhulst, Frank C; Hofman, Albert; Jaddoe, Vincent W V; de Jongste, Johan C; van IJzendoorn, Marinus H; Duijts, Liesbeth; Tiemeier, Henning

    2015-03-01

    Household crowding can place young children at risk for respiratory infections which subsequently provoke asthma symptoms. However, crowding might also protect against asthma, in accordance with the hygiene hypothesis. We tested if parent-infant bed-sharing, an important dimension of household crowding, increases or decreases the risk for asthma. In a population-based prospective cohort (N = 6160) we assessed bed-sharing at 2 and 24 months; wheezing between 1 and 6 years of age; and asthma at 6 years of age. Generalised estimating equation models were used to assess repeated measures of wheezing and asthma. We found no association between bed-sharing in early infancy and wheezing or diagnosis of asthma. By contrast, we found a positive association between bed-sharing in toddlerhood and both wheezing (OR 1.42, 95% CI 1.15-1.74) and asthma (OR 1.57, 95% CI 1.03-2.38). Wheezing was not associated with bed-sharing when using cross-lagged modelling. This study suggests that bed-sharing in toddlerhood is associated with an increased risk of asthma at later ages, and not vice versa. Further studies are needed to explore the underlying causal mechanisms. Copyright ©ERS 2015.

  9. Simulation of energetic- and exergetic performance of microwave-assisted fluidized bed drying of soybeans

    International Nuclear Information System (INIS)

    Ranjbaran, M.; Zare, D.

    2013-01-01

    The performance of microwave-assisted fluidized bed drying of soybeans was simulated (using a previously validated mathematical model) and analyzed based on the first- and second law of thermodynamics. The energy and exergy analysis were carried out for several drying conditions. The effects of inlet air temperature, microwave power density, bed thickness and inlet air velocity on the efficiencies and inefficiencies of drying process have been simulated and discussed. Generally, application of microwave energy during fluidized bed drying enhanced the exergy efficiency of drying process. However, the results showed that it was more efficient not to apply microwave energy at the first stage of fluidized bed drying process. The application of higher levels of drying air temperature led in higher exergy efficiencies. The values of mean relative deviations for the predictions of efficiencies and inefficiencies of drying process were less than 14%, compared with those calculated using experimental data. - Highlights: • Introducing a mathematical model to predict the efficiency of microwave-assisted fluidized bed dryers. • Energy and exergy analysis in microwave-assisted fluidized bed drying of grains. • Providing practical recommendations for efficient use of microwave power during drying

  10. Experimental and Numerical Investigation of Four- Phase Flow (Water–Gasoline-Air-Solid in a Fluidized Bed Column

    Directory of Open Access Journals (Sweden)

    Riyadh S. Al-Turaihi

    2016-03-01

    Full Text Available In this paper four phase fluidized bed is experimentally built and numerically modeled to study the bed characteristics such as ratio (the static bed height of solid particle / the bed diameter (H/D, air, gasoline , and water superficial velocity. The test pipe for the experimental rig is Perspex pipe with 1 m long and 0.0254 m diameter. The 2D numerical model has been established with Ansys fluent 15.0. Pressure drop equation is found to relate the pressure drop with the bed parameters with deviation of 22%. The Four-phases was represented by air, water, gasoline and solid particle. The results show that the pressure of the bed increases as the ratio H/D increases and air, gasoline , and water superficial velocity increases. As well as the expansion of the bed increases as air, gasoline, and water superficial velocity increases.

  11. Simulation of biomass-steam gasification in fluidized bed reactors: Model setup, comparisons and preliminary predictions.

    Science.gov (United States)

    Yan, Linbo; Lim, C Jim; Yue, Guangxi; He, Boshu; Grace, John R

    2016-12-01

    A user-defined solver integrating the solid-gas surface reactions and the multi-phase particle-in-cell (MP-PIC) approach is built based on the OpenFOAM software. The solver is tested against experiments. Then, biomass-steam gasification in a dual fluidized bed (DFB) gasifier is preliminarily predicted. It is found that the predictions agree well with the experimental results. The bed material circulation loop in the DFB can form automatically and the bed height is about 1m. The voidage gradually increases along the height of the bed zone in the bubbling fluidized bed (BFB) of the DFB. The U-bend and cyclone can separate the syngas in the BFB and the flue gas in the circulating fluidized bed. The concentration of the gasification products is relatively higher in the conical transition section, and the dry and nitrogen-free syngas at the BFB outlet is predicted to be composed of 55% H 2 , 20% CO, 20% CO 2 and 5% CH 4 . Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Geologic and physiographic controls on bed-material yield, transport, and channel morphology for alluvial and bedrock rivers, western Oregon

    Science.gov (United States)

    O'Connor, James E.; Mangano, Joseph F.; Anderson, Scott A.; Wallick, J. Rose; Jones, Krista L.; Keith, Mackenzie K.

    2014-01-01

    The rivers of western Oregon have diverse forms and characteristics, with channel substrates ranging from continuous alluvial gravel to bare bedrock. Analysis of several measurable morphologic attributes of 24 valley reaches on 17 rivers provides a basis for comparing nonalluvial and alluvial channels. Key differences are that alluvial reaches have greater bar area, greater migration rates, and show systematic correlation among variables relating grain size to bed-material transport capacity. We relate these differences between channel types to bed-material transport rates as derived from a coupled regional analysis of empirical sediment yield measurements and physical experiments of clast attrition during transport. This sediment supply analysis shows that overall bed-material transport rates for western Oregon are chiefly controlled by (1) lithology and basin slope, which are the key factors for bed-material supply into the stream network, and (2) lithologic control of bed-material attrition from in-transport abrasion and disintegration. This bed-material comminution strongly affects bed-material transport in the study area, reducing transport rates by 50%–90% along the length of the larger rivers in the study area. A comparison of the bed-material transport estimates with the morphologic analyses shows that alluvial gravel-bed channels have systematic and bounding relations between bed-material transport rate and attributes such as bar area and local transport capacity. By contrast, few such relations are evident for nonalluvial rivers with bedrock or mixed-bed substrates, which are apparently more influenced by local controls on channel geometry and sediment supply. At the scale of western Oregon, the physiographic and lithologic controls on the balance between bed-material supply and transport capacity exert far-reaching influence on the distribution of alluvial and nonalluvial channels and their consequently distinctive morphologies and behaviors

  13. Bed load size distribution and flow conditions in a high mountain catchment of Central Pyrenees

    OpenAIRE

    Martínez Castroviejo, Ricardo

    1990-01-01

    The bed load size distribution caused by different types of flow are compared in a high mountain catchment located in the upper Gallego river basin (Central Spanish’ Pyrenees). Three kinds of hydrologic events could be defined: those triggered by heavy autumn rainfalls, those originated by isolated summer rainstorms and those promoted by snowmelting. Each one is characterized by a peculiar bed load size distribution. Thus, it could be demonstrated that the coarser fractions, above 30 mm in di...

  14. Stabilizing Effects of Bacterial Biofilms: EPS Penetration and Redistribution of Bed Stability Down the Sediment Profile

    Science.gov (United States)

    Chen, X. D.; Zhang, C. K.; Zhou, Z.; Gong, Z.; Zhou, J. J.; Tao, J. F.; Paterson, D. M.; Feng, Q.

    2017-12-01

    Biofilms, consisting of microorganisms and their secreted extracellular polymeric substances (EPSs), serve as "ecosystem engineers" stabilizing sedimentary environments. Natural sediment bed provides an excellent substratum for biofilm growth. The porous structure and rich nutrients allow the EPS matrix to spread deeper into the bed. A series of laboratory-controlled experiments were conducted to investigate sediment colonization of Bacillus subtilis and the penetration of EPS into the sediment bed with incubation time. In addition to EPS accumulation on the bed surface, EPS also penetrated downward. However, EPS distribution developed strong vertical heterogeneity with a much higher content in the surface layer than in the bottom layer. Scanning electron microscope images of vertical layers also displayed different micromorphological properties of sediment-EPS matrix. In addition, colloidal and bound EPSs exhibited distinctive distribution patterns. After the full incubation, the biosedimentary beds were eroded to test the variation of bed stability induced by biological effects. This research provides an important reference for the prediction of sediment transport and hence deepens the understanding of the biologically mediated sediment system and broadens the scope of the burgeoning research field of "biomorphodynamics."

  15. Positive feedback and momentum growth during debris-flow entrainment of wet bed sediment

    Science.gov (United States)

    Iverson, R.M.; Reid, M.E.; Logan, M.; LaHusen, R.G.; Godt, J.W.; Griswold, J.P.

    2011-01-01

    Debris flows typically occur when intense rainfall or snowmelt triggers landslides or extensive erosion on steep, debris-mantled slopes. The flows can then grow dramatically in size and speed as they entrain material from their beds and banks, but the mechanism of this growth is unclear. Indeed, momentum conservation implies that entrainment of static material should retard the motion of the flows if friction remains unchanged. Here we use data from large-scale experiments to assess the entrainment of bed material by debris flows. We find that entrainment is accompanied by increased flow momentum and speed only if large positive pore pressures develop in wet bed sediments as the sediments are overridden by debris flows. The increased pore pressure facilitates progressive scour of the bed, reduces basal friction and instigates positive feedback that causes flow speed, mass and momentum to increase. If dryer bed sediment is entrained, however, the feedback becomes negative and flow momentum declines. We infer that analogous feedbacks could operate in other types of gravity-driven mass flow that interact with erodible beds. ?? 2011 Macmillan Publishers Limited. All rights reserved.

  16. Friction factor for water flow through packed beds of spherical and non-spherical particles

    Directory of Open Access Journals (Sweden)

    Kaluđerović-Radoičić Tatjana

    2017-01-01

    Full Text Available The aim of this work was the experimental evaluation of different friction factor correlations for water flow through packed beds of spherical and non-spherical particles at ambient temperature. The experiments were performed by measuring the pressure drop across the bed. Packed beds made of monosized glass spherical particles of seven different diameters were used, as well as beds made of 16 fractions of quartz filtration sand obtained by sieving (polydisperse non-spherical particles. The range of bed voidages was 0.359–0.486, while the range of bed particle Reynolds numbers was from 0.3 to 286 for spherical particles and from 0.1 to 50 for non-spherical particles. The obtained results were compared using a number of available literature correlations. In order to improve the correlation results for spherical particles, a new simple equation was proposed in the form of Ergun’s equation, with modified coefficients. The new correlation had a mean absolute deviation between experimental and calculated values of pressure drop of 9.04%. For non-spherical quartz filtration sand particles the best fit was obtained using Ergun’s equation, with a mean absolute deviation of 10.36%. Surface-volume diameter (dSV necessary for correlating the data for filtration sand particles was calculated based on correlations for dV = f(dm and Ψ = f(dm. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. ON172022

  17. Epinephrine, norepinephrine, and dopamine during a 4-day head-down bed rest.

    Science.gov (United States)

    Pequignot, J M; Guell, A; Gauquelin, G; Jarsaillon, E; Annat, G; Bes, A; Peyrin, L; Gharib, C

    1985-01-01

    Head-down bed rest at an angle of 6 degrees was used as an experimental model to simulate the hemodynamic effects of microgravity, i.e., the shift of fluids from the lower to the upper part of the body. The sympathoadrenal activity during acute (from 0.5 to 10 h) and prolonged (4 days) head-down bed rest was assessed in eight healthy men (24 +/- 1 yr) by measuring epinephrine (E), norepinephrine (NE), dopamine (DA), and methoxylated metabolite levels in their plasma and urine. Catecholamine (CA) and methoxyamine levels were essentially unaltered at any time of bed rest. Maximal changes in plasma were on the second day (D2): NE, 547 +/- 84 vs. 384 +/- 55 pg/ml; DA, 192 +/- 32 vs. 141 +/- 16 pg/ml; NS. After 24 h of bed rest, heart rate decreased from 71 +/- 1 to 63 +/- 3/min (P less than 0.01). Daily dynamic leg exercise [50% maximum O2 uptake (VO2 max)] used as a countermeasure did not alter the pattern of plasma CA during bed rest but resulted in a higher urinary NE excretion during postexercise recovery (+45% on D2; P less than 0.05). The data indicate no evident relationship between sympathoadrenal function and stimulation of cardiopulmonary receptors or neuroendocrine changes induced by central hypervolemia during head-down bed rest.

  18. Decreased daytime light intensity at nonwindow hospital beds: Comparisons with light intensity at window hospital beds and light exposure in nonhospitalized elderly individuals.

    Science.gov (United States)

    Iwamoto, Junko; Obayashi, Kenji; Kobayashi, Miwa; Kotsuji, Toshimichi; Matsui, Rie; Ito, Kyoko; Yoshida, Osamu; Kurumatani, Norio; Saeki, Keigo

    2018-01-26

    Light is crucial for the synchronization of internal biological rhythms with environmental rhythms. Hospitalization causes a range of unfavorable medical conditions, including delirium, sleep disturbances, depressed mood, and increased fall, especially in elderly people. The hospital room environment contributes significantly to patients' circadian physiology and behavior; however, few studies have evaluated light intensity in hospital settings. In this study, bedside light intensity during the daytime (6:00-21:00) was measured at 1-min intervals using a light meter on 4869 bed-days at the Inabe General Hospital in Mie, Japan (latitude 35°N), for approximately 1 month in each season. Daytime light exposure in home settings was measured in nonhospitalized elderly individuals (n = 1113) for two consecutive days at 1-min intervals using a wrist light meter. Median daytime light intensities at window and nonwindow hospital beds were 327.9 lux [interquartile range (IQR), 261.5-378.4] and 118.4 lux (IQR, 100.6-142.9), respectively, and daytime light intensity measured in nonhospitalized elderly individuals was 337.3 lux (IQR, 165.5-722.7). Compared with data in nonhospitalized elderly individuals, nonwindow beds were exposed to significantly lower daytime light intensity (p < 0.001), whereas window beds were exposed to similar daytime light intensity to that of home settings (p = 1.00). These results were consistent regardless of seasons (spring, summer, fall, and winter) or room directions (north vs. south facing). The lowest median daytime light intensity was observed at nonwindow beds in north-facing rooms during the winter (84.8 lux; IQR, 76.0-95.8). Further studies evaluating the incidence of in-hospital outcomes between patients hospitalized in window and nonwindow beds are needed.

  19. Sensitivity of growth characteristics of tidal sand ridges and long bed waves to formulations of bed shear stress, sand transport and tidal forcing : A numerical model study

    NARCIS (Netherlands)

    Yuan, Bing; de Swart, Huib E.; Panadès, Carles

    2016-01-01

    Tidal sand ridges and long bed waves are large-scale bedforms that are observed on continental shelves. They differ in their wavelength and in their orientation with respect to the principal direction of tidal currents. Previous studies indicate that tidal sand ridges appear in areas where tidal

  20. Fluidized bed incinerator development

    International Nuclear Information System (INIS)

    Ziegler, D.L.; Johnson, A.J.

    1976-01-01

    A fluidized bed incinerator is being developed for burning rad contaminated solid and liquid waste materials. In situ neutralization of acid gases by the bed material, catalytic afterburning, and gas filtration are used to produce a clean flue gas without the use of aqueous scrubbing

  1. Vestibular and Somatosensory Covergence in Postural Equilibrium Control: Insights from Spaceflight and Bed Rest Studies

    Science.gov (United States)

    Mulavara, A. P.; Batson, C. D.; Buxton, R. E.; Feiveson, A. H.; Kofman, I. S.; Lee, S. M. C.; Miller, C. A.; Peters, B. T.; Phillips, T.; Platts, S. H.; hide

    2014-01-01

    The goal of the Functional Task Test study is to determine the effects of space flight on functional tests that are representative of high priority exploration mission tasks and to identify the key underlying physiological factors that contribute to decrements in performance. We are currently conducting studies on both International Space Station (ISS) astronauts experiencing up to 6 months of microgravity and subjects experiencing 70 days of 6??head-down bed-rest as an analog for space flight. Bed-rest provides the opportunity for us to investigate the role of prolonged axial body unloading in isolation from the other physiological effects produced by exposure to the microgravity environment of space flight. This allows us to parse out the contribution of the body unloading somatosensory component on functional performance. Both ISS crewmembers and bed-rest subjects were tested using a protocol that evaluated functional performance along with tests of postural and locomotor control before and after space flight and bed-rest, respectively. Functional tests included ladder climbing, hatch opening, jump down, manual manipulation of objects and tool use, seat egress and obstacle avoidance, recovery from a fall, and object translation tasks. Astronauts were tested three times before flight, and on 1, 6, and 30 days after landing. Bed-rest subjects were tested three times before bed-rest and immediately after getting up from bed-rest as well as 1, 6, and 12 days after re-ambulation. A comparison of bed-rest and space flight data showed a significant concordance in performance changes across all functional tests. Tasks requiring a greater demand for dynamic control of postural equilibrium (i.e. fall recovery, seat egress/obstacle avoidance during walking, object translation, jump down) showed the greatest decrement in performance. Functional tests with reduced requirements for postural stability showed less reduction in performance. Results indicate that body unloading

  2. Heat-transfer characteristics of flowing and stationary particle-bed-type fusion-reactor blankets

    Energy Technology Data Exchange (ETDEWEB)

    Nietert, R.E.

    1983-02-01

    The heat-transfer characteristics of flowing and stationary packed-particle beds have recently become of interest in connection with conceptual designs of fusion reactor blankets. A detailed literature survey has shown that the processes taking place in such beds are not fully understood despite their widespread use in the chemical industry and other engineering disciplines for more than five decades. In this study, two experimental investigations were pursued. In the first, a heat-transfer loop was constructed through which glass microspheres were allowed to flow by rgravity at controlled rates through an electrically heated stainless steel tubular test section. In the second, an annular packed bed was constructed in which heat was applied through the outer wall by electric heating of a stainless steel tube. Cooling occurred at the inner wall of the annular bed by flowing air through the central tube. A second air stream was allowed to flow through the voids of the packed bed. An error-minimization technique was utilized in order to obtain the two-dimensional one-parameter effective conductivity for the bed by comparing the experimental and theoretically predicted temperature profiles. Experiments were conducted for various modified Reynolds numbers less than ten.

  3. Analysis of nursing home use and bed supply: Wisconsin, 1983.

    OpenAIRE

    Nyman, J A

    1989-01-01

    This article presents evidence that in 1983 excess demand was a prevailing characteristic of nursing home care markets in Wisconsin, a state with one of the highest bed to elderly population ratios. It further shows that excess demand is the source of at least three types of error in use-based estimates of the determinants of the need for nursing home care. First, if excess demand is present, estimates of the determinants of Medicaid use may simply represent a crowding out of Medicaid patient...

  4. Self-organization and chaos in a fluidized bed

    International Nuclear Information System (INIS)

    Daw, C.S.; Finney, C.E.A.; Vasudevan, M.; van Goor, N.A.; Nguyen, K.; Bruns, D.D.; Kostelich, E.J.; Grebogi, C.; Ott, E.; Yorke, J.A.

    1995-01-01

    We present experimental evidence that a complex system of particles suspended by upward-moving gas can exhibit low-dimensional bulk behavior. Specifically, we describe large-scale collective particle motion referred to as slugging in an industrial device known as a fluidized bed. As gas flow increases from zero, the bulk motion evolves from a fixed point to periodic oscillations to oscillations intermittently punctuated by ''stutters,'' which become more frequent as the flow increases further. At the highest flow tested, the behavior becomes extremely complex (''turbulent'')

  5. Near-bed gradients in particles and nutrients above a mussel bed in the Limfjorden: influence of physical mixing and mussel filtration

    NARCIS (Netherlands)

    Petersen, J.K.; Maar, M.; Ysebaert, T.; Herman, P.M.J.

    2013-01-01

    The aim of this field study was to investigate the role of mussels on near-bed layer characteristics at different hydrodynamic regimes in a micro-tidal system. At Løgstør Broad, the Limfjorden, Denmark, we deployed ‘siphon mimics’ to sample chlorophyll a (chl a), particulate organic carbon (POC) and

  6. Characteristics and associated factors in patient falls, and effectiveness of the lower height of beds for the prevention of bed falls in an acute geriatric hospital.

    Science.gov (United States)

    Menéndez, M D; Alonso, J; Miñana, J C; Arche, J M; Díaz, J M; Vazquez, F

    2013-01-01

    Whereas several studies about patient falls have provided data for long-term healthcare institutions, less information is available for acute care centres. The objective was to analyze the characteristics of the patient falls and associated factors, and the effectiveness of the lower beds' height to reduce the frequency and the harms of the patient falls in an acute geriatric hospital. A descriptive and retrospective study using a mandatory safety incident report, the IHI Global Trigger Tool, and the claims related to patient falls between 2007 and 2011 in a 200-bed university-associated geriatric hospital. The falls rate was 5.4 falls per 1000 patient days (1.3% of falls led to fractures) and there was exitus in 6 patients (0.6%). Nearly half of the falls ocurred during the night shift (42.4%). By wards, falls were more frequent in acute geriatric wards (42.9%). A 7.5% of patients had a fall before admission. 3 (0.2%) claims due to possible clinical negligence were found. A reduction (28.3%) of bed falls with the lower height of the bed and a 1.88 times less falls with harm (RR 0.53; CI 95% 0.83-0.34) (p=0.006) was observed. The prevention of patient falls is an important task in geriatric units with a potential reduction of harms and costs, some measures such as the lower height of the bed showed a significant reduction of the falls. Copyright © 2012 SECA. Published by Elsevier Espana. All rights reserved.

  7. Psychiatric hospital beds and prison populations in South America since 1990: does the Penrose hypothesis apply?

    Science.gov (United States)

    Mundt, Adrian P; Chow, Winnie S; Arduino, Margarita; Barrionuevo, Hugo; Fritsch, Rosemarie; Girala, Nestor; Minoletti, Alberto; Mitkiewicz, Flávia; Rivera, Guillermo; Tavares, María; Priebe, Stefan

    2015-02-01

    In 1939, English mathematician, geneticist, and psychiatrist Lionel Sharples Penrose hypothesized that the numbers of psychiatric hospital beds and the sizes of prison populations were inversely related; 75 years later, the question arises as to whether the hypothesis applies to recent developments in South America. To explore the possible association of changes in the numbers of psychiatric hospital beds with changes in the sizes of prison populations in South America since 1990. We searched primary sources for the numbers of psychiatric hospital beds in South American countries since 1990 (the year that the Latin American countries signed the Caracas Declaration) and compared these changes against the sizes of prison populations. The associations between the numbers of psychiatric beds and the sizes of prison populations were tested using fixed-effects regression of panel data. Economic variables were considered as covariates. Sufficiently reliable and complete data were obtained from 6 countries: Argentina, Bolivia, Brazil, Chile, Paraguay, and Uruguay. The numbers of psychiatric beds and the sizes of prison populations. Since 1990, the numbers of psychiatric beds decreased in all 6 countries (ranging from -2.0% to -71.9%), while the sizes of prison populations increased substantially (ranging from 16.1% to 273.0%). Panel data regression analysis across the 6 countries showed a significant inverse relationship between numbers of psychiatric beds and sizes of prison populations. On average, the removal of 1 bed was associated with 5.18 more prisoners (95% CI, 3.10-7.26; P = .001), which was reduced to 2.78 prisoners (95% CI, 2.59-2.97; P prison populations remained practically unchanged when income inequality was considered as a covariate (-4.28 [95% CI, -5.21 to -3.36]; P prison populations have increased against a background of strong economic growth. The changes appear to be associated because the numbers of beds decreased more extensively when and

  8. Trousseau: economic and design aspects from the second half of 20th century in Brazil

    Science.gov (United States)

    Laktim, M. C.; Giacomin, A. M.; Silva-Santos, M. C.; Santos, H. N.; Borelli, C.; Baruque-Ramos, J.

    2017-10-01

    The trousseau is notorious since antiquity and has been influenced by a series of modifications, reflected in the type of fabric, confection, design, fashion and market share. This study aimed to present economic and design aspects of the bedding, table and bath linen sector (also known as bed, bath and beyond) occurred from the second half of the 20th century to recently in Brazil. A bibliographic research was carried out from the scientific literature and magazines of the area, notably the “Revista Vogue Casa Brasil” (“Vogue House Brazil Magazine”). It is concluded that the classic patterns predominate: white color and cotton in bed, table and bath products, being embroidery the most outstanding style ornament. The maintenance of these standards by the Brazilian manufacturers is interesting to maintain sales in the domestic market, but a limitation for export products destined to publics with different values and aesthetic tastes and with greater supply of items with variety of surface designs.

  9. Airflow attenuation and bed net utilization: observations from Africa and Asia

    DEFF Research Database (Denmark)

    von Seidlein, Lorenz; Ikonomidis, Konstantin; Bruun, Rasmus

    2012-01-01

    Background/Methods Qualitative studies suggest that bed nets affect the thermal comfort of users. To understand and reduce this discomfort the effect of bed nets on temperature, humidity, and airflow was measured in rural homes in Asia and Africa, as well as in an experimental wind tunnel. Two...... investigators with architectural training selected 60 houses in The Gambia, Tanzania, Philippines, and Thailand. Data-loggers were used to measure indoor temperatures in hourly intervals over a 12 months period. In a subgroup of 20 houses airflow, temperature and humidity were measured at five-minute intervals...... on temperature and humidity. The discomfort associated with bed nets is likely to be most intolerable during the hottest and most humid period of the year, which frequently coincides with the peak of malaria vector densities and the force of pathogen transmission. Conclusions These observations suggest thermal...

  10. Development of a vibrofluidized bed and fluid-dynamic study with dry and wet adipic acid

    Directory of Open Access Journals (Sweden)

    Silva-Moris V.A.

    2003-01-01

    Full Text Available The vibrofluidized bed developed in this work, consisting of a transparent plexiglass tube with an inner diameter of 0.1 m and a height of 0.5 m, was designed for the fluidization of adipic acid. The fluidization behavior of dry adipic acid with particle diameters in the range of 75 - 600 mm and a density of 1340kg/m³ was studied using mechanical vibration for different sample loads. Variables studied for the wet material include frequency and amplitude of vibration and moisture content of the particles. On the basis of the quantitative flow curve data and visual observations, it is concluded that the fluid dynamics of the bed with wet sticky particles, both vibrating and not vibrating, is different from that of the bed with dry particles.

  11. Development of Bed Ridges in Open Channels and their Effects on Secondary Currents and Wall Shear

    Directory of Open Access Journals (Sweden)

    Kamran Ansari

    2012-07-01

    Full Text Available A numerical analysis of the ridges on the bed of wide, open channels and their effects on the distribution of secondary currents and wall shear is undertaken using CFD (Computational Fluid Dynamics. The presence of the lines of boil, consisting of low speed streaks, periodically in the transverse direction, is reported in the literature due to the presence of the ridges. In the present work, simulations are run on channel sections with varying the number of ridges on the bed and the size of these ridges. The effect of these variations on the flow structures and shear stress distribution in wide open channels is reported. The results offer an interesting insight into the 3D (Three-Dimensional flow structures involved and the link between flow structures and bed morpho-dynamics in prismatic channels.

  12. Tephrochronology of Bed II, Olduvai Gorge, Tanzania, and placement of the Oldowan-Acheulean transition.

    Science.gov (United States)

    McHenry, Lindsay J; Stanistreet, Ian G

    2018-04-12

    Tuffaceous marker beds, derived from volcanic products from the Ngorongoro Volcanic Highlands, help define a stratigraphic framework for the world-renowned fossil and stone tool record exposed at Olduvai Gorge, Tanzania. However, previous efforts to constrain this tuff record, especially for Olduvai Bed II, have been limited because of erosion, contamination, reworking, and the alteration of volcanic glass under saline-alkaline conditions. This paper applies previously defined geochemical and mineralogical "fingerprints" for several major Bed II marker tuffs, based on glass (where available) and phenocrysts more resistant to alteration (feldspar, hornblende, augite, and titanomagnetite), to tuffs from stratigraphic sections in the Olduvai Junction Area, including previously and recently excavated Acheulean and Oldowan sites (HWK EE (Locality (Loc) 42), EF-HR (Loc 12a), FLK (Loc 45), and MNK (Loc 88)). The Middle Bed II Bird Print Tuff (BPT) is found to be more compositionally variable than previously reported but is still valuable as a stratigraphic marker over short distances. The confirmation of blocks of Tuff IID in conglomerate helps constrain Upper Bed II stratigraphy at sites where in-situ tuffs are absent. This paper also compiles the results of published geochronological research, providing stratigraphic context and updating previously reported dates using a consistent 40 Ar/ 39 Ar reference standard age. The results of this work support the following paleoanthropologically relevant conclusions: 1) the early Acheulean site EF-HR (Loc 12a) is situated above the level of Hay's Tuff IIC, and thus sits in Upper rather than Middle Bed II, (2) the HWK EE (Loc 42) Oldowan site is constrained between Tuff IIA and Tuff IIB, just above the boundary between Lower and Middle Bed II, and 3) the Acheulean site at FLK W most likely lies within the Middle Augitic Sandstone, above Tuff IIB, similar to the placements by Leakey and Hay for the earliest Acheulean at Olduvai

  13. VA National Bed Control System

    Data.gov (United States)

    Department of Veterans Affairs — The VA National Bed Control System records the levels of operating, unavailable and authorized beds at each VAMC, and it tracks requests for changes in these levels....

  14. Coevolution of bed surface patchiness and channel morphology: 1. Mechanisms of forced patch formation

    Science.gov (United States)

    Nelson, Peter A.; McDonald, Richard R.; Nelson, Jonathan M.; Dietrich, William E.

    2015-01-01

    Riverbeds frequently display a spatial structure where the sediment mixture composing the channel bed has been sorted into discrete patches of similar grain size. Even though patches are a fundamental feature in gravel bed rivers, we have little understanding of how patches form, evolve, and interact. Here we present a two-dimensional morphodynamic model that is used to examine in greater detail the mechanisms responsible for the development of forced bed surface patches and the coevolution of bed morphology and bed surface patchiness. The model computes the depth-averaged channel hydrodynamics, mixed-grain-size sediment transport, and bed evolution by coupling the river morphodynamic model Flow and Sediment Transport with Morphological Evolution of Channels (FaSTMECH) with a transport relation for gravel mixtures and the mixed-grain-size Exner equation using the active layer assumption. To test the model, we use it to simulate a flume experiment in which the bed developed a sequence of alternate bars and temporally and spatially persistent forced patches with a general pattern of coarse bar tops and fine pools. Cross-stream sediment flux causes sediment to be exported off of bars and imported into pools at a rate that balances downstream gradients in the streamwise sediment transport rate, allowing quasi-steady bar-pool topography to persist. The relative importance of lateral gravitational forces on the cross-stream component of sediment transport is a primary control on the amplitude of the bars. Because boundary shear stress declines as flow shoals over the bars, the lateral sediment transport is increasingly size selective and leads to the development of coarse bar tops and fine pools.

  15. Fluidized bed combustion of low-grade coal and wastes: Research and development

    Energy Technology Data Exchange (ETDEWEB)

    Borodulya, V.A.; Dikalenko, V.I.; Palchonok, G.I.; Vinogradov, L.M. [Academy of Sciences of Belarus, Minsk (Belarus). A.V. Luikov Heat and Mass Transfer Inst.; Dobkin, S.M.; Telegin, E.M. [Special Design Office, Brest (Belarus)

    1994-12-31

    Experimental studies were carried out to investigate devolatilization of fuel as single spherical particles of wood, hydrolytic lignin, leather sewage sludge and Belarussian brown coals in a fluidized bed of sand. It is found that the devolatilization process depends on moisture and ash contents in fuel and on the external heat and mass transfer rate. The char combustion occurs largely in the intermediate region. Kinetic parameters of the devolatilization and char combustion are obtained. A low-capacity fluidized bed boiler suitable for combustion of coal and different wastes is described.

  16. Understanding and modeling retention of mammalian cells in fluidized bed centrifuges.

    Science.gov (United States)

    Kelly, William; Rubin, Jonathan; Scully, Jennifer; Kamaraju, Hari; Wnukowski, Piotr; Bhatia, Ravinder

    2016-11-01

    Within the last decade, fully disposable centrifuge technologies, fluidized-bed centrifuges (FBC), have been introduced to the biologics industry. The FBC has found a niche in cell therapy where it is used to collect, concentrate, and then wash mammalian cell product while continuously discarding centrate. The goal of this research was to determine optimum FBC conditions for recovery of live cells, and to develop a mathematical model that can assist with process scaleup. Cell losses can occur during bed formation via flow channels within the bed. Experimental results with the kSep400 centrifuge indicate that, for a given volume processed: the bed height (a bed compactness indicator) is affected by RPM and flowrate, and dead cells are selectively removed during operation. To explain these results, two modeling approaches were used: (i) equating the centrifugal and inertial forces on the cells (i.e., a force balance model or FBM) and (ii) a two-phase computational fluid dynamics (CFD) model to predict liquid flow patterns and cell retention in the bowl. Both models predicted bed height vs. time reasonably well, though the CFD model proved more accurate. The flow patterns predicted by CFD indicate a Coriolis-driven flow that enhances uniformity of cells in the bed and may lead to cell losses in the outflow over time. The CFD-predicted loss of viable cells and selective removal of the dead cells generally agreed with experimental trends, but did over-predict dead cell loss by up to 3-fold for some of the conditions. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1520-1530, 2016. © 2016 American Institute of Chemical Engineers.

  17. Experimental measurement of variation of heat transfer coefficient and temperature gradients in 16'' deep fluidised beds

    International Nuclear Information System (INIS)

    Blacker, P.T.; McLain, D.R.

    1962-04-01

    The object of the experiments was to choose suitable particulate materials for a fluidised bed cooler, to test a deep fluidised bed for uniformity of heat transfer coefficient, and to explore the temperature distribution in a centrally heated annular fluidised bed. This memorandum records the techniques used and some of the practical aspects involved, together with the performance results obtained, for the assistance of other experimenters who may wish to use fluidised beds as a laboratory technique. Mathematical correlation of the results has not been attempted since some of the properties of the bed material were not known and to determine them was beyond the scope of the work programme. Rather, we have compared our results with those of other experimenters. Graphite tubes, for use in steady state thermal stress experiments, are to be heated by a graphite radiant heater situated in the bore and cooled on the outer surface. The tubes are 2 cm. bore, 8 cm. outside diameter and 48 cm. long. The outside temperature of the tubes is to be between 500 deg. C. and 1500 deg. C. It is estimated that the heat transfer rate required for fracture at the outer surface is 30 watts/cm 2 . This could readily be achieved by cooling with liquid metals, water or high velocity gas. However, serious problems of either materials compatibility or mechanical complexity make these undesirable. A water-cooled fluidised bed of compatible solids fluidised with nitrogen gas can overcome most of these problems and give heat transfer coefficients close to that required, vis. about 0.1 w/cm C . A coolant bed about 20'' long would be required and an annulus of about 2'' radial width round the specimen was considered to be practicable

  18. The Effects of Long Duration Bed Rest on Functional Mobility and Balance: Relationship to Resting State Motor Cortex Connectivity

    Science.gov (United States)

    Erdeniz, B.; Koppelmans, V.; Bloomberg, J. J.; Kofman, I. S.; DeDios, Y. E.; Riascos-Castaneda, R. F.; Wood, S. J.; Mulavara, A. P.; Seidler, R. D.

    2014-01-01

    NASA offers researchers from a variety of backgrounds the opportunity to study bed rest as an experimental analog for space flight. Extended exposure to a head-down tilt position during long duration bed rest can resemble many of the effects of a low-gravity environment such as reduced sensory inputs, body unloading and increased cephalic fluid distribution. The aim of our study is to a) identify changes in brain function that occur with prolonged bed rest and characterize their recovery time course; b) assess whether and how these changes impact behavioral and neurocognitive performance. Thus far, we completed data collection from six participants that include task based and resting state fMRI. The data have been acquired through the bed rest facility located at the University of Texas Medical Branch (Galveston, TX). Subjects remained in bed with their heads tilted down 6 degrees below their feet for 70 consecutive days. Behavioral measures and neuroimaging assessments were obtained at seven time points: a) 7 and 12 days before bed rest; b) 7, 30, and 65 days during bed rest; and c) 7 and 12 days after bed rest. Functional connectivity magnetic resonance imaging (FcMRI) analysis was performed to assess the connectivity of motor cortex in and out of bed rest. We found a decrease in motor cortex connectivity with vestibular cortex and the cerebellum from pre bed rest to in bed rest. We also used a battery of behavioral measures including the functional mobility test and computerized dynamic posturography collected before and after bed rest. We will report the preliminary results of analyses relating brain and behavior changes. Furthermore, we will also report the preliminary results of a spatial working memory task and vestibular stimulation during in and out of bed rest.

  19. Communication of bed allocation decisions in a critical care unit and accountability for reasonableness

    Directory of Open Access Journals (Sweden)

    Swota Alissa H

    2005-10-01

    Full Text Available Abstract Background Communication may affect perceptions of fair process for intensive care unit bed allocation decisions through its impact on the publicity condition of accountability for reasonableness. Methods We performed a qualitative case study to describe participant perceptions of the communication of bed allocation decisions in an 18-bed university affiliated, medical-surgical critical care unit at Sunnybrook and Women's College Health Sciences Centre. Interviewed participants were 3 critical care physicians, 4 clinical fellows in critical care, 4 resource nurses, 4 "end-users" (physicians who commonly referred patients to the unit, and 3 members of the administrative staff. Median bed occupancy during the study period (Jan-April 2003 was 18/18; daily admissions and discharges (median were 3. We evaluated our description using the ethical framework "accountability for reasonableness" (A4R to identify opportunities for improvement. Results The critical care physician, resource nurse, critical care fellow and end-users (trauma team leader, surgeons, neurosurgeons, anesthesiologists functioned independently in unofficial "parallel tracks" of bed allocation decision-making; this conflicted with the official designation of the critical care physician as the sole authority. Communication between key decision-makers was indirect and could exclude those affected by the decisions; notably, family members. Participants perceived a lack of publicity for bed allocation rationales. Conclusion The publicity condition should be improved for critical care bed allocation decisions. Decision-making in the "parallel tracks" we describe might be unavoidable within usual constraints of time, urgency and demand. Formal guidelines for direct communication between key participants in such circumstances would help to improve the fairness of these decisions.

  20. Occurrence and distribution of different bed types of seagrass Posidonia oceanica around the Maltese Islands

    Directory of Open Access Journals (Sweden)

    J.A. BORG

    2009-12-01

    Full Text Available The small-scale distribution of Posidonia oceanica bed types were mapped at four locations off the northern coast of the Maltese Islands, using aerial photography supplemented by surveys using SCUBA diving. Results showed a similar pattern of occurrence of the seagrass at all locations surveyed. In shallow waters (2 m – 4 m, P. oceanicaoccurred as patches of variable size on a rocky and/or sandy substratum. In deeper waters (5 m – 10 m, the patches of seagrass were often replaced by reticulate beds consisting of P. oceanicainterspersed with areas of bare sand. Deeper still (11 m – 13 m, a transition from reticulate to continuous beds occurred. Continuous beds extended to depths of around 25 - 30 m and eventually became reticulate or patchy in deeper waters (>25 m. Values of total seagrass percentage cover increased, while the ratio of fragmented:continuous bed cover decreased for the four study locations on moving southwards (Ramla Bay to St Thomas Bay, indicating that P. oceanica habitat was more abundant and less fragmented in the south-eastern parts of the Maltese Islands. However, values calculated using an exposure index did not did indicate a relationship between exposure and the observed decease in fragmentation of seagrass beds on moving northwest to southwest along the north-eastern coast. Data from the four sites surveyed, together with data from other surveys, were used to show the large-scale distribution of P. oceanica beds around the Maltese Islands. The implications of the study findings for the conservation and management of P. oceanica habitat around the Maltese Islands are discussed.

  1. Hypoxia Worsens Affective Responses and Feeling of Fatigue During Prolonged Bed Rest

    Directory of Open Access Journals (Sweden)

    Nektarios A. M. Stavrou

    2018-03-01

    Full Text Available Previous research, although limited, suggests that both hypoxia and bed rest influence psychological responses by exaggerating negative psychological responses and attenuating positive emotions. The present study investigated the effect of a 21-day prolonged exposure to normobaric hypoxia and bed rest on affective responses and fatigue. Eleven healthy participants underwent three 21-day interventions using a cross-over design: (1 normobaric hypoxic ambulatory confinement (HAMB, (2 normobaric hypoxic bed rest (HBR and (3 normoxic bed rest (NBR. Affective and fatigue responses were investigated using the Activation Deactivation Adjective Check List, and the Multidimensional Fatigue Inventory, which were completed before (Pre, during (Day 7, Day 14, and Day 21 and after (Post the interventions. The most negative psychological profile appeared during the HBR intervention. Specifically, tiredness, tension, general and physical fatigue significantly increased on days 7, 14, and 21, as well as at Post. After the HBR intervention, general and physical fatigue remained higher compared to Pre values. Additionally, a deterioration of psychological responses was also noted following HAMB and NBR. In particular, both hypoxia and BR per se induced subjective fatigue and negative affective responses. BR seems to exert a moderate negative effect on the sensation of fatigue, whereas exercise attenuates the negative effects of hypoxia as noted during the HAMB condition. In conclusion, our data suggest that the addition of hypoxia to bed rest-induced inactivity significantly worsens affective responses and feeling of fatigue.

  2. Understanding Sediment Sources, Pathways, and Sinks in Regional Sediment Management: Application of Wash Load and Bed-Material Load Concept

    National Research Council Canada - National Science Library

    Biedenham, David S; Hubbard, Lisa C; Thome, Colin R; Watson, Chester C

    2006-01-01

    ... through the fluvial system for sediments derived from various bed, bank, gully, and catchment sources thereby providing a reliable analytical foundation for effective regional sediment management...

  3. [Thermal energy utilization analysis and energy conservation measures of fluidized bed dryer].

    Science.gov (United States)

    Xing, Liming; Zhao, Zhengsheng

    2012-07-01

    To propose measures for enhancing thermal energy utilization by analyzing drying process and operation principle of fluidized bed dryers,in order to guide optimization and upgrade of fluidized bed drying equipment. Through a systematic analysis on drying process and operation principle of fluidized beds,the energy conservation law was adopted to calculate thermal energy of dryers. The thermal energy of fluidized bed dryers is mainly used to make up for thermal consumption of water evaporation (Qw), hot air from outlet equipment (Qe), thermal consumption for heating and drying wet materials (Qm) and heat dissipation to surroundings through hot air pipelines and cyclone separators. Effective measures and major approaches to enhance thermal energy utilization of fluidized bed dryers were to reduce exhaust gas out by the loss of heat Qe, recycle dryer export air quantity of heat, preserve heat for dry towers, hot air pipes and cyclone separators, dehumidify clean air in inlets and reasonably control drying time and air temperature. Such technical parameters such air supply rate, air inlet temperature and humidity, material temperature and outlet temperature and humidity are set and controlled to effectively save energy during the drying process and reduce the production cost.

  4. Disproportional changes in hematocrit, plasma volume, and proteins during exercise and bed rest.

    Science.gov (United States)

    Van Beaumont, W.; Greenleaf, J. E.; Juhos, L.

    1972-01-01

    The interrelationships between the changes in plasma volume, hematocrit, and plasma proteins during muscular exercise and bed rest were investigated. Proportionally, the changes in hematocrit are always smaller than the changes in plasma volume. For this reason changes in the concentration of blood constituents can only be quantitated on the basis of plasma volume changes. During short periods of intensive exercise, there was a small loss of plasma proteins. With prolonged submaximal exercise there was a net gain in plasma protein, which contributes to stabilization of the vascular volume. Prolonged bed rest induced hypoproteinemia; this loss of plasma protein probably plays an important role in recumbency hypovolemia.

  5. Body Unloading Associated with Space Flight and Bed-rest Impacts Functional Performance

    Science.gov (United States)

    Bloomberg, J. J.; Ballard, K. L.; Batson, C. D.; Buxton, R. E.; Feiveson, A. H.; Kofman, I. S.; Lee, S. M. C.; Miller, C. A.; Mulavara, A. P.; Peters, B. T.; hide

    2014-01-01

    The goal of the Functional Task Test study is to determine the effects of space flight on functional tests that are representative of high priority exploration mission tasks and to identify the key underlying physiological factors that contribute to decrements in performance. Ultimately this information will be used to assess performance risks and inform the design of countermeasures for exploration class missions. We are currently conducting studies on both ISS crewmembers and on subjects experiencing 70 days of 6 degrees head-down bed-rest as an analog for space flight. Bed-rest provides the opportunity for us to investigate the role of prolonged axial body unloading in isolation from the other physiological effects produced by exposure to the microgravity environment of space flight. This allows us to parse out the contribution of the body unloading component on functional performance. In this on-going study both ISS crewmembers and bed-rest subjects were tested using an interdisciplinary protocol that evaluated functional performance and related physiological changes before and after 6 months in space and 70 days of 6? head-down bed-rest, respectively. Functional tests included ladder climbing, hatch opening, jump down, manual manipulation of objects and tool use, seat egress and obstacle avoidance, recovery from a fall, and object translation tasks. Crewmembers were tested three times before flight, and on 1, 6 and 30 days after landing. Bed-rest subjects were tested three times before bed-rest and immediately after getting up from bed-rest as well as 1, 6 and 12 days after reambulation. A comparison of bed-rest and space flight data showed a significant concordance in performance changes across all functional tests. Tasks requiring a greater demand for dynamic control of postural equilibrium (i.e. fall recovery, seat egress/obstacle avoidance during walking, object translation, jump down) showed the greatest decrement in performance. Functional tests with

  6. Factors associated with bed and room sharing in Chinese school-aged children.

    Science.gov (United States)

    Li, S; Jin, X; Yan, C; Wu, S; Jiang, F; Shen, X

    2009-03-01

    Co-sleeping (bed or room sharing) has potential implications for children's development. Previous studies showed that co-sleeping was more prevalent in non-Western countries than in Western countries, which demonstrated that co-sleeping was marked with ethnic and socio-cultural background characteristics. The purpose of this study was to survey the prevalence of bed and room sharing and to examine related factors among school-aged children in an Asian country - China. A cross-sectional questionnaire survey was conducted in 10 districts of Shanghai, China from November to December 2005. A total of 4108 elementary school children, 49.2% boys and 50.8% girls with a mean age of 8.79 years, participated. Parent-administered questionnaires were used to collect information about children's sleeping arrangements and socio-demographic characteristics. The prevalence of routine bed sharing, room sharing and sleeping alone in Chinese school-aged children was 21.0%, 19.1% and 47.7%, respectively. Bed and room sharing didn't show significant gender difference but gradually decreased with increasing age. Multivariate logistic regression identified those factors associated with bed and room sharing: younger age, large family, children without their own bedroom and parents' approval of a co-sleeping arrangement. Co-sleeping arrangement was a common practice in Chinese school-aged children. Associated factors were characterized by intrinsic socio-cultural values and socio-economic status in China.

  7. Waste Water Treatment-Bed of Coal Fly Ash for Dyes and Pigments Industry

    International Nuclear Information System (INIS)

    Shah, S.F.A.; Aftab, A.; Soomro, N.; Nawaz, M.S.; Vafai, K.

    2015-01-01

    The highly porous power plant waste ashes have been utilized to treat toxic effluent of a dyes manufacturing plant. An attempt has been made for the first time in Pakistan, to generate an effective and economically sound treatment facility for the toxic effluent of a dyes manufacturing plant. This is an indigenous bed which could replace expensive treatment facilities, such as reverse osmosis (RO), granulated activated carbon (GAC) bed, etc. The treatment efficiency was improved by coupling coagulants with fly ash adsorbent bed. The ash was collected from coal fired boilers of power plant at Lakhra Power Generation Company, Jamshoro, Pakistan. The use of this ash resolved the disposal and environmental issues by treating wastewater of chemical, dyes and pigment industry. The treatment bed comprised of briquettes of coal fly ash coupled with commercial coagulant ferrous sulfate-lime reduced COD, color, turbidity and TSS of effluent remarkably. An adsorption capacity and chemical behavior of fly ash bed was also studied. In coagulation treatment, coagulant FeSO/sun 4/-lime influenced reduction of COD, color, turbidity and TSS by 32 percentage, 48 percentage, 50 percentage and 51 percentage, respectively. The CFAB coupled with coagulant, resulted an excessive removal of color, TSS, COD, and turbidity by 88 percentage, 92 percentage, 67 percentage and 89 percentage, respectively. (author)

  8. Waste Water Treatment-Bed of Coal Fly Ash for Dyes and Pigments Industry

    Directory of Open Access Journals (Sweden)

    Syed Farman Ali Shah

    2015-12-01

    Full Text Available The highly porous power plant waste ashes have been utilized to treat toxic effluent of a dyes manufacturing plant. An attempt has been made for the first time in Pakistan, to generate an effective and economically sound treatment facility for the toxic effluent of a dyes manufacturing plant. This is an indigenous bed which could replace expensive treatment facilities, such as reverse osmosis (RO, granulated activated carbon (GAC bed, etc. The treatment efficiency was improved by coupling coagulants with fly ash adsorbent bed. The ash was collected from coal fired boilers of power plant at Lakhra Power Generation Company, Jamshoro, Pakistan. The use of this ash resolved the disposal and environmental issues by treating wastewater of chemical, dyes and pigment industry. The treatment bed comprised of briquettes of coal fly ash coupled with commercial coagulant ferrous sulfate-lime reduced COD, color, turbidity and TSS of effluent remarkably. An adsorption capacity and chemical behavior of fly ash bed was also studied. In coagulation treatment, coagulant FeSO4-lime influenced reduction of COD, color, turbidity and TSS by 32%, 48%, 50% and 51%, respectively. The CFAB coupled with coagulant, resulted an excessive removal of color, TSS, COD, and turbidity by 88%, 92%, 67% and89%, respectively.

  9. The potential carcinogenic risk of tanning beds: clinical guidelines and patient safety advice

    International Nuclear Information System (INIS)

    Mogensen, Mette; Jemec, Gregor BE

    2010-01-01

    In 2009, the WHO listed ultraviolet (UV) radiation as a group 1 carcinogen. In spite of this, each year, millions of people tan indoor in Western countries. The aim of this review is to summarize evidence of tanning bed carcinogenesis and to present guidelines for use of tanning beds and patient safety advice. A narrative review of the literature was conducted based on both PubMed and Medline searches and on literature review of the retrieved papers. Use of indoor tanning beds represents a significant and avoidable risk factor for the development of both melanoma and nonmelanoma skin cancers. Frequent tanners are more often adolescent females. Tanning beds have additional potential adverse effects such as burns, solar skin damage, infection, and possibly also addictive behavior. The effort in preventing UV light-induced carcinogenesis should currently be aimed at developing new strategies for public health information. Tanning beds are one preventable source of UV radiation. In the majority of people solar UV radiation continues to be the major factor and therefore anti-tanning campaigns must always include sunbathers

  10. Binge Eating Disorder (BED) in Relation to Addictive Behaviors and Personality Risk Factors.

    Science.gov (United States)

    Davis, Caroline; Mackew, Laura; Levitan, Robert D; Kaplan, Allan S; Carter, Jacqueline C; Kennedy, James L

    2017-01-01

    While there is good evidence that binge eating disorder (BED) is linked to higher-than-expected use of a broad range of addictive behaviors, mechanisms underlying this association are not well understood. Using a mediation-analytical approach with three age- and gender-matched groups - overweight/obese adults with ( n = 42) and without ( n = 104) BED, and normal-weight control participants ( n = 73) - we tested the hypothesis that adults with BED would engage in more addictive behaviors and have higher scores on a personality-risk index than the two control groups. We also anticipated that the relationship between BED and addictive behaviors would be mediated by a high-risk personality profile. The predicted mediation effect was strongly supported. Contrary to expectation, BED participants did not engage in more addictive behaviors or have higher personality-risk scores than their weight-matched counterparts. However, both overweight/obese groups did have significantly higher scores than the normal-weight group. The relationships among personality risk, elevated body mass index (BMI), and addictive behaviors have important clinical implications, especially for treatments that target psycho-behavioral intervention for compulsive overeating and substance-use disorders.

  11. Expected hazards and hospital beds in host cities of the 2014 FIFA World Cup in Brazil

    Directory of Open Access Journals (Sweden)

    Elaine Silva Miranda

    Full Text Available Planning for mass gatherings involves health system preparedness based on an understanding of natural and technological hazards identified through prior risk assessment. We present the expected hazards reported by health administrators of the host cities for the 2014 FIFA World Cup in Brazil and discuss the hazards considering minimal available public hospital beds in the 12 cities at the time of the event. Four different groups of respondents were interviewed: pharmaceutical service administrators and overall health administrators at both the municipal and hospital levels. The hospital bed occupancy rate was calculated, based on the Brazilian Health Informatics Department (DATASUS. The number of surplus beds was calculated using parameters from the literature regarding surge and mass casualty needs and number of unoccupied beds. In all groups, physical injuries ranked first, followed by emerging and endemic diseases. Baseline occupancy rates were high (95%CI: 0.93-2.19 in all 12 cities. Total shortage, considering all the cities, ranged from -47,670 (for surges to -60,569 beds (for mass casualties. The study can contribute to discussions on mass-gathering preparedness.

  12. Binge Eating Disorder (BED in Relation to Addictive Behaviors and Personality Risk Factors

    Directory of Open Access Journals (Sweden)

    Caroline Davis

    2017-04-01

    Full Text Available While there is good evidence that binge eating disorder (BED is linked to higher-than-expected use of a broad range of addictive behaviors, mechanisms underlying this association are not well understood. Using a mediation-analytical approach with three age- and gender-matched groups – overweight/obese adults with (n = 42 and without (n = 104 BED, and normal-weight control participants (n = 73 – we tested the hypothesis that adults with BED would engage in more addictive behaviors and have higher scores on a personality-risk index than the two control groups. We also anticipated that the relationship between BED and addictive behaviors would be mediated by a high-risk personality profile. The predicted mediation effect was strongly supported. Contrary to expectation, BED participants did not engage in more addictive behaviors or have higher personality-risk scores than their weight-matched counterparts. However, both overweight/obese groups did have significantly higher scores than the normal-weight group. The relationships among personality risk, elevated body mass index (BMI, and addictive behaviors have important clinical implications, especially for treatments that target psycho-behavioral intervention for compulsive overeating and substance-use disorders.

  13. Expected hazards and hospital beds in host cities of the 2014 FIFA World Cup in Brazil.

    Science.gov (United States)

    Miranda, Elaine Silva; Shoaf, Kimberley; Silva, Raulino Sabino da; Freitas, Carolina Figueiredo; Osorio-de-Castro, Claudia Garcia Serpa

    2017-06-12

    Planning for mass gatherings involves health system preparedness based on an understanding of natural and technological hazards identified through prior risk assessment. We present the expected hazards reported by health administrators of the host cities for the 2014 FIFA World Cup in Brazil and discuss the hazards considering minimal available public hospital beds in the 12 cities at the time of the event. Four different groups of respondents were interviewed: pharmaceutical service administrators and overall health administrators at both the municipal and hospital levels. The hospital bed occupancy rate was calculated, based on the Brazilian Health Informatics Department (DATASUS). The number of surplus beds was calculated using parameters from the literature regarding surge and mass casualty needs and number of unoccupied beds. In all groups, physical injuries ranked first, followed by emerging and endemic diseases. Baseline occupancy rates were high (95%CI: 0.93-2.19) in all 12 cities. Total shortage, considering all the cities, ranged from -47,670 (for surges) to -60,569 beds (for mass casualties). The study can contribute to discussions on mass-gathering preparedness.

  14. Interactions among Carbon Dioxide, Heat, and Chemical Lures in Attracting the Bed Bug, Cimex lectularius L. (Hemiptera: Cimicidae

    Directory of Open Access Journals (Sweden)

    Narinderpal Singh

    2012-01-01

    Full Text Available Commercial bed bug (Cimex lectularius L. monitors incorporating carbon dioxide (CO2, heat, and chemical lures are being used for detecting bed bugs; however, there are few reported studies on the effectiveness of chemical lures in bed bug monitors and the interactions among chemical lure, CO2, and heat. We screened 12 chemicals for their attraction to bed bugs and evaluated interactions among chemical lures, CO2, and heat. The chemical lure mixture consisting of nonanal, 1-octen-3-ol, spearmint oil, and coriander Egyptian oil was found to be most attractive to bed bugs and significantly increased the trap catches in laboratory bioassays. Adding this chemical lure mixture when CO2 was present increased the trap catches compared with traps baited with CO2 alone, whereas adding heat did not significantly increase trap catches when CO2 was present. Results suggest a combination of chemical lure and CO2 is essential for designing effective bed bug monitors.

  15. State of the art and the future fuel portfolio of fluidized bed combustion systems; Status und kuenftiges Brennstoffportfolio bei Wirbelschichtfeuerungen

    Energy Technology Data Exchange (ETDEWEB)

    Szentannai, Pal; Friebert, Arpad; Winter, Franz [Technische Univ. Wien (Austria). Inst. fuer Verfahrens-, Umwelttechnik und technische Biowissenschaften

    2008-07-01

    Coal, biomass and substitute fuels energetically can be used efficiently and with low pollution in fluidized bed plants. In comparison to biomass there are significant differences between the circulating and stationary fluidized bed technology. The stationary fluidised bed is fed predominantly with biomasses and residual substances. Coal usually is the basis fuel in the circulating fluidised bed. Biomass and residual substances frequently are course-fired. The state of the art is the employment of a broad fuel mixture in small and large fluidized-bed combustion systems. Future developments present an increased use of sewage sludge, fluidized bed combustion systems with wood as a basis fuel, utilization of household waste and the gas production.

  16. Climate Science for a Sustainable Energy Future Test Bed and Data Infrastructure Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Dean N. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Foster, I. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Van Dam, Kerstin Kleese [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Shipman, G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2014-05-04

    The collaborative Climate Science for a Sustainable Energy Future (CSSEF) project started in July 2011 with the goal of accelerating the development of climate model components (i.e., atmosphere, ocean and sea ice, and land surface) and enhancing their predictive capabilities while incorporating uncertainty quantification (UQ). This effort required accessing and converting observational data sets into specialized model testing and verification data sets and building a model development test bed, where model components and sub-models can be rapidly evaluated. CSSEF’s prototype test bed demonstrated, how an integrated testbed could eliminate tedious activities associated with model development and evaluation, by providing the capability to constantly compare model output—where scientists store, acquire, reformat, regrid, and analyze data sets one-by-one—to observational measurements in a controlled test bed.

  17. Successful experience with limestone and other sorbents for combustion of biomass in fluid bed power boilers

    Energy Technology Data Exchange (ETDEWEB)

    Coe, D.R. [LG& E Power Systems, Inc., Irvine, CA (United States)

    1993-12-31

    This paper presents the theoretical and practical advantages of utilizing limestone and other sorbents during the combustion of various biomass fuels for the reduction of corrosion and erosion of boiler fireside tubing and refractory. Successful experiences using a small amount of limestone, dolomite, kaolin, or custom blends of aluminum and magnesium compounds in fluid bed boilers fired with biomass fuels will be discussed. Electric power boiler firing experience includes bubbling bed boilers as well as circulating fluid bed boilers in commercial service on biomass fuels. Forest sources of biomass fuels fired include wood chips, brush chips, sawmill waste wood, bark, and hog fuel. Agricultural sources of biomass fuels fired include grape vine prunings, bean straw, almond tree chips, walnut tree chips, and a variety of other agricultural waste fuels. Additionally, some urban sources of wood fuels have been commercially burned with the addition of limestone. Data presented includes qualitative and quantitative analyses of fuel, sorbent, and ash.

  18. The microelectronics and photonics test bed (MPTB) space, ground test and modeling experiments

    International Nuclear Information System (INIS)

    Campbell, A.

    1999-01-01

    This paper is an overview of the MPTB (microelectronics and photonics test bed) experiment, a combination of a space experiment, ground test and modeling programs looking at the response of advanced electronic and photonic technologies to the natural radiation environment of space. (author)

  19. Selected chemical characteristics and acute toxicity of urban stormwater, streamflow, and bed material, Maricopa County, Arizona

    Science.gov (United States)

    Lopes, T.J.; Fossum, K.D.

    1995-01-01

    Statistical analyses indicated that urban stormwater could degrade the quality of streamflow because of oil and grease, pesticides, dissolved trace metals, and ammonia in stormwater. Ammonia, lead, cadmium, and zinc are released by urban activities and accumulate in bed material. Ammonia could be from fertilizers, fecal matter, and other sources. Lead is probably from vehicles that use leaded gasoline. Cadmium and zinc could be from particulate metal in oil, brake pads, and other sources. Samples of the initial runoff from urban drainage basins appeared to be more toxic than flow-weighted composite samples, and stormwater was more harmful to fathead minnows than to Ceriodaphnia dubia. Streamflow samples from the Salt River were not toxic to either species. The sensitivity of fathead minnows to urban stormwater from most urban drainage basins indicated that the toxicants were detrimental to fish and could be present in stormwater throughout Phoenix. Results of toxicity identification evaluations indicated the toxicity was mostly due to organic constituents. Mortality, however, did not correlate with organophosphate pesticide concentrations. Surfactants and (or) other constituents leached from asphalt could be toxic. The most toxic bed-material samples were collected from an undeveloped drainage basin. Within urban-drainage basins, bed-material samples collected where stormwater accumulates appeared to be more toxic than samples collected from areas unaffected by stormwater. Mortality rates correlated with recoverable concentrations of zinc, copper, and cadmium; however these rates correlated poorly with pesticide concentrations. The bioavailability of trace metals appeared to be controlled by the adsorption properties of bed material.

  20. Determination of fluidized bed granulation end point using near-infrared spectroscopy and phenomenological analysis.

    Science.gov (United States)

    Findlay, W Paul; Peck, Garnet R; Morris, Kenneth R

    2005-03-01

    Simultaneous real-time monitoring of particle size and moisture content by near-infrared spectroscopy through a window into the bed of a fluidized bed granulator is used to determine the granulation end point. The moisture content and particle size determined by the near-infrared monitor correlates well with off-line moisture content and particle size measurements. The measured particle size is modeled using a population balance approach, and the moisture content is shown to follow accepted models during drying. Given a known formulation, with predefined parameters for peak moisture content, final moisture content, and final granule size, the near-infrared monitoring system can be used to control a fluidized bed granulation by determining when binder addition should be stopped and when drying of the granules is complete. Copyright 2005 Wiley-Liss, Inc. and the American Pharmacists Association.

  1. Bioavailability of sulfadiazine in rabbits using tablets prepared by direct compression and fluidized-bed granulation.

    Science.gov (United States)

    Ritschel, W A; Erni, W

    1977-10-01

    Experimental sulfadiazine tablets prepared by direct compression, using a commercially available direct compression tablet mass, were compared with experimental sulfadiazine tablets prepared by fluidized-bed granulation and commercially available sulfadiazine tablets USP. The values for friability and the time required to release 10 and 50% of the direct compression tablets were between those of the fluidized-bed tablets and the commercial product. With the commercial tablet as a standard, the extent of bioavailability was determined in rabbits; it was slightly higher for both the direct compression and fluidized-bed tablets. A statistically significant difference was found between the direct compression tablets and the standard with respect to the extent of bioavailability and the time of the peak.

  2. Numerical Simulation and Experimental Study of Deep Bed Corn Drying Based on Water Potential

    Directory of Open Access Journals (Sweden)

    Zhe Liu

    2015-01-01

    Full Text Available The concept and the model of water potential, which were widely used in agricultural field, have been proved to be beneficial in the application of vacuum drying model and have provided a new way to explore the grain drying model since being introduced to grain drying and storage fields. Aiming to overcome the shortcomings of traditional deep bed drying model, for instance, the application range of this method is narrow and such method does not apply to systems of which pressure would be an influential factor such as vacuum drying system in a way combining with water potential drying model. This study established a numerical simulation system of deep bed corn drying process which has been proved to be effective according to the results of numerical simulation and corresponding experimental investigation and has revealed that desorption and adsorption coexist in deep bed drying.

  3. Mechanics of the energy balance in large lowland rivers, and why the bed matters

    Science.gov (United States)

    Bray, Erin N.; Dozier, Jeff; Dunne, Thomas

    2017-09-01

    Along many rivers, dams trap sediment and water released from the dams is clear. Downstream of the dam, temperature variability along the river is controlled by climate that warms or cools the water, the flow magnitude, and the spectral properties of water and the river's bed. Using field observations, a synoptic numerical model without calibration couples a full-spectrum radiation balance with turbulent heat fluxes, bed conduction, and a hydraulic model that estimates depth and velocity. We show that variations in the river's temperature are sensitive to the albedo of the sediment on the bed, especially at shallow depths and smaller discharges. However, about half the solar radiation lies in a spectral range where water is highly absorptive; in these wavelengths, absorption is independent of depth. In spring and summer with many hours of sunlight, releases of cold water will have limited influence on temperatures beyond tens of kilometers downstream of a dam.

  4. Relation between shell beds and trace fossils of the Albian-Cenomanian Aitamir Formation in Amirabad anticline- northeast Mashhad

    OpenAIRE

    H., Mohamadian,; M., Mahmudy- Gharaie,; A., Mahboubi,; R., Moussavi- Harami,; A., Bayetgol,

    2012-01-01

    Aitamir Formation (Albian-Cenomanian) in the Kopet-Dagh Basin has diverse trace fossils and several shell beds. These trace fossils contain diverse ethological patterns, including domichnia, fodinichnia, grazing, equilibrichnia, navichnia, chemichnia and fugichnia. The types of shell beds distinguished based on differences in sedimentological, palaeoecological and taphonomic features. Shell beds and sandstone layers containing characteristic trace fossils represent a storm-influenced successi...

  5. Life threatening medullary injury following adenoidectomy and local anesthetic infiltration of the operative bed.

    Science.gov (United States)

    Hershman, Eli; Halberthal, Michael; Goldsher, Dorit; Golz, Avishai; Bar-Joseph, Gad

    2009-02-01

    To draw attention to a rare, life threatening complication of a rather common procedure, namely medullary injury following adenoidectomy and local anesthetic infiltration of the operative bed. Case report. A tertiary pediatric critical care unit. A healthy 7-year-old girl underwent adenoidectomy and local anesthetic infiltration of the adenoid bed with lidocaine and adrenaline. In the recovery room, nystagmus, dysarthria, dyspnea, inability to cough and right hemiparesis were noticed. Because of her inability to remove secretions tracheal intubation was performed, followed by severe, life threatening respiratory failure. Tracheal intubation, hemodynamic support, prolonged mechanical ventilation, nitric oxide, and tracheostomy. In children, local anesthetic infiltration of the adenoid bed may cause life-threatening medullary injury and its routine use should be re-considered.

  6. Simulated Moving Bed Chromatography: Separation and Recovery of Sugars and Ionic Liquid from Biomass Hydrolysates

    Science.gov (United States)

    Caes, Benjamin R.; Van Oosbree, Thomas R.; Lu, Fachuang; Ralph, John; Maravelias, Christos T.

    2015-01-01

    Simulated moving bed chromatography, a continuous separation method, enables the nearly quantitative recovery of sugar products and ionic liquid solvent from chemical hydrolysates of biomass. The ensuing sugars support microbial growth, and the residual lignin from the process is intact. PMID:23939991

  7. Prevalence and Characteristics of Bed-Sharing Among Black and White Infants in Georgia.

    Science.gov (United States)

    Salm Ward, Trina C; Robb, Sara Wagner; Kanu, Florence A

    2016-02-01

    To examine: (1) the prevalence and characteristics of bed-sharing among non-Hispanic Black and White infants in Georgia, and (2) differences in bed-sharing and sleep position behaviors prior to and after the American Academy of Pediatrics' 2005 recommendations against bed-sharing. Georgia Pregnancy Risk Assessment Monitoring System (PRAMS) data were obtained from the Georgia Department of Public Health. Analysis was guided by the socioecological model levels of: Infant, Maternal, Family, and Community/Society within the context of race. Data from 2004 to 2011 were analyzed to address the first objective and from 2000 to 2004 and 2006 to 2011 to address the second objective. Rao-Scott Chi square tests and backward selection unconditional logistic regression models for weighted data were built separately by race; odds ratios (OR) and 95 % Confidence Intervals (CIs) were calculated. A total of 6595 (3528 Black and 3067 White) cases were analyzed between 2004 and 2011. Significantly more Black mothers (81.9 %) reported "ever" bed-sharing compared to White mothers (56 %), p Blacks, the final model included infant age, pregnancy intention, number of dependents, and use of Women, Infant and Children (WIC) Services. For Whites, the final model included infant age, maternal age, financial stress, partner-related stress, and WIC. When comparing the period 2000-2004 to 2006-2011, a total of 10,015 (5373 Black and 4642 White cases) were analyzed. A significant decrease in bedsharing was found for both Blacks and Whites; rates of non-supine sleep position decreased significantly for Blacks but not Whites. Continued high rates of bed-sharing and non-supine sleep position for both Blacks and Whites demonstrate an ongoing need for safe infant sleep messaging. Risk profiles for Black and White mothers differed, suggesting the importance of tailored messaging. Specific research and practice implications are identified and described.

  8. A batch and fixed bed column study for fluorescein removal using chitosan modified by epichlorohydrin.

    Science.gov (United States)

    Silva, P M O; Francisco, J E; Cajé, J C M; Cassella, R J; Pacheco, W F

    2018-01-02

    This study evaluates the feasibility of commercial chitosan (CQ) and modified chitosan (MQ) by epichlorohydrin to be used as a solid phase to remove fluorescein (FSC) from aqueous solutions by two different approaches: in batch and on a fixed column bed. For the batch study, all parameters that influence sorption capacity were evaluated, such as: pH, mass, ionic strength, temperature and time of contact. In the optimized condition, 75% removal was obtained for FSC using CQ, while the modification allowed an increase up to 99%, as well as an increase in the stability of the polymer. In the fixed column bed study, the influence of all the parameters was evaluated through breakthrough curves, and the thermodynamics parameters of each approach were obtained. The results of these studies demonstrate that the modification with epichlorohydrin enhanced the sorptive properties (from 35% to 95% in fixed bed experiments) and the polymer stability (making it insoluble), making it suitable to be used in wastewater treatment.

  9. Heat transfer and flow characteristics around a finned-tube bank heat exchanger in fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    Honda, Ryosuke [Department of Mechanical Engineering, Kansai University, 3-3-35 Yamate-cho, Suita, Osaka 564-8680 (Japan); Umekawa, Hisashi [Department of Mechanical Engineering, Kansai University, 3-3-35 Yamate-cho, Suita, Osaka 564-8680 (Japan)], E-mail: umekawa@kansai-uac.jp; Ozawa, Mamoru [Department of Mechanical Engineering, Kansai University, 3-3-35 Yamate-cho, Suita, Osaka 564-8680 (Japan)

    2009-06-21

    Principal heat transfer mechanisms in a fluidized bed have been classified into three categories, i.e. solid convection, gas convection and radiation. Among these mechanisms, the solid convection is a dominant mechanism in the bubbling fluidized bed. This solid convection is substantially caused by the bubble movement, thus the visualization of the void fraction distribution becomes a very useful method to understand the characteristics of the fluidized-bed heat exchanger. In this study, the heat transfer coefficient and the void fraction around the heat transfer tube with annuler fin were measured. For the quantitative measurement of the void fraction, neutron radiography and image processing technique were employed. Owing to the existence of the annuler fin, the restriction of the particle movements was put. This restriction suppressed the disturbance caused by tubes, and the influence of the tube arrangement on the flow and heat transfer characteristics could be clearly expressed.

  10. Heat transfer and flow characteristics around a finned-tube bank heat exchanger in fluidized bed

    International Nuclear Information System (INIS)

    Honda, Ryosuke; Umekawa, Hisashi; Ozawa, Mamoru

    2009-01-01

    Principal heat transfer mechanisms in a fluidized bed have been classified into three categories, i.e. solid convection, gas convection and radiation. Among these mechanisms, the solid convection is a dominant mechanism in the bubbling fluidized bed. This solid convection is substantially caused by the bubble movement, thus the visualization of the void fraction distribution becomes a very useful method to understand the characteristics of the fluidized-bed heat exchanger. In this study, the heat transfer coefficient and the void fraction around the heat transfer tube with annuler fin were measured. For the quantitative measurement of the void fraction, neutron radiography and image processing technique were employed. Owing to the existence of the annuler fin, the restriction of the particle movements was put. This restriction suppressed the disturbance caused by tubes, and the influence of the tube arrangement on the flow and heat transfer characteristics could be clearly expressed.

  11. Centrifugation as a countermeasure during bed rest and dry immersion: What has been learned?

    Science.gov (United States)

    Clément, G; Paloski, W H; Rittweger, J; Linnarsson, D; Bareille, M P; Mulder, E; Wuyts, F L; Zange, J

    2016-06-07

    We review the studies that have evaluated intermittent short-radius centrifugation as a potential countermeasure for cardiovascular, musculoskeletal, and sensorimotor deconditioning in simulated weightlessness. The findings from 18 experimental protocols that have used bed rest and dry immersion for comparing the protective effects of centrifugation versus standing upright or walking, and the effects of continuous vs. periodic exposure to centrifugation are discussed. Centrifugation for as little as 30 min per day was found to be effective in mitigating orthostatic intolerance and strength in postural muscle after 5 days of bed rest, but it was not effective in mitigating plasma volume loss. To determine the optimal prescription for centrifugation as a countermeasure, we recommend further studies using (a) bed rest of longer duration, (b) individualized prescriptions of centrifugation combined with exercise, and (c) functional performance tests.

  12. GLUT4 and glycogen synthase are key players in bed rest-induced insulin resistance

    DEFF Research Database (Denmark)

    Biensø, Rasmus Sjørup; Jørgensen, Stine Ringholm; Kiilerich, Kristian

    2012-01-01

    To elucidate the molecular mechanisms behind physical inactivity-induced insulin resistance in skeletal muscle, 12 young, healthy male subjects completed 7 days of bed rest with vastus lateralis muscle biopsies obtained before and after. In six of the subjects, muscle biopsies were taken from both...... than before bed rest. This bed rest-induced insulin resistance occurred together with reduced muscle GLUT4, hexokinase II, protein kinase B/Akt1, and Akt2 protein level, and a tendency for reduced 3-hydroxyacyl-CoA dehydrogenase activity. The ability of insulin to phosphorylate Akt and activate....... The present findings demonstrate that physical inactivity-induced insulin resistance in muscle is associated with lower content/activity of key proteins in glucose transport/phosphorylation and storage....

  13. Seasonal Greenland Ice Sheet ice flow variations in regions of differing bed and surface topography

    Science.gov (United States)

    Sole, A. J.; Livingstone, S. J.; Rippin, D. M.; Hill, J.; McMillan, M.; Quincey, D. J.

    2015-12-01

    The contribution of the Greenland Ice Sheet (GrIS) to future sea-level rise is uncertain. Observations reveal the important role of basal water in controlling ice-flow to the ice sheet margin. In Greenland, drainage of large volumes of surface meltwater to the ice sheet bed through moulins and hydrofracture beneath surface lakes dominates the subglacial hydrological system and provides an efficient means of moving mass and heat through the ice sheet. Ice surface and bed topography influence where meltwater can access the bed, and the nature of its subsequent flow beneath the ice. However, no systematic investigation into the influence of topographic variability on Greenland hydrology and dynamics exists. Thus, physical processes controlling storage and drainage of surface and basal meltwater, and the way these affect ice flow are not comprehensively understood. This presents a critical obstacle in efforts to predict the future evolution of the GrIS. Here we present high-resolution satellite mapping of the ice-surface drainage network (e.g. lakes, channels and moulins) and measurements of seasonal variations in ice flow in south west Greenland. The region is comprised of three distinct subglacial terrains which vary in terms of the amplitude and wavelength and thus the degree to which basal topography is reflected in the ice sheet surface. We find that the distribution of surface hydrological features is related to the transfer of bed topography to the ice sheet surface. For example, in areas of thinner ice and high bed relief, moulins occur more frequently and are more uniformly dispersed, indicating a more distributed influx of surface-derived meltwater to the ice sheet bed. We investigate the implications of such spatial variations in surface hydrology on seasonal ice flow rates.

  14. High Levels Of Bed Occupancy Associated With Increased Inpatient And Thirty-Day Hospital Mortality In Denmark

    DEFF Research Database (Denmark)

    Madsen, Flemming; Ladelund, Steen; Linneberg, Allan

    2014-01-01

    to low bed occupancy rates. Being admitted to a hospital outside of normal working hours or on a weekend or holiday was also significantly associated with increased mortality. The health risks of bed shortages, including mortality, could be better documented as a priority health issue. Resources should......High bed occupancy rates have been considered a matter of reduced patient comfort and privacy and an indicator of high productivity for hospitals. Hospitals with bed occupancy rates of above 85 percent are generally considered to have bed shortages. Little attention has been paid to the impact...... of these shortages on patients' outcomes. We analyzed all 2.65 million admissions to Danish hospitals' departments of medicine in the period 1995-2012. We found that high bed occupancy rates were associated with a significant 9 percent increase in rates of in-hospital mortality and thirty-day mortality, compared...

  15. Exploratory and basic fluidized-bed combustion studies. Quarterly report, January-March 1980

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, I.; Myles, K.M.; Swift, W.M.

    1980-12-01

    This work supports development studies for both atmospheric and pressurized fluidized-bed coal combustion. Laboratory and process development studies are aimed at providing needed information on limestone utilization, removal of particulates and alkali metal compounds from the flue gas, control of SO/sub 2/ and trace pollutants emissions, and other aspects of fluidized-bed combustion. This report presents information on: (1) the development of a limestone utilization predictive methodology, (2) studies of particle breakup and elutriation, (3) basic studies on limestone sulfation enhancement by hydration, (4) studies of the kinetics of the hydration process, and (5) an investigation of various hydration process concepts.

  16. Design report on SCDAP/RELAP5 model improvements - debris bed and molten pool behavior

    International Nuclear Information System (INIS)

    Allison, C.M.; Rempe, J.L.; Chavez, S.A.

    1994-11-01

    The SCDAP/RELAP5/MOD3 computer code is designed to describe the overall reactor coolant system thermal-hydraulic response, core damage progression, and in combination with VICTORIA, fission product release and transport during severe accidents. Improvements for existing debris bed and molten pool models in the SCDAP/RELAP5/MOD3.1 code are described in this report. Model improvements to address (a) debris bed formation, heating, and melting; (b) molten pool formation and growth; and (c) molten pool crust failure are discussed. Relevant data, existing models, proposed modeling changes, and the anticipated impact of the changes are discussed. Recommendations for the assessment of improved models are provided

  17. Coupled dynamics of the co-evolution of gravel bed topography, flow turbulence and sediment transport in an experimental channel

    Science.gov (United States)

    Singh, Arvind; Foufoula-Georgiou, Efi; Porté-Agel, Fernando; Wilcock, Peter R.

    2012-12-01

    A series of flume experiments were conducted in a large experimental channel at the St. Anthony Falls Laboratory to understand the coupled dynamics of flow and bed forms above the sediment-water interface. Simultaneous high resolution measurements of velocity fluctuations, bed elevations and sediment flux at the downstream end of the channel, were made for a range of discharges. The probability density functions (pdfs) of bed elevation increments and instantaneous Reynolds stress reveal a power law tail behavior and a wavelet cross-correlation analysis depicts a strong dependence of these series across a range of scales, indicating a feedback between bed form dynamics and near-bed turbulence. These results complement our previous findings in which the signature of bed form evolution on the near-bed velocity fluctuations was confirmed via the presence of a spectral gap and two distinct power law scaling regimes in the spectral density of velocity fluctuations. We report herein a strong asymmetry in the probability distribution of bed elevation increments and instantaneous Reynolds stresses, the latter being further analyzed and interpreted via a quadrant analysis of velocity fluctuations in the longitudinal and vertical directions. We also report the presence of intermittency (multifractality) in bed elevation increments and interpret it, in view of the asymmetric nature of the pdfs, as the result of scale coupling. In other words, the geometric asymmetry at the bed form scale gets transferred down to a probabilistic asymmetry at all smaller scales indicating a local anisotropy in the energy transfer. Finally, we propose a predictive relationship between bed form averaged sediment transport rates and bed form averaged instantaneous Reynolds stress and validate it using our experimental data.

  18. An overview of the issues: physiological effects of bed rest and restricted physical activity

    Science.gov (United States)

    Convertino, V. A.; Bloomfield, S. A.; Greenleaf, J. E.

    1997-01-01

    Reduction of exercise capacity with confinement to bed rest is well recognized. Underlying physiological mechanisms include dramatic reductions in maximal stroke volume, cardiac output, and oxygen uptake. However, bed rest by itself does not appear to contribute to cardiac dysfunction. Increased muscle fatigue is associated with reduced muscle blood flow, red cell volume, capillarization and oxidative enzymes. Loss of muscle mass and bone density may be reflected by reduced muscle strength and higher risk for injury to bones and joints. The resultant deconditioning caused by bed rest can be independent of the primary disease and physically debilitating in patients who attempt to reambulate to normal active living and working. A challenge to clinicians and health care specialists has been the identification of appropriate and effective methods to restore physical capacity of patients during or after restricted physical activity associated with prolonged bed rest. The examination of physiological responses to bed rest deconditioning and exercise training in healthy subjects has provided significant information to develop effective rehabilitation treatments. The successful application of acute exercise to enhance orthostatic stability, daily endurance exercise to maintain aerobic capacity, or specific resistance exercises to maintain musculoskeletal integrity rather than the use of surgical, pharmacological, and other medical treatments for clinical conditions has been enhanced by investigation and understanding of underlying mechanisms that distinguish physical deconditioning from the disease. This symposium presents an overview of cardiovascular and musculoskeletal deconditioning associated with reduced physical work capacity following prolonged bed rest and exercise training regimens that have proven successful in ameliorating or reversing these adverse effects.

  19. Instability and the formation of bubbles and the plugs in fluidized beds

    Directory of Open Access Journals (Sweden)

    Piotr Schulz

    2004-01-01

    Full Text Available This is an review paper, particulary concentrate on results not many researches by reason that are explain in the text. We consider stability of disperse, two-phase flow (gas-solid particles or liquid-solid particles linear and non-linear. In particular we discuss the result of Anderson, Sundareson and Jackson (1995 [Anderson K., Sundareson S., Jackson R.: Instabilities and the formation of bubbles in fluidized beds. J. Fluid Mech. 303 (1995, 327-366] that for vertical dispersion flow one- and two-dimensional, they attack problem growing disturbances directly by numerical integration of equations of motion from given initial conditions (using computer Cray C-90. In principle, this would allow authors to explore all aspects of dynamical behaviour of fluidized beds. It is interesting mechanism of periodic plug describing by Anderson et al. and attest by other researchers. Second part of paper is more general, dedicate the problem of linear stability of uniformly fluidized state ("fluidized bed". We make the most important stages of calculations (after to Jackson (2000 [Jackson R.: The Dynamics of Fluidized Particles. Cambridge University Press 2000] and demonstrate that the majority (but not all of fluidized beds with parameters having technical importance is unstable, or stable in narrow interval of wave numbers \\(k\\.

  20. Palynologic and petrographic variation in the Otter Creek coal beds (Stephanian, Upper Carboniferous), Western Kentucky

    Energy Technology Data Exchange (ETDEWEB)

    Helfrich, C.T.; Hower, J.C. (Eastern Kentucky University, Richmond (USA))

    1989-08-30

    The palynology and petrology of the Lisman (Lower Otter Creek) and Upper Otter Creek coals of the Stephanian portion of the Sturgis Formation of the Western Kentucky coal field was investigated in samples from mine and roadcut exposures. The Lisman coal bed exhibits an upward decrease in palynologic diversity and an upward increase in inertinite macerals. These factors suggest a change in swamp paleoecology in response to a climate which was gradually becoming drier. The Upper Creek coal bed exhibits less lateral continuity in palynomorph assemblages than does the Lisman. The Upper Otter Creek palynomorph assemblages are less diverse than the Lisman assemblages. Overall, the variation in the Upper Otter Creek coal bed cannot be attributed with certainty to any factor other than the local relief within the swamp. 17 refs., 4 figs., 3 tabs.

  1. H₂-rich syngas production by fluidized bed gasification of biomass and plastic fuel.

    Science.gov (United States)

    Ruoppolo, G; Ammendola, P; Chirone, R; Miccio, F

    2012-04-01

    This paper reports the results of gasification tests using a catalytic fluidized bed gasifier to obtain a H(2)-rich stream by feeding different pellets made of wood, biomass/plastic and olive husks to the gasifier. The effects of both the steam supply and an in-bed catalyst on gasifier performance have been investigated. In general, pelletization was an effective pre-treatment for improving the homogeneity of the fuel and the reliability of the feeding devices. The use of biomass/plastic pellets in a catalyst bed yielded good results in terms of the hydrogen concentration (up to 32%vol.), even if an increase in tar production and in the fine/carbon elutriation rate was observed in comparison with wood pellets. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. Neurogenetic and morphogenetic heterogeneity in the bed nucleus of the stria terminalis

    International Nuclear Information System (INIS)

    Bayer, S.A.

    1987-01-01

    Neurogenesis and morphogenesis in the rat bed nucleus of the stria terminalis (strial bed nucleus) were examined with [ 3 H]thymidine autoradiography. For neurogenesis, the experimental animals were the offspring of pregnant females given an injection of [ 3 H]thymidine on 2 consecutive gestational days. Nine groups of embryos were exposed to [ 3 H]thymidine on E13-E14, E14-E15,... E21-E22, respectively. On P60, the percentage of labeled cells and the proportion of cells originating during 24-hour periods were quantified at six anteroposterior levels in the strial bed nucleus. On the basis of neurogenetic gradients, the strial bed nucleus was divided into anterior and posterior parts. The anterior strial bed nucleus shows a caudal (older) to rostral (younger) neurogenetic gradient. Cells in the vicinity of the anterior commissural decussation are generated mainly between E13 and E16, cells just posterior to the nucleus accumbens mainly between E15 and E17. Within each rostrocaudal level, neurons originate in combined dorsal to ventral and medial to lateral neurogenetic gradients so that the oldest cells are located ventromedially and the youngest cells dorsolaterally. The most caudal level has some small neurons adjacent to the internal capsule that originate between E17 and E20. In the posterior strial bed nucleus, neurons extend ventromedially into the posterior preoptic area. Cells are generated simultaneously along the rostrocaudal plane in a modified lateral (older) to medial (younger) neurogenetic gradient. Ventrolateral neurons originate mainly between E13 and E16, dorsolateral neurons mainly between E15 and E16, and medial neurons mainly between E15 and E17. The youngest neurons are clumped into a medial core area just ventral to the fornix

  3. Neurogenetic and morphogenetic heterogeneity in the bed nucleus of the stria terminalis

    Energy Technology Data Exchange (ETDEWEB)

    Bayer, S.A.

    1987-11-01

    Neurogenesis and morphogenesis in the rat bed nucleus of the stria terminalis (strial bed nucleus) were examined with (/sup 3/H)thymidine autoradiography. For neurogenesis, the experimental animals were the offspring of pregnant females given an injection of (/sup 3/H)thymidine on 2 consecutive gestational days. Nine groups of embryos were exposed to (/sup 3/H)thymidine on E13-E14, E14-E15,... E21-E22, respectively. On P60, the percentage of labeled cells and the proportion of cells originating during 24-hour periods were quantified at six anteroposterior levels in the strial bed nucleus. On the basis of neurogenetic gradients, the strial bed nucleus was divided into anterior and posterior parts. The anterior strial bed nucleus shows a caudal (older) to rostral (younger) neurogenetic gradient. Cells in the vicinity of the anterior commissural decussation are generated mainly between E13 and E16, cells just posterior to the nucleus accumbens mainly between E15 and E17. Within each rostrocaudal level, neurons originate in combined dorsal to ventral and medial to lateral neurogenetic gradients so that the oldest cells are located ventromedially and the youngest cells dorsolaterally. The most caudal level has some small neurons adjacent to the internal capsule that originate between E17 and E20. In the posterior strial bed nucleus, neurons extend ventromedially into the posterior preoptic area. Cells are generated simultaneously along the rostrocaudal plane in a modified lateral (older) to medial (younger) neurogenetic gradient. Ventrolateral neurons originate mainly between E13 and E16, dorsolateral neurons mainly between E15 and E16, and medial neurons mainly between E15 and E17. The youngest neurons are clumped into a medial core area just ventral to the fornix.

  4. Sex of college students moderates associations among bedtime, time in bed, and circadian phase angle.

    Science.gov (United States)

    Van Reen, Eliza; Sharkey, Katherine M; Roane, Brandy M; Barker, David; Seifer, Ronald; Raffray, Tifenn; Bond, Tamara L; Carskadon, Mary A

    2013-12-01

    Sex differences in circadian rhythms have been reported with some conflicting results. The timing of sleep and length of time in bed have not been considered, however, in previous such studies. The current study has 3 major aims: (1) replicate previous studies in a large sample of young adults for sex differences in sleep patterns and dim light melatonin onset (DLMO) phase; (2) in a subsample constrained by matching across sex for bedtime and time in bed, confirm sex differences in DLMO and phase angle of DLMO to bedtime; (3) explore sex differences in the influence of sleep timing and length of time in bed on phase angle. A total of 356 first-year Brown University students (207 women) aged 17.7 to 21.4 years (mean = 18.8 years, SD = 0.4 years) were included in these analyses. Wake time was the only sleep variable that showed a sex difference. DLMO phase was earlier in women than men and phase angle wider in women than men. Shorter time in bed was associated with wider phase angle in women and men. In men, however, a 3-way interaction indicated that phase angles were influenced by both bedtime and time in bed; a complex interaction was not found for women. These analyses in a large sample of young adults on self-selected schedules confirm a sex difference in wake time, circadian phase, and the association between circadian phase and reported bedtime. A complex interaction with length of time in bed occurred for men but not women. We propose that these sex differences likely indicate fundamental differences in the biology of the sleep and circadian timing systems as well as in behavioral choices.

  5. Processes and parameters involved in modeling radionuclide transport from bedded salt repositories. Final report. Technical memorandum

    International Nuclear Information System (INIS)

    Evenson, D.E.; Prickett, T.A.; Showalter, P.A.

    1979-07-01

    The parameters necessary to model radionuclide transport in salt beds are identified and described. A proposed plan for disposal of the radioactive wastes generated by nuclear power plants is to store waste canisters in repository sites contained in stable salt formations approximately 600 meters below the ground surface. Among the principal radioactive wastes contained in these canisters will be radioactive isotopes of neptunium, americium, uranium, and plutonium along with many highly radioactive fission products. A concern with this form of waste disposal is the possibility of ground-water flow occurring in the salt beds and endangering water supplies and the public health. Specifically, the research investigated the processes involved in the movement of radioactive wastes from the repository site by groundwater flow. Since the radioactive waste canisters also generate heat, temperature is an important factor. Among the processes affecting movement of radioactive wastes from a repository site in a salt bed are thermal conduction, groundwater movement, ion exchange, radioactive decay, dissolution and precipitation of salt, dispersion and diffusion, adsorption, and thermomigration. In addition, structural changes in the salt beds as a result of temperature changes are important. Based upon the half-lives of the radioactive wastes, he period of concern is on the order of a million years. As a result, major geologic phenomena that could affect both the salt bed and groundwater flow in the salt beds was considered. These phenomena include items such as volcanism, faulting, erosion, glaciation, and the impact of meteorites. CDM reviewed all of the critical processes involved in regional groundwater movement of radioactive wastes and identified and described the parameters that must be included to mathematically model their behavior. In addition, CDM briefly reviewed available echniques to measure these parameters

  6. Bed-parallel compaction bands in aeolian sandstone: Their identification, characterization and implications

    Science.gov (United States)

    Aydin, Atilla; Ahmadov, Ramil

    2009-12-01

    This study combines field observations and laboratory analyses to identify and characterize predominantly bed-parallel compaction bands in the aeolian Aztec Sandstone exposed in the Valley of Fire State Park, Nevada. These bed-parallel compaction bands display morphological and geometrical characteristics of deformation bands of various modes previously described in the literature, such as positive relief, echelon geometry, "bridge" and "eye" structure, and zonal occurrence. Portions of some bands cross-cut sedimentary layers, thereby distinguishing themselves from depositional bedding. Laboratory image analyses of several samples collected from bed-parallel bands, using a computational rock physics algorithm, show that their porosities are less than half that of the host rock and their permeability is nearly one order of magnitude less. In addition, the study area includes compaction bands that have dip angles ranging from sub-horizontal to greater than 20°. Parts of these bands have even higher dip angles and show evidence for increasing intragranular fracturing and shearing as the band inclination increases. We attribute this variation to shear-enhanced compaction, a mechanism proposed earlier by experimental rock mechanists. One of the implications of the occurrence of localized compaction in the form of discrete bands parallel to flat-lying and low-angle bedding is that it provides an alternative or an additional mode to a vertically continuous compaction in loose or poorly cemented sediments. If pervasive, bed-parallel compaction bands with significantly lower porosity than that of the surrounding undeformed rock should result in a significant heterogeneity and vertical anisotropy in seismic velocities and hydraulic properties of granular rocks.

  7. Antibody to P. falciparum in pregnancy varies with intermittent preventive treatment regime and bed net use.

    Directory of Open Access Journals (Sweden)

    Elizabeth H Aitken

    Full Text Available Antibodies towards placental-binding P. falciparum are thought to protect against pregnancy malaria; however, environmental factors may affect antibody development.Using plasma from pregnant Malawian women, we measured IgG against placental-binding P. falciparum parasites by flow cytometry, and related results to intermittent preventive treatment (IPTp regime, and bed net use. Bed net use was associated with decreased antibody levels at mid-pregnancy but not at 1 month post partum (1 mpp. At 1 mpp a more intensive IPTp regime was associated with decreased antibody levels in primigravidae, but not multigravidae.Results suggest bed nets and IPTp regime influence acquisition of pregnancy-specific P. falciparum immunity.

  8. Is baby too warm? The use of infant clothing, bedding and home heating in Victoria, Australia.

    Science.gov (United States)

    Watson, L; Potter, A; Gallucci, R; Lumley, J

    1998-05-29

    Overheating of infants has been associated with a raised risk for sudden infant death syndrome (SIDS). Data on the use of heating, bedding and clothing and other measures affecting the thermal environment of 4 week old infants were collected at a home interview for infants of women born in Australia (Anglo-Celtic background), in Southern Europe, in Asia and of women who had a planned out-of-hospital birth. These groups have different risks of SIDS not explained by the classic social and perinatal risk factors nor associated with the currently promoted 'new' risk factors. Thermal insulation of the infant's bedding and clothing and excess thermal insulation (for any observed room temperature) were calculated. Bed sharing differed significantly between the groups as did the use of a sheepskin, tucking in firmly, the closing of doors and windows and the use of heating in the infant's room. After stratifying by bed sharing practice and season of interview, it was found that bed sharing infants had more thermal insulation than those sleeping alone irrespective of season of interview. Infants sleeping alone in the Asian-born and Southern European-born groups were kept warmer than infants in the other two groups. Cultural factors appear to affect the thermal environment in which infants are raised. Some bed sharing infants in all four groups were inappropriately warm, particularly in colder weather, but this was more likely in the Asian-born (low risk) group than in the home birth (high risk) group. These results do not explain the differences in SIDS incidence between the groups.

  9. Measuring the Bed Load velocity in Laboratory flumes using ADCP and Digital Cameras

    Science.gov (United States)

    Conevski, Slaven; Guerrero, Massimo; Rennie, Colin; Bombardier, Josselin

    2017-04-01

    Measuring the transport rate and apparent velocity of the bedload is notoriously hard and there is not a certain technique that would obtain continues data. There are many empirical models, based on the estimation of the shear stress, but only few involve direct measurement of the bed load velocity. The bottom tracking (BT) mode of an acoustic Doppler current profiler (ADCP) has been used many times to estimate the apparent velocity of the bed load. Herein is the basic idea, to exploit the bias of the BT signal towards the bed load movement and to calibrate this signal with traditional measuring techniques. These measurements are quite scarce and seldom reliable since there are not taken in controlled conditions. So far, no clear confirmation has been conducted in laboratory-controlled conditions that would attest the assumptions made in the estimation of the apparent bed load velocity, nor in the calibration of the empirical equations. Therefore, this study explores several experiments under stationary conditions, where the signal of the ADCP BT mode is recorded and compared to the bed load motion recorded by digital camera videography. The experiments have been performed in the hydraulic laboratories of Ottawa and Bologna, using two different ADCPs and two different high resolution cameras. In total, more then 30 experiments were performed for different sediment mixtures and different hydraulic conditions. In general, a good match is documented between the apparent bed load velocity measured by the ADCP and the videography. The slight deviation in single experiments can be explained by gravel particles inhomogeneity, difficult in reproducing the same hydro-sedimentological conditions and the randomness of the backscattering strength.

  10. Turbulence structure and sand transport over gravel and cobble beds in laboratory flumes

    Science.gov (United States)

    Characterizing the turbulence generated by flow over rough beds has become increasingly important in support of efforts to predict sediment transport downstream of dams. The advanced age and impending decommissioning of many dams have brought increased attention to the fate of sediments stored in r...

  11. A new comprehensive model and simulation package for fluidized bed spray granulation processes

    Energy Technology Data Exchange (ETDEWEB)

    Ihlow, M.; Drechsler, J.; Peglow, M.; Henneberg, M. [AVA GbRmbH, Steinfeldstrasse 5, D-39179 Barleben-Magdeburg (Germany); Moerl, L. [Universitaet Magdeburg, Institut fuer Apparate- und Umwelttechnik, Postfach 4120, D-39016 Magdeburg (Germany)

    2004-11-01

    The model introduced in this paper makes it possible to calculate the expected product and bed material particle size distribution, as well as the dynamic behavior of process state variables. It was integrated in the developed software package FBSim and it could be shown that even a complex process like the fluidized bed spray granulation can be simulated in its dynamic behavior, if existing models are extended and coupled. The implemented model achieves a coupled solution of the population balance and heat and mass transfer equations. (Abstract Copyright [2004], Wiley Periodicals, Inc.)

  12. Hydrodynamic effects in trickle bed laboratory reactors for hydrodesulphurization and hydrodemetallization of heavy feeds

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, W.; Pazos, J.M.

    1982-01-01

    Trickle bed reactors are extensively used in the oil industry for hydrotreatment (HDT) of petroleum distillates, removal of impurities, such as sulphur and nitrogen, and hydrocracking. These reactors are also being used for HDT of residua, where hydrodesulphurization (HDS) and hydrodemetallization (HDM) are the key reactions. The purpose of this paper is to study the performance of small trickle bed reactors, at real space velocities used for HDS and HDM of heavy feeds. Particular attention is given to evaluate the effect of the mean particle diameter on reactor behaviour. The final objective is to obtain an empirical model, which considers the influence of the flow conditions and packing properties on reactor performance.

  13. Experimental Study on Pressure Drop and Flow Dispersion in Packed Bed of Natural Zeolite

    Directory of Open Access Journals (Sweden)

    Ruya Petric Marc

    2018-01-01

    Full Text Available The use of conventional correlation for pressure drop and dispersion coefficient calculation may result in inaccurate values for zeolite packed bed as the correlations are generally developed for regularly shaped and uniformly sized particles. To support the research on the application of modified natural zeolite as tar cracking catalyst, the research on the hydrodynamic behaviour of zeolite packed bed has been conducted. Experiments were carried out using a glass column with diameter of 37.8 mm. Natural zeolite with particle size of about 2.91 to 6.4 mm was applied as packing material in the column, and the bed height was varied at 9, 19 and 29 cm. Air was used as the fluid that flows through the bed and nitrogen was used as a tracer for residence time distribution determination. Air flow rates were in the range of 20 to 100 mL/s which correspond to the laminar-transitional flow regime. The pressure drops through the bed were in the range of 1.7 to 95.6 Pa, depending on the air flow rate and bed height. From these values, the parameters in the Ergun equation were estimated, taking into account the contribution by wall effect when the ratio of column to particle diameter is low. The viscous and inertial term constants in the Ergun equation calculated ranges from 179 to 199 and 1.41 to 1.47 respectively while the particle sphericity ranges from 0.56 to 0.59. The reactor Peclet number were determined to range from 5.2 to 5.5, which indicated significant deviation from a plug flow condition.

  14. Computational and experimental prediction of dust production in pebble bed reactors, Part II

    Energy Technology Data Exchange (ETDEWEB)

    Mie Hiruta; Gannon Johnson; Maziar Rostamian; Gabriel P. Potirniche; Abderrafi M. Ougouag; Massimo Bertino; Louis Franzel; Akira Tokuhiro

    2013-10-01

    This paper is the continuation of Part I, which describes the high temperature and high pressure helium environment wear tests of graphite–graphite in frictional contact. In the present work, it has been attempted to simulate a Pebble Bed Reactor core environment as compared to Part I. The experimental apparatus, which is a custom-designed tribometer, is capable of performing wear tests at PBR relevant higher temperatures and pressures under a helium environment. This environment facilitates prediction of wear mass loss of graphite as dust particulates from the pebble bed. The experimental results of high temperature helium environment are used to anticipate the amount of wear mass produced in a pebble bed nuclear reactor.

  15. Analysis of the start-up and control of a particle bed reactor

    International Nuclear Information System (INIS)

    Lazareth, O.W.; Araj, K.J.; Horn, F.L.; Ludewig, H.; Powell, J.R.

    1987-01-01

    This study describes the modeling of start-up transients in Particle Bed Reactors (PBR) for burst electric power. Two computer programs have been developed to analyze the start-up process. The first program (named KINETIC) analyzes the entire fuel element, calculating time dependent solutions for power and the temperature distribution in the packed bed. The second program (named SPHEAT, for Spherical Heating) calculates time-dependent temperatures inside individual, cladded fuel particles. The two programs provide powerful analytical tools for evaluation of material and geometrical options, power and time constraints, and conditions that could lead to element failures

  16. Adsorption of 90Sr and 90Y by bottom-set beds in the Atlantic ocean

    International Nuclear Information System (INIS)

    Gromov, V.V.; Shakhova, N.F.; Emel'yanov, E.M.

    1978-01-01

    The behaviour of 90 Sr and 90 Y has been studied in an adsorption system of sea water-bottom-set beds of the Atlantic ocean (red clay; pelitic silt). It has been shown that strontium is present in the sea water in one form, viz, Sr 2+ . Adsorption of 90 Sr with bottom-set beds follows the ion-exchange mechanism. Yttrium is present in the sea water at least three forms (two absorbable and one non-absorbable). Yttrium-90 adsorption is an irreversible process and only about 10% 90 Y is desorbed by the sea water from red clay and silt

  17. Nonlinear thermal interaction between a heat-generating particulate bed and a solid

    International Nuclear Information System (INIS)

    Cheung, F.B.; Stein, R.P.; Epstein, M.; Gabor, J.D.; Bingle, J.D.

    1980-01-01

    The process of combined conduction and radiation in a large, heat-generating, dry particulate bed in sudden contact with a semi-infinite solid is studied analytically by a successive approximation method and numerically by a finite difference method. The transient behavior of the system, in particular, the behavior of the temperature at the particulate bed-solid interface, is obtained as a function of two dimensionless controlling parameters. Also obtained are the conditions leading to incipient melting of the system. Based upon the finite difference solution, the present approximate method, which is shown to be rather simple and convenient to use, is found to yield rapidly converging and sufficiently accurate results

  18. Petrology and palynology of the No. 5 block coal bed, northeastern Kentucky

    Science.gov (United States)

    Hower, J.C.; Eble, C.F.; Rathbone, R.F.

    1994-01-01

    The upper Middle Pennsylvanian (middle Westphalian D equivalent) No. 5 Block coal bed (Eastern Kentucky Coal Field of the Central Appalachian Basin) is a low-sulfur, compliance coal resource, dominantly comprised of dull, inertinite-rich lithotypes. Ash yields tend to be highly variable in the No. 5 Block, as does bed thickness and frequency of bed splitting. This study describes the petrographic, palynologic and geochemical characteristics of the No. 5 Block coal bed, and reports on some temporal and spatial trends among these parameters in eastern-northeastern Kentucky. Petrographically the No. 5 Block coal is predominated by dull, often high-ash lithotypes, with inertinite contents commonly exceeding 30% (mmf). The coal thins to the north-northwest where it tends to be higher in vitrinite and sulfur content. Representatives of large and small lycopsids and ferns (both tree-like and small varieties) dominate the No. 5 Block coal bed palynoflora. Calamite spores and cordaite pollen also occur but are less abundant. Small lycopsid (Densosporites spp. and related crassicingulate genera) and tree fern (e.g. Punctatisporites minutus, Laevigatosporites globosus) spore taxa are most abundant in dull lithotypes. Bright lithotypes contain higher percentages of arboreous lycopsid spores (Lycospora spp.). Regionally, the No. 5 Block coal contains abundant Torispora securis, a tree fern spore specially adapted for desiccation prevention. This, along with overall high percentages of inertinite macerals, suggest that peat accumulation may have taken place in a seasonally dry (?) paleoclimate. The No. 5 Block coal bed thickens rather dramatically in a NW-SE direction, as does the frequency of coal bed splitting. This phenomenon appears to be related to increased accomodation space in the southeastern portion of the study area, perhaps via penecontemporaneous growth faulting. Maceral and palynomorph variations within the bed correspond with these changes. Thin coal along the

  19. Devolatilization and ash comminution of two different sewage sludges under fluidized bed combustion conditions

    Energy Technology Data Exchange (ETDEWEB)

    Solimene, R.; Urciuolo, M.; Cammarota, A.; Chirone, R. [Istituto di Ricerche sulla Combustione (IRC) - CNR, Napoli (Italy); Salatino, P. [Istituto di Ricerche sulla Combustione (IRC) - CNR, Napoli (Italy); Dipartimento di Ingegneria Chimica Universita degli Studi di Napoli Federico II, Napoli (Italy); Damonte, G.; Donati, C.; Puglisi, G. [ECODECO Gruppo A2A, Giussago (PV) (Italy)

    2010-04-15

    Two different wet sewage sludges have been characterized under fluidized bed combustion conditions with reference to their devolatilization behavior and ash comminution with the aid of different and complementary experimental protocols. Analysis of the devolatilization process allowed to determine the size of fuel particle able to achieve effective lateral spreading of the volatile matter across the cross-section of medium-scale combustors. Primary fragmentation and primary ash particle characterization pointed out the formation of a significant amount of relatively large fragments. The mechanical properties of these fragments have been characterized by means of elutriation/abrasion tests using both quartz and sludge ash beds. (author)

  20. Wet granulation in rotary processor and fluid bed: Comparison of granule and tablet properties.

    Science.gov (United States)

    Kristensen, Jakob; Hansen, Vibeke Wallaert

    2006-03-01

    The aim of the present study was to investigate and compare granule and tablet properties of granules prepared by wet granulation in a rotary processor or a conventional fluid bed. For this purpose the working range of selected process variables was determined and a factorial study with 3 factors (equipment type, filler type, and liquid addition rate) and 1 covariate (fluidizing air flow rate) was performed. Two grades of calcium carbonate with different size and shape characteristics were applied, and the liquid addition and fluidizing air flow rates were investigated in the widest possible range. Dry mixtures of microcrystalline cellulose, polyvinyl povidone, calcium carbonate, and riboflavin, in a 10∶5∶84∶1 ratio, were granulated in both types of equipment. The granulation end point was determined manually in the fluid bed and by torque measurements in the rotary processor. The filler type had a more pronounced effect on granular properties in the fluid bed, but the rotary processor showed a higher dependency on the investigated process variables. The rotary processor gave rise to more dense granules with better flow properties, but the fluid bed granules had slightly better compressional properties. Furthermore, the distribution of a low-dose drug was found to be more homogeneous in the rotary processor granules and tablets. Generally, wet granulation in a rotary processor was found to be a good alternative to conventional fluid bed granulation, especially when cohesive powders with poor flow properties or formulations with low drug content are to be granulated by a fluidizing air technique.

  1. Bed Rest and Hypoxic Exposure Affect Sleep Architecture and Breathing Stability

    Directory of Open Access Journals (Sweden)

    Shawnda A. Morrison

    2017-06-01

    Full Text Available Objective: Despite over 50 years of research on the physiological effects of sustained bed rest, data characterizing its effects on sleep macrostructure and breathing stability in humans are scarce. This study was conducted to determine the effects of continuous exposure to hypoxia and sustained best rest, both individually and combined, on nocturnal sleep and breathing stability.Methods: Eleven participants completed three randomized, counter-balanced, 21-days trials of: (1 normoxic bed rest (NBR, PIO2 = 133.1 ± 0.3, (2 hypoxic ambulatory confinement (HAMB, PIO2 = 90.0 ± 0.4 and (3 hypoxic bed rest (HBR, PIO2 = 90.0 ± 0.4; ~4,000 m equivalent altitude. Full objective polysomnography was performed at baseline, on Night 1 and Night 21 in each condition.Results: In NBR Night 1, more time was spent in light sleep (10 ± 2% compared to baseline (8 ± 2%; p = 0.028; Slow-wave sleep (SWS was reduced from baseline in the hypoxic-only trial by 18% (HAMB Night 21, p = 0.028 and further reduced by 33% (HBR Night 1, p = 0.010, and 36% (HBR Night 21, p = 0.008 when combined with bed rest. The apnea-hypopnea index doubled from Night 1 to Night 21 in HBR (32–62 events·h−1 and HAMB (31–59 events·h−1; p = 0.002. Those who experienced greatest breathing instability from Night 1 to Night 21 (NBR were correlated to unchanged or higher (+1% night SpO2 concentrations (R2 = 0.471, p = 0.020.Conclusion: Bed rest negatively affects sleep macrostructure, increases the apnea-hypopnea index, and worsens breathing stability, each independently exacerbated by continuous exposure to hypoxia.

  2. Effects of check dams on bed-load transport and steep-slope stream morphodynamics

    Science.gov (United States)

    Piton, Guillaume; Recking, Alain

    2017-08-01

    Check dams are transversal structures built across morphologically-active streams in mountainous regions. These structures have been used widely in torrent-hazard mitigation for over 150 years. Thousands of them are regularly maintained by stream managers and torrent-control services. The stabilization role of these structures is well known, i.e. they durably constrain the stream-bed through the creation of vertical and planar fixed points. What is not yet clear is to what extent check dams influence bed-load transport: How do peak solid discharge or flood-transported volume change when check dams are added to a reach? To address these questions, long-lasting small-scale experiments were conducted in a 4.8-m-long flume with either one, three or no structures. The results show that the addition of structures creates independent compartments in the bed level, which have a strong influence on bed surface armouring and stream morphodynamics: the consequence is that instantaneous transport intensities are unchanged, but peak solid discharge occur more often and for shorter duration. This results in the same total transported volume over the long term, but reduced volume for a single transport event. It reaffirms the observation of pioneering authors of the mid-19th and early 20th century who conceptualized the possible sediment transport regulation function of check dams: in addition to stabilizing the stream-bed, check dams influence bed-load transport through a buffering effect, releasing frequently and in small doses what, in their absence, would be transported abruptly en masse during rare extreme events.

  3. Effects of disking, bedding, and subsoiling on survival and growth of three oak species in central Mississippi

    Science.gov (United States)

    J. Paul Jeffreys; Emily B. Schultz; Thomas G. Matney; W. Cade Booth; Jason M. Morris

    2010-01-01

    A replicated split-plot design experiment to evaluate the effects of three site preparation methods (disking, bedding, and subsoiling plus bedding) on survival and growth of three oak species (cherrybark, Quercus pagoda Raf.; Shumard, Quercus shumardii Buckl.; and Nuttall, Quercus texana Buckl.) was established...

  4. ICU architectural design affects the delirium prevalence: a comparison between single-bed and multibed rooms*.

    Science.gov (United States)

    Caruso, Pedro; Guardian, Lilian; Tiengo, Tatiane; Dos Santos, Lucio Souza; Junior, Pedro Medeiros

    2014-10-01

    Delirium risk factors are related to the patients' acute and chronic clinical condition, treatment, and environment. The environmental risk factors are essentially determined by the ICU architectural design. Although there are countless architectural variations among the ICUs, all can be classified as single- or multibed rooms. Our objectives were to compare the ICU delirium prevalence and characteristics (coma/delirium-free days, first day in delirium, and delirium motoric subtypes) of critically ill patients admitted in single- or multibed rooms. Retrospective. ICU of a teaching oncologic hospital with 31 beds. Twenty-three beds distributed in one multibed room with 13 beds and other with 10 beds. Eight beds distributed in single-bed rooms. All adult patients admitted from February to November 2011. None. We evaluated 1,587 patients and included 1,253 patients. Patients' characteristics at ICU admission and their outcomes along the ICU stay were not different between patients admitted in single- or multibed rooms. One hundred sixty-three patients (13.0%) had delirium, and the prevalence was significantly lower in patients admitted in single-bed rooms (6.8% × 15.1%; p < 0.01). This lower prevalence occurred in patients admitted due to a medical (11.0% × 25.6%; p < 0.01) or postoperative (5.0% × 11.4%; p < 0.01) reason. However, the coma/delirium-free days, the first day in delirium, and the delirium motoric subtypes were not different between the single- and multibed rooms. The risk factors associated with delirium were admission in multibed rooms (odds ratio, 4.03; 95% CI, 2.13-7.62), older age, ICU-acquired infection, and higher Simplified Acute Physiology Score 3 and Sequential Organ Failure Assessment score. Critically ill patients admitted in single-bed rooms have a lower prevalence of delirium than those admitted in multibed rooms. However, coma/delirium-free days, first day in delirium, and motoric subtypes were not different.

  5. Household bed net ownership and use among under-5 children in Nigeria

    Directory of Open Access Journals (Sweden)

    Osuorah DC

    2013-07-01

    Full Text Available D Chidiebere Osuorah,1,2 Chijioke Elias Ezeudu,2 Stanley Kenechi Onah,2 Obinna Tochukwu Anyabolu31Child Survival Unit, Medical Research Council UK, The Gambia Unit, Banjul, The Gambia; 2Department of Pediatrics, Nnamdi Azikiwe University Teaching Hospital, Nnewi, Anambra, Nigeria; 3School of Health and Social Care, Oxford Brookes University, Oxford, UKBackground: Malaria remains the leading cause of morbidity and mortality in sub-Saharan Africa, with children under 5 years accounting for 86% of all malaria deaths. For effective control of malaria, WHO recommends rapid diagnosis and effective treatment, insecticide-treated bed nets, and indoor residual spraying. The use of insecticide-treated bed nets has been shown to be the most cost-effective strategy in preventing this infection. However, despite the Roll Back Malaria subsidized and free bed net distribution initiatives in some Africa countries, bed net uptake and usage still remains low in many households.Aim: This study aimed to investigate household characteristics and child factors that determine bed net ownership and use amongst under-5 children and the effect of its usage on malaria parasitemia in under-5 children in Nigeria.Methods: Data from a nationally representative sample of 5895 households was obtained from the 36 states and the Federal Capital Territory in the 2010 Nigeria demographic and health survey, with a minimum of 67 households enrolled per state. Appropriate statistical tools were used to identify the characteristics of households that owned a bed net and to examine the association between the households and child-level factors that predict the use of bed net and malaria prevalence among under-5 children within these households.Results: The rate of households bed net ownership in Nigeria is about 45.5%. About 48.5% of under-5 children in 33.9% of households surveyed, use a bed net during sleep. There was a strong correlation between households ownership and child

  6. Flow visualizing study of fluidized bed for incineration and/or coal combustion technology

    Energy Technology Data Exchange (ETDEWEB)

    Ozawa, Mamoru [Kansai Univ., Suita, Osaka (Japan). Faculty of Engineering

    1997-02-01

    A simulated fluidized-bed heat exchanger was visualized using a neutron radiography system. The void fraction distribution and its fluctuation were obtained by means of an image processing technique. On the basis of the processed image, the mechanism of a large particle movement and the flow pattern in the tube bank immersed in the bed were investigated. Observed flow pattern in the tube bank indicated an importance of the tube arrangement on the void fraction fluctuation and thus the heat transfer around tubes. (author)

  7. Mechanisms of formation and destruction of nitrogen oxides during polyamide incineration in a fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    Hahnel, F.; Gadiou, R.; Prado, G. [Univ. de Haute Alsace, Mulhouse (France). Lab. de Gestion des Risques et Environnement

    1998-09-01

    In order to study the incineration of nitrogen-containing polymers, a fludized bed has been built. This paper reports the results for polyamide 6-6 incineration. The main nitrogen containing species have been identified, and the axial profiles of concentration of nitrogen oxides, HCN and NH3 have been measured. The main steps of decomposition of the polyamide were identified. We present an experimental investigation of the influence of operating parameters (temperature, excess air) on the formation and reduction of polymer combustion products. The yields of conversion of nitrogen to the different N-species have been calculated as a function of excess air in the fluidized bed. (orig.)

  8. Operating experience and data on revolving type fluidized bed incineration plants

    International Nuclear Information System (INIS)

    Nakayama, J.

    1990-01-01

    In refuse incinerators operating by revolving fluidization (Revolving Type Fluidized Bed Incinerator) a broad range of wastes, from low caloric refuse of high moisture content to high caloric value material including a wide variety of plastics, can be incinerated at high efficiency because the unit is outstanding in terms of distribution of waste in the incinerator bed and uniformity of heat. In addition, its vigorous revolving fluidization action is very effective in pulverizing refuse, so even relatively strict emission standards can be met without fine pre-shredding. Residues are discharged in a clean, dry form free of putrescible material. Data on practical operation of the revolving fluidized bed incinerator are presented in this paper

  9. Mechanical and Structural Behavior of Granular Material Packed Beds for Space Life Support System Applications

    Science.gov (United States)

    Malla, Ramesh B.; Anandakumar, Ganesh

    2005-01-01

    Long-term human mission to space, such as living in International Space Station (ISS), Lunar, and Martian bases, and travel to Mars, must m ake use of Advanced Life Support Systems (ALSS) to generate and recycle critical life supporting elements like oxygen and water. Oxygen Gen eration Assembly (OGA) and Water Processor Assembly (WPA), critical c omponents of ALSS, make use of series of granular material packed beds for generation and recycling of oxygen and water. Several granular m aterials can be used for generation, recycling, processing and recovery of oxygen and water. For example, they may include soft bed media, e.g. ion exchange resins for oxygen generation assembly and hard bed media such as, activated alumina, magchem (Magnesium oxide) and activa ted carbon to remove organic species like ethanol, methanol, and urea from wastewater in Water recovery/processing assembly. These beds are generally packed using a plate-spring mechanism to provide sufficien t compaction to the bed media throughout the course of operation. This paper presents results from an experimental study of a full-scale, 3 8.1 cm (15 inches) long and 3.7 cm (1.44 inches) diameter. activated alumina bed enclosed in a cylinder determining its force-displacement behavior, friction mobilizing force, and axial normal stress distribu tion under various axially applied loads and at different levels of packing. It is observed that force-displacement behavior is non-linear for low compaction level and becomes linear with increase in compaction of the bed media. Axial normal stress distribution along the length of the bed media decreased non-linearly with increase in depth from the loading end of the granular media. This paper also presents experimental results on the amount of particulates generated corresponding to various compaction levels. Particulates generated from each of the tests were measured using standard US sieves. It was found that the p articulates and the overall displacement of

  10. Hydrogeochemistry and coal-associated bacterial populations from a methanogenic coal bed

    Science.gov (United States)

    Barnhart, Elliott P.; Weeks, Edwin P.; Jones, Elizabeth J.P.; Ritter, Daniel J.; McIntosh, Jennifer C.; Clark, Arthur C.; Ruppert, Leslie F.; Cunningham, Alfred B.; Vinson, David S.; Orem, William H.; Fields, Matthew W.

    2016-01-01

    Biogenic coalbed methane (CBM), a microbially-generated source of natural gas trapped within coal beds, is an important energy resource in many countries. Specific bacterial populations and enzymes involved in coal degradation, the potential rate-limiting step of CBM formation, are relatively unknown. The U.S. Geological Survey (USGS) has established a field site, (Birney test site), in an undeveloped area of the Powder River Basin (PRB), with four wells completed in the Flowers-Goodale coal bed, one in the overlying sandstone formation, and four in overlying and underlying coal beds (Knoblach, Nance, and Terret). The nine wells were positioned to characterize the hydraulic conductivity of the Flowers-Goodale coal bed and were selectively cored to investigate the hydrogeochemistry and microbiology associated with CBM production at the Birney test site. Aquifer-test results indicated the Flowers-Goodale coal bed, in a zone from about 112 to 120 m below land surface at the test site, had very low hydraulic conductivity (0.005 m/d) compared to other PRB coal beds examined. Consistent with microbial methanogenesis, groundwater in the coal bed and overlying sandstone contain dissolved methane (46 mg/L average) with low δ13C values (−67‰ average), high alkalinity values (22 meq/kg average), relatively positive δ13C-DIC values (4‰ average), and no detectable higher chain hydrocarbons, NO3−, or SO42−. Bioassay methane production was greatest at the upper interface of the Flowers-Goodale coal bed near the overlying sandstone. Pyrotag analysis identified Aeribacillus as a dominant in situbacterial community member in the coal near the sandstone and statistical analysis indicated Actinobacteria predominated coal core samples compared to claystone or sandstone cores. These bacteria, which previously have been correlated with hydrocarbon-containing environments such as oil reservoirs, have demonstrated the ability to produce biosurfactants to break down

  11. Scale-up of an electrical capacitance tomography sensor for imaging pharmaceutical fluidized beds and validation by computational fluid dynamics

    Science.gov (United States)

    Wang, Haigang; Yang, Wuqiang

    2011-10-01

    The aim of this research is to apply electrical capacitance tomography (ECT) in pharmaceutical fluidized beds and scale up the application of ECT from a lab-scale fluidized bed to a production-scale fluidized bed. The objective is to optimize the design of the production-scale fluidized bed and to improve the operation efficiency of the fluidization processes. This is the first time that ECT has been scaled up to a production-scale fluidized bed of 1.0 m diameter and batch process capacity of 100 kg in a real industrial environment. With a large-scale fluidized bed in a real industrial environment, some key issues on the ECT sensor design must be addressed. To validate ECT measurement results, a two-phase flow model has been used to simulate the process in a lab-scale and pilot-scale fluidized bed. The key process parameters include solid concentration, average concentration profiles, the frequency spectrum of signal fluctuation obtained by the fast Fourier transfer (FFT) and multi-level wavelet decomposition in the time domain. The results show different hydrodynamic behaviour of fluidized beds of different scales. The time-averaged parameters from ECT and computational fluid dynamics are compared. Future work on the ECT sensor design for large-scale fluidized beds are given in the end of the paper.

  12. Experimental investigation of thermal conductivity coefficient and heat exchange between fluidized bed and inclined exchange surface

    Directory of Open Access Journals (Sweden)

    B. Stojanovic

    2009-06-01

    Full Text Available The paper presents experimental research of thermal conductivity coefficients of the siliceous sand bed fluidized by air and an experimental investigation of the particle size influence on the heat transfer coefficient between fluidized bed and inclined exchange surfaces. The measurements were performed for the specific fluidization velocity and sand particle diameters d p=0.3, 0.5, 0.9 mm. The industrial use of fluidized beds has been increasing rapidly in the past 20 years owing to their useful characteristics. One of the outstanding characteristics of a fluidized bed is that it tends to maintain a uniform temperature even with nonuniform heat release. On the basis of experimental research, the influence of the process's operational parameters on the obtained values of the bed's thermal conductivity has been analyzed. The results show direct dependence of thermal conductivity on the intensity of mixing, the degree of fluidization, and the size of particles. In the axial direction, the coefficients that have been treated have values a whole order higher than in the radial direction. Comparison of experimental research results with experimental results of other authors shows good agreement and the same tendency of thermal conductivity change. It is well known in the literature that the value of the heat transfer coefficient is the highest in the horizontal and the smallest in the vertical position of the heat exchange surface. Variation of heat transfer, depending on inclination angle is not examined in detail. The difference between the values of the relative heat transfer coefficient between vertical and horizontal heater position for all particle sizes reduces by approximately 15% with the increase of fluidization rate.

  13. Investigation of hydrodynamics and heat transfer in pseudo 2D spouted beds with and without draft plates

    Directory of Open Access Journals (Sweden)

    S. H. Hosseini

    Full Text Available Abstract In the present study, hydrodynamics and gas to particle heat transfer in pseudo two dimensional spouted beds (2DSB with and without draft plates were investigated using the Eulerian-Eulerian approach. The main objective of the study was to provide an understanding of effects of the presence of draft plates on the hydrodynamics and heat transfer behavior of solid particles in the spouted beds. To validate the model, the predicted mean particle vertical velocity at the bed axis, the lateral profiles of vertical particle velocity at different bed heights for both systems, and the particle velocity vector fields in the beds were compared with the experimental measurements. A close agreement between the CFD results and the experimental data was found for both systems. The simulation results showed that the particle volume fraction in the spout and fountain regions of the spouted bed with draft plates is considerably lower than that in a conventional spouted bed (without draft plates. Simulation results also showed significant differences between the temperature distributions of gas and solid phases in spouted beds with and without draft plates.

  14. Innovative rock bed construction

    Energy Technology Data Exchange (ETDEWEB)

    Cook, J.

    1983-06-01

    A general discussion of the use of rock beds for heating and cooling thermal storage is particularized for design and construction in Phoenix, Arizona. The rock bed parameters for three two-story condominium apartments constructed in 1982 are discussed, including sizing criteria and original construction details. A revised construction method using gabions that are self-supporting chain link cylinders provided a much more economical construction method as well as other advantages of speed and structural flexibility.

  15. Radiotherapy confined to the tumor bed following breast conserving surgery. Current status, controversies, and future prospects

    Energy Technology Data Exchange (ETDEWEB)

    Polgar, C.; Fodor, J.; Major, T.; Takacsi-Nagy, Z.; Nemeth, G. [National Institut of Oncology, Department of Radiotherapy, Budapest (Hungary); Kasler, M. [Semmelweis University Budapest, Chair of Oncology, Budapest (Hungary); Hammer, J. [Barmherzige Schwestern Hospital, Department of Radiation Oncology, Linz (Austria); Limbergen, E. van [University Ziekenhuizen, Department of Radiation Oncology, Leuven (Belgium)

    2002-11-01

    The aim of this study was to review the current status, controversies, and future prospects of tumor bed irradiation alone after breast conserving surgery. Material and Methods: Published prospective trials evaluating the feasibility and efficacy of radiotherapy confined to the tumor bed following breast conserving surgery were reviewed in order to analyze treatment results. Results: In three earlier studies, using tumor bed radiotherapy for unselected patients, the incidence of intra-breast relapse was reported in the range of 15.6-37%. However, in nine prospective phase I-II trials, sole brachytherapy (BT) with different dose rates, strict patients selection, and meticulous quality assurance, resulted in 95.6-100% local control rates. To date, only one phase III protocol has been initiated comparing the efficacy of tumor bed brachytherapy alone with conventional whole breast radiotherapy. The ideal extent of the planning target volume (PTV) for tumor bed radiotherapy alone has not been established yet. In most series, PTV was defined as the excision cavity with generous (1-3 cm) safety margins. Minimal requirement for PTV localization is the use of titanium clips to mark the walls of the excision cavity intraoperatively, but the combination of clip demarcation and three-dimensional (3-D) visual information obtained from cross-sectional images seems to be the best method to determine the target volume. 3-D virtual brachytherapy is also a promising method to minimize the chance of geographic miss. Recently developed techniques, such as intraoperative radiotherapy (IORT), as well as accelerated 3-D conformal external beam radiation therapy (3-D-CRT) were also found to be feasible for tumor bed radiotherapy alone. Conclusions: In spite of the existing arguments against limiting radiotherapy to the tumor bed after breast conserving surgery, results of phase I-II studies suggest that tumor bed radiotherapy alone might be an appropriate treatment option for selected

  16. A review of dryout heat fluxes and coolability of particle beds. APRI 4, Stage 2 Report

    International Nuclear Information System (INIS)

    Lindholm, Ilona

    2002-04-01

    Dryout heat flux experiments on particle beds have been reviewed. The observed dryout heat flux varies from some tens of kW/m 2 to well over 1 MW/m 2 . The variation can be qualitatively and to some extent also quantitatively explained. The effect of particle diameter has been clearly demonstrated. For particles having diameter less than about 1 mm, the dryout heat flux on the order of 100-200 kW/m 2 , and increases on square of the particle diameter. For larger than 1 mm particles the dryout heat flux increases on square root of the particle diameter. Typical values for ∼ 5 mm particles is 500 kW/m 2 to 1 MW/m 2 . An effect of bed thickness can be seen for small particles and medium range (50-500 mm) beds. For thick beds, > 500 mm, the dryout heat flux does not any more change as the bed height increases. The dryout heat flux increases with increasing coolant pressure. This can be explained by the increasing vapour density, which can remove more latent heat from the bed. Debris bed stratification, with small particles on top, clearly decreases the dryout heat flux. The dryout heat flux in a stratified bed can even be smaller than a heat flux of an equivalent debris bed consisting of the smaller particles alone. This is due to the capillary force, which draws liquid towards the smaller particles and causes the dryout to occur at the interface of the particle layers. A model has been developed by Lipinski to estimate dryout heat fluxes in a particle bed. The model has been derived based on solution of momentum, energy and mass conservation equations for two phases. The 1-D model can take into account variable particle sizes (stratification) along the bed and different coolant entry positions. It has been shown that the model can quite well predict the observed dryout characteristics in most experiments. The simpler 0-D model can give reasonable estimates for non-stratified beds. Results and observations of several tests on melt jet fragmentation in a water pool

  17. Bed rest during pregnancy

    Science.gov (United States)

    ... Belizán JM, Bergel E. Bed rest in singleton pregnancies for preventing preterm birth. Cochrane Database ... and Gynecology, Loma Linda University School of Medicine, Loma Linda Center for Fertility, ...

  18. Enuresis (Bed-Wetting)

    Science.gov (United States)

    ... Symptoms of enuresis Enuresis is when an older child (age 7 or older) wets the bed at night ... feel guilt and embarrassment. It’s true that your child should take responsibility for bedwetting. He or she could do this ...

  19. Particle fuel bed tests

    International Nuclear Information System (INIS)

    Horn, F.L.; Powell, J.R.; Savino, J.M.

    1985-01-01

    Gas-cooled reactors, using packed beds of small diameter coated fuel particles have been proposed for compact, high-power systems. The particulate fuel used in the tests was 800 microns in diameter, consisting of a thoria kernel coated with 200 microns of pyrocarbon. Typically, the bed of fuel particles was contained in a ceramic cylinder with porous metallic frits at each end. A dc voltage was applied to the metallic frits and the resulting electric current heated the bed. Heat was removed by passing coolant (helium or hydrogen) through the bed. Candidate frit materials, rhenium, nickel, zirconium carbide, and zirconium oxide were unaffected, while tungsten and tungsten-rhenium lost weight and strength. Zirconium-carbide particles were tested at 2000 K in H 2 for 12 hours with no visible reaction or weight loss

  20. Exchange between the stagnant and flowing zone in gas-flowing solids-fixed bed contactors

    Directory of Open Access Journals (Sweden)

    ALEKSANDAR P. DUDUKOVIC

    2005-02-01

    Full Text Available In countercurrent gas – flowing solids – fixed bed contactors, a fraction of the flowing solids is in motion (dynamic holdup, while the other fraction is resting on the fixed bed elements. In this study it was experimentally proved that the stagnant zone should not be considered as a dead part of the column, but that there is a dynamic exchange between these two portions of flowing solids particles. Combining a mathematical model with tracer experiments, the rate of exchange was determined and it was shown that only a small part (ca. 20 % of the stagnant region should be considered as a dead one.

  1. Permeability restoration and lowering of uranium leakage from leached ore beds

    International Nuclear Information System (INIS)

    Burgman, H.A.; Grant, D.C.

    1981-01-01

    The injection of an ammonium sulfite or bisulfite solution increases the permeability of an uranium ore bed that has suffered permeability losses during the in-situ mining of uranium with an alkaline leach solution containing a peroxide or dissolved oxygen oxidant. Such an injection recovers much of the lost formation permeability, thus decreasing costs and effort required to put needed restoration solutions or further leach solutions through the ore bed. In addition, uranium contamination of the ground water normally occurring after cessation of leaching is significantly lowered by such injection

  2. Experimental study and Monte Carlo modeling of object motion in a bubbling fluidized bed

    OpenAIRE

    García Gutiérrez, Luis Miguel

    2014-01-01

    Mención Internacional en el título de doctor Fluidized beds are employed for a wide variety of applications such as drying, coating of particles, catalytic reactions, or thermal conversion processes. In a number of these applications, objects differing in density and/or size from the dense phase material are found in the bed. These objects can be agglomerates, catalysts or reactants. In this PhD thesis, a fundamental study of the motion of objects is presented, but consideri...

  3. The East Africa Oligocene intertrappean beds: Regional distribution, depositional environments and Afro/Arabian mammal dispersals

    Science.gov (United States)

    Abbate, Ernesto; Bruni, Piero; Ferretti, Marco Peter; Delmer, Cyrille; Laurenzi, Marinella Ada; Hagos, Miruts; Bedri, Omar; Rook, Lorenzo; Sagri, Mario; Libsekal, Yosief

    2014-11-01

    The extensive outpouring of the Oligocene Trap basalts over eastern Africa and western Arabia was interrupted by a period of quiescence marked by the deposition of terrestrial sediments. These so-called intertrappean beds are often lignitiferous and yield recurrent floras and faunas, sometimes represented by endemic mammals. We intended to highlight the peculiar features of these sedimentary intercalations using a large-scale approach including eastern Africa and the western Arabian peninsula. Starting from a new mapping in the Eritrean highland, the intertrappean beds resulted a continuous level that was a few tens of meters thick and traceable for some tens of kilometers. They consist of fluvial red, green and gray mudstones and siltstones with subordinate channelized pebbly sandstones, and lignite seams. Two new 40Ar-39Ar datings constraint the age of the intertrappean beds between 29.0 Ma and 23.6 Ma. The outcrops near Mendefera have yielded the remains of two proboscidean families, the Deinotheriidae and the Gomphoteriidae. The morphological grade of the two Mendefera proboscideans would suggest a more derived stage than that of representatives of the same families from other Oligocene African sites (e.g., Chilga, Ethiopia). An Oligocene age could be inferred for them. The occurrence of the genus Prodeinotherium at Mai Gobro possibly represents the first occurrence of this taxon, while the Gomphotheirum sp. might represent the oldest occurrence of this taxon in Africa before its dispersal towards Asia and Europe. Proboscideans have also been found in the lowland intertrappean beds of Dogali near Massawa. These sediments were contiguous with the Eritrean highland intertrappean beds during the Oligocene, but are now tectonically displaced from them by two thousand meters of vertical topographical distance. Dogali is also known for the occurrence of possible Deinotheriidae remains and the primitive elephantoid Eritreum. Entering the Ethiopian highland, an

  4. A laboratory study of sex- and stage-related mortality and morbidity in bed bugs (hemiptera: cimicidae) exposed to deltamethrin

    Science.gov (United States)

    Exposure of a pyrethroid-susceptible strain of bed bugs, Cimex lectularius L. (Hemiptera: Cimicidae) to varying concentrations of deltamethrin for 24h indicated there was no significant difference in mortality between males, females, and nymphs at 24h or 168h post-exposure. Most bed bugs classified ...

  5. CLC in packed beds using syngas and CuO/Al2O3: model description and experimental validation

    NARCIS (Netherlands)

    Hamers, H.P.; Gallucci, F.; Cobden, P.D.; Kimball, E.; Sint Annaland, M. van

    2014-01-01

    The objective of this work is to study the performance of the oxygen carrier in a packed bed with periodic switching between oxidizing and reducing conditions. In this paper the performance of CuO/Al2O3 as the oxygen carrier in a packed bed reactor with syngas as the fuel are investigated, while

  6. Natural fabric sandwich laminate composites: development and ...

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 40; Issue 1 ... Natural fabrics; jute; linen; sandwich laminate; mechanical properties; fractographic analysis. ... In this work, eco-friendly natural fabric sandwich laminate (NFSL) composites are formulated using jute and linen-fabric-reinforced epoxy with different layer ...

  7. Contraction rate, flow modification and bed layering impact on scour at the elliptical guide banks

    Science.gov (United States)

    Gjunsburgs, B.; Jaudzems, G.; Bizane, M.; Bulankina, V.

    2017-10-01

    Flow contraction by the bridge crossing structures, intakes, embankments, piers, abutments and guide banks leads to general scour and the local scour in the vicinity of the structures. Local scour is depending on flow, river bed and structures parameters and correct understanding of the impact of each parameter can reduce failure possibility of the structures. The paper explores hydraulic contraction, the discharge redistribution between channel and floodplain during the flood, local flow modification and river bed layering on depth, width and volume of scour hole near the elliptical guide banks on low-land rivers. Experiments in a flume, our method for scour calculation and computer modelling results confirm a considerable impact of the contraction rate of the flow, the discharge redistribution between channel and floodplain, the local velocity, backwater and river bed layering on the depth, width, and volume of scour hole in steady and unsteady flow, under clear water condition. With increase of the contraction rate of the flow, the discharge redistribution between channel and floodplain, the local velocity, backwater values, the scour depth increases. At the same contraction rate, but at a different Fr number, the scour depth is different: with increase in the Fr number, the local velocity, backwater, scour depth, width, and volume is increasing. Acceptance of the geometrical contraction of the flow, approach velocity and top sand layer of the river bed for scour depth calculation as accepted now, may be the reason of the structures failure and human life losses.

  8. Optimum process design of packed bed type thermal storage systems and other applications

    Science.gov (United States)

    Bindra, Hitesh; Bueno, Pablo

    2016-10-25

    Methods and systems for optimizing the process of heat and/or mass transfer operations in packed beds and embodiments of applications of the methods are disclosed herein below. In one instance, the method results in the profile of the quantity representative of the heat and/or mass transfer operation having a propagating substantially sharp front.

  9. Dynamic behavior and control requirements of an atmospheric fluidized-bed coal combustion power plant: A conceptual study

    Energy Technology Data Exchange (ETDEWEB)

    Smith, O.L.

    1987-06-01

    A first-principles model of a nominal 20-MW atmospheric-pressure fluidized-bed coal combustion (AFBC) power plant was developed to provide insight into fundamental dynamic behavior of fluidized-bed systems. The control system included major loops for firing rate, steam pressure and temperature, forced and induced draft air flow, SO/sub 2/ emission, drum water level, evaporator recirculation, and bed level. The model was used to investigate system sensitivity to design features such as the distribution of heat transfer surface among the bed boiler and superheater and the out-of-bed superheater. Also calculated were the sensitivities of temperatures, pressures, and flow rates to changes in throttle, attemperator, and feedwater valve settings and forced and induced draft damper settings. The large bed mass, accounting for approx.40% of the active heat capacity, may vary under load change and could impact controller tuning. Model analysis indicated, however, that for the design studied, the change in bed mass does not appear to significantly affect controller tuning even if the bed mass varies appreciably under load-following conditions. Several bed designs are being considered for AFBC plants, some with partitions between bed sections and some without, and these differences may significantly affect the load-following capability of the plant. The results indicated that the slumping mode of operation can cause distortion of the heat source/sink distribution in the bed such that the load-following capability (rate of load change) of the plant may be reduced by as much as a factor of 5 compared with the mode in which tube surface is exposed. 9 refs., 13 figs., 6 tabs.

  10. Aeolian Sand Transport in the Planetary Context: Respective Roles of Aerodynamic and Bed-Dilatancy Thresholds

    Science.gov (United States)

    Marshall, J. R.; Borucki, J.; Bratton, C.

    1999-09-01

    The traditional view of aeolian sand transport generally estimates flux from the perspective of aerodynamic forces creating the airborne grain population, although it has been recognized that "reptation" causes a significant part of the total airborne flux; reptation involves both ballistic injection of grains into the air stream by the impact of saltating grains as well as the "nudging" of surface grains into a creeping motion. Whilst aerodynamic forces may initiate sand motion, it is proposed here that within a fully-matured grain cloud, flux is actually governed by two thresholds: an aerodynamic threshold, and a bed-dilatancy threshold. It is the latter which controls the reptation population, and its significance increases proportionally with transport energy. Because we only have experience with terrestrial sand transport, extrapolations of aeolian theory to Mars and Venus have adjusted only the aerodynamic factor, taking gravitational forces and atmospheric density as the prime variables in the aerodynamic equations, but neglecting reptation. The basis for our perspective on the importance of reptation and bed dilatancy is a set of experiments that were designed to simulate sand transport across the surface of a martian dune. Using a modified sporting crossbow in which a sand-impelling sabot replaced the bolt-firing mechanism, individual grains of sand were fired at loose sand targets with glancing angles typical of saltation impact; grains were projected at about 80 m/s to simulate velocities commensurate with those predicted for extreme martian aeolian conditions. The sabot impelling method permitted study of individual impacts without the masking effect of bed mobilization encountered in wind-tunnel studies. At these martian impact velocities, grains produced small craters formed by the ejection of several hundred grains from the bed. Unexpectedly, the craters were not elongated, despite glancing impact; the craters were very close to circular in planform

  11. Suitability of biocompost as a bedding material for stabled horses: respiratory hygiene and management practicalities.

    Science.gov (United States)

    Seedorf, J; Schröder, M; Köhler, L; Hartung, J

    2007-03-01

    Bedding material in stables has an important influence on air hygiene and information on the suitability of biocompost and wood shavings is incomplete. To compare the suitability and benefit of biocompost and wood shavings as bedding in horse stables and to determine key air factors for the evaluation of the potential impact of these materials on respiratory health. The study was conducted in a naturally ventilated stable with 4 horses. Air hygiene parameters were measured 24 h/day for 7 days with each bedding type: ammonia (NH3), inhalable and respirable dust, endotoxins, colony forming units (CFU) of total mesophilic bacteria, fungi, actinomycetes and thermophilic actinomycetes. Both bedding materials were analysed for general chemical composition, particle size distribution and natural microbial content. The animals' behaviour was monitored by video cameras, and their health and cleanliness status determined by clinical and visual examination. Concentrations of NH3, dust, endoxins and fungi were significantly higher during the monitoring period with wood shavings than with biocompost. In contrast concentrations of mesophilic bacteria, mesophilic actinomycetes and thermophilic actinomycetes microbial pollutants were highest with biocompost. The water content of bulk biocompost was considerably higher than that of wood shavings. Particles market.

  12. Sedimentological analysis and bed thickness statistics from a Carboniferous deep-water channel-levee complex: Myall Trough, SE Australia

    Science.gov (United States)

    Palozzi, Jason; Pantopoulos, George; Maravelis, Angelos G.; Nordsvan, Adam; Zelilidis, Avraam

    2018-02-01

    This investigation presents an outcrop-based integrated study of internal division analysis and statistical treatment of turbidite bed thickness applied to a Carboniferous deep-water channel-levee complex in the Myall Trough, southeast Australia. Turbidite beds of the studied succession are characterized by a range of sedimentary structures grouped into two main associations, a thick-bedded and a thin-bedded one, that reflect channel-fill and overbank/levee deposits, respectively. Three vertically stacked channel-levee cycles have been identified. Results of statistical analysis of bed thickness, grain-size and internal division patterns applied on the studied channel-levee succession, indicate that turbidite bed thickness data seem to be well characterized by a bimodal lognormal distribution, which is possibly reflecting the difference between deposition from lower-density flows (in a levee/overbank setting) and very high-density flows (in a channel fill setting). Power law and exponential distributions were observed to hold only for the thick-bedded parts of the succession and cannot characterize the whole bed thickness range of the studied sediments. The succession also exhibits non-random clustering of bed thickness and grain-size measurements. The studied sediments are also characterized by the presence of statistically detected fining-upward sandstone packets. A novel quantitative approach (change-point analysis) is proposed for the detection of those packets. Markov permutation statistics also revealed the existence of order in the alternation of internal divisions in the succession expressed by an optimal internal division cycle reflecting two main types of gravity flow events deposited within both thick-bedded conglomeratic and thin-bedded sandstone associations. The analytical methods presented in this study can be used as additional tools for quantitative analysis and recognition of depositional environments in hydrocarbon-bearing research of ancient

  13. The consequences of granulate heterogeneity towards breakage and attrition upon fluid-bed drying

    NARCIS (Netherlands)

    Nieuwmeyer, Florentine; Maarschalk, Kees van der Voort; Vromans, Herman

    High-shear granulated lactose granulates were dried in it fluid-bed dryer at various conditions. Granules were characterized by water content and size analysis. It is shown that the drying process is very dynamic in terms of growth and breakage phenomena. Granular size heterogeneity, composition and

  14. Inoculation of fumigated nursery beds and containers with arbuscular mycorrhizal products for eastern redcedar production

    Science.gov (United States)

    Michelle M. Cram; Stephen W. Fraedrich

    2015-01-01

    Commercially available arbuscular mycorrhizal (AM) products were applied at an operational rate to eastern redcedar (Juniperus virginiana L.) nursery beds and containers to evaluate seedling growth and colonization responses. A field study at the Augusta Forestry Center in Crimora, VA, and a companion container study were initiated in the fall of 2012. MycoApply® Endo...

  15. Coal-bed methane water effects on dill and essential oils

    Science.gov (United States)

    Pumping water from coal seams decreases the pressure in the seam and in turn releases trapped methane; this is the most common and economic way of methane extraction. The water that is pumped out is known as coal-bed methane water (CBMW), which is high in sodium and other salts. In past 25 years, th...

  16. The association between number of doctors per bed and readmission of elderly patients with pneumonia in South Korea.

    Science.gov (United States)

    Lee, Joo Eun; Kim, Tae Hyun; Cho, Kyoung Hee; Han, Kyu-Tae; Park, Eun-Cheol

    2017-06-08

    There is an urgent need to reduce readmission of patients with pneumonia and improve quality of care. To assess the association between hospital resources and quality of care, we examined the effect of number of doctors per bed on 30-day readmission and investigated the combined effect of number of doctors per bed and number of beds. We used nationwide cohort sample data of health insurance claims by the National Health Insurance Service (NHIS) from 2002 to 2013. Pneumonia admissions to acute care hospitals among 7446 inpatients older than 65 were examined. We conducted a multivariate Cox proportional hazard model to analyze the association between the number of doctors per bed and 30-day readmission, as well as that of pneumonia-specific 30-day readmission with the combined effects of number of doctors per bed and number of beds. Overall, 1421 (19.1%) patients were readmitted within 30 days and 756 (11.2%) patients were readmitted for pneumonia within 30 days. Patients with pneumonia treated by very low or low number of doctors per bed showed higher readmission (pneumonia-specific readmission: hazard ratio [HR] = 1. 406, 95% confidence interval [CI] = 1.072-1.843 for low number of doctors per bed; all-cause readmissions: HR = 1.276, 95% CI = 1.026-1.587 for very low number of doctors per bed, and HR = 1.280, 95% CI = 1.064-1.540 for low number of doctors per bed). This empirical study showed that patients with pneumonia cared for in hospitals with more doctors were less likely to be readmitted. Pneumonia-specific 30-day readmission was also significantly associated with the combined effect of the number of doctors and the number of hospital beds.

  17. ELECTRODEPOSITION OF COPPER IONS ON FIXED BED ELECTRODES: KINETIC AND HYDRODYNAMIC STUDY

    Directory of Open Access Journals (Sweden)

    L.A.M. Ruotolo

    2002-03-01

    Full Text Available The kinetic and hydrodynamic behaviour of a fixed-bed electrochemical reactor was studied in terms of current efficiency (CE and energy efficiency (EE. In the kinetic experiments the effects of fixed bed thickness (L, current density (i and initial concentration of copper (C0 were studied. In the hydrodynamic experiments the permeability (k of the electrode and the coefficient for inertial forces (c were also studied as functions of the applied current density. At low current densities and bed thicknesses greater than 1.0 cm, negative CE and EE were observed as a consequence of the dissolution of the porous matrix. At high current densities low CE and EE were observed and a powdery deposit was formed on the surface of the particles. From the results of the kinetic study bed thickness and the range of current densities employed in the hydrodynamic experiments were chosen. In these experiments the electrodeposition process continued until the whole electrode had been clogged and no more electrolyte could pass through it. The relationship between pressure drop and flow rate was well described by the Forchheimer equation. It was observed that the reduction in porosity due to copper electrodeposition causes the flow rate to decrease because of the decrease in electrode permeability, but it had no influence on current efficiency.

  18. Enabling Smart Manufacturing Research and Development using a Product Lifecycle Test Bed.

    Science.gov (United States)

    Helu, Moneer; Hedberg, Thomas

    2015-01-01

    Smart manufacturing technologies require a cyber-physical infrastructure to collect and analyze data and information across the manufacturing enterprise. This paper describes a concept for a product lifecycle test bed built on a cyber-physical infrastructure that enables smart manufacturing research and development. The test bed consists of a Computer-Aided Technologies (CAx) Lab and a Manufacturing Lab that interface through the product model creating a "digital thread" of information across the product lifecycle. The proposed structure and architecture of the test bed is presented, which highlights the challenges and requirements of implementing a cyber-physical infrastructure for manufacturing. The novel integration of systems across the product lifecycle also helps identify the technologies and standards needed to enable interoperability between design, fabrication, and inspection. Potential research opportunities enabled by the test bed are also discussed, such as providing publicly accessible CAx and manufacturing reference data, virtual factory data, and a representative industrial environment for creating, prototyping, and validating smart manufacturing technologies.

  19. Enabling Smart Manufacturing Research and Development using a Product Lifecycle Test Bed

    Science.gov (United States)

    Helu, Moneer; Hedberg, Thomas

    2017-01-01

    Smart manufacturing technologies require a cyber-physical infrastructure to collect and analyze data and information across the manufacturing enterprise. This paper describes a concept for a product lifecycle test bed built on a cyber-physical infrastructure that enables smart manufacturing research and development. The test bed consists of a Computer-Aided Technologies (CAx) Lab and a Manufacturing Lab that interface through the product model creating a “digital thread” of information across the product lifecycle. The proposed structure and architecture of the test bed is presented, which highlights the challenges and requirements of implementing a cyber-physical infrastructure for manufacturing. The novel integration of systems across the product lifecycle also helps identify the technologies and standards needed to enable interoperability between design, fabrication, and inspection. Potential research opportunities enabled by the test bed are also discussed, such as providing publicly accessible CAx and manufacturing reference data, virtual factory data, and a representative industrial environment for creating, prototyping, and validating smart manufacturing technologies. PMID:28664167

  20. BedMachine v3: Complete Bed Topography and Ocean Bathymetry Mapping of Greenland From Multibeam Echo Sounding Combined With Mass Conservation.

    Science.gov (United States)

    Morlighem, M; Williams, C N; Rignot, E; An, L; Arndt, J E; Bamber, J L; Catania, G; Chauché, N; Dowdeswell, J A; Dorschel, B; Fenty, I; Hogan, K; Howat, I; Hubbard, A; Jakobsson, M; Jordan, T M; Kjeldsen, K K; Millan, R; Mayer, L; Mouginot, J; Noël, B P Y; O'Cofaigh, C; Palmer, S; Rysgaard, S; Seroussi, H; Siegert, M J; Slabon, P; Straneo, F; van den Broeke, M R; Weinrebe, W; Wood, M; Zinglersen, K B

    2017-11-16

    Greenland's bed topography is a primary control on ice flow, grounding line migration, calving dynamics, and subglacial drainage. Moreover, fjord bathymetry regulates the penetration of warm Atlantic water (AW) that rapidly melts and undercuts Greenland's marine-terminating glaciers. Here we present a new compilation of Greenland bed topography that assimilates seafloor bathymetry and ice thickness data through a mass conservation approach. A new 150 m horizontal resolution bed topography/bathymetric map of Greenland is constructed with seamless transitions at the ice/ocean interface, yielding major improvements over previous data sets, particularly in the marine-terminating sectors of northwest and southeast Greenland. Our map reveals that the total sea level potential of the Greenland ice sheet is 7.42 ± 0.05 m, which is 7 cm greater than previous estimates. Furthermore, it explains recent calving front response of numerous outlet glaciers and reveals new pathways by which AW can access glaciers with marine-based basins, thereby highlighting sectors of Greenland that are most vulnerable to future oceanic forcing.

  1. Alarm pheromones and chemical communication in nymphs of the tropical bed bug Cimex hemipterus (Hemiptera: Cimicidae.

    Directory of Open Access Journals (Sweden)

    H Christoph Liedtke

    Full Text Available The recent resurge of bed bug infestations (Cimex spp.; Cimicidae and their resistance to commonly used pesticides calls for alternative methods of control. Pheromones play an important role in environmentally sustainable methods for the management of many pest insects and may therefore be applicable for the control of bed bugs. The tropical bed bug, Cimex hemipterus, is a temporary ectoparasite on humans and causes severe discomfort. Compared to the common bed bug, Cimex lectularius, little is known about the chemical signalling and pheromone-based behaviour of the tropical species. Here, we show that the antennal morphology and volatile emission of C. hemipterus closely resembles those of C. lectularius and we test their behavioural responses to conspecific odour emissions. Two major volatiles are emitted by male, female and nymph C. hemipterus under stress, (E-2-hexenal and (E-2-octenal. Notably, nymph emissions show contrasting ratios of these compounds to adults and are further characterized by the addition of 4-oxo-(E-2-hexenal and 4-oxo-(E-2-octenal. The discovery of this nymph pheromone in C. hemipterus is potentially the cause of a repellent effect observed in the bio-tests, where nymph odours induce a significantly stronger repellent reaction in conspecifics than adult odours. Our results suggest that pheromone-based pest control methods developed for C. lectularius could be applicable to C. hemipterus, with the unique nymph blend showing promising practical properties.

  2. Feasibility and safety of in-bed cycling for physical rehabilitation in the intensive care unit.

    Science.gov (United States)

    Kho, Michelle E; Martin, Robert A; Toonstra, Amy L; Zanni, Jennifer M; Mantheiy, Earl C; Nelliot, Archana; Needham, Dale M

    2015-12-01

    The purpose was to evaluate the feasibility and safety of in-bed cycle ergometry as part of routine intensive care unit (ICU) physical therapist (PT) practice. Between July 1, 2010, and December 31, 2011, we prospectively identified all patients admitted to a 16-bed medical ICU receiving cycling by a PT, prospectively collected data on 12 different potential safety events, and retrospectively conducted a chart review to obtain specific details of each cycling session. Six hundred eighty-eight patients received PT interventions, and 181 (26%) received a total of 541 cycling sessions (median [interquartile range {IQR}] cycling sessions per patient, 2 [1-4]). Patients' mean (SD) age was 57 (17) years, and 103 (57%) were male. The median (IQR) time from medical ICU admission to first PT intervention and first cycling session was 2 (1-4) and 4 (2-6) days, respectively, with a median (IQR) cycling session duration of 25 (18-30) minutes. On cycling days, the proportion of patients receiving mechanical ventilation, vasopressor infusions, and continuous renal replacement therapy was 80%, 8%, and 7%, respectively. A single safety event occurred, yielding a 0.2% event rate (95% upper confidence limit, 1.0%). Use of in-bed cycling as part of routine PT interventions in ICU patients is feasible and appears safe. Further study of the potential benefits of early in-bed cycling is needed. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Breakup and reestablishment of the armour layer in a large gravel-bed river below dams: The lower Ebro

    Science.gov (United States)

    Vericat, Damia; Batalla, Ramon J.; Garcia, Celso

    2006-06-01

    Changes in armour layer during floods under supply limited conditions are little known. This paper describes the breakup and the reestablishment of the bed armour layer in the regulated gravel-bed Ebro River during a flooding period. The study was conducted over a 28-km study reach from 2002 to 2004. The surface, subsurface and bed load grain size distribution constitute the bases for the analysis of bed-armouring dynamics. The results indicate that the magnitude of floods controlled the degree of armouring of the river bed. The initial mean armouring ratio was 2.3, with maximum values reaching 4.4. Floods in the winter of 2002-2003 ( Q8) caused the breakup of the armour layer in several sections. This resulted in the erratic bed load pattern observed during the December 2002 flushing flow and in the increase in bed load transport during successive events. Most grain size classes were entrained and transported, causing river bed incision. The mean armouring ratio decreased to 1.9. In contrast, during low magnitude floods in 2003-2004 ( Q2), the coarsest fractions (64 mm) did not take part in the bed load while finer particles were winnowed, thus surface deposits coarsened. As a result, the armour layer was reestablished (i.e., the mean armouring ratio increased to 2.3), and the supply of subsurface sediment decreased. The supply and transport of bed material appear to be in balance in the river reach immediately below the dam. In contrast, the transport of medium and finer size classes in the downstream reaches was higher than their supply from upstream, a phenomenon that progressively reduced their availability in the river bed surface, hence the armour layer reworking.

  4. Techniques of tumour bed boost irradiation in breast conserving therapy: Current evidence and suggested guidelines

    Energy Technology Data Exchange (ETDEWEB)

    Jalali, Rakesh; Singh, Suruchi; Budrukkar, Ashwini [Tata Memorial Hospital, Mumbai (India)

    2007-10-15

    Breast conservation surgery followed by external beam radiotherapy to breast has become the standard of care in management of early carcinoma breast. A boost to the tumour bed after whole breast radiotherapy is employed in view of the pattern of tumour bed recurrences in the index quadrant and was particularly considered in patients with some adverse histopathological characteristics such as positive margins, extensive intraductal carcinoma (EIC), lymphovascular invasion (LVI), etc. There is however, now, a conclusive evidence of improvement in local control rates after a boost radiotherapy dose in patients even without such factors and for all age groups. The maximum absolute reduction of local recurrences by the addition of boost is especially seen in young premenopausal patients. At the same time, the addition of boost is associated with increased risk of worsening of cosmesis and no clear cut survival advantage. Radiological modalities such as fluoroscopy, ultrasound and CT scan have aided in accurate delineation of tumour bed with increasing efficacy. A widespread application of these techniques might ultimately translate into improved local control with minimal cosmetic deficit. The present article discusses the role of radiotherapy boost and the means to delineate and deliver the same, identify the high risk group, optimal technique and the doses and fractionations to be used. It also discusses the extent of adverse cosmetic outcome after boost delivery, means to minimise it and relevance of tumour bed in present day scenario of advanced radiotherapy delivery techniques like (IMRT)

  5. X-ray computed tomography of packed bed chromatography columns for three dimensional imaging and analysis.

    Science.gov (United States)

    Johnson, T F; Levison, P R; Shearing, P R; Bracewell, D G

    2017-03-03

    Physical characteristics critical to chromatography including geometric porosity and tortuosity within the packed column were analysed based upon three dimensional reconstructions of bed structure in-situ. Image acquisition was performed using two X-ray computed tomography systems, with optimisation of column imaging performed for each sample in order to produce three dimensional representations of packed beds at 3μm resolution. Two bead materials, cellulose and ceramic, were studied using the same optimisation strategy but resulted in differing parameters required for X-ray computed tomography image generation. After image reconstruction and processing into a digital three dimensional format, physical characteristics of each packed bed were analysed, including geometric porosity, tortuosity, surface area to volume ratio as well as inter-bead void diameters. Average porosities of 34.0% and 36.1% were found for ceramic and cellulose samples and average tortuosity readings at 1.40 and 1.79 respectively, with greater porosity and reduced tortuosity overall values at the centre compared to the column edges found in each case. X-ray computed tomography is demonstrated to be a viable method for three dimensional imaging of packed bed chromatography systems, enabling geometry based analysis of column axial and radial heterogeneity that is not feasible using traditional techniques for packing quality which provide an ensemble measure. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

  6. Upper Pleistocene turbidite sand beds and chaotic silt beds in the channelized, distal, outer-fan lobes of the Mississippi fan

    Science.gov (United States)

    Nelson, C.H.; Twichell, D.C.; Schwab, W.C.; Lee, H.J.; Kenyon, Neil H.

    1992-01-01

    Cores from a Mississippi outer-fan depositional lobe demonstrate that sublobes at the distal edge contain a complex local network of channelized-turbidite beds of graded sand and debris-flow beds of chaotic silt. Off-lobe basin plains lack siliciclastic coarse-grained beds. The basin-plain mud facies exhibit low acoustic backscatter on SeaMARC IA sidescan sonar images, whereas high acoustic backscatter characteristic of the lobe sand and silt facies. The depth of the first sand-silt layer correlates with relative backscatter intensity and stratigraphic age of the distal sublobes (i.e., shallowest sand = highest backscatter and youngest sublobe). The high proportion (>50%) of chaotic silt compared to graded sand in the distal, outer-fan sublobes may be related to the unstable, muddy, canyon-wall source areas of the extensive Mississippi delta-fed basin slope. A predominace of chaotic silt in cores or outcrops from outer-fan lobes thus may predict similar settings for ancient fans.

  7. Influence of tube and particle diameter on heat transport in packed beds

    NARCIS (Netherlands)

    Borkink, J.G.H.; Borkink, J.G.H.; Westerterp, K.R.

    1992-01-01

    Influence of the tube and particle diameter and shape, as well as their ratio, on the radial heat transport in packed beds has been studied. Heat transport experiments were performed with four different packings in three wall-cooled tubes, which differed in inner diameter only. Experimental values

  8. The fauna and flora of a kelp bed canopy | Allen | African Zoology

    African Journals Online (AJOL)

    The fauna and flora of the canopy of a kelp bed off Oudekraal, on the Cape Peninsula, Is surveyed. Four species of epiphytic algae occur In the kelp canopy, three restricted to Ecklonia maxima and the fourth to Laminaria pallida. Epiphyte biomass is equivalent to 4-9% of host standing crop amongst E. maxima, but less than ...

  9. Fluidised bed gasification of high-ash South African coals: An experimental and modelling study

    CSIR Research Space (South Africa)

    Engelbrecht, AS

    2011-11-01

    Full Text Available The gasification of two high-ash coals were studied using a pilot scale fluidised bed gasifier using oxygen enrich air and steam as the gasification agents. The results of the tests show that the fixed carbon conversion and calorific value increases...

  10. Mathematical modelling and optimization of biomass-plastic fixed-bed downdraft co-gasification process

    Science.gov (United States)

    Donskoy, Igor

    2017-10-01

    Co-gasification of woody biomass and polyethylene is studied using mathematical modeling. The gasification process is downdraft fixed-bed. Comparison of modeling results with some experimental data is made. Influence of biomass/plastic ratio and air equivalence ratio on gasification efficiency is investigated.

  11. Microhabitat Influence on Larval Fish Assemblages Within Vegetated Beds: Implications for Tubenose Goby Detection and Invasion

    Science.gov (United States)

    We examined larval and juvenile fish assemblage structure in relation to microhabitat variables within the St. Louis River estuary, a drowned river mouth of Lake Superior. Fish were sampled in vegetated beds throughout the estuary, across a gradient of vegetation types and densit...

  12. Pleistocene volcanism of Bed I, Olduvai Gorge, Tanzania: chemostratigraphy, sedimentology, and paleoecology

    OpenAIRE

    Habermann, Jörg

    2016-01-01

    Chapter 2 addresses correlation difficulties in Bed I that arise from major lateral facies changes combined with discontinuous exposure using the discriminative power of the chemical composition of major juvenile mineral phases (augite, anorthoclase, plagioclase) from tuffs, volcaniclastic sandstones, siliciclastic units, and lavas. These compositions, obtained from electron probe micro-analysis, are statistically evaluated applying principal component analysis and discriminant analysis to de...

  13. Mathematical modelling and optimization of biomass-plastic fixed-bed downdraft co-gasification process

    Directory of Open Access Journals (Sweden)

    Donskoy Igor

    2017-01-01

    Full Text Available Co-gasification of woody biomass and polyethylene is studied using mathematical modeling. The gasification process is downdraft fixed-bed. Comparison of modeling results with some experimental data is made. Influence of biomass/plastic ratio and air equivalence ratio on gasification efficiency is investigated.

  14. Experimental measurements and numerical modeling of marginal burning in live chaparral fuel beds

    Science.gov (United States)

    X. Zhou; D.R. Weise; S Mahalingam

    2005-01-01

    An extensive experimental and numerical study was completed to analyze the marginal burning behavior of live chaparral shrub fuels that grow in the mountains of southern California. Laboratory fire spread experiments were carried out to determine the effects of wind, slope, moisture content, and fuel characteristics on marginal burning in fuel beds of common...

  15. a novel interconnected fluidised bed for the combined flash pyrolysis of biomass and combustion of char

    NARCIS (Netherlands)

    Janse, A.M.C.; Janse, Arthur M.C.; Biesheuvel, P.M.; Biesheuvel, Pieter Maarten; Prins, W.; van Swaaij, Willibrordus Petrus Maria

    1999-01-01

    A novel system of two adjacent fluidised beds operating in different gas atmospheres and exchanging solids was developed for the combined flash pyrolysis of biomass and combustion of the produced char. Fluidised sand particles (200 μm < dp < 400 μm) are transported from the pyrolysis reactor to the

  16. A novel interconnected fluidised bed for the combined flash pyrolysis of biomass and combustion of char.

    NARCIS (Netherlands)

    Janse, Arthur M.C.; Janse, A.M.C.; Biesheuvel, P.M.; Biesheuvel, Pieter Maarten; Prins, W.; van Swaaij, Willibrordus Petrus Maria

    2000-01-01

    A novel system of two adjacent fluidised beds operating in different gas atmospheres and exchanging solids was developed for the combined flash pyrolysis of biomass and combustion of the produced char. Fluidised sand particles (200 μm < dp < 400 μm) are transported from the pyrolysis reactor to the

  17. Safe design and operation of fluidized-bed reactors: Choice between reactor models

    NARCIS (Netherlands)

    Westerink, E.J.; Westerterp, K.R.

    1990-01-01

    For three different catalytic fluidized bed reactor models, two models presented by Werther and a model presented by van Deemter, the region of safe and unique operation for a chosen reaction system was investigated. Three reaction systems were used: the oxidation of benzene to maleic anhydride, the

  18. Comparison of risks due to HLW and SURF repositories in bedded salt

    International Nuclear Information System (INIS)

    Chu, M.S.Y.; Ortiz, N.R.; Wahi, K.K.

    1983-01-01

    A methodology was developed for use in the analysis of risks from geologic disposal of nuclear wastes. This methodology is applied to two conceptual nuclear waste repositories in bedded salt containing High-Level Waste (HLW) and Spent Un-Reprocessed Fuel (SURF), respectively. A comparison of the risk estimated from the HLW and SURF repositories is presented

  19. A study on one-dimensional and discontinuous river flows with mobile beds

    NARCIS (Netherlands)

    Sieben, A.

    1995-01-01

    This report focusses on discontinuous behaviour of hydraulics and morphology in rivers. The varying widths, slopes and bed levels that can be observed in mountain rivers can induce rapid, or discontinuous changes at a short lengthscale. When present, these discontinuities have a major impact on

  20. FLUIDIZED BED STEAM REFORMING FOR TREATMENT AND IMMOBILIZATION OF LOW-ACTIVITY WASTE

    Energy Technology Data Exchange (ETDEWEB)

    HEWITT WM

    2011-04-08

    This report is one of four reports written to provide background information regarding immobilization technologies remaining under consideration for supplemental immobilization of Hanford's low-activity waste. This paper provides the reader a general understanding of fluidized bed steam reforming and its possible application to treat and immobilize Hanford low-activity waste.

  1. Fluidized Bed Steam Reforming For Treatment And Immobilization Of Low-Activity Waste

    International Nuclear Information System (INIS)

    Hewitt, W.M.

    2011-01-01

    This report is one of four reports written to provide background information regarding immobilization technologies remaining under consideration for supplemental immobilization of Hanford's low-activity waste. This paper provides the reader a general understanding of fluidized bed steam reforming and its possible application to treat and immobilize Hanford low-activity waste.

  2. Fluidised bed gasification of South African coals – experimental results and process integration

    CSIR Research Space (South Africa)

    Engelbrecht, A

    2011-06-01

    Full Text Available high-ash coal from the Waterberg coalfield was tested in a bubbling fluidised bed gasifier at the CSIR using various gasification agents and operating conditions. The results of the tests show that when air and steam are used as the gasification agents...

  3. Bar dynamics and bifurcation evolution in a modelled braided sand-bed river

    NARCIS (Netherlands)

    Schuurman, Filip; Kleinhans, Maarten G.

    2015-01-01

    Morphodynamics in sand-bed braided rivers are associated with simultaneous evolution of mid-channel bars and channels on the braidplain. Bifurcations around mid-channel bars are key elements that divide discharge and sediment. This, in turn, may control the evolution of connected branches, with

  4. Staff and bed distribution in public sector mental health services in ...

    African Journals Online (AJOL)

    Background. The Eastern Cape Province of South Africa is a resource-limited province with a fragmented mental health service. Objective. To determine the current context of public sector mental health services in terms of staff and bed distribution, and how this corresponds to the population distribution in the province.

  5. Bedmap2: improved ice bed, surface and thickness datasets for Antarctica

    DEFF Research Database (Denmark)

    Fretwell, P.; Pritchard, H. D.; Vaughan, D

    2013-01-01

    We present Bedmap2, a new suite of gridded products describing surface elevation, ice-thickness and the seafloor and subglacial bed elevation of the Antarctic south of 60° S. We derived these products using data from a variety of sources, including many substantial surveys completed since the ori...

  6. Evaluation of Heat Shields from RTS Wright Industries Magnesium and Uranium Beds

    CERN Document Server

    Korinko, P S

    2002-01-01

    Heat shields from a factory test of the furnaces that will be used to heat the magnesium and uranium beds for the tritium extraction facility (TEF) were examined to determine the cause of discoloration. The samples were examined using visual, optical microscopy, electron microscopy, x-ray spectroscopy, and Auger electron spectroscopy.

  7. Prospect evaluation of BED 3 and Sitra oilfields, Abu Gharadig Basin, North Western Desert, Egypt

    Science.gov (United States)

    Salem, Ibrahim; Ghazala, Hosni; El Diasty, Waleed

    2015-12-01

    The occurrence of hydrocarbons is closely linked to the elements of petroleum system history of the BED 3 and Sitra 8 oilfields, which has created multiple reservoir and seal combinations. BED 3 Field and Sitra concessions occupy the northwestern part of the Abu Gharadig Basin and extends between latitudes 29°45‧ and 30°05‧N and longitudes 27°30‧ and 28°10‧E. The comprehensive integration of the geo-related data and the interpretation of the well logging, geochemical, seismic data in time domain and depth and sealing mechanisms explain the occurrence of hydrocarbons in some certain reservoirs during cretaceous age and other reservoirs in the same fields don't have any hydrocarbon accumulation. Detailed seismic data interpretation was performed for the target units of BED 3 and Sitra 8 oilfields in time domain and converted to depth domain. Sitra 8 Field is a three-way dip closure bounded by NW-SE faults while BED 3 field is represented by a WNW-ESE trending horst dipping to the east. The Albian-Cenomanian Kharita Formation has a high energy shallow marine shelf environment and considered as the main pay zone in the BED 3 oilfield. On the other hand, Kharita sands are dry in the Sitra 8 Field. Also, the shallow marine shale, sandstone, limestone and dolomite interbeds of the Abu Roash G Member are another hydrocarbon bearing reservoir in the Sitra 8 Field. Sealing mechanisms were applied to explain why certain reservoirs have hydrocarbon and others don't. Allan's juxtaposition diagram for the main faults in the study area shows that Kharita sands in BED 3 area have excellent juxtaposition as Kharita juxtapose to upper Bahariya and intra Bahariya, which consist of shale and limestone. Abu Roash G sands in BED 3 area have bad juxtaposition as the Abu Roash G juxtapose to Abu Roash C sand (sand juxtaposed sand). Allan's diagram shows that the Abu Roash G reservoir (main target) in Sitra 8 is juxtaposing Abu Roash D which is composed of limestone and shale

  8. Field Observation and Numerical Modeling of Bed-Material Transport Dynamics in the Lower Mississippi River

    Science.gov (United States)

    Ramirez, M. T.; Allison, M. A.; Meselhe, E. A.

    2012-12-01

    Understanding specific pathways for sand transport through the lower reaches of large rivers like the Mississippi is a key to addressing (1) significant source-to-sink geologic problems for sediment and particulate organic carbon and (2) environmental restoration efforts in deltas under threat from climate change. Five field studies were performed in the Mississippi River 75-100 km upstream of the Gulf of Mexico outlet in 2010 and 2011 at discharges ranging from 18,500 to 32,000 m3 s-1 to examine sand transport phenomena in the river channel. These studies utilized multibeam sonar bathymetric surveys, acoustic Doppler current profiler measurements of current velocity and acoustic backscatter, point-integrated isokinetic suspended sediment sampling, and channel-bed grab sampling to examine fluid flow and suspended/bedload sediment transport. Substantial interaction was observed between flow conditions in the river (boundary shear stress, turbulence intensity), channel-bed morphology (size and extent of sandy bedforms), and bed-material sand transport (quantity, transport mode, and spatial distribution). A lateral shift was observed in the region of maximum dune size and water column turbulence intensity from deep to shallow areas of lateral sand bars as water discharge increased, and is associated with the expansion of the bar top area experiencing critical shear stress conditions. Bed material was transported both in traction and in suspension at these water discharges, with the highest suspended mass flux rates associated with the part of the channel cross-section where the largest dunes were present, as a result of a relationship between bed shear stress, dune size, and turbulence intensity. We posit that the downriver flux of sand grains alternates between these two modes over relatively short spatial (up to a few km) and temporal scales. These results complicate the task of using cross-sectional flux measurements taken in lower reaches of large river channels

  9. An experimental study of boiling heat transfer and dryout in heated particulate beds

    International Nuclear Information System (INIS)

    Trenberth, R.; Stevens, G.F.

    1980-07-01

    Boiling heat transfer and dryout occurring in a liquid while it permeates through a bed of self-heated particulate material are phenomena of relevance to reactor safety since they control the rate of heat removal from beds of core debris. Considerable attention is being given to the subject throughout the world, and studies include both in-reactor and laboratory experiments. Results are presented from laboratory experiments in which water was the coolant and in which the particulate material was plated iron shot. The bed of plated iron shot was of rectangular cross-section and was heated by passing low voltage alternating current through the particles. The results presented relate mainly to a systematic study of the effects of bed depth and particle size on dryout power density, but the effect of an additive which significantly reduces the surface tension of the coolant was also examined, as theoretical considerations suggest that this is important. The data exhibit a high degree of consistency, and thus will prove to be valuable in validation of theoretical models. (author)

  10. Conglomerate Fabric and Paleocurrent Measurement in the Braided Fluvial System of the Promina Beds in Northern Dalmatia (Croatia)

    OpenAIRE

    Mrinjek, E.

    1993-01-01

    In the alluvial part of the Promina beds of northern Dalmatia (Late Eocene to possible Early Oligocene age) the main, SW-ward paleocurrent pattern was determined from clast orientation measurements within massive and flat-bedded conglomerates. Preferred clast fabric, facies characteristics, and downward transition into shoreline and shallow-marine sandstone and conglomerate suggest a prograding, braid delta system.

  11. 38 CFR 59.40 - Maximum number of nursing home care and domiciliary care beds for veterans by State.

    Science.gov (United States)

    2010-07-01

    ... home care and domiciliary care beds for veterans by State. 59.40 Section 59.40 Pensions, Bonuses, and... ACQUISITION OF STATE HOMES § 59.40 Maximum number of nursing home care and domiciliary care beds for veterans... projection of demand for nursing home and domiciliary care by veterans who at such time are 65 years of age...

  12. CORE ANALYSIS, DESIGN AND OPTIMIZATION OF A DEEP-BURN PEBBLE BED REACTOR

    Energy Technology Data Exchange (ETDEWEB)

    B. Boer; A. M. Ougouag

    2010-05-01

    Achieving a high burnup in the Deep-Burn pebble bed reactor design, while remaining within the limits for fuel temperature, power peaking and temperature reactivity feedback, is challenging. The high content of Pu and Minor Actinides in the Deep-Burn fuel significantly impacts the thermal neutron energy spectrum. This can result in power and temperature peaking in the pebble bed core in locally thermalized regions near the graphite reflectors. Furthermore, the interplay of the Pu resonances of the neutron absorption cross sections at low-lying energies can lead to a positive temperature reactivity coefficient for the graphite moderator at certain operating conditions. To investigate the aforementioned effects a code system using existing codes has been developed for neutronic, thermal-hydraulic and fuel depletion analysis of Deep-Burn pebble bed reactors. A core analysis of a Deep-Burn Pebble Bed Modular Reactor (400 MWth) design has been performed for two Deep-Burn fuel types and possible improvements of the design with regard to power peaking and temperature reactivity feedback are identified.

  13. Packed Bed Bioreactor for the Isolation and Expansion of Placental-Derived Mesenchymal Stromal Cells.

    Science.gov (United States)

    Osiecki, Michael J; Michl, Thomas D; Kul Babur, Betul; Kabiri, Mahboubeh; Atkinson, Kerry; Lott, William B; Griesser, Hans J; Doran, Michael R

    2015-01-01

    Large numbers of Mesenchymal stem/stromal cells (MSCs) are required for clinical relevant doses to treat a number of diseases. To economically manufacture these MSCs, an automated bioreactor system will be required. Herein we describe the development of a scalable closed-system, packed bed bioreactor suitable for large-scale MSCs expansion. The packed bed was formed from fused polystyrene pellets that were air plasma treated to endow them with a surface chemistry similar to traditional tissue culture plastic. The packed bed was encased within a gas permeable shell to decouple the medium nutrient supply and gas exchange. This enabled a significant reduction in medium flow rates, thus reducing shear and even facilitating single pass medium exchange. The system was optimised in a small-scale bioreactor format (160 cm2) with murine-derived green fluorescent protein-expressing MSCs, and then scaled-up to a 2800 cm2 format. We demonstrated that placental derived MSCs could be isolated directly within the bioreactor and subsequently expanded. Our results demonstrate that the closed system large-scale packed bed bioreactor is an effective and scalable tool for large-scale isolation and expansion of MSCs.

  14. Glacier beds that will be exposed in the future: How will geomorphologic and hydrologic processes develop?

    Science.gov (United States)

    Linsbauer, Andreas; Paul, Frank; Haeberli, Wilfried

    2014-05-01

    The rapid shrinkage of glaciers in the Alps has widespread impacts on relief development and hydrology. Slope failures, collapse of lateral moraines, loose debris in glacier fore-fields, new lakes and changing river beds are among the most visible impacts. They already require increased attention by tourists, monitoring by local authorities and mitigation measures (e.g. www.gletschersee.ch). A view into potential future developments (after glaciers have disappeared) is thus of high interest. With recently developed models that reconstruct glacier bed topography from easily available datasets (e.g. glacier outlines and a DEM) over entire mountain ranges, potential developments of the landscape and hydrology can be quantitatively determined. The modelled glacier beds - though they must be seen as a rough first order approximation only - also allows the investigation of a wide range of glaciological relations and dependencies that have been widely applied but were never investigated for a large sample of glaciers so far. A key reason is that information on glacier thickness distribution and total ice volume is sparse and that the future development of glaciers can only be modelled realistically when a glacier bed is available. Hence, with the glacier beds now available there is a larger number of geomorphological, glaciological and hydrological studies ahead of us. This presentation is providing an overview on the lessons learned about glaciers and their future development from the modelled glacier beds, the expected changes in hydrology (e.g. decreasing glacier volume and formation of new lakes) and potential impacts from the altered geomorphology (e.g. debuttressing of rock walls). In particular the flat tongues of larger valley glaciers are rather thick and leave oversteepened lateral moraines or rock walls behind, towering above overdeepenings in the glacier bed that might be filled with water. It is thus expected that the hazard potential will further increase in

  15. Deformation of the rock pillar caused by bed operation using the room and pillar system

    Science.gov (United States)

    Grzebyk, Wiesław; Stolecki, Lech

    2017-11-01

    The copper ore deposit of the Legnica-Głogów Copper Mining District a one-deck bed formed from the contact of weak sandstone rocks, and solid, durable dolomite rocks, separated by a layer of copper slate. The bed operation is carried out using the room and pillar system. The course of deformation in such bed operation systems is determined by the mutual interaction of particular elements of the geo-mechanical system which include: the roof slab, the pillars and the excavation bed. Due to the possibility of human intervention, structural pillars - whose strength properties can be determined by the appropriate selection of their dimensions and shape - play a particular role in this system. The optimization of the properties of these pillars is mainly based on the results of laboratory tests of rock samples in the strength test machine and on the basis of visual observations of their behavior in situ. The article presents the experimental results carried out under pit conditions in order to determine the rock pillar reaction. Suitable observations were made using the so-called volumetric method. The obtained results were discussed in relation to the results of strength tests on rock samples, indicating the limited similarity to the deformation characteristics.

  16. Inter- and Intrafraction Uncertainty in Prostate Bed Image-Guided Radiotherapy

    International Nuclear Information System (INIS)

    Huang, Kitty; Palma, David A.; Scott, Danielle; McGregor, Danielle; Gaede, Stewart; Yartsev, Slav; Bauman, Glenn; Louie, Alexander V.; Rodrigues, George

    2012-01-01

    Purpose: The goals of this study were to measure inter- and intrafraction setup error and prostate bed motion (PBM) in patients undergoing post-prostatectomy image-guided radiotherapy (IGRT) and to propose appropriate population-based three-dimensional clinical target volume to planning target volume (CTV–PTV) margins in both non-IGRT and IGRT scenarios. Methods and Materials: In this prospective study, 14 patients underwent adjuvant or salvage radiotherapy to the prostate bed under image guidance using linac-based kilovoltage cone-beam CT (kV-CBCT). Inter- and intrafraction uncertainty/motion was assessed by offline analysis of three consecutive daily kV-CBCT images of each patient: (1) after initial setup to skin marks, (2) after correction for positional error/immediately before radiation treatment, and (3) immediately after treatment. Results: The magnitude of interfraction PBM was 2.1 mm, and intrafraction PBM was 0.4 mm. The maximum inter- and intrafraction prostate bed motion was primarily in the anterior–posterior direction. Margins of at least 3–5 mm with IGRT and 4–7 mm without IGRT (aligning to skin marks) will ensure 95% of the prescribed dose to the clinical target volume in 90% of patients. Conclusions: PBM is a predominant source of intrafraction error compared with setup error and has implications for appropriate PTV margins. Based on inter- and estimated intrafraction motion of the prostate bed using pre- and post-kV-CBCT images, CBCT IGRT to correct for day-to-day variances can potentially reduce CTV–PTV margins by 1–2 mm. CTV–PTV margins for prostate bed treatment in the IGRT and non-IGRT scenarios are proposed; however, in cases with more uncertainty of target delineation and image guidance accuracy, larger margins are recommended.

  17. Conceptual design of a fluidized bed nuclear reactor : Statics, dynamics and safety-related aspects

    NARCIS (Netherlands)

    Agung, A.

    2007-01-01

    In this thesis a conceptual design of an innovative high temperature reactor based on the fluidization principle (FLUBER) is proposed. The reactor should satisfy the following requirements: (a) modular and low power, (b)) large shutdown margin, (c) able to produce power when the bed of particles

  18. Influence of geometry on pressure and velocity distribution in packed-bed methanol steam reforming reactor

    Science.gov (United States)

    Ivanović, Ivana; Sedmak, Aleksandar; Milošević, Miloš; Cvetković, Ivana; Pohar, Andrej; Likozar, Blaž

    2017-07-01

    The main tasks of this research is to propose several changes in the packed bed micro methanol steam reformer geometry in order to ensure its performance. The reformer is an integral part of the existing indirect internal reforming high temperature PEMFC and most of its geometry is already defined. The space for remodeling is very limited.

  19. Sediment heterogeneity and mobility in the morphodynamic modelling of gravel-bed braided rivers

    NARCIS (Netherlands)

    Singh, Umesh; Crosato, A.; Giri, Sanjay; Hicks, Murray

    2017-01-01

    The effects of sediment heterogeneity and sediment mobility on the morphology of braided rivers are still poorly studied, especially when the partial sediment mobility occurs. Nevertheless, increasing the bed sediment heterogeneity by coarse sediment supply is becoming a common practice in river

  20. Sediment concentration and bed form structures of Gulf of Cambay from remote sensing

    Digital Repository Service at National Institute of Oceanography (India)

    Kunte, P.D.

    The continental shelf on the west coast of India is the widest off Mumbai, Maharashtra, India and leads to a strongly converging channel, the Gulf of Cambay (GoC). Tides in this Gulf are the largest on the Indian coast. The flow-generated bed forms...

  1. Evaluation of Sleeping Comfort of Bed Mattresses using Physiological and Psychological Response Measurements

    Science.gov (United States)

    Aoi, Masataka; Kamijo, Masayoshi; Yoshida, Hiroaki

    The purpose of this study is to create a method of evaluating the quality of sleep based on the elastic properties of bed mattresses through measurement of physiological and psychological responses while sleeping. We gathered Profile of Mood States (POMS) results before and after sleep, and investigated changes in subjects' moods according to sleep. A total of 4 bed mattresses with different degrees of elasticity were prepared. They were all pocket coil mattresses. We conducted polysomnography (PSG) testing on subjects with a bioamplifier while they slept in each bed mattress, so that sleeping depth indicating the quality of sleep could be estimated. PSG is a comprehensive recording of the biophysiological changes that occur during sleep. As a result, the sleep depth of bed mattress with a high degree of elasticity increased in the PSG evaluation. Because the hip sinks in deeply from the waist, it is not easy to turn over on mattresses with a low degree of elasticity. We have therefore considered that the sleep depth of the subjects became shallow as a result. We have concluded that it is possible to estimate the quality of sleep through analysis of PSG and POMS results.

  2. Co-firing coal and biomass in a fluidised bed boiler

    CSIR Research Space (South Africa)

    North, BC

    2005-11-01

    Full Text Available of biomass is “CO2 Neutral”. The CSIR was approached by one of its licensees, International Combustion (Africa) Ltd (ICAL), to design the fluidised bed combustion (FBC) zone for a biomass waste and coal co-fired boiler. This boiler had been requested by a...

  3. Experience gained in bench scale and pilot scale fluidised bed processing

    CSIR Research Space (South Africa)

    Hadley, TD

    2005-01-01

    Full Text Available , considerable progress has been made. The earliest developments were in coal combustion. This was formalised in the formation of the NFBC boiler in the early 1980’s for the investigation of utilising discard and duff coals. Work has been done on in-bed sulphur...

  4. Experience gained in pilot-scale and bench-scale fluidised beds processing

    CSIR Research Space (South Africa)

    Hadley, TD

    2006-02-01

    Full Text Available , considerable progress has been made. The earliest developments were in coal combustion. Work has been done on in-bed sulphur capture to reduce the sulphur dioxide off-gas content. Expertise in the design and commissioning of industrial-scale plants has led...

  5. Staff/bed and staff/patient ratios in South African public sector mental ...

    African Journals Online (AJOL)

    Objectives. To document staff/bed and staff/patient ratios in public. sector mental health services in South Africa. Design. Cross-sectional survey. Method. Aquestionnaire was distributed to provincial mental health co-ordinators requesting numbers of full-time equivalent (FTE) staff who provide mental health care at all ...

  6. Selenate removal in methanogenic and sulfate-reducing upflow anaerobic sludge bed reactors

    NARCIS (Netherlands)

    Lenz, M.; Hullebusch, van E.D.; Hommes, G.; Corvini, P.F.X.; Lens, P.N.L.

    2008-01-01

    This paper evaluates the use of upflow anaerobic sludge bed (UASB) bioreactors (30 degrees C, pH = 7.0) to remove selenium oxyanions from contaminated waters (790 mu g Se L-1) under methanogenic and sulfate-reducing conditions using lactate as electron donor. One UASB reactor received sulfate at

  7. Perceived Threat of Malaria and the Use of Insecticide Treated Bed ...

    African Journals Online (AJOL)

    2013-12-17

    Dec 17, 2013 ... The study mainly used data from 40 semi-structured interviews, 20 in-depth interviews and four Focus ... study employed an 'etic-reflective' approach for the presentation of data collected. This approach of .... traditional bed nets which were readily available in the markets in the big cities. The use of the net ...

  8. Sage-Grouse and Coal-Bed Methane: Can They Coexist within the Powder River Basin?

    Science.gov (United States)

    Duncan, Michael B.

    2010-01-01

    Concerns are growing regarding the availability of sustainable energy sources due to a rapidly growing human population and a better understanding of climate change. In recent years, the United States has focused much attention on developing domestic energy sources, which include coal-bed methane (CBM). There are vast deposits of the natural gas…

  9. Bed net use and associated factors in a rice farming community in Central Kenya

    Directory of Open Access Journals (Sweden)

    Kabuage Lucy

    2009-04-01

    Full Text Available Abstract Background Use of insecticide-treated nets (ITNs continues to offer potential strategy for malaria prevention in endemic areas. However their effectiveness, sustainability and massive scale up remain a factor of socio-economic and cultural variables of the local community which are indispensable during design and implementation stages. Methods An ethnographic household survey was conducted in four study villages which were purposefully selected to represent socio-economic and geographical diversity. In total, 400 households were randomly selected from the four study villages. Quantitative and qualitative information of the respondents were collected by use of semi-structured questionnaires and focus group discussions. Results Malaria was reported the most frequently occurring disease in the area (93% and its aetiology was attributed to other non-biomedical causes like stagnant water (16%, and long rains (13%. Factors which significantly caused variation in bed net use were occupant relationship to household head (χ2 = 105.705; df 14; P = 0.000, Age (χ2 = 74.483; df 14; P = 0.000, village (χ2 = 150.325; df 6; P = 0.000, occupation (χ2 = 7.955; df 3; P = 0.047, gender (χ2 = 4.254; df 1; P = 0.039 and education levels of the household head or spouse (χ2 = 33.622; df 6; P = 0.000. The same variables determined access and conditions of bed nets at household level. Protection against mosquito bite (95% was the main reason cited for using bed nets in most households while protection against malaria came second (54%. Colour, shape and affordability were some of the key potential factors which determined choice, use and acceptance of bed nets in the study area. Conclusion The study highlights potential social and economic variables important for effective and sustainable implementation of bed nets-related programmes in Sub-Saharan Africa.

  10. Comparison of PIV measurements and a discrete particle model in a rectangular 3D spout-fluid bed

    NARCIS (Netherlands)

    Link, J.M.; Deen, N.G.; Kuipers, J.A.M.

    2004-01-01

    Particle image velocimetry and a 3D hard sphere discrete particle model were applied to determine particle velocity profiles in the plane around a spout in a spoutfluid bed for various initial bed heights, spout and background fluidization velocities. Comparison between experimental and numerical

  11. Numerical and experimental studies on thermal deformation of ceramic breeder pebble bed systems

    Science.gov (United States)

    An, Zhiyong

    The goal of this work is to develop modeling capabilities for understanding and predicting thermo-mechanical behavior of ceramic breeder pebble bed systems at elevated temperatures (600-800°C). The thermo-mechanical behavior of solid breeder pebble beds is a critical issue for the solid breeder blanket designs and is different from the behaviors of solid materials. The issue includes potential breakage of pebble materials and change in heat transfer characteristics across the breeder materials and cladding interface. Furthermore, at elevated temperatures, thermal creep deformation plays an uncertain role related to the contact stresses in the pebble beds. To understand these effects, the following efforts have been undertaken: First, experiments of a typical breeder blanket design have been conducted to study the thermal creep behaviors of the pebble bed system. Other than providing data for benchmarking numerical simulation, the experimental results show that the thermal deformation behaviors of typical pebble materials, such as Li2O and Li4SiO4 lithium ceramics, are nonlinear with respect to time and temperature. Under fixed temperatures (higher than 600°C), stresses generated from differential thermal expansion begin to decrease as a result of creep deformation. Second, a new numerical program, based on discrete element method (DEM), has been developed to simulate the fundamental mechanical behaviors of the packed pebble bed system. Considering the effects in a high temperature situation, inelastic contact models have been derived to predict thermal creep deformation. Our DEM program is mainly used to derive the effective mechanical constitutive equations for a pebble bed system. Besides that, it can provide the stress distribution inside the pebble bed and the force evolution related to the changes of boundary loadings. Last, a numerical program based on the finite element analysis (FEA) has been utilized to simulate the stress magnitude and deformation

  12. Wet granulation in rotary processor and fluid bed: Comparison of granule and tablet properties

    OpenAIRE

    Kristensen, Jakob; Hansen, Vibeke Wallaert

    2006-01-01

    The aim of the present study was to investigate and compare granule and tablet properties of granules prepared by wet granulation in a rotary processor or a conventional fluid bed. For this purpose the working range of selected process variables was determined and a factorial study with 3 factors (equipment type, filler type, and liquid addition rate) and 1 covariate (fluidizing air flow rate) was performed. Two grades of calcium carbonate with different size and shape characteristics were ap...

  13. Hydrodynamics of concordant and discordant fixed bed open-channel confluences

    Science.gov (United States)

    Birjukova Canelas, Olga; Lage Ferreira, Rui Miguel; Heleno Cardoso, António

    2017-04-01

    The detailed characterization of the flow field in river confluences constitutes a relevant step towards the understanding of the hydro-morpho-dynamics of these key zones of the fluvial system. With a few exceptions, existing works on this topic covered concordant bed scenarios, meaning that both confluent channels had the same elevation. This laboratory study aims to contribute to a detailed three-dimensional characterization of the flow field at a fixed bed confluence, as well as to shed light on how bed elevation discordance modifies the flow patterns of the converging flows. While the junction angle and the discharge ratio were kept fixed, two scenarios were studied on the basis of detailed water level and 3D ADV measurements at the denser mesh ever. The internal flow structure of the concordant bed scenario mostly complied with the classical conceptual models. A relevant difference concerns the size of the stagnation zone, much smaller close to the bed of the discordant bed confluence. A more significant difference is a horizontal flow structure, not previously identified in the literature, characterized by strong streamwise mean vorticity and strong secondary motion. It is observed for the discordant bed case, occurring along the inner wall of the main channel and downstream the junction corner. This structure is spatially well-correlated to a pronounced imbalance of cross-stream and vertical normal Reynolds stresses. This highlights the role of Reynolds stress anisotropy (RSA) that is generated in the shear layers than accompany the entrance of the tributary flow. Since this structure is not present in the concordant case, where RSA is also evident, it is argued that convective effects should also play a role in its formation, presumably due to deflection of the flow in the main channel by the tributary. The newly identified secondary motion should, thus, be a combination of Prandtĺs second kind and Prandtĺs first kind of secondary flow. The relative

  14. Healthy Life-Years Lost and Excess Bed-Days Due to 6 Patient Safety Incidents

    Science.gov (United States)

    Wang, Shaolin; Vincent, Charles; Smith, Peter C.

    2017-01-01

    Background: There is little satisfactory evidence on the harm of safety incidents to patients, in terms of lost potential health and life-years. Objective: To estimate the healthy life-years (HLYs) lost due to 6 incidents in English hospitals between the years 2005/2006 and 2009/2010, to compare burden across incidents, and estimate excess bed-days. Research Design: The study used cross-sectional analysis of the medical records of all inpatients treated in 273 English hospitals. Patients with 6 types of preventable incidents were identified. Total attributable loss of HLYs was estimated through propensity score matching by considering the hypothetical remaining length and quality of life had the incident not occurred. Results: The 6 incidents resulted in an annual loss of 68 HLYs and 934 excess bed-days per 100,000 population. Preventable pressure ulcers caused the loss of 26 HLYs and 555 excess bed-days annually. Deaths in low-mortality procedures resulted in 25 lost life-years and 42 bed-days. Deep-vein thrombosis/pulmonary embolisms cost 12 HLYs, and 240 bed-days. Postoperative sepsis, hip fractures, and central-line infections cost incidents is roughly comparable with the UK burden of Multiple Sclerosis (80 DALYs per 100,000), HIV/AIDS and Tuberculosis (63 DALYs), and Cervical Cancer (58 DALYs). There were marked differences in the harm caused by the incidents, despite the public attention all of them receive. Decision makers can use the results to prioritize resources into further research and effective interventions. PMID:27753744

  15. Pressure drop in packed beds of spherical particles at ambient and elevated air temperatures

    Directory of Open Access Journals (Sweden)

    Pešić Radojica

    2015-01-01

    Full Text Available The aim of this work was the experimental investigation of the particle friction factor for air flow through packed bed of particles at ambient and elevated temperatures. The experiments were performed by measuring the pressure drop across the packed bed, heated to the desired temperature by hot air. Glass spherical particles of seven different diameters were used. The temperature range of the air flowing through the packed bed was from 20ºC to 350ºC and the bed voidages were from 0.3574 to 0.4303. The obtained results were correlated using a number of available literature correlations. The overall best fit of all of the experimental data was obtained using Ergun [1] equation, with mean absolute deviation of 10.90%. Ergun`s equation gave somewhat better results in correlating the data at ambient temperature with mean absolute deviation of 9.77%, while correlation of the data at elevated temperatures gave mean absolute deviation of 12.38%. The vast majority of the correlations used gave better results when applied to ambient temperature data than to the data at elevated temperatures. Based on the results obtained, Ergun [1] equation is proposed for friction factor calculation both at ambient and at elevated temperatures. [Projekat Ministarstva nauke Republike Srbije, br. ON172022

  16. Body posture recognition and turning recording system for the care of bed bound patients.

    Science.gov (United States)

    Hsiao, Rong-Shue; Mi, Zhenqiang; Yang, Bo-Ru; Kau, Lih-Jen; Bitew, Mekuanint Agegnehu; Li, Tzu-Yu

    2015-01-01

    This paper proposes body posture recognition and turning recording system for assisting the care of bed bound patients in nursing homes. The system continuously detects the patient's body posture and records the length of time for each body posture. If the patient remains in the same body posture long enough to develop pressure ulcers, the system notifies caregivers to change the patient's body posture. The objective of recording is to provide the log of body turning for querying of patients' family members. In order to accurately detect patient's body posture, we developed a novel pressure sensing pad which contains force sensing resistor sensors. Based on the proposed pressure sensing pad, we developed a bed posture recognition module which includes a bed posture recognition algorithm. The algorithm is based on fuzzy theory. The body posture recognition algorithm can detect the patient's bed posture whether it is right lateral decubitus, left lateral decubitus, or supine. The detected information of patient's body posture can be then transmitted to the server of healthcare center by the communication module to perform the functions of recording and notification. Experimental results showed that the average posture recognition accuracy for our proposed module is 92%.

  17. The study of partitioning of heavy metals during fluidized bed combustion of sewage sludge and coal

    Energy Technology Data Exchange (ETDEWEB)

    Gulyurtlu, Ibrahim; Lopes, M. Helena; Abelha, Pedro; Cabrita, Isabel; Oliveira, J.F. Santos

    2003-07-01

    The behaviour of Cd, Cr, Cu, Co, Mn, Pb, Zn and Hg during the combustion tests of granular dry sewage sludges on a pilot FBC of about 0,3 MW was evaluated. The emissions of these heavy metals from mono-combustion were compared with those of co-combustion of the sludge with a bituminous coal. The effect of the addition of limestone was also studied in order to retain sulphur compounds and to verify its influence on the retention of heavy metals. Heavy metals were collected and analysed from different locations of the installation, which included the stack, the two cyclones and the material removed from the bed. The results showed that the volatility of metals was rather low, resulting in emissions below the legal limits of the new directive on incineration, with the exception of Hg during the mono-combustion tests. The partitioning of metals, except for Hg, appeared to follow that of ashes, amounting to levels above 90% in the bed streams in the mono-combustion case. For co-combustion, there was a lower fixation of HM in the bed ashes, mostly originating essentially from the sewage sludge, ranging between 40 and 80%. It is believed that in this latter case, a slightly higher bed temperature could have enhanced the volatilisation, especially of Cd and Pb. However these metals were then retained in cyclone ashes. In the case of Hg, the volatilisation was complete. The bed ashes were free of Hg and part of it was retained in the cyclone and emitted as both fine ash particles and in gaseous forms. In mono-combustion the Hg emissions from the stack (particles and gas) accounted for about 50%, although there was a significant amount unaccounted for. This appeared to have significantly decreased in the case of co-combustion, as only about 15% has been emitted, due to the retention effect of cyclone ashes which presented high quantities of unburned carton and possibly condensed sulphur species.

  18. Relation between shell beds and trace fossils of the Albian-Cenomanian Aitamir Formation in Amirabad anticline- northeast Mashhad

    Directory of Open Access Journals (Sweden)

    H., Mohamadian,

    2012-01-01

    Full Text Available Aitamir Formation (Albian-Cenomanian in the Kopet-Dagh Basin has diverse trace fossils and several shell beds. These trace fossils contain diverse ethological patterns, including domichnia, fodinichnia, grazing, equilibrichnia, navichnia, chemichnia and fugichnia. The types of shell beds distinguished based on differences in sedimentological, palaeoecological and taphonomic features. Shell beds and sandstone layers containing characteristic trace fossils represent a storm-influenced succession. Bioturbation increases markedly towards the top of the shell beds as the energy of deposition declines to allow colonization by benthonic faunal assemblages. Types of shell beds generally including (1 initial firmground substrates in foreshore to offshore environments as indicated by the Glossifungites ichnofacies, including Gastrochaenolites, Rhizocorallium and Thalassinoides, (2 basal storm-erosive lag deposits, (3 re-worked shell beds of main storm deposits as indicated by the Glossifungites ichnofacies, including Ophiomorpha (4 fair-weather shell beds in a near-shore position and above fair-weather wave base. (5 Composite or multiple-event concentration from time averaged and multiple event deposit. Seven trace fossil assemblages are identified in Aitamir Formation deposits. They are (1 the Zoophycos Ichnofacies (2 the distal Cruziana ichnofacies, (3 the archetypical Cruziana ichnofacies, (4 the mixed Skolithos-Cruziana ichnofacies, (5 the distal Skolithos ichnofacies, (6 the archetypal Skolithos Ichnofacies, and (7 impoverished expression of the Skolithos ichnofacies. This succession of shell beds and trace fossil assemblages reflects a gradational decrease in hydraulic energy levels induced by storms.

  19. Examining time trends in the Oldowan technology at Beds I and II, Olduvai Gorge.

    Science.gov (United States)

    Kimura, Yuki

    2002-09-01

    The lithic analysis of the Bed I and II assemblages from Olduvai Gorge reveals both static and dynamic time trends in early hominids' technology from 1.8 to 1.2 m.y.a. The Bed I Oldowan (1.87-1.75 m.y.a.) is characterized by the least effort strategy in terms of raw material exploitation and tool production. The inclusion of new raw material, chert, for toolmaking in the following Developed Oldowan A (DOA, 1.65-1.53 m.y.a.) facilitated more distinctive and variable flaking strategies depending on the kind of raw materials. The unique characters of DOA are explainable by this raw material factor, rather than technological development of hominids. The disappearance of chert in the subsequent Developed Oldowan B and Acheulian (1.53-1.2 m.y.a.) necessitated a shift in tool production strategy more similar to that of Bed I Oldowan than DOA. However, the evidence suggests that Bed II hominids might have been more skillful toolmakers, intensive tool-users, and engaged in more active transport of stone tools than the Bed I predecessors. Koobi Fora hominids maintained a more static tool-using behavior than their Olduvai counterparts due mainly to a stable supply of raw materials. They differed from Olduvai hominids in terms of less battering of cores, consistent transport behavior, and few productions of side-struck flakes, indicating a regional variation of toolmaking and using practice. However, they shared with Olduvai hominids a temporal trend toward the production of larger flakes from larger cores after 1.6 m.y.a. Increased intake of animal resources and the expansion of ranging area of Homo ergaster would have led to the development of technological organization. Technological changes in the Oldowan industry are attested at Olduvai Gorge, Koobi Fora, and Sterkfontein, suggesting that it was a pan-African synchronous phenomenon, beginning at 1.5 m.y.a.

  20. Scour around a submerged cylinder and marine hydrokinetic (MHK) device in live-bed conditions

    Science.gov (United States)

    Beninati, Maria Laura; Volpe, Michael; Krane, Michael; Fontaine, Arnold

    2013-11-01

    Experiments are presented to explore how sediment scour around a single Marine Hydrokinetic (MHK) turbine varies with flow speed. Three Reynolds numbers, based on support structure diameter were used to induce live-bed scour conditions. Based on results from previous studies on submerged cylinders, differences in scour patterns between a single cylinder and MHK device can be determined. In the case of MHK energy, many devices are submerged in the flow. Thus, it is important to analyze the impact of both the support structure and the addition of the rotating blades. The experiments were performed in the small-scale testing platform in the hydraulic flume facility at Bucknell University. For each test case, bed form topology was measured after a three-hour time interval using a traversing two-dimensional bed profiler. During the experiment, scour depth measurements at the front face of the cylindrical support structure were taken to estimate the scour rate. Measurements of the bed form were taken across the width of the test section. Results show that the scour hole dimensions increase in the presence of the MHK device. These dimensions also increase with increasing Reynolds number.

  1. Uptake of Cd(II Using Natural Zeolite: Batch and Continuous Fixed-Bed Studies

    Directory of Open Access Journals (Sweden)

    Luna M. LMarashdeh

    2009-12-01

    Full Text Available Uptake of Cd(II ions by natural phillipsite tuff was investigated both in shake-flask and fixed-bed columns. Equilibrium uptake, qe, was found to best fit Langmuir adsorption isotherm with a maximum value of 25.78 mg/g. Percent removal of Cd ions was close to 100% from initial metal ion concentrations in the range 50 - 75 mg/L at 5.0 g zeolite/L. Also, qe was found to vary exponentially with zeolite dose. Break points as high as 350 minutes were obtained from bed treatment at favorable conditions of a low solution flow rate and high bed depth. In batch experiments, equilibrium pH increased to < 8.0 excluding chemical precipitation as part of the removal while in fixed-beds the final pH exceeded 9.0. It is suggested that a sieve action of zeolite porous structure plays a role as an uptake mechanism in addition to the ion exchange.

  2. Coolability of a 3D homogeneous debris bed, experimental and numerical investigations

    International Nuclear Information System (INIS)

    Atkhen, K.; Berthoud, G.

    2001-01-01

    Within the framework of nuclear safety analysis, we present here experimental and numerical results in the field of debris bed coolability. Experimental data are provided by the SILFIDE 3D experimental facility in which the debris bed is heated by induction, at Electricite de France (EDF). Numerical computations are obtained with MC3D-REPO which is a 3-phase and 3D code developed by the Commissariat a l'Energie Atomique (CEA). The uniform debris bed consists of 2 and 3,17 mm diameter steel beads contained in a 50 cm x 60 cm x 10 cm vessel. Water is used as a coolant and can be introduced either by the top or the bottom of the bed at a determined temperature. Due to heterogeneous power distribution within the bed, two definitions for the critical heat flux are proposed: the classical mean value and the local flux (much higher). Even in the first case, the measured dryout heat flux is higher than the Lipinsky 1-D flux. Temperature curve analyses show that the dryout phenomenon is very local, therefore one should be careful about the right flux definition to use. As the injected power is being increased stepwise, steady temperature stages above saturation temperature before dryout can be observed. A discussion is proposed. For some very high values of the induction power, some spheres melted together, leading to a bigger non-porous region. Even if the local temperature went over 1300 C, the bed was still coolable and the critical heat flux value was not impacted. Some parametric studies led to the following conclusions: bottom coolant injection leads to a twice time higher critical flux than by top injection, the influence of the height of the water pool above debris bed is negligible, a sub-cooled liquid injection has no influence on the coolability. Fluidization of surface particles is also discussed. The MC3D-REPO model assumes a thermal equilibrium between the three phases, which gives results in agreement with experiments until dryout occurs. (author)

  3. Model Test Bed for Evaluating Wave Models and Best Practices for Resource Assessment and Characterization

    Energy Technology Data Exchange (ETDEWEB)

    Neary, Vincent Sinclair [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Water Power Technologies; Yang, Zhaoqing [Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Coastal Sciences Division; Wang, Taiping [Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Coastal Sciences Division; Gunawan, Budi [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Water Power Technologies; Dallman, Ann Renee [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Water Power Technologies

    2016-03-01

    A wave model test bed is established to benchmark, test and evaluate spectral wave models and modeling methodologies (i.e., best practices) for predicting the wave energy resource parameters recommended by the International Electrotechnical Commission, IEC TS 62600-101Ed. 1.0 ©2015. Among other benefits, the model test bed can be used to investigate the suitability of different models, specifically what source terms should be included in spectral wave models under different wave climate conditions and for different classes of resource assessment. The overarching goal is to use these investigations to provide industry guidance for model selection and modeling best practices depending on the wave site conditions and desired class of resource assessment. Modeling best practices are reviewed, and limitations and knowledge gaps in predicting wave energy resource parameters are identified.

  4. Toxicity of selected essential oils, silicone oils, and paraffino oil against the common bed bug, cimex lectularius L. (Hemiptera: Cimicidae)

    Science.gov (United States)

    The common bed bug (Cimex lectularius L.) resurged in the U.S. and many other countries over the past decade. The need for safe and effective bed bug control products propelled the development of numerous “green pesticides”, mostly with essential oils listed as active ingredients. Various inorganic ...

  5. Exploring Innovative Solutions for Quality of Life and Care of Bed-Ridden Nursing Home Residents through Codesign Sessions

    NARCIS (Netherlands)

    C.J.M.L. van Dijck-Heinen; M. Nieboer; L Zwerts-Verhelst; H.A. van der Vrande; Eveline Wouters; C. Vissers-Luijcks; A.M.C. Dooremalen; R.A. Overdiep; M. Wetzels; M.J.G.A. Moonen; P.J.L.M. Eyck; Joost van Hoof; Dr. Sil Aarts; C. van der Voort; A.M.E. van Gorkom

    2015-01-01

    Bed-ridden nursing home residents are in need of environments which are homelike and facilitate the provision of care. Design guidance for this group of older people is limited. This study concerned the exploration and generation of innovative environmental enrichment scenarios for bed-ridden

  6. Performance of bed-load transport equations relative to geomorphic significance: Predicting effective discharge and its transport rate

    Science.gov (United States)

    Jeffrey J. Barry; John M. Buffington; Peter Goodwin; John .G. King; William W. Emmett

    2008-01-01

    Previous studies assessing the accuracy of bed-load transport equations have considered equation performance statistically based on paired observations of measured and predicted bed-load transport rates. However, transport measurements were typically taken during low flows, biasing the assessment of equation performance toward low discharges, and because equation...

  7. The study of partitioning of heavy metals during fluidized bed combustion of sewage sludge and coal

    Energy Technology Data Exchange (ETDEWEB)

    Gulyurtlu, I.; Lopes, M.H.; Abelha, P.; Cabrita, I.; Oliveira, J.F.S. [INETI, Lisbon (Portugal)

    2006-06-15

    The behavior of Cd, Cr, Cu, Co, Mn, Ni, Pb, Zn, and Hg during the combustion tests of a dry granular sewage sludge on a fluidized bed combustor pilot (FBC) of about 0.3 MW was evaluated. The emissions of these heavy metals from mono-combustion were compared with those of co-combustion of the sludge with a bituminous coal. The effect of the addition of limestone was also studied in order to retain sulphur compounds and to verify its influence on the retention of heavy metals (HM). Heavy metals were collected and analyzed from different locations of the installation, which included the stack, the two cyclones, and the material removed from the bed. The results showed that the volatility of metals was rather low, resulting in emissions below the legal limits of the new directive on incineration, with the exception of Hg during the mono-combustion tests. The partitioning of metals, except for Hg, appeared to follow that of ashes, amounting to levels above 90% in the bed streams in the mono-combustion case. For co-combustion, there was a lower fixation of HM in the bed ashes, mostly originating essentially from the sewage sludge, ranging between 40% and 80%. It is believed that in this latter case, a slightly higher temperature could have enhanced the volatilization, especially of Cd and Pb. However these metals were then retained in fly ashes captured in the cyclones. In the case of Hg, the volatilisation was complete. The bed ashes were free of Hg and part of Hg was retained in the cyclones and the rest was emitted either with fine ash particles or in gaseous forms. In mono-combustion the Hg emissions from the stack (particles and gas) accounted, for about 50%. This appeared to have significantly decreased in the case of co-combustion, as only about 75% has been emitted, due to the retention effect of cyclone ashes.

  8. Palaeogeography of Late Triassic red-beds in Singapore and the Indosinian Orogeny

    Science.gov (United States)

    Oliver, Grahame; Prave, Anthony

    2013-10-01

    A red-bed facies of the Upper Triassic Jurong Formation has been logged on Sentosa Island, Singapore. An overall coarsening and thickening-upward pattern is well developed. The lower part of the section is dominated by purple-red, massive to finely laminated illite-smectite-kaolin-rich mudstones containing thin, discontinuous lenses of fine sandstone marked by low-angle lamination and small ripples. One dinosaur-like foot print has been discovered in a loose block of red mudstone. It is concluded that this is a lacustrine sequence and it is proposed to name the lake, Lake Sentosa. The upper part of the sequence consists of flat-laminated to trough cross-bedded medium-grained sandstone and granule to cobble conglomerates alternating with purple-red mudstone. The mudstone-sandstone packages are arranged in decametre-scale coarsening-upward cycles. The channelling and decimetre-scale cross-bedding characterising the sandstone and conglomeratic beds is evidence for deposition by flashy fluvial flood processes, possibly feeding into the lake as a fresh water delta. One possible dinosaur trackway in granule size conglomerate has been located. Detrital zircon U-Pb ages vary from 2.7 Ba to 209 Ma with significant populations at ˜245 Ma and 220 Ma. These ages throw light on the timing of the Indosinian Orogeny. The molasse red-beds of the Jurong Formation were deposited in a half graben formed in the hangingwall of the Bukit Timah Fault when central Peninsular Malaysia went into extension following the climax of the Indosinian Orogeny in the Late Triassic.

  9. Implementation of true continuous bed motion in 2-D and 3-D whole-body PET scanning

    Science.gov (United States)

    Dahlbom, M.; Reed, J.; Young, J.

    2001-08-01

    True continuous axial bed motion has been implemented on a high-resolution positron emission tomography (PET) scanner for use in both two-dimensional (2-D) and three-dimensional (3-D) acquisition modes. This has been accomplished by modifications in the bed motion controller firmware and by acquiring data in list mode. The new bed controller firmware was shown to provide an accurate and constant bed speed down to 0.25 mm/s with a moderate patient weight load. The constant bed motion eliminates previously reported dead-time due to bed positioning when using small discrete bed steps. The continuous bed motion was tested on uniform phantoms, in 2-D and 3-D. As a result of the continuous axial motion, a uniform axial sensitivity is achieved. This was also reflected in the reconstructed images, which showed an improvement in axial image uniformity (1.4% for continuous sampling, 5.0% for discrete) as well as an improvement in %SD uniformity in comparison to conventional step-and-shoot acquisitions. The use of the continuous axial motion also provide slight improvements in 2-D emission and transmission scanning, resulting in an overall improved image quality in whole-body PET.

  10. Effects of starvation and molting on the metabolic rate of the bed bug (Cimex lectularius L.).

    Science.gov (United States)

    DeVries, Zachary C; Kells, Stephen A; Appel, Arthur G

    2015-01-01

    The bed bug (Cimex lectularius L.) is a common hematophagous pest in the urban environment and is capable of surviving extended periods of starvation. However, the relationship between starvation and metabolism in bed bugs is not well understood. To better understand this relationship, we measured the metabolism of all life stages for >900 h after feeding (starvation) using closed-system respirometry. Measurements were made around molting for the immature life stages, which occurs only after a blood meal. In addition, both mated and unmated adults were measured. Starvation and molting had significant effects on the metabolism of the bed bug. Mass-specific metabolic rate (V(O2); mL g(-1) h(-1)) declined in a curvilinear fashion with the period of starvation for adults and with the postmolting period for immature bed bugs (used to standardize all immature life stages). A standard curve was developed to depict the generalized pattern of metabolic decline observed in all life stages that molted. Individual metabolic comparisons among life stages that molted revealed some differences in metabolic rate between unmated males and females. In addition, the mass scaling coefficient was found to decline with starvation time (postmolting time) for all life stages that molted. In most life stages, the ratio of V(CO2) to V(O2) (respiratory exchange ratio) declined over time, indicating a change in metabolic substrate with starvation. Finally, daily percent loss in body mass declined in a pattern similar to that of V(O2). The observed patterns in metabolic decline are evaluated in relation to the life history of bed bugs. In addition, the evolutionary development of these patterns is discussed. The metabolic pattern after feeding was also found to share several similarities with that of other ectothermic species.

  11. Long-term and high resolution measurements of bed level changes in a temperate, microtidal coastal lagoon

    DEFF Research Database (Denmark)

    Andersen, Thorbjørn J.; Pejrup, Morten; Nielsen, Allan Aasbjerg

    2006-01-01

    This study presents the results of a long-term monitoring program of bed level changes measured during 8 yr at an intertidal mudflat in a microtidal, temperate coastal lagoon. Additionally, bed level measurements obtained at a 10-min temporal resolution at the same tidal flat and at the bed...... of a nearby tidal channel are presented. Short-term changes in bed level are one or two orders of magnitude larger than the annual net-deposition rate, which shows that the environment is highly dynamic with respect to erosion, transport and deposition of fine-grained sediment. Some seasonality in the bed...... level changes was observed and there is a tendency for mudflat deposition in spring, summer and early autumn and erosion during the rest of the year, but interannual variations are large and different parts of the mudflat show different seasonal signals. A close coupling between sub- and intertidal...

  12. Experimental, kinetic and numerical modeling of hydrogen production by catalytic reforming of crude ethanol over a commercial catalyst in packed bed tubular reactor and packed bed membrane reactor

    International Nuclear Information System (INIS)

    Aboudheir, Ahmed; Akande, Abayomi; Idem, Raphael

    2006-01-01

    The demand for hydrogen energy has increased tremendously in recent years essentially because of the increase in the word energy consumption as well as recent developments in fuel cell technologies. The energy information administration has projected that world energy consumption will increase by 59% over the next two decades, from 1999 to 2020, in which the largest share is still dominated by fossil fuels (oil, natural gas and coal). Carbon dioxide (CO 2 ) emissions resulting from the combustion of these fossil fuels currently are estimated to account for three-fourth of human-caused CO 2 emissions worldwide. Greenhouse gas emission, including CO 2 , should be limited, as recommended at the Kyoto Conference, Japan, in December 1997. In this regard, hydrogen (H 2 ) has a significant future potential as an alternative fuel that can solve the problems of CO 2 emissions as well as the emissions of other air contaminants. One of the techniques to produce hydrogen is by reforming of hydrocarbons or biomass. Crude ethanol (a form of biomass, which essentially is fermentation broth) is easy to produce, is free of sulphur, has low toxicity, and is also safe to handle, transport and store. In addition, crude ethanol consists of oxygenated hydrocarbons, such as ethanol, lactic acid, glycerol, and maltose. These oxygenated hydrocarbons can be reformed completely to H 2 and CO 2 , the latter of which could be separated from H 2 by membrane technology. This provides for CO 2 capture for eventual storage or destruction. In the case of using crude ethanol, this will result in negative CO 2 , emissions. In this paper, we conducted experimental work on production of hydrogen by the catalytic reforming of crude ethanol over a commercial promoted Ni-based catalyst in a packed bed tubular reactor as well as a packed bed membrane reactor. As well, a rigorous numerical model was developed to simulate this process in both the catalytic packed bed tubular reactor and packed bed membrane

  13. Patchy bed disturbance and fish predation independently influence the distribution of stream invertebrates and algae.

    Science.gov (United States)

    Effenberger, Michael; Diehl, Sebastian; Gerth, Maximilian; Matthaei, Christoph D

    2011-05-01

    1. The identification of factors determining the patchy distribution of organisms in space and time is a central concern of ecology. Predation and abiotic disturbance are both well-known drivers of this patchiness, but their interplay is still poorly understood, especially for communities dominated by mobile organisms in frequently disturbed ecosystems. 2. We investigated the separate and interactive influences of bed disturbance by floods and predation by fish on the benthic community in a flood-prone stream. Electric fields excluded fish predators from half of 48 stream bed patches (area 0·49 m(2) ) with contrasting disturbance treatments. Three types of bed disturbance were created by either scouring or filling patches to a depth of 15-20 cm or by leaving the patches undisturbed, thus mimicking the mosaic of scour and fill caused by a moderate flood. Benthic invertebrates and algae were sampled repeatedly until 57 days after the disturbance. 3. Disturbance influenced all ten investigated biological response variables, whereas predation affected four variables. Averaged across time, invertebrate taxon richness and total abundance were highest in stable patches. Algal biomass and densities of five of the seven most common invertebrate taxa (most of which were highly mobile) were higher in fill than in scour patches, whereas two taxa were more abundant in scour and stable than in fill patches. Furthermore, two common invertebrate grazers were more abundant and algal biomass tended to be reduced in fish exclusion patches, suggesting a patch-scale trophic cascade from fish to algae. 4. Our results highlight the importance of patchy physical disturbance for the microdistribution of mobile stream organisms and indicate a notable, but less prevalent, influence of fish predation at the patch scale in this frequently disturbed environment. Disturbance and predation treatments interacted only once, suggesting that the observed predation effects were largely independent of

  14. Comparison of fibre optical measurements and discrete element simulations for the study of granulation in a spout fluidized bed

    NARCIS (Netherlands)

    Link, J.M.; Godlieb, W.; Tripp, P.; Deen, N.G.; Heinrich, S.; Kuipers, J.A.M.; Schönherr, M.; Peglow, M.

    2009-01-01

    Spout fluidized beds are frequently used for the production of granules or particles through granulation. The products find application in a large variety of applications, for example detergents, fertilizers, pharmaceuticals and food. Spout fluidized beds have a number of advantageous properties,

  15. Comparison of fibre optical measurements and discrete element simulations for the study of granulation in a spout fluidized bed

    NARCIS (Netherlands)

    Link, J.M.; Godlieb, W.; Tripp, P.; Deen, N.G.; Heinrich, S.; Peglow, M.; Kumar, J.; Kuipers, J.A.M.; Schönherr, M.; Mörl, L.

    2007-01-01

    Spout fluidized beds are frequently used for the production of granules or particles through granulation. The products find application in a large variety of applications, for example detergents, fertilizers, pharmaceuticals and food. Spout fluidized beds have a number of advantageous properties,

  16. Comparison of Fibre Optical Measurements and Discrete Element Simulations for the Study of Granulation in a Spout Fluidized Bed

    NARCIS (Netherlands)

    Link, J.M.; Godlieb, W.; Tripp, P.; Deen, N.G.; Heinrich, S.; Kuipers, J.A.M.; Schönherr, M.; Peglow, M.

    2007-01-01

    Spout fluidized beds are frequently used for the production of granules or particles through granulation. The products find application in a large variety of applications, for example detergents, fertilizers, pharmaceuticals and food. Spout fluidized beds have a number of advantageous properties,

  17. Modelling glacier-bed overdeepenings and possible future lakes for the glaciers in the Himalaya-Karakoram region

    DEFF Research Database (Denmark)

    Linsbauer, A.; Frey, H.; Haeberli, W.

    2016-01-01

    retreat may fill with water and form new lakes. In this study, the bed overdeepenings for ∼28000 glaciers (40 775km2) of the Himalaya-Karakoram region are modelled using GlabTop2 (Glacier Bed Topography model version 2), in which ice thickness is inferred from surface slope by parameterizing basal shear...

  18. A Multistage Fluidized Bed for the Deep Removal of Sour Gases : Proof of Concept and Tray Efficiencies

    NARCIS (Netherlands)

    Driessen, Rick T.; Bos, Martin J.; Brilman, Derk W. F.

    2018-01-01

    Currently there are significant amounts of natural gas that cannot be produced and treated to meet pipeline specifications, because that would not be economically viable. This work investigates a bench scale multistage fluidized bed (MSFB) with shallow beds for sour gas removal from natural gas

  19. Markers of bone resorption and calcium metabolism are related to dietary intake patterns in male and female bed rest subjects

    Science.gov (United States)

    Smith, Scott M.; Zwart, S. R.; Hargens, A. r.

    2006-01-01

    Dietary potassium and protein intakes predict net endogenous acid production in humans. Intracellular buffers, including exchangeable bone mineral, play a crucial role in balancing chronic acid-base perturbations in the body; subsequently, chronic acid loads can potentially contribute to bone loss. Bone is lost during space flight, and a dietary countermeasure would be desirable for many reasons. We studied the ability of diet protein and potassium to predict levels of bone resorption markers in males and females. Identical twin pairs (8 M, 7 F) were assigned to 2 groups: bed rest (sedentary, SED) or bed rest with supine treadmill exercise in a lower body negative pressure chamber (EX). Diet was controlled for 3 d before and 30 d of bed rest (BR). Urinary Ca, N-telopeptide (NTX), and pyridinium crosslinks (PYD) were measured before and on days 5, 12, 19, and 26 of BR. Data were analyzed by Pearson correlation (Pdietary animal protein/potassium